Expression of delta-catenin
FDA-approved Drug Library induces filopodia-like protrusions in neurons. Here we show that the small GTPases of the Rho family act coordinately as downstream effectors of delta-catenin. A dominant negative Rac prevented delta-catenin-induced protrusions, and Cdc42 activity was dramatically increased by delta-catenin expression. A kinase dead LIMK (LIM kinase) and a mutant Cofilin also prevented delta-catenin-induced protrusions. To link the effects of delta-catenin to a physiological pathway, we noted that (S)-3,5-dihydroxyphenylglycine (DHPG) activation of metabotropic glutamate receptors induced dendritic protrusions that are very similar to those induced by delta-catenin. Furthermore, delta-catenin RNA-mediated interference can block the induction of dendritic protrusions by DHPG. Interestingly, DHPG dissociated PSD-95 and N-cadherin from the delta-catenin complex, increased the association of delta-catenin with Cortactin, and induced the phosphorylation of delta-catenin within the sites that bind to these protein partners.”
“Our objectives
were to evaluate the effects of mono(2-ethylhexyl) phthalate (MEHP) on tight junctions (TJ) in cultured rat Sertoli cells (SC) and to investigate changes in the signal transduction pathways in SCs following MEHP treatment. SCs were isolated and purified from the testes of 18-day-old Sprague Dawley rats and incubated at 34 degrees C for C59 clinical trial 3 days. After treatment of SCs with either the vehicle or MEHP for 0.5, 1, 3, 6 and 24 hours, whole cell lysates were isolated from each replicate to prepare RNA and protein. Expression levels of claudin-11, occludin, and zonula occludens-1 (ZO-1) mRNA were evaluated by quantitative real-time
reverse transcription polymerase chain reaction Staurosporine mw and changes in signal transduction pathways possibly induced by MEHP treatment were assessed by Western blot analyses. MEHP treatment led to significant decreases in the expression of claudin-11 and occludin mRNA, but not that of ZO-1, in rat SCs. Exposure of rat SCs to MEHP resulted in the marked induction of phosphorylated p44/42 mitogen-activated protein kinase (MARK), whereas other pathways examined in this study were not activated by MEHP. Furthermore, treatment of rat SCs with a specific inhibitor of p44/42 MARK prevented the MEHP-induced down-regulation of claudin-11 and occludin. These findings demonstrate that MEHP exposure inhibited the expression of claudin-11 and occludin mRNA in rat SCs through the p44/42 MARK pathway, suggesting the possible involvement of MEHP in spermatogenic function by regulating major components of TJs in SCs.”
“OBJECTIVE.