Nitric oxide differentially affects proteasome activator 28 after arterial injury in type 1 and type 2 diabetic rats

作者：Tsihlis Nick D; Rodriguez Monica P; Jiang Qun; Schwartz Amanda; Flynn Megan E; Vercammen Janet M; Kibbe Melina R^*

来源：Journal of Surgical Research, 2016, 202(2): 413-421.

DOI：10.1016/j.jss.2016.01.030

• Proteasome
• Diabetes
• Nitric oxide
• Neointimal hyperplasia

Background: Diabetic patients display aggressive restenosis after vascular interventions, likely because of proproliferative influences of hyperglycemia and hyperinsulinemia. We have shown that nitric oxide (NO) inhibits neointimal hyperplasia in type 2, but not in type 1, diabetic rats. Here, we examined proteasome activator 28 (PA28) after arterial injury in different diabetic environments, with or without NO. We hypothesize that NO differentially affects PA28 levels based on metabolic environment.
Materials and methods: Vascular smooth muscle cell (VSMC) lysates from male, nondiabetic Lean Zucker (LZ) and Zucker Diabetic Fatty (ZDF) ratswere assayed for 26S proteasome activity with or without PA28 and S-nitroso-N-acetylpenicillamine. LZ and ZDF VSMCs were treated with (Z)-1-[ N-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1,2-diolate for 24 h. Balloon-injured carotid arteries from LZ, streptozotocin-injected LZ (STZ, type 1), and ZDF (type 2) rats treated with disodium 1-[2-(carboxylato) pyrrolidin-1-iyl] diazen-1-ium-1,2-diolate were harvested at 3 or 14 d. PA28 alpha was assessed by Western blotting and immunofluorescent staining.
Results: S-nitroso-N-acetylpenicillamine reversed PA28-stimulated increases in 26S proteasome activity in LZ and ZDF VSMCs. Increased (Z)-1-[ N-(2-aminoethyl)-N-(2-ammonioethyl) amino] diazen-1-ium-1,2-diolate lowered PA28 alpha in LZ VSMCs but increased PA28 alpha in ZDF VSMCs. At 3 d after injury, disodium 1-[ 2-(carboxylato) pyrrolidin-1-iyl] diazen-1-ium-1,2-diolate potentiated injury-induced PA28 alpha decreases in LZ, STZ, and ZDF rats, suggesting VSMCs, depleted at this early time point, are major sources of PA28 alpha. At 14 d after injury, total PA28a staining returned to baseline. However, although intimal and medial PA28 alpha staining increased in injured STZ rats, adventitial PA28 alpha staining increased in injured ZDF rats.
Conclusions: PA28 dysregulation may explain the differential ability of NO to inhibit neointimal hyperplasia in type 1 versus type 2 diabetes. Published by Elsevier Inc.

• 出版日期2016-5-15
• 单位西北大学