TNFR1-Activated Reactive Oxidative Species Signals Up-Regulate Osteogenic Msx2 Programs in Aortic Myofibroblasts
TNFR1-Activated Reactive Oxidative Species Signals Up-Regulate Osteogenic Msx2 Programs in Aortic Myofibroblasts
复制标题
DOI：
10.1210/en.2012-1216
复制
发表时间：
2012-08-01
期刊：
影响因子：
4.8
通讯作者：
Towler, Dwight A.
中科院分区：
文献类型：
--
作者：
Lai, Chung-Fang;Shao, Jian-Su;Towler, Dwight A.
在喂食高脂肪致糖尿病饮食的LDLR-/-小鼠中，成骨基因调控程序在血管肌成纤维细胞和平滑肌细胞中被异位激活，促进动脉硬化性钙沉积。Msx2-Wnt信号通路先前被认为对颅面骨骼发育很重要，在血管中被TNF诱导，TNF是糖尿病低度全身性炎症的一种原型细胞因子介质。为了更好地理解这一生物学特性，我们研究了TNF对主动脉肌成纤维细胞中Msx2的作用。TNF在3 h内上调Msx2 mRNA 4倍，但对Msx1无调节作用。虽然IL-1 β也能诱导Msx2表达，但tnf相关的凋亡诱导配体、核因子κ B受体激活剂配体和IL-6均无活性。烟酰胺腺嘌呤二核苷酸磷酸氧化酶（Nox）活性的抑制和遗传诱导的Nox缺乏（p47phox(-/-)）降低了Msx2的诱导，表明活性氧（ROS）和氧化还原信号的作用。与此一致的是，线粒体复合物I的拮拮剂鱼藤酮抑制TNF对Msx2和Nox2的诱导，而无胸性线粒体代谢底物丙酮酸则增强了诱导。此外，类似谷胱甘肽过氧化物酶的依布硒消除了这种TNF反应。过氧化氢治疗主动脉肌成纤维细胞上调Msx2 mRNA、启动子活性和dna -蛋白相互作用。在体内，SM22-TNF转基因小鼠表现出主动脉Msx2增加，而Msx1没有变化。给SM22-TNF小鼠20 ng/g Nox1 + 20 ng/g Nox2反义寡核苷酸或低剂量鱼烯酮均可降低动脉Msx2表达。来自TNFR1（-/-）小鼠的主动脉肌成纤维细胞表达的Msx2水平为野生型的5%，并且不受TNF诱导。Wnt7b和活性β -连环蛋白水平也有所降低。相比之下，tnf诱导的Msx2在TNFR2（-/-）细胞中的表达并未降低。最后，在矿化条件下培养时，与野生型和TNFR2（-/-）细胞相比，TNFR1（-/-）主动脉肌成纤维细胞的钙化程度降低。因此，ROS代谢有助于TNF通过TNFR1诱导肌成纤维细胞的Msx2和钙原反应。减少血管Nox或线粒体激活的ROS信号的策略可能有助于减轻动脉硬化性钙化。（内分泌学153:3897-3910,2012）
In LDLR-/- mice fed high-fat diabetogenic diets, osteogenic gene-regulatory programs are ectopically activated in vascular myofibroblasts and smooth muscle cells that promote arteriosclerotic calcium deposition. Msx2-Wnt signaling pathways previously identified as important for craniofacial skeletal development are induced in the vasculature by TNF, a prototypic cytokine mediator of the low-grade systemic inflammation of diabesity. To better understand this biology, we studied TNF actions on Msx2 in aortic myofibroblasts. TNF up-regulated Msx2 mRNA 4-fold within 3 h but did not regulate Msx1. Although IL-1 beta could also induce Msx2 expression, TNF-related apoptosis inducing ligand, receptor activator of nuclear factor-kappa B ligand, and IL-6 were inactive. Inhibition of nicotinamide adenine dinucleotide phosphate oxidase (Nox) activity and genetically induced Nox deficiency (p47phox(-/-)) reduced Msx2 induction, indicating contributions of reactive oxygen species (ROS) and redox signaling. Consistent with this, rotenone, an antagonist of mitochondrial complex I, inhibited TNF induction of Msx2 and Nox2, whereas pyruvate, an anapleurotic mitochondrial metabolic substrate, enhanced induction. Moreover, the glutathione peroxidase-mimetic ebselen abrogated this TNF response. Treatment of aortic myofibroblasts with hydrogen peroxide up-regulated Msx2 mRNA, promoter activity, and DNA-protein interactions. In vivo, SM22-TNF transgenic mice exhibit increased aortic Msx2 with no change in Msx1. Dosing SM22-TNF mice with either 20 ng/g Nox1 + 20 ng/g Nox2 antisense oligonucleotides or low-dose rotenone reduced arterial Msx2 expression. Aortic myofibroblasts from TNFR1(-/-) mice expressed levels of Msx2 that were 5% that of wild-type and were not inducible by TNF. Wnt7b and active beta-catenin levels were also reduced. By contrast, TNF-inducible Msx2 expression was not reduced in TNFR2(-/-) cells. Finally, when cultured under mineralizing conditions, TNFR1(-/-) aortic myofibroblasts exhibited reduced calcification compared with wild-type and TNFR2(-/-) cells. Thus, ROS metabolism contributes to TNF induction of Msx2 and procalcific responses in myofibroblasts via TNFR1. Strategies that reduce vascular Nox- or mitochondrially activated ROS signals may prove useful in mitigating arteriosclerotic calcification. (Endocrinology 153: 3897-3910, 2012)