Objective To construct the recombinant plasmid pEGFP-N1-SrV+ and evaluate the expression of SrV+in mammalian 293T cells.nethods srv+.a gene encoding the vailable region of the surface protein of the Streptococcus mutans OMZ175.was cloned chemically based on its reported nucleotide sequence.The eukaryotic expression plasmid,pEGFP-N1-SrV+,was constructed by introducing the srv+ gene into the Kpn Ⅰ/Xho Ⅰ site of pEGFP-NI.The recombinant plasmid pEGFP-N1-SrV+was transfected into 293T cells with lipofectamine and the expression level of SrV+was evaluated.Results The eukaryotic expression plasmid pEGFP-N1-SrV+was constructed successfully.GFP was observed by green fluorescent microscope.and a 72 × 1 03 protein was detected bv Westem blot.Real-time RT-PCR analysis revealed that the expression of the pEGFP-N1-SrV+in 293T was excellent and significant compared the control group. Conclusion The recombinant plasmid pEGFP-N1-SrV+was successfully constructed.which could encode the expression of SrV+after transfected into the mammalian 293T Cells.

AIM: The aim of this work is to investigate the protective effects of Ginsenoside Rb 1(Rb 1) on apoptosis induced by hypoxia /hypoglycemia and reoxygenation in cultured rat hippocampal neurons. METHODS: Apoptosis were measured by flow cytometry; Morphological changes and neuronal necrosis were examined under microscope; The leakage of lactic dehydrogenase(LDH) and the product of nitric oxide(NO) were measured. RESULTS: hypoxia /hypoglycemia cultures for 5 h and reoxygenation induced neuronal apoptosis and necrosis,and significantly increased the leakage of LDH and the product of NO. The effects were enhanced with the extending time of reoxygenation. Rb 1 could significantly decrease the percentage of neuronal apoptosis and necrosis, and reduce the leakage of LDH and the product of NO. CONCLUSION: Rb 1 had an effect of anti-neuronal apoptosis. This effect might be related to the inhibition of the activity of NO synthase and NO production.

ObjectiveTo investigate the role and mechanism of endoplasmic reticulum stress in the formation of sex difference in liver diseases. MethodsA retrospective analysis was performed to investigate the sex distribution of 23 043 patients with liver diseases in the outpatient service of hepatology and 1110 patients with liver diseases in Department of Hepatology in Zunyi Medical University in 2018. A mouse model of acute liver injury was established by intraperitoneal injection of carbon tetrachloride to confirm the sex difference of liver injury and investigate the mechanism of action of endoplasmic reticulum stress in the formation of sex difference in liver injury. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. The chi-square test was used for comparison of categorical data. ResultsAmong the patients in the outpatient service and the hospitalized patients, the male patients had a significantly higher incidence rate than the female patients, with a male/female ratio of 1.56∶1 in the patients in the outpatient service and 1.86∶1 in the hospitalized patients, and there was a significant difference between the two groups of patients (χ2=7.517, P=0.003). The animal model study showed that compared with the female mice with acute liver injury induced by carbon tetrachloride, the male mice had significantly higher death rate (50% vs 30%, P＜0.05), serum levels of alanine aminotransferase (5767.8±518.8 U/L vs 4749.5±378.0 U/L, P＜0.05) and total bilirubin (6.20±0.88 mmol/L vs 4.83±0.57 mmol/L, P＜0.05), liver necrotic area (47.50%±4.65% vs 38.80%±5.00%, P=0.043), and protein expression of the marker for hepatocyte apoptosis clea-caspase-3 (26.00±2.11 vs 18.40±1.54, P=0.042). Compared with the control mice, the model mice had significant increases in the expression of p-PERK, XBP1s, P58IPK, and CHOP in the liver (all P＜0.05). Compared with the female model mice, the male model mice had significantly higher expression of XBP1s (25.92±2.11 vs 15.54±1.21, P=0.033), P58IPK (28.60±2.43 vs 13.56±1.13, P=0.026), and CHOP (27.15±2.61 vs 18.18±1.81, P=0.038) and significantly lower expression of p-PERK (16.82±0.11 vs 22.84±0.03, P=0.043) in the liver. Immunohistochemistry also showed that the male mice had significantly higher expression of CHOP than the female mice (1.00±0.11 vs 0.62±0.03, P=0.032). ConclusionThe uncoordinated activation of the endoplasmic reticulum stress signaling pathway may be involved in the formation of sex difference in liver diseases.

BACKGROUND:Icariin,with antiinflammatory,antioxygenatory and immunoregulatory effects,can be a potential drug for preventing and treating acute liver injury. OBJECTIVE:To investigate the protective effect and possible mechanism of icariin in mice with acute liver injury induced by carbon tetrachloride. METHODS:Thirty-two Kunming mice were equally and randomly divided into the following groups:normal,model,low-dose icariin and high-dose icariin groups.The low-and high-dose icariin groups were continuously gavaged with icariin(100 and 200 mg/kg,respectively)once a day for 7 continuous days.The normal group and model group were injected with physiological saline(10 mL/kg)at the same time point.After the last administration,all the groups except for the normal group were injected with carbon tetrachloride to induce acute liver injury.The mice were killed 24 hours later,and the liver index was detected.Serum levels of alanine aminotransferase and aspartate aminotransferase were detected by automated biochemical analysis.Tumor necrosis factor α and interleukin 6 levels in serum were detected using ELISA.The levels of superoxide dismutase,glutathione peroxidase and malondialdehyde in liver tissue were detected through a reagent kit.The histopathology changes of the liver were observed by hematoxylin-eosin staining.TUNEL method was used to detect the apoptosis in hepatocytes.Western blot was performed to detect the expression levels of glucose-regulated protein 78 kDa,endoplasmic reticulum stress-related protein(C/-EBP homologous protein),mixed lineage kinase domain-like protein and Caspase-3 in liver tissue. RESULTS AND CONCLUSION:Compared with the normal group,the liver index and serum levels of alanine aminotransferase,aspartate aminotransferase,tumor necrosis factor α and interleukin 6 were increased in the model group(P＜0.05).Compared with the model group,the above indexes were decreased in the low-dose and high-dose icariin groups(P＜0.05).Compared with the normal group,the activities of superoxide dismutase and glutathione peroxidase in the liver tissue of mice were decreased in the model group(P＜0.05)and the level of malondialdehyde was increased(P＜0.05).Compared with the model group,the activities of superoxide dismutase and glutathione peroxidase were increased in the low-and high-dose icariin groups(P＜0.05)and the level of malondialdehyde was decreased(P＜0.05).Hematoxylin-eosin and TUNEL staining showed that mice in the model group had severe structural destruction of liver tissue,extensive necrosis of hepatocytes and high apoptotic rate of hepatocytes,while the structural destruction of liver tissue and the area of necrosis of hepatocytes in the low-and high-dose icariin groups were significantly milder than those in the model group,and the apoptotic rate of hepatocytes was lower than that in the model group(P＜0.05).Western blot assay showed that the protein expression of glucose-regulated protein 78 kDa,C/-EBP homologous protein,mixed lineage kinase domain-like protein and Caspase-3 in liver tissue of mice in the model group was increased compared with that in the normal group(P＜0.05),while the expression levels of these proteins in liver tissue of mice were significantly reduced after low-and high-dose icariin intervention(P＜0.05).To conclude,icariin can produce a protective effect against carbon tetrachloride-induced acute liver injury,and its mechanism may be related to the regulation of endoplasmic reticulum stress and reduction of programmed necrosis.

Acute liver injury (ALI) is often caused by virus infection, alcohol, drugs, toxin, and metabolic disorder, and oxidative stress is a common pathophysiological mechanism in the development and progression of ALI and other liver diseases. Hepatocyte function is impaired after ALI, which further causes oxidative stress, and persistent or high-intensive oxidative stress may increase the risk of hepatocyte death and thus result in a series of liver diseases. Oxidative stress is mainly associated with the signaling pathways including nuclear factor erythroid 2-related factor 2 and nuclear factor-kappa B. Therefore, it is of great importance to understand the mechanism of oxidative stress in the development and progression of liver injury and related pathways. This article introduces oxidative system and antioxidative system, oxidative stress and damage factors, and oxidative stress and pathways associated with liver injury, so as to provide a reference for the selection of therapeutic targets for ALI and related clinical research.