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Targeting erythrocyte-mediated hypoxia to alleviate lung injury induced by pyrrolizidine alkaloids. Arch Toxicol 2023; 97:819-829. [PMID: 36639515 DOI: 10.1007/s00204-023-03443-1] [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: 11/29/2022] [Accepted: 01/09/2023] [Indexed: 01/15/2023]
Abstract
Pyrrolizidine alkaloids (PAs) are widely distributed natural toxins and have been extensively studied for their hepatotoxicity. However, PA-induced pulmonary toxicity remains less studied regarding the initiating mechanism and treatment approaches. Our previous study demonstrated the formation of pyrrole-hemoglobin adducts after PA exposure in vivo, which is suspected to affect the oxygen-carrying capacity of erythrocytes [red blood cells (RBCs)] consequently. The present study aimed to investigate the effects of PAs on the oxygen-carrying capacity of RBCs and the potential of targeting RBC-mediated hypoxia to alleviate PA-induced lung injury. First, rats were treated with retrorsine (RTS) or monocrotaline (MCT) intravenously at 0.2 mmol/kg. The results of Raman spectrometry analysis on blood samples revealed both RTS and MCT significantly reduced the oxygen-carrying capacity of RBCs. Further, MCT (0.2 mmol/kg) was orally given to the rats with or without pretreatment with two doses of erythropoietin (Epo, 500 IU/kg/dose every other day), an RBC-stimulating agent. Biochemical and histological results showed pretreatment with Epo effectively reduced the cardiopulmonary toxicity induced by MCT. These findings provide the first evidence that adduction on hemoglobin, and the resulting RBC damage and impaired oxygen-carrying capacity, are the major initiating mechanism underlying PA-induced pulmonary arterial hypertension (PAH), while targeting the RBC damage is a potential therapeutic approach for PA-induced lung injury.
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Gao AR, Li S, Tan XC, Huang T, Dong HJ, Xue R, Li JC, Zhang Y, Zhang YZ, Wang X. Xinyang Tablet attenuates chronic hypoxia-induced right ventricular remodeling via inhibiting cardiomyocytes apoptosis. Chin Med 2022; 17:134. [PMID: 36471367 PMCID: PMC9720925 DOI: 10.1186/s13020-022-00689-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 11/14/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Hypoxia-induced pulmonary hypertension (HPH) is one of the fatal pathologies developed under hypobaric hypoxia and eventually leads to right ventricular (RV) remodeling and RV failure. Clinically, the mortality rate of RV failure caused by HPH is high and lacks effective drugs. Xinyang Tablet (XYT), a traditional Chinese medicine exhibits significant efficacy in the treatment of congestive heart failure and cardiac dysfunction. However, the effects of XYT on chronic hypoxia-induced RV failure are not clear. METHODS The content of XYT was analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS). Sprague-Dawley (SD) rats were housed in a hypobaric chamber (equal to the parameter in altitude 5500 m) for 21 days to obtain the RV remodeling model. Electrocardiogram (ECG) and hemodynamic parameters were measured by iWorx Acquisition & Analysis System. Pathological morphological changes in the RV and pulmonary vessels were observed by H&E staining and Masson's trichrome staining. Myocardial apoptosis was tested by TUNEL assay. Protein expression levels of TNF-α, IL-6, Bax, Bcl-2, and caspase-3 in the RV and H9c2 cells were detected by western blot. Meanwhile, H9c2 cells were induced by CoCl2 to establish a hypoxia injury model to verify the protective effect and mechanisms of XYT. A CCK-8 assay was performed to determine the viability of H9c2 cells. CoCl2-induced apoptosis was detected by Annexin-FITC/PI flow cytometry and Hoechst 33,258 staining. RESULTS XYT remarkably improved RV hemodynamic disorder and ECG parameters. XYT attenuated hypoxia-induced pathological injury in RV and pulmonary vessels. We also observed that XYT treatment decreased the expression levels of TNF-α, IL-6, Bax/Bcl-2 ratio, and the numbers of myocardial apoptosis in RV. In H9c2 myocardial hypoxia model, XYT protected H9c2 cells against Cobalt chloride (CoCl2)-induced apoptosis. We also found that XYT could antagonize CoCl2-induced apoptosis through upregulating Bcl-2, inhibiting Bax and caspase-3 expression. CONCLUSIONS We concluded that XYT improved hypoxia-induced RV remodeling and protected against cardiac injury by inhibiting apoptosis pathway in vivo and vitro models, which may be a promising therapeutic strategy for clinical management of hypoxia-induced cardiac injury.
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Affiliation(s)
- An-Ran Gao
- grid.411866.c0000 0000 8848 7685Laboratory Animal Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405 China ,grid.410740.60000 0004 1803 4911State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Shuo Li
- grid.410740.60000 0004 1803 4911State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Xiao-Cui Tan
- grid.411866.c0000 0000 8848 7685Laboratory Animal Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405 China ,grid.410740.60000 0004 1803 4911State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Ting Huang
- grid.411866.c0000 0000 8848 7685Laboratory Animal Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405 China ,grid.410740.60000 0004 1803 4911State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Hua-Jin Dong
- grid.410740.60000 0004 1803 4911State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Rui Xue
- grid.410740.60000 0004 1803 4911State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Jing-Cao Li
- grid.410740.60000 0004 1803 4911State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Yang Zhang
- grid.410740.60000 0004 1803 4911State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - You-Zhi Zhang
- grid.410740.60000 0004 1803 4911State Key Laboratory of Toxicology and Medical Countermeasures, Beijing Key Laboratory of Neuropsychopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, People’s Republic of China
| | - Xiao Wang
- grid.411866.c0000 0000 8848 7685Laboratory Animal Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405 China
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COVID-19, the Pandemic of the Century and Its Impact on Cardiovascular Diseases. CARDIOLOGY DISCOVERY 2021; 1:233-258. [PMID: 34888547 PMCID: PMC8638821 DOI: 10.1097/cd9.0000000000000038] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 09/19/2021] [Indexed: 01/08/2023]
Abstract
COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection likely ranks among the deadliest diseases in human history. As with other coronaviruses, SARS-CoV-2 infection damages not only the lungs but also the heart and many other organs that express angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2. COVID-19 has upended lives worldwide. Dietary behaviors have been altered such that they favor metabolic and cardiovascular complications, while patients have avoided hospital visits because of limited resources and the fear of infection, thereby increasing out-hospital mortality due to delayed diagnosis and treatment. Clinical observations show that sex, age, and race all influence the risk for SARS-CoV-2 infection, as do hypertension, obesity, and pre-existing cardiovascular conditions. Many hospitalized COVID-19 patients suffer cardiac injury, acute coronary syndromes, or cardiac arrhythmia. SARS-CoV-2 infection may lead to cardiomyocyte apoptosis and necrosis, endothelial cell damage and dysfunction, oxidative stress and reactive oxygen species production, vasoconstriction, fibrotic and thrombotic protein expression, vascular permeability and microvascular dysfunction, heart inflammatory cell accumulation and activation, and a cytokine storm. Current data indicate that COVID-19 patients with cardiovascular diseases should not discontinue many existing cardiovascular therapies such as ACE inhibitors, angiotensin receptor blockers, steroids, aspirin, statins, and PCSK9 inhibitors. This review aims to furnish a framework relating to COVID-19 and cardiovascular pathophysiology.
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West CM, Wearing OH, Rhem RG, Scott GR. Pulmonary hypertension is attenuated and ventilation-perfusion matching is maintained during chronic hypoxia in deer mice native to high altitude. Am J Physiol Regul Integr Comp Physiol 2021; 320:R800-R811. [PMID: 33826424 DOI: 10.1152/ajpregu.00282.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hypoxia at high altitude can constrain metabolism and performance and can elicit physiological adjustments that are deleterious to health and fitness. Hypoxic pulmonary hypertension is a particularly serious and maladaptive response to chronic hypoxia, which results from vasoconstriction and pathological remodeling of pulmonary arteries, and can lead to pulmonary edema and right ventricle hypertrophy. We investigated whether deer mice (Peromyscus maniculatus) native to high altitude have attenuated this maladaptive response to chronic hypoxia and whether evolved changes or hypoxia-induced plasticity in pulmonary vasculature might impact ventilation-perfusion (V-Q) matching in chronic hypoxia. Deer mouse populations from both high and low altitudes were born and raised to adulthood in captivity at sea level, and various aspects of lung function were measured before and after exposure to chronic hypoxia (12 kPa O2, simulating the O2 pressure at 4,300 m) for 6-8 wk. In lowlanders, chronic hypoxia increased right ventricle systolic pressure (RVSP) from 14 to 19 mmHg (P = 0.001), in association with thickening of smooth muscle in pulmonary arteries and right ventricle hypertrophy. Chronic hypoxia also impaired V-Q matching in lowlanders (measured at rest using SPECT-CT imaging), as reflected by increased log SD of the perfusion distribution (log SDQ) from 0.55 to 0.86 (P = 0.031). In highlanders, chronic hypoxia had attenuated effects on RVSP and no effects on smooth muscle thickness, right ventricle mass, or V-Q matching. Therefore, evolved changes in lung function help attenuate maladaptive plasticity and contribute to hypoxia tolerance in high-altitude deer mice.
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Affiliation(s)
- Claire M West
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Oliver H Wearing
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Rod G Rhem
- Division of Respirology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Graham R Scott
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
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Luo J, Zhu X, Jian J, Chen XU, Yin K. Cardiovascular disease in patients with COVID-19: evidence from cardiovascular pathology to treatment. Acta Biochim Biophys Sin (Shanghai) 2021; 53:273-282. [PMID: 33428706 PMCID: PMC7929476 DOI: 10.1093/abbs/gmaa176] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Indexed: 01/08/2023] Open
Abstract
The coronavirus disease-2019 (COVID-19) caused by the novel coronavirus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has rapidly developed into a global pneumonia pandemic. Cardiovascular disease is the major comorbidity of COVID-19 patients and is closely related to the severity of COVID-19. SARS-CoV-2 infection can directly or indirectly cause a series of cardiac complications, including acute myocardial injury and myocarditis, heart failure and cardiac arrest, arrhythmia, acute myocardial infarction, cardiogenic shock, Takotsubo cardiomyopathy, and coagulation abnormalities. Intensive research on the SARS-CoV-2-associated cardiovascular complications is urgently needed to elucidate its exact mechanism and to identify potential drug targets, which will help to formulate effective prevention and treatment strategies. Hence, this review will summarize recent progress regarding the effects of COVID-19 on the cardiovascular system and describe the underlying mechanism of cardiovascular injury caused by SARS-CoV-2.
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Affiliation(s)
| | | | - Jie Jian
- College of Pharmacy, Guilin Medical University, Guilin 541004, China
| | - X u Chen
- *Correspondence address. Tel: +86-13907736890; E-mail: (X.C.) / Tel: +86-773-5369253; E-mail: (K.Y.)
| | - Kai Yin
- *Correspondence address. Tel: +86-13907736890; E-mail: (X.C.) / Tel: +86-773-5369253; E-mail: (K.Y.)
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Humphries CP. Lower Respiratory Tract Infection: An Unrecognised Risk Factor for High Altitude Pulmonary Oedema? Eur J Case Rep Intern Med 2017; 4:000539. [PMID: 30755928 PMCID: PMC6346869 DOI: 10.12890/2017_000539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 12/16/2016] [Indexed: 12/02/2022] Open
Abstract
The case of a 25-year-old expedition doctor who developed high altitude pulmonary oedema (HAPE) while climbing in the Swiss Alps is presented, with reference to the literature. The patient’s symptoms of HAPE were typical. Less typical was the fact that the doctor had previously been to similar altitudes uneventfully. The only differentiator is that on this expedition he developed a mild lower respiratory tract infection (LRTI) 2 days prior to travel. There has been limited, conflicting evidence regarding LRTI as a risk factor for HAPE and high quality research has not focused on this area. LRTI is not commonly recognised as being a risk in high altitude environments, which may be resulting in lethal consequences. This report aims to inform, provide a clinical question for future high altitude research expeditions, and encourage consideration by expedition and high altitude doctors.
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Hussain A, Suleiman MS, George SJ, Loubani M, Morice A. Hypoxic Pulmonary Vasoconstriction in Humans: Tale or Myth. Open Cardiovasc Med J 2017; 11:1-13. [PMID: 28217180 PMCID: PMC5301302 DOI: 10.2174/1874192401711010001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 12/02/2016] [Accepted: 12/09/2016] [Indexed: 12/13/2022] Open
Abstract
Hypoxic Pulmonary vasoconstriction (HPV) describes the physiological adaptive process of lungs to preserves systemic oxygenation. It has clinical implications in the development of pulmonary hypertension which impacts on outcomes of patients undergoing cardiothoracic surgery. This review examines both acute and chronic hypoxic vasoconstriction focusing on the distinct clinical implications and highlights the role of calcium and mitochondria in acute versus the role of reactive oxygen species and Rho GTPases in chronic HPV. Furthermore it identifies gaps of knowledge and need for further research in humans to clearly define this phenomenon and the underlying mechanism.
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Affiliation(s)
- A Hussain
- Department of Cardiothoracic Surgery, Castle Hill Hospital, Castle Road, Cottingham, HU16 5JQ, UK
| | - M S Suleiman
- School of Clinical Sciences, Bristol Royal Infirmary, Marlborough Street, Bristol, BS2 8HW, UK
| | - S J George
- School of Clinical Sciences, Bristol Royal Infirmary, Marlborough Street, Bristol, BS2 8HW, UK
| | - M Loubani
- Department of Cardiothoracic Surgery, Castle Hill Hospital, Castle Road, Cottingham, HU16 5JQ, UK
| | - A Morice
- Department of Respiratory Medicine, Castle Hill Hospital, Castle Road, Cottingham, HU16 5JQ, UK
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8
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Soree P, Gupta RK, Singh K, Desiraju K, Agrawal A, Vats P, Bharadwaj A, Baburaj TP, Chaudhary P, Singh VK, Verma S, Bajaj AC, Singh SB. Raised HIF1α during normoxia in high altitude pulmonary edema susceptible non-mountaineers. Sci Rep 2016; 6:26468. [PMID: 27210110 PMCID: PMC4876441 DOI: 10.1038/srep26468] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/29/2016] [Indexed: 12/29/2022] Open
Abstract
High altitude pulmonary edema (HAPE) susceptibility is associated with EGLN1 polymorphisms, we hypothesized that HAPE-susceptible (HAPE-S, had HAPE episode in past) subjects may exhibit abnormal HIF1α levels in normoxic conditions. We measured HIF1α levels in HAPE-S and HAPE resistant (HAPE-R, no HAPE episode) individuals with similar pulmonary functions. Hemodynamic responses were also measured before and after normobaric hypoxia (Fi02 = 0.12 for 30 min duration at sea level) in both groups. . HIF1α was higher in HAPE-S (320.3 ± 267.5 vs 58.75 ± 33.88 pg/ml, P < 0.05) than HAPE-R, at baseline, despite no significant difference in baseline oxygen saturations (97.7 ± 1.7% and 98.8 ± 0.7). As expected, HAPE-S showed an exaggerated increase in pulmonary artery pressure (27.9 ± 6 vs 19.3 ± 3.7 mm Hg, P < 0.05) and a fall in peripheral oxygen saturation (66.9 ± 11.7 vs 78.7 ± 3.8%, P < 0.05), when exposed to hypoxia. HIF1α levels at baseline could accurately classify members of the two groups (AUC = 0.87). In a subset of the groups where hemoglobin fractions were additionally measured to understand the cause of elevated hypoxic response at baseline, two of four HAPE-S subjects showed reduced HbA. In conclusion, HIF 1 α levels during normoxia may represent an important marker for determination of HAPE susceptibility.
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Affiliation(s)
- Poonam Soree
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - Rajinder K. Gupta
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - Krishan Singh
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - Koundinya Desiraju
- CSIR Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India
| | - Anurag Agrawal
- CSIR Institute of Genomics and Integrative Biology, Mall Road, Delhi 110007, India
| | - Praveen Vats
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - Abhishek Bharadwaj
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - T. P. Baburaj
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - Pooja Chaudhary
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - Vijay K. Singh
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - Saroj Verma
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - Amir Chand Bajaj
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
| | - Shashi Bala Singh
- Defence Institute of Physiology and Allied Sciences, Timarpur, Delhi 110054, India
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9
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Mohsenin V. The emerging role of microRNAs in hypoxia-induced pulmonary hypertension. Sleep Breath 2016; 20:1059-67. [DOI: 10.1007/s11325-016-1351-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Revised: 04/11/2016] [Accepted: 04/19/2016] [Indexed: 11/30/2022]
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10
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Kholdani C, Fares WH, Mohsenin V. Pulmonary hypertension in obstructive sleep apnea: is it clinically significant? A critical analysis of the association and pathophysiology. Pulm Circ 2015; 5:220-7. [PMID: 26064448 DOI: 10.1086/679995] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 09/02/2014] [Indexed: 12/15/2022] Open
Abstract
The development of pulmonary hypertension is a poor prognostic sign in patients with obstructive sleep apnea (OSA) and affects both mortality and quality of life. Although pulmonary hypertension in OSA is traditionally viewed as a result of apneas and intermittent hypoxia during sleep, recent studies indicate that neither of these factors correlates very well with pulmonary artery pressure. Human data show that pulmonary hypertension in the setting of OSA is, in large part, due to left heart dysfunction with either preserved or diminished ejection fraction. Longstanding increased left heart filling pressures eventually lead to pulmonary venous hypertension. The combination of hypoxic pulmonary vasoconstriction and pulmonary venous hypertension with abnormal production of mediators will result in vascular cell proliferation and aberrant vascular remodeling leading to pulmonary hypertension. These changes are in many ways similar to those seen in other forms of pulmonary hypertension and suggest shared mechanisms. The majority of patients with OSA do not receive a diagnosis and are undertreated. Appreciating the high prevalence and understanding the mechanisms of pulmonary hypertension in OSA would lead to better recognition and management of the condition.
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Affiliation(s)
- Cyrus Kholdani
- Section of Pulmonary, Critical Care and Sleep Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Wassim H Fares
- Section of Pulmonary, Critical Care and Sleep Medicine, Yale School of Medicine, New Haven, Connecticut, USA
| | - Vahid Mohsenin
- Section of Pulmonary, Critical Care and Sleep Medicine, Yale School of Medicine, New Haven, Connecticut, USA
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11
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Wang W, Liu J, Ma A, Miao R, Jin Y, Zhang H, Xu K, Wang C, Wang J. mTORC1 Is Involved in Hypoxia-Induced Pulmonary Hypertension Through the Activation of Notch3. J Cell Physiol 2014; 229:2117-25. [PMID: 24825564 DOI: 10.1002/jcp.24670] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 05/09/2014] [Indexed: 11/06/2022]
Affiliation(s)
- Wang Wang
- Department of Physiology; Capital Medical University; Beijing P.R. China
| | - Jie Liu
- Department of Physiology; Capital Medical University; Beijing P.R. China
| | - Aiping Ma
- Department of Respiratory Medicine; Peking Union Medical College Hospital; Beijing P.R. China
| | - Ran Miao
- Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders; Capital Medical University; Beijing P.R. China
| | - Yuling Jin
- Department of Physiology; Capital Medical University; Beijing P.R. China
| | - Hongbing Zhang
- Department of Physiology and Pathophysiology; State Key Laboratory of Medical Molecular Biology; Institute of Basic Medical Sciences and School of Basic Medicine; Chinese Academy of Medical Sciences and Peking Union Medical College; Beijing P.R. China
| | - Kaifeng Xu
- Department of Respiratory Medicine; Peking Union Medical College Hospital; Beijing P.R. China
| | - Chen Wang
- Beijing Key Laboratory of Respiratory and Pulmonary Circulation Disorders; Capital Medical University; Beijing P.R. China
- Beijing Hospital; Ministry of Health; Beijing P.R. China
| | - Jun Wang
- Department of Physiology; Capital Medical University; Beijing P.R. China
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12
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Wang LE, Zhou Y, Li M, Zhu Y. Expression of hypoxia-inducible factor-1α, endothelin-1 and adrenomedullin in newborn rats with hypoxia-induced pulmonary hypertension. Exp Ther Med 2014; 8:335-339. [PMID: 24944643 PMCID: PMC4061228 DOI: 10.3892/etm.2014.1728] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 05/02/2014] [Indexed: 11/22/2022] Open
Abstract
Hypoxia-inducible factor (HIF)-1α is associated with hypoxia-induced pulmonary hypertension (HPH) in adults. In the present study, the expression levels of HIF-1α, endothelin (ET)-1 and adrenomedullin (ADM) were analyzed during HPH in neonates. In total, 96 newborn rats were subjected to hypoxia or normoxia for 3, 5, 7, 10, 14 or 21 days (n=8 per subgroup). HIF-1α, ET-1 and ADM expression levels were measured by quantitative polymerase chain reaction. In addition, the intima-media thickness/external diameter ratio (MT%) and medial wall cross-sectional area/vessel total cross-sectional area ratio (MA%) were calculated to evaluate pulmonary vascular remodeling. The mean pulmonary arterial pressure (mPAP) increased with exposure to hypoxia. Furthermore, the expression levels of HIF-1α, ET-1 and ADM in the lungs were shown to increase after three and five days of hypoxia, while the MT% and MA% increased after seven days of hypoxia, as compared with the controls (P<0.05). Therefore, the expression of HIF-1α, ET-1 and ADM is upregulated in the lungs of newborn rats during early HPH. At later stages, the mPAP increases, vascular remodeling occurs and HIF-1α, ET-1 and ADM expression levels restore to normal levels.
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Affiliation(s)
- LE Wang
- Department of Neonatology, The First Affiliated Hospital of Xinjiang Medical University, Ürümqi, Xinjiang 830011, P.R. China
| | - Ying Zhou
- Department of Neonatology, The First Affiliated Hospital of Xinjiang Medical University, Ürümqi, Xinjiang 830011, P.R. China
| | - Mingxia Li
- Department of Neonatology, The First Affiliated Hospital of Xinjiang Medical University, Ürümqi, Xinjiang 830011, P.R. China
| | - Yanping Zhu
- Department of Neonatology, The First Affiliated Hospital of Xinjiang Medical University, Ürümqi, Xinjiang 830011, P.R. China
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13
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Abstract
Hypoxic pulmonary vasoconstriction (HPV) continues to fascinate cardiopulmonary physiologists and clinicians since its definitive description in 1946. Hypoxic vasoconstriction exists in all vertebrate gas exchanging organs. This fundamental response of the pulmonary vasculature in air breathing animals has relevance to successful fetal transition to air breathing at birth and as a mechanism of ventilation-perfusion matching in health and disease. It is a complex process intrinsic to the vascular smooth muscle, but with in vivo modulation by a host of factors including the vascular endothelium, erythrocytes, pulmonary innervation, circulating hormones and acid-base status to name only a few. This review will provide a broad overview of HPV and its mechansms and discuss the advantages and disadvantages of HPV in normal physiology, disease and high altitude.
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Affiliation(s)
- Erik R Swenson
- Department of Medicine, University of Washington, VA Puget Sound Health Care System, Seattle, WA 98108, USA.
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14
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Schmerbach K, Patzak A. Pathophysiological mechanisms in acute mountain sickness. Acta Physiol (Oxf) 2013; 209:246-9. [PMID: 24119164 DOI: 10.1111/apha.12175] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- K. Schmerbach
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
| | - A. Patzak
- Institute of Vegetative Physiology; Charité-Universitätsmedizin Berlin; Berlin Germany
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15
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Hypoxic pulmonary vasoconstriction in humans. BIOMED RESEARCH INTERNATIONAL 2013; 2013:623684. [PMID: 24024204 PMCID: PMC3762074 DOI: 10.1155/2013/623684] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 07/04/2013] [Accepted: 07/22/2013] [Indexed: 12/17/2022]
Abstract
Hypoxic pulmonary vasoconstriction is the elegant theory put forward more than six decades ago to explain regional variations in perfusion within the lung in certain animal species in response to localised restrictions in oxygenation. Although considerable progress has been made to describe the phenomenon at the macroscopic level and explain it at the microscopic level, we are far from a universal agreement about the process in humans. This review attempts to highlight some of the important evidence bases of hypoxic pulmonary vasoconstriction in humans and the significant gaps in our knowledge that would need bridging.
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Lundgren J, Kylhammar D, Hedelin P, Rådegran G. sGC stimulation totally reverses hypoxia-induced pulmonary vasoconstriction alone and combined with dual endothelin-receptor blockade in a porcine model. Acta Physiol (Oxf) 2012; 206:178-94. [PMID: 22682645 DOI: 10.1111/j.1748-1716.2012.02445.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 12/21/2011] [Accepted: 04/12/2012] [Indexed: 11/30/2022]
Abstract
AIM Stimulation of soluble guanylate cyclase (sGC) with BAY 41-8543 was hypothesized to attenuate acute hypoxic pulmonary vasoconstriction alone and combined with dual endothelin (ET)-receptor antagonist tezosentan. METHODS Measurements were taken in 18 anaesthetized pigs with a mean ± SEM weight of 31.1 ± 0.4 kg, in normoxia (FiO(2)~0.21) and hypoxia (FiO(2)~0.10) without (control protocol, n = 6), and with right atrial infusion of BAY 41-8543 at 1, 3, 6, 9 and 12 μg min(-1) per kg (protocol 2, n = 6) or tezosentan at 5 mg kg(-1) followed by BAY 41-8543 at 1, 3 and 6 μg min(-1) per kg (protocol 3, n = 6). RESULTS Hypoxia (n = 18) increased (P < 0.001) mean pulmonary artery pressure (MPAP) and pulmonary vascular resistance (PVR) by 14.2 ± 0.6 mmHg and 2.8 ± 0.3 WU respectively. During sustained hypoxia without treatment, MPAP and PVR remained stable. BAY 41-8543 (n = 6) dose-dependently decreased (P < 0.001) MPAP and PVR by 15.0 ± 1.2 mmHg and 4.7 ± 0.7 WU respectively. Tezosentan (n = 6) decreased (P < 0.001) MPAP and PVR by 11.8 ± 1.2 mmHg and 2.0 ± 0.2 WU, respectively, whereafter BAY 41-8543 (n = 6) further decreased (P < 0.001) MPAP and PVR by 6.6 ± 0.9 mmHg and 1.9 ± 0.4 WU respectively. Both BAY 41-8543 and tezosentan decreased (P < 0.001) systemic arterial pressure and systemic vascular resistance. Blood-O(2) consumption remained unaltered (P = ns) during all interventions. CONCLUSION BAY 41-8543 totally reverses the effects of acute hypoxia-induced pulmonary vasoconstriction, and enhances the attenuating effects of tezosentan, without affecting oxygenation. Thus, sGC stimulation, alone or combined with dual ET-receptor blockade, could offer a means to treat pulmonary hypertension related to hypoxia and potentially other causes.
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Affiliation(s)
- J Lundgren
- The Öresund Cardiovascular Research Collaboration, The Clinic for Heart Failure and Valvular Disease, Skåne University Hospital, Lund, Sweden
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Hedelin P, Kylhammar D, Rådegran G. Dual endothelin receptor blockade with tezosentan markedly attenuates hypoxia-induced pulmonary vasoconstriction in a porcine model. Acta Physiol (Oxf) 2012; 204:419-34. [PMID: 21726419 DOI: 10.1111/j.1748-1716.2011.02339.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM Our aim was to test the hypothesis that dual endothelin receptor blockade with tezosentan attenuates hypoxia-induced pulmonary vasoconstriction. METHODS Fourteen anaesthetized, ventilated pigs, with a mean ± SEM weight of 30.5 ± 0.6 kg, were studied, in normoxia (FiO(2) 0.21) and with tezosentan (5 mg kg(-1)) infusion during (n = 7) or before (n = 7) hypoxia (FiO(2) 0.10). RESULTS Compared to normoxia, hypoxia increased (P < 0.05) pulmonary vascular resistance (PVR) by 3.4 ± 0.7 WU, mean pulmonary artery pressure by 13.7 ± 1.3 mmHg, mean right atrial pressure by 1.9 ± 0.4 mmHg and decreased (P < 0.02) systemic vascular resistance (SVR) by 5.2 ± 2.1 WU. Pulmonary capillary wedge pressure (PCWP), mean aortic blood pressure, heart rate, cardiac output, stroke volume and blood-O(2)-consumption were unaltered (P = ns). Tezosentan infused during hypoxia, normalized PVR, decreased (P < 0.05) maximally mean pulmonary artery pressure by 7.5 ± 0.8 mmHg, SVR by 5.8 ± 0.7 WU, mean aortic blood pressure by 10.8 ± 3.0 mmHg and increased (P < 0.04) stroke volume by 8.5 ± 1.8 mL. Mean right atrial pressure, PCWP, heart rate, cardiac output and blood-O(2) -consumption were unaltered (P = ns). Tezosentan infused before hypoxia additionally attenuated approx. 70% of the initial mean pulmonary artery pressure increase and abolished the PVR increase, without additionally affecting the other parameters. CONCLUSION Dual endothelin receptor blockade during hypoxia attenuates the 'sustained' acute pulmonary vasoconstrictor response by reducing the mean pulmonary artery pressure increase by approx. 62% and by normalizing PVR. Pre-treatment with tezosentan before hypoxia, additionally attenuates the initial hypoxia-induced mean pulmonary artery pressure rise by approx. 70% and abolishes the PVR increase, during stable circulatory conditions, without affecting oxygenation.
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Affiliation(s)
- P Hedelin
- The Öresund Cardiovascular Research Collaboration, The Clinic for Heart Failure and Valvular Disease, Skåne University Hospital, Lund, Sweden
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Amen EM, Becker EM, Truebel H. Analysis of V/Q-matching—a safety “biomarker” in pulmonary drug development? Biomarkers 2011; 16 Suppl 1:S5-10. [DOI: 10.3109/1354750x.2011.585243] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Hebbel RP. Reconstructing sickle cell disease: a data-based analysis of the "hyperhemolysis paradigm" for pulmonary hypertension from the perspective of evidence-based medicine. Am J Hematol 2011; 86:123-54. [PMID: 21264896 DOI: 10.1002/ajh.21952] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The "hyperhemolytic paradigm" (HHP) posits that hemolysis in sickle disease sequentially and causally establishes increased cell-free plasma Hb, consumption of NO, a state of NO biodeficiency, endothelial dysfunction, and a high prevalence of pulmonary hypertension. The basic science underpinning this concept has added an important facet to the complexity of vascular pathobiology in sickle disease, and clinical research has identified worrisome clinical issues. However, this critique identifies and explains a number of significant concerns about the various HHP component tenets. In addressing these issues, this report presents: a very brief history of the HHP, an integrated synthesis of mechanisms underlying sickle hemolysis, a review of the evidentiary value of hemolysis biomarkers, an examination of evidence bearing on existence of a hyperhemolytic subgroup, and a series of questions that should naturally be applied to the HHP if it is examined using critical thinking skills, the fundamental basis of evidence-based medicine. The veracity of different HHP tenets is found to vary from true, to weakly supported, to demonstrably false. The thesis is developed that the HHP has misidentified the mechanism and clinical significance of its findings. The extant research questions identified by these analyses are delineated, and a conservative, evidence-based approach is suggested for application in clinical medicine.
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Affiliation(s)
- Robert P. Hebbel
- Department of Medicine, Division of Hematology‐Oncology‐Transplantation, Vascular Biology Center, University of Minnesota Medical School, Minneapolis, Minnesota
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Krotova K, Patel JM, Block ER, Zharikov S. Hypoxic upregulation of arginase II in human lung endothelial cells. Am J Physiol Cell Physiol 2010; 299:C1541-8. [PMID: 20861464 DOI: 10.1152/ajpcell.00068.2010] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Activated arginase has been implicated in many diseases including cancer, immune cell dysfunction, infections, and vascular disease. Enhanced arginase activity has been reported in lungs of patients with pulmonary artery hypertension. We used hypoxia as a model for pulmonary hypertension and studied the effect of exposure to hypoxia on arginase activity in human lung microvascular endothelial cells (HMVEC). Hypoxia induces upregulation of arginase activity as well as mRNA and protein levels of arginase II (Arg II), the only arginase isoform we were able to identify in HMVEC. In endothelial cells, arginase shares and competes for the substrate l-arginine with nitric oxide (NO) synthase (NOS). Through regulation of substrate availability for NOS, arginase is able to modulate NO production. To evaluate the role of Arg II in regulation of NO production under hypoxia, we compared NO output (RFL-6 reporter assay) in cells with normal and silenced Arg II. Exposure to hypoxia led to an increase in NO levels produced by HMVEC. Inhibition of Arg II by specific small interfering RNA or by the pharmacological inhibitor BEC additionally enhanced the levels of NO. Another possible role for activated arginase is involvement in regulation of cell proliferation. However, we showed that hypoxia decreased cell proliferation and upregulated Arg II did not have an effect on cell proliferation. Since hypoxia-inducible factors (HIF) are a family of transcriptional factors activated by hypoxia, we tested the possibility of involvement of HIF-1 and HIF-2 in regulation of Arg II under hypoxia. The silencing of HIF-2 but not HIF-1 prevented the activation of Arg II by hypoxia.
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Affiliation(s)
- Karina Krotova
- Dept. of Medicine, MSB Rm. M452, Univ. of Florida, Gainesville, FL 32610, USA.
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Wick MJ, Buesing EJ, Wehling CA, Loomis ZL, Cool CD, Zamora MR, Miller YE, Colgan SP, Hersh LB, Voelkel NF, Dempsey EC. Decreased neprilysin and pulmonary vascular remodeling in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2010; 183:330-40. [PMID: 20813891 DOI: 10.1164/rccm.201002-0154oc] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
RATIONALE Studies with genetically engineered mice showed that decreased expression of the transmembrane peptidase neprilysin (NEP) increases susceptibility to hypoxic pulmonary vascular remodeling and hypertension; in hypoxic wild-type mice, expression is decreased early in distal pulmonary arteries, where prominent vascular remodeling occurs. Therefore, in humans with smoke- and hypoxia-induced vascular remodeling, as in chronic obstructive pulmonary disease (COPD), pulmonary activity/expression of NEP may likewise be decreased. OBJECTIVES To test whether NEP activity and expression are reduced in COPD lungs and pulmonary arterial smooth muscle cells (SMCs) exposed to cigarette smoke extract or hypoxia and begin to investigate mechanisms involved. METHODS Control and advanced COPD lung lysates (n = 13-14) were analyzed for NEP activity and protein and mRNA expression. As a control, dipeptidyl peptidase IV activity was analyzed. Lung sections were assessed for vascular remodeling and oxidant damage. Human pulmonary arterial SMCs were exposed to cigarette smoke extract, hypoxia, or H₂O₂, and incubated with antioxidants or lysosomal/proteasomal inhibitors. MEASUREMENTS AND MAIN RESULTS COPD lungs demonstrated areas of vascular rarification, distal muscularization, and variable intimal and prominent medial/adventitial thickening. NEP activity was reduced by 76%; NEP protein expression was decreased in alveolar walls and distal vessels; mRNA expression was also decreased. In SMCs exposed to cigarette smoke extract, hypoxia, and H₂O₂, NEP activity and expression were also reduced. Reactive oxygen species inactivated NEP activity; NEP protein degradation appeared to be substantially induced. CONCLUSIONS Mechanisms responsible for reduced NEP activity and protein expression include oxidative reactions and protein degradation. Maintaining or increasing lung NEP may protect against pulmonary vascular remodeling in response to chronic smoke and hypoxia.
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Affiliation(s)
- Marilee J Wick
- Cardiovascular Pulmonary Research Laboratory, University of Colorado Denver, Aurora, CO 80045, USA.
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Tabima DM, Chesler NC. The effects of vasoactivity and hypoxic pulmonary hypertension on extralobar pulmonary artery biomechanics. J Biomech 2010; 43:1864-9. [PMID: 20416876 DOI: 10.1016/j.jbiomech.2010.03.033] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 03/17/2010] [Accepted: 03/19/2010] [Indexed: 11/25/2022]
Abstract
Loss of large artery compliance is an emerging novel predictor of cardiovascular mortality. Hypoxia-induced pulmonary hypertension (HPH) has been shown to decrease extralobar pulmonary artery (PA) compliance in the absence of smooth muscle cell (SMC) tone and to increase SMC tone in peripheral PAs. We sought to determine the impact of HPH on extralobar PA tone and the impact of SMC activation on extralobar PA biomechanics. To do so, C57BL6 mice were exposed to 0 (CTL) or 10 days (HPH) of hypoxia and isolated vessel tests were performed on extralobar PAs using either a physiological saline solution (PSS), a vasoconstrictor (U46619), two vasodilators (SNP and Y27632) or calcium free medium (relaxant solution; VBRS). The vasodilators and relaxant solution had no effect on extralobar artery diameter suggesting that basal SMC tone is essentially zero in CTL conditions and does not increase with HPH. HPH caused narrowing, decreased circumferential stretch (lambda; p<0.0001), decreased local area compliance (C(A); p<0.0005) and increased incremental elastic modulus (E(inc); p<0.05) in the normal tone state (with PSS). In both CTL and HPH conditions, SMC activation decreased E(inc) (p<0.0005) but also increased wall thickness (p<0.05) such that changes in C(A) with SMC constriction were minimal; only in HPH PAs was a significant decrease with SMC constriction observed (p<0.05). Our results demonstrate that 10 days of hypoxia does not increase extralobar PA SMC tone and that HPH-induced decreases in compliance are caused by narrowing, wall thickening and increases in modulus, not persistent vasoconstriction.
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Affiliation(s)
- Diana M Tabima
- Department of Biomedical Engineering, University of Wisconsin at Madison, 2146 Engineering Centers Building, 1550 Engineering Drive, Madison, WI 53706-1609, USA
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Niu X, Nouraie M, Campbell A, Rana S, Minniti CP, Sable C, Darbari D, Dham N, Reading NS, Prchal JT, Kato GJ, Gladwin MT, Castro OL, Gordeuk VR. Angiogenic and inflammatory markers of cardiopulmonary changes in children and adolescents with sickle cell disease. PLoS One 2009; 4:e7956. [PMID: 19956689 PMCID: PMC2776981 DOI: 10.1371/journal.pone.0007956] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Accepted: 10/26/2009] [Indexed: 11/19/2022] Open
Abstract
Background Pulmonary hypertension and left ventricular diastolic dysfunction are complications of sickle cell disease. Pulmonary hypertension is associated with hemolysis and hypoxia, but other unidentified factors are likely involved in pathogenesis as well. Design and Methods Plasma concentrations of three angiogenic markers (fibroblast growth factor, platelet derived growth factor–BB [PDGF-BB], vascular endothelial growth factor [VEGF]) and seven inflammatory markers implicated in pulmonary hypertension in other settings were determined by Bio-Plex suspension array in 237 children and adolescents with sickle cell disease at steady state and 43 controls. Tricuspid regurgitation velocity (which reflects systolic pulmonary artery pressure), mitral valve E/Edti ratio (which reflects left ventricular diastolic dysfunction), and a hemolytic component derived from four markers of hemolysis and hemoglobin oxygen saturation were also determined. Results Plasma concentrations of interleukin-8, interleukin-10 and VEGF were elevated in the patients with sickle cell disease compared to controls (P≤0.003). By logistic regression, greater values for PDGF-BB (P = 0.009), interleukin-6 (P = 0.019) and the hemolytic component (P = 0.026) were independently associated with increased odds of elevated tricuspid regurgitation velocity while higher VEGF concentrations were associated with decreased odds (P = 0.005) among the patients with sickle cell disease. These findings, which are consistent with reports that PDGF-BB stimulates and VEGF inhibits vascular smooth muscle cell proliferation, did not apply to E/Etdi. Conclusions Circulating concentrations of angiogenic and pro-Inflammatory markers are altered in sickle cell disease children and adolescents with elevated tricuspid regurgitation velocity, a subgroup that may be at risk for developing worsening pulmonary hypertension. Further studies to understand the molecular changes in these children are indicated.
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Affiliation(s)
- Xiaomei Niu
- Center for Sickle Cell Disease, Howard University, Washington, D. C., United States of America
| | - Mehdi Nouraie
- Center for Sickle Cell Disease, Howard University, Washington, D. C., United States of America
| | - Andrew Campbell
- Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Sohail Rana
- Center for Sickle Cell Disease, Howard University, Washington, D. C., United States of America
| | - Caterina P. Minniti
- Pulmonary and Vascular Medicine Branch, National Heart, Lung and Blood Institute, Clinical Center, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Craig Sable
- Department of Cardiology, Children's National Medical Center, Washington, D. C., United States of America
| | - Deepika Darbari
- Department of Hematology, Children's National Medical Center, Washington, D. C., United States of America
| | - Niti Dham
- Department of Cardiology, Children's National Medical Center, Washington, D. C., United States of America
| | - N. Scott Reading
- University of Utah, ARUP Institute of Clinical and Experimental Pathology, and Veterans Administration Hospital, Salt Lake City, Utah, United States of America
| | - Josef T. Prchal
- University of Utah, ARUP Institute of Clinical and Experimental Pathology, and Veterans Administration Hospital, Salt Lake City, Utah, United States of America
| | - Gregory J. Kato
- Pulmonary and Vascular Medicine Branch, National Heart, Lung and Blood Institute, Clinical Center, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Mark T. Gladwin
- Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh Medical Center and Hemostasis and Vascular Biology Research Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Oswaldo L. Castro
- Center for Sickle Cell Disease, Howard University, Washington, D. C., United States of America
| | - Victor R. Gordeuk
- Center for Sickle Cell Disease, Howard University, Washington, D. C., United States of America
- * E-mail:
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A randomized double-blind placebo-controlled study of the long-term efficacy and safety of diethylpropion in the treatment of obese subjects. Int J Obes (Lond) 2009; 33:857-65. [PMID: 19564877 DOI: 10.1038/ijo.2009.124] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To evaluate the efficacy of diethylpropion on a long-term basis, with emphasis in cardiovascular and psychiatric safety aspects. DESIGN Randomized, double-blind, placebo-controlled trial. MEASUREMENTS Following a 2-week screening period, 69 obese healthy adults received a hypocaloric diet and were randomized to diethylpropion 50 mg BID (n=37) or placebo (n=32) for 6 months. After this period, all participants received diethylpropion in an open-label extension for an additional 6 months. The primary outcome was percentage change in body weight. Electrocardiogram (ECG), echocardiography and clinical chemistry were performed at baseline and every 6 months. Psychiatric evaluation and application of Hamilton rating scales for depression and anxiety were also performed by experienced psychiatrists at baseline and every 3 months. RESULTS After 6 months, the diethylpropion group lost an average of 9.8% (s.d. 6.9%) of initial body weight vs 3.2% (3.7%) in the placebo group (P<0.0001). From baseline to month 12, the mean weight loss produced by diethylpropion was 10.6% (8.3%). Participants in the placebo group who were switched to diethylpropion after 6 months lost an average of 7.0% (7.7%) of initial body weight. The difference between groups at month 12 was not significant (P=0.07). No differences in blood pressure, pulse rate, ECG and psychiatric evaluation were observed. Dry mouth and insomnia were the most frequent adverse events. CONCLUSION Diethylpropion plus diet produced sustained and clinically significant weight loss over 1 year. It seems to be safe in relation to cardiovascular and psychiatric aspects in a well-selected population.
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Yu J, Feng HS, Chen BY, Qu P, Liu LB, Chen JK, Tie R, Huang XJ, Zhao YF, Zhu XX, Zhu MZ. Protective effects of vasonatrin peptide against hypobaric hypoxia-induced pulmonary hypertension in rats. Clin Exp Pharmacol Physiol 2009; 37:69-74. [PMID: 19566831 DOI: 10.1111/j.1440-1681.2009.05240.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
1. The aim of the present study was to investigate the in vivo effects of vasonatrin peptide (VNP) on hypoxia-induced pulmonary hypertension (HPH). 2. The HPH model was developed by subjecting rats to hypobaric hypoxia. The HPH rats were then treated with either VNP (50 microg/kg per day, i.p.) or saline (0.5 mL, i.p.) every day for 7 days. Haemodynamic indices, right ventricular hypertrophy (RVH) and remodelling of the pulmonary arteries were evaluated. In addition, plasma levels of atrial natriuretic peptide (ANP), endothelin (ET)-1 and angiotensin II (AngII) were determined, as was natriuretic peptide receptor-C (NPR-C) mRNA expression in the right ventricle. 3. Hypobaric hypoxia induced severe HPH compared with the normoxic control group. Treatment of HPH rats with VNP for 1 week significantly reduced mean pulmonary arterial pressure, pulmonary vascular resistance, RVH and muscularization of the pulmonary arteries, although pulmonary blood flow was increased in this group. In addition, significantly lower levels of plasma ET-1 and AngII and cardiac NPR-C mRNA expression were observed in VNP-treated compared with saline-treated HPH rats, whereas higher plasma concentrations of ANP were found in the former group. Acute intravenous administration of 50 microg/kg VNP significantly ameliorated pulmonary haemodynamics in HPH rats. 4. Taken together, the date indicate that VNP has certain preventative and therapeutic effects against HPH.
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Affiliation(s)
- Jun Yu
- Center of Teaching Experiment, School of Basic Medical Science, Xi'an
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Minniti CP, Sable C, Campbell A, Rana S, Ensing G, Dham N, Onyekwere O, Nouraie M, Kato GJ, Gladwin MT, Castro OL, Gordeuk VR. Elevated tricuspid regurgitant jet velocity in children and adolescents with sickle cell disease: association with hemolysis and hemoglobin oxygen desaturation. Haematologica 2009; 94:340-7. [PMID: 19211639 DOI: 10.3324/haematol.13812] [Citation(s) in RCA: 143] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Elevation of echocardiography-determined tricuspid regurgitant jet velocity predicts high systolic pulmonary artery pressure and early mortality in adults with sickle cell disease. The definition, prevalence and clinical correlates of elevated jet velocity have not been established in pediatric patients. The present study tested the hypotheses that elevated jet velocity affects 10% of pediatric patients, is associated with both hemolysis and hypoxia, and has clinical correlates with acute chest syndrome, stroke, transfusion requirement and abnormal 6-minute walk test results. DESIGN AND METHODS A prospective multicenter study of 310 patients aged 3-20 years old with sickle cell disease under basal conditions and 54 matched controls was conducted. A hemolytic index was generated by principal component analysis of the levels of lactate dehydrogenase, aspartate aminotransferase and bilirubin and reticulocyte count. RESULTS Elevated jet velocity (defined as > or =2.60 m/sec based on the mean+/-2 SD in controls) occurred in 32 patients (11.0%) including one child of 3 years old. After adjustment for hemoglobin concentration, systolic blood pressure and left ventricular diastolic function, a 2 SD increase in the hemolytic index was associated with a 4.5-fold increase in the odds of elevated jet velocity (p=0.009) and oxygen saturation < or =98% with a 3.2-fold increase (p=0.028). Two or more episodes of acute chest syndrome had occurred in 28% of children with elevated jet velocity compared to in 13% of other children (p=0.012), more than ten units of blood had been transfused in 39% versus 18% (p=0.017) and stroke had occurred in 19% versus 11% (p=0.2). The distance walked in 6-minute walk tests did not differ significantly, but oxygen saturation declined during the tests in 68% of children with elevated jet velocity compared to in 32% of other children (p=0.0002). CONCLUSIONS According to a pediatric-specific definition the prevalence of elevated jet velocity in this population of young patients with sickle cell disease was 11%. The study provides evidence for independent associations of elevated jet velocity with hemolysis and oxygen desaturation. Further investigations should address whether elevated jet velocity may indicate future complications and whether early intervention is beneficial.
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Estrada KD, Chesler NC. Collagen-related gene and protein expression changes in the lung in response to chronic hypoxia. Biomech Model Mechanobiol 2008; 8:263-72. [PMID: 18642127 DOI: 10.1007/s10237-008-0133-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Accepted: 07/06/2008] [Indexed: 02/06/2023]
Abstract
Collagen accumulation likely contributes to increased vascular and airway impedance in hypoxia-induced pulmonary hypertension (HPH). Collagen exists in multiple subtypes and can accumulate via increased synthesis or decreased degradation. To better understand the individual contributions of fibrillar (FB) and basement membrane (BM) collagen, matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) to pulmonary vascular and airway remodeling in HPH, we investigated the temporal changes in gene and protein expression in the lungs of mice exposed to hypoxia for 0, 3, 6, 10 and 15 days. The earliest and largest change in gene expression was of type I FB collagen, which was significantly increased over control levels at 6, 10 and 15 days of hypoxia (p < 0.05). Type III FB and type IV BM collagen were increased at 10 and 15 days of hypoxia (p < 0.05); MMP and TIMP gene expression levels were typically higher but sometimes lower than control levels at various time points. Collagen protein content was increased in whole lungs as early as 6 days of hypoxia and increased monotonically with longer exposures. However, neither qualitative nor semi-quantitative analysis of immunohistochemistry demonstrated accumulation of type I FB collagen in compartments of the lung other than large airways, suggesting that other collagen subtypes may be important contributors to collagen protein accumulation. These results provide insight into the patterns of gene and protein expression relevant to collagen accumulation in the lung in response to chronic hypoxia, through which we can develop a better understanding of the time course of changes in matrix biology and biomechanics that occur in HPH.
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Affiliation(s)
- Kristine D Estrada
- Biomedical Engineering Department, University of Wisconsin, Madison, Madison, WI 53706-1609, USA
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