Roe, Anne

Anne is in the Cell and Developmental Biology home area of the MBIDP and joined the CMB training program in 2020. She received a B.S. in Biochemistry from Northeastern University and a M.S. in Medical Physiology from Case Western Reserve University.

Mentor: Dr. April Pyle

Research project:

An outstanding issue in stem cell-based therapies is that current directed differentiation protocols of human pluripotent stem cells (hPSCs) into muscle generate immature embryonic myocytes and skeletal muscle progenitor cells (SMPCs). These immature SMPCs lack the ability to self-renew and to remain quiescent in vitro; furthermore, immature SMPCs do not have the ability to regenerate damaged muscle. In the adult, SMPCs mature to become satellite cells (SCs), which are capable of self-renewal, maintaining quiescence and regeneration. The barrier for maturing hPSC- derived SMPCs to SCs in vitro is the lack of an appropriate SC niche. To recreate the SC niche found in vivo, my project is to design a 3D organoid system for muscle development from hPSCs. The Pyle lab currently has a 2D directed differentiation protocol that I am adapting to develop 3D muscle organoids. I will then compare the new 3D system to the 2D system through IF staining, qPCR analysis and single nuclei RNA sequencing, looking at known maturation markers of the myotubes and SCs.

A key feature in muscle development is innervation by lower motor neurons (LMNs) that derive from the lateral spinal cord. Innervation of muscle, and thus the formation of neuromuscular junctions (NMJs), occurs during the transition from the embryonic to the fetal stage of development. The nuclei within myofibers closest to NMJs remodel to express specific genetics subsets and the loss of NMJs causes muscle atrophy, progresses neuromuscular diseases and accelerates aging. While it is known that NMJs are important for the maintenance of adult skeletal muscle, its role in maturation of SMPCs to SCs during development is unclear. To test the role of innervation and NMJs in the development and maturation of myocytes and SMPCs, I will add LMNs to the 3D muscle organoid system. Then using the same techniques as above, I will compare the maturation status of the myotubes and SCs in the 3D muscle organoids with and without LMNs. Furthermore, successful creation of functioning NMJs in vitro opens up the door to model rare NMJ diseases.