Long non-coding RNA PWRN1 affects ovarian follicular development by regulating the function of granulosa cells

Research question What is the role of Prader-Willi region non-protein coding RNA 1 (PWRN1) in ovarian follicular development and its molecular mechanism? Design The expression and localization of PWRN1 were detected in granulosa cells from patients with different ovarian functions, and the effect of interfering with PWRN1 expression on cell function was detected by culturing granulosa cells in vitro. Furthermore, the effects of interfering with PWRN1 expression on ovarian function of female mice were explored through in vitro and in vivo experiments. Results The expression of PWRN1 was significantly lower in granulosa cells derived from patients with diminished ovarian reserve (DOR) compared to patients with normal ovarian function. By in vitro culturing of granulosa cells, the results showed that the downregulation of PWRN1 promoted granulosa cell apoptosis, caused cell cycle arrested in S-phase, generated high levels of autophagy, and led to significant decrease in steroidogenic capacity, including inhibition of estradiol and progesterone production. In addition, sirtuin1 over-expression could partially reverse the inhibitory effect of PWRN1 downregulation on cell proliferation. The results of in vitro culturing of newborn mouse ovary showed that the down-regulation of PWRN1 could slow down the early follicular development. Further, by injecting AAV-sh-PWRN1 in mouse ovarian bursa, the estrous cycle of mouse was affected, and the number of oocytes retrieved after ovulation induction and embryos implanted after mating was significantly reduced. Conclusion This study systematically elucidated the novel mechanism by which lncRNA PWRN1 participates in the regulation of granulosa cell function and follicular development.