The major aims of this proposal are to identify mechanisms underlying midface development that are controlled by PDGF signaling. Loss of the PDGFRa or of its ligands PDGFA and PDGFC lead to facial clefting and improper development of the frontonasal process, whereas hypomorphic mutations in this pathway result in cleft palate. This application proposes: 1. To characterize the processes regulated by PDGFRa in cranial neural crest cells and craniofacial development. Loss of PDGFRa signaling affects two distinct processes, the development of the frontonasal masses and fusion at the midline. We will assess the ability of cranial neural crest cells to populate the frontonasal mass in PDGFRa conditional and hypomorphic mutants, using in vivo Cre lineage tracing and in vitro chemotaxis assays and cranial neural crest cell explants. We will also examine in detail the development of the frontonasal masses and midline fusion. 2. To investigate the pathways that operate downstream of PDGF engaged PI3K/AKT signaling in craniofacial development. Our previous genetic experiments have assigned a central role to the PI3K signaling pathway in mediating PDGF activity in craniofacial development, but further downstream pathways remain unknown. We will identify by mass spectroscopy the phosphorylation targets of PI3K/AKT in primary palatal mesenchyme cells. Genetic epistasis experiments between PDGFRa and phosphorylation target mutants will be conducted to identify their role in craniofacial development. 3. To establish a genetic pathway that instructs craniofacial patterning downstream of PDGF signaling. We have identified a number of transcriptional targets of PDGF in primary palatal mesenchymal cells, which are involved in cell migration and pattern specification in the frontonasal process and the palate. A selection of these PDGF target genes will be used to isolate mouse mutants. Phenotyping will be performed in null or conditional target gene mutants to determine changes in the frontonasal process and the palate. Genetic interactions with PDGFRa mutants will be performed to establish a genetic pathway operating downstream of PDGF in craniofacial development. Among growth factor signaling pathways, PDGF signaling has been exquisitely analyzed at a molecular and cellular level, and the proposed studies are anticipated to have significant impact in craniofacial biology because of the insight provided by this detailed knowledge. This proposal will thus open new directions for the prevention of craniofacial birth defects.

Public Health Relevance

Craniofacial developmental diseases including cleft lip or palate are the most prevalent birth defects in the human population worldwide. The major aims of this proposal are to identify mechanisms controlled by PDGF signaling that underlie normal development of the midface. We will investigate how PDGF controls neural crest cell migration, identify downstream intracellular signaling pathways involved in midline development, and characterize the transcriptional targets that mediate these processes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE022363-02
Application #
8383096
Study Section
Skeletal Biology Development and Disease Study Section (SBDD)
Program Officer
Scholnick, Steven
Project Start
2011-12-01
Project End
2016-11-30
Budget Start
2012-12-01
Budget End
2013-11-30
Support Year
2
Fiscal Year
2013
Total Cost
$670,874
Indirect Cost
$271,932
Name
Icahn School of Medicine at Mount Sinai
Department
Biology
Type
Schools of Medicine
DUNS #
078861598
City
New York
State
NY
Country
United States
Zip Code
10029
Vasudevan, Harish N; Soriano, Philippe (2014) SRF regulates craniofacial development through selective recruitment of MRTF cofactors by PDGF signaling. Dev Cell 31:332-44
Fantauzzo, Katherine A; Soriano, Philippe (2014) PI3K-mediated PDGFR? signaling regulates survival and proliferation in skeletal development through p53-dependent intracellular pathways. Genes Dev 28:1005-17
He, Fenglei; Soriano, Philippe (2013) A critical role for PDGFR* signaling in medial nasal process development. PLoS Genet 9:e1003851
Lewis, Ace E; Vasudevan, Harish N; O'Neill, Audrey K et al. (2013) The widely used Wnt1-Cre transgene causes developmental phenotypes by ectopic activation of Wnt signaling. Dev Biol 379:229-34