[Relationship of the kallistatin gene expression with male spermatogenic dysfunction and its possible mechanism]

Objective: To explore the role of the kallistatin gene in male spermatogenesis and its possible mechanism, and provide some new ideas for the clinical treatment of spermatogenic dysfunction.

Methods: We collected semen samples from the patients with oligospermia (OS) or non-obstructive azoospermia (NOAS) as well as testis tissue from testicular puncture. We detected the differential expression of kallistatin in the seminal plasma and the mRNA and protein expression levels of kallistatin, KLK1, B2R, Bcl-2, casepase-3, Bax and other molecules in the testis tissue, assessed the testicular spermatogenic function using Johnsen's scores, examined the interstitial fibrosis in the testis by Masson and Sirius staining, and analyzed the correlation of the expression level of kallistatin with spermatogenesis, apoptosis and fibrosis.

Results: Kallistatin was highly expressed in the seminal plasma and testis tissue. The expression of kallistatin was significantly decreased in the seminal plasma (P < 0.05) and so were those of kallistatin, KLK1 and B2R in the testis tissue of the NOAS and OS patients compared with those in the normal controls (P < 0.01), but no statistically significant difference was found between the expression levels of kallistatin and KLK1 within the same group (P > 0.05). The expression of Bcl-2 in the testis tissue was significantly lower (P < 0.01) and those of Bax and Casepase-3 dramatically higher in the OS and NOAS patients than in the normal males (P < 0.01). Cell apoptosis was negatively correlated with the expression of kallistatin. The results of Masson and Sirius staining showed that the fibrosis of the testis tissue and the ratio of type I/III collagen fibers were markedly increased in the OS and NOAS patients in comparison with the normal controls, even more significantly in the NOAS than in the OS group.

Conclusion: Decreased expression of kallistatin may be related to spermatogenic dysfunction, and the kallistatin expression plays a regulatory role in the testicular spermatogenesis, probably by regulating cell apoptosis and fibrosis in the testis tissue, but the specific mechanism needs to be confirmed by further studies.