siRNA targeting fas protects donor liver against cold preservation and ischemic reperfusion injury in rat liver transplantation

AIM:To investigate the silencing effect of fas siRNA to alleviate ischemic-reperfusion (I/R) injury in liver transplantation. METHODS:Three pairs of 21-nt synthesized fas siRNAs were transfected into BRL cells respectively for evaluation of silence efficacy, and the most effective fas siRNA was chosen in vivo for experiment. In cold preservation experiment, siRNA was transfected in vivo by hydrodynamics method. After 48 h, livers of fas siRNA group and control group were harvested and cold preserved, and cell apoptosis and fas expression was evaluated at 2, 4 and 6 h. Orthotopic liver transplantation was performed in fas siRNA group and blank control group. At 1, 3, 6, 12 and 24 h after transplantation, blood and liver samples were collected for evaluation of serum ALT levels, Fas protein and mRNA expression, and apoptosis by TUNEL staining. RESULTS:fas siRNA2, which began at nt 315, inhibited fas gene expression much more than other siRNAs. As to cold preservation, apoptosis index (AI) and fas expression in fas siRNA group was lower than that in control group at each checked point (P<0.01). At 1, 3, 6, 12, and 24 h after blood reperfusion of liver transplantation, the serum ALT level in fas siRNA group was much less than that in control group. The cell apoptosis in fas siRNA group was substantially decreased, and the expressions of fas mRNA and protein were dramatically reduced. CONCLUSION:fas-mediated apoptosis plays an important role in I/R injury of rat liver transplantation. Silencing fas by siRNA holds therapeutic promise to limit I/R injury.     

Protective effects of somatostatin and octreotide on hepatocytes

AIM: To investigate the protective effect of somatostatin (SST) and octreotide (OCT) on rat hepatocytes. METHODS: The primary hepatocytes were pretreated with different concentrations of SST and OCT. The levels of alanine minotransferase (ALT) and aspartate aminotransferase (AST) in culture supernatant were analyzed by the model of ethanol/carbon tetrachloride (CCl4)-induced hepatocyte injury. Additionally, 75 Sprague-Dawley rats were divided into 5 groups at random, including normal control, model control, SST-treated model groups at high, medium and low doses (200 μg·kg-1·d-1, 100 μg·kg-1·d-1 and 50 μg·kg-1·d-1, respectively). Except for the normal controls, all rats were injected with 40% CCl4 subcutaneously for 8 weeks to establish hepatic fibrosis. Meanwhile, rats of SST-treated model groups were given at different doses of SST twice a day in the same way. Thereafter, the liver function and apoptosis index of hepatocytes were detected by standard enzyme method, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), respectively. RESULTS: Compared with those of injury model group, the hepatocytes pretreated with SST (10-8-10-6 mol/L) and OCT (10-7-10-5 mol/L) exhibited significantly decreased levels of ALT and AST in the culture supernatant. Furthermore, most indices of liver function including ALT, AST, alkaline phosphatase (ALP), total bilirubin (TBIL) and albumin (ALB) improved obviously in all SST-treated groups, especially in the group treated with low dose of SST. The apoptosis index of hepatocytes in the fibrotic liver was also reduced greatly by the treatment with low dose of SST. CONCLUSION: SST and OCT may protect hepatocytes against CCl4-induced injury, inhibit hepatocyte apoptosis, and improve the liver function. These findings suggest them a potential efficiency in the prevention of hepatic fibrosis.     

Protective effect of low dose of hydrocortisone on the liver in LPS attack rats

AIM:To study the effect of different dosage of hydrocortisone on the liver in lipopolysaccharides(LPS) attack rats.METHODS:The model of LPS attack rats was established,and different doses of hydrocortisone were given to the rats. ALT and AST levels in rat plasma were tested,and the histology of rat liver was observed by microscope. RESULTS:ALT and AST levels were high in LPS group and had significant difference compared with the normal control group. ALT level in low dose(LD) group had no significant difference compared with the normal control group. The pathological change in the liver was obviously congested in high dose(HD) group and LPS group,many inflammatory cells were infiltrated. The change of liver in LD group was slight. CONCLUSION:Low dose hydrocortisone may have the protectiive effect on liver in LPS attack rats. High dose and middle dose of hydrocortisone have no effects.     

Protective effect of A. auricula-judae extracts on liver function in septic rats

AIM: To explore the effects of Auricularia (A.) auricula-judae extracts on the liver function in septic rats. METHODS: Forty male Wistar rats were randomly divided into control group, model group, A. auricula-judae polysaccharide group and A. auricula-judae crude extract group. Septic model was induced by the procedure of cecal ligation and puncture (CLP). Intragastric administration was performed every 8 h 3 days prior to CLP. The plasma levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), endotoxin(ET), tumor necrosis factor α(TNF-α), interleukin 6(IL-6) and IL-1β were detected 12 h after CLP. The specimens of the liver were collected to observe the pathological changes. The expression of NF-κB in the liver tissues was detected by the method of immunohistochemistry. RESULTS: Compared with the CLP rats, the intervention of A. auricula-judae polysaccharide and A. auricula-judae crude extract to the septic rats significantly decreased the serum levels of ALT, AST, ET, TNF-α, IL-1β and IL-6 (P<005). The pathological changes of the liver tissues in treatment groups were significantly attenuated compared with CLP group. CONCLUSION: A. auricula-judae polysaccharide and A. auricula-judae crude extract protect liver against sepsis-induced injury by inhibiting the systemic inflammatory response.     

Expression of undulin in experimental rat liver fibrosis

AIM: To observe the expression of undulin (Un) in liver tissue and to clarify the diagnostic significance of serum Un in experimental rat liver fibrosis. METHODS: Rat liver fibrosis was induced by carbon tetrachloride. The expression of Un in liver tissue was detected by immunohistochemical method. Serum Un levels was measured by enzyme immunoassay. RESULTS: Expression of Un increased in fibrotic liver than normal liver, and it was mainly distributed in portal tract stroma, central veins and fibrotic septa in fibrotic liver. Also, the level of serum Un was significantly higher in fibrotic liver than normal liver. CONCLUSION: These data suggest that Un should be a component of the hepatic extracellar matrix, and its expression could be increased greatly in fibrotic rat liver. Serum Un levels may be used as an indicator in liver fibrosis diagnosis.     

Protective effect of aFGF delivery by ultrasound-targeted microbubble destruction on left ventricular function in diabetic cardiomyopathy rats

AIM：To observe the protective effect of delivery of acidic fibroblast growth factor (aFGF) to myocardium by ultrasound-targeted microbubble destruction (UTMD) on left ventricular function in diabetic cardiomyopathy (DCM) rats and to investigate the possible mechanisms. METHODS：Twenty-four rats were intraperitoneally injected with streptozocin to induce DCM and were randomly divided into DCM group and aFGF treatment group. Twelve healthy rats served as normal controls. The rats in aFGF treatment group were infused with SonoVue-aFGF mixed fluid through tail vein and UTMD was simultaneously performed. Four weeks after intervention, all rats underwent cardiac catheterization to mea-sure left ventricular end-systolic pressure (LVESP), left ventricular end-diastolic pressure (LVEDP) and the maximal increase/decrease rate of left ventricular pressure (LV±dp/dtmax). The microvessel density (MVD) of rat myocardial tissues was measured by immunohistochemical staining for CD31. The myocardial collagen volume fraction (CVF) was determined by improved Masson staining. The apoptotic index (AI) was detected by TUNEL method. RESULTS：Four weeks after intervention, the LVESP and LV±dp/dtmax in aFGF treatment group were significantly increased compared with DCM group (P<0.01), while the LVEDP in aFGF treatment group was significantly lower than that in DCM group (P<0.01). The MVD in aFGF treatment group was significantly increased compared with DCM group (P<0.01), but the CVF and AI in aFGF treatment group were significantly lower than those in DCM group (P<0.01). CONCLUSION: Delivery of aFGF to diabetic myocardium by UTMD could improve the left ventricular function of DCM rats and may be a new feasible therapeutic method for DCM.     

The reversal effects of recombinant human augmenter of liver regeneration in immunocomplex induced liver fibrosis

AIM: To observe the anti-fibrosis activity of recombinant human augmenter of liver regeneration (hALR). METHODS: Albumin induced rat model of liver fibrosis was established and hALR was given peritoneally after the model production. Serum concentration of alanine aminotransferase(ALT),aspartic aminotransferase(AST),lactate dehydrogenase(LDH), hepatic collagen contents and pathological examination were selected as observing parameter. RESULTS: Recombinant human augmenter of liver regeneration (hALR) could decrease ALT, AST, LDH concentration of fibrotic rats. The measurements of hepatic collagen contents showed that hepatic collagen contents in hALR treatment group was much lower than those of model group and negative control group. Pathological examination also indicated that the degree of liver fibrosis in hALR treatment group was attenuated in comparison with those of model group and negative control group. CONCLUSION: Recombinant human augmenter of liver regeneration (hALR) had reversal effects on immunocomplex induced rat liver fibrosis.control group. CONCLUSION: Recombinant human augmenter of liver regeneration (hALR) had reversal effects on immunocomplex induced rat liver fibrosis.     

Protective effect of compound Danshen dripping pills on isolated rat myocardium with anoxin/reoxygenation

AIM: The experiment was designed to study the effect of compound Danshen dripping pills (DSDP) on myocardium with anoxin/reoxygenation. METHODS: The myocardial anoxin/reoxygenation model was made in perfused isolated rat heart. DSDP and isosorbide dinitrate (ID) were given at the time of pre-perfusion and reperfusion, then HPLC and H-600 electron microscope were used to detect the change of high energy phosphate and the ultrastructure of myocardial cell. RESULTS: ① The contents of AMP, ADP, ATP and AN in myocardium in only anoxin/reoxygenation group were obviously lower than those in the control group (P<0.01).② The contents of AMP, ADP, ATP and AN in myocardium in the groups with DSDP were higher than those in only anoxin/reoxygenation group (P<0.01), also higher than those in the groups with ID (P<0.01). In the two groups with DSDP, the contents of ATP and AN were close to normal (P>0.05). ③ In the groups with ID, the contents of AMP, ADP, ATP and AN were distinctively lower than those in the control group (P<0.01). CONCLUSION: These results indicated that DSDP administration could significantly increase the content of high energy phosphate in myocardium with anoxin/reoxygenation and decrease the ultrastructure injury of myocardial cells, and its protective effect was better than ID.     

Effect of sorafenib on liver regeneration after partial hepatoectomy in liver cirrhotic rats

AIM: To study the effect of sorafenib on the liver regeneration after partial hepatectomy (PH) in cirrhotic rats. METHODS: Thirty Wistar rats with liver cirrhosis induced successfully with diethylnitrosamine (DEN) underwent 30% PH and then were randomly divided into 2 groups (n=15). The rats in experimental group were fed with sorafenib at dose of 30 mg·kg^-1·d^-1 from the 1st day to the 10th day after PH, while those in control group were fed with vehicle by gavage. The blood and liver tissues of the rats were collected after PH and at the end of the experiment. Liver regeneration rate (LRR) and proliferating cell nuclear antigen (PCNA) expression were assessed for determining the hepatocyte proliferation. The content of alanine transaminase (ALT), albumin (ALB), total bilirubin (TBIL), direct bilirubin (DBIL), angiogenesis related factors including vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR-2), platelet-derived growth factor receptor β (PDGFR-β) and micro-vessel density (MVD) were measured in both groups. RESULTS: LRRs on day 10 after PH were 45.43%±3.36% and 44.21%±2.77% in experimental group and control group, respectively (P>0.05), and the expression of PCNA in hepatic tissues of the rats was not found by the method of immunohistochemistry in both groups. Liver function index had no significant difference between the 2 groups (P>0.05). However, other than VEGF, sorafenib resulted in inhibition of VEGFR-2 and PDGFR-β expression and reduction of MVD in experiment group, and significant difference between the 2 groups was observed (P<0.01). CONCLUSION: Sorafenib does not influence live regeneration after PH in liver cirrhotic rats.     

Protective effects of diltiazem on liver,pancreas and small intestine in hemorrhagic-shock canine

AIM: To investigate the protective effects of diltiazem (Dil) on liver, pancreas and small intestines in hemorrhagic-shock canines and its mechanism. METHODS: The canines were bled to a mean arterial pressure (MAP) of 5.33-6.67 kPa for 30 min to produce the model of shock. During the shock, the dogs received water-soluble calcium channel blocker Dil or normal saline. The MAP was kept at the level for 90 min, then the total blood which was bled previously was reperfused. They were observed for 240 min. RESULTS: Dil could significantly elevated MAP of the hemorrhagic-shock canines (P<0.01) and the activity of superoxide dismmutase (SOD) of pancreas tissue (P<0.01), also it could decrease content of malondialdehyde (MDA) of the liver, pancreas and small intestine tissues (P<0.01). Electron microscope data indicated that Dil-treated dogs have a normal ultrastructure in the liver, pancreas and small intestine tissues. CONCLUSION: Dil can protect the structure and function of the liver, pancreas and small intestine in hemorrhagic-shock canines.     

Protective effects of adenosine on cultured rat hippocampal neurons after oxygen-glucose deprivation

AIM:To investigate the protective effects of adenosine on cultured rat hippocampal neurons after oxygen-glucose deprivation.METHODS:The control and adenosine-treated hippocampal neurons cultured for 12 d were exposed to oxygen-glucose deprivation environment for 0.5-4 h and then cultured with original medium in normoxia for 24 h. The soma area, survival rate, effluxes of lactate dehydrogenase (LDH)and apoptosis of neurons were observed.RESULTS:The soma area, effluxes of lactate dehydrogenase from neurons and apoptosis were increased while survival rate of neurons was decreased after oxygen-glucose deprivation compared with those pre-oxygen-glucose deprivation. Compared with the control, after oxygen-glucose deprivation the soma area, effluxes of lactate dehydrogenase from neurons and apoptosis were decreased, however, the survival rate of neurons was increased in the adenosine group.CONCLUSION:Oxygen-glucose deprivation can lead to the severe damage of cultured hippocampal neurons, and adenosine can reduce neuronal injury induced by oxygen-glucose deprivation.     

Expression of calpain 2 and Bax in rat fibrotic liver tissues

AIM：To observe the expression of calpain 2 and Bcl-2-associated X protein (Bax) in rat fibrotic liver tissues and to explore their effects on hepatic fibrosis.
METHODS：Forty male Wistar rats were randomly divided into four groups (each n=10): 4-week control group, 8-week control group, 4-week liver fibrosis group and 8-week liver fibrosis group. Liver fibrosis model was induced by subcutaneous injection of 40% CCl4 (3 mL/kg) every 3 days for 4 or 8 weeks. The apoptosis of hepatocytes was detected by TUNEL. Additionally, the mRNA expression of calpain 2 and bax was determined by real-time PCR, and the protein expression of calpain 2 and Bax was determined by immunohistochemistry and Western blotting. RESULTS：Real-time PCR showed that the mRNA expression of calpain 2 and bax in liver tissues was elevated in 4-week and 8-week liver fibrosis groups. The results of immunohistochemistry and Western blotting revealed that there was no difference of calpain 2 protein expression in liver tissues between 4-week liver fibrosis group and control group, but that in 8-week liver fibrosis group was obviously increased. The protein expression of Bax in 4-week and 8-week liver fibrosis groups was higher than that in control groups. Additionally, the numbers of apoptotic hepatocytes in 4-week and 8-week liver fibrosis groups were obviously increased compared with control groups.CONCLUSION：Calpain 2 and Bax may play important roles in the process of liver fibrosis.     

Protective effects of sequoyitol on type 2 diabetic rats with liver inflammatory lesions

AIM：To investigate the possible protective effect of sequoyitol on type 2 diabetic rats with liver inflammatory lesions. METHODS：Type 2 diabetic rats were induced by feeding high-fat/high-sugar diet and injecting with a low dose of streptozotocin. Sequoyitol at doses of 12.5, 25 and 50 mg·kg-1·d-1 was orally administered in the model rats. At the end of the experiment, the rats were sacrificed. Serum levels of fasting blood glucose, alanine aminotransferase(ALT), aspartate aminotransferase(AST) and albumin(ALB) were determined. Liver wet was recorded and liver index was calculated. The levels of C-reactive protein(CRP),tumor necrosis factor α(TNF-α) and interleukin 6(IL-6) in the liver tissues were also measured. Real-time PCR was used to determine the mRNA expression of TNF-α. In addition, the pathological changes of the liver were observed with HE staining. RESULTS：Compared with the model rats, treatment with sequoyitol obviously decreased the levels of fasting blood glucose, ALT, AST, ALB, CRP, TNF-α and IL-6, reduced the liver index, down-regulated the mRNA expression of TNF-α in the liver, and ameliorated the pathologic changes of the liver. CONCLUSION：Sequoyitol attenuates liver lesions in type 2 diabetic rats through down-regulation of TNF-α and IL-6 expression.     

Effects of liver regeneration on the proliferation of rat fetal hepatocytes after intrasplenical transplantation

AIM:To study the effect of environment of liver regeneration on the proliferation of rat fetal hepatocytes after intrasplenical transplantation. METHODS:Fetal hepatocytes isolated from 3-week SD rat fetuses bred were transplanted into the spleens of liver regeneration model rats with 70% partial hepatectomy. The cell cycle of the hepatocytes in the remnants liver was analyzed by flow cytometer and the density dimensions of the donor fetal hepatocytes in spleen were measured by image analysis system 7 and 30 days post-transplantation, respectively. RESULTS:Compared with the control group, the proportions of S and G₂ /M cells in the remnants liver were obviously decreased (P＜0.05), but the density dimensions of the donor fetal hepatocytes in spleen increased significantly (P＜0.05) in rats with hepatectomy 7 days post-transplantation. CONCLUSION:The environment of liver regeneration is propitious to the proliferation of fetal hepatocytes after transplantation into spleen.     

Effect of 4.25% peritoneal dialysis solution on CD40 expression in rat peritoneal mesothelial cells

AIM:To investigate the effect of 4.25%peritoneal dialysis solution (PDS) on CD40 expression in rat peritoneal mesothelial cells so as to reveal the potential mechanisms by which CD40-CD40 ligand (CD40L) interaction may be involved in the inflammation of peritoneal membrane. METHODS:Rat peritoneal mesothelial cells (MC) were harvested from the peritoneal cavity and maintained under defined in vitro conditions. Expression of CD40 on MC under normal culture or stimulation with 4.25%PDS or 4.25%PDS+IFN-γ was detected by RT-PCR and FACS analyses. After activation of CD40 on MC with CD40 mAb, the expression of intercellular adhesion molecule-1 (ICAM-1) on MC was analyzed by FCAS. RESULTS:MC cultured in vitro expressed CD40 constitutively. 4.25%PDS markedly up-regulated the expression of CD40 mRNA and its protein. The expression of CD40 mRNA and its protein following stimulation with 4.25%PDS+IFN-γ was significantly higher than 4.25%PDS alone. The expression of ICAM-1 on MC was significantly increased after activation of CD40 with CD40mAb.CONCLUSIONS: MC functionally express CD40.The up-regulated CD40 expression on MC fol owing stimulation with 4.25%PDS may play an important role in local peritoneal defense mechanisms and may be involved in the chronic inflammatory process of the peritoneum.     

Morphology of endoplasmic reticulum and expression of GRP78 in rat fibrotic liver

AIM: To observe the changes of endoplasmic reticulum and the biomarker of endoplasmic retidum stress (ERS), glucose-regulated protein 78(GRP78),in the process of liver fibrosis induced by carbon tetrachloride (CCl₄). METHODS: Male Wistar rats weighing 180 g to 220 g were divided into control group and liver fibrosis group. The rats in liver fibrosis group were induced by hypodermic injection of CCl₄ for 4 weeks or 8 weeks. The liver index and the serumactivity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were analyzed. The liver fibrosis and the morphological changes of endoplasmic reticulum were observed under light and electronic microscopes, respectively. Additionally, the expression of GRP78 at mRNA and protein levels was determined by real-time PCR and the method of immunohistochemistry, respectively. RESULTS: The liver index, serum ALT and AST activity in liver fibrosis group were obviously higher than those in control group. Swelling and reduced number of endoplasmic reticulum were observed in the hepatocytes of fibrotic rats compare to the controls. The levels of GRP78 protein and GRP78 mRNA in the liver of hepatic fibrotic rats were obviously higher than those in the control rats. CONCLUSION: In the process of liver fibrosis induced by CCl₄, the obvious morphological changes of endoplasmic reticulum and increased expression of ERS protein indicate that ERS plays an important role in the liver fibrosis.     

Effect of capsaicin on liver fibrogenesis in rats

AIM：To investigate the effects of capsaicin on rat hepatic stellate cells (HSCs) in vitro and on the liver fibrogenesis in vivo. METHODS：HSCs were cultured with different concentrations of capsaicin. The levels of reactive oxygen species (ROS) were tested with a DCFH-DA kit. The proliferation of HSCs was detected by CCK-8 assay. The expression of α-smooth muscle actin in HSCs was evaluated by Western blotting. The expression of fibrosis-related genes was detected by RT-PCR. The apoptosis of HSCs was measured by flow cytometry. The rat model of liver fibrosis was established by intraperitoneal injection of carbon tetrachloride. Capsaicin at different concentrations was given by gavage. The pathologic changes of the liver sections were observed under microscope with HE staining. Hydroxyproline content in the liver tissues and the levels of collagen Ⅲ and hyaluronic acid in the serum were also measured. RESULTS：Capsaicin inhibited the generation of ROS in a concentration-dependent manner. Compared with control, the proliferation and activation of HSCs were inhibited (P<0.05) and the apoptosis of HSCs was promoted by capsaicin (P<0.05). Capsaicin down-regulated the expression of tissue inhibitor of metalloproteinase 1 and transforming growth factor β 1 in activated HSCs (P<0.05). Capsaicin decreased the levels of hydroxyproline, collagen III and hyaluronic acid in the rats (P<0.05). CONCLUSION：Capsaicin inhibits the proliferation and activation, and promotes the apoptosis of hepatic stellate cells, thus down-regulating the fibrogenesis level of the liver in rats．     

Effects of acetal hairy holly extractive compound R4 on rat cardiomyocyte injury induced by hypoxia/reoxygenation

AIM: To observe the effects of acetal hairy holly extractive compound R4(AHHECR4) on myocardial cell injury induced by hypoxia/reoxygenation. METHODS: The model of rat myocardial cell injury was induced by hypoxia/reoxygenation. The activity of superoxide dismutase (SOD) in the myocardial cells was measured by the method of xanthine oxidase. The content of malondialdehyde (MDA) was determined by the method of thiobarbituric acid. The activity of dehydrogenase (A) in mitochondria was detected by MTT assay. The activity of lactate dehydrogenase(LDH) and the content of NO in the culture medium were also evaluated. RESULTS: AHHECR4 at concentrations of 5, 10 and 20 μmol/L remarkably increased SOD activity and the value of A, and significantly inhibited MDA production and LDH leakage. Greatly increased content of NO in the culture medium was also observed. CONCLUSION: The results indicate that AHHECR4 has a protective effect on myocardial cells under the condition of hypoxia/reoxygenation injury.