Neointimal formation after endovascular arterial injury is markedly attenuated in db/db mice.

OBJECTIVE A diabetic mouse model of accelerated neointimal formation would be a useful tool to understand the increased incidence of restenosis in patients with diabetes. METHODS AND RESULTS Femoral artery endoluminal wire injury was performed in diabetic insulin 2 Akita (ins2Akita) and leptin receptor db/db (leprdb/db) mutant mice. Neointima size in ins2Akita mouse arteries was unchanged compared with nondiabetic wild-type littermates. Although Ki67 labeling demonstrated similar rates of replication in the neointima of leprdb/db mouse arteries, neointimal formation in leprdb/db mice was surprisingly reduced by approximately 90% compared with nondiabetic lepr+/+ mice. Four hours after arterial injury, medial smooth muscle cell death was diminished in leprdb/db arteries, suggesting that the initial response to arterial injury was altered in leprdb/db mice. CONCLUSIONS These studies highlight a differential response to arterial injury in leprdb/db mice and suggest a potential role for leptin in the regulation of neointimal formation in response to arterial injury.