title: The neural crest-enriched microRNA miR-452 regulates epithelial-mesenchymal signaling in the first pharyngeal arch.
abstract: Neural crest cells (NCCs) are a subset of multipotent, migratory stem cells that populate a large number of tissues during development and are important for craniofacial and cardiac morphogenesis. Although microRNAs (miRNAs) have emerged as important regulators of development and disease, little is known about their role in NCC development. Here, we show that loss of miRNA biogenesis by NCC-specific disruption of murine Dicer results in embryos lacking craniofacial cartilaginous structures, cardiac outflow tract septation and thymic and dorsal root ganglia development. Dicer mutant embryos had reduced expression of Dlx2, a transcriptional regulator of pharyngeal arch development, in the first pharyngeal arch (PA1). miR-452 was enriched in NCCs, was sufficient to rescue Dlx2 expression in Dicer mutant pharyngeal arches, and regulated non-cell-autonomous signaling involving Wnt5a, Shh and Fgf8 that converged on Dlx2 regulation in PA1. Correspondingly, knockdown of miR-452 in vivo decreased Dlx2 expression in the mandibular component of PA1, leading to craniofacial defects. These results suggest that post-transcriptional regulation by miRNAs is required for differentiation of NCC-derived tissues and that miR-452 is involved in epithelial-mesenchymal signaling in the pharyngeal arch.
authors.affiliation: Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158, USA.
authors.forename: Neil T
authors.initials: NT
authors.lastname: Sheehy
authors.forename: Kimberly R
authors.initials: KR
authors.lastname: Cordes
authors.forename: Mark P
authors.initials: MP
authors.lastname: White
authors.forename: Kathryn N
authors.initials: KN
authors.lastname: Ivey
authors.forename: Deepak
authors.initials: D
authors.lastname: Srivastava
mesh_terms: D000818:Animals; D001934:Branchial Region / Q000196:embryology*; D002460:Cell Line; D053487:DEAD-box RNA Helicases / Q000235:genetics; D004722:Endoribonucleases / Q000235:genetics; D051524:Fibroblast Growth Factor 8 / Q000235:genetics; D053823:Hedgehog Proteins / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics; D017403:In Situ Hybridization; D051379:Mice; D008817:Mice, Mutant Strains; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009432:Neural Crest / Q000196:embryology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D043244:Ribonuclease III; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics; D051153:Wnt Proteins / Q000235:genetics; D000071818:Wnt-5a Protein
chemical_list: C088334:Distal-less homeobox proteins; C496457:Fgf8 protein, mouse; D053823:Hedgehog Proteins; D018398:Homeodomain Proteins; D035683:MicroRNAs; C465570:Shh protein, mouse; D014157:Transcription Factors; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; C438615:Wnt5a protein, mouse; D051524:Fibroblast Growth Factor 8; D004722:Endoribonucleases; C509781:Dicer1 protein, mouse; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases