Inserm's AVENIR "Genomic plasticity and aging" group, focused by Jean-Marc Lemaitre, Inserm specialist at the Sensible Genomics Company (Inserm/CNRS/Université de Montpellier 1 and 2) carried out the investigation. The success were publicized in Genetics & Development on We have seen 1, 2011.
Human embryonic control tissue (hESC) are undifferentiated multiple-function tissue. They can split and form all kinds of separated mature tissue in the body (neurons, heart tissue, skin tissue, liver organ tissue, etc.). Since 2007, a few investigation organizations across the world have been capable of reprogramming human being mature tissue into stimulated pluripotent tissue (iPSC), which have similar features and potential to human being embryonic control tissue (hESC). This kind of reprogramming makes it possible to change all human being cell kinds without the honest rules related to using embryonic control tissue.
Until now, investigation success proven that senescence (the final level of cell phone aging) was an obstruction keeping the use of this approach for healing programs in old people. Today, Inserm specialist Jean-Marc Lemaitre and his group have conquer this obstruction. The experts have properly energized tissue from old contributors, some over 100 years old, thus indicating the reversibility of the cell phone ageing.
To achieve this, they used an used strategy that contains reprogramming tissue using a specific "cocktail" of six genetics, while getting rid of wrinkles. The experts proven that the iPSC tissue thus acquired then had the potential to change all kinds of human being tissue. They have the biological features of "young" tissue, both from the view of their proliferative potential and their cell phone metabolisms.
A cocktail of six genetic factors...
Researchers first multiplied skin cells (fibroblasts) from a 74 year-old donor to obtain the senescence characterized by the end of cellular proliferation. They then completed the in vitro reprogramming of the cells. In this study, Jean-Marc Lemaitre and his team firstly confirmed that this was not possible using the batch of four genetic factors (OCT4, SOX2, C MYC and KLF4) traditionally used. They then added two additional factors (NANOG and LIN28) that made it possible to overcome this barrier.
Using this new "cocktail" of six factors, the senescent cells, programmed into functional iPSC cells, re-acquired the characteristics of embryonic pluripotent stem cells.
In particular, they recovered their capacity for self-renewal and their former differentiation potential, and do not preserve any traces of previous aging. To check the "rejuvenated" characteristics of these cells, the researchers tested the reverse process. The rejuvenated iPSC cells were again differentiated to adult cells and compared to the original old cells, as well as to those obtained using human embryonic pluripotetent stem cells (hESC).
"Signs of aging were erased and the iPSCs obtained can produce functional cells, of any type, with an increased proliferation capacity and longevity," explains Jean-Marc Lemaitre who directs the Inserm AVENIR team.
…tested on cells taken from donors over the age of 100
The results obtained led the research team to test the cocktail on even older cells taken from donors of 92, 94 and 96, and even up to 101 years old. "Our strategy worked on cells taken from donors in their 100s. The age of cells is definitely not a reprogramming barrier." He concluded. "This research paves the way for the therapeutic use of iPS, insofar as an ideal source of adult cells is provided, which are tolerated by the immune system and can repair organs or tissues in elderly patients." adds the researcher.
