title: The development of satellite cells and their niche in striated muscle complex of anorectal malformations rat embryos.
abstract: BACKGROUND
  It has been demonstrated that different degrees of pelvic floor muscle (PFM) maldevelop in anorectal malformations (ARMs); yet the development of satellite cells, the myogenic stem cells responsible for muscle growth, repair, and maintenance remains elusive during the embryogenesis of PFM. Striated muscle complex (SMC) is one of the most important components of PFM. The objective of this study was to observe the development pattern of satellite cells and their niche of SMC and investigate its possible role in PFM dysplasia in ARMs.
  
  
  METHODS
  Immunohistochemistry, cell culture, transmission electron microscopy (TEM), real-time quantitative PCR, and Western blot were performed to trace the dynamic development pattern of satellite cells during the morphogenesis of PFM in ethylenethiourea (ETU)-induced ARMs rat embryos.
  
  
  RESULTS
  In ARMs rat embryos, earlier presentation and higher number of Pax7-expressing cell were observed in SMC. The expression of Pax7 and vimentin were up-regulated, while the expression of myogenin, vWF, and neurofilament were down-regulated. Ultrastructure analysis of SMC was characterized by increased amount of nuclear heterochromatin of satellite cell nuclei, thickened basal lamina, widened gap between satellite cell and myofiber, and disarrangement of muscle fibers. The satellite cells demonstrated abnormal differentiation after they were isolated and cultured in vitro.
  
  
  CONCLUSIONS
  Our results suggest that premature origination of satellite cell from myogenic progenitor or precursor may result in the depletion of myogenic precursor and cessation of muscle growth; intrinsic defect in satellite cell structure, and extrinsic impairment of microenvironment compromised the myogenic competence of satellite cell, which might contribute substantially to the hypoplastic SMC in ARMs.
authors: Department of Pediatric Surgery, Shengjing Hospital, China Medical University, Shenyang, P.R. China.
authors: Qing Jiang
authors: QJ
authors: Chen
authors: Hui Min
authors: HM
authors: Jia
authors: Zhi Xin
authors: ZX
authors: Niu
authors: Tao
authors: T
authors: Zhang
authors: Yu Zuo
authors: YZ
authors: Bai
authors: Zheng Wei
authors: ZW
authors: Yuan
authors: Wei Lin
authors: WL
authors: Wang
mesh_terms: D000818:Animals; D000071056:Anorectal Malformations; D001006:Anus, Imperforate / Q000139:chemically induced / Q000196:embryology / Q000473:pathology; D002478:Cells, Cultured; D005031:Ethylenethiourea / Q000009:adverse effects; D005260:Female; D023421:Models, Animal; D009024:Morphogenesis / Q000502:physiology; D054792:Muscle, Striated / Q000196:embryology* / Q000378:metabolism / Q000473:pathology*; D018008:Myogenin / Q000378:metabolism; D051761:Paired Box Transcription Factors / Q000378:metabolism; D017773:Pelvic Floor / Q000196:embryology / Q000473:pathology; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D032496:Satellite Cells, Skeletal Muscle / Q000473:pathology*; D014746:Vimentin / Q000378:metabolism; D014841:von Willebrand Factor / Q000378:metabolism
chemical_list: D018008:Myogenin; C530821:PAX7 protein, rat; D051761:Paired Box Transcription Factors; D014746:Vimentin; D014841:von Willebrand Factor; D005031:Ethylenethiourea