Keisho Kataoka

Interferon-gamma is causatively involved in experimental inflammatory bowel disease in mice.

Cytokines may be crucially involved in the pathogenesis of inflammatory bowel diseases (IBD), but it remains controversial whether interferon (IFN)‐γ, a typical proinflammatory cytokine, is an essential mediator to cause the disorders. In the present study, IFN‐γ–/– and wild‐type (WT) C57BL/6 mice were fed 2·5% dextran sodium sulphate (DSS) in drinking water for 7 days, in order to investigate DSS‐induced intestinal inflammation. The DSS‐treated WT mice exhibited a robust production of IFN‐γ in the gut, a remarkable loss of body weight, as well as high rate of mortality (60%). In striking contrast, IFN‐γ deficient mice did not develop DSS‐induced colitis, as indicated by the maintenance of body weight and survival rate of 100%. Severe intestinal inflammation was demonstrated exclusively in WT animals in terms of the shortening of the bowel as well as the elevation of the disease activity index, myeloperoxidase (MPO) activity and serum haptoglobin level. Histological study of DSS‐treated WT intestine revealed disruption of mucosal epithelium and massive infiltration of inflammatory cells, while the organ from IFN‐γ–/– mice remained virtually normal in appearance. Enzyme‐linked immunosorbent assay (ELISA) analyses indicated abundant production of three chemokines, i.e. monokine induced by interferon‐γ (MIG), interferon‐inducible protein 10 (IP‐10) and monocyte chemoattractant protein‐1 (MCP‐1), in the DSS‐irritated intestine of WT but not of IFN‐γ–/– mice. The present results demonstrate clearly that IFN‐γ plays indispensable roles in the initiation of DSS colitis, and some chemokines are produced in an IFN‐γ‐dependent fashion.

Involvement of IL-17A in the pathogenesis of DSS-induced colitis in mice

To investigate the etiological implication of IL-17A in inflammatory bowel disease (IBD), dextran sodium sulfate (DSS) was administered to the mice deficient for the IL-17A gene. They showed only faint manifestations of colitis, as revealed by body weight loss, shrinkage in the colon length, serum haptoglobin concentration, and disease activity index. Although the mortality rate of WT mice reached approximately 60%, more than 90% of the IL-17A KO mice survived the DSS treatment. Histological change was also marginal in the IL-17A KO intestine, in which epithelial damage and inflammatory infiltrates were not obvious and the myeloperoxidase activity elevated only slightly. G-CSF and MCP-1 were abundantly produced in WT mouse intestine, whereas the production of these chemokines was drastically hampered in IL-17A-null intestine. The present results show that IL-17A plays a pivotal role in the pathogenesis of DSS-induced colitis, while MCP-1 and G-CSF may be crucially involved in the IL-17A-induced inflammation.

Baicalein Overcomes Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand Resistance via Two Different Cell-Specific Pathways in Cancer Cells but not in Normal Cells

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is one of the most promising candidates for new cancer therapeutics. A current problem is that some cancers still remain resistant to TRAIL. We show for the first time that a naturally occurring flavonoid, baicalein, overcomes TRAIL resistance in cancer cells. The combination of baicalein and TRAIL effectively induced apoptosis in TRAIL-resistant colon cancer SW480 cells. Baicalein up-regulated the expression of death receptor 5 (DR5) among TRAIL receptors at the mRNA and protein levels. Suppression of this up-regulation with small interfering RNA (siRNA) efficiently reduced the apoptosis induced by TRAIL and baicalein, suggesting that the sensitization was mediated through DR5 induction. Moreover, baicalein also overcame TRAIL resistance with DR5 up-regulation in prostate cancer PC3 cells. Of note, the combination of TRAIL and baicalein hardly induced apoptosis in normal human cells, such as blood cells and hepatocytes. Baicalein increased DR5 promoter activity, and this enhanced activity was diminished by mutation of a CCAAT/enhancer-binding protein homologous protein (CHOP)-binding site in SW480 cells. In SW480 cells, CHOP siRNA blocked both functions of baicalein. CHOP expression was induced by baicalein in SW480 cells; however, in PC3 cells, baicalein scarcely induced CHOP and mutation of the CHOP-binding site did not abrogate the DR5 promoter activation by baicalein. Interestingly, baicalein induced reactive oxygen species (ROS) and a ROS scavenger prevented DR5 expression and TRAIL sensitization in PC3 but not SW480 cells. These results indicate that, using two different pathways, baicalein exposes cancer surveillance of TRAIL and overcomes TRAIL resistance in cancer cells.

Japanese guidelines for the management of acute pancreatitis: Japanese Guidelines 2015.

Japanese (JPN) guidelines for the management of acute pancreatitis were published in 2006. The severity assessment criteria for acute pancreatitis were later revised by the Japanese Ministry of Health, Labour and Welfare (MHLW) in 2008, leading to their publication as the JPN Guidelines 2010. Following the 2012 revision of the Atlanta Classifications of Acute Pancreatitis, in which the classifications of regional complications of pancreatitis were revised, the development of a minimally invasive method for local complications of pancreatitis spread, and emerging evidence was gathered and revised into the JPN Guidelines.

The revised Japanese clinical diagnostic criteria for chronic pancreatitis

In Japan, we are now using the clinical diagnostic criteria for chronic pancreatitis (CP) that were revised in 2001 to add the findings of magnetic resonance cholangiopancreatography to the criteria compiled by the Japan Pancreas Society (JPS) in 1995. Because the current criteria are set for diagnosing advanced CP, they are unlikely to improve patients’ prognoses. In addition, they seem unsuitable for current clinical practice because exocrine pancreatic function tests, which have become obsolete in Japan, are included in the diagnostic factors. For these reasons, the Research Committee on Intractable Pancreatic Diseases supported by the Ministry of Health, Labour and Welfare of Japan, the JPS and the Japanese Society of Gastroenterology have revised the criteria. The revised criteria are unique in that they contain an introduction to the concept of early CP. It is a challenge aimed at improvement of the long-term prognosis of CP patients by early diagnosis and therapeutic intervention in this disease. We need to determine and clarify the clinico-pathological outcome of early CP by a prospective long-term follow-up of the patients in this category.

Assessment of severity of acute pancreatitis according to new prognostic factors and CT grading.

The assessment of severity at the initial medical examination plays an important role in introducing adequate early treatment and the transfer of patients to a medical facility that can cope with severe acute pancreatitis. Under these circumstances, “criteria for severity assessment” have been prepared in various countries, including Japan, and these criteria are now being evaluated. The criteria for severity assessment of acute pancreatitis in Japan were determined in 1990 (of which a partial revision was made in 1999). In 2008, an overall revision was made and the new Japanese criteria for severity assessment of acute pancreatitis were prepared. In the new criteria for severity assessment, the diagnosis of severe acute pancreatitis can be made according to 9 prognostic factors and/or the computed tomography (CT) grades based on contrast-enhanced CT. Patients with severe acute pancreatitis are expected to be transferred to a specialist medical center or to an intensive care unit to receive adequate treatment there. In Japan, severe acute pancreatitis is recognized as being a specified intractable disease on the basis of these criteria, so medical expenses associated with severe acute pancreatitis are covered by Government payment.

Post-ERCP pancreatitis

Pancreatitis remains the most common severe complication of endoscopic retrograde cholangiopancreatography (ERCP). Detailed information about the findings of previous studies concerning post-ERCP pancreatitis has not been utilized sufficiently. The purpose of the present article was to present guidelines for the diagnostic criteria of post-ERCP pancreatitis, and its incidence, risk factors, and prophylactic procedures that are supported by evidence. To achieve this purpose, a critical examination was made of the articles on post-ERCP pancreatitis, based on the data obtained by research studies published up to 2009. At present, there are no standardized diagnostic criteria for post-ERCP pancreatitis. It is appropriate that post-ERCP pancreatitis is defined as acute pancreatitis that has developed following ERCP, and its diagnosis and severity assessment should be made according to the diagnostic criteria and severity assessment of the Japanese Ministry of Health, Labour and Welfare. The incidence of acute pancreatitis associated with diagnostic and therapeutic ERCP is 0.4–1.5 and 1.6–5.4%, respectively. Endoscopic papillary balloon dilation is associated with a high risk of acute pancreatitis compared with endoscopic sphincterotomy. It was made clear that important risk factors include dysfunction of the Oddi sphincter, being of the female sex, past history of post-ERCP pancreatitis, and performance of pancreaticography. Temporary prophylactic placement of pancreatic stents in the high-risk group is useful for the prevention of post-ERCP pancreatitis [odds ratio (OR) 3.2, 95% confidence interval (CI) 1.6–6.4, number needed to treat (NNT) 10]. Use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a reduction in the development of post-ERCP pancreatitis (OR 0.46, 95% CI 0.32–0.65). Single rectal administration of NSAIDs is useful for the prevention of post-ERCP pancreatitis [relative risk (RR) 0.36, 95% CI 0.22–0.60, NNT 15] and decreases the development of pancreatitis in both the low-risk group (RR 0.29, 95% CI 0.12–0.71) and the high-risk group (RR 0.40, 95% CI 0.23–0.72) of post-ERCP pancreatitis. As for somatostatin, a bolus injection may be most useful compared with short- or long-term infusion (OR 0.271, 95% CI 0.138–0.536, risk difference 8.2%, 95% CI 4.4–12.0%). The usefulness of gabexate mesilate was not apparent in any of the following conditions: acute pancreatitis (control 5.7 vs. 4.8% for gabexate mesilate), hyperamylasemia (40.6 vs. 36.9%), and abdominal pain (1.7 vs. 8.9%). Formulation of diagnostic criteria for post-ERCP pancreatitis is needed. Temporary prophylactic placement of pancreatic stents in the high-risk group offers the most promise as a means of preventing post-ERCP pancreatitis. As for pharmacological attempts, there are high expectations concerning NSAIDs because they are excellent in terms of cost-effectiveness, ease of use, and safety. There was no evidence of effective prophylaxis with the use of protease inhibitors, especially gabexate mesilate.

CYTOKINE EXPRESSION AND INDUCTION OF ACINAR CELL APOPTOSIS AFTER PANCREATIC DUCT LIGATION IN MICE

To clarify the role of cytokines and acinar cell apoptosis in the pathogenesis of acute pancreatitis, we investigated the expression of intrapancreatic cytokines and apoptosis-related molecules in mice after pancreatic duct ligation (PDL). From day 1 or 3 after PDL, the expression of interleukin-1alpha (IL-1alpha), IL-1beta, IL-1 receptor antagonist, IL-6, IL-10, and tumor necrosis factor (TNF-alpha) mRNA were up-regulated in the pancreas, suggesting that these cytokines may be involved in the development of pancreatitis after PDL. Acinar cell apoptosis was observed in the pancreas at rates of 0.13 +/- 0.03, 1.32 +/- 0.38, and 0.86 +/- 0.23% on days 1, 3, and 7 after PDL, respectively. Significant increases in intrapancreatic mRNA levels of TNF-alpha, Fas ligand (FasL), and IL-1beta-converting enzyme (ICE) were observed from day 3 after PDL with the appearance of acinar cell apoptosis. The serum amylase activity peaked on day 1 after PDL and gradually decreased on days 3 and 7 after PDL. These results suggest that acinar cell apoptosis induced after PDL may modulate the progression of acute pancreatitis by reducing the release of digestive enzymes and may therefore be a host defense mechanism, and that acinar cell apoptosis after PDL may be mediated by the TNF-alpha and/or Fas/FasL and ICE system.

Comparative Distribution of Nitric Oxide Synthase (NOS) in Pancreas of the Dog and Rat: Immunocytochemistry of Neuronal Type NOS and Histochemistry of NADPH-Diaphorase

We investigated the localization of nitric oxide synthase in the pancreas of the dog in comparison to the rat by the methods of immunocytochemistry using antineuronal type nitric oxide synthase serum and histochemistry using NADPH-diaphorase activity. In both species, the most intense staining was observed in neuronal cell bodies and fibers in the pancreas and nitric oxide synthase immunoreactivity was completely colocalized with NADPH-diaphorase activity. However, there were differences of the distribution between the two species. In the dog pancreas, immuno- and NADPH-diaphorase-positive nerve fibers were numerous around pancreatic ducts and moderate around the arteries and the acini but few in the islets. In contrast, in the rat pancreas, immuno- and diaphorase-positive fibers were fewer around the pancreatic ducts and acini and more abundant in the islets. The expression ratio of NADPH-diaphorase in intrapancreatic ganglion cell bodies that were scattered in the interlobular connective tissue was low to moderate (28.1% in the right lobe, 49.5% in the left lobe) in the dog, while the ratio in rat pancreas was very high in both lobes of the pancreas (about 86%). Except for neuronal staining, weak NADPH-diaphorase-positive reactions were detected in the vascular endothelial cells of the pancreas in both species. In rat islet cells, weak neuronal type nitric oxide synthase immunoreactivity was observed; however, in dog islet cells, no immunoreactivity was detected. These results suggest that nitric oxide in the pancreas is derived from vascular endothelium and neuronal tissue in both species and that the neuronal nitrergic regulation of the exocrine and endocrine pancreas is different between the species.

Evidence-based clinical practice guidelines for chronic pancreatitis 2015.

Chronic pancreatitis is considered to be an irreversible progressive chronic inflammatory disease. The etiology and pathology of chronic pancreatitis are complex; therefore, it is important to correctly understand the stage and pathology and provide appropriate treatment accordingly. The newly revised Clinical Practice Guidelines of Chronic Pancreatitis 2015 consist of four chapters, i.e., diagnosis, staging, treatment, and prognosis, and includes a total of 65 clinical questions. These guidelines have aimed at providing certain directions and clinically practical contents for the management of chronic pancreatitis, preferentially adopting clinically useful articles. These revised guidelines also refer to early chronic pancreatitis based on the Criteria for the Diagnosis of Chronic Pancreatitis 2009. They include such items as health insurance coverage of high-titer lipase preparations and extracorporeal shock wave lithotripsy, new antidiabetic drugs, and the definition of and treatment approach to pancreatic pseudocyst. The accuracy of these guidelines has been improved by examining and adopting new evidence obtained after the publication of the first edition.