Myotonic dystrophy (DM) is the most common form of muscular dystrophy, and leads to symptoms in all muscle types, in the form of skeletal muscle wasting, cardiac arrhythmias, and gastrointestinal dysfunction. A multi-systemic disease, DM also commonly affects the central nervous, endocrine, and reproductive systems. DM is caused by expanded CTG or CCTG repeats, which are transcribed into RNA, sequestering the Muscleblind- like (MBNL) RNA binding proteins and titrating them away from their normal mRNA targets. CUG repeat expression also leads to hyper-phosphorylation of the CUGBP/ ELAV-like factors (CELFs), resulting in CELF protein elevation. Dysregulation of MBNLs and CELFs causes hundreds of changes to the transcriptome, including many changes in alternative splicing. To date, the full spectrum of transcriptome changes in DM remains uncharacterized, and it is unknown whether MBNL and CELF perturbation can fully account for those changes. Furthermore, the molecular causes of only a few DM symptoms have been discovered. Another cellular process mediated by the MBNL proteins is RNA localization. Subcellular localization of RNA is important for numerous cellular and physiological processes, including cell motility, embryonic patterning, and synaptic function. However, our understanding of RNA localization remains restricted to a small subset of transcripts, and we lack a molecular parts list for how RNA localization is achieved. Identification of these players will reveal the extent to which RNA mis-localization contributes to pathology in DM and other diseases. Therefore, we will systematically characterize transcriptome changes in DM and assess the extent to which MBNL and CELF per- turbation can explain these changes in DM transcriptomes (Aim 1). We will define a parts list for RNA localization, including cis- and trans- elements, and elucidate how these players control subcellular distribution of RNAs (Aim 2). We will study how changes in all steps of gene expression, including splicing, RNA localization, and translation, may be linked to DM phenotypes, and develop therapeutic approaches to correct these changes (Aim 3). Together, completion of this work will further our understanding of the molecular changes in DM, a paradigm for diseases of RNA toxicity, lay the groundwork for better understanding RNA localization, and help connect these molecular events to physiology.

Public Health Relevance

DM is the most common form of muscular dystrophy, and is a paradigm for a class of diseases caused by RNA toxicity. Understanding molecular changes in DM and linking them to phenotypes will help us understand how pathologies in DM and other diseases arise, and how they can be treated.

Agency
National Institute of Health (NIH)
Institute
Office of The Director, National Institutes of Health (OD)
Type
Early Independence Award (DP5)
Project #
5DP5OD017865-05
Application #
9348427
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Basavappa, Ravi
Project Start
2015-09-01
Project End
2019-08-31
Budget Start
2017-09-01
Budget End
2019-08-31
Support Year
5
Fiscal Year
2017
Total Cost
Indirect Cost
Name
University of Florida
Department
Genetics
Type
Schools of Medicine
DUNS #
969663814
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Yum, Kevin; Wang, Eric T; Kalsotra, Auinash (2017) Myotonic dystrophy: disease repeat range, penetrance, age of onset, and relationship between repeat size and phenotypes. Curr Opin Genet Dev 44:30-37
Dahlman, James E; Kauffman, Kevin J; Xing, Yiping et al. (2017) Barcoded nanoparticles for high throughput in vivo discovery of targeted therapeutics. Proc Natl Acad Sci U S A 114:2060-2065
Pinto, Belinda S; Saxena, Tanvi; Oliveira, Ruan et al. (2017) Impeding Transcription of Expanded Microsatellite Repeats by Deactivated Cas9. Mol Cell 68:479-490.e5
Thornton, Charles A; Wang, Eric; Carrell, Ellie M (2017) Myotonic dystrophy: approach to therapy. Curr Opin Genet Dev 44:135-140
Gudde, Anke E E G; van Heeringen, Simon J; de Oude, Amanda I et al. (2017) Antisense transcription of the myotonic dystrophy locus yields low-abundant RNAs with and without (CAG)n repeat. RNA Biol 14:1374-1388
Thomas, James D; Sznajder, ?ukasz J; Bardhi, Olgert et al. (2017) Disrupted prenatal RNA processing and myogenesis in congenital myotonic dystrophy. Genes Dev 31:1122-1133
Zhang, Fan; Bodycombe, Nicole E; Haskell, Keith M et al. (2017) A flow cytometry-based screen identifies MBNL1 modulators that rescue splicing defects in myotonic dystrophy type I. Hum Mol Genet 26:3056-3068
Freyermuth, Fernande; Rau, Frédérique; Kokunai, Yosuke et al. (2016) Splicing misregulation of SCN5A contributes to cardiac-conduction delay and heart arrhythmia in myotonic dystrophy. Nat Commun 7:11067
Wagner, Stacey D; Struck, Adam J; Gupta, Riti et al. (2016) Dose-Dependent Regulation of Alternative Splicing by MBNL Proteins Reveals Biomarkers for Myotonic Dystrophy. PLoS Genet 12:e1006316
Oddo, Julia C; Saxena, Tanvi; McConnell, Ona L et al. (2016) Conservation of context-dependent splicing activity in distant Muscleblind homologs. Nucleic Acids Res 44:8352-62

Showing the most recent 10 out of 17 publications