Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
Department of Veterinary Anatomy, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
Development. 2020 Jul 13;147(13):dev185884. doi: 10.1242/dev.185884.
In mammalian testis, contractile peritubular myoid cells (PMCs) regulate the transport of sperm and luminal fluid, while secreting growth factors and extracellular matrix proteins to support the spermatogonial stem cell niche. However, little is known about the role of testicular smooth muscle cells during postnatal testicular development. Here we report age-dependent expression of hypermethylated in cancer 1 (; also known as ) in testicular smooth muscle cells, including PMCs and vascular smooth muscle cells, in the mouse. Postnatal deletion of in smooth muscle cells led to their increased proliferation and resulted in dilatation of seminiferous tubules, with increased numbers of PMCs. These seminiferous tubules contained fewer Sertoli cells and more spermatogonia, and fibronectin was not detected in their basement membrane. The expression levels of genes encoding smooth muscle contractile proteins, and , were downregulated in the smooth muscle cells lacking , and the seminiferous tubules appeared to have reduced contractility. These data imply a role for in determining the size of seminiferous tubules by regulating postnatal smooth muscle cell proliferation, subsequently affecting spermatogenesis in adulthood.
在哺乳动物睾丸中，收缩性的小管周肌样细胞 (PMCs) 调节精子和管腔液的运输，同时分泌生长因子和细胞外基质蛋白，以支持精原干细胞龛。然而，对于睾丸平滑肌细胞在出生后睾丸发育中的作用知之甚少。在这里，我们报告了在小鼠睾丸中，包括 PMCs 和血管平滑肌细胞在内的睾丸平滑肌细胞中高甲基化基因 1 (也称为 ) 的年龄依赖性表达。出生后平滑肌细胞中 的缺失导致其增殖增加，导致精曲小管扩张，PMCs 数量增加。这些精曲小管中 Sertoli 细胞较少，精原细胞较多，其基底膜中未检测到纤维连接蛋白。缺乏 的平滑肌细胞中编码平滑肌收缩蛋白的基因 和 的表达水平下调，并且精曲小管的收缩性似乎降低。这些数据表明 通过调节出生后平滑肌细胞增殖来决定精曲小管的大小，进而影响成年后的精子发生。
