WNT5B Gene

WNT5B Gene

<div class="infobox infobox-gene">

| 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 |

</div>

Overview

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](/genes/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 [@wnt5b_wnt5a_comparison].

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 [@wnt5b_signaling].

WNT5B Gene

<div class="infobox infobox-gene">

| 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 |

</div>

Overview

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](/genes/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 [@wnt5b_wnt5a_comparison].

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 [@wnt5b_signaling].

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_wnt5a_comparison].

Function

Non-Canonical Wnt Signaling

WNT5B primarily signals through non-canonical Wnt pathways that do not involve β-catenin stabilization. These pathways include:

Planar Cell Polarity (PCP) Pathway

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

• Neuronal migration during cortical development
• Axon pathfinding and commissure formation
• Dendritic orientation and tiling

Calcium Signaling

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

Receptor Interactions

WNT5B signals through multiple receptor types with distinct downstream effects:

Frizzled Receptors

WNT5B binds to several FZD receptors, with highest affinity for FZD5 and FZD8 [@wnt5b_receptor]. The receptor repertoire determines downstream pathway specificity:

• FZD5 → Strong PCP signaling
• FZD8 → Calcium signaling predominates
• FZD3/FZD6 → Neuronal guidance

Ryk Receptor

WNT5B also signals through Ryk (Receptor-like Tyrosine Kinase), which is involved in:

• Axon guidance during development
• Synapse formation
• Adult neurogenesis

Neural Development

Cortical Development

WNT5B plays critical roles in cortical development through multiple mechanisms [@wnt5b_cortical]:

The spatial and temporal expression of WNT5B in the developing cortex creates signaling gradients that pattern neuronal positioning and connectivity.

Hippocampal Development

WNT5B is expressed in the developing hippocampus where it regulates [@wnt5b_hippocampus]:

• Dentate gyrus morphogenesis
• CA3-CA1 circuitry formation
• Axonal projections from entorhinal cortex to hippocampus

Axon Guidance

WNT5B is a potent axon guidance molecule that repels or attracts axons depending on context [@wnt5b_axon]. In developing neural circuits:

• WNT5B repels spinal cord commissural axons
• Attracts corticospinal tract axons
• Guides thalamocortical projections

Synaptic Function

WNT5B has direct functions at the synapse, where it regulates both synaptogenesis and synaptic plasticity [@wnt5b_synapse]:

Synapse Formation

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

Synaptic Plasticity

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

Neuroprotection

WNT5B has neuroprotective properties that may be relevant to neurodegenerative diseases:

• Promotes neuronal survival under oxidative stress
• Enhances mitochondrial function
• Reduces excitotoxicity
• Modulates neuroinflammation

Disease Associations

Alzheimer's Disease

WNT5B has multiple connections to Alzheimer's disease pathogenesis [@wnt5b_ad]:

Amyloid-Beta Effects

• Aβ oligomers reduce WNT5B expression in neurons
• WNT5B can protect against Aβ-induced toxicity
• WNT5B signaling is impaired in AD brain

Tau Pathology

• WNT5B expression correlates with tau pathology burden
• Hyperphosphorylated Tau affects WNT5B receptor expression
• WNT5B signaling may influence tau phosphorylation

Synaptic Dysfunction

• WNT5B is reduced in AD hippocampus
• Loss of WNT5B contributes to synapse loss
• WNT5B supplementation rescues synaptic plasticity in AD models

Neuroinflammation

• WNT5B modulates microglial activation [@wnt5b_inflammation]
• In AD, WNT5B-mediated anti-inflammatory signaling is impaired
• Restoring WNT5B may reduce neuroinflammation

Parkinson's Disease

WNT5B is implicated in Parkinson's disease through several mechanisms [@wnt5b_pd]:

Dopaminergic Neurons

• WNT5B is expressed in dopaminergic neurons of the substantia nigra
• WNT5B promotes dopaminergic neuron survival
• WNT5B expression is reduced in PD

Axonal Integrity

• WNT5B supports axonal maintenance
• Loss of WNT5B may contribute to axonal degeneration
• WNT5B signaling is important for nigrostriatal pathway integrity

α-Synuclein

• WNT5B interacts with α-synuclein pathology
• WNT5B can protect against α-synuclein toxicity
• Loss of WNT5B may accelerate α-synuclein aggregation

Neurodevelopmental Disorders

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

Cancer

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

Expression

Brain Expression

WNT5B is expressed throughout the brain with specific patterns [@wnt5b_neuronal]:

Neuronal Expression

• 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

Glial Expression

• Astrocytes: WNT5B expressed in astrocytes throughout the brain [@wnt5b_glia]
• Oligodendrocytes: Expression in developing and mature oligodendrocytes
• Microglia: Low baseline expression, upregulated with activation

Developmental Expression

WNT5B expression peaks during embryonic development and decreases in adulthood [@wnt5b_development]:

• 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

Aging

WNT5B expression decreases with age in the brain [@wnt5b_aging], which may contribute to:

• Declining synaptic plasticity
• Impaired neurogenesis
• Reduced neuroprotection

Signaling Pathways

Key Downstream Effectors

WNT5B activates multiple signaling cascades:

Cross-Talk with Other Pathways

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

Mechanisms in Neurodegeneration

Synaptic Failure

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

Neuroinflammation

WNT5B modulates neuroinflammatory responses [@wnt5b_inflammation]:

• In healthy brain, WNT5B maintains anti-inflammatory microglial state
• In neurodegeneration, WNT5B dysregulation fails to suppress inflammation
• Restoring WNT5B may reduce microglial activation

Impaired Neurogenesis

WNT5B is required for adult neurogenesis:

• Reduced WNT5B impairs NPC proliferation
• Decreased neuronal differentiation
• Reduced integration of new neurons

Axonal Degeneration

WNT5B supports axonal maintenance:

• Loss of WNT5B contributes to axonal dystrophy
• Impaired axonal transport
• Reduced axonal regeneration capacity

Therapeutic Implications

Given WNT5B's neuroprotective and plasticity-enhancing functions, it represents a potential therapeutic target:

Challenges include:

• Delivery across the blood-brain barrier
• Receptor specificity and pathway selectivity
• Potential off-target effects

Key Publications

See Also

• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [WNT5A Gene](/genes/wnt5a)
• [Wnt Signaling Pathway](/mechanisms/wnt-signaling-neurodegeneration)
• [Synaptic Plasticity](/mechanisms/activity-dependent-synaptic-plasticity)
• [Adult Neurogenesis](/mechanisms/adult-neurogenesis-neurodegeneration)

External Links

• [NCBI Gene: WNT5B](https://www.ncbi.nlm.nih.gov/gene/64640)
• [Ensembl: ENSG00000173230](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000173230)
• [UniProt: Q9H1J7](https://www.uniprot.org/uniprot/Q9H1J7)
• [GeneCards: WNT5B](https://www.genecards.org/cgi-bin/carddisp.pl?gene=WNT5B)
• [OMIM: WNT5B](https://omim.org/entry/609351)
• [Allen Brain Atlas: WNT5B](https://human.brain-map.org/microarray/search/show?search_term=WNT5B)

References