Myogenic Potential of Extraocular Muscle Satellite Cells

眼外肌卫星细胞的生肌潜力

• 批准号: 7586961
• 负责人: LINDA K. MCLOON
• 金额: $ 18.88万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-03-01 至 2011-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7586961
• 关键词: Adult; Age; Aging; Apoptosis; Apoptotic; Atrophic; Autologous; Biological Assay; Bromodeoxyuridine; CD34 gene; Cell Death; Cell division; Cells; Cellular biology; Coupled; Data; Denervation; Development; Disease; Duchenne muscular dystrophy; Environment; Eye; Genes; Genetic; Goals; Hematopoietic; Heterozygote; In Vitro; Injury; Label; Laboratories; Laryngeal muscle structure; Leg; Life; Limb structure; Modeling; Morphology; Mus; Muscle; Muscle Cells; Muscle Development; Muscle Fibers; Muscle satellite cell; Muscular Dystrophies; Myoblasts; Myopathy; Natural regeneration; Neonatal; Newborn Infant; PECAM1 gene; PTPRC gene; Patients; Population; Process; Proliferating; Property; Resistance; Rest; Skeletal Muscle; Somites; Source; Testing; Tissues; Transplantation; Utrophin; Work; base; cell type; in vivo; irradiation; mdx mouse; mouse model; nerve supply; novel strategies; orbit muscle; precursor cell; prevent; progenitor; public health relevance; regenerative; research study; satellite cell

DESCRIPTION (provided by applicant): The extraocular muscles (EOM) are spared in Duchenne muscular dystrophy patients (DMD) and continue to function after most skeletal muscles in the body have completely degenerated. The reason for this sparing in DMD is unknown. Unlike limb skeletal muscle, normal adult EOM retain a population of activated satellite cells, the regenerative cell in adult skeletal muscle. Satellite cells actively fuse into normal myofibers in the EOM throughout life, even in aging EOM, resulting in a continuous process of myofiber remodeling. The EOM and their satellite cells are extremely resilient to injury, denervation, disease, and aging, retaining normal morphology when limb muscle would normally atrophy. In addition, the early genes controlling EOM development are distinct from those that control somite development. We will test the hypothesis that this continuous remodeling is the process by which EOM are spared in DMD. We will examine 1) the rate of myogenic precursor cell turnover in two mouse models of DMD, the mdx and mdx/utrophin+/- (mdx/utrhet) mice, and 2) test whether inhibition of cell division in the EOM prevent their sparing in the two mouse models for DMD. The sparing of the EOM in DMD, aging, and injury and differences in the myogenic precursor cell populations in skeletal muscle suggest myogenic precursor cells (mpcs) within EOM may be significantly enriched or phenotypically distinct compared with adult limb muscle cells. There are 5-8 fold more myogenic precursor cells in adult EOM compared to limb. Additionally, mpcs from EOM are more resistant to apoptosis than similar cells from limb. We will test the hypothesis that continuous remodeling allows for EOM sparing in DMD by examining 1) the rate of myogenic precursor cell turnover in two mouse DMD models, the mdx and mdx/utrophin+/- heterozygote (mdx/utrhet) mice, and 2) whether inhibition of cell division by gamma irradiation of the EOM prevents sparing in the DMD models. Sparing of the EOM in DMD and differences in their mpcs suggest that the EOM mpcs may be significantly enriched or phenotypically distinct compared with adult limb mpcs. One population is increased; these cells are CD34+ and negative for Sca1, CD31, an endothelial lineage marker, CD45, an hematopoietic lineage marker, and negative for various satellite cell markers (EOMCD34). These EOMCD34 cells are present in the EOM and limb muscles of neonatal mice, but only maintained throughout adulthood in EOM. These cells are also present in the EOM of mdx and mdx/utrophin-/- mice. Our hypothesis is that this population of EOMCD34 cells enriched in adult EOM may be, at least in part, responsible for the sparing of EOM in DMD. We will test these hypotheses in two Specific Aims. Specific aim 1 asks: 1) is the rate of myofiber remodeling increased in the DMD mice models? 2) Does inhibition of cell division in adult EOM prevent sparing in the EOM of mdx/utrophin +/- heterozygote mice? We will isolate specific subpopulations of mononucleated cells from EOM and limb muscles and in specific aim 2 ask: 1) Are the mpcs more resistant to injury?2) Are the mpcs from EOM more multipotent than those from limb muscle? 3) Do the myogenic precursor cells from EOM have greater proliferative potential than those derived from limb skeletal muscle? The long term goal is to define and isolate a myogenic precursor cell type from EOM that has greater proliferative and survival potential compared with limb. These cells would be tested in a myoblast transfer model to determine their potential for use in the treatment of DMD. These may offer advantages over other cells, as autologous transplants would be possible. PUBLIC HEALTH RELEVANCE: The extraocular muscles (EOM) are spared in Duchenne muscular dystrophy (DMD), and the cause of this sparing is unknown. The unique ability of EOM to continuously remodel throughout life suggests that this ability may be responsible for this sparing. This may be due to an enriched myogenic precursor cell population within the EOM that has a greater ability to survive injury, aging and disease. While the eye muscles are spared in DMD, the rate of regeneration in the EOM is similar to that in the leg muscles of the mdx mouse model of DMD. We will attempt to demonstrate that muscle precursor cell division is responsible for sparing of the EOM by using irradiation to inhibit cell division. It is well known that the EOM survive injury better than limb muscle. This in turn suggests that muscle progenitors in EOM may be more robust and long-lived than those from limb muscles. If these hypotheses are true, ultimately we hope to exploit this by using identified myogenic precursor cells from EOM as a new source of donor cells in myoblast therapy in mice models of muscle injury and DMD.

描述（由申请人提供）：在Duchenne肌肉营养不良患者（DMD）中幸免了眼外肌肉（EOM），并在体内大多数骨骼肌完全退化后继续起作用。 DMD中这种保留的原因尚不清楚。与肢体骨骼肌不同，正常的成年EOM保留了成年骨骼肌中的活化卫星细胞的种群。卫星细胞即使在衰老的EOM中，也会在EOM中积极融合正常的肌纤维，从而导致肌纤维重塑的连续过程。 EOM及其卫星细胞对损伤，神经，疾病和衰老极为韧性，在肢体肌肉通常会萎缩时保持正常的形态。此外，控制EOM发育的早期基因与控制节点发育的基因不同。我们将检验以下假设：这种连续的重塑是在DMD中保留EOM的过程。我们将检查1）DMD的两种小鼠模型，MDX和MDX/Utrophin +/-（MDX/UTRHET）小鼠的肌原性前体细胞更新速率，以及2）测试EOM中EOM中细胞分裂的抑制是否阻止了它们在两种小鼠模型中的差异。 DMD，衰老和损伤中EOM的保留以及骨骼肌肌肌肉细胞群体的差异表明，EOM中EOM中的肌源性前体细胞（MPC）可能显着富集或表型与成年肢肌细胞相比。与肢体相比，成人EOM中有5-8倍的肌原性前体细胞。另外，来自EOM的MPC比肢体的类似细胞更耐凋亡。 We will test the hypothesis that continuous remodeling allows for EOM sparing in DMD by examining 1) the rate of myogenic precursor cell turnover in two mouse DMD models, the mdx and mdx/utrophin+/- heterozygote (mdx/utrhet) mice, and 2) whether inhibition of cell division by gamma irradiation of the EOM prevents sparing in the DMD models.与成人肢体MPC相比，DMD中EOM的保留和MPC的差异表明，EOM MPC可能显着富集或表型差异。一个人口增加；这些细胞为CD34+，对于SCA1，CD31，内皮谱系标记，CD45，造血谱系标记物以及各种卫星细胞标记物为阴性（EOMCD34）。这些EOMCD34细胞存在于新生小鼠的EOM和肢体肌肉中，但仅在EOM中保持整个成年。这些细胞也存在于MDX和MDX/Utrophin - / - 小鼠的EOM中。我们的假设是，富含成人EOM的EOMCD34细胞的种群至少部分原因是DMD中的EOM保留。我们将以两个具体目标来检验这些假设。特定目标1问：1）DMD小鼠模型中肌化纤维重塑的速率是否有所增加？ 2）成人EOM中细胞分裂的抑制是否可以防止MDX/Utrophin +/-杂合子小鼠的EOM保留？我们将从EOM和肢体肌肉中分离出单核细胞的特定亚群，并且在特定的目标2问：1）MPC是否对损伤更具耐药性？2）EOM中的MPC是否比肢体肌肉的MPC更多动力？ 3）来自EOM的肌源性前体细胞是否比肢体骨骼肌衍生出的肌源性具有更大的增殖潜力？长期目标是与肢体相比，从EOM定义和分离出具有更大增殖和生存电位的肌源性前体细胞类型。这些细胞将在成肌细胞转移模型中进行测试，以确定其在DMD治疗中使用的潜力。这些可能比其他细胞具有优势，因为自体移植是可能的。 公共卫生相关性：外部肌肉（EOM）在Duchenne肌肉营养不良（DMD）中保留下来，这种保留的原因尚不清楚。 EOM在一生中连续重塑的独特能力表明，这种能力可能是造成这种不足的原因。这可能是由于EOM内富集的肌源性前体细胞群，具有更大的损伤，衰老和疾病的能力。尽管眼睛肌肉在DMD中幸免，但EOM的再生速率与DMD MDX小鼠模型的腿部肌肉相似。我们将尝试证明肌肉前体细胞分裂是通过使用辐照抑制细胞分裂的肌肉造成EOM的损害。众所周知，EOM比肢体肌肉更好地生存。这反过来表明，EOM中的肌肉祖细胞可能比肢体肌肉的肌肉更健壮和长寿。如果这些假设是真实的，最终我们希望通过使用EOM确定的肌源性前体细胞作为肌肉损伤和DMD模型中成肌细胞疗法的新来源来利用这种假设。