Abstract：
BACKGROUND: Acute kidney injury (AKI) is associated with high morbidity and mortality rates. The molecular mechanisms underlying AKI are currently being extensively investigated. WWP2 is an E3 ligase that regulates cell proliferation and differentiation. Whether WWP2 plays a regulatory role in AKI remains to be elucidated.
OBJECTIVE: We aimed to investigate the implication of WWP2 in AKI and its underlying mechanism in the present study.
METHODS: We utilized renal tissues from patients with AKI and established AKI models in global or tubule-specific knockout (cKO) mice strains to study WWP2\'s implication in AKI. We also systemically analyzed ubiquitylation omics and proteomics to decipher the underlying mechanism.
RESULTS: In the present study, we found that WWP2 expression significantly increased in the tubules of kidneys with AKI. Global or tubule-specific knockout of WWP2 significantly aggravated renal dysfunction and tubular injury in AKI kidneys, whereas WWP2 overexpression significantly protected tubular epithelial cells against cisplatin. WWP2 deficiency profoundly affected autophagy in AKI kidneys. Further analysis with ubiquitylation omics, quantitative proteomics and experimental validation suggested that WWP2 mediated poly-ubiquitylation of CDC20, a negative regulator of autophagy. CDC20 was significantly decreased in AKI kidneys, and selective inhibiting CDC20 with apcin profoundly alleviated renal dysfunction and tubular injury in the cisplatin model with or without WWP2 cKO, indicating that CDC20 may serve as a downstream target of WWP2 in AKI. Inhibiting autophagy with 3-methyladenine blocked apcin\'s protection against cisplatin-induced renal tubular cell injury. Activating autophagy by rapamycin significantly protected against cisplatin-induced AKI in WWP2 cKO mice, whereas inhibiting autophagy by 3-methyladenine further aggravated apoptosis in cisplatin-exposed WWP2 KO cells.
CONCLUSIONS: Taken together, our data indicated that the WWP2/CDC20/autophagy may be an essential intrinsic protective mechanism against AKI. Further activating WWP2 or inhibiting CDC20 may be novel therapeutic strategies for AKI.
OBJECTIVE: We aimed to investigate the implication of WWP2 in AKI and its underlying mechanism in the present study.
METHODS: We utilized renal tissues from patients with AKI and established AKI models in global or tubule-specific knockout (cKO) mice strains to study WWP2\'s implication in AKI. We also systemically analyzed ubiquitylation omics and proteomics to decipher the underlying mechanism.
RESULTS: In the present study, we found that WWP2 expression significantly increased in the tubules of kidneys with AKI. Global or tubule-specific knockout of WWP2 significantly aggravated renal dysfunction and tubular injury in AKI kidneys, whereas WWP2 overexpression significantly protected tubular epithelial cells against cisplatin. WWP2 deficiency profoundly affected autophagy in AKI kidneys. Further analysis with ubiquitylation omics, quantitative proteomics and experimental validation suggested that WWP2 mediated poly-ubiquitylation of CDC20, a negative regulator of autophagy. CDC20 was significantly decreased in AKI kidneys, and selective inhibiting CDC20 with apcin profoundly alleviated renal dysfunction and tubular injury in the cisplatin model with or without WWP2 cKO, indicating that CDC20 may serve as a downstream target of WWP2 in AKI. Inhibiting autophagy with 3-methyladenine blocked apcin\'s protection against cisplatin-induced renal tubular cell injury. Activating autophagy by rapamycin significantly protected against cisplatin-induced AKI in WWP2 cKO mice, whereas inhibiting autophagy by 3-methyladenine further aggravated apoptosis in cisplatin-exposed WWP2 KO cells.
CONCLUSIONS: Taken together, our data indicated that the WWP2/CDC20/autophagy may be an essential intrinsic protective mechanism against AKI. Further activating WWP2 or inhibiting CDC20 may be novel therapeutic strategies for AKI.
摘要：
背景：急性肾损伤（AKI）与高发病率和死亡率相关。目前正在广泛研究AKI的分子机制。WWP2是调节细胞增殖和分化的E3连接酶。WWP2是否在AKI中起调节作用还有待阐明。
目的：本研究旨在探讨WWP2在AKI中的意义及其潜在机制。
方法：我们利用AKI患者的肾组织，并在全局或肾小管特异性敲除（cKO）小鼠品系中建立AKI模型，以研究WWP2在AKI中的意义。我们还系统地分析了泛素化组学和蛋白质组学，以破译潜在的机制。
结果：在本研究中，我们发现WWP2在AKI肾脏肾小管中的表达显着增加。WWP2的整体或肾小管特异性敲除显着加重了AKI肾脏的肾功能障碍和肾小管损伤，而WWP2过表达显著保护肾小管上皮细胞抵抗顺铂。WWP2缺乏严重影响AKI肾脏的自噬。用泛素化组学进一步分析，定量蛋白质组学和实验验证表明，WWP2介导了自噬的负调节因子CDC20的多泛素化。CDC20在AKI肾脏中显著降低，在有或没有WWP2cKO的顺铂模型中，用apcin选择性抑制CDC20可以大大减轻肾功能障碍和肾小管损伤，表明CDC20可以作为AKI中WWP2的下游靶标。3-甲基腺嘌呤抑制自噬可阻断apcin对顺铂诱导的肾小管细胞损伤的保护作用。雷帕霉素激活自噬可显著保护WWP2cKO小鼠免受顺铂诱导的AKI,而3-甲基腺嘌呤抑制自噬进一步加重顺铂暴露的WWP2KO细胞的凋亡。
结论：综合来看，我们的数据表明WWP2/CDC20/自噬可能是抗AKI的重要内在保护机制.进一步激活WWP2或抑制CDC20可能是AKI的新治疗策略。
目的：本研究旨在探讨WWP2在AKI中的意义及其潜在机制。
方法：我们利用AKI患者的肾组织，并在全局或肾小管特异性敲除（cKO）小鼠品系中建立AKI模型，以研究WWP2在AKI中的意义。我们还系统地分析了泛素化组学和蛋白质组学，以破译潜在的机制。
结果：在本研究中，我们发现WWP2在AKI肾脏肾小管中的表达显着增加。WWP2的整体或肾小管特异性敲除显着加重了AKI肾脏的肾功能障碍和肾小管损伤，而WWP2过表达显著保护肾小管上皮细胞抵抗顺铂。WWP2缺乏严重影响AKI肾脏的自噬。用泛素化组学进一步分析，定量蛋白质组学和实验验证表明，WWP2介导了自噬的负调节因子CDC20的多泛素化。CDC20在AKI肾脏中显著降低，在有或没有WWP2cKO的顺铂模型中，用apcin选择性抑制CDC20可以大大减轻肾功能障碍和肾小管损伤，表明CDC20可以作为AKI中WWP2的下游靶标。3-甲基腺嘌呤抑制自噬可阻断apcin对顺铂诱导的肾小管细胞损伤的保护作用。雷帕霉素激活自噬可显著保护WWP2cKO小鼠免受顺铂诱导的AKI,而3-甲基腺嘌呤抑制自噬进一步加重顺铂暴露的WWP2KO细胞的凋亡。
结论：综合来看，我们的数据表明WWP2/CDC20/自噬可能是抗AKI的重要内在保护机制.进一步激活WWP2或抑制CDC20可能是AKI的新治疗策略。
