ATF6 knockdown decreases apoptosis, arrests the S phase of the cell cycle, and increases steroid hormone production in mouse granulosa cells

J of Cellular Biochemistry

Lang

et al. 2018

MicroRNA‐205 (miR‐205) is involved in various physiological and pathological processes, but its biological function in follicular atresia remains unclear. In this study, we investigated miR‐205 expression in mouse granulosa cells (mGCs) and analyzed its functions in primary mGCs by performing a series of in vitro experiments. Quantitative real‐time polymerase chain reaction showed that miR‐205 expression was significantly higher in early atretic follicles and progressively atretic follicles than in healthy follicles. miR‐205 overexpression in mGCs significantly promoted apoptosis and caspase‐3/9 activities, as well as inhibited estrogen (E2) release and cytochrome P450 family 19 subfamily A polypeptide 1 (CYP19A1, a key gene in E2 production) expression. Bioinformatics and luciferase reporter assays revealed that the gene encoding cyclic AMP response element (CRE)‐binding protein 1 (CREB1) was a direct target of miR‐205 in mGCs. CREB1 upregulation partially rescued the effects of miR‐205 on apoptosis, caspase‐3/9 activities, E2 production, and CYP19A1 expression on mGCs. These results indicate that miR‐205 might play an important role in ovarian follicular development and provide new insights into follicular atresia

Section: Mir-205 Suppressed E2 Synthesis In Mgcsmentioning

confidence: 99%

RETRACTED: MicroRNA‐205 affects mouse granulosa cell apoptosis and estradiol synthesis by targeting CREB1

Zhang

J of Cellular Biochemistry

Lang

et al. 2018

“…In addition, our previous work also revealed that ER stress regulated follicle atresia in mice and goats. Some important proteins in the ER stress, such as lumen and ATF6 [27,28], also have a role in the physiological function of granulosa cells. For XBP1, we just know its expression in the GCs of growing follicles according to the research of Miyuki et al [29].…”

Section: Introductionmentioning

confidence: 99%

Knockdown of XBP1 by RNAi in Mouse Granulosa Cells Promotes Apoptosis, Inhibits Cell Cycle, and Decreases Estradiol Synthesis

Zhao

Lin

et al. 2017

IJMS

Self Cite

Granulosa cells are crucial for follicular growth, development, and follicular atresia. X-box binding protein 1 (XBP1), a basic region-leucine zipper protein, is widely involved in cell differentiation, proliferation, apoptosis, cellular stress response, and other signaling pathways. In this study, RNA interference, flow cytometry, western blot, real-time PCR, Cell Counting Kit (CCK8), and ELISA were used to investigate the effect of XBP1 on steroidogenesis, apoptosis, cell cycle, and proliferation of mouse granulosa cells. ELISA analysis showed that XBP1 depletion significantly decreased the concentrations of estradiol (E2). Additionally, the expression of estrogen synthesis enzyme Cyp19a1 was sharply downregulated. Moreover, flow cytometry showed that knockdown of XBP1 increased the apoptosis rate and arrests the cell cycle in S-phase in granulosa cells (GCs). Further study confirmed these results. The expression of CCAAT-enhancer-binding protein homologous protein (CHOP), cysteinyl aspartate specific proteases-3 (caspase-3), cleaved caspase-3, and Cyclin E was upregulated, while that of Bcl-2, Cyclin A1, and Cyclin B1 was downregulated. Simultaneously, CCK8 analysis indicated that XBP1 disruption inhibited cell proliferation. In addition, XBP1 knockdown also alters the expression of Has2 and Ptgs2, two essential genes for folliculogenesis. Collectively, these data reveal a novel critical role of XBP1 in folliculogenesis by regulating the cell cycle, apoptosis, and steroid synthesis of mouse granulosa cells.

“…CYP19A1, a key enzyme in E2 synthesis, was reportedly to play a key role in during atresia follicles (14,21) Thus, we detected CYP19A1 expression on mRNA and protein levels in mGCs transfected with miR-205 mimics by qRT-PCR and western blot, respectively. Our results showed that overexpression of miR-205 significantly decreased the mRNA ( These results implied that miR-205 can regulate E2 synthesis in mGCs by regulating CYP19A1 expression, leading to mGC apoptosis and follicular atresia.…”

Section: Mir-205 Suppresses E2 Synthesis In Mgcsmentioning

confidence: 89%

MicroRNA-205 affects mouse granulosa cell apoptosis and estradiol synthesis by targeting CREB1

Zhang

Lang

et al. 2018

Preprint

MicroRNAs -205 (miR-205), were reportedly to be involved in various physiological and pathological processes, but its biological function in follicular atresia remain unknown. In this study, we investigated the expression of miR-205 in mouse granulosa cells (mGCs), and explored its functions in primary mGCs using a serial of in vitro experiments. The result of qRT-PCR demonstrated that miR-205 expression was significantly increased in early atretic follicles (EAF), and progressively atretic follicles (PAF) compared to healthy follicles (HF). Our results also revealed that overexpression of miR-205 in mGCs significantly promoted apoptosis, caspas-3/9 activities, and inhibited estrogen E2 release, and cytochrome P450 family 19 subfamily A polypeptide 1 (CYP19A1, a key gene in E2 production) expression.Bioinformatics and luciferase reporter assays revealed that the gene of cyclic AMP 2 response element (CRE)-binding protein 1 (CREB1) was a potential target of miR-205. qRT-PCR and western blot assays revealed that overexpression of miR-205 inhibited the expression of CREB1 in mGCs. Importantly, CREB1 upregulation partially rescued the effects of miR-205 on apoptosis, caspase-3/9 activities, E2 production and CYP19A1 expression in mGCs. Our results indicate that miR-205 may play an important role in ovarian follicular development and provide new insights into follicular atresia.