Beta-very low density lipoprotein induces triglyceride accumulation through receptor mediated endocytotic pathway in 3T3-L1 adipocytes.
To elucidate the mechanism of triglyceride (TG) accumulation in adipocytes induced by TG-rich lipoproteins, we examined the effect of beta-very low density lipoprotein (beta-VLDL) on TG accumulation in 3T3-L1 adipocytes. Beta-VLDL did not induce TG accumulation in 3T3-L1 preadipocytes but in 3T3-L1 adipocytes. TG accumulation was significantly inhibited by cytochalasin B, an inhibitor of receptor mediated endocytosis. In contrast, cytochalasin B did not inhibit free fatty acid induced TG accumulation in adipocytes. The binding of [125I]beta-VLDL to preadipocytes was inhibited completely by both beta-VLDL and LDL. In sharp contrast, the binding of [125I]beta-VLDL to adipocytes was inhibited completely by beta-VLDL, but partially by LDL. The VLDL receptor mRNA was only expressed in adipocytes. These results suggest that beta-VLDL induced TG accumulation in adipocytes may be mediated through the VLDL receptor pathway.
Yano
T
T
Department of Metabolic Medicine, Kumamoto University School of Medicine, Honjo, Japan.
Kobori
S
S
Sakai
M
M
Anami
Y
Y
Matsumura
T
T
Matsuda
H
H
Kasho
M
M
Shichiri
M
M
D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology / Q000378:metabolism* / Q000502:physiology*; D000818:Animals; D015152:Blotting, Northern; D002454:Cell Differentiation / Q000187:drug effects; D004705:Endocytosis / Q000187:drug effects; D008079:Lipoproteins, VLDL / Q000502:physiology*; D051379:Mice; D011485:Protein Binding / Q000187:drug effects; D011817:Rabbits; D011973:Receptors, LDL / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects; D013234:Stem Cells / Q000166:cytology; D014280:Triglycerides / Q000378:metabolism*
D008079:Lipoproteins, VLDL; D011973:Receptors, LDL; D014280:Triglycerides; C036053:VLDL receptor