Mechanisms of Neuropeptides Action in Diabetes

描述（由申请方提供）：周围神经病变在糖尿病足溃疡（DFU）的发生中起主要作用，因为疼痛不敏感性导致组织损伤延长，直至形成慢性伤口。然而，我们单位和其他地方最近的研究表明，神经病相关的缺乏局部分泌的神经肽的C-伤害性纤维损害伤口愈合，这可能是导致慢性DFU的发展，可能需要截肢的主要原因。在本申请中，我们计划鉴定神经病相关的神经肽缺乏和慢性炎症导致伤口愈合失败的机制。我们的主要假设是，与糖尿病诱导的促炎状态相关的神经肽的缺乏导致蛋白酪氨酸磷酸酶1B（PTP 1B）的表达和活性增加，从而导致生长因子信号传导减少、成纤维细胞功能降低和伤口愈合受损。此外，我们假设糖尿病诱导的PTP 1B表达和神经病变相关的神经肽缺乏导致肥大细胞功能受损，导致各种细胞因子和血管生成因子分泌不足，从而减少血管生成并进一步损害伤口愈合。最后，我们假设在糖尿病动物模型中抑制PTP 1B和肥大细胞稳定将改善伤口愈合，并导致新的治疗方法的发展。为了探讨我们的假设，我们提出了一个前瞻性队列随访研究糖尿病患者的神经病变的严重程度和神经肽表达之间的关系，以PTP 1B前足和前臂皮肤表达/活性和肥大细胞数量和激活。我们还将研究PTP 1B，肥大细胞和细胞因子和生长因子的变化与伤口愈合障碍之间的关系。我们还建议进行动物研究，以检查影响这些机制的干预措施是否会影响伤口愈合的进展，并可能导致新的治疗方法的发展。该提案有三个具体目标：（1）。探索与糖尿病诱导的促炎状态相关的神经肽缺乏导致PTP 1B表达/活性增加和肥大细胞功能障碍与伤口愈合受损相关的假设; 2.）研究PTP 1B抑制是否可以改善糖尿病患者的伤口愈合; 3.）研究神经肽缺乏是否导致肥大细胞功能障碍，并有助于糖尿病伤口愈合障碍。该应用程序将包括来自Joslin-Beth以色列女执事足部中心，血管外科和内分泌学以及塔夫茨医疗中心分子免疫药理学和药物发现实验室的研究人员的合作。各个学科之间的合作创造了非常强大的协同作用，将产生新颖的和临床有用的数据，并有可能在当前的思维中创造一个范式转变，导致可以转化为新的治疗方法的开创性发现。 公共卫生相关性：周围神经病变目前被认为在糖尿病足溃疡（DFU）的发展中起主要作用，因为疼痛不敏感性导致长期组织损伤，直至形成慢性伤口。然而，我们单位和其他地方最近的研究表明，神经病相关的缺乏局部分泌的神经肽的C-伤害性纤维损害伤口愈合，这可能是导致慢性DFU的发展，可能需要截肢的主要原因。在本申请中，我们计划鉴定神经病相关的神经肽缺乏和慢性炎症导致伤口愈合失败的机制

DESCRIPTION (provided by applicant): Peripheral neuropathy plays a major role in the development of diabetic foot ulceration (DFU) because of the pain insensitivity that allows prolonged tissue injury till a chronic wound has been developed. However, recent studies by our unit and elsewhere indicate that the neuropathy-associated lack of locally secreted neuropeptides by the C-nociceptive fibers impair wound healing and this may be of the major reasons that lead to the development of chronic DFU that may necessitate amputation. In the present application we plan to identify the mechanisms through which, the neuropathy-associated lack of neuropeptides and chronic inflammation lead to wound healing failure. Our primary hypothesis is that the lack of neuropeptides in association with the diabetes-induced pro-inflammatory state lead to increased expression and activity of protein tyrosine phosphatase 1B (PTP1B) causing reduced growth factor signaling, reduced fibroblast function and impaired wound healing. In addition, we hypothesize that diabetes-induced PTP1B expression and the neuropathy-related neuropeptide deficiency leads to impaired mast cell function results in deficient secretion of various cytokines and angiogenic factors that reduces angiogenesis and further impairs wound healing. We finally hypothesize that inhibition of PTP1B and mast cell stabilization in diabetic animal models will improve wound healing and lead to the development of new therapeutic approaches. In order to explore our hypothesis, we propose a prospective cohort follow up study in diabetic patients to study the relationship between the severity of neuropathy and neuropeptides expression to PTP1B forefoot and forearm skin expression/activity and mast cell number and activation. We will also examine the association between PTP1B, mast cells and changes in cytokines and growth factors to wound healing impairment. We also propose animal studies that will examine whether interventions that affect these mechanisms can affect the progress of wound healing and can lead to the development of new therapeutic approaches. The proposal has three specific aims: 1.) To explore the hypothesis that the deficiency of neuropeptides in association with the diabetes-induced pro-inflammatory state lead to increased PTP1B expression/activity and mast cell dysfunction are associated with impaired wound healing; 2.) To investigate whether PTP1B inhibition can improve wound healing in diabetes; 3.) To examine whether neuropeptide deficiency causes mast cell dysfunction and contributes to wound healing impairment in diabetes. The application will encompass the collaboration of investigators from the Joslin-Beth Israel Deaconess Foot Center, Vascular Surgery and Endocrinology and the Molecular Immunopharmacology and Drug Discovery Lab at Tufts Medical Center. The collaboration among the various disciplines creates very strong synergy and will lead to novel and clinically useful data and has the potential to create a paradigm shift in the current thinking, lead to seminal discoveries that can be translated to new therapeutic approaches. PUBLIC HEALTH RELEVANCE: Peripheral neuropathy is currently considered to play a major role in the development of diabetic foot ulceration (DFU) because of the pain insensitivity that allows prolonged tissue injury till a chronic wound has been developed. However, recent studies by our unit and elsewhere indicate that the neuropathy-associated lack of locally secreted neuropeptides by the C-nociceptive fibers impair wound healing and this may be of the major reasons that lead to the development of chronic DFU that may necessitate amputation. In the present application we plan to identify the mechanisms through which, the neuropathy-associated lack of neuropeptides and chronic inflammation lead to wound healing failure