Neurovascular coupling (NVC) is important for brain function and its dysfunction underlies many neuropathologies. Although cell-type specificity has been implicated in NVC, how active neural information is conveyed to the targeted arterioles in the brain remains poorly understood. Here, using two-photon focal optogenetics in the mouse cerebral cortex, we demonstrate that single glutamatergic axons dilate their innervating arterioles via synaptic-like transmission between neural-arteriolar smooth muscle cell junctions (NsMJs).
View Article and Find Full Text PDFAchieving uniform optical resolution for a large tissue sample is a major challenge for deep imaging. For conventional tissue clearing methods, loss of resolution and quality in deep regions is inevitable due to limited transparency. Here we describe the Transparent Embedding Solvent System (TESOS) method, which combines tissue clearing, transparent embedding, sectioning and block-face imaging.
View Article and Find Full Text PDFAstrocytes are the largest glial population in the mammalian brain. However, we have a minimal understanding of astrocyte development, especially fate specification in different regions of the brain. Through lineage tracing of the progenitors of the third ventricle (3V) wall via in-utero electroporation in the embryonic mouse brain, we show the fate specification and migration pattern of astrocytes derived from radial glia along the 3V wall.
View Article and Find Full Text PDFSingle-cell omics is critical in revealing population heterogeneity, discovering unique features of individual cells, and identifying minority subpopulations of interest. As one of the major post-translational modifications, protein -glycosylation plays crucial roles in various important biological processes. Elucidation of the variation in -glycosylation patterns at single-cell resolution may largely facilitate the understanding of their key roles in the tumor microenvironment and immune therapy.
View Article and Find Full Text PDFCerebral cavernous malformations (CCMs) and spinal cord cavernous malformations (SCCMs) are common vascular abnormalities of the CNS that can lead to seizure, haemorrhage and other neurological deficits. Approximately 85% of patients present with sporadic (versus congenital) CCMs. Somatic mutations in MAP3K3 and PIK3CA were recently reported in patients with sporadic CCM, yet it remains unknown whether MAP3K3 mutation is sufficient to induce CCMs.
View Article and Find Full Text PDFMicroglia continuously survey the brain parenchyma and actively shift status following stimulation. These processes demand a unique bioenergetic programme; however, little is known about the metabolic determinants in microglia. By mining large datasets and generating transgenic tools, here we show that hexokinase 2 (HK2), the most active isozyme associated with mitochondrial membrane, is selectively expressed in microglia in the brain.
View Article and Find Full Text PDFDifferent segments of the cerebral vascular network may react distinctly to brain ischemia and recanalization. However, there are limited systematic observations of these vascular responses in mice under a physiological state following ischemic stroke. Herein, we aimed to investigate the vasodynamics among several segments along the cerebral vessels in awake mice following cerebral ischemia/recanalization via two-photon imaging.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 2022
Although a wide variety of genetic tools has been developed to study learning and memory, the molecular basis of memory encoding remains incompletely understood. Here, we undertook an unbiased approach to identify novel genes critical for memory encoding. From a large-scale, in vivo mutagenesis screen using contextual fear conditioning, we isolated in mice a mutant, named , with spatial learning deficits.
View Article and Find Full Text PDFUbiquitin-binding domains (UBDs) are modular elements that bind non-covalently to the ubiquitin and ubiquitin chains. The preferences of UBDs for ubiquitin chains of specific length and linkage are central to their functions. We demonstrated that an artificial tandem hybrid UBD (ThUBD) exhibits an unbiased high affinity to all ubiquitin chains and is a promising tool for global ubiquitination profiling research.
View Article and Find Full Text PDFPrecise embolism control in immature brains can facilitate mechanistic studies of brain damage and repair after perinatal arterial ischemic stroke (PAIS), but it remains a technical challenge. Microhemorrhagic transformation is observed in one-third of infant patients who have suffered PAIS, but the underlying mechanism remains elusive. Building on an established approach that uses magnetic nanoparticles to induce PAIS, we develop a more advanced approach that utilizes magnetized erythrocytes to precisely manipulate de novo and in situ embolus formation and reperfusion in perinatal rodent brains.
View Article and Find Full Text PDFThe vegetative state (VS) and minimally conscious state (MCS) are two major types of chronic disorders of consciousness (DoC). The assessment of these two consciousness states generally relies on the Coma Recovery Scale-Revised (CRS-R) score, but a high misdiagnosis rate limits the generalized use of this score. To identify metabolites in human plasma that can accurately distinguish VS from MCS patients, comprehensive plasma metabolic profiles were obtained with targeted metabolomics analysis and untargeted and targeted lipidomics analysis.
View Article and Find Full Text PDFNicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme in the NAD salvage pathway. Our previous study demonstrated that deletion of NAMPT gene in projection neurons using Thy1-NAMPT conditional knockout (cKO) mice causes neuronal degeneration, muscle atrophy, neuromuscular junction abnormalities, paralysis and eventually death. Here we conducted a combined metabolomic and transcriptional profiling study in an attempt to further investigate the mechanism of neuronal degeneration at metabolite and mRNA levels after NAMPT deletion.
View Article and Find Full Text PDFBackground: Glioblastoma (GBM) are highly heterogeneous on the cellular and molecular basis. It has been proposed that glutamine metabolism of primary cells established from human tumors discriminates aggressive mesenchymal GBM subtype to other subtypes.
Methods: To study glutamine metabolism in vivo, we used a human orthotopic mouse model for GBM.
Teeth are attached to alveolar bone by the periodontal ligament (PDL), which contains stem cells supporting tissue turnover. Here, we identified Gli1+ cells in adult mouse molar PDL as multi-potential stem cells (PDLSCs) giving rise to PDL, alveolar bone, and cementum. They support periodontium tissue turnover and injury repair.
View Article and Find Full Text PDFUnderstanding tumor metabolism holds the promise of new insights into cancer biology, diagnosis and treatment. To assess human cancer metabolism, here we report a method to collect intra-operative samples of blood from an artery directly upstream and a vein directly downstream of a brain tumor, as well as samples from dorsal pedal veins of the same patients. After performing targeted metabolomic analysis, we characterize the metabolites consumed and produced by gliomas in vivo by comparing the arterial supply and venous drainage.
View Article and Find Full Text PDFModeling the processes of neuronal progenitor proliferation and differentiation to produce mature cortical neuron subtypes is essential for the study of human brain development and the search for potential cell therapies. We demonstrated a novel paradigm for the generation of vascularized organoids (vOrganoids) consisting of typical human cortical cell types and a vascular structure for over 200 days as a vascularized and functional brain organoid model. The observation of spontaneous excitatory postsynaptic currents (sEPSCs), spontaneous inhibitory postsynaptic currents (sIPSCs), and bidirectional electrical transmission indicated the presence of chemical and electrical synapses in vOrganoids.
View Article and Find Full Text PDFEmerging evidence suggests that crosstalk between glioma cells and the brain microenvironment may influence brain tumor growth. To date, known reciprocal interactions among these cells have been limited to the release of paracrine factors. Combining a genetic strategy with longitudinal live imaging, we find that individual gliomas communicate with distinct sets of non-glioma cells, including glial cells, neurons, and vascular cells.
View Article and Find Full Text PDFMetformin is currently the most effective treatment for type-2 diabetes. The beneficial actions of metformin have been found even beyond diabetes management and it has been considered as one of the most promising drugs that could potentially slow down aging. Surprisingly, the effect of metformin on brain function and metabolism has been less explored given that brain almost exclusively uses glucose as substrate for energy metabolism.
View Article and Find Full Text PDFTraditional two-dimensional histological sections and microcomputed tomography remain to be the major tools for studying craniofacial bones despite the complicated spatial organization of craniofacial organs. Recently, our laboratory developed the Poly(Ethylene Glycol) Associated Solvent System (PEGASOS) tissue clearing method, which can efficiently render hard tissues, including bones and teeth fully transparent without losing endogenous fluorescent signals. Complete tissue transparency enables us to acquire three-dimensional (3D) images of craniofacial bone vasculature, osteogenesis utilizing various labeling strategies, thus to investigate the spatial relationship among different tissues during postnatal craniofacial development.
View Article and Find Full Text PDFOwing to the diversity of cancer types and the spatiotemporal heterogeneity of tumour signals, high-resolution imaging of occult malignancy is challenging. F-fluorodeoxyglucose positron emission tomography allows for near-universal cancer detection, yet in many clinical scenarios it is hampered by false positives. Here, we report a method for the amplification of imaging contrast in tumours via the temporal integration of the imaging signals triggered by tumour acidosis.
View Article and Find Full Text PDFIn the initial published version of this article, there was an error in the "MATERIALS AND METHODS" section. The catalog number of PEGMMA500 for preparing tB-PEG dehydration solution and BB-PEG clearing medium was listed as Sigma-Aldrich 409529. The correct catalog number should be Sigma-Aldrich 447943.
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