Ubiquitin-Fold Modifier-I Participates in the Diabetic Inflammatory Response by Regulating NF-κB p65 Nuclear Translocation and the Ubiquitination and Degradation of IκBα
Ubiquitin-Fold Modifier-I Participates in the Diabetic Inflammatory Response by Regulating NF-κB p65 Nuclear Translocation and the Ubiquitination and Degradation of IκBα
复制标题
DOI：
10.2147/dddt.s238695
复制
发表时间：
2020-01-01
影响因子：
4.8
通讯作者：
Chen, Fengling
中科院分区：
文献类型：
--
作者：
Hu, Xiaolei;Zhang, Hengyan;Chen, Fengling
背景泛素折叠修饰因子1（Ufm 1）是最近发现的一种泛素样蛋白。我们先前证实，Ufm 1的表达在糖尿病小鼠中增加。然而，其在糖尿病发展中的作用仍不明确。方法采用慢病毒介导的基因敲低和过表达技术，观察Ufm 1对巨噬细胞炎性因子、粘附分子和趋化因子表达及核因子κ-B（NF-κB）转录活性的影响。采用Western blot和免疫荧光技术分析Ufm 1对NF-κB转录活性的影响机制。最后，观察Ufm 1对db/db小鼠炎症以及胰腺、肾脏和心肌损伤的影响。结果靶向Ufm 1的慢病毒shRNA（Lv-shUfm 1）敲除Ufm 1后，LPS和TNF-α刺激的RAW 264. 7细胞IL-6、IL-1β、ICAM-1、VCAM-1、MCP-1和CXCL 2的分泌减少，而过表达Ufm 1（Lv-Ufm 1）则相反。有趣的是，进一步的研究表明Ufm 1通过增加IκBα的泛素化和降解，诱导NF-κB p65核转位。在体内实验中，用Lv-shUfm 1预处理db/db小鼠可降低驻留的腹膜巨噬细胞（RPM）中TNF-α、IL-6、IL-1β、ICAM-1、VCAM-1、MCP-1和CXCL 2的mRNA水平，并降低TNF-α、IL-6、IL-1β、ICAM-1、VCAM-1、MCP-1和CXCL 2的血浆水平。此外，在Lv-Ufm 1处理的小鼠中，观察到相反的结果。Lv-shUfm 1和Lv-Ufm 1处理后，RPM中NF-κB p65核转位分别减少和增加。重要的是，我们观察到Lv-shUfm 1注射导致血浆甘油三酯减少，尿蛋白尿和心肌细胞肥大减少，胰腺，肾脏和心肌组织的组织病理学外观改善。用Lv-shUfm 1预处理小鼠抑制胰腺、肾脏和心肌组织中的巨噬细胞浸润。结论Ufm 1介导炎症反应，是一种新的生物学功能。Ufm 1介导的p65核转位通过调节IκBα的泛素化和降解而发生。此外，下调Ufm 1是预防2型糖尿病及其并发症发展的有效策略。
Background Ubiquitin-fold modifier-1 (Ufm1) is a recently identified ubiquitin-like protein. We previously confirmed that Ufm1 expression was increased in diabetic mice. However, its role in the development of diabetes remains undefined. Methods Lentivirus-mediated gene knockdown and overexpression techniques were used to observe the effect of Ufm1 on the expression of inflammatory factors, adhesion molecules and chemokines, as well as the transcriptional activity of nuclear factor kappa-B (NF-κB) in macrophages. Western blot and immunofluorescence analyses were used to analyse the mechanism by which Ufm1 affects the transcriptional activity of NF-κB. Finally, the effects of Ufm1 on inflammation and pancreatic, renal and myocardial damage were observed in db/db mice. Results Knockdown of Ufm1 by lentivirus shRNA targeting Ufm1 (Lv-shUfm1) led to decreased secretion of IL-6, IL-1β, ICAM-1, VCAM-1, MCP-1 and CXCL2 in RAW264.7 cells that were exposed to LPS and TNF-α, while lentiviral overexpression of Ufm1 (Lv-Ufm1) caused the opposite effect. Interestingly, further investigation indicated that Ufm1 induced NF-κB p65 nuclear translocation in RAW264.7 cells via increasing the ubiquitination and degradation of IκBα. In an in vivo experiment, pretreatment of db/db mice with Lv-shUfm1 reduced the mRNA levels of TNF-α, IL-6, IL-1β, ICAM-1, VCAM-1, MCP-1 and CXCL2 in resident peritoneal macrophages (RPMs) and decreased the plasma levels of TNF-α, IL-6, IL-1β, ICAM-1, VCAM-1, MCP-1 and CXCL2. Additionally, in Lv-Ufm1-treated mice, the inverse results were observed. Following treatment with Lv-shUfm1 and Lv-Ufm1, NF-κB p65 nuclear translocation in RPMs was decreased and increased, respectively. Importantly, we observed that Lv-shUfm1 injection led to a decrease in plasma glycaemia, a reduction in urinary albuminuria and cardiomyocyte hypertrophy and an improvement in the histopathological appearance of pancreatic, kidney and myocardial tissue. Pretreatment of the mice with Lv-shUfm1 inhibited macrophage infiltration in the pancreas, kidney and myocardial tissue. Conclusion Our data elucidate a new biological function of Ufm1 that mediates inflammatory responses. Ufm1-mediated p65 nuclear translocation occurs by modulating the ubiquitination and degradation of IκBα. Moreover, downregulating Ufm1 is an effective strategy to prevent the development of type 2 diabetes and its complications.