Relationship between CCL22 Expression by Vascular Smooth Muscle Cells and Macrophage Histamine Receptors in Atherosclerosis

Screening of potential regulatory genes in carotid atherosclerosis vascular immune microenvironment

BACKGROUND

Immune microenvironment is one of the essential characteristics of carotid atherosclerosis (CAS), which cannot be reversed by drug therapy alone. Thus, there is a pressing need to develop novel immunoregulatory strategies to delay this pathological process that drives cardiovascular-related diseases. This study aimed to detect changes in the immune microenvironment of vascular tissues at various stages of carotid atherosclerosis, as well as cluster and stratify vascular tissue samples based on the infiltration levels of immune cell subtypes to distinguish immune phenotypes and identify potential hub genes regulating the immune microenvironment of carotid atherosclerosis.

MATERIALS AND METHODS

RNA sequencing datasets for CAS vascular tissue and healthy vascular tissue (GSE43292 and GSE28829) were downloaded from the Gene Expression Omnibus (GEO) database. To begin, the immune cell subtype infiltration level of all samples in both GSE43292 and GSE28829 cohorts was assessed using the ssGSEA algorithm. Following this, consensus clustering was performed to stratify CAS samples into different clusters. Finally, hub genes were identified using the maximum neighborhood component algorithm based on the construction of interaction networks, and their diagnostic efficiency was evaluated.

RESULTS

Compared to the controls, a higher number of immune cell subtypes were enriched in CAS samples with higher immune scores in the GSE43292 cohort. Advanced CAS was characterized by high immune cell infiltration, whereas early CAS was characterized by low immune cell infiltration in the GSE28829 cohort. Moreover, CAS progression may be related to the immune response pathway. Biological processes associated with muscle cell development may impede the progression of CAS. Finally, the hub genes PTPRC, ACTN2, ACTC1, LDB3, MYOZ2, and TPM2 had satisfactory efficacy in the diagnosis and prediction of high and low immune cell infiltration in CAS and distinguishing between early and advanced CAS samples.

CONCLUSION

The enrichment of immune cells in vascular tissues is a primary factor driving pathological changes in CAS. Additionally, CAS progression may be related to the immune response pathway. Biological processes linked to muscle cell development may delay the progression of CAS. PTPRC, ACTN2, ACTC1, LDB3, MYOZ2, and TPM2 may regulate the immune microenvironment of CAS and participate in the occurrence and progression of the disease.

Structural basis of ligand recognition and activation of the histamine receptor family

Histamine is a biogenic amine that is critical in various physiological and pathophysiological processes, including but not limited to allergic reactions, wakefulness, gastric acid secretion and neurotransmission. Here, we determine 9 cryo-electron microscopy (cryo-EM) structures of the 4 histamine receptors in complex with four different G protein subtypes, with endogenous or synthetic agonists bound. Inside the ligand pocket, we identify key motifs for the recognition of histamine, the distinct binding orientations of histamine and three subpockets that facilitate the design of specific ligands. In addition, we also identify key residues responsible for the selectivity of immethridine. Moreover, we reveal distinct structural features as determinants of Gq vs. Gs or Gs vs. Gi coupling differences among the histamine receptors. Our study provides a structural framework for understanding the ligand recognition and G protein coupling of all 4 histamine receptors, which may facilitate the rational design of ligands targeting these receptors.

Blocking H1R signal aggravates atherosclerosis by promoting inflammation and foam cell formation

Atherosclerosis (AS) is a chronic inflammatory arterial disease, in which abnormal lipid metabolism and foam cell formation play key roles. Histamine is a vital biogenic amine catalyzed by histidine decarboxylase (HDC) from L-histidine. Histamine H1 receptor (H1R) antagonist is a commonly encountered anti-allergic agent in the clinic. However, the role and mechanism of H1R in atherosclerosis have not been fully elucidated. Here, we explored the effect of H1R on atherosclerosis using Apolipoprotein E-knockout (ApoE-/-) mice with astemizole (AST, a long-acting H1R antagonist) treatment. The results showed that AST increased atherosclerotic plaque area and hepatic lipid accumulation in mice. The result of microarray study identified a significant change of endothelial lipase (LIPG) in CD11b+ myeloid cells derived from HDC-knockout (HDC-/-) mice compared to WT mice. Blocking H1R promoted the formation of foam cells from bone marrow-derived macrophages (BMDMs) of mice by up-regulating p38 mitogen-activated protein kinase (p38 MAPK) and LIPG signaling pathway. Taken together, these findings demonstrate that blocking H1R signal aggravates atherosclerosis by promoting abnormal lipid metabolism and macrophage-derived foam cell formation via p38 MAPK-LIPG signaling pathway. KEY MESSAGES: Blocking H1R signal with AST aggravated atherosclerosis and increased hepatic lipid accumulation in high-fat diet (HFD)-fed ApoE-/- mice. Blocking H1R signal promoted macrophage-derived foam cell formation via p38 MAPK-LIPG signaling pathway.

Association of troponin I and macrophages in cardiac tamponade with Stanford type A aortic dissection

Background

Acute aortic dissection has a high mortality rate, especially for Stanford type A with a dissected ascending aorta. Cardiac tamponade is one of the most common complications of acute type A aortic dissection (ATAAD) and can cause death. However, the pathogenesis is often unclear. We aimed to examine laboratory findings at the onset of disease and macrophage involvement.

Methods

Hematological and biochemical parameters, and D-dimer, brain natriuretic peptide (BNP), and high-sensitivity troponin I (hs-cTnI) levels in 70 patients with ATAAD at our hospital were investigated. Additionally, the myocardium and aorta after autopsy of an ATAAD case with cardiac tamponade were pathologically examined.

Results

Forty-four ATAAD cases were complicated by cardiac tamponade. The mean age of patients with cardiac tamponade and proportion of patients over 70 years of age were both significantly higher than for those without cardiac tamponade. Evaluable D-dimer values were higher than 0.5 μg/mL in all patients. Significantly elevated laboratory parameters in patients with cardiac tamponade included: lactate dehydrogenase, aspartate aminotransferase, C-reactive protein, lactate, BNP, and hs-cTnI. However, multivariate analysis showed only hs-cTnI was significantly associated with cardiac tamponade. Histological examination revealed numerous M2-like macrophages infiltrating the myocardium and dissecting aorta, expressing CC chemokine ligand (CCL)2 together with vascular endothelial growth factor-C and matrix metalloproteinase-9. The peripheral monocyte-to-neutrophil ratio (MNR) was also significantly higher in cardiac tamponade.

Conclusions

In ATAAD patients with cardiac tamponade, hs-cTnI was significantly elevated and CCL2 expression was observed, which may be involved in the expression of M2-like macrophages via an increased MNR.

The Microenvironment That Regulates Vascular Wall Stem/Progenitor Cells in Vascular Injury and Repair

Vascular repair upon injury is a frequently encountered pathology in cardiovascular diseases, which is crucial for the maintenance of arterial homeostasis and function. Stem/progenitor cells located on vascular walls have multidirectional differentiation potential and regenerative ability. It has been demonstrated that stem/progenitor cells play an essential role in the basic medical research and disease treatment. The dynamic microenvironment around the vascular wall stem/progenitor cells (VW-S/PCs) possesses many stem cell niche-like characteristics to support and regulate cells' activities, maintaining the properties of stem cells. Under physiological conditions, vascular homeostasis is a cautiously balanced and efficient interaction between stem cells and the microenvironment. These interactions contribute to the vascular repair and remodeling upon vessel injury. However, the signaling mechanisms involved in the regulation of microenvironment on stem cells remain to be further elucidated. Understanding the functional characteristics and potential mechanisms of VW-S/PCs is of great significance for both basic and translational research. This review underscores the microenvironment-derived signals that regulate VW-S/PCs and aims at providing new targets for the treatment of related cardiovascular diseases.

​Circulating Cytokines in Myocardial Infarction Are Associated With Coronary Blood Flow

Background

The level of systemic inflammation correlates with the severity of the clinical course of acute myocardial infarction (AMI). It has been shown that circulating cytokines and endothelial dysfunction play an important role in the process of clot formation. The aim of our study was to assess the concentration of various circulating cytokines, endothelial function and blood clotting in AMI patients depending on the blood flow through the infarction-related artery (IRA).

Methods

We included 75 patients with AMI. 58 presented with ST-elevation myocardial infarction (STEMI) and 17 had non-ST-elevation myocardial infarction (non-STEMI). A flow-mediated dilation test (FMD test), thrombodynamics and rotational thromboelastometry as well as assessment of 14 serum cytokines using xMAP technology were performed.

Findings

Non-STEMI-patients were characterized by higher levels of MDC, MIP-1β, TNF-α. Moreover, we observed that patients with impaired blood flow through the IRA (TIMI flow 0-1) had higher average and initial clot growth rates, earlier onset of spontaneous clots, C-reactive protein (CRP) and IL-10 compared to patients with preserved blood flow through the IRA (TIMI flow 2-3). Patients with TIMI 2-3 blood flow had higher level of IP-10. IL-10 correlated with CRP and pro-inflammatory cytokines levels, initial clot growth rate and clot lysis time in TIMI 0-1 patients. All these differences were statistically significant.

Interpretation

We demonstrated that concentrations of the inflammatory cytokines correlate not only with the form of myocardial infarction (STEMI or non-STEMI), but also with the blood flow through the infarct-related artery. Inflammatory response, functional state of endothelium, and clot formation are closely linked with each other. A combination of these parameters affects the patency of the infarct-related artery.

Differential Proteomics of Cardiovascular Risk and Coronary Artery Disease in Humans

Background

Proteomics of atypical phenotypes may help unravel cardiovascular disease mechanisms.

Aim

We aimed to prospectively screen the proteome of four types of individuals: with or without coronary artery disease (CAD), each with or without multiple risk factors. Associations with individual risk factors and circulating biomarkers were also tested to provide a functional context to the protein hits.

Materials and Methods

The CAPIRE study (ClinicalTrials.gov Identifier: NCT02157662) is a cross-sectional study aimed at identifying possible new mechanisms promoting or protecting against atherothrombosis. Quantification (by aptamer technology), ranking (using partial least squares), and correlations (by multivariate regression) of ~5000 plasma proteins were performed in consecutive individuals aged 45–75 years, without previous cardiovascular disease, undergoing computed tomography angiography for suspected CAD, showing either >5/16 atherosclerotic segments (CAD+) or completely clean arteries (CAD−) and either ≤ 1 risk factor (RF+) or ≥3 risk factors (RF−) (based on history, blood pressure, glycemia, lipids, and smoking).

Results

Of 544 individuals, 39% were atypical (93 CAD+/RF−; 120 CAD−/RF+) and 61% typical (102 CAD+/RF+; 229 CAD−/RF−). In the comparison with CAD+/RF− adjusted for sex and age, CAD−/RF+ was associated with increased atrial myosin regulatory light chain 2 (MYO) and C-C motif chemokine-22 (C-C-22), and reduced protein shisa-3 homolog (PS-3) and platelet-activating factor acetylhydrolase (PAF-AH). Extending the analysis to the entire cohort, an additional 8 proteins were independently associated with CAD or RF; by logistic regression, the 12-protein panel alone discriminated the four groups with AUCROC's of 0.72–0.81 (overall p = 1.0e−38). Among them, insulin-like growth factor binding protein-3 is positively associated with RF, lower BMI, and HDL-cholesterol, renin with CAD higher glycated hemoglobin HbA1c, and smoking.

Conclusions

In a CCTA-based cohort, four proteins, involved in opposing vascular processes (healing vs. adverse remodeling), are specifically associated with low CAD burden in high CV-risk individuals (high MYO and C-C-22) and high CAD burden in low-risk subjects (high PS-3 and PAF-AH), in interaction with BMI, smoking, diabetes, HDL-cholesterol, and HbA1c. These findings could contribute to a deeper understanding of the atherosclerotic process beyond traditional risk profile assessment and potentially constitute new treatment targets.

Potential role of tumor-associated macrophages and CD163/CD68 ratio in mycosis fungoides and Sézary syndrome in correlation with serum sCD163 and CCL22

Currently, there are no curative treatment options for mycosis fungoides (MF) and Sézary syndrome (SS) other than stem cell transplant. Understanding the interplay between tumor cells and tumor microenvironment could aid in the development of new therapies. Tumor-associated macrophages (TAMs) mostly have M2 phenotype that promotes tumor progression. This study investigated CD68+ and CD163+ TAMs as well as CD163/CD68 ratio in skin lesions from different stages of MF, large-plaque parapsoriasis, and SS. Moreover, we analyzed serum levels of sCD163 and CCL22 in correlation with TAMs count and CD163/CD68 ratio. CD68+ and CD163+ TAMs count significantly increased as the disease progressed. CD163/CD68 ratio was highest at MF tumor stage and SS indicating M2 polarization with disease progression. Significant positive correlations were detected between serum levels of sCD163 and CCL22 and CD68+ and CD163+ TAMs count and CD163/CD68 ratio. We concluded that TAMs play an important role in MF progression. High CD163/CD68 ratio in tumor stage MF and SS indicates M2 polarization of TAMs with tumor progression. CD163/CD68 ratio should be considered in assessing TAMs rather than total TAMs count. Also, sCD163 and CCL22 serum levels reflect M2 load and thus could be used as markers to assess disease progression.

Vascular inflammation in moderate-to-severe atopic dermatitis is associated with enhanced Th2 response

BACKGROUND

In atopic dermatitis (AD), some studies have shown an association with increased cardiovascular disease in certain populations. However, other investigations found modest or no association. Despite conflicting results, molecular profiling studies in both AD skin and blood have demonstrated upregulation of atherosclerosis and cardiovascular risk-related markers. However, the underlying mechanisms connecting AD to vascular inflammation/atherosclerosis are unknown. In this study, we aim to determine factors associated with vascular inflammation/atherosclerosis in AD patients.

METHODS

We used 18-FDG PET-CT to characterize vascular inflammation in AD patients and healthy subjects. In parallel, we assessed their skin and blood immune profiles to determine AD-related immune biomarkers associated with vascular inflammation. We also assessed levels of circulating microparticles, which are known to be associated with increased cardiovascular risk.

RESULTS

We found significant correlations between vascular inflammation and Th2-related products in skin and blood of AD patients as well as atherosclerosis-related markers that were modulated by dupilumab. Circulating levels of endothelial microparticles were significantly higher in severe AD patients and tended to correlate with vascular inflammation assessed by PET-CT.

CONCLUSION

Vascular inflammation in AD is associated with enhanced Th2 response and clinical severity, which may explain cardiovascular comorbidities observed in select AD populations. Larger prospective studies are needed to further evaluate vascular inflammation and cardiovascular events and mortality in AD patients. Finally, as dupilumab treatment demonstrated significant modulation of atherosclerosis-related genes in AD patients compared to placebo, these data suggest that modulation of vascular inflammation with systemic treatment should be explored in patients with AD.

Macrophage CCL22 expression promotes lymphangiogenesis in patients with tongue squamous cell carcinoma via IL-4/STAT6 in the tumor microenvironment

The C-C motif chemokine ligand 22 (CCL22) chemokine is produced by M2-like tumor-associated macrophages (TAMs) in the tumor microenvironment. Chemokine C-C motif receptor 4 (CCR4), the CCL22 receptor, on T helper2 (Th2) cells leads to a Th2 cytokine-dominant environment. In our previous study, lymph node metastasis was the main predictor of tongue squamous cell carcinoma (SCC) via CCL22. Therefore, the present study aimed to investigate the effects of CCL22 and a Th2 cytokine-predominant tumor microenvironment on vascular endothelial growth factor (VEGF)-C expression and lymphangiogenesis. The post-operative courses of 110 patients with early-stage tongue SCC with a histopathological diagnosis based on the 8th TNM classification were followed up (mean/median follow-up time, 47.1/42.0 months) from surgery until death or the last follow-up visit, and subsequent lymph node relapse was assessed. Lymphangiogenesis and the immunohistochemical expression of several markers (CCL22, CCR4 and VEGF-C) were evaluated. The Kaplan-Meier method was used to plot lymph node relapse-free survival and overall survival curves, which were compared using the log-rank test. In vitro, the association between CCL22 and VEGF-C by interleukin (IL)-4/signal transducer and activator of transcription 6 (STAT6) stimulation was examined. Lymphangiogenesis was significantly associated with lymph node relapse (P<0.001) and a CCL22⁺ macrophage ratio (P<0.001). CCL22⁺ TAMs were positive for VEGF-C and surrounded by CCR4⁺ cells. Additionally, VEGF-C expression was increased in IL-4/STAT6-stimulated macrophages. In addition, the STAT6 signaling pathway was activated in the SCC cells in the deeply invaded part of the tumor along with the aggregated macrophages. In conclusion, TAM CCL22 expression led to lymph node relapse via VEGF-C expression within the tumor microenvironment and the IL-4/STAT6 signaling pathway in early stage tongue SCC. Additionally, the worst pattern of invasion and depth of invasion were revealed to be useful parameters for lymph node relapse in patients with tongue SCC. The present study suggested that CCL22 contributed to the role of M2-like differentiated TAMs in prognosis and lymph node relapse via IL-4/STAT6 and VEGF. The IL-4/STAT6 signaling pathway may be a new molecular target for tongue SCC.

Clearance of senescent cells during cardiac ischemia-reperfusion injury improves recovery

A key component of cardiac ischemia-reperfusion injury (IRI) is the increased generation of reactive oxygen species, leading to enhanced inflammation and tissue dysfunction in patients following intervention for myocardial infarction. In this study, we hypothesized that oxidative stress, due to ischemia-reperfusion, induces senescence which contributes to the pathophysiology of cardiac IRI. We demonstrate that IRI induces cellular senescence in both cardiomyocytes and interstitial cell populations and treatment with the senolytic drug navitoclax after ischemia-reperfusion improves left ventricular function, increases myocardial vascularization, and decreases scar size. SWATH-MS-based proteomics revealed that biological processes associated with fibrosis and inflammation that were increased following ischemia-reperfusion were attenuated upon senescent cell clearance. Furthermore, navitoclax treatment reduced the expression of pro-inflammatory, profibrotic, and anti-angiogenic cytokines, including interferon gamma-induced protein-10, TGF-β3, interleukin-11, interleukin-16, and fractalkine. Our study provides proof-of-concept evidence that cellular senescence contributes to impaired heart function and adverse remodeling following cardiac ischemia-reperfusion. We also establish that post-IRI the SASP plays a considerable role in the inflammatory response. Subsequently, senolytic treatment, at a clinically feasible time-point, attenuates multiple components of this response and improves clinically important parameters. Thus, cellular senescence represents a potential novel therapeutic avenue to improve patient outcomes following cardiac ischemia-reperfusion.

Gene Expression Changes in the Skin of Patients Undergoing Medial Thigh Liposuction With Pre-Surgical and Post-Surgical Application of Topical Products

BACKGROUND

Skin topical preconditioning before and after surgical procedures is a relatively new concept, particularly in relation to the efficient removal of tissue breakdown products. Clinical trials demonstrate improvements, such as less induration, when surgery is combined with topical product preconditioning and with usage post-surgery.

OBJECTIVES

This trial aimed to assess the efficacy of such a regimen at the molecular level through gene expression studies in combination with clinical assessments.

METHODS

Six women who underwent medial thigh liposuction administered either a bland moisturizer or the experimental topical products to each side of the surgical area twice daily. Biopsies were taken before any topical application, at 2 and 4 weeks after liposuction. An inflammation-related gene expression analysis was conducted to compare the different conditions. In addition, the degree of induration was assessed in a blinded manner.

RESULTS

Compared with the bland moisturizer, the experimental group demonstrated a hastened immune inflammatory response moving more rapidly to an anti-inflammatory reversal at 2 weeks followed by a wound healing extracellular remodeling effect at 4 weeks. This matched the clinical picture depicting less induration with the treatment.

CONCLUSIONS

For patients undergoing body procedures, a topical treatment with the Alastin induces an accelerated healing response, inducing the clearance of "waste" products and the induction of anti-inflammatory genes. Furthermore, this topical treatment stimulates extracellular matrix remodeling, which ultimately leads to less induration.

LEVEL OF EVIDENCE 5

Transcriptional Activation of Matricellular Protein Spondin2 (SPON2) by BRG1 in Vascular Endothelial Cells Promotes Macrophage Chemotaxis

The matricellular protein SPON2 plays diverse roles in the development of cardiovascular diseases. SPON2 is expressed in endothelial cells, but its transcription regulation in the context of atherogenesis remains incompletely appreciated. Here we report that SPON2 expression was up-regulated by pro-atherogenic stimuli (oxLDL and TNF-α) in vascular endothelia cells. In addition, endothelial SPON2 was elevated in Apoe^–/– mice fed on a Western diet compared to the control mice. Induction of SPON2 in endothelial cells by pro-atherogenic stimuli was mediated by BRG1, a chromatin remodeling protein, both in vitro and in vivo. Further analysis revealed that BRG1 interacted with the sequence-specific transcription factor Egr-1 to activate SPON2 transcription. BRG1 contributed to SPON2 trans-activation by modulating chromatin structure surrounding the SPON2 promoter. Functionally, activation of SPON2 transcription by the Egr-1/BRG1 complex provided chemoattractive cues for macrophage trafficking. SPON2 depletion abrogated the ability of BRG1 or Egr-1 to stimulate endothelial derived chemoattractive cue for macrophage migration. On the contrary, recombinant SPON2 rescued endothelial chemo-attractability in the absence of BRG1 or Egr-1. In conclusion, our data have identified a novel transcriptional cascade in endothelial cells that may potentially promote macrophage recruitment and vascular inflammation leading to atherogenesis.

IGFBP6 Is Downregulated in Unstable Carotid Atherosclerotic Plaques According to an Integrated Bioinformatics Analysis and Experimental Verification

Aims: To investigate the differentially expressed genes (DEGs) and molecular interaction in unstable atherosclerotic carotid plaques.

Methods: Gene expression datasets GSE41571, GSE118481, and E-MTAB-2055 were analyzed. Co-regulated DEGs in at least two datasets were analyzed with the enrichment of Gene Ontology Biological Process (GO-BP), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interaction (PPI) networks, interrelationships between miRNAs/transcriptional factors, and their target genes and drug-gene interactions. The expression of notable DEGs in human carotid artery plaques and plasma was further identified.

Results: The GO-BP enrichment analysis revealed that genes associated with inflammatory response, and extracellular matrix organization were altered. The KEGG enrichment analysis revealed that upregulated DEGs were enriched in the tuberculous, lysosomal, and chemokine signaling pathways, whereas downregulated genes were enriched in the focal adhesion and PI3K/Akt signaling pathway. Collagen type I alpha 2 chain (COL1A2), adenylate cyclase 3 (ADCY3), C-X-C motif chemokine receptor 4 (CXCR4), and TYRO protein tyrosine kinase binding protein (TYROBP) might play crucial roles in the PPI networks. In drug–gene interactions, colony-stimulating factor-1 receptor had the most drug interactions. Insulin-like growth factor binding protein 6 (IGFBP6) was markedly downregulated in unstable human carotid plaques and plasma. Under a receiver operating characteristic curve analysis, plasma IGFBP6 had a significant discriminatory power (AUC, 0.894; 95% CI, 0.810–0.977), with a cutoff value of 142.08 ng/mL.

Conclusions: The genes COL1A2, ADCY3, CXCR4, and TYROBP are promising targets for the prevention of unstable carotid plaque formation. IGFBP6 may be an important biomarker for predicting vulnerable plaques.