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Wang, C.

Publications and source records attributed to Wang, C..

At least 379 records · Page 21Linked to original sources

Branched chain fatty acid-rich diet promotes lipid droplet enlargement and impacts organismal health in Caenorhabditis elegans

Considerable amounts of branched chain fatty acids (BCFAs) are present in the human diet from beef and dairy products. BCFAs can also be produced by the human gut microbiota and synthesized from branched chain amino acids. However, the physiological impact of a BCFA-rich diet on lipid metabolism and organismal health is unclear. In this study, by screening a collection of dietary bacteria, we find that the BCFA-rich Microbacterium diet causes the formation of supersized LDs and delays development, reduces brood size, and shortens lifespan of C. elegans. The high-BCFA diet downregulates argk-1/creatine kinase to inhibit the AMPK pathway and {beta}-oxidation and upregulates fat-7/desaturase to promote the accumulation of PUFA, which enhances lipogenesis and LD expansion. We also isolate a gain-of-function mutation in scav-4/CD36, which enhances BCFA absorption and exacerbates BCFA-induced LD enlargement, demonstrating that host genetic variation in a fatty acid transporter could influence the susceptibility to a high-BCFA diet.

cell biology↗

A Novel Optimized Silver Nitrate Staining Method for Visualizing the Osteocyte Lacuno-Canalicular System

A 50% silver nitrate solution is commonly used to stain and characterize the osteocyte lacuno-canalicular system (LCS) in bone biology research. However, variability in reagent concentrations and types, along with inconsistent staining procedures, have limited the broader application of this method in osteocyte research. In this study, we present a novel optimized silver nitrate staining technique aimed at addressing these limitations. This new method utilizes a 1 mol/L silver nitrate solution in combination with a type-B gelatin-formic acid solution at various concentrations (0.05%-0.5% gelatin and 0.05%-5% formic acid, or 1%-2% gelatin and 0.1%-2% formic acid) in volume ratios of 4:1, 2:1, or 1:1, or a 0.5 mol/L silver nitrate solution at a 4:1 ratio. The staining process is carried out for 1 hour under ultraviolet light or 90 minutes under regular room light (or dark), followed by washing with Milli-Q water to terminate the reaction. We applied this new method to stain the osteocyte LCS in bone samples from different species and pathological bone models. The technique consistently produced clear, distinct staining patterns across all samples. Moreover, our novel method revealed a greater number of LCS compared to the traditional 50% silver nitrate solution. This suggests that the commonly used 50% silver nitrate method may disrupt or inadequately reveal the LCS in certain species, potentially leading to an underestimation of LCS density and number. In conclusion, our novel silver nitrate staining method provides a simpler and more cost-effective alternative to the traditional technique. By offering a more accurate and comprehensive analysis of the LCS across species, this approach has the potential to advance research on osteocyte morphogenesis, as well as the functional and evolutionary adaptations of the osteocyte LCS across different taxa.

pathology↗

PSI Atlas: a comprehensive knowledgebase of plant self-incompatibility

Self-incompatibility (SI) is an important genetic mechanism in angiosperms that prevents inbreeding and promotes outcrossing. Although significant progress has been made in understanding SI, its molecular underpinnings and evolutionary origins remain elusive in many plant families. In eudicots, SI is typically regulated by a single S-locus with diverse S-haplotypes, while in grasses, it is controlled by two separate S and Z loci. Genome assemblies of SI plants have greatly facilitated the identification and evolutionary analysis of S-loci. However, a comprehensive database that integrates information on the diverse S-loci has been lacking. To fill this gap, we create the Plant Self-Incompatibility Atlas (PSIA, http://www.plantsi.cn), a knowledgebase that offers an extensive compilation of plant SI, including genomic resources for assembled SI species, the origins and evolution of S genes, and the molecular mechanisms of the eight known SI types. In our most recent release, we have obtained more than 500 genome assemblies across 469 SI species. We have also collected 1275 nucleotide and 1130 protein sequence accessions of S genes from public databases, with a total of 3095 S genes manually identified and curated. PSIA not only thoroughly explores the S-locus information of the assembled SI species but also enables users to efficiently browse, perform BLAST searches, analyze, and download S genes. Additionally, PSIA acts as a comprehensive platform for comparative genomic studies of S-loci, aiding in the exploration of the dynamic processes involved in the origin, loss, and regain of SI. Consequently, PSIA is poised to significantly enhance our understanding of angiosperm SI and offer new perspectives on plant mating systems.

plant biology↗

Structure of an LGR dimer - an evolutionary predecessor of glycoprotein hormone receptors

The glycoprotein hormones of humans, produced in the pituitary and acting through receptors in the gonads to support reproduction and in the thyroid gland for metabolism, have co-evolved from invertebrate counterparts1,2. These hormones are heterodimeric cystine-knot proteins; and their receptors bind the cognate hormone at an extracellular domain and transmit the signal of this binding through a transmembrane domain that interacts with a heterotrimeric G protein. Structures determined for the human receptors as isolated for cryogenic electron microscopy (cryo-EM) are all monomeric3-6 despite compelling evidence for their functioning as dimers7-10. Here we describe the cryo-EM structure of the homologous receptor from a neuroendocrine pathway that promotes growth in a nematode11. This structure is an asymmetric dimer that can be activated by the hormone from that worm12, and it shares features especially like those of the thyroid stimulating hormone receptor (TSHR). When studied in the context of the human homologs, this dimer provides a structural explanation for the transactivation evident from functional complementation of binding-deficient and signaling-deficient receptors7, for the negative cooperativity in hormone action that is manifest in the 1:2 asymmetry of primary TSH:TSHR complexes8,9, and for switches in G-protein usage that occur as 2:2 complexes form9,10.

molecular biology↗

Single-cell and spatial transcriptomics uncover the role of B chromosomes in driving plant invasiveness

Invasive plants pose a major threat to global biodiversity, yet the molecular and genomic mechanisms underlying their success remain poorly understood. Here, we investigate the common reed (Phragmites australis), a grass species that became invasive in North America after introduction from Europe, to unravel the molecular mechanisms of its invasiveness. By integrating single-cell RNA sequencing, spatial transcriptomics, and comparative genomics, we constructed a single-cell atlas of P. australis and identified 19 transcriptionally distinct cell types, including shoot apical meristem, epidermal, and vascular tissues. Comparative analysis of common garden-grown native (European) and invasive (North American) populations revealed a significant proportion of differentially expressed genes (DEGs) located on B chromosomes, which underwent copy number expansion in invasive genomes. The proportion of B chromosome genes in DEGs varies across cell types, with the highest proportions observed in the epidermis and mesophyll, and lower proportions in the vascular tissues. Gene IMPA-3, a B chromosome gene likely derived from transposable element activity, exhibited an elevated mutation rate compared to its ancestral counterparts, potentially enhancing adaptive evolution in invasive populations. Invasive individuals also displayed molecular regulatory networks related to photosynthetic efficiency, stress tolerance, and growth-defense trade-offs. Together, our findings provide a cell-type-resolved molecular atlas of a non-model invasive plant and offer key insights into the cellular and genomic architecture of plant invasiveness, with implications for ecological management.

evolutionary biology↗

MATING FREQUENCY MEDIATES PERSONALITY EXPRESSION IN FACULTATIVELY POLYANDROUS MITES

Animal personalities are characterized by within-individual consistency linked to among-individual variability. Personality expression may change during ontogeny and is often dependent on major life history transitions and events such as mating and the onset of reproduction. While the influence of female personalities on sexual selection and mating has long been known, the influence of the females mates on female personality expression after mating is poorly understood. Here we hypothesized that in facultatively polyandrous animals multiple mating increases the females assets, also called the residual reproductive value (RRV), due to direct and/or indirect benefits. Based on the predictions of the asset protection principle, higher RRV should promote behaviors that reduce the risk of fitness loss and hence mediate behavioral repeatability displayed in groups. We tested our hypothesis in the group-living, plant-inhabiting predatory mite Phytoseiulus persimilis. To this end, predatory mite females were presented with either a single mate or two mates in sequence and their post-mating repeatability in activity and sociability was evaluated in groups that were composed of females of the same and mixed mating types (monandrous and polyandrous). Mating frequency had little effects on activity patterns but pronounced effects on sociability traits. Polyandrous females were on average more sociable as well as more repeatable in sociability than monandrous females. These behavioral shifts reflect greater risk aversion and strategies to mitigate inter-individual conflicts within groups to enhance asset protection. Our study suggests that the mating frequency can critically influence female personality expression after mating in facultatively polyandrous animals and highlights the importance of considering mate-related variables in animal personality research.

animal behavior and cognition↗

SenSet, a novel human lung senescence cell gene signature, identifies cell-specific senescence mechanisms

Cellular senescence is a major hallmark of aging. Senescence is defined as an irreversible growth arrest observed when cells are exposed to a variety of stressors including DNA damage, oxidative stress, or nutrient deprivation. While senescence is a well-established driver of aging and age-related diseases, it is a highly heterogeneous process with significant variations across organisms, tissues, and cell types. The relatively low abundance of senescence in healthy aged tissues represents a major challenge to studying senescence in a given organ, including the human lung. To overcome this limitation, we developed a Positive-Unlabeled (PU) learning framework to generate a comprehensive senescence marker gene list in human lungs (termed SenSet) using the largest publicly available single-cell lung dataset, the Human Lung Cell Atlas (HLCA). We validated SenSet in a highly complex ex vivo human 3D lung tissue culture model subjected to the senescence inducers bleomycin, doxorubicin, or irradiation, and established its sensitivity and accuracy in characterizing senescence. Using SenSet, we identified and validated cell-type specific senescence signatures in distinct lung cell populations upon aging and environmental exposures. Our study presents the first comprehensive analysis of senescent cells in the healthy aging lung and uncovers cell-specific gene signatures of senescence, presenting fundamental implications for our understanding of major lung diseases, including cancer, fibrosis, chronic obstructive pulmonary disease, or asthma.

genomics↗

Pharmacophore-constrained de novo drug design with diffusion bridge

De novo design of bioactive drug molecules with potential to treat desired biological targets is a profound task in the drug discovery process. Existing approaches tend to leverage the pocket structure of the target protein to condition the molecule generation. However, even the pocket area of the target protein may contain redundant information since not all atoms in the pocket is responsible for the interaction with the ligand. In this work, we propose PharmacoBridge, a phamacophore-guided de novo design approach to generate drug candidates inducing desired bioactivity via diffusion bridge. Our method adapts the diffusion bridge to effectively convert pharmacophore arrangements in the spatial space into molecular structures under the manner of SE(3) -equivariant transformation, providing sophisticated control over optimal biochemical feature arrangements on the generated molecules. PharmacoBridge is demonstrated to generate hit candidates that exhibit high binding affinity with potential protein targets.

bioinformatics↗

Differential roles of NaV1.2 and NaV1.6 in neocortical pyramidal cell excitability

Mature neocortical pyramidal cells functionally express two sodium channel (NaV) isoforms: NaV1.2 and NaV1.6. These isoforms are differentially localized to pyramidal cell compartments, and as such are thought to contribute to different aspects of neuronal excitability. But determining their precise roles in pyramidal cell excitability has been hampered by a lack of tools that allow for selective, acute block of each isoform individually. Here, we leveraged aryl sulfonamide-based molecule (ASC) inhibitors of NaV channels that exhibit state-dependent block of both NaV1.2 and NaV1.6, along with knock-in mice with changes in NaV1.2 or NaV1.6 structure that prevents ASC binding. This allowed for acute, potent, and reversible block of individual isoforms that permitted dissection of the unique contributions of NaV1.2 and NaV1.6 in pyramidal cell excitability. Remarkably, block of each isoform had contrasting--and in some situations, opposing--effects on neuronal action potential output, with NaV1.6 block decreasing and NaV1.2 block increasing output. Thus, NaV isoforms have unique roles in regulating different aspects of pyramidal cell excitability, and our work may help guide development of therapeutics designed to temper hyperexcitability through selective NaV isoform blockade.

neuroscience↗

Clathrins are involved in the endocytosis of host cytosol in the malaria parasite

In eukaryotic cells, clathrins interact with adaptor protein complexes to regulate key intracellular trafficking events. Specifically, they are associated with the adaptor protein (AP) complex-2 (AP2) to facilitate endocytosis and AP1 to mediate secretion and trafficking between endosome and Golgi. In Plasmodium falciparum, recent studies revealed that the Kelch domain-containing protein 13 and AP2 participate in hemoglobin uptake via cytostomes. However, clathrins appear not to be involved in this process because they primarily associate with AP1. To investigate the roles of clathrins in P. falciparum, we characterized the clathrin heavy chain (PfCHC), the clathrin light chain (PfCLC), and the AP1 {gamma} subunit (PfAP1 {gamma}). Extensive interactome analyses confirmed the major association of clathrins with AP1 components alongside proteins involved in cytostome formation. Live-cell imaging and protein colocalization studies showed that PfCHC, PfCLC, and PfAP1 {gamma} are localized in the parasite cytoplasm, predominantly at the parasite periphery and near the cis-Golgi. Ultrastructural studies using ascorbate peroxidase 2- based electron microscopy confirmed their presence at coated vesicle-like structures at the parasite periphery and, unexpectedly, at the collars of cytostomes. Consistent with these observations, the knockdown of PfCHC led to the formation of abnormally long cytostome tubes and impaired hemoglobin digestion. This study demonstrates that clathrins are essential for proper cytostome formation in P. falciparum, highlighting their critical role in the parasites hemoglobin uptake and digestion processes. IMPORTANCEMalaria is still one of the most severe public health problems worldwide and understanding how malaria parasites obtain hemoglobin from their host cells, red blood cells (RBCs), is critical for identifying targets for antimalarials. In this study, affinity purification revealed that clathrins (PfCHC and PfCLC) were not only mainly associated with AP1 complex but also marginally interacted with proteins that participated in hemoglobin uptake. Localization analysis demonstrated that clathrins and AP1 coated the clusters of vesicles at the parasite periphery and at the neck of the cytostome, an organelle for hemoglobin uptake. Consistently, the knockdown of PfCHC caused the formation of abnormally long cytostome tubes and reduced hemoglobin digestion. Collectively, this study demonstrates that clathrins play a critical role in the parasites hemoglobin uptake.

microbiology↗

Behavioral and metabolic effects of extended hippocampal overexpression of the myokine Irisin in an Alzheimers Disease mouse model

Lifestyle interventions such as exercise are promising strategies to reduce the detrimental effects faced by aging populations. In particular, the exercise-induced myokine Irisin could act as a mediator of the positive effects of exercise, even as a potential therapeutic option for Alzheimers disease (AD). However, the fundamental roles of Irisin in counteracting AD neuropathology and other effects have not been fully determined. In addition, whether centrally produced Irisin has any effects is unclear. Here we examined the neurobehavioral effects of overexpressing Irisin directly in the hippocampus of an AD transgenic mouse line (TgCRND8), using adult male mice stereotaxically injected with Irisin-AAV vector. To further mimic chronic exercise, spatial memory and exploratory behaviors were assessed using the novel object recognition (NOR)/open field test (OFT) and Y-Maze tests after 8 weeks. Our results showed that Irisin expression led to several behavioral changes, including increased grooming behavior and slightly improved spatial memory performance in short interval NOR test in Tg mice. In the Y-Maze test however, we observed an increase in time spent in familiar spaces, which could indicate heightened anxiety-like behaviors in mice injected with Irisin-AAV. In addition, we observed significant differences in body and liver size, and in circulating metabolites such as ketone bodies, that were differentially regulated in NTg or Tg mice. Overall, our findings show important neurobehavioral effects of long-lasting overexpression of the exerkine Irisin in the hippocampus. Our results also raise questions about potential detrimental effects and thus warrant further studies to fully dissect how this exercise mediator affects the brain.

neuroscience↗

Genomic Insights into Hybridization and Speciation of Mitten Crabs in the Eriocheir Genus

Hybridization is a prominent and influential phenomenon with significant implications for adaptive evolution, species distribution and biodiversity. However, the intricacies of how hybridization influences genomic structure and facilitates adaptive evolution still elude our full understanding. Analyzing whole genome data from seven populations within Eriocheir genus across diverse geographic regions, we have validated a complex hybridization history between Chinese and Japanese mitten crabs. This hybridization gave rise to two distinct ecological species: Hepu and Russian mitten crabs with unique genomic architectures and adaptations. Genes related to reproduction, development, and temperature adaptation exhibit divergent selection signals, potentially contributing to their phenotypic diversity and ecological niches. Meanwhile, genes associated with reproduction, namely Birc6, Bap31, and Poxn, displayed robust evidence of selective sweeps in Hepu mitten crab. Notably, the favored alleles for these genes originated from the parental lineages during the hybridization process. Furthermore, Hepu mitten crab is a homoploid hybrid species that originated from an ancient hybridization event, resolving its longstanding taxonomic controversy. Our study sheds light on the evolutionary history of mitten crabs and highlights the crucial role of hybridization in driving adaptation, range expansion, and diversification within the Eriochier genus.

genomics↗

A Novel Bispecific Antibody CVL006 Superior to AK112 for Dual Targeting of PD-L1 and VEGF in Cancer Therapy

Both preclinical and clinical studies have shown that combining anti-VEGF/VEGFR drugs with immune checkpoint inhibitors (ICIs) significantly enhances anticancer efficacy. Currently, PDL-1/ VEGF bispecific antibodies demonstrate superior antitumor activity compared to monotherapy or even the combination of PD-L1 inhibitors with anti-VEGF antibodies. This enhanced efficacy results from the simultaneous blockade of the PD-1/PD-L1 pathway and the inhibition of VEGF-driven angiogenesis. In this study, we developed a novel bispecific antibody, CVL006, by fusing an anti-PDL1 VHH domain with a humanized IgG1 anti-VEGF monoclonal antibody while retaining antibody-dependent cellular cytotoxicity (ADCC) functionality. CVL006 demonstrated high affinity and specificity for both human PD-L1 and VEGF, effectively blocking both the VEGF/VEGFR signaling pathway and the PD-L1/PD-1 axis. This dual blockade not only suppressed VEGF-induced angiogenesis but also reactivated T cells, increasing the secretion of cytokines essential for immune response. In vivo studies further indicated that CVL006 achieved superior antitumor efficacy compared to the PD-L1 inhibitor atezolizumab in mouse models, with greater tumor growth inhibition and reduced angiogenesis. To compare with approved bispecific antibody PD-1/VEGF AK112 (ivonescimab), CVL006 showed superior antitumor efficacy in vivo. These findings underscore the therapeutic potential of CVL006, which integrates immune checkpoint inhibition with disruption of tumor vascularization, offering a robust and comprehensive anticancer strategy.

pharmacology and toxicology↗

Inhibiting heme-piracy by pathogenic Escherichia coli using de novo-designed proteins

Iron is an essential nutrient for most bacteria and is often growth-limiting during infection, due to the host sequestering free iron as part of the innate immune response. To obtain the iron required for growth, many bacterial pathogens encode transporters capable of extracting the iron-containing cofactor heme directly from host proteins. Pathogenic E. coli and Shigella spp. produce the outer membrane transporter ChuA, which binds host hemoglobin and extracts its heme cofactor, before importing heme into the cell. Heme extraction by ChuA is a dynamic process, with the transporter capable of rapidly extracting heme from hemoglobin in the absence of an external energy source, without forming a stable ChuA-hemoglobin complex. In this work, we utilise a combination of structural modelling, Cryo-EM, X-ray crystallography, mutagenesis, and phenotypic analysis to understand the mechanistic detail of this process. Based on this understanding we utilise artificial intelligence-based protein design to create binders capable of inhibiting E. coli growth by blocking hemoglobin binding to ChuA. By screening a limited number of these designs, we identify several binders that inhibit E. coli growth at low nanomolar concentrations, without experimental optimisation. We determine the structure of a subset of these binders, alone and in complex with ChuA, demonstrating that they closely match the computational design. This work demonstrates the utility of de novo-designed proteins for inhibiting bacterial nutrient uptake and uses a workflow that could be applied to integral membrane proteins in other organisms.

biochemistry↗

Flavivirus NS1-triggered endothelial dysfunction promotes virus dissemination

The Flaviviridae are a family of viruses that include the important arthropod-borne human pathogens dengue virus (DENV), West Nile virus, Zika virus, Japanese encephalitis virus, and yellow fever virus. Flavivirus nonstructural protein 1 (NS1) is essential for virus replication but is also secreted from virus-infected cells. Extracellular NS1 acts as a virulence factor during flavivirus infection in multiple ways, including triggering endothelial dysfunction and vascular leak via interaction with endothelial cells. While the role of NS1 in inducing vascular leak and exacerbating pathogenesis is well appreciated, if and how NS1-triggered endothelial dysfunction promotes virus infection remains obscure. Flaviviruses have a common need to disseminate from circulation into specific tissues where virus-permissive cells reside. Tissue-specific dissemination is associated with disease manifestations of a given flavivirus, but mechanisms dictating virus dissemination are unclear. Here we show that NS1-mediated endothelial dysfunction promotes virus dissemination in vitro and in vivo. In mouse models of DENV infection, we show that anti-NS1 antibodies decrease virus dissemination, while the addition of exogenous NS1 promotes virus dissemination. Using an in vitro system, we show that NS1 promotes virus dissemination in two distinct ways: (1) promoting crossing of barriers and (2) increasing infectivity of target cells in a tissue- and virus-specific manner. The capacity of NS1 to modulate infectivity correlates with a physical association between virions and NS1, suggesting a potential NS1-virion interaction. Taken together, our study indicates that flavivirus NS1 promotes virus dissemination across endothelial barriers, providing an evolutionary basis for virus-triggered vascular leak. Author SummaryThe Flaviviridae contain numerous medically important human pathogens that cause potentially life-threatening infections. Over half of the worlds population is at risk of flavivirus infection, and this number is expected to increase as climate change expands the habitats of the arthropod vectors that transmit these flaviviruses. There are few effective vaccines and no therapeutics approved for prevention or treatment of flavivirus infection, respectively. Given these challenges, understanding how and why flaviviruses cause pathogenesis is critical for identifying targets for therapeutic intervention. The secreted nonstructural protein 1 (NS1) of flaviviruses is a conserved virulence factor that triggers endothelial dysfunction in a tissue-specific manner. It is unknown if this endothelial dysfunction provides any benefit for virus infection. Here we provide evidence that NS1-triggered endothelial dysfunction facilitates virus crossing of endothelial barriers and augments infection of target cells in vitro and promotes virus dissemination in vivo. This study provides an evolutionary explanation for flaviviruses evolving the capacity to trigger barrier dysfunction and highlights NS1 and the pathways governing endothelial dysfunction, as therapeutic targets to prevent flavivirus dissemination.

microbiology↗

Design of high specificity binders for peptide-MHC-I complexes

Class I MHC molecules present peptides derived from intracellular antigens on the cell surface for immune surveillance, and specific targeting of these peptide-MHC (pMHC) complexes could have considerable utility for treating diseases. Such targeting is challenging as it requires readout of the few outward facing peptide antigen residues and the avoidance of extensive contacts with the MHC carrier which is present on almost all cells. Here we describe the use of deep learning-based protein design tools to de novo design small proteins that arc above the peptide binding groove of pMHC complexes and make extensive contacts with the peptide. We identify specific binders for ten target pMHCs which when displayed on yeast bind the on-target pMHC tetramer but not closely related peptides. For five targets, incorporation of designs into chimeric antigen receptors leads to T-cell activation by the cognate pMHC complexes well above the background from complexes with peptides derived from proteome. Our approach can generate high specificity binders starting from either experimental or predicted structures of the target pMHC complexes, and should be widely useful for both protein and cell based pMHC targeting.

immunology↗

Sirt5 preserves cardiac function in ischemia-reperfusion injury by inhibiting ANT2 lactylation

Myocardial ischemia-reperfusion (IR) injury is the most common type of heart disease. IR-disrupted mitochondrial homeostasis affects heart energy metabolism and function, but the mechanism remains poorly understood. Here we report a cardioprotective role of the mitochondrial protein Sirt5 in a mouse model of cardiac IR injury. The down-regulation of Sirt5 in IR-injured heart is associated with an increased protein lactylation and impaired mitochondrial function. Overexpression of Sirt5 alleviates, whereas conditional knockout of Sirt5 aggravates, mitochondrial damage and cardiac injury. Mechanistically, Sirt5 interacts with the inner mitochondrial membrane protein adenine nucleotide translocase 2 (ANT2), inhibiting its lysine lactylation to promote its association with the outer mitochondrial membrane protein voltage-dependent anion-selective channel 1 (VDAC1). Lactylation-resistant ANT2 efficiently complexes with VDAC1 and improves cardiac function after injury. Therefore, we uncover a Sirt5-regulated interaction of ANT2 and VDAC1 in maintaining mitochondrial homeostasis, highlighting the potential of targeting ANT2 lactylation as a therapeutic strategy in the treatment of cardiac injury. TeaserSirt5 promotes the interaction of mitochondrial proteins to protect mitochondrial homeostasis and improve heart function in ischemia-reperfusion injury.

pathology↗

RetS senses neurotransmitter norepinephrine and adrenergic agents to regulate Pseudomonas aeruginosa virulence

Bacterial cells employ diverse mechanisms to perceive and respond to host-associated molecules, coordinate intracellular signal transduction, and engage in interkingdom communications. In this study, we firstly discovered that the adrenergic antagonist dronedarone (DDR) effectively suppresses quorum sensing (QS) and pathogenesis of the opportunistic pathogen P. aeruginosa. Further analysis revealed that DDR targets RetS, an bacterial surface receptor critical for suppressing the GacS/GacA two-component regulatory system (TCS). Interestingly, the adrenergic agonist norepinephrine (NE) was found to exert opposite effects against RetS, thereby reversing DDR-induced phenotypes in P. aeruginosa. Moreover, we identified the hinge region of RetSDISMED2 serves as a binding pocket of NE and DDR, which provides potential mechanisms of the antagonistic effect of NE and DDR. Our study demonstrated that NE promotes P. aeruginosa infections while DDR can serve as an anti-virulence compound against P. aeruginosa infections. Thus, RetS might serve as a bacterial adrenergic receptor which keeps the NE under constant surveillance. SignificanceSensing and recognition of host-derived molecules, as well as therapeutic drugs, are crucial for the survival of pathogens during infection process. The adrenergic drugs are well known to affect virulence and pathogenesis of the opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa). In this work, we have provided in-depth characterization of a Norepinephrine (NE) receptor in P. aeruginosa, the RetS membrane protein. NE is the-adrenergic agonist known as a stress hormone, exerts its activity through interaction with mammalian adrenergic receptors (AR). It has been shown that increased NE concentration during early sepsis can stimulate the growth of various Gram-negative and Gram-positive bacteria, including P. aeruginosa. We revealed that both adrenergic agonist NE and another adrenergic antagonist dronedarone (DDR) are able to interfering the RetS-GacS/GacA signaling cascade of P. aeruginosa and execute opposite impact on the pathogenesis of P. aeruginosa during infections.

microbiology↗