title: Assessing in vitro stem-cell function and tracking engraftment of stem cells in ischaemic hearts by using novel iRFP gene labelling.
abstract: Near-infrared fluorescence (NIRF) imaging by using infrared fluorescent protein (iRFP) gene labelling is a novel technology with potential value for in vivo applications. In this study, we expressed iRFP in mouse cardiac progenitor cells (CPC) by lentiviral vector and demonstrated that the iRFP-labelled CPC (CPC(iRFP)) can be detected by flow cytometry and fluorescent microscopy. We observed a linear correlation in vitro between cell numbers and infrared signal intensity by using the multiSpectral imaging system. CPC(iRFP) injected into the non-ischaemic mouse hindlimb were also readily detected by whole-animal NIRF imaging. We then compared iRFP against green fluorescent protein (GFP) for tracking survival of engrafted CPC in mouse ischaemic heart tissue. GFP-labelled CPC (CPC(GFP)) or CPC labelled with both iRFP and GFP (CPC(iRFP) (GFP)) were injected intramyocardially into mouse hearts after infarction. Three days after cell transplantation, a strong NIRF signal was detected in hearts into which CPC(iRFP) (GFP), but not CPC(GFP), were transplanted. Furthermore, iRFP fluorescence from engrafted CPC(iRFP) (GFP) was detected in tissue sections by confocal microscopy. In conclusion, the iRFP-labelling system provides a valuable molecular imaging tool to track the fate of transplanted progenitor cells in vivo.
authors.affiliation: Internal Medicine of Traditional Chinese Medicine, Shuguang Hospital of Shanghai University of Traditional Chinese Medicine, Shanghai, China; Department of Medicine, University of Cincinnati, Cincinnati, OH, USA.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Wang
authors.forename: Mi
authors.initials: M
authors.lastname: Zhou
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Wang
authors.forename: Gangjian
authors.initials: G
authors.lastname: Qin
authors.forename: Neal L
authors.initials: NL
authors.lastname: Weintraub
authors.forename: Yaoliang
authors.initials: Y
authors.lastname: Tang
mesh_terms: D053687:Adult Stem Cells / Q000378:metabolism* / Q000637:transplantation; D000818:Animals; D002465:Cell Movement; D058948:Cell Tracking; D007259:Infrared Rays; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D018482:Muscle, Skeletal / Q000473:pathology; D017202:Myocardial Ischemia / Q000473:pathology*; D009206:Myocardium / Q000473:pathology; D000097573:Red Fluorescent Protein
chemical_list: D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein
keywords: GFP; cell transplantation; iRFP; myocardial infarction; stem cells