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1.
Cell ; 187(2): 360-374.e19, 2024 01 18.
Article in English | MEDLINE | ID: mdl-38176410

ABSTRACT

The very-low-density lipoprotein receptor (VLDLR) comprises eight LDLR type A (LA) domains and supports entry of distantly related alphaviruses, including Eastern equine encephalitis virus (EEEV) and Semliki Forest virus (SFV). Here, by resolving multiple cryo-electron microscopy structures of EEEV-VLDLR complexes and performing mutagenesis and functional studies, we show that EEEV uses multiple sites (E1/E2 cleft and E2 A domain) to engage more than one LA domain simultaneously. However, no single LA domain is necessary or sufficient to support efficient EEEV infection. Whereas all EEEV strains show conservation of two VLDLR-binding sites, the EEEV PE-6 strain and a few other EEE complex members feature a single amino acid substitution that enables binding of LA domains to an additional site on the E2 B domain. These structural and functional analyses informed the design of a minimal VLDLR decoy receptor that neutralizes EEEV infection and protects mice from lethal challenge.


Subject(s)
Cryoelectron Microscopy , Encephalitis Virus, Eastern Equine , Encephalomyelitis, Equine , Receptors, LDL , Animals , Mice , Alphavirus/physiology , Encephalitis Virus, Eastern Equine/physiology , Encephalitis Virus, Eastern Equine/ultrastructure , Encephalomyelitis, Equine/metabolism , Horses , Protein Binding , Receptors, LDL/ultrastructure
2.
Nat Commun ; 15(1): 246, 2024 Jan 04.
Article in English | MEDLINE | ID: mdl-38172096

ABSTRACT

Members of the low-density lipoprotein receptor (LDLR) family, including LDLRAD3, VLDLR, and ApoER2, were recently described as entry factors for different alphaviruses. However, based on studies with gene edited cells and knockout mice, blockade or abrogation of these receptors does not fully inhibit alphavirus infection, indicating the existence of additional uncharacterized entry factors. Here, we perform a CRISPR-Cas9 genome-wide loss-of-function screen in mouse neuronal cells with a chimeric alphavirus expressing the Eastern equine encephalitis virus (EEEV) structural proteins and identify LDLR as a candidate receptor. Expression of LDLR on the surface of neuronal or non-neuronal cells facilitates binding and infection of EEEV, Western equine encephalitis virus, and Semliki Forest virus. Domain mapping and binding studies reveal a low-affinity interaction with LA domain 3 (LA3) that can be enhanced by concatenation of LA3 repeats. Soluble decoy proteins with multiple LA3 repeats inhibit EEEV infection in cell culture and in mice. Our results establish LDLR as a low-affinity receptor for multiple alphaviruses and highlight a possible path for developing inhibitors that could mitigate infection and disease.


Subject(s)
Alphavirus Infections , Alphavirus , Encephalitis Virus, Eastern Equine , Horses , Animals , Mice , Alphavirus/genetics , Encephalitis Virus, Eastern Equine/genetics , Semliki forest virus/genetics , Lipoproteins, LDL
3.
Thorac Cancer ; 15(3): 215-226, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38115677

ABSTRACT

BACKGROUND: Pyroptosis plays a pivotal role in the tumor immune microenvironment (TME) dynamics, particularly in non-small cell lung cancer (NSCLC). The aim of our study was to explore its effects on tumor progression, TME patterns, and the efficacy of therapeutic interventions in NSCLC. METHODS: Our investigation encompassed a thorough analysis of pyroptosis-related genes (PRGs), integrating immunohistochemistry (IHC) data, TME characteristics, stemness indices, and anticancer drug sensitivities. We aimed to analyze mRNA expression profiles across various cancers, constructing benchmark datasets to assess the clinical significance of PRGs in NSCLC. This included evaluating their association with clinical responses and efficacy. Notably, both our and HPA IHC data demonstrated significantly elevated GSDMD-N protein levels in lung squamous cell carcinoma (LUSC) tissues. RESULTS: The expression of PRGs differed significantly between tumor and normal tissues across various cancers, as validated by IHC data, and was correlated with prognosis (p < 0.05). Moreover, our investigation revealed significant differences (p < 0.05) in the expression of the PRGs among distinct TME subtypes categorized as C1 (wound healing), C3 (inflammatory), C2 (IFN-gamma dominant), C5 (immunological quiet), C4 (lymphocyte deficient), and C6 (TGF-beta dominant). Additionally, our research on anticancer drug sensitivity uncovered compelling connections between specific anticancer medications and the expression of PRGs, including GSDMD, ELANE, IL18, and CHMP4A (p < 0.05). CONCLUSION: Our study provided valuable insights into the critical role of PRGs in TME modulation, tumor stemness, and anticancer drug sensitivity across diverse cancers. Our findings illuminate the intricate relationship between pyroptosis and the TME, offering new perspectives for enhancing NSCLC treatment and prognosis.


Subject(s)
Antineoplastic Agents , Carcinoma, Non-Small-Cell Lung , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Prognosis , Pyroptosis/genetics , Lung Neoplasms/drug therapy , Lung Neoplasms/genetics , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Tumor Microenvironment
4.
Genomics ; 116(1): 110773, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38158141

ABSTRACT

Preadipocyte differentiation represents a critical stage in adipogenesis, with mitochondria playing an undeniable pivotal role. Given the intricate interplay between transcription and metabolic signaling during adipogenesis, the regulation of sirtuin 5 (SIRT5) on mitochondrial function and lipid metabolism was revealed via multiple omics analysis. The findings suggest that SIRT5 plays a crucial role in promoting mitochondrial biosynthesis and maintaining mitochondrial function during preadipocyte differentiation. Moreover, SIRT5 modulates the metabolic levels of numerous bioactive substances by extensively regulating genes expression associated with differentiation, energy metabolism, lipid synthesis, and mitochondrial function. Finally, SIRT5 was found to suppress triacylglycerols (TAG) accumulation while enhancing the proportion and diversity of unsaturated fatty acids, and providing conditions for the expansion and stability of membrane structure during mitochondrial biosynthesis through numerous gene regulations. Our findings provide a foundation for the identification of crucial functional genes, signaling pathways, and metabolic substances associated with adipose tissue differentiation and metabolism.


Subject(s)
Lipid Metabolism , Sirtuins , Cattle , Animals , Sirtuins/genetics , Sirtuins/metabolism , Adipogenesis , Mitochondria/genetics , Adipose Tissue/metabolism
5.
bioRxiv ; 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-38014196

ABSTRACT

The very low-density lipoprotein receptor (VLDLR) is comprised of eight LDLR type A (LA) domains and supports entry of distantly related Eastern equine encephalitis (EEEV) and Semliki Forest (SFV) alphaviruses. Here, by resolving multiple cryo-electron microscopy structures of EEEV-VLDLR complexes and performing mutagenesis and functional studies, we show that EEEV uses multiple sites (E1/E2 cleft and E2 A domain) to engage different LA domains simultaneously. However, no single LA domain is necessary or sufficient to support efficient EEEV infection, highlighting complexity in domain usage. Whereas all EEEV strains show conservation of two VLDLR binding sites, the EEEV PE-6 strain and other EEE complex members feature a single amino acid substitution that mediates binding of LA domains to an additional site on the E2 B domain. These structural and functional analyses informed the design of a minimal VLDLR decoy receptor that neutralizes EEEV infection and protects mice from lethal challenge.

6.
Cell Metab ; 35(12): 2216-2230.e8, 2023 12 05.
Article in English | MEDLINE | ID: mdl-37979583

ABSTRACT

Mammalian target of rapamycin complex 1 (mTORC1) monitors cellular amino acid changes for function, but the molecular mediators of this process remain to be fully defined. Here, we report that depletion of cellular amino acids, either alone or in combination, leads to the ubiquitination of mTOR, which inhibits mTORC1 kinase activity by preventing substrate recruitment. Mechanistically, amino acid depletion causes accumulation of uncharged tRNAs, thereby stimulating GCN2 to phosphorylate FBXO22, which in turn accrues in the cytoplasm and ubiquitinates mTOR at Lys2066 in a K27-linked manner. Accordingly, mutation of mTOR Lys2066 abolished mTOR ubiquitination in response to amino acid depletion, rendering mTOR insensitive to amino acid starvation both in vitro and in vivo. Collectively, these data reveal a novel mechanism of amino acid sensing by mTORC1 via a previously unknown GCN2-FBXO22-mTOR pathway that is uniquely controlled by uncharged tRNAs.


Subject(s)
Protein Serine-Threonine Kinases , TOR Serine-Threonine Kinases , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Amino Acids/metabolism , RNA, Transfer/genetics , RNA, Transfer/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism
7.
Cell ; 186(22): 4818-4833.e25, 2023 10 26.
Article in English | MEDLINE | ID: mdl-37804831

ABSTRACT

MXRA8 is a receptor for chikungunya (CHIKV) and other arthritogenic alphaviruses with mammalian hosts. However, mammalian MXRA8 does not bind to alphaviruses that infect humans and have avian reservoirs. Here, we show that avian, but not mammalian, MXRA8 can act as a receptor for Sindbis, western equine encephalitis (WEEV), and related alphaviruses with avian reservoirs. Structural analysis of duck MXRA8 complexed with WEEV reveals an inverted binding mode compared with mammalian MXRA8 bound to CHIKV. Whereas both domains of mammalian MXRA8 bind CHIKV E1 and E2, only domain 1 of avian MXRA8 engages WEEV E1, and no appreciable contacts are made with WEEV E2. Using these results, we generated a chimeric avian-mammalian MXRA8 decoy-receptor that neutralizes infection of multiple alphaviruses from distinct antigenic groups in vitro and in vivo. Thus, different alphaviruses can bind MXRA8 encoded by different vertebrate classes with distinct engagement modes, which enables development of broad-spectrum inhibitors.


Subject(s)
Alphavirus , Animals , Humans , Chikungunya Fever , Chikungunya virus/chemistry , Mammals , Receptors, Virus/metabolism
8.
Int J Biol Macromol ; 244: 125291, 2023 Jul 31.
Article in English | MEDLINE | ID: mdl-37315670

ABSTRACT

Liver cancer can be primary (starting in the liver) or secondary (cancer that has spread from elsewhere to the liver, known as liver metastasis). Liver metastasis is more common than primary liver cancer. Despite great advances in molecular biology methods and treatments, liver cancer is still associated with a poor survival rate and a high death rate, and there is no cure. Many questions remain regarding the mechanisms of liver cancer occurrence and development as well as tumor reoccurrence after treatment. In this study, we assessed the protein structural features of 20 oncogenes and 20 anti-oncogenes via protein structure and dynamic analysis methods and 3D structural and systematic analyses of the structure-function relationships of proteins. Our aim was to provide new insights that may inform research on the development and treatment of liver cancer.


Subject(s)
Liver Neoplasms , Humans , Liver Neoplasms/pathology , Proteins , Abdomen/pathology
9.
Clin Respir J ; 17(5): 343-356, 2023 May.
Article in English | MEDLINE | ID: mdl-37094822

ABSTRACT

Acquired digestive-respiratory tract fistulas occur with abnormal communication between the respiratory tract and digestive tract caused by a variety of benign or malignant diseases, leading to the alimentary canal contents in the respiratory tract. Although various departments have been actively exploring advanced fistula closure techniques, including surgical methods and multimodal therapy, some of which have gotten good clinical effects, there are few large-scale evidence-based medical data to guide clinical diagnosis and treatment. The guidelines update the etiology, classification, pathogenesis, diagnosis, and management of acquired digestive-respiratory tract fistulas. It has been proved that the implantation of the respiratory and digestive stent is the most important and best treatment for acquired digestive-respiratory tract fistulas. The guidelines conduct an in-depth review of the current evidence and introduce in detail the selection of stents, implantation methods, postoperative management and efficacy evaluation.


Subject(s)
Digestive System Fistula , East Asian People , Respiratory Tract Fistula , Humans , Consensus , Respiratory System , Respiratory Tract Fistula/diagnosis , Respiratory Tract Fistula/etiology , Respiratory Tract Fistula/therapy , Stents/adverse effects , Treatment Outcome , Digestive System Fistula/diagnosis , Digestive System Fistula/etiology , Digestive System Fistula/therapy
10.
Cell Death Dis ; 13(6): 532, 2022 06 06.
Article in English | MEDLINE | ID: mdl-35668069

ABSTRACT

PTENα and PTENß (PTENα/ß), two long translational variants of phosphatase and tensin homolog on chromosome 10 (PTEN), exert distinct roles from canonical PTEN, including promoting carcinogenesis and accelerating immune-resistant cancer progression. However, their roles in carcinogenesis remain greatly unknown. Herein, we report that, after secreting into the extracellular space, PTENα/ß proteins are efficiently cleaved into a short N-terminal and a long C-terminal fragment by the proprotein convertase Furin at a polyarginine stretch in their N-terminal extensions. Although secreted PTENα/ß and their cleaved fragment cannot enter cells, treatment of the purified C-terminal fragment but not cleavage-resistant mutants of PTENα exerts a tumor-suppressive role in vivo. As a result, overexpression of cleavage-resistant PTENα mutants manifest a tumor-promoting role more profound than that of wild-type PTENα. In line with these, the C-terminal fragment is significantly downregulated in liver cancer tissues compared to paired normal tissues, which is consistent with the downregulated expression of Furin. Collectively, we show that extracellular PTENα/ß present opposite effects on carcinogenesis from intracellular PTENα/ß, and propose that the tumor-suppressive C-terminal fragment of PTENα/ß might be used as exogenous agent to treat cancer.


Subject(s)
Furin , Liver Neoplasms , Carcinogenesis , Furin/genetics , Humans , Proprotein Convertases
11.
Nature ; 598(7882): 672-676, 2021 10.
Article in English | MEDLINE | ID: mdl-34646020

ABSTRACT

LDLRAD3 is a recently defined attachment and entry receptor for Venezuelan equine encephalitis virus (VEEV)1, a New World alphavirus that causes severe neurological disease in humans. Here we present near-atomic-resolution cryo-electron microscopy reconstructions of VEEV virus-like particles alone and in a complex with the ectodomains of LDLRAD3. Domain 1 of LDLRAD3 is a low-density lipoprotein receptor type-A module that binds to VEEV by wedging into a cleft created by two adjacent E2-E1 heterodimers in one trimeric spike, and engages domains A and B of E2 and the fusion loop in E1. Atomic modelling of this interface is supported by mutagenesis and anti-VEEV antibody binding competition assays. Notably, VEEV engages LDLRAD3 in a manner that is similar to the way that arthritogenic alphaviruses bind to the structurally unrelated MXRA8 receptor, but with a much smaller interface. These studies further elucidate the structural basis of alphavirus-receptor interactions, which could inform the development of therapies to mitigate infection and disease against multiple members of this family.


Subject(s)
Encephalitis Virus, Venezuelan Equine/chemistry , Receptors, LDL/chemistry , Receptors, Virus/chemistry , Amino Acid Sequence , Animals , Cell Line , Cryoelectron Microscopy , Humans , Mice , Models, Molecular , Protein Structure, Secondary , Sequence Alignment , Virus Internalization
12.
Thorac Cancer ; 12(18): 2439-2448, 2021 09.
Article in English | MEDLINE | ID: mdl-34337871

ABSTRACT

PURPOSE: The objective of our study was to investigate the epidemiologic characteristics and prognostic factors in patients with pulmonary acinar cell carcinoma (PACC). METHODS: PACC patients diagnosed between 1975 and 2016 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The trend in PACC incidence was assessed using joinpoint regression software. Overall survival (OS) and disease-specific survival (DSS) were evaluated using the Kaplan-Meier method and log-rank test. Univariate and multivariate Cox regression analysis was performed to identify the independent prognostic factors for OS and DSS. Nomograms to predict survival possibilities were constructed based on the identified independent prognostic factors. RESULTS: A total of 2918 patients were identified with PACC. The mean age was 65.2 ± 8.95 years with a female to male of 1.6:1. The incidence of PACC steadily increased by an annual percentage change (APC) of 3.2% (95% CI 2.1-4.4, p < 0.05). Multivariate Cox regression analysis revealed that age, gender, race, stage, grade, tumor size, number of positive lymph nodes, surgery, and chemotherapy were independent prognostic factors for survival. Nomograms specifically for PACC were constructed to predict 1- and 5-year OS and DSS possibility, respectively. The concordance index (C-index) and calibration plots showed the established nomograms had robust and accurate performance. CONCLUSION: PACC was rare but the incidence has been steadily increasing over the past four decades. Survival has improved in recent years. Surgery or chemotherapy could provide better OS and DSS. The established nomograms specifically for PACC were robust and accurate in predicting 1- and 5-year OS and DSS.


Subject(s)
Carcinoma, Acinar Cell/epidemiology , Lung Neoplasms/epidemiology , Adult , Aged , Carcinoma, Acinar Cell/mortality , Disease-Free Survival , Female , Humans , Lung Neoplasms/mortality , Male , Middle Aged , Prognosis , SEER Program , Survival Rate , United States/epidemiology
13.
Soft Matter ; 17(8): 2191-2204, 2021 Mar 04.
Article in English | MEDLINE | ID: mdl-33459746

ABSTRACT

An intrinsic self-healing polyurethane (PU) elastomer with excellent self-healing efficiency was prepared. The self-healing properties of this elastomer as well as the temperature dependence of self-healing can be tailored by regulating the molar ratio of hard to soft segments. The self-healing efficiency of 92.5% is the highest when the molar ratio of 4,4-methylenedicyclohexyl diisocyanate (HMDI) to polypropylene carbonate polyol (PPC) is 1.3 and the temperature is 25 °C. In situ temperature swing infrared spectra and low-field nuclear magnetic resonance reveal that the soft segment, PPC, endows PU with a dense dynamic hydrogen bond network, and the dissociation and reconstruction of the hydrogen bond network enable the PU to heal. To date, the exchange of hydrogen bonds has not been observed intuitively through experimental means. Therefore, the number, type, strength, lifetime, and the exchange of hydrogen bonds in the self-healing process at different temperatures were investigated by molecular dynamics (MD) simulation. The simulated results show that the type of hydrogen bond exchange between functional groups will be affected by temperature. The hydrogen bonds between urethane and urea groups play a leading role in the self-healing properties due to the high strength and a large number of hydrogen bonds at both 25 and 50 °C. The stronger strength, longer lifetime, and greater number of effective hydrogen bonds at 25 °C make the self-healing efficiency of PU higher than at 50 °C.

14.
Cell Metab ; 33(2): 270-282.e8, 2021 02 02.
Article in English | MEDLINE | ID: mdl-33278339

ABSTRACT

Recent studies suggest that mitochondria can be transferred between cells to support the survival of metabolically compromised cells. However, whether intercellular mitochondria transfer occurs in white adipose tissue (WAT) or regulates metabolic homeostasis in vivo remains unknown. We found that macrophages acquire mitochondria from neighboring adipocytes in vivo and that this process defines a transcriptionally distinct macrophage subpopulation. A genome-wide CRISPR-Cas9 knockout screen revealed that mitochondria uptake depends on heparan sulfates (HS). High-fat diet (HFD)-induced obese mice exhibit lower HS levels on WAT macrophages and decreased intercellular mitochondria transfer from adipocytes to macrophages. Deletion of the HS biosynthetic gene Ext1 in myeloid cells decreases mitochondria uptake by WAT macrophages, increases WAT mass, lowers energy expenditure, and exacerbates HFD-induced obesity in vivo. Collectively, this study suggests that adipocytes and macrophages employ intercellular mitochondria transfer as a mechanism of immunometabolic crosstalk that regulates metabolic homeostasis and is impaired in obesity.


Subject(s)
Adipose Tissue, White/metabolism , Homeostasis , Macrophages/metabolism , Mitochondria/metabolism , Obesity/metabolism , Animals , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic
15.
Ther Adv Respir Dis ; 14: 1753466620976012, 2020.
Article in English | MEDLINE | ID: mdl-33272105

ABSTRACT

BACKGROUND: Hemorrhage is a life-threatening complication during bronchoscopic intervention in patients with central airway obstruction (CAO) due to metastatic renal cell carcinoma (RCC). Whether pre-bronchoscopic bronchial arterial embolization (BAE) can reduce the risk of severe bleeding in CAO patients due to metastatic RCC remains unclear. METHODS: A total of 31 CAO patients due to metastatic RCC were included retrospectively and divided into a BAE group (receiving pre-bronchoscopic BAE) and non-BAE group in this study. Based on computed tomography (CT) and bronchoscopic findings, tumor debulking was used to reconstruct the airway during interventional bronchoscopy. The primary outcome was the incidence of severe bleeding during bronchoscopic procedures. Bleeding-related complications, Karnofsky performance score (KPS) and dyspnea score were also analyzed over a 1-month observation period. RESULTS: There were no significant differences between the two groups in baseline characteristics, including patients' features, tumor morphology under CT scannings, tumor site, and obstruction degree under bronchoscopic examination. Procedure-related bleeding occurred in all 31 patients. Pre-bronchoscopic BAE significantly reduced the incidence of moderate and major bleeding when compared with that in the non-BAE group. The incidence of poor visualization and hypoxia was also reduced significantly in the BAE group. There was no significant difference in KPS and dyspnea score between the BAE and non-BAE groups at 1 month follow up. CONCLUSION: Pre-bronchoscopic BAE might be a feasible option to reduce the risk of severe bleeding for CAO patients due to metastatic RCC during bronchoscopic intervention. Interventional bronchoscopy was a safe and effective procedure for CAO due to metastatic RCC.The reviews of this paper are available via the supplemental material section.


Subject(s)
Airway Obstruction/surgery , Bronchial Neoplasms/surgery , Bronchoscopy , Carcinoma, Renal Cell/surgery , Embolization, Therapeutic , Hemorrhage/prevention & control , Adult , Aged , Aged, 80 and over , Airway Obstruction/etiology , Bronchial Arteries , Bronchial Neoplasms/secondary , Carcinoma, Renal Cell/pathology , Carcinoma, Renal Cell/secondary , Female , Humans , Intraoperative Complications/prevention & control , Kidney Neoplasms/pathology , Male , Middle Aged , Retrospective Studies
16.
Nature ; 588(7837): 308-314, 2020 12.
Article in English | MEDLINE | ID: mdl-33208938

ABSTRACT

Venezuelan equine encephalitis virus (VEEV) is a neurotropic alphavirus transmitted by mosquitoes that causes encephalitis and death in humans1. VEEV is a biodefence concern because of its potential for aerosol spread and the current lack of sufficient countermeasures. The host factors that are required for VEEV entry and infection remain poorly characterized. Here, using a genome-wide CRISPR-Cas9-based screen, we identify low-density lipoprotein receptor class A domain-containing 3 (LDLRAD3)-a highly conserved yet poorly characterized member of the scavenger receptor superfamily-as a receptor for VEEV. Gene editing of mouse Ldlrad3 or human LDLRAD3 results in markedly reduced viral infection of neuronal cells, which is restored upon complementation with LDLRAD3. LDLRAD3 binds directly to VEEV particles and enhances virus attachment and internalization into host cells. Genetic studies indicate that domain 1 of LDLRAD3 (LDLRAD3(D1)) is necessary and sufficient to support infection by VEEV, and both anti-LDLRAD3 antibodies and an LDLRAD3(D1)-Fc fusion protein block VEEV infection in cell culture. The pathogenesis of VEEV infection is abrogated in mice with deletions in Ldlrad3, and administration of LDLRAD3(D1)-Fc abolishes disease caused by several subtypes of VEEV, including highly virulent strains. The development of a decoy-receptor fusion protein suggests a strategy for the prevention of severe VEEV infection and associated disease in humans.


Subject(s)
Encephalitis Virus, Venezuelan Equine/metabolism , Receptors, LDL/metabolism , Receptors, Virus/metabolism , Animals , CRISPR-Cas Systems/genetics , Cell Line , Encephalitis Virus, Venezuelan Equine/pathogenicity , Encephalomyelitis, Venezuelan Equine/metabolism , Encephalomyelitis, Venezuelan Equine/prevention & control , Encephalomyelitis, Venezuelan Equine/virology , Female , Genetic Complementation Test , Humans , Male , Mice , Mice, Inbred C57BL , Protein Binding , Receptors, LDL/deficiency , Receptors, LDL/genetics , Receptors, Virus/genetics , Virus Attachment , Virus Internalization
17.
mBio ; 11(2)2020 03 10.
Article in English | MEDLINE | ID: mdl-32156810

ABSTRACT

Although the pathogen recognition receptor pathways that activate cell-intrinsic antiviral responses are well delineated, less is known about how the host regulates this response to prevent sustained signaling and possible immune-mediated damage. Using a genome-wide CRISPR-Cas9 screening approach to identify host factors that modulate interferon-stimulated gene (ISG) expression, we identified the DNA binding protein Barrier-to-autointegration factor 1 (Banf1), a previously described inhibitor of retrovirus integration, as a modulator of basal cell-intrinsic immunity. Ablation of Banf1 by gene editing resulted in chromatin activation near host defense genes with associated increased expression of ISGs, including Oas2, Rsad2 (viperin), Ifit1, and ISG15 The phenotype in Banf1-deficient cells occurred through a cGAS-, STING-, and IRF3-dependent signaling axis, was associated with reduced infection of RNA and DNA viruses, and was reversed in Banf1 complemented cells. Confocal microscopy and biochemical studies revealed that a loss of Banf1 expression resulted in higher level of cytosolic double-stranded DNA at baseline. Our study identifies an undescribed role for Banf1 in regulating the levels of cytoplasmic DNA and cGAS-dependent ISG homeostasis and suggests possible therapeutic directions for promoting or inhibiting cell-intrinsic innate immune responses.IMPORTANCE Although the interferon (IFN) signaling pathway is a key host mechanism to restrict infection of a diverse range of viral pathogens, its unrestrained activity either at baseline or in the context of an immune response can result in host cell damage and injury. Here, we used a genome-wide CRISPR-Cas9 screen and identified the DNA binding protein Barrier-to-autointegration factor 1 (Banf1) as a modulator of basal cell-intrinsic immunity. A loss of Banf1 expression resulted in higher level of cytosolic double-stranded DNA at baseline, which triggered IFN-stimulated gene expression via a cGAS-STING-IRF3 axis that did not require type I IFN or STAT1 signaling. Our experiments define a regulatory network in which Banf1 limits basal inflammation by preventing self DNA accumulation in the cytosol.


Subject(s)
DNA-Binding Proteins/immunology , Host-Pathogen Interactions , Membrane Proteins/immunology , Nuclear Proteins/immunology , Nucleotidyltransferases/immunology , Animals , CRISPR-Cas Systems , Cell Line , DNA-Binding Proteins/genetics , Gene Editing , Gene Expression Regulation , Homeostasis/immunology , Humans , Immunity, Innate , Interferons/immunology , Mice , Microglia/immunology , Nuclear Proteins/genetics , Signal Transduction
18.
J Med Entomol ; 57(1): 65-77, 2020 01 09.
Article in English | MEDLINE | ID: mdl-31504655

ABSTRACT

Sarcophaga peregrina is an important flesh fly species for estimating the minimum postmortem interval (PMImin) in forensic entomology. The accurate determination of the developmental age is a crucial task for using necrophagous sarcophagids to estimate PMImin. During larval development, the age determination is straight forward by the morphological changes and variation of length, weight, and width; however, the age estimation of sarcophagid intrapuparial is more difficult due to anatomical and morphological changes not being visible. The analysis of differentially expressed genes (DEGs) during sarcophagid metamorphosis is a potential method for age estimation of intrapuparial. In the present study, real-time quantitative polymerase chain reaction (RT-qPCR) was used to analyze the differential gene expression level of S. peregrina intrapuparial in different constant temperatures (35°C, 25°C, and 15°C). In addition, the appropriate reference genes of S. peregrina were selected in the intrapuparial and at different temperatures to obtain reliable and valid gene expression profiles. The results indicated that two candidate genes (18S rRNA and 28S rRNA) were the most reliable reference genes, and four DEGs (Hsp90, A-alpha, AFP, AFBP) have the potential to be used to more accuracy estimate the age of S. peregrina intrapuparial.


Subject(s)
Forensic Entomology/methods , Gene Expression , Sarcophagidae/growth & development , Sarcophagidae/genetics , Age Factors , Animals , Pupa/genetics , Pupa/growth & development
19.
Mol Med Rep ; 21(1): 508-516, 2020 01.
Article in English | MEDLINE | ID: mdl-31746394

ABSTRACT

Depression is often triggered by prolonged exposure to psychosocial stressors and associated with coronary heart disease (CHD). Matrix metalloproteinases (MMPs) are involved in the pathogenesis of various emotional and cardiovascular disorders. The purpose of this study was to investigate whether Kai­Xin­San (KXS), which may terminate the signaling of MMPs, exerts antidepressant­like and cardioprotective effects in a myocardial infarction (MI) plus depression rat model. Rats were randomly assigned to five groups: A normal control (control group), a celisc­injection of isopropyl adrenaline group (ISO group), depression (depression group), an ISO + depression (depression + ISO group), and an ISO + depression group treated with intragastric administration of 1,785 mg/kg KXS (KXS group). Behavioral changes, echocardiography, biochemical index, matrix metalloproteinase (MMP) and apoptosis­related proteins were assessed. Compared with the depression + ISO group, KXS significantly improved stress­induced alterations of behavioral parameters and protected the heart by enlarging the left ventricular (LV) fractional shortening (FS) and LV ejection fraction (EF). Moreover, KXS significantly attenuated ISO + depression­induced MMP­2 and MMP­9 expression at the mRNA and protein level and decreased TIMP in the heart compared to the complex model group. Myocardial apoptosis was significantly attenuated by KXS by regulating the Bcl­2/Bax axis. These results indicated that MI comorbid with depression may damage the MMP balance in the central and peripheral system, and KXS may have a direct anti­depressive and cardio­protective effect by regulating the level of MMPs and associated myocardial apoptosis. It is promising to further explore the clinical potential of KXS for the therapy or prevention of MI plus depression comorbidity disease.


Subject(s)
Depression/drug therapy , Drugs, Chinese Herbal/pharmacology , Matrix Metalloproteinase 2/genetics , Matrix Metalloproteinase 9/genetics , Myocardial Infarction/drug therapy , Animals , Apoptosis/drug effects , Depression/chemically induced , Depression/genetics , Depression/pathology , Disease Models, Animal , Epinephrine/toxicity , Gene Expression Regulation/drug effects , Heart Ventricles/drug effects , Heart Ventricles/pathology , Humans , Matrix Metalloproteinases/genetics , Myocardial Infarction/chemically induced , Myocardial Infarction/genetics , Myocardial Infarction/pathology , Myocardium/metabolism , Rats , Signal Transduction/drug effects
20.
Eur J Pharm Sci ; 140: 105058, 2019 Dec 01.
Article in English | MEDLINE | ID: mdl-31472255

ABSTRACT

The biofilm formation of Pseudomonas aeruginosa (P. aeruginosa) is regulated by a phenomenon of quorum sensing (QS). With 5-hydroxyl-3,4-halogenated-5H-furan-2-ones as beginning, analogs bearing alkyl chains, vinyl bromide, or aromatic rings were designed and synthesized. The minimum inhibitory concentration (MIC) of the compounds against P. aeruginosa was assayed and the biofilm inhibition ratio was determined at different concentrations lower than the MIC. C-5 aromatic substituted furanones showed remarkable biofilm formation as well as inhibition of virulence factor production in P. aeruginosa. Fluorescence report analysis identified the QS regulatory mechanism of the most active compound 29. This study provides us a novel candidate for combating drug resistant bacteria strains by merely inhibiting biofilm formation. Without suppressing the regular life cycle of the bacteria, bacterial resistance mechanisms may not be activated.


Subject(s)
Furans/chemistry , Furans/pharmacology , Pseudomonas aeruginosa/drug effects , Quorum Sensing/drug effects , Animals , Biofilms/drug effects , Cell Survival/drug effects , Halogenation , Mice , Microbial Sensitivity Tests , RAW 264.7 Cells , Virulence Factors/metabolism
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