蛋白激酶B在人睾丸组织中的表达及意义

Expression of protein kinase B in human testis tissues

目的探讨蛋白激酶B（PKB）在人睾丸组织中的表达及意义。方法用免疫组织化学方法检测PKB蛋白在正常睾丸组织中的表达。用荧光定量PCR检测PKBα、PKBβ和PKBγ三种异构体mRNA在正常人、严重少弱精子症和非梗阻性无精子症患者的睾丸组织中的表达水平，并用WesternBlot方法检测各组睾丸组织中PKB蛋白的表达情况。结果PKB在正常人睾丸组织的精原细胞、精母细胞、精子细胞的胞质中表达，而磷酸化的PKB主要在初级精母细胞核中表达，精原细胞和精子细胞核中也可见少量表达。PKBαmRNA在正常人和严重少弱精子症的睾丸组织中表达没有差异，均显著高于非梗阻性无精子症患者差异具统计学意义（P〈0．05）；PKBβ和PKBγmRNA的表达在三组间无差异。WesternBlot结果显示正常人和严重少弱精子症患者的睾丸组织中均可见PKB和磷酸化PKB的表达，且两者的表达在两组间无差异（P〉0．05）；非梗阻性无精子症患者的睾丸组织中PKB和磷酸化PKB未见明显表达。结论PKB的三种异构体mRNA、PKB及磷酸化的PKB蛋白在正常睾丸组织中均有表达，而非梗阻性无精子症患者的睾丸组织中PKB蛋白无明显表达，推测PKB与生精功能可能有密切联系。

Objective To investigate the expression of PKB in testis tissues and its significance in spermatogenesis. Methods The expression of PKB in normal testis tissue was detected by immunohistochemistry. The expressions of PKB α, PKB β and PKB γmRNA were measured by realtime PCR in testis tissues with nonobstructive azoospermia, oligoasthenospermia and normal men, and the levels of PKB protein and its phosphorylated protein were assessed by western blotting Results The expression of PKB mainly distributed at the cytoplasm of germ cells, whereas strong expression of phosphorylated PKB was mainly at the nucleus of primary spcrmatocytes, and a little expression was at the nucleus of spermatids and spermatogonia. There was no difference in the expressions of PKB αmRNA in testicular tissues between normal men and oligoasthenospermia patients, whereas a significant difference between above two groups and non-obstructive azoospermia group （P = 0.025）. The expression levels of PKB βand PKB γrnRzNA were similar among three groups. The expression level of phosphorylated PK.B in testicular tissues had no difference between normal men and oligoasthenospermia patients. No expression was found for PK.B protein and its phosphorylated protein in testis tissue of non-obstructive azoospermia patients. Conclusion Three isoforms of PKB mRNA, PKB and phosphorylatcd PKB were all detected in normal testis tissue. No expression of PKB was found in non-obstructive azoospermia testes which indicated that PKB might be associated with spermatogenesis