DNAJB11 promotes the synthesis of FOXL2-induced estradiol in ovarian granulosa cells / 医学研究生学报

ABSTRACT

Objective Transcription factor forkhead box L 2 (FOXL2) is a key regulator of granulosa cells (GCs) estrogen syn-thesis and function maintenance .However, the FOXL2 protein expres-sion and function regulation mechanism are unknown .We explored how DNAJB11 regulates estrogen synthesis of granulosa cells with immunoprecipitation , immunofluorescent staining and luciferase re-porter gene. Methods The expression and localization of DNAJB 11 was detected by immunohistochemistry staining in isolated mouse ovary tissues .we use immunoprecipitation , immunofluorescence staining and luciferase reporter gene assay to investigate the mechanism of DNAJB11, a member of the endoplasmic reticulum Hsp 40 /DnaJ family, regulating the estrogen synthesis in granulosa cells . Results DNAJB11 is expressed in the mouse ovary and granulosa cells .Follicle-stimulating hormone (FSH) promotes DNAJB11 ex-pression in a time and concentration dependent manner and induces endogenous DNAJB 11 protein translocation from the ER to the nu-cleus in KGN cells.Moreover, Adenovirus-mediated overexpression of DNAJB11 did not affect the proliferation of granulosa cells .How-ever, the concentration of estrogen in granulosa cells was affected by concentration -dependent and subcellular localization-dependent manner (10749±801.7 pg/mL vs 14217±1218.0 pg/mL P<0.01).Immunoprecipitation assay confirmed that DNAJB11 binds to FOXL2 in granulosa cells .When overexpressed in the nucleus of granulosa cells , DNAJB11 could significantly enhance the stability of FOXL2 (P<0.05) and promote FOXL2-mediated activity of Cyp19A1 promoter (P<0.01), while the expression of DNAJB11 in the nucleus increased the expression of Cyp 19A1 protein by 1.5 times ( P<0.05) . Conclusion These results demonstrate that DNAJB 11 was a new binding molecule of transcription factor FOXL 2 and regulated FOXL 2 protein stability and transcription activity .