Biology subjects

Wang, C.

Publications and source records attributed to Wang, C..

At least 829 records · Page 46Linked to original sources

bioRxiv2021

Intrinsically disordered N-terminal domain (NTD) of p53 interacts with mitochondrial PTP regulator Cyclophilin D

Mitochondrial permeability transition pore (mPTP) plays crucial roles in cell death in a variety of diseases, including ischemia/reperfusion injury in heart attack and stroke, neurodegenerative conditions, and cancer. To date, cyclophilin D is the only confirmed component of mPTP. Under stress, p53 can translocate into mitochondria and interact with CypD, triggering necrosis and cell growth arrest. However, the molecular details of p53/CypD interaction are still poorly understood. Previously, several studies reported that p53 interacts with CypD through its DNA-binding domain (DBD). However, using surface plasmon resonance (SPR), we found that full-length p53 (FLp53) binds to CypD with KD of ~1 M, while both NTD-DBD and NTD bind to CypD at ~10 M KD (Fig. 1C and 1D). Thus, instead of DBD, NTD is the major CypD binding site on p53. NMR titration and MD simulation revealed that NTD binds CypD with broad and dynamic interfaces dominated by electrostatic interactions. NTD 20-70 was further identified as the minimal binding region for CypD interaction, and two NTD fragments, D1 (residues 22-44) and D2 (58-70), can each bind CypD with mM affinity. Our detailed biophysical characterization of the dynamic interface between NTD and CypD provides novel insights on the p53-dependent mPTP opening and drug discovery targeting NTD/CypD interface in diseases. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=123 SRC="FIGDIR/small/453429v2_fig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@12a85b4org.highwire.dtl.DTLVardef@aff747org.highwire.dtl.DTLVardef@936401org.highwire.dtl.DTLVardef@8a893b_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFig. 1.C_FLOATNO p53 binds to CypD at M affinity determined by surface plasmon resonance (SPR). (A) SPR scheme (top) and p53 construct (bottom). (B) SPR sensorgrams of the full length p53 (FLp53)-CypD interaction. The concentrations of FLp53 (from top to bottom) were 2.0, 1.0, 0.5, 0.25, and 0.13 M, respectively. (C) SPR sensorgrams of the NTD-DBD-CypD interaction. The concentrations of NTD-DBD (from top to bottom) were 50, 25, 12.5, 6.25, and 3.13 M, respectively. (D) SPR sensorgrams of the NTD-CypD interaction. The concentrations of NTD (from top to bottom) were 40, 25, 12.5, 6.25, and 3.13 M, respectively. (E) SPR sensorgrams of the interaction between CypD and NTD1-70. The concentrations of NTD1-70 (from top to bottom) were 10, 5, 2.5, 1.25, and 0.63 M, respectively. All SPR sensorgrams are fitted using 1:1 Langmuir binding model (Black curves) in BIAevaluation software 4.0.1. C_FIG

biochemistry↗

bioRxiv2021

Defining the Sensitivity Landscape of 74,389 EGFR Variants to Tyrosine Kinase Inhibitors

BackgroundTyrosine kinase inhibitors (TKIs) therapy is a standard treatment for patients with advanced non-small-cell lung carcinoma (NSCLC) when activating epidermal growth factor receptor (EGFR) mutations are detected. However, except for the well-studied EGFR mutations, most EGFR mutations lack treatment regimens. MethodsWe constructed two EGFR variant libraries containing substitutions, deletions, or insertions using the saturation mutagenesis method. All the variants were located in the EGFR mutation hotspot (exons 18-21). The sensitivity of these variants to afatinib, erlotinib, gefitinib, icotinib, and osimertinib was systematically studied by determining their enrichment in massively parallel cytotoxicity assays using an endogenous EGFR-depleted cell line, PC9. ResultsA total of 3,914 and 70,475 variants were detected in the constructed EGFR Substitution-Deletion (Sub-Del) and exon 20 Insertion (Ins) libraries, accounting for 99.3% and 55.8% of the designed variants, respectively. Of the 3,914 Sub-Del variants, 813 were highly enriched in the reversible TKI (erlotinib, gefitinib, icotinib) cytotoxicity assays and 51 were enriched in the irreversible TKI (afatinib, osimertinib) cytotoxicity assays. For the 70,475 Ins variants, insertions at amino acid positions 770-774 were highly enriched in all the five TKI cytotoxicity assays. Moreover, the top 5% of the enriched insertion variants included a glycine or serine insertion at high frequency. ConclusionsWe present a comprehensive reference for the sensitivity of EGFR variants to five commonly used TKIs. The approach used here should be applicable to other genes and targeted drugs.

genetics↗

bioRxiv2021

Structure of the Infective Getah Virus at 2.8 A-resolution Determined by Cryo-electron Microscopy

Getah virus (GETV), a member of genus alphavirus, is a mosquito-borne pathogen that can cause pyrexia and reproductive losses in animals. Although antibodies to GETV have been found in over 10% of healthy people, there are no reports of clinical symptom associated with GETV. The biological and pathological properties of GETV are largely unknown. Here, we present the structure of infective GETV at a resolution of 2.8 [A] with the capsid protein and the envelope glycoproteins E1 and E2. We have identified numerous glycosylation and S-acylation sites in E1 and E2. The surface-exposed glycans revealed their impact on the viral immune evasion and host cell invasion. The S-acylation sites involve in stabilizing the transmembrane assembly. In addition, a cholesterol and a phospholipid molecule are observed in a transmembrane hydrophobic pocket, together with two more cholesterols surrounding the pocket. The structural information will assist structure-based antiviral and vaccine design.

biophysics↗

bioRxiv2021

Spinal ganglia control nociceptive input to the central nervous system

Accumulating observations suggest that peripheral somatosensory ganglia may regulate nociceptive transmission, yet direct evidence is sparse. Here we show that the peripheral afferent nociceptive information undergoes dynamic filtering within the dorsal root ganglion (DRG) and suggest that this filtering occurs at the axonal bifurcations (t-junctions). Using synchronous in vivo electrophysiological recordings from the peripheral and central processes of sensory neurons (in the spinal nerve and dorsal root), ganglionic transplantation of GABAergic progenitor cells, and optogenetics we demonstrate existence of tonic and dynamic filtering of action potentials traveling through the DRG. Filtering induced by focal application of GABA or optogenetic GABA release from the DRG-transplanted GABAergic progenitor cells was specific to nociceptive fibers. Light-sheet imaging and computer modeling demonstrated that, compared to other somatosensory fiber types, nociceptors have shorter stem axons, making somatic control over t-junctional filtering more efficient. Optogenetically-induced GABA release within DRG from the transplanted GABAergic cells enhanced filtering and alleviated hypersensitivity to noxious stimulation produced by chronic inflammation and neuropathic injury in vivo. These findings support gating of pain information by DRGs and suggest new therapeutic approaches for pain relief.

neuroscience↗

bioRxiv2021

Dynamics of glioma-associated microglia and macrophages reveals their divergent roles in the immune response of brain

Glioma microenvironment contains numerous myeloid cells, including brain-resident microglia and recruited monocytes and macrophages (Mo/M{varphi}). When studied collectively, these cells presented pro-tumor effects. Yet, little is known about the differences among these myeloid populations. Using single-cell sequencing analysis, we studied the phenotypic characteristics, spatial variances, and dynamic changes of these relatively heterogeneous cell populations. Microglia populations with distinct spatial distribution presented different functional states, including tumor-associated subsets with phagocytic and lipid metabolism signature. Notably, this subset of glioma-associated microglia shared similar trait in a diverse spectrum of neuropathogenesis. In contrast, Mo/M{varphi} highly expressed genes related to angiogenesis, tumor invasion, and immune evasion. Moreover, identifying the Mo/M{varphi} subsets had prognostic and classificatory value in clinical application. These results thus eliminate the long-existing ambiguity about the role of microglia and Mo/M{varphi} in glioma pathogenesis, and reveal their prognostic and therapeutic value for glioma patients.

immunology↗

bioRxiv2021

Wall-associated Receptor Kinase and The Expression Profiles in Wheat Responding to Fungal Stress

Cell wall-associated kinases (WAKs), which are encoded by conserved gene families in plants, are crucial for development and responses to diverse stresses. However, the wheat (Triticum aestivum L.) WAKs have not been systematically classified, especially those involved in protecting plants from disease. Here, we classified 129 WAK proteins (encoded by 232 genes) and 75 WAK-Like proteins (WAKLs; encoded by 109 genes) into four groups, via a phylogenetic analysis. An examination of protein sequence alignment revealed diversity in the GUB-domain of WAKs structural organization, but it was usually characterized by a PYPFG motif followed by CxGxGCC motifs, while the EGF-domain was usually initiated with a YAC motif, and eight cysteine residues were spliced by GNPY motif. The expression profiles of WAK-encoding homologous genes varied in response to Blumeria graminis f. sp. tritici (Bgt), Puccinia striiformis f. sp. tritici (Pst) and Puccinia triticina (Pt) stress. A quantitative real-time polymerase chain reaction (qRT-PCR) analysis proved that TaWAK75 and TaWAK76b were involved in wheat resistance to Bgt. This study revealed the structure of the WAK-encoding genes in wheat, which may be useful for future functional elucidation of wheat WAKs responses to fungal infections.

plant biology↗

bioRxiv2021

Spatially resolved transcriptomics reveals unique gene signatures associated with human temporal cortical architecture and Alzheimer's pathology

Alzheimers disease (AD) is pathologically characterized by amyloid beta (A{beta}) plaques, neurofibrillary tangles (tau aggregates), and alterations in microglia, astrocytes and oligodendrocytes. The mesial temporal lobe is a vulnerable brain region in early AD; however, little is known about the transcriptome-scale gene expression in this region and its relation to AD pathology. Here we use the 10x Genomics Visium platform in combination with co-immunofluorescence staining of AD-associated pathological markers to define the spatial topography of gene expression in the middle temporal gyrus (MTG) from both early AD and age- and gender-matched control cases. We identify unique marker genes for six cortical layers and the adjacent white matter as well as gene expression patterns and alterations that showcase unique gene signatures and pathways associated with a range of AD pathology. Also, gene co-expression analyses of differentially expressed genes (DEGs) between AD and controls reveal four unique gene modules, which significantly change their co-expression patterns in the presence of variations of AD pathology. Furthermore, we validate the changes of key representative DEGs that are associated with AD pathology in neurons, microglia, astrocytes and oligodendrocytes using single-molecule fluorescent in situ hybridization. In summary, we provide a rich resource for the spatial transcriptomic profile of the human MTG, which will contribute to our understanding of the complex architecture and AD pathology of this vulnerable brain region.

neuroscience↗

bioRxiv2021

Tumour Suppressor Parafibromin/Hyrax Governs Cell Polarity and Centrosome Assembly in Neural Stem Cells

Neural stem cells (NSCs) divide asymmetrically to balance their self-renewal and differentiation, an imbalance in which can lead to NSC overgrowth and tumour formation. The functions of Parafibromin, a conserved tumour suppressor, in the nervous system are not established. Here, we demonstrate that Drosophila Parafibromin/Hyrax (Hyx) inhibits NSC overgrowth by governing cell polarity. Hyx is essential for the apicobasal polarization of NSCs, through its role in the asymmetric distribution of polarity proteins. hyx depletion results in the symmetric division of NSCs, leading to the formation of supernumerary NSCs in the larval brain. Importantly, we show that human Parafibromin can fully rescue NSC overgrowth and cell polarity defects in Drosophila hyx mutant brains. We have also discovered a novel role for Hyx in regulating the formation of interphase microtubule-organizing center and mitotic spindles in NSCs. Moreover, Hyx is required for the proper localization of a key centrosomal protein, Polo, and the microtubule-binding proteins Msps and D-TACC in dividing NSCs. Furthermore, Hyx directly regulates the polo expression in vitro. Altogether, our study provides the first evidence that the brain tumour suppressor-like role and polarity establishing functions of Hyx are mediated by its role in regulating microtubule growth and centrosomal assembly. The new paradigm that Parafibromin orchestrates cell polarization by regulating centrosomal assembly may be relevant to future studies on Parafibromin/HRPT2-associated cancers.

developmental biology↗

bioRxiv2021

Reduction of Derlin activity suppresses Notch-dependent tumours in the C. elegans germ line

Regulating the balance between self-renewal (proliferation) and differentiation is key to the long-term functioning of all stem cell pools. In the Caenorhabditis elegans germline, the primary signal controlling this balance is the conserved Notch signaling pathway. Gain-of-function mutations in the GLP-1/Notch receptor cause increased stem cell self-renewal, resulting in a tumor of proliferating germline stem cells. Notch gain-of-function mutations activate the receptor, even in the presence of little or no ligand, and have been associated with many human diseases, including cancers. We demonstrate that reduction in CUP-2 and DER-2 function, which are Derlin family proteins that function in endoplasmic-reticulum-associated degradation (ERAD), suppresses the C. elegans germline over-proliferation phenotype associated with glp-1(gain-of-function) mutations. We further demonstrate that their reduction does not suppress other mutations that cause over-proliferation, suggesting that over-proliferation suppression due to loss of Derlin activity is specific to glp-1/Notch (gain-of-function) mutations. Reduction of CUP-2 Derlin activity reduces the expression of a read-out of GLP-1/Notch signaling, suggesting that the suppression of over-proliferation in Derlin loss-of-function mutants is due to a reduction in the activity of the mutated GLP-1/Notch(GF) receptor. Over-proliferation suppression in cup-2 mutants is only seen when the Unfolded Protein Response (UPR) is functioning properly, suggesting that the suppression, and reduction in GLP-1/Notch signaling levels, observed in Derlin mutants may be the result of activation of the UPR. Chemically inducing ER stress also suppress glp-1(gf) over-proliferation but not other mutations that cause over-proliferation. Therefore, ER stress and activation of the UPR may help correct for increased GLP-1/Notch signaling levels, and associated over-proliferation, in the C. elegans germline. AUTHOR SUMMARYNotch signaling is a highly conserved signaling pathway that is utilized in many cell fate decisions in many organisms. In the C. elegans germline, Notch signaling is the primary signal that regulates the balance between stem cell proliferation and differentiation. Notch gain-of-function mutations cause the receptor to be active, even when a signal that is normally needed to activate the receptor is absent. In the germline of C. elegans, gain-of-function mutations in GLP-1, a Notch receptor, results in over-proliferation of the stem cells and tumor formation. Here we demonstrate that a reduction or loss of Derlin activity, which is a conserved family of proteins involved in endoplasmic-reticulum-associated degradation (ERAD), suppresses over-proliferation due to GLP-1/Notch gain-of-function mutations. Furthermore, we demonstrate that a surveillance mechanism utilized in cells to monitor and react to proteins that are not folded properly (Unfolded Protein Response-UPR) must be functioning well in order for the loss of Derlin activity to supress over-proliferation caused by glp-1/Notch gain-of-function mutations. This suggests that activation of the UPR may be the mechanism at work for suppressing this type of over-proliferation, when Derlin activity is reduced. Therefore, decreasing Derlin activity may be a means of reducing the impact of phenotypes and diseases due to certain Notch gain-of-function mutations.

genetics↗

bioRxiv2021

CRISPRa screening with real world evidence identifies potassium channels as neuronal entry factors and druggable targets for SARS-CoV-2

Although vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been successful, there are no good treatments for those who are actively infected. While SARS-CoV-2 primarily infects the respiratory tract, clinical evidence indicates that cells from sensory organs and the brain are also susceptible to infection. While many patients suffer from diverse neurological symptoms, the viruss neuronal entry remains mysterious. To discover host factors involved in SARS-CoV-2 viral entry, we performed CRISPR activation (CRISPRa) screens targeting all 6000+ human membrane proteins in cells with and without overexpression of ACE2 using Spike-pseudotyped lentiviruses. This unbiased gain-of-function screening identified both novel and previously validated host factors. Notably, newly found host factors have high expression in neuronal and immune cells, including potassium channel KCNA6, protease LGMN, and MHC-II component HLA-DPB1. We validated these factors using replication-competent SARS-CoV-2 infection assays. Notably, the overexpression of KCNA6 led to a marked increase in infection even in cells with undetectable levels of ACE2 expression. Analysis of human olfactory epithelium scRNA-seq data revealed that OLIG2+/TUJ1+ cells--previously identified as sites of infection in COVID-19 autopsy studies-- have high KCNA6 expression and minimal levels of ACE2. The presence of KCNA6 may thus explain sensory/neuronal aspects of COVID-19 symptoms. Further, we demonstrate that FDA-approved compound dalfampridine, an inhibitor of KCNA-family potassium channels, suppresses viral entry in a dosage-dependent manner. Finally, we identified common prescription drugs likely to modulate the top identified host factors, and performed a retrospective analysis of insurance claims of ~8 million patients. This large cohort study revealed a statistically significant association between top drug classes, particularly those targeting potassium channels, and COVID-19 severity. Taken together, the potassium channel KCNA6 facilitates neuronal entry of SARS-CoV-2 and is a promising target for drug repurposing and development.

genomics↗

bioRxiv2021

Phenotypic and genetic associations of quantitative magnetic susceptibility in UK Biobank brain imaging

A key aim in epidemiological neuroscience is identification of markers to assess brain health and monitor therapeutic interventions. Quantitative susceptibility mapping (QSM) is an emerging MRI technique that measures tissue magnetic susceptibility and has been shown to detect pathological changes in tissue iron, myelin and calcification. We developed a QSM processing pipeline to estimate magnetic susceptibility of multiple brain structures in 35,885 subjects from the UK Biobank prospective epidemiological study. We identified phenotypic associations of magnetic susceptibility that include body iron, disease, diet, and alcohol consumption. Genome-wide associations related magnetic susceptibility to genetic variants with biological functions involving iron, calcium, myelin, and extracellular matrix. These patterns of associations include relationships that are unique to QSM, in particular being complementary to T2* measures. These new imaging phenotypes are being integrated into the core UK Biobank measures provided to researchers world-wide, creating potential to discover novel, non-invasive markers of brain health.

neuroscience↗

bioRxiv2021

A survey of optimal strategy for signature-based drug repositioning and an application to liver cancer

Pharmacologic perturbation projects, such as Connectivity Map (CMap) and Library of Integrated Network-based Cellular Signatures (LINCS), have produced many perturbed expression data, providing enormous opportunities for computational therapeutic discovery. However, currently there is no consensus on which methodologies and parameters are the most optimal to conduct such analysis. Aiming to fill this gap, we developed new benchmarking standards for quantitatively estimating drug retrieval performance. Investigations of potential factors influencing drug retrieval were conducted based on these standards. As a result, we determined an optimal strategy for LINCS data-based therapeutic discovery. With this approach, we further identified new therapeutics for liver cancer of which the current treatment modalities remain imperfect. Both computational and experimental results demonstrated homoharringtonine (HHT) could be a promising anti-liver cancer agent. In summary, our findings will not only impact the future applications of LINCS data but also offer new opportunities for therapeutic intervention for liver cancer.

bioinformatics↗

bioRxiv2021

Synthesis and characterization of 5-(2-fluoro-4-pyridine-7-carboxamide as a PET imaging ligand for metabotropic glutamate receptor 2

Metabotropic glutamate receptor 2 (mGluR2) is a therapeutic target for the treatment of several neuropsychiatric disorders and conditions. The role of mGluR2 function in etiology could be unveiled by in vivo imaging using positron emission tomography (PET). In this regard, 5-(2- fluoro-4-[11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro-2H-pyrano[2,3-b]pyridine-7- carboxamide ([11C]13), a potent negative allosteric modulator (NAM), was developed to support this endeavor. Radioligand [11C]13 was synthesized via the O-[11C]methylation of phenol 24 with a high molar activity of 212 {+/-} 76 GBq/{micro}mol (n = 5) and excellent radiochemical purity (> 99%). PET imaging of [11C]13 in rats demonstrated its superior brain heterogeneity, particularly in the regions of striatum, thalamus, hippocampus, and cortex. Accumulation of [11C]13 in these regions of interest (ROIs) was reduced with pretreatment of mGluR2 NAMs, VU6001966 (9) and MNI-137 (26), the extent of which revealed a time-dependent drug effect of the blocking agents. In a nonhuman primate, [11C]13 selectively accumulated in mGluR2-rich regions, especially in different cortical areas, putamen, thalamus, and hippocampus, and resulted in high-contrast brain images. The regional total volume of distribution (VT) estimates of [11C]13 decreased by 14% after the pretreatment with 9. Therefore, [11C]13 is a potential candidate for translational PET imaging studies of mGluR2 function.

neuroscience↗

bioRxiv2021

Isolation and characterizations of a novel H6N1 avian influenza virus from Von Schrenck's Bittern (Ixobrychus eurhythmus) in Jiangxi province, China

In June 2013, the first case of human infection with an avian H6N1 virus was reported in a Taiwanese woman. Although this was a single non-fatal case, the virus continues to circulate in Taiwanese poultry. As with any emerging avian virus that infects humans, there is concern that acquisition of human-type receptor specificity could enable transmission in the human population. Despite mutations in the receptor-binding pocket of the human H6N1 isolate, it has retained avian-type (NeuAca2-3Gal) receptor specificity. An H6N1 AIV was isolated from a Von Schrencks Bittern during national active surveillance project for avian influenza viruses (AIVs) in wild birds in Jiangxi province, China 2018. Phylogenetic analysis showed that this strain received its genes from H1, H2, H3, H4, H6 and H10 AIVs in different places. This strain was found to be minimally pathogenic in mice and was able to replicate in mice without prior adaptation. Considering that the reassorted H6N1 virus was isolated from Von Schrencks Bittern in this study, it is possible that this bird can play an important role in the generation of novel reassorted H6 AIVs. In this study, H6N1 virus is a wild virus migration brought from different regions of the AIV gene into the natural gene pool, resulting in the production of a recombinant new virus. The H6N1 virus can be seen as a link in the evolution of the virus and the evolution of other viruses.

molecular biology↗

bioRxiv2021

The Digital Brain Bank: an open access platform for post-mortem datasets

Post-mortem MRI provides the opportunity to acquire high-resolution datasets to investigate neuroanatomy, and validate the origins of image contrast through microscopy comparisons. We introduce the Digital Brain Bank (open.win.ox.ac.uk/DigitalBrainBank), a data release platform providing open access to curated, multimodal post-mortem neuroimaging datasets. Datasets span three themes - Digital Neuroanatomist: datasets for detailed neuroanatomical investigations; Digital Brain Zoo: datasets for comparative neuroanatomy; Digital Pathologist: datasets for neuropathology investigations. The first Digital Brain Bank release includes twenty one distinctive whole-brain diffusion MRI datasets for structural connectivity investigations, alongside microscopy and complementary MRI modalities. This includes one of the highest-resolution whole-brain human diffusion MRI datasets ever acquired, whole-brain diffusion MRI in fourteen non-human primate species, and one of the largest post-mortem whole-brain cohort imaging studies in neurodegeneration. The Digital Brain Bank is the culmination of our labs investment into post-mortem MRI methodology and MRI-microscopy analysis techniques. This manuscript provides a detailed overview of our work with post-mortem imaging to date, including the development of diffusion MRI methods to image large post-mortem samples, including whole, human brains. Taken together, the Digital Brain Bank provides crossscale, cross-species datasets facilitating the incorporation of post-mortem data into neuroimaging studies.

neuroscience↗

bioRxiv2021

Fast alignment and preprocessing of chromatin profiles with Chromap

We present Chromap, an ultrafast method for aligning and preprocessing high throughput chromatin profiles. Chromap is comparable to BWA-MEM and Bowtie2 in alignment accuracy and is over 10 times faster than traditional workflows on bulk ChIP-seq / Hi-C profiles and than 10x Genomics CellRanger v2.0.0 pipeline on single-cell ATAC-seq profiles.

bioinformatics↗

bioRxiv2021

Tau interactome mapping reveals dynamic processes in synapses and mitochondria associated with neurodegenerative disease

Tau (MAPT) drives neuronal dysfunction in Alzheimers disease (AD) and other tauopathies. To dissect the underlying mechanisms, we combined an engineered ascorbic acid peroxidase (APEX) approach with quantitative affinity purification mass spectrometry (AP-MS) followed by proximity ligation assay (PLA) to characterize Tau interactomes modified by neuronal activity and mutations that cause frontotemporal dementia (FTD) in human induced pluripotent stem cell (iPSC)-derived neurons. We established activity-dependent interactions of Tau with presynaptic vesicle proteins during Tau secretion and mapped the exact APEX-tau-induced biotinylated tyrosines to the cytosolic domains of the interacting vesicular proteins. We showed that FTD mutations impair bioenergetics and markedly diminished Taus interaction with mitochondria proteins, which were downregulated in AD brains of multiple cohorts and correlated with disease severity. These multi-modal and dynamic Tau interactomes with unprecedented spatiotemporal resolution shed novel insights into Taus role in neuronal function and disease-related processes with potential therapeutic targets to block Tau-mediated pathogenesis.

neuroscience↗

bioRxiv2021

Engineered small extracellular vesicles as a FGL1/PD-L1 dual-targeting delivery system for alleviating immune rejection

There is an urgent need for developing new immunosuppressive agents due to the toxicity of long-term use of broad immunosuppressive agents post organ transplantation. Comprehensive sample analysis revealed dysregulation of FGL1/LAG-3 and PD-L1/PD-1 immune checkpoints in allogeneic heart transplantation mice and clinical kidney transplant patients. In order to enhance these two immunosuppressive signal axes, we developed a bioengineering strategy to simultaneously display FGL1/PD-L1 (FP) on the surface of small extracellular vesicles (sEVs). Among various cell sources, FP sEVs derived from mesenchymal stem cells (MSCs) not only enriched FGL1/PD-L1 expression but also maintained the immunomodulatory properties of unmodified MSC sEVs. Next, we confirmed that FGL1 and PD-L1 on sEVs were specifically bound to their receptors LAG-3 and PD-1 on target cells. Importantly, FP sEVs significantly inhibited T cell activation and proliferation in vitro and a heart allograft model. Furthermore, FP sEVs encapsulated with low-dose FK506 (FP sEVs@FK506) exerted stronger effects on inhibiting T cell proliferation, reducing CD8+ T cell density and cytokine production in the spleens and heart grafts, inducing regulatory T cells in lymph nodes, and extending graft survival. Taken together, dual-targeting sEVs have the potential to boost the immune inhibitory signalings in synergy and slow down transplant rejection.

bioengineering↗