A challenge in developmental neuroscience is to understand the molecular mechanisms underlying diversification of neuronal phenotypes derived from multipotent progenitor cells. The neural crest is a population of multipotent progenitors that gives rise to a rise to a diverse array of cell types including neurons of the peripheral nervous system. The differentiation of neural crest-derived cells into sympathetic catecholaminergic (CA) neurons requires exposure to growth factors encountered during their migration from the neural tube and at sites of localization. The mechanisms that control the generation of specific cell types are largely unknown for neural crest-derived cells, but most likely involve differential patterns of gene expression in response to both intrinsic and extrinsic cues. Neurogenic basic helix-loop-helix (bHLH) DNA binding proteins have been shown to control cell fate and phenotypic expression. However, there is little detailed information about the identity or actions of bHLH factors during vertebrate neurogenesis. Our hypothesis is that the expression of dHAND and eHAND, two novel bHLH factors we have recently cloned from chicken, is linked via growth factors to the regulation of neurogenesis and specification of CA neurotransmitter phenotype in neural crest- derived cells. The project will utilize molecular, cell biological and immunological approaches to define the role the dHAND and eHAND play in the development of neural crest-derived sympathetic ganglia. First, in situ hybridization combined with immunocytochemistry will be used to identify cell types expressing transcripts encoding dHAND and eHAND. The spatial and temporal patterns of expression of HAND gene transcripts will be determined. Second, to determine the functional role of dHAND and eHAND in the differentiation of CA neurons, the consequences of over expression of HAND gene products in neural crest-derived cells will be studied both in vitro and in vivo. The consequences of ectopic expression of HAND genes will be determined. Third, to identify upstream regulators and downstream targets of HAND proteins we will determine if growth factors known to influence CA differentiation affect HAND gene expression. Interactions between HAND proteins and other transcription factors important in CA differentiation will be assessed. Finally, we will try to rescue CA differentiation of crest cells from MASH1 null mice by expressing HAND proteins. Delineating how neural crest-derived cells begin to exhibit cell type-specific gene expression will enhance our understanding of basic developmental mechanisms underlying neurogenesis, and the origins of clinical manifestations of crest-derived neuroectodermal tumors.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS040644-02
Application #
6394543
Study Section
Special Emphasis Panel (ZRG1-SSS-Q (01))
Program Officer
Chiu, Arlene Y
Project Start
2000-07-01
Project End
2005-06-30
Budget Start
2001-07-01
Budget End
2002-06-30
Support Year
2
Fiscal Year
2001
Total Cost
$288,000
Indirect Cost
Name
University of Toledo
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
807418939
City
Toledo
State
OH
Country
United States
Zip Code
43614
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Jayakar, Selwyn S; Pugh, Phyllis C; Dale, Zack et al. (2014) PACAP induces plasticity at autonomic synapses by nAChR-dependent NOS1 activation and AKAP-mediated PKA targeting. Mol Cell Neurosci 63:1-12
Newgreen, Donald F; Dufour, Sylvie; Howard, Marthe J et al. (2013) Simple rules for a ""simple"" nervous system? Molecular and biomathematical approaches to enteric nervous system formation and malformation. Dev Biol 382:305-19
Vincentz, Joshua W; Firulli, Beth A; Lin, Andrea et al. (2013) Twist1 controls a cell-specification switch governing cell fate decisions within the cardiac neural crest. PLoS Genet 9:e1003405
Vincentz, Joshua W; VanDusen, Nathan J; Fleming, Andrew B et al. (2012) A Phox2- and Hand2-dependent Hand1 cis-regulatory element reveals a unique gene dosage requirement for Hand2 during sympathetic neurogenesis. J Neurosci 32:2110-20
Barron, Francie; Woods, Crystal; Kuhn, Katherine et al. (2011) Downregulation of Dlx5 and Dlx6 expression by Hand2 is essential for initiation of tongue morphogenesis. Development 138:2249-59
Lei, Jun; Howard, Marthe J (2011) Targeted deletion of Hand2 in enteric neural precursor cells affects its functions in neurogenesis, neurotransmitter specification and gangliogenesis, causing functional aganglionosis. Development 138:4789-800
Holler, Kristen L; Hendershot, Tyler J; Troy, Sophia E et al. (2010) Targeted deletion of Hand2 in cardiac neural crest-derived cells influences cardiac gene expression and outflow tract development. Dev Biol 341:291-304
Schmidt, Mirko; Lin, Shengyin; Pape, Manuela et al. (2009) The bHLH transcription factor Hand2 is essential for the maintenance of noradrenergic properties in differentiated sympathetic neurons. Dev Biol 329:191-200
Hendershot, Tyler J; Liu, Hongbin; Clouthier, David E et al. (2008) Conditional deletion of Hand2 reveals critical functions in neurogenesis and cell type-specific gene expression for development of neural crest-derived noradrenergic sympathetic ganglion neurons. Dev Biol 319:179-91

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