Brown adipose tissue and lipid metabolism

TY - JOUR

T1 - Brown adipose tissue and lipid metabolism

AU - Heeren, Joerg

AU - Scheja, Ludger

PY - 2018/6

Y1 - 2018/6

N2 - PURPOSE OF REVIEW: This article explores how the interplay between lipid metabolism and thermogenic adipose tissues enables proper physiological adaptation to cold environments in rodents and humans.RECENT FINDINGS: Cold exposure triggers systemic changes in lipid metabolism, which increases fatty acid delivery to brown adipose tissue (BAT) by various routes. Next to fatty acids generated intracellularly by de-novo lipogenesis or by lipolysis at lipid droplets, brown adipocytes utilize fatty acids released by white adipose tissue (WAT) for adaptive thermogenesis. WAT-derived fatty acids are internalized directly by BAT, or indirectly after hepatic conversion to very low-density lipoproteins and acylcarnitines. In the postprandial state, chylomicrons hydrolyzed by lipoprotein lipase - activated specifically in thermogenic adipocytes - are the predominant fatty acid source. Cholesterol-enriched chylomicron remnants and HDL generated by intravascular lipolysis in BAT are cleared more rapidly by the liver, explaining the antiatherogenic effects of BAT activation. Notably, increased cholesterol flux and elevated hepatic synthesis of bile acids under cold exposure further promote BAT-dependent thermogenesis.SUMMARY: Although pathways providing fatty acids for activated BAT have been identified, more research is needed to understand the integration of lipid metabolism in BAT, WAT and liver, and to determine the relevance of BAT for human energy metabolism.

AB - PURPOSE OF REVIEW: This article explores how the interplay between lipid metabolism and thermogenic adipose tissues enables proper physiological adaptation to cold environments in rodents and humans.RECENT FINDINGS: Cold exposure triggers systemic changes in lipid metabolism, which increases fatty acid delivery to brown adipose tissue (BAT) by various routes. Next to fatty acids generated intracellularly by de-novo lipogenesis or by lipolysis at lipid droplets, brown adipocytes utilize fatty acids released by white adipose tissue (WAT) for adaptive thermogenesis. WAT-derived fatty acids are internalized directly by BAT, or indirectly after hepatic conversion to very low-density lipoproteins and acylcarnitines. In the postprandial state, chylomicrons hydrolyzed by lipoprotein lipase - activated specifically in thermogenic adipocytes - are the predominant fatty acid source. Cholesterol-enriched chylomicron remnants and HDL generated by intravascular lipolysis in BAT are cleared more rapidly by the liver, explaining the antiatherogenic effects of BAT activation. Notably, increased cholesterol flux and elevated hepatic synthesis of bile acids under cold exposure further promote BAT-dependent thermogenesis.SUMMARY: Although pathways providing fatty acids for activated BAT have been identified, more research is needed to understand the integration of lipid metabolism in BAT, WAT and liver, and to determine the relevance of BAT for human energy metabolism.

KW - Adipose Tissue, Brown/cytology

KW - Adipose Tissue, White/cytology

KW - Animals

KW - Energy Metabolism/physiology

KW - Fatty Acids/metabolism

KW - Humans

KW - Lipid Droplets/metabolism

KW - Lipolysis/physiology

KW - Liver/cytology

U2 - 10.1097/MOL.0000000000000504

DO - 10.1097/MOL.0000000000000504

M3 - SCORING: Review article

C2 - 29718003

VL - 29

SP - 180

EP - 185

JO - CURR OPIN LIPIDOL

JF - CURR OPIN LIPIDOL

SN - 0957-9672

IS - 3

ER -