Cell Res. 316, 2945C2960 [PMC free article] [PubMed] [Google Scholar] 41. during the epithelial cycle, known as the apical ES-BTB-BM axis. However, the precise role of BM in this axis remains unknown. Here, we show that laminin 2 in the BM serves as the crucial regulator in this axis as laminin 2, likely its 80-kDa fragment from the C terminus, was found to be transported across the seminiferous epithelium at stages VIIICIX of the epithelial cycle, from the BM to the luminal edge of the tubule, possibly being used to modulate apical ES restructuring at these stages. Of more importance, a knockdown of laminin 2 in Sertoli cells was shown to induce the Sertoli cell tight junction permeability barrier disruption changes in localization of adhesion proteins at the tight junction and basal ES at the Sertoli cell BTB. These changes were found to be mediated by a disruption of F-actin organization that was induced by changes in the spatiotemporal expression of actin binding/regulatory proteins. Furthermore, laminin 2 knockdown also perturbed microtubule (MT) Aliskiren (CGP 60536) organization by considerable down-regulation of MT polymerization changes in the spatiotemporal expression of EB1 (end-binding protein 1), a +TIP (MT plus-end tracking protein). In short, laminin 2 in the BM seems to play a crucial role in the BTB-BM axis by modulating BTB dynamics during spermatogenesis.Gao, Y., Mruk, D., Chen, H., Lui, W.-Y., Lee, W. M., Cheng, C. Y. Regulation of the bloodCtestis barrier by a local axis in the testis: role of laminin 2 in the basement membrane. mitosis, meiosis, postmeiotic spermatid development, and spermiogenesis, which leads to the release of sperm at spermiation (for reviews, see refs. 1, 2). Of interest, cellular events that take place across the seminiferous epithelium are intriguingly coordinated. For instance, spermiation takes place at the luminal edge near the tubule lumen in the adluminal compartment at stage VIII in rodents late stage II in humans, which coincides with remodeling of the bloodCtestis barrier (BTB) near the basement membrane (BM) to facilitate transport of preleptotene spermatocytes that reside in the basal compartment across the immunological barrier (for reviews, see refs. 3C5). Earlier studies have shown that biologically active fragments, such as F5-peptide (6), that Aliskiren (CGP 60536) are generated at the apical ectoplasmic specialization (ES; an actin-rich, testis-specific anchoring device at the elongated spermatid-Sertoli cell interface) at spermiationlikely the action of matrix metalloprotease-2 (MMP-2) (7) on laminin-3, a apical ES adhesion protein in elongated spermatid cell surface (8, 9)induce BTB remodeling (10). In this context, it is noted that the BTB is composed of an ultrastructure that is similar to that of the apical ES, but is designated basal Sera, which coexists with limited junction (TJ), space junction, and desmosome to constitute the BTB. Sera is definitely typified by the presence of an extensive network of actin microfilament bundles, sandwiched between the cisternae of endoplasmic reticulum and the opposing Sertoli-spermatid (apical Sera) Sertoli-Sertoli (basal Sera) plasma membranes (for evaluations, Rabbit polyclonal to ZNF394 observe refs. 5, 11, 12). These findings (6, 10) illustrate the presence of an autocrine-based practical axis that coordinates cellular events, namely spermiation and BTB redesigning, that take place at reverse ends of the seminiferous epithelium at stage VIII of the epithelial cycle in the rat testis (for a review, observe ref. 13). The concept of this local regulatory axis has been confirmed by additional investigators by using a phthalate-induced Sertoli cell injury model in which phthalate-mediated MMP-2 activation prospects to laminin chain degeneration that also modulates BTB restructuring (14, 15). As BTB is located near the BM, it is likely that there is a local axis in which BM regulates BTB restructuring events to support transport of preleptotene spermatocytes across the barrier during the epithelial cycle. Indeed, a recent report has shown the NC1 website released from your collage 3 (IV) chain in BM modulates BTB restructuring (16), which helps the notion that there is a functional axis between the BTB and the BM. In addition to collagen, laminin 1, Aliskiren (CGP 60536) 2, 4, 1, 2, and 1 are the major laminin chains found in the BM of seminiferous tubules in rodent testes (9, 17). Furthermore, in a study that used a genetic model, it was demonstrated that transgenic mice that were deficient in laminin 2 chain (also known as merosin) led to a disruption of the apical Sera, which caused germ cell exfoliation and male infertility (17), assisting the notion that there is a local Aliskiren (CGP 60536) axis between apical Sera and BM and illustrating the significance of laminin.