Isolation and characterization of human rotator cuff tendon stem cells
Erika Conforti1,2, Marco Piccoli1,2, Pasquale Creo1,2, Federica Cirillo1,2, Sonia Bergante1,2, Alessandra Menon1,2, Andrea Ghiroldi1,2, Vicenza Ragone1,2, Pamela Masuzzo1,2, Paolo Cabitza1,2, Guido Tettamanti1,2, Nicoletta Gagliano1,2, Pietro Randelli1,2, Luigi Anastasia1,2
1Laboratory of Stem Cell for Tissue Enegineering, IRCCS Policlinico San Donato, San Donato Milanese, Italy; 2Department of Biomedical Science for Health, University of Milan, Milan, Italy
Rotator cuff (RC) tendons are often prone to lesions and raptures, as 30 to 50% of the population over fifty suffers of partial- and full-thickness RC tears. Several approaches have been developed over the years, including the use of growth factors, bone morphogenetic proteins and, more recently, stem cells. Among adult stem cells, bone marrow mesenchymal stromal cells (BMSCs) are by far the most studied, although tendon-derived progenitor cells (TSPCs) have been found in several animal species, including humans [
1,
2]. However, the isolation of a cell population with stem cells characteristics from the human rotator cuff has yet to be reported.
Methods:Human tendon samples (from the supraspinatus and the long head of the biceps) were collected during rotator cuff tendon surgeries from 26 patients, washed with PBS, cut into small pieces, and digested with collagenase type I and dispase. After centrifugation, cell pellets were resuspended in appropriate culture medium and plated. Adherent cells were cultured, phenotypically characterized, and then compared to human bone marrow stem cells (BMSC), as an example of adult stem cells, and human dermal fibroblasts, as normal proliferating cells with no stem cell properties.
Results:Two new adult stem cell populations (from the supraspinatus and from the long head of the biceps tendons) were isolated, characterized, and cultured in vitro. Cells showed adult stem cell characteristics, i.e. they were self-renewing in vitro, clonogenic, and multipotent, as they could be induced to differentiate into different cell types, namely osteoblasts, adipocytes and skeletal muscle cells.
Conclusion: This work demonstrated that human rotator cuff tendon stem cells (HRCSC) and human long head of the biceps tendon stem cells (HLHBSC) can be isolated and possess a high regenerative potential, which is comparable to that of BMSC [3]. Moreover, comparative analysis of the sphingolipid pattern of isolated cells with that of BMSC and fibroblasts revealed the possibility of using this class of lipids as new possible markers of the cell differentiation status.
Clinical Relevance:Rotator cuff and long head of the biceps tendons contain a stem cell population that can proliferate in vitro and could constitute an easily accessible stem cell source to develop novel therapies for tendon regeneration.
1. Lui, P. P., and Chan, K. M. (2011) Stem cell reviews 7, 883-897
2. Bi, Y., Ehirchiou, D., Kilts, T. M., Inkson, C. A., Embree, M. C., Sonoyama, W., Li, L., Leet, A. I., Seo, B. M., Zhang, L., Shi, S., and Young, M. F. (2007) Nature medicine 13, 1219-1227
3. Randelli P., Conforti E., Piccoli M., Ragone V., Creo P., Cirillo F., Masuzzo P., Tringali C., Cabitza P., Tettamanti G., Gagliano N., Anastasia L. (2013) Am. J. Sports Medicine, Feb 7, in press