[Effect of adenovirus-mediated shRNA down-regulates SHP2 expression on the apoptosis of human hepatic stellate cells LX-2].

Objective: To investigate the effect of adenovirus-mediated short hairpin RNA (shRNA) downregulating SH2 domain-containing protein tyrosine phosphatase 2 (SHP2) on the apoptosis of human hepatic stellate cells LX-2 cultured in vitro. Methods: The recombinant adenovirus Ad-shRNA/SHP2 carrying shRNA targeted SHP2 and expressing green fluorescent protein (GFP), and the empty control virus Ad-GFP expressing GFP were transfected into LX-2 cells cultured in vitro. Real-time fluorescence quantitative PCR was used to detect SHP2 mRNA expression in LX-2 cells. Western blot was used to detect the protein expressions of SHP2, Bax, and Bcl-2 in LX-2 cells. TUNEL and annexin-V/propidium iodide dual-labeled flow cytometry were used to detect apoptosis in LX-2 cells. Experimental group: (1) Control group: LX-2 cells were transfected with DMEM instead of adenovirus; (2) Ad-GFP group: transfected with empty virus Ad-GFP; (3) Ad-shRNA/SHP2 group: transfected with recombinant adenovirus Ad-shRNA/SHP2. The means between multiple groups were compared using a one-way ANOVA and the LSD test was used for inter group comparisons. Results: shRNA-targeted SHP2 significantly down-regulated the expression of SHP2 protein and mRNA in LX-2 cells (P < 0.05). The TUNEL and annexin-V/propidium iodide dual-labeled flow cytometry results showed that the apoptosis rate of LX-2 cells in the Ad-shRNA/SHP2 group (12.755%±1.606%, 19.340%±2.505%) (P < 0.05) was significantly higher compared to the control group (3.077%±0.731%, 9.438%±0.804%) and the Ad-GFP group (3.250%±0.851%, 8.893%±1.982%), with no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). Western blot analysis of Bax and Bcl-2 protein expression in LX-2 cells of each group revealed that the Bax protein expression was significantly higher in the Ad shRNA/SHP2 group (2.493 ± 0.203) (P < 0.05) compared to the control group and Ad-GFP group (1.989 ± 0.147, 1.999 ± 0.162), with no statistically significant difference between the control group and the Ad-GFP group (P > 0.05), while the Bcl-2 protein was significantly decreased in the Ad-shRNA/SHP2 group (1.042±0.148) compared with the control group and the Ad-GFP group (1.707±0.146, 1.521±0.142), with no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). Conclusions: SHP2 expression down-regulation induces apoptosis of human hepatic stellate cells LX-2 in vitro by reducing Bcl-2/Bax.

[Effects of adenovirus-mediated shRNA down-regulates PTEN expression on fibril-binding proteins vinculin, filamin A and cortactin in activated hepatic stellate cells].

Objective: To investigate the effect of adenovirus-mediated shRNA down-regulating phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression on vinculin, filamin A, and cortactin in activated hepatic stellate cells (HSCs). Methods: Activated rats hepatic stellate cell line (HSC-T6) was cultured in vitro. Recombinant adenovirus Ad-shRNA/PTEN carrying PTEN targeted RNA interference sequence [short hairpin RNA (shRNA)] and empty control virus Ad-GFP were transfected into HSCs. The PTEN mRNA and protein expression of HSCs in each group were detected by real-time fluorescence quantitative PCR and Western blot. The expressional change of vinculin, filamin A and cortactin in HSCs of each group were detected by confocal laser scanning immunofluorescence microscope. Image-pro plus 6.0 software was used for image analysis and processing. The integrated optical density (IOD) of the fluorescence protein expression was measured. The experiment was divided into three groups: control group (DMEM instead of adenovirus solution in the adenovirus transfection step), Ad-GFP group (transfected with empty virus Ad-GFP only expressing green fluorescent protein), and Ad-shRNA/PTEN group (recombinant adenovirus Ad-shRNA/PTEN carrying shRNA targeting PTEN and expressing green fluorescent protein). One-way analysis of variance was used for comparison of mean value among the three groups, and LSD-test was used for comparison between the groups. Results: shRNA targeted PTEN was successfully transfected and the expression of PTEN mRNA and protein in HSC (P < 0.05) was significantly down-regulated. HSCs vinculin was mainly expressed in the cytoplasm. HSCs vinculin fluorescence IOD in the Ad-shRNA/PTEN group (19 758.83 ± 1 520.60) was higher than control (7 737.16 ± 279.93) and Ad-GFP group (7 725.50 ± 373.03) (P < 0.05), but there was no statistically significant difference between control group and Ad-GFP group (P > 0.05). There was no statistically significant difference in the fluorescence IOD of Filamin A among the three groups (P > 0.05), but the subcellular distribution of Filamin A among the three groups were changed. Filamin A in the Ad-shrNA /PTEN HSC group was mainly distributed in the cytoplasm. Filamin A HSC was mainly located in the nucleus.The filamin A HSC in the control group and Ad-GFP group was mainly located in the nucleus. The nucleocytoplasmic ratio of Filamin A in the AD-shrNA /PTEN group (0.60 ± 0.15) was significantly lower than control group (1.20 ± 0.15) and Ad-GFP group (1.08 ± 0.23), P < 0.05. but there was no statistically significant difference in filamin A nucleocytoplasmic ratio of HSC between the control group and the Ad-GFP group (P > 0.05). Cortactin HSCs in the three groups was mainly distributed in the cytoplasm. The cortactin fluorescence IOD of HSCs in the Ad-shRNA/PTEN group was significantly higher than control group (22 959.94 ± 1 710.42) and the Ad-GFP group (22 547.11 ± 1 588.72 ) (P < 0.05), while there was no statistically significant difference in the IOD of cortactin fluorescence in HSCs between the control group and the Ad-GFP group (P > 0.05). Conclusion: The down-regulation of PTEN expression raises the expression of microfilament-binding protein vinculin and cortactin, and changes the subcellular distribution of another microfilament binding protein filamin A, that is, translocation from nucleus to the cytoplasm in activated HSC in vitro.

[Dynamic expression of protein tyrosine phosphatase SHP2 in liver tissue of rats with carbon tetrachloride-induced liver fibrosis].

Objective: To investigate the dynamic expression of protein tyrosine phosphatase SHP2 in liver tissue of rats with carbon tetrachloride (CCl(4))-induced liver fibrosis. Methods: Rat liver fibrosis model was established by intraperitoneal injection of CCl(4). Rat liver tissue histopathological changes were detected by HE and Masson-trichrome staining. Immunohistochemical staining, Western blot and real-time fluorescent quantitative PCR were used to detect SHP2 protein and mRNA expression in rat liver tissue. One-way analysis of variance was used for the comparison of means between multiple groups, and the LSD test was used for further inter-group comparison. Results: CCl(4)-induced rat liver fibrosis model was successfully constructed, and with the extension of modeling time, the degree of liver fibrosis in rats were aggravated gradually. Immunohistochemical staining results showed that SHP2 was mainly expressed in the cytoplasm of rat liver tissues. With the aggravation of liver fibrosis, the number of cells with positive expression of SHP2 was aggravated gradually (P < 0.05). Western blot and real-time fluorescent quantitative PCR results showed that the expressions of SHP2 protein and mRNA in rat fibrotic liver tissues at different times in week 2, 4, 6, and 8 were higher in modeling than control group (P < 0.05), and was aggravated gradually with the liver fibrosis aggravation (P < 0.05). Conclusion: The expression of SHP2 protein and mRNA in the liver tissue of rats with CCl(4)-induced liver fibrosis increased gradually with the degree of liver fibrosis, and the degree of increase was consistent with the degree of liver fibrosis.

[Effect of downregulation of phosphatase and tensin homolog gene expression on p130crk- related substrate protein and paxillin signal transduction in activated hepatic stellate cells in vitro].

Objective: To investigate the role of adenovirus-mediated short hairpin RNA (shRNA) in down-regulating the expression of phosphatase and tensin homologue deleted on chromosome ten (PTEN) on p130Crk-related substrates(p130Cas) and paxillin signal transduction to activate hepatic stellate cell (HSC) in vitro. Methods: The rat hepatic stellate cell line, HSC-T6 was cultured and activated in vitro. The adenovirus was used as a vector to transiently transfect shRNA targeting PTEN to activate HSC in vitro, and then PTEN low expression model of activated HSC in vitro was established. Western blot and real-time fluorescence quantitative PCR were used to detect the protein and mRNA expression of PTEN, p130cas and paxillin in activated HSC. The experiment was divided into control group (HSC were transfected with DMEM medium instead of adenovirus), Ad-GFP group (HSC were infected with empty the adenovirus expressing green fluorescent protein (GFP) alone), and Ad-shRNA/PTEN group (HSC were infected with the recombinant adenovirus containing both shRNA targeting PTEN and GFP gene). One-way analysis of variance was used for comparison of multiple groups, and LSD test was used for inter-group comparison. Results: shRNA targeting PTEN was successfully transfected and significantly down-regulated the PTEN protein and mRNA expression of HSC in vitro (P < 0.05), and the PTEN low expression model of HSC in vitro was successfully constructed. Compared with the expression of p130cas mRNA in the three groups of HSC, the expression fold of p130cas mRNA in the Ad-GFP group and the Ad-shRNA / PTEN group was 1.01 times and 1.52 times, respectively. The expression of p130cas mRNA in HSC of the Ad-shRNA / PTEN group was significantly higher than control group and Ad-GFP group (P < 0.05), but there was no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). The expression of p130cas protein in the three groups was higher than that in the control group (0.74 ± 0.07) and the Ad-GFP group (0.72 ± 0.02); P < 0.05, but there was no statistically significant difference between the Ad-GFP group and the control group (P > 0.05). The expression of paxillin mRNA in the three groups of HSCs was compared with the expression of paxillin mRNA in the control group of HSC being 1, the expression folds of paxillin mRNA in the Ad-GFP group and Ad-shRNA / PTEN group were 0.97 times and 1.58 times, respectively. The expression of paxillin mRNA in the Ad-shRNA / PTEN group was higher than that in the control group and the Ad-GFP group (P < 0.05), and there was no statistically significant difference between the control group and the Ad-GFP group (P > 0.05). The expression of paxillin protein in the three groups of HSCs was higher in the Ad-shRNA / PTEN group (0.91 ± 0.05) than control group (0.46 ± 0.03) and Ad-GFP group (0.50 ± 0.04), P < 0.05, and there was no statistically significant difference between the Ad-GFP group and the control group (P > 0.05). Conclusion: Down-regulation of PTEN expression can significantly boost p130cas and signal transduction activity of paxillin protein in activated HSC in vitro.

[Expression of hypoxia-inducible factor 1α, glucose transporter 1 and lactate dehydrogenase 5 in colorectal cancer and clinicopathologic significance].

Objective: To investigate the expression and clinicopathological significance of hypoxia-inducible factor 1 alpha (HIF-1α), glucose transporter 1(GLUT-1) and lactate dehydrogenase(LDH)-5 in colorectal cancer. Methods: The expression levels of HIF-1α, GLUT-1 and LDH-5 were detected by immunohistochemical staining in 142 specimens of human carcinoma in comparison with adjacent normal tissues. Results: The expression levels of HIF-1α(78.2%, 111/142), GLUT-1(75.4%, 107/142) and LDH-5(68.3%, 97/142) were higher in tumor tissues than in adjacent normal tissues(14.8%, 21/142; 11.3%, 16/142; 7.0%, 10/142; P<0.01 for all three proteins), and such over-expression was significantly associated with lymphovascular invasion, tumor grade and pathological stages(all P<0.01). Additional studies showed that HIF-1α, GLUT-1 and LDH-5 were positively associated with each other(r<0.3, P<0.05 for all three proteins). Conclusion: The data suggest that HIF-1α, GLUT-1 and LDH-5 expression may serve as prognostic indicators for colorectal cancer patients.

[Effects of wild-type PTEN overexpression and its mutation on F-actin in activated hepatic stellate cells].

Objective: To investigate the effect of overexpression of wild-type phosphatase and tensin homolog (PTEN) deleted on chromosome 10 and its mutant G129E (exhibiting the activity of protein phosphatase and losing the activity of lipid phosphatase) on F-actin in activated hepatic stellate cells (HSCs) cultured in vitro. Methods: The activated hepatic stellate cell-T6 (HSC-T6) cells were cultured in vitro, and activated HSCs were transfected with adenovirus that carried wild-type PTEN gene and G129E gene using transient transfection. The HSCs were divided into the following groups: control group, which was transfected with DMEM medium instead of virus solution; Ad-GFP group, which was transfected with the empty adenovirus vector with the expression of green fluorescent protein (GFP); Ad-PTEN group, which was transfected with the recombinant adenovirus with wild-type PTEN gene and GFP expression; Ad-G129E group, which was transfected with the recombinant adenovirus with G129E gene and GFP expression. Western blot and quantitative real-time PCR were used to measure the protein and mRNA expression of PTEN in activated HSCs; under a laser scanning confocal microscope (LSCM), phalloidine labeled with the fluorescein tetramethylrhodamine isothiocyanate (TRITC) was used to observe the morphology of HSCs, distribution and fluorescence intensity of F-actin, and changes in pseudopodia and stress fibers, and a calcium fluorescence probe (Rhod-2/AM) was used to measure the changes in Ca(2+) concentration in HSCs. A one-way analysis of variance was used for comparison between multiple groups, and the least significant difference test was used for comparison between two groups. Results: Wild-type PTEN and G129E genes were highly expressed in activated HSCs. In the control group and the Ad-GFP group, HSCs had a starlike or polygonal shape, F-actin was reconfigured and formed a large number of stress fibers which stretched across the whole cell, and layered pseudopodia were seen around the cell. In the Ad-PTEN group and the Ad-G129E group, the HSCs had a fusiform shape, F-actin was mainly seen around the cell, a small number of stress fibers were seen inside the cell, and layered pseudopodia around the cell disappeared. The Ad-PTEN group and the Ad-G129E group had significant reductions in the fluorescence intensity of F-actin compared with the control group and the Ad-GFP group (357.67±13.39/377.25±14.55 vs 961.87±27.33/954.68±20.71, F = 1783.486, P < 0.05), while there were no significant differences between the Ad-PTEN group and the Ad-G129E group, as well as between the control group and the Ad-GFP group (P > 0.05). The Ad-PTEN group and the Ad-G129E group had significant reductions in the relative concentration of Ca(2+) compared with the control group and the Ad-GFP group (251.60±90.88/352.18±146.01 vs 1953.95±132.99/1937.57±115.17, F = 834.988, P < 0.05), while there were no significant differences between the Ad-PTEN group and the Ad-G129E group, as well as between the control group and the Ad-GFP group (P > 0.05). Conclusion: The overexpressed wild-type PTEN and its mutant G129E can significantly inhibit the formation and reconfiguration of cytoskeletal protein F-actin and reduce the concentration of Ca2+ in activated HSCs in vitro. In addition, there are no significant differences in the above effects between wild-type PTEN and G129E.