Distribution Of Amyloid A Diabetic Patient Serum High-density Lipoprotein And Correlation Of Inhibiting The Expression Of Adhesion Molecules

Background:Both diabetes mellitus (DM) and coronary heart diseases (CHD) are atherosclerotic diseases accompanied by significant functional changes of lipoprotein. High density lipoprotein (HDL) is an important anti-atherosclerotic agent. In chronic inflammation and some metabolic diseases, the function and concentration of HDL vary significantly, leading to high incidence of coronary heart disease. Apolipoprotein, as a important component of HDL, plays an important role in the process of cholesterol metabolism, anti-oxidation and anti-inflammation. Findings suggest that the decreased content of apolipoprotein A I (apoA I) and markedly increased content of serum amyloid A in HDL during the acute phase response or chronic inflammation may alter the function of HDL.Previous studies provided the evidence that HDLs may protect against CHD by inhibiting the expression of adhesion molecules, which are required for the interaction between leukocytes and endothelium in a concentration-dependent manner.From these previous studies, we could suppose that the change of lipoproteins in different diseases will influence their anti-inflammatory functions.Objectives:In this case-control study we enrolled patients sufftering from DM or CHD only, or both disorders. We studied the inhibition of ICAM-1, VCAM-1expression and the cell adhesion by HDLs in different patient groups. The relationship between level of HDL-Serum amyloid A (SAA) or apoAl and anti-adhesion function was also investigated.Methods:1. Collecting plasma of normal people, patients with DM only, CHD only or both;2. Isolating HDL from plasma with ultracentrifugation; 3. Detecting the level of lipoprotein-associated SAA and apoAl with Enzyme-Linked Immuno Sorbent Assay(ELISA);4. Incubating HUVECs with HDLs for4hrs, and stimulateing the cells with TNF-α for another4hrs, then labeling HUVECs with anti-54or106monoclonal antibodys, the expression of cell-surface molecules was measured as fluorescence intensity by flow cytometer;5. Incubating HUVECs with HDLs for4hrs, and stimulateing the cells with TNF-a for24hrs, then adding the THP-1cells, which had been labeled with Calcein-AM antibody, Adherence of calcein-AM labeled THP-1cells was determined by fluorescent intensity using flow cytometer;6. Evaluate the relationship between HDL-SAA、apoAl and the anti-inflammation ofHDL.Results:1. There was no significant difference among the basic demographic characteristics, past history and laboratory values of subjects enrolled(p>0.05);2. The levels of HDL-SAA in the normal controls were lower than those patients with DM only, CHD only or both (p=0.001);3. The HDLs of all groups could reduce the expression of ICAM-1(P<0.05);4. The HDLs of all groups could reduce the expression of VCAM-1(P<0.01), the inhibition ability of VCAM-1expression by HDL was stronger in comorbidity group than in normal controls(p=0.026);5. Mean Fluorescence Intensity of THP-1labeled by Calcein-AM in normal controls and CHD only patients was significantly lower than blank control (pn=0.012, pc=0.017). Mean Fluorescence Intensity was significantly higher in DM only patients than normal controls.(p=0.038);6. The level of SAA and apoAl is independ with the expression of ICAM-1, VCAM-1and the adhesion of THP-1. Conclusions:1. The level of HDL-SAA in normal controls were lower than that in patients with DM only, CHD only or both;2. The HDLs of all groups could reduce the expression of ICAM-1, VCAM-1and the adhesion of THP-1;3. The ability of diabets patients’ HDL to inhibit the expression of VCAM-1was stronger than normal controls;4. Inhibition ablility of adhesion of THP-1by HDL was stronger in normal controls than DM only patients5. There was no relationship between levels of SAA, apoAl and the ability of inhibiting adhesion.