Trachana V, Petrakis S, Fotiadis Z, Siska EK, Balis V, Gonos ES, Kaloyianni M, Koliakos G. Human mesenchymal stem cells with enhanced telomerase activity acquire resistance against oxidative stress-induced genomic damage.
Cytotherapy 2017;
19:808-820. [PMID:
28454681 DOI:
10.1016/j.jcyt.2017.03.078]
[Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 03/25/2017] [Accepted: 03/25/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND
Human mesenchymal stem cells (MSC) are important tools for several cell-based therapies. However, their use in such therapies requires in vitro expansion during which MSCs quickly reach replicative senescence. Replicative senescence has been linked to macromolecular damage, and especially oxidative stress-induced DNA damage. Recent studies on the other hand, have implicated telomerase in the cellular response to oxidative damage, suggesting that telomerase has a telomere-length independent function that promotes survival.
METHODS
Here, we studied the DNA damage accumulation and repair during in vitro expansion as well as after acute external oxidative exposure of control MSCs and MSCs that overexpress the catalytic subunit of telomerase (hTERT MSCs).
RESULTS
We showed that hTERT MSCs at high passages have a significant lower percentage of DNA lesions as compared to control cells of the same passages. Additionally, less damage was accumulated due to external oxidative insult in the nuclei of hTERT overexpressing cells as compared to the control cells. Moreover, we demonstrated that oxidative stress leads to diverse nucleus malformations, such as multillobular nuclei or donut-shaped nuclei, in the control cells whereas hTERT MSCs showed significant resistance to the formation of such defects. Finally, hTERT MSCs were found to possess higher activities of the basic antioxidant enzymes, superoxide dismutase and catalase, than control MSCs.
DISCUSSION
On the basis of these results, we propose that hTERT enhancement confers resistance to genomic damage due to the amelioration of the cell's basic antioxidant machinery.
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