Human MAPK1 blocking peptide

Genes belonging to neuroplasticity, monoamine, circadian rhythm, and transcription factor pathways were investigated as modulators of antidepressant efficacy. The present study aimed (1) to replicate previous findings in an independent sample with treatment-resistant depression (TRD), and (2) to perform a pathway analysis to investigate the possible molecular mechanisms involved. 220 patients with major depressive disorder who were non-responders to a previous antidepressant were treated with venlafaxine for 4-6 weeks and in case of non-response with escitalopram for 4-6 weeks. Symptoms were assessed using the Montgomery Asberg Depression Rating Scale. The phenotypes were response and remission to venlafaxine, non-response (TRDA) and non-remission (TRDB) to neither venlafaxine nor escitalopram. 50 tag SNPs in 14 genes belonging to the pathways of interest were tested for association with phenotypes. Molecular pathways (KEGG database) that included one or more of the genes associated with the phenotypes were investigated also in the STAR*D sample. The associations between ZNF804A rs7603001 and response, CREB1 rs2254137 and remission were replicated, as well as CHL1 rs2133402 and lower risk of TRD. Other CHL1 SNPs were potential predictors of TRD (rs1516340, rs2272522, rs1516338, rs2133402). The MAPK1 rs6928 SNP was consistently associated with all the phenotypes. The protein processing in endoplasmic reticulum pathway (hsa04141) was the best pathway that may explain the mechanisms of MAPK1 involvement in antidepressant response. Signals in genes previously associated with antidepressant efficacy were confirmed for CREB1, ZNF804A and CHL1. These genes play pivotal roles in synaptic plasticity, neural activity and connectivity.

In this study, we have identified one microRNA, microRNA 493 (miR-493), which could simultaneously and directly regulate multiple genes downstream of the insulin-like growth factor 1 receptor (IGF1R) pathway, including IGF1R, by binding with complementary sequences in the 3' untranslated region (UTR) of mRNAs of IGF1R, insulin receptor substrate 1 (IRS1), and mitogen-activated protein kinase 1 (MAPK1), thereby potentiating their inhibitory function at multiple levels in development and progression of cancers. This binding was further confirmed by pulldown of miR with AGO-2 antibody. Further, results from head and neck samples showed that miR-493 levels were significantly downregulated in tumors, with a concomitant increase in the expression of IGF1R and key downstream effectors. Functional studies from miR-493 overexpression cells and nude-mouse models revealed the tumor suppressor functions of miR-493. Regulation studies revealed that Snail binds to the miR-493 promoter and represses it. We found the existence of a dynamic negative feedback loop in the regulation of IGF1R and miR-493 mediated via Snail. Our study showed that nicotine treatment significantly decreases the levels of miR-493-with a concomitant increase in the levels of Snail-an indication of progression of cells toward tumorigenesis, reestablishing the role of tobacco as a major risk factor for head and neck cancers and elucidating the mechanism behind nicotine-mediated tumorigenesis.