Biology subjects

Wu, H.

Publications and source records attributed to Wu, H..

At least 199 records · Page 11Linked to original sources

bioRxiv2024

Regulation of tmTNF-α Processing by FRMD8 in Triple-Negative Breast Cancer Metastasis: Insights into Molecular Pathway Dynamics

PurposeBreast cancer remains the leading cause of cancer-related mortality among women worldwide, with late-stage diagnoses prevalent in China resulting in significantly lower survival rates. This study focuses on identifying genes implicated in breast cancer metastasis, highlighting the role of Tumor Necrosis Factor-alpha (TNF-) and its forms--transmembrane (tmTNF-) and soluble (sTNF-). Experimental DesignTNF- is crucial for activating NF-{kappa}B pathways that regulate genes involved in cell adhesion, migration, and immune evasion, all essential for cancer metastasis. We conducted comprehensive analyses of FRMD8, a member of the FERM domain-containing proteins, as a significant regulator of tmTNF-. Through integrative multi-omics and cellular functional studies, the relationship between FRMD8, iRhom2, and ADAM17 was assessed in the context of breast cancer metastasis. ResultsOur findings reveal that FRMD8 forms a complex with iRhom2 and ADAM17, enhancing the stability and sheddase activity of ADAM17, which is vital for the release of TNF-. The absence of FRMD8 leads to decreased ADAM17 activity, increasing the availability of tmTNF- and potentially promoting metastasis. This effect suggests that FRMD8 is a key modulator of TNF- processing. ConclusionsThis study explores how FRMD8 influences TNF- processing and the metastatic behavior of breast cancer, providing insights into molecular dynamics that could guide future therapeutic strategies to improve outcomes in breast cancer patients.

cancer biology↗

bioRxiv2024

GPR30 in spinal cholecystokinin-positive neurons modulates neuropathic pain via mediating descending facilitation

Neuropathic pain, a major health problem affecting 7-10% of the global population, lacks effective treatment due to its elusive mechanisms. Cholecystokinin-positive (CCK+) neurons in the spinal dorsal horn (SDH) are critical for neuropathic pain, yet the underlying molecular mechanisms remain unclear. Here, we show that the membrane estrogen receptor G-protein coupled estrogen receptor (GPER/GPR30) in spinal neurons was significantly upregulated in chronic constriction injury (CCI) mice and that inhibition of GPR30 in CCK+ neurons reversed CCI-induced neuropathic pain. Furthermore, GPR30 in spinal CCK+ neurons was essential for the enhancement of AMPA-mediated excitatory synaptic transmission in CCI mice. Moreover, GPR30 was expressed in spinal CCK+ neurons that received direct projection from the primary sensory cortex (S1-SDH). Chemogenetic inhibition of S1-SDH post-synaptic neurons alleviated CCI-induced neuropathic pain. Conversely, chemogenetic activation of these neurons mimicked neuropathic pain symptoms, which were attenuated by spinal inhibition of GPR30. Finally, we confirmed that GPR30 in S1-SDH post-synaptic neurons was required for CCI-induced neuropathic pain. Taken together, our findings suggest that GPR30 in spinal CCK+ neurons and S1-SDH postsynaptic neurons is pivotal for neuropathic pain, thereby representing a promising therapeutic target for neuropathic pain.

neuroscience↗

bioRxiv2024

Rfx3 controls outer hair cell differentiation, maintenance, and hair bundle formation by regulating the expression of Insm1, Ikzf2, and Triobp genes

The RFX family of transcription factors plays crucial roles in the regulation of ciliogenesis and organ development. Mutations of RFX transcription factors lead to various genetic diseases, including ciliopathies and hearing loss, although the underlying mechanisms remain unclear. This study comprehensively analyzed the expression patterns of RFX family members during different inner ear developmental stages. Rfx3 and Rfx7 were identified as the dominantly expressed members in cochlear hair cells, exhibiting alternative splicing variants and dynamic subcellular localization at different stages. Integration of single-cell transcriptomics, ChIP-seq, and ATAC-seq data indicates that Rfx3 functions as either a transcriptional activator or repressor, binding to numerous genes related to ciliogenesis, hair bundle structures, and planar cell polarity. Rfx3 regulates the spatiotemporal expression of hair bundle gene Triobp in hair cells by binding to and modulating its intronic enhancer. Additionally, Rfx3 binds to hair cell differentiation and fate determination genes Tbx2, Insm1, and Ikzf2. The results demonstrate that Rfx3 and Rfx7 are dominantly expressed in outer hair cells, with their subcellular localization shifting to cytoplasm at later developmental stages. This suggests a previously unknown function of Rfx3 and Rfx7 beyond transcriptional regulation, highlighting their complex roles in hair cell differentiation and maintenance.

developmental biology↗

bioRxiv2024

Epigenomic analysis of hepatocellular carcinoma reveals aberrant cis-regulatory changes and dysregulated retrotransposons with prognostic potentials

Hepatocellular carcinoma (HCC) exhibits widespread epigenetic alterations, yet their impact on cis-regulatory elements (CREs) and retrotransposons remains poorly understood. Here, we present an integrated epigenomic and transcriptomic analysis of HCC tumors and matched tumor-adjacent normal tissues. We identified extensive DNA hypomethylation coupled with changes in histone modifications at partially methylated domains, CREs, and retrotransposons. These epigenetic aberrations were associated with dysregulated expression of genes involved in cell cycle regulation, immune response, and extracellular matrix organization. Notably, our findings revealed a novel mechanism for the transcriptional dysregulation of GPC3, a key HCC biomarker and immunotherapeutic target. We observed that GPC3 upregulation is driven by both the reactivation of a fetal liver super enhancer and hypomethylation of GPC3-associated CpG islands. Moreover, we found that DNA hypomethylation-driven aberrant expression of retrotransposons carries prognostic significance in HCC. Patients with high expression of a long non-coding RNA driven by a HERVE-int element exhibited more aggressive tumors, poorer clinical outcomes, and molecular features associated with favorable immunotherapy response. Together, our study provides a comprehensive resource for understanding the role of epigenetic dysregulation in HCC and identifies retrotransposon-associated transcripts as potential biomarkers.

genomics↗

bioRxiv2024

Human NLRP3 inflammasome activation leads to formation of condensate at the microtubule organizing center

The NLRP3 inflammasome is a multi-protein molecular machine that mediates inflammatory responses in innate immunity. Its dysregulation has been linked to a large number of human diseases. Using cryogenic fluorescence-guided focused-ion-beam (cryo-FIB) milling and electron cryo-tomography (cryo-ET), we obtained 3-D images of the NLRP3 inflammasome in situ at various stages of its activation at macromolecular resolution. The cryo-tomograms unexpectedly reveal dense condensates of the human macrophage NLRP3 inflammasome that form within and around the microtubule organizing center (MTOC). We also find that following activation, the trans-Golgi network disperses and 50-nm NLRP3-associated vesicles appear which likely ferry NLRP3 to the MTOC. At later time points after activation, the electron-dense condensates progressively solidify and the cells undergo pyroptosis with widespread damaged mitochondria and autophagasomal structures.

immunology↗

bioRxiv2024

A benchmarking study of copy number variation inference methods using single-cell RNA-sequencing data

Single-cell RNA-sequencing (scRNA-seq) has emerged as a powerful tool for cancer research, enabling in-depth characterization of tumor heterogeneity at the single-cell level. Recently, scRNA-seq copy number variation (scCNV) inference methods have been developed, expanding the application of scRNA-seq to study genetic heterogeneity in cancer using transcriptomic data. However, the fidelity of these methods has not been investigated systematically. In this study, we benchmarked five commonly used scCNV inference methods, HoneyBADGER, CopyKAT, CaSpER, inferCNV, and sciCNV. We evaluated their performance across four different scRNA-seq platforms derived data from a multicenter study. We further evaluated the scCNV performance using scRNA-seq datasets derived from mixed samples consisting of five human lung adenocarcinoma cell lines and generated a clinical scRNA-seq dataset from a human small cell lung cancer patient to validate our findings. Our evaluation criteria included sensitivity and specificity of CNV detection, and subclone identification from mixed cancer samples. We found that the sensitivity and specificity of the five scCNV inference methods varied, depending on the selection of reference data, sequencing depths, and read lengths. Overall, CopyKAT and CaSpER exhibited superior performance to other methods, while inferCNV, sciCNV, and CopyKAT outperformed other methods in subclone identification accuracy. Remarkably, inferCNV achieved high accuracy in subclone identification when using data from a "single scRNA-seq protocol", however, when applying these methods to a dataset derived from multiple scRNA-seq platforms from the mixed samples, we found that batch effects significantly affected the performance of subclone identification for most methods, except for HoneyBADGER. Our benchmarking study revealed the strengths and weaknesses of each of the five scCNV inference methods and provided guidance for selecting the optimal CNV inference method using scRNA-seq data.

bioinformatics↗

bioRxiv2024

G3BP1 Maintains Vascular Endothelial Barrier Integrity by Negatively Regulating the MYD88-ARNO-ARF6 Signaling Pathway

Endothelial permeability is essential for vascular function. This process is regulated by intercellular junctions, including adherens junctions (AJs) and tight junctions (TJs), which form the endothelial barrier and dynamically connect adjacent cells. However, the mechanisms that control endothelial permeability are not fully understood. We investigated the role of the RNA-binding protein G3BP1 in regulating endothelial permeability. We examined the effects of Loss of g3bp1 in conditional knockout mice and primary human HUVEC cells. We analyzed endothelial barrier integrity and permeability, focusing on AJ and TJ expression, under both normal and LPS-induced inflammatory conditions. Loss of g3bp1 in vascular endothelial cells decreased AJ and TJ expression, compromised barrier integrity, and increased permeability. These effects were exacerbated under LPS-induced inflammatory conditions. Loss of g3bp1 also increased the expression of MYD88, ARNO, and ARF6, and enhanced ARF6 activity. Mechanistically, G3BP1 bound to and stabilized MYD88 mRNA, negatively regulating the MYD88-ARNO-ARF6 signaling pathway. Inhibiting this pathway by reducing MYD88 or ARF6 expression, or inhibiting ARNO activity, restored AJ/TJ expression and barrier function in G3BP1-deficient models. Our findings identify G3BP1 as a novel regulator of vascular endothelial permeability. G3BP1 acts by negatively regulating the MYD88-ARNO-ARF6 signaling pathway. Targeting G3BP1 may be a potential therapeutic strategy for diseases associated with endothelial barrier dysfunction.

physiology↗

bioRxiv2024

Endogenous retroviruses activate MARCO-mediated inflammatory response to block retroviral infection

Endogenous retroviruses (ERVs) are remnants of ancient retroviral infections and can profoundly affect the host antiviral innate immune response, although the mechanisms by which these changes occur are largely unknown. Here we report that chicken-specific ERVs exert genetic resistance to exogenous retrovirus infection. Mechanistically, chicken-specific ERVs activated the scavenger receptor MARCO (macrophage receptor with collagenous structure)-mediated TLR3-IL-1{beta} inflammatory response in macrophages. Under the presence of MARCO, macrophages response to viral infection through inducing TLR3-IL-1{beta} inflammatory response. Conversely, lack of MARCO increased the viral replication levels and attenuated the antiviral inflammatory response. MARCO-mediated ligand delivery enhances TLR3-IL-1{beta} antiviral response, and IL-1{beta} expression is responsible for viral inhibition. Restoring MARCO or IL-1{beta} expression overcomes viral infection in macrophages. Our study provides new insights into the molecular mechanisms underlying the host defense against exogenous retroviruses infection and may have important implications for the development of novel therapeutic strategies against retroviruses infection.

immunology↗

bioRxiv2024

Novel Role of Endothelial CD45 in Regulating Endothelial-to-Mesenchymal Transition in Atherosclerosis

BackgroundThe protein tyrosine phosphatase CD45 is expressed in all nucleated cells of the hematopoietic system and in mitral valve endothelial cells (ECs) undergoing endothelial-to-mesenchymal transition (EndoMT). Our recent work indicated that activation of endogenous CD45 in human endothelial colony-forming cells (ECFCs) induced expression of multiple EndoMT marker genes. We hypothesized that CD45 may contribute to atherosclerosis; however, detailed molecular mechanisms underlying how CD45 may contribute to EndoMT and the impact of therapeutic manipulation of CD45 expression in atherosclerosis are unknown. MethodsWe generated a tamoxifen-inducible EC-specific CD45-deficient mouse strain (EC-iCD45KO) on an ApoE-deficient (WT/ApoE-/-) background and fed them a Western diet (WD) to produce atherosclerosis. We enriched mouse aortic ECs with anti-CD31 beads to perform single-cell RNA sequencing. Cellular, biochemical and molecular approaches were used to investigate the effect of endothelial CD45-specific deletion on EndoMT and lesion development in an ApoE-/- mouse model of atherosclerosis. ResultsEC-iCD45KO mice showed reductions in lesion development, plaque macrophage infiltration, and expression of cell adhesion molecules when compared to WT/ApoE-/- controls. Single-cell RNA sequencing revealed that loss of endothelial CD45 decreases EndoMT marker expression and TGF-{beta} signaling in atherosclerotic mice, which is associated with reduction of lesions. Mechanistically, CD45 loss increases Fibroblast Growth Factor Receptor 2 (FGFR2) expression in mouse aortic ECs and Kruppel-like Factor 2 (KLF2) expression in the aortic root. Endothelial CD45-deficiency also inhibits EndoMT and TGF{beta} signaling in atherosclerosis. ConclusionsOur findings demonstrate that genetic depletion of endothelial CD45 protects against EndoMT-driven atherosclerosis by promoting FGFR2 and KLF2 expression while inhibiting Transforming Growth Factor beta (TGF{beta}) signaling and EndoMT. Consequently, targeting endothelial CD45 may represent a novel therapeutic strategy to reduce EndoMT in atherosclerosis.

cell biology↗

bioRxiv2024

Targeting Liver Epsins Ameliorates Dyslipidemia in Atherosclerosis

BackgroundThe low-density lipoprotein receptor (LDLR) in the liver plays a crucial role in clearing low-density lipoprotein cholesterol (LDL-C) from the bloodstream. This process takes place mainly in the liver. Under atherogenic conditions, Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9), secreted by the liver, binds to LDLR on hepatocytes, preventing its recycling and enhancing its lysosomal degradation. This process reduces LDL-C clearance, promoting hypercholesterolemia. Epsins, a family of ubiquitin-binding endocytic adaptors, are key regulators of atherogenesis in lesional cells, including endothelial cells and macrophages. Given epsins canonical role in regulating endocytosis of cell surface receptors, we aimed to determine whether and how liver epsins contribute to PCSK9-mediated LDLR endocytosis and degradation, thereby impairing LDL-C clearance and accelerating atherosclerosis. MethodsLiver-specific epsin knockout (Liver-DKO) atherosclerotic models were generated in ApoE-/- and PCSK9-AAV8-induced atheroprone mice fed on a Western diet. We utilized single-cell RNA sequencing, along with molecular, cellular, and biochemical analyses, to investigate the physiological role of liver epsins in PCSK9-mediated LDLR degradation. Additionally, we explored the therapeutic potential of nanoparticle-encapsulated siRNAs targeting epsins 1 and 2 in ApoE-/- mice with established atherosclerosis. ResultsWestern diet (WD)-induced atherosclerosis was significantly attenuated in ApoE-/-/Liver-DKO mice compared with ApoE-/- controls, as well as in PCSK9-AAV8-induced Liver-DKO mice compared with PCSK9-AAV8-induced wild-type (WT) mice accompanied by reductions in blood cholesterol and triglyceride levels. Mechanistically, single-cell RNA sequencing of hepatocytes and aortas isolated from atherosclerotic ApoE-/- and ApoE-/-/Liver-DKO mice revealed epsin-deficient Ldlrhi hepatocytes with diminished lipogenic potential. Notably, pathway analysis of hepatocytes showed increased LDL particle clearance and enhanced LDLR-cholesterol interactions under WD treatment in ApoE-/-/Liver-DKO mice compared with ApoE-/- controls, correlating with decreased plasma LDL-C levels. Furthermore, pathway analysis of the aortas showed attenuated inflammation and endothelial activation, coupled with reduced lipid uptake, and enhanced cholesterol efflux under WD treatment in ApoE-/-/Liver-DKO mice compared with ApoE-/- controls. Moreover, the absence of liver epsins led to an upregulation of LDLR protein expression in hepatocytes. We further demonstrated that epsins bind LDLR via the ubiquitin-interacting motif (UIM), enabling PCSK9-mediated LDLR degradation. Depleting epsins abolished this degradation, thereby preventing atheroma progression. Lastly, targeting liver epsins with nanoparticle-encapsulated epsins siRNAs effectively ameliorates dyslipidemia and inhibits atherosclerosis progression. These results are consistent with findings showing an increased epsin1 and epsin2 expression in atherosclerotic cardiovascular disease patients. ConclusionsLiver epsins drive atherogenesis by promoting PCSK9-mediated LDLR degradation, thereby elevating circulating LDL-C levels and heightening lesional inflammation. As such, targeting epsins in the liver represents a promising therapeutic strategy to mitigate atherosclerosis by preserving LDLR and enhancing LDL-C clearance in the liver.

cell biology↗

bioRxiv2024

Technical Assessment on Proteonano: A Robust Platform for Deep Plasma Proteomics Study

Complete profiling of human plasma proteome is an immerse source for disease biomarker discovery. Cutting-edge mass spectrometers, like ThermoFishers Orbitrap Astral, have promised unprecedented insights into the exploration of multiple protein biomarkers from human plasma samples. However, large-scale, deep profiling of the human plasma proteome, especially low-abundant proteins (LAPs, <10 ng.mL- 1), in a robust and fast way remains challenging. This is largely due to the lack of standardized and automated workflows including LAPs enrichment, reduction, and enzymatic digestion procedures. Until now, these complex procedures have not been incorporated into a streamlined workflow to achieve reproducibility, high-throughput, and deep proteome coverage. Here we report the Proteonano Ultraplex Proteomics (PUP) Platform for large cohort plasma proteomics studies with robustness and fast throughput by standardizing workflow by incorporating the Proteonano platform and high-resolution mass spectrometers, including Orbitrap Exploris 480, Orbitrap Astral, and timsTOF Pro. This pipeline demonstrates excellent stability and reproducibility, with tunable balance between proteome coverage and throughput. We further demonstrate the utility of this platform for potential biomarker discovery in a neurodegenerative disease cohort. This harmonized method enables robust, fast and large-cohort plasma proteomics studies to meet the need to discover new biomarkers.

biochemistry↗

bioRxiv2024

Intraperitoneal programming of tailored CAR macrophages via mRNA-LNP to boost cancer immunotherapy

Therapeutic strategies for peritoneal metastasis in solid tumors are urgently needed in the clinic. Programming chimeric antigen receptor macrophages (CAR-Ms) in situ offers opportunities for an unmet demand. However, potential intracellular domains (ICDs) for CAR design and their antitumor mechanisms for macrophage empowerment remain to be explored systematically. By developing a targeted mRNA-LNP delivery system for macrophages, we have investigated 36 CAR combinations to determine the impact of CAR-Ms on immune regulation in vitro and in vivo. In two solid tumor mouse models, intraperitoneal programming of CAR-Ms was shown to elicit robust adaptive immune activation and significantly synergize with PD-1/L1 therapy. Single-cell RNA sequencing (scRNA-seq) analysis revealed that CAR-Ms could reshape the immunosuppressive tumor microenvironment (TME) and boost the TCF1+PD-1+ progenitor- exhausted CD8+ T cells (Tpex) population. Meanwhile, we found that tailored CAR-M with CD3{zeta}/TLR4 ICDs could favorably maintain proinflammatory phenotype and simultaneously upregulate MHC I and PD-L1 expression by perturbing NF-{kappa}B pathways. Moreover, the synergism between macrophage PD-L1 knockdown and CAR-M therapy highlighted the need to block the PD-1/L1 axis in antigen cross-presentation. In short, we developed an mRNA-LNP delivery system for intraperitoneal programming of tailored CAR-Ms in vivo and broadened understanding of both regulatory and feedback mechanisms for CAR-M therapies against solid tumors.

bioengineering↗

bioRxiv2024

Efficient generation of CAR NK cells from human umbilical cord blood CD34+ stem and progenitors for democratizing affordable immunotherapy

Chimeric antigen receptor (CAR) natural killer cells (CAR NK) cells, leveraging safety and not requiring HLA match in adoptive infusion, have emerged as promising alternative cells to CAR-T cells for immunotherapies. High and multiple doses of CAR NK cell infusions are essential to maintain therapeutic efficacy in clinical trials. This requires efficient methods for generating large-scale CAR NK cells and significantly reducing CAR engineering costs. In this study, we develop a three-step strategy to generate highly high yields of induced NK (iNK) and CAR iNK cells from human umbilical cord blood CD34+ hematopoietic stem and progenitor cells (CD34+ HSPCs). Starting from a single umbilical cord blood CD34+ HSPC, our reliable method efficiently produces 14-83 million mature iNK cells or 7-32 million CAR iNK cells with high expression levels of CD16 and zero T cell contaminations. Introducing CAR expression elements at the HSPC level reduces the quantities of CAR pseudoviruses to 1 / 140.000 - 1 / 600,000 compared to engineering CARs in mature NK cells. The iNK and CAR iNK cells, including fresh cells and thawed cells from cryopreserved conditions, demonstrate remarkable tumoricidal activities against various human cancer cells and significantly prolong the survival of human tumor-bearing animals. The high yields of CAR NK cells and negligible costs of CAR engineering of our method support the broad applications of CAR NK cells for treating cancer patients.

cell biology↗

bioRxiv2024

A new regulator of sporulation sheds light on spore morphogenesis and ballistospory in mushroom-forming fungi

Sporulation is the most widespread means of reproduction and dispersal in fungi. In the Basidiomycota, sexual spores are produced on specialised cells known as basidia, from which they are discharged forcibly by a powered process called ballistospory, the highest known acceleration in nature. However, the genetics of sporulation, in particular postmeiotic events related to spore morphogenesis and ballistospory, remain poorly known. Here, we explore the genetics of these processes, based on a new, highly conserved transcription factor, Sporulation-Related Regulator 1 (SRR1), and its putative downstream regulatory network. Reverse genetics of Srr1 in the model mushroom Coprinopsis cinerea and commercially produced oyster mushroom indicated a conserved role of Srr1 in sporulation across Agaricomycetes. RNA-Seq analysis and motif-based inference of a hypothetical SRR1 gene regulatory network allowed delimiting putative targets regulated by SRR1 in a direct and indirect manner. Using this network and comparative genomics, we identified genes associated with ballistospory, including a putative SRR1-target chitinase, which was found to be required for normal spore production and morphology. Overall, our study offers new insights into the genetic mechanisms governing postmeiotic spore morphogenesis and ballistospory in the Agaricomycetes.

microbiology↗

bioRxiv2024

Telomere-to-telomere sheep genome assembly reveals new variants associated with wool fineness trait

Ongoing efforts to improve sheep reference genome assemblies still leave many gaps and incomplete regions, resulting in a few common failures and errors in sheep genomic studies. Here, we report a complete, gap-free telomere-to-telomere (T2T) genome of a ram (T2T-sheep1.0) with a size of 2.85 Gb, including all autosomes and chromosomes X and Y. It adds 220.05 Mb of previously unresolved regions (PURs) and 754 new genes to the most updated reference assembly, ARS-UI_Ramb_v3.0, and contains four types of repeat units (SatI, SatII, SatIII, and CenY) in the centromeric regions. T2T-sheep1.0 exhibits a base accuracy of >99.999%, corrects several structural errors in previous reference assemblies, and improves structural variant (SV) detection in repetitive sequences. We identified 192,265 SVs, including 16,885 new SVs in the PURs, from the PacBio long-read sequences of 18 global representative sheep. With the whole-genome short-read sequences of 810 wild and domestic sheep representing 158 global populations and seven wild species, the use of T2T-sheep1.0 as the reference genome has improved population genetic analysis based on [~]133.31 million SNPs and 1,265,266 SVs, including 2,664,979 novel SNPs and 196,471 novel SVs. T2T-sheep1.0 improves selective tests by detecting several novel genes and variants, including those associated with domestication (e.g., ABCC4) and selection for the wool fineness trait (e.g., FOXQ1) in tandemly duplicated regions.

genomics↗

bioRxiv2024

The Identification Markers of activated myofibroblast subsets in the Human Lung Fibrosis Ecosystem via integrated omics Analysis

BackgroundThe aberrant remodeling of the extracellular matrix (ECM) is closely associated with lung fibrosis. However, the mechanisms underlying ECM remodeling in pulmonary fibrosis (PF) remain unclear. The advent of single-cell RNA sequencing (scRNA-seq) has provided valuable insights into the diverse phenotypic and functional characteristics of human PF. Nevertheless, the dynamic of ECM remodeling in terms of ECM synthesizing and the potential activating markers of myofibroblasts in the human PF microenvironment still needs to be investigated. MethodsWe performed integrative scRNA-seq analyses on high-fidelity PF data from a public platform by filtering out the low-quality counts and doublets using two doublet prediction methods. Next, we investigated the dynamic of the ECM signature in diverse cells in PF and screened the potential markers of myofibroblasts via fitting a successful polynomial regression model. Finally, the markers of activated myofibroblasts were identified using bulk RNA-seq of pulmonary tissue. ResultsFirst, we depicted the pathogenic landscape and demonstrated the heterogeneity of ECM in PF by integratively analyzing single-cell RNA-seq data, and we hypothesized that myofibroblasts played a significant role in ECM formation. Second, our results successfully displayed the biological dynamic changes of ECM and investigated the 73 positive correlated genes of myofibroblasts in PF via a polynomial regression model. Then, the bulk RNA-seq results further identified eight new activating markers of myofibroblasts, such as MFAP2, MXRA5, and LRRC17 via transcriptomic signature, correlation and ROC scores. Finally, the results of cell-cell interaction indicated that myeloid cells may be involved in regulating ECM remodeling through proliferation mediated by myofibroblasts that secrete POSTN, suggesting that ECM remodeling in PF is a complex and multi-participated process. ConclusionsIn summary, we provided insights into the contributions of ECM in human PF by integrative analysis and highlighted potential clinical utilities of myofibroblast subsets as therapeutic targets.

bioinformatics↗

bioRxiv2024

Carbon Dots and Single-walled Carbon Nanotubes Enhances Maize Shading Stress Tolerance

Low sunlight availability/shading stress is one of the major abiotic stresses, limiting plant photosynthesis and biomass production. Maize is a C4 species and requires more sunshine for efficient photosynthesis rate. Thus, maize is a highly shade-sensitive species. We used carbon dots (CDs) and single-walled carbon nanotubes (SWCNTs) as a foliar application to enhance maize photosynthesis under no-shading and shading stress. The results revealed that under shading stress, the higher concentration of CDs and SWCNTs reduced the MDA (Malondialdehyde) content and increased the expression level of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) genes. Moreover, under shading stress, CDs and SWCNTs increased the average thickness of leaf lamina, vascular bundle, mesophyll, and epidermis. CDs and SWCNTs reduced the damaging effects of shading stress on the chloroplast (Ch) formation. CDs and SWCNTs upregulated Rubisco and related genes under shading stress. The chlorophyll fluorescence parameters, including the efficiency of quantum yield of photosystem II (Fv/Fm), electron transport rate (ETR), non-photochemical quenching coefficient (NPQ), and photochemical quenching coefficient (qP) were improved with the foliar application of CDs and SWCNTs under shading stress. Higher stomatal conductance, intercellular CO2 concentration, transpiration, and net photosynthesis were observed in maize plants treated with CDs and SWCNTs under shading stress. The results of our study suggest that using higher concentrations of CDs and SWCNTs can enhance plant growth and photosynthesis under shading stress conditions. However, to avoid nanotoxicity, great care is recommended when selecting different concentrations of nanomaterials based on the growing conditions.

physiology↗

bioRxiv2024

Reversible disulfide bond crosslinks as tunable levers of phase separation in designer biomolecular condensates.

Biomolecular condensates (BCs) are membraneless hubs enriched in proteins and nucleic acids that have become important players in many cellular functions. Uncovering the sequence determinants of proteins for phase separation is important in understanding the biophysical and biochemical properties of BCs. Despite significant discoveries in the last decade, the role of cysteine residues in BC formation and dissolution has remained unknown. Here, to determine the involvement of disulfide crosslinks and their redox sensitivity in BCs, we designed a stickers and spacers model of phase-separating peptides interspersed with cysteines. Through biophysical investigations, we learned that cysteines promote liquid-liquid phase separation in oxidizing conditions and perpetuate liquid condensates through disulfide crosslinks, which can be reversibly tuned with redox chemistry. By varying the composition of cysteines, subtle but distinct changes in the viscoelastic behavior of the condensates were observed. Empirically, we conclude that cysteines are neither stickers nor spacers but function as covalent nodes to lower the effective concentrations for sticker interactions and inhibit system-spanning percolation networks. Together, we unmask the role of cysteines in protein phase behavior and the potential to develop tunable, redox-sensitive viscoelastic materials.

biophysics↗