Mitochondrial Fractions Located in the Cytoplasmic and Peridroplet Areas of White Adipocytes Have Distinct Roles

The role of mitochondria in white adipocytes (WAs) has not been fully explored. A recent study revealed that brown adipocytes contain functionally distinct mitochondrial fractions, cytoplasmic mitochondria, and peridroplet mitochondria. However, it is not known whether such a functional division of mitochondria exists in WA. Herein, we observed that mitochondria could be imaged and mitochondrial DNA and protein detected in pellets obtained from the cytoplasmic layer and oil layer of WAs after centrifugation. The mitochondria in each fraction were designated as cytoplasmic mitochondria (CMw) and peridroplet mitochondria (PDMw) in WAs, respectively. CMw had higher beta-oxidation activity than PDMw, and PDMw was associated with diacylglycerol acyltransferase 2. Therefore, CMw may be involved in beta-oxidation and PDMw in droplet expansion in WAs. White adipocytes contain two mitochondrial fractions: cytoplasmic mitochondria (CMw) and peridroplet mitochondria (PDMw). The formation of PDMw is partially regulated by perilipin 1 (PLIN1). CMw is responsible for beta-oxidation, whereas PDMw is associated with diacylglycerol acyltransferase 2 (DGAT2) and contributes to the supply of triglycerides to lipid droplets. image