Choi, C. S. | bioRxiv Science

bioRxiv2025

Integrative Analysis of Proteomics and Metabolomics Reveals Impacts of Sam2 Knockout on Autism Spectrum Disorders

Neurokine Sam2 deficiency is associated with behavioral abnormalities including heightened anxiety and fear responses across evolutionarily conserved model organisms. Here, we employed an integrated proteomics and metabolomics approach using liquid chromatography-mass spectrometry (LC-MS) to elucidate molecular signatures associated with autism spectrum disorder (ASD) in Sam2 knockout mice. Comparative analysis of blood plasma samples from Sam2 knockout and wild-type mice revealed substantial alterations in both proteomic and metabolomic profiles. Proteomic analysis identified 68 differentially expressed proteins (comprising 102 peptides), with notable upregulation of complement component C1qc and downregulation of apolipoprotein A1 (Apoa1), implicating dysregulation of complement cascade pathways. Metabolomic profiling uncovered 15 significantly altered metabolites: nine upregulated species including D-glucuronic acid and 5,10-Methylenetetrahydrofolate, and six downregulated metabolites including folinic acid and acetate. Integrative pathway analysis revealed perturbations in glycolysis/gluconeogenesis and glycerophospholipid metabolism, providing mechanistic insights into the molecular consequences of Sam2 deficiency. These findings identify potential biomarkers for anxiety-related disorders and ASD while advancing our understanding of the complex interplay between genetic alterations and proteomic-metabolomic networks in neurodevelopmental conditions. Our results establish a foundation for developing targeted therapeutic interventions and highlight the utility of multi-omics approaches in dissecting the molecular basis of behavioral disorders.

systems biology↗

bioRxiv2025

Safe focused ultrasound-mediated blood-brain barrier opening is driven primarily by transient reorganization of tight junctions

Focused ultrasound (FUS) with microbubbles opens the blood-brain barrier (BBB) to allow targeted drug delivery into the brain. The mechanisms by which endothelial cells (ECs) respond to either low acoustic pressures known to open the BBB transiently, or high acoustic pressures that cause brain damage, remain incompletely characterized. Here, we use a mouse strain where tight junctions between ECs are labelled with eGFP and apply FUS at low (450 kPa) and high (750 kPa) acoustic pressures, after which mice are sacrificed at 1 or 72 hours. We find that the EC response leading to FUS-mediated BBB opening at low pressures is localized primarily in arterioles and capillaries, and characterized by a transient loss and reorganization of tight junctions. BBB opening still occurs at low safe pressures in mice lacking caveolae, suggesting that it is driven primarily by transient dismantlement and reorganization of tight junctions. In contrast, BBB opening at high pressures is associated with obliteration of EC tight junctions that remain unrepaired even after 72 hours, allowing continuous fibrinogen passage and persistent microglial activation. Single-cell RNA-sequencing of arteriole, capillary and venule ECs from FUS mice reveals that the transcriptomic responses of ECs exposed to high pressure are dominated by genes belonging to the stress response and cell junction disassembly at both 1 and 72 hours, while lower pressures induce primarily genes responsible for intracellular repair responses in ECs. Our findings suggest that at low pressures transient reorganization of tight junctions and repair responses mediate safe BBB opening for therapeutic delivery. Significance StatementFocused ultrasound with microbubbles is used as a noninvasive method to safely open the BBB at low acoustic pressures for therapeutic delivery into the CNS, but the mechanisms mediating this process remain unclear. Kugelman et al., demonstrate that FUS-mediated BBB opening at low pressures occurs primarily in arterioles and capillaries due to transient reorganization of tight junctions. BBB opening still occurs at low safe pressures in mice lacking caveolae, suggesting a transcellular route-independent mechanism. At high unsafe pressures, cell junctions are obliterated and remain unrepaired even after 72 hours, allowing fibrinogen passage and persistent microglial activation. Single-cell RNA-sequencing supports cell biological findings that safe, FUS-mediated BBB opening may be driven by transient reorganization and repair of EC tight junctions.

bioengineering↗