Cardiovascular Research Advance Access originally published online on May 20, 2009
Cardiovascular Research 2009 83(4):707-716; doi:10.1093/cvr/cvp159
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Human cardiac mesoangioblasts isolated from hypertrophic cardiomyopathies are greatly reduced in proliferation and differentiation potency
1 Division of Regenerative Medicine, San Raffaele Scientific Institute, 58 Via Olgettina, 20132 Milan, Italy
2 Department of Experimental Medicine, University of Milano-Bicocca, Milan, Italy
3 Stem Cell Research Institut, University Hospital Gasthuisberg, Leuven, Belgium
4 Cardiology, Faculty of Medicine, University La Sapienza, Rome, Italy
5 Department of Cardiovascular Research, Mario Negri Institute, Milan, Italy
6 Department of Cardiovascular Surgery, San Raffaele Scientific Institute, Milan, Italy
7 Department of Biology, University of Milan, Milan, Italy
* Corresponding author. Tel: +39 022 643 4954; fax: +39 022 643 4621. E-mail address: bggalvez{at}hotmail.com
Aims: Our objective was to test whether progenitor cell proliferation and differentiation potential may vary depending upon the disease of the donor.
Methods and results: Human cardiac mesoangioblasts were isolated from cardiac muscle biopsies of patients undergoing open heart surgery for correction of mitral regurgitation following an acute myocardial infarction (MR-MI) or correction of mitral and aortic regurgitation with ensuing left ventricular hypertrophy (MAR-LVH). The cells express surface markers and cardiac genes similar to mouse cardiac mesoangioblasts; they have limited self-renewing and clonogenic activity and are committed mainly to cardiogenesis. Although cardiac differentiation can be induced by 5-azacytidine or by co-culture with rat neonatal cardiomyocytes, human cells do not contract spontaneously like their mouse counterparts. When locally injected in the infarcted myocardium of immunodeficient mice, cardiac mesoangioblasts generate a chimeric heart that contains human myocytes and some capillaries; likewise, they colonize chick embryo hearts when transplanted in ovo. At variance with cells from patients with MR-MI, when isolation was performed on biopsies from MAR-LVH, cells could be isolated in much lower numbers, proliferated less extensively and failed to differentiate.
Conclusion: Cardiac mesoangioblasts are present in the human heart but this endogenous progenitor population is progressively exhausted, possibly by continuous and inefficient regeneration attempts.
KEYWORDS Regeneration; Mitral regurgitation; Hypertrophy; Mesoangioblasts
Time for primary review: 24 days