BACKGROUND Calcium oxalate-induced acute kidney injury is a severe condition in which the kidneys suffer rapid damage due to the deposition of oxalate crystals. Known factors contributing to cell death induced by calcium oxalate include receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase domain-like (MLKL) protein dependent necroptosis, as well as necrosis involving peptidylprolyl isomerase F (PPIF) mediated mitochondrial permeability transition. However, the detailed molecular mechanisms linking mitochondrial dysfunction to RIPK3 activation are not fully understood. METHODS Mice with gene knock-out of Zbp1, Ripk3, or Mlkl and mice with mutations in the Z-nucleic acid sensing domain of ZBP1 or deletion of Zα1 were used in an oxalate-induced AKI model. Proximal renal tubule cells were isolated and cultured for further investigation. Human oxalate nephropathy biopsy samples were analyzed. RESULTS Specific gene deletions of Zbp1, Ripk3, or Mlkl in proximal renal tubules significantly reduced the severity of oxalate-induced AKI by preventing necroptosis and subsequent inflammation. Notably, mice with mutations in the Z-nucleic acid sensing domain of ZBP1 or deletion of Zα1 were protected from AKI. In cultured proximal tubular cells, calcium oxalate damaged mitochondria, accompanied by an increase in Bax and a decrease in BCL2 and TAFM, leading to the release of mitochondrial Z-DNA. ZBP1 sensed this mitochondrial Z-DNA and then recruited RIPK3 via the RIP homotypic interaction motifs (RHIM), which in turn activated MLKL through RIPK3 phosphorylation, leading to necroptosis and contributing to AKI. CONCLUSIONS ZBP1 plays a critical role in sensing mitochondrial Z-DNA and initiating RIPK3/MLKL-mediated necroptosis, contributing to the development of oxalate-induced AKI.

中文翻译：

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Z-DNA 结合蛋白 1 感应线粒体 z-DNA 并触发坏死性凋亡在草酸盐诱导的急性肾损伤中的作用。


背景 草酸钙诱导的急性肾损伤是一种严重的疾病，其中肾脏由于草酸盐晶体的沉积而遭受迅速损伤。导致草酸钙诱导细胞死亡的已知因素包括受体相互作用蛋白激酶 3 （RIPK3） 和混合谱系激酶结构域样 （MLKL） 蛋白依赖性坏死性凋亡，以及涉及肽基脯氨酰异构酶 F （PPIF） 介导的线粒体通透性转换的坏死。然而，将线粒体功能障碍与 RIPK3 激活联系起来的详细分子机制尚不完全清楚。方法 将 Zbp1 、 Ripk3 或 Mlkl 基因敲除的小鼠以及 ZBP1 的 Z 核酸感应结构域突变或 Zα1 缺失的小鼠用于草酸盐诱导的 AKI 模型。分离并培养近端肾小管细胞以供进一步研究。分析人草酸盐肾病活检标本。结果 近端肾小管中 Zbp1 、 Ripk3 或 Mlkl 的特异性基因缺失通过预防坏死性凋亡和随后的炎症，显著降低了草酸盐诱导的 AKI 的严重程度。值得注意的是，ZBP1 的 Z 核酸感应结构域突变或 Zα1 缺失的小鼠受到保护，不会发生 AKI。在培养的近端肾小管细胞中，草酸钙损害了线粒体，伴随着 Bax 的增加和 BCL2 和 TAFM 的减少，导致线粒体 Z-DNA 的释放。ZBP1 感应这种线粒体 Z-DNA，然后通过 RIP 同型相互作用基序 （RHIM） 募集 RIPK3，这反过来又通过 RIPK3 磷酸化激活 MLKL，导致坏死性凋亡并导致 AKI。 结论 ZBP1 在传感线粒体 Z-DNA 和启动 RIPK3/MLKL 介导的坏死性凋亡中起关键作用，有助于草酸盐诱导的 AKI 的发展。