RESUMO
Resveratrol is a natural polyphenol with multiple positive biofunctions and was found to have potential as a radiosensitizer with an intricate molecular mechanism. Store-operated calcium entry (SOCE) is a novel intracellular calcium regulatory pattern that is mainly mediated by iron channels, such as by the stromal interaction molecule (STIM) and calcium release-activated calcium channel protein (Orai) families. SOCE was recently reported to be suppressed via the downregulation of STIM or Orai families for the promotion of tumor cell death induced by resveratrol. In the present study, resveratrol combined with irradiation treatment were found to induce more evident cell damage compared with irradiation treatment alone, as shown with Cell Counting Kit-8 assay and mitochondrial membrane potential detection with rhodamine 123. Additionally, resveratrol combined with irradiation treatment decreased the expression of STIM1 and Orai1, while it had no effects on STIM2, Orai2 and Orai3. Moreover, resveratrol combined with irradiation treatment lead to alleviated thapsigargin-induced SOCE. In addition, overexpression of STIM1 and Orai1 reversed resveratrol-induced SOCE inhibition and reduced death in A549 cells under irradiation. In summary, the present results revealed that resveratrol can significantly enhance the effect of irradiation damage on lung adenocarcinoma A549 cells, and this effect may be mediated by suppression of SOCE with reduced expression of both STIM1 and Orai1.
RESUMO
The purpose of this study was to evaluate the effect of dicalcium phosphate dihydrate (DCPD) on the biocompatibility of mineral trioxide aggregate (MTA). DCPD was added to MTA (OrthoMTA) to suppress the increase in pH of MTA during hardening, and the change of pH, cytotoxicity, and subcutaneous inflammation reactions in mouse model were observed. The pH of OrthoMTA and DCPD-OrthoMTA at 1st day in phosphate-buffered saline was 12.5 and 12.8, respectively. At 19th day, the pH was 11.6 (OrthoMTA) and 8.8 (DCPD-OrthoMTA). Cytotoxicity of DCPD-OrthoMTA extract was lesser than that of OrthoMTA at high concentration (above 50%) (p<0.05). No significant differences appeared in subcutaneous inflammatory reactions among ProRoot MTA, OrthoMTA and DCPD-OrthoMTA. Therefore, it is likely that there is no apparent relationship between the cytotoxicity and subcutaneous inflammation in our experimental conditions.
RESUMO
The purpose of this study was to evaluate the effect of dicalcium phosphate dihydrate (DCPD) on the biocompatibility of mineral trioxide aggregate (MTA). DCPD was added to MTA (OrthoMTA) to suppress the increase in pH of MTA during hardening, and the change of pH, cytotoxicity, and subcutaneous inflammation reactions in mouse model were observed. The pH of OrthoMTA and DCPD-OrthoMTA at 1st day in phosphate-buffered saline was 12.5 and 12.8, respectively. At 19th day, the pH was 11.6 (OrthoMTA) and 8.8 (DCPD-OrthoMTA). Cytotoxicity of DCPD-OrthoMTA extract was lesser than that of OrthoMTA at high concentration (above 50%) (p<0.05). No significant differences appeared in subcutaneous inflammatory reactions among ProRoot MTA, OrthoMTA and DCPD-OrthoMTA. Therefore, it is likely that there is no apparent relationship between the cytotoxicity and subcutaneous inflammation in our experimental conditions.
RESUMO
OBJECTIVE@#To assess the potential of transient expression of recombinant human plasminogen activator (rhPA) in plants as a cost-effective approach for recombinant rhPA production.@*METHODS@#Tobacco mosaic virus-based expression vector pTMV rhPA-NSK and plant binary expression vector pJ Zera-rhPA were constructed by sequence synthesis and subcloning. The two vectors were inoculated on either or leaves agroinfiltration. The expression of recombinant rhPA in leaves was examined using Western blotting and ELISA, and the fibrinolysis activity of plant-produced rhPA was assessed by fibrin agarose plate assay (FAPA).@*RESULTS@#Five to nine days after infiltration with an inoculum containing pTMV rhPA-NSK, necrosis appeared in the infiltrated area on the leaves of both plants, but intact recombinant rhPA was still present in the necrotic leaf tissues. The accumulation level of recombinant rhPA in infiltrated leaves was significantly higher than that in leaves ( < 0.05). The yield of recombinant rhPA was up to 0.6% of the total soluble protein (or about 60.0 μg per gram) in the fresh leaf biomass at 7 days post-inoculation. The plant-derived rhPA was bioactive to convert inactive plasminogen to active plasmin. No necrosis occurred in pJ Zera-rhPA-infiltrated leaves. The Zera-rhPA protein was partially cleaved between the site of Zera tag and rhPA sequence in both leaves. We speculated that the formation of Zera tags-induced particles in the plant cells was a dynamic process of progressive aggregation in which some of the soluble polypeptides were encapsulated in these particles.@*CONCLUSIONS@#Enzymatically active recombinant rhPA can be rapidly expressed in tobacco plants using the plant viral ampliconbased system, which offers a promising alternative for cost-effective production of recombinant rhPA.
