Role and mechanism of the lncRNA SNHG1/miR‑450b‑5p/IGF1 axis in the regulation of myocardial ischemia reperfusion injury

Sevoflurane Mediates LINC00339/miR-671-5p/PSMB2 Axis to Improve Cardiomyocytes Against Hypoxia/Reoxygenation Injury

Ischemia/reperfusion (I/R) causes a deterioration in heart function, leading to myocardial infarction. It is aimed at investigating the protective mechanism of sevoflurane (Sevo) on cardiomyocytes by constructing a cellular model of hypoxic/reoxygenation (H/R) in this study.[Human hybrid] epithelioid cells (AC16) were induced by H/R to establish a model of myocardial I/R injury and Sevo postconditioning. The expression of long intergenic non-protein coding RNA 339 (LINC00339), microRNA-671-5p (miR-671-5p) and proteasome 20S subunit beta 2 (PSMB2) was detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Viability and apoptosis of AC16 cells were detected by cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. The levels of interleukin-6 (IL-6), IL-10, tumor necrosis factor-a (TNF-a), reactive oxygen species (ROS), malondialdehyde (MDA), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD), were detected. LINC00339 expression was upregulated in H/R cardiomyocytes relative to the Control group, whereas Sevo decreased LINC00339 expression in H/R cardiomyocytes. The viability of AC16 cells were increased, and apoptosis, oxidative stress, and inflammatory responses decreased in the Sevo postconditioning group relative to the H/R group, but the protective effect of Sevo on H/R cardiomyocytes was partially reversed by LINC00339 overexpression. LINC00339 negatively regulated miR-671-5p, and miR-671-5p upregulation could alleviate the damage of LINC00339 on H/R cardiomyocytes. PSMB2, a downstream target gene of miR-671-5p, could inhibit the protective effect of Sevo on H/R cardiomyocytes. Sevo postconditioning exerts a protective effect in H/R-induced cardiomyocyte injury, which may be achieved by interfering with LINC00339/miR-671-5p/PSMB2 expression.

Upregulation of miRNA-450b-5p targets ACTB to affect drug resistance and prognosis of ovarian cancer via the PI3K/Akt signaling pathway

Background

Ovarian cancer (OC) is the most malignant gynecologic cancer, and chemoresistance is a major cause of treatment failure in patients with OC. The understanding of microRNA (miRNA) in cancer is limited, and the role of miRNA (miR)-450b-5p in cancer drug resistance is unknown. In this study, we aim to evaluate the role of miR-450b-5p in drug-resistant OC and its underlying mechanisms.

Methods

MiR-450b-5p expression was assessed in drug-sensitive and resistant OC cells via quantitative real-time polymerase chain reaction. Cell viability was evaluated using the Cell Counting Kit-8 assay. Progression-free survival (PFS) and overall survival (OS) curves were generated using the Kaplan-Meier method and the log-rank test. Target genes of miR-450b-5p were identified from the Cancer MIRNome database. Co-expressed genes were obtained from The Cancer Genome Atlas and Cancer Genome cBioportal for pathway enrichment and functional clustering analysis.

Results

The miRNA-450b-5p expression was significantly increased in A2780 and SKOV3 OC-resistant cells and significantly increased by 17-fold in the A2780-CBP-Lv-miR-450b-5p cells compared to A2780-CBP and A2780-CBP-Lv-NC cells. The up-regulated expression of miR-450b-5p increased the cell viability and half maximal inhibitory concentration (IC50) of A2780 platinum-resistant cells and was associated with poor OS. We obtained 33 potential target genes of miR-450b-5p and beta-actin (ACTB) might be a potential target of miR-450b-5p. Low expression of ACTB predicted poor OS and PFS. We obtained 362 common genes co-expressed with ACTB, which involved 4 critical pathways. PI3K acted as an upstream pathway of the other three pathways, which ultimately responded to drug resistance regulation in OC. The genes enriched in four pathways were cross-analyzed and 13 overlapping genes were obtained. These 13 genes were also significantly and positively co-expressed with ACTB at both protein and mRNA levels.

Conclusions

High expression of miRNA-450b-5p might affect drug resistance and prognosis in OC by targeting 13 co-expressed genes of ACTB directly through the PI3K/Akt signaling pathway. Thus, miR-450b-5p might provide a new therapeutic target for drug resistance in OC.

WTAP-mediated m6A modification of lncRNA Snhg1 improves myocardial ischemia-reperfusion injury via miR-361-5p/OPA1-dependent mitochondrial fusion

BACKGROUND

Myocardial ischemia-reperfusion injury (MIRI) is caused by reperfusion after ischemic heart disease. LncRNA Snhg1 regulates the progression of various diseases. N6-methyladenosine (m6A) is the frequent RNA modification and plays a critical role in MIRI. However, it is unclear whether lncRNA Snhg1 regulates MIRI progression and whether the lncRNA Snhg1 was modified by m6A methylation.

METHODS

Mouse cardiomyocytes HL-1 cells were utilized to construct the hypoxia/reoxygenation (H/R) injury model. HL-1 cell viability was evaluated utilizing CCK-8 method. Cell apoptosis, mitochondrial reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) were quantitated utilizing flow cytometry. RNA immunoprecipitation and dual-luciferase reporter assays were applied to measure the m6A methylation and the interactions between lncRNA Snhg1 and targeted miRNA or target miRNAs and its target gene. The I/R mouse model was constructed with adenovirus expressing lncRNA Snhg1. HE and TUNEL staining were used to evaluate myocardial tissue damage and apoptosis.

RESULTS

LncRNA Snhg1 was down-regulated after H/R injury, and overexpressed lncRNA Snhg1 suppressed H/R-stimulated cell apoptosis, mitochondrial ROS level and polarization. Besides, lncRNA Snhg1 could target miR-361-5p, and miR-361-5p targeted OPA1. Overexpressed lncRNA Snhg1 suppressed H/R-stimulated cell apoptosis, mitochondrial ROS level and polarization though the miR-361-5p/OPA1 axis. Furthermore, WTAP induced lncRNA Snhg1 m6A modification in H/R-stimulated HL-1 cells. Moreover, enforced lncRNA Snhg1 repressed I/R-stimulated myocardial tissue damage and apoptosis and regulated the miR-361-5p and OPA1 levels.

CONCLUSION

WTAP-mediated m6A modification of lncRNA Snhg1 regulated MIRI progression through modulating myocardial apoptosis, mitochondrial ROS production, and mitochondrial polarization via miR-361-5p/OPA1 axis, providing the evidence for lncRNA as the prospective target for alleviating MIRI progression.

Insulin-like growth factor-1 in myocardial ischemia-reperfusion injury: A review

Myocardial ischemia-reperfusion injury (MIRI) is a severe damage inflicted on the ischemic myocardium when blood flow is restored, and it commonly occurs in a wide range of cardiovascular diseases. Presently, no effective clinical treatment exists for MIRI. Accumulating evidence indicates that insulin-like growth factor-1 (IGF-1) plays a role in the intricate chain of cardiovascular events, in addition to its well-recognized growth-promoting and metabolic effects. IGF-1, a member of the insulin family, exhibits a broad spectrum of protective effects against ischemia/reperfusion injury in various tissues, especially the myocardium. In particular, earlier research has demonstrated that IGF-1 reduces cellular oxidative stress, improves mitochondrial function, interacts with noncoding RNAs, and activates cardiac downstream protective genes and protective signaling channels. This review aimed to summarize the role of IGF-1 in MIRI and elucidate its related mechanisms of action. In addition, IGF-1-related interventions for MIRI, such as ischemic preconditioning and post-conditioning, were discussed. The purpose of this review was to provide evidence supporting the activation of IGF-1 in MIRI and advocate its use as a therapeutic target.

Characterization of lncRNA-associated ceRNA network to uncover novel potential biomarkers in coronary artery disease

The purpose of this study was to construct a competitive endogenous RNA (ceRNA) network related to long non-coding RNA (lncRNAs) via the bioinformatics analysis, reveal the pathogenesis of coronary heart disease (CAD) and develop new biomarkers for CAD. The gene expression datasets of peripheral blood of CAD were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed mRNAs, miRNAs and lncRNAs (DEmRNAs, DEmiRNAs and DElncRNAs) were identified. Subsequently, a ceRNA network involving lncRNAs, miRNAs, and mRNAs was built. Moreover, DElncRNAs in the cytoplasm were screened and a DElncRNA-associated ceRNA network was established. In total, 1860 DEmRNAs, 393 DElncRNAs and 20 DEmiRNAs were filtrated in patients with CAD compared with normal controls. Functional analysis suggested that DEmRNAs significantly enriched in CAD-related pathways, such as PI3K-Akt signaling pathways and MAPK signaling pathway. The ceRNA network contained 12 DEmiRNAs, 30 DElncRNAs and 537 DEmRNAs. Afterwards, the cytoplasm ceRNA network was consisted of 537 DEmRNAs, 12 DEmiRNAs and 12 DElncRNAs. Such as, up-regulated LncRNA-HOX transcript antisense RNA (HOTAIR) was interacted with down-regulated has-miR-326 and has-miR-1. The successful construction of lncRNA-associated ceRNA network is helpful to better clarify the pathogenesis of CAD and provide potential peripheral blood biomarkers for CAD.

The role of PI3K/AKT signaling pathway in myocardial ischemia-reperfusion injury

Myocardial ischemia has a high incidence and mortality rate, and reperfusion is currently the standard intervention. However, reperfusion may lead to further myocardial damage, known as myocardial ischemia/reperfusion injury (MIRI). There are currently no effective clinical treatments for MIRI. The PI3K/Akt signaling pathway is involved in cardiovascular health and disease and plays an important role in reducing myocardial infarct size and restoring cardiac function after MIRI. Activation of the PI3K/Akt pathway provides myocardial protection through synergistic upregulation of antioxidant, anti-inflammatory, and autophagy activities and inhibition of mitochondrial dysfunction and cardiomyocyte apoptosis. Many studies have shown that PI3K/Akt has a significant protective effect against MIRI. Here, we reviewed the molecular regulation of PI3K/Akt in MIRI and summarized the molecular mechanism by which PI3K/Akt affects MIRI, the effects of ischemic preconditioning and ischemic postconditioning, and the role of related drugs or activators targeting PI3K/Akt in MIRI, providing novel insights for the formulation of myocardial protection strategies. This review provides evidence of the role of PI3K/Akt activation in MIRI and supports its use as a therapeutic target.

EGCG attenuated acute myocardial infarction by inhibiting ferroptosis via miR-450b-5p/ACSL4 axis

BACKGROUND

Epigallocatechin gallate (EGCG) has multiple biological effects such as anti-tumor multiple drug resistance, antioxidation and anti-inflammatory properties. Ferroptosis is the main driving factor of ischemic heart injury, thus inhibiting ferroptosis may prove to be an effective treatment strategy for cardiovascular diseases. However, the role of EGCG on ferroptosis in ischemic myocardium and underlying mechanisms remain uncertain.

PURPOSE

This study was aimed to investigate the effects and potential mechanisms of EGCG on myocardial ischemic-induced ferroptosis both in vitro and in vivo.

METHODS

Cardiomyocyte hypoxia model and mouse acute myocardial infarction (AMI) model were established in vitro and in vivo. MiR-450b-5p and ACSL4 silencing or overexpression plasmids were transfected, with or without EGCG pretreatment. Cell viability was determined by the CCK-8 assay. Hematoxylin and eosin (HE) staining and transmission electron microscopy (TEM) were used to evaluate the morphologic alterations. TTC staining was used to observe the infarction area, and echocardiography was adopted to appraise the heart function. Using flow cytometry, the presence of reactive oxygen species (ROS) was assessed. The content of cardiac troponin I (cTn I), glutathione (GSH), malondialdehyde (MDA), divalent iron ions (Fe2+) and superoxide dismutase (SOD) were detected using reagent kits. A luciferase activity assay was performed to assess the binding ability of miR-450b-5p to ACSL4. Expressions of related genes and proteins were measured by RT-qPCR and western blotting respectively.

RESULTS

EGCG attenuated AMI-induced ferroptosis and improved myocardial ischemia injury, which was associated with reducing iron deposition and cTn I, inhibition of lipid peroxidation, decreasing TFR1 and ACSL4, and upregulating SLC7A11, FTH1 and GPX4. Meanwhile, EGCG pretreatment increased miR-450b-5p expression in ischemic myocardium. Further researches discovered that knockdown of miR-450b-5p partially compromised EGCG-generated protective effect in hypoxia HL-1 cells, while combination with miR-450b-5p mimic could strengthen the potency of EGCG on ischemic myocardium. The dual-luciferase test demonstrated that miR-450b-5p has binding to ACSL4. Furthermore, silencing of ACSL4 synergistically increased the cardioprotective effect of EGCG. More significantly, EGCG treatment regulated the ferroptosis-related proteins expression via miR-450b-5p/ACSL4 axis.

CONCLUSION

In summary, the present study evidently demonstrated that EGCG attenuates myocardial ischemia injury by targeting ferroptosis. Our work revealed the role of miR-450b-5p/ACSL4 axis in AMI for the first time. Further, it also elucidated the molecular mechanisms of EGCG on inhibiting ferroptosis greatly depend on the miR-450b-5p/ACSL4 axis, suggesting that EGCG may act as a novel anti-ferroptosis agent and exert a therapeutic role in AMI.

Mechanism of Resveratrol Improving Ischemia-Reperfusion Injury by Regulating Microglial Function Through microRNA-450b-5p/KEAP1/Nrf2 Pathway

Alterations in the M1/M2 polarization phenotype significantly affect disease progression. Antioxidant and anti-inflammatory protective effects of resveratrol (Res) have been demonstrated. This paper tested the hypothesis that Res could protect against cerebral ischemia-reperfusion injury (CI/RI) by modulating microglial polarization via the miR-450b-5p/KEAP1/Nrf2 pathway. Rats were first treated with Res and adenovirus that interfered with miR-450b-5p or KEAP1, and then established a middle cerebral artery occlusion-reperfusion model using modified nylon sutures. Rats were then evaluated for neurological and behavioral functions, and markers of M2 microglia were detected by immunofluorescence staining. Additionally, the signature patterns of miR-450b-5p, KEAP1, and Nrf2 were determined. The collected data demonstrated that Res exerted neuroprotective effects in CI/RI by promoting microglial M2 polarization. Additionally, Res could regulate the Nrf2 pathway by targeting KEAP1 by up-regulating miR-450b-5p. Up-regulating miR-450b-5p or down-regulating KEAP1 could further promote the protective effect of Res, while down-regulating miR-450b-5p or up-regulating KEAP1 worked oppositely. Our study demonstrates that Res exerts neuroprotective effects on microglial M2 polarization through the miR-450b-5p/KEAP1/Nrf2 pathway during CI/RI.

The emerging role of long noncoding RNA in depression and its implications in diagnostics and therapeutic responses

Depression is one of the most common mental illnesses, affecting more than 350 million people worldwide. However, the occurrence of depression is a complex process involving genetic, physiological, psychological, and social factors, and the underlying mechanisms of its pathogenesis remain unclear. With advances in sequencing technology and epigenetic studies, increasing research evidence suggests that long noncoding RNAs (lncRNAs) play nonnegligible roles in the development of depression and may be involved in the pathogenesis of depression through multiple pathways, including regulating neurotrophic factors and other growth factors and affecting synaptic function. In addition, significant alterations in lncRNA expression profiles in peripheral blood and different brain regions of patients and model animals with depression suggest that lncRNAs may function as biomarkers for the differential diagnosis of depression and other psychiatric disorders and may also be potential therapeutic targets. In this paper, the biological functions of lncRNAs are briefly described, and the functional roles and abnormal expression of lncRNAs in the development, diagnosis and treatment of depression are reviewed.

Noncoding RNAs as Key Regulators for Cardiac Development and Cardiovascular Diseases

Noncoding RNAs (ncRNAs) play fundamental roles in cardiac development and cardiovascular diseases (CVDs), which are a major cause of morbidity and mortality. With advances in RNA sequencing technology, the focus of recent research has transitioned from studies of specific candidates to whole transcriptome analyses. Thanks to these types of studies, new ncRNAs have been identified for their implication in cardiac development and CVDs. In this review, we briefly describe the classification of ncRNAs into microRNAs, long ncRNAs, and circular RNAs. We then discuss their critical roles in cardiac development and CVDs by citing the most up-to-date research articles. More specifically, we summarize the roles of ncRNAs in the formation of the heart tube and cardiac morphogenesis, cardiac mesoderm specification, and embryonic cardiomyocytes and cardiac progenitor cells. We also highlight ncRNAs that have recently emerged as key regulators in CVDs by focusing on six of them. We believe that this review concisely addresses perhaps not all but certainly the major aspects of current progress in ncRNA research in cardiac development and CVDs. Thus, this review would be beneficial for readers to obtain a recent picture of key ncRNAs and their mechanisms of action in cardiac development and CVDs.

Noncoding RNA actions through IGFs and IGF binding proteins in cancer

The insulin-like growth factors (IGFs) and their regulatory proteins—IGF receptors and binding proteins—are strongly implicated in cancer progression and modulate cell survival and proliferation, migration, angiogenesis and metastasis. By regulating the bioavailability of the type-1 IGF receptor (IGF1R) ligands, IGF-1 and IGF-2, the IGF binding proteins (IGFBP-1 to -6) play essential roles in cancer progression. IGFBPs also influence cell communications through pathways that are independent of IGF1R activation. Noncoding RNAs (ncRNAs), which encompass a variety of RNA types including microRNAs (miRNAs) and long-noncoding RNAs (lncRNAs), have roles in multiple oncogenic pathways, but their many points of intersection with IGF axis functions remain to be fully explored. This review examines the functional interactions of miRNAs and lncRNAs with IGFs and their binding proteins in cancer, and reveals how the IGF axis may mediate ncRNA actions that promote or suppress cancer. A better understanding of the links between ncRNA and IGF pathways may suggest new avenues for prognosis and therapeutic intervention in cancer. Further, by exploring examples of intersecting ncRNA-IGF pathways in non-cancer conditions, it is proposed that new opportunities for future discovery in cancer control may be generated.