Huang Zeng-Hui, Huang Chuan, Ji Xi-Ren, Zhou Wen-Jun, Luo Xue-Feng, Liu Qian, Tang Yu-Lin, Gong Fei, Zhu Wen-Bing
Institute of Reproductive and Stem Cell Engineering, Central South University, Changsha 410008, Hunan Province, China.
Department of Sperm Bank, Reproductive and Genetic Hospital of CITIC-Xiangya, Changsha 410008, Hunan Province, China.
World J Stem Cells. 2021 Nov 26;13(11):1797-1812. doi: 10.4252/wjsc.v13.i11.1797.
Human spermatogonial stem cells (SSCs) are the basis of spermatogenesis. However, little is known about the developmental regulatory mechanisms of SSC due to sample origin and species differences.
To investigates the mechanisms involved in the proliferation of human SSC.
The expression of mitogen-activated protein kinase kinase 7 (MKK7) in human testis was identified using immunohistochemistry and western blotting (WB). MKK7 was knocked down using small interfering RNA, and cell proliferation and apoptosis were detected by WB, EdU, cell counting kit-8 and fluorescence-activated cell sorting. After bioinformatic analysis, the interaction of MKK7 with c-Jun N-terminal kinases ( JNKs ) was verified by protein co-immunoprecipitation and WB. The phosphorylation of JNKs was inhibited by SP600125, and the phenotypic changes were detected by WB, cell counting kit-8 and fluorescence-activated cell sorting.
MKK7 is mainly expressed in human SSCs, and MKK7 knockdown inhibits SSC proliferation and promotes their apoptosis. MKK7 mediated the phosphorylation of JNKs, and after inhibiting the phosphorylation of JNKs, the phenotypic changes of the cells were similar to those after MKK7 downregulation. The expression of MKK7 was significantly downregulated in patients with abnormal spermatogenesis, suggesting that abnormal MKK7 may be associated with spermatogenesis impairment.
MKK7 regulates the proliferation and apoptosis of human SSC by mediating the phosphorylation of JNKs.
人类精原干细胞（SSCs）是精子发生的基础。然而，由于样本来源和物种差异，关于SSCs的发育调控机制知之甚少。
探讨人类SSCs增殖的相关机制。
采用免疫组织化学和蛋白质印迹法（WB）检测丝裂原活化蛋白激酶激酶7（MKK7）在人类睾丸中的表达。使用小干扰RNA敲低MKK7，通过WB、EdU、细胞计数试剂盒-8和荧光激活细胞分选检测细胞增殖和凋亡。经过生物信息学分析后，通过蛋白质免疫共沉淀和WB验证MKK7与c-Jun氨基末端激酶（JNKs）的相互作用。用SP600125抑制JNKs的磷酸化，通过WB、细胞计数试剂盒-8和荧光激活细胞分选检测表型变化。
MKK7主要在人类SSCs中表达，敲低MKK7可抑制SSCs增殖并促进其凋亡。MKK7介导JNKs的磷酸化，抑制JNKs的磷酸化后，细胞的表型变化与MKK7下调后的相似。在精子发生异常的患者中，MKK7的表达明显下调，提示MKK7异常可能与精子发生受损有关。
MKK7通过介导JNKs的磷酸化来调节人类SSCs的增殖和凋亡。
