Department of Cardiology and Hematology, Fukushima Medical University, Fukushima, Japan.
J Cell Physiol. 2011 Jun;226(6):1554-63. doi: 10.1002/jcp.22492.
An advanced glycation end products (AGE)/a receptor for AGE (RAGE) axis plays a key role in diabetic vascular complications. Membrane type 1-matrix metalloproteinase (MT1-MMP) has been shown to function not only as a proteolytic enzyme but also as a signaling molecule. In this study, we investigated the role of MT1-MMP in the AGE/RAGE-triggered signaling pathways in cultured rabbit smooth muscle cells (SMCs) and the molecular interaction between RAGE and MT1-MMP in vitro and in vivo. In SMCs, AGE-activated Rac1 and p47(phox) within 1 min, NADPH oxidase activity and reactive oxygen species (ROS) generation within 5 min, and NF-κB phosphorylation within 15 min, thereby inducing redox-sensitive molecular expression. Silencing of RAGE by small-interfering RNA (siRNA) blocked the AGE-induced signaling pathways. AGE-induced geranylgeranyl transferase I (GGTase I) activity, Rac1·p47(phox) activation, NADPH oxidase activity, ROS generation, and molecular expression were also markedly attenuated by silencing of MT1-MMP. An inhibitor of GGTase I mimicked the effects of MT1-MMP-specific siRNA. Fluorescent immunohistochemistry revealed that MT1-MMP was partially co-localized with RAGE in SMCs, and RAGE was found to form a complex with MT1-MMP in both cultured SMCs and the aortae of diabetic rats by immunoprecipitation. Furthermore, MT1-MMP and RAGE formed a complex in the aortic atherosclerotic lesions of hyperlipidemic rabbits. We show that MT1-MMP plays a crucial role in RAGE-activated NADPH oxidase-dependent signaling pathways and forms a complex with RAGE in the vasculature, thus suggesting that MT1-MMP may be a novel therapeutic target for diabetic vascular complications.
糖基化终产物/糖基化终产物受体（AGE/RAGE）轴在糖尿病血管并发症中发挥关键作用。已经表明，膜型 1-基质金属蛋白酶（MT1-MMP）不仅具有蛋白水解酶的功能，而且还作为信号分子发挥作用。在这项研究中，我们研究了 MT1-MMP 在培养的兔平滑肌细胞（SMC）中 AGE/RAGE 触发的信号通路中的作用，以及 RAGE 和 MT1-MMP 之间的分子相互作用在体外和体内。在 SMC 中，AGE 在 1 分钟内激活 Rac1 和 p47(phox)，在 5 分钟内激活 NADPH 氧化酶活性和活性氧（ROS）生成，在 15 分钟内磷酸化 NF-κB，从而诱导氧化还原敏感的分子表达。用小干扰 RNA（siRNA）沉默 RAGE 阻断了 AGE 诱导的信号通路。AGE 诱导的 geranylgeranyl transferase I (GGTase I) 活性、Rac1·p47(phox) 激活、NADPH 氧化酶活性、ROS 生成和分子表达也被 MT1-MMP 的沉默显著减弱。GGTase I 抑制剂模拟了 MT1-MMP 特异性 siRNA 的作用。荧光免疫组织化学显示，在 SMC 中，MT1-MMP 与 RAGE 部分共定位，通过免疫沉淀发现 RAGE 在培养的 SMC 和糖尿病大鼠的主动脉中与 MT1-MMP 形成复合物。此外，在高脂血症兔的主动脉粥样硬化病变中，MT1-MMP 和 RAGE 形成复合物。我们表明，MT1-MMP 在 RAGE 激活的 NADPH 氧化酶依赖性信号通路中发挥关键作用，并在血管中与 RAGE 形成复合物，因此表明 MT1-MMP 可能是糖尿病血管并发症的新的治疗靶点。
