Shengxi Wu

Background: Shank3 knockout (KO) mice recapitulate core autism spectrum disorder (ASD)-like behaviors and are widely regarded as a reliable model for autism. Although dysfunction of GABAergic neurons is closely associated with ASD-like phenotypes, it remains unclear how Shank3 deficiency leads to whole-brain structural remodeling of GABAergic neurons. Furthermore, there is currently a lack of systematic methodologies for the comprehensive statistical analysis of GABAergic neurons across the entire brain. Methods: By combining rAAV/B10-mGAD65-EGFP virus labeling with fluorescence Micro-Optical Sectioning Tomography (fMOST), we constructed a mesoscopic whole-brain atlas of GABAergic neurons in Shank3 KO mice, enabling systematic quantification of soma numbers and comprehensive morphological profiling across multiple brain regions. Results: We systematically analyzed soma counts and morphology across multiple brain regions in Shank3 KO and WT mice. Soma counts did not differ significantly between the two groups in any of the analyzed brain regions. However, morphological changes were region-specific, exhibiting increased neurite complexity in the anterior cingulate cortex (ACC) and entorhinal cortex (ENT), but reduced neurite complexity in the retrosplenial cortex (RSP). Conclusions: Viral-fMOST enables whole-brain quantification of GABAergic neurons and provides a reference for imaging other neuronal subtypes. In Shank3 KO mice, neurite changes reveal a mesoscopic map of GABAergic alterations relevant to ASD research.

Pathogenic variants in MSL2 , a core component of the histone-modifying MSL complex, are associated with neurodevelopmental disorders (NDDs) and white matter abnormalities; however, their mechanisms of pathogenicity remain unknown. In this study, we identified three patients with NDD carrying MSL2 variants, all of whom exhibited white matter abnormalities. Using conditional knockout mice, we demonstrated that oligodendrocyte lineage-specific deletion of Msl2 disrupts oligodendrocyte precursor cell proliferation, maturation, and myelination in a cell-autonomous manner, leading to autism-like behaviors including social deficits and repetitive behaviors. Integrated transcriptomic and epigenomic profiling revealed that MSL2 maintains H3K4me3 occupancy at promoters of genes essential for cell cycle progression, mitotic spindle assembly, and myelination, whereas its loss aberrantly activates immune-related pathways. Furthermore, a cell synchronization study confirmed that MSL2 is required for metaphase spindle formation in oligodendrocyte precursor cells, providing a mechanistic basis for impaired oligodendroglial development and hypomyelination. Our findings establish MSL2 as a critical epigenetic regulator of oligodendrocyte lineage progression and propose MSL2-targeted interventions as a promising therapeutic strategy for NDD-related white matter defects.

Sevoflurane is one of the most commonly used general anesthetics in pediatric clinical practice worldwide. Although accumulating preclinical evidence indicates that neonatal sevoflurane exposure causes persistent cognitive impairments, the extracellular mechanisms remain unclear. Herein, we focus on perineuronal nets (PNNs), extracellular matrix (ECM) structures that constrain neuronal excitatory plasticity and are highly enriched in the hippocampal CA2, a region critical for social recognition memory. Neonatal mice repeatedly exposed to 3% sevoflurane (2 h/day, P6‐P8) exhibited persistent CA2‐specific PNN degradation in adulthood. Mechanistically, sevoflurane depleted H3K27me3 at the Mmp9 promoter, elevating matrix metalloproteinase 9 (MMP9) expression. This epigenetic dysregulation impaired BDNF/ TrkB signaling, reduced PSD‐95 puncta density and dendritic spine abundance, and suppressed mEPSC frequency, leading to impaired novel object recognition and social discrimination. Spatial transcriptomics validated CA2‐specific ECM pathway dysregulation. Notably, CA2‐targeted Hapln1 overexpression in the CA2 excitatory neurons of Camk2a‐Cre mice effectively restored PNN integrity, rescued synaptic dysfunction, and reversed cognitive deficits. The pharmacological inhibition of MMP9 yielded comparable neuroprotective effects. Collectively, this study identified PNNs as pivotal mediators of anesthetic neurotoxicity, uncovered a previously unrecognized epigenetic‐ECM coupling mechanism driving developmental brain injury, and highlighted PNN preservation as a promising translational strategy for preventing pediatric anesthesia‐associated cognitive impairment.

Aims: The anterior cingulate cortex (ACC) is widely recognized as a key brain region in modulating itch and itch‐associated behaviors. Though neuronal mechanisms are increasingly clarified, the role of ACC astrocytes remains poorly understood. Methods: By employing a diphenylcyclopropenone (DCP)‐induced chronic itch mouse model, we assessed scratching behavior and negative emotions via behavioral tests. Astrocytic morphology was examined through immunofluorescence staining and sholl analysis. Fiber photometry was used to record calcium signals of ACC astrocytes and CaMKII‐positive neurons. Chemogenetic manipulation was applied to modulate astrocyte activity. Gliotransmitter quantification was implemented to detect the gliotransmitter release in the ACC. Results: DCP induced robust scratching responses and concomitant anxiety‐ and depression‐like behaviors. ACC astrocytes exhibited morphological activation and elevated calcium responses. Chemogenetic activation of ACC astrocytes alleviated DCP‐induced scratching behavior and negative emotions, and enhanced calcium activity of local CaMKII‐positive neurons. Conversely, chemogenetic inhibition of ACC astrocytes reduced such neuronal calcium activity. D‐serine and ATP levels were reduced in DCP‐induced chronic itch, while chemogenetic activation of astrocytes significantly elevated them. Conclusions: ACC astrocytes play a critical role in regulating chronic itch and comorbid anxiety‐depression by modulating CaMKII‐positive neuronal activity, providing a potential therapeutic target for intractable chronic itch in clinical settings.

Background: Psoriasis vulgaris (PV) and atopic dermatitis (AD) are chronic inflammatory skin diseases characterized by distinct dominant T cell subsets, yet emerging evidence suggests overlapping immune mechanisms. Whether a shared Treg abnormality underlies both diseases remains unclear. Methods: Single-cell RNA sequencing data from lesional T cells of 8 PV, 7 AD, and 7 healthy controls were analyzed. Treg subset identification, trajectory, communication, and enrichment analyses were conducted. Differentially expressed genes from both diseases were intersected and subjected to Mendelian randomization to screen for shared causal genes, followed by interaction mapping, drug prediction, and molecular docking. Findings were validated in Foxp3-tdTomato reporter mouse models of imiquimod-induced psoriasis-like and MC903-induced AD-like dermatitis by flow cytometry and quantitative PCR. Results: A shared Treg triad remodeling pattern was identified: central memory Treg (cmTreg) was almost completely depleted, cycling Treg (Treg-c) expanded, and effector Treg (eTreg) accumulated in both diseases. Pseudotemporal analysis revealed a differentiation coordination defect, with upstream Treg-c shifting prematurely while effector Treg failed terminal maturation. Cell communication analysis identified enhanced MIF-(CD74+CXCR4/CD44) signaling as a shared intercellular remodeling axis, with the network shifting from a cmTreg-centric topology to one jointly centered on Treg-c and eTreg. Mendelian randomization identified seven shared causal genes (PDCD5, PHF19, GNAQ, LRR1, DHX36, TMEM107, FAM200B), with PHF19 serving as a core accessory subunit of PRC2. Molecular docking and in vivo experiments demonstrated that resveratrol binds PHF19, is predicted to activate the PHF19-PRC2-H3K27me3 axis, restores Treg subset homeostasis, and ameliorates skin lesions in both models. Conclusions: Treg subset remodeling is a shared pathogenic feature, nominating PHF19-targeted activation as a tolerance-restoring therapeutic strategy.

Background/Objectives: Autism spectrum disorder (ASD) is a group of developmental disorders featured by social dysfunction, for which there still lacks effective treatments. Our previous study demonstrated that XAV939, a tankyrase inhibitor, could alleviate social dysfunction in two ASD mouse models via suppressing Wnt and glycolytic signaling. However, its further application is limited by poor brain–blood barrier penetration and low bioavailability. Methods: XAV939 was structurally optimized by esterification. The effects of XAV939-derivatives on Wnt/glycolysis were assessed by Western blotting, Topflash luciferase assay, lactate levels and the extracellular acidification rate. Social behaviors were evaluated by a three-chamber test, a resident–intruder test and ultrasonic vocalization. Biomimetic brain targeting was achieved by neuron-astrocyte hybrid cell membrane encapsulation. Periphery toxicities were examined by biochemical and histological analysis. Results: Three esterified XAV939 were synthesized. Data from both 293FT cells and primary Shank3b^-/- neurons revealed that an alkyl ester prodrug of XAV939 (named XAV939-L1) exhibited dual inhibition of Wnt/glycolysis. Intravenous injection of XAV939-L1 effectively improved the social function of Shank3b^-/- mice but showed hepatic side effects. Further, we made brain-targeting XAV939-L1 (XAV939-L1-BT) by neuron–astrocyte hybrid cell membrane encapsulation, which greatly enhanced the accumulation of XAV939-L1-BT in the brain and reduced its distribution in peripheral tissues (liver and intestine). At a half-dose of XAV939-L1, XAV939-L1-BT exhibited significant social improvement effects without obvious hepatic and intestinal toxicity. Conclusions: Our data demonstrated an esterified XAV939 and its biomimetic brain-targeted formula as a potential drug candidate for treating ASD-associated social dysfunction.

Autism spectrum disorder (ASD) is characterized by core deficits in social behavior, yet effective interventions remain limited. Ketogenic diet (KD) shows behavioral benefits in ASD, but the underlying mechanisms remain unclear. Here, using Shank3B knockout (KO) mice, we found that KD ameliorates social deficits and induces systemic ketosis with marked elevation of β-hydroxybutyrate (BHB) in KO mice. Oral BHB alone recapitulates KD’s prosocial effects, restoring social interaction and neuronal activity in the anterior cingulate cortex (ACC). Mechanistically, we identified HDAC9 as a region- specific epigenetic target upregulated in ACC neurons of Shank3B KO mice and suppressed by BHB. HDAC9 overexpression in ACC neurons induces social and synaptic deficits, while class IIa HDAC inhibition phenocopies BHB effects. BHB also restores dendritic complexity, excitatory transmission, and AMPA receptor expression. These findings uncover a metabolite-driven epigenetic mechanism linking ketogenic metabolism to the rescue of social behavior via the ACC, and identify HDAC9 as a potential therapeutic target for ASD-related social deficits.

Olfaction is crucial for rodent social behavior, and olfactory dysfunction has been observed in multiple autism spectrum disorder (ASD) models, but its phenotype in Shank3^⁻/⁻ mice (a classic ASD model) remains unclear. We systematically assessed olfactory function in Shank3^⁻/⁻ mice by using a modified olfactory three-chamber test and optimized ultrasonic vocalization (USV) detection in combination with resting-state functional magnetic resonance imaging (rs-fMRI), whole-brain c-Fos mapping, and three-dimensional (3D) behavioral analysis. Our results showed abnormal odor preference and hyperconnectivity in olfaction-associated brain networks. Upon exposure to neutral, appetitive, and social pheromone odors, Shank3^⁻/⁻ mice displayed atypical whole-brain c-Fos activation patterns, which were coupled with synchronized locomotor suppression and stereotyped behaviors. This study maps the neural-behavioral responses to odors in Shank3^-/- mice, linking olfactory deficits to autism-like behaviors, and highlights the olfactory system as a targetable pathway for sensory-based autism therapies.

Defensive responses are evolutionarily conserved adaptive behaviors that species exhibit in response to threats to protect themselves from harm or death. The selection of context-appropriate defensive strategies, particularly the transition between freezing and flight behaviors, constitutes a critical determinant of species survival. We first established a two pure tone serial-compound stimulus (TTSCS) paradigm to evaluate the dynamic transition of defensive behaviors evoked by conditioned stimuli. This paradigm minimizes potential confounding effects on defensive behavior caused by differences in tone. Using this approach, we found that as the threat stimulus approached more closely, mice exhibited increased escape behaviors characterized by shorter latencies and larger magnitudes of response. These behavioral changes were associated with the dynamic responses of dopamine receptor 1 expressing MSNs (D1 MSNs) and dopamine receptor 2 expressing MSNs (D2 MSNs) in the dorsomedial striatum (DMS). Following functional validation through manipulation of the PFC (prefrontal cortex)–DMS circuit, we found that activating the PFC-DMS ^D1 pathway significantly shortened the response latency of mice to heightened threat stimuli, enabling faster defensive reactions. However, activation of D2 MSNs subtypes of PFC-DMS pathway resulted in no significant alterations in the defensive behaviors. In conclusion, D1and D2 MSNs in the DMS likely act in an antagonistic manner to regulate defensive behaviors, and furthermore, the PFC projection specifically to the direct pathway within the DMS mediates the shift in defensive responses to an approaching threat.