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ENDO 2021

Thyroid Immune Related Adverse Events May Be a Biomarker for Survival in Cancer Patients

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technical paper

We found 17 rare PCOS-specific functional protein-altering variants (PAVs) or mutations in the gene, AMH, that decrease the biologic activity of the encoded protein, anti-Müllerian hormone (AMH), in the heterozygous state. Approximately 3% of European ancestry PCOS cases in our cohort of ~700 were affected. Our preliminary studies found evidence for a metabolic phenotype in both PCOS as well as their male first-degree relatives who were heterozygous carriers of these AMH PAVs. We performed this study to test the hypothesis that AMH mutations are associated with metabolic abnormalities in the general population. The Mount Sinai BioMe Biobank is an electronic health record (EHR)-linked biobank, containing anonymized whole exome sequences from 30,813 participants of diverse ancestries. We interrogated the sequence data to identify individuals with PCOS-related AMH PAVs. IRB-approval was obtained to review the linked EHR. Outcomes were the presence of obesity (BMI ≥ 30 kg/m2), type 2 diabetes (hemoglobin A1C ≥ 6.5%), prediabetes (hemoglobin A1C 5.7% - 6.4%), elevated cholesterol (total cholesterol ≥ 200 mg/dL), hypertriglyceridemia (TG ≥ 150 mg/dL), and hypertension (≥2 blood pressure values ≥140/90, or administration of antihypertensive medications). Control subjects were obtained from the National Health and Nutrition Examination Survey using propensity score matching (for sex, age, and BMI) with a 1:4 case:control ratio. A total of 292 individuals with AMH PAVs were identified, resulting in a combined 0.95% prevalence of AMH PAVs in an unselected population (1.07% in Europeans, 0.28% in African Americans, 0.54% in Hispanics, and 0.07% in Asians). After adjusting for age, BMI, and race/ethnicity, there was a statistically significant increased prevalence of hypertriglyceridemia in both women (OR 7.29, 95% CI 3.77-14.00) and men (OR 10.15, 95% CI 4.68-22.00) with AMH ?PAVs compared to sex-, age- and BMI-matched controls. There was also a statistically significant increased prevalence of elevated cholesterol in men with AMH PAVs compared to controls (OR 2.48, 95% CI 1.15-5.34). There were no significant differences between individuals with AMH PAVs and matched controls with respect to the other outcomes. These findings suggest that decreased bioactivity of AMH is causally related to dyslipidemia in the general population. TG levels are elevated in both sexes, whereas increases in cholesterol are only seen in men. The mechanisms by which decreases in AMH bioactivity alter circulating lipid levels are of considerable interest since AMH has no known metabolic actions. It is possible that the putative metabolic effects of AMH are mediated by increases in circulating testosterone (T) levels that in turn alter lipid metabolism. Since T levels are not commonly available in EHR, future studies will be needed to investigate this hypothesis as well as to explore metabolic actions of AMH.?? 

Anti-Mullerian Hormone Protein-Altering Variants Are Associated with Hypertriglyceridemia in the General Population

The Impact of Glucose Tolerance States on Bone Mineral Density

Fixing Diabetes by Blocking Kidney-Specific GLUT2

Bile acids (BAs) have gained traction not just as emulsifiers of fat, but also as hormones. Nuclear receptor Farnesoid X receptor (FXR) is the master regulator of BAs and can also control glucose and lipid metabolism. We examined if FXR contributed towards heme biosynthesis and induction of a ductular reaction. Male and female whole body Fxr knockout (FxrKO) mice, as well as liver- and intestine-specific knockouts (LFxrKO and IFxrKO, respectively) were treated with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC, a ferrochelatase inhibitor) for two weeks. At the end of the two weeks, mice were fasted for four hours and euthanized. All groups of mice had lost a similar percentage of body weight when fed the DDC diet. However, female FxrKO mice had significantly increased liver to body weight ratio, while male FxrKO mice had significantly decreased liver to body weight ratio when fed the DDC diet compared with their wild type counterparts. Serum liver injury markers were analyzed and liver histology and changes in genes involved in the heme biosynthesis pathway were examined. Both male and female whole body FxrKO livers had decreased ductular reaction with minimal bile plugs (porphyrin accumulation) compared with their wild type counterparts. LFxrKO mice mimicked diminished ductular reaction, while IFxrKO mice exhibited severe ductular reaction similar to that of wild type mice, indicating that the ductular reaction is dependent on hepatic FXR. ChIP-Seq for FXR revealed binding peaks in the heme biosynthesis genes, Alas1, Alad, Uros, and Fech, suggesting that FXR may act as a transcription factor for these genes. Further investigation revealed that Pbgd gene expression was increased, while Fech gene expression was decreased in female FxrKO mice compared to wild type mice. In male mice, Pbgd, Uros, Urod, and Cpox gene expression was increased in the absence of Fxr. In conclusion, Fxr is necessary to mount a ductular reaction and plays a key role in heme biosynthesis in the liver.?? 

Investigating the Role of Farnesoid X Receptor in Heme Biosynthesis and Ductular Reaction

Hepatocyte GHR/STAT5b Signaling Protects Against Liver Injury in NAFLD/NASH Mice Models Independent of Steatosis

Inhibition of Angiopoietin-like (ANGPTL3) Reduces Adipose Tissue Insulin Resistance in Patients with Familial Partial Lipodystrophy

ROR𝛾+ T Cells as Key Players in Thyroid Autoimmunity from Immune Checkpoint Immunotherapy (ICI)

Iodoacetic acid (IAA) – a water disinfection byproduct (DBP) formed from the reaction between an oxidizing disinfectant, i.e. chlorine, and iodide – is an understudied, yet potentially dangerous environmental toxicant. DBPs have been epidemiologically associated with reproductive dysfunction. In vitro studies have indicated that IAA is one of the most cyto- and genotoxic DBPs. Further, murine ovarian research has shown that IAA exposure significantly inhibits antral follicle growth and reduces estradiol levels. Despite this evidence, little is known about the other components of the reproductive axis: the hypothalamus and pituitary. To address this, we tested the hypothesis that IAA exposure would lead to disrupted expression of key hypothalamic and pituitary genes related to reproductive function. We exposed adult female CD1 mice to 0.5, 10, 100, or 500 mg/L IAA in their drinking water from postnatal day 40 (P40) to their first day in diestrus after P75. From this experiment, we collected whole pituitaries and hypothalamic punches containing the arcuate nucleus (ARC), anteroventral periventricular zone (AVPV), and medial preoptic nucleus (mPOA), and processed them for mRNA analysis. We also exposed pituitary explant cultures to IAA to observe direct effects on gene expression. In vivo, we found that mRNA levels of kisspeptin (Kiss1) are significantly increased in the ARC, the region that controls pulsatile GnRH release, at 0.5 and 10 mg/L IAA concentrations. Kiss1 is unchanged in the AVPV, the neuron population responsible for generating the LH surge. We also measured ARC expression of neurokinin B (Tac2) and dynorphin (Pdyn), neuropeptides secreted by kisspeptin co-expressing neurons to autosynaptically stimulate Kiss1 release. We saw no difference in either. GnRH (Gnrh1) expression was also unchanged. Both in vivo at 10 mg/L IAA and in culture, we found IAA exposure significantly reduced Fshb mRNA. Preliminary immunohistochemistry (IHC) data suggests it also leads to an apparent reduction in FSH-positive cells in vitro (N=2). Lhb and the α-subunit (Cga) were unaltered in vivo, though were significantly reduced with in vitro exposure. In neither context was mRNA expression of the GnRH receptor (Gnrhr) changed. Noting apparent direct effects of IAA on the pituitary, we assessed expression of the cell-cycle inhibitor p21 (Cdkn1a), which has been shown to increase with toxicant exposure. We found Cdkn1a increased in vivo at 500 mg/L IAA, trending at 100 mg/L (p=.070), and in vitro. IHC data in vitro suggests a marked increase in P21-positivity following IAA exposure. These data, together with prior ovarian findings, implicate IAA as a potential reproductive axis disruptor at each major level – through ARC Kiss1 expression, Fshb expression in vivo and in vitro, FSH expression in vitro, and Lhb and Cga in vitro. Further, Cdkn1a/P21 induction indicates IAA toxicity at the level of the pituitary.?? 

Exposure to Iodoacetic Acid, a Water Disinfection Byproduct, Leads to Abnormal Expression of Key Reproductive Axis Genes in the Hypothalamus and Pituitary

Low 17β-estradiol (E2) levels suppress luteinizing hormone (LH) release, while high E2 stimulates an LH surge in the positive-feedback required for ovulation. Kisspeptin (Kp) neurons in the anteroventral periventricular (AVPV) and arcuate (ARC) nuclei of hypothalamus have been implicated in E2 positive- and negative-feedback effects, respectively. However, how E2 differentially regulates these two neuronal populations remains unknown. We investigated whether neurons in the AVPV and ARC are differently responsive to changes in E2 levels and the regulatory role of estrogen receptors (ERs). Ovariectomized (OV) rats received oil or E2 at doses of 4 (OVE-4), 40 (OVE-40), or 80 (OVE-80) µg/kg. Rats on diestrus (DI) and proestrus (PRO) were used as physiological controls. OV rats were also treated with 0.02, 0.2 or 2.0 mg/kg of propyl pyrazole triol (PPT), or 6 mg/kg of diarylpropionitrile (DPN). Serial blood samples were collected for hormonal measurements. Brains were processed for immunohistochemistry and qPCR analyses in the AVPV and ARC. The E2 doses gradually increased plasma E2, with PRO levels being attained in OVE-80 rats. OVE-80 rats displayed a PRO-like LH surge, while LH levels were constantly suppressed in OVE-4 rats. Progesterone receptor (PR) was used as an index of E2 responsiveness. PR expression was increased in the AVPV of PRO and OVE-80 rats, associated with c-Fos expression and occurrence of LH surge. In the ARC, both low and high E2 induced PR expression and reduced the number of Kp-immunoreactive (ir) neurons, consistent with the negative feedback effects on LH. E2 at 4 or 80 µg/kg equally induced PR expression in 90% of ARC Kp-ir neurons. Despite the higher sensitivity to E2 in the ARC, the percentage of neurons expressing ERα was lower in the ARC compared with AVPV. However, Esr1 expression was 2-fold higher in the ARC than in AVPV for low E2 levels, whereas both Esr1 and Esr2 were more expressed in the AVPV under high E2 status. Notably, Esr1/Esr2 ratio was twice as high in the ARC as in the AVPV regardless of E2 levels, suggesting a stronger ERβ inhibition over ERα in the AVPV. Accordingly, ERα selective activation with PPT increased PR in the ARC at the doses of 0.2 and 2.0 mg/kg, reducing plasma LH, while only the highest dose was able to stimulate PR expression in the AVPV. ERβ activation with DPN, in turn, had no effect in OV rats but amplified the induction of AVPV PR and the size of the LH surge in OVE-80 rats. Thus, we provide evidence that ARC and AVPV neurons are responsive to low and high E2 levels, respectively. ARC is 10 times more sensitive to ERα activation than AVPV, whereas ERβ positively modulates AVPV responsiveness to high E2. These differential responses to E2 seem to be related to differences in the relative Esr1 and Esr2 expression in the ARC and AVPV. Our findings suggest that hypothalamic differences in the relative expression of ERs play a key role in the bimodal regulation of LH release by E2.?? 

Differential Expression of Estrogen Receptors in the Hypothalamus Underlies the Bimodal Effects of Estradiol on Luteinizing Hormone Release

Background: Next generation sequencing has led to the categorization of thyroid cancer (TC) based on the molecular and transcriptomic profile into the BRAF-like and RAS-like tumors. The BRAF-RAS score (BRS) has been developed to quantify the extent to which the gene expression profile resembles either the BRAFV600E- or RAS-mutant profiles and is utilized as a continuous measure from -1 to +1, respectively. Oncogene-driven signaling pathways have an impact on the intracellular metabolism– glycolysis and oxidative phosphorylation (OXPHOS). There are limited data on the genotype-metabolic phenotype correlation in TC cells. Therefore, the goal of this study was to perform a comprehensive analysis of the association between the BRS and TC cell metabolism.Methods: We analyzed the mRNA expression of key enzymes involved in glycolysis (lactate dehydrogenase LDHA) and OXPHOS (ATP synthase) in 496 BRAF-like and RAS-like human TC tissue samples based on The Cancer Genome Atlas. We performed an in vitro study using 8 TC cell lines– 4 BRAF-like with BRS between -1 and 0, and 4 RAS-like with BRS between 0 and +1. OXPHOS was determined by measuring oxygen consumption rate (OCR) of each cell line using Seahorse XF Cell Mito Stress Test Kit, while Seahorse XF Glycolysis Stress Test Kit was used to measure the extracellular acidification rate (ECAR) due to anaerobic glycolysis The association between the OCR, ECAR and BRS was tested using the Pearson correlation coefficient (r). Student T-test was used to compare the continuous variables between the groups with a p-value of ≤ 0.05 as statistically significant. Results: RAS-like tumors were associated with higher mRNA expression of the OXPHOS marker ATP synthase than BRAF-like lesions, as evidenced by a moderate positive correlation (r = 0.5) between ATP synthase expression and BRS. BRAF-like tumors were characterized by a relatively higher mRNA expression of a glycolytic enzyme LDHA, as documented by a moderate negative correlation (r = -0.6) between LDHA expression and BRS. Consistently, functional in vitro studies revealed that RAS-like cell lines had a higher OXPHOS compared with BRAF-like cell lines (maximum OCR: 2538.4±1601.3 vs 548.5±276.5, p=0.049, respectively). The glycolysis rate was comparable between RAS-like and BRAF-like cell lines (maximum ECAR: 1290.4±520.5 vs 2399.9±1413.1, p=0.19, respectively). There was a strong positive correlation between the BRS and OCR (r=0.78) and a low to negligible negative correlation between BRS and ECAR (r=-0.26) in examined TC cell lines. Conclusions: BRAF-like and RAS-like tumors are characterized by distinct metabolic phenotypes with RAS-like TC more likely to utilize OXPHOS to meet metabolic demands. Therapeutic strategies targeting oncogene-driven signaling pathways and cancer metabolism based on distinct metabolic phenotypes may provide an individualized approach to TC therapy.?? 

Thyroid Immune Related Adverse Events May Be a Biomarker for Survival in Cancer Patients

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