Spore-like cell

Characteristics

Spore-like cells were said to be a specific class of stem cells in adult organisms, including humans, which are small, versatile, and most frequently remain in a dormant "spore-like" state as the rest of the cells of the organism divide, grow, and die. Despite their dormancy, they apparently retain the ability to grow, divide, and differentiate into other cell types expressing characteristics appropriate to the tissue environment from which they were initially isolated, if some external stimulus should prompt them to do so. This capacity to continue to regenerate new cells has been shown in in vitro conditions for some animals in which all other cells have died, especially if the animal died from exposure to cold elements.

Spore-like cells were said to remain viable in unprepared tissue (using no special preservation techniques), frozen at -86 °C and then thawed, or heated to 85 °C for more than 30 minutes. This has led researchers to try to revitalize spore-like cells from tissue samples of frozen carcasses deposited in permafrost for decades (frozen walrus meat more than 100 years old, and mammoth and bison in Alaska estimated to be 50,000 years old). Vacanti et al. believed that these unique cells lie dormant until activated by injury or disease, and that they have the potential to regenerate tissues lost to disease or damage. Because the cell-size of less than 5 micrometers seems rather small as to contain the entire human genome the authors speculate on the "concept of a minimal genome" for these cells.

Later work

Main article: STAP cells

Charles Vacanti continued to work on these cells when he moved to Harvard, including with thoracic surgeon Koji Kojima who identified them in lung tissue. and then in January 2014 the journal Nature published two articles suggesting that a simple acid treatment could cause mouse blood cells to become pluripotent. Both STAP articles were retracted in July 2014 after an investigation by RIKEN concluded that the data were fabricated.

Researcher Mariusz Ratajczak has linked spore-like cells to his idea of Very small embryonic-like stem cells, also proposed to be very small adult stem cells.

References

References

1. (2001). "Identification and initial characterization of spore-like cells in adult mammals". J. Cell. Biochem..
2. Foreman, Judy. (December 30, 2003). "SCIENTISTS AT WORK -- JOSEPH, CHARLES, MARTIN AND FRANCIS VACANTI; From Old Cars to Cartilage, Brothers Like to Tinker". New York Times.
3. Marcus, Adam. (July 2012). "Tissue-Engineering Anesthesiologist Redefines Stem Cells". Anesthesiology News.
4. Johnson, Carolyn Y. (February 2, 2014). "Ignorance led to invention of stem cell technique". Boston Globe.
5. Cyranowski, David. (September 12, 2014). "STAP co-author offers yet another recipe for stem cells". Nature News Blog.
6. (February 18, 2015). "What pushes scientists to lie? The disturbing but familiar story of Haruko Obokata". The Guardian.
7. (September 2014). "Very small embryonic-like stem cells as a novel developmental concept and the hierarchy of the stem cell compartment". Advances in Medical Sciences.