The Expression Of OPG In AAAs And Association Of OPG With Apotosis Of VSMC

Objective:.To measure the expression of osteoprotegerin(OPG) in human abdominal aortic aneurysm(AAA) of various diameters, investigate it's function in the formation and development of AAAMethod:(1) Immunohistochemistry was applied to detect the expressions of OPG in the tissue specimens of 20 AAA tissues of various diameters(6 small AAA:4.0-5.5cm,6 moderate-diameter AAA:5.5-7.0cm,4 large AAA:≥7.0cm and 4 ruptured AAA(RAAA) and 6 cases of normal human abdominal aorta in the control group.(2) Western-blot and RT-PCR was applied to detect the protein and RNA expression of OPG and MMP-9 in various diameters AAA.Result:(1) OPG mainly expressed in the media of AAA compare with normal abdominal aorta, and strongly correlated with inflammatory cells infiltration. The expression of OPG in AAA group is much higher than control group(P<0.05).(2) Western analysis and RT-PCR showed greater OPG concentrations in AAA biopsies compared with biopsies of normal aorta(P<0.05), and the expression of OPG was strongly correlated with aneurysm growth and expression of MMP-9.Conclusion:The findings of our study support an association between OPG and human abdominal aortic aneurysm growth, it demonstrating a possible feasible active role for OPG in the progression of AAA by means of stimulates MMP-9 activity and inflammatory cells infiltration. Objective To observe the morphological change of aortic aneurysm in rabbit and the expression of OPG in condition that local arterial wall shear stress is changed.Methods The animal model was created by the removal of abdominal aorta below the renal artery of donor rabbit and made a patch on the suprarenal abdominal aorta of receptor rabbit, The arterial wall below and above the patch was harvest after 7days,21 day,35days respectively. The morphological parameter of abdominal aorta was measured before operation and after operation. The level change of OPG was observed by immunohistochemistry. RT-PCR and Western-blot was applied to detect the RNA and protein expression of OPG and MMP-9 in different group. The apoptosis of VSMCs was measured by TUNELResults The blood flow was unobstructed in the abdominal aortic aneurysm of 83% survival receptor, no stenosis in stoma. The diameter of aneurysm was gradually increased as time goes by within 2 weeks(P<0.05). The content of elastin, collagen fibers and SMC in media was in a negative correlation mode with the diameter of aneurysm (P<0.05). The immunohistochemical staining showed that the expression of OPG in experiment group was higher than normal group (P<0.05) and strongly correlated with the diameter of AAA. RT-PCR and Western-blot showed greater OPG and MMP-9 concentrations in experiment group compared with normal group, and the expression of OPG was strongly correlated with aneurysm growth. TUNEL positive cells was detected much more in experiment group than normal group and have positive correlated with aneurysm growth.Conclusion1 The change of wall shear stress after the transplantation of a patch into rabbit abdominal aorta could induce AAA formation with high incidence and stability, which applies to further studies of AAA pathogenesis and prevention and cure in vivo.2 The change of local arterial wall shear stress can upregulate the expression of OPG, MMP-9 as well as the apoptosis of VSMCs.3 The expression of OPG may be have some relevance with apoptosis of VSMCs, which involved in the progression of aneurysm. Object:To investigate the effects on the apoptosis of human vascular smooth cells (hVSMCs) after silencing the OPG with specific siRNA and OPG gene over-expression.Method:OPG was subcloned into adenovirus vector to construct recombinant adenovirus, together with chemically synthesized targeted for OPG gene double-stranded siRNA were transfected into VSMCs.The expression of OPG mRNA was identified by RT-PCR and Western blot,respectively. The apoptosis of VSMCs was examined by FACS.Results:The pshRNA-OPG may inhibit the expression of OPG gene at the levels of transcription and translation. There were significant differences of the expression of OPG mRNA between the VSMCs that were transfected with pshRNA-OPG and the ones in over-expression group and control group, respectively. The apoptosis of VSMCs was be markedly increased in the OPG over-expression group than control group, while inhibit apoptosis in RNAi group. There is a positve relationship between expression of OPG and apoptosis of VSMCs.Conclusion:The adenovirus containing the small interference RNA of OPG may have an inhibitory effects on the apoptosis and endogenous expression of OPG gene at the levels of transcription in VSMCs. And the OPG gene over-expression may promote the apoptosis of VSMCs.