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Xu, S.-J.

Publications and source records attributed to Xu, S.-J..

4 recordsLinked to original sources

Microglia Piezo1 aggravates cerebral ischemia and reperfusion injury by chemotactic recruitment of T lymphocytes

Cerebral ischemia reperfusion injury (CIRI) is a complex pathophysiological process involving multiple mechanisms. Piezo1, a stretch-activated ion channel, has recently emerged as a potential regulator of cellular responses to ischemic conditions. However, its role in specific cells during ischemic events is not well elucidated. Here, we showed that after experimentally induced CIRI, Piezo1 channel was highly expressed in peri-infarct area, where is upregulated and activated mainly in microglia. Behavioral tests, and infarct volume measurements demonstrated that conditional Piezo1 deficient in microglia markedly ameliorated the neurological deficits and reduced the infarct volumes. Flow cytometry and immunofluorescence staining showed decreased peripheral immune cells, especially T lymphocytes infiltration into the brain in microglia Piezo1 deficient mice after stroke. Multiplex chemokine immunoassay and T cell migration assays screened that Piezo1 deficient microglia blocked the CXC chemokine ligand 10 (CXCL10) release from astrocyte, which lead to the inhibited T cell recruitment in transwell co-cultured system. Furthermore, RNA-Sequencing analysis showed that defective Piezo1 in microglia lead to its polarization towards an anti-inflammatory phenotype in response to cerebral ischemia and reduced the secretion of tumor necrosis factor- (TNF-) and interferon-{gamma} (IFN-{gamma}). Collectively, Piezo1 deficiency inhibited the secretion of TNF- and IFN-{gamma} in microglia. The reduction of these inflammatory cytokines further blocked the CXCL10 release from astrocyte, and ultimately ameliorated the infiltration of peripheral T lymphocytes after stroke. Our results therefore highlight the critical role of Piezo1 in microglia-orchestrated neuroinflammation and suggest a potential means for reducing stroke-induced neurological injury.

neuroscience↗

BrAVe: a unified framework for 3D interactive and integrative analysis of cross-modal multi-scale brain atlas data in diverse species

Understanding the brain requires integrating molecular, structural, and functional information across multiple scales. Despite the rapid expansion of multimodal, multiscale brain atlases in various species, integrative analysis remains challenging. Here, we present iBrAVE, an open-source platform for 3D interactive, integrative analysis of brain atlas datasets across modalities and scales within a common reference space. iBrAVE unifies heterogeneous datasets into five core representations, enabling source-independent analyses from insects to primates. At the single-modality level, it features spatially resolved quantification, as exemplified by single-neuron morphology analyses spanning geometry, topology, projection, clustering, and putative wiring. Across modalities, it links gene expression and neuronal activity with morphologically defined neurons and putative circuits via establishing spatial correspondence. Across scales, it enables bidirectional inference of neuronal identity and synaptic connectivity between light- and electron-microscopy reconstructions via neuronal morphology matching. Thus, iBrAVE provides a unified framework for integrative brain atlas analyses, facilitating data-driven discovery in neuroscience.

neuroscience↗

Set2-mediated alternative splicing of Srsf11 regulates cocaine reward behavior

Alternative splicing is a key mechanism for neuronal gene regulation, and is grossly altered in mouse brain reward regions following investigator-administered cocaine. It is well established that cocaine epigenetically regulates transcription, yet mechanism(s) by which cocaine-induced epigenetic modifications regulate alternative splicing is largely unexplored. Our group and others have previously identified the histone modification, H3K36me3, as a putative splicing regulator. However, it has not yet been possible to establish the direct causal relevance of this modification to alternative splicing in brain or any other context. We found that mouse cocaine self-administration caused widespread alternative splicing, concomitant with enrichment of H3K36me3 at splice junctions. Differentially spliced genes were enriched in the motif for splice factor, Srsf11, which was both differentially spliced and enriched in H3K36me3. Epigenetic editing led us to conclude that H3K36me3 functions directly in alternative splicing of Srsf11, and that Set2 mediated H3K36me3 bidirectionally regulates cocaine intake.

neuroscience↗

MicroRNA-122 supports robust innate immunity in hepatocytes by suppressing STAT3 phosphorylation

The intrinsic innate immunity of hepatocytes is essential for the control of hepatitis viruses and influences the outcome of antiviral therapy. MicroRNA-122 (miR-122) is the most abundant microRNA in hepatocytes and is a central player in liver biology and disease. However, little is known about the role of miR-122 in hepatocyte innate immunity. Herein, we show that restoring miR-122 levels in hepatoma cells markedly increased the activation of both type III and type I interferons (IFNs) in response to hepatitis C virus (HCV) RNA or poly(I:C). We determined that miR-122 promotes IFN production through down-regulating the tyrosine (Tyr705) phosphorylation of STAT3. We show that STAT3 represses IFN activation by inhibiting interferon regulatory factor 1 (IRF1), which is rate-limiting for maximal IFN expression, especially type III IFNs. Through large-scale screening, we identified that miR-122 targets MERTK, FGFR1 and IGF1R, three oncogenic receptor tyrosine kinases that directly promote STAT3 phosphorylation. These findings reveal a previously unknown role for miR-122 in hepatic immunity and indicate a new potential strategy for treating hepatic infections through targeting STAT3.

molecular biology↗