ABSTRACT
<p><b>AIM</b>To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Jun N-terminal kinases (JNK) and p38 mitogen-activated protein kinases (MAPK) in response to heat stress in the cryptorchid testis, and to investigate a possible relation to Sertoli cell dedifferentiation.</p><p><b>METHODS</b>Immunohistochemistry and western blot were used to examine the expression and activation of ERK1/2, p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism.</p><p><b>RESULTS</b>The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis. Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK. Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis. Changes in the spatiotemporal expression of cytokeratin 18 (CK18), a marker of immature or undifferentiated Sertoli cells, were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2.</p><p><b>CONCLUSION</b>The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.</p>
Subject(s)
Animals , Male , Cryptorchidism , Pathology , Disease Models, Animal , Enzyme Activation , Immunohistochemistry , MAP Kinase Kinase 4 , Metabolism , Macaca mulatta , Mitogen-Activated Protein Kinase 1 , Metabolism , Mitogen-Activated Protein Kinase 3 , Metabolism , Scrotum , p38 Mitogen-Activated Protein Kinases , MetabolismABSTRACT
The Cre recombinase from bacteriophage P1 can recognize specific DNA sequences, cleave DNA at specific target sites, and then ligate it to the cleaved DNA of a second site. In this study, cre gene was cloned into the pGEM-T Easy vector via PCR procedure. Then the cre gene was inserted into an expression vector pET-29a and expressed in E. coli BL21 (DE3). A 38 kD soluble protein was expressed and named CRE. CRE was purified by DEAE-52 chromatography. Bioassay of the partially purified product showed that CRE can cleave the plasmid pGLGFP which contains two loxP site with the same direction.