Role and mechanism of the p-JAK2/p-STAT3 signaling pathway in follicular development in PCOS rats

Objective: To identify the association between the phosphorylated Janus kinase 2/phosphorylated signal trans-ducer and activator of transcription (p-JAK2/p-STAT3) signaling pathway and follicular development in poly -cystic ovary syndrome (PCOS) rats, and explore the underlying mechanism. To evaluate the role of exogenous JAK2 inhibitor AG490 in the model and the associations among luteinizing hormone/choriogonadotropin re-ceptor (LHCGR), follicle-stimulating hormone receptor (FSHR), cytochrome P450 17 alpha (CYP17a), cytochrome P450 19 (CYP19), and PCOS.Results: Rat models of PCOS was established. PCOS rats were intraperitoneally treated with double-distilled water (ddH2O)/DMSO/AG490. The rate of ovarian morphological recovery in the AG490 group was significantly higher compared with the DMSO group (83.3 % vs 9.1 %, X2 =12.68, P < 0.001). Moreover, the short in the time the estrous cycle was resumed in the AG490 group (hazard ratio = 16.32, P < 0.001) compared with the DMSO group. Compared with the controls, p-JAK2, p-STAT3, LHCGR, and CYP17a expression levels were increased whereas that of FSHR and CYP19 were decreased in the ovaries of PCOS rats. However, an opposite trend was observed after treatment with AG490. Software prediction revealed that the p-STAT3 bound to the promoter regions of LHCGR, FSHR, CYP17a, and CYP19 genes. This finding was confirmed by results of correlation analysis (R = 0.834,-0.836, 0.875 and-0.712, respectively, all P < 0.001).Conclusion: This study demonstrated that the p-JAK2/p-STAT3 signaling pathway was involved in follicular development in PCOS rats by upregulating LHCGR and CYP17a expression, and downregulating that of FSHR and CYP19. AG490 treatment exerted beneficial effects. LHCGR, FSHR, CYP17a, and CYP19 are candidate genes associated with follicular development in PCOS rats.