100
thousand
Estimated
number of follicles
on human scalp
120
million
Estimated
number of rods
in human retina
Engineered cells
sprout new hair
A cell-based approach to
making follicles takes root
mice. After about two weeks, hairs began
to sprout. Under the microscope, the
hair grown from the bioengineered
mouse follicles resembled normal hair,
scientists found. And the mouse follicles
went through the normal cycle of grow-
ing hair, shedding and making new hair.
When researchers injected the region
around the bioengineered follicle with
acetylcholine, a drug that causes mus-
cles to contract, the hairs perked up. This
finding suggests that the transplanted
follicles had integrated with surround-
ing muscle and nerves like normal hair
follicles do.
The researchers were able to ensure
hair didn’t become ingrown or point in
the wrong direction by attaching a nylon
thread to the engineered follicles and
guiding the hair to grow outward.
Applying similar methods to cells collected from the scalps of men with male
By Rebecca Cheung
A hair-raising trick may lead to better
hair transplants. Engineered hair follicles patched into skin can be coaxed
to connect to surrounding tissue and to
grow hair in an organized way, a study
in mice finds.
Unlike current hair transplant methods, which simply move existing hair
follicles from one area of the scalp
to another to cover a bald region, the
approach would spur the creation of new
hair follicles from existing cells.
“It’s exciting because it shows a
cell-based approach for treating hair
loss is maybe feasible,” says George
Cotsarelis, a dermatologist at the University of Pennsylvania in Philadelphia.
The results also mark a step forward
in efforts to regenerate organs such as
salivary glands that form in a process
similar to hair early in their development, says study coauthor Takashi
Tsuji of Tokyo University of Science in
Chiba, Japan. Tsuji and his colleagues
describe the findings in the April 17
Nature Communications.
Hair follicles develop when two
different types of cells — epithelial and
mesenchymal cells — interact with each
other. Epithelial cells grow very quickly
and shed, while mesenchymal cells
direct epithelial cells to make a follicle.
Previously, Tsuji and colleagues had
bioengineered follicles and hair shafts
in the lab using epithelial and mesenchymal cells from mouse embryos.
Until now, it was unclear whether these
organized clusters of cells would make
normal hair if inserted into mouse skin.
In the new work, the team transplanted a group of the engineered follicles into the skin on the backs of hairless
Bioengineered follicles can grow tufts
of hair on the scalps of normally hair-
less mice. The technique may improve
treatments for male-pattern baldness.
pattern baldness, researchers created
individual follicles that grew hair once
transplanted into hairless mice.
Still, Cotsarelis says that these findings do not show whether the number
of human hair follicles can be amplified,
so that more hair is produced.
Transplants help night-blind mice
Injecting light-gathering rod cells restores vision in rodents
By Tina Hesman Saey
The farmer’s wife in the nursery rhyme
“Three Blind Mice” may need a different
hunting strategy. Thanks to cell transplants, some formerly night-blind mice
can see in the dark, perhaps even well
enough to evade a swinging carving knife.
Light-gathering nerve cells called rods
injected into the retinas of night-blind
mice integrated into the brain’s visual
system and restored sight, Robin Ali of
the University College London Institute of Ophthalmology and colleagues
report online April 18 in Nature. The
finding gives hope that cell transplants
may reverse damage to the brain and
eyes caused by degenerative diseases
and help heal spinal cord injuries.
Other researchers have tried unsuc-
cessfully to repair damaged retinas with
stem cell transplants, says Christian
Schmeer, a neurologist at the University
Hospital Jena in Germany. The new study
is the first to demonstrate that trans-
planted nerve cells can restore function.
www.sciencenews.org
May 19, 2012 | SCIENCE NEWS | 13
