Differential expression of genes involved in steroidogenesis pathway in human oocytes obtained from patients with polycystic ovaries

Luteinizing Hormone Surge-Induced Krüppel-like Factor 4 Inhibits Cyp17A1 Expression in Preovulatory Granulosa Cells

Previous in vivo and in vitro studies have demonstrated a dramatic up-regulation of Krüppel-like factor 4 (Klf4) in rat preovulatory granulosa cells (GCs) after LH/hCG treatment and its role in regulating Cyp19A1 expression during the luteal shift in steroidogenesis. In this study, we examined whether Klf4 also mediates the LH-induced repression of Cyp17A1 expression in primary rat preovulatory GCs. In response to LH treatment of GCs in vitro, Cyp17A1 expression declined to less than half of its initial value by 1 h, remaining low for 24 h of culture. Overexpression of Klf4 decreased basal and Sf1-induced Cyp17A1 expressions and increased progesterone secretion. Reduction of endogenous Klf4 by siRNA elevated basal Cyp17A1 expression but did not affect LH-stimulated progesterone production. Overexpression of Klf4 also significantly attenuated Sf1-induced Cyp17A1 promoter activity. On the other hand, mutation of the conserved Sp1/Klf binding motif in the promoter revealed that this motif is not required for Klf4-mediated repression. Taken together, these data indicate that the Cyp17A1 gene may be one of the downstream targets of Klf4, which is induced by LH in preovulatory GCs. This information may help in identifying potential targets for preventing the molecular changes occurring in hyperandrogenic disorders.

Expression of genes in the AKT signalling pathway in human oocytes from patients with polycystic ovaries

Polycystic ovary syndrome is an endocrine disorder commonly found among females of reproductive age. Different factors have been correlated with this syndrome, although the aetiology of the disease is still unrecognized with both environmental and hereditary factors leading to the progression. Hormonal effects of the AKT pathway have made it an interesting study unit for PCOS cases. The aim of this study was to investigate the expression patterns of genes involved in the AKT pathway, including IRS1, IRS2, AKT1 and AKT2. In total, 13 human oocytes were collected for this study at the meiosis II stage, in which seven of them were collected from individuals with polycystic ovaries and the rest formed the control group of individuals with no signs of polycystic ovaries. RNA was extracted from oocytes and then the RNA was converted into cDNA for the real-time PCR process. Expression levels of four genes in the AKT pathway, in addition to housekeeping gene (ACTB), were evaluated. Expression levels of each gene were quantified using real-time PCR and statistical analysis was performed. The results of this study showed that there was no significant correlation between the expression of genes in oocyte samples obtained from patients with polycystic ovaries and the control group. This study is the first to evaluate the expression levels of genes involved in the AKT pathway in human oocyte samples. Therefore, it provides crucial information to form the basis of further studies.

Whole exome and targeted sequencing reveal novel mutations associated with inherited PCOS condition in an Indian cohort

A cohort of polycystic ovary syndrome (PCOS) women presents themselves with persistent abnormal reproductive hormone levels and has a familial representation of characteristics. In our study, we have aimed to identify genetic variants which are inherited across such PCOS families and also validate them among Indian population. Independent discovery was done by whole exome sequencing in a three-generation family (Family P01). Validation was done by targeted sequencing at 30,000x using HaloPlex panel in 9 families (P01-P09). The variants were filtered and reported according to American College of Medical Genetics and Genomics (ACMG) guidelines. Mutation burden analysis and in-silico functional analyses were performed. After careful annotation analyses, we report 24 likely pathogenic variants from 21 genes, out of which 8 are novel structural variants, 14 missense variants and 2 intronic variants. Out of these, 3 variants from the genes FSHR, SCARB1, and INSR are involved in the ovarian steroidogenesis pathway and 5 variants from genes DFFB, ACTG1, GPX4, CYC1 and ALDOA directly or indirectly trigger the apoptotic pathways. Three ovarian steroidogenesis variants, FSHR, SCARB1 and INSR were screened among Indian women using a case-control approach to validate these variant's pathogenicity in Indian PCOS women. Variants of SCARB1 and INSR were found to be pathogenic to Indian PCOS women, while FSHR variants did not show significant association to PCOS cases.