Relationship between Circulating Inflammatory Monocytes and Cardiovascular Disease Measures of Carotid Intimal Thickness

Identification of Hub Genes and Immune Infiltration in Coronary Artery Disease: A Risk Prediction Model

Purpose

Our study aimed to establish a prediction model for coronary artery disease (CAD) that integrates immune infiltration and a gene expression signature.

Methods

613 differentially expressed genes (DEGs) and 12 hub genes were screened via the GSE113079 dataset. The pathway enrichment analysis indicated that these genes (613 DEGs and 12 hub genes) were closely associated with the inflammatory and immune responses. Based on the differentially expressed miRNA (DEmiRNA)-DEG regulatory network and immune cell infiltration, the Lasso algorithm constructed a CAD risk prediction model containing the risk score and immune score. Then, ROC-AUC and polymerase chain reaction (PCR) were performed for validation.

Results

Six hub genes (PTGER1, PIK3R1, ADRA2A, CORT, CXCL12, and S1PR5) had a high distinguishing capability (AUC > 0.90). In addition, the miRNAs targeting 12 hub genes were predicted and intersected with the DEmiRNAs, and the DEmiRNA-DEG regulatory network was then constructed. Two LASSO models and a novel CAD risk prediction model were constructed through LASSO regression analysis, and they both accurately obtained the risk of CAD. The CAD risk prediction model shows good performance (AUC = 0.988). We also constructed a valid nomogram, and PCR results verified three downregulation hub genes and one upregulation gene in the CAD risk model.

Conclusion

We demonstrated the molecular mechanism of the hub genes in CAD and provided a valuable tool for predicting the risk of CAD.

Synergy Between NK Cells and Monocytes in Potentiating Cardiovascular Disease Risk in Severe COVID-19

BACKGROUND

Evidence suggests that COVID-19 predisposes to cardiovascular diseases (CVDs). While monocytes/macrophages play a central role in the immunopathogenesis of atherosclerosis, less is known about their immunopathogenic mechanisms that lead to CVDs during COVID-19. Natural killer (NK) cells, which play an intermediary role during pathologies like atherosclerosis, are dysregulated during COVID-19. Here, we sought to investigate altered immune cells and their associations with CVD risk during severe COVID-19.

METHODS

We measured plasma biomarkers of CVDs and determined phenotypes of circulating immune subsets using spectral flow cytometry. We compared these between patients with severe COVID-19 (severe, n=31), those who recovered from severe COVID-19 (recovered, n=29), and SARS-CoV-2-uninfected controls (controls, n=17). In vivo observations were supported using in vitro assays to highlight possible mechanistic links between dysregulated immune subsets and biomarkers during and after COVID-19. We performed multidimensional analyses of published single-cell transcriptome data of monocytes and NK cells during severe COVID-19 to substantiate in vivo findings.

RESULTS

During severe COVID-19, we observed alterations in cardiometabolic biomarkers including oxidized-low-density lipoprotein, which showed decreased levels in severe and recovered groups. Severe patients exhibited dysregulated monocyte subsets, including increased frequencies of proinflammatory intermediate monocytes (also observed in the recovered) and decreased nonclassical monocytes. All identified NK-cell subsets in the severe COVID-19 group displayed increased expression of activation and tissue-resident markers, such as CD69 (cluster of differentiation 69). We observed significant correlations between altered immune subsets and plasma oxidized-low-density lipoprotein levels. In vitro assays revealed increased uptake of oxidized-low-density lipoprotein into monocyte-derived macrophages in the presence of NK cells activated by plasma of patients with severe COVID-19. Transcriptome analyses confirmed enriched proinflammatory responses and lipid dysregulation associated with epigenetic modifications in monocytes and NK cells during severe COVID-19.

CONCLUSIONS

Our study provides new insights into the involvement of monocytes and NK cells in the increased CVD risk observed during and after COVID-19.

The Effect of Statins on Carotid Intima-Media Thickness and C-Reactive Protein in Type 2 Diabetes Mellitus: A Meta-Analysis

BACKGROUND

The effect of statins on CIMT progression and C-reactive protein (CRP) in T2DM patients is widely reported. However, some studies demonstrated no effect of statins on CIMT and CRP in T2DM patients, while others reported otherwise. Thus, the current study comprehensively and quantitatively analyzes data from previous studies to evaluate the overall effect of statins on CIMT and CRP in T2DM to rule out any inconsistencies observed in previous clinical evidence. Therefore, the aim of this meta-oanalysis was to evaluate the effect of statins on CIMT progression and CRP in T2DM.

METHODS

A comprehensive search for studies was performed using PubMed, Scopus, Web of Sciences, and the Cochrane Library, for publications from their inception to 16 July 2024. The meta-analysis was conducted using Jamovi (version 4.2.8) and Review Manager (version 5.4), with the overall effect sizes reported as standardized mean differences (SMD) and 95% confidence intervals (CI).

RESULTS

Evidence from eleven studies (fifteen statin dosages) that met the inclusion criteria with a sample size of 983 T2DM patients on statin treatment was analyzed. The overall effect size from the random effect model meta-analysis showed a reduction in the CIMT status amongst T2DM patients post-statin treatment compared to at baseline [SMD = -0.47, 95%CI (-0.76, -0.18), p = 0.001]. Furthermore, there was a reduction in the level of CRP in T2DM patients post-treatment [SMD = -1.80, 95% CI (-2.76, -0.84), p < 0.001].

CONCLUSIONS

Evidence gathered in this study suggests that statin therapy effectively reduces CIMT and CRP levels among patients living with T2DM. Interestingly, this evidence suggests that 20 mg of atorvastatin is more effective in reducing CIMT and CRP. Therefore, we recommend conducting further trials with larger sample sizes and proper methodology for T2DM.

Single Cell High Dimensional Analysis of Human Peripheral Blood Mononuclear Cells Reveals Unique Intermediate Monocyte Subsets Associated with Sex Differences in Coronary Artery Disease

Monocytes are associated with human cardiovascular disease progression. Monocytes are segregated into three major subsets: classical (cMo), intermediate (iMo), and nonclassical (nMo). Recent studies have identified heterogeneity within each of these main monocyte classes, yet the extent to which these subsets contribute to heart disease progression is not known. Peripheral blood mononuclear cells (PBMC) were obtained from 61 human subjects within the Coronary Assessment of Virginia (CAVA) Cohort. Coronary atherosclerosis severity was quantified using the Gensini Score (GS). We employed high-dimensional single-cell transcriptome and protein methods to define how human monocytes differ in subjects with low to severe coronary artery disease. We analyzed 487 immune-related genes and 49 surface proteins at the single-cell level using Antibody-Seq (Ab-Seq). We identified six subsets of myeloid cells (cMo, iMo, nMo, plasmacytoid DC, classical DC, and DC3) at the single-cell level based on surface proteins, and we associated these subsets with coronary artery disease (CAD) incidence based on Gensini score (GS) in each subject. Only frequencies of iMo were associated with high CAD (GS > 32), adj.p = 0.024. Spearman correlation analysis with GS from each subject revealed a positive correlation with iMo frequencies (r = 0.314, p = 0.014) and further showed a robust sex-dependent positive correlation in female subjects (r = 0.663, p = 0.004). cMo frequencies did not correlate with CAD severity. Key gene pathways differed in iMo among low and high CAD subjects and between males and females. Further single-cell analysis of iMo revealed three iMo subsets in human PBMC, distinguished by the expression of HLA-DR, CXCR3, and CD206. We found that the frequency of immunoregulatory iMo_HLA-DR+CXCR3+CD206+ was associated with CAD severity (adj.p = 0.006). The immunoregulatory iMo subset positively correlated with GS in both females (r = 0.660, p = 0.004) and males (r = 0.315, p = 0.037). Cell interaction analyses identified strong interactions of iMo with CD4+ effector/memory T cells and Tregs from the same subjects. This study shows the importance of iMo in CAD progression and suggests that iMo may have important functional roles in modulating CAD risk, particularly among females.

Comprehensive proteomics of monocytes indicates oxidative imbalance functionally related to inflammatory response in chronic kidney disease-related atherosclerosis

Atherosclerosis-induced cardiovascular events are the leading cause of mortality in chronic kidney disease (CKD) patients. Monocytes are involved in the formation of atherosclerotic plaques and mediate in the overproduction of ROS, promoting inflammation and oxidative stress. However, the relationship between monocytes, inflammation, and oxidative status in CKD-associated atherosclerosis has not been thoroughly investigated. Monocytes and plasma derived from two groups of CKD patients with varying degrees of atherosclerosis and two groups of patients with cardiovascular disease (CVD) and non-CKD atherosclerosis were analyzed. This study was designed to perform a comprehensive proteomic analysis of monocytes in combination with functional bioinformatics. In addition, a targeted investigation of oxidative stress- and inflammatory-related factors to explore CKD-associated atherosclerosis was applied. Dysregulation of proteins involved in lipid oxidation, cell survival, ROS synthesis and metabolism, and inflammatory responses has been revealed. The characteristic disturbances in the monocyte proteome changed with the progression of CKD. A closer examination of oxidative stress's triggers, mediators, and effects on protein and lipid levels showed alterations in the oxidative imbalance between CKD and CVD. CKD monocytes demonstrated a significant increase of oxidized glutathione without changing the level of its reduced form. Evaluation of enzymatic antioxidants, sources of ROS, and modifications caused by ROS also revealed significant alterations between the study groups. In CKD, inflammation and oxidative imbalance correlated and drove each other. However, in CVD, oxidative stress-related factors were associated with each other but not to inflammatory proteins. Moreover, lipid abnormalities were more specific to classical CVD and unrelated to CKD. Such a comprehensive characterization of monocytes and oxidative stress in CKD and CVD patients has never been presented so far. Obtained results support the involvement of distinct mechanisms underlying the acceleration of atherosclerotic and non-atherosclerotic CKD.

Macrophage profiling in atherosclerosis: understanding the unstable plaque

The development and rupture of atherosclerotic plaques is a major contributor to myocardial infarctions and ischemic strokes. The dynamic evolution of the plaque is largely attributed to monocyte/macrophage functions, which respond to various stimuli in the plaque microenvironment. To this end, macrophages play a central role in atherosclerotic lesions through the uptake of oxidized low-density lipoprotein that gets trapped in the artery wall, and the induction of an inflammatory response that can differentially affect the stability of the plaque in men and women. In this environment, macrophages can polarize towards pro-inflammatory M1 or anti-inflammatory M2 phenotypes, which represent the extremes of the polarization spectrum that include Mhem, M(Hb), Mox, and M4 populations. However, this traditional macrophage model paradigm has been redefined to include numerous immune and nonimmune cell clusters based on in-depth unbiased single-cell approaches. The goal of this review is to highlight (1) the phenotypic and functional properties of monocyte subsets in the circulation, and macrophage populations in atherosclerotic plaques, as well as their contribution towards stable or unstable phenotypes in men and women, and (2) single-cell RNA sequencing studies that have advanced our knowledge of immune, particularly macrophage signatures present in the atherosclerotic niche. We discuss the importance of performing high-dimensional approaches to facilitate the development of novel sex-specific immunotherapies that aim to reduce the risk of cardiovascular events.

Neutrophil/HDL-C, Lymphocyte/HDL-C and Monocyte/HDL-C in subjects with asymptomatic carotid atherosclerosis

BACKGROUND

Leukocyte count is a prognostic marker for cardiovascular diseases, with key role in atherosclerosis development. Specific number of neutrophils, lymphocytes and monocytes can predict cardiovascular risk, also in asymptomatic subjects. Among the lipoprotein fractions, HDL-C is a protective factor in the cardiovascular disorders. For the above reason, we have examined the peripheral count of leukocytes, neutrophils, lymphocytes and monocytes, and the ratios between neutrophils/HDL-cholesterol, lymphocytes/HDL-cholesterol, and monocytes/HDL-cholesterol, to evaluate the possible utility of the obtained values in progression of asymptomatic carotid atherosclerosis.

METHODS

We performed our analysis in a cohort of 100 subjects with asymptomatic carotid atherosclerosis, of which 43 men and 57 women. The data were expressed as medians and IQR. To analyse the differences in leukocyte, neutrophil, lymphocyte, monocytes count and their ratio with HDL-cholesterol the Mann-Whitney test was employed.

RESULTS

The peripheral count of leukocyte subtypes and the ratios, they change in relation to the number of cardiovascular risk factors and the degree of insulin resistance.

CONCLUSIONS

In this cohort of subjects, the percentage of observed cardiovascular risk factors significantly affect some leukocyte parameters. These results, allow us to underline the importance of the leukocyte indices in the evaluation of subjects with asymptomatic vascular atherosclerosis.

Remnant cholesterol has an important impact on increased carotid intima-media thickness in non-diabetic individuals

To investigate the correlation the correlation between residual cholesterol (RC) and increased carotid intima-media thickness(cIMT) in non-diabetic individuals. This study included 1786 non-diabetic individuals who underwent carotid ultrasound. RC was calculated based on total cholesterol (TC), LDL-C, and high density lipoprotein cholesterol (HDL-C). The subjects were divided into the cIMT thickening group (cIMT ≥ 0.1 cm) and non-thickening group (cIMT < 0.1 cm) groups based on cIMT, binary logistic regression with different models and receiver operating characteristic (ROC) curves were adopted to evaluate the predictive ability of RC in cIMT. Of the research participants , their median age was 55 (49-51) years, 1121 (63%) were male, and 209 (12%) had hypertension, and people in the cIMT thickening group (925) were more likely to be older and male than those in the non-thickening group (843). Across the different RC subgroups, there was an increasing trend in maximum cIMT (P < 0.001) as RC levels increased within quartiles. RC was found to be an independent risk predictor for cIMT thickening (all P <  in models 1-3); and this result persisted in the LDL-C normal subgroup (P = 0.002). The results suggested that RC was an independent predictor of cIMT thickening in non-diabetic individuals and had a strong atherogenic effect.

Intermediate Monocytes and Circulating Endothelial Cells: Interplay with Severity of Atherosclerosis in Patients with Coronary Artery Disease and Type 2 Diabetes Mellitus

The aim was to investigate the association of monocyte heterogeneity and presence of circulating endothelial cells with the severity of coronary atherosclerosis in patients with coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM). We recruited 62 patients with CAD, including 22 patients with DM2. The severity of atherosclerosis was evaluated using Gensini Score. Numbers of classical (CD14++CD16-), intermediate (CD14++CD16+), and non-classical (CD14+CD16++) monocyte subsets; circulating endothelial progenitor cells; and the presence of circulating endothelial cells were evaluated. Counts and frequencies of intermediate monocytes, but not glycaemia parameters, were associated with the severity of atherosclerosis in diabetic CAD patients (rs = 0.689; p = 0.001 and rs = 0.632; p = 0.002, respectively). Frequency of Tie2+ cells was lower in classical than in non-classical monocytes in CAD patients (p = 0.007), while in patients with association of CAD and T2DM, differences between Tie2+ monocytes subsets disappeared (p = 0.080). Circulating endothelial cells were determined in 100% of CAD+T2DM patients, and counts of CD14++CD16+ monocytes and concentration of TGF-β predicted the presence of circulating endothelial cells (sensitivity 92.3%; specificity 90.9%; AUC = 0.930). Thus, intermediate monocytes represent one of the key determinants of the appearance of circulating endothelial cells in all the patients with CAD, but are associated with the severity of atherosclerosis only in patients with association of CAD and T2DM.

Plasma galectin-3 is associated with decreased glomerular filtration rate in chronic HIV

BACKGROUND

People living with HIV (PLWH) have higher rates of chronic kidney disease (CKD) compared with HIV-uninfected individuals. The pathogenesis of CKD in HIV remains poorly understood but is likely from a combination of various factors, such as traditional comorbidities, prolonged antiretroviral therapy, immune dysregulation, and direct HIV effect on the kidneys. We evaluated plasma galectin-3 (Gal-3), a circulating marker of fibrosis, and its association with renal function.

METHODS

Estimated glomerular filtration rate (eGFR) was assessed by CKD-EPI. Plasma galectin-3 was obtained from banked specimens by ELISA. Factors associated with eGFR were analyzed using step-wise multiple linear regression.

RESULTS

A total of 45 PLWH and 58 HIV-uninfected participants were included with similar demographic parameters. Among PLWH, majority had undetectable plasma HIV RNA (82.2%). Gal-3 was significantly higher in PLWH than in HIV-uninfected participants (6.4 [IQR 4.0, 8.5] ng/mL and 4.5 [IQR 2.3, 6.5] ng/mL, respectively; p = 0.020) while a trend towards lower eGFR was found in PLWH compared to the HIV-uninfected cohort (86.8 [IQR 71.3, 91.8] and 89.0 [IQR 78.6, 97.4] mL/min/1.73 m2, respectively; p = 0.071). In univariable analysis, HIV status was marginally associated with decreased eGFR (β coefficient= -0.035, p = 0.051). In the final multivariable regression model adjusted for traditional risk factors of CKD, Gal-3 independently predicted a decrease in eGFR (unstandardized B= -0.008, p < 0.001) while HIV status did not demonstrate any significant association.

CONCLUSION

Gal-3 was higher in PLWH compared with HIV-uninfected participants. In multivariable adjusted analyses, Gal-3, but not HIV status, was associated with decreased eGFR. The role of Gal-3 as a biomarker of kidney function needs to be further elucidated.

Association between carotid intima-media thickness and acute kidney injury following isolated coronary artery bypass surgery

OBJECTIVE

The association between pre-operative carotid intima-media thickness (CIMT) and early postoperative acute kidney injury (AKI) following isolated coronary artery bypass grafting (CABG) was investigated.

METHODS

Data were sought retrospectively of 237 patients (166 male, 71 female; mean age 61.4 ± 8.1 years; range: 32-74), operated on for isolated CABG with cardiopulmonary bypass (CPB) in a single centre between June 2014 and December 2020, with a serum creatinine level < 1.5 mg/dl and normal carotid arteries on Doppler ultrasonography. AKI diagnosis was made according to the Kidney Disease Improving Global Outcomes 2012 Acute Kidney Injury Guideline. Patients were grouped as group 1 with AKI in the early postoperative period (n = 63) and group 2 without AKI ( n = 174). Univariate analyses were done to determine significant clinical factors, and subsequent multiple logistic regression analysis was done to determine independent predictors of AKI.

RESULTS

AKI occurred in 63 (26.6%) patients. Pre-operative CIMT was significantly higher in the AKI group (p = 0.0001). Multivariate logistic regression analysis revealed that elevated pre-operative CIMT ( p = 0.005), C-reactive protein ( p = 0.001), erythrocyte sedimentation rate ( p = 0.005), neutrophil-lymphocyte ratio ( p = 0.0001) and platelet-lymphocyte ratio ( p = 0.0001) increased on the postoperative seventh day. C-reactive protein ( p = 0.04), postoperative first day platelet- lymphocyte ratio ( p = 0.0001), postoperative seventh day erythrocyte sedimentation rate ( p = 0.02) and intubation time ( p = 0.02) were independent predictors of early postoperative AKI following isolated CABG.

CONCLUSIONS

Pre-operative CIMT was found to be an independent predictor of AKI in the early postoperative period of isolated CABG.

Increased transmigration of intermediate monocytes associated with atherosclerotic burden in people with HIV on antiretroviral therapy

This study evaluated the association between the transmigration of monocyte subpopulations that contributes to atherosclerosis development, along with surrogate biomarkers of inflammation and atherosclerosis, through carotid intima-media thickness (cIMT) measurements of 72 people with HIV (PWH) on suppressive antiretroviral therapy (ART). We found that the transmigration of intermediate monocytes was positively correlated with D-dimer and cIMT, suggesting that intermediate monocytes may have a greater propensity to promote cardiovascular disease (CVD) in PWH on ART.

Elevated circulating monocytes and monocyte activation in COVID-19 convalescent individuals

Background

Monocytes and macrophages play a pivotal role in inflammation during acute SARS-CoV-2 infection. However, their contribution to the development of post-acute sequelae of SARS-CoV-2 infection (PASC) are not fully elucidated.

Methods

A cross-sectional study was conducted comparing plasma cytokine and monocyte levels among three groups: participants with pulmonary PASC (PPASC) with a reduced predicted diffusing capacity for carbon monoxide [DLCOc, <80%; (PG)]; fully recovered from SARS-CoV-2 with no residual symptoms (recovered group, RG); and negative for SARS-CoV-2 (negative group, NG). The expressions of cytokines were measured in plasma of study cohort by Luminex assay. The percentages and numbers of monocyte subsets (classical, intermediate, and non-classical monocytes) and monocyte activation (defined by CD169 expression) were analyzed using flow cytometry analysis of peripheral blood mononuclear cells.

Results

Plasma IL-1Ra levels were elevated but FGF levels were reduced in PG compared to NG. Circulating monocytes and three subsets were significantly higher in PG and RG compared to NG. PG and RG exhibited higher levels of CD169+ monocyte counts and higher CD169 expression was detected in intermediate and non-classical monocytes from RG and PG than that found in NG. Further correlation analysis with CD169+ monocyte subsets revealed that CD169+ intermediate monocytes negatively correlated with DLCOc%, and CD169+ non-classical monocytes positively correlated with IL-1α, IL-1β, MIP-1α, Eotaxin, and IFN-γ.

Conclusion

This study present evidence that COVID convalescents exhibit monocyte alteration beyond the acute COVID-19 infection period even in convalescents with no residual symptoms. Further, the results suggest that monocyte alteration and increased activated monocyte subsets may impact pulmonary function in COVID-19 convalescents. This observation will aid in understanding the immunopathologic feature of pulmonary PASC development, resolution, and subsequent therapeutic interventions.

Prevalence and risk factors of sarcopenia without obesity and sarcopenic obesity among Chinese community older people in suburban area of Shanghai: A cross-sectional study

Objectives

The aim of the present study was to explore the prevalence and risk factors of sarcopenia without obesity (S) and sarcopenic obesity (SO) among community-dwelling older people in the Chongming District of Shanghai, China, according to the Asian Working Group for Sarcopenia (AWGS) 2019 Consensus as the diagnostic criteria of sarcopenia.

Methods

In this cross-sectional study, a total of 1,407 subjects aged ≥65 years were included, where the mean age of the subjects was 71.91 ± 5.59 years and their mean body mass index (BMI) was 24.65 ± 3.32 kg/m². According to the Asian Working Group for Sarcopenia (AWGS) 2019 Consensus, sarcopenia was defined as a low appendicular skeletal muscle mass index (≤7.0 kg/m² in males and ≤5.7 kg/m² in females), decreased handgrip strength (<28.0 kg in males and <18.0 kg in females), and/or low gait speed (<1.0 m/s) or poor 5-time chair stand test (5CST) (≥12s). The SO met both the diagnostic criteria for sarcopenia and obesity, meanwhile obesity was defined as an increased percentage of body fat (PBF) (≥25% in males and ≥35% in females). Univariate and multiple logistic regression analyses were performed to explore the risk factors of both S and SO.

Results

The prevalence of S and SO was 9.74% (M: 9.29%, F: 10.05%) and 9.95% (M: 13.94%, F: 7.14%). Lower BMI (OR = 0.136, 95% CI: 0.054-0.340, p < 0.001), lower hip circumference (OR = 0.858, 95% CI: 0.816-0.903, p < 0.001), farming (OR = 1.632, 95% CI: 1.053-2.530, p = 0.028), higher high-density lipoprotein cholesterol (HDL-C) level (OR = 2.235, 95% CI: 1.484-3.367, p < 0.001), and a sleep duration <7 h (OR = 0.561, 95% CI: 0.346-0.909, p = 0.019) were risk factors for S. While aging (70-74 y, OR = 1.923, 95% CI: 1.122-3.295, p = 0.017; 75-79 y, OR = 3.185, 95% CI: 1.816-5.585, p < 0.001; ≥80 y, OR = 7.192, 95% CI: 4.133-12.513, p < 0.001), male (OR = 1.981, 95% CI: 1.351-2.904, p < 0.001), higher BMI (OR = 4.865, 95% CI: 1.089-21.736, p = 0.038), higher monocyte level (OR = 4.203, 95% CI: 1.340-13.181, p = 0.014), and a sleep duration >9 h (OR = 1.881, 95% CI: 1.117-3.166, p = 0.017) were risk factors for SO.

Conclusion

Our study showed the high prevalence of S and SO among community-dwelling older people in the Chongming District. The SO was more prevalent in males. Behavioral factors and lifestyle (such as farming and sleep duration) were associated more with the development of S, while age and male gender were associated more with the development of SO.

Associations of Baseline and Changes in Leukocyte Counts with Incident Cardiovascular Events: The Dongfeng-Tongji Cohort Study

AIM

The aim of the present study was to investigate the associations of baseline and longitudinal changes in leukocyte counts with incident cardiovascular disease (CVD).

METHODS

We conducted a prospective study to investigate the associations of baseline and 5-year changes in leukocyte counts with incident CVD and its subtypes in middle-aged and elderly Chinese. We estimated the hazard ratios (HRs) and 95% confidence intervals (CIs) for CVD using the Cox proportional-hazards models.

RESULTS

In the analyses of baseline total leukocyte count of 26,655 participants, compared with the lowest quartile (＜4.71×109/L), participants in the fourth quartile (＞6.70×109/L) had 11% higher risk for CVD. Consistent with total leukocyte count, neutrophil count also exhibited a significant positive association with the risk of CVD. In the analyses of 5-year changes in total leukocyte count of 11,594 participants, the changes in leukocyte count were categorized into three groups, i.e., the decreased group (＜25%), stable group (25%-75%), and increased group (＞75%). Compared with participants in the stable group (-1.18 to 0.44×109/L), participants in the increased group (＞0.44×109/L) had 14% higher risk for CVD. We also observed significant positive associations of the changes in neutrophil and monocyte counts with the risk of CVD. Furthermore, the total leukocyte count in the second or third tertile at the first follow-up with a 5-year increase was related to higher CVD risk.

CONCLUSION

High baseline total leukocyte count and a 5-year increase in total leukocyte count were related to higher CVD risk.

Plasma CD16+ Extracellular Vesicles Associate with Carotid Artery Intima-Media Thickness in HIV+ Adults on Combination Antiretroviral Therapy

HIV-infected individuals have increased risk for cardiovascular disease (CVD) despite suppressive antiretroviral therapy (ART). This is likely a result of persistent immune activation and systemic inflammation. Extracellular vesicles (EVs) have emerged as critical mediators of intercellular communication and may drive inflammation contributing to CVD. EVs were characterized in plasma from 74 HIV-infected individuals on combination antiretroviral therapy (cART) and 64 HIV-uninfected controls with paired carotid intima-media thickness (cIMT) assessment. EVs were profiled with markers reflecting lymphoid, myeloid, and endothelial origin. Seventeen plasma inflammatory biomarkers were also assessed. Human umbilical vein endothelial cell (HUVEC) apoptosis was quantified after EV exposure. A significant correlation was observed in HIV-infected participants between cIMT and EVs expressing CD16, and the monocyte-related markers CD4, CD14, and CX3CR1 showed a similar but nonsignificant association with cIMT. No significant correlation between cIMT measurements from HIV-uninfected individuals and EVs was observed. Levels of serum amyloid A, C-reactive protein, and myeloperoxidase significantly correlated with CD14⁺, CD16⁺, and CX3CR1⁺ EVs. No correlation was noted between cIMT and soluble inflammatory markers. HUVECs showed increased necrosis after exposure to the EV-containing fraction of plasma derived from HIV-infected individuals compared to uninfected controls. Our study reveals that EVs expressing monocyte markers correlated with cIMT in HIV-infected individuals on cART. Moreover, EV fractions derived from HIV-infected individuals lead to greater endothelial cell death via necrotic pathways. Collectively, EVs have potential as biomarkers of and therapeutic targets in the pathogenesis of CVD in the setting of treated HIV disease. IMPORTANCE HIV-infected individuals have a 2-fold-increased risk of cardiovascular disease compared with the general population, yet the mechanisms underlying this comorbidity are unclear. Extracellular vesicles have emerged as important mediators in cell-cell communication and, given what we know of their biology, may drive inflammation contributing to cardiovascular disease in this vulnerable population.

Placental dysfunction influences fetal monocyte subpopulation gene expression in preterm birth

The placenta is the primary organ for immune regulation, nutrient delivery, gas exchange, protection against environmental toxins, and physiologic perturbations during pregnancy. Placental inflammation and vascular dysfunction during pregnancy are associated with a growing list of prematurity-related complications. The goal of this study was to identify differences in gene expression profiles in fetal monocytes - cells that persist and differentiate postnatally - according to distinct placental histologic domains. Here, by using bulk RNA-Seq, we report that placental lesions are associated with gene expression changes in fetal monocyte subsets. Specifically, we found that fetal monocytes exposed to acute placental inflammation upregulate biological processes related to monocyte activation, monocyte chemotaxis, and platelet function, while monocytes exposed to maternal vascular malperfusion lesions downregulate these processes. Additionally, we show that intermediate monocytes might be a source of mitogens, such as HBEGF, NRG1, and VEGFA, implicated in different outcomes related to prematurity. This is the first study to our knowledge to show that placental lesions are associated with unique changes in fetal monocytes and monocyte subsets. As fetal monocytes persist and differentiate into various phagocytic cells following birth, our study may provide insight into morbidity related to prematurity and ultimately potential therapeutic targets.

Increased frequency of proangiogenic tunica intima endothelial kinase 2 (Tie2) expressing monocytes in individuals with type 2 diabetes mellitus

Background

Individuals with type 2 diabetes mellitus (T2DM) have an increased risk for developing macrovascular disease (MVD) manifested by atherosclerosis. Phenotypically and functionally different monocyte subsets (classical; CD14⁺⁺CD16⁻, non-classical; CD14⁺CD16⁺⁺, and intermediate; CD14⁺⁺CD16⁺) including pro-angiogenic monocytes expressing Tie2 (TEMs) can be identified. Here we investigated monocyte heterogeneity and its association with T2DM and MVD.

Methods

Individuals with (N = 51) and without (N = 56) T2DM were recruited and allocated to "non-MVD" or "with MVD" (i.e., peripheral or coronary artery disease) subgroups. Blood monocyte subsets were quantified based on CD14, CD16 and Tie2 expression levels. Plasma levels of Tie2-ligands angiopoietin-1 and angiopoietin-2 were determined using ELISA. Carotid endarterectomy samples from individuals with (N = 24) and without (N = 22) T2DM were stained for intraplaque CD68⁺ macrophages (inflammation) and CD34⁺ (angiogenesis), as plaque vulnerability markers.

Results

Monocyte counts were similar between individuals with T2DM and healthy controls (non-diabetic, non-MVD). Non-classical monocytes were reduced (p < 0.05) in T2DM, whereas the percentage of TEMs within the intermediate subset was increased (p < 0.05). T2DM was associated with increased angiopoietin-1 (p < 0.05) and angiopoietin-2 (p = 0.0001) levels. Angiopoietin-2 levels were higher in T2DM individuals with MVD compared with non-MVD (p < 0.01). Endarterectomized plaques showed no differences in macrophage influx and microvessel number between individuals with and without T2DM.

Conclusions

Monocyte subset distribution is altered in T2DM with reduced non-classical monocytes and increased TEM percentage in the intermediate monocyte subset. Increased angiopoietin-2 levels together with increased frequency of TEMs might promote plaque vulnerability in T2DM which could however not be confirmed at tissue level in advanced atherosclerotic lesions.

Increased biomarkers of cardiovascular risk in HIV-1 viremic controllers and low persistent inflammation in elite controllers and art-suppressed individuals

HIV controllers (HICs) are models of HIV functional cure, although some studies have shown persistent inflammation and increased rates of atherosclerosis in HICs. Since immune activation/inflammation contributes to the pathogenesis of cardiovascular diseases (CVD), we evaluated clinical data and inflammation markers in HIV-1 viremic controllers (VC), elite controllers (EC), and control groups (HIV positive individuals with virological suppression by antiretroviral therapy-cART; HIV negative individuals-HIVneg) to assess whether they presented elevated levels of inflammation markers also associated with CVD. We observed the highest frequencies of activated CD8+ T cells in VCs, while EC and cART groups presented similar but slightly altered frequencies of this marker when compared to the HIVneg group. Regarding platelet activation, both HICs groups presented higher expression of P-selectin in platelets when compared to control groups. Monocyte subset analyses revealed lower frequencies of classical monocytes and increased frequencies of non-classical and intermediate monocytes among cART individuals and in EC when compared to HIV negative individuals, but none of the differences were significant. For VC, however, significant decreases in frequencies of classical monocytes and increases in the frequency of intermediate monocytes were observed in comparison to HIV negative individuals. The frequency of monocytes expressing tissue factor was similar among the groups on all subsets. In terms of plasma markers, VC had higher levels of many inflammatory markers, while EC had higher levels of VCAM-1 and ICAM-1 compared to control groups. Our data showed that VCs display increased levels of inflammation markers that have been associated with CVD risk. Meanwhile, ECs show signals of lower but persistent inflammation, comparable to the cART group, indicating the potential benefits of alternative therapies to decrease inflammation in this group.

Apolipoprotein A1 deficiency in mice primes bone marrow stem cells for T cell lymphopoiesis

The bone marrow has emerged as a potentially important target in cardiovascular disease as it generates all leukocytes involved in atherogenesis. In the current study, we evaluated whether a change in bone marrow functionality underlies the increased atherosclerosis susceptibility associated with high-density lipoprotein (HDL) deficiency. We found that HDL deficiency in mice due to the genetic lack of hepatocyte-derived apolipoprotein A1 (APOA1) was associated with an increase in the Lin⁻Sca-1⁺Kit⁺ (LSK) bone marrow stem cell population and lymphoid-primed multipotent progenitor numbers, which translated into a higher production and systemic flux of T cell subsets. In accordance with APOA1 deficiency-associated priming of stem cells to increase T lymphocyte production, atherogenic diet-fed low-density lipoprotein receptor knockout mice transplanted with bone marrow from APOA1-knockout mice displayed marked lymphocytosis as compared to wild-type bone marrow recipients. However, atherosclerotic lesion sizes and collagen contents were similar in the two groups of bone marrow recipients. In conclusion, systemic lack of APOA1 primes bone marrow stem cells for T cell lymphopoiesis. Our data provide novel evidence for a regulatory role of HDL in bone marrow functioning in normolipidemic mice.

Summary: Changes in cholesterol metabolism, that is, in high-density lipoprotein levels, can significantly impact leukocyte numbers via modulating bone marrow functionality.

The Predictive Value of Carotid Ultrasonography With Cardiovascular Risk Factors-A "SPIDER" Promoting Atherosclerosis

Insufficient recommendations do not support the clinical use of carotid ultrasonography for further risk stratification in moderate-to-high risk patients with cardiovascular disease (CVD). A literature review was performed to assess six aspects of the research progress and limitations of carotid ultrasonography and carotid atherosclerosis-related risk factors: (1) structures of the carotid intima and media; (2) plaques; (3) inflammation; (4) dynamics of carotid blood flow; (5) early detection and intervention; and (6) risk factors for CVD. Although carotid intima-media thickness and carotid plaques are well-acknowledged independent predictors of CVD risk, normative and cut-off values are difficult to define due to the heterogeneous measurements reported in previous studies. Plaque properties, including location, number, density, and size, become more important risk predictors for cardiovascular disease, but a better approach for clinical use needs to be further established. Three-dimensional ultrasound and contrast-enhanced ultrasound are promising for promoting risk stratification with more details on plaque morphology. Moreover, inflammatory diseases and biomarkers should be evaluated for a full assessment of the inflammatory burden for atherosclerosis. Carotid flow velocity is not only an indicator for stenosis but also a potential risk predictor. Carotid atherosclerosis should be detected and treated early, and additional clinical trials are needed to determine the efficacy of these measures in reducing CVD risk. Cardiovascular risk factors tend to affect carotid plaques, and early treat-to-target therapy might yield clinical benefits. Based on the aforementioned six aspects, we consider that these six important factors act like a “SPIDER” spinning the web of atherosclerosis; a timely comprehensive assessment and intervention may halt the progression to CVD. Carotid ultrasound results should be combined with other atherosclerotic factors, and a comprehensive risk assessment may help to guide cardiovascular prevention decisions.

Assessment of medullary and extramedullary myelopoiesis in cardiovascular diseases

Recruitment of innate immune cells and their accumulation in the arterial wall and infarcted myocardium has been recognized as a central feature of atherosclerosis and cardiac ischemic injury, respectively. In both, steady state and under pathological conditions, majority of these cells have a finite life span and are continuously replenished from haematopoietic stem/progenitor cell pool residing in the bone marrow and extramedullary sites. While having a crucial role in the cardiovascular disease development, proliferation and differentiation of innate immune cells within haematopoietic compartments is greatly affected by the ongoing cardiovascular pathology. In the current review, we summarize key cells, processes and tissue compartments that are involved in myelopoiesis under the steady state, during atherosclerosis development and in myocardial infarction.

Leukocyte Count and Risks of Stroke and Coronary Heart Disease: The Circulatory Risk in Communities Study (CIRCS)

Aim: This study aimed to investigate the associations of leukocyte count with the risks of stroke and coronary heart disease among the general Japanese population.

Methods: A total of 5,242 residents aged 40–69 years living in two Japanese communities underwent leukocyte count measurements between 1991 and 2000, and the data were updated using 5- or 10-year follow-ups or both. Participants who had histories of stroke, coronary heart disease, or high values of leukocyte count (＞130×10 ² cells/mm ³ ) were excluded. Hazard ratios with 95% confidence intervals (CIs) were calculated according to quartiles of cumulative average leukocyte count.

Results: During follow-up of 21 years, 327 stroke and 130 coronary heart disease cases were determined. After adjustments for age, sex, community, and updated cardiovascular risk factors, the multivariable hazard ratio (95% CI) for the highest versus lowest quartile of leukocyte count was 1.50 (1.08–2.08) for ischemic stroke, 1.59 (1.00–2.51) for lacunar infarction, 1.42 (0.90–2.26) for non-lacunar infarction, 2.17 (1.33–3.55) for coronary heart disease, and 1.40 (1.11–1.76) for total cardiovascular disease. In smoking status-stratified analyses, the corresponding multivariable hazard ratio (95% CI) was 2.45 (1.11–5.38) for ischemic stroke, 2.73 (1.37–5.44) for coronary heart disease in current smokers, 2.42 (1.07–5.46), 1.55 (0.58–4.15) in former smokers, and 1.17 (0.75–1.82), 1.78 (0.83–3.82) in never smokers.

Conclusion: Leukocyte count was positively associated with the risks of ischemic stroke and coronary heart disease among the general Japanese population, especially in current smokers.

In vitro Phenotype Induction of Circulating Monocytes: CD16 and CD163 Analysis

Introduction

CD14 (monocyte differentiation antigen, LPS binding protein – endotoxin receptor) and CD16 (FcγRIII, Low-affinity receptor for IgG) define three subpopulations of circulating monocytes with different inflammatory and phagocytic capabilities. Contradictory reports exist regarding both in vivo monocyte phenotype-disease association and response of these circulating monocytes to in vitro stimulation. We analyzed phenotypic changes in circulating monocytes when stimulated with LPS (pro-inflammatory stimulus) and IL-4 (alternative inflammatory stimulus).

Methods

Mononuclear cells from nine healthy donors were extracted and studied for surface and intracellular markers using flow cytometry. PBMC were extracted using Ficoll technic and immediately analyzed using flow cytometry. Pro-inflammatory interleukin IL-1β and IL-6 were measured by intracellular cytometry. Mononuclear cells were stimulated using LPS and IL-4 as previously described. Changes against non-stimulated populations were statistically analyzed.

Results

Compared to non-stimulated and IL-4 stimulated monocytes, LPS-stimulated cells display a singular pattern of markers, with higher levels of intracellular IL-1β and IL-6 directly correlating with CD14+CD163- cell frequency and diminishing membrane CD163 fluorescence. CD14+CD16- classical monocytes show greater percentage of CD163- cells upon LPS stimulation. CD86 levels on monocytes’ surface did not change with LPS or IL-4 stimulation.

Conclusions and Discussion

We showed that CD14+CD16- classical monocytes display higher sensitivity to LPS stimulation, with more IL-1β and IL-6 levels than intermediate and non-classical monocytes. This subset also diminishes its CD163 levels on the membrane after LPS stimulation with a contemporary raise in CD163- cells, suggesting that classical monocytes preferentially acquire CD163- defined M1 characteristics upon in vitro LPS stimulation. Intermediate and non-classical monocytes respond with lower levels of interleukins and display surface proteins in an M2-type profile (CD163+).