大鼠睾丸生殖细胞和支持细胞在体外释放不同类型的生物活性转化生长因子β。

Rat testicular germ cells and Sertoli cells release different types of bioactive transforming growth factor beta in vitro.

作者信息

Haagmans Bart L, Hoogerbrugge Jos W, Themmen Axel P N, Teerds Katja J

机构信息

Department of Biochemistry and Cell Biology Faculty of Veterinary Medicine, Utrecht University, POBox 80,176, 3508 TD Utrecht, The Netherlands.

出版信息

Reprod Biol Endocrinol. 2003 Feb 5;1:3. doi: 10.1186/1477-7827-1-3.

DOI:10.1186/1477-7827-1-3

PMID:12646048

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC151560/

Abstract

Several in vivo studies have reported the presence of immunoreactive transforming growth factor-beta's (TGF-beta's) in testicular cells at defined stages of their differentiation. The most pronounced changes in TGF-beta1 and TGF-beta2 immunoreactivity occurred during spermatogenesis. In the present study we have investigated whether germ cells and Sertoli cells are able to secrete bioactive TGF-beta's in vitro, using the CCl64 mink lung epithelial cell line as bioassay for the measurement of TGF-beta. In cellular lysates, TGF-beta bioactivity was only observed following heat-treatment, indicating that within these cells TGF-beta is present in a latent form. To our surprise, active TGF-beta could be detected in the culture supernatant of germ cells and Sertoli cells without prior heat-treatment. This suggests that these cells not only produce and release TGF-beta in a latent form, but that they also release a factor which can convert latent TGF-beta into its active form. Following heat-activation of these culture supernatant's, total TGF-beta bioactivity increased 6- to 9-fold. Spermatocytes are the cell type that releases most bioactive TGF-beta during a 24 h culture period, although round and elongated spermatids and Sertoli cells also secrete significant amounts of TGF-beta. The biological activity of TGF-beta could be inhibited by neutralizing antibodies against TGF-beta1 (spermatocytes and round spermatids) and TGF-beta2 (round and elongating spermatids). TGF-beta activity in the Sertoli cell culture supernatant was inhibited slightly by either the TGF-beta1 and TGF-beta2 neutralizing antibody. These in vitro data suggest that germ cells and Sertoli cells release latent TGF-beta's. Following secretion, the TGF-beta's are converted to a biological active form that can interact with specific TGF-beta receptors. These results strengthen the hypothesis that TGF-beta's may play a physiological role in germ cell proliferation/differentiation and Sertoli cell function.

摘要

多项体内研究报告称，在睾丸细胞分化的特定阶段存在免疫反应性转化生长因子-β（TGF-β）。TGF-β1和TGF-β2免疫反应性最显著的变化发生在精子发生过程中。在本研究中，我们使用CCl64貂肺上皮细胞系作为测量TGF-β的生物测定法，研究了生殖细胞和支持细胞在体外是否能够分泌生物活性TGF-β。在细胞裂解物中，仅在热处理后观察到TGF-β生物活性，这表明在这些细胞中TGF-β以潜伏形式存在。令我们惊讶的是，在未经预先热处理的生殖细胞和支持细胞的培养上清液中可以检测到活性TGF-β。这表明这些细胞不仅以潜伏形式产生和释放TGF-β，而且还释放一种可以将潜伏TGF-β转化为其活性形式的因子。这些培养上清液经热激活后，总TGF-β生物活性增加了6至9倍。精母细胞是在24小时培养期内释放最多生物活性TGF-β的细胞类型，尽管圆形和长形精子细胞以及支持细胞也分泌大量TGF-β。TGF-β的生物活性可以被针对TGF-β1（精母细胞和圆形精子细胞）和TGF-β2（圆形和伸长精子细胞）的中和抗体抑制。支持细胞培养上清液中的TGF-β活性被TGF-β1和TGF-β2中和抗体轻微抑制。这些体外数据表明生殖细胞和支持细胞释放潜伏的TGF-β。分泌后，TGF-β转化为可与特定TGF-β受体相互作用的生物活性形式。这些结果强化了TGF-β可能在生殖细胞增殖/分化和支持细胞功能中发挥生理作用的假说。