共查询到20条相似文献，搜索用时 453 毫秒
1.
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). 相似文献
2.
AIM: To examine the role of glucocorticoid receptor (GR) in regulation of lipopolysaccharide (LPS)-induced lung injury. METHODS:Male Sprague-Dawley rats were divided into six groups randomly: control group (n=6), LPS group (n=6 each), Dex+LPS group (n=6 each), RU486 group (n=6), RU486+LPS group (n=6 each) and RU486+Dex+LPS group (n=6 each). All groups were subjected into 1 h, 3 h, 6 h and 12 h time point subgroups after LPS administration, except of control group and RU486 group. The concentrations of TNF-α and IL-6 in bronchoalveolar lavage fluids (BALF) were detected by ELISA. The histopathologic changes of lung tissues, the activation of p38MAPK and the expression of MKP-1 in lung tissue were also observed. Further, to confirm the role of GR in this model, the mortality of rats in LPS group vs RU486+LPS group and in Dex+LPS group vs RU486+Des+LPS group was compared. RESULTS: LPS induced lung injury and the secretions of TNF-α and IL-6 in BALF, which were significantly enhanced by pretreatment of RU486 (P<0.05). RU486 pretreatment also significantly increased the LPS-induced lethality (P<0.05). Dexamethasone attenuated LPS-induced lung damage, cytokine release and mortality rates, and the protective effects might be mediated by GR. Western blotting analysis showed dexamethasone inhibited the phosphorylation of p38MAPK in lung tissues by induction of MKP-1, and these actions were also GR dependent. CONCLUSION: GR plays an essential role in regulation of LPS-induced acute lung injury. Anti-inflammatory effects of hormone-activated GR may be mediated by inhibition of p38MAPK phosphorylation/activation, which is associated with the induction of MKP-1. 相似文献
3.
LI Mei-ai WANG Hua-dong LU Da-xiang WANG Yan-ping QI Ren-bin YAN Yu-xia FU Yong-mei LI Chu-jie 《园艺学报》2006,22(5):987-991
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. 相似文献
4.
AIM: To investigate the role of epidermal growth factor receptor (EGFR) in the secretion of inflammatory cytokines in human bronchial epithelial BEAS-2B cells induced by Klebsiella pneumoniae (KP) capsular polysaccharide (CPS). METHODS: KP was cultured in vitro , and the CPS was extracted. The BEAS-2B cells were stimulated with CPS at different concentrations, and the levels of tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) in the supernatant were measured by ELISA. The phosphorylation level of EGFR was detected by Western blot at different time points after stimulation. After pretreatment of the BEAS-2B cells with EGFR inhibitor AG1478, the phosphorylation level of ERK was detected by Western blot, the nuclear translocation of P65 was detected by indirect immunofluorescence, and the levels of TNF-α and IL-8 in the supernatant of the cells were measured. Finally, the levels of TNF-α and IL-8 in the culture supernatant of CPS-stimulated cells were detected by ELISA after pretreated with ERK inhibitor PD98059 and NF-κB inhibitor PDTC. RESULTS: Exposure to CPS at 10 mg/L for 12 h significantly induced the BEAS-2B cells to secret TNF-α and IL-8. The phosphorylation levels of EGFR and ERK and the nuclear translocation of p65 in the BEAS-2B cells were significantly increased after CPS stimulation (P <0.05). The phosphorylation level of ERK and the nuclear translocation of p65 were significantly reduced in the cells pretreated with EGFR inhibitor AG1478. Furthermore, the levels of TNF-α and IL-8 in the supernatant were significantly decreased after pretreated with the inhibitors of EGFR, ERK and NF-κB. CONCLUSION: Klebsiella pneumonia capsular polysaccharide activates the ERK and NF-κB signaling pathways via EGFR, and then induced the secretion of inflammatory cytokines TNF-α and IL-8 in the bronchial epithelial cells, indicating that EGFR may be a key factor in the inflammatory response induced by KP infection. 相似文献
5.
AIM: To observe the effect of heat shock protein 70(HSP70) expression induced by glutamine on Escherichia coli lipopolysaccharides(LPS)-induced vascular hyporeactivity in rats.METHODS: Twenty four healthy male Sprague-Dawley rats were randomly divided into: the control group (n=8);LPS shock group (n=8);glutamine(Gln) treated group (Gln 0.75 g·kg-1 iv,n=8).6 h after LPS shock,phenylephrine (PE,0.5-2.5 μg·kg-1 ) was applied intravenously to all groups and the percentage increase in mean arterial pressure(MAP) was detected,respectively.The concentration-response curves of aorta rings were obtained by cumulative addition of phenylephrine (PE),and PE Emax,EC50 were calculated.The blood concentration of malondialdehyde (MDA),TNF-α and IL-6 were assayed in all groups 30 min and 360 min after LPS shock,respectively.The expressions of HSP70 from heart and aorta were also assayed after 6 h LPS shock.RESULTS: The MAP level induced by PE significantly decreased by 51.4% in LPS shock group compared with the control (P<0.05).However,PE induced MAP level increased by 17.5% in Gln group compared with LPS shock group (P<0.05).Emax and EC50 to PE were significant reduced in LPS shock group compared with control group (P<0.05),but significantly improved in Gln group (P<0.05).The expressions of HSP70 from heart and aorta were much higher in Gln group than those in LPS shock group (P<0.05).The blood concentrations of TNF-α,IL-6 and MDA were much lower in Gln group than those in LPS shock group.CONCLUSION: Glutamine effectively improves α-adrenergic receptor-mediated vascular reactivity through inducing the expression of HSP 70,reducing inflammatory cytokine release and peroxide biosynthesis in LPS shock.These results suggest that glutamine have potential beneficial therapeutic effect for septic shock patients. 相似文献
6.
AIM: To evaluate the therapeutic efficacy of intratracheal instillation of porcine pulmonary surfactant (PPS) in rats with lipopolysaccharides (LPS)-induced early-stage ALI in this study.METHODS: SD rats weighing 200 g-300 g were randomly divided into 4 groups: LPS (1.5 mg·kg-1)+saline,LPS+PPS 100 mg·kg-1,LPS+PPS 150 mg·kg-1,LPS+PPS 200 mg·kg-1.The PaO2 and PaCO2,as well as survival rate of rats were examined for 6 h after the start of PPS-instillation.Then,rats were killed and lungs were immediately removed for lung index (LI) and histological analysis.The bronchoalveolar lavage fluid (BALF) was collected for measurement of total protein (TP) contents,TNF-α level and white blood cell(WBC) numbers.RESULTS: Significantly increased PaO2,reduced mortality rate,decreased total protein and TNF-α contents in BAL,as well as lung index and meliorated histological appearance were observed in three PPS-treated groups compared with group given saline after LPS (P<0.05).The therapeutic effect in PPS150 and PPS200 groups was better than that in PPS100 group.CONCLUSION: Intratracheal PPS instillation provides protective effect on acute lung injury in rats induced by LPS. 相似文献
7.
DU Hui-bo SONG Wen ZHANG Li-min XING Li-qiang ZHANG Hui ZHAO Zi-gang NIU Chun-yu 《园艺学报》2014,30(4):686-692
AIM: To observe the effects of normal mesenteric lymph (NML) on the lung, heart and liver injuries and the phosphorylation levels of p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK) 1/2 and c-Jun N-terminal kinase (JNK) in the mice with endotoxic shock (ES). METHODS: The NML was drained form health male BALB/c mice for the intervention of ES after the removal of cellular constituent. Lipopolysaccharide (LPS, 35 mg/kg) was intraperitoneally injected into the mice for the establishment of ES model. After 60 min of LPS injection, the administration of NML (1/15 of whole blood volume) was performed through the femoral artery in NML+ES group. Meanwhile, the mean arterial pressure (MAP) was monitored during the experiment. At 6 h after intraperitoneal injection of LPS or the corresponding time point, blood samples were harvested from the heart through apical centesis for determination of the biochemical indexes to reflect myocardial and hepatocyte injuries. Simultaneously, the lung, heart and liver tissue specimens from a fixed location were harvested for the observation of histomorphology and the measurement of phosphorylation levels of p38 MAPK, ERK1/2 and JNK. RESULTS: Compared with sham shock (SS) group, MAP in ES group and NML+ES group remarkably decreased at multiple time points after intraperitoneal injection of LPS. However, MAP in NML+ES group at 80 min, 90 min, 190 min, 210 min, 240 min, 250 min, 340 min, 350 min, and 360 min were significantly increased compared with ES group. There were normal structures in the lung, liver and myocardium of the mice in SS group, while the morphological damages of these tissues appeared in ES group. Meanwhile, the damages were attenuated in the mice of NML+ES group. The activities of AST, ALT and CK-MB in the plasma in ES group were remarkably higher than those in SS group. The CK-MB activity in NML+ES group was also increased compared with SS group, and the activities of AST and LDH-1 were lower than those in ES group. At 6 h after LPS injection, the phosphorylation levels of p38 MAPK, ERK1/2 and JNK in the lung tissues were remarkably increased. Meanwhile, no statistical difference of these indexes between the myocardial and hepatic tissues was observed. NML intervention decreased the phosphorylation levels of p38 MAPK in the lung tissues, and p38 MAPK, ERK1/2 and JNK in the myocardial tissues. CONCLUSION: The NML administration alleviates multi-organ injuries and reduces the phosphorylation level of p38 MAPK in the lung tissues in the mice subjected to ES. 相似文献
8.
LIU Zuo-jin LIU Chang-an YOU Hai-bo CHEN Xian-feng LI Xu-hong GONG Jian-ping 《园艺学报》2006,22(11):2123-2126
AIM:To observe the changes of interleukin-1 receptor associated kinase-4 (IRAK-4) in ischemia/reperfusion (I/R) liver pretreated with lipopolysaccharide (LPS) and to explore the protective mechanisms of LPS pretreatment against hepatic I/R injury. METHODS:Male Sprague-Dawley rats, weighing 240-280 g, were divided into three groups:control, ischemia/reperfusion group (I/R group) and LPS-pretreated group (LPS group). On the first day, LPS group received 0.1 mg/kg LPS via the tail vein, followed by 0.5 mg/kg on the 2nd, 3rd, 4th and 5th day. I/R group received the equivalent volumes (0.5 mL) of sterile PBS. Experiments of I/R injury was induced by temporary ischemia of the left lateral liver lobe for 90 min followed by 3 h reperfusion on 2 days after the last LPS treatment. At 0 min, 60 min and 180 min after reperfusion, the expression of IRAK-4 gene and protein level were determined by RT-PCR and Western blotting. The activity of NF-κB and the serum TNF-α level were also detected by ELISA. RESULTS:Although the level of IRAK-4 gene and protein were higher in the LPS group than that in I/R group and control group (P<0.01), no difference of the activities of NF-κB and the TNF-α level was observed between the LPS group and I/R group (P>0.05) at 0 min after reperfusion. However, all those indexes were evidently lower in the LPS group than those in I/R group (P<0.01) at 60 min and 180 min after reperfusion. CONCLUSION:This data suggests that the protective effects induced by LPS pretreatment against hepatic I/R injury may be via down-regulation of IRAK-4 expression. 相似文献
9.
AIM: To study the effects of thalidomide on the expressions of nuclear factor κB (NF-κB) and tumor necrosis factor-α (TNF-α) in rat liver fibrosis.METHODS: The fibrosis of rat liver was induced by intraperitoneal injection of carbon tetrachloride thrice weekly.Meanwhile thalidomide (10 mg·kg-1·d-1 or 100 mg·kg-1·d-1) was given daily by the intragastric route for 8 weeks.Serum alanine aminotransferase (ALT),aspartate aminotransferase (AST),prealbumin (PA),hyaluronic acid (HA) and laminin (LN),and hydroxyproline (HYP) contents in the liver,NF-κB p65 and α-smooth muscle actin (α-SMA) protein in the liver,IκBα and TNF-α protein in cytoplasm and NF-κB p65 protein in nucleus and TNF-α mRNA levels in the liver were studied.RESULTS: Compared with the model group,the Knodell score,serum ALT,AST,HA,LN levels and HYP contents in liver,NF-κB p65 protein in nucleus and α-SMA protein in the liver,and TNF-α mRNA and protein in the liver of rats given high dose of thalidomide were decreased significantly (P<0.01).Meanwhile PA level and IκBα protein in cytoplasm were elevated significantly (P<0.01).CONCLUSION: Thalidomide exerts its effect on the down-regulation of NF-κB-induced TNF-α via inhibiting dissociation and degradation of IκB and prevents liver fibrosis in rats. 相似文献
10.
AIM: To investigate the role of MEK1/2, a subfamily of mitogen activated protein kinase-kinase (MAPKK), in expression of intercellular adhesion molecule-1 (ICAM-1) induced by lipopolysaccharide (LPS) in human umbilical vein endothelial cells (HUVECs). METHODS: Expression levels of ICAM-1 mRNA and its protein were assayed using RT-PCR and Western blotting, respectively, in HUVECs pretreated with different concentrations of LPS for different times with or without PD98059, a specific inhibitor of MEK1/2. RESULTS: LPS up-regulated the expression of ICAM-1 mRNA and its protein in HUVECs in a concentration- and time-dependent manners. The expression levels of ICAM-1 mRNA and its protein began to elevate at 2 h after LPS treatment, and reached nearly a peak value at 6 h after LPS (100 μg·L-1) treatment. PD98059 (10 μg·L-1) significantly inhibited LPS-induced expression of ICAM-1 mRNA and protein, the expression inhibitory rates of which were 54.4% and 44.9%, respectively (P<0.01). CONCLUSION: Modulation of MEK1/2 signaling pathway might be a new and useful strategy for the prevention and treatment of vascular endothelial injury induced by LPS. 相似文献
11.
ZHANG Xiao-ling XIAO Sheng-jun RONG Ming-zhi SHEN Jie ZHANG Ke-feng GAO Ya ZHU Hua 《园艺学报》2010,26(5):952-955
AIM: To investigate the liver protective effects of polysaccharides of Dicliptera chinensis (L.) Nees. on fulminant hepatitis caused by D-galactosamine (D-GalN)/lipopolysaccharide (LPS) in rats. METHODS: Male Wistar rats were divided into 4 groups (12 rats in each group), including normal control group, GalN/LPS-treated group, and two Dicliptera chinensis (L.) Nees. polysaccharides-treated groups (150 mg/kg, 300 mg/kg, ig, respectively). The Dicliptera chinensis (L.) Nees. polysaccharides and controlled normal saline (NS) were administered once 1 d for 6 d. One hour after the latest administration, all animals except for the animals in control group were administered with D-GalN (500 mg/kg, ip), then treated with LPS 1 h later. The mortality was observed at 6 h and 12 h after modeling. The serum samples were collected at 6 h and 12 h in the survival rats by retro-orbital sampling. All samples were measured for ALT, AST, TNF-α and IL-1β. The samples collected at 12 h were also detected for NO. At 12 h, all survival rats were sacrificed and liver section was prepared for histological evaluation. RESULTS: Pretreatment with polysaccharides of Dicliptera chinensis (L.) Nees. significantly improved the histopathological changes and attenuated GalN/LPS-induced severe hepatotoxicity as evidenced by decrease in the levels of ALT and AST. The polysaccharides of Dicliptera chinensis (L.) Nees. inhibited the elevated levels of TNF-α, IL-1β and NO. CONCLUSION: Using Dicliptera chinensis (L.) Nees. polysaccharides as anti-inflammatory reagent provides a definite protective way against fulminant hepatitis caused by GalN/LPS in rat. 相似文献
12.
ZHANG Hao-qing ZOU Peng WANG Hua-dong LU Da-xiang LI Mei-ai QI Ren-bin WANG Yan-ping FU Yong-mei 《园艺学报》2007,23(3):495-499
AIM:To investigate the mechanisms by which berberine attenuates LPS-induced acute lung injury, and provide a new strategy for the treatment of the lung injury due to LPS. METHODS:BALB/c mice were randomly assigned into three groups (control, LPS group, and berberine treatment group). Mice were administered intragastrically with distilled water (0.1 mL/10 g) or neutral sulfate berberine (50 mg/kg) once a day for 3 days, 1 h after intragastrical treatment on day 3, LPS (20 mg/kg) or normal saline was injected intraperitoneally (ip). All animals were sacrificed 12 h after LPS injection, the left lung tissue sections were prepared for histology analysis and the right lung were used to determine the ratio of wet to dry lung tissue weight (W/D). In another experiment, bronchoalveolar lavage fluid (BALF) was collected, and then the total protein content, and the amounts of white blood cells (WBC) and polymorphonuclear neutrophils (PMN) in BALF were determined. Furthermore, the phosphorylation of cytosolic phospholipase A2 (cPLA2) was detected with immunohistochemical analysis by using phospho-cPLA2(Ser505) antibody, and the contents of thromboxane B2 (TXB2) in BALF, malondialdehyde (MDA) in the lungs, and activity of superoxide dismutase (SOD) in lung tissues were also determined.RESULTS:LPS induced acute lung injury, activated cPLA2, and increased TXB2 content in the BALF and MDA level in the lung tissue. The pretreatment with berberine significantly attenuated lung injury, lung edema and protein leakage induced by intraperitoneal injection of LPS. The expression of phospho-cPLA2 in the lung tissues and TXB2 content in the BALF in the berberine treatment group were lower than those in LPS group (P<0.05). In addition, the content of MDA in the lung tissue was lower in the berberine treatment group than LPS group (P<0.05), but there was no significant difference in activity of lung SOD between the berberine treatment and LPS group (P>0.05). CONCLUSION:Pretreatment with berberine remarkably reduces the LPS-induced lung injury, which is, at least in part, through inhibiting phosphorylation of cPLA2 and decreasing lipid peroxidation. These findings provide a new strategy for the prevention and treatment of LPS-induced acute lung injury. 相似文献
13.
AIM: To investigate the effect of recombinant human interleukin-10 (rhIL-10) on IL-6 and TNF-α levels in serum and liver of mice exposed to lipopolysaccharide (LPS). METHODS: rhIL-10 was prepared by using genetic engineering technology. Mice were intraperitoneally with 500 μg of LPS, and then were treated intravenously with various dosages of rhIL-10. The levels of IL-6 and TNF-α in hepatic tissue and serum were determined by ELISA at 12 h, 24 h, 48 h and 72 h post rhIL-10 treatment. RESULTS: rhIL-10 markedly inhibited the increase in IL-6 and TNF-α levels in hepatic tissue and serum at 12 h after rhIL-10 treatment in LPS-challenged mice, and the inhibition effect was significant at 24-48 h after rhIL-10 treatment （P＜0.05）. CONCLUSION: rhIL-10 can inhibit the increase in IL-6 and TNF-α levels induced by LPS in mice. 相似文献
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15.
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. 相似文献
16.
AIM: To investigate the effects of nitric oxide (NO) and NO synthase (NOS) inhibitor NG-nitro-L arginine (L-NA) on LPS induced-lung injury in rats. METHODS: Forty healthy male SD rats, weighing 300±20 g, were used. The animals were anesthetized with 20% urethane 1 g·kg-1. Common carotid artery (CAA) and jugular vein were exposed through a median incision in the neck. Mean arterial pressure (MAP) was measured through a pressure transducer connected with intubation of CAA. The animals were randomly divided into five groups: group 1: control; group 2: LPS (5 mg·kg-1, iv); group 3: high dose L-NA (20 mg·kg-1 intraperitoneal injection, ip); gropu 4: middle dose L-NA (10 mg·kg-1, ip); group 5: low dose L-NA (5 mg·kg-1, ip). Group1 : 0.9% saline solution was given and the animals were killed 6 h after the saline solution. Gruop 2: saline solution was given 3 h after LPS and the animals were killed 3 h after administration. Group 3, 4 and 5: L-NA was given 3 h after LPS iv and the animals were killed 3 h after administration, respectively. The pulmonary was removed immediately. The pulmonary coefficient and water content in pulmonary tissue were calculated (%). The NO2-/NO3- content in plasma, MDA content and NOS, SOD activity in the pulmonary tissue were measured. RESULTS: L-NA significantly decreased pulmonary coefficient and water content in pulmonary tissue and ameliorated LPS induced lung injury. The effect in high dose group was better than that in low dose group. L-NA significantly decreased NO2-/NO3- content in plasm, decreased MDA content and inhibited NOS activity and enhanced SOD activity in the pulmonary tissue. CONCLUSION: It may be concluded that L-NA has a beneficial effect on lung injury induced by LPS. 相似文献
17.
ZHANG Yi-min YE Ren-gao LI You-ji LI Xiao-yan WANG Chang-yun YU Xue-qing DONG Xiu-qing 《园艺学报》2007,23(9):1796-1800
AIM: To study the effects and mechanism of recombinant human defensin α1 on cell proliferation in cultured rat glomerular mesangial cells.METHODS: The influences of defensin α1 at various concentrations on rat 1097 mesangial cell line cultured in vitro were evaluated with MTT assay.The different concentrations of U0126,signal-regulated protein kinase (MEK) inhibitor,were added into the culture mediums of mesangial cells to do blocking test.Incubated with a final concentration of 3 mg/L defensin α1,the phosphorylation of extracellular signal regulated kinase (ERK)1/2 and type IV collagen of mesangial cells in different times were evaluated by Western blotting.RESULTS: Defensin α1 at 3-20 mg/L enhanced proliferation of rat glomerular mesangial cells.The incubation times for the maximum effect on proliferation was 12 h (P<0.01),whereas defensin α1 concentration >20 mg/L decreased cell proliferation.The cell proliferation induced by defensin α1 was inhibited by U0126.Stimulation of the cells with defensin α1 at concentration of 3 mg/L for 5 minutes induced a maximum effect on a ratio of phosphorylation of ERK1/2 to total ERK.After 12 h incubation with defensin α1,an increase in type IV collagen was observed by Western blotting and continued to increase at 24 h and 48 h (P<0.01).CONCLUSION: Defensin α1 enhances rat glomerular mesangial cell proliferation and induces type IV collagen production by MAPK signaling pathway. 相似文献
18.
AIM To investigate the protective effects of gabexate mesilate （GM） on blood-brain barrier （BBB） permeability in rat model with cerebral ischemia-reperfusion （I/R）. METHODS Adult male SD rats （n =180） were randomly divided into sham group, I/R group, nimodipine （NMP; 2 mg·kg-1·d-1） group and GM （5, 10 and 20 mg·kg-1·d-1） groups （n =30 in each group）. The rat model of cerebral I/R was established by blocking the middle cerebral artery with thread plug for 2 h. Ten min before modeling, the drugs were given intraperitoneally. The nerve function was detected by Longa scoring method. The permeability of BBB was measured by Evans blue permeation method, and the brain water content was measured by dry-wet weight method. The activity of superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px）, and the content of malondialdehyde （MDA） in brain tissue were determined by biochemical analysis. The content of tumor necrosis factor-α （TNF-α）, interleukin-1β （IL-1β） and IL-6 was measured by ELISA. The mRNA expression of matrix metalloproteinase-2 （MMP-2）, MMP-9 and nuclear factor-κB （NF-κB） was detected by RT-PCR. The protein levels of MMP-2, MMP-9 and NF-κB were determined by Western blot. RESULTS Compared with I/R group, the Longa score, permeability of Evans blue and brain water content of the rats in GM （10 and 20 mg·kg-1·d-1） and NMP （2 mg·kg-1·d-1） groups were decreased. The activity of SOD and GSH-Px was increased, while the content of MDA was decreased. The content of TNF-α, IL-1β and IL-6 was decreased, and the mRNA and protein expression levels of MMP-2, MMP-9 and NF-κB were significantly down-regulated. Compared with NMP （2 mg·kg-1·d-1） group, the Longa score and permeability of Evans blue were decreased in GM （20 mg·kg-1·d-1） group, the activity of SOD was increased, and the content of MDA and TNF-α was decreased. The mRNA and protein expression levels of MMP-2, MMP-9 and NF-κB were down-regulated. All of the differences were significant （P <0.05 or P <0.01）. CONCLUSION GM has protective effect on BBB in the rats with cerebral I/R. Its mechanism may be related to inhibition of oxidative stress and inflammation, and down-regulation of MMP-2, MMP-9 and NF-κB expression. 相似文献
19.
AIM: To explore the effect of low concentration of N-methyl-N-nitro-N-nitroguanidine (MNNG) on p38MAPK, and the function of glutathione (GSH) on p38MAPK. METHODS: Western blotting was applied to detect the p38MAPK phosphorylation in MNNG treatment group and control group. To study the effect of GSH on MNNG-regulated p38MAPK activity, the intracellular GSH level was reduced by pretreatment of L-buthionine-S, R-sulfoximine (BSO). Assuming the absorbance of band in control group as 1.0, the relative P/T values of the treatment groups were calculated, with the “P” served as absorbance values of phospho-p38MAPK and the “T” as absorbance values of total p38MAPK. RESULTS: In BSO pretreated groups，the relative P/T in samples treated with MNNG for 2.5 h was 0.84, and became 2.19 with 3 h more incubation in the fresh medium. CONCLUSION: GSH deletion increases the activity of p38MAPK in MNNG treatment. 相似文献
20.
AIM: To investigate the effect of hypoxia on the myofibroblast transdifferentiation from fibroblasts,and associated signaling of hypoxia on the production of collagen I in cultured rat renal cortical myofibroblasts.METHODS: The study is composed of two relevant parts.In the first part,a normal rat renal interstitial fibroblast cell line NRK-49F was treated with hypoxia (1% O2) or normoxia (21% O2) for 6 h,12 h and 24 h.The expression of hypoxia inducible factor-1α (HIF-1α) was examined by Western blotting in order to make sure the hypoxic condition is reliable.The myofibroblast transformation from fibroblasts induced by hypoxia was assayed by detecting the protein levels of α-smooth muscle actin (α-SMA).In the second part,the object was done on the primary cultured rat renal cortical myofibroblasts.Myofibroblasts were subjected to hypoxic or normoxic conditions for variety of times.The levels of HIF-1α in cell lysates and collagen I protein in supernatant culture medium and the activation of extracellular signal-regulated kinase (ERK)1/2 MAPK pathway were analyzed by Western blotting.RT-PCR was carried out to measure the levels of collagen I mRNA at different time points (2 h,4 h and 6 h).The distribution of HIF-1α in myofibroblasts was demonstrated by immunocytochemistry.The changes of collagen I production were detected after PD98059,a specific inhibitor of ERK1/2 activation pretreatment and during the hypoxia incubation.The activity of gelatinase matrix metalloproteinase-2(MMP-2) and MMP-9 in the supernatant medium from the cultured cells were assayed by gelatin zymography.RESULTS: Significant increased levels of HIF-1α protein appeared in cell lysates under hypoxia for 6 h.Furthermore,HIF-1α was translocated into nuclei of myofibroblasts after 6 h exposure of myofibroblasts to hypoxia.The levels of α-SMA protein increased in NRK-49F under hypoxia for 12 h (187%±32%,P<0.05).The level of collagen I protein in culture medium was increased in hypoxia treated myofibroblasts at 6 h (171%±27%,P<0.05) and 12 h (256%±61%,P<0.05).Collagen I mRNA expression was increased in cells under hypoxia condition for 4 h (189%±28%,P<0.05) and 6 h (221%±44%,P<0.05).The activities of MMP-2 and MMP-9 in the supernatant medium were not significantly changed at different experimental time points between the normoxic and hypoxic conditions.Activation of ERK1 /2 occurred as early as 15 min,sustained the high level at 30 min and 60 min and was back to the baseline level at 2 h.Blockade of ERK activation with PD98059 abolished hypoxia-induced expressions of collagen I protein.CONCLUSION: Hypoxia contributes to the renal interstitial fibrosis through inducing formation of myofibroblasts and stimulating the production of collagen I in myofibroblasts. 相似文献