{"created":"2021-03-01T06:08:32.276272+00:00","id":4717,"links":{},"metadata":{"_buckets":{"deposit":"41e32699-55f8-4382-bd64-205a6a3473a9"},"_deposit":{"id":"4717","owners":[],"pid":{"revision_id":0,"type":"depid","value":"4717"},"status":"published"},"_oai":{"id":"oai:niigata-u.repo.nii.ac.jp:00004717","sets":["453:455","468:563:564"]},"item_6_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"Studies on the estrogen receptor subtype in avian medullary bone formation"}]},"item_6_biblio_info_6":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2006-03-23","bibliographicIssueDateType":"Issued"},"bibliographicPageEnd":"98","bibliographicPageStart":"1","bibliographic_titles":[{}]}]},"item_6_date_granted_51":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2006-03-23"}]},"item_6_degree_grantor_49":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_name":"新潟大学"}]}]},"item_6_degree_name_48":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士（学術）"}]},"item_6_description_4":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Laying birds have a specific tissue, called medullary bone, for eggshell formation. Medullary bone is developed in the bone marrow cavities of the long bones such as the femur and tibia during the egg laying period. Medullary bone formation is stimulated by estrogen from a theca folliculi. In fact, mature male birds have no medullary bone, but medullary bone can develop in the bone marrow cavities as a result of estrogen treatment. Furthermore, medullary bone formation is inhibited by the treatment of anti-estrogen, tamoxifen, in estrogen-treated male birds. Therefore, medullary bone is a useful model for examining the effect of estrogen on bone formation. The effect of estrogen is mediated by the estrogen receptor (ER) in estrogen-target tissues. Previous immunohistochemical studies have demonstrated that, in medullary bone, ER is localized in osteogenic cells but is not localized in osteoclasts on the medullary bone surface. However, northern blot studies have indicated that ER is expressed in osteoclasts. Therefore, the expression of ER in bone cells is unclear. Moreover, the novel ER subtype, ER β has recently been cloned, and classical ER has been renamed ER α. Consequently, ER has two subtypes, ER α and ER β. In the previous study, expression patterns of ER α and ER β differed in their estrogen target tissues, and previous reports propose that detections of ER α and ER β in the estrogen-target tissues would elucidate the mechanism of the tissue-specific action of estrogen. However, expression of ER α and ER β in the estrogen-target tissue, medullary bone, is unknown. Therefore, the present study investigates whether estrogen is mediated by ER α and/or ER β in medullary bone formation. ER α and ER β mRNA expression in laying hen tissues were detected with semiquantitative-RT-PCR analysis, and ER α mRNA localization in the medullary bone was observed using the in situ hybridization histochemistry. In medullary bone, both ER α and ER β mRNA were expressed, and ER α mRNA expression was higher than ER β mRNA. In the liver, kidney, and shell gland of the oviduct, both ER α and ER β mRNA were expressed, and expression patterns of ER α and ER β differed in each tissue. Furthermore, ER α mRNA was expressed in osteogenic cells such as osteoblasts, osteocytes, and bone marrow stromal cells but was not expressed in osteoclasts. These results suggest that estrogen action may be regulated not by ER β but by ER α in medullary bone. ER α and ER β mRNA expression during medullary bone formation and resorption in estrogen-treated male Japanese quail were detected with semiquantitative-RT-PCR, and localization of ER α mRNA was detected using in situ hybridization histochemistry.","subitem_description_type":"Abstract"},{"subitem_description":"Expression of ER α and ER β mRNA was detected during the time course of medullary bone formation and resorption. ER α mRNA expression increased after a single injection of estrogen and reached a peak at 144  hours after the injection of estrogen. One hundred and forty four hours after the injection of estrogen, the expression of ER α mPNA gradually decreased, and returned to that before the injection of estrogen. On the other hand, the expression of ER β mRNA did not change and remained low during the medullary bone formation and resorption. Furthermore, ER α mRNA was localized in osteoblasts but was not localized in osteoclasts. These results suggest that estrogen may be mediated by ER α in medullary bone formation. A previous report showed that the osteogenic cells displayed alkaline phosphatase activity in estrogen-treated mature male Japanese quail and indicated that estrogen directly affects the proliferation of osteogenic cells in avian bone. Therefore, ER α and ER β mRNA expression in cultured osteogenic cells from medullary bone were detected with semiquantitative-RT-PCR. ER α and ER β mRNA were expressed in the pre-culture and the confluent periods, and ER α mRNA expression increased from the pre-culture to the confluent periods. On the other hand, the expression of ER β mRNA did not change and remained low during the osteogenic cell proliferation periods. These results suggest that estrogen may be mediated by ER α in osteogenic cell proliferation. The medullary bone formation was observed in a histochemical study in selective estrogen receptor agonist-treated male Japanese quail. Medullary bone developed in the bone marrow cavities from the endosteal surface with ER α specific agonist, PPT, treatment. On the other hand, no medullary bone developed on the endosteal surface with ER β specific agonist, DPN, treatment. In the previous study, estrogen induced the differentiation of endosteal cells into osteoblasts on the endosteal surface. However, in DPN treated mature male Japanese quail, the differentiation of endosteal cells was not observed on the endosteal surface. ER α specific agonist, PPT, binds to only ER α, and ER β specific agonist, DPN, binds to only ER β Therefore, the present study demonstrates that in medullary bone formation, the effect of estrogen is mediated by ER α.","subitem_description_type":"Abstract"},{"subitem_description":"本研究では,産卵鶏骨髄骨から分離・培養した骨形成系細胞におけるERαおよびERβのmRNAの発現を検討した.供試動物として骨髄骨の形成が活発に行われている放卵後3時間の白色レグホーン種(約300日齢)を用いた.骨髄骨からの骨形成系細胞の分離は,コラゲナーゼ処理によって行い,24時間前培養した.前培養後,分離した骨形成系細胞はconfluentに達するまで培養を続けた.前培養後およびconfluent期の骨形成系細胞におけるERαおよびERβのmRNAの発現量を検討するため,前培養後およびconfluent期の骨形成系細胞から総RNAを抽出し,半定量的RT-PCR法を用いて検討した.その結果,前培養後およびconfluent期の両方の骨形成系細胞には,これらのmRNAの発現がみられるとともに,ERαmRNAの発現はERβmRNAより低い発現だった.さらに,ERαmRNAは前培養後からconfluent期にかけて増加した.一方ERβmRNAの発現は,大きな変化がみられなかった．これらのことから,骨髓骨から分離・培養した骨形成系細胞の増殖には,エストロジェンがERαを介して作用している可能性が示唆された． 本研究では,骨髄骨におけるERαおよびERβの役割を検討することを目的とし,成熟した雄ウズラに選択的エストロジェン受容体アゴニストを投与し,骨髄骨形成においてエストロジェンがERαおよびERβのどちらを介して作用しているのか検討した.供試動物として,14週齢の成熟した雄ウズラを用いた.選択的エ.ストロジェン受容体アゴニストは,ERαのみに対するアゴニストとしてPPTを,ERβのみに対するアゴニストとしてDPNをそれぞれ用いた.これらのアゴニストは,DMSOで溶解した後,供試動物の浅胸筋へ体重100gあたり1mgの割合で3日間連続投与した.また,DMSOのみ投与したものを対照とした.骨髄骨の形成は,投与終了3日後に大腿骨を採取し,大腿骨骨幹部の横断切片を作製し,アルシアンブルー染色を施して観察した.その結果PPT投与区において,皮質骨骨内膜表面から骨髄腔に向けて網状に発達したアルシアンブルー陽性の骨髄骨が観察された.一方DPN投与区は,骨髄骨はみられず対照区と同様であった.PPTはERαのみに対し結合してアゴニスト作用を示すとともにDPNはERβのみに対し結合してアゴニスト作用を示す働きを有していることから,骨髄骨形成においてエストロジェンはERαを介して作用していることが示唆された.","subitem_description_type":"Abstract"}]},"item_6_description_5":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"新大院博（学）甲第168号","subitem_description_type":"Other"}]},"item_6_description_53":{"attribute_name":"学位記番号","attribute_value_mlt":[{"subitem_description":"新大院博（学）甲第168号","subitem_description_type":"Other"}]},"item_6_dissertation_number_52":{"attribute_name":"学位授与番号","attribute_value_mlt":[{"subitem_dissertationnumber":"13101甲第2644号"}]},"item_6_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"48957","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Imamura, Tomohiko"}]}]},"item_6_publisher_7":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"新潟大学大学院自然科学研究科"}]},"item_6_select_19":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_select_item":"author"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"今村, 友彦"}],"nameIdentifiers":[{"nameIdentifier":"48956","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2019-08-05"}],"displaytype":"detail","filename":"13_0021.pdf","filesize":[{"value":"12.8 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"本文","url":"https://niigata-u.repo.nii.ac.jp/record/4717/files/13_0021.pdf"},"version_id":"6478bdfd-29ab-46d2-bdbf-c7839a8ec166"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"Medullary bone","subitem_subject_scheme":"Other"},{"subitem_subject":"Estrogen receptor","subitem_subject_scheme":"Other"},{"subitem_subject":"骨髄骨","subitem_subject_language":"en","subitem_subject_scheme":"Other"},{"subitem_subject":"エストロジェン受容体","subitem_subject_language":"en","subitem_subject_scheme":"Other"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"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":"鳥類骨髄骨形成におけるエストロジェン受容体サブタイプに関する研究","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"鳥類骨髄骨形成におけるエストロジェン受容体サブタイプに関する研究"},{"subitem_title":"鳥類骨髄骨形成におけるエストロジェン受容体サブタイプに関する研究","subitem_title_language":"en"}]},"item_type_id":"6","owner":"1","path":["455","564"],"pubdate":{"attribute_name":"公開日","attribute_value":"2007-04-23"},"publish_date":"2007-04-23","publish_status":"0","recid":"4717","relation_version_is_last":true,"title":["鳥類骨髄骨形成におけるエストロジェン受容体サブタイプに関する研究"],"weko_creator_id":"1","weko_shared_id":2},"updated":"2022-12-15T03:37:32.650574+00:00"}