Effect Of Mature And Function Of Dendritic Cells By CRP, E-LDL And Diltiazem

Coronary heart disease(CHD) is one of the king diseases which threat our health. Atherosclerosis(AS) is the pathological reason of CHD.Over the past decade, however,people have come to appreciate a prominent role for inflammation in the development and progression of atherosclerosis and its complications.With the development of experimental technique,accumulating evidences suggest that chronic inflammation is involved in the generation and progression of atherogenesis.C reactive protein(CRP) is intimately related with CHD,With the advent of high-sensitivity assays,CRP has emerged as one of the most powerful independent predictors of cardiovascular disease.CRP is one kind of acute-phase proteins which rised rapidly at inflammation or infection.CRP is considered solely as a non-specificial biomarker of inflamed diseases such as arthritis deformans or vasculitides in clinic.As a part recognizing molecule,CRP activates homologous immune system at autoimmune diseases.CRP shows both antiimflammatory and proimflamatory properties in vitro.It promotes proimflamatory factor IL10,on the other hand,it also reduces proimflamatory factor IFNγ,and inhibites conjugation of antibody and antigen by blocking epitope.This may be one of the mechanisms of anti-autoimmune which can counteract the damage of many inflammatory factors.The abnormal metabolism of low density lipoprotein(LDL) plays a vital role in development of AS.Native LDL lacks inflammatory properties,so the lipoprotein must undergo biochemical alterations to be atherogenic.LDL in the arterial intima facility is modified by many factors such as oxidized,acetylated or enzyme modified. Among several other candidates,two different concepts of lipoprotein modification are propagated,the widespread oxidation hypothesis and the less common E-LDL hypothesis.E-LDL might be more important for the inflammatory initiation of atherosclerosis,while oxidative modification of LDL might be more helpful for diagnosis and prognosis of the disease.As a major factor in AS,E-LDL is got by treatment of LDL with trypsin, cholesterol esterase and neuraminidase.Tissue proteases could degrade the lipoprotein B shell,rendering underlying lipids accessible to cholesterol esterase. Release of fatty acids would increase the relative content of free cholesterol.These particles were easily combined with scavenger receptor and rapidly taken up by human macrophage,then induced it to foam cell.At the same time,the multiple enzyme modification promotes fusions of LDL particles which can active complement,and the action is irrelevant with ox-LDL.The deposition of E-LDL induces the upregulation of many cytokines such as MCF-1,IL-6 and little IL-1βor TNF-α,which are important in the progress of atherosclerosis.E-LDL,not ox-LDL or native LDL was found in early stage of atherosclerosis.Some evidences show that CRP,E-LDL and complement but not ox-LDL co-locates in the early atherosclerotic plaque.One CRP can bind with 5 molecules of E-LDL,then combine with CRP receptor on macrophage which uptake ELDL and transform to foam cells.CRP was also recognized by FcγRⅡa on macrophage or monocyte and induced them to apoptosis.Dendritic cell(DC) is important in kinds of immunity reactions.The initiation step to priming immune response is the immediate contact between leukomomocyte and antigen presenting cell(APC).DC is the most functional APC in our bodies and initiate immunity reactions.Studies show that DCs are aggregate in AS lesions.It is to say that CHD is an autoimmune disease for some reasons.Diltiazem is a calcium antagonist which can inhibit the calcium influx,and is commonly used in clinic.Some researches show that Diltiazem could directly induce immunity suppression.United with cyclospotin A or urbason,Diltiazem regulated the homogeneity of human immunity.In atherosclerosis,the function of DC was affected by many factors such as LDL, CRP,kinds of cytokines and calcium influx.The changing of CRP and LDL in the progression of CHD affected the mature and functions of DCs.It is necessary to find which one is more important.In addition,we will investigate whether diltiazem could regulate DCs immunity function which was elicited by E-LDL and CRP.Our experiments can be divided into three portions:first,DCs were incubated by using E-LDL,CRP or both of them added to the nutritive medium;the surface antigens and cytokines of DCs were observed;the proliferation of allogeneic T lymphocyte(ATLP) were detected;to investigate the effect of DCs treated by E-LDL or CRP.Second,DCs were treated by E-LDL/CRP and diltiazem;the surface antigens,cytokines and ATLP of DCs were observed;to investigate the function of DCs treated by Diltiazem.Third,the AS rats were modeled;the disposition of DC in AS were compared with that treated by diltiazem.Result:1.Collected the suspension cells treated for 48 h,and detected the molecules expressed on the cell surface by FACS analysis.The expressions of CD1a, CD80 and CD86 in each group were significantly different(F＝3.131,7.761,4.585; P＝0.037,0.000,0.008).Compared with the negative PBS group,the expression of CD80 in CRP group decreased significantly while CD1a CD80 and CD86 in ELDL group were up-regulated,in E-LDL/CRP group only CD86 were higher than PBS group.Compared with CRP group,CD1a,CD80 and CD86 over expressed in E-LDL/CRP group;on the other hind,the CD80 of E-LDL/CRP group decreased significantly in comparing with E-LDL group.The expression of IL 12 and TNFαhad significantly difference(F＝9.610,5.035, P＝0.000,0.005).TNFαof CRP group was lower than PBS group;IL12 and TNFαin ELDL group were higher than PBS group.In ELDL/CRP group,TNFαwas higher than PBS group,IL12 and TNFαwere higher than CRP group,all cytokines were not significantly different compared with ELDL group.The A values of each group were significantly different(F＝10.422,P＜0.001). The ATLP in ELDL group was stronger than CRP and PBS group.The ATLP in CRP/E-LDL was attenuated than ELDL group and stronger than CRP group.2.The expressions of CD1a,CD80 and CD86 in each group were significantly different(F＝11.174,12.808,6.772;P＝0.000,0.000,0.004).The CD1a and CD80 of DIL group were decreased in comparing with PBS group;the expressions of CD1a, CD80 and CD86 decreased significantly in comparing with CRP/ELDL group.The expression of IL12 and TNFαhad significantly difference(F＝12.300, 19.270,P＝0.000,0.000),but IL6 had not.In DIL group,the expressions of IL12 and TNFαboth were down-regulated in comparing with PBS or CRP/ELDL group.The A values of each group were significantly different(F＝5.244,P＝0.012). The ATLP in DIL group was attenuated than CRP/E-LDL group.3.After rats were given fat diet and treated by VitD and nicotine,their TC and TG were increased in all groups,and the blood fat in fat diet group and DIL group were not significantly different.The expressions of OX62 of each group were different(F＝34.913,P＜0.001). The OX62 in fat diet group and DIL group were higher than control group,and the OX62 in Diltiazem group were down-regulated in comparing with fat diet group. According to our experiments,some conclusions can be drawn as following.1. CRP can inhibit the mature and function of DC and E-LDL can promote it.When CRP exists,the effect of E-LDL is reduced,but the function of DC is still accentuated. The effect of stimulation by E-LDL is stronger than that of inhibition by CRP.2.After treated by Diltiazem,the effect of DC mature stimulated by E-LDL was inhibition. Diltiazem may resist AS and stabilize the AS plaque by inhibiting autoimmune response.3.Diltiazem had no effect with blood fat of AS rats,but it could inhibit the aggregation of DC in AS.The conclusions manifested the effect of E-LDL and CRP to DC and how diltiazem contribute immunity system in AS.These prompt us a new thinking in prevention and treatment of CHD.