Stem cells in the embryonic vertebrate olfactory epithelium (OE) generate critical peripheral chemosensory and central neuroendocrine neurons-essential for feeding, social interactions, and reproduction. Nevertheless, mechanisms for establishing and maintaining these embryonic OE stem cells remain unknown. The progeny of embryonic OE stem cells are retained as progenitors throughout life to constantly replace OE chemosensory neurons;however the relationship between embryonic and adult OE stem cells is largely unexplored. We have recently defined apparent stem and transit amplifying cell populations in the embryonic OE. Apparent embryonic OE stem cells express high levels of the transcription factor Meis1 as well as low levels of Sox2, divide slowly and symmetrically, and are necessary for the genesis of olfactory and vomeronasal receptor neurons (ORNs, VRNs) and gonadotropin releasing hormone (GnRH) neurons-the OE neuronal lineage. The apparent transit amplifying cells express neurogenic bHLH genes including Ascl1 as well as high levels of Sox2, undergo rapid terminal neurogenic divisions, and expand numbers of ORNs, VRNs and GnRH neurons. We will now establish transcription regulatory and signaling mechanisms that determine the identity, proliferative capacity, and progression of OE stem or transit amplifying cells through the OE neurogenic lineage. We will determine how embryonic OE stem or transit amplifying cells with distinct transcriptional and signaling histories give rise to precursor populations established in the embryonic OE and retained in the adult to generate ORNs and VRNs throughout life.
Specific Aim 1 will define differential influences of transcriptional regulators on OE stem versus transit amplifying cells.
Specific Aim 2 will establish molecular mechanisms that underlie a transcription regulatory network essential for OE stem cell identity and lineage progression.
Specific Aim 3 will establish the role of local signaling in defining and maintaining a niche for embryonic OE stem cells.
Specific Aim 4 will relate the identity of subsets of embryonic OE stem and transit amplifying cells to adult OE progenitor populations. Our experiments therefore provide a mechanistic account of how OE stem cells are established, and how they are regulated to generate ORNs, VRNs and GnRH neurons. The data provide insight into how stem cells in specific niches mediate histogenesis and tissue repair. Our investigation of molecular mechanisms underlying OE stem cell regulation will also identify potential targets for degenerative change associated with diminished olfaction in a number of neurological and psychiatric disorders including Parkinson's and Alzheimer's diseases as well as schizophrenia.

Public Health Relevance

Neural stem cells in the olfactory epithelium (OE) arise in the embryo and are retained throughout life to make neurons that are essential for smell, feeding, social interactions and reproduction. These stem cells may be compromised in several neurodegenerative conditions in which olfactory deficits are early indicators of disease. This project will identify molecular mechanisms that define embryonic OE stem cells, regulate lifelong genesis of olfactory neurons, and are likely pathogenic targets for neurological and psychiatric diseases.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
Research Project (R01)
Project #
Application #
Study Section
Somatosensory and Chemosensory Systems Study Section (SCS)
Program Officer
Sullivan, Susan L
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
George Washington University
Schools of Medicine
United States
Zip Code
Sherman, Jonathan H; Karpinski, Beverly A; Fralish, Matthew S et al. (2017) Foxd4 is essential for establishing neural cell fate and for neuronal differentiation. Genesis 55:
Karpinski, Beverly A; Bryan, Corey A; Paronett, Elizabeth M et al. (2016) A cellular and molecular mosaic establishes growth and differentiation states for cranial sensory neurons. Dev Biol 415:228-241
Baker, Jennifer L; Wood, Bernard; Karpinski, Beverly A et al. (2016) Testicular receptor 2, Nr2c1, is associated with stem cells in the developing olfactory epithelium and other cranial sensory and skeletal structures. Gene Expr Patterns 20:71-9
LaMantia, Anthony-Samuel; Moody, Sally A; Maynard, Thomas M et al. (2016) Hard to swallow: Developmental biological insights into pediatric dysphagia. Dev Biol 409:329-42
Chau, Kevin F; Springel, Mark W; Broadbelt, Kevin G et al. (2015) Progressive Differentiation and Instructive Capacities of Amniotic Fluid and Cerebrospinal Fluid Proteomes following Neural Tube Closure. Dev Cell 35:789-802
Meechan, Daniel W; Maynard, Thomas M; Tucker, Eric S et al. (2015) Modeling a model: Mouse genetics, 22q11.2 Deletion Syndrome, and disorders of cortical circuit development. Prog Neurobiol 130:1-28
Moody, Sally A; LaMantia, Anthony-Samuel (2015) Transcriptional regulation of cranial sensory placode development. Curr Top Dev Biol 111:301-50
Sarkar, Anjali A; Nuwayhid, Samer J; Maynard, Thomas et al. (2014) Hectd1 is required for development of the junctional zone of the placenta. Dev Biol 392:368-80
Karpinski, Beverly A; Maynard, Thomas M; Fralish, Matthew S et al. (2014) Dysphagia and disrupted cranial nerve development in a mouse model of DiGeorge (22q11) deletion syndrome. Dis Model Mech 7:245-57
Moody, Sally A; Klein, Steven L; Karpinski, Beverley A et al. (2013) On becoming neural: what the embryo can tell us about differentiating neural stem cells. Am J Stem Cells 2:74-94

Showing the most recent 10 out of 12 publications