Transcriptomic analysis reveals the critical role of chemokine signaling in the anti-atherosclerosis effect of Xuefu Zhuyu decoction

Ethnopharmacological relevance

The process of atherosclerosis (AS) is complicated. Transcriptomics technology can assist in discovering the underlying mechanisms and exploring the key targets of Traditional Chinese Medicine (TCM) against atherosclerosis.

Aim

This study aimed to investigate targets and signaling pathways significantly related to AS and the potential intervention targets of Xuefu Zhuyu decoction by transcriptomics.

Materials and methods

AS models were established by subjecting ApoE^-/-mice to an 8-week high-fat diet. Structural changes and plaque formation in the aortic root were observed using hematoxylin-eosin staining (HE staining), while Oil Red O staining was employed to visualize lipid deposition within the aortic root plaque. Movat staining and immunohistochemical staining were conducted to examine the components present in the aortic root plaque. Macrophage content within the plaque was observed through immunofluorescence. Additionally, mRNA sequencing was performed on aortic tissues to identify differentially expressed genes. Enrichment analysis was performed using GO and KEGG analysis. Visualization of the protein-protein interaction (PPI) network was achieved using Cytoscape 3.7.1 and STRING. Western blotting (WB) was employed to assess the protein expression of major differentially expressed genes in the aortic tissue. The drug freeze-dried powder of Xuefu Zhuyu decoction was prepared and the RAW264.7 cells were induced by lipopolysaccharide (LPS) to build an in vitro model. Real-time quantitative PCR was employed to measure the mRNA expression of major differential genes.

Results

After ApoE^-/- mice were fed with an 8-week high-fat diet, observable changes included the thinning of the aortic root wall, the accumulation of foam cells within the plaque, and the formation of cholesterol crystals in the model group. Treatment with Xuefu Zhuyu (XFZY) decoction for 12 weeks significantly reduced the lipid deposition and the number of macrophages (P < 0.05) and significantly increased the collagen content within the plaque (P < 0.01). Enrichment analysis revealed a high enrichment of the Cytokine-cytokine receptor interaction pathway and Chemokine signaling pathway. Noteworthy genes involved in this response included Ccl12, Ccl22, Cx3cr1, Ccr7, Ccr2, Tnfrsf25, and Gdf5. Xuefu Zhuyu decoction significantly downregulated the expression of CX3CL1 and CX3CR1 (P < 0.05) and upregulated the expression of GDF5 (P < 0.01). Compared with control group, in cell models, the mRNA expressions of Ccl12, Ccl22, and Ccr2 were significantly upregulated (P < 0.05 or P < 0.01). Xuefu Zhuyu decoction significantly downregulated the expression of Ccl12, Ccl22, Cx3cr1, Ccr7 and Ccr2 (P < 0.05 or P < 0.01).

Conclusion

Xuefu Zhuyu decoction demonstrates effective regulation of plaque components, retarding plaque progression and preserving plaque stability by modulating lipid metabolism and inflammatory responses. Subsequent transcriptome analysis identified the Cytokine-cytokine receptor interaction and Chemokine signaling pathway as potential key pathways for the therapeutic effects of Xuefu Zhuyu decoction. This insight not only provides crucial avenues for further exploration into the mechanisms underlying Xuefu Zhuyu decoction but also offers valuable perspectives and hypotheses for enhancing disease prevention and treatment strategies.