Mesenchymal stem/stromal cells preconditioning with Glibenclamide augment their immunoregulatory characteristics

Background & Aim Mesenchymal stem/stromal cells (MSCs) displayed potent immunosuppressive and anti-inflammatory properties, highlighting their potential application for treating inflammatory disorders. Being regulated by some pro-inflammatory cytokines, MSCs regulate nearly all immune cell populations. Previous studies showed that priming these cells with some agents could increase the paracrine effects of these cells to boost their therapeutic efficacy. Glibenclamide (Gly) causing hypoglycemia is broadly applicable in the type II diabetes mellitus. Besides, its protective role was shown in some inflammation-induced injuries. The anti-inflammatory effect of Gly is associated with reduced production of pro-inflammatory cytokines. This study aimed to investigate the effects of Gly on the immunomodulatory properties of MSCs. Methods, Results & Conclusion Human MSCs were isolated from the waste lipoaspirates (60 ml) obtained from healthy donors after informed consent, which was approved by the local ethics committee (IR.ACECR.JDM.REC.1396.7). The cytotoxicity of Gly on Adipose-derived MSCs (Ad-MSCs) was assessed through MTT (treatment with 50, 100, 200, and 500 μM of Gly for 24, 48, and 72 h). Ad-MSCs were treated with 500 μM of the Gly for 24 hours, the expression of pro-inflammatory cytokines including IL-1, IL-6, IL-8, MCP-1, and HGF, were evaluated via qPCR. The expression of an apoptotic related gene, caspase I, was also measured. Then, the impact of Gly on LPS -induced preventative effects were investigated through qPCR with the previous set of genes as well as TNF-α, following the induction of cells with LPS (5 Μg/ml for four h) and then treated with Gly for 24 h. The results of the MTT assay indicated that Gly in different concentrations, including 50, 100, 200, and 500 μM had no cytotoxicity effects on Ad-MSC. Priming these cells with Gly resulted in significantly decreased expression of some pro-inflammatory and also caspase genes (Fig. 1). Induction of Ad-MSCs with LPS led to increased expression of pro-inhibitory cytokines, and upon treatment of these cells with Gly, their pro-inflammatory effects were diminished (Fig. 2). These data suggest that pretreatment of MSCs with glibenclamide could enhance their immunomodulatory properties; hence it might be considered as a strategy to improve the efficiency of cellular therapy.