American journal of physiology. Lung cellular and molecular physiology最新文献

{"title":"Shear stress-induced restoration of pulmonary microvascular endothelial barrier function following ischemia reperfusion injury requires VEGFR2 signaling.","authors":"Don Walsh, Daria S Kostyunina, Aoife Blake, John Boylan, Paul McLoughlin","doi":"10.1152/ajplung.00200.2024","DOIUrl":"10.1152/ajplung.00200.2024","url":null,"abstract":"<p><p>Normal shear stress produced by blood flow is sensed by the vascular endothelium and required for maintenance of the homeostatic functions of the endothelium in systemic conduit and resistance vessels. Many critical illnesses are characterized by periods of abnormally reduced or absent shear stress in the lung (e.g., hemorrhagic shock, embolism, ischemia reperfusion injury, and lung transplantation) and are complicated by pulmonary edema following reperfusion due to microvascular leak. The role of shear stress in regulating the pulmonary microvascular endothelial barrier in the intact vascular bed has not been previously examined. We tested the hypothesis that, in lungs injured by a period of ischemia and reperfusion (IRI), reduced shear stress contributes to increased pulmonary microvascular endothelial barrier permeability and edema formation. Furthermore, we examined the role of vascular endothelial-derived growth factor receptor 2 (VEGFR2) as a mechanosensor mediating the endothelial response to this altered shear stress. Following IRI, we perfused isolated ventilated mouse lungs with a low viscosity solution (LVS) or a higher, physiological viscosity solution (PVS) at constant flow to produce differing endothelial shear stresses in the intact microcirculation. Lungs perfused with LVS developed pulmonary edema due to increased endothelial permeability whereas those perfused with PVS were protected from edema formation by reduced endothelial permeability. This effect of PVS required normal VEGFR2 mechanoreceptor function. These data show for the first time that shear stress has an important role in restoring endothelial barrier function in the intact pulmonary microcirculation following injury and have important implications for the treatment of pulmonary edema in critically ill patients.<b>NEW & NOTEWORTHY</b> Critical illnesses are frequently complicated by noncardiogenic pulmonary edema. Many such illnesses include periods of reduced blood flow, often accompanied by hemodilution, which together reduce endothelial shear stress. We report that in ischemia-reperfusion injury reduced shear stress contributes to increased permeability of the in situ pulmonary microvascular endothelium and worsens alveolar edema. Restoring shear stress toward normal reduces endothelial permeability and edema formation, an effect that requires the normal mechanoreceptor function of VEGFR2.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L389-L404"},"PeriodicalIF":3.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142863000","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":"The mysterious case of missing lymphocytes: a cautionary tale of interinstitutional variability in outcomes of lung dissociation protocols.","authors":"Olivia S Harlow, Vijay Raaj Ravi, Fang Ke, Nathan L Sanders, Elise Armstrong, Joseph P Mizgerd, Anukul T Shenoy","doi":"10.1152/ajplung.00323.2024","DOIUrl":"10.1152/ajplung.00323.2024","url":null,"abstract":"<p><p>Rigor and reproducibility are vital to scientific advancement. It is unclear whether a protocol optimized for tissue dissociation in one institution performs well universally. Here, we share our brand-new lab's experience with interinstitutional variability that led to the discovery that a protocol optimized for murine lung dissociation at Boston University (BU) fails to reproduce similar CD4⁺ T cell, CD8⁺ T cell, and B cell outcomes at the University of Michigan at Ann Arbor (U-M). We report that the type 2 collagenase-based protocol from BU yields reduced numbers of lung lymphocytes at U-M, and this appeared to be a result of harsher collagenase activity despite using identical protocols, reagents, and vendors at both institutions. This variability could not be explained by higher Ca²⁺ levels in Ann Arbor water (which we posited may heighten the collagenase activity) but instead appeared to be due to technical details within the protocol that led to the protocols behaving in an institution-specific manner. Indeed, we find that merely switching between the protocol from BU and a newly optimized protocol at U-M was sufficient to improve (or worsen) lymphocyte yields from murine lungs when synchronously performed at both institutions. Taken together, although the reason(s) for the interinstitutional variability in lymphocyte outcomes remains unknown, this report serves as a cautionary tale against directly adopting lung dissociation protocols across institutions without reoptimization, and calls for careful inspection of cross-institutional reproducibility of previously described protocols.<b>NEW & NOTEWORTHY</b> Rigor and reproducibility are vital to scientific advancement. It is unclear whether a protocol optimized for tissue dissociation in one institution performs well universally. Here, the authors share their experience with interinstitutional variability that led to the discovery that a protocol optimized for murine lung dissociation in one institution failed to reproduce similar lymphocyte outcomes elsewhere. This report, thus, serves as a cautionary tale against directly adopting tissue dissociation protocols across institutions without reoptimization.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L260-L266"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12178127/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941552","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}

{"title":"Vitamin D as an add-on therapy to phosphodiesterase-5 inhibitor in experimental pulmonary arterial hypertension.","authors":"Rui Adão, Bianca Barreira, Elena Paternoster, Daniel Morales-Cano, Miguel A Olivencia, Begoña Quintana-Villamandos, Diego A Rodríguez-Chiaradía, Angel Cogolludo, Francisco Perez-Vizcaino","doi":"10.1152/ajplung.00319.2024","DOIUrl":"10.1152/ajplung.00319.2024","url":null,"abstract":"<p><p>Severe vitamin D (vitD) deficiency is a very common condition in patients with pulmonary arterial hypertension (PAH), and it is a predictor of poor prognosis. There is emerging evidence suggesting a connection between the insufficient response to phosphodiesterase-5 inhibitors (PDE5i) and vitD deficiency in patients with PAH. In the present translational study, vitD deficiency was induced in Wistar rats by exposure to vitD-free diet for 5 wk and followed by Su5416 administration and hypoxia (10%) for 3 wk, a standard experimental model of PAH. Then, rats were randomized to either <i>1</i>) the PDE5i tadalafil and continuing vitD-free diet or <i>2</i>) tadalafil plus a single dose of vitD and standard diet for 4 wk. VitD supplementation improved exercise capacity and right ventricular function and decreased systolic right ventricular pressure, right atrial hypertrophy, right ventricular hypertrophy, and pulmonary arterial remodeling. VitD improved the ex vivo endothelium-dependent response to acetylcholine, indicating an improvement in NO bioavailability, which also resulted in an acute ex vivo response to sildenafil. Thus, the restoration of vitD, by rescuing endothelial function and PDE5i effectiveness, significantly improved the histological, hemodynamic, and functional features of rats with PAH. VitD may be especially beneficial for PDE5i-treated patients with PAH.<b>NEW & NOTEWORTHY</b> Severe vitamin D deficiency is very prevalent in patients with pulmonary arterial hypertension. We show that addition of vitamin D to the standard PDE5 inhibitor tadalafil increases its therapeutic efficacy in pulmonary hypertensive rats that were deficient in vitamin D.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L253-L259"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942641","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":"Caspase inhibition restores collagen Iα1 and fibronectin release in cigarette smoke extract-exposed human lung fibroblasts.","authors":"Agnese La Mensa, Marco Buscetta, Roy R Woldhuis, Maura Cimino, Maria Rita Giuffrè, Marta Cristaldi, Paola Dino, Luigi Fiore, Alberto Fucarino, Giovanna Lo Iacono, Alessandro Bertani, Corry-Anke Brandsma, Fabio Bucchieri, Chiara Cipollina","doi":"10.1152/ajplung.00214.2024","DOIUrl":"10.1152/ajplung.00214.2024","url":null,"abstract":"<p><p>Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by obstructed airflow, airway remodeling, and inflammation, with cigarette smoke (CS) exposure being the main risk factor. Although CS extract (CSE) has been shown to activate caspases in various cell types, the role of caspases in human lung fibroblasts (hLFs) in COPD remains poorly understood. Recent studies have linked caspases to extracellular matrix (ECM) remodeling in skin and kidney fibrosis. Caspase activation can be triggered by oxidative stress, with active caspase-3 executing the pore-forming protein gasdermin E (GSDME) in the cleaved N-terminal form GSDME-NT. We investigated whether CSE activates caspases and GSDME in hLFs and their role in ECM remodeling. MRC-5 lung fibroblasts were treated with CSE with or without the antioxidant <i>N</i>-acetyl-cysteine (NAC) and the caspase-8 inhibitor z-IETD-fmk. We measured the effects on caspase-1-8-3/7 activation, GSDME cleavage, ECM remodeling (procollagen Iα1, COLIα1, and fibronectin, FN), and mitochondrial superoxide (mSOX) generation. Key findings were validated in patient-derived hLFs (phLFs). Our results showed that CSE induced caspase-1-8-3/7 activation, mSOX generation, and decreased COLIα1 and FN levels in MRC-5. CSE caused caspase-8-dependent activation of caspase-3, leading to GSDME cleavage. Treatment with NAC inhibited mSOX and caspase activation. Inhibition of caspase-8 and mSOX restored FN and COLIα1 levels. In phLFs, we confirmed caspase-1 and -8 activation, mSOX increase, COLIα1/FN decrease, and the effects of NAC. Our findings highlight the role of the axis caspase-8-3/7-GSDME and mSOX in regulating ECM protein, suggesting that these pathways may contribute to remodeling in COPD.<b>NEW & NOTEWORTHY</b> This research investigates the connection between caspases, gasdermins, and extracellular matrix (ECM) remodeling in the context of cigarette smoke-associated lung diseases. The study found that cigarette smoke extract (CSE) activates caspases and gasdermin E in human lung fibroblasts, leading to decreased ECM protein expression and release. Findings herein reported suggest that targeting the caspase-8-3/7-gasdermin axis and mitochondrial reactive oxygen species may help restore ECM remodeling in chronic lung diseases associated with cigarette smoke exposure.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L239-L252"},"PeriodicalIF":3.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942649","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":"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 (O₃) causes upper and lower airway inflammation. We and others have previously demonstrated that O₃ oxidizes lipids, particularly cholesterol, into electrophilic oxysterols, such as secosterol B (SecoB), which can adduct proteins, thus altering cellular signaling pathways. To investigate how O₃-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 O₃ 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). O₃ 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. O₃ 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 O₃-induced IL-1β and VEGF increases, whereas males showed increased Eotaxin and reduced GM-CSF. Basolaterally, O₃ 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, O₃-induced cytokine/chemokine responses and sterol/oxysterol levels in HNECs vary by sex, with donor-specific oxysterols associated with O₃-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":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12147928/pdf/","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":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"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":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204138/pdf/","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":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"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":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12172090/pdf/","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":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of voltage-gated Ca²⁺ channels and Ano1 Ca²⁺-activated Cl^- 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 Ca²⁺ channels (LTCC) and Ano1 Ca²⁺-activated Cl^- 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_inh-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 Ca²⁺ 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 Ca²⁺ 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 Ca²⁺ influx by SERCA.<b>NEW & NOTEWORTHY</b> The role of L-type Ca²⁺ channels and Ano1 Ca²⁺-activated Cl^- 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 Ca²⁺ influx by sarcoplasmic endoplasmic reticulum Ca²⁺ 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_L), 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}

{"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>_sc) 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>_sc probe to measure <i>I</i>_sc 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}