PICOT alleviates myocardial ischemia-reperfusion injury by reducing intracellular levels of reactive oxygen species

Adenosine triphosphate-induced cell death in heart failure: Is there a link?

Heart failure (HF) has emerged as one of the foremost global health threats due to its intricate pathophysiological mechanisms and multifactorial etiology. Adenosine triphosphate (ATP)-induced cell death represents a novel form of regulated cell deaths, marked by cellular energy depletion and metabolic dysregulation stemming from excessive ATP accumulation, identifying its uniqueness compared to other cell death processes modalities such as programmed cell death and necrosis. Growing evidence suggests that ATP-induced cell death (AICD) is predominantly governed by various biological pathways, including energy metabolism, redox homeostasis and intracellular calcium equilibrium. Recent research has shown that AICD is crucial in HF induced by pathological conditions like myocardial infarction, ischemia-reperfusion injury, and chemotherapy. Thus, it is essential to investigate the function of AICD in the pathogenesis of HF, as this may provide a foundation for the development of targeted therapies and novel treatment strategies. This review synthesizes current advancements in understanding the link between AICD and HF, while further elucidating its involvement in cardiac remodeling and HF progression.

Disulfide stress and its role in cardiovascular diseases

Cardiovascular disease (CVD) is one of the leading causes of mortality in humans, and oxidative stress plays a pivotal role in disease progression. This phenomenon typically arises from weakening of the cellular antioxidant system or excessive accumulation of peroxides. This review focuses on a specialized form of oxidative stress-disulfide stress-which is triggered by an imbalance in the glutaredoxin and thioredoxin antioxidant systems within the cell, leading to the accumulation of disulfide bonds. The genesis of disulfide stress is usually induced by extrinsic pathological factors that disrupt the thiol-dependent antioxidant system, manifesting as sustained glutathionylation of proteins, formation of abnormal intermolecular disulfide bonds between cysteine-rich proteins, or irreversible oxidation of thiol groups to sulfenic and sulfonic acids. Disulfide stress not only precipitates the collapse of the antioxidant system and the accumulation of reactive oxygen species, exacerbating oxidative stress, but may also initiate cellular inflammation, autophagy, and apoptosis through a cascade of signaling pathways. Furthermore, this review explores the detrimental effects of disulfide stress on the progression of various CVDs including atherosclerosis, hypertension, myocardial ischemia-reperfusion injury, diabetic cardiomyopathy, cardiac hypertrophy, and heart failure. This review also proposes several potential therapeutic avenues to improve the future treatment of CVDs.

Effects of Long Noncoding RNA HOTAIR Targeting miR-138 on Inflammatory Response and Oxidative Stress in Rat Cardiomyocytes Induced by Hypoxia and Reoxygenation

Objective

To investigate the effects of HOX transcript antisense RNA (HOTAIR) and miR-138 on inflammatory response and oxidative stress (OS) induced by IRI in rat cardiomyocytes.

Methods

H9C2 cells were divided into the control group, H/R group, H/R+siRNA NC group, H/R+si-HOTAIR group, and H/R+si-HOTAIR+inhibitor group. Expression levels of HOTAIR, miR-138, and inflammatory factors were detected by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The double luciferase reporter gene assay was used to detect the targeting relationship between HOTAIR and miR-138.

Results

Compared with the control group, the level of miR-138 and SOD in the H/R group was obviously reduced, while the expression levels of the HOTAIR, MDA, and NF-κB pathway were obviously increased. Compared with the H/R group, the level of miR-138 and SOD in the H/R+si-HOTAIR group was obviously increased, and the expression levels of the HOTAIR, MDA, and NF-κB pathway were obviously decreased. Compared with the H/R+si-HOTAIR group, the level of SOD in the H/R+si-HOTAIR+inhibitor group decreased; MDA content and the NF-κB pathway expression level increased. In the double luciferase reporter gene assay, compared with the HOTAIR wt+NC group, the luciferase activity of the HOTAIR wt+miR-138 mimic group was obviously decreased.

Conclusions

Silent HOTAIR can promote the expression of miR-138 and inhibit H/R-induced inflammatory response and OS by regulating the NF-κB pathway, thus protecting cardiomyocytes.

The protective effect of allicin on myocardial ischemia-reperfusion by inhibition of Ca2+ overload-induced cardiomyocyte apoptosis via the PI3K/GRK2/PLC-γ/IP3R signaling pathway

Purpose: To investigate the protective effect and mechanism of allicin on myocardial ischemia-reperfusion (MI/R) injury.

Methods: We investigated the mechanisms by which allicin attenuated the MI/R injury by focusing on phosphoinositide 3-kinase, G protein coupled receptor kinases 2, phospholipase Cγ and cardiomyocyte apoptosis. Sixty male mice were randomly assigned into three groups: repeated MI/R (model), sham-operated (control), and MI/R+ allicin group (allicin). Ultrasound examination was used to examine the cardiac function. Masson staining was used to evaluate the myocardial infarct area. TUNEL assay was performed to examine the anti-apoptotic effect of allicin. Differentially expressed genes (DEGs) and pathways were analyzed by mRNA microarray analysis. Immunofluorescence staining and western blot were carried out to detect the effect of allicin on the PI3K. A pan-PLC activator, m-3M3FBS, was applied to investigate whether allicin induced cardiomyocyte apoptosis was via the GRK2/PLC/IP3R signaling pathway.

Results: Masson staining and the TUNEL assay revealed that allicin reduced infarct size and played an anti-apoptotic role in M/IR. Ultrasound examination revealed that allicin improved cardiac function after M/IR injury. Gene ontology analysis indicated that the calcium signaling pathway and PI3KCA(PI3K) were selected. Immunofluorescence staining and western blot exposed that PI3K was activated by allicin during MI/R injury. Fura-2AM staining revealed that the PI3K -mediated GRK2/PLC-γ/IP3R pathway may be involved in the protective effect of allicin on MI/R injury.

Conclusions: Allicin has a protective effect on MI/R injury. This effect might be associated with the inhibition of Ca²⁺ overload-induced apoptosis and the inhibition of the PI3K -mediated GRK2/PLC-γ/IP3R signaling pathway.

Thiol-based redox-active proteins as cardioprotective therapeutic agents in cardiovascular diseases

Thiol-based redox compounds, namely thioredoxins (Trxs), glutaredoxins (Grxs) and peroxiredoxins (Prxs), stand as a pivotal group of proteins involved in antioxidant processes and redox signaling. Glutaredoxins (Grxs) are considered as one of the major families of proteins involved in redox regulation by removal of S-glutathionylation and thereby reactivation of other enzymes with thiol-dependent activity. Grxs are also coupled to Trxs and Prxs recycling and thereby indirectly contribute to reactive oxygen species (ROS) detoxification. Peroxiredoxins (Prxs) are a ubiquitous family of peroxidases, which play an essential role in the detoxification of hydrogen peroxide, aliphatic and aromatic hydroperoxides, and peroxynitrite. The Trxs, Grxs and Prxs systems, which reversibly induce thiol modifications, regulate redox signaling involved in various biological events in the cardiovascular system. This review focuses on the current knowledge of the role of Trxs, Grxs and Prxs on cardiovascular pathologies and especially in cardiac hypertrophy, ischemia/reperfusion (I/R) injury and heart failure as well as in the presence of cardiovascular risk factors, such as hypertension, hyperlipidemia, hyperglycemia and metabolic syndrome. Further studies on the roles of thiol-dependent redox systems in the cardiovascular system will support the development of novel protective and therapeutic strategies against cardiovascular diseases.

Effect of Auricularia auricula fermentation broth on the liver and stomach of mice with acute alcoholism

In this paper, the protective effect of Auricularia auricula (A. auricula) fermentation broth on the liver and stomach of mice with acute alcoholism was studied. The A. auricula fermentation broth was prepared by adding Bacillus subtilis, lactic acid bacteria, and Saccharomyces cerevisiae to A. auricula solution. The changes of physical and chemical indexes during the fermentation of A. auricula were monitored, and the results showed the content of polysaccharides and protein in the two kinds of fermentation broth after the fermentation was completed. Furthermore, the characteristic structures of active substances such as proteins, polysaccharides and phenolics were found in the A. auricula fermentation by structural analysis. Antioxidant activity test results showed that the A. auricula fermentation broth had a strong ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals. Cell experiments showed that the fermentation broth of A. auricula could significantly enhance the activity of NRK cells and protect NRK cells from H₂O₂ damage. Animal experiments showed that the A. auricula fermentation broth had protective effects on the liver and stomach of mice with acute alcoholism, and significantly reduced the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total cholesterol (TC) and triglycerides (TG) in serum. These results indicated that the A. auricula fermentation broth had protective effects on the liver and stomach of mice with acute alcoholism, and could be used as a potential functional food to prevent liver and stomach damage caused by acute alcoholism.

TRIM16 protects human periodontal ligament stem cells from oxidative stress-induced damage via activation of PICOT

Periodontitis is a chronic inflammatory disease that result in severe loss of supporting structures and substantial tooth loss. Oxidative stress is tightly involved in the progression of periodontitis. Tripartite Motif 16 (TRIM16) has been identified as a novel regulatory protein in response to oxidative and proteotoxic stresses. The present study aimed to investigate the role of TRIM16 in human periodontal ligament stem cells (hPDLSCs) under oxidative stress. First, we found that the expression of TRIM16 decreased after exposure to H₂O₂. Then TRIM16 overexpression alleviated H₂O₂-induced oxidative stress by enhancing antioxidant capacity and reducing the amount of intracellular reactive oxygen species (ROS) and reactive nitrogen species (RNS). TRIM16 increased cell viability, inhibited cell apoptosis and the depolarization of the mitochondrial membrane potential in hPDLSCs. Furthermore, TRIM16 attenuated H₂O₂-induced suppression of osteogenic differentiation. Mechanistically, TRIM16 promoted the activation of protein kinase C (PKC)-interacting cousin of thioredoxin (PICOT), p-Akt and Nrf2, while knockdown of PICOT reversed TRIM16-mediated ROS resistance and decreased the expression of p-Akt and Nrf2. In conclusion, TRIM16 alleviated oxidative damage in hPDLSCs via the activation of PICOT/Akt/Nrf2 pathway, suggesting that TRIM16 could be a promising target to develop effective therapies for periodontitis.

Glutaredoxins with iron-sulphur clusters in eukaryotes - Structure, function and impact on disease

Among the thioredoxin superfamily of proteins, the observation that numerous glutaredoxins bind iron-sulphur (Fe/S) clusters is one of the more recent and major developments concerning their functional properties. Glutaredoxins are present in most organisms. All members of the class II subfamily (including most monothiol glutaredoxins), but also some members of the class I (mostly dithiol glutaredoxins) and class III (land plant-specific monothiol or dithiol glutaredoxins) are Fe/S proteins. In glutaredoxins characterised so far, the [2Fe2S] cluster is coordinated by two active-site cysteine residues and two molecules of non-covalently bound glutathione in homo-dimeric complexes bridged by the cluster. In contrast to dithiol glutaredoxins, monothiol glutaredoxins possess no or very little oxidoreductase activity, but have emerged as important players in cellular iron metabolism. In this review we summarise the recent developments of the most prominent Fe/S glutaredoxins in eukaryotes, the mitochondrial single domain monothiol glutaredoxin 5, the chloroplastic single domain monothiol glutaredoxin S14 and S16, the nuclear/cytosolic multi-domain monothiol glutaredoxin 3, and the mitochondrial/cytosolic dithiol glutaredoxin 2.

PICOT promotes T lymphocyte proliferation by down-regulating cyclin D2 expression

The mammalian protein kinase C-interacting cousin of thioredoxin (PICOT; also termed glutaredoxin 3) is a multi-domain monothiol glutaredoxin that is involved in a wide variety of signaling pathways and biological processes. PICOT is required for normal and transformed cell growth and is critical for embryonic development. Recent studies in T lymphocytes demonstrated that PICOT can translocate to the nucleus and interact with embryonic ectoderm development, a polycomb group protein and a core component of the polycomb repressive complex 2, which contributes to the maintenance of transcriptional repression and chromatin remodeling. Furthermore, PICOT was found to interact with chromatin-bound embryonic ectoderm development and alter the extent of histone 3 lysine 27 trimethylation at the promoter region of selected polycomb repressive complex 2 target genes. PICOT knockdown in Jurkat T cells led to increased histone 3 lysine 27 trimethylation at the promoter region of CCND2, a cell cycle-regulating gene which encodes the cyclin D2 protein. As a result, the expression levels of CCND2 mRNA and protein levels were reduced, concomitantly with inhibition of the cell growth rate. Analysis of multiple data sets from the Cancer Genome Atlas revealed that a high expression of PICOT correlated with a low expression of CCND2 in a large number of human cancers. In addition, this parameter correlated with poor patient survival, suggesting that the ratio between PICOT/CCND2 mRNA levels might serve as a predictor of patient survival in selected types of human cancer.

Design and synthesis of novel SCM-198 analogs as cardioprotective agents: Structure-activity relationship studies and biological evaluations

SCM-198 (Leonurine) has attracted great attention due to its cardioprotective effects in myocardial infarction (MI). However, no systematic modifications and structure-activity relationship (SAR) studies could be traced so far. In this study, 35 analogs of SCM-198 were designed, synthesized and their cardioprotective effects were evaluated. The cell viability assay on cardiomyocyte cell line H9c2 challenged with H₂O₂ showed that several analogs exhibited more potent cytoprotective effects than SCM-198 at 1 μM and 10 μM concentrations. LDH release level in cells treated with 1 μM 14o was comparable with cells treated with 10 μM SCM-198. Results of Bcl-2 expression and caspase-3 activation accordingly indicated higher protective activity of 14o than SCM-198. Moreover, in a mouse model of MI, the mice pretreated with 14o had much lower infarct size compared with that of SCM-198. The mechanism study suggested that 14o improved cardiac morphology and reduced apoptosis of cardiomyocytes in the border zone of infarction, as proved by H&E and TUNEL staining.

Redox Regulation via Glutaredoxin-1 and Protein S-Glutathionylation

Significance: Over the past several years, oxidative post-translational modifications of protein cysteines have been recognized for their critical roles in physiology and pathophysiology. Cells have harnessed thiol modifications involving both oxidative and reductive steps for signaling and protein processing. One of these stages requires oxidation of cysteine to sulfenic acid, followed by two reduction reactions. First, glutathione (reduced glutathione [GSH]) forms a S-glutathionylated protein, and second, enzymatic or chemical reduction removes the modification. Under physiological conditions, these steps confer redox signaling and protect cysteines from irreversible oxidation. However, oxidative stress can overwhelm protein S-glutathionylation and irreversibly modify cysteine residues, disrupting redox signaling. Critical Issues: Glutaredoxins mainly catalyze the removal of protein-bound GSH and help maintain protein thiols in a highly reduced state without exerting direct antioxidant properties. Conversely, glutathione S-transferase (GST), peroxiredoxins, and occasionally glutaredoxins can also catalyze protein S-glutathionylation, thus promoting a dynamic redox environment. Recent Advances: The latest studies of glutaredoxin-1 (Glrx) transgenic or knockout mice demonstrate important distinct roles of Glrx in a variety of pathologies. Endogenous Glrx is essential to maintain normal hepatic lipid homeostasis and prevent fatty liver disease. Further, in vivo deletion of Glrx protects lungs from inflammation and bacterial pneumonia-induced damage, attenuates angiotensin II-induced cardiovascular hypertrophy, and improves ischemic limb vascularization. Meanwhile, exogenous Glrx administration can reverse pathological lung fibrosis. Future Directions: Although S-glutathionylation modifies many proteins, these studies suggest that S-glutathionylation and Glrx regulate specific pathways in vivo, and they implicate Glrx as a potential novel therapeutic target to treat diverse disease conditions. Antioxid. Redox Signal. 32, 677-700.

Astaxanthin Complexes to Attenuate Muscle Damage after In Vivo Femoral Ischemia-Reperfusion

(1) Background: Reperfusion injury refers to the cell and tissue damage induced, when blood flow is restored after an ischemic period. While reperfusion reestablishes oxygen supply, it generates a high concentration of radicals, resulting in tissue dysfunction and damage. Here, we aimed to challenge and achieve the potential of a delivery system based on astaxanthin, a natural antioxidant, in attenuating the muscle damage in an animal model of femoral hind-limb ischemia and reperfusion. (2) Methods: The antioxidant capacity and non-toxicity of astaxanthin was validated before and after loading into a polysaccharide scaffold. The capacity of astaxanthin to compensate stress damages was also studied after ischemia induced by femoral artery clamping and followed by varied periods of reperfusion. (3) Results: Histological evaluation showed a positive labeling for CD68 and CD163 macrophage markers, indicating a remodeling process. In addition, higher levels of Nrf2 and NQO1 expression in the sham group compared to the antioxidant group could reflect a reduction of the oxidative damage after 15 days of reperfusion. Furthermore, non-significant differences were observed in non-heme iron deposition in both groups, reflecting a cell population susceptible to free radical damage. (4) Conclusions: Our results suggest that the in situ release of an antioxidant molecule could be effective in improving the antioxidant defenses of ischemia/reperfusion (I/R)-damaged muscles.

PICOT (GLRX3) is a positive regulator of stress-induced DNA-damage response

Protein kinase C (PKC)-interacting cousin of thioredoxin (PICOT; also termed glutaredoxin 3 (Glrx3)) is a ubiquitously expressed protein that possesses an N-terminal monothiol thioredoxin (Trx) domain and two C-terminal tandem copies of a monothiol Glrx domain. It has an overall highly conserved amino acid sequence and is encoded by a unique gene, both in humans and mice, without having other functional gene homologs in the entire genome. Despite being discovered almost two decades ago, the biological function of PICOT remains largely ill-defined and its ramifications are underestimated considering the fact that PICOT-deficiency in mice results in embryonic lethality. Since classical Glrxs are important regulators of the cellular redox homeostasis, we tested whether PICOT participate in the stress-induced DNA-damage response, focusing on nuclear proteins that function as integral components of the DNA repair machinery. Using wild type versus PICOT-deficient (PICOT-KD) Jurkat T cells we found that the anti-oxidant mechanism in PICOT-deficient cells is impaired, and that these cells respond to genotoxic drugs, such as etoposide and camptothecin, by increased caspase-3 activity, a reduced survival and a slower and diminished phosphorylation of the histone protein, H2AX. Nevertheless, the effect of PICOT on the drug-induced phosphorylation of H2AX was independent of the cellular levels of reactive oxygen species. PICOT-deficient cells also demonstrated reduced and slower γH2AX foci formation in response to radiation. Furthermore, immunofluorescence staining using PICOT- and γH2AX-specific Abs followed by confocal microscopy demonstrated partial localization of PICOT at the γH2AX-containing foci at the site of the DNA double strand breaks. In addition, PICOT knockdown resulted in inhibition of phosphorylation of ATR, Chk1 and Chk2 kinases, which play an essential role in the DNA-damage response and serve as upstream regulators of γH2AX. The present data suggest that PICOT protects cells from DNA damage-inducing agents by operating as an upstream positive regulator of ATR-dependent signaling pathways. By promoting the activity of ATR, PICOT indirectly regulates the phosphorylation and activation of Chk1, Chk2, and γH2AX, which are critical components of the DNA damage repair mechanism and thereby attenuate the stress- and replication-induced genome instability.

Up-regulation of ANXA1 suppresses polymorphonuclear neutrophil infiltration and myeloperoxidase activity by activating STAT3 signaling pathway in rat models of myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) is recognized as a major cause of morbidity and mortality which is commonly associated with coronary artery disease. In recent studies, annexin A1 gene (ANXA1) has been discovered to be involved in the treatment for MIRI. In this study, the primary focus was on the molecular mechanism of ANXA1 in polymorphonuclear neutrophil (PMN) infiltration and myeloperoxidase (MPO) activity in rats with MIRI. Initially, microarray analysis was carried out in order to identify differentially expressed genes. Moreover, a rat model of MIRI was established for evaluating the expression of ANXA1, signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor (VEGF) in myocardial tissues. Following this, the ANXA1 vector, siRNA-ANXA1, and Stattic (inhibitor of STAT3 signaling pathway) were utilized for analyzing the regulatory role of ANXA1 in physiological indexes, hemodynamic parameters, inflammatory factors, myocardial infarct size, MPO activity, PMN infiltration, and apoptosis of PMNs. Furthermore, the relationship between ANXA1 and STAT3 signaling pathway was analyzed. Initially, a reduction in the expression of ANXA1, STAT3 and VEGF in myocardial tissues of MIRI rats was found. To elaborate, overexpressed ANXA1 inhibited levels of inflammatory factors, the activation of PMN infiltration, reduced the degree of PMN infiltration, and decreased the apoptosis of PMNs. More importantly, down-regulated ANXA1 inhibited the activation of STAT3 signaling pathway, which thereby suppressed VEGF expression. With this all taken into account, the present study presents that up-regulated ANXA1 inhibits PMN infiltration and MPO activity by activation of STAT3 signaling pathway in rats with MIRI.

PKC and PKN in heart disease

The protein kinase C (PKC) and closely related protein kinase N (PKN) families of serine/threonine protein kinases play crucial cellular roles. Both kinases belong to the AGC subfamily of protein kinases that also include the cAMP dependent protein kinase (PKA), protein kinase B (PKB/AKT), protein kinase G (PKG) and the ribosomal protein S6 kinase (S6K). Involvement of PKC family members in heart disease has been well documented over the years, as their activity and levels are mis-regulated in several pathological heart conditions, such as ischemia, diabetic cardiomyopathy, as well as hypertrophic or dilated cardiomyopathy. This review focuses on the regulation of PKCs and PKNs in different pathological heart conditions and on the influences that PKC/PKN activation has on several physiological processes. In addition, we discuss mechanisms by which PKCs and the closely related PKNs are activated and turned-off in hearts, how they regulate cardiac specific downstream targets and pathways, and how their inhibition by small molecules is explored as new therapeutic target to treat cardiomyopathies and heart failure.

microRNA-135a protects against myocardial ischemia-reperfusion injury in rats by targeting protein tyrosine phosphatase 1B

microRNAs are an emerging class of molecules that regulate pathogenesis of cardiovascular diseases. Here we aim to elucidate the effects and mechanism of miR-135a, a previously reported regulator of ischemia-reperfusion (I/R) injury, in myocardial I/R injury. Quantitative real-time polymerase chain reaction analysis revealed that the expression level of miR-135a was significantly decreased both in the rat I/R group and H9c2 cells subjected to hypoxia/reoxygenation. Overexpression of miR-135a in vivo markedly decreased the infarct size and inhibited the I/R-induced cardiomyocyte apoptosis. Overexpression of miR-135a in H9c2 also exerted antiapoptosis effects. Furthermore, bioinformatics analysis, luciferase activity, and the Western blot assay indicated that protein tyrosine phosphatase 1B (PTP1B) is a direct target of miR-135a. In addition, the expression of proapoptotic-related genes, such as p53, Bax, and cleaved caspase3, were decreased in association with the downregulation of PTP1B. In summary, this study demonstrates that miR-135a exerts protective effects against myocardial I/R injury by targeting PTP1B.

Mitochondria "THE" target of myocardial conditioning

Several interventions, such as ischemic preconditioning, remote pre/perconditioning, or postconditioning, are known to decrease lethal myocardial ischemia-reperfusion injury. While several signal transduction pathways become activated by such maneuvers, they all have a common end point, namely, the mitochondria. These organelles represent an essential target of the cardioprotective strategies, and the preservation of mitochondrial function is central for the reduction of ischemia-reperfusion injury. In the present review, we address the role of mitochondria in the different conditioning strategies; in particular, we focus on alterations of mitochondrial function in terms of energy production, formation of reactive oxygen species, opening of the mitochondrial permeability transition pore, and mitochondrial dynamics induced by ischemia-reperfusion.

Long non-coding RNA-ROR aggravates myocardial ischemia/reperfusion injury

Long non-coding RNAs (lncRNAs) play an important role in the pathogenesis of cardiovascular diseases, especially in myocardial infarction and ischemia/reperfusion (I/R). However, the underlying molecular mechanism remains unclear. In this study, we determined the role and the possible underlying molecular mechanism of lncRNA-ROR in myocardial I/R injury. H9c2 cells and human cardiomyocytes (HCM) were subjected to either hypoxia/reoxygenation (H/R), I/R or normal conditions (normoxia). The expression levels of lncRNA-ROR were detected in serum of myocardial I/R injury patients, H9c2 cells, and HCM by qRT-PCR. Then, levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) were measured by kits. Cell viability, apoptosis, apoptosis-associated factors, and p38/MAPK pathway were examined by MTT, flow cytometry, and western blot assays. Furthermore, reactive oxygen species (ROS) production was determined by H2DCF-DA and MitoSOX Red probes with flow cytometry. NADPH oxidase activity and NOX2 protein levels were measured by lucigenin chemiluminescence and western blot. Results showed that lncRNA-ROR expression was increased in I/R patients and in H/R treatment of H9c2 cells and HCM. Moreover, lncRNA-ROR significantly promoted H/R-induced myocardial injury via stimulating release of LDH, MDA, SOD, and GSH-PX. Furthermore, lncRNA-ROR decreased cell viability, increased apoptosis, and regulated expression of apoptosis-associated factors. Additionally, lncRNA-ROR increased phosphorylation of p38 and ERK1/2 expression and inhibition of p38/MAPK, and rescued lncRNA-ROR-induced cell injury in H9c2 cells and HCM. ROS production, NADPH oxidase activity, and NOX2 protein levels were promoted by lncRNA-ROR. These data suggested that lncRNA-ROR acted as a therapeutic agent for the treatment of myocardial I/R injury.