2012 MDF Research Fellows

Micah Bodner, PhD
University of Oregon, Eugene, Oregon, US

Dr. Bodner’s research, “Therapeutic Agents for Myotonic Dystrophy; Defining the Pharmacophore of Pentamidine,” under the guidance of Dr. John Andrew Berglund, Ph.D., at the University of Oregon, will continue the study of a potential therapeutic drug, pentamidine, which was recently identified by the University of Oregon. Pentamidine is a promising lead compound for treatment of DM. Pentamidine and compounds like it have been used to reverse symptoms of DM in cell and mouse models of the disease and even alleviate myotonia in mice. However, some obstacles must be overcome before a pentamidine-based compound can be used clinically. The obstacles include: a lack of evidence for how pentamidine elicits the therapeutic effect; lack of oral availability; lack of central nervous system (CNS) activity; and toxicity. The experiments proposed in Dr. Bodner’s research plan are designed to increase understanding of how pentamidine functions and how to manipulate it in order to make a useful DM therapeutic that is orally available, CNS active and non-toxic. The information gained from these experiments will also be used to design other compounds similar to pentamidine to better understand what portions of the compound promote binding to the RNA fragment. These compounds will then be used in DM cell and mouse model testing to understand how they perform in tests and whether they are tolerated by the cells and animals.

Nicholas Johnson, MD
University of Rochester Medical Center, Rochester, New York, US

Dr. Johnson’s research, “Characterization of Symptoms and Development of a Disease Specific Instrument for Congenital and Juvenile Myotonic Dystrophy,” under the guidance of Dr. Chad Heatwole, M.D. at the University of Rochester Medical Center in Rochester, New York, will study the severe congenital and juvenile onset forms of myotonic dystrophy. Currently, there is very little information about the most critical symptoms associated with these forms of the disease. There are anecdotal reports that indicate that the issues important to patients with early onset myotonic dystrophy are different from those experienced by adult onset myotonic dystrophy patients. In addition, to date no significant research has been conducted to study the impacts of promising adult-onset DM therapies in congenital and juvenile-onset populations. This project will collect survey data from children and their parents describing and prioritizing the effects of the disease on the children’s cognitive, physical, and emotional health. This data will be used to create an instrument measuring quality of life for this population, both with respect to the impact of key DM issues and of current adult-onset treatments on key issues affecting congenital and juvenile-onset DM patients and their family members.

Zhihua (Tina) Gao, PhD
Baylor College of Medicine, Houston, Texas, US

Dr. Gao’s research, “Development of Therapeutic Approaches to Silence CUG Expansion RNA in Myotonic Dystrophy Mouse Models Using Recombinant Adeno-associated Virus,” under the guidance of Dr. Thomas Cooper, M.D., at Baylor College of Medicine in Houston, Texas, will use a virus that has been modified for therapies of other muscular dystrophies to carry elements that can remove the toxic RNA in myotonic dystrophy mouse models. The effective therapeutic approach developed in the mouse model holds a potential for future clinical trials in DM1 patients. Myotonic dystrophy is caused by an unusual genetic mutation in which a small DNA segment of the mutated gene is repeated hundreds of times. DNA, in the form of chromosomes, is in the nucleus of a cell. When there is a need, DNA is copied into RNA. RNA then moves from the nucleus to the cytoplasm of the cell to deliver the genetic message. In myotonic dystrophy, the mutated gene is copied into RNA, but the RNA is trapped in the nucleus because of the repeated segments. The RNA then builds up in the nucleus and creates problems that disrupt the functions of many other genes. The RNA with repeated segments therefore becomes very toxic.

By forcing the expression of the mutated gene with hundreds of repeated segments in mouse skeletal muscle and heart, researchers have mimicked the DM1 (type 1) disease in mice. The goal of Dr. Gao’s proposal is to develop a recombinant adeno-associated virus (rAAV) vector-based strategy to clear away the toxic RNA in the DM1 mice. Dr. Gao’s sponsoring facility, the lab of Dr. Thomas Cooper, M.D., at Baylor College of Medicine, recently established a collaboration with Dr. Reed Clark, Ph.D., at the Center for Gene Therapy at Nationwide Children's Hospital/Ohio State University in Columbus, Ohio, led by Dr. Jerry R. Mendell, M.D.  A major effort of the Center is to develop rAAV vectors for therapeutic approaches for DMD, LGMD, FSHD, and DM1. Once established and optimized in mice, Dr. Gao and her team will work with collaborators to develop rAAV as a therapeutic approach for human trials. This strategy will be developed for DM1, the more common form of DM, but can also be used for DM2 (type 2).

Eric Wang, PhD
Harvard-MIT Health Sciences and Technology, Cambridge, Massachusetts, US

Dr. Wang’s research, “Identification of RNA Processing Changes in the Myotonic Dystrophy Transcriptome,” under the guidance of Dr. Christopher Burge, Ph.D., and Dr. David E. Housman, Ph.D., at Harvard-MIT Division of Health Sciences and Technology (HST), Cambridge, Massachusetts, will help to improve the understanding of DM pathogenesis. Various events associated with the expanded RNA repeat sequences that cause DM have been well established, but there are other hypotheses for what happens during DM pathogenesis. To date there have been no studies globally surveying all the RNA changes in DM, making it challenging for the DM research community to conclude whether it has identified all the major cellular pathways disturbed in DM. Identifying all these changes will provide a research road map, as well as specific readouts that can be used for diagnostics and therapeutic studies. Using a type of high throughput sequencing technology that has been recently developed, Dr. Wang proposes to identify RNA level changes that occur in various mouse models of DM, assess the extent to which current models for DM pathogenesis can explain what is happening in human DM, and develop potential therapeutic interventions using the insights gained from these analyses. The successful completion of these studies will augment the DM community’s understanding of DM pathogenesis, and provide a set of biomarkers that can be used immediately for diagnostics and therapeutic development.