ABSTRACT
The apoptosis that occurs in the immature testis under physiological conditions is necessary for male germ cell development, whereas improper activation of apoptosis can impair spermatogenesis and cause defects in reproduction. We previously demonstrated that in mice, the makorin-2 (Mkrn 2) gene is expressed exclusively in the testis and its deletion leads to male infertility. To understand the potential molecular mechanism, in this study, we found that levels of apoptosis in the testis were abnormally high in the absence of Mkrn 2. To identify specific gene(s) involved, we performed digital gene expression profiling (DGE) and pathway analysis via gene set enrichment analysis (GSEA) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and we found that MKRN2 inhibits p53 apoptosis effector related to PMP22 (PERP) expression and that levels of the protein in sperm samples have an inverse correlation with infertility levels. GSEA additionally indicated that PERP is a negative regulator of spermatogenesis and that its ectopic expression induces male infertility. Further, Gene Expression Omnibus (GEO) dataset analysis showed that p53, upstream of PERP, was upregulated in oligoasthenoteratozoospermia (OAT). These observations suggest that Mkrn 2 is crucial for protecting germ cells from excessive apoptosis and implicate Mkrn 2-based suppression of the p53/PERP signaling pathway in spermatogenesis and male fertility.
ABSTRACT
ABSTRACT:Objective To construct a recombinant adenovirus vector harboring fusion gene NT4p53(C22)Ant and study its killing effect on HepG2 tumor cells.Methods Using molecular cloning technology,the rAVV-NT4p53(C22)Ant was produced by homologous recombination.Then we collected virus supernatant and measured its titer after it was amplified by PCR.The effect of this fusion gene on HepG2 tumor cells was evaluated by IHC, MTT assay,PI staining and flow cytometry.Results The recombinant adenovirus was successfully constructed. The p53 expression rate in rAAV-NT4p53(C22)Ant group was (44.88±2.45)%.MTT assay showed that rAAV-NT4p53(C22)Ant could strongly suppress the growth of HepG2 tumor cells.Flow cytometry showed that rAAV-NT4p53(C22)Ant could induce obvious apoptosis of HepG2 tumor cells.Conclusion The recombinant adenovirus vector encoding gene NT4p53(C22)Ant has been successfully constructed and expressed in this experiment,and it can inhibit proliferation and induce apoptosis of HepG2 tumor cells.
ABSTRACT
Background: PTPN22 codifies for a protein-tyrosine-phosphatase (Lyp) involved in T cell receptor signaling regulation. p53 is involved in immune related inflammation regulating STAT 1 and pro-inflammatory cytokines. Possible interaction between the two systems concerning the susceptibility to immune related disorders are therefore biologically plausible. In the present note we have searched for such interaction in type 1 diabetes mellitus and reviewed previous data from our laboratory. Methods: We have studied 287 children with type 1 diabetes, 129 non diabetic adult subjects admitted to the Hospital for Coronary Artery Disease, 130 women with endometriosis and 256 healthy blood donors. PTPN22 and p53 codon 72 genotypes were determined by DNA analysis. Results: In all diseases the proportion of PTPN22 *T allele is higher in p53 *Pro allele carriers than in p53*Arg/*Arg genotype. In *Arg/*Arg patients the proportion of *T allele carriers does not differ significantly from controls while in subjects carrying the *Pro allele is higher in patients than in controls. A significant increase of Odds Ratio is observed only in presence of both *T and *Pro alleles suggesting a cooperative interaction. Conclusion: It has been suggested that the susceptibility to autoimmune disorders in the presence of *T allele could be related to failure to delete auto reactive T cell during intrathymic selection. *Pro allele variant with its strong transcriptional activity could enhance the multiplication of such auto reactive T cell escaping intrathymic thus explaining a significant increase of Odds Ratio in the presence of both factors .The present observation could have relevance to identify individuals at high risk of clinical manifestations.