Effects of recombinant adenovirus hypoxia-inducing factor-1? (HIF-1?) on the angiogenesis in a rat model of hindlimb ischemia / 解放军医学杂志

ABSTRACT

Objective To explore the expression of recombinant adenovirus hypoxia-inducing factor-1? (HIF-1?) and its effects on the angiogenesis in a rat model of acute hindlimb ischemia. Methods (1) Recombinant adenovirus HIF-1?-Al?564 (Ad-H564 for short) was amplified in large scale in HEK293A cells and concentration gradient centrifuged in CsCl, purified by dialysis and then its titer was determined by spectrophotometry. (2) A model of acute ischemia in rats' hind limb was reproduced, and 72 rats were randomly allocated into Ad-LacZ group, Ad-H0 group, Ad-H564 group and control group (18 rats for each group). After the HIF-1? mRNA expression was detected, six rats of control group were intramuscularly injected with normal saline (NS group) to serve as control. Angiography and vascular cast were carried out in another two groups with in each six rats to serve as sham operated controls. In to hind limb skeletal muscles of rats of Ad-LacZ, Ad-H0 and Ad-H564 groups Ad-LacZ, Ad-H0 and Ad-H564 were respectively injected, normal saline was given to the rats of NS group, and nothing was given to the rats in sham group. (3) HIF-1? mRNA expression was determined by RT-PCR on the 1st, 3rd, 5th and 7th day after injection. (4) Selective arteriography and vascular cast were performed to evaluate the vascular density. Results (1) PCR and gene sequencing suggested that correct recombinant adenovirus HIF-1? was obtained after being amplified and purified, and the titer of adenovirus was 1011OPU/ml. (2) RT-PCR showed that the highest expression of HIF-1? mRNA (0.544 7?0.141 2) was seen in Ad-H564 group, and the value was significantly different compared with that of normal group and Ad-LacZ group (P=0.000), but it did not show significant difference compared with that of Ad-H564 group and Ad-H0 group (0.533 0?0.041 6, P=0.368). The expression of HIF-1? mRNA reached the highest value on the 7th day in all the groups. (3) Arteriography on the 28th day after injection showed that the density of the collateral vessels was higher in Ad-H564 group than that in Ad-H0 group, but no significant difference was found. Vascular casts showed denser microvasculature in Ad-H564 group than that in the other groups. Conclusions The present study suggests that single site mutation may enhance the expression of human HIF-1? gene in the local muscles, facilitate angiogenesis in the ischemic tissue, but no significant difference was found between the wild-type and the mutated HIF-1? genes.