Loss of occludin expression and impairment of blood testis barrier permeability in rats with autoimmune orchitis: effects of interleukin 6 on Sertoli cells tight junctions

PEREZ, C.V.; SOBARZO, C.; JACOBO, P.V.; PELLIZZARI, E:H:; CIGORRAGA S.B.; DENDUCHIS, B; LUSTIG, L.

BIOLOGY OF REPRODUCTION

SOC STUDY REPRODUCTION

Lugar: Madison; Año: 2012 vol. 87 p. 1 - 12

0006-3363

Inflammation of the male reproductive tract is accepted as being an important etiological factor of infertility. Experimental autoimmune orchitis (EAO) is characterized by interstitial lymphomononuclear cell infiltration and severe damage of seminiferous tubules (STs) with germ cells (GCs) that undergo apoptosis and sloughing. Since blood-testis barrier (BTB) is relevant for the protection of haploid GCs against immune attack the aim of this study was to analyze BTB permeability and the expression of tight junction (TJ) proteins [occludin, claudin 11 and tight junction protein 1 (TJP1)] rats during development of autoimmune orchitis. The role of IL6 as modulator of TJ dynamics was also evaluated, since intratesticular content of this cytokine is increased in EAO rats. Orchitis was induced in Sprague–Dawley adult rats by active immunization with testicular homogenate and adjuvants. Control rats (C) were injected with saline solution and adjuvants. Untreated (N) rats were also studied. Concomitant with early signs of GC sloughing, a reduced expression of occludin and delocalization of claudin 11 and TJP1 were detected in the testis of rats with EAO compared to C and N groups. The use of tracers showed increased BTB permeability in EAO rats. Intratesticular injection of IL6 induced focal testicular inflammation, associated with damaged STs. Rat Sertoli cells cultured in the presence of IL6 exhibited a redistribution of TJ proteins and reduced transepithelial electrical resistance. In conclusion, IL6 might be involved in the downregulation of occludin expression and in the modulation of BTB permeability that occur in rats undergoing autoimmune orchitis.