Targeted therapy to reverse TLR4/DLL4 dysregulation in diabetic wounds

项目总结/摘要 2型糖尿病（T2 D）患者的不愈合伤口是发病率和死亡率的主要原因， 以惊人的速度增长。2型糖尿病患者伤口愈合失败是最常见的原因， 在美国，截肢的5年死亡率接近50%。因此，迫切需要了解 T2 D的伤口愈合缺陷，以开发靶向治疗。从我们实验室公布的数据和我的新 初步数据已经确定糖尿病伤口巨噬细胞中的TLR 4信号传导上调Notch配体， DLL 4，并促进急性伤口的炎症。此外，在糖尿病伤口巨噬细胞中，TLR 4/DLL 4 途径上调继发于表观遗传机制，从而增加MLL 1，组蛋白 Tlr 4启动子上的甲基转移酶促进增加的TLR 4信号传导。这增加了TLR 4信号传导（通过 MyD 88）上调糖尿病伤口Mφ中的DLL 4并驱动糖尿病中的炎症和病理愈合。 我们提出的研究将确定TLR 4通过MLL 1介导的机制在表观遗传学上上调。 糖尿病伤口巨噬细胞和直接调节DLL 4表达。这些结果导致了我们的假设 糖尿病伤口巨噬细胞中增加的TLR 4信号传导增加了DLL 4， 糖尿病伤口的炎症和不愈合。我们的数据表明，糖尿病伤口修复可能会得到改善， 通过用TLR 4抑制剂和/或MLL 1抑制剂局部靶向治疗。为了验证我们的假设，我们将 目的1：研究糖尿病创面中DLL 4的TLR 4依赖性调节 急性和慢性糖尿病小鼠伤口模型中的巨噬细胞。目标2：确定当地 TLR 4或MLL 1的治疗性阻断改善急性和慢性小鼠中的糖尿病伤口修复 伤口模型

PROJECT SUMMARY/ABSTRACT Non-healing wounds in patients with Type 2 Diabetes (T2D) are a major cause of morbidity and mortality and are increasing at an alarming rate. Failure of wound healing in T2D patients represents the most common cause of amputation in the US with a 5-year mortality rate of nearly 50%. Thus, a critical need exists for understanding the wound healing defects in T2D in order to develop targeted therapies. Published data from our lab and my new preliminary data has identified that TLR4 signaling in diabetic wound macrophages upregulates the Notch ligand, DLL4, and promotes inflammation in acute wounds. Further, in diabetic wound macrophages, the TLR4/DLL4 pathway is upregulated secondary to an epigenetic mechanism whereby increased MLL1, a histone methyltransferase, on the Tlr4 promoter promotes increased TLR4 signaling. This increased TLR4 signaling (via MyD88) upregulates DLL4 in diabetic wound Mφs and drives inflammation and pathologic healing in diabetes. Our proposed studies will establish that TLR4 is epigenetically upregulated via an MLL1-mediated mechanism in diabetic wound macrophages and directly regulates DLL4 expression. These results have led to our hypothesis that increased TLR4 signaling in diabetic wound macrophages increases DLL4 which promotes chronic inflammation and non-healing in diabetic wounds. Our data suggest that diabetic wound repair may be improved via locally-targeted treatment with TLR4 inhibitor(s) and/or MLL1 inhibitor(s). To test our hypotheses, we will pursue the following Aims: Aim 1: To examine the TLR4-dependent regulation of DLL4 in diabetic wound macrophages in acute and chronic diabetic murine wound models. Aim 2: To determine if local therapeutic blockade of TLR4 or MLL1 improves diabetic wound repair in acute and chronic murine wound models.