Abstract 11302: Sevoflurane Pre-Conditioning Effectively Ameliorates Diabetic Myocardial Ischemia/Reperfusion Injury via Differential Regulation of p38 and ERK

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Jianli Zhao ◽  
Jingjing Li ◽  
Rui Li ◽  
Liyuan Jiao ◽  
Yanqing Zhang ◽  
...  

Diabetes (DB) significantly exacerbates myocardial ischemia/reperfusion (MI/R) injury. Unfortunately, conventional pre-conditioning (PreCon) provides diminished cardioprotection during DB, due partially to impaired AMP-activated protein kinase (AMPK) signaling. The current study investigated whether PreCon by inhaled anesthetic sevoflurane (SF-PreCon) remains protective in DB, and if so, to dissect the involved mechanisms. Non-diabetic (ND) or high-fat diet-induced DB mice were subjected to MI/R and randomized into control and SF-PreCon (3 cycles of 15 minute-exposures to 2% sevoflurane prior to MI) groups. As expected, SF-PreCon significantly reduced MI/R injury in ND mice. Importantly, SF-PreCon also significantly reduced MI/R injury in DB mice, as evidenced by reduced apoptosis (-23.1±1.6, P<0.01), decreased infarct size (-21.2±2.3%, P<0.01), and augmented cardiac function (+24±3.0%, P<0.01). To determine the role of AMPK in SF-PreCon-mediated cardioprotection, the effect of SF-PreCon upon MI/R injury was determined in cardiac specific AMPKα2 dominant negative overexpression mice (AMPK-DN). We demonstrate SF-PreCon remained cardioprotective in AMPK-DN mice. To explore the responsible molecular mechanisms, multiple cell-survival signaling molecules were screened. Interestingly, SF-PreCon differentially regulated mitogen-activated protein kinase (MAPK) family members in the MI/R heart. In ND mice, SF-PreCon dramatically reduced (-81±7.2%) MI/R-induced activation of p38, a pro-death MAPK, without significantly altering ERK and JNK. In DB and AMPK-DN mice, the inhibitory effect of SF-PreCon upon p38 activation was significantly blunted (DB: -8±2.1%) or virtually abolished (AMPK-DN). However, SF-PreCon significantly increased (P<0.05) phosphorylation of ERK1/2, a pro-survival MAPK. Collectively, we demonstrate SF-PreCon protected the heart via AMPK-dependent inhibition of pro-death MAPK in ND mice. However, SF-PreCon exerts its cardioprotective actions via AMPK-independent activation of pro-survival MAPK in DB mice. These results suggest SF-PreCon may be a superior intervention over conventional PreCon in DB patients, where AMPK signaling is impaired.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Dina Xie ◽  
Jianli Zhao ◽  
Rui Guo ◽  
Liyuan Jiao ◽  
Yanqing Zhang ◽  
...  

AbstractDiabetes mellitus (DM) significantly increases myocardial ischemia/reperfusion (MI/R) injury. During DM, cardioprotection induced by conventional pre-conditioning (PreCon) is decreased due to impaired AMP-activated protein kinase (AMPK) signaling. The current study investigated whether PreCon with inhaled anesthetic sevoflurane (SF-PreCon) remains cardioprotective during DM, and identified the involved mechanisms. Normal diet (ND) and high-fat diet (HFD)-induced DM mice were randomized into control and SF-PreCon (3 cycles of 15-minute period exposures to 2% sevoflurane) groups before MI/R. SF-PreCon markedly reduced MI/R injury in DM mice, as evidenced by improved cardiac function (increased LVEF and ±Dp/dt), decreased infarct size, and decreased apoptosis. To determine the relevant role of AMPK, the effect of SF-PreCon was determined in cardiac-specific AMPKα2 dominant negative expressing mice (AMPK-DN). SF-PreCon decreased MI/R injury in AMPK-DN mice. To explore the molecular mechanisms responsible for SF-PreCon mediated cardioprotection in DM mice, cell survival molecules were screened. Interestingly, in ND mice, SF-PreCon significantly reduced MI/R-induced activation of p38, a pro-death MAPK, without altering ERK and JNK. In DM and AMPK-DN mice, the inhibitory effect of SF-PreCon upon p38 activation was significantly blunted. However, SF-PreCon significantly increased phosphorylation of ERK1/2, a pro-survival MAPK in DM and AMPK-DN mice. We demonstrate that SF-PreCon protects the heart via AMPK-dependent inhibition of pro-death MAPK in ND mice. However, SF-PreCon exerts cardioprotective action via AMPK-independent activation of a pro-survival MAPK member in DM mice. SF-PreCon may be beneficial compared to conventional PreCon in diabetes or clinical scenarios in which AMPK signaling is impaired.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Xuejun Wang ◽  
Erin J Terpstra ◽  
Eduardo Callegari ◽  
Chengjun Hu ◽  
Hanming Zhang ◽  
...  

Cardiac proteasome functional insufficiency is implicated in a large subset of heart disease and has been experimentally demonstrated to play an essential role in cardiac proteotoxicity, including desmin-related cardiomyopathy and myocardial ischemia-reperfusion (I-R) injury. Pharmacological inhibition of phosphodiesterase 5 (PDE5) via sildenafil for example, which can stabilize cGMP and thereby increase cGMP-dependent protein kinase (PKG) activity, is consistently reported to protect against I-R injury; however, the underlying mechanism is not fully understood. We have recently discovered that PKG activation enhances proteasomal degradation of misfolded proteins (Ranek, et al. Circulation 2013), prompting us to hypothesize that proteasome-priming may contribute to cardioprotection-induced by PDE5 inhibition. Here we used a cardiomyocyte-restricted proteasome inhibition transgenic mouse line (Tg) and non-Tg (Ntg) littermates to interrogate the action of sildenafil on I-R injury created by left anterior descending artery (LAD) ligation (30 min) and release (24 hr). Sildenafil was administered 30 min before LAD ligation. Results showed that (1) the 26S proteasome activity of the Ntg I-R hearts was significantly elevated by sildenafil but this elevation was blocked in the Tg line; (2) the infarct size reduction by sildenafil treatment in Ntg mice was completely abolished in the Tg mice with the same treatment; and (3) systolic and diastolic function impairment after I/R was markedly attenuated in sildenafil-treated Ntg mice, but not in the sildenafil-treated Tg mice. Additionally, immunoprecipitation assays show that PKG interacted with the proteasome in cultured cardiomyocytes, and this interaction appeared to be augmented by sildenafil treatment. Moreover, in vitro incubation of active PKG with purified human 26S proteasomes increased proteasome peptidase activities and the phosphorylation at specific serine residues of a 19S proteasome subunit as revealed by “gel-free” nano-LC-MS/MS. We conclude that active PKG directly interacts with, phosphorylates, and increases the activities of, the proteasome and that proteasome priming mediates to cardioprotection of PDE5 inhibition against I-R injury.


Epigenomics ◽  
2019 ◽  
Vol 11 (15) ◽  
pp. 1733-1748 ◽  
Author(s):  
Wei Xiong ◽  
Yan Qu ◽  
Hongmei Chen ◽  
Jinqiao Qian

Emerging evidence has demonstrated that regulatory noncoding RNAs (ncRNAs), such as long noncoding RNAs (lncRNAs) and miRNAs, play crucial roles in the initiation and progress of myocardial ischemia-reperfusion injury (MIRI), which is associated with autophagy, apoptosis and necrosis of cardiomyocytes, as well as oxidative stress, inflammation and mitochondrial dysfunction. LncRNAs serve as a precursor or host of miRNAs and directly/indirectly affecting miRNAs via competitive binding or sponge effects. Simultaneously, miRNAs post-transcriptionally regulate the expression of genes by targeting various mRNA sequences due to their imperfect pairing with mRNAs. This review summarizes the potential regulatory role of lncRNA–miRNA–mRNA axes in MIRI and related molecular mechanisms of cardiac disorders, also provides insight into the potential therapies for MIRI-induced diseases.


2020 ◽  
Author(s):  
Jianfeng Chen ◽  
Mingming Zhang ◽  
Shouyan Zhang ◽  
Junlong Wu ◽  
Shufeng Xue

Abstract Background: This study aimed to investigate the regulatory effect of rno-microRNA-30c-5p (rno-miR-30c-5p) on myocardial ischemia reperfusion (IR) injury in rats and the underlying molecular mechanisms.Methods: A rat model of myocardial IR injury was established. The infarct size was detected by 2,3,5-triphenyltetrazolium chloride staining. The pathologic changes of myocardial tissues were detected by hematoxylin-eosin staining. The apoptosis of myocardial cells was measured by TUNEL staining and flow cytometry. The mRNA expression of rno-miR-30c-5p and Sirtuin 1 (SIRT1) was detected by quantitative real-time PCR. The levels of IL-1β, IL-6 and TNF-α were detected by enzyme linked immunosorbent assay. The protein expression of Bax, Bcl-2, caspase-3, p-IκBα, IκBα, p-NF-κB p65, NF-κB p65 and SIRT1 was detected by Western blot. The interaction between rno-miR-30c-5p and SIRT1 was predicted by TargetScan, and further identified by dual luciferase reporter gene and RNA immunoprecipitation assay.Results: The myocardial IR injury model was successfully established in rats. IR induced the myocardial injury in rats and increased the expression of rno-miR-30c-5p. Overexpression of rno-miR-30c-5p enhanced the inflammation, promoted the apoptosis, and activated NF-κB pathway in IR myocardial cells. SIRT1 was the target gene of rno-miR-30c-5p. Silencing of SIRT1 reversed the effects of rno-miR-30c-5p inhibitor on the apoptosis and NF-κB pathway in IR myocardial cells.Conclusions: Rno-miR-30c-5p promoted the myocardial IR injury in rats through activating NF-κB pathway and down-regulating SIRT1.


2019 ◽  
Vol 317 (3) ◽  
pp. C525-C533 ◽  
Author(s):  
Yu Tina Zhao ◽  
Jianfeng Du ◽  
Naohiro Yano ◽  
Hao Wang ◽  
Jianguo Wang ◽  
...  

p38-Regulated/activated protein kinase (PRAK) plays a critical role in modulating cellular survival and biological function. However, the function of PRAK in the regulation of myocardial ischemic injury remains unknown. This study is aimed at determining the function of PRAK in modulating myocardial ischemia-reperfusion injury and myocardial remodeling following myocardial infarction. Hearts were isolated from adult male homozygous PRAK−/− and wild-type mice and subjected to global ischemia-reperfusion injury in Langendorff isolated heart perfusion. PRAK−/− mice mitigated postischemic ventricular functional recovery and decreased coronary effluent. Moreover, the infarct size in the perfused heart was significantly increased by deletion of PRAK. Western blot showed that deletion of PRAK decreased the phosphorylation of ERK1/2. Furthermore, the effect of deletion of PRAK on myocardial function and remodeling was also examined on infarcted mice in which the left anterior descending artery was ligated. Echocardiography indicated that PRAK−/− mice had accelerated left ventricular systolic dysfunction, which was associated with increased hypertrophy in the infarcted area. Deletion of PRAK augmented interstitial fibrosis and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL)-positive myocytes. Furthermore, immunostaining analysis shows that CD31-postive vascular density and α-smooth muscle actin capillary staining decreased significantly in PRAK−/− mice. These results indicate that deletion of PRAK enhances susceptibility to myocardial ischemia-reperfusion injury, attenuates cardiac performance and angiogenesis, and increases interstitial fibrosis and apoptosis in the infarcted hearts.


Sign in / Sign up

Export Citation Format

Share Document