Lithium Chloride Shows Promise in Restoring Neuronal Function Linked to WDFY3 Gene Variants
New Insights Into WDFY3-Related Neurodevelopmental Disorder
A recent study has provided an extensive characterization of loss-of-function (LoF) variants in the WDFY3 gene, a condition associated with neuropsychiatric symptoms such as autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), alongside mild to moderate developmental delays. This research, involving the largest cohort to date of 32 individuals, also noted variable brain growth patterns, most often macrocephaly (enlarged head size), with one case showing reduced head circumference.
Cellular and Molecular Effects of WDFY3 Deficiency
To explore the cellular consequences of WDFY3 LoF, scientists conducted knockdown (KD) experiments in human neuroblastoma cells (SH-SY5Y) and studied a mouse model with Wdfy3 haploinsufficiency (one functional copy of the gene). They observed that reducing WDFY3 impaired the clearance of protein aggregates and lowered levels of p62, a protein involved in cellular waste removal.
Further transcriptomic analyses revealed disruptions in gene networks critical for nervous system development, neuron projection, and key signaling pathways including MAPK/ERK1/2 and WNT/β-catenin. Protein studies confirmed these alterations. Notably, neuronal cell proliferation increased, as indicated by higher cell counts and proliferation markers (Ki-67 and PCNA), while neuronal differentiation was hindered, demonstrated by decreased neurite (neuron branch) outgrowth.
Role of WNT/β-catenin Signaling and Lithium Chloride Intervention
The study highlighted a decrease in β-catenin levels and an increase in GSK3B, an enzyme that negatively regulates β-catenin. Lithium chloride (LiCl) is known to activate WNT/β-catenin signaling by inhibiting GSK3B. Researchers tested LiCl treatment on Wdfy3-haploinsufficient neurons in vitro and found it significantly boosted WDFY3 expression.
Moreover, LiCl enhanced neurite branching beyond that seen in normal neurons, although this particular improvement appeared to occur independently of the WNT/β-catenin pathway. These findings suggest that lithium chloride may have therapeutic potential to improve neuronal function in individuals with WDFY3 LoF variants.
Implications for Families and Future Research
This study broadens understanding of the clinical and cellular features linked to WDFY3 gene disruptions and identifies lithium chloride as a candidate for further investigation as a treatment option. While promising, these results are preliminary and derived from cellular and animal models; clinical trials would be necessary to evaluate safety and effectiveness in patients.
Limitations and Cautions
It is important to note that the exact mechanisms by which lithium chloride improves neuronal features remain to be fully elucidated, especially given some effects appear independent of the targeted signaling pathway. Additionally, the variability in clinical presentation among individuals with WDFY3 LoF variants means that therapeutic responses may differ.
For families and clinicians, these findings offer hope for future interventions but underscore the need for cautious interpretation and further research.
For more detailed information, see the original study published in Molecular Psychiatry: Lithium chloride in vitro treatment shows potential to rescue the neuronal phenotype caused by WDFY3 haploinsufficiency.