文章来源:未知 文章作者:meng 发布时间:2010-06-27 07:02 字体: [ ]  进入论坛

A mechanism1 that regulates(调节,校准) stem-cell differentiation2(细胞分化) in mice testes(睾丸) suggests a similar process that may trigger degenerative disease(变性疾病) in humans, according to a Penn State College of Agricultural Sciences reproductive physiologist3. Research involved manipulating a protein called STAT3 that signals stem cells to decide whether to differentiate4 into a specialized5 type of cell or self-renew and remain stem cells. By manipulating STAT3, researchers identified a key regulator of spermatogonial stem cell self-renewal.

The STAT3 protein, which is active in tissues throughout the body and is essential for life, regulates genes7 that are involved in cell growth and division, cell movement, and the self-destruction of cells. All tissue and organs within the body are based on a specific differentiated8 cell type, and these cells are constantly lost through cell death and aging. For the testis, the differentiated cell type is sperm6(精子) .

Every time a stem cell divides, it produces two new cells. Self-renewal is the process by which this division results in a stem cell duplicating itself, thus maintaining a stem cell pool. Differentiation is when the stem cell division produces cells that will become the differentiated(分化的) cells that maintain the function of the tissue or organ. Impairment(损伤,损害) of either of these stem-cell functions manifests as tissue and organ failure, so deciphering(破译,解释) the mechanisms9 that regulate stem-cell activity is of utmost(极度的,最远的) importance for devising treatments for degenerative diseases.

"We looked at a mechanism that is involved in the differentiation of stem cells, and we were actually able to shift that decision away from differentiation into self-renewal," said Jon Oatley, assistant professor of reproductive physiology10, who led the study. "Right now we are at the ground level -- we discovered this in a mouse, and we hope we can start to look at it in human disease to see whether this pathway still holds true. We hope that down the line, as we study it further, we may be able to tie it to human disease."

Several key regulators of spermatogonial stem cell self-renewal have been identified, but knowledge of molecules11 that control spermatogonial stem cell differentiation is lacking, Oatley explained.

"In this study, we found that impairment of STAT3 signaling enhances spermatogonial stem cell self-renewal without affecting general proliferation(增殖,扩散) of the cells. That indicates an alteration12 in the balance of spermatogonial stem cell fate decisions that inhibited13 differentiation in favor of self-renewal."

Much stem-cell research is done of necessity with mice, noted14 Oatley, who pointed15 out that scientists who use the mouse as a model for human biology make the assumption that what they learn about in a mouse is identical to what happens in a human.

"Ideally, any of us who work with mice would love to translate our work into humans, but the problem is that you can't get the tissue samples from humans, and you can't manipulate the genetics of humans to show what we want to learn," he said.

Oatley said he believes his research is a solid first step in helping16 scientists learn how to regulate STAT2 levels to treat or control degenerative disease in humans.


1 mechanism zCWxr     
  • The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
  • The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。
2 differentiation wuozfs     
  • There can be no differentiation without contrast. 有比较才有差别。
  • The operation that is the inverse of differentiation is called integration. 与微分相反的运算叫做积分。
3 physiologist 5NUx2     
  • Russian physiologist who observed conditioned salivary responses in dogs (1849-1936). (1849-1936)苏联生理学家,在狗身上观察到唾液条件反射,曾获1904年诺贝尔生理学-医学奖。
  • The physiologist recently studied indicated that evening exercises beneficially. 生理学家新近研究表明,傍晚锻炼最为有益。
4 differentiate cm3yc     
  • You can differentiate between the houses by the shape of their chimneys.你可以凭借烟囱形状的不同来区分这两幢房子。
  • He never learned to differentiate between good and evil.他从未学会分辨善恶。
5 specialized Chuzwe     
  • There are many specialized agencies in the United Nations.联合国有许多专门机构。
  • These tools are very specialized.这些是专用工具。
6 sperm jFOzO     
  • Only one sperm fertilises an egg.只有一个精子使卵子受精。
  • In human reproduction,one female egg is usually fertilized by one sperm.在人体生殖过程中,一个精子使一个卵子受精。
7 genes 01914f8eac35d7e14afa065217edd8c0     
n.基因( gene的名词复数 )
  • You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因,所以能够活得很长。 来自《简明英汉词典》
  • Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
8 differentiated 83b7560ad714d20d3b302f7ddc7af15a     
区分,区别,辨别( differentiate的过去式和过去分词 ); 区别对待; 表明…间的差别,构成…间差别的特征
  • The development of mouse kidney tubules requires two kinds of differentiated cells. 小鼠肾小管的发育需要有两种分化的细胞。
  • In this enlargement, barley, alfalfa, and sugar beets can be differentiated. 在这张放大的照片上,大麦,苜蓿和甜菜都能被区分开。
9 mechanisms d0db71d70348ef1c49f05f59097917b8     
n.机械( mechanism的名词复数 );机械装置;[生物学] 机制;机械作用
  • The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
  • He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》
10 physiology uAfyL     
  • He bought a book about physiology.他买了一本生理学方面的书。
  • He was awarded the Nobel Prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。
11 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
12 alteration rxPzO     
  • The shirt needs alteration.这件衬衣需要改一改。
  • He easily perceived there was an alteration in my countenance.他立刻看出我的脸色和往常有些不同。
13 inhibited Fqvz0I     
  • Boys are often more inhibited than girls about discussing their problems. 男孩子往往不如女孩子敢于谈论自己的问题。
  • Having been laughed at for his lameness,the boy became shy and inhibited. 那男孩因跛脚被人讥笑,变得羞怯而压抑。
14 noted 5n4zXc     
  • The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
  • Jim is noted for arriving late for work.吉姆上班迟到出了名。
15 pointed Il8zB4     
  • He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
  • She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。
16 helping 2rGzDc     
  • The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
  • By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。
TAG标签: cells disease protein