Abstract 216: Tat Delivery of a Pten Peptide Inhibitor Has Direct Cardioprotective Effects and Improves Outcomes in Rodent Models of Cardiac Arrest

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_4) ◽  
Author(s):  
Xiangdong Zhu ◽  
Jing Li ◽  
Huashan Wang ◽  
Filip Gasior ◽  
Chunpei Lee ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Mouse Model ◽  
Pyruvate Dehydrogenase ◽  
Contractile Function ◽  
Heart Function ◽  
Isolated Heart ◽  
Lactate Production ◽  
Polyol Pathway ◽  
Protective Effects ◽  
Cardiac Arrest Survival

Introduction: We have recently shown that pharmacologic inhibition of PTEN significantly increases cardiac arrest survival in a mouse model, however, this protection required pretreatment 30 min prior to the arrest. To improve the onset of PTEN inhibition during cardiac arrest treatment, we have designed a TAT fused cell-permeable peptide (TAT-PTEN9c) for rapid tissue delivery and protection. Hypothesis: We hypothesized that TAT-PTEN9c interferes with the endogenous PTEN binding to its regulatory proteins, resulting in reduced PTEN activity, improved mouse survival and cardiac functional recovery. The improved survival is in part due to enhanced glycolysis and reduced shunting to polyol pathway and osmotic injury in heart and brain. Methods: TAT-PTEN9c (7.5 mg/kg) was given intravenously after CA in mouse to determine protective effects of the treatment on survival and heart function. Western blot was used to determine the efficacy of TAT-PTEN9c for enhancing Akt and PDH E1α activity. The effect of TAT-PTEN9c on sorbitol accumulation in tissues was measured by spectrophotometer using NAD as substrate. Direct effect of TAT-PTEN9c treatment on cardiac function were also measured in Langendorff model of isolated rat heart. Results: In the mouse model of cardiac arrest, survival was significantly increased in the TAT-PTEN9c treated group compared to saline controls at 4 h after CPR. The treated mice had increased Akt phosphorylation and pyruvate dehydrogenase dephosphorylation at R30 min in heart tissues with significantly decreased sorbitol content and reduced release of taurine and glutamate into blood, suggesting improved metabolic recovery and glucose utilization. For the isolated heart model, RPP was reduced by 25% for non-treatment groups following arrest. With TAT-PTEN9c treatment, cardiac contractile function was completely recovered. TAT-PTEN9c significantly increased lactate production at 20 min of reperfusion, indicating increased glycolysis. Conclusion: TAT-PTEN9c enhances Akt and pyruvate dehydrogenase activity and decrease glucose shunting to the polyol pathway in critical organs, preventing osmotic injury and early cardiovascular collapse and death.

Abstract 276: TAT-PTEN9c Targets Heart Directly to Improve Survival From Cardiac Arrest

Circulation ◽  
2019 ◽  
Vol 140 (Suppl_2) ◽  
Author(s):  
Xiangdong Zhu ◽  
Filip Gasior ◽  
Jing Li ◽  
Huashan Wang ◽  
Zhiyi Zhu ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Direct Effect ◽  
Functional Recovery ◽  
Rat Heart ◽  
Enhanced Recovery ◽  
Contractile Function ◽  
Heart Function ◽  
Isolated Heart ◽  
Protective Effects ◽  
Akt Activation

Introduction: It is well established that hypothermia enhances cardiac arrest (CA) survival due, in part, to a mechanism of enhanced Akt activation. In this study we investigate whether the biosynthetic PTEN inhibitor (TAT-PTEN9c) provides therapeutic protection on survival due to direct effects on heart. Hypothesis: We hypothesized that TAT-PTEN9c interferes with endogenous PTEN binding at its cell membrane adaptor and leads to enhanced Akt activation, mouse survival and cardiac functional recovery. The improved CA survival is due in part to the improved contractile functional recovery of heart by TAT-PTEN9c. We also tested if the treatment targets the heart directly to enhanced recovery in isolated perfused rat heart after a period of global arrest. Methods: TAT-PTEN9c (7.5 mg/kg) was given intravenously (IV) after CA in mouse to determine protective effects of the treatment on survival and heart function. Western blot was used to determine the efficacy of TAT-PTEN9c for Akt activation. In the isolated rat heart, direct effect of treatment (1-10 μm) on cardiac function (HR, LVDP, RPP) were measured for 20 min following 20 min global ischemia. Results: In the mouse model of cardiac arrest, survival was significantly increased in the TAT-PTEN9c treated group compared to saline controls at 4 h (10/15, 67% vs. 6/15, 40%, P < 0.05) after CPR. TAT-PTEN9c improved MAP at both R30 min and R2h. The treated mice had increased Akt phosphorylation at R15 min in both heart and brain tissues with significantly decreased sorbitol content and reduced release of taurine and glutamate into blood, suggesting improved metabolic recovery and glucose utilization. For the isolated heart model, RPP was reduced by 25% for both TAT vehicle and non-treatment groups following arrest. With TAT-PTEN9c treatment, cardiac contractile function was completely recovered (pre-arrest RPP 29.1k+/- 4.8; post-arrest 28.0K +/- 5.0). Conclusion: TAT-PTEN9c enhances Akt activation and decrease glucose shunting to the polyol pathway in critical organs, preventing osmotic injury and early cardiovascular collapse and death. The improved survival by this treatment is in part due to its direct effect on heart functional recovery.

Abstract 323: A Peptide Inhibitor of PTEN Improves Mouse Survival After Cardiac Arrest

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Xiangdong Zhu ◽  
Jing Li ◽  
Huashan Wang ◽  
Chunpei Lee ◽  
Zhiyi Zhu ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Mouse Model ◽  
Glucose Utilization ◽  
Polyol Pathway ◽  
Treated Group ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Akt Phosphorylation ◽  
Akt Activation

Introduction: Prior works from our laboratory found that cooling protection after cardiac arrest is mediated by enhanced Akt activation and in cardiomyocyte the cooling protection can be reproduced using PTEN chemical inhibitor. The current study extend these works by designing a cell-permeable peptide, TAT-PTEN9c, which is more specific for PTEN. Hypothesis: We hypothesized that TAT-PTEN9c interferes with endogenous PTEN binding to cell membrane adaptor resulting in increased Akt activation, enhanced glucose utilization and improved mouse survival after cardiac arrest. Methods: Mouse cardiomyocytes were isolated from 1-3 day old mouse pups. Western blot was used to determine the efficacy of TAT-PTEN9c for Akt activation. The effect of TAT-PTEN9c on mouse survival after cardiac arrest was determined in a mouse model. TAT-PTEN9c (7.5 mg/kg) was given intravenously (IV) after CPR. As a measure of impaired glucose utilization, sorbitol content in heart and brain was determined by a fluorescence assay of NADH formation using sorbitol dehydrogenase and NAD + . Results: TAT-PTEN9c peptide enhanced Akt activation in mouse cardiomyocytes in a concentration-dependent manner. Akt phosphorylation was observed at 1 μM and further increased with 10 μM TAT-PTEN9c. TAT-PTEN9c blocked the binding of endogenous PTEN to MAGI2 in a co-immunoprecipitation assay, while TAT-PTEN3a control had no inhibitory effect. In a mouse model of cardiac arrest, survival was significantly increased in the TAT-PTEN9c treated group compared to saline controls at 4 h (10/15, 67% vs. 6/15, 40%, P < 0.05) after CPR. TAT-PTEN9c improved MAP at both R30 min and R2h. The treated mice had increased Akt phosphorylation at R15 min in both heart and brain tissues with significantly decreased sorbitol content and reduced release of taurine and glutamate into blood, suggesting improved metabolic recovery and glucose utilization. Conclusion: TAT-PTEN9c can be used after CPR in a mouse SCA model to rapidly enhance Akt activation and decrease glucose shunting to the polyol pathway in critical organs, preventing osmotic injury and early cardiovascular collapse and death.

Abstract 12508: Nicotinamide Restores Tissue NAD + and Improves Mouse Survival After Cardiac Arrest

Circulation ◽  
2021 ◽  
Vol 144 (Suppl_2) ◽  
Author(s):  
Xiangdong Zhu ◽  
Jing Li ◽  
Filip Gasior ◽  
Huashan Wang ◽  
Shaoxia Lin ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Cardiac Function ◽  
Rat Heart ◽  
Contractile Function ◽  
Polyol Pathway ◽  
Isolated Rat Heart ◽  
Saline Control ◽  
Cardiac Contractile Function ◽  
Buffer Control ◽  
Contractile Recovery

Introduction: Metabolic suppression in the ischemic heart is characterized by NAD + depletion. How nicotinamide (NAM) supplementation affects NAD + repletion and cardiac arrest outcomes is unknown. Hypothesis: We hypothesized that NAM supplementation restores tissue NAD + and promotes glucose oxidation and sorbitol clearance, resulting in improved cardiac function and survival in a mouse model of cardiac arrest. Methods: Adult C57BL6 mice were subjected to an established KCL-induced 8 min cardiac arrest, randomly assigned to receive saline (NS) or 100 mg/kg NAM during cardiopulmonary resuscitation (CPR). Survival, MAP, ETCO 2, and ECG were monitored for 4 h after the return of spontaneous circulation (ROSC). Direct cardiac effects were assessed using a cardiomyocyte stunning model and an isolated rat heart Langendroff model to measure the contraction recovery and cardiac function, respectively. NAD + , lactate and ATP were measured by assay kits and AMPK phosphorylation was measured by Western blot. Results: Cardiomyocyte NAD + content decreased from 4.51 ± 0.03 nMol/g pre-ischemia to 2.69 ± 0.42 nMol/g at the end of ischemia. Treatment with 0.01 mM NAM completely restored the cellular level of NAD + and improved contractile recovery by 10 min reperfusion (58.1 ± 7.3% of baseline contractile velocity vs.18.5 ± 3.7% in control cells). NAM administered immediately after ROSC significantly improved mouse survival, with 10/10 survival at 4 h as compared to 5/10 in the NS group. NAM-treated mice displayed improved NAD + content in hearts obtained at 4 h post-ROSC compared to saline treated hearts (4.5 ± 0.1 nMol/g vs. 2.4 ± 0.1 nMol/g). NAM significantly reduced sorbitol accumulation in heart from saline control of 20.4 ± 2.7 μMol/g to 7.2 ± 1.5 μMol/g at 30 min post-ROSC, indicating less glucose shunting to polyol pathway. Cardiac contractile function was completely recovered with 1 mM NAM treatment in the isolated perfused rat heart. Compared with buffer control, NAM treatment increased heart content of NAD + , lactate, ATP and phosphorylated AMPK. Conclusion: NAM is efficacious for restoring cardiac NAD + and promotes metabolic and contractile recovery, with improved survival of cardiac arrest.

scholarly journals Protective Effects of Dinitrosyl Iron Complexes under Oxidative Stress in the Heart

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Valery I. Kapelko ◽  
Vladimir L. Lakomkin ◽  
Alexander A. Abramov ◽  
Elena V. Lukoshkova ◽  
Nidas A. Undrovinas ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Contractile Function ◽  
Isolated Heart ◽  
Reactive Oxygen Species Generation ◽  
Left Ventricular ◽  
Iron Complex ◽  
Protective Effects ◽  
No Donor ◽  
Dinitrosyl Iron ◽  
Hypoxia Reoxygenation

Background. Nitric oxide can successfully compete with oxygen for sites of electron-transport chain in conditions of myocardial hypoxia. These features may prevent excessive oxidative stress occurring in cardiomyocytes during sudden hypoxia-reoxygenation.Aim. To study the action of the potent stable NO donor dinitrosyl iron complex with glutathione (Oxacom®) on the recovery of myocardial contractile function and Ca2+transients in cardiomyocytes during hypoxia-reoxygenation.Results. The isolated rat hearts were subjected to 30 min hypoxia followed by 30 min reoxygenation. The presence of 30 nM Oxacom in hypoxic perfusate reduced myocardial contracture and improved recovery of left ventricular developed pressure partly due to elimination of cardiac arrhythmias. The same Oxacom concentration limited reactive oxygen species generation in hypoxic cardiomyocytes and increased the viability of isolated cardiomyocytes during hypoxia from 12 to 52% and after reoxygenation from 0 to 40%. Oxacom prevented hypoxia-induced elevation of diastolic Ca2+level and eliminated Ca2+transport alterations manifested by slow Ca2+removal from the sarcoplasm and delay in cardiomyocyte relaxation.Conclusion. The potent stable NO donor preserved cardiomyocyte integrity and improved functional recovery at hypoxia-reoxygenation both in the isolated heart and in cardiomyocytes mainly due to preservation of Ca2+transport. Oxacom demonstrates potential for cardioprotection during hypoxia-reoxygenation.

TAT Delivery of a PTEN Peptide inhibitor Has Direct Cardioprotective Effects and Improves Outcomes in Rodent Models of Cardiac Arrest

2021 ◽  
Author(s):  
Xiangdong Zhu ◽  
Jing Li ◽  
Huashan Wang ◽  
Filip Gasior ◽  
Chunpei Lee ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Contractile Function ◽  
Polyol Pathway ◽  
Isolated Rat Heart ◽  
Rate Pressure Product ◽  
Saline Control ◽  
Binding Motif ◽  
Dependent Manner ◽  
Cardiac Contractile Function ◽  
Akt Activation

We have recently shown that pharmacologic inhibition of PTEN significantly increases cardiac arrest survival in a mouse model, however, this protection required pretreatment 30 min prior to the arrest. To improve the onset of PTEN inhibition during cardiac arrest treatment, we have designed a TAT fused cell-permeable peptide (TAT-PTEN9c) based on the c-terminal PDZ binding motif of PTEN for rapid tissue delivery and protection. Western blot analysis demonstrated that TAT-PTEN9c peptide significantly enhanced Akt activation in mouse cardiomyocytes in a concentration- and time-dependent manner. Mice were subjected to 8 min asystolic arrest followed by CPR, and 30 mice with successful CPR were then randomly assigned to receive either saline or TAT-PTEN9c treatment. Survival was significantly increased in TAT-PTEN9c treated mice compared with that of saline control at 4 h after CPR. The treated mice had increased Akt phosphorylation at 30 min resuscitation with significantly decreased sorbitol content in heart or brain tissues and reduced release of taurine and glutamate in blood, suggesting improved glucose metabolism. In an isolated rat heart Langendorff model, direct effects of TAT-PTEN9c on cardiac function were measured for 20 min following 20 min global ischemia. Rate pressure product was reduced by >25% for both TAT vehicle and non-treatment groups following arrest. Cardiac contractile function was completely recovered with TAT-PTEN9c treatment given at the start of reperfusion. We conclude that TAT-PTEN9c enhances Akt activation and decreases glucose shunting to the polyol pathway in critical organs, thereby preventing osmotic injury and early cardiovascular collapse and death.

scholarly journals EFFECT OF CALCIUM LOAD ON HEART FUNCTION, MPTP OPENING IN SITU AND UCP2/3 MRNA EXPRESSION IN THE HEART OF TRAINED RATS

2020 ◽  
Vol 66 (6) ◽  
pp. 3-12
Author(s):  
Yu.V. Goshovska ◽  
◽  
N.A. Strutynska ◽  
V.F. Sagach ◽  
◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Mrna Expression ◽  
Mitochondrial Permeability Transition ◽  
Contractile Function ◽  
Heart Function ◽  
Isolated Heart ◽  
Sharp Decrease ◽  
Calcium Content ◽  
Calcium Load

We have studied the effect of calcium load (1.7 to 15 mmol/l in perfusate) on isolated heart function, mitochondrial factor release (as a marker of mitochondrial permeability transition pore, MPTP), and cardiac uncoupling proteins (UCP2/3) mRNA expression in untrained and trained rats (swimming for 4 weeks). It was found that the improvement in the isolated heart function of trained rats was accompanied by an increase in the expression of UCP3, but not UCP2. A gradual increase of the calcium content in the perfusate led to an increase in contractile function, more pronounced in trained rats. However, 10 mmol/l and higher concentration of calcium led to arrhythmia and drastic decrease in contractility of isolated heart more obvious in untrained rats. Swimming course prevented the calcium-induced release of mitochondrial factor exerting a stabilizing effect on mitochondrial membranes which was, however, diminished by a nitric oxide synthesis blocker (L-NAME). We have found that UCPs genes expression is calcium-sensitive: an increase in UCP3 mRNA at 5 mmol of calcium and a sharp decrease in UCP2/3 expression at 12.5 mmol/l of calcium in perfusate in both trained and untrained rats indicating the participation of UCPs in the regulation of calcium homeostasis. Our data suggest that the calcium load may serve as a test for in situ MPTP titration. Activation of UCPs together with up-regulated nitric oxide may play a protective role against increasing extracellular calcium inhibiting MPTP formation during physical trainings.

scholarly journals Hemistepsin A suppresses colorectal cancer growth through inhibiting pyruvate dehydrogenase kinase activity

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ling Jin ◽  
Eun-Yeong Kim ◽  
Tae-Wook Chung ◽  
Chang Woo Han ◽  
So Young Park ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cells ◽  
Pyruvate Dehydrogenase ◽  
Cancer Metabolism ◽  
Aerobic Glycolysis ◽  
Lactate Production ◽  
Pyruvate Dehydrogenase Kinase ◽  
Cancer Drug ◽  
Potential Candidate ◽  
Mitochondrial Ros

AbstractMost cancer cells primarily produce their energy through a high rate of glycolysis followed by lactic acid fermentation even in the presence of abundant oxygen. Pyruvate dehydrogenase kinase (PDK) 1, an enzyme responsible for aerobic glycolysis via phosphorylating and inactivating pyruvate dehydrogenase (PDH) complex, is commonly overexpressed in tumors and recognized as a therapeutic target in colorectal cancer. Hemistepsin A (HsA) is a sesquiterpene lactone isolated from Hemistepta lyrata Bunge (Compositae). Here, we report that HsA is a PDK1 inhibitor can reduce the growth of colorectal cancer and consequent activation of mitochondrial ROS-dependent apoptotic pathway both in vivo and in vitro. Computational simulation and biochemical assays showed that HsA directly binds to the lipoamide-binding site of PDK1, and subsequently inhibits the interaction of PDK1 with the E2 subunit of PDH complex. As a result of PDK1 inhibition, lactate production was decreased, but oxygen consumption was increased. Mitochondrial ROS levels and mitochondrial damage were also increased. Consistent with these observations, the apoptosis of colorectal cancer cells was promoted by HsA with enhanced activation of caspase-3 and -9. These results suggested that HsA might be a potential candidate for developing a novel anti-cancer drug through suppressing cancer metabolism.

Neuroprotective Effects of a GLP-2 Analogue in the MPTP Parkinson’s Disease Mouse Model

2021 ◽  
pp. 1-15
Author(s):  
Zijuan Zhang ◽  
Li Hao ◽  
Ming Shi ◽  
Ziyang Yu ◽  
Simai Shao ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Mouse Model ◽  
Neurodegenerative Disorder ◽  
Enzyme Linked Immunosorbent Assay ◽  
Protective Effects ◽  
Neuroprotective Effects ◽  
Expression Levels ◽  
Dual Agonist

Background: Glucagon-like peptide 2 (GLP-2) is a peptide hormone derived from the proglucagon gene expressed in the intestines, pancreas and brain. Some previous studies showed that GLP-2 improved aging and Alzheimer’s disease related memory impairments. Parkinson’s disease (PD) is a progressive neurodegenerative disorder, and to date, there is no particular medicine reversed PD symptoms effectively. Objective: The aim of this study was to evaluate neuroprotective effects of a GLP-2 analogue in the 1-Methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) PD mouse model. Methods: In the present study, the protease resistant Gly(2)-GLP-2 (50 nmol/kg ip.) analogue has been tested for 14 days by behavioral assessment, transmission electron microscope, immunofluorescence histochemistry, enzyme-linked immunosorbent assay and western blot in an acute PD mouse model induced by MPTP. For comparison, the incretin receptor dual agonist DA5-CH was tested in a separate group. Results: The GLP-2 analogue treatment improved the locomotor and exploratory activity of mice, and improved bradykinesia and movement imbalance of mice. Gly(2)-GLP-2 treatment also protected dopaminergic neurons and restored tyrosine hydroxylase expression levels in the substantia nigra. Gly(2)-GLP-2 furthermore reduced the inflammation response as seen in lower microglia activation, and decreased NLRP3 and interleukin-1β pro-inflammatory cytokine expression levels. In addition, the GLP-2 analogue improved MPTP-induced mitochondrial dysfunction in the substantia nigra. The protective effects were comparable to those of the dual agonist DA5-CH. Conclusion: The present results demonstrate that Gly(2)-GLP-2 can attenuate NLRP3 inflammasome-mediated inflammation and mitochondrial damage in the substantia nigra induced by MPTP, and Gly(2)-GLP-2 shows neuroprotective effects in this PD animal model.

Sign in / Sign up

Export Citation Format

Share Document