PRKAA1 and colitis: In this study, we found that (Burkle and Hanfling, 2015) the active form of AMPK (phosphorylation on Tyr172) was decreased during the progression of colitis in colonic epithelial cells in mice; (Burkewitz et al., 2014) administration of metformin, a classic drug to activate AMPK, attenuated symptoms of colitis significantly; (Zheng and Cantley, 2007) the underlying mechanism of preventing colitis by metformin relied on its regulation of tight junctions via AMPK activation.