Mitochondrial morphology in metabolic diseases.

SIGNIFICANCE: Mitochondria are the cellular energy-producing organelles and are at the crossroad of determining cell life and death. As such, the function of mitochondria has been intensely studied in metabolic disorders, including diabetes and associated maladies commonly grouped under all-inclusive pathological condition of metabolic syndrome. More recently, the altered metabolic profiles and function of mitochondria in these ailments have been correlated with their aberrant morphologies. This review describes an overview of mitochondrial fission and fusion machineries, and discusses implications of mitochondrial morphology and function in these metabolic maladies. RECENT ADVANCES: Mitochondria undergo frequent morphological changes, altering the mitochondrial network organization in response to environmental cues, termed mitochondrial dynamics. Mitochondrial fission and fusion mediate morphological plasticity of mitochondria and are controlled by membrane-remodeling mechanochemical enzymes and accessory proteins. Growing evidence suggests that mitochondrial dynamics play an important role in diabetes establishment and progression as well as associated ailments, including, but not limited to, metabolism-secretion coupling in the pancreas, nonalcoholic fatty liver disease progression, and diabetic cardiomyopathy. CRITICAL ISSUES: While mitochondrial dynamics are intimately associated with mitochondrial bioenergetics, their cause-and-effect correlation remains undefined in metabolic diseases. FUTURE DIRECTIONS: The involvement of mitochondrial dynamics in metabolic diseases is in its relatively early stages. Elucidating the role of mitochondrial dynamics in pathological metabolic conditions will aid in defining the intricate form-function correlation of mitochondria in metabolic pathologies and should provide not only important clues to metabolic disease progression, but also new therapeutic targets.