Dendritic cells (DCs) are the most potent antigen-presen ting cells that play crucial roles in the regulation of immune response. Triptol ide, an active component purified from the medicinal plant Tripterygium wilfor ...Dendritic cells (DCs) are the most potent antigen-presen ting cells that play crucial roles in the regulation of immune response. Triptol ide, an active component purified from the medicinal plant Tripterygium wilfor dii Hook F., has been demonstrated to act as a potent immunosuppressive drug c apab le of inhibiting T cell activation and proliferation. However, little is known a bout the effects of triptolide on DCs. The present study shows that triptolide d oes not affect phenotypic differentiation and LPS-induced maturation of murine DCs. But triptolide can dramatically reduce cell recovery by inducing apoptosis of DCs at concentration as low as 10 ng/ml, as demonstrated by phosphatidylserin e exposure, mitochondria potential decrease, and nuclear DNA condensation. Tript olide induces activation of p38 in DCs, which precedes the activation of caspase 3. SB203580, a specific kinase inhibitor for p38, can block the activation of caspase 3 and inhibit the resultant apoptosis of DCs. Our results suggest that t he anti-inflammatory and immunosuppressive activities of triptolide may be due, in part, to its apoptosis-inducing effects on DCs.展开更多
BACKGROUND: Lentiviral vectors, a type of retroviral vector, are able to infect cells at all phases of cell cycle. They are able to express exogenous target genes in vivo over long periods of time with limited immuno...BACKGROUND: Lentiviral vectors, a type of retroviral vector, are able to infect cells at all phases of cell cycle. They are able to express exogenous target genes in vivo over long periods of time with limited immunological reaction. OBJECTIVE: To inhibit neuronal apoptosis by blocking the apoptotic cascade reaction, gene silencing of Caspase 3, and transfection of Caspase 3 short hairpin ribonucleic acid (shRNA) into Neuro 2a cells using a lentiviral vector.DESIGN: TiME-AND SETTING: An observational, genetic engineering cellular biology experiment was performed in Guangzhou Red Cross Hospital and Guangzhou Institute of Traumatic Surgery between March 2007 and June 2008. MATERIALS: PLL3.7, PCMV-VSV-G, and PH'8.9∧PR plasmids were provided by the CBR Institute for Biomedical Research, Harvard Medical School, USA. Staurosporine was purchased from Sigma, USA.METHODS: Caspase 3 siRNA was synthesized and cloned into the PLL3.7 plasmid. The Caspase 3 shRNA-PLL3.7 Ientivirus was generated in 293T cells using a calcium phosphate transfection kit. After the lentivirus was transfected into Neuro 2a cells, apoptosis was induced in both the transfected and untransfected cells by staurosporine. Cell apoptosis was assessed by flow cvtometrv.MAIN OUTCOME MEASURES: Caspase 3 mRNA expression was measured by RT-PCR and Caspase protein expression was assessed by Western blot. Cellular apoptosis was determined by flow cytometry using Annevin V-PE/Taad-Cy7. RESULTS: The transfection rate of caspase 3 shRNA was 〉 98% using the lentiviral vector, RT-PCR and Western blot results demonstrated that significantly reduced Caspase 3 mRNA and protein expression in the transfected Neuro 2a. The control group exhibited 38.7% Annexin V/7aad-positive cells, which suggested apoptotic anaphase, while only 5.0% cells in the Caspase 3 gene silencing group entered apoptotic anaphase. CONCKUSION: Caspase 3 shRNA inhibited Caspase 3 expression in Neuro 2a ceils and decreased drug-induced apoptosis of Neuro 2a cells.展开更多
文摘Dendritic cells (DCs) are the most potent antigen-presen ting cells that play crucial roles in the regulation of immune response. Triptol ide, an active component purified from the medicinal plant Tripterygium wilfor dii Hook F., has been demonstrated to act as a potent immunosuppressive drug c apab le of inhibiting T cell activation and proliferation. However, little is known a bout the effects of triptolide on DCs. The present study shows that triptolide d oes not affect phenotypic differentiation and LPS-induced maturation of murine DCs. But triptolide can dramatically reduce cell recovery by inducing apoptosis of DCs at concentration as low as 10 ng/ml, as demonstrated by phosphatidylserin e exposure, mitochondria potential decrease, and nuclear DNA condensation. Tript olide induces activation of p38 in DCs, which precedes the activation of caspase 3. SB203580, a specific kinase inhibitor for p38, can block the activation of caspase 3 and inhibit the resultant apoptosis of DCs. Our results suggest that t he anti-inflammatory and immunosuppressive activities of triptolide may be due, in part, to its apoptosis-inducing effects on DCs.
基金Open Foundation of Key Laboratory of Biomedical Engineering,Guangdong Province,No.21030400Key Project of Guangzhou Medical and Health Care Foundation,No. 2006-ZDi-04
文摘BACKGROUND: Lentiviral vectors, a type of retroviral vector, are able to infect cells at all phases of cell cycle. They are able to express exogenous target genes in vivo over long periods of time with limited immunological reaction. OBJECTIVE: To inhibit neuronal apoptosis by blocking the apoptotic cascade reaction, gene silencing of Caspase 3, and transfection of Caspase 3 short hairpin ribonucleic acid (shRNA) into Neuro 2a cells using a lentiviral vector.DESIGN: TiME-AND SETTING: An observational, genetic engineering cellular biology experiment was performed in Guangzhou Red Cross Hospital and Guangzhou Institute of Traumatic Surgery between March 2007 and June 2008. MATERIALS: PLL3.7, PCMV-VSV-G, and PH'8.9∧PR plasmids were provided by the CBR Institute for Biomedical Research, Harvard Medical School, USA. Staurosporine was purchased from Sigma, USA.METHODS: Caspase 3 siRNA was synthesized and cloned into the PLL3.7 plasmid. The Caspase 3 shRNA-PLL3.7 Ientivirus was generated in 293T cells using a calcium phosphate transfection kit. After the lentivirus was transfected into Neuro 2a cells, apoptosis was induced in both the transfected and untransfected cells by staurosporine. Cell apoptosis was assessed by flow cvtometrv.MAIN OUTCOME MEASURES: Caspase 3 mRNA expression was measured by RT-PCR and Caspase protein expression was assessed by Western blot. Cellular apoptosis was determined by flow cytometry using Annevin V-PE/Taad-Cy7. RESULTS: The transfection rate of caspase 3 shRNA was 〉 98% using the lentiviral vector, RT-PCR and Western blot results demonstrated that significantly reduced Caspase 3 mRNA and protein expression in the transfected Neuro 2a. The control group exhibited 38.7% Annexin V/7aad-positive cells, which suggested apoptotic anaphase, while only 5.0% cells in the Caspase 3 gene silencing group entered apoptotic anaphase. CONCKUSION: Caspase 3 shRNA inhibited Caspase 3 expression in Neuro 2a ceils and decreased drug-induced apoptosis of Neuro 2a cells.