Biology subjects

Yang, D.

Publications and source records attributed to Yang, D..

At least 127 records · Page 7Linked to original sources

bioRxiv2024

Human birth tissue products as a regenerative medicine to inhibit post-surgical pain through multi-modal action

Pain after surgery causes significant suffering. Opioid analgesics cause severe side effects and accidental death. Therefore, there is an urgent need to develop non-opioid therapies for managing post-surgical pain. Local application of Clarix Flo (FLO), a human amniotic membrane (AM) product, attenuated established post-surgical pain hypersensitivity without exhibiting known side effects of opioid use in mice. This effect was achieved through direct inhibition of nociceptive dorsal root ganglion (DRG) neurons via CD44-dependent pathways. We further purified the major matrix component, the heavy chain-hyaluronic acid/pentraxin 3 (HC-HA/PTX3) from human AM that has greater purity and water solubility than FLO. HC-HA/PTX3 replicated FLO-induced neuronal and pain inhibition. Mechanistically, HC-HA/PTX3 induced cytoskeleton rearrangements to inhibit sodium current and high-voltage activated calcium current on nociceptive neurons, suggesting it is a key bioactive component mediating pain relief. Collectively, our findings highlight the potential of naturally derived biologics from human birth tissues as an effective non-opioid treatment for post-surgical pain. Moreover, we unravel the underlying mechanisms of pain inhibition induced by FLO and HC-HA/PTX3.

neuroscience↗

bioRxiv2024

Linking Altered Neuronal and Synaptic Properties to Nicotinic Receptor Alpha5 Subunit Gene Dysfunction: A Translational Investigation in Rat mPFC and Human Cortical Layer 6

BackgroundGenetic variation in the 5 nicotinic acetylcholine receptor (nAChR) subunit of mice results in behavioral deficits linked to the prefrontal cortex (PFC). A Single Nucleotide Polymorphisms (SNP) in CHRNA5 imparts a partial loss of function to the 5 subunit-containing (5*) nAChRs and have been demonstrated to be associated with psychiatric disorders in humans, including schizophrenia, nicotine dependence, cocaine and alcohol addiction. MethodsWe performed single cell-electrophysiology combined with morphological reconstructions on layer 6 (L6) excitatory neurons in the medial PFC (mPFC) of wild type (WT) rats (n = 25), rats carrying the human coding polymorphism rs16969968 in Chrna5 (n = 11) and 5 knockout (KO) rats (n = 28). Neuronal and synaptic properties were compared among three rat genotypes. Galantamine was applied to identified L6 neuron populations to specifically boost the nicotinic responses mediated by 5*nAChRs in the rat mPFC and human neocortex (n = 6 patients). ResultsCompared with neurons in WT rats, L6 regular spiking (RS) neurons in the 5KO group exhibited altered electrophysiological properties, while those in 5SNP rats remained unchanged. L6 RS neurons in mPFC of 5SNP and 5KO rats differed from WT rats in dendritic morphology, spine density and spontaneous synaptic activity. Galantamine acted as a positive allosteric modulator of 5*nAChRs in RS but not burst spiking (BS) neurons in both rat and human cortical L6. ConclusionOur findings suggest that dysfunction in the 5 subunit gene leads to aberrant neuronal and synaptic properties, shedding light on the underlying mechanisms of cognitive deficits observed in human populations carrying 5SNPs. They highlight a potential pharmacological target for restoring the relevant behavioral output.

neuroscience↗

bioRxiv2024

Efficient Gene Editing and Overexpression of Gametophyte Transformation in a Model Fern

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-related nuclease (Cas) system allows precise and easy editing of genes in many plant species. However, this system has not yet been applied to any fern species due to the complex characteristics of fern genomes, genetics and physiology. Here, we established, for the first time, a protocol for gametophyte-based screening single-guide RNAs (sgRNAs) with high efficiency for CRISPR/Cas-mediated gene editing in a model fern species, Ceratopteris richardii. We utilized the C. richardii Actin promoter to drive sgRNA expression and enhanced CaMV 35S promoter to drive the expression of Streptococcus pyogenes Cas9 in this CRISPR-mediated editing system, which was employed to successfully edit a few genes (e.g., nucleotidase/phosphatase 1, CrSAL1; Cryptochrome 4, CRY4) and CrPDS, encoding a phytoene desaturase protein that resulted in an albino phenotype in C. richardii. Knockout of CrSAL1 resulted in significantly reduced stomatal conductance (gs), leaf transpiration rate (E), stomatal/pore length, and abscisic acid (ABA)-induced reactive oxygen species (ROS) accumulation in guard cells. Moreover, CrSAL1 overexpressing plants showed significantly increased net photosynthetic rate (A), gs, E and intrinsic water use efficiency (iWUE) as well as most of the stomatal traits and ROS production in guard cells compared to those in the wild-type (WT) plants. Taken together, the optimized CRISPR/Cas9 system provides a useful tool for functional genomics in a model fern species, allowing the exploration of fern gene functions for evolutionary biology, herbal medicine discovery and agricultural applications.

plant biology↗

bioRxiv2024

Mx1-labeled pulp progenitor cells are main contributors to postnatal odontoblasts and pulp cells in murine molars

Regeneration of dentin and odontoblasts from dental pulp stem cells (DPSCs) is essential for permanent tooth maintenance. However, the in vivo identity and role of endogenous DPSCs in reparative dentinogenesis are elusive. Here, using pulp single-cell analysis before and after molar eruption, we revealed that endogenous DPSCs are enriched in Cxcl12-GFP+ coronal papilla-like cells with Mx1-Cre labeling. These Mx1+Cxcl12-GFP+ cells are long-term repopulating cells that contribute to the majority of pulp cells and new odontoblasts after eruption. Upon molar injury, Mx1+ DPSCs localize into the injury site and differentiate into new odontoblasts, forming scleraxis-GFP+ and osteocalcin-GFP+ dentinal tubules and reparative dentin. Single-cell and FACS analysis showed that Mx1+Cxcl12-GFP+ DPSCs are the most primitive cells with stem cell marker expression and odontoblast differentiation. Taken together, our findings demonstrate that Mx1 labels postnatal DSPCs, which are the main source of pulp cells and new odontoblasts with reparative dentinogenesis in vivo.

cell biology↗

bioRxiv2024

Granzyme B-based CAR T cells block metastasis by eliminating circulating tumor cells

Chimeric antigen receptor (CAR) T cells have limited efficacy against solid tumors due to the hostile microenvironment. Circulating tumor cells (CTCs) are essential to metastasis, which is the cause of most of cancer-related death. Here, we generated GrB-CAR T cells targeting membrane-bound HSP70 (mHSP70), a highly tumor-specific antigen detected in numerous cancers. GrB-CAR T cells exhibited potent cytotoxicity against a broad spectrum of cancer cell lines and stem-like cancer cells in vitro and effectively inhibited xenograft tumor growth in vivo. Importantly, GrB-CAR T cells markedly decreased the number of CTCs and, therefore, hindered cancer metastasis in spontaneous metastasis models with uncontrollable primary tumor growth, a scenario commonly encountered in clinical trials of CAR T therapies for solid tumors. Furthermore, despite the 100% homology between human and macaque HSP70 protein, the autotransplantation of macaque T cells expressing human GrB-CAR did not cause any obvious toxic effects. These results not only demonstrate GrB-CAR T cells as a safe and effective tactic with broad-spectrum anticancer activity, but also offer strong experimental evidence and proof-of-concept validation for CAR T cell-mediated metastasis inhibition by targeting CTCs.

immunology↗

bioRxiv2024

Synfire Chain Dynamics Unravelling Theta-nested Gamma Oscillations for Balancing Prediction and Dodge in Navigation

Theta-nested gamma oscillations, widely observed in experiments, play a crucial role in navigation, yet their functional roles and the origin of the positive correlation between theta frequency and motion velocity remain unclear. We propose that the objects survival relies on both prediction and dodge - predicting future events and staying alert to unpredictable ones, the latter of which has seldom been considered in goal-navigation tasks. By building a biologically plausible spiking neuronal network model and reproducing experimental results, we leverage synfire chain properties - length and separation - to elucidate the functional roles of theta-nested gamma oscillations: theta oscillations for self-location awareness, gamma oscillations for predictive capabilities and their coupling for enhancing functionality. The positive correlation between theta frequency and motion velocity is demonstrated to optimally balance representing predictable events for planning and staying alert to unexpected events. Our study offers a new avenue for unravelling the neural mechanisms of navigation.

neuroscience↗

bioRxiv2024

The catabolism of alanine and glutamate ensure proper sporulation by respectively preventing premature germination and providing energy sources

Sporulation as a typical bacterial differentiation process has been studied for decades. However, two crucial aspects of sporulation, (i) the energy sources supporting the process, and (ii) the maintenance of spore dormancy throughout sporulation, are scarcely explored. Here, we reported the crucial role of RocG-mediated glutamate catabolism in regulating mother cell lysis, a critical step for successful sporulation, likely by providing energy metabolite ATP. Notably, rocG overexpression resulted in an excessive ATP accumulation in sporulating cells, leading to adverse effects on future spore properties, e.g. increased germination efficiency, reduced DPA content, and lowered heat resistance. Additionally, we revealed that Ald-mediated alanine metabolism decreased the typical germinant L-alanine concentration in sporulating environment, thereby preventing premature germination and maintaining spore dormancy. Our data inferred that sporulation was a highly orchestrated biological process requiring a delicate balance in diverse metabolic pathways, hence ensuring both the completion of sporulation and production of high-quality spores.

microbiology↗

bioRxiv2024

Mathematical Modelling Indicates Th-cell Targeted Antibody-Dependent Cellular Cytotoxic Is a Crucial Obstacle Hurdling HIV Vaccine Development

HIV poses a significant threat to human health. Although some progress has been made in the development of an HIV vaccine, there is currently no reported success in achieving an effective and fully functional vaccine for HIV. This highlights the challenges involved in HIV vaccine development. Through mathematical modeling, we have conducted a systematic study on the impact of antibody-dependent cellular cytotoxicity (ADCC) on HIV-specific immune responses. Unlike other viral infections, the ADCC effect following HIV infection may cause significant damage to the follicular center Th cells, leading to apoptosis of follicular center cells and rapid death of effector Th cells. This impedes the generation of neutralizing antibodies and creates barriers to viral clearance, thereby contributing to long-term infection. Another challenge posed by this effect is the substantial reduction in vaccine effectiveness, as effective antigenic substances such as gp120 bind to Th cell surfaces, resulting in the apoptosis of follicular center Th cells due to ADCC, hindering antibody regeneration. To address this issue, we propose the concept of using bispecific antibodies. By genetically editing B cells to insert the bispecific antibody gene, which consists of two parts-one targeting the CD4 binding site of HIV, such as the broadly neutralizing antibody 3BNC117, and the other targeting antibodies against other viruses, such as the spike protein of SARS-CoV-2-we can simultaneously enhance the levels of two pathogen-specific antibodies through stimulation with non-HIV-antigens corresponding to the other part of the chimeric antibody, such as the spike protein. This study contributes to the elucidation of the pathophysiology of HIV, while also providing a theoretical framework for the successful development of an HIV vaccine.

immunology↗

bioRxiv2024

A self-adaptive and versatile tool for eliminating multiple undesirable variations from transcriptome

Accurate identification of true biological signals from diverse undesirable variations in large-scale transcriptomes is essential for downstream discoveries. Herein, we develop a universal deep neural network, called DeepAdapter, to eliminate various undesirable variations from transcriptomic data. The innovation of our approach lies in automatic learning of the corresponding denoising strategies to adapt to different situations. The data-driven strategies are flexible and highly attuned to the transcriptomic data that requires denoising, yielding significant improvement in reducing undesirable variation originating from batches, sequencing platforms, and bio-samples with varied purity beyond manually designed schemes. Comprehensive evaluations across multiple batches, different RNA measurement technologies and heterogeneous bio-samples demonstrate that DeepAdapter can robustly correct diverse undesirable variations and accurately preserve biological signals. Our findings indicate that DeepAdapter can act as a versatile tool for the comprehensive denoising of the large and heterogeneous transcriptome across a wide variety of application scenarios.

bioinformatics↗

bioRxiv2024

Comparative Metagenomics Provide Mechanistic Insights into the Biodegradation of the Non-hydrolysable Plastic Polyvinyl Chloride in Gut Microbiota of Insect Larvae

Using microbiomes to mitigate global plastic pollution is of paramount importance. Insect microbiomes have garnered emerging interest for their ability to biodegrade non-hydrolysable plastic polymers. The larvae of Spodoptera frugiperda, a globally prevalent migratory crop pest, are accidentally discovered to consume polyvinyl chloride (PVC) plastic films, highlighting the role of their gut microbiome. Following the migration of S. frugiperd in China, this study displays a comprehensive geographical profile of its larval gut microbiota and a significant shift after PVC feeding. Using comparative metagenomics we revealed the functional redundancy within the larval gut microbiomes of two distinct insects after PVC ingestion, we discovered a surprisingly potent PVC-dechlorinating activity of an NADH peroxidase (6.48 mg/L chlorine produced in 96 hours with NADH as a cofactor) encoded by Enterococcus casseliflavus EMBL-3. These findings open a new avenue for understanding plastic biodegradation mechanism and enable the development of biotechnologies to mitigate global plastic pollution.

microbiology↗

bioRxiv2024

CLSTN3B enhances adipocyte lipid droplet structure and function via endoplasmic reticulum contact

Interorganelle contacts facilitate material exchanges and sustain the structural and functional integrity of organelles. Lipid droplets (LDs) of adipocytes are responsible for energy storage and mobilization responding to body needs. LD biogenesis defects compromise the lipid-storing capacity of adipocytes, resulting in ectopic lipid deposition and metabolic disorders, yet how the uniquely large LDs in adipocytes attain structural and functional maturation is incompletely understood. Here we show that the mammalian adipocyte-specific protein CLSTN3B is crucial for adipocyte LD maturation. CLSTN3B employs an arginine-rich segment to promote extensive contact and hemifusion-like structure formation between the endoplasmic reticulum (ER) and LD, allowing ER-to-LD phospholipid diffusion during LD expansion. CLSTN3B ablation results in reduced LD surface phospholipid density, increased turnover of LD-surface proteins, and impaired LD functions. Our results establish the central role of CLSTN3B in the adipocyte-specific LD maturation pathway that enhances lipid storage and maintenance of metabolic health under caloric overload.

cell biology↗

bioRxiv2024

Nonnative Fish in the Pearl River Delta: A Comprehensive Study on Their Salinity Adaptability and Potential Distribution Area in Brackish Water

After extensive aquaculture, urbanization, and industrial development, the Pearl River Delta (PRD) has undergone profound environmental changes, with biological invasion emerging as a consequential anthropogenic byproduct, carrying significant implications for natural ecosystems, human health, and the economy. Despite these transformations, our understanding of nonnative fish species and their adaptability to the dynamic environmental conditions within the intricate river network of the PRD remains incomplete. To address this, we conducted a systematic survey of nonnative fish species in PRD waters through literature reviews. Then we analyzed the salinity adaptation of these fish, coupled with a spatial examination of salinity distribution, to comprehensively understand the potential invasion mechanisms of exotic fish in the region. Our findings identified 25 nonnative fish species in PRD waters, with three being translocated species within China and the remaining 22 being exotic introductions. Phylogenetically, these fish are broadly distributed among several orders, with Cichliformes, Perciformes, Cypriniformes, and Siluriformes emerging as the predominant orders. Despite most of the nonnative fish being freshwater species and exhibiting species-specific differences in salinity adaptability, they generally demonstrated an average salinity tolerance of 23.74 ppt, allowing them to adjust to brackish water. The diversity of species declined as the relative distance decreased from the upstream of the Pearl River Estuary (PRE) to its mouth in the sea (p < 0.01). Spatial analysis unveiled pronounced heterogeneity in salinity distribution, particularly in the east PRE of the LingDing Bay, featuring a sizable area with brackish water. Notably, under salinity intrusion circumstances, a gap region between salinity levels of 5.0 ppt and 15.0 ppt, spanning 3111.2 km2, emerged as a potential adaptation zone for nonnative fish. By emphasizing salinity as a key factor, our study may contribute to elucidating invasion mechanisms and enhancing the assessment of invasion risks in estuarine environments.

ecology↗

bioRxiv2023

Pharmacokinetics, Tissue Distribution, and Formulation Study of a Small-molecule Inhibitor of MKLP2, LG157

LG157 is a recently identified small-molecule inhibitor of mitotic kinesin-like protein 2 (MKLP2), an overlooked oncology target. This study aims to explore the drug developability of LG157, by assessing its druglike properties, determining plasma drug exposure in various oral formulations, and exploring the self-emulsifying drug delivery system (SEDDS). Solubility of LG157 ranges from 175 to 228 M across pH 1.0 to 13.0, with a LogD of 2.41 at pH 7.4. It showed a high protein binding rate of 92.58% in mouse plasma and 90.30% in human serum. The bioavailability radar plot aligns with experimental data (69-85%), indicating good bioavailability. In line with the computation prediction, preclinical formulation studies in mice reveal that all five formulations tested offer decent plasma LG157 exposure, with the highest level of LG157 exposure in the PEG300-based formulation. Subsequent tissue distribution studies in rats indicated that the compound is widely distributed with the highest concentration of LG157 in the liver and the lowest level in the brain. The optimal SEDDS formulation, SEDDS-F14, consists of 65% Oleic acid, 26.25% Tween 20, and 8.75% PEG400 as oil, surfactant, and co-surfactant, respectively. SEDDS optimization, based on the central composite design, has achieved the maximum loading of 188.7 mg/mL for LG157. These findings support the developability of LG157 and encourage continued exploration and refinement of formulations for improved therapeutic efficacy. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=135 SRC="FIGDIR/small/573327v1_ufig1.gif" ALT="Figure 1"> View larger version (37K): org.highwire.dtl.DTLVardef@11b4bb7org.highwire.dtl.DTLVardef@107e320org.highwire.dtl.DTLVardef@d06f55org.highwire.dtl.DTLVardef@3d4854_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2023

Antibiotics at Clinical Concentrations Show Limited Effectivity Against Acute and Chronic Intracellular S. aureus Infections in Osteocytes

ObjectivesCase numbers of osteomyelitis are rising and chronic infections remain difficult to cure. While it is known that the major pathogen Staphylococcus aureus can persist intracellularly in osteocytes, the effectivity of antibiotics against this condition remains largely unknown. We sought to determine if current clinically utilised antibiotics were capable of clearing an intracellular osteocyte S. aureus infection. MethodsRifampicin, vancomycin, levofloxacin, ofloxacin, amoxicillin, oxacillin, doxycycline, linezolid, gentamicin and tigecycline were assessed for their MIC and minimum bactericidal concentrations (MBC) against 11 S. aureus clinical isolates and the reference strain ATCC 25923, at pH 5.0 and 7.2 to mimic lysosomal and cytoplasmic environments, respectively. Those antibiotics whose bone achievable concentration was commonly above their respective MICs for the strains tested were further assayed in a human osteocyte infection model under either acute or chronic conditions. Osteocyte-like cells were treated at 1, 4 and 10x the MIC for 1 and 7 days following infection (acute model), or after 14 days of infection (chronic model). The intracellular effectivity of each antibiotic was measured in terms of colony forming unit (CFU) reduction, small colony variant (SCV) formation and bacterial mRNA expression change. ResultsOnly rifampicin, levofloxacin and linezolid reduced intracellular CFU numbers significantly in the acute model. The effect was larger after 7 days compared to 1 day of treatment. However, no treatment reduced the quantity of bacterial mRNA, nor prevented non-culturable bacteria from returning to a culturable state. DiscussionThese findings indicate that S. aureus adapts phenotypically during intracellular infection of osteocytes, adopting a reversible quiescent state which is protected against antibiotics, even at 10x their MIC. Thus, new therapeutic approaches are necessary to cure S. aureus intracellular infections in osteocytes.

microbiology↗

bioRxiv2023

Hyperosmolality tolerance of freshwater largemouth bass (Micropterus salmoides) to brackish at early ontogenetic stages: Eggs, embryos and yolk-sac larvae

Salinity is recognized as a pivotal factor limiting the migration of freshwater fish to brackish environments. The largemouth bass (LMB, Micropterus salmoides), a globally translocated freshwater fish, exhibits estuarine distribution, yet its hyperosmoregulatory capacity during early ontogenetic stages remains inadequately understood. To investigate the impact of freshwater salinization, a series of experiments were conducted in the Pearl River Delta, China. The study aimed to elucidate the osmoregulatory abilities of LMB eggs and embryos, assess the salinity toxicity on hatching, and explore the acute effects of hyperosmolality on yolk-sac larvae. Our results revealed that freshwater-activated mature eggs and naturally fertilized oocytes maintained nearly identical osmotic homeostasis, with diameters of 1.38 {+/-} 0.068 mm and 1.37 {+/-} 0.054 mm, respectively. Furthermore, both exhibited peak water excretion at a salinity of 15.0 ppt. Remarkably, a reduction in water permeability was observed in hyperosmotic environments. Spontaneous hatching rates increased from 27.5 {+/-} 14.4% in the 1.0 ppt group to 75.1 {+/-} 12.0% in the 6.0 ppt group under fluctuating temperature conditions. Yolk-sac LMB larvae consistently reduced survival time from 12.5 d at 1.0 ppt to 50.7 {+/-} 2.1 min at 35.0 ppt. Similarly, more developed larvae also experienced a decrease in survival time. Logistic regression models fitting lethal time with salinity indicated a sharp decrease between 10.0 ppt and 20.0 ppt. These findings offer practical insights for predicting distribution patterns and enhancing aquaculture technology for LMB. Moreover, they may contribute theoretically to the broader understanding of the osmoregulatory mechanisms of freshwater fish.

physiology↗

bioRxiv2023

The Natural Products Discovery Center: Release of the First 8490 Sequenced Strains for Exploring Actinobacteria Biosynthetic Diversity

Actinobacteria, the bacterial phylum most renowned for natural product discovery, has been established as a valuable source for drug discovery and biotechnology but is underrepresented within accessible genome and strain collections. Herein, we introduce the Natural Products Discovery Center (NPDC), featuring 122,449 strains assembled over eight decades, the genomes of the first 8490 NPDC strains (7142 Actinobacteria), and the online NPDC Portal making both strains and genomes publicly available. A comparative survey of RefSeq and NPDC Actinobacteria highlights the taxonomic and biosynthetic diversity within the NPDC collection, including three new genera, hundreds of new species, and [~]7000 new gene cluster families. Selected examples demonstrate how the NPDC Portals strain metadata, genomes, and biosynthetic gene clusters can be leveraged using genome mining approaches. Our findings underscore the ongoing significance of Actinobacteria in natural product discovery, and the NPDC serves as an unparalleled resource for both Actinobacteria strains and genomes.

microbiology↗

bioRxiv2023

A Novel Role for CSA in the Regulation of Nuclear Envelope Integrity: Uncovering a Non-Canonical Function

Cockayne syndrome (CS) is an autosomal recessive premature ageing condition mainly characterized by microcephaly, growth failure, and neurodegeneration. It is caused by mutations in ERCC6 or ERCC8 genes which encode for Cockayne Syndrome B (CSB) and Cockayne Syndrome A (CSA) proteins, respectively. CSA and CSB have well-characterised roles in transcription-coupled nucleotide excision repair (TC-NER), responsible for the removal of bulky DNA lesions, including those caused by UV irradiation. Here, we report that CSA knockout cells and CSA patient cells (CS-A) carrying a loss-of-function mutation in the ERCC8 gene exhibit defects in nuclear envelope (NE) integrity. NE dysfunction is a characteristic phenotype of cells from progeroid disorders caused by mutation in NE proteins, such as Hutchinson-Gilford Progeria Syndrome (HGPS). However, it has never been reported in Cockayne Syndrome. We observed that CS-A cells displayed reduced levels of LAP2-emerin-MAN1 (LEM)-domain 2 (LEMD2) at the NE resulting in decreased formation of LEMD2-lamin A/C complexes. In addition, loss of CSA function caused increased actin stress fibers that contributed to enhanced mechanical stress to the NE. Altogether, these led to NE blebbing and ruptures in interphase, causing activation of the innate/immune cGAS/STING signaling pathway. Disrupting the linker of the nucleoskeleton and cytoskeleton (LINC) complex that is responsible for anchoring the cytoskeleton to the NE, rescued the NE phenotypes and reduced the activation of cGAS/STING pathway. This work has revealed a previously uncharacterized role for CSA in regulating NE integrity and shed light on mechanisms that may further explain some of the clinical phenotypes observed in CS patients such as neuroinflammation. This is to our knowledge, the first study showing NE dysfunction in a progeroid syndrome caused by mutations in a DNA damage repair protein, reinforcing the connection between NE deregulation and ageing.

cell biology↗

bioRxiv2023

E3 ligase ASB3 downregulates antiviral innate immunity by targeting MAVS for ubiquitin-proteasomal degradation

E3 ubiquitin ligases are very important to regulate antiviral immunity during viral infection. Here, we discovered that Ankyrin repeat and SOCS box-containing protein 3 (ASB3), an E3 ligase, are upregulated in the presence of RNA viruses, particularly Influenza A virus (IAV). Notably, overexpression of ASB3 inhibits type I IFN (IFN-I) responses induced by Sendai virus (SeV) and H9N2, and ablation of ASB3 restores SeV and H9N2 infection-mediated transcription of IFN-{beta} and its downstream interferon-stimulated genes (ISGs). Interestingly, animals lacking ASB3 showed a decreased susceptibility to H9N2 and PR8 infections. Mechanistically, ASB3 interacts with MAVS and directly mediates K48-linked polyubiquitination and degradation of MAVS at K297, thereby inhibiting the phosphorylation levels of TBK1 and IRF3, downregulating downstream antiviral signaling. These findings establish ASB3 as a critical negative regulator in controlling the activation of antiviral signaling and describe a novel function of ASB3 that has not been previously reported. IMPORTANCEIAV is a significant zoonotic pathogen that causes infections of the respiratory system. Hosts have evolved multiple strategies to defend against IAV infection. However, not all host proteins play an active defense role. In this study, we found that the E3 ligase ASB3 regulates antiviral immunity by manipulating MAVS stability. Briefly, overexpression of ASB3 degrades MAVS, thereby promoting viral replication. In contrast, ASB3 deletion restores MAVS expression, upregulating IFN-I responses. Additional research revealed that ASB3 mediates the K48-linked polyubiquitination of MAVS at K297, resulting in ASB3 being degraded via the ubiquitin-proteasome pathway. These findings reveal, for the first time, a novel mechanism by which ASB3 negatively regulates antiviral immunity and provides a potential target for anti-IAV drug development.

immunology↗