PDF(Pubmed)
Abstract：
Cardiolipin (CL) plays a critical role in maintaining mitochondrial membrane integrity and overall mitochondrial homeostasis. Recent studies have suggested that mitochondrial damage resulting from abnormal cardiolipin remodelling is associated with the pathogenesis of diabetic kidney disease (DKD). Acyl-coenzyme A:lyso-cardiolipin acyltransferase-1 (ALCAT1) was confirmed to be involved in the progression of Parkinson\'s disease, diet-induced obesity and other ageing-related diseases by regulating pathological cardiolipin remodelling. Thus, the purpose of this investigation was to determine the role of ALCAT1-mediated CL remodelling in DKD and to explore the potential underlying mechanism.
In vivo study, the mitochondrial structure was examined by transmission electron microscopy (TEM). The colocalization of ALCAT1 and synaptopodin was evaluated by double immunolabelling. Western blotting (WB) was performed to assess ALCAT1 expression in glomeruli. Lipidomics analysis was conducted to evaluate the composition of reconstructed cardiolipins. In vitro study, the lipidomics, TEM and WB analyses were similar to those in vivo. Mitochondrial function was evaluated by measuring the mitochondrial membrane potential (MMP) and the production of ATP and ROS.
Here, we showed that increased oxidized cardiolipin (ox-CL) and significant mitochondrial damage were accompanied by increased ALCAT1 expression in the glomeruli of patients with DKD. Similar results were found in db/db mouse kidneys and in cultured podocytes stimulated with high glucose (HG). ALCAT1 deficiency effectively prevented HG-induced ox-CL production and mitochondrial damage in podocytes. In contrast, ALCAT1 upregulation enhanced ox-CL levels and podocyte mitochondrial dysfunction. Moreover, treatment with the cardiolipin antioxidant SS-31 markedly inhibited mitochondrial dysfunction and cell injury, and SS-31 treatment partly reversed the damage mediated by ALCAT1 overexpression. We further found that ALCAT1 could mediate the key regulators of mitochondrial dynamics and mitophagy through the AMPK pathway.
Collectively, our studies demonstrated that ALCAT1-mediated cardiolipin remodelling played a crucial role in DKD, which might provide new insights for DKD treatment. Video Abstract.
In vivo study, the mitochondrial structure was examined by transmission electron microscopy (TEM). The colocalization of ALCAT1 and synaptopodin was evaluated by double immunolabelling. Western blotting (WB) was performed to assess ALCAT1 expression in glomeruli. Lipidomics analysis was conducted to evaluate the composition of reconstructed cardiolipins. In vitro study, the lipidomics, TEM and WB analyses were similar to those in vivo. Mitochondrial function was evaluated by measuring the mitochondrial membrane potential (MMP) and the production of ATP and ROS.
Here, we showed that increased oxidized cardiolipin (ox-CL) and significant mitochondrial damage were accompanied by increased ALCAT1 expression in the glomeruli of patients with DKD. Similar results were found in db/db mouse kidneys and in cultured podocytes stimulated with high glucose (HG). ALCAT1 deficiency effectively prevented HG-induced ox-CL production and mitochondrial damage in podocytes. In contrast, ALCAT1 upregulation enhanced ox-CL levels and podocyte mitochondrial dysfunction. Moreover, treatment with the cardiolipin antioxidant SS-31 markedly inhibited mitochondrial dysfunction and cell injury, and SS-31 treatment partly reversed the damage mediated by ALCAT1 overexpression. We further found that ALCAT1 could mediate the key regulators of mitochondrial dynamics and mitophagy through the AMPK pathway.
Collectively, our studies demonstrated that ALCAT1-mediated cardiolipin remodelling played a crucial role in DKD, which might provide new insights for DKD treatment. Video Abstract.
摘要：
背景：心磷脂（CL）在维持线粒体膜完整性和整体线粒体稳态中起关键作用。最近的研究表明，由心磷脂异常重塑引起的线粒体损伤与糖尿病肾病（DKD）的发病机理有关。酰基辅酶A：溶血心磷脂酰基转移酶-1（ALCAT1）被证实参与帕金森病的进展，通过调节病理性心磷脂重塑，饮食引起的肥胖和其他与衰老有关的疾病。因此，本研究的目的是确定ALCAT1介导的CL重塑在DKD中的作用,并探讨潜在的潜在机制.
方法：体内研究，通过透射电子显微镜（TEM）检查线粒体结构。通过双重免疫标记评估ALCAT1和突触素的共定位。进行蛋白质印迹(WB)以评估ALCATl在肾小球中的表达。进行脂质组学分析以评估重建的心磷脂的组成。体外研究,脂质组学，TEM和WB分析与体内相似。通过测量线粒体膜电位（MMP）以及ATP和ROS的产生来评估线粒体功能。
结果：这里，我们发现DKD患者肾小球中氧化心磷脂(ox-CL)的增加和显著的线粒体损伤伴随着ALCAT1表达的增加。在db/db小鼠肾脏和用高葡萄糖（HG）刺激的培养足细胞中发现了类似的结果。ALCAT1缺乏可有效预防HG诱导的足细胞ox-CL产生和线粒体损伤。相比之下,ALCAT1上调增强ox-CL水平和足细胞线粒体功能障碍。此外，用心磷脂抗氧化剂SS-31治疗可显著抑制线粒体功能障碍和细胞损伤，和SS-31治疗部分逆转了ALCAT1过表达介导的损伤。我们进一步发现ALCAT1可以通过AMPK通路介导线粒体动力学和线粒体自噬的关键调节因子。
结论：总的来说，我们的研究表明，ALCAT1介导的心磷脂重塑在DKD中起着至关重要的作用，这可能为DKD治疗提供新的见解。视频摘要。
方法：体内研究，通过透射电子显微镜（TEM）检查线粒体结构。通过双重免疫标记评估ALCAT1和突触素的共定位。进行蛋白质印迹(WB)以评估ALCATl在肾小球中的表达。进行脂质组学分析以评估重建的心磷脂的组成。体外研究,脂质组学，TEM和WB分析与体内相似。通过测量线粒体膜电位（MMP）以及ATP和ROS的产生来评估线粒体功能。
结果：这里，我们发现DKD患者肾小球中氧化心磷脂(ox-CL)的增加和显著的线粒体损伤伴随着ALCAT1表达的增加。在db/db小鼠肾脏和用高葡萄糖（HG）刺激的培养足细胞中发现了类似的结果。ALCAT1缺乏可有效预防HG诱导的足细胞ox-CL产生和线粒体损伤。相比之下,ALCAT1上调增强ox-CL水平和足细胞线粒体功能障碍。此外，用心磷脂抗氧化剂SS-31治疗可显著抑制线粒体功能障碍和细胞损伤，和SS-31治疗部分逆转了ALCAT1过表达介导的损伤。我们进一步发现ALCAT1可以通过AMPK通路介导线粒体动力学和线粒体自噬的关键调节因子。
结论：总的来说，我们的研究表明，ALCAT1介导的心磷脂重塑在DKD中起着至关重要的作用，这可能为DKD治疗提供新的见解。视频摘要。
