Telomerase activity and expression in adult human mesenchymal stem cells derived from amyotrophic lateral sclerosis individuals
Telomerase is a ribonucleoprotein that maintains the length of telomeres, and thus controls the proliferation and lifespan of cells. Recent studies suggest the involvement of telomerase in the protection of cells from apoptosis. Adult human mesenchymal stromal cells (hMSC) possess the capacity to proliferate and differentiate into a variety of cell types. hMSC derived from a healthy donor lack telomerase activity but their expression has not been investigated in hMSC derived from diseased adults. Cell replacement therapy using adult hMSC has been suggested as a promising therapeutic approach for amyotrophic lateral sclerosis (ALS). Therefore, we characterized the telomerase activity and expression in hMSC derived from bone marrow (BM) of ALS patients and compared them with those derived from a healthy donor. Telomerase activity was examined with a TRAP assay and real-time polymerase chain reaction telomerase quantification assay. Telomerase protein was detected by Western blot and immunofluorescence analysis, and telomerase RNA transcripts were identified by Northern blot. Telomerase activity, telomerase enzyme protein and telomerase RNA transcripts were demonstrated in hMSC derived from ALS, but were undetectable in hMSC from the healthy donor. Telomerase activity in the hMSC of ALS patients was 106-fold lower compared with tumor cells. The detection of telomerase expression in hMSC derived from ALS patients and not a healthy donor suggests a possible role for telomerase in the response of hMSC to the disease. The presence of telomerase expression did not impair the ability of the ALS hMSC to differentiate, suggesting the use of these cells for cytotherapy treatments.