Exposure to nicotine regulates prostaglandin E2 secretion and autophagy of granulosa cells to retard follicular maturation in mammals.

Exposure to nicotine by cigarette smoking have shown strongly defectives on the physiological function of ovaries, which in turn leads to disorders of fertility in women. However, the potential molecular mechanisms remain to be elucidated. In this study, we notably found that nicotine was likely to specifically raise the expression of histone deacetylase 3 (HDAC3) to promote the apoptosis and autophagy of granulosa cells (GCs) and block follicular maturation. Moreover, prostaglandin E2 (PGE2) inhibited the apoptosis of GCs and facilitated follicular maturation, and nicotine appeared to inhibit PGE2 secretion by freezing the expression of cyclooxygenase 1 (COX1), which was the rate-limiting and essential enzyme for PGE2 synthesis. Epigenetically, the nicotine was observed to diminish the histone H3 lysine 9 acetylation (H3K9ac) level and compact the chromatin accessibility in -1776/-1499 bp region of COX1 by evoking the expression of HDAC3, with the deactivated Cas9-HDAC3/sgRNA system. Mechanistically, the COX1 protein was found to pick up and degrade the autophagy related protein beclin 1 (BECN1) to control the autophagy of GCs. These results provided a potential new molecular therapy to recover the damage of female fertility induced by nicotine from cigarette smoking.

Knockdown of DNMT1 Induces SLCO3A1 to Promote Follicular Growth by Enhancing the Proliferation of Granulosa Cells in Mammals.

In female mammals, the proliferation and apoptosis of granulosa cells (GCs) have been shown to determine the fate of follicles. DNA methyltransferases (DNMTs) and SLCO3A1 have been reported to be involved in the survival of GCs and follicular growth. However, the molecular mechanisms enabling DNMTs to regulate the expression of SLCO3A1 to participate in follicular growth are unclear. In this study, we found that the knockdown of DNMT1 enhanced the mRNA and protein levels of SLCO3A1 by regulating the chromatin accessibility probably. Moreover, SLCO3A1 upregulated the mRNA and protein levels of MCL1, PCNA, and STAR to promote the proliferation of GCs and facilitated cell cycle progression by increasing the mRNA and protein levels of CCNE1, CDK2, and CCND1, but it decreased apoptosis by downregulating the mRNA and protein levels of CASP3 and CASP8. Moreover, SLCO3A1 promoted the growth of porcine follicles and development of mice follicles. In conclusion, the knockdown of DNMT1 upregulated the mRNA and protein levels of SLCO3A1, thereby promoting the proliferation of GCs to facilitate the growth and development of ovarian follicles, and these results provide new insights into investigations of female reproductive diseases.

HDAC1-Mediated lncRNA Stimulatory Factor of Follicular Development to Inhibit the Apoptosis of Granulosa Cells and Regulate Sexual Maturity through miR-202-3p-COX1 Axis.

Abnormal sexual maturity exhibits significant detrimental effects on adult health outcomes, and previous studies have indicated that targeting histone acetylation might serve as a potential therapeutic approach to regulate sexual maturity. However, the mechanisms that account for it remain to be further elucidated. Using the mouse model, we showed that Trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, downregulated the protein level of Hdac1 in ovaries to promote the apoptosis of granulosa cells (GCs), and thus arrested follicular development and delayed sexual maturity. Using porcine GCs as a cell model, a novel sexual maturity-associated lncRNA, which was named as the stimulatory factor of follicular development (SFFD), transcribed from mitochondrion and mediated by HDAC1, was identified using RNA sequencing. Mechanistically, HDAC1 knockdown significantly reduced the H3K27ac level at the -953/-661 region of SFFD to epigenetically inhibit its transcription. SFFD knockdown released miR-202-3p to reduce the expression of cyclooxygenase 1 (COX1), an essential rate-limited enzyme involved in prostaglandin synthesis. This reduction inhibited the proliferation and secretion of 17ß-estradiol (E2) while promoting the apoptosis of GCs. Consequently, follicular development was arrested and sexual maturity was delayed. Taken together, HDAC1 knockdown-mediated SFFD downregulation promoted the apoptosis of GCs through the miR-202-3p-COX1 axis and lead to delayed sexual maturity. Our findings reveal a novel regulatory network modulated by HDAC1, and HDAC1-mediated SFFD may be a promising new therapeutic target to treat delayed sexual maturity.

DNMT1-mediated lncRNA IFFD controls the follicular development via targeting GLI1 by sponging miR-370.

DNA methylation and long noncoding RNAs (lncRNAs) exhibit an indispensable role in follicular development. However, the specific mechanisms regarding lncRNAs mediated by DNA methylation in follicular development remain unclearly. In this study, we found that inhibiting the expression of DNMT1 promoted granulosa cells (GCs) apoptosis to inhibit follicular development. A novel follicular development-associated lncRNA named inhibitory factor of follicular development (IFFD) was mediated by DNMT1 and showed to arrest follicular development by inhibiting GCs proliferation and estrogen (E2) secretion but promoting GCs apoptosis. Mechanistically, the deactivated Cas9-TET1 demonstrated that the hypomethylation in -1261/-1254 region of IFFD promoted the transcription of IFFD by recruiting SP1. IFFD induced the expression of GLI family zinc finger 1 through competitive binding miR-370, thereby up-regulating the expression of CASP3 to promote GCs apoptosis, as well as downregulating the expressions of PCNA and CYP19A1 to inhibit GCs proliferation and E2 secretion. Collectively, DNMT1-mediated IFFD might be a novel target for the regulation of follicular development.

A microRNA­125a variant, which affects its mature processing, increases the risk of radiation­induced pneumonitis in patients with non­small­cell lung cancer.

The present study aimed to investigate the role of microRNA (miR)­125a in the development of pneumonitis inpatients with non­small­cell lung cancer that received radiotherapy. In addition, the study aimed to determine how the miR­125a affects its target, transforming growth factor ß (TGFß). Bioinformatics tools were used to identify a potential miR­125a binding site in the 3'untranslated region of TGFß, which was subsequently confirmed using a dual­luciferase reporter system. In addition, tissue samples were collected from patients with lung cancer and genotyped as CC (n=36), CT (n=28) or TT (n=6). The expression levels of miR­125a and TGFß in these samples were determined, and CC genotype samples demonstrated upregulated miR­125a expression, and downregulated TGFß protein and mRNA expression compared with samples carrying the minor allele, T. To further investigate the association between the rs12976445 polymorphism and the risk of pneumonitis in patients with lung cancer that received radiotherapy, 534 lung cancer patients diagnosed with pneumonitis and 489lung cancer patients without pneumonitis were recruited. rs12976445 was shown to be significantly associated with the risk of pneumonitis. In conclusion, the rs12976445 polymorphism increased expression levels of TGFß by decreasing the expression of miR­125a, and therefore may be associated with the development of pneumonitis in patients with lung cancer that receive radiotherapy.