New funding from a partnership of SickKids Hospital and the CIHR Institute for Human Development, Child and Youth Health will support Dr. Annie Ciernia’s (pictured) research into the epigenetic mechanisms driving changes in the brains of kids with a rare form of autism spectrum disorder (ASD) and epilepsy.
The funding, in the form of a New Investigator Grant, will support Dr. Ciernia’s project, titled “The role of BAF53B in regulating neuronal gene expression, synaptic function and autism behaviours across development.” Dr. Ciernia’s study will look at the role of a brain-specific epigenetic regulator with identified mutations in children with a rare genetic form of ASD, and will identify how disruption of this mechanism leads to impaired brain function and ASD-associated behaviours.
The gene, BAF53B, appears to play a role in early neuronal developmental and long-term memory formation in adults. Recently, rare mutations in BAF53B were identified in a handful of Canadian children who have intellectual disability, seizures and behavioural impairments related to ASD. Researchers have yet to fully understand how these specific gene mutations result in impaired cognitive function—ia question Dr. Ciernia aims to answer using mouse models where BAF53B can be conditionally deleted from different types of neurons at different stages of development. The Ciernia lab will then study these mice to identify how loss of BAF53B impacts brain development and if the mice show ASD-like behaviors or seizures.
“This gene is interesting because it is only expressed in neurons, and not in other types of cells in the body,” said Dr. Ciernia. “We want to see if making conditional deletions of the gene will preferentially impact different types of neurons in the developing brain.”
A relationship already exists between ASD and seizure-disorder phenotypes, but researchers don’t yet know enough about what BAF53B does to understand how it is supposed to function in neurotypical brains. In future work Dr. Ciernia and her team will introduce identified human mutations of BAF53B into their mouse models in order to assess how these mutations impact the gene’s function.This work builds on some of Dr. Ciernia’s earlier work, which found that targeted manipulation of BAF53B in adult mice could restore neuroplasticity and memory function.
“The mutation of BAF53B was originally thought to be lethal, as no clinical cases were documented until very recently. The children with these mutations do have severe impairments, and many don’t survive beyond childhood,” said Dr. Ciernia.
Dr. Ciernia, who came to UBC as a Canada Research Chair in Understanding Gene Expression in the Brain in June 2019, has been working with other researchers at the Djavad Mowafaghian Centre for Brain Health (DMCBH) to study glia-neuron integration in ASD and other neurodevelopmental disorders.
Since establishing her lab at DMCBH last summer, her team has grown to include two PhD students, five undergraduate students, and a lab manager; she is currently in the process of recruiting a postdoctoral fellow to work on the BAF53B project. As part of the DMCBH, Dr. Ciernia’s lab aims to develop collaborations across a range of model organisms to better understand how changes in the developing brain can cause disability in young children and, eventually, to establish novel targets for therapeutic intervention.