Elevated serum hepatocyte growth factor in children and young adults with inflammatory bowel disease

Serum proteomic profiling at diagnosis predicts clinical course, and need for intensification of treatment in inflammatory bowel disease

BACKGROUND

Success in personalized medicine in complex disease is critically dependent on biomarker discovery. We profiled serum proteins using a novel proximity extension assay [PEA] to identify diagnostic and prognostic biomarkers in inflammatory bowel disease [IBD].

METHODS

We conducted a prospective case-control study in an inception cohort of 552 patients [328 IBD, 224 non-IBD], profiling proteins recruited across six centres. Treatment escalation was characterized by the need for biological agents or surgery after initial disease remission. Nested leave-one-out cross-validation was used to examine the performance of diagnostic and prognostic proteins.

RESULTS

A total of 66 serum proteins differentiated IBD from symptomatic non-IBD controls, including matrix metallopeptidase-12 [MMP-12; Holm-adjusted p = 4.1 × 10-23] and oncostatin-M [OSM; p = 3.7 × 10-16]. Nine of these proteins are associated with cis-germline variation [59 independent single nucleotide polymorphisms]. Fifteen proteins, all members of tumour necrosis factor-independent pathways including interleukin-1 (IL-1) and OSM, predicted escalation, over a median follow-up of 518 [interquartile range 224-756] days. Nested cross-validation of the entire data set allowed characterization of five-protein models [96% comprising five core proteins ITGAV, EpCAM, IL18, SLAMF7 and IL8], which define a high-risk subgroup in IBD [hazard ratio 3.90, confidence interval: 2.43-6.26], or allowed distinct two- and three-protein models for ulcerative colitis and Crohn's disease respectively.

CONCLUSION

We have characterized a simple oligo-protein panel that has the potential to identify IBD from symptomatic controls and to predict future disease course. Further prospective work is required to validate our findings.

Elevated serum level of hepatocyte growth factor predicts development of new syndesmophytes in men with ankylosing spondylitis

Objectives

To study baseline serum hepatocyte growth factor (s-HGF) as a predictor of spinal radiographic progression overall and by sex and to analyse factors correlated to changes in s-HGF in patients with AS.

Methods

At baseline and the 5-year follow-up, s-HGF was analysed with ELISA. Spinal radiographs were graded according to modified Stoke Ankylosing Spondylitis Spinal Score. Radiographic progression was defined as ≥2 modified Stoke Ankylosing Spondylitis Spinal Score units/5 years or development of ≥1 syndesmophyte. Logistic regression analyses were used.

Results

Of 204 baseline participants, 163 (80%) completed all examinations at the 5-year follow-up (54% men). Baseline s-HGF was significantly higher in men who developed ≥1 syndesmophyte compared with non-progressors, median (interquartile range) baseline s-HGF 1551 (1449–1898) vs 1436 (1200–1569) pg/ml, P = 0.003. The calculated optimal cut-off point for baseline s-HGF ≥1520 pg/ml showed a sensitivity of 70%, a specificity of 69% and univariate odds radio (95% CI) of 5.25 (1.69, 14.10) as predictor of development of ≥1 new syndesmophyte in men. Baseline s-HGF ≥1520 pg/ml remained significantly associated with development of ≥1 new syndesmophyte in men in an analysis adjusted for the baseline variables age, smoking, presence of syndesmophytes and CRP, odds radio 3.97 (1.36, 11.60). In women, no association with HGF and radiographic progression was found. Changes in s-HGF were positively correlated with changes in ESR and CRP.

Conclusion

In this prospective cohort study elevated s-HGF was shown to be associated with development of new syndesmophytes in men with AS.

Effects of Recombinant Angiogenin on Collagen Fiber Formation and Angiogenesis in the Dermis of Wistar Rats

Purpose

The purpose of this study was to assess the capability of recombinant angiogenin isolated from Pichia pastoris yeasts to stimulate regenerative processes in the dermis of experimental animals.

Patients and Methods

Wistar rats were administered with recombinant angiogenin intracutaneously. Morphological examination of the skin and the assessment of the proliferative activity of the epidermal cells were carried out. Additionally, cytokine production by human whole blood cells exposed to angiogenin was analyzed ex vivo.

Results

Administration of angiogenin stimulates collagen fiber formation and angiogenesis. This stimulation is tightly associated with an increase in the number of fibroblasts, an increased numerical density of dermal blood vessels and an increased density of collagen fibers; also, it activates the proliferation of basal cells. Angiogenin induces the production of MCP, IL-8, IL-6, IL-1β, TNF-α, IL-10, TGF-β, and VEGF by blood cells.

Conclusion

The results obtained indicate a broad spectrum of actions of recombinant angiogenin during regenerative processes in the basal layer of the dermis.

Neutrophilic HGF-MET Signalling Exacerbates Intestinal Inflammation

BACKGROUND AND AIMS

Ulcerative colitis [UC] is associated with excessive neutrophil infiltration and collateral tissue damage, but the link is not yet completely understood. Since c-MET receptor tyrosine kinase [MET] is required for neutrophil chemoattraction and cytotoxicity in response to its ligand hepatocyte growth factor [HGF], we aimed to identify the function of HGF-MET signalling in neutrophils in UC patients and in mice during intestinal inflammation.

METHODS

Serum and colonic biopsies from healthy controls and UC patients with active [Mayo endoscopic subscore 2-3] and inactive [Mayo endoscopic subscore 0-1] disease were collected to assess the level of serum and colonic HGF. Disease progression and immune cell infiltration were assessed during dextran sodium sulphate [DSS] colitis in wild-type and MRP8-Cre MET-LoxP mice.

RESULTS

Increased mucosal HGF expression was detected in patients with active UC, and in mice during the inflammatory phase of DSS colitis. Similarly, serum HGF was significantly increased in active UC patients and positively correlated with C-reactive protein and blood neutrophil counts. Flow cytometric analysis also demonstrated an upregulation of colonic MET+ neutrophils during DSS colitis. Genetic ablation of MET in neutrophils reduced the severity of DSS-induced colitis. Concomitantly, there was a decreased number of TH17 cells, which could be due to a decreased production of IL-1β by MET-deficient neutrophils.

CONCLUSIONS

These data highlight the central role of neutrophilic HGF-MET signalling in exacerbating damage during intestinal inflammation. Hence, selective blockade of this pathway in neutrophils could be considered as a novel therapeutic approach in UC.

Experimental and Clinical Evidence of Endothelial Dysfunction in Inflammatory Bowel Disease

The endothelium has a crucial role in proper hemodynamics. Inflammatory bowel disease (IBD) is mainly a chronic inflammatory condition of the gastrointestinal tract. However, considerable evidence points to high cardiovascular risk in patients with IBD. This review positions the basic mechanisms of endothelial dysfunction in the IBD setting (both clinical and experimental). Furthermore, we review the main effects of drugs used to treat IBD in endothelial (dys)function. Moreover, we leave challenging points for enlarging the therapeutic arsenal for IBD with new or repurposed drugs that target endothelial dysfunction besides inflammation.

Hepatocyte growth factor is a potential biomarker for osteoproliferation and osteoporosis in ankylosing spondylitis

We explored relations between serum hepatocyte growth factor (HGF), disease activity, osteoproliferation, and bone mineral density (BMD) in ankylosing spondylitis (AS), in comparison with healthy controls. HGF was increased especially in male AS patients and smokers and associated with both lower BMD and more chronic radiographic changes in the spine.

INTRODUCTION

Ankylosing spondylitis (AS) is characterized by both osteoproliferation and increased bone loss. Biomarkers are requested to predict the processes. The aims of this study were to compare serum levels of hepatocyte growth factor (HGF), matrix metalloproteinase-3 (MMP-3), and vascular endothelial growth factor (VEGF) in AS patients with healthy controls (HC) and to explore the associations with disease activity, osteoproliferation, and bone mineral density (BMD).

METHODS

Serum from AS patients (modified NY-criteria) and HC was analyzed for HGF, MMP-3, and VEGF with ELISA. Disease activity parameters were collected. Osteoproliferation was assessed with modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and BMD was measured in femoral neck.

RESULTS

Totally, 204 AS patients and 80 sex and age matched HC were included. Serum HGF was higher in the AS patients compared with the HC, whereas serum MMP-3 and VEGF were not. Serum HGF was also higher in smokers and in the male AS patients positively correlated with age, BASMI, and mSASSS, and negatively correlated with BMD. The biomarkers were all positively associated with ESR, CRP, and WBC. In multiple linear regression analysis serum HGF remained associated with higher mSASSS and lower BMD, after adjusting for age, sex, CRP, smoking, and body mass index.

CONCLUSIONS

Serum HGF was increased in male AS patients and associated with higher mSASSS and lower BMD. In addition, serum HGF was positively associated with risk factors for osteoproliferation such as age, CRP and smoking. HGF could be a potential biomarker of importance for the bone metabolism in AS.

TRIAL REGISTRATION

NCT00858819.

Systemic Inflammatory Responses in Ulcerative Colitis Patients and Clostridium difficile Infection

BACKGROUND/AIMS

Finding differences in systemic inflammatory response in ulcerative colitis (UC), UC with Clostridium difficile infection (CDI), and CDI could lead to a better ability to differentiate between UC with symptomatic CDI and UC with C. difficile colonization, and could identify specific inflammatory pathways for UC or CDI, which could be therapeutic targets.

METHODS

We prospectively collected sera from symptomatic UC patients whose stools were tested for toxigenic C. difficile, and from CDI patients who did not have UC (CDI-noUC). The UC patients with positive tests (UC-CDI) were further categorized into responders to CDI treatment (UC-CDI-R) and non-responders (UC-CDI-NR). We compared serum inflammatory mediators among groups using unadjusted and adjusted multivariable statistics.

RESULTS

We included 117 UC [27 UC-CDI, 90 UC without CDI (UC-noCDI)] and 16 CDI-noUC patients. Principal component analysis (PCA) did not reveal significant differences either between UC-CDI and UC-noCDI groups, or between UC-CDI-R and UC-CDI-NR groups. In contrast, the PCA showed significant separation between the UC and CDI-noUC groups (P = 0.002). In these two groups, hepatocyte growth factor (HGF) and chemokine (C-C motif) ligand 2 (CCL2) levels were significantly lower and IL-23 levels were higher in UC patients in multivariable analyses. The model to distinguish UC from CDI including IL-23, HGF, CCL2, age, gender, and HGB had an AuROC of 0.93.

CONCLUSION

Inflammatory profiles could not distinguish UC-CDI from UC-noCDI, and UC-CDI-R from UC-CDI-NR. However, the UC and CDI-noUC groups were significantly different. Future work should examine whether therapeutic agents inhibiting IL-23 or stimulating HGF can treat UC.

Immunological profiling of patients with ulcerative colitis leads to identification of two inflammatory conditions and CD1a as a disease marker

Background

Conventional approaches to understand mechanisms underlying the development of pathological manifestations in ulcerative colitis (UC) mostly rely on identification of certain cell types and cytokines followed by verification of their roles in vitro and in vivo. In light of the highly dynamic processes in UC, requiring the cross talk of immune cells, epithelial-, endothelial-, muscle cells and fibrocytes, this approach might neglect temporal and spatial connectivity of individually differing inflammatory responses.

Methods

We undertook a more holistic approach whereby we designed a flow cytometric analysis- and ELISA panel and determined the immunological profiles of UC patients in comparison to Non UC donors. This panel consisted of B-cells, T-cells, macrophages, monocytes, NK- and NK T-cells and subtypes thereof, the cytokines TGFß1 and HGF, the chemokine TARC and periostin. Blood was collected from 41 UC patients and 30 non-UC donors. Isolated PBMC were subjected to flow cytometric analysis and sera were analyzed by ELISA. Data were analysed by cluster- and correlation analysis. To corroborate that the identified cells reflected the inflammatory condition in the colon of UC patients, leucocytes were isolated from colons of UC patients and subjected to the same flow cytometric analysis.

Results

Immunological profiling followed by cluster- and correlation analysis led to the identification of two inflammatory conditions: An ‘acute’ condition characterized by adaptive immune cells as plasma cells,  TSLPR expressing CD11b+ macrophages, CD64 and CCR2 expressing CD14+ monocytes, HGF and TARC and a ‘remodeling’ condition signified by NK T-cells and TLSPR expressing CD14+ monocytes, TGFß1 and periostin. ROC analysis identified TARC and TGFß1 as biological markers with high potential to discriminate between these two conditions (Δ = −6687.72 ng/ml; p = 1E−04; AUC = 0.87). In addition, CD1a+ CD11b+ macrophages (Δ = 17.73% CD1a+ CD11b+; p = 5E−04; AUC = 0.86) and CD1a+ CD14+ monocytes (Δ = 20.35; p = 0.02, AUC = 0.75) were identified as markers with high potential to discriminate between UC and Non UC donors. CD1a+ CD11b+ macrophages and NK T-cells were found to be significantly increased in inflamed colons of UC patients as compared to non-UC control samples (p = 0.02).

Conclusions

Immunological profiling of UC patients might improve our understanding of the pathology underlying individual manifestations and phases of the disease. This might lead to the development of novel diagnostics and therapeutic interventions adapted to individual needs and different phases of the disease. In addition, it might result in stratification of patients for clinical trials.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-1048-9) contains supplementary material, which is available to authorized users.

Angiogenesis in Inflammatory Bowel Disease

Angiogenesis is an important component of pathogenesis of inflammatory bowel disease (IBD). Chronic inflammation and angiogenesis are two closely related processes. Chronic intestinal inflammation is dependent on angiogenesis and this angiogenesis is modulated by immune system in IBD. Angiogenesis is a very complex process which includes multiple cell types, growth factors, cytokines, adhesion molecules, and signal transduction. Lymphangiogenesis is a new research area in the pathogenesis of IBD. While angiogenesis supports inflammation via leukocyte migration, carrying oxygen and nutrients, on the other hand, it has a major role in wound healing. Angiogenic molecules look like perfect targets for the treatment of IBD, but they have risk for serious side effects because of their nature.

Hepatocyte growth factor: A regulator of inflammation and autoimmunity

Hepatocyte growth factor (HGF) is a pleiotropic cytokine that has been extensively studied over several decades, but was only recently recognized as a key player in mediating protection of many types of inflammatory and autoimmune diseases. HGF was reported to prevent and attenuate disease progression by influencing multiple pathophysiological processes involved in inflammatory and immune response, including cell migration, maturation, cytokine production, antigen presentation, and T cell effector function. In this review, we discuss the actions and mechanisms of HGF in inflammation and immunity and the therapeutic potential of this factor for the treatment of inflammatory and autoimmune diseases.

Maintenance of optimal vitamin D status in children and adolescents with inflammatory bowel disease: a randomized clinical trial comparing two regimens

CONTEXT

Vitamin D promotes bone health and regulates the immune system, both important actions for pediatric patients with inflammatory bowel disease (IBD). The supplementation dose that would maintain optimal serum 25-hydroxyvitamin D concentration (25OHD ≥ 32 ng/mL) is unknown.

OBJECTIVE

The objective of the study was to compare two supplementation regimens' efficacy and safety in maintaining optimal 25OHD in children with IBD.

DESIGN

This was a randomized, not blinded, controlled trial.

SETTING

The trial was conducted in the Boston Children's Hospital Clinical and Translational Study Unit.

PARTICIPANTS

Sixty-three patients, aged 8-18 years with IBD and baseline 25OHD greater than 20 ng/mL were enrolled; 48 completed the study, and one withdrew for adverse events.

INTERVENTION

Arm A received 400 IU of oral vitamin D2 daily (n = 32). Arm B received 1000 IU daily in the summer/fall and 2000 IU in the winter/spring (n = 31).

MAIN OUTCOME

The main outcome was the probability of maintaining 25OHD of 32 ng/mL or greater in all trimonthly visits for 12 months.

RESULTS

Three participants in arm A (9.4%) and three in arm B (9.7%) achieved the primary outcome (P = .97). The incidence of adverse events, all minor, did not differ. More participants in arm A developed C-reactive protein level of 1 mg/dL or greater (31% vs 10%, P = .04) and IL-6 greater than 3 pg/mL (54% vs 27%, P = .05).

CONCLUSIONS

Daily oral vitamin D2 doses up to 2000 IU were inadequate to maintain optimal 25OHD but were well tolerated. The finding of lower incidence of elevated inflammatory markers and cytokines among participants receiving higher vitamin D2 doses merits further study.

Association between Hepatocyte Growth Factor (HGF) Gene Polymorphisms and Serum HGF Levels in Patients with Rheumatoid Arthritis

OBJECTIVE

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by proliferation and insufficient apoptosis of synovial cell, inflammatory cell infiltration, angiogenesis, and destruction of joints. Hepatocyte growth factor (HGF) has many functions, such as regulation of inflammation, angiogenesis, and inhibition of apoptosis. The purpose of this study was to investigate the association between intron 13 C/A and intron 14 T/C HGF gene polymorphisms and serum HGF levels in patients with RA.

MATERIALS AND METHODS

100 patients with RA and 123 healthy controls were included in this study. Serum HGF concentrations were measured using ELISA kit. Gene polymorphisms were determined by allelic discrimination analysis using the real-time PCR method.

RESULTS

HGF levels, frequency of AA genotype and A allele for intron 13 C/A polymorphism and frequency of CC genotype and C allele for intron 14 T/C polymorphism were increased in patients with RA compared to healthy controls. There was no overall associations between genotypes and serum HGF concentrations in both patient and control groups.

CONCLUSION

Our results indicate that HGF protein and gene may play an important role in the etiopathogenesis of RA. However, further studies are required for a better understanding of mechanisms related to the disease process.

Intramuscular injection of adenoviral hepatocyte growth factor at a distal site ameliorates dextran sodium sulfate-induced colitis in mice

Inflammatory bowel disease (IBD) severely affects the quality of life of patients. At present, there is no clinical solution for this condition; therefore, there is a need for innovative therapies for IBD. Hepatocyte growth factor (HGF) exerts various biological activities in various organs. However, a clinically applicable and effective HGF-based therapy for IBD has yet to be developed. In this study, we examined the therapeutic effect of injecting an adenoviral vector encoding the human HGF gene (Ad.HGF) into the hindlimbs of mice with dextran sodium sulfate (DSS)-induced colitis. Plasma levels of circulating human HGF (hHGF) were measured in injected mice. The results showed that weight loss and colon shortening were significantly lower in Ad.HGF-infected mice as compared to control (Ad.LacZ-infected) colitic mice. Additionally, inflammation and crypt scores were significantly reduced in the entire length of the colon, particularly in the distal section. This therapeutic effect was associated with increased cell proliferation and an antiapoptotic effect, as well as a reduction in the number of CD4+ cells and a decreased CD4/CD8 ratio. The levels of inflammatory, as well as Th1 and Th2 cytokines were higher in Ad.HGF-infected mice as compared to the control colitic mice. Thus, systemically circulating hHGF protein, produced by an adenovirally transduced hHGF gene introduced at distal sites in the limbs, significantly ameliorated DSS-induced colitis by promoting cell proliferation (i.e., regeneration), preventing apoptosis, and immunomodulation. Owing to its clinical feasibility and potent therapeutic effects, this method may be developed into a clinical therapy for treating IBD.

Treatment of vitamin D insufficiency in children and adolescents with inflammatory bowel disease: a randomized clinical trial comparing three regimens

CONTEXT

Vitamin D insufficiency [serum 25-hydroxyvitamin D (25OHD) concentration less than 20 ng/ml] is prevalent among children with inflammatory bowel disease (IBD), and its treatment has not been studied.

OBJECTIVE

The aim of this study was to compare the efficacy and safety of three vitamin D repletion regimens.

DESIGN AND SETTING

We conducted a randomized, controlled clinical trial from November 2007 to June 2010 at the Clinical and Translational Study Unit of Children's Hospital Boston. The study was not blinded to participants and investigators.

PATIENTS

Eligibility criteria included diagnosis of IBD, age 5-21, and serum 25OHD concentration below 20 ng/ml. Seventy-one patients enrolled, 61 completed the trial, and two withdrew due to adverse events.

INTERVENTION

Patients received orally for 6 wk: vitamin D(2), 2,000 IU daily (arm A, control); vitamin D(3), 2,000 IU daily (arm B); vitamin D(2), 50,000 IU weekly (arm C); and an age-appropriate calcium supplement.

MAIN OUTCOME MEASURE

We measured the change in serum 25OHD concentration (Δ25OHD) (ng/ml). Secondary outcomes included change in serum intact PTH concentration (ΔPTH) (pg/ml) and the adverse event occurrence rate.

RESULTS

After 6 wk, Δ25OHD ± se was: 9.3 ± 1.8 (arm A); 16.4 ± 2.0 (arm B); 25.4 ± 2.5 (arm C); P (A vs. C) = 0.0004; P (A vs. B) = 0.03. ΔPTH ± SE was -5.6 ± 5.5 (arm A); -0.1 ± 4.2 (arm B); -4.4 ± 3.9 (arm C); P = 0.57. No participant experienced hypercalcemia or hyperphosphatemia, and the prevalence of hypercalciuria did not differ among arms at follow-up.

CONCLUSIONS

Oral doses of 2,000 IU vitamin D(3) daily and 50,000 IU vitamin D(2) weekly for 6 wk are superior to 2,000 IU vitamin D(2) daily for 6 wk in raising serum 25OHD concentration and are well-tolerated among children and adolescents with IBD. The change in serum PTH concentration did not differ among arms.

Improvement of sepsis by hepatocyte growth factor, an anti-inflammatory regulator: emerging insights and therapeutic potential

Sepsis-induced multiple organ failure (MOF) is the most frequent lethal disease in intensive care units. Thus, it is important to elucidate the self-defensive mechanisms of sepsis-induced MOF. Hepatocyte growth factor (HGF) is now recognized as an organotrophic factor, which is essential for organogenesis during embryonic growth and regeneration in adulthood. HGF production is enhanced in response to infectious challenges, but the increase in endogenous HGF levels is transient and insufficient, with a time lag between tissue injuries and HGF upregulation, during progression of septic MOF. Thus, administration of active-formed HGF might be a new candidate for therapeutic development of MOF. HGF has an ability to target endotoxin-challenged macrophages and inhibits the upregulation of inflammatory cytokines through nuclear factor-κB-inactivated mechanisms. HGF also targets the endothelium and epithelium of various organs to suppress local inflammation, coagulation, and apoptotic death. This paper summarizes the novel mechanisms of HGF for attenuating sepsis-related pathological conditions with a focus on sepsis-induced MOF.

Efficacy and harms of nasal calcitonin in improving bone density in young patients with inflammatory bowel disease: a randomized, placebo-controlled, double-blind trial

OBJECTIVES

There are very few published studies of agents having the potential to improve bone health in children with inflammatory bowel disease (IBD). The objective of this study was to establish the efficacy and safety of intranasal calcitonin in improving bone mineral density (BMD) in young patients with IBD and to define additional factors that impact bone mineral accrual.

METHODS

We conducted a randomized, placebo-controlled, double-blind clinical trial in 63 participants, ages 8-21 years, with a spinal BMD Z-score ≤ -1.0 s.d. measured by dual energy X-ray absorptiometry. Subjects were randomized to 200 IU intranasal calcitonin (n=31) or placebo (n=32) daily. All received age-appropriate calcium and vitamin D supplementation. Subsequent BMD measurements were obtained at 9 and 18 months.

RESULTS

Intranasal calcitonin was well tolerated. Adverse event frequency was similar in both treatment groups, and such events were primarily minor, reversible, and limited to the upper respiratory tract. The BMD Z-score change documented at screening and 9 months and screening and 18 months did not differ between the two therapeutic arms. In participants with Crohn's disease, the spinal BMD Z-score improved between screening and 9 months (change in spine BMD Z-score (ΔZSBMD)(9-0)) in the calcitonin group (ΔZSBMD(9-0)(calcitonin)=0.21 (0.37), ΔZSBMD(9-0)(placebo)=-0.15 (0.5), P=0.02); however, this was only a secondary subgroup analysis. Bone mineral accrual rate during the trial did not lead to normalization of BMD Z-score in this cohort. Factors favoring higher bone mineral accrual rate were lower baseline BMD and higher baseline body mass index Z-score, improvement in height Z-score, higher serum albumin, hematocrit and iron concentration, and more hours of weekly weight-bearing activity. Factors associated with lower bone mineral accrual rate were more severe disease-as indicated by elevated inflammatory markers, need for surgery, hospitalization, and the use of immunomodulators-and higher daily caffeine intake.

CONCLUSIONS

Intranasal calcitonin is well tolerated but does not offer a long-term advantage in youth with IBD and decreased BMD. Bone mineral accrual rate remains compromised in youth with IBD and low BMD raising concerns for long-term bone health outcomes. Improvement in nutritional status, catch-up linear growth, control of inflammation, increase in weight-bearing activity, and lower daily caffeine intake may be helpful in restoring bone density in children with IBD and low BMD.

Role of growth factors in the development of lymphangiogenesis driven by inflammatory bowel disease: a review

Studies on angiogenesis and lymphangiogenesis have gained special relevance in research into factors potentially influencing the pathogenesis and course of inflammatory bowel disease (IBD). The results of the few existing studies on the distribution and density of lymphatic vessels and blood vessels in the context of IBD are controversial. Studies using the specific lymphatic marker podoplanin have revealed a significantly large number of lymphatic vessels in the colonic mucosa of patients with ulcerative colitis and Crohn's disease (compared to patients with normal mucosa), whereas other authors have found no significant differences. However, the role of vascular endothelial growth factor (VEGF) tyrosine-kinase receptor 3 (VEGFR-3) in the onset of IBD has not been analyzed. In recent years new biochemical, molecular, and immunohistochemical studies indicate that several families of growth factors, such as the VEGF family and their receptors, fibroblast growth factor-2, platelet-derived growth factor-BB, hepatocyte growth factor, the angiopoietin system, and integrins may play an important role in the onset of IBD. To date, no comparative studies have analyzed these growth factors and specific lymphatic markers. We examine how growth factors are involved in the development of pathological lymphangiogenesis in patients with IBD and determine whether they play a crucial role in disease exacerbation.

Angiogenesis in inflammatory bowel disease

Both ulcerative colitis and Crohn's disease, the two major forms of inflammatory bowel diseases, are recognized, at the moment, as perplexing and challenging clinical entities, in which several molecules and cell types are implicated. Recent molecular evidence proposes the intestinal microvascular remodelling or angiogenesis, as a phenomenon implicated in the pathogenesis of these chronic inflammatory disorders, together with other proposed theories involved in the pathogenesis of inflammatory bowel diseases, such as genetic, microbacterial and immune factors. Intestinal damage is followed by a physiological angiogenesis, but the abnormal expression of pro- and anti-angiogenic molecules and the changes of vascular cell types could reflect a pathological vascular remodelling. Thus, the inflammation may be favoured and maintained by a pathological angiogenesis. A better understanding of the angiogenic process may facilitate the design of more effective therapies for chronic intestinal inflammation.

Hepatocyte growth factor promotes colonic epithelial regeneration via Akt signaling

Hepatocyte growth factor (HGF) can promote the regeneration of injured organs, including HGF gene therapy by electroporation (EP) for liver injury. In this study, we investigated the effect of HGF on dextran sulfate sodium-induced colitis and tried to clarify the regenerative mechanisms of colonic epithelial cells and the signaling pathway involved. Colitis was induced by dextran sulfate sodium in mice, together with HGF gene transfer by EP. On day 10, the colitis was evaluated histologically and by Western blot analysis. The colonic epithelial cell line MCE301 was exposed to HGF protein, and its proliferation and activated signaling pathway were analyzed. In vivo, the histological score improved and the number of Ki-67-positive epithelial cells increased in the HGF-treated mice compared with the controls. Western blot analysis showed enhanced expression of phospho-Akt in the HGF-treated mice compared with the controls. In vitro, HGF stimulated the proliferation of MCE301 cells. There was enhanced phospho-Akt expression for more than 48 h after HGF stimulation, although phospho-ERK1/2 was enhanced for only 10 min. LY-294002 or Akt small interfering RNA suppressed cell proliferation induced by HGF. Thus HGF induces the proliferation of colonic epithelial cells via the phosphatidylinositol 3-kinase/Akt signaling pathway. HGF gene therapy can attenuate acute colitis via epithelial cell proliferation through the PI3K/Akt pathway. These data suggested that HGF gene therapy by EP may be effective for the regeneration and repair of injured epithelial cells in inflammatory bowel disease.

[Vascular development in inflammatory bowel disease]

There are 4 major concepts in vascular development: vasculogenesis (formation of blood vessels from angioblasts), angiogenesis (formation of vascular sprouts from preexisting vessels), arteriogenesis (thickening and development of vessels) and lymphangiogenesis (formation of lymphatic vessels). In the last decade, these concepts, especially angiogenesis and lymphangiogenesis, have acquired major importance due to their role in tumoral growth and metastatic dissemination. Moreover, the activity of various diseases that involve chronic inflammation, such as asthma, psoriasis and rheumatoid arthritis, has been associated with vascular development. Several growth factors and cytokines are involved in this process and consequently investigation into these elements, both in peripheral blood and their expression in affected tissues, could elucidate the role of vascular development in diseases whose pathogenesis involves chronic inflammation, such as inflammatory bowel disease. The presence of distinct molecules involved in vascular development processes, such as vascular endothelial growth factor (VEGF), basic fibroblastic growth factor and placental growth factor, among others, has been studied in both ulcerative colitis and Crohn's disease, although not extensively. It has been suggested that the phenomena of vasculogenesis, angiogenesis and lymphangiogenesis play a critical, although not exclusive, role in the inflammation that characterizes inflammatory bowel disease. In general, the results obtained to date suggest that new vascular formation is involved in the pathogenesis of these diseases.

Role of angiogenesis in inflammatory bowel disease

Several studies have shown alterations in vascular anatomy and physiology in inflammatory bowel disease (IBD). These findings, together with the observed upregulation of the mediators of angiogenesis in IBD patients, suggest that angiogenesis possibly contributes to the initiation and perpetuation of IBD. There is considerable evidence of an interrelationship between the mechanisms of angiogenesis and chronic inflammation in IBD. The increased expression of endothelial junction adhesion molecules found in IBD patients indicates the presence of active angiogenesis. Evidence that angiogenesis is involved in IBD was also obtained from animal models of colitis, most notably from studies of angiogenesis inhibition. Serum levels of vascular endothelial growth factor (VEGF) correlate with disease activity in human IBD and fall with the use of steroids, thalidomide, or infliximab. Pharmacological inhibition of angiogenesis, therefore, has the potential to be a therapeutic strategy in IBD. This review outlines the evidence that the rate of angiogenesis is increased in the inflamed intestine in IBD and proposes lines for future research in this field.

Potential role of soluble angiopoietin-2 and Tie-2 in patients with inflammatory bowel disease

BACKGROUND

Angiogenesis has been suggested to play an important role in inflammatory bowel disease (IBD). The aim of the study was to evaluate the serum markers of angiogenesis angiopoietin-2 (Ang-2) and soluble angiopoietin receptor Tie-2 in patients with ulcerative colitis (UC) and Crohn's disease (CD).

MATERIALS AND METHODS

Serum Ang-2 and Tie-2 serum levels were measured in 160 IBD patients (79 UC and 81 CD) and in 80 matched healthy controls using commercially available enzyme-linked immunosorbent assays. Serum Ang-2 and Tie-2 levels were correlated with the disease activity, as well as the type, localization and treatment of the disease.

RESULTS

Median serum Ang-2 and Tie-2 levels were significantly higher in both the UC patients and the CD patients compared with the healthy controls (P < 0.05 and P < 0.001, respectively). The IBD patients with early disease (diagnosis < 2 years) had significantly higher (P = 0.04) median serum Ang-2 levels but significantly lower (P = 0.02) median serum Tie-2 levels as compared with IBD patients with late disease (diagnosis > 2 years). The CD patients with active disease had significantly higher levels of Ang-2 compared with non-active disease (P = 0.02). Serum levels of both Ang-2 and Tie-2 were not correlated with laboratory markers such as ESR, CRP, white blood cell count, platelet count and albumin.

CONCLUSIONS

Serum Ang-2 and Tie-2 levels are elevated in patients with IBD. These markers may mediate angiogenesis and vascular permeability in the mucosa of patients with IBD.

Mucosal repair and growth factors: recombinant human hepatocyte growth factor as an innovative therapy for inflammatory bowel disease

The repair of intestinal mucosal injuries is a tightly regulated process involving epithelial restitution, cell proliferation and maturation, and the dedifferentiation of epithelial cells. Deeper injuries also require additional repair mechanisms, including inflammatory processes, angiogenesis, and extracellular-matrix deposition. Once intestinal mucosal injury occurs, numerous growth factors and cytokines, including hepatocyte growth factor (HGF), keratinocyte growth factor, endothelial growth factor, epidermal growth factor, transforming growth factor-beta1, intestinal trefoil factor, interleukin (IL)-1, and IL-2, are induced in both the intestinal lumen and submucosa, and these factors cooperatively stimulate epithelial mucosal repair. HGF, a major agent promoting hepatocyte proliferation, also modulates intestinal epithelial cell proliferation and migration, leading to the acceleration of intestinal mucosal repair. Additionally, the proteolytic activation of HGF, which is mediated by HGF activator, is essential for the regeneration of injured intestinal mucosa. Recently, several studies have shown that the administration of recombinant human HGF or HGF gene therapy abrogates disease severity in several animal models of inflammatory bowel disease (IBD). Recombinant human HGF will soon be available for administration to patients with fulminant hepatic failure. Although additional preclinical biological studies are required, HGF has the potential to be an important new treatment modality promoting intestinal mucosal repair in patients with IBD.

Review article: angiogenesis soluble factors as liver disease markers

Angiogenesis is the formation of new blood vessels from pre-existing ones; it has been studied at the molecular level in different pathologies and is currently considered a promising novel therapeutic target in cancer. Recently, the use of angiogenesis soluble factors as markers of tumour growth has been investigated. The knowledge gained has led to test their use as therapeutic agents. Additionally, angiogenesis soluble factors could be used for the follow-up of pathologies that currently require monitoring with invasive techniques, like chronic viral hepatitis or renal and haematological diseases. The different factors have been described in multiple studies. In some cases, such as hepatocellular carcinoma, a potential use as prognostic markers has been suggested.

Effects of hepatocyte growth factor on rat inflammatory bowel disease models

Hepatocyte growth factor (HGF) is a hepatotrophic factor and, also, functions as an epithelial growth factor. We examined the therapeutic effects of HGF on rat inflammatory bowel disease models induced by trinitrobenzensulfonic acid or dextran sulfate sodium. Recombinant human HGF was continuously administered at 50 microg/body/day using an intraperitoneally implanted pump for 7 days. Treatment of HGF reduced the ulcerated area, histological damage score, mucosal myeloperoxidase activity, and epithelial apoptotic rate but did not increase epithelial mitotic rate and immunohistochemical labeling indexes of proliferating cell nuclear antigen, Ki-67, and bromodeoxyuridine as indexes of epithelial cell proliferation in either model. We then examined the epithelial localization of the HGF receptor c-met and identified it on the surface epithelia, where apoptosis was observed, but did not find it in the proliferative zone. These results suggest that HGF exhibits therapeutic effects via anti-inflammation including antiapoptosis rather than epithelial cell proliferation in these inflammatory bowel disease models.

Serum angiogenin in inflammatory bowel disease

Angiogenesis-promoting cytokines have been suggested to play an important role in inflammatory bowel disease (IBD) since they promote inflammation by increasing vascular permeability and mediate tissue repair by activating fibroblasts. The aim of the present study was to evaluate the serum levels of angiogenin, a potent angiogenic factor, in patients with ulcerative colitis (UC) and Crohn's disease (CD). Angiogenin serum levels were measured in 154 IBD patients (78 UC and 76 CD), in 18 cases with other causes of intestinal inflammation, and in 84 matched healthy controls using a commercially available enzyme-linked immunosorbent assay. Angiogenin levels were assessed in terms of disease activity, type, localization, and treatment. Mean (+/-SD) serum angiogenin levels were 526.5+/-224.1 ng/ml in UC patients, 508.8+/-228.5 ng/ml in CD patients, 394.6+/-137.6 ng/ml in healthy controls, and 448.1+/-167.8 ng/ml in patients with non-IBD intestinal inflammation. A statistically significant difference among the mean levels of angiogenin in the four groups was found (P = 0.0003). IBD patients with early disease had a significantly lower mean serum angiogenin compared with patients with late disease (P = 0.03). No significant association between angiogenin levels and disease activity, localization, disease type, or treatment was found. Serum angiogenin is elevated in patients with IBD. The increased serum angiogenin suggests that angiogenin may mediate angiogenesis and vascular permeability in the mucosa of patients with IBD.

Hepatocyte growth factor treatment ameliorates diarrhea and bowel inflammation in a rat model of inflammatory bowel disease

BACKGROUND/PURPOSE

Transfection of the HLA-B27 gene into normal Fischer rats induces phenotypic changes similar to inflammatory bowel disease (IBD). This study investigated the benefits of 2 doses of hepatocyte growth factor (HGF) on the manifestations of IBD in this rat model.

METHODS

Fischer rats and HLA-B27 rats were divided into 4 groups: Fischer rats treated with saline, HLA-B27 rats treated with saline, HGF at 150 microg/kg/d, and HGF at 300 microg/kg/d. HGF or saline was infused for 14 days via an osmotic pump attached to a catheter in the internal jugular vein. After treatment, rats were evaluated for diarrhea and reduction in gross and microscopic bowel inflammation. Statistics were determined using analysis of variance (ANOVA). A P value < or =.05 was considered significant.

RESULTS

Administration of HGF at 150 microg/kg/d decreased diarrhea by 40%, gross inflammation by 41%, and microscopic inflammation by 72% (P < or =.05). At 300 microg/kg/d HGF decreased diarrhea by 46%, gross inflammation by 45%, and microscopic inflammation by 54% (P < or =.05).

CONCLUSIONS

HGF administration reduces the clinical manifestations of IBD in this rat model. Similar effects were seen at both doses of HGF administration, implying that there is a plateau above which further increases in HGF levels provides no added benefit. HGF administration may be clinically useful in the management of IBD.

Hepatocyte growth factor: from diagnosis to clinical applications

Hepatocyte growth factor (HGF), initially identified and molecularly cloned as a potent mitogen of primary cultured hepatocytes, has multiple activities in a variety of tissues during the course of development and also in various disease states. HGF plays key roles in the attenuation of disease progression as an intrinsic repair factor. It is also evident that HGF levels are regulated under different conditions, for example, during the course of pregnancy, aging, and disease. This review focuses on the levels of HGF in normal and pathophysiological situations and examines the relationships between HGF levels and disease, disease stage, and disease prognosis. The clinical potential of HGF as a treatment for subjects with various diseases is also given attention.