Impact of TPO Treatment on Bone Healing and Angiogenesis in Type 2 Diabetes

TPO 治疗对 2 型糖尿病骨愈合和血管生成的影响

• 批准号: 9492356
• 负责人: Melissa A Kacena
• 金额: --
• 依托单位: RLR VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9492356
• 关键词: Adjuvant; Adverse effects; Affect; American; Angiogenic Factor; Autologous Transplantation; Binding; Biological; Biomechanics; Blood Cells; Blood Circulation; Blood Platelets; Blood Vessels; Blood capillaries; Bone Morphogenetic Proteins; Bone Regeneration; Bone Resorption; Bone Transplantation; Bone callus; Caring; Cell physiology; Cells; Chronic; Comprehensive Health Care; Data; Day Care; Defect; Diabetes Mellitus; Diabetic mouse; Diet; Disease; Endothelial Cells; Equilibrium; FDA approved; Family suidae; Fat-Restricted Diet; Femur; Fracture; Fracture Healing; Frequencies; Functional disorder; Generations; Glucose Intolerance; Goals; Gold; Growth Factor; Harvest; Healthcare Systems; Hematological Disease; Hematopoietic; High Fat Diet; Hip region structure; Histologic; Hyperglycemia; Hyperinsulinism; Impairment; In Vitro; Individual; Intervention; Knock-out; Link; Literature; MPL gene; Malignant Neoplasms; Measures; Mediating; Megakaryocytes; Mesenchymal; Microcirculation; Minerals; Mus; Non-Insulin-Dependent Diabetes Mellitus; Obesity; Operative Surgical Procedures; Orthopedics; Osteoblasts; Osteoclasts; Osteogenesis; Outcome; Overweight; Pain; Pathway interactions; Patients; Performance; Persons; Pharmacy facility; Physiological; Platelet Count measurement; Population; Property; Rattus; Regulatory Pathway; Research Personnel; Risk; Risk Factors; Role; Safety; Saline; Series; Site; Source; Surgeon; Techniques; Testing; Therapeutic Effect; Thrombopoietin; Time; Torque; Torsion; Treatment Efficacy; Veterans; Work; Wound Healing; angiogenesis; base; bone; bone healing; bone morphogenetic protein 2; cost; diabetes control; diabetic; diabetic patient; experimental group; healing; hospital bed; improved; microCT; mimetics; mouse model; non-diabetic; novel therapeutics; regenerative; scaffold; statistics; vasculogenesis

Currently, 1 in 4 veterans receiving VA care is diabetic, and over 70% are overweight or obese and at risk of developing diabetes. Diabetes is a risk factor for impaired fracture healing and numerous studies have demonstrated increased frequency of non-union, partial union, or delayed union in diabetic patients as compared to non-diabetic patients. Diabetic patients have impaired microcirculation which is partially responsible for these fracture complications. In the case of non-union, additional interventions are required such as bone grafting techniques. The gold standard for grafting to achieve bone union is the use of autograft from the patient's hip, which may not always achieve healing. Additionally, the harvest of bone often leaves patients with a painful donor site that may not resolve. Therefore, orthopaedic surgeons desire a biologic enhancement for bone healing that does not require the harvesting of iliac crest bone. Local placement of bone morphogenetic proteins (BMPs) is the only FDA approved biological option capable of healing non-unions. BMPs, although potent in promoting bone regeneration, have been associated with several side effects, including a link with cancer. Therefore, there is a great need for new therapies that heal bone with improved safety profiles. Recently, we found that thrombopoietin [TPO, a megakaryocyte (MK) growth factor] could heal critical-sized bone defects in mice, rats and pigs, as well as, if not better than, BMP-2. The long-term goal of this work is to determine whether thrombopoietic agents could serve as novel therapies for bone healing. Our studies as well as the literature show that TPO increases pathways associated with angiogenesis, increases hematopoietic cell populations, including osteoclasts (OCs) and MKs, and increases osteoblasts (OBs) and bone formation, the latter is indirectly through MK-mediated OB proliferation. Based on these ideas, we hypothesize that TPO accelerates bone healing in type 2 diabetes (T2D) by stimulating angiogenesis which has the direct benefit of delivering mesenchymal and hematopoietic cells that mediate wound healing. In Aim 1, we will assess the therapeutic effects of TPO on bone healing in diet-induced obesity with hyperglycemia, hyperinsulinemia, and glucose intolerance (T2D). Mice on a C57BL/6 background will be fed a low fat diet (LFD) or a high fat diet (HFD), will undergo a segmental bone defect surgery, will be treated with saline (negative control), BMP-2 (positive control), or TPO (experimental group), and bone healing assessed. In Aim 2, we will demonstrate the role of TPO in stimulating angiogenesis/vasculogenesis. This will be accomplished by characterizing angiogenesis/vasculogenesis in mice from Aim 1, as well as in mice in which the TPO receptor has been selectively knocked out of endothelial cells (ECs). We will also conduct a series of in vitro studies to assess the impact of TPO treatment as well as secreted factors from MKs on EC function to begin dissecting the mechanisms responsible. Successful accomplishment of these Aims will demonstrate the utility of using TPO for improving bone healing in diabetic patients. This project has high translational potential as thrombopoietic agents are currently FDA approved for treatment of low platelet numbers. Therefore, the regulatory pathway for obtaining FDA approval for a new indication, fracture healing, is easier than it would be for a compound or biologic which has never been used in patients. Finally, demonstrating the mechanism by which TPO stimulates angiogenesis will be important for determining whether other downstream targets should also be evaluated for therapeutic efficacy.

目前，接受VA护理的四分之一的退伍军人患有糖尿病患者，超过70％的超重或肥胖，在 患糖尿病的风险。糖尿病是骨折愈合受损的危险因素，许多研究已经 证明糖尿病患者的非工会，部分联合或延迟联合的频率增加 与非糖尿病患者相比。糖尿病患者的微循环受损，部分是 负责这些骨折并发症。在非工会的情况下，需要其他干预措施 例如骨移植技术。 嫁接实现骨结合的金标准是使用患者臀部的自体移植 可能并不总是实现治愈。此外，骨骼的收获经常使患者患有痛苦的供体 可能无法解决的站点。因此，骨科医生希望对骨骼愈合的生物学增强 这不需要收获iLiac Crest骨。骨形态发生蛋白的局部放置 （BMP）是FDA唯一能够治愈非工会的生物学选择。 BMP，尽管有效 促进骨骼再生与多种副作用有关，包括与癌症的联系。 因此，非常需要新疗法，可以通过改善的安全概况来治愈骨骼。最近，我们 发现血小子蛋白[TPO，一种巨核细胞（MK）生长因子]可以治愈关键尺寸的骨缺损 小鼠，大鼠和猪，以及（即使不是比BMP-2）。这项工作的长期目标是确定 血小板剂是否可以作为骨骼愈合的新疗法。 我们的研究以及文献表明，TPO增加了与血管生成相关的途径， 增加造血细胞群体，包括破骨细胞（OC）和MK，并增加成骨细胞 （OBS）和骨形成，后者是通过MK介导的OB增殖而间接的。基于这些想法， 我们假设TPO通过刺激血管生成加速了2型糖尿病（T2D）的骨骼愈合 具有介导伤口愈合的间充质和造血细胞的直接好处。 在AIM 1中，我们将评估TPO对饮食引起的肥胖症骨骼愈合的治疗作用 高血糖，高胰岛素血症和葡萄糖不耐症（T2D）。 C57BL/6背景上的小鼠将被喂食 低脂饮食（LFD）或高脂肪饮食（HFD）将接受节骨缺损手术，将接受治疗 评估了盐水（阴性对照），BMP-2（阳性对照）或TPO（实验组）和骨愈合。 在AIM 2中，我们将展示TPO在刺激血管生成/血管生成中的作用。这将是 通过表征来自AIM 1的小鼠的血管生成/血管生成，以及在其中的小鼠中完成 TPO受体已被选择性地从内皮细胞（EC）中淘汰。我们还将进行一系列 体外研究评估TPO治疗的影响以及MKS对EC功能的分泌因素 开始解剖负责的机制。 成功实现这些目标将证明使用TPO改善骨骼的实用性 糖尿病患者的愈合。该项目具有很高的翻译潜力，因为目前是血小板代理商 FDA批准治疗低血小板数。因此，获得FDA的调节途径 批准新的指示，即骨折愈合，比具有具有的化合物或生物学要容易 从未在患者中使用。最后，证明TPO刺激血管生成的机制将 对于确定是否还应评估其他下游目标的治疗目标很重要 功效。