Publications by authors named "Tatsunori Suzuki"

52 Publications

Dimethylarginine dimethylaminohydrolase 1 as a novel regulator of oligodendrocyte differentiation in the central nervous system remyelination.

Glia 2021 Jul 16. Epub 2021 Jul 16.

Department of Molecular Pharmacology, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan.

Remyelination is a regenerative process that restores the lost neurological function and partially depends on oligodendrocyte differentiation. Differentiation of oligodendrocytes spontaneously occurs after demyelination, depending on the cell intrinsic mechanisms. By combining a loss-of-function genomic screen with a web-resource-based candidate gene identification approach, we identified that dimethylarginine dimethylaminohydrolase 1 (DDAH1) is a novel regulator of oligodendrocyte differentiation. Silencing DDAH1 in oligodendrocytes prevented the expression of myelin basic protein in mouse oligodendrocyte culture with the change in expression of genes annotated with oligodendrocyte development. DDAH1 inhibition attenuated spontaneous remyelination in a cuprizone-induced demyelinated mouse model. Conversely, increased DDAH1 expression enhanced remyelination capacity in experimental autoimmune encephalomyelitis. These results provide a novel therapeutic option for demyelinating diseases by modulating DDAH1 activity.
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http://dx.doi.org/10.1002/glia.24060DOI Listing
July 2021

Comprehensive Exploration of Medications That Affect the Bleeding Risk of Oral Anticoagulant Users.

Biol Pharm Bull 2021 ;44(5):611-619

Faculty of Pharmaceutical Sciences, Tokyo University of Science (TUS).

Oral anticoagulants (OACs) pose a major bleeding risk, which may be increased or decreased by concomitant medications. To explore medications that affect the bleeding risk of OACs, we conducted a nested case-control study including 554 bleeding cases (warfarin, n = 327; direct OACs [DOACs], n = 227) and 1337 non-bleeding controls (warfarin, n = 814; DOACs, n = 523), using a Japanese health insurance database from January 2005 to June 2017. Major bleeding risk associated with exposure to concomitant medications within 30 d of the event/index date was evaluated, and adjusted odds ratios (aORs) were calculated using logistic regression analysis. Several antihypertensive drugs, such as amlodipine and bisoprolol, were associated with a decreased risk of bleeding (warfarin + amlodipine [aOR, 0.64; 95% confidence interval (CI): 0.41-0.98], DOACs + bisoprolol [aOR, 0.51; 95% CI, 0.33-0.80]). As hypertension is considered a significant risk factor for intracranial bleeding in antithrombotic therapy, antihypertensive drugs may suppress intracranial bleeding. In contrast, telmisartan, a widely used antihypertensive drug, was associated with an increased risk of bleeding [DOACs + telmisartan (aOR, 4.87; 95% CI, 1.84-12.91)]. Since telmisartan is an inhibitor of P-glycoprotein (P-gp), the elimination of rivaroxaban and apixaban, which are substrates of P-gp, is hindered, resulting in increased blood levels of both drugs, thereby increasing the risk of hemorrhage. In conclusion, antihypertensive drugs may improve the safety of OACs, and the pharmacokinetic-based drug interactions of DOACs must be considered.
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http://dx.doi.org/10.1248/bpb.b20-00791DOI Listing
January 2021

Mutant KRAS drives metabolic reprogramming and autophagic flux in premalignant pancreatic cells.

Cancer Gene Ther 2021 Apr 8. Epub 2021 Apr 8.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan.

Mutational activation of the KRAS gene occurs in almost all pancreatic ductal adenocarcinoma (PDAC) and is the earliest molecular event in their carcinogenesis. Evidence has accumulated of the metabolic reprogramming in PDAC, such as amino acid homeostasis and autophagic flux. However, the biological effects of KRAS mutation on metabolic reprogramming at the earlier stages of PDAC carcinogenesis are unclear. Here we report dynamic metabolic reprogramming in immortalized human non-cancerous pancreatic ductal epithelial cells, in which a KRAS mutation was induced by gene-editing, which may mimic early pancreatic carcinogenesis. Similar to the cases of PDAC, KRAS gene mutation increased the dependency on glucose and glutamine for maintaining the intracellular redox balance. In addition, the intracellular levels of amino acids were significantly decreased because of active protein synthesis, and the cells required greater autophagic flux to maintain their viability. The lysosomal inhibitor chloroquine significantly inhibited cell proliferation. Therefore, metabolic reprogramming is an early event in carcinogenesis initiated by KRAS gene mutation, suggesting a rationale for the development of nutritional interventions that suppress or delay the development of PDAC.
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http://dx.doi.org/10.1038/s41417-021-00326-4DOI Listing
April 2021

Emerging Roles of Exosomal Circular RNAs in Cancer.

Front Cell Dev Biol 2020 8;8:568366. Epub 2020 Oct 8.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

Circular RNA (circRNA) is a type of non-coding RNA that forms a covalently closed continuous loop. The expression pattern of circRNA varies among cell types and tissues, and many circRNAs are aberrantly expressed in various cancers. Aberrantly expressed circRNAs have been shown to play crucial roles in carcinogenesis, functioning as microRNA sponges or new templates for protein translation. Recent research has shown that circRNAs are enriched in exosomes. Exosomes are secretory vesicles that mediate intercellular communication through the delivery of cargo, including proteins, lipids, DNA, and RNA. Exosome-mediated crosstalk between cancer cells and the tumor microenvironment promotes the epithelial-mesenchymal transition, angiogenesis, and immune escape, and thus may contribute to cancer invasion and metastasis. In this review, we discuss the biological functions of exosomal circRNAs and their significance in cancer progression. Additionally, we discuss the potential clinical applications of exosomal circRNAs as biomarkers and in cancer therapy.
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http://dx.doi.org/10.3389/fcell.2020.568366DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578227PMC
October 2020

Endoscopic Ultrasound-Guided Tissue Acquisition by 22-Gauge Franseen and Standard Needles for Solid Pancreatic Lesions.

Gut Liver 2020 11;14(6):817-825

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Japan.

Background/aims: Recently, a three-plane symmetric needle with Franseen geometry was developed for endoscopic ultrasound-guided fine needle biopsy (EUS-FNB). In this retrospective study, tissue acquisition per pass was compared between 22-gauge Franseen FNB and standard fine needle aspiration (FNA) needles in patients with solid pancreatic lesions.

Methods: Consecutive patients who underwent EUSFNA or EUS-FNB for solid pancreatic lesions between October 2014 and March 2018 were retrospectively studied. The tissue acquisition rate and the diagnostic performance per session, per pass, and at first pass were compared.

Results: A total of 663 passes (300 by the FNB needle and 363 by the standard FNA needle) were performed in 154 patients (71 FNB and 83 FNA). The tissue acquisition rate per session and at first pass in the FNB and FNA groups was 100% and 95% (p=0.13) and 87% and 69% (p=0.007), respectively. The multivariate analysis revealed that among the patients, EUS-FNB (odds ratio, 3.07; p=0.01) was associated with a higher first-pass tissue acquisition rate. While the tissue acquisition rate reached a plateau after the 4th pass with FNA, it reached a plateau after the 2nd pass with FNB. Among the 129 malignant cases, the histological tissue acquisition rate per session was similar (100% and 94%), but the sensitivity by histology alone per session was higher for FNB than for FNA (93% and 73%, p<0.01).

Conclusions: The results of our retrospective analysis indicated that compared with a standard FNA needle, a 22-gauge Franseen FNB needle was associated with a higher first-pass tissue acquisition rate.
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http://dx.doi.org/10.5009/gnl19171DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7667934PMC
November 2020

The impact of age and comorbidity in advanced or recurrent biliary tract cancer receiving palliative chemotherapy.

J Gastroenterol Hepatol 2020 Oct 23;35(10):1828-1835. Epub 2020 Apr 23.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

Background And Aim: Limited data are available on age and comorbidity assessment in patients with biliary tract cancer (BTC). This study aimed to evaluate the association of age and comorbidity burden with clinical outcomes of chemotherapy for BTC.

Methods: Consecutive 197 BTC patients undergoing first-line chemotherapy between 2007 and 2017 were retrospectively studied. Patients were classified to three groups according to the age-adjusted Charlson comorbidity index (ACCI) excluding the score about BTC and progression-free survival, overall survival (OS), and safety were compared.

Results: Fifty-one patients (26%) were elderly (≥ 75 years), and ACCI was 0-2 in 73 patients (37%), 3-4 in 98 (50%), and ≥ 5 in 26 (13%). ACCI was associated with the administration of first-line combination chemotherapy (89% in 0-2, 80% in 3-4, and 64% in ≥ 5, P < 0.01) and second-line chemotherapy (67% in 0-2, 51% in 3-4, and 35% in ≥ 5, P = 0.01). ACCI was prognostic for OS in addition to performance status, disease status, and CA19-9: The hazard ratios in ACCI of 3-4 and ≥ 5 were 1.39 and 1.79, compared with ACCI of 0-2 (P = 0.04). While overall safety profile did not differ by ACCI, higher ACCI score group developed Grade 3-4 neutropenia more frequently (26% in 0-2, 42% in 3-4, and 46% in ≥ 5, P = 0.04).

Conclusion: Age and comorbidity burden did affect OS and safety profile in BTC patients undergoing first-line palliative chemotherapy. ACCI can be a simple and useful tool to evaluate the age and comorbidity burden in these patients.
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http://dx.doi.org/10.1111/jgh.15066DOI Listing
October 2020

Lenvatinib-induced acute acalculous cholecystitis in a patient with hepatocellular carcinoma.

Clin J Gastroenterol 2020 Aug 2;13(4):568-571. Epub 2020 Apr 2.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

The patient was a 67-year-old man with advanced hepatocellular carcinoma (HCC) due to chronic hepatitis B. Due to refractoriness to radiofrequency ablation and transcatheter arterial chemoembolization, lenvatinib, a new oral mutikinase inhibitor, was started with a daily dose of 12 mg. However, on day 6 the patient developed acute-onset, right upper quadrant pain associated with fever; laboratory tests revealed leukocytosis and liver dysfunction. CT scan showed the swollen gallbladder with wall thickening with no evidence of gallstones, and the diagnosis of acute acalculous cholecystitis was made. After the resolution of cholecystitis by antibiotics and endoscopic nasogallbladder drainage placement, lenvatinib was resumed at a reduced daily dose of 4 mg. However, acute acalculous cholecystitis recurred, supporting lenvatinib as a cause of acute acalculous cholecystitis. Using the Naranjo adverse drug reaction probability scale, a score of 6 was derived, which indicates that this adverse event was probably caused by lenvatinib. In summary, we present a patient with advanced HCC who underwent repeated episodes of acute acalculous cholecystitis as a rare adverse event associated with lenvatinib.
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http://dx.doi.org/10.1007/s12328-020-01116-5DOI Listing
August 2020

Natural history of asymptomatic bile duct stones and association of endoscopic treatment with clinical outcomes.

J Gastroenterol 2020 Jan 31;55(1):78-85. Epub 2019 Aug 31.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.

Background: Due to increasing opportunities for abdominal imaging studies, bile duct stones are occasionally diagnosed without any symptoms. However, there has been no consensus on the management of asymptomatic bile duct stones. We conducted a retrospective longitudinal cohort study to investigate the natural history of asymptomatic bile duct stones and clinical outcomes according to the timing of endoscopic removal.

Methods: We identified consecutive patients who were diagnosed with asymptomatic common bile duct stones and categorized into those who were followed up with stones in situ (wait-and-see group) and those who received early endoscopic stone removal (intervention group). Cumulative incidence functions of biliary complications were estimated and compared between the groups.

Results: We included 191 patients (114 patients in the wait-and-see group and 77 patients in the intervention group). In the wait-and-see group, the cumulative incidence of biliary complications was 6.1% at 1 year, 11% at 3 years, and 17% at 5 years. Asymptomatic disappearance of stones was observed in 22 patients (19%). Procedure-related adverse events of early endoscopic stone removal of asymptomatic stones were observed in 25 (32%) patients including 4 (5.2%) with severe pancreatitis. The cumulative incidence function of biliary complications did not differ by treatment strategies (P = 0.55).

Conclusions: Biliary complications occurred in a substantial proportion of patients with asymptomatic bile duct stones, but early endoscopic removal appeared to have little effect on the prevention of further biliary complications. Given the risk of procedure-related pancreatitis, the wait-and-see strategy may become a management option of asymptomatic stones.
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http://dx.doi.org/10.1007/s00535-019-01612-7DOI Listing
January 2020

Long-term Risk of Malignancy in Branch-Duct Intraductal Papillary Mucinous Neoplasms.

Gastroenterology 2020 01 29;158(1):226-237.e5. Epub 2019 Aug 29.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

Background & Aims: Long-term outcomes of patients with branch-duct intraductal papillary mucinous neoplasms (IPMNs), particularly those after 5 years of surveillance, have not been fully evaluated in large studies. We analyzed incidences of IPMN-derived carcinoma and concomitant ductal adenocarcinoma (pancreatic ductal adenocarcinoma [PDAC]) over 20 years in a large population of patients.

Methods: We identified 1404 consecutive patients (52% women; mean age, 67.5 years) with a diagnosis of branch-duct IPMN, from 1994 through 2017, at the University of Tokyo in Japan. Using a competing risk analysis, we estimated cumulative incidence of pancreatic carcinoma, overall and by carcinoma type. We used competing risks proportional hazards models to estimate subdistribution hazard ratios (SHRs) for incidences of carcinomas. To differentiate IPMN-derived and concomitant carcinomas, we collected genomic DNA from available paired samples of IPMNs and carcinomas and detected mutations in GNAS and KRAS by polymerase chain reaction and pyrosequencing.

Results: During 9231 person-years of follow-up, we identified 68 patients with pancreatic carcinomas (38 patients with IPMN-derived carcinomas and 30 patients with concomitant PDACs); the overall incidence rates were 3.3%, 6.6%, and 15.0% at 5, 10, and 15 years, respectively. Among 804 patients followed more than 5 years, overall cumulative incidence rates of pancreatic carcinoma were 3.5% at 10 years and 12.0% at 15 years from the initial diagnosis. The size of the IPMN and the diameter of the main pancreatic duct associated with incidence of IPMN-derived carcinoma (SHR 1.85; 95% confidence interval 1.38-2.48 for a 10-mm increase in the IPMN size and SHR 1.56; 95% confidence interval 1.33-1.83 for a 1-mm increase in the main pancreatic duct diameter) but not with incidence of concomitant PDAC.

Conclusions: In a large long-term study of patients with branch-duct IPMNs, we found the 5-year incidence rate of pancreatic malignancy to be 3.3%, reaching 15.0% at 15 years after IPMN diagnosis. We observed heterogeneous risk factor profiles between IPMN-derived and concomitant carcinomas.
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http://dx.doi.org/10.1053/j.gastro.2019.08.032DOI Listing
January 2020

Expression of circular RNA CDR1‑AS in colon cancer cells increases cell surface PD‑L1 protein levels.

Oncol Rep 2019 Oct 19;42(4):1459-1466. Epub 2019 Jul 19.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113‑8655, Japan.

The expression of CDR1‑AS, a representative circular RNA, is closely linked with poor prognosis in gastrointestinal cancers, such as colon, liver, and pancreatic cancers. Although it is well known that CDR1‑AS antagonizes microRNA‑7 function through its sequence similarities in the brain, its biological function and link with the malignant potential of cancer cells remain unclear, partly due to the difficulties of ectopic expression of circular RNAs. In the present study, SW620, a colon cancer cell line that stably expresses CDR1‑AS RNA circularized, was established using the laccase 2 gene cassette, and its biological function associated with malignant behavior was determined. In contrast to previous studies, cell growth or invasion ability was not altered by CDR1‑AS expression. However, the expression levels of CMTM4 and CMTM6, which were recently recognized as critical regulators of PD‑L1 protein expression at the cell surface, were significantly increased. Accordingly, the cell surface PD‑L1 protein levels were increased in CDR1‑AS‑expressing cells. Notably, the effects were not canceled out by overexpressing microRNA‑7, indicating that the increase in cell surface PD‑L1 in CDR1‑AS‑expressing cells was not dependent on microRNA‑7 function. These results indicated that expression of this circular RNA in cancer cells may lead to poor prognosis by increasing cell surface PD‑L1 levels through microRNA‑7‑independent mechanisms.
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http://dx.doi.org/10.3892/or.2019.7244DOI Listing
October 2019

Inhibition of HBV Transcription From cccDNA With Nitazoxanide by Targeting the HBx-DDB1 Interaction.

Cell Mol Gastroenterol Hepatol 2019 24;7(2):297-312. Epub 2018 Oct 24.

Department of Gastroenterology, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.

Background & Aims: Hepatitis B virus (HBV) infection is a major health concern worldwide. Although currently used nucleos(t)ide analogs efficiently inhibit viral replication, viral proteins transcribed from the episomal viral covalently closed circular DNA (cccDNA) minichromosome continue to be expressed long-term. Because high viral RNA or antigen loads may play a biological role during this chronicity, the elimination of viral products is an ultimate goal of HBV treatment. HBV regulatory protein X (HBx) was recently found to promote transcription of cccDNA with degradation of Smc5/6 through the interaction of HBx with the host protein DDB1. Here, this protein-protein interaction was considered as a new molecular target of HBV treatment.

Methods: To identify candidate compounds that target the HBx-DDB1 interaction, a newly constructed split luciferase assay system was applied to comprehensive compound screening. The effects of the identified compounds on HBV transcription and cccDNA maintenance were determined using HBV minicircle DNA, which mimics HBV cccDNA, and the natural HBV infection model of human primary hepatocytes.

Results: We show that nitazoxanide (NTZ), a thiazolide anti-infective agent that has been approved by the FDA for protozoan enteritis, efficiently inhibits the HBx-DDB1 protein interaction. NTZ significantly restores Smc5 protein levels and suppresses viral transcription and viral protein production in the HBV minicircle system and in human primary hepatocytes naturally infected with HBV.

Conclusions: These results indicate that NTZ, which targets an HBV-related viral-host protein interaction, may be a promising new therapeutic agent and a step toward a functional HBV cure.
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http://dx.doi.org/10.1016/j.jcmgh.2018.10.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6357790PMC
May 2019

Pevonedistat, a Neuronal Precursor Cell-Expressed Developmentally Down-Regulated Protein 8-Activating Enzyme Inhibitor, Is a Potent Inhibitor of Hepatitis B Virus.

Hepatology 2019 05 13;69(5):1903-1915. Epub 2019 Mar 13.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan.

Hepatitis B virus (HBV) infection is a major health concern worldwide. To prevent HBV-related mortality, elimination of viral proteins is considered the ultimate goal of HBV treatment; however, currently available nucleos(t)ide analogs rarely achieve this goal, as viral transcription from episomal viral covalently closed circular DNA (cccDNA) is not prevented. HBV regulatory protein X was recently found to target the protein structural maintenance of chromosomes 5/6 (Smc5/6) for ubiquitination and degradation by DDB1-CUL4-ROC1 E3 ligase, resulting in enhanced viral transcription from cccDNA. This ubiquitin-dependent proteasomal pathway requires an additional ubiquitin-like protein for activation, neuronal precursor cell-expressed developmentally down-regulated protein 8 (NEDD8). Here, we show that pevonedistat, a NEDD8-activating enzyme inhibitor, works efficiently as an antiviral agent. Pevonedistat significantly restored Smc5/6 protein levels and suppressed viral transcription and protein production in the HBV minicircle system in in vitro HBV replication models and in human primary hepatocytes infected naturally with HBV. Conclusion: These results indicate that pevonedistat is a promising compound to treat chronic HBV infection.
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http://dx.doi.org/10.1002/hep.30491DOI Listing
May 2019

Inflammation and de-differentiation in pancreatic carcinogenesis.

World J Clin Cases 2018 Dec;6(15):882-891

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.

Pancreatic cancer is a malignancy with an extremely poor prognosis. Chronic pancreatitis is a well-known risk factor for pancreatic cancer. Inflammation is thought to influence carcinogenesis through DNA damage and activation of intracellular signaling pathways. Many transcription factors and signaling pathways co-operate to determine and maintain cell identity at each phase of pancreatic organogenesis and cell differentiation. Recent studies have shown that carcinogenesis is promoted through the suppression of transcription factors related to differentiation. Pancreatitis also demonstrates transcriptional changes, suggesting that multifactorial epigenetic changes lead to impaired differentiation. Taken together, these factors may constitute an important framework for pancreatic carcinogenesis. In this review, we discuss the role of inflammation and de-differentiation in the development of pancreatic cancer, as well as the future of novel therapeutic applications.
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http://dx.doi.org/10.12998/wjcc.v6.i15.882DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6288496PMC
December 2018

Fluid sequestration is a useful parameter in the early identification of severe disease of acute pancreatitis.

J Gastroenterol 2019 Apr 26;54(4):359-366. Epub 2018 Nov 26.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.

Background: Early identification of severe disease of acute pancreatitis (AP) is of critical importance to improve the prognosis. Fluid sequestration (FS), calculated from administrated fluid and fluid output, is a simple prognostic parameter. We examined its utility in the early phase of AP.

Methods: We retrospectively investigated AP patients between January 2009 and April 2017. We compared FS in the first 24 h (FS24) with FS in the first 48 h (FS48) and administrated fluid volume within the first 24 h (FV24). Diagnostic yield for predicting intensive care unit (ICU) admission and persistent organ failure (POF) was assessed using receiver operating characteristic curves. We also evaluated risk factors for developing severe disease of AP.

Results: A total of 400 AP patients were included in the analysis (median age 64 years; male 60%). According to the Japanese severity criteria, 158 patients (40%) were diagnosed as severe disease. The rates of mortality, ICU admission and POF were 0.8%, 4.5% and 7.3%, respectively. FS24 showed a similar predictive accuracy in comparison with FS48 and was superior to FV24 in predicting ICU admission and POF. FS24 ≥ 1.6 L, male sex, presence of systemic inflammatory response syndrome and computed tomography severity index ≥ 3 on admission were independent risk factors for disease progression in AP in the multivariate analysis.

Conclusions: FS24 was a simple and easily calculated parameter with high predictive accuracy for discriminating patients who needed intensive care. Patients with FS24 ≥ 1.6 L had an increased risk of developing severe disease.
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http://dx.doi.org/10.1007/s00535-018-1531-6DOI Listing
April 2019

ISGF3 with reduced phosphorylation is associated with constitutive expression of interferon-induced genes in aging cells.

NPJ Aging Mech Dis 2018 15;4:11. Epub 2018 Nov 15.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-8655 Japan.

During cellular aging, many changes in cellular functions occur. A hallmark of aged cells is secretion of inflammatory mediators, which collectively is referred to as the senescence-associated secretory phenotype (SASP). However, the mechanisms underlying such changes are unclear. Canonically, the expression of interferon (IFN)-stimulated genes (ISGs) is induced by IFNs through the formation of the tripartite transcriptional factor ISGF3, which is composed of IRF9 and the phosphorylated forms of STAT1 and STAT2. However, in this study, the constitutive expression of ISGs in human-derived senescent fibroblasts and in fibroblasts from a patient with Werner syndrome, which leads to premature aging, was mediated mainly by the unphosphorylated forms of STATs in the absence of INF production. Under homeostatic conditions, STAT1, STAT2, and IRF9 were localized to the nucleus of aged cells. Although knockdown of JAK1, a key kinase of STAT1 and STAT2, did not affect ISG expression or IFN-stimulated response element (ISRE)-mediated promoter activities in these senescent cells, knockdown of STAT1 or STAT2 decreased ISG expression and ISRE activities. These results suggest that the ISGF3 complex without clear phosphorylation is required for IFN-independent constitutive ISG transcription in senescent cells.
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http://dx.doi.org/10.1038/s41514-018-0030-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6237867PMC
November 2018

Second-line chemotherapy in patients with advanced or recurrent biliary tract cancer: a single center, retrospective analysis of 294 cases.

Invest New Drugs 2018 12 15;36(6):1093-1102. Epub 2018 Oct 15.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-Ku, Tokyo, 113-8655, Japan.

Purpose The survival benefit of first-line chemotherapy (CT1) for biliary tract cancer (BTC) is now established but the role of second-line chemotherapy (CT2) has not been fully elucidated yet. Methods Consecutive advanced BTC patients receiving CT1 between 2000 and 2016 were retrospectively studied. We investigated the safety and efficacy of CT2, prognostic factors for residual survival after CT1, and explored subgroups who would benefit from CT2. Results Among 294 patients receiving CT1 for advanced BTC, CT2 was given in 139 patients (47%). CT2 provided a response rate of 4%, a disease control rate of 52%, a median progression-free survival of 2.8 and overall survival of 7.7 months, respectively. CT2 was associated with longer residual survival after CT1 (hazard ratio [HR] 0.61, p < 0.01), as well as PS of 0-1 (HR 0.53, p < 0.01), best response to CT1 of PD (HR 1.46, p = 0.01), and CEA ≥5.0 ng/mL (HR 1.69, p < 0.01). The effects of CT2 were homogeneous across almost all subgroups but were more prominent in patients with age ≥ 70 years (HR 0.32, p for interaction =0.02), CA19-9 ≥ 200 IU/mL (HR 0.41, p for interaction = 0.08) and CEA ≥5.0 ng/mL (HR 0.41, p for interaction = 0.06). Conclusions The introduction rate of CT2 was 47%. Although the efficacy of CT2 was modest in terms of tumor response, it was associated with better survival. Further investigations are necessary both to develop more effective regimens and to select patients who will benefit from CT2.
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http://dx.doi.org/10.1007/s10637-018-0670-1DOI Listing
December 2018

Cholangitis complicated by infection of a simple hepatic cyst.

Clin J Gastroenterol 2018 Dec 8;11(6):493-496. Epub 2018 Jun 8.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.

An 87-year-old man was admitted to our hospital due to fever and elevated liver enzymes. Computed tomography (CT) scan revealed bile duct stones with a dilated biliary system, which confirmed the diagnosis of cholangitis. A 12-cm simple hepatic cyst was also seen in the right liver, which had been detected on CT scan 5 years before, and did not change in size. Fever did not subside even after endoscopic biliary drainage and a repeated CT scan showed an enlarged cyst up to 14 cm, suggesting cyst infection. An enlarged hepatic cyst collapsed after percutaneous transhepatic drainage, along with resolution of fever. Simple hepatic cysts are common and most of them are asymptomatic. Infection of simple hepatic cysts is a rare condition and the major entry route is considered as the biliary tract as communication between the biliary tract and cysts is reportedly observed in those cases. However, in our case, no communication was seen on cholangiogram or cystogram on fluoroscopy and bilirubin level of the cyst aspirate was low. Given the fact that patients with cholangitis are rarely complicated by hepatic cyst infection, other routes of bacterial entry to simple hepatic cysts should also be considered.
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http://dx.doi.org/10.1007/s12328-018-0874-0DOI Listing
December 2018

A method for determination of aldosterone in adrenal tributary venous serum by derivatization using Girard P reagent isotopologues followed by LC/ESI-MS/MS.

J Chromatogr B Analyt Technol Biomed Life Sci 2018 Aug 2;1092:106-113. Epub 2018 Jun 2.

Department of Biochemistry, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582, Japan.

The quantification of aldosterone (ALD) in adrenal tributary venous blood serum/plasma combined with the super-selective adrenal venous sampling (ssAVS) technique is recognized as a definitive procedure for differentiation of the forms of primary aldosteronism (PA), identification of the affected segment(s) and operating decision-making. In this study, an enhanced throughput and sensitive method was developed and validated for the quantification of ALD in ssAVS serum samples by liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) combined with derivatization using the Girard P reagent (GP) isotopologues (H- and H-GP). The right and left adrenal serum samples were separately pretreated and derivatized with either isotopologue. The two samples were then combined and injected together for LC/ESI-MS/MS analysis. Based on the mass differences between the isotopologues, the derivatized ALD in the two samples were quantified within a single run. This method enabled the reproducible (intra- and inter-assay relative standard deviations, 6.6% or lower) and accurate (98.2-107.0%) quantification of the serum ALD using a 25-μL sample, and the lower limit of quantification was 1.0 ng/mL. The developed method was used for the analysis of 11 pairs of ssAVS serum samples (total of 22 samples) of patients with ALD-producing adenoma and proven to have a satisfactory applicability; this method enabled the identification of the affected adrenal and the determination of the laterality of PA, and reduced the analysis time to about 2/3 compared to the previous method for 22 samples.
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http://dx.doi.org/10.1016/j.jchromb.2018.06.001DOI Listing
August 2018

Hepatitis B virus pathogenesis: Fresh insights into hepatitis B virus RNA.

World J Gastroenterol 2018 Jun;24(21):2261-2268

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.

Hepatitis B virus (HBV) is still a worldwide health concern. While divergent factors are involved in its pathogenesis, it is now clear that HBV RNAs, principally templates for viral proteins and viral DNAs, have diverse biological functions involved in HBV pathogenesis. These functions include viral replication, hepatic fibrosis and hepatocarcinogenesis. Depending on the sequence similarities, HBV RNAs may act as sponges for host miRNAs and may deregulate miRNA functions, possibly leading to pathological consequences. Some parts of the HBV RNA molecule may function as viral-derived miRNA, which regulates viral replication. HBV DNA can integrate into the host genomic DNA and produce novel viral-host fusion RNA, which may have pathological functions. To date, elimination of HBV-derived covalently closed circular DNA has not been achieved. However, RNA transcription silencing may be an alternative practical approach to treat HBV-induced pathogenesis. A full understanding of HBV RNA transcription and the biological functions of HBV RNA may open a new avenue for the development of novel HBV therapeutics.
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http://dx.doi.org/10.3748/wjg.v24.i21.2261DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5989240PMC
June 2018

DHX9 regulates production of hepatitis B virus-derived circular RNA and viral protein levels.

Oncotarget 2018 Apr 20;9(30):20953-20964. Epub 2018 Apr 20.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan.

Hepatitis B virus (HBV) infection, which is a major health concern worldwide, can lead to liver cirrhosis and hepatocellular carcinoma. Although current nucleos(t)ide analogs efficiently inhibit viral reverse transcription and viral DNA load clinically, episomal viral covalently closed circular DNA (cccDNA) minichromosomes and transcripts from cccDNA continue to be expressed over the long term. We hypothesized that, under these conditions, viral transcripts may have biological functions involved in pathogenesis. Here, we show that the host protein DExH-box helicase 9 (DXH9) is associated with viral RNAs. We also show that viral-derived circular RNA is produced during HBV replication, and the amount is increased by knockdown of the DHX9 protein, which, in turn, results in decreased viral protein levels but does not affect the levels of HBV DNA. These phenomena were observed in the HBV-producing cell culture model and HBV mini-circle model mimicking HBV cccDNA, as well as in human primary hepatocytes infected with HBV. Based on these results, we conclude that, in HBV infection, the RNA binding factor DHX9 is a novel regulator of viral circular RNA and viral protein levels.
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http://dx.doi.org/10.18632/oncotarget.25104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5940377PMC
April 2018

Satellite RNA Increases DNA Damage and Accelerates Tumor Formation in Mouse Models of Pancreatic Cancer.

Mol Cancer Res 2018 08 10;16(8):1255-1262. Epub 2018 May 10.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

Highly repetitive tandem arrays such as satellite sequences in the centromeric and pericentromeric regions of chromosomes, which were previously considered to be silent, are actively transcribed in various biological processes, including cancers. In the pancreas, this aberrant expression occurs even in Kras-mutated pancreatic intraepithelial neoplasia (PanIN) tissues, which are precancerous lesions. To determine the biological role of satellite RNAs in carcinogenesis , we constructed mouse major satellite (MajSAT) RNA-expressing transgenic mice. However, these transgenic mice did not show spontaneous malignant tumor formation under normal breeding. Importantly, however, DNA damage was increased in pancreatic tissues induced by caerulein treatment or high-fat diet, which may be due to impaired nuclear localization of Y-Box Binding Protein 1 (YBX1), a component of the DNA damage repair machinery. In addition, when crossed with pancreas-specific Kras-mutant mice, MajSAT RNA expression resulted in an earlier increase in PanIN formation. These results suggest that aberrant MajSAT RNA expression accelerates oncogenesis by increasing the probability of a second driver mutation, thus accelerating cells to exit from the breakthrough phase to the expansion phase. Aberrant expression of satellite RNAs accelerates oncogenesis through a mechanism involving increased DNA damage. .
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http://dx.doi.org/10.1158/1541-7786.MCR-18-0139DOI Listing
August 2018

No Association of Timing of Endoscopic Biliary Drainage with Clinical Outcomes in Patients with Non-severe Acute Cholangitis.

Dig Dis Sci 2018 07 16;63(7):1937-1945. Epub 2018 Apr 16.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.

Background: Biliary drainage via endoscopic retrograde cholangiopancreatography (ERCP) is the first-line treatment for acute cholangitis. Despite the established effectiveness of urgent biliary drainage in patients with severe acute cholangitis, the indication of this procedure for non-severe acute cholangitis is controversial.

Aims: To assess the safety of elective drainage (≥ 12 h of admission) for non-severe acute cholangitis.

Methods: We retrospectively identified 461 patients with non-severe acute cholangitis who underwent endoscopic biliary drainage. Using linear regression models with adjustment for a variety of potential confounders, we compared elective versus urgent biliary drainage (< 12 h of admission) in terms of clinical outcomes. The primary outcome was the length of stay.

Results: There were 98 and 201 patients who underwent elective and urgent biliary drainage, respectively. The median length of stay was 11 days in both groups (P = 0.52). The timing of ERCP was not associated with length of stay in the multivariable model (P = 0.52). Secondary outcomes including in-hospital mortality and recurrence of cholangitis were not different between the groups.

Conclusions: Elective biliary drainage was not associated with worse clinical outcomes of non-severe acute cholangitis as compared to urgent drainage. Further investigation is warranted to justify the elective drainage for non-severe cholangitis.
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http://dx.doi.org/10.1007/s10620-018-5058-8DOI Listing
July 2018

CA19-9 kinetics during systemic chemotherapy in patients with advanced or recurrent biliary tract cancer.

Cancer Chemother Pharmacol 2017 Dec 16;80(6):1105-1112. Epub 2017 Oct 16.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.

Purpose: The role of carbohydrate antigen 19-9 (CA19-9) kinetics in patients with biliary tract cancer (BTC) receiving chemotherapy remains to be elucidated.

Methods: A total of 185 advanced or recurrent BTC patients receiving a first line chemotherapy between January 2006 and March 2016, were retrospectively studied. Serum CA19-9 was measured at baseline and after two cycles of chemotherapy, and patients were categorized based on CA19-9 response: CA19-9 decrease group (≥ 30% decrease), stable group (< 30% decrease and < 20% increase) and increase group (≥ 20% increase). The associations of CA19-9 response with radiological tumor response, progression-free survival (PFS) and overall survival (OS) were investigated.

Results: There was a statistically significant association between CA19-9 response and radiological tumor responses (p < 0.001). The median PFS and OS were significantly different among three groups according to CA19-9 response: PFS of 8.0, 5.7 and 3.5 months in CA19-9 decrease, stable and increase groups (p < 0.001) and OS of 18.8, 16.0 and 7.5 months in CA19-9 decrease, stable and increase groups, respectively (p < 0.001). Multivariate analyses showed that CA19-9 response was prognostic both of OS and PFS in addition, to CA19-9 at baseline, and performance status.

Conclusion: CA19-9 kinetics after the first two cycles of a first line chemotherapy was a prognostic factor for OS and PFS in patients with advanced and recurrent BTC.
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http://dx.doi.org/10.1007/s00280-017-3456-9DOI Listing
December 2017

RASAL1 is a potent regulator of hepatic stellate cell activity and liver fibrosis.

Oncotarget 2017 Sep 4;8(39):64840-64852. Epub 2017 May 4.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

Liver fibrosis, leading to cirrhosis and liver failure, can occur after chronic liver injury. The transition of hepatic stellate cells (HSCs) from quiescent cells into proliferative and fibrogenic cells is a central event in liver fibrosis. Here, we show that RAS protein activator like-1 (RASAL1), a RAS-GTPase-activating protein, which switches off RAS activity, is significantly decreased during HSC activation, and that HSC activation can be antagonized by forced expression of the RASAL1 protein. We demonstrate that RASAL1 suppresses HSC proliferation by regulating the Ras-MAPK pathway, and that RASAL1 suppresses HSC fibrogenic activity by regulating the PKA-LKB1-AMPK-SRF pathway by interacting with angiotensin II receptor, type 1. We also show that RASAL1-deficient mice are more susceptible to liver fibrosis. These data demonstrate that deregulated RASAL1 expression levels and the affected downstream intracellular signaling are central mediators of perpetuated HSC activation and fibrogenesis in the liver.
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http://dx.doi.org/10.18632/oncotarget.17609DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5630295PMC
September 2017

Transcriptional activation of the MICA gene with an engineered CRISPR-Cas9 system.

Biochem Biophys Res Commun 2017 04 18;486(2):521-525. Epub 2017 Mar 18.

Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

Major histocompatibility complex class I polypeptide-related sequence A (MICA) is a prototypical NKG2D ligand. Because immune cells, such as natural killer (NK) cells, recognize virally infected or transformed cells and eliminate them through the interaction between NKG2D receptors on NK cells and NKG2D ligands on pathogenic cells, MICA expression levels are associated with NK cell-mediated immunity. Here, we report that an engineered clustered regularly interspaced short palindromic repeats-Cas9-related complex targeting MICA gene promoter sequences activates transcription of the MICA gene from its endogenous locus. Inhibiting microRNA function, which targets the 3' untranslated region of the MICA gene, enhances this activation. These results demonstrate that the combination of Cas9-based transcriptional activators and simultaneous modulation of microRNA function may be a powerful tool for enhancing MICA protein expression and efficient anti-pathogenic cell immunity.
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http://dx.doi.org/10.1016/j.bbrc.2017.03.076DOI Listing
April 2017

Vascular endothelial growth factor receptor 1 signaling facilitates gastric ulcer healing and angiogenesis through the upregulation of epidermal growth factor expression on VEGFR1+CXCR4 + cells recruited from bone marrow.

J Gastroenterol 2014 Mar 24;49(3):455-69. Epub 2013 Aug 24.

Department of Pharmacology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa, 252-0374, Japan.

Background: Angiogenesis is essential for gastric ulcer healing. Recent results suggest that vascular endothelial growth factor receptor 1 (VEGFR1), which binds to VEGF, promotes angiogenesis. In the present study, we investigated the role of VEGFR1 signaling in gastric ulcer healing and angiogenesis.

Methods: Gastric ulcers were induced by serosal application of 100 % acetic acid in wild-type (WT) and tyrosine kinase-deficient VEGFR1 mice (VEGFR1 TK(-/-)). Bone marrow transplantation into irradiated WT mice was carried out using bone marrow cells isolated from WT and VEGFR1 TK(-/-) mice.

Results: Ulcer healing was delayed in VEGFR1 TK(-/-) mice compared to WT mice and this was accompanied by decreased angiogenesis, as evidenced by reduced mRNA levels of CD31 and decreased microvessel density. Recruitment of cells expressing VEGFR1 and C-X-C chemokine receptor type 4 (CXCR4) was suppressed and epidermal growth factor (EGF) expression in ulcer granulation tissue was attenuated. Treatment of WT mice with neutralizing antibodies against VEGF or CXCR4 also delayed ulcer healing. In WT mice transplanted with bone marrow cells from VEGFR1 TK(-/-) mice, ulcer healing and angiogenesis were suppressed, and this was associated with reduced recruitment of bone marrow cells to ulcer granulation tissue. VEGFR1 TK(-/-) bone marrow chimeras also exhibited downregulation of EGF expression on CXCR4(+)VEGFR1(+) cells recruited from the bone marrow into ulcer lesions.

Conclusion: VEGFR1-mediated signaling plays a critical role in gastric ulcer healing and angiogenesis through enhanced EGF expression on VEGFR1(+)CXCR4(+) cells recruited from the bone marrow into ulcer granulation tissue.
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http://dx.doi.org/10.1007/s00535-013-0869-zDOI Listing
March 2014

NSAID, aspirin delays gastric ulcer healing with reduced accumulation of CXCR4(+)VEGFR1(+) cells to the ulcer granulation tissues.

Biomed Pharmacother 2013 Sep 7;67(7):607-13. Epub 2013 Jun 7.

Department of Pharmacology, Kitasato University School of Medicine, Kanagawa, Japan; Department of Gastroenteology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami, 252-0374 Sagamihara Kanagawa, Japan.

Background: Ulcer healing is a complex process, which involves cell migration, proliferation, angiogenesis and re-epithelialization. Several growth factors have been implicated in this process but the precise mechanism is not well understood. This study examined the involvement of VEGFR1 signaling in the gastric ulcer healing.

Methods: Gastric ulcers were induced by the serosal application of 100% acetic acid, and the areas of the ulcers were measured thereafter.

Results: The healing of acetic acid induced ulcers and the progenitor cells expressing CXCR4(+)VEGFR1(+) cell were significantly delayed in NSAID treated mice. The areas of the ulcer was significantly suppressed in tyrosine kinase-deficient VEGFR1 mice (VEGFR1TKKO) compared with wild type (WT) mice. The plasma level of SDF-1 and stem cell factor (SCF) and bone marrow level of pro-matrix metallopeptidase 9 (pro-MMP-9) were significantly reduced in VEGFR1TKKO mice. In VEGFR1 TKKOmice, the progenitor cells expressing CXCR4(+)VEGFR1(+) cell from bone marrow and the recruitment of these cells in healing ulcer were suppressed. Furthermore, VEGFR1 TKKO mice treated with NSAID did not suppress gastric ulcer healing compared to vehicle mice. These results suggested that NSAID suppressed VEGFR1 TK signaling plays a critical role in ulcer healing through mobilization of CXCR4(+)VEGFR1(+) cells.

Conclusion: VEGFR1 signaling is required for healing of NSAID induced gastric ulcer and angiogenesis with increased recruitment of CXCR4(+)VEGFR1(+) cells to the ulcerative lesion.
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http://dx.doi.org/10.1016/j.biopha.2013.01.009DOI Listing
September 2013

Angiotensin II type 1A receptor signaling facilitates tumor metastasis formation through P-selectin-mediated interaction of tumor cells with platelets and endothelial cells.

Am J Pathol 2013 Feb 3;182(2):553-64. Epub 2012 Dec 3.

Department of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374, Japan.

Angiotensin II is involved in tumor growth; however, the precise mechanism is not known. Platelets also contribute to tumor growth, and angiotensin II type 1 receptor (AT1) is expressed on the platelet surface. We hypothesized that interaction of platelets with tumor cells through AT1 receptor signaling promotes tumor metastasis. B16F1 melanoma cells were intravenously injected into Agtr1a knockout mice (AT1a(-/-)) and wild-type littermates (WT); the AT1a(-/-) mice exhibited a reduction in lung colonies. Angiotensin II induced expression of P-selectin on platelets in WT but not in AT1a(-/-) mice. A selective P-selectin neutralizing antibody decreased lung colony numbers in WT but not in AT1a(-/-) mice. Levels of vascular endothelial growth factor (VEGF) and stromal cell-derived factor 1 (SDF-1) receptor in platelets at metastatic locus were lower in AT1a(-/-) mice. Treatment of neutralizing antibodies against VEGF and CXCR4 decreased lung colony numbers in WT but not in AT1a(-/-) mice. In AT1a(-/-) mice, and both mobilization of progenitor cells expressing CXCR4(+)VEGFR1(+) cells from bone marrow and their recruitment to lung tissues were suppressed. These results suggest that AT1A signaling plays a critical role in tumor metastasis through P-selectin-mediated interactions of platelets with tumor and endothelial cells and through the AT1A signaling-dependent production of VEGF and SDF-1, which may be involved in mobilization of CXCR4(+)VEGFR1(+) cells.
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http://dx.doi.org/10.1016/j.ajpath.2012.10.026DOI Listing
February 2013

Thromboxane A(2) receptor signaling promotes liver tissue repair after toxic injury through the enhancement of macrophage recruitment.

Toxicol Appl Pharmacol 2012 Feb 21;259(1):104-14. Epub 2011 Dec 21.

Department of Pharmacology, Kitasato University School of Medicine, Kanagawa 252-0374, Japan.

It is thought that thromboxane A(2) (TxA(2)) contributes to the progression of inflammation during acute hepatic injury; however, it is still unknown whether TxA(2) is involved in liver repair. The objective of the present study was to examine the role of TxA(2) receptor (TP) signaling in liver injury and repair in response to toxic injury. Carbon tetrachloride (CCl(4)) was used to induce liver injury in TP knockout (TP(-/-)) mice and wild-type (WT) mice. In WT mice, serum levels of alanine aminotransferase (ALT) and the size of the necrotic area peaked at 24 and 48h, respectively, and then declined. In TP(-/-) mice, the changes in ALT levels were similar to WT mice, but liver regeneration was impaired as evidenced by remained elevated levels of hepatic necrosis and by delayed hepatocyte proliferation, which was associated with the reduced expression of growth factors including interleukin-6 (IL-6), tumor necrosis factor alpha (TNFα), and hepatocyte growth factor (HGF). In TP(-/-) mice, the accumulation of hepatic CD11b(+)/F4/80(+) macrophages in injured livers was attenuated, and the hepatic expression of monocyte chemoattractant protein-1 (MCP-1/CCL2) and its receptor, the C-C chemokine receptor (CCR2), was reduced compared to WT. Additionally, the application of the TP receptor agonist, U-46619, enhanced the expression of MCP-1/CCL2 and CCR2 in peritoneal macrophages, which was associated with increased levels of IL-6, TNFα and HGF. These results suggested that TP receptor signaling facilitates liver recovery following CCl(4)-induced hepatotoxicity by affecting the expression of hepatotrophic growth factors, and through the recruitment of macrophages mediated by MCP-1/CCL2-CCR2 expression.
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http://dx.doi.org/10.1016/j.taap.2011.12.013DOI Listing
February 2012
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