Microvascular inflammation in atherosclerosis

[Retinal vascular network: Changes with aging and systemic vascular disease (cardiac and cerebral)]

For over 10 years, the description of the retinal microvascular network has benefited from the development of new imaging techniques. Automated retinal image analysis software, as well as OCT angiography (OCT-A), are able to highlight subtle, early changes in the retinal vascular network thanks to a large amount of microvascular quantitative data. The challenge of current research is to demonstrate the association between these microvascular changes, the systemic vascular aging process, and cerebrovascular and cardiovascular disease. Indeed, a pathophysiological continuum exists between retinal microvascular changes and systemic vascular diseases. In the Montrachet study, we found that a suboptimal retinal vascular network, as identified by the Singapore I Vessel Assessment (SIVA) software, was significantly associated with treated diabetes and an increased risk of cardiovascular mortality. In addition, we supplemented our research on the retinal vascular network with the use of OCT-A. In the EYE-MI study, we showed the potential role of quantitative characterization of the retinal microvascular network by OCT-A in order to assess the cardiovascular risk profile of patients with a history of myocardial infarction. A high AHA (American Heart Association) risk score was associated with low retinal vascular density independently of hemodynamic changes. Thus, a better understanding of the association between the retinal microvasculature and macrovascular disease might make its use conceivable for early identification of at-risk patients and to suggest a personalized program of preventative care. The retinal vascular network could therefore represent an indicator of systemic vascular disease as well as an interesting predictive biomarker for vascular events.

Role of Blood Stasis Syndrome of Kampo Medicine in the Early Pathogenic Stage of Atherosclerosis: A Retrospective Cross-Sectional Study

In Kampo medicine, blood stasis (BS) syndrome is strongly associated with microangiopathy and can lead to atherosclerosis. Vascular endothelial dysfunction (VED), evaluated through flow-mediated dilation (FMD), plays an important role in the early stages of atherosclerosis. However, the association of BS syndrome with VED, as determined using FMD, has not been reported. This study investigated the association between BS syndrome and VED using FMD. Forty-one patients with normal glucose tolerance or impaired glucose tolerance (IGT) and without macrovascular complications were evaluated using FMD from May 2017 to August 2017. Based on the BS score, the patients were divided into the non-BS (n = 19) and BS syndrome (n = 22) groups. Physical and background characteristics, physiological function test results, and laboratory data were compared. Univariate analysis revealed that FMD and a history of dyslipidemia/IGT were significantly different between the two groups (p < 0.05). Multiple logistic regression analysis showed that BS syndrome was significantly associated with FMD (odds ratio: 6.26; p=0.03) after adjusting for the history of dyslipidemia/IGT. The receiver operating characteristic curve showed that the area under the curve for BS syndrome (0.74; p < 0.001) and history of IGT (p < 0.007) provided good diagnostic accuracy for FMD. The area under the curve for “BS syndrome + IGT” showed very good accuracy (0.80; p < 0.0001) and was higher than that for BS syndrome or IGT alone. In conclusion, the results of this study suggest that the BS score in Kampo medicine could be a useful tool for detecting the early pathogenic stages of atherosclerosis.

Angiogenic CD34 Stem Cell Therapy in Coronary Microvascular Repair-A Systematic Review

Ischemia with non-obstructive coronary arteries (INOCA) is an increasingly recognized disease, with a prevalence of 3 to 4 million individuals, and is associated with a higher risk of morbidity, mortality, and a worse quality of life. Persistent angina in many patients with INOCA is due to coronary microvascular dysfunction (CMD), which can be difficult to diagnose and treat. A coronary flow reserve <2.5 is used to diagnose endothelial-independent CMD. Antianginal treatments are often ineffective in endothelial-independent CMD and thus novel treatment modalities are currently being studied for safety and efficacy. CD34+ cell therapy is a promising treatment option for these patients, as it has been shown to promote vascular repair and enhance angiogenesis in the microvasculature. The resulting restoration of the microcirculation improves myocardial tissue perfusion, resulting in the recovery of coronary microvascular function, as evidenced by an improvement in coronary flow reserve. A pilot study in INOCA patients with endothelial-independent CMD and persistent angina, treated with autologous intracoronary CD34+ stem cells, demonstrated a significant improvement in coronary flow reserve, angina frequency, Canadian Cardiovascular Society class, and quality of life (ESCaPE-CMD, NCT03508609). This work is being further evaluated in the ongoing FREEDOM (NCT04614467) placebo-controlled trial.

Role of Vascular Smooth Muscle Cell Plasticity and Interactions in Vessel Wall Inflammation

The pathobiology of atherosclerotic disease requires further elucidation to discover new approaches to address its high morbidity and mortality. To date, over 17 million cardiovascular-related deaths have been reported annually, despite a multitude of surgical and nonsurgical interventions and advances in medical therapy. Existing strategies to prevent disease progression mainly focus on management of risk factors, such as hypercholesterolemia. Even with optimum current medical therapy, recurrent cardiovascular events are not uncommon in patients with atherosclerosis, and their incidence can reach 10–15% per year. Although treatments targeting inflammation are under investigation and continue to evolve, clinical breakthroughs are possible only if we deepen our understanding of vessel wall pathobiology. Vascular smooth muscle cells (VSMCs) are one of the most abundant cells in vessel walls and have emerged as key players in disease progression. New technologies, including in situ hybridization proximity ligation assays, in vivo cell fate tracing with the CreER^T2-loxP system and single-cell sequencing technology with spatial resolution, broaden our understanding of the complex biology of these intriguing cells. Our knowledge of contractile and synthetic VSMC phenotype switching has expanded to include macrophage-like and even osteoblast-like VSMC phenotypes. An increasing body of data suggests that VSMCs have remarkable plasticity and play a key role in cell-to-cell crosstalk with endothelial cells and immune cells during the complex process of inflammation. These are cells that sense, interact with and influence the behavior of other cellular components of the vessel wall. It is now more obvious that VSMC plasticity and the ability to perform nonprofessional phagocytic functions are key phenomena maintaining the inflammatory state and senescent condition and actively interacting with different immune competent cells.

Correlation of neutrophil/lymphocyte and platelet/lymphocyte ratios with the severity of idiopathic carpal tunnel syndrome

BACKGROUND

The aim of the present study was to investigate the correlation of the neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio with the severity of idiopathic carpal tunnel syndrome (CTS).

METHODS

A total of 407 patients with idiopathic CTS (neurophysiologically 150 mild, 144 moderate, and 113 severe) and 206 subjects without CTS were included (control group).

RESULTS

There was a positive correlation between the severity of CTS and NLR (r = 0.224; P < 0.001), age (r = 0.333; P < 0.001), and body mass index (r = 0.251; P < 0.001). A 1-unit increase in NLR level was associated with an approximately 1.7-fold higher incidence of CTS (P = 0.002; odds ratio = 1.668; 95% confidence interval = 1.199-2.319).

CONCLUSIONS

Our results suggest that neurophysiologically more severe CTS is associated with higher NLR levels. The role of systemic inflammation in CTS should be investigated in further studies.

Redox Regulation of the Microcirculation

The microcirculation maintains tissue homeostasis through local regulation of blood flow and oxygen delivery. Perturbations in microvascular function are characteristic of several diseases and may be early indicators of pathological changes in the cardiovascular system and in parenchymal tissue function. These changes are often mediated by various reactive oxygen species and linked to disruptions in pathways such as vasodilation or angiogenesis. This overview compiles recent advances relating to redox regulation of the microcirculation by adopting both cellular and functional perspectives. Findings from a variety of vascular beds and models are integrated to describe common effects of different reactive species on microvascular function. Gaps in understanding and areas for further research are outlined. © 2020 American Physiological Society. Compr Physiol 10:229-260, 2020.

Microvascular endothelial dysfunction in rheumatoid arthritis

The systemic autoimmune disease rheumatoid arthritis (RA) is characterized by increased cardiovascular mortality and morbidity and is an independent cardiovascular risk factor. Cardiovascular diseases (CVDs) result from accelerated atherogenesis, which is a consequence of endothelial dysfunction in the early stages of the disease. Endothelial dysfunction is a functional and reversible alteration of endothelial cells and leads to a shift in the properties of the endothelium towards reduced vasodilation, a pro-inflammatory state, and proliferative and prothrombotic properties. In RA, endothelial dysfunction can occur in the large vessels (such as the conduit arteries) and in the small vessels of the microvasculature, which supply oxygen and nutrients to the tissue and control inflammation, repair and fluid exchange with the surrounding tissues. Growing evidence suggests that microvascular endothelial dysfunction contributes to CVD development, as it precedes and predicts the development of conduit artery atherosclerosis and associated risk factors. As such, numerous studies have investigated microvascular endothelial dysfunction in RA, including its link with disease activity, disease duration and inflammation, the effect of treatments on endothelial function, and possible circulating biomarkers of microvascular endothelial dysfunction. Such findings could have important implications in the cardiovascular risk management of patients with RA.

Platelet-Specific Deletion of Cyclooxygenase-1 Ameliorates Dextran Sulfate Sodium-Induced Colitis in Mice

Inflammatory bowel disease (IBD) is associated with an increased risk for thromboembolism, platelet activation, and abnormalities in platelet number and size. In colitis, platelets can extravasate into the colonic interstitium. We generated a mouse with a specific deletion of cyclooxygenase (COX)-1 in megakaryocytes/platelets [(COX-1 conditional knockout (cKO)] to clarify the role of platelet activation in the development of inflammation and fibrosis in dextran sodium sulfate (DSS)-induced colitis. The disease activity index was assessed, and colonic specimens were evaluated for histologic features of epithelial barrier damage, inflammation, and fibrosis. Cocultures of platelets and myofibroblasts were performed. We found that the specific deletion of COX-1 in platelets, which recapitulated the human pharmacodynamics of low-dose aspirin, that is, suppression of platelet thromboxane (TX)A₂ production associated with substantial sparing of the systemic production of prostacyclin, resulted in milder symptoms of colitis, in the acute phase, and almost complete recovery from the disease after DSS withdrawal. Reduced colonic accumulation of macrophages and myofibroblasts and collagen deposition was found. Platelet-derived TXA₂ enhanced the ability of myofibroblasts to proliferate and migrate in vitro, and these effects were prevented by platelet COX-1 inhibition or antagonism of the TXA₂ receptor. Our findings allow a significant advance in the knowledge of the role of platelet-derived TXA₂ in the development of colitis and fibrosis in response to intestinal damage and provide the rationale to investigate the potential efficacy of the antiplatelet agent low-dose aspirin in limiting the inflammatory response and fibrosis associated with IBD. SIGNIFICANCE STATEMENT: Inflammatory bowel disease (IBD) is characterized by the development of a chronic inflammatory response, which can lead to intestinal fibrosis for which currently there is no medical treatment. Through the generation of a mouse with specific deletion of cyclooxygenase-1 in megakaryocytes/platelets, which recapitulates the human pharmacodynamics of low-dose aspirin, we demonstrate the important role of platelet-derived thromboxane A₂ in the development of experimental colitis and fibrosis, thus providing the rationale to investigate the potential efficacy of low-dose aspirin in limiting the inflammation and tissue damage associated with IBD.

Vasculoprotective Role of Olive Oil Compounds via Modulation of Oxidative Stress in Atherosclerosis

Existing evidence supports the significant role of oxidative stress in the endothelial injury, and there is a direct link between increased oxidative stress, and the development of endothelial dysfunction. Endothelial dysfunction precedes the development of atherosclerosis and subsequent cardiovascular disease (CVD). The overproduction of reactive oxygen species facilitates the processes, such as oxidative modification of low-density lipoproteins and phospholipids, reduction in the NOS-derived nitric oxide, and the functional disruption of high-density lipids that are profoundly involved in atherogenesis, inflammation, and thrombus formation in vascular cells. Thus, under oxidative stress conditions, endothelial dysfunction was found to be associated with the following endothelial alterations: reduced nitric oxide bioavailability, increased anticoagulant properties, increased platelet aggregation, increased expression of adhesion molecules, chemokines, and cytokines. In this review, we summarized the evidence indicating that endothelial damage triggered by oxidation can be diminished or reversed by the compounds of olive oil, a readily available antioxidant food source. Olive oil bioactive compounds exhibited a potent capability to attenuate oxidative stress and improve endothelial function through their anti-inflammatory, anti-oxidant, and anti-thrombotic properties, therefore reducing the risk and progression of atherosclerosis. Also, their molecular mechanisms of action were explored to establish the potential preventive and/or therapeutic alternatives to the pharmacological remedies available.

Association of Serum SorLA with Intimal Hyperplasia after Carotid Endarterectomy Operation: A Retrospective Analysis

BACKGROUND

To study the relevance between serum sorting protein-related receptor containing the low-density lipoprotein receptor class A (SorLA) and intimal hyperplasia (IH) after carotid endarterectomy (CEA) operation.

METHODS

Seventy-nine carotid artery stenosis patients receiving CEA operation from September 2013 to March 2015 were included. Serum SorLA level was detected by enzyme linked immunosorbent assay method preoperatively. All the 79 patients received regular follow-up to diagnose the IH of target lesions, postoperatively. Based on the follow-up data, the patients were divided into IH group (n = 10) and non-IH group (n = 69). Serum SorLA levels were analyzed using t-test. Receiver-operating characteristic curve was applied to determine the value of serum SorLA to predict the occurrence of IH after CEA operation.

RESULTS

Patients in severe IH group had a higher level of serum SorLA than patients in non-IH group (1.648 ± 0.246 ng/mL vs. 1.278 ± 0.281 ng/mL, P < 0.001). When 1.44 ng/mL was designated as the cutoff value of serum SorLA, the predicting value had a sensitivity of 90% and a specificity of 73.5%.

CONCLUSIONS

High serum SorLA level is related to IH after CEA operation. A serum SorLA level of 1.44 ng/mL can be used as a predicting index of postoperative IH.

Why names matter for women: MINOCA/INOCA (myocardial infarction/ischemia and no obstructive coronary artery disease)

The syndromes of myocardial infarction/myocardial ischemia with No Obstructive Coronary Artery Disease (MINOCA/INOCA) are increasingly evident. A majority of these patients have coronary microvascular dysfunction. These patients have elevated risk for a cardiovascular event (including acute coronary syndrome, myocardial infarction, stroke, and repeated cardiovascular procedures) and appear to be at higher risk for development of heart failure with preserved ejection fraction. Terminology such as coronary artery disease or coronary heart disease is often synonymous with obstructive atherosclerosis in the clinician's mind, leaving one at a loss to recognize or explain the phenomenon of MINOCA and INOCA with elevated risk. We review the available literature regarding stable and unstable ischemic heart disease that suggests that use of the ischemic heart disease (IHD) terminology matters for women, and should facilitate recognition of risk to provide potential treatment targets and optimized health.

Ischemia and No Obstructive Coronary Artery Disease (INOCA): Developing Evidence-Based Therapies and Research Agenda for the Next Decade

The Cardiovascular Disease in Women Committee of the American College of Cardiology, in conjunction with interested parties (from the National Heart, Lung, and Blood Institute, American Heart Association, and European Society of Cardiology), convened a working group to develop a consensus on the syndrome of myocardial ischemia with no obstructive coronary arteries. In general, these patients have elevated risk for a cardiovascular event (including acute coronary syndrome, heart failure hospitalization, stroke, and repeat cardiovascular procedures) compared with reference subjects and appear to be at higher risk for development of heart failure with preserved ejection fraction. A subgroup of these patients also has coronary microvascular dysfunction and evidence of inflammation. This document provides a summary of findings and recommendations for the development of an integrated approach for identifying and managing patients with ischemia with no obstructive coronary arteries and outlines knowledge gaps in the area. Working group members critically reviewed available literature and current practices for risk assessment and state-of-the-science techniques in multiple areas, with a focus on next steps needed to develop evidence-based therapies. This report presents highlights of this working group review and a summary of suggested research directions to advance this field in the next decade.

Association of Nitric Oxide Levels and Endothelial Nitric Oxide Synthase G894T Polymorphism with Coronary Artery Disease in the Iranian Population

Purpose:

The endothelial nitric oxide synthase (eNOS) G894T polymorphism has been reported to cause endothelial dysfunction and may have a role in the development of coronary artery disease (CAD). The aim of the present study was to investigate the association of eNOS G894T genetic polymorphism and plasma levels of nitric oxide (NO) with CAD risk in an Iranian population.

Materials and Methods:

We studied 200 patients with angiographically documented CAD and 100 matched controls. Analysis of G894T genetic polymorphism of eNOS was performed by polymerase chain reaction-restriction fragment length polymorphism method. Plasma levels of NO were determined using Griess method. Biochemical analysis was conducted by routine colorimetric methods.

Results:

Plasma levels of NO were significantly lower in CAD patients than control subjects (41.60±12.70 vs. 55.48±16.57, P=0.001). Also, the mean plasma levels of NO were significantly lower in T allele carriers of eNOS G894T polymorphism than G allele carriers (P<0.001). The genotype distribution and minor T allele frequency of eNOS G894T polymorphism significantly differed between CAD patients and control subjects (P<0.05). However, no significant association was found between the eNOS G894T polymorphism and the severity of CAD (number of diseased vessel) or the lipid profile of CAD patients (P>0.05).

Conclusion:

Reduced plasma level of NO is associated with increased risk of CAD in our population. Moreover, eNOS G894T polymorphism is a significant risk factor for CAD development via reducing the plasma levels of NO. However, eNOS G894T polymorphism is not a contributing factor for the severity of CAD.

Posttranscriptional and transcriptional regulation of endothelial nitric-oxide synthase during hypoxia: the role of microRNAs

Understanding the cellular pathways that regulate endothelial nitric oxide (eNOS, NOS3) expression and consequently nitric oxide (NO) bioavailability during hypoxia is a necessary aspect in the development of novel treatments for cardiovascular disorders. eNOS expression and eNOS-dependent NO cellular signaling during hypoxia promote an equilibrium of transcriptional and posttranscriptional molecular mechanisms that belong to both proapoptotic and survival pathways. Furthermore, NO bioavailability results not only from eNOS levels, but also relies on the presence of eNOS substrate and cofactors, the phosphorylation status of eNOS, and the presence of reactive oxygen species (ROS) that can inactivate eNOS. Since both NOS3 levels and these signaling pathways can also be a subject of posttranscriptional modulation by microRNAs (miRNAs), this class of short noncoding RNAs contribute another level of regulation for NO bioavailability. As miRNA antagomirs or specific target protectors could be used in therapeutic approaches to regulate NO levels, either by changing NOS3 mRNA stability or through factors governing eNOS activity, it is critical to understand their role in governing eNOS activity during hypoxa. In contrast to a large number of miRNAs reported to the change eNOS expression during hypoxia, only a few miRNAs modulate eNOS activity. Furthermore, impaired miRNA biogenesis leads to NOS3 mRNA stabilization under hypoxia. Here we discuss the recent studies that define miRNAs’ role in maintaining endothelial NO bioavailability emphasizing those miRNAs that directly modulate NOS3 expression or eNOS activity.

Do circulating blood cell types correlate with modifiable risk factors and outcomes in patients with acute coronary syndrome (ACS)?

AIMS

Atherosclerosis is an inflammatory process with different cardiovascular risk factors (CVRFs) contributing to its pathogenesis. We aimed to evaluate the specific relationship between circulating blood leukocytes, troponin I and CVRFs.

METHODS

We prospectively enrolled 959 patients with evidence of acute coronary syndrome either in form of unstable angina or STEMI or NSTEMI. Details demographic characteristics, CVRF and biochemical parameters such as total white blood cells (WBC), neutrophil, lymphocytes, platelet, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and troponin I were collected.

RESULTS

The results indicated that patients having either hypertension, diabetes or smoking habit had significantly higher levels of total WBC (p=0.013), neutrophil (p=0.029), NLR (p=0.029) and PLR (p=0.009). The level of troponin I was unaffected by these risk factors. Significant association of hypertension was found with total WBC (p=0.0392), lymphocytes (p=0.0384) and PLR (p=0.0027), whereas in diabetes and females all other leukocyte subtypes were significantly altered except for platelet and troponin I. Smokers had higher level of total WBC count (p=0.0033) and PLR (p=0.0464). No relationship between CVRFs and leukocytes was observed in males. The age independent effect was observed with PLR, whereas association with total WBC, lymphocytes, NLR, platelet was specific in older population. In younger patients NLR (p=0.0453) is more likely to be elevated. Mortality was significantly associated with changes in the leukocytes but not with the CVRF presence.

CONCLUSION

We demonstrate that the neutrophils, lymphocytes and total WBC along with its ratios predict mortality and are more likely to be elevated in presence of CVRFs.