Stem-cell-based therapies, particularly ones utilizing human adipose-derived stem cells (ASCs), are becoming increasingly popular in the field of regenerative medicine. This is due to the relative ease of isolating ASCs from fat tissue compared to other stem cell subtypes. ASCs also play a role in modulating the immune system with anti-inflammatory cytokines and have the capacity to differentiate into cell types like fat, bone, and vascular tissue to promote regeneration in damaged, diseased, or aging cells. Despite the many promising characteristics of ASCs, their therapeutic potential is limited by reduced viability caused by their sensitivity to various stress factors that they are commonly exposed to during their use. These stressors include shear stress from needle injections, metabolic stress following transplantation, and exposure to DMSO during cryopreservation, which triggers increased reactive oxygen species (ROS) production leading to cell death.
Transgenic expression of proteins from extremophiles—organisms that thrive in extreme environments—are garnering attention for their potential to improve the stress tolerance of mammalian cells. Tardigrades are microscopic extremophiles that can enter a quiescent state capable of surviving radiation, desiccation, and extreme temperatures. They are a rich source of the mitochondrial abundant heat soluble (MAHS) protein, which has been shown to improve cell survival under osmotic stress without altering cell morphology.
In a 2024 publication in Scientific Reports, Rolsma et al. evaluated the transgenic expression of the MAHS protein in ASCs to determine whether it could enhance their tolerance to DMSO exposure, injection stress, and metabolic stress. MAHS-transgenic ASCs were stained with Biotium’s MitoView™ Fix 640 to confirm that the MAHS protein localized to mitochondria. The researchers assessed the effects of MAHS on the ASCs tolerance to freezing, DMSO, and passage through injection needles of varying diameters using Biotium’s Viability/Cytotoxicity Assay Kit for Animal Live & Dead Cells. The results suggest that ASCs expressing MAHS from tardigrades had significantly higher survival rates with needle shear stress and DMSO exposure. However, MAHS-transgenic ASCs showed no improvement in resistance to freezing, which contrasts with the natural freezing resistance observed in tardigrades. This highlights a limitation in the application of MAHS to cold storage or cryopreservation of ASCs. Lastly, the study assessed the effects of MAHS expression on ASC differentiation. The MAHS-transgenic ASCs preferentally differentiated toward osteogenic over adipogenic lineages.
The findings highlight the need for further research to fully understand the mechanisms by which MAHS influences cell differentiation and explore its application in other types of cells for regenerative medicine. By improving the resilience of stem cells to various stress factors, MAHS expression could pave the way for more reliable, efficient, and patient-friendly therapies.
Learn more about Biotium’s MitoView™ Fix 640 and other MitoView™ Mitochondrial Dyes that rapidly accumulate in mitochondria and can be imaged without washing. Also explore Biotium’s full selection of Proliferation & Viability Assays.
Full Citation:
Rolsma, J.L., Darch, W., Higgins, N.C. et al. The tardigrade-derived mitochondrial abundant heat soluble protein improves adipose-derived stem cell survival against representative stressors. Sci Rep 14, 11834 (2024). https://doi.org/10.1038/s41598-024-62693-w