Semaphorin 4C regulates ovarian steroidogenesis through RHOA/ROCK1-mediated actin cytoskeleton rearrangement

Granulosa Cell-Layer Stiffening Prevents Escape of Mural Granulosa Cells from the Post-Ovulatory Follicle

Ovulation is vital for successful reproduction. Following ovulation, cumulus cells and oocyte are released, while mural granulosa cells (mGCs) remain sequestered within the post-ovulatory follicle to form the corpus luteum. However, the mechanism underlying the confinement of mGCs has been a longstanding mystery. Here, in vitro and in vivo evidence is provided demonstrating that the stiffening of mGC-layer serves as an evolutionarily conserved mechanism that prevents mGCs from escaping the post-ovulatory follicles. The results from spatial transcriptome analysis and experiments reveal that focal adhesion assembly, triggered by the LH (hCG)-cAMP-PKA-CREB signaling cascade, is necessary for mGC-layer stiffening. Disrupting focal adhesion assembly through RNA interference results in stiffening failure, mGC escape, and the subsequent development of an abnormal corpus luteum characterized by decreased cell density or cavities. These findings introduce a novel concept of "mGC-layer stiffening", shedding light on the mechanism that prevents mGC escape from the post-ovulatory follicle.

FOXL2 regulates RhoA expression to change actin cytoskeleton rearrangement in granulosa cells of chicken pre-ovulatory follicles†

Forkhead box L2 (FOXL2) is an indispensable key regulator of female follicular development, and it plays important roles in the morphogenesis, proliferation, and differentiation of follicle granulosa cells, such as establishing normal estradiol signaling and regulating steroid hormone synthesis. Nevertheless, the effects of FOXL2 on granulosa cell morphology and the underlying mechanism remain unknown. Using FOXL2 ChIP-seq analysis, we found that FOXL2 target genes were significantly enriched in the actin cytoskeleton-related pathways. We confirmed that FOXL2 inhibited the expression of RhoA, a key gene for actin cytoskeleton rearrangement, by binding to TCATCCATCTCT in RhoA promoter region. In addition, FOXL2 overexpression in granulosa cells induced the depolymerization of F-actin and disordered the actin filaments, resulting in a slowdown in the expansion of granulosa cells, while FOXL2 silencing inhibited F-actin depolymerization and stabilized the actin filaments, thereby accelerating granulosa cell expansion. RhoA/ROCK pathway inhibitor Y-27632 exhibited similar effects to FOXL2 overexpression, even reversed the actin polymerization in FOXL2 silencing granulosa cells. This study revealed for the first time that FOXL2 regulated granulosa cell actin cytoskeleton by RhoA/ROCK pathway, thus affecting granulosa cell expansion. Our findings provide new insights for constructing the regulatory network of FOXL2 and propose a potential mechanism for facilitating rapid follicle expansion, thereby laying a foundation for further understanding follicular development.

miR-129-2-3p binds SEMA4C to regulate HCC development and inhibit the EMT

BACKGROUND

Among primary liver cancers, HCC is the most prevalent. Small noncoding RNAs called miRNAs control the expression of downstream target genes to take part in a variety of physiological and pathological processes, including those related to cancer.

METHODS

miR-129-2-3p and SEMA4C expression levels were assessed using RT-qPCR. The CCK-8, invasion, and wound healing assays were used to confirm the capacity of HCC cells for proliferation, invasion and migration respectively. Serum SEMA4C levels were detected via ELISA. The RIP and dual-luciferase reporter assays were used to confirm the existence of intergenic binding sites. Cell apoptosis assay and cell cycle assay were performed to detect the apoptosis rate and cycle distribution of cells, and WB was performed to detect the protein expression of SEMA4C, RhoA, ROCK1, E-cadherin, N-cadherin, and vimentin. Furthermore, cancer-inhibiting role of miR-129-2-3p were further confirmed by animal tests.

RESULTS

miR-129-2-3p expression was reduced in HCC tissues and cells. Overexpression of miR-129-2-3p decreased the proliferation, invasion, migration, and EMT in HCC cells, whereas inhibition of miR-129-2-3p had the opposite effects. Our research also showed that SEMA4C was increased in HCC tissues, serum and cells, and that SEMA4C knockdown prevented HCC cell invasion, migration, proliferation, and EMT. Overexpression of SEMA4C reversed the inhibitory effect of miR-129-2-3p on HCC.

CONCLUSIONS

Overall, we discovered that through binding to SEMA4C, miR-129-2-3p regulates HCC cell proliferation, invasion, migration, and EMT.

Jiawei Buzhong Yiqi decoction ameliorates polycystic ovary syndrome via oocyte-granulosa cell communication

ETHNOPHARMACOLOGICAL RELEVANCE

Jiawei Buzhong Yiqi Decoction (JWBZYQ), from records of FuqingzhuNvke, is a classical formula for treating obese women related infertility. JWBZYQ has been shown to be effective in treating polycystic ovary syndrome (PCOS) in both clinical studies and practical practice, with the pharmacological mechanism remaining unknown.

AIM OF THE STUDY

To explore the potential therapeutic effects and mechanistic insights of JWBZYQ in PCOS.

MATERIALS AND METHODS

An overweight PCOS rat model was established via testosterone propionate (TP) injection and 45% high-fat diet (HFD). Then they were categorized into five distinct groups: Control group, Model group, low-dose of JWBZYQ (JWBZYQ1) group, high-dose of JWBZYQ (JWBZYQ2) group, and metformin (Met) group. Body weight, estrous cycle, and sex hormone levels were observed. Hematoxylin-Eosin staining was employed to investigate the histological characteristics of the ovaries. To identify the pathways that changed significantly, transcriptome analysis was performed. The protein and mRNA levels of key molecules in ovarian zona pellucida (ZP) organization, transzonal projections (TZPs) assembly, steroid hormone receptors, and steroidogenesis were assessed using phalloidin staining, immunohistochemistry, Western blot, and polymerase chain reaction.

RESULTS

RNA-seq analysis demonstrated that regulation of hormone secretion, cilium assembly, cell projection assembly, and ZP production may all have crucial impact on the etiology of PCOS and therapeutic effect of JWBZYQ. In particular, PCOS rats exhibited elevated expressions of ZP1-3, which can be reversed by JWBZYQ2 particularly. Simultaneously, TZPs assembly was totally disrupted in PCOS rats, evidenced by the phalloidin staining, upregulated calcium-/calmodulin-dependent protein kinase II beta (CaMKIIβ), and deficient p-CaMKIIβ, myosin X (MYO10), proline-rich tyrosine kinase 2 (PTK2), and Fascin. Nonetheless, JWBZYQ or metformin treatment revived the disturbance, repairing the oocyte-granulosa cell communication, regulating steroidogenesis in PCOS rats. In this way, JWBZYQ and metformin exerted remarkable effects in alleviating altered ovarian morphology and function in PCOS rats, with JWBZYQ2 revealing the best effect.

CONCLUSIONS

JWBZYQ restored the altered ovarian morphology and function by regulating the oocyte-granulosa cell communication, which was related with ZP organization and TZPs assembly in the ovary.

Dynamic regulation of semaphorin 7A and adhesion receptors in ovarian follicle remodeling and ovulation

The ovarian follicle is a complex structure that protects and helps in the maturation of the oocyte, and then releases it through the controlled molecular and structural remodeling process of ovulation. The progesterone receptor (PGR) has been shown to be essential in regulating ovulation-related gene expression changes. In this study, we found disrupted expression of the cellular adhesion receptor gene Sema7A in the granulosa cells of PGR-/- mice during ovulation. We subsequently found that expression of Sema7A in preovulatory follicles is promoted by gonadotropins and hypoxia, establishing an asymmetrical pattern with the SEMA7A protein enriched at the apex of large antral follicles. Sema7A expression was downregulated through a PGR-dependent mechanism in the periovulatory period, the abundance of SEMA7A protein was reduced, and the asymmetric pattern became more homogeneous after an ovulatory stimulus. Receptors for Sema7A can either repel or promote intercellular adhesion. During ovulation, striking inverse regulation of repulsive Plxnc1 and adhesive Itga5/Itgb1 receptors likely contributes to dramatic tissue remodeling. The adhesive receptor Itga5 was significantly increased in periovulatory granulosa cells and cumulus-oocyte complexes (COCs), and functional assays showed that periovulatory granulosa cells and COCs acquire increased adhesive phenotypes, while Sema7A repels granulosa cell contact. These findings suggest that the regulation of Sema7A and its associated receptors, along with the modulation of integrin α5, may be critical in establishing the multilaminar ovarian follicle structure and facilitating the remodeling and apical release of the cumulus-oocyte complex during ovulation.