Apelin protects sarcoplasmic reticulum function and cardiac performance in ischaemia-reperfusion by attenuating oxidation of sarcoplasmic reticulum Ca2+-ATPase and ryanodine receptor

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: 99%

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

“…Excessive ROS production and calcium overload are the two proposed mechanisms of cardiac dysfunction in IR injury . ROS overproduction causes damage to the cell membranes in rat hearts, subsequently causes cell membrane lipid peroxidation and results in myocardial structural failure . In this study, we investigated the effects of Araloside C on oxidative stress in I/R hearts.…”

Section: Discussionmentioning

confidence: 99%

Protective effects of Araloside C against myocardial ischaemia/reperfusion injury: potential involvement of heat shock protein 90

J Cellular Molecular Medi

Tian

et al. 2017

The present study was designed to investigate whether Araloside C, one of the major triterpenoid compounds isolated from Aralia elata known to be cardioprotective, can improve heart function following ischaemia/reperfusion (I/R) injury and elucidate its underlying mechanisms. We observed that Araloside C concentration‐dependently improved cardiac function and depressed oxidative stress induced by I/R. Similar protection was confirmed in isolated cardiomyocytes characterized by maintaining Ca2+ transients and cell shortening against I/R. Moreover, the potential targets of Araloside C were predicted using the DDI‐CPI server and Discovery Studio software. Molecular docking analysis revealed that Araloside C could be stably docked into the ATP/ADP‐binding domain of the heat shock protein 90 (Hsp90) protein via the formation of hydrogen bonds. The binding affinity of Hsp90 to Araloside C was detected using nanopore optical interferometry and yielded KD values of 29 μM. Araloside C also up‐regulated the expression levels of Hsp90 and improved cell viability in hypoxia/reoxygenation‐treated H9c2 cardiomyocytes, whereas the addition of 17‐AAG, a pharmacologic inhibitor of Hsp90, attenuated Araloside C‐induced cardioprotective effect. These findings reveal that Araloside C can efficiently attenuate myocardial I/R injury by reducing I/R‐induced oxidative stress and [Ca2+]i overload, which was possibly related to its binding to the Hsp90 protein.

“…Animals were anesthetized by injecting sodium pentobarbital (50 mg/kg intraperitoneally). Single ventricular myocytes were isolated as described [ 18 ].…”

Section: Methodsmentioning

confidence: 99%

High Uric Acid Induces Insulin Resistance in Cardiomyocytes In Vitro and In Vivo

Yang

Huang

et al. 2016

PLoS ONE

Clinical studies have shown hyperuricemia strongly associated with insulin resistance as well as cardiovascular disease. Direct evidence of how high uric acid (HUA) affects insulin resistance in cardiomyocytes, but the pathological mechanism of HUA associated with cardiovascular disease remains to be clarified. We aimed to examine the effect of HUA on insulin sensitivity in cardiomyocytes and on insulin resistance in hyperuricemic mouse model. We exposed primary cardiomyocytes and a rat cardiomyocyte cell line, H9c2 cardiomyocytes, to HUA, then quantified glucose uptake with a fluorescent glucose analog, 2-NBDG, after insulin challenge and detected reactive oxygen species (ROS) production. Western blot analysis was used to examine the levels of insulin receptor (IR), phosphorylated insulin receptor substrate 1 (IRS1, Ser307) and phospho-Akt (Ser473). We monitored the impact of HUA on insulin resistance, insulin signaling and IR, phospho-IRS1 (Ser307) and phospho-Akt levels in myocardial tissue of an acute hyperuricemia mouse model established by potassium oxonate treatment. HUA inhibited insulin-induced glucose uptake in H9c2 and primary cardiomyocytes. It increased ROS production; pretreatment with N-acetyl-L-cysteine (NAC), a ROS scavenger, reversed HUA-inhibited glucose uptake induced by insulin. HUA exposure directly increased the phospho-IRS1 (Ser307) response to insulin and inhibited that of phospho-Akt in H9C2 cardiomyocytes, which was blocked by NAC. Furthermore, the acute hyperuricemic mice model showed impaired glucose tolerance and insulin tolerance accompanied by increased phospho-IRS1 (Ser307) and inhibited phospho-Akt response to insulin in myocardial tissues. HUA inhibited insulin signaling and induced insulin resistance in cardiomyocytes in vitro and in vivo, which is a novel potential mechanism of hyperuricemic-related cardiovascular disease.