Kumamoto University , abbreviated to Kumadai , is a Japanese public university located in Kumamoto, Kumamoto prefecture in the Kyushu region of Japan. It was established on May 31, 1949, at which time the following institutions were subsumed into it; Kumamoto Teachers College , Kumamoto Pharmaceutical College , the Fifth High School , Kumamoto Medical College , and Kumamoto Technical College . Currently, the university has seven faculties and eight graduate schools with a total of around 10,000 Japanese students and 400 international students from Asia, North America, South America, Europe, Africa, and Oceania. Wikipedia.
Mwimanzi P.,Kumamoto University
Retrovirology | Year: 2011
Although HIV can infect several cellular subsets, such as CD4 T lymphocytes and macrophages, it remains unclear whether an HIV infection in macrophages supports cytotoxic T lymphocyte (CTL) escape. Here, we tested two naturally-arising mutations located in the well-conserved polyproline region of Nef for their effects on CTL recognition, Nef's functionality, and viral replication capacity in macrophages. These mutations were selected because they are known to cause CTL escape in the context of T lymphocytes. Monocyte-derived macrophages (MDMs) infected with the wild-type virus, but not with variant viruses, were efficiently killed by CTL clones targeting Nef epitopes, VY8 (VPLRPMTY) and RY11 (RPQVPLRPMTY). The CTL-escape mutation, ArgThr, or ArgThr/TyrPhe double mutation, reduced the HLA class I down-regulation activity and, interestingly, increased the susceptibility of virus-infected MDMs to recognition by CTLs targeting a different epitope. The same mutations reduced the CCR5, but not CD4, down-regulation activity. Moreover, the Nef variants were impaired for Hck activation and enhancement of viral replication in MDMs. These results suggest that HIV-infected MDMs are killed by CTLs targeting Nef epitopes, contributing to selection and adaptation of CTL-escape viral variants.
Taki K.,Kumamoto University
Oncogene | Year: 2015
Intraductal papillary mucinous neoplasm (IPMN), the most common pancreatic cystic neoplasm, is known to progress to invasive ductal adenocarcinoma. IPMNs commonly harbor activating somatic mutations in GNAS and KRAS, primarily GNASR201H and KRASG12D. GNAS encodes the stimulatory G-protein α subunit (Gsα) that mediates a stimulatory signal to adenylyl cyclase to produce cyclic adenosine monophosphate (cAMP), subsequently activating cAMP-dependent protein kinase A. The GNASR201H mutation results in constitutive activation of Gsα. To study the potential role of GNAS in pancreatic tumorigenesis in vivo, we generated lines of transgenic mice in which the transgene consisted of Lox-STOP-Lox (LSL)-GNASR201H under the control of the CAG promoter (Tg(CAG-LSL-GNAS)). These mice were crossed with pancreatic transcription factor 1a (Ptf1a)-Cre mice (Ptf1aCre/+), generating Tg(CAG-LSL-GNAS);Ptf1aCre/+ mice. This mouse line showed elevated cAMP levels, small dilated tubular complex formation, loss of acinar cells and fibrosis in the pancreas; however, no macroscopic tumorigenesis was apparent by 2 months of age. We then crossed Tg(CAG-LSL-GNAS);Ptf1aCre/+ mice with LSL-KrasG12D mice, generating Tg(CAG-LSL-GNAS);LSL-KrasG12D;Ptf1aCre/+ mice. We used these mice to investigate a possible cooperative effect of GNASR201H and KrasG12D in pancreatic tumorigenesis. Within 5 weeks, Tg(CAG-LSL-GNAS);LSL-KrasG12D;Ptf1aCre/+ mice developed a cystic tumor consisting of marked dilated ducts lined with papillary dysplastic epithelia in the pancreas, which closely mimicked the human IPMN. Our data strongly suggest that activating mutations in GNAS and Kras cooperatively promote murine pancreatic tumorigenesis, which recapitulates IPMN. Our mouse model may serve as a unique in vivo platform to find biomarkers and effective drugs for diseases associated with GNAS mutations.Oncogene advance online publication, 10 August 2015; doi:10.1038/onc.2015.294. © 2015 Macmillan Publishers Limited
Indo Y.,Kumamoto University
Clinical Genetics | Year: 2012
Congenital insensitivity to pain with anhidrosis (CIPA) is an autosomal recessive genetic disorder characterized by insensitivity to pain, anhidrosis (the inability to sweat) and mental retardation. Nerve growth factor (NGF) is a well-known neurotrophic factor essential for the survival and maintenance of NGF-dependent neurons, including primary afferent neurons with thin fibers and sympathetic postganglionic neurons, during development. NGF is also considered to be an inflammatory mediator associated with pain, itch and inflammation in adults. CIPA results from loss-of-function mutations in the NTRK1 gene-encoding TrkA (tropomyosin-related kinase A), a receptor tyrosine kinase for NGF. Defects in NGF-TrkA signal transduction lead to the failure of survival of various NGF-dependent neurons. As a result, patients with CIPA lack NGF-dependent neurons. Recent studies have revealed that mutations in the NGFB gene-encoding NGF protein also cause congenital insensitivity to pain. Using the pathophysiology of CIPA as a foundation, this review investigates the ways in which NGF-dependent neurons contribute to interoception, homeostasis and emotional responses and, together with the brain, immune and endocrine systems, play crucial roles in pain, itch and inflammation. The NGF-TrkA system is essential for the establishment of neural networks for interoception, homeostasis and emotional responses. These networks mediate reciprocal communication between the brain and the body in humans. © 2012 John Wiley & Sons A/S.
Mima K.,Kumamoto University
Journal of hepato-biliary-pancreatic sciences | Year: 2013
Local ablation therapy (LAT) is a widely used treatment for hepatocellular carcinoma (HCC) because it is less invasive than hepatic resection. The precise molecular mechanism underlying local HCC recurrence after LAT is largely unknown. The CD44 standard isoform (CD44s) is involved in epithelial-mesenchymal transition (EMT) in HCC. We investigate the significance of CD44s expression and EMT expression profile in local HCC recurrence after LAT. We studied the expression levels of CD44s, EMT expression profile (E-cadherin(low)/vimentin(high) expression) and their association with clinicopathological factors in 30 HCC samples from patients with locally recurrent HCCs after LAT following hepatic resection. The alterations of CD44s expression was compared with those in initial HCCs from 150 patients without prior any anticancer treatment including LAT. A high CD44s expression was significantly associated with the EMT expression profile (P = 0.002), and it was also detected with a higher frequency in the locally recurrent HCCs after LAT compared to initial HCCs (P < 0.001). In addition, high CD44s expression was associated with the intrahepatic dissemination of HCC after LAT (P = 0.006). These results suggest that high CD44s expression is associated with the aggressive recurrence pattern via EMT after LAT for HCC.
Coronary vasomotor response to intracoronary acetylcholine injection, clinical features, and long-term prognosis in 873 consecutive patients with coronary spasm: analysis of a single-center study over 20 years.
Sato K.,Kumamoto University
Journal of the American Heart Association | Year: 2013
The aim of this study was to elucidate the correlation between angiographic coronary vasomotor responses to intracoronary acetylcholine (ACh) injection, clinical features, and long-term prognosis in patients with vasospastic angina (VSA). This is a retrospective, observational, single-center study of 1877 consecutive patients who underwent ACh-provocation test between January 1991 and December 2010. ACh-provoked coronary spasm was observed in 873 of 1637 patients included in the present analysis. ACh-positive patients were more likely to be older male smokers with dyslipidemia, to have a family history of ischemic heart disease, and to have a comorbidity of coronary epicardial stenosis than were ACh-negative patients. ACh-positive patients were divided into 2 groups: those with focal (total or subtotal obstruction, n=511) and those with diffuse (severe diffuse vasoconstriction, n=362) spasm patterns. Multivariable logistic regression analysis identified female sex and low comorbidity of coronary epicardial stenosis to correlate with the ACh-provoked diffuse spasm pattern in patients with VSA. Kaplan-Meier survival curve indicated better 5-year survival rates free from major adverse cardiovascular events in patients with diffuse spasm pattern compared with those with focal spasm pattern (P=0.019). Multivariable Cox hazard regression analysis identified diffuse spasm pattern as a negative predictor of major adverse cardiovascular events in patients with VSA. ACh-induced diffuse coronary spasm was frequently observed in female VSA patients free of severe coronary epicardial stenosis and was associated with better prognosis than focal spasm. These results suggest the need to identify the ACh-provoked coronary spasm subtypes in patients with VSA.