Decreased expression of the heat shock protein hsp70-2 is associated with the pathogenesis of male infertility

Objective: To examine the expression of the heat shock protein hsp70-2, and the possible relationship with the pathogenesis of male infertility.

Design: Prospective study.

Setting: Reproductive testing laboratory in a university hospital.

Patient(s): Men undergoing testicular biopsy during an investigation of subfertility.

Intervention(s): Testicular tissues were obtained from biopsies of men undergoing infertility evaluation and subdivided into three groups: normal testes, maturational arrest and Sertoli cell-only syndrome. Immunostaining and Western blotting techniques determined expression of the heat shock protein hsp70-2

Main Outcome Measure(s): Expression of the heat shock protein hsp70-2 in the testes.

Result(s): The experimental data demonstrated that the heat shock protein hsp70-2 was expressed in the normal and maturation arrest testicular specimens. The heat shock protein hsp70-2 was strongly present in the cytoplasm of spermatocytes and spermatides in the adluminal compartment of the seminiferous epithelium in normal testis. However, maturation arrest testis tissue demonstrated light staining in spermatocytes and spermatides, and Sertoli-only specimens demonstrated no staining for the heat shock protein hsp70-2. The Western blotting data showed a 70-kDa heat shock protein in the normal and maturation arrest testicular tissues, but not in the Sertoli-only tissues.

Conclusions: These results suggest that the heat shock protein hsp70-2 is expressed in spermatocytes and spermatides in normal and maturation arrest tissues. However, the expression of the heat shock protein hsp70-2 was low in maturation arrest, and no heat shock protein hsp70-2 was demonstrated in Sertoli-only specimens. Therefore the decreased expression of the heat shock protein hsp70-2 is associated with the pathogenesis of male infertility.