What are the physiological roles of autophagy?

Autophagy serves several critical physiological roles within the cell and the body as a whole.

• It plays a crucial role in maintaining normal cellular function by degrading misfolded proteins and damaged organelles. This process ensures that cells function optimally and maintain their overall health and homeostasis.
• The process of autophagy serves as a survival mechanism in eukaryotic cells, especially in responding to stress conditions such as starvation or oxidative stress. It helps cells survive and recover by degrading and recycling macromolecules such as carbohydrates, proteins and lipids to provide essential components and energy when resources are limited.
• Autophagy functions as the body's quality control mechanism by breaking down old, damaged and dysfunctional cell components and recycling salvageable components into new, functional cell parts. This process helps remove cellular clutter and maintain optimal cellular health and functionality.
• Autophagy also supports the body's immune response by engulfing and breaking down invading pathogens such as viruses and bacteria within the cell, thereby curbing the spread of the infection.  
• During autophagy, various metabolic substances, including amino acids, glucose, and fatty acids are generated through the degradation of self-components. This process can supply energy and building blocks for the synthesis of new materials, even under normal physiological conditions.
• The process of autophagy is crucial for adult stem cells self-renewal, differentiation, and resistance to stress conditions. This supports tissue repair and regeneration in various tissues and organs where adult stem cells are present.