TNF-ALPHA AND BMP2-WNT SIGNALING IN DIABETIC VASCULAR DISEASE

描述（由申请人提供）：西方社会正在经历II型糖尿病（T2 DM）的流行，与生活方式、肥胖和长寿有关。T2 DM是一种全身性血管疾病;广泛的低度动脉炎症、升高的TNF-α水平和氧化应激破坏大血管（例如，心脏、主动脉）和微血管（例如视网膜、肾小球）功能。T2 DM的一个高度特征是中动脉钙化（MAC）。MAC的股动脉顺应性降低的负面后果已经出现; MAC扰乱正常的Windkessel生理，导致收缩和舒张功能障碍，增加死亡率和截肢风险。预防或治疗MAC的能力代表了未满足的临床需求。更好地了解糖尿病和肾脏疾病（CKD）如何促进MAC将为设计新的策略以减少血管钙负荷，保持主动脉顺应性和改善血管功能提供有用的见解。最近的数据已经确定了糖尿病MAC中激活的主动脉BMP 2-Msx 2-Wnt信号传导-所有这些都被英夫利昔单抗抑制。该项目的主要目标是评估这些信号如何改善主动脉钙化，结构和顺应性。目标1：“为了测试用TNF-α拮抗剂英夫利西单抗或水杨酸盐抑制动脉BMP 2- Wnt诱导是否能改善糖尿病血管疾病的主动脉顺应性。“通过使用离体视频体积描记术评估主动脉压力-直径关系，我们将在相关的T2 DM模型-TOPGAL+; LDLR-/-小鼠喂养的致糖尿病高脂饮食（HFD）中建立TNF-α和主动脉钙积累、Wnt信号传导和僵硬之间的关系。将与RANKL抑制剂OPG的反应进行比较。目标二：“为了表征TNF-α通过NADPH氧化酶信号传导促进主动脉外膜肌成纤维细胞Msx 2基因转录的机制。“NAPDH氧化酶抑制剂apocynin抑制TNF-α（转录介导）对Msx 2的诱导。通过识别响应于TNF-α的传递Msx 2诱导的信号级联，可以设计新的策略来抑制血管钙化。目标3：“使用p47 phox- /-; TOPGAL+; LDLR-/-小鼠作为模型，确定T2 DM中诱导主动脉BMP 2-Msx-2-Wnt级联是否需要NADPH氧化酶信号传导。“通过对p47 phox-/-; TOPGAL+; LDLR-/-和p47 phox +/-;TOPGAL+; LDLR-/-对照进行表型分析，我们评估了这种TNF调节的氧化还原途径是否有助于HFD激活主动脉BMP 2-Msx 2-Wnt。

DESCRIPTION (provided by applicant): Westernized societies are experiencing an epidemic of type II diabetes (T2DM), related to life-style, obesity, and longevity. T2DM is a systemic vascular disorder; wide-spread low grade arterial inflammation, elevated TNF-alpha levels, & oxidative stresses disrupt macrovascular (e.g., heart, aorta) & microvascular (e.g. retina, renal glomerulus) functions. A highly characteristic feature of T2DM is medial artery calcification (MAC). The negative consequences of reduced aortofemoral compliance of MAC have emerged; MAC perturbs normal Windkessel physiology, causing systolic & diastolic dysfunction that increases mortality & amputation risk. The ability to prevent or treat MAC represents an unmet clinical need. A better understanding of how diabetes and kidney disease (CKD) promote MAC will provide insights useful for devising new strategies to reduce vascular calcium load, preserve aortic compliance, & improve vascular function. Recent data have identified activated aortic BMP2-Msx2-Wnt signaling in diabetic MAC--all inhibited by infliximab. The chief goal of this project is to assess how targeting these signals can improve aortic calcification, structure, & compliance. Aim 1: "To test whether inhibition of arterial BMP2- Wnt induction with theTNF-alpha antagonist infliximab or salicylate improves aortic compliance in diabetic vascular disease." By assessing aortic pressure- diameter relationships using ex vivo video plethysmography, we will establish the relationships between TNF-alpha & aortic calcium accumulation, Wnt signaling, and stiffness in a relevant T2DM model--the TOPGAL+; LDLR-/- mouse fed diabetogenic high fat diets (HFD). Comparison will be made with responses to the RANKL inhibitor, OPG. Aim 2: "To characterize the mechanisms whereby TNF- alpha signaling via NADPH oxidase promotes Msx2 gene transcription in aortic adventitial myofibroblasts." The NAPDH oxidase inhibitor, apocynin, inhibits Msx2 induction by TNF-alpha (transcriptionally mediated). By identifying the signaling cascades conveying Msx2 induction in response to TNF-alpha, novel strategies can be devised to inhibit vascular calcification. Aim 3: "To identify if NADPH oxidase signaling is required for induction of aortic BMP2-Msx-2-Wnt cascades in T2DM, using p47phox- /-; TOPGAL+; LDLR-/- mice as a model." By phenotyping p47phox-/-; TOPGAL+; LDLR-/- and p47phox+/-;TOPGAL+; LDLR-/- controls, we assess whether this TNF- regulated redox pathway contributes to aortic BMP2-Msx2-Wnt activation by HFD.