New protein
that guides and stimulates blood vessel formation identified
Washington: Researchers have identified a protein that is
expressed by human bone marrow stem cells that helps guide and stimulate the
formation of blood vessels.
Their findings, which could help improve the vascularization of
engineered tissues, were reported online on October 12 in the Journal of
Molecular and Cellular Cardiology.
Lead author Dr. Jalees Rehman, associate professor of cardiology
and pharmacology at the UIC College of Medicine, said that some stem cells
actually have multiple jobs, for example, stem cells in the bone marrow
differentiate into bone or cartilage, but also have a secondary role in helping
to support other cells in the bone marrow.
Rehman and his team, who are developing engineered tissues for
use in cardiac patients, observed that certain stem cells in bone marrow,
called mesenchymal stem cells, seemed crucial for organizing other cells into
functional blood vessels.
The researchers demonstrated that when they mixed mesenchymal
stem cells from human bone marrow with the endothelial cells that line blood
vessels, the stem cells elongated to form scaffolds and the endothelial cells
organized around them to form tubes.
Rehman said that without the stem cells, the endothelial cells
just sat there.
When the cell mixtures were implanted into mice, blood vessels
formed, which were able to support the flow of blood.
Researchers tested two different stem cell lines from human bone
marrow. One line supported the formation of blood vessel networks when it was
mixed with endothelial cells, while the other cell line did not.
They analyzed the genetic signature and proteins of the
respective cell lines and found that the vessel-supporting stem cell line
released high levels of a blood vessel guidance molecule - SLIT3. In the
mixture that didn't form blood vessels, the SLIT3 gene was hardly expressed,
Rehman said.
Their findings have been published in the Journal of Molecular
and Cellular Cardiology.
22.10.2013
Circumcised foreskins may provide new baldness
treatment
Melbourne: In a breakthrough, scientists have successfully
grown human hair follicles in the laboratory using circumcised foreskins from
newborns.
The study, conducted by researchers from Columbia
University in New York and Durham University in UK, involved culturing altered
human cells within tissue from the circumcised foreskins of newborns and
grafting the resulting structures on to the backs of mice.
Previous studies have found that adult rodent dermal
papillae, which control hair follicle growth, can be grown in the laboratory,
transplanted into recipient skin and made to trigger new hair follicles and
fibres.
Now, researchers have achieved a similar feat using
laboratory-grown human hair follicle dermal cells to trigger the growth of human
hair, 'Sydney Morning Herald' reported.
Researchers used 3D culture conditions rather than 2D cultures
to restore the hair-inducing properties of human dermal papilla cells when
inserted into human foreskin.
The authors said neonatal foreskin was selected because it
is non-hair bearing tissue, which would challenge the human dermal papillae
that control hair follicle growth "not just to contribute to hair
follicles within the skin, but rather, to fully reprogramme the recipient
epidermis to a follicular fate".
After six weeks of implantation, new hair follicles from
five of seven donors were seen in the implanted skin.
The authors reported in the journal Proceedings of the
National Academy of Sciences that the 3D culture conditions (3D dermal
spheroids) helped partially restore the cells' normal gene expression
signatures and hair-inducing properties.
22.10.2013
A optimist is
one who makes difficulties of his opportunities and an pessimist is one who
makes opportunities of his difficulties
Harry
Truman
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