Dynamic cross-talk between cells and the extracellular matrix in the testis
Article first published online: 17 AUG 2004
Copyright © 2004 Wiley Periodicals, Inc.
Volume 26, Issue 9, pages 978–992, September 2004
How to Cite
Siu, M. K.Y. and Cheng, C. Y. (2004), Dynamic cross-talk between cells and the extracellular matrix in the testis. Bioessays, 26: 978–992. doi: 10.1002/bies.20099
- Issue published online: 17 AUG 2004
- Article first published online: 17 AUG 2004
- This work was supported in part by grants from the National Institutes of Health (NICHD, U01 HD45908 to CYC; U54 HD29990, Project 3 to CYC), the CONRAD Program (CICCR CIG 96-05-B and CIG 01-72), and the Noopolis Foundation. MKYS's current address is: Michelle Siu, PhD, Department of Zoology, University of Hong Kong, Hong Kong, China
In the seminiferous tubule of the mammalian testis, one type A1 spermatogonium (diploid, 2n) divides and differentiates into 256 spermatozoa (haploid, n) during spermatogenesis. To complete spermatogenesis and produce ∼150 × 106 spermatozoa each day in a healthy man, germ cells must migrate progressively across the seminiferous epithelium yet remain attach to the nourishing Sertoli cells. This active cell migration process involves precisely controlled restructuring events at the tight (TJ) and anchoring junctions at the cell–cell interface. While the hormonal events that regulate spermatogenesis by follicle-stimulating hormone and testosterone from the pituitary gland and Leydig cells, respectively, are known, less is known about the mechanism(s) that regulates junction restructuring during germ cell movement in the seminiferous epithelium. The relative position of tight (TJs) and anchoring junctions in the testis is of interest. Sertoli cell TJs that constitute the blood–testis barrier (BTB) are present side by side with anchoring junctions and are adjacent to the basement membrane. This intimate physical association with the TJs, the anchoring junctions and the basement membrane (a modified form of extracellular matrix, ECM) suggests a role for the ECM in the junction dynamics of the testis. Indeed, evidence is accumulating that ECM proteins are crucial to Sertoli cell TJ dynamics. In this review, we discuss the pivotal role of tumor necrosis factor α (TNFα) on BTB dynamics via its effects on the homeostasis of ECM proteins. In addition, discussion will also be focused on the novel findings regarding the role of non-basement-membrane-associated ECM proteins and components of focal adhesion (a cell–matrix anchoring junction type) in the regulation of junction dynamics in the testis. BioEssays 26:978–992, 2004. © 2004 Wiley Periodicals, Inc.