The Effect Of Adiponectin On Reverse Cholesterol Transport In Macrophages And Its Mechanism

At present,around the world,the incidence of cardiovascular disease and mortality are located at the top,significant threat to people's physical and mental health.At present,the cardiovascular disease of about 230 million people,of which about 3 million people have died of the disease.Heart cerebrovascular disease in the Atherosclerosis(Atherosclerosis,AS)AS the key pathological basis,give priority to with cholesterol metabolism disorder of lipid metabolism disorder is an important pathogenic factors;The disease is the most important pathological characteristics of macrophages can remove the high level of lipid produce foam cells.Based on the above background,the researchers are keen to explore the occurrence of atherosclerosis development mechanism,and how to avoid the formation of foam cells.Reverse Cholesterol transport(Reverse Cholesterol ransport,RCT)refers to the cells contain Cholesterol to extracellular dissociation,and gather to the liver,the final out of the body;RCT process includes the following steps:initial peripheral cell contains a lot of cholesterol by the transporters(such as ABCA1 and ABCG1)mediated,in turn,combining in apolipoprotein,generate the mature state of HDL,again with gathered in the liver,blood system and expel the body.Transporter ATP combination box(Binding Cassette from the,ABC)belong to the largest number of plasma membrane family at present.The ATP adenosine triphosphate combined box transporter A1(ABCA1)is the most prominent transporters transit time function,help cells from cholesterol.In ABCA1 transporters lipid can occur under the action of outflows,combining in apoA-i,then produce a certain level of phospholipid-apoA-i compounds,and be able to cholesterol esterification extracellular free state,eventually can generate mature state of HDL,as gathered in the liver,blood system and can be used by the liver and bile acid salt is generated,and the faeces[1-3].So,enhance the level of RCT helps prevent AS lesions.Research results show that the High Density Lipoprotein(High Density Lipoprotein Cholesterol,HDL-C)and the body of the possibility of atherosclerosis was significantly negative correlation.HDL-C antagonist main mechanism is that mediated RCT process of atherosclerosis.RCT among them can peripheral tissue embedded some cholesterol by HDL-C transfer to the liver in the form of bile acid eduction body outside,is the related researchers recognized as the key to resistance to atherosclerosis mechanism.ABCA1 in RCT facilitates precursor cells phospholipid,cholesterol to HDL-C apoA-i transhipment,form new HDL-C,then start the RCT,so ABCA1 in RCT and HDL-C new generation plays an extremely important role in starting the speed limit.So whether by regulating the expression of ABCA1 protein to promote reverse cholesterol transport become widely attention of the target of atherosclerosis.Adiponectin(Adiponectin)mainly comes from fat cells,can play to insulin resistance,resistance to atherosclerosis,anti-inflammatory effect,etc.Research shows that:in obesity,high blood pressure,diabetes,myocardial damage,atherosclerosis and other patients have lower level in the serum adiponectin.And,a lot of clinical trial results showed significantly lower adiponectin concentration and high blood pressure,vascular endothelial damage and the occurrence of coronary heart disease and myocardial infarction lesions such as development closely linked[4].AS is happening in the disease process,adiponectin to undertake inhibition of vascular smooth muscle cell differentiation,reproduction,and avoid constantly into foam cells,macrophages that adiponectin plays AS resistant effect in endothelial cells.Adiponectin on the influence and mechanism of macrophage reverse cholesterol transport in\in the early coronary atherosclerosis AS endothelial cells may be inflammatory cell activation in deposition on the walls of blood vessels and dose dependent inhibition of TNF induced in human aortic endothelial cells adhesion when the hardening of the arteries or other large vascular lesions of adiponectin would gather in the damaged caused on the walls of blood vessels,the consumption of adiponectin in patients with plasma adiponectin with the development of atherosclerosis in progressive lower adiponectin levels,is an independent risk factor for coronary atherosclerosis development adiponectin lack of mice at the time of arterial injuries are characterized by severe intimal thickening using exogenous adiponectin can make the intimal proliferation improve male adiponectin is often less than some people think that women may be one reason for the female incidence of coronary heart disease(CHD)is lower than the male recently happened in adiponectin levels in patients with cardiovascular diseases reduce elevated adiponectin each mu 1 g/ml cardiovascular fell 3%adiponectin may reduce the risk of tumor necrosis factor of TNF alpha to stimulate the expression of adhesion molecules inhibit the growth of peripheral mononuclear cells and the release of inflammatory cytokines have protect endothelial anti-inflammatory antagonism atherosclerosis role its level and negatively correlated with triglyceride apolipoprotein and high density lipoprotein and apolipoprotein A-I were positively correlated.This topic through the cell and animal level two parts to discuss the influence of adiponectin in reverse cholesterol transport.Select the Adiponectin gene knockout mice(Adiponectin-/-GeneKnockOutMice)as the research animals,for eight weeks insisted that high-fat feeding,atherosclerosis model was established.Animal blood lipid levels of adiponectin group change situation for testing;Mice after injection of 3 h-TC,the liquid flash counter on adiponectin processed animal liver,blood serum,feces containing some cholesterol outflow for testing;By Western blot,PCR method of adiponectin treated animals ABCA1 mRNA level,protein content,in-depth analysis of the impact of adiponectin in RCT and related mechanism,to prevent the happening of the disease clinically development gives a new direction,new ideas.1.adiponectin by liver X receptor alpha signaling pathways raised RAW264.7 macrophages of ABCA1,ABCG1 expression and meaningObjective:In vitro study of adiponectin APN is through the liver X receptor alpha signaling pathways affecting RAW264.7 source sex foam cells containing some ABCA1,ABCG1 expression of mRNA level outflow,amount of protein,cholesterol,total cholesterol level.Methods:Cultivate RAW264.7 macrophages give ox-LDL induced into a foam cells.Real-time fluorescent quantitative PCR and westernblot were used to detect the expression of ABCA1,ABCG1mRNA and protein;Liquid scintillation counting measuring charge fat THP 1 macrophages and RAW264.7 macrophages in cholesterol rate of outflow;High performance liquid chromatography(HPLC)method to detect the contents of cholesterol in the cell.Results:Adiponectin LXR alpha signal pathways through raising RAW264.7 macrophages in ABCA1,ABCG1 expression.Conclusion:Adiponectin LXR alpha improve RAW264.7 macrophages by outflow of ABCA1,ABCG1 expression and cholesterol.For the theoretical basis is provided for the prevention and treatment of atherosclerosis.2.adiponectin in APN-/-mice ABCA1 expression of atherosclerosis and the effects of atherosclerosisObjective:Study of adiponectin in adiponectin gene knockout mice(APN-/-mice)the influence of reverse cholesterol transport macrophage in and its possible role in resistance to atherosclerosis mechanism.1.Observe adiponectin in ApoE-/-mice the role of carotid atherosclerotic plaque;2.To investigate the adiponectin within the plaques on the nitro function of the stress and its possible mechanism;3.Observe adiponectin influence on plaque local blood flow shear stress,discuss the other possible mechanisms of inhibition of plaques.Methods:1.Model:select 4 weeks of Adiponectin gene knockout mice(Adiponectin-/-geneknockoutmice)30,high-fat feeding 8 weeks,atherosclerosis model was established.2 groups:the animals were randomly divided into 5 groups:blank control group,50 mu g/(kg,d)intervention group,150 mu g/(kg,d)intervention group,200 mu g/(kg,d)intervention group,250 mu g/(kg,d)intervention group.3.Method:four weeks,adiponectin intervention to APN-/-mice celiac injection of acetylated-TC LDL and 3 h labeled RAW264.7 macrophages suspension,enzymatic determination of serum lipid levels in mice,liquid flash counter 3 h in mice liver and serum and feces-TC or percentage of the total abdominal injection of 3 h-TC,rt-pcr and Western blot-detection of ABCA1 mRNA and protein expression level in the liver.Results:1.Compared with control group,the adiponectin intervention group obviously decrease level of serum TG,TC,LDL,HDL,rise;And this change change with adiponectin are dose dependent.2.The control group in the aortic atherosclerotic lesions,hemal wall there is a lot of lipid deposits by light microscopy,with atheromatous plaque formation,there are scattered in the foam cells;Adiponectin intervention group APN-/-mice cheng reduce aortic atherosclerotic lesions,and change with adiponectin are dose dependent.3.Serum adiponectin intervention group 3 h-TC content significantly decreased(P<0.05),liver and faeces 3 h-TC levels increased significantly(P<0.05).4.Rt-pcr test result shows that:compared with control group,the adiponectin intervention group liver tissue of ABCA1 mRNA transcription level increased significantly,and with the increase of adiponectin in dose dependent(P<0.05).5.Western blot-the results showed that compared with the control group,experimental group using adiponectin intervention liver tissue of ABCA1 protein expression level increased significantly,and with the increase of adiponectin in dose dependent(P<0.05).Conclusion:1.Adiponectin could reduce serum TC,TG and LDL levels,improve the level of HDL;2.Adiponectin can reduce aortic atherosclerosis in mice;3.Adiponectin can increase the serum cholesterol rate of outflow;4.Adiponectin can present a dose-dependent increase ABCA1 mRNA and protein expression in liver tissue.Adiponectin by raising ABCA1 to promote reverse cholesterol transport,promote intracellular cholesterol out of the country,in order to delay the occurrence and development of atherosclerosis,provides a new way of thinking for cardiovascular disease prevention.