title: AAV2-mediated follistatin overexpression induces ovine primary myoblasts proliferation.
abstract: BACKGROUND
  Follistatin (FST) has been shown to bind to some TGF-β family members and can function as a potent myostatin (MSTN) antagonist. Recent studies have revealed that over-expression of FST by adeno-associated viruses increases muscle growth in mice, humans and nonhuman primates. In the present study, to determine the effect of FST on ovine primary myoblast (OPM) proliferation, FST was over-expressed using an adeno-associated virus serotype 2 (AAV 2) vector.
  
  
  RESULTS
  Western blot results showed that AAV induced the expression of FST protein in transduced OPM cells. Real-time quantitative PCR results indicated that over-expression of FST resulted in a dramatic increase in Akt I and CDK2 expression and a decrease in p21 expression. Moreover, cell cycle analysis confirmed that FST down-regulated p21, a CDK inhibitor, and increased the level of CDK2 expression in OPM cells. Hence, follistatin positively regulated the G1 to S progression. Our results showed that FST induced proliferation through a down-regulation of p21, as only the p21 expression level was down-regulated as a result of FST over-expression in myoblasts, whereas no change was observed in the level of p57 expression.
  
  
  CONCLUSIONS
  These results expanded our understanding of the regulation mechanism of FST in ovine primary myoblasts. Our results provide the first evidence that the AAV viral system can be used for gene transfer in ovine myoblast cells. Moreover, the results showed that an AAV vector can successfully induce the expression of FST in OPM cells in vitro. These findings demonstrated that FST over-expression induces proliferation through a down-regulation of the p21 gene under proliferating conditions.
authors.affiliation: National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China. Fat_sa_2005@yahoo.com.
authors.forename: Mahmood
authors.initials: M
authors.lastname: Nazari
authors.affiliation: Transgenic and Stem Cell Core, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China. Fat_sa_2012@yahoo.com.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Salabi
authors.affiliation: National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China. zhangli@263.net.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China. zfpcau@gmail.com.
authors.forename: Fuping
authors.initials: F
authors.lastname: Zhao
authors.affiliation: National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China. weicaihong@caas.cn.
authors.forename: Caihong
authors.initials: C
authors.lastname: Wei
authors.affiliation: National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100193, People's Republic of China. lxdu@263.net.
authors.forename: Lixin
authors.initials: L
authors.lastname: Du
mesh_terms: D000818:Animals; D002453:Cell Cycle; D049109:Cell Proliferation; D051357:Cyclin-Dependent Kinase 2 / Q000235:genetics / Q000378:metabolism; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D000229:Dependovirus / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation; D038681:Follistatin / Q000235:genetics* / Q000378:metabolism*; D005822:Genetic Vectors / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D032446:Myoblasts / Q000166:cytology* / Q000378:metabolism; D012756:Sheep / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21; D038681:Follistatin; D051357:Cyclin-Dependent Kinase 2