OPG Gene Deficient Mice Aggravate The Hindlimb Ischemia By Formal Artery Ligation

Objectivethis study compared OPG knockout mice(OPG-/-)(C57BL/6 species)and wild type(WT)C57BL/6 mice to determine the role of OPG gene in angiogenesis.MethodsWe adopted two kinds of fed models:chow-fed model and high-fat-fed model.Acoording to the results of gene identification,two groups divided.One was the OPG-/-mice group and the other was WT mice group,and all of them successfully established limb ischemia mice mode through the method of the right femoral artery ligation,determined by the result of doppler.In the chow-fed mice model,doppler scanner monitored the perfusion rate of right himdlimb to left himdlimb in 1st,3rd,7th,14th,21st days after the femoral artery ligation.we also consider the result of CD31 and a-SMA immunofluorescence and HE staining.In the high-fat-fed mice group,OPG-/-mice and WT mice have been fed the 60%fat for 8 weeks since they were 5-week-old.Doppler scanner monitored the perfusion rate of right himdlimb to left himdlimb in 1st,3rd,7th,14th,21st days after the femoral artery ligation.ResultsIn the chow-fed group,doppler result showed that perfusion rate of OPG-/-mice group is significantly lower than that of WT group in 1st,3rd,7th,14th days after the ligation and the perfusion rate of OPG-/-mice and WT mice was 0.094±0.101 vs 0.232±0.184(P<0.05),0.195±0.191 vs 0.347±0.181(P<0.05),0.414±0.238 vs 0.651 ±0.188(P<0.0001),0.665±0.318 vs 0.839±0.174(P<0.05),respectively;The gangrene severity of OPG-/-mice in 21st days was more serious than that in WT mice,the hindlimb necrosis scores of OPG-/-mice and WT mice were 1.792±1.290 vs 1.212±0.844(P<0.05).The results of immunofluorescence showed that,compared with WT mice,there was a decreasing tendency of OPG-/-mice about the markers of CD31 and a-SMA in 21st day.HE staining also showed that OPG-/-mice gastrocnemius muscle fibers in 21st day had a trend of more serious shrinking than WT mice.In high-fat-fed group,doppler result showed that the perfusion rate of OPG-/-mice and WT mice was 0.209±0.182 vs 0.520±0.156,0.197±0.187 vs 0.528±0.235,0.558±0.273 vs 0.90510.155(all P<0.01)in 3rd,7th,14th day after ligation,respectively;The gangrene severity of OPG-/-mice in 21st day were also more serious than that in WT mice,the hindlimb necrosis scores of OPG-/-mice vs WT mice were 2.333±0.615 vs 0.667±0.289(P=0.017).ConclusionDeficience of OPG gene aggravates the ischemia degree of limb muscle.One of the mechanisms may refer to the decrement of the process of angiogenesis and the research needed further studied.