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【bio-news】孕期由母亲传给孩子的细胞继续存活且
01/22/07 -- It has been known for some years that mother and baby exchange stem cells in the course of pregnancy, and that these may live on for many years, apparently tolerated by the new host. The phenomenon is known as microchimerism, and it is still unclear as to whether the presence of such cells can be harmful to the recipient. A Bristol team has looked for maternal cells in children with type 1 diabetes, an immune-mediated disorder, and found that around 20 per cent of these children have unusually high levels of maternal DNA in their circulation. An even more surprising finding is that some maternal cells have entered the child's pancreas and are functioning there as insulin-producing beta cells. The study, initially undertaken in the belief that maternal cells might trigger autoimmunity in the child, has now taken an interesting new twist, for the maternal cells might even be helping the child to repair injury.
In this study, published in the January 22 issue of the Proceedings of the National Academy of Sciences, Dr Kathleen Gillespie and Professor Edwin Gale from the Department of Clinicl Science @ North Bristol in collaboration with Professor J. Lee Nelson and colleagues at Fred Hutchinson Cancer Research Center, Seattle, found no evidence that the mother's cells were attacking the child's insulin cells and no evidence that the maternal cells were targets of an immune response from the child's immune system.
Instead, the researchers found a small number of female islet beta cells in male pancreatic tissue (procured from autopsies) that produced insulin. Microchimerism is the term used when an individual harbors cells or DNA that originate from another genetically distinct individual. "To our knowledge a maternal contribution to endocrine function has not previously been described," the authors said. "Our findings also raise the possibility that naturally acquired microchimerism might be exploited to therapeutic benefit."
The study also found significantly higher levels of maternal DNA in the peripheral blood of 94 children and adults with Type 1 diabetes as compared to 54 unaffected siblings and 24 unrelated healthy subjects they studied.
Originally, the study of 172 individuals and pancreatic tissue from four males was designed to ask the question whether small numbers of maternal cells might be involved in any way in Type 1 diabetes. "Our initial theory was that perhaps, in some situations, too many cells cross from mother to fetus in pregnancy. Could diabetes result because the child lost tolerance to those cells because they are genetically half foreign? Our research appears to disprove this," said Professor Gale. "It is possible that the maternal cells may even be helping to regenerate damaged tissue in the pancreas."
The investigators are excited about the observation that maternal microchimerism results in cells that make insulin - these maternal stem cells could provide new insights into how insulin producing beta cells are generated.
Source: University of Bristol
http://www.bio.com/newsfeatures/newsfeatures_research.jhtml;jsessionid=MTMCOPN3JOOB1R3FQLMSFEWHUWBNQIV0?cid=25300011 本人认领此文. 如在48小时内未能提供译文, 其他战友可自由认领 初译：
Cells Passed from Mother to Child During Pregnancy Live On and Make Insulin
孕期由母亲传给孩子的细胞继续存活且可造胰岛素
01/22/07 -- It has been known for some years that mother and baby exchange stem cells in the course of pregnancy, and that these may live on for many years, apparently tolerated by the new host. The phenomenon is known as microchimerism, and it is still unclear as to whether the presence of such cells can be harmful to the recipient. A Bristol team has looked for maternal cells in children with type 1 diabetes, an immune-mediated disorder, and found that around 20 per cent of these children have unusually high levels of maternal DNA in their circulation. An even more surprising finding is that some maternal cells have entered the child's pancreas and are functioning there as insulin-producing beta cells. The study, initially undertaken in the belief that maternal cells might trigger autoimmunity in the child, has now taken an interesting new twist, for the maternal cells might even be helping the child to repair injury.
01/22/07 -- 多年前人们就已经知道，在怀孕过程中，母亲会与胎儿互相交换干细胞，并且交换后的干细胞可在新宿主的体内继续存活多年。这一现象被称为微嵌合状态， 但目前尚不清楚这些干细胞的存在是否会对新宿主产生不利影响。 来自英国港市布里斯托尔的一支研究团队通过对Ⅰ型糖尿病（一种免疫介导性疾病）儿童进行研究，结果发现约20％的儿童在其循环系统中有异常高的母体DNA水平。 更为令人惊奇的是，有些母细胞进入其胰腺组织中，发展为制造胰岛素的β-细胞。这项研究的初衷是寻找母细胞激发儿童自身免疫性的证据，但现在因为发现母细胞可能有助于糖尿病儿童的自我修复，所以研究的方向起了戏剧性的转变。
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作者:admin@医学,生命科学 2011-09-02 17:13
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