Poster Presentation 41st Lorne Genome Conference 2020

Global Analysis of Gene Expression in Differentiating Human Primary Muscle Cells (#264)

Akriti Varshney 1 2 , Sarah Alexander 3 , Paul Harrison 2 , Angavai Swaminathan 2 , Severine Lamon 3 , Bernhard Dichtl 1 , Traude Beilharz 2
  1. CCMB, Deakin University, Melbourne, VIC, Australia
  2. BDI, Monash University, Melbourne, VIC, Australia
  3. School of Exercise & Nut. Sci., Deakin University, Melbourne, VIC, Australia

Myogenesis is an intricate process and the molecular networks regulating it have not been fully determined. The current understanding is that myogenic progenitor cells become committed myoblasts when they start expressing Myf5 or MyoD. These myoblasts then begin expressing myogenin (MyoG) and myosin heavy chain (MHC) to form nascent myotubes. Subsequently, multiple myotubes fuse, the sarcomeres align, and the cells are able to contract, thereby completing the terminal differentiation process [1]. Most of our current understanding about muscle cell differentiation is derived from immortalised muscle cell lines and there is no comprehensive NGS analysis available for developing human primary myocytes. In order to address this limitation, this study analysed primary myocytes, which were obtained from human participants’ thigh muscle biopsies. Primary cells underwent a seven-day differentiation time course and total RNA was extracted at six distinct time points. Subsequently, RNA molecules with a poly(A)-tail were reverse transcribed into cDNA, which was then used as an input for 3’-end focused sequencing. Downstream bioinformatic analysis revealed that observed changes in gene expression were similar to the C2C12 mouse cell line, with an upregulation of muscle specific genes such as MYOD1 and MYOG [2]. Overall, 7552 genes were differentially expressed (FDR < 0.05), the majority being protein coding genes, followed by processed pseudogenes and non-coding genes. However, interestingly, alternative polyadenylation, which plays an important role in gene regulation of C2C12 mouse immortalized cells, did not appear to play a significant role in human myogenesis [3]. Since primary cells are physiologically closer to human tissue with fewer metabolic differences compared to immortalised cell lines, the current study will enhance our understanding of the relevant molecular underpinnings of gene expression regulation in developing myocytes. These insights may help to improve outcomes for individuals suffering from debilitating muscle disease.

  1. Jiwlawat, N, Lynch, E, Jeffrey, J, Van Dyke, JM & Suzuki, M, 2018. Current progress and challenges for skeletal muscle differentiation from human pluripotent stem cells using transgene-free approaches. Stem Cells International, 2018.
  2. Abdelmoez, AM, Sardón Puig, L, Smith, JA, Gabriel, BM, Savikj, M, Dollet, L, Chibalin, AV, Krook, A, Zierath, JR and Pillon, NJ, 2019. Comparative profiling of skeletal muscle models reveals heterogeneity of transcriptome and metabolism. American Journal of Physiology-Cell Physiology.
  3. Wang, R, Zheng, D, Wei, L, Ding, Q and Tian, B, 2019. Regulation of intronic polyadenylation by PCF11 impacts mRNA expression of long genes. Cell reports.