AIM： To explore the expression of p53, bcl-2, bax, survivin and the cell apoptosis during the development of tree shrew hepatocellular carcinoma （HCC）, the relationship between expression of these genes, its impact...AIM： To explore the expression of p53, bcl-2, bax, survivin and the cell apoptosis during the development of tree shrew hepatocellular carcinoma （HCC）, the relationship between expression of these genes, its impact on HCC development, and its relation to cell apoptosis. METHODS： Tree shrew HCC was induced with aflatoxin B1 （AFB1）, and regular biopsy of liver tissues was carried out and the biopsy tissues were collected during cancer inducement. Liver biopsy tissue and HCC tissue were collected from 35 pre-cancerous experimental animals at wk 30 and 60 and at the 30^th, 60^th, and 90^th -wk. Liver biopsy tissues were collected from 13 blank control animals at wk 30, 60, and 90. Expression of p53, bcl-2, bax, and survivin at each stage was examined by immunohistochemistry method. Apoptotic cells were detected in situ by the terminal deoxynucleotidyl transferase-mediated nick end labeling （TUNEL） technique. RESULTS： The apoptosis rate of normal hepatic cells was extremely low, whereas it increased during the formation of HCC. Expression of the apoptosis-related genes p53, bcl-2, bax, and survivin during the formation of HCC presented an increasing tendency. Expression of p53 did not noticeably relate to that of bcl-2, bax, and survivin, whereas expression of bcl-2 and bax was closely related. In HCC, p53 did not present a distinct relation to cell apoptosis, whereas its high level expression was probably related to liver cell proliferation. Survivin negatively correlated apoptosis index, and its overexpression could inhibit cell apoptosis. CONCLUSION： Apoptosis-related genes p53, bcl-2, bax, and survivin are all related to the occurrence of HCC. The anti-apoptosis effect of bcl-2 is influenced by bax, and ratio bcl/bax reflects more correctly the extent of cell apoptosis.展开更多
A vector-based RNAi expression system was developed using the Xenopus tropicalis U6 promoter, which transcribes small RNA genes by RNA polymerase Ⅲ. The system was first validated in a Xenopus laevis cell line, desig...A vector-based RNAi expression system was developed using the Xenopus tropicalis U6 promoter, which transcribes small RNA genes by RNA polymerase Ⅲ. The system was first validated in a Xenopus laevis cell line, designing a short hairpin DNA specific for the GFP gene. Co-transfection of the vector-based RNAi and the GFP gene into Xenopus XR1 cells significantly decreased the number of GFP-expressing cells and overall GFP fluorescence. Vector-based RNAi was subsequently validated in GFP transgenic Xenopus embryos. Sperm nuclei from GFP transgenic males and RNAi construct-incubated-sperm nuclei were used for fertilization, respectively. GFP mRNA and protein were reduced by -60% by RNAi in these transgenic embryos compared with the control. This transgene-driven RNAi is specific and stable in inhibiting GFP expression in the Xenopus laevis transgenic line. Gene silencing by vector-based RNAi and Xenopus transgenesis may provide an alternative for ＇repression of gene function＇ studies in vertebrate model systems.展开更多
Background: Over the past years, scientists have been working on the mechanisms of the scarless healing. The remarkable phenotypic differences between fetal and adult healing may lead us to find out their characterist...Background: Over the past years, scientists have been working on the mechanisms of the scarless healing. The remarkable phenotypic differences between fetal and adult healing may lead us to find out their characteristics in genetics, which represent potentially important mechanisms to explain the differences in the quality of wound repair observed in fetus versus adult tissues. Methods: Middle laparotomy and hysterotomy were performed on pregnant rabbits on 20-day gestation to expose the fetal back, and longitudinal incision which penetrated full skin was made on the back of fetus. The trauma fetus skin was harvested at 12 h post-operation (FT), the fetus control (FC) and trauma adult skin (AT) were taken at the same time. dscDNA was synthesized from total RNA of skin samples with SMART technology. An improved suppression subtractive hybridization (SSH) method was applied to analyze the samples. Having taken one of the three samples as Tester respectively, the other two together as Drivers, one forward and two reverse hybridization products were gotten. Having amplified by selective PCR, the products were inserted into vector, and then transferred into E.coli HB101. The colonies were screened by electrophoresis, reverse Northern afterwards, and the positive clones were sequenced. BLAST in NCBI was performed to compare and analyze the positive clones (expressed sequence Tag, ESTs). Results: Totally 298 clones were gotten and 61 positive clones were obtained after screening. The 61 selected positive clones were sequenced and 54 sequences were goten. Conclusion: Instead of traditional SSH, an improved SSH with 2 Drivers was applied in the experiment. The improved program is reasonable and correct in both theory and practice.展开更多
Objective: To explore the possibility of the transfection of MyoD gene induced bone marrow mesenchymal stem cells ( MSCs) to differentiate into myoblasts in vitro. Methods: The eukaryotic expression plasmid vector pIR...Objective: To explore the possibility of the transfection of MyoD gene induced bone marrow mesenchymal stem cells ( MSCs) to differentiate into myoblasts in vitro. Methods: The eukaryotic expression plasmid vector pIRES2-EGFP-MyoD was transfected into MSCs with lipotransfection method, and the positive cells were selected by G418; The expression of MyoD was detected in the transfected MSCs with RT-PCR and the amplified, purified product was identified by sequencing; The reporter gene enhanced green fluorescence protein ( EFGP) was observed in the transfected cells under a fluorescent and a laser confocal microscopes; Immunohistochemical methods was used to examine the expressions of MyoD, myogenin, myosin, myoglobin and desmin in the differentiated cells. The ultrastructure changes of the cells before and after transfection were observed with electron microscopy. Results: The expression of MyoD was detected in the transfected MSCs with RT-PCR and the amplified, purified product was as same in sequence as that from Genbank; Green fluorescence was observed in the transfected cells under a fluorescent and a laser confocal microscopes; Immunohistochemical methods indicated that MyoD, myogenin, myosin, myoglobin and desmin were expressed in the transfected cells; The transfected cells showed the morphological characteristics of mature cells with filaments in their cytoplasm. Conclusion: MyoD gene can induce cultured MSCs to successfully differentiate into myoblasts , probably providing an experimental foundation for trauma repair.展开更多
Objective To find the genes involved in pathogenesis of diabetic nephropathy using gene chip technology. Methods We established a type I diabetic rat model by streptozotocin injection and divided these diabetic rats i...Objective To find the genes involved in pathogenesis of diabetic nephropathy using gene chip technology. Methods We established a type I diabetic rat model by streptozotocin injection and divided these diabetic rats into two groups： diabetic rats group（ D group） and diabetic rats group treated with Astragalus Membranaceus （ DA group）. The renal tissue was collected and total RNA was extracted for gene chips. With the help of gene chip, we tried to discover the differential-displayed genes between these two groups. Results Totally 201 differential-displayed genes were found between the two groups, among which 126 genes were up-regulated and 75 genes were down-regulated in the rat renal tissue. Conclusion With gene chip results, we find several genes which are associated with diabetes in the rat renal tissue. The further research on the function of these genes will be helpful to understand the mechanism of diabetic nephropathy.展开更多
To explore the role of nuclear factor-κB(NF-κB) in the signal pathway of protein kinase C (PKC) regulating the proliferation and apoptosis of T lymphocytes in asthma. T lymphocytes were isolated from the asthmatic m...To explore the role of nuclear factor-κB(NF-κB) in the signal pathway of protein kinase C (PKC) regulating the proliferation and apoptosis of T lymphocytes in asthma. T lymphocytes were isolated from the asthmatic model of guinea pigs and the asthmatic patients. Either the T cells stimulated with PMA alone or those stimulated with PMA together with pyrrolidine dithiocarbamate (PDTC) were incubated for 1 and 24?h. The proliferation of and the presence of NF-κB in the cells incubated for 1?h were observed by MTT and immunohistochemical staining, respectively. And the cells incubated for 24?h were observed for the apoptosis by TUNEL. All the assays were paralleled with controls, and all the data were analyzedstatistically with the software SAS. The percentage of cells of nuclear positive staining of NF-κB and the proliferation of T lymphocytes from asthmatic guinea pigs and asthmatic patients stimulated with PMA were significantly higher than those of T lymphocytes from asthmatic guinea pigs and asthmatic patients stimulated without PMA respectively (P<0.01) and those of T lymphocytes from normal control guinea pigs and normal control persons stimulated with PMA respectively (P<0.01), and were significantly reduced by PDTC (P<0.01). The apoptosis index of T lymphocytes from asthmatic guinea pigs and asthmatic patients stimulated with PMA were significantly lower than those of T lymphocytes from asthmatic guinea pigs and asthmatic patients stimulated without PMA respectively (P<0.01) and those of T lymphocytes from normal control guinea pigs and normal control persons stimulated with PMA respectively (P<0.01), and were significantly induced by PDTC (P<0.01). There were good positive correlation between the percentage of cells of nuclear staining of NF-κB of T lymphocytes and the proliferation of T lymphocytes (r=0.51-0.72, P<0.001), and also good negative correlation between the percentage of cells of nuclear staining of NF-κB and the apoptosis index of T lymphocytes (r=-0.55-0.71, P<0.001, respectively). It concludes that the active PKC of asthmatic T lymphocytes promoting the proliferation and inhibiting the apoptosis of T lymphocytes may be mediated by activating NF-κB, the activation of PKC-NF-κB signal pathway of T lymphocytes NF-κB may play an important role in the pathogenesis of asthma.展开更多
To study the sequential changes of HIF 1α (hypoxia inducible factor 1 alpha) in experimental spinal cord injury in rats and to analyze its potential effects in SCI. Methods: A static compression model of SCI was empl...To study the sequential changes of HIF 1α (hypoxia inducible factor 1 alpha) in experimental spinal cord injury in rats and to analyze its potential effects in SCI. Methods: A static compression model of SCI was employed in this study. Expressions of HIF 1α were measured with immunohistochemical staining, while flow cytometry was used to determine the apoptotic ratio and bcl 2 expre ssions. Results: HIF 1α began to increase 1 day after injury, and rea ched the peak at 3 7 days. Two weeks later, it declined significantly. The sequ ential changes of HIF 1α coincided well with the alterations of apoptotic rat io and contents of bcl 2. Conclusions: HIF 1α possibly participates in the secondary is chemic and hypoxic procedures after spinal cord injury, and may mediate the trau matic apoptosis. Further understanding of HIF 1α may provide new therapeuti c regimens for SCI.展开更多
基金Supported by the Science and Technology Department of Guangxi,No. 0143058,No. 0144002The National Natural Science Foundation of China, No. 39860072
文摘AIM： To explore the expression of p53, bcl-2, bax, survivin and the cell apoptosis during the development of tree shrew hepatocellular carcinoma （HCC）, the relationship between expression of these genes, its impact on HCC development, and its relation to cell apoptosis. METHODS： Tree shrew HCC was induced with aflatoxin B1 （AFB1）, and regular biopsy of liver tissues was carried out and the biopsy tissues were collected during cancer inducement. Liver biopsy tissue and HCC tissue were collected from 35 pre-cancerous experimental animals at wk 30 and 60 and at the 30^th, 60^th, and 90^th -wk. Liver biopsy tissues were collected from 13 blank control animals at wk 30, 60, and 90. Expression of p53, bcl-2, bax, and survivin at each stage was examined by immunohistochemistry method. Apoptotic cells were detected in situ by the terminal deoxynucleotidyl transferase-mediated nick end labeling （TUNEL） technique. RESULTS： The apoptosis rate of normal hepatic cells was extremely low, whereas it increased during the formation of HCC. Expression of the apoptosis-related genes p53, bcl-2, bax, and survivin during the formation of HCC presented an increasing tendency. Expression of p53 did not noticeably relate to that of bcl-2, bax, and survivin, whereas expression of bcl-2 and bax was closely related. In HCC, p53 did not present a distinct relation to cell apoptosis, whereas its high level expression was probably related to liver cell proliferation. Survivin negatively correlated apoptosis index, and its overexpression could inhibit cell apoptosis. CONCLUSION： Apoptosis-related genes p53, bcl-2, bax, and survivin are all related to the occurrence of HCC. The anti-apoptosis effect of bcl-2 is influenced by bax, and ratio bcl/bax reflects more correctly the extent of cell apoptosis.
文摘A vector-based RNAi expression system was developed using the Xenopus tropicalis U6 promoter, which transcribes small RNA genes by RNA polymerase Ⅲ. The system was first validated in a Xenopus laevis cell line, designing a short hairpin DNA specific for the GFP gene. Co-transfection of the vector-based RNAi and the GFP gene into Xenopus XR1 cells significantly decreased the number of GFP-expressing cells and overall GFP fluorescence. Vector-based RNAi was subsequently validated in GFP transgenic Xenopus embryos. Sperm nuclei from GFP transgenic males and RNAi construct-incubated-sperm nuclei were used for fertilization, respectively. GFP mRNA and protein were reduced by -60% by RNAi in these transgenic embryos compared with the control. This transgene-driven RNAi is specific and stable in inhibiting GFP expression in the Xenopus laevis transgenic line. Gene silencing by vector-based RNAi and Xenopus transgenesis may provide an alternative for ＇repression of gene function＇ studies in vertebrate model systems.
文摘Background: Over the past years, scientists have been working on the mechanisms of the scarless healing. The remarkable phenotypic differences between fetal and adult healing may lead us to find out their characteristics in genetics, which represent potentially important mechanisms to explain the differences in the quality of wound repair observed in fetus versus adult tissues. Methods: Middle laparotomy and hysterotomy were performed on pregnant rabbits on 20-day gestation to expose the fetal back, and longitudinal incision which penetrated full skin was made on the back of fetus. The trauma fetus skin was harvested at 12 h post-operation (FT), the fetus control (FC) and trauma adult skin (AT) were taken at the same time. dscDNA was synthesized from total RNA of skin samples with SMART technology. An improved suppression subtractive hybridization (SSH) method was applied to analyze the samples. Having taken one of the three samples as Tester respectively, the other two together as Drivers, one forward and two reverse hybridization products were gotten. Having amplified by selective PCR, the products were inserted into vector, and then transferred into E.coli HB101. The colonies were screened by electrophoresis, reverse Northern afterwards, and the positive clones were sequenced. BLAST in NCBI was performed to compare and analyze the positive clones (expressed sequence Tag, ESTs). Results: Totally 298 clones were gotten and 61 positive clones were obtained after screening. The 61 selected positive clones were sequenced and 54 sequences were goten. Conclusion: Instead of traditional SSH, an improved SSH with 2 Drivers was applied in the experiment. The improved program is reasonable and correct in both theory and practice.
文摘Objective: To explore the possibility of the transfection of MyoD gene induced bone marrow mesenchymal stem cells ( MSCs) to differentiate into myoblasts in vitro. Methods: The eukaryotic expression plasmid vector pIRES2-EGFP-MyoD was transfected into MSCs with lipotransfection method, and the positive cells were selected by G418; The expression of MyoD was detected in the transfected MSCs with RT-PCR and the amplified, purified product was identified by sequencing; The reporter gene enhanced green fluorescence protein ( EFGP) was observed in the transfected cells under a fluorescent and a laser confocal microscopes; Immunohistochemical methods was used to examine the expressions of MyoD, myogenin, myosin, myoglobin and desmin in the differentiated cells. The ultrastructure changes of the cells before and after transfection were observed with electron microscopy. Results: The expression of MyoD was detected in the transfected MSCs with RT-PCR and the amplified, purified product was as same in sequence as that from Genbank; Green fluorescence was observed in the transfected cells under a fluorescent and a laser confocal microscopes; Immunohistochemical methods indicated that MyoD, myogenin, myosin, myoglobin and desmin were expressed in the transfected cells; The transfected cells showed the morphological characteristics of mature cells with filaments in their cytoplasm. Conclusion: MyoD gene can induce cultured MSCs to successfully differentiate into myoblasts , probably providing an experimental foundation for trauma repair.
基金Supported by the4th phase of Financial Foundation of Shanghai Education Committee, China (ZDXK2001)
文摘Objective To find the genes involved in pathogenesis of diabetic nephropathy using gene chip technology. Methods We established a type I diabetic rat model by streptozotocin injection and divided these diabetic rats into two groups： diabetic rats group（ D group） and diabetic rats group treated with Astragalus Membranaceus （ DA group）. The renal tissue was collected and total RNA was extracted for gene chips. With the help of gene chip, we tried to discover the differential-displayed genes between these two groups. Results Totally 201 differential-displayed genes were found between the two groups, among which 126 genes were up-regulated and 75 genes were down-regulated in the rat renal tissue. Conclusion With gene chip results, we find several genes which are associated with diabetes in the rat renal tissue. The further research on the function of these genes will be helpful to understand the mechanism of diabetic nephropathy.
文摘To explore the role of nuclear factor-κB(NF-κB) in the signal pathway of protein kinase C (PKC) regulating the proliferation and apoptosis of T lymphocytes in asthma. T lymphocytes were isolated from the asthmatic model of guinea pigs and the asthmatic patients. Either the T cells stimulated with PMA alone or those stimulated with PMA together with pyrrolidine dithiocarbamate (PDTC) were incubated for 1 and 24?h. The proliferation of and the presence of NF-κB in the cells incubated for 1?h were observed by MTT and immunohistochemical staining, respectively. And the cells incubated for 24?h were observed for the apoptosis by TUNEL. All the assays were paralleled with controls, and all the data were analyzedstatistically with the software SAS. The percentage of cells of nuclear positive staining of NF-κB and the proliferation of T lymphocytes from asthmatic guinea pigs and asthmatic patients stimulated with PMA were significantly higher than those of T lymphocytes from asthmatic guinea pigs and asthmatic patients stimulated without PMA respectively (P<0.01) and those of T lymphocytes from normal control guinea pigs and normal control persons stimulated with PMA respectively (P<0.01), and were significantly reduced by PDTC (P<0.01). The apoptosis index of T lymphocytes from asthmatic guinea pigs and asthmatic patients stimulated with PMA were significantly lower than those of T lymphocytes from asthmatic guinea pigs and asthmatic patients stimulated without PMA respectively (P<0.01) and those of T lymphocytes from normal control guinea pigs and normal control persons stimulated with PMA respectively (P<0.01), and were significantly induced by PDTC (P<0.01). There were good positive correlation between the percentage of cells of nuclear staining of NF-κB of T lymphocytes and the proliferation of T lymphocytes (r=0.51-0.72, P<0.001), and also good negative correlation between the percentage of cells of nuclear staining of NF-κB and the apoptosis index of T lymphocytes (r=-0.55-0.71, P<0.001, respectively). It concludes that the active PKC of asthmatic T lymphocytes promoting the proliferation and inhibiting the apoptosis of T lymphocytes may be mediated by activating NF-κB, the activation of PKC-NF-κB signal pathway of T lymphocytes NF-κB may play an important role in the pathogenesis of asthma.
基金ThisworkwassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina (No .3 9970 75 5 )
文摘To study the sequential changes of HIF 1α (hypoxia inducible factor 1 alpha) in experimental spinal cord injury in rats and to analyze its potential effects in SCI. Methods: A static compression model of SCI was employed in this study. Expressions of HIF 1α were measured with immunohistochemical staining, while flow cytometry was used to determine the apoptotic ratio and bcl 2 expre ssions. Results: HIF 1α began to increase 1 day after injury, and rea ched the peak at 3 7 days. Two weeks later, it declined significantly. The sequ ential changes of HIF 1α coincided well with the alterations of apoptotic rat io and contents of bcl 2. Conclusions: HIF 1α possibly participates in the secondary is chemic and hypoxic procedures after spinal cord injury, and may mediate the trau matic apoptosis. Further understanding of HIF 1α may provide new therapeuti c regimens for SCI.
