Therapeutic mechanisms of tumor necrosis factor-α monoclonal antibody on hepatopulmonary syndrome in rats

AIM: To investigate the expression of iNOS in the lung of HPS rats treated with tumor necrosis factor-α monoclonal antibody (TNF-α-McAb) and to investigate the therapeutic mechanism of TNF-α-McAb on hepatopulmonary syndrome. METHODS: Male Sprague-Dawley rats, weighing （250±25）g, were randomized to sham operation group, common bile duct ligation (CBDL) group and CBDL+TNF-α McAb treatment group. Histopathological changes of the lung tissue were evaluated by hematoxylin and eosin staining. The mRNA expression of iNOS in the lungs of hepatopulmonary rats was examined by RT-PCR, while the changes of iNOS in the protein level were evaluated by immunohistochemistry and Western blotting. RESULTS: The inflammatory responses in the CBDL rats treated with TNF-α-McAb decreased than that in CBDL group. Compared to CBDL group, the distribution of iNOS protein and the mRNA expressions in the lung tissue in TNF-α-McAb group were inhibited. CONCLUSION: TNF-α-McAb inhibits the expression of iNOS and plays a role in the treatment of HPS.     

Effect of glutamine on heat shock protein-70 and tumor necrosis factor-α expession in endotoxemic rats

AIM: To study the protective effect of glutamine (Gln) against endotoxemia by observing the effect of glutamine on heat shock proteins (HSPs) and tumor necrosis factor-α (TNF-α) in endotoxemic rats. METHODS: The rats were randomly divided into 3 groups, lipopolysaccharide group (LPS), glutamine-treated group (Gln) and control group (C). The blood was drawn from lateral tail vein for analysis of cytokine levels at 0, 2, 4 and 6 h post-lipopolysaccharide (LPS) challenge. TNF-α was measured by radioimmunity assay. Multiple tissues were harvested from the rats, and HSP70 was detected by immunohistochemistry. At the same time, lung, liver, and ileum tissue section were stained with hematoxylin and eosin. RESULTS: Gln treatment resulted in marked attenuation of TNF-α expression at 2 h post-LPS injection (P＜0.01). Gray gradients of HSP70 in lungs, liver and ileum tissue in group Gln were much lower than those of group LPS (P＜0.05), This suggested that HSP70 content in these tissues of group Gln was higher than that of group LPS. Tissue sample from lung, liver and ileum revealed significantly less evidence of endotoxin-induced tissue damage in Gln-treated animals. CONCLUSION: Gln can significantly enhance HSP70 expression in multiple tissues of endotoxin-treated rats. A single dose of intravenous Gln given concomitantly with an endotoxin injury can markedly reduce organ histological damage, and attenuate pro-inflammatory cytokine release.     

Level of intestinal endotoxemia in Alzheimer disease rats

AIM: The objective of the study was to explore whether intestinal endotoxemia participate in the development of Alzheimer disease. METHODS: Adult Wistar rats were subjected to 90 days intraperitoneal injection with D-galactose and aluminum trichloride (AlCl3) to establish the model of Alzheimer disease. After the administration, the study and memory ability in the rats were observed by Morris water maze. The level of lipopolysaccharide (LPS) in the sera of Alzheimer diseases rats was determined by tachypleus amebocyte lysate method. The level of tumor necrosis factor-α (TNF-α) and interleukin-1 (IL-1) in the sera were determined by radioimmunoassay. The expressions of amyloid β-protein precursor (APP), presenilin 1 (PS1) and β-site APP-cleaving enzyme (BACE) in hippocampus were detected by RT-PCR. RESULTS: Compared with the normal control, the level of LPS in the sera and the expressions of APP, PSI, BACE mRNA in the hippocampus were markedly increased (P<0.01). CONCLUSION: The rat model of Alzheimer disease established by D-galactose and AlCl3 exposure is accompanied intestinal endotoxemia. This result suggests that intestinal endotoxemia plays an important role in the development of Alzheimer disease.     

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.     

CO2 与养分交互作用对番茄幼苗养分利用的影响

以番茄(Lycopersicon esculentumMill.)‘合作906’为材料进行溶液培养试验,设2个因子:CO2和营养液浓度;CO2浓度设正常(360μL/L)和倍增(720μL/L)2个水平;营养液浓度设基本营养液(日本山崎番茄营养液),微量元素采用阿农营养液配方的1/2、1/4、1/8、1/164个水平,完全试验方案8个处理,3次重复。pH为6·0±0·2,3d更换1次营养液。移植到1·2L盆(2株/盒)中,植株在CO2生长箱(VS-3DMC)中培养,全天施放CO2,白天25℃,晚上15℃,光照为14h/d,光照强度11000lx,相对湿度60%。46d时收获,根、茎、叶经蒸馏水冲洗吸干水分后,放入纸袋105℃杀青,75…     

Mechanisms underlying the protection of berberine against liver injury induced by lipopolysaccharide in mice

AIM: To investigate the protective effects of berberine against liver injury induced by lipopolysaccharide in mice and the mechanisms underlying its protective effect. METHODS: The male mice were divided randomly into control, berberine group, LPS group and berberine treatment group. Mice were administered intragastrically with distilled water (0.01 mL/g) or 5 g/L neutral sulfate berberine (0.01 mL/g) once a day for 5 days and injected intraperitoneally with normal saline or LPS （0.02 mL/g，28 mg/kg）at 1 h after gavage on day 5. Blood was collected for determining alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, the content of tumor necrosis factors-α (TNF-α) at 10 h and 2 h after LPS or normal saline injection, respectively. Furthermore, the liver tissue was processed, and histological changes and ultrastructure in liver were observed with light and electron microscopy, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in liver were also detected. RESULTS: Both ALT and AST activities in serum in LPS group were higher than those in control and berberine treatment group. LPS increased the serum TNF-ɑ content at 2 h after injection, which was reversed by berberine pretreatment. The histological examination showed that LPS caused severe hepatic cell edema, degeneration, apoptosis and even necrosis, and ultrastructure observation demonstrated that LPS induced mitochondrial swelling, condensation and margination of chromatin, irregular nuclear envelope in hepatocytes. The above pathological changes produced by LPS were attenuated by berberine pretreatment. Moreover, MDA contents in liver tissue were higher in LPS group than control and berberine treatment group, but there were no significant difference in SOD activity between berberine treatment and LPS group. CONCLUSION: Berberine has a protective effect on LPS-induced liver injury in mice, the mechanisms may be related to its decreasing the production of TNF-α, inhibiting lipid peroxidation and protecting mitochondria.     

Effect of tetramethylpyrazine on neurocognitive impairment and functional imaging changes induced by lipopolysaccharide

AIM: To investigate the effect of traditional Chinese medicine tetramethylpyrazine on neurocognitive impairment and functional imaging changes induced by lipopolysaccharide (LPS). METHODS: Sprague-Dawley (SD) rats (〖WTBX〗n=36) were randomly divided into 6 treatment groups (n=6 for each group):control group, sham operation group, LPS group, and low dose, medium dose and high dose of tetramethylpyrazine groups. The rats in LPS group and tetramethylpyrazine groups were intracerebroventricularly injected with LPS (150 μg per rat, dissolved in cerebrospinal fluid), whereas the rats in sham operation group were administered the same volume of cerebrospinal fluid in a similar manner. The rats in low dose group, medium dose group and high dose group were intraperitoneally injected with tetra-methylpyrazine at 50 mg/kg, 100 mg/kg and 200 mg/kg, respectively. The neurocognitive impairment was accessed using Morris water maze. The protein levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were measured by ELISA. The functional imaging changes induced by LPS, including the diffusion motion component of the imaging pure water molecule and the blood perfusion-related diffusion movement, were determined using the imaging IVIM D and IVIM D* functional sequence. RESULTS: In Morris water maze, LPS significantly increased the escape latency, and decreased the number of crossing platform and the time in the target quadrant compared with sham operation group (P<0.05). In addition, low dose of tetramethylpyrazine treatment obviously shortened the escape latency, and increased the number of cros-sing platform and the time in the target quadrant compared with LPS group (P<0.05), but no significant difference between LPS group and medium dose or high dose group was observed. LPS exposure significantly increased IL-1β and TNF-α levels in the cortex and hippocampus compared with sham operation group (P<0.05), while low dose of tetrame-thylpyrazine treatment obviously attenuated the elevated IL-1β and TNF-α levels in the cortex and hippocampus induced by LPS (P<0.05). The imaging results showed that LPS exposure significantly decreased the IVIM D, IVIM D*, and f va-lues of the cortex and hippocampus compared with sham operation group (P<0.05), whereas low dose of tetrame-thylpyrazine treatment obviously inhibited the decreases in IVIM D, IVIM D*, and f values induced by LPS (P<0.05). However, no significant difference of the IVIM D, IVIM D*, and f values between LPS group and midium dose or high dose group was found. CONCLUSION: Tetramethylprazine attenuates neurocognitive impairment induced by LPS in the rats. The mechanism may be related to the inhibition of inflammatory response through the increases in the water molecule diffusion and the perfusion of cerebral blood flow in the brain.     

Curcumin attenuates lipopolysaccharide/D-galactosamine-induced acute rat liver injury via activating autophagy of hepatocytes

AIMTo investigate the effect of curcumin (CUR) on autophagy of hepatovyte in rats with lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver injury (AHI). METHODSThe healthy male Sprague-Dawley (SD) rats were randomized into the control group,AHI group,CUR group, 3-methy-ladenine (3-MA) group and 3-MA+CUR group, with 6 rats in each group. AHI was induced with an intraperitoneal injection of LPS and D-GalN. Liver function was tested 12 h after LPS/D-GalN treatment. Pathological changes of liver tissues were analyzed by HE staining.The amount of autophagic bodies were observed by transmission electron microscopy. The protein levels of autophagy related-proteins LC3 and beclin 1 in livers were detected by Western blot. ELISA were used to examine the serum levels of tumor necrosis factor-α (TNF-α). RESULTSCompared with control group, the serum level of alanine aminotransferase (ALT) and asparated aminotransferase (AST) were significantly increased, hepatic pathological damage were aggravated and serum TNF-α level was significantly increased in AHI group, while the autophagic bodies and the protein levels of LC3 and beclin 1 were increased (P<0.01). Compared with AHI group, the serum level of ALT and AST were significantly decreased, hepatic pathological damage were attenuated and serum TNF-α level was significantly reduced (P?<0.05), while the autophagic bodies and the protein levels of LC3 and beclin 1 were significantly increased in CUR group (P<0.01). Compared with CUR group, the serum level of ALT and AST were significantly increased, hepatic pathological damage were aggravated and serum level of TNF-α was significantly increased in 3-MA group and 3-MA+CUR group, while the autophagic bodies and the protein levels of LC3 and beclin 1 were decreased (P<0.01). CONCLUSION Curcumin protects rats against LPS/D-GalN-induced liver injury, partially due to activation of hepatocyte autophagy in livers.     

Effect of TRPV1 activation on lipopolysaccharide-induced lung inflammatory injury in mice

AIM:To investigate the effects of transient receptor potential cation channel subfamily V member 1 (TRPV1) activation by capsaicin on the inflammation and its underlying mechanisms in lipopolysaccharide (LPS)-induced lung injury in mice. METHODS:A total of 108 specific pathogen-free male ICR mice were randomly divided into 6 groups: normal control group, capsaicin (CAP) control group, capsazepine (CAPZ) control group, endotoxemia group, CAP treatment group and CAPZ treatment group. LPS was intraperitoneally injected 30 min after the subcutaneous injection of CAP or CAPZ. After modeling, the levels of tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), IL-10, substance P (SP) and calcitonin gene-related peptide (CGRP) in the lung were measured by ELISA. The expression of Toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) in the lung tissue was assessed by Western blotting. The pathological changes of the lung tissue were observed under light microscope. RESULTS:The expression of TNF-α, IL-6, IL-10 and NF-κB in the lung tissues at 3 h, 8 h and 16 h was dramatically higher in endotoxemia group than that in normal control group. Compared with endotoxemia group, the levels of TNF-α, IL-6 and nuclear NF-κB in CAP treatment group at 3 h, 8 h and 16 h were obviously decreased, but the level of IL-10 was increased. The changes of the factors mentioned above in CAPZ treatment group were absolutely adverse to those in CAP treatment group. The levels of SP and CGRP were significantly higher in endotoxemia group and CAP control group than those in normal control group, but those in CAPZ control group were lower. Compared with endotoxemia group, SP and CGRP were markedly increased in CAP treatment group and were obviously decreased in CAPZ treatment group. The level of TLR4 in endotoxemia group was distinctly higher than that in normal control group at 3 h, 8 h and 16 h. However, as compared with endotoxemia group, the expression of TLR4 in CAP treatment group and CAPZ treatment group didn’t change much. At 8 h and 16 h after modeling, the degree of lung damage was also decreased in CAP treatment group as compared with endotoxemia group, while that in CAPZ treatment group was aggravated. CONCLUSION: TRPV1 activation obviously inhibits the increase in TNF-α, IL-6 and NF-κB in the lung tissue of endotoxemia mice, and promotes the increase in the anti-inflammatory factor IL-10, as well as the levels of SP and CGRP, but has no effect on the expression of TLR4.     

Perfluorocarbon in combination with ligustrazine protects against lung injury during liver transplantation in pigs with hepatopulmonary syndrome

AIM: To investigate the effects of perfluorocarbon and ligustrazine on lung injury during liver transplantation in pigs with hepatopulmonary syndrome. METHODS: A hepatopulmonary syndrome (HPS) model of pig was established by chronic bile duct ligation. The animals were assigned randomly to 2 groups: (1) Perfluorocarbon in combination with ligustrazine treatment groups (PFCL group): the pigs were treated with intratracheal instillation of perfluorocarbon and ligustrazine; (2) The conventional mechanical ventilation group (MV group): all animals were subjected to mechanical ventilation and orthotopic liver transplantation. After 5 h the lungs were harvested for further analysis. RESULTS: The lung wet to dry weight radio, pulmonary permeation index and leukocyte count in bronchoalveolar lavage fluids (BALF) in PFCL group significantly decreased compared to MV group (P<0.05). Contents of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) in the lung tissue, plasma and BALF of pigs in PFCL group were significantly lower than those in MV group (P<0.05). Moreover, the activation of NF-κB was inhibited markedly by PFCL. CONCLUSION: Perfluorocarbon in combination with ligustrazine effectively reduces the PMN accumulation in the lungs, inhibits TNF-α and IFN-γ production and protects against lung injury during liver transplantation in pigs with hepatopulmonary syndrome.     

Fibronectin supports endotoxemia mice survival

AIM:To study the preventive effect of fibronectin on hepatic failure induced by endotoxin in mice.METHODS:The survival rate was observed in endotoxemia mice injected with fibronectin from human plasma. The tissue damage and expression of TNFα, IL-1β, IL-6 mRNA in hepatocyte were detected by the methods of histology, ultrastructure, DNA fragementation and RT-PCR.RESULTS:①Fibronectin obviously reduced the mortality of endotoxemia mice sensitized by D-galactosamine(GalN). ②Histopathology showed that less necrosis occurred on the hepatocyte of endotoxemia mice injected with fibronectin, compared with saline control. ③Ultrastructure and DNA fragmentation showed fibronectin suppressed hepatocyte apoptosis induced by LPS. ④Fibronectin down-regulated the overexpression of TNFα, IL-1β, IL-6 mRNA on hepatocyte induced by LPS.CONCLUSION:Fibronectin supports endotoxemia mice surrival by down-regulating the expression of TNFα, IL-β, IL-6, it may be a potent therapy for endotoxemia.     

Protective effect of Auricularia auricular-judae polysaccharide on pulmonary tissues of rats with LPS-induced acute lung injury

AIM: To investigate the effects of Auricularia auricular-judae polysaccharide(AAP) on pulmonary tissues of rats with LPS-induced acute lung injury(ALI) and its mechanisms.METHODS: Adult Sprague-Dawley rats were randomly divided into control group, LPS group,low-dose AAP group, middle-dose AAP group, high-dose APP group, and dexamethasone group. The rats were injected with LPS(8 mg/kg, ip) to induce ALI. The rats in the AAP groups were treated with AAP for 7 d before the induction of ALI. The protein concentration in the bronchoalveolar lavage fluid(BALF) was measured. The lung edema degree was measured by detecting the wet/dry weight ratio. The myeloper-oxidase(MPO), total antioxidant capacity(T-AOC), total superoxide dismutase(T-SOD), nitric oxide synthase(NOS) and malondialdehyde(MDA) levels were determined. The pathological changes of the lung tissues were evaluated by HE staining.RESULTS: Treatment with AAP significantly improved LPS-induced lung pathological changes, attenuated the protein concentration in the BALF and wet/dry weight ratio, inhibited the activities of MPO and NOS, reduced MDA level and increased the activities of T-AOC and T-SOD.CONCLUSION: AAP protects against LPS-induced acute lung injury in rats.     

Mechanisms for a decrease in mortality of LPS-challenged mice by rhynchophylline

AIM: To observe effect of rhynchophylline （Rhy） on mortality and organ injury in endotoxemic mice and further investigate the mechanisms of its actions. METHODS: Male mice were randomly assigned into control, LPS, Rhy +LPS and Rhy group, and injected subcutaneously with normal saline (0.05 mL/10 g), or rhynchophylline once a day for 3 d, 1 h after subcutaneously treatment on day 3, LPS (20 mg/kg) or normal saline was injected intraperitoneally. Survival rate was recorded every 12 h for 6 d. In another experiment, 12 h after LPS injection, the left lung and intestine tissue sections were prepared for histological analysis and the right lung were used to determine the ratio of wet to dry lung tissue weight (W/D),the serum was collected to detect the concentrations of alanine aminotransferase（ALT）, aspartate aminotransferase (AST ), bloodureanitrogen (BUN) and creatinine (Cr). In addition, the concentrations of tumor necrosis factor-α (TNF-α), interleukin-1β(IL-1β) and interleukin-10 (IL-10) in serum at 2 h after LPS challenge were detected by enzyme-linked immunosorbent assay. The concentration of NO in serum at 8 h was detected by enzymic method. The effect of Rhy on survival rate of mice subjected to cecal ligation and puncture (CLP) was also observed. RESULTS: Mortality of mice challenged with LPS alone was higher significantly than that in control at 24 h after LPS challenge, pretreated with Rhy at a dose of 8 or 16 mg/kg increased markedly the survival rate of LPS-challenged mice. However, Rhy at a dose of 8 mg/kg significantly increased mortality of mice subjected to CLP. In the histological analysis, severe inflammation was observed both in the lung and intestine tissues in the LPS group. LPS elevated lung W/D, the levels of ALT, AST, BUN, Cr, TNF-α, IL-1β, IL-10 and NO in serum. Pretreatment with Rhy had no obvious improvement in the lung and intestine tissue injury, and no significant depression in the lung W/D and the serum levels of ALT, AST, BUN, Cr, IL-1β, IL-10 and NO, but decreased the level of TNF-α in serum significantly in LPS -treated mice. CONCLUSION: Pretreatment with Rhy reduces the mortality in endotoxemic mice, but not decrease the mortality of mice challenged with CLP, at least in part, through inhibiting the synthesis and secretion of TNF-α.     

Effects of ouercetin on lipopolysaccharide induced hepatocyte injury in vitro

AIM: To study the effects of quercetin on lipopolysaccharide (LPS) induced hepatocyte injury and the expression of TNF-α in vitro. METHODS: Hepatocytes were isolated from male Sprague-Dawley rats by collagenase perfusion. LPS at concentration of 40 mg/L was used to induce injury to the cultured cells, and 0.5-10 μmol/L quercetin was added at the same time. After 24 h of incubation, the cell apoptosis rates were detected by MTT and PI-AnnexinV. LDH and TNF-α were measured by kits. RESULTS: 40 mg/L LPS caused a 27% growth inhibition. The apoptosis rate was 30.2%. LDH leakage was 20 folds higher than normal. TNF-α expression significantly increased. Treated with quercetin at doses of 0.5-10 μmol/L, the apoptosis rate, LDH leakage and TNF-α expression in hepatocytes were attenuated in a dose dependent manner. CONCLUSION: 0.5-10 μmol/L of quercetin protects hepatocytes from injury induced by LPS, which is associated with suppression of the inflammatory cytokine TNF-α.     

Effects of silymarin on LPS-induced acute lung injury in rats

AIM:To investigate the effects of silymarin on lipopolysaccharide (LPS)-induced acute lung injury in rats and its possible molecular mechanisms. METHODS:Fifty-eight male SD rats, weighting 230-250 g, were divided into four groups randomly: normal control (n=12); acute lung injury group (n=15), receiving intravenous LPS (O55∶〖KG-*2〗B5, 5 mg/kg); silymarin alone group (50 mg/kg, n=15); intervention group (n=16, receiving silymarin 50 mg/kg and LPS 5 mg/kg). The specimens were collected 6 hours later. The following changes, including blood gas analysis, the lung wet/dry weight ratio, the pulmonary vascular permeability, histological manifestations, lung tissue myeloperoxidase activity, the levels of TNF-α, IL-1β, MCP-1 and SOD, GSH-Px as well as malonaldehyde and conjugated diene in plasma and lung tissue, were observed. RESULTS:Compared with control group, the lungs of the rats in LPS treatment group showed significant hyperemia and spotted hemorrhage. The inflammatory granulocyte infiltrating, diffused alveolar septum thickening and spotted hemorrhage were observed in pathological examinations. The lung wet/dry weight ratio and Evans blue content (per gram) increased significantly after LPS treatment. The myeloperoxidase activity in plasma and lung tissue, the levels of TNF-α, IL-1β, MCP-1 and SOD, GSH-Px as well as malonaldehyde and conjugated diene were increased significantly in LPS treatment group. However, in intervention groups, all the above-mentioned measurements were reversed significantly by silymarin treatment compared with LPS treatment group. CONCLUSION:Silymarin may decrease inflammatory reaction and oxidative stress, and further decrease lung damage induced by LPS in rats, all indicating protection of silymarin against acute lung injury.     

LPS preconditioning relieves chronic liver injury induced by carbon tetrachloride

AIM:To investigate the effect of lipopolysaccharides(LPS)preconditioning on CCl4-induced liver injury and the change of LPS signal transduction.METHODS:The male Wistar rats were divided randomly into liver-injury group, which were injected with CCl4 5 mL/kg first, three days later were injected 0.3 mL 40% CCl4 and 60% olive oil.Animals in LPS preconditioning group were injected with LPS 0.5 mg/kg before the day CCl4 was given.Rats received high fat diet were as liver injury group, and normal control group received normal diet.The lymphocytes infiltrated in the liver tissue were counted.The endotoxin and ALT level in rat plasma, TNF-α content and expressions of TLR4, p38, p-p38, IκΒ, NF-κΒ in the rat livers were also determined.RESULTS:The lymphocytes in liver slice and ALT level of the plasma in LPS preconditioning group were lower significantly than those in the liver injury group, and the expressions of TLR4, p-p38, NF-κΒ in the liver were the same.In contrast, the expression of IκΒ was higher.CONCLUSION:LPS preconditioning relieves obviously CCl4-induced chronic liver injury.The mechanism may be associated with change of signal transduction of LPS, which results in decrease of pre-inflammatory cytokines.     

Role of 78 kD glucose-regulated protein in development of hepatopulmonary syndrome induced by multiple pathogenic factors

AIM: To explore the role of 78 kD glucose-regulated protein (GRP78) in the development of hepatopulmonary syndrome (HPS) in rats and the relation to intestinal endotoxemia (IETM). METHODS: The experimental animals were randomly divided into HPS groups of the 4th week, the 6th week and the 8th week. Normal control groups at the corresponding time points were also set up. The Wistar rat model of HPS produced in the process of liver cirrhosis was induced by employing multiple pathogenic factors to the animals. The rats in normal control group were designed by feeding with standard diet and tap water. Histopathological changes of the lung and liver were observed under microscope with the staining of hematoxylin and eosin (HE). The concentrations of alanine amino transferase (ALT), endotoxin and tumor necrosis factor α (TNF-α) in plasma, the contents of TNF-α and malondialdehyde (MDA) in the lung tissues were detected. The expression of GRP78 at mRNA and protein levels in the lungs was measured by the methods of RT-PCR and Western blotting, respectively. RESULTS: The level of endotoxin in plasma was gradually increased with the HPS development. The expression of GRP78 at mRNA and protein levels was also gradually increased with the HPS development and was significant at every time point. The endotoxin in plasma was positively correlated with the expression of GRP78 protein in the lung tissues of the rats with HPS. With the HPS development, the levels of ALT and TNF-α in plasma and the contents of TNF-α and MDA in the lung tissues were gradually increased. The content of endotoxin in plasma and the protein expression of GRP78 in the lung tissues were positively correlated with the contents of TNF-α in plasma and TNF-α and MDA in the lung tissues. The contents of TNF-α in plasma and GRP78 at mRNA and protein levels and TNF-α in the lung tissues were higher in the rats with HPS at every time point than those in normal control group. At the 6th week and the 8th week, the contents of endotoxin and ALT in plasma and MDA in the lung tissues of the rats with HPS were significantly higher than those in normal control group. CONCLUSION: IETM originated from the liver cirrhosis acts as a critical stressor of endoplasmic reticulum (ER) stress and activates ER stress in the lung by oxidative stress, resulting in increased expression of GRP78. Therefore,the increased expression of GRP78 induced by ER stress may play an important role in the development of HPS in rats.     

Effect of Kupffer cell blockade on activation of mitogen-activated protein kinases in response to lipopolysaccharide

AIM: Using the mouse model of lipopolysaccharide(LPS) attack,we study the effect of Kupffer cell (KC) blockade on the activation of mitogen-activated protein kinases(MAPKs) signal transduction pathway induced by LPS.METHODS: GdCl₃ (10 mg/kg) or the same volume of NS was continually injected intravenously at 48 h and 24 h before LPS (5 mg/kg) was injected into the male mice of Kunming species.The liver was then took out and KCs were isolated 30 minute after LPS was injected.The KCs isolated from the mice were cultured,and pretreated with GdCl₃ (100 μmol/L) for 1 h.The culture medium containing LPS (100 μg/L) was added and continuously incubated for 30 minute.The protein expression and phosphorylation level of ERK1/2 and p38MAPK in liver or KCs were assayed in vivo and in vitro,and effect of GdCl₃ on the phagocytosis function was observed,respectively.RESULTS: LPS induced the protein phosphorylation of ERK1/2 and p38MAPK in KCs or liver,no effect on the protein expression was observed.GdCl₃ treatment inhibited LPS-induced KCs activation and secretion of TNF-α,however,it had no effect on ERK1/2 and p38MAPK in KCs or liver,neither at the protein expression nor the phosphorylation.KCs secreted a few TNF-α with short time treatment with GdCl₃ alone in vitro.CONCLUSION: KC blockade with GdCl₃ alleviates LPS-induced KCs activation and the release of TNF-α not through modulating intracellular ERK1/2 or p38MAPK signal transduction pathways.We presume that GdCl₃ might reduce liver injury through cross talk of other intracellular signal transduction pathways (JNK,NF-кB,GPCR,etc).     

Effect of intestinal endotoxemia on ICAM-1 expression in the liver of rats

AIM: To investigate the effect of intestinal endotoxemia on intercellular adhesion molecule-1(ICAM-1) expression in the hepatic tissue.METHODS:Rat intestinal endotoxemia was induced by thioacetamide(TAA).Changes in ICAM-1 protein in the liver were detected by Western blot. RESULTS: The molecular weight of the ICAM-1 is 95 kD.Western blot analysis of hepatic tissue from control rats and rats injected with TAA within 6 hours revealed low ICMA-1 expression. ICAM-1 expression upregulation occured in rats with intestinal endotoxemia in experimental liver injury induced by TAA 12 h after TAA injection. ICAM-1 expression, plasma endotoxin level and alanine transaminase activity is of equal rank.CONCLUSION: Intestinal endotoxemia can upregulate ICAM-1 expression in the hepatic tissue and the latter is related to liver injury.