A novel Danshensu derivative confers cardioprotection via PI3K/Akt and Nrf2 pathways

Zhang

et al. 2017

Cell Physiol Biochem

Background/Aims: Myocardial infarction (MI) is a leading cause of morbidity and mortality. Here, we sought to explore the potential role and underlying mechanism of miR-145 in MI. Methods: H9c2 cells were cultured under persistent hypoxia to simulate MI. The hypoxia-induced injury was assessed on the basis of cell viability, migration, invasion and apoptosis. The expression of miR-145 was evaluated by qRT-PCR and the influence of aberrantly expressed miR-145 on H9c2 cells under hypoxia was also estimated. Utilizing bioinformatics methods, the target genes of miR-145 were verified by luciferase reporter assay. Then, effects of abnormally expressed target gene on miR-145 silenced H9c2 cells were assessed. Finally, the phosphorylation levels of key kinases in the phosphatidylinositol-3-kinase (PI3K)/AKT and the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways were detected by Western blot analysis. Results: Hypoxia remarkably lowered viability, migration and invasion but promoted cell apoptosis. Meantime, the miR-145 level was up-regulated in H9c2 cells under hypoxia. Following experiments suggested that hypoxia-induced injury was exacerbated by miR-145 overexpression while was alleviated by miR-145 silence. Rac1 was predicted and further validated to be a target gene of miR-145. The influence of miR-145 silencing on H9c2 cells under hypoxia could be reversed by down-regulation of Rac1. Additionally, the phosphorylation levels of PI3K, AKT, MAPK and ERK were all elevated in miR-145 silenced cells and these alterations were reversed by down-regulation of Rac1. Conclusion: miR-145 silencing could protect H9c2 cells against hypoxia-induced injury by targeting Rac1, in which PI3K/AKT and MAPK/ERK pathways might be involved.

Section: Methodsmentioning

confidence: 99%

MicroRNA-145 Aggravates Hypoxia-Induced Injury by Targeting Rac1 in H9c2 Cells

Zhang

et al. 2017

Cell Physiol Biochem

Biological & Pharmaceutical Bulletin

“…1) was found to reduce infarct size in a rat model of myocardial ischemia. 9) However, ADTM was quickly hydrolyzed by carboxylesterase and its half-life was too short in vivo. 10) In addition, ADTM has poor water solubility.…”

mentioning

confidence: 99%

A Novel Danshensu-Tetramethylpyrazine Conjugate DT-010 Provides Cardioprotection through the PGC-1α/Nrf2/HO-1 Pathway

Zhang¹,

Hu²,

Luo³

et al. 2017

Self Cite

In this study, we investigated the cardioprotective mechanisms of action of DT-010, a novel danshensutetramethylpyrazine conjugate. DT-010 significantly preserved cell viability and suppressed cell apoptosis in H9c2 cells injured by tert-butylhydroperoxide (t-BHP), iodoacetic acid (IAA) and hypoxia-reoxygenation. In addition, DT-010 pre-treatment reduced the intracellular level of free radicals including superoxide anion (·O 2 ), hydroxyl radical (·OH) and peroxynitrite anion (ONOO ) after t-BHP exposure. Moreover, DT-010 up-regulated the protein expression of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) and nuclear factor-E2-related factor 2 (Nrf2) as well as mitochondrial transcription factor A (Tfam) and heme oxygenase-1 (HO-1) in H9c2 cells. DT-010 also triggered Nrf2 nuclear translocation. In a rat myocardial ischemia-reperfusion model, DT-010 significantly alleviated myocardial infarction. The results indicated that DT-010 may be a promising candidate for the treatment of cardiovascular diseases, particularly myocardial ischemia and reperfusion injury.Key words Danshensu derivative; oxidative stress; apoptosis; myocardial ischemia reperfusion injury; peroxisome proliferator-activated receptor gamma coactivator 1 alpha/nuclear factor-E2-related factor 2/heme oxygenase-1 (PGC-1α/Nrf2/HO-1) pathway Myocardial ischemia is a primary cause of sudden death worldwide. Myocardial ischemia results from a decreased blood flow to the heart, preventing the heart from receiving adequate supply of energy. The reduced blood flow is usually caused by a partial or complete blockade of the arteries. Traditional treatments focus on restoring blood supply, such as by pass-graft surgery, dilation of coronary artery and coronary thrombolysis, and etc. 1) Although restoration of blood flow to the ischemic heart tissues is important, it is not adequate because myocardial ischemic damage is progressively developed following reperfusion due to an over-production of a large number of biospecies. 2,3) Compelling evidence demonstrated that free radicals generated during ischemia and reperfusion play pivotal roles in myocardial apoptosis. Free radical scavengers can effectively inhibit myocardial apoptosis. The previous studies have demonstrated that agents that combine anti-thrombolytic and anti-oxidative activities showed promising therapeutic efficacy in the treatment of myocardial ischemia. 4,5) In China, many traditional herbs have been used to prevent and treat myocardial ischemia. Among them are Salvia miltiorrhiza (Danshen) and Ligusticum wallichii (Chuanxiong). As the major active ingredients, (3-(3,4-dihydroxyphenyl) lactic acid) (Danshensu, DSS, Fig. 1) isolated from Danshen and tetramethylpyrazine (TMP, Fig. 1) isolated from Chuanxiong have a variety of biological activities. They lyse blood clot, dilate coronary arteries, inhibit platelet aggregation, scavenge free radicals, improve microcirculation and have anti-inflammatory properties. 6,7) Both of them are widely used in clinic for treatm...

“…The Keap-1/Nrf-2 system has been recognized as a cellular endogenous defense mechanism against oxidative stress (4,12). However, it was unknown whether the Keap-1/Nrf-2 signaling pathway influenced AD-MSCs viability, function, or ability to withstand ROS damage under stressful conditions.…”

Section: Discussionmentioning

confidence: 99%

Activation of Liver X Receptor Improves Viability of Adipose-Derived Mesenchymal Stem Cells to Attenuate Myocardial Ischemia Injury Through TLR4/NF-κB and Keap-1/Nrf-2 Signaling Pathways

Antioxidants & Redox Signaling

C²,

Cheng³

et al. 2014

Aims: Clinical application of cellular therapy for cardiac regeneration is significantly hampered by the low retention of engrafted cells, mainly attributable to the poor microenvironment dominated by inflammation and oxidative stress in the host's infarcted myocardium. This study aims at investigating whether liver X receptor (LXR) agonist T0901317 will improve survival of adipose-derived mesenchymal stem cells (AD-MSCs) after transplantation into infarcted hearts. Results: Noninvasive in vivo bioluminescence imaging and histological staining showed that LXR agonist T0901317 improved the retention and survival of intramyocardially injected AD-MSCs. Moreover, combined therapy of LXR agonist and AD-MSCs inhibited host cardiomyocyte apoptosis, reduced fibrosis, and improved cardiac function, while it concomitantly decreased inflammatory cytokines (e.g., tumor necrosis factor-a and interleukin-6) and increased growth factor (e.g., vascular endothelial growth factor and basic fibroblast growth factor) expression in infarct myocardium. To reveal possible mechanisms, AD-MSCs were subjected to hypoxia/serum deprivation (H/SD) injury to simulate ischemic conditions in vivo. The LXR agonist (10 -7 mM) improved AD-MSC survival under H/SD condition. Western blot revealed that the LXR agonist reduced TLR4, TRAF-6, and MyD88 protein expression, inhibited IjBa phosphorylation and NF-jB-p65 nuclear translocation, which resulted in accelerated Keap-1 protein degradation, enhanced Nrf-2 nuclear translocation, and increased HO-1 protein expression. Innovation and Conclusion: LXR agonist can enhance the functional survival of transplanted AD-MSCs in infarcted myocardium, at least partially, via modulation of the TLR4/NF-jB and Keap-1/Nrf-2 signaling pathways. Moreover, combined therapy of LXR agonist and AD-MSCs has a synergetic effect on cardiac repair and functional improvement after infarction. Antioxid. Redox Signal. 21, 2543-2557.