Cloning of human tissue-type plasminogen activator(t-PA) cDNA, construction of its ad-enovirus vector and its expression in small-diameter vascular anastomotic sites in vivo / 医学研究生学报

ABSTRACT

Objectives:To study the effects of gene therapy with tissue type plasminogen activator(t PA)cDNA on the formation of thrombo embolism in vascular anastomotic sites. Methods:①The cDNA encoding t PA was amplified by RT PCR using the isolated total RNA as the template from the Bowes melanoma cells.②Recombinant plasmid pAdCMV t PA was cotransfected into 293 cells with pJMa 17 ,and the infectious but replication deficient AdCMV t PA was generated.③The rats were randomly divided into the control and treatment groups.11 0 nylone medical suture was applied to perform rat carotid artery end to end anastomoses.In the treatment group,AdCMV t PA solution was injected into the vascular anastomotic site while AdCMV (no containing t PA DNA) solution was injected into the control group. By means of RT PCR and chromogenic plasmin substrates,the following results were obtained. Results:①The t PA cDNA was successfully cloned and its eukaryotic expressing vector was constructed.②When the isolated RNA was performed with RT PCR,1.69 kb band appeared in the treatment group while the band could not be found in the control group.The t PA activity could be detected postoperatively on the 1st,2 nd,3 rd,4 th,5 th,6 th,7 th,10 th and 13 th day of the treatment,but could not be detected in the control group. Conclusions:The t PA gene can produce t PA having biological activity at anastomotic sites, possibly prevent the formation of thrombus embolism effectively and develop the anastomotic patency.