Glutamine inhibits over-expression of pro-inflammatory genes and down-regulates the nuclear factor kappaB pathway in an experimental model of colitis in the rat

We investigated the effects of glutamine on markers of oxidative stress, nuclear factor kappaB (NF-kappaB) activation, and pro-inflammatory mediators in a rat model of experimental colitis induced by intracolonic administration of 7% acetic acid. Glutamine (25 mg/kg) was given by rectal route 48 and 24h before acetic acid instillation. Glutamine significantly reduced gross damage and histopathological scores, and partially prevented the decrease of anal pressure observed in the animals receiving acetic acid. Increases in the cytosolic concentration of TBARS and hydroperoxide-initiated chemiluminescence were significantly prevented in glutamine-treated animals. Acetic acid instillation induced a marked increase of the NF-kappaB p65 subunit expression in the nucleus and resulted in significant changes in the cytosolic protein level of IkappaB kinases (IKKalpha and IKKbeta) and the non-phosphorylated form of the inhibitor IkappaBalpha. Protein levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were significantly increased. All these effects were partially prevented by administration of glutamine. It is concluded that the anti-inflammatory activity of glutamine in a rat model of acetic acid-induced colitis may be mediated, at least in part, by inhibition of the expression of certain pro-inflammatory mediators which are regulated by the oxidative stress-sensitive NF-kappaB signalling pathway.     

Role of IKK and ERK pathways in intrinsic inflammation of cystic fibrosis airways

In cystic fibrosis (CF) patients, pulmonary inflammation is a major cause of morbidity and mortality and may precede bacterial colonization. The aim of the present study was to investigate the molecular mechanisms underlying intrinsic inflammation in cystic fibrosis airways. Using different cystic fibrosis cell models, we first demonstrated that, beside a high constitutive nuclear factor of kappaB (NF-kappaB) activity, CF cells showed a higher activator protein-1 (AP-1) activity as compared to their respective control cells. Gene expression profiles, confirmed by RT-PCR and ELISA, showed over-expression of numerous NF-kappaB and AP-1-dependent pro-inflammatory genes in CF cells in comparison with control cells. Activation of NF-kappaB was correlated with higher inhibitor of kappaB kinase (IKK) activity. In addition, Bio-plex phosphoprotein assays revealed higher extracellular signal-regulated kinase (ERK) phosphorylation in CFT-2 cells. Inhibition of this kinase strongly decreased expression of pro-inflammatory genes coding for growth-regulated proteins (Gro-alpha, Gro-beta and Gro-gamma) and interleukins (IL-1beta, IL-6 and IL-8). Moreover, inhibition of secreted interleukin-1beta (IL-1beta) and basic fibroblast growth factor (bFGF) with neutralizing antibodies reduced pro-inflammatory gene expression. Our data thus demonstrated for the first time that the absence of functional cystic fibrosis transmembrane conductance regulator (CFTR) at the plasma membrane leads to an intrinsic AP-1, in addition to NF-kappaB, activity and consequently to a pro-inflammatory state sustained through autocrine factors such as IL-1beta and bFGF.     

低分子肝素对缺血再灌注大鼠肾组织核因子-κB表达的影响

探讨低分子肝素对缺血再灌注大鼠肾组织核因子-κB（NF-κB）表达的影响。建立大鼠IRI模型，健康WistaI大鼠80只随机分为正常对照组、假手术组、模型未治疗组、LMWH治疗组，后两组又分别分为术后1、3、6、24h组。检测各组血清肌酐（Scr）水平及中性粒细胞（PMNs）细胞间黏附分子-1（ICAM-1）表达；通过光镜和免疫组织化学方法观察各组大鼠肾组织形态学及趋化因子NF-κB表达变化。结果表明：（1）肾缺血再灌注未治疗组造模后1h，Scr水平虽然没有明显变化，但ICAM-1、NF-κB表达增多，肾小管坏死积分值亦较假手术组明显增加（P〈0．01）；（2）缺血再灌注6h以后，两组Scr浓度明显增高（P〈0．01），但LMWH治疗组SCr、ICAM-1、NF-κB表达水平及肾小管坏死积分值均明显低于模型未治疗组（P〈0．05）；（3）肾组织中NF-κB表达与肾小管损伤积分值呈现良好的相关性（r=0．71，P〈0、01）；而NF-κB与ICAM-1间则呈现显著正相关（r=0．62，P〈0．05）。由此说明：（1）ICAM-1、NF-κB在肾缺血再灌注早期的瞬时表达，可能参与了炎症早期的白细胞迁移与浸润，与肾损伤的发生密切相关；（2）LMWH可通过减少ICAM-1及NF-κB的表达，阻抑炎症反应过程，减轻肾组织损伤。     

汉防己甲素对白血病耐药细胞株K562/A02核因子κB表达的影响

目的：通过研究汉防己甲素（tetrandrine，Tet）对白血病细胞株K562及其耐药细胞株K562／A02核因子kB（nuclear factor-kaPPaB，NF-kB）表达的影响，探讨Tet逆转多药耐药的作用机制。方法：采用免疫细胞化学及蛋白印迹法分别检测1umol／L Tet作用K562和K562／A02细胞6h和12h舌，细胞NF-kB核转位水平和胞核NF—kB蛋白表达的变化。结果：Tet作用6h和12h后，对K562细胞的NF-kB核转位水平及胞核NF—kB蛋白表达均无明显影响（P〉0．05）；K562／A02细胞NF—kB核转位水平及胞核NF—kB蛋白表达明显高于K562细胞对照组（P〈0．01）；Tet作用6h和12h后，可明显降低K562／A02细胞NF-kB蛋白核转位（P〈0．05）和胞核NF—kB蛋白表达水平（P〈0．01）。作用12h较作用6h效果更显著（P〈0．05）。结论：1umol／L Tet可能通过抑制NF—kB活化逆转K562／A02细胞多药耐药性。     

核因子-κB调控白细胞介素1β刺激人肾小球系膜细胞表达细胞间粘附分子

目的研究核因子κＢ（ＮＦκＢ）对白细胞介素１β（ＩＬ１β）引起的体外培养的人肾小球系膜细胞表达细胞间粘附分子（ＩＣＡＭ１）的基因调控机理。方法采用凝胶迁移率法观测ＮＦκＢ的活化，以Ｎｏｒｔｈｅｒｎ杂交方法检测细胞间粘附分子的基因表达，用细胞ＥＬＩＳＡ法检测ＩＣＡＭ１蛋白水平的表达。结果ｒｈＩＬ１β１０ｎｇ／ｍｌ刺激肾小球系膜细胞１、２、４小时，均引起ＮＦκＢ活化，且１小时为最强。４小时，ＩＣＡＭ１ｍＲＮＡ表达水平上调０３５（刺激前为０１４）。结论细胞因子ＩＬ１β刺激人肾小球系膜细胞表达细胞间粘附分子是通过ＮＦκＢ调控，ＮＦκＢ可能参与调节肾小球疾病的免疫炎症的过程。     

Effect of Nuclear Factor-κB on Airway Remodeling in Asthmatic Rats

Airwayremodeling ,anotherimportantfeatureofasthmaapartfromchronicinflammationintheairwaywall,isasignificantpathologicalbasisofirreversibleairwayobstructionandpersistentairwayhyperrespon siveness.Thestudyonthemechanismofairwayre modelingisofgreatsignifican…     

Caffeic acid phenethyl ester-mediated Nrf2 activation and IκB kinase inhibition are involved in NFκB inhibitory effect: Structural analysis for NFκB inhibition

Caffeic acid phenethyl ester (CAPE) is an active component of propolis from honeybee. We investigated potential molecular mechanisms underlying CAPE-mediated nuclear factor kappa beta (NFκB) inhibition and analyzed structure of CAPE for its biological effect. CAPE attenuated expression of NFκB dependent luciferase stimulated with TNF-α or LPS and suppressed LPS-mediated induction of iNOS, a target gene product of NFκB. In HCT116 cells, CAPE interfered with TNF-α dependent IκBα degradation and subsequent nuclear accumulation of p65, which occurred by direct inhibition of inhibitory protein kappaB kinase (IKK). CAPE increased the expression of Nrf2-dependent luciferase and heme oxygenase-1, a target gene of Nrf2, and elevated the nuclear level of Nrf2 protein, indicating that CAPE activated the Nrf2 pathway. In HCT116 cells with stable expression of Nrf2 shRNA, CAPE elicited a reduced inhibitory effect on TNF-α-activated NFкB compared to scramble RNA expressing control cells. On the other hand, the NFκB inhibitory effect of CAPE was diminished by removal or modification of the Michael reaction acceptor, catechol or phenethyl moiety in CAPE. These data suggest that CAPE inhibits TNF-α-dependent NFκB activation via direct inhibition of IKK as well as activation of Nrf2 pathway, in which the functional groups in CAPE may be involved.     

Assay of DNA-binding proteins with a dsDNA-coupled plate

OBJECTIVES: This paper fabricated a cost-effective dsDNA-coupled plate (dcPlate) and applied it to measure the abundance and DNA-binding activity of a DNA-binding protein (DBP). DESIGN AND METHODS: The dcPlate was manufactured by covalently immobilizing an amino-modified oligonucleotide in wells of the plate coated with N-oxysuccinimide esters. The dcPlate was applied to measure the abundance of DNA-binding activity of a DBP in the same four steps, including protein incubation, primary antibody binding, enzyme-linked secondary antibody binding, and colorimetric development. RESULTS: The detections of three purified DBPs including NF-kappaB, AP1 and SP1, and HeLa cell nuclear extract and assays of DNA-binding activity of NF-kappaB p50 to five various DNA sequences demonstrated that dcPlate can be used to measure the abundance of DBPs quantitatively and assay DNA-binding activity of DBPs in high throughputs format. CONCLUSIONS: The homemade cost-effective dcPlate provides a simple and versatile platform for studying DBPs.     

Missing C‐terminal filaggrin expression,NFkappaB activation and hyperproliferation identify the dog as a putative model to study epidermal dysfunction in atopic dermatitis

Please cite this paper as: Missing C‐terminal filaggrin expression, NFkappaB activation and hyperproliferation identify the dog as a putative model to study epidermal dysfunction in atopic dermatitis. Experimental Dermatology 2010; 19: e343–e346. Abstract: Filaggrin loss‐of‐function mutations resulting in C‐terminal protein truncations are strong predisposing factors in human atopic dermatitis (AD). To assess the possibility of similar truncations in canine AD, an exclusion strategy was designed on 16 control and 18 AD dogs of various breeds. Comparative immunofluorescence microscopy was performed with an antibody raised against the canine filaggrin C‐terminus and a commercial N‐terminal antibody. Concurrent with human AD‐like features such as generalized NFKB activation and hyperproliferation, four distinctive filaggrin expression patterns were indentified in non‐lesional skin. It was found that 10/18 AD dogs exhibited an identical pattern for both antibodies with comparable (category I, 3/18) or reduced (category II, 7/18) expression to that of controls. In contrast, 4/18 dogs displayed aberrant large vesicles revealed by the C‐terminal but not the N‐terminal antibody (category III), while 4/18 showed a control‐like N‐terminal expression but lacked the C‐terminal protein (category IV). The missing C‐terminal filaggrin in category IV strongly points towards loss‐of function mutations in 4/18 (22%) of all AD dogs analysed.     

Does obesity put your brain at risk?

Background and aimsThe negative impact of obesity on the brain is an issue of increasing clinical interest. Hence, this review summarized evidence linking obesity with brain morphology (gray and white matter volume), brain function (functional activation and connectivity), and cognitive function.MethodsA criticals review of the relevant published English articles between 2008 and 2022, using PubMed, Google Scholar and Science Direct. Studies were included if (1) an experimental/intervention study was conducted (2) the experiment/intervention included both high fat diet or body weight, whether it could counteract the negative effect brain morphological or functional change. Critical analysis for a supporting study was also carried out.ResultsBrain dysfunction can be recognized as result from neuroinflammation, oxidative stress, change in gut-brain hormonal functionality decrease regional blood flow or diminished hippocampal size and change in gut-brain hormonal functionality; which collectively translate into a cycle of deranged metabolic control and cognitive deficits, often obesity referred as changes in brain biochemistry and brain function. Recently, a few changes in brain structure and functions could be traced back even to obese children or adult. Evidence here suggested that obesity elicits early neuroinflammation effects, which likely disrupt the normal metabolism in hypothalamus, and hippocampus result from brain insulin resistance. The mechanisms of these robust effects are discussed herein.ConclusionBrain disease is inseparable from obesity itself and requires a better recognition to allow future therapeutic targeting for treatment of obesity. Additional research is needed to identify the best treatment targets and to identify if these changes reversible.