Table 7.
The induction of apoptosis in post-thaw BM-MSCs
| Study | Species | Results post-thaw | Method of assessment |
|---|---|---|---|
| Apoptosis | |||
| Human | |||
| Liu et al. [28] | Human | Serum-free reduced-DMSO freezing solution gives comparable apoptotic percentage to 10% DMSO | Flow cytometry |
| Ginis et al. [50] | Human | Lower percentage of apoptotic cells obtained with Annexin V and Hoechst staining compared to caspase 3 assay: using caspase 3, the percentage of apoptotic cells was between 13 and 17% for CryStor media compared to 3% for conventional freezing media | Flow cytometry—Annexin V, Hoechst, Caspase 3 activity |
| Chinnadurai et al. [20] | Human | Higher percentage of apoptotic cells in cryopreserved MSC than live MSC | Flow cytometry |
| Moll et al. [38] | Human | Apoptosis increased by cryopreservation when exposed to human serum | Flow cytometry—Annexin V, PI staining |
| Other species | |||
| Ock and Rho [51] | Pig | Bak and Bcl2 gene expression in cryopreserved cells was higher than fresh at 3 h post-thaw: Bak and Bcl2 gene expression in cryopreserved cells was comparable to fresh after culturing thawed cells up to 90% confluence: Bcl2 antigen expression level was comparable to fresh after culturing thawed cells up to 90% confluence | RT-qPCR for Bak and Bcl2: Flow cytometry; Bcl2 antigen |
| Romanek et al. [98] | Pig (BM-MSC treated with HHP before freezing) | No significant difference between control (without HHP) and cells subjected to HHP pre-freeze | Flow cytometry—Annexin V: Fluorescence microscopy |
| Senescence | |||
| Human | |||
| Mamidi et al. [33] | Human | No difference in the level of senescent cells | Β-galactosidase assay |
| Al-Saqi et al. [66] | Human | There were signs of senescence (but could be due to culture medium rather than cryopreservation medium) | Β-galactosidase assay (analysed 2 passages after cryopreservation) |
| Pollock et al. [67] | Human | Immediate pre-freeze senescence levels show similar trends but higher levels compared to pre-freeze At 48 h post-thaw, level of senescent cells dropped significantly comparing to immediately post-thaw | Beta-glo assay |
The key results on bone-marrow derived mesenchymal stem cell apoptotic activity post-thaw are presented in this table. For further details on the cryopreservation experimental details refer to either Table 1 or Additional file 2 which provide the individual freezing protocols outlined in the extracted papers alongside the concentration and passage of cells at the point of cryopreservation and the process of thawing