Pena Lab @ CHEO-RI / uOttawa
Animal models for rare pediatric diseases:
I am exploring the use of Zebrafish as a model for Rare Disease research, focusing on rare neurometabolic disorders. We have just recently published the first zebrafish model for Pyridoxine-Dependent Epilepsy (PDE), developed using the CRISPR/Cas9 technology [1]. See on the right side some examples of the normal behaviour of zebrafish larvae and the convulsive seizures displayed by the aldh7a1-deficient zebrafish larvae (videos from our Genetics paper). We have also co-led the description of a cohort of PLPBP-deficiency patients together with the development of a its first zebrafish model by CRISPR/Cas9, another severe form of PDE characterized by neonatal epilepsy, published at Brain.
Zebrafish larvae are very small and can be easily adapted for high-throughput drug testings, fitting in multiwell plates. Seizures can be induced by drug treatments or spontaneously by introduction of mutations in key genes similarly to what is seen in humans born with mutations leading to epileptic diseases. Our lab will focus on generating novel models of rare pediatric neurometabolic diseases in zebrafish by CRISPR/Cas9 and introducing gene therapy and drug discovery tools to investigate potential rescues in a systemic or cell-type dependent manner.
Novel organellar biology isolation techniques and cell-type specific mitochondrial profiling in disease
Most diseases we are interested have a mitochondrial dysfunction component, in which a mutated gene product either has a role on mitochondrial biology or is itself a mitochondrially-localized protein. During my postdoctoral work at MIT I focused on developing technologies to isolate (with high purity) mitochondria of specific cell types in vivo (in mice), a method that will allow us to address many longstanding questions in disease-related biochemical research (manuscript under preparation). Mitochondria in particular are often found to be dysfunctional in neurological diseases, from neurodegeneration to rare neurometabolic diseases such as PDE. We hope to expand this technology to target relevant cell types in vivo for the study of the rare neurometabolic diseases which are the focus of our lab: Pyridoxine-Dependent Epilepsy (PDE), Glutaric Acidemia type I (GA1) and Congenital Sideroblastic Anemias (CSA)..
Using functional genomics to investigate vitamin B pathways and mechanisms with relevance to rare genetic diseases
During my training at MIT, I performed genome-wide CRISPR screens in cells grown in media rich for or depleted in vitamin B6. I identified numerous genes and pathways essential for growth in limited quantities of B6. Given the importance of vitamin B6 as a cofactor for the synthesis of neurotransmitters, as well as the synthesis and assembly of heme and iron-sulfur clusters in mitochondria, our findings are relevant to a variety of rare diseases in which these components are depleted. A manuscript describing this research is currently under review and we hope to share here very soon!
We aim to expand our portfolio and develop additional CRISPR-screens for vitamin studies. including in patient-derived cell lines. We hope to use functional genomics to identify positive interactor genes that can rescue disease phenotypes in cell cultures. We also hope to identify synthetic lethal pathways which are uniquely essential in disease models with the hopes to understand what else is dysfunctional in patient cells other than the obvious gene defects. All these novel data will hopefully guide new therapeutic avenues for rare diseases.
