A series of bifunctional catalysts composed of a component for higher alcohol synthesis （Cu-CoMn oxides, CCM） and an acidic zeolite （SAPO-34, ZSM-5, Y, MCM-41） were prepared for production of liquid hydrocarbon di...A series of bifunctional catalysts composed of a component for higher alcohol synthesis （Cu-CoMn oxides, CCM） and an acidic zeolite （SAPO-34, ZSM-5, Y, MCM-41） were prepared for production of liquid hydrocarbon directly from a bio-syngas through a one-stage pro-cess. The effects of zeolite type, zeolite content, Si/Al ratio and preparation method on catalyst texture and its reaction performance were investigated. Higher selectivities and yields of liquid products were obtained by using bifunctional catalysts. The yields of liquid hydrocarbons decreased in the order CCM-ZSM-5〉CCM-SAPO-34〉CCM-Y〉CCM-MCM-41. CCM-ZSM-5 （20wt%, Si/Al=100） prepared by coprecipitation method displayed the optimal catalytic performance with the highest CO conversion （76%） and yield of liquid products （30%）. The catalysts were characterized by N2 adsorption/desorption, NH3-TPD, XRD, and H2-TPR analysis. The results showed that higher speci c surface areas and pore volumes of bifunctional catalysts were achieved by adding zeolites into CuCoMn precursors. Medium pore dimension and moderate acidity in CCM-ZSM-5 were observed, which proba-bly resulted in its excellent reaction performance. Additionally, a higher number of weaker acid sites （weak and/or medium acid sites） were formed by increasing ZSM-5 content in CCM-ZSM-5 or decreasing Si/Al ratio in ZSM-5. It was also seen that metal dispersion was higher and reducibility of metal ions was easier on the CCM-ZSM-5 catalyst prepared by coprecipitation. The higher alcohols-to-hydrocarbon process provides a promising route to hydrocarbon fuels via higher alcohols from syngas or biobased feedstocks.展开更多
Epithelial-mesenchymal transition （EMT） is initially considered as a physiological phenomenon during the embryogenesis of mammals, as well as a basic biological event maintaining the stability of the vital body. Rec...Epithelial-mesenchymal transition （EMT） is initially considered as a physiological phenomenon during the embryogenesis of mammals, as well as a basic biological event maintaining the stability of the vital body. Recent researches indicated that EMT plays a critical role in various tumors progression, through which epithelial cancers invade and metastasize. The cell characteristics are changed during EMT, in which the cells lose cell-cell and cell-matrix interactions and apical polarity, reorganize their cytoskeleton, and become isolated, motile, as well as resistant to anoikis, then become spindle-shaped mesenchymal cells. This review lays emphasis on studying the cell morphogenesis, makers and molecular mechanism regulation about EMT, discussing the relationship between the EMT and the cancer development and metastasis.展开更多
A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The tran...A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The transient expression of PpMinE using green fluorescent protein fusion in tobacco （Nicotiana tabacum L.） indicated that the PpMinE was a chloroplast-targeted protein. Overexpression of PpMinE in Escherichia coli caused division site misplacement and minicell formation, suggesting evolutionary functional conservation of MinE during plant phylogenesis. According to the phylogenetic tree, PpMinE protein has a close relationship with the highland plants, which suggests that the transfer events of MinE gene from plastid to nucleus might have occurred before the origin of the land plants.展开更多
Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand f...Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand for forest wood and timber products. Genetic engineering approaches toward the control or management of fungal pathogens, arthropod herbivores, bacterial and viral diseases, the use of pest resistance genes, and weed competitors are being studied. Although the production of transgenic trees is relatively recent and only a few species have been successfully genetically engineered in forest tree species, very useful and valuable information is available on the application of transgenic trees. Genes involved in important agricultural traits such as herbicide resistance, insect resistance, and wood quality have been isolated and have been used to genetically engineer trees. New technologies of plant molecular biology and genomics now make it possible high-efficient genetic improvement of forest trees. Genetic engineering promises to expand greatly the potential for genetic manipulation as new genes of commercial interest are discovered and utilized. Lignification is a process essential to the nature and evolution of vascular plants that is still poorly understood, even though it has been studied for more than a century. Recent studies on mutant and transgenic plants indicate that lignification may be far more flexible than previously realized. Rines with a mutation affecting the biosynthesis of the major lignin precursor, coniferyl alcohol, show a high level of an unusual subunit, dihydroconiferyl alcohol. It is also unusual as a plant polymer in that there are no plant enzymes for its degradation. These results have significant implications regarding the tradiational definition of lignin, and highlight the need for a better understanding of the lignin precursor biosynthetic pathway. In this review, we describe the progress made recently in genetic engineering of forest tree species.展开更多
Objective Despite microRNA （miR-200b） being proved to promote the proliferation of colorectal cancer （CRC） cells, the relationship between miR-200b and epithelial-mesenchymal transition （EMT） of CRC cells remain...Objective Despite microRNA （miR-200b） being proved to promote the proliferation of colorectal cancer （CRC） cells, the relationship between miR-200b and epithelial-mesenchymal transition （EMT） of CRC cells remains poorly understood. The aim of the study was to investigate the relationship between miR-200b and EMT during CRC cell migration. Methods The effect of miR-200b on EMT-associated markers E-cadherin and vimentin was evaluated by western blot in CRC cells （SW620 and HT-29） by treatment with miR-200b mimics and inhibitors. A lucifer- ase reporter assay was employed to detect downstream targets of miR-200b. Transwell migration assays were used to detect CRC cell migration. Results Westem blots revealed that treatment with miR-200b mimics led to up-regulation of E-cadherin and down-regulation of vimentin, metalloproteinase （MMP）-9, and MMP-2, whereas treatment with miR- 200b inhibitor exhibited opposite effects on expression of E-cadherin and vimentin. Luciferase reporter assays demonstrated that RhoE （RND3） was targeted by miR-200b. Two predicted target sites of miR-200b were present in the 3＇-UTR of RhoE. Predicted target site 1 was from nucleotides 1584 to 1591, and site 2 was from nucleotides 1729 to 1735. RhoE knockdown cell lines were also established to investigate the impact of RhoE and miR-200b on EMT and cell migration. RhoE knockdown enhanced the effect of miR- 200b mimics, up-regulating E-cadherin and down-regulating vimentin. RhoE knockdown also inhibited cell migration. Furthermore, miR-200b mimic treatment further promoted the inhibitory effect of RhoE knock- down on cell migration.展开更多
The promoter is a cis-acting element in regulating gene expression. A promoterless plasmid containing UidA gene was transformed into tritordeum by barmbadment. Histochemical analysis of various tissues in transgenic t...The promoter is a cis-acting element in regulating gene expression. A promoterless plasmid containing UidA gene was transformed into tritordeum by barmbadment. Histochemical analysis of various tissues in transgenic tritordeum was carried to examine tissue-specific expression of GUS(beta-glucuronidase) activity. The pollen-specific promoter was trapped and identified successfully in a transformant line. PCR(polymerase chain reaction) method was used to isolate this pollen-specific promoter. By sequencing and analyzing the amplified fragment from PCR, a part of UidA gene and a flanking sequence were obtained. Some essential elements of plant promoters were found in the sequence. To determine the function of it, the cloned fragment was fused with UidA gene, then cloned and transformed into Triticum durum. The transgenic plant transformed by this vector showed GUS expression only in pollen. Therefore a pollen-specific promoter was isolated successfully.展开更多
AIM:To investigate the anti-oxidative and anti-fibrotic effects of aloe vera in patients with liver fibrosis.METHODS:Aloe vera high molecular weight fractions(AHM) were processed by patented hyper-dry system in combin...AIM:To investigate the anti-oxidative and anti-fibrotic effects of aloe vera in patients with liver fibrosis.METHODS:Aloe vera high molecular weight fractions(AHM) were processed by patented hyper-dry system in combination of freeze-dry technique with microwave and far infrared-ray radiation.Fifteen healthy volunteers as the control group and 40 patients were included.The patients were randomly subdivided into two equal groups:the conventional group was treated with placebo(starch),and AHM group was treated with 0.15 gm/d AHM,both for 12 consecutive weeks.The patients were investigated before and after treatment.Serum activity of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),hyaluronic acid(HA),transforming growth factor-β(TGF-β) and matrixmetalloproteinase-2(MMP-2) were determined.The reduced glutathione(GSH) and malondialdehyde(MDA) levels in liver were assayed and the expression of hepatic α-smooth muscle actin(α-SMA) was identified by immunohistochemistry.RESULTS:At the start of the study,the hematoxylin and eosin staining revealed fibro-proliferated bile ductules,thick fibrous septa and dense inflammatory cellular infiltration in the patients before treatment.The use of AHM for 12 wk significantly ameliorated the fibrosis,inhibited the inflammation,and resulted in minimal infiltration and minimal fibrosis compared to the conventional group.The enzyme activities of the liver(ALT,AST and ALP) were attenuated after treatment in both groups,and the decrease in the AHM group was more significant as compared with the conventional group.Similar to the AST,the MDA levels were significantly higher before treatment,and were attenuated after treatment in both groups.In contrast,the hepatic glutathione content in the patients were decreased significantly in the AHM group compared to the controls.The serum levels of the fibrosis markers(HA,TGF-β and MMP-2) were also reduced significantly after treatment.The expression of α-SMA was modified in patients before and after treatment as compared with the normal controls.In the conventional group,there was only thin and incomplete parenchymal α-SMA positive septum joining the thickened centrilobular veins,while in the AHM group,few α-SMA positive cells were present in sinusoid and lobule after treatment.CONCLUSION:Oral supplementation with AHM could be helpful in alleviating the fibrosis and inflammation of hepatic fibrosis patients.展开更多
This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromat...This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromatics, and the isomerization of xylenes over the SiO2-modified zeolites. Compared to the conventional HZSM-5 zeolite, the SiO2-containing zeolites considerably increased the selectivity and yield of p-xylene due to the reduction of external surface acidity and the narrowing of pore entrance. The influences of the methanol additive, reaction temperature, and types of polyols on the selectivity and yield of p-xylene were investigated in detail. Catalytic cracking of polyols with methanol significantly enhanced the production of p-xylene by the alkylation of toluene with methanol. The highest p-xylene yield of 10.9 C-mol% with a p-xylene/xylenes ratio of 91.1% was obtained over the 15wt%SiO2/HZSM-5 catalyst. The reaction pathway for the formation of p-xylene was addressed according to the study of the key reactions and the characterization of catalysts.展开更多
Transgenic plants were obtained by PEG-mediated tranfer of foreign gene into cotyledon protoplasts of Orychophragums violaceus. Systematic study was carricd out on PEG-mediatcd transformation of cotyledon protoplast u...Transgenic plants were obtained by PEG-mediated tranfer of foreign gene into cotyledon protoplasts of Orychophragums violaceus. Systematic study was carricd out on PEG-mediatcd transformation of cotyledon protoplast using transient expression system, which showed 25-30 μg of pasmid, 15% PEG and a pH value of 8.0 as the optimal parameters contributing to the highest expression level. Using these parameters, cotyledon protoplasts were isolated, treated with bacterial plasmid DNA (pBI222 with HPT as selective marker) and PEG, and cultured at a density of 5×10 4/ml.After 10-15 days,they were selected by adding 25 μg/ml hygromycine. One month later, a few calli were observed, which were then transferred onto a solid medium with 50-100 μg/ml hygromycine for proliferation. Later they were transferred successively onto differentiation and rooting media and finally hygromycineresistant whole plants were obtaincd. The plants grew well in pots and a regeneration rate of 5 ×10(-5) was achieved. Then,excised leaves of the transgenic plants were used as explants for Southern blot analysis, which confirmed the stable integration of HPT gene into the chromosomal genome of Orychophragmus violaceus The transformation frequency was 10-5.展开更多
Objective:The aim of our study was to investigate the effects of Pin1 reduction on SW620 cell proliferation and apoptosis in human colorectal carcinoma.Methods:We constructed a plasmid of RNA interfering(shRNA) for Pi...Objective:The aim of our study was to investigate the effects of Pin1 reduction on SW620 cell proliferation and apoptosis in human colorectal carcinoma.Methods:We constructed a plasmid of RNA interfering(shRNA) for Pin1 gene(pGenesl-1-Pin1),then the plasmid was transfected into colorectal carcinoma SW620 cells line by liposome mediation.The protein expression of Pin1 was tested by Western blotting.The proliferation rate was analyzed by MTT and the apoptotic rate of cells was tested by flow cytometry.In order to explain further the effect of Pin1 in SW620 cells,the protein level of Bcl-2 was analyzed by Western blotting.Results:pGenesil-1-Pin1 plasmid was successfully constructed and confirmed by sequencing.The protein relative levels of Pin1 were 0.06 ± 0.04 for the P-shRNA/SW620 cells,and 0.32 ± 0.09 for the P-Con/SW620 cells.The cell growth rate of SW620 cells was slower while the apoptotic rate was increased after transfection with pGenesil-Pin1 plasmid,and the apoptotic rate was 12.38% ± 1.55% for the P-shRNA/SW620 group.At the same time,we found that the protein expression of Bcl-2 was also reduced.The results were 0.13 ± 0.04 for the P-shRNA/SW620 cells,and 0.36 ± 0.08 for the P-Con/SW620 cells.Conclusion:Inhibited Pin1 expression may suppress the cell proliferation and promote apoptosis of colorectal carcinoma cells in vitro.展开更多
文摘A series of bifunctional catalysts composed of a component for higher alcohol synthesis （Cu-CoMn oxides, CCM） and an acidic zeolite （SAPO-34, ZSM-5, Y, MCM-41） were prepared for production of liquid hydrocarbon directly from a bio-syngas through a one-stage pro-cess. The effects of zeolite type, zeolite content, Si/Al ratio and preparation method on catalyst texture and its reaction performance were investigated. Higher selectivities and yields of liquid products were obtained by using bifunctional catalysts. The yields of liquid hydrocarbons decreased in the order CCM-ZSM-5〉CCM-SAPO-34〉CCM-Y〉CCM-MCM-41. CCM-ZSM-5 （20wt%, Si/Al=100） prepared by coprecipitation method displayed the optimal catalytic performance with the highest CO conversion （76%） and yield of liquid products （30%）. The catalysts were characterized by N2 adsorption/desorption, NH3-TPD, XRD, and H2-TPR analysis. The results showed that higher speci c surface areas and pore volumes of bifunctional catalysts were achieved by adding zeolites into CuCoMn precursors. Medium pore dimension and moderate acidity in CCM-ZSM-5 were observed, which proba-bly resulted in its excellent reaction performance. Additionally, a higher number of weaker acid sites （weak and/or medium acid sites） were formed by increasing ZSM-5 content in CCM-ZSM-5 or decreasing Si/Al ratio in ZSM-5. It was also seen that metal dispersion was higher and reducibility of metal ions was easier on the CCM-ZSM-5 catalyst prepared by coprecipitation. The higher alcohols-to-hydrocarbon process provides a promising route to hydrocarbon fuels via higher alcohols from syngas or biobased feedstocks.
基金Supported by the grants from the Natural Science Foundation of China （No. 81000998） Natural Science Foundation of Hubei Province of China （No. 2007ABA248）
文摘Epithelial-mesenchymal transition （EMT） is initially considered as a physiological phenomenon during the embryogenesis of mammals, as well as a basic biological event maintaining the stability of the vital body. Recent researches indicated that EMT plays a critical role in various tumors progression, through which epithelial cancers invade and metastasize. The cell characteristics are changed during EMT, in which the cells lose cell-cell and cell-matrix interactions and apical polarity, reorganize their cytoskeleton, and become isolated, motile, as well as resistant to anoikis, then become spindle-shaped mesenchymal cells. This review lays emphasis on studying the cell morphogenesis, makers and molecular mechanism regulation about EMT, discussing the relationship between the EMT and the cancer development and metastasis.
基金This work was supported by the National Natural Science Foundation of China (No. 30470879).
文摘A nucleus-encoded MinE gene, designated PpMinE, from Physcomitrella patens was identified using RT-PCR. The presence of both N- and C-terminal extensions in PpMinE protein suggested its cyanobacterial origin. The transient expression of PpMinE using green fluorescent protein fusion in tobacco （Nicotiana tabacum L.） indicated that the PpMinE was a chloroplast-targeted protein. Overexpression of PpMinE in Escherichia coli caused division site misplacement and minicell formation, suggesting evolutionary functional conservation of MinE during plant phylogenesis. According to the phylogenetic tree, PpMinE protein has a close relationship with the highland plants, which suggests that the transfer events of MinE gene from plastid to nucleus might have occurred before the origin of the land plants.
文摘Genetic engineering of forest tree species is regarded as a strategy to reduce worldwide pressure on natural forests, to conserve genetic resources and ameliorate stress on global climate, and to meet growing demand for forest wood and timber products. Genetic engineering approaches toward the control or management of fungal pathogens, arthropod herbivores, bacterial and viral diseases, the use of pest resistance genes, and weed competitors are being studied. Although the production of transgenic trees is relatively recent and only a few species have been successfully genetically engineered in forest tree species, very useful and valuable information is available on the application of transgenic trees. Genes involved in important agricultural traits such as herbicide resistance, insect resistance, and wood quality have been isolated and have been used to genetically engineer trees. New technologies of plant molecular biology and genomics now make it possible high-efficient genetic improvement of forest trees. Genetic engineering promises to expand greatly the potential for genetic manipulation as new genes of commercial interest are discovered and utilized. Lignification is a process essential to the nature and evolution of vascular plants that is still poorly understood, even though it has been studied for more than a century. Recent studies on mutant and transgenic plants indicate that lignification may be far more flexible than previously realized. Rines with a mutation affecting the biosynthesis of the major lignin precursor, coniferyl alcohol, show a high level of an unusual subunit, dihydroconiferyl alcohol. It is also unusual as a plant polymer in that there are no plant enzymes for its degradation. These results have significant implications regarding the tradiational definition of lignin, and highlight the need for a better understanding of the lignin precursor biosynthetic pathway. In this review, we describe the progress made recently in genetic engineering of forest tree species.
文摘Objective Despite microRNA （miR-200b） being proved to promote the proliferation of colorectal cancer （CRC） cells, the relationship between miR-200b and epithelial-mesenchymal transition （EMT） of CRC cells remains poorly understood. The aim of the study was to investigate the relationship between miR-200b and EMT during CRC cell migration. Methods The effect of miR-200b on EMT-associated markers E-cadherin and vimentin was evaluated by western blot in CRC cells （SW620 and HT-29） by treatment with miR-200b mimics and inhibitors. A lucifer- ase reporter assay was employed to detect downstream targets of miR-200b. Transwell migration assays were used to detect CRC cell migration. Results Westem blots revealed that treatment with miR-200b mimics led to up-regulation of E-cadherin and down-regulation of vimentin, metalloproteinase （MMP）-9, and MMP-2, whereas treatment with miR- 200b inhibitor exhibited opposite effects on expression of E-cadherin and vimentin. Luciferase reporter assays demonstrated that RhoE （RND3） was targeted by miR-200b. Two predicted target sites of miR-200b were present in the 3＇-UTR of RhoE. Predicted target site 1 was from nucleotides 1584 to 1591, and site 2 was from nucleotides 1729 to 1735. RhoE knockdown cell lines were also established to investigate the impact of RhoE and miR-200b on EMT and cell migration. RhoE knockdown enhanced the effect of miR- 200b mimics, up-regulating E-cadherin and down-regulating vimentin. RhoE knockdown also inhibited cell migration. Furthermore, miR-200b mimic treatment further promoted the inhibitory effect of RhoE knock- down on cell migration.
基金NSFC foundation,Guangdong Province and China Education Ministry joint production-education-research funding Program ( No. 2009B090300198)the Fundamental Research Funds for the Central Universities,HUST( No. M2009060)PhD dissertation Foundation of Huazhong University of Science & Technology
文摘The promoter is a cis-acting element in regulating gene expression. A promoterless plasmid containing UidA gene was transformed into tritordeum by barmbadment. Histochemical analysis of various tissues in transgenic tritordeum was carried to examine tissue-specific expression of GUS(beta-glucuronidase) activity. The pollen-specific promoter was trapped and identified successfully in a transformant line. PCR(polymerase chain reaction) method was used to isolate this pollen-specific promoter. By sequencing and analyzing the amplified fragment from PCR, a part of UidA gene and a flanking sequence were obtained. Some essential elements of plant promoters were found in the sequence. To determine the function of it, the cloned fragment was fused with UidA gene, then cloned and transformed into Triticum durum. The transgenic plant transformed by this vector showed GUS expression only in pollen. Therefore a pollen-specific promoter was isolated successfully.
文摘AIM:To investigate the anti-oxidative and anti-fibrotic effects of aloe vera in patients with liver fibrosis.METHODS:Aloe vera high molecular weight fractions(AHM) were processed by patented hyper-dry system in combination of freeze-dry technique with microwave and far infrared-ray radiation.Fifteen healthy volunteers as the control group and 40 patients were included.The patients were randomly subdivided into two equal groups:the conventional group was treated with placebo(starch),and AHM group was treated with 0.15 gm/d AHM,both for 12 consecutive weeks.The patients were investigated before and after treatment.Serum activity of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),hyaluronic acid(HA),transforming growth factor-β(TGF-β) and matrixmetalloproteinase-2(MMP-2) were determined.The reduced glutathione(GSH) and malondialdehyde(MDA) levels in liver were assayed and the expression of hepatic α-smooth muscle actin(α-SMA) was identified by immunohistochemistry.RESULTS:At the start of the study,the hematoxylin and eosin staining revealed fibro-proliferated bile ductules,thick fibrous septa and dense inflammatory cellular infiltration in the patients before treatment.The use of AHM for 12 wk significantly ameliorated the fibrosis,inhibited the inflammation,and resulted in minimal infiltration and minimal fibrosis compared to the conventional group.The enzyme activities of the liver(ALT,AST and ALP) were attenuated after treatment in both groups,and the decrease in the AHM group was more significant as compared with the conventional group.Similar to the AST,the MDA levels were significantly higher before treatment,and were attenuated after treatment in both groups.In contrast,the hepatic glutathione content in the patients were decreased significantly in the AHM group compared to the controls.The serum levels of the fibrosis markers(HA,TGF-β and MMP-2) were also reduced significantly after treatment.The expression of α-SMA was modified in patients before and after treatment as compared with the normal controls.In the conventional group,there was only thin and incomplete parenchymal α-SMA positive septum joining the thickened centrilobular veins,while in the AHM group,few α-SMA positive cells were present in sinusoid and lobule after treatment.CONCLUSION:Oral supplementation with AHM could be helpful in alleviating the fibrosis and inflammation of hepatic fibrosis patients.
基金supported by the National Key R&D Program of China (No.2018YFB1501404)
文摘This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromatics, and the isomerization of xylenes over the SiO2-modified zeolites. Compared to the conventional HZSM-5 zeolite, the SiO2-containing zeolites considerably increased the selectivity and yield of p-xylene due to the reduction of external surface acidity and the narrowing of pore entrance. The influences of the methanol additive, reaction temperature, and types of polyols on the selectivity and yield of p-xylene were investigated in detail. Catalytic cracking of polyols with methanol significantly enhanced the production of p-xylene by the alkylation of toluene with methanol. The highest p-xylene yield of 10.9 C-mol% with a p-xylene/xylenes ratio of 91.1% was obtained over the 15wt%SiO2/HZSM-5 catalyst. The reaction pathway for the formation of p-xylene was addressed according to the study of the key reactions and the characterization of catalysts.
文摘Transgenic plants were obtained by PEG-mediated tranfer of foreign gene into cotyledon protoplasts of Orychophragums violaceus. Systematic study was carricd out on PEG-mediatcd transformation of cotyledon protoplast using transient expression system, which showed 25-30 μg of pasmid, 15% PEG and a pH value of 8.0 as the optimal parameters contributing to the highest expression level. Using these parameters, cotyledon protoplasts were isolated, treated with bacterial plasmid DNA (pBI222 with HPT as selective marker) and PEG, and cultured at a density of 5×10 4/ml.After 10-15 days,they were selected by adding 25 μg/ml hygromycine. One month later, a few calli were observed, which were then transferred onto a solid medium with 50-100 μg/ml hygromycine for proliferation. Later they were transferred successively onto differentiation and rooting media and finally hygromycineresistant whole plants were obtaincd. The plants grew well in pots and a regeneration rate of 5 ×10(-5) was achieved. Then,excised leaves of the transgenic plants were used as explants for Southern blot analysis, which confirmed the stable integration of HPT gene into the chromosomal genome of Orychophragmus violaceus The transformation frequency was 10-5.
基金Supported by grants from the National Natural Science Foundation (No.81000948/H1606)Natural Science Foundation of Shanxi Province (No.2010011047-1)University Science Technology Development Project of Shanxi Province (No.20091013)
文摘Objective:The aim of our study was to investigate the effects of Pin1 reduction on SW620 cell proliferation and apoptosis in human colorectal carcinoma.Methods:We constructed a plasmid of RNA interfering(shRNA) for Pin1 gene(pGenesl-1-Pin1),then the plasmid was transfected into colorectal carcinoma SW620 cells line by liposome mediation.The protein expression of Pin1 was tested by Western blotting.The proliferation rate was analyzed by MTT and the apoptotic rate of cells was tested by flow cytometry.In order to explain further the effect of Pin1 in SW620 cells,the protein level of Bcl-2 was analyzed by Western blotting.Results:pGenesil-1-Pin1 plasmid was successfully constructed and confirmed by sequencing.The protein relative levels of Pin1 were 0.06 ± 0.04 for the P-shRNA/SW620 cells,and 0.32 ± 0.09 for the P-Con/SW620 cells.The cell growth rate of SW620 cells was slower while the apoptotic rate was increased after transfection with pGenesil-Pin1 plasmid,and the apoptotic rate was 12.38% ± 1.55% for the P-shRNA/SW620 group.At the same time,we found that the protein expression of Bcl-2 was also reduced.The results were 0.13 ± 0.04 for the P-shRNA/SW620 cells,and 0.36 ± 0.08 for the P-Con/SW620 cells.Conclusion:Inhibited Pin1 expression may suppress the cell proliferation and promote apoptosis of colorectal carcinoma cells in vitro.
