Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162871 (abdominal aortic aneurysm)
 8,664 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

While the renin-angiotensin system (RAS) is widely recognized to be involved in atherosclerosis, its potential role in the progression from atherosclerotic lesions to abdominal aortic aneurysm (AAA) is poorly understood. The present study aimed to investigate which components of the RAS may render the atherosclerotic aorta aneurysmatic. The expression of renin, prorenin/renin receptor, angiotensinogen, AT1- and AT2 receptors, cathepsin D, cathepsin G and chymase was examined by immunoblotting and immunohistochemistry in human atherosclerotic, aneurysmatic and healthy aortic tissues obtained from patients undergoing elective repair or at autopsy. AT1- and AT2 receptor mRNA expression was determined using quantitative real-time RT-PCR. All investigated local RAS components were up-regulated in atherosclerotic as compared to healthy tissues. AAA compared to atherosclerosis was characterized by a further increase in the expression of all RAS components except for the AT2 receptor. Cathepsin D was exclusively up-regulated in AAA. Most RAS components co-localized with infiltrating leukocytes or mast cells pointing to their contribution to inflammatory processes. Due to their proteolytic features, some RAS components (cathepsin D and cathepsin G and chymase) may contribute to AAA formation by accessory mechanisms. Taken together, our data suggest that in humans, RAS activation is not just a key-player in the pathogenesis of atherosclerosis, but that a further increasing activation may be involved in the transition from atherosclerosis to AAA.
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PMID:Transition from atherosclerosis to aortic aneurysm in humans coincides with an increased expression of RAS components. 1919 79

Abdominal aortic aneurysm is a vascular disease which, despite the fact that it shares common risk factors with atherosclerosis, develops in parallel but as a partly independent process, through different pathogenic mechanisms. The pathogenic mechanisms involve metalloproteinase and collagenase activation, median and adventitial degradation, elastin lysis, vascular smooth cells transformation and apoptosis, collagen production and lysis imbalance combined with excessive inflammatory infiltration. Endothelial cells respond to a number of stimulating factors, including smoking, hypertension and AT1 receptor stimulation and non-uniform distribution of wall stress. Their ability to produce NO is crucial in order to adapt. Endothelial cells contribute to AAA development due to increased oxidative stress which is partly mediated by impaired NO bioavailability due to endothelial dysfunction and NADPH oxidase overexpression. In addition, they express several molecules among which adherence molecules, selectins, endothelin-1, regulating inflammatory infiltration and oxidative stress. Inflammatory cells consist of monocytes, polymorphonuclear neutrophils and lymphocytes and they are involved in the degrading process in the aortic wall by secreting proteolytic enzymes or by releasing interleukins which mediate the inflammation response. Endothelial dysfunction and arterial stiffness reflect on indices like FMD, carotid-femoral PWV and augmentation index, sometimes with controversial results. At present, surgical treatment is the only option provided in patients with large AAA, in particular. Focusing on the emerging role of endothelial cells in AAA pathology may contribute in creating new therapeutic options in a disease which has not yet a well-accepted, implemented pharmaceutical treatment.
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PMID:The Role of Endothelial Dysfunction in Aortic Aneurysms. 2630 38