title: Cytokines and junction restructuring during spermatogenesis--a lesson to learn from the testis.
abstract: In the mammalian testis, preleptotene and leptotene spermatocytes residing in the basal compartment of the seminiferous epithelium must traverse the blood-testis barrier (BTB) at late stage VIII through early stage IX of the epithelial cycle during spermatogenesis, entering the adluminal compartment for further development. However, until recently the regulatory mechanisms that regulate BTB dynamics remained largely unknown. We provide a critical review regarding the significance of cytokines in regulating the 'opening' and 'closing' of the BTB. We also discuss how cytokines may be working in concert with adaptors that selectively govern the downstream signaling pathways. This process, in turn, regulates the dynamics of either Sertoli-Sertoli tight junction (TJ), Sertoli-germ cell adherens junction (AJ), or both junction types in the epithelium, thereby permitting TJ opening without compromising AJs, and vice versa. We also discuss how adaptors alter their protein-protein association with the integral membrane proteins at the cell-cell interface via changes in their phosphorylation status, thereby altering adhesion function at AJ. These findings illustrate that the testis is a novel in vivo model to study the biology of junction restructuring. Furthermore, a molecular model is presented regarding how cytokines selectively regulate TJ/AJ restructuring in the epithelium during spermatogenesis.
authors: Population Council, Center for Biomedical Research, New York, NY 10021, USA.
authors: Weiliang
authors: W
authors: Xia
authors: Dolores D
authors: DD
authors: Mruk
authors: Will M
authors: WM
authors: Lee
authors: C Yan
authors: CY
authors: Cheng
mesh_terms: D001814:Blood-Testis Barrier; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D008297:Male; D015398:Signal Transduction; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism*; D019108:Tight Junctions / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000502:physiology; D053782:Transforming Growth Factor beta3
chemical_list: D016207:Cytokines; D016212:Transforming Growth Factor beta; D053782:Transforming Growth Factor beta3