Blocking FSH inhibits hepatic cholesterol biosynthesis and reduces serum cholesterol

Revisiting the Characteristics of Testicular Germ Cell Lines GC-1(spg) and GC-2(spd)ts

Spermatogenesis is a multifaceted and meticulously orchestrated process involving meiosis, chromatin build up, transcriptional and translational hushing, and spermiogenesis. Male germ cell lines GC-1spg (GC-1) and GC-2(spd)ts (GC-2) provide a useful resource to comprehend the molecular events occurring during such a tightly regulated process. Using cDNA microarray, expression profiling of GC-1 and GC-2 cell lines was done to precisely understand their characteristics and uniqueness. Our observations indicate that whilst both the cell lines are indeed of testicular origin, GC-2 is not haploid as was originally thought. Data analysis of the 23,351 transcripts detected in GC-1 and 20,992 in GC-2 cell lines demonstrates an 80% transcript overlap between GC-1 and GC-2 cells and ~ 40% similarity of both with the primary spermatocyte transcriptome. 3152 and 793 transcripts exclusive to GC-1 and GC-2, respectively, were identified. The presence of transcripts for 36 genes was validated in these cell lines including those showing testis-specific expression, as well as genes not reported previously. Overall, this study provides the transcriptome database of GC-1 and GC-2 cells. Analysis of the data demonstrates the transcriptomic transitions between GC-1 and GC-2 thus providing a glimpse to the process of germ cell differentiation from type B spermatogonium into preleptotene spermatocyte.

Serum FSH Is Associated With BMD, Bone Marrow Adiposity, and Body Composition in the AGES-Reykjavik Study of Older Adults

CONTEXT

Follicle-stimulating hormone (FSH) concentrations increase during the perimenopausal transition and remain high after menopause. Loss of bone mineral density (BMD) and gain of bone marrow adiposity (BMA) and body fat mass also occur during this time. In mice, blocking the action of FSH increases bone mass and decreases fat mass.

OBJECTIVE

To investigate the associations between endogenous FSH levels and BMD, BMA, and body composition in older adults, independent of estradiol and testosterone levels.

DESIGN, SETTING, AND PARTICIPANTS

Older adults from the AGES-Reykjavik Study, an observational cohort study.

MAIN OUTCOME MEASURES

Areal BMD, total body fat, and lean mass were measured with dual-energy x-ray absorptiometry. Lumbar vertebral BMA was measured by 1H-magnetic resonance spectroscopy. Volumetric BMD and visceral and subcutaneous adipose tissue (VAT, SAT) areas were measured with quantitative computed tomography. The least squares means procedure was used to determine sex hormone-adjusted associations between quartiles of serum FSH and BMD, BMA, and body composition.

RESULTS

In women (N = 238, mean age 81 years), those in the highest FSH quartile, compared with the lowest quartile, had lower adjusted mean spine integral BMD (-8.6%), lower spine compressive strength index (-34.8%), higher BMA (+8.4%), lower weight (-8.4%), lower VAT (-17.6%), lower lean mass (-6.1%), and lower fat mass (-11.9%) (all P < 0.05). In men, FSH level was not associated with any outcome.

CONCLUSIONS

Older postmenopausal women with higher FSH levels have higher BMA, but lower BMD and lower fat and lean mass, independent of estradiol and testosterone levels. Longitudinal studies are needed to better understand the underlying mechanisms.

AhR/miR-23a-3p/PKCα axis contributes to memory deficits in ovariectomized and normal aging female mice

The mechanism of estrogen deficiency-induced cognitive impairment is still not fully elucidated. In this study, we assessed the effect of microRNA (miRNA) on the memory of long-term estrogen-deficient mice after ovariectomy (OVX) and normal aging. We observed that 5-month OVX and 22-month-old normal aging female mice showed significantly impaired spatial and object recognition memory, declined hippocampal long-term potentiation (LTP), and decreased hippocampal protein kinase C α (PKCα) protein. Quantitative real-time PCR analysis showed upregulated miRNA-23a-3p (miR-23a-3p) in the hippocampus of 5-month OVX and 22-month-old female mice. In vitro, overexpression of miR-23a-3p downregulated PKCα by binding the 3¢ UTRs of Prkca mRNAs, which was prevented by its antisense oligonucleotide AMO-23a. In vivo, adeno-associated virus-mediated overexpression of miR-23a-3p (AAV-pre-miR-23a-3p) suppressed hippocampal PKCα and impaired the memory of mice. Chromatin immunoprecipitation analysis showed that aryl hydrocarbon receptor (AhR) binds the promoter region of miR-23a-3p. The AhR-dependent downregulation of PKCα could be prevented by AMO-23a as well. Furthermore, knockdown of miR-23a-3p using AAV-AMO-23a rescued the cognitive and electrophysiological impairments of OVX and normal aging female mice. We conclude that long-term estrogen deficiency impairs cognition and hippocampal LTP by activating the AhR/miR-23a-3p/PKCα axis. The knockdown of miR-23a-3p may be a potentially valuable therapeutic strategy for estrogen deficiency-induced memory deficits.

High Circulating Follicle-Stimulating Hormone Level Is a Potential Risk Factor for Renal Dysfunction in Post-Menopausal Women

OBJECTIVE

Menopause contributes to renal dysfunction in women, which is generally attributed to estrogen withdrawal. In addition to decreased estrogen level, serum follicle-stimulating hormone (FSH) level increases after menopause. This study investigated the association between high circulating FSH level and renal function in post-menopausal women.

METHODS

This observational cross-sectional study included 624 pre-menopausal, 121 peri-menopausal, and 2540 post-menopausal women. The levels of female sex hormones were examined by chemiluminescence and indices of renal function were measured using a clinical chemistry analyzer. The post-menopausal women were grouped into quartiles according to serum FSH levels.

RESULTS

Renal function progressively declined from pre-menopause to peri-menopause to post-menopause, which was accompanied by increasing serum FSH level. In post-menopausal women, serum creatinine level increased with increasing FSH quartile, which was accompanied by a decrease in estimated glomerular filtration rate (eGFR) (p for trend <0.001); moreover, the prevalence of declined eGFR (<90 ml/min/1.73 m²) and chronic kidney disease (CKD; eGFR <60 ml/min/1.73 m²) increased (p for trend <0.001). Even after adjusting for confounders, the odds ratios (ORs) of declined eGFR and CKD increased with increasing FSH quartiles in post-menopausal women. The ORs of declined eGFR (OR=2.19, 95% confidence interval [CI]: 1.63-2.92) and CKD (OR=10.09, 95% CI: 2.28-44.65) in the highest FSH quartile were approximately 2- and 10-fold higher, respectively, than in the lowest FSH quartile (p<0.05). After stratifying post-menopausal women by median age (61 years), the OR for declined eGFR for each FSH quartile in the older group was higher than that for the corresponding FSH quartile in the younger group.

CONCLUSIONS

A high circulating FSH level is an independent risk factor for renal dysfunction in women after menopause. Additionally, aging may aggravate the association of high FSH levels with reduced renal function in post-menopausal women.

The Relationship Between Thyroid Function and Metabolic Syndrome and Its Components: A Cross-Sectional Study in a Chinese Population

OBJECTIVE

The present study examined the relationship between thyroid function status and the prevalence of metabolic syndrome in a Chinese population.

METHODS

Cross-sectional data were obtained from the Thyroid Disease, Iodine Nutrition and Diabetes Epidemiology (TIDE) Survey. A total of 62,408 subjects aged ≥18 years were enrolled. Differences in metabolic indicators and the prevalence of metabolic syndrome according to sex and thyroid function status were compared. Logistic regression was used to analyze the influence of thyroid function on metabolic syndrome and its components.

RESULTS

The prevalence of metabolic syndrome was generally higher in men than women. Overt hyperthyroidism and subclinical hypothyroidism had a significant effect on metabolism in men. Body mass index (BMI), waist circumference, and triglycerides (TGs) were significantly lower in men in the overt hyperthyroidism group, and BMI, waist circumference, systolic blood pressure (SBP) and TGs were higher in men in the subclinical hypothyroidism group than men in the normal group. Overt and subclinical hypothyroidism had significant impacts on metabolic components in women. BMI, waist circumference, TGs, SBP and DBP in the subclinical and overt hypothyroidism groups were significantly higher than the euthyroid group in women. The relative risk of abdominal obesity and hypertriglyceridemia was increased in women with hypothyroidism. Thyroid dysfunction had different effects on metabolic syndrome and its components before and after menopause.

CONCLUSION

Thyroid function had important effects on the prevalence of metabolic syndrome. Women with hypothyroidism, especially post-menopausal women, had a higher risk of metabolic syndrome than men.

A Novel Hypothesis: A Role for Follicle Stimulating Hormone in Abdominal Aortic Aneurysm Development in Postmenopausal Women

An abdominal aortic aneurysm (AAA) is a dilatation of the abdominal aorta, which can potentially be fatal due to exsanguination following rupture. Although AAA is less prevalent in women, women with AAA have a more severe AAA progression compared to men as reflected by enhanced aneurysm growth rates and a higher rupture risk. Women are diagnosed with AAA at an older age than men, and in line with increased osteoporosis and cardiovascular events, the delayed AAA onset has been attributed to the reduction of the protective effect of oestrogens during the menopausal transition. However, new insights have shown that a high follicle stimulating hormone (FSH) level during menopause may also play a key role in those diseases. In this report we hypothesize that FSH may aggravate AAA development and progression in postmenopausal women via a direct and/or indirect role, promoting aorta pathology. Since FSH receptors (FSHR) are reported on many other cell types than granulosa cells in the ovaries, it is feasible that FSH stimulation of FSHR-bearing cells such as aortic endothelial cells or inflammatory cells, could promote AAA formation directly. Indirectly, AAA progression may be influenced by an FSH-mediated increase in osteoporosis, which is associated with aortic calcification. Also, an FSH-mediated decrease in cholesterol uptake by the liver and an increase in cholesterol biosynthesis will increase the cholesterol level in the circulation, and subsequently promote aortic atherosclerosis and inflammation. Lastly, FSH-induced adipogenesis may lead to obesity-mediated dysfunction of the microvasculature of the aorta and/or modulation of the periaortic adipose tissue. Thus the long term increased plasma FSH levels during the menopausal transition may contribute to enhanced AAA disease in menopausal women and could be a potential novel target for treatment to lower AAA-related events in women.

First-in-class humanized FSH blocking antibody targets bone and fat

Blocking the action of FSH genetically or pharmacologically in mice reduces body fat, lowers serum cholesterol, and increases bone mass, making an anti-FSH agent a potential therapeutic for three global epidemics: obesity, osteoporosis, and hypercholesterolemia. Here, we report the generation, structure, and function of a first-in-class, fully humanized, epitope-specific FSH blocking antibody with a K _D of 7 nM. Protein thermal shift, molecular dynamics, and fine mapping of the FSH-FSH receptor interface confirm stable binding of the Fab domain to two of five receptor-interacting residues of the FSHβ subunit, which is sufficient to block its interaction with the FSH receptor. In doing so, the humanized antibody profoundly inhibited FSH action in cell-based assays, a prelude to further preclinical and clinical testing.

FSHR ablation induces depression-like behaviors

Alteration in reproductive hormones profile is associated with the increasing risk of menopausal depression in women. Serum follicle-stimulating hormone (FSH) level is changed during the menopause transition, while the effect of FSH on menopausal depression has remained undefined. In this study we investigated whether or how FSH affected menopausal depression in postmenopausal (ovariectomized) FSHR knockout mice (Fshr^−/−). We found that Fshr^−/− mice displayed aggravated depression-like behaviors, accompanied by severe oxidative stress in the whole brain, resulted from significantly reduced glutamate cysteine ligase modifier subunit (GCLm) in glutathione synthesis and glucose-6-phosphate dehydrogenase (G6PD) in NADP/NADPH transition. Importantly, administration of ROS scavenger N-acetyl cysteine (NAC, 150 mg · kg⁻¹ · d⁻¹, i.p. for 12 weeks) attenuated the depression-like behaviors of Fshr^−/− mice. Consistent with these in vivo experiment results, we found that pretreatment with FSH (50, 100 ng/mL) dose-dependently increased protein levels of GCLm and G6PD, and decreased the ROS production in N2a mouse neuroblastoma cells. These findings demonstrate that FSH signaling is involved in pathogenesis of menopausal depression, and likely to maintain the redox-optimized ROS balance in neurons.

Serum Follicle-Stimulating Hormone Levels Are Associated with Cardiometabolic Risk Factors in Post-Menopausal Korean Women

Menopause compounds many cardiometabolic risk factors through endogenous estrogen withdrawal. This study aimed to find the association between serum follicle-stimulating hormone (FSH) levels and cardiometabolic risk factors in post-menopausal Korean women. A total of 608 post-menopausal women from eight randomized double-blind, placebo-controlled clinical trials on menopause during the year 2012–2019 were analyzed. Cardiometabolic risk factors such as body mass index, waist circumference, systolic blood pressure, fasting glucose, triglycerides (TG), high density lipoprotein-cholesterol (HDL-C), and TG/HDL-C ratio were significantly improved as the FSH quartiles increased. Metabolic syndrome (MetS) and the number of components of MetS decreased as FSH quartiles increased. In regression analysis, FSH level was negatively associated with cardiometabolic risk factors including body mass index, body weight, waist circumference, fasting glucose and TG, while it was positively associated with HDL-C. The odds ratio of MetS in the first quartile of FSH was 2.682 compared with that in the fourth quartile of FSH in a logistic regression model. Serum FSH levels had a negative correlation with cardiometabolic risk factors in post-menopausal Korean women, suggesting that a low FSH can be a predictor for cardiovascular disease in post-menopausal women.

Follicle-Stimulating Hormone Positively Associates with Metabolic Factors in Perimenopausal Women

OBJECTIVE

Menopause is associated with the increased risk of metabolic syndrome (MetS) and cardiovascular (CV) disease. Most studies have focused the postmenopausal women and the relationships among estrogen, androgen, and Mets risk. The main aim of the study was to investigate the Mets risk in perimenopausal women and whether the variation of FSH is associated with metabolic factors.

METHODS

A single-center cross-sectional retrospective analysis including 154 premenopausal women and 124 perimenopausal women was performed.

RESULTS

The prevalence of Mets in the perimenopausal group was much higher than the premenopausal group (49.19% vs. 35.71%, p = 0.023). The prevalence of central obesity and NAFLD also increased in the perimenopausal group than in the premenopausal group. We grouped the population by FSH tertiles; compared with women in the lowest tertile, women in the highest tertile had higher age, WC, serum TC, LDL-C, AST, ALT, and creatine levels. The prevalence of hypertriglyceridemia, raised BP and Mets also increased in the highest tertile group. Further, we subdivided the perimenopausal women according to FSH tertiles. Compared with perimenopausal women in the lowest tertile, the prevalence of raised BP significantly increased in the highest tertile.

CONCLUSIONS

The risk of Mets increased in perimenopausal females than in premenopausal women. And a higher FSH level was associated with higher WC, TG, BPs, and the risk of Mets in perimenopausal women. Elevated FSH level appears to be a risk factor of MetS biomarkers in perimenopausal women.

Triglyceride to high-density lipoprotein cholesterol ratio is associated with incident diabetes in men: A retrospective study of Chinese individuals

AIMS/INTRODUCTION

Dyslipidemia is commonly present in type 2 diabetes mellitus patients. Recently, the triglyceride : high-density lipoprotein cholesterol (TG/HDL-C) ratio, a novel parameter of lipid abnormality, has been seen as an independent predictor for incident diabetes. However, the correlation of the TG/HDL-C ratio with incident diabetes in the Chinese population and how this relationship is impacted by sex have been rarely studied. In the present study, the correlation of the TG/HDL-C ratio with incident diabetes is investigated between different sexes of the Chinese population.

MATERIALS AND METHODS

A total of 116,855 participants who were free of diabetes at baseline were enrolled in the study. The participants were grouped by the median value (0.82) of the TG/HDL-C ratio. Then, participants were further analyzed according to their sex. Cumulative incidence and person-years incidence were used to express the incidence rate. The predictive value of the TG/HDL-C ratio for incident diabetes was probed by the Cox regression proportional hazards model.

RESULTS

The mean age of the participants was 44.1 ± 12.9 years, and 53% of participants (n = 62,868) were the men. A total of 2,685 incident diabetes cases occurred during the 3.1 years of the median follow-up period. The cumulative incidence in total incident diabetes patients, men and women was 2.30% (2.21-2.38%), 3.01% (2.87-3.14%) and 1.47% (1.37-1.57%), respectively. After the adjustment of multivariate factors, the multivariate Cox regression analysis results showed that a higher TG/HDL-C ratio was the independent predictive factor of incident diabetes in men (hazard ratio 1.30, 95% confidence interval 1.03-1.64), compared with women (hazard ratio 0.85, 95% confidence interval 0.53-1.38).

CONCLUSIONS

Among the Chinese population, the TG/HDL-C ratio is an independent predictor for incident diabetes in male patients.

FSH-metabolic circuitry and menopause

FSH has a primary function in procreation, wherein it induces estrogen production in females and regulates spermatogenesis in males. However, in line with our discoveries over the past decade of non-unitary functions of pituitary hormones, we and others have described hitherto uncharacterized functions of FSH. Through high-affinity receptors, some of which are variants of the ovarian FSH receptor (FSHR), FSH regulates bone mass, adipose tissue function, energy metabolism, and cholesterol production in both sexes. These newly described actions of FSH may indeed be relevant to the pathogenesis of bone loss, dysregulated energy homeostasis, and disordered lipid metabolism that accompany the menopause in females and aging in both genders. We are therefore excited about the possibility of modulating circulating FSH levels toward a therapeutic benefit for a host of age-associated diseases, including osteoporosis, obesity and dyslipidemia, among other future possibilities.