ABSTRACT
Objective To establish a human HepG2 cell growth model under the low oxygen environment induced by cobalt chloride in order to observe the impacts of human HepG2 cell proliferation,cellular cycles and apoptosis,namely cellular growth conditions,under the low oxygen environment induced by cobalt chloride with different concentrations and to study the HepG2 cell growth mechanism under the low oxygen environment induced by cobalt chloride.Methods The human HepG2 cells in the logarithmic phase were randomized grouping as control group and CoCl2 experimental group with different concentrations (50 μm/L,100 μm/L,150 μm/L and 200 μm/L).① HepG2 cell proliferation was tested by MTT assay to calculate cell's suppression rate and draw HepG2 cell growth inhibition curves.② The move ability of HepG2 cells was observed by scratch test.③ The cellular apoptosis and periodic changes were detected using the flow cytometer Annexin-V FITC/PI double-staining and PI single staining methods.④HepG2 cell's Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and Bcl-2 protein expression were detected by Western Blot.Results ① The test results obtained via MTT assay showed that CoCl2 suppressed the human HepG2 cell proliferation within a certain amount of time and concentration and presented a time-dose dependent relation.② Scratch damage trial suggested that the cobalt chloride suppressed the HepG2 cell migration and wound repair capacity and presented a concentration dependent relation.③ Flow cytometer' s test results revealed that the apoptosis rates (％) in control group and experimental group with different concentrations (50 μm/L,100 μm/L,150 μm/L and 200 μm/L) were 3.42,7.74,13.07,20.56,28.53 and 44.45 (P ＜0.05),respectively.The apoptosis rate of the experimental group was significantly increased compared with the control group,as well as showing a concentration dependency.The results of cellular cycles revealed that the cobalt chloride significantly suppressed the HepG2 cell's periodic changes along with increases of concentration,as well as blocked the cell cycle staying in phase G1,thereby suppressing cell proliferation.④Western Blot test:Compared with the control group,the Bcl-2 protein expression was significantly decreased in the experimental group after treatment of cobalt chloride with different concentrations.Conclusion Within a certain range,CoC12-indiuced low oxygen environment can suppress the human HepG2 cell proliferation and healing migration capacity,induce apoptosis and present a time-dose dependent relation.The mechanism is likely associated with decreases of Bcl-2 protein expression.
ABSTRACT
Children's portal hypertension is a hemodynamic abnormalities syndrome,it refers to children with portal vein pressure exceeds 5 mmHg,or portal vein,hepatic venous pressure gradient exceeds 10 mmHg.Etiology of portal hypertension of children:portal vein obstruction,congenital hepatic fibrosis,biliary atresia.Current treatment methods are:drug treatment,varicose vein ligation or sclerosis,surgical treatment.Although the incidence of children's portal hypertension is relatively low,it can cause various serious complications,such as ascites,gastric variceal bleeding,hepatic encephalopathy and so on.To increase awareness,improve the cure rate and reduce complications,the artical will review the children's portal hypertension etiology,pathogenesis,diagnosis,and treatment progress.
ABSTRACT
Objective To observe the effects of intermittent hypoxic preconditioning on the expression of apoptosis-related EPO after 70％ hepatectomy combined with ischemia-reperfusion injury.Methods One hundred and twenty healthy SD rats of clean grade,simple random divided into 3 groups:Sham operation group of 40 rats ; Pure major hepatic resection group was 40 (Major hepatectomy,MH),namely in the hepatic portal blocking liver resection of the left and middle lobes,hepatic portal blocking 20 min ; intermittent hypoxia preconditioning group 40 (Intermittent hypoxia preconditioning,IHP group).Results MH group,S group,IHP group,EPO level in three experimental groups in postoperative residual liver tissue in rats with significant difference (P ＜ 0.05),Intermittent hypoxia preconditioning group of residual liver EPO content was significantly higher than that of simple hepatic resection group 40.Conclusion Intermittent hypoxia preconditioning can promote the expression of residual liver after hepatectomy in EPO.
ABSTRACT
Objective To explore the impact and significance of hypoxia preconditioning on the expression of cytochrome C and caspase 3 protein in rats after hepatic resection.Methods A hepatectomy model was used to study the ischemia reperfusion injury in hepatic resection.Sprague-Dawley rats were randomly divided into the following three groups:normal control (NC) group,hepatic resection(HR) group,and hypoxia preconditioning (HP) group,there were twenty four rats in each group.HP Group was given an 10％ oxygen-mixed gas for 90 minutes before the operation.At 1,6,12 and 24 hours after the operation,the rats were killed and the following tests were conducted:(1) Liver tissue was sampled to observe the expression of cytochrome C and caspase 3 protein; (2) blood was drawn to conduct a chemical examination; (3) Liver tissue and morphology was observed by transmission electron microscopy.Results The serum levels of ALT and AST in HP group were significantly lower than that of HR group (P＜0.05) at 1,6,12 and 24 hours after the hepatic resection.In each time,liver function of the HP group was significantly better than the HR group; The expression of cytochrome C and caspase 3 protein was decreased significantly in HP group at each measurement point.Hepatic cells in HR group showed typical apoptosis signs under transmission electron microscopy (TEM),but no apoptosis was found in HP group.Conclusion HP has marked inhibition to apoptosis by down-regulating the expression of Cyt C and Caspase-3protein and protection to chondrosomes after a hepatic resection.
ABSTRACT
Objective To investigate the effects of intermittent hypoxic preconditioning on residual liver regeneration after parital hepatectomy in rats.Methods Fifty-four Sprague-Dawley rats were randomly divided into 3 groups (each group contained eighteen animals):sham operation group (SO group),parital hepatectomy group (PH group)and intermittent hypoxic preconditioning group (IHP group).The rats in PH group underwent the left and middle lobectomy of liver(70％ hepatectomy).The rats in IHP group were exposed to hypoxic environment of 10％ oxygen for 1 h/d.And after a week,the rats underwent parital hepatectomy.Six rats in each group were sacrificed respectively on postoperative day 1,3 and 5 (POD 1,3 and 5).The resected liver and the regenerated liver were weighed to calculate liver regeneration degree and regeneration index.The values of alaninea minotransferase (ALT) and aspartate aminotransferase (AST) in the inferior vena venous blood were examined by automatic biochemical analyzer.The positive ratio of hepatocellular proliferating cell nuclear antigen (PCNA) in the residual liver was investigated immunohistochemically.Results The degree and index of liver regeneration in IHP group were respectively higher than those in PH group on POD 1 and 3(P ＜0.05),but there were no statistical differences between the two groups on POD 5.The levels of ALT and AST in PH and IHP group began to decline after surgery,but they remined higher than those in SO group.Moreover,the ALT and AST levels in IHP group were significantly lower than those in PH group on POD 1 (P ＜0.05).The positive ratios of hepatocellular PCNA were respectively higher than those in SO and PH group on POD 1,3 and 5 (P ＜ 0.05).Conclusions To some extent,preoperative intermittent hypoxic preconditioning could prevent hepatocellular damage after parital hepatectomy,what is more,it also could promote the remnant liver regeneration.But the mechanism still needs to be studied furter.
ABSTRACT
Objective To observe the effects of intermittent hypoxic preconditioning on the expression of apoptosis-related Bcl-2 and Bax protein after 70％ hepatectomy combined with ischemia-reperfusion injury.Methods A total of fifty-four SD rats were randomly divided into three groups (n =18).Partial hepatectomy hroup (PH Group):Rats underwent the left and middle lobectomy of liver(70％ hepatectomy).Ischemia reperfusion group (IR group):The left and middle lobes of liver were resected during the occlusion of the hepatoduodenal ligament for 20 minutes.Residual liver underwent the process of ischemia-reperfusion.Intermittent hypoxia preconditioning group (IHP group):rats were exposed to hypoxic environment of 10％ oxygen for 1 h/d.After 7 consecutive days,the left and middle lobes of liver were resected under the portal triad clamping.At 12,24 and 48 hours after the operation,the rats were killed and detected.The serum levels of ALT and AST were determined by automatic biochemical analyzer.The expression of Bcl-2 and Bax protein in liver tissue were measured by immunohistochemistry.Results At each time point after surgery,the serum levels of ALT and AST in IR group and IHP group were higher than that of PH group,and IHP group were lower than in IR group.Compared with IR group,the expression of Bcl2 protein significantly increased and Bax protein expression significantly decreased in IHP group.All these differences were statistically significant (P ＜ 0.05).Conclusions Intermittent hypoxic preconditioning might protect residual liver against ischemia reperfusion injury,through increasing the expression of Bcl-2 protein and reducing the expression of Bcl-2 protein to decrease liver cell apoptosis.
ABSTRACT
Caspase proteins play a key role in the process of promoting apoptosis,we can often detect caspase proteins in hepatic ischemia-reperfusion injury and in experimental study on apoptosis.Now studies on caspase proteins in hepatic ischemia-reperfusion injury of experimental field are reviewed.