Role In Carotid Atherosclerosis Research Articles

M6A plays a potential role in carotid atherosclerosis by modulating immune cell modification and regulating aging-related genes

RNA N6-methyladenosine (m6A) regulators play essential roles in diverse biological processes, including immune responses. Mounting evidence suggests that their dysregulation is intricately linked to numerous diseases. However, the role of m6A-associated genes in carotid atherosclerosis and their relationship with aging and immune cells remain unclear. Analyze the expression profiles of m6A-related genes in carotid atherosclerosis-related datasets. Based on the expression patterns of m6A-related genes, perform consistent clustering analysis of carotid atherosclerosis samples and investigate associated immune cell infiltration patterns and aging characteristics. Develop an m6A prediction model specific to carotid atherosclerosis and analyze the relationships between immune cells infiltration and aging features. The m6A methylation modification level exhibited a substantial decrease in early-stage carotid atherosclerosis samples compared to late-stage carotid atherosclerosis samples. Subsequently, two distinct m6A subtypes were defined through consensus clustering analysis, with the lower m6A modification level group showing associations with heightened immune cell infiltration and increased expression of aging-related genes. A model composed of five m6A-related genes was formulated, and the results indicated that this model possesses effective predictive and therapeutic capabilities for carotid atherosclerosis. Furthermore, the downregulation of YTHDC1 expression resulted in elevated expression of inflammatory factors and a decrease in the expression of the aging-related gene RGN. Single-cell data analysis suggests that the reduced expression of YTHDC1 may decrease the degradation of inflammation-related factors in macrophages, leading to a highly inflammatory state in the carotid artery wall. Furthermore, the sustained release of inflammatory factors may increase the expression of the aging-related gene RGN in vascular smooth muscle cells, further exacerbating the progression of atherosclerosis. A reduced level of m6A methylation modification could enhance inflammation and expedite cellular aging, thereby contributing to the development of carotid atherosclerosis.

The roles and mechanisms of miR-26 derived from exosomes of adipose-derived stem cells in the formation of carotid atherosclerotic plaque.

This study explored the serum concentrations of miR-26 in patients with carotid atherosclerosis (CAS) and defined the roles and mechanisms of miR-26 derived from the exosomes of adipose-derived stem cells (ADSC-exos). The carotid artery width was diagnosed by ultrasound examination in patients with different degrees of CAS. The serum levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in patients were detected by biochemistry. The serum levels of miR-26 were determined by quantitative polymerase chain reaction (qPCR). A model of CAS in ApoE-/- mice fed with a rich-fat diet was established to analyze the regulatory effects of serum miR-26 on blood lipids in mice. Adipose mesenchymal stem cell lines transfected with miR-26 were established. The regulatory relationship between the expression levels of inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β, and the expression levels of miR-26 in the supernatant of each group of cells was determined by qPCR. The ADSC-exos were extracted from ADSCs and injected into model mice through the tail vein. The therapeutic effect of ADSCs expressing miR-26 on model mice was evaluated by detecting the levels of inflammatory factors and blood lipids in the serum of the mice. The degree of atherosclerosis (AS) was positively associated with the intima-media thickness (IMT) of the carotid artery. The serum levels of miR-26 in patients were inversely correlated with the levels of blood lipids (TC, TG, and LDL-C), and positively correlated with HDL-C levels. Similarly, in the CAS mouse model, the serum levels of miR-26 were inversely correlated with the levels of blood lipids (TC, TG, and LDL-C), and positively correlated with HDL-C level. In ADSCs transfected with miR-26, the miR-26 expression in the cell supernatant was negatively regulated by the expression of inflammatory factors, TNF-α, IL-6, and IL-1β, in the cell supernatant. ADSC-exos expressing miR-26 has positive effects on correcting blood lipids and inflammatory factors in the mouse model of CAS. miR-26 has an active role in CAS and may be a novel target for the treatment of CAS in the future.

CAN WE USE NEUROTROPHINS FOR CAROTID PLAQUE VULNERABILITY ASSESSMENT – IVUS VH CASE SERIES

Objective: Defining carotid atherosclerotic plaque vulnerability is problematic. The combination between imaging and biomarkers may be of practical significance for future assessment of extracranial stenoses. Brain derived neurotrophic factor (BDNF) and neuronal growth factor (NGF) are neurotrophins. There are some studies, which suggest association between endothelial dysfunction and circulating BDNF, impaired neurotrophins’ endothelial secretion in atherosclerosis and correlation between BDNF concentration and Agatson’s score, as well as coronary plaque vulnerability. Neurotrophins also play important role in cerebral functioning. Their role in carotid atherosclerosis is not known. Design and method: We share the results of 13 patients with angiographically significant carotid stenoses. The plaque morphology was assessed with IVUS VH and we evaluated their serum BDNF and NGF concertation. All the patients were without coronary artery disease or fully revascularized, as well as without significant or symptomatic peripheral artery disease. We had the results for BDNF and NGF from a reference group without any atherosclerotic disease. SPSS (IBM) was used for the statistical analysis, p < 0.05, CI 95%. Results: The patients with significant carotid stenoses had lower mean BDNF values than the reference group. There was correlation between luminal diameter and BDNF (p = 0.049; r = -0.605), total Ca2+ area (mm2) and BDNF (r = 0.681, p = 0.021), Proximal Ca2+area and BDNF (p = 0.007, r = 0.784), Necrotic core % in the proximal plaque area and NGF (r = 0.891, p = 0.001) Conclusions: BDNF concentration was negatively correlated with the maximal values for minimal luminal diameter and positively with total Ca2+ plaque area, t.i. with plaque stability. We found positive correlation with necrotic core % and NGF values. This case series is small, and a much larger sample is needed to define precisely any association. Nevertheless, this is a beginning of the study for the potential role of neurotrophins in carotid plaque morphology, either by their local endothelial secretion or by modification of their central secretion from the altered cerebral hemodynamics. They may be both markers and factors for carotid plaque vulnerability. The work was partially funded by a Research GRANT 2020 number 133 from Medical University Sofia, Bulgaria.

Contribution of FBLN5 to Unstable Plaques in Carotid Atherosclerosis via mir128 and mir532–3p Based on Bioinformatics Prediction and Validation

FBLN5, a member of the short fibulins in the fibulin family of extracellular matrix/matricellular proteins, is involved in interactions with components of the basement membrane and extracellular matrix proteins. It plays key roles in endothelial tissues in many vascular diseases. In this study, the relationship between FBLN5 and carotid atherosclerotic plaque stability as well as the regulatory roles of miRNAs were evaluated. Differential gene expression analyses and weighted gene co-expression network analysis (WGCNA) based on the GSE163154 dataset (including 16 samples without intraplaque hemorrhage and 27 samples with intraplaque hemorrhage) in GEO revealed that FBLN5 is related to plaque stability and is the most significantly differentially expressed gene. LASSO regression was used to evaluate genes obtained from the intersection of differentially expressed genes and clinically significant modules identified by WGCNA. A prediction model based on eight genes, including FBLN5, was constructed and showed an accuracy of 0.951 based on an ROC analysis. Low FBLN5 expression in plaque tissues was confirmed by immunohistochemistry and western blotting. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analyses showed that FBLN5 acted mainly by the maintenance of the cellular matrix and reactive oxygen species production. miRNAs upstream of these eight predictive genes, including FBLN5, were identified and used to construct a network diagram. These results revealed that hsa-mir-128 and hsa-mir-532–3p were upstream regulatory factors of FBLN5, as verified by PCR assays of human plaque tissues demonstrating that both miRNAs were significantly up-regulated. Therefore, FBLN5 may play an important role in carotid atherosclerosis via hsa-mir-128 and hsa-mir-532–3p as well as become an essential target for treatment.

Association of Helicobacter pylori Infection With Carotid Atherosclerosis in a Northern Chinese Population: A Cross-Sectional Study.

Numerous studies have shown that Helicobacter pylori (HP) infection may be involved in the development of carotid atherosclerosis (CAS), but this conclusion is still controversial. The aim of this study was to explore whether there is a positive association between HP infection and CAS occurrence. We collected data on demographic characteristics, lifestyle, and disease history of the participants by questionnaire. We obtained clinical anthropometric data and blood samples of the participants from clinical examinations and laboratory work. The 13C urea breath test (13C-UBT) was performed to assess the HP infection status, and carotid ultrasonography was used to diagnose the CAS and plaque types. Univariate analysis and multivariate logistic regression were used to identify the relationship between HP infection and CAS. A total of 1,424 participants were recruited for this study. A total of 740 HP-positive individuals and 684 HP-negative individuals were identified, and 345 participants were diagnosed with CAS. The prevalence of CAS was higher in the HP-positive group (26.4%) than in the HP-negative group (21.7%) (P < 0.05). A significantly higher prevalence of carotid intima-media thickening, carotid plaque, and carotid stenosis was identified in the HP-positive group than in the HP-negative group (P < 0.05). There was no significant difference in the detection rate of unstable plaques between the HP-positive and HP-negative groups (P > 0.05). In multivariate models adjusted for covariates, HP infection showed a positive association with CAS, independent of other risk factors (ORs range: 1.283–1.333, P < 0.05). HP infection independently accounted for approximately 5% of the CAS risk in the absence of other cardiovascular risk factors. A positive association between HP infection and CAS was demonstrated in this study. HP infection might be an independent risk factor for CAS. Although the effect of HP infection on CAS observed in our study was less than that of traditional risk factors, we believe that this is an indispensable advance in the etiological study of CAS. These results imply that the microbial population might play an essential role in CAS, which provides a new perspective for the primary prevention of CAS.

Expression of Resistin, Chemerin, and Chemerin's Receptor in the Unstable Carotid Atherosclerotic Plaque.

Unstable carotid plaques are a common cause of ischemic strokes. Identifying markers that reflect/contribute to plaque instability has become a prominent focus in cardiovascular research. The adipokines, resistin and chemerin, and ChemR23 (chemerin receptor), may play a role in carotid atherosclerosis, making them potential candidates to assess plaque instability. However, the expression and interrelationship of resistin and chemerin (and ChemR23) protein and mRNA within the carotid atherosclerotic plaque remains elusive. Thus, we investigated herein, the association between plaque mRNA and protein expression of resistin and chemerin (and ChemR23) and carotid plaque instability in humans, and whether sex differences exist in the relationship between these adipokines and plaque instability. Human carotid plaques were processed for immunohistochemical/mRNA analysis of resistin, chemerin, and ChemR23. Plaque instability was assessed by gold-standard histological classifications. A semi-quantitative scoring system was used to determine the intensity of adipokine expression on macrophages/foam cells, as well as the percentage of inflammatory cells stained positive. Plaque adipokine protein expression was also digitally quantified and mRNA expression was assessed by qRT-PCR. Resistin and chemerin mRNA expression was 80% and 32% lower, respectively, in unstable versus stable plaques (P<0.05), while no difference in ChemR23 mRNA expression was observed. In contrast, greater resistin staining intensity and percentage of cells stained positive were detected in unstable versus stable plaques (P<0.01). Similarly, chemerin and ChemR23 staining intensity and percentage of cells stained were positively associated with plaque instability (P<0.05). No strong sex-specific relationship was observed between adipokines and plaque instability. This study examined the relationship between resistin, chemerin, and ChemR23, and carotid plaque instability, with a specific analysis at the plaque level. We reported a positive association between plaque instability and protein levels of resistin, chemerin, and ChemR23 but a negative association with resistin and chemerin mRNA expression. This suggests these adipokines exert proinflammatory roles in the process of carotid atherosclerosis and may be regulated via a negative feedback regulatory mechanism.

Search for Reliable Circulating Biomarkers to Predict Carotid Plaque Vulnerability.

Atherosclerosis is responsible for 20% of ischemic strokes, and the plaques from the internal carotid artery the most frequently involved. Lipoproteins play a key role in carotid atherosclerosis since lipid accumulation contributes to plaque progression and chronic inflammation, both factors leading to plaque vulnerability. Carotid revascularization to prevent future vascular events is reasonable in some patients with high-grade carotid stenosis. However, the degree of stenosis alone is not sufficient to decide upon the best clinical management in some situations. In this context, it is essential to further characterize plaque vulnerability, according to specific characteristics (lipid-rich core, fibrous cap thinning, intraplaque hemorrhage). Although these features can be partly detected by imaging techniques, identifying carotid plaque vulnerability is still challenging. Therefore, the study of circulating biomarkers could provide adjunctive criteria to predict the risk of atherothrombotic stroke. In this regard, several molecules have been found altered, but reliable biomarkers have not been clearly established yet. The current review discusses the concept of vulnerable carotid plaque, and collects existing information about putative circulating biomarkers, being particularly focused on lipid-related and inflammatory molecules.

Visceral Fat Thickness Is Associated With Carotid Atherosclerosis in Peritoneal Dialysis Patients

Visceral fat has been known to associate with atherosclerosis, inflammation, and insulin resistance. However, the influence of visceral fat on cardiovascular disease (CVD) in peritoneal dialysis (PD) patients has never been elucidated. We investigated whether visceral fat thickness (VFT) has a predictive role in carotid atherosclerosis determined by carotid intima-media thickness (cIMT) in PD patients. A cross-sectional study was undertaken in 88 prevalent PD patients. BMI and waist circumference (WC) were measured as anthropometric indexes of obesity. VFT and subcutaneous fat thickness (SFT) were determined by sonographic measurement of abdominal fat. Carotid atherosclerosis was defined as increased cIMT (>1.0 mm) or presence of plaque. Thirty-two (36.3%) patients had carotid atherosclerosis. Patients with carotid atherosclerosis showed significantly higher VFT, BMI, and WC. In univariate logistic analysis, BMI, WC, and VFT except SFT were significant risk factors of carotid atherosclerosis. However, multivariate analysis revealed VFT was an independent factor associated with carotid atherosclerosis after adjusting for demographic, biochemical parameters, and anthropometric indexes (per 1 mm increase, odds ratio (OR) = 2.294, 95% confidence interval: 1.048-5.021, P = 0.038). When the patients were divided into three groups according to VFT, log high sensitivity C-reactive protein (hs-CRP), and homeostasis model assessment-insulin resistance (HOMA(IR)) were both higher in the third tertile compared to other tertiles. In conclusion, VFT, not SFT, is independently associated with carotid atherosclerosis in PD patients. Therefore sonographic measurement of VFT could be useful to stratify the risk of cardiovascular disease in PD patients.

Impact of Obesity in Intima Media Thickness of Carotid Arteries

To explore differences in intima media thickness (IMT) of the carotid arteries induced by differences in BMI. Data from 3173 consecutive subjects, who were referred to our Hypertension Center from 1998 to 2004, were reviewed. Criteria for patients to be considered for further analysis included no past or concurrent antihypertensive medication, no concurrent medication with the potential to raise blood pressure (BP) (e.g., prednisone), and no clinical signs or laboratory evidence of secondary causes of hypertension. Our population was divided into four groups according to NIH criteria for obesity: underweight, normal weight, overweight, and obese. BMI, mean IMT of internal carotid arteries, and 24-hour BP values were available for all subjects. Five hundred thirty six subjects of the four groups, matched for age, gender, and mean 24-hour BP values, were included in the analysis. Mean IMT of internal carotid arteries was increased with increasing BMI. Mean IMT was significantly higher in obese subjects compared with normal-weight (p < 0.01) and underweight (p < 0.001) subjects. Mean IMT was significantly higher in overweight subjects compared with normal-weight ones (p < 0.05). Furthermore, multivariate regression analysis in obese subjects revealed that fasting serum glucose was independently associated with IMT. Obesity may be an important factor for carotid atherosclerosis, and at least some of the effects of obesity are independent of the BP levels. Fasting serum glucose levels in obese subjects may play an important role in carotid atherosclerosis.

Lack of association between polymorphisms of the toll-like receptor 4 gene and cerebral ischemia.

Toll-like receptor-4 (TLR4), an important mediator of the innate immune response, is expressed in atherosclerotic lesions. The common single nucleotide exchange (Asp299Gly) of the TLR4 gene has been previously reported to impair TLR4 function and to be associated with a decreased risk of carotid atherosclerosis. Therefore, we aimed to detect the potential impact of TLR4 genotypes on the risk of cerebral ischemia. We studied the prevalence of two common polymorphisms of the TLR4 gene (Asp299Gly and Thr399Ile) in 3 independent study populations: (1.) in a cross-sectional study including 769 patients either with type 1 or type 2 diabetes mellitus, of whom 56 (7.2%) had a history of cerebral ischemia (study 1), (2.) a case-control study (study 2) including 128 consecutive patients with cerebral ischemia, mean age 60 +/- 10.9 years and 139 control subjects, and (3.) a case-control study (study 3) including 171 young adults aged < 50 years with cerebral ischemia and 204 control individuals. In all subjects, Asp299Gly and Thr399Ile were detected by restriction length analysis. The prevalence of the TLR4 genotypes was essentially the same between patients with cerebral ischemia and control subjects in all 3 study populations. Furthermore, there was also no association with the subgroup of atherosclerotic stroke in both case-control studies populations. Although TLR4 polymorphisms are associated with a decreased risk of carotid atherosclerotic lesions, our findings indicate that they do not influence the prevalence of cerebral ischemia. This implies that the Asp299Gly TLR4-allele might have a protective role in carotid atherosclerosis, but not in cerebral ischemia.

C-reactive protein, lipoprotein(a), homocysteine, and male sex contribute to carotid atherosclerosis in peritoneal dialysis patients

Background:In patients with end-stage renal disease, the morbidity and mortality of cardiovascular disease are substantially greater than in the general population. Advancement in understanding the pathogenesis of atherosclerotic vascular disease suggests a central role of inflammation in atherogenesis. However, clinical data evaluating the role of inflammation in atherogenesis are sparse in peritoneal dialysis (PD) patients. Methods:We measured serum C-reactive protein (CRP), intact parathyroid hormone, lipoprotein(a) [Lp(a)], interleukin-1 receptor antagonist (IL-1Ra), tumor necrosis factor soluble receptor (TNF-sR), fibrinogen, and plasma homocysteine (Hcy), as well as intima-media thickness (IMT) and number of atherosclerotic plaques (plaque score [PS]) in the carotid arteries by means of carotid B-mode ultrasonography in 59 PD patients (35 men, 24 women; mean age, 52.4 years; average dialysis period, 36 months). All patients had chronic glomerulonephritis. Results:Sixty-eight percent of PD patients had at least 1 plaque. Serum CRP level was greater than the upper limit of the normal range in 52.5% of patients. Compared with PD patients with normal CRP levels, concentrations of such proinflammatory cytokines as IL-1Ra and TNF-sR, Lp(a), and Hcy were increased in PD patients with elevated CRP levels. However, no differences in plasma fibrinogen and intact parathyroid hormone levels were found between PD patients with increased and normal CRP levels. In a multiple regression model, age, male sex, CRP level, and Lp(a) level were independent predictors of IMT. Similarly, male sex, CRP level, Lp(a) level, and Hcy level were independent correlates of PS. Conclusion:This study suggests that Lp(a) and Hcy levels and male sex, and especially CRP level, have an important role in carotid atherosclerosis in PD patients.

The role of carotid atherosclerosis in the distinction between ischaemic and non-ischaemic cardiomyopathy.

Sometimes ischaemic cardiomyopathy is a result of severe coronary artery disease of an occult course, without typical symptoms or evidence of myocardial infarction. This form of presentation is usually indistinguishable from non-ischaemic dilated cardiomyopathy. Carotid bifurcation atherosclerosis and coronary artery disease have been shown to be strongly associated. We prospectively examined the value of extracranial carotid atherosclerosis in the distinction between ischaemic and non-ischaemic aetiology in patients with clinically unexplained cardiomyopathy. Seventy-eight patients with undetermined dilatation and diffuse impairment of the left ventricular contraction were studied within 28 months. They underwent carotid scan and coronary arteriography. Carotid atherosclerosis was found to be very common in ischaemic and rare in non-ischaemic cardiomyopathy. The presence of at least one abnormal carotid finding (intima-media thickness >1 mm, plaques, severe carotid stenosis) was 96% sensitive and 89% specific for ischaemic cardiomyopathy. Carotid scanning may be a useful screening and decision making tool in patients with cardiomyopathy of indecisive cause. Patients with carotid atherosclerosis are likely to suffer from severe coronary artery disease. Coronary angiography and subsequent myocardial viability studies, when indicated, could be considered early during their evaluation. In contrast, a negative carotid scan predicts non-ischaemic cardiomyopathy.

Relationship of angiotensin-converting enzyme gene polymorphism to carotid wall thickness in middle-aged men.

The insertion/deletion (I/D) polymorphism of the human angiotensin-converting enzyme (ACE) gene is a major determinant of circulating ACE levels. The D allele has been suggested to be a potent risk factor for coronary artery disease; however, the effect of the ACE gene on carotid atherosclerosis remains controversial. We therefore studied the relationship between the ACE gene I/D polymorphism and carotid artery intima-media thickness (IMT). A random sample of 300 men aged 50-59 years living in southern Finland were selected, and 233 agreed to participate (74%). Data were collected in 219 subjects. Quantitative B-mode ultrasonography was used to measure the maximum near and far wall IMT of right and left common, bifurcation, and internal carotid artery. The mean maximum IMT (overall mean) was calculated as the mean of 12 maximum IMTs at 12 standard sites. Patients with an IMT higher than 1.7 mm in at least one of 12 standard sites were assumed to have carotid atherosclerosis. The I/D polymorphism was determined by polymerase chain reaction. Overestimation of the frequency of the DD genotype was eliminated by insertion-specific primer and the inclusion of 5% dimethylsulfoxide. No significant differences were found in carotid wall thickness between the three genotypes; the overall mean IMT were 1.18 +/- 0.30, 1.22 +/- 0.24, and 1.08 +/- 0.40 mm in genotypes of II, ID, and DD, respectively. Similarly, the ACE genotypes and allele frequencies did not differ significantly between the subjects with and those without carotid atherosclerosis. There was no association in the subgroups among only nonsmoking subjects or subjects without chronic medication. The present data indicate that the I/D polymorphism of the ACE gene is not related to carotid IMT and is unlikely to play a major role in carotid atherosclerosis.