Neutrophil extracellular trap burden correlates with the stenosis of coronary atherosclerosis

NETosis in myocardial ischemia-reperfusion injury: From mechanisms to therapies (Review)

The present review describes the mechanisms of NETosis and its role in myocardial ischemia-reperfusion injury (MIRI), focusing on the release of neutrophil extracellular traps (NETs) by activated neutrophils. NETs, composed of depolymerized chromatin and granule proteins, are crucial for pathogen entrapment, infection control and immune regulation. However, NET formation, linked to neutrophil death (NETosis), exacerbates MIRI by promoting inflammation and tissue damage. To address therapeutic strategies for NETosis in MIRI, several potential clinically significant approaches were explored, including peptidylarginine deaminase 4 inhibition, DNase therapy, antioxidants, inflammation modulation, and antithrombotic treatments, which not only provide novel diagnostic biomarkers and therapeutic targets in MIRI, but are also expected to improve patient prognosis and advance the development of personalised medicine.

Novel Circulating Biomarkers in Aortic Valve Stenosis

The underlying pathophysiology of aortic stenosis and factors affecting its clinical progression remain poorly understood. Apart from B-type natriuretic peptide (BNP), novel and emerging biomarkers have been described in association with aortic stenosis, emphasising the potential for these biomarkers to illuminate on yet unknown mechanisms of its pathogenesis. In this review, we aimed to summarise what is known about aortic stenosis biomarkers, highlight the emerging ones, and provide a roadmap for translating these insights into clinical applications. Among the biomarkers studied, lipoprotein(a) [Lp(a)] has emerged as the most promising for risk stratification. Elevated Lp(a) levels are often associated with more rapid aortic stenosis progression. This detrimental effect is attributed to its role in promoting valve calcification. While other emerging biomarkers such as matrix metalloproteinases, monocytes, and metabolites show promises, their specific roles in aortic stenosis pathophysiology remain less clear. This may be due to their relatively recent discovery. Ongoing research aims to elucidate their mechanisms of action.

Neutrophil extracellular traps in homeostasis and disease

Neutrophil extracellular traps (NETs), crucial in immune defense mechanisms, are renowned for their propensity to expel decondensed chromatin embedded with inflammatory proteins. Our comprehension of NETs in pathogen clearance, immune regulation and disease pathogenesis, has grown significantly in recent years. NETs are not only pivotal in the context of infections but also exhibit significant involvement in sterile inflammation. Evidence suggests that excessive accumulation of NETs can result in vessel occlusion, tissue damage, and prolonged inflammatory responses, thereby contributing to the progression and exacerbation of various pathological states. Nevertheless, NETs exhibit dual functionalities in certain pathological contexts. While NETs may act as autoantigens, aggregated NET complexes can function as inflammatory mediators by degrading proinflammatory cytokines and chemokines. The delineation of molecules and signaling pathways governing NET formation aids in refining our appreciation of NETs' role in immune homeostasis, inflammation, autoimmune diseases, metabolic dysregulation, and cancer. In this comprehensive review, we delve into the multifaceted roles of NETs in both homeostasis and disease, whilst discussing their potential as therapeutic targets. Our aim is to enhance the understanding of the intricate functions of NETs across the spectrum from physiology to pathology.

Myeloid Cells in Myocardial Ischemic Injury: The Role of the Macrophage Migration Inhibitory Factor

Ischemic heart disease, manifesting as myocardial infarction (MI), remains the leading cause of death in the western world. Both ischemia and reperfusion (I/R) cause myocardial injury and result in cardiac inflammatory responses. This sterile inflammation in the myocardium consists of multiple phases, involving cell death, tissue remodeling, healing, and scar formation, modulated by various cytokines, including the macrophage migration inhibitory factor (MIF). Meanwhile, different immune cells participate in these phases, with myeloid cells acting as first responders. They migrate to the injured myocardium and regulate the initial phase of inflammation. The MIF modulates the acute inflammatory response by affecting the metabolic profile and activity of myeloid cells. This review summarizes the role of the MIF in regulating myeloid cell subsets in MI and I/R injury and discusses emerging evidence of metabolism-directed cellular inflammatory responses. Based on the multifaceted role of the MIF affecting myeloid cells in MI or I/R, the MIF can be a therapeutic target to achieve metabolic balance under pathology and alleviate inflammation in the heart.

The relationship between different exercise conditions and pericoronary inflammation as quantified by coronary CTA in coronary artery disease

Objectives

The correlation between exercise type and intensity and coronary artery inflammation in patients with stable coronary artery disease (CAD) is unknown. Therefore, this study assessed the relationship between coronary inflammation quantified by coronary computed tomography angiography (CCTA) and exercise intensity and pattern in patients with CAD.

Materials and methods

Patients who underwent CCTA between 2019 and 2023 in the second hospital of Lanzhou University were retrospectively examined. We calculated the pericoronary fat attenuation index (FAI) on the right coronary artery (RCA) as a marker of coronary inflammation. We compared basic information, exercise status, and RCA-FAI values between the two groups, and described the relationship between different exercise durations and RCA-FAI using analysis of variance and restricted cubic splines.

Results

In total, 1222 patients were included: 774 had no CAD and 448 patients had CAD. Sex (P = 0.016; odds ratio [OR]: 0.673), high-density lipoprotein (P = 0.006; OR: 0.601), low-density lipoprotein (P = 0.001; OR. 0.762), hypertension (P = 0.000; OR: 0.762), smoking (P = 0.005; OR: 0.670), and postprandial glucose (P = 0.030; OR: 0.812), household income (P = 0.038; OR:1.117), and body mass index (P = 0.000; OR:1.084) were the risk factors for elevated RCA-FAI values in the patients with coronary artery disease group. And when the exercise modality was running and aerobics, the correlation between RCA-FAI values and exercise time showed a "U"-shaped relationship. Follow-up revealed that short periods of high-intensity exercise resulted in lower RCA-FAI values.

Conclusion

RCA-FAI was significantly associated with coronary artery inflammation. Although appropriate physical activity reduced the risk of pericoronary inflammation and coronary atherosclerosis, overly prolonged exercise could exacerbate the coronary inflammatory response and increase the likelihood of CAD.