Effect of small molecule DMGV on gene expression, prolilferation and fuction of activated T cells

Activated effector T cells (Teff) and/or compromised regulatory T cells (Treg) underlie chronic inflammatory diseases. We discovered a novel pathway to inhibit survival and expansion of Teff without compromising Treg survival and a potential therapeutic to treat these diseases. We found dimethylguanidino valeric acid (DMGV) is a rheostat for Teff: while cell-intrinsic DMGV generated by Alanine-Glyoxylate Aminotransferase 2 (AGXT2) is essential for survival and expansion by inducing mitochondrial ROS, an excessive (or exogenous) DMGV level inhibits effector T cell survival, thereby the AGXT2-DMGV-ROS axis functioning as a switch to turn on and off Teff expansion via regulation of glycolysis. DMGV-induced ROS is essential for glycolysis, and paradoxically DMGV induces ROS only in cells utilizing glycolysis as the major source of energy. Mechanistically, DMGV rapidly activates mitochondrial calcium uniporter (MCU), causing a surge in mitochondrial Ca2+ without provoking calcium influx to the cytosol. The mitochondrial Ca2+ surge in turn triggers the mitochondrial Na+/Ca2+ exchanger (NCLX) and the subsequent mitochondrial Na+ import induces ROS by uncoupling the Coenzyme Q cycle in Complex III of the electron transport chain. In preclinical trials, DMGV administration significantly diminished the number of inflammatory T cells, effectively suppressing chronic inflammation in mouse models of colitis and rheumatoid arthritis. DMGV also suppressed expansion of various cancer cells in vitro and in a mouse T cell leukemic model by the same mechanism. Our data provide a new pathway regulating cell survival and a novel mode to treat autoimmune diseases and cancers. To investigate DMGV's effect on T cell gene expression and phenotypes, mouse splenic CD3+ T cells were activated with or without DMGV for 24h and the gene expression profiles were analyzed by RNAseq.The RNAseq was performed on triplicates of anti-CD3/CD28 activated mouse splenic CD3+ T cells with or without DMGV added.