Detection of Cell Death by Autophagy

Autophagy (Greek: Self digestion) is an intracellular process involved in removal of damaged or misfolded proteins or organelles. Damaged or misfolded proteins or organelles are first engulfed in a membraneous structure called autophagosome, and then the autophagosome fuse with lysosome to form autophagolysosome, where the contents are digested. Autophagy is a catabolic process induced during nutritional depletion via phosphatidylinositol 3 kinase pathway. Autophagy is induced in several diseases such as various cancers, heart failure, etc. When autophagy is induced, several autophagic genes are upregulated that help the formation of autophagosome. Several autophagosome specific marker proteins have been identified, among them MAP1LC3-II protein, which is cleaved from MAP1LC3-I, is specifically incorporated into the autophagosomal membrane. The formation of MAP1LC3-II can be analyzed by Western immunoblotting or immunofluorescence. Detailed methods of detection of MAP1LC3-II by Western immunoblotting and immunofluorescence are described.