scholarly journals Dynamic alteration of adiponectin/adiponectin receptor expression and its impact on myocardial ischemia/reperfusion in type 1 diabetic mice

2011 ◽  
Vol 301 (3) ◽  
pp. E447-E455 ◽  
Author(s):  
Yanzhuo Ma ◽  
Yi Liu ◽  
Shaowei Liu ◽  
Yan Qu ◽  
Rutao Wang ◽  
...  

The present study determined the dynamic change of adiponectin (APN, a cardioprotective adipokine), its receptor expression, and their impact upon myocardial ischemia/reperfusion (MI/R) injury during type 1 diabetes mellitus (T1DM) progression, and involved underlying mechanisms. Diabetic state was induced in mice via multiple intraperitoneal injections of low-dose streptozotocin. The dynamic change of plasma APN concentration and cardiac APN receptor-1 and -2 (AdipoR1/2) expression were assessed immediately after diabetes onset (0 wk) and 1, 3, 5, and 7 wk thereafter. Indicators of MI/R injury (infarct size, apoptosis, and LDH release) were determined at 0, 1, and 7 wk of DM duration. The effect of APN on MI/R injury was determined in mice subjected to different diabetic durations. Plasma APN levels (total and HMW form) increased, whereas cardiac AdipoR1 expression decreased early after T1DM onset. With T1DM progression, APN levels were reduced and cardiac AdipoR1 expression increased. MI/R injury was exacerbated with T1DM progression in a time-dependent manner. Administration of globular APN (gAD) failed to attenuate MI/R injury in 1-wk T1DM mice, while an AMP-activated protein kinase (AMPK) activator (AICAR) reduced MI/R injury. However, administration of gAD (and AICAR) reduced infarct size and cardiomyocyte apoptosis in 7-wk T1DM mice. In conclusion, our results demonstrate a dynamic dysfunction of APN/AdipoR1 during T1DM progression. Reduced cardiac AdipoR1 expression and APN concentration may be responsible for increased I/R injury susceptibility at early and late T1DM stages, respectively. Interventions bolstering AdipoR1 expression during early T1DM stages and APN supplementation during advanced T1DM stages may potentially reduce the myocardial ischemic injury in diabetic patients.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Shahid Baba ◽  
Deqing zhang ◽  
David Hoetker ◽  
Yiru Guo ◽  
Aruni Bhatnagar

Even though myocardial ischemia/reperfusion (I/R) remains the leading cause of death, the underlying mechanisms remain incompletely understood. Increased formation of reactive carbonyl has been shown to be a common biochemical feature of I/R injury. These carbonyls are generated from the oxidation of proteins and membrane lipids. Reactive carbonyls such as methylglyoxal are generated from increased glycolytic activity during ischemia. Previous work in our lab has shown that the endogenous dipeptide carnosine (β-alanine-histidine) quenches both protein and lipid derived carbonyls. It can also buffer changes in intracellular pH and chelate metals that catalyze ROS production. In the heart, carnosine is synthesized by the ATP grasp enzyme (ATPGD1). Hence, we examined whether overexpression of ATPGD1 could increase carnosine synthesis in the heart and attenuate I/R injury. To overexpress ATPGD1, we generated mice in which the expression of the transgene was driven by cardiospecific α-MHC promoter. Two different ATPGD1Tg mouse lines were generated, which showed 10-15 fold higher abundance of ATPGD1 protein in the heart compared with their wild-type (WT) littermates. Cardiac levels of the histidyl dipeptides anserine and carnosine were approximately 100 fold higher in the ATPGD1Tg than WT mice hearts (WT: anserine 1.8±0.3 pmoles/mg protein, carnosine 6±1 pmoles/mg protein; ATPGD1-Tg: anserine 114±15 pmoles/mg protein, carnosine 615±44 pmoles/mg protein). No changes in the levels of these dipeptides were observed in other tissues of the ATPGD1Tg mice. Echocardiographic analysis showed that ATPGD1 overexpression did not affect cardiac function. When subjected to 30 min of coronary occlusion followed by 24 h of reperfusion, the infarct size was significantly lower in ATPGD1Tg than WT mice. Infarct size as the area of risk of left ventricle was 59±3.02% in WT mice and 38±2.73% in the ATPGD1-Tg mice (p<0.05 vs WT; n=7-8), indicating that increasing carnosine levels attenuates myocardial I/R injury. These findings reveal a novel cardioprotective role of endogenous histidyl dipeptides in decreasing I/R injury and suggest that treatment with such peptides may be a potential therapy for decreasing myocardial I/R injury and its progression of heart failure.


2021 ◽  
Vol 8 ◽  
Author(s):  
Hui-Hui Guo ◽  
Xin-Yue Jing ◽  
Hui Chen ◽  
Hou-Xi Xu ◽  
Bing-Mei Zhu

Electroacupuncture (EA) can help reduce infarct size and injury resulting from myocardial ischemia/reperfusion (I/R); however, the underlying molecular mechanism remains unknown. We previously reported that STAT5 plays a critical role in the cardioprotective effect of remote ischemic preconditioning (RIPC). Here, we assessed the effects of electroacupuncture pretreatment (EAP) on myocardial I/R injury in the presence and/or absence of Stat5 in mice and investigated whether EAP exerts its cardioprotective effects in a STAT5-dependent manner. Adult Stat5fl/fl and Stat5-cKO mice were exposed to EAP at Neiguan (PC6) for 7 days before the induction of I/R injury by left anterior descending (LAD) coronary artery ligation. The myocardial infarct size (IS), area at risk, and apoptotic rate of cardiomyocytes were detected. RT-qPCR and western blotting were used to measure gene and protein expression, respectively, in homogenized heart tissues. RNA-seq was used to identify candidate genes and pathways. Our results showed that EAP decreased IS and the rate of cardiomyocyte apoptosis. We further found that STAT5 was activated by EAP in Stat5fl/fl mice but not in Stat5-cKO mice, whereas the opposite was observed for STAT3. Following EAP, the levels of the antiapoptotic proteins Bcl-xL, Bcl-2, and p-AKT were increased in the presence of Stat5, while that of interleukin 10 (IL-10) was increased in both Stat5fl/fl and Stat5-cKO. The gene expression profile in heart tissues was different between Stat5fl/fl and the Stat5-cKO mice with EAP. Importantly, the top 30 DEGs under EAP in the Stat5-cKO mice were enriched in the IL-6/STAT3 signaling pathway. Our results revealed for the first time that the protective effect of EAP following myocardial I/R injury was attributable to, but not dependent on, STAT5. Additionally, we found that EAP could activate STAT3 signaling in the absence of the Stat5 gene, and could also activate antiapoptotic, survival, and anti-inflammatory signaling pathways.


2018 ◽  
Vol 24 (3) ◽  
pp. 262-268 ◽  
Author(s):  
Jin Cheng ◽  
Chuang Sun ◽  
Jingyu Zhang ◽  
Qing Zou ◽  
Qimeng Hao ◽  
...  

Myocardial ischemia–reperfusion (IR) injury is associated with high disability and mortality worldwide. This study was to explore the roles of dioscin in the myocardial IR rats and discover the related molecular mechanisms. Rats were divided into 5 groups: sham, IR, IR + 15 mg/kg dioscin, IR + 30 mg/kg dioscin, and IR + 60 mg/kg dioscin. Heart rate (HR), mean arterial blood pressure (MAP), and rate pressure product (RPP) were evaluated at 10 minutes before ischemia, immediately after ischemia, and at the beginning, middle, and end of reperfusion. Arrhythmia score and myocardial infarct size were examined in rats of all groups. The serum creatine kinase-muscle/brain (CKMB) and cardiac troponin I (cTnI) levels were analyzed via enzyme-linked immunosorbent assay. Protein amount of total connexin 43 (T-Cx43) and phosphorylated connexin 43 (P-Cx43) was evaluated by Western blot. Ischemia reperfusion significantly decreased HR, MAP, and RPP of rats compared to the sham group. However, dioscin significantly attenuated the above phenomena in a dose-dependent manner. Dioscin markedly inhibited IR-induced increase in arrhythmias score, infarct size, and serum CKMB and cTnI levels. In addition, dioscin strikingly induced IR-repressed expression of T-Cx43 and P-Cx43. Our results suggested that dioscin pretreatment exhibited protective effects against myocardial IR injury. Moreover, we found that dioscin attenuated myocardial IR-induced ventricular arrhythmias via upregulating Cx43 expression and activation.


2021 ◽  
Vol 8 ◽  
Author(s):  
Maya Dia ◽  
Alexandre Paccalet ◽  
Bruno Pillot ◽  
Christelle Leon ◽  
Michel Ovize ◽  
...  

In front of the failure to translate from bench to bedside cardioprotective drugs against myocardial ischemia-reperfusion, research scientists are currently revising their animal models. Owing to its growing incidence nowadays, type 2 diabetes (T2D) represents one of the main risk factors of co-morbidities in myocardial infarction. However, discrepancies exist between reported animal and human studies. Our aim was here to compare the impact of diabetes on cell death after cardiac ischemia-reperfusion in a human cohort of ST-elevation myocardial infarction (STEMI) patients with a diet-induced mouse model of T2D, using a high-fat high-sucrose diet for 16 weeks (HFHSD). Interestingly, a small fraction (&lt;14%) of patients undergoing a myocardial infarct were diabetic, but treated, and did not show a bigger infarct size when compared to non-diabetic patients. On the contrary, HFHSD mice displayed an increased infarct size after an in vivo cardiac ischemia-reperfusion, together with an increased cell death after an in vitro hypoxia-reoxygenation on isolated cardiomyocytes. To mimic the diabetic patients' medication profile, 6 weeks of oral gavage with Metformin was performed in the HFHSD mouse group. Metformin treatment of the HFHSD mice led to a similar extent of lower cell death after hypoxia-reoxygenation as in the standard diet group, compared to the HFHSD cardiomyocytes. Altogether, our data highlight that due to their potential protective effect, anti-diabetic medications should be included in pre-clinical study of cardioprotective approaches. Moreover, since diabetic patients represent only a minor fraction of the STEMI patients, diabetic animal models may not be the most suitable translatable model to humans, unlike aging that appears as a common feature of all infarcted patients.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xinhao Liu ◽  
Hui Chen ◽  
Zhibing Yan ◽  
Lei Du ◽  
Dou Huang ◽  
...  

AbstractDiabetes mellitus (DM) exhibits a higher sensitivity to myocardial ischemia/reperfusion (I/R) injury and may compromise the effectiveness of cardioprotective interventions, including ischemic preconditioning. We previously found that liver ischemic preconditioning (RLIPC) could limit infarct size post I/R in non-diabetic rat hearts and further exerted anti-arrhythmic effects in diabetic or non-diabetic rats after myocardial I/R, however, little is known regarding the effect of RLIPC on infarct-sparing in diabetic hearts. In this study, we evaluated the protective effects of RLIPC on I/R injury in streptozotocin-induced type 1 diabetic rats. Type 1 diabetes mellitus was induced by one-time intraperitoneal injection of streptozotocin in Sprague–Dawley rats. Rats were exposed to 45 min of left anterior descend in (LAD) coronary artery occlusion, followed by 3 h of reperfusion. For liver ischemic preconditioning, four cycles of 5 min of liver I/R stimuli were performed before LAD occlusion. The cardioprotective effect of RLIPC was determined in diabetic rats. Compared to non-RLIPC treated DM rats, RLIPC treatment significantly reduced infarct size and cardiac tissue damage, inhibited apoptosis in diabetic hearts post I/R. RLIPC also improved cardiac functions including LVESP, LVEDP, dp/dtmax, and − dp/dtmax. In addition, RLIPC preserved cardiac morphology by reducing the pathological score post I/R in diabetic hearts. Finally, Westernblotting showed that RLIPC stimulated phosphorylation of ventricular GSK-3β and STAT-5, which are key components of RISK and SAFE signaling pathways. Our study showed that liver ischemic preconditioning retains strong cardioprotective properties in diabetic hearts against myocardial I/R injury via GSK-3β/STAT5 signaling pathway.


2020 ◽  
Author(s):  
Xinhao Liu ◽  
Hui Chen ◽  
Zhibing Yan ◽  
Lei Du ◽  
Dou Huang ◽  
...  

Abstract BACKGROUND: Diabetes mellitus (DM) exhibits a higher sensitivity to myocardial ischemia/reperfusion(I/R)injury and may compromise the effectiveness of cardioprotective interventions, including ischemic preconditioning. We previously found that liver ischemic preconditioning(RLIPC) could limit infarct size post I/R in normal rat hearts and further exerted anti-arrhythmic effects in diabetic or non-diabetic rats after myocardial I/R, however, little is known regarding the effect of RLIPC on infarct-sparing in diabetic hearts. In this study, we evaluated the protective effects of RLIPC on I/R injury in streptozotocin (STZ)-induced type 1 diabetic rats.METHODS:Type 1 diabetes mellitus was induced by one-time intraperitoneal injection of streptozotocin in Sprague–Dawley rats. Rats were exposed to 45 min of left anterior descendin(LAD) coronary artery occlusion, followed by 3 h of reperfusion. For liver ischemic preconditioning, four cycles of 5 min of liver I/R stimuli were performed before LAD occlusion. the cardioprotective effect of RLIPC was determined in diabetic rats.RESULTS: Compared to non-RLIPC treated DM rats, RLIPC treatment significantly reduced infarct size in diabetic hearts post I/R. RLIPC also improved cardiac functions including LVESP, LVEDP, dp/dtmax, and -dp/dtmax. In addition, RLIPC could largely preserved cardiac morphology by reducing the pathological score post I/R in diabetic hearts. Finally, western blotting analysis showed that RLIPC stimulated phosphorylation of ventricular GSK-3β and STAT-5, which are key components of RISK and SAFE signaling pathways.


2018 ◽  
Vol 49 (4) ◽  
pp. 1476-1491 ◽  
Author(s):  
Shu-Bo  Zhang ◽  
Tie-Jun Liu ◽  
Guo-Hua Pu ◽  
Bao-Yong Li ◽  
Xiao-Zeng Gao ◽  
...  

Background/Aims: Long non-coding RNA (lncRNA) and glucagon-like peptide 1 receptor (GLP-1R) are crucial for heart development and for adult heart structural maintenance and function. Herein, we performed a study to explore the effect of lncRNA LINC00652 (LINC00652) on myocardial ischemia-reperfusion (I/R) injury by targeting GLP-1R through the cyclic adenosine monophosphate-protein kinase A (cAMP/PKA) pathway. Methods: Bioinformatics software was used to screen the long-chain non-coding RNAs associated with myocardial ischemia-reperfusion and to predict target genes. The mRNA and protein levels of LINC00652, GLP-1R and CREB were detected by RT-qPCR and western blotting. In order to identify the interaction between LINC00652 and myocardial I/R injury, the cardiac function, the hemodynamic changes, the pathological changes of the myocardial tissues, the myocardial infarct size, and the apoptosis of myocardial cells of mice were measured. Meanwhile, the levels of serum IL-1β and TNF-α were detected. Results: LINC00652 was overexpressed in the myocardial cells of mice with myocardial I/R injury. GLP-1R is the target gene of LINC00652. We also determined higher levels of LINC00652 and GLP-1R in the I/R modeled mice. Additionally, si-LINC00652 decreased cardiac pathology, infarct size, apoptosis rates of myocardial cells, and levels of IL-1β and TNF-α, and increased GLP-1R expression cardiac function, normal hemodynamic index, and the expression and phosphorylation of GLP-1R and CREB proteins. Conclusion: Taken together, our key findings of the present highlight LINC00652 inhibits the activation of the cAMP/PKA pathway by targeting GLP-1R to reduce the protective effect of sevoflurane on myocardial I/R injury in mice.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Jingyuan Li ◽  
Victor R Grijalva ◽  
Srinivasa T Reddy ◽  
Mansoureh Eghbali

Objectives: Paraoxonases (PON) gene family consists of three proteins PON1, PON2, and PON3. PON2 is an intracellular membrane-associated protein that is widely expressed in vascular cells and many tissues. At the subcellular level, PON2 is localized to both the ER and mitochondria, and protects against oxidative stress. Hypothesis: The aim of this study was to investigate the role of PON2 in myocardial ischemia reperfusion injury. Methods: PON2 deficient (PON2-/-) and WT male mice were subjected to in-vivo ischemia/reperfusion injury. The left anterior descending coronary artery was occluded for 30 min followed by 24 hr of reperfusion. The infarct size, mitochondrial calcium retention capacity (CRC) and reactive oxygen species (ROS) generation were measured. The expression of C/EBP homologous protein (CHOP), GSK3b and phosphate GSK3b protein were examined by Western Blot. The number of animals was 5-7/group and data were expressed as mean±SEM. T test were used for statistical analysis. Probability values <0.05 were considered statistically significant. Results: The infarct size was ~2 fold larger in PON2 deficient mice compared to WT mice (p<0.05). The threshold for opening of mitochondrial permeability transition pore (mPTP) in response to calcium overload was much lower in PON2-/- mice compared with WT mice (173±19 in PON2-/-, 250±41 in WT, nmol/mg-mitochondrial protein, p<0.05). The ROS production was ~2 fold higher in isolated cardiac mitochondria from PON2-/- mice compared with WT mice (p<0.05). ER stress protein CHOP increased significantly in PON2-/- mice compared to WT mice (normalized to WT: 1±0.05 in WT, 1.66±0.08 in PON2-/-, p<0.001). Phospho-GSK3b level was significantly downregulated in in PON2-/- mice compared to WT mice (pGSK3b/GSK3b normalized to WT: 1±0.06 in WT 0.67±0.08 in PON2-/-, p<0.05). Conclusions: PON2 regulates myocardial ischemia/reperfusion injury via inhibiting the opening of mPTP, which is associated with reduced mitochondria ROS production, deactivation of ER stress signaling CHOP and GSK3b.


1994 ◽  
Vol 24 (6) ◽  
pp. 921-928 ◽  
Author(s):  
Shawn C. Black ◽  
Michael R. Gralinski ◽  
James G. McCormack ◽  
Edward M. Driscoll ◽  
Benedict R. Lucchesi

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