Several mental disorders are closely associated with defects during neuronal development in early life. Abnormalities in neuronal differentiation and synaptogenesis may contribute to fragile X syndrome, Rett syndrome, autism, and other mental disorders. Post-transcriptional regulation by microRNAs (miRNAs) has emerged as an important mechanism for controlling gene expression in animal development;however, the exact functions of miRNAs in neuronal differentiation and function are poorly understood. Moreover, the genes and pathways regulated by miRNAs in the nervous system are largely unknown. miRNAs are 21-23-nt endogenous noncoding RNAs processed from 70-80-nt precursors that are mostly transcribed by RNA polymerase II and form stem-loop structures. miRNAs regulate gene expression by repressing translation or cleaving messenger RNAs. Estimated to comprise 1-5% of animal genes, miRNAs are thought to regulate the expression of a large number of target genes in developmental processes. A few miRNAs are specifically expressed in mammalian brains, suggesting unique regulatory roles in neuronal development and function. Indeed, miRNAs have been implicated in left/right neuronal asymmetry in Caenorhabditis elegans, photoreceptor formation and early neurogenesis in Drosophila, brain morphogenesis and neurogenesis in zebrafish, and neuronal differentiation in mammals. However, loss-of-function approaches have not been widely used to study the roles of miRNAs in the nervous system or other development processes. In Drosophila, for instance, only a few miRNAs have been studied in vivo using loss-of-function approaches, including miR-9a whose function in the specification of sensory organ precursors was reported by our laboratory. In this application, we propose to use in vivo genetic and molecular techniques and genomic approaches to elucidate the role of translational control by miRNAs in neuronal development in Drosophila. We will also investigate the underlying molecular mechanisms and validate and characterize one or two bona fide miRNA targets. The proposed studies will provide important novel insights into the neuronal functions of the miRNA pathway in intact animal models and will further our understanding of human mental disorders. Our findings may also help develop new avenues for therapeutic interventions for these devastating illnesses.
In this proposal, we will investigate the roles of some tiny RNAs, called microRNAs, in the development of the nervous system. We will use fruitfly as our primary model system for all the proposed studies.
|Yuva-Aydemir, Yeliz; Xu, Xia-Lian; Aydemir, Ozkan et al. (2015) Downregulation of the Host Gene jigr1 by miR-92 Is Essential for Neuroblast Self-Renewal in Drosophila. PLoS Genet 11:e1005264|
|West, Ryan J H; Lu, Yubing; Marie, Bruno et al. (2015) Rab8, POSH, and TAK1 regulate synaptic growth in a Drosophila model of frontotemporal dementia. J Cell Biol 208:931-47|
|Gascon, Eduardo; Lynch, Kelleen; Ruan, Hongyu et al. (2014) Alterations in microRNA-124 and AMPA receptors contribute to social behavioral deficits in frontotemporal dementia. Nat Med 20:1444-51|
|Gascon, Eduardo; Gao, Fen-Biao (2014) The emerging roles of microRNAs in the pathogenesis of frontotemporal dementia-amyotrophic lateral sclerosis (FTD-ALS) spectrum disorders. J Neurogenet 28:30-40|
|Gao, Fen-Biao; Taylor, J Paul (2014) RNA metabolism in neurological disease. Brain Res 1584:1-2|
|Simkin, Alfred T; Bailey, Jeffrey A; Gao, Fen-Biao et al. (2014) Inferring the evolutionary history of primate microRNA binding sites: overcoming motif counting biases. Mol Biol Evol 31:1894-901|
|Simkin, Alfred; Wong, Alex; Poh, Yu-Ping et al. (2013) Recurrent and recent selective sweeps in the piRNA pathway. Evolution 67:1081-90|
|Lu, Yubing; Zhang, Zhijun; Sun, Danqiong et al. (2013) Syntaxin 13, a genetic modifier of mutant CHMP2B in frontotemporal dementia, is required for autophagosome maturation. Mol Cell 52:264-71|
|Zhang, Zhijun; Almeida, Sandra; Lu, Yubing et al. (2013) Downregulation of microRNA-9 in iPSC-derived neurons of FTD/ALS patients with TDP-43 mutations. PLoS One 8:e76055|
|Li, Zhaodong; Lu, Yubing; Xu, Xia-Lian et al. (2013) The FTD/ALS-associated RNA-binding protein TDP-43 regulates the robustness of neuronal specification through microRNA-9a in Drosophila. Hum Mol Genet 22:218-25|
Showing the most recent 10 out of 20 publications