Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India.
Center for Systems Biology and Molecular Medicine, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Mangalore, Karnataka 575020, India.
Int J Biochem Cell Biol. 2024 Nov;176:106664. doi: 10.1016/j.biocel.2024.106664. Epub 2024 Sep 19.
In response to hyperglycemia, endothelial cells (ECs) release exosomes with altered protein content and contribute to paracrine signalling, subsequently leading to vascular dysfunction in type 2 diabetes (T2D). High glucose reprograms DNA methylation patterns in various cell/tissue types, including ECs, resulting in pathologically relevant changes in cellular and extracellular proteome. However, DNA methylation-based proteome reprogramming in endothelial exosomes and associated pathological implications in T2D are not known. Hence, in the present study, we used Human umbilical vein endothelial cells (HUVECs), High Fat Diet (HFD) induced diabetic mice (C57BL/6) and clinical models to understand epigenetic basis of exosome proteome regulation in T2D pathogenesis . Exosomes were isolated by size exclusion chromatography and subjected to tandem mass tag (TMT) labelled quantitative proteomics and bioinformatics analysis. Immunoblotting was performed to validate exosome protein signature in clinically characterized individuals with T2D. We observed ECs cultured in high glucose and aortic ECs from HFD mouse expressed elevated DNA methyltransferase1 (DNMT1) levels. Quantitative proteomics of exosomes isolated from ECs treated with high glucose and overexpressing DNMT1 showed significant alterations in both protein levels and post translational modifications which were aligned to T2D associated vascular functions. Based on ontology and gene-function-disease interaction analysis, differentially expressed exosome proteins such as Thrombospondin1, Pentraxin3 and Cystatin C related to vascular complications were significantly increased in HUVECs treated with high glucose and HFD animals and T2D individuals with higher levels of glycated hemoglobin. These proteins were reduced upon treatment with 5-Aza-2'-deoxycytidine. Our study shows epigenetic regulation of exosome proteome in T2D associated vascular complications.
针对高血糖,内皮细胞 (ECs) 会释放出内容蛋白发生改变的外泌体,并进行旁分泌信号传递,进而导致 2 型糖尿病 (T2D) 中的血管功能障碍。高血糖会重新编程各种细胞/组织类型(包括 ECs)中的 DNA 甲基化模式,导致细胞外蛋白质组发生与病理相关的变化。然而,内皮细胞外泌体中基于 DNA 甲基化的蛋白质组重编程以及在 T2D 中的相关病理影响尚不清楚。因此,在本研究中,我们使用人脐静脉内皮细胞 (HUVECs)、高脂肪饮食 (HFD) 诱导的糖尿病小鼠 (C57BL/6) 和临床模型来了解 T2D 发病机制中外泌体蛋白质组调节的表观遗传基础。通过大小排阻色谱法分离外泌体,并进行串联质量标签 (TMT) 标记定量蛋白质组学和生物信息学分析。使用免疫印迹法验证了具有 T2D 的临床特征个体中外泌体蛋白特征。我们观察到在高葡萄糖中培养的 ECs 和 HFD 小鼠的主动脉 ECs 表达出升高的 DNA 甲基转移酶 1 (DNMT1) 水平。用高葡萄糖处理和过表达 DNMT1 的 ECs 分离的外泌体的定量蛋白质组学显示,蛋白质水平和翻译后修饰都发生了显著变化,这些变化与 T2D 相关的血管功能一致。基于本体论和基因-功能-疾病相互作用分析,在高葡萄糖处理的 HUVECs 和 HFD 动物以及糖化血红蛋白水平较高的 T2D 个体中,与血管并发症相关的差异表达外泌体蛋白,如血栓素 1、Pentraxin3 和半胱氨酸蛋白酶抑制剂 C 等显著增加。用 5-Aza-2'-脱氧胞苷处理后,这些蛋白质的表达减少。我们的研究表明,T2D 相关血管并发症中外泌体蛋白质组的表观遗传调控。