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Objective To evaluate the protective effect and the underlying mechanism of mesenchymal stem cell-derived extracellular vesicle (MSC-EV) on radiation-induced liver injury and liver cell line injury in mouse models. Methods C57BL/6 mice were randomly divided into the blank group, model group and MSC-EV treatment group (treatment group), with 9 mice in each group. AML12 cells were randomly divided into the control group, irradiation group and MSC-EV intervention group (intervention group). Animal and cell models with radiation-induced injury were established by one-time 15 Gy and 6 Gy X-ray irradiation, respectively. At 48 h after irradiation, liver tissues and serum samples of mice were collected and prepared for subsequent experiments. At 15 h post-irradiation, cell experiment was carried out. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and content of malondialdehyde (MDA) in liver tissues and cells were measured. The relative expression levels of interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β and CXC chemokine ligand (CXCL)10 messenger RNA (mRNA) were detected by real-time fluorescent quantitative polymerase chain reaction (RT-qPCR). Liver tissues were prepared for hematoxylin-eosin (HE) staining to calculate liver pathological injury score. The apoptosis of liver tissues and cells was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) and propidiumiodide (PI) staining, respectively. The expression levels of glutathione peroxidase 4 (GPX4) and ferroptosis suppressor protein 1 (FSP1) proteins were detected by Western blot. The production level of reactive oxygen species (ROS) was detected by dihydroethidine (DHE) staining. The fluorescence intensity of mitochondrial permeability transition pore (mPTP) was determined. Results Compared with the blank group, serum levels of AST and ALT were up-regulated, and the relative expression levels of IL-1β, TGF-β and CXCL10 mRNA in the mouse liver tissues were up-regulated, and MDA content was increased, liver injury score was elevated, cell apoptosis rate was increased, intracellular ROS level was elevated, and the relative expression levels of GPX4 and FSP1 proteins in the mouse liver tissues were down-regulated in the model group, and the differences were statistically significant (all P<0.05). Compared with the model group, serum levels of AST and ALT were decreased, and the relative expression levels of IL-1β, TGF-β and CXCL10 mRNA in the liver tissues of mice were down-regulated, MDA content was declined, liver injury score was declined, cell apoptosis rate was decreased, intracellular ROS level was decreased, and the relative expression levels of GPX4 and FSP1 proteins in the liver tissues of mice were up-regulated in the treatment group, and the differences were statistically significant (all P<0.05). Compared with the control group, cell apoptosis rate was increased, intracellular ROS level was elevated, the fluorescence intensity of mPTP was weakened, the relative expression levels of IL-1β, TGF-β and IL-6 mRNA were up-regulated, MDA content was increased, and the relative expression levels of GPX4 and FSP1 proteins were down-regulated in the irradiation group, and the differences were statistically significant (all P<0.05). Compared with the irradiation group, cell apoptosis rate was declined, intracellular ROS level was decreased, the fluorescence intensity of mPTP was strengthened, the relative expression levels of IL-1β, TGF-β and IL-6 mRNA were down-regulated, MDA content was decreased and the relative expression levels of GPX4 and FSP1 proteins were up-regulated in the intervention group, and the differences were statistically significant (all P<0.05). Conclusions MSC-EV may effectively alleviate radiation-induced liver injury by reducing ferroptosis of liver cells, enhancing antioxidant level and decreasing the production of lipid peroxide, thereby effectively alleviating radiation-induced liver injury.
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Objective To investigate the role of human umbilical cord mesenchymal stem cell-derived extracellular vesicle (hUC-MSC-EV) in the regeneration of fibrotic liver. Methods C57BL/6 mice were randomly divided into the 70% normal liver resection group (Oil+PHx group), 70% liver fibrosis resection group (CCl4+PHx group) and 70% liver fibrosis resection+mesenchymal stem cell-derived extracellular vesicle (MSC-EV) treatment group (CCl4+PHx+MSC-EV group), with 8 mice in each group. LX-2 cell lines were assigned into the phosphate buffer solution (PBS) group, transforming growth factor (TGF)-β group and TGF-β+MSC-EV group. The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in mice after partial liver resection were detected in each group. The expression levels of liver fibrosis and proliferation-related parameters were analyzed in each group. The messenger RNA (mRNA) expression levels of epidermal growth factor (EGF), fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) in LX-2 cells were detected in each group, and their effects on HGF expression in mouse liver were observed. Results Compared with the Oil+PHx group, the serum levels of AST, ALT and LDH were up-regulated, and the degree of fibrosis was more severe, the positive area of Sirius red and α-smooth muscle actin (α-SMA) staining was larger, and the expression level of α-SMA protein was up-regulated in the CCl4+PHx group. Compared with the CCl4+PHx group, the serum levels of AST, ALT and LDH were decreased, the degree of fibrosis was slighter, the positive area of Sirius red and α-SMA staining was decreased, and the expression level of α-SMA protein was down-regulated in the CCl4+PHx+MSC-EV group, and the differences were statistically significant (all P < 0.05). Compared with the Oil+PHx group, the protein expression levels of Ki67 and proliferating cell nuclear antigen (PCNA) were lower in the CCl4+PHx group. Compared with the CCl4+PHx group, the protein expression levels of Ki67 and PCNA were increased in the CCl4+PHx+MSC-EV group, and the differences were statistically significant (all P < 0.05). Compared with the PBS group, the expression level of CollagenⅠ mRNA in LX-2 cells was increased, the expression level of α-SMA protein was up-regulated and the expression level of HGF protein was decreased in the TGF-β group. Compared with the TGF-β group, the expression level of CollagenⅠ mRNA in LX-2 cells was decreased, the expression levels of HGF mRNA and protein were increased, and the expression level of α-SMA protein was decreased in the TGF-β+MSC-EV group, the differences were statistically significant (all P < 0.05). The expression level of HGF protein in the CCl4+PHx group was lower than that in the Oil+PHx group, whereas the difference was not statistically significant (P > 0.05). The expression level of HGF protein in the CCl4+PHx+MSC-EV group was higher than that in the CCl4+PHx group, and the difference was statistically significant (P < 0.05). Conclusions The regenerative capacity of fibrotic liver is weaker than that of normal liver. hUC-MSC-EV may alleviate liver fibrosis and improve liver regeneration by promoting HGF secretion from actived hepatic stellate cells and effectively enhancing the regenerative capacity of fibrotic liver.
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Purpose:The experimental study on the changes of HPV18 E6 gene,p53 mRNA and telomerase catalytic subunit (hTERT) mRNA in the process of HeLa cell apoptosis was carried out to supply a new way to diagnosing and treating cervical cancer. Methods:The apoptosis of HeLa cell was confirmed by means of electron microscope and flow cytometry. With PCR and RT PCR, we studied the changes and relations among HPV18 E6 DNA,p53 mRNA as well as hTERT mRNA in the process of HeLa cell apoptosis. Results:HPV18 E6 DNA and p53 mRNA had no changes but hTERT mRNA activation was inhibited by elemene emulsion. Conclusions:During apoptosis of HeLa cells induced by elemene emulsion, hTERT mRNA activation could apparently be inhibited. Hence, inhibition of telomerase activation may represent a new chemosensitisation for tumors resistant to anticancer drugs.