Effects of splenectomy on CD4+ , CD8+ and spleen function in cirrhotic rats with portal hypertension

AIM:To investigate the effect of subtotal splenectomy on the expression of CD4+、CD8+ and tuftsin in cirrhosic rats with portal hypertension (PHT) . METHODS:Rats liver cirrhosis was induced by subcutaneous injection of 40% CCl4. Fifty rats were randomly divided into five groups (n=10). Group A:control rats;group B:PHT rats;group C:normal rats with total splenectomy;group D:PHT with total splenectomy and group E:PHT with subtotal splenectimy. The hepatic function, the expression of CD4+, CD8+, the ratio of CD4+ to CD8+ and tuftsin were analyzed at the fourth week after treatment. RESULTS:The expression of tuftsin ,the ratio of CD4+ to CD8+ was significantly decreased in PHT rats with total splenectomy compared with PHT rats ［（171±21） ng/L vs （433±44）ng/L,P<0.01;(2.01±0.22 vs 1.12±0.12),P<0.01］. In the group of PHT rats with subtotal splenectomy, the expression of tuftsin, the ratio of CD4+ to CD8+ was higher than those in the PHT rats with total splenectomy ［（434±42） ng/L vs （171±21） ng/L,P<0.01;（1.97±0.18 vs 1.12±0.12,P<0.01］, however, the hepatic function was not show difference（P>0.05）. CONCLUSION:Spleen and immune function is significantly improved in PHT rats after subtotal splenectomy, but the hepatic function is not changed significantly.     

Effect of portal vein transplantation with allogeneic adipose tissue-derived mesenchymal stem cells on liver fibrosis in SD rats

AIM: To explore the influence of adipose tissue-derived mesenchymal stem cells (ADMSCs) transplantation on hepatic fibrosis in rats. METHODS: ADMSCs from abdominal lipid tissues were extracted, cultured and passaged. The hepatic fibrosis rat model was built up and randomly divided into 3 groups: hepatic cirrhosis group (n=14); portal vein transplantation group (n=11) and caudal vein transplantation group (n=14). Computer tomography(CT) perfusion index, histological scores and microvessel density were detected and compared after transplantation of ADMSCs among the 3 groups. RESULTS: After transplantation of ADMSCs, the total hepatic blood perfusion, especially portal vein perfusion, significantly increased in portal vein transplantation group determined by CT perfusion scan (P<0.05), but slightly increased in caudal vein transplantation group. The histological scores showed significant alleviation of fibrosis evidence in portal vein transplantation group, and slightly change of adipose degeneration in caudal vein transplantation group. Microvessel density decreased significantly in portal vein transplantation group as compared to the other 2 groups (P<0.05). CONCLUSION: Transplantation of ADMSCs greatly helps the alleviation of hepatic fibrosis. Portal vein transplantation benefits more than caudal vein transplantation.     

Protective role of heat-shock protein 70 in gastric mucosal lesion induced by endotoxin in cirrhotic rats with portal hypertensive gastropathy

AIM: To investigate the protective role of heat-shock protein 70 (HSP70) in the pathogenesis of gastric mucosal damage in cirrhotic rats with portal hypertensive gastropathy (PHG).METHODS: The rat model of liver cirrhosis with PHG was established by injection with tetrachloride.The animals were divided into normal control group, PHG group, PHG+heat treatment group, PHG+BPI21 group and PHG+endotoxin groups.The endotoxin used in the experiment was at the dose of 3 mg/kg and endotoxin antagonist BPI21 was at the dose of 2 mg/kg.HSP70 was induced by pre-treating the animals with mild whole-body heating.The levels of HSP70 and tumor necrosis factor alpha (TNF-α) in the gastric mucosa were measured by ELISA.Furthermore, the pathological changes of the gastric mucosa were observed under microscope with HE staining.RESULTS: Compared with the normal control rats, the rats in PHG group showed obvious gastric pathological lesion, decrease in HSP70 production and increase in TNF-α level in the gastric mucosa, and increased endotoxin concentration in the plasma.Compared with PHG+endotoxin group, the gastric mucosal lesion in PHG+BPI21 group was significantly attenuated, accompanied by the increase in HSP70 production and decrease in TNF-α level in the gastric mucosa.Heat treatment increased HSP70 production and decreased TNF-α concentration in the PHG rats, thus attenuating the gastric mucosal damage.CONCLUSION: HSP70 alleviates the gastric mucosal lesion induced by endotoxin in cirrhotic rats with PHG and decreases the concentration of TNF-α in gastric mucosa, indicating a protective role of HSP70 in the pathogenesis of gastric mucosal damage in PHG.     

Effects of rosiglitazone,a PPARγ ligand,on chemoprevention of MNNG-induced gastric cancer in rats

AIM: To examine the chemo-preventive effects of peroxisome proliferator-activated receptor γ(PPARγ) ligand rosiglitazone (RSG) on a rat model of gastric carcinogenesis induced by chemical carcinogen N-methyl-N’-nitro-N-nitrosoguanidine (MNNG). We also attempted to identify novel anti-cancer mechanisms of rosiglitazone.METHODS: Ninety male Wistar rats were randomly allocated into six groups: group A (control group); group B (MNNG group); group C, D and E (RSG group, given different concentrations of rosiglitazone). The treatment procedures were terminated at 40th week. Stomach was harvested and gastric carcinoma was verified by histology. The gastric cancer incidence in different groups was calculated. To elucidate the mechanisms underlying the chemo-preventive effects of PPARγ ligand, we examine the gene expression profiles of MNNG induced gastric cancer and the rosiglitazone treated gastric cancer with Uniset Rat I Bioarray microarray.RESULTS: Incidence of gastric cancer in group A-E was 0% (0/10), 70% (14/20), 15% (3/20), 30% (6/20) and 30% (6/20), respectively. Gastric cancer incidence in group C, D and E was significantly lower than that in group B (P<0.01). A gene that showed prominent responses in rosiglitazone treated group was identified. The hypertension-related, calcium-regulated gene (HCaRG) was significantly upregulated in rat gastric carcinoma in rosiglitazone treated group when compared to MNNG group. The expression of HCaRG was down-regulated in human gastric cancerous tissue. CONCLUSION: PPARγ ligand rosiglitazone has a potent chemo-preventive effect against gastric cancer development in rats. Upregulation of HCaRG may be one of the mechanisms underlying the chemo-preventive effect of rosiglitazone in gastric cancer.     

Role of injury and phenotype shift of liver sinusoidal endothelial cells in the development of portal hypertension of cirrhosis in rats

AIM: To study the role of injury and phenotype shift of liver sinusoidal endothelial cells in the development of portal hypertension of liver cirrhosis in rats. METHODS: The rat liver cirrhosis model was established by peritoneal injection of dimethylnitrosamine (DMN) (at a dose of 10 mg·kg^-1, 3 times a week, for 4 weeks). The dynamic changes of liver cirrhosis were observed at different time points (1 day, 2 days, 3 days, 1 week, 2 weeks, 4 weeks, 6 weeks and 8 weeks). The pressure of portal vein (Ppv), the expression of CD44, von Willebrand factor (vWF), endothelin-1 (ET-1) mRNA and endothelial nitric oxide synthase (eNOS) mRNA, the serum hyaluronic acid (HA) content and liver ET-1 content were measured. RESULTS: Compared with the normal control rats, CD44 positive staining was weak in the 1 day model rats, and the numbers of fenestrae of sinusoidal endothelial cells (SECs) rapidly decreased, but serum HA content rapidly increased (P<0.05). vWF positive staining in the 2-day model rats was stronger than that in normal control rats (P<0.05). There was a positive correlation between the Ppv and the vWF expression, serum HA content in the DMN-induced liver cirrhosis rats (P<0.05). Compared with the normal control rats, ET-1 mRNA expression increased in the 2-day and 3-day model rats, and ET-1 content lightly increased. eNOS mRNA expression was stronger in the 1-day, 2-day and 3-day model rats than that in normal control rats, meanwhile eNOS always expressed at a low level. CONCLUSION: The injury and phenotype shift of SECs is a pathological basis in the development of portal hypertension of DMN-induced liver cirrhosis in rats. Imbalance of ET-1 and NO production increases intrahepatic resistance, which plays an important role in the development of portal hypertension.     

Role of 78 kD glucose-regulated protein in the development of liver cirrhosis promoted by intestinal endotoxemia in rats

AIM: To explore the role of 78 kD glucose-regulated protein (GRP78) in the development of liver cirrhosis in rats promoted by intestinal endotoxemia (IETM). METHODS: Fifty-one male Wistar rats were randomly divided into liver cirrhosis groups of 4th-week, 6th-week and 8th-week, and normal control group at the corresponding time points. The rat model of hepatic cirrhosis was induced by employing multiple pathogenic factors to the animals. The liver injury and hepatic fibrosis were observed with the staining of HE and VG, respectively. The expression of GRP78 at the mRNA and protein levels was measured by the methods of RT-PCR and immnunohistochemistry, respectively. The concentrations of alanine aminotransferase(ALT), endotoxin, TNF-α and homocystine (HCY) in plasma, and the content of TNF-α, malondialdehyde(MDA) and PⅢP in liver tissues were detected. RESULTS: As liver cirrhosis developed, the levels of ALT, endotoxin, TNF-α and HCY in plasma, the expression of GRP78 at mRNA and protein, the content of TNF-α, MDA and PⅢP in liver tissues, and the index of liver fibrosis were gradually increased and were significantly higher than those in normal control group (P<0.05). Elevated endotoxin in plasma was correlated positively with the protein expression of GRP78, the content of MDA and HCY in plasma and the index of liver fibrosis (P<0.01). Elevated protein expression of GRP78 was correlated positively with the content of MDA and HCY in plasma and the index of liver fibrosis (P<0.01). CONCLUSION: GRP78 plays an important role in the development of liver cirrhosis. Endoplasmic reticulum stress is a possible mechanism in the development of liver cirrhosis promoted by IETM.     

Effects of glutamine and recombinant human growth hormone on intestinal mucosal barrier and proliferating cell nuclear antigen in postoperative portal hypertension patients

AIM:To investigate morphologic and functional changes of small intestinal mucosa and proliferating cell nuclear antigen in postoperative portal hypertension patients with single or combined administration of Gln and rhGH.METHODS:Twenty-nine portal hypertension patients with surgical treatment were prospectively randomized to four groups as follows: ① Gln group (n=6);② rhGH group (n=8);③ Gln+rhGH group (n=7) and ④ control group (n=8).A standard solution for TPN was given three days after operation for a week.The concentration ratio of urinary lactulose and mannitol (L/M),the villus height and crypt depth and PCNA index of small intestinal mucosa were compared.RESULTS:A week after TPN postoperation,the increased ratios of L/M in Gln+rhGH group were less than those in control group (P<0.05).The villus height and crypt depth increased in Gln+rhGH group compared with preoperation (P<0.05) or control group (P<0.05).PCNA index increased in Gln+rhGH group compared with preoperation (P<0.05) or other three groups (P<0.05).The villus height of control group decreased (P<0.05),whereas the crypt depth had no significant difference (P＞0.05).CONCLUSION:This study suggest that Gln together with rhGH reduce the intestinal permeability and protect the mucosa integrality in postoperative portal hypertension patients,but not in single treatment.     

Prevention of isinglass on the chronic atrophic gastritis in rats and its mechanism

AIM: To evaluate the effect of isinglass on chronic atrophic gastritis(CAG) in rats and its mechanism. METHODS: An animal model of CAG in accordance with the previous experience of combined administration of 60% ethanol, 20 mmol/L sodium deoxycholate and 0.1% ammonia water was established in SD rats. Isinglass was used as preventive therapy while we were establishing CAG rat model. Finally all the rats were executed and pathologic changes of the gastric mucosa were studied by gross appearance and microscopy and serum epidermal growth factor (EFG) and growth hormone(GH) contents were tested. RESULTS: In each isinglass prevention group, inflammation grade of gastric antrum was less than that in model group (P<0.01) while the mean ratio of the thickness of gastric mucosal gland and muscularis mucosa (L1/L2), the number of gastric glands in 1 mm lengths of mucosal layer in longitudinal sections were much better than those in model group (P<0.01).They were very close to normal control group (P>0.05). The expression of proliferating cell nuclear antigen (PCNA) in gastric mucosa and serum EFG level were higher than those in model group (P<0.01, P<0.05), but serum GH content showed no different between isinglass prevention group and model group. CONCLUSION: Isinglass preventes the gastric mucosal atrophy in the CAG model. Its mechanism may be related to the effects of decreasing the gastric mucosal damage， promoting the cell proliferation and increasing of internal EFG secretion.     

The relationship between nitric oxide and gastric mucosal injury induced by reserpine in rats

AIM: To study the relationship between nitric oxide (NO) and gastric mucosal injury induced by reserpine in rats. METHODS: Sixteen healthy male Wistar rats were randomly divided into control group and experimental group (n=8). NO contents and malondialdehyde(MDA) contents in plasma, gastric mucosa of the rats were respectively determined with Cadmium-reduct plus Greiss and TBA; nitric oxide synthase in gastric walls of the rats were observed using NADPH-diaphorase histochemistry and quantitatively measured with image analyzer. RESULTS: The NO contents in both plasma and gastric mucosa of experimental group were significantly lower than that in control group (P＜0.01),but their MDA contents were both higher than that in control group(P＜0.05,P＜0.01);the densities and A values of nitric oxide synthase (NOS)-positive nerve-cells and nerve fibers in gastric walls of experimental group were all obviously lower than that in control group (P＜0.05,P＜0.01). CONCLUSION: The mechanism of the reserpine-induced gastric mucosal injury in rats might be related to NO insufficiency arisen from the inhibition of NOS activity in NANC nerves in gastric wall,which might weaken the protection to gastric mucosa.     

Expression of Hedgehog signaling molecules in rat livers after partial hepatectomy

AIM: To detect the expression of Hedgehog signaling molecules in rat livers after partial hepatectomy. METHODS: The model of rat partial hepatectomy was established by resecting the middle and left lobes of the liver. Eighteen male Sprague-Dawley rats were divided into 3 groups: sham operation group (group A), partial hepatectomy group 1 (group B) and partial hepatectomy group 2 (group C). Hepatic tissues were collected 24 h after the operation in group A and group B, and 48 h after the operation in group C. The expression of Ki-67,Sonic Hedgehog(Shh),Indian Hedgehog(Ihh) and Glioblastoma-2(Gli-2) in the hepatic tissues were detected by immunohistochemical staining and Western blotting. RESULTS: The edema and spotty necrosis in the hepatic tissues were observed in group B and group C by HE staining. The cells of different dividing stages were found in the hepatic tissues of group C. Compared with group A, the expression of Ki-67, Shh, Ihh and Gli-2 in group B (P<0.01) and group C (P<0.01) was significantly elevated, and the expression levels in group C were higher than those in group B (P<0.01). CONCLUSION: Hedgehog signaling in rat livers may be activated after partial hepatectomy and stimulate liver regeneration.     

Effect of metabolites of Clostridium butyricum,butyric acid and hydrogen,on acute gastric mucosal lesion

AIM: To observe the antiulcer effect of butyric acid and hydrogen, the main metabolites of Clostridium butyricum (C. butyricum), and to explore the underlying mechanism. METHODS: The mouse model of acute gastric mucosal lesion was prepared by gavage with ethanol. The mice were randomly divided into 4 groups: normal group, model group, butyric acid group and hydrogen group. The mice in butyric acid group and hydrogen group were given butyrate and hydrogen prior to model establishment, respectively. Macroscopic observation of the pathological changes in gastric tissues was performed to evaluate the effect of the 2 metabolites of C. butyricum. Meanwhile, the mRNA expression levels of inflammatory factors, such as IL-12, RAN1 and MCP-1, were determined by RT-qPCR. The expression levels of apoptosis-related proteins Bcl-2 and Bax were detected by immunohistochemical staining. RESULTS: The macroscopic observation found that butyrate, not hydrogen, protected gastric mucosa. HE staining also showed that butyrate significantly attenuated the pathological damage of the gastric mucosa induced by ethanol. Compared with model group, the mRNA levels of inflammatory factors IL-12, RAN1 and MCP-1 in butyrate group significantly decreased (P<0.01). In butyrate group, the protein level of Bax was obviously decreased compared with model group (P<0.01), while the protein level of Bcl-2 was significantly increased (P<0.01). CONCLUSION: The gastric mucosa protective metabolite of C. butyricum may be butyric acid, not hydrogen. Butyric acid protects the gastric mucosa against ethanol-induced lesion by inhibiting the inflammation and reducing the expression ratio of Bax/Bcl-2.     

Effects of macrophage polarization during development of liver cirrhosis in rats

AIM: To explore the state of macrophage polarization and its relation with intestinal endotoxemia-endoplasmic reticulum stress in the development of liver cirrhosis induced by multiple pathogenic factors in rats. METHODS: The male SD rats (n=36) were randomly divided into normal control group and liver cirrhosis model group, and sacrificed at the end of the 4th, 6th and 8th weeks. The rat model of liver cirrhosis was induced by multiple pathogenic factors. The levels of alanine aminotransferase (ALT), endotoxin, homocysteine (Hcy) in the plasma, and inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), arginase-1 (Arg-1) and interleukin-10 (IL-10) in the liver tissues were detected by ELISA. Histopathological change of the liver was observed under microscope with the staining of hematoxylin and eosin (HE) and van Gieson (VG). The expression of glucose-regulated protein 78 (Grp78), nuclear factor-kappa B (NF-κB), interferon-regulatory factor 5 (IRF5), CD86, CD206 and transforming growth factor-β1 (TGF-β1) at mRNA levels in the liver tissues were detected by the method of real-time fluorescence quantitative PCR.RESULTS: Compared with the corresponding normal control group, the levels of ALT, endotoxin, Hcy in the plasma and Grp78 mRNA in the liver tissues in liver cirrhosis model group were significantly and gradually increased (P<0.05). The mRNA expression of NF-κB, IRF5 and CD86, and the protein levels of iNOS, TNF-α and IL-6 in the liver tissues were significantly increased (P<0.05), and they successively increased from the 4th week to the 6th week and decreased reversely at the 8th week. The mRNA expression of CD206, TGF-β1, Arg-1 and IL-10 in the liver tissues were significantly increased from the 6th week to the 8th week (P<0.05), and no significant difference at the 4th week was observed. The level of endotoxin in the plasma was correlated with the mRNA expression of Grp78 in the liver tissues (P<0.01). Both endotoxin in the plasma and Grp78 mRNA in the liver tissues were correlated with the mRNA expression of CD86 and CD206 in the liver tissues (P<0.01).CONCLUSION: The pathway of liver damage-intestinal endotoxemia-endoplasmic reticulum stress-macrophage polarization may be critical in the pathogenesis of liver cirrhosis induced by multiple pathogenic factors.     

Effect of anisodamine on the reserpine-induced gastric mucosal lesion in rats

AIM: To determine the effects of anisodamine (Ani) administered intraperitoneally on the gastric mucosal lesion induced by reserpine.METHODS:In reserpine-treated rats, gastric mucosal lesion, gastric acid secretion, gastric barrier mucus secretion, gastric contraction, gastric mucosal blood flow (GMBF), gastric mucosal nitric oxide synthase (NOS) activity and nitric oxide (NO) content were examined.RESULTS:Ani in doses of 1,5 and 10 mg/kg significantly inhibited the formation of gastric lesions induced by reserpine, with the suppressive rate of 60.0%, 66.7% and 76.6%, respectively. Ani (10 mg/kg) significantly inhibited the secretion of gastric acid, but had no effect on the volume of gastric juice. Ani (10 mg/kg) significantly prompted the secretion of gastric barrier mucus. Our findings also showed that Ani (10 mg/kg) significantly suppressed the frequency and amplitude of gastric contraction. Ani (10 mg/kg) significantly prompted GMBF. In reserpine treated rats, gastric mucosal NOS activity and NO content were decreased and Ani (10 mg/kg) could inhibit the decrease in NOS activity and NO content.CONCLUSIONS:The protective effect of Ani may results in part from inhibiting gastric acid secretion, prompting gastric barrier mucus secretion, suppressing gastric contraction and improving GMBF. NO seems to play an important mediator role in the Ani protective mechanisms.     

Role of Huoxue Jiangzhi Recipe in preventing and treating fatty liver in mice

AIM: To explore the role of Huoxue Jiangzhi Recipe in preventing and treating fatty liver in mice and its underlying mechanisms. METHODS: Healthy Kunming mice were fed with high-fat diet and treated intragastrically with different doses of Huoxue Jiangzhi Recipe (compound of ginseng, panax notoginseng and rhizoma gastrodiae, named as GST) for 2 weeks. The levels of blood lipids and triglyceride (TG) in hepatic tissues were measured. Meanwhile, liver index and hepatic pathology were observed. The optimized dosage of Huoxue Jiangzhi Recipe was determined by the experiments. The mice were divided into normal control group (NC group, fed with normal diet) and model group (fed with high-fat diet). The model mice were subdivided into 3 subgroups 12 weeks later: HF group (fed continuously with high-fat diet), ND group (fed with normal diet), GSL group (fed with normal diet and treated intragastrically with GSL). The mice in NC, HF and ND groups were given distilled water by gastric perfusion. Two weeks later, all mice were killed, and blood was collected for measuring serum total cholesterol (TC),TG,high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C) contents, hepatic TC, TG, malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity were detected. Moreover, liver index and hepatic pathology were also observed. The mRNA expression of peroxisome proliferator-activated receptor alpha (PPARα) and cytochrome-P450 2E1 (CYP2E1) in the liver was examined by RT-PCR. RESULTS: GST significantly decreased serum lipid, hepatic lipid and MDA levels and elevated SOD activity. Furthermore, GST markedly reduced liver index, improved hepatic adipose infiltration, increased PPARα mRNA expression and inhibited CYP2E1 mRNA expression. CONCLUSION: GST is effective in the treatment of fatty liver in mice by up-regulating PPARα, thus reducing serum and hepatic TG levels, down-regulating CYP2E1 and inhibiting lipid peroxidation.     

Effect of ischemic preconditioning on expression of nitric oxide synthase in rat small-for-size liver graft

AIM:To investigate the effect of ischemic preconditioning (IPC) on expression of nitric oxide synthase (NOS) in rat small-for-size liver graft and its significance. METHODS:Sixty SD rats were randomly divided into 3 groups (n=10 pairs/group):nonwarm ischemia group (NWI);warm ischemic group (WI);and ischemic preconditioning group (IPC). The models of rat small-for-size liver transplantation were set up by two-cuff technique. Expression of eNOS mRNA and iNOS mRNA in hepatic tissue were detected by fluorescence-quantitating-PCR. RESULTS:Heptic expression of eNOS mRNA post-IPC was higher than that pre-IPC (P<0.05). Heptic expression of eNOS mRNA in each group at 0.5, 1, 2 and 3 h post-reperfusion was higher than that pre-operation (P<0.05). It was not different significantly between NWI and WI group (P>0.05). It was higher in IPC group than that in NWI and WI group (P<0.05 or P<0.01). Hepatic expression of iNOS mRNA was detected 1 h after reperfusion of liver graft. It was lower in IPC group than that in WI group (P<0.05 or P<0.01) and lower in NWI group than that in IPC group (P<0.05 or P<0.01) 2 h and 3 h post-reperfusion. CONCLUSION:IPC might protect liver graft by increasing the expression of eNOS mRNA at early stage after reperfusion and decreasing the expression of iNOS mRNA at later stage after reperfusion.     

Changes of histone modification levels in rats with liver fibrosis

AIM: To observe the changes of histone modifications in the liver of rats with hepatic fibrosis and its possible role in the development of hepatic fibrosis. METHODS: Male Wistar rats (n=20) were randomly divided into liver fibrosis group and normal control group. The liver fibrosis model was established by hypodermic injection of CCl₄, and the rats in normal control group were injected with vegetable oils. At the end of the 8th week, all rats were killed. Liver function indexes including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and liver fibrosis indexes including haluronic acid (HA), laminin (LN), collagen type IV (Col Ⅳ) and procollagen type Ⅲ (PCⅢ) were determined by biochemical and RIA methods. The liver index was analyzed, and the liver fibrosis degree and the morphological change of the liver were detected by HE and Masson staining. The levels of α-smooth muscle actin (α-SMA), collagen type Ⅰ (ColⅠ), H3K4me2, H3K9me2, acH3K9 and acH4K12 were detected by Western blot. RESULTS: After hypodermic injection of CCl₄ for 8 weeks, the liver index, ALT, AST, HA, LN, Col Ⅳ and PCⅢ of the rats in liver fibrosis group were higher than those in control group (P<0.05). Compared with control group, the level of acH4K12 was decreased (P<0.05), while acH3K9, H3K9me2, α-SMA and ColⅠ were increased (P<0.05), but H3K4me2 had no significant change.CONCLUSION: The levels of acH4K12, acH3K9 and H3K9me2 may play essential roles in the pathogenesis of liver fibrosis, and these histone modifications may regulate gene expression associated with extracellular matrix metabolism.     

Effects of liraglutide on adiponectin and insulin resistance in rats with non-alcoholic fatty liver disease

AIM：To investigate the effects of glucagon-like peptide 1 analog, liraglutide, on adiponectin and insulin resistance in the rats with diet-induced non-alcoholic fatty liver disease (NAFLD). METHODS：Male rats were randomly divided into 3 groups:normal diet (ND) group (n=10), high-fat diet (HFD) group (n=10), and HFD with intraperitoneal injection of liraglutide group (n=10, first 12 weeks with HFD, later 4 weeks with liraglutide). All treatments continued for 16 weeks, and then the rats were killed ethically and the blood samples and liver tissues were collected. The levels of alanine aminotransferase (ALT), fasting blood glucose (FBG), total cholesterol (TC) and triglyceride (TG) were detected by a biochemical automatic analyzer. The levels of free fatty acids (FFAs), fasting insulin (FINS) and adiponectin were measured by RIA and ELISA. RESULTS：Compared with HFD group, the body weight, liver index, homeostasis assessment-insulin resistance (HOMA-IR), the serum levels of TG, TC, ALT and FBG, and the liver levels of TG, TC and FFAs in the rats in liraglutide group were apparently lower, the degree of hepatic steatosis and inflammatory activity significantly decreased (P<0.05), and the level of adiponectin in the serum and liver homogenate increased ob-viously (P<0.05). The level of adiponectin in the liver homogenate was negatively correlated with the levels of FFAs in the liver homogenate. CONCLUSION:Liraglutide is beneficial for NAFLD rats to improve insulin resistance and reduce hepatic steatosis by increasing the level of adiponectin in the serum and liver tissues.     

Effect of ERK1/2 on ischemic preconditioning in diabetic rat hearts

AIM: To test the effect of ERK1/2 on ischemic preconditioning (IPC) in diabetic rat hearts. METHODS: The diabetic rat model was made with alloxan. After eight weeks, 24 rats were divided into 4 groups: non-diabetic IPC rats (group A); non-diabetic non-IPC rats (group B); diabetic IPC rats (group C); diabetic non-IPC rats (group D). ECGⅡ lead, left ventricular development pressure (LVDP), and first derivative of LVDP (±dp/dtmax) were recorded. Myocardial phosphorylation of extracellular signal regulated kinases1/2 (ERK1/2) was detected by Western-blotting. RESULTS: (1) The ventricular arrythmia score was significantly lower in group A than that in group C (P<0.01). (2) LVDP and +dp/dtmax % were significantly higher in group A than those in group B and group C (P<0.01). -dp/dtmax% was significantly higher in group A than that in group B. (3) Phosphorylation of myocardial ERK1/2 was significantly higher in group A than those in group B and group C. CONCLUSIONS: IPC reduced the severity of ischemia/rerperfusion- induced arrhythmias, improved cardiac function in non-diabetic rats. However, such beneficial effects of IPC were not observed in diabetic rats. The attenuation of cardioprotection by IPC in diabetic animals may be due to the decrease in the activation of myocardial ERK1/2.     

EGFR-p38 MAPK signaling pathway is involved in expression of HMGB1 in pulmonary tissues of rats with ventilator-induced lung injury

AIM: To investigate the role of epidermal growth factor receptor (EGFR)-p38 mitogen-activated protein kinase (MAPK) pathway in the expression of high mobility group box 1 protein (HMGB1) in the lung tissues of rats with ventilator-induced lung injury (VILI).METHODS: Thirty-two healthy Sprague-Dawley (SD) rats were randomly divided into 4 groups (n=8 each): group A, spontaneous breathing; group B, small tidal volume ventilation (VT=8 mL/kg); group C, high tidal volume ventilation (VT=40 mL/kg); group D, high tidal volume ventilation plus EGFR antagonist AG-1478. The rats in group B, group C and group D were mechanically ventilated for 4 h and then all animals were sacrificed.Total protein content and white blood cell (WBC) count in bronchoalveolar lavage fluid (BALF), the lung wet/dry weight ratio (W/D) and myeloperoxidase (MPO) activity were determined. The histological changes of lung tissues were observed by HE staining. The EGFR protein and mRNA expression, p38 MAPK activity and HMGB1 protein expression in the lung tissues were also detected.RESULTS: The inflammatory responses as evidenced by lung HE staining, total protein and WBC in BALF, the lung W/D and MPO activity were significantly higher in group C than those in group A (P<0.05). The mRNA expression of EGFR, EGFR activity, p38 activity and HMGB1 protein level also significantly increased in group C (P<0.05) as compared with group A. Significant decreases in the above indexes in group D were observed as compared with group C.CONCLUSION: High tidal volume ventilation induces acute lung injury, which may be related to up-regulation of HMGB1 expression through EGFR-p38 MAPK signal pathway.     

Pretreatment of hypertonic saline attenuates the hepatic ischemia reperfusion injury induced by neutrophils

AIM: To explore the effect of the pretreatment of hypertonic saline (HTS) in hepatic ischemia reperfusion (I/R) injury.METHODS: The rats were divided into sham group (sham group), ischemia reperfusion group (IR group) and pretreatment of hypertonic saline group (HTS group). Partial hepatic ischemia reperfusion model was used. The rats were sacrificed at the time of 1 h, 3 h, 6 h, 12 h and 24 h after reperfusion in each group, respectively. Blood samples were obtained to examine ALT. The expression of the CD11b/CD18 (Mac-1) on the neutrophils was analyzed by flow cytometry. RT-PCR and Western blotting were used to examine the expression of intercellular adhesion molecule-1 (ICAM-1) in livers and chromatometry was performed to detect the activity of myeloperoxidase (MPO) in livers. The morphology of hepatocytes and the structure of sinusoid were observed by histological examinations. RESULTS: ① HTS pretreatment decreased the level of ALT at the time points of 3 h, 6 h and 12 h after reperfusion (P<0.05). ② Mac-1 expression in HTS group was lower at 6 h and 12 h after reperfusion compared with IR group (P<0.05). ③ MPO activity in HTS group was lower at 6 h, 12 h and 24 h compared with IR group (P<0.05). ④ RT-PCR and Western blotting analysis indicated that the pretreatment of HTS inhibited the expression of ICAM-1 in livers after reperfusion. ⑤ Moderate hepatocyte swelling and few neutrophil infiltration were observed in HTS group.CONCLUSION: Pretreatment with HTS has the effect on hepatic ischemia reperfusion injury by inhibiting the expression of Mac-1 on circulating neutrophils and the expression of ICAM-1 in the liver.