👤 M G Sridhar

17β-Hydroxysteroid dehydrogenase 3 (17β-HSD3) deficiency is a rare 46XY disorder of sex development (DSD) of androgen biosynthesis. We aimed to describe the complexities in diagnosis, gender assignment, and the timing of irreversible surgical interventions in 17β-HSD3 deficiency. We described three genetically confirmed cases of 46XY DSD due to 17β-HSD3 deficiency. All of them had female-appearing external genitalia, and the third case had well-developed breasts with clitoromegaly. The biochemical evaluation showed hCG-stimulated T/A ratios of 0.4 and 0.35 in Cases 1 and 2, respectively, and an unstimulated T/A ratio of 0.25 in Case 3. Molecular analysis revealed three different 17β-HSD3 deficiency remains a challenging 46 XY DSD due to its clinical heterogeneity and diverse molecular spectrum. This report adds to current molecular knowledge by reporting two novel variants in the Show less

Glucagon-like peptide-1 receptor (GLP-1R) and neuropeptide Y receptors (NPYRs) are expressed in reproductive tissues contributing to the regulation of gonadal function. This exploratory study examines the potential impact of their modulation by assessing the effects of exendin-4 (Ex-4) and peptide YY (PYY) (3-36) on endocrine ovaries and adrenals in high-fat diet (HFD) mice. Ex-4 and PYY(3-36) reduced blood glucose and energy intake, with no effects on body weight. While HFD did not impact the estrous cycle, Ex-4 increased metestrus frequency and decreased diestrus frequency resulting in 0% mice experiencing repeated diestrus or becoming acyclic. Luteinizing hormone levels were significantly higher in the Ex-4 and PYY(3-36) groups compared to the normal diet and HFD controls. In the adrenals, reduced capsule and zona glomerulosa thickness caused by HFD was reversed after peptide treatments. Within the ovaries, HFD increased the number of atretic follicles, an effect that disappeared after Ex-4 and PYY(3-36) treatments. Ex-4 also increased the number of corpora lutea owing to the prolonged metestrus phase. Gene expression analysis within the adrenals revealed the upregulation of Insr and the downregulation of Prgtr in HFD mice, while Ex-4 downregulated the expression of Gipr. The ovarian gene expression of Gipr, Npy1r and Prgtr was downregulated by Ex-4 treatment, while PYY(3-36) significantly downregulated the Prgtr expression compared to HFD mice. These data indicate that manipulating GLP-1R and NPY2R leads to changes in the reproductive physiology of mice. In addition, the observed alterations in the morphology and gene expression in the adrenals and ovaries imply a direct impact of these peptides on female reproductive function. Show less

Obesity is increasingly prevalent worldwide, with genetic factors contributing to its development. The hypothalamic leptin-melanocortin pathway is central to the regulation of appetite and weight; leptin activates the proopiomelanocortin neurons, leading to the production of melanocortin peptides; these in turn act on melanocortin 4 receptors (MC4R) which suppress appetite and increase energy expenditure. MC4R mutations are responsible for syndromic and non-syndromic obesity. These mutations are classified based on their impact on the receptor's life cycle: Show less

Effects of sustained activation of glucagon-like peptide-1 (GLP-1) receptors (GLP-1R) as well as antagonism of receptors for glucose-dependent insulinotropic peptide (GIP) on intestinal morphology and related gut hormone populations have not been fully investigated. The present study assesses the impact of 21-days twice daily treatment with the GLP-1R agonist exendin-4 (Ex-4), or the GIP receptor (GIPR) antagonist mGIP(3-30), on these features in obese mice fed a high fat diet (HFD). HFD mice presented with reduced crypt depth when compared to normal diet (ND) controls, which was reversed by Ex-4 treatment. Both regimens lead to an enlargement of villi length in HFD mice. HFD mice had increased numbers of GIP and PYY positive ileal cells, with both treatment interventions reversing the effect on PYY positive cells, but only Ex-4 restoring GIP ileal cell populations to ND levels. Ex-4 and mGIP (3-30) marginally decreased GLP-1 villi immunoreactivity and countered the reduction of ileal GLP-1 content caused by HFD. As expected, HFD mice presented with elevated pancreatic islet area. Interestingly, mGIP(3-30), but not Ex-4, enhanced islet and beta-cell areas in HFD mice despite lack of effect of beta-cell turnover, whilst Ex-4 increased delta-cell area. Co-localisation of islet PYY or GLP-1 with glucagon was increased by Ex-4, whilst islet PYY co-immunoreactivity with somatostatin was enhanced by mGIP(3-30) treatment. These observations highlight potential new mechanisms linked to the metabolic benefits of GLP-1R agonism and GIPR antagonism in obesity. Show less

Obesity is a major cause of infertility in females with a direct correlation between energy intake and reproductive dysfunction. To explore underlying mechanisms, disturbances in reproductive health and incretin/reproductive hormone receptor expression were studied in female Wistar rats fed a high-fat-diet for 20-weeks. Metabolic parameters and ovarian/adrenal gene expression were monitored along with estrous cycling and fertility upon mating. High-fat-feeding significantly increased body weight, plasma insulin and HOMA-IR, indicative of obesity and insulin resistance. Estrous cycles were prolonged compared to normal chow-fed rats, with 50 % having an average cycle length ≥ 7days. Reproductive outcomes revealed high-fat-diet reduced litter size by 48 %, with 16 % rats unable to achieve pregnancy. Furthermore, 80 % of the high-fat group took > 35 days to become pregnant compared to 33 % fed a normal-diet. Also, 35 % of pups born to high-fat-fed rats were eaten by mothers or born dead which was not observed with control rats. These changes were associated with downregulation of Amh, Npy2R and GcgR gene expression in ovaries with upregulation of InsR and Glp-1R genes. In adrenals, Glp-1R, GipR, Npy2R, InsR, GcgR, GshR and Esr-1 genes were upregulated. Histological analysis of high-fat-diet ovaries and adrenals revealed changes in morphology with significantly increased number of cysts and reduced adrenal capsule thickness. Circulating levels of insulin, testosterone and progesterone was significantly higher in high-fat group with reduced FSH levels in plasma. These data demonstrate that high-fat feeding disrupts female reproductive function and suggest important interactions between gut and reproductive hormones in ovaries and adrenals which merit further investigation. Show less

Substantial evidence suggests crosstalk between reproductive and gut-axis but mechanisms linking metabolism and reproduction are still unclear. The present study evaluated the possible role of glucose-dependent-insulinotropic-polypeptide (GIP) and glucagon-like-peptide-1 (GLP-1) in reproductive function by examining receptor distribution and the effects of global GIPR and GLP-1R deletion on estrous cycling and reproductive outcomes in mice. GIPR and GLP-1R gene expression were readily detected by PCR in female reproductive tissues including pituitary, ovaries and uterine horn. Protein expression was confirmed with histological visualisation of incretin receptors using GIPR-Cre and GLP1R-Cre mice in which the incretin receptor expressing cells were fluorescently tagged. Functional studies revealed that female GIPR Show less

Over 35% of all adults in the world are currently obese and risk of obesity in racial or ethnic minority groups exist in the US, but the causes of these differences are not all known. As obesity is a leading cause of cardiovascular disease, an improved understanding of risk factors across racial and ethnic groups may improve outcomes. The objective of this study was to determine if susceptibility to obesity is associated with genetic variation in candidate single nucleotide polymorphisms (SNPs) in African Americans and Hispanic/Latinos. We examined data from 534 African Americans and 557 Hispanic/Latinos participants from the UIC Cohort of Patients, Family and Friends. Participants were genotyped for the top 26 obesity-associated SNPs within FTO, MC4R, TUB, APOA2, APOA5, ADIPOQ, ARL15, CDH13, KNG1, LEPR, leptin, and SCG3 genes. The mean (SD) age of participants was 49±13 years, 55% were female, and mean body mass index (BMI) was 31±7.5 kg/m2. After adjusting for age and sex, we found that rs8050136 in FTO (odds ratio [OR] 1.40, 95% confidence interval [CI] 1.1-1.8; P = 0.01) among African Americans and rs2272383 in TUB (OR 1.34, 95% CI 1.04-1.71; P = 0.02) among Hispanic/Latinos were associated with obesity. However, none of the SNPs in multivariable analysis of either AA or H/L cohorts were significant when adjusted for multiple correction. We show that candidate SNPs in the FTO and TUB genes are associated with obesity in African Americans and Hispanic/Latinos individuals respectively. While the underlying pathophysiological mechanisms by which common genetic variants cause obesity remain unclear, we have identified novel therapeutic targets across racial and ethnic groups. Show less

The web-based IceBear software is a versatile tool to monitor the results of crystallization experiments and is designed to facilitate supervisor and student communications. It also records and tracks all relevant information from crystallization setup to PDB deposition in protein crystallography projects. Fully automated data collection is now possible at several synchrotrons, which means that the number of samples tested at the synchrotron is currently increasing rapidly. Therefore, the protein crystallography research communities at the University of Oulu, Weizmann Institute of Science and Diamond Light Source have joined forces to automate the uploading of sample metadata to the synchrotron. In IceBear, each crystal selected for data collection is given a unique sample name and a crystal page is generated. Subsequently, the metadata required for data collection are uploaded directly to the ISPyB synchrotron database by a shipment module, and for each sample a link to the relevant ISPyB page is stored. IceBear allows notes to be made for each sample during cryocooling treatment and during data collection, as well as in later steps of the structure determination. Protocols are also available to aid the recycling of pins, pucks and dewars when the dewar returns from the synchrotron. The IceBear database is organized around projects, and project members can easily access the crystallization and diffraction metadata for each sample, as well as any additional information that has been provided via the notes. The crystal page for each sample connects the crystallization, diffraction and structural information by providing links to the IceBear drop-viewer page and to the ISPyB data-collection page, as well as to the structure deposited in the Protein Data Bank. Show less

Increased fructose consumption causes dyslipidemia and fatty liver in postmenopausal women, both independent risk factors for cardiovascular disease. This study explored the potential mechanisms by which amla (Emblica officinalis) reduced hypercholesterolemia and hypertriglyceridemia and prevented fatty liver in a fructose-fed, ovariectomized rat model of menopause. Sham-operated and ovariectomized rats were put on a chow or high fructose diet. They were further divided into groups with or without amla. After 18 weeks of treatment, livers were harvested and subjected to Western blot and histological analyses. In all groups, amla increased the protein expression of liver farnesoid X receptor (FXR) and liver X receptor (LXR), key proteins involved in lipid metabolism. Fructose-fed rats developed fatty liver and amla prevented this. Here amla produced an exceptional rise in LXR and insulin-induced gene-2 (Insig-2) which prevented the maturation of sterol regulatory element-binding protein-1 and steroyl CoA desaturase-1, responsible for triglyceride synthesis. Amla also increased the protein expression of ATP binding cassette transporter A1 (ABCA1), involved in high density lipoprotein (HDL) synthesis as well as low density lipoprotein receptor (LDLR) responsible for uptake of LDL cholesterol. Besides this, amla increased the protein expression of peroxisome proliferator activated receptor α (PPARα) involved in β oxidation of fatty acids. Amla increased the protein expression of liver FXR, LXRα, PPARα and their downstream proteins Insig-2, ABCA1 and LDLR. This property of amla to modulate some of the key proteins involved in lipid metabolism promises its usefulness as a preventive agent for dyslipidemia and hepatic steatosis. Show less