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Objective:To study the expression of micro RNA-155(miR-155) and IFN-γ in lung tissue in a neonatal rat model of acute respiratory distress syndrome(ARDS)lung injury by intraperitoneal injection of lipopolysaccharide(LPS).Methods:Eighty neonatal SD rats on the 7th day after birth were assigned to the experimental group(LPS group)and control group(isotonic NaCl group), with 40 rats in each group.LPS solution(4 mg/kg)was injected into the abdominal cavity of neonatal SD rats in the experimental group to establish an animal model of neonatal acute respiratory distress syndrome(NARDS). The control group was established by isotonic NaCl solution(4 ml/kg)in the same way.The lung tissue samples were taken at 3 h, 6 h, 12 h and 24 h after drug administration to observe the surface changes.Then the lung sections were stained with HE to observe the pathological changes and score the lung tissue injury.Finally, the expression levels of miR-155 and IFN-γ in the lung tissue were tested by RT-PCR and ELISA techniques, respectively.Results:(1)At the beginning of the experiment, the neonatal rats in the experimental group gradually showed the clinical manifestations of ARDS, and the macroscopic observation, pathological changes and lung tissue injury scores of the lung tissues suggested the appearance of NARDS lung injury, indicating that the model was successful.(2)The expression levels of miR-155(1.33±0.12 vs 0.95±0.02、1.77±0.17 vs 0.96±0.01、2.18±0.09 vs 0.96±0.02 and 2.43±0.06 vs 0.96±0.02)and IFN-γ(370.79±13.89 vs 273.03±11.44、424.24±10.11vs270.70±13.05、466.63±6.57 vs 268.11±7.88 and 519.13±7.09 vs 272.97±12.54)ng/L in the lung tissue of rats between the experimental group and the control group were significantly different( P<0.01), and the difference was statistically significant among the groups in the experimental group( F values were 165.983 and 408.574, P<0.01). The expression levels of miR-155 and IFN-γ in the lung tissue of the experimental group increased gradually over time and showed an increasing trend. Conclusion:After the successful establishment of NARDS animal model, the expression levels of miR-155 and IFN-γ in the lung tissue of NARDS rats have significantly increased and showed a sequential pattern.MiR-155 is expected to become an early biomarker for the diagnosis of NARDS.
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Objective@#To analyze the biological effects of miRNA-155 in the cardiac myocyte apoptosis.@*Methods@#The mouse-derived macrophage cell line RAW264.7 was treated by different concentration or different stage of oxidized low density lipoprotein (ox-LDL), and transfected by miR-155 mimic (M group), miR-155 mimics-NC (M-NC group), miR-155 inhibitor (I group) or miR-155 inhibitor-NC (I-NC group), respectively. The cell viability was measured by CCK-8 assay, cell apopotosis was measured by TUNEL and flow cytometry.@*Results@#The ox-LDL induced cell viability of Raw264.7 cells decreased and the expression of miR-155 increased in dose and time dependent manner, after treatment with different concentration of ox-LDL (10, 20, 40, 80, 160 mg/L) or 80 mg/L of ox-LDL with different stage (6, 12, 24, 48, 72 h). The expression of miR-155 increased significantly. Raw264.7 cell viability decreased significantly, compared to that of the blank control. The difference between two groups had statistical significance (P<0.05). The cell viability in M group was significantly higher than that in M-NC group, in I group was significantly higher than that in I-NC group, and the difference between two groups was statistical significance (P<0.05). Compared to that in the M-NC group, the cell apoptosis rate in M group was significantly increased (P<0.05), compared to that in the I-NC group, the cell apoptosis rate in I group were significantly decreased (P<0.05).@*Conclusions@#miR-155 can enhance the Raw264.7 cell apoptosis induced by ox-LDL.
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Objective To analyze the biological effects of miRNA-155 in the cardiac myocyte apoptosis. Methods The mouse-derived macrophage cell line RAW264.7 was treated by different concentration or different stage of oxidized low density lipoprotein (ox-LDL), and transfected by miR-155 mimic (M group), miR-155 mimics-NC (M-NC group), miR-155 inhibitor (I group) or miR-155 inhibitor-NC (I-NC group), respectively. The cell viability was measured by CCK-8 assay, cell apopotosis was measured by TUNEL and flow cytometry. Results The ox-LDL induced cell viability of Raw264.7 cells decreased and the expression of miR-155 increased in dose and time dependent manner, after treatment with different concentration of ox-LDL (10, 20, 40, 80, 160 mg/L) or 80 mg/L of ox-LDL with different stage (6, 12, 24, 48, 72 h). The expression of miR-155 increased significantly. Raw264.7 cell viability decreased significantly, compared to that of the blank control. The difference between two groups had statistical significance (P＜0.05). The cell viability in M group was significantly higher than that in M-NC group, in I group was significantly higher than that in I-NC group, and the difference between two groups was statistical significance (P＜0.05). Compared to that in the M-NC group, the cell apoptosis rate in M group was significantly increased (P＜0.05), compared to that in the I-NC group, the cell apoptosis rate in I group were significantly decreased (P＜0.05). Conclusions miR-155 can enhance the Raw264.7 cell apoptosis induced by ox-LDL.
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Objective@#To construct the mmu-miR-155 eukaryotic overexpression vector pmR-155 and to investigate its effect on HBV replication and expression of PTEN in vivo.@*Methods@#The mmu-mir-146a precursor gene fragment pre-mmu-mir-146a was amplified by PCR, then connected to the pmR-mCherry plasmid vector after double enzyme digestion, the accuracy of recombinant vector was verified by colony PCR、double enzyme digestion and sequencing; then the recombinant vector was transfected HBV transgene mice(Experimental Group)with hydrodynamics-based injection via vena caudalis, and pmR-mCherry plasmid、PBS were respectively transfected into the mice as Empty plasmid Group、Blank Group. The concentration of IFN-γ in the serum was detected by ELISA. The expression of SOCS1、PTEN mRNA in the liver was detected by qPCR at 30d post-transfectioned. The Western blot was performed to detect the changes in SOCS1、PTEN、HBX in the liver tissue at 30 d post-transfectioned. The results were analyzed with Student’s t-test, or one-way analysis of variance and the least significant difference test.@*Results@#the colony PCR、double enzyme digestion and sequencing verified that the gene was inserted into the pmR-mCherry vector. Compared with Blank Group, the expression of miR-155 in the Experimental Group was significantly increased(t = 8.90, P < 0.01); the concentration of IFN-γ in the Experimental Group was significantly increased(F = 26.58, P < 0.01); the mRNA(FSOCS1 mRNA = 19.72, P < 0.01; FPTEN mRNA = 7.38, P < 0.05) and protein(FSOCS1 = 50.30, P < 0.01; FPTEN = 129.00, P < 0.01) expression of COCS1、PTEN was significantly decreased in the Experimental group and the protein of HBX was also significantly(FHBX = 77.97, P < 0.01).@*Conclusion@#The pmR-155 eukaryotic overexpression vector is successfully constructed, this recombinant vector can express miR-155 stably; miR-155 can down-regulate cocs1、PTEN gene expression and up-regulate the expression of IFN-γ, it can inhibit the replication of HBV and a potential targets to treating hepatocellular carcinoma.
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Objective:To study the expression level of peripheral blood mircoRNA-155 and the variation characteristics of CD4+T cell percentage and to expound the clinical significance of mircoRNA-155 quantitative test and CD 4+T cell percentage cytological test.Methods:Fluorescent quantitative PCR had been used to detect the expression level of mircoRNA -155 in the peripheral blood.Flow cytometry had been used to detect the cell percentage of the peripheral blood T lymphocyte subset CD 3+T cell,CD4+T cell and CD8+T cell.The mircoRNA-155 expression levels and the cell percentages of CD 4+T were tested respectively in the selected 40 patients with atopic dermatitis ,30 patients with skin eczema and 30 healthy controls.Finally,the differences of the above groups were counted and analyzed .Results:The relative expression levels of mircoRNA-155 of the atopic dermatitis group were higher than those of the eczema group and the normal control group ( P<0.05 ).The CD4+T cell percentage of the atopic dermatitis group was higher than those of the eczema group and the normal control group ( P<0.05 ) .Conclusion: The expression level of the peripheral blood mircoRNA-155 in the patients with atopic dermatitis is increased significantly and CD 4+T cell percentage in the patients is raised as well.Consequently ,the clinical detection of miRNA-155 and CD4+T cell shall be of great significance .