|
Asian Journal of Andrology (2012) 14, 884–889; doi:10.1038/aja.2012.71; published online 24 September 2012
Downregulation of cold-inducible RNA-binding protein activates mitogen-activated protein kinases and impairs spermatogenic function in mouse testes
Zhi-Ping Xia1, Xin-Min Zheng1, Hang Zheng1, Xiao-Jun Liu1, Gui-Yong Liu2 and Xing-Huan Wang1
1 Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
2 Department of Urology, Qianjiang Central Hospital, Qianjiang 433100, China
Correspondence: Dr XM Zheng, (drzhengxinmin@sohu.com)
Received 28 March 2012; Revised 1 May 2012; Accepted 5 June 2012
Advance online publication 24 September 2012
| Abstract |
Cold-inducible RNA-binding protein (CIRP) is an RNA-binding protein that is expressed in normal testes and downregulated after heat stress caused by cryptorchidism, varicocele or environmental temperatures. The purpose of this study was to investigate the functions of CIRP in the testes. We employed RNAi technique to knock down the expression of CIRP in the testes, and performed haematoxylin and eosin staining to evaluate morphological changes following knockdown. Germ cell apoptosis was examined by terminal deoxynucleotidal transferase-mediated dUTP nick end labelling (TUNEL) assay, and mitogen-activated protein kinase (MAPK) signalling pathways were investigated by Western blotting to determine the possible mechanism of apoptosis. We found that using siRNA is a feasible and reliable method for knocking down gene expression in the testes. Compared to controls, the mean seminiferous tubule diameter (MSTD) and the thickness of the germ cell layers decreased following siRNA treatment, whereas the percentage of apoptotic seminiferous tubules increased. The p44/p42, p38 and SAPK/JNK MAPK pathways were activated after downregulation of CIRP. In conclusion, we discovered that downregulation of CIRP resulted in increased germ cell apoptosis, possibly via the activation of the p44/p42, p38 and SAPK/JNK MAPK pathways.
Keywords: cold-inducible RNA-binding protein (CIRP); mitogen-activated protein kinase (MAPK); siRNA in vivo; spermatogenesis; heat stress; male infertility |
|
