Modulation of Autophagy by Free Fatty Acids

Fatty acids are important molecules with multiple biological properties. Emerging evidence suggests that fatty acids can modulate autophagy. Saturated fatty acids contribute to pancreatic β-cell dysfunction in type 2 diabetes. Palmitic acid, one of the long-chain saturated fatty acids (LCFA), induces autophagy of β-cells which protects them from dysfunctions and apoptotic cell death. Short-chain fatty acids (SCFA) possess antitumor activity in colon cancer cells by promoting autophagy. SCFAs can induce autophagy by suppressing the activity of mTOR signaling. As the most common monosaturated fatty acid (MUFA) in daily nutrition, oleic acid could induce autophagy, which is responsible for the regulation of lipids metabolism in hepato‐ cytes. The ω-3 and ω-6 polyunsaturated fatty acids (PUFA) are essential in normal physiology and metabolism and play a contributory role in the incidence and progress of a series of disease including cancer. Autophagy triggered by ω-3 PUFAs contributes to the cytotoxicity in cancer cells by enhancing apoptosis, while autophagy mediated by ω-6 PUFAs led to the increase in Caenorhabditis elegans lifespan. The recent findings illustrate the potential involvement of autophagy regulation by fatty acids in a number of biological and pathological processes.