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Abstract

Is cadmium chloride-induced inter-Sertoli tight junction permeability barrier disruption a suitable in vitro model to study the events of junction disassembly during spermatogenesis in the rat testis? 
Chung,Nancy P.Y.; Cheng,Chuen-yan
Endocrinology 142(5): 1878-1888
Publication date: 2001


The events of germ cell movement during spermatogenesis arecomposed of intermittent phases of junction disassembly andreassembly. Although primary Sertoli cells cultured in vitrocan be used to study junction reassembly, an in vitro modelto study the events of junction disassembly is still lacking.We have assessed whether the CdCl-induced inter-Sertoli tightjunction (TJ) permeability barrier disruption in vitro can fillthis gap. When Sertoli cells (1.2 x 10 cells/cm) were culturedon Matrigel-coated bicameral units to allow the assembly ofinter-Sertoli TJs, it was manifested by a steady rise in transepithelialelectrical resistance across the Sertoli cell epithelia. Exposureof these cells on day 1 (i.e. 24 h after their isolation) toCdCl at 5-10 µM for 8 h could perturb the inter-SertoliTJ assembly dose dependently without any apparent cytotoxicity.Likewise, when cells were exposed to CdCl (0.1-5 µM) onday 4 for 8 h after inter-Sertoli TJs were already assembled, CdClalso perturbed the maintenance of inter-Sertoli TJ permeabilitybarrier dose dependently without signs of cell cytotoxicity.Although the perturbed inter-Sertoli TJs were not capable ofresealing even after the removal of CdCl, the presence of testosterone(T) at 1 x 10 M allowed resealing of the inter-Sertoli TJbarrier after CdCl was removed, whereas the presence of 2 x 10M testosterone even protected Sertoli cells from CdCl-induceddamage. More important, the reassembly of inter-Sertoli TJsafter CdCl-induced TJ disruption was accompanied by changesin cellular gene expression of occludin and urokinase plasminogenactivator, which mimicked their patterns during inter- SertoliTJ assembly in vitro without CdCl treatment. Based on theseresults, it is apparent that CdCl-induced inter-Sertoli TJdisassembly is a potential in vitro model to study the eventsof junction disassembly.