Atherosclerosis has long been recognized as an obey-driven disease, and thus therapeutic strategies have focused on lipid-lowering approaches. However, numerous studies have shown that inflammation has an essential role in the atherosclerotic process. The inflammatory nature of atherosclerosis implies that many potential targets can modulate atherosclerosis. Because atherosclerosis is a complicated, multitargeted, inflammatory-driven, chronic disease, its treatment relies on permanent drug administration. Therefore, there is a need to develop anti-inflammatory drugs with more novel, safe, and multi-targets13. Previously, ursodeoxycholic acid was used to prevent atherosclerosis in patients with nonalcoholic fatty liver disease14. Some studies have found that UDCA may exert anti-atherosclerosis activity by inhibiting intimal hyperplasia through resisting inflammation8–12. In our study, a comprehensive analysis was performed using a network pharmacology approach combined with gene expression profiling to identify further UDCA's potential mechanisms and therapeutic targets in carotid atherosclerosis.
Nine key target genes were identified by bioinformatics analysis as potential anti-HCC mechanisms by which UDCA antagonizes carotid atherosclerosis. Nine targets, including MMP9, CCL5, CD4, CCR2, CASP1, EGFR, PTPRC, SYK, and CD38, were significantly expressed in atherosclerotic plaques vascular tissues compared with normal controls. Nine central genes are broadly related to the positive regulation of lymphocyte proliferation, inflammatory response regulation, cytokine-mediated signaling pathways, transmembrane receptor protein tyrosine kinase signaling, and other biological processes. KEGG enrichment results showed that UDCA acted on carotid atherosclerosis by acting on core genes such as MMP9, CCL5, CD4, CCR2, and CASP1 enriched in the lipid and arteriosclerosis pathways, and cytokine-cytokine receptor interaction signaling pathways. Among them, the effect on CD4 is reflected in the non-canonical pathway. Most studies have demonstrated that chronic inflammation contributes centrally to the evolution and progression of atherosclerosis, which involves activating many inflammatory cytokines and chemokines. Inflammation can contribute to the transdifferentiation of vascular smooth muscle cells VSMC into macrophage-like cells15. MMP-9, produced by infiltrating macrophages and vascular smooth muscle cells VSMC, induces migration and proliferation of monocytes and smooth muscle cells (SMC)16–21 and affects overall plaque stability by promoting degradation of the extracellular matrix and NF-κB signaling pathways 22–25 thereby promoting fibrous plaque cap thinning26,27. MMP9 enhances the infiltrative density of inflammation, accelerates the damage of blood vessels, and modulates the movement of monocytes and T cells into the vessel wall28. Among the central genes, PTPRC (also known as CD45) and MMP9 have been demonstrated as inflammatory biomarkers of atherosclerosis29,30. Matrix metalloproteinase 9 (MMP-9) protein is predominantly found in the narrowest regions of human carotid plaques 31. Data mining of the human plaque transcriptome showed that CCL5 expression was higher in carotid arteries (23.3-fold increase) than in coronary plaques (2.9-fold increase)32. The chemokine CCL5 is secreted by activated platelets and is expressed in atherosclerotic plaques33,34. CCL5 is deposited on endothelial cells through interaction with specific chemokine receptors, thereby mediating the migration of inflammatory cells such as T cells and monocytes to the intima and promoting atherosclerosis35–37. In injured arteries, CCL5 (RANTES) is increased in Vessel wall cells and synergizes with leukocyte recruitment to damaged arteries during revascularization38,39. In addition, high RANTES expression in perivascular adipose tissue plays a significant function in mediating vascular inflammatory cell recruitment in endothelial dysfunction40,41. Relevant studies have demonstrated that activation and assembly of the inflammasome lead to self-cleavage and activation of caspase-1, which converts inactive pro-IL-1B and pro-IL-18 into active IL-1β and IL-18 by proteolysis42. To induce inflammation and promote the development of atherosclerosis43–46. Epilepsy It has been shown that cholesterol within the arterial wall triggers NLRP3 inflammasome-mediated activation of caspase-1. In the following, the release of mature IL-1 and IL-18, and IFN- will promote the development of atherosclerosis by altering the recruitment of monocytes to the lesion site, altering the activation state of diseased macrophages and the ability of these cells to form foam cells, and altering the activation state of other immune cells known to promote atherosclerosis, such as natural killer cells, T lymphocytes, and natural killer T cells47. Studies have confirmed that CCR2 is a useful marker of atherosclerosis48. CCR2 is a high-affinity receptor for CCL2 and is expressed on human endothelial cells49,50. The chemokine CCL2 mediates monocyte infiltration into atherosclerotic lesions through CC chemokine receptor 2 (CCR2)51 and plays a vital role in monocyte adhesion to the endothelium52. CCL2-CCR2 signaling through recruitment of inflammatory monocytes to atherosclerotic plaque sites53. It can also impair endothelial HDL uptake and cholesterol efflux and become a risk factor for atherosclerosis54.
In summary, UDCA may inhibit the development of inflammation mainly through inhibiting related proteins, chemokines, and chemokine receptors, thus playing a role in cervical atherosclerosis. In this study, we combined bioinformatics and network pharmacology approaches to elucidate the molecular mechanisms of UDCA in the treatment of carotid atherosclerosis. Hub genes involved in carotid atherosclerosis were searched for and identified using WGCNA and differential expression analysis. The regulatory network of drugs and hub genes was constructed, and the disease process in which the core genes are involved was further analyzed. The molecular docking method suggested that UDCA had a high binding affinity to the central target, validating the medicinal effect of UDCA. However, although the analysis results were able to identify a role involving UDCA in the treatment of carotid atherosclerosis, the data sources were limited to databases, and there was a lack of in vitro or in vivo experiments to further validate our results. In-depth basic and clinical studies and clinical studies are needed in future studies to elucidate the positive role of UDCA in slowing the progression of carotid atherosclerosis.
In conclusion, our study suggests that UDCA may act primarily on carotid atherosclerosis by influencing inflammatory processes. MMP9, CCL5, CASP1, CD4, and CCR2, may be critical potential target proteins of UDCA in treating carotid atherosclerosis. Additionally, molecular docking proved that the UDCA component docked well with the core protein, providing an essential basis for further study.