Enhanced Expression of Aquaporin-9 in Rat Brain Edema Induced by Bacterial Lipopolysaccharides

To investigate the role of AQP9 in brain edema, the expression of AQP9 in an infectious rat brain edema model induced by the injection of lipopolysaccharide （LPS） was examined. Immuno- histochemistry and reverse transcription-polymerase chain reaction （RT-PCR） analysis demonstrated that the expressions of AQP9 mRNA and protein at all observed intervals were significantly increased in LPS-treated animals in comparison with the control animals. Time-course analysis showed that the first signs of blood-brain barrier disruption and the increase of brain water content in LPS-treated animals were evident 6 h after LPS injection, with maximum value appearing at 12 h, which coincided with the expression profiles of AQP9 mRNA and protein in LPS-treated animals. The further correlation analysis revealed strong positive correlations among the brain water content, the disruption of the blood-brain barrier and the enhanced expressions of AQP9 mRNA and protein in LPS-treated animals. These results suggested that the regulation of AQP9 expression may play im- portant roles in water movement and in brain metabolic homeostasis associated with the pathophysi- ology of brain edema induced by LPS injection.

The miR-9-5p/CXCL11 pathway is a key target of hydrogen sulfide-mediated inhibition of neuroinflammation in hypoxic ischemic brain injury

We previously showed that hydrogen sulfide(H2S)has a neuroprotective effect in the context of hypoxic ischemic brain injury in neonatal mice.However,the precise mechanism underlying the role of H2S in this situation remains unclear.In this study,we used a neonatal mouse model of hypoxic ischemic brain injury and a lipopolysaccharide-stimulated BV2 cell model and found that treatment with L-cysteine,a H2S precursor,attenuated the cerebral infarction and cerebral atrophy induced by hypoxia and ischemia and increased the expression of miR-9-5p and cystathionineβsynthase(a major H2S synthetase in the brain)in the prefrontal cortex.We also found that an miR-9-5p inhibitor blocked the expression of cystathionineβsynthase in the prefrontal cortex in mice with brain injury caused by hypoxia and ischemia.Furthermore,miR-9-5p overexpression increased cystathionine-β-synthase and H2S expression in the injured prefrontal cortex of mice with hypoxic ischemic brain injury.L-cysteine decreased the expression of CXCL11,an miR-9-5p target gene,in the prefrontal cortex of the mouse model and in lipopolysaccharide-stimulated BV-2 cells and increased the levels of proinflammatory cytokines BNIP3,FSTL1,SOCS2 and SOCS5,while treatment with an miR-9-5p inhibitor reversed these changes.These findings suggest that H2S can reduce neuroinflammation in a neonatal mouse model of hypoxic ischemic brain injury through regulating the miR-9-5p/CXCL11 axis and restoringβ-synthase expression,thereby playing a role in reducing neuroinflammation in hypoxic ischemic brain injury.

Human umbilical cord-derived mesenchymal stem cells promote repair of neonatal brain injury caused by hypoxia/ischemia in rats

Administration of human umbilical cord-derived mesenchymal stem cells(hUC-MSCs)is believed to be an effective method for treating neurodevelopmental disorde rs.In this study,we investigated the possibility of hUC-MSCs treatment of neonatal hypoxic/ischemic brain injury associated with maternal immune activation and the underlying mechanism.We established neonatal rat models of hypoxic/ischemic brain injury by exposing pregnant rats to lipopolysaccharide on day 16 or 17 of pregnancy.Rat offspring were intranasally administe red hUC-MSCs on postnatal day 14.We found that polypyrimidine tract-binding protein-1(PTBP-1)participated in the regulation of lipopolysaccharide-induced maternal immune activation,which led to neonatal hypoxic/ischemic brain injury.Intranasal delive ry of hUC-MSCs inhibited PTBP-1 expression,alleviated neonatal brain injury-related inflammation,and regulated the number and function of glial fibrillary acidic protein-positive astrocytes,there by promoting plastic regeneration of neurons and im p roving brain function.These findings suggest that hUC-MSCs can effectively promote the repair of neonatal hypoxic/ischemic brain injury related to maternal immune activation through inhibition of PTBP-1 expression and astrocyte activation.

Effect of Dexamethasone on Nitric Oxide Synthase and Caspase-3 Gene Expressions in Endotoxemia in Neonate Rat Brain

Objective To investigate the gene and protein expressions of three isoforms of nitric oxide synthase (NOS) and gene expression of Caspase-3, and effect of dexamethasone on them in neonatal rats with lipopolysaccharide (LPS)-induced endotoxemic brain damage. Methods Expressions of the three isoforms of NOS and caspase-3 mRNA in the brain were investigated by RT-PCR in postnatal 7-day wistar rats with acute endotoxemia by intraperitoneal administration of LPS. Regional distributions of NOSs were examined by immunohistochemical technique. Results nNOS and Caspase-3 mRNA were obviously detected. eNOS mRNA was faintly expressed, but iNOS mRNA was undetectable in the control rat brain. The expressions of NOS mRNA of three isoforms were weak 2 h after LPS (5 mg/mg) delivery, peaked at 6 h, and thereafter, reduced gradually up to 24 h. The expression intensity was in the order of nNOS> iNOS> eNOS. Widespread nNOS, scattered eNOS distribution and negative iNOS were identified in the control rat brain and all isoforms of NOS could be induced by LPS which reached the apex at 24 h in the order of nNOS> iNOS> eNOS as detected by immunostaining. Although Caspase-3 mRNA could be found in all groups, DNA fragmentation was only seen at 6 h and 24 h. The expressions of NOS and Caspase-3 mRNA were inhibited in the rat brain when dexamethasone was administrated. Conclusion LPS-induced NO production induces apoptosis of neurons through mechanism involving the Caspase-3 activation, which may play an important role in the pathogenesis of brain damage during endotoxemia, and neuro-protective effects of dexamethasone may be partially realized by inhibiting the expression of NOS mRNA.

Reducing LncRNA-5657 expression inhibits the brain inflammatory reaction in septic rats

Our preliminary study found that the long noncoding RNA(LncRNA)-5657 can reduce the expression of inflammatory factors during inflammatory reactions in rat glial cells.However, the role played by LncRNA-5657 during septic brain injury remains unclear.In the present study, rat models of septic encephalopathy were established by cecal ligation and puncture, and then the rats were treated with a hippocampal injection small hairpin RNA(sh RNA) against LncRNA-5657(sh-LnCRNA-5657).The sh-LncRNA-5657 treatment reduced the level of neuronal degeneration and necrosis in the rat hippocampus, reduced the immunoreactivities of aquaporin 4, heparanase, and metallopeptidase-9, and lowered the level of tumor necrosis factor-alpha.Glial cells were pre-treated with sh-LncRNA-5657 and then treated with 1 μg/mL lipopolysaccharide.Sh-LncRNA-5657 transfection decreased the expression of LncRNA-5657 in lipopolysaccharide-treated glial cells and decreased the mRNA and protein levels of tumor necrosis factor-alpha, interleukin-1β, and interleukin-6.These findings suggested that LncRNA-5657 expression can significantly reduce the inflammatory reaction during septic encephalopathy and induce protective effects against this disease.This study was approved by the Institutional Ethics Committee at the First Affiliated Hospital of Nanchang University of China(approval No.2017-004) in 2017.

鼠疫耶尔森菌LPS结构变异机制及其免疫逃逸功能研究进展

鼠疫是鼠疫耶尔森菌(以下简称鼠疫菌)引起的一种自然疫源性传染病。鼠疫菌不仅能编码多种毒力因子破坏宿主免疫信号传导,还能修饰其脂多糖的结构,逃逸宿主免疫监视并强烈抑制宿主的免疫响应,是其高致病性形成的重要分子机制之一。鼠疫菌LPS缺乏O抗原,脂质A结构也具有特殊的温度转换调控机制,在不同温度下可形成具有不同数目酰基侧链的脂质A,在其逃逸宿主固有免疫识别和清除中发挥重要作用。本文将对鼠疫菌脂多糖(lipopolysaccharide,LPS)的生物合成调控、结构变异及其免疫逃逸机制的研究进展做一综述,为研究病原菌利用LPS结构修饰逃避宿主固有免疫防御的分子机制提供借鉴。

右美托咪定调控p62/Keap1/Nrf2信号轴对LPS诱导大鼠肝脏损伤的保护机制研究

目的 探究右美托咪定(Dexmedetomidine,Dex)调控自噬受体蛋白p62/Kelch样ECH相关蛋白-1(Kelch-like ECH-associated protein 1,Keap1)/核因子E2相关因子2(Nuclear factor E2 related factor 2,Nrf2)(p62/Keap1/Nrf2)通路对脂多糖(Lipopolysaccharide,LPS)诱导大鼠肝脏损伤的保护作用机制。方法 选取SD大鼠50只,随机将大鼠分为5组,分别为空白对照组(Sham组)、LPS诱导肝脏损伤模型组(LPS组)、LPS诱导+Dex干预组(Dex组)、Keap1/Nrf2信号轴抑制剂组(KI696组)、LPS诱导+Dex干预+KI696组(Dex+KI696组)。统计各组大鼠干预后血清、肝功能因子,包括总胆固醇(Total cholesterol,TC)、总血脂(Total glyceride,TG)、丙氨酸氨基转移酶(Alanine transaminase,ALT)、天门冬氨酸氨基转移酶(Aspartate aminotransferase,AST),肝组织炎症因子白细胞介素-6(Interleukin-6,IL-6)、白细胞介素-8(Interleukin-8,IL-8)、白细胞介素-1β(Interleukin-1β,IL-1β)、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α),氧化应激指标丙二醛(Malondialdehyde,MDA)、超氧化物歧化酶(Superoxide dismutase,SOD)、谷胱甘肽(Glutathione,GSH)、过氧化氢酶(Catalase,CAT)水平差异。HE染色分析各组大鼠肝脏组织病理形态;Western-blot检测各组大鼠肝脏组织p62/Keap1/Nrf2信号轴关键蛋白p62、Keap1、Nrf2,铁死亡关键蛋白前列腺素内过氧化物合酶(Prostaglandin endoperoxide synthase,PTGS2)、谷胱甘肽过氧化物酶4(Glutathione peroxidase 4,GPX4)、铁蛋白基因(Recombinant human ferritin heavy chain,FTH1)表达。结果 与Sham组相比,LPS组p62、TC、TG、ALT、AST、IL-6、IL-8、IL-1β、TNF-α、MDA、PTGS2表达升高,Keap1、Nrf2、SOD、GSH、CAT、GPx4、FTH1表达降低(P<0.05)。与LPS组相比,Dex组p62、TC、TG、ALT、AST、IL-6、IL-8、IL-1β、TNF-α、MDA、PTGS2表达降低,Keap1、Nrf2、SOD、GSH、CAT、GPx4、FTH1表达升高(P<0.05);KI696组Keap1、PTGS2、SOD、GSH、CAT、GPx4、FTH1表达降低,Nrf2、TC、TG、ALT、AST、IL-6、IL-8、IL-1β、TNF-α、MDA表达升高(P<0.05)。与KI696组相比,Dex+KI696组Keap1、PTGS2、SOD、GSH、CAT、GPx4、FTH1表达升高(P<0.05)。结论 右美托咪定通过抑制p62活性,激活Keap1/Nrf2通路活性发挥抗氧化应激损伤、抗炎症反应作用,减缓铁死亡程度,达到保护肝组织的作用。

槲皮素对LPS延迟中性粒细胞自发性凋亡效应的抑制作用

目的 :研究槲皮素对接受细菌脂多糖 (LPS)刺激的中性粒细胞 (PMN)自发性凋亡的影响 ,探讨槲皮素的抗炎作用机制。方法 :以人外周血PMN为研究对象 ,选择光镜和流式细胞术检测细胞凋亡情况 ,对裂解的片段化DNA进行定量 (二苯胺测定法 )和定性 (琼脂糖凝胶电泳 )分析。结果 :槲皮素 (1～ 10 0 μmol/L)对PMN的自发性凋亡率并无影响 ,但却能部分恢复由LPS所延迟的PMN自发性凋亡进程。当槲皮素的浓度为 4 0 μmol/L时 ,其恢复作用达到最大。 结论 :槲皮素对LPS延迟PMN自发性凋亡的效应产生了抑制作用 ,减轻了因预激因子活化PMN而加重的炎症反应 ,部分揭示了槲皮素的抗炎作用机制。

多克隆免疫激发剂LPS免疫激发大鼠引起下丘脑和脑干核团c-fos表达

为了解参与机体免疫调控过程的中枢神经核团，对雄性ＳＤ大鼠侧脑室及腹腔注射多克隆免疫激发剂ＬＰＳ，应用即刻早期表达基因ｃ－ｆｏｓ免疫组织化学法，观察大鼠脑内Ｆｏｓ表达。侧脑室注射ＬＰＳ１０ｎｇ，３ｈ后见下丘脑室旁核内侧部对应ＣＲＦ神经元分布区有密集的Ｆｏｓ阳性染色；外侧及腹侧部相当于ＯＸＴ细胞所在部位的脑干、脊髓投射区有Ｆｏｓ表达细胞；前大细胞亚核亦有Ｆｏｓ染色细胞。视上核、杏仁中央核也观察到较为密集的Ｆｏｓ阳性细胞。腹腔注射ＬＰＳ１００μｇ后０．５ｈ，于侧脑室注射表达Ｆｏｓ的部位见有阳性着色细胞，３ｈ达高峰，随后逐渐降至对照组水平。腹腔注射ＬＰＳ剂量反应曲线显示，５．０μｇ即可引起Ｆｏｓ表达，１００μｇＦｏｓ表达细胞数达高峰。腹腔注射１００μｇ，３ｈ后，下丘脑内Ｆｏｓ表达与侧脑室注射者相似。且在孤束核有密集的Ｆｏｓ表达细胞，经ＴＨ抗体复染，４０％的Ｆｏｓ阳性细胞被双标。结果表明：ＬＰＳ可激活脑内多个神经核团，提示大脑对免疫功能的调控是多部位的协调作用。孤束核参与免疫激发信息的上传；下丘脑室旁核在大脑调控信息下传至免疫器官中起重要作用，其不同亚核分别向垂体前叶、后叶、脑干及脊髓的投射，似可组成３条通路：即下丘?

黄芩白术与PXF对LPS诱导流产小鼠的保胎作用及子宫内IL-10含量的变化研究

Lipopolysaccharide (LPS) was injected via the tail vein (0.1 μg per mouse) to induce abortion (embryo resorption) in Kunming mice. The interleukin 10 (IL-10) contents in the uterus was assayed by ELISA. The results revealed that the IL-10 level was significantly decreased in the LPS-induced abortion group of mice compared with the controls. Use of pentoxifylline, or a combination of Radix scutellariae and Rhizoma atractylodis reversed the LPS effects: bringing down the fetal resorption rate, and enhancing the IL-10 level significantly. The study indicates that the anti-abortive effects of PXF and the combination of Radix scutellariae and Rhizoma atractylodis are closely related to up-regulation of the Th2 cytokine IL-10 at the maternal fetal interface.

益母草碱对LPS诱导小鼠子宫内膜炎的抗炎作用研究

【目的】探究益母草碱对脂多糖(LPS)诱导小鼠子宫内膜炎的抗炎作用。【方法】将60只6~8周龄雌性C57小鼠随机分为6组:空白对照组,模型组,益母草碱低、中、高剂量组及地塞米松阳性对照组,每组10只。空白对照组经阴道灌注50μL PBS缓冲液,其余组经阴道灌注50μL LPS(1 mg/mL)建立小鼠子宫内膜炎疾病模型。造模后,益母草碱低、中、高剂量组分别腹腔注射7.5、15.0、30.0 mg/kg益母草碱,阳性对照组腹腔注射5.0 mg/kg地塞米松,每6 h 1次,连续3次。造模24 h后处死小鼠,测定各组小鼠子宫指数;通过HE染色观察子宫组织病理变化;采用ELISA法检测子宫组织白细胞介素-1β(IL-1β)、IL-6和肿瘤坏死因子-α(TNF-α)等相关炎症因子含量及髓过氧化物酶(MPO)活性。【结果】与空白对照组相比,模型组小鼠子宫指数、子宫组织中炎性细胞因子TNF-α、IL-1β、IL-6含量与MPO活性均极显著升高(P<0.01);与模型组相比,不同剂量益母草碱能不同程度降低LPS诱导子宫内膜炎小鼠的子宫指数、子宫组织中炎性细胞因子TNF-α、IL-1β、IL-6含量与MPO活性(P<0.01),并呈剂量依赖性;与模型组相比,阳性对照组小鼠子宫指数、子宫组织中炎性细胞因子TNF-α、IL-1β、IL-6含量与MPO活性极显著降低(P<0.01)。【结论】益母草碱可降低LPS诱导子宫内膜炎小鼠子宫指数、TNF-α、IL-1β、IL-6炎性因子含量及MPO活性,减轻炎症症状,显示出良好的抗炎效果。

LPS／D-GalN 诱导小鼠急性肝损伤模型的建立

目的建立脂多糖(lipopolysaccharide,LPS)/D-氨基半乳糖(D-galactosamine,D-GalN)诱导小鼠急性肝损伤模型。方法 40只雌性C57BL/6小鼠用于观察8种不同LPS与D-GalN剂量配比联合刺激后小鼠存活时间,以确定模型建立的最佳剂量。使用腹腔注射最佳剂量染毒32只雌性C57BL/6小鼠,分别在0、1、4、8 h处死,每组8只,0 h注射相同剂量生理盐水作为对照。观察染毒后小鼠肝组织病理损伤,检测血清中ALT及炎症因子IL-6、MCP-1和TNF-α表达水平变化。结果通过观察小鼠存活时间,确定腹腔注射最佳染毒剂量为LPS(2.5 mg/kg)/D-GalN(0.3 g/kg);小鼠染毒后肝组织呈进程性病变,最终发展为肝脏弥漫性坏死,肝细胞核崩解。与对照组相比,血清ALT显著升高(P<0.001),IL-6、MCP-1、TNF-α均在1 h后达到最高水平(P<0.001),然后持续下降。结论成功建立LPS/D-GaIN诱导小鼠急性肝损伤模型,为探索急性肝损伤的致病机制以及药物干预治疗提供有效的动物模型。

人Lrp蛋白在细胞中的定位及LPS对其表达的影响

为了对脂多糖应答基因(lrp)的功能进行深入的研究,用镍离子螯合柱(Ni-NTA)纯化后的全长Lrp蛋白免疫新西兰大白兔制备多克隆抗体并吸附去除非特异性反应成分.Western印迹表明,吸附纯化后的抗体可以与Lrp蛋白特异结合,并有较高免疫印迹滴度,为Lrp功能研究提供了重要的工具.激光共聚焦扫描荧光显微镜检测显示Lrp主要位于细胞核膜周围.Western印迹、RT-PCR以及细胞免疫组化染色结果都表明,用LPS刺激后,lrp在人HEK293和U937细胞内的表达均有明显的上升.结果提示,Lrp可能与对Lrp介导的反应有关.

连翘苷对LPS刺激的BV2小胶质细胞炎性反应的抑制作用

目的探索连翘苷对脂多糖（LPS）刺激的小胶质细胞BV-2的细胞炎症因子释放的抑制作用和机制。方法采用LPS（0.1 g/ml）刺激小胶质细胞建立神经退行性疾病（帕金森病）炎症模型,MTT法检测连翘苷对BV2的细胞毒性;硝酸还原酶法检测连翘苷对LPS刺激BV2细胞一氧化氮（NO）表达量的影响;一氧化氮合酶分型法检测连翘苷对LPS刺激BV2细胞一氧化氮合酶（i NOS）活性的影响;Western-blot法检测连翘苷对LPS刺激BV-2细胞TLR4蛋白表达影响。结果 50~200μg/ml连翘苷能抑制LPS诱导BV2细胞的炎症反应。结论连翘苷能够抑制小胶质细胞活化产生的炎症反应,其机制可能是通过抑制TLR4信号通路而发挥效用。

不同浓度葡萄糖透析液及LPS对腹膜透析大鼠腹膜组织VEGF及血管增生的影响及其意义

目的探讨不同浓度葡萄糖透析液及LPS对大鼠腹膜组织血管内皮生长因子(VEGF)表达及血管增生的影响,揭示其影响腹膜转运功能的机制。方法SD大鼠分成A、B、C、D、E五组,A组为正常对照组,其余各组分别每天腹腔注射1.50%、2.50%、4.25%和4.25%腹膜透析液,E组同时注射脂多糖。分别用RT-PCR、免疫荧光检测VEGF的表达及新生血管的数目,同时检测各组超滤量。结果VEGF的表达随着透析液葡萄糖浓度增加而增加,E组表达最强,RT-PCR结果显示:E组VEGF mRNA表达较A升高约11倍[(65±11.35)vs(5.33±2.3);P<0.001];同时CD31免疫组化也显示腹膜新生血管的数目也逐渐增多,E组较A组升高约8倍[(12.2±2.65)vs(1.33±1);P<0.001]。且随着透析液浓度增加其超滤量逐渐减少。结论腹膜组织可表达VEGF。高糖透析液和LPS均能促进腹膜VEGF表达、促进腹膜新生血管的增生,从而增加腹膜转运的有效滤过面积,减少超滤量。这可能是葡萄糖透析液及LPS影响腹膜转运功能的重要机制之一。

植物乳杆菌对LPS诱导的小鼠乳腺炎模型保护作用研究

为了观察植物乳杆菌(LP)对LPS诱导的小鼠乳腺炎模型保护作用,探讨其作用机制,试验采用LPS乳导管灌注方式建立小鼠乳腺炎动物模型,采用ELISA、H.E.染色和Western-blot方法检测灌服植物乳杆菌后小鼠乳腺组织的相关炎症指标。结果表明:植物乳杆菌可以降低LPS诱导的乳腺组织的病理损伤和乳腺组织MPO活性,与LPS组相比,植物乳杆菌治疗组可以显著抑制乳腺组织中NF-κB信号通路的表达。说明饲喂植物乳杆菌对LPS诱导的乳腺炎小鼠具有保护作用。

木香烃内酯通过抑制NLRP3缓解LPS诱导小鼠巨噬细胞的炎症反应

目的:探讨木香烃内酯(Cos)对脂多糖(LPS)诱导的小鼠原代巨噬细胞炎性小体激活和炎症反应的影响。方法:提取并培养小鼠腹腔原代巨噬细胞,用不同浓度Cos预处理巨噬细胞1 h后,1 mg/L LPS处理,分为空白对照组、模型组(单用LPS)、不同浓度(5、10和20μmol/L) Cos+LPS组;ELISA法检测培养液上清中TNF-α/IL-6的含量,q PCR法检测TNF-α/IL-6 mRNA表达;为明确Cos对LPS诱发的炎症反应的保护机制,增加NLRP3抑制剂MCC950组(10μmol/L),LPS刺激4h、6 h,Western blot检测NLRP3、ERK及IκB的激活,细胞免疫荧光实验观察NLRP3的蛋白水平。结果:与LPS组比较,LPS+Cos组TNF-α/IL-6的mRNA表达及细胞培养液上清TNF-α/IL-6分泌均显著降低(P <0. 05);Western blot和细胞免疫荧光实验结果表明,与LPS组比较,LPS+Cos组的NLRP3蛋白水平显著降低,其抑制效果与NLRP3抑制剂MCC950相当(P <0. 05);Western blot结果表明,与LPS组比较,LPS+MCC950组和LPS+Cos组的ERK及IκB的激活均显著降低(P <0. 01)。结论:Cos能有效抑制LPS诱导的巨噬细胞炎性小体和NF-κB的激活而缓解炎症反应。

LPS和TNF-α对血管内皮细胞SSeCKS的表达影响

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。

Ghrelin通过JNK信号通路抑制LPS诱导的肺泡巨噬细胞凋亡

【目的】观察体外条件下加入外源性ghrelin对内毒素(LPS)诱导大鼠肺泡巨噬细胞NR8383凋亡以及吞噬能力的影响,并探讨JNK(c-Jun N-terminal kinase)信号通路在其中所起的作用。【方法】用CCK-8(Cell Counting Kit-8)法检测加入LPS或者ghrelin与LPS共孵育后NR8383的细胞毒性;流式细胞技术、原位末端标记法(TUNEL)检测细胞凋亡率;Western blot检测JNK、phospho-JNK信号通路蛋白以及cleaved caspase-3、Bax、Bcl-2凋亡相关分子蛋白的表达;激光共聚焦技术检测巨噬细胞的吞噬能力;使用ghrelin受体拮抗剂[D-Lys-3]-GHRP-6、JNK特异性抑制剂SP600125分别抑制ghrelin受体及JNK激酶的激活。【结果】CCK-8检测结果显示LPS可显著抑制NR8383增殖,而ghrelin可呈浓度依赖性地阻断这种抑制作用;流式和TUNEL检测进一步证实ghrelin可显著降低LPS所致NR8383凋亡作用(P<0.05),而应用ghrelin受体拮抗剂[D-Lys-3]-GHRP-6可以减弱ghrelin的抗凋亡效果(P<0.05);LPS可以激活JNK激酶活性,并改变其下游凋亡相关蛋白的表达,其中促凋亡蛋白Bax以及cleaved caspase-3表达上调,抗凋亡蛋白Bcl-2表达下调,应用ghrelin可以逆转LPS对JNK激酶的激活,继而下调Bax以及cleaved caspase-3的表达,上调Bcl-2的表达,差异均具有统计学意义(P<0.05);ghrelin还可以维持LPS持续刺激下NR8383的吞噬能力(P<0.05)。【结论】ghrelin通过下调JNK信号通路的激活抑制LPS诱导的NR8383的凋亡,并维持其吞噬能力。

喜炎平注射液对LPS致急性肺损伤大鼠肺泡灌洗液中细胞因子含量的影响

目的:通过观察喜炎平注射液对LPS致急性肺损伤大鼠肺泡灌洗液(BALF)中细胞因子含量的影响,以探讨其治疗急性肺损伤的作用机制。方法:尾静脉注射LPS(2mg/kg)建立大鼠ALI模型,采用ELISA法检测造模后2h、4h、6h后大鼠BALF中TNF-α、IL-1β、IL-8、IL-4、IL-6和IL-10的含量,考察喜炎平注射液的影响。结果:LPS诱发ALI过程中,大鼠BALF中TNF-α、IL-1β、IL-6、IL-8、IL-4、IL-10含量均明显升高,TNF-α、IL-1β、IL-4及IL-10含量在LPS注射2h时均显著高于正常组(P<0.05),IL-6、IL-8含量在LPS注射2h时均显著高于正常组(P<0.05),给予喜炎平注射液后各时间点上述变化均得到一定改善。结论:喜炎平注射液可能通过抑制促炎因子的释放而发挥抗炎作用。