Volume 21, Issue 4 (July 2019) 21, 365–374; 10.4103/aja.aja_126_18
Regulation of blood-testis barrier dynamics by the mTORC1/rpS6 signaling complex: An in vitro study
Lin-Xi Li1,2, Si-Wen Wu1,2, Ming Yan2,3, Qing-Quan Lian1, Ren-Shan Ge1, C Yan Cheng1,2
1 The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou 325027, China 2 The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, NY 10065, USA 3 Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009, China
Correspondence: Dr. CY Cheng (y-cheng@popcbr.rockefeller.edu) or Dr. QQ Lian (lianqingquanmz@163.com)
01-Mar-2019
Abstract |
During spermatogenesis, developing germ cells that lack the cellular ultrastructures of filopodia and lamellipodia generally found in migrating cells, such as macrophages and fibroblasts, rely on Sertoli cells to support their transport across the seminiferous epithelium. These include the transport of preleptotene spermatocytes across the blood-testis barrier (BTB), but also the transport of germ cells, in particular developing haploid spermatids, across the seminiferous epithelium, that is to and away from the tubule lumen, depending on the stages of the epithelial cycle. On the other hand, cell junctions at the Sertoli cell–cell and Sertoli–germ cell interface also undergo rapid remodeling, involving disassembly and reassembly of cell junctions, which, in turn, are supported by actin- and microtubule-based cytoskeletal remodeling. Interestingly, the underlying mechanism(s) and the involving biomolecule(s) that regulate or support cytoskeletal remodeling remain largely unknown. Herein, we used an in vitro model of primary Sertoli cell cultures that mimicked the Sertoli BTB in vivo overexpressed with the ribosomal protein S6 (rpS6, the downstream signaling protein of mammalian target of rapamycin complex 1 [mTORC1]) cloned into the mammalian expression vector pCI-neo, namely, quadruple phosphomimetic and constitutively active mutant of rpS6 (pCI-neo/p-rpS6-MT) versus pCI-neo/rpS6-WT (wild-type) and empty vector (pCI-neo/Ctrl) for studies. These findings provide compelling evidence that the mTORC1/rpS6 signal pathway exerted its effects to promote Sertoli cell BTB remodeling. This was mediated through changes in the organization of actin- and microtubule-based cytoskeletons, involving changes in the distribution and/or spatial expression of actin- and microtubule-regulatory proteins.
Keywords: blood-testis barrier; F-actin; microtubule; mTORC1; rpS6; Sertoli cells; testis
Full Text |
PDF |
|
|
Browse: 1361 |
|