Role of extracellular rna in atherosclerotic plaque formation in mice

BACKGROUND -: Atherosclerosis and vascular remodeling after injury are driven by inflammation and mononuclear cell infiltration. Extracellular RNA (eRNA) has recently been implicated to become enriched at sites of tissue damage and to act as a proinflammatory mediator. Here, we addressed the role of eRNA in high-fat diet-induced atherosclerosis and neointima formation after injury in atherosclerosis-prone mice. METHODS AND RESULTS -: The presence of eRNA was revealed in atherosclerotic lesions from high-fat diet-fed low-density lipoprotein receptor-deficient (Ldlr) mice in a time-progressive fashion. RNase activity in plasma increased within the first 2 weeks (44±9 versus 70±7 mU/mg protein; P=0.0012), followed by a decrease to levels below baseline after 4 weeks of high-fat diet (44±9 versus 12±2 mU/mg protein; P<0.0001). Exposure of bone marrow-derived macrophages to eRNA resulted in a concentration-dependent upregulation of the proinflammatory mediators tumor necrosis factor-α, arginase-2, interleukin-1β, interleukin-6, and interferon-γ. In a model of accelerated atherosclerosis after arterial injury in apolipoprotein E-deficient (ApoE) mice, treatment with RNase1 diminished the increased plasma level of eRNA evidenced after injury. Likewise, RNase1 administration reduced neointima formation in comparison with vehicle-treated ApoE controls (25.0±6.2 versus 46.9±6.9×10 μm, P=0.0339) and was associated with a significant decrease in plaque macrophage content. Functionally, RNase1 treatment impaired monocyte arrest on activated smooth muscle cells under flow conditions in vitro and inhibited leukocyte recruitment to injured carotid arteries in vivo. CONCLUSIONS -: Because eRNA is associated with atherosclerotic lesions and contributes to inflammation-dependent plaque progression in atherosclerosis-prone mice, its targeting with RNase1 may serve as a new treatment option against atherosclerosis. © 2013 American Heart Association, Inc

RNase1 prevents the damaging interplay between extracellular RNA and tumour necrosis factor-α in cardiac ischaemia/reperfusion injury

© Schattauer 2014 Despite optimal therapy, the morbidity and mortality of patients presenting with an acute myocardial infarction (M1) remain significant, and the initial mechanistic trigger of myocardial “ischaemia/reperfusion (1/R) injury” remains greatly unexplained. Here we show that factors released from the damaged cardiac tissue itself, in particular extracellular RNA (eRNA) and tumour-necrosis-factor α (TNF-α), may dictate 1/R injury. In an experimental in vivo mouse model of myocardial 1/R as well as in the isolated 1/R Langendorff-perfused rat heart, cardiomyocyte death was induced by eRNA and TNF-α. Moreover, TNF-α promoted further eRNA release especially under hypoxia, feeding a vicious cell damaging cycle during 1/R with the massive production of oxygen radicals, mitochondrial obstruction, decrease in antioxidant enzymes and decline of cardiomyocyte functions. The administration of RNase1 significantly decreased myocardial infarction in both experimental models. This regimen allowed the reduction in cytokine release, normalisation of antioxidant enzymes as well as preservation of cardiac tissue. Thus, RNase1 administration provides a novel therapeutic regimen to interfere with the adverse eRNA-TNF-α interplay and significantly reduces or prevents the pathological outcome of ischaemic heart disease

Modelling the impact of atherosclerosis on drug release and distribution from coronary stents

Although drug-eluting stents (DES) are now widely used for the treatment of coronary heart disease, there remains considerable scope for the development of enhanced designs which address some of the limitations of existing devices. The drug release profile is a key element governing the overall performance of DES. The use of in vitro, in vivo, ex vivo, in silico and mathematical models has enhanced understanding of the factors which govern drug uptake and distribution from DES. Such work has identified the physical phenomena determining the transport of drug from the stent and through tissue, and has highlighted the importance of stent coatings and drug physical properties to this process. However, there is limited information regarding the precise role that the atherosclerotic lesion has in determining the uptake and distribution of drug. In this review, we start by discussing the various models that have been used in this research area, highlighting the different types of information they can provide. We then go on to describe more recent methods that incorporate the impact of atherosclerotic lesions

From basic mechanisms to clinical applications in heart protection, new players in cardiovascular diseases and cardiac theranostics: meeting report from the third international symposium on "New frontiers in cardiovascular research"

In this meeting report, particularly addressing the topic of protection of the cardiovascular system from ischemia/reperfusion injury, highlights are presented that relate to conditioning strategies of the heart with respect to molecular mechanisms and outcome in patients' cohorts, the influence of co-morbidities and medications, as well as the contribution of innate immune reactions in cardioprotection. Moreover, developmental or systems biology approaches bear great potential in systematically uncovering unexpected components involved in ischemia-reperfusion injury or heart regeneration. Based on the characterization of particular platelet integrins, mitochondrial redox-linked proteins, or lipid-diol compounds in cardiovascular diseases, their targeting by newly developed theranostics and technologies opens new avenues for diagnosis and therapy of myocardial infarction to improve the patients' outcome

Role of extracellular rna in atherosclerotic plaque formation in mice

BACKGROUND -: Atherosclerosis and vascular remodeling after injury are driven by inflammation and mononuclear cell infiltration. Extracellular RNA (eRNA) has recently been implicated to become enriched at sites of tissue damage and to act as a proinflammatory mediator. Here, we addressed the role of eRNA in high-fat diet-induced atherosclerosis and neointima formation after injury in atherosclerosis-prone mice. METHODS AND RESULTS -: The presence of eRNA was revealed in atherosclerotic lesions from high-fat diet-fed low-density lipoprotein receptor-deficient (Ldlr) mice in a time-progressive fashion. RNase activity in plasma increased within the first 2 weeks (44±9 versus 70±7 mU/mg protein; P=0.0012), followed by a decrease to levels below baseline after 4 weeks of high-fat diet (44±9 versus 12±2 mU/mg protein; P<0.0001). Exposure of bone marrow-derived macrophages to eRNA resulted in a concentration-dependent upregulation of the proinflammatory mediators tumor necrosis factor-α, arginase-2, interleukin-1β, interleukin-6, and interferon-γ. In a model of accelerated atherosclerosis after arterial injury in apolipoprotein E-deficient (ApoE) mice, treatment with RNase1 diminished the increased plasma level of eRNA evidenced after injury. Likewise, RNase1 administration reduced neointima formation in comparison with vehicle-treated ApoE controls (25.0±6.2 versus 46.9±6.9×10 μm, P=0.0339) and was associated with a significant decrease in plaque macrophage content. Functionally, RNase1 treatment impaired monocyte arrest on activated smooth muscle cells under flow conditions in vitro and inhibited leukocyte recruitment to injured carotid arteries in vivo. CONCLUSIONS -: Because eRNA is associated with atherosclerotic lesions and contributes to inflammation-dependent plaque progression in atherosclerosis-prone mice, its targeting with RNase1 may serve as a new treatment option against atherosclerosis. © 2013 American Heart Association, Inc

Role of extracellular rna in atherosclerotic plaque formation in mice

BACKGROUND -: Atherosclerosis and vascular remodeling after injury are driven by inflammation and mononuclear cell infiltration. Extracellular RNA (eRNA) has recently been implicated to become enriched at sites of tissue damage and to act as a proinflammatory mediator. Here, we addressed the role of eRNA in high-fat diet-induced atherosclerosis and neointima formation after injury in atherosclerosis-prone mice. METHODS AND RESULTS -: The presence of eRNA was revealed in atherosclerotic lesions from high-fat diet-fed low-density lipoprotein receptor-deficient (Ldlr) mice in a time-progressive fashion. RNase activity in plasma increased within the first 2 weeks (44±9 versus 70±7 mU/mg protein; P=0.0012), followed by a decrease to levels below baseline after 4 weeks of high-fat diet (44±9 versus 12±2 mU/mg protein; P<0.0001). Exposure of bone marrow-derived macrophages to eRNA resulted in a concentration-dependent upregulation of the proinflammatory mediators tumor necrosis factor-α, arginase-2, interleukin-1β, interleukin-6, and interferon-γ. In a model of accelerated atherosclerosis after arterial injury in apolipoprotein E-deficient (ApoE) mice, treatment with RNase1 diminished the increased plasma level of eRNA evidenced after injury. Likewise, RNase1 administration reduced neointima formation in comparison with vehicle-treated ApoE controls (25.0±6.2 versus 46.9±6.9×10 μm, P=0.0339) and was associated with a significant decrease in plaque macrophage content. Functionally, RNase1 treatment impaired monocyte arrest on activated smooth muscle cells under flow conditions in vitro and inhibited leukocyte recruitment to injured carotid arteries in vivo. CONCLUSIONS -: Because eRNA is associated with atherosclerotic lesions and contributes to inflammation-dependent plaque progression in atherosclerosis-prone mice, its targeting with RNase1 may serve as a new treatment option against atherosclerosis. © 2013 American Heart Association, Inc