Epidemiological And Mechanism Research On Roles Of Follicle Stimulating Hormone In Regulating Renal Function

Background: Estrogen withdraw in aging women contributes to the progression of chronic kidney disease(CKD)but fails to fully explain it.In fact,during postmenopause period,follicle-stimulating hormone(FSH)level rises sharply in parallel.Recent studies begin to focus on FSH that is more likely to play roles in the menopause-related dysfunction.However,the data between FSH and CKD is not available.Based on the SPECT-China survey,the present study aims to investigate whether FSH participates in renal development during postmenopausal period,and further explores the mechanism of FSH-mediated renal dysfunction.Methods: In epidemiological study,a total of 3055 postmenopausal women were selected,all of who have finished the questionnaire and sample collection.The associations of FSH with e GFR were assessed by linear regression.FSH served as independent variable,and e GFR served as dependent variable.The associations of FSH quartiles with decreased e GFR and CKD were assessed by logistic regression.In vivo,8-week female C57BL/6 mice were randomly assigned into four groups: sham operation(Sham),bilateral ovariectomy(OVX),OVX+Gn RHa and OVX+Gn RHa+FSH,6-8/group.High circulating FSH level model was established by surgery and injection with Gn RHa and recombinant FSH in ovariectomized mice to determine the effect of FSH on kideny.After 6-week experimental period,urine,blood and kidney sample were collected.Biochemical indices were measured.FSHR location and expression was assessed by immunohistochemistry.ECM deposition was evaluated by Masson and Sirius red stainning.q PCR and Western blot were performed to investigate the profibrotic gene expression.In vitro,human HK-2 cells were choosed.Western blot was performed to explore the FSHactivated signaling pathways,and LY294002 and FSHR si RNA was used to validate the effect of signaling moleculars silence on FSH-mediated phenotype changes.Besides,q PCR and transwell test were used to assess macrophage polarization and migration.Results: 1.With the increase of FSH quartiles,the prevalence of decreased e GFR and CKD gradually increased(P for trend <0.001),and rised from 61.1 to 75.2%,4.9% to 10.1%,respectively.2.Based on clinical data analyses,we found that there was a strong negative correlation between e GFR and FSH levels(P<0.001),especially independent of age,LH,testosterone and estradiol.Odd risks(OR)of decreased e GFR and CKD in the highest quartile of FSH increased approximately 3-fold compared with that in the lowest quartile(P for trend <0.001).3.Functional FSHR was detected in renal tubular epithelial cell.In vivo,high circulating FSH promoted a phenotype of tubulointerstitial fibrosis,characterized by increase in kidney index,24 h uric protein,serum Cr,serum BUN,as well as ECM deposition.Similar results obtained from cultured HK-2 cells,FSH increased the transcriptional and protein expressions of profibrotic mediators(Collagen IV,Fibronectin and PAI-1).4.FSH increased Collagen IV,Fibronectin and PAI-1 m RNA and protein expressions in HK-2 cell.FSH-mediated renal fibrosis was through activation of AKT/GSK-3?/?-catenin pathway.LY294002,a common PI3K/AKT pathway inhibitor,and FSHR si RNA,could attenuate AKT/GSK-3?/?-catenin pathway and reverse these fibrotic phenotypes.5.Several toxic factors secreted by innate macrophages,such as i NOS,TNF-? and IL-1?,were significantly increased in high circulating FSH group compared to low circulating FSH group.FSH enhanced macrophages migration,and FSH-stimulated HK-2 secreted chemokine,IL-8,promoted macrophages migration to exacerbate tubulointerstitial fibrosis.Conclusion:1.High circulating FSH level increased the risks of decreased e GFR and CKD in postmenopausal female population,and this positive correlation was independent of age,total T,estradiol,etc.2.Functional FSHR was expressed in renal tubular epithelial cells and high circulating FSH promoted a phenotype of tubulointerstitial fibrosis.3.FSH aggravated renal dysfunction and tubulointerstitial fibrosis via FSHR-mediated AKT/GSK-3?/?-catenin pathway.4.FSH stimulated macrophages polarization from M0 to M1 and migration to exacerbate FSH-mediated interstitial fibrosis.