Isolation of "side population" progenitor cells from healthy arteries of adult mice.
OBJECTIVE
Circulating progenitors and stem cells have been reported to contribute to angiogenesis and arterial repair after injury. In the present study, we investigated whether the arterial wall could host permanently residing progenitor cells under physiological context.


RESULTS
Using the Hoechst-based flow cytometry method, we identified and isolated progenitor cells termed side population (SP) cells at a prevalence of 6.0+/-0.8% in the tunica media of adult mice aortas. Arterial SP cells expressed the ATP-binding cassette transporter subfamily G member 2, frequently present on SP cell surface, and displayed a Sca-1+ c-kit(-/low) Lin- CD34(-/low) profile. They did not form myeloid or lymphoid hematopoietic colonies after plating in methylcellulose-based medium. Importantly, cultured SP cells were able to acquire the phenotype of endothelial cells (CD31, VE-cadherin, and von Willebrand factor expression) or of smooth muscle cells (alpha-smooth muscle actin, calponin, and smooth muscle myosin heavy chain expression), in presence of either vascular endothelial growth factor or transforming growth factor (TGF)-beta1/PDGF-BB, respectively. Moreover, they generated vascular-like branching structures, composed of both VE-cadherin+ cells and alpha-smooth muscle actin+ cells on Matrigel.


CONCLUSIONS
In this study, we provide the first evidence to our knowledge that in the adult mice, the normal arterial wall harbors SP cells with vascular progenitor properties.
Sainz
Julie
J
INSERM E-0016, Faculté de Médecine Paris V, Université René Descartes, Paris, France. sainz@necker.fr
Al Haj Zen
Ayman
A
Caligiuri
Giuseppina
G
Demerens
Corinne
C
Urbain
Dominique
D
Lemitre
Mathilde
M
Lafont
Antoine
A
D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000367:Age Factors; D000818:Animals; D001012:Aorta, Abdominal / Q000166:cytology*; D001013:Aorta, Thoracic / Q000166:cytology*; D001672:Biocompatible Materials; D015415:Biomarkers; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation; D002469:Cell Separation / Q000379:methods*; D003094:Collagen; D004338:Drug Combinations; D005260:Female; D005434:Flow Cytometry; D007797:Laminin; D008747:Methylcellulose; D051379:Mice; D008810:Mice, Inbred C57BL; D010641:Phenotype; D011509:Proteoglycans; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D017540:Tunica Media / Q000166:cytology
D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; C501412:Abcg2 protein, mouse; D001672:Biocompatible Materials; D015415:Biomarkers; D004338:Drug Combinations; D007797:Laminin; D011509:Proteoglycans; C059485:matrigel; D008747:Methylcellulose; D003094:Collagen