State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangdong Provincial Institute of Nephrology, and Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Guangdong Provincial Institute of Nephrology, and Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Redox Biol. 2023 Nov;67:102868. doi: 10.1016/j.redox.2023.102868. Epub 2023 Sep 1.
Kidney fibrosis is associated with tubular injury, oxidative stress and activation of interstitial fibroblasts. However, whether these events are somehow connected is poorly understood. In this study, we show that glutathione peroxidase-3 (GPX3) depletion in renal tubular epithelium after kidney injury plays a central role in orchestrating an oxidatively stressed extracellular microenvironment, which drives interstitial fibroblast activation and proliferation. Through transcriptional profiling by RNA-sequencing, we found that the expression of GPX3 was down-regulated in various models of chronic kidney disease (CKD), which was correlated with induction of nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase-4 (NOX4). By using decellularized extracellular matrix (ECM) scaffold, we demonstrated that GPX3-depleted extracellular microenvironment spontaneously induced NOX4 expression and reactive oxygen species (ROS) production in renal fibroblasts and triggered their activation and proliferation. Activation of NOX4 by advanced oxidation protein products (AOPPs) mimicked the loss of GPX3, increased the production of ROS, stimulated fibroblast activation and proliferation, and activated protein kinase C-α (PKCα)/mitogen-activated protein kinase (MAPK)/signal transducer and activator of transcription 3 (STAT3) signaling. Silencing NOX4 or inhibition of MAPK with small molecule inhibitors hampered fibroblast activation and proliferation. In mouse model of CKD, knockdown of NOX4 repressed renal fibroblast activation and proliferation and alleviated kidney fibrosis. These results indicate that loss of GPX3 orchestrates an oxidatively stressed extracellular microenvironment, which promotes fibroblast activation and proliferation through a cascade of signal transduction. Our studies underscore the crucial role of extracellular microenvironment in driving fibroblast activation and kidney fibrosis.
肾纤维化与肾小管损伤、氧化应激和间质成纤维细胞激活有关。然而，这些事件之间是否存在某种联系尚不清楚。在这项研究中，我们表明，肾损伤后肾小管上皮细胞中谷胱甘肽过氧化物酶 3（GPX3）的耗竭在协调氧化应激细胞外微环境中发挥核心作用，该微环境驱动间质成纤维细胞的激活和增殖。通过 RNA 测序的转录谱分析，我们发现各种慢性肾脏病（CKD）模型中 GPX3 的表达下调，这与烟酰胺腺嘌呤二核苷酸磷酸（NAPDH）氧化酶 4（NOX4）的诱导相关。通过使用去细胞细胞外基质（ECM）支架，我们证明了 GPX3 耗竭的细胞外微环境自发诱导肾脏成纤维细胞中 NOX4 的表达和活性氧（ROS）的产生，并触发其激活和增殖。通过高级氧化蛋白产物（AOPPs）激活的 NOX4 模拟了 GPX3 的缺失，增加了 ROS 的产生，刺激了成纤维细胞的激活和增殖，并激活了蛋白激酶 C-α（PKCα）/丝裂原激活的蛋白激酶（MAPK）/信号转导和转录激活因子 3（STAT3）信号通路。沉默 NOX4 或用小分子抑制剂抑制 MAPK 阻碍了成纤维细胞的激活和增殖。在 CKD 的小鼠模型中，NOX4 的敲低抑制了肾脏成纤维细胞的激活和增殖，并减轻了肾脏纤维化。这些结果表明，GPX3 的缺失协调了氧化应激的细胞外微环境，通过级联信号转导促进成纤维细胞的激活和增殖。我们的研究强调了细胞外微环境在驱动成纤维细胞激活和肾脏纤维化中的关键作用。
