Project Details
Projekt
High resolution mapping of genomic elements relevant for muscle development as potential mutational hot-spots in patients with congenital myopathy and congenital muscle dystrophy
Subject Area
Human Genetics
Developmental Neurobiology
Pediatric and Adolescent Medicine
Developmental Neurobiology
Pediatric and Adolescent Medicine
Term
since 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 400728090
Congenital myopathies (CM) and congenital muscular dystrophies (CMD) are a genetically heterogeneous group of diseases characterized by impaired muscle development. They are often caused by mutations in genes encoding proteins that form the functional scaffold of muscles. However, whole-exome sequencing only identifies the underlying mutations in a maximum of 50% of cases. To become able to solve the unexplained cases, we would like to perform whole genome sequencing that includes the non-coding genome. To interpret the large number of non-coding modifications and structural variants located there, we set out to map the regulatory network for human muscle development at high resolution. Here, we aim to identify the precise binding sites of myogenic transcription factors (TFs) and the locations of histone modifications. For this purpose, we use muscle fibers or neuromuscular organoids grown from induced human pluripotent stem cells. These express the characteristic early myogenic markers and exhibit mRNA expression profiles of early fetal muscle development. To bridge the gap between early and later muscle development, we now plan to study 3D neuromuscular organoids. In these organoids, spinal cord and skeletal muscle cells are generated simultaneously to form functional neuromuscular units, which represent human development much better than isolated 2D cultures of muscle fibers. Another advantage is that the neuromuscular organoids can be maintained in culture for months. The muscle fibers mature over time, increase in size, and show peripheral localization of their myonuclei. In a second FOR funding period, we will focus on screening these neuromuscular organoids for binding sites of the muscle-related transcription factors PAX3, PAX7, MYOD, MYF6, MYOD, and MYOG. For this purpose, we use combined single nuclear RNA and ATAC sequencing as well as the CUT&TAG technology, which we have already successfully used in our laboratory during the first funding period. By combining 2D- and 3D-methods, we will obtain epigenetic data on muscle development seamlessly from muscle progenitor cells to the final signature of the newborn muscle. All these epigenetically modifiable loci together will then be considered as potential candidate regions for mutation screening in patients with CM and CMD.
DFG Programme
Research Units
