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.

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.

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 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 17773: Peptide Inhibition of PTEN Increases Mouse Survival after Sudden Cardiac Arrest

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Xiangdong Zhu ◽  
Huashan Wang ◽  
Youhua Wang ◽  
Jing Li ◽  
Alan R Leff ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Western Blot ◽  
Pdz Domain ◽  
Sudden Cardiac Arrest ◽  
Saline Control ◽  
Heart Cells ◽  
Protein Transduction ◽  
Cardiovascular Collapse ◽  
Tat Protein ◽  
Akt Activation

Introduction: We recently reported that TAT fusion proteins designed to activate versus inhibit the Akt related phosphatase PTEN in heart cells respectively worsen or significantly improve ischemia/reperfusion injury and contractile functional recovery. We therefore designed a short 20 amino acid peptide PTEN inhibitor, TAT-PTEN9c, for rapid tissue delivery and tissue protection after mouse sudden cardiac arrest (SCA). TAT-PTEN9c contains a TAT protein transduction domain fused to the PTEN C-terminal 9 amino acids of the PDZ-domain binding motif. We hypothesized that TAT-PTEN9c blocks PTEN membrane localization and activation, with corresponding tissue Akt activation and improved SCA survival. Methods: Mouse cardiomyocytes were isolated from 1-3 day old mouse pups. Western blot was used to determine the efficacy of TAT-PTEN9c for enhancing Akt phosphorylation in mouse cardiomyocytes exposed to oxidant (H2O2) stress. C57BL6 mice were subjected to an established potassium-induced 8 min SCA protocol. MAP, ETCO2, body temperature and ECG were recorded until 4 h after successful cardiopulmonary resuscitation (CPR). TAT-PTEN9c (7.8 mg/kg) was given intravenously (IV) immediately after CPR (n=10) and a 2nd dose in an additional 5 mice was given at 60 min. IV administration of TAT-GFP was used to measure the kinetics of heart and brain tissue TAT protein delivery. Results: The designed TAT-PTEN9c peptide significantly enhanced Akt activation in neonatal mouse cardiomyoctes in a concentration-dependent manner. 30 mice with successful CPR were randomly assigned to receive either saline or TAT-PTEN9c. Survival (versus cardiovascular collapse and death) was significantly increased in TAT-PTEN9c treated group compared with that of saline control at 2 h (14/15, 93% vs. 9/15, 60%, P < 0.05) and at 4 h (10/15, 67% vs. 6/15, 40%, P < 0.05) after CPR. Western blot and immunohistochemistry showed that TAT protein transduction in heart and brain was diffuse and occurred within 5 min after IV administration. Conclusion: TAT-PTEN9c can be used after CPR in a mouse SCA model to rapidly enhance Akt activation in critical organs and prevent early cardiovascular collapse and death.

scholarly journals Cardioprotective Natural Compound Pinocembrin Attenuates Acute Ischemic Myocardial Injury via Enhancing Glycolysis

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yanjun Zheng ◽  
Guoqing Wan ◽  
Bo Yang ◽  
Xuefeng Gu ◽  
Jingrong Lin
Keyword(s):  
Contractile Function ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
Glycolytic Enzyme ◽  
Isolated Rat Heart ◽  
Cardiac Contractile Function ◽  
Direct Stimulation ◽  
Underlying Mechanisms

Purpose. Emerging evidence has shown that pinocembrin protects the myocardium from ischemic injury in animals. However, it is unknown whether it has cardioprotection when given at the onset of reperfusion. Also, mechanisms mediating the cardioprotective actions of pinocembrin were largely unknown. Thus, this study is aimed at investigating the effects of pinocembrin postconditioning on ischemia-reperfusion (I/R) injury and the underlying mechanisms. Methods. The in vivo mouse model of myocardial I/R injury, ex vivo isolated rat heart with global I/R, and in vitro hypoxia/reoxygenation (H/R) injury model for primary cardiomyocytes were used. Results. We found that pinocembrin postconditioning significantly reduced the infarct size and improved cardiac contractile function after acute myocardial I/R. Mechanically, in primary cardiomyocytes, we found that pinocembrin may confer protection in part via direct stimulation of cardiac glycolysis via promoting the expression of the glycolytic enzyme, PFKFB3. Besides, PFKFB3 inhibition abolished pinocembrin-induced glycolysis and protection in cardiomyocytes. More importantly, PFKFB3 knockdown via cardiotropic adeno-associated virus (AAV) abrogated cardioprotective effects of pinocembrin. Moreover, we demonstrated that HIF1α is a key transcription factor driving pinocembrin-induced PFKFB3 expression in cardiomyocytes. Conclusions. In conclusion, these results established that the acute cardioprotective benefits of pinocembrin are mediated in part via enhancing PFKFB3-mediated glycolysis via HIF1α, which may provide a new therapeutic target to impede the progression of myocardial I/R injury.

Impaired cardiac function and IGF-I response in myocytes from calmodulin-diabetic mice: role of Akt and RhoA

2003 ◽  
Vol 284 (2) ◽  
pp. E366-E376 ◽  
Author(s):  
Jinhong Duan ◽  
Hai-Ying Zhang ◽  
Steven D. Adkins ◽  
Bonnie H. Ren ◽  
Faye L. Norby ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Contractile Function ◽  
Diabetic Mouse ◽  
Maximal Velocity ◽  
Mrna Levels ◽  
Cardiac Contractile Function ◽  
Fluorescent Intensity ◽  
Akt Activation ◽  
Receptor Mrna ◽  
Igf I

This study characterized the cardiac contractile function and IGF-I response in a transgenic diabetic mouse model. Mechanical properties were evaluated in cardiac myocytes from OVE26 diabetic and FVB wild-type mice, including peak shortening (PS), time to PS (TPS), time to 90% relengthening (TR90) and maximal velocity of shortening/relengthening (±d L/d t). Intracellular Ca2+ was evaluated as Ca2+-induced Ca2+ release [difference in fura 2 fluorescent intensity (ΔFFI)] and fluorescence decay rate (τ). Sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)2a, phospholamban (PLB), Na+-Ca2+ exchanger (NCX), GLUT4, and the serine-threonine kinase Akt were assessed by Western blot. RhoA and IGF-I/IGF-I receptor mRNA levels were determined by RT-PCR and Northern blot. OVE26 myocytes displayed decreased PS, ±d L/d t, and ΔFFI associated with prolonged TPS, TR90, and τ. SERCA2a, NCX, and Akt activation were reduced, whereas PLB and RhoA were enhanced in OVE26 hearts. GLUT4 was unchanged. IGF-I enhanced PS and ΔFFI in FVB but not OVE26 myocytes. IGF-I mRNA was increased, but IGF-I receptor mRNA was reduced in OVE26 hearts and livers. These results validate diabetic cardiomyopathy in OVE26 mice due to reduced SERCA2, NCX, IGF-I response, and Akt activation associated with enhanced RhoA level, suggesting a therapeutic potential for Akt and RhoA.

scholarly journals Loss of a novel striated muscle-enriched mitochondrial protein Coq10a enhances postnatal cardiac hypertrophic growth

2019 ◽  
Author(s):  
Kentaro Hirose ◽  
Steven Chang ◽  
Hongyao Yu ◽  
Jiajia Wang ◽  
Emanuele Barca ◽  
...  
Keyword(s):  
Mitochondrial Biogenesis ◽  
Striated Muscle ◽  
Contractile Function ◽  
Partial Agonist ◽  
Mitochondrial Protein ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Cardiac Contractile Function ◽  
Peroxisome Proliferator Activated Receptor ◽  
Hypertrophic Growth

AbstractPostnatal mammalian cardiomyocytes undergo a major transition from hyperplasia (increases in cell numbers) to hypertrophy (expansion in cell size). This process is accompanied by rapid mitochondrial biogenesis and metabolic switches to meet the demand of increased cardiac output. Although most mitochondrial components express ubiquitously, recent transcriptomic and proteomic analyses have discovered numerous tissue-specific mitochondrial proteins whose physiological functions are largely unknown. Here we report that a highly evolutionarily conserved mitochondrial protein Coq10a is predominantly expressed in mammalian cardiac and skeletal muscles, and is highly up-regulated around birth in a thyroid hormone-dependent manner. Deletion of Coq10a by CRISPR/Cas9 leads to enhanced cardiac growth after birth. Surprisingly, adult Coq10a mutant mice maintain the hypertrophic heart phenotype with increased levels of coenzyme Q (CoQ) per cardiomyocyte, preserved cardiac contractile function and mitochondrial respiration, which contrasts with reported mice and humans with mutations in other Coq family genes. Further RNA-seq analysis and mitochondrial characterization suggest an increase of mitochondrial biogenesis in the Coq10a mutant heart as a possible consequence of Peroxisome proliferator-activated receptor Gamma Coactivator 1-alpha (PGC1α) activation, consistent with a recent intriguing report that CoQ may function as a natural ligand and partial agonist of Peroxisome Proliferator-Activated Receptor (PPAR) α/γ. Taken together, our study reveals a previously unknown function of a novel striated muscle-enriched mitochondrial protein Coq10a in regulating postnatal heart growth.

scholarly journals Thyroid hormone receptor-α and vascular function

2012 ◽  
Vol 302 (9) ◽  
pp. C1346-C1352 ◽  
Author(s):  
Ayako Makino ◽  
Hong Wang ◽  
Brian T. Scott ◽  
Jason X.-J. Yuan ◽  
Wolfgang H. Dillmann
Keyword(s):  
Thyroid Hormone ◽  
Vascular Function ◽  
Vascular Tone ◽  
Thyroid Hormone Receptor ◽  
Contractile Function ◽  
Dependent Manner ◽  
Channel Activity ◽  
Cardiac Contractile Function ◽  
Vascular Contraction ◽  
Regulation Of Vascular Tone

Thyroid hormone (TH) treatment exerts beneficial effects on the cardiovascular system: it lowers cholesterol and LDL levels and enhances cardiac contractile function. However, little is known about the effect of TH on vascular function or the functional role of TH receptors (TRs) in the regulation of vascular tone. We have investigated the contribution of TRs to vascular contractility in the heart. Among different TR subtype-specific knockout (KO) mice, vascular contraction was significantly enhanced in coronary arteries isolated from TRα KO compared with wild-type mice, while chronic TH treatment significantly attenuated coronary vascular contraction. We found that TRα is the predominant TR in mouse coronary smooth muscle cells (SMCs). Coronary SMCs isolated from TRα KO mice exhibited a significant decrease in K+channel activity, whereas TH treatment increased K+channel activity in a dose-dependent manner. These data suggest that TRα in SMCs has prominent effects on regulation of vascular tone and TH treatment helps decrease coronary vascular tone by increasing K+channel activity through TRα in SMCs.

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