MiR-153 regulates cardiomyocyte apoptosis by targeting Nrf2/HO-1 signaling

MicroRNAs as Regulators of Radiation-Induced Oxidative Stress

microRNAs (miRNAs) represent small RNA molecules involved in the regulation of gene expression. They are implicated in the regulation of diverse cellular processes ranging from cellular homeostasis to stress responses. Unintended irradiation of the cells and tissues, e.g., during medical uses, induces various pathological conditions, including oxidative stress. miRNAs may regulate the expression of transcription factors (e.g., nuclear factor erythroid 2 related factor 2 (Nrf2), nuclear factor kappa B (NF-κB), tumor suppressor protein p53) and other redox-sensitive genes (e.g., mitogen-activated protein kinase (MAPKs), sirtuins (SIRTs)), which trigger and modulate cellular redox signaling. During irradiation, miRNAs mainly act with reactive oxygen species (ROS) to regulate the cell fate. Depending on the pathway involved and the extent of oxidative stress, this may lead to cell survival or cell death. In the context of radiation-induced oxidative stress, miRNA-21 and miRNA-34a are among the best-studied miRNAs. miRNA-21 has been shown to directly target superoxide dismutase (SOD), or NF-κB, whereas miRNA-34a is a direct regulator of NADPH oxidase (NOX), SIRT1, or p53. Understanding the mechanisms underlying radiation-induced injury including the involvement of redox-responsive miRNAs may help to develop novel approaches for modulating the cellular response to radiation exposure.

The Role of NRF2 in Trinucleotide Repeat Expansion Disorders

Trinucleotide repeat expansion disorders, a diverse group of neurodegenerative diseases, are caused by abnormal expansions within specific genes. These expansions trigger a cascade of cellular damage, including protein aggregation and abnormal RNA binding. A key contributor to this damage is oxidative stress, an imbalance of reactive oxygen species that harms cellular components. This review explores the interplay between oxidative stress and the NRF2 pathway in these disorders. NRF2 acts as the master regulator of the cellular antioxidant response, orchestrating the expression of enzymes that combat oxidative stress. Trinucleotide repeat expansion disorders often exhibit impaired NRF2 signaling, resulting in inadequate responses to excessive ROS production. NRF2 activation has been shown to upregulate antioxidative gene expression, effectively alleviating oxidative stress damage. NRF2 activators, such as omaveloxolone, vatiquinone, curcumin, sulforaphane, dimethyl fumarate, and resveratrol, demonstrate neuroprotective effects by reducing oxidative stress in experimental cell and animal models of these diseases. However, translating these findings into successful clinical applications requires further research. In this article, we review the literature supporting the role of NRF2 in the pathogenesis of these diseases and the potential therapeutics of NRF2 activators.

The study of HMOX1 DNA methylation and gene expression and the diagnostic potential of miR-153-3p in preeclampsia

Background: The objective was to elucidate the potential epigenetic regulatory mechanism in HMOX1 expression in preeclampsia. Materials & methods: HMOX1 promoter DNA methylation was evaluated in the placental tissue and blood of preeclamptic and normotensive pregnant women. HMOX1 and miR-153-3p gene expression were assessed in placental tissue and peripheral blood mononuclear cells (PBMCs). Related microarray datasets in the Gene Expression Omnibus database were also analyzed. Results: In placental tissue, despite HMOX1 expression downregulation, there was no significant change in HMOX1 methylation. In PBMCs, there was no significant alteration in HMOX1 expression, while hypomethylation was observed in blood. The miR-153-3p expression increased in the placental tissue and in the PBMCs of preeclampsia. Conclusion: DNA methylation does not affect HMOX1 expression, while miR-153-3p might be a biomarker for preeclampsia.

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.

RNA sequencing-based identification of the regulatory mechanism of microRNAs, transcription factors, and corresponding target genes involved in vascular dementia

Vascular dementia (VaD) is the second most common form of dementia with uncertain mechanisms and no effective treatments. microRNAs (miRNAs) and transcription factors (TFs) are considered regulatory factors of genes involved in many diseases. Therefore, this work investigated the aberrantly expressed miRNAs, TFs, corresponding target genes, and their co-regulatory networks in the cortex of rats with bilateral common carotid artery occlusion (2VO) to uncover the potential mechanism and biomarkers of VaD. Differentially expressed genes (DEGs), miRNAs (DEMs), and TFs (DETFs) were identified using RNA sequencing, and their interaction networks were constructed using Cytoscape. The results showed that rats with 2VO had declined cognitive abilities and neuronal loss in the cortex than sham rats. DEGs, DEMs, and DETFs were discriminated between rats with 2VO and sham rats in the cortex, as shown by the 13 aberrantly expressed miRNAs, 805 mRNAs, and 63 TFs. The miRNA-TF-target gene network was constructed, showing 523 nodes and 7237 edges. Five miRNAs (miR-5132-5p, miR-764-3p, miR-223-3p, miR-145-5p, and miR-122-5p), ten TFs (Mxi1, Nfatc4, Rxrg, Zfp523, Foxj2, Nkx6-1, Klf4, Klf5, Csrnp1, and Prdm6), and seven target genes (Serpine1, Nedd4l, Pxn, Col1a1, Plec, Trip12, and Tpm1) were chosen as the significant nodes to construct feed-forward loops (FFLs). Gene Ontology and pathway enrichment analysis revealed that these miRNA and TF-associated genes are mostly involved in the PI3K/Akt, neuroactive ligand–receptor interaction, calcium signaling, and Wnt signaling pathways, along with central locations around the cell membrane. They exert functions such as growth factor binding, integrin binding, and extracellular matrix structural constituent, with representative biological processes like vasculature development, cell–substrate adhesion, cellular response to growth factor stimulus, and synaptic transmission. Furthermore, the expression of three miRNAs (miR-145-5p, miR-122-5p, and miR-5132-5p), six TFs (Csrnp1, Klf4, Nfatc4, Rxrg, Foxj2, and Klf5), and five mRNAs (Serpine1, Plec, Nedd4l, Trip12, and Tpm1) were significantly changed in rats with VaD, in line with the outcome of RNA sequencing. In the potential FFL, miR-145-5p directly bound Csrnp1 and decreased its mRNA expression. These results might help the understanding of the underlying regulatory mechanisms of miRNA-TF-genes, providing potential therapeutic targets in VaD.

Recent Advances in the Role of Nuclear Factor Erythroid-2-Related Factor 2 in Spinal Cord Injury: Regulatory Mechanisms and Therapeutic Options

Nuclear factor erythroid-2-related factor 2 (Nrf2) is a pleiotropic transcription factor, and it has been documented that it can induce defense mechanisms both oxidative stress and inflammatory injury. At present, more and more evidences show that the Nrf2 signaling pathway is a key pharmacological target for the treatment of spinal cord injury (SCI), and activating the Nrf2 signaling pathway can effectively treat the inflammatory injury and oxidative stress after SCI. This article firstly introduces the biological studies of the Nrf2 pathway. Meanwhile, it is more powerful to explain that activating the Nrf2 signaling pathway can effectively treat SCI by deeply exploring the relationship between Nrf2 and oxidative stress, inflammatory injury, and SCI. In addition, several potential drugs for the treatment of SCI by promoting Nrf2 activation and Nrf2-dependent gene expression are reviewed. And some other treatment strategies of SCI by modulating the Nrf2 pathway are also summarized. It will provide new ideas and directions for the treatment of SCI.

NRF2-suppressed vascular calcification by regulating the antioxidant pathway in chronic kidney disease

Vascular calcification (VC), in which vascular smooth muscle cells (VSMCs) undergo differentiation and osteogenic transition, is a common complication of chronic kidney disease (CKD). Recent findings show that nuclear factor-erythroid-2-related factor 2 (NRF2) is an evolutionarily conserved antioxidant and beneficial in preventing vascular senescence and calcification. The roles of NRF2 in the initiation and progression of VC in CKD still need further investigation. CKD-associated VC model rats exhibited significant upregulation of NRF2, NAD(P)H: quinone oxidoreductase-1 (NQO1), osteogenic markers such as alkaline phosphatase (ALP), runt-related transcription factor-2 (RUNX2) and osteopontin (OPN), and β-catenin compared to CKD rats. Immunohistochemistry further verified these results. In addition, rat aortic VSMCs were isolated and subjected to four treatments: normal control, phosphorus-induced (Pi), Pi + NRF2 activator DMF, and Pi + NRF2 inhibitor ML385. The reactive oxygen species (ROS) generation, malondialdehyde (MDA) content, and calcium deposition of the four treatments were determined. The mRNA and protein expression levels of NRF2, NQO1, and haem oxygenase 1 (HO1) and the osteogenic markers ALP, Runx1, OPN, bone morphogenetic protein 2 (BMP2), and β-catenin were quantified by RT-PCR and western blotting. VSMC apoptosis was calculated by flow cytometry. The in vitro results suggested that intracellular oxidative stress and calcification were closely associated with NRF2 activity and that the activation of NRF2 could significantly suppress osteogenic transition and apoptosis in VSMCs. Thus, this study indicated that the NRF2-related antioxidant pathway can positively respond to and protect against the initiation and progression of VC in CKD by reducing oxidative stress. This study may contribute insights facilitating the application of the NRF2 antioxidative system as a therapeutic treatment for vascular diseases such as CKD.

Gossypol Acetic Acid Attenuates Cardiac Ischemia/Reperfusion Injury in Rats via an Antiferroptotic Mechanism

Myocardial ischemia/reperfusion (I/R) injury has been associated with ferroptosis, which is characterized by an iron-dependent accumulation of lipid peroxide to lethal levels. Gossypol acetic acid (GAA), a natural product taken from the seeds of cotton plants, prevents oxidative stress. However, the effects of GAA on myocardial I/R-induced ferroptosis remain unclear. This study investigated the ability of GAA to attenuate I/R-induced ferroptosis in cardiomyocytes along with the underlying mechanisms in a well-established rat model of myocardial I/R and isolated neonatal rat cardiomyocytes. H9c2 cells and cardiomyocytes were treated with the ferroptosis inducers erastin, RSL3, and Fe-SP. GAA could protect H9c2 cells against ferroptotic cell death caused by these ferroptosis inducers by decreasing the production of malondialdehyde and reactive oxygen species, chelating iron content, and downregulating mRNA levels of Ptgs2. GAA could prevent oxygen-glucose deprivation/reperfusion-induced cell death and lipid peroxidation in the cardiomyocytes. Moreover, GAA significantly attenuated myocardial infarct size, reduced lipid peroxidation, decreased the mRNA levels of the ferroptosis markers Ptgs2 and Acsl4, decreased the protein levels of ACSL4 and NRF2, and increased the protein levels of GPX4 in I/R-induced ex vivo rat hearts. Thus, GAA may play a cytoprotectant role in ferroptosis-induced cardiomyocyte death and myocardial I/R-induced ferroptotic cell death.

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.

Identification and Characterization of Novel circRNAs Involved in Muscle Growth of Blunt Snout Bream (Megalobrama amblycephala)

Circular RNAs (circRNAs), a novel class of endogenous RNAs, have been recognized to play important roles in the growth of animals. However, the regulatory mechanism of circRNAs on fish muscle growth is still unclear. In this study, we performed whole transcriptome analysis of skeletal muscles from two populations with different growth rates (fast-growing and slow-growing) of blunt snout bream (Megalobrama amblycephala), an important fish species for aquaculture. The selected circRNAs were validated by qPCR and Sanger sequencing. Pairs of circRNA–miRNA–mRNA networks were constructed with the predicted differentially expressed (DE) pairs, which revealed regulatory roles in muscle myogenesis and hypertrophy. As a result, a total of 445 circRNAs were identified, including 42 DE circRNAs between fast-growing (FG) and slow-growing (SG) groups. Many of these DE circRNAs were related with aminoglycan biosynthetic and metabolic processes, cytokinetic processes, and the adherens junction pathway. The functional prediction results showed that novel_circ_0001608 and novel_circ_0002886, competing to bind with dre-miR-153b-5p and dre-miR-124-6-5p, might act as competing endogenous RNAs (ceRNAs) to control MamblycephalaGene14755 (pik3r1) and MamblycephalaGene10444 (apip) level, respectively, thus playing an important regulatory role in muscle growth. Overall, these results will not only help us to further understand the novel RNA transcripts in M. amblycephala, but also provide new clues to investigate the potential mechanism of circRNAs regulating fish growth and muscle development.

An Overview of the Nrf2/ARE Pathway and Its Role in Neurodegenerative Diseases

Nrf2 is a basic region leucine-zipper transcription factor that plays a pivotal role in the coordinated gene expression of antioxidant and detoxifying enzymes, promoting cell survival in adverse environmental or defective metabolic conditions. After synthesis, Nrf2 is arrested in the cytoplasm by the Kelch-like ECH-associated protein 1 suppressor (Keap1) leading Nrf2 to ubiquitin-dependent degradation. One Nrf2 activation mechanism relies on disconnection from the Keap1 homodimer through the oxidation of cysteine at specific sites of Keap1. Free Nrf2 enters the nucleus, dimerizes with small musculoaponeurotic fibrosarcoma proteins (sMafs), and binds to the antioxidant response element (ARE) sequence of the target genes. Since oxidative stress, next to neuroinflammation and mitochondrial dysfunction, is one of the hallmarks of neurodegenerative pathologies, a molecular intervention into Nrf2/ARE signaling and the enhancement of the transcriptional activity of particular genes are targets for prevention or delaying the onset of age-related and inherited neurogenerative diseases. In this study, we review evidence for the Nrf2/ARE-driven pathway dysfunctions leading to various neurological pathologies, such as Alzheimer’s, Parkinson’s, and Huntington’s diseases, as well as amyotrophic lateral sclerosis, and the beneficial role of natural and synthetic molecules that are able to interact with Nrf2 to enhance its protective efficacy.

Biotherapeutic-loaded injectable hydrogels as a synergistic strategy to support myocardial repair after myocardial infarction

Myocardial infarction (MI) has been considered as the leading cause of cardiovascular-related deaths worldwide. Although traditional therapeutic agents including various bioactive species such as growth factors, stem cells, and nucleic acids have demonstrated somewhat usefulness for the restoration of cardiac functions, the therapeutic efficiency remains unsatisfactory most likely due to the off-target-associated side effects and low localized retention of the used therapeutic agents in the infarcted myocardium, which constitutes a substantial barrier for the effective treatment of MI. Injectable hydrogels are regarded as a minimally invasive technology that can overcome the clinical and surgical limitations of traditional stenting by a modulated sol-gel transition and localized transport of a variety of encapsulated cargoes, leading to enhanced therapeutic efficiency and improved patient comfort and compliance. However, the design of injectable hydrogels for myocardial repair and the mechanism of action of bioactive substance-loaded hydrogels for MI repair remain unclear. To elucidate these points, we summarized the recent progresses made on the use of injectable hydrogels for encapsulation of various therapeutic substances for MI treatment with an emphasis on the mechanism of action of hydrogel systems for myocardial repair. Specifically, the pathogenesis of MI and the rational design of injectable hydrogels for myocardial repair were presented. Next, the mechanisms of various biotherapeutic substance-loaded injectable hydrogels for myocardial repair was discussed. Finally, the potential challenges and future prospects for the use of injectable hydrogels for MI treatment were proposed for the purpose of drawing theoretical guidance on the development of novel therapeutic strategies for efficient treatment of MI.

Restored microRNA-326-5p Inhibits Neuronal Apoptosis and Attenuates Mitochondrial Damage via Suppressing STAT3 in Cerebral Ischemia/Reperfusion Injury

Studies have greatly explored the role of microRNAs (miRNAs) in cerebral ischemia/reperfusion injury (CI/RI). But the specific mechanism of miR-326-5p in CI/RI is still elusive. Hence, this study was to unmask the mechanism of miR-326-5p/signal transducer and activator of transcription-3 (STAT3) axis in CI/RI. Two models (oxygen and glucose deprivation [OGD] in primary rat cortical neurons and middle cerebral artery occlusion [MCAO] in Sprague-Dawley rats) were established to mimic CI/RI in vitro and in vivo, respectively. Loss- and gain-of function assays were performed with OGD-treated neurons and with MCAO rats. Afterward, viability, apoptosis, oxidative stress and mitochondrial membrane potential in OGD-treated neurons were tested, as well as pathological changes, apoptosis and mitochondrial membrane potential in brain tissues of MCAO rats. Mitofusin-2 (Mfn2), miR-326-5p and STAT3 expression in OGD-treated neurons and in brain tissues of MCAO rats were detected. Mfn2 and miR-326-5p were reduced, and STAT3 was elevated in OGD-treated neurons and brain tissues of MCAO rats. miR-326-5p targeted and negatively regulated STAT3 expression. Restoring miR-326-5p or reducing STAT3 reinforced viability, inhibited apoptosis and oxidative stress, increased mitochondrial membrane potential and increased Mfn2 expression in OGD-treated neurons. Up-regulating miR-326-5p or down-regulating STAT3 relieved pathological changes, inhibited apoptosis and elevated mitochondrial membrane potential and Mfn2 expression in brain tissues of rats with MCAO. This study elucidates that up-regulated miR-326-5p or down-regulated STAT3 protects against CI/RI by elevating Mfn2 expression.

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.

NRF2-Related Epigenetic Modifications in Cardiac and Vascular Complications of Diabetes Mellitus

Diabetes mellitus (DM) is a highly prevalent chronic disease that is accompanied with serious complications, especially cardiac and vascular complications. Thus, there is an urgent need to identify new strategies to treat diabetic cardiac and vascular complications. Nuclear factor erythroid 2-related factor 2 (NRF2) has been verified as a crucial target for the prevention and treatment of diabetic complications. The function of NRF2 in the treatment of diabetic complications has been widely reported, but the role of NRF2-related epigenetic modifications remains unclear. The purpose of this review is to summarize the recent advances in targeting NRF2-related epigenetic modifications in the treatment of cardiac and vascular complications associated with DM. We also discuss agonists that could potentially regulate NRF2-associated epigenetic mechanisms. This review provides a better understanding of strategies to target NRF2 to protect against DM-related cardiac and vascular complications.

Downregulation of RKIP promotes radioresistance of nasopharyngeal carcinoma by activating NRF2/NQO1 axis via downregulating miR-450b-5p

Dysregulation of RKIP and NRF2 has been widely involved in the therapy resistance of multiple malignances, however, their relation and the corresponding mechanisms, especially in radiation response, have not been elucidated. In this study, we revealed that RKIP could negatively regulate the expression of NRF2 in nasopharyngeal carcinoma (NPC) cells. Depletion or ectopic expression of NRF2 countered the pro- or anti- radioresistant effects of RKIP knockdown or overexpression on NPC cells, respectively, both in vitro and in vivo. Furthermore, our results indicated that NQO1 was positively regulated by NRF2 and served as the downstream effector of RKIP/NRF2 axis in regulation of NPC radioresistance. Mechanistically, miR-450b-5p, being positively regulated by RKIP in NPC cells, could sensitize NPC cells to irradiation by directly targeting and suppressing the level of NRF2. Besides, we analyzed the level of aforementioned molecules in NPC tissues. The results indicated that RKIP was significantly downregulated, NRF2 and NQO1 were notably upregulated in NPC tissues compared with in normal nasopharyngeal mucosa (NNM) tissues. Furthermore, RKIP and miR-450b-5p were remarkably lower, yet NRF2 and NQO1 were notably higher, in radioresistant NPC tissues relative to in radiosensitive NPC tissues. Consistent with the pattern in NPC cells, the RKIP/miR-450b-5p/NRF2/NQO1 axis was significantly correlated in NPC tissues. Downregulation of RKIP and miR-450b-5p, and upregulation of NRF2 and NQO1, positively correlated to malignant pathological parameters such as primary T stage, Lymph node (N) metastasis, and TNM stage. Finally, RKIP and miR-450b-5p served as favorable prognostic indicators, and NRF2 and NQO1 acted as unfavorable prognostic biomarkers in patients with NPC. Collectively, our outcomes reveal that RKIP downregulation promotes radioresistance of NPC by downregulating miR-450b-5p and subsequently upregulating and activating NRF2 and NQO1, highlighting RKIP/miR-450b-5p/NRF2/NQO1 axis as a potential therapeutic target for improving the radiosensitivity of NPC.

MicroRNAs in the regulation of cellular redox status and its implications in myocardial ischemia-reperfusion injury

MicroRNAs (miRNAs) are small RNAs that do not encode for proteins and play key roles in the regulation of gene expression. miRNAs are involved in a comprehensive range of biological processes such as cell cycle control, apoptosis, and several developmental and physiological processes. Oxidative stress can affect the expression levels of multiple miRNAs and, conversely, miRNAs may regulate the expression of redox sensors, alter critical components of the cellular antioxidants, interact with the proteasome, and affect DNA repair systems. The number of publications identifying redox-sensitive miRNAs has increased significantly over the last few years, and some miRNA targets such as Nrf2, SIRT1 and NF-κB have been identified. The complex interplay between miRNAs and ROS is discussed together with their role in myocardial ischemia-reperfusion injury and the potential use of circulating miRNAs as biomarkers of myocardial infarction. Detailed knowledge of redox-sensitive miRNAs is needed to be able to effectively use individual compounds or sets of miRNA-modulating compounds to improve the health-related outcomes associated with different diseases.

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

Background

Previous in vitro studies demonstrated that suppression of microRNAs might protect cardiomyocytes and neurons against oxygen–glucose deprivation and reoxygenation (OGD/R)-induced cell apoptosis. However, whether the protective effect of miR-153-inhibition on cardiomyocytes can be observed in the animal model is unknown. We aimed to address this question using a rat model of ischemia–reperfusion (I/R).

Methods

Rats were received the intramyocardial injection of saline or adenovirus-carrying target or control gene, and the rats were subjected to ischemia/reperfusion (I/R) treatment. The effects of miR-153 on I/R-induced inflammatory response and oxidative stress in the rat model were assessed using various assays.

Results

We found that suppression of miR-153 decreased cleaved caspase-3 and Bcl-2-associated X (Bax) expression, and increased B cell lymphoma 2 (Bcl-2) expression. We further confirmed that Nuclear transcription factor erythroid 2-like 2 (Nrf2) is a functional target of miR-153, and Nrf2/Heme oxygenase-1 (HO-1) signaling was involved in miR-153-regulated I/R-induced cardiomyocytes apoptosis. Inhibition of miR-153 reduced I/R-induced inflammatory response and oxidative stress in rat myocardium.

Conclusion

Suppression of miR-153 exerts a cardioprotective effect against I/R-induced injury through the regulation of Nrf2/HO-1 signaling, suggesting that targeting miR-153, Nrf2, or both may serve as promising therapeutic targets for the alleviation of I/R-induced injury.

miR-155 Knockdown Protects against Cerebral Ischemia and Reperfusion Injury by Targeting MafB

Background

Studies have elucidated that the variable expression levels of miRNAs influence the inflammatory process in ischemic stroke. Nevertheless, the impact and potential mechanism of miR-155 in cerebral ischemia-reperfusion injury (CIRI) keep to be incompletely known.

Methods

The levels of miR-155 and MafB were determined via qRT-PCR, western blot, or immunohistochemistry assays in plasma of patients with CIRI, oxygen glucose deprivation/reoxygenation (OGD/R) induced SH-SY5Y cells, and mouse models with middle cerebral artery occlusion (MCAO). The association between miR-155 and MafB was validated via dual-luciferase reporter and western blot assays. Cell viability, apoptosis, invasion, and migration were evaluated through MTT, flow cytometry, Transwell and wound healing assays. Infarction volume was measured in MCAO mouse brain tissues by TTC assay. The expression of inflammatory mediators was measured by ELISA in cells and brain tissues.

Results

miR-155 level was upregulated whereas MafB was downregulated in the plasma of patients with CIRI, OGD/R-induced SH-SY5Y cells, also as mouse models with MCAO injury. Mechanistically, miR-155 directly targeted 3'UTR of MafB and restrained MafB expression in OGD/R injury SH-SY5Y cells. Downregulation of miR-155 attenuated OGD/R-induced injury through increasing proliferation, inhibiting apoptosis, enhancing invasion and migration abilities, and constraining the expression of inflammatory mediators (IL-1β, IL-6, and TNF-α) and inflammatory enzymes (iNOS and COX-2) in SH-SY5Y cells following OGD/R, while MafB inhibition reversed the protective effects. In vivo, downregulating miR-155 reduced the infarction volume in the MACO mouse brain. Furthermore, miR-155 knockdown inhibited the IL-1β, IL-6, and TNF-α) and inflammatory enzymes (iNOS and COX-2) in SH-SY5Y cells following OGD/R, while MafB inhibition reversed the protective effects.

Conclusion

Our results suggest that miR-155 knockdown alleviated ischemia-reperfusion injury by targeting MafB to improve the neurological function and inhibit inflammation response, highlighting a novel therapeutic strategist for CIRI.