Functional association of a CD40 gene single-nucleotide polymorphism with the pathogenesis of coronary heart disease

Impact of the -1T>C single-nucleotide polymorphism of the CD40 gene on the development of endothelial dysfunction in a pro-diabetic microenvironment

BACKGROUND AND AIMS

Hyperglycemia reinforces pro-inflammatory conditions that enhance CD40 expression in endothelial cells (EC). Thymine to cytosine transition (-1T > C) in the promoter of the CD40 gene (rs1883832) further increases the abundance of CD40 protein on the EC surface. This study examines potential associations of the -1T > C SNP of the CD40 gene with type 1 (T1D) or type 2 (T2D) diabetes. Moreover, it investigates the impact of a pro-inflammatory diabetic microenvironment on gene expression in human cultured umbilical vein EC (HUVEC) derived from CC- vs. TT-genotype donors.

METHODS

Tetra-ARMS-PCR was used to compare genotype distribution in 252 patients with diabetes. Soluble CD40 ligand (sCD40L) and soluble CD40 receptor (sCD40) plasma levels were monitored using ELISA. RNA-sequencing was performed with sCD40L-stimulated CC- and TT-genotype HUVEC. Quantitative PCR, Western blot, multiplex-sandwich ELISA array, and immunocytochemistry were used to analyse changes in gene expression in these cells.

RESULTS

Homozygosity for the C-allele was associated with a significant 4.3-fold higher odds of developing T2D as compared to individuals homozygous for the T-allele. Inflammation and endothelial-to-mesenchymal transition (EndMT) driving genes were upregulated in CC-genotype but downregulated in TT-genotype HUVEC when exposed to sCD40L. Expression of EndMT markers significantly increased while that of endothelial markers decreased in HUVEC following exposure to hyperglycemia, tumour necrosis factor-α and sCD40L.

CONCLUSIONS

The -1T > C SNP of the CD40 gene is a risk factor for T2D. Depending on the genotype, it differentially affects gene expression in human cultured EC. CC-genotype HUVEC adopt a pro-inflammatory and intermediate EndMT-like phenotype in a pro-diabetic microenvironment.

Co-stimulators CD40-CD40L, a potential immune-therapy target for atherosclerosis: A review

The interaction between CD40 and CD40 ligand (CD40L) a crucial co-stimulatory signal for activating adaptive immune cells, has a noteworthy role in atherosclerosis. It is well-known that atherosclerosis is linked to immune inflammation in blood vessels. In atherosclerotic lesions, there is a multitude of proinflammatory cytokines, adhesion molecules, and collagen, as well as smooth muscle cells, macrophages, and T lymphocytes, particularly the binding of CD40 and CD40L. Therefore, research on inhibiting the CD40-CD40L system to prevent atherosclerosis has been ongoing for more than 30 years. However, it's essential to note that long-term direct suppression of CD40 or CD40L could potentially result in immunosuppression, emphasizing the critical role of the CD40-CD40L system in atherosclerosis. Thus, specifically targeting the CD40-CD40L interaction on particular cell types or their downstream signaling pathways may be a robust strategy for mitigating atherosclerosis, reducing potential side effects. This review aims to summarize the potential utility of the CD40-CD40L system as a viable therapeutic target for atherosclerosis.

Potential role of soluble CD40 receptor in chronic inflammatory diseases

The CD40 receptor and its ligand CD154 are widely expressed in various immune-competent cells. Interaction of CD154 with CD40 is essential for B-cell growth, differentiation, and immunoglobulin class switching. Many other immune-competent cells involved in innate and adaptive immunity communicate through this co-stimulatory ligand-receptor dyad. CD40-CD154 interaction is involved in the pathogenesis of numerous inflammatory and autoimmune diseases. While CD40 and CD154 are membrane-bound proteins, their soluble counterparts are generated by proteolytic cleavage or alternative splicing. This review summarises current knowledge about the impact of single nucleotide polymorphisms in the human CD40 gene and compensatory changes in the plasma level of the soluble CD40 receptor (sCD40) isoform in related pro-inflammatory diseases. It discusses regulation patterns of the disintegrin metalloprotease ADAM17 function leading to ectodomain shedding of transmembrane proteins, such as pro-inflammatory adhesion molecules or CD40. The role of sCD40 as a potential biomarker for chronic inflammatory diseases will also be discussed.

Ectodomain Shedding by ADAM17 Increases the Release of Soluble CD40 from Human Endothelial Cells under Pro-Inflammatory Conditions

BACKGROUND

Homozygosity for the C allele of the -1T>C single nucleotide polymorphism (SNP) of the CD40 gene (rs1883832) is associated with susceptibility to coronary heart disease (CHD), enhanced CD40 expression, and shedding. The disintegrin metalloprotease ADAM17 can cleave various cell surface proteins. This study investigates an association between ADAM17-mediated CD40 shedding and inflammation in CC genotype human endothelial cells.

METHODS

Human umbilical vein endothelial cells (HUVEC) carrying the CC genotype were stimulated with soluble CD40 ligand (sCD40L) or tumor necrosis factor-α (TNFα). Messenger RNA and protein expression were determined with standard methods. Levels of high sensitive c-reactive protein (hs-CRP), interleukin-6 (IL-6), and sCD40 in plasma samples from patients with CHD were assessed using ELISA.

RESULTS

ADAM17 surface abundance was elevated following stimulation with CD40L and TNFα just as its regulator iRhom2. Inhibition of ADAM17 prevented TNFα-induced sCD40 and soluble vascular cell adhesion molecule-1 release into the conditioned medium and reinforced CD40 surface abundance. Secondary to inhibition of ADAM17, stimulation with CD40L or TNFα upregulated monocyte chemoattractant protein-1 mRNA and protein. Levels of sCD40 and the inflammatory biomarkers hs-CRP and IL-6 were positively correlated in the plasma of patients with CHD.

CONCLUSIONS

We provide a mechanism by which membrane-bound CD40 is shed from the endothelial cell surface by ADAM17, boosting sCD40 formation and limiting downstream CD40 signaling. Soluble CD40 may represent a robust biomarker for CHD, especially in conjunction with homozygosity for the C allele of the -1T>C SNP of the CD40 gene.

Genetics and epigenetics of autoimmune thyroid diseases: Translational implications

Hashimoto's thyroiditis (HT) and Graves' disease (GD) are prevalent autoimmune disorders, representing opposite ends of the clinical spectrum of autoimmune thyroid diseases (AITD). The pathogenesis involves a complex interplay between environment and genes. Specific susceptibility genes have been discovered that predispose to AITD, including thyroid-specific and immune-regulatory genes. Growing evidence has revealed that genetic and epigenetic variants can alter autoantigen presentation during the development of immune tolerance, can enhance self-peptide binding to MHC (major histocompatibility complex), and can amplify stimulation of T- and B-cells. These gene-driven mechanistic discoveries lay the groundwork for novel treatment targets. This review summarizes recent advances in our understanding of key AITD susceptibility genes (Tg¹, TSHR, HLA-DR3, and CD40) and their translational therapeutic potential.

Role of CD40 ligand-mediated endothelial cell-monocyte interaction at atherosclerosis predilection sites

BACKGROUND

Monocyte recruitment into the vessel wall at atherosclerosis predilection sites is essential for lesion development in the early phase of atherosclerosis. Platelets interacting with ultra-large von Willebrand Factor (ULVWF) multimers deposited after CD40 receptor ligation on the endothelial surface form adhesive bridges and facilitate monocyte diapedesis. We hypothesise that enhanced endothelial CD40 expression at arterial bifurcations is responsible for monocyte recruitment and that its absence reduces susceptibility to atherosclerosis.

METHODS

Y-shaped channel slides covered with endothelial cells (HUVEC) and isolated perfused carotid artery bifurcations from different mouse lines were used for adhesion studies with isolated fluorescent dye-labelled platelets and monocytes. Monocyte adherence was quantified via fluorescence imaging. Oil Red O staining visualised aortic atherosclerotic plaques, and mRNA expression was determined by qRT-PCR.

RESULTS

In response to soluble CD40 ligand (sCD40L) stimulated ULVWF release, the number of monocytes bound distal to the bifurcation of the Y-slide was 1.8-fold greater than without stimulation. The number of adherent monocytes in sCD40L-treated carotid artery bifurcations was 6 to 12.3-fold greater in ApoE knockout mice as compared to bifurcations derived from CD40/ApoE-deficient or control mice. CD40 mRNA expression was 2-fold higher in carotid artery bifurcations of ApoE knockout mice as compared to the proximal unbranched segment. Introduction of the CD40 knockout into the ApoE^-/- background reduced the atherosclerosis burden along the entire aorta of these mice by 60 %.

CONCLUSIONS

Our data demonstrate the importance of endothelial CD40 expression at atherosclerosis predilection sites for endothelial cell-platelet-monocyte interaction in the early phase of atherosclerosis.

Causal associations between CD40/CD40L and aortic diseases: A mendelian randomization study

Background: CD40 and CD40L have been reported as associated with aortic dissection (AD) and aortic aneurysm (AA), but the causality of the associations has not been established yet.

Methods: We conducted a two-sample Mendelian randomization (MR) study to assess the causal inference between CD40/CD40L and aortic diseases including AD and AA. The instrumental variables (IVs) for CD40 and CD40L were selected from a high-quality protein quantitative trait loci dataset released by a genomic study involving 30,931 individuals of European ancestry. The genome-wide association studies summary statistics for AD and AA were from the FinnGen Release 7, with 288638 controls for all outcomes of interests, 680 cases for AD and 6,092 cases for AA, also from European ancestry. For AA subtypes, there were 5,881 cases of thoracic AA (TAA) and 2,434 cases of abdominal AA (AAA) respectively. Inverse-variance weighted and Wald ratio were applied for calculating causal estimates. Horizontal pleiotropy and heterogeneity were assessed using MR-Egger regression analysis and Cochran Q test, respectively. Leave-one-out analyses were further performed.

Results: Three single-nucleotide polymorphisms (SNPs) for CD40 and one SNP for CD40L were selected as IVs. We found genetic proxied CD40 levels inversely associated with the risk of AD (odds ratio [OR]: 0.777, 95% confidence interval [CI]: 0.618–0.978, p = 0.031) and AA (OR: 0.905, 95% CI: 0.837–0.978, p = 0.012), consistent across TAA (both p < 0.050). There were trends of increased risks of AD and AA in the presence of CD40L while not reaching statistical significance. No significant horizontal pleiotropy or heterogeneity was observed.

Conclusion: Our MR study provides evidence supporting the causal association between CD40 and the reduced risks of both AD and AA.

Translational enhancement by base editing of the Kozak sequence rescues haploinsufficiency

A variety of single-gene human diseases are caused by haploinsufficiency, a genetic condition by which mutational inactivation of one allele leads to reduced protein levels and functional impairment. Translational enhancement of the spare allele could exert a therapeutic effect. Here we developed BOOST, a novel gene-editing approach to rescue haploinsufficiency loci by the change of specific single nucleotides in the Kozak sequence, which controls translation by regulating start codon recognition. We evaluated for translational strength 230 Kozak sequences of annotated human haploinsufficient genes and 4621 derived variants, which can be installed by base editing, by a high-throughput reporter assay. Of these variants, 149 increased the translation of 47 Kozak sequences, demonstrating that a substantial proportion of haploinsufficient genes are controlled by suboptimal Kozak sequences. Validation of 18 variants for 8 genes produced an average enhancement in an expression window compatible with the rescue of the genetic imbalance. Base editing of the NCF1 gene, whose monoallelic loss causes chronic granulomatous disease, resulted in the desired increase of NCF1 (p47phox) protein levels in a relevant cell model. We propose BOOST as a fine-tuned approach to modulate translation, applicable to the correction of dozens of haploinsufficient monogenic disorders independently of the causing mutation.

Targeting cytokines and immune checkpoints in atherosclerosis with monoclonal antibodies

Over the past fifteen years, treatments using monoclonal antibodies specifically targeting cytokines have been developed to treat chronic inflammatory diseases, including rheumatoid arthritis or psoriasis, both associated with increased cardiovascular risk. The cardiovascular impact of these therapies allows us to validate the clinical relevance of the knowledge acquired from experimental studies about the role of cytokines in atherosclerosis. Several clinical studies have confirmed the protective effects of anti-TNFα and anti-IL-6R monoclonal antibodies against athero-thrombotic cardiovascular risk in patients with chronic inflammatory diseases. Yet, caution is needed since anti-TNFα treatment can aggravate chronic heart failure. More recently, the CANTOS study showed for the first time that an anti-inflammatory treatment using anti-IL-1β monoclonal antibody in coronary artery disease patients significantly reduced cardiovascular events. The effects of IL-23/IL-17 axis blockade on cardiovascular risk in patients with psoriasis or arthritis remain controversial. Several monoclonal antibodies targeting costimulatory molecules have also been developed, a direct way to confirm their involvement in atherothrombotic cardiovascular diseases. Blocking the CD28^-CD80/86 axis with Abatacept has been shown to reduce cardiovascular risk. In contrast, the treatment of cancer patients with antibodies blocking immune checkpoint inhibitory receptors, such as CTLA-4, PD1, or PDL1, could worsen the risk of atherothrombotic events. In the future, cardiologists will be increasingly solicited to assess the cardiovascular risk of patients suffering from chronic inflammatory diseases or cancer and participate in choosing the most appropriate treatment. At the same time, immunomodulatory approaches directly targeting cardiovascular diseases will be developed as a complement to the usual treatment strategies.

The effect of CYP7B1 polymorphisms on the risk of coronary heart disease in Hainan Han population

Background

Coronary heart disease (CHD) is the leading cause of human death worldwide. Genetic factors play an important role in the occurrence of CHD. Our study is designed to investigate the influence of CYP7B1 polymorphisms on CHD risk.

Methods

In this case–control study, 508 CHD patients and 510 healthy individuals were recruited to determine the correlation between CYP7B1 polymorphisms (rs7836768, rs6472155, and rs2980003) and CHD risk. The associations were evaluated by computing odds ratios (OR) and 95% confidence intervals (CI) with logistic regression analysis. The association between SNP-SNP interaction and CHD susceptibility was carried out by multifactor dimensionality reduction analyses.

Results

Our study found that rs6472155 is significantly associated with an increased risk of CHD in age > 60 years (OR 2.20, 95% CI = 1.07–4.49, p = 0.031), women (OR 3.17, 95% CI = 1.19–8.44, p = 0.021), and non-smokers (3.43, 95% CI = 1.16–10.09, p = 0.025). Rs2980003 polymorphism has a lower risk of CHD in drinkers (OR 0.47, 95% CI = 0.24–0.91, p = 0.025). Further analyses based on false-positive report probability validated these significant results. Besides, it was found that rs6472155 polymorphism was associated with uric acid level (p = 0.034).

Conclusion

Our study indicated that CYP7B1 polymorphisms are related to the risk of CHD, which provides a new perspective for prevent of CHD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-01067-x.

A functional variant of the long noncoding RNA AL110200 is associated with the risk of ischaemic stroke recurrence

BACKGROUND AND PURPOSE

This study aimed to test the hypothesis that long noncoding RNA (lncRNA) AL110200 exerts a proinflammatory effect on atherosclerosis and that the variant rs901681 contributes to ischaemic stroke incidence and recurrence.

METHODS

The expression of AL110200 was analyzed in THP-1 cells treated with oxidized low-density lipoprotein and in human peripheral blood in a coronary heart disease and control population to determine the role of AL110200 in atherosclerosis. The effect of AL110200 on cell adhesion and invasion was tested. The plasma level of leukotriene B4 and rs901681 genotype distribution were assessed in 220 participants. In 1004 ischaemic stroke patients and 1434 controls, the association between rs901681 and stroke incidence was analyzed by logistic regression, and the association of rs901681 and stroke prognosis was analyzed using Kaplan-Meier analysis and the Cox proportional hazards model.

RESULTS

Increased expression of AL110200 was observed in THP-1 cells under oxidized low-density lipoprotein treatment. Knockdown of AL110200 reduced the adhesive and invasive ability of THP-1 cells. AL110200 expression in peripheral blood was significantly higher in the coronary heart disease group than in the controls. The GG genotype of rs901681 is associated with reduced plasma leukotriene B4. In the ischaemic stroke population, rs901681 was not associated with ischaemic stroke incidence (p = 0.686). Patients carrying rs901681 GG had a lower risk for stroke recurrence at age ≥60 years (p = 0.001), cardiovascular stroke death (p = 0.022) and all-cause mortality (p = 0.034) in the all-age group.

CONCLUSIONS

AL110200 might exert a proinflammatory effect on atherosclerosis, and the variant rs901681 might be a strong predictor of stroke prognosis in ischaemic stroke patients.

COMP (Cartilage Oligomeric Matrix Protein) Neoepitope: A Novel Biomarker to Identify Symptomatic Carotid Stenosis

OBJECTIVE

COMP (cartilage oligomeric matrix protein) is abundantly expressed in the cardiovascular system, cartilage, and atherosclerotic plaques. We investigated if the total COMP (COMPtotal) and COMP neoepitope (COMPneo) with other cardiovascular markers and clinical parameters could identify symptomatic carotid stenosis. Approach and Results: Blood samples were collected from patients with symptomatic carotid stenosis (stenosis, n=50), patients with stroke without carotid stenosis but small plaques (plaque, n=50), and control subjects (n=50). COMPtotal and COMPneo were measured using an ELISA. Ninety-two cardiovascular disease markers were measured by the Olink CVD kit. The presence of native COMP and COMPneo was determined by immunohistochemistry. The concentration of COMPneo was higher and COMPtotal was lower in the stenosis group. When the concentration was compared between the stenosis and control groups, IL-1ra (interleukin-1 receptor antagonist protein), IL6 (interleukin-6), REN (Renin), MMP1 (matrix metalloproteinase-1), TRAIL-R2 (tumor necrosis factor-related apoptosis-inducing ligand receptor 2), ITGB1BP2 (integrin beta 1 binding protein 2), and COMPneo were predictive of stenosis. Conversely, KLK6 (kallikrein-6), COMPtotal, NEMO (nuclear factor-kappa-B essential modulator), SRC (Proto-oncogene tyrosine-protein kinase Src), SIRT2 (SIR2-like protein), CD40 (cluster of differentiation 40), TF (tissue factor), MP (myoglobin), and RAGE (receptor for advanced glycation end-products) were predictive of the control group. Model reproducibility was good with the receiver operating characteristic plot area under the curve being 0.86. When comparing the plaque group and stenosis group, COMPneo, GAL (galanin), and PTX3 (pentraxin-related protein PTX3) were predictive of stenosis. Model reproducibility was excellent (receiver operating characteristic plot area under the curve 0.92). COMPneo was detected in smooth muscle-, endothelial-, and foam-cells in carotid stenosis.

CONCLUSIONS

Degradation of COMP may be associated with atherosclerosis progression and generation of a specific COMP fragment-COMPneo. This may represent a novel biomarker that together with COMPtotal and other risk-markers could be used to identify symptomatic carotid stenosis. Graphic Abstract: A graphic abstract is available for this article.

CD40/CD40L and Related Signaling Pathways in Cardiovascular Health and Disease-The Pros and Cons for Cardioprotection

The CD40–CD40 ligand (CD40L) dyad represents a scientific and clinical field that has raised many controversies in the past and cannot be clearly defined as being an either beneficial or harmful pathway. Being crucially involved in physiological immunological processes as well as pathological inflammatory reactions, the signaling pathway has been recognized as a key player in the development of both autoimmune and cardiovascular disease. Even though the possibilities of a therapeutic approach to the dyad were recognized decades ago, due to unfortunate events, detailed in this review, pharmacological treatment targeting the dyad, especially in patients suffering from atherosclerosis, is not available. Despite the recent advances in the treatment of classical cardiovascular risk factors, such as arterial hypertension and diabetes mellitus, the treatment of the associated low-grade inflammation that accounts for the progression of atherosclerosis is still challenging. Low-grade inflammation can be detected in a significant portion of patients that suffer from cardiovascular disease and it is therefore imperative to develop new therapeutic strategies in order to combat this driver of atherosclerosis. Of note, established cardiovascular drugs such as angiotensin-converting enzyme inhibitors or statins have proven beneficial cardiovascular effects that are also related to their pleiotropic immunomodulatory properties. In this review, we will discuss the setbacks encountered as well as new avenues discovered on the path to a different, inflammation-centered approach for the treatment of cardiovascular disease with the CD40–CD40L axis as a central therapeutic target.

The CD40-CD40L Dyad as Immunotherapeutic Target in Cardiovascular Disease

Chronic inflammation drives the development of atherosclerosis. Despite optimal treatment of classical cardiovascular risk factors, a substantial portion of the population has elevated inflammatory biomarkers and develops atherosclerosis-related complications, indicating that a residual inflammatory risk drives atherosclerotic cardiovascular disease in these patients. Additional anti-inflammatory therapeutic strategies are therefore required. The co-stimulatory molecule CD40 and its ligand CD40L (CD154) have a central role in the regulation of the inflammatory response during the development of atherosclerosis by modulating the interaction between immune cells and between immune cells and non-immune cells. In this review, we discuss the role of the CD40-CD40L dyad in atherosclerosis, and we discuss recent studies on the therapeutic potential of novel CD40-CD40L targeting strategies in cardiovascular medicine.