Our Musculoskeletal Research laboratory use human stem cells to grow skeletal muscle to help us understand muscle development, model inherited diseases, and test new therapies for the treatment of rare muscle diseases.
Induced pluripotent stem cells (iPSCs) provide an exciting tool for the analysis of human tissues in vitro. The ability to differentiate these cells into any tissue type of the body make them particularly attractive for improving our understanding of both basic biology and disease mechanism. Our group focuses on using human iPSCs to generate skeletal muscle to help us understand muscle development, model inherited diseases, and test new therapies for the treatment of rare muscle diseases.
Until recently the generation of functional skeletal muscle from human iPSCs had not been achieved. In February, Roa et al., 2018 published the first protocol that generated skeletal muscle derived from iPSCs that was also functional (generated force when contracted). This method utilises temporary overexpression of Pax7 (a key muscle transcription factor) in human iPSCs, to generate skeletal muscle in both 2- and 3-dimensional culture conditions. The progenitors readily differentiate into spontaneously contracting multinucleated myotubes and contained a pool of satellite-like cells (key skeletal muscle cells that are needed for self-renewal) that endogenously expressing Pax7, Myod and other muscle markers in vitro. Under 3D culture conditions, the hiPSCs formed functional skeletal muscle tissue that generated force in response to electrical stimulation.
Using a modified approach that does not required Pax7 overexpression we have generated skeletal muscle progenitors from healthy human iPSC lines. These progenitors were purified by FACS and show MyoD, Pax7/Ki67 and α-actinin expression. We are able to cryopreserve these cells and, in 2D culture conditions, generate fused myoblasts. This is the first step towards our ultimate aim of establishing iPSC derived skeletal muscle cultures from patients with rare and debilitating muscle diseases. Developing these techniques will allow us to provide human skeletal muscle tissue generated in vitro for disease modelling and mechanistic studies as well as testing novel therapeutics for the treatment of rare skeletal muscle conditions in the future.
Optimize culture conditions and reduce the time required to generate myogenic progenitors.
Current culture conditions require upwards for 60 days to generate muscle progenitors and form myotubes in 2D conditions. Reducing this culture time will reduce costs, improve efficiency and increase our ability to assess novel genes that are thought to cause inherited muscle diseases.
Generate muscle progenitors from patients affected by inherited muscle diseases to model disease and test novel therapeutic agents.
In vitro modeling of human inherited muscle disorders like congenital myopathies and dystrophies provides a useful tool to assess the effect of these conditions in a dish. We will also use known and novel therapeutic agents to test their efficacy for use in a patient specific model.
Establish 3D culture conditions using iPSC derived skeletal muscle progenitors to improve myotube formation and assess function in vitro.
Current 2 dimensional (2D) culture conditions provide a useful tool to assess aspects of muscle development and growth, protein localisation and expression. However 3D culture systems will enable us to assess a functional muscle unit that better models muscle bundles which are similar to that seen in vivo. Systems have been established using primary myoblasts and cardiac tissue which we will modify to suit skeletal muscle derived from both healthy and patient derived iPSC lines.
Lamandé SR and Bateman JF. (2018) Collagen VI disorders: Insights on form and function in the extracellular matrix and beyond. Matrix Biol. 71-72:348-367.
Garton FC, Houweling PJ ...Gregorevic P, Head SI, Seto JT, and North KN. (2018) The Effect of ACTN3 Gene Doping on Skeletal Muscle Performance. Am J Hum Genet. 102(5):845-857.
Kiriaev L, Kueh S, Morley JW, North KN, Houweling PJ, Head SI. (2018) Branched fibers from old fast-twitch dystrophic muscles are the sites of terminal damage in muscular dystrophy. Am J Physiol Cell Physiol. 314(6):C662-C674.
Hogarth MW*, Houweling PJ* ... Head SI, North KN. (2017) Evidence for ACTN3 as a genetic modifier of Duchenne muscular dystrophy. Nat Commun. 8:14143. *Equal first authors.
Kao T, Labonne T ... Farlie P, Cheung M, Lamande SR, Penington AJ, Parish CL, Thomson LH, Rafii A, Elliott DA, Elefanty AG, Stanley EG. (2016) GAPTrap: A Simple Expression System for Pluripotent Stem Cells and Their Derivatives.Stem Cell Reports. 7(3):518-526.
Woodman KG, Coles CA, Lamandé SR, White JD. (2016) Nutraceuticals and Their Potential to Treat Duchenne Muscular Dystrophy: Separating the Credible from the Conjecture. Nutrients. 8(11). pii: E713.
Yuen M, Sandaradura SA ... North KN, Clarke NF. (2014) Leiomodin-3 dysfunction results in thin filament disorganization and nemaline myopathy. J Clin Invest. 124(11):4693-708.
Lamandé SR, North KN. (2014) Activating internal ribosome entry to treat Duchenne muscular dystrophy. Nat Med. 20(9):987-8.