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miR ‐199 family contributes to regulation of sonic hedgehog expression during craniofacial development
Author(s) -
Richbourg Heather A.,
Hu Diane P.,
Xu Yanhua,
Barczak Andrea J.,
Marcucio Ralph S.
Publication year - 2020
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.191
Subject(s) - sonic hedgehog , biology , microbiology and biotechnology , hedgehog signaling pathway , microrna , gli1 , mesenchyme , signal transduction , medicine , endocrinology , genetics , gene , embryo
Abstract Background The frontonasal ectodermal zone (FEZ) is a signaling center that regulates patterned development of the upper jaw, and Sonic hedgehog (SHH) mediates FEZ activity. Induction of SHH expression in the FEZ results from SHH‐dependent signals from the brain and neural crest cells. Given the role of miRNAs in modulating gene expression, we investigated the extent to which miRNAs regulate SHH expression and FEZ signaling. Results In the FEZ, the miR‐199 family appears to be regulated by SHH‐dependent signals from the brain; expression of this family increased from HH18 to HH22, and upon activation of SHH signaling in the brain. However, the miR‐199 family is more broadly expressed in the mesenchyme of the frontonasal process and adjacent neuroepithelium. Downregulating the miR‐199 genes expanded SHH expression in the FEZ, resulting in wider faces, while upregulating miR‐199 genes resulted in decreased SHH expression and narrow faces. Hypoxia inducible factor 1 alpha (HIF1A) and mitogen‐activated protein kinase kinase kinase 4 (MAP3K4) appear to be potential targets of miR‐199b. Reduction of MAP3K4 altered beak development but increased apoptosis, while reducing HIF1A reduced expression of SHH in the FEZ and produced malformations independent of apoptosis. Conclusions Our results demonstrate that this miRNA family appears to participate in regulating SHH expression in the FEZ; however, specific molecular mechanisms remain unknown.