Muscle Stem Cell Transplant Boosts Diseased Muscle Function And Replenishes Stem

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Muscle Stem Cell Transplant Boosts Diseased Muscle Function And

Replenishes Stem Cell Pool

http://www.medicalnewstoday.com/articles/114620.php

Researchers at the Joslin Diabetes Center have demonstrated for the

first time that transplanted muscle stem cells can both improve

muscle function in animals with a form of muscular dystrophy and

replenish the stem cell population for use in the repair of future

muscle injuries.

" I'm very excited about this, " said lead author Amy J. Wagers, Ph.D.,

Principal Investigator in the Joslin Section on Developmental and

Stem Cell Biology, principal faculty member at the Harvard Stem Cell

Institute and Assistant Professor of Stem Cell and Regenerative

Biology at Harvard University. " This study indicates the presence of

renewing muscle stem cells in adult skeletal muscle and demonstrates

the potential benefit of stem cell therapy for the treatment of

muscle degenerative diseases such as muscular dystrophy. "

The study was designed to test the concept that skeletal muscle

precursor cells could function as adult stem cells and that

transplantation of these cells could both repair muscle tissue and

regenerate the stem cell pool in a model of Duchenne muscular

dystrophy, she said. The research is published in the July 11 issue

of Cell.

Duchenne muscular dystrophy is the most common form of the disease

and is characterized by rapidly progressing muscle degeneration. The

disease is caused by a genetic mutation and there is currently no

cure.

The data from this new study demonstrate that regenerative muscle

stem cells can be distinguished from other cells in the muscle by

unique protein markers present on their surfaces. The authors used

these markers to select stem cells from normal adult muscle and

transferred the cells to diseased muscle of mice carrying a mutation

in the same gene affected in human Duchenne muscular dystrophy.

" Once the healthy stem cells were transplanted into the muscles of

the mice with muscular dystrophy, they generated cells that

incorporated into the diseased muscle and substantially improved the

ability of the treated muscles to contract, " said Wagers. " At the

same time, the transplantation of the healthy stem cells replenished

the formerly diseased stem cell pool, providing a reservoir of

healthy stem cells that could be re-activated to repair the muscle

again during a second injury. "

According to the paper, these cells provide an effective source of

immediately available muscle regenerative cells as well as a reserve

pool that can maintain muscle regenerative activity in response to

future challenges.

" This work demonstrates, in concept, that stem cell therapy could be

beneficial for degenerative muscle diseases, " Wagers said.

Wagers also said the study will lead to other studies in the near-

term that will identify pathways that regulate these muscle stem

cells in order to figure out ways to boost the normal regenerative

potential of these cells. These could include drug therapies or

genomic approaches, she said. In the long-term, the idea will be to

replicate these findings in humans.

" This is still very basic science, but I think we're going to be able

to move forward in a lot of directions. It opens up many exciting

avenues, " she said.

The Wagers Lab at Joslin studies both hematopoietic stem cells, which

constantly maintain and can fully regenerate the entire blood system,

as well as skeletal muscle stem cells, involved in skeletal muscle

growth and repair. The work is aimed particularly at defining novel

mechanisms that regulate the migration, expansion, and regenerative

potential of these two distinct adult stem cells.