Fas/Fas ligand expression and characteristics of primed CD45RO+ T cells in the inflamed mucosa of ulcerative colitis

Chorioamniotic membrane senescence: a signal for parturition?

OBJECTIVE

Senescence is an important biological phenomenon involved in both physiologic and pathologic processes. We propose that chorioamniotic membrane senescence is a mechanism associated with human parturition. The present study was conducted to explore the association between senescence and normal term parturition by examining the morphologic and biochemical evidences in chorioamniotic membranes.

STUDY DESIGN

Chorioamniotic membranes were collected from normal term deliveries; group 1: term labor and group 2: term, not in labor. Senescence-related morphologic changes were determined by transmission electron microscopy and biochemical changes were studied by senescence-associated (SA) β-galactosidase staining. Amniotic fluid samples collected from both term labor and term not in labor were analyzed for 14 SA secretory phenotype (SASP) markers.

RESULTS

Morphologic evidence of cellular senescence (enlarged cells and organelles) and a higher number of SA β-galactosidase-stained amnion and chorion cells were observed in chorioamniotic membranes obtained from women in labor at term, when compared to term not in labor. The concentration of proinflammatory SASP markers (granulocyte macrophage colony-stimulating factor, interleukin-6 and -8) was significantly higher in the amniotic fluid of women in labor at term than women not in labor. In contrast, SASP factors that protect against cell death (eotaxin-1, soluble Fas ligand, osteoprotegerin, and intercellular adhesion molecule-1) were significantly lower in the amniotic fluid samples from term labor.

CONCLUSION

Morphologic and biochemical features of senescence were more frequent in chorioamniotic membranes from women who experienced term labor. Senescence of chorioamniotic membranes were also associated with amniotic fluid SASP markers.

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.

Effect of treatment with safflower solution on expression of VEGF and bFGF in ulcerative colitis in rats

AIM: To evaluate the therapeutic effect of safflower solution on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced ulcerative colitis in rats and to explore the underlying mechanisms by observing the expression of vascular endothelial growth factor (VEGF) and basal fibroblast growth factor (bFGF).

METHODS: Thirty Wistar rats were randomly divided into normal control group, model group and safflower group. Ulcerative colitis was induced in the safflower group and model group with TNBS by enema. Rats of the safflower group were intraperitoneally injected with safflower solution. After ten days, all rats were killed. Disease activity index (DAI), colon macroscopic damage score (CMDS) and histological damage score were evaluated. Pathological changes in the colonic mucosa were examined by HE staining. The expression of VEGF and bFGF in the colonic mucosa was detected by real time-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC).

RESULTS: Compared to normal controls, the DAI, CMDS and histological damage scores in model rats were significantly increased (all P < 0.01). Compared to the model group, the above parameters were significantly improved in the safflower group (all P < 0.05). Compared to normal controls, the expression levels of VEGF and bFGF in model rats were increased significantly (all P < 0.01). Treatment with safflower solution significantly decreased the expression levels of VEGF mRNA and protein in ulcerative colitis (both P < 0.05).

CONCLUSION: Treatment with safflower solution could reduce inflammatory injury in a rat model of ulcerative colitis possibly by reducing the expression of VEGF and inhibiting pathologic angiogenesis in the colonic mucosa.

Butyrate suppresses colonic inflammation through HDAC1-dependent Fas upregulation and Fas-mediated apoptosis of T cells

Butyrate, an intestinal microbiota metabolite of dietary fiber, has been shown to exhibit protective effects toward inflammatory diseases such as ulcerative colitis (UC) and inflammation-mediated colorectal cancer. Recent studies have shown that chronic IFN-γ signaling plays an essential role in inflammation-mediated colorectal cancer development in vivo, whereas genome-wide association studies have linked human UC risk loci to IFNG, the gene that encodes IFN-γ. However, the molecular mechanisms underlying the butyrate-IFN-γ-colonic inflammation axis are not well defined. Here we showed that colonic mucosa from patients with UC exhibit increased signal transducer and activator of transcription 1 (STAT1) activation, and this STAT1 hyperactivation is correlated with increased T cell infiltration. Butyrate treatment-induced apoptosis of wild-type T cells but not Fas-deficient (Fas(lpr)) or FasL-deficient (Fas(gld)) T cells, revealing a potential role of Fas-mediated apoptosis of T cells as a mechanism of butyrate function. Histone deacetylase 1 (HDAC1) was found to bind to the Fas promoter in T cells, and butyrate inhibits HDAC1 activity to induce Fas promoter hyperacetylation and Fas upregulation in T cells. Knocking down gpr109a or slc5a8, the genes that encode for receptor and transporter of butyrate, respectively, resulted in altered expression of genes related to multiple inflammatory signaling pathways, including inducible nitric oxide synthase (iNOS), in mouse colonic epithelial cells in vivo. Butyrate effectively inhibited IFN-γ-induced STAT1 activation, resulting in inhibition of iNOS upregulation in human colon epithelial and carcinoma cells in vitro. Our data thus suggest that butyrate delivers a double-hit: induction of T cell apoptosis to eliminate the source of inflammation and suppression of IFN-γ-mediated inflammation in colonic epithelial cells, to suppress colonic inflammation.

Diammonium glycyrrhizinate up-regulates the expression of Foxp3 mRNA in rats with ulcerative colitis

AIM: To evaluate the protective effect of diammonium glycyrrhizinate (DG) against ulcerative colitis in rats and to investigate potential mechanisms involved.

METHODS: Thirty Sprague-Dawley (SD) rats were equally randomized into normal control group, model group and DG group. Ulcerative colitis was induced in the DG group and model group by rectal administration of trinitrobenzene sulphonic acid (TNBS). Disease activity index (DAI) and histological damage were evaluated, and the expression of forkhead box P3 (Foxp3) mRNA in peripheral blood mononuclear cells (PBMCs) was detected by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: Both DAI and histological damage score were significantly higher in the model group than in the normal control group (DAI: 7.1 ± 0.2 vs 0.3 ± 0.6, P < 0.05; histological damage score: 6.7 ± 0.5 vs 0.9 ± 0.2, P < 0.05). Compared with the model group, DAI and histological damage score were significantly improved in the DG group (DAI: 3.1 ± 0.6 vs 7.1 ± 0.2, P < 0.05; histological damage score: 3.3 ± 0.4 vs 6.7 ± 0.5, P < 0.05). Compared with the normal control group, the expression of Foxp3 mRNA was down-regulated in PBMCs in the model group (0.51 ± 0.34 vs 1.09 ± 0.38, P < 0.05). DG treatment significantly up-regulated the expression of Foxp3 mRNA in PBMCs (0.92 ± 0.53 vs 0.51 ± 0.34, P < 0.05).

CONCLUSION: DG can ameliorate colonic inflammation in rats with ulcerative colitis possibly by increasing the expression of Foxp3 mRNA in PBMCs.

Apoptosis in bowel mucosal tissues of patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) is non-specific inflammatory disease in intestinal tract, and its etiology and pathogenesis are still unclear, which are probably associated with environmental factors, genetic factors and immunological factors. Studies have demonstrated that cell apoptosis plays an important role in the development of IBD, characterized by increased intestinal epithelial cell apoptosis, apoptosis resistance of intestinal lamina propria lymphocytes and apoptosis delay of polymorphonuclear neutrophils. Further studies have indicated that activation of Fas/FasL signaling transduction, Bcl-2 and Bax pathways is involved in cell apoptosis. This paper highlights the potential role of mucosal cell apoptosis in the pathogenesis and treatment of IBD.

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.

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.

Leukocytapheresis is effective in inducing but not in maintaining remission in ulcerative colitis

GOALS AND BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by dense infiltration of lymphocytes, plasma cells, neutrophils, and monocyte-macrophages into the colonic mucosa. Leukocytapheresis is a procedure for selectively removing white blood cells from withdrawn blood. It is used for the treatment of several autoimmune diseases. This study was performed to evaluate the effectiveness of leukocytapheresis for inducing and maintaining remission in corticosteroid-resistant UC, as compared with corticosteroid-responsive UC.

STUDY

Forty-five patients with active UC who were treated with a dose of 1 mg/kg per day or more of prednisolone given systemically for at least 2 weeks were evaluated. Twenty patients (6 males, 14 females) in whom improvement was induced only by high doses of prednisolone were allocated as the corticosteroid-responsive group. The other 25 patients (11 males, 14 females) who did not respond to the above-mentioned dose of prednisolone therapy were allocated as the corticosteroid-resistant group and received leukocytapheresis therapy once a week for 5 weeks. Of patients who had a remission, the corticosteroid-responsive group continued to have the conventional therapy and the corticosteroid-resistant group were given leukocytapheresis once every 4 weeks for at least 2 years as maintenance therapy.

RESULTS

Remission was induced by 5 weeks of leukocytapheresis in 23 of the 25 (92%) patients with corticosteroid-resistant active UC. The number of days required to achieve remission of UC was fewer in patients who received leukocytapheresis than in those who did not. Follow-up study of the patients who had remission showed similar relapse rates at 2 years in the patients who received leukocytapheresis and those given high doses of prednisolone alone.

CONCLUSIONS

Leukocytapheresis is an effective treatment of acute corticosteroid-resistant UC but does not prevent the recurrence of UC.

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-trinitr-obenzene 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 28^th 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.

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.

Inflammatory bowel disease: dysfunction of GALT and gut bacterial flora (I)

Gut-associated lymphoid tissue (GALT) is the largest lymphoid organ in the body. This is not surprising considering the huge load of antigens (Ags) from food and commensal bacteria with which it interacts on a daily basis. Gut-associated lymphoid tissue has to recognise and allow the transfer of beneficial Ags whilst concurrently dealing with and successfully removing putative and overtly harmful Ags. This distinctive biological feature of GALT is believed to be crucial to good health. Deregulation or dysfunction of GALT is thought to predispose to inflammatory bowel diseases (IBD) such as ulcerative colitis and Crohn's disease. The exact mechanism(s) underlying the pathogenesis of IBD is (are) poorly understood and the immunological defects in GALT are poorly documented. Advances in immunology have highlighted the importance of dendritic cells (DCs), which are the key Ag presenting cells in tissues and lymphoid compartments. Their crucial role in GALT, in health and disease is discussed in this review. Interaction of DCs with T cells in the gut produces a subset of T lymphocytes, which have immunosuppressive function. Inappropriate Ag uptake and presentation to naïve T cells in mesenteric lymph nodes may lead to T cell tolerance in GALT. These various complex factors in the gut are discussed and their possible relevance to IBD evaluated.

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.

Higher proliferative capacity of T lymphocytes from patients with Crohn disease than from ulcerative colitis is disclosed by use of Herpesvirus saimiri-transformed T-cell lines

BACKGROUND

T lymphocytes play a crucial role in the pathogenesis of inflammatory bowel disease. Achieving stable T-cell lines, rather than continuous bleeding of patients, is desirable in order to dissect their implication in the disease.

METHODS

Long-lasting T-cell lines from patients with Crohn disease and ulcerative colitis and from healthy volunteers have been obtained by transformation of T lymphocytes using the lymphotropic Herpesvirus saimiri. Lines were subjected to phenotypic and functional analyses, and the results compared with freshly isolated peripheral blood mononuclear cells.

RESULTS

Fresh cells revealed only minor differences between patients and controls, with regard to phenotype and proliferative capacity. In contrast, the use of T-cell lines showed that cells from Crohn disease patients, but not ulcerative colitis patients, over-responded to several membrane or cytoplasmic stimuli when compared to control T-cell lines. Thus, higher responses were found when stimulated with alphaCD3 and IL2, alphaCD3 and alphaCD28, IL2 alone, phorbol esters (PMA) and alphaCD3 and, finally, PMA and alphaCD2 (P < 0.05 in all instances). Further, lines from patients with Crohn disease responded more vigorously to alphaCD3 and alphaCD28 or alphaCD3 and PMA when compared to ulcerative colitis (P < 0.05 in both instances).

CONCLUSIONS

The data obtained with these lines suggest that T cells from patients with Crohn disease differ in vivo in their proliferative capacity, as compared with those from ulcerative colitis patients, a finding that may reflect the clear Th-1 phenotype found in the former and absent in the latter.

Effect of Lichangsifang on cellular apoptosis and expression of the related regulatory genes in rats with ulcerative colitis

AIM: To study the immunoregulatory and treatment effects of Lichangsifang (LCSF) on apoptosis and protein expression of Bcl-2, Bax and Fas genes in rats with ulcerative colitis (UC), and to analyze its underlying mechanism.

METHODS: In the experiment, ninty-eight SD rats were randomly divided into seven groups: normal control group, pathologic control group, solfasalazine (SASP) group, Wumeiwan (WMW) group, Baitouwengtang (BTWT) group, Senglingbaishusan (SLSS) group, and Tongxieyaofang (TXYF) group. Every group had fourteen rats (seven male and seven female). Except the normal control group, A UC animal model was made with DNCB and acetic acid the other six groups, which were treated by distilled water, SASP, TXYF, WMW, BTWT, SLBSS and TXYF, respectively. After these treatment, the changes of apoptosis and protein expression of Bcl-2, Bax and Fas gene in UC were observed.

RESULTS: The level of apoptotic index (AI) in pathologic group was significantly higher than that in normal group (P < 0.01 t = 3.835). After these treatment, the degree of the AI decreased in each experimental group, as compared with the pathologic group (P < 0.05, q = 4.210 vs TXYF group or P < 0.01, q = 5.973 vs WMW group, q = 5.986 vs BTWT group, q = 5.905 vs SASP group, q = 5.889 vs SASP group). The apoptosis of normal control group (Bcl-2/Ba x> 1) togther with LCSF and SASP groups was less (P < 0.01 q = 3.972 vs WMW group, q = 3.523 vs BTWT group, q = 3.694 vs SLBSS group, q = 3.549 vs TXYF group, q = 3.727 vs SASP group). There was remarkable difference in the degree of Bcl-2 and Bax expression between pathologic group (Bcl-2/Bax < 1) and normal group (P < 0.01, F = 2.96). The degree of apoptosis in pathologic group was significantly higher than that in normal group (P < 0.05,t = 3.956 vs pathologic group). There was no remarkable difference between LCSF and SASP groups in the protein expression on Bcl-2, Bax and Fas genes in UC (P > 0.05, F = 3.19, 3.05, and 2.97).

CONCLUSION: This model induced with DNCB and acetic acid is successful. It is obvious that the apoptosis and protein expression of Bcl-2, Bax and Fas genes play an important role in the pathogenesis of UC. All the treatment groups (including SASP group) have rather better curative effects on UC by reducing apoptosis and adjusting cell immunity.

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.

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.

CD95 (Fas/APO-1)/CD95L in the gastrointestinal tract: fictions and facts

CD95 is a member of the tumor necrosis factor receptor family. It is constitutively expressed on the basolateral membrane of intestinal epithelial cells (IEC) and induces apoptosis when cross-linked by its natural ligand, CD95L. The significance of providing such a death-inducing mechanism in IEC is not yet clear. In recent years a multitude of studies have been published addressing the question of where and under which conditions CD95L is produced in the gut in the normal and neoplastic situation. Although some of these studies have considerably influenced our view on the role of the CD95/CD95L system, it appears necessary to critically review published data which are in part confusing and contradictory. To date compelling evidence of CD95L expression in untransformed IEC is lacking, and involvement of the CD95/CD95L system in the physiological epithelial cell turnover appears unlikely. Whereas CD95L is overexpressed in T-cells under inflammatory conditions, its significance for mucosal damage in inflammatory bowel diseases is obscured by possible redundancies in cell death mechanisms. Finally, recent data indicate that the intriguing CD95L counterattack concept in gastrointestinal tract cancer needs to be revised.

Increase in colorectal epithelial apoptotic cells in patients with ulcerative colitis ultimately requiring surgery

BACKGROUND AND AIMS

Up to one-third of patients with ulcerative colitis (UC) need to undergo surgery, but the factors that exacerbate inflammation remain unclear. The authors hypothesize that excessive apoptosis reported in active UC may disrupt epithelial defenses and exacerbate the disease. The aim of the present study was to clarify whether apoptotic epithelial cells and histiocytes engulfing them increased in patients with active UC who ultimately require surgery (UC-S) rather than those receiving medication alone (UC-M).

METHODS

The study included 29 patients with UC-S, 35 with UC-M, 18 with infectious colitis, and 16 healthy controls. Apoptotic cells were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). Using biopsy specimens taken from the most severely inflamed rectosigmoid mucosa as determined endoscopically, the apoptotic index (apoptotic cells/epithelial cells,%) and density (per mm2) of lamina propria histiocytes positive for CD68 were then evaluated. Statistical differences were tested with the Mann-Whitney U-test.

RESULTS

The apoptotic indices in UC-M patients were significantly higher than those in controls (P < 0.05) but almost equal to those in infectious colitis patients. In the upper and lower halves of the mucosa, both apoptotic indices and histiocyte densities were significantly higher for UC-S than in UC-M (P < 0.01). Ratios of the mean apoptotic index for UC-S to that for UC-M exceeded 3.4, while ratios of the mean histiocyte density were limited to approximately 1.6.

CONCLUSIONS

The results suggest that epithelial apoptosis is a non-specific phenomenon and that an increased number of apoptotic cells exceeding histiocyte phagocytic capacity may play a part in the disruption of epithelial defenses and further accelerate mucosal inflammation.

Gliotoxin, an inhibitor of nuclear factor-kappa B, attenuates peptidoglycan-polysaccharide-induced colitis in rats

Gliotoxin is a fungal metabolite that has immunosuppressive properties. First, we determined if gliotoxin could inhibit bacterial peptidoglycan-polysaccharide-stimulated tumor necrosis factor-alpha production, as well as nuclear factor-kappa B (NF-kappaB), in a rat macrophage (NR8383) cell line. Next, the apoptosis-inducing potential of gliotoxin was also evaluated in this cell line. Finally, we evaluated whether gliotoxin could reduce peptidoglycan-polysaccharide-induced colitis in rats. Gliotoxin (2 mg/kg/day) was dosed from day 14 after the initial intramural colonic injection of peptidoglycan-polysaccharide until day 21. A gross colonic injury score, myeloperoxidase activity, and cytokine levels were all evaluated on day 21. Gliotoxin dose dependently inhibited cytokine production, as well as NF-kappaB, and also induced apoptosis in the NR8383 cell line. On day 21, gliotoxin significantly reduced gross colonic injury (adhesions, nodules, mucosal lesions) in rats. Gliotoxin-treated rats also had partially normalized biochemical indices of colitis, such as colonic cytokine levels. The colonic level of NF-kappaB was also partially normalized in gliotoxin treated rats. Gliotoxin also exhibited an antiarthritis effect in peptidoglycan-polysaccharide-treated rats. In summary, gliotoxin effectively attenuated the chronic reactivation phase of peptidoglycan-polysaccharide-induced colitis. This anticolitis effect may be related to the inhibition of NF-kappaB in Lewis rats.