ABSTRACT
Objective To investigate the protective effect of a COX inhibitor,flurbiprofen (Flurb) on hepatic ischemia/reperfusion (IR) injury in rats and the action mechanism.Method C57BL/6 mice were randomized into sham,IR and Flurb (4 different doses) groups.The model of segmental (70％) warm hepatic ischemia was established in IR and Flurb groups.Flurbiprofen of different doses (5,7.5,10 and 15 mg/kg) was injected via the tail vein 20 min before ischemia.At different time points after reperfusion,liver cell necrosis and apoptosis were evaluated by HE and TUNEL staining.The COX and inflammatory cytokine gene expression was detected by using realtime PCR.Liver mitochondria were separated and mitochondrial permeability transition (MPT) pore sensitivity was examined by using swelling assay and fluorescence spectrophotometry assay.Result In flurbiprofen groups of different doses,the serum AST and ALT levels were significantly decreased at 6 h after reperfusion as compared with IR group.Moreover,10 mg/kg Flurb pretreatment significantly inhibited the mitochondrial permeability transition (MPT) pore opening,and thus alleviated liver cell damage and prevented mitochondria-related cell death and apoptosis by inhibiting COX-2 and inflammatory factor genes expression such as IL-1β,IL-6 and TNF-α.Conclusion Flurbiprofen protects mice from hepatic I/R injury possibly by inhibiting mitochondrial permeability transition and IL-1β,IL-6 and TNF-α expression,which may provide experimental evidence for clinical use of flurbiprofen to protect liver function in surgical settings other than its conventional use for pain relief.
ABSTRACT
ObjectiveTo investigate the role of aldehyde dehydrogenase 2 (ALDH2) in the protection against tubular epithelial cells (TEC) ischemia/reperfusion (IR)injury induced by pretreatment with ethanol.Methods Mouse primary cultured TECs were pretreated with 50 mM ethanol 3 h before simulation of in vitro IR.Lactate dehydrogenase (LDH) release was assessed to evaluate the protection of ethanol pretreatment on IR injury.Thereafter,TECs were transfected with a negative control siRNA (NC) or an ALDH2-siRNA. The ALDH2 protein levels and ALDH enzymatic activities were assessed 48 h after transfection.Ethanol pretreatment and in vitro IR were performed on those transfected TECs.LDH release was assessed to evaluate the role of ALDH2 in the ethanol pretreatment-induced protection against IR injury.ResultsEthanol pretreatment significantly reduced the LDH release in TECs upon IR insult.As compared with NC group and INTERFERin group,the ALDH2 protein levels were decreased by 82.1％,ALDH enzymatic activities were decreased hy 67.3％,and the protective effect induced by ethanol pretreatment was almost completely abrogated in ALDH2-siRNA group.ConclusionEthanol pretreatment protects TECs against IR injury through ALDH2 dependent pathways.
ABSTRACT
Objective To investigate the potential role of IC0s-Ig and CsA in inducing transplantation tolerance and the mechanisms thereof. Methods ICOS-Ig was a fusion protein of human ICOS extracellular region and IgG Fc fragment.Cardiac allograft from BALB/c mouse was transplanted to C57BL/6 mouse Animals were randomly divided into 5 groups:(1) un-treated group;(2)IgG-treated group,250g,i.p.day 2,4,6;(3)ICOS Ig-treated group,250g,i.P.day 2,4,6;(4) CsA-treated group,10 mg/kg,i.p.day 0-6;(5)ICOS-Ig+CsA-treated group.The survival time and pathological changes of the cardiac allografts were monitored.The mixed lymphoeyte reaction (MLR) and the alloantibody level of the recipients were also detected.Results The median survival time (MST) of the cardiac allografts was (8.5±1.5) days in un-treated group,(8.0±0.8) days in IgG-treated group,(29.5±7.7) days in ICOS-Ig-treated group,and(21.0±5.0) days in CsA-treated group.respectively.In ICOS-Ig + CsA-treated group,the MST was prolonged to longer than 100 days,which was significantly longer than other four groups(P<0.01).Allogeneic hearts from ICOS-Ig and/or CsA immunized recipients revealeel milder histological changes than control groups(P<0.05).Mechanical ahalysis revealed that splenic T cells from recipients also exhibited depressed MLR activities.The alloantibody level in ICOS-Ig-treated group and/or CsA-treated group was lower than in control groups(P<0.05),suggesting ICOS-Ig not only inhibited cell immunity,but also depressed humoral response.Conclusion ICOS-Ig combined with CsA leads to a long-term survival of mouse cardiac allografts.The induced tolerance is donor-specific and the mechanisms may be associated with T cell anergy.
ABSTRACT
Objective To discuss the effect of sIL-1RI on allograft survival after islet transplantation.Methods Islets were isolated and transfected with Ad-sIL-1RI-Ig.Mice were treated with STZ to induce insulin-dependent diabetes mellitus(IDDM) model.Islet transplantation was carried out to IDDM mice with sIL-1RI-Ig gene-modified islet cells.Then the survival time of grafts was tested by daily observing blood glucose and insulin levels.The expression of cytokines was detected in graft after transplantation by using RT-PCR. Pathological changes of the graft were also observed by chromoscopy with HE after transplantation.Results The survival time of the grafts in sIL-1RI-Ig-islet group (39±3 days) was prolonged significantly (P<0.01) as compared with controls.A down-regulation of cytokines expression was detected in grafts after transplantation.Less damage and infiltration of lymphocytes were found in sIL-1RI-Ig gene-transfected group.Conclusion The effects of islet cells modified with sIL-1RI-Ig before transplantation on the rejection of murine islet allograft were investigated.The results verified that sIL-1RI-Ig-modified islet allograft could prolong the survival of grafts significantly,and demonstrated it was possible that sIL-1RI-Ig preventedallograft rejection via reducing the expression of cytokines(TNF-α,IFN-γ,RANTES,etc.).
ABSTRACT
Granulocyte colony - stimulating factor (G - CSF) is a hematopoietic growth factor that is responsible for the differentiation and proliferation of hematopoietic progenitor cells to mature granulocyte, and can increase the number of peripheral neutrophils. It has been demonstrated that it could inhibit the metastasis of the murine tumors in spontaneous and experimental metastasis models by in vivo administration of recombinant human G - CSF. In order to examine the antitumor effect of G - CSF gene therapy on mice receiving high - dose chemotherapy, C - 26 colon adenocarcinoma - bearing mice which were prepared by S. c. injection of 1?105C-26 cells were i. p. injected with rhG-CSF (2?g/day?14day) or implanted with 1?107 collagen encapsulated NIH3T3-G-CSF cells which secrete high level of G - CSF after gene transfection. In our experiment, rhG-CSF could inhibit the tumor growth and extend the survival time of early stage C-26 bearing mice. However, G - CSF gene therapy could inhibit the tumor growth and prolong the survival both in early or middle stage C-26 mice. The results showed that both rhG - CSF and G - CSF gene therapy have exact antitumor effect and G - CSF gene therapy show more effective than rhG - CSF in vivo. Then we investigated the therapeutic effects of G - CSF gene therapy on C-26-bearing mice receiving high - dose chemotherapy (5-Fu 150mg/mice i. p.) . More effective results could be observed in C-26 - bearing mice receiving high dose chemotherapy after G - CSF gene therapy. The results also suggested that G-CSF gene therapy can inhibit the tumor growth more effectively both in C-26-bearing mice or C-26-bearing mice receiving high - dose chemotherapy.
ABSTRACT
Neutrophils play important role in anti - tumor response of tumor-bearing host as a kind of important effector cells. In order to identify the anti-tumor mechanisms of G-CSF gene therapy, we investigated the number and functions of the peripheral neutrophils in the C-26 colon adenocarcinoma-bearing mice receiving G - CSF gene therapy and high - dose chemotherapy. After G - CSF gene therapy, the number of neutrophils in peripheral blood was increased markedly in C-26 mice receiving high - dose 5 - Fu as compared with control groups including in vivo administration of rhG - CSF. The more potent cytotoxicity to C - 26 cells could be detected. The phagocytic activity, the secretion of IL-1, TNF, NO of the neutrophils were significantly enhanced. These data showed that G - CSF gene therapy can increase the number of neutrophils, activate the functions more effectively than in vivo administration of rhG - CSF.
ABSTRACT
In the present study, we prepared cationic liposomes encapsulated IL-2 DNA or IL-6 DNA with reverse-phase evaporation to investigate their efficiency in mediating gene transfer. After transfection with IL-2 DNA liposome or IL-6 DNA liposome, the supernatants of NIH3T3 cell contained high levels of IL-2 or IL-6. The peritoneal cells from the mice injected i.p. of IL-2 DNA or IL-6 DNA liposome 10 days later could also be detected to secrete IL-2 or IL-6. The B16F10 melanoma cells from tumor-bearing mice which were injected intratumorally of IL-2 DNA or IL-6 DNA liposome exhibited resistant to G418 and secreted high levels of IL-2 or IL-6. The results show that the liposome can mediate cytokine gene transfer efficiently in vitro and in vivo.
ABSTRACT
In the present study, the effects of G-CSF gene therapy was investigated on the recovery of murine hematopoietic suppression induced by high dose of cyclophosphomide (Cy) . The results showed that G-CSF gene therapy could slow down the Cy-induced decreasing of peripheral WBCs and platelets, and accerelate their recovery.It also could increase the CFU-GM, CFU - MK, CFU-S derived from the splenocyte and bone marrow cells in the chemotherapy-treated mice. The data demonstrated that fibroblast-mediated G-CSF gene therapy could significantlyreduce the hematopoietic damage to less extent, and accerelate hematopoietic recovery after chemotherapy.
ABSTRACT
Objective: To determine the anti rejection effects of CTLA 4 Ig fusion protein on cardiac allografts in mice and to discuss its mechanism in vivo . Methods: BALB/c recipients were performed cervical heterotopic heart transplantation to receive C57BL/6 donor hearts with a cuff technique. BALB/c recipients were intraperitoneally injected with CTLA 4 Ig [100 ?g/d?15 times], control immunoglobins and PBS to observe the survival time of allografts with ECG. The hyporesponsiveness of splenic T cell, the polarization of the T subsets were analyzed after the recipients treated with CTLA 4 Ig. Results: After treated with CTLA 4 Ig, the survival of cardiac grafts was significantly prolonged compared with the control groups, and more than 40% cardiac grafts survived over 2 months. The splenic T cells isolated from recipients did not respond to restimulation of donor splenocytes in MLR, but did exhibit the capacity to proliferate in response to C3H splenocytes(third party).The levels of IL 2 and IFN ? decreased and the level of IL 10 increased in CTLA 4 Ig treated mice. Conclusion: Administration of CTLA 4 Ig can induce donor specific tolerance, which induce T subsets to polarize toward Th2 subset and hyporesponsiveness to alloantigen, and prolong the survival time of the cardiac grafts effectively. [