雾化吸入灭活草分枝杆菌降低哮喘小鼠核因子κB及细胞间黏附分子1的表达

 目的:研究雾化吸入灭活草分枝杆菌对支气管哮喘小鼠气道炎症,以及哮喘肺组织中核因子κB(NF-κB)、细胞间黏附分子1(ICAM-1)和血管细胞黏附分子1(VCAM-1)的影响,探讨雾化吸入灭活草分枝杆菌防治哮喘的机制。方法:将24只雄性BALB/c小鼠按随机数字表法分为3组,每组8只：正常对照组（A）、哮喘模型组（B）和治疗组（C）。以鸡卵清蛋白致敏制造小鼠支气管哮喘模型。C组在激发后给予雾化吸入灭活草分枝杆菌治疗5 d,每天1次。各组动物处死后提取肺组织和支气管肺泡灌洗液（BALF）。进行病理HE染色及AB-PAS染色观察气道炎症浸润及黏液分泌情况,并行病理半定量分析。对BALF中炎症细胞进行分类计数。实时荧光定量PCR检测肺组织NF-κB、ICAM-1和VCAM-1的mRNA表达水平。结果:治疗组嗜酸性粒细胞比例低于模型组(P<0.05),气道炎症病变及黏液分泌情况较模型组减轻(P<0.05, P<0.01)。哮喘模型组的肺组织中NF-κB mRNA含量与正常组相比显著升高(P<0.01),而治疗组肺组织中的NF-κB mRNA 含量明显低于模型组(P<0.05);模型组的ICAM-1 mRNA 水平比正常组高(P<0.05),但治疗后明显降低(P<0.01);VCAM-1的 mRNA水平在各组间无显著差异。相关性检验发现小鼠肺组织中VCAM-1的mRNA与ICAM-1的mRNA呈明显正相关(r=0.84,P<0.01),但NF-κB的mRNA与ICAM-1的mRNA、VCAM-1的mRNA无明显相关性(均P>0.05)。结论:雾化吸入草分枝杆菌对支气管哮喘小鼠气道炎症及黏液分泌有抑制作用;NF-κB参与哮喘发病过程,雾化吸入灭活草分枝杆菌降低哮喘小鼠的NF-κB水平。同时雾化吸入灭活草分枝杆菌可降低黏附分子尤其是ICAM-1的表达,是其控制炎症的另一个重要机制。     

微管相关蛋白1B在FMR1基因敲除小鼠睾丸间质细胞中的表达

目的对不同周龄的Fmr1基因敲除和野生型雄性小鼠睾丸组织微管相关蛋白1B的表达进行分析比较,探讨Fmr1基因敲除小鼠的睾丸间质细胞微管相关蛋白1B表达的差异。方法采用不同周龄(4、6、8、10周)的FMR1基因敲除型(KO)和野生型(WT)各6只,先采用聚合酶链式反应(PCR)技术对KO小鼠和WT小鼠进行基因型鉴定,之后所有小鼠麻醉取睾丸组织、石蜡包埋切片进行HE染色对比观察Fmr1小鼠睾丸组织的形态,最后用免疫组织化学染色技术对KO小鼠和WT小鼠睾丸微管相关蛋白1B的表达进行检测并作对比分析。结果微管相关蛋白1B在4～10周小鼠睾丸间质细胞阳性表达,8、10周为强阳性表达,且KO小鼠在睾丸的阳性表达均高于WT小鼠。结论微管相关蛋白1B在同周龄FMR1基因敲除小鼠睾丸间质细胞的表达均显著高于WT小鼠,提示微管相关蛋白1B可能参与脆性X综合征巨睾症的发病过程。     

Ethanol increases nuclear factor-kappa B activity in human astroglial cells

Alcohol abuse adversely affects essentially all the organs of the body, either directly or indirectly. Ethanol may contribute to brain damage via inflammation. Ethanol may also alter CNS immunocompetence and further the progression of certain CNS infections. Nuclear factor (NF)-kappa B helps regulate inflammatory gene expression in glia. It is possible that ethanol effects on CNS pathology are partly a consequence of ethanol modulation of NF-kappa B-associated pathways in glia. We have assessed the effects of 0.5-6 h ethanol exposure on cytokine (5 ng/ml interleukin-1 beta + 100 ng/ml interferon gamma + 30 ng/ml tumor necrosis factor-alpha)-induced NF-kappa B activation in human A172 astroglial cells. Immunoblot analysis indicated that NF-kappa B p65 nuclear translocation occurred within 0.5 h after cytokine stimulation. Stimulation in the presence of ethanol resulted in increased nuclear p65 levels at 3 h, with 200 mM causing a greater increase than 50 mM ethanol. Gel shift assay data suggested that cytokine-induced NF-kappa B binding activity was greatest in cells exposed to 50 mM ethanol, followed by 200 and 0 mM ethanol exposed cells, respectively. Thus, in cytokine-stimulated cells, 200 mM ethanol resulted in greater nuclear p65 levels, yet, 50 mM ethanol exposure resulted in more pronounced DNA binding by NF-kappa B. These findings demonstrate that acute ethanol enhances p65 activity in human astroglia and further support the hypothesis that ethanol-mediated brain pathology involves modulation of NF-kappa B pathways. A better understanding of the mechanistic events involved in ethanol-induced CNS pathology should provide for therapeutic strategies to combat detrimental effects of alcohol on the CNS.     

实验性根尖周炎模型大鼠核因子?B的表达

BACKGROUND:mRNA expression level of nuclear factor-kappa B (NF-?B) in periapical periodontitis has been shown to be significantly higher than that in normal periapical tissue. OBJECTIVE:To observe the expression of NF-?B in rats with periapical periodontitis. METHODS:Twenty male Sprague-Dawley rats aged 6 weeks were enrolled to establish apical periodontitis model at the right mandibular first motar (experimental group), and the left mandibular first motar as normal control group. Five rats were randomly selected at postoperative 1, 2, 3, and 4 weeks to make frozen sections of the mandibular tissue. The morphology of the periapical tissue was observed through hematoxylin-eosin staining, and the expression level and distribution of NF-?B were detected by immunohistochemical staining. RESULTS AND CONCLUSION: (1) Hematoxylin-eosin staining showed that the apical periodontal tissue of the mandibular first molar at the right side had local inflammatory response and spread to peripheral tissues; while there was no pathological changes in the control group. (2) Immunohistochemistry results revealed that NF-?B expression increased from the 1st week to 2nd week after surgery, and then went down at the 3rd week and reached the lowest point at the 4th week; moreover, the expression level at each time exhibited significant differences (P < 0.05). The amount of NF-?B-positive cells in the experimental group was significantly higher than that in the control group (P < 0.05). (3) These findings suggest that the expression level of NF-?B holds close correlation with the process of periapical periodontitis indicating that NF-?B may participate in the inflammatory reaction of periapical periodontitis.  中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程     

Maternal effects in infant and adult phenotypes of 5HT1A and 5HT1B receptor knockout mice

The influence of the pre- and postweaning maternal environment on the offspring's phenotype was examined in 5-HT1A and 5-HT1B receptor knockout mice (KO1A and KO1B, respectively). We have previously shown that, when born to and raised by homozygous dams of the same genotype, adult KO1A are more anxious than wild-type (WT) mice, and adult KO1B are hyperactive and slightly less anxious than WT mice. We extend our studies here to the behavioral results of the offspring's own genotype, when the dam's genotype is constant, and the effects of the dam's genotype when the offspring's genotype is constant. In Experiments 1 and 2, KO1A-/- pups produced less ultrasonic vocalizations (USV) than controls in an isolation test on postnatal Day 7 when born to and reared by KO1A dams, either -/- or +/-. Heterozygous F1 pups reared by KO1A-/- dams produced more USV and were less anxious in the plus-maze at 2 to 3 months of age than F1 pups born to and reared by WT dams (Experiment 3). F1 pups reared by KO1B-/- dams produced less USV and were more anxious in the plus-maze than F1 pups reared by WT dams (Experiment 4). The results support a role for maternal effects that may comprise direct effects such as the dam's behavior and nutritional care of the pup, and possibly more complex indirect effects through the establishment of idiosyncratic dam-pup dyadic interactions. We recommend that breeding techniques that rely on same genotype (mutant-mutant or WT-WT) breeding pairs not be used to generate offspring when the focus of research is the study of gene function, but rather when familial effects need to be studied.     

Subunit-specific effects of isoflurane on neuronal Ih in HCN1 knockout mice

The ionic mechanisms that contribute to general anesthetic actions have not been elucidated, although increasing evidence has pointed to roles for subthreshold ion channels, such as the HCN channels underlying the neuronal hyperpolarization-activated cationic current (Ih). Here, we used conventional HCN1 knockout mice to test directly the contributions of specific HCN subunits to effects of isoflurane, an inhalational anesthetic, on membrane and integrative properties of motor and cortical pyramidal neurons in vitro. Compared with wild-type mice, residual Ih from knockout animals was smaller in amplitude and presented with HCN2-like properties. Inhibition of Ih by isoflurane previously attributed to HCN1 subunit-containing channels (i.e., a hyperpolarizing shift in half-activation voltage [V1/2]) was absent in neurons from HCN1 knockout animals; the remaining inhibition of current amplitude could be attributed to effects on residual HCN2 channels. We also found that isoflurane increased temporal summation of excitatory postsynaptic potentials (EPSPs) in cortical neurons from wild-type mice; this effect was predicted by simulation of anesthetic-induced dendritic Ih inhibition, which also revealed more prominent summation accompanying shifts in V1/2 (an HCN1-like effect) than decreased current amplitude (an HCN2-like effect). Accordingly, anesthetic-induced EPSP summation was not observed in cortical cells from HCN1 knockout mice. In wild-type mice, the enhanced synaptic summation observed with low concentrations of isoflurane contributed to a net increase in cortical neuron excitability. In summary, HCN channel subunits account for distinct anesthetic effects on neuronal membrane properties and synaptic integration; inhibition of HCN1 in cortical neurons may contribute to the synaptically mediated slow-wave cortical synchronization that accompanies anesthetic-induced hypnosis.     

核因子-κB对哮喘患者T淋巴细胞血红素氧合酶-1表达的调控

探讨核因子κB（NF－κB）对哮喘患者T淋巴细胞HO－1表达的转录调节机制。分离18例急性发作期哮喘患者外周血T淋巴细胞，并分成3组培养：对照组、加入NF－κB激动剂肿瘤坏死因子－α（TNF－α）组、同时加入TNF－α和NF－κB抑制剂二硫代氨基甲醇吡咯烷（PDTC）组。培养6h后留取细胞，用逆转录聚合酶链反应（RT－PCR）检测血红素氧合酶－1（HO－1）的mRNA。培养24h后留取细胞用Western印迹法检测HO－1的表达。发现TNF－α组T淋巴细胞HO－1蛋白和mRNA表达水平显著高于对照组（q=44.48、29.94,P均＜0.01)，而同时加入TNF－α和PDTC培养组T淋巴细胞HO－1蛋白和mRNA表达水平显著低于TNF－α组（q=43.23、27.99,P均＜0.01)。可见哮喘患者T淋巴细胞HO－1基因转录可能是通过激活NF－κB进行调控。T淋巴细胞NF－κB－HO氧化激活途径可能是哮喘的发病机制之一。     

Characterization of aging-associated up-regulation of constitutive nuclear factor-kappa B binding activity

Changes occur in gene expression during aging in vivo and in replicative senescence in vitro, suggesting that aging can affect gene regulation. We have recently observed age-related changes in ubiquitously expressed, oxidative stress-responsive nuclear factor-kappa B (NF-kappa B) pathway during aging. Here we report a significant age-related increase in nuclear NF-kappa B binding activity together with increased protein levels of p52 and p65 components in rat liver. An additional, higher molecular weight protein band seen in their western blots suggests that their post-translational modification (but not phosphorylation) occurs in liver, which might affect their nuclear localization and binding activity during aging. However, aging did not affect the protein levels of the main I kappa B inhibitors (I kappa B alpha and I kappa B beta) or I kappa B kinase (IKK)-complex subunits (IKK alpha, -beta, and -gamma) involved in NF-kappa B activation. In addition, the level of Ser32-phosphorylated I kappa B alpha was unaffected by age, suggesting that neither the IKK complex nor altered level of the main inhibitors is involved in the observed up-regulation of NF-kappa B binding activity. Furthermore, the expression of NF-kappa B mRNAs (p50, p52, p65, and c-rel) and the mRNAs of their inhibitors (I kappa B alpha and I kappa B beta) did not show any statistically significant age-related changes. These results indicate that the expression level of NF-kappa B genes is not significantly affected by aging. The up-regulation of constitutive nuclear NF-kappa B binding activity and increased levels of nuclear p52 and p65 proteins might affect the expression of some NF-kappa B target genes in the aging liver.     

Edaravone inhibits collagen-induced arthritis possibly through suppression of nuclear factor-kappa B

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic autoimmune disease which is induced by proinflammatory cytokines or oxidative stress. The activation of nuclear factor-kappa B (NF-kappaB) that contributed to imbalance between apoptosis and proliferation of rheumatoid synovial cells (SC). Edaravone, clinically available free radical scavenger in Japan, is confirmed to be beneficial in the acute stage of stroke. We aimed to investigate the suppressive effect of edaravone on collagen-induced arthritis (CIA) mice and on the activated molecules in SC stimulated by interleukin-1beta (IL-1beta). METHODS: Edaravone was administrated intravenously at a dose of 3mg/kg of body weight to CIA mice. The progression of CIA was evaluated by the macroscopic arthritis scoring system of paws. Interleukin-6 (IL-6) and matrix metalloproteinase-3 (MMP-3) concentrations in culture medium of human SC were measured by enzyme linked immunosorbent assays. Caspase-3/7 activity and nuclear factor-kappa B (NF-kappaB) protein level of cultured human SC were estimated by fluorometric assay and Western blot analysis, respectively. RESULTS: Edaravone significantly decreased macroscopic arthritis score in CIA mice. Acceleration of IL-6 and MMP-3 productions and attenuation of caspase-3/7 activity in IL-1beta-stimulated SC were abated by edaravone. Activated NF-kappaB in IL-1beta-stimulated SC was suppressed by edaravone. CONCLUSION: Edaravone, antioxidants available for clinical use, appears to have therapeutic effect on RA. We suggest that the inhibitory effect of edaravone on RA might be exerted, at least in part, through suppression of activated NF-kappaB. Therefore, we expect therapeutical use of edaravone as an anti-rheumatic agent.     

氯化锂对FMR1基因敲除小鼠的高架十字迷宫行为的干预作用

目的 探讨糖原合成酶激酶3（GSK3）抑制剂氯化锂对FMR1基因敲除（KO）小鼠的高架十字迷宫行为的干预作用及机制。方法 给90只30日龄FMR1基因敲除小鼠连续5d腹腔注射不同剂量的氯化锂,用药第6天进行高架十字迷宫行为学实验,通过录像机录像,然后用Smart软件分析录像,观察能否改善KO鼠的高架十字迷宫的表型;同时通过免疫印迹技术检测KO及野生型（WT）鼠的海马和皮层中GSK3β和磷酸化GSK3β（p-GSK3β）的变化。结果 在高架十字迷宫实验中,与WT组小鼠比较,KO组小鼠的运动性、兴奋性、探索性明显增强,且KO组小鼠在开放区域的活动时间、次数以及路程均明显高于WT组。KO鼠用氯化锂后,在开放区域的活动时间、次数以及路程均减低,差异具有统计学意义（P ＜0.05）。免疫印迹实验结果显示,KO鼠p GSK3β表达比WT鼠少;用氯化锂后,KO鼠p-GSK3β表达增加。WT鼠用氯化锂后,开放区域活动时间、次数以及路程有较少改善,p-GSK3β表达也有增加。未使用氯化锂的KO鼠与WT鼠相比,总GSK3β表达无明显差异,KO鼠和WT鼠使用氯化锂后,总GSK3β无明显改变,P ＞0.05。结论 GSK3β的抑制剂氯化锂能改善KO鼠的高架十字迷宫表型,对KO鼠有治疗作用,其机制可能与氯化锂导致的p-GSK3β表达增加有关。     

香烟烟雾提取物通过活化NF-κB上调小鼠巨噬细胞ICAM-1表达

目的:探讨核因子-κB(NF-κB)对香烟诱导的小鼠巨噬细胞细胞间粘附分子-1(ICAM-1)表达的调控机制,以及地塞米松的抑制作用。方法:分别用香烟烟雾提取物(CSE)、CSE 二硫基氨基甲酸吡咯烷(PDTC)、CSE 地塞米松(DEX)与小鼠巨噬细胞共同孵育1、4和12h,采用免疫细胞化学染色和逆转录聚合酶链式反应(RT-PCR)法检测巨噬细胞NF-κB和ICAM-1的表达。结果:(1)CSE组巨噬细胞NF-κB核染色阳性细胞百分比(41.50%±1.30%)明显高于对照组(10.40%±1.57%),P<0.01;CSE PDTC组和CSE DEX组阳性细胞百分比(17.89%±2.62%,12.72%±1.10%)明显低于CSE组,均P<0.01;(2)CSE组巨噬细胞ICAM-1mRNA水平(1.34±0.05)及其蛋白表达阳性细胞百分比(43.02%±2.37%)明显高于对照组(0.49±0.03,10.58%±0.88%),均P<0.01;CSE PDTC组和CSE DEX组巨噬细胞ICAM-1mRNA水平(0.98±0.05,1.07±0.04)及其蛋白表达阳性细胞百分比(18.42%±1.06%,27.76%±2.06%)明显低于CSE组,均P<0.01;(3)巨噬细胞NF-κB核染色阳性细胞百分比与ICAM-1mRNA水平及其蛋白表达阳性细胞百分比均呈显著正相关(分别为r=0.789和r=0.833,均P<0.01)。结论:香烟可通过诱导巨噬细胞NF-κB的活化在转录水平上上调ICAM-1的表达,地塞米松可抑制香烟诱导的NF-κB活化和ICAM-1的表达。     

Light-induced Fos expression is attenuated in the suprachiasmatic nucleus of serotonin 1B receptor knockout mice

The hypothalamic suprachiasmatic nucleus (SCN) is a circadian oscillator that receives a dense serotonergic innervation from the median raphe nucleus. Serotonin (5-HT) modulates the effects of light on circadian behavior by acting on 5-HT1B receptors on retinohypothalamic (RHT) terminals in the SCN. Activation of 5-HT1B presynaptic receptors on RHT terminals inhibits glutamate release. However, 5-HT1B receptor knockout (5-HT1B KO) mice have attenuated behavioral responses to light [P.J. Sollars, M.D. Ogilvie, A.M. Simpson, G.E. Pickard, Photic entrainment is altered in the 5-HT1B receptor knockout mouse, J. Biol. Rhythms 21 (2006) 21-32]. To assess the cellular response of the 5-HT1B KO SCN to light, light-induced Fos expression was analyzed in 5-HT1B KO and wild-type (WT) mice. In addition, the distribution of melanopsin containing retinal ganglion cells that contribute the majority of axons to the RHT was examined in 5-HT1B KO mice and compared to that of WT mice. Light-induced Fos expression in the SCN was reduced in 5-HT1B KO mice compared to WT mice at circadian time (CT) 16 and CT 23 in a manner similar to the reduction previously described in light-induced behavioral phase shifts. The number of melanopsin retinal ganglion cells was similar in WT and 5-HT1B KO mice. These data taken together with previous data suggest that functional removal of the 5-HT1B receptor results in reduced functional light input to the SCN.     

姜黄素抑制大鼠创伤性骨关节炎模型中软骨细胞核因子κB P65核转位的实验研究

BACKGROUND: Mechanical, inflammatory, and biochemical factors, particularly matrix metalloproteinases and reactive oxygen lead to chondrocyte degeneration in osteoarthritis. Curcumin has been shown to be a potent antioxidant; however, its protective effects against chondrocyte degeneration in osteoarthritis remain unclear. OBJECTIVE: To investigate the potential molecular mechanisms underlying the protective effects of curcumin on articular cartilage of osteoarthritis in rats. METHODS: A total of 30 Sprague-Dawley rats were used and randomly divided into model group (positive control, n=15) and normal group (negative control, n=15). Rat models of traumatic osteoarthritis were established, and then cartilage cells were isolated from articular cartilage and cultured in vitro. Chondrocytes were treated with curcumin (curcumin group) or PDTC (an inhibitor of nuclear factor-kappa B) for 24 hours. The expression level of nuclear factor-kappa B P65 in nucleus and cytoplasm in chondrocytes were determined by western blot assay and immunofluorescence. Moreover, mRNA expressions of type II collagen, matrix metalloproteinase-1 and -13 were analyzed using RT-qPCR. RESULTS AND CONCLUSION: Nuclear factor-kappa B P65 protein was mainly expressed in nucleus, but few in cytoplasm in positive control group; the reversed results were found in the curcumin group. Nuclear translocation of nuclear factor-kappa B P65 was observed mainly in nucleus in the positive control group; however, that was observed mainly in cytoplasm in the negative control, curcumin, and PDTC groups. Matrix metalloproteinase-1 and -13 mRNA expressions were significantly decreased, while type II collagen mRNA expression was significantly increased in the curcumin group compared with the positive control group. These findings indicated that curcumin protect chondrocytes against degeneration through inhibiting the activation of nuclear factor-kappa B signaling pathway, suppressing nuclear translocation of nuclear factor-kappa B P65 and inhibiting the expressions of matrix metalloproteinase-1 and -13, which are responsible for upregulation of type II collagen expression. 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

气道给rhSOD对胎粪诱导肺损伤中NF-κB及MIP-1α表达的影响

目的：观察早期经气道给予重组人超氧化物歧化酶（rhSOD）对胎粪诱导大鼠肺NF-κB和炎症因子MIP-1α表达的影响，以探讨其在胎粪诱导肺损伤中的作用及其机制。 方法： 24只雄性SD大鼠，随机分为：（1）对照组（control）,经气管插管注入生理盐水1 mL/kg；（2）胎粪+生理盐水处理组（Mec/saline）；（3）胎粪+ rhSOD治疗组(Mec/rhSOD)。后两者先由气管插管注入20%新生儿胎粪生理盐水混悬液1 mL/kg建立急性肺损伤模型，再分别经气管插管注入生理盐水1 mL/kg或rhSOD 20 g·L-1·kg-1。24 h后取材， RT-PCR法测定肺组织MIP-1α mRNA、Western blotting法测定NF-κB蛋白表达改变，同时行支气管肺泡灌洗液（BAL）细胞计数。 结果： Mec/saline组大鼠BAL细胞计数、肺组织MIP-1α mRNA和NF-κB蛋白表达均明显高于control组［(4.68±1.40)×109 cells/L vs (0.53±0.19)×109 cells/L, 3.60±0.75 vs 1.56±0.33， 0.72±0.31 vs 0.23±0.21］，（均P<0.01）； Mec/rhSOD组大鼠BAL细胞计数、肺组织MIP-1α mRNA和NF-κB蛋白表达分别为(3.13±0.77)×109cells/L、2.20±0.39和0.44±0.21，均显著低于Mec/saline组（均P<0.01），但仍显著高于control组（均P<0.01）。 结论： 早期经气道给rhSOD可能通过抑制肺MIP-1α和NF-κB表达而减轻胎粪诱导的肺炎症反应。     

Acetaldehyde prevents nuclear factor-kappa B activation and hepatic inflammation in ethanol-fed rats.

Acetaldehyde has been proposed as one of the mediators of liver injury in alcoholic liver disease. We investigated whether increased acetaldehyde levels affected the development of alcoholic liver injury. Male Wistar rats were fed a liquid diet containing fish oil and ethanol by intragastric infusion. Sustained elevations of acetaldehyde were achieved by daily treatment with two inhibitors of aldehyde dehydrogenase (ALDH): disulfiram and benzcoprine. Pathologic changes, plasma and liver acetaldehyde, nuclear factor-kappa B (NF-kappaB) and I kappa B alpha (I kappaB alpha) protein, tumor necrosis factor-alpha (TNF-alpha) and cyclooxygenase 2 (COX-2) mRNA were evaluated. Treatment with the ALDH inhibitors led to increased acetaldehyde in liver and plasma but prevented necrosis and inflammation. Steatosis was not affected. Both inhibitors decreased activation of NF-kappaB and down-regulated TNF-alpha and COX-2 expression. Decreased activation of NF-kappaB was accompanied by I kappaB alpha preservation. Acetaldehyde probably inhibits NF-kappaB activation through I kappaB alpha preservation. Down-regulation of TNF-alpha and COX-2 occur secondary to inhibition of NF-kappaB and account for the absence of necrosis and inflammation in the ALDH inhibitor-treated groups.     

Macrophages are necessary for maximal nuclear factor-kappa B activation in response to endotoxin

To define the role of macrophages in regulating the lung's response to Escherichia coli endotoxin (lipopolysaccharide [LPS]), depletion of macrophages was accomplished by administration of dichloromethylene diphosphonate (clodronate) delivered via intratracheal (i.t.) and/or intravenous (i.v.) routes. Clodronate reduced the number of macrophages in lung lavage 48 h after either i.t. or i.v. administration, but combined i.t. + i.v. clodronate achieved the most profound depletion (90%). Although i.t. clodronate alone had little effect on the evolution of lung inflammation, combined i.t. + i.v. clodronate treatment decreased neutrophilic alveolitis 4 h after exposure to aerosolized LPS by 80% compared with mice treated with empty liposomes. This decrease was associated with impaired activation of nuclear factor (NF)-kappa B and lower concentrations of tumor necrosis factor (TNF)-alpha in lung lavage fluid. Combined i.t. + i.v. clodronate markedly reduced lung NF-kappa B activation and the intensity of neutrophilic alveolitis after intraperitoneal (i.p.) LPS; however, i.v. clodronate alone had no effect on NF-kappa B activation in either liver or lung tissue or the development of neutrophilic alveolitis. We conclude that generalized macrophage depletion reduces NF-kappa B activation, generation of cytokines, and neutrophilic lung inflammation in response to gram negative bacterial endotoxin. These findings define the role of the macrophage as a critical component for initiation of the NF-kappa B-dependent innate immune response.     

Fmr1基因敲除小鼠的ABR阈值观察

目的对不同周龄的KO与WT小鼠听阈进行检测并对比,了解KO小鼠的听阈变化。方法采用PCR法鉴定FMR1基因敲除型(KO)纯合子(-/-)及其野生型(WT)纯合子(+/+)FVB近交系小鼠,实验动物150只分两组:(1)KO组(3、4、6、8、10周龄,每周龄15只,共75只;②WT组(3、4、6、8、10周龄,每周龄15,共75只,用于听性脑干反应(ABR)测试。数据及图像的采集:以ABR图形中Ⅱ波的阈值为小鼠的ABR阈值。结果 ABR阈值:3周及4周年龄组小鼠各基因型间KO小鼠的ABR阈值显著高于WT小鼠,差异有统计学意义(P<0.01);6、8、10周各组中各基因型小鼠的KO小鼠和WT小鼠的ABR阈值的差异无统计学意义(P>0.05)。结论幼年期FMR-1 KO小鼠听阈提高,成熟期FMR-1 KO小鼠听阈无异常,KO小鼠ABR的结果与AGS发生的年龄依赖性相一致。     

Acute Pseudomonas challenge in cystic fibrosis mice causes prolonged nuclear factor-kappa B activation, cytokine secretion, and persistent lung inflammation

BACKGROUND: Cystic fibrosis (CF) is characterized by an excessive and prolonged inflammatory response to Pseudomonas aeruginosa in the lung. There are high levels of cytokines and chemokines and an exaggerated PMN influx causing significant morbidity and mortality. OBJECTIVE: To compare the kinetics of the inflammatory response with the kinetics of clearance of acute bacterial challenge in the lungs of CF and wild-type (WT) mice. METHODS: We challenged CF knockout (KO) and WT mice intratracheally with P aeruginosa in suspension and evaluated bacteria counts, nuclear factor-kappaB (NF-kappaB), and inhibitor of NF-kappaB alpha protein (I-kappaBalpha) in lung tissue, cytokines, and PMN in bronchoalveolar lavage (BAL). RESULTS: Both groups of mice cleared the infection with the same kinetics. CF-KO mice had more PMN in BAL than WT mice. CF-KO mice had high concentrations of proinflammatory cytokines in BAL on days 2 and 4, whereas cytokines in BAL from WT mice were only slightly elevated. CF-KO mice failed to regenerate I-kappaBalpha once it was degraded, and consequently had prolonged and excessive activation of NF-kappaB for the entire 6-day duration of the study. In contrast, WT mice showed only slight NF-kappaB activation, which plateaued at day 4. CONCLUSION: These data suggest that NF-kappaB is dysregulated in CF lung infection and could be a good target for therapy. Prolonged responses to initial acute infections may contribute to the eventual establishment of chronic persistent inflammation. CLINICAL IMPLICATIONS: Dysregulation of the I-kappaB/NF-kappaB pathway in cystic fibrosis leads to prolonged cytokine secretion and persistent inflammation in response to acute challenges and may be important in the development of chronic lung inflammation and infection.