Effect of apolipoprotein B-100 subunit poly peptide immune on levels of lipid and areas of atherosclerotic plaque in ApoE-/-mice

Abstract:

Objective：To observe the influence of apolipoprotein B-100（apoB-100） subunit poly peptide immune on atherosclerosis（AS） of ApoE-/-mice. Methods：ApoE-/-mice were randomly divided into three groups：group A（model control group） and group B（apoB-100 p45，apoB-100 p143 and apoB-100 p210 mixture group），group C（apolipoprotein B-100 intact peptide group），with 12 mice in each group. Mice of groups B and C were given polypeptide subcutaneous immunization while those in group A was given normal saline with same volume. All animals were executed after 25 weeks’ high fat diet. Enzyme linked immunosorbent assay was performed to detect specific IgG antibody. Total cholesterol（TC），triglyceride（TG） and low density lipoprotein cholesterol（LDL-C） high-density lipoprotein cholesterol（HDL-C） levels in serum of experimental mice were detected by biochemical analyzer. The ratio of AS plaque area against lumen area was measured by image analysis software after HE staining. Results：（1）After the first immu－nization，group B and group C had significant higher level of antibody than before（1∶962.5 vs. 1∶0.121，t=9.522，P=0.000；1∶1108.3 vs. 1∶0.121，t=7.531，P=0.000）. After the second immunization，group B and group C got significant higher antibody than before（1∶3582.9 vs. 1∶0.121，t=11.972，P=0.000；1∶3824.8 vs. 1∶0.121，t=8.220，P=0.000）. After the second immunization，group B and group C got higher level of antibody than first immunization（t=3.522，P=0.009；t=3.179，P=0.007）. （2）Serum TC（16.03±1.49），TG（1.72±0.12） and LDL-C（2.15±0.16） were significantly lower in group B than in group A（23.44±1.72，3.01±0.26，3.04±0.28） while HDL-C levels（2.87±0.17） was significantly higher in group B than in group A（1.82±0.11）（t=3.289，P=0.027；t=2.766，P=0.031；t=3.025，P=0.029，t=4.187，P=0.001）. TC（17.94±1.55），TG（1.88±0.15） and LDL-C（1.97±0.14） were significantly lower in group C than in group A while HDL-C levels（3.01±0.39） was significantly higher in group C than in group A（t=4.209，P=0.001；t=5.116，P=0.000；t=6.025，P=0.000；t=3.157，P=0.026）. （3）AS sever－ity was lighter in group B and group C than in group A and ratio of AS plaque area against lumen area was lower in group B and group C than in group A（4.59±1.41 vs. 17.6±5.36，t=3.465，P=0.021；3.87±2.05 vs. 17.6±5.36，t=2.992，P=0.030）. Conclusion：apoB-100 subunit poly peptide immune may regulate the formation of AS by adjusting the blood lipid metabolism of ApoE-/- mice.