Rosiglitazone attenuates atherosclerosis in a model of insulin insufficiency independent of its metabolic effects.
OBJECTIVE
Recent studies have demonstrated a role for thiazolidinediones in attenuating atherosclerosis. However, these studies were performed in insulin-resistant animal models in association with reductions in insulin and glucose levels. To assess the vascular effects of thiazolidinediones, independent of their metabolic effects, we observed the effect of rosiglitazone on diabetes-associated atherosclerosis in a model of insulin insufficiency.


RESULTS
Control and diabetic apolipoprotein E-deficient mice received rosiglitazone or placebo. Diabetic mice demonstrated a 3-fold increase in plaque area, which was attenuated by rosiglitazone. There was no significant difference in glucose, insulin, or cholesterol levels between treated and untreated diabetic animals. Rosiglitazone attenuated the increase in superoxide production observed in diabetic mice. A 4-fold increase in the reverse cholesterol transport marker ABCA1 was observed in treated diabetic mice. Rosiglitazone reduced angiotensin II receptor gene expression in control and diabetic mice, and macrophage accumulation was increased in diabetic mice compared with controls and was attenuated by rosiglitazone.


CONCLUSIONS
These findings suggest peroxisome proliferator-activated receptor-gamma ligands such as rosiglitazone confer vascular protection independent of their effects on metabolic control. These antiatherosclerotic effects may have important clinical ramifications not only in insulin resistance/type 2 diabetes and also in type 1 diabetes.
Calkin
Anna C
AC
JDRF Danielle Alberti Centre for Diabetes Complications, Vascular Division, Wynn Domain, Baker Heart Research Institute, Melbourne 8008, Australia. anna.calkin@baker.edu.au
Forbes
Josephine M
JM
Smith
Craig M
CM
Lassila
Markus
M
Cooper
Mark E
ME
Jandeleit-Dahm
Karin A
KA
Allen
Terri J
TJ
D000818:Animals; D001057:Apolipoproteins E / Q000235:genetics; D050197:Atherosclerosis / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism*; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000150:complications / Q000188:drug therapy; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000188:drug therapy; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy; D004195:Disease Models, Animal; D006442:Glycated Hemoglobin / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000097:blood / Q000172:deficiency*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D018384:Oxidative Stress; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology*; D014280:Triglycerides / Q000097:blood; D014657:Vasculitis / Q000150:complications / Q000188:drug therapy / Q000378:metabolism
D001057:Apolipoproteins E; D001786:Blood Glucose; D002784:Cholesterol; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin; D000077154:Rosiglitazone; D045162:Thiazolidinediones; D014280:Triglycerides