Int J Med Sci 2013; 10(8):1035-1046. doi:10.7150/ijms.6639 This issue

Research Paper

Establishment and Characterization of the Reversibly Immortalized Mouse Fetal Heart Progenitors

Mi Li1,2, Yuan Chen1, Yang Bi1,2, Wei Jiang2, Qing Luo1,2, Yun He1,2, Yuxi Su1,2, Xing Liu1,2, Jing Cui2,3, Wenwen Zhang2,3, Ruidong Li2,3, Yuhan Kong2,3, Jiye Zhang2,3, Jinhua Wang2,3, Hongyu Zhang2,3, Wei Shui2,3, Ningning Wu2,3, Jing Zhu1, Jie Tian1, Qi-Jian Yi1, Hue H. Luu2, Rex C. Haydon2, Tong-Chuan He1,3✉, Gao-Hui Zhu1✉

1. Stem Cell Biology and Therapy Laboratory, the Key Laboratory of Pediatrics Designated by Chinese Ministry of Education and Chongqing Bureau of Education, and the Children's Hospital of Chongqing Medical University, Chongqing 400014, China
2. Molecular Oncology Laboratory, Department of Orthopaedic Surgery, The University of Chicago Medical Center, Chicago, IL 60637, USA
3. Key Laboratory of Diagnostic Medicine designated by Chinese Ministry of Education, and The Affiliated Hospitals of Chongqing Medical University, Chongqing 400016, China

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) License. See for full terms and conditions.
Li M, Chen Y, Bi Y, Jiang W, Luo Q, He Y, Su Y, Liu X, Cui J, Zhang W, Li R, Kong Y, Zhang J, Wang J, Zhang H, Shui W, Wu N, Zhu J, Tian J, Yi QJ, Luu HH, Haydon RC, He TC, Zhu GH. Establishment and Characterization of the Reversibly Immortalized Mouse Fetal Heart Progenitors. Int J Med Sci 2013; 10(8):1035-1046. doi:10.7150/ijms.6639. Available from

File import instruction


Objective: Progenitor cell-based cardiomyocyte regeneration holds great promise of repairing an injured heart. Although cardiomyogenic differentiation has been reported for a variety of progenitor cell types, the biological factors that regulate effective cardiomyogenesis remain largely undefined. Primary cardiomyogenic progenitors (CPs) have a limited life span in culture, hampering the CPs' in vitro and in vivo studies. The objective of this study is to investigate if primary CPs isolated from fetal mouse heart can be reversibly immortalized with SV40 large T and maintain long-term cell proliferation without compromising cardiomyogenic differentiation potential.

Methods: Primary cardiomyocytes were isolated from mouse E15.5 fetal heart, and immortalized retrovirally with the expression of SV40 large T antigen flanked with loxP sites. Expression of cardiomyogenic markers were determined by quantitative RT-PCR and immunofluorescence staining. The immortalization phenotype was reversed by using an adenovirus-mediated expression of the Cre reconbinase. Cardiomyogenic differentiation induced by retinoids or dexamethasone was assessed by an α-myosin heavy chain (MyHC) promoter-driven reporter.

Results: We demonstrate that the CPs derived from mouse E15.5 fetal heart can be efficiently immortalized by SV40 T antigen. The conditionally immortalized CPs (iCP15 clones) exhibit an increased proliferative activity and are able to maintain long-term proliferation, which can be reversed by Cre recombinase. The iCP15 cells express cardiomyogenic markers and retain differentiation potential as they can undergo terminal differentiate into cardiomyctes under appropriate differentiation conditions although the iCP15 clones represent a large repertoire of CPs at various differentiation stages. The removal of SV40 large T increases the iCPs' differentiation potential. Thus, the iCPs not only maintain long-term cell proliferative activity but also retain cardiomyogenic differentiation potential.

Conclusions: Our results suggest that the reported reversible SV40 T antigen-mediated immortalization represents an efficient approach for establishing long-term culture of primary cardiomyogenic progenitors for basic and translational research.

Keywords: Cardiomyogenic progenitors, cardiomyogenic differentiation, cardiomyogenesis, cardiovascular disorders, heart progenitor cells, immortalization