title: Proteomic Analysis and Identification of Paracrine Factors in Mesenchymal Stem Cell-Conditioned Media under Hypoxia.
abstract: OBJECTIVE
  We previously showed that a hypoxic environment modulates the antiarrhythmic potential of mesenchymal stem cells.
  
  
  METHODS
  To investigate the mechanism by which secreted proteins contribute to the pathogenesis of antiarrhythmic potential in mesenchymal stem cells, we used two-dimensional electrophoresis combined with MALDI-TOF-MS to perform a proteomic analysis to compare the paracrine media produced by normoxic and hypoxic cells.
  
  
  RESULTS
  The proteomic analysis revealed that 66 protein spots out of a total of 231 matched spots indicated differential expression between the normoxic and hypoxic conditioned media of mesenchymal stem cells. Interestingly, two tropomyosin isoforms were dramatically increased in the hypoxic conditioned medium of mesenchymal stem cells. An increase in tropomyosin was confirmed using Western blot to analyze the conditioned media between normoxic and hypoxic cells. In a network analysis based on gene ontology (GO) Molecular Function by GeneMANIA analysis, most of the identified proteins were found to be involved in the regulation of heart processes.
  
  
  CONCLUSIONS
  Our results show that hypoxia up-regulates tropomyosin and other secreted proteins which suggests that tropomyosin may be involved in regulating proarrhythmic and antiarrhythmic functions.
authors.affiliation: Department of Cardiovascular Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Suk-Won
authors.initials: SW
authors.lastname: Song
authors.forename: Kyung-Eun
authors.initials: KE
authors.lastname: Kim
authors.forename: Jung-Won
authors.initials: JW
authors.lastname: Choi
authors.forename: Chang Youn
authors.initials: CY
authors.lastname: Lee
authors.forename: Jiyun
authors.initials: J
authors.lastname: Lee
authors.forename: Hyang-Hee
authors.initials: HH
authors.lastname: Seo
authors.forename: Kyu Hee
authors.initials: KH
authors.lastname: Lim
authors.forename: Soyeon
authors.initials: S
authors.lastname: Lim
authors.forename: Seahyong
authors.initials: S
authors.lastname: Lee
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Ki-Chul
authors.initials: KC
authors.lastname: Hwang
mesh_terms: D000818:Animals; D015687:Cell Hypoxia; D017077:Culture Media, Conditioned / Q000494:pharmacology*; D015180:Electrophoresis, Gel, Two-Dimensional; D053263:Gene Regulatory Networks; D059630:Mesenchymal Stem Cells / Q000187:drug effects / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism; D019899:Paracrine Communication / Q000187:drug effects*; D020033:Protein Isoforms / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D051381:Rats; D016622:Silver Staining; D014335:Tropomyosin / Q000378:metabolism
chemical_list: D017077:Culture Media, Conditioned; D020033:Protein Isoforms; D014335:Tropomyosin