Poster Session 1 - B23
1Vijay Narasimhan, 2Jane Foster, 1,2Sidney Kennedy, 1,3Xiao-Yan Wen
1Zebrafish Centre for Advanced Drug Discovery & Keenan Research Centre, St. Michael’s Hospital, Toronto, Canada, 2University Health Network, 399 Bathurst Street, Toronto, Canada, 3Department of Medicine & Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 1A8
Background Zebrafish has emerged as a robust vertebrate model for depression studies given the physiological similarity to humans in neurotransmitter systems, neuroanatomical structures, and genetic overlap1. This study applies a Reverse Translation strategy to validate clinically identified MDD biomarkers in zebrafish and generate models and reporter line for mechanistic studies and drug screens. From a Canadian Biomarker Integration Network in Depression Duloxetine patient study, a number of microRNA biomarkers have been identified as antidepressant responders2, including miR-146a, miR-146b and miR-24 that are conserved in zebrafish. In zebrafish, we validated that these miRNAs are duloxetine responsive by real-time PCR. Methods and Results The goal of this study is to generate zebrafish models and reporter lines that mimic genetic changes in MDD patients with easy biological readout for drug screens. Using Tol2 transgenesis, we have generated two zebrafish transgenic lines containing miR-24 target recognition sequence (MIRS) downstream of GFP. The first line contains one miR-24 target recognition sequence and the second line contains ten MIRS. We also generated a control transgenic line expressing GFP without any MIRS sites. The endogenous zebrafish miR-24 will regulate the expression of GFP reporter, which can serve as an efficient readout for drug screens. We were also successful in generating the first generation of the transgenic fish. Conclusion The field of Treatment Resistant Depression (TRD) suffers from a lack of data as well as often poorly designed studies that do not advance our understanding. The use of zebrafish as a preclinical model to test MDD targets would represent a significant advancement in the field. We have successfully generated a transgenic zebrafish that can be used as a tool for screening novel drugs against miR-24. Currently, we are involved in validating the line using morpholino, miRNA mimic and small molecules.