MiR-625-5p Inhibits Cardiac Hypertrophy Through Targeting STAT3 and CaMKII

Clinical significance of miR-625-5p in patients with sepsis-induced acute kidney injury based on bioinformatics analysis

PURPOSE

Sepsis often leads to a cluster of life-threatening symptoms affecting multiple organ systems. Among the organs most vulnerable to damage in this state is the kidney; those afflicted with severe sepsis frequently encounter acute kidney injury (AKI). The study was to investigate the diagnostic role of miR-625-5p in sepsis and sepsis-induced acute kidney injury (SI-AKI) and predict the possible pathways of miR-625-5p involved in SI-AKI by bioinformatics method.

METHODS

RT-qPCR was used to detect the level of miR-625-5p, and the diagnostic value of miR-625-5p was analyzed using ROC curve. The proliferation and the concentration of inflammatory factors of HK-2 cells induced by LPS were detected by CCK-8 and ELISA. The pathway of miR-625-5p involved in SI-AKI was analyzed by bioinformatics method.

RESULTS

The miR-625-5p expression was downregulated in sepsis as well as SI-AKI and has predictive value for sepsis as well as SI-AKI. In addition, miR-625-5p promoted LPS-induced cell proliferation and inhibited the levels of inflammatory cytokines.

CONCLUSION

miR-625-5p may be a diagnostic biomarker for SI-AKI.

Bioinformatics analysis of the microRNA genes associated with type 2 cardiorenal syndrome

BACKGROUND

MicroRNAs (miRNAs) are important regulatory factors in the normal developmental stages of the heart and kidney. However, it is currently unclear how miRNA is expressed in type 2 cardiorenal syndrome (CRS). This study aimed to detect the differential expression of miRNAs and to clarify the main enrichment pathways of differentially expressed miRNA target genes in type 2 CRS.

METHODS

Five cases of healthy control (Group 1), eight of chronic heart failure (CHF, Group 2) and seven of type 2 CRS (Group 3) were enrolled, respectively. Total RNA was extracted from the peripheral blood of each group. To predict the miRNA target genes and biological signalling pathways closely related to type 2 CRS, the Agilent miRNA microarray platform was used for miRNA profiling and bioinformatics analysis of the isolated total RNA samples.

RESULTS

After the microarray analysis was done to screen for differentially expressed circulating miRNAs among the three different groups of samples, the target genes and bioinformatic pathways of the differential miRNAs were predicted. A total of 38 differential miRNAs (15 up- and 23 down-regulated) were found in Group 3 compared with Group 1, and a total of 42 differential miRNAs (11 up- and 31 down-regulated) were found in Group 3 compared to Group 2. According to the Gene Ontology (GO) function and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis, the top 10 lists of molecular functions, cellular composition and biological processes, and the top 30 signalling pathways of predicted gene targets of the differentially expressed miRNAs were discriminated among the three groups.

CONCLUSION

Between the patients with CHF and type 2 CRS, miRNAs were differentially expressed. Prediction of target genes of differentially expressed miRNAs and the use of GO function and KEGG pathway analysis may reveal the molecular mechanisms of CRS. Circulating miRNAs may contribute to the diagnosis of CRS, and further and larger studies are needed to enhance the robustness of our findings.

SLC26A4-AS1 Aggravates AngII-induced Cardiac Hypertrophy by Enhancing SLC26A4 Expression

BACKGROUND

It has been reported that solute carrier family 26 members 4 antisense RNA 1 (SLC26A4-AS1) is highly related to cardiac hypertrophy.

OBJECTIVE

This research aims to investigate the role and specific mechanism of SLC26A4-AS1 in cardiac hypertrophy, providing a novel marker for cardiac hypertrophy treatment.

METHODS

Angiotensin II (AngII) was infused into neonatal mouse ventricular cardiomyocytes (NMVCs) to induce cardiac hypertrophy. Gene expression was detected by quantitative real-time PCR (RT-qPCR). Protein levels were evaluated via western blot. Functional assays analyzed the role of SLC26A4-AS1. The mechanism of SLC26A4-AS1 was assessed by RNA-binding protein immunoprecipitation (RIP), RNA pull-down, and luciferase reporter assays. The P value <0.05 was identified as statistical significance. Student's t-test evaluated the two-group comparison. The difference between different groups was analyzed by one-way analysis of variance (ANOVA).

RESULTS

SLC26A4-AS1 is upregulated in AngII-treated NMVCs and promotes AngII-induced cardiac hypertrophy. SLC26A4-AS1 regulates its nearby gene solute carrier family 26 members 4 (SLC26A4) via functioning as a competing endogenous RNA (ceRNA) to modulate the microRNA (miR)-301a-3p and miR-301b-3p in NMVCs. SLC26A4-AS1 promotes AngII-induced cardiac hypertrophy via upregulating SLC26A4 or sponging miR-301a-3p/miR-301b-3p.

CONCLUSION

SLC26A4-AS1 aggravates AngII-induced cardiac hypertrophy via sponging miR-301a-3p or miR-301b-3p to enhance SLC26A4 expression.

MiR-423-5p Inhibition Exerts Protective Effects on Angiotensin II-Induced Cardiomyocyte Hypertrophy

Angiotensin II (Ang II) is a kind of bioactive peptide, which can contribute to cardiac hypertrophy. MicroRNAs (miRNAs) play critical role in various heart diseases. The cardioprotective effect of miR-423-5p inhibition has been confirmed by previous studies. But its role in cardiac hypertrophy induced by Ang II is unknown. This study focused on the potential of miR-423-5p in cardiomyocyte hypertrophy under the treatment of Ang II. Our results revealed that miR-423-5p expression was upregulated in Ang II-treated human cardiomyocytes (HCMs). Importantly, miR-423-5p knockdown suppressed Ang II-induced cardiomyocyte hypertrophy and oxidative stress in HCMs. Bioinformatics analysis and luciferase reporter assay confirmed that the suppressor of Ty 6 homolog (SUPT6H) was a target gene of miR-423-5p. Interestingly, SUPT6H knockdown aggravated cardiomyocyte hypertrophy and oxidative stress in Ang II-stimulated HCMs, which were then reversed by silenced miR-423-5p. In conclusion, miR-423-5p knockdown exerts its protective effects on Ang II-induced cardiomyocyte hypertrophy in HCMs via modulating SUPT6H expression.

Circulatory miR-411-5p as a Novel Prognostic Biomarker for Major Adverse Cardiovascular Events in Patients with Atrial Fibrillation

The risk stratification of patients with atrial fibrillation (AF) for subsequent cardiovascular events could help in guiding prevention strategies. In this study, we aimed at investigating circulating microRNAs as prognostic biomarkers for major adverse cardiovascular events (MACE) in AF patients. We conducted a three-stage nested case-control study within the framework of a prospective registry, including 347 AF patients. First, total small RNA-sequencing was performed in 26 patients (13 cases with MACE) and the differential expression of microRNAs was analyzed. Seven candidate microRNAs with promising results in a subgroup analysis on cardiovascular death were selected and measured via using RT-qPCR in 97 patients (42 cases with cardiovascular death). To further validate our findings and investigate broader clinical applicability, we analyzed the same microRNAs in a subsequent nested case-control study of 102 patients (37 cases with early MACE) by using Cox regression. In the microRNA discovery cohort (n = 26), we detected 184 well-expressed microRNAs in circulation without overt differential expression between the cases and controls. A subgroup analysis on cardiovascular death revealed 26 microRNAs that were differentially expressed at a significance level < 0.05 (three of which with an FDR-adjusted p-value <0.05). We, therefore, proceeded with a nested case-control approach (n = 97) focusing on patients with cardiovascular death and selected, in total, seven microRNAs for further RT-qPCR analysis. One microRNA, miR-411-5p, was significantly associated with cardiovascular death (adjusted HR (95% CI): 1.95 (1.04-3.67)). Further validation (n = 102) in patients who developed early MACE showed similar results (adjusted HR (95% CI) 2.35 (1.17-4.73)). In conclusion, circulating miR-411-5p could be a valuable prognostic biomarker for MACE in AF patients.

The crosstalk between STAT3 and microRNA in cardiac diseases and protection

Signal transducer and activator of transcription 3 (STAT3), an important transcription factor and signaling molecule, play an important role in cardiac disease and protection. As a transcription factor, STAT3 upregulates anti-oxidative and anti-apoptotic genes but suppresses anti-inflammatory and anti-fibrotic genes in cardiac disease and protection. As a signaling molecule, STAT3 is the downstream or upstream of other molecules for signaling transduction, also activated in cardiac disease and protection. MicroRNAs (miRNAs) are endogenous short non-coding RNAs that regulate mRNA expression at the transcriptional level and prevent protein translation. Recently, STAT3 is reported to be not only the target of miRNA but also the inhibitor or inducer of miRNA to modify the mRNA expression profiles in cardiomyocytes resulting in different effects on cardiac disease and protection. We summarize the current knowledge on STAT3 regulation of individual miRNAs and the modulation of STAT3 by miRNAs in cardiac diseases and protection.

CaMKII inhibitor KN-93 impaired angiogenesis and aggravated cardiac remodelling and heart failure via inhibiting NOX2/mtROS/p-VEGFR2 and STAT3 pathways

Persistent cardiac Ca²⁺/calmodulin‐dependent Kinase II (CaMKII) activation was considered to promote heart failure (HF) development, some studies believed that CaMKII was a target for therapy of HF. However, CaMKII was an important mediator for the ischaemia‐induced coronary angiogenesis, and new evidence confirmed that angiogenesis inhibited cardiac remodelling and improved heart function, and some conditions which impaired angiogenesis aggravated ventricular remodelling. This study aimed to investigate the roles and the underlying mechanisms of CaMKII inhibitor in cardiac remodelling. First, we induced cardiac remodelling rat model by ISO, pre‐treated by CaMKII inhibitor KN‐93, evaluated heart function by echocardiography measurements, and performed HE staining, Masson staining, Tunel staining, Western blot and RT‐PCR to test cardiac remodelling and myocardial microvessel density; we also observed ultrastructure of cardiac tissue with transmission electron microscope. Second, we cultured HUVECs, pre‐treated by ISO and KN‐93, detected cell proliferation, migration, tubule formation and apoptosis, and carried out Western blot to determine the expression of NOX2, NOX4, VEGF, VEGFR2, p‐VEGFR2 and STAT3; mtROS level was also measured. In vivo, we found KN‐93 severely reduced myocardial microvessel density, caused apoptosis of vascular endothelial cells, enhanced cardiac hypertrophy, myocardial apoptosis, collagen deposition, aggravated the deterioration of myocardial ultrastructure and heart function. In vitro, KN‐93 inhibited HUVECs proliferation, migration and tubule formation, and promoted apoptosis of HUVECs. The expression of NOX2, NOX4, p‐VEGFR2 and STAT3 were down‐regulated by KN‐93; mtROS level was severely reduced by KN‐93. We concluded that KN‐93 impaired angiogenesis and aggravated cardiac remodelling and heart failure via inhibiting NOX2/mtROS/p‐VEGFR2 and STAT3 pathways.

Non-Coding RNAs in the Cardiac Action Potential and Their Impact on Arrhythmogenic Cardiac Diseases

Cardiac arrhythmias are prevalent among humans across all age ranges, affecting millions of people worldwide. While cardiac arrhythmias vary widely in their clinical presentation, they possess shared complex electrophysiologic properties at cellular level that have not been fully studied. Over the last decade, our current understanding of the functional roles of non-coding RNAs have progressively increased. microRNAs represent the most studied type of small ncRNAs and it has been demonstrated that miRNAs play essential roles in multiple biological contexts, including normal development and diseases. In this review, we provide a comprehensive analysis of the functional contribution of non-coding RNAs, primarily microRNAs, to the normal configuration of the cardiac action potential, as well as their association to distinct types of arrhythmogenic cardiac diseases.

LncRNA CHRF aggravates myocardial ischemia/reperfusion injury by enhancing autophagy via modulation of the miR-182-5p/ATG7 pathway

Myocardial ischemia/reperfusion (I/R) injury is a very frequent cardiovascular disease and one of the leading causes of death. Abundant evidence has shown that long noncoding RNAs (lncRNAs) are crucial players in myocardial I/R injury. LncRNA cardiac hypertrophy-related factor (CHRF) has been revealed as an important modulator in cardiac disease. However, the function of CHRF in myocardial I/R injury is unclear. In our current work, we found that the expression of CHRF was upregulated in myocardial I/R injury models. Suppression of CHRF relieved myocardial I/R injury in vivo. In addition, in vitro silencing of CHRF enhanced cell viability and attenuated lactate dehydrogenase activity (LDH) as well as apoptosis in H9C2 cells treated with hypoxia/reoxygenation injury. Autophagy has been studied to play an important role in myocardial I/R injury. Thus, experiments related to autophagy were done, and the results showed that CHRF knockdown decreased autophagy. For the exploration of the regulatory mechanism, we found that CHRF sequestered and negatively regulated miR-182-5p to release its inhibition on ATG7. Findings from rescue assays revealed that ATG7 overexpression could suppress the effects of CHRF silence on cell viability, LDH level, apoptosis, and autophagy. To sum up, our results suggested that CHRF exacerbated myocardial I/R injury by enhancing autophagy via modulation of the miR-182-5p/ATG7 pathway. Therefore, this competing endogenous RNA axis may be a potential therapeutic biomarker for myocardial I/R injury.

Pre-clinical investigation of STAT3 pathway in bladder cancer: Paving the way for clinical translation

Effective cancer therapy requires identification of signaling networks and investigating their potential role in proliferation and invasion of cancer cells. Among molecular pathways, signal transducer and activator of transcription 3 (STAT3) has been of importance due to its involvement in promoting proliferation, and invasion of cancer cells, and mediating chemoresistance. In the present review, our aim is to reveal role of STAT3 pathway in bladder cancer (BC), as one of the leading causes of death worldwide. In respect to its tumor-promoting role, STAT3 is able to enhance the growth of BC cells via inhibiting apoptosis and cell cycle arrest. STAT3 also contributes to metastasis of BC cells via upregulating of MMP-2 and MMP-9 as well as genes in the EMT pathway. BC cells obtain chemoresistance via STAT3 overexpression and its inhibition paves the way for increasing efficacy of chemotherapy. Different molecular pathways such as KMT1A, EZH2, DAB2IP and non-coding RNAs including microRNAs and long non-coding RNAs can function as upstream mediators of STAT3 that are discussed in this review article.

The Protective Effect of Qishen Granule on Heart Failure after Myocardial Infarction through Regulation of Calcium Homeostasis

Qishen granule (QSG) is a frequently prescribed traditional Chinese medicine formula, which improves heart function in patients with heart failure (HF). However, the cardioprotective mechanisms of QSG have not been fully understood. The current study aimed to elucidate whether the effect of QSG is mediated by ameliorating cytoplasmic calcium (Ca²⁺) overload in cardiomyocytes. The HF rat model was induced by left anterior descending (LAD) artery ligation surgery. Rats were randomly divided into sham, model, QSG-low dosage (QSG-L) treatment, QSG-high dosage (QSG-H) treatment, and positive drug (diltiazem) treatment groups. 28 days after surgery, cardiac functions were assessed by echocardiography. Levels of norepinephrine (NE) and angiotensin II (AngII) in the plasma were evaluated. Expressions of critical proteins in the calcium signaling pathway, including cell membrane calcium channel CaV1.2, sarcoendoplasmic reticulum ATPase 2a (SERCA2a), calcium/calmodulin-dependent protein kinase type II (CaMKII), and protein phosphatase calcineurin (CaN), were measured by Western blotting (WB) and immunohistochemistry (IHC). Echocardiography showed that left ventricular ejection fraction (EF) and fractional shortening (FS) value significantly decreased in the model group compared to the sham group, and illustrating heart function was severely impaired. Furthermore, levels of NE and AngII in the plasma were dramatically increased. Expressions of CaV1.2, CaMKII, and CaN in the cardiomyocytes were upregulated, and expressions of SERCA2a were downregulated in the model group. After treatment with QSG, both EF and FS values were increased. QSG significantly reduced levels of NE and AngII in the plasma. In particular, QSG prevented cytoplasmic Ca²⁺ overload by downregulating expression of CaV1.2 and upregulating expression of SERCA2a. Meanwhile, expressions of CaMKII and CaN were inhibited by QSG treatment. In conclusion, QSG could effectively promote heart function in HF rats by restoring cardiac Ca²⁺ homeostasis. These findings revealed novel therapeutic mechanisms of QSG and provided potential targets in the treatment of HF.

Analysis of extracellular vesicle miRNA profiles in heart failure

Extracellular vesicles (EVs) have recently emerged as an important carrier for various genetic materials including microRNAs (miRs). Growing evidences suggested that several miRs transported by EVs were particularly involved in modulating cardiac function. However, it has remained unclear what miRs are enriched in EVs and play an important role in the pathological condition. Therefore, we established the miR expression profiles in EVs from murine normal and failing hearts and consecutively identified substantially altered miRs. In addition, we have performed bioinformatics approach to predict potential cardiac outcomes through the identification of miR targets. Conclusively, we observed approximately 63% of predicted targets were validated with previous reports. Notably, the predicted targets by this approach were often involved in both beneficial and malicious signalling pathways, which may reflect heterogeneous cellular origins of EVs in tissues. Lastly, there has been an active debate on U6 whether it is a proper control. Through further analysis of EV miR profiles, miR‐676 was identified as a superior reference control due to its consistent and abundant expressions. In summary, our results contribute to identifying specific EV miRs for the potential therapeutic targets in heart failure and suggest that miR‐676 as a new reference control for the EV miR studies.