Pub Date : 2024-08-14DOI: 10.1165/rcmb.2023-0358OC
Elham Javed, Ajay P Nayak, Arun K Jannu, Aaron H Cohen, Isabella Dewes, Ruping Wang, Dale D Tang, Deepak A Deshpande, Raymond B Penn
A-kinase-anchoring proteins (AKAPs) act as scaffold proteins that anchor the regulatory subunits of the cAMP-dependent protein kinase A (PKA) to coordinate and compartmentalize signaling elements and signals downstream of Gs-coupled G protein-coupled receptors (GPCRs). The beta-2-adrenoceptor (β2AR), as well as the Gs-coupled EP2 and EP4 receptor subtypes of the E-prostanoid (EP) receptor subfamily, are effective regulators of multiple airway smooth muscle (ASM) cell functions whose dysregulation contributes of asthma pathobiology. Here, we identify specific roles of the AKAPs Ezrin and Gravin, in differentially regulating PKA substrates downstream of the β2AR, EP2 receptor (EP2R) and EP4 receptor (EP4R). Knockdown of Ezrin, Gravin, or both in primary human ASM cells caused differential phosphorylation of the PKA substrates vasodilator-stimulated phosphoprotein (VASP) and heat shock protein 20 (HSP20). Ezrin knockdown, as well as combined Ezrin + Gravin knockdown significantly reduced the induction of phospho-VASP and phospho-HSP20 by β2AR, EP2R, and EP4R agonists. Gravin knockdown inhibited the induction of phospho-HSP20 by β2AR, EP2R, and EP4R agonists. Knockdown of Ezrin, Gravin, or both also attenuated histamine-induced phosphorylation of MLC20. Moreover, knockdown of Ezrin, Gravin or both suppressed the inhibitory effects of Gs-coupled receptor agonists on cell migration in ASM cells. These findings demonstrate the role of AKAPs in regulating Gs-coupled GPCR signaling and function in ASM, and suggest the therapeutic utility of targeting specific AKAP family members in the management of asthma.
{"title":"A-Kinase-Anchoring-Protein Subtypes Differentially Regulate GPCR Signaling and Function in Human Airway Smooth Muscle.","authors":"Elham Javed, Ajay P Nayak, Arun K Jannu, Aaron H Cohen, Isabella Dewes, Ruping Wang, Dale D Tang, Deepak A Deshpande, Raymond B Penn","doi":"10.1165/rcmb.2023-0358OC","DOIUrl":"10.1165/rcmb.2023-0358OC","url":null,"abstract":"<p><p>A-kinase-anchoring proteins (AKAPs) act as scaffold proteins that anchor the regulatory subunits of the cAMP-dependent protein kinase A (PKA) to coordinate and compartmentalize signaling elements and signals downstream of Gs-coupled G protein-coupled receptors (GPCRs). The beta-2-adrenoceptor (β<sub>2</sub>AR), as well as the Gs-coupled EP2 and EP4 receptor subtypes of the E-prostanoid (EP) receptor subfamily, are effective regulators of multiple airway smooth muscle (ASM) cell functions whose dysregulation contributes of asthma pathobiology. Here, we identify specific roles of the AKAPs Ezrin and Gravin, in differentially regulating PKA substrates downstream of the β<sub>2</sub>AR, EP2 receptor (EP2R) and EP4 receptor (EP4R). Knockdown of Ezrin, Gravin, or both in primary human ASM cells caused differential phosphorylation of the PKA substrates vasodilator-stimulated phosphoprotein (VASP) and heat shock protein 20 (HSP20). Ezrin knockdown, as well as combined Ezrin + Gravin knockdown significantly reduced the induction of phospho-VASP and phospho-HSP20 by β<sub>2</sub>AR, EP2R, and EP4R agonists. Gravin knockdown inhibited the induction of phospho-HSP20 by β<sub>2</sub>AR, EP2R, and EP4R agonists. Knockdown of Ezrin, Gravin, or both also attenuated histamine-induced phosphorylation of MLC20. Moreover, knockdown of Ezrin, Gravin or both suppressed the inhibitory effects of Gs-coupled receptor agonists on cell migration in ASM cells. These findings demonstrate the role of AKAPs in regulating Gs-coupled GPCR signaling and function in ASM, and suggest the therapeutic utility of targeting specific AKAP family members in the management of asthma.</p>","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141981495","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 : 2024-08-14DOI: 10.1165/rcmb.2024-0145PS
Ruslan Rafikov, Vinicio de Jesus Perez, Aleksandr Dekan, Tatiana V Kudryashova, Olga Rafikova
Expanding upon the critical advancements brought forth by single-cell omics in pulmonary hypertension (PH) research, this review delves deep into how these technologies have been piloted in a new era of understanding this complex disease. By leveraging the power of single cell transcriptomics (scRNA-seq), researchers can now dissect the complicated cellular ecosystem of the lungs, examining the key players such as endothelial cells, smooth muscle cells, pericytes, and immune cells, and their unique roles in the pathogenesis of PH. This more granular view is beyond the limitations of traditional bulk analysis, allowing for the identification of novel therapeutic targets previously obscured in the aggregated data. Connectome analysis based on single-cell omics of the cells involved in pathological changes can reveal a clearer picture of the cellular interactions and transitions in the cellular subtypes. Furthermore, the review acknowledges the challenges that lie ahead, including the need for enhancing the resolution of scRNA-seq to capture even finer details of cellular changes, overcoming logistical barriers in processing human tissue samples, and the necessity of integrating diverse omics approaches to fully comprehend the molecular underpinnings of PH. The promise of these single-cell technologies is immense, offering the potential for targeted drug development and the discovery of biomarkers for early diagnosis and disease monitoring. Through these advancements, the field moves closer to realizing the goal of precision medicine for patients with PH.
{"title":"Deciphering the Complexities of Pulmonary Hypertension: The Emergent Role of Single-Cell Omics.","authors":"Ruslan Rafikov, Vinicio de Jesus Perez, Aleksandr Dekan, Tatiana V Kudryashova, Olga Rafikova","doi":"10.1165/rcmb.2024-0145PS","DOIUrl":"10.1165/rcmb.2024-0145PS","url":null,"abstract":"<p><p>Expanding upon the critical advancements brought forth by single-cell omics in pulmonary hypertension (PH) research, this review delves deep into how these technologies have been piloted in a new era of understanding this complex disease. By leveraging the power of single cell transcriptomics (scRNA-seq), researchers can now dissect the complicated cellular ecosystem of the lungs, examining the key players such as endothelial cells, smooth muscle cells, pericytes, and immune cells, and their unique roles in the pathogenesis of PH. This more granular view is beyond the limitations of traditional bulk analysis, allowing for the identification of novel therapeutic targets previously obscured in the aggregated data. Connectome analysis based on single-cell omics of the cells involved in pathological changes can reveal a clearer picture of the cellular interactions and transitions in the cellular subtypes. Furthermore, the review acknowledges the challenges that lie ahead, including the need for enhancing the resolution of scRNA-seq to capture even finer details of cellular changes, overcoming logistical barriers in processing human tissue samples, and the necessity of integrating diverse omics approaches to fully comprehend the molecular underpinnings of PH. The promise of these single-cell technologies is immense, offering the potential for targeted drug development and the discovery of biomarkers for early diagnosis and disease monitoring. Through these advancements, the field moves closer to realizing the goal of precision medicine for patients with PH.</p>","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141981496","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 : 2024-08-13DOI: 10.1165/rcmb.2024-0326ED
Elizabeth F Redente
{"title":"The Hidden Link Between Chronic Kidney Disease and Lung Injury.","authors":"Elizabeth F Redente","doi":"10.1165/rcmb.2024-0326ED","DOIUrl":"https://doi.org/10.1165/rcmb.2024-0326ED","url":null,"abstract":"","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974863","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 : 2024-08-13DOI: 10.1165/rcmb.2024-0325ED
Akshat Sharma, Amali E Samarasinghe
{"title":"\"It's A Trap!\": Eosinophils Caught Between Pro- and Anti-inflammatory Responses.","authors":"Akshat Sharma, Amali E Samarasinghe","doi":"10.1165/rcmb.2024-0325ED","DOIUrl":"https://doi.org/10.1165/rcmb.2024-0325ED","url":null,"abstract":"","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974859","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 : 2024-08-13DOI: 10.1165/rcmb.2024-0346ED
Hong-Long James Ji, Gang Liu
{"title":"Mapping Host-Microbe Omics Interactions in Severe Community-acquired Pneumonia.","authors":"Hong-Long James Ji, Gang Liu","doi":"10.1165/rcmb.2024-0346ED","DOIUrl":"10.1165/rcmb.2024-0346ED","url":null,"abstract":"","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974860","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 : 2024-08-13DOI: 10.1165/rcmb.2024-0350ED
Isabella Cattani-Cavalieri, Rennolds S Ostrom
{"title":"One More Negative Regulator of AC6: S-Nitrosylation.","authors":"Isabella Cattani-Cavalieri, Rennolds S Ostrom","doi":"10.1165/rcmb.2024-0350ED","DOIUrl":"https://doi.org/10.1165/rcmb.2024-0350ED","url":null,"abstract":"","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974861","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 : 2024-08-13DOI: 10.1165/rcmb.2024-0344ED
Yun Michael Shim, Jamie L MacLeod
{"title":"Sex Matters: A Deep Dive into Sex Differences in COPD.","authors":"Yun Michael Shim, Jamie L MacLeod","doi":"10.1165/rcmb.2024-0344ED","DOIUrl":"https://doi.org/10.1165/rcmb.2024-0344ED","url":null,"abstract":"","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141974862","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 : 2024-08-12DOI: 10.1165/rcmb.2024-0207OC
Stella Tommasi, Luciano Brocchieri, Silvia Tornaletti, Ahmad Besaratinia
Despite the ongoing epidemic of youth vaping, the long-term health consequences of electronic cigarette use are largely unknown. We report the effects of vaping versus smoking on the oral cell methylome of healthy young vapers and smokers relative to non-users. Whereas vapers and smokers differ in number of differentially methylated regions (DMRs) (831 vs 2,863), they share striking similarities in the distribution and patterns of DNA methylation, chromatin states, transcription factor binding motifs, and pathways. There is substantial overlap in DMR-associated genes between vapers and smokers, with the shared subset of genes enriched for transcriptional regulation, signaling, tobacco use disorders, and cancer-related pathways. Of significance is the identification of a common hypermethylated DMR at the promoter of "Hypermethylated In Cancer 1" (HIC1), a tumor suppressor gene frequently silenced in smoking-related cancers. Our data support a potential link between epigenomic dysregulation in youth vapers and disease risk. These novel findings have significant implications for public health and tobacco product regulation.
尽管青少年吸食电子烟正在流行,但使用电子烟的长期健康后果在很大程度上还不为人所知。我们报告了吸烟与吸电子烟对健康年轻吸电子烟者和吸烟者口腔细胞甲基组的影响。虽然吸食者和吸烟者在差异甲基化区域(DMRs)的数量(831 对 2863)上存在差异,但他们在 DNA 甲基化的分布和模式、染色质状态、转录因子结合基序和途径方面却有着惊人的相似之处。吸食者和吸烟者的 DMR 相关基因有大量重叠,共同的基因子集富含转录调控、信号转导、烟草使用障碍和癌症相关途径。值得注意的是,在 "HIC1"(Hypermethylated In Cancer 1)的启动子上发现了一个共同的高甲基化 DMR,HIC1 是一种肿瘤抑制基因,在与吸烟有关的癌症中经常被沉默。我们的数据支持青少年吸食者表观基因组失调与疾病风险之间的潜在联系。这些新发现对公共卫生和烟草产品监管具有重要意义。
{"title":"Epigenomic Dysregulation in Youth Vapers: Implications for Disease Risk Assessment.","authors":"Stella Tommasi, Luciano Brocchieri, Silvia Tornaletti, Ahmad Besaratinia","doi":"10.1165/rcmb.2024-0207OC","DOIUrl":"https://doi.org/10.1165/rcmb.2024-0207OC","url":null,"abstract":"<p><p>Despite the ongoing epidemic of youth vaping, the long-term health consequences of electronic cigarette use are largely unknown. We report the effects of vaping <i>versus</i> smoking on the oral cell methylome of healthy young vapers and smokers relative to non-users. Whereas vapers and smokers differ in number of differentially methylated regions (DMRs) (831 <i>vs</i> 2,863), they share striking similarities in the distribution and patterns of DNA methylation, chromatin states, transcription factor binding motifs, and pathways. There is substantial overlap in DMR-associated genes between vapers and smokers, with the shared subset of genes enriched for transcriptional regulation, signaling, tobacco use disorders, and cancer-related pathways. Of significance is the identification of a common hypermethylated DMR at the promoter of \"Hypermethylated In Cancer 1\" (<i>HIC1</i>), a tumor suppressor gene frequently silenced in smoking-related cancers. Our data support a potential link between epigenomic dysregulation in youth vapers and disease risk. These novel findings have significant implications for public health and tobacco product regulation.</p>","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141915853","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 : 2024-08-12DOI: 10.1165/rcmb.2023-0449OC
Paula Martín-Vicente, Cecilia López-Martínez, Inés López-Alonso, Sara M Exojo-Ramírez, Israel David Duarte-Herrera, Laura Amado-Rodríguez, Irene Ordoñez, Elias Cuesta-Llavona, Juan Gómez, Natalia Campo, Cecilia M O'Kane, Daniel F McAuley, Covadonga Huidobro, Guillermo M Albaiceta
Severe lung injury requiring mechanical ventilation may lead to secondary fibrosis. Senescence, a cell response characterized by cell cycle arrest and a shift towards a proinflammatory/profibrotic phenotype, is one of the involved mechanisms. Here, we explore the contribution of mechanical stretch as trigger of senescence of the respiratory epithelium and its link with fibrosis. Human lung epithelial cells and fibroblasts were exposed in vitro to mechanical stretch, and senescence assessed. In addition, fibroblasts were exposed to culture media preconditioned by senescent epithelial cells and their activation was studied. Transcriptomic profiles from stretched, senescent epithelial cells and activated fibroblasts were combined to identify potential activated pathways. Finally, the senolytic effects of digoxin were tested in these models. Mechanical stretch induced senescence in lung epithelial cells, but not in fibroblasts. This stretch-induced senescence has specific features compared to senescence induced by doxorubicin. Fibroblasts were activated after exposure to supernatants conditioned by epithelial senescent cells. Transcriptomic analyses revealed notch signaling as a potential responsible for the epithelial-mesenchymal crosstalk, as blockade of this pathway inhibits fibroblast activation. Treatment with digoxin reduced the percentage of senescent cells after stretch and ameliorated the fibroblast response to preconditioned media. These results suggest that lung fibrosis in response to mechanical stretch may be caused by the paracrine effects of senescent cells. This pathogenetic mechanism can be pharmacologically manipulated to improve lung repair.
{"title":"Mechanical Stretch Induces Senescence of Lung Epithelial Cells and Drives Fibroblast Activation by Paracrine Mechanisms.","authors":"Paula Martín-Vicente, Cecilia López-Martínez, Inés López-Alonso, Sara M Exojo-Ramírez, Israel David Duarte-Herrera, Laura Amado-Rodríguez, Irene Ordoñez, Elias Cuesta-Llavona, Juan Gómez, Natalia Campo, Cecilia M O'Kane, Daniel F McAuley, Covadonga Huidobro, Guillermo M Albaiceta","doi":"10.1165/rcmb.2023-0449OC","DOIUrl":"https://doi.org/10.1165/rcmb.2023-0449OC","url":null,"abstract":"<p><p>Severe lung injury requiring mechanical ventilation may lead to secondary fibrosis. Senescence, a cell response characterized by cell cycle arrest and a shift towards a proinflammatory/profibrotic phenotype, is one of the involved mechanisms. Here, we explore the contribution of mechanical stretch as trigger of senescence of the respiratory epithelium and its link with fibrosis. Human lung epithelial cells and fibroblasts were exposed <i>in vitro</i> to mechanical stretch, and senescence assessed. In addition, fibroblasts were exposed to culture media preconditioned by senescent epithelial cells and their activation was studied. Transcriptomic profiles from stretched, senescent epithelial cells and activated fibroblasts were combined to identify potential activated pathways. Finally, the senolytic effects of digoxin were tested in these models. Mechanical stretch induced senescence in lung epithelial cells, but not in fibroblasts. This stretch-induced senescence has specific features compared to senescence induced by doxorubicin. Fibroblasts were activated after exposure to supernatants conditioned by epithelial senescent cells. Transcriptomic analyses revealed notch signaling as a potential responsible for the epithelial-mesenchymal crosstalk, as blockade of this pathway inhibits fibroblast activation. Treatment with digoxin reduced the percentage of senescent cells after stretch and ameliorated the fibroblast response to preconditioned media. These results suggest that lung fibrosis in response to mechanical stretch may be caused by the paracrine effects of senescent cells. This pathogenetic mechanism can be pharmacologically manipulated to improve lung repair.</p>","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141970431","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 : 2024-08-07DOI: 10.1165/rcmb.2023-0447OC
Saeid Maghsoudi, Vikram Bhatia, Martha Hinton, Nisha Singh, Mohd Wasif Khan, Prashen Chelikani, Shyamala Dakshinamurti
Persistent pulmonary hypertension of the newborn (PPHN) is a hypoxic disorder of pulmonary vascular relaxation, mediated in part by adenylyl cyclase (AC). Neonatal pulmonary arteries (PA) express mainly AC6 isoform, followed by AC3, 7 and 9. AC6 expression is upregulated in hypoxia. We reported AC enzyme inhibition due to S-nitrosylation in PPHN PA, and in PA myocytes exposed to hypoxia. We hypothesize that hypoxia promotes cysteine thiol nitrosylation of AC6, impairing cAMP production. HEK293T cells stably expressing AC isoforms (AC3, 5, 6, 7, 9), or cysteine-to-alanine mutants AC6_C1004A, AC6_C1145A or AC6_C447A were cultured in normoxia (21% O2) or hypoxia (10% O2) for 72 hours, or challenged with nitroso donor S-nitrosocysteine (CysNO). AC activity was determined by real-time live-cell cAMP measurement (cADDis assay) or terbium-norfloxacin AC catalytic assay, with or without challenge by allosteric agonist forskolin; protein S-nitrosylation detected by biotin switch method and quantified by affinity precipitation. Only AC6 catalytic activity is inhibited in hypoxia or by S-nitrosylating agent, in presence or absence of forskolin; impaired cAMP production in hypoxia correlates with increased cysteine nitrosylation of AC6. Selective AC6 inhibition in pulmonary artery myocytes extinguishes AC sensitivity to inhibition by hypoxia. Alanine substitution of C1004, but not of other cysteines, decreases S-nitrosylation of AC6. AC activity is diminished in AC6_C1004A compared to AC6 wild type. Substitution of C1004 also extinguishes the inhibition of AC6 by hypoxia. We conclude AC6 is uniquely S-nitrosylated in hypoxia, inhibiting its activity and cAMP generation. We speculate that S-nitrosylation at C1004 may inhibit AC6 interaction with Gαs, playing a role in PPHN pathophysiology.
{"title":"Adenylyl Cyclase Isoform 6 in the Pulmonary Artery Is Inhibited by Hypoxia via Cysteine Nitrosylation.","authors":"Saeid Maghsoudi, Vikram Bhatia, Martha Hinton, Nisha Singh, Mohd Wasif Khan, Prashen Chelikani, Shyamala Dakshinamurti","doi":"10.1165/rcmb.2023-0447OC","DOIUrl":"https://doi.org/10.1165/rcmb.2023-0447OC","url":null,"abstract":"<p><p>Persistent pulmonary hypertension of the newborn (PPHN) is a hypoxic disorder of pulmonary vascular relaxation, mediated in part by adenylyl cyclase (AC). Neonatal pulmonary arteries (PA) express mainly AC6 isoform, followed by AC3, 7 and 9. AC6 expression is upregulated in hypoxia. We reported AC enzyme inhibition due to S-nitrosylation in PPHN PA, and in PA myocytes exposed to hypoxia. We hypothesize that hypoxia promotes cysteine thiol nitrosylation of AC6, impairing cAMP production. HEK293T cells stably expressing AC isoforms (AC3, 5, 6, 7, 9), or cysteine-to-alanine mutants AC6_C1004A, AC6_C1145A or AC6_C447A were cultured in normoxia (21% O2) or hypoxia (10% O2) for 72 hours, or challenged with nitroso donor S-nitrosocysteine (CysNO). AC activity was determined by real-time live-cell cAMP measurement (cADDis assay) or terbium-norfloxacin AC catalytic assay, with or without challenge by allosteric agonist forskolin; protein S-nitrosylation detected by biotin switch method and quantified by affinity precipitation. Only AC6 catalytic activity is inhibited in hypoxia or by S-nitrosylating agent, in presence or absence of forskolin; impaired cAMP production in hypoxia correlates with increased cysteine nitrosylation of AC6. Selective AC6 inhibition in pulmonary artery myocytes extinguishes AC sensitivity to inhibition by hypoxia. Alanine substitution of C1004, but not of other cysteines, decreases S-nitrosylation of AC6. AC activity is diminished in AC6_C1004A compared to AC6 wild type. Substitution of C1004 also extinguishes the inhibition of AC6 by hypoxia. We conclude AC6 is uniquely S-nitrosylated in hypoxia, inhibiting its activity and cAMP generation. We speculate that S-nitrosylation at C1004 may inhibit AC6 interaction with Gαs, playing a role in PPHN pathophysiology.</p>","PeriodicalId":7655,"journal":{"name":"American Journal of Respiratory Cell and Molecular Biology","volume":null,"pages":null},"PeriodicalIF":5.9,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141896540","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}