Distribution of intracellular and extracellular expression of transforming growth factor-beta1 (TGF-beta1) in human testis and their association with spermatogenesis.

AIM: Spermatogenic dysfunction may result from thickening of seminiferous tubular basement membrane (BM) with tubular sclerosis. Transforming growth factor beta1 (TGF-beta1) plays an important role in fibrogenesis. The intracellular and extracellular expression of TGF-beta1 in the testis were immunohistochemically determined, using LC antibody (LC) for intracellular TGF-beta1 and CC antibody (CC) for extracellular TGF-beta1.

METHODS

Twenty-three testicular biopsy specimens were obtained from varicocele and five from Sertoli-cell-only (SCO) patients, and five from normal volunteers. The relative area involved by the expression of TGF-beta1 for CC or LC (TGF-beta1 index for CC or LC) was examined, and semen parameters and serum hormonal levels and TGF-beta1 were analyzed. The Johnson score (JS), the BM thickness, and the tubular diameter were also determined.

RESULTS

Immunoreactivity for CC was hardly detected. That for LC was detected in the Sertoli and germ cells. The TGF-beta1 index for LC was significantly higher in the varicoceles than in the normal testes. Interestingly, that for LC was significantly higher in the varicoceles than in the SCO. The level of serum TGF-beta1 was significantly higher in varicoceles than in the normal testes.

CONCLUSION

The distribution of the intracellular and extracellular expression of TGF-beta1 in human testis was demonstrated. It suggests that TGF-beta1 is related to fibrosis of seminiferous tubules and may lead to spermatogenic disruption.