title: Targeted disruption of NeuroD, a proneural basic helix-loop-helix factor, impairs distal lung formation and neuroendocrine morphology in the neonatal lung.
abstract: Despite the importance of airspace integrity in vertebrate gas exchange, the molecular pathways that instruct distal lung formation are poorly understood. Recently, we found that fibrillin-1 deficiency in mice impairs alveolar formation and recapitulates the pulmonary features of human Marfan syndrome. To further elucidate effectors involved in distal lung formation, we performed expression profiling analysis comparing the fibrillin-1-deficient and wild-type developing lung. NeuroD, a basic helix-loop-helix transcription factor, fulfilled the expression criteria for a candidate mediator of distal lung development. We investigated its role in murine lung development using genetically targeted NeuroD-deficient mice. We found that NeuroD deficiency results in both impaired alveolar septation and altered morphology of the pulmonary neuroendocrine cells. NeuroD-deficient mice had enlarged alveoli associated with reduced epithelial proliferation in the airway and airspace compartments during development. Additionally, the neuroendocrine compartment in these mice manifested an increased number of neuroepithelial bodies but a reduced number of solitary pulmonary neuroendocrine cells in the neonatal lung. Overexpression of NeuroD in a murine lung epithelial cell line conferred a neuroendocrine phenotype characterized by the induction of neuroendocrine markers as well as increased proliferation. These results support an unanticipated role for NeuroD in the regulation of pulmonary neuroendocrine and alveolar morphogenesis and suggest an intimate connection between the neuroendocrine compartment and distal lung development.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Institute of Genetic Medicine, Howard Hughes Medical Institute, Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Enid R
authors.initials: ER
authors.lastname: Neptune
authors.forename: Megan
authors.initials: M
authors.lastname: Podowski
authors.forename: Carla
authors.initials: C
authors.lastname: Calvi
authors.forename: Jang-Hyeon
authors.initials: JH
authors.lastname: Cho
authors.forename: Joe G N
authors.initials: JG
authors.lastname: Garcia
authors.forename: Rubin
authors.initials: R
authors.lastname: Tuder
authors.forename: R Ilona
authors.initials: RI
authors.lastname: Linnoila
authors.forename: Ming-Jer
authors.initials: MJ
authors.lastname: Tsai
authors.forename: Harry C
authors.initials: HC
authors.lastname: Dietz
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D002460:Cell Line; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000166:cytology; D000071838:Fibrillin-1; D000071837:Fibrillins; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006579:Heterozygote; D006801:Humans; D008168:Lung / Q000378:metabolism*; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D010641:Phenotype; D014162:Transfection; D054392:Adipokines
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D000071838:Fibrillin-1; D000071837:Fibrillins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; C000605722:FBN1 protein, human; D054392:Adipokines; C000605724:Fbn1 protein, mouse; C093564:Neurogenic differentiation factor 1