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Higashimurayama-shi, Japan

Yada K.,Tokushima University | Ishibashi H.,Tokushima University | Mori H.,Tokushima University | Morine Y.,Tokushima University | And 4 more authors.
Surgery (United States) | Year: 2016

Background: Biliary atresia is the most common cause of end-stage liver disease in children. It is known that bile duct ligation contributes to liver fibrosis via bacterial translocation (BT) and toll-like receptor 4 (TLR4) signaling of hepatic stellate cells (HSCs). We have reported previously that the traditional Japanese medicine, "Dai-kenchu-to (TU-100)," a form of "Kampo medicine" prevents BT in rats exposed to the stress of fasting. The aim of this study was to clarify the effect of TU-100 on a rat model of biliary atresia using bile duct ligation. Methods: Bile duct ligation and subsequent daily oral administration of TU-100 was performed in 6-week-old rats. The rats were killed at 3, 7, or 14 days after bile duct ligation to evaluate the liver injury, occurrence of BT, and hepatic fibrosis. As an in vitro experiment, we isolated fresh HSCs from the rats undergoing bile duct ligation. After cell attachment, TU-100 and its 3 component herbs (eg, processed ginger, ginseng radix, and Japanese pepper) were added, and the expressions of Alpha actin2 (acta2), Alpha-1 type I collagen (colIa1), and tissue inhibitor of metalloproteinase 1 (timp1) were analyzed. Results: In vivo experiments demonstrated that oral administration of TU-100 decreased liver injury and atrophy of intestinal mucosa BT, hepatic fibrosis, and hepatic expression of alpha smooth muscle actin (αSMA) and TLR4, compared with rats that underwent bile duct ligation only. In vitro experiments showed that administration of TU-100 or the component herbs inhibited the expressions of acta2, colIa1, and timp1 in the HSCs. Conclusion: TU-100 prevented BT, activation of HSCs, and subsequent hepatic fibrosis. TU-100 may prevent progression of hepatic fibrosis in children with biliary atresia and improve prognosis. © 2016 Elsevier Inc.

Gala M.K.,Harvard University | Mizukami Y.,Harvard University | Mizukami Y.,Center for Clinical and Biomedical Research | Le L.P.,Harvard University | And 6 more authors.
Gastroenterology | Year: 2014

Background & Aims Little is known about the genetic factors that contribute to the development of sessile serrated adenomas (SSAs). SSAs contain somatic mutations in BRAF or KRAS early in development. However, evidence from humans and mouse models indicates that these mutations result in oncogene-induced senescence (OIS) of intestinal crypt cells. Progression to serrated neoplasia requires cells to escape OIS via inactivation of tumor suppressor pathways. We investigated whether subjects with multiple SSAs carry germline loss-of-function mutations (nonsense and splice site) in genes that regulate OIS: the p16-Rb and ATM-ATR DNA damage response pathways. Methods Through a bioinformatic analysis of the literature, we identified a set of genes that function at the main nodes of the p16-Rb and ATM-ATR DNA damage response pathways. We performed whole-exome sequencing of 20 unrelated subjects with multiple SSAs; most had features of serrated polyposis. We compared sequences with those from 4300 subjects matched for ethnicity (controls). We also used an integrative genomics approach to identify additional genes involved in senescence mechanisms. Results We identified mutations in genes that regulate senescence (ATM, PIF1, TELO2, XAF1, and RBL1) in 5 of 20 subjects with multiple SSAs (odds ratio, 3.0; 95% confidence interval, 0.9-8.9; P =.04). In 2 subjects, we found nonsense mutations in RNF43, indicating that it is also associated with multiple serrated polyps (odds ratio, 460; 95% confidence interval, 23.1-16,384; P = 6.8 × 10-5). In knockdown experiments with pancreatic duct cells exposed to UV light, RNF43 appeared to function as a regulator of ATM-ATR DNA damage response. Conclusions We associated germline loss-of-function variants in genes that regulate senescence pathways with the development of multiple SSAs. We identified RNF43 as a regulator of the DNA damage response and associated nonsense variants in this gene with a high risk of developing SSAs. © 2014 by the AGA Institute.

Mizukami Y.,Center for Clinical and Biomedical Research | Mizukami Y.,Asahikawa University | Mizukami Y.,Harvard University
Journal of Gastroenterology and Hepatology (Australia) | Year: 2012

Tumor-derived signals systemically induce an angiogenic switch that allows cancer cells to survive and grow. However, the vascular network in tumors is not well organized and fails to meet metabolic needs to maintain tissue homeostasis, resulting in significant hypoxia. Among various tumors, pancreatic ductal adenocarcinoma (PDAC) typically develops in an unusually disordered microenvironment, which contributes to its highly aggressive behavior. Since anti-vascular endothelial growth factor (VEGF) (Avastin) has failed to demonstrate a survival benefit in PDAC, we need to re-visit the basic biology of this disease and understand what makes it so refractory to the anti-angiogenic approaches that are clinically effective in other neoplasms. To address this issue, we specifically focused on the process of neovascularization where bone marrow-derived cells (BMDCs) play a role during pancreatic tumorigenesis. We have identified subsets of BMDCs that regulate key processes during development of the neovessels through paracrine Hedgehog signaling. Considering the importance of systemic responses occurring in tumor bearing hosts, we are currently using genetically engineered mice, which spontaneously develop PDAC, Pdx1-Cre;LSL-KrasG12D;p53lox/+ strain, to clarify critical events that can trigger aberrant angiogenesis in pancreatic cancer. These studies allow us to provide insights into the cellular and molecular mechanisms of pancreatic tumorigenesis and have an implication for the design of therapies against this difficult disease. © 2012 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

Duerr E.-M.,Harvard University | Duerr E.-M.,Ludwig Maximilians University of Munich | Mizukami Y.,Harvard University | Mizukami Y.,Center for Clinical and Biomedical Research | And 6 more authors.
American Journal of Physiology - Gastrointestinal and Liver Physiology | Year: 2012

Activating mutations in the KRAS oncogene are common in colorectal cancer. However, the complete spectrum of KRAS targets that mediate its tumorigenic effect has not yet been fully delineated. We identified bone morphogenetic protein 4 (Bmp4), a transforming growth factor-β family member that regulates development and tissue homeostasis, as a new target of KRAS. In SW480, Hela, and 293 cells, oncogenic KRAS V12 downregulated BMP4 RNA levels, a BMP4 promoter luciferase construct, and Bmp4 protein levels. The MEK inhibitor PD98059 but not the phosphatidylinositol 3-kinase inhibitor LY294002 blocked this downregulation of BMP4. To identify the region of the BMP4 promoter that mediated this regulation by KRAS, serial 5'-deletions of the promoter were generated. An inhibitory region was identified between -3,285 and -3,258 bp in the Bmp4 promoter. In summary, oncogenic KRAS can downregulate Bmp4 through a transcriptional pathway that depends on ERK. These findings point to a unique link between two pathways that are frequently altered in colon cancer. © 2012 the American Physiological Society.

Kono T.,Center for Clinical and Biomedical Research | Kono T.,Asahikawa University | Kaneko A.,Asahikawa University | Kaneko A.,Tsumura and Co. | And 5 more authors.
American Journal of Physiology - Gastrointestinal and Liver Physiology | Year: 2013

The functional roles of transient receptor potential (TRP) channels in the gastrointestinal tract have garnered considerable attention in recent years. We previously reported that daikenchuto (TU-100), a traditional Japanese herbal medicine, increased intestinal blood flow (IBF) via adrenomedullin (ADM) release from intestinal epithelial (IE) cells (Kono T et al. J Crohns Colitis 4: 161-170, 2010). TU-100 contains multiple TRP activators. In the present study, therefore, we examined the involvement of TRP channels in the ADM-mediated vasodilatatory effect of TU-100. Rats were treated intraduodenally with the TRP vanilloid type 1 (TRPV1) agonist capsaicin (CAP), the TRP ankyrin 1 (TRPA1) agonist allyl-isothiocyanate (AITC), or TU-100, and jejunum IBF was evaluated using laser-Doppler blood flowmetry. All three compounds resulted in vasodilatation, and the vasodilatory effect of TU-100 was abolished by a TRPA1 antagonist but not by a TRPV1 antagonist. Vasodilatation induced by AITC and TU-100 was abrogated by anti-ADM antibody treatment. RT-PCR and flow cytometry revealed that an IEC-6 cell line originated from the small intestine and purified IE cells expressed ADM and TRPA1 but not TRPV1. AITC increased ADM release in IEC cells remarkably, while CAP had no effect. TU-100 and its ingredient 6-shogaol (6SG) increased ADM release dose-dependently, and the effects were abrogated by a TRPA1 antagonist. 6SG showed similar TRPA1-dependent vasodilatation in vivo. These results indicate that TRPA1 in IE cells may play an important role in controlling bowel microcirculation via ADM release. Epithelial TRPA1 appears to be a promising target for the development of novel strategies for the treatment of various gastrointestinal disorders. © 2013 the American Physiological Society.

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