Tuesday, 5 March 2013

New stem cell approach for the treatment of Duchenne Muscular Dystrophy

In a new study, researchers from the University of Minnesota's Lillehei Heart Institute (UMLHI) used induced pluripotent stem cells (iPSCs) and a novel genetic repair method to create skeletal stem cells, which in turn were used to partially restore muscle function in a Duchenne Muscular Dystrophy (DMD) mouse model.

During the study, the researchers combined three different technologies to create a stem cell-based therapy.

First, they took skin cells from mice suffering from a severe case of muscular dystrophy and transformed them into iPSCs. Similarly to the originating cells, the iPSCs also carried mutations in the dystrophin and utrophin genes.

The researchers then used a genetic correction tool, also developed by UMLHI researchers, called the "Sleeping Beauty Transposon". The Sleeping Beauty is a synthetic DNA transposon (DNA sequence that can change its position within the genome) that was developed to introduce precisely defined DNA sequences into the chromosomes of vertebrate animals (humans included). With the help of this tool the scientists introduced a gene called "micro-utrophin" to the previously created iPSCs.

Similarly to dystrophin, micro-utrophin protein also supports muscle fibre growth. However, the researchers say that that there is a major difference between the two of them. Since dystrophin is absent in DMD patients, its presence alarms the immune system which in turn may start a devastating immune response. However, utrophin is present in DMD patients and as a result the newly introduced micro-utrophin can begin the process of building new muscle tissue without starting an immune response.

Computer generated picture of dystrophin
Computer generated image of Dystrophin


Finally the researchers employed a method, developed by Rita Perlingeiro, which converts the aforementioned iPSCs into mesenchymal stem cells (MSCs), the stem cells that develop into muscle, bone and cartilage tissue. The method involves the use of a protein called Pax3 which both induces iPSCs towards becoming MSCs and also allows them to grow exponentially. The newly derived MSCs were then transplanted back to the originating mice.


Picture of a mesenchymal stem cell
A mesenchymal stem cell

According to the study's findings, the new stem cells were not rejected and generated new muscle tissue that functioned properly. The researchers say that their study is proof that stem cells combined with genetic correction methods have the capacity to treat muscular dystrophy conditions, and consider it to be "a major step" in the development of autologous stem cell treatments for such conditions, including DMD.

Antonio Filareto, lead author of the study, said:

"Utilising corrected induced pluripotent stem cells to target this specific genetic disease proved effective in restoring function, These are very exciting times for research on muscular dystrophy therapies."

Perlingeiro, senior author, said:

 "Developing methods to genetically repair muscular dystrophy in human cells, and demonstrating efficacy of muscle derived from these cells are critical near-term milestones, both for the field and for our laboratory. Testing in animal models is essential to developing effective technologies, but we remained focused on bringing these technologies into use in human cells and setting the stage for trials in human patients."

The researchers hope that their study will eventually lead to human clinical trials that will examine the safety and efficacy of the same approach in patients with Duchenne Muscular Dystrophy and other muscular dystrophy conditions.



Duchenne muscular dystrophy,  is a rapidly progressive form of muscular dystrophy (disorders that involve loss of muscle tissue, which progressively get worse) occurring primarily in boys. It is caused by a mutation in a gene, called the DMD.

Video about the condition




Reference
Filareto, A., Parker, S., Darabi, R., Borges, L., Iacovino, M., Schaaf, T., Mayerhofer, T., Chamberlain, J., Ervasti, J., McIvor, R., Kyba, M., & Perlingeiro, R. (2013). An ex vivo gene therapy approach to treat muscular dystrophy using inducible pluripotent stem cells Nature Communications, 4 DOI: 10.1038/ncomms2550

4 comments:

  1. I hope, we'll get success as soon as possible! I'm eagerly waiting to get it done in successfully in human being...

    ReplyDelete
  2. Hello,

    I am Anil nakrani

    I have a patient of dmd i am waiting this researchers.

    thanks!

    ReplyDelete
  3. We are all awaiting to treat this. KIndly update the results in human trails asap.
    Saurabh, India

    ReplyDelete
  4. Good afternoon. Please tell me your answer when we have this treatment for DMD.

    Barbu Geta Romania
    June 30, 2013

    ReplyDelete

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