miR-92a-3p and miR-25-3p Sponges Up-regulate Kiss1 and Affect the Onset of Puberty and Estrous Cycle of Female Mice / 中国生物化学与分子生物学报

ABSTRACT

Kisspeptin, the neuropeptide produced by Kiss1 neurons in the hypothalamus, is involved in the neuroendocrine regulation of puberty initiation, reproductive system maturation, ovulation and other processes by influencing the secretion of gonadotropin-releasing hormone. Kiss1 gene expression is regulated by multiple trans-regulatory factors and epigenetics. Prediction and preliminary experiments have shown that the seed sequences of miR-92a-3p and miR-25-3p can directly bind to the 3′-UTR of Kiss1 and inhibit the expression of Kiss1. In order to further study the role of miR-92a-3p and miR-25-3p in the regulation of Kiss1, specific absorptive sponge vectors (sponge-miR-92a and sponge-miR-25) with inhibitory effects on miR-92a-3p and miR-25-3p were constructed to realize the functional loss of miRNA. Flow cytometry and dual luciferase reporter assays both confirmed that both sponge vectors could adsorb exogenous or endogenous target miRNAs very effectively. The sponge-miR-92a and sponge-miR-25 vectors are further packaged into the lentivirus LV-sponge-miR-92a and LV-sponge-miR-25. The results of real-time fluorescence quantitative PCR showed that the expression level of Kiss1 in the hypothalamic primary neurons infected by LV-sponge-miR-92a and LV-sponge-miR-25 was significantly up-regulated (P < 0. 05). After injecting LV-sponge-miR-92a into the hypothalamus, the time of female mouse vulva opening was significantly earlier (P<0. 05). The normal oestrus cycle of female mice with was disrupted by injections of LV-sponge-miR-92a and LV-sponge-miR-25 in the hypothalamus. In conclusion, we successfully constructed sponge vectors capable of effectively adsorbing miR-92a-3p and miR-25-3p, and demonstrated their role in removing the inhibition of miR-92a-3p and miR-25-3p on Kiss1. Hypothalamic sponge injection had a certain effect on both the time of vulva opening and the estrus cycle of female mice, suggesting that miR-92a-3p and miR-25-3p may play an important role in the initiation of puberty and reproductive maturity.