Role of p38MAPK in production of pro-inflammatory cytokines in Kupffer cells from severe acute pancreatitis rats

AIM:To investigate the role of p38 mitogen-activated protein kinase (p38MAPK) signaling pathway in the Kupffer cells (KCs) production of pro-inflammatory cytokines, tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β), in severe acute pancreatitis (SAP) rats.METHODS:Sprague-Dwaley rats were randomized into three groups:①sham operation rats, ②SAP rats, ③SAP rats given the p38 MAPK inhibitor CNI-1493(10 mg/kg, iv). The SAP model was induced by the bili-pancreatic duct infusion with 5% sterile soduim taurocholate solution. Rats from each group were killed at 12 h after sham operation or SAP and Kupffer cells (KCs) were isolated. The mRNA expressions of TNF-α and IL-1β (by quantitative real-time RT-PCR) and p38 MAPK activity (by Western blot analysis) in KCs were examined. The levels of TNF-α and IL-1β in plasma were determined by ELISA.RESULTS:There was a significant acvitation of p38 MAPK in KCs harvested from SAP rats than those from sham operation rats. SAP also promoted the mRNA expressions of TNF-α and IL-1β in KCs and the plasma levels of TNF-α and IL-1β. These events were significantly inhibited by treatment with CNI-1493.CONCLUSIONS:p38 MAPK activation is one important aspect of the signaling events that may mediate the KCs production of pro-inflammatory cytokines, TNF-α and IL-1β, in SAP rats. The inhibition of the p38 MAPK may be a potential target in the prevention and treatment of SAP.     

Effects of miR-155 over-expression on expression of inflammatory factors and indolamine 2, 3-dioxygenase in microglial BV-2 cells

AIM:To explore the effect of microRNA-155(miR-155)over-expression on the expression of inflammatory factors and indolamine 2, 3- dioxygenase (IDO) in the microglial BV-2 cells. METHODS:For over-expression of miR-155, the BV-2 cells were transfected with lentiviral vector carrying mmu-miR-155. The expression of inflammatory factors was detected by cytometric bead array system (CBA). The mRNA expression of inflammatory factors and IDO was analyzed by real-time PCR. The protein levels of suppressor of cytokine signalling 1 (SOCS1), p-p38 MAPK and IDO were determined by Western blot. RESULTS:The expression of miR-155 was up-regulated in the BV-2 cells transfected with lentiviral vector carrying mmu-miR-155 compared with LPS treatment group (P<0.01). The miR-155 over-expression promoted the secretion of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemotactic protein-1 (MCP-1) and IL-10, and inhibited the secretion of IL-12. The miR-155 over-expression increased the mRNA expression of IL-6, TNF-α, IL-10 and IDO, also increased the protein levels of IDO and p-p38 MAPK, but decreased the protein expression of SOCS1 (P<0.01). LPS promoted the secretion of IL-6, TNF-α, MCP-1 and IL-12, also increased the mRNA expression of IL-6, TNF-α and IDO, meanwhile, increased the protein levels of IDO, p-p38 MAPK and SOCS1 (P<0.01). CONCLUSION:Over-expression of miR-155 promotes the secretion of related imflammatory factors and protein expression of IDO in microglial BV-2 cells mediated with SOCS1 and p38 MAPK signaling pathway.     

Effect of fucoidan on intestinal ischemia-reperfusion injury in rats

AIM:To investigate the effect and potential mechanism of fucoidan on intestinal ischemia-reperfusion (I/R) injury in rats. METHODS:Adult male Wistar rats were randomly divided into 3 groups:sham group, I/R group and Fucoidan+I/R group. Fucoidan at 160 mg/kg was intraperitoneally injected in rats of Fucoidan+I/R group 7 d prior to operation, and the equal volume of saline was intraperitoneally injected in rats of sham group and I/R group. The rats in I/R group and Fucoidan+I/R group underwent superior mesenteric artery occlusion for 1 h and then reperfusion for 2 h. Following reperfusion, the histomorphological changes of the ileum were examined by HE staining. The levels of diamine oxidase (DAO), D-lactic acid (D-LA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β were detected in the blood samples, the levels of malondialdehyde (MDA) and glutathione (GSH), the activity of superoxide dismutase (SOD) and myeloperoxidase (MPO), and the protein levels of Bax, cleaved caspase-3 and Bcl-2 were analyzed in intestinal tissue samples. RESULTS:Compared with sham group and Fucoidan+I/R group, the serum levels of DAO, D-LA, TNF-α, IL-6 and IL-1β were significantly increased in I/R group (P<0.05), Chiu's score of intestinal tissue, MDA content, MPO activity, the levels of Bax and cleaved caspase-3 protein in the intestinal tissues were also significantly increased (P<0.05), while the tissue GSH content, SOD activity, and Bcl-2 protein levels were significantly decreased (P<0.05). CONCLUSION:Fucoidan attenuates intestinal tissue damage caused by I/R, which may be related to anti-oxidation, anti-inflammatory and anti-apoptotic effects.     

Protective role of carnosine on cardiac dysfunction in type 1 diabetes mellitus rat model

AIM:To explore the effects of carnosine (CAR) on cardiac dysfunction in type 1 diabetic mellitus rats and the underlying mechanism. METHODS:The SD rats were randomly divided into 4 groups:control (C) group, control+carnosine (C+CAR) group, diabetes mellitus (DM) group and diabetes mellitus+carnosine (DM+CAR) group (n=10). The rats were sacrificed after 12 weeks. The cardiac function was assessed by ventricular cannulation. The activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were assessed by ELISA. The mRNA levels of tumor necrosis factor α(TNF-α), interleukin-1β(IL-1β) and IL-6 were measured by real-time PCR. The distribution of connexin 43 (Cx43) was examined by immunofluorescence. The protein levels of Cx43 and protein kinase C (PKC) were determined by Western blot. RESULTS:Compared with the C group, the left ventricular end diastolic pressure (LVEDP) was increased whereas the left ventricular pressure maximum rise/fall velocity (±dp/dt_max) was decreased in the DM group (P<0.01). The activity of SOD decreased while the MDA increased in the left ventricular tissues (P<0.01). The mRNA levels of TNF-α, IL-1β and IL-6 were increased (P<0.01). The Cx43 distribution was irregular. The protein levels of phosphorylated Cx43 and PKCε were elevated (P<0.01). Compared with the DM group, the cardiac function of LVEDP and ±dp/dt_max in DM+CAR group was ameliorated (P<0.01), with increased SOD activity and decreased MDA content (P<0.05). The mRNA levels of TNF-α, IL-1β and IL-6 were reduced (P<0.01). The Cx43 distribution was improved and the protein levels of phosphorylated Cx43 and PKCε were decreased (P<0.01). CONCLUSION:CAR treatment can improve the cardiac function by its anti-oxidative and anti-inflammation effects and suppression of Cx43 abnormalities through PKCε in DM rats.     

Effect of taurine on kidney injury induced by paraquat poisoning in rats

AIM:To study the effects of taurine at different doses on renal oxidative stress and inflammation induced by paraquat in rats.METHODS:Male SD rats (n=48) were randomly divided into 4 groups:negative control group,paraquat group,paraquat+low-dose taurine group,and paraquat+high-dose taurine group.The serum levels of creatinine and urea nitrogen were detected by a biochemical analyzer.The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were measured by colorimetry.The plasma concentrations of IL-6 and intercellular adhesion molecule (ICAM)-1 were detected by ELISA.Renal reactive oxygen species (ROS) was checked by fluorescence probe dihydroethidium (DHE).The protein levels of renal p-P38 MAPK,p-ERK1/2 and p-JNK were determined by Western blot.The mRNA expression of TNF-α,IL-6 and TGF-β1 was detected by real-time PCR.RESULTS:Serum creatinine and urea nitrogen increased after paraquat poisoning,and decreased after feeding with taurine in poisoned rats,with better result in high-dose taurine group.Taurine reduced the oxidative stress and inflammation in the renal tissue,and also reduced the protein levels of p-JNK,p-ERK1/2 and p-P38 in the kidney of paraquat-poisoned rats.CONCLUSION:Taurine attenuates renal injury induced by paraquat poisoning in rats.The mechanism may be related to reducing renal MAPK activity,oxidative stress and inflammatory response.     

Role of NOX1 in TNF-α-induced oxidative damage and inflammation in alveolar epithelial cells

AIM: To explore the role of NADPH oxidase 1 (NOX1) in tumor necrosis factor-α (TNF-α)-induced oxidative damage and inflammation in alveolar epithelial cells.METHODS: The mRNA and protein expression levels of NOX1 in alveolar epithelial cells after TNF-α treatment were determined by real-time PCR and Western blot. NOX1 siRNA and its negative control were transfected into the alveolar epithelial cells. After the induction of TNF-α, NOX1 levels in the cells were measured by real-time PCR and Western blot, and the content of malondialdehyde (MDA) in the cells was detected by thiobarbituric acid method. Xanthine oxidation assay was used to detect the activity of superoxide dismutase (SOD) in the cells. The contents of interleukin-4 (IL-4), IL-6 and IL-1β in cell culture medium were examined by ELISA. The rate of apoptosis was analyzed by flow cytometry. Western blot was used to detect the level of apoptotic protein cleaved caspase-3.RESULTS: The expression of NOX1 at mRNA and protein levels in TNF-α-induced cells was increased after induction (P<0.05). After transfection of NOX1 siRNA, the expression of NOX1 at mRNA and protein levels in the cell was downregulated (P<0.05). Transfection of siRNA negative control had no effect on the expression level of NOX1 in the cells. The content of MDA in the cells after TNF-α treatment was increased, the activity of SOD was reduced, the releases of IL-4, IL-6 and IL-1β by the cells were increased, and the apoptotic rate and the level of apoptotic protein cleaved caspase-3 were increased as compared with the cells that were not treated with TNF-α (P<0.05). The content of MDA in the cells with NOX1 knockdown induced by TNF-α was reduced, the activity of SOD elevated, and the releases IL-4, IL-6 and IL-1β, the apoptotic rate and the level of apoptotic protein cleaved caspase-3 decreased, as compared with the cells only treated with TNF-α induction (P<0.05).CONCLUSION: TNF-α induces the expression of NOX1 in the alveolar epithelial cells. Knockdown of NOX1 expression reduces cellular oxidative damage, releases of inflammatory factors, and cell apoptosis.     

Role of p38 MAPK signaling pathway in inflammatory effects on cerulein-induced pancreatic cells

AIM: To investigate the effect of p38 MAPK signal pathway on cerulein-treated pancreatic acinar AR42J cells.METHODS: AR42J cells were divided into control group, cerulein group (treated with 10^-8 mol/L of cerulein), and SB203580 group (treated with 10 μmol/L of SB203580 and 10^-8mol/L of cerulein).The cells were harvested 3 h after treatment.Secretion rate of amylase was measured.The translocation of p-p38 MAPK to nuclei was imaged by immunofluorescence.The protein expression levels of p-p38 MAPK and TNF-α were detected by Western blotting.The activation of NF-κB was measured by electrophoretic mobility assay.RESULTS: Compared with control group, cerulein resulted in increases in the secretion rate of amylase and protein level of TNF-α (P<0.01), as well as the expression levels of p-p38 MAPK and NF-κB (P<0.01).Cerulein induced nuclear translocation of p-p38 MAPK.Compared with cerulein group, the secretion rate of amylase and protein level of TNF-α in SB203580 group decreased significantly (P<0.01).The expression of p-p38 MAPK and NF-κB also decreased greatly (P<0.05).Nuclear translocation of p-p38 MAPK was inhibited by SB203580.CONCLUSION: The p38 MAPK pathway involves in cerulein-induced pancreatic inflammatory response via regulating NF-κB.     

Effects of PTEN on apoptosis,oxidative damage and immune inflammatory factors in myocardial H9c2 cells with anoxia/reoxygenation

AIM: To investigate the effects of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) on the apoptosis, oxidative damage and immune inflammatory factors in myocardial H9c2 cells with anoxia/reoxygenation (A/R). METHODS: The H9c2 cells were used to establish a model of A/R. The H9c2 cells were transfected with PTEN small interfering RNA (siRNA) and negative control. After A/R, the expression of PTEN at mRNA and protein levels was determined by RT-PCR and Western blot, respectively. The cell viability was measured by MTT assay. The apoptosis was analyzed by flow cytometry. Xanthine oxidase method was used to determine superoxide dismutase (SOD) activity. The content of malondialdehyde (MDA) was detected by thiobarbituric acid method. The lactate dehydrogenase (LDH) activity in the supernatant was evaluated by 4-dinitrophenylhydrazine method. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 in culture supernatant were examined by ELISA. The protein levels of cleaved caspase-3, Bax and FasL in the cells were determined by Western blot. RESULTS: After A/R, the expression of PTEN at mRNA and protein levels was significantly increased in the H9c2 cells (P<0.05). The mRNA and protein levels of PTEN were decreased significantly after transfection with PTEN siRNA (P<0.05). The viability of H9c2 cells was decreased after A/R, while the apoptotic rate was increased. The protein levels of cleaved caspase-3, Bax and FasL were increased in the cells. The MDA level was elevated, the activity of SOD was decreased, and the levels of LDH, TNF-α, IL-1β and IL-6 in the culture supernatant were increased (P<0.05). Down-regulation of PTEN partly antagonized the effects of A/R on the viability, apoptotic rate, MDA content, SOD activity, and the levels of LDH, TNF-α, IL-1β and IL-6 in culture supernatant. CONCLUSION: Down-regulation of PTEN attenuates oxidative damage induced by A/R, reduces apoptosis and secretion levels of TNF-α, IL-1β and IL-6 in the H9c2 cells.     

Effects of procyanidins on oxidative damage of osteocytes caused by TCP wear particles

AIM: To investigate the effects of procyanidins (PC) on oxidative damage of osteocytes caused by tricalcium phosphate (TCP) wear particles, and to explore the underling mechanism. METHODS: Mouse long bone osteocyte MLO-Y4 cells were treated with TCP wear particles (0.1 g/L) for 48 h to establish the model of osteocyte injuries. The MLO-Y4 cells were divided into 4 groups:control group, TCP group, PC (10 μmol/L) group and PC (50 μmol/L) group. Calcein-AM staining and MTT assay were used to observe the viability of MLO-Y4 cells. The levels of dentin matrix protein 1 (DMP-1), sclerostin (SOST) and interleukin-1β (IL-1β) in the culture media were examined by ELISA. The apoptosis of MLO-Y4 cells was analyzed by flow cytometry with Annexin V/PI double staining. The malondialdehyde (MDA) content and superoxide dismutase (SOD) activity of MLO-Y4 cells, and lactate dehydrogenase (LDH) release in the culture media were measured by chemical colorimetry. The protein levels of NOD-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), cleaved caspase-1 and IL-1β in the MLO-Y4 cells were determined by Western blot. RESULTS: Compared with control group, MLO-Y4 cell injuries, apoptosis rate and MDA level were obviously increased in TCP group, while SOD activity was significantly decreased (P<0.05) The protein levels of NLRP3, ASC, cleaved caspase-1 and IL-1β were remarkably up-regulated (P<0.05) in the MLO-Y4 cells, and the level of IL-1β and LDH release were increased in the culture media (P<0.05). Compared with TCP group, the injuries of MLO-Y4 cells, apoptosis rate and MDA level were decreased obviously (P<0.05) in PC groups, whereas SOD activity was increased (P<0.05). The protein levels of NLRP3, ASC, cleaved caspase-1 and IL-1β were down-regulated remarkably in the MLO-Y4 cells (P<0.05), and the level of IL-1β and LDH release were significantly decreased in the culture media (P<0.05). CONCLUSION: PC obviously inhibit oxidative damage of osteocytes caused by TCP wear particles, which may be related to alleviating NLRP3 inflammasome activation and pyroptosis.     

Effects of exercise training on myocardial polyamine metabolism in aged rats

AIM:To explore the effects of exercise training on myocardial polyamine metabolism in aged rats. METHODS:Wistar rats were divided into 3 groups:old+exercise group(Old+Ex), old group(Old) and young group(Young). High-performance liquid chromatography was used to test the content of myocardial polyamines(putrescine, spermidine and spermine). The activity of polyamine synthesis and catabolism rate-limiting enzyme ornithine decarboxylase(ODC) and spermidine/spermine acetyltransferase(SSAT) was analyzed by [¹⁴C] labeling. The level of malondialdehyde(MDA) and the activity of superoxide dismutase(SOD) in the myocardium were detected by colorimetric method. The levels of TNF-α and IL-1β were determined by enzyme-linked immunosorbent assay. The cardiac functions were measured by echocardiography. The changes of myocardial ultrastructure were observed under transmission electron microscope. RESULTS:(1) Compared with Young group, ODC activity decreased, SSAT activity increased, and the levels of spermidine, spermine and total polyamine were significantly decreased in Old group. SOD activity also decreased significantly, the content of MDA, TNF-α and IL-1β also increased dramatically in Old group. In the old rats, both left ventricular end-systolic diameter(LVESD) and end-diastolic diameter(LVEDD) increased, while left ventricular ejection fraction(LVEF) and fractional shortening(LVFS) decreased.(2) Compared with Old group, ODC activity increased, SSAT activity decreased, the levels of spermidine and total polyamine significantly increased, SOD activity increased significantly, and the content of MDA, TNF-α and IL-1β decreased dramatically in Old+Ex group. The functions of left ventricle also improved significantly in Old+Ex group.(3) Ultrastructural observations indicated that the myofilament and mitochondrial cristae were irregular and mitochondrial matrix density decreased in old rat heart. The cardiac sarcomere structure was clear, the mitochondrial matrix was dense and the mitochondrial cristae arranged in order in Old+Ex group. CONCLUSION:Exercise training promotes polyamine synthesis metabolism and inhibits polyamine catabolism in the heart of aged rats, thus fighting against aging-induced myocardial polyamine decrease. Exercise training also improves the capacity of anti-inflammatory and antioxidant processes of aged heart. Maintaining the appropriate levels of myocardial polyamines may be a new mechanism to delay cardiac aging.     

Dexmedetomidine attenuates acute kidney injury induced by hemorrhagic shock/resuscitation in rats

AIM: To investigate the effects of dexmedetomidine on hemorrhagic shock/resuscitation (HS/R)-induced acute kidney injury (AKI) in rats, and to explore the possible mechanisms. METHODS: Wistar rats (n=32) were randomly divided into 4 groups (n=8):normal saline control group (NS group), dexmedetomidine group (D group), HS/R group and HS/R+D group. The animals were sacrificed at 6 h after resuscitation. The levels of serum creatinine (Cr) and blood urine nitrogen (BUN) were examined. The kidneys of all rats were removed for evaluation of histological characteristics, and the levels of malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and superoxide dismutase (SOD) were measured. The expression of nuclear factor-κB (NF-κB) and hemeoxygenase-1 (HO-1) was determined by Western blot. RESULTS: Compared with NS group, the levels of Cr, BUN, MDA, TNF-α and IL-1β were obviously increased in HS/R group, which were obviously decreased in HS/R+D group (P<0.05). Compared with NS group, the SOD activity was obviously decreased in HS/R group, which was obviously increased in HS/R+D group (P<0.05). Compared with NS group, the protein expression of NF-κB was obviously increased in HS/R group, which was obviously decreased in HS/R+D group (P<0.05). Compared with NS group, the protein expression of HO-1 was increased in HS/R group. Compared with HS/R group, the protein expression of HO-1 was obviously increased in HS/R+D group. Compared with NS group, HS/R induced marked kidney histological injury, which was less pronounced in HS/R+D group.CONCLUSION: Dexmedetomidine effectively protects rats against AKI caused by HS/R, and its mechanism may be associated with the increase in HO-1 expression and the inhibition of NF-κB expression.     

Protective effects of glutamine pretreatment on occludin protein in rats with intestinal ischemia-reperfusion injury

AIM: To determine the effects of glutamine(Gln) pretreatment on occludin protein in the rats with intestinal ischemia-reperfusion(I/R) injury. METHODS: Male Wistar rats(n=30) were randomly divided into 3 groups(n=10):sham group, I/R group and Gln pretreatment group. The rats in Gln pretreatment group were pretreated with Gln at dose of 1 g·kg^-1·d^-1 by orogastric route for 7 d, and those in the other 2 groups were pretreated with the same volume of normal saline. Intestinal I/R was induced by 30-min occlusion of the superior mesenteric artery followed by 24 h of reperfusion. After the operation, the levels of IL-10, IL-2, TNF-α, SOD and MDA were measured. The occludin protein was determined by the methods of immunohistochemistry and Western blotting. RESULTS: The occludin protein level in I/R group was significantly lower than that in sham group and Gln group(P<0.05). The levels of MDA and TNF-α in I/R group were significantly higher than those in sham group and Gln group(P<0.05). The levels of SOD, IL-10 and IL-2 in I/R group were significantly lower than those in sham group and Gln group(P<0.05). CONCLUSION: Glutamine has a protective effect on occludin protein in intestinal ischemia-reperfusion injury. The mechanism may be rela-ted to oxidative stress response and inflammatory inhibition.     

Knock-down of TLR4 expression reduces secretion of inflammatory factors in LPS-induced pancreatic acinar AR42J cells

AIM:To study the effect of Toll-like receptor 4 (TLR4) on the secretion of inflammatory factors in the pancreatic acinar AR42J cells induced by lipopolysaccharides (LPS). METHODS:The rat pancreatic acinar AR42J cells were treated with LPS. The expression of TLR4 at mRNA and protein levels was determined by real-time PCR and Western blot. The lentivirus carrying TLR4 small interfering RNA (siRNA) was used to infect the AR42J cells. Under LPS stimulation, the interference efficacy was measured by real-time PCR and Western blot. The cell viability was measured by MTT assay, and the leakage rate of lactate dehydrogenase (LDH) was examined by dinitrophenylhydrazine method. The releases of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the cell culture medium were detected by ELISA, and the malondialdehyed (MDA) content in supernatant was measured by thiobarbituric acid method. The activity of superoxide dismutase (SOD) in the supernatant was determined by xanthine oxidation, and the activity of glutathione peroxidase (GSH-Px) and catalase (CAT) was detected by colorimetry. RESULTS:The expression of TLR4 at mRNA and protein levels in LPS-treated AR42J cells was significantly increased (P<0.05). Infection with TLR4 siRNA-carrying lentivirus significantly inhibited the expression of TLR4 at mRNA and protein levels in the AR42J cells under LPS stimulation(P<0.05). The viability of AR42J cells was decreased after LPS treatment. The leakage rate of LDH was increased, the levels of IL-1β and TNF-α secreted by the AR42J cells were increased, the content of MDA was increased in the supernatant, and the activity of SOD, GSH-Px and CAT was reduced (P<0.05). After knock-down of TLR4 expression, the viability of AR42J cells was increased under LPS stimulation, the LDH leakage rate, secreted levels of IL-1β and TNF-α, and the content of MDA in cell culture medium were decreased, and the SOD, GSH-Px and CAT levels were increased (P<0.05). CONCLUSION:LPS induces the expression of TLR4 in the pancreatic acinar AR42J cells. Knock-down of TLR4 expression reduces the secretion of inflammatory factors IL-1β and TNF-α, and attenuates the oxidative damage in pancreatic acinar AR42J cells induced by LPS.     

Dexmedetomidine attenuates acute alcoholic hepatic injury in mice

AIM: To investigate the effects of dexmedetomidine (DEX) on acute alcoholic hepatic injury in mice and to explore the possible mechanisms. METHODS: Kunming mice (n=50) were randomly divided into 5 groups (n=10): normal saline control (NS) group, acute alcoholic hepatic injury model (E) group, low-dose (10 μg/kg) DEX (E+L) group, medium-dose (50 μg/kg) DEX (E+M) group and high-dose (100 μg/kg) DEX (E+H) group. The animals were sacrificed at 6 h after gavage of alcohol or normal saline. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), malondialdehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD) were measured. The livers were removed for evaluation of histological characteristics and determining the content of tumor necrosis factor-α (TNF-α) amd interleukin-1β (IL-1β) in the liver tissues by ELISA. The expression levels of cytochrome P450 2E1 (CYP2E1) and nuclear factor-κB (NF-κB) in the liver tissues were evaluated by Western blot. RESULTS: Compared with NS group, the levels of ALT, AST and TG were obviously increased in E group, which were obviously decreased in E+M and E+H groups. Compared with NS group, the levels of TNF-α, IL-1β and MDA were obviously increase in E group, which were obviously decreased in E+M and E+H groups. Compared with NS group, the activity of SOD and the content of GSH were obviously decreased in E group, which were obviously increased in E+M and E+H groups. Compared with NS group, the expression of CYP2E1 and NF-κB was obviously increase in E group, which was obviously decreased in E+M and E+H groups. Compared with NS group, ethanol induced marked liver histological injury, which was less pronounced in E+M and E+H groups. CONCLUSION: DEX has a protective effect on mouse liver with acute alcoholic injury by the involvement in the processes of antioxidation and antiinflammation, and its mechanism may be associated with the inhibition of CYP2E1 and NF-κB expression.     

Erianin induces apoptosis of human lung cancer A549 cells via ROS/p38 MAPK pathway

AIM:To investigate the effect of erianin on the viability and apoptosis of human lung cancer A549 cells and its possible mechanism. METHODS:A549 cells and BEAS-2B cells were cultured in vitro and treated with erianin at 10, 20, 40, 80 and 160 nmol/L for 48 h. The cell viability was measured by CCK-8 assay. The apoptosis and reactive oxygen species (ROS) were analyzed by flow cytometry. The activity of superoxide dismutase (SOD) was detected by WST-8 method, and the content of malondialdehyde (MDA) was detected by barbituric acid method. The protein levels of nuclear factor E2-related factor 2 (Nrf2), NAD(P)H:quinone oxidoreductase-1 (NQO1), heme oxygenase-1 (HO-1), p38 MAPK, p-p38 MAPK, caspase-3 and cleaved caspase-3 were determined by Western blot.RESULTS:Erianin remarkably reduced the viability of A549 cells in a dose-dependent manner (P<0.05) with IC₅₀ at 52.64 nmol/L. Erianin also induced apoptosis (P<0.05), increased ROS level and MDA content (P<0.05), diminished SOD activity (P<0.05), and down-regulated the protein levels of Nrf2, NQO1 and HO-1 (P<0.05), in a dose-dependent manner. Meanwhile, erianin up-regulated the levels of p-p38 MAPK and cleaved caspase-3 (P<0.05), and these effects were inhibited by N-acetyl-L-cysteine and SB203580 (P<0.05).CONCLUSION:Erianin may induce apoptosis of human lung cancer A549 cells most likely via inhibiting SOD activity and down-regulating the protein levels of Nrf2, NQO1 and HO-1, thus resulting in an increase in ROS and activation of p38 MAPK.     

Role of p38 MAPK-HSP27 signaling pathway in rat acute lung injury induced by lipopolysaccharide

AIM: To observe the role of p38 mitogen-activated protein kinase (p38 MAPK)-heat-shock protein 27 (HSP27) signaling pathway in lipopolysaccharide-induced acute lung injury (ALI) in rats. METHODS: Wistar rats were randomly divided into control group, ALI group and ALI+SB203580 group. After the experimental model was established, the rats were sacrificed. The pathological changes of the lung and the changes of F-actin and G-actin in the endothelial cells were observed. The ratio of wet weight to dry weight (W/D) of the lung tissues was measured. The protein levels in bronchoalveolar lavage fluid (BALF) were detected. The levels of IL-6 and TNF-α in serum and BALF were tested. The concentrations of p-p38 and p-HSP27 in the lung were determined. RESULTS: In ALI group, the protein levels in BALF and W/D ratio of the lung increased significantly at 2 h. The levels of TNF-α and IL-6 in serum and BALF began to increase at 2 h, which had significant difference as compared with control group. Aleolar epithelial swelling, alveolar walls widening, alveolar interstitial and cavity edema, and the exudation of alveolar inflammation cells, red blood cells and protein were observed in ALI group. The protein levels in BALF and W/D ratio of the lung in ALI+SB203580 group were much less than those in ALI group. The exudation of alveolar inflammation cells, red blood cells and protein, and the interstitial and alveolar edema in ALI+SB203580 group alleviated as compared with ALI group. The expression of p-p38 MAPK and p-HSP27 in the lung at 2 h in ALI group was higher than that in control group. F-actin expression in ALI group obviously increased than that in control group at time points of 0 h and 8 h. Compared with ALI group, the expression of p-HSP27 and F-actin in ALI+SB203580 group was reduced. CONCLUSION: Lipopolysaccharide activates p38 MAPK-HSP27 signaling pathway and induces lung injury. Blockage of p38 MAPK-HSP27 signaling pathway may reduce lung injury.     

Ulinastatin protects rat pulmonary tissues from paraquat-induced acute injury

AIM: To investigate the protective effects of ulinastatin on the rats with paraquat-induced acute lung injury and its mechanisms. METHODS: The Wistar rats (n=108) were randomly divided into control group, paraquat group and ulinastatin group. The rats in paraquat group and ulinastatin group were given paraquat by gavage, while the rats in control group were given sterile saline by gavage. The rats in ulinastatin group were also given ulinastatin treatment. The serum levels of MDA, SOD, IL-6, IL-10 and TNF-α were measured after 1 d, 3 d, 7 d, 14 d, 21 d and 28 d. The expression levels of p38 MAPK, MMP-2 and TIMP-1 in the lung were also measured. RESULTS: The levels of SOD in 1 d, 3 d and 7 d in paraquat group and ulinastatin group were significantly lower than those in control group (P<0.01). The level of SOD in ulinastatin group was significantly higher than that in paraquat group (P<0.05). The levels of MDA, IL-6, IL-10 and TNF-α in 1 d, 3 d and 7 d in paraquat group and ulinastatin group increased compared with control group (P<0.01), and those in ulinastatin group were significantly lower than those in paraquat group (P<0.05). The levels of p38 MAPK and TIMP-1 in 1 d, 3 d, 7 d, 14 d, 21 d and 28 d in paraquat group and ulinastatin group were higher than those in control group (P<0.01), and those in ulinastatin group was significantly lower than those in paraquat group (P<0.05). The level of MMP-2 in 1 d, 3 d, 7 d, 14 d and 21 d in paraquat group and ulinastatin group increased compared with control group (P<0.01), and that in ulinastatin group was significantly lower than that in paraquat group (P<0.05).CONCLUSION: Ulinastatin protects the lung tissues of rats from paraquat-induced acute lung injury by inhibiting p38 MAPK signaling pathway and ameliorating inflammatory and oxidative responses.     

Poly(adenosine diphosphate ribose) glycohydrolase regulates apoptosis-inducing factor and inflammatory factors in rat hippocampus after seizures

AIM: To investigate the effects and molecular mechanisms of poly(adenosine diphosphate ribose) glycohydrolase (PARG) on rat hippocampus neurons after seizures and to study the effects of gallotannin on the expression of apoptosis-inducing factor (AIF), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in rat hippocampus after seizures. METHODS: Seizures were induced by kainic acid (KA). The damage of hippocampus neurons was evaluated by Nissl staining. The protein expression levels of poly(adenosine diphosphate ribose) (PAR), AIF, IL-1β and TNF-α were detected by Western blotting analysis. RESULTS: The number of damaged hippocampal pyramidal neurons in gallotannin-treated group was significantly lower than that in KA-treated group (P<0.05). The expression of PAR was increased in gallotannin-treated group compared with KA-treated group(P<0.05).AIF in mitochondrial fraction increased and its accumulation in nucleus fraction decreased in gallotannin-treated group compared with KA-treated group (P<0.05). In addition, gallotannin significantly decreased the protein expression of IL-1β and TNF-α, which were obviously increased in hippocampus after seizures (P<0.05). CONCLUSION: PARG inhibition by gallotannin has the neuroprotective effect on the damage of hippocampal neurons induced by seizures. In addition, gallotannin suppresses the translocation of AIF from mitochondria to nucleus and the expression of IL-1β and TNF-α in rat hippocampus after seizures.