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リエゾンラボ研究会
発表内容

Title:
Induction of Paraxial Mesodermal Progenitors from Pluripotent Stem Cell in Chemically Defined Differentiation Condition. To Aim Cell Therapy for Muscular Dystrophy.

Hidetoshi Sakurai, M.D., Ph.D.
Department of Clinical Applications, Center for iPS Cell Research and Application (CiRA), Kyoto University Lecturer

Abstract:
Stem cell transplantation is considered as one of possible therapies for Duchenne Muscular Dystrophy (DMD), the most common congenital muscle disease. Skeletal muscles and muscle satellite cells are derived from paraxial mesodermal cells. We showed previously that embryonic stem (ES) cell-derived PDGFR- α (+) cells represent paraxial mesodermal progenitors and differentiate into muscle satellite cells in vivo . Moreover, treatment of mouse ES cells cultured in a serum-free condition with Bon e Morphogenetic Protein 4 (BMP4), and then, with Lithium Chloride (LiCl) promoted the generation of paraxial mesodermal cells and their differentiation to myogenic progenitors. On the basis of these findings, we have developed an efficient method to generate and purify PDGFR- α (+) paraxial mesodermal progenitors driven by several growth factors in a serum-free conditions from mouse induced pluripotent stem (iPS) cells, a beneficial cellular resource for stem cell therapies with its capacity of differentiation to all three germ layers as ES cell. We have demonstrated that this differentiation procedure well replicates embryonic mesodermal development. These iPS-derived PDGFR- α (+) cells included myogenic cells in vitro. When they were directly transplanted into muscles of DMD model (Dystrophin-deficient) mice, those cells were incorporated into regenerating muscle fibers. The transplanted cells were fused with host myofibers and expressed Dystrophin, leading to an inhibition of muscular inflammation. Engrafted cells also differentiated into muscle satellite cells in vivo . Taken together, these results reveal two important findings. First, we have successfully generated myogenic mesodermal progenitors in a serum- free condition from mouse iPS cells. Second, transplantation of these iPS cell-derived myogenic mesodermal progenitors can ameliorate structure of skeletal muscle in DMD model mice through expression of Dystrophin in regenerating muscle and production of iPS-derived satellite cells. These findings encourage us to establish an efficient cell therapy for the DMD mediated by iPS cell-derived mesodermal progenitors.

References:
(1) Sakurai H., Era T., Lakt LM., Okada M., Nakai S., Nishikawa S., Nishikawa SI.
In vitro modeling of paraxial and lateral mesoderm differentiation reveals early reversibility . Stem Cells. 2006 Mar;24(3): 575-86

(2) Sakurai H., Okawa Y., Inami Y., Nishio N., Isobe K.
Paraxial mesodermal progenitors derived from mouse embryonic stem cells contribute to muscle regeneration via differentiation into muscle satellite cells . Stem Cells. 2008 Jul;26(7): 1865-73

(3) Sakurai H., Inami Y., Tamamura Y., Yoshikai T., Sehara-Fujisawa A., Isobe K.
Bidirectional induction toward paraxial mesodermal derivatives from mouse ES cells in chemically defined medium. Stem Cell Research. 2009 Sep-Nov;3(2-3):157-69.