Systemic and local evidence of increased Fas-mediated apoptosis in ulcerative colitis

Necroptosis contributes to the intestinal toxicity of deoxynivalenol and is mediated by methyltransferase SETDB1

Deoxynivalenol (DON) is a secondary metabolite produced by fungi, which causes serious health issues worldwide due to its widespread presence in human and animal diets. Necroptosis is a newly proposed cell death mode and has been proposed as a potential mechanism of intestinal disease. This study aimed to investigate the role of necroptosis in intestinal damage caused by DON exposure. Piglets were fed diets with or without 4 mg/kg DON for 3 weeks or given a gavage of 2 mg/kg BW DON or sterile saline to investigate the effects of chronic or acute DON exposure on the gut, respectively. IPEC-1 cells were challenged with different concentrations of DON to investigate the effect of DON exposure on the intestinal epithelial cells (IECs) in vitro. Subsequently, the inhibitors of necroptosis were used to treat cells or piglets prior to DON challenge. Chronic and acute DON exposure both caused morphological damage, reduction of disaccharidase activity, decrease of tight junction protein expression, inflammation of the small intestine, and necroptosis of intestinal epithelial cells in piglets. Necroptosis was also detected when IPEC-1 cell damage was induced by DON in vitro. The suppression of necroptosis in IPEC-1 cells by inhibitors (necrostatin-1 (Nec-1), GSK'872, or GW806742X) alleviated cell death, the decrease of tight junction protein expression, oxidative stress, and the inflammatory response induced by DON. Furthermore, pre-treatment with Nec-1 in piglets was also observed to protect the intestine against DON-induced enterotoxicity. Additionally, the expression of histone methyltransferase SETDB1 was abnormally downregulated upon chronic and acute DON exposure in piglets, and necroptosis was activated in IPEC-1 cells due to knockout of SETDB1. Collectively, these results demonstrate that necroptosis of IECs is a mechanism of DON-induced enterotoxicity and SETDB1 mediates necroptosis upon DON exposure in IECs, suggesting the potential for targeted inhibition of necroptosis to alleviate mycotoxin-induced enterotoxicity and intestinal disease.

Effects of Rosa roxburghii Tratt on Ulcerative Colitis: An Integrated Analysis of Network Pharmacology and Experimental Validation

Rosa roxburghii Tratt is a traditional Chinese plant that has been used to treat different inflammatory diseases. The purpose of this study was to investigate the mechanism of action of Rosa roxburghii Tratt extract (RRTE) against ulcerative colitis (UC) using network pharmacology and experimental validation. HPLC-Q/Orbitrap MS was used to rapidly identify the substances contained in RRTE after extracting the active components from the fruit. Then, network pharmacology combined with molecular docking was used to explore the critical target and potential mechanism of RRTE against UC using the active ingredients in RRTE as the research object. Data are presented in a visual manner. Finally, the pharmacological effects of RRTE in alleviating UC were further verified using a DSS-induced UC model of NCM460. The results showed that 25 components in RRTE were identified. A total of 250 targets of the active components and 5376 targets associated with UC were collected. Furthermore, a systematic analysis of the Protein-Protein Interaction (PPI) networks suggests that epidermal growth factor receptor (EGFR), phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1), and serine/threonine kinase 1 (AKT1) are critical targets for RRTE in the treatment of UC. A comprehensive regulatory network analysis showed that RRTE alleviated UC through the EGFR-mediated PI3K/Akt pathway, and molecular docking showed that active components could strongly bind to EGFR, PIK3R1, and AKT1. In addition, RRTE alleviated dextran sulfate sodium salt (DSS)-induced cell injury and significantly decreased the protein expression levels of EGFR, PIK3R1, and p-AKT in NCM460 cells in vitro. Furthermore, RRTE significantly regulated the expression of the apoptosis-related proteins Apoptotic protease-activating factor 1 (Apaf1), cleaved caspase-3, B-cell lymphoma-2 (Bcl2), and Bcl2 associated X protein (Bax). In conclusion, the components of RRTE are complex, and RRTE can relieve UC through the EGFR-mediated PI3K/Akt pathway.

Tackling Inflammatory Bowel Diseases: Targeting Proinflammatory Cytokines and Lymphocyte Homing

Inflammatory bowel diseases (IBDs) are characterized by chronic inflammatory disorders that are a result of an abnormal immune response mediated by a cytokine storm and immune cell infiltration. Proinflammatory cytokine therapeutic agents, represented by TNF inhibitors, have developed rapidly over recent years and are promising options for treating IBD. Antagonizing interleukins, interferons, and Janus kinases have demonstrated their respective advantages in clinical trials and are candidates for anti-TNF therapeutic failure. Furthermore, the blockade of lymphocyte homing contributes to the excessive immune response in colitis and ameliorates inflammation and tissue damage. Factors such as integrins, selectins, and chemokines jointly coordinate the accumulation of immune cells in inflammatory regions. This review assembles the major targets and agents currently targeting proinflammatory cytokines and lymphatic trafficking to facilitate subsequent drug development.

Natural Products Modulate Cell Apoptosis: A Promising Way for the Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease impacting patients’ quality of life and imposing heavy societal and economic burdens. Apoptosis of intestinal epithelial cells (IECs) has been considered an early event during the onset of UC and plays a crucial role in disease development. Thus, effectively inhibiting apoptosis of IECs is of critical significance for the clinical management of UC, presenting a potential direction for the research and development of pharmacotherapeutic agents. In recent years, research on the ameliorative effects of natural products on UC through inhibiting IECs apoptosis has attracted increasing attention and made remarkable achievements in ameliorating UC. In this review, we summarized the currently available research about the anti-apoptotic effects of natural products on UC and its mechanisms involving the death-receptor mediated pathway, mitochondrial-dependent pathway, ERS-mediated pathway, MAPK-mediated pathway, NF-κB mediated pathway, P13k/Akt pathway, JAK/STAT3 pathway, and NLRP3/ASC/Caspase-1 pathway. Hopefully, this review may yield useful information about the anti-apoptotic effects of natural products on UC and their potential molecular mechanisms and provide helpful insights for further investigations.

E-type prostanoid receptor 4 drives resolution of intestinal inflammation by blocking epithelial necroptosis

Inflammatory bowel diseases present with elevated levels of intestinal epithelial cell (IEC) death, which compromises the gut barrier, activating immune cells and triggering more IEC death. The endogenous signals that prevent IEC death and break this vicious cycle, allowing resolution of intestinal inflammation, remain largely unknown. Here we show that prostaglandin E2 signalling via the E-type prostanoid receptor 4 (EP4) on IECs represses epithelial necroptosis and induces resolution of colitis. We found that EP4 expression correlates with an improved IBD outcome and that EP4 activation induces a transcriptional signature consistent with resolution of intestinal inflammation. We further show that dysregulated necroptosis prevents resolution, and EP4 agonism suppresses necroptosis in human and mouse IECs. Mechanistically, EP4 signalling on IECs converges on receptor-interacting protein kinase 1 to suppress tumour necrosis factor-induced activation and membrane translocation of the necroptosis effector mixed-lineage kinase domain-like pseudokinase. In summary, our study indicates that EP4 promotes the resolution of colitis by suppressing IEC necroptosis.

A profile of multiple circulating tumor necrosis factor receptors associated with early progressive kidney decline in Type 1 Diabetes is similar to profiles in autoimmune disorders

This study comprehensively evaluated the association between known circulating tumor necrosis factor (TNF) superfamily ligands and receptors and the development of early progressive kidney decline (PKD) leading to end-stage kidney disease (ESKD) in Type 1 diabetes. Participants for the study were from the Macro-Albuminuria Study (198 individuals), and the Micro-Albuminuria Study (148 individuals) of the Joslin Kidney Study. All individuals initially had normal kidney function and were followed for seven-fifteen years to determine the slope of the estimate glomerular filtration rate and to ascertain onset of ESKD. Plasma concentrations of 25 TNF superfamily proteins were measured using proximity extension assay applied in the OLINK proteomics platform. In the both studies risk of early PKD, determined as estimated glomerular filtration rate loss greater than or equal to three ml/min/1.73m2/year, was associated with elevated circulating levels of 13 of 19 TNF receptors examined. In the Macro-Albuminuria Study, we obtained similar findings for risk of progression to ESKD. These receptors comprised: TNF-R1A, -R1B, -R3, -R4, -R6, -R6B, -R7, -R10A, -R10B, -R11A, -R14, -R21, and -R27. Serial measurements showed that circulating levels of these TNF receptors had increased before the onset of PKD. In contrast, none of the six measured TNF ligands showed association with risk of early PKD. Of significance, the disease process that underlies PKD leading to ESKD in Type 1 diabetes has a profile also seen in autoimmune disorders. The mechanisms of this enrichment may be causally related to the development of PKD in Type 1 diabetes and must be investigated further. Thus, some of these receptors may be used as new risk predictors of ESKD.

Molecular pathways driving disease-specific alterations of intestinal epithelial cells

Due to the fact that chronic inflammation as well as tumorigenesis in the gut is crucially impacted by the fate of intestinal epithelial cells, our article provides a comprehensive overview of the composition, function, regulation and homeostasis of the gut epithelium. In particular, we focus on those aspects which were found to be altered in the context of inflammatory bowel diseases or colorectal cancer and also discuss potential molecular targets for a disease-specific therapeutic intervention.

Tumour necrosis factor superfamily members in the pathogenesis of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the gastrointestinal tract of unclear aetiology of which two major forms are Crohn's disease (CD) and ulcerative colitis (UC). CD and UC are immunologically distinct, although they both result from hyperactivation of proinflammatory pathways in intestines and disruption of intestinal epithelial barrier. Members of the tumour necrosis factor superfamily (TNFSF) are molecules of broad spectrum of activity, including direct disruption of intestinal epithelial barrier integrity and costimulation of proinflammatory functions of lymphocytes. Tumour necrosis factor (TNF) has a well-established pathological role in IBD which also serves as a target in IBD treatment. In this review we discuss the role of TNF and other TNFSF members, notably, TL1A, FasL, LIGHT, TRAIL, and TWEAK, in the pathogenesis of IBD.

Functional comparison between genes dysregulated in ulcerative colitis and colorectal carcinoma

Background

Patients with ulcerative colitis (UC) are predisposed to colitis-associated colorectal cancer (CAC). However, the transcriptional mechanism of the transformation from UC to CAC is not fully understood.

Methodology

Firstly, we showed that CAC and non-UC-associated CRC were very similar in gene expression. Secondly, based on multiple datasets for UC and CRC, we extracted differentially expressed (DE) genes in UC and CRC versus normal controls, respectively. Thirdly, we compared the dysregulation directions (upregulation or downregulation) between DE genes of UC and CRC in CRC-related functions overrepresented with the DE genes of CRC, and proposed a regulatory model to explain the CRC-like dysregulation of genes in UC. A case study for “positive regulation of immune system process” was done to reveal the functional implication of DE genes with reversal dysregulations in these two diseases.

Principal Findings

In all the 44 detected CRC-related functions except for “viral transcription”, the dysregulation directions of DE genes in UC were significantly similar with their counterparts in CRC, and such CRC-like dysregulation in UC could be regulated by transcription factors affected by pro-inflammatory stimuli for colitis. A small portion of genes in each CRC-related function were dysregulated in opposite directions in the two diseases. The case study showed that genes related to humoral immunity specifically expressed in B cells tended to be upregulated in UC but downregulated in CRC.

Conclusions

The CRC-like dysregulation of genes in CRC-related functions in UC patients provides hints for understanding the transcriptional basis for UC to CRC transition. A small portion of genes with distinct dysregulation directions in each of the CRC-related functions in the two diseases implicate that their reversal dysregulations might be critical for UC to CRC transition. The cases study indicates that the humoral immune response might be inhibited during the transformation from UC to CRC.

Serum and tissue CD23, IL-15, and FasL in cow's-milk protein-sensitive enteropathy and in coeliac disease

OBJECTIVES

The aim of the study was to explore pathogenesis and find new serum markers for cow's-milk-sensitive enteropathy (CMSE) and coeliac disease (CD). We assessed the intestinal expression and serum concentration of CD23, IL-15, and FasL. We hypothesised that the serum levels of CD23, a protein expressed in the lymphoid follicles, would be associated with lymphonodular hyperplasia (LNH), a feature characteristic of CMSE. We also presumed that interleukin (IL)-15 and FasL, functionally connected with proliferation and apoptosis of the intraepithelial lymphocytes (IELs), would relate with the increased numbers of IELs present in both CMSE and CD.

METHODS

Twenty-three children with CMSE, 20 with untreated CD, and 14 controls were studied for CD3, α/β- and γ/δ-expressing IELs, and for duodenal and ileal expression of CD23, FasL, and IL-15 by immunohistochemistry, and for serum concentration of sCD23, sFasL, and sIL-15 by enzyme-linked immunosorbent assay.

RESULTS

There was a trend for increase in sCD23 serum levels in untreated CMSE and in CD (P = 0.074; P = 0.077). CD23 was expressed in the mucosal germinal centres, but sCD23 was not related to presence of LNH. In CMSE, there was a trend for increase in serum sFasL (P = 0.07) and high levels associated with LNH (P = 0.025) and correlated with the IEL numbers (P < 0.05). Mucosal high endothelial venules adjacent to lymphoid follicles showed an intensive FasL expression.

CONCLUSIONS

Serum sCD23 shows a trend of increment in CMSE and CD, and in the latter, sCD23 level may provide information about the severity of villous atrophy. In CMSE, high serum sFasL indicates both LNH and an increase of IELs, suggesting importance of FasL-mediated mechanisms in the pathogenesis of these features characteristic of CMSE. Further studies are necessary to evaluate whether intensive FasL expression in mucosal high endothelial venules presents a regulatory element in mucosal immunity.

Hydroxylase inhibition abrogates TNF-alpha-induced intestinal epithelial damage by hypoxia-inducible factor-1-dependent repression of FADD

Hydroxylase inhibitors stabilize hypoxia-inducible factor-1 (HIF-1), which has barrier-protective activity in the gut. Because the inflammatory cytokine TNF-α contributes to inflammatory bowel disease in part by compromising intestinal epithelial barrier integrity, hydroxylase inhibition may have beneficial effects in TNF-α-induced intestinal epithelial damage. The hydroxylase inhibitor dimethyloxalylglycin (DMOG) was tested in a murine model of TNF-α-driven chronic terminal ileitis. DMOG-treated mice experienced clinical benefit and showed clear attenuation of chronic intestinal inflammation compared with that of vehicle-treated littermates. Additional in vivo and in vitro experiments revealed that DMOG rapidly restored terminal ileal barrier function, at least in part through prevention of TNF-α-induced intestinal epithelial cell apoptosis. Subsequent transcriptional studies indicated that DMOG repressed Fas-associated death domain protein (FADD), a critical adaptor molecule in TNFR-1-mediated apoptosis, in an HIF-1α-dependent manner. Loss of this FADD repression by HIF-1α-targeting small interfering RNA significantly diminished the antiapoptotic action of DMOG. Additional molecular studies led to the discovery of a previously unappreciated HIF-1 binding site in the FADD promoter, which controls repression of FADD during hypoxia. As such, the results reported in this study allowed the identification of an innate mechanism that protects intestinal epithelial cells during (inflammatory) hypoxia, by direct modulation of death receptor signaling. Hydroxylase inhibition could represent a promising alternative treatment strategy for hypoxic inflammatory diseases, including inflammatory bowel disease.

T300A polymorphism of ATG16L1 and susceptibility to inflammatory bowel diseases: A meta-analysis

AIM: To evaluate the association of the autophagy-related 16-like 1 (ATG16L1) T300A polymorphism (rs2241880) with predisposition to inflammatory bowel diseases (IBD) by means of meta-analysis.

METHODS: Publications addressing the relationship between rs2241880/T300A polymorphism of ATG16L1 and Crohn’s disease (CD) and ulcerative colitis (UC) were selected from the MEDLINE and EMBASE databases. To make direct comparisons between the data collected in these studies, the individual authors were contacted when necessary to generate a standardized set of data from these studies. From these data, odds ratio (OR) with 95% confidence interval (CI) were calculated.

RESULTS: Twenty-five studies of CD were analyzed, 14 of which involved cases of UC. The variant G allele of ATG16L1 was positively associated with CD (OR = 1.32, 95% CI: 1.26-1.39, P < 0.00001) and UC (OR = 1.06, 95% CI: 1.01-1.10, P = 0.02). For child-onset IBD, a higher G allele frequency was found for cases of CD (OR = 1.35, 95% CI: 1.16-1.57, P = 0.0001) than for cases of UC (OR = 0.98, 95% CI: 0.81-1.19, P = 0.84) relative to controls.

CONCLUSION: The ATG16L1 T300A polymorphism contributes to susceptibility to CD and UC in adults, but different in children, which implicates a role for autophagy in the pathogenesis of IBD.

Advance in enteric epithelial barrier and inflammatory bowel disease

Enteric epithelial barrier injury is a new field of the study on the cellular and molecular pathegenesis of inflammatory bowel disease (IBD) in recent years. The enteric epithelial barrier is one of the most important line of defense. Once the enteric epithelial barrier, one of the most important defense line in intestinal mucosa, is damaged, the permeability of enteric epithelium will increase, which is significantly involved in the genesis of IBD. At present, most researches mainly concentrate on the changes of intestinal epithelial cells and the structure and function of intercellular tight junction. Maintenance and repair of enteric epithelial barrier may be the ideal strategy for IBD therapy.

Up-regulation and cytoprotective role of epithelial multidrug resistance-associated protein 1 in inflammatory bowel disease

MRP1 (multidrug resistance-associated protein 1) is well known for its role in providing multidrug resistance to cancer cells. In addition, MRP1 has been associated with both pro- and anti-inflammatory functions in nonmalignant cells. The pro-inflammatory function is evident from the fact that MRP1 is a high affinity transporter for cysteinyl-leukotriene C4 (LTC4), a lipid mediator of inflammation. It remains unexplained, however, why the absence of Mrp1 leads to increased intestinal epithelial damage in mice treated with dextran-sodium sulfate, a model for inflammatory bowel disease (IBD). We found that MRP1 expression is induced in the inflamed intestine of IBD patients, e.g. Crohn disease and ulcerative colitis. Increased MRP1 expression was detected at the basolateral membrane of intestinal epithelial cells. To study a putative role for MRP1 in protecting epithelial cells against inflammatory cues, we manipulated MRP1 levels in human epithelial DLD-1 cells and exposed these cells to cytokines and anti-Fas. Inhibition of MRP1 (by MK571 or RNA interference) resulted in increased cytokine- and anti-Fas-induced apoptosis of DLD-1 cells. Opposite effects, e.g. protection of DLD-1 cells against cytokine- and anti-Fas-induced apoptosis, were observed after recombinant MRP1 overexpression. Inhibition of LTC4 synthesis reduced anti-Fas-induced apoptosis when MRP1 function was blocked, suggesting that LTC4 is the pro-apoptotic compound exported by epithelial MRP1 during inflammation. These data show that MRP1 protects intestinal epithelial cells against inflammation-induced apoptotic cell death and provides a functional role for MRP1 in the inflamed intestinal epithelium of IBD patients.

A novel role for villin in intestinal epithelial cell survival and homeostasis

Apoptosis is a key regulator for the normal turnover of the intestinal mucosa, and abnormalities associated with this function have been linked to inflammatory bowel disease and colorectal cancer. Despite this, little is known about the mechanism(s) mediating intestinal epithelial cell apoptosis. Villin is an actin regulatory protein that is expressed in every cell of the intestinal epithelium as well as in exocrine glands associated with the gastrointestinal tract. In this study we demonstrate for the first time that villin is an epithelial cell-specific anti-apoptotic protein. Absence of villin predisposes mice to dextran sodium sulfate-induced colitis by promoting apoptosis. To better understand the cellular and molecular mechanisms of the anti-apoptotic function of villin, we overexpressed villin in the Madin-Darby canine kidney Tet-Off epithelial cell line to demonstrate that expression of villin protects cells from apoptosis by maintaining mitochondrial integrity thus inhibiting the activation of caspase-9 and caspase-3. Furthermore, we report that the anti-apoptotic response of villin depends on activation of the pro-survival proteins, phosphatidylinositol 3-kinase and phosphorylated Akt. The results of our studies shed new light on the previously unrecognized function of villin in the regulation of apoptosis in the gastrointestinal epithelium.

Insulin-like growth factor binding protein-3 inhibits colitis-induced carcinogenesis

PURPOSE

Chronic inflammation in the setting of inflammatory bowel disease is thought to result in altered epithelial cell growth regulation and ultimately carcinogenesis. This loss in cell growth regulation may be partially caused by a decrease in circulating intact insulin-like growth factor binding protein-3 (IFGB-3) as a result of chronic inflammation. This study evaluates the effect of IFGB-3 on carcinogenesis in the setting of colitis.

METHODS

A previously described animal model for colitis-induced carcinogenesis was used. Colitis was induced in both wild-type and IFGB-3 transgenic CD1 mice with a one-week oral exposure to dextran sodium sulfate (2 percent in drinking water). All mice received a single intraperitoneal administration (10 mg/kg body weight) of a genotoxic colonic carcinogen, azoxymethane. At Week 20, the animals were killed and their colons were excised. The colons were examined by a pathologist under blinded conditions. Criteria assessed included the severity of colitis, number of aberrant crypt foci per mouse colon, incidence of colonic adenomas, and mean size of colonic adenomas.

RESULTS

A total of 20 mice (10 in each group) were included in the study. The severity of colitis was not significantly different between the two groups (mean colitis score wild-type = 13.2; IFGB-3 transgenic = 11; P = not significant). The average number of aberrant crypt foci per colon was significantly lower in the IFGB-3 transgenic mice compared with the wild-type mice (1.5 +/- 1.4 vs. 4.5 +/- 2.7, respectively; P < 0.0001). The number of adenomas per colon was significantly lower in IFGB-3 transgenic group (1.2 +/- 1.8) compared with the wild-type mice (3.7 +/- 2.7; P = 0.005). In addition the average size of adenomas was significantly smaller in IFGB-3 transgenic mice (1.4 +/- 1.3 mm) compared with the wild-type mice (2.6 +/- 2 mm; P = 0.013).

CONCLUSIONS

IFGB-3 significantly reduces the development of colonic tumors and precursor lesions in the setting of induced murine colitis. It is possible that the loss of IFGB-3 as a result of chronic inflammation may be associated with an increased rate of carcinogenesis in the inflammatory bowel disease setting. Although further studies are necessary, in theory, inhibiting the depletion of IFGB-3 or replacement of IFGB-3 may serve as a novel treatment strategy to prevent the development of colitis-induced carcinogenesis.

Immune dysfunction in inflammatory bowel disease

Ulcerative colitis (UC) and Crohn's disease (CD) are idiopathic inflammatory bowel diseases (IBDs) that are characterized by chronic periods of exacerbation and remission. Research into the immunopathogenesis of IBD adds support to the theory that the disease results from a dysfunctional regulation of the immune system that leads to the polarization of intestinal immune cells toward a Th1 (T helper) response. The immunologic factors that mediate alterations in intestinal homeostasis and the development of intestinal mucosal inflammation have been at the forefront of IBD research. Cytokines, which are important regulators of leukocyte trafficking and apoptotic cell death, have emerged as essential immune molecules in the pathogenesis of IBD. In this study, recent advances in the understanding of the dynamism of cytokines and the consequences for mucosal immunity and inflammation in IBD are discussed. Furthermore, this study highlights the potential use of cytokines, anti-cytokine antibodies, and cytokine-related biologic therapies as novel targets for the treatment of IBD.

Substance P mediates antiapoptotic responses in human colonocytes by Akt activation

We examined the hypothesis that substance P (SP) and the neurokinin-1 receptor (NK-1R), both in vitro and in vivo, promote mucosal healing during recovery from colitis by stimulating antiapoptotic pathways in human colonic epithelial cells. For the in vitro experiments, human nontransformed NCM460 colonocytes stably transfected with NK-1R (NCM460-NK-1R cells) were exposed to SP, and cell viability assays, TUNEL assays, and Western blot analyses were used to detect apoptotic and antiapoptotic pathways. SP exposure of NCM460-NK-1R colonocytes stimulated phosphorylation of the antiapoptotic molecule Akt and inhibited tamoxifen-induced cell death and apoptosis evaluated by the cell viability assay and poly(ADP-ribose) polymerase cleavage, respectively. SP-induced phosphorylation of Akt and cleavage of poly(ADP-ribose) polymerase were inhibited by blockade of integrin alphaVbeta3, Jak2, and activation of phosphatidylinositol 3-kinase. For the in vivo experiments, C57BL/6 mice, administered 5% dextran sulfate (DSS) dissolved in tap water for 5 days followed by a 5-day recovery period, were treated with the NK-1R antagonist CJ-12,255 or vehicle. Vehicle-treated mice showed increased colonic Akt phosphorylation and apoptosis compared with mice that received no DSS. In contrast, daily i.p. administration of CJ-12,255 for 5 days post-DSS suppressed Akt activation, exacerbated colitis, and enhanced apoptosis, and pharmacologic inhibition of Akt, either alone or together with CJ-12,255, produced a similar effect. Thus, SP, through NK-1R, possesses antiapoptotic effects in the colonic mucosa by activating Akt, which prevents apoptosis and mediates tissue recovery during colitis.

Apoptosis resistance in ulcerative colitis: high expression of decoy receptors by lamina propria T cells

Intestinal mucosa is constantly exposed to normal environmental antigens. A significant number of intestinal mucosal T cells are being deleted through apoptosis. In contrast, T cells from inflamed mucosa of ulcerative colitis patients did not undergo apoptosis. In this study, we determined whether the apoptosis of normal mucosal T cells was induced by antigen receptor stimulation and further determined pathways that mediated the apoptosis. Freshly isolated lamina propria T cells were stimulated with CD3 mAb and apoptosis was determined by Annexin V staining. Normal mucosal T cells underwent apoptosis upon CD3 mAb stimulation whereas the T cells from inflamed mucosa did not. The apoptosis in normal T cells was blocked by TRAIL-R1:Fc and an inhibiting CD95 antibody. Interestingly, decoy receptor (DcR)1, DcR2, and DcR3 that compete with death receptor (DR)4/5 and CD95 were highly expressed by the T cells from inflamed mucosa, but much lower by T cells from normal mucosa. Our data suggest that normal mucosal T cells are constantly deleted in response to environmental antigens mediated through DR4/5 and CD95 pathways and mucosal T cells from ulcerative colitis resist to undergoing apoptosis due to highly expression of DcR1, DcR2, and DcR3.

Distribution of CD8 T cells and expression of Fas/FasL and Bcl-2/Bax in ulcerative colitis

AIM: To investigate the expression of Fas/FasL and Bcl-2/Bax and distribution of CD8 T cells as well as their correlations in ulcerative colitis (UC).

METHODS: Immunohistochemistry was used to detect the expression of CD8, Bcl-2/Bax and Fas/FasL in intestinal mucosal tissues from UC (n = 60) and normal controls (n = 60).

RESULTS: The positive rate of CD8 was significantly higher in the epithelia of UC tissues than that in the controls (52% vs 78%, P < 0.01), and rate in the active UC was also significantly lower than that in the remissive UC (20% vs 74%, P < 0.01). The positive rate of CD8 in the lamina propria tissues of UC at active stage was markedly higher than that at remissive stage (80% vs 34%, P = 0.0006). The expression of Fas was remarkably higher in the epithelia of UC tissues than that in the controls (62% vs 30%, P < 0.01), and its expression at active UC was also dramatically higher than that at remissive stage (84% vs 45%, P < 0.01). The expression of FasL was significantly increased in the inflammatory cells from the lamina propria of UC tissues as compared with that from normal mucosa (62% vs 7%, P < 0.01), and it was also a significant different between the active and remissive stage (88% vs 43%, P < 0.01). Furthermore, there was a correlation between the expression CD8 and FasL in the inflammatory cells from the lamina propria (χ² = 7.3, P < 0.01). The expression of Bcl-2/Bax was not different between UC and normal mucosa (P > 0.05).

CONCLUSION: The expression of Fas/FasL is up-regulated in UC, but the expression of Bcl-2/Bax is not obviously changed. CD8 T cells play important roles in the development of UC and they are closely related with Fas/FasL system.

Sucralfate prevents the delay of wound repair in intestinal epithelial cells by hydrogen peroxide through NF-kappaB pathway

BACKGROUND

Recent studies have shown that sucralfate (SF) has therapeutic effects on colonic inflammation in ulcerative colitis. The aim of this study was to clarify the function of SF for wound repair in intestinal epithelial cells (IEC).

METHODS

(1) Activation of signal proteins [ERK1/2 mitogen-activated protein kinase (MAPK), IkappaB-alpha] in IEC-6 cells after stimulation with 10(-4) M potassium sucrose octasulfate (SOS), which is the functional element of SF, was assessed by Western blot. (2) Induction of transforming growth factor (TGF)-beta1, TGF-alpha, EGF, and cyclooxygenase-2 (COX-2) mRNA after stimulation of IEC-6 cells with SOS was assessed by reverse transcriptase-polymerase chain reaction. (3) IEC-6 cells were wounded and cultured for 24 h with various concentrations of SOS in the absence or presence of 20 microM H(2)O(2). Epithelial migration or proliferation was assessed by counting migrating cells or bromodeoxyuridine (BrdU)-positive cells across the wound border.

RESULTS

(1) SOS activated IkappaB-alpha, but it did not activate ERK1/2 MAPK. (2) SOS enhanced the expression of COX-2 mRNA, but it did not change the mRNA expression of other growth factors. (3) SOS did not enhance wound repair in IEC-6 cells, but it decreased the number of dead cells (maximum, 74%) (P < 0.01) in a dose-dependent manner and prevented the diminishment of epithelial migration (maximum, 61%) (P < 0.01) and proliferation (maximum, 37%) (P < 0.05) induced by H(2)O(2). These functions of SOS were suppressed by the NF-kappaB and COX-2 inhibitors.

CONCLUSIONS

SOS prevented the delay of wound repair in IEC-6 cells induced by H(2)O(2), probably through induction of COX-2 and an anti-apoptotic mechanism. These effects of SOS might be given through the activation of the NF-kappaB pathway.

Attenuation of apoptosis in enterocytes by blockade of potassium channels

Apoptosis plays an important role in maintaining the balance between proliferation and cell loss in the intestinal epithelium. Apoptosis rates may increase in intestinal pathologies such as inflammatory bowel disease and necrotizing enterocolitis, suggesting pharmacological prevention of apoptosis as a therapy for these conditions. Here, we explore the feasibility of this approach using the rat epithelial cell line IEC-6 as a model. On the basis of the known role of K+ efflux in apoptosis in various cell types, we hypothesized that K+ efflux is essential for apoptosis in enterocytes and that pharmacological blockade of this efflux would inhibit apoptosis. By probing intracellular [K+] with the K+-sensitive fluorescent dye and measuring the efflux of 86Rb+, we found that apoptosis-inducing treatment with the proteasome inhibitor MG-132 leads to a twofold increase in K+ efflux from IEC-6 cells. Blockade of K+ efflux with tetraethylammonium, 4-aminopyridine, stromatoxin, chromanol 293B, and the recently described K+ channel inhibitor 48F10 prevents DNA fragmentation, caspase activation, release of cytochrome c from mitochondria, and loss of mitochondrial membrane potential. Thus K+ efflux occurs early in the apoptotic program and is required for the execution of later events. Apoptotic K+ efflux critically depends on activation of p38 MAPK. These results demonstrate for the first time the requirement of K+ channel-mediated K+ efflux for progression of apoptosis in enterocytes and suggest the use of K+ channel blockers to prevent apoptotic cell loss occurring in intestinal pathologies.

Effects of garlicin on apoptosis in rat model of colitis

AIM

To investigate the effects of garlicin on apoptosis and expression of bcl-2 and bax in lymphocytes in rat model of ulcerative colitis (UC).

METHODS

Healthy adult Sprague-Dawley rats of both sexes, weighing 180+/-30 g, were employed in the present study. The rat model of UC was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) enema. The experimental animals were randomly divided into garlicin treatment group (including high and low concentration), model control group, and normal control group. Rats in garlicin treatment group and model control group received intracolic garlicin daily at doses of 10.0 and 30.0 mg/kg and equal amount of saline respectively 24 h after colitis model was induced by alcohol and TNBS co-enema. Rats in normal control group received neither alcohol nor only TNBS but only saline enema in this study. On the 28th d of the experiment, rats were executed, the expression of bcl-2 and bax protein was determined immunohistochemically and the apoptotic cells were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate fluorescence nick end labeling (TUNEL) method. At the same time, the rat colon mucosal damage index (CMDI) was calculated.

RESULTS

In garlicin treatment group, the positive expression of bcl-2 in lymphocytes decreased and the number of apoptotic cells was more than that in model control group, CMDI was lower than that in model control group. The positive expression of bax in lymphocytes had no significant difference.

CONCLUSION

Garlicin can protect colonic mucosa against damage in rat model of UC induced by TNBS enema.

Insulin-like growth factor binding protein 3 in inflammatory bowel disease

Epithelial cell growth regulation has been reported to be altered in inflammatory bowel disease (IBD) patients. The cell growth regulatory factor, insulin-like growth factor binding protein 3 (IGFBP-3), may be partly responsible for this phenomenon. So far, IGFBP-3 levels have been assessed as values of total protein, which is a sum of bioactive intact 43- to 45-kDa protein and its inactive proteolytic cleavage fragments. We aimed to assess the levels of intact IGFBP-3 and its cleaving protease MMP-9 in IBD. Patients with IBD and controls were included. Total plasma IGFBP-3 concentration was measured in ELISA. Western blot analysis, which distinguishes between intact and cleaved IGFBP-3, was performed in order to determine the ratio of intact to total protein; this ratio was used to calculate the concentration of intact IGFBP-3. The profile of plasma proteases was evaluated in zymography and MMP-9 levels were determined in ELISA. The concentration of intact IGFBP-3 was significantly decreased in patients with moderate to severe IBD activity compared to those in remission or controls. Of note, a dramatic depletion of intact IGFBP-3 was found in 7.4% of patients with IBD. Zymography revealed that the dominant gelatinase was the pro-form of MMP-9. However, no differences in MMP-9 levels were noted between those with active disease and controls. The level of intact IGFBP-3 is decreased in IBD patients with moderate to severe disease activity. This decrease may be linked to altered IGFBP-3 production or to increased cleavage by proteases other than MMP-9.

Anti-CD3 induces bi-phasic apoptosis in murine intestinal epithelial cells: possible involvement of the Fas/Fas ligand system in different T cell compartments

Recent studies have suggested that Fas-mediated apoptosis is involved in the pathogenesis of intestinal injury. In this study, we determined the role of Fas/Fas ligand (FasL) interactions in different T cell compartments using a murine model of small intestinal injury. An intraperitoneal injection of 145-2C11 (anti-CD3) antibody into C3H/HeN, BALB/c and MRL mice induced mucosal flattening and rapid, bi-phasic intestinal epithelial cell (IEC) apoptosis, which was detected by conventional light and electron microscopy and by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling. In the first, early phase, villous apoptosis was observed up to 4 h after injection, and in the second, later phase, apoptotic crypt cells gradually accumulated for up to 24 h. The early and later phases of apoptosis were reduced in lpr/lpr and nude mice compared with those in control strains. In addition, the kinetics of Fas-mediated killer activity induced by the antibody injection were different between intestinal intraepithelial lymphocytes (IEL) and splenocytes (SPL) and seemed to correlate with the bi-phasic occurrence of the apoptosis. Finally, the transfer of intestinal IEL from euthymic to nude mice induced both phases of apoptosis, whereas SPL induced the second phase's crypt apoptosis only by the antibody injection. Together, these results suggest the involvement of Fas-mediated killer activity of thymus-derived T cells in different compartments. Namely, T cell populations in different compartments are differentially involved in the induction of IEC apoptosis and contribute to the complex pathogenesis of immune-mediated intestinal injury in which Fas/FasL interactions may play a critical role.

Low soluble Fas (sFas) and sFas ligand (sFasL) content in breast milk after preterm as opposed to term delivery

AIM

Various mechanisms of innate immunity and gastrointestinal integrity are potentially affected by soluble Fas (sFas) and sFas ligand (sFasL). Assuming that sFas and sFasL in milk reflect cellular events during lactogenesis, we aimed to assess the impact of premature parturition and duration of lactation on the concentrations of sFas and sFasL in human milk.

PATIENTS AND METHODS

The content of the soluble form of the cell surface receptor Fas (sFas) and its natural ligand (sFasL) was measured in human breast milk of 44 healthy mothers after preterm (<35 wk, n=21) and term (>37 wk, n=23) delivery. Milk was furthermore classified as immature breast milk (days 4-7 of lactation) or mature breast milk (days 35-45 of lactation). Breast milk (2-3 ml) was sampled 5 min after the start of breastfeeding by manual expression or milk pump, and stored at -20 degrees C until analysis by an ELISA.

RESULTS

sFas and sFasL concentrations were lower in immature milk after preterm compared to term delivery (sFas: 1.71; 1.38-2.47 ng/ml vs 3.03; 2.02-4.30 ng/ml, p < 0.001; sFasL: 0.13; 0.07-0.21 ng/ml vs 0.29; 0.15-0.60 ng/ml, p < 0.001 [median +/- interquartile range]). Mature milk samples, taken 1 mo later from both gestational groups, did not differ in sFas/sFasL content. Soluble Fas was positively correlated with sFasL in the same sample of immature (p < 0.001) and mature human milk (p < 0.05). A positive correlation was found between sFas and sFasL in immature and mature milk samples of the same mother (p < 0.01). The body mass index of the mothers and duration of pregnancy were positively correlated with the sFas and sFasL content in immature milk (p < 0.05 and p < 0.01, respectively) but not in mature milk.

CONCLUSION

Preterm newborn infants fed with breast milk have a lower intake of sFas and sFasL compared to term neonates. Our results demonstrate that preterm delivery affects breast milk composition.

Association of Fas-670 gene polymorphism with inflammatory bowel disease in Chinese patients

AIM: Recent studies suggest that Fas-mediated apoptosis is involved in the pathogenesis of inflammatory bowel disease (IBD). It has been hypothesized that either increased apoptosis of intestinal epithelium or decreased apoptosis of lamina propria lymphocytes may induce inflammation of gut. The aim of this study was to determine whether the Fas gene promoter polymorphism at position-670 was associated with IBD in Chinese patients.

METHODS: Fifty unrelated Chinese patients with IBD (38 patients with ulcerative colitis and 12 with Crohn’s disease) and 124 healthy controls were genotyped for the Fas-670 polymorphism by PCR-restriction fragment length polymorphism method. The PCR product was digested by Mva I restriction enzyme.

RESULTS: Distribution of the Fas-670 gene polymorphism was 33% for the AA genotype, 52% for the AG genotype and 15% for the GG genotype in 124 healthy subjects. In patients with IBD, 30% was for the AA genotype, 42% for the AG genotype and 28% for the GG genotype respectively. However, there was no significant difference in the genotype (P = 0.1498), allele frequencies (P = 0.3198) and carriage frequencies (P = 0.4133) between healthy controls and IBD patients. Furthermore, we did not find any difference between the left-sided colitis and total colitis (P = 0.8242).

CONCLUSION: Fas-670 polymorphism is not associated with IBD in Chinese patients.

Activator protein-1 signalling pathway and apoptosis are modulated by poly(ADP-ribose) polymerase-1 in experimental colitis

Poly(ADP-ribose) polymerase-1 (PARP-1) is activated in response to DNA injury in the nucleus of eukaryotic cells and has been implicated in intestinal barrier dysfunction during inflammatory bowel diseases. In this study we investigated whether PARP-1 may regulate the inflammatory response of experimental colitis at the level of signal transduction mechanisms. Mice genetically deficient of PARP-1 (PARP-1(-/-)) and wild-type littermates were subjected to rectal instillation of trinitrobenzene sulphonic acid (TNBS). Signs of inflammation were monitored for 14 days. In wild-type mice, TNBS treatment resulted in colonic ulceration and marked apoptosis, which was associated with decreased colon content of the antiapoptotic protein Bcl-2, whereas the proapoptotic Bax was unchanged. Elevated levels of plasma nitrate/nitrite, metabolites of nitric oxide (NO), were also found. These inflammatory events were associated with activation of c-Jun-NH(2) terminal kinase (JNK), phosphorylation of c-Jun and activation of the nuclear transcription factor activator protein-1 (AP-1) in the colon. In contrast, PARP-1(-/-) mice exhibited a significant reduction of colon damage and apoptosis, which was associated with increased colonic expression of Bcl-2 and lower levels of plasma nitrate/nitrite when compared to wild-type mice. Amelioration of colon damage was associated with a significant reduction of the activation of JNK and reduction of the DNA binding of AP-1. The data indicate that PARP-1 exerts a pathological role in colitis possibly by regulating the early stress-related transcriptional response through a positive modulation of the AP-1 and JNK pathways.

Expression of TNF-related apoptosis-inducing ligand (TRAIL) in megakaryocytes and platelets

OBJECTIVE

Platelets are known to play an important role in hemostasis, thrombosis, wound healing, and inflammation. Platelet-induced modulation of inflammation and adaptive immune responses are mediated in part through tumor necrosis factor (TNF) family member ligands, including CD154, Fas ligand, and TNFalpha, that are expressed upon platelet activation. The present study investigated whether platelets and megakaryocytes also express TNF-related apoptosis-inducing ligand (TRAIL), another pro-apoptotic member of the TNF superfamily.

MATERIALS AND METHODS

Immunoprecipitation, enzyme-linked immunosorbent assay, and flow cytometry were used to assess TRAIL protein expression on isolated platelets, in vitro-derived megakaryocytes and premegakaryocyte cell lines. Reverse-transcription polymerase chain reaction and transient transfection of TRAIL promoter/reporter constructs were used to elucidate mechanisms of TRAIL regulation during megakaryocyte differentiation. TRAIL-dependent cytotoxicity assays were performed to determine if platelet-derived TRAIL induces apoptosis of TRAIL sensitive target cells.

RESULTS

Activated platelets expressed both membrane-bound and soluble TRAIL. TRAIL was also expressed by megakaryocytes, and in vitro studies showed that TRAIL expression was induced upon megakaryocyte differentiation. TRAIL expression was mediated by increased transcriptional activity of the TRAIL promoter, suggesting lineage-specific regulation of TRAIL during megakaryocyte differentiation. Abundant detergent-extractable, full-length TRAIL protein was observed in the lysates of platelets and megakaryocytes, but only low concentrations of TRAIL were released by nondetergent extraction methods.

CONCLUSION

The data reported herein show that platelets express TRAIL that is synthesized by megakaryocytes and was expressed by activated platelets. While these data expand the spectrum of TNF family proteins expressed in platelets, the function of platelet-derived TRAIL is not known.

A primary dysregulation in the immunoregulatory role of the intestinal mucosal epithelial cell in inflammatory bowel disease pathogenesis? Biology of inflammatory response as tissue pattern entities in Crohn's versus ulcerative colitis

Within a framework of dual involvement of mucosa and submucosa on the one hand, and of the muscularis propria of the bowel wall on the other, it might be valid to consider involvement of the vascular supply as the essential means in itself of not only causing the morphologic lesions in inflammatory bowel disease, but also especially in accounting for persisting patterns of inflammatory response both in ulcerative colitis and in Crohn's disease. Inflammatory bowel disease as a group constitutes a spectrum of biologic and pathobiologic manifestations in terms not only of inflammatory involvement of the bowel wall but also in terms of how the bowel in its turn deals with inflammation as a pathologic lesion in its own right. Parameters of inflammatory bowel activity transcend simple concepts of etiology and pathogenesis as applicable to category disorders such as infections or bowel ischemia. Indeed, the strictly characterized initiation of the inflammatory bowel response as a function of defective regulation of the antigenicity of the luminal contents on the one hand, and on interactions between nitric oxide and free oxygen radicals on the other, might help determine a persistence of tissue damage in inflammatory bowel disease that is either relapsing/remitting or chronic in progression. In a final analysis, perhaps, there might be involved a single central form of pathway induction of dysregulated immune reactivity arising from an early disturbance in activation patterns as induced by the onset of luminal antigenicity at an early or specific-stage, further characterized perhaps by specific forms of intestinal epithelial defects of the bowel mucosa in patients subsequently developing inflammatory bowel disease. Specific genetic markers for disease susceptibility and for therapeutic responsiveness are particularly of interest. The Nucleotide binding oligomerization Domain 2 (NOD2) would recognize microbial lipopolysaccharide or else mark systemic responses to pathogens that are pathogenic to evolving inflammatory bowel disease.

Mechanisms of acupuncture and moxibustion in regulation of epithelial cell apoptosis in rat ulcerative colitis

AIM: To investigate the effect of acupuncture and moxibustion on epithelial cell apoptosis and expression of Bcl-2, Bax, fas and FasL proteins in rat ulcerative colitis.

METHODS: A rat model of ulcerative colitis was estabelished by immunological methods and local stimulation. All rats were randomly divided into model control group (MC), electro-acupuncture group (EA), herbs-partition moxibustion group (HPM). Normal rats were used as normal control group (NC). Epithelial cell apoptosis and expression of Bcl-2, Bax, fas and FasL proteins were detected by TUNEL and immunohistochemiscal method respectively.

RESULTS: The number of epithelial cell apoptosis in MC was significantly higher than that in NC, and was markedly decreased after the treatment with herbs-partition moxibustion or electro-acupuncture. The expression of Bcl-2, Bax, fas and FasL in colonic epithelial cells in MC was higher than that in NC, and was markedly down- regulated by herbs-partition moxibustion or electro-acupuncture treatment.

CONCLUSION: The pathogenesis of ulcerative colitis in rats involves abnormality of apoptosis. Acupuncture and moxibustion can regulate the expression of Bcl-2, Bax, fas and FasL proteins and inhibit the apoptosis of epithelial cells of ulcerative colitis in rats by Bcl-2/Bax, fas/FasL pathways.

The expression and role of Fas ligand in intestinal inflammation

Fas ligand (FasL) is involved in the pathogenesis of inflammatory diseases and immune privilege. We examined the expression of FasL in the enteric nervous system (ENS) in murine colitis and guinea-pig ileitis. We studied FasL immunoreactivity, functional integrity of the ENS, severity of colitis, and distribution of neutrophils in wild type and B6/gld mice that lack functional FasL. In ileitis, the distribution of FasL, CD4+ and CD8+ T cells was examined. FasL expression was increased in the ENS of wild type mice with colitis, but decreased labelling of nerve fibres was noted in B6/gld mice. Neutrophils were more abundant and widely distributed in B6/gld mice. Colitis was more severe and persistent in B6/gld mice 7 days after induction. Functional parameters of intestinal secretion and motility in B6/gld mice were the same as controls. In ileitis, FasL expression was increased in the guinea-pig ENS and returned to control levels following the resolution of inflammation. While T cells were not present in the ENS of controls, they were observed during inflammation, but were excluded from ganglia. The number of enteric neurons was unchanged over the course of inflammation. The expression of FasL is altered in intestinal inflammation and contributes to its resolution in experimental colitis.

Enterocyte apoptosis after enterectomy in mice is activated independent of the extrinsic death receptor pathway

Intestinal adaptation following small bowel resection (SBR) is associated with greater rates of enterocyte apoptosis by unknown mechanism(s). Because postresection adaptation is associated with increased translocation of luminal bacteria, we sought to characterize the role for the extrinsic, death receptor pathway for the activation of enterocyte apoptosis after massive SBR. We first performed SBR or sham operations in mice, and the temporal expression of caspases 8, 9, and 3, death receptors tumor necrosis factor receptor-1 (TNFR1) and Fas and corresponding ligands (TNF and Fas ligand) was determined in the remnant intestine at various postoperative time points. Ileal TNFR1 and Fas expression were then measured after SBR in the setting of increased (waved-2 mice) or decreased (exogenous EGF administration) apoptosis. Finally, intestinal adaptation and apoptosis were recorded in the remnant ileum after SBR in TNFR1-null and Fas-null mice. The expression of death receptor family proteins and caspases demonstrated only modest changes after SBR and did not correlate with the histological appearance of apoptosis. In the setting of accelerated apoptosis, TNFR1 and Fas expression were paradoxically decreased. Apoptotic and adaptive responses were preserved in both TNFR1-null and Fas-null mice. These results suggest that the mechanism for increased enterocyte apoptosis following massive SBR does not appear to involve the extrinsic, death receptor-mediated pathway.

Effects of allitridi on lymphocyte apoptosis and its regulatory gene expression in rat ulcerative colitis

AIM

To investigate the effects of Allitridi on lymphocyte apoptosis and its regulatory gene expression in rat ulcerative colitis.

METHODS

Rat colitis model was induced by 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). The apoptotic cells were visualized by TUNEL. Bcl-2 and Bax protein expression in colon tissue was examined by immunohistochemistry. Biochemistry was used to detect the nitrogen monoxide (NO) activity in the mucosa, At the same time, the macroscopical and histological changes of the colon were evaluated.

RESULTS

In TNBS group, the content of nitrogen monoxide, the positive cell quantity of expression of Bcl-2 and the apoptotic cell quantity were higher than those in both normal group and TNBS+Alt group (P<0.01), but Bax positive cell quantity was lower than that in normal group (P<0.01).

CONCLUSION

Allitridi has protective effects on ulcerative colitis of rat by promoting apoptosis of lymphocytes in lamina propria and cleaning NO free radical.