- Aging of the section of the bone marrow responsible for producing hematopoietic stem cells results in the aging of these cells.
- This is found to
increase the risk of poor immunity as well as the risk for certain types
of blood cancer.
- Rejuvenating the
section of the bone marrow is suggested to be a potential form of therapy
to improve vitality of stem cells.
Hematopoietic stem cells
(HSCs) are found to age as people age, resulting in higher risk for certain
types of blood cancer
and an elevated risk for lowered
immunity. A study published in the journal EMBO has shown that a section of the
bone marrow where hematopoietic stem cells are formed, also age, aggravating
the risk for the disease.
A research team from the University of
Ulm (Germany) along with scientists from Cincinnati Children's Hospital Medical
Center(United States)have stated that rejuvenating the section of the bone
marrow where hematopoietic stem cells are formed would ensure
hematopoietic stem cells which result in healthier blood cells
immunity among older people
- A more
potent defense response against
some types of blood cancer
The study was conducted
on mice, specifically on a group of stem cells that lead to the development of
called osteopontin produced by the osteoblasts is necessary for the healthy
environment of the bone marrow which is imperative for the production of blood
cells from hematopoietic stem cells.
‘Reversal of aging of bone marrow that produces hematopoietic stem cells will provide younger blood cells with more vitality.’
Dr. Hartmut Geiger said
that the studies conducted showed that the niche where the hematopoietic stem
cells are formed lacks the osteopontin with advancement in age but a
restoration of the level of these proteins showed that the blood cells produced
were younger. The lead author of the study further claimed that the study aided
in pointing towards better forms of therapy for poor immunity and could be used
to develop potential therapy for blood cancer. The study, though conducted on
mice, indicates a possible new line of research.
Bone Marrow Aging
The research team was
involved in numerous experiments to identify a method to determine blood cell
development as well as the vitality of the cells that were present in the
microenvironment of the bone marrow. One of the experiments that were conducted
involved the development of the endosteum stroma cells that give rise to a thin
layer of connective tissue present on the interior side of the bones. The
levels of proteins that were associated with specific cells in the bone marrow,
like osteopontin, were monitored to understand the aging of the bone marrow.
The findings of these
- Older mice
exhibited lowered osteoblasts and other stroma cell production in the
- There were lowered
osteopontin levels in the bone marrow also among older mice, which was
displayed by reduction in the function as well as the vigor of
hematopoietic stem cells.
Setting Right The
Aging of Bone Marrow
The research team
modified the previous studies and conducted further studies on
bone marrow cells from 19-21 months (older) mice into 8 to 10 weeks
- The mice were
treated with a recombinant variant of the osteopontin protein
The experiment that
the bone marrow
from older mice to the younger mice resulted in
- The cells of the younger mice to behave in a more
- There were a
fewer number of hematopoietic stem cells which had the ability to
transform into various types of blood cells.
- The blood cell
types that were predominantly formed were T and B cells while the
production of myeloid cells was low.
The experiment that involved treating the hematopoietic stem
cells with osteopontin
- Younger cells
that showed the potential to develop into various types of blood cells.
- Reduced Cdc42
signaling, a protein that was shown to induce aging of the hematopoietic
The levels of the
protein Osteopontin were not only found to be low in the section of the bone
marrow where hematopoietic cells were formed, but were also detected in the
aging blood. The study has prompted the scientists into studying if osteopontin
replacement therapy could be used to reverse the signs of aging in the
hematopoietic stem cells.
Between Aging Hematopoietic Stem Cells (HSC) and Young HSC Cells
In a study conducted by
Morrison and colleagues titled "The aging of hematopoietic stem cells." And
published in the journal Nature Medicine
the purified hematopoietic stem
cells (HSCs) which were extracted from the bone marrow of old mice were
compared with the hematopoietic stem cells mice that were young. The study
hematopoietic stem cells in the mice, both young and old, were found to be
was more frequency of hematopoietic stem cells in older mice than in young
mice- 5 times more.
- Life Cycle of the Cell - The hematopoietic stem cells from
older mice were from M/S/G2 phases of the cell cycle, but the
hematopoietic stem cells from young mice were rarely found in these
There was a marked
difference in the functioning of the hematopoietic stem cells as they grew
older along with the age of the animal. The current study that identified a
potential means of therapy or rejuvenating techniques which could reverse aging
will aid in increasing host immune defenses as well as better control mechanism
- Novella Guidi, Mehmet Sacma, Ludger Ständker, Karin Soller, Gina Marka, Karina Eiwen, Johannes M Weiss, Frank Kirchhoff, Tanja Weil, Jose A Cancelas, Maria Carolina Florian, Hartmut Geiger. Osteopontin attenuates aging-associated phenotypes of hematopoietic stem cells. EMBO, 2017 DOI: 10.15252/embj.201694969
- The aging of hematopoietic stem cells - (https:www.ncbi.nlm.nih.gov/pubmed/8782459)