Notch signaling in diabetic wounds

糖尿病伤口中的Notch信号传导

• 批准号: 10604339
• 负责人: Katherine Ann Gallagher
• 金额: $ 62.24万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10604339
• 关键词: Amputation; Antibodies; Artificial nanoparticles; Blood specimen; CD4 Positive T Lymphocytes; Cells; Chronic; Data; Defect; Dermal; Diabetes Mellitus; Ensure; Enzymes; Epigenetic Process; Failure; Fibroblasts; Functional disorder; Gene Expression; Genetic; Homeostasis; Human; IL17 gene; Immune; Immune response; Impaired healing; Impaired wound healing; Impairment; Inflammation; Inflammatory; Inflammatory Response; Injury; Ligands; Local Therapy; MLL gene; Macrophage; Malignant Neoplasms; Mediating; Methods; Molecular; Morbidity - disease rate; Mus; Non-Insulin-Dependent Diabetes Mellitus; Normal tissue morphology; Pathologic; Pathway interactions; Patients; Phenotype; Play; Publishing; Receptor Activation; Receptor Signaling; Regulation; Regulatory T-Lymphocyte; Role; Signal Transduction; T cell differentiation; T-Cell Activation; T-Lymphocyte; TLR4 gene; Testing; Therapeutic; Tissue Sample; Tissues; cellular targeting; diabetic; diabetic ulcer; diabetic wound healing; diet-induced obesity; dietary; experimental study; healing; histone methyltransferase; improved; inhibitor; inhibitor therapy; keratinocyte; mortality; mouse model; nanotherapy; non-diabetic; non-healing wounds; notch protein; novel; pharmacologic; prevent; receptor; receptor expression; response; skin wound; targeted treatment; therapeutic target; tissue repair; wound; wound healing

PROJECT SUMMARY/ABSTRACT Non-healing wounds in patients with Type 2 Diabetes (T2D) are a major cause of increasing morbidity and mortality. 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. We have utilized both genetic (db/db) and dietary (diet- induced obese) murine models of T2D as well as human wound tissue and blood samples collected from T2D patients to explore mechanisms of impaired wound healing. Our published and preliminary data demonstrate that interactions between wound macrophages (Mφs), and CD4+T cells, via Notch signaling, dictate CD4+T cell activation to ultimately regulate inflammation and healing in wounds. We and others have identified that a wound CD4+Treg cell phenotype is critical for normal tissue repair, while a TH17 phenotype promotes excess inflammation and impairs healing. Our preliminary data identify TLR4 signaling in wound Mφs upregulates the Notch ligand, DLL4, which then interacts with the Notch 1 and 2 receptors on CD4+T cells to promote TH17 as opposed to Treg differentiation. These interactions drive excess inflammation and pathologic healing in diabetes. Additionally, the DLL4-Notch pathway may be further upregulated in diabetic wounds via epigenetic mechanisms involving MLL1, a histone methyltransferase. MLL1 directly upregulates DLL4 in Mφs and can indirectly increase DLL4 via TLR4 signaling in Mφs. In addition, MLL1 can directly increase Notch 1 and 2 receptor expression in CD4+T cells, making them more receptive to Notch activation and promoting a prolonged TH17 response. These changes then dictate the pathologic TH17 phenotype in diabetic wounds. These results have led to our hypothesis that DLL4-mediated Notch receptor signaling in diabetic wounds polarizes CD4+T cells in the wound towards TH17 and promotes chronic inflammation and non-healing. Further, increased downstream IL17A signaling increases epidermal and dermal cell mediated inflammation in diabetic tissue. Our data suggest that wound Mφ/CD4+T cell wound phenotypes may be restored via Mφ-targeted treatment (delivered locally to the wound via engineered nanoparticles) with MLL1 inhibitor(s) or local treatment with anti-DLL4 antibodies. To test our hypotheses, we will pursue the following aims: Aim 1: To examine the direct (MLL1) and indirect (TLR4/MyD88) regulation of DLL4 in wound macrophages during normal and diabetic conditions. Aim 2: To identify the role of Notch receptor activation on Treg/TH17 differentiation during normal and diabetic wound repair. Aim 3: To compare local and Mφ-targeted therapies to reduce Notch signaling, limit TH17 differentiation, improve healing and identify the cellular targets for IL17A signaling in wounds.

项目摘要/摘要 2型糖尿病患者（T2D）患者的非愈合伤口是发病率增加和 死亡。 T2D患者伤口愈合的失败是美国截肢的最常见原因 5年死亡率接近50％。那是了解伤口愈合的批判性需求 T2D缺陷以开发目标疗法。我们同时使用了遗传（DB/DB）和饮食（饮食 - 诱导T2D的肥胖）模型以及人类伤口组织和从T2D收集的血液样本 患者探索伤口愈合受损的机制。我们发布的初步数据表明 宽巨噬细胞（MφS）和CD4+T细胞之间的相互作用通过缺口信号传导决定CD4+T细胞 激活最终调节伤口的炎症和愈合。我们和其他人已经确定了伤口 CD4+Treg细胞表型对于正常组织修复至关重要，而Th17表型促进 炎症并损害愈合。我们的初步数据识别伤口中的TLR4信号传导上调 Notch配体DLL4，然后与CD4+T细胞上的Notch 1和2受体相互作用，以促进Th17作为 反对特雷格的分化。这些相互作用驱动糖尿病中的感染和病理愈合。 此外，DLL4-核路途径可以通过表观遗传机制在糖尿病伤口中进一步更新 涉及MLL1，一种组蛋白甲基转移酶。 MLL1直接上调MφS中的DLL4，并间接增加 DLL4通过MφS中的TLR4信号传导。另外，MLL1可以直接增加Notch 1和2的受体表达 CD4+T细胞，使它们更容易接受Notch激活并促进长时间的Th17响应。这些 然后，变化决定了糖尿病伤口中的病理Th17表型。这些结果导致了我们 糖尿病伤口中DLL4介导的Notch受体信号传导的假设使伤口中的CD4+T细胞极化 此外，下游IL17A增加 信号传导增加了糖尿病组织中表皮和皮肤细胞介导的注射。我们的数据表明 伤口Mφ/CD4+T细胞世界表型可以通过靶向Mφ的治疗来恢复（局部交付到 用MLL1抑制剂或抗DLL4抗体的局部治疗通过工程纳米颗粒的伤口）。测试 我们的假设，我们将追求以下目的：目标1：检查直接（MLL1）和间接 （TLR4/MYD88）在正常和糖尿病条件下伤口巨噬细胞中DLL4的调节。目标2： 确定Notch受体激活在正常和糖尿病期间的Treg/Th17分化的作用 伤口修复。目标3：要比较局部和Mφ靶向疗法以减少Notch信号，请限制TH17 分化，改善愈合并确定伤口中IL17A信号传导的细胞靶标。