Hydrogen gas attenuates embryonic gene expression and prevents left ventricular remodeling induced by intermittent hypoxia in cardiomyopathic hamsters

2014 ◽  
Vol 307 (11) ◽  
pp. H1626-H1633 ◽  
Author(s):  
Ryuji Kato ◽  
Atsuo Nomura ◽  
Aiji Sakamoto ◽  
Yuki Yasuda ◽  
Koyuha Amatani ◽  
...  

The prevalence of sleep apnea is very high in patients with heart failure (HF). The aims of this study were to investigate the influence of intermittent hypoxia (IH) on the failing heart and to evaluate the antioxidant effect of hydrogen gas. Normal male Syrian hamsters ( n = 22) and cardiomyopathic (CM) hamsters ( n = 33) were exposed to IH (repeated cycles of 1.5 min of 5% oxygen and 5 min of 21% oxygen for 8 h during the daytime) or normoxia for 14 days. Hydrogen gas (3.05 vol/100 vol) was inhaled by some CM hamsters during hypoxia. IH increased the ratio of early diastolic mitral inflow velocity to mitral annulus velocity (E/e′, 21.8 vs. 16.9) but did not affect the LV ejection fraction (EF) in normal Syrian hamsters. However, IH increased E/e′ (29.4 vs. 21.5) and significantly decreased the EF (37.2 vs. 47.2%) in CM hamsters. IH also increased the cardiomyocyte cross-sectional area (672 vs. 443 μm2) and interstitial fibrosis (29.9 vs. 9.6%), along with elevation of oxidative stress and superoxide production in the left ventricular (LV) myocardium. Furthermore, IH significantly increased the expression of brain natriuretic peptide, β-myosin heavy chain, c- fos, and c- jun mRNA in CM hamsters. Hydrogen gas inhalation significantly decreased both oxidative stress and embryonic gene expression, thus preserving cardiac function in CM hamsters. In conclusion, IH accelerated LV remodeling in CM hamsters, at least partly by increasing oxidative stress in the failing heart. These findings might explain the poor prognosis of patients with HF and sleep apnea.

2011 ◽  
Vol 301 (3) ◽  
pp. H1062-H1069 ◽  
Author(s):  
Tetsuya Hayashi ◽  
Toshitaka Yoshioka ◽  
Kenichi Hasegawa ◽  
Masatoshi Miyamura ◽  
Tatsuhiko Mori ◽  
...  

Sleep apnea syndrome increases the risk of cardiovascular morbidity and mortality. We previously reported that intermittent hypoxia increases superoxide production in a manner dependent on nicotinamide adenine dinucleotide phosphate and accelerates adverse left ventricular (LV) remodeling. Recent studies have suggested that hydrogen (H2) may have an antioxidant effect by reducing hydroxyl radicals. In this study, we investigated the effects of H2 gas inhalation on lipid metabolism and LV remodeling induced by intermittent hypoxia in mice. Male C57BL/6J mice ( n = 62) were exposed to intermittent hypoxia (repetitive cycle of 1-min periods of 5 and 21% oxygen for 8 h during daytime) for 7 days. H2 gas (1.3 vol/100 vol) was given either at the time of reoxygenation, during hypoxic conditions, or throughout the experimental period. Mice kept under normoxic conditions served as controls ( n = 13). Intermittent hypoxia significantly increased plasma levels of low- and very low-density cholesterol and the amount of 4-hydroxy-2-nonenal-modified protein adducts in the LV myocardium. It also upregulated mRNA expression of tissue necrosis factor-α, interleukin-6, and brain natriuretic peptide, increased production of superoxide, and induced cardiomyocyte hypertrophy, nuclear deformity, mitochondrial degeneration, and interstitial fibrosis. H2 gas inhalation significantly suppressed these changes induced by intermittent hypoxia. In particular, H2 gas inhaled at the timing of reoxygenation or throughout the experiment was effective in preventing dyslipidemia and suppressing superoxide production in the LV myocardium. These results suggest that inhalation of H2 gas was effective for reducing oxidative stress and preventing LV remodeling induced by intermittent hypoxia relevant to sleep apnea.


2002 ◽  
Vol 283 (6) ◽  
pp. H2612-H2619 ◽  
Author(s):  
Sanjay Srivastava ◽  
Bysani Chandrasekar ◽  
Aruni Bhatnagar ◽  
Sumanth D. Prabhu

Lipid peroxidation-derived aldehydes (LP-DA) can propagate oxidative injury and are detoxified by the aldose reductase (AR) enzyme pathway in myocardium. Whether there are alterations in the AR axis in heart failure (HF) is unknown. Sixteen instrumented dogs were studied before and after either 24 h or 4 wk of rapid left ventricular (LV) pacing (early and late HF, respectively). Six unpaced dogs served as controls. In early HF, there was subtle depression of LV performance (maximum rate of LV pressure rise, P < 0.05 vs. baseline) but no chamber enlargement, whereas in late HF there was significant ( P < 0.05) contractile depression and LV dilatation. Oxidative stress was increased at both time points, indexed by tissue malondialdehyde, total glutathione, and free C6–C9 LP-DA ( P < 0.025 vs. control). AR protein levels and activity decreased progressively during HF ( P < 0.025 early/late HF vs. control); however, AR mRNA expression decreased only in late HF ( P < 0.005 vs. early HF and control). DNA binding of tonicity-responsive enhancer binding protein (TonEBP, a transcriptional regulator of AR) paralleled AR mRNA, declining >50% in late HF ( P < 0.025 vs. control). We conclude that AR levels and attendant myocardial capacity to detoxify LP-DA decline during the development of HF. In early HF, decreased AR occurs due to a translational or posttranslational mechanism, whereas in late HF reduced TonEBP transcriptional activation and AR downregulation contribute significantly. Reduced AR-mediated LP-DA metabolism contributes importantly to LP-DA accumulation in the failing heart and thus may augment chronic oxidative injury.


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1184 ◽  
Author(s):  
Peng Guan ◽  
Zhi-Min Sun ◽  
Li-Fei Luo ◽  
Ya-Shuo Zhao ◽  
Sheng-Chang Yang ◽  
...  

Iron-induced oxidative stress has been found to be a central player in the pathogenesis of kidney injury. Recent studies have indicated H2 can be used as a novel antioxidant to protect cells. The present study was designed to investigate the protective effects of H2 against chronic intermittent hypoxia (CIH)-induced renal injury and its correlation mechanism involved in iron metabolism. We found that CIH-induced renal iron overloaded along with increased apoptosis and oxidative stress. Iron accumulates mainly occurred in the proximal tubule epithelial cells of rats as showed by Perl’s stain. Moreover, we found that CIH could promote renal transferrin receptor and divalent metal transporter-1 expression, inhibit ceruloplasmin expression. Renal injury, apoptosis and oxidative stress induced by CIH were strikingly attenuated in H2 treated rats. In conclusion, hydrogen may attenuate CIH-induced renal injury at least partially via inhibiting renal iron overload.


2013 ◽  
Vol 115 (11) ◽  
pp. 1694-1704 ◽  
Author(s):  
Robert M. Douglas ◽  
Karen Bowden ◽  
Jennifer Pattison ◽  
Alexander B. Peterson ◽  
Joseph Juliano ◽  
...  

Patients with obstructive sleep apnea, who experience episodic hypoxia and hypercapnia during sleep, often demonstrate increased inflammation, oxidative stress, and dyslipidemia. We hypothesized that sleep apnea patients would be predisposed to the development of atherosclerosis. To dissect the mechanisms involved, we developed an animal model in mice whereby we expose mice to intermittent hypoxia/hypercapnia (IHH) in normobaric environments. Two- to three-month-old low-density lipoprotein receptor deficient ( Ldlr−/−) mice were fed a high-fat diet for 8 or 16 wk while being exposed to IHH for either 10 h/day or 24 h/day. Plasma lipid levels, pulmonary artery and aortic atherosclerotic lesions, and cardiac function were then assayed. Surprisingly, atherosclerosis in the aorta of IHH mice was similar compared with controls. However, in IHH mice, atherosclerosis was markedly increased in the trunk and proximal branches of the pulmonary artery of exposed mice; even though plasma cholesterol and triglycerides were lower than in controls. Hemodynamic analysis revealed that right ventricular maximum pressure and isovolumic relaxation constant were significantly increased in IHH exposed mice and left ventricular % fractional shortening was reduced. In conclusion, 1) Intermittent hypoxia/hypercapnia remarkably accelerated atherosclerotic lesions in the pulmonary artery of Ldlr−/− mice and 2) increased lesion formation in the pulmonary artery was associated with right and left ventricular dysfunction. These findings raise the possibility that patients with obstructive sleep apnea may be susceptible to atherosclerotic disease in the pulmonary vasculature, an observation that has not been previously recognized.


2016 ◽  
Vol 120 (8) ◽  
pp. 982-990 ◽  
Author(s):  
Peiying Pai ◽  
Ching Jung Lai ◽  
Ching-Yuang Lin ◽  
Yi-Fan Liou ◽  
Chih-Yang Huang ◽  
...  

Only very limited information regarding the protective effects of the superoxide anion scavenger on chronic intermittent hypoxia-induced cardiac apoptosis is available. The purpose of this study is to evaluate the effects of the superoxide anion scavenger on cardiac apoptotic and prosurvival pathways in rats with sleep apnea. Forty-two Sprague-Dawley rats were divided into three groups, rats with normoxic exposure (Control, 21% O2, 1 mo), rats with chronic intermittent hypoxia exposure (Hypoxia, 3-7% O2 vs. 21% O2 per 40 s cycle, 8 h per day, 1 mo), and rats with pretreatment of the superoxide anion scavenger and chronic intermittent hypoxia exposure (Hypoxia-O2−-Scavenger, MnTMPyP pentachloride, 1 mg/kg ip per day; 3–7% O2 vs. 21% O2 per 40 s cycle, 8 h per day, 1 mo) at 5–6 mo of age. After 1 mo, the protein levels and apoptotic cells of excised hearts from three groups were measured by Western blotting and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assay. The superoxide anion scavenger decreased hypoxia-induced myocardial architecture abnormalities, left ventricular hypertrophy, and TUNEL-positive apoptosis. The superoxide anion scavenger decreased hypoxia-induced Fas ligand, Fas death receptors, Fas-associated death domain (FADD), activated caspase-8, and activated caspase-3 (Fas-dependent apoptotic pathway) as well as Bad, activated caspase-9 and activated caspase-3 (mitochondria-dependent apoptotic pathway), endonuclease G (EndoG), apoptosis-inducing factor (AIF), and TUNEL-positive apoptosis. The superoxide anion scavenger increased IGF-1, IGF-1R, p-PI3k, p-Akt, p-Bad, Bcl-2, and Bcl-xL (survival pathway). Our findings imply that the superoxide anion scavenger might prevent cardiac Fas-mediated and mitochondrial-mediated apoptosis and enhance the IGF-1-related survival pathway in chronic intermittent hypoxia. The superoxide anion scavenger may prevent chronic sleep apnea-enhanced cardiac apoptotic pathways and enhances cardiac survival pathways.


Antioxidants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 476
Author(s):  
Bernardo U. Peres ◽  
AJ Hirsch Allen ◽  
Aditi Shah ◽  
Nurit Fox ◽  
Ismail Laher ◽  
...  

Oxidative stress (OS) drives cardiometabolic diseases. Intermittent hypoxia consistently increases oxidative stress markers. Obstructive sleep apnea (OSA) patients experience intermittent hypoxia and an increased rate of cardiovascular disease, however, the impact of OSA on OS markers is not clear. The objective was to assess relationships between OSA severity and biomarker levels. Patients with suspected OSA referred for a polysomnogram (PSG) provided fasting blood sample. Plasma levels of 8-isoprostane, 8-hydroxydeoxyguanosine (8-OHdG), and superoxide dismutase (SOD) were measured. The relationship between OSA and OS was assessed both before and after controlling for confounders (age, sex, smoking history, history of cardiovascular disease, ethnicity, diabetes, statin usage, body mass index (BMI)). 402 patients were studied (68% male, mean age ± SD = 50.8 ± 11.8 years, apnea-hypopnea index (AHI) = 22.2 ± 21.6 events/hour, BMI = 31.62 ± 6.49 kg/m2). In a multivariable regression, the AHI significantly predicted 8-isoprostane levels (p = 0.0008) together with age and statin usage; AHI was not a predictor of 8-OHdG or SOD. Female sex (p < 0.0001) and no previous history of cardiovascular disease (p = 0.002) were associated with increased antioxidant capacity. Circulating 8-isoprostane levels may be a promising biomarker of the severity of oxidative stress in OSA patients. Prospective studies are needed to determine whether this biomarker is associated with long-term cardiometabolic complications in OSA.


2020 ◽  
Vol 21 (3) ◽  
pp. 999
Author(s):  
Yung-Che Chen ◽  
Po-Yuan Hsu ◽  
Mao-Chang Su ◽  
Chien-Hung Chin ◽  
Chia-Wei Liou ◽  
...  

The purpose of this study is to explore the anti-inflammatory role of microRNAs (miR)-21 and miR-23 targeting the TLR/TNF-α pathway in response to chronic intermittent hypoxia with re-oxygenation (IHR) injury in patients with obstructive sleep apnea (OSA). Gene expression levels of the miR-21/23a, and their predicted target genes were assessed in peripheral blood mononuclear cells from 40 treatment-naive severe OSA patients, and 20 matched subjects with primary snoring (PS). Human monocytic THP-1 cell lines were induced to undergo apoptosis under IHR exposures, and transfected with miR-21-5p mimic. Both miR-21-5p and miR-23-3p gene expressions were decreased in OSA patients as compared with that in PS subjects, while TNF-α gene expression was increased. Both miR-21-5p and miR-23-3p gene expressions were negatively correlated with apnea hypopnea index and oxygen desaturation index, while TNF-α gene expression positively correlated with apnea hypopnea index. In vitro IHR treatment resulted in decreased miR-21-5p and miR-23-3p expressions. Apoptosis, cytotoxicity, and gene expressions of their predicted target genes—including TNF-α, ELF2, NFAT5, HIF-2α, IL6, IL6R, EDNRB, and TLR4—were all increased in response to IHR, while all were reversed with miR-21-5p mimic transfection under IHR condition. The findings provide biological insight into mechanisms by which IHR-suppressed miRs protect cell apoptosis via inhibit inflammation, and indicate that over-expression of the miR-21-5p may be a new therapy for OSA.


2007 ◽  
Vol 102 (5) ◽  
pp. 1806-1814 ◽  
Author(s):  
Ah-Mee Park ◽  
Yuichiro J. Suzuki

Obstructive sleep apnea is associated with increased risk for cardiovascular diseases. As obstructive sleep apnea is characterized by episodic cycles of hypoxia and normoxia during sleep, we investigated effects of intermittent hypoxia (IH) on ischemia-reperfusion-induced myocardial injury. C57BL/6 mice were subjected to IH (2 min 6% O2 and 2 min 21% O2) for 8 h/day for 1, 2, or 4 wk; isolated hearts were then subjected to ischemia-reperfusion. IH for 1 or 2 wk significantly enhanced ischemia-reperfusion-induced myocardial injury. However, enhanced cardiac damage was not seen in mice treated with 4 wk of IH, suggesting that the heart has adapted to chronic IH. Ischemia-reperfusion-induced lipid peroxidation and protein carbonylation were enhanced with 2 wk of IH, while, with 4 wk, oxidative stress was normalized to levels in animals without IH. H2O2 scavenging activity in adapted hearts was higher after ischemia-reperfusion, suggesting the increased antioxidant capacity. This might be due to the involvement of thioredoxin, as the expression level of this protein was increased, while levels of other antioxidant enzymes were unchanged. In the heart from mice treated with 2 wk of IH, ischemia-reperfusion was found to decrease thioredoxin. Ischemia-reperfusion injury can also be enhanced when thioredoxin reductase was inhibited in control hearts. These results demonstrate that IH changes the susceptibility of the heart to oxidative stress in part via alteration of thioredoxin.


2012 ◽  
Vol 44 (16) ◽  
pp. 819-827 ◽  
Author(s):  
Alison J. Kriegel ◽  
Daniela N. Didier ◽  
Peigang Li ◽  
Jozef Lazar ◽  
Andrew S. Greene

The SS-16BN/Mcwi consomic rat was produced by the introgression of chromosome 16 from the Brown Norway (BN/NHsdMcwi) rat onto the genetic background of the Dahl salt-sensitive (SS/Mcwi) rat by marker-assisted breeding. We have previously shown that the normotensive SS-16BN/Mcwi consomic strain is better protected from developing left ventricular dysfunction and fibrosis with aging than the hypertensive SS/Mcwi parental strain; however, the mechanism of this protection was not clear since the SS-16BN/Mcwi had both lowered blood pressure and an altered genetic background compared with SS/Mcwi. Microarray analysis of SS-16BN/Mcwi and SS/Mcwi left ventricle tissue and subsequent protein pathway analysis were used to identify alterations in gene expression in signaling pathways involved with the observed cardioprotection on the SS background. The SS-16BN/Mcwi rats exhibited much higher mRNA levels of expression of transcription factor JunD, a gene found on chromosome 16. Additionally, high levels of differential gene expression were found in pathways involved with angiogenesis, oxidative stress, and growth factor signaling. We tested the physiological relevance of these pathways by experimentally determining the responsiveness of neonatal cardiomyocytes to factors from identified pathways and found that cells isolated from SS-16BN/Mcwi rats had a greater growth response to epidermal growth factor and endothelin-1 than those from parental SS/Mcwi. We also demonstrate that the SS-16BN/Mcwi is better protected from developing fibrosis with surgically elevated afterload than other normotensive strains, indicating that gene-gene interactions resulting from BN chromosomal substitution confer specific cardioprotection. When combined with our previous findings, these data suggest that that SS-16BN/Mcwi may have an increased angiogenic potential and better protection from oxidative stress than the parental SS/Mcwi strain. Additionally, the early transient idiopathic left ventricular hypertrophy in the SS-16BN/Mcwi may be related to altered myocyte sensitivity to growth factors.


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