IGF-1 induces foam cell formation in rat glomerular mesangial cells.
When rat glomerular mesangial cells (MCs) are cultured with IGF-1 they accumulate intracellular lipid and take on foam cell morphology. These changes were characterized by electron microscopy and Nile red staining. To define the mechanism responsible for IGF-1-mediated lipid uptake, MCs were evaluated for endocytosis, scavenger receptor activity, and receptor-mediated uptake by the LDL receptor. Lipid accumulation was markedly increased when MCs were cultured with IGF. The primary route of uptake was through enhanced endocytosis. Lipid-laden MCs have decreased phagocytic capacity and disrupted cytoskeletons. These data show that IGF-1 induces MC to take on a foam cell morphology and that lipid-laden MCs have impaired phagocytic function.
Berfield
Anne K
AK
Veteran Affairs Puget Sound Health Care System, Seattle, Washington 98108, USA.
Abrass
Christine K
CK
D000818:Animals; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000648:ultrastructure; D004705:Endocytosis; D005487:Foam Cells / Q000502:physiology* / Q000648:ultrastructure; D005920:Glomerular Mesangium / Q000166:cytology* / Q000502:physiology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D050356:Lipid Metabolism; D008565:Membrane Proteins; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D010587:Phagocytosis; D051381:Rats; D011971:Receptors, Immunologic / Q000378:metabolism; D011973:Receptors, LDL / Q000502:physiology; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B
D008565:Membrane Proteins; D011971:Receptors, Immunologic; D011973:Receptors, LDL; D018110:Receptors, Lipoprotein; D051116:Receptors, Scavenger; C454739:Scarb1 protein, mouse; D051122:Scavenger Receptors, Class B; D007334:Insulin-Like Growth Factor I