title: Transplantation of mesenchymal cells rejuvenated by the overexpression of telomerase and myocardin promotes revascularization and tissue repair in a murine model of hindlimb ischemia.
abstract: BACKGROUND
  The number and function of stem cells decline with aging, reducing the ability of stem cells to contribute to endogenous repair processes. The repair capacity of stem cells in older individuals may be improved by genetically reprogramming the stem cells to exhibit delayed senescence and enhanced regenerative properties.
  
  
  OBJECTIVE
  We examined whether the overexpression of myocardin (MYOCD) and telomerase reverse transcriptase (TERT) enhanced the survival, growth, and myogenic differentiation of mesenchymal stromal cells (MSCs) isolated from adipose or bone marrow tissues of aged mice. We also examined the therapeutic efficacy of transplanted MSCs overexpressing MYOCD and TERT in a murine model of hindlimb ischemia.
  
  
  RESULTS
  MSCs from adipose or bone marrow tissues of young (1 month old) and aged (12 months old) male C57BL/6 and apolipoprotein E-null mice were transiently transduced with lentiviral vectors encoding TERT, MYOCD, or both TERT and MYOCD. Flow cytometry and bromodeoxyuridine cell proliferation assays showed that transduction with TERT and, to a lesser extent, MYOCD, increased MSC viability and proliferation. In colony-forming assays, MSCs overexpressing TERT and MYOCD were more clonogenic than mock-transduced MSCs. Fas-induced apoptosis was inhibited in MSCs overexpressing MYOCD or TERT. When compared with aged mock-transduced MSCs, aged MSCs overexpressing TERT, MYOCD, or both TERT and MYOCD increased myogenic marker expression, blood flow, and arteriogenesis when transplanted into the ischemic hindlimbs of apolipoprotein E-null mice.
  
  
  CONCLUSIONS
  The delivery of the TERT and MYOCD genes into MSCs may have therapeutic applications for restoring, or rejuvenating, aged MSCs from adipose and bone marrow tissues.
authors.affiliation: From Heart Failure Research.
authors.forename: Rosalinda
authors.initials: R
authors.lastname: Madonna
authors.forename: Doris A
authors.initials: DA
authors.lastname: Taylor
authors.forename: Yong-Jian
authors.initials: YJ
authors.lastname: Geng
authors.forename: Raffaele
authors.initials: R
authors.lastname: De Caterina
authors.forename: Harnath
authors.initials: H
authors.lastname: Shelat
authors.forename: Emerson C
authors.initials: EC
authors.lastname: Perin
authors.forename: James T
authors.initials: JT
authors.lastname: Willerson
mesh_terms: D000273:Adipose Tissue / Q000166:cytology; D000818:Animals; D002454:Cell Differentiation; D006614:Hindlimb / Q000098:blood supply*; D007511:Ischemia / Q000628:therapy*; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018919:Neovascularization, Physiologic; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D000099251:Myocardin
chemical_list: D009687:Nuclear Proteins; D019098:Telomerase; D015534:Trans-Activators; D000099251:Myocardin; C509187:Tert protein, mouse
keywords: adipose–derived mesenchymal stem cells; aging; bone marrow stem cells; hindlimb ischemia; mesenchymal stem cells; myocardin; telomerase