The significance of macroautophagy in health and disease

During the past decade there has been a substantial increase in macroautophagy (herein simply referred to as autophagy) research due to a growing understanding of this process, coupled with improved new techniques for its detection. Autophagy (auto - self, phagy - eating) is defined as a fundamental lysosomal catabolic pathway responsible for degrading long-lived proteins, protein aggregates, oxidised lipids, damaged organelles, and even microbial invaders. Although autophagy occurs at basal levels in normal conditions, many different forms of metabolic stress, including starvation, hypoxia, high temperature, high culture density, hormones, and growth factor deprivation can dramatically stimulate an autophagic response. Autophagy plays a critical role in maintaining cellular homeostasis and genomic integrity and therefore has been implicated in many physiological activities such development, differentiation, and tissue remodelling. Consequently, defects in autophagy have been linked to various human diseases such as neurodegenerative and muscle disorders, cancers, cardiac failure, and inflammatory disorders. This mini-review summarises current knowledge in a field of mammalian autophagy and considers the significance of autophagy in human physiology and pathology.