C-2008: Investigation of the effects of cryopreservation on the histone modification patterns of mesenchymal stem cells

• Published in: Cryobiology 2014-12, Vol.69 (3), p.518-518
• Main Authors: Chatterjee, A., Hofmann, N., Glasmacher, B.
• Format: Article
• Language: English
• Subjects: Callithrix
• ISSN: 0011-2240; 1090-2392
• DOI: 10.1016/j.cryobiol.2014.09.355

Mesenchymal stem cells (MSCs) are multipotent adult stem cells and have diverse potential biomedical applications such as in tissue repair, transplantation and cell-based therapies. Cryopreservation of MSCs allows long term storage of these cells and therefore plays a crucial role in their subsequent applications. The success of a cryopreservation protocol is often assessed by analyzing the survival rates of thawed cells. However this parameter does not provide information on the possible adverse cellular effects of cryopreservation, such as on gene expression regulation and cell fate decisions. Treatment with Me2SO has been shown to impact the histone modification patterns and the DNA methylation patterns of various tissues. Histone modifications and DNA methylation are epigenetic mechanisms that regulate eukaryotic transcription without altering the DNA sequence. Epigenetic mechanisms play an important role in stem cell maintenance and differentiation and when deregulated may lead to the formation of diseases like cancer. Despite the widespread cryopreservation of MSCs with Me2SO, the effects of cryopreservation on the epigenetic mechanisms of MSCs are yet to be fully evaluated. In the current study bone marrow derived-MSCs from the common marmoset monkey were frozen with different concentrations of Me2SO using a controlled-rate freezing device. Post-thaw cell viability was examined by analyzing the membrane integrity (by trypan blue staining) and mitochondrial dehydrogenase activity (using MTT assay). The functional integrity of cryopreserved MSCs was tested by analyzing their ability to differentiate into adipogenic and osteogenic lineages. The global acetylation and methylation patterns of the different histone proteins were analyzed using immunocytochemistry and mass-spectrometry. Results indicated that the survival, differentiation ability and modification patterns of various histone proteins in mesenchymal stem cells may be altered after cryopreservation, depending on the concentration of Me2SO used for cryopreservation.