Fig. 4: Possible regulation of S1P on autophagy in IBD.
From: The role of sphingosine-1-phosphate in autophagy and related disorders
ATX is mainly derived from adipose tissue and can also be secreted by other cells, such as inflammatory macrophages and activated astrocytes. ATX can act as a synthase of S1P, degrading SPC to S1P. An increase in the level of ATX was detected in IBD. We suspect that ATX induces the S1P/S1PR/mTOR pathway and inhibits the S1P/S1PR/AMPK pathway to inhibit autophagy. The dysregulated autophagy then affects the distribution of gut microbiota, the immune response of intestinal mucosa, and the expression of tight junction protein, thereby affecting the epithelial barrier function, leading to the occurrence and development of IBD inflammation. Created with figdraw.com. ATX autotaxin, SPC sphingosylphosphorylcholine, APC antigen presenting cells, NK T natural killer T cells.
