Therapeutic and prophylactic thalidomide in TNBS-induced colitis: Synergistic effects on TNF-α, IL-12 and VEGF production

Application of Drug Repurposing Approach for Therapeutic Intervention of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), represented by Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disorder of the gastrointestinal tract (GIT) characterized by chronic relapsing intestinal inflammation, abdominal pain, cramping, loss of appetite, fatigue, diarrhoea, and weight loss. Although the etiology of IBD remains unclear, it is believed to be an interaction between genes, and environmental factors, such as an imbalance of the intestinal microbiota, changing food habits, an ultra-hygiene environment, and an inappropriate immune system. The development of novel effective therapies is stymied by a lack of understanding of the aetiology of IBD. The current therapy involves the use of aminosalicylates, immunosuppressants, and corticosteroids that can effectively manage symptoms, induce and sustain remission, prevent complications, modify the course of the disease, provide diverse treatment options, showcase advancements in biologic therapies, and enhance the overall quality of life. However, the efficacy of current therapy is overshadowed by a plethora of adverse effects, such as loss of weight, mood swings, skin issues, loss of bone density, higher vulnerability to infections, and elevated blood pressure. Biologicals, like anti-tumour necrosis factor agents, can stimulate an autoimmune response in certain individuals that may diminish the effectiveness of the medication over time, necessitating a switch to alternative treatments. The response of IBD patients to current drug therapy is quite varied, which can lead to disease flares that underlines the urgent need to explore alternative treatment option to address the unmet need of developing new treatment strategies for IBD with high efficacy and fewer adverse effects. Drug repurposing is a novel strategy where existing drugs that have already been validated safe in patients for the management of certain diseases are redeployed to treat other, unindicated diseases. The present narrative review focuses on potential drug candidates that could be repurposed for the management of IBD using on-target and off-target strategies. It covers their preclinical, clinical assessment, mechanism of action, and safety profiles, and forecasts their appropriateness in the management of IBD. The review presents useful insights into the most promising candidates for repurposing, like anti-inflammatory and anti-apoptotic troxerutin, which has been found to improve the DSS-induced colitis in rats, an antiosteoarthritic drug diacetylrhein that has been found to have remarkable ameliorating effects on DSS-induced colitis via anti-oxidant and anti- inflammatory properties and by influencing both apoptosis and pyroptosis. Topiramate, an antiepileptic and anticonvulsant drug, has remarkably decreased overall pathophysiological and histopathological events in the experimental model of IBD in rodents by its cytokine inhibitory action.

Thalidomide Attenuates Colitis and Is Associated with the Suppression of M1 Macrophage Polarization by Targeting the Transcription Factor IRF5

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory bowel disease. The TNF-α inhibitor thalidomide is reported to be effective for inducing remission in pediatric Crohn's disease (CD) and adults with refractory CD. The mechanisms underlying the immunomodulatory and anti-inflammatory properties of thalidomide are unclear.

METHODS

Histological assessments were firstly performed in thalidomide treated UC patients. Then the effect of thalidomide in vivo was detected in DSS-induced murine colitis. The mechanism involving IRF5, and M1 macrophage polarization was investigated by using plasmid transfection, western blotting, and real-time PCR. Finally, AOM/DSS model was used to detect the role of thalidomide in colitis associated cancer.

RESULTS

We first found that treatment with thalidomide could ameliorate colon inflammation for 8 weeks and promote mucosal healing in human UC. Moreover, treatment with thalidomide protected mice from dextran sodium sulfate (DSS)-induced acute colitis, with treated mice presenting with a higher body weight, lower histological score, and lower DAI. Concomitantly, in comparison with control mice, mice treated with thalidomide showed accelerated recovery following colitis after 10 days of thalidomide treatment. Mechanistically, we observed that thalidomide could increase epithelial cell self-renewal capacity and modulate M1/M2 polarization by decreasing M1 markers CD86 and CCR7 and increasing M2 protein signatures CD206 and Arg-1. Thalidomide controls M1 macrophage polarization by targeting the transcription factor IRF5. Finally, by using the classical AOM/DSS model, we found that thalidomide-treated mice presented with a lower incidence and growth of colitis-associated carcinoma (CAC) than negative control mice.

CONCLUSIONS

In summary, thalidomide suppresses M1 polarization in the inflammatory microenvironment, which not only attenuates colonic inflammation to facilitate mucosal healing after DSS-induced injury but also represses the progression of CAC.

Protective Effect of Thalidomide on 2,4,6-Trinitrobenzenesulfonic Acid-Induced Experimental Colitis in Rats via the Inhibition of T Helper 17 Cells

OBJECTIVE

To observe the effects of thalidomide on 2,4,6-trinitrobenzenesulfonic acid- (TNBS-) induced experimental colitis in rats and to explore the possible mechanism of thalidomide in the treatment of CD.

METHODS

Forty SD rats were randomly assigned into a healthy control group and TNBS-induced colitis groups, including an untreated TNBS-induced colitis group, a low-dose thalidomide group, and a high-dose thalidomide group, with 10 rats in each. After 7 days, the disease activity index (DAI), colon macroscopic damage index (CMDI), and tissue damage index (TDI) were evaluated. The colonic protein and mRNA expression levels of interleukin-6 (IL-6), IL-17, IL-23, and retinoic acid receptor-related orphan nuclear receptor gamma t (RORγt) were determined using immunohistochemistry, western blot, and qRT-PCR.

RESULTS

Relative to the untreated TNBS-induced colitis group, the DAI, CMDI, and TDI were all reduced following the administration of thalidomide. Analytical testing (immunohistochemistry, western blot, and qRT-PCR) shows that IL-6, IL-17, IL-23, and RORγt protein and mRNA expression levels were significantly reduced by thalidomide (p < 0.05 for all) and that these levels were significantly lower in the high-dose thalidomide group than in the low-dose thalidomide group (p < 0.05 for all).

CONCLUSIONS

Thalidomide effectively alleviated the symptoms and intestinal inflammatory injury induced by TNBS in rats, the effect of which was dose-dependent. The underlying mechanism may be a reduction in the expression levels of IL-6, IL-17, IL-23, and RORγt in colonic tissue and then subsequent inhibition of the differentiation and function of Th17 cells, thus further alleviating the intestinal inflammatory response.

Drug release in vivo and efficacy evaluation of a new colon targeted powder of total saponins of Pulsatilla

Based on the anti-ulcerative colitis (UC) effect of total saponins of Pulsatilla (PTS), a pH dependent colonic targeting particle design powder of PTS was prepared. The core-shell composite particle design powder of PTS was prepared with pH sensitive polymer material Eudragit S100 superfine powder as shell and the drug as core. The release of PTS composite particle design powder was increased in the artificial colon fluid and decreased in the artificial stomach and small intestine fluid. In this paper, the release performance of Pulsatilla saponin D in PTS and the ulcerative colitis model induced by TNBS in rats were used to evaluate the targeting of PTS composite particle design powder in colon. The results showed that the content of Pulsatilla saponin D in colon tissue was significantly higher than that of the original drug group after oral administration of PTS composite particle design powder. The solubility of Pulsatilla saponin D in colon tissue was also higher than that in the stomach and small intestine. The peak time and retention time in vivo were prolonged, and the maximum blood concentration was decreased (C_max). The effect of colonic targeting powder of PTS (50 mg/kg)on anti-ulcerative colitis induced by TNBS in SD rats was better than the original drug (200 mg/kg). Therefore, it is a great significance to make the PTS into colon targeted preparation for improving bioavailability, efficacy and reducing gastrointestinal stimulation.

Rat models of high risk colorectal anastomoses 1

PURPOSE

To evaluate the most frequent surgical techniques of high-risk colorectal anastomoses in rats.

METHODS

Wistar rats were enrolled in three different models comprising inflammatory (TNBS enema), vascular (portal vein occlusion) or obstructive (a non-ischemic constricting ring) mechanisms associated with colonic anastomosis that had accomplished after these former lesions. Histological analyses (Hematoxylin and eosin and Picrosirius red) were performed.

RESULTS

All anastomoses techniques were associated with risk factors and had complications, mainly anastomotic leakage. In Study 1, the use of a pharmacological agent, trinitrobenzene sulfonic acid (TNBS) mimicked an inflammatory bowel disease such as Crohn's disease with 50% of anastomosis leakage, the higher percentage among all models tested. In Study 2, after portal ischemia followed by reperfusion it was observed a dense neutrophil infiltrate in the midst of necrotic tissue and fibrin at the anastomotic site and 5 days after the anastomosis, no collagen was produced. In Study 3, 5 days after the mechanical obstruction some denuded areas of epithelium with marked oedema of mucosa and submucosa were seen, at the anastomotic site and anastomosis group showed some reduction of collagen density when compared with Control/Sham group.

CONCLUSION

All the experimental surgical techniques tested in rats were associated with high-risk colorectal anastomoses and were useful to study colonic anastomotic healing and intestinal leakage.

Innate Immune Activation Can Trigger Experimental Spondyloarthritis in HLA-B27/Huβ2m Transgenic Rats

Spondyloarthritis (SpA) does not display the typical features of auto-immune disease. Despite the strong association with MHC class I, CD8⁺ T cells are not required for disease induction in the HLA-B27/Huβ2m transgenic rats. We used Lewis HLA-B27/Huβ2m transgenic rats [21-3 × 283-2]F1, HLA-B7/Huβ2m transgenic rats [120-4 × 283-2]F1, and wild-type rats to test our hypothesis that SpA may be primarily driven by the innate immune response. In vitro, splenocytes were stimulated with heat-inactivated Mycobacterium tuberculosis and cytokine expression and production was measured. In vivo, male and female rats were immunized with 30, 60, or 90 µg of heat-inactivated M. tuberculosis and clinically monitored for spondylitis and arthritis development. After validation of the model, we tested whether prophylactic and therapeutic TNF targeting affected spondylitis and arthritis. In vitro stimulation with heat-inactivated M. tuberculosis strongly induced gene expression of pro-inflammatory cytokines such as TNF, IL-6, IL-1α, and IL-1β, in the HLA-B27 transgenic rats compared with controls. In vivo immunization induced an increased spondylitis and arthritis incidence and an accelerated and synchronized onset of spondylitis and arthritis in HLA-B27 transgenic males and females. Moreover, immunization overcame the protective effect of orchiectomy. Prophylactic TNF targeting resulted in delayed spondylitis and arthritis development and reduced arthritis severity, whereas therapeutic TNF blockade did not affect spondylitis and arthritis severity. Collectively, these data indicate that innate immune activation plays a role in the initiation of HLA-B27-associated disease and allowed to establish a useful in vivo model to study the cellular and molecular mechanisms of disease initiation and progression.

Corticotropin Releasing Hormone and Urocortin 3 Stimulate Vascular Endothelial Growth Factor Expression through the cAMP/CREB Pathway

Colonic epithelium is the first line of defense against various pathological offenses in the gut. Previous studies have shown that the peptides of the corticotropin-releasing hormone (CRH) family modulate vascular endothelial growth factor (VEGF)-A production in other cells. Here we sought to investigate whether CRH and urocortin (Ucn) 3 regulate VEGF-A secretion in colonocytes through CRH receptors and to elucidate the underlying mechanism of action. CRH and Ucn 3 significantly increased the expression levels of VEGF-A mRNA and protein through CRH receptor 1 and 2, respectively, in human colonic epithelial cells and primary mouse intestinal epithelial cells. Underlying mechanisms involve activation of adenylyl cyclase with subsequent increase of intracellular cAMP level and increased DNA binding activity of transcription factor CREB on VEGF-A promoter region. Finally, genetic deficiency of CREB decreased intestinal inflammation and VEGF-A expression in a dextran sodium sulfate-induced colitis model. These results show that activation of CRH receptors by CRH ligands stimulates VEGF-A expression in intestinal epithelial cells through the cAMP/CREB pathway. Since VEGF-A boosts inflammatory responses through angiogenesis, these data suggest that CREB may be a key effector of CRH and Ucn 3-dependent inflammatory angiogenesis.

Protective effect of royal jelly in 2,4,6 trinitrobenzene sulfonic acid-induced colitis in rats

OBJECTIVES

In the present study, we evaluated immunological and immunomodulatory properties of royal jelly (RJ) in 2,4,6 trinitrobenzene sulfonic acid (TNBS)-induced colitis in rats.

MATERIALS AND METHODS

Eighteen adult female Wistar albino rats were divided into three groups of six animals each: a control group that received only saline solution, a TNBS-induced colitis group, and a TNBS-colitis+RJ group that received 250 mg/kg/day of RJ for seven days before the induction of colitis, following by the same treatment for an additional seven days. At the end of the experiment, cardiac blood and colon samples were obtained under deep anaesthesia from the animals in all groups. Serum interleukin-1β (IL-1β), tumour necrosis factor-alpha (TNF-α) and IL-10 levels were analyzed with an enzyme-linked immunosorbent assay (ELISA). Five-micrometre-thick sections were stained with haematoxylin-eosin (H&E) for microscopic evaluations. For immunohistochemical evaluations, the paraffin sections were stained with anti-CD3 (cluster of differentiation), anti-CD5, anti-CD8 and anti-CD45.

RESULTS

The results showed that the oral RJ treatment inhibited proinflammatory cytokines, IL-1β and TNF-α secretion, while increasing anti-inflammatory cytokine IL-10 production in the TNBS-induced colitis+RJ group compared with the colitis group not treated with RJ. The colitis was not as severe in the colitis+RJ group, with ulcerative damage, weight loss and inflammatory scores suggesting that impaired CD3-, CD5-, CD8- and CD45-positive T cell immune responses likely mediated the anti-inflammatory effect.

CONCLUSION

The antioxidant and anti-inflammatory properties of RJ protected colon mucosa against TNBS-induced colitis in rats orally treated with RJ.

Members of the novel UBASH3/STS/TULA family of cellular regulators suppress T-cell-driven inflammatory responses in vivo

The UBASH3/STS/TULA family consists of two members sharing substantial homology and a similar multi-domain architecture, which includes a C-terminal histidine phosphatase domain capable of dephosphorylating phosphotyrosine-containing substrates. TULA-family proteins act as downregulators of receptor-induced activation in several cell types, including T cells and platelets. Deletion of both family members in mice has been shown to result in hyperresponsiveness of T cells to T-cell receptor (TCR)/CD3 complex engagement, but little is known about the biological consequences of double knockout (dKO) and especially of either single KO (sKO). We elucidated the biological consequences of the lack of TULA-family proteins in dKO and TULA and TULA-2 sKO animals. In order to do so, we examined immune responses in Trinitrobenzene sulfonic acid (TNBS)-induced colitis, a mouse model of human inflammatory bowel disease, which is characterized by the involvement of multiple cell types, of which T cells have a crucial role, in the development of a pathological inflammatory condition. Our data indicate that TNBS treatment upregulates T-cell responses in all KO mice studied to a significantly higher degree than in wild-type mice. Although the lack of either TULA-family member exacerbates inflammation and T-cell responses in a specific fashion, the lack of both TULA and TULA-2 in dKO exerts a higher effect than the lack of a single family member in TULA and TULA-2 sKO. Analysis of T-cell responses and TCR-mediated signaling argues that the proteins investigated affect T-cell signaling by regulating phosphorylation of Zap-70, a key protein tyrosine kinase.

The impact of JNK inhibitor D-JNKI-1 in a murine model of chronic colitis induced by dextran sulfate sodium

Purpose:

The c-Jun N-terminal kinases (JNK) are involved in the activation of T cells and the synthesis of proinflammatory cytokines. Several studies have established the relevance of the JNK pathway in inflammatory bowel diseases. The present study analyzed the therapeutic effect of D-JNKI-1, a specific JNK-inhibiting peptide, in a low-dose dextran sulfate sodium (DSS) model of chronic colitis.

Methods:

DSS colitis was induced in female C57/BL6 mice by cyclic administration using different concentrations of DSS (1.0% and 1.5%). Mice in the intervention groups received subcutaneous administration of 1 μg/kg D-JNKI-1 on days 2, 12, and 22. They were monitored daily to assess the severity of colitis, body weight, stool consistency, and the occurrence of occult blood or gross rectal bleeding using evaluation of the disease activity index. The animals were sacrificed after 30 days, and the inflamed intestine was histologically evaluated using a crypt damage score. Immunohistochemical quantification of CD4⁺ and CD8⁺ cells was also carried out.

Results:

Administration of 1 μg/kg D-JNKI-1 resulted in a significant decrease in the disease activity index (P = 0.013 for 1.0% DSS; P = 0.007 for 1.5% DSS). As a mild form of colitis was induced, histological examination did not show any distinct damage to the mucosa and crypts. However, expression of CD4⁺ and CD8⁺ cells was reduced in mice treated with D-JNKI-1 (not significant).

Conclusion:

Administration of D-JNKI-1 resulted in a clinical attenuation of chronic DSS colitis, and a therapeutic effect of D-JNKI-1 must therefore be assumed. The decrease in CD4⁺ and CD8⁺ cells may reflect the influence of D-JNKI-1 on T-cell activation, differentiation, and migration.

The JNK inhibitor XG-102 protects against TNBS-induced colitis

The c-Jun N-terminal kinase (JNK)-inhibiting peptide D-JNKI-1, syn. XG-102 was tested for its therapeutic potential in acute inflammatory bowel disease (IBD) in mice. Rectal instillation of the chemical irritant trinitrobenzene sulfonic acid (TNBS) provoked a dramatic acute inflammation in the colon of 7–9 weeks old mice. Coincident subcutaneous application of 100 µg/kg XG-102 significantly reduced the loss of body weight, rectal bleeding and diarrhoea. After 72 h, the end of the study, the colon was removed and immuno-histochemically analysed. XG-102 significantly reduced (i) pathological changes such as ulceration or crypt deformation, (ii) immune cell pathology such as infiltration and presence of CD3- and CD68-positive cells, (iii) the production of tumor necrosis factor (TNF)-α in colon tissue cultures from TNBS-treated mice, (iv) expression of Bim, Bax, FasL, p53, and activation of caspase 3, (v) complexation of JNK2 and Bim, and (vi) expression and activation of the JNK substrate and transcription factor c-Jun. A single application of subcutaneous XG-102 was at least as effective or even better depending on the outcome parameter as the daily oral application of sulfasalazine used for treatment of IBD.

The successful and substantial reduction of the severe, TNBS-evoked intestinal damages and clinical symptoms render the JNK-inhibiting peptide XG-102 a powerful therapeutic principle of IBD.

Validation and optimization of experimental colitis induction in rats using 2, 4, 6-trinitrobenzene sulfonic acid

Trinitrobenzene sulfonic acid (TNBS)-induced colitis is one of the most common methods for studying inflammatory bowel disease in animal models. Several factors may, however, affect its reproducibility, rate of animal mortality, and macroscopic and histopathological outcomes. Our aim was to validate the main contributing factors to this method and compare the effects of different reference drugs upon remission of resultant colon injuries. TNBS was dissolved in 0.25 ml of ethanol (50% v/v) and instilled (25, 50, 100 and 150 mg/kg) intracolonically to the male Wistar rats. After determination of optimum dose of TNBS in male rats and assessment of this dose in female rats, they were treated with reference drugs including dexamethasone [1 mg/kg, intraperitoneally (i.p.) and 2 mg/kg, orally (p.o.)], Asacol (mesalazine, 100 mg/kg, p.o.; 150 mg/kg, enema) and hydrocortisone acetate (20 mg/kg, i.p.; 20 mg/kg, enema) which started 2 h after colitis induction and continued daily for 6 consecutive days. Thereafter, macroscopic and microscopic parameters and clinical features were assessed and compared in different groups. We found that the optimum dose of TNBS for the reproducibility of colonic damage with the least mortality rate was 50 mg/kg. Amongst studied reference drugs, hydrocortisone acetate (i.p.), dexamethasone (i.p. and p.o.) and Asacol (p.o.) significantly diminished the severity of macroscopic and microscopic injuries and could be considered effective for experimental colitis studies in rats . Our findings suggest that optimization of TNBS dose is essential for induction of colitis under the laboratory conditions; and gender exerts no impact upon macroscopic and histological characteristics of TNBS-induced colitis in rats. Furthermore, the enema forms of hydrocortisone and Asacol are not appropriate reference drugs.

Immunomodulatory and therapeutic potential of a mycelial lectin from Aspergillus nidulans

Lectins bind to surface receptors on target cells, and activate a cascade of events, eventually leading to altered immune status of host. The immunomodulatory potential of purified lectin from Aspergillus nidulans was evaluated in Swiss albino mice treated intraperitoneally with seven different doses of purified lectin. Lectin prevented BSA-induced Arthus reaction and systemic anaphylaxis. The enhanced functional ability of macrophages was evident from respiratory burst activity and nitric oxide production in splenocyte cultures. Interferon-gamma and interleukin-6 levels were significantly up-regulated in treated groups. Maximum stimulatory effect was observed at the dose of 1.5 mg/kg body weight. Therapeutic potential of A. nidulans lectin was assessed against trinitrobenzene sulfonic acid-induced ulcerative colitis in male Wistar rats. Rats pre-treated with 80 mg/kg body weight of purified lectin intraperitoneally prior to colitis induction showed lesser disease severity and recovery within 7 days, while rats post-treated with the same dose showed recovery in 11 days. The results demonstrate immunomodulatory effects of A. nidulans lectin in Swiss albino mice, resulting in improved immune status of the animals and unfold its curative effect against ulcerative colitis in rat model. This is the first report on immunomodulatory and therapeutic potential of a lectin from microfungi.

The effect of pentoxifylline and its metabolite-1 on inflammation and fibrosis in the TNBS model of colitis

TNBS-induced colitis has characteristics resembling human Crohn's disease including transmural inflammation, ulceration, and fibrosis. Current treatments target acute symptoms but do not necessarily prevent fibrotic complications of the disease. The aim of this study was to determine the effect of pentoxifylline and its primary metabolite (M-1) on fibrosis in the TNBS-induced colitis model. Myeloperoxidase activity and interleukin-18 are indicators of inflammation and were elevated in the TNBS model. The morphology damage score assesses colon damage and was also elevated in the TNBS model. Collagen as the indicator of fibrosis was quantified and visualized by the Sirius Red/Fast Green staining technique and collagen type I was assessed by Western analysis. Collagen was elevated in the TNBS-induced model. Pentoxifylline and M-1 treatment significantly attenuated colon damage and inflammation in TNBS-colitis (P<0.05). M-1 treatment significantly reduced the TNBS-induced increase in colon weight, colon thickness and total collagen content (P<0.05). Results suggest that pentoxifylline and M-1 inhibit intestinal fibrosis in this experimental model and may prove beneficial in the treatment of intestinal fibrosis associated with human Crohn's disease with the added benefit of inhibiting inflammation and ulceration. This is the first study to examine the effects of racemic M-1 in vivo and one of the few studies to examine the effect of drugs on both inflammation and fibrosis in an experimental model of colitis.

Infliximab therapy inhibits inflammation-induced angiogenesis in the mucosa of patients with Crohn's disease

OBJECTIVES

Inflammation-driven angiogenesis contributes to the pathogenesis of inflammatory bowel disease (IBD). In line with this, the efficacy of inhibitors of angiogenesis has been demonstrated in experimental models of colitis. Currently, the ability of infliximab, an anti-tumor necrosis factor-α (TNF-α) agent that is highly beneficial in patients with IBD, to affect mucosal angiogenesis in patients with Crohn's disease (CD) and ulcerative colitis (UC) is unknown.

METHODS

Patients with active CD (n=14) were treated with infliximab for 1 year, and peripheral blood and intestinal mucosa samples were collected before and after treatment. Mucosal angiogenesis was evaluated by CD31 and Ki-67 staining in endoscopic biopsies at baseline (week 0) and at week 54. The release of vascular endothelial growth factor-A (VEGF-A) by cultured mucosal extracts was measured by enzyme-linked immunosorbent assay (ELISA), before and after administration of infliximab, as well as in cultures of human intestinal fibroblasts (HIFs) stimulated with TNF-α in the presence or absence of infliximab. Migration of human intestinal microvascular endothelial cells (HIMECs) was investigated by migration assays.

RESULTS

Microvessel density was significantly higher in the mucosa from patients with CD compared with tissue from healthy control individuals. Of the 14 patients, 8 (57%) showed a clinical remission in response to infliximab, which was associated with a significant reduction of microvascular density. Morphometric vessel analysis further confirmed the significant reduction of the area of vascular section after administration of infliximab. Furthermore, the expression levels of the proliferation marker Ki-67 in endothelial cells were significantly reduced after treatment. The mucosal concentration of VEGF-A was also significantly decreased, whereas in vitro exposure of HIF to infliximab virtually abolished TNF-α-induced VEGF-A production. These phenomena did not occur in patients who showed no clinical response to infliximab.

CONCLUSIONS

Administration of infliximab downregulates mucosal angiogenesis in patients with CD and restrains production of VEGF-A by mucosal fibroblasts. It is proposed that this ameliorates inflammation-driven angiogenesis in the gut mucosa and contributes to the therapeutic efficacy of blockade of TNF-α.

Role of the endothelium in inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are a complex group of diseases involving alterations in mucosal immunity and gastrointestinal physiology during both initiation and progressive phases of the disease. At the core of these alterations are endothelial cells, whose continual adjustments in structure and function coordinate vascular supply, immune cell emigration, and regulation of the tissue environment. Expansion of the endothelium in IBD (angiogenesis), mediated by inflammatory growth factors, cytokines and chemokines, is a hallmark of active gut disease and is closely related to disease severity. The endothelium in newly formed or inflamed vessels differs from that in normal vessels in the production of and response to inflammatory cytokines, growth factors, and adhesion molecules, altering coagulant capacity, barrier function and blood cell recruitment in injury. This review examines the roles of the endothelium in the initiation and propagation of IBD pathology and distinctive features of the intestinal endothelium contributing to these conditions.

Effects on neuroendocrinoimmune network of Lizhong Pill in the reserpine induced rats with spleen deficiency in traditional Chinese medicine

AIM OF THE STUDY

Lizhong Pill, composed of radix Ginseng (Panax ginseng C.A. Meyer), rhizoma Zingiberis (Zingiber officinale Roscoe), rhizoma Atractylodis Macrocephalae (Atractylodes macrocephala Koidz.) and radix Glycytthizae (Glycyrrhiza uralensis Fisch.), is a classical herbal product for curing spleen deficiency in traditional Chinese medicine (TCM), and reserpine treated rats show similar signs to TCM spleen deficiency pattern. This paper is aimed to explore the regulatory effect on neuroendocrinoimmune network by Lizhong Pill in reserpine induced TCM spleen deficiency rats.

MATERIALS AND METHODS

100 healthy adult male SD rats, with a mean weight of 200 g, were randomly divided into five groups in average: control group, reserpine treated group, atropine treated group, treatment groups with Lizhong Pill at high dose and low dose (equal to the dosage of crude drugs for 4 g/kg/d and 8 g/kg/d). Rats in reserpine treated group were induced by intraperitoneal injection of reserpine at 0.5 mg/kgd for 4 weeks. The levels of IL-1, IL-6 and gastrin were measured with radioimmunoassay, TNF-α and IFN-γ in serum were measured with ELISA, the level of vasoactive intestinal peptide (VIP) and substance P (SP) in small intestine were determined with radioimmunoassay, and the TNF-α and TGF-β positive cells in small intestine were detected by immunohistological staining. Data were analyzed with SAS 9.1 software package.

RESULTS

The rats in reserpine treated group, body weight, concentrations of IFN-γ, IL-1 and TNF-α in serum, expression of TGF-β in small intestine, VIP in small intestine decreased (P<0.05), and the level of IL-6 in serum, expression of TNF-α, SP in small intestine and gastrin were increased (P<0.05). Administration of Lizhong Pill at high dose could increase the body weights at day 21, and the weights of rats in Lizhong Pill groups were much higher compared to reserpine treated group. At high dose of Lizhong Pill could increase the level of TNF-α in serum. Lizhong Pill at high dose and low dose could reverse the changes of IL-1, IL-6 and IFN-γ, gastrin, expression of TGF-β and TNF-α, VIP and SP in small intestine.

CONCLUSIONS

The rats treated with reserpine, with similar signs to TCM spleen deficiency, show neuroendocrinoimmune disorders, and the restoration of the neuroendocrinoimmune disorders might be the part of mechanism of Lizhong Pill for reinforcing TCM spleen deficiency.

In vitro ultrasound biomicroscopic imaging of colitis in rats

OBJECTIVE

The purpose of this study was to show the feasibility of 50-MHz ultrasound biomicroscopy (UBM) to image the rat colon.

METHODS

B-mode images were obtained from ex vivo colon samples (n = 4) collected from Rattus norvegicus (Berkenhout, 1769) rats, with 2,4,6-trinitrobenzene sulfonic acid-induced colitis in 3 of them. Left colon rectangular fragments (5 x 5 mm) were obtained after necropsy, and UBM images were acquired with the samples immersed in saline at 37 degrees C. All layers of the normal intestinal wall were analyzed according to their thickness and the presence of uneven bowel mucosa (ulcers). The folds and layers detected by UBM were correlated with histopathologic analysis.

RESULTS

The 4 layers of the normal colon were identified on the UBM images: the mucosa (hyperechoic), muscularis mucosae (hypoechoic), submucosa (hyperechoic), and muscularis externa (hypoechoic). On 2 UBM images, superficial ulcers were detected, approximately 0.5 mm in size, with intestinal involvement limited to the mucosa. The histopathologic analysis verified enlargement of submucosa layers due to an edema associated with sub-mucosa leukocyte infiltration. On 1 UBM image, it was possible to detect a deep ulcer, which was confirmed by the light microscopic analysis.

CONCLUSIONS

An ultrasound imaging system was scaled and optimized to visualize the rat colon. Ultrasound biomicroscopy provided axial and lateral resolutions close to 25 and 45 mum, respectively, and adequate penetration depth to visualize the whole thickness of an inflamed colon. The system identified the colon layers and was able to detect mural changes and superficial ulcers on the order of 500 mum.

Thalidomide: mechanisms of action

The classification of thalidomide as an orphan drug with anti-inflammatory actions has led to its off-label use in conditions refractory to other medications. Although the observed clinical effects of thalidomide suggest it to have immunomodulatory capabilities, the mechanism of action is unclear. Here we review both the positive and negative studies of thalidomide at the bench in order to improve our understanding of the possible mechanisms of this drug in treating a variety of diseases at the bedside. Studies on the effects of thalidomide on the innate and adaptive immune system as well as tumorigenesis and angiogenesis are discussed.

Thalidomide effect in endothelial cell of acute radiation proctitis

AIM: To determine whether thalidomide prevents microvascular injury in acute radiation proctitis in white rats.

METHODS: Fourteen female Wistar rats were used: six in the radiation group, six in the thalidomide group, and two in normal controls. The radiation and thalidomide groups were irradiated at the pelvic area using a single 30 Gy exposure. The thalidomide (150 mg/kg) was injected into the peritoneum for 7 d from the day of irradiation. All animals were sacrificed and the rectums were removed on day 8 after irradiation. The microvessels of resected specimens were immunohistochemically stained with thrombomodulin (TM), von Willebrand Factor (vWF), and vascular endothelial growth factor (VEGF).

RESULTS: The microscopic scores did not differ significantly between the radiation and thalidomide groups, but both were higher than in the control group. Expression of TM was significantly lower in the endothelial cells (EC) of the radiation group than in the control and thalidomide groups (P < 0.001). The number of capillaries expressing vWF in the EC was higher in the radiation group (15.3 ± 6.8) than in the control group (3.7 ± 1.7), and the number of capillaries expressing vWF was attenuated by thalidomide (10.8 ± 3.5, P < 0.001). The intensity of VEGF expression in capillaries was greater in the radiation group than in the control group and was also attenuated by thalidomide (P = 0.003).

CONCLUSION: The mechanisms of acute radiation-induced proctitis in the rats are related to endothelial cell injury of microvessel, which may be attenuated with thalidomide.

Upregulation of vascular endothelial growth factor isoform VEGF-164 and receptors (VEGFR-2, Npn-1, and Npn-2) in rats with cyclophosphamide-induced cystitis

Regulation of the VEGF-VEGF receptor system was examined in the urinary bladder after acute (2-48 h) and chronic (10 days) cyclophosphamide (CYP)-induced cystitis. ELISAs demonstrated significant (P < or = 0.01) upregulation of VEGF in whole urinary bladder with acute and chronic CYP-induced cystitis; however, the magnitude of increase was greater after acute (2-4 h) cystitis. Immunohistochemistry for VEGF immunoreactivity revealed a significant (P < or = 0.05) increase in VEGF immunoreactivity in the urothelium, suburothelial vasculature, and detrusor smooth muscle with acute (4 and 48 h) CYP treatment. RT-PCR identified the isoform VEGF-164, the VEGF receptor VEGFR-2, and the VEGF co-receptors neuropilin (Npn)-1 and Npn-2 in the urinary bladder. Quantitative PCR demonstrated upregulation of VEGF-164 transcript with acute and chronic CYP-induced cystitis, but VEGFR-2, Npn-1, and Npn-2 transcripts were upregulated (P < or = 0.01) in whole bladder only with chronic CYP-induced cystitis. Additional studies demonstrated regulation of VEGF transcript expression in the urinary bladder by nerve growth factor (NGF) in a novel line of NGF-overexpressing mice. These studies demonstrated that urinary bladder inflammation and NGF regulate the VEGF-VEGF receptor system in the urinary bladder. Functional role(s) for the VEGF-VEGF receptor system in urinary bladder inflammation remain to be determined.