Lipoprotein lipase activity is required for cardiac lipid droplet production.
The rodent heart accumulates TGs and lipid droplets during fasting. The sources of heart lipids could be either FFAs liberated from adipose tissue or FAs from lipoprotein-associated TGs via the action of lipoprotein lipase (LpL). Because circulating levels of FFAs increase during fasting, it has been assumed that albumin transported FFAs are the source of lipids within heart lipid droplets. We studied mice with three genetic mutations: peroxisomal proliferator-activated receptor α deficiency, cluster of differentiation 36 (CD36) deficiency, and heart-specific LpL deletion. All three genetically altered groups of mice had defective accumulation of lipid droplet TGs. Moreover, hearts from mice treated with poloxamer 407, an inhibitor of lipoprotein TG lipolysis, also failed to accumulate TGs, despite increased uptake of FFAs. TG storage did not impair maximal cardiac function as measured by stress echocardiography. Thus, LpL hydrolysis of circulating lipoproteins is required for the accumulation of lipids in the heart of fasting mice.
Division of Preventive Medicine and Nutrition, Columbia University College of Physicians and Surgeons, New York, NY 10032.
Chad M
CM
Trent
Shuiqing
S
Yu
Yunying
Y
Hu
Nathan
N
Skoller
Lesley A
LA
Huggins
Shunichi
S
Homma
Ira J
IJ
Goldberg
D000818:Animals; D005215:Fasting; D006868:Hydrolysis; D066292:Lipid Droplets / Q000502:physiology*; D050356:Lipid Metabolism; D008071:Lipoprotein Lipase / Q000502:physiology*; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009206:Myocardium / Q000378:metabolism*; D047493:PPAR alpha / Q000235:genetics; D000070780:Perilipin-2; D000070797:Perilipin-5; D011506:Proteins / Q000378:metabolism; D013599:Systole; D014280:Triglycerides / Q000097:blood
D008074:Lipoproteins; D008565:Membrane Proteins; D047493:PPAR alpha; D000070780:Perilipin-2; D000070797:Perilipin-5; C511805:Plin5 protein, mouse; D011506:Proteins; D014280:Triglycerides; D008071:Lipoprotein Lipase
Cd36; PPAR; triglyceride