Deletion of Ppard in CD11c+ cells attenuates atherosclerosis in ApoE knockout mice

Identification of potential biomarkers in cardiovascular calcification based on bioinformatics combined with single-cell RNA-seq and multiple machine learning analysis

BACKGROUND

The molecular and genetic mechanisms underlying vascular calcification remain unclear. This study aimed to determine the differences in calcification marker-related gene expression in macrophages.

METHODS

The expression profiling datasets GSE104140 and GSE235995 were analysed to identify differentially expressed genes (DEGs) between fibroatheroma with calcification and diffuse intimal thickening. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, Weighted Gene Co-expression Network Analysis (WGCNA), and Gene Set Enrichment Analysis (GSEA) were performed to assess functional characteristics. Hub genes were identified through a protein-protein interaction (PPI) network and machine learning approaches. Single-cell RNA sequencing data (GSE159677) validated the expression of calcification-related genes in macrophages, while Mendelian randomization analysis explored their potential causal relationship with coronary calcification. Further validation was conducted using enzyme-linked immunosorbent assay (ELISA) on coronary calcification samples and immunohistochemistry in ApoE-/- mice. Intravascular ultrasound was performed to assess coronary calcification severity.

RESULTS AND CONCLUSIONS

Two key biomarkers, ITGAX and MYD88, were identified as diagnostic indicators of cardiovascular calcification. Both biomarkers were significantly upregulated in calcified samples and were strongly associated with immune processes. Single-cell RNA sequencing confirmed their high expression in multiple immune cell types. Additionally, molecular docking analysis revealed that retinoic acid interacted with both biomarkers, suggesting potential therapeutic relevance. Immunohistochemical and ELISA analyses further validated their elevated expression in calcified samples. These findings provide novel insights into the molecular mechanisms of vascular calcification and highlight potential diagnostic and therapeutic targets.

Exome Sequencing Identified Susceptible Genes for High Residual Risks in Early-Onset Coronary Atherosclerotic Disease

AIMS

Despite the tremendous improvement in therapeutic medication and intervention for coronary atherosclerotic disease (CAD), residual risks remain. Exome sequencing enables identification of rare variants and susceptibility genes for residual risks of early-onset coronary atherosclerotic disease (EOCAD) with well-controlled conventional risk factors.

METHODS

We performed whole-exome sequencing of subjects who had no conventional risk factors, defined as higher body mass index, smoking, hypertension and dyslipidemia, screened from 1950 patients with EOCAD (age ≤ 45 years, at least 50% stenosis of coronary artery by angiography), and selected control subjects from 1006 elder (age ≥ 65 years) with < 30% coronary stenosis. Gene-based association analysis and clinical phenotypic comparison were conducted.

RESULTS

Subjects without defined conventional risk factors accounted for 4.72% of young patients. Totally, 6 genes might be associated with residual risk of EOCAD, namely CABP1 (OR = 22.19, p = 0.02), HLA-E (OR = 22.19, p = 0.02), TOE1 (OR = 33.6, p = 0.002), HPSE2 (OR = 11.1, p = 0.04), CHST14 (OR = 22.19, p = 0.02) as well as KLHL8 (OR = 22.19, p = 0.02). Phenotypic analysis displayed the levels of low-density lipoprotein cholesterol in carriers of mutations from CABP1, HLA-E, TOE1, and HPSE2 were significantly elevated compared to noncarriers. Notably, extracellular matrix-associated CHST14 and fibrinogen-associated KLHL8 both displayed possible correlation with increased neutrophil proportion and decreased monocyte percentage (both p < 0.05), exerting potential effects on the residual inflammatory risks of EOCAD.

CONCLUSION

The study identified six genes related to dyslipidemia and inflammation pathways with potential association with residual risk of EOCAD, which will contribute to precision-based prevention in these patients.

TRIAL REGISTRATION

The GRAND study was registered at www.

CLINICALTRIALS

gov on July 14, 2015, and the registry number is NCT02496858.

The Evolving Role of Dendritic Cells in Atherosclerosis

Atherosclerosis, a major contributor to cardiovascular morbidity and mortality, is characterized by chronic inflammation of the arterial wall. This inflammatory process is initiated and maintained by both innate and adaptive immunity. Dendritic cells (DCs), which are antigen-presenting cells, play a crucial role in the development of atherosclerosis and consist of various subtypes with distinct functional abilities. Following the recognition and binding of antigens, DCs become potent activators of cellular responses, bridging the innate and adaptive immune systems. The modulation of specific DC subpopulations can have either pro-atherogenic or atheroprotective effects, highlighting the dual pro-inflammatory or tolerogenic roles of DCs. In this work, we provide a comprehensive overview of the evolving roles of DCs and their subtypes in the promotion or limitation of atherosclerosis development. Additionally, we explore antigen pulsing and pharmacological approaches to modulate the function of DCs in the context of atherosclerosis.

Adipose-specific C-C motif chemokine ligand (CCL) 19 overexpression drives the mice to both insulin resistance and weight gain

INTRODUCTION

Enlarged adipose tissue is characterized by infiltration of activated immune cells and increased expression of chemokines recruiting these cells including C-C motif ligand 19 (CCL19), although the role of adipose CCL19 is still inconclusive.

RESEARCH DESIGN AND METHODS

Adipocyte-specific Ccl19 knock-in (KI) mice were generated, and the mice were fed either a normal diet or 40% or 60% fat diet (FD) to investigate the effects of CCL19 on the induction of inflammation and lipid metabolism.

RESULTS

Ccl19KI mice exhibited increased inflammatory signs in adipose tissue and enlarged subcutaneous white and brown adipose tissue than those of wild-type (WT) mice. The adipose tissue of Ccl19KI mice was characterized by increased extracellular signal-regulated kinase 1/2 and decreased AMP-activated protein kinase α phosphorylation. The protein expression of peroxisome proliferator-activated receptor γ coactivator 1α and uncoupling protein 1 was significantly reduced in brown adipose tissue of Ccl19KI mice compared with that in WT mice. The most remarkable changes between genotypes were observed in mice fed a 40% FD.

CONCLUSION

A 40% FD enhanced the effects of CCL19 overexpression, and these mice could be a suitable model to study metabolic disorders in overweight Asians.

Fa(c)t checking: How fatty acids shape metabolism and function of macrophages and dendritic cells

In recent years there have been major advances in our understanding of the role of free fatty acids (FAs) and their metabolism in shaping the functional properties of macrophages and DCs. This review presents the most recent insights into how cell intrinsic FA metabolism controls DC and macrophage function, as well as the current evidence of the importance of various exogenous FAs (such as polyunsaturated FAs and their oxidation products—prostaglandins, leukotrienes, and proresolving lipid mediators) in affecting DC and macrophage biology, by modulating their metabolic properties. Finally, we explore whether targeted modulation of FA metabolism of myeloid cells to steer their function could hold promise in therapeutic settings.

Immunogenetics of Atherosclerosis-Link between Lipids, Immunity, and Genes

PURPOSE OF REVIEW

Atherosclerosis is a complex disease process with lipid as a traditional modifiable risk factor and therapeutic target in treating atherosclerotic cardiovascular disease (ACVD). Recent evidence indicates that genetic influence and host immune response also are vital in this process. How these elements interact and modify each other and if immune response may emerge as a novel modifiable target remain poorly understood.

RECENT FINDINGS

Numerous preclinical studies have clearly demonstrated that hypercholesterolemia is essential for atherogenesis, but genetic variations and host immune-inflammatory responses can modulate the pro-atherogenic effect of elevated LDL-C. Clinical studies also suggest that a similar paradigm may also be operational in atherogenesis in humans. More importantly each element modifies the biological behavior of the other two elements, forming a triangular relationship among the three. Modulating any one of them will have downstream impact on atherosclerosis. This brief review summarizes the relationship among lipids, genes, and immunity in atherogenesis and presents evidence to show how these elements affect each other. Modulation of immune response, though in its infancy, has a potential to emerge as a novel clinical strategy in treating ACVD.