TIM‑3 inhibits PDGF‑BB‑induced atherogenic responses in human artery vascular smooth muscle cells

Exploration of the Crucial Genes and Molecular Mechanisms Mediating Atherosclerosis and Abnormal Endothelial Shear Stress

Background

Abnormal endothelial shear stress (ESS) is a significant risk factor for atherosclerosis (AS); however, the genes and pathways between ESS and AS are poorly understood. Here, we screened hub genes and potential regulatory targets linked to the progression of AS induced by abnormal ESS.

Methods

The microarray data of ESS and AS were downloaded from the Gene Expression Omnibus (GEO) database. The coexpression modules related to shear stress and AS were identified with weighted gene coexpression network analysis (WGCNA). Coexpression genes in modules obtained from GSE28829 and GSE160611 were considered as SET1. The results were validated in validation set by differential gene analysis. The limma package in R was used to identify differentially expressed genes (DEGs). The common DEGs of GSE100927 and GSE103672 were regarded as SET2. Next, Gene Ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was conducted. Protein-protein interaction (PPI) enrichment analysis was assembled, and hub genes were identified using MCODE and ClueGO in Cytoscape. ROC curve analyses were conducted to assess the ability of common hub genes to distinguish samples of atherosclerotic plaque from normal arterial. The expression of common hub gene was verified in ox-LDL-induced foam cells and GSE41571.

Results

We identified three gene modules (the blue, tan, and cyan modules) related to AS and three shear stress-related modules (the brown, red, and pink modules). A total of 129 genes in SET1 and 476 genes in SET2 were identified. CCRL2, LGALS9, and PLCB2 were identified as common hub genes and validated in the GSE100927, GSE28829, and GSE41571. ROC analysis indicates the expression of CCRL2, LGALS9, and PLCB2 could effectively distinguish the atherosclerotic plaque and normal arterial. The expression level of CCRL2, LGALS9, and PLCB2 increases with the accumulation of lipid increased.

Conclusion

We identified CCRL2, LGALS9, and PLCB2 as key genes associated with abnormal ESS and AS and may provide potential prevention and treatment target of AS induced by abnormal ESS.

Shexiang Baoxin Pill Regulates Intimal Hyperplasia, Migration, and Apoptosis after Platelet-Derived Growth Factor-BB-Stimulation of Vascular Smooth Muscle Cells via miR-451

OBJECTIVE

To investigate the regulatory roles of Shexiang Baoxin Pill (SXBXW) in neointimal formation and vascular smooth muscle cells (VSMCs) invasion and apoptosis as well as the potential molecular mechanisms using cultured VSMCs model of vascular injury (platelet-derived growth factor (PDGF)-BB-stimulated) in vitro.

METHODS

VSMCs were randomly assigned to 5 groups: blank, PDGF-BB (20 ng/mL+ 0.1% DMSO), SXBXW-L (PDGF-BB 20 ng/mL + SXBXW low dose 0.625 g/L), SXBXW-M (PDGF-BB 20 ng/mL + SXBXW medium dose 1.25 g/L) and SXBXW-H (PDGF-BB 20 ng/mL+ SXBXW high dose 2.5 g/L) group. Cell proliferation was assessed using cell counting kit-8 (CCK-8) assay and bromodeoxyuridine (BrdU) incorporation assay, the migration effects were detected by Transwell assay, cell apoptosis rate was measured by the Annexin V/propidium iodide (PI) apoptosis kit. The markers of contractile phenotype of VSMCs were detected with immunofluorescent staining. To validate the effects of miR-451 in regulating proliferation, migration and apoptosis treated with SXBXW, miR-451 overexpression experiments were performed, the VSMCs were exposed to PDGF-BB 20 ng/mL + 0.1% DMSO and later divided into 4 groups: mimic-NC (multiplicity of infection, MOI=50), SXBXW (1.25 g/L) + mimic-NC, mimic-miR451 (MOI=50), and SXBXW (1.25 g/L) + mimic-miR451, and alterations of proteins related to the miR-451 pathway were analyzed using Western blot.

RESULTS

PDGF-BB induced VSMCs injury causes acceleration of proliferation and migration. SXBXW inhibited phenotypic switching, proliferation and migration and promoted cell apoptosis in PDGF-BB-induced VSMCs. In addition, miR-451 was shown to be down-regulated in the VSMCs following PDGF-BB stimulation. SXBXW treatment enhanced the expression of miR-451 in PDGF-BB-induced VSMCs (P<0.05). Compared with SXBXW + mimic-NC and mimic-miR451 groups, the expression of tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (Ywhaz) and p53 was further reduced in SXBXW + mimic-miR451 group, while activating transcription factor 2 (ATF2) was increased in VSMCs (P<0.05).

CONCLUSION

SXBXW regulated proliferation, migration and apoptosis via activation of miR-451 through ATF2, p53 and Ywhaz in PDGF-BB-stimulated VSMCs.

Phenotypic Changes of Peripheral γδ T Cell and Its Subsets in Patients With Coronary Artery Disease

Coronary atherosclerotic heart disease (CAD) is a chronic inflammatory cardiovascular disease with high morbidity and mortality. Growing data indicate that many immune cells are involved in the development of atherosclerosis. However, the immunological roles of γδ T cells in the initiation and progression of CAD are not fully understood. Here, we used flow cytometry to determine phenotypical changes of γδ T cells and their subpopulations in peripheral blood samples collected from 37 CAD patients. The Pearson correlation coefficient was used to analyze the relationship between the clinical parameter (serum LDL-C level) and the changes of immunophenotypes of γδ T cells. Our results demonstrated that the frequencies and absolute numbers of total γδ T cells and Vδ2⁺ T cells were significantly decreased in CAD patients when compared to healthy individuals. However, the proportion of Vδ1⁺ T cells was much lower in CAD patients than that of healthy individuals. Most importantly, a significant alteration of the Vδ1/Vδ2 ratio was found in CAD patients. In addition, a series of surface markers that are associated with costimulatory signals (CD28, CD40L, CD80, CD86), activation levels (CD69, CD25, HLA-DR), activating NK cell receptors (NKp30, NKp46, NKG2D) and inhibitory receptors (PD-1, CTLA-4, PD-1, Tim-3) were determined and then analyzed in the total γδ T cells, Vδ2⁺T cells and Vδ2^-T cells of CAD patients and healthy individuals. The data demonstrated that immunological activities of total γδ T cells, Vδ2⁺T cells, and Vδ2^-T cells of CAD patients were much lower than those in healthy individuals. Moreover, we found that there were positive correlations between the serum LDL-C levels and frequencies of CD3⁺γδ⁺ T cells, CD69⁺Vδ2⁺T cells, NKG2D⁺Vδ2⁺T cells, and NKp46⁺Vδ2⁺T cells. By contrast, there was an inverse correlation between the levels of serum LDL-C and the frequencies of CD69⁺Vδ2^-T cells and NKp46⁺Vδ2^-T cells. Accordingly, these findings could help us to better understand the roles of γδ T cells in the CAD, and shed light on the development of novel diagnostic techniques and therapeutic strategies by targeting γδ T cells for CAD patients.

Galectin-9: A Suppressor of Atherosclerosis?

It is no longer controversial that atherosclerosis is a vascular wall chronic inflammatory disease mediated by cells of innate and adaptive immunity. Galectin-9 (Gal-9) seems to be a crucial regulator of T-cell immunity by inducing apoptosis in specific T-cell subpopulations associated with autoimmunity and inflammatory disease. Accumulating evidence showed that galectin-9 signaling via T-cell immunoglobulin mucin 3 (TIM-3) is concerned with different regulatory functions in autoimmunity, including direct depletion of pro-inflammatory T-cells, expanding the number of regulatory T cells, altering macrophages to an anti-inflammatory state and the induction of repressive myeloid-derived suppressor cells. In addition, anti-Tim-3-Ab administration increased atherosclerotic plaque formation by blocking Tim-3–galectin-9 interaction. Hence, we hypothesize that galectin-9 may be a novel therapy for atherosclerotic disease. Further researches are needed to investigate the precise effect of galectin-9 in the process of atherosclerosis.