Zebrafish and Cellular Models of SELENON-Related Myopathy Exhibit Early Growth and Metabolic Abnormalities


Translational Research

Poster Number: 169


Pamela Barraza-Flores, PhD, Boston Children's Hospital/ Harvard Medical School, Behzad Moghadaszadeh, Children's Hospital/ Harvard Medical School, Emily Troiano, Boston Children's Hospital, Benton Mitchell, Boston Children's Hospital, Alan Beggs, PhD, Boston Children's Hospital / Harvard Medical School

SELENON-Related Myopathy (SELENON-RM) is a rare genetic disease caused by recessive mutations of the SELENON gene. It is characterized by spinal muscle weakness and the development of rigid spine from a young age. The most common histopathological feature in SELENON-RM patients is the presence of minicores–concentrated areas of mitochondrial depletion in skeletal muscle biopsies. Additionally, insulin-resistance as well as altered body mass index (BMI) have been associated with SELENON-RM in patients. The SELENON gene encodes selenoprotein N, a sarcoplasmic reticulum membrane protein with reducing catalytic activity. Selenoprotein N has been shown to enhance the activity of SERCA channels in the oxidizing environment of the sarcoplasmic reticulum and to participate in mitochondrial function in muscle cells. However, the molecular mechanism(s) by which selenoprotein N deficiency causes SELENON-RM are still undetermined. A particular challenge has been the lack of cellular or animal models that exhibit readily assayable disease-related abnormalities. In this project, we aim to identify cellular and animal models suited for high throughput drug screening while elucidating the molecular mechanism of the disease. To do so, we tested selenoprotein N deficient cells and zebrafish selenon-null models. Our results showed that using measures of metabolism, C2C12 cells and primary cells isolated from mice both deficient in selenoprotein N were metabolically impaired. We also tested several phenotyping outcomes in zebrafish models from development to adulthood. These results showed muscle weakness during development as well as reduced growth during the larval stage. Together, these data establish the potential of selenoprotein N deficient cells and zebrafish for the development of drug screening for therapeutic targets for SELENON-RM.