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

{"title":"<i>Pseudomonas aeruginosa</i> ExoY infection of pulmonary microvascular endothelial cells releases cyclic nucleotides into the extracellular compartment.","authors":"Madeline Stone, Chung-Sik Choi, Nandita Dey, Grace Swain, Troy Stevens, Sarah L Sayner","doi":"10.1152/ajplung.00038.2024","DOIUrl":"10.1152/ajplung.00038.2024","url":null,"abstract":"<p><p>Type three secretion system (TTSS)-competent Pseudomonas aeruginosa expressing soluble promiscuous cyclase, exoenzyme Y (ExoY), generates cyclic nucleotides in pulmonary microvascular endothelial cells (PMVECs). Within cells, cyclic nucleotide signals are highly compartmentalized, but these second messengers are also released into the extracellular space. Although agonist stimulation of endogenous adenylyl cyclase (AC) or the presence of ExoY increases cyclic nucleotides, the proportion of the signal that is in the intracellular versus extracellular compartments is unresolved. Furthermore, it is unclear whether <i>P. aeruginosa</i> primary infection or treatment with sterile media supernatants derived from a primary infection alters beta-adrenergic agonist-induced elevations in cAMP in PMVECs. Herein, we determine that PMVECs release cAMP into the extracellular space constitutively, following beta-adrenergic stimulation of endogenous AC, and following infection with <i>P. aeruginosa</i> expressing ExoY. Surprisingly, in PMVECs, only a small proportion of cGMP is detected within the cell at baseline or following <i>P. aeruginosa</i> ExoY infection with a larger proportion of total cGMP being detected extracellularly. Thus, the ability of lung endothelium to generate cyclic nucleotides may be underestimated by examining intracellular cyclic nucleotides alone, since a large portion is delivered into the extracellular compartment. In addition, <i>P. aeruginosa</i> infection or treatment with sterile media supernatants from a primary infection suppresses the beta-adrenergic cAMP response, which is further attenuated by the expression of functional ExoY. These findings reveal an overabundance of extracellular cyclic nucleotides following infection with ExoY expressing TTSS-competent <i>P. aeruginosa</i>.<b>NEW & NOTEWORTHY</b> <i>P. aeruginosa</i> exoenzyme Y (ExoY) infection increases cyclic nucleotides intracellularly, but an overabundance of cAMP and cGMP is also detected in the extracellular space and reveals a greater capacity of pulmonary endothelial cells to generate cAMP and cGMP. <i>P. aeruginosa</i> infection or treatment with sterile media supernatants derived from a primary infection suppresses the β-adrenergic-induced cAMP response in pulmonary endothelial cells, which is exacerbated by the expression of functional ExoY.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L756-L768"},"PeriodicalIF":4.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11560077/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142339326","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":"LMTK2 switches on canonical TGF-β1 signaling in human bronchial epithelial cells.","authors":"Daniel F Cruz, Joshua Donovan, Ewelina D Hejenkowska, Fangping Mu, Ipsita Banerjee, Maja Köhn, Carlos M Farinha, Agnieszka Swiatecka-Urban","doi":"10.1152/ajplung.00034.2024","DOIUrl":"10.1152/ajplung.00034.2024","url":null,"abstract":"<p><p>Transforming growth factor (TGF-β1) is a critical profibrotic mediator in chronic lung disease, and there are no specific strategies to mitigate its adverse effects. Activation of TGF-β1 signaling is a multipart process involving ligands, transmembrane receptors, and transcription factors. In addition, an intricate network of adaptor proteins fine-tunes the signaling strength, duration, and activity. Namely, Smad7 recruits growth arrest and DNA damage (GADD34) protein that then interacts with the catalytic subunit of phosphoprotein phosphatase 1 (PP1c) to inactivate TGF-β receptor (TβR)-I and downregulate TGF-β1 signaling. Little is known about how TGF-β1 releases TβR-I from the GADD34-PP1c inhibition to activate its signaling. Transmembrane lemur tyrosine kinase 2 (LMTK2) is a PP1c inhibitor, and our published data showed that TGF-β1 recruits LMTK2 to the cell surface. Here, we tested the hypothesis that TGF-β1 recruits LMTK2 to inhibit PP1c, allowing activation of TβR-I. First, LMTK2 interacted with the TGF-β1 pathway in the human bronchial epithelium at multiple checkpoints. Second, TGF-β1 inhibited PP1c by an LMTK2-dependent mechanism. Third, TGF-β1 used LMTK2 to activate canonical Smad3-mediated signaling. We propose a model whereby the LMTK2-PP1c and Smad7-GADD34-PP1c complexes serve as on-and-off switches in the TGF-β1 signaling in human bronchial epithelium.<b>NEW & NOTEWORTHY</b> Activation of the transforming growth factor (TGF)-β1 signaling pathway is complex, involving many ligands, transmembrane receptors, transcription factors, and modulating proteins. The mechanisms of TGF-β1 signaling activation/inactivation are not fully understood. We propose for the first time a model by which transmembrane lemur tyrosine kinase 2 (LMTK2) forms a complex with phosphoprotein phosphatase 1 (PP1c) to activate TGF-β1 signaling and Smad7, growth arrest and DNA damage (GADD34), and PP1C form a complex to inactivate TGF-β1 signaling in human bronchial epithelium.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L769-L782"},"PeriodicalIF":4.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11560069/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142339333","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":"Normalization of Muc5b ameliorates airway mucus plugging during persistent <i>Pseudomonas aeruginosa</i> infection in the CFTR^-/- rat.","authors":"Mikayla Murphree-Terry, Johnathan D Keith, Ashley M Oden, Susan E Birket","doi":"10.1152/ajplung.00381.2023","DOIUrl":"10.1152/ajplung.00381.2023","url":null,"abstract":"<p><p>In cystic fibrosis, the airway gel-forming mucin MUC5B accumulates in the airways, preventing clearance of pathogens like <i>Pseudomonas aeruginosa</i> (PA). The cystic fibrosis transmembrane conductance regulator (CFTR)^-/- (KO) rat model exhibits a similar accumulation of Muc5b. Our lab has shown that increased Muc5b precipitates the development of chronic PA infection. We hypothesized that reducing Muc5b in the KO rat airway would prevent occlusive mucus plugs and development of persistent PA infection. Six-month-old KO rats received Muc5b or scramble siRNA via intratracheal instillation. Rats were then inoculated with 10⁶ colony-forming units of mucoid <i>P. aeruginosa</i> isolate PAM57-15 and euthanized at 3- or 14-days post infection (dpi) to assess acute and persistent infection. At 14 dpi, Muc5b siRNA-treated KO rats had increased weight, decreased neutrophilic inflammation, and reduced mucus plugging in the small airways compared with scramble-treated KO and WT rats. These results indicate that pharmacological intervention of Muc5b reduces mucus plugging during persistent PA infection.<b>NEW & NOTEWORTHY</b> Although highly effective modulator therapies for cystic fibrosis (CF) have improved mucus-related outcomes of disease for people with CF, eradication of <i>Pseudomonas aeruginosa</i> (PA) infection has not been achieved in this population. In addition, current therapies for CF do not target mucin hypersecretion directly. Here, we show that a novel approach of normalizing airway Muc5b hypersecretion ameliorates infection-induced mucus plugging and neutrophilic inflammation during persistent PA infection in CFTR^-/- rats.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L672-L683"},"PeriodicalIF":4.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11563644/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142339338","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":"A new Anticalin protein for IL-23 inhibits non-type 2 allergen-driven mouse lung inflammation and airway hyperresponsiveness.","authors":"Thayse R Brüggemann, Nandini Krishnamoorthy, Matthias Hagner, Gabriele Matschiner, Thomas Jaquin, Luciana P Tavares, Hong Yong Peh, Bruce D Levy","doi":"10.1152/ajplung.00295.2023","DOIUrl":"10.1152/ajplung.00295.2023","url":null,"abstract":"<p><p>Severe asthma is a syndromic label assigned to patients based on clinical parameters, yet there are diverse underlying molecular endotypes in severe asthma pathobiology. Immunophenotyping of asthma biospecimens commonly includes a mixture of granulocytes and lymphocytes. Recently, a subset of patients with severe asthma was defined as non-type 2 with neutrophil-enriched inflammation associated with increased Th17 CD4⁺ T cells and IL-17 levels. Here, we used an allergen-driven mouse model of increased IL-17 and mixed granulocyte lung inflammation to determine the impact of upstream regulation by an Anticalin protein that specifically binds IL-23. Airway administration of the IL-23-binding Anticalin protein (AcIL-23) decreased lung neutrophils, eosinophils, macrophages, lymphocytes, IL-17⁺ CD4 T cells, mucous cell metaplasia, and methacholine-induced airway hyperresponsiveness. Selective targeting of IL-23 with a monoclonal antibody (IL-23p19; αIL-23) also decreased macrophages, IL-17⁺ CD4 T cells, and airway hyperresponsiveness. In contrast, a monoclonal antibody against IL-17A (αIL-17A) had no significant effect on airway hyperresponsiveness but did decrease lung neutrophils, macrophages, and IL-17⁺ CD4 T cells. Targeting the IL-23 pathway did not significantly change IL-5⁺ or IL-13⁺ CD4 T cells. Together, these data indicate that airway AcIL-23 mirrored the activity of systemic anti-IL-23 antibody to decrease airway hyperresponsiveness in addition to mixed granulocytic inflammation and that these protective actions were broader than blocking IL-17A or IL-5 alone, which selectively decreased airway neutrophils and eosinophils, respectively.<b>NEW & NOTEWORTHY</b> This is the first report of an Anticalin protein engineered to neutralize IL-23 (AcIL-23). Airway administration of AcIL-23 in mice regulated allergen-driven airway inflammation, mucous cell metaplasia, and methacholine-induced airway hyperresponsiveness. In mixed granulocytic allergic lung inflammation, immune regulation of IL-23 was broader than neutralization of either IL-17 or IL-5.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L624-L633"},"PeriodicalIF":3.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11563638/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141892692","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":"Maternal thirdhand exposure to e-cigarette vapor alters lung and bone marrow immune cell responses in offspring in the absence or presence of influenza infection.","authors":"Chantal Donovan, Andrew E Thorpe, Rochelle Yarak, Madison Coward-Smith, Amber L Pillar, Henry M Gomez, Min Feng, Xu Bai, Meng Wang, Dia Xenaki, Jay C Horvat, Hui Chen, Brian G G Oliver, Richard Y Kim","doi":"10.1152/ajplung.00078.2024","DOIUrl":"10.1152/ajplung.00078.2024","url":null,"abstract":"<p><p>There is increasing evidence that thirdhand exposure to e-cigarette vapor (e-vapor) can have detrimental effects on the lungs. However, whether maternal exposure during pregnancy results in harmful changes to the offspring is unknown. Using two different e-cigarette settings (low vs. high power), BALB/c mice were subjected to thirdhand e-vapor (e-vapor deposited onto towels, towels changed daily) in the absence or presence of nicotine, before, during, and after pregnancy. Male adult offspring were then infected with mouse-adapted influenza A virus (A/PR/8/34 H1N1; Flu) and lung and bone marrow immune cell responses were assessed 7 days postinfection. Maternal thirdhand exposure to low-power (_MLP) or high-power (_MHP) e-vapor with nicotine (_MLP + NIC and _MHP + NIC, respectively) increased the percentage of lung immune cells and neutrophils in the bone marrow. Interestingly, Flu-infected offspring from _MLP + NIC and _MHP + NIC groups had lower percentages of lung alveolar macrophages and more pronounced increases in neutrophils in the bone marrow, when compared with offspring from _MSham Flu controls. Flu infection also decreased the percentage of lung CD4+ T cells and increased the percentage of lung CD8+ T cells, irrespective of maternal exposure (_MLP -/+ NIC and _MHP -/+ NIC). Significantly, both _MLP + NIC and _MHP + NIC resulted in blunted activation of lung CD4+ T cells, but only _MLP + NIC caused blunted activation of lung CD8+ T cells. Together, we show for the first time that maternal thirdhand exposure to e-vapor results in significant, long-lived effects on lung and bone marrow immune cell responses in offspring at baseline and response to Flu infection.<b>NEW & NOTEWORTHY</b> Maternal exposure to environmental residues of e-cigarette use has significant effects on immune cell responses in the lungs and bone marrow of offspring at both baseline and in response to influenza A virus (Flu) infection.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L796-L806"},"PeriodicalIF":3.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142339335","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":"Effects of glial-derived neurotrophic factor on remodeling and mitochondrial function in human airway smooth muscle cells.","authors":"Li Y Drake, Benjamin B Roos, Jacob J Teske, Niyati A Borkar, Savita Ayyalasomayajula, Courtney Klapperich, Maunick Lefin Koloko Ngassie, Christina M Pabelick, Y S Prakash","doi":"10.1152/ajplung.00101.2024","DOIUrl":"10.1152/ajplung.00101.2024","url":null,"abstract":"<p><p>Airway smooth muscle (ASM) cells play important roles in airway remodeling of asthma. Our previous studies show that in vivo administration of glial-derived neurotrophic factor (GDNF) in mice induces thickening and collagen deposition in bronchial airways, whereas chelation of GDNF by GFRα1-Fc attenuates airway remodeling in the context of allergen exposure. To determine whether GDNF has direct effects on ASM, in this study, we examined GDNF in ASM cells from normal versus asthmatic humans. We found that GDNF treatment of human ASM cells had only minor effects on cell proliferation and migration, intracellular expression or extracellular deposition of collagen I (COL1), collagen III (COL3), and fibronectin. Endoplasmic reticulum (ER) stress response and mitochondrial function have been implicated in asthma. We investigated whether GDNF regulates these aspects in human ASM. We found that GDNF treatment did not affect ER stress protein expression in normal or asthmatic cells. However, GDNF treatment impaired mitochondrial morphology in ASM but without significant effects on mitochondrial respiration. Thus, it is likely that in vivo effects of GDNF on airway remodeling per se involve cell types other than those on ASM, and thus ASM may serve more as a source of GDNF rather than a target.<b>NEW & NOTEWORTHY</b> Our previous study suggests that glial-derived neurotrophic factor (GDNF) is involved in allergen-induced airway hyperreactivity and remodeling in vivo. Here, we show that GDNF has no direct effects in remodeling of human airway smooth muscle (ASM) but GDNF dysregulates mitochondrial morphology in human ASM in the context of asthma.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L684-L693"},"PeriodicalIF":4.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11563586/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142339328","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":"Microbiome modifications by steroids during viral exacerbation of asthma and in healthy mice.","authors":"Kazuma Yagi, Alexander D Ethridge, Nicole R Falkowski, Yvonne J Huang, Srikanth Elesela, Gary B Huffnagle, Nicholas W Lukacs, Wendy Fonseca, Nobuhiro Asai","doi":"10.1152/ajplung.00040.2024","DOIUrl":"10.1152/ajplung.00040.2024","url":null,"abstract":"<p><p>In the present studies, the assessment of how viral exacerbation of asthmatic responses with and without pulmonary steroid treatment alters the microbiome in conjunction with immune responses presents striking data. The overall findings identify that although steroid treatment of allergic animals diminished the severity of the respiratory syncytial virus (RSV)-induced exacerbation of airway function and mucus hypersecretion, there were local increases in IL-17 expression. Analysis of the lung and gut microbiome suggested that there are differences in RSV exacerbation that are further altered by fluticasone (FLUT) treatment. Using metagenomic inference software, PICRUSt2, we were able to predict that the metabolite profile produced by the changed gut microbiome was significantly different with multiple metabolic pathways and associated with specific treatments with or without FLUT. Importantly, measuring plasma metabolites in an unbiased manner, our data indicate that there are significant changes associated with chronic allergen exposure, RSV exacerbation, and FLUT treatment that are reflective of responses to the disease and treatment. In addition, the changes in metabolites appeared to have contributions from both host and microbial pathways. To understand if airway steroids on their own altered lung and gut microbiome along with host responses to RSV infection, naïve animals were treated with lung FLUT before RSV infection. The naïve animals treated with FLUT before RSV infection demonstrated enhanced disease that corresponded to an altered microbiome and the related PICRUSt2 metagenomic inference analysis. Altogether, these findings set the foundation for identifying important correlations of severe viral exacerbated allergic disease with microbiome changes and the relationship of host metabolome with a potential for early life pulmonary steroid influence on subsequent viral-induced disease.<b>NEW & NOTEWORTHY</b> These studies outline a novel finding that airway treatment with fluticasone, a commonly used inhaled steroid, has significant effects on not only the local lung environment but also on the mucosal microbiome, which may have significant disease implications. The findings further provide data to support that pulmonary viral exacerbations of asthma with or without steroid treatment alter the lung and gut microbiome, which have an impact on the circulating metabolome that likely alters the trajectory of disease progression.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L646-L660"},"PeriodicalIF":4.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11560076/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142003399","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":"Enhanced lung endothelial glycolysis is implicated in the development of severe pulmonary hypertension in type 2 diabetes.","authors":"Qiuyu Zheng, Jody Tori O Cabrera, Atsumi Tsuji-Hosokawa, Francisco J Ramirez, Hua Linda Cai, Jason X-J Yuan, Jian Wang, Ayako Makino","doi":"10.1152/ajplung.00305.2023","DOIUrl":"https://doi.org/10.1152/ajplung.00305.2023","url":null,"abstract":"<p><p>Metabolic abnormalities in pulmonary endothelial cells are implicated in pulmonary hypertension (PH) while increasing evidence shows the influence of diabetes on progressing PH. In this study, we examined the effect of type 2 diabetes on hypoxia-induced PH and investigated its molecular mechanisms using hypoxia-induced diabetic male mice. Chronic hypoxia led to a more severe PH in type 2 diabetic mice than in control mice. Next, we compared gene expression patterns in isolated pulmonary endothelial cells (MPECs) from control mice in normoxia (CN), diabetic mice in normoxia (DN), control mice exposed to hypoxia (CH), and diabetic mice exposed to hypoxia (DH). The results showed that expression levels of 27 mRNAs, out of 92 mRNAs, were significantly different among the four groups. Two glycolysis-related proteins, GAPDH and HK2, were increased in MPECs of DH mice compared to those in DN or CH mice. In addition, the levels of pyruvate and lactate (glycolysis end products) were significantly increased in MPECs of DH mice, but not in CH mice, compared to MPECs of CN mice. Augmentation of glycolysis by terazosin exacerbated hypoxia-induced PH in CH mice but not in DH mice. On the contrary, inhibiting GAPDH (a key enzyme of the glycolytic pathway) by koningic acid ameliorated hypoxia-induced PH in DH mice but had no effect in CH mice. These data suggest that enhanced glycolysis in diabetic mice is involved in severe hypoxia-induced PH, and glycolysis inhibition is a potential target to reduce the severe progression of PH in diabetic patients.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142492919","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 pontine Kölliker-Fuse nucleus is important for reduced postinspiratory airflow elicited by stimulation of the ventral respiratory parafacial region.","authors":"Karine C Flor, Octavio A C Maia, Ana C Takakura, Thiago S Moreira","doi":"10.1152/ajplung.00155.2024","DOIUrl":"10.1152/ajplung.00155.2024","url":null,"abstract":"<p><p>Considering that the retrotrapezoid nucleus/respiratory parafacial region (RTN/pFRG) would be an important center in the central nervous system involved in the maintenance and modulation of respiratory activity, we hypothesized that neurons in this nucleus would also be involved in the postinspiratory (post-I) phase of the respiratory cycle through a connection with the pontine Kölliker-Fuse (KF) region. Here, we performed pharmacogenetic manipulation (AAV-hM3D(Gq)-mCherry or AAV-hM4D(Gi)-mCherry) in VGlut2-cre, Ai6 conscious mice to evaluate breathing parameters through whole body plethysmography under baseline conditions (normoxia: [Formula: see text] = 0.21) or under hypercapnia or hypoxia challenges ([Formula: see text] = 0.07 or [Formula: see text] = 0.08). Under normoxia, selective stimulation of RTN/pFRG resulted in a smaller increase in V̇e (1,272 ± 102.5, vs. RTN/pFRG stimulation: 1,878 ± 122.1 mL/kg/min), due to a smaller increase in V_T (5.4 ± 0.35, vs. RTN/pFRG stimulation: 7.77 ± 0.21 mL/kg) without changing <i>f</i>_R in a condition of KF inhibition. However, inhibition of the VGlut2 neurons in the KF did affect the <i>T</i>_E1 produced by selective activation of RTN/pFRG (119.9 ± 2.53, vs. RTN/pFRG stimulation: 104 ± 2.46 ms). Both the hypercapnia and hypoxia ventilatory response were reduced after inhibition of VGlut2-expressing KF neurons. Therefore, consistent with anatomical projections RTN/pFRG neurons regulate lung ventilation by controlling all aspects of breathing, i.e., breathing frequency, inspiration, postinspiration, and active expiration. All the modulation seems to be dependent on the integrity of the glutamatergic neurons in the KF region.<b>NEW & NOTEWORTHY</b> Our research reveals specific roles and interactions between the retrotrapezoid nucleus/respiratory parafacial region (RTN/pFRG) and the pontine Kölliker-Fuse (KF) region in controlling respiratory phases. RTN/pFRG neurons are key in regulating all aspects of breathing, including frequency, inspiration, postinspiration, and active expiration. This regulation depends on the functional integrity of glutamatergic neurons in the KF region, aligning with anatomical projections.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L452-L463"},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141892698","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":"Mucociliary clearance is impaired in small airways of cystic fibrosis pigs.","authors":"Carley G Stewart, Brieanna M Hilkin, Nicholas D Gansemer, Ryan J Adam, David W Dick, John J Sunderland, David A Stoltz, Joseph Zabner, Mahmoud H Abou Alaiwa","doi":"10.1152/ajplung.00010.2024","DOIUrl":"10.1152/ajplung.00010.2024","url":null,"abstract":"<p><p>Cystic fibrosis (CF) is a genetic disorder characterized by recurrent airway infections, inflammation, impaired mucociliary clearance, and progressive decline in lung function. The disease may start in the small airways; however, this is difficult to prove due to the limited accessibility of the small airways with the current single-photon mucociliary clearance assay. Here, we developed a dynamic positron emission tomography assay with high spatial and temporal resolution. We tested that mucociliary clearance is abnormal in the small airways of newborn cystic fibrosis pigs. Clearance of [⁶⁸Ga]-tagged macroaggregated albumin from small airways started immediately after delivery and continued for the duration of the study. Initial clearance was fast but slowed down a few minutes after delivery. Cystic fibrosis pigs' small airways cleared significantly less than non-CF pigs' small airways (non-CF 25.1 ± 3.1% vs. CF 14.6 ± 0.1%). Stimulation of the cystic fibrosis airways with the purinergic secretagogue uridine-5'-triphosphate (UTP) further impaired clearance (non-CF with UTP 20.9 ± 0.3% vs. CF with UTP 13.0 ± 1.8%). None of the cystic fibrosis pigs treated with UTP (<i>n</i> = 6) cleared more than 20% of the delivered dose. These data indicate that mucociliary clearance in the small airways is fast and can easily be missed if the assay is not sensitive enough. The data also indicate that mucociliary clearance is impaired in the small airways of cystic fibrosis pigs. This defect is exacerbated by stimulation of mucus secretions with purinergic agonists.<b>NEW & NOTEWORTHY</b> We developed a novel positron emission tomography scan assay with unprecedented temporal and spatial resolution to measure mucociliary clearance in the small airways. We proved a long-standing but unproven assertion that mucociliary clearance is inherently abnormal in the small airways of newborn cystic fibrosis piglets that are otherwise free of infection or inflammation. This technique can be easily extended to other airway diseases such as asthma, idiopathic pulmonary fibrosis, or chronic obstructive pulmonary disease.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":" ","pages":"L415-L422"},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11482522/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141892696","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}