肌醇加氧酶在糖尿病肾病 AGE:RAGE 介导的肾间质小管损伤中的作用。
Contribution of myo-inositol oxygenase in AGE:RAGE-mediated renal tubulointerstitial injury in the context of diabetic nephropathy.
机构信息
Departments of Pathology and Medicine, Northwestern University , Chicago, Illinois.
Biochemical Sciences Division, Rajiv Gandhi Institute of IT and Biotechnology, Bharati Vidyapeeth University , Pune , India.
出版信息
Am J Physiol Renal Physiol. 2018 Jan 1;314(1):F107-F121. doi: 10.1152/ajprenal.00434.2017. Epub 2017 Sep 20.
Advanced glycation end products (AGEs) play a role in pathogenesis of diabetic nephropathy (DN). Myo-inositol oxygenase (MIOX) has been implicated in tubulointerstitial injury in the context of DN. We investigated the effect of AGEs on MIOX expression and delineated mechanisms that lead to tubulointerstitial injury. The status of MIOX, RAGE, and relevant cellular signaling pathways activated following AGE:RAGE interaction was examined in tubular cells and kidneys of AGE-BSA-treated mice. A solid-phase assay revealed an enhanced binding of RAGE with AGE-BSA, AGE-laminin, and AGE-collagen IV. The cells treated with AGE-BSA had increased MIOX activity/expression and promoter activity. This was associated with activation of various signaling kinases of phosphatidylinositol 3-kinase (PI3K)-AKT pathway and increased expression of NF-κB, transforming growth factor (TGF)-β, and fibronectin, which was negated with the treatment of MIOX/RAGE- small interfering (si) RNA. Concomitant with MIOX upregulation, there was an increased generation of reactive oxygen species (ROS), which could be abrogated with MIOX/RAGE- siRNA treatment. The kidneys of mice treated with AGE-BSA had significantly high urinary A/C ratio, upregulation of MIOX, RAGE and NF-κB, along with influx of monocytes into the tubulointerstitium, increased the expression of MCP-1, IL-6, and fibronectin and increased the generation of ROS. Such perturbations were abrogated with the concomitant treatment of inhibitors MIOX or RAGE (d-glucarate and FPS-ZM1). These studies support a role of AGE:RAGE interaction in the activation of PI3K-AKT pathway and upregulation of MIOX, with excessive generation of ROS, increased expression of NF-κB, inflammatory cytokines, TGF-β, and fibronectin. Collectively, these observations highlight the relevance of the biology of MIOX in the contribution toward tubulointerstitial injury in DN.
晚期糖基化终产物(AGEs)在糖尿病肾病(DN)的发病机制中起作用。肌醇氧化酶(MIOX)已被牵连到 DN 中的肾小管间质损伤中。我们研究了 AGEs 对 MIOX 表达的影响,并阐明了导致肾小管间质损伤的机制。在 AGE-BSA 处理的小鼠的肾小管细胞和肾脏中,检查了 MIOX、RAGE 以及在 AGE:RAGE 相互作用后激活的相关细胞信号通路的状态。固相测定显示 RAGE 与 AGE-BSA、AGE-层粘连蛋白和 AGE-胶原蛋白 IV 的结合增强。用 AGE-BSA 处理的细胞具有增加的 MIOX 活性/表达和启动子活性。这与磷酸肌醇 3-激酶(PI3K)-AKT 途径的各种信号激酶的激活以及 NF-κB、转化生长因子(TGF)-β和纤维连接蛋白的表达增加有关,用 MIOX/RAGE-小干扰(si)RNA 处理可消除这种情况。与 MIOX 上调同时发生的是活性氧(ROS)的产生增加,用 MIOX/RAGE-siRNA 处理可消除这种增加。用 AGE-BSA 处理的小鼠的肾脏具有显著升高的尿 A/C 比,MIOX、RAGE 和 NF-κB 的上调,以及单核细胞流入肾小管间质,增加单核细胞趋化蛋白 1(MCP-1)、白细胞介素 6(IL-6)和纤维连接蛋白的表达,以及 ROS 的产生增加。用 MIOX 或 RAGE(D-葡萄糖醛酸和 FPS-ZM1)的抑制剂的伴随治疗可消除这些干扰。这些研究支持 AGE:RAGE 相互作用在激活 PI3K-AKT 途径和上调 MIOX 中的作用,伴随着 ROS 的过度产生、NF-κB、炎症细胞因子、TGF-β和纤维连接蛋白表达增加。总之,这些观察结果强调了 MIOX 生物学在 DN 肾小管间质损伤中的相关性。