"
Prolonged Growth Hormone/Insulin/Insulin-like Growth Factor
Nutrient Response Signaling Pathway as a Silent Killer of Stem
Cells and a Culprit in Aging
"
Abstract
"
The dream of slowing down the aging process has
always inspired mankind. Since stem cells are responsible for
tissue and organ rejuvenation, it is logical that we should
search for encoded mechanisms affecting life span in these
cells. However, in adult life the hierarchy within the stem cell
compartment is still not very well defined, and evidence has
accumulated that adult tissues contain rare stem cells that pos-
sess a broad trans-germ layer differentiation potential. These
most-primitive stem cells
those endowed with pluripotent or
multipotent differentiation ability and that give rise to other
cells more restricted in differentiation, known as tissue-
committed stem cells (TCSCs) - are of particular interest. In
this review we present the concept supported by accumulating
evidence that a population of so-called very small embryonic-
like stem cells (VSELs) residing in adult tissues positively
impacts the overall survival of mammals, including humans.
These unique cells are prevented in vertebrates from prema-
ture depletion by decreased sensitivity to growth hormone
(GH), insulin (INS), and insulin-like growth factor (IGF) sig-
naling, due to EPIGENETIC CHANGES IN PATERNALLY
IMPRINTED GENES THAT REGULATE THEIR RESISTANCE
TO THESE FACTORS. In this
context, we can envision nutrient response GH/INS/IGF sig-
naling pathway as a lethal factor for these most primitive stem
cells and an important culprit in aging.
"
http://link.springer...2015-017-9728-2
