{"created":"2023-06-20T13:23:18.163498+00:00","id":4093,"links":{},"metadata":{"_buckets":{"deposit":"f8d234f0-beb9-4202-9027-ab7fca6de4ae"},"_deposit":{"created_by":21,"id":"4093","owners":[21],"pid":{"revision_id":0,"type":"depid","value":"4093"},"status":"published"},"_oai":{"id":"oai:ir.soken.ac.jp:00004093","sets":["2:430:22"]},"author_link":["2321","2319","2320"],"item_1_creator_2":{"attribute_name":"著者名","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"高山, 靖規"}],"nameIdentifiers":[{}]}]},"item_1_creator_3":{"attribute_name":"フリガナ","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"タカヤマ, ヤスノリ"}],"nameIdentifiers":[{}]}]},"item_1_date_granted_11":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2013-03-22"}]},"item_1_degree_grantor_5":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_name":"総合研究大学院大学"}]}]},"item_1_degree_name_6":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士（理学）"}]},"item_1_description_12":{"attribute_name":"要旨","attribute_value_mlt":[{"subitem_description":"Transient receptor potential vanilloid 4 (TRPV4) is a non-selective cation channel known to be a sensor\nfor hypo-osmolality, cell swelling, warm temperatures and some chemical compounds. Furthermore,\nthe physiological significance of TRPV4 has attracted a great deal of attention, particularly its\nheat-sensitive properties. Previous reports showed the physiological functions of TRPV4 in several\ncell types, including skin, esophageal keratinocytes and hippocampal neurons. For instance, TRPV4\nexpressed in skin keratinocytes contributes to the enhancement of the skin barrier function at body\ntemperature. Moreover, the release of ATP from esophageal keratinocytes or bladder epithelium is\nenhanced by extension-mediated TRPV4 activation. Additionally, neural activity increases with a rise\nin temperature in hippocampal neurons. However, the precise function of TRPV4 in the brain is still\nunknown except for regulation of neural activity in the hippocampus. In this study, the highest\nexpression of TRPV4 in choroid plexus epithelial cells (CPECs) was found using in situ hybridization,\nimmunohistochemistry and EGFP expression in transgenic mice in which EGFP was expressed in\nTRPV4-positive cells. In addition, calcium-activated chloride currents were observed for the first time\nin CPECs. Moreover, expression of anoctamin 1 (Ano1), Ano4, Ano6 and Ano10 genes in the choroid\nplexus was found by RT-PCR. These data suggest that upon TRPV4 activation, calcium entering\nCPECs enhances production of cerebrospinal fluid (CSF), a process dependent upon ion transports.\nTo investigate this hypothesis, whole-cell patch-clamp recordings in HEK293T cells were performed.\nANO1-mediated chloride currents were dramatically increased in HEK293T cells expressing mouse\nTRPV4 and mouse ANO1 when TRPV4 was activated by a low concentration of GSK1016790A\n(GSK). In contrast, the GSK-induced chloride currents were not significantly affected in the cells\nexpressing ANO4, ANO6 or ANO10 with TRPV4. Additionally, the GSK-induced chloride currents\nin the cells expressing ANO1 and TRPV4 were not observed in the absence of extracellular calcium.\nThese results indicated that chloride efflux through ANO1 depended on TRPV4 activity. Similar\nGSK-induced chloride currents were observed in CPECs isolated from the lateral and the fourth\nventricle choroid plexus. Interestingly, the GSK-induced chloride currents were strongly inhibited by\nan ANO1/ANO2 blocker, T16Ainh-A01 (A01), and ANO2 expression was not suggested in choroid\nplexus. These results indicated a functional linkage between TRPV4 and ANO1 in CPECs. This is\nthe first reported case of the linkage of these two proteins in native cells. It was recently reported that\nANO1 is activated by noxious heat. In the author’s study, ANO1 was activated by heat in the range of\nbody temperature. Heat-evoked chloride currents were also observed in CPECs isolated from\nwild-type (WT) and TRPV4-deficient (TRPV4KO) mice. Furthermore, heat-evoked currents were\ndrastically enhanced after GSK application in WT, but not in TRPV4KO CPECs. These results\nindicated the possibility that heat-sensitivity of ANO1 is enhanced by TRPV4 activation in CPECs.\nHowever, the enhanced currents were not completely blocked by A01. Thus, the possibility of another\nheat-activated chloride channels also was suggested in CPECs.\nAccordingly, the author proposes a concept that functional linkage between TRPV4 and ANO1\nenhances CSF production. First, the apical membrane of CPECs is extended by water influx from the\nbasolateral side. Second, phospholipase A2 (PLA2) activity is increased by the extension of the plasma\nmembrane and arachidonic acid is produced from phospholipids by the activated PLA2. Then,\narachidonic acid is metabolized to epoxyeicosatrienoic acid (EET) by cytochrome P450 epoxygenase\nactivity, and TRPV4 is activated by EET at body temperature. The TRPV4 activation leads to calcium\ninflux, which in turn leads to ANO1 activation at body temperature. Finally, water efflux from CPECs\nis driven by efflux of chloride and some cations through a Donnan equilibrium. Production, transport\nand reabsorption of CSF are important for the maintenance of the brain environment in fetuses and\nadults. Among the three CSF-related events, the principle role of CPECs is CSF production. CSF\ntransport is controlled by ependymal cells and the reabsorption is done by arachnoid granulation to the\ndural venous sinuses. Dysfunction of ciliary motility and the failure of cilia development of\nependymal cells induce severe hydrocephalus. This indicates that CSF is continuously secreted from\nCPECs and the production is independent of the changes in brain pressure. There are currently only\npalliative therapies for hydrocephalus including external ventricular drainage or placement of a surgical\nshunt. Control of CSF production through regulation of TRPV4 activity could allow a safer way to\ntreat those diseases. Thus, these studies suggest a fundamental new therapy for hydrocephalus caused\nby choroid plexus cysts and choroid plexus papillomas.","subitem_description_type":"Other"}]},"item_1_description_7":{"attribute_name":"学位記番号","attribute_value_mlt":[{"subitem_description":"総研大甲第1613号 ","subitem_description_type":"Other"}]},"item_1_select_14":{"attribute_name":"所蔵","attribute_value_mlt":[{"subitem_select_item":"有"}]},"item_1_select_8":{"attribute_name":"研究科","attribute_value_mlt":[{"subitem_select_item":"生命科学研究科"}]},"item_1_select_9":{"attribute_name":"専攻","attribute_value_mlt":[{"subitem_select_item":"20 生理科学専攻"}]},"item_1_text_10":{"attribute_name":"学位授与年度","attribute_value_mlt":[{"subitem_text_value":"2012"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"TAKAYAMA, Yasunori ","creatorNameLang":"en"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2016-02-26"}],"displaytype":"simple","filename":"甲1613_要旨.pdf","filesize":[{"value":"358.8 kB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"要旨・審査要旨","url":"https://ir.soken.ac.jp/record/4093/files/甲1613_要旨.pdf"},"version_id":"a6ee898e-2897-4790-90b0-f5b1a4602343"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2016-02-17"}],"displaytype":"simple","filename":"甲1613_本文.pdf","filesize":[{"value":"9.3 MB"}],"format":"application/pdf","licensetype":"license_11","mimetype":"application/pdf","url":{"label":"本文","url":"https://ir.soken.ac.jp/record/4093/files/甲1613_本文.pdf"},"version_id":"c1d569e5-7fd1-472a-a849-c370a9462fcb"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"thesis","resourceuri":"http://purl.org/coar/resource_type/c_46ec"}]},"item_title":"Functional linkage between TRPV4 and calcium-activated chloride channels in choroid plexus epithelial cells","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Functional linkage between TRPV4 and calcium-activated chloride channels in choroid plexus epithelial cells"},{"subitem_title":"Functional linkage between TRPV4 and calcium-activated chloride channels in choroid plexus epithelial cells","subitem_title_language":"en"}]},"item_type_id":"1","owner":"21","path":["22"],"pubdate":{"attribute_name":"公開日","attribute_value":"2013-11-26"},"publish_date":"2013-11-26","publish_status":"0","recid":"4093","relation_version_is_last":true,"title":["Functional linkage between TRPV4 and calcium-activated chloride channels in choroid plexus epithelial cells"],"weko_creator_id":"21","weko_shared_id":21},"updated":"2023-06-20T15:14:36.164616+00:00"}