Publications by authors named "Bethany B Moore"

173 Publications

Inhibition of macrophage histone demethylase JMJD3 protects against abdominal aortic aneurysms.

J Exp Med 2021 Jun;218(6)

Section of Vascular Surgery, Department of Surgery, University of Michigan, Ann Arbor, MI.

Abdominal aortic aneurysms (AAAs) are a life-threatening disease for which there is a lack of effective therapy preventing aortic rupture. During AAA formation, pathological vascular remodeling is driven by macrophage infiltration, and the mechanisms regulating macrophage-mediated inflammation remain undefined. Recent evidence suggests that an epigenetic enzyme, JMJD3, plays a critical role in establishing macrophage phenotype. Using single-cell RNA sequencing of human AAA tissues, we identified increased JMJD3 in aortic monocyte/macrophages resulting in up-regulation of an inflammatory immune response. Mechanistically, we report that interferon-β regulates Jmjd3 expression via JAK/STAT and that JMJD3 induces NF-κB-mediated inflammatory gene transcription in infiltrating aortic macrophages. In vivo targeted inhibition of JMJD3 with myeloid-specific genetic depletion (JMJD3f/fLyz2Cre+) or pharmacological inhibition in the elastase or angiotensin II-induced AAA model preserved the repressive H3K27me3 on inflammatory gene promoters and markedly reduced AAA expansion and attenuated macrophage-mediated inflammation. Together, our findings suggest that cell-specific pharmacologic therapy targeting JMJD3 may be an effective intervention for AAA expansion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1084/jem.20201839DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8008365PMC
June 2021

Blood Transcriptomic Predicts Progression of Pulmonary Fibrosis and Associates Natural Killer Cells.

Am J Respir Crit Care Med 2021 Mar 9. Epub 2021 Mar 9.

University of Virginia, 2358, Division of Pulmonary & Critical Care & Sleep Medicine, Department of Medicine, , Charlottesville, Virginia, United States;

Disease activity in idiopathic pulmonary fibrosis (IPF) remains highly variable, poorly understood, and difficult to predict. To identify a predictor using short-term longitudinal changes in gene-expression that forecasts future forced vital capacity (FVC) decline and to characterize involved pathways and cell types. Seventy-four patients from Correlating Outcomes with biochemical Markers to Estimate Time-progression in IPF (COMET) cohort were dichotomized as progressors (≥10% FVC decline) or stable. Blood gene-expression changes within individuals were calculated between baseline and 4 months, and regressed with future FVC status, allowing determination of expression variations, sample size, and statistical power. Pathway analyses were conducted to predict downstream effects and identify new targets. An FVC-predictor for progression was constructed in COMET and validated using independent cohorts. Peripheral blood mononuclear single-cell RNA-seq (PBMC scRNA-seq) data from healthy controls were used as references to characterize cell type compositions from bulk PBMC RNA-seq data that were associated with FVC decline. The longitudinal model reduced gene-expression variations within stable and progressor groups, resulting in increased statistical power when compared to a cross-sectional model. The FVC-predictor for progression anticipated patients with future FVC decline with 78% sensitivity and 86% specificity across independent IPF cohorts. Pattern recognition receptor pathways and mTOR pathways were down- and up-regulated, respectively. Cellular deconvolution using scRNA-seq data identified natural killer (NK) cells as significantly correlated with progression. Serial transcriptomic change predicts future FVC decline. Analysis of cell types involved in the progressor signature supports the novel involvement of NK cells in IPF progression.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1164/rccm.202008-3093OCDOI Listing
March 2021

Elevated inflammatory responses and targeted therapeutic intervention in a preclinical mouse model of ataxia-telangiectasia lung disease.

Sci Rep 2021 Feb 19;11(1):4268. Epub 2021 Feb 19.

Department of Internal Medicine, University of Michigan, 109 Zina Pitcher Place, 2063 BSRB, Box 2200, Ann Arbor, MI, 48109, USA.

Ataxia-telangiectasia (A-T) is an autosomal recessive, multisystem disorder characterized by cerebellar degeneration, cancer predisposition, and immune system defects. A major cause of mortality in A-T patients is severe pulmonary disease; however, the underlying causes of the lung complications are poorly understood, and there are currently no curative therapeutic interventions. In this study, we examined the lung phenotypes caused by ATM-deficient immune cells using a mouse model of A-T pulmonary disease. In response to acute lung injury, ATM-deficiency causes decreased survival, reduced blood oxygen saturation, elevated neutrophil recruitment, exaggerated and prolonged inflammatory responses and excessive lung injury compared to controls. We found that ATM null bone marrow adoptively transferred to WT recipients induces similar phenotypes that culminate in impaired lung function. Moreover, we demonstrated that activated ATM-deficient macrophages exhibit significantly elevated production of harmful reactive oxygen and nitrogen species and pro-inflammatory cytokines. These findings indicate that ATM-deficient immune cells play major roles in causing the lung pathologies in A-T. Based on these results, we examined the impact of inhibiting the aberrant inflammatory responses caused by ATM-deficiency with reparixin, a CXCR1/CXCR2 chemokine receptor antagonist. We demonstrated that reparixin treatment reduces neutrophil recruitment, edema and tissue damage in ATM mutant lungs. Thus, our findings indicate that targeted inhibition of CXCR1/CXCR2 attenuates pulmonary phenotypes caused by ATM-deficiency and suggest that this treatment approach represents a viable therapeutic strategy for A-T lung disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-021-83531-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7895952PMC
February 2021

Stem cell transplantation uncovers TDO-AHR regulation of lung dendritic cells in herpesvirus-induced pathology.

JCI Insight 2021 Jan 25;6(2). Epub 2021 Jan 25.

Division of Pulmonary & Critical Care Medicine, Department of Internal Medicine, and.

The aryl-hydrocarbon receptor (AHR) is an intracellular sensor of aromatic hydrocarbons that sits at the top of various immunomodulatory pathways. Here, we present evidence that AHR plays a role in controlling IL-17 responses and the development of pulmonary fibrosis in response to respiratory pathogens following bone marrow transplant (BMT). Mice infected intranasally with gamma-herpesvirus 68 (γHV-68) following BMT displayed elevated levels of the AHR ligand, kynurenine (kyn), in comparison with control mice. Inhibition or genetic ablation of AHR signaling resulted in a significant decrease in IL-17 expression as well as a reduction in lung pathology. Lung CD103+ DCs expressed AHR following BMT, and treatment of induced CD103+ DCs with kyn resulted in altered cytokine production in response to γHV-68. Interestingly, mice deficient in the kyn-producing enzyme indolamine 2-3 dioxygenase showed no differences in cytokine responses to γHV-68 following BMT; however, isolated pulmonary fibroblasts infected with γHV-68 expressed the kyn-producing enzyme tryptophan dioxygenase (TDO2). Our data indicate that alterations in the production of AHR ligands in response to respiratory pathogens following BMT results in a pro-Th17 phenotype that drives lung pathology. We have further identified the TDO2/AHR axis as a potentially novel form of intercellular communication between fibroblasts and DCs that shapes immune responses to respiratory pathogens.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/jci.insight.139965DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7934859PMC
January 2021

CCR2 Mediates Chronic LPS-Induced Pulmonary Inflammation and Hypoalveolarization in a Murine Model of Bronchopulmonary Dysplasia.

Front Immunol 2020 6;11:579628. Epub 2020 Oct 6.

Division of Pediatric Pulmonology, Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI, United States.

The histopathology of bronchopulmonary dysplasia (BPD) includes hypoalveolarization and interstitial thickening due to abnormal myofibroblast accumulation. Chorioamnionitis and sepsis are major risk factors for BPD development. The cellular mechanisms leading to these lung structural abnormalities are poorly understood. We used an animal model with repeated lipopolysaccharide (LPS) administration into the airways of immature mice to simulate prolonged airway exposure to gram-negative bacteria, focusing on the role of C-C chemokine receptor type 2-positive (CCR2+) exudative macrophages (ExMf). Repetitive LPS exposure of immature mice induced persistent hypoalveolarization observed at 4 and 18 days after the last LPS administration. LPS upregulated the expression of lung pro-inflammatory cytokines (TNF-, IL-17a, IL-6, IL-1) and chemokines (CCL2, CCL7, CXCL1, and CXCL2), while the expression of genes involved in lung alveolar and mesenchymal cell development (PDGFR-, FGF7, FGF10, and SPRY1) was decreased. LPS induced recruitment of ExMf, including CCR2+ ExMf, as well as other myeloid cells like DCs and neutrophils. Lungs of LPS-exposed CCR2-/- mice showed preserved alveolar structure and normal patterns of -actin and PDGFR expression at the tips of the secondary alveolar crests. Compared to wild type mice, a significantly lower number of ExMf, including TNF-+ ExMf were recruited to the lungs of CCR2-/- mice following repetitive LPS exposure. Further, pharmacological inhibition of TLR4 with TAK-242 also blocked the effect of LPS on alveolarization, -SMA and PDGFR expression. TNF- and IL-17a induced -smooth muscle actin expression in the distal airspaces of E16 fetal mouse lung explants. In human preterm lung mesenchymal stromal cells, TNF- reduced mRNA and protein expression of PDGFR- and decreased mRNA expression of WNT2, FOXF2, and SPRY1. Collectively, our findings demonstrate that in immature mice repetitive LPS exposure, through TLR4 signaling increases lung inflammation and impairs lung alveolar growth in a CCR2-dependent manner.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2020.579628DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7573800PMC
October 2020

Modulating lung immune cells by pulmonary delivery of antigen-specific nanoparticles to treat autoimmune disease.

Sci Adv 2020 Oct 16;6(42). Epub 2020 Oct 16.

Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.

Antigen-specific particles can treat autoimmunity, and pulmonary delivery may provide for easier delivery than intravenous or subcutaneous routes. The lung is a "hub" for autoimmunity where autoreactive T cells pass before arriving at disease sites. Here, we report that targeting lung antigen-presenting cells (APCs) via antigen-loaded poly(lactide--glycolide) particles modulates lung CD4 T cells to tolerize murine experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Particles directly delivered to the lung via intratracheal administration demonstrated more substantial reduction in EAE severity when compared with particles delivered to the liver and spleen via intravenous administration. Intratracheally delivered particles were associated with lung APCs and decreased costimulatory molecule expression on the APCs, which inhibited CD4 T cell proliferation and reduced their population in the central nervous system while increasing them in the lung. This study supports noninvasive pulmonary particle delivery, such as inhalable administration, to treat autoimmune disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/sciadv.abc9317DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7567592PMC
October 2020

Microengineered 3D pulmonary interstitial mimetics highlight a critical role for matrix degradation in myofibroblast differentiation.

Sci Adv 2020 Sep 9;6(37). Epub 2020 Sep 9.

Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.

Fibrosis, characterized by aberrant tissue scarring from activated myofibroblasts, is often untreatable. Although the extracellular matrix becomes increasingly stiff and fibrous during disease progression, how these physical cues affect myofibroblast differentiation in 3D is poorly understood. Here, we describe a multicomponent hydrogel that recapitulates the 3D fibrous structure of interstitial tissue regions where idiopathic pulmonary fibrosis (IPF) initiates. In contrast to findings on 2D hydrogels, myofibroblast differentiation in 3D was inversely correlated with hydrogel stiffness but positively correlated with matrix fibers. Using a multistep bioinformatics analysis of IPF patient transcriptomes and in vitro pharmacologic screening, we identify matrix metalloproteinase activity to be essential for 3D but not 2D myofibroblast differentiation. Given our observation that compliant degradable 3D matrices amply support fibrogenesis, these studies demonstrate a departure from the established relationship between stiffness and myofibroblast differentiation in 2D, and provide a new 3D model for studying fibrosis and identifying antifibrotic therapeutics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/sciadv.abb5069DOI Listing
September 2020

Epigenetic regulation of the PGE2 pathway modulates macrophage phenotype in normal and pathologic wound repair.

JCI Insight 2020 09 3;5(17). Epub 2020 Sep 3.

Section of Vascular Surgery, Department of Surgery.

Macrophages are a primary immune cell involved in inflammation, and their cell plasticity allows for transition from an inflammatory to a reparative phenotype and is critical for normal tissue repair following injury. Evidence suggests that epigenetic alterations play a critical role in establishing macrophage phenotype and function during normal and pathologic wound repair. Here, we find in human and murine wound macrophages that cyclooxygenase 2/prostaglandin E2 (COX-2/PGE2) is elevated in diabetes and regulates downstream macrophage-mediated inflammation and host defense. Using single-cell RNA sequencing of human wound tissue, we identify increased NF-κB-mediated inflammation in diabetic wounds and show increased COX-2/PGE2 in diabetic macrophages. Further, we identify that COX-2/PGE2 production in wound macrophages requires epigenetic regulation of 2 key enzymes in the cytosolic phospholipase A2/COX-2/PGE2 (cPLA2/COX-2/PGE2) pathway. We demonstrate that TGF-β-induced miRNA29b increases COX-2/PGE2 production via inhibition of DNA methyltransferase 3b-mediated hypermethylation of the Cox-2 promoter. Further, we find mixed-lineage leukemia 1 (MLL1) upregulates cPLA2 expression and drives COX-2/PGE2. Inhibition of the COX-2/PGE2 pathway genetically (Cox2fl/fl Lyz2Cre+) or with a macrophage-specific nanotherapy targeting COX-2 in tissue macrophages reverses the inflammatory macrophage phenotype and improves diabetic tissue repair. Our results indicate the epigenetically regulated PGE2 pathway controls wound macrophage function, and cell-targeted manipulation of this pathway is feasible to improve diabetic wound repair.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/jci.insight.138443DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7526451PMC
September 2020

The evolving role of the lung microbiome in pulmonary fibrosis.

Am J Physiol Lung Cell Mol Physiol 2020 10 2;319(4):L675-L682. Epub 2020 Sep 2.

Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan.

Mucosal surfaces are constantly exposed to a microbiome consisting of microorganisms that heavily influence human immunity and health. In the lung these microorganisms consist of bacteria, viruses, and fungi and exist in a relatively low biomass state. Bacterial communities of the lung modulate local inflammation and correlate with changes in pulmonary physiology and clinical outcomes in patients with lung disease. Instrumental to this progress has been the study of these bacterial communities in the pathogenesis of pulmonary fibrosis, a fatal and progressive disease culminating in respiratory failure. Key pathophysiological mechanisms in pulmonary fibrosis include recurrent idiopathic alveolar epithelial injury, unchecked collagen deposition, mucociliary dysfunction due to muc5b overexpression, hypoxia, and altered host defense. These key mechanisms and their related consequences promote severe progressive architectural lung destruction and loss of local homeostasis. As such, pulmonary fibrosis is an appropriate target disease for the study of the lung microbiome. Herein, we discuss recent advances in our understanding of the role of the lung microbiome in the pathogenesis of pulmonary fibrosis. We highlight fundamental clinical observations and mechanistic insights and identify crucial areas for further discovery science. An improved understanding of how the lung microbiome acts to influence outcomes in patients with pulmonary fibrosis will lead to enhanced therapies for this devastating lung disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/ajplung.00258.2020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7642898PMC
October 2020

Identification of a unique temporal signature in blood and BAL associated with IPF progression.

Sci Rep 2020 07 21;10(1):12049. Epub 2020 Jul 21.

Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109 , USA.

Idiopathic pulmonary fibrosis (IPF) is a progressive and heterogeneous interstitial lung disease of unknown origin with a low survival rate. There are few treatment options available due to the fact that mechanisms underlying disease progression are not well understood, likely because they arise from dysregulation of complex signaling networks spanning multiple tissue compartments. To better characterize these networks, we used systems-focused data-driven modeling approaches to identify cross-tissue compartment (blood and bronchoalveolar lavage) and temporal proteomic signatures that differentiated IPF progressors and non-progressors. Partial least squares discriminant analysis identified a signature of 54 baseline (week 0) blood and lung proteins that differentiated IPF progression status by the end of 80 weeks of follow-up with 100% cross-validation accuracy. Overall we observed heterogeneous protein expression patterns in progressors compared to more homogenous signatures in non-progressors, and found that non-progressors were enriched for proteomic processes involving regulation of the immune/defense response. We also identified a temporal signature of blood proteins that was significantly different at early and late progressor time points (p < 0.0001), but not present in non-progressors. Overall, this approach can be used to generate new hypothesis for mechanisms associated with IPF progression and could readily be translated to other complex and heterogeneous diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-67956-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7374599PMC
July 2020

Alveolar macrophage-derived extracellular vesicles inhibit endosomal fusion of influenza virus.

EMBO J 2020 08 9;39(16):e105057. Epub 2020 Jul 9.

Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA.

Alveolar macrophages (AMs) and epithelial cells (ECs) are the lone resident lung cells positioned to respond to pathogens at early stages of infection. Extracellular vesicles (EVs) are important vectors of paracrine signaling implicated in a range of (patho)physiologic contexts. Here we demonstrate that AMs, but not ECs, constitutively secrete paracrine activity localized to EVs which inhibits influenza infection of ECs in vitro and in vivo. AMs exposed to cigarette smoke extract lost the inhibitory activity of their secreted EVs. Influenza strains varied in their susceptibility to inhibition by AM-EVs. Only those exhibiting early endosomal escape and high pH of fusion were inhibited via a reduction in endosomal pH. By contrast, strains exhibiting later endosomal escape and lower fusion pH proved resistant to inhibition. These results extend our understanding of how resident AMs participate in host defense and have broader implications in the defense and treatment of pathogens internalized within endosomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.15252/embj.2020105057DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7429743PMC
August 2020

Master manipulators: how herpesviruses alter immune responses to RSV.

Mucosal Immunol 2020 09 11;13(5):715-716. Epub 2020 Jun 11.

Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41385-020-0313-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7289069PMC
September 2020

The Role of HHV-6 in Idiopathic Pulmonary Fibrosis Remains to Be Determined.

Chest 2020 Jun;157(6):1681-1682

Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Ann Arbor, MI; Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chest.2020.01.018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7403750PMC
June 2020

Multi-scale models of lung fibrosis.

Matrix Biol 2020 09 11;91-92:35-50. Epub 2020 May 11.

Department of Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA; Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, VA 22908, USA. Electronic address:

The architectural complexity of the lung is crucial to its ability to function as an organ of gas exchange; the branching tree structure of the airways transforms the tracheal cross-section of only a few square centimeters to a blood-gas barrier with a surface area of tens of square meters and a thickness on the order of a micron or less. Connective tissue comprised largely of collagen and elastic fibers provides structural integrity for this intricate and delicate system. Homeostatic maintenance of this connective tissue, via a balance between catabolic and anabolic enzyme-driven processes, is crucial to life. Accordingly, when homeostasis is disrupted by the excessive production of connective tissue, lung function deteriorates rapidly with grave consequences leading to chronic lung conditions such as pulmonary fibrosis. Understanding how pulmonary fibrosis develops and alters the link between lung structure and function is crucial for diagnosis, prognosis, and therapy. Further information gained could help elaborate how the healing process breaks down leading to chronic disease. Our understanding of fibrotic disease is greatly aided by the intersection of wet lab studies and mathematical and computational modeling. In the present review we will discuss how multi-scale modeling has facilitated our understanding of pulmonary fibrotic disease as well as identified opportunities that remain open and have produced techniques that can be incorporated into this field by borrowing approaches from multi-scale models of fibrosis beyond the lung.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.matbio.2020.04.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7434655PMC
September 2020

Epigenetic Regulation of TLR4 in Diabetic Macrophages Modulates Immunometabolism and Wound Repair.

J Immunol 2020 05 23;204(9):2503-2513. Epub 2020 Mar 23.

Section of Vascular Surgery, Department of Surgery, University of Michigan, Ann Arbor, MI 48109;

Macrophages are critical for the initiation and resolution of the inflammatory phase of wound healing. In diabetes, macrophages display a prolonged inflammatory phenotype preventing tissue repair. TLRs, particularly TLR4, have been shown to regulate myeloid-mediated inflammation in wounds. We examined macrophages isolated from wounds of patients afflicted with diabetes and healthy controls as well as a murine diabetic model demonstrating dynamic expression of TLR4 results in altered metabolic pathways in diabetic macrophages. Further, using a myeloid-specific mixed-lineage leukemia 1 (MLL1) knockout ( ), we determined that MLL1 drives expression in diabetic macrophages by regulating levels of histone H3 lysine 4 trimethylation on the promoter. Mechanistically, MLL1-mediated epigenetic alterations influence diabetic macrophage responsiveness to TLR4 stimulation and inhibit tissue repair. Pharmacological inhibition of the TLR4 pathway using a small molecule inhibitor (TAK-242) as well as genetic depletion of either ( ) or myeloid-specific resulted in improved diabetic wound healing. These results define an important role for MLL1-mediated epigenetic regulation of TLR4 in pathologic diabetic wound repair and suggest a target for therapeutic manipulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.1901263DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7443363PMC
May 2020

TNF-α regulates diabetic macrophage function through the histone acetyltransferase MOF.

JCI Insight 2020 03 12;5(5). Epub 2020 Mar 12.

Department of Surgery.

A critical component of wound healing is the transition from the inflammatory phase to the proliferation phase to initiate healing and remodeling of the wound. Macrophages are critical for the initiation and resolution of the inflammatory phase during wound repair. In diabetes, macrophages display a sustained inflammatory phenotype in late wound healing characterized by elevated production of inflammatory cytokines, such as TNF-α. Previous studies have shown that an altered epigenetic program directs diabetic macrophages toward a proinflammatory phenotype, contributing to a sustained inflammatory phase. Males absent on the first (MOF) is a histone acetyltransferase (HAT) that has been shown be a coactivator of TNF-α signaling and promote NF-κB-mediated gene transcription in prostate cancer cell lines. Based on MOF's role in TNF-α/NF-κB-mediated gene expression, we hypothesized that MOF influences macrophage-mediated inflammation during wound repair. We used myeloid-specific Mof-knockout (Lyz2Cre Moffl/fl) and diet-induced obese (DIO) mice to determine the function of MOF in diabetic wound healing. MOF-deficient mice exhibited reduced inflammatory cytokine gene expression. Furthermore, we found that wound macrophages from DIO mice had elevated MOF levels and higher levels of acetylated histone H4K16, MOF's primary substrate of HAT activity, on the promoters of inflammatory genes. We further identified that MOF expression could be stimulated by TNF-α and that treatment with etanercept, an FDA-approved TNF-α inhibitor, reduced MOF levels and improved wound healing in DIO mice. This report is the first to our knowledge to define an important role for MOF in regulating macrophage-mediated inflammation in wound repair and identifies TNF-α inhibition as a potential therapy for the treatment of chronic inflammation in diabetic wounds.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/jci.insight.132306DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7141388PMC
March 2020

TLR3 absence confers increased survival with improved macrophage activity against pneumonia.

JCI Insight 2019 12 5;4(23). Epub 2019 Dec 5.

Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA.

Toll-like receptor 3 (TLR3) is a pathogen recognition molecule associated with viral infection with double-stranded RNA (dsRNA) as its ligand. We evaluated the role of TLR3 in bacterial pneumonia using Klebsiella pneumoniae (KP). WT and TLR3-/- mice were subjected to a lethal model of KP. Alveolar macrophage polarization, bactericidal activity, and phagocytic capacity were compared. RNA-sequencing was performed on alveolar macrophages from the WT and TLR3-/- mice. Adoptive transfers of alveolar macrophages from TLR3-/- mice to WT mice with KP were evaluated for survival. Expression of TLR3 in postmortem human lung samples from patients who died from gram-negative pneumonia and pathological grading of pneumonitis was determined. Mortality was significantly lower in TLR3-/-, and survival improved in WT mice following antibody neutralization of TLR3 and with TLR3/dsRNA complex inhibitor. Alveolar macrophages from TLR3-/- mice demonstrated increased bactericidal and phagocytic capacity. RNA-sequencing showed an increased production of chemokines in TLR3-/- mice. Adoptive transfer of alveolar macrophages from the TLR3-/- mice restored the survival in WT mice. Human lung samples demonstrated a good correlation between the grade of pneumonitis and TLR3 expression. These data represent a paradigm shift in understanding the mechanistic role of TLR3 in bacterial pneumonia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/jci.insight.131195DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6962028PMC
December 2019

Inhibition of the stem cell factor 248 isoform attenuates the development of pulmonary remodeling disease.

Am J Physiol Lung Cell Mol Physiol 2020 01 20;318(1):L200-L211. Epub 2019 Nov 20.

Department of Pathology, University of Michigan, Ann Arbor, Michigan.

Stem cell factor (SCF) and its receptor c-kit have been implicated in inflammation, tissue remodeling, and fibrosis. Ingenuity Integrated Pathway Analysis of gene expression array data sets showed an upregulation of SCF transcripts in idiopathic pulmonary fibrosis (IPF) lung biopsies compared with tissue from nonfibrotic lungs that are further increased in rapid progressive disease. SCF248, a cleavable isoform of SCF, was abundantly and preferentially expressed in human lung fibroblasts and fibrotic mouse lungs relative to the SCF220 isoform. In fibroblast-mast cell coculture studies, blockade of SCF248 using a novel isoform-specific anti-SCF248 monoclonal antibody (anti-SCF248), attenuated the expression of , and transcripts in cocultured IPF but not normal lung fibroblasts. Administration of anti-SCF248 on days 8 and 12 after bleomycin instillation in mice significantly reduced fibrotic lung remodeling and , , and transcript expression. In addition, bleomycin increased numbers of c-kit+ mast cells, eosinophils, and ILC2 in lungs of mice, whereas they were not significantly increased in anti-SCF248-treated animals. Finally, mesenchymal cell-specific deletion of SCF significantly attenuated bleomycin-mediated lung fibrosis and associated fibrotic gene expression. Collectively, these data demonstrate that SCF is upregulated in diseased IPF lungs and blocking SCF248 isoform significantly ameliorates fibrotic lung remodeling in vivo suggesting that it may be a therapeutic target for fibrotic lung diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/ajplung.00114.2019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985874PMC
January 2020

Methods in Lung Microbiome Research.

Am J Respir Cell Mol Biol 2020 03;62(3):283-299

National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina.

The lung microbiome is associated with host immune response and health outcomes in experimental models and patient cohorts. Lung microbiome research is increasing in volume and scope; however, there are no established guidelines for study design, conduct, and reporting of lung microbiome studies. Standardized approaches to yield reliable and reproducible data that can be synthesized across studies will ultimately improve the scientific rigor and impact of published work and greatly benefit microbiome research. In this review, we identify and address several key elements of microbiome research: conceptual modeling and hypothesis framing; study design; experimental methodology and pitfalls; data analysis; and reporting considerations. Finally, we explore possible future directions and research opportunities. Our goal is to aid investigators who are interested in this burgeoning research area and hopefully provide the foundation for formulating consensus approaches in lung microbiome research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1165/rcmb.2019-0273TRDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7055701PMC
March 2020

Sepsis Induces Prolonged Epigenetic Modifications in Bone Marrow and Peripheral Macrophages Impairing Inflammation and Wound Healing.

Arterioscler Thromb Vasc Biol 2019 11 5;39(11):2353-2366. Epub 2019 Sep 5.

From the Section of Vascular Surgery, Department of Surgery (F.M.D., A.D., A.D.J., A.S.K., A.T.O., W.J.M., K.A.G.), University of Michigan, Ann Arbor.

Objective: Sepsis represents an acute life-threatening disorder resulting from a dysregulated host response. For patients who survive sepsis, there remains long-term consequences, including impaired inflammation, as a result of profound immunosuppression. The mechanisms involved in this long-lasting deficient immune response are poorly defined. Approach and Results: Sepsis was induced using the murine model of cecal ligation and puncture. Following a full recovery period from sepsis physiology, mice were subjected to our wound healing model and wound macrophages (CD11b+, CD3-, CD19-, Ly6G-) were sorted. Post-sepsis mice demonstrated impaired wound healing and decreased reepithelization in comparison to controls. Further, post-sepsis bone marrow-derived macrophages and wound macrophages exhibited decreased expression of inflammatory cytokines vital for wound repair (IL [interleukin]-1β, IL-12, and IL-23). To evaluate if decreased inflammatory gene expression was secondary to epigenetic modification, we conducted chromatin immunoprecipitation on post-sepsis bone marrow-derived macrophages and wound macrophages. This demonstrated decreased expression of , an epigenetic enzyme, and impaired histone 3 lysine 4 trimethylation (activation mark) at NFκB (nuclear factor kappa-light-chain-enhancer of activated B cells)-binding sites on inflammatory gene promoters in bone marrow-derived macrophages and wound macrophages from postcecal ligation and puncture mice. Bone marrow transplantation studies demonstrated epigenetic modifications initiate in bone marrow progenitor/stem cells following sepsis resulting in lasting impairment in peripheral macrophage function. Importantly, human peripheral blood leukocytes from post-septic patients demonstrate a significant reduction in compared with nonseptic controls.

Conclusions: These data demonstrate that severe sepsis induces stable mixed-lineage leukemia 1-mediated epigenetic modifications in the bone marrow, which are passed to peripheral macrophages resulting in impaired macrophage function and deficient wound healing persisting long after sepsis recovery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1161/ATVBAHA.119.312754DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6818743PMC
November 2019

Design of biodegradable nanoparticles to modulate phenotypes of antigen-presenting cells for antigen-specific treatment of autoimmune disease.

Biomaterials 2019 11 17;222:119432. Epub 2019 Aug 17.

Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA; Department of Chemical Engineering, University of Michigan, Ann Arbor, MI, 48109, USA. Electronic address:

Current therapeutic options for autoimmune diseases, such as multiple sclerosis (MS), often require lifelong treatment with immunosuppressive drugs, yet strategies for antigen-specific immunomodulation are emerging. Biodegradable particles loaded with disease-specific antigen, either alone or with immunomodulators, have been reported to ameliorate disease. Herein, we hypothesized that the carrier could impact polarization of the immune cells that associate with particles and the subsequent disease progression. Single injection of three polymeric carriers, 50:50 poly (DL-lactide-co-glycolide) (PLG) with two molecular weights (Low, High) and poly (DL-lactide) (PLA), loaded with the disease-specific antigen, proteolipid protein (PLP), were investigated for the ability to attenuate clinical scores in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. At a low particle dose, mice treated with PLA-based particles had significantly lower clinical scores at the chronic stage of the disease over 200 days post immunization, while neither PLG-based particles nor OVA control particles reduced the clinical scores. Compared to PLG-based particles, PLA-based particles were largely associated with Kupffer cells and liver sinusoidal endothelial cells, which had a reduced co-stimulatory molecule expression that correlated with a reduction of CD4 T-cell populations in the central nervous system. Delivery of PLA-based particles encapsulated with higher levels of PLP at a reduced dose were able to completely ameliorate EAE over 200 days along with inhibition of Th1 and Th17 polarization. Collectively, our study demonstrates that the carrier properties and antigen loading determine phenotypes of immune cells in the peripheral organs, influencing the amelioration of both acute and chronic stages of autoimmunity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biomaterials.2019.119432DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6830542PMC
November 2019

Stem cell transplantation impairs dendritic cell trafficking and herpesvirus immunity.

JCI Insight 2019 09 19;4(18). Epub 2019 Sep 19.

Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA.

Long-term survivors after hematopoietic stem cell transplantation are at high risk of infection, which accounts for one-third of all deaths related to stem cell transplantation. Little is known about the cause of inferior host defense after immune cell reconstitution. Here, we exploited a murine syngeneic BM transplantation (BMT) model of late infection with murine gammaherpesvirus 68 (MHV-68) to determine the role of conventional DC (cDC) trafficking in adaptive immunity in BMT mice. After infection, the expression of chemokine Ccl21 in the lung is reduced and the migration of cDCs into lung draining lymph nodes (dLNs) is impaired in BMT mice, limiting the opportunity for cDCs to prime Th cells in the dLNs. While cDC subsets are redundant in priming Th1 cells, Notch2 functions in cDC2s are required for priming increased Th17 responses in BMT mice, and cDC1s can lessen this activity. Importantly, Th17 cells can be primed both in the lungs and dLNs, allowing for increased Th17 responses without optimum cDC trafficking in BMT mice. Taken together, impaired cDC trafficking in BMT mice reduces protective Th1 responses and allows increased pathogenic Th17 responses. Thus, we have revealed a previously unknown mechanism for BMT procedures to cause long-term inferior immune responses to herpes viral infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/jci.insight.130210DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6795288PMC
September 2019

The Histone Methyltransferase Setdb2 Modulates Macrophage Phenotype and Uric Acid Production in Diabetic Wound Repair.

Immunity 2019 08 23;51(2):258-271.e5. Epub 2019 Jul 23.

Department of Surgery, University of Michigan, Ann Arbor, MI, USA; Department of Microbiology and Immunology, University of Michigan, Ann Arbor, MI, USA. Electronic address:

Macrophage plasticity is critical for normal tissue repair to ensure transition from the inflammatory to the proliferative phase of healing. We examined macrophages isolated from wounds of patients afflicted with diabetes and of healthy controls and found differential expression of the methyltransferase Setdb2. Myeloid-specific deletion of Setdb2 impaired the transition of macrophages from an inflammatory phenotype to a reparative one in normal wound healing. Mechanistically, Setdb2 trimethylated histone 3 at NF-κB binding sites on inflammatory cytokine gene promoters to suppress transcription. Setdb2 expression in wound macrophages was regulated by interferon (IFN) β, and under diabetic conditions, this IFNβ-Setdb2 axis was impaired, leading to a persistent inflammatory macrophage phenotype in diabetic wounds. Setdb2 regulated the expression of xanthine oxidase and thereby the uric acid (UA) pathway of purine catabolism in macrophages, and pharmacologic targeting of Setdb2 or the UA pathway improved healing. Thus, Setdb2 regulates macrophage plasticity during normal and pathologic wound repair and is a target for therapeutic manipulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.immuni.2019.06.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6703945PMC
August 2019

A pathologic two-way street: how innate immunity impacts lung fibrosis and fibrosis impacts lung immunity.

Clin Transl Immunology 2019 26;8(6):e1065. Epub 2019 Jun 26.

Department of Microbiology and Immunology University of Michigan Ann Arbor MI USA.

Lung fibrosis is characterised by the accumulation of extracellular matrix within the lung and is secondary to both known and unknown aetiologies. This accumulation of scar tissue limits gas exchange causing respiratory insufficiency. The pathogenesis of lung fibrosis is poorly understood, but immunologic-based treatments have been largely ineffective. Despite this, accumulating evidence suggests that innate immune cells and receptors play important modulatory roles in the initiation and propagation of the disease. Paradoxically, while innate immune signalling may be important for the pathogenesis of fibrosis, there is also evidence to suggest that innate immune function against pathogens may be impaired, leading to dysregulated and/or impaired host defence. This review summarises the evidence for this pathologic two-way street, highlights new concepts of pathogenesis and recommends future directions for research emphasis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cti2.1065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6593479PMC
June 2019

Intravascular innate immune cells reprogrammed via intravenous nanoparticles to promote functional recovery after spinal cord injury.

Proc Natl Acad Sci U S A 2019 07 8;116(30):14947-14954. Epub 2019 Jul 8.

Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48105;

Traumatic primary spinal cord injury (SCI) results in paralysis below the level of injury and is associated with infiltration of hematogenous innate immune cells into the injured cord. Methylprednisolone has been applied to reduce inflammation following SCI, yet was discontinued due to an unfavorable risk-benefit ratio associated with off-target effects. In this study, i.v. administered poly(lactide-coglycolide) nanoparticles were internalized by circulating monocytes and neutrophils, reprogramming these cells based on their physicochemical properties and not by an active pharmaceutical ingredient, to exhibit altered biodistribution, gene expression, and function. Approximately 80% of nanoparticle-positive immune cells were observed within the injury, and, additionally, the overall accumulation of innate immune cells at the injury was reduced 4-fold, coinciding with down-regulated expression of proinflammatory factors and increased expression of antiinflammatory and proregenerative genes. Furthermore, nanoparticle administration induced macrophage polarization toward proregenerative phenotypes at the injury and markedly reduced both fibrotic and gliotic scarring 3-fold. Moreover, nanoparticle administration with the implanted multichannel bridge led to increased numbers of regenerating axons, increased myelination with about 40% of axons myelinated, and an enhanced locomotor function (score of 6 versus 3 for control group). These data demonstrate that nanoparticles provide a platform that limits acute inflammation and tissue destruction, at a favorable risk-benefit ratio, leading to a proregenerative microenvironment that supports regeneration and functional recovery. These particles may have applications to trauma and potentially other inflammatory diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.1820276116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6660718PMC
July 2019

SIRT3 Regulates Macrophage-Mediated Inflammation in Diabetic Wound Repair.

J Invest Dermatol 2019 12 15;139(12):2528-2537.e2. Epub 2019 Jun 15.

Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA; Department of Microbiology and Immunology, University of Michigan, Ann Arbor, Michigan, USA. Electronic address:

Control of inflammation is critical for the treatment of nonhealing wounds, but a delicate balance exists between early inflammation that is essential for normal tissue repair and the pathologic inflammation that can occur later in the repair process. This necessitates the development of novel therapies that can target inflammation at the appropriate time during repair. Here, we found that SIRT3 is essential for normal healing and regulates inflammation in wound macrophages after injury. Under prediabetic conditions, SIRT3 was decreased in wound macrophages and resulted in dysregulated inflammation. In addition, we found that FABP4 regulates SIRT3 in human blood monocytes, and inhibition of FABP4 in wound macrophages decreases inflammatory cytokine expression, making FABP4 a viable target for the regulation of excess inflammation and wound repair in diabetes. Using a series of ex vivo and in vivo studies with genetically engineered mouse models and diabetic human monocytes, we showed that FABP4 expression is epigenetically upregulated in diabetic wound macrophages and, in turn, diminishes SIRT3 expression, thereby promoting inflammation. These findings have significant implications for controlling inflammation and promoting tissue repair in diabetic wounds.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jid.2019.05.017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7185380PMC
December 2019

Ironing Out the Roles of Macrophages in Idiopathic Pulmonary Fibrosis.

Am J Respir Crit Care Med 2019 Jul;200(2):127-129

2 Division of Pulmonary and Critical Care Medicine and.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1164/rccm.201904-0891EDDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6635782PMC
July 2019