Inhibition of miR-153 ameliorates ischemia/reperfusion-induced cardiomyocytes apoptosis by regulating Nrf2/HO-1 signaling in rats

Effect of CASC15 on apoptosis and oxidative stress of cardiomyocytes after hypoxia/reperfusion injury

INTRODUCTION AND OBJECTIVES

The increasing incidence of ischemic heart disease is a serious threat to human health. Increased CASC15, a long non-coding RNA, has been shown to adversely affect cardiac muscle. The objective of this paper was to explore the effect of CASC15 on a cell model of myocardial infarction and its possible mechanism.

METHODS

H9c2 cells were selected to establish the myocardial infarction model through hypoxia/reoxygenation (H/R) treatment. The expression of CASC15 was attenuated by cell transfection in vitro. The level of CASC15 was detected by RT-qPCR. Cell viability was detected by CCK-8 assay, and cell apoptosis was assessed by flow cytometry. The content of MDA and the activity of SOD and GSH-Px were measured by ELISA. Luciferase reporter gene assay was used to determine the relationship between CASC15 and miRNA.

RESULTS

CASC15 expression was increased in H/R-treated H9c2 cells. Overexpression of CASC15 adversely affected cell viability and promoted H/R-induced oxidative stress. Inhibition of CASC15 promoted cell viability and suppressed cell apoptosis and oxidative stress damage. Additionally, luciferase reporter gene assay confirmed the targeting relationship between CASC15 and miR-542-3p, and attenuating CASC15 expression enhanced the level of miR-542-3p. Reduction of miR-542-3p weakened the viability of the H/R cell model, increased apoptosis, and enhanced oxidative stress damage.

CONCLUSION

This study suggests that overexpression of CASC15 may inhibit the viability of H9c2 cells, promote apoptosis and induce oxidative stress through targeted regulation of miR-542-3p expression.

Nrf2 for a key member of redox regulation: A novel insight against myocardial ischemia and reperfusion injuries

Nuclear factor erythroid-2 related factor 2 (Nrf2), a nuclear transcription factor, modulates genes responsible for antioxidant responses against toxic and oxidative stress to maintain redox homeostasis and participates in varieties of cellular processes such as metabolism and inflammation during myocardial ischemia and reperfusion injuries (MIRI). The accumulation of reactive oxygen species (ROS) from damaged mitochondria, xanthine oxidase, NADPH oxidases, and inflammation contributes to depraved myocardial ischemia and reperfusion injuries. Considering that Nrf2 played crucial roles in antagonizing oxidative stress, it is reasonable to delve into the up or down-regulated molecular mechanisms of Nrf2 in the progression of MIRI to provide the possibility of new therapeutic medicine targeting Nrf2 in cardiovascular diseases. This review systematically describes the generation of ROS, the regulatory metabolisms of Nrf2 as well as several natural or synthetic compounds activating Nrf2 during MIRI, which might provide novel insights for the anti-oxidative stress and original ideas targeting Nrf2 for the prevention and treatment in cardiovascular diseases.

MicroRNA-214-3p protects against myocardial ischemia-reperfusion injury by targeting demethylase lysine demethylase 3A

Objective

Many studies have explored the roles of microRNAs (miRs) in myocardial ischemia/reperfusion injury (MI/RI), while the function of miR-214-3p in MI/RI remained obscure. This study aims to unravel the regulatory mechanism of miR-214-3p in MI/RI via targeting histone demethylase lysine demethylase 3A (KDM3A).

Methods

MI/RI rat model was established by ligating the left anterior descending coronary artery. MiR-214-3p and KDM3A expression in myocardial tissues of MI/RI rats was examined. Then, the serum oxidative stress factors, inflammatory factors, pathological changes of myocardial tissues, cardiomyocyte apoptosis, and fibrosis of myocardial tissues were detected in MI/RI rats intervening with miR-214-3p or KDM3A expression. The targeting relation between miR-214-3p and KDM3A was validated.

Results

MiR-214-3p was low-expressed while KDM3A was high-expressed in MI/RI rat model. Up-regulated miR-214-3p or down-regulated KDM3A protected against MI/RI via mitigating serum oxidative response, reducing the levels of inflammatory factors, alleviating the pathological changes of myocardial tissues, and decreasing cardiomyocyte apoptosis and fibrosis of myocardial tissue. KDM3A amplification reversed the therapeutic effects of elevated miR-214-3p on MI/RI. KDM3A was targeted by miR-214-3p.

Conclusion

miR-214-3p hinders cardiomyocyte apoptosis and myocardial injury in MI/RI rats via regulating KDM3A. Thus, miR-214-3p may function as a potential candidate for MI/RI treatment.

Acacetin alleviates myocardial ischaemia/reperfusion injury by inhibiting oxidative stress and apoptosis via the Nrf-2/HO-1 pathway

CONTEXT

Acacetin is a natural source of flavonoids with anti-inflammatory and antioxidant effects.

OBJECTIVE

This study determines acacetin's protective effect and mechanism on myocardial ischaemia/reperfusion (I/R) injury.

MATERIALS AND METHODS

Sprague-Dawley rats were divided into sham and I/R injury and treatment with acacetin. Acacetin (10 mg/kg) was subcutaneously injected for 7 days. ECG and echocardiography were conducted to determine arrhythmia and heart function. The pathological characters of the heart were determined with triphenyl tetrazolium chloride staining, Haematoxylin & Eosin staining, and Masson staining. Expression of proteins in infarct tissues was examined with western blots.

RESULTS

Administrated with acacetin in I/R rats significantly reduced the arrhythmia score from 4.90 to 2.50 and the reperfusion arrhythmia score from 3.79 to 1.82 in the vehicle or the acacetin group, respectively. LVEF was improved from 33.5% in the I/R group to 43.7% in the acacetin group, LVFS was increased from 16.4% to 24.5%, LVIDs was decreased from 6.5 to 5.3 mm. The inflammatory cell infiltration, myocardial fibrosis, and collagen 1 and 3 were reduced by acacetin. Acacetin promoted SOD and decreased MDA. In myocardial tissues, the expression level of TLR4 and IL-6 were restrained, and IL-10 was promoted. Apoptotic protein Bax was suppressed, and anti-apoptotic protein Bcl-2 was promoted in the acacetin group. Interestingly, the transcription factor Nrf-2/HO-1 pathway was also reversed by acacetin.

DISCUSSION AND CONCLUSION

Our findings indicated that acacetin has a potential therapeutic effect in clinical application on treating I/R-induced heart injury.

The heart as a target for deltamethrin toxicity: Inhibition of Nrf2/HO-1 pathway induces oxidative stress and results in inflammation and apoptosis

As a synthetic pyrethroid pesticide, deltamethrin (DLM) is widely employed in veterinary medicine and farming, and DLM-triggered oxidative stress largely causes serious harm to the organism. It is well-known that nuclear factor erythroid-2-related factor 2/heme oxygenase-1 (Nrf2/HO-1), a pivotal endogenous anti-oxidative pathway, acts on inhibiting oxidative stress-induced cell injury under the activated state. The purpose of this research was to observe the impact and molecular mechanism of DLM on inflammation and apoptosis in quail cardiomyocytes based on the Nrf2/HO-1 signaling route. In this research, quails were established as a cardiac injury model through gastric infusion of various doses of DLM (0, 15, 30, and 45 mg/kg b. w.) for 12 weeks. Our results showed that DLM could induced cardiomyocyte injury in a dose-dependent manner though weakening antioxidant defense via down-regulating Nrf2 and its downstream protein HO-1. Furthermore, DLM stimulation induced apoptosis in quail heart by decreasing the protein expressions of B-cell lymphoma-extra large and B-cell lymphoma gene 2 (Bcl-2), as well as increasing P53, caspase 3, and Bcl-2-associated X protein levels. Meanwhile, relative levels of nuclear factor-kappa B and interleukin-1β in quail hearts were up-regulated under DLM intervention progressively. Collectively, our study demonstrates that chronic exposure to DLM can induce quail cardiomyocyte inflammation and apoptosis by mediating Nrf2/HO-1 signaling pathway-related oxidative stress.

The activation of SIRT3 by dexmedetomidine mitigates limb ischemia-reperfusion-induced lung injury

Background

The lung is one of the most sensitive organs, and is vulnerable to injury caused by limb ischemia-reperfusion (LIR). Dexmedetomidine, an anesthetic adjunct, has been shown to have therapeutic effects on lung injury secondary to LIR. This study aimed to investigate the role of dexmedetomidine in ameliorating LIR-induced lung injury in a mouse model of bilateral hind LIR.

Methods

In this study, 75 mice were randomly divided into 5 groups to prepare the LIR model. After the model was established, arterial blood was extracted for blood gas analysis. The pathological changes of lung tissue, lung wet/dry weight ratio, arterial blood gas analysis, detection of myeloperoxidase (MPO) activity, the content of reactive oxygen species (ROS), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in oxidative stress indexes, mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) content and cytochrome c content were measured, and the relative protein expression levels of sirtuin-3 (SIRT3) and apoptosis factor Bcl-2 related X protein (Bax), B-cell Lymphoma 2 (Bcl-2), cleaved caspase 3, and nuclear factor erythroid 2-related factor 2 (Nrf2) and cytoplasmic heme oxygenase-1 (HO-1).

Results

Pretreatment with dexmedetomidine dramatically ameliorated LIR-induced lung injury, the wet/dry weight ratio, the arterial blood gas parameters, and enhanced SIRT3 expression. Moreover, dexmedetomidine significantly inhibits ROS and MDA level and restores antioxidant enzyme activities (SOD, GSH-Px). Of note, dexmedetomidine suppressed LIR-induced lung tissue apoptosis by modulating apoptosis-associated protein such as Bax, Bcl-2, and cleaved caspase 3. Moreover, dexmedetomidine inhibited the LIR-induced decreases in MMP, ATP levels, and the release of cytochrome c of LIR to maintain mitochondrial function. Latest study has shown that activating Nrf2 could promote SIRT3 expression to alleviate IR injury. Intriguingly, dexmedetomidine could facilitate nuclear Nrf2 and cytoplasmic HO-1 expression.

Conclusions

Our findings suggest that dexmedetomidine protects against LIR-induced lung injury by inhibiting the oxidative response, mitochondrial dysfunction and apoptosis. The mechanism appears to be at least partly mediated through the upregulation of SIRT3 expression.

miR-3587 Inhibitor Attenuates Ferroptosis Following Renal Ischemia-Reperfusion Through HO-1

Renal ischemia-reperfusion (IR) is frequently observed in patients who are critically ill, yet there are no reliable or effective approaches for the treatment of this condition. Ferroptosis, a form of programmed cell death, is regulated by key genes such as glutathione peroxidase 4 (GPX4) and heme oxygenase-1 (HMOX1) and participates in the injury of renal tubular epithelial cells during IR. This study aimed to investigate the miRNA-mRNA regulatory networks involved in ferroptosis following renal IR. Using bioinformatics analysis, HMOX1 was found to be significantly upregulated during the early stages of renal IR injury, and microRNA-3587 (miR-3587) was identified as a putative regulator of HMOX1. When a miR-3587 inhibitor was applied in a hypoxia-reoxygenation (HR) model system using renal tubular epithelial cells, HO-1 protein (encoded by HMOX1) expression was significantly increased relative to that observed in the HR group, with concomitant increases in GPX4 protein levels, enhanced cell viability, a reduction in malondialdehyde content, decreased Fe²⁺ level, and the restoration of normal mitochondrial membrane potential. Transmission electron microscopy showed a reduced or absent mitochondrial crest and a damaged mitochondrial outer membrane. Targeting of HMOX1 by miR-3587 was confirmed by luciferase reporter gene assay. In conclusion, these preliminary results indicate that inhibition of miR-3587 promotes HO-1 upregulation, thereby protecting renal tissues from IR-induced ferroptosis.

The Antioxidant Transcription Factor Nrf2 in Cardiac Ischemia-Reperfusion Injury

Nuclear factor erythroid-2 related factor 2 (Nrf2) is a transcription factor that controls cellular defense responses against toxic and oxidative stress by modulating the expression of genes involved in antioxidant response and drug detoxification. In addition to maintaining redox homeostasis, Nrf2 is also involved in various cellular processes including metabolism and inflammation. Nrf2 activity is tightly regulated at the transcriptional, post-transcriptional and post-translational levels, which allows cells to quickly respond to pathological stress. In the present review, we describe the molecular mechanisms underlying the transcriptional regulation of Nrf2. We also focus on the impact of Nrf2 in cardiac ischemia-reperfusion injury, a condition that stimulates the overproduction of reactive oxygen species. Finally, we analyze the protective effect of several natural and synthetic compounds that induce Nrf2 activation and protect against ischemia-reperfusion injury in the heart and other organs, and their potential clinical application.

Heme Oxgenase-1, a Cardinal Modulator of Regulated Cell Death and Inflammation

Heme oxygenase catalyzes the rate-limiting step in heme degradation in order to generate biliverdin, carbon monoxide (CO), and iron. The inducible form of the enzyme, heme oxygenase-1 (HO-1), exerts a central role in cellular protection. The substrate, heme, is a potent pro-oxidant that can accelerate inflammatory injury and promote cell death. HO-1 has been implicated as a key mediator of inflammatory cell and tissue injury, as validated in preclinical models of acute lung injury and sepsis. A large body of work has also implicated HO-1 as a cytoprotective molecule against various forms of cell death, including necrosis, apoptosis and newly recognized regulated cell death (RCD) programs such as necroptosis, pyroptosis, and ferroptosis. While the antiapoptotic potential of HO-1 and its reaction product CO in apoptosis regulation has been extensively characterized, relatively fewer studies have explored the regulatory role of HO-1 in other forms of necrotic and inflammatory RCD (i.e., pyroptosis, necroptosis and ferroptosis). HO-1 may provide anti-inflammatory protection in necroptosis or pyroptosis. In contrast, in ferroptosis, HO-1 may play a pro-death role via enhancing iron release. HO-1 has also been implicated in co-regulation of autophagy, a cellular homeostatic program for catabolic recycling of proteins and organelles. While autophagy is primarily associated with cell survival, its occurrence can coincide with RCD programs. This review will summarize the roles of HO-1 and its reaction products in co-regulating RCD and autophagy programs, with its implication for both protective and detrimental tissue responses, with emphasis on how these impact HO-1 as a candidate therapeutic target in disease.

MicroRNA mediated regulation of the major redox homeostasis switch, Nrf2, and its impact on oxidative stress-induced ischemic/reperfusion injury

Ischemia/reperfusion injury (IRI) initiates from oxidative stress caused by lack of blood supply and subsequent reperfusion. It is often associated with sterile inflammation, cell death and microvascular dysfunction, which ultimately results in myocardial, cerebral and hepatic IRIs. Reportedly, deregulation of Nrf2 pathway plays a significant role in the oxidative stress-induced IRIs. Further, microRNAs (miRNAs/miRs) are proved to regulate the expression and activation of Nrf2 by targeting either the 3'-UTR or the upstream regulators of Nrf2. Additionally, compounds (crocin, ZnSO4 and ginsenoside Rg1) that modulate the levels of the Nrf2-regulating miRNAs were found to exhibit a protective effect against IRIs of different organs. Therefore, the current review briefs the impact of ischemia reperfusion (I/R) pathogenesis in various organs, role of miRNAs in the regulation of Nrf2 and the I/R protective effect of compounds that alter their expression.

The Effects of Hypoxia-Reoxygenation in Mouse Digital Flexor Tendon-Derived Cells

Objective

Ischemia-reperfusion injury refers to the exacerbated and irreversible tissue damage caused by blood flow restoration after a period of ischemia. The hypoxia-reoxygenation (H/R) model in vitro is ideal for studying ischemia-reperfusion injury at the cellular level. We employed this model and investigated the effects of cobalt chloride- (CoCl₂-) induced H/R in cells derived from mouse digital flexor tendons.

Materials and Methods

Various H/R conditions were simulated via treatment of tendon-derived cells with different concentrations of CoCl₂ for 24 h, followed by removal of CoCl₂ to restore a normal oxygen state for up to 96 h. Cell viability was measured using the Cell Counting Kit-8 (CCK-8) assay. Cell growth was determined via observation of cell morphology and proliferation. Oxidative stress markers and mitochondrial activity were detected. The expression levels of hypoxia-inducible factor- (HIF-) 1α, vascular endothelial growth factor-A (VEGF-A), collagen I, and collagen III were determined using Western blot (WB), real-time PCR, and immunofluorescence staining. Cellular apoptosis was analyzed via flow cytometry, and the expression of apoptosis-related proteins Bax and bcl-2 was examined using WB.

Results

The cells treated with low concentrations of CoCl₂ showed significantly increased cell viability after reoxygenation. The increase in cell viability was even more pronounced in cells that had been treated with high concentrations of CoCl₂. Under H/R conditions, cell morphology and growth were unchanged, while oxidative stress reaction was induced and mitochondrial activity was increased. H/R exerted opposite effects on the expression of HIF-1α mRNA and protein. Meanwhile, the expression of VEGF-A was upregulated, whereas collagen type I and type III were significantly downregulated. The level of cellular apoptosis did not show significant changes during H/R, despite the significantly increased Bax protein and reduced bcl-2 protein levels that led to an increase in the Bax/bcl-2 ratio during reoxygenation.

Conclusions

Tendon-derived cells were highly tolerant to the hypoxic environments induced by CoCl₂. Reoxygenation after hypoxia preconditioning promoted cell viability, especially in cells treated with high concentrations of CoCl₂. H/R conditions caused oxidative stress responses but did not affect cell growth. The H/R process had a notable impact on collagen production and expression of apoptosis-related proteins by tendon-derived cells, while the level of cellular apoptosis remained unchanged.

Blocking exosomal miRNA-153-3p derived from bone marrow mesenchymal stem cells ameliorates hypoxia-induced myocardial and microvascular damage by targeting the ANGPT1-mediated VEGF/PI3k/Akt/eNOS pathway

It has been widely reported that exosomes derived from mesenchymal stem cells (MSCs) have a protective effect on myocardial infarction (MI). However, the specific molecules which play a damaging role in MSCs shuttled miRNAs are much less explored. MiRNA-153-3p (miR-153-3p) is a vital miRNA which has been proved to modulate cell proliferation, apoptosis, angiogenesis, peritoneal fibrosis and aortic calcification. Here, we aim to study the effect and mechanism of miR-153-3p in MSC-derived exosomes on hypoxia-induced myocardial and microvascular damage. The exosomes of MSCs were isolated and identified, and the MSCs-exosomes with low expression of miR-153-3p (exo-miR-153-3p^-) were constructed to interfere with the endothelial cells and cardiomyocytes in the oxygen-glucose deprivation (OGD) model. The viability, apoptosis, angiogenesis of endothelial cells and cardiomyocytes were determined. Additionally, ANGPT1/VEGF/VEGFR2/PI3K/Akt/eNOS pathway was detected by ELISA and/or western blot. The results illustrated that exo-miR-153-3p^- significantly reduced the apoptosis of endothelial cells and cardiomyocytes and promoted their viability. Meanwhile, exo-miR-153-3p^- can promote the angiogenesis of endothelial cells. Mechanistically, miR-153-3p regulates the VEGF/VEGFR2/PI3K/Akt/eNOS pathways by targeting ANGPT1. Intervention with VEGFR2 inhibitor (SU1498, 1 μM) remarkably reversed the protective effect of exo-miR-153-3p^- in vascular endothelial cells and cardiomyocytes treated by OGD. Collectively, MSCs-derived exosomes with low-expressed miR-153-3p notably promotes the activation of ANGPT1 and the VEGF/VEGFR2 /PI3K/Akt/eNOS pathways, thereby preventing the damages endothelial cells and cardiomyocytes against hypoxia.

Role of Nrf2 and Its Activators in Cardiocerebral Vascular Disease

Cardiocerebral vascular disease (CCVD) is a common disease with high morbidity, disability, and mortality. Oxidative stress (OS) is closely related to the progression of CCVD. Abnormal redox regulation leads to OS and overproduction of reactive oxygen species (ROS), which can cause biomolecular and cellular damage. The Nrf2/antioxidant response element (ARE) signaling pathway is one of the most important defense systems against exogenous and endogenous OS injury, and Nrf2 is regarded as a vital pharmacological target. The complexity of the CCVD pathological process and the current difficulties in conducting clinical trials have hindered the development of therapeutic drugs. Furthermore, little is known about the role of the Nrf2/ARE signaling pathway in CCVD. Clarifying the role of the Nrf2/ARE signaling pathway in CCVD can provide new ideas for drug design. This review details the recent advancements in the regulation of the Nrf2/ARE system and its role and activators in common CCVD development.

Correction to: Inhibition of miR‑153 ameliorates ischemia/reperfusion‑induced cardiomyocytes apoptosis by regulating Nrf2/HO‑1 signaling in rats

An amendment to this paper has been published and can be accessed via the original article.