细微RNA分子可能是预防早产的关键因素
文章来源:未知 文章作者:meng 发布时间:2010-11-16 02:18 字体: [ ]  进入论坛
(单词翻译:双击或拖选)

Tiny molecules1 called microRNAs act together with hormones3 to control the onset4 of labor5, raising the prospect6 that RNA-based drugs might be able to prevent premature7 labor, researchers at UT Southwestern Medical Center have discovered in a preclinical study. "With these findings, we understand better the system that controls labor, so with future research we might have the potential to manipulate it and prevent preterm birth," said Dr. Carole Mendelson, professor of biochemistry and obstetrics(产科学) and gynecology(妇科学) at UT Southwestern and senior author of the study, which appears in an online issue of the Proceedings8 of the National Academy of Sciences.

Using pregnant mice as well as human uterine(子宫的) tissue, the researchers uncovered a feedback cycle involving microRNAs, proteins called ZEB1 and ZEB2, and the pregnancy9-maintaining hormone2 progesterone, as well as genes10 and other factors that control contraction11 of the uterus.

"We've been struggling for a long time to understand how progesterone(黄体酮) keeps the uterus from contracting during most of pregnancy," Dr. Mendelson said. "Our findings indicate that progesterone controls a family of microRNAs whose levels dramatically increase right before labor. At the same time, levels of the microRNAs' targets, the ZEB proteins, decrease. This enables uterine contractions12."

MicroRNA is one form of RNA, a chemical cousin of DNA13. MicroRNAs interact with other protein-making molecules in cells, helping14 to fine-tune the expression of networks of genes and control cell function, Dr. Mendelson said.

In the new study, the researchers measured microRNA levels in the uteri of mice in mid-pregnancy and near labor. As labor approached, the level of a group of microRNAs called the miR-200 family greatly increased. When the researchers artificially stimulated15 premature labor, the miR-200 levels also increased.

The miR-200s block the production of two proteins called ZEB1 and ZEB2. In contrast, progesterone directly increases ZEB1 levels. The researchers uncovered a feedback cycle involving all these factors that prevents uterine contraction as long as progesterone is present.

"We found that during pregnancy, progesterone acts on the feedback loop to keep the microRNA levels down and the ZEBs up," said Nora Renthal, Medical Scientist Training Program student and lead author of the study. "The ZEBs, in turn, inhibit16 contraction-associate genes. But then, just prior to labor, there's a switch. Progesterone action decreases; the ZEBs are suppressed; the miR-200s increase; and the contraction-associated genes are turned on."

The researchers directly tested the contractility(收缩性) of cultured human uterine cells containing low or high levels of ZEB1 or ZEB2. In the presence of oxytocin(催产术) , uterine cells with low levels of ZEBs contracted, while those with high levels did not, mirroring what happened in the pregnant mice.

While the study shows that the miR-200 family might be a likely therapeutic17 target to fight premature labor, the microRNAs and their interaction with the ZEB proteins also are known to play a role in cancer, so drug development would have to be approached very carefully, Dr. Mendelson said.



点击收听单词发音收听单词发音  

1 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
参考例句:
  • 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。
2 hormone uyky3     
n.荷尔蒙,激素,内分泌
参考例句:
  • Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
  • This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
3 hormones hormones     
n. 荷尔蒙,激素 名词hormone的复数形式
参考例句:
  • This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
  • The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。
4 onset bICxF     
n.进攻,袭击,开始,突然开始
参考例句:
  • The drug must be taken from the onset of the infection.这种药必须在感染的最初期就开始服用。
  • Our troops withstood the onset of the enemy.我们的部队抵挡住了敌人的进攻。
5 labor P9Tzs     
n.劳动,努力,工作,劳工;分娩;vi.劳动,努力,苦干;vt.详细分析;麻烦
参考例句:
  • We are never late in satisfying him for his labor.我们从不延误付给他劳动报酬。
  • He was completely spent after two weeks of hard labor.艰苦劳动两周后,他已经疲惫不堪了。
6 prospect P01zn     
n.前景,前途;景色,视野
参考例句:
  • This state of things holds out a cheerful prospect.事态呈现出可喜的前景。
  • The prospect became more evident.前景变得更加明朗了。
7 premature FPfxV     
adj.比预期时间早的;不成熟的,仓促的
参考例句:
  • It is yet premature to predict the possible outcome of the dialogue.预言这次对话可能有什么结果为时尚早。
  • The premature baby is doing well.那个早产的婴儿很健康。
8 proceedings Wk2zvX     
n.进程,过程,议程;诉讼(程序);公报
参考例句:
  • He was released on bail pending committal proceedings. 他交保获释正在候审。
  • to initiate legal proceedings against sb 对某人提起诉讼
9 pregnancy lPwxP     
n.怀孕,怀孕期
参考例句:
  • Early pregnancy is often accompanied by nausea.怀孕早期常有恶心的现象。
  • Smoking during pregnancy increases the risk of miscarriage.怀孕期吸烟会增加流产的危险。
10 genes 01914f8eac35d7e14afa065217edd8c0     
n.基因( gene的名词复数 )
参考例句:
  • 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
11 contraction sn6yO     
n.缩略词,缩写式,害病
参考例句:
  • The contraction of this muscle raises the lower arm.肌肉的收缩使前臂抬起。
  • The forces of expansion are balanced by forces of contraction.扩张力和收缩力相互平衡。
12 contractions 322669f84f436ca5d7fcc2d36731876a     
n.收缩( contraction的名词复数 );缩减;缩略词;(分娩时)子宫收缩
参考例句:
  • Contractions are much more common in speech than in writing. 缩略词在口语里比在书写中常见得多。 来自《简明英汉词典》
  • Muscle contractions are powered by the chemical adenosine triphosphate(ATP ). 肌肉收缩是由化学物质三磷酸腺苷(ATP)提供动力的。 来自辞典例句
13 DNA 4u3z1l     
(缩)deoxyribonucleic acid 脱氧核糖核酸
参考例句:
  • DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
  • Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。
14 helping 2rGzDc     
n.食物的一份&adj.帮助人的,辅助的
参考例句:
  • 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。
15 stimulated Rhrz78     
a.刺激的
参考例句:
  • The exhibition has stimulated interest in her work. 展览增进了人们对她作品的兴趣。
  • The award has stimulated her into working still harder. 奖金促使她更加努力地工作。
16 inhibit C7jxT     
vt.阻止,妨碍,抑制
参考例句:
  • Don't let ego and greed inhibit clear thinking and hard work.不要让自我和贪婪妨碍清晰的思维和刻苦的工作。
  • They passed a law to inhibit people from parking in the street.他们通过一项法令以阻止人们在街上停车。
17 therapeutic sI8zL     
adj.治疗的,起治疗作用的;对身心健康有益的
参考例句:
  • Therapeutic measures were selected to fit the patient.选择治疗措施以适应病人的需要。
  • When I was sad,music had a therapeutic effect.我悲伤的时候,音乐有治疗效力。
TAG标签: online labor RNA
发表评论
请自觉遵守互联网相关的政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
验证码:点击我更换图片