#5607 EFFECTS OF COMMON OSMOLYTES ON THE EXPRESSION OF FOXP3 SPLICE VARIANTS IN HUMAN PBMCS

Abstract Background and Aims Regulatory T cells modulate autoimmune allogenic responses in glomerulonephritis transplantation. The two most abundant fork-head box P3 (FOXP3) splice variants, full-length FOXP3 (FOXP3-FL) lacking exon 2 (FOXP3-Δ 2), confer suppressive ability to regulatory cells. Some studies showed a weaker of FOXP3-Δ 2. Renal organic osmolytes, urea Trimethylamine N-oxide (TMAO), play critical roles the hyperosmotic renal environment with high concentrations Na+ glucose. However, effects these osmolytes on variants peripheral blood mononuclear (PBMCs) remain unclear. aim this study was evaluate common expression human PBMCs. Method PBMCs were isolated from healthy donors using Ficoll density gradients cultured RPMI-1640 or without additional at 37°C. A part activated 25ng/ml Phorbol-12-myristate-13-acetate (PMA) 1ug/ml ionomycin (PMA+IONO). FOXP3-FL mRNA detected by qPCR after 4hrs’ incubation, specific primers. relative value calculated formula (1+E0)∧ Ct0(β-actin)/(1+E)∧ Ct (target gene). Values are given as mean±S.E.M. Statistical significance determined One-Way ANOVA Post Hoc Test, Graphpad Prism 9. P-value <0.05 considered significant. Results cell viabilities 4 hours’ incubation all above 90%. PMA+IONO significantly increased both (from 0.001051 0.001609, P = 0.0289, n 5) 0.001024 0.001684, 0.0101, (Figure 1). 5mM 50mM) had no effect either (P > 0.05, 5, Figure TMAO 4um reduced PMA+IONO-activated 0.001605 0.0007208 0.0051, 2). didn’t affect non-activated little 4). On other hand, compared control group, concentration glucose (25mM) 0.002815 0.003461 0.0375, 3) NaCl (147mM) significant 3, Furthermore, equal osmolarity mannitol expressions But group (0.003461), lower (0.002785) 0.0479, It suggested that independent change. Conclusion In PBMCs, increases expressions. PMA+IONO-induced increase can be inhibited TMAO. Urea High which