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Ginkgolide K protects the heart against endoplasmic reticulum stress injury by activating the inositol-requiring enzyme 1?/X box-binding protein-1 pathway.

ABSTRACT:

Background and purpose

Endoplasmic reticulum (ER) stress is increasingly recognized as an important causal factor of many diseases. Targeting ER stress has now emerged as a new therapeutic strategy for treating cardiovascular diseases. Here, we investigated the effects and underlying mechanism of ginkgolide K (1,10-dihydroxy-3,14-didehydroginkgolide, GK) on cardiac ER stress.

Experimental approach

Cell death, apoptosis and ER stress-related signalling pathways were measured in cultured neonatal rat cardiomyocytes, treated with the ER stress inducers tunicamycin, hydrogen peroxide and thapsigargin. Acute myocardial infarction was established using left coronary artery occlusion in mice, and infarct size was measured by triphenyltetrazolium chloride staining. Echocardiography was used to assess heart function and transmission electron microscopy for evaluating ER expansion.

Key results

Ginkgolide K (GK) significantly decreased ER stress-induced cell death in both in vitro and in vivo models. In ischaemic injured mice, GK treatment reduced infarct size, rescued heart dysfunction and ameliorated ER dilation. Mechanistic studies revealed that the beneficial effects of GK occurred through enhancement of inositol-requiring enzyme 1? (IRE1?)/X box-binding protein-1 (XBP1) activity, which in turn led to increased ER-associated degradation-mediated clearance of misfolded proteins and autophagy. In addition, GK was also able to partly repress the pro-apoptotic action of regulated IRE1-dependent decay and JNK pathway.

Conclusions and implications

In conclusion, GK acts through selective activation of the IRE1?/XBP1 pathway to limit ER stress injury. GK is revealed as a promising therapeutic agent to ameliorate ER stress for treating cardiovascular diseases.

SUBMITTER: Wang S

PROVIDER: S-EPMC4945765 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature

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Ginkgolide K protects the heart against endoplasmic reticulum stress injury by activating the inositol-requiring enzyme 1α/X box-binding protein-1 pathway.

Wang Shoubao S Wang Zhenzhong Z Fan Qiru Q Guo Jing J Galli Gina G Du Guanhua G Wang Xin X Xiao Wei W

British journal of pharmacology 20160708 15

<h4>Background and purpose</h4>Endoplasmic reticulum (ER) stress is increasingly recognized as an important causal factor of many diseases. Targeting ER stress has now emerged as a new therapeutic strategy for treating cardiovascular diseases. Here, we investigated the effects and underlying mechanism of ginkgolide K (1,10-dihydroxy-3,14-didehydroginkgolide, GK) on cardiac ER stress.<h4>Experimental approach</h4>Cell death, apoptosis and ER stress-related signalling pathways were measured in cul ...[more]

PMID: 27186946

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