The Relationship Among Dendritic Cells, Coronary Artery Atherosclerosis And Coronary Collateral Circulation And The Effect Of Simvastatin Intervention

PartⅠThe Relationship Among Dendritic Cells,Coronary ArteryAtherosclerosis and the Effect of Simvastatin InterventionBackground: Many results from both basic and clinical researchesdemonstrated that atherosclerosis (AS) had been closely related toinflammation and immunity, which involved in the whole progression ofAS. Some investigators even brought out that AS was actually a processof chronical inflammatory reaction. In various stage of AS, theinflammatory reaction was not exactly the immune response and theeffects of inflammation and the immunity were also differed from eachother; at the same time, inflammation and immune response directlyaffect the stability of the plaque and determine the clinical manifestationand prognosis of AS patients, thus their effects attracted more and moreconcentration. Dendritic cells are extensively distributed antigen-presenting cells (APC) in the body. They are the strongest professionalAPC and the only initiator of naive T lymphocytes. DCs activate Tlymphocytes through the 2nd or co-stimulatory signal. They are the keyinitiator of immune response and play critical role in immunity. Statinsare inhibitors of HMG-CoA. It was demonstrated that statins could inhibitinflammatory reaction of endothelial cells, improve the function ofvascular endothelium and stabilize the plaques. They had the effect ofanti-inflammation besides the function of lowing the blood lipids.Strengthened statins therapy could delay, block even reverse theformation of AS plaques and this function was independent of thefunction of lowering the lipid. The mechanism of anti-inflammation andblockage or reversion of AS is still not clarified today. This study aimedto detect the number, characteristics and immune status of dendritic cellsin severe late-stage coronary heart disease patients in condition withstatins in vivo or in vitro and thus explored the possible immunemechanism of AS and the mechanism of anti-inflammation of statins.Methods: According to the results of selective coronary angiography, 20 negative control (no obvious atherosclerosis, group A), 20 severecoronary heart disease patients with severe coronary stenosis without anystatins(AS group, group B) and 20 severe coronary heart disease patientswith severe coronary stenosis with simvastatins 40 mg daily for at least30 days(Simvastatin group, group C). 20 ml blood samples wereextracted through the angiographic catheter. Density gradientcentrifugation was used to separate mononuclear cells (MNCs). MNCswere cultured in vitro and induced differentiated to DCs by GM-CSF andIL-4.After MNC separation, samples of group B were divided into B1and B2. In B2 group, 100μmol/L Simvastatin were added into culturemedia on day 5. Half media were changed and observation of cellmorphology were performed every other day. All cells were harvestedon day 9. Count the cell number by hematometer. The percentage ofCD1a positive cells was considered the percent of dendritic cells acquired.Flow cytometry was used to detect the immune characteristics of DCs.Percent of CD1a~+, CD1a~+CD80~+, CD1a~+CD83~+, CD1a~+CD86~+ cells andthe mean fluorescent intensity (MFI) were measured and recorded. Mixedlymphocyte reaction (MLR) had been applied to demonstrate the functionof DCs. Stimulation index was calculated according to the formula,SPSS 13.0 was used to analyze all the data.Results: (1) After in vitro proliferation, mononuclear cells fromcoronary artery could differentiated into dendritic cells and themorphology of DC did not differ between groups. (2) Compared withnegative controls, the percent of CD1a~+, CD1a~+CD80~+, CD1a~+CD83~+,CD1a~+CD86~+ cells, MFI, MNC number, DC number and stimulationindex(SI) in group B1 were significantly increased(p＜0.05). (3)Compared with group B1, The MNC number in group B2 was notsignificantly higher, but the percent of CD1a~+, CD1a~+CD80~+,CD1a~+CD83~+, CD1a~+CD86~+ cells, MFI, DC number and stimulationindex (SI) were decreased significantly (p＜0.05); (4) Compared withgroup B1, the percent of CD1a~+, CD1a~+CD80~+, CD1a~+CD83~+,CD1a~+CD86~+ cells, MFI, MNC number, DC number and stimulationindex (SI) in group C were significantly decreased (p＜0.05).Conelusions:(1)In coronary heart diseases with severe stenosis, the number of dendritic cells and the expression of CD molecules increasedsignificantly, the maturation and stimulation intensity enhanced. DCplayed a key role in the late stage of coronary atherosclerosis; (2)Simvastatin could inhibit the differentiation of DC, decrease the numberof DC, reduce the expression intensity of CD83 and CD86, inhibit thematuration of DCs and thus weaken the stimulation function of DC; (3)In coronary heart diseases with severe stenosis, orally simvastatin couldinhibit the differentiation and maturation of DCs; (4) Simvastatin in vivoand in vitro could significantly decrease the nuber of DC, inhibit thematuration and immunity of DCs; (5) The anti-inflammation of Statinwas functioned through the inhibition of differentiation and maturation ofDCs. PartⅡThe Relationship Among Dendritic Cells, MCP-1 andCoronary Collateral Circulation in Coronary Heart DiseaseBackground: Many studies have demonstrated that the formationof coronary collateral circulation (CCC) in the patients with severecoronary artery stenosis is closely associated with clinical manifestationand prognosis of coronary heart diseases. Good CCC could restrict andreduce the area of myocardial infarction, decrease the formation ofventricular aneurysm, improve the function of left ventricular, decreasethe major cardiovascular events,improve the quality of patients' life andincrease the survival rate; Monocytic chemotactic protein-1 (MCP-1) isone of the members of chemotaxin family and usually secreted bymononuclear cells (MNCs). The results of animal experimentsdemonstrated that MCP-1 could accelerate the process of AS and alsohave the function of angiogenesis peptide; MCP-1 could promote theformation of peripheral collateral circulation in late AS stage. Dendriticcells (DCs) are extensively distributed antigen-presenting cells (APC)in the body. They are the strongest professional APC and the onlyinitiator of naive T lymphocytes. DCs are the key initiator of immuneresponse and play key role in immunity. Many evidences have shownthat DC played an important role in early stage of AS and accelerate theprogression of AS; the migration of DCs is the prerequisite for theirfunction. Now, it is clarified that chemotaxins were the key regulatoes ofDC migration. The mechanism for CCC formation has not been fullyunderstood. The relationship between DC and CCC formation had notbeen reported. The aim of this research was to investigate therelationship among serum MCP-1, status of DCs and the formation ofCCC.Methods: 40 patients who undertook selective coronary angiographyduring May, 2006 to December, 2006 and with≥95% stenosis in eitherLAD,LCX or RCA were recruited. Rentrop grading system was used torete the CCC and patients were grouped into CCC group (Group A, n=22)and non-CCC group (group B, n=18). ELISA was applied to measure the serum MCP-1 concentration and DCs were cultured and evaluated byflow cytometry. SPSS 13.0 had been applied to analyze all the data.Results: (1) After in vitro proliferation, mononuclear cells fromcoronary artery could differentiated into dendritic cells and themorphology of DC did not differ between the two groups; (2) The MCP-1concentration in non-CCC group was 83.39±31.05 pg/ml and in CCCgroup was 115.22±37.93 pg/ml; the serum MCP-1 concentration of CCCgroup was significantly higher than that of non-CCC group (p=0.007); (3) In CCC group, the serum MCP-1 concentration was positivelycorrelated to CCC grading (r=0.695, P=-0.0003); (4) The number ofmononuclear cells(MNC no) in CCC group was 3.95±1.41×10~6 andthat in non-CCC group was 2.76±0.92×10~6, the MNC no wassignificantly increased in CCC group (p=0.003); (5) The number of DCin CCC group was 1.54±0.96×10~6 and that in non-CCC group was 0.99±0.46％10~6, (p=0.033); (6)There was no statistical significance in thepercent of CD1a~+, CD1a~+CD80~+, CD1a~+CD83~+, CD1a~+CD86~+ cells, andMFI between the two groups(p＞0.05); (7) The SI in CCC group was 4.96±2.30 whereas in non-CCC group was 2.66±1.04, the SI in CCC groupincreased significantly (p=0.0003).Conclusion: 1, In severe coronary stenosis, the patients with CCCformation had higher serum MCP-1 concentration; 2, MCP-1concentration increased with the grade of CCC; the serum MCP-1 waspositively correlated to CCC grading; 3, In severe coronary stenosis, thepatients with CCC formation had higher number of DCs and higher SI.