THE CYTOPROTECTIVE EFFECT OF INTERLEUKIN 4 ON FIBROBLASTS COCULTERED WITH THE MONONUCLEARS OF PATIENTS WITH TYPE 2 DIABETES MELLITUS AND THOSE WITH TYPE 2 DIABETES MELLITUS AND CHRONIC FOOT ULCERS IN A 3D CULTURE MODEL

Our research focused on the role of immune mechanisms in diabetic foot ulcers development and impaired healing. A 3D skin culture system, as a relevant skin model, has proved valuable in investigating these mechanisms and is a useful tool to study interactions between keratinocytes, fibroblasts and immune cells. The aim of this study was to evaluate the effect of IL1 and IL4 on the keratinocytes and fibroblasts viability and assess endogenous interleukin (IL1,4,6,8) production into the culture medium by the skin cells cocultured with mononuclears of patients with type 2 diabetes mellitus (T2DM) and those with T2DM and chronic foot ulcers (CFU) in a 3D culture model. The main result of this study was the protective effect of IL4 on fibroblasts – this interleukin (50 pg/ml) significantly increased the percentage of viable fibroblasts cocultured with keratinocytes, mononuclears and blood serum of T2DM patients (85.13 [80.81; 87.82]% vs. 90.34 [85.92; 94.74]%, T=-2.668, p=0.008) and those with T2DM and CFU (70.42 [68.10; 74.79]% vs. 82.10 [76.37; 84.39]%, T = -2.666, p=0.008). IL1 in high concentration potentiated the toxic effect of mononuclears in T2DM and T2DM with CFU patients on fibroblasts and also decreased keratinocytes viability in the 3D culture system. An increase in IL1 and absence of a sufficient and significant decrease in IL6 production into the culture medium during 24-hour coincubation of skin cells with T2DM patients mononuclears indicate the activation of immune mechanisms and the maintenance of persistent inflammatory response.