Vascular remodeling mediated by Angptl2 produced from perivascular adipose tissue

Angiopoietin-like proteins in atherosclerosis

Atherosclerosis, as a chronic inflammatory disease within the arterial wall, is a leading cause of morbidity and mortality worldwide due to its role in myocardial infarction, stroke and peripheral artery disease. Additional evidence is emerging that the angiopoietin-like (ANGPTL) family of proteins participate in the pathology of this disease process via endothelial dysfunction, inflammation, dyslipidemia, calcification, foam cell formation and platelet activation. This review summarizes current knowledge on the ANGPTL family of proteins in atherosclerosis related pathological processes. Moreover, the potential value of ANGPTL family proteins as predictive biomarkers in atherosclerosis is discussed. Given the attractive role of ANGPTL3, ANGPTL4, ANGPTL8 in atherosclerotic dyslipidemia via regulation of lipoprotein lipase (LPL), antisense oligonucleotide or/and monoclonal antibody-based inactivation of these proteins represent potential atherosclerotic therapies.

Dietary modification reduces serum angiopoietin-like protein 2 levels and arterial stiffness in overweight and obese men

PURPOSE

Weight loss can reduce obesity-induced arterial stiffening that is attributed to decreased inflammation. Angiopoietin-like protein 2 (ANGPTL2) is a pro-inflammatory adipokine that is upregulated in obesity and is important in the progression of atherosclerosis and cardiovascular disease. The purpose of this study is to investigate the effects of dietary modification on circulating ANGPTL2 levels and arterial stiffness in overweight and obese men.

METHODS

Twenty-two overweight and obese men (with mean age of 56 ± 2 years and body mass index of 28.6 ± 2.6 kg/m2) completed a 12-week dietary modification program. We measured the arterial compliance and β-stiffness index (as the indices of arterial stiffness) and serum ANGPTL2 levels before and after the program.

RESULTS

After the 12-week dietary modification, body mass and daily energy intake were significantly reduced. Arterial compliance was significantly increased and β-stiffness index was significantly decreased after the 12-week dietary modification program. Serum ANGPTL2 levels were significantly decreased. Also, the changes in arterial compliance were negatively correlated with the changes in serum ANGPTL2 levels, whereas the changes in β-stiffness index were positively correlated with the changes in serum ANGPTL2 levels.

CONCLUSION

These results suggest that the decrease in circulating ANGPTL2 levels can be attributed to the dietary modification-induced reduction of arterial stiffness in overweight and obese men.

Impact of the cardiovascular system-associated adipose tissue on atherosclerotic pathology

Cardiac obesity makes an important contribution to the pathogenesis of cardiovascular disease. One of the important pathways of this contribution is the inflammatory process that takes place in the adipose tissue. In this review, we consider the role of the cardiovascular system-associated fat in atherosclerotic cardiovascular pathology and a non-atherosclerotic cause of coronary artery disease, such as atrial fibrillation. Cardiovascular system-associated fat not only serves as the energy store, but also releases adipokines that control local and systemic metabolism, heart/vascular function and vessel tone, and a number of vasodilating and anti-inflammatory substances. Adipokine appears to play an important protective role in cardiovascular system. Under chronic inflammation conditions, the repertoire of signaling molecules secreted by cardiac fat can be altered, leading to a higher amount of pro-inflammatory messengers, vasoconstrictors, profibrotic modulators. This further aggravates cardiovascular inflammation and leads to hypertension, induction of the pathological tissue remodeling and cardiac fibrosis. Contemporary imaging techniques showed that epicardial fat thickness correlates with the visceral fat mass, which is an established risk factor and predictor of cardiovascular disease in obese subjects. However, this correlation is no longer present after adjustment for other covariates. Nevertheless, recent studies showed that pericardial fat volume and epicardial fat thickness can probably serve as a better indicator for atrial fibrillation.

Angiopoietin-like-2: a multifaceted protein with physiological and pathophysiological properties

Angptl2 is a multifaceted protein, displaying both physiological and pathological functions, in which scientific and clinical interest is growing exponentially within the past few years. Its physiological functions are not well understood, but angptl2 was first acknowledged for its pro-angiogenic and antiapoptotic capacities. In addition, angptl2 can be considered a growth factor, since it increases survival and expansion of hematopoietic stem cells and may promote vasculogenesis. Finally, angptl2 has an important, but largely unrecognised, physiological role: in the cytosol, angptl2 binds to type 1A angiotensin II receptors and induces their recycling, with recovery of the receptor signal functions. Despite these important physiological properties, angptl2 is better acknowledged for its deleterious pro-inflammatory properties and its contribution in multiple chronic diseases such as cancer, diabetes, atherosclerosis, metabolic disorders and many other chronic diseases. This review aims at presenting an updated description of both the beneficial and deleterious biological properties of angptl2, in addition to its molecular signalling pathways and transcriptional regulation. The multiplicity of diseases in which angptl2 contributes makes it a new highly relevant clinical therapeutic target.