Comparative Medical Research Institute, Experimental Animal Research Center, Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, No. 548 Binwen Road, Binjiang District, Hangzhou, 310053, China.
Lipids Health Dis. 2020 Mar 25;19(1):54. doi: 10.1186/s12944-020-01222-w.
Atherosclerosis is a major contributor to cardiovascular events, however, its molecular mechanism remains poorly known. Animal models of atherosclerosis can be a valuable tool to provide insights into the etiology, pathophysiology, and complications of atherosclerosis. In particular, Tibetan minipigs are a feasible model for studying diet-related metabolic and atherosclerotic diseases.
We used vascular transcriptomics to identify differentially expressed genes (DEGs) in high fat/cholesterol (HFC) diet-fed Tibetan minipig atherosclerosis models, analyzed the DEGs gene ontology (GO) terms, pathways and protein-protein interactions (PPI) networks, and identified hub genes and key modules using molecular complex detection (MCODE), Centiscape and CytoHubba plugin. The identified genes were validated using the human carotid atherosclerosis database (GSEA 43292) and RT-PCR methods.
Our results showed that minipigs displayed obvious dyslipidemia, oxidative stress, inflammatory response, atherosclerotic plaques, as well as increased low-density lipoprotein (LDL) and leukocyte recruitment after 24 weeks of HFC diet feeding compared to those under a regular diet. Our RNA-seq results revealed 1716 DEGs in the atherosclerotic/NC group, of which 1468 genes were up-regulated and 248 genes were down-regulated. Functional enrichment analysis of DEGs showed that the HFC diet-induced changes are related to vascular immune-inflammatory responses, lipid metabolism and muscle contraction, indicating that hypercholesterolemia caused by HFC diet can activate innate and adaptive immune responses to drive atherosclerosis development. Furthermore, we identified four modules from the major PPI network, which are implicated in cell chemotaxis, myeloid leukocyte activation, cytokine production, and lymphocyte activation. Fifteen hub genes were discovered, including TNF, PTPRC, ITGB2, ITGAM, VCAM1, CXCR4, TYROBP, TLR4, LCP2, C5AR1, CD86, MMP9, PTPN6, C3, and CXCL10, as well as two transcription factors (TF), i.e. NF-ĸB1 and SPI1. These results are consistent with the expression patterns in human carotid plaque and were validated by RT-PCR.
The identified DEGs and their enriched pathways provide references for the development and progression mechanism of Tibetan minipig atherosclerosis model induced by the HFC diet.
动脉粥样硬化是心血管事件的主要原因，但它的分子机制仍知之甚少。动脉粥样硬化的动物模型可以为研究动脉粥样硬化的病因、病理生理学和并发症提供有价值的工具。特别是，藏猪是研究饮食相关代谢和动脉粥样硬化疾病的可行模型。
我们使用血管转录组学来鉴定高脂肪/胆固醇（HFC）饮食喂养的藏猪动脉粥样硬化模型中的差异表达基因（DEGs），分析 DEGs 的基因本体（GO）术语、途径和蛋白质-蛋白质相互作用（PPI）网络，并使用分子复合物检测（MCODE）、Centiscape 和 CytoHubba 插件识别枢纽基因和关键模块。使用人类颈动脉粥样硬化数据库（GSEA 43292）和 RT-PCR 方法验证鉴定的基因。
我们的结果表明，与正常饮食组相比，经过 24 周 HFC 饮食喂养的藏猪表现出明显的血脂异常、氧化应激、炎症反应、动脉粥样硬化斑块以及低密度脂蛋白（LDL）和白细胞募集增加。我们的 RNA-seq 结果显示，在动脉粥样硬化/NC 组中有 1716 个 DEGs，其中 1468 个基因上调，248 个基因下调。DEGs 的功能富集分析表明，HFC 饮食诱导的变化与血管免疫炎症反应、脂质代谢和肌肉收缩有关，这表明 HFC 饮食引起的高胆固醇血症可以激活先天和适应性免疫反应，从而驱动动脉粥样硬化的发展。此外，我们从主要 PPI 网络中鉴定出四个模块，这些模块与细胞趋化、髓样白细胞激活、细胞因子产生和淋巴细胞激活有关。发现了 15 个枢纽基因，包括 TNF、PTPRC、ITGB2、ITGAM、VCAM1、CXCR4、TYROBP、TLR4、LCP2、C5AR1、CD86、MMP9、PTPN6、C3 和 CXCL10，以及两个转录因子（TF），即 NF-ĸB1 和 SPI1。这些结果与人类颈动脉斑块的表达模式一致，并通过 RT-PCR 得到验证。
鉴定的 DEGs 及其富集途径为 HFC 饮食诱导的藏猪动脉粥样硬化模型的发展和进展机制提供了参考。
