Inhibitor of pro-apoptotic PERK-dependent signalling pathway as a novel treatment strategy in Alzheimer’s disease treatment

Abstract

Objectives. The newest data reported that Alzheimer’s disease (AD) pathogenesis and progression are correlated with excessive activation of Endoplasmic Reticulum (ER) stress conditions and, as a result, pro-apoptotic branch of the protein kinase RNA-like ER kinase (PERK)-dependent Unfolded Protein Response (UPR) signalling pathway, in which the major apoptotic marker constitutes C/EBP homologous protein (CHOP). The aims of the study were the evaluation of LDN-0060609 in terms of its inhibitory activity towards pro-apoptotic branch of the PERK-dependent UPR signalling pathway as well as evaluation of LDN-0060609 cytotoxicity. Material and methods. Research was conducted on mouse neurons CATH.a. Cells were incubated with LDN-0060609 at the concentration range and with thapsigargin as an activator of ER stress. Evaluation of CHOP protein level was performed by Western Blot technique; apoptosis analysis – by flow cytometry; whereas evaluation of LDN-0060609 cytotoxicity – by XTT assay. Results. The results of the study showed that inhibitor LDN-0060609 at 25μM concentration evokes 80% decrease in the CHOP protein level as compared to untreated control cells. Additionally, at 25μM, LDN-0060609 effectively inhibits apoptosis in cells with activated ER stress. Only 5.6% less viable cells were shown as compared to control cells incubated with 0.01% DMSO. LDN-0060609 did not evoke a cytotoxic effect at any used concentrations and incubation times. Conclusions. The results of our own research showed that LDN-0060609 inhibitor effectively inhibits apoptosis-mediated neuronal cell death and does not evoke a cytotoxic effect. Thus, low-molecular inhibitors of pro-apoptotic branch of PERK-dependent UPR signalling pathway may constitute an innovative therapeutic strategy for AD treatment.