Circulating Monocyte Chemoattractant Protein-1 and Risk of Stroke: Meta-Analysis of Population-Based Studies Involving 17 180 Individuals

Causal effect of circulating cytokines on MRI markers of cerebral small vessel disease: A mendelian randomization study

BACKGROUND

Previous observational studies have reported the correlation between circulating inflammatory cytokines and cerebral small vessel disease (CSVD). However, the causality of this association is uncertain. This study used Mendelian randomization to investigate the causal effect of circulating inflammatory cytokines on neuroimaging changes in CSVD.

METHODS

This study utilized genetic variances of 41 inflammatory cytokines and 3 neuroimaging markers of CSVD from genome-wide association studies to assess the causal effects in a two-sample Mendelian randomization approach. Inverse variance weighted analysis was used as the main analytical method, and sensitivity analysis was used to further validate the robustness of the results.

RESULTS

Increased IL-18 was associated with increased white matter hyperintensity (WMH) and mean diffusivity (MD) (β = 0.034, 95 % CI 0.002, 0.065, P=0.038, β = 0.157, 95 % CI 0.015, 0.299, P=0.030). However, increased IL-18 was associated with decreased fractional anisotropy (FA) (β = -0.141, 95 % CI -0.279, -0.002, P=0.047). Increased monocyte chemotactic protein-1(MCP-1) was associated with decreased FA (β = -0.278, 95 % CI -0.502, -0.054, P=0.015). Increased IL-10 levels and IL-2ra levels were associated with decreased risks of MD (β = -0.228, 95 % CI -0.448, -0.009, p = 0.041; β = -0.204, 95 % CI=-0.377, -0.031, p = 0.021).

CONCLUSIONS

This study revealed that increased levels of IL-18 and MCP-1 were associated with white matter microstructural injury, and increased levels of IL-10 and IL-2ra were associated with decreased MD.

Monocyte Chemoattractant Protein-1, Inflammatory Biomarkers, and Prognosis of Patients With Ischemic Stroke or Transient Ischemic Attack: Fndings From a Nationwide Registry Study

BACKGROUND

Recent Mendelian randomization and meta-analysis highlight the relevance of MCP-1 (monocyte chemoattractant protein-1) in stroke. We aimed to investigate the associations between MCP-1 and clinical outcomes in patients with ischemic stroke or transient ischemic attack and test whether inflammation mediates or jointly contributes to the relationships.

METHODS AND RESULTS

A total of 10 700 patients from the Third China National Stroke Registry study were included. Multivariable Cox regression was used for recurrent stroke and all-cause death, and logistic regression was used for poor functional outcome. Mediation analyses were performed to clarify whether inflammation mediates the associations. After adjusting for potential confounders, low MCP-1 level (<337.6 pg/mL) was associated with a reduced risk of all-cause death (hazard ratio [HR], 0.65 [95% CI, 0.51-0.82]) and poor functional outcome (odds ratio, 0.81 [95% CI, 0.70-0.94]) but was not associated with recurrent stroke (HR, 1.10 [95% CI, 0.95-1.27]), compared with high MCP-1 level (≥337.6 pg/mL). The association between MCP-1 and all-cause death was partially mediated by highly sensitive C-reactive protein, interleukin-6, and YKL-40 (Chitinase-3-like protein 1; mediated proportion: 7.4%, 10.5%, and 7.4%, respectively). The corresponding mediated proportion for poor functional outcome was 9.9%, 17.1%, and 7.1%, respectively. Patients with combined high levels of MCP-1 and inflammatory biomarkers had the highest risks of all-cause death and poor functional outcome.

CONCLUSIONS

Low plasma MCP-1 level was associated with decreased risks of all-cause mortality and poor functional outcome after ischemic stroke or transient ischemic attack. Inflammation partially mediated and jointly contributed to the associations.

Elucidating the role of chemokines in inflammaging associated atherosclerotic cardiovascular diseases

Age-related inflammation or inflammaging is a critical deciding factor of physiological homeostasis during aging. Cardiovascular diseases (CVDs) are exquisitely associated with aging and inflammation and are one of the leading causes of high mortality in the elderly population. Inflammaging comprises dysregulation of crosstalk between the vascular and cardiac tissues that deteriorates the vasculature network leading to development of atherosclerosis and atherosclerotic-associated CVDs in elderly populations. Leukocyte differentiation, migration and recruitment holds a crucial position in both inflammaging and atherosclerotic CVDs through relaying the activity of an intricate network of inflammation-associated protein-protein interactions. Among these interactions, small immunoproteins such as chemokines play a major role in the progression of inflammaging and atherosclerosis. Chemokines are actively involved in lymphocyte migration and severe inflammatory response at the site of injury. They relay their functions via chemokine-G protein-coupled receptors-glycosaminoglycan signaling axis and is a principal part for the detection of age-related atherosclerosis and related CVDs. This review focuses on highlighting the detailed intricacies of the effects of chemokine-receptor interaction and chemokine oligomerization on lymphocyte recruitment and its evident role in clinical manifestations of atherosclerosis and related CVDs. Further, the role of chemokine mediated signaling for formulating next-generation therapeutics against atherosclerosis has also been discussed.

Monocyte chemoattractant protein-1 detection in wound tissue fluids for the assisted diagnosis of wound infection

BACKGROUND

Infections are commonly seen in wounds. The overall infection rate is 1.8% to 4.2%. Improper infection management can lead to serious conditions and may progress to life-threatening sepsis. Because there is a need for assistance in predicting wound infection before obvious clinical symptoms, the measurement of cytokines in wound tissue fluids has attracted our attention for determining the overall status of wound infection. Our intent was to assess the potential biomarkers in the diagnosis of wound infection.

METHODS

We collected 146 tissue fluids (acute: 59, chronic: 61, and normal: 26) for analysis of biomarkers using a human cytokine array. Serum C-reactive protein was also measured from 104 patients. The sensitivity and specificity of significant wound cytokines and serum C-reactive protein for the diagnosis of wound infection were evaluated.

RESULTS

Among biomarkers examined, serum C-reactive protein and tissue C-reactive protein were highly expressed in acute infection wounds, whereas monocyte chemoattractant protein-1 was significantly expressed in chronic infection wounds. Because the expression of wound biomarkers varied in different types of wounds, relationships among them were studied. A high correlation between tissue C-reactive protein and interleukin-8 (R2 = 0.7) and a moderate correlation between systemic and local C-reactive protein (R2 = 0.47) were observed. In addition, tissue monocyte chemoattractant protein-1 had better sensitivity (74%) and specificity (65%) in the diagnosis of wound infection. Moreover, combined serum C-reactive protein with monocyte chemoattractant protein-1 examination provided a higher area under the curve in the receiver operator characteristic curve (0.75).

CONCLUSION

We found that tissue monocyte chemoattractant protein-1 is a superior diagnostic marker for assistance with the diagnosis of wound infection.

Rare damaging CCR2 variants are associated with lower lifetime cardiovascular risk

Background

Previous work has shown a role of CCL2, a key chemokine governing monocyte trafficking, in atherosclerosis. However, it remains unknown whether targeting CCR2, the cognate receptor of CCL2, provides protection against human atherosclerotic cardiovascular disease.

Methods

Computationally predicted damaging or loss-of-function (REVEL>0.5) variants within CCR2 were detected in whole-exome-sequencing data from 454,775 UK Biobank participants and tested for association with cardiovascular endpoints in gene-burden tests. Given the key role of CCR2 in monocyte mobilization, variants associated with lower monocyte count were prioritized for experimental validation. The response to CCL2 of human cells transfected with these variants was tested in migration and cAMP assays. Validated damaging variants were tested for association with cardiovascular endpoints, atherosclerosis burden, and vascular risk factors. Significant associations were replicated in six independent datasets (n=1,062,595).

Results

Carriers of 45 predicted damaging or loss-of-function CCR2 variants (n=787 individuals) were at lower risk of myocardial infarction and coronary artery disease. One of these variants (M249K, n=585, 0.15% of European ancestry individuals) was associated with lower monocyte count and with both decreased downstream signaling and chemoattraction in response to CCL2. While M249K showed no association with conventional vascular risk factors, it was consistently associated with a lower risk of myocardial infarction (Odds Ratio [OR]: 0.66 95% Confidence Interval [CI]: 0.54-0.81, p=6.1×10-5) and coronary artery disease (OR: 0.74 95%CI: 0.63-0.87, p=2.9×10-4) in the UK Biobank and in six replication cohorts. In a phenome-wide association study, there was no evidence of a higher risk of infections among M249K carriers.

Conclusions

Carriers of an experimentally confirmed damaging CCR2 variant are at a lower lifetime risk of myocardial infarction and coronary artery disease without carrying a higher risk of infections. Our findings provide genetic support for the translational potential of CCR2-targeting as an atheroprotective approach.

Significance of neutrophil extracellular traps-related gene in the diagnosis and classification of atherosclerosis

Atherosclerosis (AS) is a pathological process associated with various cardiovascular diseases. Upon different stimuli, neutrophils release reticular complexes known as neutrophil extracellular traps (NETs). Numerous researches have indicated a strong correlation between NETs and AS. However, its role in cardiovascular disease requires further investigation. By utilizing a machine learning algorithm, we examined the genes associated with NETs that were expressed differently in individuals with AS compared to normal controls. As a result, we identified four distinct genes. A nomogram model was built to forecast the incidence of AS. Additionally, we conducted analysis on immune infiltration, functional enrichment and consensus clustering in AS samples. The findings indicated that individuals with AS could be categorized into two groups, exhibiting notable variations in immune infiltration traits among the groups. Furthermore, to measure the NETs model, the principal component analysis algorithm was developed and cluster B outperformed cluster A in terms of NETs. Additionally, there were variations in the expression of multiple chemokines between the two subtypes. By studying AS NETs, we acquired fresh knowledge about the molecular patterns and immune mechanisms implicated, which could open up new possibilities for AS immunotherapy.

Evaluation of the causal effects of immune cells on ischemic stroke: a Mendelian randomization study

Background

Ischemic stroke (IS) is a cerebrovascular disease caused by various factors, and its etiology remains inadequately understood. The role of immune system dysfunction in IS has been increasingly recognized. Our objective was to evaluate whether circulating immune cells causally impact IS risk.

Methods

We conducted two-sample Mendelian randomization analyses to evaluate the causal effects of 731 immune cell traits on IS, utilizing publicly available genome-wide association studies (GWAS) summary statistics for 731 immune cell traits as exposure data, and two GWAS statistics for IS as outcome data. A set of sensitivity analyses, including Cochran's Q test, I 2 statistics, MR-Egger intercept test, MR-PRESSO global test, and leave-one-out sensitivity analyses, were performed to assess the robustness of the results. Additionally, meta-analyses were conducted to combine the results from the two different IS datasets. Finally, we extracted instrumental variables of immune cell traits with causal effects on IS in both IS datasets for SNP annotation.

Results

A total of 41 and 35 immune cell traits were identified to have significant causal effects on IS based on two different IS datasets, respectively. Among them, the immune cell trait CD62L- plasmacytoid Dendritic Cell AC and CD4+ CD8dim T cell%leukocyte respectively served as risk factor and protective element in both IS datasets. The robustness of the causal effects was confirmed through the sensitivity analyses. The results of the meta-analyses further support the causal effects of CD62L- plasmacytoid Dendritic Cell AC (pooled OR=1.030, 95%CI: 1.011-1.049, P=0.002) and CD4+ CD8dim T cell%leukocyte (pooled OR=0.959, 95%CI: 0.935-0.984, P=0.001). Based on these two immune cell traits, 33 genes that may be related to the causal effects were mapped.

Conclusions

Our study demonstrated the potential causal effects of circulating immune cells on IS, providing valuable insights for future studies aimed at preventing IS.

The role of digestive system diseases in cerebrovascular disease: a comprehensive Mendelian randomization study

Background

Cerebrovascular disease, among the most prevalent neurological disorders, poses a substantial threat to human health with its elevated mortality and disability rates, placing considerable strain on healthcare systems. Although several studies in recent years have suggested a potential association between digestive system diseases and cerebrovascular diseases, the findings remain inconsistent.

Methods

Genome-wide association study (GWAS) summary data for 12 digestive diseases and cerebrovascular diseases were used to conduct Mendelian randomization (MR) analysis. In this investigation, we endeavored to elucidate the causal relationship between digestive system diseases and cerebrovascular diseases. Employing a comprehensive approach, including two-sample MR (TSMR), multivariate MR (MVMR), and two-step MR analysis, we leveraged summary statistics data obtained from published GWAS. The primary analysis method employed was inverse variance weighted (IVW), with MR-Egger and weighted median (WM) as secondary methods. Sensitivity analysis included heterogeneity testing, horizontal multivariate testing, MR-PRESSO, and a "leave-one-out" method. Additionally, the F-statistic was utilized to assess the strength of instrumental variables, ensuring robust results.

Results

In the TSMR analysis, this study found a significant causal relationship between genetically predicted gastroesophageal reflux disease (GERD) and any stroke (AS), any ischemic stroke (AIS), large-artery atherosclerotic stroke (LAS), intracranial aneurysm (IA), and subarachnoid hemorrhage (SAH). In MVMR analysis, this study found that even after adjusting for systolic blood pressure (SBP), body mass index (BMI) and type 2 diabetes (T2D), the causal relationship remains exist. In the two-step MR mediation analysis, it was found that BMI, SBP and T2D play mediating role in the causal relationship between GERD and cerebrovascular diseases.

Conclusion

This study indicates a clear positive causal relationship between GERD and cerebrovascular diseases, and this causal association remains significant even after adjusting for BMI, SBP and T2D. The mediation MR analysis suggests that BMI, SBP and T2D may mediate the causal relationship between GERD and the risk of cerebrovascular diseases.

Causal role of immune cell traits in stroke: A Mendelian randomization study

OBJECTIVES

Immune mechanisms play a crucial role in the development of stroke. However, immune-related phenotypes are diverse and their associations with stroke are largely unknown. Here, we aimed to systematically explore the causal role of immune cell traits in stroke and its subtypes by leveraging data from genome-wide association studies (GWASs).

MATERIALS AND METHODS

Exposure data were obtained from a recent GWAS on 731 immune cell traits profiled by flow cytometry involving 3757 individuals. By conducting two-sample univariable Mendelian randomization (MR) analyses, each immune cell trait was assessed for causal relationships with stroke outcomes from the MEGASTROKE Consortium (40,585 cases and 406,111 controls). The robustness of the MR results was verified by a series of sensitivity analyses.

RESULTS

We identified three significant associations after Bonferroni correction (P < 1.37E-05). Increased CD27 expression on memory B cell (OR = 1.23, 95% CI = 1.14-1.33, P = 2.78E-08), IgD-CD38dim B cell (OR = 1.16, 95% CI = 1.09-1.23, P = 5.98E-06) and unswitched memory B cell (OR = 1.18, 95% CI = 1.10-1.27, P = 1.09E-05) were associated with a higher risk of large-artery atherosclerotic stroke (LAS). Furthermore, expression quantitative trait loci data also indicated elevated blood CD27 mRNA level was a risk factor for LAS (OR = 1.37, 95% CI = 1.02-1.84, P = 0.037).

CONCLUSIONS

This study provided genetic evidence of the causal relationship between immune cell traits and stroke, highlighting the role of CD27 on memory B cell as a novel factor for LAS risk.

Targeting inflammation to reduce recurrent stroke

BACKGROUND

Approximately one in four stroke patients suffer from recurrent vascular events, underlying the necessity to improve secondary stroke prevention strategies. Immune mechanisms are causally associated with coronary atherosclerosis. However, stroke is a heterogeneous disease and the relative contribution of inflammation across stroke mechanisms is not well understood. The optimal design of future randomized control trials (RCTs) of anti-inflammatory therapies to prevent recurrence after stroke must be informed by a clear understanding of the prognostic role of inflammation according to stroke subtype and individual patient factors.

AIM

In this narrative review, we discuss (1) inflammatory pathways in the etiology of ischemic stroke subtypes; (2) the evidence on inflammatory markers and vascular recurrence after stroke; and (3) review RCT evidence of anti-inflammatory agents for vascular prevention.

SUMMARY OF REVIEW

Experimental work, genetic epidemiological data, and plaque-imaging studies all implicate inflammation in atherosclerotic stroke. However, emerging evidence also suggests that inflammatory mechanisms are also important in other stroke mechanisms. Advanced neuroimaging techniques support the role of neuroinflammation in blood-brain barrier dysfunction in cerebral small vessel disease (cSVD). Systemic inflammatory processes also promote atrial cardiopathy, incident and recurrent atrial fibrillation (AF). Although several inflammatory markers have been associated with recurrence after stroke, interleukin-6 (IL-6) and high-sensitivity C-reactive protein (hsCRP) are presently the most promising markers to identify patients at increased vascular risk. Several RCTs have shown that anti-inflammatory therapies reduce vascular risk, including stroke, in coronary artery disease (CAD). Some, but not all of these trials, selected patients on the basis of elevated hsCRP. Although unproven after stroke, targeting inflammation to reduce recurrence is a compelling strategy and several RCTs are ongoing.

CONCLUSION

Evidence points toward the importance of inflammation across multiple stroke etiologies and potential benefit of anti-inflammatory targets in secondary stroke prevention. Taking the heterogeneous stroke etiologies into account, the use of serum biomarkers could be useful to identify patients with residual inflammatory risk and perform biomarker-led patient selection for future RCTs.

A synthesis of pathways linking diet, metabolic risk and cardiovascular disease: a framework to guide further research and approaches to evidence-based practice

Cardiovascular disease (CVD) is the most common non-communicable disease occurring globally. Although previous literature has provided useful insights into the important role that diet plays in CVD prevention and treatment, understanding the causal role of diets is a difficult task considering inherent and introduced weaknesses of observational (e.g. not properly addressing confounders and mediators) and experimental research designs (e.g. not appropriate or well designed). In this narrative review, we organised current evidence linking diet, as well as conventional and emerging physiological risk factors, with CVD risk, incidence and mortality in a series of diagrams. The diagrams presented can aid causal inference studies as they provide a visual representation of the types of studies underlying the associations between potential risk markers/factors for CVD. This may facilitate the selection of variables to be considered and the creation of analytical models. Evidence depicted in the diagrams was systematically collected from studies included in the British Nutrition Task Force report on diet and CVD and database searches, including Medline and Embase. Although several markers and disorders linked to conventional and emerging risk factors for CVD were identified, the causal link between many remains unknown. There is a need to address the multifactorial nature of CVD and the complex interplay between conventional and emerging risk factors with natural and built environments, while bringing the life course into the spotlight.

Mendelian randomization suggests a causal relationship between gut dysbiosis and thyroid cancer

Background

Alterations in gut microbiota composition and function have been linked to the development and progression of thyroid cancer (TC). However, the exact nature of the causal relationship between them remains uncertain.

Methods

A bidirectional two-sample Mendelian randomization (TSMR) analysis was conducted to assess the causal connection between gut microbiota (18,340 individuals) and TC (6,699 cases combined with 1,613,655 controls) using data from a genome-wide association study (GWAS). The primary analysis used the inverse-variance weighted (IVW) method to estimate the causal effect, with supplementary approaches including the weighted median, weighted mode, simple mode, and MR-Egger. Heterogeneity and pleiotropy were assessed using the Cochrane Q test, MR-Egger intercept test, and MR-PRESSO global test. A reverse TSMR analysis was performed to explore reverse causality.

Results

This study identified seven microbial taxa with significant associations with TC. Specifically, the genus Butyrivibrio (OR: 1.127, 95% CI: 1.008-1.260, p = 0.036), Fusicatenibacter (OR: 1.313, 95% CI: 1.066-1.618, p = 0.011), Oscillospira (OR: 1.240, 95% CI: 1.001-1.536, p = 0.049), Ruminococcus2 (OR: 1.408, 95% CI: 1.158-1.711, p < 0.001), Terrisporobacter (OR: 1.241, 95% CI: 1.018-1.513, p = 0.032) were identified as risk factors for TC, while The genus Olsenella (OR: 0.882, 95% CI: 0.787-0.989, p = 0.031) and Ruminococcaceae UCG004 (OR: 0.719, 95% CI: 0.566-0.914, p = 0.007) were associated with reduced TC risk. The reverse MR analysis found no evidence of reverse causality and suggested that TC may lead to increased levels of the genus Holdemanella (β: 0.053, 95% CI: 0.012~0.094, p = 0.011) and decreased levels of the order Bacillales (β: -0.075, 95% CI: -0.143~-0.006, p = 0.033). No significant bias, heterogeneity, or pleiotropy was detected in this study.

Conclusion

This study suggests a potential causal relationship between gut microbiota and TC, providing new insights into the role of gut microbiota in TC. Further research is needed to explore the underlying biological mechanisms.

Adipokines and Bacterial Metabolites: A Pivotal Molecular Bridge Linking Obesity and Gut Microbiota Dysbiosis to Target

Adipokines are essential mediators produced by adipose tissue and exert multiple biological functions. In particular, adiponectin, leptin, resistin, IL-6, MCP-1 and PAI-1 play specific roles in the crosstalk between adipose tissue and other organs involved in metabolic, immune and vascular health. During obesity, adipokine imbalance occurs and leads to a low-grade pro-inflammatory status, promoting insulin resistance-related diabetes and its vascular complications. A causal link between obesity and gut microbiota dysbiosis has been demonstrated. The deregulation of gut bacteria communities characterizing this dysbiosis influences the synthesis of bacterial substances including lipopolysaccharides and specific metabolites, generated via the degradation of dietary components, such as short-chain fatty acids, trimethylamine metabolized into trimethylamine-oxide in the liver and indole derivatives. Emerging evidence suggests that these bacterial metabolites modulate signaling pathways involved in adipokine production and action. This review summarizes the current knowledge about the molecular links between gut bacteria-derived metabolites and adipokine imbalance in obesity, and emphasizes their roles in key pathological mechanisms related to oxidative stress, inflammation, insulin resistance and vascular disorder. Given this interaction between adipokines and bacterial metabolites, the review highlights their relevance (i) as complementary clinical biomarkers to better explore the metabolic, inflammatory and vascular complications during obesity and gut microbiota dysbiosis, and (ii) as targets for new antioxidant, anti-inflammatory and prebiotic triple action strategies.

Mural cell-derived chemokines provide a protective niche to safeguard vascular macrophages and limit chronic inflammation

Maladaptive, non-resolving inflammation contributes to chronic inflammatory diseases such as atherosclerosis. Because macrophages remove necrotic cells, defective macrophage programs can promote chronic inflammation with persistent tissue injury. Here, we investigated the mechanisms sustaining vascular macrophages. Intravital imaging revealed a spatiotemporal macrophage niche across vascular beds alongside mural cells (MCs)-pericytes and smooth muscle cells. Single-cell transcriptomics, co-culture, and genetic deletion experiments revealed MC-derived expression of the chemokines CCL2 and MIF, which actively preserved macrophage survival and their homeostatic functions. In atherosclerosis, this positioned macrophages in viable plaque areas, away from the necrotic core, and maintained a homeostatic macrophage phenotype. Disruption of this MC-macrophage unit via MC-specific deletion of these chemokines triggered detrimental macrophage relocalizing, exacerbated plaque necrosis, inflammation, and atheroprogression. In line, CCL2 inhibition at advanced stages of atherosclerosis showed detrimental effects. This work presents a MC-driven safeguard toward maintaining the homeostatic vascular macrophage niche.

Short-term effects of allulose consumption on glucose homeostasis, metabolic parameters, incretin levels, and inflammatory markers in patients with type 2 diabetes: a double-blind, randomized, controlled crossover clinical trial

PURPOSE

Allulose is a rare monosaccharide with almost zero calories. There is no study of short-term allulose consumption in patients with type 2 diabetes (T2D). Thus, we aimed to study the effect of allulose consumption for 12 weeks on glucose homeostasis, lipid profile, body composition, incretin levels, and inflammatory markers in patients with T2D.

METHODS

A double-blind, randomized, controlled crossover study was conducted on sixteen patients with T2D. Patients were randomly assigned to allulose 7 g twice daily or aspartame 0.03 g twice daily for 12 weeks. After a 2-week washout, patients were crossed over to the other sweetener for an additional 12 weeks. Oral glucose tolerance tests, laboratory measurements, and dual-energy X-ray absorptiometry were conducted before and after each phase.

RESULTS

This study revealed that short-term allulose consumption exerted no significant effect on glucose homeostasis, incretin levels, or body composition but significantly increased MCP-1 levels (259 ± 101 pg/ml at baseline vs. 297 ± 108 pg/mL after 12 weeks of allulose, p = 0.002). High-density lipoprotein cholesterol (HDL-C) significantly decreased from 51 ± 13 mg/dl at baseline to 41 ± 12 mg/dL after 12 weeks of allulose, p < 0.001.

CONCLUSION

Twelve weeks of allulose consumption had a neutral effect on glucose homeostasis, body composition, and incretin levels. Additionally, it decreased HDL-C levels and increased MCP-1 levels.

TRIAL REGISTRATION

This trial was retrospectively registered on the Thai Clinical Trials Registry (TCTR20220516006) on December 5, 2022.

Inflammatory-associated proteomic predictors of cognitive outcome in subjects with ELVO treated by mechanical thrombectomy

BACKGROUND

Emergent Large Vessel Occlusion (ELVO) stroke causes devastating vascular events which can lead to significant cognitive decline and dementia. In the subset of ELVO subjects treated with mechanical thrombectomy (MT) at our institution, we aimed to identify systemic and intracranial proteins predictive of cognitive function at time of discharge and at 90-days. These proteomic biomarkers may serve as prognostic indicators of recovery, as well as potential targets for novel/existing therapeutics to be delivered during the subacute stage of stroke recovery.

METHODS

At the University of Kentucky Center for Advanced Translational Stroke Sciences, the BACTRAC tissue registry (clinicaltrials.gov; NCT03153683) of human biospecimens acquired during ELVO stroke by MT is utilized for research. Clinical data are collected on each enrolled subject who meets inclusion criteria. Blood samples obtained during thrombectomy were sent to Olink Proteomics for proteomic expression values. Montreal Cognitive Assessments (MoCA) were evaluated with categorical variables using ANOVA and t-tests, and continuous variables using Pearson correlations.

RESULTS

There were n = 52 subjects with discharge MoCA scores and n = 28 subjects with 90-day MoCA scores. Several systemic and intracranial proteins were identified as having significant correlations to discharge MoCA scores as well as 90-day MoCA scores. Highlighted proteins included s-DPP4, CCL11, IGFBP3, DNER, NRP1, MCP1, and COMP.

CONCLUSION

We set out to identify proteomic predictors and potential therapeutic targets related to cognitive outcomes in ELVO subjects undergoing MT. Here, we identify several proteins which predicted MoCA after MT, which may serve as therapeutic targets to lessen post-stroke cognitive decline.

Circulating levels of cytokines and risk of cardiovascular disease: a Mendelian randomization study

Background

Epidemiological studies have linked various circulating cytokines to cardiovascular disease (CVD), which however remains uncertain whether these relationships represent causality or are due to bias. To address this question, we conducted a Mendelian randomization (MR) analysis to systematically investigate the causal effects of circulating cytokine levels on CVD development.

Methods

This study leveraged the summary statistic from respective genome-wide association study (GWAS) of 47 cytokines and four types of CVD. The cis-quantitative trait locus (cis-QTL) definition, derived from a GWAS meta-analysis comprising 31,112 participants of European descent, served as instruments for cytokines. A two-sample MR design was employed, followed by comprehensive sensitivity analyses to validate the robustness of results.

Results

The results of inverse-variance weighted method using cis-protein QTL (cis-pQTL) instruments, showed the causal effects of four cytokines (i.e., IL-1ra, MCSF, SeSelectin, SCF) on the risk of coronary artery disease (CAD). We also identified causal relationships between two cytokines (i.e., IL-2ra, IP-10) and heart failure (HF), as well as two cytokines (i.e., MCP-3, SeSelectin) and atrial fibrillation (AF), after controlling for false discovery rate (FDR). The use of cis-expression QTL (cis-eQTL) revealed additional causal associations between IL-1a, MIF and CAD, between IL-6, MIF, and HF, as well as between FGFBasic and AF. No significant sign was survived for stroke with FDR applied. Results were largely consistent across sensitivity analyses.

Conclusion

The present study provides supportive evidence that genetic predisposition to levels of certain cytokines causally affects the development of specific type of CVD. These findings have important implications for the creation of novel therapeutic strategies targeting these cytokines as a means of preventing and treating CVD.

Causal associations of circulating Helicobacter pylori antibodies with stroke and the mediating role of inflammation

BACKGROUND

Observational studies have shown that Helicobacter pylori (H. pylori) infection and H. pylori antibodies are associated with an increased risk of stroke. However, which and how H. pylori antibodies serve as the causal determinant of the development of stroke remains largely unknown.

METHODS

Genome-wide association studies (GWAS) on seven different antibodies of H. pylori-specific proteins, stroke, and stroke subtypes were included in this study. Mendelian randomization (MR) and multivariable MR (MVMR) analysis were performed to assess the causal associations between H. pylori antibodies and the development of stroke and to determine the potential mechanisms underlying the associations.

RESULTS

Genetically predicted serum H. pylori vacuolating cytotoxin-A (VacA) antibody level was associated with an increased risk of all-cause stroke (odds ratio [OR] = 1.04, 95% CI 1.01-1.07, P = 0.017) and cardioembolic stroke (CES, OR = 1.11, 95% CI 1.04-1.18, P = 0.001). The results of multivariable MR (MVMR) showed that C-reactive protein (CRP), but not monocyte chemoattractant protein-1 and peptic ulcer, mediated the causal effects of VacA-positive H. pylori infection on all-cause stroke and CES. No strong causal associations were found between other H. pylori antibodies and stroke and its subtypes.

CONCLUSIONS

Our results demonstrate that H. pylori VacA antibody is the only causal determinant associated with the risk of stroke in the spectrum of H. pylori-related antibodies, in which CRP may mediate the association. This study suggests that inhibition of the CRP signaling pathway may reduce the risk of stroke in patients with VacA-positive H. pylori infection.

Effect of Tai Chi Yunshou training on the balance and motor functions of stroke patients: a systematic review and meta-analysis of randomized controlled trials

Background

There is insufficient evidence on the effect of Tai Chi Yunshou on improving balance and motor function in stroke survivors. Therefore, this systematic review and meta-analysis aimed to evaluate the effect of Tai Chi Yunshou on improving balance and motor function in stroke patients through a comprehensive literature search.

Methods

English and Chinese databases were searched from inception to February 10, 2023, to collect randomized controlled trials (RCTs) investigating the effects of Tai Chi Yunshou on balance and motor function in stroke survivors. Two reviewers independently selected studies meeting eligibility criteria, extracted required data, and assessed the risk of bias using methods recommended by the Cochrane Reviewers' Handbook. Primary outcomes were balance function and motor function, while secondary outcomes included walking gait and activities of daily living. Review Manager software (version 5.4.1) was used for data analysis.

Results

Among the 1,400 identified records, 12 eligible randomized controlled trials were finally included, with a total of 966 subjects. The results of the meta-analysis showed that the balance function of the experimental group and the control group was assessed using the Berg Balance Scale (MD = 4.87, p < 0.001, I² = 90, 95% CI = 4.46-5.28). The motor function assessment of the experimental group and the control group used the Fugl-Meyer Motor Assessment (SMD = 1.11, p < 0.001, I² = 94, 95% CI = 0.94-1.28) and Simple Test of Extremity Function (MD = 10.28, p < 0.001, I² = 0, 95% CI = 7.89-12.68). Walking ability was measured using the Time-Up and Go Test (MD = -3.22, p < 0.001, I² = 83, 95% CI = -3.71--2.73). Activities of daily living were measured using the Modified Bathel Index (MD = 4.61, p < 0.001, I² = 81, 95% CI = 3.61-5.61).

Conclusion

Initial evidence seems to show that Tai Chi Yunshou training can improve the balance and motor function of stroke survivors and further improve walking ability and daily living ability, and the rehabilitation effect may be better than that of conventional rehabilitation training.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=376969, identifier [CRD42022376969].

Circulating adipokine concentrations and the risk of venous thromboembolism: A Mendelian randomization and mediation analysis

Background: Previous observational studies have suggested that circulating adipokine concentrations are related to a greater risk of venous thromboembolism (VTE). However, it remained unclear whether these observations reflect causality.

Objective: This study aimed to investigate the causal relationship between circulating adipokine concentrations (including adiponectin, leptin, PAI-1, MCP-1, leptin receptor, and RETN) and the risk of VTE and its subtypes (DVT and PE) and to determine whether circulating adipokine concentrations are a mediator of venous thromboembolic events in obese patients.

Methods: We used Mendelian randomization (MR) analyses to determine the effects of the body mass index (BMI), adiponectin, leptin, PAI-1, MCP-1, leptin receptor, and RETN levels on VTE, DVT, and PE in a cohort of 11,288 VTE cases, 5,632 DVT cases, 5,130 PE cases, and 254,771 controls. We then assessed the proportion of the effect of obesity on VTE, DVT, and PE explained by circulating leptin levels.

Result: Genetically predicted higher BMI was related to increased VTE (OR = 1.45, p &lt; 0.001), DVT (OR = 1.63, p &lt; 0.001), and PE (OR = 1.37, p &lt; 0.001) risk, and higher circulating leptin levels increase odds of VTE (OR = 1.96, q &lt; 0.001), DVT (OR = 2.52, q &lt; 0.001), and PE (OR = 2.26, q = 0.005). In addition, we found that the causal effect between elevated serum adiponectin and the decreased risk of VTE (OR = 0.85, p = 0.013, q = 0.053) and PE (OR = 0.81, p = 0.032, q = 0.083) and between MCP-1 and the reduced risk of VTE (OR = 0.88, p = 0.048, q = 0.143) is no longer significant after FDR adjustment. In MR mediation analysis, the mediation effect of circulating leptin levels in the causal pathway from BMI to PE was estimated to be 1.28 (0.95–1.71, p = 0.10), accounting for 39.14% of the total effect.

Conclusion: The circulating leptin level is a risk factor for VTE, DVT, and PE, but it might be a potential mediator of BMI on the risk of PE, and thus, interventions on the circulating leptin level in obesity might reduce the risk of PE. Adiponectin is a potential protective factor for both VTE and PE.

Genetically downregulated Interleukin-6 signalling is associated with a lower risk of frailty

BACKGROUND

numerous studies point towards a critical role of Interleukin 6 (IL-6) pathway in frailty pathogenesis yet the causal relationship between the two remains elusive.

METHODS

we selected genetic variants near the IL-6 receptor locus (IL-6R) associated with reduced C-reactive protein (CRP) levels, a downstream effector of IL-6 pathway, and we used them as genetic proxies of IL-6 signalling downregulation. We then performed a two-sample Mendelian randomisation (MR) to investigate the association with frailty status, as defined by the Frailty Index (FI) in 11,171 individuals from the Hellenic Longitudinal Investigation of Ageing and Diet (HELIAD) study. MR analysis was repeated after excluding depression or cognition-related FI items as well as following age or sex stratification. Association with frailty was also examined using an alternative instrument, weighted on s-IL-6R levels. Replication was attempted in UK Biobank dataset.

RESULTS

genetic predisposition to IL-6 signalling downregulation, weighted on CRP levels, was associated with lower risk of frailty, inserted either as categorical (odds ratio [95% confidence interval] = 0.15 [-3.39, -0.40], P = 0.013) or continuous variable (beta [se] = -0.09 [0.003], P = 0.0009). Sensitivity analyses revealed similar estimates across different MR methods with no evidence for horizontal pleiotropy or heterogeneity. Results remained robust after exclusion of depression or cognition-related FI items and following sex or age stratification. Genetically increased s-IL-6R levels were negatively correlated with frailty and this finding remained significant in a meta-analysis of UK Biobank and HELIAD cohorts.

CONCLUSION

our results support a potential causal effect of IL-6 signalling on frailty and further suggest that downregulation of IL-6 levels may reduce frailty risk.

Inflammageing and Cardiovascular System: Focus on Cardiokines and Cardiac-Specific Biomarkers

The term "inflammageing" was introduced in 2000, with the aim of describing the chronic inflammatory state typical of elderly individuals, which is characterized by a combination of elevated levels of inflammatory biomarkers, a high burden of comorbidities, an elevated risk of disability, frailty, and premature death. Inflammageing is a hallmark of various cardiovascular diseases, including atherosclerosis, hypertension, and rapid progression to heart failure. The great experimental and clinical evidence accumulated in recent years has clearly demonstrated that early detection and counteraction of inflammageing is a promising strategy not only to prevent cardiovascular disease, but also to slow down the progressive decline of health that occurs with ageing. It is conceivable that beneficial effects of counteracting inflammageing should be most effective if implemented in the early stages, when the compensatory capacity of the organism is not completely exhausted. Early interventions and treatments require early diagnosis using reliable and cost-effective biomarkers. Indeed, recent clinical studies have demonstrated that cardiac-specific biomarkers (i.e., cardiac natriuretic peptides and cardiac troponins) are able to identify, even in the general population, the individuals at highest risk of progression to heart failure. However, further clinical studies are needed to better understand the usefulness and cost/benefit ratio of cardiac-specific biomarkers as potential targets in preventive and therapeutic strategies for early detection and counteraction of inflammageing mechanisms and in this way slowing the progressive decline of health that occurs with ageing.

Assessing the variability and the role of inflammatory cytokines and monocyte chemoattractant protein-1 (MCP-1) in predicting stroke among hypertensives: A case-control study

Background

Atherosclerosis is a complex lipid-driven inflammatory disease in which numerous cell types and inflammatory mediators are involved in the progression of hypertension to stroke. Mediators' markers that could predict the progression of hypertension to stroke are of research importance. We assessed the predictive value of individual and combined cytokines and monocyte chemoattractant protein-1 (MCP-1) among hypertensives with or without stroke.

Methods

In a case-control study, we enrolled 63 cases with stroke and hypertension (HPT-S), 59 stroke-free hypertensives (HPT), and 53 stroke free normotensives as controls (CS). Sociodemographic data and blood samples were collected for the estimation of Interleukin-10 (IL-10), IL-6, IL-8, IL-1β and monocyte chemoattractant protein-1 (MCP-1) using commercially available ELISA kits from Biobase Biotech, Shanghai, China. The Receiver Operator Characteristics (ROC) analysis was used to calculate diagnostic accuracy for cytokines in predicting stroke among hypertensives. A combined bioscore model of IL-10 and MCP-1 was generated to predict stroke among hypertensives. The multiple logistic regression analysis was used to assess the chances of IL-10 and MCP-1 in predicting stroke among hypertensives. Statistical analyses were performed using R-language.

Results

The HPT-S group had significantly higher levels of MCP-1 and IL-10 compared to the HPT and CS groups (p < 0.05). There was no significant difference in IL-1β, IL-8 and IL-6 amongst the three study groups. MCP-1 and IL-10 were predictive of stroke occurrence among hypertensives and were used to develop a bioscore model. An elevated MCP-1 and IL-10 with a bioscore 2 had a predictive accuracy of 0.81, a sensitivity of 0.77 and specificity of 0.84. At a bioscore of 1, the sensitivity and specificity for predicting stroke among hypertensives was 97.0% and 61.0% respectively. In a binary logistic regression, having a bioscore of 1 [aOR = 20.43, 95% CI (2.17-192.62), p = 0.008] or 2 [aOR = 26.00, 95% CI (2.92-231.31), p = 0.003] were significantly associated with stroke occurrence among hypertensives.

Conclusion

Higher levels of IL-10 with a concomitant level of MCP-1 could serve as a good predictor of stroke among hypertensives. Subsequently, MCP-1 may prove useful as a therapeutic target for atherosclerosis in hypertensives. Combined bioscore of MCP-1 and IL-10 could serve as a good predictor of stroke among hypertensives.

Disentangling the effects of traits with shared clustered genetic predictors using multivariable Mendelian randomization

When genetic variants in a gene cluster are associated with a disease outcome, the causal pathway from the variants to the outcome can be difficult to disentangle. For example, the chemokine receptor gene cluster contains genetic variants associated with various cytokines. Associations between variants in this cluster and stroke risk may be driven by any of these cytokines. Multivariable Mendelian randomization is an extension of standard univariable Mendelian randomization to estimate the direct effects of related exposures with shared genetic predictors. However, when genetic variants are clustered, due to being located in a single genetic region, a Goldilocks dilemma arises: including too many highly-correlated variants in the analysis can lead to ill-conditioning, but pruning variants too aggressively can lead to imprecise estimates or even lack of identification. We propose multivariable methods that use principal component analysis to reduce many correlated genetic variants into a smaller number of orthogonal components that are used as instrumental variables. We show in simulations that these methods result in more precise estimates that are less sensitive to numerical instability due to both strong correlations and small changes in the input data. We apply the methods to demonstrate the most likely causal risk factor for stroke at the chemokine gene cluster is monocyte chemoattractant protein-1.

Estrogen Receptor Subtypes Elicit a Distinct Gene Expression Profile of Endothelial-Derived Factors Implicated in Atherosclerotic Plaque Vulnerability

In the presence of established atherosclerosis, estrogens are potentially harmful. MMP-2 and MMP-9, their inhibitors (TIMP-2 and TIMP-1), RANK, RANKL, OPG, MCP-1, lysyl oxidase (LOX), PDGF-β, and ADAMTS-4 play critical roles in plaque instability/rupture. We aimed to investigate (i) the effect of estradiol on the expression of the abovementioned molecules in endothelial cells, (ii) which type(s) of estrogen receptors mediate these effects, and (iii) the role of p21 in the estrogen-mediated regulation of the aforementioned factors. Human aortic endothelial cells (HAECs) were cultured with estradiol in the presence or absence of TNF-α. The expression of the aforementioned molecules was assessed by qRT-PCR and ELISA. Zymography was also performed. The experiments were repeated in either ERα- or ERβ-transfected HAECs and after silencing p21. HAECs expressed only the GPR-30 estrogen receptor. Estradiol, at low concentrations, decreased MMP-2 activity by 15-fold, increased LOX expression by 2-fold via GPR-30, and reduced MCP-1 expression by 3.5-fold via ERβ. The overexpression of ERα increased MCP-1 mRNA expression by 2.5-fold. In a low-grade inflammation state, lower concentrations of estradiol induced the mRNA expression of MCP-1 (3.4-fold) and MMP-9 (7.5-fold) and increased the activity of MMP-2 (1.7-fold) via GPR-30. Moreover, p21 silencing resulted in equivocal effects on the expression of the abovementioned molecules. Estradiol induced different effects regarding atherogenic plaque instability through different ERs. The balance of the expression of the various ER subtypes may play an important role in the paradoxical characterization of estrogens as both beneficial and harmful.

mPR-Specific Actions Influence Maintenance of the Blood–Brain Barrier (BBB)

Cerebral cavernous malformations (CCMs) are characterized by abnormally dilated intracranial microvascular sinusoids that result in increased susceptibility to hemorrhagic stroke. It has been demonstrated that three CCM proteins (CCM1, CCM2, and CCM3) form the CCM signaling complex (CSC) to mediate angiogenic signaling. Disruption of the CSC will result in hemorrhagic CCMs, a consequence of compromised blood–brain barrier (BBB) integrity. Due to their characteristically incomplete penetrance, the majority of CCM mutation carriers (presumed CCM patients) are largely asymptomatic, but when symptoms occur, the disease has typically reached a clinical stage of focal hemorrhage with irreversible brain damage. We recently reported that the CSC couples both classic (nuclear; nPRs) and nonclassic (membrane; mPRs) progesterone (PRG)-receptors-mediated signaling within the CSC-mPRs-PRG (CmP) signaling network in nPR(−) breast cancer cells. In this report, we demonstrate that depletion of any of the three CCM genes or treatment with mPR-specific PRG actions (PRG/mifepristone) results in the disruption of the CmP signaling network, leading to increased permeability in the nPR(−) endothelial cells (ECs) monolayer in vitro. Finally, utilizing our in vivo hemizygous Ccm mutant mice models, we demonstrate that depletion of any of the three CCM genes, in combination with mPR-specific PRG actions, is also capable of leading to defective homeostasis of PRG in vivo and subsequent BBB disruption, allowing us to identify a specific panel of etiological blood biomarkers associated with BBB disruption. To our knowledge, this is the first report detailing the etiology to predict the occurrence of a disrupted BBB, an indication of early hemorrhagic events.

The TWEAK/Fn14/CD163 axis-implications for metabolic disease

TWEAK (tumor necrosis factor-like weak inducer of apoptosis) is a member of the TNF superfamily that controls a multitude of cellular events including proliferation, migration, differentiation, apoptosis, angiogenesis, and inflammation. TWEAK control of these events is via an expanding list of intracellular signalling pathways which include NF-κB, ERK/MAPK, Notch, EGFR and AP-1. Two receptors have been identified for TWEAK - Fn14, which targets the membrane bound form of TWEAK, and CD163, which scavenges the soluble form of TWEAK. TWEAK appears to elicit specific events based on the receptor to which it binds, tissue type in which it is expressed, specific extrinsic conditions, and the presence of other cytokines. TWEAK signalling is protective in healthy tissues, but in chronic inflammatory states become detrimental to the tissue. Consistent data show a role for the TWEAK/FN14/CD163 axis in metabolic disease, chronic autoimmune diseases, and acute ischaemic stroke. Low circulating concentrations of soluble TWEAK are predictive of poor cardiovascular outcomes in those with and without diabetes. This review details the current understanding of the TWEAK/Fn14/CD163 axis as one of the chief regulators of immune signalling and its cell-specific role in metabolic disease development and progression.

Role of chemokine systems in cancer and inflammatory diseases

Chemokines are a large family of small secreted proteins that have fundamental roles in organ development, normal physiology, and immune responses upon binding to their corresponding receptors. The primary functions of chemokines are to coordinate and recruit immune cells to and from tissues and to participate in regulating interactions between immune cells. In addition to the generally recognized antimicrobial immunity, the chemokine/chemokine receptor axis also exerts a tumorigenic function in many different cancer models and is involved in the formation of immunosuppressive and protective tumor microenvironment (TME), making them potential prognostic markers for various hematologic and solid tumors. In fact, apart from its vital role in tumors, almost all inflammatory diseases involve chemokines and their receptors in one way or another. Modulating the expression of chemokines and/or their corresponding receptors on tumor cells or immune cells provides the basis for the exploitation of new drugs for clinical evaluation in the treatment of related diseases. Here, we summarize recent advances of chemokine systems in protumor and antitumor immune responses and discuss the prevailing understanding of how the chemokine system operates in inflammatory diseases. In this review, we also emphatically highlight the complexity of the chemokine system and explore its potential to guide the treatment of cancer and inflammatory diseases.

Targeting the CCL2-CCR2 axis for atheroprotection

Decades of research have established atherosclerosis as an inflammatory disease. Only recently though, clinical trials provided proof-of-concept evidence for the efficacy of anti-inflammatory strategies with respect to cardiovascular events, thus offering a new paradigm for lowering residual vascular risk. Efforts to target the inflammasome-interleukin-1β-interleukin-6 pathway have been highly successful, but inter-individual variations in drug response, a lack of reduction in all-cause mortality, and a higher rate of infections also highlight the need for a second generation of anti-inflammatory agents targeting atherosclerosis-specific immune mechanisms while minimizing systemic side effects. CC-motif chemokine ligand 2/monocyte-chemoattractant protein-1 (CCL2/MCP-1) orchestrates inflammatory monocyte trafficking between the bone marrow, circulation, and atherosclerotic plaques by binding to its cognate receptor CCR2. Adding to a strong body of data from experimental atherosclerosis models, a coherent series of recent large-scale genetic and observational epidemiological studies along with data from human atherosclerotic plaques highlight the relevance and therapeutic potential of the CCL2-CCR2 axis in human atherosclerosis. Here, we summarize experimental and human data pinpointing the CCL2-CCR2 pathway as an emerging drug target in cardiovascular disease. Furthermore, we contextualize previous efforts to interfere with this pathway, scrutinize approaches of ligand targeting vs. receptor targeting, and discuss possible pathway-intrinsic opportunities and challenges related to pharmacological targeting of the CCL2-CCR2 axis in human atherosclerotic disease.

Blood Biomarkers and 6- to 7-Year Childhood Outcomes Following Neonatal Encephalopathy

OBJECTIVE

This study aimed to profile the cytokine/chemokine response from day 0 to 7 in infants (≥36 weeks of gestational age) with neonatal encephalopathy (NE) and to explore the association with long-term outcomes.

STUDY DESIGN

This was a secondary study of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Neonatal Research Network randomized controlled trial of whole body hypothermia for NE. Eligible infants with moderate-severe NE were randomized to cooling or normothermia. Blood spots were collected on days 0 to 1, 2 to 4, and 6 to 7. Twenty-four cytokines/chemokines were measured using a multiplex platform. Surviving infants underwent neurodevelopmental assessment at 6 to 7 years. Primary outcome was death or moderate-severe impairment defined by any of the following: intelligence quotient <70, moderate-severe cerebral palsy (CP), blindness, hearing impairment, or epilepsy.

RESULTS

Cytokine blood spots were collected from 109 participants. In total 99 of 109 (91%) were assessed at 6 to 7 years; 54 of 99 (55%) developed death/impairment. Neonates who died or were impaired had lower early regulated upon activation normal T cell expressed and secreted (RANTES) and higher day 7 monocyte chemotactic protein (MCP)-1 levels than neonates who survived without impairment. Though TNF-α levels had no association with death/impairment, higher day 0 to 1 levels were observed among neonates who died/developed CP. On multiple regression analysis adjusted for center, treatment group, sex, race, and level of hypoxic ischemic encephalopathy, higher RANTES was inversely associated with death/impairment (odds ratio (OR): 0.31, 95% confidence interval [CI]: 0.13-0.74), while day seven MCP-1 level was directly associated with death/impairment (OR: 3.70, 95% CI: 1.42-9.61). Targeted cytokine/chemokine levels demonstrated little variation with hypothermia treatment.

CONCLUSION

RANTES and MCP-1 levels in the first week of life may provide potential targets for future therapies among neonates with encephalopathy.

KEY POINTS

· Elevation of specific cytokines and chemokines in neonates with encephalopathy has been noted along with increased risk of neurodevelopmental impairment in infancy.. · Cytokine/chemokines at <7 days were assessed among neonates in a trial of hypothermia for HIE.. · Neonates who died or were impaired at 6 to 7 years following hypoxic-ischemic encephalopathy had lower RANTES and higher MCP-1 levels than those who survived without impairment..

Pharmacological Targeting of the CCL2/CCR2 Axis for Atheroprotection: A Meta-Analysis of Preclinical Studies

BACKGROUND

The CCL2 (CC-chemokine ligand 2)/CCR2 (CC-chemokine receptor 2) axis governs monocyte recruitment to atherosclerotic lesions. Genetic and epidemiological studies show strong associations of CCL2 levels with atherosclerotic disease. Still, experimental studies testing pharmacological inhibition of CCL2 or CCR2 in atheroprone mice apply widely different approaches and report variable results, thus halting clinical translation.

METHODS

We systematically searched the literature for studies employing pharmacological CCL2/CCR2 blockade in atheroprone mice and meta-analyzed their effects on lesion size and morphology.

RESULTS

In a meta-analysis of 14 studies testing 11 different agents, CCL2/CCR2 blockade attenuated atherosclerotic lesion size in the aortic root or arch (g=-0.75 [-1.17 to -0.32], P=6×10^-4; N=171/171 mice in experimental/control group), the carotid (g=-2.39 [-4.23 to -0.55], P=0.01; N=24/25), and the femoral artery (g=-2.38 [-3.50 to -1.26], P=3×10^-5; N=10/10). Furthermore, CCL2/CCR2 inhibition reduced intralesional macrophage accumulation and increased smooth muscle cell content and collagen deposition. The effects of CCL2/CCR2 inhibition on lesion size correlated with reductions in plaque macrophage accumulation, in accord with a prominent role of CCL2/CCR2 signaling in monocyte recruitment. Subgroup analyses showed comparable efficacy of different CCL2- and CCR2-inhibitors in reducing lesion size and intralesional macrophages. The quality assessment revealed high risk of detection bias due to lack of blinding during outcome assessment, as well as evidence of attrition and reporting bias.

CONCLUSIONS

Preclinical evidence suggests that pharmacological targeting of CCL2 or CCR2 might lower atherosclerotic lesion burden, but the majority of existing studies suffer major quality issues that highlight the need for additional high-quality research.

Evaluating the Causal Effects of TIMP-3 on Ischaemic Stroke and Intracerebral Haemorrhage: A Mendelian Randomization Study

Aim: Since tissue inhibitors of matrix metalloproteinase 3 (TIMP-3) was reported to be a potential risk factor of atherosclerosis, aneurysm, hypertension, and post-ischaemic neuronal injury, it may also be a candidate risk factor of stress. Therefore, this study was designed to explore the causal role of TIMP-3 in the risk of ischaemic stroke (IS) and intracerebral haemorrhage (ICH), which are the two main causes of stress via this Mendelian Randomisation (MR) study. Methods: The summarised data of TIMP-3 level in circulation was acquired from the Cooperative Health Research in the Region of Augsburg public database and the outcome of IS and ICH was obtained from genome-wide association studies conducted by MEGASTROKE and the International Stroke Genetics Consortium, respectively. Five statistical methods including inverse-variance weighting, weighted-median analysis, MR-Egger regression, MR Pleiotropy RESidual Sum and Outlier test, and MR-Robust Adjusted Profile Score were applied to evaluate the causal role of TIMP-3 in the occurrence of IS and ICH. Inverse-variance weighting was applied for assessing causality. Furthermore, heterogeneity and pleiotropic tests were utilised to confirm the reliability of this study. Results: We found that TIMP-3 could be a positively causal relationship with the incidence of IS (OR = 1.026, 95% CI: 1.007-1.046, p = 0.0067), especially for the occurrence of small vessel stroke (SVS; OR = 1.045, 95% CI: 1.016-1.076, p = 0.0024). However, the causal effects of TIMP-3 on another IS subtype cardioembolic stroke (CES; OR = 1.049, 95% CI: 1.006-1.094, p = 0.024), large artery stroke (LAS; OR = 1.0027, 95% CI: 0.9755-1.0306, p = 0.849) and ICH (OR = 0.9900, 95% CI: 0.9403-1.0423, p = 0.701), as well as ICH subtypes were not observed after Bonferroni corrections (p = 0.00714). Conclusion: Our results revealed that high levels of circulating TIMP-3 causally increased the risk of developing IS and SVS, but not CES, LAS, ICH, and all ICH subtypes. Further investigation is required to elucidate the underlying mechanism.

Stroke Genetics: Discovery, Insight Into Mechanisms, and Clinical Perspectives

Stroke is the second leading cause of death worldwide and a complex, heterogeneous condition. In this review, we provide an overview of the current knowledge on monogenic and multifactorial forms of stroke, highlighting recent insight into the continuum between these. We describe how, in recent years, large-scale genome-wide association studies have enabled major progress in deciphering the genetic basis for stroke and its subtypes, although more research is needed to interpret these findings. We cover the potential of stroke genetics to reveal novel pathophysiological processes underlying stroke, to accelerate the discovery of new therapeutic approaches, and to identify individuals in the population who are at high risk of stroke and could be targeted for tailored preventative interventions.

Immune Pathways in Etiology, Acute Phase, and Chronic Sequelae of Ischemic Stroke

Inflammation and immune mechanisms are crucially involved in the pathophysiology of the development, acute damage cascades, and chronic course after ischemic stroke. Atherosclerosis is an inflammatory disease, and, in addition to classical risk factors, maladaptive immune mechanisms lead to an increased risk of stroke. Accordingly, individuals with signs of inflammation or corresponding biomarkers have an increased risk of stroke. Anti-inflammatory drugs, such as IL (interleukin)-1β blockers, methotrexate, or colchicine, represent attractive treatment strategies to prevent vascular events and stroke. Lately, the COVID-19 pandemic shows a clear association between SARS-CoV2 infections and increased risk of cerebrovascular events. Furthermore, mechanisms of both innate and adaptive immune systems influence cerebral damage cascades after ischemic stroke. Neutrophils, monocytes, and microglia, as well as T and B lymphocytes each play complex interdependent roles that synergize to remove dead tissue but also can cause bystander injury to intact brain cells and generate maladaptive chronic inflammation. Chronic systemic inflammation and comorbid infections may unfavorably influence both outcome after stroke and recurrence risk for further stroke. In addition, stroke triggers specific immune depression, which in turn can promote infections. Recent research is now increasingly addressing the question of the extent to which immune mechanisms may influence long-term outcome after stroke and, in particular, cause specific complications such as poststroke dementia or even poststroke depression.

The Role of CCL2/CCR2 Axis in Cerebral Ischemia-Reperfusion Injury and Treatment: From Animal Experiments to Clinical Trials

C-C motif chemokine ligand 2 (CCL2) is a member of the monocyte chemokine protein family, which binds to its receptor CCR2 to induce monocyte infiltration and mediate inflammation. The CCL2/CCR2 signaling pathway participates in the transduction of neuroinflammatory information between all types of cells in the central nervous system. Animal studies and clinical trials have shown that CCL2/CCR2 mediate the pathological process of ischemic stroke, and a higher CCL2 level in serum is associated with a higher risk of any form of stroke. In the acute phase of cerebral ischemia-reperfusion, the expression of CCL2/CCR2 is increased in the ischemic penumbra, which promotes neuroinflammation and enhances brain injury. In the later phase, it participates in the migration of neuroblasts to the ischemic area and promotes the recovery of neurological function. CCL2/CCR2 gene knockout or activity inhibition can reduce the nerve inflammation and brain injury induced by cerebral ischemia-reperfusion, suggesting that the development of drugs regulating the activity of the CCL2/CCR2 signaling pathway could be used to prevent and treat the cell injury in the acute phase and promote the recovery of neurological function in the chronic phase in ischemic stroke patients.

Circulating Interleukin-6 Levels and Incident Ischemic Stroke: A Systematic Review and Meta-analysis of Prospective Studies

BACKGROUND AND OBJECTIVES

Human genetic studies support a key role of interleukin-6 (IL-6) in the pathogenesis of ischemic stroke. However, there are only limited data from observational studies exploring circulating IL-6 levels as a risk factor for ischemic stroke. We set out to perform a systematic review and meta-analysis of aggregate data on cohort studies to determine the magnitude and shape of the association between circulating IL-6 levels and risk of incident ischemic stroke in the general population.

METHODS

Following the PRISMA guidelines, we systematically screened the PubMed search engine from inception to March 2021 for population-based prospective cohort studies exploring the association between circulating IL-6 levels and risk of incident ischemic stroke. We pooled association estimates for ischemic stroke risk with random-effects models and explored nonlinear effects in dose-response meta-analyses. Risk of bias was assessed with the Newcastle-Ottawa Scale (NOS). We used funnel plots and trim-to-fill analyses to assess publication bias.

RESULTS

We identified 11 studies (n = 27,411 individuals; 2,669 stroke events) meeting our eligibility criteria. Mean age of all included participants was 60.5 years and 54.8% were female. Overall, quality of the included studies was high (median 8 out of 9 NOS points, interquartile range 7-9). In meta-analyses, 1 SD increment in circulating log-transformed IL-6 levels was associated with a 19% increase in risk of incident ischemic stroke over a mean follow-up of 12.4 years (relative risk 1.19; 95% confidence interval 1.10 to 1.28). A dose-response meta-analysis showed a linear association between circulating IL-6 levels and ischemic stroke risk. There was only moderate heterogeneity and the results were consistent in sensitivity analyses restricted to studies of low risk of bias and studies fully adjusting for demographic and vascular risk factors. The results also remained stable following adjustment for publication bias.

DISCUSSION

Higher circulating IL-6 levels in community-dwelling individuals are associated with higher long-term risk of incident ischemic stroke in a linear pattern and independently of conventional vascular risk factors. Along with findings from genetic studies and clinical trials, these results provide additional support for a key role of IL-6 signaling in ischemic stroke.

Inflammatory Cytokines and Risk of Ischemic Stroke: A Mendelian Randomization Study

Background: Observational studies have revealed the association between some inflammatory cytokines and the occurrence of ischemic stroke, but the causal relationships remain unclear.

Methods: We conducted a two-sample Mendelian randomization (MR) analysis to assess the causal effects of thirty inflammatory cytokines and the risk of ischemic stroke. For exposure data, we collected genetic variants associated with inflammatory cytokines as instrumental variables (IVs) from a genome-wide association study (GWAS) meta-analysis from Finland (sample size up to 8,293). For the outcome data, we collected summary data of ischemic stroke from a large-scale GWAS meta-analysis involved 17 studies (34,217 cases and 406,111 controls). We further performed a series of sensitivity analyses as validation of primary MR results.

Results: According to the primary MR estimations and further sensitivity analyses, we established one robust association after Bonferroni correction: the odds ratio (95% CI) per unit change in genetically increased IL-4 was 0.84 (0.89–0.95) for ischemic stroke. The chemokine MCP3 showed a nominally significant association with ischemic stroke risk (OR: 0.93, 95% CI: 0.88–0.99, unadjusted p < 0.05). There was no evidence of a causal effect of other inflammatory cytokines and the risk of ischemic stroke.

Conclusions: Our study suggested that genetically increased IL-4 levels showed a protective effect on the risk of ischemic stroke, which provides important new insights into the potential therapeutic target for preventing ischemic stroke.

Hematopoietic Cell-Specific SLC37A2 Deficiency Accelerates Atherosclerosis in LDL Receptor-Deficient Mice

Macrophages play a central role in the pathogenesis of atherosclerosis. Our previous study demonstrated that solute carrier family 37 member 2 (SLC37A2), an endoplasmic reticulum-anchored phosphate-linked glucose-6-phosphate transporter, negatively regulates macrophage Toll-like receptor activation by fine-tuning glycolytic reprogramming in vitro. Whether macrophage SLC37A2 impacts in vivo macrophage inflammation and atherosclerosis under hyperlipidemic conditions is unknown. We generated hematopoietic cell-specific SLC37A2 knockout and control mice in C57Bl/6 Ldlr^−/− background by bone marrow transplantation. Hematopoietic cell-specific SLC37A2 deletion in Ldlr^−/− mice increased plasma lipid concentrations after 12-16 wks of Western diet induction, attenuated macrophage anti-inflammatory responses, and resulted in more atherosclerosis compared to Ldlr^−/− mice transplanted with wild type bone marrow. Aortic root intimal area was inversely correlated with plasma IL-10 levels, but not total cholesterol concentrations, suggesting inflammation but not plasma cholesterol was responsible for increased atherosclerosis in bone marrow SLC37A2-deficient mice. Our in vitro study demonstrated that SLC37A2 deficiency impaired IL-4-induced macrophage activation, independently of glycolysis or mitochondrial respiration. Importantly, SLC37A2 deficiency impaired apoptotic cell-induced glycolysis, subsequently attenuating IL-10 production. Our study suggests that SLC37A2 expression is required to support alternative macrophage activation in vitro and in vivo. In vivo disruption of hematopoietic SLC37A2 accelerates atherosclerosis under hyperlipidemic pro-atherogenic conditions.

Monocyte chemoattractant protein-1 and hypertension: An overview

BACKGROUND

The association between hypertension and cardiovascular disease (CVD) has been increasingly studied through early inflammatory biomarkers. The monocyte chemoattractant protein-1 (MCP-1) is the main chemokine implicated in the inflammatory endothelial process, attracting monocytes and macrophages to the atherosclerotic plaque.

METHODS

We reviewed the main observational studies that have analyzed serum MCP-1 in patients with hypertension regardless of CVD, relating them to target organ damage (TOD).

RESULTS

As endothelial dysfunction continues and TOD accumulates, MCP-1 has been perpetuated at higher levels. The relationship between this chemokine and the increase in comorbidities, such as chronic kidney disease, dyslipidaemia, diabetes, and coronary artery disease, became clearer from the observational studies. However, patients with such morbidities use medications with potential anti-inflammatory effects.

CONCLUSION

There is no normal threshold of MCP-1 for the healthy population, nor a uniform curve pattern, due to a balance between genetic factors, age, gender, comorbidities, TOD, and anti-inflammatory effects of drugs. In fact, MCP-1 seems to have a promising role as a tool for further improvement in cardiovascular risk stratification, as prognostic studies have demonstrated an association with fatal and non-fatal cardiovascular outcomes, regardless of other clinical and laboratory predictors.

Childhood Obesity and Risk of Stroke: A Mendelian Randomisation Analysis

Background: The causal relationship between childhood obesity and stroke remains unclear. Our objective was to elucidate the causal relationship between childhood obesity and the risk of stroke and its subtypes by performing Mendelian randomisation (MR) analyses.

Methods: Genetic instruments for childhood obesity were obtained from a genome-wide association study (GWAS) of 13,848 European participants. Summary level data for stroke, intracerebral haemorrhage, ischaemic stroke (IS), and its subtypes were evaluated using the MEGASTROKE GWAS dataset, which included 446,696 European adults. Inverse-variance weighting, weighted-median analysis, MR-Egger regression, MR Pleiotropy RESidual Sum and Outlier test (MR-PRESSO), and MR-Robust Adjusted Profile Score were applied in this MR analysis. The leave-one-out sensitivity test, MR-PRESSO Global test, and Cochran’s Q test were conducted to confirm the accuracy and robustness of our results.

Results: Genetic evaluations revealed that childhood obesity was associated with a higher risk of stroke (OR = 1.04, 95%CI: 1.01–1.07, p = 0.005) and IS (OR = 1.05, 95%CI: 1.02–1.08, p = 0.003), but not with intracerebral haemorrhage (ICH, OR = 0.93, 95%CI: 0.80–1.09, p = 0.39). In the subtype analysis, childhood obesity was also associated with large artery stroke (LAS, OR = 1.12, 95%CI: 1.02–1.22, p = 0.016) but not with cardioembolic stroke (OR = 1.06, 95%CI: 0.96–1.18, p = 0.21) and small vessel stroke (OR = 1.06, 95%CI: 0.98–1.15, p = 0.17). These results were stable in the sensitivity analysis and remained significant after Bonferroni correction.

Conclusion: Our study provides evidence that childhood obesity is associated with a higher risk of stroke, IS, and LAS. The prevention of stroke, especially IS and LAS, should be promoted in populations with childhood obesity.

Cell Type Dependent Suppression of Inflammatory Mediators by Myocardin Related Transcription Factors

Myocardin related transcription factors (MRTFs: MYOCD/myocardin, MRTF-A, and MRTF-B) play a key role in smooth muscle cell differentiation by activating contractile genes. In atherosclerosis, MRTF levels change, and most notable is a fall of MYOCD. Previous work described anti-inflammatory properties of MRTF-A and MYOCD, occurring through RelA binding, suggesting that MYOCD reduction could contribute to vascular inflammation. Recent studies have muddled this picture showing that MRTFs may show both anti- and pro-inflammatory properties, but the basis of these discrepancies remain unclear. Moreover, the impact of MRTFs on inflammatory signaling pathways in tissues relevant to human arterial disease is uncertain. The current work aimed to address these issues. RNA-sequencing after forced expression of myocardin in human coronary artery smooth muscle cells (hCASMCs) showed reduction of pro-inflammatory transcripts, including CCL2, CXCL8, IL6, and IL1B. Side-by-side comparison of MYOCD, MRTF-A, and MRTF-B in hCASMCs, showed that the anti-inflammatory impact was shared among MRTFs. Correlation analyses using human arterial transcriptomic datasets revealed negative correlations between MYOCD, MRTFA, and SRF, on the one hand, and the inflammatory transcripts, on the other. A pro-inflammatory drive from lipopolysaccharide, did not change the size of the suppressive effect of MRTF-A in hCASMCs on either mRNA or protein levels. To examine cell type-dependence, we compared the anti-inflammatory impact in hCASMCs, with that in human bladder SMCs, in endothelial cells, and in monocytes (THP-1 cells). Surprisingly, little anti-inflammatory activity was seen in endothelial cells and monocytes, and in bladder SMCs, MRTF-A was pro-inflammatory. CXCL8, IL6, and IL1B were increased by the MRTF-SRF inhibitor CCG-1423 and by MRTF-A silencing in hCASMCs, but depolymerization of actin, known to inhibit MRTF activity, had no stimulatory effect, an exception being IL1B. Co-immunoprecipitation supported binding of MRTF-A to RelA, supporting sequestration of this important pro-inflammatory mediator as a mechanism. Dexamethasone treatment and silencing of RelA (by 76 ± 1%) however only eliminated a fraction of the MRTF-A effect (≈25%), suggesting mechanisms beyond RelA binding. Indeed, SRF silencing suggested that MRTF-A suppression of IL1B and CXCL8 depends on SRF. This work thus supports an anti-inflammatory impact of MRTF-SRF signaling in hCASMCs and in intact human arteries, but not in several other cell types.

Quantile-specific heritability of monocyte chemoattractant protein-1, and relevance to rs1024611-disease interactions

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) concentrations are 34% to 47% heritable. Larger -2518 G/A (rs1024611) genotypes differences are reported for: 1) MCP-1 production in stimulated vs. basal cells; and 2) MCP-1 concentrations in diseased (sepsis, brain abscess, hepatitis B virus, Alzheimer's disease, Behcet's disease, and systemic lupus erythematosus) vs. healthy patients. Those results suggest that the -2518 G/A effect size may depend on whether the phenotype is high or low relative to its distribution (quantile-dependent expressivity).

METHOD

To test whether quantile-dependent expressivity applies more broadly to genetic influences on MCP-1 concentrations, quantile-specific offspring-parent (β_OP) and full-sib regression slopes (β_FS) were estimated by applying quantile regression to the age- and sex-adjusted serum MCP-1 concentrations of Framingham Heart Study families. Quantile-specific heritabilities were calculated as h² = 2β_OP/(1 + r_spouse) and h²={(1 + 8r_spouseβ_FS)^0.5-1}/(2r_spouse)).

RESULTS

Heritability (h² ± SE) of MCP-1 concentrations increased from 0.15 ± 0.05 at the 10th percentile of the MCP-1 distribution, 0.23 ± 0.04 at the 25th, 0.32 ± 0.05 at the 50th, 0.43 ± 0.07 at the 75th, and 0.44 ± 0.07 at the 90th percentile, or an 0.0041 ± 0.0009 increase for each one-percent increment in the MCP-1 distribution (P_{linear trend} = 2.4 × 10^-5) when estimated from β_OP, and (P_{linear trend} = 7.7 × 10^-9) when estimated from β_FS. Compared to the 10th percentile, β_OP-estimated h² was 3-fold greater at the 90th percentile (P_difference = 0.0003), and 6.9-fold greater when estimated from β_FS (P_difference = 3.3 × 10^-6). Re-analysis of in vivo comparison of MCP-1 concentrations in controls vs. patients with MCP-1-elevating conditions, and in vitro studies of MCP-1 production in basal vs. stimulated cells, show rs1024611 genotypes differences that were consistent with quantile-dependent expressivity.

CONCLUSION

The heritability of circulating MCP-1 concentrations is quantile-dependent.

Key Chemokine Pathways in Atherosclerosis and Their Therapeutic Potential

The search to improve therapies to prevent or treat cardiovascular diseases (CVDs) rages on, as CVDs remain a leading cause of death worldwide. Here, the main cause of CVDs, atherosclerosis, and its prevention, take center stage. Chemokines and their receptors have long been known to play an important role in the pathophysiological development of atherosclerosis. Their role extends from the initiation to the progression, and even the potential regression of atherosclerotic lesions. These important regulators in atherosclerosis are therefore an obvious target in the development of therapeutic strategies. A plethora of preclinical studies have assessed various possibilities for targeting chemokine signaling via various approaches, including competitive ligands and microRNAs, which have shown promising results in ameliorating atherosclerosis. Developments in the field also include detailed imaging with tracers that target specific chemokine receptors. Lastly, clinical trials revealed the potential of various therapies but still require further investigation before commencing clinical use. Although there is still a lot to be learned and investigated, it is clear that chemokines and their receptors present attractive yet extremely complex therapeutic targets. Therefore, this review will serve to provide a general overview of the connection between various chemokines and their receptors with atherosclerosis. The different developments, including mouse models and clinical trials that tackle this complex interplay will also be explored.

Atherosclerosis: The Culprit and Co-victim of Vascular Dementia

Vascular dementia (VD), a cerebrovascular disease which causes cognitive impairment, is one of the significant factors that affects the quality of senectitude. Atherosclerosis (AS) is a chronic inflammatory syndrome and closely associated with VD. Analyzing the role of AS in VD contribute greatly to its early detection and prevention, but their relationship has not been integrated into a complete network. This review summarizes AS biomarkers as VD predictors for the first time and describes the direct mechanisms of AS causing VD from five aspects: vascular morphogenesis, hemodynamic change, neurovascular unit damage (NVU), oxidative stress, and microRNA (miRNA). Finally, it discriminates the relationship between AS and VD in common risk factors which can be disease or some molecules. In particular, these data imply that the role of AS in VD is not only a pathogenic factor but also a comorbidity in VD. This review aims to bring new ideas for the prediction and treatment of VD.

Mendelian Randomization Studies in Stroke: Exploration of Risk Factors and Drug Targets With Human Genetic Data

Elucidating the causes of stroke is key to developing effective preventive strategies. The Mendelian randomization approach leverages genetic variants related to an exposure of interest to investigate the effects of varying that exposure on disease risk. The random allocation of genetic variants at conception reduces confounding from environmental factors and thus strengthens causal inference, analogous to treatment allocation in a randomized controlled trial. With the recent explosion in the availability of human genetic data, Mendelian randomization has proven a valuable tool for studying risk factors for stroke. In this review, we provide an overview of recent developments in the application of Mendelian randomization to unravel the pathophysiology of stroke subtypes and identify therapeutic targets for clinical translation. The approach has offered novel insight into the differential effects of risk factors and antihypertensive, lipid-lowering, and anticoagulant drug classes on risk of stroke subtypes. Analyses have further facilitated the prioritization of novel drug targets, such as for inflammatory pathways underlying large artery atherosclerotic stroke and for the coagulation cascade that contributes to cardioembolic stroke. With continued methodological advances coupled with the rapidly increasing availability of genetic data related to a broad range of stroke phenotypes, the potential for Mendelian randomization in this context is expanding exponentially.

Cytokines, brain proteins, and growth factors in acute stroke patients: A pilot study

BACKGROUND

Immunomodulation and cell signaling involve several cytokines, proteins, and other mediators released in response to the trauma, inflammation, or other insults to the central nervous system. This pilot study is part of the registry designed to evaluate the temporal trends among these molecules after an acute ischemic stroke (AIS) in patients.

METHODS

Twelve AIS patients were enrolled within 24 hours of the symptoms onset. Two sets of plasma samples were collected: First at admission and second at 24 hours after admission. Cytokines/chemokines and other inflammatory molecules were measured using multiplex assay kit.

RESULTS

An increased trend in IL-6 (22 vs. 34 pg/ml), IL-8/CXCL8 (87 vs. 98 pg/ml), MMP-9 (16225 vs. 18450 pg/ml), and GMF-β (999 vs. 3739 pg/ml) levels was observed overtime after an AIS. Patients ≤60 years had lower levels of plasma MCP-1/CCL2 (50-647 vs. 150-1159 pg/ml), IL-6 (9-25 vs. 20-68 pg/ml), and IL-8 (30- 143 vs. 72-630 pg/ml), when compared with patients >60 years old.

CONCLUSION

Cytokines/chemokines and other inflammatory mediators play an important role in the pathogenesis of stroke in addition to mediating poststroke inflammation. Further research is needed to evaluate and characterize the cumulative trends of these mediators for the clinical prognosis or as surrogate biomarkers.

Exploring the Impact of Cerebrovascular Disease and Major Depression on Non-diseased Human Tissue Transcriptomes

Background

The development of complex diseases is contributed by the combination of multiple factors and complicated interactions between them. Inflammation has recently been associated with many complex diseases and may cause long-term damage to the human body. In this study, we examined whether two types of complex disease, cerebrovascular disease (CVD) or major depression (MD), systematically altered the transcriptomes of non-diseased human tissues and whether inflammation is linked to identifiable molecular signatures, using post-mortem samples from the Genotype-Tissue Expression (GTEx) project.

Results

Following a series of differential expression analyses, dozens to hundreds of differentially expressed genes (DEGs) were identified in multiple tissues between subjects with and without a history of CVD or MD. DEGs from these disease-associated tissues-the visceral adipose, tibial artery, caudate, and spinal cord for CVD; and the hypothalamus, putamen, and spinal cord for MD-were further analyzed for functional enrichment. Many pathways associated with immunological events were enriched in the upregulated DEGs of the CVD-associated tissues, as were the neurological and metabolic pathways in DEGs of the MD-associated tissues. Eight gene-tissue pairs were found to overlap with those prioritized by our transcriptome-wide association studies, indicating a potential genetic effect on gene expression for circulating cytokine phenotypes.

Conclusion

Cerebrovascular disease and major depression cause detectable changes in the gene expression of non-diseased tissues, suggesting that a possible long-term impact of diseases, lifestyles and environmental factors may together contribute to the appearance of "transcriptomic scars" on the human body. Furthermore, inflammation is probably one of the systemic and long-lasting effects of cerebrovascular events.

Emerging Exosomes and Exosomal MiRNAs in Spinal Cord Injury

Acute spinal cord injury (SCI) is a serious traumatic event to the spinal cord with considerable morbidity and mortality. This injury leads to short- and long-term variations in the spinal cord, and can have a serious effect on the patient's sensory, motor, or autonomic functions. Due to the complicated pathological process of SCI, there is currently no successful clinical treatment strategy. Exosomes, extracellular vesicles (EVs) with a double-layer membrane structure of 30-150 nm diameter, have recently been considered as critical mediators for communication between cells and tissues by transferring proteins, lipids, and nucleic acids. Further studies verified that exosomes participate in the pathophysiological process of several diseases, including cancer, neurodegenerative diseases, and cardiovascular diseases, and could have a significant impact in their treatment. As natural carriers of biologically active cargos, exosomes have emerged as pathological mediators of SCI. In this review article, we critically discuss the functions of exosomes as intracellular mediators and potential treatments in SCI and provide an outlook on future research.