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

描述（由申请人提供）：西方化社会正经历着2型糖尿病（T2DM）的流行，与生活方式、肥胖和寿命有关。T2DM是一种全身性血管疾病；广泛的低级别动脉炎症、tnf - α水平升高和氧化应激破坏大血管（如心脏、主动脉）和微血管（如视网膜、肾小球）功能。T2DM的一个高度特征性特征是内侧动脉钙化（MAC）。MAC降低主动脉股动脉顺应性的负面后果已经出现；MAC扰乱正常的血管生理，引起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的能力是尚未满足的临床需求。更好地了解糖尿病和肾脏疾病（CKD）如何促进MAC，将为设计减少血管钙负荷、保持主动脉顺应性和改善血管功能的新策略提供有用的见解。最近的数据表明，糖尿病MAC中激活的主动脉BMP2-Msx2-Wnt信号均被英夫利昔单抗抑制。该项目的主要目标是评估如何靶向这些信号来改善主动脉钙化、结构和顺应性。目的1：“测试tnf - α拮抗剂英夫利昔单抗或水杨酸盐是否能抑制动脉BMP2- Wnt诱导，改善糖尿病血管疾病的主动脉顺应性。”通过使用离体视频容积图评估主动脉压力-直径的关系，我们将在相关的T2DM模型中建立tnf - α与主动脉钙积累、Wnt信号和僵硬度之间的关系。LDLR-/-小鼠饲喂致糖尿病性高脂饲料（HFD）。将与RANKL抑制剂OPG的反应进行比较。目的2：“表征TNF- α信号通过NADPH氧化酶促进主动脉内膜肌成纤维细胞中Msx2基因转录的机制。”NAPDH氧化酶抑制剂，apocynin，抑制tnf - α（转录介导）诱导Msx2。通过识别响应tnf - α传递Msx2诱导的信号级联，可以设计新的策略来抑制血管钙化。目的3：“为了确定是否需要NADPH氧化酶信号来诱导T2DM患者主动脉BMP2-Msx-2-Wnt级联，使用p47phox- /-；TOPGAL +;以LDLR-/-小鼠为模型。”通过表型分析p47phox-/-；TOPGAL +;LDLR-/-和p47phox+/-；TOPGAL+；LDLR-/-对照，我们评估这种TNF-调节的氧化还原途径是否有助于HFD激活主动脉BMP2-Msx2-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.