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Loss of lnx1 impairs vascular development mediated by reduction of VEGF/ERK and BMP signalings
Author(s) -
Chen Zihying,
Wu ChangYi
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.586.6
Subject(s) - morpholino , gene knockdown , microbiology and biotechnology , biology , zebrafish , genetics , gene
Using zebrafish as a model organism to study vascular development have been intensively identified many molecules that control artery‐vein identity, intersegmental vessel (ISV) patterning and caudal vein plexus (CVP) formation. However, molecular mechanisms of ISV patterning and CVP formation are not fully discovered. We previous identified nr2f1b controls vein, ISV and CVP growth. We further investigated the potential regulated targets of nr2f1b by microarray strategy, and identified ligand of numb‐protein X1 ( lnx1 ) as a potential target that may mediate vascular development. Amino acid sequence alignment and phylogenetic analysis revealed that lnx1 is highly conserved in vertebrates and we showed that lnx1 mRNA is expressed in developing vessels. Morpholino knockdown of lnx1 impairs the growth of ISV and CVP, suggesting the role of lnx1 in promoting ISV and CVP growth. We further observed the edema and circulation defects associated with the vessel impairment. We next demonstrated the reduction of ISV cells and decrease of CVP endothelial cells sprouting in lnx1 morphants is due to a decrease of cell proliferation and migration, but not results from cell death in non‐endothelial cells. Consistent with the vascular defects in lnx1 morphants, the expression of vascular markers was decreased. To test the specificity of lnx1 morpholino knockdown, we performed the 2nd MO interfere block splicing site and knockdown efficiently by probing lnx1 expression products. Meanwhile, know down of lnx1 by 2 different morpholinos led to similar defects of vasculature and reduced expression of vascular markers; we also performed mRNA rescue experiments. Finally, we examined the interaction between signaling pathways and lnx1 . We found inactivation of VEGF and BMP signals reduced the expression of lnx1 , and knockdown of lnx1 caused reductions in vegfaa and ERK expression. Together, we conclude that the loss of lnx1 impairs vascular development, which is mediated by VEGF‐ERK and BMP signals.