Effects of Metabolic Disorders on Bone Marrow-Derived Cell Function

描述（由申请人提供）：糖尿病、肥胖和血脂异常在美国很流行，并且与中风、心肌梗死、周围血管疾病和足部溃疡的风险增加有关。因此，在这些疾病的治疗中，迫切需要更好的治疗方法来刺激血管生长。骨髓源性细胞（bmdc）正在被开发作为这一应用的治疗剂。不幸的是，糖尿病和代谢综合征会损害BMDCs，使其在最好的情况下适度促进血管生成，而在最坏的情况下则会抑制血管生成。因此，最大化BMDCs的治疗效果可能需要对BMDCs进行操作或辅助治疗。要做到这一点，需要了解BMDCs的分子作用机制，并确定调节其有效性的因素。在对健康小鼠和Leprdb小鼠（即患有代谢综合征的糖尿病小鼠）的研究中，我们发现了四种分子，肿瘤坏死因子α (TNF1)、白细胞介素12 （IL-12）、单核细胞趋化因子1 （MCP-1）和血管内皮生长因子A (VEGF-A)，它们具有共同的调节途径，似乎可以调节BMDC介导的血管生长。本研究将确定这些分子及其下游靶点在BMDC介导的组织血管化中的作用。我们的目的是确定BMDCs分泌TNF1、IL-12或MCP-1的能力是否降低；2)诱导TNF1、IL-12或MCP-1；或3)诱导TNF1、IL-12或MCP-1的下游靶标，限制它们促进毛细血管、小动脉或侧枝生长的能力。这些因素的缺失对BMDC诱导的血管生长的影响将在Leprdb小鼠和嵌合Leprdb小鼠的缺血性后肢和皮肤伤口模型中进行研究，这些小鼠的骨髓已被TNF1、IL-12或MCP-1敲除小鼠的细胞所取代。通过用来自健康、TNF1、IL-12或MCP-1敲除小鼠的BMDC治疗小鼠并进行拯救实验，我们将确定1)哪些研究因素对BMDC介导的生长至关重要，2)哪些因素可能作为BMDC治疗功能不良患者的辅助治疗。BMDCs已经在早期临床试验中使用，但是人们对为什么细胞疗法在一些病人身上成功而在另一些病人身上失败知之甚少。我们的最终目标是了解这种二分法，为选择可能从BMDC治疗中获益的患者提供更合理的依据，并确定可能的辅助治疗方法，以增强BMDC本身治疗效果甚微的患者的疗效。

DESCRIPTION (provided by applicant): Diabetes, obesity, and dyslipidemia are epidemic in the U.S. and are associated with increased risk for stroke, myocardial infarction, peripheral vascular disease, and foot ulcers. Thus, there is immense need for better therapies to stimulate vascular growth in the treatment of these conditions. Bone marrow-derived cells (BMDCs) are being developed as therapeutic agents in this application. Unfortunately diabetes and metabolic syndrome damage BMDCs rendering them at best modestly pro- and at worst, anti-angiogenic. So, maximization of the therapeutic efficacy of BMDCs may require manipulation of the BMDCs or adjunct therapies. To accomplish this requires an understanding of molecular mechanisms of action of BMDCs and identification of factors that modulate their effectiveness. In studies of healthy mice and Leprdb mice (i.e., diabetic mice with metabolic syndrome) we identified four molecules, tumor necrosis factor alpha (TNF1), interleukin 12 (IL-12), monocyte chemoattractant factor 1 (MCP-1), and vascular endothelial growth factor A (VEGF-A) that share a common regulatory pathway that appears to regulate BMDC mediated vascular growth. This study will define the role of these molecules and their downstream targets in BMDC mediated tissue vascularization. Our aims are to determine if a reduction in the ability of BMDCs to 1) secrete TNF1, IL-12, or MCP-1; 2) induce TNF1, IL-12, or MCP-1; or 3) induce downstream targets of TNF1, IL-12, or MCP-1 limits their capacity to promote growth of capillaries, arterioles, or collaterals. The effects of the loss of these factors on BMDC induced vascular growth will be studied in the ischemic hindlimb and skin wound models in Leprdb mice and chimeric Leprdb mice whose bone marrow has been replaced with cells from and TNF1, IL-12, or MCP-1 knockout mice. By treating mice with BMDCs from healthy, TNF1, IL-12, or MCP-1 knockout mice and performing rescue experiments we will identify 1) which of the studied factors are critical for BMDC mediated growth and 2) which might be used therapeutically as adjuncts to BMDC therapy in patients with poorly functioning BMDCs. BMDCs are already in use in early phase clinical trials, but there is little understanding of why cell therapy succeeds in some and fail in other patients. Our ultimate goals are to understand this dichotomy, to provide a more rational basis for selecting patients who are likely to benefit from BMDC therapy, and identify possible adjunct therapies to potentiate the effects of BMDCs in those whose own BMDCs provide little therapeutic benefit. PUBLIC HEALTH RELEVANCE: This work could lead to better treatment of heart attacks, strokes, and burns as well as prevention of chronic ulcers, particularly in people who are obese and those with diabetes.