Biomedical Center Munich (BMC), Cell Biology, Anatomy III, Ludwig-Maximilians-Universität München, 82152, Planegg-Martinsried, Germany.
Department of Chemosensation, Institute for Biology II, RWTH Aachen University, 52074, Aachen, Germany.
Sci Rep. 2018 Jan 23;8(1):1431. doi: 10.1038/s41598-018-19624-3.
Peritubular myoid cells, which form the walls of seminiferous tubules in the testis, are functionally unexplored. While they transport sperm and contribute to the spermatogonial stem cell niche, specifically their emerging role in the immune surveillance of the testis and in male infertility remains to be studied. Recently, cytokine production and activation of Toll-like receptors (TLRs) were uncovered in cultured peritubular cells. We now show that human peritubular cells express purinergic receptors P2RX4 and P2RX7, which are functionally linked to TLRs, with P2RX4 being the prevalent ATP-gated ion channel. Subsequent ATP treatment of cultured peritubular cells resulted in up-regulated (pro-)inflammatory cytokine expression and secretion, while characteristic peritubular proteins, that is smooth muscle cell markers and extracellular matrix molecules, decreased. These findings indicate that extracellular ATP may act as danger molecule on peritubular cells, able to promote inflammatory responses in the testicular environment.
睾丸曲细精管的壁细胞(peritubular myoid cells),形成于睾丸中的生精小管,其功能尚未被探索。尽管它们可以运输精子并有助于精原干细胞龛,但它们在睾丸免疫监视和男性不育中的新兴作用仍有待研究。最近,在培养的曲细精管壁细胞中发现了细胞因子的产生和 Toll 样受体(TLRs)的激活。我们现在表明,人曲细精管壁细胞表达嘌呤能受体 P2RX4 和 P2RX7,它们与 TLRs 功能相关联,其中 P2RX4 是常见的 ATP 门控离子通道。随后用 ATP 处理培养的曲细精管壁细胞,导致(促)炎细胞因子的表达和分泌上调,而特征性的曲细精管蛋白,即平滑肌细胞标记物和细胞外基质分子,则减少。这些发现表明,细胞外 ATP 可能作为曲细精管细胞的危险分子,能够促进睾丸环境中的炎症反应。