Origin and Fate of Myogenic Stem Cells

肌源干细胞的起源和命运

基本信息

批准号：
7015604
负责人：
MINDY GEORGE-WEINSTEIN
金额：
$ 19.18万
依托单位：
PHILADELPHIA COLLEGE OF OSTEOPATHIC MED
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-03-01 至 2008-02-28
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): Undifferentiated stem cells are present in the adult organism. In most cases it is unclear whether these cells are capable of differentiating along multiple pathways or programmed to develop along a single pathway. Furthermore, the origin of adult stem cells is unknown. The following studies focus on myogenic stem cells. The general hypotheses to be tested in these experiments are that stem cells committed to the skeletal muscle lineage: (1) are present in the epiblast of the early chick embryo, (2) become incorporated into organs lacking skeletal muscle during gastrulation, and (3) are able to induce multipotent stem cells to form muscle. These hypotheses were formulated as a result of previous studies in which small numbers of cells from the epiblast and a variety of fetal organs lacking skeletal muscle express the myogenic transcription factor MyoD in vivo and differentiate in vitro. Commitment to the skeletal muscle lineage will be tested by first analyzing whether transcription factors that regulate the development of other tissues are co-expressed with MyoD in epiblast cells. Second, MyoD positive epiblast cells will be isolated from the quail embryo using the G8 antibody, implanted into the developing heart fields and chondrogenic region of the limb bud, then analyzed for the expression of cardiac and cartilage specific molecules. To test whether the myogenic stem cells present in fetal organs originate from cells that express MyoD in the epiblast, the MyoD/G8 positive cells will be isolated from the quail epiblast, implanted into the chick epiblast, the embryos grown to fetal stages, and organs examined for the presence of quail cells. Organs from adult chickens and mice will be analyzed by RT-PCR and in situ hybridization for the expression of MyoD and Myf5. Finally, the ability of myogenic stem cells to induce multipotent stem cells to form muscle will be tested by co-culturing MyoD/G8 positive cells with chick epiblast cells and mouse embryonic stem cells. These experiments will begin to address the possibility that stably programmed cells could be used to enhance tissue regeneration in vivo when combined with multipotent stem cells.

描述（由申请人提供）：成人生物体中存在未分化的干细胞。在大多数情况下，尚不清楚这些细胞是否能够沿多个途径进行区分或编程以沿单个途径发展。此外，成年干细胞的起源尚不清楚。以下研究集中于肌源性干细胞。在这些实验中要测试的一般假设是，有助于骨骼肌谱系的干细胞存在：（1）存在于早期鸡胚胎的上生细胞中，（2）（2）被掺入胃部缺乏骨骼肌的器官中，并且（3）能够诱导多能干细胞形成肌肉。这些假设是由于先前的研究而提出的，在先前的研究中，少量细胞来自骨骼肌的细胞和各种缺乏骨骼肌的胎儿器官表达体内的肌源性转录因子myod并在体外区分。首先分析调节其他组织发育的转录因子是否与薄细胞细胞中的MYOD共表达，对骨骼肌谱系的承诺将进行测试。其次，将使用G8抗体从鹌鹑胚胎中分离Myod阳性epiblast细胞，该抗体植入了肢体芽的发育中的心脏场和软骨芽区域，然后分析了心脏和软骨特异性分子的表达。为了测试胎儿器官中存在的肌源性干细胞是否起源于表达肌细胞的细胞，将从鹌鹑层细胞中分离出MyOD/G8阳性细胞，并将其植入鸡皮细胞，生长到胎儿阶段的胚胎，并检查Quail细胞的器官。来自成年鸡和小鼠的器官将通过RT-PCR和原位杂交分析Myod和MyF5的表达。最后，通过将MyOD/G8阳性细胞与雏鸡的细胞和小鼠胚胎干细胞共同培养，将测试肌源性干细胞诱导多能干细胞形成肌肉的能力。这些实验将开始解决稳定编程的细胞可用于与多能干细胞结合使用时体内增强组织再生的可能性。