title: Telemetric control of peripheral lipophagy by hypothalamic autophagy.
abstract: Autophagy maintains cellular quality control by degrading organelles, and cytosolic proteins and their aggregates in lysosomes. Autophagy also degrades lipid droplets (LD) through a process termed lipophagy. During lipophagy, LD are sequestered within autophagosomes and degraded by lysosomal acid lipases to generate free fatty acids that are β-oxidized for energy. Lipophagy was discovered in hepatocytes, and since then has been shown to function in diverse cell types. Whether lipophagy degrades LD in the major fat storing cell-the adipocyte-remained unclear. We have found that blocking autophagy in brown adipose tissues (BAT) by deleting the autophagy gene Atg7 in BAT MYF5 (myogenic factor 5)-positive progenitors increases basal lipid content in BAT and decreases lipid utilization during cold exposure-indicating that lipophagy contributes to lipohomeostasis in the adipose tissue. Surprisingly, knocking out Atg7 in hypothalamic proopiomelanocortin (POMC) neurons also blocks lipophagy in BAT and liver suggesting that specific neurons within the central nervous system (CNS) exert telemetric control over lipophagy in BAT and liver.
authors.affiliation: a Institute for Cell and Molecular Biosciences, Institute for Aging, Newcastle University , Newcastle upon Tyne , UK.
authors.forename: Nuria
authors.initials: N
authors.lastname: Martinez-Lopez
authors.affiliation: a Institute for Cell and Molecular Biosciences, Institute for Aging, Newcastle University , Newcastle upon Tyne , UK.|b Department of Medicine , Albert Einstein College of Medicine , Bronx , NY USA.|c Department of Molecular Pharmacology , Albert Einstein College of Medicine , Bronx , NY USA.|d Diabetes Research Center, Albert Einstein College of Medicine , Bronx , NY USA.|e Institute for Aging Studies, Albert Einstein College of Medicine , Bronx , NY USA.
authors.forename: Rajat
authors.initials: R
authors.lastname: Singh
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D000071182:Autophagosomes / Q000378:metabolism*; D001343:Autophagy; D000071193:Autophagy-Related Protein 7 / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D022781:Hepatocytes / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism*; D066292:Lipid Droplets; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008066:Lipolysis; D008099:Liver / Q000378:metabolism; D008247:Lysosomes / Q000378:metabolism; D051379:Mice; D051787:Myogenic Regulatory Factor 5 / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D010100:Oxygen / Q000737:chemistry; D011333:Pro-Opiomelanocortin / Q000378:metabolism
chemical_list: C502661:Atg7 protein, mouse; D005230:Fatty Acids, Nonesterified; D008055:Lipids; C497418:Myf5 protein, mouse; D051787:Myogenic Regulatory Factor 5; D011333:Pro-Opiomelanocortin; D000071193:Autophagy-Related Protein 7; D010100:Oxygen
keywords: POMC; adipose; autophagy; cold; lipophagy