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2.
Ann Am Thorac Soc ; 20(8): 1077-1087, 2023 08.
Article in English | MEDLINE | ID: mdl-37526479

ABSTRACT

Rationale: To identify barriers and opportunities for Ph.D., basic and translational scientists to be fully integrated into clinical units. Objectives: In 2022, an ad hoc committee of the American Thoracic Society developed a project proposal and workshop to identify opportunities and barriers for scientists who do not practice medicine to develop successful careers and achieve tenure-track faculty positions in clinical departments and divisions within academic medical centers (AMCs) in the United States. Methods: This document focuses on results from a survey of adult and pediatric pulmonary, critical care, and sleep medicine division chiefs as well as a survey of workshop participants, including faculty in departmental and school leadership roles in both basic science and clinical units within U.S. AMCs. Results: We conclude that full integration of non-clinically practicing basic and translational scientists into the clinical units, in addition to their traditional placements in basic science units, best serves the tripartite mission of AMCs to provide care, perform research, and educate the next generation. Evidence suggests clinical units do employ Ph.D. scientists in large numbers, but these faculty are often hired into non-tenure track positions, which do not provide the salary support, start-up funds, research independence, or space often associated with hiring in basic science units within the same institution. These barriers to success of Ph.D. faculty in clinical units are largely financial. Conclusions: Our recommendation is for AMCs to consider and explore some of our proposed strategies to accomplish the goal of integrating basic and translational scientists into clinical units in a meaningful way.


Subject(s)
Academic Medical Centers , Physicians , Adult , United States , Humans , Child , Personnel Selection , Leadership , Faculty, Medical
3.
Respirology ; 28(12): 1147-1153, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37646126

ABSTRACT

BACKGROUND AND OBJECTIVE: Surrogate endpoints enable determination of meaningful treatment effects more efficiently than applying the endpoint of ultimate interest. We used data from trials of nintedanib in subjects with pulmonary fibrosis to assess decline in forced vital capacity (FVC) as a surrogate for mortality. METHODS: Data from the nintedanib and placebo groups of trials in subjects with idiopathic pulmonary fibrosis, other forms of progressive pulmonary fibrosis, and pulmonary fibrosis due to systemic sclerosis (NCT00514683, NCT01335464, NCT01335477, NCT01979952, NCT02999178, NCT02597933) were pooled. Using joint models for longitudinal and time-to-event data, we assessed the association between decline in FVC % predicted and time to death over 52 weeks. The rate of change in FVC % predicted and the current value of FVC % predicted were modelled longitudinally and estimates applied as predictors in time-to-event models. RESULTS: Among 2583 subjects with pulmonary fibrosis, both a greater rate of decline in FVC % predicted and a lower current value of FVC % predicted were associated with an increased risk of death over 52 weeks (HR 1.79 [95% CI: 1.57, 2.03] and HR 1.24 [1.17, 1.32] per 5-percentage point decrease, respectively). Associations between the rate of change in FVC % predicted and the risk of death were consistent between patients with IPF and other ILDs. CONCLUSION: Data from clinical trials in subjects with pulmonary fibrosis of diverse aetiology demonstrate a strong association between decline in FVC % predicted and mortality over 52 weeks, supporting FVC decline as a surrogate for mortality in these patients.


Subject(s)
Idiopathic Pulmonary Fibrosis , Humans , Treatment Outcome , Vital Capacity , Idiopathic Pulmonary Fibrosis/drug therapy , Biomarkers , Disease Progression
4.
Am J Pathol ; 193(9): 1130-1142, 2023 09.
Article in English | MEDLINE | ID: mdl-37263344

ABSTRACT

Orchestration of inflammation and tissue repair processes is critical to maintaining homeostasis upon tissue injury. Tissue fibrosis is a pathological process characterized by aberrant accumulation of extracellular matrix proteins, such as collagen, upon injury. Dickkopf1 (DKK1) is a quintessential Wnt antagonist. The role of DKK1 in bleomycin (BLM)-induced lung injury and fibrosis model remains elusive. This study shows that BLM-induced lung injury markedly elevated DKK1 protein expressions in the lungs in mice, consistent with human pulmonary fibrosis patient lung tissues. The elevated DKK1 levels coincided with immune cell infiltration and collagen deposition. Notably, the reduced expression of DKK1 in Dkk1 hypomorphic doubleridge (Dkk1d/d) mice abrogated BLM-induced lung inflammation and fibrosis. Immune cell infiltration, collagen deposition, expression of profibrotic cytokine transforming growth factor ß1 (TGF-ß1), and extracellular matrix protein-producing myofibroblast marker α-smooth muscle actin (α-SMA) were reduced in Dkk1d/d mice. Consistent with these results, local DKK1 antibody administration after BLM-induced lung injury substantially decreased lung inflammation and fibrosis phenotypes. Taken together, these results demonstrate that DKK1 is a proinflammatory and profibrotic ligand that promotes inflammation and fibrosis upon BLM-induced lung injury, placing it as an attractive molecular target for dysregulated pulmonary inflammation and tissue repair.


Subject(s)
Lung Injury , Pneumonia , Pulmonary Fibrosis , Humans , Mice , Animals , Pulmonary Fibrosis/pathology , Bleomycin/toxicity , Lung Injury/pathology , Lung/pathology , Transforming Growth Factor beta1/metabolism , Collagen/metabolism , Pneumonia/metabolism , Inflammation/pathology
5.
Pharmacol Ther ; 247: 108460, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37244406

ABSTRACT

Pulmonary fibrotic diseases are characterized by proliferation of lung fibroblasts and myofibroblasts and excessive deposition of extracellular matrix proteins. Depending on the specific form of lung fibrosis, there can be progressive scarring of the lung, leading in some cases to respiratory failure and/or death. Recent and ongoing research has demonstrated that resolution of inflammation is an active process regulated by families of small bioactive lipid mediators termed "specialized pro-resolving mediators." While there are many reports of beneficial effects of SPMs in animal and cell culture models of acute and chronic inflammatory and immune diseases, there have been fewer reports investigating SPMs and fibrosis, especially pulmonary fibrosis. Here, we will review evidence that resolution pathways are impaired in interstitial lung disease, and that SPMs and other similar bioactive lipid mediators can inhibit fibroblast proliferation, myofibroblast differentiation, and accumulation of excess extracellular matrix in cell culture and animal models of pulmonary fibrosis, and we will consider future therapeutic implications of SPMs in fibrosis.


Subject(s)
Pulmonary Fibrosis , Animals , Pulmonary Fibrosis/drug therapy , Pulmonary Fibrosis/metabolism , Pulmonary Fibrosis/pathology , Lung/metabolism , Fibrosis , Cell Differentiation , Inflammation/drug therapy , Lipids , Inflammation Mediators/metabolism
6.
Am J Physiol Lung Cell Mol Physiol ; 324(6): L863-L869, 2023 06 01.
Article in English | MEDLINE | ID: mdl-37039378

ABSTRACT

Radiation-induced lung injury (RILI) is a consequence of therapeutic thoracic irradiation (TR) for many cancers, and there are no FDA-approved curative strategies. Studies report that 80% of patients who undergo TR will have CT-detectable interstitial lung abnormalities, and strategies to limit the risk of RILI may make radiotherapy less effective at treating cancer. Our lab and others have reported that lung tissue from patients with idiopathic pulmonary fibrosis (IPF) exhibits metabolic defects including increased glycolysis and lactate production. In this pilot study, we hypothesized that patients with radiation-induced lung damage will exhibit distinct changes in lung metabolism that may be associated with the incidence of fibrosis. Using liquid chromatography/tandem mass spectrometry to identify metabolic compounds, we analyzed exhaled breath condensate (EBC) in subjects with CT-confirmed lung lesions after TR for lung cancer, compared with healthy subjects, smokers, and cancer patients who had not yet received TR. The lung metabolomic profile of the irradiated group was significantly different from the three nonirradiated control groups, highlighted by increased levels of lactate. Pathway enrichment analysis revealed that EBC from the case patients exhibited concurrent alterations in lipid, amino acid, and carbohydrate energy metabolism associated with the energy-producing tricarboxylic acid (TCA) cycle. Radiation-induced glycolysis and diversion of lactate to the extracellular space suggests that pyruvate, a precursor metabolite, converts to lactate rather than acetyl-CoA, which contributes to the TCA cycle. This TCA cycle deficiency may be compensated by these alternate energy sources to meet the metabolic demands of chronic wound repair. Using an "omics" approach to probe lung disease in a noninvasive manner could inform future mechanistic investigations and the development of novel therapeutic targets.NEW & NOTEWORTHY We report that exhaled breath condensate (EBC) identifies cellular metabolic dysregulation in patients with radiation-induced lung injury. In this pilot study, untargeted metabolomics revealed a striking metabolic signature in EBC from patients with radiation-induced lung fibrosis compared to patients with lung cancer, at-risk smokers, and healthy volunteers. Patients with radiation-induced fibrosis exhibit specific changes in tricarboxylic acid (TCA) cycle energy metabolism that may be required to support the increased energy demands of fibroproliferation.


Subject(s)
Idiopathic Pulmonary Fibrosis , Lung Injury , Lung Neoplasms , Humans , Pilot Projects , Idiopathic Pulmonary Fibrosis/etiology , Idiopathic Pulmonary Fibrosis/metabolism , Lactic Acid/analysis , Lung Neoplasms/radiotherapy , Breath Tests/methods , Lung/metabolism , Biomarkers/analysis
7.
Front Immunol ; 14: 1247330, 2023.
Article in English | MEDLINE | ID: mdl-38162655

ABSTRACT

Immune responses are crucial to maintaining tissue homeostasis upon tissue injury. Upon various types of challenges, macrophages play a central role in regulating inflammation and tissue repair processes. While an immunomodulatory role of Wnt antagonist Dickkopf1 (DKK1) has been implicated, the role of Wnt antagonist DKK1 in regulating macrophage polarization in inflammation and the tissue repair process remains elusive. Here we found that DKK1 induces gene expression profiles to promote inflammation and tissue repair in macrophages. Importantly, DKK1 induced various genes, including inflammation and tissue repair, via JNK (c-jun N-terminal kinase) in macrophages. Furthermore, DKK1 potentiated IL-13-mediated macrophage polarization and activation. The co-inhibition of JNK and STAT6 markedly decreased gene expressions relevant to inflammation and fibrosis by DKK1 and IL-13. Interestingly, thrombocyte-specific deletion of DKK1 in mice reduced collagen deposition and decreased Arg1, CD206, HIF1α, and IL1ß protein expressions in monocyte-derived alveolar macrophages in the acute sterile bleomycin (BLM)-induced lung injury model. These data suggested that thrombocytes communicate with macrophages via DKK1 to orchestrate inflammation and repair in this model. Taken together, our study demonstrates DKK1's role as an important regulatory ligand for macrophage polarization in the injury-induced inflammation and repair process in the lung.


Subject(s)
Acute Lung Injury , Blood Platelets , Macrophages , Animals , Mice , Acute Lung Injury/metabolism , Bleomycin/adverse effects , Blood Platelets/metabolism , Inflammation , Interleukin-13/metabolism
8.
Int J Mol Sci ; 23(19)2022 Oct 08.
Article in English | MEDLINE | ID: mdl-36233248

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic, interstitial lung disease with a poor prognosis. Although specific anti-fibrotic medications are now available, the median survival time following diagnosis remains very low, and new therapies are urgently needed. To uncover novel therapeutic targets, we examined how biochemical properties of the fibrotic lung are different from the healthy lung. Previous work identified lactate as a metabolite that is upregulated in IPF lung tissue. Importantly, inhibition of the enzyme responsible for lactate production prevents fibrosis in vivo. Further studies revealed that fibrotic lesions of the lung experience a significant decline in tissue pH, likely due to the overproduction of lactate. It is not entirely clear how cells in the lung respond to changes in extracellular pH, but a family of proton sensing G-protein coupled receptors has been shown to be activated by reductions in extracellular pH. This work examines the expression profiles of proton sensing GPCRs in non-fibrotic and IPF-derived primary human lung fibroblasts. We identify TDAG8 as a proton sensing GPCR that is upregulated in IPF fibroblasts and that knockdown of TDAG8 dampens myofibroblast differentiation. To our surprise, BTB, a proposed positive allosteric modulator of TDAG8, inhibits myofibroblast differentiation. Our data suggest that BTB does not require TDAG8 to inhibit myofibroblast differentiation, but rather inhibits myofibroblast differentiation through suppression of RhoA mediated signaling. Our work highlights the therapeutic potential of BTB as an anti-fibrotic treatment and expands upon the importance of RhoA-mediated signaling pathways in the context of myofibroblast differentiation. Furthermore, this works also suggests that TDAG8 inhibition may have therapeutic relevance in the treatment of IPF.


Subject(s)
Idiopathic Pulmonary Fibrosis , rhoA GTP-Binding Protein , Cell Differentiation/physiology , Fibroblasts/metabolism , Fibrosis , Humans , Idiopathic Pulmonary Fibrosis/metabolism , Lactates/metabolism , Lung/pathology , Myofibroblasts/metabolism , Protons , rhoA GTP-Binding Protein/metabolism
9.
Cells ; 11(16)2022 08 16.
Article in English | MEDLINE | ID: mdl-36010617

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a disease characterized by irreversible lung scarring. The pathophysiology is not fully understood, but the working hypothesis postulates that a combination of epithelial injury and myofibroblast differentiation drives progressive pulmonary fibrosis. We previously demonstrated that a reduction in extracellular pH activates latent TGF-ß1, and that TGF-ß1 then drives its own activation, creating a feed-forward mechanism that propagates myofibroblast differentiation. Given the important roles of extracellular pH in the progression of pulmonary fibrosis, we sought to identify whether pH mediates other cellular phenotypes independent of TGF-ß1. Proton-sensing G-protein coupled receptors are activated by acidic environments, but their role in fibrosis has not been studied. Here, we report that the Ovarian Cancer G-Protein Coupled Receptor1 (OGR1 or GPR68) has dual roles in both promoting and mitigating pulmonary fibrosis. We demonstrate that OGR1 protein expression is significantly reduced in lung tissue from patients with IPF and that TGF-ß1 decreases OGR1 expression. In fibroblasts, OGR1 inhibits myofibroblast differentiation and does not contribute to inflammation. However, in epithelial cells, OGR1 promotes epithelial to mesenchymal transition (EMT) and inflammation. We then demonstrate that sub-cellular localization and alternative signaling pathways may be responsible for the differential effect of OGR1 in each cell type. Our results suggest that strategies to selectively target OGR1 expression may represent a novel therapeutic strategy for pulmonary fibrosis.


Subject(s)
Idiopathic Pulmonary Fibrosis , Ovarian Neoplasms , Carcinoma, Ovarian Epithelial , Epithelial-Mesenchymal Transition , Female , Fibrosis , Humans , Idiopathic Pulmonary Fibrosis/metabolism , Inflammation , Receptors, G-Protein-Coupled/metabolism , Transforming Growth Factor beta1/pharmacology
10.
Acad Med ; 97(11): 1583-1586, 2022 11 01.
Article in English | MEDLINE | ID: mdl-36044276

ABSTRACT

As the landscape of philanthropy changes following the COVID-19 pandemic, this commentary considers the future of endowed chairs in academic medicine in the light of articles by Thorndyke and colleagues and by Chin-Hong and colleagues in this issue. The authors evaluate the traditional allocation of endowed chairs, which can attract and retain talented faculty and can support focused research far into the future, while other gifts may support more timely concerns, but over a shorter term. The authors weigh the benefits and challenges of allocation of endowed chairs, such as the need to improve representation, diversity, equity, and inclusion, and opportunities to support early-career investigators or research teams. New endowed positions can be challenging to establish, as there may be competition with learner scholarship programs and programmatic support. Leadership turnover of university presidents and deans can slow philanthropic growth and make recruitment and fundraising for new positions even more challenging. The authors discuss the balance of institutional priorities and ways to use endowed chairs for scholarship in evolving areas of medicine and science. They further suggest working with donors to develop more adaptable gift agreements, which will allow institutions to transform endowed positions to meet changing needs while preserving the intentions of the donor. To maintain endowed chairs as a worthwhile and relevant outlet for philanthropy, one which donors will enthusiastically support, it is essential to align them with the changing needs of the institution and the broader environment of academic medicine.


Subject(s)
COVID-19 , Emergency Medicine , Humans , Faculty, Medical , Academic Medical Centers , Pandemics , COVID-19/epidemiology , Leadership
11.
Toxicol Appl Pharmacol ; 450: 116160, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35817128

ABSTRACT

Epidemiological studies associate biomass smoke with an increased risk for respiratory infections in children and adults in the developing world, with 500,000 premature deaths each year attributed to biomass smoke-related acute respiratory infections including infections caused by respiratory viruses. Animal dung is a biomass fuel of particular concern because it generates more toxic compounds per amount burned than wood, and is a fuel of last resort for the poorest households. Currently, there is little biological evidence on the effects of dung biomass smoke exposure on immune responses to respiratory viral infections. Here, we investigated the impact of dung biomass exposure on respiratory infection using a mouse model of dung biomass smoke and cultured primary human small airway epithelial cells (SAECs). Mice infected with influenza A virus (IAV) after dung biomass smoke exposure had increased mortality, lung inflammation and virus mRNA levels, and suppressed expression of innate anti-viral mediators compared to air exposed mice. Importantly, there was still significant tissue inflammation 14 days after infection in dung biomass smoke-exposed mice even after inflammation had resolved in air-exposed mice. Dung biomass smoke exposure also suppressed the production of anti-viral cytokines and interferons in cultured SAECs treated with poly(I:C) or IAV. This study shows that dung biomass smoke exposure impairs the immune response to respiratory viruses and contributes to biomass smoke-related susceptibility to respiratory viral infections, likely due to a failure to resolve the inflammatory effects of biomass smoke exposure.


Subject(s)
Influenza, Human , Pneumonia , Respiratory Tract Infections , Animals , Biomass , Child , Humans , Inflammation/chemically induced , Inflammation/metabolism
12.
Semin Immunol ; 59: 101605, 2022 01.
Article in English | MEDLINE | ID: mdl-35660338

ABSTRACT

Specialized pro-resolving mediators (SPMs) are endogenous small molecules produced mainly from dietary omega-3 polyunsaturated fatty acids by both structural cells and cells of the active and innate immune systems. Specialized pro-resolving mediators have been shown to both limit acute inflammation and promote resolution and return to homeostasis following infection or injury. There is growing evidence that chronic immune disorders are characterized by deficiencies in resolution and SPMs have significant potential as novel therapeutics to prevent and treat chronic inflammation and immune system disorders. This review focuses on important breakthroughs in understanding how SPMs are produced by, and act on, cells of the adaptive immune system, specifically macrophages, B cells and T cells. We also highlight recent evidence demonstrating the potential of SPMs as novel therapeutic agents in topics including immunization, autoimmune disease and transplantation.


Subject(s)
Docosahexaenoic Acids , Fatty Acids, Omega-3 , Humans , Docosahexaenoic Acids/therapeutic use , Fatty Acids, Omega-3/therapeutic use , Inflammation/drug therapy , Inflammation Mediators/therapeutic use , Immunity
13.
Am J Physiol Lung Cell Mol Physiol ; 322(3): L385-L400, 2022 03 01.
Article in English | MEDLINE | ID: mdl-34986654

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic interstitial lung disease. The pathogenesis of IPF is not completely understood. However, numerous genes are associated with the development and progression of pulmonary fibrosis, indicating there is a significant genetic component to the pathogenesis of IPF. Epigenetic influences on the development of human disease, including pulmonary fibrosis, remain to be fully elucidated. In this paper, we identify miR-338-3p as a microRNA severely downregulated in the lungs of patients with pulmonary fibrosis and in experimental models of pulmonary fibrosis. Treatment of primary human lung fibroblasts with miR-338-3p inhibits myofibroblast differentiation and matrix protein production. Published and proposed targets of miR-338-3p such as TGFß receptor 1, MEK/ERK 1/2, Cdk4, and Cyclin D are also not responsible for the regulation of pulmonary fibroblast behavior by miR-338-3p. miR-338-3p inhibits myofibroblast differentiation by preventing TGFß-mediated downregulation of phosphatase and tensin homolog (PTEN), a known antifibrotic mediator.


Subject(s)
Idiopathic Pulmonary Fibrosis , MicroRNAs , Fibroblasts/metabolism , Humans , Idiopathic Pulmonary Fibrosis/pathology , Lung/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Myofibroblasts/metabolism , PTEN Phosphohydrolase/genetics , PTEN Phosphohydrolase/metabolism , Transforming Growth Factor beta/metabolism
14.
Development ; 149(1)2022 01 01.
Article in English | MEDLINE | ID: mdl-34931663

ABSTRACT

Alveologenesis requires the coordinated modulation of the epithelial and mesenchymal compartments to generate mature alveolar saccules for efficient gas exchange. However, the molecular mechanisms underlying the epithelial-mesenchymal interaction during alveologenesis are poorly understood. Here, we report that Wnts produced by epithelial cells are crucial for neonatal alveologenesis. Deletion of the Wnt chaperone protein Wntless homolog (Wls) disrupts alveolar formation, resulting in enlarged saccules in Sftpc-Cre/Nkx2.1-Cre; Wlsloxp/loxp mutants. Although commitment of the alveolar epithelium is unaffected, α-SMA+ mesenchymal cells persist in the alveoli, accompanied by increased collagen deposition, and mutants exhibit exacerbated fibrosis following bleomycin challenge. Notably, α-SMA+ cells include a significant number of endothelial cells resembling endothelial to mesenchymal transition (EndMT), which is also present in Ager-CreER; Wlsloxp/loxp mutants following early postnatal Wls deletion. These findings provide initial evidence that epithelial-derived Wnts are crucial for the differentiation of the surrounding mesenchyme during early postnatal alveologenesis.


Subject(s)
Alveolar Epithelial Cells/metabolism , Receptors, G-Protein-Coupled/metabolism , Actins/genetics , Actins/metabolism , Alveolar Epithelial Cells/cytology , Animals , Cells, Cultured , Epithelial-Mesenchymal Transition , Mice , Mice, Inbred C57BL , Receptors, G-Protein-Coupled/genetics
15.
J Clin Transl Sci ; 5(1): e80, 2021 Jan 25.
Article in English | MEDLINE | ID: mdl-34192047

ABSTRACT

The rate at which the coronavirus disease (COVID-19) spread required a rapid response across many, if not all, industries. Academic medical centers had to rapidly evaluate, prioritize, and coordinate the multiple requests for clinical trial participation. This involved redirecting resources and developing a collaborative system for assessment, decision making, and implementation. Our institution formed a team with diverse representation from multiple stakeholders to review and prioritize all research protocols related to COVID-19. To accomplish this, a prioritization matrix was developed to help determine the order in which the protocols should be placed for consideration by the treating clinician. The purpose of the team was to review the COVID-19 clinical trials in the pipeline, prioritize those trials that best met the needs of our patients, oversee training and resource needs, and lead the formulation of procedures for integration with clinical care. Resources from the Clinical Research Unit were then allocated to support the swift execution of such studies. This manuscript describes that process, the challenges encountered, and the lessons learned on how to make all clinical trials more successful in a complex and dynamic environment.

16.
FASEB J ; 35(3): e21376, 2021 03.
Article in English | MEDLINE | ID: mdl-33605487

ABSTRACT

Emphysema, a component of chronic obstructive pulmonary disease (COPD), is characterized by irreversible alveolar destruction that results in a progressive decline in lung function. This alveolar destruction is caused by cigarette smoke, the most important risk factor for COPD. Only 15%-20% of smokers develop COPD, suggesting that unknown factors contribute to disease pathogenesis. We postulate that the aryl hydrocarbon receptor (AHR), a receptor/transcription factor highly expressed in the lungs, may be a new susceptibility factor whose expression protects against COPD. Here, we report that Ahr-deficient mice chronically exposed to cigarette smoke develop airspace enlargement concomitant with a decline in lung function. Chronic cigarette smoke exposure also increased cleaved caspase-3, lowered SOD2 expression, and altered MMP9 and TIMP-1 levels in Ahr-deficient mice. We also show that people with COPD have reduced expression of pulmonary and systemic AHR, with systemic AHR mRNA levels positively correlating with lung function. Systemic AHR was also lower in never-smokers with COPD. Thus, AHR expression protects against the development of COPD by controlling interrelated mechanisms involved in the pathogenesis of this disease. This study identifies the AHR as a new, central player in the homeostatic maintenance of lung health, providing a foundation for the AHR as a novel therapeutic target and/or predictive biomarker in chronic lung disease.


Subject(s)
Pulmonary Disease, Chronic Obstructive/etiology , Receptors, Aryl Hydrocarbon/deficiency , Aged , Aged, 80 and over , Animals , Aryl Hydrocarbon Receptor Nuclear Translocator/physiology , Emphysema/etiology , Forced Expiratory Volume , Humans , Lung/physiopathology , Male , Mice , Middle Aged , Pulmonary Disease, Chronic Obstructive/physiopathology , Receptors, Aryl Hydrocarbon/genetics , Receptors, Aryl Hydrocarbon/physiology , Smoking/adverse effects
18.
J Immunol ; 206(6): 1348-1360, 2021 03 15.
Article in English | MEDLINE | ID: mdl-33558371

ABSTRACT

Cigarette smoke is a potent proinflammatory trigger contributing to acute lung injury and the development of chronic lung diseases via mechanisms that include the impairment of inflammation resolution. We have previously demonstrated that secondhand smoke (SHS) exposure exacerbates bacterial infection-induced pulmonary inflammation and suppresses immune responses. It is now recognized that resolution of inflammation is a bioactive process mediated by lipid-derived specialized proresolving mediators that counterregulate proinflammatory signaling and promote resolution pathways. We therefore hypothesized that proresolving mediators could reduce the burden of inflammation due to chronic lung infection following SHS exposure and restore normal immune responses to respiratory pathogens. To address this question, we exposed mice to SHS followed by chronic infection with nontypeable Haemophilus influenzae (NTHI). Some groups of mice were treated with aspirin-triggered resolvin D1 (AT-RvD1) during the latter half of the smoke exposure period or during a period of smoking cessation and before infection. Treatment with AT-RvD1 markedly reduced the recruitment of neutrophils, macrophages, and T cells in lung tissue and bronchoalveolar lavage and levels of proinflammatory cytokines in the bronchoalveolar lavage. Additionally, treatment with AT-RvD1 improved Ab titers against the NTHI outer membrane lipoprotein Ag P6 following infection. Furthermore, treatment with AT-RvD1 prior to classically adjuvanted immunization with P6 increased Ag-specific Ab titers, resulting in rapid clearance of NTHI from the lungs after acute challenge. Collectively, we have demonstrated that AT-RvD1 potently reverses the detrimental effects of SHS on pulmonary inflammation and immunity and thus could be beneficial in reducing lung injury associated with smoke exposure and infection.


Subject(s)
Docosahexaenoic Acids/pharmacology , Haemophilus Infections/drug therapy , Pneumonia/drug therapy , Tobacco Smoke Pollution/adverse effects , Animals , Antibodies, Bacterial/blood , Antibodies, Bacterial/immunology , Disease Models, Animal , Docosahexaenoic Acids/therapeutic use , Female , Haemophilus Infections/blood , Haemophilus Infections/immunology , Haemophilus Infections/microbiology , Haemophilus influenzae/immunology , Humans , Lung/drug effects , Lung/immunology , Lung/microbiology , Mice , Pneumonia/blood , Pneumonia/immunology , Pneumonia/microbiology
19.
Am J Pathol ; 191(1): 18-25, 2021 01.
Article in English | MEDLINE | ID: mdl-33031756

ABSTRACT

Idiopathic pulmonary fibrosis is a progressive scarring disease characterized by extracellular matrix accumulation and altered mechanical properties of lung tissue. Recent studies support the hypothesis that these compositional and mechanical changes create a progressive feed-forward loop in which enhanced matrix deposition and tissue stiffening contribute to fibroblast and myofibroblast differentiation and activation, which further perpetuates matrix production and stiffening. The biomechanical properties of tissues are sensed and responded to by mechanotransduction pathways that facilitate sensing of changes in mechanical cues by tissue resident cells and convert the mechanical signals into downstream biochemical signals. Although our understanding of mechanotransduction pathways associated with pulmonary fibrosis remains incomplete, recent progress has allowed us to begin to elucidate the specific mechanisms supporting fibrotic feed-forward loops. The mechanosensors discussed here include integrins, Piezo channels, transient receptor potential channels, and nonselective ion channels. Also discussed are downstream transcription factors, including myocardin-related transcription factor and Yes-associated protein/transcriptional coactivator with PDZ-binding motif. This review describes mechanosensors and mechanotransduction pathways associated with fibrosis progression and highlights promising therapeutic insights.


Subject(s)
Feedback, Physiological/physiology , Idiopathic Pulmonary Fibrosis/metabolism , Mechanotransduction, Cellular/physiology , Animals , Fibroblasts/metabolism , Humans
20.
J Immunol ; 205(11): 3205-3217, 2020 12 01.
Article in English | MEDLINE | ID: mdl-33115852

ABSTRACT

Tobacco smoke exposure is associated with multiple diseases including, respiratory diseases like asthma and chronic obstructive pulmonary disease. Tobacco smoke is a potent inflammatory trigger and is immunosuppressive, contributing to increased susceptibility to pulmonary infections in smokers, ex-smokers, and vulnerable populations exposed to secondhand smoke. Tobacco smoke exposure also reduces vaccine efficacy. Therefore, mitigating the immunosuppressive effects of chronic smoke exposure and improving the efficacy of vaccinations in individuals exposed to tobacco smoke, is a critical unmet clinical problem. We hypothesized that specialized proresolving mediators (SPMs), a class of immune regulators promoting resolution of inflammation, without being immunosuppressive, and enhancing B cell Ab responses, could reverse the immunosuppressive effects resulting from tobacco smoke exposure. We exposed mice to secondhand smoke for 8 wk, followed by a period of smoke exposure cessation, and the mice were immunized with the P6 lipoprotein from nontypeable Haemophilus influenzae, using 17-HDHA and aspirin-triggered-resolvin D1 (AT-RvD1) as adjuvants. 17-HDHA and AT-RvD1 used as adjuvants resulted in elevated serum and bronchoalveolar lavage levels of anti-P6-specific IgG and IgA that were protective, with immunized mice exhibiting more rapid bacterial clearance upon challenge, reduced pulmonary immune cell infiltrates, reduced production of proinflammatory cytokines, and less lung-epithelial cell damage. Furthermore, the treatment of mice with AT-RvD1 during a period of smoke-cessation further enhanced the efficacy of SPM-adjuvanted P6 vaccination. Overall, SPMs show promise as novel vaccine adjuvants with the ability to overcome the tobacco smoke-induced immunosuppressive effects.


Subject(s)
Immune Tolerance/immunology , Tobacco Smoke Pollution/adverse effects , Animals , Antibodies/immunology , Aspirin/immunology , Asthma/immunology , Asthma/microbiology , B-Lymphocytes/immunology , Bronchoalveolar Lavage Fluid/immunology , Cytokines/immunology , Docosahexaenoic Acids/immunology , Epithelial Cells/immunology , Epithelial Cells/microbiology , Female , Haemophilus Infections/immunology , Haemophilus Infections/microbiology , Haemophilus influenzae/immunology , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Inflammation/immunology , Inflammation/microbiology , Lipoproteins/immunology , Lung/immunology , Mice , Mice, Inbred C57BL , Pneumonia/immunology , Pneumonia/microbiology , Pulmonary Disease, Chronic Obstructive/immunology , Pulmonary Disease, Chronic Obstructive/microbiology
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