Hydroxysafflor Yellow A Ameliorates Myocardial Ischemia/Reperfusion Injury by Suppressing Calcium Overload and Apoptosis.

Jingxue Ye,Jianhua Fu,Guibo Sun,Xiaobo Sun,Min Wang,Ruiying Wang,Qiong Zhang,Qingping Feng

doi:10.1155/2021/6643615

Abstract

Myocardial ischemia/reperfusion injury (MI/RI) is an urgent problem with a great impact on health globally. However, its pathological mechanisms have not been fully elucidated. Hydroxysafflor yellow A (HSYA) has a protective effect against MI/RI. This study is aimed at further clarifying the relationship between HSYA cardioprotection and calcium overload as well as the underlying mechanisms. We verified the protective effect of HSYA on neonatal rat primary cardiomyocytes (NPCMs) and human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from hypoxia-reoxygenation (HR) injury. To explore the cardioprotective mechanism of HSYA, we employed calcium fluorescence, TUNEL assay, JC-1 staining, and western blotting. Finally, cardio-ECR and patch-clamp experiments were used to explain the regulation of L-type calcium channels (LTCC) in cardioprotection mediated by HSYA. The results showed that HSYA reduced the levels of myocardial enzymes and protected NPCMs from HR injury. HSYA also restored the contractile function of hiPSC-CMs and field potential signal abnormalities caused by HR and exerted a protective effect on cardiac function. Further, we demonstrated that HSYA protects cardiomyocytes from HR injury by decreasing mitochondrial membrane potential and inhibiting apoptosis and calcium overload. Patch-clamp results revealed that MI/RI caused a sharp increase in calcium currents, which was inhibited by pretreatment with HSYA. Furthermore, we found that HSYA restored contraction amplitude, beat rate, and field potential duration of hiPSC-CMs, which were disrupted by the LTCC agonist Bay-K8644. Patch-clamp experiments also showed that HSYA inhibits Bay-K8644-induced calcium current, with an effect similar to that of the LTCC inhibitor nisoldipine. Therefore, our data suggest that HSYA targets LTCC to inhibit calcium overload and apoptosis of cardiomyocytes, thereby exerting a cardioprotective effect and reducing MI/RI injury.

Highlights

Ischemic heart disease is associated with high mortality rates and disability burden worldwide [1]
CCK-8 indicated that Hydroxysafflor yellow A (HSYA) (2.5, 5, and 10 μM) dose-dependently attenuated myocardial damage caused by HR (Figure 1(a))
We found that HR in neonatal rat primary cardiomyocytes (NPCMs) led to an increase in lactate dehydrogenase (LDH), aspartate transaminase (AST), and creatine kinase-MB (CK-MB) levels, which was attenuated by pretreatment with HSYA (2.5, 5, and 10 μM) in a dose-dependent manner (Figures 1(b)–1(d)), consistent with the results of the Cell Counting Kit-8 (CCK8) assay

Summary

Introduction

Ischemic heart disease is associated with high mortality rates and disability burden worldwide [1]. MI/RI mainly involves oxidative stress, calcium overload, inflammation, and energy metabolism disorders [3]. LTCC are important to transport extracellular Ca2+ into cardiomyocytes, and disorders of their structure or function can cause an imbalance in intracellular calcium homeostasis [8]. Proven protective mechanisms mainly include inhibition of apoptosis, inflammation, mitochondrial dysfunction, and activation of autophagy [14, 15]. HSYA can improve diabetic cardiac insufficiency by regulating calcium homeostasis in rats [18]. Our research team has previously shown that HSYA protects against MI/RI in rats and HR in H9C2 cardiomyocytes. We used neonatal rat primary cardiomyocytes (NPCMs) and human-induced pluripotent stem cellderived cardiomyocytes (hiPSC-CMs) to further demonstrate that HSYA exerts a protective effect against MI/RI by regulating LTCC

Materials and Methods

Results

Discussion

Conclusions

Conflicts of Interest