"Reversibility of Differentiating Myogenic Cells to Muscle Stem Cells"

“肌原细胞分化为肌肉干细胞的可逆性”

• 批准号: 8521677
• 负责人: CHEN-MING FAN
• 金额: $ 20.69万
• 依托单位: CARNEGIE INSTITUTION OF WASHINGTON, D.C.
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8521677
• 关键词: Acute; Adult; Age; Aging-Related Process; Alleles; Animal Housing; Animal Model; Biological; Cells; Characteristics; Chimeric Proteins; Chronic; DNA; Data; Development; Direct Lytic Factors; Disease; Embryo; Estrogen Receptors; Event; Exercise; Funding; Gene Silencing; Genes; Genetic; Homeostasis; Injury; Investigation; Knock-in Mouse; Label; Mechanics; Methodology; Minor; Modeling; Mouse Strains; Movement; Mus; Muscle; Muscle Development; Muscle satellite cell; Myogenin; Myosin Light Chains; Natural regeneration; Nature; PTPRC gene; Pericytes; Perinatal; Posture; Process; Regulation; Reporter; Research; Research Personnel; Series; Skeletal Muscle; Source; Specificity; Staging; Tamoxifen; Testing; Time; Wasting Syndrome; Work; cell behavior; cell type; gene function; in vivo; injured; insight; muscle aging; muscle regeneration; muscular system; myogenesis; neonate; overexpression; progenitor; public health relevance; recombinase; stem cell population; tibialis anterior muscle; tool

DESCRIPTION (provided by applicant): The mouse provides an invaluable mammalian model for skeletal muscle research, partly due to continuous development of sophisticated genetic tools. The tamoxifen (tmx) inducible forms of Cre DNA recombinase (Cre) - estrogen receptor (ER) fusion protein is a powerful tool for inducible gene manipulation. A complete set of myogenic Cre-ERT2 (CE) alleles should facilitate the progress of the field. We have initiated making a series of myogenic CE KI alleles at the Pax3, Myf5, MyoD, Mrf4, Myogenin (Mgn), and Myosin light chain 1f (Mlc1f) loci (Aim 1). Together with Pax7, their expression represents a sequence of events, from muscle progenitor to terminally differentiated state, during development and regeneration. These new alleles will not only be useful for our research, but also beneficial to researchers in the field at large. There have been data implicating cell sources that do not express Pax7 (Pax7- cells) but act as muscle stem cells (e.g. CD45+Sca1+ cells, PICs, or pericytes). We hypothesize that these proclaimed Pax7- muscle stem cells are in fact myogenic cells that loses Pax7 expression in transit to differentiation but can regain Pax7 expression and return to the muscle stem cell state (Aim 2). Aim 1: Generating and characterizing a myogenic series of CE alleles. This series is under various stages of development. They will be used to perform tmx-inducible cell marking. Short-term cell marking will be performed to characterize the specificity of cell marking and the cell potential to contribute to muscles and other cell types. Aim 2: Testing the possibility that differentiating myogenic cells can revert to the muscle stem cell state. Two scenarios will be tested: 1) developmental progression and 2) regeneration. We will determine whether certain CE lines that do not label Pax7+ cells in short-term labeling, but give rise to Pax7+ cells after long term tracing, in either experimental paradigm. While the "reverted" stem cell population hypothesized may only represent a minor fraction, they likely have the potential to replenish the Pax7+ cells over time in chronic muscle wasting diseases and during the aging process.

描述（由申请人提供）：小鼠为骨骼肌肉研究提供了宝贵的哺乳动物模型，部分原因是复杂的遗传工具的不断发展。他莫昔芬（TMX）可诱导的Cre DNA重组酶（CRE） - 雌激素受体（ER）融合蛋白是诱导基因操纵的强大工具。一组完整的肌原性CRE-ERT2（CE）等位基因应促进该领域的进展。我们已经在PAX3，MyF5，Myod，MRF4，Myogenin（MGN）和肌球蛋白轻链1F（MLC1F）基因座（AIM 1）制作了一系列肌原性CE KI等位基因。与PAX7一起，它们的表达代表了一系列事件，从肌肉祖细胞到最终分化状态，在发育和再生过程中。这些新等位基因不仅对我们的研究有用，而且对整个领域的研究人员有益。 有数据暗示了不表达PAX7（PAX7-细胞）而是肌肉干细胞（例如CD45+ SCA1+细胞，图片或周细胞）的细胞源。我们假设这些被称为PAX7-肌肉干细胞实际上是肌源性细胞，在转移中失去PAX7表达为分化，但可以恢复PAX7的表达并恢复到肌肉干细胞状态（AIM 2）。 AIM 1：产生和表征一系列肌源性CE等位基因。该系列处于发展的各个阶段。它们将用于执行TMX诱导的细胞标记。将进行短期细胞标记，以表征细胞标记的特异性以及有助于肌肉和其他细胞类型的细胞电位。目标2：测试区分肌原性细胞可以恢复为肌肉干细胞状态的可能性。将测试两种情况：1）发展进展和2）再生。我们将确定在短期标记中不标记PAX7+细胞的某些CE线是否在长期追踪后引起PAX7+细胞，在任何一个实验范式中都会引起PAX7+细胞。尽管假设的“恢复”干细胞种群可能仅代表次要的部分，但它们可能有可能在慢性肌肉浪费疾病和衰老过程中随着时间的流逝补充PAX7+细胞。