bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elevated Serum Uric Acid Is a Facilitating Mechanism for Insulin Resistance Mediated Accumulation of Visceral Adipose Tissue
Authors: Fernandez-Chirino Luisa , Antonio-Villa Neftali Eduardo , Bello-Chavolla Omar Yaxmehen , Almeda-Valdes Paloma 
Published: May 2021

Abstract
Background: Serum uric acid (SUA) is related to cardiometabolic conditions such as insulin resistance (IR) and visceral adipose tissue (VAT) accumulation, which have a thoroughly explored bidirectional relationship. Here, we aimed to clarify the nature of the role uric acid plays inside this relationship, alongside the underlying causality mechanism.
Methods: We conducted a population-based cross-sectional study comprising 8,504 subjects from a joint cohort composed from both NHANES 2003–2004 and 2011–2012 cycles and ENSANUT Medio Camino 2016. We performed mixed effects linear regression models using HOMA2-IR, adipoIR, and METS-VF as indicators of both peripheral and adipose tissue IR and VAT accumulation, indicating the subject’s cohort of origin as a random effect. Furthermore, we performed multiple mediation analyses to assess a potential causal mechanism and ROC curves to establish cut-off points for identification of IR and visceral obesity using SUA. Finally, with an additional dataset comprised of 226 subjects with both euglycemic hyperinsulinemic clamp (EHC) and dual X-ray absorptiometry (DXA) measurements for IR and VAT accumulation, we performed a network of confirmatory mediation analyses including adiponectin measurements. Results: We found that SUA has a mediating role inside the bidirectional relationship between IR and visceral obesity, and it is part of an underlying causality mechanism which includes adiponectin. The proportion of the mechanism mediated by SUA is greater when stated that IR (in either peripheral or adipose tissue) leads to VAT accumulation (14.90%[13.20%-17.00%] and 15.54%[13.61%-18.00%]) instead of the opposite direction (4.88%[3.06%-7.00%] and 8.13%[5.91%-10.00%]). This result was strengthened by a mediation analysis network using the gold-standard measurements where we observed that the joint effect of SUA and adiponectin mediated 16.32% [8.84%-26.00%] for the effect of IR and VAT accumulation and 12.52% [3.23%-23.00%] in the opposite direction. Cut-off points for SUA to predict peripheral IR were 6.1 mg/dL and 4.8 mg/dL, for males and females respectively. For visceral obesity, cut-offs were 6.4 mg/dL and 4.8 mg/dL for males and females. SUA had a high negative predictive value for all assessments.
Conclusions: Elevated SUA acts as mediator inside the bidirectional relationship between IR and VAT accumulation. Its role appears to be larger when considering adipose tissue IR as the promoter for VAT accumulation.
HepatocyteGHR/STAT5b Signaling Protects Against Liver Injury in NAFLD/NASH Mice Models Independent of Steatosis
Authors: del Río-Moreno Mercedes , Vazquez-Borrego Mari C , Mahmood Mariyah , Sarmento-Cabral Andre , Guzman Grace , Subbaiah Papasani V , Cordoba-Chacon Jose , Kineman Rhonda Denise 
Published: May 2021

Abstract
Non-alcoholic fatty liver disease (NAFLD) represents a spectrum of pathologies ranging from simple steatosis to non-alcoholic steatohepatitis (NASH) that can lead to cirrhosis and hepatocellular carcinoma. Clinical and mouse studies indicate GH-signaling is reduced in NAFLD. We reported that chow-fed mice, with adult-onset, hepatocyte-specific GH receptor knockdown (aHepGHRkd) develop steatosis, and with age, a mild NASH-like phenotype. In the present study, we sought to determine if aHepGHRkd accelerates the development of steatosis and fibrosis in the context of diets shown in wild-type male mice, after 6 months of feeding, to produce mild NASH (60% fat [lard] + sucrose in the drinking water [HFS] or a severe NASH-like phenotype (40% fat, with partially hydrogenated corn-oil; 2% cholesterol; 20% fructose [HFCF]). Since aHepGHRkd is associated with a reduction in active STAT5b, aHepGHRkd mice were treated with either a hepatocyte-specific adenoviral-associated vector that expresses constitutively active STAT5b (AAV-TBGp-STAT5bCA = STAT5bCA) or a AAV-Null vector. After only 3 months of feeding either the HFS or HFCF diet, aHepGHRkd, but not GHR-intact controls, mice exhibited clear fibrosis, associated with higher levels of plasma alanine aminotransferase (ALT). STAT5bCA treatment of aHepGHRkd mice reduced fibrosis, as well as plasma ALT. Of note, hepatic TG content did not differ between the treatment groups, within diet. Preliminary studies used GC-MS to reveal aHepGHRkd, in the context of HFS diet, increased hepatic fatty acid ratios indicative of enhanced de novo lipogenesis, while STAT5bCA reversed this effect. These results suggest GHR/STAT5b may protect against liver injury not by controlling absolute fat accumulation, but by modifying the fatty acid composition of hepatic lipids. Finally, in order to determine if STAT5bCA could also reverse established diet-induced NASH, wild-type mice were fed the HFCF diet for 6 months and then treated with AAV-STAT5bCA or AAV-Null vectors, and followed for an additional 3 months. Preliminary findings show STAT5bCA modestly reduced liver weight with no changes in TG content. However, STAT5bCA prevented the rise in plasma ALT observed in Null-treated controls. Of note, some mice developed hepatic tumors, where the number and size of visible tumors was reduced by STAT5bCA. Importantly, in all models examined thus far, changes in the liver phenotype could not be clearly attributed to changes in systemic metabolism, supporting a direct action of GHR/STAT5b signaling on liver health. Taken together, these results suggest that enhancing hepatocyte STAT5b activity could prevent/treat diet-induced NASH. How STAT5b mediates these effects, and if there are other players involved, remains to be elucidated.
Prenatal Exposure to the Endocrine Disrupting Chemical DEHP Impacts Reproduction-Related Gene Expression in the Pituitary
Authors: Ge Xiyu , Weis Karen , Raetzman Lori 
Published: May 2021

Abstract
Phthalates are chemicals used in various common products including plastics and medical devices, leading to widespread contact. Phthalate exposure during embryonic development can cause changes in puberty timing, reduced fertility and genital abnormalities. Previous studies on prenatal exposure to Di-(2-ethylhexyl) phthalate (DEHP) in mice indicated that it disrupts pituitary-gonadal feedback and alters reproductive performance in the offspring, however, the mechanism behind this is unknown. We hypothesize that prenatal exposure to DEHP during a critical period of embryonic development (e15.5 to e18.5) will cause sex-specific disruptions in reproduction-related functions in the pituitary in offspring due to interference with androgen and aryl hydrocarbon receptor (AhR) signaling. In order to discover the direct effects of DEHP on the reproduction-related functions in the pituitary, we performed both in vivo dosing and in vitro pituitary culture experiments. First, we dosed pregnant CD-1 mice with corn oil, the antiandrogen flutamide or DEHP from gestational day 15.5 to 18.5, then collected the pituitaries of the offspring on postnatal day 0. We found that prenatal DEHP exposure caused a significant increase in Fshb specifically in males, and flutamide caused significant increases in both Lhb and Fshb in males. Besides, DEHP exposure significantly increased AhR pathway related gene Cyp1b1 in both males and females. In the in vitro experiment, we took whole pituitaries from e16.5 embryos and cultured them in media containing DEHP, MEHP and/or AhR antagonist for 72hrs. We found that the DEHP metabolite MEHP was actually the chemical that exerted the effects directly at the level of the pituitary. Similar to in vivo experiments, Cyp1a1 and Cyp1b1 mRNA level were increased in pituitaries treated with MEHP in both sexes and the induction could be reduced by co-treatment with AhR antagonist. The mRNA level of Lhb, Fshb and Gnrhr were significantly decreased in both sexes by MEHP and co-treatment with AhR antagonist did not restore mRNA levels. The induction of Cyp1a1/Cyp1b1 gene in both in vivo and in vitro experiments indicates the possible activation of AhR by DEHP/MEHP. The in vitro experiment with AhR antagonist further proved that the induction of Cyp1a1/Cyp1b1 was indeed due to AhR activation directly at the level of the pituitary. The difference between in vivo and in vitro experiments in terms of gonadotropin gene expression indicates multiple mechanisms should be involved in the regulation of gonadotropin gene expression in vivo including androgen-related pathways and possibly AhR-related pathways. In summary, our data suggest that phthalates can directly affect the function of the pituitary in terms of regulation of reproductive- related genes. This indicates that pituitary impacts of phthalates could contribute to reproductive dysfunction observed in exposed mice and humans.
Thyroid Gland and Male Reproductive Anomalies Among Fuel Handlers in Gampaha District, Sri Lanka
Authors: Kottahachchi Dulani Chathurika , Warnakularuriya Tania , De silva Deepthi , Madagoda Kushan , Wadasinghe Dilesha , Dayanath Bktpi , Siyambalapitiya Sajith , Devanarayana Niranga 
Published: May 2021

Abstract
Introduction:Fuel handlers at petrol stations are continuously exposed to organic solvents from fuel and vehicle emissions. Endocrine disrupting chemicals (EDC) are present in fuel, which are harmful to endocrine organs. Thyroiditis and hypogonadism are reported among fuel handlers. Thyroid gland and male reproductive function anomalies were investigated among fuel handlers in the Gampaha district of Sri Lanka. Method: 43 were recruited from 6 fuel stations in the Gampaha district for the study and 28 age matched male workers who were not exposed to fuel in an occupational setting were recruited as controls. Thyroid gland was examined clinically and TSH, free T4, FSH, LH and Testosterone were done on all the participants. TPO antibody and a thyroid scan was done on the fuel handlers. Results: Median (IQR) age was 38 years (27-46 years). The mean TSH value was 1.62 IU/mL (1.15-2.35) vs 1.33 IU/mL (0.83-1.79) respectively in study and control populations with significantly higher levels in the study population (p=0.023). The median (IQR) TSH value above the reference range was identified in 7% of fuel handlers and all controls were within the normal range, while 16.9% of fuel handlers had a derangement in the TPO levels. On examination, only one control had a small goiter but his T4 and TSH levels were normal. On ultrasound thyroid scans, benign nodules were seen in 2 fuel handlers. TPO levels did not correlate with the TSH levels among the fuel handlers (r=-0.078, p=0.652). Inability to sustain an erection was reported by 35.5% fuel handlers which was significantly higher than controls who reported 5.6% (p=0.019). Premature ejaculation was reported by 27.9% of fuel handlers which was significantly higher than controls (p=0.023). The testosterone levels were significantly higher among fuel handlers compared to controls (p=0.048). The FSH and LH levels positively correlated with each other as expected in each subgroup and the total population (p&lt;0.005). The TSH levels significantly negatively correlated with the testosterone levels among the fuel handlers. (r=- 0.338, p=.0.023). When the fuel handlers with premature ejaculation was considered the FSH, LH, Testosterone levels were not significantly different between the two groups, however the duration of employment was significantly longer among those reporting premature ejaculation. (p=0.024). Conclusion: There are thyroid and reproductive abnormalities among those exposed to fuel in an occupational setting. Disturbances to sexual functions may also be related to alteration of autonomic functions. Limiting exposure to fuel vapor will eliminate these detrimental effects and we propose self-service fuel pumps to be the best alternative to avoid occupational health hazards among fuel handlers.
Tildacerfont for the Treatment of Patients With Classic Congenital Adrenal Hyperplasia: Results From a 12-Week Phase 2 Clinical Trial in Adults With Classic CAH
Authors: Auchus Richard Joseph , Merke Deborah P , Madu Ivy-Joan , Nakhle Samer , Sarafoglou Kyriakie , Huang Michael , Moriarty David , Barnes Chris , Newfield Ron S 
Published: May 2021

Abstract
Background: Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is an autosomal recessive disorder characterized by insufficient cortisol production resulting in excess adrenocorticotropic hormone (ACTH) and adrenal androgen production. Standard-of-care therapy with glucocorticoids (GC) is suboptimal due to the difficulty of balancing control of the ACTH-driven androgen excess against the serious long-term side effects associated with chronic supraphysiologic GC exposure. Tildacerfont, a second-generation corticotropin-releasing factor type-1 (CRF1) receptor antagonist, lowers excess ACTH, and thus has the potential to reduce adrenal androgen production and to allow for GC dosing closer to physiologic doses. A prior study demonstrated that tildacerfont was effective in reducing ACTH, 17-hydroxyprogesterone (17-OHP) and androstenedione (A4) after 2 weeks of therapy. Here we report results from an open-label 12-week extension study. Methods: Subjects met either of the following criteria: 1) completion of prior study or 2) treatment naïve to tildacerfont with 17-OHP &gt;800 ng/dL while on a stable GC regimen (excluding dexamethasone). Subjects were treated with oral tildacerfont at 400 mg once daily for 12 weeks. Efficacy and safety parameters were assessed at baseline through Week 12. Results: Subject characteristics (n=8) are as follows: median (range) age was 44.5 years (26-67 years; 5 females), median (range) body mass index 30.8 kg/m2 (22-41 kg/m2). In month 3, in the participants with poor control of disease at baseline (elevations in all key biomarkers: ACTH, 17-OHP, and A4) (n=5), maximum mean percentage reductions for ACTH, 17-OHP and A4 were 84%, 82%, and 79%, respectively. In this subgroup, 60% of subjects achieved ACTH normalization and 40% achieved A4 normalization during treatment. Tildacerfont treatment maintained, and did not suppress, biomarkers in participants with good control of disease at baseline (A4 below upper limit of normal) (n=3). Overall, tildacerfont was well tolerated with no serious adverse events.
Conclusions: This is the first study of 12 weeks’ duration for a novel, non-steroidal mechanism-of-action agent for the treatment of 21-OHD. Results of this study show that tildacerfont was generally well-tolerated and effective in achieving meaningful reductions in ACTH and A4 in poorly controlled patients over 12 weeks. In addition, this is the first, non-steroidal therapeutic to show evidence of ACTH and A4 normalization over 12 weeks of therapy. Longer term future studies will evaluate whether treatment with tildacerfont can achieve further clinical benefits and allow reduction of GC doses while controlling relevant disease biomarkers.
Bile Acids Induce IQ Containing GTPase Activating Protein 1 to Alleviate Liver Injury
Authors: Sen Anushna , Erickson Hanna , Anakk Sayeepriyadarshini 
Published: May 2021

Abstract
Bile acids (BA) are cholesterol metabolites synthesized in the liver. In addition to their role as detergents, bile acids can function as signaling molecules via the activation of nuclear and G-protein coupled receptors, FXR and TGR5. BA signaling is associated with inflammation, cell proliferation, as well as apoptosis in the liver. Excessive accumulation of bile acids in the liver (cholestasis) is observed in many diseased states. We found that the scaffold protein IQGAP1 was induced in mouse models of cholestasis and in patients. In vitro BA treatment of liver cell-line, HepG2 also induced IQGAP1 in a dose-dependent manner. To investigate the role of this IQGAP1 induction, we fed wild-type male mice 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet for 3days, 1week, and 2weeks. Serum bile acid and hepatic IQGAP1 induction increased concomitantly with time. We next treated Iqgap1-/- male mice similarly with DDC and found a 3-fold increase in serum bile acid levels compared to treated wild-type mice. Liver injury markers ALT, AST, and bilirubin were also increased. Although Iqgap1-/- mice had similar gene expression of key BA regulators, Fxr and Shp as wild-type mice, the alteration in expression of BA transporters and reduced cell-cell junction protein levels may contribute to the elevated BAs levels. We quantified gene expression of pro-inflammatory and proliferative mediators using qRT-PCR and examined the liver histology with immuno-staining. We found Iqgap1-/- livers expressed increased pro-inflammatory mediators and proliferative genes like Il-6 and cyclin D1 along with MAPK signaling targets, Fos and Egr-1. To further examine how IQGAP1 functions as a mediator of bile acid signaling, we have generated IQGAP1 domain deleted constructs and are examining their protein-protein interactions with Mass Spec. Based on our results, IQGAP1 induction subsequent to accumulation of BAs is protective against injury in the liver.
Differential Activity and Utilization of Glucocorticoid Receptor Binding Sites Yields Transcriptional Heterogeneity
Authors: Hoffman Jackson Andrew , Trotter Kevin W , Day Christopher R , Ward James M , Rodriguez Joseph , Archer Trevor K 
Published: May 2021

Abstract
Synthetic glucocorticoids such as Dexamethasone (Dex) are widely prescribed drugs used to treat a variety of human diseases including auto-immune disorders, asthma, cancer, and COVID-19. The transcriptional response to glucocorticoids is elicited by the Glucocorticoid Receptor (GR), which enters the nucleus upon Dex treatment and interacts with thousands of enhancer elements throughout the genome. We recently demonstrated that the Dex response in human breast cancer cells is highly heterogeneous and that individual cells have unique transcriptional responses to Dex. To examine whether this heterogeneity arises from differential utilization of distinct GR-bound enhancers, we focused on the Dex response at the DNA Damage Inducible Transcript 4 (DDIT4) gene. Using a variety of genomic techniques, we identified four GR binding sites (GBSs) 18-30kb upstream of the DDIT4 TSS with differential patterns of chromatin accessibility, histone acetylation, SWI/SNF recruitment, and enhancer RNA (eRNA) transcription. To determine whether these GBSs had unique requirements for DDIT4 transcription, we used CRISPR-CAS9 to generate homozygous deletions of each site. Using ChIP-seq, 4C-seq, single molecule fluorescent in situ hybridization (smFISH), and RT-PCR, we demonstrated GR binding to these GBSs was independent and each GBS deletion had unique effects on DDIT4 and eRNA transcription, local histone acetylation, and chromatin looping. Deletion of any of the first three GBSs resulted in delayed and/or decreased induction of DDIT4 transcription whereas deletion of the fourth GBS resulted in significant upregulation of both DDIT4 and eRNA transcription. Thus, three of the GBSs acted as enhancers of DDIT4 expression while the fourth functioned as a suppressor. Strikingly, smFISH also revealed that these enhancers contributed to cellular heterogeneity, as deleting the GBSs altered the frequency and amplitude of DDIT4 transcription across cell populations. Taken together, these results demonstrate that individual GBSs uniquely contribute to cell-to-cell heterogeneity within the transcriptional response of DDIT4 to Dex. Furthermore, they underscore the possibility that targeted modification of individual GBSs could be utilized to tailor custom, patient-specific strategies for the treatment of human diseases.
Evaluation of Mayer-Rokitansky-Kuster-Hauser (MRKH) Patient Families by Whole Genome Sequencing
Authors: Dougherty Michael P , Chorich Lynn P , Layman Lawrence Clarke 
Published: May 2021

Abstract
Introduction: MRKH is a characterized by the congenital absence of the uterus and vagina in 46,XX individuals. A subset of these patients also has associated renal, skeletal, cardiac and/or auditory defects. Familial cases suggest a genetic component, but to date only pathogenic variants in WNT4 and HNF1B have been confirmed. We hypothesize that de novo heterozygous variants in candidate genes will be present in some patients with MRKH.
Methods: DNAs from 30 quads (an MRKH proband and three relatives) were subjected to whole genome sequencing (WGS), and heterozygous variants in coding regions with &lt; 0.02 frequency were filtered by two different methods. In the first approach, variants were filtered by 1) top consequence variant (splice site, stop-gain, frameshift, and missense, respectively); 2) impact score; 3) mapping quality; 4) cytobands; 5) intolerance; 6) de novo variants; and 7) plausibility based on familial genotype. The second approach considered only heterozygous variants found in the proband and absent in all other family members, which were then filtered by top consequence (splice donor and acceptor sites, stop-gain, frameshift).
Results: Five pedigrees were excluded for inadequate sequence in one or more individuals. 55,033 variants in coding regions with &lt; 2% frequency were identified in the 25 remaining quads for analysis. Using the first approach, 42 candidate gene variants in 32 genes were identified - 12 splice variants, 10 stop-gains, 15 frameshift variants and 5 missense variants. Of these, MUC22 contained 2 missense variants from different families. Additionally, DICER1 had multiple splice variants and is essential for mouse urogenital tract development. In the second approach, 39 candidate genes were identified—6 splice variants in 6 genes, 18 stop-gains in 17 genes, and 17 frameshift variants in 16 genes. Zinc finger genes (ZNF418, ZNF646, ZNF135, and ZNF772) comprised the most frequent class of the 39 genes. Two genes (MIR4436A and ZNF418) contained attractive variants in two different families.
Conclusion: WGS has been shown to improve detection of gene variants in coding regions, more so than whole exome sequencing (WES). We previously performed WES on 111 MRKH probands without family members and analyzed variants in candidate genes suggested by mouse and preliminary human studies. Interestingly, in this study, only three genes overlapped with previously suspected candidate genes. Here, we identified new candidates based upon potential deleteriousness. These candidate genes will be studied further in our families to determine their role in Mullerian development.