title: Modulation of satellite cells in rat facial muscle following denervation and delayed reinnervation.
abstract: CONCLUSIONS
  Long-term denervation-induced satellite cells (SCs) deficiency impairs facial muscle regenerative capacity. Delayed reinnervation can reactivate residual SCs to engage in muscle regeneration. However, the underlying mechanism remains to be elucidated.
  
  
  OBJECTIVE
  To evaluate the effects of denervation and delayed reinnervation on SCs in facial muscle.
  
  
  METHODS
  This was a prospective, randomized, controlled study in the rat facial nerve ligation and delayed decompression model. Animals were divided into denervation, 8-week-delay, and 16-week-delay reinnervation groups. Sham-operated animals served as a control group. Specific markers were used to investigate the differences in SC status, including quiescent (Pax7) and activated (myoD and myogenin) SCs and regenerative myofibers (embryonic myosin heavy chain, eMyHC). Quantitative assessment was performed by real-time PCR and Western blotting.
  
  
  RESULTS
  Activated SCs were detected 2-4 weeks after denervation and maintained for 4-8 weeks, accompanied by regenerating myofibers, whereas no SCs were detected beyond 20 weeks post-denervation. The myoD and myogenin up-regulation peaked 6-8 weeks after denervation and declined gradually to normal baseline 12 weeks after denervation. The 8-week-delay reinnervation group showed more activated SCs and regenerating myofibers than the 16-week-delay group, as well as greater up-regulation of myoD and myogenin (p < 0.05), suggesting reactivation of SCs for repair of adjacent fibers.
authors.affiliation: Department of Otorhinolaryngology-Head & Neck Surgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Donghui
authors.initials: D
authors.lastname: Chen
authors.forename: Shicai
authors.initials: S
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.forename: Chuansen
authors.initials: C
authors.lastname: Zhang
authors.forename: Hongliang
authors.initials: H
authors.lastname: Zheng
mesh_terms: D000818:Animals; D015153:Blotting, Western; D005152:Facial Muscles / Q000294:innervation* / Q000473:pathology; D005158:Facial Paralysis / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D008866:Microsurgery; D009000:Monocytes / Q000473:pathology; D009121:Muscle Denervation; D017570:MyoD Protein / Q000235:genetics; D018008:Myogenin / Q000235:genetics; D009416:Nerve Regeneration / Q000235:genetics / Q000502:physiology*; D051761:Paired Box Transcription Factors / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration / Q000235:genetics / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D032496:Satellite Cells, Skeletal Muscle / Q000473:pathology / Q000502:physiology*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D017570:MyoD Protein; C503803:Myog protein, rat; D018008:Myogenin; C530821:PAX7 protein, rat; D051761:Paired Box Transcription Factors