目的:研究细菌脂多糖(LPS)、肿瘤坏死因子(TNF-α)对牛肺动脉内皮细胞(BPAEC)Src抑制的蛋白激酶C底物(Src-suppressed C Kinase Substrate,SSeCKS)表达的影响和对细胞骨架结构的影响,探讨SSeCKS参与细胞骨架结构改变的可能机制。方法:应...目的:研究细菌脂多糖(LPS)、肿瘤坏死因子(TNF-α)对牛肺动脉内皮细胞(BPAEC)Src抑制的蛋白激酶C底物(Src-suppressed C Kinase Substrate,SSeCKS)表达的影响和对细胞骨架结构的影响,探讨SSeCKS参与细胞骨架结构改变的可能机制。方法:应用LPS、TNF-α刺激体外培养的BPAEC,应用原位杂交、免疫印迹方法检测不同刺激条件下BPAEC中SSeCKS mRNA和蛋白的表达情况;免疫细胞荧光法观察LPS、TNF-α对内皮细胞中SSeCKS与纤维状肌动蛋白(F-actin)定位和结构的影响。结果:静息状态的BPAEC表达极少量的SSeCKS;经LPS刺激后,SSeCKS表达没有明显变化;而TNF-α以浓度和时间依赖的方式诱导内皮细胞SSeCKS表达增加;LPS和TNF-α刺激后,F-actin发生重构,且SSeCKS向核周、细胞膜纤维、板状伪足聚集;蛋白激酶C(PKC)抑制剂Ro-31-8220抑制LPS和TNF-α对内皮细胞F-actin和SSeCKS细胞内定位改变的影响。结论:TNF-α能够诱导内皮细胞SSeCKS表达增加,PKC参与LPS、TNF-α诱导内皮细胞F-actin的重构和SSeCKS重新分布,提示SSeCKS可能与LPS和TNF-α诱导内皮细胞F-actin的重构有关。展开更多
目的探讨金盏花苷E对脂多糖(LPS)诱导炎症反应的抑制作用及可能的分子机制。方法 CCK-8实验检测不同浓度(0、2、4、6、8、10、20、25、30μg/mL)的金盏花苷E对RAW264.7细胞活力的影响;不同浓度的金盏花苷E(0、6、8、10μg/mL)预处理RAW2...目的探讨金盏花苷E对脂多糖(LPS)诱导炎症反应的抑制作用及可能的分子机制。方法 CCK-8实验检测不同浓度(0、2、4、6、8、10、20、25、30μg/mL)的金盏花苷E对RAW264.7细胞活力的影响;不同浓度的金盏花苷E(0、6、8、10μg/mL)预处理RAW264.7细胞2 h,然后用LPS(100 ng/mL)刺激细胞特定的时间,ELISA检测炎症因子TNF-α、IL-1β释放;Western blotting检测iNOS、COX-2的表达水平及JAK-stats、MAPKs及NF-кB信号途径的磷酸化;ROS检测试剂盒检测RAW264.7细胞内ROS含量;激光共聚焦实验检测转录因子stat3的核转位。结果 CCK-8结果显示,金盏花苷E浓度在低于20μg/mL时对RAW264.7细胞无明显毒性作用;金盏花苷E浓度依赖性地下调LPS诱导的iNOS和COX-2的表达(P<0.01 vs LPS组);抑制LPS诱导的促炎细胞因子TNF-α及IL-1β的释放,且1 0μg/mL组抑制作用尤为显著(P<0.01 vs LPS组);抑制LPS诱导的JAK1-stat3信号途径激活及stat3的核转位;降低LPS诱发的ROS产生(P<0.01 vs LPS组)。结论金盏花苷E通过抑制ROS介导的JAK1-stat3信号途径,抑制LPS诱导的炎症反应。展开更多
目的:探讨参苓白术散抗脂多糖(lipopolysaccharide,LPS)诱导肠上皮隐窝细胞(intestinal crypt cel ls,IEC-6)通透性变化的机制研究。方法:将IEC-6细胞分为空白组、LPS模型组、LPS+参苓白术散含药血清低、中、高剂量组、10%FBS。对以下...目的:探讨参苓白术散抗脂多糖(lipopolysaccharide,LPS)诱导肠上皮隐窝细胞(intestinal crypt cel ls,IEC-6)通透性变化的机制研究。方法:将IEC-6细胞分为空白组、LPS模型组、LPS+参苓白术散含药血清低、中、高剂量组、10%FBS。对以下指标进行检测:IEC-6细胞凋亡、细胞内钙离子浓度、IEC-6电阻值变化、检测各组中磷酸化Rho激酶(ROCKⅡ)、肌球蛋白轻链激酶(MLCK)以及凋亡因子Caspase-3表达。结果:LPS显著引起IEC-6细胞凋亡而参岺白术散的含药血清明显抑制细胞凋亡。与空白组比较,模型组IEC-6细胞跨膜电阻的TEER值显著下降(P<0.01);与LPS模型组比较,参苓白术散含药血清低、中、高剂量组IEC-6细胞跨膜电阻的TEER值显著升高,实验结果具有统计学意义(P<0.01)。LPS模型组的钙离子浓度明显高于空白组(P<0.01);不同浓度的参苓白术散含药血清组的钙离子浓度明显低于LPS模型组(P<0.01)。与空白组比较,模型组中磷酸化ROCKⅡ、MLCK蛋白表达明显升高(P<0.05);与模型组比较,不同剂量参苓白术散含药血清组中磷酸化ROCKⅡ、MLCK蛋白表达明显降低(P<0.05)。结论:参苓白术散含药血清对LPS诱导的IEC-6细胞损伤具有明显地抑制作用,与抑制细胞凋亡及IEC-6细胞通透性的改善有关。展开更多
To establish a stable and reliable model of refractory hypoxemia acute respiratory distress syndrome （ARDS） and examine its pathological mechanisms, a total of 144 healthy male Wistar rats were randomized into 4 gro...To establish a stable and reliable model of refractory hypoxemia acute respiratory distress syndrome （ARDS） and examine its pathological mechanisms, a total of 144 healthy male Wistar rats were randomized into 4 groups： group Ⅰ （saline control group）, group Ⅱ （LPS intravenous ＂single-hit＂ group）, group Ⅲ （LPS intratracheal ＂single-hit＂ group） and Group IV （LPS ＂two-hit＂ group）. Rats were intravenously injected or intratracheally instilled with a large dose of LPS （10 mg/kg in 0.5 mL） to simulate a single attack of ARDS, or intraperitoneally injected with a small dose of LPS （1 mg/kg） followed by tracheal instillation with median dose of LPS （5 mg/kg） to establish a ＂two-hit＂ model. Rats in each group were monitored by arterial blood gas analysis and visual inspection for three consecutive days. Arterial blood gas values, lung wet/dry weight ratio and pathological pulmonary changes were analyzed to determine the effects of each ALI/ARDS model. Concentrations of TNF-α, IL-1 and IL-10 in the bronchoalveolar lavage fluid （BALF） and blood plasma were meastired by using enzyme-linked immunosorbent assays （ELISA）. Our resulsts showed that single LPS-stimulation, whether through intravenous injection or tracheal instillation, could only induce ALl and temporary hypoxemia in rats. A two-hit LPS stimulation induces prolonged hypoxemia and specific pulmonary injury in rats, and is therefore a more ideal approximation of ARDS in the animal model. The pathogenesis of LPS two-hit-induced ARDS is associated with an uncontrolled systemic inflammatory response and inflammatory injury. It is concluded that the rat ARDS model produced by our LPS two-hit method is more stable and reliable than previous models, and closer to the diagnostic criteria of ARDS, and better mimics the pathological process of ARDS.展开更多
To investigate the effect of the anti-endotoxic part of Radix Isatidis on the expression of moesin mRNA in murine tissues induced by lipopolysaccharide （LPS）, the sample solution of F0z2 part from Radix Isatidis was...To investigate the effect of the anti-endotoxic part of Radix Isatidis on the expression of moesin mRNA in murine tissues induced by lipopolysaccharide （LPS）, the sample solution of F0z2 part from Radix Isatidis was intrapefitoneally administered to experimental mice, and the lipopolysaccharide （LPS） were injected into the tail vein, and then the tissues of liver, kidney and spleen were colleted and cut into slices. The mRNA was detected by moesin mRNA hybridization in situ. The staining results were observed under microscope. It was found that moesin mRNA expression was increased in the tissues of liver, kidndy and spleen in mice treated with LPS, while in the mice pre-treated with F022 part from Radix Isatidis, the LPS-induced moesin mRNA expressions in these tissues were inhibited in a dose-dependant manner. Our study showed that F022 part from Radix Isatidis can inhibit the LPS-induced expression of moesin mRNA in the tissues of liver, kidney and spleen in mice.展开更多
Background:The independent and interactive effects of dietary fiber(DF)and threonine(Thr)were investigated in growing pigs challenged with either systemic E.coli lipopolysaccharide(LPS)or enteric Salmonella Typhimuriu...Background:The independent and interactive effects of dietary fiber(DF)and threonine(Thr)were investigated in growing pigs challenged with either systemic E.coli lipopolysaccharide(LPS)or enteric Salmonella Typhimurium(ST)to characterise their effect on intestinal barrier function.Results:In experiment 1,intestinal barrier function was assessed via oral lactulose and mannitol(L:M)gavage and fecal mucin analysis in pigs challenged with E.coli LPS and fed low fiber(LF)or high fiber(HF)diets with graded dietary Thr.Urinary lactulose recovery and L:M ratio increased(P<0.05)during the LPS inoculation period in LF fed pigs but not in HF fed pigs.Fecal mucin output was increased(P<0.05)in pigs fed HF compared to LF fed pigs.In experiment 2,RT-qPCR,ileal morphology,digesta volatile fatty acid(VFA)content,and fecal mucin output were measured in Salmonella Typhimurium challenged pigs,fed LF or HF diets with standard or supplemented dietary Thr.Salmonella inoculation increased(P<0.05)fecal mucin output compared to the unchallenged period.Supplemental Thr increased fecal mucin output in the HF-fed pigs(Fib×Thr;P<0.05).Feeding HF increased(P<0.05)VFA concentration in cecum and colon.No effect of either Thr or fiber on expression of gene markers was observed except a tendency(P=0.06)for increased MUC2 expression with the HF diet.Feeding HF increased goblet cell numbers(P<0.05).Conclusion:Dietary fiber appears to improve barrier function through increased mucin production capacity(i.e.,goblet cell numbers,MUC2 gene expression)and secretion(i.e.,fecal mucin output).The lack of effect of dietary Thr in Salmonella-challenged pigs provides further evidence that mucin secretion in the gut is conserved and,therefore,Thr may be limiting for growth under conditions of increased mucin production.展开更多
We investigated the effects of lipopolysaccharide （LPS） and dopamine （DA） on the activation of the prophenoloxidase （proPO） system of Litopenaeus vannamei. LPS and DA were shown with a negative dose-dependent ef...We investigated the effects of lipopolysaccharide （LPS） and dopamine （DA） on the activation of the prophenoloxidase （proPO） system of Litopenaeus vannamei. LPS and DA were shown with a negative dose-dependent effect on hyalne cells （HC）, semi-granular cells （SGC）, large granular cells （LGC）, and total haemocyte count （THC）. When haemocytes were treated with LPS or DA, serine proteinase activity and intracellular phenoloxidase （PO） activity were significantly reduced, but extracellular PO activity increased significantly. These findings indicated that the reduction in haemocyte counts was mainly because of the degranulation and activation of the proPO system from semi-granule and large granule cells. The PKC inhibitor, chelerythrine, and the TPK inhibitor, genistein, had an inhibitory effect on extracellular PO activity, while serine proteinase and intracellular PO activity increased. This suggests that the LPS and DA induce the activation of proPO in haemocytes via PKC and TPK-related signaling pathways, but serine proteinase may be activated only by PKC, as the genistein effects were not statistically significant. Electrophoresis analysis revealed that POs induced by LPS or DA have the same molecular mass and high diphenolase activity. Two PO bands at 526 kDa and 272 kDa were observed in PAGE, while in the haemocyte lysate supematant （HLS）, only a 272-kDa band was observed. This band was resolved after SDS-PAGE under non-reducing and reducing conditions into two groups of POs, 166 kDa and 126 kDa, and 78.1 kDa and 73.6 kDa, respectively, suggesting that PO in L. vannamei is an oligomer, which may have different compositions intra- and extracellularly.展开更多
Objective To study the therapeutic effects of Shenyuan Gan(参远苷,SYG)on the inflammat-ory response in BV2 microglial cells induced by lipopolysaccharide(LPS).Methods The cytotoxicity of SYG to BV2 microglial cells wa...Objective To study the therapeutic effects of Shenyuan Gan(参远苷,SYG)on the inflammat-ory response in BV2 microglial cells induced by lipopolysaccharide(LPS).Methods The cytotoxicity of SYG to BV2 microglial cells was evaluated using a Cell Counting Kit-8(CCK-8)assay,and the effect of SYG concentrations on LPS-induced BV2 microglial cells was studied.The morphological changes were observed using an optical microscope.The nitric oxide(NO)concentration in cell culture supernatant was determined using Griess re-agent.The expression of cytokines and inflammatory mediators were also measured by an en-zyme-linked immunosorbent assay(ELISA).Western blot analysis was used to determine the levels of inducible NO synthase(iNOS),nuclear factor-kappa B(NF-κB)p65,alpha inhibitor of NF-κB(IκB-α),phosphorylation-IκB-α(p-IκB-α),NOD-like receptor 3(NLRP3),and cas-pase-1 expression.Moreover,the expression of iNOS,NLRP3,and ionized calcium binding adapter molecule 1(Iba1)was also observed using immunofluorescent staining.Results SYG had a low cytotoxic effect on BV2 microglial cells and could significantly decr-ease LPS-induced morphological changes of BV2 microglial cells(P<0.05).ELISA results showed that SYG significantly inhibited the LPS-induced increase in interleukin(IL)-1βand IL-6 in BV2 microglia cells(P<0.05),and Western blot analysis showed that the phosphoryla-tion levels of iNOS,NF-κB p65,and IκB-αas well as NLRP3 and caspase-1 expression were also significantly decreased,and IκB-αexpression was increased after SYG treatment(P<0.05,compared with the LPS-treated group).The immunofluorescence results were consist-ent with the Western blot results,and Iba1 staining indicated that the cell morphology tended to be resting.These results indicate that SYG has a certain inhibitory effect on LPS-induced inflammation in BV2 microglial cells.Conclusion SYG can inhibit LPS-induced release of inflammatory factors in BV2 microglial cells by affecting the phosphorylation levels of NF-κB p65 and IκB-α.SYG is a valuable candid-ate for treating neuroinflammation-related diseases.展开更多
Lon protease, an ATP-dependent protease in Escherichia coli, degrades abnormal proteins and regulates several important cellular functions. Here we show novel inhibitory effects of lipopolysaccharide (LPS) on Lon prot...Lon protease, an ATP-dependent protease in Escherichia coli, degrades abnormal proteins and regulates several important cellular functions. Here we show novel inhibitory effects of lipopolysaccharide (LPS) on Lon protease activities. LPS inhibited the peptidase, protease, and ATPase activities of Lon;and a dose-response study showed that LPS at low doses more effectively inhibited the ATPase activity than the peptidase one, suggesting different susceptibility to LPS of these activities associated with Lon. Structure-activity relationship studies revealed that ReLPS, detoxified LPS, and mono-phosphoryl as well as diphosphoryl lipid A, also showed similar inhibition, suggesting that neither O-antigen polysaccharide nor O-acyl chain, but rather phosphate groups in the lipid A domain, seem to have been responsible for the inhibitory effects. Besides, LPS was co-precipitated with Lon by an anti-Lon antibody, showing the direct binding of LPS to Lon. These results suggest that LPS bound to Lon and inhibited the protease activity of Lon by inhibiting its ATPase activity. These results also seem to be another example of a negatively charged phosphate group in membrane components of Escherichia coli being involved in the regulation of protease activity of Lon through binding to Lon and inhibiting its ATPase activity, as in the case of cardiolipin.展开更多
文摘目的:研究细菌脂多糖(LPS)、肿瘤坏死因子(TNF-α)对牛肺动脉内皮细胞(BPAEC)Src抑制的蛋白激酶C底物(Src-suppressed C Kinase Substrate,SSeCKS)表达的影响和对细胞骨架结构的影响,探讨SSeCKS参与细胞骨架结构改变的可能机制。方法:应用LPS、TNF-α刺激体外培养的BPAEC,应用原位杂交、免疫印迹方法检测不同刺激条件下BPAEC中SSeCKS mRNA和蛋白的表达情况;免疫细胞荧光法观察LPS、TNF-α对内皮细胞中SSeCKS与纤维状肌动蛋白(F-actin)定位和结构的影响。结果:静息状态的BPAEC表达极少量的SSeCKS;经LPS刺激后,SSeCKS表达没有明显变化;而TNF-α以浓度和时间依赖的方式诱导内皮细胞SSeCKS表达增加;LPS和TNF-α刺激后,F-actin发生重构,且SSeCKS向核周、细胞膜纤维、板状伪足聚集;蛋白激酶C(PKC)抑制剂Ro-31-8220抑制LPS和TNF-α对内皮细胞F-actin和SSeCKS细胞内定位改变的影响。结论:TNF-α能够诱导内皮细胞SSeCKS表达增加,PKC参与LPS、TNF-α诱导内皮细胞F-actin的重构和SSeCKS重新分布,提示SSeCKS可能与LPS和TNF-α诱导内皮细胞F-actin的重构有关。
文摘目的探讨金盏花苷E对脂多糖(LPS)诱导炎症反应的抑制作用及可能的分子机制。方法 CCK-8实验检测不同浓度(0、2、4、6、8、10、20、25、30μg/mL)的金盏花苷E对RAW264.7细胞活力的影响;不同浓度的金盏花苷E(0、6、8、10μg/mL)预处理RAW264.7细胞2 h,然后用LPS(100 ng/mL)刺激细胞特定的时间,ELISA检测炎症因子TNF-α、IL-1β释放;Western blotting检测iNOS、COX-2的表达水平及JAK-stats、MAPKs及NF-кB信号途径的磷酸化;ROS检测试剂盒检测RAW264.7细胞内ROS含量;激光共聚焦实验检测转录因子stat3的核转位。结果 CCK-8结果显示,金盏花苷E浓度在低于20μg/mL时对RAW264.7细胞无明显毒性作用;金盏花苷E浓度依赖性地下调LPS诱导的iNOS和COX-2的表达(P<0.01 vs LPS组);抑制LPS诱导的促炎细胞因子TNF-α及IL-1β的释放,且1 0μg/mL组抑制作用尤为显著(P<0.01 vs LPS组);抑制LPS诱导的JAK1-stat3信号途径激活及stat3的核转位;降低LPS诱发的ROS产生(P<0.01 vs LPS组)。结论金盏花苷E通过抑制ROS介导的JAK1-stat3信号途径,抑制LPS诱导的炎症反应。
文摘目的:探讨参苓白术散抗脂多糖(lipopolysaccharide,LPS)诱导肠上皮隐窝细胞(intestinal crypt cel ls,IEC-6)通透性变化的机制研究。方法:将IEC-6细胞分为空白组、LPS模型组、LPS+参苓白术散含药血清低、中、高剂量组、10%FBS。对以下指标进行检测:IEC-6细胞凋亡、细胞内钙离子浓度、IEC-6电阻值变化、检测各组中磷酸化Rho激酶(ROCKⅡ)、肌球蛋白轻链激酶(MLCK)以及凋亡因子Caspase-3表达。结果:LPS显著引起IEC-6细胞凋亡而参岺白术散的含药血清明显抑制细胞凋亡。与空白组比较,模型组IEC-6细胞跨膜电阻的TEER值显著下降(P<0.01);与LPS模型组比较,参苓白术散含药血清低、中、高剂量组IEC-6细胞跨膜电阻的TEER值显著升高,实验结果具有统计学意义(P<0.01)。LPS模型组的钙离子浓度明显高于空白组(P<0.01);不同浓度的参苓白术散含药血清组的钙离子浓度明显低于LPS模型组(P<0.01)。与空白组比较,模型组中磷酸化ROCKⅡ、MLCK蛋白表达明显升高(P<0.05);与模型组比较,不同剂量参苓白术散含药血清组中磷酸化ROCKⅡ、MLCK蛋白表达明显降低(P<0.05)。结论:参苓白术散含药血清对LPS诱导的IEC-6细胞损伤具有明显地抑制作用,与抑制细胞凋亡及IEC-6细胞通透性的改善有关。
基金supported by a grant from the Shanghai Education Committee(No.2005-81)
文摘To establish a stable and reliable model of refractory hypoxemia acute respiratory distress syndrome （ARDS） and examine its pathological mechanisms, a total of 144 healthy male Wistar rats were randomized into 4 groups： group Ⅰ （saline control group）, group Ⅱ （LPS intravenous ＂single-hit＂ group）, group Ⅲ （LPS intratracheal ＂single-hit＂ group） and Group IV （LPS ＂two-hit＂ group）. Rats were intravenously injected or intratracheally instilled with a large dose of LPS （10 mg/kg in 0.5 mL） to simulate a single attack of ARDS, or intraperitoneally injected with a small dose of LPS （1 mg/kg） followed by tracheal instillation with median dose of LPS （5 mg/kg） to establish a ＂two-hit＂ model. Rats in each group were monitored by arterial blood gas analysis and visual inspection for three consecutive days. Arterial blood gas values, lung wet/dry weight ratio and pathological pulmonary changes were analyzed to determine the effects of each ALI/ARDS model. Concentrations of TNF-α, IL-1 and IL-10 in the bronchoalveolar lavage fluid （BALF） and blood plasma were meastired by using enzyme-linked immunosorbent assays （ELISA）. Our resulsts showed that single LPS-stimulation, whether through intravenous injection or tracheal instillation, could only induce ALl and temporary hypoxemia in rats. A two-hit LPS stimulation induces prolonged hypoxemia and specific pulmonary injury in rats, and is therefore a more ideal approximation of ARDS in the animal model. The pathogenesis of LPS two-hit-induced ARDS is associated with an uncontrolled systemic inflammatory response and inflammatory injury. It is concluded that the rat ARDS model produced by our LPS two-hit method is more stable and reliable than previous models, and closer to the diagnostic criteria of ARDS, and better mimics the pathological process of ARDS.
基金This project was supported by grants from National Natural Sciences Foundation (No. 39870872 and No. 39170877)a grant from the Ministry of Health of China (No. 982110)
文摘To investigate the effect of the anti-endotoxic part of Radix Isatidis on the expression of moesin mRNA in murine tissues induced by lipopolysaccharide （LPS）, the sample solution of F0z2 part from Radix Isatidis was intrapefitoneally administered to experimental mice, and the lipopolysaccharide （LPS） were injected into the tail vein, and then the tissues of liver, kidney and spleen were colleted and cut into slices. The mRNA was detected by moesin mRNA hybridization in situ. The staining results were observed under microscope. It was found that moesin mRNA expression was increased in the tissues of liver, kidndy and spleen in mice treated with LPS, while in the mice pre-treated with F022 part from Radix Isatidis, the LPS-induced moesin mRNA expressions in these tissues were inhibited in a dose-dependant manner. Our study showed that F022 part from Radix Isatidis can inhibit the LPS-induced expression of moesin mRNA in the tissues of liver, kidney and spleen in mice.
基金Funding for this project was provided by Alberta Agriculture and Forestry Strategic Research and Development Section,Evonik Nutrition&Care GmbH,and Mitacs Accelerate.
文摘Background:The independent and interactive effects of dietary fiber(DF)and threonine(Thr)were investigated in growing pigs challenged with either systemic E.coli lipopolysaccharide(LPS)or enteric Salmonella Typhimurium(ST)to characterise their effect on intestinal barrier function.Results:In experiment 1,intestinal barrier function was assessed via oral lactulose and mannitol(L:M)gavage and fecal mucin analysis in pigs challenged with E.coli LPS and fed low fiber(LF)or high fiber(HF)diets with graded dietary Thr.Urinary lactulose recovery and L:M ratio increased(P<0.05)during the LPS inoculation period in LF fed pigs but not in HF fed pigs.Fecal mucin output was increased(P<0.05)in pigs fed HF compared to LF fed pigs.In experiment 2,RT-qPCR,ileal morphology,digesta volatile fatty acid(VFA)content,and fecal mucin output were measured in Salmonella Typhimurium challenged pigs,fed LF or HF diets with standard or supplemented dietary Thr.Salmonella inoculation increased(P<0.05)fecal mucin output compared to the unchallenged period.Supplemental Thr increased fecal mucin output in the HF-fed pigs(Fib×Thr;P<0.05).Feeding HF increased(P<0.05)VFA concentration in cecum and colon.No effect of either Thr or fiber on expression of gene markers was observed except a tendency(P=0.06)for increased MUC2 expression with the HF diet.Feeding HF increased goblet cell numbers(P<0.05).Conclusion:Dietary fiber appears to improve barrier function through increased mucin production capacity(i.e.,goblet cell numbers,MUC2 gene expression)and secretion(i.e.,fecal mucin output).The lack of effect of dietary Thr in Salmonella-challenged pigs provides further evidence that mucin secretion in the gut is conserved and,therefore,Thr may be limiting for growth under conditions of increased mucin production.
基金Supported by the New Century Excellent Talents in University(No.NCET-06-0597)Introducing Talents of Discipline of Universities(111Project)(No.B08049)
文摘We investigated the effects of lipopolysaccharide （LPS） and dopamine （DA） on the activation of the prophenoloxidase （proPO） system of Litopenaeus vannamei. LPS and DA were shown with a negative dose-dependent effect on hyalne cells （HC）, semi-granular cells （SGC）, large granular cells （LGC）, and total haemocyte count （THC）. When haemocytes were treated with LPS or DA, serine proteinase activity and intracellular phenoloxidase （PO） activity were significantly reduced, but extracellular PO activity increased significantly. These findings indicated that the reduction in haemocyte counts was mainly because of the degranulation and activation of the proPO system from semi-granule and large granule cells. The PKC inhibitor, chelerythrine, and the TPK inhibitor, genistein, had an inhibitory effect on extracellular PO activity, while serine proteinase and intracellular PO activity increased. This suggests that the LPS and DA induce the activation of proPO in haemocytes via PKC and TPK-related signaling pathways, but serine proteinase may be activated only by PKC, as the genistein effects were not statistically significant. Electrophoresis analysis revealed that POs induced by LPS or DA have the same molecular mass and high diphenolase activity. Two PO bands at 526 kDa and 272 kDa were observed in PAGE, while in the haemocyte lysate supematant （HLS）, only a 272-kDa band was observed. This band was resolved after SDS-PAGE under non-reducing and reducing conditions into two groups of POs, 166 kDa and 126 kDa, and 78.1 kDa and 73.6 kDa, respectively, suggesting that PO in L. vannamei is an oligomer, which may have different compositions intra- and extracellularly.
基金The Space Medical Experiment Project of the China Manned Space Program(HYZHXM05003)National Natural Science Foundation of China(82171493)+2 种基金Natural Science Foundation of Hunan province(2021JJ30504)Scientific and Technological Innovation Project of the China Academy of Chinese Medical Sciences(CI2021A04905)Scientific Research Fund of Hunan Provincial Education of the Hunan University of Traditional Chinese Medicine First-class Discipline Project of Chinese Medicine(19B422)。
文摘Objective To study the therapeutic effects of Shenyuan Gan(参远苷,SYG)on the inflammat-ory response in BV2 microglial cells induced by lipopolysaccharide(LPS).Methods The cytotoxicity of SYG to BV2 microglial cells was evaluated using a Cell Counting Kit-8(CCK-8)assay,and the effect of SYG concentrations on LPS-induced BV2 microglial cells was studied.The morphological changes were observed using an optical microscope.The nitric oxide(NO)concentration in cell culture supernatant was determined using Griess re-agent.The expression of cytokines and inflammatory mediators were also measured by an en-zyme-linked immunosorbent assay(ELISA).Western blot analysis was used to determine the levels of inducible NO synthase(iNOS),nuclear factor-kappa B(NF-κB)p65,alpha inhibitor of NF-κB(IκB-α),phosphorylation-IκB-α(p-IκB-α),NOD-like receptor 3(NLRP3),and cas-pase-1 expression.Moreover,the expression of iNOS,NLRP3,and ionized calcium binding adapter molecule 1(Iba1)was also observed using immunofluorescent staining.Results SYG had a low cytotoxic effect on BV2 microglial cells and could significantly decr-ease LPS-induced morphological changes of BV2 microglial cells(P<0.05).ELISA results showed that SYG significantly inhibited the LPS-induced increase in interleukin(IL)-1βand IL-6 in BV2 microglia cells(P<0.05),and Western blot analysis showed that the phosphoryla-tion levels of iNOS,NF-κB p65,and IκB-αas well as NLRP3 and caspase-1 expression were also significantly decreased,and IκB-αexpression was increased after SYG treatment(P<0.05,compared with the LPS-treated group).The immunofluorescence results were consist-ent with the Western blot results,and Iba1 staining indicated that the cell morphology tended to be resting.These results indicate that SYG has a certain inhibitory effect on LPS-induced inflammation in BV2 microglial cells.Conclusion SYG can inhibit LPS-induced release of inflammatory factors in BV2 microglial cells by affecting the phosphorylation levels of NF-κB p65 and IκB-α.SYG is a valuable candid-ate for treating neuroinflammation-related diseases.
文摘Lon protease, an ATP-dependent protease in Escherichia coli, degrades abnormal proteins and regulates several important cellular functions. Here we show novel inhibitory effects of lipopolysaccharide (LPS) on Lon protease activities. LPS inhibited the peptidase, protease, and ATPase activities of Lon;and a dose-response study showed that LPS at low doses more effectively inhibited the ATPase activity than the peptidase one, suggesting different susceptibility to LPS of these activities associated with Lon. Structure-activity relationship studies revealed that ReLPS, detoxified LPS, and mono-phosphoryl as well as diphosphoryl lipid A, also showed similar inhibition, suggesting that neither O-antigen polysaccharide nor O-acyl chain, but rather phosphate groups in the lipid A domain, seem to have been responsible for the inhibitory effects. Besides, LPS was co-precipitated with Lon by an anti-Lon antibody, showing the direct binding of LPS to Lon. These results suggest that LPS bound to Lon and inhibited the protease activity of Lon by inhibiting its ATPase activity. These results also seem to be another example of a negatively charged phosphate group in membrane components of Escherichia coli being involved in the regulation of protease activity of Lon through binding to Lon and inhibiting its ATPase activity, as in the case of cardiolipin.
