Abstract 146: Disruption of Nox2 and TNFRp55/p75 Eliminates Anisomycin-Induced Preconditioning Effect in the Heart

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Ting C Zhao ◽  
Ling Zhang ◽  
Tai-Liang Guo
Keyword(s):  
Infarct Size ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Kinase Assay ◽  
Protective Effects ◽  
Triphenyltetrazolium Chloride ◽  
Transient Activation ◽  
Novel Approach ◽  
Tnf Α ◽  
A Subunit

Background: Transient activation of p38 through anisomycin is demonstrated to precondition the heart against myocardial injury. However, it remains unknown whether specific TNF-α receptor (TNFR) p55/p75 and Nox2, a subunit of NADPH-oxidase are involved in this event. Objective: We sought to investigate whether the genetic disruption of TNFRp55/p75 and Nox2 eliminates cardioprotection elicited by anisomycin and whether p38-dependent activation of Nox2 stimulates TNFR to ultimately achieve protective effects. Methods: Adult wild type and p55/p75 -/- and Nox2 -/- mice received intraperitoneal injections of anisomycin (0.1mg/kg), a potent activator of p38. The hearts were subjected to 30 min myocardial ischemia /30 min reperfusion in the Langendorff perused heart after twenty four hours. Left ventricular function was measured and infarct size was determined by triphenyltetrazolium chloride. Myocardial TNF-α protein, Nox2 and superoxides releases were detected. Gel kinase assay was employed to detect the effect of p38 on Nox2 phosphorylation. Results: Activation of p38 through anisomycin produces marked improvements in the recovery of left ventricular end diastolic pressure, rate pressure products, and the reduction of myocardial infarction, which were completely abrogated by disruption of Nox2 and TNFR p55/p75. Genetic disruption of Nox2 and TNFR p55/p75 abolished the effect of anisomycin-induced reduction of infarct size. Ansiomycin induced the production of TNFα, which was abrogated in Nox2 -/- mice. Notably, activation of p38 resulted in the phosphorylation of Nox2. Conclusion: Taken together, these results indicate that stimulation of the Nox2 and TNFR p55/p75 pathway is a novel approach to anisomycin-induced cardioprotection.

scholarly journals Disruption of Nox2 and TNFRp55/p75 eliminates cardioprotection induced by anisomycin

2012 ◽  
Vol 303 (10) ◽  
pp. H1263-H1272 ◽  
Author(s):  
Ting C. Zhao ◽  
Ling Zhang ◽  
Jun T. Liu ◽  
Tai L. Guo
Keyword(s):  
Infarct Size ◽  
Myocardial Injury ◽  
Left Ventricular ◽  
Kinase Assay ◽  
Protective Effects ◽  
Perfused Heart ◽  
Transient Activation ◽  
Novel Approach ◽  
Tnf Α ◽  
A Subunit

Transient activation of p38 through anisomycin is demonstrated to precondition the heart against myocardial injury. However, it remains unknown whether specific TNF-α receptor (TNFR) p55/p75 and Nox2, a subunit of NADPH oxidase, are involved in this event. We sought to investigate whether the genetic disruption of TNFRp55/p75 and Nox2 eliminated cardioprotection elicited by anisomycin and whether p38-dependent activation of Nox2 stimulated TNFR to ultimately achieve protective effects. Adult wild-type and TNFR p55/p75−/−and Nox2−/−mice received intraperitoneal injections of anisomycin (0.1 mg/kg), a potent activator of p38. The hearts were subjected to 30 min myocardial ischemia/30 min reperfusion in the Langendorff perfused heart after 24 h. Left ventricular function was measured, and infarct size was determined. Myocardial TNF-α protein, Nox2, and superoxides releases were detected. Gel kinase assay was employed to detect the effect of p38 on Nox2 phosphorylation. Activation of p38 through anisomycin produces marked improvements in left ventricular functional recovery, and the reduction of myocardial infarction, which were abrogated by disruption of Nox2 and TNFR p55/p75. Disruption of Nox2 and TNFR p55/p75 abolished the effect of anisomycin-induced reduction of infarct size. Anisomycin induced the production of TNF-α, which was abrogated in Nox2−/−mice and by treatment with SB203580, but not by disruption of p55/p75. Anisomycin treatment resulted in an increase in Nox2 protein and the phosphorylation of Nox2, which was blocked by inhibition of p38. Taken together, these results indicate that stimulation of the Nox2 and TNFR p55/p75 pathway is a novel approach to anisomycin-induced cardioprotection.

KATPchannels mediate the beneficial effects of chronic ethanol ingestion

2000 ◽  
Vol 279 (5) ◽  
pp. H2574-H2579 ◽  
Author(s):  
Paul S. Pagel ◽  
Wolfgang G. Toller ◽  
Eric R. Gross ◽  
Meir Gare ◽  
Judy R. Kersten ◽  
...  
Keyword(s):  
Infarct Size ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Left Ventricular ◽  
Ethanol Ingestion ◽  
Protective Effects ◽  
Area At Risk ◽  
Triphenyltetrazolium Chloride ◽  
Beneficial Effects ◽  
Dry Food

Chronic ingestion of low doses of ethanol protects the myocardium from ischemic injury by activating adenosine receptors and protein kinase C. We tested the hypothesis that ATP-dependent potassium (KATP) channels mediate these beneficial effects. Dogs were fed with ethanol (1.5 g/kg) or water mixed with dry food twice per day for 12 wk. After they were acutely instrumented for measurement of hemodynamics, dogs received saline (vehicle) or glyburide (0.1 mg/kg iv) and were subjected to 60 min of coronary artery occlusion followed by 3 h of reperfusion. Infarct size (through triphenyltetrazolium chloride staining) was significantly ( P < 0.05) reduced to 14 ± 1% of the left ventricular area at risk in ethanol-pretreated dogs compared with controls (25 ± 2%). Glyburide alone did not affect infarct size (25 ± 3%) but abolished the protective effects of ethanol pretreatment (28 ± 3%). No differences in hemodynamics or coronary collateral blood flow (through radioactive microspheres) were observed among groups. The results indicate that KATPchannels mediate the protective effects of chronic consumption of ethanol.

scholarly journals Melatonin combination with perindopril alleviated doxorubicin cardiac toxicity in L-NAME hypertensive rats: comparative study with perindopril

2019 ◽  
Author(s):  
Takwa Mohammed Abdul Salam ◽  
Amany Helmy Hasanin ◽  
Wesam El-Bakly ◽  
Mona Hussein Raafat ◽  
Nesreen Omar ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Cardiac Toxicity ◽  
Diastolic Pressure ◽  
Transforming Growth Factor Β ◽  
Left Ventricular ◽  
Protective Effects ◽  
Hypertensive Rats ◽  
Tnf Α ◽  
Doxorubicin Cardiotoxicity ◽  
Percentage Area

Introduction: Doxorubicin is a highly effective anticancer agent with serious cardiotoxic effects. Hypertension is considered as a major risk factor for doxorubicin cardiotoxicity. It should be noted that about one-third of cancer patients have hypertension, and melatonin can have cardio-protective effects. The present study aimed to further investigate the possible beneficial effects of melatonin co-administration to perindopril against doxorubicin cardiotoxicity in hypertensive rats. Method: Rats were randomly assigned to naïve group and L-NAME group, which was further subdivided into untreated, doxorubicin, doxorubicin/perindopril, doxorubicin/melatonin and doxorubicin/perindopril/melatonin subgroups. Cardiac functions, CK-MB, malondialdehyde, superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), and cardiac percentage area of collagen fibers were evaluated. Results: Combining melatonin with perindopril to doxorubicin produced significant decreases in left ventricular end diastolic pressure, malondialdehyde, TNF-α, and TGF-β. It resulted in significant increases in left ventricular dP/dtmax and SOD, in addition to apparent improvement in cardiac histopathology with a significant decrease in percentage area of collagen deposition compared to perindopril alone. Conclusion: Co-administration of melatonin to perindopril in hypertensive rats who received doxorubicin alleviated doxorubicin cardiac toxicity more than using perindopril alone. These effects could be explained by the reported antihypertensive, anti-inflammatory, anti-oxidant, and anti-fibrotic effects of melatonin.

scholarly journals Importance of timing of magnesium administration in the isolated ischemic-reperfused rat heart: role of K-ATP channels

2008 ◽  
pp. 839-846
Author(s):  
M Bazargan ◽  
M Faghihi ◽  
M Chitsaz
Keyword(s):  
Cardiac Function ◽  
Infarct Size ◽  
Rat Heart ◽  
Katp Channels ◽  
Left Ventricular ◽  
Cardiovascular Disorders ◽  
Protective Effects ◽  
Triphenyltetrazolium Chloride ◽  
Rat Hearts

There is a growing interest for the beneficial effect of magnesium (Mg) in cardiovascular disorders. A number of cardiovascular disorders including myocardial infarction, arrhythmias and congestive heart failure have been associated with low extracellular or intracellular concentrations of Mg. The efficiency of the preconditioning effect of Mg on cardiac function and infarct size in the globally ischemic-reperfused isolated rat heart was studied together with the role of ATP-sensitive potassium (KATP) channels in protection induced by Mg. Rat hearts were Langendorff perfused, subjected to 30 min of global ischemia and 90 min of reperfusion, including treatment groups which focused on different times of Mg (8 mmol/l) use. Infarct size was measured by triphenyltetrazolium chloride (TTC) method. The left ventricular function was assessed by left ventricular developed pressure (LVDP), heart rate (HR) and coronary flow (CF). The administration of Mg before ischemia had an anti-infarct effect in rat hearts and improved cardiac function. The protective effects of magnesium was abolished by the blocking of KATP channels and suggests that K-ATP channel has an important role in the heart protection effect of Mg as a preconditioning agent.

scholarly journals Melatonin combination with perindopril alleviated doxorubicin cardiac toxicity in L-NAME hypertensive rats: comparative study with perindopril

2019 ◽  
Author(s):  
Takwa Mohammed Abdul Salam ◽  
Amany Helmy Hasanin ◽  
Wesam El-Bakly ◽  
Mona Hussein Raafat ◽  
Nesreen Omar ◽  
...  
Keyword(s):  
Transforming Growth Factor ◽  
Cardiac Toxicity ◽  
Diastolic Pressure ◽  
Transforming Growth Factor Β ◽  
Left Ventricular ◽  
Protective Effects ◽  
Hypertensive Rats ◽  
Tnf Α ◽  
Doxorubicin Cardiotoxicity ◽  
Percentage Area

Introduction: Doxorubicin is a highly effective anticancer agent with serious cardiotoxic effects. Hypertension is considered as a major risk factor for doxorubicin cardiotoxicity. It should be noted that about one-third of cancer patients have hypertension, and melatonin can have cardio-protective effects. The present study aimed to further investigate the possible beneficial effects of melatonin co-administration to perindopril against doxorubicin cardiotoxicity in hypertensive rats. Method: Rats were randomly assigned to naïve group and L-NAME group, which was further subdivided into untreated, doxorubicin, doxorubicin/perindopril, doxorubicin/melatonin and doxorubicin/perindopril/melatonin subgroups. Cardiac functions, CK-MB, malondialdehyde, superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), and cardiac percentage area of collagen fibers were evaluated. Results: Combining melatonin with perindopril to doxorubicin produced significant decreases in left ventricular end diastolic pressure, malondialdehyde, TNF-α, and TGF-β. It resulted in significant increases in left ventricular dP/dtmax and SOD, in addition to apparent improvement in cardiac histopathology with a significant decrease in percentage area of collagen deposition compared to perindopril alone. Conclusion: Co-administration of melatonin to perindopril in hypertensive rats who received doxorubicin alleviated doxorubicin cardiac toxicity more than using perindopril alone. These effects could be explained by the reported antihypertensive, anti-inflammatory, anti-oxidant, and anti-fibrotic effects of melatonin.

scholarly journals Cardioprotective effects of Ginsenoside compound-Mc1 and Dendrobium Nobile Lindl against myocardial infarction in an aged rat model: Involvement of TLR4/NF-κB signaling pathway

2021 ◽  
Vol 19 ◽  
pp. 205873922110005
Author(s):  
Yongle Sun ◽  
Jing Geng ◽  
Deyu Wang
Keyword(s):  
Myocardial Infarction ◽  
Combination Therapy ◽  
Infarct Size ◽  
Signaling Pathway ◽  
Left Ventricular ◽  
Male Rats ◽  
Dendrobium Nobile ◽  
Tnf Α ◽  
Cardioprotective Effects ◽  
Dendrobium Nobile Lindl

Aging is the crucial co-morbidity that prevents the full cardioprotection against myocardial ischemia/reperfusion (I/R) injury. Combination therapy as a promising strategy may overcome this clinical problem. This study aimed to investigate the cardioprotective effects of Ginsenoside compound-Mc1 (GMc1) and Dendrobium Nobile Lindl (DNL) in myocardial I/R injury and explore the involvement of the TLR4/NF-κB signaling pathway in aged rats. In vivo I/R injury and myocardial infarction was established by temporary coronary ligation in 22–24 months’ old Sprague Dawley male rats. GMc1 (10 mg/kg) and DNL (80 mg/kg) were administered intraperitoneally for 4 weeks and orally for 14 days, respectively, before I/R injury. Infarct size was measured through triphenyl-tetrazolium-chloride staining. ELISA assay was conducted to quantify the levels of cardiotroponin, and myocardial content of TNF-α and glutathione. Western blotting was employed to detect the expression of TLR4/MyD88/NF-κB proteins. GMc1 and DNL significantly reduced the infarct size to a similar extent ( p < 0.05) but their combined effect was greater than individual ones ( p < 0.01). Combination therapy significantly restored the left ventricular end-diastolic and developed pressures at the end of reperfusion as compared with the untreated group ( p < 0.01). Although the GMc1 and DNL reduced the levels of inflammatory cytokine TNF-α and increased the contents of antioxidant glutathione significantly, their individual effects on the reduction of protein expression of TLR4/MyD88/NF-κB pathway were not consistent. However, their combination could significantly reduce all parameters of this inflammatory pathway as compared to untreated I/R rats ( p < 0.001). Therefore, the combined treatment with GMc1 and DNL increased the potency of each intervention in protecting the aged hearts against I/R injury. Reduction in the activity of the TLR4/MyD88/NF-κB signaling pathway and subsequent modulation of the activity of inflammatory cytokines and endogenous antioxidants play an important role in this cardioprotection.

DNA enzyme targeting TNF-α mRNA improves hemodynamic performance in rats with postinfarction heart failure

2001 ◽  
Vol 281 (5) ◽  
pp. H2211-H2217 ◽  
Author(s):  
Per Ole Iversen ◽  
Gunnar Nicolaysen ◽  
Mouldy Sioud
Keyword(s):  
Heart Failure ◽  
Therapeutic Potential ◽  
Diastolic Pressure ◽  
Substantial Reduction ◽  
Left Ventricular ◽  
Lung Weight ◽  
Cleavage Activity ◽  
Arterial Blood ◽  
Modified Dna ◽  
Tnf Α

Tumor necrosis factor-α (TNF-α) probably affects the pathogenesis of heart failure. Here we have investigated the therapeutic potential of a nuclease-resistant DNA enzyme that specifically cleaves TNF-α mRNA. A phosphorothioate-modified DNA enzyme was designed to retain similar cleavage activity as its unmodified version, and that inhibited the expression of TNF-α in vitro. To test its efficacy in vivo, postinfarction congestive heart failure was induced in anesthetized rats by ligation of the left coronary artery. A 4-wk treatment with the DNA enzyme induced a substantial reduction in left ventricular end-diastolic pressure and lung weight concomitant with an increase in arterial blood pressure and myocardial blood flow compared with controls. The concentration of TNF-α in coronary sinus blood was markedly lowered on treatment, and myocardial TNF-α mRNA was substantially reduced. Recovery studies showed that the DNA enzyme cleavage activity was present within the myocardium throughout the observation period and had no apparent toxic effects. Our findings indicate that DNA enzyme-based therapy may hold promise in the treatment of this debilitating disease.

scholarly journals Possible mechanism of the cardio-renal protective effects of AVE-0991, a non-peptide Mas-receptor agonist, in diabetic rats

2012 ◽  
Vol 13 (3) ◽  
pp. 334-340 ◽  
Author(s):  
Kulwinder Singh ◽  
Kuldeepak Sharma ◽  
Manjeet Singh ◽  
PL Sharma
Keyword(s):  
Blood Pressure ◽  
Receptor Agonist ◽  
Diastolic Pressure ◽  
Left Ventricular Pressure ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Ventricular Pressure ◽  
Protective Effects ◽  
Mas Receptor ◽  
Arterial Blood

Hypothesis: This study was designed to investigate the cardio-renal protective effect of AVE-0991, a non-peptide Mas-receptor agonist, and A-779, a Mas-receptor antagonist, in diabetic rats. Materials and methods: Wistar rats treated with streptozotocin (50 mg/kg, i.p., once), developed diabetes mellitus after 1 week. After 8 weeks, myocardial functions were assessed by measuring left ventricular developed pressure (LVDP), rate of left ventricular pressure development (d p/d tmax), rate of left ventricular pressure decay (d p/d tmin) and left ventricular end diastolic pressure (LVEDP) on an isolated Langendorff’s heart preparation. Further, mean arterial blood pressure (MABP) was measured by using the tail-cuff method. Assessment of renal functions and lipid profile was carried out using a spectrophotometer. Results: The administration of streptozotocin to rats produced persistent hyperglycaemia, dyslipidaemia and hypertension which consequently produced cardiac and renal dysfunction in 8 weeks. AVE0991 treatment produced cardio-renal protective effects, as evidenced by a significant increase in LVDP, d p/d tmax, d p/d tmin and a significant decrease in LVEDP, BUN, and protein urea. Further, AVE-0991 treatment for the first time has been shown to reduce dyslipidaemia and produced antihyperglycaemic activity in streptozotocin-treated rats. However, MABP and creatinine clearance remained unaffected with AVE-0991 treatment. Conclusions: AVE-0991 produced cardio-renal protection possibly by improving glucose and lipid metabolism in diabetic rats, independent of its blood pressure lowering action.

Isoflurane Mimics Ischemic Preconditioning via Activation of KATPChannels 

1997 ◽  
Vol 87 (2) ◽  
pp. 361-370 ◽  
Author(s):  
Judy R. Kersten ◽  
Todd J. Schmeling ◽  
Paul S. Pagel ◽  
Garrett J. Gross ◽  
David C. Warltier
Keyword(s):  
Infarct Size ◽  
Ischemic Preconditioning ◽  
Myocardial Infarct ◽  
Myocardial Infarct Size ◽  
Protective Effects ◽  
Hemodynamic Effects ◽  
Area At Risk ◽  
Triphenyltetrazolium Chloride ◽  
Anesthetized Dogs

Background The authors tested the hypothesis that isoflurane directly preconditions myocardium against infarction via activation of K(ATP) channels and that the protection afforded by isoflurane is associated with an acute memory phase similar to that of ischemic preconditioning. Methods Barbiturate-anesthetized dogs (n = 71) were instrumented for measurement of systemic hemodynamics. Myocardial infarct size was assessed by triphenyltetrazolium chloride staining. All dogs were subjected to a single prolonged (60 min) left anterior descending coronary artery (LAD) occlusion followed by 3 h of reperfusion. Ischemic preconditioning was produced by four 5-min LAD occlusions interspersed with 5-min periods of reperfusion before the prolonged LAD occlusion and reperfusion. The actions of isoflurane to decrease infarct size were examined in dogs receiving 1 minimum alveolar concentration (MAC) isoflurane that was discontinued 5 min before prolonged LAD occlusion. The interaction between isoflurane and ischemic preconditioning on infarct size was evaluated in dogs receiving isoflurane before and during preconditioning LAD occlusions and reperfusions. To test whether the cardioprotection produced by isoflurane can mimic the acute memory of ischemic preconditioning, isoflurane was discontinued 30 min before prolonged LAD occlusion and reperfusion. The mechanism of isoflurane-induced cardioprotection was evaluated in two final groups of dogs pretreated with glyburide in the presence or absence of isoflurane. Results Myocardial infarct size was 25.3 +/- 2.9% of the area at risk during control conditions. Isoflurane and ischemic preconditioning produced significant (P &lt; 0.05) and equivalent reductions in infarct size (ischemic preconditioning alone, 9.6 +/- 2.0; isoflurane alone, 11.8 +/- 2.7; isoflurane and ischemic preconditioning, 5.1 +/- 1.9%). Isoflurane-induced reduction of infarct size also persisted 30 min after discontinuation of the anesthetic (13.9 +/- 1.5%), independent of hemodynamic effects during LAD occlusion. Glyburide alone had no effect on infarct size (28.3 +/- 3.9%), but it abolished the protective effects of isoflurane (27.1 +/- 4.6%). Conclusions Isoflurane directly preconditions myocardium against infarction via activation of K(ATP) channels in the absence of hemodynamic effects and exhibits acute memory of preconditioning in vivo.

Role of endogenous testosterone in myocardial proinflammatory and proapoptotic signaling after acute ischemia-reperfusion

2005 ◽  
Vol 288 (1) ◽  
pp. H221-H226 ◽  
Author(s):  
Meijing Wang ◽  
Ben M. Tsai ◽  
Ajay Kher ◽  
Lauren B. Baker ◽  
G. Mathenge Wairiuko ◽  
...  
Keyword(s):  
P38 Mapk ◽  
Functional Recovery ◽  
Caspase 3 ◽  
Diastolic Pressure ◽  
Contractile Function ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Acute Ischemia ◽  
Caspase 1 ◽  
Tnf Α

Myocardial ischemia is the leading cause of death in both men and women; however, very little information exists regarding the effect of testosterone on the response of myocardium to acute ischemic injury. We hypothesized that testosterone may exert deleterious effects on myocardial inflammatory cytokine production, p38 MAPK activation, apoptotic signaling, and myocardial functional recovery after acute ischemia-reperfusion (I/R). To study this, isolated, perfused rat hearts (Langendorff) from adult males, castrated males, and males treated with a testosterone receptor blocker (flutamide) were subjected to 25 min of ischemia followed by 40 min of reperfusion. Myocardial contractile function (left ventricular developed pressure, left ventricular end-diastolic pressure, positive and negative first derivative of pressure) was continuously recorded. After reperfusion, hearts were analyzed for expression of tissue TNF-α, IL-1β, and IL-6 (ELISA) and activation of p38 MAPK, caspase-1, caspase-3, caspase-11, and Bcl-2 (Western blot). All indices of postischemic myocardial functional recovery were significantly higher in castrated males or flutamide-treated males compared with untreated males. After I/R, castrated male and flutamide-treated male hearts had decreased TNF-α, IL-1β, and IL-6; decreased activated p38 MAPK; decreased caspase-1, caspase-3, and caspase-11; and increased Bcl-2 expression compared with untreated males. These results show that blocking the testosterone receptor (flutamide) or depleting testosterone (castration) in normal males improves myocardial function after I/R. These effects may be attributed to the proinflammatory and/or the proapoptotic properties of endogenous testosterone. Further understanding may allow therapeutic manipulation of sex hormone signaling mechanisms in the treatment of acute I/R.

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