selfdigestion

Self-digestion refers to the breakdown of an organism’s own tissues and cells by enzymes produced within the organism. It occurs in several contexts, including regulated cellular remodeling, disease-related tissue damage, and postmortem changes.

A central form of self-digestion in living cells is autophagy. In autophagy, components of the cytoplasm are enclosed within a membrane to form autophagosomes, which then fuse with lysosomes where the contents are degraded and recycled. Autophagy helps cells survive nutrient stress, clears damaged organelles, and influences development and immunity. Proper regulation of this process is important for cellular health; its dysregulation has been linked to cancer, neurodegenerative disorders, and infections.

Autolysis, by contrast, describes tissue breakdown caused by lysosomal enzymes after cell death. This postmortem self-digestion contributes to tissue disintegration and can affect the interpretation of histological samples and forensic assessments. In living disease states, premature activation of digestive enzymes within an organ—such as the pancreas—can cause autodigestion and tissue injury, illustrating how self-digestion can become pathogenic when regulation fails.

In developmental biology and some metamorphoses, controlled self-digestion assists remodeling, as certain tissues are selectively broken down to enable growth and transformation. Across contexts, self-digestion is a fundamental process that ranges from beneficial recycling and remodeling to harmful tissue damage when regulation is incomplete or absent.