Lipodystrophies: disorders of adipose tissue biology.
The adipocytes synthesize and store triglycerides as lipid droplets surrounded by various proteins and phospholipids at its surface. Recently, the molecular basis of some of the genetic syndromes of lipodystrophies has been elucidated and some of these genetic loci have been found to contribute to lipid droplet formation in adipocytes. The two main types of genetic lipodystrophies are congenital generalized lipodystrophy (CGL) and familial partial lipodystrophy (FPL). So far, three CGL loci: 1-acylglycerol-3-phosphate-O-acyltransferase 2 (AGPAT2), Berardinelli-Seip Congenital Lipodystrophy 2 (BSCL2) and caveolin 1 (CAV1) and four FPL loci: lamin A/C (LMNA), peroxisome proliferator-activated receptor gamma (PPARG), v-AKT murine thymoma oncogene homolog 2 (AKT2) and zinc metalloprotease (ZMPSTE24), have been identified. AGPAT2 plays a critical role in the synthesis of glycerophospholipids and triglycerides required for lipid droplet formation. Another protein, seipin (encoded by BSCL2 gene), has been found to induce lipid droplet fusion. CAV1 is an integral component of caveolae and might contribute towards lipid droplet formation. PPARgamma and AKT2 play important role in adipogenesis and lipid synthesis. In this review, we discuss and speculate about the contribution of various lipodystrophy genes and their products in the lipid droplet formation.
Garg
Abhimanyu
A
Division of Nutrition and Metabolic Diseases, Department of Internal Medicine, Center for Human Nutrition, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, USA. abhimanyu.garg@utsouthwestern.edu
Agarwal
Anil K
AK
D017667:Adipocytes / Q000201:enzymology / Q000378:metabolism*; D000818:Animals; D051242:Caveolin 1 / Q000378:metabolism; D044388:GTP-Binding Protein gamma Subunits / Q000378:metabolism; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000378:metabolism; D006801:Humans; D034904:Lamin Type A / Q000378:metabolism; D050356:Lipid Metabolism / Q000235:genetics; D052497:Lipodystrophy, Congenital Generalized / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D052496:Lipodystrophy, Familial Partial / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D008565:Membrane Proteins / Q000378:metabolism; D008666:Metalloendopeptidases / Q000378:metabolism; D015388:Organelles / Q000201:enzymology / Q000378:metabolism*; D047495:PPAR gamma / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism
C432679:BSCL2 protein, human; C495540:CAV1 protein, human; D051242:Caveolin 1; D044388:GTP-Binding Protein gamma Subunits; C494847:LMNA protein, human; D034904:Lamin Type A; D008565:Membrane Proteins; D047495:PPAR gamma; D005992:Glycerol-3-Phosphate O-Acyltransferase; C494921:AKT2 protein, human; D051057:Proto-Oncogene Proteins c-akt; D008666:Metalloendopeptidases; C120130:ZMPSTE24 protein, human