French researchers were able to restore theÂ youthÂ of cells taken from people aged over 100 years, reprograming them to stem cells stage, demonstrating that aging isÂ in factÂ reversible. The research on the possibility to remove traces left byÂ aging cells, published in the Genes & DevelopmentÂ journalÂ , marks a new stageÂ in theÂ regenerative medicine field, said Jean-Marc Lemaitre from Fonctionnelle GÃ©nomique Institute (INSERM / CNRS / UniversitÃ© de Montpellier), who led the study, informs AFP.
The study contributed to another important achievement: a better understanding of aging and its pathological aspects correction, say scientists at INSERM.
Old cells were reprogrammed to beÂ pluripotent stem cells in vitro – IPSC (Induced pluripotent stem cells), which have theÂ youth and characteristics of embryonic stem cells (hESC). They can differentiate back into cells of all types (neurons, heart cells, epithelial, liver etc)Â after the “rejuvenation”Â cureÂ made byÂ French scientists.
Since 2007, scientists have shown that they can reprogram adult cellsÂ into pluripotent human stem cells (IPSC), whose properties are similar to those of embryonic stem cells. Those reprogrammed adult cells fromÂ avoid the criticisms regarding the use of embryonic stem cells.
Before the greatÂ success of French researchers, reprogramming adult cellsÂ hit a limit, senescence, cellular aging ultimate point. The team of scientists led by Jean-Marc Lemaitre managed to exceed this limit.
The researchers first multiplied epithelial cells (fibroblasts) from a donor aged 74 years to reach senescence, characterized by cessation of cell multiplication process. The researchers then conductedÂ an in vitro reprogramming of these cells. Since this process wasÂ not possibleÂ through clasic preparationÂ based onÂ four genetic factors (OCT4, Sox2, Myc and KLF4 C), they added two more (NANOG and LIN28).
With this new “cocktail” of six ingredients, reprogrammed senescent cells have regained the characteristics of pluripotent stem cells embryonic type without any trace of aging to preserve their past. Age markers were deleted fromÂ cells and the IPSC (Induced pluripotent stem cells)Â that were obtained can produce all type ofÂ functional cells, with multiplication capacityÂ and increased longevity.
Researchers then tested the “cocktail”Â on older cells, aged 92 years, 94 years, 96 years and 101 years, the same success is achieved each time, including for theÂ 101 year old cells.
“Age is certainly notÂ a barrierÂ forÂ cell reprogramming,” concluded the research leader.
This study opens the way for usingÂ reprogrammedÂ IPS cells as a sourceÂ ofÂ adult cells ideally tolerated by the immune system to repair damaged organs or tissues in elderly patients.