title: Myocardin-A enhances expression of promyogenic genes without depressing telomerase activity in adipose tissue-derived mesenchymal stem cells.
abstract: BACKGROUND
  The stromal compartment of adult adipose tissue consists of mesenchymal stem cells (MSCs) characterized by co-expression of myocardin-A (McA) and telomerase reverse transcriptase (TERT).
  
  
  OBJECTIVE
  This study aims at testing the growth and myogenic regenerative properties of adipose tissue-derived MSCs, and the outcome of McA and TERT overexpression or suppression.
  
  
  RESULTS
  TERT and/or McA in murine MSCs derived from adult adipose tissue were transduced with cDNA and co-immunoprecipitated with specific antibodies. The MSCs with TERT or TERT plus McA overexpressed were highly proliferative. Bioluminescence resonance energy transfer assay evidenced close interactions between TERT and McA in MSCs co-transfected with TERT and McA, which expressed the stem cell oncogene Oct-4, and promyogenic genes GATA-4, Nkx2.5, MLC2v, Mef2c, DTEF and McA. The increased myogenic gene expression depended on TERT and McA expression as siRNAs for TERT and McA diminished the TERT activities. The co-transfected MSCs also developed a stronger activity of serum response factor, a key factor for expression of cardiomyogenic genes. McA overexpression did not interfere with TERT-mediated proliferative effects, and rather slightly increased proliferation of MSCs.
  
  
  CONCLUSIONS
  McA and TERT may interplay in promoting promyogenic gene expression and maintaining growth capacity of MSCs.
authors.affiliation: Texas Heart Institute, Houston, TX, United States.
authors.forename: Rosalinda
authors.initials: R
authors.lastname: Madonna
authors.forename: Danli
authors.initials: D
authors.lastname: Wu
authors.forename: Michael
authors.initials: M
authors.lastname: Wassler
authors.forename: Raffaele
authors.initials: R
authors.lastname: De Caterina
authors.forename: James T
authors.initials: JT
authors.lastname: Willerson
authors.forename: Yong-Jian
authors.initials: YJ
authors.lastname: Geng
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D053595:Embryonic Stem Cells / Q000378:metabolism; D004789:Enzyme Activation / Q000502:physiology; D005786:Gene Expression Regulation; D008297:Male; D059630:Mesenchymal Stem Cells / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D019098:Telomerase / Q000096:biosynthesis* / Q000235:genetics*; D015534:Trans-Activators / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: C511173:Mrtfa protein, mouse; D015534:Trans-Activators; D019098:Telomerase; C509187:Tert protein, mouse