Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine, University of Messina, Messina, Italy.
Surgery. 2011 Feb;149(2):253-61. doi: 10.1016/j.surg.2010.04.024. Epub 2010 Jun 8.
Cyclins drive cell-cycle progression by associating with their kinase partners, cyclin-dependent kinases (CDK). We investigated cyclin D1/CDK6, cyclin E/CDK2 complexes, and the cell-cycle negative regulators p15 and p27 in an incisional skin wound model.
Wounds were produced on the back of female diabetic mice and their normoglycemic littermates. Animals were treated with polydeoxyribonucleotide (PDRN, 8 mg/kg/i.p.), an agonist of adenosine A2(A) receptors, or its vehicle daily. Granulation tissue proliferation by Ki67 immunostaining, cyclin D/CDK6 and cyclin E/CDK2 complexes, and p21 and p16 proteins (Western blot analysis), and the histologic changes were assessed at different days (3, 6, and 12 days after injury).
Numerous Ki67 positive cells were observed at day 3 and day 6 in the granulation tissue of normoglycemic mice. Ki67 positive cells were fewer in diabetic than in normoglycemic mice. PDRN increased Ki67 positive cells in diabetic mice. Normoglycemic mice showed the greatest upregulation of cyclin D1, CDK6, cyclin E, and CDK2 at day 6. Diabetic mice had a markedly lower expression of cyclin D1, CDK6, cyclin E, and CDK2 at day 6. They also showed a greater expression of p15 and p27 at day 6. PDRN administration in diabetic mice increased cyclin D1/CDK6 and cyclin E/CDK2 expression and reduced p15 and p27 inhibitors at day 6 after injury; moreover, it improved the impaired wound healing at day 12.
Our results suggest that adenosine A2(A) receptor activation by PDRN might represent a therapeutic strategy to overcome the diabetes-impaired cell-cycle machinery.
细胞周期蛋白通过与激酶伴侣细胞周期蛋白依赖性激酶（CDK）结合来驱动细胞周期进程。我们在切口皮肤伤口模型中研究了细胞周期蛋白 D1/CDK6、细胞周期蛋白 E/CDK2 复合物以及细胞周期负调节剂 p15 和 p27。
在雌性糖尿病小鼠及其正常血糖的同窝仔鼠的背部制造伤口。动物每天接受聚脱氧核糖核苷酸（PDRN，8mg/kg/i.p.），一种腺苷 A2（A）受体激动剂或其载体治疗。通过 Ki67 免疫染色、细胞周期蛋白 D/CDK6 和细胞周期蛋白 E/CDK2 复合物以及 p21 和 p16 蛋白（Western blot 分析）评估肉芽组织增殖，并在不同时间（损伤后 3、6 和 12 天）评估组织学变化。
在正常血糖小鼠的肉芽组织中，第 3 天和第 6 天观察到大量 Ki67 阳性细胞。糖尿病小鼠中的 Ki67 阳性细胞少于正常血糖小鼠。PDRN 增加了糖尿病小鼠中的 Ki67 阳性细胞。正常血糖小鼠在第 6 天表现出细胞周期蛋白 D1、CDK6、细胞周期蛋白 E 和 CDK2 的最大上调。糖尿病小鼠在第 6 天表达的细胞周期蛋白 D1、CDK6、细胞周期蛋白 E 和 CDK2 明显较低。它们还在第 6 天表现出更高的 p15 和 p27 表达。在糖尿病小鼠中给予 PDRN 可增加细胞周期蛋白 D1/CDK6 和细胞周期蛋白 E/CDK2 的表达，并减少损伤后第 6 天的 p15 和 p27 抑制剂；此外，它改善了第 12 天受损的伤口愈合。
我们的结果表明，PDRN 激活腺苷 A2（A）受体可能代表一种克服糖尿病损伤细胞周期机制的治疗策略。
