Burning Fat and Building Bone by FSH Blockade

Neuroendocrinology of bone

The past decade has witnessed significant advances in our understanding of skeletal homeostasis and the mechanisms that mediate the loss of bone in primary and secondary osteoporosis. Recent breakthroughs have primarily emerged from identifying disease-causing mutations and phenocopying human bone disease in rodents. Notably, using genetically-modified rodent models, disrupting the reciprocal relationship with tropic pituitary hormone and effector hormones, we have learned that pituitary hormones have independent roles in skeletal physiology, beyond their effects exerted through target endocrine glands. The rise of follicle-stimulating hormone (FSH) in the late perimenopause may account, at least in part, for the rapid bone loss when estrogen is normal, while low thyroid-stimulating hormone (TSH) levels may contribute to the bone loss in thyrotoxicosis. Admittedly speculative, suppressed levels of adrenocorticotropic hormone (ACTH) may directly exacerbate bone loss in the setting of glucocorticoid-induced osteoporosis. Furthermore, beyond their established roles in reproduction and lactation, oxytocin and prolactin may affect intergenerational calcium transfer and therefore fetal skeletal mineralization, whereas elevated vasopressin levels in chronic hyponatremic states may increase the risk of bone loss.. Here, we discuss the interaction of each pituitary hormone in relation to its role in bone physiology and pathophysiology.

Rationality of the ethanol precipitation process in modern preparation production of Zishui-Qinggan decoction evaluated by integrating UPLC-QTOF-MS/MS-based chemical profiling/serum pharmacochemistry and network pharmacology

INTRODUCTION

Zishui-Qinggan decoction (ZQD) is a classical traditional Chinese medicine formula (TCMF) for alleviating menopausal symptoms (MPS) induced by endocrine therapy in breast cancer patients. In the production of TCMF modern preparations, ethanol precipitation (EP) is a commonly but not fully verified refining process.

OBJECTIVES

Chemical profiling/serum pharmacochemistry and network pharmacology approaches were integrated for exploring the rationality of the EP process in the production of ZQD modern preparations.

MATERIAL AND METHODS

Ultra-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS) was applied to identify the chemical profiles and absorbed components of ZQD. Network pharmacology was used to identify targets and pathways related to MPS-relieving efficacy.

RESULTS

The chemicals of ZQDs without/with EP process (referred to as ZQD-W and ZQD-W-P, respectively) were qualitatively similar with 89 and 87 components identified, respectively, but their relative contents were different; 51 components were detectable in the serum of rats orally administered with ZQD-W, whereas only 19 were detected in that administered with ZQD-W-P. Key targets, such as AKT1, and pathways, such as the PI3K-Akt signalling pathway, affected by ZQD-W and ZQD-W-P were similar, while the neuroactive ligand-receptor interaction pathway among others and the MAPK signalling pathway among others were specific pathways affected by ZQD-W and ZQD-W-P, respectively. The specifically absorbed components of ZQD-W could combine its specific key targets.

CONCLUSION

The EP process quantitatively altered the chemical profiles of ZQD, subsequently affected the absorbed components of ZQD, and then affected the key targets and pathways of ZQD for relieving MPS. The EP process might result in variation of the MPS-relieving efficacy of ZQD, which deserves further in vivo verification.

Effects of follicle-stimulating hormone on energy balance and tissue metabolic health after loss of ovarian function

Loss of ovarian function imparts increased susceptibility to obesity and metabolic disease. These effects are largely attributed to decreased estradiol (E2), but the role of increased follicle-stimulating hormone (FSH) in modulating energy balance has not been fully investigated. Previous work that blocked FSH binding to its receptor in mice suggested this hormone may play a part in modulating body weight and energy expenditure after ovariectomy (OVX). We used an alternate approach to isolate the individual and combined contributions of FSH and E2 in mediating energy imbalance and changes in tissue-level metabolic health. Female Wistar rats were ovariectomized and given the gonadotropin releasing hormone (GnRH) antagonist degarelix to suppress FSH production. E2 and FSH were then added back individually and in combination for a period of 3 wk. Energy balance, body mass composition, and transcriptomic profiles of individual tissues were obtained. In contrast to previous studies, suppression and replacement of FSH in our paradigm had no effect on body weight, body composition, food intake, or energy expenditure. We did, however, observe organ-specific effects of FSH that produced unique transcriptomic signatures of FSH in retroperitoneal white adipose tissue. These included reductions in biological processes related to lipogenesis and carbohydrate transport. In addition, rats administered FSH had reduced liver triglyceride concentration (P < 0.001), which correlated with FSH-induced changes at the transcriptomic level. Although not appearing to modulate energy balance after loss of ovarian function in rats, FSH may still impart tissue-specific effects in the liver and white adipose tissue that might affect the metabolic health of those organs.NEW & NOTEWORTHY We find no effect of follicle-stimulating hormone (FSH) on energy balance using a novel model in which rats are ovariectomized, subjected to gonadotropin-releasing hormone antagonism, and systematically given back FSH by osmotic pump. However, tissue-specific effects of FSH on adipose tissue and liver were observed in this study. These include unique transcriptomic signatures induced by the hormone and a stark reduction in hepatic triglyceride accumulation.

Elevated circulating follicle stimulating hormone level is associated with dyslipidemia in male type 2 diabetes mellitus patients: A cross-sectional study

AIMS

Type 2 diabetes mellitus (T2DM) commonly combines with dyslipidemia, and both are known as the risk factors of cardiovascular events and aggravate the arteriosclerosis progression. In this study, we investigated the relationship between follicle-stimulating hormone (FSH) and lipid profiles in male T2DM patients.

MATERIALS AND METHODS

We collected clinical data of male T2DM patients in the Chinese Han population hospitalised from January 2018 to June 2020. A total of 963 patients with a mean age of 58.89 ± 12.25 years old were enroled in this study.

RESULTS

The results showed that the levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein (LDL)-C levels were decreased gradually from the highest quartile groups (Q4) to Q1 group relevant to luteinising hormone and FSH, and no significant difference was observed in high-density lipoprotein-C levels among Q4-Q1 groups. Sub-groups analysis showed that, with the increased FSH level, TC, TG, and LDL-C levels were increased in the elder group (40-59 years old) than those in the younger group (20-39 years old). Spearman's analysis revealed a positive correlation between FSH and the levels of TC, TG, and LDL-C (r = 0.354, r = 0.336, r = 0.312, p < 0.001, respectively). The effect of FSH is independent of the changes in total testosterone level. Multivariate analysis found that increased FSH levels (≥9.26 mIU/mL) and decreased total testosterone levels (<13.30 nmol/L) were positively correlated with high TC, TG, and LDL-Cemia (OR = 4.014, 1.565, 1.602, 1.660, 2.127, 1.322, respectively, p < 0.05).

CONCLUSIONS

Our data suggest that high serum FSH level in male T2DM patients could be a potential independent risk factor correlated with the elevated TC, TG, and LDL-C.

Follicle-Stimulating Hormone Provokes Macrophages to Secrete IL-1β Contributing to Atherosclerosis Progression

Abnormally high follicle-stimulating hormone (FSH) has been reported to associate with cardiovascular diseases in prostate cancer patients with specific androgen deprivation therapy and in menopausal women. All of the cardiovascular diseases were involved in atherosclerosis. However, the pathogenic mechanism of FSH-associated atherosclerosis remains uncertain. Apolipoprotein E-deficient mice were chosen to develop atherosclerosis, of which the plaques were analyzed with administration of short- and long-term FSH imitating androgen deprivation therapy-induced and menopausal FSH elevation. The study showed that short- and long-term exposure of FSH significantly accelerated atherosclerosis progression in apolipoprotein E-deficient mice, manifested as strikingly increased plaques in the aorta and its roots, increased macrophage content, reduced fibrin, and an enlarged necrotic core, suggesting a decrease in plaque stability. Furthermore, expression profiles from the Gene Expression Omnibus GSE21545 dataset revealed that macrophage inflammation was tightly associated with FSH-induced atherosclerotic progression. The human monocyte cell line THP-1 was induced by PMA and worked as a macrophage model to detect inflammatory factors and cellular functions. FSH remarkably promoted the expression of IL-1β in macrophages and strikingly increased the chemotactic migratory capacity of macrophages toward MCP-1, but the promigratory capacity of FSH was attenuated in foam cells. Overall, we revealed that FSH significantly promoted the inflammatory response and migration of macrophages, thereby provoking atherosclerosis development.

Relationship between GDF15 level and bone metabolism in postmenopausal Chinese women

Background: Growth differentiation factor 15 (GDF15), is a newly identified member of the transforming growth factor-beta (TGF-β) family. It circulates as a 24.5-kDa homodimer. However, the function of GDF15 in bone metabolism remains unclear. In this study, we investigated the function of GDF15 in postmenopausal Chinese women.Methods: We measured serum GDF15 levels, bone mineral density (BMD), and bone turnover markers in 201 postmenopausal Chinese women ranging in age from 47 to 80 years.Results: The concentration of serum GDF15 increased with age. Growth differentiation factor 15 levels displayed a negative correlation with lumbar spine, femoral neck, and total hip BMD. After adjusting for age, this association still existed and was significant. We identified age, GDF15, body mass index (BMI), and estradiol to be associated with BMD. Furthermore, we found that GDF15 levels had a significant negative relationship with bone alkaline phosphatase (BAP) levels; this relationship remained significant after adjustment. However, there was no significant correlation between levels of GDF15 and N-terminal telopeptide of type I collagen (NTX).Conclusions: For postmenopausal Chinese women, GDF15 is a negative predictor of BMD and has a negative correlation with bone formation biomarker BAP. In other words, GDF15 exerts negative regulation on bone mass by inhibiting bone formation.

Follicle-stimulating hormone impairs dental pulp stem cells odontogenic differentiation

In addition to bone, the dentin‐pulp complex is also influenced by menopause, showing a decreased regenerative capacity. High levels of follicle‐stimulating hormone (FSH) during menopause could directly regulate bone metabolism. Here, the role of FSH in the odontogenic differentiation of the dentin‐pulp complex was investigated. Dental pulp stem cells (DPSCs) were isolated. CCK‐8 assays, cell apoptosis assays, Western blotting (WB), real‐time RT‐PCR, alkaline phosphatase activity assays, and Alizarin Red S staining were used to clarify the effects of FSH on the proliferation, apoptosis and odontogenic differentiation of the DPSCs. MAPK pathway‐related factors were explored by WB assays. FSH and its inhibitor were used in OVX rats combined with a direct pulp‐capping model. HE and immunohistochemistry were used to detect reparative dentin formation and related features. The results indicated that FSH significantly decreased the odontogenic differentiation of the DPSCs without affecting cell proliferation and apoptosis. Moreover, FSH significantly activated the JNK signalling pathway, and JNK inhibitor partly rescued the inhibitory effect of FSH on DPSC differentiation. In vivo, FSH treatment attenuated the dentin bridge formation and mineralization‐related protein expression in the OVX rats. Our findings indicated that FSH reduced the odontogenic capacity of the DPSCs and was involved in reparative dentinogenesis during menopause.

Positive Effect of Gushukang on Type-H Vessel and Bone Formation

Gushukang (GSK) is a traditional herbal compound used in Chinese medicine for the treatment of osteoporosis. Numerous studies have been conducted to elucidate the effects of GSK, but the mechanisms underlying these effects remain unclear. In the present study, we cultured osteoblasts and osteoclasts with low and high doses of GSK, and also administered 3-month-old mice with 4 and 8 g/kg/day of GSK solution. Gushukang was found to promote osteoblast differentiation and inhibit osteoclast differentiation in vitro. In vivo, mice in the GSK treatment groups showed an increase in bone mass, as measured by micro-computed tomography (Micro-CT). Tartrate resistant acid phosphatase (TRAP) staining and osteocalcin (OCN) staining experiments revealed decreased bone resorption and increased bone formation in the GSK treatment groups. In addition, we found a novel effect of GSK—it could induce type-H vessel formation in mice. The underlying mechanisms of these actions were further explored at the molecular level to investigate whether these effects were due to an overexpression of the hypoxia inducible factor-1 (HIF-1α). Our findings indicate the utility of GSK as a therapeutic for the prevention of osteoporosis.

Roles of follicle stimulating hormone and its receptor in human metabolic diseases and cancer

Follicle stimulating hormone (FSH) and its receptor (FSHR) play an important role in human metabolic diseases and cancer. Evidence showed that FSHR is not only distributed in ovary and testis but also in other cells or organs such as osteoclast, adipocytes, liver, pituitary cancer and so forth. Moreover, FSH is associated with lipogenesis, inflammation, insulin sensitivity, thermogenesis, skeletal metabolism, osteogenesis and ovarian cancer, all of which have been confirmed closely related to metabolic diseases or metabolic-related cancer. Therefore, FSH and FSHR may be potential therapeutic targets for metabolic diseases and metabolic-related cancer. Epidemiological researches revealed close relationship between FSH/FSHR and metabolic diseases or cancer. Experimental studies elucidated the underlying mechanism both in vivo and in vitro. We reviewed the recent researches and present an integrated framework of FSH/FSHR and metabolic diseases and cancer, which provides potential targets for the treatments of metabolic diseases and cancer.

The Role of Bone-Derived Exosomes in Regulating Skeletal Metabolism and Extraosseous Diseases

Bone-derived exosomes are naturally existing nano-sized extracellular vesicles secreted by various cells, such as bone marrow stromal cells, osteoclasts, osteoblasts, and osteocytes, containing multifarious proteins, lipids, and nucleic acids. Accumulating evidence indicates that bone-derived exosomes are involved in the regulation of skeletal metabolism and extraosseous diseases through modulating intercellular communication and the transfer of materials. Following the development of research, we found that exosomes can be considered as a potential candidate as a drug delivery carrier thanks to its ability to transport molecules into targeted cells with high stability, safety, and efficiency. This review aims to discuss the emerging role of bone-derived exosomes in skeletal metabolism and extraosseous diseases as well as their potential role as candidate biomarkers or for developing new therapeutic strategies.

Follicle-stimulating hormone promotes renal tubulointerstitial fibrosis in aging women via the AKT/GSK-3β/β-catenin pathway

Estrogen withdrawal in aging women contributes to the progression of chronic kidney disease (CKD). However, the effect of high circulating follicle‐stimulating hormone (FSH) levels on renal dysfunction remains unknown. In this study, blood samples from 3,055 postmenopausal women were collected and tested, which showed that there was a strong negative correlation between eGFR and FSH levels (p < 0.001), independent of LH, testosterone, and estradiol. Functional FSHR was detected in renal tubular epithelial cells. In vivo, high circulating FSH levels promoted a phenotype of tubulointerstitial fibrosis, characterized by increases in 24‐hr urine protein/creatinine ratio, serum Cr, serum BUN, and ECM deposition. Similar results obtained from cultured HK‐2 cells showed that FSH increased the transcriptional and protein expression of profibrotic mediators (collagen IV, fibronectin, and PAI‐1). This promotion of fibrosis by FSH occurred through the activation of AKT/GSK‐3β/β‐catenin pathway, which could be attenuated by silencing FSHR by siRNA or by LY294002 or MK2206. In addition, FSH‐stimulated HK‐2 cells secreted IL‐8, which promoted macrophage migration to exacerbate tubulointerstitial fibrosis. These results revealed a previously unknown effect of FSH on kidney injury, which may offer a critical insight into the development of CKD in aging postmenopausal women.

Osteoclastogenesis inhibition by mutated IGSF23 results in human osteopetrosis

OBJECTIVES

Osteopetrosis is a rare inherited skeletal disease characterized by increased bone mineral density due to the loss of osteoclast function or differentiation potential.

MATERIALS AND METHODS

The study involved a Chinese patient with osteopetrosis (the proband) and her immediate family members and 180 controls without osteopetrosis. Bone density of the femoral neck, lumbar spine and total body was measured using dual-energy x-ray absorptiometry. Osteoclast differentiation by the participants' peripheral blood mononuclear cells (PBMCs) was investigated using tartrate-resistant acid phosphatase (TRAP) staining. Osteoblast differentiation was examined with Alizarin Red S staining. Reverse transcription-quantitative PCR was used to amplify immunoglobulin superfamily member 23 (IGSF23), c-FOS and nuclear factor of activated T cells 1 (NFATC1).

RESULTS

We found a homozygous mutation (c.295C>T) in the IGSF23 gene in two osteopetrosis samples. The mutation led to the formation of a stop codon, causing loss of the immunoglobulin-like domain and the whole transmembrane domain. PBMCs from the proband (IGSF23^-/- ) exhibited poor ability for differentiating into mature osteoclasts in vitro. Overexpression of IGSF23 rescued the ability of IGSF23^-/- PBMCs to differentiate into osteoclasts. Moreover, knockdown of IGSF23 reversed the bone loss in OVX mice by injecting AAV-shIGSF23 into mice femoral bone marrow cavity. Furthermore, we also found that the IGSF23 mutation led to decreased c-Fos and NFATC1 expression levels by inhibiting the mitogen-activated protein kinase signalling pathways.

CONCLUSIONS

IGSF23-mediated osteoclast differentiation of PBMCs may serve as a potential target in osteoporosis therapy.

FSH Beyond Fertility

The traditional view of follicle-stimulating hormone (FSH) as a reproductive hormone is changing. It has been shown that FSH receptors (FSHRs) are expressed in various extra-gonadal tissues and mediate the biological effects of FSH at those sites. Molecular, animal, epidemiologic, and clinical data suggest that elevated serum FSH may play a significant role in the evolution of bone loss and obesity, as well as contributing to cardiovascular and cancer risk. This review summarizes recent data on FSH action beyond reproduction.

Extragonadal FSHR Expression and Function-Is It Real?

Expression of the follicle-stimulating hormone receptor (FSHR), besides gonadal tissues, has recently been detected in several extragonadal normal and tumorous tissues, including different types of primary and metastatic cancer and tumor vessel endothelial cells (TVEC). The suggested FSH actions in extragonadal tissues include promotion of angiogenesis, myometrial contractility, skeletal integrity, and adipose tissue accumulation. Non-malignant cells within cancer tissue have been shown to be devoid of FSHR expression, which implies a potential role of FSHR as a diagnostic, prognostic, or even a therapeutic tool. There are shared issues between several of the published reports questioning the validity of some of the conclusion. Firstly, protein expression of FSHR was performed solely with immunohistochemistry (IHC) using either an unavailable "in house" FSHR323 monoclonal antibody or poorly validated polyclonal antibodies, usually without additional methodological quality control and confirmations. Secondly, there is discrepancy between the hardly traceable or absent FSHR gene amplification/transcript data and non-reciprocal strong FSHR protein immunoreactivity. Thirdly, the pharmacological high doses of recombinant FSH used in in vitro studies also jeopardizes the physiological or pathophysiological meaning of the findings. We performed in this review a critical analysis of the results presenting extragonadal expression of FSHR and FSH action, and provide a rationale for the validation of the reported results using additional more accurate and sensitive supplemental methods, including in vivo models and proper positive and negative controls.

Modulation of Gonadotropins Activity by Antibodies

Gonadotropins are essential for reproduction control in humans as well as in animals. They are widely used all over the world for ovarian stimulation in women, spermatogenesis stimulation in men, and ovulation induction and superovulation in animals. Despite the availability of many different preparations, all are made of the native hormones. Having different ligands with a wide activity range for a given receptor helps better understand its molecular and cellular signaling mechanisms as well as its physiological functions, and thus helps the development of more specific and adapted medicines. One way to control the gonadotropins' activity could be the use of modulating antibodies. Antibodies are powerful tools that were largely used to decipher gonadotropins' actions and they have shown their utility as therapeutics in several other indications such as cancer. In this review, we summarize the inhibitory and potentiating antibodies to gonadotropins, and their potential therapeutic applications.

Association between brown adipose tissue and bone mineral density in humans

BACKGROUND

Brown adipose tissue (BAT) seems to play a role in bone morphogenesis. A negative association has been reported between BAT and bone mineral density (BMD) in women, but not in men. A panel of experts has recently published a set of recommendations for BAT assessment, and thus, to re-address previously reported associations is needed. This study aimed to investigate the association between cold-induced BAT ¹⁸F-Fluorodeoxyglucose (¹⁸F-FDG) uptake and BMD in young healthy adults.

METHODS

Ninety-eight healthy adults (68 women; 22 ± 2.2 years old; 24.3 ± 4.5 kg/m²) cold-induced BAT was assessed by means of an ¹⁸F-FDG positron emission tomography-computed tomography (PET-CT) scan preceded by a personalized cold stimulation. The cold exposure consisted in 2 h in a mild cold room at 19.5-20 °C wearing a water perfused cooling vest set 4 °C above the individual shivering threshold. Total body and lumbar spine BMD were assessed by a whole-body DXA scan.

RESULTS

We found no association between BMD and cold-induced BAT volume, mean, and maximal activity (all P > 0.1) in neither young and healthy men nor women. These results remained unchanged when adjusting by height, by body composition, and by objectively assessed physical activity. Sensitivity analyses using the criteria to quantify cold-induced BAT-related parameters applied in previous studies did not change the results.

CONCLUSIONS

In summary, our study shows that there is no association between cold-induced BAT and BMD in young healthy adults. Moreover, our data support the notion that previously shown associations between BAT and BMD in healthy non-calorically restricted individuals, could be driven by methodological issues related to BAT assessment and/or sample size limitations.