ObjectiveTo investigate the optimal administration combination of β-aminopropionitrile (BAPN) and Angiotensin Ⅱ (Ang-Ⅱ) in the establishment of SD rat aortic dissection (AD) model and the related complications. MethodsForty-two three-week-old male SD rats were randomly divided into 7 groups: a group A (0.25% BAPN), a group B (0.40% BAPN), a group C (0.80% BAPN), a group D [1 g/(kg·d) BAPN], a group E [1 g/(kg·d) BAPN+1 μg/(kg·min) saline], a group F [1 g/(kg·d) BAPN+1 μg/(kg·min) Ang-Ⅱ] and a group G (control group). There were 6 rats in each group. The intervention period was 4 weeks (groups E and F were 4 weeks+5 days). Rats were dissected immediately if they died during the experiment. After the intervention, the surviving rats were sacrificed by pentobarbital sodium, and the whole aorta was separated and retained. Hematoxylin-eosin staining was used to observe the changes of aorta from the pathological morphology. ResultsThere was no statistical difference in the survival rate among the groups after 4 weeks of BAPN intervention (P>0.05). After 5 days of mini-osmotic pumps implantation, the survival rate of rats was higher in the group E than that in the group F (P=0.008), and the incidence of AD in the group E was lower than that in the group F (P=0.001). BAPN could affect the food and water intake of rats. After BAPN intervention for 4 weeks, the body weight of rats in the group G was higher than those in the intervention groups (P<0.05). BAPN combined with Ang-Ⅱ could make the aortic intima thick, elastic fiber breakage, arrangement disorder, and inflammatory cell infiltration in rats, which conformed to the pathological and morphological changes of AD. BAPN could also affect mental state and gastrointestinal tract. ConclusionThe combination of BAPN [1 g/(kg·d)] and Ang-Ⅱ [1 μg/(kg·min)] can stably establish AD model in rats, which will provide a stable carrier for further study of the pathogenesis and therapeutic targets of AD. However, the complications in this process are an unstable factor. How to balance the influence of BAPN on other tissues and organs in the process of AD model establishment remains to be further studied.
ObjectiveTo construct the recombinant adenovirus vector carrying antisense multidrug resistanceassociated protein (MRP) and transfect the human drugresistant hepatocellular carcinoma cell line(SMMC7721/ADM). MethodsThe fragment of MRP gene encoding 5′region was cloned reversely into the shuttle plasmid pAdTrackCMV, with the resultant plasmid and the backbone plasmid pAdEasy1,the homologous recombination took place in the bacteria and the recombinant adenoviral plasmid was generated. The adenoviruses were packaged and amplified in 293 cells. Then the cell line of SMMC7721/ADM was transfected with the resultant adenoviruses.ResultsThe recombinant adenovirus vector carrying antisense MRP was constructed successfully. The viral titer was 2.5×109 efu/ml, and more than 90% SMMC7721/ADM cells could be transfected when the multiplicity of infection（MOI） was 100. ConclusionThe recombinant adenovirus vector constructed by us could introduce the antisense MRP into the human drugresistant hepatocellular cell line effectively, which would provide experimental basis for the mechanisms and reversal methods of the multidrug resistance in human hepatocellular carcinoma.
Objective To examine the effect of zinc finger protein A20 on regeneration of small-for-sized liver allograft, graft rejection and recipient rat survival time. Methods Small-for-sized liver transplantation with 30% partial liver allograft was performed by using a b-rejection combination rat model of DA (RT1a) to Lewis (RT1l) rats. The rats were grouped into rAdEasy-A20 treatment group （A20 group）, the control empty Ad vector rAdEasy treatment group (rAdEasy group) and PS control treatment group (PS group). Ex vivo gene transfer in donor liver graft was performed through portal vein infusion. Animals were assessed for survival days, expression of A20 in liver graft, liver graft regeneration, hepatocyte apoptosis, graft rejection, NF-κB activation and ICAM-1 mRNA expression in liver graft sinusoidal endothelial cells (LSECs), number of liver graft infiltrating mononuclear cells (LIMCs) and the subproportion of NK/NKT cells, and serum IFN-γ level. Results Survival day of A20 group rats was prominently longer than that of PS group rats and rAdEasy group rats (P=0.001 8), whereas survival day of rAdEasy group rats was remarkably shorter than that of PS group rats (P=0.001 8). Regeneration of the small-for-sized liver allograft was markedly augmented by A20, BrdU labelling index of hepatocyte on postoperative day 4 was significantly increased in the A20 group compared with the PS group and rAdEasy group (P＜0.01). Hepatocyte apoptosis on postoperative day 4 was significantly inhibited by A20 (P＜0.01). On postoperative day 4, histologic examination revealed a mild rejection in the A20 group but a more severe rejection in the PS and rAdEasy groups. NF-κB activity and ICAM-1 mRNA expression in LSECs on postoperative day 1 were notably suppressed by A20 overexpression. Flow cytometry analysis showed a marked downregulation of LIMCs number by A20, including more prominent decrease in the subproportion of NK/NKT cells on postoperative day 1 and 4, respectively (P＜0.05). Serum IFN-γ level on postoperative day 4 was also significantly suppressed by A20 overexpression (P＜0.05). Conclusion These data suggest that A20 could effectively promote small-for-sized liver allograft regeneration, suppresses rejection and prolong survival days of recipient rats. These effects of A20 could be related to an inhibition of LSECs activation, suppression of infiltration of LIMCs and the subpopulations such as NK cells and NKT cells into liver graft, and inhibition of hepatocyte apoptosis.