SO2 is very rapidly hydrated to sulfurous acid in water solution at pH value above 6.0, whereby sulfite is yielded from the disassociation of protons. We aimed to improve the sulfite transformation efficiency and prov...SO2 is very rapidly hydrated to sulfurous acid in water solution at pH value above 6.0, whereby sulfite is yielded from the disassociation of protons. We aimed to improve the sulfite transformation efficiency and provide a basis for the direct utilization of SO2 from flue gas by a microalgal suspension. Chlorella sp. XQ-20044 was cultured in a medium with 20 mmol/L sodium sulfite under different physicochemical conditions. Under light conditions, sulfite concentration in the algal suspension reduced linearly over time, and was completely converted into sulfate within 8 h. The highest sulfite transformation rate （3.25 mmol/ （L.h）） was obtained under the following conditions： 35℃, light intensity of 300 μmol/（m^2·s）, NaHCO3 concentration of 6 g/L, initial cell density （OD540） of 0.8 and pH of 9-10. There was a positive correlation between sulfite transformation rate and the growth of Chlorella, with the conditions favorable to algal growth giving better sulfite transformation. Although oxygen in the air plays a role in the transformation of SO3^2- to SO^2-, the transformation is mainly dependent on the metabolic activity of algal cells. Chlorella sp. XQ-20044 is capable of tolerating high sulfite concentration, and can utilize sulfite as the sole sulfur source for maintaining healthy growth. We found that sulfite 〈20 mmol/L had no obvious effect on the total lipid content and fatty acid profiles of the algae, Thus, the results suggest it is feasible to use flue gas for the mass production of feedstock for biodiesel using Chlorella sp. XQ-20044, without preliminary removal of SO2, assuming there is adequate control of the pH.展开更多
Objective:The development of gene carriers for efficient gene delivery into cells has attracted growing attention in recent years.The aim of this study was to achieve a better outcome of AAV-293 cells transfection by ...Objective:The development of gene carriers for efficient gene delivery into cells has attracted growing attention in recent years.The aim of this study was to achieve a better outcome of AAV-293 cells transfection by plasmid DNA.Methods:We studied the optimal condition for higher efficiency of cationic lipid-mediated cell transfection.Four experimental groups were set.Plasmid DNA and liposome were mixed in each groups at different ratios(μg:μL),1:2.5,1:3.5,1:4.0 and 1:5.0,respectively.LacZ gene functioned as reporter gene,measuring the transfection efficiency of the four groups using the method of X-gal staining.Results:When the ratio was 1:3.5,the cell transfection rate was the highest.While the ratio of 1:2.5 recommended by product manual achieve the lowest transfection rate.Their difference had statistical significance.Conclusion:In order to obtain a higher transfection efficiency,optimization on conditions of the ratio of plasmid DNA to liposome is necessary in cell transfection.展开更多
Objective： The purpose of the study is to investigate the effects of up-regulation of Raf kinase inhibitor protein （RKIP） on the chemosensitivity of cervical cancer Hela cells. Methods： Eukaryotic expression plasm...Objective： The purpose of the study is to investigate the effects of up-regulation of Raf kinase inhibitor protein （RKIP） on the chemosensitivity of cervical cancer Hela cells. Methods： Eukaryotic expression plasmid pcDNA3.1（±）-ssRKIP containing human overall length RKIPcDNA was transfected into cervical cancer Hela cell by lipofectin assay, establishing a stable cell line containing a target gene by G418. Expression of RKIP in Hela cells was measured by Western blot analysis. After treatment with cisplatin of different concentrations and intervals of time, the effect of RKIP on the proliferation of Hela cells was evaluated by MTT method. The flow cytometry was used to investigate whether the RKIP could inhibit apoptosis in Hela cells induced by cisplatin. Results： The expression of RKIP in Hela cells transfected with pcDNA3.1-ssRKIP was increased obviously. After different concentrations of cisplatin treatment cells for 24, 48 and 72 h, the growth inhibition rate in Hela cells transfected with pcDNA3.1-ssRKIP was significantly higher than in control cells （P 〈 0.05）. With 5 pg/mL cisplatin treatment for 24 h, pcDNA3.1-ssRKIP-transfected Hela cells had an obviously higher percentage of apoptosis （23.2 ± 0.24）% than non-transfected cells （12.4 ± 0.31）% and empty vector-transfected cells （13.4 ± 0.47）%. Without treatment of cisplatin, the percentage of apoptosis for Hela cells transfected with pcDNA3.1-ssRKIP was （5.7 ± 0.12）%, which was still higher than those of the non-transfected cells （2.9 ± 0.21）% and empty vector-transfected cells （3 ± 0.08）%. Conclusion： Higher expres- sion of RKIP gene can improve chemosensitivitv of cervical cancer Hela cells to cisplatin.展开更多
Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports...Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports have shown that ATF5 promoted 3T3-L1 preadipocytes differentiation. In this study, we found that ATF5 was highly expressed in mature adipocytes, suggesting a potential role of ATF5 in mature adipocytes, which has not been reported previously. To understand the function of ATF5 in mature adipocytes, we knocked down the expression of ATF5 in 3T3-L1 mature adipocytes and observed decreased lipid droplets. Consistent with the in vitro experiment, the knockdown of ATF5 in white adipose tissue led to less adipose tissue and smaller adipocytes size. Further research revealed that the inhibition of ATF5 diminished the adipocytes size via the inhibition of fatty acid synthetase, stearyl coenzyme A desaturation enzyme 1, and the induction of carnitine palmitoyl transferase 1, one key enzyme of lipid metabolism. In addition, ATF5 knockdown in inguinal white adipose tissue improved whole body insulin sensitivity.Our work provides a new understanding of ATF5 function in mature adipocytes and a potential therapeutic target of diabetes.展开更多
基金Supported by the National Natural Science Foundation of China(No.CNSF31272680)the National High Technology Research and Development Program of China(No.2013AA065805)
文摘SO2 is very rapidly hydrated to sulfurous acid in water solution at pH value above 6.0, whereby sulfite is yielded from the disassociation of protons. We aimed to improve the sulfite transformation efficiency and provide a basis for the direct utilization of SO2 from flue gas by a microalgal suspension. Chlorella sp. XQ-20044 was cultured in a medium with 20 mmol/L sodium sulfite under different physicochemical conditions. Under light conditions, sulfite concentration in the algal suspension reduced linearly over time, and was completely converted into sulfate within 8 h. The highest sulfite transformation rate （3.25 mmol/ （L.h）） was obtained under the following conditions： 35℃, light intensity of 300 μmol/（m^2·s）, NaHCO3 concentration of 6 g/L, initial cell density （OD540） of 0.8 and pH of 9-10. There was a positive correlation between sulfite transformation rate and the growth of Chlorella, with the conditions favorable to algal growth giving better sulfite transformation. Although oxygen in the air plays a role in the transformation of SO3^2- to SO^2-, the transformation is mainly dependent on the metabolic activity of algal cells. Chlorella sp. XQ-20044 is capable of tolerating high sulfite concentration, and can utilize sulfite as the sole sulfur source for maintaining healthy growth. We found that sulfite 〈20 mmol/L had no obvious effect on the total lipid content and fatty acid profiles of the algae, Thus, the results suggest it is feasible to use flue gas for the mass production of feedstock for biodiesel using Chlorella sp. XQ-20044, without preliminary removal of SO2, assuming there is adequate control of the pH.
文摘Objective:The development of gene carriers for efficient gene delivery into cells has attracted growing attention in recent years.The aim of this study was to achieve a better outcome of AAV-293 cells transfection by plasmid DNA.Methods:We studied the optimal condition for higher efficiency of cationic lipid-mediated cell transfection.Four experimental groups were set.Plasmid DNA and liposome were mixed in each groups at different ratios(μg:μL),1:2.5,1:3.5,1:4.0 and 1:5.0,respectively.LacZ gene functioned as reporter gene,measuring the transfection efficiency of the four groups using the method of X-gal staining.Results:When the ratio was 1:3.5,the cell transfection rate was the highest.While the ratio of 1:2.5 recommended by product manual achieve the lowest transfection rate.Their difference had statistical significance.Conclusion:In order to obtain a higher transfection efficiency,optimization on conditions of the ratio of plasmid DNA to liposome is necessary in cell transfection.
基金Supported by a grant from the Qingdao Public Sphere Sci-technical Support Project(No.09-1-1-13-nsh)
文摘Objective： The purpose of the study is to investigate the effects of up-regulation of Raf kinase inhibitor protein （RKIP） on the chemosensitivity of cervical cancer Hela cells. Methods： Eukaryotic expression plasmid pcDNA3.1（±）-ssRKIP containing human overall length RKIPcDNA was transfected into cervical cancer Hela cell by lipofectin assay, establishing a stable cell line containing a target gene by G418. Expression of RKIP in Hela cells was measured by Western blot analysis. After treatment with cisplatin of different concentrations and intervals of time, the effect of RKIP on the proliferation of Hela cells was evaluated by MTT method. The flow cytometry was used to investigate whether the RKIP could inhibit apoptosis in Hela cells induced by cisplatin. Results： The expression of RKIP in Hela cells transfected with pcDNA3.1-ssRKIP was increased obviously. After different concentrations of cisplatin treatment cells for 24, 48 and 72 h, the growth inhibition rate in Hela cells transfected with pcDNA3.1-ssRKIP was significantly higher than in control cells （P 〈 0.05）. With 5 pg/mL cisplatin treatment for 24 h, pcDNA3.1-ssRKIP-transfected Hela cells had an obviously higher percentage of apoptosis （23.2 ± 0.24）% than non-transfected cells （12.4 ± 0.31）% and empty vector-transfected cells （13.4 ± 0.47）%. Without treatment of cisplatin, the percentage of apoptosis for Hela cells transfected with pcDNA3.1-ssRKIP was （5.7 ± 0.12）%, which was still higher than those of the non-transfected cells （2.9 ± 0.21）% and empty vector-transfected cells （3 ± 0.08）%. Conclusion： Higher expres- sion of RKIP gene can improve chemosensitivitv of cervical cancer Hela cells to cisplatin.
基金supported by the National Key Basic Research Project (2013CB530601 to X. Li)the National Natural Science Foundation of China (81270954, 31571401 to X. Li)
文摘Activating transcription factor 5(ATF5) is a member of the activating transcription factor/cA MP response element binding protein(ATF/CREB) family, and is highly expressed in liver and adipose tissue. Previous reports have shown that ATF5 promoted 3T3-L1 preadipocytes differentiation. In this study, we found that ATF5 was highly expressed in mature adipocytes, suggesting a potential role of ATF5 in mature adipocytes, which has not been reported previously. To understand the function of ATF5 in mature adipocytes, we knocked down the expression of ATF5 in 3T3-L1 mature adipocytes and observed decreased lipid droplets. Consistent with the in vitro experiment, the knockdown of ATF5 in white adipose tissue led to less adipose tissue and smaller adipocytes size. Further research revealed that the inhibition of ATF5 diminished the adipocytes size via the inhibition of fatty acid synthetase, stearyl coenzyme A desaturation enzyme 1, and the induction of carnitine palmitoyl transferase 1, one key enzyme of lipid metabolism. In addition, ATF5 knockdown in inguinal white adipose tissue improved whole body insulin sensitivity.Our work provides a new understanding of ATF5 function in mature adipocytes and a potential therapeutic target of diabetes.
