幹細胞論壇

（新加坡18日訊）新加坡科學家發現了人類幹細胞“百變”的秘密，而且只要啟動這個被稱為PRDM14的基因，任何普通細胞都有可能“變身”為幹細胞，成功率比現有技術高三倍。
 
擁有多能性（pluripotency）的胚胎幹細胞（embryonic stem cell），能變成人體裡200多種細胞中的任何一種，自我“繁殖”能力也強，因此一直被視為各種絕症的希望。




星洲日報／國際‧2010.10.18
 

Scientists First to Perform Genome-Wide Study of Human Stem Cells

Their research, published in the journal Nature, is the first ever genome-wide study of human stem cells on such a massive scale, and its results are crucial in understanding how stem cells may one day be used to treat debilitating conditions such as Parkinson's disease and traumatic spinal injury.

GIS Senior Group Leader for Stem Cell and Development Biology and Associate Director for Biology Dr Ng Huck Hui, and IMCB Principal Investigator Dr Frederic Bard combined the strengths of their teams to investigate the 21,000 genes in the entire human genome to find those which regulate the two characteristic properties of hESCs -- the capacity to turn into any type of cell in the human body (pluripotency), and the ability to retain that capacity indefinitely. Out of the several key genes they identified, a particular gene known as PRDM14 was discovered to make it easier to turn a type of human cell (fibroblasts) into pluripotent stem cells. The discoveries contribute to a fundamental understanding of the nature of stem cells and helps efforts to improve techniques to turn mature adult cells into hESCs.

In addition, the scientists found that PRDM14 played a key role in hESCs, but not in mouse ESCs. This significant new finding highlights the fundamental differences between stem cells from different species, and highlights the greater need to use human cells in stem cell research.

"Very little is known about the molecular machines that drive stem cell states or the transcriptional profiles of hESCs. Our study helps to build a better understanding of hESCs and this will help in the development of technologies to further the utilities of these cells such as their potential to be used for clinical and therapeutic applications," said Dr Ng. "Dr Bard's scientific expertise was invaluable in helping us crack another piece of the stem cell puzzle. I definitely look forward to collaborating with him on more projects that aim to peel away the mysteries surrounding stem cells" he added.

Dr Alan Colman, Executive Director of the Singapore Stem Cell Consortium, said, "Huck Hui Ng and his colleagues continue to keep Singapore at the top table of countries plundering the secrets of human embryonic stem cell regulation. This time they have deployed the first genome-wide functional screen to identify factors that maintain 'stemness' in these cells and yet again reveal major differences between mouse and human embryonic stem cells in the control of this important property."

Senior Scientist at the Developmental & Stem Cell Biology Program, The Hospital for Sick Children, Dr Janet Rossant added, "The unprecedented scale of this screen has added considerable new information to our understanding of pluripotency and will help efforts to improve reprogramming of adult cells."

Professor Lee Eng Hin, Executive Director of the Biomedical Research Council, A*STAR, applauded the discovery and said, "This is an examplar of a great cross institutional collaboration. The combined strength of stem cell and genomics experts has led to a great piece of world-class work. I hope to see more of such valuable partnerships in the future."

John Conley將在星期三(10/18)成為美國Emory大學第七位利用幹細胞移植的漸凍人(Amyotrophic Lateral Sclerosis:ALS)臨床試驗者.
Conley在2009/09被診斷出[肌萎縮性側索硬化症],俗稱漸凍人(ALS),當時非常震驚與恐懼.在歷經數個月後,Conley願意接受Emory大學醫學中心的幹細胞臨床試驗治療,希望就此可結束13個月癱瘓的生涯.
Emory大學醫學中心的移植醫師Dr. Jonathan Glass將胚胎幹細胞在體外培養成神經細胞,再移植到病患的脊髓當中,最終的目標希望可以延長與減緩病患神經癱瘓的發生.
這項手術內容請看http://www.myfoxatlanta.com/dpp/news/health-watch-stem-cell-trial-101810

瑞典卡羅林斯卡醫學院研究人員８日報告說，他們研究發現一類名為室管膜細胞(ependymal cell)的幹細胞不僅可幫助生成更多新的脊髓細胞，還能幫助恢復脊髓功能。這一成果將有助於研究人員尋找治療人類各種脊髓損傷的新療法。
研究人員在新一期美國《細胞－幹細胞》雜誌上介紹說，他們對實驗鼠的研究發現，一旦老鼠的骨髓組織受損，存在於骨髓中的室管膜細胞就會被啟動，和一些其他類型的細胞一起，促使分化形成更多的新的骨髓細胞，成為生成新骨髓細胞的“主要來源”。
而在未受損傷的老鼠脊髓組織中，室管膜細胞通常是不活躍的，新的骨髓細胞的形成主要由那些與幹細胞相比處於更加成熟階段的細胞分裂而成。
不過，研究人員介紹說，脊髓嚴重受損後，其功能恢復的關鍵可能在於限制尾隨損傷之後的疤痕組織形成，而不僅僅是加強脊髓細胞的再生能力。
但室管膜細胞的身份這時卻顯得有些“尷尬”，雖然它促進分化形成更多新的脊髓細胞，但與此同時，它也會分化形成疤痕組織細胞，另外還分化形成一類對於脊髓功能十分重要的支持細胞。
因此研究人員猜測，也許能夠篩選出一種藥物，在脊髓受損後，能夠有選擇地刺激室管膜細胞，使它分化形成更多的支持細胞，少分化疤痕組織細胞，從而更好地幫助受損脊髓恢復功能。
Stem Cells Repair Damaged Spinal Cord Tissue
 

ScienceDaily (Oct. 9, 2010) — Researchers at Karolinska Institutet have shown how stem cells, together with other cells, repair damaged tissue in the mouse spinal cord. The results are of potential significance to the development of therapies for spinal cord injury.

There is hope that damage to the spinal cord and brain will one day be treatable using stem cells (i.e. immature cells that can develop into different cell types). Stem cell-like cells have been found in most parts of the adult human nervous system, although it is still unclear how much they contribute to the formation of new, functioning cells in adult individuals.

A joint study by Professor Jonas Frisén's research group at Karolinska Institutet and their colleagues from France and Japan, and published in Cell Stem Cell, shows how stem cells and several other cell types contribute to the formation of new spinal cord cells in mice and how this changes dramatically after trauma.

The research group has identified a type of stem cell, called an ependymal cell, in the spinal cord. They show that these cells are inactive in the healthy spinal cord, and that the cell formation that takes place does so mainly through the division of more mature cells. When the spinal cord is injured, however, these stem cells are activated to become the dominant source of new cells.

The stem cells then give rise to cells that form scar tissue and to a type of support cell that is an important component of spinal cord functionality. The scientists also show that a certain family of mature cells known as astrocytes produce large numbers of scar-forming cells after injury.

"The stem cells have a certain positive effect following injury, but not enough for spinal cord functionality to be restored," says Jonas Frisén. "One interesting question now is whether pharmaceutical compounds can be identified to stimulate the cells to form more support cells in order to improve functional recovery after a spinal trauma."

喝紅酒可以預防心血管疾病？台北榮總心臟病科團隊研究發現，喝適量的紅酒可以降低心血管疾病的發生，原因出於增加了能夠修復血管損傷的幹細胞，多位醫師指出，一天一杯250c.c.紅酒，確可防動脈硬化，不過醫師也呼籲，飲酒過量仍會對肝、腎造成負擔。






 


 

【台灣醒報╱記者蕭如君╱台北報導】2010.10.12 08:35 am

 蘭嶼豬實驗 減少細胞壞死 生成新心血管

〔記者孟慶慈／台南報導〕罹患心肌梗塞（冠狀動脈阻塞），容易因血液無法正常供應以致心肌細胞壞死、心臟衰竭而死亡。成大醫學院助理教授謝清河及其團隊，以「心臟幹細胞療法」完成全球首例以大動物（豬）為對象的實驗，證明該療法可減少心肌細胞壞死，幹細胞更形成新的心血管，讓心臟幹細胞療法跨出一大步。

   更新日期:2010/10/12 01:19  

胚胎幹細胞研究今天邁入里程碑，因為這項創新又具爭議性的研究，已走出實驗室、來到臨床實驗。

研究人員希望能利用幹細胞，來填補因疾病、意外、戰爭或一般磨耗而受損的組織。鼓吹這項研究的人士表示，研究針對的目標包括阿茲海默症（Alzheimer's）、糖尿病等多種疾病。

胚胎幹細胞（embryonic stem cell）因具「全能性」，是目前為止用途最廣的幹細胞。「全能性」即是有能力分化成任何細胞種類。

它們來自受精卵，且研究人員通常讓它們長個3到5天再進行收成，然後放在自我複製的「行列」來進行研究。

然而，此法遭到宗教保守人士的大力抨擊。他們主張，人的生命從受孕那一刻就開始，因此破壞胚胎等同謀殺。

史上首次的胚胎幹細胞臨床研究，將由美國生物技術業者杰龍公司（Geron Corp）負責。參與這項研究的病患，正在喬治亞州亞特蘭大的醫院接受脊髓和腦損傷復健。杰龍表示，第一階段將評估安全性和容忍性。

幹細胞另一來源為成體幹細胞（adult stem cell）。儘管還未成熟，成體幹細胞通常被編列來分化成特定細胞種類。通常來說，成體幹細胞得到的媒體關注，遠低於胚胎幹細胞。

然而，近年來，研究人員發現成體幹細胞用途較原先以為的還要廣，且存於更廣泛的組織之中，包括大腦、骨髓、週邊血、血管、骨骼肌、皮膚和肝臟。

一份2007年的研究指出，皮膚取得的幹細胞「重新編列」之後，他們已發現一個創造多能幹細胞的方法。且在2008年1月，先進細胞科技公司（ACT）的藍札（Robert Lanza）所率領的團隊，宣布他們已成功找出一個不破壞胚胎，就能創造人類胚胎幹細胞的方法，為史上首次。

 
   

（日本‧東京6日訊）日本研究人員表示，他們已通過向年老大鼠移植年輕大鼠的骨髓，使年老大鼠全身血管機能“返老還童”。這一成果有望用於人類治療腦梗塞等疾病。
 
新華社報導，日本國立循環器官疾病研究中心等機構組成的聯合研究小組從出生4周的年輕大鼠體內採集骨髓，移植給50周齡的大鼠。30天後，年老大鼠血液中即有約5%的細胞來自年輕大鼠的骨髓，移植60天後，年老大鼠的死亡率降到自然狀態下的一半以下。
  

 
 
Stem cells used to reattach teeth in rats   

 更新日期:2010/10/05 04:11

〔編譯魏國金、記者湯佳玲／綜合報導〕試管嬰兒之父、英國生理學家羅伯特．艾德華斯，四日以發展試管受精技術，致使全球數百萬不孕症夫婦得享天倫之樂的貢獻，而獲頒二○一○年諾貝爾醫學獎。

四百萬嬰兒 因他降臨 

瑞典卡洛林斯卡研究院讚揚八十五歲的艾德華斯的試管受精（ＩＶＦ）技術，「是現代醫學發展的里程碑」。一九七八年第一位試管嬰兒露薏絲．布朗在英國誕生以來，迄今已有四百萬名嬰兒拜ＩＶＦ治療之賜而出生。如今一對不孕症伴侶在接受ＩＶＦ療程後，歡喜得子的機率是五比一，與健康伴侶自然受孕的機率相同。 

艾德華斯於一九五○年代開始研究ＩＶＦ，一九六八年他與婦產科醫師史戴普托共同發展出讓卵細胞體外受精的方法，一九七二年他們開始從事將胚胎放回母親子宮的技術，但因不當的荷爾蒙治療，許多孕婦被迫墮胎。一九七七年他們嘗試使用精準時間而不用荷爾蒙治療的新程序，翌年七月二十五日，第一名試管嬰兒布朗誕生。

艾德華斯說︰「露薏絲的出生意義深遠，我們必須對抗許多反對人士，但我們認定我們的理念可行，而且它們奏效！」布朗與艾德華斯一直保持聯絡，二○○七年以自然受孕的方式產下一子的布朗曾說︰「艾德華斯就像是我的祖父。」 

台北榮總婦產部生殖內分泌科主任張昇平表示，雖是遲來的肯定，但艾德華斯的得獎是「實至名歸」。 

張昇平表示，第一個試管嬰兒誕生，代表胚胎體外培育成為可能，並帶動了生殖醫學、分子醫學、內分泌醫學和胚胎幹細胞培養的進一步發展。 

張昇平也指出，第一個試管嬰兒的技術還有很多限制，如胚胎必須在第二天就植入母體。現今的胚胎可以在第五天再植入母體，醫師則可以在第三天檢查著床前的染色體，並透過胚胎幹細胞的技術，植入正常基因，避免遺傳性疾病。 

台大醫院婦產部主治醫師陳信孚認為，艾德華斯得獎有三個啟示，首先是「基本功夫要扎實」，因此他才能從中確認「信念」，相信體外受精培育胚胎、做成試管嬰兒是可行的，加上「堅持」，才能在試了八十多次後，最終成功。 

張昇平和陳信孚都與艾德華斯有數面之緣。張昇平覺得艾德華斯文質彬彬，很客氣，陳信孚說艾德華斯人很和藹，講話清晰有條理。 

有十一名孫兒的艾德華斯因身體孱弱，無法受訪。他獲贈一千萬瑞典克朗（台幣四千六百萬餘元）的獎金。