Qingre quyu granule stabilizes plaques through inhibiting the expression of tenascin-C in patients with severe carotid stenosis

Taoren Honghua Drug Attenuates Atherosclerosis and Plays an Anti-Inflammatory Role in ApoE Knock-Out Mice and RAW264.7 Cells

Taoren Honghua drug is a traditional Chinese medicinal drug used to treat cardiovascular disease. The aim of the study is to investigate the effects of Taoren Honghua drug on inflammation and atherosclerosis in ApoE knock-out mice and RAW264.7 cells. ApoE knock-out mice fed with high fat diet for 8 weeks were randomly divided into five groups and then continued the high fat diet, or plus Taoren Honghua drug at concentrations of 3.63, 1.815, and 0.9075 g/ml, or plus Simvastatin at 2.57 mg/kg. RAW 264.7 cells were intervened with lipopolysaccharide or lipopolysaccharide plus different concentrations of Taoren Honghua drug. Compared to mice only with high fat diet, mice with high fat diet and Taoren Honghua drug showed lower body weight, triglyceride, cholesterol, IL-6 and TNF-α, smaller plaque sizes, less lymph vessel, and T cell contents of lymph nodes, but higher IL-10 level. In RAW264.7 cells, groups with LPS plus Taoren Honghua drug had lower IL-6 and TNF-α, but higher IL-10 than LPS group, as revealed by PCR or ELISA methods. A decrease of total or phosphorylated ERK1/2, JNK, p38, ERK5, STAT3, and AKT were detected, so was the translocation of NF-κB p65 from nuclear to cytoplasm. These results suggested that Taoren Honghua drug could attenuate atherosclerosis and play an anti-inflammatory role via MAPKs, ERK5/STAT3, and AKT/NF-κB p65 signaling pathways in ApoE knock-out mice and lipopolysaccharide-induced RAW264.7 cells.

Tenascin-c renders a proangiogenic phenotype in macrophage via annexin II

Tenascin-c is an extracellular matrix glycoprotein, the expression of which relates to the progression of atherosclerosis, myocardial infarction and heart failure. Annexin II acts as a cell surface receptor of tenascin-c. This study aimed to delineate the role of tenascin-c and annexin II in macrophages presented in atherosclerotic plaque. Animal models with atherosclerotic lesions were established using ApoE-KO mice fed with high-cholesterol diet. The expression of tenascin-c and annexin II in atherosclerotic lesions was determined by qRT-PCR, Western blot and immunohistochemistry analysis. Raw 264.7 macrophages and human primary macrophages were exposed to 5, 10 and 15 μg/ml tenascin-c for 12 hrs. Cell migration as well as the proangiogenic ability of macrophages was examined. Additionally, annexin II expression was delineated in raw 264.7 macrophages under normal condition (20% O₂ ) for 12 hrs or hypoxic condition (1% O₂ ) for 6-12 hrs. The expression of tenascin-c and annexin II was markedly augmented in lesion aorta. Tenascin-c positively regulated macrophage migration, which was dependent on the expression of annexin II in macrophages. VEGF release from macrophages and endothelial tube induction by macrophage were boosted by tenascin-c and attenuated by annexin II blocking. Furthermore, tenascin-c activated Akt/NF-κB and ERK signalling through annexin II. Lastly, hypoxia conditioning remarkably facilitates annexin II expression in macrophages through hypoxia-inducible factor (HIF)-1α but not HIF-2α. In conclusion, tenascin-c promoted macrophage migration and VEGF expression through annexin II, the expression of which was modulated by HIF-1α.