Atheroprotective Krüppel-like factor 4 is downregulated in monocyte subsets of patients with coronary artery disease

The Association Between Monocyte Subsets and Cardiometabolic Disorders/Cardiovascular Disease: A Systematic Review and Meta-Analysis

Background: Monocyte subsets in humans, i.e., classical (CM), intermediate (IM), and non-classical monocytes (NCM), are thought to differentially contribute to the pathogenesis of atherosclerosis, the leading cause of cardiovascular disease (CVD). However, the association between monocyte subsets and cardiometabolic disorders and CVD is not well-understood. Thus, the aim of the current systematic review and meta-analysis was to evaluate recent findings from clinical studies that examined the association between the distribution of monocyte subsets in subjects with cardiometabolic disorders and CVD compared to healthy controls.

Methods: Articles were systematically searched in CINAHL, PubMed and Cochrane Library. Articles were independently screened and selected by two reviewers. Studies that reported the percentage of each monocyte subset were included in the systematic review and meta-analysis. For the meta-analysis, a random-effects model was used to generate pooled standardized mean differences (SMD) between subjects with cardiometabolic disorders and healthy controls.

Results: A total of 1,693 articles were screened and 27 studies were selected for qualitative analyses. Among them, six studies were included in the meta-analysis. In total, sample size ranged from 22 to 135 and mean or median age from 22 to 70 years old. We found studies that reported higher percentage and number of IM and/or NCM in subjects with cardiometabolic disorders (9 out of 13 studies) and in subjects with CVD (11 out of 15 studies) compared to healthy controls. In the meta-analysis, the percentage of CM was lower [SMD = −1.21; 95% CI (−1.92, −0.50); P = 0.0009; I² = 91%] and the percentage of IM [SMD = 0.56; 95% CI (0.23, 0.88); P = 0.0008; I² = 65%] and NCM [SMD = 1.39; 95% CI (0.59, 2.19); P = 0.0007; I² = 93%] were higher in subjects with cardiometabolic disorders compared to healthy controls.

Conclusions: Individuals with cardiometabolic disorders and CVD may have a higher percentage of IM and NCM than healthy controls. Future studies are needed to evaluate the cause and biological significance of this potential altered distribution of monocyte subsets.

Epidemiology and pathogenesis of diffuse obstructive coronary artery disease: the role of arterial stiffness, shear stress, monocyte subsets and circulating microparticles

Despite falling age-adjusted mortality rates coronary artery disease (CAD) remains the leading cause of death worldwide. Advanced diffuse CAD is becoming an important entity of modern cardiology as more patients with historical revascularisation no longer have suitable anatomy for additional procedures. Advances in the treatment of diffuse obstructive CAD are hampered by a poor understanding of its development. Although the likelihood of developing clinically significant (obstructive) CAD is linked to traditional risk factors, the morphology of obstructive CAD among individuals is highly variable - some patients have diffuse stenotic disease, while others have a focal stenosis. This is challenging to explain in mechanistic terms as vascular endothelium is equally exposed to injury stimulants. Patients with diffuse disease are at high risk of adverse outcomes, particularly if unsuitable for revascularisation. We searched multiple electronic databases (MEDLINE, EMBASE and the Cochrane Database) and reviewed the epidemiology, pathogenesis and prognosis relating to advanced diffuse CAD with particular focus on the role of endothelial shear stress, large artery stiffness, monocyte subsets and circulating microparticles. Key messages Although traditional CAD risk factors correlate strongly with disease severity, significant individual variation in disease morphology exists. Advanced, diffuse CAD is difficult to treat effectively and can significantly impair quality of life and increases mortality. The pathophysiology associated with the progression of CAD is the result of complex maladaptive interaction between the endothelium, cells of the immune system and patterns of blood flow.

Regulation of an inflammatory disease: Krüppel-like factors and atherosclerosis

This invited review summarizes work presented in the Russell Ross lecture delivered at the 2012 proceedings of the American Heart Association. We begin with a brief overview of the structural, cellular, and molecular biology of Krüppel-like factors. We then focus on discoveries during the past decade, implicating Krüppel-like factors as key determinants of vascular cell function in atherosclerotic vascular disease.