Transforming growth factor-β1 and its receptors in patients with ulcerative colitis

Neohesperidin Dihydrochalcone Ameliorates Experimental Colitis via Anti-Inflammatory, Antioxidative, and Antiapoptosis Effects

Neohesperidin dihydrochalcone (NHDC) is a citrus-originated, seminatural sweetener. There is no investigation concerning the effect of NHDC on ulcerative colitis. The purpose of this study was to determine the therapeutic and protective effects of NHDC in Wistar Albino rats. NHDC was given for 7 days after or before colitis induction. The results showed that NHDC significantly reduced the interleukin-6 (IL-6), interleukin-10 (IL-10), transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) levels. Catalase levels did not show a significant difference between the groups. NHDC provided a remarkable decrease in the expression levels of cyclooxygenase-2 (COX-2), myeloperoxidase (MPO), malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and nuclear factor kappa B (NF-κB). Total antioxidant status (TAS) levels were significantly elevated in NHDC treatment groups, while total oxidant status (TOS) and oxidative stress index (OSI) levels were significantly decreased. NHDC provided remarkable improvement in histological symptoms such as epithelial erosion, edema, mucosal necrosis, inflammatory cell infiltration, and hemorrhage. Also, caspase-3 expression levels were statistically decreased in NHDC treatment groups. The results indicated that NHDC might be a protection or alternative treatment for ulcerative colitis.

TGF-β signaling in health, disease, and therapeutics

Transforming growth factor (TGF)-β is a multifunctional cytokine expressed by almost every tissue and cell type. The signal transduction of TGF-β can stimulate diverse cellular responses and is particularly critical to embryonic development, wound healing, tissue homeostasis, and immune homeostasis in health. The dysfunction of TGF-β can play key roles in many diseases, and numerous targeted therapies have been developed to rectify its pathogenic activity. In the past decades, a large number of studies on TGF-β signaling have been carried out, covering a broad spectrum of topics in health, disease, and therapeutics. Thus, a comprehensive overview of TGF-β signaling is required for a general picture of the studies in this field. In this review, we retrace the research history of TGF-β and introduce the molecular mechanisms regarding its biosynthesis, activation, and signal transduction. We also provide deep insights into the functions of TGF-β signaling in physiological conditions as well as in pathological processes. TGF-β-targeting therapies which have brought fresh hope to the treatment of relevant diseases are highlighted. Through the summary of previous knowledge and recent updates, this review aims to provide a systematic understanding of TGF-β signaling and to attract more attention and interest to this research area.

Skin damage caused by scale loss modifies the intestine of chronically stressed gilthead sea bream (Sparus aurata, L.)

The present study was designed to test if the damage caused by scale loss provokes a change in other innate immune barriers such as the intestine and how chronic stress affects this response. Sea bream (Sparus aurata) were kept in tanks at low density (16 kg m^-3, LD) or exposed to a chronic high density (45 kg m^-3, HD) stress for 4 weeks. Scales were then removed (approximately 50%) from the left flank in the LD and HD fish. Intestine samples (n = 8/group) were examined before and at 12 h, 3 days and 7 days after scale removal. Changes in the morphology of the intestine revealed that chronic stress and scale loss was associated with intestinal inflammation. Specifically, enterocyte height and the width of the lamina propria, submucosa and muscle layer were significantly increased (p < 0.05) 3 days after skin damage in fish under chronic stress (HD) compared to other treatments (LDWgut3d or HDgut0h). This was associated with a significant up-regulation (p < 0.05) in the intestine of gene transcripts for cell proliferation (pcna) and anti-inflammatory cytokine tgfβ1 and down-regulation of gene transcripts for the pro-inflammatory cytokines tnf-α and il1β (p < 0.05) in HD and LD fish 3 days after scale removal compared to the undamaged control (LDgut0h). Furthermore, a significant up-regulation of kit, a marker of mast cells, in the intestine of HDWgut3d and LDWgut3d fish suggests they may mediate the crosstalk between immune barriers. Skin damage induced an increase in cortisol levels in the anterior intestine in HDWgut12 h fish and significant (p < 0.05) down-regulation of mr expression, irrespective of stress. These results suggest glucocorticoid levels and signalling in the intestine of fish are modified by superficial cutaneous wounds and it likely modulates intestine inflammation.

Cytokines in the colon, central nervous system and serum of irritable bowel syndrome rats

Objective

The aim of this study was to detect the expression of interleukin (IL)-1β and transforming growth factor (TGF)-β1 in the colonic tissue and serum of irritable bowel syndrome (IBS) rats, as well as the distribution and expression of corticotropin-releasing factor (CRF) in the spinal cord and brain of the visceral hypersensitivity rats, thus to ascertain the mechanism of visceral hypersensitivity signal conduction pathway.

Methods

The expression of IL-1β and TGF-β1 in the colonic tissue and serum of IBS rats was screened by the liquid chip technology and verified by RT-PCR technology. Then the quantitative analysis of CRF in the spinal cord and brain was achieved by the immunohistochemical method and computerized image system.

Result

The rat model with visceral hypersensitivity was successfully established. Among the screened indicators of IL-1β and TGF-β1 in colon tissue and serum, only the expression of IL-1β in the model group was up-regulated (P < 0.05). The immunohistochemical method showed that CRF was expressed in the spinal cord, hypothalamus, and the third ventricle. The positive index number of the model groups was higher than that of the control group (P < 0.01).

Conclusion

From the research, it can be inferred that IL-1β may participate in the pathogenesis mechanism of IBS via regulating the colon function. The increasing expression of CRF linked to stress in the spinal cord, hypothalamus and the third ventricle indicated that it might play an important role in the mechanisms of visceral hypersensitivity signal conduction pathway.

Salivary Stress/Immunological Markers in Crohn's Disease and Ulcerative Colitis

There is continuous and growing interest in research into new alternatives to standard biomarkers to detect and follow-up disease, reducing physical and psychological stress in patients needing regular and invasive medical examinations for the evaluation of pathologies, including inflammatory bowel diseases (IBD). Saliva is one of the most promising body fluids in the research of new biomarkers, thanks to the large number of molecules it contains. Many molecules present in saliva are often directly correlated to their concentration in the blood but may be affected by the condition of the oral cavity. This means that a careful selection of a specific biomarker is required for each pathology, especially pathologies such as IBD, which may induce inflammation in the oral cavity. Here, we analyze the currently used and the proposed new salivary biomarkers (i.e., calprotectin, cytokines, IgA, cortisol, and oxidative stress markers) for the detection and follow-up of the main subtypes of IBD, known as ulcerative colitis and Crohn's disease.

Regulatory Effect of Sishen Pill on Tfh Cells in Mice With Experimental Colitis

The T follicular helper T (Tfh) cells play a significant role in the pathogenesis of inflammatory bowel disease (IBD), which is regulated by the Bcl-6/Blimp-1 pathway. Some studies have suggested that regulating activation of the Bcl-6/Blimp-1 pathway should be an effective method to treat IBD. Sishen Pill (SSP) has been used frequently to treat chronic colitis. Its mechanism is related to the downstream proteins in the Bcl-6/Blimp-1 pathway. However, it is unknown whether SSP regulates the function and differentiation of Tfh cells to treat IBD. In the present study, chronic colitis was induced by dextran sodium sulfate and treated with SSP for 7 days. SSP effectively treated chronic colitis, regulated the balance between Tfh10, Tfh17 and T follicular regulatory cells, while SSP increased the Blimp-1 level, inhibited expressions of Bcl-6, T-cell costimulator, programmed death (PD)-1 and PD-ligand 1 on the surface of Tfh cells. SSP inhibited activation of BcL-6, phosphorylated signal transducer and activator of transcription (p-STAT)3, signal lymphocyte activation molecule (SLAM)-associated protein but improved Blimp-1 and STAT3 expression in colonic tissues. The results indicated that SSP regulated the differentiation and function of Tfh cells to treat IBD, which was potentially related with inhibiting the Bcl-6/Blimp-1 pathway.

Clinical Significance of Hepatocyte Growth Factor and Transforming Growth Factor-Beta-1 Levels in Assessing Disease Activity in Inflammatory Bowel Disease

Background. Transforming growth factor-beta (TGF-β) and hepatocyte growth factor (HGF) are inflammatory cytokines which function as key regulators of immunological homeostasis and inflammatory responses. They have been linked to inflammatory bowel diseases (IBD). In this study, we aim to assess the levels of TGF-β and HGF and other inflammatory markers in patients with IBD and correlate them with the disease activity. Study Design. A cross-sectional study involving 100 patients with ulcerative colitis (UC) and 100 patients with Crohn's disease (CD) and 50 control subjects. TGF-β and HGF levels were measured and correlated with disease activity. Results and Conclusion. Serum levels of TGF-β and HGF were significantly higher in IBD patients compared with the control group. In the UC group, the levels of HGF and TGF-β were significantly higher than in the CD group. Levels of TGF-β and HGF correlate with the activity of IBD.

Network-Based Combinatorial CRISPR-Cas9 Screens Identify Synergistic Modules in Human Cells

Tumorigenesis is a complex process that is driven by a combination of networks of genes and environmental factors; however, efficient approaches to identifying functional networks that are perturbed by the process of tumorigenesis are lacking. In this study, we provide a comprehensive network-based strategy for the systematic discovery of functional synergistic modules that are causal determinants of inflammation-induced tumorigenesis. Our approach prioritizes candidate genes selected by integrating clinical-based and network-based genome-wide gene prediction methods and identifies functional synergistic modules based on combinatorial CRISPR-Cas9 screening. On the basis of candidate genes inferred de novo from experimental and computational methods to be involved in inflammation and cancer, we used an existing TGFβ1-induced cellular transformation model in colonic epithelial cells and a new combinatorial CRISPR-Cas9 screening strategy to construct an inflammation-induced differential genetic interaction network. The inflammation-induced differential genetic interaction network that we generated yielded functional insights into the genes and functional module combinations, and showed varied responses to the inflammation agents as well as active traditional Chinese medicine compounds. We identified opposing differential genetic interactions of inflammation-induced tumorigenesis: synergistic promotion and suppression. The synergistic promotion state was primarily caused by deletions in the immune and metabolism modules; the synergistic suppression state was primarily induced by deletions in the proliferation and immune modules or in the proliferation and metabolism modules. These results provide insight into possible early combinational targets and biomarkers for inflammation-induced tumorigenesis and highlight the synergistic effects that occur among immune, proliferation, and metabolism modules. In conclusion, this approach deepens the understanding of the underlying mechanisms that cause inflammation to potentially increase the cancer risk of colonic epithelial cells and accelerate the translation into novel functional modules or synergistic module combinations that modulate complex disease phenotypes.

SMAD4 Protein Expression Is Downregulated in Ileal Epithelial Cells from Patients with Crohn's Disease with Significant Inverse Correlation to Disease Activity

Background

Small mothers against decapentaplegic (SMAD)4 and SMAD7 are key regulatory components in the immunosuppressive transforming growth factor- (TGF-) β signaling pathway, which is defective in inflammatory bowel disease (IBD). SMAD4 may play an important role in the pathogenesis of IBD as indicated in experimental models of colitis.

Aims

To examine the ileal expression levels of SMAD4 and to correlate these with CD disease activity.

Methods

The material comprised 29 CD patients (13 with active disease, 16 in remission) and 9 asymptomatic patients referred for ileocolonoscopy as part of an adenoma surveillance program serving as controls. Patients were examined with ileocolonoscopy. Corresponding ileal biopsies were obtained for histological analysis and assessment of SMAD4 and SMAD7 protein expression by immunohistochemistry (IHC).

Results

The protein expression of SMAD4 was significantly downregulated in ileal tissue sections from CD patients as compared to healthy controls (p < 0.001). Further, luminal SMAD4 expression was inversely correlated with endoscopic (r_s = -0.315; p = 0.05) and histopathological activity (r_s = -0.40; p = 0.013).

Conclusions

The SMAD4 epithelial protein level was markedly downregulated in CD patients and inversely correlated with disease activity. This may contribute to defective mucosal TGF-β signaling in active IBD.

Plasma-induced signatures reveal an extracellular milieu possessing an immunoregulatory bias in treatment-naive paediatric inflammatory bowel disease

The inflammatory state associated with Crohn's disease (CD) and ulcerative colitis (UC) remains incompletely defined. To understand more clearly the extracellular milieu associated with inflammatory bowel disease (IBD), we employed a bioassay whereby plasma of treatment naive paediatric IBD patients (n = 22 CD, n = 15 UC) and unrelated healthy controls (uHC, n = 10) were used to induce transcriptional responses in a healthy leucocyte population. After culture, gene expression was measured comprehensively with microarrays and analysed. Relative to uHC, plasma of CD and UC patients induced distinct responses consisting, respectively, of 985 and 895 regulated transcripts [|log2 ratio| ≥ 0·5 (1·4-fold); false discovery rates (FDR) ≤ 0·01]. The CD:uHC and UC:uHC signatures shared a non-random, commonly regulated, intersection of 656 transcripts (χ(2)  = P < 0·001) and were highly correlative [Pearson's correlation coefficient = 0·96, 95% confidence interval (CI) = 0.96, 0.97]. Despite sharing common genetic susceptibility loci, the IBD signature correlated negatively with that driven by plasma of type 1 diabetes (T1D) patients (Pearson's correlation coefficient = -0·51). Ontological analyses revealed the presence of an immunoregulatory plasma milieu in IBD, as transcripts for cytokines/chemokines, receptors and signalling molecules consistent with immune activation were under-expressed relative to uHC and T1D plasma. Multiplex enzyme-linked immunosorbent assay (ELISA) and receptor blockade studies confirmed transforming growth factor (TGF)-β and interleukin (IL)-10 as contributors to the IBD signature. Analysis of CD patient signatures detected a subset of transcripts associated with responsiveness to 6-mercaptopurine treatment. Through plasma-induced signature analysis, we have defined a unique, partially TGF-β/IL-10-dependent immunoregulatory signature associated with IBD that may prove useful in predicting therapeutic responsiveness.

The Role of Neuropeptides in Mouse Models of Colitis

Inflammatory bowel disease (IBD) constitutes an important clinically significant condition that results in morbidity and mortality. IBD can be generally classified into either ulcerative colitis (UC) or Crohn's disease (CD) that differs in the clinical and histopathology. The role of neuropeptides in the pathogenesis of these conditions is becoming increasingly recognized for their importance in modulating the inflammatory state. Animal models provide the greatest insight to better understand the pathophysiology of both disorders which will hopefully allow for improved treatment strategies. This review will provide a better understanding of the role of murine models for studying colitis.

Uygur medicine Xipayi Kui Jie'an affects gene expression profiles in intestinal tissue lesions in a rat model of ulcerative colitis

Background

The aim of this study was to investigate the mechanisms underlying the therapeutic effect of Uygur medicine KJA on UC in a rat model.

Methods

UC was induced in Wistar rats by application of 2, 4-dinitrochlorobenzene and acetic acid and were then treated with three different doses of KJA, and normal saline as control. After treatment for 20 days, the gene expression profile of colonic tissue was analyzed by microarray and verified by quantitative real-time RT-PCR.

Results

Animals treated with the three different doses of KJA were compared with normal saline controls, wherein microarray analysis identified 1991, 2163, and 1677 differentially expressed genes respectively, of which 444 genes were raised and 670 genes were decrease spliced together in the three doses tested. The KEGG pathway analyses found commonly raised genes related to several different biological functions. Interesting genes included TRL2, IL-1β, TGF-β1, and NF-κB were confirmed by quantitative PCR.

Conclusions

The therapeutic effect of KJA on UC is likely explained by specific effects on the expression of genes, which are the effector molecules known to be involved in the development of UC. Further studies on differentially expressed genes will help explain the mechanism of action of Uygur medicine KJA.

How two sites of inflammation promote carcinogenesis: The role of macrophages in inflammation associated carcinogenesis

We recently reported that anti-inflammatory macrophages contribute to the initiation of colorectal carcinogenesis in IBD patients by inducing epithelial-mesenchymal-transition associated alterations in colonic epithelial cells. In this process, TGFβ1 dependent upregulation of the adhesion molecule L1CAM is one key event, paving the way to colitis associated tumorigenesis and metastatic spread.

Transforming growth factor-β induces transcription factors MafK and Bach1 to suppress expression of the heme oxygenase-1 gene

Transforming growth factor-β (TGF-β) has multiple functions in embryogenesis, adult homeostasis, tissue repair, and development of cancer. Here, we report that TGF-β suppresses the transcriptional activation of the heme oxygenase-1 (HO-1) gene, which is implicated in protection against oxidative injury and lung carcinogenesis. HO-1 is a target of the oxidative stress-responsive transcription factor Nrf2. TGF-β did not affect the stabilization or nuclear accumulation of Nrf2 after stimulation with electrophiles. Instead, TGF-β induced expression of transcription factors MafK and Bach1. Enhanced expression of either MafK or Bach1 was enough to suppress the electrophile-inducible expression of HO-1 even in the presence of accumulated Nrf2 in the nucleus. Knockdown of MafK and Bach1 by siRNA abolished TGF-β-dependent suppression of HO-1. Furthermore, chromatin immunoprecipitation assays revealed that Nrf2 substitutes for Bach1 at the antioxidant response elements (E1 and E2), which are responsible for the induction of HO-1 in response to oxidative stress. On the other hand, pretreatment with TGF-β suppressed binding of Nrf2 to both E1 and E2 but marginally increased the binding of MafK to E2 together with Smads. As TGF-β is activated after tissue injury and in the process of cancer development, these findings suggest a novel mechanism by which damaged tissue becomes vulnerable to oxidative stress and xenobiotics.

Different activation of TRAF4 and TRAF6 in inflammatory bowel disease

In recent years, interests combining the exploration of tumor necrosis factor receptor-associated factor 4 (TRAF4) and TRAF6 in immune cells and transgenic mice are emerging. Although it has been found that TRAF4 and TRAF6 share the same TRAF binding sites, comprehensive study of TRAF4 and TRAF6 in inflammatory bowel disease (IBD) is still lacking. This paper shows similar and different expression patterns of TRAF4 and TRAF6 in patients with IBD. The results indicate that TRAF4 and TRAF6 are overexpressed in IBD. TRAF4 and TRAF6 play different roles in the pathogenesis of IBD. Moreover, TRAF4 may be an indicator of endoscopic disease activity of UC and TRAF6 preactivation can be detected in noninflamed colonic segments.

The mRNA level of the transforming growth factor β1 gene, but not the amount of the gene product, can be considered as a potential prognostic parameter in inflammatory bowel diseases in children

PURPOSE

Transforming growth factor β1 (TGF-β1) plays a role in cell proliferation and differentiation, and it can modulate immune response. In this work, we asked whether levels of either TGF-β1 or mRNA of the corresponding gene in plasma or tissue can be useful in diagnosing and/or monitoring of the clinical course of inflammatory bowel diseases (IBD).

METHODS

The study group consisted of 104 pediatric patients with IBD: 36 with Crohn's disease (CD) and 68 with ulcerative colitis (UC); 42 children represented the control group. TGF-β1 levels in plasma and intestinal mucosa were estimated by ELISA and immunohistochemistry (IHC), respectively. Levels of TGF-β1 mRNA were determined by reverse transcription and real-time PCR.

RESULTS

In patients with IBD, and in subgroups with CD and UC, no significant differences in the TGF-β1 level in plasma and tissue were found relative to the control group. These variables were not dependent on the stage of the disease, its activity or severity of endoscopic and histopathological findings. TGF-β1 mRNA levels were significantly higher in tissue samples withdrawn during the relapse of the disease than in those taken during the remission or in the control group. However, no correlation between TGF-β1 plasma levels and TGF-β1 mRNA amount in the intestinal mucosa was observed.

CONCLUSIONS

The TGF-β1 mRNA level, but not the amount of the gene product, was significantly increased in the pathologically changed tissue during the relapse of IBD. We suggest that this parameter might be considered as a potential prognostic value when assessing IBD in children.

Intracolonically administered adeno-associated virus-bone morphogenetic protein-7 ameliorates dextran sulphate sodium-induced acute colitis in rats

BACKGROUND

The current treatment of ulcerative colitis (UC) is less than ideal and has room for improvement. Bone morphogenetic protein-7 (BMP-7) exerts a protective effect on experimental UC. Hence, we considered that intracolonically (i.c.) administered adeno-associated virus (AAV) delivering BMP-7 might have therapeutic potential for UC.

METHODS

Recombinant AAV type 2 vectors carrying enhanced green fluorescence protein (AAV-EGFP), LacZ (AAV-LacZ) and BMP-7 (AAV-BMP-7) were generated. Bioluminescence imaging, β-galactosidase assay and western blotting were applied to determine the colonic expression of EGFP, LacZ and BMP-7, respectively, after i.c. administration of the AAVs. Disease activity index (DAI) was observed daily during the 7 days of dextran sulphate sodium (DSS) treatment initiated 4 days after i.c. AAV-BMP-7, AAV-LacZ or phosphate-buffered saline. The colonic pathological morphology, mucosal myeloperoxidase (MPO) activity, malondialdehyde content, superoxide dismutase activity and proliferating cell nuclear antigen were determined at the end of DSS treatment.

RESULTS

When i.c administered to rats, AAV could efficiently transduce the colonic mucosa. Enema with AAV-BMP-7 significantly ameliorated DSS-induced colitis as indicated by reduced DAI, decreased macroscopic and histological scores and declined MPO activity compared to the controls. Furthermore i.c. AAV-BMP-7 significantly prevented oxidant damage and attenuated complementary mucosal cell proliferation in the DSS-treated rat colons.

CONCLUSIONS

Our data demonstrate that i.c. administration of AAV-BMP-7 efficiently mediates the ectopic BMP-7 expression in rat colon and further ameliorates DSS-induced UC in rats, suggesting that i.c. AAV-BMP-7 has the potential to be developed into an alternative therapeutic measure for the treatment of UC.

Increased presence of effector lymphocytes during Helicobacter hepaticus-induced colitis

AIM: To identify and characterize drosophila mothers against decapentaplegic (SMAD)3-dependent changes in immune cell populations following infection with Helicobacter hepaticus (H. hepaticus).

METHODS: SMAD3^-/- (n = 19) and colitis-resistant SMAD3^+/- (n = 24) mice (8-10 wk of age) were infected with H. hepaticus and changes in immune cell populations [T lymphocytes, natural killer (NK) cells, T regulatory cells] were measured in the spleen and mesenteric lymph nodes (MsLNs) at 0 d, 3 d, 7 d and 28 d post-infection using flow cytometry. Genotype-dependent changes in T lymphocytes and granzyme B⁺ cells were also assessed after 28 d in proximal colon tissue using immunohistochemistry.

RESULTS: As previously observed, SMAD3^-/-, but not SMAD3^+/- mice, developed colitis, peaking at 4 wk post-infection. No significant changes in T cell subsets were observed in the spleen or in the MsLNs between genotypes at any time point. However, CD4⁺ and CD8⁺/CD62L^lo cells, an effector T lymphocyte population, as well as NK cells (NKp46/DX5⁺) were significantly higher in the MsLNs of SMAD3^-/- mice at 7 d and 28 d post-infection. In the colon, a higher number of CD3⁺ cells were present in SMAD3^-/- compared to SMAD3^+/– mice at baseline, which did not significantly change during infection. However, the number of granzyme B⁺ cells, a marker of cytolytic lymphocytes, significantly increased in SMAD3^-/- mice 28 d post-infection compared to both SMAD3^+/- mice and to baseline values. This was consistent with more severe colitis development in these animals.

CONCLUSION: Data suggest that defects in SMAD3 signaling increase susceptibility to H. hepaticus-induced colitis through aberrant activation and/or dysregulation of effector lymphocytes.

Transforming growth factor beta 1 induces tight junction disruptions and loss of transepithelial resistance across porcine vas deferens epithelial cells

Epithelial cells lining the male excurrent duct contribute to male fertility by employing a number of physiological mechanisms that generate a luminal microenvironment conducive to spermatozoa maturation and storage. Among these mechanisms, male duct epithelia establish intercellular tight junctions that constitute a barrier to paracellular diffusion of water, solutes, large molecules, and cells. Mechanisms regulating the male duct epithelial barrier remain unidentified. Transforming growth factor beta (TGFB) is a regulatory cytokine present in high concentrations in human semen. This study examined whether TGFB has any effects on epithelial function exhibited by primary cultures of porcine vas deferens epithelia. TGFB1 exposure caused a 70%-99% decrease in basal transepithelial electrical resistance (R(TE), a sensitive indicator of barrier integrity), while a significant decrease in anion secretory response to forskolin was detected at the highest levels of TGFB1 exposure employed. SB431542, a selective TGFB receptor I (TGFBR1) inhibitor, prevented decreases in barrier function. Results also demonstrated that TGFB1 exposure modifies the distribution pattern of tight junction proteins occludin and claudin 7. TGFBR1 is localized at the apical border of the native porcine vas deferens epithelium. Pharmacological inhibition of mitogen-activated protein kinase (MAPK) 11 (also known as p38-MAPK) did not alter the effect of TGFB1 on R(TE) significantly. These data suggest that epithelia lining the vas deferens are subject to disruptions in the physical barrier if active TGFB becomes bioavailable in the luminal fluid, which might be expected to compromise fertility.

Colonic expression of Runx3 protein and TGF-β(1) and their correlation in patients with irritable bowel syndrome

OBJECTIVE

To investigate the role of Runx3 protein and TGF-β(1) in the pathogenesis of irritable bowel syndrome (IBS), as well as the correlation of these two proteins.

METHODS

Colonic tissue was collected from patients with IBS and normal persons. The colonic expression of Runx3 protein and TGF-β(1) was detected with immunohistochemistry method. Semi-quantitative analysis was used to evaluate the staining degree of these two proteins.

RESULTS

Compared with their counterparts, patients with IBS did not show any changes in the colonic expression of Runx3 protein and TGF-β(1) (P>0.05). Interestingly, there was a significant correlation between Runx3 protein and TGF-β(1) in patients with IBS(P<0.05).

CONCLUSIONS

The role of Runx3 protein and TGF-β(1) in the pathogenesis of IBS remains to be further studied.

Iridoid glycosides fraction of Folium syringae leaves modulates NF-κB signal pathway and intestinal epithelial cells apoptosis in experimental colitis

BACKGROUND AND AIMS

Iridoid glycosides (IG), the major active fraction of F. syringae leaves has been demonstrated to have strong anti-inflammatory properties to ulcerative colitis (UC) in our previous study. The aim of this study was to investigate whether IG modulates the inflammatory response in experimental colitis at the level of NF-κB signal pathway and epithelial cell apoptosis.

METHODS

UC in rats was induced by administration with dextran sulfate sodium (DSS) in drinking water. The inflammatory damage was assessed by disease activity index (DAI), macroscopic findings, histology and myeloperoxidase (MPO) activity. The effect of IG on pro-inflammatory cytokines TNF-α, IL-8, COX-2 and regulatory peptide TGF-β1 was measured. Epithelial cell apoptosis and the protein and mRNA expressions of Fas/FasL, Bcl-2/Bax, caspase-3, NF-κB p65, IκBα, p-IκBα and IKKβ were detected by TUNEL method, immunohistochemistry, Western blotting and real-time quantitative PCR, respectively.

RESULTS

IG significantly ameliorated macroscopic damage and histological changes, reduced the activity of MPO, and strongly inhibited epithelial cell apoptosis. Moreover, IG markedly depressed TNF-α, IL-8, COX-2 and TGF-β1 levels in the colon tissues in a dose-dependent manner. Furthermore, IG significantly blocked of NF-κB signaling by inhibiting IκBα phosphorylation/degradation and IKKβ activity, down-regulated the protein and mRNA expressions of Fas/FasL, Bax and caspase-3, and activated Bcl-2 in intestinal epithelial cells.

CONCLUSIONS

These results demonstrated for the first time that IG possessed marked protective effects on experimental colitis through inhibition of epithelial cell apoptosis and blockade of NF-κB signal pathway.

Intestinal tissue kallikrein-kinin system in inflammatory bowel disease

Tissue kallikrein cleaves kininogens to release kinins. Kinins mediate inflammation by activating constitutive bradykinin receptor-2 (BR2), which are rapidly desensitized, and induced by inflammatory cytokines bradykinin receptor-1 (BR1), resistant to desensitization. Intestinal tissue kallikrein (ITK) may hydrolyze growth factors and peptides, whereas kinins are responsible for capillary permeability, pain, synthesis of cytokines, and adhesion molecule-neutrophil cascade. Our and others results have demonstrated ITK in intestinal goblet cells and its release into interstitial space during inflammation. Kallistatin, an inhibitor of ITK, has been shown in epithelial and goblet cells, and was decreased in inflamed intestine as well as in plasma compared with noninflammatory controls. BR1 was upregulated in patients with inflammatory bowel disease (IBD), and it has expressed in an apical part of enterocytes in inflamed intestine, but in the basal part in normal intestine. ITK and BR1 were visualized in macrophages forming granuloma in Crohn's disease. In animal studies BR2 blockade decreased intestinal contraction, but had limited effect on inflammatory lesions. BR1 was found to be upregulated in animal inflamed intestine, in part dependent on tumor necrosis factor alpha (TNF-α). A selective BR1 receptor antagonist decreased morphological and biochemical features of experimental intestinal inflammation. Both BR1 and BR2 mediate epithelial ion transport that leads to secretory diarrhea. The upregulation of BR1 in inflamed intestine provides a structural basis for the kinins function, suggesting that a selective BR1 antagonist may have potential in therapeutic trial of IBD patients.

Expression, localization and systemic concentration of vascular endothelial growth factor (VEGF) and its receptors in patients with ulcerative colitis

Vascular endothelial grow factor (VEGF) promotes angiogenesis by activating the specific receptors KDR and Flt-1. We investigate the expression of genes encoding VEGF and its receptors KDR and Flt- 1 by RT-QPCR reaction using Quanti Tect SYBR Green RT-PCR in patients with active and inactive ulcerative colitis (UC) and control subjects. The localization and level of VEGF protein and its receptors protein in intestinal tissue were estimated by immunohistochemistry. VEGF concentration in serum and plasma was determined by ELISA. We found a significant increase of VEGF gene expression and increase expression of genes encoding receptor Flt-1 in patients with active UC when compared with controls, but KDR was present in trace amount. VEGF and Flt-1 proteins were colocalized in enterocytes as well as in endothelium and muscularis layer of the intestine. The specific staining reaction for VEGF protein as well as for Flt-1 protein was significantly higher in active UC compared with controls. Serum level of VEGF was significantly higher in active UC patients as compared with inactive UC patients as well as with controls. The plasma VEGF level was found to be significantly higher in active UC patients as compared with controls. The increase of gene expression as well as protein level for VEGF and its receptor in UC - inflamed colon, and VEGF action via Flt-1 receptor may have a functional role in UC. Increased VEGF levels in both serum and plasma in active UC patients may reflect VEGF overexpression in intestinal inflammatory tissue.

Molecular basis of anti-inflammatory action of platelet-rich plasma on human chondrocytes: mechanisms of NF-κB inhibition via HGF

Loss of articular cartilage through injury or disease presents major clinical challenges also because cartilage has very poor regenerative capacity, giving rise to the development of biological approaches. As autologous blood product, platelet-rich plasma (PRP) provides a promising alternative to surgery by promoting safe and natural healing. Here we tested the possibility that PRP might be effective as an anti-inflammatory agent, providing an attractive basis for regeneration of articular cartilage, and two principal observations were done. First, activated PRP in chondrocytes reduced the transactivating activity of NF-κB, critical regulator of the inflammatory process, and decreased the expression of COX-2 and CXCR4 target genes. By analyzing a panel of cytokines with different biological significance, in activated PRP we observed increases in hepatocyte growth factor (HGF), interleukin-4 and tumor necrosis factor-α (TNF-α). HGF and TNF-α, by disrupting NF-κB-transactivating activity, were important for the anti-inflammatory function of activated PRP. The key molecular mechanisms involved in PRP-inhibitory effects on NF-κB activity were for HGF the enhanced cellular IkBα expression, that contributed to NF-κB-p65 subunit retention in the cytosol and nucleo-cytoplasmic shuttling, and for TNF-α the p50/50 DNA-binding causing inhibition of target-gene expression. Second, activated PRP in U937-monocytic cells reduced chemotaxis by inhibiting chemokine transactivation and CXCR4-receptor expression, thus possibly controlling local inflammation in cartilage. In conclusion, activated PRP is a promising biological therapeutic agent, as a scaffold in micro-invasive articular cartilage regeneration, not only for its content of proliferative/differentiative growth factors, but also for the presence of anti-inflammatory agents including HGF.

Modulation of factors affecting optic nerve head astrocyte migration

PURPOSE

The authors investigated the role of myosin light chain kinase (MYLK) and transforming growth factor beta (TGFbeta) receptor pathways in optic nerve head (ONH) astrocyte migration. They further investigated how the expression of these genes is altered by elevated hydrostatic pressure (HP).

METHODS

PCR was used to determine the isoforms of MYLK expressed in ONH astrocytes. siRNAs against MYLK (all isoforms) and TGFbeta receptor 2 (TGFBR2) were prepared and tested for effects on the migration of cultured ONH astrocytes. Finally, the effects of elevated HP (24-96 hours) on the expression of MYLK isoforms and selected TGFbeta pathway components were measured.

RESULTS

Multiple isoforms of MYLK are present in ONH astrocytes from Caucasian (CA) and African American (AA) donors. Both populations express the short form (MYLK-130) and the long form (MYLK-210) of MYLK and a splicing variant within MYLK-210. MYLK-directed siRNA decreased MYLK expression and cell migration compared with control siRNA. siRNA directed against TGFbeta receptor 2 also decreased cell migration compared with control and decreased extracellular matrix genes regulated by TGFbeta signaling. Elevated HP increased the expression of MYLK-130 and MYLK-210 in both populations of astrocytes. However, TGFbeta2 was uniquely upregulated by exposure to elevated HP in CA compared with AA astrocytes.

CONCLUSIONS

Differential expression of TGFbeta pathway genes and MYLK isoforms observed in populations of glaucomatous astrocytes applies to the elevated HP model system. MYLK may be a new target for intervention in glaucoma to alter reactive astrocyte migration in the ONH.