PKCδ inhibition normalizes the wound-healing capacity of diabetic human fibroblasts
PKCδ inhibition normalizes the wound-healing capacity of diabetic human fibroblasts
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DOI：
10.1172/jci82788
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发表时间：
2016-03-01
影响因子：
15.9
通讯作者：
King, George L.
中科院分区：
文献类型：
--
作者：
Khamaisi, Mogher;Katagiri, Sayaka;King, George L.
成纤维细胞功能异常是糖尿病患者伤口愈合不良的原因；然而，损害伤口愈合的机制尚不清楚。在这里，我们评估了患有 1 型糖尿病 (T1D) 50 年或以上的个体（奖牌获得者，n = 26）和年龄匹配的对照者（n = 7）的成纤维细胞。与对照组相比，Medalist 成纤维细胞对胰岛素的迁移反应减弱，VEGF 表达较低，磷酸化 (p-AKT) 激活较少，但 p-ERK 激活较少。获奖者成纤维细胞在裸鼠伤口闭合方面的功能也较差。奖章获得者死后成纤维细胞、活体 T1D 受试者的成纤维细胞、活体 T1D 受试者活动伤口的活检组织以及链脲佐菌素诱导的糖尿病小鼠的肉芽组织中，蛋白激酶 C δ 亚型 (PKC δ) 的激活增加。糖尿病诱导的 PKCD mRNA 表达与 mRNA 半衰期延长 2 倍相关。药物抑制和 siRNA 介导的 PKC δ 敲低或显性失活亚型的表达可在体外恢复 p-AKT 的胰岛素信号传导和 VEGF 表达，并改善体内伤口愈合。此外，对照成纤维细胞中 PKC δ 表达的增加产生了与 Medalist 成纤维细胞中所见相同的异常。我们的结果表明，糖尿病患者成纤维细胞中持续升高的 PKC δ 会抑制胰岛素信号传导和功能，从而损害伤口愈合，并表明 PKC δ 抑制是改善糖尿病患者伤口愈合的潜在疗法。
Abnormal fibroblast function underlies poor wound healing in patients with diabetes; however, the mechanisms that impair wound healing are poorly defined. Here, we evaluated fibroblasts from individuals who had type 1 diabetes (T1D) for 50 years or more (Medalists, n = 26) and from age-matched controls (n = 7). Compared with those from controls, Medalist fibroblasts demonstrated a reduced migration response to insulin, lower VEGF expression, and less phosphorylated (p-AKT), but not p-ERK, activation. Medalist fibroblasts were also functionally less effective at wound closure in nude mice. Activation of the delta isoform of protein kinase C (PKC delta) was increased in postmortem fibroblasts from Medalists, fibroblasts from living T1D subjects, biopsies of active wounds of living T1D subjects, and granulation tissues from mice with streptozotocin-induced diabetes. Diabetes-induced PKCD mRNA expression was related to a 2-fold increase in the mRNA half-life. Pharmacologic inhibition and siRNA-mediated knockdown of PKC delta or expression of a dominant-negative isoform restored insulin signaling of p-AKT and VEGF expression in vitro and improved wound healing in vivo. Additionally, increasing PKC delta expression in control fibroblasts produced the same abnormalities as those seen in Medalist fibroblasts. Our results indicate that persistent PKC delta elevation in fibroblasts from diabetic patients inhibits insulin signaling and function to impair wound healing and suggest PKC delta inhibition as a potential therapy to improve wound healing in diabetic patients.