http://news.yam.com/afp/life/200711/20071121973231.html
（法新社芝加哥二十日電）美日研究團隊已成功讓人類皮膚細胞轉變成幹細胞，有朝一日或許能提供與複製胚胎相同醫療效益，卻不會引發倫理道德爭議。這項新技術，一旦改良完善後，最終將可讓醫生製作與特定病患遺傳基因完全相符的幹細胞，免除排斥的風險。
此外，由於科學家將能更容易取得幹細胞展開研究，這項研究突破也能快速促進治療癌症、阿滋海默氏症、中風和心臟病等疾病的研究進展。
這項新研究採用的「直接重新編程」技術，可規避一大堆倫理、政治和實務障礙，這些障礙妨礙了藉由複製胚胎製作人類幹細胞的各種嘗試。
知悉這項研究工作的科學家表示，仍存在諸多科學疑慮，繼續追求複製策略依然至關重要，但這項新突破是一項重大成就。
這項新研究突破分別發表在「細胞」和「科學」期刊網路版。
兩個研究團隊均報告指出，已在一連串實驗室試驗中，成功製作出宛如幹細胞的細胞。
美日研究團隊在新研究中，選擇來自組織提供者的不同細胞。日本研究團隊操控來自一名三十六歲婦女的顏面細胞，美國研究團隊則使用新生兒的包皮細胞。
美日兩團隊基本上採用相同技術，都是利用病毒將四個基因插入皮膚細胞內，這些特定基因已知能啟動和關閉其他基因，但到底如何產生出類似胚胎幹細胞性能的細胞依然成謎。
這項新研究成就顯示，直接重新編程技術也能產生與當事人在遺傳上完全相符的多功能細胞，但卻能避免複製方式可能引發的諸多問題。
科學家成功讓人類皮膚細胞變成幹細胞
版主: 版主021
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銀色大道
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- 註冊時間: 週二 5月 15, 2007 10:50 am
Producing primate embryonic stem cells by somatic cell nuclear transfer
Derivation of embryonic stem (ES) cells genetically identical to a patient by somatic cell nuclear transfer (SCNT) holds the potential to cure or alleviate the symptoms of many degenerative diseases while circumventing concerns regarding rejection by the host immune system. However, the concept has only been achieved in the mouse, whereas inefficient reprogramming and poor embryonic development characterizes the results obtained in primates. Here, we used a modified SCNT approach to produce rhesus macaque blastocysts from adult skin fibroblasts, and successfully isolated two ES cell lines from these embryos. DNA analysis confirmed that nuclear DNA was identical to donor somatic cells and that mitochondrial DNA originated from oocytes. Both cell lines exhibited normal ES cell morphology, expressed key stem-cell markers, were transcriptionally similar to control ES cells and differentiated into multiple cell types in vitro and in vivo. Our results represent successful nuclear reprogramming of adult somatic cells into pluripotent ES cells and demonstrate proof-of-concept for therapeutic cloning in primates.
Methods Summary
A primary culture of fibroblasts was established from a skin biopsy of an adult rhesus macaque male (male 1) and prepared for SCNT as previously described9. Mature metaphase II oocytes were rendered spindle-free using the Oosight imaging system (CRI, Inc.) and a donor somatic cell nucleus was introduced into a cytoplast through electrofusion. Reconstructed embryos were activated 2 h after fusion by exposure to 5 M ionomycin (CalBiochem) for 5 min followed by a 5-h incubation in 2 mM 6-dimethylaminopurine (DMAP), placed in HECM-9 medium and cultured at 37 °C in 6% CO2, 5% O2 and 89% N2 until the expanded blastocyst stage. The ICMs of selected SCNT blastocysts were plated onto MEF feeder layers and cultured in ES cell culture medium for 5–7 days. ICMs that attached to the feeder layer and initiated outgrowth were manually dissociated into small clumps with a microscalpel and replated onto fresh MEFs. After the first passage, colonies with ES-cell-like morphology were selected for further propagation, characterization, low-temperature storage and in vitro and in vivo differentiation, as previously described17.
reference: J. A. Byrne1,5, D. A. Pedersen1, L. L. Clepper1, M. Nelson3, W. G. Sanger3, S. Gokhale3, D. P. Wolf1 & S. M. Mitalipov1,2
Oregon National Primate Research Center and,
Oregon Stem Cell Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
Munroe-Meyer Institute, 985450 Nebraska Medical Center, Omaha, Nebraska 68198, USA
Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
Present address: Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Palo Alto, California 94304, USA.
Correspondence to: S. M. Mitalipov1,2 Correspondence and requests for materials should be addressed to S.M.M. (Email: mitalipo@ohsu.edu).
(頭暈目眩)
Derivation of embryonic stem (ES) cells genetically identical to a patient by somatic cell nuclear transfer (SCNT) holds the potential to cure or alleviate the symptoms of many degenerative diseases while circumventing concerns regarding rejection by the host immune system. However, the concept has only been achieved in the mouse, whereas inefficient reprogramming and poor embryonic development characterizes the results obtained in primates. Here, we used a modified SCNT approach to produce rhesus macaque blastocysts from adult skin fibroblasts, and successfully isolated two ES cell lines from these embryos. DNA analysis confirmed that nuclear DNA was identical to donor somatic cells and that mitochondrial DNA originated from oocytes. Both cell lines exhibited normal ES cell morphology, expressed key stem-cell markers, were transcriptionally similar to control ES cells and differentiated into multiple cell types in vitro and in vivo. Our results represent successful nuclear reprogramming of adult somatic cells into pluripotent ES cells and demonstrate proof-of-concept for therapeutic cloning in primates.
Methods Summary
A primary culture of fibroblasts was established from a skin biopsy of an adult rhesus macaque male (male 1) and prepared for SCNT as previously described9. Mature metaphase II oocytes were rendered spindle-free using the Oosight imaging system (CRI, Inc.) and a donor somatic cell nucleus was introduced into a cytoplast through electrofusion. Reconstructed embryos were activated 2 h after fusion by exposure to 5 M ionomycin (CalBiochem) for 5 min followed by a 5-h incubation in 2 mM 6-dimethylaminopurine (DMAP), placed in HECM-9 medium and cultured at 37 °C in 6% CO2, 5% O2 and 89% N2 until the expanded blastocyst stage. The ICMs of selected SCNT blastocysts were plated onto MEF feeder layers and cultured in ES cell culture medium for 5–7 days. ICMs that attached to the feeder layer and initiated outgrowth were manually dissociated into small clumps with a microscalpel and replated onto fresh MEFs. After the first passage, colonies with ES-cell-like morphology were selected for further propagation, characterization, low-temperature storage and in vitro and in vivo differentiation, as previously described17.
reference: J. A. Byrne1,5, D. A. Pedersen1, L. L. Clepper1, M. Nelson3, W. G. Sanger3, S. Gokhale3, D. P. Wolf1 & S. M. Mitalipov1,2
Oregon National Primate Research Center and,
Oregon Stem Cell Center, Oregon Health & Science University, 505 N.W. 185th Avenue, Beaverton, Oregon 97006, USA
Munroe-Meyer Institute, 985450 Nebraska Medical Center, Omaha, Nebraska 68198, USA
Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA
Present address: Stanford Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Palo Alto, California 94304, USA.
Correspondence to: S. M. Mitalipov1,2 Correspondence and requests for materials should be addressed to S.M.M. (Email: mitalipo@ohsu.edu).
(頭暈目眩)
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銀色大道
- V2
- 文章: 2168
- 註冊時間: 週二 5月 15, 2007 10:50 am
胚胎幹細胞可以分化成各種器官組織。長期以來，科學家一直希望找出方法製造出這種在遺傳上與病患完全相符的幹細胞，因為這或許能夠成為治療疾病與身體損傷的新方法。
他們透過複製來製造幹細胞，這必須利用胚胎。但現在透過「直接重新編程」，科學家找到新方法，可以製造出看起來與幹細胞幾乎一模一樣的細胞，而不必動用到胚胎。以下是這項技術的問與答。
問：這是多大的突破？
答：非常大。一位研究人員將此比喻為萊特兄弟發明飛機。複製出桃莉羊的科學家韋莫特說，他不再使用複製來製造幹細胞，開始測試這種新方法。
問：這項新方法有什麼好處？
答：可供研究使用的人類卵子相當缺乏，而這項新方法不需要用到女性未受精的卵子來取得胚胎，也不用摧毀胚胎，因為要取得幹細胞必須從胚胎中獲得，而某些團體基於道德與宗教理由，反對這種複製方法。
問：這是否代表科學家不再需要人類卵子或胚胎？
答：並非如此。科學家表示應該繼續利用胚胎幹細胞進行研究，但這項新發現可以降低胚胎幹細胞研究的需求。
問：新方法如何進行？
答：在皮膚細胞中插入四個基因。科學家知道，這些特定的基因可啟動或關閉其他基因，這些基因組合可將皮膚細胞轉變為類似幹細胞，但究竟如何達成仍是個謎。
問：這些細胞就是所謂的「成體幹細胞」？
答：不是。所謂成體幹細胞可在人體內發現，已具備轉變成各類細胞的能力，不需要再插入四個基因。
問：這種新方法是否有任何缺點？
答：初期階段使用這項技術會干擾皮膚細胞的DNA，可能引發癌症。以此方式製作幹細胞作為疾病治療的方法目前仍無法被接受。但DNA遭干擾只是這項技術的副產物，專家相信會有預防之道。
問：這對於一般人的意義何在？我們可以預期很快出現新的治療方法嗎？
答：幾年內還不行。除了克服癌症障礙，科學家還必須解決這些細胞的基本問題。在醫學方面，科學家可先利用這些細胞從事實驗室研究，例如篩檢可能的藥物。
http://money.chinatimes.com/q_news/961121000012.htm
他們透過複製來製造幹細胞，這必須利用胚胎。但現在透過「直接重新編程」，科學家找到新方法，可以製造出看起來與幹細胞幾乎一模一樣的細胞，而不必動用到胚胎。以下是這項技術的問與答。
問：這是多大的突破？
答：非常大。一位研究人員將此比喻為萊特兄弟發明飛機。複製出桃莉羊的科學家韋莫特說，他不再使用複製來製造幹細胞，開始測試這種新方法。
問：這項新方法有什麼好處？
答：可供研究使用的人類卵子相當缺乏，而這項新方法不需要用到女性未受精的卵子來取得胚胎，也不用摧毀胚胎，因為要取得幹細胞必須從胚胎中獲得，而某些團體基於道德與宗教理由，反對這種複製方法。
問：這是否代表科學家不再需要人類卵子或胚胎？
答：並非如此。科學家表示應該繼續利用胚胎幹細胞進行研究，但這項新發現可以降低胚胎幹細胞研究的需求。
問：新方法如何進行？
答：在皮膚細胞中插入四個基因。科學家知道，這些特定的基因可啟動或關閉其他基因，這些基因組合可將皮膚細胞轉變為類似幹細胞，但究竟如何達成仍是個謎。
問：這些細胞就是所謂的「成體幹細胞」？
答：不是。所謂成體幹細胞可在人體內發現，已具備轉變成各類細胞的能力，不需要再插入四個基因。
問：這種新方法是否有任何缺點？
答：初期階段使用這項技術會干擾皮膚細胞的DNA，可能引發癌症。以此方式製作幹細胞作為疾病治療的方法目前仍無法被接受。但DNA遭干擾只是這項技術的副產物，專家相信會有預防之道。
問：這對於一般人的意義何在？我們可以預期很快出現新的治療方法嗎？
答：幾年內還不行。除了克服癌症障礙，科學家還必須解決這些細胞的基本問題。在醫學方面，科學家可先利用這些細胞從事實驗室研究，例如篩檢可能的藥物。
http://money.chinatimes.com/q_news/961121000012.htm
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genome
- V1
- 文章: 1941
- 註冊時間: 週六 8月 11, 2007 4:26 am
疑 拍謝拍謝 上一post的四基因是陰謀論 因為沒有看全文 想當然耳
一開始我想到的是這一篇
http://www.nature.com/nbt/journal/v25/n ... t1335.html
裡面有提到四個基因 Oct4, Sox2, c-myc, Klf4 (c-myc是oncogene)
至於用來把基因送入fibroblast的 是retrovirus的簡化版 (如lentivirus或Moloney-based retrovirus)
(不要啊)
至於開欄這篇Nature paper裡 是用融合的方式 把(恆河猴的)fibroblast的細胞核融合進到活化的無核卵子 然後這個"卵子"就會開始長長長 變成blastocyst
疑 這一招 跟Rudolf Janeisch在2002年發展的nuclear cloning有啥不同??
(咦)
Janeisch已經做到從老鼠的lymphocyte細胞核做出stem cell 而且還由此複製出老鼠
http://www.nature.com/nature/journal/v4 ... re718.html
難道me-too一下 改用靈長類 就可以再丟一次Nature!?
如果說要採偶的細胞來做複製人大軍
相信從偶的任何一條intern line抽血 一定比做skin biopsy來得不痛
一開始我想到的是這一篇
http://www.nature.com/nbt/journal/v25/n ... t1335.html
裡面有提到四個基因 Oct4, Sox2, c-myc, Klf4 (c-myc是oncogene)
至於用來把基因送入fibroblast的 是retrovirus的簡化版 (如lentivirus或Moloney-based retrovirus)
(不要啊)
至於開欄這篇Nature paper裡 是用融合的方式 把(恆河猴的)fibroblast的細胞核融合進到活化的無核卵子 然後這個"卵子"就會開始長長長 變成blastocyst
疑 這一招 跟Rudolf Janeisch在2002年發展的nuclear cloning有啥不同??
(咦)
Janeisch已經做到從老鼠的lymphocyte細胞核做出stem cell 而且還由此複製出老鼠
http://www.nature.com/nature/journal/v4 ... re718.html
難道me-too一下 改用靈長類 就可以再丟一次Nature!?
如果說要採偶的細胞來做複製人大軍
相信從偶的任何一條intern line抽血 一定比做skin biopsy來得不痛