Remnant lipoprotein particles are taken up into myocardium through VLDL receptor--a possible mechanism for cardiac fatty acid metabolism.
The VLDL (very low-density lipoprotein) receptor is a peripheral lipoprotein receptor expressing in fatty acid active tissues abundantly. In the Balb/c fasting mice, VLDL receptor as well as LPL (lipoprotein lipase), FAT (fatty acid translocase)/CD36, H-FABP (heart-type fatty acid-binding protein), ACS (acyl-CoA synthetase) and LCAD (long-chain acyl-CoA dehydrogenase) expressions increased. An electron microscopic examination indicated the lipid droplets that accumulated in the hearts of fasting Balb/c mice. During the development of SD (Sprague-Dawley) rats, VLDL receptor, LPL, FAT/CD36, H-FABP, ACS, and LCAD mRNAs concomitantly increased with growth. However, PK (pyruvate kinase) mRNA expression was negligible. In cultured neonatal rat cardiomyocytes, VLDL receptor expression increased with days in culture. Oil red-O staining showed that cardiomyocytes after 7 days in culture (when the VLDL receptor protein is present) accumulated beta-migrating VLDL. Thereby, we showed that the cardiac VLDL receptor pathway for delivery of remnant lipoprotein particles might be part of a cardiac fatty acid metabolism.
Kamataki
Akihisa
A
Tohoku University Gene Research Center, Sendai, Japan
Takahashi
Sadao
S
Masamura
Katsuhiko
K
Iwasaki
Tadao
T
Hattori
Hiroaki
H
Naiki
Hironobu
H
Yamada
Kazuya
K
Suzuki
Jinya
J
Miyamori
Isamu
I
Sakai
Juro
J
Fujino
Takahiro
T
Yamamoto
Tokuo T
TT
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D004705:Endocytosis; D005215:Fasting; D005227:Fatty Acids / Q000378:metabolism*; D006321:Heart / Q000254:growth & development; D007700:Kinetics; D008055:Lipids / Q000032:analysis; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009206:Myocardium / Q000378:metabolism* / Q000648:ultrastructure; D019301:Oleic Acid / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011973:Receptors, LDL / Q000235:genetics / Q000378:metabolism*
D005227:Fatty Acids; D008055:Lipids; D008079:Lipoproteins, VLDL; D012333:RNA, Messenger; D011973:Receptors, LDL; C036053:VLDL receptor; D019301:Oleic Acid