Identification of Noncanonical Wnt Receptors Required for Wnt-3a-Induced Early Differentiation of Human Neural Stem Cells

Abstract

Wnt proteins preferentially activate either β-catenin-dependent or β-catenin-independent signals, but the activity of a particular Wnt also depends on cellular context and receptor availability. We previously reported that Wnt-3a induces neural differentiation of human embryonic stem cell-derived neural stem cells (NSCs) in a β-catenin-independent manner by activating a signal involving JNK and the AP-1 family member ATF-2. Here, we report the results of a gene silencing approach to identify the Wnt receptors that mediate this response to Wnt-3a. Silencing of ROR2 increased neuronal differentiation, as measured by expression of the genes DCX, NEUROD1, and NGN1, suggesting ROR2 signals normally prevent differentiation. Silencing of the other Wnt receptors singly did not affect Wnt-3a-induced neuronal differentiation. However, pairwise silencing of ROR1 and FZD4 or FZD5 and of LRP6 and FZD4 or FZD5 inhibited neuronal differentiation, as detected by reductions in the expression of neuronal genes and immunocytochemical detection of DCX, NEUROD1 and DCX. Ectopic expression of these receptors in HEK 293 cells increased ATF2-dependent transcription. In addition, ROR1 coimmunoprecipitated with FZD4 and LRP6 in transfected HEK 293 cells and colocalized with FZD4 and with LRP6 at the cell surface of transfected L cells. Wnt-3a did not appear to affect these interactions but did alter the interactions between LRP6 and FZD4/5. Together, these observations highlight roles for ROR1, LRP6, FZD4, and FZD5 in neural stem cell differentiation and provide support for a model in which dynamic interactions among these receptors mediate Wnt-3a activation of ATF2 signaling.

Indonesian Ginger (Bangle) Extract Promotes Neurogenesis of Human Neural Stem Cells through WNT Pathway Activation

“…Microarray analysis revealed upregulation of TBR2, DCX, and DLX2, among other genes, after Bangle extract and c -Banglene treatment. Previous studies have suggested that WNT/β-catenin signaling is involved in regulating the expression of TBR2, which is a marker of intermediate progenitor cells and is essential for neurogenesis [ 33 , 34 ], and DCX in NSCs of humans and mice [ 35 , 36 ], and it regulates DLX2 expression in the fetal mouse brain [ 37 , 38 ]. DLX2 expression in NSCs is known to be sufficient for differentiation into GABAergic neurons [ 39 ].…”

Diverse roles for the ror‐family receptor tyrosine kinases in neurons and glial cells during development and repair of the nervous system

“…It is important to clarify whether Wnt5a‐Ror1 and Wnt5a‐Ror2 signaling affect division modes of NPCs in the developing neocortex. In human embryonic NPCs, Wnt3a, a representative canonical Wnt, can induce neural differentiation in a β‐catenin‐independent manner by activating JNK and ATF‐2 possibly through a receptor complex, comprising from Ror1, Fzd4/5, and LRP6 (Bengoa‐Vergniory et al, ).…”

First-in-class oral small molecule inhibitor of the tyrosine kinase ROR1 (KAN0439834) induced significant apoptosis of chronic lymphocytic leukemia cells

“…ROR1 and the co-receptor LRP6 may heterodimerize in CLL cells as part of signal transduction [ 13 ]. KAN0439834 dissociated the ROR1/LRP6 complex (Supplementary Figures 4A and B ) and the complex proteins were dephosphorylated (Fig.…”