ABSTRACT
Aim To investigate the neuroprotective effects of puerarin on H2O2-induced SH-SY5Y cell ap-optosis and the molecular mechanisms underlying the neuroprotective effects. Methods Neuron injury mod-el was established in vitro through H2O2-induced SH-SY5Y injury. MTT assay was performed to detect the effect of puerarin on H2O2-induced SH-SY5Y survival rates. Hoechst 33342 staining was used to observe the cell apoptosis. JC-1 staining was employed to detect the level of mitochondria membrane poential. Caspase-3 was determined by caspase-3 catalyze the substrate specificity Ac-DEVD-pNA. Caspase-9 was determined by caspase-9 catalyze the substrate specificity Ac-LE-HD-pNA. The effects of puerarin on the protein level of Bcl-2,Bax,p-Akt and Akt were determined by West-ern blot. Results The cell survival rate significantly increased after puerarin pretreatment compared with H2O2model group. Furthermore, puerarin pretreat-ment not only inhibited the decreasing of mitochondrial membrane potential,increasing of caspase-3, caspase-9 enzymatic activity and the expression of Bax,but also promoted the expression of p-Akt and Bcl-2, which was prevented by LY294002, an inhibitor of PI3K/Akt. Conclusion Puerarin can play a neuroprotective role for SH-SY5Y cell apoptosis induced by H2O2, maybe via activating PI3K/Akt signaling pathway.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the transduction efficiency of serotype 1, 2, 5, 6, 7, 8, 9, 10 recombinant adeno-associated viruses (rAAV) in human lung cancer cell line A549 cells and compare the transduction efficiency of conventional AAV vectors with that of self-complementary AAV (scAAV) vectors. Furthermore, the capacity of A549 cells expressing transgenic CD40L to stimulate dendritic cells (DCs) was evaluated.</p><p><b>METHODS</b>Lung cancer A549 cells were infected with 1 x 10(4) particules per cell of AAV encoding the green fluorescent protein (GFP) or human CD40L driven by CMV promotor, and transgene expression was analyzed by flow cytometry and fluorescence microscopy. Stimulation of isolated human dendritic cells by CD40L-expressing tumor cells was quantified by measuring secreted interleukin-12 with immunoassay.</p><p><b>RESULTS</b>Serotype AAV2/5 transduced A549 cells much more efficiently than serotypes AAV2/1, AAV2/2, AAV2/6, AAV2/7, AAV2/8, AAV2/9 and AAV2/10. The transduction efficiency of scAAV2/5 was significantly higher than that of conventional AAV2/5. Furthermore, pre-treatment with carboplatin substantially increased AAV-mediated transgene expression. The scAAV2/5 vectors encoding human CD40L was used to generate CD40L. A549 cells transduce by these vectors were co-cultured with immature human DCs. As a consequence, interleukin-12 was released and measured in the culture supernatant. Specificity of immunostimulatory effect of CD40L was confirmed by blocking with a monoclonal antibody binding to human CD40L.</p><p><b>CONCLUSION</b>scAAV2/5 transduce lung adenocarcinoma A549 cell efficiently, and co-administration of chemotherapeutic agent carboplatin further enhances its transduction efficiency. It is confirmed that lung cancer cells infected with a CD40L-encoding scAAV2/5 construct can activate human DCs to secrete interleukin-12. Our findings provided a basis for future immunotherapeutic approaches including intratumoral transfer of stimulating factors.</p>