TRIM40 ameliorates diabetic retinopathy through suppressing inflammation via Reelin/DAB1 signaling disruption: A mechanism by proteasomal degradation of DAB1.
TRIM40 ameliorates diabetic retinopathy through suppressing inflammation via Reelin/DAB1 signaling disruption: A mechanism by proteasomal degradation of DAB1.
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DOI：
10.1016/j.bbrc.2023.04.020
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发表时间：
2023-04
影响因子：
3.1
通讯作者：
X. Xiaoling;Lan Xinmei;Fu Shuhua;Zhang Qian;Gui Fu;Jin Qifang;Xie Lin;Yu Xiong
中科院分区：
文献类型：
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作者：
X. Xiaoling;Lan Xinmei;Fu Shuhua;Zhang Qian;Gui Fu;Jin Qifang;Xie Lin;Yu Xiong
糖尿病视网膜病变(DR)是糖尿病常见的微血管并发症。Reelin是一种细胞外基质蛋白，其效应蛋白Disabled1(DAB1)与细胞事件和视网膜发育有关。然而，Reelin/DAB1信号是否以及如何导致DR仍有待研究。在本研究中，我们观察到链脲佐菌素(STZ)诱导的DR小鼠模型视网膜中Reelin、极低密度脂蛋白受体(VLDLR)、载脂蛋白E受体2(ApoER2)和磷酸化DAB1的表达显著增加，同时促炎因子的表达也增强。在高糖(HG)处理的人视网膜色素上皮细胞系ARPE-19中也证实了类似的结果。令人惊讶的是，生物信息学分析发现，E3泛素连接酶TRIM40参与了DR的进展。我们观察到在HG条件下TRIM40和p-DAB1蛋白表达水平呈负相关。重要的是，我们发现TRIM40过表达显著改善了HG诱导的p-DAB1、PI3K、p-蛋白B激酶(AKT)和炎症反应，但不影响Reelin的表达。值得注意的是，Co-IP和双重免疫荧光确定了TRIM40和DAB1之间的相互作用。此外，我们还表明，TRIM40增强了K48连接的DAB1的多泛素化，从而促进了DAB1的降解。最后，静脉注射构建的腺相关病毒(AAV-TRIM40)促进TRIM40的表达显著改善STZ处理的小鼠的DR表型，表现为降低血糖和糖化血红蛋白(HbAlc)水平，增加血红蛋白含量。此外，在过度表达TRIM40的小鼠中，糖尿病相关的无细胞毛细血管的增加也得到了改善。注射AAV-TRIM40的小鼠的视网膜电信号(ERG)缺陷得到了有力的恢复。此外，AAV-TRIM40可减轻STZ处理的小鼠视网膜组织中的炎症和p-DAB1的表达。总之，我们的发现揭示了TRIM40在生理条件下限制DAB1稳定性的机制，并揭示了TRIM40作为干预Reelin/DAB1信号的潜在治疗靶点，有助于DR的治疗。
Diabetic retinopathy (DR) is a common microvascular complication of diabetes mellitus. Reelin, an extracellular matrix protein, and its effector protein Disabled1 (DAB1) have been linked to cellular events and retinal development. However, whether and how Reelin/DAB1 signaling causes DR remains to be investigated. In our study, significantly increased expression of Reelin, very low density lipoprotein receptor (VLDLR), ApoE receptor 2 (ApoER2) and phosphorylated DAB1 in retinas of streptozotocin (STZ)-induced DR mouse model was observed, along with enhanced expression of proinflammatory factors. Similar results are confirmed in high glucose (HG)-treated human retinal pigment epithelium cell line ARPE-19. Surprisingly, dysregulated tripartite motif-containing 40 (TRIM40), an E3 ubiquitin ligase, is found to be involved in DR progression by bioinformatic analysis. We observe a negative correlation between TRIM40 and p-DAB1 protein expression levels under HG conditions. Importantly, we find that TRIM40 over-expression markedly ameliorates HG-induced p-DAB1, PI3K, p-protein B kinase (AKT) and inflammatory response in HG-treated cells, but dose not affect Reelin expression. Of note, Co-IP and double immunofluorescence identify an interaction between TRIM40 and DAB1. Furthermore, we show that TRIM40 enhances K48-linked polyubiquitination of DAB1, thereby promoting DAB1 degradation. Finally, promoting TRIM40 expression by intravenous injection of the constructed adeno-associated virus (AAV-TRIM40) markedly ameliorates DR phenotypes in STZ-treated mice, as indicated by the decreased blood glucose and glycosylated hemoglobin (HbAlc) levels, and increased hemoglobin contents. Additionally, diabetes-related elevation of acellular capillaries was also meliorated in mice over-expressing TRIM40. The electroretinogram (ERG) deficits were strongly rescued in mice receiving AAV-TRIM40 injection. Moreover, AAV-TRIM40 attenuates the inflammation and p-DAB1 expression in retinal tissues of STZ-treated mice. Collectively, our findings disclose a mechanism through which TRIM40 limits DAB1 stability under physiological conditions and reveals TRIM40 as a potential therapeutic target for the intervention of Reelin/DAB1 signaling, contributing to DR treatment.