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本帖最后由 laputave 于 2011-4-20 00:46 编辑
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Scientists Develop 'Universal' Virus-Free Method to Turn Blood Cells Into 'Beating' Heart Cells
4 @$ a5 ^$ q/ ?/ o科学家们开发出将血细胞转化为跳动的心肌细胞的无病毒的通用方法 D) \/ s n& N k: S
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注明：
" ?; d3 C: y9 \% m来源：http://www.sciencedaily.com/releases/2011/04/110408210728.htm4 x- B: {" m. K3 l1 b
由干细胞之家论坛新闻小组成员laputave翻译，转帖请注明. ^/ |; g% N9 n0 d8 _ A+ H- o' [
个人理解，翻译不妥之处还望各位前辈批评指正。
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' ~7 g$ X) p7 Z' D6 @. A- t6 Y翻译正文
. R+ `7 u/ b* L- n( w==============稍稍便动了一下格式，希望大家看的习惯================! @2 ]& b) ^/ @% a) S" X
ScienceDaily (Apr. 11, 2011) — Johns Hopkins scientists have developed a simplified, cheaper, all-purpose method they say can be used by scientists around the globe to more safely turn blood cells into heart cells. The method is virus-free and produces heart cells that beat with nearly 100 percent efficiency, they claim.$ c7 K! {6 C% W E) O) |0 ^
约翰.霍普金斯研究所的科学家们已经开发出一种简化、廉价、通用的转化方法，他们称该法可以被全世界的科学家用来更为安全的将血细胞转化为心肌细胞。并且，这种无病毒的方法诱导产生的心肌细胞几乎100%跳动。
1 q, l0 j4 B2 t$ v5 C1 c5 ~0 C原本此处有图片的。。但十分不清晰。。
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"We took the recipe for this process from a complex minestrone to a simple miso soup," says Elias Zambidis, M.D., Ph.D., assistant professor of oncology and pediatrics at the Johns Hopkins Institute for Cell Engineering and the Kimmel Cancer Center.7 r8 Q: S4 F5 }4 m
伊莱亚斯.扎姆比迪斯笑谈道：“在这个过程中我们将这个配方从一个复杂的蔬菜通心粉汤简化为简单的味增汤。”伊莱亚斯.扎姆比迪斯（医学和哲学博士）是约翰霍普金斯研究院细胞工程和基梅尔癌症中心肿瘤学和儿科学的助理教授。/ J5 ]% |+ L7 b
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Zambidis says, "many scientists previously thought that a nonviral method of inducing blood cells to turn into highly functioning cardiac cells was not within reach, but "we've found a way to do it very efficiently and we want other scientists to test the method in their own labs." However, he cautions that the cells are not yet ready for human testing.8 W' B1 C/ J$ ]; m" g; d
扎姆比迪斯说，“许多科学家之前认为诱导血细胞转化为强大功能的心肌细胞的非病毒方法并非是触手可及的，但是我们找到了一种高效的诱导方法，并希望其他科学家在他们自己的实验室检验这种方法。”然而，他警告道，这种诱导细胞尚未准备在人体内进行实验。
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2 o u5 T* T& f# {/ ]0 oTo get stem cells taken from one source (such as blood) and develop them into a cell of another type (such as heart), scientists generally use viruses to deliver a package of genes into cells to, first, get them to turn into stem cells. However, viruses can mutate genes and initiate cancers in newly transformed cells. To insert the genes without using a virus, Zambidis' team turned to plasmids, rings of DNA that replicate briefly inside cells and eventually degrade.
$ p1 c8 s4 f G为了得到体细胞来源（例如血液来源）的干细胞并将这些细胞转化为其他类型的细胞（例如心肌细胞），科学家们通常用病毒作为传递包装外源基因的载体，将外源基因转入体细胞中并将它们转化为干细胞。然而，在新转化的细胞中病毒的存在会使细胞基因产生突变并引发癌症。为了不用借助病毒便可以向细胞中插入基因，扎姆比迪斯的团队求助于质粒，质粒是一种可以在宿主细胞内进行短暂的自我复制并最终退化掉的环状DNA分子。
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J5 H# {' a# ZAdding to the complexity of coaxing stem cells into other cell types is the expensive and varied recipe of growth factors, nutrients and conditions that bathe stem cells during their transformation. The recipe of this "broth" differs from lab to lab and cell line to cell line.! x# O: C7 V' {* J+ \ m$ o# n
添加的将干细胞诱导成其他细胞的复合物是一个昂贵且种类繁多的生长因子、营养及细胞转化过程所需的各种条件的复杂配方。这个液体培养基的配方在不同实验室及不同细胞系之间各不相同。
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Reporting in the April 8 issue of Public Library of Science ONE (PLoS ONE), Zambidis' team described what he called a "painstaking, two-year process" to simplify the recipe and environmental conditions that house cells undergoing transformation into heart cells. They found that their recipe worked consistently for at least 11 different stem cell lines tested and worked equally well for the more controversial embryonic stem cells, as well as stem cell lines generated from adult blood stem cells, their main focus.3 R" d$ c" K m- Z* G
在4月8号发表在《公共科学图书馆•综合》杂志的报道中，扎姆比迪斯的团队将简化储存经历转化的细胞的培养液配方和培养条件的过程称为“艰辛两年”。他们发现他们的配方一致的适用于所测试的11种干细胞系，并且，这个配方同样也适用于更有争议的胚胎干细胞（ESC）。ESC和来自于成年血液的干细胞一样，都是该研究组的、所关注的问题。' ~( O5 U$ M8 G8 Z8 t
4 \2 X) u" K: m9 N+ j0 R( O; nThe process began with Johns Hopkins postdoctoral scientist Paul Burridge, Ph.D., who studied some 30 papers on techniques to create cardiac cells. He drew charts of 48 different variables used to create heart cells, including buffers, enzymes, growth factors, timing, and the size of compartments in cell culture plates. After testing hundreds of combinations of these variables, Burridge narrowed the choices down to between four to nine essential ingredients at each of three stages of cardiac development.
C4 Z0 t4 S- s5 a/ C7 b这项研究以约翰.霍普金斯研究院的保罗.布里奇博士的工作为开端。布里奇博士研究了大约30篇关于诱导产生心肌细胞方法的论文，随后他列出了一份用于诱导心肌细胞的48中不同变量的表格，其中包括缓冲体系、酶、生长因子、时间以及细胞培养板培养孔的大小等因素。在测试了这些变量的几百种组合之后，布里奇博士将选择范围缩小为4至9种因素，这些因素在心肌细胞发育的三个阶段都是至关重要的。! u7 H( K5 n" ?
# q6 d6 Z3 S6 _8 C# Q$ {Beyond simplification, an added benefit is reduced cost. Burridge used a cheaper growth media that is one-tenth the price of standard media for these cells at $250 per bottle lasting about one week.
, J/ z- f- d+ D- r, o# S4 C除了简化配方之外，这项工作的另一个好处就是降低了细胞培养的成本。布里奇博士使用的是更为廉价的培养液，这个培养液的价格是这些细胞250美元每瓶试用一周的标准培养液价格的十分之一。9 A& k& {( N0 ^5 X) _
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Zambidis says that he wants other scientists to test the method on their stem cell lines, but also notes that the growth "soup" is still a work in progress. "We have recently optimized the conditions for complete removal of the fetal bovine serum from one brief step of the procedure -- it's made from an animal product and could introduce unwanted viruses," he says.
1 I" S' L; D# T, y# q- E扎姆比迪斯希望科学家们可以用他们自己研究的干细胞来检验这个配方，此外他也注明，这种培养液配方仍然有待改进。他说：“为了完全去除培养液中的胎牛血清成分，我们对这一程序中教案段的一步做了优化。胎牛血清这种动物制品会向整个培养体系中引入不希望的病毒。”8 _; V6 ^3 \+ @ ?* h5 P9 @! p
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In their experiments with the new growth medium, the Hopkins team began with cord blood stem cells and a plasmid to transfer seven genes into the stem cells. They delivered an electric pulse to the cells, making tiny holes in the surface through which plasmids can slip inside. Once inside, the plasmids trigger the cells to revert to a more primitive cell state that can be coaxed into various cell types. At this stage, the cells are called induced pluripotent stem cells (iPSC).3 Z- V$ j% Q- n
在用新的培养液配方进行的实验中，霍普金斯课题组先以脐带血干细胞和可以向干细胞中转化7个基因的质粒为材料进行研究。他们对细胞施加电压，在细胞表面击穿出一个可以供质粒穿过的细小的孔道。一旦携带外源基因的质粒进入到细胞内，这些质粒就可以触发细胞转化为可以被诱导为多种细胞类型的更为原始的细胞状态。这种状态的细胞被称为诱导多功能干细胞（IPSC）。6 m4 Z3 Z2 }7 Y' W1 K7 ~" c3 {4 l
1 F+ m! h3 g+ J) @/ d0 d* BBurridge then bathed the newly formed iPSCs in the now simplified recipe of growth media, which they named "universal cardiac differentiation system." The growth media recipe is specific to creating cardiac cells from any iPSC line.
8 C. O$ V1 V# h' s* o然后，布里奇简化的生长培养液培养新形成的iPSC细胞，他们将这种简化的培养液称为“通用型心肌细胞分化体系”。这种生长培养液是用于从任何iPSC特定分化形成心肌细胞。9 ~* Q0 l& v: ^: C
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Finally, they incubated the cells in containers that removed oxygen down to a quarter of ordinary atmospheric levels. "The idea is to recreate conditions experienced by an embryo when these primitive cells are developing into different cell types," says Burridge. They also added a chemical called PVA, which works like glue to make cells stick together.
! E2 Y( ~( B: n( l- Y V( y/ @$ J9 b最终，他们在氧气含量为大气含量的1/4的培养箱中孵育细胞。布里奇说到：“再造转化环境的想法来自于从观察胚胎从原始的细胞形态转化为不同的细胞类型的整个过程得到的经验。”他们也向培养液中添加了PVA（聚醋酸乙烯酯Polyvinyl Acetate），其作用是像胶一样增加培养液粘度，使细胞相互粘附。5 m& n) A8 w6 N2 e5 ^. e' Y7 _
; ^" n/ u3 ]) f! ~, s- dNine days later, the nonviral iPSCs turned into functional, beating cardiac cells, each the size of a needlepoint.
* z0 Q4 J( Q, F3 n! h九天后，非病毒转化的iPSCs分化为机能的，跳动的心肌细胞，每一个细胞如针尖般大小。9 P# i& N( P9 V" _) e! p; C
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Burridge manually counted how often iPSCs formed into cardiac cells in petri dishes by peering into a microscope and identifying each beating cluster of cells. In each of 11 cell lines tested, each plate of cells had an average of 94.5 percent beating heart cells. "Most scientists get 10 percent efficiency for IPSC lines if they're lucky," says Zambidis.
* g _$ E( C8 B. P( [通过在显微镜下观察和辨认每一个跳动的心肌细胞簇，布里奇亲手数出了iPSCs转化为心肌细胞的几率。在测试的11种细胞系中，每一培养板平均拥有94.5%的转化率。扎姆比迪斯说：“幸运的话，大多数科学家用iPSC做实验时能得到10%的转化率。4 V; q2 c1 U a
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Zambidis and Burridge also worked with Johns Hopkins University bioengineering experts to apply a miniversion of an electrocardiograph to the cells, which tests how cardiac cells use calcium and transmit a voltage. The resulting rhythm showed characteristic pulses seen in a normal human heart.
0 I! [4 p* {5 m: n$ i5 v扎姆比迪斯和比力奇与约翰.霍普金斯大学的生物工程专家们共同研制出一种用于测试这些细胞如何利用Ca离子和传导点位的迷你心电图仪。测试的结果表明，这些细胞有着和正常人心脏相同的特征跳动频率。* p7 F& w/ j$ F) ?( W, S9 X
( w9 z5 ~3 ]7 n' e% Z: fVirus-free, iPSC-derived cardiac cells could be used in laboratories to test drugs that treat arrhythmia and other conditions. Eventually, bioengineers could develop grafts of the cells that are implanted into patients who suffered heart attacks.
4 p2 T4 V. B1 p! f. P2 C. y8 H这种无病毒的iPSC来源地心肌细胞可以用于治疗心律不齐或其他心脏疾病的药物测试。最终，生物工程专家们或可研发出植入患有心脏病患者体内的细胞移植疗法。
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- q: g% G+ e( W zZambidis' team has recently developed similar techniques for turning these blood-derived iPSC lines into retinal, neural and vascular cells.' O2 z2 b: q/ j6 o2 ]9 j
The research was funded by the Maryland Stem Cell Research Fund and the National Institutes of Health.
8 n" M- b+ e/ g& `) O4 yResearch participants include Susan Thompson, Michal Millrod, Seth Weinberg, Xuan Yuan, Ann Peters, Vasiliki Mahairaki, Vassilis E. Koliatsos, and Leslie Tung at Johns Hopkins.
0 G* Q4 e# d& I6 J, y N扎姆比迪斯的团队最近用类似的方法成功的将血细胞来源的iPSC分化为视网膜，神经和血管细胞。8 R7 h' D" S: P5 X0 S! C7 ^
这项研究由马里兰干细胞研究基金会和美国国立健康研究院资助。! w( A( ^8 r$ V, b
共同研究者有Susan Thompson, Michal Millrod, Seth Weinberg, Xuan Yuan, Ann Peters, Vasiliki Mahairaki, Vassilis E. Koliatsos, and Leslie Tung .: V+ Y7 v+ N% A% g( n3 P7 Q
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发表于 2011-4-20 00:44
发表于 2011-4-20 10:01
