Dre'Von A Dobson, Alexia Perryman, Erin McNell, Hye-Young H Kim, Ned A Porter, Meghan E Rebuli, Ilona Jaspers
{"title":"Evidence of sex differences in ozone-induced oxysterol and cytokine levels in differentiated human nasal epithelial cells.","authors":"Dre'Von A Dobson, Alexia Perryman, Erin McNell, Hye-Young H Kim, Ned A Porter, Meghan E Rebuli, Ilona Jaspers","doi":"10.1152/ajplung.00332.2024","DOIUrl":"10.1152/ajplung.00332.2024","url":null,"abstract":"<p><p>Acute exposure to ozone (O<sub>3</sub>) causes upper and lower airway inflammation. We and others have previously demonstrated that O<sub>3</sub> oxidizes lipids, particularly cholesterol, into electrophilic oxysterols, such as secosterol B (SecoB), which can adduct proteins, thus altering cellular signaling pathways. To investigate how O<sub>3</sub>-derived oxysterols influence cytokine and chemokine release, nasal epithelial cells (HNECs) from healthy donors (<i>n</i> = 18 donors) were exposed to 0.4 ppm O<sub>3</sub> for 4 h. Afterward, immune mediators in apical washes and basolateral supernatants were analyzed using ELISAs, whereas sterol and oxysterol levels were examined using liquid-chromatography mass spectrometry (LC-MS). O<sub>3</sub> exposure increased SecoB, 7-ketocholesterol (7Keto-Chol), 27-hydroxycholesterol (27OH-Chol), and epoxycholesterols in a sex-dependent manner. Female-derived HNECs had significant increases in SecoB, 27OH-Chol, and β-epoxycholesterol, whereas male-derived cells showed increases in 7Keto-Chol only. O<sub>3</sub> decreased the release of granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-7 but increased interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), VEGF, and Eotaxin. Females exhibited O<sub>3</sub>-induced IL-1β and VEGF increases, whereas males showed increased Eotaxin and reduced GM-CSF. Basolaterally, O<sub>3</sub> exposure decreased GM-CSF and thymus and activation-regulated chemokine (TARC) while raising IL-6, IL-13, IL-1β, IL-8, and TNFα. Females showed higher TNFα and IL-1β, but males did not. Oxysterols correlated differently with cytokines by sex. Females showed positive correlations between oxysterols and proinflammatory cytokines like IL-6 and IL-1β, whereas males displayed negative correlations with IL-6, IL-8, and TNFα. In conclusion, O<sub>3</sub>-induced cytokine/chemokine responses and sterol/oxysterol levels in HNECs vary by sex, with donor-specific oxysterols associated with O<sub>3</sub>-triggered inflammatory mediator release.<b>NEW & NOTEWORTHY</b> It is increasingly recognized that lung biology and responses to pollutant exposures differ in males and females. Using a model of differentiated nasal epithelial cells from male and female donors, our data demonstrate that pollutant-induced cytokine/chemokine responses and oxidized lipid levels vary by sex, with donor-specific oxidized lipids linked to inflammatory mediator release.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L207-L214"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142881075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kun Woo D Shin, M Volkan Atalay, Rengul Cetin-Atalay, Erin M O'Leary, Mariel E Glass, Jennifer C Houpy Szafran, Parker S Woods, Angelo Y Meliton, Obada R Shamaa, Yufeng Tian, Gökhan M Mutlu, Robert B Hamanaka
{"title":"mTOR signaling regulates multiple metabolic pathways in human lung fibroblasts after TGF-β and in pulmonary fibrosis.","authors":"Kun Woo D Shin, M Volkan Atalay, Rengul Cetin-Atalay, Erin M O'Leary, Mariel E Glass, Jennifer C Houpy Szafran, Parker S Woods, Angelo Y Meliton, Obada R Shamaa, Yufeng Tian, Gökhan M Mutlu, Robert B Hamanaka","doi":"10.1152/ajplung.00189.2024","DOIUrl":"10.1152/ajplung.00189.2024","url":null,"abstract":"<p><p>Idiopathic pulmonary fibrosis is a fatal disease characterized by the transforming growth factor (TGF-β)-dependent activation of lung fibroblasts, leading to excessive deposition of collagen proteins and progressive replacement of healthy lungs with scar tissue. We and others have shown that TGF-β-mediated activation of the mechanistic target of rapamycin complex 1 (mTORC1) and downstream upregulation of activating transcription factor 4 (ATF4) promotes metabolic reprogramming in lung fibroblasts characterized by upregulation of the de novo synthesis of glycine, the most abundant amino acid found in collagen protein. Whether mTOR and ATF4 regulate other metabolic pathways in lung fibroblasts has not been explored. Here, we used RNA sequencing to determine how both ATF4 and mTOR regulate gene expression in human lung fibroblasts following TGF-β. We found that ATF4 primarily regulates enzymes and transporters involved in amino acid homeostasis as well as aminoacyl-tRNA synthetases. mTOR inhibition resulted not only in the loss of ATF4 target gene expression but also in the reduced expression of glycolytic enzymes and mitochondrial electron transport chain subunits. Analysis of TGF-β-induced changes in cellular metabolite levels confirmed that ATF4 regulates amino acid homeostasis in lung fibroblasts, whereas mTOR also regulates glycolytic and TCA cycle metabolites. We further analyzed publicly available single-cell RNA-seq datasets and found increased expression of ATF4 and mTOR-regulated genes in pathologic fibroblast populations from the lungs of patients with IPF. Our results provide insight into the mechanisms of metabolic reprogramming in lung fibroblasts and highlight novel ATF4 and mTOR-dependent pathways that may be targeted to inhibit fibrotic processes.<b>NEW & NOTEWORTHY</b> Here, we used transcriptomic and metabolomic approaches to develop a more complete understanding of the role that mTOR, and its downstream effector ATF4, play in promoting metabolic reprogramming in lung fibroblasts. We identify novel metabolic pathways that may promote pathologic phenotypes, and we provide evidence from single-cell RNA-seq datasets that similar metabolic reprogramming occurs in patient lungs.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L215-L228"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142913182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Li Y Drake, Benjamin B Roos, Sarah A Wicher, Latifa Khalfaoui, Lisa L Nesbitt, Yun Hua Fang, Christina M Pabelick, Y S Prakash
{"title":"Aging, brain-derived neurotrophic factor, and allergen-induced pulmonary responses in mice.","authors":"Li Y Drake, Benjamin B Roos, Sarah A Wicher, Latifa Khalfaoui, Lisa L Nesbitt, Yun Hua Fang, Christina M Pabelick, Y S Prakash","doi":"10.1152/ajplung.00145.2024","DOIUrl":"10.1152/ajplung.00145.2024","url":null,"abstract":"<p><p>Asthma in the elderly is being recognized as more severe, resistant to standard therapies, and having greater morbidity. Therefore, it becomes important to understand the impact of aging-associated airway structure and functional changes toward pathogenesis of asthma in the elderly. Here, airway smooth muscle plays important roles in airway hyperreactivity and structural remodeling. The role of smooth muscle in asthma can be modulated by growth factors [including neurotrophins such as brain-derived neurotrophic factor (BDNF)] and proinflammatory senescence factors. In this study, we investigated aging effects on airway hyperreactivity, structural remodeling, inflammation, and senescence in a mouse model of allergic asthma. C57BL/6J wild-type mice or smooth muscle-specific BDNF knockout mice at 4, 18, and 24 mo of age were intranasally exposed to mixed allergens (MAs, ovalbumin, <i>Aspergillus</i>, <i>Alternaria</i>, and house dust mite) over 4 wk. Assessing lung function by flexiVent, we found that compared with 4-mo-old mice, 18- and 24-mo-old C57BL/6J mice showed decreased airway resistance and increased airway compliance after PBS or MA treatment. Deletion of smooth muscle BDNF blunted airway hyperreactivity in aged mice. Lung histology analysis revealed that aging increased bronchial airway thickness and decreased lung inflammation. Multiplex assays showed that aging largely reduced allergen-induced lung expression of proinflammatory chemokines and cytokines. By immunohistochemistry staining, we found that aging increased bronchial airway expression of senescence markers, including p21, phospho-p53, and phospho-γH2A.X. Our data suggest that aging-associated increase of airway senescence in the context of allergen exposure may contribute to asthma pathology in the elderly.<b>NEW & NOTEWORTHY</b> The pathogenesis of asthma in elderly is not well understood. Using a mouse model of asthma, we show that aging results in decreased lung function and less responsiveness to allergen exposure, impacted by locally produced brain-derived neurotrophic factor. Aging also decreases allergen-induced inflammation but increases airway remodeling and senescence. Our results suggest that senescence pathways may contribute to asthma pathogenesis in elderly.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L290-L300"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142492916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Srijit Ghosh, Tuleen Alkawadri, Lorcan P McGarvey, Mark A Hollywood, Keith D Thornbury, Gerard P Sergeant
{"title":"Role of voltage-gated Ca<sup>2+</sup> channels and Ano1 Ca<sup>2+</sup>-activated Cl<sup>-</sup> channels in M2 muscarinic receptor-dependent contractions of murine airway smooth muscle.","authors":"Srijit Ghosh, Tuleen Alkawadri, Lorcan P McGarvey, Mark A Hollywood, Keith D Thornbury, Gerard P Sergeant","doi":"10.1152/ajplung.00188.2024","DOIUrl":"10.1152/ajplung.00188.2024","url":null,"abstract":"<p><p>Cholinergic tone is elevated in obstructive lung conditions such as chronic obstructive pulmonary disease (COPD) and asthma, but the cellular mechanisms underlying cholinergic contractions of airway smooth muscle (ASM) are still unclear. Some studies report an important role for L-type Ca<sup>2+</sup> channels (LTCC) and Ano1 Ca<sup>2+</sup>-activated Cl<sup>-</sup> channels (CACC) in these responses, but others dispute their importance. Cholinergic contractions of ASM involve activation of M3Rs, however, stimulation of M2Rs exerts a profound hypersensitization of these responses. Here, we show that M2R-dependent potentiation of cholinergic nerve-evoked contractions of ASM was reversed by the LTCC blocker nifedipine and the Ano1 CACC inhibitors Ani9 and CaCC<sub>inh</sub>-A01. Carbachol induced sustained contractions of ASM that were converted into oscillatory contractions when M3Rs were blocked with 4-DAMP. The 4-DAMP-resistant contractions were absent in preparations taken from M2R knockout (KO) mice. The remaining M2R-dependent responses, observed in wild-type (WT) mice, were abolished by nifedipine and Ani9. Inhibition of sarcoplasmic endoplasmic reticulum Ca<sup>2+</sup> ATPases (SERCA) with thapsigargin increased the amplitude of contractions induced by electrical field stimulation (EFS) and these effects were also reversed by nifedipine and Ani9. Thapsigargin also potentiated contractions of ASM induced by the LTCC activator FPL64176. Therefore, contractions of ASM that involved Ca<sup>2+</sup> influx via LTCC were enhanced by inhibition of SERCA. Immunocytochemistry experiments revealed prominent SERCA staining around the periphery of ASM cells. These data indicate that M2R-dependent contractions of ASM involve Ano1 CACC and LTCC by a mechanism involving inhibition of buffering of Ca<sup>2+</sup> influx by SERCA.<b>NEW & NOTEWORTHY</b> The role of L-type Ca<sup>2+</sup> channels and Ano1 Ca<sup>2+</sup>-activated Cl<sup>-</sup> channels in cholinergic contractions of airway smooth muscle is disputed. Here, we show that both channels are involved in M2 muscarinic receptor-dependent contractions of murine airway smooth muscle via inhibition of buffering of Ca<sup>2+</sup> influx by sarcoplasmic endoplasmic reticulum Ca<sup>2+</sup> ATPases.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L301-L312"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Opioid-induced respiratory depression: clinical aspects and pathophysiology of the respiratory network effects.","authors":"Brian A Baldo","doi":"10.1152/ajplung.00314.2024","DOIUrl":"10.1152/ajplung.00314.2024","url":null,"abstract":"<p><p>Important insights and consensus remain lacking for risk prediction of opioid-induced respiratory depression (OIRD), reversal of respiratory depression (RD), the pathophysiology of OIRD, and which sites make the most significant contribution to its induction. The ventilatory response to inhaled carbon dioxide is the most sensitive biomarker of OIRD. To accurately predict respiratory depression (RD), a multivariant RD prospective trial using continuous capnography and oximetry examining five independent variables, age ≥60, sex, opioid naivety, sleep disorders, and chronic heart failure (PRODIGY trial), were undertaken. Intermittent oximetry alone substantially underestimates the incidence of RD. Naloxone, with an elimination half-life of ∼33 min (cf. morphine 2-3 h; fentanyl and congeners only 5-15 min), has limitations for the rescue of patients with severe OIRD. Buprenorphine is potentially valuable in patients being treated long term since its high µ-receptor (MOR) affinity makes it difficult for an opioid of lower affinity (e.g., fentanyl) to displace it from the receptor. In the last decade, synthetic opioids, for example, fentanyl, its potent analogs such as carfentanil, and the benzimidazole derivative nitazene \"superagonists\" have contributed to the exponential growth in opioid deaths due to RD. The MOR, encoded by gene <i>Oprm1</i>, is widely expressed in the central and peripheral nervous systems, including centers that modulate breathing. Opioids bind to the receptors, but consensus is lacking on which site(s) makes the most significant contribution to the induction of OIRD. Both the preBötzinger complex (preBötC), the inspiratory rhythm generator, and the Kölliker-Fuse nucleus (KFN), the respiratory modulator, contribute to RD, but receptor binding is not restricted to a single site. Breathing is composed of three phases, inspiration, postinspiration, and active expiration, each generated by distinct rhythm-generating networks: the preBötC, the postinspiratory complex (PiCo), and the lateral parafacial nucleus (pF<sub>L</sub>), respectively. Somatostatin-expressing mouse cells involved in breathing regulation are not involved in opioid-induced RD.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L267-L289"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142891430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
David O Otuya, Zhongyu Liu, Reny Joseph, Mohammed A Hanafy, Kadambari Vijaykumar, Denise Stanford, S Vamsee Raju, Elizabeth H Baker, Steven M Rowe, Guillermo J Tearney, George M Solomon
{"title":"Toward in vivo bronchoscopic functional CFTR assessment using a short circuit current measurement probe.","authors":"David O Otuya, Zhongyu Liu, Reny Joseph, Mohammed A Hanafy, Kadambari Vijaykumar, Denise Stanford, S Vamsee Raju, Elizabeth H Baker, Steven M Rowe, Guillermo J Tearney, George M Solomon","doi":"10.1152/ajplung.00137.2024","DOIUrl":"10.1152/ajplung.00137.2024","url":null,"abstract":"<p><p>The epithelial lining of luminal organs provides an immune barrier against external factors and regulates the transport of nutrients, ions, and water into the body. Several conditions are associated with the breakdown or dysfunction of the epithelial lining. Short circuit current (<i>I</i><sub>sc</sub>) measurement using a bulky, expensive, and hard-to-deploy system known as the Ussing chamber is the gold standard for evaluation of epithelial transport function but requires tissue excision. We demonstrated the ability of the <i>I</i><sub>sc</sub> probe to measure <i>I</i><sub>sc</sub> in normal wild type (WT) versus reduced cystic fibrosis transmembrane conductance regulator (CFTR) function knockout (KO) rats as a relevant animal model for testing ion channel function.<b>NEW & NOTEWORTHY</b> We have conducted short circuit current measurements in animal models in vivo for studying cystic fibrosis transmembrane conductance regulator (CFTR) and ion channel restoration.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L313-L320"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142724783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"CFTR as a therapeutic target for severe lung infection.","authors":"Jaime L Hook, Wolfgang M Kuebler","doi":"10.1152/ajplung.00289.2024","DOIUrl":"10.1152/ajplung.00289.2024","url":null,"abstract":"<p><p>Lung infection is one of the leading causes of morbidity and mortality worldwide. Even with appropriate antibiotic and antiviral treatment, mortality in hospitalized patients often exceeds 10%, highlighting the need for the development of new therapeutic strategies. Of late, cystic fibrosis transmembrane conductance regulator (CFTR) is-in addition to its well-established roles in the lung airway and extrapulmonary organs-increasingly recognized as a key regulator of alveolar homeostasis and defense. In the alveolar epithelium, CFTR mediates alveolar fluid secretion and liquid homeostasis; in the microvascular endothelium, CFTR maintains vascular barrier function. CFTR also contributes to alveolar immunity. Yet, in lung infection, diverse molecular mechanisms reduce CFTR abundance and otherwise impair its function, promoting alveolar inflammation, edema, and cell death. Preservation or restoration of CFTR function by CFTR modulator drugs thus presents a promising avenue to combat lung infection in a pathogen-independent manner.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L229-L238"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K Mora Massad, Z Dai, I Petrache, C E Ventetuolo, T Lahm
{"title":"Lung Endothelial Cell Heterogeneity in Health and Pulmonary Vascular Disease.","authors":"K Mora Massad, Z Dai, I Petrache, C E Ventetuolo, T Lahm","doi":"10.1152/ajplung.00296.2024","DOIUrl":"10.1152/ajplung.00296.2024","url":null,"abstract":"<p><p>Lung endothelial cells (ECs) are essential for maintaining organ function and homeostasis. Despite sharing some common features with ECs from organ systems, lung ECs exhibit significant heterogeneity in morphology, function, and gene expression. This heterogeneity is increasingly recognized as a key contributor to the development of pulmonary diseases like pulmonary hypertension (PH). In this mini-review, we explore the evolving understanding of lung EC heterogeneity, particularly through the lens of single-cell RNA sequencing (scRNA-seq) technologies. These advances have provided unprecedented insights into the diverse EC subpopulations, their specific roles, and the disturbances in their homeostatic functions that contribute to PH pathogenesis. In particular, these studies identified novel and functionally distinct cell types such as aerocytes and general capillary ECs that are critical for maintaining lung function in health and disease. In addition, multiple novel pathways and mechanisms have been identified that contribute to aberrant pulmonary vascular remodeling in PH. Emerging techniques like single-nucleus RNA sequencing and spatial transcriptomics have further pushed the field forward by discovering novel disease mediators. As research continues to leverage these advanced techniques, the field is poised to uncover novel EC subtypes and disease mechanisms, paving the way for new therapeutic targets in PH and other lung diseases.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rashmi J Rao, Jimin Yang, Siyi Jiang, Wadih El-Khoury, Neha Hafeez, Satoshi Okawa, Yi Yin Tai, Ying Tang, Yassmin Al Aaraj, John C Sembrat, Stephen Y Chan
{"title":"Post-transcriptional regulation of IFI16 promotes inflammatory endothelial pathophenotypes observed in pulmonary arterial hypertension.","authors":"Rashmi J Rao, Jimin Yang, Siyi Jiang, Wadih El-Khoury, Neha Hafeez, Satoshi Okawa, Yi Yin Tai, Ying Tang, Yassmin Al Aaraj, John C Sembrat, Stephen Y Chan","doi":"10.1152/ajplung.00048.2024","DOIUrl":"10.1152/ajplung.00048.2024","url":null,"abstract":"<p><p>Pulmonary arterial hypertension (PAH) is a progressive disease driven by endothelial cell inflammation and dysfunction, resulting in the pathological remodeling of the pulmonary vasculature. Innate immune activation has been linked to PAH development; however, the regulation, propagation, and reversibility of the induction of inflammation in PAH are poorly understood. Here, we demonstrate the role of interferon-inducible protein 16 (IFI16), an innate immune sensor, as a modulator of endothelial inflammation in pulmonary hypertension, using human pulmonary artery endothelial cells (PAECs). Inflammatory stimulus of PAECs with IL-1β upregulates <i>IFI16</i> expression, inducing proinflammatory cytokine upregulation and cellular apoptosis. <i>IFI16</i> mRNA stability is regulated by post-transcriptional m6A modification, mediated by Wilms' tumor 1-associated protein (WTAP), a structural stabilizer of the methyltransferase complex, via regulation of m6A methylation of <i>IFI16</i>. In addition, m6A levels are increased in the peripheral blood mononuclear cells of patients with PAH compared with control, indicating that quantifying this epigenetic change in patients may hold potential as a biomarker for disease identification. In summary, our study demonstrates that IFI16 mediates inflammatory endothelial pathophenotypes seen in pulmonary arterial hypertension.<b>NEW & NOTEWORTHY</b> Our work establishes a paradigm of the regulatory role of the Wilms' tumor 1-associated protein (WTAP)-interferon inducible protein 16 (IFI16) axis that uses m6A RNA methylation to drive endothelial inflammatory activation in pulmonary hypertension. Consequently, because m6A epigenetic modifications are both reversible and dynamic, this axis is an attractive diagnostic and therapeutic target in pulmonary hypertension and more broadly in endothelial immune activation.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L148-L158"},"PeriodicalIF":3.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11905863/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142806071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Barbara Summers, Kihwan Kim, Anjali Trivedi, Tyler M Lu, Sean Houghton, Jade Palmer-Johnson, Joselyn Rojas-Quintero, Juan Cala-Garcia, Tania Pannellini, Francesca Polverino, Raphaël Lis, Hasina Outtz Reed
{"title":"Mice with lymphatic dysfunction develop pathogenic lung tertiary lymphoid organs that model an autoimmune emphysema phenotype of COPD.","authors":"Barbara Summers, Kihwan Kim, Anjali Trivedi, Tyler M Lu, Sean Houghton, Jade Palmer-Johnson, Joselyn Rojas-Quintero, Juan Cala-Garcia, Tania Pannellini, Francesca Polverino, Raphaël Lis, Hasina Outtz Reed","doi":"10.1152/ajplung.00209.2024","DOIUrl":"10.1152/ajplung.00209.2024","url":null,"abstract":"<p><p>We have previously shown that mice with a loss of C-type lectin-like type II (CLEC2), which have lymphatic dysfunction due to the role of CLEC2 in platelets for maintaining separation between the venous and lymphatic system, develop lung tertiary lymphoid organ (TLO) formation and lung injury that resembles an emphysema phenotype of chronic obstructive pulmonary disease (COPD). We now sought to investigate whether and how TLOs in these mice may play a pathogenic role in lung injury that is relevant to human disease. We found that inhibiting TLO formation using an anti-CD20 antibody in CLEC2-deficient mice partially blocked the development of emphysema. TLOs in CLEC2-deficient mice were rich in plasma cells and were a source of a broad array of autoantibodies. Chronic cigarette smoke exposure increased the size and number of lung TLOs in CLEC2-deficient mice and was associated with increased markers of antigen presentation and maturation, leading to increased autoantibody deposition. Using lung tissue from patients with COPD, we found an increase in lymphatic markers in patients with an emphysema phenotype and autoreactive TLOs compared with patients with COPD without emphysema that lack prominent TLOs. Taken together, these results demonstrate that emphysema in mice with lymphatic dysfunction can be partially rescued by blocking TLO formation and that these TLOs are the source of autoantibodies that are exacerbated by cigarette smoke. Our work suggests that lymphatic dysfunction in mice may recapitulate some aspects of an autoimmune emphysema phenotype that is seen in a subset of patients with COPD.<b>NEW & NOTEWORTHY</b> The lymphatic vasculature has been implicated in the pathogenesis of lung disease but remains understudied. Here, the authors use a mouse model to show that lymphatic dysfunction leads to a phenotype of emphysema that is characterized by lung tertiary lymphoid organs that are autoreactive and pathogenic. Analysis of human tissue showed increased lymphatic markers in autoimmune emphysema with prominent TLOs, compared with other COPD phenotypes.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L1-L14"},"PeriodicalIF":3.6,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11905800/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142492938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}