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.