MiR-483-3p inhibition ameliorates myocardial ischemia/reperfusion injury by targeting the MDM4/p53 pathway

MicroRNA-483-3p Inhibitor Ameliorates Sepsis-Induced Intestinal Injury by Attenuating Cell Apoptosis and Cytotoxicity Via Regulating HIPK2

Sepsis is a life-threatening syndrome that can result in multi-organ dysfunction. MicroRNA (miR)-483-3p was previously demonstrated to be upregulated in sepsis patients; however, its specific functions in sepsis-triggered intestinal injury remain unclarified. Human intestinal epithelial NCM460 cell line was stimulated with lipopolysaccharide (LPS) to mimic sepsis-induced intestinal injury in vitro. Terminal-deoxynucleotidyl transferase mediated nick end labeling (TUNEL) staining was utilized for examining cell apoptosis. Western blotting and real time quantitative polymerase chain reaction (RT-qPCR) were used for detecting molecular protein and RNA levels. LPS-induced cytotoxicity was determined by measuring concentrations of lactate dehydrogenase (LDH), diamine oxidase (DAO) and fatty acid binding protein 2 (FABP2). Luciferase reporter assay was utilized for verifying the interaction between miR-483-3p and homeodomain interacting protein kinase 2 (HIPK2). Inhibiting miR-483-3p alleviates LPS-triggered NCM460 cell apoptosis and cytotoxicity. miR-483-3p targeted HIPK2 in LPS-stimulated NCM460 cells. Knockdown of HIPK2 reversed the above effects mediated by miR-483-3p inhibitor. Inhibiting miR-483-3p ameliorates LPS-triggered apoptosis and cytotoxicity by targeting HIPK2.

Mechanisms of polydatin against spinal cord ischemia-reperfusion injury based on network pharmacology, molecular docking and molecular dynamics simulation

BACKGROUND

Polydatin has shown considerable pharmacological activities in ischemia-reperfusion injuries of various organs. However, its effects and mechanisms in spinal cord ischemia-reperfusion injury have not been fully established. In this study, the mechanisms of polydatin against spinal cord ischemia-reperfusion injury were investigated via network pharmacology, molecular docking and molecular dynamics simulation.

METHODS

Spinal cord ischemia-reperfusion injury-related targets were obtained from the GeneCards database, while polydatin-related action targets were obtained from the CTD and SwissTarget databases. A protein-protein interaction network of potential targets was constructed using the String platform. After selecting the potential key targets, GO functional enrichment and KEGG pathway enrichment analyses were performed via the Metascape database, and a network map of "drug-target-pathway-disease" constructed. The relationships between polydatin and various key targets were assessed via molecular docking. Molecular dynamics simulation was conducted for optimal core protein-compound complexes obtained by molecular docking.

RESULTS

Topological analysis of the PPI network revealed 14 core targets. GO functional enrichment analysis revealed that 435 biological processes, 12 cell components and 29 molecular functions were enriched while KEGG pathway enrichment analysis revealed 91 enriched signaling pathways. Molecular docking showed that polydatin had the highest binding affinity for MAPK3, suggesting that MAPK3 is a key target of polydatin against spinal cord ischemia-reperfusion injury. Molecular dynamics simulations revealed good binding abilities between polydatin and MAPK3.

CONCLUSIONS

Polydatin exerts its effects on spinal cord ischemia-reperfusion injury through multiple targets and pathways. MAPK3 may be a key target of polydatin in spinal cord ischemia-reperfusion injury.

The Role of P53 in Myocardial Ischemia-Reperfusion Injury

PURPOSE

P53 is one of the key tumor suppressors. In normal cells, p53 is maintained at low levels by the ubiquitination of the ubiquitinated ligase MDM2. In contrast, under stress conditions such as DNA damage and ischemia, the interaction between p53 and MDM2 is blocked and activated by phosphorylation and acetylation, thereby mediating the trans-activation of p53 through its target genes to regulate a variety of cellular responses. Previous studies have shown that the expression of p53 is negligible in normal myocardium, tends to increase in myocardial ischemia and is maximally induced in ischemia-reperfused myocardium, demonstrating a possible key role of p53 in the development of MIRI. In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and describe the therapeutic agents targeting the relevant targets to provide new strategies for the prevention and treatment of MIRI.

METHODS

We collected 161 relevant papers mainly from Pubmed and Web of Science (search terms "p53" and "myocardial ischemia-reperfusion injury"). After that, we selected pathway studies related to p53 and classified them according to their contents. We eventually analyzed and summarized them.

RESULTS AND CONCLUSION

In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and validate its status as an important intermediate affecting MIRI. On the one hand, p53 is regulated and modified by multiple factors, especially non-coding RNAs; on the other hand, p53 regulates apoptosis, programmed necrosis, autophagy, iron death and oxidative stress in MIRI through multiple pathways. More importantly, several studies have reported medications targeting p53-related therapeutic targets. These medications are expected to be effective options for the alleviation of MIRI, but further safety and clinical studies are needed to convert them into clinical applications.

Therapeutic Hypothermia Inhibits Hypoxia-Induced Cardiomyocyte Apoptosis Via the MiR-483-3p/Cdk9 Axis

Background Therapeutic hypothermia has a beneficial effect on cardiac function after acute myocardial infarction, but the exact mechanism is still unclear. Recent research has suggested that microRNAs participate in acute myocardial infarction to regulate cardiomyocyte survival. This study aimed to explore the ability of hypothermia-regulated microRNA-483-3p (miR-483-3p) to inhibit hypoxia-induced myocardial infarction. Methods and Results Primary cardiomyocytes were cultured under hypoxia at 32 °C to mimic therapeutic hypothermia, and the differentially expressed microRNAs were determined by RNA sequencing. Therapeutic hypothermia recovered hypoxia-induced increases in apoptosis, decreases in ATP levels, and decreases in miR-483-3p expression. Overexpression of miR-483-3p exhibited effects similar to those of therapeutic hypothermia on hypoxia in the treatment of cardiomyocytes to associate with maintaining the mitochondrial membrane potential, and cyclin-dependent kinase 9 (Cdk9) was identified as a target gene with downregulated expression by miR-483-3p. Knockdown of Cdk9 also promoted cardiac survival, ATP production, and mitochondrial membrane potential stability under hypoxia. In vivo, the expression of miR-483-3p and Cdk9 was tested in the cardiac tissue of the mice with acute myocardial infarction, and the expression of miR-483-3p decreased and Cdk9 increased in the region of myocardial infarction. However, miR-483-3p was overexpressed with lentivirus, which suppressed apoptosis, infarct size (miR-483-3p, 22.00±4.04% versus negative control, 28.57±5.44%, P<0.05), and Cdk9 expression to improve cardiac contractility. Conclusions MiR-483-3p antagonizes hypoxia, leading to cardiomyocyte injury by targeting Cdk9, which is a new mechanism of therapeutic hypothermia.

FTX Attenuates Cerebral Ischemia-Reperfusion Injury by Inhibiting Apoptosis and Oxidative Stress via miR-186-5p/MDM4 Pathway

LncRNA five prime to Xist (FTX) has been identified to exert a protective effect in multiple diseases. However, whether and how FTX attenuates cerebral ischemia-reperfusion injury (CI/RI) is still unclear. To simulate CI/RI, an in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) HT22 cell model and an in vivo middle cerebral artery occlusion/reperfusion (MCAO/R) Sprague-Dawley rat model were respectively constructed. In CI/RI plasma samples, OGD/R-challenged HT22 cells, and brain tissues from MCAO/R rats, FTX and mouse double minute 4 (MDM4) expressions were substantially decreased while miR-186-5p abundance was evidently increased. It was also revealed that FTX obviously improved neuronal damage induced by OGD/R through increasing proliferation, reducing apoptosis, and alleviating oxidative stress in OGD/R-challenged HT22 cells. Additionally, FTX positively regulated MDM4 level in OGD/R-treated HT22 cells as a sponge of miR-186-5p. Moreover, miR-186-5p upregulation or MDM4 suppression restored the inhibitory effects of FTX upregulation on OGD/R-triggered neuronal damage in HT22 cells. Therefore, these results suggest that FTX might ameliorate CI/RI by regulating the miR-186-5p/MDM4 pathway, providing a new target for stroke impairment treatment.

Non-Coding RNAs: Prevention, Diagnosis, and Treatment in Myocardial Ischemia-Reperfusion Injury

Recent knowledge concerning the role of non-coding RNAs (ncRNAs) in myocardial ischemia/reperfusion (I/R) injury provides new insight into their possible roles as specific biomarkers for early diagnosis, prognosis, and treatment. MicroRNAs (miRNAs) have fewer than 200 nucleotides, while long ncRNAs (lncRNAs) have more than 200 nucleotides. The three types of ncRNAs (miRNAs, lncRNAs, and circRNAs) act as signaling molecules strongly involved in cardiovascular disorders (CVD). I/R injury of the heart is the main CVD correlated with acute myocardial infarction (AMI), cardiac surgery, and transplantation. The expression levels of many ncRNAs and miRNAs are highly modified in the plasma of MI patients, and thus they have the potential to diagnose and treat MI. Cardiomyocyte and endothelial cell death is the major trigger for myocardial ischemia–reperfusion syndrome (MIRS). The cardioprotective effect of inflammasome activation in MIRS and the therapeutics targeting the reparative response could prevent progressive post-infarction heart failure. Moreover, the pharmacological and genetic modulation of these ncRNAs has the therapeutic potential to improve clinical outcomes in AMI patients.

Amniotic Fluid microRNA in Severe Twin-Twin Transfusion Syndrome Cardiomyopathy-Identification of Differences and Predicting Demise

Twin-twin transfusion syndrome (TTTS) is a rare but serious cause of fetal cardiomyopathy with poorly understood pathophysiology and challenging prognostication. This study sought a nonbiased, comprehensive assessment of amniotic fluid (AF) microRNAs from TTTS pregnancies and associations of these miRNAs with clinical characteristics. For the discovery cohort, AF from ten fetuses with severe TTTS cardiomyopathy were selected and compared to ten normal singleton AF. Array panels assessing 384 microRNAs were performed on the discovery cohort and controls. Using a stringent q < 0.0025, arrays identified 32 miRNAs with differential expression. Top three microRNAs were miR-99b, miR-370 and miR-375. Forty distinct TTTS subjects were selected for a validation cohort. RT-PCR targeted six differentially-expressed microRNAs in the discovery and validation cohorts. Expression differences by array were confirmed by RT-PCR with high fidelity. The ability of these miRNAs to predict clinical differences, such as cardiac findings and later demise, was evaluated on TTTS subjects. Down-regulation of miRNA-127-3p, miRNA-375-3p and miRNA-886 were associated with demise. Our results indicate AF microRNAs have potential as a diagnostic and prognostic biomarker in TTTS. The top microRNAs have previously demonstrated roles in angiogenesis, cardiomyocyte stress response and hypertrophy. Further studies of the mechanism of actions and potential targets is warranted.

Impact of the Main Cardiovascular Risk Factors on Plasma Extracellular Vesicles and Their Influence on the Heart's Vulnerability to Ischemia-Reperfusion Injury

The majority of cardiovascular deaths are associated with acute coronary syndrome, especially ST-elevation myocardial infarction. Therapeutic reperfusion alone can contribute up to 40 percent of total infarct size following coronary artery occlusion, which is called ischemia-reperfusion injury (IRI). Its size depends on many factors, including the main risk factors of cardiovascular mortality, such as age, sex, systolic blood pressure, smoking, and total cholesterol level as well as obesity, diabetes, and physical effort. Extracellular vesicles (EVs) are membrane-coated particles released by every type of cell, which can carry content that affects the functioning of other tissues. Their role is essential in the communication between healthy and dysfunctional cells. In this article, data on the variability of the content of EVs in patients with the most prevalent cardiovascular risk factors is presented, and their influence on IRI is discussed.

Roles of noncoding RNAs in the initiation and progression of myocardial ischemia-reperfusion injury

The morbidity and mortality of myocardial ischemia-reperfusion injury (MIRI) have increased in modern society. Noncoding RNAs (ncRNAs), including lncRNAs, circRNAs, piRNAs and miRNAs, have been reported in a variety of studies to be involved in pathological initiation and developments of MIRI. Hence this review focuses on the current research regarding these ncRNAs in MIRI. We comprehensively introduce the important features of lncRNAs, circRNAs, piRNA and miRNAs and then summarize the published studies of ncRNAs in MIRI. A clarification of lncRNA-miRNA-mRNA, lncRNA-transcription factor-mRNA and circRNA-miRNA-mRNA axes in MIRI follows, to further elucidate the crucial roles of ncRNAs in MIRI. Bioinformatics analysis has revealed the biological correlation of mRNAs with MIRI. We provide a comprehensive perspective for the roles of these ncRNAs and their related networks in MIRI, providing a theoretical basis for preclinical and clinical studies on ncRNA-based gene therapy for MIRI treatment.

Involvement of non‑coding RNAs in the pathogenesis of myocardial ischemia/reperfusion injury (Review)

Myocardial ischemia/reperfusion injury (MIRI) may cause myocardial stunning, reperfusion arrhythmia, no‑reflow phenomenon and lethal reperfusion injury, which has a significant effect on the prognosis of patients undergoing thrombolytic agent therapy and percutaneous coronary intervention. Increasing evidence suggests that apoptosis, innate inflammation, oxidative stress, calcium overload and autophagy are involved in the pathogenesis of MIRI. Recent advancements in RNA sequencing technologies and genome‑wide analyses led to the finding of small non‑coding RNAs (ncRNAs). ncRNAs modulate cellular processes such as signal transduction, transcription, chromatin remodeling and post‑transcriptional modification. The effects of ncRNAs on cellular biology is more considerable than initially expected, and thus ncRNAs have gained increasing attention and focus in modern medical research. There are several types of ncRNAs, such as microRNAs (miRNAs), long non‑coding RNAs (lncRNAs) and circular RNAs (circRNAs), which have been shown to regulate gene expression at the transcription, post‑transcription and epigenetic levels. Dysregulation of ncRNAs, including miRNAs, lncRNAs and circRNAs, may participate in the molecular mechanisms of MIRI. The present review summarizes the characteristics and biological roles of miRNAs, lncRNAs and circRNAs, with particular emphasis on their role in MIRI, which show the novel complexity of ischemic hearts and may offer valuable insights into the pathogenesis of MIRI.