Autophagy-physiology and pathophysiology.
"Autophagy" is a highly conserved pathway for degradation, by which wasted intracellular macromolecules are delivered to lysosomes, where they are degraded into biologically active monomers such as amino acids that are subsequently re-used to maintain cellular metabolic turnover and homeostasis. Recent genetic studies have shown that mice lacking an autophagy-related gene (Atg5 or Atg7) cannot survive longer than 12 h after birth because of nutrient shortage. Moreover, tissue-specific impairment of autophagy in central nervous system tissue causes massive loss of neurons, resulting in neurodegeneration, while impaired autophagy in liver tissue causes accumulation of wasted organelles, leading to hepatomegaly. Although autophagy generally prevents cell death, our recent study using conditional Atg7-deficient mice in CNS tissue has demonstrated the presence of autophagic neuron death in the hippocampus after neonatal hypoxic/ischemic brain injury. Thus, recent genetic studies have shown that autophagy is involved in various cellular functions. In this review, we introduce physiological and pathophysiological roles of autophagy.
Uchiyama
Yasuo
Y
Department of Cell Biology and Neuroscience, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan. y-uchi@anat1.med.osaka-u.ac.jp
Shibata
Masahiro
M
Koike
Masato
M
Yoshimura
Kentaro
K
Sasaki
Mitsuho
M
D000818:Animals; D001343:Autophagy / Q000235:genetics / Q000502:physiology*; D016923:Cell Death; D002490:Central Nervous System / Q000502:physiology / Q000503:physiopathology*; D022781:Hepatocytes / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D006529:Hepatomegaly / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D020925:Hypoxia-Ischemia, Brain / Q000503:physiopathology*; D007425:Intracellular Membranes / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D008247:Lysosomes / Q000502:physiology / Q000648:ultrastructure; D008928:Mitochondria / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D008954:Models, Biological; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D015388:Organelles / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D020675:Peroxisomes / Q000502:physiology; D013217:Starvation / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism
D025801:Ubiquitin