Loss of NOX2 (gp91phox) prevents oxidative stress and progression to advanced heart failure

2014 ◽  
Vol 127 (5) ◽  
pp. 331-340 ◽  
Author(s):  
Nirmal Parajuli ◽  
Vaibhav B. Patel ◽  
Wang Wang ◽  
Ratnadeep Basu ◽  
Gavin Y. Oudit

Increased oxidative stress is a key driver of heart failure progression. We have shown that loss of NOX2 (NADPH oxidase 2) prevented the development of heart failure, and direct inhibition of NOX2 may have therapeutic effects in advanced heart failure.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yong Wang ◽  
Chun Li ◽  
Yuli Ouyang ◽  
Tianjiao Shi ◽  
Xiaomin Yang ◽  
...  

We aim to investigate the therapeutic effects of QSYQ, a drug of heart failure (HF) in clinical practice in China, on a rat heart failure (HF) model. 3 groups were divided: HF model group (LAD ligation), QSYQ group (LAD ligation and treated with QSYQ), and sham-operated group. After 4 weeks, rats were sacrificed for cardiac injury measurements. Rats with HF showed obvious histological changes including necrosis and inflammation foci, elevated ventricular remodeling markers levels(matrix metalloproteinases-2, MMP-2), deregulated ejection fraction (EF) value, increased formation of oxidative stress (Malondialdehyde, MDA), and up-regulated levels of apoptotic cells (caspase-3, p53 and tunnel) in myocardial tissue. Treatment of QSYQ improved cardiac remodeling through counter-acting those events. The improvement of QSYQ was accompanied with a restoration of NADPH oxidase 4 (NOX4) and NADPH oxidase 2 (NOX2) pathways in different patterns. Administration of QSYQ could attenuate LAD-induced HF, and AngII-NOX2-ROS-MMPs pathway seemed to be the critical potential targets for QSYQ to reduce the remodeling. Moreover, NOX4 was another key targets to inhibit the p53 and Caspase3, thus to reduce the hypertrophy and apoptosis, and eventually provide a synergetic cardiac protective effect.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Ethan J Rowin ◽  
Barry J Maron ◽  
Iacopo Olivotto ◽  
Susan A Casey ◽  
Anna Arretini ◽  
...  

Background: One-third of HCM patients without left ventricular outflow tract obstruction under resting conditions have the propensity to develop an outflow gradient with physiologic exercise. However, the natural history and management implications of exercise-induced (i.e., provocable) obstruction is unresolved. Methods: We prospectively studied 533 consecutive HCM patients without outflow obstruction at rest (<30mmHg) who underwent a symptom limiting stress (exercise) echocardiogram to assess development of outflow obstruction following physiologic provocation and followed for 6.5 ± 2.0 years. Of the 533 patients, obstruction ≥ 30 mmHg was present following exercise in 262 patients (49%; provocable obstruction), and was absent both at rest and with exercise in 271 (51%; nonobstructive). Results: Over the follow-up period, 43 out of 220 (20%) HCM patients with provocable obstruction and baseline NYHA class I/II symptoms developed progressive limiting heart failure symptoms to class III/IV, compared to 24 of 249 (10%) nonobstructive patients. Rate of heart failure progression was significantly greater in patients with provocable obstruction vs. nonobstructive patients (3.1%/year vs. 1.5%/year; RR=2.0, 95% CI of 1.3-3.2; p=0.003). However, the vast majority of patients with provocable obstruction who developed advanced heart failure symptoms achieved substantial improvement in symptoms to class I / II following relief of obstruction with invasive septal reduction therapy (n=30/32; 94%). In comparison, the majority of nonobstructive patients who developed advanced heart failure remained in class III/IV (16/24;67%), including 10 (42%) currently listed for heart transplant. Conclusions: Stress (exercise) echocardiogram identifies physiological provocable outflow tract obstruction in HCM, and is a predictor of future risk for progressive heart failure (3.1%/year), in patients who become candidates for invasive septal reduction therapy. Therefore, exercise echocardiography should be considered in all HCM patients without obstruction under resting conditions.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Dongmei Liu ◽  
Lie Gao ◽  
Kurtis G Cornish ◽  
Irving H Zucker

In a previous study, we showed that Ang II type I receptor (AT1R) expression increased in the rostral ventrolateral medulla (RVLM) of chronic heart failure (CHF) rabbits and in normal rabbits infused with intracerebroventricular (ICV) Angiotensin II (AngII). The present study investigated if oxidative stress plays a role in Ang II induced AT1R upregulation and its relationship to the transcription factor activator protein 1 (AP1) in CHF rabbits and in the CATHa neuronal cell line. In neuronal cell cultures, Ang II significantly increased AT1R mRNA by 153 ± 22%, P <0.01; c-Jun mRNA by 90 ± 10%, P < 0.01; NADPH oxidase activity by 126 ± 43%, P < 0.01 versus untreated cells; Tempol, Apocynin and the AP 1 inhibitor Tanshinone II reversed the increased AT1R, c-Jun expression and NADPH oxidase activity induced by AngII. We examined the effect of ICV Tempol on expression of these proteins in the RVLM of CHF rabbits. Compared to untreated CHF rabbits Tempol significantly decreased AT1R protein expression (0.88±0.16 vs. 1.6±0.29, P <0.05), phosphorylated Jnk protein (0.10±0.02 vs. 0.31±0.10, P <0.05), and phosphorylated c-Jun (0.02±0.001 vs. 0.14±0.05, P <0.05). These data suggest that Ang II induces AT1R upregulation at the transcriptional level by activation of oxidative stress and AP1 in both cultured cells and in intact brain. Antioxidant agents may be beneficial in CHF by decreasing AT1R expression through the Jnk and AP1 pathway.


2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Merry W. Ma ◽  
Jing Wang ◽  
Krishnan M. Dhandapani ◽  
Darrell W. Brann

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. After the initial primary mechanical injury, a complex secondary injury cascade involving oxidative stress and neuroinflammation follows, which may exacerbate the injury and complicate the healing process. NADPH oxidase 2 (NOX2) is a major contributor to oxidative stress in TBI pathology, and inhibition of NOX2 is neuroprotective. The NLRP3 inflammasome can become activated in response to oxidative stress, but little is known about the role of NOX2 in regulating NLRP3 inflammasome activation following TBI. In this study, we utilized NOX2 knockout mice to study the role of NOX2 in mediating NLRP3 inflammasome expression and activation following a controlled cortical impact. Expression of NLRP3 inflammasome components NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC), as well as its downstream products cleaved caspase-1 and interleukin-1β (IL-1β), was robustly increased in the injured cerebral cortex following TBI. Deletion of NOX2 attenuated the expression, assembly, and activity of the NLRP3 inflammasome via a mechanism that was associated with TXNIP, a sensor of oxidative stress. The results support the notion that NOX2-dependent inflammasome activation contributes to TBI pathology.


2018 ◽  
Vol 28 (7) ◽  
pp. 429-434 ◽  
Author(s):  
Eduardo Fuentes ◽  
Jonathan M. Gibbins ◽  
Lisa M. Holbrook ◽  
Iván Palomo

2008 ◽  
Vol 86 (11) ◽  
pp. 752-760 ◽  
Author(s):  
Adil El Midaoui ◽  
Mahmoud Ali Ismael ◽  
Huogen Lu ◽  
I. George Fantus ◽  
Jacques de Champlain ◽  
...  

Beneficial effects of an antioxidant (N-acetyl-l-cysteine, NAC) and an angiotensin I-converting enzyme (ACE) inhibitor (ramipril) were assessed in a rat model of insulin resistance induced by 10% glucose feeding for 20 weeks. Treatments with NAC (2 g/kg per day) and ramipril (1 mg/kg per day) were initiated at 16 weeks in the drinking fluid. Systolic blood pressure, plasma levels of insulin and glucose, and insulin resistance were significantly higher in rats treated with glucose for 20 weeks. This was associated with a higher production of superoxide anion and NADPH oxidase activity in aorta and liver and with a marked reduction in protein expression of skeletal muscle insulin receptor substrate-1 (IRS-1) in the gastrocnemius muscle. NAC prevented all these alterations. Although ramipril also reversed high blood pressure, it had a lesser effect on insulin resistance (including IRS-1) and blocked superoxide anion production only in aorta. Ramipril, in contrast to NAC, did not reduce NADPH oxidase activity in aorta and liver or plasma levels of 4-hydroxynonenal and malondialdehyde. Results suggest that the inhibition of the oxidative stress in hypertensive and insulin-resistant states contributes to the therapeutic effects of NAC and ramipril. Whereas NAC exerts effective antioxidant activity in multiple tissues, ramipril appears to preferentially target the vasculature.


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