Proinflammatory effects and molecular mechanisms of interleukin-17 in intestinal epithelial cell line HT-29

AIM: To evaluate the proinflammatory effects and molecular mechanisms of interleukin (IL)-17 in intestinal epithelial cell line HT-29.METHODS: HT-29 cells were cultured with IL-17, tumor necrosis factor (TNF)-α, or the combination of both IL-17 and TNF-α. Real-time PCR and Western blot were used to measure the gene expression levels of neutrophil chemokines CXCL1, CXCL2, CXCL5, CXCL6, IL-8 and TH-17 cell chemokine CCL20, the phosphorylation levels of p38 and TNF-α, and the expression level of IL-8, after using the p38 inhibitor in HT-29 cells. The stable Act1 knockdown HT-29 cell line was established to further test the phosphorylation changes of p38, after using IL-17 and TNF-α.RESULTS: After HT-29 cells were cultured with IL-17 and TNF-α, the expression levels of neutrophil chemokines (CXCL1, CXCL2, CXCL5, CXCL6, IL-8) and Th17 chemokine (CCL20) significantly improved (24.96 ± 2.53, 28.47 ± 2.87, 38.08 ± 2.72, 33.47 ± 2.41, 31.7 ± 2.38, 44.37 ± 2.73, respectively), and the differences were all statistically significant (P < 0.01). Western blot results showed that IL-17 obviously enhanced the phosphorylation level of p38, which was induced by TNF-α. Compared with the control group, the expression level of IL-8 significantly declined (9.47 ± 1.36 vs 3.06 ± 0.67, P < 0.01) when TH-29 cells were cultured with IL-17 and TNF-α. p38 inhibition assay showed that the p38 pathway played an essential role in the inflammatory response induced by IL-17. p38 phosphorylation levels could not be changed after using IL-17 and TNF-α in the stable Act1 knockdown HT-29 cell line.CONCLUSION: IL-17 significantly promoted the gene expression levels of TNF-α-induced neutrophil chemokines and Th17 cell chemokine. It is obvious that IL-17 and TNF-α have synergistic effects on p38.     

Galectin-9 and Interferon-Gamma Are Released by Natural Killer Cells upon Activation with Interferon-Alpha and Orchestrate the Suppression of Hepatitis C Virus Infection

Natural killer (NK) cells mount an immune response against hepatitis C virus (HCV) infection and can be activated by several cytokines, including interleukin-2 (IL-2), IL-15, and interferon-alpha (IFN-α). By exploiting the Huh7.5 hepatoma cell line infected with the HCV JFH1 genome, we provide novel insights into the antiviral effector functions of human primary NK cells after cytokine stimulation. NK cells activated with IFN-α (IFNα-NKs) had enhanced contact-dependent and -independent responses as compared with NK cells activated with IL-2/IL-15 (IL2/IL15-NKs) and could inhibit HCV replication both in vitro and in vivo. Importantly, IFN-α, but not IL-2/IL-15, protected NK cells from the functional inhibition exerted by HCV. By performing flow cytometry, multiplex cytokine profiling, and mass-spectrometry-based proteomics, we discovered that IFNα-NKs secreted high levels of galectin-9 and interferon-gamma (IFN-γ), and by conducting neutralization assays, we confirmed the major role of these molecules in HCV suppression. We speculated that galectin-9 might act extracellularly to inhibit HCV binding to host cells and downstream infection. In silico approaches predicted the binding of HCV envelope protein E2 to galectin-9 carbohydrate-recognition domains, and co-immunoprecipitation assays confirmed physical interaction. IFN-γ, on the other hand, triggered the intracellular expressions of two antiviral gate-keepers in target cells, namely, myxovirus-1 (MX1) and interferon-induced protein with tetratricopeptide repeats 1 (IFIT1). Collectively, our data add more complexity to the antiviral innate response mediated by NK cells and highlight galectin-9 as a key molecule that might be exploited to neutralize productive viral infection.     

Human Adenovirus Type 26 Induced IL-6 Gene Expression in an αvβ3 Integrin- and NF-κB-Dependent Manner

The low seroprevalent human adenovirus type 26 (HAdV26)-based vaccine vector was the first adenovirus-based vector to receive marketing authorization from European Commission. HAdV26-based vaccine vectors induce durable humoral and cellular immune responses and, as such, represent a highly valuable tool for fighting infectious diseases. Despite well-described immunogenicity in vivo, the basic biology of HAdV26 still needs some refinement. The aim of this study was to determine the pro-inflammatory cytokine profile of epithelial cells infected with HAdV26 and then investigate the underlying molecular mechanism. The expression of studied genes and proteins was assessed by quantitative polymerase chain reaction, western blot, and enzyme-linked immunosorbent assay. Confocal microscopy was used to visualize HAdV26 cell uptake. We found that HAdV26 infection in human epithelial cells triggers the expression of pro-inflammatory cytokines and chemokines, namely IL-6, IL-8, IL-1β, and TNF-α, with the most pronounced difference shown for IL-6. We investigated the underlying molecular mechanism and observed that HAdV26-induced IL-6 gene expression is αvβ3 integrin dependent and NF-κB mediated. Our findings provide new data regarding pro-inflammatory cytokine and chemokine expression in HAdV26-infected epithelial cells, as well as details concerning HAdV26-induced host signaling pathways. Information obtained within this research increases our current knowledge of HAdV26 basic biology and, as such, can contribute to further development of HAdV26-based vaccine vectors.     

Mucosal healing effect of nilotinib in indomethacin-induced enterocolitis: A rat model

AIM: To investigate the effects of nilotinib in a rat model of indomethacin-induced enterocolitis.METHODS: Twenty-one Wistar albino female rats obtained from Dokuz Eylul University Department of Laboratory Animal Science were divided into the following three groups: control(n = 7), indomethacin(n = 7) and nilotinib(n = 7). A volume of 0.25 m L of physiological serum placebo was administered to the control and indomethacin groups through an orogastric tube for 13 d. To induce enterocolitis, the indomethacin and nilotinib groups received 7.5 m L/kg indomethacin dissolved in 5% sodium bicarbonate and administered subcutaneously in a volume of 0.5 m L twice daily for three days. Nilotinib was administered 20 mg/kg/d in two divided doses to the nilotinib group of rats for 13 d through an orogastric tube, beginning on the same day as indomethacin administration. For 13 d, the rats werefed a standard diet, and their weights were monitored daily. After the rats were sacrificed, the intestinal and colonic tissue samples were examined. The macroscopic and microscopic pathology scores were evaluated. The pathologist stained all tissue samples using terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick-end labeling method. Mucosal crypts and apoptotic cells were quantified. The plateletderived growth factor receptor(PDGFR) α and β scores assessed by immunohistochemical staining method and tissue and serum tumor necrosis factor(TNF) α levels were determined by enzyme-linked immunosorbent assay. RESULTS: Between days 1 and 13, the rats in the nilotinib and indomethacin groups lost significantly more weight than the controls(-11 g vs +14.14 g, P = 0.013;-30 g vs +14.14 g, P = 0.003). In the small intestinal and colonic tissues, the macroscopic scores were significantly lower in the nilotinib group than in the indomethacin group(1.14 ± 0.38 and 7.29 ± 2.98, P = 0.005; 1.14 ± 0.38 and 7.43 ± 2.64, P = 0.001, respectively), but the values of the nilotinib and indomethacin groups were similar to the control group. In the small intestinal and colonic tissues, the microscopic scores were significantly lower in the nilotinib group than in the indomethacin group(3.43 ± 2.99 and 7.67 ± 3.67, P = 0.043; 2.29 ± 0.76 and 8.80 ± 2.68, P = 0.003, respectively), but the values were similar to the control group. The PDGFR β scores in the small intestine and colon were significantly lower in the nilotinib group than in the indomethacin group(1.43 ± 0.79 and 2.43 ± 0.54, P = 0.021; 1.57 ± 0.54 and 3 ± 0, P =0.001), and the values were similar to controls. The colonic PDGFR α scores were significantly lower in the nilotinib group than in the indomethacin group(1.71 ± 0.49 and 3 ± 0, P = 0.001). The colonic apoptosis scores were significantly lower in the controls than in the nilotinib group(1.57 ± 1.13 and 4 ± 1.29, P = 0.007). Furthermore, the serum and tissue TNF-α levels were similar between the nilotinib and indomethacin groups.C O N C L U S I O N : In the indomethacin-induced enterocolitis rat model, nilotinib has a positive effect on the macroscopic and microscopic pathologic scores, ensuring considerable mucosal healing. Nilotinib decreases PDGFR α and β levels and increases the colonic apoptotic scores, but it has no significant effects on weight loss and the TNF-α levels.     

Therapeutic effect of a hydroxynaphthoquinone fraction on dextran sulfate sodium-induced ulcerative colitis

AIM: To evaluate the therapeutic effect of hydroxynaphthoquinone mixture (HM) on dextran sulfate sodium (DSS)-induced colitis and explore the underlying mechanisms.METHODS: BALB/c mice received 3.5% DSS for 6 d to induce ulcerative colitis. Groups of mice were orally administered HM 3.5, 7 and 14 mg/kg and mesalazine 200 mg/kg per day for 7 d. During the experiment, clinical signs and body weight, stool consistency and visible fecal blood were monitored and recorded daily. A disease activity index score was calculated for each animal. At the conclusion of the experiment, the colonic histopathological lesions were evaluated. Myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) levels were determined. Protein expression levels of TNF-α, nuclear factor-κB (NF-κB) p65, inhibitor of κB (IκB) and phosphorylation of IκB (p-IκB) were analyzed by Western blot analysis.RESULTS: Administration of 3.5% DSS for 6 d successfully induced acute colitis associated with soft stool, diarrhea, rectal bleeding, and colon shortening, as well as a loss of body weight. Administration of HM effectively attenuated the severity of colonic mucosa injury. For histopathological analysis, HM treatment improved histological alterations and lowered pathological scores compared with the DSS only group. This manifested as a reduction in the extent of colon injury and inflammatory cell infiltration, as well as the degree of mucosal destruction. In addition, HM at doses of 7 and 14 mg/kg significantly decreased MPO activity in colonic tissue (0.98 ± 0.22 U/g vs 1.32 ± 0.24 U/g, 0.89 ± 0.37 U/g vs 1.32 ± 0.24 U/g tissue, P < 0.05) and serum TNF-α levels (68.78 ± 7.34 ng/L vs 88.98 ± 17.79 ng/L, 64.13 ± 14.13 ng/L vs 88.98 ± 17.79 ng/L, P < 0.05). Furthermore, HM down-regulated the expression of TNF-α, NF-κB p65 and p-IκBα in colonic tissue while up-regulating IκBα protein expression. These results suggest that the significant anti-inflammatory effect of HM may be attributable to its inhibition of TNF-α production and NF-κB activation.CONCLUSION: HM had a favorable therapeutic effect on DSS-induced ulcerative colitis, supporting its further development and clinical application in inflammatory bowel disease.     

IL-15 receptor α signaling constrains the development of IL-17–producing γδ T cells

The development and homeostasis of γδ T cells is highly dependent on distinct cytokine networks. Here we examine the role of IL-15 and its unique receptor, IL-15Rα, in the development of IL-17–producing γδ (γδ-17) T cells. Phenotypic analysis has shown that CD44^high γδ-17 cells express IL-15Rα and the common gamma chain (CD132), yet lack the IL-2/15Rβ chain (CD122). Surprisingly, we found an enlarged population of γδ-17 cells in the peripheral and mesenteric lymph nodes of adult IL-15Rα KO mice, but not of IL-15 KO mice. The generation of mixed chimeras from neonatal thymocytes indicated that cell-intrinsic IL-15Rα expression was required to limit IL-17 production by γδ T cells. γδ-17 cells also were increased in the peripheral lymph nodes of transgenic knock-in mice, where the IL-15Rα intracellular signaling domain was replaced with the intracellular portion of the IL-2Rα chain (that lacks signaling capacity). Finally, an analysis of neonatal thymi revealed that the CD44^lo/int precursors of γδ-17 cells, which also expressed IL-15Rα, were increased in newborn mice deficient in IL-15Rα signaling, but not in IL-15 itself. Thus, these findings demonstrate that signaling through IL-15Rα regulates the development of γδ-17 cells early in ontogeny, with long-term effects on their peripheral homeostasis in the adult.Both αβ and γδ T cells rely heavily on cytokine signaling for their development and survival. Many of these cytokines belong to the IL-2 cytokine family, whose receptors all share a common γ receptor chain (γ_c; CD132). Among these, IL-15 has a unique, nonredundant role in both T-cell and natural killer (NK)-cell biology, such that CD8⁺ memory T cells and NK cells are absent in IL-15–deficient environments (1, 2). The predominant mechanism through which IL-15 functions is termed transpresentation, whereby IL-15 is preassociated with its specific α-chain (IL-15Rα) inside the cell and presented at the cell surface in trans to a responding cell expressing γ_c and IL-2/15Rβ (CD122) (3–6). IL-15 is unique among its family members owing to its ability to act either in cis or in trans. Whether or not direct signaling (in cis) via IL-15Rα plays a significant biological role in immunobiology has not been resolved (7–11).Certain populations of γδ T cells are known to be sensitive to the availability of IL-15 for their development and/or survival. A population of specialized γδ T cells called dendritic epidermal T cells are absent from the skin of IL-15 knockout (KO) and IL-15Rα KO mice (12, 13). The CD8αα⁺ γδ T-cell receptor (TCR) intraepithelial lymphocytes are also decreased in these two KO mouse strains (1, 2). In addition, IL-15 KO mice have a reduced population of IFN-γ⁺ γδ T cells in the peritoneum (14). All of these populations express CD122, suggesting they can receive IL-15–dependent signals via transpresentation.Recently, γδ T cells have emerged as important contributors to the generation of immune responses. The innate-like γδ T cells that produce IL-17 (γδ-17 cells) have been implicated in immune responses generated during bacterial and fungal infections, experimental autoimmune encephalomyelytois (EAE), psoriasis, and anticancer immunity (reviewed in ref. 15). The γδ-17 subset of γδ T cells has a restricted TCR use that is largely limited to Vγ2 and Vγ4 expression (Garmin nomenclature; Vγ4 and Vγ6 in Tonegawa nomenclature) and a molecularly distinct gene expression profile (16). Considering the strictly regulated developmental progression of γδ T-cell subsets (17), the vast majority of γδ-17 cells are known to emerge during a limited window early in ontogeny, ∼E16.5 up to shortly after birth (18). The exogenous signals that impact γδ-17–cell development during this window remain unclear. Here we identify the IL-15Rα chain as a critical determinant through which γδ-17–cell development is regulated. Furthermore, in contrast to IL-15Rα’s predominant role in the immune system via IL-15 transpresentation, we found IL-15Rα–dependent changes in both neonatal thymic development and peripheral homeostasis in adulthood, suggesting that γδ-17 cells are dependent on cell-intrinsic signals received through IL-15Rα in cis.     

Peroxisome proliferator-activated receptor gamma activation is required for maintenance of innate antimicrobial immunity in the colon

Crohn''s disease (CD), a major form of human inflammatory bowel disease, is characterized by primary immunodeficiencies. The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) is essential for intestinal homeostasis in response to both dietary- and microbiota-derived signals. Its role in host defense remains unknown, however. We show that PPARγ functions as an antimicrobial factor by maintaining constitutive epithelial expression of a subset of β-defensin in the colon, which includes mDefB10 in mice and DEFB1 in humans. Colonic mucosa of Pparγ mutant animals shows defective killing of several major components of the intestinal microbiota, including Candida albicans, Bacteroides fragilis, Enterococcus faecalis, and Escherichia coli. Neutralization of the colicidal activity using an anti-mDefB10 blocking antibody was effective in a PPARγ-dependent manner. A functional promoter variant that is required for DEFB1 expression confers strong protection against Crohn''s colitis and ileocolitis (odds ratio, 0.559; P = 0.018). Consistently, colonic involvement in CD is specifically linked to reduced expression of DEFB1 independent of inflammation. These findings support the development of PPARγ-targeting therapeutic and/or nutritional approaches to prevent colonic inflammation by restoring antimicrobial immunity in CD.     

β-Hydroxybutyrate,One of the Three Main Ketone Bodies,Ameliorates Acute Pancreatitis in Rats by Suppressing the NLRP3 Inflammasome Pathway

BackgroundAcute pancreatitis (AP) is a widespread disease resulting from the inflammation of acinar cells in the pancreas. β-hydroxybutyrate (BHB) is a water-soluble main ketone body synthesized in the human liver. The purpose of this study was to examine the possible therapeutic effects of BHB in the experimentally-induced AP model in rats. MethodsIn our study, male rats were randomly allotted into 6 groups, as control (0.9% saline i.p.), BHB1 (200 mg/kg BHB i.p.), BHB2 (2 doses of 200 mg/kg BHB i.p.), AP (4 doses of 50 µg/kg cerulein i.p., 4 doses at 1 h intervals), AP+BHB1 and AP+BHB2 groups. In pancreatic tissue sections, immunohistochemistry staining and western blot analysis for the inflammasome complex (caspase-1, ASC, and NLRP3) and inflammation-associated proteins (TNF-α and NF-κB) and a histopathological examination were performed. The levels of lipase, amylase, interleukin (IL)-18 and IL-1β in serum were measured. ResultsSeveral pathological degenerations, including edema, inflammatory cell infiltration, acinus necrosis, and bleeding were observed in the AP group, while the histological architecture of the control and the sham BHB1 and BHB2 groups were regular. The AP-induced pathological changes were considerably alleviated in the AP+BHB1 and AP+BHB2 groups. In the AP group, a conspicuous increase in caspase-1, ASC, NLRP3, TNF-α, and NF-κB proteins, and in the levels of amylase, lipase, IL-18, and IL-1β were detected. BHB treatments after AP induction decreased those proteins to the level of control. ConclusionsWe demonstrated that BHB has the potential to cure AP by suppressing the NLRP3 inflammasome and can be used in the treatment of many diseases which progress through the NLRP3 inflammasome.     

Antiviral Cytokine Response in Neuroinvasive and Non-Neuroinvasive West Nile Virus Infection

Data on the immune response to West Nile virus (WNV) are limited. We analyzed the antiviral cytokine response in serum and cerebrospinal fluid (CSF) samples of patients with WNV fever and WNV neuroinvasive disease using a multiplex bead-based assay for the simultaneous quantification of 13 human cytokines. The panel included cytokines associated with innate and early pro-inflammatory immune responses (TNF-α/IL-6), Th1 (IL-2/IFN-γ), Th2 (IL-4/IL-5/IL-9/IL-13), Th17 immune response (IL-17A/IL-17F/IL-21/IL-22) and the key anti-inflammatory cytokine IL-10. Elevated levels of IFN-γ were detected in 71.7% of CSF and 22.7% of serum samples (p = 0.003). Expression of IL-2/IL-4/TNF-α and Th1 17 cytokines (IL-17A/IL-17F/IL-21) was detected in the serum but not in the CSF (except one positive CSF sample for IL-17F/IL-4). While IL-6 levels were markedly higher in the CSF compared to serum (CSF median 2036.71, IQR 213.82–6190.50; serum median 24.48, IQR 11.93–49.81; p < 0.001), no difference in the IL-13/IL-9/IL-10/IFN-γ/IL-22 levels in serum/CSF was found. In conclusion, increased concentrations of the key cytokines associated with innate and early acute phase responses (IL-6) and Th1 type immune responses (IFN-γ) were found in the CNS of patients with WNV infection. In contrast, expression of the key T-cell growth factor IL-2, Th17 cytokines, a Th2 cytokine IL-4 and the proinflammatory cytokine TNF-α appear to be concentrated mainly in the periphery.     

Cytokine Responses to Novel Antigens in a Peri-Urban Population in Brazil Exposed to Leishmania infantum chagasi

Visceral leishmaniasis (VL) is fatal if untreated, and there are no vaccines for this disease. High levels of CD4-derived interferon-γ (IFN-γ) in the presence of low levels of interleukin-10 (IL-10) predicts vaccine success. Tumor necrosis factor-α (TNF-α) is also important in this process. We characterized human immune responses in three groups exposed to Leishmania infantum chagasi in Brazil: 1) drug-cured VL patients (recovered VL); 2) asymptomatic persons with positive Leishmania-specific delayed-type hypersensitivity skin reactions (DTH+); and 3) DTH-negative household contacts. Magnitude of DTH correlated with crude Leishmania antigen–driven IFN-γ, TNF-α, and IL-5, but not IL-10. DTH+ persons showed equivalent levels of IFN-γ, but higher levels of IL-10, to tryparedoxin peroxidase and Leishmania homolog of receptor for activated C kinase compared with recovered VL patients. The IFN-γ:IL-10 and TNF-α:IL-10 ratios were higher in recovered VL patients than in DTH+ persons. Seven of 11 novel candidates (R71, L37, N52, L302.06, M18, J41, and M22) elicited cytokine responses (36–71% of responders) in recovered VL patients and DTH+ persons. This result confirmed their putative status as cross-species vaccine/immunotherapeutic candidates.     

Disruption of TAK1 in hepatocytes causes hepatic injury,inflammation, fibrosis,and carcinogenesis

TGF-β–activated kinase 1 (TAK1) is a MAP3K family member that activates NF-κB and JNK via Toll-like receptors and the receptors for IL-1, TNF-α, and TGF-β. Because the TAK1 downstream molecules NF-κB and JNK have opposite effects on cell death and carcinogenesis, the role of TAK1 in the liver is unpredictable. To address this issue, we generated hepatocyte-specific Tak1-deficient (Tak1ΔHEP) mice. The Tak1ΔHEP mice displayed spontaneous hepatocyte death, compensatory proliferation, inflammatory cell infiltration, and perisinusoidal fibrosis at age 1 month. Older Tak1ΔHEP mice developed multiple cancer nodules characterized by increased expression of fetal liver genes including α-fetoprotein. Cultures of primary hepatocytes deficient in Tak1 exhibited spontaneous cell death that was further increased in response to TNF-α. TNF-α increased caspase-3 activity but activated neither NF-κB nor JNK in Tak1-deficient hepatocytes. Genetic abrogation of TNF receptor type I (TNFRI) in Tak1ΔHEP mice reduced liver damage, inflammation, and fibrosis compared with unmodified Tak1ΔHEP mice. In conclusion, hepatocyte-specific deletion of TAK1 in mice resulted in spontaneous hepatocyte death, inflammation, fibrosis, and carcinogenesis that was partially mediated by TNFR signaling, indicating that TAK1 is an essential component for cellular homeostasis in the liver.     

Polarizing the T helper 17 response in Citrobacter rodentium infection via expression of resistin-like molecule α

Citrobacter rodentium infection is a murine model of pathogenic Escherichia coli infection that allows investigation of the cellular and molecular mechanisms involved in host-protective immunity and bacterial-induced intestinal inflammation. We recently demonstrated that following C. rodentium infection, the absence of Resistin-Like Molecule (RELM) α resulted in attenuated Th17 cell responses and reduced intestinal inflammation with minimal effects on bacterial clearance. In this addendum, we investigated the cytokine modulatory effects of RELMα and RELMα expression in the intestinal mucosa following C. rodentium infection. We show that in addition to promoting Th17 cytokine responses, RELMα inhibits Th2 cytokine expression and Th2-cytokine effector macrophage responses in the C. rodentium-infected colons. Second, utilizing reporter C. rodentium, we examined RELMα expression and macrophage recruitment at the host pathogen interface. We observed infection-induced macrophage infiltration and RELMα expression by intestinal epithelial cells. The influence of infection-induced RELMα on macrophage recruitment in the intestine is discussed.     

Ischemic preconditioning ameliorates intestinal injury induced by ischemia-reperfusion in rats

AIM: To evaluate preventative effects of ischemic preconditioning(IP) in a rat model of intestinal injury induced by ischemia-reperfusion(IR).METHODS: Male Sprague-Dawley rats(250-300 g) were fasted for 24 h with free access to water prior to the operation.Eighteen rats were randomly divided into three experimental groups: S group(n = 6),rats were subjected to isolation of the superior mesenteric artery(SMA) for 40 min,then the abdomen was closed; IRgroup(n = 6),rats were subjected to clamping the SMA 40 min,and the abdomen was closed followed by a 4-h reperfusion; IP group(n = 6) rats underwent three cycles of 5 min ischemia and 5 min reperfusion,then clamping of the SMA for 40 min,then the abdomen was closed and a 4-h reperfusion followed.All animals were euthanized by barbiturate overdose(150 mg/kg pentobarbital sodium,i.v.) for tissue collection,and the SMA was isolated via median abdominal incision.Intestinal histologic injury was observed.Malondialdehyde(MDA),myeloperoxidase(MPO) and tumor necrosis factor(TNF)-a concentrations in intestinal tissue were measured.Intercellular adhesion molecule(ICAM)-1 and vascular cell adhesion molecule(VCAM)-1 expression,as well as nuclear factor(NF)-κB activity and expression in intestinal tissue were also determined.RESULTS: Compared with the IR group,IP reduced IR-induced histologic injury of the intestine in rats(2.00 ± 0.71 vs 3.60 ± 0.84,P 0.05).IP significantly inhibited the increase in MDA content(5.6 ± 0.15 μmol/L vs 6.84 ± 0.18 μmol/L,P 0.01),MPO activity(0.13 ± 0.01 U/L vs 0.24 ± 0.01 U/L,P 0.01),and TNF-a levels(7.79 ± 2.35 pg/m L vs 10.87 ± 2.48 pg/m L,P 0.05) in the intestinal tissue of rats.IP also markedly ameliorated the increase in ICAM-1(204.67 ± 53.27 vs 353.33 ± 45.19,P 0.05) and VCAM-1(256.67 ± 58.59 vs 377.33 ± 41.42,P 0.05) protein expression in the intestinal tissues.Additionally,IP remarkably decreased NF-κB activity(0.48 ± 0.16 vs 0.76 ± 0.22,P 0.05) and protein expression(320.23 ± 38.16 vs 520.76 ± 40.53,P 0.01) in rat intestinal tissue.CONCLUSION: IP may protect against IR-induced intestinal injury by attenuation of the neutrophilendothelial adhesion cascade via reducing ICAM-1 and VCAM-1 expression and TNF-a-induced NF-κB signaling pathway activity.