Predominant role of NF-kappa B p65 in the pathogenesis of chronic intestinal inflammation

LRRK2; Communicative Role in the Treatment of Parkinson's Disease and Ulcerative Colitis Overlapping

BACKGROUND

Involvement of gastrointestinal inflammation in Parkinson's disease (PD) pathogenesis and movement have progressively emerged. Inflammation is involved in the etiology of both PD and inflammatory bowel disease (IBD). Transformations in leucine-rich recurrent kinase 2 (LRRK2) are among the best hereditary supporters of IBD and PD. Elevated levels of LRRK2 have been reported in stimulated colonic tissue from IBD patients and peripheral invulnerable cells from irregular PD patients; thus, it is thought that LRRK2 directs inflammatory cycles.

OBJECTIVE

Since its revelation, LRRK2 has been seriously linked in neurons, albeit various lines of proof affirmed that LRRK2 is profoundly communicated in invulnerable cells. Subsequently, LRRK2 might sit at a junction by which stomach inflammation and higher LRRK2 levels in IBD might be a biomarker of expanded risk for inconsistent PD or potentially may address a manageable helpful objective in incendiary sicknesses that increment the risk of PD. Here, we discuss how PD and IBD share covering aggregates, especially regarding LRRK2 and present inhibitors, which could be a helpful objective in ongoing treatments.

METHOD

English data were obtained from Google Scholar, PubMed, Scopus, and Cochrane library studies published between 1990-December 2022.

RESULT

Inhibitors of the LRRK2 pathway can be considered as the novel treatment approaches for IBD and PD treatment.

CONCLUSION

Common mediators and pathways are involved in the pathophysiology of IBD and PD, which are majorly correlated with inflammatory situations. Such diseases could be used for further clinical investigations.

Astragalus polysaccharide (APS) supplement in beagle dogs after castration: Effects on the haematology and serum chemistry profiles, immune response, and oxidative stress status

BACKGROUND

Castration is one of the most common surgical procedures performed in dogs. However, based on increasing evidence, male animals experience significant pain after castration. Astragalus polysaccharide (APS), one of the main bioactive components in A. membranaceus bunge, has been widely used as part of Fu-Zheng therapy to enhance natural defense mechanisms.

INTRODUCTION

This study was carried out to determine the effects of supplementing different doses of Astragalus polysaccharide (APS; control, 0 mg/kg; APSL, 400 mg/kg; and APSH, 800 mg/kg) for 8 weeks on the haematology and serum chemistry profiles, immune response, and oxidative stress status in weanling beagle dogs.

METHODS

After adapting to the experimental environment for 1 week, 18 male beagle dogs (Sichuan Institute of Musk Deer Breeding, China; average initial weight, 3.80 ± 0.43 g; age, 3-month-old) were randomly allotted to diets supplemented with three doses of APS (Control, 0 mg/kg; low, 400 mg/kg; and high, 800 mg/kg), referred to as control, APSL, and APSH, respectively; six dogs were assigned to each treatment. The dogs were fed the respective diets twice daily at 08:30 and 16:30 h in sufficient quantity to supply the metabolizable energy requirements for 8 weeks. On day 43 (19 weeks old), the dogs were castrated. On days 42 (prior to castration, 19 weeks old), 50 (day 7 after castration, 20 weeks old), and 57 (day 14 after castration, 21 weeks old) to measure the haematology, blood chemistry, immune response, and oxidative stress status parameters.

RESULTS

Based on our findings, the APSH diet decreased weight gain and increased the feed to gain ratio in dogs (P < 0.05). At 14 days after castration, the wound was almost closed, slightly swollen, dry, and clean in the groups supplemented with APS. In addition, optimal APS supplementation was found to decrease erythrocyte count (RBC), haematocrit (HCT), alkaline phosphatase (ALP), alanine aminotransferase (ALT), C-reactive protein (CRP), interleukin 1β (IL-1β), and tumor necrosis factor-α (TNF-α) levels, and cortisol and protein carbonyl (PC) concentrations (P < 0.05). Moreover, the mean corpuscular haemoglobin (MCH) and platelet (PLT) levels, interleukin 10 (IL-10) and glutathione (GSH) content, and Cu/Zn superoxide dismutase (SOD1), catalase (CAT), and glutathione peroxidase (Se-GPx) activities were increased in the APS supplemented groups (P < 0.05) CONCLUSION: This study demonstrated that supplementing weanling beagle dogs with optimum APS could positively affect wound healing by improving their haematological profile (decreased RBC and HCT content, increased MCH and PLT levels), serum biochemical parameters (decreased ALP and ALT content), immune status (decreased CRP, IL-1β, and TNF-α levels; increased IL-10 content), and antioxidant defense (decreased cortisol and PC content; increased GSH content, and SOD1, CAT, and Se-GPx activities). However, the detailed mechanism whereby APS regulates these changes requires further investigation. In addition, the results of this study suggest that 400 mg/kg diet is the optimum APS dose for beagle dogs.

Effects of Dietary Phospholipids on Growth Performance, Digestive Enzymes Activity and Intestinal Health of Largemouth Bass (Micropterus salmoides) Larvae

While the beneficial roles of dietary phospholipids on health status and overall performances of fish larvae have been well demonstrated, the underlying mechanisms remain unclear. To address this gap, the present study was conducted to investigate the effects of dietary phospholipids on growth performance, intestinal development, immune response and microbiota of larval largemouth bass (Micropterus salmoides). Five isonitrogenous and isolipidic micro-diets were formulated to contain graded inclusion levels of phospholipids (1.69, 3.11, 5.23, 7.43 and 9.29%). Results showed that the supplementation of dietary phospholipids linearly improved the growth performance of largemouth bass larvae. The inclusion of dietary phospholipids increased the activity of digestive enzymes, such as lipase, trypsin and alkaline phosphatase, and promoted the expression of tight junction proteins including ZO-1, claudin-4 and claudin-5. Additionally, dietary phospholipids inclusion alleviated the accumulation of intestinal triacylglycerols, and further elevated the activity of lysozyme. Dietary phospholipids inhibited the transcription of some pro-inflammatory cytokines, including il-1β, and tnf-α, but promoted the expression of anti-inflammatory cytokines tgf-β, with these modifications being suggested to be mediated by the p38MAPK/Nf-κB pathway. The analysis of bacterial 16S rRNA V3-4 region indicated that the intestinal microbiota profile was significantly altered at the genus level with dietary phospholipids inclusion, including a decreased richness of pathogenic bacteria genera Klebsiella in larval intestine. In summary, it was showed that largemouth bass larvae have a specific requirement for dietary phospholipids, and this study provided novel insights on how dietary phospholipids supplementation contributes to improving the growth performance, digestive tract development and intestinal health.

Potential role of MALT1 as a candidate biomarker of disease surveillance and treatment response prediction in inflammatory bowel disease patients

BACKGROUND

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) regulates adaptive and innate immune responses in several inflammatory disease. However, clinical involvement of MALT1 in inflammatory bowel disease (IBD) patients remains unclear. Hence, this study was intended to investigate the correlation of blood MALT1 with disease activity, inflammation indexes as well as treatment response of IBD patients.

METHODS

Blood MALT1 expression in 100 IBD patients [including 25 active (A)-Crohn's disease (CD) patients, 25 remission (R)-CD patients, 25 A-ulcerative colitis (UC) patients, and 25 R-UC patients] and 25 health controls (HCs) was detected by reverse transcription-quantitative polymerase chain reaction; besides, serum tumor necrosis factor-alpha (TNF-α) and interleukin-17A (IL-17A) in IBD patients were detected by enzyme-linked immunosorbent assay.

RESULTS

MALT1 was increased in A-UC patients than in R-UC patients (p = 0.038) and in HCs (p < 0.001), and also elevated in A-CD patients than in R-CD patients (p = 0.048) and in HCs (p < 0.001). MALT1 was positively related to C-reactive protein (CRP, p = 0.011), TNF-α (p = 0.036), IL-17A (p = 0.023), and Mayo score (p = 0.005) in A-UC patients, CRP (p = 0.017), erythrocyte sedimentation rate (p = 0.033), TNF-α (p = 0.004), and Crohn's disease activity index score (p = 0.028) in A-CD patients. But MALT1 was not correlated with either inflammation indexes or disease activity score in R-UC and R-CD patients. MALT1 gradually declined from baseline to W12 in A-UC and A-CD patients (both p < 0.001). Moreover, MALT1 at W4 (p = 0.031) and W12 (p = 0.003) in A-UC patients as well as MALT1 at W12 (p = 0.008) in A-CD patients associated with clinical response.

CONCLUSION

MALT1 serves as a potential biomarker for disease surveillance and treatment response prediction of IBD patients.

Therapeutic potential of isobavachalcone, a natural flavonoid, in murine experimental colitis by inhibiting NF-κB p65

The incidence of ulcerative colitis (UC), one of the two types of inflammatory bowel disease, is increasing in many countries. Various natural products have been demonstrated with therapeutic potentials for UC. Herein, the therapeutic effects and mechanisms of isobavachalcone (IBC), a natural chalcone, were evaluated in dextran sulfate sodium (DSS)-induced colitis mice and lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The results demonstrated that IBC treatment significantly improved the clinical symptoms, assessed by the disease activity index (DAI) scores and the histological changes of the colon. The levels of myeloperoxidase (MPO), TNF-α, IL-6, IL-1β, and prostaglandin E2 (PGE2) in colon tissues were suppressed by IBC. The upregulation of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and NF-κB p65 in colon tissues were reversed by IBC as well. Furthermore, IBC significantly inhibited LPS-triggered secretion of TNF-α, IL-6, and nitrite, and nuclear translocation of NF-κB p65, in RAW264.7 cells. The luciferase reporter assay indicated that IBC significantly inhibited LPS-triggered transcription of toll-like receptor 4 (TLR4). Molecular docking results showed that the binding pocket of IBC was adjacent to Ser276 of p65-p50 heterodimer and IBC could form H-bond with Thr191. Collectively, these results demonstrated that IBC ameliorated colitis in mice possibly through inhibition of NF-κB p65.

Multipotential and systemic effects of traumatic brain injury

Traumatic brain injury (TBI) is one of the leading causes of disability and mortality of people at all ages. Biochemical, cellular and physiological events that occur during primary injury lead to a delayed and long-term secondary damage that can last from hours to years. Secondary brain injury causes tissue damage in the central nervous system and a subsequent strong and rapid inflammatory response that may lead to persistent inflammation. However, this inflammatory response is not limited to the brain. Inflammatory mediators are transferred from damaged brain tissue to the bloodstream and produce a systemic inflammatory response in peripheral organs, including the cardiovascular, pulmonary, gastrointestinal, renal and endocrine systems. Complications of TBI are associated with its multiple and systemic effects that should be considered in the treatment of TBI patients. Therefore, in this review, an attempt was made to examine the systemic effects of TBI in detail. It is hoped that this review will identify the mechanisms of injury and complications of TBI, and open a window for promising treatment in TBI complications.

Dietary Lysine Levels Improved Antioxidant Capacity and Immunity via the TOR and p38 MAPK Signaling Pathways in Grass Carp, Ctenopharyngodon idellus Fry

An 8-week rearing trial was designed to appraise the dietary lysine levels on intestinal antioxidant capacity and immunity of grass carp fry. Six practical diets were prepared with graded levels of lysine (1.44, 1.79, 1.97, 2.44, 2.56 and 2.87% dry matter), and these diets were fed to grass carp fry. The results showed that the activities of intestinal antioxidant factors including catalase and glutathione peroxidase were markedly improved by the 2.44% dietary lysine compared with the control diet (1.44% dietary lysine) (P < 0.05). In terms of antioxidants, compared with the control diet, the 2.44% diet markedly upregulated the mRNA expression levels of target of rapamycin, S6 kinase1 and nuclear factor erythroid 2-related factor 2 pathway-related antioxidant genes, containing catalase and glutathione peroxidase 1α (P < 0.05) and downregulated the mRNA levels of Kelch-like ECH-associated protein 1 (P > 0.05). The mRNA levels of 4E-binding protein 2 showed the opposite trend compared with those of target of rapamycin, and the minimum value was observed in the group of 1.97% dietary lysine (P < 0.05). In terms of immunity, compared with the 1.44% diet, the 2.44% diet markedly suppressed the intestinal p38 mitogen-activated protein kinase and interferon γ2 mRNA levels (P < 0.05). Moreover, nuclear factor-kappa B p65, tumor necrosis factor α, interleukin 6, interleukin 8, and interleukin 15 mRNA levels all exhibited the same trend as p38 mitogen-activated protein kinase and interferon γ2; however, the difference among all the lysine treatments groups was not significant (P > 0.05). The anti-inflammatory cytokines transforming growth factor β2 and interleukin 4/13B mRNA levels in the intestine were remarkably upregulated by high dietary lysine levels (2.56 and 2.87%) (P < 0.05), and when the dietary lysine level reached 2.44%, the interleukin 4/13A mRNA levels were strikingly increased (P < 0.05). Overall, the data suggested that 2.44% dietary lysine could strengthen the immune and antioxidant capacities of grass carp fry via activating the target of rapamycin (TOR) signaling pathway, and suppressing the p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway, which then improve the survival rate.

Effect of sub-chronic exposure to selenium and astaxanthin on Channa argus: Bioaccumulation, oxidative stress and inflammatory response

Selenium (Se) is the most common micronutrient and that becomes toxic when present at higher concentrations in aquatic environments. Astaxanthin (AST) has been documented to possess antioxidant and anti-inflammatory properties. The aim of this study was to explore the potential of dietary AST and Se exposure on oxidative stress, and inflammatory response in Channa argus. After acclimation, 540 fish were randomly distributed into nine groups housed in twenty-seven glass tanks. The fish were exposed for 8 weeks to waterborne Se at 0, 100 and 200 μg L^-1 or dietary AST at 0, 50 and 100 mg kg^-1. The results shown that Se accumulation in the kidney, liver, spleen, intestine and gill were significantly increased following Se exposure, dietary 50 and 100 mg kg^-1 AST supplementation decreased the accumulation of Se in the kidney, liver, spleen, and intestine. In addition, AST supplementation can decrease oxidative stress and inflammatory response in the liver and spleen following exposure to waterborne Se. These results indicate that AST has the potential to alleviate the effects of Se toxicity in C. argus.

Impairing of gill health through decreasing immune function and structural integrity of grass carp (Ctenopharyngodon idella) fed graded levels dietary lipids after challenged with Flavobacterium columnare

The current study conducted to investigate the hypothesis that low or excess levels of lipids increased the gill rot morbidity through impairing the immune function and structural integrity in the gill of grass carp (Ctenopharyngodon idella). A total of 540 young grass carp with an average initial weight of 261.41 ± 0.53 g were fed diets containing six graded levels of lipids at 0.59%, 2.14%, 3.60%, 5.02%, 6.66% and 8.01% diets for 8 weeks. After the growth trial, fish were challenged with Flavobacterium columnare for 3 days. The results indicated that compared with optimal lipids supplementation (2.14%-8.01% lipids diets), low or excess levels of lipids impaired fish immune function through declining the activities of humoral compounds, down-regulated the mRNA levels of anti-inflammatory cytokines, inhibitor of κBα (IκBα) and ribosomal p70S6 kinase (S6K1), and up-regulated pro-inflammatory cytokines, nuclear factor κB p65 (NF-κB p65) (not p52), IκB kinase α (IKKα) (not IKKβ), IKKγ and eIF4E-binding protein (4EBP) in the gill of young grass carp. In addition, low or excess levels of lipids decreased young grass carp physical barrier function through down-regulating the mRNA levels of ZO-1 (rather than ZO-2b), Claudin b, c, 3, 12, 15a, 15b, 7b, 7a and Occludin through MAPKK 6/p38 MAPK/MLCK signaling molecules, decreasing antioxidant ability via Kelch-like ECH-associating protein 1a (Keap1a)/NF-E2-related factor 2 (Nrf2) signaling molecules, and down-regulating the mRNA levels of B-cell lymphoma-2 (Bcl-2) and inhibitor of apoptosis protein (IAP) and up-regulating the mRNA levels of apoptotic protease activating factor-1 (Apaf-1), Caspase-3, -8 and -9 and Fas ligand (FasL) in the gill of grass carp. Based on the quadratic regression analysis for the gill rot morbidity, C3 and MDA contents, the dietary lipids requirements for young grass carp have been estimated to be 5.60%, 6.01% and 4.58% diets.

Dietary conjugated linoleic acid modulates morphology, selective immune parameters, and gene expressions in the intestine of grass carp

Conjugated linoleic acid (CLA) has been shown to exhibit anti-inflammatory properties in the intestine in mammals. However, the effect of CLA on intestinal immune response in fish is still unknown. Therefore, a 65-day growth trial was conducted to investigate the effects of dietary conjugated linoleic acid (CLA) on morphology, selective immune parameters, and gene expressions in the intestine of grass carp. Seven isonitrogenous and isolipidic diets were formulated as follows: 0 (control), 0.5 (CLA0.5), 1 (CLA1), 1.5 (CLA1.5), 2 (CLA2), 2.5 (CLA2.5), and 3 (CLA3) g CLA per 100g of feed. RESULTS: showed that dietary supplementation of 1.5-3% CLA significantly (P < 0.05) increased the fold and enterocyte heights in the PI and MI of grass carp. Complement 3 (C3) and immunoglobulin M (IgM) contents in three intestinal segments were significantly (P < 0.05) higher in fish fed with CLA1.5 to CLA2.5 diets compared to fish fed the control diet. CLA1.5 to CLA2.5 diets significantly (P < 0.05) increased the mRNA expression levels of anti-inflammatory cytokines (IL-10 and TGFβ1) and significantly (P < 0.05) reduced the mRNA expression levels of pro-inflammatory cytokines (IL-1β, IL-8, and TNF-α) in the PI, MI, and DI. This improved expression of anti-inflammatory cytokines and the inhibited expression of pro-inflammatory cytokines in the intestine of grass carp, might be mediated via TLR4/NF-κB-signaling pathway. Our results suggested that CLA1.5 to CLA2 diets improved intestinal morphology, increased the expression of anti-inflammatory cytokines, and inhibited the expression of pro-inflammatory cytokines in the intestine of grass carp. In conclusion, dietary supplementation of 1.5%-2% CLA show the anti-inflammatory therapeutic potential in the intestine of grass carp. The anti-inflammatory therapeutic potential of CLA might be mediated via TLR4/NF-κB-signaling pathway.

Ameliorating effects of bortezomib, a proteasome inhibitor, on development of dextran sulfate sodium-induced murine colitis

We examined the effect of bortezomib, a proteasome inhibitor, on the development of dextran sulfate sodium (DSS)-induced colitis in mice. DSS-colitis was induced by the administration of 3% DSS in water in C57BL/6J mice. Bortezomib was intraperitoneally administered daily for 9 days from the start of DSS. Ubiquitination of IκBα was evaluated by immunoblot. Bortezomib significantly ameliorated DSS-induced body weight loss and reduced the disease activity. The translocation of NF-κBp65 into the nucleus was markedly suppressed in the DSS + bortezomib group compared to the DSS group, but this difference was not detected in submucosal tissue. Ubiquitinated IκBα in the cytoplasm of colon epithelial cells was increased in the DSS + bortezomib group compared to the DSS group. In HT-29 cells, bortezomib blocked tumor necrosis factor-α (TNF-α)-induced nuclear translocation of NF-κB and this was accompanied by an increase in ubiquitinated IκBα in the cytoplasm. The mRNA expression of inflammatory mediators in colonic epithelial cells was significantly reduced by the treatment of bortezomib. Bortezomib inhibited the nuclear translocation of NF-κB in colonic epithelial cells by suppressing the degradation of IκBα and contributed to an improvement in DSS colitis. Our study suggests that bortezomib may be a new treatment option for IBD.

Pulmonary Administration of Microparticulate Antisense Oligonucleotide (ASO) for the Treatment of Lung Inflammation

Targeted delivery to the lung for controlling lung inflammation is an area that we have explored in this study. The purpose was to use microparticles containing an antisense oligonucleotide (ASO) to NF-κB to inhibit the production of proinflammatory cytokines. Microparticles were prepared using the B-290 Buchi Spray Dryer using albumin as the microparticle matrix. Physicochemical characterization of the microparticles showed the size ranged from 2 to 5 μm, the charge was - 38.4 mV, and they had a sustained release profile over 72 h. Uptake of FITC-labeled ASO-loaded microparticles versus FITC-labeled ASO solution by RAW264.7 murine macrophage cells was 5-10-fold higher. After pulmonary delivery of microparticles to Sprague-Dawley rats, the microparticles were uniformly distributed throughout the lung and were retained in the lungs until 48 h. Serum cytokine (TNF-α and IL-1β) levels of rats after induction of lung inflammation by lipopolysaccharide were measured until 72 h. Animals receiving ASO-loaded microparticles were successful in significantly controlling lung inflammation during this period as compared to animals receiving no treatment. This study was successful in proving that microparticulate ASO therapy was capable of controlling lung inflammation.

ALDH7A1 is a protein that protects Atlantic salmon against Aeromonas salmonicida at the early stages of infection

Aldehyde dehydrogenases (ALDHs) belong to a super-family of detoxifying proteins and perform a significant role in developing epithelial homeostasis, protecting cells from toxic aldehydes and drug resistance. However, the activity and function of these detoxifying proteins remain unknown, especially in fish. In our research, we aimed to study functions of aldehyde dehydrogenase 7A1 (ALDH7A1) in Atlantic salmon infected by Aeromonas salmonicida. Recombinant ALDH7A1 (rALDH7A1) was verified by SDS-PAGE and western blot. The molecular mass of the deduced amino acid sequence of rALDH7A1 is 58.9 kDa with an estimated pI of 7.09. Only a low complexity region (¹⁴¹yvegvgevqeyvdv¹⁵³) without a signal peptide existed in rALDH7A1. Results of ELISA indicated that rALDH7A1 exhibited apparent binding activities with A. salmonicida and its expression was highest in fish kidney. A Real-Time PCR (qRT-PCR) assay in kidneys confirmed that fish in this experiment were authentically infected and bacterial loads in rALDH7A1-adminsitered fish were significantly reduced at an early stage of infection. Meanwhile, we found the mRNA expression of NF-kβ, P-38 MAPK, caspase-3 and TNF-α were mainly up-regulated at 72 h in the kidneys and livers of highly infected fish injected with rALDH7A1, and the same variation trend existed in fish spleens at 12 h. Consistent with these observations, neutralization experiments in vivo indicated that rALDH7A1 could obviously reduce the death rate compared to the BSA and control group. Taken together, we concluded that rALDH7A1 could act in host immune defense against bacterial infection and decrease the mortality rate of Atlantic salmon at early stages of infection with A. salmonicida.

Impairment of gill structural integrity by manganese deficiency or excess related to induction of oxidative damage, apoptosis and dysfunction of the physical barrier as regulated by NF-κB, caspase and Nrf2 signaling in fish

This study is for the first time to explore the possible effects of dietary manganese (Mn) on structural integrity and the related signaling in the gills of fish. Grass carp (Ctenopharyngodon idella) were fed with six diets containing graded levels of Mn [3.65-27.86 mg Mn/kg diet] for 8 weeks. The results firstly demonstrated that Mn deficiency aggravated inflammation indicated by up-regulation of pro-inflammatory cytokines (tumour necrosis factor α, interleukin 8, and interleukin 1β mRNA levels) and down-regulation of anti-inflammatory cytokines (interleukin 10, transforming growth factor-β1) mRNA levels, which might be partially related to the up-regulation of nuclear factor kappa B (NF-κB p65) and down-regulation of nuclear inhibitor factor κBα (iκBα) mRNA levels in the gills of fish. Meanwhile, Mn deficiency caused DNA fragmentation, which might be partially associated with the up-regulation of the apoptosis signaling (caspase-3, caspase-8 and caspase-9) in the gills of fish. Furthermore, Mn deficiency-caused apoptosis might be partly related to the increases of oxidative damage that indicated by increases of lipid peroxidation and protein oxidation, and decreases of antioxidant enzyme activities [included Mn superoxide dismutase (MnSOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST)]. However, Mn deficiency only down-regulated MnSOD and GST mRNA levels, which might be partially related to the up-regulation of NF-E2-related factor-2 (Nrf2) inhibitor (Keap1), and only down-regulated the gene expression of claudin-b and claudin-15 to disrupt the TJ in the gills of fish. Excessive Mn led to negative effects on partial parameters studied in the gills of fish. The optimal levels of Mn based on protecting against ROS, MDA and PC in the gills of grass carp were 17.04, 16.86 and 21.20 mg/kg diet, respectively. Collectively, Mn deficiency or excess could cause inflammation, apoptosis, antioxidant system disruption and change tight junction protein (claudin-b and claudin-15) transcription abundances, which might be partially related to the NF-κB p65, caspase-(3,8,9) and Nrf2 signaling, in the gills of fish.

Cell-penetrating interactomic inhibition of nuclear factor-kappa B in a mouse model of postoperative cognitive dysfunction

Some patients experience impaired cognitive functioning after surgery, a phenomenon referred to as postoperative cognitive dysfunction (POCD). Signs of POCD are closely associated with the development of systemic or hippocampal inflammation. However, the precise pathophysiological mechanisms of prevention/treatment options for POCD still remain unclear. After injury, the transcriptional factor nuclear factor-kappa B (NF-κB) is thought to regulate or stimulate inflammation amplification. Therefore, we designed a cell-penetrating fusion protein called nt-p65-TMD, which inhibits NF-κB p65 activation by translocating into the nucleus. In the present study, we discovered that nt-p65-TMD exerted effects on surgery-induced cognitive impairment in mice. Specifically, nt-p65-TMD exhibited strong immunoregulatory properties that were able to reduce surgery-induced elevations in cerebrovascular integrity impairment, subsequent peripheral immune-cell recruitment, and inflammation amplification, which ultimately lead to cognitive decline. The nt-p65-TMD has the unique ability to regulate and reduce systemic inflammation and inflammation amplification, suggesting a new strategy for preventing development of cognitive decline that occurs in POCD.

Inhibition of corticotropin-releasing hormone receptor 1 and activation of receptor 2 protect against colonic injury and promote epithelium repair

Maternal separation (MS) in neonates can lead to intestinal injury. MS in neonatal mice disrupts mucosal morphology, induces colonic inflammation and increases trans-cellular permeability. Several studies indicate that intestinal epithelial stem cells are capable of initiating gut repair in a variety of injury models but have not been reported in MS. The pathophysiology of MS-induced gut injury and subsequent repair remains unclear, but communication between the brain and gut contribute to MS-induced colonic injury. Corticotropin-releasing hormone (CRH) is one of the mediators involved in the brain–gut axis response to MS-induced damage. We investigated the roles of the CRH receptors, CRHR1 and CRHR2, in MS-induced intestinal injury and subsequent repair. To distinguish their specific roles in mucosal injury, we selectively blocked CRHR1 and CRHR2 with pharmacological antagonists. Our results show that in response to MS, CRHR1 mediates gut injury by promoting intestinal inflammation, increasing gut permeability, altering intestinal morphology, and modulating the intestinal microbiota. In contrast, CRHR2 activates intestinal stem cells and is important for gut repair. Thus, selectively blocking CRHR1 and promoting CRHR2 activity could prevent the development of intestinal injuries and enhance repair in the neonatal period when there is increased risk of intestinal injury such as necrotizing enterocolitis.

Effect of tributyltin on antioxidant ability and immune responses of zebrafish (Danio rerio)

Tributyltin (TBT) is a toxic compound released into aquatic ecosystems through antifouling paints. This study was designed to examine the effects of TBT on antioxidant ability and immune responses of zebrafish (Danio rerio). Three hundred sixty healthy zebrafish were randomly grouped into four groups and exposed to different doses of TBT (0, 1, 10 and 100ngL^-1). At the end of 8 weeks, the fish were sampled, and antioxidant capability, immune parameters and immune-related genes were assessed. The results showed that with an increase in TBT dose, the concentration of malonaldehyde in the liver was significantly increased (p<0.05), whereas the activities of total superoxide dismutase, catalase and glutathione peroxidase were significantly decreased (p<0.05) compared to the control. The activity and expression of lysozyme and the content of immunoglobulin M were significantly decreased compared to those of the fish exposed to 0ngL^-1 TBT (p<0.05). However, the expression of the HSP70, HSP90, tumor necrosis factor-α(TNF-α), interleukins (IL-1β, IL-6), and nuclear factor-kappa B p65 (NF-κ B p65) genes were all enhanced with an increase in TBT dose. The results indicated that TBT induced oxidative stress and had immunotoxic effects on zebrafish.

Protective role of phenylalanine on the ROS-induced oxidative damage, apoptosis and tight junction damage via Nrf2, TOR and NF-κB signalling molecules in the gill of fish

This study explored the possible preventive effects of dietary phenylalanine (Phe) on antioxidant responses, apoptosis and tight junction protein transcription in the gills of young grass carp (Ctenopharyngodon idella). Fish were fed six different experimental diets containing graded levels of Phe (3.4-16.8 g kg^-1) for 8 weeks. The results showed that Phe deficiency induced protein oxidation and lipid peroxidation by decreasing the glutathione content and the activities and mRNA levels of Cu/Zn superoxide dismutase (SOD1), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) in fish gill (P < 0.05). These results may be ascribed to the downregulation of NF-E2-related factor 2 (Nrf2), target of rapamycin (TOR) and ribosomal protein S6 kinase 1 (S6K1), and the upregulation of Kelch-like-ECH-associated protein 1 a (Keap1a) expression in grass carp gills (P < 0.05). Additionally, Phe deficiency induced DNA fragmentation via the up-regulation of Caspase 3, Caspase 8 and Caspase 9 mRNA expression (P < 0.05). These results may be ascribed to the improvement in reactive oxygen species (ROS) levels in the fish gills (P < 0.05). Furthermore, the results indicated that Phe deficiency decreased Claudin b, Claudin 3, Occludin and ZO-1 transcription and increased Claudin 15 expression in the fish gills (P < 0.05). These effects were partly due to the downregulation of interleukin 10 (IL-10), transforming growth factor β (TGF-β) and inhibitor factor κBα (iκBα) and the upregulation of relative mRNA expression of interleukin 1β (IL-1β), interleukin 8 (IL-8), tumour necrosis factor-α (TNF-α) and nuclear transcription factor-κB p65 (NF-κB p65) (P < 0.05). Taken together, the results showed that Phe deficiency impaired the structural integrity of fish gills by regulating the expression of tight junction proteins, cytokines, antioxidant enzymes, NF-κB p65, iκBα, TOR, Nrf2, Keap1 and apoptosis-related genes in the fish gills.

Dietary choline regulates antibacterial activity, inflammatory response and barrier function in the gills of grass carp (Ctenopharyngodon idella)

An 8-week feeding trial was conducted to determine the effects of graded levels of choline (197-1795 mg/kg) on antibacterial properties, inflammatory status and barrier function in the gills of grass carp. The results showed that optimal dietary choline supplementation significantly improved lysozyme and acid phosphatase activities, complement component 3 (C3) content, and the liver expressed antimicrobial peptide 2 and Hepcidin mRNA levels in the gills of fish (P < 0.05). In addition, appropriate dietary choline significantly decreased the oxidative damage, which might be partly due to increase copper, zinc superoxide dismutase (Cu/Zn-SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) activities and increased glutathione content in the gills of fish (P < 0.05). Moreover, appropriate dietary choline significantly up-regulated the mRNA levels of interleukin 10 and transforming growth factor β1, Zonula occludens 1, Occludin, Claudin-b, c, 3 and 12, inhibitor of κBα, target of rapamycin, Cu/Zn-SOD, CAT, GR, GPx, GST and NF-E2-related factor 2 in the gills of fish (P < 0.05). Conversely, appropriate dietary choline significantly down-regulated the mRNA levels of pro-inflammatory cytokines, tumor necrosis factor α, interleukin 8, interferon γ, interleukin 1β, and related signaling factors, nuclear factor kappa B p65, IκB kinase β, IκB kinase γ, myosin light chain kinase and Kelch-like-ECH-associated protein 1a (Keap1a) in the gills of fish (P < 0.05). However, choline did not have a significant effect on the mRNA levels of IκB kinase α, Claudin-15 and Keap1b in the gills of fish. Collectively, appropriate dietary choline levels improved gill antibacterial properties and relative gene expression levels of tight junction proteins, and decreased inflammatory status, as well as up-regulated the mRNA levels of related signaling molecules in the gills of fish. Based on gill C3 content and AHR activity, the dietary choline requirements for young grass carp (266.5-787.1 g) were estimated to be 1191.0 and 1555.0 mg/kg diet, respectively.

The tight junction protein transcript abundance changes and oxidative damage by tryptophan deficiency or excess are related to the modulation of the signalling molecules, NF-κB p65, TOR, caspase-(3,8,9) and Nrf2 mRNA levels, in the gill of young grass carp (Ctenopharyngodon idellus)

This study is for the first time to explore the possible effects of dietary tryptophan (Trp) on structural integrity and the related signalling factor gene expression in the gill of young grass carp (Ctenopharyngodon idella). Fish were fed with six different experimental diets containing graded levels of Trp at 0.7 (control), 1.7, 3.1, 4.0, 5.2 and 6.1 g kg(-1) diet for 8 weeks. The results firstly demonstrated that Trp deficiency or excess caused increases in reactive oxygen species (ROS) contents, and severe oxidative damage (lipid peroxidation and protein oxidation) in the gill of fish, and those negative effects could be reversed by optimal Trp levels. Secondly, compared with the optimal Trp levels, Trp deficiency could cause decreases in the mRNA levels of the barrier functional proteins (occludin, zonula occludens-1, claudin-c, and -3) and increases in the mRNA levels of the pore-formation proteins (claudin-12 and -15) mRNA levels in the gill of fish, and those were reversed by the optimal levels of Trp. The negative effects of Trp deficiency on those tight junction protein gene expression might be partly related to the increases in the mRNA levels of pro-inflammatory cytokines and related signalling factors (tumor necrosis factor α, interleukin 8, interleukin 1β and transcription factor-κB) and decreases in the mRNA levels of anti-inflammatory cytokines and related signalling factors [interleukin 10, transforming growth factor-β1, nuclear inhibitor factor κBα (iκBα), target of rapamyc and ribosome protein S6 kinase 1 (S6K1)] in the gill of fish. In addition, optimal dietary Trp protected the gill of fish against its deficiency-caused increases in the mRNA levels of the apoptosis signalling (caspase-3, caspase-8, caspase-9) and decreases in anti-superoxide radicals capacity, anti-hydroxyl radical capacity, glutathione contents and the activities of Cu/Zn superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) in the gill of fish. Additionally, compared with the Trp deficiency, optimal Trp up-regulated the mRNA levels of SOD, CAT, GPx, GR and GST, which might be partly ascribed to the up-regulation of the NF-E2-related factor 2 (Nrf2) mRNA levels and the down-regulation of Kelch-like-ECH-associated protein 1 (Keap1) mRNA levels in the gill of fish. Interestingly, excessive Trp caused similar results with its deficiency. Collectively, Trp deficiency or excess could cause antioxidant system disruption and change tight junction protein transcription abundances, which were partly related to the signalling factors, NF-κB p65, TOR, caspase-(3,8,9) and Nrf2, in fish gill, those could be blocked by the optimal Trp levels.

Dietary riboflavin deficiency decreases immunity and antioxidant capacity, and changes tight junction proteins and related signaling molecules mRNA expression in the gills of young grass carp (Ctenopharyngodon idella)

This study investigated the effects of dietary riboflavin on the growth, gill immunity, tight junction proteins, antioxidant system and related signaling molecules mRNA expression of young grass carp (Ctenopharyngodon idella). Fish were fed six diets containing graded levels of riboflavin (0.63-10.04 mg/kg diet) for 8 weeks. The study indicated that riboflavin deficiency decreased lysozyme and acid phosphatase activities, and complement component 3 content in the gills of fish (P < 0.05). Moreover, riboflavin deficiency caused oxidative damage, which might be partly due to decrease copper, zinc superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and glutathione-S-transferase activities and reduced glutathione content in the gills of fish (P < 0.05). Furthermore, the relative mRNA levels of antimicrobial peptides (liver expressed antimicrobial peptide 2 and Hepcidin), anti-inflammatory cytokines (interleukin 10 and transforming growth factor β1), tight junction proteins (Occludin, zonula occludens 1, Claudin-c and Claudin-3), signaling molecules (inhibitor of κBα, target of rapamycin and NF-E2-related factor 2) and antioxidant enzymes (copper, zinc superoxide dismutase and glutathione reductase) were significantly decreased (P < 0.05) in the gills of fish fed riboflavin-deficient diet. Conversely, the mRNA levels of pro-inflammatory cytokines (tumor necrosis factor α, interleukin 8, interferon γ2, and interleukin 1β), signaling molecules (nuclear factor kappa B p65, IκB kinase β, IκB kinase γ, Kelch-like-ECH-associated protein 1b and myosin light chain kinase) and tight junction protein Claudin-12 were significantly increased (P < 0.05) in the gills of fish fed riboflavin-deficient diet. In addition, this study indicated for the first time that young fish fed a riboflavin-deficient diet exhibited anorexia and poor growth. In conclusion, riboflavin deficiency decreased growth and gill immunity, impaired gill antioxidant system, as well as regulated mRNA expression of gill tight junction proteins and related signaling molecules of fish. Based on percent weight gain, gill lysozyme activity and reduced glutathione content, the dietary riboflavin requirements for young grass carp (275-722 g) were estimated to be 5.85, 7.39 and 6.34 mg/kg diet, respectively.

Dietary phenylalanine-improved intestinal barrier health in young grass carp (Ctenopharyngodon idella) is associated with increased immune status and regulated gene expression of cytokines, tight junction proteins, antioxidant enzymes and related signalling molecules

The present work evaluated the effects of dietary phenylalanine (Phe) on the intestinal immune response, tight junction proteins transcript abundance, and the gene expression of immune- and antioxidant-related signalling molecules in the intestine. In addition, the dietary Phe (and Phe + Tyr) requirement of young grass carp (Ctenopharyngodon idella) was also estimated. Fish were fed fish meal-casein-gelatin based diets (302.3 g crude protein kg(-1)) containing 3.4 (basal diet), 6.1, 9.1, 11.5, 14.0 and 16.8 g Phe kg(-1) with a fixed amount of 10.7 g tyrosine kg(-1) for 8 weeks. The results showed that Phe deficiency or excess Phe reduced the lysozyme and acid phosphatase activities and complement C 3 content in the intestine (P < 0.05). Moreover, zonula occludens-1 (ZO-1), occludin and claudin c mRNA levels were highest in the fish fed the diet containing 11.5 g Phe kg(-1) (P < 0.05). However, claudin 12 and claudin b mRNA levels were not significantly affected by dietary Phe (P > 0.05). Gene expression of interleukin-10 (IL-10), transforming growth factor-β1 (TGF-β1), target of rapamycin (TOR) and inhibitor of nuclear factor κBα (IκBα) in proximal intestine (PI), mid intestine (MI) and distal intestine (DI) increased as dietary Phe increased up to 6.1, 9.1, 11.5 and 14.0 g kg(-1), respectively (P < 0.05). However, interleukin-8 (IL-8), tumour necrosis factor-α (TNF-α) and nuclear factor-κB p65 (NF-κB p65) mRNA levels showed opposite tendencies. In addition, the mRNA level of superoxide dismutase (SOD) was significantly lower in the intestinal tissue of the group fed a diet with Phe levels of 16.8 g kg(-1) than in those of other groups (P < 0.05). The expression of NF-E2-related factor 2 (Nrf2) gene was increased as dietary Phe increased up to 9.1 g kg(-1) (P < 0.05). In conclusion, Phe improved intestinal immune status, and regulated gene expression of cytokines, tight junction proteins, antioxidant enzymes, NF-κB p65, IκBα, TOR, and Nrf2 in the fish intestine. Based on the quadratic regression analysis of lysozyme activity at a 95% maximum, the dietary Phe requirement of young grass carp (256-629 g) was estimated to be 8.31 g kg(-1), corresponding to 2.75 g 100 g(-1) protein.

Changes in barrier health status of the gill for grass carp (Ctenopharyngodon idella) during valine deficiency: Regulation of tight junction protein transcript, antioxidant status and apoptosis-related gene expression

This study investigated the effects of dietary valine on tight junction protein transcription, antioxidant status and apoptosis on grass carp gills (Ctenopharyngodon idella). Fish were fed six different experimental diets containing graded levels of valine (4.3, 8.0, 10.6, 13.1, 16.7, 19.1 g/kg). The results indicated that valine deficiency decreased Claudin b, Claudin 3, Occludin and ZO-1 transcription and increased Claudin 15 expression in the fish gill (P < 0.05). These effects were partly due to the down-regulation of interleukin 10 (IL-10), transforming growth factor β1 (TGF-β1) and IκB α and the up-regulation of relative mRNA expression of interleukin 1β (IL-1β), interleukin 8 (IL-8), tumor necrosis factor-α (TNF-α) and nuclear factor κB P65 (NF-κB P65) (P < 0.05). However, valine deficiency and valine supplementation did not have a significant effect on Claudin c and Claudin 12 expression in grass carp gills (P > 0.05). Valine deficiency also disrupted antioxidant status in the gill by decreasing anti-superoxide radicals and hydroxyl radical capacity, glutathione contents and the activities and mRNA levels of Cu/Zn superoxide dismutase (SOD1), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-S-transferase (GST) (P < 0.05). These results may be ascribed to the down-regulation of NF-E2-related factor 2 (Nrf2), target of rapamycin (TOR) and ribosomal protein S6 kinase 1 (S6K1) and the up-regulation of Kelch-like-ECH-associated protein 1 (Keap1) (P < 0.05). Additionally, valine deficiency induced DNA fragmentation via the up-regulation of Caspase 3, Caspase 8 and Caspase 9 expressions (P < 0.05). These results may be ascribed to the improvement in ROS levels in the fish gill (P < 0.05). Taken together, the results showed that valine deficiency impaired the structural integrity of fish gill by disrupted fish antioxidant defenses and regulating the expression of tight junction protein, cytokines, antioxidant enzymes, NF-κB p65, IκBα, TOR, Nrf2, Keap1 and apoptosis-related genes in the fish gill.

The impaired intestinal mucosal immune system by valine deficiency for young grass carp (Ctenopharyngodon idella) is associated with decreasing immune status and regulating tight junction proteins transcript abundance in the intestine

This study investigated the effects of dietary valine on the growth, intestinal immune response, tight junction proteins transcript abundance and gene expression of immune-related signaling molecules in the intestine of young grass carp (Ctenopharyngodon idella). Six iso-nitrogenous diets containing graded levels of valine (4.3-19.1 g kg(-)(1) diet) were fed to the fish for 8 weeks. The results showed that percentage weight gain (PWG), feed intake and feed efficiency of fish were the lowest in fish fed the valine-deficient diet (P < 0.05). In addition, valine deficiency decreased lysozyme, acid phosphatase activities and complement 3 content in the intestine (P < 0.05), down-regulated mRNA levels of interleukin 10, transforming growth factor β1, IκBα and target of rapamycin (TOR) (P < 0.05), and up-regulated tumor necrosis factor α, interleukin 8 and nuclear factor κB P65 (NF-κB P65) gene expression (P < 0.05). Additionally, valine deficiency significantly decreased transcript of Occludin, Claudin b, Claudin c, Claudin 3, and ZO-1 (P < 0.05), and improved Claudin 15 expression in the fish intestine (P < 0.05). However, valine did not have a significant effect on expression of Claudin 12 in the intestine of grass carp (P > 0.05). In conclusion, valine deficiency decreased fish growth and intestinal immune status, as well as regulated gene expression of tight junction proteins, NF-κB P65, IκBα and TOR in the fish intestine. Based on the quadratic regression analysis of lysozyme activity or PWG, the dietary valine requirement of young grass carp (268-679 g) were established to be 14.47 g kg(-1) diet (4.82 g 100 g(-1) CP) or 14.00 g kg(-1) diet (4.77 g 100 g(-1) CP), respectively.

OM85-BV induced the productions of IL-1β, IL-6, and TNF-α via TLR4- and TLR2-mediated ERK1/2/NF-κB pathway in RAW264.7 cells

Broncho-Vaxom (OM85-BV) is an extract mixture from 8 strains of Gram(+) and Gram(-) bacteria and plays an important role in anti-infection immune response by regulating macrophage activity and cytokine productions. However, the mechanism by which OM85-BV enhances the cytokine expression is still obscure. In this study, we evaluated the effects of OM85-BV on the productions of interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in RAW264.7 murine macrophages. Exposure of RAW264.7 cells to 100 μg/mL OM85-BV upregulated the expression of IL-1β, IL-6, and TNF-α at the mRNA and protein levels in a time- and dose-dependent manner. In addition, OM85-BV induced extracellular signal-regulated kinase (ERK) 1/2 and nuclear factor-kappa B (NF-κB) phosphorylation. Pretreatment with U0126 or Bay11-7082, respectively, could decrease IL-1β, IL-6, and TNF-α productions induced by OM85-BV. Application of Toll-like receptor (TLR) 4 or TLR2 small-interfering RNA (siRNA) into RAW264.7 cells could inhibit the productions of cytokines and ERK1/2 and NF-κB phosphorylation induced by OM85-BV. Consistent with this, downregulating either myeloid differentiation factor 88 (MyD88) or TRIF-related adaptor molecule (TRAM) gene with MyD88-siRNA or TRAM-siRNA separately could reduce the productions of cytokines and ERK1/2 and NF-κB phosphorylation induced by OM85-BV. Our study demonstrated that the productions of IL-1β, IL-6, and TNF-α induced by OM85-BV in RAW264.7 cells were through TLR4 and TLR2 signaling pathway-mediated activation of ERK1/2 and NF-κB.

Maresin 1, a proresolving lipid mediator derived from omega-3 polyunsaturated fatty acids, exerts protective actions in murine models of colitis

It has been previously reported that dietary fish oils, which are rich in the polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid, can exert beneficial effects in inflammatory bowel disease. In this study, we investigated the effects of docosahexaenoic acid-derived lipid mediator maresin 1 (MaR1) in dextran sulfate sodium (DSS)- and 2,4,6-trinitrobenzenesulfonic acid-induced colitis in mice. Systemic treatment with MaR1 significantly attenuated both DSS- and 2,4,6-trinitrobenzene sulfonic acid-induced colonic inflammation by improving the disease activity index and reducing body weight loss and colonic tissue damage. MaR1 treatment also induced a significant decrease in levels of inflammatory mediators, such as IL-1β, TNF-α, IL-6, and IFN-γ, in the acute protocol, as well as IL-1β and IL-6, but not TNF-α and INF-γ, in the chronic DSS colitis protocol. Additionally, MaR1 decreased ICAM-1 mRNA expression in both the acute and chronic protocols of DSS-induced colitis. Furthermore, the beneficial effects of MaR1 seem to be associated with inhibition of the NF-κB pathway. Moreover, incubation of LPS-stimulated bone marrow-derived macrophage cultures with MaR1 reduced neutrophil migration and reactive oxygen species production, besides decreasing IL-1β, TNF-α, IL-6, and INF-γ production. Interestingly, macrophages incubated only with MaR1 showed a significant upregulation of mannose receptor C, type 1 mRNA expression, an M2 macrophage phenotype marker. These results indicate that MaR1 consistently protects mice against different models of experimental colitis, possibly by inhibiting the NF-κB pathway and consequently multiple inflammatory mediators, as well as by enhancing the macrophage M2 phenotype.

A Picrorhiza kurroa derivative, picroliv, attenuates the development of dextran-sulfate-sodium-induced colitis in mice

Background. Free radicals and proinflammatory cytokines have been shown to play a critical role in the pathogenesis of ulcerative colitis (UC). Picroliv, a Picrorhiza kurroa derivative, has been demonstrated to have antioxidant and anti-inflammatory effect. The purpose of the study was to investigate the effects of picroliv on experimental model of UC in mice. Materials and Methods. Picroliv was administrated orally by gavage to mice with colitis induced by dextran sulfate sodium (DSS). Disease activity index (DAI), colon length, and histology score were observed. Myeloperoxidase (MPO) activity, and SOD, MDA concentrations were measured by enzyme-linked immunosorbent assay (ELISA) while the expression of cytokine mRNAs was studied by real-time-quantitative polymerase chain reaction and also ELISA. The expression of NF-κB p65 was observed by immunohistochemistry staining and western blotting. Results. A significant improvement was observed in DAI and histological score in mice treated with picroliv, and incerased MPO activity, MDA concentrations, and the expression of IL-1β, TNF-α, and NF-κB p65 in mice with DSS-induced colitis were significantly reduced while decreased SOD level increased following administration of picroliv. Conclusion. The administration of picroliv leads to an amelioration of DSS-induced colitis, suggesting administration of picroliv may provide a therapeutic approach for UC.

Inhibitor of PI3Kγ ameliorates TNBS-induced colitis in mice by affecting the functional activity of CD4+CD25+FoxP3+ regulatory T cells

BACKGROUND AND PURPOSE

Phosphoinositide 3-kinase-γ (PI3Kγ) is implicated in many pathophysiological conditions, and recent evidence has suggested its involvement in colitis. In the present study, we investigated the effects of AS605240, a relatively selective PI3Kγ inhibitor, in experimental colitis and its underlying mechanisms.

EXPERIMENTAL APPROACH

Acute colitis was induced in mice by treatment with trinitrobenzene sulphonic acid (TNBS), and the effect of AS605240 on colonic injury was assessed. Pro-inflammatory mediators and cytokines were measured by immunohistochemistry, elisa, real time-polymerase chain reaction and flow cytometry.

KEY RESULTS

Oral administration of AS605240 significantly attenuated TNBS-induced acute colitis and diminished the expression of matrix metalloproteinase-9 and vascular endothelial growth factor. The colonic levels and expression of IL-1β, CXCL-1/KC, MIP-2 and TNF-α were also reduced following therapeutic treatment with AS605240. Moreover, AS605240 reduced MIP-2 levels in a culture of neutrophils stimulated with lipopolysaccharide. The mechanisms underlying these actions of AS605240 are related to nuclear factor-κ (NF-κB) inhibition. Importantly, the PI3Kγ inhibitor also up-regulated IL-10, CD25 and FoxP3 expression. In addition, a significant increase in CD25 and FoxP3 expression was found in isolated lamina propria CD4+ T cells of AS605240-treated mice. The effect of AS605240 on Treg induction was further confirmed by showing that concomitant in vivo blockade of IL-10R significantly attenuated its therapeutic activity.

CONCLUSIONS AND IMPLICATIONS

These results suggest that AS605240 protects mice against TNBS-induced colitis by inhibiting multiple inflammatory components through the NF-κB pathway while simultaneously inducing an increase in the functional activity of CD4+CD25+ Treg. Thus, AS605240 may offer a promising new therapeutic strategy for the treatment of inflammatory bowel diseases.

An anti-inflammatory mechanism of taurine conjugated 5-aminosalicylic acid against experimental colitis: taurine chloramine potentiates inhibitory effect of 5-aminosalicylic acid on IL-1beta-mediated NFkappaB activation

Previously, we reported that oral administration of taurine conjugated 5-aminosalicylic acid, a colon-specific prodrug of 5-aminosalicylic acid (5-ASA), is effective in ameliorating experimental colitis and taurine elicits an additive anti-inflammatory effect upon cotreatment with 5-ASA. To explore a molecular mechanism for the anti-inflammatory property of the prodrug, we investigated the effect of the conjugate on IL-1beta-mediated NFkappaB activation. In human colon carcinoma Caco-2 and HCT116 cells, NFkappaB activity was accessed by a luciferase reporter assay and IL-6 secretion. Protein levels were determined by Western blotting. IL-6 levels were monitored by an Elisa kit. Treatment with either 5-ASA or taurine chloramine (TauCl) inhibited IL-1beta-mediated NFkappaB dependent luciferase expression and IL-6 secretion. In HCT116 cells, the inhibitory effect by TauCl or 5-ASA was through preventing IL-1beta-induced IkappaB kinase activation and subsequently interfering with IkappaBalpha degradation and p65 nuclear accumulation. Furthermore, combined TauCl/5-ASA treatment interfered additively with the activation process, leading to additive inhibitory effect on IL-1beta-mediated NFkappaB activation. Our results suggest that the anti-inflammatory effect of the prodrug on experimental colitis is attributed to the inhibition of the IL-1beta-mediated NFkappaB activation and the taurine effect is through TauCl potentiating the ability of 5-ASA to inhibit IL-1beta dependent NFkappaB activation.

Osteoporosis in inflammatory bowel disease

Osteoporosis commonly afflicts patients with inflammatory bowel disease, and many factors link the 2 states together. A literature review was conducted about the pathophysiology of osteoporosis in relation to inflammatory bowel disease. Screening guidelines for osteoporosis in general as well as those directed at patients with inflammatory bowel disease are reviewed, as are currently available treatment options. The purpose of this article is to increase physician awareness about osteopenia and osteoporosis occurring in patients with inflammatory bowel disease and to provide basic, clinically relevant information about the pathophysiology and guidelines to help them treat these patients in a cost-effective manner.

Therapeutic action and underlying mechanisms of a combination of two pentacyclic triterpenes, alpha- and beta-amyrin, in a mouse model of colitis

BACKGROUND AND PURPOSE

alpha- and beta-amyrin are pentacyclic triterpenes found in plants and are known to exhibit pronounced anti-inflammatory effects. Here, we evaluated the effects of a 1:1 mixture of alpha- and beta-amyrin (alpha,beta-amyrin) on an experimental model of colitis in mice.

EXPERIMENTAL APPROACH

Colitis was induced in Swiss male mice by trinitrobenzene sulphonic acid (TNBS) and followed up to 72 h; animals were treated systemically with alpha,beta-amyrin, dexamethasone or vehicle. Macro- and microscopic damage, myeloperoxidase activity and cytokine levels were assessed in colons. Histological sections were immunostained for cyclooxygenase-2 (COX-2), vascular endothelial growth factor, phospho-p65 nuclear factor-kappaB (NF-kappaB) and phospho-cyclic AMP response element-binding protein (CREB).

KEY RESULTS

TNBS-induced colitis was associated with tissue damage, neutrophil infiltration and time-dependent increase of inflammatory mediators. Treatment with alpha,beta-amyrin (3 mg x kg(-1), i.p.) or dexamethasone (1 mg x kg(-1), s.c.) consistently improved tissue damage scores and abolished polymorphonuclear cell infiltration. alpha,beta-Amyrin, like dexamethasone, significantly diminished interleukin (IL)-1beta levels and partially restored IL-10 levels in colon tissues 72 h after colitis induction, but only alpha,beta-amyrin reduced vascular endothelial growth factor expression by immunohistochemistry. The colonic expression of COX-2 at 24 h and that of phospho-NF-kappaB and phospho-CREB (peaking at 6 h) after colitis induction were consistently inhibited by both alpha,beta-amyrin and dexamethasone.

CONCLUSIONS AND IMPLICATIONS

Systemic administration of alpha,beta-amyrin exerted a marked and rapid inhibition of TNBS-induced colitis, related to the local suppression of inflammatory cytokines and COX-2 levels, possibly via inhibition of NF-kappaB and CREB-signalling pathways. Taken together, our data suggest a potential use of alpha,beta-amyrin to control inflammatory responses in bowel disease.

IKK/NF-kappaB signaling in intestinal epithelial cells controls immune homeostasis in the gut

The intestinal epithelium regulates the interaction between commensal bacteria and the immune system not only by providing a physical barrier but also by expressing a number of immunoregulatory and antimicrobial peptides. Recent studies showed that inhibition of IkappaB kinase (IKK)/nuclear factor-kappaB (NF-kappaB) signaling specifically in intestinal epithelial cells in vivo causes the spontaneous development of intestinal inflammation in mice. These findings identify IKK/NF-kappaB signaling in intestinal epithelial cells as an important factor for the maintenance of epithelial integrity and immune homeostasis in the gut.

Patients with ulcerative colitis responding to steroid treatment up-regulate glucocorticoid receptor levels in colorectal mucosa

BACKGROUND AND AIMS

Glucocorticosteroid treatment (GCS) is effective for attacks of ulcerative colitis (UC). However, 25-30% of patients fails to respond and may be considered steroid resistant. Glucocorticoid receptors (GR) mediate the effects of GCS. Colorectal mucosa levels of GR and NF-κB were analysed before, during and after treatment with GCS-compounds.

METHODS

Patients with moderate-severe attacks of ulcerative colitis were included. Patients undergoing colonoscopy with normal finding served as controls. GR and NF-κB levels in colorectal mucosa were analysed by Western Blotting and the DNA-binding activity of NF-κB by EMSA.

RESULTS

Twenty-eight patients and seven controls were included. Ten patients were judged clinically steroid resistant. Responders had significantly higher levels of GR in colorectal mucosa after one week of treatment than non-responders (P=0.039) and significantly higher levels of GR were found in responders in remission as compared to before treatment (P=0.013). NF-κB levels did not differ between the groups at first visit. Increasing levels were found only in responders as remission was obtained (P=0.031). EMSA detected 20% lower DNA-binding of NF-κB in responders in remission as compared to first visit (P=0.021).

CONCLUSION

GR levels increase in UC-patients responding to GCS-therapy but not in steroid resistant patients and may be the reason for the lack of steroid-efficacy. Increasing NF-κB levels were found in responders attaining remission, possibly reflecting a lower turnover. A decrease in DNA-binding of NF-κB was found in these patients, perhaps because of the increased GR levels counteracting NF-κB activity.

Colitis and cancer: a tale of inflammatory cells and their cytokines

Chronic inflammatory disorders are often associated with an increased cancer risk. A particularly striking example of the chronic inflammation-cancer link is seen in inflammatory bowel disease, in which chronic colitis or persistent inflammation in the colon is associated with elevated risk of colorectal cancer. Animal models exploring the mechanisms by which inflammation increases the risk of colon cancer have shown that inflammatory cells, through the effects of the cytokines they produce, have a major role in promoting neoplastic transformation. In this issue of the JCI, Popivanova and colleagues demonstrate that TNF-alpha, through its effects on the immune system, plays a critical role in promoting neoplastic transformation in this setting (see the related article beginning on page 560). Importantly, the study also provides evidence that anti-TNF-alpha therapies, which are currently in clinical use, may interrupt the process.

Amelioration of chronic murine colitis by peptide-mediated transduction of the IkappaB kinase inhibitor NEMO binding domain peptide

The NF-kappaB family of transcription factors is a central regulator of chronic inflammation. The phosphorylation of IkappaB proteins by the IkappaB kinase (IKK) complex (IKKalpha, IKKbeta, and NF-kappaB essential modulator or NEMO) is a key step in NF-kappaB activation. Peptides corresponding to the NEMO binding domain (NBD) of IKK blocks NF-kappaB activation without inhibiting basal NF-kappaB activity. In this report, we determined the effects of the IKK inhibitor peptide (NBD) in a model of spontaneously occurring chronic murine colitis, the IL-10-deficient (IL-10(-/-)) mouse. Using a novel cationic peptide transduction domain (PTD) consisting of eight lysine residues (8K), we were able to transduce the NBD peptide into cells and tissues. In a NF-kappaB reporter system, 8K-NBD dose-dependently inhibits TNF-induced NF-kappaB activation. Furthermore, 8K-NBD inhibited nuclear translocation of NF-kappaB family members. In NF-kappaB(EGFP) knock-in mice, 8K-NBD inhibited LPS-activated NF-kappaB (EGFP activity) in the ileum but did not inhibit basal NF-kappaB in Peyer's patches. IL-10(-/-) mice treated systemically with 8K-NBD demonstrate amelioration of established colitis, decreased NF-kappaB activation in the lamina propria, and a reduction in spontaneous intestinal IL-12 p40, TNF, IFN-gamma, and IL-17 production. These results demonstrate that inhibitors of IKK, in particular a PTD-NBD peptide, may be therapeutic in the treatment of inflammatory bowel disease.

Modulation of rat intestinal nuclear factor NF-kappaB by gum arabic

The objective of this study was to test the hypothesis that in an animal model of cathartic-induce intestinal dysfunction the proabsorptive effects of gum arabic (GA) could be associated with modulation of nuclear factor-kappaB (NF-kappaB) and with reduction of the inflammatory response caused by cathartics, as evidenced by intestinal mucosa cytokine production and gene expression. Juvenile male rats were given a phenolphthalein-magnesium citrate solution for 6 days, by itself or supplemented with either 10 or 20 g L(-1) GA, as a sole source of fluid. The controls given were tap water alone or with added 20 g L(-1) GA. The animals were euthanized and small-intestinal mucosa nuclear fractions and RNA were isolated. NF-kappaB p65 activity was highest after administration of cathartics, lowest in controls, and intermediate in GA-treated rats. Mucosal IL-1beta was overexpressed in tissues from cathartic-treated rats and from rats given high-GA solutions. Gene-array analysis revealed a complex pattern of gene regulation by cathartics which selectively upregulated several subfamilies of cytochrome P-450 family 2 genes. Co-administration of GA did not block this effect. These findings suggest that local anti-inflammatory effects on the small intestine could be obtained by administration of a nonabsorbable proteoglycan such as GA.

Lack of association of the 3'-UTR polymorphism in the NFKBIA gene with Crohn's disease in an Israeli cohort

BACKGROUND

Crohn's disease (CD) is a chronic inflammatory disease of the gastrointestinal tract associated with dysregulation of the immune response. It is caused by a combination of environmental and genetic factors. Patients with CD have a TH1-type inflammatory response characterized by nuclear factor kappa B (NFkappaB) activation. Mutations in the bacterial pattern recognition receptors NOD2/CARD15 and Toll-like receptor 4 (TLR4) genes, which lead to activation of NFkappaB under normal circumstances, have been associated with increased susceptibility for CD. NFkappaB plays a critical role in the immune response and is down-regulated by NFkappaB inhibitor alpha (NFKBIA). NFKBIA was found to be a susceptibility gene for German CD patients lacking NOD2/CARD15 mutations.

MATERIALS AND METHODS

A cohort of 231 Israeli CD patients previously genotyped for the single nucleotide polymorphisms (SNPs) in the CARD15, TLR4 susceptibility genes for CD, was analyzed for the 3'-untranslated region (UTR) SNP of the NFKBIA gene in comparison to 100 healthy ethnically matched controls. We evaluated the contribution of the 3'-UTR SNP in NFKBIA in patients with or without other SNPs in CARD15 to age of onset, disease location, and disease behavior (Vienna classification).

RESULTS

We did not identify a significant difference in allele and genotype frequencies between either groups or an effect on phenotype. No interactions were found between NFKBIA and any NOD2.

CONCLUSIONS

The contribution of population diversity to susceptibility genes for CD plays an important role in disease-associated variants and is important for better understanding of the pathologic mechanisms of the polymorphism.

Induction of IL-13 triggers TGF-beta1-dependent tissue fibrosis in chronic 2,4,6-trinitrobenzene sulfonic acid colitis

To investigate the immunopathogenesis of inflammation-associated fibrosis, we analyzed the chronic colitis and late-developing fibrosis occurring in BALB/c mice administered weekly doses of intrarectal 2,4,6-trinitrobenzene sulfonic acid. We showed first in this model that an initial Th1 response involving IL-12p70 and IFN-gamma subsides after 3 wk to be supplanted by an IL-23/IL-25 response beginning after 4-5 wk. This evolution is followed by gradually increasing production of IL-17 and cytokines ordinarily seen in a Th2 response, particularly IL-13, which reaches a plateau at 8-9 wk. In vitro stimulation studies suggest that this IL-13 production is dependent on IL-23 and IL-25, but not on IL-12p70. We then show that IL-13 production results in the induction of an IL-13R formerly thought to function only as a decoy receptor, IL-13Ralpha(2), and this receptor is critical to the production of TGF-beta(1) and the onset of fibrosis. Thus, if IL-13 signaling through this receptor is blocked by administration of soluble IL-13Ralpha(2)-Fc, or by administration of IL-13Ralpha(2)-specific small interfering RNA, TGF-beta(1) is not produced and fibrosis does not occur. These studies show that in chronic 2,4,6-trinitrobenzene sulfonic acid colitis, fibrosis is dependent on the development of an IL-13 response that acts through a novel cell surface-expressed IL-13R to induce TGF-beta(1). A similar mechanism may obtain in certain forms of human inflammatory bowel disease.

Posttranslationally modified proteins as mediators of sustained intestinal inflammation

Oxidative and carbonyl stress leads to generation of N(epsilon)-carboxymethyllysine-modified proteins (CML-mps), which are known to bind the receptor for advanced glycation end products (RAGE) and induce nuclear factor (NF)-kappaB-dependent proinflammatory gene expression. To determine the impact of CML-mps in vivo, RAGE-dependent sustained NF-kappaB activation was studied in resection gut specimens from patients with inflammatory bowel disease. Inflamed gut biopsy tissue demonstrated a significant up-regulation of RAGE and increased NF-kappaB activation. Protein extracts from the inflamed zones, but not from noninflamed resection borders, caused perpetuated NF-kappaB activation in cultured endothelial cells, which was mediated by CML-mps including CML-modified S100 proteins. The resulting NF-kappaB activation, lasting 5 days, was primarily inhibited by either depletion of CML-mps or by the addition of sRAGE, p44/42 and p38 MAPKinase-specific inhibitors. Consistently, CML-mps isolated from inflamed gut areas and rectally applied into mice caused NF-kappaB activation, increased proinflammatory gene expression, and histologically detectable inflammation in wild-type mice, but not in RAGE-/- mice. A comparable up-regulation of NF-kappaB and inflammation on rectal application of CML-mps was observed in IL-10-/- mice. Thus, CML-mps generated in inflammatory lesions have the capacity to elicit a RAGE-dependent intestinal inflammatory response.

Proteasome-mediated degradation of IkappaBalpha and processing of p105 in Crohn disease and ulcerative colitis

Enhanced NF-kappaB activity is involved in the pathology of both forms of inflammatory bowel disease (IBD), Crohn disease (CD) and ulcerative colitis (UC). Here we analyzed the mechanism of proteasome-mediated NF-kappaB activation in CD and UC. Our studies demonstrate that the subunit composition and the proteolytic function of proteasomes differ between UC and CD. High expression of the immunoproteasome subunits beta1i and beta2i is characteristic of the inflamed mucosa of CD. In line with this, we found enhanced processing of NF-kappaB precursor p105 and degradation of inhibitor of NF-kappaB, IkappaBalpha, by immunoproteasomes isolated from the mucosa of CD patients. In comparison with healthy controls and CD patients, UC patients exhibited an intermediate phenotype regarding the proteasome-mediated processing/degradation of NF-kappaB components. Finally, increased expression of the NF-kappaB family member c-Rel in the inflamed mucosa of CD patients suggests that p50/c-Rel is important for IFN-gamma-mediated induction of immunoproteasomes via IL-12-driven Th1 responses. These findings suggest that distinct proteasome subunits influence the intensity of NF-kappaB-mediated inflammation in IBD patients.

Linking stress to inflammation

There is ample evidence for the influence of central nervous system modulation through inflammatory cellular reactions under psychosocial stress. These inflammatory reflexes might be of major influence not only for metabolic and vascular disease but also for many autoimmune diseases for which stress has been reported as a risk factor. In prospective trials on the influence of risk factors for the occurrence of cardiovascular events, both psychosocial stress and autonomic nervous control of the cardiovascular system were shown to have a major impact on event rates. The underlying cause of these findings seems to be explained in part by the direct influences of autonomic reflexes, potentially induced by psychosocial tasks, on the progression of atherosclerosis. Hence, future prospective studies that aim at deciphering the influence of chronic psychosocial stress and autonomic function on the pathogenesis of inflammatory and metabolic disease will need to include neurophysiologic, molecular, and clinical parameters. Because the neuroimmunologic axis can be seen as a system connecting mental states with inflammatory reactions, pro-inflammatory mediators and anti-inflammatory strategies should be studied as such in experimental settings.

Exacerbation of dextran sulfate sodium-induced colitis by dietary iron supplementation: role of NF-kappaB

BACKGROUND

In colitis, iron therapy may be given to treat anemia, but it may also be detrimental based on our previous studies using a rat model with colitis where iron supplementation increased disease activity and oxidative stress. This effect was partially reduced by an antioxidant.

AIMS

The aim of this study was to further evaluate, in rats with dextran sulfate sodium (DSS)-induced colitis, the effect of iron on neutrophilic infiltration, cytokines and nuclear factor kappa-B (NF-kappaB)-associated inflammation and to determine whether the addition of vitamin E would be beneficial.

METHODS

Colitis was induced with DSS at 50 g/l in drinking water for 7 days. DSS rats were randomized to the following: DSS, receiving a control, non-purified diet (iron, 270 mg and DL-alpha-tocopherol acetate, 49 mg/kg); DSS+iron (diet+iron, 3,000 mg/kg); DSS+vitamin E (diet+DL-alpha-tocopherol acetate, 2,000 mg/kg); or the DSS+iron+vitamin E. Colonic inflammation, myeloperoxidase activity (MPO), lipid peroxides (LPO), proinflammatory cytokines [tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, IL-6] and NF-kappaB binding activity were measured.

RESULTS

The DSS+iron group showed a significant increase in inflammatory scores, MPO, TNF-alpha, IL-1, LPO and NF-kappaB activity compared to DSS or DSS+vitamin E. The addition of vitamin E to iron (DSS+iron+vitamin E group) significantly reduced the inflammatory scores, TNF-alpha and IL-6. None of the other parameters were affected.

CONCLUSION

Iron increases disease activity in colitis, and this is associated with oxidative stress, neutrophilic infiltration, increased cytokines and activation of NF-kappaB. This detrimental effect was partially reduced by vitamin E.

Melatonin reduces inflammatory injury through inhibiting NF-kappaB activation in rats with colitis

Proinflammatory mediators are important in the pathogenesis of IBD, which are regulated by activation of NF-kappaB. The aim of this study was to investigate whether melatonin reduces inflammatory injury and inhibits proinflammatory molecule and NF-kappaB in rats with colitis. Rat colitis model was established by TNBS enema. NF-kappaB p65, TNF-alpha, ICAM-1, and IkappaBalpha in colon tissue were examined by immunohistochemistry, EMSA, RT-PCR, and Western blot analysis. Expression of proinflammatory molecule and activation of NF-kappaB were upregulated and IkappaB level decreased in rats with colitis. Melatonin reduces colonic inflammatory injury through downregulating proinflammatory molecule mediated by NF-kappaB inhibition and blockade of IkappaBalpha degradation.

NF-kappaB activation precedes increases in mRNA encoding neurokinin-1 receptor, proinflammatory cytokines, and adhesion molecules in dextran sulfate sodium-induced colitis in rats

Nuclear factor kappa B (NF-kappa B) plays a key role in initiating inflammation associated with colitis. A systematic study was conducted in the rat DSS colitis model to determine the temporal relationship between NF-kappa B activation and expression of substance P (SP), neurokinin-1 receptor (NK-1R), proinflammatory cytokines, and adhesion molecules. Rats were given 5% DSS in their water and sacrificed daily for 6 days. Colon tissue was collected for assessment of histological changes, NF-kappa B activation, myeloperoxidase (MPO) activity, and expression of NK-1R, SP, TNFalpha, IL-1beta, VCAM-1, ICAM-1, E-selectin, CINC-1, MIP-1alpha, and iNOS. NF-kappa B activation increased, biphasically, on Day 1 and again on Days 4-6. The mRNA levels for ICAM-1, CINC-1, IL-1beta, TNFalpha, VCAM-1, and NK-1R rose significantly (P < 0.05) by 2-4 days. Increased iNOS mRNA levels, MPO activity, and mucosal damage occurred on Day 6. These data demonstrate that NF-kappa B activation substantially precedes the onset of physical disease signs and active inflammation.

Treatment of Experimental Septic Shock with Microencapsulated Antisense Oligomers to NF-κB

NF-kappaB is an ideal target for inhibition of proinflammatory cytokines. The purpose of this study was to determine if microencapsulated antisense oligomer to NF-kappaB can inhibit proinflammatory cytokine release in response to Escherichia coli endotoxin and bacteria. Microencapsulation takes advantage of the phagocytic function of the macrophage to deliver the oligomer intracellularly and enhance the effect. Albumin microcapsules 1 microm in size were prepared by a nebulization method containing antisense oligomers to NF-kappaB. E. coli endotoxin was incubated in 1 ml aliquots of whole blood. Microencapsulated antisense to NF-kappaB was given, and the inhibition of tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-6, and IL-8 was compared with similar amounts of oligomer in solution. Endotoxic shock was produced in rats using E. coli endotoxin (15 mg/kg). Peritonitis was induced by injecting 10(10) CFU E. coli. Cytokines were measured after simultaneous and delayed (4 h) administration of antisense to NF-kappaB in microcapsules and solution form. TNF was suppressed by 81% in whole blood, 56% in the endotoxic shock model, 89% in the peritonitis model (simultaneous treatment), and 56% in the delayed treatment group. Survival was 70% in the endotoxic shock group, 80% in the simultaneous peritonitis group, and 70% in the delayed treatment group. Microcapsule treatment using antisense to NF-kappaB suppressed TNF and IL-1 levels and mortality significantly better than all solution treatment groups in the whole blood model, endotoxic shock model, and peritonitis model.

Expressions of intestinal NF-kappaB, TNF-alpha, and IL-6 following traumatic brain injury in rats

BACKGROUND

NF-kappaB regulates a large number of genes involved in the inflammatory response to critical illness, but it is not well known if and how NF-kappaB is activated in the gut following traumatic brain injury (TBI) and what is the role of cytokine-mediated inflammation in the pathogenesis of acute gut mucosal injury.

MATERIALS AND METHODS

Male Wistar rats were randomly divided into control and TBI groups, each of which was subgrouped at hours 3, 12, 24, and 72 and on day 7. Parietal brain contusion was produced by a free-falling weight on the exposed dura of the right parietal lobe. NF-kappaB binding activity in jejunal tissue was measured using EMSA and the concentrations of TNF-alpha and IL-6 were detected using ELISA.

RESULTS

NF-kappaB binding activity in the jejunum was significantly increased at 3 h following TBI, was maximal at 72 h, and remained elevated by 7 days postinjury. TNF-alpha and IL-6 concentrations were also significantly increased by 3 h postinjury, but peaked at 24 h and remained elevated on Day 7 postinjury.

CONCLUSIONS

TBI induced a rapid and persistent up-regulation of NF-kappaB and proinflammatory cytokines in the gut, which may play an important role in the pathogenesis of acute gut mucosal injury mediated by inflammation.

MAdCAM-1 expression and regulation in murine colonic endothelial cells in vitro

BACKGROUND

Although the mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is associated with the etiology of inflammatory bowel diseases, few studies have directly examined MAdCAM-1 using microvascular endothelium derived from the colon. This study measured the expression of MAdCAM-1 in a novel colon endothelial line MJC-1, as well as MAdCAM-1 regulation and function in vitro.

METHODS

We cloned microvascular endothelial cells from primary colon cultures using ImmortoMice mice (whose cells express a temperature-sensitive SV40 large T antigen, H-2Kb-tsA58 mice). Expression of MAdCAM-1 after stimulation with cytokines [tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, or interferon (IFN)-gamma] was determined by Western blotting. Signal paths regulating MAdCAM-1 expression were examined using pharmacological blockers before cytokines. We also examined lymphocyte adhesion using lymphocytes that constitutively express alpha4beta7 integrin.

RESULTS

TNF-alpha induced MAdCAM-1 in a dose-dependent manner by 24 hours. MAdCAM-1 induction was protein kinase C, tyrosine kinase, p38 mitogen activated protein kinase, and nuclear-factor kappa-B/poly adenosine diphosphate ribose polymerase dependent. Lymphocyte adhesion was increased 2.6-fold after TNF-alpha stimulation and was inhibited by anti-MAdCAM-1 antibody before treatment (P < 0.05 control versus TNF-alpha).

CONCLUSIONS

In vitro, MAdCAM-1 can be induced on colon endothelial cells by TNF-alpha stimulation and may represent a useful model to study microvascular injury in the large intestine.

Up-regulation of intestinal nuclear factor kappa B and intercellular adhesion molecule-1 following traumatic brain injury in rats

AIM: Nuclear factor kappa B (NF-κB) regulates a large number of genes involved in the inflammatory response to critical illnesses, but it is not known if and how NF-κB is activated and intercellular adhesion molecule-1 (ICAM-1) expressed in the gut following traumatic brain injury (TBI). The aim of current study was to investigate the temporal pattern of intestinal NF-κB activation and ICAM-1 expression following TBI.

METHODS: Male Wistar rats were randomly divided into six groups (6 rats in each group) including controls with sham operation and TBI groups at hours 3, 12, 24, and 72, and on d 7. Parietal brain contusion was adopted using weight-dropping method. All rats were decapitated at corresponding time point and mid-jejunum samples were taken. NF-κB binding activity in jejunal tissue was measured using EMSA. Immunohistochemistry was used for detection of ICAM-1 expression in jejunal samples.

RESULTS: There was a very low NF-κB binding activity and little ICAM-1 expression in the gut of control rats after sham surgery. NF-κB binding activity in jejunum significantly increased by 160% at 3 h following TBI (P<0.05 vs control), peaked at 72 h (500% increase) and remained elevated on d 7 post-injury by 390% increase. Compared to controls, ICAM-1 was significantly up-regulated on the endothelia of microvessels in villous interstitium and lamina propria by 24 h following TBI and maximally expressed at 72 h post-injury (P<0.001). The endothelial ICAM-1 immunoreactivity in jejunal mucosa still remained strong on d 7 post-injury. The peak of NF-κB activation and endothelial ICAM-1 expression coincided in time with the period during which secondary mucosal injury of the gut was also at their culmination following TBI.

CONCLUSION: TBI could induce an immediate and persistent up-regulation of NF-κB activity and subsequent up-regulation of ICAM-1 expression in the intestine. Inflammatory response mediated by increased NF-κB activation and ICAM-1 expression may play an important role in the pathogenesis of acute gut mucosal injury following TBI.