The Function Study Of NXF3and CaMKIV In Spermatogenesis

About10%-15%couples of childbearing in the world are suffering from infertility, male factor infertility accounts for40%of infertile couples, and with the impact of environmental and social factors, the proportion of male infertility is increasing. Most of the infertile man are non-obstructive azoospermia (NOA) remained unexplained and extremely unfavorable for the clinical treatment. With the in-depth study of the non-obstructive azoospermia over the past decades, it’s found that male infertility has relationship with blood-testis barrier dysfunction, however, the molecular mechanism which leads to dysfunction of the blood-testis barrier remains to be elucidated.Blood-testis barrier is constituted by adjacent Sertoli cells in the basal compartment of the seminiferous epithelium through tight junction, provides a stable microenvironment and unique immune barrier for spermatogenesis, and regulates spermatogenesis by "opening" and "closing" orderly. Disruption of the "opening" and "closing" of blood-testis barrier will break the microenvironment and immune barrier, impaire spermatogenesis and lead to male infertility. Many factors take part in the regulation of "opening" and "closing" of blood-testis barrier, and TGF-β3is one of the important factors. It’s important to clarify the expression and secretion of TGF-β3and this is the first research program be choosed.NXF3is one of the nuclear RNA export factor family and its specific expression iwas detected in Sertoli cells of mouse testis, as well as in the principal cells in the segment II of the caput epididymis. The expression of NXF3can be first detected at10dpp, when the mouse blood-testis barrier is constituted, it arouses our great interest that NXF3maybe related to blood-testis barrier. Since TGF-β3is one of the important factors, the expressions of NXF3and TGF-β3were checked and a significant negative correlation was discoverd between the expression levels of TGF-β3and NXF3in the mouse testis. This discovery is confirmed by another experiments, the expression of NXF3was decreased while TGF-β3increased in the CdCl2-or heat-treated testes. With further research, we find that NXF3can affect the expression of TGF-β3through regulating the negative feedback of TGF-β3transcription, that is the activity of Smad2/3passway was promoted by NXF3and then the transcription of TGF-β3was depressed when the TGF-β signal passway activated. The partner of NXF3was found by detailed study, STRAP, an inhibitor of TGF-β signal passway, thus the mechanism of NXF3regulating the expression of TGF-β3could be clarified. That is when TGF-β signal passway activated, NXF3interplays with STRAP and the association of STRAP between Smad7is inhibited, and the protein comlex of TβR1(TD)-STRAP-Smad7is disrupted, so the Smad2/3passway is activated and depressed the transcription of TGF-P3, and also many target genes of the Smad2/3passway are regulated, just as Claudinll, WT1, GATA1and p21.Chromatoid body is a male specific structure and appears as a filamentous and lobulated granule using electron microscopy. Chromatoid body contains many RNA-binding proteins and RNAs and on the basis of its structural features and composition, it is considered as a specialized form of germplasm or nuage. Thus, chromatoid body is proposed as a RNA processing center of male germ cells and regulates gene expression during spermatogenesis, and has attracted the interesting of many researchers. Over one hundred years has passed since chromatoid body was first described in1891, many proteins and RNAs were found located in chromatoid body, but the function and mechanism of chromatoid body is still unclear.Ca2+/Calmodulin-dependent Protein Kinase IV (CaMKIV) localizes in chromatoid body and is a new component of chromatoid body reported by this study. It’s been reported that CaMKIV was expressed in spermatocyte and spermatid in testis and camkiv knockout mice were sterile for the abnormal of histone proteins transition during elongated sperm. Here we report that CaMKIV can associate with chromatoid body components:MVH, MIWI and KIF17b, most importantly that CaMKIV can promote the interplay of KIF17b between MVH and MIWI. For the first time we report the regulation of proteins association in chromatoid body and this will promote the knowledge of structure and function of chromatoid body.