Institute of Animal Physiology and Genetics, Czech Academy of Sciences, 27721 Libechov, Czech Republic.
Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpelier 1, 00133 Rome, Italy.
Int J Mol Sci. 2021 Dec 21;23(1):54. doi: 10.3390/ijms23010054.
The extracellular matrix (ECM) is an essential structure with biological activities. It has been shown that the ECM influences gene expression via cytoskeletal components and the gene expression is dependent upon cell interactions with molecules and hormones. The development of ovarian follicles is a hormone dependent process. The surge in the luteinizing hormone triggers ovulatory changes in oocyte microenvironment. In this review, we discuss how proteolytic cleavage affects formation of cumulus ECM following hormonal stimulation; in particular, how the specific proteasome inhibitor MG132 affects gonadotropin-induced cytoskeletal structure, the organization of cumulus ECM, steroidogenesis, and nuclear maturation. We found that after the inhibition of proteolytic cleavage, gonadotropin-stimulated oocyte-cumulus complexes (OCCs) were without any signs of cumulus expansion; they remained compact with preserved cytoskeletal F-actin-rich transzonal projections through the oocyte investments. Concomitantly, a significant decrease was detected in progesterone secretion and in the expression of gonadotropin-stimulated cumulus expansion-related transcripts, such as and . In agreement, the covalent binding between hyaluronan and the heavy chains of serum-derived the inter-alpha-trypsin inhibitor, essential for the organization of cumulus ECM, was missing.
细胞外基质（ECM）是一种具有生物活性的重要结构。已经表明，ECM 通过细胞骨架成分影响基因表达，并且基因表达依赖于细胞与分子和激素的相互作用。卵巢卵泡的发育是一个依赖于激素的过程。黄体生成素的激增触发卵母细胞微环境的排卵变化。在这篇综述中，我们讨论了蛋白水解切割如何影响激素刺激后卵丘 ECM 的形成；特别是，特定的蛋白酶体抑制剂 MG132 如何影响促性腺激素诱导的细胞骨架结构、卵丘 ECM 的组织、类固醇生成和核成熟。我们发现，在抑制蛋白水解切割后，促性腺激素刺激的卵母细胞-卵丘复合物（OCC）没有任何卵丘扩张的迹象；它们仍然紧密，卵母细胞周围的细胞骨架 F-肌动蛋白丰富的跨带投射保持不变。同时，孕激素分泌和促性腺激素刺激的卵丘扩张相关转录物的表达显著下降，如 和 。同样，透明质酸与血清衍生的抗胰蛋白酶抑制剂重链之间的共价结合对于卵丘 ECM 的组织是必不可少的，这种结合缺失了。
