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Biology subjects

Ge, W.-p.

Publications and source records attributed to Ge, W.-p..

10 recordsLinked to original sources

Characterizing the metabolomes of microglia, astrocytes, and neurons in aging and Alzheimer's brains

Neurons and glia are distinct in their morphology, development, and function, possessing unique transcriptomes and proteomes, but little is known about their metabolomes. The challenge of brain cell metabolic profiling is to obtain a large number of cells for reliable analysis. Here, we purified microglia, astrocytes, and neurons from mouse brains, identifying >70 metabolites through targeted metabolomics and 9,854 metabolite features via untargeted metabolomics. We systematically characterized cell type-enriched metabolites and metabolic pathways, revealing an enrichment of glutathione (GSH) and polyamine metabolism in microglia. This enrichment was validated in vivo and showed significant decreases with aging and in an Alzheimers disease (AD) model. Notably, GSH and polyamine metabolism correlated strongly with chemokine-related gene expression. Disrupting the GSH pathway in microglia resulted in downregulation of chemokine-related genes, aberrant morphogenesis, and {beta}-amyloid deposition. Our results provide a valuable resource (https://metabolismocean.org/braincell) for metabolic studies related to aging, AD, and other neurological diseases.

neuroscience↗

OpenFISH enables integrated high-resolution spatial transcriptomics and metabolomics on a single tissue section

Spatial transcriptomics enables in situ mapping of gene expression, yet no current platform provides single-cell, same-section integration with metabolomics, limiting direct links between transcriptional programsand metabolic phenotypesin native tissue. We present OpenFISH, a rapid, imaging-based spatial transcriptomics method operable on standard microscopes, requiring no proprietary hardware, and fully compatible with matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). OpenFISH resolves hundreds of transcripts at subcellular resolution within 24 h and can be performed after MALDI-MSI, preserving metabolite distributions for cell-accurate co-registration on the same section. In mouse brain, integration with MALDI-MSI resolved metabolic heterogeneity at the level of individual cells. OpenFISH also quantified cell type-specific transcriptional activation of transposable elements after systemic lipopolysaccharide (LPS) challenge and detected disrupted spatial organization of D1 striatal neurons in Reeler mutants. Benchmarking showed performance comparable to or exceeding commercial platforms at [~]0.5% of per-sample cost. By enabling same-section, near-single-cell co-mapping of transcripts and metabolites in an accessible workflow, OpenFISH provides a scalable framework for high-content spatial multi-omics across neuroscience, immunology, cancer biology, and beyond.

molecular biology↗

rAAV-miniBEND: A targeted vector for brain endothelial cell gene delivery and cerebrovascular malformation modeling

Defects in brain endothelial cells (brainECs) can cause severe cerebrovascular malformations, including arteriovenous malformation (AVM) and cerebral cavernous malformation (CCM). The lack of appropriate tools for cerebrovascular disease modeling and local genetic manipulation of the brain vasculature hinders research on cerebrovascular malformations. Here we develop a recombinant adeno-associated virus (rAAV) tool miniBEND (rAAV-based mini-system for brain endothelial cells, rAAV-miniBEND), which combines a minimal promoter and an optimized cis-acting element (cis-element) isolated from the mouse gene Tek. This system achieves gene expression specifically in mouse and rat brainECs. Using rAAV-miniBEND, we achieve high-efficiency and high-specificity gene expression in brainECs through intracranial injection at various developmental stages and through intravenous administration at all postnatal stages in mice. Furthermore, we use rAAV-miniBEND to model sporadic CCMs mediated by MAP3K3I441M and AVMs mediated by BrafV600E. We demonstrate that somatic expression of BrafV600E in brainECs induces an AVM phenotype, and that brainEC proliferation are important for AVM development. Thus, our rAAV-miniBEND system provides a valuable and widely applicable tool for cerebrovascular disease modeling and local or global brainEC gene delivery.

neuroscience↗

Cisternostomy facilitates clearance of metabolic waste from cerebrospinal fluid in patients with traumatic brain injury

Decompressive craniotomy, a common intervention for traumatic brain injury (TBI), can fail to effectively alleviate patient symptoms. Cisternostomy, reported for cistern drainage in TBI patients, has shown efficacy in reducing intracranial pressure and clearing detritus resulting from brain hemorrhage. However, the mechanisms underlying its effectiveness remain largely unknown. Here, we utilized non-targeted metabolomics to analyze cerebrospinal fluid from cisterns alongside peripheral blood samples from TBI patients undergoing cisternostomy. Through a systematic comparison of the cisternal cerebrospinal fluid and blood plasma metabolomes, we identified multiple blood-enriched metabolites, including betaine, triethanolamine, and proline, that were efficiently cleared during the acute stage of TBI. Notably, two metabolites linked to arginine metabolism and the urea cycle, N8-acetylspermidine and N-acetylputrescine, showed significant reductions that correlated with improvements in the Glasgow Coma Scale. Our findings indicate that cisternostomy effectively removes blood-derived substances and aids the recovery of patients with acute-stage TBI.

neuroscience↗

Curved light sheet microscopy for centimeter-scale cleared tissues imaging

Imaging large cleared tissues requires scaling the throughput of imaging techniques. Here we introduce curved light sheet microscope to perform optical sectioning with curved light sheets. This concept addresses the long-standing field curvature problem and lowers the barriers in designing high-throughput objectives. Leveraging a customized objective, the curved light sheet microscope achieves diffraction-limited resolution (1.0 m laterally and 2.5 m axially) and uniform contrast over a field of view of more than 1 x 1 cm2 and is compatible with various tissue clearing techniques. Imaging an entire intact cleared mouse brain at 0.625 x 0.625 x 1.25 m3 voxel size takes less than 3 hours and image tiling is not required. We share full optics description of the objective and report imaging neuronal and vascular networks and tracing brain-wide long-distance axonal projections in intact mouse brains.

bioengineering↗

The subcommissural organ regulates brain development via secreted peptides

The subcommissural organ (SCO) is a gland located at the entrance of the aqueduct of Sylvius in the brain. It exists in species as distantly related as amphioxus and humans, but its function is largely unknown. To explore its function, we compared transcriptomes of SCO and non-SCO brain regions and found three genes, Sspo, Car3, and Spdef, that are highly expressed in the SCO. Mouse strains expressing Cre recombinase from endogenous promoter/enhancer elements of these genes were used to genetically ablate SCO cells during embryonic development, resulting in severe hydrocephalus and defects in neuronal migration and development of neuronal axons and dendrites. Unbiased peptidomic analysis revealed enrichment of three SCO-derived peptides, namely thymosin beta 4, thymosin beta 10, and NP24, and their reintroduction into SCO-ablated brain ventricles substantially rescued developmental defects. Together, these data identify a critical role for the SCO in brain development.

neuroscience↗

ADAM10 mediates macroglial cell fate decisions in the developing brain

ADAMs (a disintegrin and metalloproteinase) are transmembrane proteins with cell adhesion and protease activities that contain disintegrin and metalloproteinase domains. ADAM10, a member of the ADAM family, is widely expressed in the brain. There are >40 substrates reported for ADAM10, including Notch, Delta-like ligand-1 (Dll1), and N-cadherin. To date, however, its function in the brain has been largely unknown. We used genetic manipulation to delete Adam10 specifically from glial progenitors in developing brains and observed that conditional knockout mice showed locomotor abnormalities. They all died within 4 months with apparent defects in the cerebellum. By comprehensively analyzing data from bulk RNA sequencing, single-cell RNA sequencing, and staining of the cerebellum, we found that ADAM10 promoted astrocyte generation under physiological conditions. Upon the removal of Adam10 in glial progenitors, the production of oligodendrocytes vastly increased, whereas the generation of astrocytes was substantially inhibited. Our results showed that ADAM10 plays a critical role in macroglial cell fate decisions during brain development.

neuroscience↗

Mapping of individual sensory nerve axons from digits to spinal cord with the Transparent Embedding Solvent System

Understanding the connections and projections of neurons has been a fundamental issue for neuroscience. Although strategies have been developed to map the projection of individual axons within the mouse brain, high resolution mapping of individual peripheral nerve axons in peripheral organs or spinal cord has never been achieved. Here, we designed the Transparent Embedding Solvent System (TESOS) method and developed a technical pipeline for imaging, reconstructing and analyzing large samples containing various tissue types at sub-micron resolution. The mouse whole body was reconstructed at micron-scale resolution. We were able to image, reconstruct and analyze the complete axonal projection of individual sensory neurons within an intact mouse paw or spinal cord at sub-micron resolution. Furtherly, we imaged and reconstructed the entire projection course of individual sensory neurons from adult mouse digits to the spinal cord. The TESOS method provides an efficient tool for micron-scale connectome mapping of the peripheral nervous system.

neuroscience↗

Precision mapping of the mouse brain metabolome

Metabolism is physiologically fundamental to a biological system. Understanding brain metabolism is critical for our comprehensive knowledge of brain function in health and disease. Combining a microarray collection system with targeted metabolomics analysis, here we performed precision mapping of the metabolome in the mouse brain and created maps for 79 metabolites with a resolution of 0.125mm3 per pixel (i.e., brain subregion). The metabolome atlas provides researchers with a useful resource to interpret the vulnerability of specific brain regions to various disease-relevant metabolic perturbations.

neuroscience↗

Reduction of neuronal activity mediated by blood-vessel regression in the brain

The brain vasculature supplies neurons with glucose and oxygen, but little is known about how vascular plasticity contributes to brain function. Using longitudinal in vivo imaging, we reported that a substantial proportion of blood vessels in the adult brain sporadically occluded and regressed. Their regression proceeded through sequential stages of blood-flow occlusion, endothelial cell collapse, relocation or loss of pericytes, and retraction of glial endfeet. Regressing vessels were found to be widespread in mouse, monkey and human brains. Both brief occlusions of the middle cerebral artery and lipopolysaccharide-mediated inflammation induced an increase of vessel regression. Blockage of leukocyte adhesion to endothelial cells alleviated LPS-induced vessel regression. We further revealed that blood vessel regression caused a reduction of neuronal activity due to a dysfunction in mitochondrial metabolism and glutamate production. Our results elucidate the mechanism of vessel regression and its role in neuronal function in the adult brain.

neuroscience↗