title: The ciliary proteins Meckelin and Jouberin are required for retinoic acid-dependent neural differentiation of mouse embryonic stem cells.
abstract: The dysfunction of the primary cilium, a complex, evolutionarily conserved, organelle playing an important role in sensing and transducing cell signals, is the unifying pathogenetic mechanism of a growing number of diseases collectively termed "ciliopathies", typically characterized by multiorgan involvement. Developmental defects of the central nervous system (CNS) characterize a subset of ciliopathies showing clinical and genetic overlap, such as Joubert syndrome (JS) and Meckel syndrome (MS). Although several knock-out mice lacking a variety of ciliary proteins have shown the importance of primary cilia in the development of the brain and CNS-derived structures, developmental in vitro studies, extremely useful to unravel the role of primary cilia along the course of neural differentiation, are still missing. Mouse embryonic stem cells (mESCs) have been recently proven to mimic brain development, giving the unique opportunity to dissect the CNS differentiation process along its sequential steps. In the present study we show that mESCs express the ciliary proteins Meckelin and Jouberin in a developmentally-regulated manner, and that these proteins co-localize with acetylated tubulin labeled cilia located at the outer embryonic layer. Further, mESCs differentiating along the neuronal lineage activate the cilia-dependent sonic hedgehog signaling machinery, which is impaired in Meckelin knock-out cells but results unaffected in Jouberin-deficient mESCs. However, both lose the ability to acquire a neuronal phenotype. Altogether, these results demonstrate a pivotal role of Meckelin and Jouberin during embryonic neural specification and indicate mESCs as a suitable tool to investigate the developmental impact of ciliary proteins dysfunction.
authors.affiliation: Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, FG, Italy.|Department of Molecular Medicine,"Sapienza" University, Rome, Italy.
authors.forename: Sveva
authors.initials: S
authors.lastname: Romani
authors.affiliation: Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, FG, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Illi
authors.affiliation: Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, FG, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: De Mori
authors.affiliation: Nucleic Acids Laboratory, Institute of Molecular Biology and Pathology, National Council of Research (IBPM-CNR), Rome, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Savino
authors.affiliation: Department of Neuroscience and Pediatrics, Neurogenetics Laboratory, Howard Hughes Medical Institute, University of California, La Jolla, San Diego, CA, USA.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Gleeson
authors.affiliation: Neurogenetics Unit, Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, FG, Italy.|Department of Medicine and Surgery, University of Salerno, Salerno, Italy.
authors.forename: Enza Maria
authors.initials: EM
authors.lastname: Valente
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D019070:Cell Lineage; D002478:Cells, Cultured; D002923:Cilia / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D053823:Hedgehog Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D058953:Neural Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D055495:Neurogenesis; D010641:Phenotype; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology; D014404:Tubulin / Q000235:genetics / Q000378:metabolism
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; C465818:Ahi1 protein, mouse; D053823:Hedgehog Proteins; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; C583064:TMEM67 protein, mouse; D014404:Tubulin; D014212:Tretinoin
keywords: Embryonic stem cells; Neural differentiation; Primary cilium