Secreted Frizzled-related protein-2 (sFRP2) augments canonical Wnt3a-induced signaling

Journal Article · Fri Sep 24 04:00:00 EDT 2010 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2010.08.043· OSTI ID:22202777

Marschall, Zofia von ^[1]

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1. Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, DHHS, Bethesda, MD (United States)

Research highlights: {yields} sFRP2 enhances the Wnt3a-induced {beta}-catenin stabilization and its nuclear translocation. {yields} sFRP2 enhances LRP6 phosphorylation and Wnt3a/{beta}-catenin transcriptional reporter activity. {yields} Dickkopf-1 (DKK1) fully antagonizes both Wnt3a/sFRP2-induced LRP6 phosphorylation and transcriptional activity. {yields} sFRP2 enhances expression of genes known to be regulated by Wnt3a signaling. -- Abstract: Secreted Frizzled-related proteins (sFRP) are involved in embryonic development as well as pathological conditions including bone and myocardial disorders and cancer. Because of their sequence homology with the Wnt-binding domain of Frizzled, they have generally been considered antagonists of canonical Wnt signaling. However, additional activities of various sFRPs including both synergism and mimicry of Wnt signaling as well as functions other than modulation of Wnt signaling have been reported. Using human embryonic kidney cells (HEK293A), we found that sFRP2 enhanced Wnt3a-dependent phosphorylation of LRP6 as well as both cytosolic {beta}-catenin levels and its nuclear translocation. While addition of recombinant sFRP2 had no activity by itself, Top/Fop luciferase reporter assays showed a dose-dependent increase of Wnt3a-mediated transcriptional activity. sFRP2 enhancement of Wnt3a signaling was abolished by treatment with the Wnt antagonist, Dickkopf-1 (DKK1). Wnt-signaling pathway qPCR arrays showed that sFRP2 enhanced the Wnt3a-mediated transcriptional up-regulation of several genes regulated by Wnt3a including its antagonists, DKK1, and Naked cuticle-1 homolog (NKD1). These results support sFRP2's role as an enhancer of Wnt/{beta}-catenin signaling, a result with biological impact for both normal development and diverse pathologies such as tumorigenesis.

• OSTI ID: 22202777
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 3 Vol. 400; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
GENE REGULATION
GENES
LIPOPROTEINS
LUCIFERASE
NEOPLASMS
ONTOGENESIS
PATHOLOGY
PHOSPHORYLATION
RECEPTORS
SKELETON
SYNERGISM
TRANSLOCATION