1
|
Phillips BG, Wang Y, Ambati S, Ma P, Meagher RB. Airways therapy of obstructive sleep apnea dramatically improves aberrant levels of soluble cytokines involved in autoimmune disease. Clin Immunol 2020; 221:108601. [PMID: 33017651 DOI: 10.1016/j.clim.2020.108601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/21/2020] [Accepted: 09/25/2020] [Indexed: 12/17/2022]
Abstract
Obstructive Sleep Apnea (OSA) damages the health of 35% of adult Americans. Disordered sleep results in increased risk of several autoimmune disorders, but the molecular links to autoimmunity are poorly understood. Herein, we identified four cytokines associated with autoimmune disease, whose median serum levels were significantly different for OSA patients receiving airways therapy, from the levels in untreated OSA patients, APRIL (5.2-fold lower, p = 3.5 × 10-11), CD30 (1.6-fold higher, p = 7.7 × 10-5), IFN-Alpha-2 (2.9-fold higher, p = 9.6 × 10-14) and IL-2 (1.9-fold higher, p = 0.0003). Cytokine levels in airways treated patients were similar to the levels in control subjects. t-SNE and UMAP analysis of these high dimensional patient cytokine data identified only two groups, suggesting a similar global response for all four cytokines to airways therapy. Our findings suggest the levels of these four cytokines may be altered by disordered sleep and perhaps by chronic hypoxia. Therapeutic options are discussed.
Collapse
Affiliation(s)
- Bradley G Phillips
- Clinical and Administrative Pharmacy, University of Georgia, Athens, GA 30602, USA; Clinical and Translational Research Unit, University of Georgia, Athens, GA 30602, USA
| | - Ye Wang
- Department of Statistics, University of Georgia, Athens, GA 30602, USA
| | - Suresh Ambati
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Ping Ma
- Department of Statistics, University of Georgia, Athens, GA 30602, USA
| | - Richard B Meagher
- Department of Genetics, University of Georgia, Athens, GA 30602, USA.
| |
Collapse
|
2
|
Xu J, Ding N, Chen L, Zhang Y, Huang M, Wang Y, Meng Z, Zhang X. Inducers of post-apneic blood pressure fluctuation monitored by pulse transfer time measurement in obstructive sleep apnea varied with syndrome severity. Sleep Breath 2019; 23:769-776. [PMID: 30637570 DOI: 10.1007/s11325-018-1770-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/12/2018] [Accepted: 12/07/2018] [Indexed: 11/26/2022]
Abstract
PURPOSE This study investigated the properties of blood pressure (BP) fluctuation and sympathovagal imbalance with the severity of OSAS. METHODS Nocturnal BP was continuously monitored by polysomnography for mild (n = 33), moderate (n = 34), and severe (n = 37) OSAS patients. Apnea-related systolic BP elevation (△SBP) indicated the amplitude of BP fluctuation. The SBP index, number of △SBP > 10 mmHg/h of sleep, indicated the frequency of significant BP fluctuations. The low frequency/high frequency (LF/HF) ratios indicated heart rate variability and sympathovagal imbalance. RESULTS △SBP and the SBP index were the highest in severe OSAS (12.9 ± 2.3 mmHg and 33.7 ± 14.7/h), followed by moderate OSAS (9.5 ± 2.6 mmHg and 7.1 ± 4.4/h), and mild OSAS (8.3 ± 1.6 mmHg and 3.4 ± 2.1/h). The LF/HF ratios in severe OSAS were significantly higher than that in moderate and mild OSAS. In mild OSAS, arousal played a more important role in BP fluctuation. In moderate OSAS, the oxygen desaturation index (ODI) and the SBP index were correlated. The difference in △SBP induced by hypoxia or by arousal was not significant. In severe OSAS, the apnea-hypopnea index (AHI) and LF/HF ratio were correlated with the SBP index, and △SBP was larger with hypoxia than arousal. CONCLUSIONS BP fluctuation and sympathovagal imbalance were both related to obstructive sleep apnea severity. The influence of arousal and hypoxia on BP fluctuation varied with OSAS severity. TRIAL REGISTRATION NCT02876471.
Collapse
Affiliation(s)
- Jing Xu
- Department of Respiratory, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Road West, Huai'an, 223300, Jiangsu, People's Republic of China
| | - Ning Ding
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China
| | - Liang Chen
- Department of Respiratory, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Road West, Huai'an, 223300, Jiangsu, People's Republic of China
| | - Yi Zhang
- Department of Respiratory, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Road West, Huai'an, 223300, Jiangsu, People's Republic of China
| | - Mao Huang
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China
| | - Yanli Wang
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China
| | - Zili Meng
- Department of Respiratory, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Road West, Huai'an, 223300, Jiangsu, People's Republic of China.
| | - Xilong Zhang
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital with Nanjing Medical University, 300 Guangzhou Road, Nanjing, 210029, China.
| |
Collapse
|
3
|
Zirak P, Gregori-Pla C, Blanco I, Fortuna A, Cotta G, Bramon P, Serra I, Mola A, Solà-Soler J, Giraldo-Giraldo BF, Durduran T, Mayos M. Characterization of the microvascular cerebral blood flow response to obstructive apneic events during night sleep. NEUROPHOTONICS 2018; 5:045003. [PMID: 30681667 PMCID: PMC6215085 DOI: 10.1117/1.nph.5.4.045003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 10/10/2018] [Indexed: 05/09/2023]
Abstract
Obstructive apnea causes periodic changes in cerebral and systemic hemodynamics, which may contribute to the increased risk of cerebrovascular disease of patients with obstructive sleep apnea (OSA) syndrome. The improved understanding of the consequences of an apneic event on the brain perfusion may improve our knowledge of these consequences and then allow for the development of preventive strategies. Our aim was to characterize the typical microvascular, cortical cerebral blood flow (CBF) changes in an OSA population during an apneic event. Sixteen patients (age 58 ± 8 years , 75% male) with a high risk of severe OSA were measured with a polysomnography device and with diffuse correlation spectroscopy (DCS) during one night of sleep with 1365 obstructive apneic events detected. All patients were later confirmed to suffer from severe OSA syndrome with a mean of 83 ± 15 apneas and hypopneas per hour. DCS has been shown to be able to characterize the microvascular CBF response to each event with a sufficient contrast-to-noise ratio to reveal its dynamics. It has also revealed that an apnea causes a peak increase of microvascular CBF ( 30 ± 17 % ) at the end of the event followed by a drop ( - 20 ± 12 % ) similar to what was observed in macrovascular CBF velocity of the middle cerebral artery. This study paves the way for the utilization of DCS for further studies on these populations.
Collapse
Affiliation(s)
- Peyman Zirak
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Clara Gregori-Pla
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Barcelona, Spain
- Address all correspondence to: Clara Gregori-Pla, E-mail:
| | - Igor Blanco
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Ana Fortuna
- Hospital de la Santa Creu i Sant Pau, Department of Respiratory Medicine, Sleep Unit, Barcelona, Spain
| | - Gianluca Cotta
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Pau Bramon
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Isabel Serra
- Centre de Recerca Matemàtica (CRM), Bellaterra, Spain
| | - Anna Mola
- Hospital de la Santa Creu i Sant Pau, Department of Respiratory Medicine, Sleep Unit, Barcelona, Spain
| | - Jordi Solà-Soler
- Universitat Politècnica de Catalunya (UPC)-Barcelona Tech, Department of Automatic Control (ESAII), Barcelona, Spain
- The Barcelona Institute of Science and Technology, Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Beatriz F. Giraldo-Giraldo
- Universitat Politècnica de Catalunya (UPC)-Barcelona Tech, Department of Automatic Control (ESAII), Barcelona, Spain
- The Barcelona Institute of Science and Technology, Institute for Bioengineering of Catalonia (IBEC), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, Barcelona Institute of Science and Technology, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Mercedes Mayos
- Hospital de la Santa Creu i Sant Pau, Department of Respiratory Medicine, Sleep Unit, Barcelona, Spain
- CIBER Enfermedades Respiratorias (CibeRes) (CB06/06), Madrid, Spain
| |
Collapse
|
4
|
Faulk K, Shell B, Nedungadi TP, Cunningham JT. Role of angiotensin-converting enzyme 1 within the median preoptic nucleus following chronic intermittent hypoxia. Am J Physiol Regul Integr Comp Physiol 2017; 312:R245-R252. [PMID: 28003214 PMCID: PMC5336571 DOI: 10.1152/ajpregu.00472.2016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 12/02/2016] [Accepted: 12/15/2016] [Indexed: 01/08/2023]
Abstract
Sustained hypertension is an important consequence of obstructive sleep apnea. An animal model of the hypoxemia associated with sleep apnea, chronic intermittent hypoxia (CIH), produces increased sympathetic nerve activity (SNA) and sustained increases in blood pressure. Many mechanisms have been implicated in the hypertension associated with CIH, including the role of ΔFosB within the median preoptic nucleus (MnPO). Also, the renin-angiotensin system (RAS) has been associated with CIH hypertension. We conducted experiments to determine the possible association of FosB/ΔFosB with a RAS component, angiotensin-converting enzyme 1 (ACE1), within the MnPO following 7 days of CIH. Retrograde tract tracing from the paraventricular nucleus (PVN), a downstream region of the MnPO, was used to establish a potential pathway for FosB/ΔFosB activation of MnPO ACE1 neurons. After CIH, ACE1 cells with FosB/ΔFosB expression increased colocalization with a retrograde tracer that was injected unilaterally within the PVN. Also, Western blot examination showed ACE1 protein expression increasing within the MnPO following CIH. Chromatin immunoprecipitation (ChIP) assays demonstrated an increase in FosB/ΔFosB association with the ACE1 gene within the MnPO following CIH. FosB/ΔFosB may transcriptionally target ACE1 within the MnPO following CIH to affect the downstream PVN region, which may influence SNA and blood pressure.
Collapse
Affiliation(s)
- Katelynn Faulk
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas; and
| | - Brent Shell
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas; and
| | - T Prashant Nedungadi
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas; and
- American Heart Association, Dallas, Texas
| | - J Thomas Cunningham
- Institute for Cardiovascular and Metabolic Diseases, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas; and
| |
Collapse
|
5
|
Mifflin S, Cunningham JT, Toney GM. Neurogenic mechanisms underlying the rapid onset of sympathetic responses to intermittent hypoxia. J Appl Physiol (1985) 2015; 119:1441-8. [PMID: 25997944 DOI: 10.1152/japplphysiol.00198.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 05/19/2015] [Indexed: 11/22/2022] Open
Abstract
Sleep apnea (SA) leads to metabolic abnormalities and cardiovascular dysfunction. Rodent models of nocturnal intermittent hypoxia (IH) are used to mimic arterial hypoxemias that occur during SA. This mini-review focuses on our work examining central nervous system (CNS) mechanisms whereby nocturnal IH results in increased sympathetic nerve discharge (SND) and hypertension (HTN) that persist throughout the 24-h diurnal period. Within the first 1-2 days of IH, arterial pressure (AP) increases even during non-IH periods of the day. Exposure to IH for 7 days biases nucleus tractus solitarius (NTS) neurons receiving arterial chemoreceptor inputs toward increased discharge, providing a substrate for persistent activation of sympathetic outflow. IH HTN is blunted by manipulations that reduce angiotensin II (ANG II) signaling within the forebrain lamina terminalis suggesting that central ANG II supports persistent IH HTN. Inhibition of the hypothalamic paraventricular nucleus (PVN) reduces ongoing SND and acutely lowers AP in IH-conditioned animals. These findings support a role for the PVN, which integrates information ascending from NTS and descending from the lamina terminalis, in sustaining IH HTN. In summary, our findings indicate that IH rapidly and persistently activates a central circuit that includes the NTS, forebrain lamina terminalis, and the PVN. Our working model holds that NTS neuromodulation increases transmission of arterial chemoreceptor inputs, increasing SND via connections with PVN and rostral ventrolateral medulla. Increased circulating ANG II sensed by the lamina terminalis generates yet another excitatory drive to PVN. Together with adaptations intrinsic to the PVN, these responses to IH support rapid onset neurogenic HTN.
Collapse
Affiliation(s)
- Steve Mifflin
- Department of Integrative Physiology and Anatomy, Cardiovascular Research Institute, University of North Texas Health Science Center, Fort Worth, Texas; and
| | - J Thomas Cunningham
- Department of Integrative Physiology and Anatomy, Cardiovascular Research Institute, University of North Texas Health Science Center, Fort Worth, Texas; and
| | - Glenn M Toney
- Department of Physiology, University of Texas Health Science Center, San Antonio, Texas
| |
Collapse
|
6
|
Abstract
Hypertension remains an important cause of morbidity and mortality in patients with chronic kidney disease. It both contributes to and is a consequence of chronic renal dysfunction. There is a high prevalence of hypertension in chronic kidney disease, and rates of control remain sub-optimal. Numerous studies have highlighted the benefit of treating hypertension in reducing the overall mortality as well as progression of renal disease in this population. Non-pharmacologic treatment strategies remain the primary intervention in all patients but are insufficient on their own to control hypertension in most cases. Pharmacologic treatment recommendations, however, vary depending on the specific etiology of disease as well as patient characteristics. Though most classes of anti-hypertensive drugs can be used to lower blood pressure in chronic kidney disease, therapy needs to be selected based on the presence of specific co-morbidities as well as the etiology of the kidney disease. Most patients will require multi-drug therapy for achieving target blood pressure goals. This review discusses the pharmacologic options in management of hypertension in various forms of chronic kidney disease.
Collapse
|
7
|
Mohsenin V, Urbano F. Circulating antiangiogenic proteins in obstructive sleep apnea and hypertension. Respir Med 2011; 105:801-7. [DOI: 10.1016/j.rmed.2011.01.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/03/2011] [Accepted: 01/05/2011] [Indexed: 01/09/2023]
|
8
|
Abstract
Sleep-induced apnea and disordered breathing refers to intermittent, cyclical cessations or reductions of airflow, with or without obstructions of the upper airway (OSA). In the presence of an anatomically compromised, collapsible airway, the sleep-induced loss of compensatory tonic input to the upper airway dilator muscle motor neurons leads to collapse of the pharyngeal airway. In turn, the ability of the sleeping subject to compensate for this airway obstruction will determine the degree of cycling of these events. Several of the classic neurotransmitters and a growing list of neuromodulators have now been identified that contribute to neurochemical regulation of pharyngeal motor neuron activity and airway patency. Limited progress has been made in developing pharmacotherapies with acceptable specificity for the treatment of sleep-induced airway obstruction. We review three types of major long-term sequelae to severe OSA that have been assessed in humans through use of continuous positive airway pressure (CPAP) treatment and in animal models via long-term intermittent hypoxemia (IH): 1) cardiovascular. The evidence is strongest to support daytime systemic hypertension as a consequence of severe OSA, with less conclusive effects on pulmonary hypertension, stroke, coronary artery disease, and cardiac arrhythmias. The underlying mechanisms mediating hypertension include enhanced chemoreceptor sensitivity causing excessive daytime sympathetic vasoconstrictor activity, combined with overproduction of superoxide ion and inflammatory effects on resistance vessels. 2) Insulin sensitivity and homeostasis of glucose regulation are negatively impacted by both intermittent hypoxemia and sleep disruption, but whether these influences of OSA are sufficient, independent of obesity, to contribute significantly to the "metabolic syndrome" remains unsettled. 3) Neurocognitive effects include daytime sleepiness and impaired memory and concentration. These effects reflect hypoxic-induced "neural injury." We discuss future research into understanding the pathophysiology of sleep apnea as a basis for uncovering newer forms of treatment of both the ventilatory disorder and its multiple sequelae.
Collapse
Affiliation(s)
- Jerome A Dempsey
- The John Rankin Laboratory of Pulmonary Medicine, Departments of Population Health Sciences and of Orthopedics and Rehabilitation, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53706, USA.
| | | | | | | |
Collapse
|
9
|
Alzoghaibi MA, Bahammam ASO. Lipid peroxides, superoxide dismutase and circulating IL-8 and GCP-2 in patients with severe obstructive sleep apnea: a pilot study. Sleep Breath 2009; 9:119-26. [PMID: 15988615 DOI: 10.1007/s11325-005-0022-1] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Obstructive sleep apnea (OSA) is associated with cardiovascular morbidity and mortality and many other physiological and immunological disorders. An increase in hypoxia due to OSA may cause generation of reactive oxygen species (ROS). ROS are toxic to biomembranes and may lead to peroxidation of lipids. An increase in systemic biomarkers of inflammation and oxidative stress has been found in patients with OSA. The first aim of this study was to test the hypothesis that OSA is linked to increased oxidative stress (lipid peroxidation) and decreased antioxidant defense [superoxide dismutase (SOD)]. The second aim was to measure the serum levels of neutrophil chemokines [interleukin-8 (IL-8)], and granulocyte chemotactic protein-2 (GCP-2) in OSA patients. Twenty five patients with severe OSA and 17 healthy subjects were recruited. IL-8 and GCP-2 were measured in the serum by a specific enzyme immunoassay kit. Oxidative stress level was quantitated by measurement of thiobarbituric acid reactive substances. SOD enzymatic activity was measured by purely chemical system based on NAD(P)H oxidation. Mean SOD and lipid peroxidation concentrations of patients were not significantly different from those of control subjects (0.29+/-0.015 vs 0.31+/-0.01 U/ml and 4.64+/-0.57 vs 4.62+/-0.54 mmol/ml, respectively). Higher concentrations of IL-8 and GCP-2 were found in OSA patients (198.8+/-4.76 vs 180.83+/-3.38 and 383.34+/-46.19 vs 218+/-13.16 pg/ml, respectively, p<0.005). The present study does not support the hypothesis that OSA is linked to increased oxidative stress and decreased antioxidant defense. On the other hand, it suggests that systemic inflammation characterizes OSA patients.
Collapse
Affiliation(s)
- Mohammed A Alzoghaibi
- College of Medicine, King Saud University, P.O. Box 2925, 11461, Riyadh, Saudi Arabia.
| | | |
Collapse
|
10
|
Tabata R, Yin M, Nakayama M, Ikeda M, Hata T, Shibata Y, Itasaka Y, Ishikawa K, Okawa M, Miyazaki S. A preliminary study on the influence of obstructive sleep apnea upon cumulative parasympathetic system activity. Auris Nasus Larynx 2008; 35:242-6. [PMID: 18242028 DOI: 10.1016/j.anl.2007.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Revised: 09/08/2007] [Accepted: 11/17/2007] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Although the autonomic nervous system plays a key role in mediating cardiovascular changes during obstructive sleep apnea (OSA), parasympathetic nervous system (PNS) activity during sleep apnea has not yet been sufficiently investigated. This study is to discuss the relationship between PNS activity and OSA. METHODS Polysomnography recording was carried out in 76 patients (71 male and 5 female) with OSA. Cumulative PNS activity during sleep for each patient was derived from time series data of electrocardiogram (ECG) and analyzed by coarse graining spectral analysis of heart rate variability. The correlation between cumulative PNS activity and apnea-hypopnea index (AHI) was then discussed. RESULTS Cumulative PNS activity and PNS peaks during sleep were lowly but significantly correlated with OSA severity (r=-0.344, p<0.005; and r=-0.266, p<0.05 respectively), and a linear regression equation could be established. Furthermore, significant correlation was also observed in the adult groups and in the moderate and severe groups, but not in the juvenile and the elderly and mild groups. CONCLUSION These findings indicated that PNS function was obviously influenced by OSA during sleep. Cumulative PNS activity level might also serve as a useful parameter for the evaluation of OSA.
Collapse
Affiliation(s)
- Ryoko Tabata
- Division of Adult Nursing, Department of Clinical Nursing, Shiga University of Medical Science, Seta, Otsu 520-2192, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
|
12
|
Allahdadi KJ, Duling LC, Walker BR, Kanagy NL. Eucapnic intermittent hypoxia augments endothelin-1 vasoconstriction in rats: role of PKCdelta. Am J Physiol Heart Circ Physiol 2007; 294:H920-7. [PMID: 18083893 DOI: 10.1152/ajpheart.01264.2007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We reported previously that simulating sleep apnea by exposing rats to eucapnic intermittent hypoxia (E-IH) causes endothelin-dependent hypertension and increases constrictor sensitivity to endothelin-1 (ET-1). In addition, augmented ET-1-induced constriction in small mesenteric arteries (sMA) is mediated by increased Ca(2+) sensitization independent of Rho-associated kinase. We hypothesized that exposing rats to E-IH augments ET-1-mediated vasoconstriction by increasing protein kinase C (PKC)-dependent Ca(2+) sensitization. In sMA, the nonselective PKC inhibitor GF-109203x (3 microM) significantly inhibited ET-1-stimulated constriction in E-IH arteries but did not affect ET-1-stimulated constriction in sham arteries. Phospholipase C inhibitor U-73122 (1 microM) also inhibited constriction by ET-1 in E-IH but not sham sMA. In contrast, the classical PKC (cPKC) inhibitor Gö-6976 (1 microM) had no effect on ET-1-mediated vasoconstriction in either group, but a PKCdelta-selective inhibitor (rottlerin, 3 microM) significantly decreased ET-1-mediated constriction in E-IH but not in sham sMA. ET-1 increased PKCdelta phosphorylation in E-IH but not sham sMA. In contrast, ET-1 constriction in thoracic aorta from both sham and E-IH rats was inhibited by Gö-6976 but not by rottlerin. These observations support our hypothesis that E-IH exposure significantly increases ET-1-mediated constriction of sMA through PKCdelta activation and modestly augments ET-1 contraction in thoracic aorta through activation of one or more cPKC isoforms. Therefore, upregulation of a PKC pathway may contribute to elevated ET-1-dependent vascular resistance in this model of hypertension.
Collapse
Affiliation(s)
- Kyan J Allahdadi
- Deparment of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM 87131, USA
| | | | | | | |
Collapse
|
13
|
Allahdadi KJ, Walker BR, Kanagy NL. ROK contribution to endothelin-mediated contraction in aorta and mesenteric arteries following intermittent hypoxia/hypercapnia in rats. Am J Physiol Heart Circ Physiol 2007; 293:H2911-8. [PMID: 17720771 DOI: 10.1152/ajpheart.00217.2007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We reported previously that intermittent hypoxia with CO(2) to maintain eucapnia (IH-C) elevates plasma endothelin-1 (ET-1) and arterial pressure. In small mesenteric arteries (sMA; inner diameter = 150 microm), IH-C augments ET-1 constrictor sensitivity but diminishes ET-1-induced increases in intracellular Ca(2+) concentration, suggesting IH-C exposure increases both ET-1 levels and ET-1-stimulated Ca(2+) sensitization. Because Rho-associated kinase (ROK) can mediate Ca(2+) sensitization, we hypothesized that augmented vasoconstrictor sensitivity to ET-1 in arteries from IH-C-exposed rats is dependent on ROK activation. In thoracic aortic rings, ET-1 contraction was not different between groups, but ROK inhibition (Y-27632, 3 and 10 microM) attenuated ET-1 contraction more in IH-C than in sham arteries (50 +/- 11 and 78 +/- 7% vs. 41 +/- 12 and 48 +/- 9% inhibition, respectively). Therefore, ROK appears to contribute more to ET-1 contraction in IH-C than in sham aorta. In sMA, ROK inhibitors did not affect ET-1-mediated constriction in sham arteries and only modestly inhibited it in IH-C arteries. In ionomycin-permeabilized sMA with intracellular Ca(2+) concentration held at basal levels, Y-27632 did not affect ET-1-mediated constriction in either IH-C or sham sMA and ET-1 did not stimulate ROK translocation. In contrast, inhibition of myosin light-chain kinase (ML-9, 100 microM) prevented ET-1-mediated constriction in sMA from both groups. Therefore, IH-C exposure increases ET-1 vasoconstrictor sensitivity in sMA but not in aorta. Furthermore, ET-1 constriction is myosin light-chain kinase dependent and mediated by Ca(2+) sensitization that is independent of ROK activation in sMA but not aorta. Thus ET-1-mediated signaling in aorta and sMA is altered by IH-C but is dependent on different second messenger systems in small vs. large arteries.
Collapse
Affiliation(s)
- Kyan J Allahdadi
- Department of Cell Biology and Physiology, Vascular Physiology Group, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | | | | |
Collapse
|
14
|
|
15
|
Norman D, Loredo JS, Nelesen RA, Ancoli-Israel S, Mills PJ, Ziegler MG, Dimsdale JE. Effects of continuous positive airway pressure versus supplemental oxygen on 24-hour ambulatory blood pressure. Hypertension 2006; 47:840-5. [PMID: 16585412 DOI: 10.1161/01.hyp.0000217128.41284.78] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Obstructive sleep apnea (OSA) is associated with recurrent episodes of nocturnal hypoxia and increased risk for development of systemic hypertension. Prior studies have been limited, however, in their ability to show reduction in blood pressure after continuous positive airway pressure (CPAP) therapy, and the effect of supplemental oxygen alone on blood pressure in OSA has not been evaluated. We performed a randomized, double-blind, placebo-controlled study comparing the effects of 2 weeks of CPAP versus sham-CPAP versus supplemental nocturnal oxygen on 24-hour ambulatory blood pressure in 46 patients with moderate-severe OSA. We found that 2 weeks of CPAP therapy resulted in a significant reduction in daytime mean arterial and diastolic blood pressure and nighttime systolic, mean, and diastolic blood pressure (all Ps <0.05). Although nocturnal supplemental oxygen therapy improved oxyhemoglobin saturation, it did not affect blood pressure. We conclude that CPAP therapy reduces both daytime and nighttime blood pressure in patients with OSA, perhaps through mechanisms other than improvement of nocturnal oxyhemoglobin saturation.
Collapse
Affiliation(s)
- Daniel Norman
- Department of Medicine, School of Medicine, University of California, San Diego, CA, USA.
| | | | | | | | | | | | | |
Collapse
|
16
|
Fan C, Iacobas DA, Zhou D, Chen Q, Lai JK, Gavrialov O, Haddad GG. Gene expression and phenotypic characterization of mouse heart after chronic constant or intermittent hypoxia. Physiol Genomics 2005; 22:292-307. [PMID: 15928208 PMCID: PMC2856928 DOI: 10.1152/physiolgenomics.00217.2004] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Chronic constant hypoxia (CCH), such as in pulmonary diseases or high altitude, and chronic intermittent hypoxia (CIH), such as in sleep apnea, can lead to major changes in the heart. Molecular mechanisms underlying these cardiac alterations are not well understood. We hypothesized that changes in gene expression could help to delineate such mechanisms. The current study used a neonatal mouse model in CCH or CIH combined with cDNA microarrays to determine changes in gene expression in the CCH or CIH mouse heart. Both CCH and CIH induced substantial alterations in gene expression. In addition, a robust right ventricular hypertrophy and cardiac enlargement was found in CCH- but not in CIH-treated mouse heart. On one hand, upregulation in RNA and protein levels of eukaryotic translation initiation factor-2alpha and -4E (eIF-2alpha and eIF-4E) was found in CCH, whereas eIF-4E was downregulated in 1- and 2-wk CIH, suggesting that eIF-4E is likely to play an important role in the cardiac hypertrophy observed in CCH-treated mice. On the other hand, the specific downregulation of heart development-related genes (e.g., notch gene homolog-1, MAD homolog-4) and the upregulation of proteolysis genes (e.g., calpain-5) in the CIH heart can explain the lack of hypertrophy in CIH. Interestingly, apoptosis was enhanced in CCH but not CIH, and this was correlated with an upregulation of proapoptotic genes and downregulation of anti-apoptotic genes in CCH. In summary, our results indicate that 1) the pattern of gene response to CCH is different from that of CIH in mouse heart, and 2) the identified expression differences in certain gene groups are helpful in dissecting mechanisms responsible for phenotypes observed.
Collapse
Affiliation(s)
- Chenhao Fan
- Departments of Pediatrics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
| | | | | | | | | | | | | |
Collapse
|
17
|
Jean-Louis G, Zizi F, Casimir G, DiPalma J, Mukherji R. Sleep-disordered breathing and hypertension among African Americans. J Hum Hypertens 2005; 19:485-90. [PMID: 15800665 DOI: 10.1038/sj.jhh.1001855] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study investigated differences in sleep-disordered breathing (SDB) between hypertensives without a family history of hypertension and hypertensives with a family history. Furthermore, it examined whether these two groups differed in the severity of SDB. Patients were African Americans (n=162, mean age=51.19+/-13.77 years; mean body mass index (BMI)=37.85+/-9.51 kg/m2, male=57%), who were referred to the clinic because of a sleep complaint. Sleep was recorded in the laboratory using standard physiological parameters; all parameters were analysed by a trained scorer. Altogether, 91% of the patients received an SDB diagnosis. Of these patients, 25% were hypertensives without a family history, 20% were hypertensives with a family history, and 55% were normotensives. We found a significant difference between these patient groups regarding the severity of SDB (F14,158=1.823, P<0.05), but no significant group difference was observed in the rate of SDB. Increasing weight was accompanied by increasing severity of SDB. The finding that hypertensive patients with or without a positive family history showed worse oxygenation and respiratory characteristics than did normotensives is consistent with previous research. Of note, hypertensives reporting a family history were characterized by a greater number of oxygen desaturations and apnoea hypopnoea index than those typified only by a current diagnosis of hypertension. Hypertensives with a family history are likely to show a profile of greater blood pressure, higher BMI, and more severe SDB, which by all accounts are more common among African Americans.
Collapse
Affiliation(s)
- G Jean-Louis
- Department of Psychiatry and Ophthalmology, SUNY Downstate Medical Center, Brooklyn, NY 11203, USA.
| | | | | | | | | |
Collapse
|
18
|
Lin L, Finn L, Zhang J, Young T, Mignot E. Angiotensin-converting enzyme, sleep-disordered breathing, and hypertension. Am J Respir Crit Care Med 2004; 170:1349-53. [PMID: 15447944 DOI: 10.1164/rccm.200405-616oc] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The angiotensin-converting enzyme (ACE) gene insertion/deletion polymorphism influences ACE activity, cardiovascular risk, blood pressure, and possibly the risk of developing Alzheimer's dementia. We explored the association of the insertion/deletion polymorphism with sleep-disordered breathing (SDB) and hypertension in 1,100 subjects of the Wisconsin Sleep Cohort. The polymorphism did not influence body mass index or the occurrence of SDB, but was dose-dependently associated with blood pressure. Interestingly, SDB and the insertion/deletion polymorphism interacted significantly to modulate blood pressure independently of age, sex, ethnicity, and body mass index. Most specifically, the association of the deletion allele with hypertension was most pronounced in subjects with mild to moderate degrees of sleep apnea (5 < or = apnea-hypopnea index < or = 30). We hypothesize that in the absence of SDB the effect of the deletion allele alone may not be sufficient to increase blood pressure. At severe levels of SDB, the effect of sleep apnea on blood pressure overwhelms any association of the deletion allele with hypertension and occurs independent of any ACE gene genotype.
Collapse
Affiliation(s)
- Ling Lin
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, CA 94304-5742, USA
| | | | | | | | | |
Collapse
|