This approach for the isolation and characterization of a new population of adipose tissue (AT) derived pluripotent stem cells could represent a breakthrough. The authors have identified these cells as "Multilineage Differentiating Stress-Enduring (MUSE) Cells": Heneidi S, Simerman AA, Keller E, Singh P, Li X, et al. (2013) Awakened by Cellular Stress: Isolation and Characterization of a Novel Population of Pluripotent Stem Cells Derived from Human Adipose Tissue. PLoS ONE 8(6): e64752. doi:10.1371/journal.pone.0064752.
Highlights: Although adult stem cells have been considered an attractive source for cell therapy, their effectiveness and efficiency is hindered by a frequently low survival rate due to their exposure to a high cellular stress environment upon transplantation. This key limitation is observed when utilizing adult stem cells for regenerative purposes, as typical cell engraftment yields are extremely low (less than 3%). This low survival rate limiting in the use of stem cells for therapies.
The authors have developed methods for isolating MUSE Cells that are preconditioned to survive engraftments. These cells display down regulation of genes involved in cell death and survival, embryonic development, organism survival, cellular assembly and organization, mitosis, DNA replication, recombination and repair.
Figure 1. Isolation and morphologic characterization of Muse-ATs. (A) Schematic of Muse-AT isolation and activation from their quiescent state by exposure to cellular stress. Muse-AT cells were obtained after 16 hours, with incubation with collagenase in DMEM medium without FCS at 4°C under very low O2 (See Methods). (B) FACS analysis demonstrates that 90% of isolated cells are both SSEA3 and CD105 positive. (C) Muse-AT cells can grow in suspension, forming spheres or cell clusters as well as individual cells (see red arrows) or (D) Muse-AT cells can adhere to the dish and form cell aggregates. Under both conditions, individual Muse-AT cells reached a diameter of approximately 10µm and cell clusters reached a diameter of up to 50µm, correlating to stem cell proliferative size capacity. doi:10.1371/journal.pone.0064752.g001.