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京都大学 / 新制・課程博士 / 博士(医学) / 甲第23805号 / 医博第4851号 / 新制||医||1058(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 長船 健二, 教授 寺田 智祐, 教授 稲垣 暢也 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Yes / Group I metabotropic glutamate receptor (mGluR) dependent long-term depression (LTD) is a major form of synaptic plasticity underlying learning and memory. The molecular mechanisms involved in mGluR-LTD have been investigated intensively for the last two decades. In this 60th anniversary special issue article, we review the recent advances in determining the mechanisms that regulate the induction, transduction and expression of mGluR-LTD in the hippocampus, with a focus on the mitogen-activated protein kinase (MAPK) pathways. In particular we discuss the requirement of p38 MAPK and extracellular signal-regulated kinase 1/2 (ERK 1/2) activation. The recent advances in understanding the signaling cascades regulating mGluR-LTD are then related to the cognitive impairments observed in neurological disorders, such as fragile X syndrome and Alzheimer's disease.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第25000号 / 医博第5034号 / 新制||医||1070(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 長船 健二, 教授 尾野 亘, 教授 江藤 浩之 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

PURPOSE: The anti-tumor activity of glucose analogs 2-deoxy-glucose (2-DG) and D-allose was investigated alone or in combination with p38 mitogen-activated protein kinase (MAPK) inhibitor SB202190 or platinum analogs as a strategy to pharmacologically target glycolytic tumor phenotypes. METHODS: Hypoxia inducible factor-1 alpha (HIF-1alpha) protein accumulation in pancreatic cell lines treated with SB202190 alone and in combination with glucose analogs was analyzed by Western blot. HIF-1alpha transcriptional activity was measured in MIA PaCa-2 cells stably transfected with a hypoxia response element luciferase reporter following treatment with glucose analogs alone, and in combination with SB202190. Induction of cleaved poly(ADP-ribose) polymerase (PARP) was measured by Western blot in the MIA PaCa-2 cells. In vitro anti-proliferative activity of 2-DG and D-allose alone, or in combination with oxaliplatin (pancreatic cell lines), cisplatin (ovarian cell lines), or with SB202190 were investigated using the MTT assay. RESULTS: SB202190 decreased HIF-1alpha protein accumulation and transcriptional activity. 2-DG demonstrated greater anti-proliferative activity than D-allose. Pre-treatment with SB202190 enhanced activity of both 2-DG and D-allose in MIA PaCa-2, BxPC-3, ASPC-1, and SK-OV-3 cells. The combination of D-allose and platinum agents was additive to moderately synergistic in all but the OVCAR-3 and HEY cells. SB202190 pre-treatment further enhanced activity of D-allose and 2-DG with platinum agents in most cell lines investigated. CONCLUSIONS: SB202190 induced sensitization of tumor cells to 2-DG and D-allose may be partially mediated by inhibition of HIF-1alpha activity. Combining glucose analogs and p38 MAPK inhibitors with chemotherapy may be an effective approach to target glycolytic tumor phenotypes.

Elevated levels of hyaluronan are associated with numerous inflammatory diseases including ulcerative colitis, Crohn's disease and wound healing. Various proinflammatory cytokines have shown to influence hyaluronan expression in cells originating from connective tissue. The overall purposes of this study included: 1. To determine the effects of IL-1β stimulation on HA and HAS2 steady state transcript levels and the signaling pathways involved in its effects. The signaling pathways utilized by proinflammatory mediators to modulate hyaluronan expression have only begun to be elucidated. In this aim, the effects of IL-1β on hyaluronan and HAS expressions in jejunum-derived mesenchymal cells were determined. Inhibition studies were utilized to determine the signaling pathways involved. The overall hypothesis of this aim was that stimulation of jejunum-derived mesenchymal cells with IL-1β activates the mitogen activated protein kinase pathways resulting in increased HAS2 steady state transcript and hyaluronan levels.Results: The results suggest that IL-1β induction of HAS2 expression involves, in part, the mitogen activated protein kinase signaling pathways that act in concert thus leading to an increase in expression of hyaluronan by jejunum-derived mesenchymal cells.2. To determine the effects of dexamethasone on IL-1β mediated increase in hyaluronan and HAS2 expressions and the mechanisms utilized by this glucocorticoid. Glucocorticoids are a mainstay treatment for the inflammatory component of inflammatory bowel disease. Given the recent evidence demonstrating increased hyaluronan in inflamed tissue from patients affected with inflammatory bowel disease, the objective of this aim was to determine the effect of dexamethasone on IL-1β-mediated induction of hyaluronan. The hypothesis of this aim was that pre-treatment with dexamethasone suppressed the ability of IL-1β to increase HAS2 transcript and hyaluronan levels via inhibition of the p38 MAP kinase pathway. Results: Pre-treatment with dexamethasone inhibited IL-1β-mediated hyaluronan and HAS2 induction by blocking the activation of the p38 MAP kinase pathways. 3. To identify the transcriptional and post-transcriptional mechanisms utilized by IL-1β to upregulate HAS2 steady state transcript levels. Very little is known about transcriptional and post-transcriptional regulation of the hyaluronan synthase 2 gene. In this aim, 5' and 3' mapping, luciferase analyses and actinomycin D studies were used to determine the transcriptional and post-transcriptional mechanisms utilized by IL-1β to regulate HAS2 steady state transcript levels. The hypothesis of this aim was that IL-1β used post-transcriptional mechanisms to regulate the HAS2 gene.Results: Dermal fibroblasts were used to find the 5'- and 3'-termini of the HAS2 message. Promoter constructs extending approximately 1 kb upstream from the transcription start site demonstrated no IL-1β response. Blocking protein synthesis prior to the addition of IL-1β dramatically increased HAS2 steady state transcript levels, while inhibition of transcription suppressed the effect of IL-1β on HAS2. Northern blot analysis revealed that cycloheximide and IL-1β exerted differential effects on the two HAS2 transcripts.