II. Pericytes and vasculature
The role of normal vasculature is to provide tissues and organs with blood supply and nutrients. Pericytes are elongated fairly undifferentiated mural cells that line the arterioles and epithelium outside the basement membrane. Endothelial cells shape the lining of the vascular tube, while, mural cells associate with the exterior of the tube. Pericytes are involved in the regulation of blood flow and the transformation of new blood vessels. Typically, pericytes colocalize with capillaries and they play an important role in the process of vascular maturation and stabilization. Classified as either smooth muscle cells or pericytes, mural cells are identified based on the types of vessels they are connected with and what molecular markers they express [1, 2]. It is well known that Regulator of G-protein Signaling 5 (RGS-5) is expressed in pericytes of vessels undergoing angiogenesis. .
In a study that used the growth factor sphingosine-1-phospate (S1P) to stimulate cultured vascular smooth muscle cells, RGS-5 expression was constrained to the leading edge of migrating pericytes. This restriction of RGS-5 greatly reduced cell migration suggesting that RGS-5 may control the inhibitory response of pericytes to growth factors leading to vessel stabilization. Interestingly, the animals in our study carrying a tumor xenograft with induced RGS5 over-expression tended to show a more stable tumor, and had a better survival outcome. In the essential process of pericyte recruitment to endothelial cells during development, RGS5 has shown the ability to regulate PDGFR-β signaling in vitro. This further goes along with the potential role of RGS-5 during pericyte migration. Interestingly, it is known t...
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The concept of tumor heterogeneity being related to the course of the disease and clinical outcome in cancer patients draws additional attention in the era of personalized medicine (1). Current cancer treatment strategies are based on the site of origin of the primary tumor. However, it was shown that tumors developed from distinct cell types differ in their prognosis and response to cytotoxic therapies (2...
Atherosclerosis is a pathological condition that underlies several important adverse vascular events such as stroke, cerebrovascular disease, Coronary Artery Disease (CAD). etc. [1]. It is responsible for most of the cardiovascular morbidity and mortality in the Western World currently [2]. As a result of the adoption of the western life style, its prevalence is increasing all over the world and could likely reach epidemic status in the coming future [2]. Atherosclerosis is a chronic disease of the arterial wall whose underlying pathogenesis involves an imbalanced lipid metabolism and a maladaptive immune response involving chronic inflammation of the arterial wall [1]. Leukocyte trafficking shapes the disturbed equilibrium of lipid accumulation, immune responses and their clearance and homeostasis, and this leukocyte trafficking is governed by chemokines and their receptors [1]. Chemokines are a superfamily of small structurally related chemotactic cytokines, which are involved in leukocyte trafficking and activation [3]. Chemokines have been found to play major roles in selectively recruiting monocytes, neutrophils, and lymphocytes, as well as in inducing chemotaxis through the activation of G-protein-coupled receptors [4]. Additionally, chemokines and their receptors have been identified as key players in the progression of atherosclerosis, thus they are explored in order to find therapeutic targets to prevent or treat Atherosclerosis and by targeting the chemokine system various entry points for a causative treatment are offered [5]. In this essay, the role of chemokine system in atherosclerosis is visited, the strategies employed to target chemokines as a therapeutic pathway for atherosclerosis and clinical trials undertaken ...
The smallest arteries are called arterioles and they play a vital role in microcirculation. Microcirculation deals with the circulation of blood from arterioles to capillaries to venules the smallest veins. The liver, spleen and bone marrow contain vessel structures called sinusoids instead of capillaries. In these structures blood flows from arterioles to sinusoids to venules.
The locally invasive characteristic of this tumor involves vertical penetration through the skin and into the dermis and subcutaneous (under-the-skin) tissues of the malignant melanocytes. With the exception of the nodular variety of melanoma, there is often a phase of radial or lateral growth associated with these tumors. Since it is the vertical growth that characterizes the malignancy, th...
The walls of arteries are made up of three layers same as veins. Its inner endothelium is composed of epithelial cells which is very smooth. This layer helps minimise the friction. The tunica media provides strength and elasticity. It contains smooth muscles, collagen and large amount of elastic fibres.
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...survivors of myocardial infarction, number of damaged arteries is correlated with vitamin D binding protein. Vitamin D deficiency is correlated with high prevalence of double or triple vessel CAD and lower brachial artery flow-mediated dilations. Animal studies, including two studies conducted on atherosclerotic monkeys support the reverse association between concentrations of VDRA with plaque size and thickness. This association was not observed in monkeys with low VDR and high 25(OH)D3.
They arise in the interstitial spaces of organs and tissues and they then join with the large veins just before they enter the vena cava of the heart. These lymphatic vessels tend to run parallel with the veins which allows filtration to occur. The vessels are non- muscular and contain valves which stop the fluid from going back. (Hastie, 2012).
Artherosclerosis is characterized by fatty deposits that develop as streaks inside the lining of arteries and some streaking can be found in teenagers and then by an increasing proportion of the population from then on. If you were to ask the experts what causes arteriosclerosis the answer would depend on the expert. Researchers do not agree on the causation but they have agreed on possible risk factors such as smoking, a high fat diet, high cholesterol levels, high blood pressure, high iron levels, inflammation and bad genes. None of which appear to be the primary cause because if you were to eliminate one possible cause you should eliminate the disease. Many researchers have begun to think that many diseases including cancers originate as a composite of risk factors and that approach does not make sense because it suggests that Human arteries are so fragile that any one or combination of the...
Hemodialysis and Peritoneal Dialysis To the majority of Americans, dialysis is a confusing process that they will hopefully never have to endure, but for hundreds of thousands of people, it is a daily fact of life. According to US News and World Report, “In the United States, almost 400,000 people undergo dialysis every year.” (Gordon, 2012, para. 4)
The arteries supply blood rich in oxygen to the body, the veins direct deoxygenated blood from the capillaries back to the heart. These roles make up the circulatory function. Blood flow through these blood vessels can be disrupted resulting in peripheral vascular diseases. These diseases occur as a result of narrowing or blocking of the blood vessels. The risk factors of peripheral vascular diseases include diabetes, smoking, high level of cholesterol, overweight, high blood pressure etc. these risk factors result to aneurysms, Raynaud’s diseases, Buerger’s disease, renal artery disease etc. With this diseases, the peripheral vascular system should be assessed to enable nurses and other health personnel make good