RESUMO
<p><b>Objective</b>To study the expression of CLAUDIN-11 in the testis tissue of non-obstructive azoospermia (NOA) patients with different severities and investigate its clinical significance.</p><p><b>METHODS</b>Sixty-two NOA patients were divided into a hypospermatogenesis (HS) group (n = 30) and a Sertoli cell only syndrome (SCO) group (n =32). The expression of CLAUDIN-11 in the testicular tissue of the patients was detected by immunohistochemistry, that of CLAUDIN-11 mRNA determined by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), and the levels of serum reproductive hormones measured by chemiluminescent immunoassay.</p><p><b>RESULTS</b>Immunohistochemistry showed that the expression of CLAUDIN-11 was mainly in the cytoplasm of the Sertoli cells around the seminiferous tubule wall in the HS group, but diffusely distributed in the membrane of the Sertoli cells in the SCO group. RT-qPCR revealed a significantly lower expression of CLAUDIN-11 mRNA in the HS than in the SCO group (0.008 ± 0.001 vs 0.013 ± 0.002, t = 10.616, P<0.01). The level of serum luteotropic hormone (LH) was also markedly lower in the HS than in the SCO group (［3.62 ± 1.34］ vs ［4.96 ± 3.10］ IU/L, P<0.05) and so was that of follicle-stimulating hormone (FSH) (［5.36 ± 2.80］ vs ［10.65 ± 9.18］ IU/L, P<0.05).</p><p><b>CONCLUSIONS</b>The up-regulated expression of CLAUDIN-11 in Sertoli cells may play an important role in the development and progression of spermatogenic dysfunction in NOA patients.</p>