Pub Date : 2024-10-01Epub Date: 2024-08-06DOI: 10.1152/ajplung.00010.2024
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
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 (n = 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.NEW & NOTEWORTHY 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.
囊性纤维化是一种遗传性疾病,其特点是气道反复感染、炎症、粘液纤毛清除能力受损以及肺功能逐渐下降。这种疾病可能从小气道开始;然而,由于目前的单光子粘液纤毛清除测定对小气道的可及性有限,因此很难证明这一点。在这里,我们开发了一种具有高空间和时间分辨率的动态正电子发射断层扫描检测方法。我们测试了新生囊性纤维化猪小气道中的粘液纤毛清除率是否异常。小气道中[68Ga]标记的大聚集白蛋白的清除在分娩后立即开始,并持续整个研究过程。最初的清除速度很快,但在分娩几分钟后就减慢了。囊性纤维化猪小气道的清除率明显低于非囊性纤维化猪小气道(非囊性纤维化猪 25.1±3.1% vs. 囊性纤维化猪 14.6±0.1%)。用嘌呤能分泌物UTP刺激囊性纤维化气道会进一步降低清除率(使用UTP的非囊性纤维化猪为20.9±0.3%,使用UTP的囊性纤维化猪为13.0±1.8%)。使用UTP治疗的囊性纤维化猪(N = 6)的清除率均未超过给药剂量的20%。这些数据表明,小气道中的粘膜纤毛清除速度很快,如果检测灵敏度不够,很容易被漏掉。数据还表明,囊性纤维化猪小气道中的粘液纤毛清除能力受损。嘌呤能激动剂刺激粘液分泌会加剧这种缺陷。
{"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 [<sup>68</sup>Ga]-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":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","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":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01Epub Date: 2024-08-06DOI: 10.1152/ajplung.00155.2024
Karine C Flor, Octavio A C Maia, Ana C Takakura, Thiago S Moreira
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 VT (5.4 ± 0.35, vs. RTN/pFRG stimulation: 7.77 ± 0.21 mL/kg) without changing fR in a condition of KF inhibition. However, inhibition of the VGlut2 neurons in the KF did affect the TE1 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.NEW & NOTEWORTHY 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.
{"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<sub>T</sub> (5.4 ± 0.35, vs. RTN/pFRG stimulation: 7.77 ± 0.21 mL/kg) without changing <i>f</i><sub>R</sub> in a condition of KF inhibition. However, inhibition of the VGlut2 neurons in the KF did affect the <i>T</i><sub>E1</sub> 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":null,"pages":null},"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}
Pub Date : 2024-10-01Epub Date: 2024-08-06DOI: 10.1152/ajplung.00151.2024
Enrique Alfaro, Elena Díaz-García, Sara García-Tovar, Raúl Galera, Raquel Casitas, Elisabet Martínez-Cerón, María Torres-Vargas, José M Padilla, Cristina López-Fernández, Paula Pérez-Moreno, Francisco García-Río, Carolina Cubillos-Zapata
Chronic obstructive pulmonary disease (COPD) is regarded as an accelerated-age disease in which chronic inflammation, maladaptive immune responses, and senescence cell burden coexist. Accordingly, cellular senescence has emerged as a potential mechanism involved in COPD pathophysiology. In this study, 25 stable patients with COPD underwent a daily physical activity promotion program for 6 mo. We reported that increase of physical activity was related to a reduction of the senescent cell burden in circulating lymphocytes of patients with COPD. Senescent T-lymphocyte population, characterized by absence of surface expression of CD28, was reduced after physical activity intervention, and the reduction was associated to the increase of physical activity level. In addition, the mRNA expression of cyclin-dependent kinase inhibitors, a hallmark of cell senescence, was reduced and, in accordance, the proliferative capacity of lymphocytes was improved postintervention. Moreover, we observed an increase in functionality in T cells from patients after intervention, including improved markers of activation, enhanced cytotoxicity, and altered cytokine secretions in response to viral challenge. Lastly, physical activity intervention reduced the potential of lymphocytes' secretome to induce senescence in human primary fibroblasts. In conclusion, our study provides, for the first time, evidence of the potential of physical activity intervention in patients with COPD to reduce the senescent burden in circulating immune cells.NEW & NOTEWORTHY For the first time, we identified in patients with COPD a relation between physical activity intervention with respiratory function improvement and cellular senescence burden in lymphocytes that improved the T cell functionality and proliferative capacity of patients. In addition, our experiments highlight the possible impact of T-cell senescence in other cell types which could be related to some of the clinical lung complications observed in COPD.
慢性阻塞性肺病(COPD)被认为是一种加速衰老的疾病,其中慢性炎症、不适应性免疫反应和衰老细胞负担并存。因此,细胞衰老已成为慢性阻塞性肺病病理生理学的一个潜在机制。在这项研究中,25 名病情稳定的慢性阻塞性肺病患者接受了为期 6 个月的日常体育锻炼促进计划。我们发现,体力活动的增加与慢性阻塞性肺病患者循环淋巴细胞中衰老细胞负担的减少有关。体力活动干预后,以表面不表达 CD28 为特征的衰老 T 淋巴细胞数量减少了,而且这种减少与体力活动水平的增加有关。此外,作为细胞衰老标志的细胞周期蛋白依赖性激酶抑制剂的 mRNA 表达量也有所减少,因此,干预后淋巴细胞的增殖能力也有所提高。此外,我们还观察到患者的 T 细胞在干预后功能增强,包括活化标志物改善、细胞毒性增强以及细胞因子分泌对病毒挑战的反应发生改变。最后,体育锻炼干预降低了淋巴细胞分泌组诱导人类原代成纤维细胞衰老的潜力。总之,我们的研究首次提供了证据,证明对慢性阻塞性肺病患者进行体育锻炼干预有可能减少循环免疫细胞的衰老负担。
{"title":"Effect of physical activity in lymphocytes senescence burden in patients with COPD.","authors":"Enrique Alfaro, Elena Díaz-García, Sara García-Tovar, Raúl Galera, Raquel Casitas, Elisabet Martínez-Cerón, María Torres-Vargas, José M Padilla, Cristina López-Fernández, Paula Pérez-Moreno, Francisco García-Río, Carolina Cubillos-Zapata","doi":"10.1152/ajplung.00151.2024","DOIUrl":"10.1152/ajplung.00151.2024","url":null,"abstract":"<p><p>Chronic obstructive pulmonary disease (COPD) is regarded as an accelerated-age disease in which chronic inflammation, maladaptive immune responses, and senescence cell burden coexist. Accordingly, cellular senescence has emerged as a potential mechanism involved in COPD pathophysiology. In this study, 25 stable patients with COPD underwent a daily physical activity promotion program for 6 mo. We reported that increase of physical activity was related to a reduction of the senescent cell burden in circulating lymphocytes of patients with COPD. Senescent T-lymphocyte population, characterized by absence of surface expression of CD28, was reduced after physical activity intervention, and the reduction was associated to the increase of physical activity level. In addition, the mRNA expression of cyclin-dependent kinase inhibitors, a hallmark of cell senescence, was reduced and, in accordance, the proliferative capacity of lymphocytes was improved postintervention. Moreover, we observed an increase in functionality in T cells from patients after intervention, including improved markers of activation, enhanced cytotoxicity, and altered cytokine secretions in response to viral challenge. Lastly, physical activity intervention reduced the potential of lymphocytes' secretome to induce senescence in human primary fibroblasts. In conclusion, our study provides, for the first time, evidence of the potential of physical activity intervention in patients with COPD to reduce the senescent burden in circulating immune cells.<b>NEW & NOTEWORTHY</b> For the first time, we identified in patients with COPD a relation between physical activity intervention with respiratory function improvement and cellular senescence burden in lymphocytes that improved the T cell functionality and proliferative capacity of patients. In addition, our experiments highlight the possible impact of T-cell senescence in other cell types which could be related to some of the clinical lung complications observed in COPD.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141892694","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}
Pub Date : 2024-10-01Epub Date: 2024-07-16DOI: 10.1152/ajplung.00279.2023
Guiying Cui, Dina A Moustafa, Shilin Zhao, Analia Vazquez Cegla, James T Lyles, Joanna B Goldberg, Joshua D Chandler, Nael A McCarty
Cystic fibrosis-related diabetes (CFRD), the most common comorbidity in cystic fibrosis (CF), leads to increased mortality by accelerating the decline in lung function. Scnn1b-Tg transgenic mice overexpressing the epithelial sodium channel β subunit exhibit spontaneous CF-like lung disease, including airway mucus obstruction and chronic inflammation. Here, we established a chronic CFRD-like model using Scnn1b-Tg mice made diabetic by injection of streptozotocin (STZ). In Ussing chamber recordings of the trachea, Scnn1b-Tg mice exhibited larger amiloride-sensitive currents and forskolin-activated currents, without a difference in adenosine triphosphate (ATP)-activated currents compared with wild-type (WT) littermates. Both diabetic WT (WT-D) and diabetic Scnn1b-Tg (Scnn1b-Tg-D) mice on the same genetic background exhibited substantially elevated blood glucose at 8 wk; glucose levels also were elevated in bronchoalveolar lavage fluid (BALF). Bulk lung RNA-seq data showed significant differences between WT-D and Scnn1b-Tg-D mice. Neutrophil counts in BALF were substantially increased in Scnn1b-Tg-D lungs compared with controls (Scnn1b-Tg-con) and compared with WT-D lungs. Lung histology data showed enhanced parenchymal destruction, alveolar wall thickening, and neutrophilic infiltration in Scnn1b-Tg-D mice compared with WT-D mice, consistent with the development of a spontaneous lung infection. We intranasally administered Pseudomonas aeruginosa to induce lung infection in these mice for 24 h, which led to severe lung leukocytic infiltration and an increase in pro-inflammatory cytokine levels in the BALF. In summary, we established a chronic CFRD-like lung mouse model using the Scnn1b-Tg mice. The model can be used for future studies toward understanding the mechanisms underlying the lung pathophysiology associated with CFRD and developing novel therapeutics.NEW & NOTEWORTHY We established a chronic CFRD-like mouse model using the Scnn1b-Tg transgenic mice overexpressing the epithelial sodium channel β subunit made diabetic by injection of streptozotocin. The results underscore the urgent need to develop novel therapeutics for CF lung disease.
{"title":"Chronic hyperglycemia aggravates lung function in a <i>Scnn1b</i>-Tg murine model.","authors":"Guiying Cui, Dina A Moustafa, Shilin Zhao, Analia Vazquez Cegla, James T Lyles, Joanna B Goldberg, Joshua D Chandler, Nael A McCarty","doi":"10.1152/ajplung.00279.2023","DOIUrl":"10.1152/ajplung.00279.2023","url":null,"abstract":"<p><p>Cystic fibrosis-related diabetes (CFRD), the most common comorbidity in cystic fibrosis (CF), leads to increased mortality by accelerating the decline in lung function. <i>Scnn1b-</i>Tg transgenic mice overexpressing the epithelial sodium channel β subunit exhibit spontaneous CF-like lung disease, including airway mucus obstruction and chronic inflammation. Here, we established a chronic CFRD-like model using <i>Scnn1b-</i>Tg mice made diabetic by injection of streptozotocin (STZ). In Ussing chamber recordings of the trachea, <i>Scnn1b-</i>Tg mice exhibited larger amiloride-sensitive currents and forskolin-activated currents, without a difference in adenosine triphosphate (ATP)-activated currents compared with wild-type (WT) littermates. Both diabetic WT (WT-D) and diabetic <i>Scnn1b-</i>Tg (<i>Scnn1b</i>-Tg-D) mice on the same genetic background exhibited substantially elevated blood glucose at 8 wk; glucose levels also were elevated in bronchoalveolar lavage fluid (BALF). Bulk lung RNA-seq data showed significant differences between WT-D and <i>Scnn1b</i>-Tg-D mice. Neutrophil counts in BALF were substantially increased in <i>Scnn1b-</i>Tg-D lungs compared with controls (<i>Scnn1b</i>-Tg-con) and compared with WT-D lungs. Lung histology data showed enhanced parenchymal destruction, alveolar wall thickening, and neutrophilic infiltration in <i>Scnn1b-</i>Tg-D mice compared with WT-D mice, consistent with the development of a spontaneous lung infection. We intranasally administered <i>Pseudomonas aeruginosa</i> to induce lung infection in these mice for 24 h, which led to severe lung leukocytic infiltration and an increase in pro-inflammatory cytokine levels in the BALF. In summary, we established a chronic CFRD-like lung mouse model using the <i>Scnn1b</i>-Tg mice. The model can be used for future studies toward understanding the mechanisms underlying the lung pathophysiology associated with CFRD and developing novel therapeutics.<b>NEW & NOTEWORTHY</b> We established a chronic CFRD-like mouse model using the <i>Scnn1b</i>-Tg transgenic mice overexpressing the epithelial sodium channel β subunit made diabetic by injection of streptozotocin. The results underscore the urgent need to develop novel therapeutics for CF lung disease.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141619054","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}
Pub Date : 2024-10-01DOI: 10.1152/ajplung.00304.2024
Larissa A Shimoda, Cristina M Alvira, Julie A Bastarache, Rodney D Britt, Wolfgang M Kuebler, Thiago S Moreira, Eric P Schmidt
{"title":"New Faces: Introducing the newest Editorial Board Fellows of the <i>American Journal of Physiology-Lung Cellular and Molecular Physiology</i>.","authors":"Larissa A Shimoda, Cristina M Alvira, Julie A Bastarache, Rodney D Britt, Wolfgang M Kuebler, Thiago S Moreira, Eric P Schmidt","doi":"10.1152/ajplung.00304.2024","DOIUrl":"https://doi.org/10.1152/ajplung.00304.2024","url":null,"abstract":"","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142339337","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}
Pub Date : 2024-10-01Epub Date: 2024-08-13DOI: 10.1152/ajplung.00185.2024
Mark P Murphy, Marina Zieger, Michael Henry, Paula Meleady, Christian Mueller, Noel G McElvaney, Emer P Reeves
Elastin is an extracellular matrix protein (ECM) that supports elasticity of the lung, and in patients with chronic obstructive pulmonary disease (COPD) and emphysema, the structural changes that reduce the amount of elastic recoil, lead to loss of pulmonary function. We recently demonstrated that elastin is a target of peptidyl arginine deiminase (PAD) enzyme-induced citrullination, thereby leading to enhanced susceptibility of this ECM protein to proteolysis. This study aimed to investigate the impact of PAD activity in vivo and furthermore assessed whether pharmacological inhibition of PAD activity protects against pulmonary emphysema. Using a Serpina1a-e knockout mouse model, previously shown to develop inflammation-mediated emphysema, we validated the involvement of PADs in airway disease. In line with emphysema development, intratracheal administration of lipopolysaccharide in combination with PADs provoked significant airspace enlargement (P < 0.001) and diminished lung function, including loss of lung tissue elastance (P = 0.0217) and increases in lung volumes (P = 0.0463). Intraperitoneal treatment of mice with the PAD inhibitor, BB-Cl-amidine, prevented PAD/LPS-mediated lung function decline and emphysema and reduced levels of citrullinated airway elastin (P = 0.0199). These results provide evidence for the impact of PADs on lung function decline, indicating promising potential for the future development of PAD-based therapeutics for preserving lung function in patients with COPD.NEW & NOTEWORTHY This study provides evidence for the impact of peptidyl arginine deiminase (PAD) enzymes on lung function decline, indicating promising potential for the future development of PAD-based therapeutics for preserving lung function in patients with COPD.
弹性蛋白是一种细胞外基质蛋白(ECM),它支撑着肺部的弹性,在慢性阻塞性肺病(COPD)和肺气肿患者中,结构性变化会减少弹性反冲力,导致肺功能丧失。我们最近证实,弹性蛋白是肽酰精氨酸脱氨酶(PAD)诱导的瓜氨酸化作用的靶标,从而导致这种 ECM 蛋白更易被蛋白水解。本研究旨在调查 PAD 活性在体内的影响,并进一步评估药物抑制 PAD 活性是否能预防肺气肿。我们利用先前被证明会发生炎症介导的肺气肿的 Serpina1a-e 基因敲除小鼠模型,验证了 PAD 在气道疾病中的参与作用。与肺气肿的发展相一致,气管内给予脂多糖和 PADs 会导致气道显著扩大(P < 0.001)和肺功能减退,包括肺组织弹性损失(P = 0.0217)和肺体积增大(P = 0.0463)。用 PAD 抑制剂 BB-Cl-amidine 对小鼠进行腹腔治疗可防止 PAD/LPS 介导的肺功能下降和肺气肿,并降低瓜氨酸化气道弹性蛋白的水平(P = 0.0199)。这些结果为 PAD 对肺功能下降的影响提供了证据,为未来开发基于 PAD 的治疗方法以保护慢性阻塞性肺病患者的肺功能提供了广阔的前景。
{"title":"Citrullination, a novel posttranslational modification of elastin, is involved in COPD pathogenesis.","authors":"Mark P Murphy, Marina Zieger, Michael Henry, Paula Meleady, Christian Mueller, Noel G McElvaney, Emer P Reeves","doi":"10.1152/ajplung.00185.2024","DOIUrl":"10.1152/ajplung.00185.2024","url":null,"abstract":"<p><p>Elastin is an extracellular matrix protein (ECM) that supports elasticity of the lung, and in patients with chronic obstructive pulmonary disease (COPD) and emphysema, the structural changes that reduce the amount of elastic recoil, lead to loss of pulmonary function. We recently demonstrated that elastin is a target of peptidyl arginine deiminase (PAD) enzyme-induced citrullination, thereby leading to enhanced susceptibility of this ECM protein to proteolysis. This study aimed to investigate the impact of PAD activity in vivo and furthermore assessed whether pharmacological inhibition of PAD activity protects against pulmonary emphysema. Using a <i>Serpina1a-e</i> knockout mouse model, previously shown to develop inflammation-mediated emphysema, we validated the involvement of PADs in airway disease. In line with emphysema development, intratracheal administration of lipopolysaccharide in combination with PADs provoked significant airspace enlargement (<i>P</i> < 0.001) and diminished lung function, including loss of lung tissue elastance (<i>P</i> = 0.0217) and increases in lung volumes (<i>P</i> = 0.0463). Intraperitoneal treatment of mice with the PAD inhibitor, BB-Cl-amidine, prevented PAD/LPS-mediated lung function decline and emphysema and reduced levels of citrullinated airway elastin (<i>P</i> = 0.0199). These results provide evidence for the impact of PADs on lung function decline, indicating promising potential for the future development of PAD-based therapeutics for preserving lung function in patients with COPD.<b>NEW & NOTEWORTHY</b> This study provides evidence for the impact of peptidyl arginine deiminase (PAD) enzymes on lung function decline, indicating promising potential for the future development of PAD-based therapeutics for preserving lung function in patients with COPD.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974845","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}
Pub Date : 2024-10-01Epub Date: 2024-08-27DOI: 10.1152/ajplung.00149.2023
J Kelley Bentley, Jordan E Kreger, Haley A Breckenridge, Shilpi Singh, Jing Lei, Yiran Li, Susan C Baker, Carey N Lumeng, Marc B Hershenson
Human coronavirus (HCoV)-NL63 causes respiratory tract infections in humans and uses angiotensin-converting enzyme 2 (ACE2) as a receptor. We sought to establish a mouse model of HCoV-NL63 and determine whether prior rhinovirus (RV)-A1B infection affected HCoV-NL63 replication. HCoV-NL63 was propagated in LLC-MK2 cells expressing human ACE2. RV-A1B was grown in HeLa-H1 cells. C57BL6/J or transgenic mice expressing human ACE2 were infected intranasally with sham LLC-MK2 cell supernatant or 1 × 105 tissue culture infectious dose (TCID50) units HCoV-NL63. Wild-type mice were infected with 1 × 106 plaque-forming units (PFU) RV-A1B. Lungs were assessed for vRNA, bronchoalveolar lavage (BAL) cells, histology, HCoV-NL63 nonstructural protein 3 (nsp3), and host gene expression by next-generation sequencing and qPCR. To evaluate sequential infections, mice were infected with RV-A1B followed by HCoV-NL63 infection 4 days later. We report that hACE2 mice infected with HCoV-NL63 showed evidence of replicative infection with increased levels of vRNA, BAL neutrophils and lymphocytes, peribronchial and perivascular infiltrates, and expression of nsp3. Viral replication peaked 3 days after infection and inflammation persisted 6 days after infection. HCoV-NL63-infected hACE2 mice showed increased mRNA expression of IFNs, IFN-stimulated proteins, and proinflammatory cytokines. Infection with RV-A1B 4 days before HCoV-NL63 significantly decreased both HCoV-NL63 vRNA levels and airway inflammation. Mice infected with RV-A1B prior to HCoV-NL63 showed increased expression of antiviral proteins compared with sham-treated mice. In conclusion, we established a mouse model of HCoV-NL63 replicative infection characterized by relatively persistent viral replication and inflammation. Prior infection with RV-A1B reduced HCoV-NL63 replication and airway inflammation, indicative of viral interference.NEW & NOTEWORTHY We describe a mouse model of human coronavirus (HCoV) infection. Infection of transgenic mice expressing human angiotensin-converting enzyme 2 (ACE2) with HCoV-NL63 produced a replicative infection with peribronchial inflammation and nonstructural protein 3 expression. Mice infected with RV-A1B 4 days before HCoV-NL63 showed decreased HCoV-NL63 replication and airway inflammation and increased expression of antiviral proteins compared with sham-treated mice. This research may shed light on human coronavirus infections, viral interference, and viral-induced asthma exacerbations.
{"title":"Developing a mouse model of human coronavirus NL63 infection: comparison with rhinovirus-A1B and effects of prior rhinovirus infection.","authors":"J Kelley Bentley, Jordan E Kreger, Haley A Breckenridge, Shilpi Singh, Jing Lei, Yiran Li, Susan C Baker, Carey N Lumeng, Marc B Hershenson","doi":"10.1152/ajplung.00149.2023","DOIUrl":"10.1152/ajplung.00149.2023","url":null,"abstract":"<p><p>Human coronavirus (HCoV)-NL63 causes respiratory tract infections in humans and uses angiotensin-converting enzyme 2 (ACE2) as a receptor. We sought to establish a mouse model of HCoV-NL63 and determine whether prior rhinovirus (RV)-A1B infection affected HCoV-NL63 replication. HCoV-NL63 was propagated in LLC-MK2 cells expressing human ACE2. RV-A1B was grown in HeLa-H1 cells. C57BL6/J or transgenic mice expressing human ACE2 were infected intranasally with sham LLC-MK2 cell supernatant or 1 × 10<sup>5</sup> tissue culture infectious dose (TCID<sub>50</sub>) units HCoV-NL63. Wild-type mice were infected with 1 × 10<sup>6</sup> plaque-forming units (PFU) RV-A1B. Lungs were assessed for vRNA, bronchoalveolar lavage (BAL) cells, histology, HCoV-NL63 nonstructural protein 3 (nsp3), and host gene expression by next-generation sequencing and qPCR. To evaluate sequential infections, mice were infected with RV-A1B followed by HCoV-NL63 infection 4 days later. We report that hACE2 mice infected with HCoV-NL63 showed evidence of replicative infection with increased levels of vRNA, BAL neutrophils and lymphocytes, peribronchial and perivascular infiltrates, and expression of nsp3. Viral replication peaked 3 days after infection and inflammation persisted 6 days after infection. HCoV-NL63-infected hACE2 mice showed increased mRNA expression of IFNs, IFN-stimulated proteins, and proinflammatory cytokines. Infection with RV-A1B 4 days before HCoV-NL63 significantly decreased both HCoV-NL63 vRNA levels and airway inflammation. Mice infected with RV-A1B prior to HCoV-NL63 showed increased expression of antiviral proteins compared with sham-treated mice. In conclusion, we established a mouse model of HCoV-NL63 replicative infection characterized by relatively persistent viral replication and inflammation. Prior infection with RV-A1B reduced HCoV-NL63 replication and airway inflammation, indicative of viral interference.<b>NEW & NOTEWORTHY</b> We describe a mouse model of human coronavirus (HCoV) infection. Infection of transgenic mice expressing human angiotensin-converting enzyme 2 (ACE2) with HCoV-NL63 produced a replicative infection with peribronchial inflammation and nonstructural protein 3 expression. Mice infected with RV-A1B 4 days before HCoV-NL63 showed decreased HCoV-NL63 replication and airway inflammation and increased expression of antiviral proteins compared with sham-treated mice. This research may shed light on human coronavirus infections, viral interference, and viral-induced asthma exacerbations.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142071779","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}
Pub Date : 2024-10-01DOI: 10.1152/ajplung.00184.2023
Mada Ghanem, Aurélien Justet, Madeleine Jaillet, Eirini Vasarmidi, Tiara Boghanim, Mouna Hachem, Aurelie Vadel, Audrey Joannes, Pierre Mordant, Agshin Balayev, Taylor Adams, Hervé Mal, Aurélie Cazes, Nicolas Poté, Arnaud Mailleux, Bruno Crestani
Introduction IPF is a devastating lung disease with limited therapeutic options. FGFR4 is a known receptor for several paracrine Fibroblast growth factors (FGFs). FGFR4 is also the main receptor for FGF19, an endocrine FGF that was demonstrated by our group to have anti-fibrotic properties in the lung. We aimed to determine whether FGFR4 could modulate pulmonary fibrogenesis. Methods We assessed FGFR4 mRNA and protein levels in IPF and control lungs. In vitro, we determined the effect of TGF-b, Endothelin-1 and PDGF on FGFR4 expression in human lung fibroblasts. We determined the effect FGFR4 inhibition, using a specific pharmacological inhibitor (FGF401), or genetic deletion in murine embryonic fibroblasts (MEFs) on TGF-b-induced myofibroblastic differentiation. In vivo, we evaluated the development of bleomycin-induced lung fibrosis in Fgfr4-deficient (Fgfr4-/-) mice compared to Wild Type littermates (WT), and after FGF401 treatment in WT mice compared to a control group receiving the solvent only. Results FGFR4 was decreased in IPF lungs as compared to control lungs, at mRNA and protein levels. In vitro, FGFR4 was downregulated after treatment by TGF- β, Endothelin-1 and PDGF. In vitro, FGFR4 inhibition by FGF401 prevented TGF-b1-induced collagen and ACTA2 increase in lung fibroblasts. Similar results were observed in Fgfr4-/- MEFs. In vivo, FGFR4 genetic deficiency or FGFR4 pharmacological inhibition did not modulate bleomycin-induced pulmonary fibrosis. Conclusion Our data suggest that FGFR4 exerts pro-fibrotic properties by enhancing TGF- β signaling in vitro. However, the inhibition of FGFR4 is not sufficient to prevent the development of pulmonary fibrosis in vivo.
{"title":"Identification of FGFR4 as a regulator of myofibroblast differentiation in Pulmonary Fibrosis.","authors":"Mada Ghanem, Aurélien Justet, Madeleine Jaillet, Eirini Vasarmidi, Tiara Boghanim, Mouna Hachem, Aurelie Vadel, Audrey Joannes, Pierre Mordant, Agshin Balayev, Taylor Adams, Hervé Mal, Aurélie Cazes, Nicolas Poté, Arnaud Mailleux, Bruno Crestani","doi":"10.1152/ajplung.00184.2023","DOIUrl":"https://doi.org/10.1152/ajplung.00184.2023","url":null,"abstract":"<p><p>Introduction IPF is a devastating lung disease with limited therapeutic options. FGFR4 is a known receptor for several paracrine Fibroblast growth factors (FGFs). FGFR4 is also the main receptor for FGF19, an endocrine FGF that was demonstrated by our group to have anti-fibrotic properties in the lung. We aimed to determine whether FGFR4 could modulate pulmonary fibrogenesis. Methods We assessed FGFR4 mRNA and protein levels in IPF and control lungs. In vitro, we determined the effect of TGF-b, Endothelin-1 and PDGF on FGFR4 expression in human lung fibroblasts. We determined the effect FGFR4 inhibition, using a specific pharmacological inhibitor (FGF401), or genetic deletion in murine embryonic fibroblasts (MEFs) on TGF-b-induced myofibroblastic differentiation. In vivo, we evaluated the development of bleomycin-induced lung fibrosis in <i>Fgfr4</i>-deficient (<i>Fgfr4</i>-/-) mice compared to Wild Type littermates (WT), and after FGF401 treatment in WT mice compared to a control group receiving the solvent only. Results FGFR4 was decreased in IPF lungs as compared to control lungs, at mRNA and protein levels. In vitro, FGFR4 was downregulated after treatment by TGF- β, Endothelin-1 and PDGF. In vitro, FGFR4 inhibition by FGF401 prevented TGF-b1-induced collagen and ACTA2 increase in lung fibroblasts. Similar results were observed in <i>Fgfr4</i>-/- MEFs. In vivo, FGFR4 genetic deficiency or FGFR4 pharmacological inhibition did not modulate bleomycin-induced pulmonary fibrosis. Conclusion Our data suggest that FGFR4 exerts pro-fibrotic properties by enhancing TGF- β signaling in vitro. However, the inhibition of FGFR4 is not sufficient to prevent the development of pulmonary fibrosis in vivo.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142339331","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}
Pub Date : 2024-10-01Epub Date: 2024-08-27DOI: 10.1152/ajplung.00356.2023
Mengning Zheng, Yang Yao, Niyati A Borkar, Michael A Thompson, Emily Zhang, Li Y Drake, Xianwei Ye, Elizabeth R Vogel, Christina M Pabelick, Y S Prakash
Bronchial airways and lung parenchyma undergo both static and dynamic stretch in response to normal breathing as well as in the context of insults such as mechanical ventilation (MV) or in diseases such as asthma and chronic obstructive pulmonary disease (COPD) which lead to airway remodeling involving increased extracellular matrix (ECM) production. Here, the role of fibroblasts is critical, but the relationship between stretch- and fibroblast-induced ECM remodeling under these conditions is not well-explored. Piezo (PZ) channels play a role in mechanotransduction in many cell and organ systems, but their role in mechanical stretch-induced airway remodeling is not known. To explore this, we exposed human lung fibroblasts to 10% static stretch on a background of 5% oscillations for 48 h, with no static stretch considered controls. Collagen I, fibronectin, alpha-smooth muscle actin (α-SMA), and Piezo 1 (PZ1) expression was determined in the presence or absence of Yoda1 (PZ1 agonist) or GsMTx4 (PZ1 inhibitor). Collagen I, fibronectin, and α-SMA expression was increased by stretch and Yoda1, whereas pretreatment with GsMTx4 or knockdown of PZ1 by siRNA blunted this effect. Acute stretch in the presence and absence of Yoda1 demonstrated activation of the ERK pathway but not Smad. Measurement of [Ca2+]i responses to histamine showed significantly greater responses following stretch, effects that were blunted by knockdown of PZ1. Our findings identify an essential role for PZ1 in mechanical stretch-induced production of ECM mediated by ERK phosphorylation and Ca2+ influx in lung fibroblasts. Targeting PZ channels in fibroblasts may constitute a novel approach to ameliorate airway remodeling by decreasing ECM deposition.NEW & NOTEWORTHY The lung is an inherently mechanosensitive organ that can respond to mechanical forces in adaptive or maladaptive ways, including via remodeling resulting in increased fibrosis. We explored the mechanisms that link mechanical forces to remodeling using human lung fibroblasts. We found that mechanosensitive Piezo channels increase with stretch and mediate extracellular matrix formation and the fibroblast-to-myofibroblast transition that occurs with stretch. Our data highlight the importance of Piezo channels in lung mechanotransduction toward remodeling.
{"title":"Piezo channels modulate human lung fibroblast function.","authors":"Mengning Zheng, Yang Yao, Niyati A Borkar, Michael A Thompson, Emily Zhang, Li Y Drake, Xianwei Ye, Elizabeth R Vogel, Christina M Pabelick, Y S Prakash","doi":"10.1152/ajplung.00356.2023","DOIUrl":"10.1152/ajplung.00356.2023","url":null,"abstract":"<p><p>Bronchial airways and lung parenchyma undergo both static and dynamic stretch in response to normal breathing as well as in the context of insults such as mechanical ventilation (MV) or in diseases such as asthma and chronic obstructive pulmonary disease (COPD) which lead to airway remodeling involving increased extracellular matrix (ECM) production. Here, the role of fibroblasts is critical, but the relationship between stretch- and fibroblast-induced ECM remodeling under these conditions is not well-explored. Piezo (PZ) channels play a role in mechanotransduction in many cell and organ systems, but their role in mechanical stretch-induced airway remodeling is not known. To explore this, we exposed human lung fibroblasts to 10% static stretch on a background of 5% oscillations for 48 h, with no static stretch considered controls. Collagen I, fibronectin, alpha-smooth muscle actin (α-SMA), and Piezo 1 (PZ1) expression was determined in the presence or absence of Yoda1 (PZ1 agonist) or GsMTx4 (PZ1 inhibitor). Collagen I, fibronectin, and α-SMA expression was increased by stretch and Yoda1, whereas pretreatment with GsMTx4 or knockdown of PZ1 by siRNA blunted this effect. Acute stretch in the presence and absence of Yoda1 demonstrated activation of the ERK pathway but not Smad. Measurement of [Ca<sup>2+</sup>]<sub>i</sub> responses to histamine showed significantly greater responses following stretch, effects that were blunted by knockdown of PZ1. Our findings identify an essential role for PZ1 in mechanical stretch-induced production of ECM mediated by ERK phosphorylation and Ca<sup>2+</sup> influx in lung fibroblasts. Targeting PZ channels in fibroblasts may constitute a novel approach to ameliorate airway remodeling by decreasing ECM deposition.<b>NEW & NOTEWORTHY</b> The lung is an inherently mechanosensitive organ that can respond to mechanical forces in adaptive or maladaptive ways, including via remodeling resulting in increased fibrosis. We explored the mechanisms that link mechanical forces to remodeling using human lung fibroblasts. We found that mechanosensitive Piezo channels increase with stretch and mediate extracellular matrix formation and the fibroblast-to-myofibroblast transition that occurs with stretch. Our data highlight the importance of Piezo channels in lung mechanotransduction toward remodeling.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142071810","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}
Pub Date : 2024-10-01Epub Date: 2024-07-16DOI: 10.1152/ajplung.00327.2023
Jochen Steppan, Huilei Wang, Kavitha Nandakumar, Mahin Gadkari, Alan Poe, Lydia Pak, Travis Brady, Dan E Berkowitz, Larissa A Shimoda, Lakshmi Santhanam
Conduit pulmonary arterial stiffening and the resultant increase in pulmonary vascular impedance have emerged as an important underlying driver of pulmonary arterial hypertension (PAH). Given that matrix deposition is central to vascular remodeling, we evaluated the role of the collagen cross-linking enzyme lysyl oxidase like 2 (LOXL2) in this study. Human pulmonary artery smooth muscle cells (PASMCs) subjected to hypoxia showed increased LOXL2 secretion. LOXL2 activity and expression were markedly higher in primary PASMCs isolated from the pulmonary arteries of the rat Sugen 5416 + hypoxia (SuHx) model of severe pulmonary hypertension (PH). Similarly, LOXL2 protein and mRNA levels were increased in the pulmonary arteries (PA) and lungs of rats with PH (SuHx and monocrotaline (MCT) models). Pulmonary arteries (PAs) isolated from the rats with PH exhibited hypercontractility to phenylephrine and attenuated vasorelaxation elicited by acetylcholine, indicating severe endothelial dysfunction. Tensile testing revealed a significant increase in PA stiffness in PH. Treatment with PAT-1251, a novel small-molecule LOXL2 inhibitor, improved active and passive properties of the PA ex vivo. There was an improvement in right heart function as measured by right ventricular pressure volume loops in vivo with PAT-1251. Importantly, PAT-1251 treatment ameliorated PH, resulting in improved pulmonary artery pressures, right ventricular remodeling, and survival. Hypoxia-induced LOXL2 activation is a causal mechanism in pulmonary artery stiffening in PH and pulmonary artery mechanical and functional decline. LOXL2 inhibition with PAT-1251 could be a promising approach to improve pulmonary artery pressures, right ventricular elastance, cardiac relaxation, and survival in PAH.NEW & NOTEWORTHY Pulmonary arterial stiffening contributes to the progression of PAH and the deterioration of right heart function. This study shows that LOXL2 is upregulated in rat models of PH. LOXL2 inhibition halts pulmonary vascular remodeling and improves PA contractility, endothelial function, and PA pressure, resulting in prolonged survival. Thus, LOXL2 is an important mediator of PA remodeling and stiffening in PH and a promising target to improve PA pressures and survival in PH.
{"title":"LOXL2 inhibition ameliorates pulmonary artery remodeling in pulmonary hypertension.","authors":"Jochen Steppan, Huilei Wang, Kavitha Nandakumar, Mahin Gadkari, Alan Poe, Lydia Pak, Travis Brady, Dan E Berkowitz, Larissa A Shimoda, Lakshmi Santhanam","doi":"10.1152/ajplung.00327.2023","DOIUrl":"10.1152/ajplung.00327.2023","url":null,"abstract":"<p><p>Conduit pulmonary arterial stiffening and the resultant increase in pulmonary vascular impedance have emerged as an important underlying driver of pulmonary arterial hypertension (PAH). Given that matrix deposition is central to vascular remodeling, we evaluated the role of the collagen cross-linking enzyme lysyl oxidase like 2 (LOXL2) in this study. Human pulmonary artery smooth muscle cells (PASMCs) subjected to hypoxia showed increased LOXL2 secretion. LOXL2 activity and expression were markedly higher in primary PASMCs isolated from the pulmonary arteries of the rat Sugen 5416 + hypoxia (SuHx) model of severe pulmonary hypertension (PH). Similarly, LOXL2 protein and mRNA levels were increased in the pulmonary arteries (PA) and lungs of rats with PH (SuHx and monocrotaline (MCT) models). Pulmonary arteries (PAs) isolated from the rats with PH exhibited hypercontractility to phenylephrine and attenuated vasorelaxation elicited by acetylcholine, indicating severe endothelial dysfunction. Tensile testing revealed a significant increase in PA stiffness in PH. Treatment with PAT-1251, a novel small-molecule LOXL2 inhibitor, improved active and passive properties of the PA ex vivo. There was an improvement in right heart function as measured by right ventricular pressure volume loops in vivo with PAT-1251. Importantly, PAT-1251 treatment ameliorated PH, resulting in improved pulmonary artery pressures, right ventricular remodeling, and survival. Hypoxia-induced LOXL2 activation is a causal mechanism in pulmonary artery stiffening in PH and pulmonary artery mechanical and functional decline. LOXL2 inhibition with PAT-1251 could be a promising approach to improve pulmonary artery pressures, right ventricular elastance, cardiac relaxation, and survival in PAH.<b>NEW & NOTEWORTHY</b> Pulmonary arterial stiffening contributes to the progression of PAH and the deterioration of right heart function. This study shows that LOXL2 is upregulated in rat models of PH. LOXL2 inhibition halts pulmonary vascular remodeling and improves PA contractility, endothelial function, and PA pressure, resulting in prolonged survival. Thus, LOXL2 is an important mediator of PA remodeling and stiffening in PH and a promising target to improve PA pressures and survival in PH.</p>","PeriodicalId":7593,"journal":{"name":"American journal of physiology. Lung cellular and molecular physiology","volume":null,"pages":null},"PeriodicalIF":3.6,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141619057","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}