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1.
PLoS Pathog ; 18(1): e1010219, 2022 01.
Article in English | MEDLINE | ID: covidwho-2197167

ABSTRACT

Excessive inflammation is a major cause of morbidity and mortality in many viral infections including influenza. Therefore, there is a need for therapeutic interventions that dampen and redirect inflammatory responses and, ideally, exert antiviral effects. Itaconate is an immunomodulatory metabolite which also reprograms cell metabolism and inflammatory responses when applied exogenously. We evaluated effects of endogenous itaconate and exogenous application of itaconate and its variants dimethyl- and 4-octyl-itaconate (DI, 4OI) on host responses to influenza A virus (IAV). Infection induced expression of ACOD1, the enzyme catalyzing itaconate synthesis, in monocytes and macrophages, which correlated with viral replication and was abrogated by DI and 4OI treatment. In IAV-infected mice, pulmonary inflammation and weight loss were greater in Acod1-/- than in wild-type mice, and DI treatment reduced pulmonary inflammation and mortality. The compounds reversed infection-triggered interferon responses and modulated inflammation in human cells supporting non-productive and productive infection, in peripheral blood mononuclear cells, and in human lung tissue. All three itaconates reduced ROS levels and STAT1 phosphorylation, whereas AKT phosphorylation was reduced by 4OI and DI but increased by itaconate. Single-cell RNA sequencing identified monocytes as the main target of infection and the exclusive source of ACOD1 mRNA in peripheral blood. DI treatment silenced IFN-responses predominantly in monocytes, but also in lymphocytes and natural killer cells. Ectopic synthesis of itaconate in A549 cells, which do not physiologically express ACOD1, reduced infection-driven inflammation, and DI reduced IAV- and IFNγ-induced CXCL10 expression in murine macrophages independent of the presence of endogenous ACOD1. The compounds differed greatly in their effects on cellular gene homeostasis and released cytokines/chemokines, but all three markedly reduced release of the pro-inflammatory chemokines CXCL10 (IP-10) and CCL2 (MCP-1). Viral replication did not increase under treatment despite the dramatically repressed IFN responses. In fact, 4OI strongly inhibited viral transcription in peripheral blood mononuclear cells, and the compounds reduced viral titers (4OI>Ita>DI) in A549 cells whereas viral transcription was unaffected. Taken together, these results reveal itaconates as immunomodulatory and antiviral interventions for influenza virus infection.


Subject(s)
Influenza A virus/immunology , Macrophages/immunology , Orthomyxoviridae Infections/drug therapy , Succinates/pharmacology , A549 Cells , Animals , Carboxy-Lyases/deficiency , Carboxy-Lyases/immunology , Cytokines/genetics , Cytokines/immunology , Humans , Macrophages/virology , Mice , Mice, Knockout , Orthomyxoviridae Infections/genetics , Orthomyxoviridae Infections/immunology , THP-1 Cells
2.
J Am Soc Nephrol ; 33(2): 326-341, 2022 02.
Article in English | MEDLINE | ID: covidwho-2141035

ABSTRACT

BACKGROUND: Hereditary renal hypouricemia type 1 (RHUC1) is caused by URAT1/SLC22A12 dysfunction, resulting in urolithiasis and exercise-induced AKI (EIAKI). However, because there is no useful experimental RHUC1 animal model, the precise pathophysiologic mechanisms underlying EIAKI have yet to be elucidated. We established a high HPRT activity Urat1-Uox double knockout (DKO) mouse as a novel RHUC1 animal model for investigating the cause of EIAKI and the potential therapeutic effect of xanthine oxidoreductase inhibitors (XOIs). METHODS: The novel Urat1-Uox DKO mice were used in a forced swimming test as loading exercise to explore the onset mechanism of EIAKI and evaluate related purine metabolism and renal injury parameters. RESULTS: Urat1-Uox DKO mice had uricosuric effects and elevated levels of plasma creatinine and BUN as renal injury markers, and decreased creatinine clearance observed in a forced swimming test. In addition, Urat1-Uox DKO mice had increased NLRP3 inflammasome activity and downregulated levels of Na+-K+-ATPase protein in the kidney, as Western blot analysis showed. Finally, we demonstrated that topiroxostat and allopurinol, XOIs, improved renal injury and functional parameters of EIAKI. CONCLUSIONS: Urat1-Uox DKO mice are a useful experimental animal model for human RHUC1. The pathogenic mechanism of EIAKI was found to be due to increased levels of IL-1ß via NLRP3 inflammasome signaling and Na+-K+-ATPase dysfunction associated with excessive urinary urate excretion. In addition, XOIs appear to be a promising therapeutic agent for the treatment of EIAKI.


Subject(s)
Acute Kidney Injury/drug therapy , Hypoxanthine Phosphoribosyltransferase/metabolism , Organic Anion Transporters/deficiency , Urate Oxidase/deficiency , Xanthine Dehydrogenase/antagonists & inhibitors , Acute Kidney Injury/etiology , Acute Kidney Injury/metabolism , Allopurinol/pharmacology , Animals , Disease Models, Animal , Enzyme Inhibitors/pharmacology , Hypoxanthine Phosphoribosyltransferase/genetics , Kidney/drug effects , Kidney/metabolism , Kidney/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Nitriles/pharmacology , Organic Anion Transporters/genetics , Physical Exertion , Pyridines/pharmacology , Renal Tubular Transport, Inborn Errors/drug therapy , Renal Tubular Transport, Inborn Errors/etiology , Renal Tubular Transport, Inborn Errors/metabolism , Sodium-Potassium-Exchanging ATPase/metabolism , Urate Oxidase/genetics , Urinary Calculi/drug therapy , Urinary Calculi/etiology , Urinary Calculi/metabolism
3.
J Am Soc Nephrol ; 33(4): 786-808, 2022 04.
Article in English | MEDLINE | ID: covidwho-2141050

ABSTRACT

BACKGROUND: The cell-matrix adhesion between podocytes and the glomerular basement membrane is essential for the integrity of the kidney's filtration barrier. Despite increasing knowledge about the complexity of integrin adhesion complexes, an understanding of the regulation of these protein complexes in glomerular disease remains elusive. METHODS: We mapped the in vivo composition of the podocyte integrin adhesome. In addition, we analyzed conditional knockout mice targeting a gene (Parva) that encodes an actin-binding protein (α-parvin), and murine disease models. To evaluate podocytes in vivo, we used super-resolution microscopy, electron microscopy, multiplex immunofluorescence microscopy, and RNA sequencing. We performed functional analysis of CRISPR/Cas9-generated PARVA single knockout podocytes and PARVA and PARVB double knockout podocytes in three- and two-dimensional cultures using specific extracellular matrix ligands and micropatterns. RESULTS: We found that PARVA is essential to prevent podocyte foot process effacement, detachment from the glomerular basement membrane, and the development of FSGS. Through the use of in vitro and in vivo models, we identified an inherent PARVB-dependent compensatory module at podocyte integrin adhesion complexes, sustaining efficient mechanical linkage at the filtration barrier. Sequential genetic deletion of PARVA and PARVB induces a switch in structure and composition of integrin adhesion complexes. This redistribution of these complexes translates into a loss of the ventral actin cytoskeleton, decreased adhesion capacity, impaired mechanical resistance, and dysfunctional extracellular matrix assembly. CONCLUSIONS: The findings reveal adaptive mechanisms of podocyte integrin adhesion complexes, providing a conceptual framework for therapeutic strategies to prevent podocyte detachment in glomerular disease.


Subject(s)
Glomerular Filtration Barrier , Microfilament Proteins , Podocytes , Animals , Glomerular Filtration Barrier/metabolism , Integrins/metabolism , Mice , Mice, Knockout , Microfilament Proteins/metabolism , Podocytes/metabolism
4.
Nat Commun ; 13(1): 6100, 2022 Oct 15.
Article in English | MEDLINE | ID: covidwho-2077054

ABSTRACT

In cultured cells, SARS-CoV-2 infects cells via multiple pathways using different host proteases. Recent studies have shown that the furin and TMPRSS2 (furin/TMPRSS2)-dependent pathway plays a minor role in infection of the Omicron variant. Here, we confirm that Omicron uses the furin/TMPRSS2-dependent pathway inefficiently and enters cells mainly using the cathepsin-dependent endocytosis pathway in TMPRSS2-expressing VeroE6/TMPRSS2 and Calu-3 cells. This is the case despite efficient cleavage of the spike protein of Omicron. However, in the airways of TMPRSS2-knockout mice, Omicron infection is significantly reduced. We furthermore show that propagation of the mouse-adapted SARS-CoV-2 QHmusX strain and human clinical isolates of Beta and Gamma is reduced in TMPRSS2-knockout mice. Therefore, the Omicron variant isn't an exception in using TMPRSS2 in vivo, and analysis with TMPRSS2-knockout mice is important when evaluating SARS-CoV-2 variants. In conclusion, this study shows that TMPRSS2 is critically important for SARS-CoV-2 infection of murine airways, including the Omicron variant.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Humans , Mice , Cathepsins , Furin/genetics , Furin/metabolism , Mice, Knockout , Peptide Hydrolases , Serine Endopeptidases/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization
5.
Science ; 378(6615): eabn5648, 2022 10 07.
Article in English | MEDLINE | ID: covidwho-2019693

ABSTRACT

Lysosomes are key degradative compartments of the cell. Transport to lysosomes relies on GlcNAc-1-phosphotransferase-mediated tagging of soluble enzymes with mannose 6-phosphate (M6P). GlcNAc-1-phosphotransferase deficiency leads to the severe lysosomal storage disorder mucolipidosis II (MLII). Several viruses require lysosomal cathepsins to cleave structural proteins and thus depend on functional GlcNAc-1-phosphotransferase. We used genome-scale CRISPR screens to identify lysosomal enzyme trafficking factor (LYSET, also named TMEM251) as essential for infection by cathepsin-dependent viruses including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). LYSET deficiency resulted in global loss of M6P tagging and mislocalization of GlcNAc-1-phosphotransferase from the Golgi complex to lysosomes. Lyset knockout mice exhibited MLII-like phenotypes, and human pathogenic LYSET alleles failed to restore lysosomal sorting defects. Thus, LYSET is required for correct functioning of the M6P trafficking machinery and mutations in LYSET can explain the phenotype of the associated disorder.


Subject(s)
COVID-19 , Lysosomes , Mucolipidoses , Proteins , Animals , COVID-19/genetics , Cathepsins/metabolism , Humans , Lysosomes/metabolism , Mannose/metabolism , Mice , Mice, Knockout , Mucolipidoses/genetics , Mucolipidoses/metabolism , Proteins/genetics , Transferases (Other Substituted Phosphate Groups)
6.
J Virol ; 96(17): e0077422, 2022 09 14.
Article in English | MEDLINE | ID: covidwho-1992940

ABSTRACT

XIAP-associated factor 1 (XAF1) is an interferon (IFN)-stimulated gene (ISG) that enhances IFN-induced apoptosis. However, it is unexplored whether XAF1 is essential for the host fighting against invaded viruses. Here, we find that XAF1 is significantly upregulated in the host cells infected with emerging RNA viruses, including influenza, Zika virus (ZIKV), and SARS-CoV-2. IFN regulatory factor 1 (IRF1), a key transcription factor in immune cells, determines the induction of XAF1 during antiviral immunity. Ectopic expression of XAF1 protects host cells against various RNA viruses independent of apoptosis. Knockout of XAF1 attenuates host antiviral innate immunity in vitro and in vivo, which leads to more severe lung injuries and higher mortality in the influenza infection mouse model. XAF1 stabilizes IRF1 protein by antagonizing the CHIP-mediated degradation of IRF1, thus inducing more antiviral IRF1 target genes, including DDX58, DDX60, MX1, and OAS2. Our study has described a protective role of XAF1 in the host antiviral innate immunity against RNA viruses. We have also elucidated the molecular mechanism that IRF1 and XAF1 form a positive feedback loop to induce rapid and robust antiviral immunity. IMPORTANCE Rapid and robust induction of antiviral genes is essential for the host to clear the invaded viruses. In addition to the IRF3/7-IFN-I-STAT1 signaling axis, the XAF1-IRF1 positive feedback loop synergistically or independently drives the transcription of antiviral genes. Moreover, XAF1 is a sensitive and reliable gene that positively correlates with the viral infection, suggesting that XAF1 is a potential diagnostic marker for viral infectious diseases. In addition to the antitumor role, our study has shown that XAF1 is essential for antiviral immunity. XAF1 is not only a proapoptotic ISG, but it also stabilizes the master transcription factor IRF1 to induce antiviral genes. IRF1 directly binds to the IRF-Es of its target gene promoters and drives their transcriptions, which suggests a unique role of the XAF1-IRF1 loop in antiviral innate immunity, particularly in the host defect of IFN-I signaling such as invertebrates.


Subject(s)
Adaptor Proteins, Signal Transducing , Apoptosis Regulatory Proteins , Interferon Regulatory Factor-1 , RNA Virus Infections , RNA Viruses , Adaptor Proteins, Signal Transducing/immunology , Animals , Apoptosis Regulatory Proteins/immunology , Humans , Immunity, Innate , Interferon Regulatory Factor-1/immunology , Mice , Mice, Knockout , RNA Virus Infections/immunology , Virus Replication
7.
Dis Model Mech ; 14(10)2021 10 01.
Article in English | MEDLINE | ID: covidwho-1962950

ABSTRACT

The 2021 Nobel Prize in Physiology or Medicine was awarded to Ardem Patapoutian and David Julius for their research on receptor channels responsible for the perception of touch and temperature. Somatosensation, an overarching sense that enables us to safely interface with the physical forces around and within us, is the fourth sensory modality to be recognized by the Nobel Committee. The story of the discovery of TRP and PIEZO channels, and subsequent investigations into their myriad roles in the perception of noxious and mild temperature, touch, pain, pressure and body position, is an archetype for how translational research into human and animal health is built on a foundation of excellence in basic science.


Subject(s)
Medicine , Nobel Prize , Physiology , Touch/physiology , Animals , Mechanoreceptors/metabolism , Mice, Knockout , Temperature
8.
Int J Mol Sci ; 21(9)2020 Apr 30.
Article in English | MEDLINE | ID: covidwho-1934078

ABSTRACT

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) initiates the cytokine/chemokine storm-mediated lung injury. The SARS-CoV unique domain (SUD) with three macrodomains (N, M, and C), showing the G-quadruplex binding activity, was examined the possible role in SARS pathogenesis in this study. The chemokine profile analysis indicated that SARS-CoV SUD significantly up-regulated the expression of CXCL10, CCL5 and interleukin (IL)-1ß in human lung epithelial cells and in the lung tissues of the mice intratracheally instilled with the recombinant plasmids. Among the SUD subdomains, SUD-MC substantially activated AP-1-mediated CXCL10 expression in vitro. In the wild type mice, SARS-CoV SUD-MC triggered the pulmonary infiltration of macrophages and monocytes, inducing CXCL10-mediated inflammatory responses and severe diffuse alveolar damage symptoms. Moreover, SUD-MC actuated NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome-dependent pulmonary inflammation, as confirmed by the NLRP3 inflammasome inhibitor and the NLRP3-/- mouse model. This study demonstrated that SARS-CoV SUD modulated NLRP3 inflammasome-dependent CXCL10-mediated pulmonary inflammation, providing the potential therapeutic targets for developing the antiviral agents.


Subject(s)
Chemokine CXCL10/metabolism , Inflammasomes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Viral Proteins/metabolism , Animals , Bronchoalveolar Lavage Fluid/chemistry , Bronchoalveolar Lavage Fluid/immunology , Cell Line , Chemokine CXCL10/genetics , Disease Models, Animal , Humans , Lung/metabolism , Lung/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , Monocytes/immunology , Monocytes/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/deficiency , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Pneumonia/pathology , Pneumonia/virology , Promoter Regions, Genetic , Severe Acute Respiratory Syndrome/pathology , Severe Acute Respiratory Syndrome/virology , Up-Regulation , Viral Proteins/chemistry , Viral Proteins/genetics
9.
PLoS One ; 17(6): e0270418, 2022.
Article in English | MEDLINE | ID: covidwho-1910682

ABSTRACT

Thymidine kinase 2 (TK2) deficiency in humans leads to a myopathic form of mitochondrial DNA (mtDNA) deficiency. Here we present a skeletal and cardiac muscle specific TK2 knockout mouse (mTk2 KO). The mice showed dilated hearts and markedly reduced adipose tissue during week 12 to 16. A severe decrease of mtDNA was found only in skeletal muscle and heart tissue in mTk2 KO mice. Expression analysis of key metabolic genes of 16 weeks knockout mice showed significant changes of genes involved in lipid metabolism, with different patterns in heart and skeletal muscle. Our study further suggests that lipoprotein lipase (LPL) from liver supports the metabolism when heart and skeletal muscle were impaired due to mitochondrial dysfunction. The angiotensin-converting enzyme 2 (ACE2), which is involved in glucose homeostasis, was also affected by mtDNA deficiency in our study. Interestingly, both the gene and protein expression of ACE2 were increased in cardiac tissue of mTk2 KO mice. Since ACE2 is a receptor for the SARS-CoV-2 virus, its regulation in relation to mitochondrial function may have important clinical implications.


Subject(s)
Angiotensin-Converting Enzyme 2 , COVID-19 , Lipid Metabolism Disorders , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/genetics , COVID-19/metabolism , DNA, Mitochondrial/genetics , DNA, Mitochondrial/metabolism , Lipid Metabolism , Lipid Metabolism Disorders/genetics , Lipid Metabolism Disorders/metabolism , Lipid Metabolism Disorders/virology , Mice , Mice, Knockout , Mitochondria/genetics , Mitochondria/metabolism , Muscle, Skeletal/metabolism , SARS-CoV-2 , Up-Regulation
11.
J Am Soc Nephrol ; 33(3): 565-582, 2022 03.
Article in English | MEDLINE | ID: covidwho-1883777

ABSTRACT

BACKGROUND: Endothelial cell injury is a common nidus of renal injury in patients and consistent with the high prevalence of AKI reported during the coronavirus disease 2019 pandemic. This cell type expresses integrin α5 (ITGA5), which is essential to the Tie2 signaling pathway. The microRNA miR-218-5p is upregulated in endothelial progenitor cells (EPCs) after hypoxia, but microRNA regulation of Tie2 in the EPC lineage is unclear. METHODS: We isolated human kidney-derived EPCs (hkEPCs) and surveyed microRNA target transcripts. A preclinical model of ischemic kidney injury was used to evaluate the effect of hkEPCs on capillary repair. We used a genetic knockout model to evaluate the effect of deleting endogenous expression of miR-218 specifically in angioblasts. RESULTS: After ischemic in vitro preconditioning, miR-218-5p was elevated in hkEPCs. We found miR-218-5p bound to ITGA5 mRNA transcript and decreased ITGA5 protein expression. Phosphorylation of 42/44 MAPK decreased by 73.6% in hkEPCs treated with miR-218-5p. Cells supplemented with miR-218-5p downregulated ITGA5 synthesis and decreased 42/44 MAPK phosphorylation. In a CD309-Cre/miR-218-2-LoxP mammalian model (a conditional knockout mouse model designed to delete pre-miR-218-2 exclusively in CD309+ cells), homozygotes at e18.5 contained avascular glomeruli, whereas heterozygote adults showed susceptibility to kidney injury. Isolated EPCs from the mouse kidney contained high amounts of ITGA5 and showed decreased migratory capacity in three-dimensional cell culture. CONCLUSIONS: These results demonstrate the critical regulatory role of miR-218-5p in kidney EPC migration, a finding that may inform efforts to treat microvascular kidney injury via therapeutic cell delivery.


Subject(s)
Acute Kidney Injury/etiology , Acute Kidney Injury/metabolism , Endothelial Progenitor Cells/metabolism , Endothelial Progenitor Cells/pathology , Integrin alpha5/metabolism , MicroRNAs/physiology , Acute Kidney Injury/pathology , Animals , Disease Models, Animal , Humans , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptor, TIE-2/physiology , Signal Transduction/physiology
12.
BMC Immunol ; 23(1): 25, 2022 05 23.
Article in English | MEDLINE | ID: covidwho-1857991

ABSTRACT

BACKGROUND: Signal transducer and activator of transcription 6 (STAT6) is an intracelluar transcriotion factor and NLRP3 (Nod-like receptor containing a pyrin domain 3) is a component of NLRP3 inflammasome in pyroptotic cells. There was increased activation of STAT6 and expression of NLRP3 in mice with murine acute lung injury (ALI). However, it is unknown their roles in the development of murine ALI. We in this study, investigated the effects of STAT6 signaling on murine ALI and pyroptosis in STAT6 knock-out (KO) mice and macrophages. RESULTS: STAT6 was activated in the lung tissues of mice 2 days after intratracheal treatmemt with 5 mg/kg LPS. Lack of STAT6 expression in KO mice induced more severe lung inflammation, associated with elevated neutrophil influx and expression of TNF-alpha, IL-6 and IL-1beta in the inflamed lung tissues. In addition, the expression of NLRP3, ASC (apoptosis-associated speck-like protein containing a CARD), p-p38 MAPK (p38 mitogen-activated protein kinase) and ratio of LC3-II/I (microtubule-associated protein-1 light chain-3) was increased, accompanied with the increased polarization of Siglec-F(-) subtype macrophages in KO mice with ALI. Further studies in bone marrow-derived macrophages (BMDMs) revealed that lack of STAT6 increased the expression of NLRP3 and p-p38 MAPK, in association with elevated expression of TNF-alpha, IL-1beta and Calreticulin in LPS-treated KO BMDMs. CONCLUSIONS: Lack of STAT6 exacerbated murine ALI through improving the expression of NLRP3 and activation of p38 MAPK in macrophages. STAT6 has an immune suppressive role in the development of ALI and would be a promising therapeutic target in the treatment of ALI and possibly among patients with acute respiratory distress syndrome (ARDS).


Subject(s)
Acute Lung Injury , NLR Family, Pyrin Domain-Containing 3 Protein , Acute Lung Injury/drug therapy , Acute Lung Injury/metabolism , Animals , Humans , Inflammasomes/metabolism , Lipopolysaccharides/pharmacology , Macrophages , Mice , Mice, Inbred C57BL , Mice, Knockout , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , STAT6 Transcription Factor/genetics , STAT6 Transcription Factor/metabolism , STAT6 Transcription Factor/pharmacology , Signal Transduction , Tumor Necrosis Factor-alpha/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism
13.
Proc Natl Acad Sci U S A ; 119(21): e2202012119, 2022 05 24.
Article in English | MEDLINE | ID: covidwho-1852638

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS­CoV-2) is a worldwide health concern, and new treatment strategies are needed. Targeting inflammatory innate immunity pathways holds therapeutic promise, but effective molecular targets remain elusive. Here, we show that human caspase-4 (CASP4) and its mouse homolog, caspase-11 (CASP11), are up-regulated in SARS­CoV-2 infections and that CASP4 expression correlates with severity of SARS­CoV-2 infection in humans. SARS­CoV-2­infected Casp11−/− mice were protected from severe weight loss and lung pathology, including blood vessel damage, compared to wild-type (WT) mice and mice lacking the caspase downstream effector gasdermin-D (Gsdmd−/−). Notably, viral titers were similar regardless of CASP11 knockout. Global transcriptomics of SARS­CoV-2­infected WT, Casp11−/−, and Gsdmd−/− lungs identified restrained expression of inflammatory molecules and altered neutrophil gene signatures in Casp11−/− mice. We confirmed that protein levels of inflammatory mediators interleukin (IL)-1ß, IL-6, and CXCL1, as well as neutrophil functions, were reduced in Casp11−/− lungs. Additionally, Casp11−/− lungs accumulated less von Willebrand factor, a marker for endothelial damage, but expressed more Kruppel-Like Factor 2, a transcription factor that maintains vascular integrity. Overall, our results demonstrate that CASP4/11 promotes detrimental SARS­CoV-2­induced inflammation and coagulopathy, largely independently of GSDMD, identifying CASP4/11 as a promising drug target for treatment and prevention of severe COVID-19.


Subject(s)
COVID-19 , Caspases, Initiator/metabolism , SARS-CoV-2 , Thromboinflammation , Animals , COVID-19/enzymology , COVID-19/pathology , Caspases, Initiator/genetics , Disease Progression , Humans , Lung/pathology , Mice , Mice, Knockout , Severity of Illness Index , Thromboinflammation/enzymology , Thromboinflammation/genetics
14.
Viruses ; 14(5)2022 05 05.
Article in English | MEDLINE | ID: covidwho-1820422

ABSTRACT

SARS-CoV-2 variants, including B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), and B.1.617.2 (Delta) variants, have displayed increased transmissibility and, therefore, have been categorized as variants of concern (VOCs). The pervasiveness of VOCs suggests a high probability of future mutations that may lead to increased virulence. Prior reports have shown that VOC infection without expression of human angiotensin converting enzyme-2 receptor (hACE2) in mice is possible. We sought to understand if the increased transmissibility of VOCs can infect C57BL/6 mice without expression of hACE2 receptor required for entry of SARS-CoV-2 normally. We examined the ability of infection with Beta and Gamma variants to infect and cause both pathological and clinical changes consistent with severe COVID-19, including body weight changes, survival, subgenomic viral titer, lung histology on Hematoxylin and Eosin (H&E) staining, and viral protein expression as measured by immunohistochemistry staining of viral antigen (IHC). These methods were used to examine three groups of mice: C57BL6, Rag2-/-, and Ccr2-/- mice. We observed that these mice, infected with Beta and Gamma variants of SARS-CoV-2, did not show pathological changes as indicated by weight loss, altered survival, or significant lung pathology on H&E staining. Subgenomic qPCR and IHC staining for viral protein indicated that there was some evidence of infection but far below ACE2 transgenic mice, which showed clinical disease and pathologic changes consistent with ARDS. These data suggest that these variants replicate poorly even in the setting of profound immune deficiency.


Subject(s)
COVID-19 , Disease Models, Animal , SARS-CoV-2 , Angiotensin-Converting Enzyme 2 , Animals , COVID-19/virology , Humans , Mice , Mice, Inbred C57BL , Mice, Knockout , SARS-CoV-2/genetics , Viral Proteins
15.
Kidney360 ; 2(7): 1095-1106, 2021 07 29.
Article in English | MEDLINE | ID: covidwho-1776832

ABSTRACT

Background: The actions of angiotensin-converting enzyme 2 (ACE2) oppose those of the renin-angiotensin-aldosterone system. ACE2 may be a cytoprotectant in some tissues. This study examined ACE2 expression in models of AKI. Methods: ACE2 mRNA and protein expression and ACE2 activity were assessed in murine ischemic AKI. Renal ACE2 mRNA expression was evaluated in LPS-induced AKI in wild-type (C57BL/6J) mice, in heme oxygenase-1+/+ and heme oxygenase-1-/- mice, and after unilateral ureteral obstruction (UUO) in wild-type mice. The effect of sex and age on renal ACE2 protein expression was also assessed. Results: In ischemic AKI, ACE2 mRNA and protein expression and ACE2 activity were reduced as compared with such indices in the intact kidney. In ischemic AKI, ACE2, which, in health, is prominently expressed in the tubular epithelium, especially proximal tubules, is decreased in expression in these segments. Decreased ACE2 expression in AKI did not reflect reduced GFR, because ACE2 mRNA expression was unaltered after UUO. LPS induced renal ACE2 mRNA expression in wild-type mice, but this effect did not occur in heme oxygenase-1-deficient mice. In ischemic and LPS-induced AKI, renal expression of the Mas receptor was increased. In the intact kidney, renal ACE2 protein expression decreased in female mice as compared with male mice, but was unaltered with age. Conclusion: We conclude that renal ACE2 expression is decreased in ischemic AKI, characterized by decreased GFR and abundant cell death, but is upregulated in LPS-induced AKI, an effect requiring heme oxygenase-1. Determining the significance of ACE2 expression in experimental AKI merits further study. We suggest that understanding the mechanism underlying ACE2 downregulation in AKI may offer insights relevant to COVID-19: ACE2 expression is downregulated after ACE2 mediates SARS-CoV-2 cellular entry; such downregulation is proinflammatory; and AKI commonly occurs and determines outcomes in COVID-19.


Subject(s)
Acute Kidney Injury , Angiotensin-Converting Enzyme 2 , Acute Kidney Injury/genetics , Angiotensin-Converting Enzyme 2/genetics , Animals , Female , Kidney , Male , Mice , Mice, Inbred C57BL , Mice, Knockout
16.
Mamm Genome ; 33(1): 143-156, 2022 03.
Article in English | MEDLINE | ID: covidwho-1767484

ABSTRACT

Mouse models are essential for dissecting disease mechanisms and defining potential drug targets. There are more than 18,500 mouse strains available for research communities in National Resource Center for Mutant Mice (NRCMM) of China, affiliated with Model Animal Research Center of Nanjing University and Gempharmatech Company. In 2019, Gempharmatech launched the Knockout All Project (KOAP) aiming to generate null mutants and gene floxed strains for all protein-coding genes in mouse genome within 5 years. So far, KOAP has generated 8,004 floxed strains and 9,769 KO (knockout) strains (updated to Oct, 2021). NRCMM also created hundreds of Cre transgenic lines, mutant knock-in models, immuno-deficient models, and humanized mouse models. As a member of the international mouse phenotyping consortium (IMPC), NRCMM provides comprehensive phenotyping services for mouse models. In summary, NRCMM will continue to support biomedical community with new mouse models as well as related services.


Subject(s)
Genome , Animals , China , Disease Models, Animal , Humans , Mice , Mice, Knockout , Phenotype
17.
Hum Cell ; 35(3): 871-884, 2022 May.
Article in English | MEDLINE | ID: covidwho-1762779

ABSTRACT

Mechanical ventilation may cause ventilator-induced lung injury (VILI) in patients requiring ventilator support. Inhibition of autophagy is an important approach to ameliorate VILI as it always enhances lung injury after exposure to various stress agents. This study aimed to further reveal the potential mechanisms underlying the effects of geranylgeranyl diphosphate synthase large subunit 1 (GGPPS1) knockout and autophagy in VILI using C57BL/6 mice with lung-specific GGPPS1 knockout that were subjected to mechanical ventilation. The results demonstrate that GGPPS1 knockout mice exhibit significantly attenuated VILI based on the histologic score, the lung wet-to-dry ratio, total protein levels, neutrophils in bronchoalveolar lavage fluid, and reduced levels of inflammatory cytokines. Importantly, the expression levels of autophagy markers were obviously decreased in GGPPS1 knockout mice compared with wild-type mice. The inhibitory effects of GGPPS1 knockout on autophagy were further confirmed by measuring the ultrastructural change of lung tissues under transmission electron microscopy. In addition, knockdown of GGPPS1 in RAW264.7 cells reduced cyclic stretch-induced inflammation and autophagy. The benefits of GGPPS1 knockout for VILI can be partially eliminated through treatment with rapamycin. Further analysis revealed that Rab37 was significantly downregulated in GGPPS1 knockout mice after mechanical ventilation, while it was highly expressed in the control group. Simultaneously, Rab37 overexpression significantly enhances autophagy in cells that are treated with cyclin stretch, including GGPPS1 knockout cells. Collectively, our results indicate that GGPPS1 knockout results in reduced expression of Rab37 proteins, further restraining autophagy and VILI.


Subject(s)
Ventilator-Induced Lung Injury , Animals , Autophagy/genetics , Dimethylallyltranstransferase , Farnesyltranstransferase , Geranyltranstransferase , Humans , Lung/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Ventilator-Induced Lung Injury/genetics , Ventilator-Induced Lung Injury/metabolism , Ventilator-Induced Lung Injury/pathology , rab GTP-Binding Proteins/genetics , rab GTP-Binding Proteins/metabolism
18.
Life Sci Alliance ; 5(6)2022 06.
Article in English | MEDLINE | ID: covidwho-1732625

ABSTRACT

Inflammasomes are cytosolic innate immune sensors of pathogen infection and cellular damage that induce caspase-1-mediated inflammation upon activation. Although inflammation is protective, uncontrolled excessive inflammation can cause inflammatory diseases and can be detrimental, such as in coronavirus disease (COVID-19). However, the underlying mechanisms that control inflammasome activation are incompletely understood. Here we report that the leucine-rich repeat (LRR) protein ribonuclease inhibitor (RNH1), which shares homology with LRRs of NLRP (nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing) proteins, attenuates inflammasome activation. Deletion of RNH1 in macrophages increases interleukin (IL)-1ß production and caspase-1 activation in response to inflammasome stimulation. Mechanistically, RNH1 decreases pro-IL-1ß expression and induces proteasome-mediated caspase-1 degradation. Corroborating this, mouse models of monosodium urate (MSU)-induced peritonitis and lipopolysaccharide (LPS)-induced endotoxemia, which are dependent on caspase-1, respectively, show increased neutrophil infiltration and lethality in Rnh1 -/- mice compared with wild-type mice. Furthermore, RNH1 protein levels were negatively related with disease severity and inflammation in hospitalized COVID-19 patients. We propose that RNH1 is a new inflammasome regulator with relevance to COVID-19 severity.


Subject(s)
COVID-19/pathology , Carrier Proteins/metabolism , Inflammasomes/metabolism , Leucine-Rich Repeat Proteins/metabolism , Animals , COVID-19/immunology , Caspase 1/metabolism , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , NF-kappa B/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Patient Acuity , Proteasome Endopeptidase Complex/metabolism
19.
Am J Respir Cell Mol Biol ; 66(3): 323-336, 2022 03.
Article in English | MEDLINE | ID: covidwho-1714501

ABSTRACT

Administration of high concentrations of oxygen (hyperoxia) is one of few available options to treat acute hypoxemia-related respiratory failure, as seen in the current coronavirus disease (COVID-19) pandemic. Although hyperoxia can cause acute lung injury through increased production of superoxide anion (O2•-), the choice of high-concentration oxygen administration has become a necessity in critical care. The objective of this study was to test the hypothesis that UCP2 (uncoupling protein 2) has a major function of reducing O2•- generation in the lung in ambient air or in hyperoxia. Lung epithelial cells and wild-type; UCP2-/-; or transgenic, hTrx overexpression-bearing mice (Trx-Tg) were exposed to hyperoxia and O2•- generation was measured by using electron paramagnetic resonance, and lung injury was measured by using histopathologic analysis. UCP2 expression was analyzed by using RT-PCR analysis, Western blotting analysis, and RNA interference. The signal transduction pathways leading to loss of UCP2 expression were analyzed by using IP, phosphoprotein analysis, and specific inhibitors. UCP2 mRNA and protein expression were acutely decreased in hyperoxia, and these decreases were associated with a significant increase in O2•- production in the lung. Treatment of cells with rhTrx (recombinant human thioredoxin) or exposure of Trx-Tg mice prevented the loss of UCP2 protein and decreased O2•- generation in the lung. Trx is also required to maintain UCP2 expression in normoxia. Loss of UCP2 in UCP2-/- mice accentuated lung injury in hyperoxia. Trx activates the MKK4-p38MAPK (p38 mitogen-activated protein kinase)-PGC1α (PPARγ [peroxisome proliferator-activated receptor γ] coactivator 1α) pathway, leading to rescue of UCP2 and decreased O2•- generation in hyperoxia. Loss of UCP2 in hyperoxia is a major mechanism of O2•- production in the lung in hyperoxia. rhTrx can protect against lung injury in hyperoxia due to rescue of the loss of UCP2.


Subject(s)
Lung/metabolism , Oxygen/metabolism , Thioredoxins/metabolism , Uncoupling Protein 2/metabolism , Animals , COVID-19/metabolism , COVID-19/therapy , Cell Line , Humans , Hyperoxia/metabolism , Lung/cytology , MAP Kinase Kinase 4/genetics , MAP Kinase Kinase 4/metabolism , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Oxygen/toxicity , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/genetics , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Phosphorylation , Signal Transduction , Superoxides/metabolism , Thioredoxins/genetics , Thioredoxins/pharmacology , Uncoupling Protein 2/genetics , p38 Mitogen-Activated Protein Kinases/genetics , p38 Mitogen-Activated Protein Kinases/metabolism
20.
Pharmacol Res Perspect ; 10(2): e00940, 2022 04.
Article in English | MEDLINE | ID: covidwho-1712175

ABSTRACT

Anti-proinflammatory cytokine therapies against interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1 are major advancements in treating inflammatory diseases, especially rheumatoid arthritis. Such therapies are mainly performed by injection of antibodies against cytokines or cytokine receptors. We initially found that the glycolytic inhibitor 2-deoxy-d-glucose (2-DG), a simple monosaccharide, attenuated cellular responses to IL-6 by inhibiting N-linked glycosylation of the IL-6 receptor gp130. Aglycoforms of gp130 did not bind to IL-6 or activate downstream intracellular signals that included Janus kinases. 2-DG completely inhibited dextran sodium sulfate-induced colitis, a mouse model for inflammatory bowel disease, and alleviated laminarin-induced arthritis in the SKG mouse, an experimental model for human rheumatoid arthritis. These diseases have been shown to be partially dependent on IL-6. We also found that 2-DG inhibited signals for other proinflammatory cytokines such as TNF-α, IL-1ß, and interferon -γ, and accordingly, prevented death by another inflammatory disease, lipopolysaccharide (LPS) shock. Furthermore, 2-DG prevented LPS shock, a model for a cytokine storm, and LPS-induced pulmonary inflammation, a model for acute respiratory distress syndrome of coronavirus disease 2019 (COVID-19). These results suggest that targeted therapies that inhibit cytokine receptor glycosylation are effective for treatment of various inflammatory diseases.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Deoxyglucose/pharmacology , Glycosylation/drug effects , Inflammation/prevention & control , Receptors, Cytokine/drug effects , Animals , Cells, Cultured , Cytokine Receptor gp130/antagonists & inhibitors , Cytokine Receptor gp130/metabolism , Cytokine Release Syndrome/prevention & control , Cytokines/metabolism , Inflammation/chemically induced , Janus Kinases/drug effects , Lipopolysaccharides , Mice , Mice, Inbred C57BL , Mice, Knockout , Receptors, Cytokine/immunology , Receptors, Cytokine/metabolism , Receptors, Interleukin-6/antagonists & inhibitors , Receptors, Interleukin-6/genetics , Receptors, Interleukin-6/metabolism
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