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Sun MR, Gonzalez S, Huang JB, Zhou Q, Cherukuri A, Adavadkar R, Yan HL, Sun SH, Zhou G, Raj JU, Chen T. Biphasic regulation of miR-17∼92 transcription during hypoxia: roles of HIF1 and p53 hyperphosphorylation at ser15. Am J Physiol Lung Cell Mol Physiol 2024; 327:L102-L113. [PMID: 38501173 DOI: 10.1152/ajplung.00127.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 03/07/2024] [Accepted: 03/07/2024] [Indexed: 03/20/2024] Open
Abstract
We have reported previously that during hypoxia exposure, the expression of mature miR-17∼92 was first upregulated and then downregulated in pulmonary artery smooth muscle cells (PASMC) and in mouse lungs in vitro and in vivo. Here, we investigated the mechanisms regulating this biphasic expression of miR-17∼92 in PASMC in hypoxia. We measured the level of primary miR-17∼92 in PASMC during hypoxia exposure and found that short-term hypoxia exposure (3% O2, 6 h) induced the level of primary miR-17∼92, whereas long-term hypoxia exposure (3% O2, 24 h) decreased its level, suggesting a biphasic regulation of miR-17∼92 expression at the transcriptional level. We found that short-term hypoxia-induced upregulation of miR-17∼92 was hypoxia-inducible factor 1α (HIF1α) and E2F1 dependent. Two HIF1α binding sites on miR-17∼92 promoter were identified. We also found that long-term hypoxia-induced suppression of miR-17∼92 expression could be restored by silencing of p53. Mutation of the p53-binding sites in the miR-17∼92 promoter increased miR-17∼92 promoter activity in both normoxia and hypoxia. Our findings suggest that the biphasic transcriptional regulation of miR-17∼92 during hypoxia is controlled by HIF1/E2F1 and p53 in PASMC: during short-term hypoxia exposure, stabilization of HIF1 and induction of E2F1 induce the transcription of miR-17∼92, whereas during long-term hypoxia exposure, hyperphosphorylation of p53 suppresses the expression of miR-17∼92.NEW & NOTEWORTHY We showed that the biphasic transcriptional regulation of miR-17∼92 during hypoxia is controlled by two distinct mechanisms: during short-term hypoxia exposure, induction of HIF1 and E2F1 upregulates miR-17∼92. Longer hypoxia exposure induces hyperphosphorylation of p53 at ser15, which leads to its binding to miR-17∼92 promoter and inhibition of its expression. Our findings provide novel insights into the spatiotemporal regulation of miR-17∼92 that may play a role in the development of human lung diseases including pulmonary hypertension (PH).
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Affiliation(s)
- Miranda R Sun
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Susana Gonzalez
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Jason B Huang
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Qiyuan Zhou
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Arjun Cherukuri
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Rohan Adavadkar
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States
| | - Hong-Li Yan
- Department of Medical Genetics, Second Military Medical University, Shanghai, People's Republic of China
| | - Shu-Han Sun
- Department of Medical Genetics, Second Military Medical University, Shanghai, People's Republic of China
| | - Guofei Zhou
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States
- University of Illinois Cancer Center, Chicago, Illinois, United States
| | - J Usha Raj
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States
- Children's Hospital University of Illinois, University of Illinois Hospital and Health Sciences System, Chicago, Illinois, United States
| | - Tianji Chen
- Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States
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2
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Boedtkjer E, Ara T. Strengthening the basics: acids and bases influence vascular structure and function, tissue perfusion, blood pressure, and human cardiovascular disease. Pflugers Arch 2024; 476:623-637. [PMID: 38383822 DOI: 10.1007/s00424-024-02926-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/08/2024] [Accepted: 02/09/2024] [Indexed: 02/23/2024]
Abstract
Acids and their conjugate bases accumulate in or dissipate from the interstitial space when tissue perfusion does not match the metabolic demand. Extracellular acidosis dilates most arterial beds, but associated acid-base disturbances-e.g., intracellular acidification and decreases in HCO3- concentration-can also elicit pro-contractile influences that diminish vasodilation and even dominate in some vascular beds to cause vasoconstriction. The ensemble activities of the acid-base-sensitive reactions in vascular smooth muscle and endothelial cells optimize vascular resistance for blood pressure control and direct the perfusion towards active tissue. In this review, we describe the mechanisms of intracellular pH regulation in the vascular wall and discuss how vascular smooth muscle and endothelial cells sense acid-base disturbances. We further deliberate on the functional effects of local acid-base disturbances and their integrated cardiovascular consequences under physiological and pathophysiological conditions. Finally, we address how mutations and polymorphisms in the molecular machinery that regulates pH locally and senses acid-base disturbances in the vascular wall can result in cardiovascular disease. Based on the emerging molecular insight, we propose that targeting local pH-dependent effectors-rather than systemic acid-base disturbances-has therapeutic potential to interfere with the progression and reduce the severity of cardiovascular disease.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Hoegh-Guldbergs Gade 10, DK-8000, Aarhus, Denmark.
| | - Tarannum Ara
- Department of Biomedicine, Aarhus University, Hoegh-Guldbergs Gade 10, DK-8000, Aarhus, Denmark
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Yu H, Wang X, Tian R, Li X, Xu C, Fei J, Li T, Yin Z. Myometrium infection decreases TREK1 through NHE1 and increases contraction in pregnant mice. Am J Physiol Cell Physiol 2024; 326:C1106-C1119. [PMID: 38344766 DOI: 10.1152/ajpcell.00598.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 03/23/2024]
Abstract
Intrauterine infection during pregnancy can enhance uterine contractions. A two-pore K+ channel TREK1 is crucial for maintaining uterine quiescence and reducing contractility, with its properties regulated by pH changes in cell microenvironment. Meanwhile, the sodium hydrogen exchanger 1 (NHE1) plays a pivotal role in modulating cellular pH homeostasis, and its activation increases smooth muscle tension. By establishing an infected mouse model of Escherichia coli (E. coli) and lipopolysaccharide (LPS), we used Western blotting, real-time quantitative polymerase chain reaction, and immunofluorescence to detect changes of TREK1 and NHE1 expression in the myometrium, and isometric recording measured the uterus contraction. The NHE1 inhibitor cariporide was used to explore the effect of NHE1 on TREK1. Finally, cell contraction assay and siRNA transfection were performed to clarify the relationship between NHE1 and TREK1 in vitro. We found that the uterine contraction was notably enhanced in infected mice with E. coli and LPS administration. Meanwhile, TREK1 expression was reduced, whereas NHE1 expression was upregulated in infected mice. Cariporide alleviated the increased uterine contraction and promoted myometrium TREK1 expression in LPS-injected mice. Furthermore, suppression of NHE1 with siRNA transfection inhibited the contractility of uterine smooth muscle cells and activated the TREK1. Altogether, our findings indicate that infection increases the uterine contraction by downregulating myometrium TREK1 in mice, and the inhibition of TREK1 is attributed to the activation of NHE1.NEW & NOTEWORTHY Present work found that infection during pregnancy will increase myometrium contraction. Infection downregulated NHE1 and followed TREK1 expression and activation decrease in myometrium, resulting in increased myometrium contraction.
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Affiliation(s)
- Huihui Yu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xingxing Wang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Ruixian Tian
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xuan Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Chenyi Xu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jiajia Fei
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
| | - Tengteng Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zongzhi Yin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
- NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, China
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Fang Q, Bai Y, Hu S, Ding J, Liu L, Dai M, Qiu J, Wu L, Rao X, Wang Y. Unleashing the Potential of Nrf2: A Novel Therapeutic Target for Pulmonary Vascular Remodeling. Antioxidants (Basel) 2023; 12:1978. [PMID: 38001831 PMCID: PMC10669195 DOI: 10.3390/antiox12111978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/22/2023] [Accepted: 11/05/2023] [Indexed: 11/26/2023] Open
Abstract
Pulmonary vascular remodeling, characterized by the thickening of all three layers of the blood vessel wall, plays a central role in the pathogenesis of pulmonary hypertension (PH). Despite the approval of several drugs for PH treatment, their long-term therapeutic effect remains unsatisfactory, as they mainly focus on vasodilation rather than addressing vascular remodeling. Therefore, there is an urgent need for novel therapeutic targets in the treatment of PH. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a vital transcription factor that regulates endogenous antioxidant defense and emerges as a novel regulator of pulmonary vascular remodeling. Growing evidence has suggested an involvement of Nrf2 and its downstream transcriptional target in the process of pulmonary vascular remodeling. Pharmacologically targeting Nrf2 has demonstrated beneficial effects in various diseases, and several Nrf2 inducers are currently undergoing clinical trials. However, the exact potential and mechanism of Nrf2 as a therapeutic target in PH remain unknown. Thus, this review article aims to comprehensively explore the role and mechanism of Nrf2 in pulmonary vascular remodeling associated with PH. Additionally, we provide a summary of Nrf2 inducers that have shown therapeutic potential in addressing the underlying vascular remodeling processes in PH. Although Nrf2-related therapies hold great promise, further research is necessary before their clinical implementation can be fully realized.
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Affiliation(s)
- Qin Fang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yang Bai
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Shuiqing Hu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jie Ding
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lei Liu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Meiyan Dai
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Jie Qiu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Lujin Wu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xiaoquan Rao
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yan Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China; (Q.F.); (Y.B.); (S.H.); (J.D.); (L.L.); (M.D.); (J.Q.); (L.W.)
- Hubei Key Laboratory of Genetics and Molecular Mechanisms of Cardiological Disorders, Huazhong University of Science and Technology, Wuhan 430030, China
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Yi D, Liu B, Ding H, Li S, Li R, Pan J, Ramirez K, Xia X, Kala M, Ye Q, Lee WH, Frye RE, Wang T, Zhao Y, Knox KS, Glembotski CC, Fallon MB, Dai Z. E2F1 Mediates SOX17 Deficiency-Induced Pulmonary Hypertension. Hypertension 2023; 80:2357-2371. [PMID: 37737027 PMCID: PMC10591929 DOI: 10.1161/hypertensionaha.123.21241] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 08/17/2023] [Indexed: 09/23/2023]
Abstract
BACKGROUND Rare genetic variants and genetic variation at loci in an enhancer in SOX17 (SRY-box transcription factor 17) are identified in patients with idiopathic pulmonary arterial hypertension (PAH) and PAH with congenital heart disease. However, the exact role of genetic variants or mutations in SOX17 in PAH pathogenesis has not been reported. METHODS SOX17 expression was evaluated in the lungs and pulmonary endothelial cells (ECs) of patients with idiopathic PAH. Mice with Tie2Cre-mediated Sox17 knockdown and EC-specific Sox17 deletion were generated to determine the role of SOX17 deficiency in the pathogenesis of PAH. Human pulmonary ECs were cultured to understand the role of SOX17 deficiency. Single-cell RNA sequencing, RNA-sequencing analysis, and luciferase assay were performed to understand the underlying molecular mechanisms of SOX17 deficiency-induced PAH. E2F1 (E2F transcription factor 1) inhibitor HLM006474 was used in EC-specific Sox17 mice. RESULTS SOX17 expression was downregulated in the lung and pulmonary ECs from patients with idiopathic PAH. Mice with Tie2Cre-mediated Sox17 knockdown and EC-specific Sox17 deletion induced spontaneously mild pulmonary hypertension. Loss of endothelial Sox17 in EC exacerbated hypoxia-induced pulmonary hypertension in mice. Loss of SOX17 in lung ECs induced endothelial dysfunctions including upregulation of cell cycle programming, proliferative and antiapoptotic phenotypes, augmentation of paracrine effect on pulmonary arterial smooth muscle cells, impaired cellular junction, and BMP (bone morphogenetic protein) signaling. E2F1 signaling was shown to mediate the SOX17 deficiency-induced EC dysfunction. Pharmacological inhibition of E2F1 in Sox17 EC-deficient mice attenuated pulmonary hypertension development. CONCLUSIONS Our study demonstrated that endothelial SOX17 deficiency induces pulmonary hypertension through E2F1. Thus, targeting E2F1 signaling represents a promising approach in patients with PAH.
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Affiliation(s)
- Dan Yi
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Bin Liu
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Hongxu Ding
- Department of Pharmacy Practice & Science, College of Pharmacy, University of Arizona, Tucson, Arizona, USA
| | - Shuai Li
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Rebecca Li
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Jiakai Pan
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Karina Ramirez
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Xiaomei Xia
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Mrinalini Kala
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Qinmao Ye
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Won Hee Lee
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Basic Medical Sciences, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | | | - Ting Wang
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Environmental Health Science and Center of Translational Science, Florida International University, Port Saint Lucie, Florida, USA
| | - Yutong Zhao
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Kenneth S. Knox
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Christopher C. Glembotski
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Michael B. Fallon
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Zhiyu Dai
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
- Sarver Heart Center, University of Arizona, Tucson, Arizona, USA
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6
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Yi D, Liu B, Ding H, Li S, Li R, Pan J, Ramirez K, Xia X, Kala M, Singh I, Ye Q, Lee WH, Frye RE, Wang T, Zhao Y, Knox KS, Glembotski CC, Fallon MB, Dai Z. E2F1 Mediates SOX17 Deficiency-Induced Pulmonary Hypertension. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.15.528740. [PMID: 36824855 PMCID: PMC9949178 DOI: 10.1101/2023.02.15.528740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Rationale Rare genetic variants and genetic variation at loci in an enhancer in SRY-Box Transcription Factor 17 (SOX17) are identified in patients with idiopathic pulmonary arterial hypertension (PAH) and PAH with congenital heart disease. However, the exact role of genetic variants or mutation in SOX17 in PAH pathogenesis has not been reported. Objectives To investigate the role of SOX17 deficiency in pulmonary hypertension (PH) development. Methods Human lung tissue and endothelial cells (ECs) from IPAH patients were used to determine the expression of SOX17. Tie2Cre-mediated and EC-specific deletion of Sox17 mice were assessed for PH development. Single-cell RNA sequencing analysis, human lung ECs, and smooth muscle cell culture were performed to determine the role and mechanisms of SOX17 deficiency. A pharmacological approach was used in Sox17 deficiency mice for therapeutic implication. Measurement and Main Results SOX17 expression was downregulated in the lungs and pulmonary ECs of IPAH patients. Mice with Tie2Cre mediated Sox17 knockdown and EC-specific Sox17 deletion developed spontaneously mild PH. Loss of endothelial Sox17 in EC exacerbated hypoxia-induced PH in mice. Loss of SOX17 in lung ECs induced endothelial dysfunctions including upregulation of cell cycle programming, proliferative and anti-apoptotic phenotypes, augmentation of paracrine effect on pulmonary arterial smooth muscle cells, impaired cellular junction, and BMP signaling. E2F Transcription Factor 1 (E2F1) signaling was shown to mediate the SOX17 deficiency-induced EC dysfunction and PH development. Conclusions Our study demonstrated that endothelial SOX17 deficiency induces PH through E2F1 and targeting E2F1 signaling represents a promising approach in PAH patients.
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Affiliation(s)
- Dan Yi
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Bin Liu
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Hongxu Ding
- Department of Pharmacy Practice & Science, College of Pharmacy, University of Arizona, Tucson, Arizona, USA
| | - Shuai Li
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Rebecca Li
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Jiakai Pan
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Karina Ramirez
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Xiaomei Xia
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Mrinalini Kala
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Indrapal Singh
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Qinmao Ye
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Won Hee Lee
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Basic Medical Sciences, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | | | - Ting Wang
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Environmental Health Science and Center of Translational Science, Florida International University, Port Saint Lucie, Florida, USA
| | - Yutong Zhao
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Kenneth S. Knox
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Christopher C. Glembotski
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Michael B. Fallon
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
| | - Zhiyu Dai
- Division of Pulmonary, Critical Care and Sleep, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Department of Internal Medicine, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- Translational Cardiovascular Research Center, College of Medicine-Phoenix, University of Arizona, Phoenix, Arizona, USA
- BIO5 Institute, University of Arizona, Tucson, Arizona, USA
- Sarver Heart Center, University of Arizona, Tucson, Arizona, USA
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7
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Lade JM, Andrade MR, Undem C, Walker J, Jiang H, Yun X, Shimoda LA. Hypoxia enhances interactions between Na +/H + exchanger isoform 1 and actin filaments via ezrin in pulmonary vascular smooth muscle. Front Physiol 2023; 14:1108304. [PMID: 36926194 PMCID: PMC10011449 DOI: 10.3389/fphys.2023.1108304] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 01/24/2023] [Indexed: 03/08/2023] Open
Abstract
Exposure to hypoxia, due to high altitude or chronic lung disease, leads to structural changes in the pulmonary vascular wall, including hyperplasia and migration of pulmonary arterial smooth muscle cells (PASMCs). Previous studies showed that hypoxia upregulates the expression of Na+/H+ exchanger isoform 1 (NHE1) and that inhibition or loss of NHE1 prevents hypoxia-induced PASMC migration and proliferation. The exact mechanism by which NHE1 controls PASMC function has not been fully delineated. In fibroblasts, NHE1 has been shown to act as a membrane anchor for actin filaments, via binding of the adaptor protein, ezrin. Thus, in this study, we tested the role of ezrin and NHE1/actin interactions in controlling PASMC function. Using rat PASMCs exposed to in vitro hypoxia (4% O2, 24 h) we found that hypoxic exposure increased phosphorylation (activation) of ezrin, and promoted interactions between NHE1, phosphorylated ezrin and smooth muscle specific α-actin (SMA) as measured via immunoprecipitation and co-localization. Overexpression of wild-type human NHE1 in the absence of hypoxia was sufficient to induce PASMC migration and proliferation, whereas inhibiting ezrin phosphorylation with NSC668394 suppressed NHE1/SMA co-localization and migration in hypoxic PASMCs. Finally, overexpressing a version of human NHE1 in which amino acids were mutated to prevent NHE1/ezrin/SMA interactions was unable to increase PASMC migration and proliferation despite exhibiting normal Na+/H+ exchange activity. From these results, we conclude that hypoxic exposure increases ezrin phosphorylation in PASMCs, leading to enhanced ezrin/NHE1/SMA interaction. We further speculate that these interactions promote anchoring of the actin cytoskeleton to the membrane to facilitate the changes in cell movement and shape required for migration and proliferation.
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Affiliation(s)
- Julie M Lade
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Baltimore, MD, United States
| | - Manuella R Andrade
- Department of Physiology, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Clark Undem
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Baltimore, MD, United States
| | - Jasmine Walker
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Baltimore, MD, United States
| | - Haiyang Jiang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Baltimore, MD, United States
| | - Xin Yun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Baltimore, MD, United States
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Baltimore, MD, United States
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8
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Liu R, Xu C, Zhang W, Cao Y, Ye J, Li B, Jia S, Weng L, Liu Y, Liu L, Zheng M. FUNDC1-mediated mitophagy and HIF1α activation drives pulmonary hypertension during hypoxia. Cell Death Dis 2022; 13:634. [PMID: 35864106 PMCID: PMC9304375 DOI: 10.1038/s41419-022-05091-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 07/06/2022] [Accepted: 07/11/2022] [Indexed: 01/21/2023]
Abstract
Hypoxic pulmonary hypertension (PH) is a progressive disease characterized by hyper-proliferation of pulmonary vascular cells including pulmonary artery smooth muscle cells (PASMCs) and can lead to right heart failure and early death. Selective degradation of mitochondria by mitophagy during hypoxia regulates mitochondrial functions in many cells, however, it is not clear if mitophagy is involved in the pathogenesis of hypoxic PH. By employing the hypoxic mitophagy receptor Fundc1 knockout (KO) and transgenic (TG) mouse models, combined hypoxic PH models, the current study found that mitophagy is actively involved in hypoxic PH through regulating PASMC proliferation. In the pulmonary artery medium from hypoxic PH mice, mitophagy was upregulated, accompanied with the increased active form of FUNDC1 protein and the enhanced binding affinity of FUNDC1 with LC3B. In PASMCs, overexpression of FUNDC1 increased mitophagy and cell proliferation while knockdown of FUNDC1 inhibited hypoxia-induced mitophagy and PASMC proliferation. Stimulation of mitophagy by FUNDC1 in PASMCs elevated ROS production and inhibited ubiquitination of hypoxia inducible factor 1α (HIF1α), and inhibition of mitophagy by FUNDC1 knockdown or knockout abolished hypoxia-induced ROS-HIF1α upregulation. Moreover, Fundc1 TG mice developed severe hemodynamics changes and pulmonary vascular remodeling, and Fundc1 KO mice were much resistant to hypoxic PH. In addition, intraperitoneal injection of a specific FUNDC1 peptide inhibitor to block mitophagy ameliorated hypoxic PH. Our results reveal that during hypoxic PH, FUNDC1-mediated mitophagy is upregulated which activates ROS-HIF1α pathway and promotes PASMC proliferation, ultimately leads to pulmonary vascular remodeling and PH.
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Affiliation(s)
- Ruxia Liu
- grid.11135.370000 0001 2256 9319Ministry of Education Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China ,grid.265021.20000 0000 9792 1228Department of Rehabilitation, School of Medical Technology, Tianjin Medical University, Tianjin, China
| | - Chunling Xu
- grid.11135.370000 0001 2256 9319Ministry of Education Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Weilin Zhang
- grid.9227.e0000000119573309State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yangpo Cao
- grid.11135.370000 0001 2256 9319Ministry of Education Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Jingjing Ye
- grid.11135.370000 0001 2256 9319Ministry of Education Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Bo Li
- grid.11135.370000 0001 2256 9319Ministry of Education Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Shi Jia
- grid.11135.370000 0001 2256 9319Ministry of Education Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Lin Weng
- grid.11135.370000 0001 2256 9319Ministry of Education Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Yingying Liu
- grid.11135.370000 0001 2256 9319Ministry of Education Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Lei Liu
- grid.9227.e0000000119573309State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Ming Zheng
- grid.11135.370000 0001 2256 9319Ministry of Education Key Laboratory of Molecular Cardiovascular Science, Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
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9
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Abubakar AA, Ali AK, Ibrahim SM, Handool KO, Khan MS, Mustapha NM, Ibrahim TAT, Kaka U, Yusof LM. Roles of Sodium Hydrogen Exchanger (NHE1) and Anion Exchanger (AE2) across Chondrocytes Plasma Membrane during Longitudinal Bone Growth. MEMBRANES 2022; 12:membranes12070707. [PMID: 35877910 PMCID: PMC9321928 DOI: 10.3390/membranes12070707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/27/2022] [Accepted: 06/30/2022] [Indexed: 12/10/2022]
Abstract
Mammalian long bone growth occurs through endochondral ossification, majorly regulated by the controlled enlargement of chondrocytes at the growth plate (GP). This study aimed to investigate the roles of Na+/H+ (sodium hydrogen exchanger (NHE1)) and HCO3− (anion exchanger [AE2]) during longitudinal bone growth in mammals. Bones from P10 SpragueDawley rat pups were cultured exvivo in the presence or absence of NHE1 and AE2 inhibitors to determine their effect on long bone growth. Gross morphometry, histomorphometry, and immunohistochemistry were used to assess the bone growth. The results revealed that the culture of the bones in the presence of NHE1 and AE2 inhibitors reduces bone growth significantly (p < 0.05) by approximately 11%. The inhibitor significantly (p < 0.05) reduces bone growth velocity and the length of the hypertrophic chondrocyte zone without any effect on the total GP length. The total GP chondrocyte density was significantly (p < 0.05) reduced, but hypertrophic chondrocyte densities remained constant. NHE1 fluorescence signaling across the GP length was higher than AE2, and their localization was significantly (p < 0.05) inhibited at the hypertrophic chondrocytes zone. The GP lengthening was majorly driven by an increase in the overall GP chondrocyte and hypertrophic chondrocyte densities apart from the regulatory volume phenomenon. This may suggest that NHE1 and AE2 could have a regulatory role in long bone growth.
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Affiliation(s)
- Adamu Abdul Abubakar
- Department of Companion Animal Medicine and Surgery, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.A.A.); (A.K.A.); (S.M.I.); (K.O.H.); (M.S.K.); (U.K.)
- Department of Veterinary Surgery and Radiology, Usmanu Danfodiyo University, Sokoto PMB 2346, Nigeria
| | - Ahmed Khalaf Ali
- Department of Companion Animal Medicine and Surgery, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.A.A.); (A.K.A.); (S.M.I.); (K.O.H.); (M.S.K.); (U.K.)
- Department of Surgery and Theriogenology, College of Veterinary Medicine, University of Mosul, Mosul 00964, Iraq
| | - Sahar Mohammed Ibrahim
- Department of Companion Animal Medicine and Surgery, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.A.A.); (A.K.A.); (S.M.I.); (K.O.H.); (M.S.K.); (U.K.)
- Department of Surgery and Theriogenology, College of Veterinary Medicine, University of Mosul, Mosul 00964, Iraq
| | - Kareem Obayes Handool
- Department of Companion Animal Medicine and Surgery, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.A.A.); (A.K.A.); (S.M.I.); (K.O.H.); (M.S.K.); (U.K.)
| | - Mohammad Shuaib Khan
- Department of Companion Animal Medicine and Surgery, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.A.A.); (A.K.A.); (S.M.I.); (K.O.H.); (M.S.K.); (U.K.)
- Faculty of Veterinary and Animal Science, Gomal University, Dera Ismail Khan 29050, Pakistan
| | - Noordin Mohamed Mustapha
- Department of Veterinary Pathology and Microbiology, Universiti Putra Malaysia, Serdang 43400, Malaysia;
| | | | - Ubedullah Kaka
- Department of Companion Animal Medicine and Surgery, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.A.A.); (A.K.A.); (S.M.I.); (K.O.H.); (M.S.K.); (U.K.)
| | - Loqman Mohamad Yusof
- Department of Companion Animal Medicine and Surgery, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.A.A.); (A.K.A.); (S.M.I.); (K.O.H.); (M.S.K.); (U.K.)
- Correspondence: ; Tel.: +60-192-590-571; Fax: +60-386-093-959
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10
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Miao Z, Haider MS, Nazar M, Mansoor MK, Zhang H, Tang Z, Li Y. Potential molecular mechanism of ascites syndrome in broilers. WORLD POULTRY SCI J 2022. [DOI: 10.1080/00439339.2022.2075299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Zhenyan Miao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, GD, China
| | | | - Mudassar Nazar
- Veterinary Sciences, University of Agriculture Faisalabad, Sub-Campus Burewala, Burewala, Pakistan
| | - Muhammad Khalid Mansoor
- Faculty of Veterinary and Animal Sciences, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | - Hui Zhang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, GD, China
| | - Zhaoxin Tang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, GD, China
| | - Ying Li
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, GD, China
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11
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Role of Ion Channel Remodeling in Endothelial Dysfunction Induced by Pulmonary Arterial Hypertension. Biomolecules 2022; 12:biom12040484. [PMID: 35454073 PMCID: PMC9031742 DOI: 10.3390/biom12040484] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 12/12/2022] Open
Abstract
Endothelial dysfunction is a key player in advancing vascular pathology in pulmonary arterial hypertension (PAH), a disease essentially characterized by intense remodeling of the pulmonary vasculature, vasoconstriction, endothelial dysfunction, inflammation, oxidative stress, and thrombosis in situ. These vascular features culminate in an increase in pulmonary vascular resistance, subsequent right heart failure, and premature death. Over the past years, there has been a great development in our understanding of pulmonary endothelial biology related to the genetic and molecular mechanisms that modulate the endothelial response to direct or indirect injury and how their dysregulation can promote PAH pathogenesis. Ion channels are key regulators of vasoconstriction and proliferative/apoptotic phenotypes; however, they are poorly studied at the endothelial level. The current review will describe and categorize different expression, functions, regulation, and remodeling of endothelial ion channels (K+, Ca2+, Na+, and Cl− channels) in PAH. We will focus on the potential pathogenic role of ion channel deregulation in the onset and progression of endothelial dysfunction during the development of PAH and its potential therapeutic role.
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12
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Deschaine B, Verma S, Rayatzadeh H. Clinical Evidence and Proposed Mechanisms of Sodium-Glucose Cotransporter 2 Inhibitors in Heart Failure with Preserved Ejection Fraction: A Class Effect? Card Fail Rev 2022; 8:e23. [PMID: 35846984 PMCID: PMC9272408 DOI: 10.15420/cfr.2022.11] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 04/22/2022] [Indexed: 11/04/2022] Open
Abstract
Effective treatment for heart failure with preserved ejection fraction (HFpEF) is an unmet need in cardiovascular medicine. The pathophysiological drivers of HFpEF are complex, differing depending on phenotype, making a one-size-fits-all treatment approach unlikely. Remarkably, sodium-glucose cotransporter 2 inhibitors (SGLT2is) may be the first drug class to improve cardiovascular outcomes in HFpEF. Randomised controlled trials suggest a benefit in mortality, and demonstrate decreased hospitalisations and improvement in functional status. Limitations in trials exist, either due to small sample sizes, differing results between trials or decreased efficacy at higher ejection fractions. SGLT2is may provide a class effect by targeting various pathophysiological HFpEF mechanisms. Inhibition of SGLT2 and Na+/H+ exchanger 3 in the kidney promotes glycosuria, osmotic diuresis and natriuresis. The glucose deprivation activates sirtuins - protecting against oxidation and beneficially regulating metabolism. SGLT2is reduce excess epicardial adipose tissue and its deleterious adipokines. Na+/H+ exchanger 1 inhibition in the heart and lungs reduces sodium-induced calcium overload and pulmonary hypertension, respectively.
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Affiliation(s)
- Brent Deschaine
- University of Florida College of Medicine Gainesville, FL, US
| | - Sahil Verma
- Florida State University College of Medicine Tallahassee, FL, US
| | - Hussein Rayatzadeh
- Florida State University College of Medicine Tallahassee, FL, US.,Tallahassee Research Institute Tallahassee, FL, US.,Southern Medical Group Tallahassee, FL, US
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13
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Shimoda LA. Cellular Pathways Promoting Pulmonary Vascular Remodeling by Hypoxia. Physiology (Bethesda) 2021; 35:222-233. [PMID: 32490752 DOI: 10.1152/physiol.00039.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Exposure to hypoxia increases pulmonary vascular resistance, leading to elevated pulmonary arterial pressure and, potentially, right heart failure. Vascular remodeling is an important contributor to the increased pulmonary vascular resistance. Hyperproliferation of smooth muscle, endothelial cells, and fibroblasts, and deposition of extracellular matrix lead to increased wall thickness, extension of muscle into normally non-muscular arterioles, and vascular stiffening. This review highlights intrinsic and extrinsic modulators contributing to the remodeling process.
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Affiliation(s)
- Larissa A Shimoda
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland
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14
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Implication of EZH2 in the Pro-Proliferative and Apoptosis-Resistant Phenotype of Pulmonary Artery Smooth Muscle Cells in PAH: A Transcriptomic and Proteomic Approach. Int J Mol Sci 2021; 22:ijms22062957. [PMID: 33803922 PMCID: PMC7999120 DOI: 10.3390/ijms22062957] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 12/13/2022] Open
Abstract
Pulmonary arterial hypertension (PAH) is a progressive disorder characterized by a sustained elevation of pulmonary artery (PA) pressure, right ventricular failure, and premature death. Enhanced proliferation and resistance to apoptosis (as seen in cancer cells) of PA smooth muscle cells (PASMCs) is a major pathological hallmark contributing to pulmonary vascular remodeling in PAH, for which current therapies have only limited effects. Emerging evidence points toward a critical role for Enhancer of Zeste Homolog 2 (EZH2) in cancer cell proliferation and survival. However, its role in PAH remains largely unknown. The aim of this study was to determine whether EZH2 represents a new factor critically involved in the abnormal phenotype of PAH-PASMCs. We found that EZH2 is overexpressed in human lung tissues and isolated PASMCs from PAH patients compared to controls as well as in two animal models mimicking the disease. Through loss- and gain-of-function approaches, we showed that EZH2 promotes PAH-PASMC proliferation and survival. By combining quantitative transcriptomic and proteomic approaches in PAH-PASMCs subjected or not to EZH2 knockdown, we found that inhibition of EZH2 downregulates many factors involved in cell-cycle progression, including E2F targets, and contributes to maintain energy production. Notably, we found that EZH2 promotes expression of several nuclear-encoded components of the mitochondrial translation machinery and tricarboxylic acid cycle genes. Overall, this study provides evidence that, by overexpressing EZH2, PAH-PASMCs remove the physiological breaks that normally restrain their proliferation and susceptibility to apoptosis and suggests that EZH2 or downstream factors may serve as therapeutic targets to combat pulmonary vascular remodeling.
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15
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The Role and Regulation of Pulmonary Artery Smooth Muscle Cells in Pulmonary Hypertension. Int J Hypertens 2020; 2020:1478291. [PMID: 32850144 PMCID: PMC7441461 DOI: 10.1155/2020/1478291] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 07/20/2020] [Indexed: 02/06/2023] Open
Abstract
Pulmonary hypertension (PH) is one of the most devastating cardiovascular diseases worldwide and it draws much attention from numerous scientists. As an indispensable part of pulmonary artery, smooth muscle cells are worthy of being carefully investigated. To elucidate the pathogenesis of PH, several theories focusing on pulmonary artery smooth muscle cells (PASMC), such as hyperproliferation, resistance to apoptosis, and cancer theory, have been proposed and widely studied. Here, we tried to summarize the studies, concentrating on the role of PASMC in the development of PH, feasible molecular basis to intervene, and potential treatment to PH.
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16
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Na +/H + exchanger isoform 1 activity in AQP2-expressing cells can be either proliferative or anti-proliferative depending on extracellular pH. J Physiol Biochem 2019; 76:37-48. [PMID: 31811544 DOI: 10.1007/s13105-019-00713-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 11/06/2019] [Indexed: 10/25/2022]
Abstract
We have previously shown in renal cells that expression of the water channel Aquaporin-2 increases cell proliferation by a regulatory volume mechanism involving Na+/H+ exchanger isoform 2. Here, we investigated if Aquaporin-2 (AQP2) also modulates Na+/H+ exchanger isoform 1-dependent cell proliferation. We use two AQP2-expressing cortical collecting duct models: one constitutive (WT or AQP2-transfected RCCD1 cell line) and one inducible (control or vasopressin-induced mpkCCDc14 cell line). We found that Aquaporin-2 modifies Na+/H+ exchanger isoform 1 (NHE1) contribution to cell proliferation. In Aquaporin-2-expressing cells, Na+/H+ exchanger isoform 1 is anti-proliferative at physiological pH. In acid media, Na+/H+ exchanger isoform 1 contribution turned from anti-proliferative to proliferative only in AQP2-expressing cells. We also found that, in AQP2-expressing cells, NHE1-dependent proliferation changes parallel changes in stress fiber levels: at pH 7.4, Na+/H+ exchanger isoform 1 would favor stress fiber disassembly and, under acidosis, NHE1 would favor stress fiber assembly. Moreover, we found that Na+/H+ exchanger-dependent effects on proliferation linked to Aquaporin-2 relied on Transient Receptor Potential Subfamily V calcium channel activity. In conclusion, our data show that, in collecting duct cells, the water channel Aquaporin-2 modulates NHE1-dependent cell proliferation. In AQP2-expressing cells, at physiological pH, the Na+/H+ exchanger isoform 1 function is anti-proliferative and, at acidic pH, Na+/H+ exchanger isoform 1 function is proliferative. We propose that Na+/H+ exchanger isoform 1 modulates proliferation through an interplay with stress fiber formation.
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17
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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18
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Ramírez MA, Beltrán AR, Araya JE, Cornejo M, Toledo F, Fuentes G, Sobrevia L. Involvement of Intracellular pH in Vascular Insulin Resistance. Curr Vasc Pharmacol 2019; 17:440-446. [DOI: 10.2174/1570161116666180911104012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 08/02/2018] [Accepted: 08/04/2018] [Indexed: 12/25/2022]
Abstract
The maintenance of the pH homeostasis is maintained by several mechanisms including the
efflux of protons (H+) via membrane transporters expressed in almost all mammalian cells. Along these
membrane transporters the sodium/H+ exchangers (NHEs), mainly NHE isoform 1 (NHE1), plays a key
role in this phenomenon. NHE1 is under modulation by several environmental conditions (e.g. hyperglycaemia,
protein kinase C activity) as well as hormones, including insulin. NHE1 activation causes
intracellular alkalization in human endothelial cells leading to activation of the endothelial Nitric Oxide
Synthase (eNOS) to generate NO. Intracellular alkalization is a phenomenon that also results in upregulation
of the glucose transporter GLUT4 in cells that are responsive to insulin. A reduction in the removal
of the extracellular D-glucose is seen in states of insulin resistance, such as in diabetes mellitus
and obesity. Since insulin is a potent activator of eNOS in human endothelium, therefore causing vasodilation,
and its vascular effect is reduced in insulin resistance it is likely that a defective signal to activate
NHE1 in insulin target cells is expected. This phenomenon results in lower redistribution and activation
of GLUT4 leading to reduced uptake of D-glucose and hyperglycaemia. The general concept of a
role for NHE1, and perhaps other NHEs isoforms, in insulin resistance in the human vasculature is proposed.
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Affiliation(s)
- Marco A. Ramírez
- Cellular and Molecular Physiology Laboratory (CMPL), Department of Obstetrics, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontifical Catholic University of Chile, Santiago 8330024, Chile
| | - Ana R. Beltrán
- Laboratorio de Fisiologia Celular, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta 1270300, Chile
| | - Jorge E. Araya
- Laboratorio de Fisiologia Celular, Departamento Biomedico, Facultad de Ciencias de la Salud, Universidad de Antofagasta, Antofagasta 1270300, Chile
| | - Marcelo Cornejo
- Cellular and Molecular Physiology Laboratory (CMPL), Department of Obstetrics, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontifical Catholic University of Chile, Santiago 8330024, Chile
| | - Fernando Toledo
- Cellular and Molecular Physiology Laboratory (CMPL), Department of Obstetrics, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontifical Catholic University of Chile, Santiago 8330024, Chile
| | - Gonzalo Fuentes
- Cellular and Molecular Physiology Laboratory (CMPL), Department of Obstetrics, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontifical Catholic University of Chile, Santiago 8330024, Chile
| | - Luis Sobrevia
- Cellular and Molecular Physiology Laboratory (CMPL), Department of Obstetrics, Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontifical Catholic University of Chile, Santiago 8330024, Chile
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19
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Stenmark KR, Frid MG, Graham BB, Tuder RM. Dynamic and diverse changes in the functional properties of vascular smooth muscle cells in pulmonary hypertension. Cardiovasc Res 2019; 114:551-564. [PMID: 29385432 DOI: 10.1093/cvr/cvy004] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 01/26/2018] [Indexed: 12/21/2022] Open
Abstract
Pulmonary hypertension (PH) is the end result of interaction between pulmonary vascular tone and a complex series of cellular and molecular events termed 'vascular remodelling'. The remodelling process, which can involve the entirety of pulmonary arterial vasculature, almost universally involves medial thickening, driven by increased numbers and hypertrophy of its principal cellular constituent, smooth muscle cells (SMCs). It is noted, however that SMCs comprise heterogeneous populations of cells, which can exhibit markedly different proliferative, inflammatory, and extracellular matrix production changes during remodelling. We further consider that these functional changes in SMCs of different phenotype and their role in PH are dynamic and may undergo significant changes over time (which we will refer to as cellular plasticity); no single property can account for the complexity of the contribution of SMC to pulmonary vascular remodelling. Thus, the approaches used to pharmacologically manipulate PH by targeting the SMC phenotype(s) must take into account processes that underlie dominant phenotypes that drive the disease. We present evidence for time- and location-specific changes in SMC proliferation in various animal models of PH; we highlight the transient nature (rather than continuous) of SMC proliferation, emphasizing that the heterogenic SMC populations that reside in different locations along the pulmonary vascular tree exhibit distinct responses to the stresses associated with the development of PH. We also consider that cells that have often been termed 'SMCs' may arise from many origins, including endothelial cells, fibroblasts and resident or circulating progenitors, and thus may contribute via distinct signalling pathways to the remodelling process. Ultimately, PH is characterized by long-lived, apoptosis-resistant SMC. In line with this key pathogenic characteristic, we address the acquisition of a pro-inflammatory phenotype by SMC that is essential to the development of PH. We present evidence that metabolic alterations akin to those observed in cancer cells (cytoplasmic and mitochondrial) directly contribute to the phenotype of the SM and SM-like cells involved in PH. Finally, we raise the possibility that SMCs transition from a proliferative to a senescent, pro-inflammatory and metabolically active phenotype over time.
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Affiliation(s)
- Kurt R Stenmark
- Cardiovascular Pulmonary Research Laboratories, Departments of Pediatrics and Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Avenue, RC2, B131, Aurora, CO 80045, USA
| | - Maria G Frid
- Cardiovascular Pulmonary Research Laboratories, Departments of Pediatrics and Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Avenue, RC2, B131, Aurora, CO 80045, USA
| | - Brian B Graham
- Pulmonary and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Avenue, RC2, B131, Aurora, CO 80045, USA
| | - Rubin M Tuder
- Pulmonary and Critical Care Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, 12700 E. 19th Avenue, RC2, B131, Aurora, CO 80045, USA
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Huetsch JC, Walker J, Undem C, Lade J, Yun X, Baksh S, Jiang H, Lai N, Shimoda LA. Rho kinase and Na + /H + exchanger mediate endothelin-1-induced pulmonary arterial smooth muscle cell proliferation and migration. Physiol Rep 2019; 6:e13698. [PMID: 29756391 PMCID: PMC5949284 DOI: 10.14814/phy2.13698] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 04/05/2018] [Accepted: 04/07/2018] [Indexed: 01/04/2023] Open
Abstract
Excessive production of endothelin‐1 (ET‐1) has been observed in almost all forms of pulmonary hypertension. ET‐1, a highly potent vasoconstrictor, can also potentiate pulmonary arterial smooth muscle cell (PASMC) growth and migration, both of which contribute to the vascular remodeling that occurs during the development of pulmonary hypertension. Increasing evidence indicates that alkalinization of intracellular pH (pHi), typically due to activation of Na+/H+ exchange (NHE), is associated with enhanced PASMC proliferation and migration. We recently demonstrated that application of exogenous ET‐1 increased NHE activity in murine PASMCs via a mechanism requiring Rho kinase (ROCK). However, whether ROCK and/or increased NHE activity mediate ET‐1‐induced migration and proliferation in PASMCs remains unknown. In this study, we used fluorescent microscopy in transiently cultured PASMCs from distal pulmonary arteries of the rat and the pH‐sensitive dye, BCECF‐AM, to measure changes in resting pHi and NHE activity induced by exposure to exogenous ET‐1 (10−8 mol/L) for 24 h. Cell migration and proliferation in response to ET‐1 were also measured using Transwell assays and BrdU incorporation, respectively. We found that application of exogenous ET‐1 had no effect on NHE1 expression, but increased pHi, NHE activity, migration, and proliferation in rat PASMCs. Pharmacologic inhibition of NHE or ROCK prevented the ET‐1‐induced changes in cell function (proliferation and migration). Our results indicate that ET‐1 modulates PASMC migration and proliferation via changes in pHi homeostasis through a pathway involving ROCK.
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Affiliation(s)
- John C Huetsch
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Jasmine Walker
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Clark Undem
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Julie Lade
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Xin Yun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Syeda Baksh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Haiyang Jiang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Ning Lai
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD
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Boedtkjer E. Acid-base regulation and sensing: Accelerators and brakes in metabolic regulation of cerebrovascular tone. J Cereb Blood Flow Metab 2018; 38:588-602. [PMID: 28984162 PMCID: PMC5888856 DOI: 10.1177/0271678x17733868] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/10/2017] [Accepted: 09/06/2017] [Indexed: 12/29/2022]
Abstract
Metabolic regulation of cerebrovascular tone directs blood flow to areas of increased neuronal activity and during disease states partially compensates for insufficient perfusion by enhancing blood flow in collateral blood vessels. Acid-base disturbances frequently occur as result of enhanced metabolism or insufficient blood supply, but despite definitive evidence that acid-base disturbances alter arterial tone, effects of individual acid-base equivalents and the underlying signaling mechanisms are still being debated. H+ is an important intra- and extracellular messenger that modifies cerebrovascular tone. In addition, low extracellular [HCO3-] promotes cerebrovascular contraction through an endothelium-dependent mechanism. CO2 alters arterial tone development via changes in intra- and extracellular pH but it is still controversial whether CO2 also has direct vasomotor effects. Vasocontractile responses to low extracellular [HCO3-] and acute CO2-induced decreases in intracellular pH can counteract H+-mediated vasorelaxation during metabolic and respiratory acidosis, respectively, and may thereby reduce the risk of capillary damage and cerebral edema that could be consequences of unopposed vasodilation. In this review, the signaling mechanisms for acid-base equivalents in cerebral arteries and the mechanisms of intracellular pH control in the arterial wall are discussed in the context of metabolic regulation of cerebrovascular tone and local perfusion.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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Dysregulated expression of microRNAs and mRNAs in pulmonary artery remodeling in ascites syndrome in broiler chickens. Oncotarget 2018; 8:1993-2007. [PMID: 27791988 PMCID: PMC5356772 DOI: 10.18632/oncotarget.12888] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 10/19/2016] [Indexed: 12/31/2022] Open
Abstract
Ascites syndrome (AS), also known as pulmonary artery hypertension, remains a challenging disease that severely affects both humans and broiler chickens. Pulmonary artery remodeling presents a key step in the development of AS. In this study, we obtained pulmonary artery tissues from broilers with and without AS to perform miRNA sequencing analysis, miRNA-mRNA association analysis and pathological examinations. 29 significantly differentially expressed miRNAs were found both in known and novel miRNAs with 18 up-regulated and 11 down-regulated miRNAs. Their predicted potential targets were involved in a wide range of functional clusters as indicated via GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses. The upregulation of miR-155, miR-23b-3p, miR-146b-5p and miR-146b-3p were found closely associated with the pathogenesis of pulmonary artery remodeling in AS progression. The association analysis for the miRNAs-mRNAs showed that these 29 significantly differentially expressed miRNAs regulate 162 differentially expressed target genes. Among them, 20 miRNAs correlated with 18 predicted target genes that appear to be involved in pulmonary artery remodeling, mainly in three broad physiological processes: the hypoxia sensing response (HIF1α, NHE1, STAT5 and STAT3), endothelial permeability dysfunction (CD44, TRAF2, CDK2AP1, LZTFL1, JAZF1, PEBP1, LRP1B, RPS14 and THBS2) and inflammation (MEOX2, STAT5, STAT3, IRF8, MAP3K8, IL-1BETA and TNFRSF1B). Pathological pulmonary artery remodeling in the AS broilers was consistently observed in the present study. Taken together, the current analysis further illuminates the molecular mechanism of pulmonary artery remodeling underlying AS progression.
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PEGylation of the GALA Peptide Enhances the Lung-Targeting Activity of Nanocarriers That Contain Encapsulated siRNA. J Pharm Sci 2017; 106:2420-2427. [DOI: 10.1016/j.xphs.2017.04.075] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 04/07/2017] [Accepted: 04/19/2017] [Indexed: 11/19/2022]
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Maron BA, Machado RF, Shimoda L. Pulmonary vascular and ventricular dysfunction in the susceptible patient (2015 Grover Conference series). Pulm Circ 2016; 6:426-438. [PMID: 28090285 PMCID: PMC5210067 DOI: 10.1086/688315] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 06/21/2016] [Indexed: 12/14/2022] Open
Abstract
Pulmonary blood vessel structure and tone are maintained by a complex interplay between endogenous vasoactive factors and oxygen-sensing intermediaries. Under physiological conditions, these signaling networks function as an adaptive interface between the pulmonary circulation and environmental or acquired perturbations to preserve oxygenation and maintain systemic delivery of oxygen-rich hemoglobin. Chronic exposure to hypoxia, however, triggers a range of pathogenetic mechanisms that include hypoxia-inducible factor 1α (HIF-1α)-dependent upregulation of the vasoconstrictor peptide endothelin 1 in pulmonary endothelial cells. In pulmonary arterial smooth muscle cells, chronic hypoxia induces HIF-1α-mediated upregulation of canonical transient receptor potential proteins, as well as increased Rho kinase-Ca2+ signaling and pulmonary arteriole synthesis of the profibrotic hormone aldosterone. Collectively, these mechanisms contribute to a contractile or hypertrophic pulmonary vascular phenotype. Genetically inherited disorders in hemoglobin structure are also an important etiology of abnormal pulmonary vasoreactivity. In sickle cell anemia, for example, consumption of the vasodilator and antimitogenic molecule nitric oxide by cell-free hemoglobin is an important mechanism underpinning pulmonary hypertension. Contemporary genomic and transcriptomic analytic methods have also allowed for the discovery of novel risk factors relevant to sickle cell disease, including GALNT13 gene variants. In this report, we review cutting-edge observations characterizing these and other pathobiological mechanisms that contribute to pulmonary vascular and right ventricular vulnerability.
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Affiliation(s)
- Bradley A. Maron
- Division of Cardiovascular Medicine, Brigham and Women’s Hospital, Boston, Massachusetts, USA; and Department of Cardiology, Boston Veterans Affairs Healthcare System, Boston, Massachusetts, USA
| | - Roberto F. Machado
- Division of Pulmonary, Critical Care Medicine, Sleep and Allergy, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Larissa Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Asthma and Allergy Center, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Walker J, Undem C, Yun X, Lade J, Jiang H, Shimoda LA. Role of Rho kinase and Na+/H+ exchange in hypoxia-induced pulmonary arterial smooth muscle cell proliferation and migration. Physiol Rep 2016; 4:4/6/e12702. [PMID: 27009277 PMCID: PMC4814889 DOI: 10.14814/phy2.12702] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 01/17/2016] [Indexed: 12/21/2022] Open
Abstract
Abnormal proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs) are hallmark characteristics of vascular remodeling in pulmonary hypertension induced by chronic hypoxia. In this study, we investigated the role of the Na+/H+ exchanger (NHE) and alterations in intracellular pH (pHi) homeostasis in meditating increased proliferation and migration in PASMCs isolated from resistance‐sized pulmonary arteries from chronically hypoxic rats or from normoxic rats that were exposed to hypoxia ex vivo (1% or 4% O2, 24–96 h). We found that PASMCs exposed to either in vivo or ex vivo hypoxia exhibited greater proliferative and migratory capacity, elevated pHi, and enhanced NHE activity. The NHE inhibitor, ethyl isopropyl amiloride (EIPA), normalized pHi in hypoxic PASMCs and reduced migration by 73% and 45% in cells exposed to in vivo and in vitro hypoxia, respectively. Similarly, EIPA reduced proliferation by 97% and 78% in cells exposed to in vivo and in vitro hypoxia, respectively. We previously demonstrated that NHE isoform 1 (NHE1) is the predominant isoform expressed in PASMCs. The development of hypoxia‐induced pulmonary hypertension and alterations in PASMC pHi homeostasis were prevented in mice deficient for NHE1. We found that short‐term (24 h) ex vivo hypoxic exposure did not alter the expression of NHE1, so we tested the role of Rho kinase (ROCK) as a possible means of increasing NHE activity. In the presence of the ROCK inhibitor, Y‐27632, we found that pHi and NHE activity were normalized and migration and proliferation were reduced in PASMCs exposed to either in vivo (by 68% for migration and 22% for proliferation) or ex vivo (by 43% for migration and 17% for proliferation) hypoxia. From these results, we conclude that during hypoxia, activation of ROCK enhances NHE activity and promotes PASMC migration and proliferation.
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Affiliation(s)
- Jasmine Walker
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Clark Undem
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Xin Yun
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Julie Lade
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Haiyang Jiang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
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Huetsch JC, Jiang H, Larrain C, Shimoda LA. The Na+/H+ exchanger contributes to increased smooth muscle proliferation and migration in a rat model of pulmonary arterial hypertension. Physiol Rep 2016; 4:4/5/e12729. [PMID: 26997630 PMCID: PMC4823603 DOI: 10.14814/phy2.12729] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Increased muscularity of small pulmonary vessels, involving enhanced proliferation and migration of pulmonary arterial smooth muscle cells (PASMCs), is a key component of the vascular remodeling underlying the development of pulmonary hypertension (PH). Stimuli such as growth factors and hypoxia induce PASMC alkalinization, proliferation, and migration through upregulation of the Na+/H+ exchanger (NHE), inhibition of which prevents the development of hypoxia‐induced vascular remodeling and PH. We wanted to explore whether NHE was also necessary for pathologic PASMC proliferation and migration in a model of pulmonary arterial hypertension (PAH), a severe form of PH not associated with persistent hypoxia. PASMCs were isolated from rats exposed to SU5416‐hypoxia (SuHx) followed by return to normoxia and from vehicle controls. We measured resting intracellular pH (pHi) and NHE activity using the pH‐sensitive fluorescent dye BCECF‐AM. PASMC proliferation and migration were assessed using BrdU incorporation and transwell filters, respectively. NHE activity was increased in SuHx PASMCs, although resting pHi was unchanged. SuHx PASMCs also exhibited increased proliferation and migration relative to controls, which was attenuated in the setting of pharmacologic inhibition of NHE. Our findings suggest that increased NHE activity contributes to pathologic PASMC function in the SuHx model of PAH, although this effect does not appear to be mediated by global changes in pHi homeostasis.
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Affiliation(s)
- John C Huetsch
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Haiyang Jiang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Carolina Larrain
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
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27
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Undem C, Luke T, Shimoda LA. Contribution of elevated intracellular calcium to pulmonary arterial myocyte alkalinization during chronic hypoxia. Pulm Circ 2016; 6:93-102. [PMID: 27076907 PMCID: PMC4809666 DOI: 10.1086/685053] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In the lung, exposure to chronic hypoxia (CH) causes pulmonary hypertension, a debilitating disease. Development of this condition arises from increased muscularity and contraction of pulmonary vessels, associated with increases in pulmonary arterial smooth muscle cell (PASMC) intracellular pH (pHi) and Ca(2+) concentration ([Ca(2+)]i). In this study, we explored the interaction between pHi and [Ca(2+)]i in PASMCs from rats exposed to normoxia or CH (3 weeks, 10% O2). PASMC pHi and [Ca(2+)]i were measured with fluorescent microscopy and the dyes BCECF and Fura-2. Both pHi and [Ca(2+)]i levels were elevated in PASMCs from hypoxic rats. Exposure to KCl increased [Ca(2+)]i and pHi to a similar extent in normoxic and hypoxic PASMCs. Conversely, removal of extracellular Ca(2+) or blockade of Ca(2+) entry with NiCl2 or SKF 96365 decreased [Ca(2+)]i and pHi only in hypoxic cells. Neither increasing pHi with NH4Cl nor decreasing pHi by removal of bicarbonate impacted PASMC [Ca(2+)]i. We also examined the roles of Na(+)/Ca(2+) exchange (NCX) and Na(+)/H(+) exchange (NHE) in mediating the elevated basal [Ca(2+)]i and Ca(2+)-dependent changes in PASMC pHi. Bepridil, dichlorobenzamil, and KB-R7943, which are NCX inhibitors, decreased resting [Ca(2+)]i and pHi only in hypoxic PASMCs and blocked the changes in pHi induced by altering [Ca(2+)]i. Exposure to ethyl isopropyl amiloride, an NHE inhibitor, decreased resting pHi and prevented changes in pHi due to changing [Ca(2+)]i. Our findings indicate that, during CH, the elevation in basal [Ca(2+)]i may contribute to the alkaline shift in pHi in PASMCs, likely via mechanisms involving reverse-mode NCX and NHE.
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Affiliation(s)
- Clark Undem
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Trevor Luke
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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Boedtkjer E, Bentzon JF, Dam VS, Aalkjaer C. Na+, HCO3--cotransporter NBCn1 increases pHi gradients, filopodia, and migration of smooth muscle cells and promotes arterial remodelling. Cardiovasc Res 2016; 111:227-39. [PMID: 27076468 DOI: 10.1093/cvr/cvw079] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 03/17/2016] [Indexed: 12/19/2022] Open
Abstract
AIMS Arterial remodelling can cause luminal narrowing and obstruct blood flow. We tested the hypothesis that cellular acid-base transport facilitates proliferation and migration of vascular smooth muscle cells (VSMCs) and enhances remodelling of conduit arteries. METHODS AND RESULTS [Formula: see text]-cotransport via NBCn1 (Slc4a7) mediates net acid extrusion and controls steady-state intracellular pH (pHi) in VSMCs of mouse carotid arteries and primary aortic explants. Carotid arteries undergo hypertrophic inward remodelling in response to partial or complete ligation in vivo, but the increase in media area and thickness and reduction in lumen diameter are attenuated in arteries from NBCn1 knock-out compared with wild-type mice. With [Formula: see text] present, gradients for pHi (∼0.2 units magnitude) exist along the axis of VSMC migration in primary explants from wild-type but not NBCn1 knock-out mice. Knock-out or pharmacological inhibition of NBCn1 also reduces filopodia and lowers initial rates of VSMC migration after scratch-wound infliction. Interventions to reduce H(+)-buffer mobility (omission of [Formula: see text] or inhibition of carbonic anhydrases) re-establish axial pHi gradients, filopodia, and migration rates in explants from NBCn1 knock-out mice. The omission of [Formula: see text] also lowers global pHi and inhibits proliferation in primary explants. CONCLUSION Under physiological conditions (i.e. with [Formula: see text] present), NBCn1-mediated [Formula: see text] uptake raises VSMC pHi and promotes filopodia, VSMC migration, and hypertrophic inward remodelling. We propose that axial pHi gradients enhance VSMC migration whereas global acidification inhibits VSMC proliferation and media hypertrophy after carotid artery ligation. These findings support a key role of acid-base transport, particularly via NBCn1, for development of occlusive artery disease.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Ole Worms Allé 3, Building 1170, DK-8000 Aarhus C, Denmark
| | - Jacob F Bentzon
- Department of Clinical Medicine, Aarhus University, Aarhus C, Denmark
| | - Vibeke S Dam
- Department of Biomedicine, Aarhus University, Ole Worms Allé 3, Building 1170, DK-8000 Aarhus C, Denmark
| | - Christian Aalkjaer
- Department of Biomedicine, Aarhus University, Ole Worms Allé 3, Building 1170, DK-8000 Aarhus C, Denmark
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Abstract
The circulation of the lung is unique both in volume and function. For example, it is the only organ with two circulations: the pulmonary circulation, the main function of which is gas exchange, and the bronchial circulation, a systemic vascular supply that provides oxygenated blood to the walls of the conducting airways, pulmonary arteries and veins. The pulmonary circulation accommodates the entire cardiac output, maintaining high blood flow at low intravascular arterial pressure. As compared with the systemic circulation, pulmonary arteries have thinner walls with much less vascular smooth muscle and a relative lack of basal tone. Factors controlling pulmonary blood flow include vascular structure, gravity, mechanical effects of breathing, and the influence of neural and humoral factors. Pulmonary vascular tone is also altered by hypoxia, which causes pulmonary vasoconstriction. If the hypoxic stimulus persists for a prolonged period, contraction is accompanied by remodeling of the vasculature, resulting in pulmonary hypertension. In addition, genetic and environmental factors can also confer susceptibility to development of pulmonary hypertension. Under normal conditions, the endothelium forms a tight barrier, actively regulating interstitial fluid homeostasis. Infection and inflammation compromise normal barrier homeostasis, resulting in increased permeability and edema formation. This article focuses on reviewing the basics of the lung circulation (pulmonary and bronchial), normal development and transition at birth and vasoregulation. Mechanisms contributing to pathological conditions in the pulmonary circulation, in particular when barrier function is disrupted and during development of pulmonary hypertension, will also be discussed.
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Affiliation(s)
- Karthik Suresh
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Larissa A. Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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30
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Huetsch J, Shimoda LA. Na(+)/H(+) exchange and hypoxic pulmonary hypertension. Pulm Circ 2015; 5:228-43. [PMID: 26064449 DOI: 10.1086/680213] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 07/22/2014] [Indexed: 12/24/2022] Open
Abstract
Intracellular pH (pHi) homeostasis is key to the functioning of vascular smooth muscle cells, including pulmonary artery smooth muscle cells (PASMCs). Sodium-hydrogen exchange (NHE) is an important contributor to pHi control in PASMCs. In this review, we examine the role of NHE in PASMC function, in both physiologic and pathologic conditions. In particular, we focus on the contribution of NHE to the PASMC response to hypoxia, considering both acute hypoxic pulmonary vasoconstriction and the development of pulmonary vascular remodeling and pulmonary hypertension in response to chronic hypoxia. Hypoxic pulmonary hypertension remains a disease with limited therapeutic options. Thus, this review explores past efforts at disrupting NHE signaling and discusses the therapeutic potential that such efforts may have in the field of pulmonary hypertension.
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Affiliation(s)
- John Huetsch
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, USA
| | - Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21224, USA
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31
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Pugliese SC, Poth JM, Fini MA, Olschewski A, El Kasmi KC, Stenmark KR. The role of inflammation in hypoxic pulmonary hypertension: from cellular mechanisms to clinical phenotypes. Am J Physiol Lung Cell Mol Physiol 2014; 308:L229-52. [PMID: 25416383 DOI: 10.1152/ajplung.00238.2014] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Hypoxic pulmonary hypertension (PH) comprises a heterogeneous group of diseases sharing the common feature of chronic hypoxia-induced pulmonary vascular remodeling. The disease is usually characterized by mild to moderate pulmonary vascular remodeling that is largely thought to be reversible compared with the progressive irreversible disease seen in World Health Organization (WHO) group I disease. However, in these patients, the presence of PH significantly worsens morbidity and mortality. In addition, a small subset of patients with hypoxic PH develop "out-of-proportion" severe pulmonary hypertension characterized by pulmonary vascular remodeling that is irreversible and similar to that in WHO group I disease. In all cases of hypoxia-related vascular remodeling and PH, inflammation, particularly persistent inflammation, is thought to play a role. This review focuses on the effects of hypoxia on pulmonary vascular cells and the signaling pathways involved in the initiation and perpetuation of vascular inflammation, especially as they relate to vascular remodeling and transition to chronic irreversible PH. We hypothesize that the combination of hypoxia and local tissue factors/cytokines ("second hit") antagonizes tissue homeostatic cellular interactions between mesenchymal cells (fibroblasts and/or smooth muscle cells) and macrophages and arrests these cells in an epigenetically locked and permanently activated proremodeling and proinflammatory phenotype. This aberrant cellular cross-talk between mesenchymal cells and macrophages promotes transition to chronic nonresolving inflammation and vascular remodeling, perpetuating PH. A better understanding of these signaling pathways may lead to the development of specific therapeutic targets, as none are currently available for WHO group III disease.
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Affiliation(s)
- Steven C Pugliese
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado;
| | - Jens M Poth
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Mehdi A Fini
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
| | - Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; and
| | - Karim C El Kasmi
- Department of Pediatrics, Division of Gastroenterology, Hepatology, and Nutrition, University of Colorado Denver, School of Medicine, Anschutz Medical Campus, Aurora, Colorado
| | - Kurt R Stenmark
- Developmental Lung Biology, Cardiovascular Pulmonary Research Laboratories, Division of Pulmonary Sciences and Critical Care Medicine, Division of Pediatrics-Critical Care, Departments of Medicine and Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, Colorado
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Xu L, Chen Y, Yang K, Wang Y, Tian L, Zhang J, Wang EW, Sun D, Lu W, Wang J. Chronic hypoxia increases TRPC6 expression and basal intracellular Ca2+ concentration in rat distal pulmonary venous smooth muscle. PLoS One 2014; 9:e112007. [PMID: 25365342 PMCID: PMC4218830 DOI: 10.1371/journal.pone.0112007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 10/11/2014] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Hypoxia causes remodeling and contractile responses in both pulmonary artery (PA) and pulmonary vein (PV). Here we explore the effect of hypoxia on PV and pulmonary venous smooth muscle cells (PVSMCs). METHODS Chronic hypoxic pulmonary hypertension (CHPH) model was established by exposing rats to 10% O2 for 21 days. Rat distal PVSMCs were isolated and cultured for in vitro experiments. The fura-2 based fluorescence calcium imaging was used to measure the basal intracellular Ca2+ concentration ([Ca2+]i) and store-operated Ca2+ entry (SOCE). Quantitative RT-PCR and western blotting were performed to measure the expression of mRNA and levels of canonical transient receptor potential (TRPC) protein respectively. RESULTS Hypoxia increased the basal [Ca2+]i and SOCE in both freshly dissociated and serum cultured distal PVSMCs. Moreover, hypoxia increased TRPC6 expression at mRNA and protein levels in both cultured PVSMCs exposed to prolonged hypoxia (4% O2, 60 h) and distal PV isolated from CHPH rats. Hypoxia also enhanced proliferation and migration of rat distal PVSMCs. CONCLUSIONS Hypoxia induces elevation of SOCE in distal PVSMCs, leading to enhancement of basal [Ca2+]i in PVSMCs. This enhancement is potentially correlated with the increased expression of TRPC6. Hypoxia triggered intracellular calcium contributes to promoted proliferation and migration of PVSMCs.
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Affiliation(s)
- Lei Xu
- Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Division of Pulmonary and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Yuqin Chen
- Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Kai Yang
- Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Division of Pulmonary and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Yingfeng Wang
- Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Lichun Tian
- Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Jie Zhang
- Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | | | - Dejun Sun
- Division of Pulmonary and Critical Care Medicine, Inner Mongolia People's Hospital, Huhhot, Inner Mongolia, China
| | - Wenju Lu
- Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Division of Pulmonary and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail: (WL); (JW)
| | - Jian Wang
- Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
- Division of Pulmonary and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America
- Division of Pulmonary and Critical Care Medicine, Inner Mongolia People's Hospital, Huhhot, Inner Mongolia, China
- * E-mail: (WL); (JW)
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de Jesus Perez VA, Yuan K, Lyuksyutova MA, Dewey F, Orcholski ME, Shuffle EM, Mathur M, Yancy L, Rojas V, Li CG, Cao A, Alastalo TP, Khazeni N, Cimprich KA, Butte AJ, Ashley E, Zamanian RT. Whole-exome sequencing reveals TopBP1 as a novel gene in idiopathic pulmonary arterial hypertension. Am J Respir Crit Care Med 2014; 189:1260-72. [PMID: 24702692 DOI: 10.1164/rccm.201310-1749oc] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Idiopathic pulmonary arterial hypertension (IPAH) is a life-threatening disorder characterized by progressive loss of pulmonary microvessels. Although mutations in the bone morphogenetic receptor 2 (BMPR2) are found in 80% of heritable and ∼15% of patients with IPAH, their low penetrance (∼20%) suggests that other unidentified genetic modifiers are required for manifestation of the disease phenotype. Use of whole-exome sequencing (WES) has recently led to the discovery of novel susceptibility genes in heritable PAH, but whether WES can also accelerate gene discovery in IPAH remains unknown. OBJECTIVES To determine whether WES can help identify novel gene modifiers in patients with IPAH. METHODS Exome capture and sequencing was performed on genomic DNA isolated from 12 unrelated patients with IPAH lacking BMPR2 mutations. Observed genetic variants were prioritized according to their pathogenic potential using ANNOVAR. MEASUREMENTS AND MAIN RESULTS A total of nine genes were identified as high-priority candidates. Our top hit was topoisomerase DNA binding II binding protein 1 (TopBP1), a gene involved in the response to DNA damage and replication stress. We found that TopBP1 expression was reduced in vascular lesions and pulmonary endothelial cells isolated from patients with IPAH. Although TopBP1 deficiency made endothelial cells susceptible to DNA damage and apoptosis in response to hydroxyurea, its restoration resulted in less DNA damage and improved cell survival. CONCLUSIONS WES led to the discovery of TopBP1, a gene whose deficiency may increase susceptibility to small vessel loss in IPAH. We predict that use of WES will help identify gene modifiers that influence an individual's risk of developing IPAH.
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Lai N, Lade J, Leggett K, Yun X, Baksh S, Chau E, Crow MT, Sidhaye V, Wang J, Shimoda LA. The aquaporin 1 C-terminal tail is required for migration and growth of pulmonary arterial myocytes. Am J Respir Cell Mol Biol 2014; 50:1010-20. [PMID: 24328827 DOI: 10.1165/rcmb.2013-0374oc] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Pulmonary arterial smooth muscle cell (PASMC) proliferation and migration are important contributors to the vascular remodeling that occurs during development of pulmonary hypertension. We previously demonstrated that aquaporin (AQP)1, a member of the water channel family of proteins, was expressed in PASMCs and was necessary for hypoxia-induced migration; however, the mechanism by which AQP1 controls this response is unclear. The C-terminal tail of AQP1 contains putative calcium (EF-hand) and protein binding sites. Thus, we wanted to explore whether the C-terminal tail or the EF-hand motif of AQP1 was required for migration and proliferation. Rat PASMCs were isolated from distal pulmonary arteries, and proliferation and migration were measured using BrdU incorporation and transwell filters, respectively. To deplete AQP1, PASMCs were transfected with AQP1 small interference RNA (siRNA) or nontargeting siRNA. Knockdown of AQP1 reduced basal proliferation and hypoxia-induced migration and proliferation in PASMCs. In subsequent experiments, wild-type AQP1, AQP1 lacking the entire cytoplasmic C-terminal tail, or AQP1 with a mutation in the EF-hand motif were expressed in PASMCs using adenoviral constructs. For all AQP1 constructs, infection increased AQP1 protein levels, water permeability, and the change in cell volume induced by hypotonic challenge. Infection with wild-type and EF-hand mutated AQP1, but not C-terminal-deleted AQP1, increased PASMC migration and proliferation. Our results suggest that AQP1 controls proliferation and migration in PASMCs and that the mechanism requires the C-terminal tail of the protein but is independent of water transport or the EF-hand motif.
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Affiliation(s)
- Ning Lai
- 1 Guangzhou Institute of Respiratory Diseases, State Key Laboratory of Respiratory Diseases, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, People's Republic of China; and
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Abstract
In the lung, acute reductions in oxygen lead to hypoxic pulmonary vasoconstriction, whereas prolonged exposures to hypoxia result in sustained vasoconstriction, pulmonary vascular remodeling, and the development of pulmonary hypertension. Data from both human subjects and animal models implicate a role for hypoxia-inducible factors (HIFs), oxygen-sensitive transcription factors, in pulmonary vascular responses to both acute and chronic hypoxia. In this review, we discuss work from our laboratory and others supporting a role for HIF in modulating hypoxic pulmonary vasoconstriction and mediating hypoxia-induced pulmonary hypertension, identify some of the downstream targets of HIF, and assess the potential to pharmacologically target the HIF system.
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Affiliation(s)
- Larissa A Shimoda
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
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36
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Shi Y, Yuan H, Kim D, Chanana V, Baba A, Matsuda T, Cengiz P, Ferrazzano P, Sun D. Stimulation of Na(+)/H(+) exchanger isoform 1 promotes microglial migration. PLoS One 2013; 8:e74201. [PMID: 23991215 PMCID: PMC3749130 DOI: 10.1371/journal.pone.0074201] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 07/29/2013] [Indexed: 11/18/2022] Open
Abstract
Regulation of microglial migration is not well understood. In this study, we proposed that Na(+)/H(+) exchanger isoform 1 (NHE-1) is important in microglial migration. NHE-1 protein was co-localized with cytoskeletal protein ezrin in lamellipodia of microglia and maintained its more alkaline intracellular pH (pHi). Chemoattractant bradykinin (BK) stimulated microglial migration by increasing lamellipodial area and protrusion rate, but reducing lamellipodial persistence time. Interestingly, blocking NHE-1 activity with its potent inhibitor HOE 642 not only acidified microglia, abolished the BK-triggered dynamic changes of lamellipodia, but also reduced microglial motility and microchemotaxis in response to BK. In addition, NHE-1 activation resulted in intracellular Na(+) loading as well as intracellular Ca(2+) elevation mediated by stimulating reverse mode operation of Na(+)/Ca(2+) exchange (NCXrev). Taken together, our study shows that NHE-1 protein is abundantly expressed in microglial lamellipodia and maintains alkaline pHi in response to BK stimulation. In addition, NHE-1 and NCXrev play a concerted role in BK-induced microglial migration via Na(+) and Ca(2+) signaling.
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Affiliation(s)
- Yejie Shi
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Neuroscience Training Program, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Hui Yuan
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Dong Kim
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Vishal Chanana
- Waisman Center, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Akemichi Baba
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Toshio Matsuda
- Graduate School of Pharmaceutical Sciences, Osaka University, Osaka, Japan
| | - Pelin Cengiz
- Waisman Center, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Peter Ferrazzano
- Waisman Center, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
- Neuroscience Training Program, University of Wisconsin, Madison, Wisconsin, United States of America
- Department of Neurological Surgery, University of Wisconsin, Madison, Wisconsin, United States of America
- * E-mail:
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Yang Y, Sun F, Zhang C, Wang H, Wu G, Wu Z. Hypoxia promotes cell proliferation by modulating E2F1 in chicken pulmonary arterial smooth muscle cells. J Anim Sci Biotechnol 2013; 4:28. [PMID: 23902684 PMCID: PMC3765561 DOI: 10.1186/2049-1891-4-28] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Accepted: 07/30/2013] [Indexed: 11/10/2022] Open
Abstract
In this study, we sought to investigate the expression of the transcription factor E2F1 in chicken pulmonary arterial smooth muscle cells upon hypoxia exposure, as well as the role that E2F1 played in the regulation of cell proliferation. Isolated chicken pulmonary arterial smooth muscle cells were subjected to hypoxia or normoxia for indicated time points. Cell viability, DNA synthesis, cell cycle profile, and expression of E2F1 were analyzed. The results showed that hypoxia promoted cell proliferation and DNA synthesis which was accompanied by an increased S phase entry and upregulation of E2F1 at mRNA and protein levels. Using siRNA technology, we demonstrated that gene inactivation of endogenous E2F1 abolished hypoxia-induced cell proliferation, DNA synthesis, and S phase entry compared with negative siRNA transfected cells. These results suggest that hypoxia-induced proliferation is mediated by inducing E2F1 in chicken pulmonary arterial smooth muscle cells.
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Affiliation(s)
- Ying Yang
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, P,R, China.
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38
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Loqman MY, Bush PG, Farquharson C, Hall AC. Suppression of mammalian bone growth by membrane transport inhibitors. J Cell Biochem 2013; 114:658-68. [PMID: 23059814 DOI: 10.1002/jcb.24408] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 09/21/2012] [Indexed: 12/12/2022]
Abstract
Bone lengthening during skeletal growth is driven primarily by the controlled enlargement of growth plate (GP) chondrocytes. The cellular mechanisms are unclear but membrane transporters are probably involved. We investigated the role of the Na(+)/H(+) antiporter (NHE1) and anion exchanger (AE2) in bone lengthening and GP chondrocyte hypertrophy in Sprague-Dawley 7-day-old rat (P7) bone rudiments using the inhibitors EIPA (5-(N-ethyl-N-isopropyl)amiloride) and DIDS (4,4-diidothiocyano-2,2-stilbenedisulphonate), respectively. We have also determined cell-associated levels of these transporters along the GP using fluorescent immunohistochemistry (FIHC). Culture of bones with EIPA or DIDS inhibited rudiment growth (50% at approx. 250 and 25 µM, respectively). Both decreased the size of the hypertrophic zone (P < 0.05) but had no effect on overall length or cell density of the GP. In situ chondrocyte volume in proliferative and hypertrophic zones was decreased (P < 0.01) with EIPA but not DIDS. FIHC labeling of NHE1 was relatively high and constant along the GP but declined steeply in the late hypertrophic zone. In contrast, AE2 labeling was relatively low in proliferative zone cells but increased (P < 0.05) reaching a maximum in the early hypertrophic zone, before falling rapidly in the late hypertrophic zone suggesting AE2 might regulate the transition phase of chondrocytes between proliferative and hypertrophic zones. The inhibition of bone growth by EIPA may be due to a reduction to chondrocyte volume set-point. However the effect of DIDS was unclear but could result from inhibition of AE2 and blocking of the transition phase. These results demonstrate that NHE1 and AE2 are important regulators of bone growth.
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Affiliation(s)
- Mohamad Y Loqman
- Centre for Integrative Physiology, School of Biomedical Sciences, George Square, University of Edinburgh, Edinburgh EH8 9XD, Scotland, UK
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Vascular remodeling in pulmonary hypertension. J Mol Med (Berl) 2013; 91:297-309. [PMID: 23334338 DOI: 10.1007/s00109-013-0998-0] [Citation(s) in RCA: 168] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/04/2013] [Accepted: 01/08/2013] [Indexed: 02/07/2023]
Abstract
Pulmonary hypertension is a complex, progressive condition arising from a variety of genetic and pathogenic causes. Patients present with a spectrum of histologic and pathophysiological features, likely reflecting the diversity in underlying pathogenesis. It is widely recognized that structural alterations in the vascular wall contribute to all forms of pulmonary hypertension. Features characteristic of the remodeled vasculature in patients with pulmonary hypertension include increased stiffening of the elastic proximal pulmonary arteries, thickening of the intimal and/or medial layer of muscular arteries, development of vaso-occlusive lesions, and the appearance of cells expressing smooth muscle-specific markers in normally non-muscular small diameter vessels, resulting from proliferation and migration of pulmonary arterial smooth muscle cells and cellular transdifferentiation. The development of several animal models of pulmonary hypertension has provided the means to explore the mechanistic underpinnings of pulmonary vascular remodeling, although none of the experimental models currently used entirely replicates the pulmonary arterial hypertension observed in patients. Herein, we provide an overview of the histological abnormalities observed in humans with pulmonary hypertension and in preclinical models and discuss insights gained regarding several key signaling pathways contributing to the remodeling process. In particular, we will focus on the roles of ion homeostasis, endothelin-1, serotonin, bone morphogenetic proteins, Rho kinase, and hypoxia-inducible factor 1 in pulmonary arterial smooth muscle and endothelial cells, highlighting areas of cross-talk between these pathways and potentials for therapeutic targeting.
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Acid-base transporters modulate cell migration, growth and proliferation: Implications for structure development and remodeling of resistance arteries? Trends Cardiovasc Med 2012; 23:59-65. [PMID: 23266155 DOI: 10.1016/j.tcm.2012.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 08/29/2012] [Accepted: 08/30/2012] [Indexed: 12/20/2022]
Abstract
Disturbed acid-base transport across the plasma membrane affects intracellular pH control and has been shown--primarily based on studies with non-vascular cells--to interfere with a number of fundamental cell functions including cell migration, growth and proliferation. Here, we evaluate the effects of acid-base transport and intracellular pH on the morphology of the resistance artery wall, which is altered in a number of physiological and pathological conditions and is an independent predictor of cardiovascular risk. The current evidence supports that disturbed function and/or expression of acid-base transporters can alter resistance artery morphology--and potentially atherosclerosis-prone conduit arteries--and hence should be considered as possible mechanistic components and targets for treatment in cardiovascular disease. More experimental evidence is required, however, to evaluate the cell biological effects of acid-base transport in vascular cells, the roles of specific acid-base transporters in artery remodeling, the relative mechanistic importance of acid-base transporters in the vascular wall compared to other organs, and the therapeutic potential of modifying acid-base transport activity pharmacologically or genetically.
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Boedtkjer E, Aalkjaer C. Intracellular pH in the resistance vasculature: regulation and functional implications. J Vasc Res 2012; 49:479-96. [PMID: 22907294 DOI: 10.1159/000341235] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 06/20/2012] [Indexed: 12/18/2022] Open
Abstract
Net acid extrusion from vascular smooth muscle (VSMCs) and endothelial cells (ECs) in the wall of resistance arteries is mediated by the Na(+),HCO(3)(-) cotransporter NBCn1 (SLC4A7) and the Na(+)/H(+) exchanger NHE1 (SLC9A1) and is essential for intracellular pH (pH(i)) control. Experimental evidence suggests that the pH(i) of VSMCs and ECs modulates both vasocontractile and vasodilatory functions in resistance arteries with implications for blood pressure regulation. The connection between disturbed pH(i) and altered cardiovascular function has been substantiated by a genome-wide association study showing a link between NBCn1 and human hypertension. On this basis, we here review the current evidence regarding (a) molecular mechanisms involved in pH(i) control in VSMCs and ECs of resistance arteries at rest and during contractions, (b) implications of disturbed pH(i) for resistance artery function, and (c) involvement of disturbed pH(i) in the pathogenesis of vascular disease. The current evidence clearly implies that pH(i) of VSMCs and ECs modulates vascular function and suggests that disturbed pH(i) either consequent to disturbed regulation or due to metabolic challenges needs to be taken into consideration as a mechanistic component of artery dysfunction and disturbed blood pressure regulation.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine and Water and Salt Research Center, Aarhus University, Aarhus, Denmark.
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Zhang L, Ma J, Shen T, Wang S, Ma C, Liu Y, Ran Y, Wang L, Liu L, Zhu D. Platelet-derived growth factor (PDGF) induces pulmonary vascular remodeling through 15-LO/15-HETE pathway under hypoxic condition. Cell Signal 2012; 24:1931-9. [PMID: 22735810 DOI: 10.1016/j.cellsig.2012.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 06/16/2012] [Accepted: 06/16/2012] [Indexed: 11/30/2022]
Abstract
15-lipoxygenase (15-LO) is known to play an important role in chronic pulmonary hypertension. Accumulating evidence for its down-stream participants in the vasoconstriction and remodeling processes of pulmonary arteries, while how hypoxia regulates 15-LO/15-hydroxyeicosatetraenoic acid (15-HETE) to mediate hypoxic pulmonary hypertension is still unknown. Platelet-derived growth factor (PDGF) is an important vascular regulator whose concentration increases under hypoxic condition in the lungs of both humans and mice with pulmonary hypertension. The present study was carried out to determine whether hypoxia advances the pulmonary vascular remodeling through the PDGF/15-LO/15-HETE pathway. We found that pulmonary arterial medial thickening caused by hypoxia was alleviated after a treatment of the hypoxic rats with imatinib, which was associated with down-regulations of 15-LO-2 expression and 15-HETE production. Moreover, the increases in cell proliferation and endogenous 15-HETE content by hypoxia were attenuated by the inhibitors of PDGF-β receptor in pulmonary artery smooth muscle cells (PASMCs). The effects of PDGF-BB on cell proliferation and survival were weakened after the administration of 15-LO inhibitors or 15-LO RNA interference. These results suggest that hypoxia promotes PASMCs proliferation and survival, contributing to pulmonary vascular medial hypertrophy, which is likely to be mediated via the PDGF-BB/15-LO-2/15-HETE pathway.
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Affiliation(s)
- Lei Zhang
- Department of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, Daqing, China
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Aljubran SA, Cox R, Tamarapu Parthasarathy P, Kollongod Ramanathan G, Rajanbabu V, Bao H, Mohapatra SM, Lockey R, Kolliputi N. Enhancer of zeste homolog 2 induces pulmonary artery smooth muscle cell proliferation. PLoS One 2012; 7:e37712. [PMID: 22662197 PMCID: PMC3360676 DOI: 10.1371/journal.pone.0037712] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2011] [Accepted: 04/26/2012] [Indexed: 12/24/2022] Open
Abstract
Introduction Pulmonary Arterial Hypertension (PAH) is a progressively devastating disease characterized by excessive proliferation of the Pulmonary Arterial Smooth Muscle Cells (PASMCs). Studies suggest that PAH and cancers share an apoptosis-resistant state featuring excessive cell proliferation. The proliferation of cancer cells is mediated by increased expression of Enhancer of Zeste Homolog 2 (EZH2), a mammalian histone methyltransferase that contributes to the epigenetic silencing of target genes. However, the role of EZH2 in PAH has not been studied. In this study, it is hypothesized that EZH2 could play a role in the proliferation of PASMCs. Methods In the present study, the expression patterns of EZH2 were investigated in normal and hypertensive mouse PASMCs. The effects of EZH2 overexpression on the proliferation of human PASMCs were tested. PASMCs were transfected with EZH2 or GFP using nucleofector system. After transfection, the cells were incubated for 48 hours at 37°C. Proliferation and cell cycle analysis were performed using flow cytometry. Apoptosis of PASMCs was determined using annexin V staining and cell migration was tested by wound healing assay. Results EZH2 protein expression in mouse PASMCs were correlated with an increase in right ventricular systolic pressure and Right Ventricular Hypertrophy (RVH). The overexpression of EZH2 in human PASMCs enhances proliferation, migration, and decrease in the rate of apoptosis when compared to GFP-transfected cells. In the G2/M phase of the EZH2 transfected cells, there was a 3.5 fold increase in proliferation, while there was a significant decrease in the rate of apoptosis of PASMCs, when compared to control. Conclusion These findings suggest that EZH2 plays a role in the migration and proliferation of PASMCs, which is a major hallmark in PAH. It also suggests that EZH2 could play a role in the development of PAH and can serve as a potential target for new therapies for PAH.
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Affiliation(s)
- Salman A. Aljubran
- Division of Allergy and Immunology, Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Ruan Cox
- Division of Allergy and Immunology, Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Prasanna Tamarapu Parthasarathy
- Division of Allergy and Immunology, Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Gurukumar Kollongod Ramanathan
- Division of Allergy and Immunology, Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Venugopal Rajanbabu
- Division of Allergy and Immunology, Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Huynh Bao
- Division of Allergy and Immunology, Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Shyam M. Mohapatra
- Nanomedicine Research Center and Division of Translational Medicine, Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Richard Lockey
- Division of Allergy and Immunology, Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
| | - Narasaiah Kolliputi
- Division of Allergy and Immunology, Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
- * E-mail:
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Abstract
As can be seen by the mounting literature, there has been immense progress in the field of pulmonary hypertension (PH) over the last three decades, illustrated by several important milestones including improved understanding of disease pathogenesis, new classifications of disease, advances in screening and diagnostic techniques, and new rules for staging and follow-up, which have subsequently led to improvements in patient outcomes. The objectives of this manuscript are to not only highlight these very recent advances but also point out areas of deficiencies or gaps in our knowledge that may serve a focal point for future discussion and investigation.
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Affiliation(s)
- Irene M Lang
- Division of Cardiology, Department of Internal Medicine II, Vienna General Hospital, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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Yi B, Cui J, Ning J, Gu J, Wang G, Bai L, Qian G, Lu K. cGMP-dependent protein kinase Iα transfection inhibits hypoxia-induced migration, phenotype modulation and annexins A1 expression in human pulmonary artery smooth muscle cells. Biochem Biophys Res Commun 2012; 418:598-602. [PMID: 22293199 DOI: 10.1016/j.bbrc.2012.01.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 01/08/2012] [Indexed: 01/06/2023]
Abstract
Our previous work has demonstrated that the cellular phenotype changes of human pulmonary artery smooth muscle cells (PASMCs) play an important role during pulmonary vascular remodelling. However, little is known about the role of PASMCs phenotype modulation in the course of hypoxia-induced migration and its behind molecular mechanisms. In this study, we have shown that cGMP-dependent protein kinase (PKG) Iα transfection significantly attenuated the hypoxia-induced down-regulation of the expressions of SM-α-actin, MHC and calponin. Hypoxia-induced PASMC migration was also suppressed by PKGIα overexpression. Furthermore, this overexpression attenuated ANX A1 upregulation under hypoxic conditions. All those effects were reversed by a PKG inhibitor KT5823. Our data indicate that manipulating upstream entity e.g., PKGIa, may have a potential therapeutic value to prevent hypoxia-associated pulmonary arterial remodeling for pulmonary hypertension development.
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Affiliation(s)
- Bin Yi
- Department of Anesthesia, Southwest Hospital, The Third Military Medical University, Chongqing 400038, China
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Boedtkjer E, Damkier HH, Aalkjaer C. NHE1 knockout reduces blood pressure and arterial media/lumen ratio with no effect on resting pH(i) in the vascular wall. J Physiol 2012; 590:1895-906. [PMID: 22351634 DOI: 10.1113/jphysiol.2011.227132] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Acid–base transport in the vascular wall remains incompletely understood. Here, we investigated (a) implications of Na(+)/H(+) exchanger NHE1 knockout for vascular smooth muscle (VSMC) and endothelial cell (EC) pH(i) regulation, mesenteric artery morphology, vasomotor function and blood pressure regulation, and (b) consequences of sustained EC and VSMC acidification for vasomotor function. Na(+)/H(+) exchange activity was abolished in VSMCs and ECs from NHE1 knockout mice, but with CO(2)/HCO(3)(−) present, steady-state pH(i) was unaffected. Active tension was 30% smaller in arteries from NHE1 knockout than wild-type mice, and media thickness equally reduced. Number of VSMCs per unit artery length was unchanged whereas volume and cross-sectional area of individual VSMCs were reduced. Media stress, force production per VSMC cross-sectional area and VSMC Ca(2+) responses were unaffected. Blood pressure was 25 mmHg lower in NHE1 knockout than wild-type mice. Omission of CO(2)/HCO(3)(−) caused VSMCs and ECs to acidify substantially more in NHE1 knockout (0.3–0.6 pH-units) than wild-type (0.02–0.1 pH units) mice. Removing CO(2)/HCO(3)(−) inhibited acetylcholine-induced NO-mediated relaxations in arteries from NHE1 knockout but not wild-type mice. Without CO(2)/HCO(3)(−), effects of NO synthase and rho kinase inhibition on noradrenaline-induced contractions were smaller in arteries from NHE1 knockout than wild-type mice whereas the EC Ca(2+) response to acetylcholine, VSMC Ca(2+) response to noradrenaline and vasorelaxation to S-nitroso-N-acetylpenicillamine were unaffected. In conclusion, NHE1 mediates the Na(+)/H(+) exchange in ECs and VSMCs. Under physiological conditions, CO(2)/HCO(3)(−)-dependent mechanisms mask the pH(i)-regulatory function of NHE1. NHE1 knockout causes hypotrophy of VSMCs, reduced artery tension and lower blood pressure. At acidic pH(i), NO-mediated vasorelaxation and rho kinase-dependent VSMC Ca(2+) sensitivity are reduced.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine and the Water and Salt Research Center, Aarhus University, Aarhus C, Denmark.
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