title: Human thymus mesenchymal stromal cells augment force production in self-organized cardiac tissue.
abstract: BACKGROUND
  Mesenchymal stromal cells have been recently isolated from thymus gland tissue discarded after surgical procedures. The role of this novel cell type in heart regeneration has yet to be defined. The purpose of this study was to evaluate the therapeutic potential of human thymus-derived mesenchymal stromal cells using self-organized cardiac tissue as an in vitro platform for quantitative assessment.
  
  
  METHODS
  Mesenchymal stromal cells were isolated from discarded thymus tissue from neonates undergoing heart surgery and were incubated in differentiation media to demonstrate multipotency. Neonatal rat cardiomyocytes self-organized into cardiac tissue fibers in a custom culture dish either alone or in combination with varying numbers of mesenchymal stromal cells. A transducer measured force generated by spontaneously contracting self-organized cardiac tissue fibers. Work and power outputs were calculated from force tracings. Immunofluorescence was performed to determine the fate of the thymus-derived mesenchymal stromal cells.
  
  
  RESULTS
  Mesenchymal stromal cells were successfully isolated from discarded thymus tissue. After incubation in differentiation media, mesenchymal stromal cells attained the expected phenotypes. Although mesenchymal stromal cells did not differentiate into mature cardiomyocytes, addition of these cells increased the rate of fiber formation, force production, and work and power outputs. Self-organized cardiac tissue containing mesenchymal stromal cells acquired a defined microscopic architecture.
  
  
  CONCLUSIONS
  Discarded thymus tissue contains mesenchymal stromal cells, which can augment force production and work and power outputs of self-organized cardiac tissue fibers by several-fold. These findings indicate the potential utility of mesenchymal stromal cells in treating heart failure.
authors: Stem Cell Program, University of California Davis, Sacramento, California, USA.
authors: Claus S
authors: CS
authors: Sondergaard
authors: Chani J
authors: CJ
authors: Hodonsky
authors: Luda
authors: L
authors: Khait
authors: John
authors: J
authors: Shaw
authors: Bedabrata
authors: B
authors: Sarkar
authors: Ravi
authors: R
authors: Birla
authors: Edward
authors: E
authors: Bove
authors: Jan
authors: J
authors: Nolta
authors: Ming-Sing
authors: MS
authors: Si
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D008648:Mesoderm / Q000166:cytology*; D051381:Rats; D011916:Rats, Inbred F344; D017154:Stromal Cells; D013950:Thymus Gland / Q000166:cytology*; D046509:Tissue Culture Techniques