Blog Archive

Αλέξανδρος Γ. Σφακιανάκης

Monday, May 13, 2019

Political Behavior

Evaluating the News: (Mis)Perceptions of Objectivity and Credibility

Abstract

The introduction and popularity of politically biased news sources represents a significant historical shift in the media environment, with important unexplored consequences. Evidence points to partisan segmentation in the contemporary news market, but while assumptions abound, the mechanism driving consumers to sort along party lines is unclear. I develop a framework for news choice based on perceptions of objectivity and credibility and report a test of its central mechanism using a nationally representative survey experiment. I find support for a congenial media effect, where news content from an unfamiliar source is seen as more credible and less biased when it is consistent with existing beliefs, while balanced news content may be dismissed as less credible and biased. Previous studies have examined how perceptions of bias in identical news content can change when it is attributed to different sources. In today's media world however, access to more news sources generally and the ease with which content from those sources can be shared makes it increasingly likely people will be exposed to news content from either unknown or potentially fake news sources. This study contributes to the literature by identifying the unique effect of message content on perceptions of news bias and source credibility, while holding source constant. Paradoxically, my findings indicate that political selective exposure may arise out of individuals' genuine desire for unbiased news.



Is Sexism for White People? Gender Stereotypes, Race, and the 2016 Presidential Election

Abstract

On November 8, 2016 Donald Trump, a man with no office-holding experience, won the Electoral College, defeating the first woman to receive the presidential nomination from a major party. This paper offers the first observational test of how sexism affects presidential vote choice in the general election, adding to the rich literature on gender and candidate success for lower-level offices. We argue that the 2016 election implicated gender through Hillary Clinton's candidacy and Donald Trump's sexist rhetoric, and activated gender attitudes such that sexism is associated with vote choice. Using an Election Day exit poll survey of over 1300 voters conducted at 12 precincts in a mid-size city and a national survey of over 10,000 White and Black Americans, we find that a politically defined measure of sexism—the belief that men are better suited emotionally for politics than women—predicts support for Trump both in terms of vote choice and favorability. We find the effect is strongest and most consistent among White voters. However, a domestically defined measure of sexism—whether men should be in control of their wives—offers little explanatory power over the vote. In total, our results demonstrate the importance of gender in the 2016 election, beyond mere demographic differences in vote choice: beliefs about gender and fitness for office shape both White men and women's preferences.



Local Economic Shocks and National Election Outcomes: Evidence from Hungarian Administrative Data

Abstract

What are the consequences of unequal economic conditions on national election results? In this study, we use extraordinarily granular economic data measured without sampling error to assess how variation in local economic conditions across 3152 settlements affects incumbent support across the two most recent Hungarian elections. In addition, we use 95 monthly surveys capturing vote intention for nearly 100,000 respondents to assess possible individual level mechanisms. We find that the local economic milieu has a substantial effect on incumbent support, and that this effect was especially pronounced in the 2010 election that coincided with the peak of the Great Recession. Our micro-level analyses support these findings and suggest that the effect of local unemployment is unlikely to be explained by an aggregation of dissatisfaction among the unemployed.



The Personality of the Politically Ambitious

Abstract

Until recently, political ambition has largely been considered to be a product of the institutional and political environment. We argue that individual personality plays a significant role in nascent political ambition and progressive ambition. Using a nationally representative survey in the United States and a survey of public officials, we find a strong relationship between personality traits and nascent ambition. We find that individuals with higher levels of extraversion and openness are more likely to consider running for office, while agreeable and conscientious individuals are significantly less interested. We also find that personality traits do not relate to progressive ambition in the same way as they do to nascent ambition. In fact, they are weaker predictors of progressive ambition than they are of nascent ambition. We argue that democratic elections and public service attract certain types of individuals to seek office, which has implications for elite behavior and representation.



Traditional Versus Internet Media in a Restricted Information Environment: How Trust in the Medium Matters

Abstract

We use original survey data from Malaysia to explore differences in how traditional and digital media shape the attitudes and behavior of citizens. In closed, and even semi-authoritarian, states such as Malaysia, the Internet, including social media, is often the only place for opposition-centered media to thrive. As a result, consumption of Internet media is related to dissident attitudes. We argue that this relationship, though, is mitigated by trust in the medium. Our results suggest: (1) trust in traditional and Internet media determines the frequency with which citizens use each corresponding medium to gather political information, (2) higher trust in traditional media is positively associated with attitudes about democratic conditions in Malaysia; the opposite is true for trust in Internet media, (3) trust in the traditional media is negatively related, and trust in Internet media is positively related to the inclination to protest, (4) the positive relationship between digital media consumption and this attitude is stronger for those who trust Internet media, and diminished among those who trust traditional media.



Civic Duty and Voter Turnout

Abstract

We argue that two different sets of considerations shape the decision to vote or abstain in an election–ethical and non-ethical. First the citizen may vote out of a sense of duty. Failing that, she may vote because she has strong preferences about the outcome of the election. Abstention occurs when neither duty nor a sufficiently strong preference is present. The implication is that while duty and preference each have strong positive effects on turnout, they also have a negative interaction effect, since the impact of preference is much weaker among those with a sense of duty. We present a wide array of empirical evidence that systematically supports our claim that the turnout decision is importantly shaped by this causal heterogeneity. Thus a turnout model misses something fundamental if it does not take into account the effect of civic duty.



Issue Accountability in U.S. House Elections

Abstract

This paper analyzes the positions Members of Congress take on important aspects of public policy, voters' preferences on those issues, and individual-level voting behavior in congressional elections. Minimal evidence of issue accountability is found, and its form is different from that reported in previous research. The central implication is that representatives appear to have a good deal of discretion to take positions—at least with respect to voters—without paying an electoral penalty. The "electoral blind spot" (Bawn et al. Perspect Polit 10(3):571–597, 2012) in congressional elections may be substantial.



The Political Consequences of Policing: Evidence from New York City

Abstract

This paper explores the effect that municipal policing can exert on politics, and specifically investigates the effect that Stop, Question, and Frisk (SQF) policing has had on voter turnout and candidate choice in New York City. While extant studies of the American criminal justice system have found that mass incarceration and felon disenfranchisement negatively impact political participation and engagement, few have explicitly explored policing's relationship with politics and fewer still consider its mobilizing potential. Mobilizing data from over 2.7 million geo-coded police stops and data from a series of national and municipal elections this paper uncovers a pattern of voter demobilization, voter mobilization, and candidate choice that cannot be anticipated from extant studies in the literature. Specifically, it finds that while concentrated policing was associated with reductions in voter turnout in the 2006 and 2010 midterm elections, it was associated with higher rates of turnout in the 2008 presidential election and 2013 Democratic primary and general mayor. Further analysis demonstrates that stopping intensity was strongly associated with candidate choice in the 2013 Democratic mayoral primary, such that higher rates of policing were positively associated with support for the candidate (John Liu) who advocated for eliminating SQF and less support for the candidate (William Thompson) who supported SQF. Together, these findings highlight the impact that policing can exert on political behavior, characterize the impact that harmful policing policies can play in instigating policing participation and engagement, and foreground the importance of considering local criminal justice policy and political action.



What I Like About You: Legislator Personality and Legislator Approval

Abstract

Recent work in the study of legislative politics has uncovered associations between the Big Five personality traits and myriad phenomena in the United States Congress. This literature raises new questions about political representation in terms of the Big Five, specifically, whether voters are more likely to support legislators with similar personality traits to their own, who would presumably have similar process preferences, or legislators with valence personality traits, regardless of congruence, which are associated with better leadership. We first revisit the measurement validity of voter assessments of legislator personality in the 2014 and 2016 Cooperative Congressional Election Studies to demonstrate that such survey items are meaningful. Subsequently, we use these data to construct measures of personality congruence and valence and apply them to predict voters' job approval of legislators. Our results support the claim that voters evaluate legislators' job performance on the basis of perceived valence traits rather than legislators' congruence to voters' own personality dispositions.



Pigeonholing Partisans: Stereotypes of Party Supporters and Partisan Polarization

Abstract

What comes to mind when people think about rank-and-file party supporters? What stereotypes do people hold regarding ordinary partisans, and are these views politically consequential? We utilize open-ended survey items and structural topic modeling to document stereotypes about rank-and-file Democrats and Republicans. Many subjects report stereotypes consistent with the parties' actual composition, but individual differences in political knowledge, interest, and partisan affiliation predict their specific content. Respondents varied in their tendency to characterize partisans in terms of group memberships, issue preferences, or individual traits, lending support to both ideological and identity-based conceptions of partisanship. Most importantly, we show that partisan stereotype content is politically significant: individuals who think of partisans in a predominantly trait-basedmanner—that is, in a way consistent with partisanship as a social identity—display dramatically higher levels of both affective and ideological polarization.



VOICE




Adherence of Patients With Dysphonia to Voice Therapy: Systematic Review
Adherence expresses the patient's degree of commitment to the therapeutic process. It's necessary for professionals to know how to evaluate it in order to plan more effective conducts. This study aims to perform a systematic review of the adherence of patients with a dysphonia setting to voice therapy programs. This review was carried out on the PubMed, Lilacs, Scopus, and Cochrane Library databases, using a search strategy related to the subject of the study. The selection included studies that assessed the adherence of patients with dysphonia to voice therapy using an instrument created for the study or previously validated.

Laryngeal Diadochokinesis Across the Adult Lifespan
Diadochokinetic tasks provide valuable clinical information regarding neuromuscular control and coordination. Laryngeal diadochokinesis (LDDK) has the potential to provide insight into the neuromotor functioning of the larynx, but interpretation is limited because of sparse normative data. This study provides normative data for LDDK tasks across the adult lifespan in men and women.

Application of High-Frequency Transcutaneous Electrical Nerve Stimulation in Muscle Tension Dysphonia Patients With the Pain Complaint: The Immediate Effect
The aim of the present study was to investigate the immediate effect of the application of high-frequency Transcutaneous electrical nerve stimulation (TENS) in muscle tension dysphonia (MTD) patients with the pain complaint.

Evaluation of Voice Quality in Patients With Vocal Fold Polyps: The Size of a Polyp Matters or Does it?
This study aimed to investigate the correlation between morphological features of vocal fold polyps (VFPs) and subjective/objective voice parameters.

Classifying and Identifying Motor Learning Behaviors in Voice-Therapy Clinician-Client Interactions: A Proposed Motor Learning Classification Framework
We studied whether concepts in motor skill learning could be operationalized to identify clinical interactions and behaviors in a voice therapy setting. Our aim was to test the feasibility of measuring these behaviors in the prepractice phase so that we could eventually evaluate and apply principles of motor learning and skill acquisition to Speech-Language Pathology. Four general categories of behaviors that have been identified in the client-clinician prepractice phase were identified: motivation, modeling, verbal information, and feedback.

Vocal Health Education in Undergraduate Performing Arts Training Programs
Vocal health is taught in multiple formats and to varying degrees across undergraduate training programs. The aim of the study is to identify what methods of instruction lead to a better self-perception of vocal health in order to more adequately prepare graduates for the extreme demands of the performing arts industry.

The Influence of Linguistic Demand on Symptom Expression in Adductor Spasmodic Dysphonia
Adductor Spasmodic Dysphonia (ADSD), a form of focal dystonia, has been defined as a neurogenic, task-specific disorder characterized by abrupt spasms of intrinsic laryngeal muscles that result in phonatory breaks. Voice breaks are typically isolated to propositional speech, and reported to increase in severity as speaking demand or complexity increases. Research to date has focused on variations in phonologic contexts and their influence on voice breaks. The influences of variables at lexical and syntactic levels of analysis have been less well-researched and yet may provide insight into observed variability of symptom manifestation in this rare voice disorder.

Normative Value of SVHI-10. Systematic Review and Meta-Analysis
The study aimed to determine the normative value of SVHI-10.

Effect of Dysphonia and Cognitive-Perceptual Listener Strategies on Speech Intelligibility
There is a high prevalence of dysphonia among professional voice users and the impact of the disordered voice on the speaker is well documented. However, there is minimal research on the impact of the disordered voice on the listener. Considering that professional voice users include teachers and air-traffic controllers, among others, it is imperative to determine the impact of a disordered voice on the listener. To address this, the objectives of the current study included: (1) determine whether there are differences in speech intelligibility between individuals with healthy voices and those with dysphonia; (2) understand whether cognitive-perceptual strategies increase speech intelligibility for dysphonic speakers; and (3) determine the relationship between subjective voice quality ratings and speech intelligibility.

The Effectiveness of Vocal Hygiene Education for Decreasing At-Risk Vocal Behaviors in Vocal Performers
This study examined the knowledge gained and behavioral changes made by vocal performers after attending a vocal hygiene education program. A single-group, pretest-posttest research design was utilized to examine the improvement of voice care knowledge and decrease of phonotraumatic behaviors in vocal performers. Data analysis involved a comparison of pretest and posttest responses from an online questionnaire. A paired sample t test revealed a statistically significant improvement in the participants' knowledge regarding the larynx, voice production, and vocal hygiene.

Ecotoxicology

Spatial variation in aquatic invertebrate and riparian songbird mercury exposure across a river-reservoir system with a legacy of mercury contamination

Abstract

Mercury (Hg) loading and methylation in aquatic systems causes a variety of deleterious effects for fish and wildlife populations. Relatively little research has focused on Hg movement into riparian food webs and how this is modulated by habitat characteristics. This study characterized differences in Hg exposure in aquatic invertebrates and riparian songbirds across a large portion of the Willamette River system in western Oregon, starting at a Hg-contaminated Superfund site in the headwaters (Black Butte Hg Mine) and including a reservoir known to methylate Hg (Cottage Grove Reservoir), all downstream reaches (Coast Fork and Willamette River) and off-channel wetland complexes (Willamette Valley National Wildlife Refuge Complex). After accounting for year, date, and site differences in a mixed effects model, MeHg concentrations in aquatic invertebrates varied spatially among habitat categories and invertebrate orders. Similarly, THg in songbird blood varied by among habitat categories and bird species. The highest Hg concentrations occurred near the Hg mine, but Hg did not decline linearly with distance from the source of contamination. Birds were consistently elevated in Hg in habitats commonly associated with enhanced MeHg production, such as backwater or wetlands. We found a positive but weak correlation between aquatic invertebrate MeHg concentrations and songbird THg concentrations on a site-specific basis. Our findings suggest that Hg risk to riparian songbirds can extend beyond point-source contaminated areas, highlighting the importance of assessing exposure in surrounding habitats where methylmercury production may be elevated, such as reservoirs and wetlands.



Chronic toxicity and biochemical response of Apis cerana cerana (Hymenoptera: Apidae) exposed to acetamiprid and propiconazole alone or combined

Abstract

Acetamiprid and ergosterol-inhibiting fungicide (EBI) are frequently applied to many flowering plants, while honey bees are pollinating agents or pollinators of the flowers. Hence honey bees are often exposed to these pesticides. But until now, the effects of theses combinations at field-realistic doses on honey bee health have been poorly investigated. In this study, we explore the synergistic mortality and some physiological effects in surviving honey bees after chronic oral exposure to acetamiprid and/or propiconazole in the laboratory. The results indicated that chronic combined exposure to acetamiprid and propiconazole produced a significant synergistic effect on mortality both for newly emerged bees (50% mortality in 7.2 days) and forager bees (50% mortality in 4.8 days). Honey bee weight of newly emerged bees was decreased after feeding food with a field concentration of acetamiprid and propiconazole, alone or combined for 10 days. Combination of acetamiprid and propiconazole also modulated the activities of P450s, GST and CAT in newly emerged bees and forager bees than either alone, but neither pesticide affected the activity of AChE. These results show that chronic combined exposure to pesticides of relatively low toxicity may caused severely physiological disruptions that could be potentially damaging for the honey bees.



Autotoxicity of root exudates varies with species identity and soil phosphorus

Abstract

Root exudate autotoxicity (i.e. root exudates from a given plant have toxic effects on itself) has been recognized to be widespread. Here we examined how plant species identity and soil phosphorus (P) availability influenced this autotoxicity and the possible stoichiometric mechanisms. We conducted an experiment with three species (Luctuca sativaSesbania cannabina, and Solidago canadensis), which were subject to four treatments consisting of activated carbon (AC) and soil P. AC addition increased the whole-plant biomass of each species under high P conditions and this AC effect varied strongly with species identity. For Solidago, the relative increase in whole-plant biomass due to AC addition was larger in the low P than in the high P. Root exudate autotoxicity differed between roots and shoots. AC addition decreased root N:P ratios but failed to influence shoot N:P ratios in three species. These findings suggest that soil P enrichment might mediate root exudate autotoxicity and that this P-mediated autotoxicity might be related to root N and P stoichiometry. These patterns and their implications need to be addressed in the context of plant communities.



Impacts of sulfanilamide and oxytetracycline on methane oxidation and methanotrophic community in freshwater sediment

Abstract

Methanotrophs are of great significance for the abatement of methane emission from anoxic environments. Antibiotics are ubiquitous in the environment and can affect microbial activity and community density and composition. However, information about the effect of antibiotics on methanotrophs is still lacking. The current study explored the influences of sulfonamides and tetracyclines on methane oxidation potential (MOP) and methanotrophic density and community structure in freshwater sediment microcosms. The addition of both sulfanilamide (SA) and oxytetracycline (OTC) could increase MOP and particulate methane monooxygenasesubunit A (pmoA) gene density but decrease the number of pmoA transcripts. Both SA and OTC could also have impacts on sediment methanotrophic community structure. The antibiotic effects on MOP and methanotrophs were found to depend on the dosage and type of antibiotics. This work could provide some new insights towards the links between methane oxidation and antibiotics.



Heavy metals transported through a multi-trophic food chain influence the energy metabolism and immune responses of Cryptolaemus montrouzieri

Abstract

Contamination of environment with heavy metals is increasingly becoming an issue of major concern across the globe. Heavy metals are highly toxic to humans as well as other organisms of the ecosystem. The translocation of heavy metals from soil to predatory insects via multi-tophic food chains can influence the growth, reproduction, metabolism and innate immune systems of the predators. This study was performed to observe the changes in energy metabolism and immune responses of Cryptolaemus montrouzieri feeding on heavy metal (Cd, Pb, Ni and Zn) contaminated pink hibiscus mealybug (Dysmicoccus neobrevipes). The average concentrations of Cd, Pb, Ni and Zn in mealybugs used for feeding assays were 30.57, 32.64, 31.47 and 33.19 mg/kg, respectively. The results showed a significant increase in total protein, glycogen, cholesterol and triglycerides content of Cmontrouzieri feeding on heavy metals contaminated mealybugs compared with control groups. The activities of endogenous enzymes (acid phosphatase and alkaline phosphatase) as well as antioxidant enzymes (SOD, POD and CAT) were significantly higher in beetles feeding on heavy metals contaminated mealybugs. Our results provide basic insight into the influences of heavy metals (Cd, Pb and Ni) on energy metabolism and the innate immune system of the insect predator (Cmontrouzieri) in a multi-trophic food chain. Further research on genetic processes involved in the regulation of metabolism and innate immune system of Cmontrouzieri is still needed.



Chromate detoxification potential of Staphylococcus sp. isolates from an estuary

Abstract

Chromium (Cr) pollution is an emerging environmental problem. The present study was carried out to isolate Cr-resistant bacteria and characterize their Cr detoxification and resistance ability. Bacteria screened by exposure to chromate (Cr6+) were isolated from Mandovi estuary Goa, India. Two isolates expressed high resistance to Cr6+ (MIC ≥ 300 µg mL−1), Cr3+ (MIC ≥ 900 µg mL−1), other toxic heavy metals and displayed a pattern of resistance to cephalosporins and ß-lactams. Biochemical and 16 S rRNA gene sequence analysis indicated that both isolates tested belonged to the Staphylococcus genus and were closely related to S. saprophyticusand S. arlettae. Designated as strains NIOER176 and NIOER324, batch experiments demonstrated that both removed 100% of 20 and 50 µg mL−1 Cr6+ within 4 and 10 days, respectively. The rate of reduction in both peaked at 0.260 µg mL−1 h−1ATP-binding cassette (ABC) transporter gene involved in transport of a variety of substrates including efflux of toxicants was present in strain NIOER176. Through SDS-PAGE analysis, whole-cell proteins extracted from both strains indicated chromium-induced specific induction and up-regulation of 24 and 40 kDa proteins. Since bacterial ability to ameliorate Cr6+ is of practical significance, these findings demonstrate strong potential of some estuarine bacteria to detoxify Cr6+ even when its concentrations far exceed the concentrations reported from many hazardous effluents and chromium contaminated natural habitats. Such potential of salt tolerant bacteria would help in Cr6+ bioremediation efforts.



Transgenerational sublethal effects of abamectin and pyridaben on demographic traits of Phytonemus pallidus (Banks) (Acari: Tarsonemidae)

Abstract

In addition to determining the lethal effects, identifying sublethal effects of a pesticide is crucial to understanding the total impact a pesticide may have on a pest population. We determined the sublethal effects the two pesticides, abamectin and pyridaben, have on the cyclamen mite, Phytonemus pallidus (Banks) (Acari: Tarsonemidae)—a major pest of strawberry. Demographic traits of the P. pallidus progeny (F1 generation) produced by parents (F0 generation) treated with a low lethal concentration (LC15) of abamectin and pyridaben were assessed using the age-stage, two-sex life table theory. The total longevity of the F1 generation (males = 10.78 days; female = 14.35 days) was the shortest in the progeny of the abamectin treated parents, differing significantly from the progeny of mites treated with pyridaben (males = 11.50 days, females = 15.63 days), and the control population (males = 13.50 days, females = 17.81 days). The intrinsic rates of increase (r) and the finite rates of increase (λ) of the progeny of abamectin (r = 0.0854 day−1λ = 1.0891 day−1) and pyridaben (r = 0.0951 day−1λ = 1.0997 day−1) treated parents were significantly lower than in the control mites (r = 0.1455 day−1λ = 1.1567 day−1). The lowest fecundity (5.35 eggs/female), occurred in F1 female offspring of parents treated with LC15concentrations of abamectin, which was significantly lower than in the pyridaben (6.11 eggs/female) and control treatments (11.45 eggs/female). Transgenerational sublethal effects of abamectin and pyridaben in P. palliduscan be effectively used to for optimizing IPM programs against this pest on strawberries.



Persistent organic pollutants in lakes of Broknes peninsula at Larsemann Hills area, East Antarctica

Abstract

Anthropogenic activity in East Antarctica has increased since the last 2–3 decades because of various scientific expeditions. Additionally, global pollution due to various newly introduced pollutants like pesticides is on use since the past century and many factors contribute to contamination even in Antarctica. During thirty fourth Indian Scientific Expedition to Antarctica (ISEA) in austral summer of 2014–2015, fifteen lake water samples were collected from five different lakes at Broknes peninsula, Larsemann Hills, East Antarctica. Persistent Organic Pollutants (POPs) residue levels found in lake water samples varied from 10.33–70.00 pg/mL in five different lakes. Presence of p,p'-DDT was detected in all different lakes but high concentration found in P4 lake water. After study confirms that Broknes peninsula in the Larsemann Hills area, East Antarctica has a trace amount of POPs which is an alarming situation and needs to be investigated further to maintain the pristine environment in Antarctica. The presence of POPs may be attributed to orographic effects, migratory birds, biomagnification and anthropogenic sources. In the future, new emerging pollutants must be analyzed like microplastics, phthalate, Paraxanthene etc.



Direct and indirect effects of zinc oxide and titanium dioxide nanoparticles on the decomposition of leaf litter in streams

Abstract

As the production of metallic nanoparticles has grown, it is important to assess their impacts on structural and functional components of ecosystems. We investigated the effects of zinc and titanium nanoparticles on leaf decomposition in freshwater habitats. We hypothesized that nanoparticles would inhibit the growth and activity of microbial communities leading to decreased decomposition rates. We also hypothesized that under natural light, the nanoparticles would produce reactive oxygen species that could potentially accelerate decomposition. In the lab, whole Ficus vasta leaves were placed in containers holding one liter of stream water and exposed to either 0, 1, 10 or 100 mg/L of ZnO or TiO2 nanoparticles for six weeks (referred to as Exp. 1). We measured leaf mass loss, microbial metabolism, and bacterial density at 2, 4, and 6 weeks. In a second experiment (referred to as Exp. 2), we measured the effects of light and 10 and 100 mg/L ZnO or TiO2 nanoparticles on leaf mass loss, bacterial density and the bacterial and fungal community diversity over a 2 week period. In Experiment 1, mass loss was significantly reduced at 10 and 100 mg/L after 6 weeks and bacterial density decreased at 100 mg/L. In Experiment 2, there was no effect of ZnO nanoparticles on leaf mass loss, but TiO2nanoparticles significantly reduced mass loss in the dark but not in the light. One possible explanation is that release of reactive oxygen species by the TiO2 nanoparticles in the light may have increased the rate of leaf decomposition. Bacterial and fungal diversity was highest in the dark, but nanoparticles did not reduce overall diversity.



Development of marine water quality criteria for inorganic mercury in China based on the retrievable toxicity data and a comparison with relevant criteria or guidelines

Abstract

The development of marine water quality criteria (WQC) in China has been insufficient because data on the toxicity of pollutants for marine organisms based on the species sensitivity distribution (SSD) method are lacking. The Chinese aquatic environmental quality standards, including those for seawater, were derived from the developed countries. Therefore, establishing Chinese marine WQC is crucial for identifying the sensitivity of marine species in China and will improve their protection from threats. Mercury (Hg) is one of the primary pollutants commonly exceeding Chinese seawater quality standards. Several countries have developed their marine WQC for inorganic Hg in the past decades, but no study has been conducted in China. In this study, 45 acute toxicity and 14 chronic toxicity data of inorganic Hg on the marine species which inhabit in China were obtained mainly from the ECOTOX database, the CNKI, and the Google Scholar. The acute and chronic hazardous concentrations for 5% of the species (HC5) were calculated based on the best-fit distribution model Sweibull. The criteria for maximum and continuous concentrations of 1.30 and 0.66 μg/L, respectively, for inorganic Hg to protect marine organisms in China were derived by halving the HC5 values. The criteria were comparable to those of the United States, Australia, and the European Union countries, indicating the general applicability of WQCs developed based on the classical SSD method using different species groups. This study may provide valuable information for assessing marine ecological risk in China.



Archivum Immunologiae et Therapiae Experimentalis

Natural Killer and Natural Killer T Cells in Juvenile Systemic Lupus Erythematosus: Relation to Disease Activity and Progression

Abstract

The contribution of innate immune cells, including natural killer (NK) and natural killer T (NKT) cells, in systemic lupus erythematosus (SLE) is still unclear. Herein, we examined the frequency of peripheral NK cells, CD56dimand CD56bright NK cells, and NKT cells in patients with juvenile SLE and their potential relations to SLE-related clinical and laboratory parameters. The study included 35 SLE children and 20 apparently healthy controls. After baseline clinical and lab work, SLE Disease Activity Index (SLEDAI-2K) and Pediatric Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) Damage Index (Ped-SDI) scores were assessed. The frequency of peripheral NK cells, CD56dim and CD56bright NK cells, and NKT cells was examined using flow cytometry. SLE patients showed significantly lower frequency of NK cells and NKT cells and higher frequency of CD56bright NK cells compared to controls. Disease activity, urea, and creatinine correlated negatively with NK, but positively with CD56bright NK cells. NK and NKT cells exhibited inverse correlation with the renal biopsy activity index; however, CD56bright NK cells showed direct correlations with both activity and chronicity indices. Regarding Ped-SDI, renal, neuropsychiatry disorders, and growth failure correlated inversely with NK but directly with CD56bright NK cells. NKT cell inversely correlated with renal damage and delayed puberty. In conclusion, low frequency of NK and NKT and expansion of CD56bright NK cells are marked in juvenile SLE, particularly with activity. These changes have direct effect on renal impairment and growth failure, reflecting their potential influence on disease progression.



Heterogeneous Mixture of Amniotic Cells is Likely a Better Source of Stem Cells than Adipose Tissue

Abstract

Stem cells are increasingly being used in the course of burn treatment. As several different types of stem cells are available for the purposes, it is important to chose the most efficient and the most practicable stem cell type. The aim of this study was to compare the potential of heterogeneous amnion cell mixture with the presently used standard therapy, the adipose tissue-derived stem cells. The placenta was collected during a Cesarean section procedure. Adipose tissue tissue-derived cells were isolated using the Cytori's Celution® System. Cells were tested for fulfillment of the minimum criteria for stem cells. The efficiency of cell cultures was tested by an analysis of population doubling, cell proliferation, cell cycle and cell migration. Amniotic cells presented a higher ability for differentiation to chondrocytes and osteocytes than adipose-derived regenerative cells but a lower ability for differentiation toward adipocytes. Additionally, in vitro experiments have demonstrated a higher applicability of amniotic cells than adipose tissue-derived stem cells. Amniotic cells show several advantages: easy access to placenta, low costs and a lack of ethical dilemmas related to stem cell harvesting. The main disadvantage is, however, their availability, as isogenic treatment would only be possible for women around children-bearing age, unless personalized banks for amniotic cells would be established.



Significance and Role of Pattern Recognition Receptors in Malignancy

Abstract

Pattern recognition receptors (PRRs) are members of innate immunity, playing pivotal role in several immunological reactions. They are known to act as a bridge between innate and adaptive immunity. They are expressed on several normal cell types but have been shown with increasing frequency on/in tumor cells. Significance of this phenomenon is largely unknown, but it has been shown by several authors that they, predominantly Toll-like receptors (TLRs), act in the interest of tumor, by promotion of its growth and spreading. Preparation of artificial of TLRs ligands (agonists) paved the way to use them as a therapeutic agents for cancer, so far in a limited scale. Agonists may be combined with conventional anti-cancer modalities with apparently promising results. PRRs recognizing nucleic acids such as RIG-1 like receptors (sensing RNA) and STING (sensing DNA) constitute a novel promising approach for cancer immunotherapy.



Theaflavin-3, 3′-Digallate Attenuates Rheumatoid Inflammation in Mice Through the Nuclear Factor-κB and MAPK Pathways

Abstract

Rheumatoid arthritis (RA) is a common autoimmune disease which impacts a large number of patients worldwide, and new drugs are required for lower the disease burden. Theaflavin-3, 3′-digallate (TFDG) is polyphenol exhibiting inhibition on inflammatory factors. This study aimed to explore the attenuation of TFDG on RA. The collagen-induced arthritis (CIA) mouse model was established and administered with TFDG. The arthritis score and incidence was recorded to assess the amelioration of TFDG on arthritis. Histopathological change of the mouse joint tissues was evaluated by haemotoxylin and eosin staining. The expression of pro-inflammatory mediators including interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-6 was quantified by ELISA. The activation of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signaling pathways in the synovium were determined by Western blotting. In comparison with the control, administration of TFDG significantly reduced arthritis score and incidence in the CIA mouse model. TFDG significantly suppressed the expression of IL-1β, TNF-α, and IL-6, as well as the levels of MMP-1, MMP-2, and MMP-3 in the synovium. TFDG also showed remarkable inhibition on the activation of NF-κB and the phosphorylation of P38, JNK2, and ERK. This study puts up evidence that TFDG exerts protection on RA via inhibiting the activation of NF-κB- and MAPK-signaling pathways.



The Influence of Antidepressants on the Immune System

Abstract

Depression is one of the most frequently diagnosed condition in psychiatry. Despite the availability of many preparations, over 30% of treated patients do not achieve remission. Recently the emphasis is put on the contribution of the body's inflammatory response as one of the causes of depression. The interactions between nervous and immune systems are the main issue addressed by psychoneuroimmunology. In patients suffering from depression changes in the plasma concentrations of cytokines and in the number and level of activation of immune cells has been found. Attention is paid to the high levels of pro-inflammatory cytokines, the prevalence of Th1 responses to Th2, weakening of NK cell cytotoxicity and changes in lymphocyte proliferation and apoptosis. A number of studies focus on influence of antidepressants and non-standard methods of depression treatment, such as ketamine infusion, on patients' immunology. Many of them seem to regulate the immune responses. The study results encourage to look for new ways to treat depression with immunomodulatory drugs. In this article authors present the current knowledge about immune system changes accompanying depression as well as the study results showing the influence of drugs on the immune system, especially in the context of reducing the symptoms of depression.



PD-L1 Ameliorates Murine Acute Graft-Versus-Host Disease by Suppressing Effector But Not Regulatory T Cells Function

Abstract

There is increasing evidence that interaction between programmed death 1 (PD-1) and its ligands PD-1 (PD-L1) plays a critical role in the pathology of acute graft-versus-host disease (aGVHD). However, the role of PD-L1 in the development of aGVHD has been controversial in recent mouse studies. In this study, we carried out studies in a murine aGVHD model to clarify the role of PD-L1 in aGVHD pathogenesis. We found that systemic overexpression of PD-L1 by hydrodynamic gene transfer (HGT) method in vivo ameliorates aGVHD-induced lethality in mice. Systemic overexpression of PD-L1 inhibits the donor T cells activation, effector memory status, as well as Th1 and Th17 cells responses in vivo. In addition, PD-L1 Ig treatment significantly suppressed T cells' proliferation, promoted T cells' apoptosis, and reduced pro-inflammatory cytokines expression by effector T cells in vitro in the stimulation of anti-CD3/CD28 and allogeneic dendritic cells. However, we found that PD-L1 overexpression did not affect Treg cells' differentiation in vivo and in vitro, depletion of Treg cells in PD-L1 HGT recipients did not aggravate aGVHD mortality. Therefore, our results demonstrated that systemic treatment with PD-L1 protein ameliorates aGVHD by suppressing effector but not regulatory T cell function. Our findings suggest that systemic treatment with PD-L1 may be a potential strategy to prevent or ameliorate aGVHD.



Post-transplant Alternative Complement Pathway Activation Influences Kidney Allograft Function

Abstract

The complement system is one of the crucial pathophysiological mechanisms that directly influence the function of a transplanted kidney. Since the complement pathways' activation potential can be easily determined via their functional activity measurement, we focused on fluctuation in the cascade activity in the early post-transplant period. The aim of the study was to relate the kidney transplantation-induced complement system response to allograft outcome. Forty-two kidney recipients (aged: 53.5 [37–52], 17 females/25 males) and 24 healthy controls (aged: 40.5 [34–51], 13 females/11 males) were enrolled in the study. The functional activities of alternative, classical, and lectin pathways were determined before and in the first week after transplantation using Wielisa®-kit. We observed that the baseline functional activity of the alternative pathway (AP) was higher in chronic kidney disease patients awaiting transplantation compared to healthy controls and that its level depended on the type of dialysis. AP-functional activity was decreased following transplantation procedure and its post-transplant level was related to allograft function. The baseline and transplantation-induced functional activities of the classical and lectin pathways were not influenced by dialysis type and were not associated with transplant outcome. Moreover, our study showed that intraoperative graft surface cooling had a protective effect on AP activation. Our study confirms the influence of dialysis modality on persistent AP complement activation and supports the role of AP in an early phase after kidney transplantation and allograft outcome.



IgG from Non-atopic Individuals Induces In Vitro IFN-γ and IL-10 Production by Human Intra-thymic γδT Cells: A Comparison with Atopic IgG and IVIg

Abstract

Matured in the thymus, γδT cells can modulate the development of allergy in humans. The main γδT cell subsets have been described as interleukin (IL)-17A or interferon (IFN)-γ producers, but these cells can also produce other modulatory cytokines, such as IL-4 and IL-10. Here, we aimed to evaluate whether IgG can modulate the profile of cytokine production by γδT cells during their maturation in the thymus and after its migration to peripheral tissues. Thymic tissues were obtained from 12 infants, and peripheral blood mononuclear cells (PBMCs) were obtained from adults (both groups without an atopic background). IgG was purified from atopic and non-atopic volunteers. Thymocytes and PBMCs were cultured with purified atopic or non-atopic IgG, and intracellular cytokine production and phenotype were assessed. Mock and IVIg conditions were used as controls. IgG from non-atopic individuals induced IFN-γ and IL-10 production by thymic γδT cells, and no effect was observed on peripheral γδT cells. IL-17 production was inhibited by non-atopic IgG on thymic γδT cells and augmented by atopic IgG on peripheral γδT cells. Modulated thymic γδT cells did not produce IFN-γ and IL-10 simultaneously. We additionally evaluated the phenotype of intrathymic γδT cells and observed that IgG from all groups could induce CD25 expression and could not influence the CD28 expression of these cells. This report describes evidence revealing that IgG may influence the production of IFN-γ and IL-10 by intrathymic γδT cells depending on the donor atopic state. This observation is unprecedented and needs to be considered in further studies in the IgG immunotherapy field.



Conjugation of Meningococcal Lipooligosaccharides Through Their Non-Reducing Terminus Results in Improved Induction a Protective Immune Response

Abstract

The present studies prove that conjugation of meningococcal lipooligosaccharides through their non-reducing terminus conserves their inner epitopes resulting in conjugates potent to induce a protective immune response. Four different oligosaccharides were obtained by specific degradations of the same L7 lipooligosaccharide (L7-LOS), and each was linked to tetanus toxoid by direct reductive amination. Two were truncated oligosaccharides with incomplete inner epitopes and were obtained by mild acid hydrolysis of lipooligosaccharide. The terminal galactose of one oligosaccharide was additionally enzymatically oxidized. These oligosaccharides were conjugated through a newly exposed terminal Kdo in reducing end or through oxidized galactose localized at non-reducing end of the core, respectively. The third was a full-length oligosaccharide obtained by O-deacylation of the L7-LOS and subsequent enzymatic removal of phosphate substituents from its lipid A moiety. The fourth one was also a full-length O-deacylated lipooligosaccharide, but treated with galactose oxidase. This allowed direct conjugation to tetanus toxoid through terminal 2-N-acyl-2-deoxy-d-glucopyranose or through oxidized galactose, respectively. Comparison of the immune performance of four conjugates in mice revealed, that while each was able to induce significant level of L7-LOS-specific IgG antibody, the conjugates made with the full-length saccharides were able to induce antibodies with increased bactericidal activity against homologous meningococci. Only full-length oligosaccharides were good inhibitors of the binding of L7-LOS to the bactericidal antiserum. Moreover, induction of the significant level of the L7-LOS-specific antibody by full-length lipooligosaccharide conjugated from non-reducing end, provided also the direct evidence that internal core epitopes are fully responsible for the immunorecognition and immunoreactivity.



The Effect of Fucoidan, a Potential New, Natural, Anti-Neoplastic Agent on Uterine Sarcomas and Carcinosarcoma Cell Lines: ENITEC Collaborative Study

Abstract

The aim of the study was to assess the activity of fucoidan on the uterine sarcomas (MES-SA and ESS-1) and carcinosarcoma cell lines (SK-UT-1 and SK-UT-1B) and its toxicity on the human skin fibroblasts (HSF). Two uterine sarcomas and two carcinosarcoma cell lines were examined, as a control HSF were used. Cell viability was assessed with MTT test, apoptosis with caspase-3 activity and cell cycle by assessment of DNA synthesis. Fucoidan significantly decreases cell viability in SK-UT-1, SK-UT-1B, and ESS-1 cell lines, such effect was not observed in MES-SA. Fucoidan was not substantially affecting proliferation among normal cells. The tested agent induced apoptosis in all cell cultures used in the experiment. Fucoidan affects cell cycle of all tested cell lines except MES-SA by increasing percentage of cells in G0/sub-G1/G1 phase. Fucoidan do not only affect proliferation but induces apoptosis in selected uterine sarcoma and carcinosarcoma cell lines, so it has potential to be used as cytotoxic agent. Fucoidan seems to be promising anti-cancer agent for endometrial stromal sarcoma and carcinosarcoma.



Molecular Histology

Distribution of sperm antigen 6 (SPAG6) and 16 (SPAG16) in mouse ciliated and non-ciliated tissues

Abstract

The cilia and flagella of eukaryotic cells serve many functions, exhibiting remarkable conservation of both structure and molecular composition in widely divergent eukaryotic organisms. SPAG6 and SPAG16 are the homologous in the mice to Chlamydomonas reinhardtii PF16 and PF20. Both proteins are associated with the axonemal central apparatus and are essential for ciliary and flagellar motility in mammals. Recent data derived from high-throughput studies revealed expression of these genes in tissues that do not contain motile cilia. However, the distribution of SPAG6 and SPAG16 in ciliated and non-ciliated tissues is not completely understood. In this work, we performed a quantitative analysis of the expression of Spag6 and Spag16 genes in parallel with the immune-localization of the proteins in several tissues of adult mice. Expression of mRNA was higher in the testis and tissues bearing motile cilia than in the other analyzed tissues. Both proteins were present in ciliated and non-ciliated tissues. In the testis, SPAG6 was detected in spermatogonia, spermatocytes, and in the sperm flagella whereas SPAG16 was found in spermatocytes and in the sperm flagella. In addition, both proteins were detected in the cytoplasm of cells from the brain, spinal cord, and ovary. A small isoform of SPAG16 was localized in the nucleus of germ cells and some neurons. In a parallel set of experiments, we overexpressed EGFP-SPAG6 in cultured cells and observed that the protein co-localized with a subset of acetylated cytoplasmic microtubules. A role of these proteins stabilizing the cytoplasmic microtubules of eukaryotic cells is discussed.



Effects of Nel-like molecule-1 and bone morphogenetic protein 2 combination on rat pulp repair

Abstract

Nel-like molecule-1 (NELL-1) is a novel highly specific growth factor that can induce osteoblast differentiation and bone formation as well as odontoblast differentiation. Recent studies have suggested that NELL-1 can synergistically increase bone formation and regeneration with bone morphogenetic protein 2 (BMP2) and inhibit adverse effects induced by BMP2. This study aimed to evaluate the combined effects of NELL-1 and BMP2 on rat pulp repair. The experiment used healthy non-carious maxillary first molars from 60 Wistar rats. Exposed pulps were capped with NELL-1 plus BMP2, NELL-1 alone, and BMP2 alone, and each was absorbed onto a sterile collagen sponge. In the control samples, the collagen sponge alone and Dycal were used as capping agents. After l, 2 and 4 weeks, the rats were sacrificed. The formation of reparative dentin, as well the situation of pulp repair, was detected by hematoxylin-eosin (HE) staining; moreover, the expression of dentin specific protein-dentin sialophosphoprotein (DSPP) and the pro-inflammatory cytokines interleukin-6 (IL6) and interleukin-8 (IL8) was detected by immunohistochemical staining. Quantitative real-time PCR experiment was used to investigate the mRNA levels of IL6 and IL8. The results showed that pulp capping with NELL-1 plus BMP2 in rats had superior ability in inducing reparative dentin formation with dentin tubules and in reducing the inflammatory cell response compared with the other groups. These findings suggested that combined use of NELL-1 and BMP2 could positively regulate pulp repair.



Quantitative changes in perineuronal nets in development and posttraumatic condition

Abstract

Perineuronal net (PNN) is a highly structured portion of the CNS extracellular matrix (ECM) regulating synaptic plasticity and a range of pathologic conditions including posttraumatic regeneration and epilepsy. Here we studied Wisteria floribunda agglutinin-stained histological sections to quantify the PNN size and enrichment of chondroitin sulfates in mouse brain and spinal cord. Somatosensory cortex sections were examined during the period of PNN establishment at postnatal days 14, 21 and 28. The single cell PNN size and the chondroitin sulfate intensity were quantified for all cortex layers and specifically for the cortical layer IV which has the highest density of PNN-positive neurons. We demonstrate that the chondroitin sulfate proteoglycan staining intensity is increased between P14 and P28 while the PNN size remains unchanged. We then addressed posttraumatic changes of the PNN expression in laminae 6 and 7 of cervical spinal cord following hemisection injury. We demonstrate increase of the chondroitin sulfate content at 1.6–1.8 mm rostrally from the injury site and increase of the density of PNN-bearing cells at 0.4–1.2 mm caudally from the injury site. We further demonstrate decrease of the single cell PNN area at 0.2 mm caudally from the injury site suggesting that the PNN ECM takes part in the posttraumatic tissue rearrangement in the spinal cord. Our results demonstrate new insights on the PNN structure dynamics in the developing and posttraumatic CNS.



Changes in mechanoreceptors in rabbits' anterior cruciate ligaments with age

Abstract

At present, a few studies have been done on the changes in the distribution, morphology and quantity of mechanoreceptors in anterior cruciate ligament (ACL) with age. In this study, we observed the changes in mechanoreceptors of healthy rabbits' ACL with age. We found that rabbits' ACLs contained 5 kinds of mechanoreceptors including Ruffini corpuscles, Pacinian corpuscles, Golgitendon bodies, free nerve endings and atypical mechanoreceptors. In each ACL, free nerve endings were the most followed by Ruffini corpuscles, Pacinian corpuscles, Golgitendon bodies and atypical mechanoreceptors in the younger than one-old rabbits. Most of the mechanoreceptors were distributed in the synovium near the attachment points of ACL with the femur and tibia. The total quantity of mechanoreceptors were the most in the 3- and 6-month groups, but did not show a significant difference between the two group (P > 0.05). However, there were significant differences in the total quantity of mechanoreceptors between other groups (all P < 0.05). RT-PCR indicated that NEFM and S100B levels increased with age, and reached a peak in the 1-year group with significant differences as compared to other groups. NEFM and S100B levels were the second in 6-month and 2-year groups and the lowest in the 1-week group. We can conclude that in rabbits' ACLs, free nerve endings are the most common, followed by Ruffini corpuscles, Pacinian corpuscles and Golgitendon bodies. The total quantity of mechanoreceptors reaches a peak in 3 months, while NEFM and S100B reach a peak in 1 year.



Role of mTOR complex in IGF-1 induced neural differentiation of DPSCs

Abstract

Recent studies have demonstrated that IGF-1 modulates the pluripotent differentiation of dental pulp stem cells (DPSCs). Although mTOR pathway activation has been showed as responsible for IGF-1 induced pluripotent differentiation, the mechanism that the IGF-1–mTOR pathway induces the neural differentiation of DPSCs is still unclear. In our research, we have demonstrated that 0–10 ng/mL IGF-1 had no obvious effect on the proliferation of DPSCs, but IGF-1 nonetheless enhances the neural differentiation of DPSCs in a dose-dependent manner. Simultaneously, we found that phosphorylated mTOR was up-regulated, which indicated the involvement of mTOR in the process. Rapamycin, an inhibitor of mTOR activity, can reverse the effect of DPSCs stimulated by IGF-1. Next, we studied the role of mTORC1 and mTORC2, two known mTOR complexes, in the neural differentiation of DPSCs. We found that inhibition of mTORC1 can severely restricts the neural differentiation of DPSCs. However, inhibition of mTORC2 has the opposite effect. This latter effect disappears when both rictor and mTOR are inhibited, showing that the mTORC2 effect is mTORC1 dependent. This study has expanded the role of mTOR in DPSCs neural differentiation regulated by IGF-1.



Expression of CPNE7 during mouse dentinogenesis

Abstract

Interactions between the ectodermal and mesenchymal tissues are the basis of the central mechanism regulating tooth development. Based on this epithelial-mesenchymal interaction (EMI), we demonstrated that copine-7 (CPNE7) is secreted by preameloblasts and regulates the differentiation of mesenchymal cells of dental or non-dental origin into odontoblasts. However, the precise expression patterns of CPNE7 in the stages of tooth development have not yet been elucidated. The aim of the present study was to establish the spatiotemporal expression pattern of CPNE7 during mouse tooth development. To examine the spatiotemporal expression patterns of CPNE7 during mouse tooth development, we investigate the distribution of CPNE7 in the embryonic and postnatal developing mouse tooth. Immunohistochemistry, in situ hybridization, real-time PCR, and western blot analysis are performed to investigate the CPNE7 expression pattern during tooth development of the mandibular mouse first molar. During the initiation stage (bud stage), CPNE7 protein expression is observed in the dental epithelium but not yet in the dental mesenchyme. At E18 (bell stage), expression of CPNE7 protein and mRNA is primarily observed in ectomesenchymal cells of dental papilla. At P7 (crown formation stage), CPNE7 is localized in differentiating odontoblasts but weak expression is detected in mature ameloblasts. These findings suggest that CPNE7 secreted by dental epithelium induces the differentiation of ectomesenchymal cells into preodontoblast in concert with EMI. CPNE7 is clearly expressed in differentiating odontoblasts and the odontoblast process during dentinogenesis, but is no longer expressed in fully differentiated odontoblasts. Furthermore, CPNE7 is expressed in the Hertwig's epithelial root sheath (HERS) and in the facing preodontoblasts during root dentin formation. Taken together, these results illustrate the dynamic expression of CPNE7 during tooth development and suggest its important function in entire stages of tooth development.



Type XI collagen–perlecan–HS interactions stabilise the pericellular matrix of annulus fibrosus cells and chondrocytes providing matrix stabilisation and homeostasis

Abstract

The aim of this study was to ascertain whether, like many cell types in cartilaginous tissues if type XI collagen was a pericellular component of annulus fibrosus (AF) cells and chondrocytes. Fine fibrillar networks were visualised which were perlecan, HS (MAb 10E4) and type XI collagen positive. Heparitinase-III pre-digestion abolished the type XI collagen and 10E4 localisation in these fibrillar assemblies demonstrating a putative HS mediated interaction which localised the type XI collagen. Type XI collagen was confirmed to be present in the Heparitinase III treated AF monolayer media samples by immunoblotting. Heparitinase-III generated ΔHS stub epitopes throughout these fibrillar networks strongly visualised by MAb 3-G-10. Monolayers of murine hip articular chondrocytes from C57BL/6 and Hspg2 exon 3 null mice also displayed pericellular perlecan localisations, however type XI collagen was only evident in the Wild type mice. Perlecan was also immunolocalised in control and murine knee articular cartilage from the two mouse genotypes subjected to a medial meniscal destabilisation procedure which induces OA. This resulted in a severe depletion of perlecan levels particularly in the perlecan exon 3 null mice and was consistent with OA representing a disease of the pericellular matrix. A model was prepared to explain these observations between the NPP type XI collagen domain and HS chains of perlecan domain-I in the pericellular matrix of AF cells which likely contributed to cellular communication, tissue stabilization and the regulation of extracellular matrix homeostasis.



Expression patterns of genes critical for SHH, BMP, and FGF pathways during the lumen formation of human salivary glands

Abstract

Sjögren's syndrome or radiotherapy for head and neck cancer leads to the irreversible hypofunction of salivary gland (SG). The stem/progenitor cell-based regenerative strategy has been proven to be the most promising approach to repair the function of SG. The molecular mechanisms that regulate SG morphogenesis, especially during lumen formation, provide valuable hints for establishment of such regenerative strategies. It has been demonstrated that numerous growth factors particularly belonging to SHH, BMP, and FGF signaling pathway are involved in the regulation of lumen formation and have shown protective effects on the SG from irradiation in mouse models. However, it remains elusive whether the expression pattern and function of these signaling molecules are conserved in humans. In this study, we examined the expression patterns of the molecules critical for SHH, BMP, and FGF signaling cascades from the canalicular stage to the terminal bud stage, the key stages for lumen formation, in human SG and compared them with the expression data observed in mice. Our results manifested that genes involved in SHH signaling pathway showed identical expression patterns, while genes involved in BMP as well as FGF pathway exhibited similar but distinct expression patterns in humans to those in the mouse. We concluded that the expression patterns of genes involved in SHH, BMP, and FGF pathways in the development of human SG exhibit high similarity to that in the development of mouse SG during lumen formation, suggesting that the molecular mechanism regulating the morphogenesis of SG during lumen formation may be conserved in mice and humans. Our results will have an implication in the future establishment of stem-cell based approaches for the repair of SG function.



Hyperinsulinemia-induced KLF5 mediates endothelial angiogenic dysfunction in diabetic endothelial cells

Abstract

Reduced expression of endothelial nitric oxide synthase (eNOS) is a hallmark of endothelial dysfunction in diabetes, which predisposes diabetic patients to numerous cardiovascular complications including blunted angiogenesis. The Krüppel-like factor (KLF) five has been implicated as a central regulator of cardiovascular remodeling, but its role in endothelial cells (ECs) remains poorly understood. We show here that expression of endothelial KLF5 was significantly increased in the ECs from mouse diabetes mellitus type 2 (T2DM) model, when compared to non-diabetic or T1DM mouse. KLF5 up-regulation by insulin was dependent on activation of multiple pathways, including mammalian target of rapamycin, oxidative stress and Protein kinase C pathways. Hyperinsulinemia-induced KLF5 inhibited endothelial function and migration, and thereby compromised in vitro and in vivo angiogenesis. Mechanistically, KLF5 acted in concert with the MTA1 coregulator to negatively regulate NOS3 transcription, thereby leading to the diminished eNOS levels in ECs. Conversely, potentiation of cGMP content (the essential downstream effector of eNOS signaling) by pharmacological approaches successfully rescued the endothelial proliferation and in vitro tube formation, in the HUVECs overexpressing the exogenous KLF5. Collectively, the available data suggest that the augmentation of endothelial KLF5 expression by hyperinsulinemia may represent a novel mechanism for negatively regulating eNOS expression, and may thus help to explain for the T2DM-related endothelial dysfunction at the transcriptional level.



Oligoprotective effect of metformin through the AMPK-dependent on restoration of mitochondrial hemostasis in the cuprizone-induced multiple sclerosis model

Abstract

Oxidative stress with mitochondrial defects has a central role in the development and deterioration of Multiple sclerosis (MS). According to new findings of the effects of metformin on mitochondrial function, has attracted a lot of attention. Furthermore, it is suggested that metformin exerts its beneficial influence through AMP-activated protein kinase (AMPK) pathway. In the current study, we investigated the possible protective effects of metformin on oxidative stress and mitochondrial function by activating the AMPK pathway in the cuprizone-induced demyelination. Mice were fed with cuprizone for 6 weeks. Animals simultaneously received metformin. After sacrificing animals, myelinations, and gliosis, changes in transcription factor and biochemical analysis were assessed. Transmission electron microscopy and luxol fast blue staining revealed that the myelinated axons within corpus callosum of cuprizone-induced demyelination animals increased after administration of metformin. Metformin also upregulated the expression of mitochondrial biogenesis genes. Furthermore, the biochemical analysis demonstrated that metformin ameliorated the oxidative stress induced by cuprizone. Immunohistochemistry analysis showed that astrogliosis and microgliosis were decreased after metformin administration while it enhanced the number of oligodendrocytes. Our data implicated that metformin exerts its therapeutic effects on MS by AMPK signaling improved mitochondrial homeostasis and protected oligodendrocytes.



Cancer Cell

Mitochondrial ClpP-Mediated Proteolysis Induces Selective Cancer Cell Lethality

Publication date: Available online 2 May 2019

Source: Cancer Cell

Author(s): Jo Ishizawa, Sarah F. Zarabi, R. Eric Davis, Ondrej Halgas, Takenobu Nii, Yulia Jitkova, Ran Zhao, Jonathan St-Germain, Lauren E. Heese, Grace Egan, Vivian R. Ruvolo, Samir H. Barghout, Yuki Nishida, Rose Hurren, Wencai Ma, Marcela Gronda, Todd Link, Keith Wong, Mark Mabanglo, Kensuke Kojima

Summary

The mitochondrial caseinolytic protease P (ClpP) plays a central role in mitochondrial protein quality control by degrading misfolded proteins. Using genetic and chemical approaches, we showed that hyperactivation of the protease selectively kills cancer cells, independently of p53 status, by selective degradation of its respiratory chain protein substrates and disrupts mitochondrial structure and function, while it does not affect non-malignant cells. We identified imipridones as potent activators of ClpP. Through biochemical studies and crystallography, we show that imipridones bind ClpP non-covalently and induce proteolysis by diverse structural changes. Imipridones are presently in clinical trials. Our findings suggest a general concept of inducing cancer cell lethality through activation of mitochondrial proteolysis.



Combination of Hypoglycemia and Metformin Impairs Tumor Metabolic Plasticity and Growth by Modulating the PP2A-GSK3β-MCL-1 Axis

Publication date: Available online 25 April 2019

Source: Cancer Cell

Author(s): Mohamed Elgendy, Marco Cirò, Amir Hosseini, Jakob Weiszmann, Luca Mazzarella, Elisa Ferrari, Riccardo Cazzoli, Giuseppe Curigliano, Andrea DeCensi, Bernardo Bonanni, Alfredo Budillon, Pier Giuseppe Pelicci, Veerle Janssens, Manfred Ogris, Manuela Baccarini, Luisa Lanfrancone, Wolfram Weckwerth, Marco Foiani, Saverio Minucci

Summary

Tumor cells may adapt to metabolic challenges by alternating between glycolysis and oxidative phosphorylation (OXPHOS). To target this metabolic plasticity, we combined intermittent fasting, a clinically feasible approach to reduce glucose availability, with the OXPHOS inhibitor metformin. In mice exposed to 24-h feeding/fasting cycles, metformin impaired tumor growth only when administered during fasting-induced hypoglycemia. Synergistic anti-neoplastic effects of the metformin/hypoglycemia combination were mediated by glycogen synthase kinase 3β (GSK3β) activation downstream of PP2A, leading to a decline in the pro-survival protein MCL-1, and cell death. Mechanistically, specific activation of the PP2A-GSK3β axis was the sum of metformin-induced inhibition of CIP2A, a PP2A suppressor, and of upregulation of the PP2A regulatory subunit B56δ by low glucose, leading to an active PP2A-B56δ complex with high affinity toward GSK3β.

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Evolutionary Trajectories of IDHWT Glioblastomas Reveal a Common Path of Early Tumorigenesis Instigated Years ahead of Initial Diagnosis

Publication date: 15 April 2019

Source: Cancer Cell, Volume 35, Issue 4

Author(s): Verena Körber, Jing Yang, Pankaj Barah, Yonghe Wu, Damian Stichel, Zuguang Gu, Michael Nai Chung Fletcher, David Jones, Bettina Hentschel, Katrin Lamszus, Jörg Christian Tonn, Gabriele Schackert, Michael Sabel, Jörg Felsberg, Angela Zacher, Kerstin Kaulich, Daniel Hübschmann, Christel Herold-Mende, Andreas von Deimling, Michael Weller

Summary

We studied how intratumoral genetic heterogeneity shapes tumor growth and therapy response for isocitrate dehydrogenase (IDH)-wild-type glioblastoma, a rapidly regrowing tumor. We inferred the evolutionary trajectories of matched pairs of primary and relapsed tumors based on deep whole-genome-sequencing data. This analysis suggests both a distant origin of de novo glioblastoma, up to 7 years before diagnosis, and a common path of early tumorigenesis, with one or more of chromosome 7 gain, 9p loss, or 10 loss, at tumor initiation. TERT promoter mutations often occurred later as a prerequisite for rapid growth. In contrast to this common early path, relapsed tumors acquired no stereotypical pattern of mutations and typically regrew from oligoclonal origins, suggesting sparse selective pressure by therapeutic measures.

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Small-Molecule Targeting of Oncogenic FTO Demethylase in Acute Myeloid Leukemia

Publication date: 15 April 2019

Source: Cancer Cell, Volume 35, Issue 4

Author(s): Yue Huang, Rui Su, Yue Sheng, Lei Dong, Ze Dong, Hongjiao Xu, Tengfeng Ni, Zijie Scott Zhang, Tao Zhang, Chenying Li, Li Han, Zhenyun Zhu, Fulin Lian, Jiangbo Wei, Qiangqiang Deng, Yungui Wang, Mark Wunderlich, Zhiwei Gao, Guoyu Pan, Dafang Zhong

Summary

FTO, an mRNA N6-methyladenosine (m6A) demethylase, was reported to promote leukemogenesis. Using structure-based rational design, we have developed two promising FTO inhibitors, namely FB23 and FB23-2, which directly bind to FTO and selectively inhibit FTO's m6A demethylase activity. Mimicking FTO depletion, FB23-2 dramatically suppresses proliferation and promotes the differentiation/apoptosis of human acute myeloid leukemia (AML) cell line cells and primary blast AML cells in vitro. Moreover, FB23-2 significantly inhibits the progression of human AML cell lines and primary cells in xeno-transplanted mice. Collectively, our data suggest that FTO is a druggable target and that targeting FTO by small-molecule inhibitors holds potential to treat AML.

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Synthetic Lethality of Wnt Pathway Activation and Asparaginase in Drug-Resistant Acute Leukemias

Publication date: 15 April 2019

Source: Cancer Cell, Volume 35, Issue 4

Author(s): Laura Hinze, Maren Pfirrmann, Salmaan Karim, James Degar, Connor McGuckin, Divya Vinjamur, Joshua Sacher, Kristen E. Stevenson, Donna S. Neuberg, Esteban Orellana, Martin Stanulla, Richard I. Gregory, Daniel E. Bauer, Florence F. Wagner, Kimberly Stegmaier, Alejandro Gutierrez

Summary

Resistance to asparaginase, an antileukemic enzyme that depletes asparagine, is a common clinical problem. Using a genome-wide CRISPR/Cas9 screen, we found a synthetic lethal interaction between Wnt pathway activation and asparaginase in acute leukemias resistant to this enzyme. Wnt pathway activation induced asparaginase sensitivity in distinct treatment-resistant subtypes of acute leukemia, but not in normal hematopoietic progenitors. Sensitization to asparaginase was mediated by Wnt-dependent stabilization of proteins (Wnt/STOP), which inhibits glycogen synthase kinase 3 (GSK3)-dependent protein ubiquitination and proteasomal degradation, a catabolic source of asparagine. Inhibiting the alpha isoform of GSK3 phenocopied this effect, and pharmacologic GSK3α inhibition profoundly sensitized drug-resistant leukemias to asparaginase. Our findings provide a molecular rationale for activation of Wnt/STOP signaling to improve the therapeutic index of asparaginase.

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γ-Catenin-Dependent Signals Maintain BCR-ABL1+ B Cell Acute Lymphoblastic Leukemia

Publication date: 15 April 2019

Source: Cancer Cell, Volume 35, Issue 4

Author(s): Noemie Luong-Gardiol, Imran Siddiqui, Irene Pizzitola, Beena Jeevan-Raj, Mélanie Charmoy, Yun Huang, Anja Irmisch, Sara Curtet, Georgi S. Angelov, Maxime Danilo, Mélanie Juilland, Beat Bornhauser, Margot Thome, Oliver Hantschel, Yves Chalandon, Gianni Cazzaniga, Jean-Pierre Bourquin, Joerg Huelsken, Werner Held

Summary

The BCR-ABL1 fusion protein is the cause of chronic myeloid leukemia (CML) and of a significant fraction of adult-onset B cell acute lymphoblastic leukemia (B-ALL) cases. Using mouse models and patient-derived samples, we identified an essential role for γ-catenin in the initiation and maintenance of BCR-ABL1+ B-ALL but not CML. The selectivity was explained by a partial γ-catenin dependence of MYC expression together with the susceptibility of B-ALL, but not CML, to reduced MYC levels. MYC and γ-catenin enabled B-ALL maintenance by augmenting BIRC5 and enforced BIRC5 expression overcame γ-catenin loss. Since γ-catenin was dispensable for normal hematopoiesis, these lineage- and disease-specific features of canonical Wnt signaling identified a potential therapeutic target for the treatment of BCR-ABL1+ B-ALL.

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Defining UHRF1 Domains that Support Maintenance of Human Colon Cancer DNA Methylation and Oncogenic Properties

Publication date: 15 April 2019

Source: Cancer Cell, Volume 35, Issue 4

Author(s): Xiangqian Kong, Jie Chen, Wenbing Xie, Stephen M. Brown, Yi Cai, Kaichun Wu, Daiming Fan, Yongzhan Nie, Srinivasan Yegnasubramanian, Rochelle L. Tiedemann, Yong Tao, Ray-Whay Chiu Yen, Michael J. Topper, Cynthia A. Zahnow, Hariharan Easwaran, Scott B. Rothbart, Limin Xia, Stephen B. Baylin

Summary

UHRF1 facilitates the establishment and maintenance of DNA methylation patterns in mammalian cells. The establishment domains are defined, including E3 ligase function, but the maintenance domains are poorly characterized. Here, we demonstrate that UHRF1 histone- and hemimethylated DNA binding functions, but not E3 ligase activity, maintain cancer-specific DNA methylation in human colorectal cancer (CRC) cells. Disrupting either chromatin reader activity reverses DNA hypermethylation, reactivates epigenetically silenced tumor suppressor genes (TSGs), and reduces CRC oncogenic properties. Moreover, an inverse correlation between high UHRF1 and low TSG expression tracks with CRC progression and reduced patient survival. Defining critical UHRF1 domain functions and its relationship with CRC prognosis suggests directions for, and value of, targeting this protein to develop therapeutic DNA demethylating agents.

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Intraclonal Plasticity in Mammary Tumors Revealed through Large-Scale Single-Cell Resolution 3D Imaging

Publication date: 15 April 2019

Source: Cancer Cell, Volume 35, Issue 4

Author(s): Anne C. Rios, Bianca D. Capaldo, François Vaillant, Bhupinder Pal, Ravian van Ineveld, Caleb A. Dawson, Yunshun Chen, Emma Nolan, Nai Yang Fu, 3DTCLSM Group, Felicity C. Jackling, Sapna Devi, David Clouston, Lachlan Whitehead, Gordon K. Smyth, Scott N. Mueller, Geoffrey J. Lindeman, Jane E. Visvader

Summary

Breast tumors are inherently heterogeneous, but the evolving cellular organization through neoplastic progression is poorly understood. Here we report a rapid, large-scale single-cell resolution 3D imaging protocol based on a one-step clearing agent that allows visualization of normal tissue architecture and entire tumors at cellular resolution. Imaging of multicolor lineage-tracing models of breast cancer targeted to either basal or luminal progenitor cells revealed profound clonal restriction during progression. Expression profiling of clones arising in Pten/Trp53-deficient tumors identified distinct molecular signatures. Strikingly, most clones harbored cells that had undergone an epithelial-to-mesenchymal transition, indicating widespread, inherent plasticity. Hence, an integrative pipeline that combines lineage tracing, 3D imaging, and clonal RNA sequencing technologies offers a comprehensive path for studying mechanisms underlying heterogeneity in whole tumors.

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CHD1 Loss Alters AR Binding at Lineage-Specific Enhancers and Modulates Distinct Transcriptional Programs to Drive Prostate Tumorigenesis

Publication date: 15 April 2019

Source: Cancer Cell, Volume 35, Issue 4

Author(s): Michael A. Augello, Deli Liu, Lesa D. Deonarine, Brian D. Robinson, Dennis Huang, Suzan Stelloo, Mirjam Blattner, Ashley S. Doane, Elissa W.P. Wong, Yu Chen, Mark A. Rubin, Himisha Beltran, Olivier Elemento, Andries M. Bergman, Wilbert Zwart, Andrea Sboner, Noah Dephoure, Christopher E. Barbieri

Summary

Deletion of the gene encoding the chromatin remodeler CHD1 is among the most common alterations in prostate cancer (PCa); however, the tumor-suppressive functions of CHD1 and reasons for its tissue-specific loss remain undefined. We demonstrated that CHD1 occupied prostate-specific enhancers enriched for the androgen receptor (AR) and lineage-specific cofactors. Upon CHD1 loss, the AR cistrome was redistributed in patterns consistent with the oncogenic AR cistrome in PCa samples and drove tumor formation in the murine prostate. Notably, this cistrome shift was associated with a unique AR transcriptional signature enriched for pro-oncogenic pathways unique to this tumor subclass. Collectively, these data credential CHD1 as a tumor suppressor in the prostate that constrains AR binding/function to limit tumor progression.

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Human Tumor-Associated Macrophage and Monocyte Transcriptional Landscapes Reveal Cancer-Specific Reprogramming, Biomarkers, and Therapeutic Targets

Publication date: 15 April 2019

Source: Cancer Cell, Volume 35, Issue 4

Author(s): Luca Cassetta, Stamatina Fragkogianni, Andrew H. Sims, Agnieszka Swierczak, Lesley M. Forrester, Hui Zhang, Daniel Y.H. Soong, Tiziana Cotechini, Pavana Anur, Elaine Y. Lin, Antonella Fidanza, Martha Lopez-Yrigoyen, Michael R. Millar, Alexandra Urman, Zhichao Ai, Paul T. Spellman, E. Shelley Hwang, J. Michael Dixon, Lisa Wiechmann, Lisa M. Coussens

Summary

The roles of tumor-associated macrophages (TAMs) and circulating monocytes in human cancer are poorly understood. Here, we show that monocyte subpopulation distribution and transcriptomes are significantly altered by the presence of endometrial and breast cancer. Furthermore, TAMs from endometrial and breast cancers are transcriptionally distinct from monocytes and their respective tissue-resident macrophages. We identified a breast TAM signature that is highly enriched in aggressive breast cancer subtypes and associated with shorter disease-specific survival. We also identified an auto-regulatory loop between TAMs and cancer cells driven by tumor necrosis factor alpha involving SIGLEC1 and CCL8, which is self-reinforcing through the production of CSF1. Together these data provide direct evidence that monocyte and macrophage transcriptional landscapes are perturbed by cancer, reflecting patient outcomes.

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