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Biomedical subjects

Xiaoyu Zhu

Publications and source records attributed to Xiaoyu Zhu.

3 recordsLinked to original sources

Hex-MASP for mapping the whole-tissue spatial proteome and the intrabrain distribution of monoclonal antibodies.

Whole-tissue level spatial proteomics provides critical insights into region-specific biological regulations but remains challenging. Previously, we introduced the micro-scaffold assisted spatial proteomics (MASP) concept for whole-tissue mapping. However, this prototype required substantial development in spatial resolution, practicality, and throughput for practical application. Here we present a next-generation MASP technique (hex-MASP) featuring i) a new design of hexagonal-micro-wells fabricated with optimized projection micro-stereolithography 3D-printing, achieving high spatial resolution, sampling robustness, and mechanical strength for reproducibly compartmentalizing even tough tissues; ii) enhanced throughput/effectiveness in sample preparation and LC-MS analysis with high quantitative quality. Applied to mouse brain, hex-MASP achieved in-depth, whole-tissue mapping for >6,000 proteins in mouse brains, with high spatial accuracy and excellent data quality. The substantially improved resolution revealed critical regional details across the entire brain, that were not previously captured, enabling precise depiction of protein distribution heterogeneity. This technique enabled the identification of many unreported regionally enriched proteins across brain structures. We further applied hex-MASP to investigate the intrabrain distribution of intracerebroventricularly dosed antibody therapeutics and related proteins, which enabled whole-tissue mapping of protein drugs revealed insights into antibody brain penetration and distribution. Hex-MASP represents a robust, scalable platform for whole-tissue spatial proteomics.

Animals

Environmentally relevant concentrations of DCOIT impaired lifespan and healthspan in Caenorhabditis elegans.

DCOIT (4,5-dichloro-2-n-octyl-4-isothiazolin-3-one) is an antifouling biocide widely used as an alternative to organotin compounds. While previous studies had focused on its effects on energy production, endocrine disruption, and lipid metabolism, its impact on aging and underlying mechanisms remained unclear. Here, we demonstrated that environmentally relevant concentrations of DCOIT (37, 370 and 3700 ng/L) significantly impaired both lifespan and healthspan in Caenorhabditis elegans. RNA-seq and validation assays revealed that DCOIT upregulated comt-4, a key gene in dopamine metabolism, leading to dopamine depletion and subsequent induction of oxidative stress. This redox imbalance critically contributed to accelerated aging phenotypes. Importantly, both genetic (comt-4 RNAi) and pharmacological (opicapone) interventions restored dopamine levels, alleviated oxidative stress, and reversed DCOIT-induced aging deficits. Our study established the comt-4/dopamine/oxidative stress axis as a central mechanism in DCOIT toxicity, suggesting dopamine modulation as a potential countermeasure against environmental toxicant-induced aging.

Animals

Multicompartment Quantitative Proteomics Revealing Potential Mechanisms Underlying the Treatment Effects of Mesenchymal-Derived Extracellular Vesicles in a Monkey Model of Cortical Injury.

Previous studies have demonstrated that mesenchymal stromal cell-derived extracellular vesicles (MSC-EVs) enhance functional recovery after cortical injury in rhesus monkeys by reducing chronic microglial inflammation, neuronal damage, and myelination deficits. However, the signaling pathways underlying these therapeutic effects remain largely unexplored. In this study, employing a reliable quantitative proteomics platform UHR-IonStar, we identified the protein cargo of MSC-EVs infused intravenously to rhesus monkeys 24 h and 2 weeks post-injury to the motor cortex. We then analyzed global protein expression changes across cerebrospinal fluid (CSF), plasma, and brain tissue of MSC-EV-treated versus vehicle-treated female, aged rhesus monkeys. A total of 1241/431/4124 monkey proteins were reliably quantified in CSF/plasma/tissue samples, respectively. Longitudinal analysis of CSF and plasma samples highlighted a shift from MSC-EV modulation of inflammatory and metabolic proteins in plasma at early recovery (2 weeks), toward modulation of plasticity-related proteins in CSF and brain tissue at later stages (4 weeks). Further protein-protein interaction analysis identified potential MSC-EV targets related to complementary signaling, proteolysis, and aminoglycan stability, which aligned with our previous findings. This comprehensive, multicompartment monkey proteomics study advances understanding of MSC-EV contents and treatment effects, paving the way for novel treatment of cortical injury.

Animals