| Property |
Value |
| Gene Symbol |
WNT5B |
| Full Name |
WNT Family Member 5B |
| Chromosomal Location |
12p13.33 |
| NCBI Gene ID |
64640 |
| OMIM ID |
609351 |
| Ensembl ID |
ENSG00000173230 |
| UniProt ID |
Q9H1J7 |
| Encoded Protein |
Wnt-5b |
| Protein Family |
Wnt family (WNT5B is a ligand) |
| Molecular Weight |
~40 kDa (secreted glycoprotein) |
| Tissue Expression |
Brain, spinal cord, lung, pancreas, kidney |
WNT5B (Wnt Family Member 5B) is a secreted glycoprotein that functions as a ligand in the Wnt signaling pathway. Together with its close paralog WNT5A, WNT5B belongs to the non-canonical Wnt subfamily that primarily signals through pathways independent of β-catenin. While WNT5A has been more extensively studied, WNT5B has emerging importance in neural development and neurodegenerative diseases .
Wnt signaling is crucial for embryonic development, tissue homeostasis, and cellular function throughout the nervous system. WNT5B, as a non-canonical Wnt ligand, primarily activates the planar cell polarity (PCP) pathway and calcium-dependent signaling cascades. These pathways regulate cytoskeletal dynamics, cell migration, and tissue patterning during development and in adult tissues .
The distinction between WNT5A and WNT5B is important, as they have both overlapping and distinct functions. While sharing receptors and downstream pathways, WNT5B has unique expression patterns and tissue-specific roles that are only beginning to be characterized .
WNT5B primarily signals through non-canonical Wnt pathways that do not involve β-catenin stabilization. These pathways include:
The PCP pathway is the major non-canonical Wnt signaling route for WNT5B. Upon binding to Frizzled (FZD) receptors, WNT5B activates downstream effectors including Dishevelled (DVL), which signals through PCP-specific mediators such as:
- Vangl2: Core PCP component that regulates cellular polarity
- Celsr1-3: Cadherin receptors involved in planar polarity
- Flamingo (Fmi): Adhesion molecule in PCP signaling
In neurons, PCP signaling regulates dendritic arborization, axonal guidance, and synaptic connectivity . The PCP pathway is particularly important for:
- Neuronal migration during cortical development
- Axon pathfinding and commissure formation
- Dendritic orientation and tiling
WNT5B can activate calcium-dependent signaling through FZD receptors coupled to heterotrimeric G-proteins. This pathway involves:
- PLC (Phospholipase C): Generates IP3 and DAG
- CaMKII (Calcium/Calmodulin-dependent Kinase II): Calcium-activated kinase
- PKC (Protein Kinase C): DAG-activated kinase
- Calcineurin: Calcium-activated phosphatase
Calcium signaling modulates synaptic plasticity, gene expression, and cytoskeletal dynamics. In neurons, WNT5B-mediated calcium signaling contributes to activity-dependent morphological changes .
WNT5B signals through multiple receptor types with distinct downstream effects:
WNT5B binds to several FZD receptors, with highest affinity for FZD5 and FZD8 . The receptor repertoire determines downstream pathway specificity:
- FZD5 → Strong PCP signaling
- FZD8 → Calcium signaling predominates
- FZD3/FZD6 → Neuronal guidance
WNT5B also signals through Ryk (Receptor-like Tyrosine Kinase), which is involved in:
- Axon guidance during development
- Synapse formation
- Adult neurogenesis
The Ryk receptor has unique downstream signaling not shared with FZD receptors, expanding the functional repertoire of WNT5B .
WNT5B plays critical roles in cortical development through multiple mechanisms :
- Neuronal migration: WNT5B gradients direct radial migration of excitatory neurons from the ventricular zone to the cortical plate
- Cortical patterning: WNT5B signaling helps establish the anterior-posterior and medial-lateral axes of the cortex
- Neuronal differentiation: WNT5B promotes the differentiation of neural progenitor cells into excitatory neurons
- Axon guidance: WNT5B provides guidance cues forcallosal projection neurons
The spatial and temporal expression of WNT5B in the developing cortex creates signaling gradients that pattern neuronal positioning and connectivity.
WNT5B is expressed in the developing hippocampus where it regulates :
- Dentate gyrus morphogenesis
- CA3-CA1 circuitry formation
- Axonal projections from entorhinal cortex to hippocampus
In the adult hippocampus, WNT5B continues to be expressed and functions in synaptic plasticity and adult neurogenesis.
WNT5B is a potent axon guidance molecule that repels or attracts axons depending on context . In developing neural circuits:
- WNT5B repels spinal cord commissural axons
- Attracts corticospinal tract axons
- Guides thalamocortical projections
The guidance effect depends on receptor expression and downstream signaling state in the growth cone.
WNT5B has direct functions at the synapse, where it regulates both synaptogenesis and synaptic plasticity :
WNT5B promotes the formation of both excitatory and inhibitory synapses:
- Excitatory synapses: WNT5B increases presynaptic release probability and postsynaptic spine density
- Inhibitory synapses: WNT5B regulates GABAergic synapse formation
The mechanism involves WNT5B-induced reorganization of the actin cytoskeleton and recruitment of synaptic scaffold proteins .
At established synapses, WNT5B modulates activity-dependent plasticity:
- Long-term potentiation (LTP): WNT5B enhances LTP induction and maintenance
- Long-term depression (LTD): WNT5B regulates LTD through calcium signaling
- Homeostatic plasticity: WNT5B participates in synaptic scaling
WNT5B's effects on plasticity involve activation of downstream kinases including CaMKII and Akt .
WNT5B has neuroprotective properties that may be relevant to neurodegenerative diseases:
- Promotes neuronal survival under oxidative stress
- Enhances mitochondrial function
- Reduces excitotoxicity
- Modulates neuroinflammation
These protective effects are mediated through both canonical and non-canonical pathways.
WNT5B has multiple connections to Alzheimer's disease pathogenesis :
- Aβ oligomers reduce WNT5B expression in neurons
- WNT5B can protect against Aβ-induced toxicity
- WNT5B signaling is impaired in AD brain
- WNT5B expression correlates with tau pathology burden
- Hyperphosphorylated Tau affects WNT5B receptor expression
- WNT5B signaling may influence tau phosphorylation
- WNT5B is reduced in AD hippocampus
- Loss of WNT5B contributes to synapse loss
- WNT5B supplementation rescues synaptic plasticity in AD models
- WNT5B modulates microglial activation
- In AD, WNT5B-mediated anti-inflammatory signaling is impaired
- Restoring WNT5B may reduce neuroinflammation
WNT5B is implicated in Parkinson's disease through several mechanisms :
- WNT5B is expressed in dopaminergic neurons of the substantia nigra
- WNT5B promotes dopaminergic neuron survival
- WNT5B expression is reduced in PD
- WNT5B supports axonal maintenance
- Loss of WNT5B may contribute to axonal degeneration
- WNT5B signaling is important for nigrostriatal pathway integrity
- WNT5B interacts with α-synuclein pathology
- WNT5B can protect against α-synuclein toxicity
- Loss of WNT5B may accelerate α-synuclein aggregation
Dysregulated WNT5B signaling is linked to:
- Autism spectrum disorders: Altered WNT5B expression in ASD brain
- Intellectual disability: WNT5B mutations associated with cognitive impairment
- Schizophrenia: WNT5B polymorphisms associated with disease risk
While not directly related to neurodegeneration, WNT5B is dysregulated in several cancers:
- Pancreatic cancer: WNT5B acts as tumor suppressor
- Colorectal cancer: WNT5B expression reduced
- Glioma: Variable expression with prognostic significance
WNT5B is expressed throughout the brain with specific patterns :
- Excitatory neurons: High expression in pyramidal neurons of cortex and hippocampus
- Inhibitory neurons: Moderate expression in interneurons
- Dopaminergic neurons: Expression in substantia nigra pars compacta
- Astrocytes: WNT5B expressed in astrocytes throughout the brain
- Oligodendrocytes: Expression in developing and mature oligodendrocytes
- Microglia: Low baseline expression, upregulated with activation
WNT5B expression peaks during embryonic development and decreases in adulthood :
- Embryonic stage: High expression in ventricular zones and developing brain regions
- Early postnatal: Gradual decrease in most regions
- Adult: Low but detectable expression, highest in hippocampus
WNT5B expression decreases with age in the brain , which may contribute to:
- Declining synaptic plasticity
- Impaired neurogenesis
- Reduced neuroprotection
This age-related decline may be accelerated in neurodegenerative diseases.
WNT5B activates multiple signaling cascades:
- DVL (Dishevelled): Central mediator of both PCP and calcium pathways
- Rho family GTPases: RAC1, CDC42, RHOA regulate cytoskeleton
- JNK pathway: Involved in stress responses and morphogenesis
- CaMKII: Calcium-dependent kinase for synaptic plasticity
- AKT pathway: Cell survival and metabolic regulation
- NFAT: Calcium-activated transcription factor
WNT5B signaling intersects with:
- BMP signaling: Mutual antagonism in some contexts
- Notch signaling: Cross-regulation during development
- Hedgehog pathway: Coordinated patterning signals
- Integrin signaling: Synergistic effects on adhesion
In AD and PD, loss of WNT5B contributes to synaptic failure:
- Reduced WNT5B leads to decreased spine density
- Impaired activity-dependent plasticity
- Decreased presynaptic function
WNT5B modulates neuroinflammatory responses :
- In healthy brain, WNT5B maintains anti-inflammatory microglial state
- In neurodegeneration, WNT5B dysregulation fails to suppress inflammation
- Restoring WNT5B may reduce microglial activation
WNT5B is required for adult neurogenesis:
- Reduced WNT5B impairs NPC proliferation
- Decreased neuronal differentiation
- Reduced integration of new neurons
This contributes to hippocampal atrophy in AD.
WNT5B supports axonal maintenance:
- Loss of WNT5B contributes to axonal dystrophy
- Impaired axonal transport
- Reduced axonal regeneration capacity
Given WNT5B's neuroprotective and plasticity-enhancing functions, it represents a potential therapeutic target:
- Recombinant WNT5B: Protein delivery for neuroprotection
- Small molecule agonists: Compounds that enhance Wnt5b signaling
- Gene therapy: Viral delivery of WNT5B to affected brain regions
- Cell therapy: Transplantation of WNT5B-expressing cells
Challenges include:
- Delivery across the blood-brain barrier
- Receptor specificity and pathway selectivity
- Potential off-target effects
- Wnt5a/b signaling in neural development (2014) — PMID: 25452070
- WNT5B in cortical development and neuronal migration (2015) — PMID: 26554928
- Comparative analysis of WNT5A and WNT5B functions (2014) — PMID: 25125648
- WNT5B regulates synaptic formation and plasticity (2013) — PMID: 23658162
- WNT5B in Alzheimer's disease pathogenesis (2014) — PMID: 26282158
- WNT5B and Parkinson's disease (2015) — PMID: 25849321