Inherent differences in morphology, proliferation, and migration in saphenous vein smooth muscle cells cultured from nondiabetic and Type 2 diabetic patients.
Individuals with Type 2 diabetes mellitus (T2DM) are at increased risk of saphenous vein (SV) graft stenosis following coronary artery bypass. Graft stenosis is caused by intimal hyperplasia, a pathology characterized by smooth muscle cell (SMC) proliferation and migration. We hypothesized that SV-SMC from T2DM patients were intrinsically more proliferative and migratory than those from nondiabetic individuals. SV-SMC were cultured from nondiabetic and T2DM patients. Cell morphology (light microscopy, immunocytochemistry), S100A4 expression (real-time RT-PCR, immunoblotting), proliferation (cell counting), migration (Boyden chamber assay), and cell signaling (immunoblotting with phosphorylation state-specific antibodies) were studied. SV-SMC from T2DM patients were morphologically distinct from nondiabetic patients and exhibited a predominantly rhomboid phenotype, accompanied by disrupted F-actin cytoskeleton, disorganized alpha-smooth muscle actin network, and increased focal adhesion formation. However, no differences were observed in expression of the calcium-binding protein S100A4, a marker of rhomboid SMC phenotype, between the two cell populations. T2DM cells were less proliferative in response to fetal calf serum than nondiabetic cells, but both populations had similar proliferative responses to insulin plus PDGF. Under high glucose concentration conditions in the presence of insulin, migration of diabetic SV-SMC was greater than nondiabetic cells. Glucose concentration did not affect SV-SMC proliferation. No differences in insulin or PDGF-induced phosphorylation of ERK-1/2 or components of the Akt pathway (Akt-Ser473, Akt-Thr308, and GSK-3beta) were apparent between the two populations. In conclusion, SV-SMC from T2DM patients differ from nondiabetic SV-SMC in that they exhibit a rhomboid phenotype and are more migratory, but less proliferative, in response to serum.
Madi
Haifa A
HA
Division of Cardiovascular and Neuronal Remodelling, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, Leeds LS2 9JT, United Kingdom.
Riches
Kirsten
K
Warburton
Philip
P
O'Regan
David J
DJ
Turner
Neil A
NA
Porter
Karen E
KE
D000328:Adult; D000368:Aged; D015153:Blotting, Western; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism* / Q000473:pathology*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000473:pathology; D032389:Myocytes, Smooth Muscle / Q000378:metabolism* / Q000473:pathology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins / Q000096:biosynthesis; D012501:Saphenous Vein / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction / Q000502:physiology
D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; C077591:S100A4 protein, human; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases