Masatsugu Numata

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-β1, 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.

Increased rate of death related to presence of viremia among hepatitis C virus antibody–positive subjects in a community-based cohort study†

The overall mortality of patients infected with hepatitis C virus (HCV) has not been fully elucidated. This study analyzed mortality in subjects positive for antibody to HCV (anti‐HCV) in a community‐based, prospective cohort study conducted in an HCV hyperendemic area of Japan. During a 10‐year period beginning in 1995, 1125 anti–HCV‐seropositive residents of Town C were enrolled into the study and were followed for mortality through 2005. Cause of death was assessed by death certificates. Subjects with detectable HCV core antigen (HCVcAg) or HCV RNA were considered as having hepatitis C viremia and were classified as HCV carriers; subjects who were negative for both HCVcAg and HCV RNA (i.e., viremia‐negative) were considered as having had a prior HCV infection and were classified as HCV noncarriers. Among the anti–HCV‐positive subjects included in the analysis, 758 (67.4%) were HCV carriers, and 367 were noncarriers. A total of 231 deaths occurred in these subjects over a mean follow‐up of 8.2 years: 176 deaths in the HCV carrier group and 55 in the noncarrier group. The overall mortality rate was higher in HCV carriers than in noncarriers, adjusted for age and sex (hazard ratio, 1.53; 95% confidence interval, 1.13‐2.07). Although liver‐related deaths occurred more frequently among the HCV carriers (hazard ratio, 5.94; 95% confidence interval, 2.58‐13.7), the rates of other causes of death did not differ between HCV carriers and noncarriers. Among HCV carriers, a higher level of HCVcAg (≥100 pg/mL) and persistently elevated alanine aminotransferase levels were important predictors of liver‐related mortality. Conclusion: The presence of viremia increases the rate of mortality, primarily due to liver‐related death, among anti–HCV‐seropositive persons in Japan. (HEPATOLOGY 2009.)

Hepatocyte growth factor accelerates the proliferation of hepatic oval cells and possibly promotes the differentiation in a 2-acetylaminofluorene/partial hepatectomy model in rats

Background:  Hepatocyte growth factor (HGF) is the primary agent promoting the proliferation of mature hepatocytes. The purpose of the present paper was to clarify the effects of HGF on the proliferation and  differentiation  of  hepatic  oval  cells  using  a  2‐acetylaminofluorene/partial  hepatectomy  (2‐AAF/PH) model in rats.

Safety and pharmacokinetics of recombinant human hepatocyte growth factor (rh-HGF) in patients with fulminant hepatitis: a phase I/II clinical trial, following preclinical studies to ensure safety

BackgroundHepatocyte growth factor (HGF) stimulates hepatocyte proliferation, and also acts as an anti-apoptotic factor. Therefore, HGF is a potential therapeutic agent for treatment of fatal liver diseases. We performed a translational medicine protocol with recombinant human HGF (rh-HGF), including a phase I/II study of patients with fulminant hepatitis (FH) or late-onset hepatic failure (LOHF), in order to examine the safety, pharmacokinetics, and clinical efficacy of this molecule.MethodsPotential adverse effects identified through preclinical safety tests with rh-HGF include a decrease in blood pressure (BP) and an increase in urinary excretion of albumin. Therefore, we further investigated the effect of rh-HGF on circulatory status and renal toxicity in preclinical animal studies. In a clinical trial, 20 patients with FH or LOHF were evaluated for participation in this clinical trial, and four patients were enrolled. Subjects received rh-HGF (0.6 mg/m2/day) intravenously for 12 to 14 days.ResultsWe established an infusion method to avoid rapid BP reduction in miniature swine, and confirmed reversibility of renal toxicity in rats. Although administration of rh-HGF moderately decreased BP in the participating subjects, this BP reduction did not require cessation of rh-HGF or any vasopressor therapy; BP returned to resting levels after the completion of rh-HGF infusion. Repeated doses of rh-HGF did not induce renal toxicity, and severe adverse events were not observed. Two patients survived, however, there was no evidence that rh-HGF was effective for the treatment of FH or LOHF.ConclusionsIntravenous rh-HGF at a dose of 0.6 mg/m2 was well tolerated in patients with FH or LOHF; therefore, it is desirable to conduct further investigations to determine the efficacy of rh-HGF at an increased dose.

Human neutrophil peptides 1-3 are useful biomarkers in patients with active ulcerative colitis.

Background: A specific useful biomarker for diagnosing ulcerative colitis (UC) has not yet been described. This study employed proteomics to identify serum protein biomarkers for UC. Methods: Ninety‐four blood samples were isolated from patients and controls (including 48 UC, 22 Crohns disease [CD], 5 colorectal cancer, and 6 infectious colitis patients and 13 healthy subjects). Serum samples were analyzed using the SELDI‐TOF/MS ProteinChip system. After applying the samples to ProteinChip arrays, we assessed differences in the proteomes using Ciphergen ProteinChip software and identified candidate proteins, which were then characterized in immunoassays. Results: Preliminary analysis using the ProteinChip system revealed significant peak‐intensity differences for 27 serum proteins between 11 patients with UC and 7 healthy subjects. Among these proteins, 3 proteins (with mass/charge ratios of approximately 3400) were identified as human neutrophil peptides 1–3 (HNP 1–3). The presence of HNP 1–3 in the patient sera was confirmed using immunoassays. Enzyme‐linked immunosorbent assays demonstrated that the mean plasma concentration of HNP 1–3 was significantly higher in patients with active UC (n = 28) than in patients whose UC was in remission (n = 20) or patients with CD (n = 22), infectious colitis, or healthy subjects, and tended to be higher than in patients with colon cancer. In addition, the plasma concentration of HNP 1–3 in patients that responded to corticosteroids‐based therapy decreased after treatment, whereas it was not changed in nonresponders. Conclusions: HNP 1–3 is a novel biomarker that may be useful for diagnosing patients with active UC and predicting treatment outcomes.

Hepatocyte growth factor facilitates the repair of large colonic ulcers in 2,4,6-trinitrobenzene sulfonic acid-induced colitis in rats

Background: Hepatocyte growth factor (HGF) modulates intestinal epithelial cell proliferation and migration, serving as a critical regulator of intestinal wound healing. The aim of this study was to clarify the effects of administration of recombinant human HGF on colonic mucosal damage in vivo. Methods: Rats were given 7.5 mg of 2,4,6‐trinitrobenzene sulfonic acid (TNBS) per rectum on day 0. On day 5, the degree of TNBS‐induced colitis was evaluated endoscopically, and rats suffering from large ulcers (occupying more than two thirds of the luminal circumference) were treated with intravenous bolus injections of recombinant human HGF (1.0 mg/kg per day) or phosphate‐buffered saline (PBS) for 5 days. Results: Rats with TNBS‐induced colitis given human HGF showed a significant reduction in colonic ulcer coverage and large intestinal shortening compared with those treated with PBS. Administration of recombinant human HGF also stimulated the proliferation of epithelial cells and reduced the inflammatory cell infiltrate. Finally, HGF treatment decreased the myeloperoxidase activity and tumor necrosis factor &agr; levels in the TNBS‐inflamed colon tissues. Conclusions: These results indicate that intravenous injection of HGF accelerates colonic mucosal repair and reduces infiltration of inflammatory cells in rats with TNBS‐induced colitis and suggest that HGF has the potential to be a new therapeutic modality to promote intestinal mucosal repair in patients with inflammatory bowel disease.

Endoscopic characterization of the small bowel in patients with portal hypertension evaluated by double balloon endoscopy

BackgroundThe endoscopic abnormalities present in the small bowel (SB) of patients with portal hypertension (PH) are not well understood. This study sought to evaluate endoscopic findings of the SB in patients with PH by double balloon endoscopy (DBE).MethodsWe evaluated the endoscopic findings of SB in 15 patients with PH and 49 controls without liver disease or PH. A total of 24 and 90 procedures were performed for PH patients and control patients, respectively, through oral and/or anal approaches.ResultsFourteen of the 15 patients exhibited villous abnormalities, including edema (73%), atrophy (40%), and reddening (47%) of villi. Vascular lesions, such as angiodysplasia-like abnormalities (67%), dilated/proliferated vessels (93%), and varices (7%), were observed in all patients with PH. Although they were associated with ascites, these abnormalities did not correlate with any laboratory findings. None of these abnormalities was observed in controls. Definitive or suspected bleeding sources were identified in 9 of 13 patients with both PH and obscure gastrointestinal bleeding (OGIB), which was similar to the incidence in controls with OGIB. Although the frequency of postprocedure fever (>37.5°C) was higher in patients with PH in comparison to controls (29% vs. 2%, P < 0.01), endoscopic treatment under DBE was performed on 3 PH patients without serious complications.ConclusionsEndoscopic abnormalities of the SB may be prevalent in patients with PH. Although postprocedure fever of DBE may occur more commonly in patients with PH, DBE is useful as both a diagnostic and therapeutic tool to evaluate the SB.

Human neutrophil peptides induce interleukin-8 in intestinal epithelial cells through the P2 receptor and ERK1/2 signaling pathways

Human neutrophil peptides (HNPs) are antimicrobial peptides produced predominantly by neutrophils. We have previously reported that HNP 1-3 levels are increased in the sera and plasma of patients with active ulcerative colitis. The increased expression of interleukin-8 (IL-8) has also been demonstrated in the colonic mucosa of patients with active ulcerative colitis. HNPs induce IL-8 in lung epithelial cells and monocytes through the P2Y6 signaling pathway. However, the association between HNPs and IL-8 in the intestinal mucosa has not yet been investigated. In the present study, we investigated the effects of HNP-1 on the production of IL-8 by human intestinal epithelial cells and the underlying signaling mechanisms. We observed a significant increase in IL-8 expression in the human colon carcinoma cell line, Caco-2, following treatment with HNP-1. The non-selective P2 receptor antagonists, suramin and pyridoxal phosphate-6-azo (benzene-2,4-disulfonic acid) tetrasodium salt hydrate (PPADS), significantly blocked the HNP-1-induced expression of IL-8 in the Caco-2 cells. The P2Y6-specific antagonist, MRS2578, led to a significant but partial decrease in IL-8 expression, suggesting that P2 receptors in addition to P2Y6 are involved in the HNP-1-induced production of IL-8 by Caco-2 cells. In agreement with this finding, HNP-1 also significantly increased IL-8 production in the P2Y6-negative human colon cancer cell line, HT-29, and this increase was blocked by treatment with suramin and PPADS. HNP-1 significantly increased the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) in the HT-29 cells. However, the HNP-1-induced production of IL-8 was suppressed by the ERK1/2 inhibitor, U0126, but not by the p38 MAPK inhibitor, SB203580. In conclusion, our data demonstrate that HNP-1 induces IL-8 production not only through P2Y6, but also through additional P2 receptors via an ERK1/2-dependent mechanism in intestinal epithelial cells.

Effect of Endoscopic Submucosal Dissection for Superficial Esophageal Neoplasms and Risk Factors for Postoperative Stricture

AbstractEndoscopic submucosal dissection (ESD) enables wider tumor resection compared with endoscopic mucosal resection and en bloc resection of superficial esophageal neoplasms. However, ESD may cause difficult-to-treat stricture of the esophagus, and therefore, prediction of and measures against postoperative esophageal stricture are critical. The aim of this study was to evaluate the effect of ESD on superficial esophageal neoplasms and identify risk factors associated with esophageal stricture after ESD.This study included 165 lesions in 120 patients with superficial esophageal neoplasms, including cancer and neoplasia, who underwent ESD from 2009 to 2013.The complete resection rate of superficial esophageal neoplasms by ESD was 90.9%. After ESD, 22 subjects (18.3%) had symptomatic esophageal stricture, 12 (10.0%) had aspiration pneumonia of grade 2, and 7 (5.8%) had mediastinal emphysema of grade 2. Comparison of the 22 subjects with stricture with the 98 subjects without stricture showed significant differences in the rate of resection of >75% of the esophageal circumference, rate of whole circumference resection, and the required time for resection. The tumor size and the size of the resected tissue sample also differed between the 2 groups. The groups did not differ in age, sex, alcohol intake, and smoking; location, macroscopic, and histological tumor findings; chest pain; or use of anticoagulants for comorbidities. In multivariate analysis, tumor size and whole circumference resection were independent risk factors for stricture. Furthermore, in 45 subjects with resection of >75% of the esophageal circumference, whole resection of the esophagus was the only independent risk factor for stricture.This study suggests that ESD has a strong therapeutic effect on superficial esophageal neoplasms; however, a greater extent of resection of the esophagus increases the risk of postoperative esophageal stricture. Preventive measures against development of postoperative stricture require further study.

Translational research on HGF: A phase I/II study of recombinant human HGF for the treatment of fulminant hepatic failure

Hepatocyte growth factor (HGF) is a potential therapeutic agent for fatal liver diseases, including fulminant hepatic failure (FHF). After performing a number of preclinical tests with recombinant human HGF (rh‐HGF), we started a phase I/II study in September 2005 of patients with FHF or late‐onset hepatic failure (LOHF), to examine the safety and clinical efficacy of rh‐HGF. We first administered rh‐HGF (0.6 mg/m2/day) for 13 days to a 67‐year‐old Japanese man with FHF. All data from this patient were reviewed by the independent data monitoring committee, and the safety of rh‐HGF was recognized. Finally, a clinical trial of rh‐HGF was approved to be continued. As of August 2007, we have administered rh‐HGF to four patients with FHF or LOHF. All patients showed a moderate decrease in systolic blood pressure during rh‐HGF administration, while the urinary excretion of albumin did not increase in all cases. In the first and third patients, hepatic failure gradually progressed, and they died 66 and 29 days, respectively, after encephalopathy occurred. The second and fourth patients are presently still alive. In conclusion, we started a clinical trial that examined the effects of rh‐HGF in patients with FHF or LOHF, and in the four patients with FHF or LOHF enrolled in this study, repeated doses of rh‐HGF did not produce any severe side effects.