Sevoflurane postconditioning protects the myocardium against ischemia/reperfusion injury via activation of the JAK2–STAT3 pathway

Yang

et al. 2018

Cell Physiol Biochem

Background/Aims: Total saponins of Aralia elata (Miq) Seem (AS) from the Chinese traditional herb Long ya Aralia chinensis L. reportedly provide cardioprotective effects, but the exact mechanisms require further study. Previous studies have showed that myocardial ischemia/ reperfusion injury (MIRI) was related to calcium homeostasis imbalance and endoplasmic reticulum stress (ERS). Thus, this study aimed to demonstrate protective effects of AS on MIRI. Methods: After administrating AS for 5 days, the left anterior descending artery coronary artery of Sprague-Dawley (SD) rats was ligated for 30 min. After 48 h of reperfusion, haemodynamics, Evans blue/ 2,3,5-triphenyltetrazolium chloride (TTC) staining, hematoxylin-eosin (HE) staining, masson staining and the levels of lactate dehydrogenase (LDH) and creatine kinase (CK), superoxide dismutase (SOD), malondialdehyde (MDA) were detected to assess MIRI. ATPase activity and Western Blot were used to study the mechanisms. Results: Compared with IR group, AS treatment groups could significantly reduce myocardial infarct size; improve myocardial pathologic progress; decrease content of LDH, CK, and MDA; increase content of SOD; and restore the activities of Ca²⁺-Mg²⁺-ATPase, Na⁺-K⁺-ATPase, sarcoplasmic reticulum Ca²⁺-ATPases (SERCA), and calcineurin (CaN). AS treatment groups also significantly up-regulated the expression of GRP78, C/EBP homologous protein (CHOP), and Bax, and down-regulated the expression of Bcl-2, all similar to the effects of ERS. Conclusion: These findings illustrated that AS could prevent myocardial ischemia/reperfusion injury and reduce calcium homeostasis imbalance and ERS-related apoptosis.

Section: Discussionmentioning

confidence: 69%

Total Saponins of Aralia Elata (Miq) Seem Alleviate Calcium Homeostasis Imbalance and Endoplasmic Reticulum Stress-Related Apoptosis Induced by Myocardial Ischemia/Reperfusion Injury

Yang

et al. 2018

Cell Physiol Biochem

“…Apart from their localization at the mitochondria and the cytoplasm, Bcl-2 and Bax proteins are also constitutionally present on the sarcolemma of the cardiomyocytes [39]. Currently, the anti-apoptotic role of cytosolic Bcl-2 in postconditioning cardioprotection has been well investigated in both in vivo and in vitro [38, 40], but little is known regarding the role of Bcl-2 family members in the sarcolemma and mitochondria. Here we examined the effects of HPC on Bcl-2 family proteins, especially in the sarcolemmal and mitochondrial fractions.…”

Section: Discussionmentioning

confidence: 99%

“…Accumulating studies have shown that the pro-apoptotic (Bax) and anti-apoptotic (Bcl-2) proteins of the Bcl-2 family play a pivotal role in this apoptotic process [38] The balance between pro- and anti-apoptotic members of the Bcl-2 family is critical in determining cell fate. Apart from their localization at the mitochondria and the cytoplasm, Bcl-2 and Bax proteins are also constitutionally present on the sarcolemma of the cardiomyocytes [39].…”

Section: Discussionmentioning

confidence: 99%

Novel Functional Role of Heat Shock Protein 90 in Mitochondrial Connexin 43-Mediated Hypoxic Postconditioning

Huang

et al. 2017

Cell Physiol Biochem

Background/Aims: Previous studies have shown that heat shock protein 90 (HSP90)-mediated mitochondrial import of connexin 43 (Cx43) is critical in preconditioning cardioprotection. The present study was designed to test whether postconditioning has the same effect as preconditioning in promoting Cx43 translocation to mitochondria and whether mitochondrial HSP90 modulates this effect. Methods: Cellular models of hypoxic postconditioning (HPC) from rat heart-derived H9c2 cells and neonatal rat cardiomyocytes were employed. The effects of HPC on cardiomyocytes apoptosis were examined by flow cytometry and Hoechst 33342 fluorescent staining. Reactive oxidative species (ROS) production was assessed with the peroxide-sensitive fluorescent probe 2′,7′-dichlorofluorescin in diacetate (DCFH-DA). The anti- and pro-apoptotic markers Bcl-2 and Bax, HSP90 and Cx43 protein levels were studied by Western blot analysis in total cell homogenate and sarcolemmal and mitochondrial fractions. The effects on HPC of the HSP90 inhibitor geldanamycin (GA), ROS scavengers superoxide dismutase (SOD) and catalase (CAT), and small interfering RNA (siRNA) targeting Cx43 and HSP90 were also investigated. Results: HPC significantly reduced hypoxia/reoxygenation (H/R)-induced cardiomyocyte apoptosis. These beneficial effects were accompanied by an increase in Bcl-2 levels and a decrease in Bax levels in both sarcolemmal and mitochondrial fractions. HPC with siRNA targeting Cx43 or the ROS scavengers SOD plus CAT significantly prevented ROS generation and HPC cardioprotection, but HPC with either SOD or CAT did not. These data strongly supported the involvement of Cx43 in HPC cardioprotection, likely via modulation of the ROS balance which plays a central role in HPC protection. Furthermore, HPC increased total and mitochondrial levels of HSP90 and the mitochondria-to-sarcolemma ratio of Cx43; blocking the function of HSP90 with the HSP90 inhibitor geldanamycin (GA) or siRNA targeting HSP90 prevented the protection of HPC and the HPC-induced association of Cx43, indicating that mitochondrial HSP90 was important for mitochondrial translocation of Cx43 during HPC. Conclusion: Mitochondrial HSP90 played a central role in HPC cardioprotection, and its activity was linked to the mitochondrial targeting of Cx43, the activation of which triggered ROS signaling and the subsequent reduction of redox stress. Consequently, its target gene, Bcl-2, was upregulated, and proapoptotic Bax was inhibited in the sarcolemma and mitochondria, ultimately attenuating H/R-induced cardiomyocyte apoptosis. These data reveal a novel mechanism of HPC protection.

“…Sevoflurane is an inhaled volatile anaesthetic that is widely used in clinical and basic research due to its pharmacological characteristics such as induction of stability and rapid recovery. Many studies have confirmed that sevoflurane postconditioning (SPostC) can alleviate ischemia-reperfusion injury effectively in healthy myocardium (Yu et al, 2015;Wu et al, 2017b;Qiao et al, 2019). However, in the diabetic state, myocardial protection of SPostC is weakened (Drenger et al, 2011;Tai et al, 2012;Gao et al, 2016), and the specific mechanism remains unclear.…”

Section: Introductionmentioning

confidence: 99%

Deferoxamine Treatment Combined With Sevoflurane Postconditioning Attenuates Myocardial Ischemia-Reperfusion Injury by Restoring HIF-1/BNIP3-Mediated Mitochondrial Autophagy in GK Rats

Long

Xie

et al. 2020

Front. Pharmacol.

Self Cite

Mitochondrial autophagy is involved in myocardial protection of sevoflurane postconditioning (SPostC) and in diabetic state this protective effect is weakened due to impaired HIF-1 signaling pathway. Previous studies have proved that deferoxamine (DFO) could activate impaired HIF-1a in diabetic state to restore the cardioprotective of sevoflurane, while the specific mechanism is unclear. This study aims to investigate whether HIF-1/BNIP3-mediated mitochondrial autophagy is involved in the restoration of sevoflurane postconditioning cardioprotection in diabetic state. Ischemia/reperfusion (I/R) model was established by ligating the anterior descending coronary artery and sevoflurane was administered at the first 15 min of reperfusion. Myocardial infarct size, mitochondrial ultrastructure and autophagosome, ATP content, mitochondrial membrane potential, ROS production, HIF-1a, BNIP3, LC3B-II, Beclin-1, P62, LAMP2 protein expression were detected 2 h after reperfusion, and cardiac function was evaluated by ultrasound at 24 h after reperfusion. Our results showed that with DFO treatment, SPostC up-regulated the expression of HIF-1a and BNIP3, thus reduced the expression of key autophagy proteins LC3B-II, Beclin-1, p62, and increased the expression of LAMP2. Furthermore, it reduced the accumulation of autophagosomes and ROS production, increased the content of ATP, and stabilized the membrane potential. Finally, the myocardial infarction size was reduced and cardiac function was improved. Taken together, DFO treatment combined with SPostC could alleviate myocardial ischemia reperfusion injury in diabetic rats by restoring and promoting HIF-1/BNIP3-mediated mitochondrial autophagy.