bioRxiv Science⌕ Search

bioRxiv · 10.1101/2024.05.28.596232

Deficiency of the histone lysine demethylase KDM5B causes autism-like phenotypes via increased NMDAR signalling

Abstract

Loss-of-function mutations in genes encoding lysine methyltransferases (KMTs) and demethylases (KDMs) responsible for regulating the trimethylation of histone 3 on lysine 4 (H3K4me3) are associated with neurodevelopmental conditions, including autism spectrum disorder and intellectual disability. To study the specific role of H3K4me3 demethylation, we investigated neurodevelopmental phenotypes in mice without KDM5B demethylase activity. These mice exhibited autism-like behaviours and increased brain size. H3K4me3 levels and the expression of neurodevelopmental genes were increased in the developing Kdm5b mutant neocortex. These included elevated expression of Grin2d. The Grin2d gene product NMDAR2D was increased in synaptosomes isolated from the Kdm5b-deficient neocortex and treating mice with the NMDAR antagonist memantine rescued deficits in ultrasonic vocalisations and reduced repetitive digging behaviours. These findings suggest that increased H3K4me3 levels and associated Grin2d gene upregulation disrupt brain development and function, leading to socio-communication deficits and repetitive behaviours, and identify a potential therapeutic target for neurodevelopmental disorders associated with KDM5B deficiency. TeaserInhibitors targeting NMDA receptors may represent viable therapies for KDM5B neurodevelopmental disorders

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Perez-Sisques, L., Bhatt, S. U., Caruso, A., Ahmed, M. U., Gileadi, T. E., Spring, S., Hendy, E., Taylor-Papadimitriou, J., Cash, D., Clifton, N., Ellegood, J., Andreae, L. C., Lerch, J. P., Scattoni, M. L., Giese, K. P., Fernandes, C., Basson, M. A.. 2024-05-29. Deficiency of the histone lysine demethylase KDM5B causes autism-like phenotypes via increased NMDAR signalling. https://doi.org/10.1101/2024.05.28.596232

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

A systems-level model of sleep-dependent memory-consolidation failure in neurodegeneration: the spindle-slow-oscillation decoupling cascade dissociates amyloid and tau

During non-rapid-eye-movement (NREM) sleep, the temporal coupling of cortical slow oscillations (SOs), thalamic spindles, and hippocampal sharp wave ripples drives the consolidation of declarative memories. This coupling degrades in ageing and Alzheimers disease (AD), and although A{beta} and tau leave dissociable signatures in human sleep, the mechanisms by which progressive pathology dismantles the consolidation machinery are difficult to isolate experimentally, and have not to our knowledge been reproduced in a model that can be perturbed directly. We built a systems-level model in which cortical SOs and thalamic spindles are generated by reduced oscillators, hippocampal ripples replay encoded spike sequences, and the measured per-event SO-spindle timing alignment causally gates spike-timing dependent plasticity on cortical sequence synapses. A post-sleep cued-recall test reads out consolidation. Five neurodegeneration parameters (amyloid, tau, synaptic density, GABAergic inhibition, cholinergic tone) map to dis tinct mechanisms grounded in the human and animal literature. The model reproduces graded healthy consolidation and a progressive collapse in which coupling, slow-wave power, spindle power and recall fall monotonically and the overnight memory effect flips from consolidation to net forgetting, with weak memories failing first. Scrambling SO-spindle timing while holding oscillation power fixed abolishes consolidation, establishing that coupling timing, rather than oscillation power, is what the plasticity gate depends on within the model. A{beta} and tau impair memory through orthogonal signatures (A{beta} collapses slow-wave power while sparing replay order, tau the reverse) and this orthogonality holds across the entire A{beta} x tau plane and survives simultaneous {+/-}50% resampling of every mapping coefficient (40/40 samples), so it is not an artefact of a single calibration point. The model yields a falsifiable clinical prediction: closed-loop slow-oscillation enhancement rescues memory only when the deficit is amplitude/coupling-dominated, not when it is replay(tau)-dominated, despite normalising slow-wave power in both cases. Because the therapy arms dissociate coupling from memory benefit, the model also cautions against adopting SO-spindle coupling as a standalone surrogate endpoint.

neuroscience↗

Toxicity of MAPT 4R RNA Contributes to Motor Neuron Degeneration in ALS

MAPT (Tau) dysregulation is implicated in several neurodegenerative diseases, but its contribution to amyotrophic lateral sclerosis (ALS) is poorly understood. Here we show that mRNA isoforms encoding 4-repeat (4R) Tau are upregulated and cytoplasmically enriched in iPSC-derived motor neurons (MNs) from VCP-mutant and sporadic ALS, without a corresponding change in Tau protein. Using splice-switching antisense oligonucleotides and isoform-specific siRNAs, we find that enhanced 4R expression reduces MN viability, whereas its selective knockdown improves survival, with kinetics more consistent with an RNA-intrinsic effect than altered protein synthesis. Exon 10-containing MAPT RNA shows increased predicted secondary structure, self-association and altered Tau biocondensation in vitro. In post-mortem ALS cervical spinal cord, increased relative exon 10 usage is associated with a higher-risk clinical phenotype and shorter disease duration These findings identify an isoform-specific contribution of MAPT to MN vulnerability in ALS and nominate 4R MAPT RNA as a therapeutic target.

neuroscience↗

State dependant modulation of optic flow-processing lobula plate cells in butterflies

Increasing experimental evidence suggests that biological systems cancel predictable components of sensory signals while maintaining sensitivity to externally induced state changes. This strategy provides task-specific sensor responses for posture, locomotion, and gaze control. A prime example is found in interneurons that respond to visual image shifts resulting from the relative motion between an animal's eyes and its visual surroundings. Such optic flow-processing interneurons, found across phyla and are particularly well characterized in Dipteran and other flying insects. We studied optic flow-processing interneurons in the Monarch butterfly whose large and highly contrasted wings sweep through the visual field with every wing-beat cycle, potentially obscuring interneuron output signals. Our results show baseline spiking activity increases when animals flap their wings, and individual spikes are phase-locked to the wing-beat cycle, even in the dark, when no visual motion input is available. A qualitative estimate of the interneurons' response to directional wing motion through its receptive field is not sufficient to explain the recorded activity patterns. Our results suggest that an additional internal signal suppresses responses to wing-induced visual motion to support effective vision-based stabilization reflexes. These findings support the principle that self-generated signals are suppressed while sensitivity to external modulation is preserved.

neuroscience↗