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Biology subjects

Xin, W.

Publications and source records attributed to Xin, W..

12 recordsLinked to original sources

Base-mismatched crRNA in CRISPR Enabled Universal One-pot Rapid Nucleic Acid Detection

CRISPR-Cas12a-based diagnostics are promising for field detection yet are often constrained by two step workflows or laborious optimization of one-pot reactions. Herein, we present a universal one-pot RPA/CRISPR-Cas12a strategy using base-mismatched crRNA in the seed region (positions 1-6). Introducing of single-nucleotide mismatches (complementary or error) into crRNA suppresses cis-cleavage activity, enabling amplification and detection in a single tube without PAM re-design or costly modified crRNA. Molecular dynamics (MD) simulations indicated that moderate potential energy (PE) variation correlates with improved screening performance, providing guidance for the selection of effective mismatches. This strategy successfully converted established two-step assays for Burkholderia pseudomallei and Brucella into one-pot formats, achieving detection of targets at 10 copies/L within 30 min with good specificity. Lyophilized pellets supported field testing on lithium-ion battery-powered devices, and experiments with simulated soil samples confirm the robustness of the approach. Together, this cost-effective, adaptable strategy can streamline RPA-CRISPR diagnostics for infectious disease surveillance.

molecular biology↗

A telomere-to-telomere (T2T) pig genome assembly reveals Y chromosome diversity and structural variations of Wuzhishan pigs

BackgroudWuzhishan (WZS) pigs are native to Hainan Province of China, and serve as both important agricultural resources and biomedical models. Although the published WZS pig genome (T2T-pig1.0) even achieving telomere-to telomere (T2T) completeness, substantial genetic diversity still exists within the same pig breed, another WZS pig genome named WZS-T2T was assembled in this study. ResultsMultiple sequencing data were used to assemble genome, and finally yielded a [~]2.68 Gb telomere-to-telomere genome, with N50 length [~]142.87 Mb, and annotated protein coding genes of 23,100. Compared to T2T-pig1.0, QV and BUSCO value was higher, and the Y chromosome (ChrY) length was longer in WZS-T2T than that of T2T-pig1.0. ChrY of two WZS pigs shared 11 genes, including sex differentiation-related genes of SHOX, PRKX, and DDX3X, and SRY; however, energy metabolism gene SLC25A4 and the macrophage-related receptor gene CSF2RA of ChrY were specific to WZS-T2T. An inversion SV on chromosome 10 with length [~]33.86 Mb was identified between two WZS pigs, and three proofs were proposed for proving the accuracy sequence orientation of WZS-T2T.The genetic diversity was consistent with LD decay speed in population different analysis. WZS pigs exhibited higher genetic diversity than other four pig populations (Tunchang pigs, Yuxi black pigs, Large White pig, and Duroc pigs) examined in this study, and presented slower LD decay compared to other four breeds. ConclusionsTherefore, WZS-T2T provided a higher-quality assembly, and potential advantages of both agricultural production and biomedical targets for WZS pigs.

genomics↗

Molecular Mechanisms Underlying Human Vγ9Vδ2 T Cell Activation by Butyrophilin-3 (BTN3) Targeted Antibodies

{gamma}{delta} T cells express T cell receptors (TCRs) composed of paired {gamma} and {delta} chains. The V{gamma}9V{delta}2 T cells are the main subpopulation of {gamma}{delta} T cells in human peripheral blood, which responds to phosphoantigens (pAgs) through butyrophilins (BTN) molecules, such as BTN3A1/2/3 and BTN2A1. Antibodies targeting BTN3As, such as ICT01, can activate V{gamma}9V{delta}2 T cells independently of pAgs, although the underlying mechanism remains poorly characterized. In this study, we reveal the molecular basis of ICT01-mediated V{gamma}9V{delta}2 T cell activation using structural, biochemical, and cellular analyses. ICT01 binds to a unique region in the extracellular domain of BTN3As, destabilizing the BTN2A1-BTN3As interface and facilitating V{gamma}9V{delta}2 TCR engagement, ultimately resulting in activation of V{gamma}9V{delta}2 T cells. Our findings provide insights into the mechanism by which agonist antibodies induce {gamma}{delta} T cell activation and provide guide strategies for developing BTN-targeted immunotherapies.

immunology↗

Targeting Endothelial PERK Accelerates Lymphoid Regeneration by Enhancing DLL4-NOTCH3 Signaling at the Pre-B Niche

Delayed immune recovery after hematopoietic stem cell (HSC) transplantation is associated with a poor clinical outcome, yet strategies to enhance lymphocyte regeneration are limited. We studied the role of unfolded protein response (ER stress) in hematopoietic regeneration within the bone marrow (BM) microenvironment. We revealed that PERK activation is a prominent feature of BM endothelium in leukemia patients and is a hallmark response in mouse BM following ionizing irradiation. Ablating endothelial Perk boosted Notch ligand DLL4 expression and promoted DLL4-dependent early HSC and B progenitor regeneration. Single-cell analysis shows that endothelial DLL4 activates NOTCH3 expressed by mesenchymal stroma cells, and that the PERK-DLL4 axis coordinates the regulation of lymphoid commitment and niche cytokine production. NOTCH3 is critical for the upregulation of IL7 following irradiation and for supporting the expansion of lymphoid progenitors in mesenchymal sphere cultures. These findings not only unveil a previously unrecognized ER stress-controlled vascular-stroma signaling mechanism in regenerative hematopoiesis but also highlight PERK blockade as a promising therapeutic strategy to improve immune recovery after myeloablative transplantation. SummaryZou et al unravel that the adaptive ER stress response in bone marrow blood vessels restricts the post-transplant regeneration of immune progenitor cells by attenuating the expression of Notch ligand DLL4. Targeting ER stress sensor PERK can accelerate immune recovery after transplantation by enhancing DLL4-NOTCH3 signaling and IL7 cytokine production.

cell biology↗

Phosphoantigen-Driven Dissociation of Butyrophilin Oligomers Activates γδ T Cells

{gamma}{delta} T cells represent a promising avenue for cancer immunotherapy. The V{gamma}9V{delta}2 T cell receptor (TCR), expressed by the predominant subset of {gamma}{delta} T cells, responds to phosphoantigen (pAg)-engaged butyrophilins (BTNs) on various cancer cells. However, the molecular mechanism underlying pAg-mediated activation of V{gamma}9V{delta}2 TCRs remains a subject of debate. Here, we employed an integrative approach to elucidate the mechanism of pAg reactivity in V{gamma}9V{delta}2 T cells. Our results demonstrate that BTNs form higher-order oligomers in the absence of pAg. Upon pAg binding, these oligomers dissociate into tetramers, enabling V{gamma}9V{delta}2 TCR engagement. This pAg-induced dissociation of higher-order BTN complexes is critical for pAg-mediated activation of {gamma}{delta} T cells. Our findings reveal a mechanism of BTN dissociation-driven pAg sensing, providing valuable insight for future immunotherapeutic strategies.

immunology↗

SntB triggers the antioxidant pathways to regulate development and aflatoxin biosynthesis in Aspergillus flavus

The epigenetic reader SntB was identified as an important transcriptional regulator of growth, development, and secondary metabolite synthesis in Aspergillus flavus. However, the underlying molecular mechanism is still unclear. In this study, sntB gene deletion ({Delta}sntB), complementary (Com-sntB), and HA tag fused to sntB (sntB-HA) strains were constructed by using the homologous recombination method, respectively. Our results revealed that deletion of sntB inhibited the processes of mycelia growth, conidial production, sclerotia formation, aflatoxin synthesis, and ability to colonize host, and the defective phenotype of knockout strain {Delta}sntB could be restored in its complementary strain Com-sntB. Chromatin immunoprecipitation sequencing (ChIP-seq) of sntB-HA and WT, and RNA sequencing (RNA-seq) of {Delta}sntB and WT strains revealed that SntB played key roles in oxidative stress response of A. flavus. The function of catC gene (encode a catalase) was further analyzed based on the integration results of ChIP-seq and RNA-seq. In {Delta}sntB strain, the relative expression level of catC was significantly higher than in WT strain, while a secretory lipase encoding gene (G4B84_008359) was down-regulated. Under the stress of oxidant menadione sodium bisulfite (MSB), the deletion of sntB obvious down-regulated the expression level of catC. After deletion of catC gene, the mycelia growth, conidial production, and sclerotia formation were inhibited, while ROS level and aflatoxin production were increased compared to the WT strain. Results also showed that the inhibition rate of MSB to {Delta}catC strain was significantly lower than that of WT group and AFB1 yield of the {Delta}catC strain was significantly decreased than that of WT strain under the stress of MSB. Our study revealed the potential machinery that SntB regulated fungal morphogenesis, mycotoxin anabolism, and fungal virulence through the axle of from SntB to fungal virulence and mycotoxin bio-synthesis, i.e. H3K36me3 modification-SntB-Peroxisomes-Lipid hydrolysis-fungal virulence and mycotoxin bio-synthesis. The results of this study shed light into the SntB mediated transcript regulation pathways of fungal mycotoxin anabolism and virulence, which provided potential strategy for control the contamination of A. flavus and its aflatoxins.

pharmacology and toxicology↗

Structure basis for recognition of 26RFa by the pyroglutamylated RFamide peptide receptor

The neuropeptide 26RFa, a member of the RF-amide peptide family, activates the pyroglutamylated RF-amide peptide receptor (QRFPR), a class A GPCR. The 26RFa/QRFPR system plays critical roles in energy homeostasis, making QRFPR an attractive drug target for treating obesity, diabetes, and eating disorders. However, the lack of structural information has hindered our understanding of the peptide recognition and regulatory mechanism of QRFPR, impeding drug design efforts. In this study, we determined the cryo-EM structure of the Gq-coupled QRFPR bound to 26RFa. The structure reveals a unique assembly mode of the receptor extracellular regions and the peptide N-terminus and elucidates the recognition mechanism of the C-terminal heptapeptide of 26RFa within the transmembrane binding pocket of QRFPR. The study also clarifies the similarities and distinctions in the binding pattern of the RF-amide moiety in five RF-amide peptides and the RY-amide segment in neuropeptide Y. These findings deepen our understanding of the RF-amide peptides recognition, aiding in the rational design of drugs targeting QRFPR and other RF-amide receptors.

biophysics↗

Adolescent oligodendrogenesis and myelination restrict experience-dependent neuronal plasticity in adult visual cortex

BACKGROUNDDevelopmental myelination is a protracted process in the mammalian brain. One theory for why oligodendrocytes mature so slowly posits that myelination may stabilize neuronal circuits and temper neuronal plasticity as animals age. We tested this hypothesis in the visual cortex, which has a well-defined critical period for experience-dependent neuronal plasticity. OBJECTIVES/METHODSTo prevent myelin progression, we conditionally deleted Myrf, a transcription factor necessary for oligodendrocyte maturation, from oligodendrocyte precursor cells (Myrf cKO) in adolescent mice. To induce experience-dependent plasticity, adult control and Myrf cKO mice were monocularly deprived by eyelid suture. Functional and structural neuronal plasticity in the visual cortex were assessed in vivo by intrinsic signal optical imaging and longitudinal two photon imaging of dendritic spines, respectively. RESULTSDuring adolescence, visual experience modulated the rate of oligodendrocyte maturation in visual cortex. Myrf deletion from oligodendrocyte precursors during adolescence led to inhibition of oligodendrocyte maturation and myelination that persisted into adulthood. Following monocular deprivation, visual cortex activity in response to visual stimulation of the deprived eye remained stable in adult control mice, as expected for post-critical period animals. By contrast, visual cortex responses to the deprived eye decreased significantly following monocular deprivation in adult Myrf cKO mice, reminiscent of the plasticity observed in adolescent mice. Furthermore, visual cortex neurons in adult Myrf cKO mice had fewer dendritic spines and a higher level of spine turnover. Finally, monocular deprivation induced spatially coordinated spine size decreases in adult Myrf cKO, but not control, mice. CONCLUSIONSThese results demonstrate a critical role for oligodendrocytes in shaping the maturation and stabilization of cortical circuits and support the concept of myelin acting as a brake on neuronal plasticity during development.

neuroscience↗

Inducing highly physiologically relevant phenotypes of human vascular smooth muscle cells via 3D printing

Vascular smooth muscle cells (vSMCs) are one of the essential cell types in blood vessel walls. A significant vSMC phenotype characteristic is that they collectively wrap around the outer layer of the healthy blood vessels with spindle-like morphology and help maintain the vascular tones and regulate the blood flow. Both physiological and biomedical research are impeded by the standard 2D cell culture approaches which do not create in vivo like microenvironment. Here, we systematically investigated the vSMCs culturing within 3D printed geometrical constraints and on printed microfilaments. Based on these models, we demonstrate a simple bioprinting approach for fast manufacturing vessel architectures with micro-grooved surfaces for vSMCs alignment. We validated that the vSMCs cultured on the printed vessel with microfilaments (VWMF) present a more physiologically relevant morphological phenotype and gene expression profile, and they are considerably more active in wound healing and ischemia than conventional planarly cultured vSMCs.

bioengineering↗

Astrocyte redox dysregulation causes prefrontal hypoactivity: sulforaphane treats non-ictal pathophysiology in ALDH7A1-mediated epilepsy

A fundamental but unanswered question in neuropsychiatry is whether the psychiatric symptoms of epilepsy are caused by the same or a separate pathophysiology as seizures. To address this question, we investigated a monogenic form of epilepsy (pyridoxine-dependent epilepsy) caused by aldehyde dehydrogenase 7a1 (ALDH7A1) mutations. ALDH7A1 global knockout mice exhibited both seizure-associated and affective behavioral phenotypes. However, seizure phenotypes were caused by ALDH7A1 deletion in hepatocytes whereas affective behaviors were caused by ALDH7A1 deletion in astrocytes. Deletion in astrocytes disrupted astrocyte redox homeostasis, impairing regulation of extracellular ion concentrations and reducing neuronal activity in the prelimbic cortex. Sulforaphane, which activates the NRF2 antioxidant pathway, restored prelimbic neuronal activity and rescued affective behaviors in ALDH7A1 knockout mice, but did not prevent seizures. These studies implicate astrocyte redox homeostasis and prelimbic hypoactivity in the psychiatric manifestations of a congenital form of epilepsy, which are mechanistically and therapeutically separate from the seizure pathophysiology. TeaserAntioxidant imbalance in astrocytes reduces neuronal activity, causing psychiatric symptoms in epilepsy distinct from seizures.

neuroscience↗

Deleting a UBE3A substrate rescues impaired hippocampal physiology and learning in Angelman syndrome mice

In humans, loss-of-function mutations in the UBE3A gene lead to the neurodevelopmental disorder Angelman syndrome (AS). AS patients have severe impairments in speech, learning and memory, and motor coordination, for which there is currently no treatment. In addition, UBE3A is duplicated in >1-2% of patients with autism spectrum disorders - a further indication of the significant role it plays in brain development. Altered expression of UBE3A, an E3 ubiquitin ligase, is hypothesized to lead to impaired levels of its target proteins, but identifying the contribution of individual UBE3A targets to UBE3A-dependent deficits remains of critical importance. Ephexin5 is a putative UBE3A substrate that has restricted expression early in development, regulates synapse formation during hippocampal development, and is abnormally elevated in AS mice, modeled by maternally-derived Ube3a gene deletion. Here, we report that Ephexin5 is a direct substrate of UBE3A ubiquitin ligase activity. Furthermore, removing Ephexin5 from AS mice specifically rescued hippocampus-dependent behaviors, CA1 physiology, and deficits in dendritic spine number. Our findings identify Ephexin5 as a key driver of hippocampal dysfunction and related behavioral deficits in AS mouse models. These results demonstrate the exciting potential of targeting Ephexin5, and possibly other UBE3A substrates, to improve symptoms of AS and other UBE3A-related developmental disorders.

neuroscience↗

Estrogen accelerates heart regeneration by promoting inflammatory responses in zebrafish

Sexual differences are observed in the onset and prognosis of human cardiovascular diseases, but the underlying mechanisms are not clear. Here, we report that zebrafish heart regeneration is faster in females, can be accelerated by estrogen and suppressed by estrogen-antagonist tamoxifen. Injuries to the heart, but not other tissues, increased plasma estrogen level and expression of estrogen receptors, especially esr2a, in zebrafish hearts. The resulting endocrine disruption induces the expression of female-specific protein vitellogenin in male zebrafish. Transcriptomic analyses suggested heart injuries triggered more pronounced immune and inflammatory responses in females. These responses, previously shown to enhance heart regeneration, could be enhanced by estrogen treatment in males and reduced by tamoxifen in female. Furthermore, a brief exposure to estrogen could precondition zebrafish for an accelerated heart regeneration. Altogether, this study reveals that heart regeneration is modulated by an estrogen-inducible inflammatory response to heart injury. These findings elucidate a previously unknown layer of control in zebrafish heart regeneration and provides a new model system for the study of sexual differences in human cardiac repair.

developmental biology↗