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流行，并与卒中、心肌梗死、外周血管疾病和足部溃疡的风险增加相关。因此，在这些病症的治疗中，非常需要更好的疗法来刺激血管生长。骨髓来源的细胞（BMDC）正在被开发为该应用中的治疗剂。不幸的是，糖尿病和代谢综合征损害BMDC，使它们在最好的情况下适度地促进血管生成，在最坏的情况下，抗血管生成。因此，BMDC的治疗功效的最大化可能需要对BMDC或辅助疗法的操作。要做到这一点，需要了解BMDC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）中，我们鉴定了四种分子，肿瘤坏死因子α（TNF 1）、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），它们共享似乎调节BMDC介导的血管生长的共同调节途径。本研究将明确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BMDC 1）分泌TNF 1、IL-12或MCP-1; 2）诱导TNF 1、IL-12或MCP-1;或3）诱导TNF 1、IL-12或MCP-1的下游靶点的能力的降低是否限制了它们促进毛细血管、小动脉或侧支生长的能力。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研究这些因子的丧失对BMDC诱导的血管生长的影响，所述嵌合Leprdb小鼠的骨髓已被来自TNF 1、IL-12或MCP-1敲除小鼠的细胞替代。通过用来自健康、TNF 1、IL-12或MCP-1敲除小鼠的BMDC治疗小鼠并进行拯救实验，我们将鉴定1）哪些所研究的因子对于BMDC介导的生长是关键的，以及2）哪些可以在治疗上用作BMDC治疗功能不良的患者的替代物。BMDCs已经在早期临床试验中使用，但人们对为什么细胞疗法在一些患者中成功而在其他患者中失败的原因知之甚少。我们的最终目标是理解这种二分法，为选择可能从BMDC治疗中获益的患者提供更合理的基础，并确定可能的辅助治疗，以增强BMDC在自身BMDC治疗获益甚微的患者中的作用。 公共卫生相关性：这项工作可能会导致更好地治疗心脏病发作，中风和烧伤以及预防慢性溃疡，特别是在肥胖和糖尿病患者中。

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.