MiR-499 inhibited hypoxia/reoxygenation induced cardiomyocytes injury by targeting SOX6

Role of miRNA in Cardiovascular Diseases in Children-Systematic Review

The number of children suffering from cardiovascular diseases (CVDs) is rising globally. Therefore, there is an urgent need to acquire a better understanding of the genetic factors and molecular mechanisms related to the pathogenesis of CVDs in order to develop new prevention and treatment strategies for the future. MicroRNAs (miRNAs) constitute a class of small non-coding RNA fragments that range from 17 to 25 nucleotides in length and play an essential role in regulating gene expression, controlling an abundance of biological aspects of cell life, such as proliferation, differentiation, and apoptosis, thus affecting immune response, stem cell growth, ageing and haematopoiesis. In recent years, the concept of miRNAs as diagnostic markers allowing discrimination between healthy individuals and those affected by CVDs entered the purview of academic debate. In this review, we aimed to systematise available information regarding miRNAs associated with arrhythmias, cardiomyopathies, myocarditis and congenital heart diseases in children. We focused on the targeted genes and metabolic pathways influenced by those particular miRNAs, and finally, tried to determine the future of miRNAs as novel biomarkers of CVD.

Integrated Analysis of lncRNA-miRNA-mRNA Regulatory Network in Rapamycin-Induced Cardioprotection against Ischemia/Reperfusion Injury in Diabetic Rabbits

The inhibition of mammalian target of rapamycin (mTOR) with rapamycin (RAPA) provides protection against myocardial ischemia/reperfusion (I/R) injury in diabetes. Since interactions between transcripts, including long non-coding RNA (lncRNA), microRNA(miRNA) and mRNA, regulate the pathophysiology of disease, we performed unbiased miRarray profiling in the heart of diabetic rabbits following I/R injury with/without RAPA treatment to identify differentially expressed (DE) miRNAs and their predicted targets of lncRNAs/mRNAs. Results showed that among the total of 806 unique miRNAs targets, 194 miRNAs were DE after I/R in diabetic rabbits. Specifically, eight miRNAs, including miR-199a-5p, miR-154-5p, miR-543-3p, miR-379-3p, miR-379-5p, miR-299-5p, miR-140-3p, and miR-497-5p, were upregulated and 10 miRNAs, including miR-1-3p, miR-1b, miR-29b-3p, miR-29c-3p, miR-30e-3p, miR-133c, miR-196c-3p, miR-322-5p, miR-499-5p, and miR-672-5p, were significantly downregulated after I/R injury. Interestingly, RAPA treatment significantly reversed these changes in miRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated the participation of miRNAs in the regulation of several signaling pathways related to I/R injury, including MAPK signaling and apoptosis. Furthermore, in diabetic hearts, the expression of lncRNAs, HOTAIR, and GAS5 were induced after I/R injury, but RAPA suppressed these lncRNAs. In contrast, MALAT1 was significantly reduced following I/R injury, with the increased expression of miR-199a-5p and suppression of its target, the anti-apoptotic protein Bcl-2. RAPA recovered MALAT1 expression with its sponging effect on miR-199-5p and restoration of Bcl-2 expression. The identification of novel targets from the transcriptome analysis in RAPA-treated diabetic hearts could potentially lead to the development of new therapeutic strategies for diabetic patients with myocardial infarction.

MicroRNA-499-5p inhibits transforming growth factor-β1-induced Smad2 signaling pathway and suppresses fibroblast proliferation and collagen synthesis in rat by targeting TGFβ-R1

BACKGROUND

Artial fibrosis has been recognized as a typical pathological change in atrial fibrillation. Although present evidence suggests that microRNA-499-5p (miR-499-5p) plays an important role in the development of atrial fibrosis, the specific mechanism is not fully understood. Therefore, this study attempted to assess the influence of miR-499-5p on atrial fibroblasts and explore the potential molecular mechanism.

METHODS

Atrial fibroblasts from sprague dawley rat were respectively transfected with miR-499-5p mimic, miR-499-5p negative control and miR-499-5p inhibitor, atrial fibroblasts without any treatment were also established. Cell counting kit-8 assay and transwell assay were used to detect the proliferation and migration of atrial fibroblasts in each group. Expressions of miR-499-5p, TGF-β1, smad2, α-SMA, collagen-I and TGFβ-R1 in mRNA and protein level were subsequently detected via quantitative real-time polymerase chain reaction and western blot. Furthermore, the prediction of the binding sites of miR-499-5p and TGFβ-R1 was performed via the bioinformatics online software TargetScan and verified by dual luciferase reporter.

RESULTS

By utilizing miR-499-5p-transfected atrial fibroblasts model, expression of miR-499-5p in the miR-499-5p mimic group was upregulated, while it was downregulated in the miR-499-5p inhibitors group. Upregulated miR-499-5p expression led to to a significant decrease in the proliferative and migratory ability of cultured atrial fibroblasts, while downregulated miR-499-5p expression led to a significant increase in the proliferative and migratory ability of cultured atrial fibroblasts. Additionally, upregulated miR-499-5p expression made a significant rise in TGF-β1-induced mRNA and protein expression of TGF-β1, TGFβ-R1, smad2, α-SMA and collagen-I in atrial fibroblasts. Furthermore, results from the dual luciferase reporter conformed that miR-499-5p may repress TGFβ-R1 by binding the 3'UTR of TGFβ-R1 directly.

CONCLUSIONS

miR-499-5p is able to inhibit the activation of transforming growth factor β-induced Smad2 signaling and eventually suppressed the proliferation, migration and invasion of atrial fibroblasts and collagen synthesis by targeting TGFβ-R1.

Inhibition of miR-195-3p protects against cardiac dysfunction and fibrosis after myocardial infarction

Cardiac fibrosis following myocardial infarction is a major risk factor for heart failure. Recent evidence suggests that miR-195-3p is up-regulated in fibrotic diseases, including kidney and liver fibrosis. However, its function and underlying mechanisms in cardiac fibrosis after MI remain unknown. To investigate the role of miR-195-3p in MI-induced cardiac fibrosis, we established acute MI models by ligating adult C57B/L6 mice LAD coronary artery while sham-operated mice were used as controls. In vivo inhibition of miR-195-3p was conducted by intramyocardial injection of AAV9-anti-miR-195-3p. In vitro overexpression and inhibition of miR-195-3p were performed by transfecting cultured Cardiac Fibroblasts (CFs) with synthetic miRNA mimic and inhibitor. Our results showed that MI induced the expression of miR-195-3p and that inhibition of miR-195-3p reduced myofibroblast differentiation and collagen deposition and protected cardiac function. In vitro stimulation of CFs with TGF-β1 resulted in a significant increase in miR-195-3p expression. Inhibition of miR-195-3p attenuated the TGF-β1-induced expression of ECM proteins, migration, and proliferation. PTEN expression was significantly reduced in the hearts of MI mice, in activated CFs, and in CFs transfected with miR-195-3p mimic. Inhibition of miR-195-3p markedly restored PTEN expression in MI mice and TGF-β1-treated CFs. In conclusion, this study highlights the crucial role of miR-195-3p in promoting cardiac fibrosis and dysfunction after MI. Inhibiting miR-195-3p could be a promising therapeutic strategy for preventing cardiac fibrosis and preserving cardiac function after MI. Additionally, the study sheds light on the mechanisms underlying the effects of miR-195-3p on fibrosis, including its regulation of PTEN/AKT pathway.

Rapid diagnosis of acute myocardial infarction based on reverse transcription-accelerated strand exchange amplification of miR-208a

Acute myocardial infarction (AMI) is a prevalent cardiovascular disease associated with high morbidity and mortality, posing a significant threat to human health. Therefore, early diagnosis of AMI has become a focal point of research. MiR-208 is specifically expressed in the heart and is involved in the regulation of cardiomyocyte hypertrophy, cardiac fibrosis, and other myocardial gene expressions. It is expected to be applied in the clinical detection of AMI due to its release by damaged myocardial cells within 3 hours of AMI. In this study, we developed a denatured bubble-mediated reverse transcription-accelerated strand exchange amplification (RT-ASEA) method to detect the early biomarker miR-208a of AMI. The novel approach allowed rapid amplification of miR-208a in 15 minutes, with good performance in terms of repeatability (CV < 6%), determination limit (1 × 100 pmol L-1), and linearity (R2 = 0.9690). Based on the analysis of 42 clinical samples, a strong correlation was observed between the Ct value of miR-208a detected by the RT-ASEA method and the cTnI concentration, considered the gold standard for diagnosis of AMI. The research suggested that the RT-ASEA method could be applied to distinguish between AMI and healthy groups. The area under the receiver operating characteristic curve (AUC) was 0.9976, with a sensitivity of 96% and a specificity of 100%. Optimized RT-ASEA is a reliable and efficient method for miRNA detection. Furthermore, this study provides crucial data support for the development of miR-208a as an early biomarker for AMI, which is of great significance in life and health.

MicroRNA profiling of the feline left heart identifies chamber-specific expression signatures in health and in advanced hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is a common heart disease in humans and cats, nonetheless, the disease pathogenesis is still poorly understood. MicroRNAs are suspected to be involved in the disease process but the myocardial microRNA expression pattern in cats has not been identified. We hypothesized that microRNA profiles differ between healthy cats and cats with HCM. Small RNA sequencing on left ventricle (LV) and left atria (LA) samples from healthy cats (8 LV, 8 LA) and cats with HCM (7 LV, 5 LA) was performed. We identified 1039 differentially expressed microRNAs (False Discovery Rate <0.01, fold change >2). Cats with HCM were found to have a distinct microRNA expression profile with apparent regional heterogeneity. Comparing the HCM and control hearts, we detected 80 differentially expressed microRNAs for the HCM LV, and 37 for the LA. These included LV and LA enriched miR-21, miR-146b, and reduced miR-122-5p, which were recently suggested as key microRNAs for the HCM pathogenesis, and miR-132, which might be of therapeutic interest. Several top enriched microRNAs: miR-3958, miR-382-5p, miR-487a-5p (HCM LV); miR-chrD4_30107-3p (HCM LA); miR-3548 (HCM LV and LA) have either not been reported in the heart or only little is known. We identified potentially relevant microRNAs and further investigations into their role are required. Genes known to be targeted by the differentially expressed microRNAs were associated with inflammation and growth pathways in the HCM LV and LA, cardioprotective pathways in the LV, and fibrosis and structural changes in the LA when compared to healthy hearts.

New Insight into Mechanisms of Cardiovascular Diseases: An Integrative Analysis Approach to Identify TheranoMiRNAs

MiRNAs regulate both physiological and pathological heart functions. Altered expression of miRNAs is associated with cardiovascular diseases (CVDs), making miRNAs attractive therapeutic strategies for the diagnosis and treatment of heart diseases. A recent publication defined, for the first time, the term theranoMiRNA, meaning the miRNAs that may be used both for diagnosis and treatment. The use of in silico tools may be considered fundamental for these purposes, clarifying several molecular aspects, suggesting future directions for in vivo studies. This study aims to explore different bioinformatic tools in order to clarify miRNA interactions with candidate genes, demonstrating the need to use a computational approach when establishing the most probable associations between miRNAs and target genes. This study focused on the functions of miR-133a-3p, miR-21-5p, miR-499a-5p, miR-1-3p, and miR-126-3p, providing an up-to-date overview, and suggests future lines of research in the identification of theranoMiRNAs related to CVDs. Based on the results of the present study, we elucidated the molecular mechanisms that could be linked between miRNAs and CVDs, confirming that these miRNAs play an active role in the genesis and development of heart damage. Given that CVDs are the leading cause of death in the world, the identification of theranoMiRNAs is crucial, hence the need for a definition of in vivo studies in order to obtain further evidence in this challenging field of research.

miRNA Dysregulation in Cardiovascular Diseases: Current Opinion and Future Perspectives

MicroRNAs (miRNAs), small noncoding RNAs, are post-transcriptional gene regulators that can promote the degradation or decay of coding mRNAs, regulating protein synthesis. Many experimental studies have contributed to clarifying the functions of several miRNAs involved in regulatory processes at the cardiac level, playing a pivotal role in cardiovascular disease (CVD). This review aims to provide an up-to-date overview, with a focus on the past 5 years, of experimental studies on human samples to present a clear background of the latest advances to summarize the current knowledge and future perspectives. SCOPUS and Web of Science were searched using the following keywords: (miRNA or microRNA) AND (cardiovascular diseases); AND (myocardial infarction); AND (heart damage); AND (heart failure), including studies published from 1 January 2018 to 31 December 2022. After an accurate evaluation, 59 articles were included in the present systematic review. While it is clear that miRNAs are powerful gene regulators, all the underlying mechanisms remain unclear. The need for up-to-date data always justifies the enormous amount of scientific work to increasingly highlight their pathways. Given the importance of CVDs, miRNAs could be important both as diagnostic and therapeutic (theranostic) tools. In this context, the discovery of “TheranoMIRNAs” could be decisive in the near future. The definition of well-setout studies is necessary to provide further evidence in this challenging field.

MiR-19b-3p Inhibits Hypoxia-Ischemia Encephalopathy by Inhibiting SOX6 Expression via Activating Wnt/β-catenin Pathway

Hypoxic-ischemic encephalopathy (HIE) is a detrimental factor in infant death and chronic disease. The specific pathogenesis is not entirely clear. Therefore, exploring the pathogenesis of HIE is critical. The expression of miR-19b-3p and SOX6 in umbilical blood of HIE patients was detected by qRT-PCR assay. HT22 cells were triggered with oxygen-glucose deprivation/reoxygenation (OGD/R) to construct the HIE cell model. Cell Counting Kit-8 (CCK-8) assay was used to estimate viability. SOD and MDA levels were detected by enzyme linked immunosorbent assay. Flow cytometry was implemented to ascertain neurocyte apoptosis. Cellular β-catenin immunofluorescence staining was used to detect the expression and distribution of β-catenin protein. Wnt signaling pathway activation was detected by TOPFlash/FOPFlash luciferase reporter assay. The targeting correlation of SOX6 and miR-19b-3p was corroborated by dual-luciferase reporter gene assay and RNA pull-down assay. MiR-19b-3p expression was once down-regulated, whilst SOX6 expression was up-regulated in HIE patients. MiR-19b-3p overexpression promoted cell proliferation, repressed cell apoptosis, oxidative stress response, and Wnt/β-catenin pathway activation in OGD/R-triggered HT22 cells. MiR-19b-3p negatively regulated SOX6 expression. SOX6 knockdown improved OGD/R-triggered HT22 cells injury via Wnt/β-catenin pathway activation. MiR-19b-3p overexpression suppressed OGD/R-triggered HT22 cell injury via inhibiting SOX6 expression via activating Wnt/β-catenin pathway.

MicroRNA-499-5p promotes vascular smooth muscle cell proliferation and migration via inhibiting SOX6

Atherosclerosis (AS) is the primary etiology of cardiovascular disease, which is considered the leading cause of death all over the world. MicroRNA miR-499-5p was involved in the functional regulation of myocardial and skeletal muscle, whereas its role in atherosclerosis, especially in vascular smooth muscle cells (VSMCs), remains unclear. Our study aims to investigate the effects of miR-499-5p in the proliferation and migration of VSMCs and potential mechanisms. We used mouse aortic vascular smooth muscle cells (MOVAS) and ApoE^-/- mice to establish the models of AS in vitro and in vivo, respectively. RT-PCR was performed to detect the expression level of miR-499-5p. Subsequently, Cell Counting Kit-8 (CCK-8) assays, Transwell assays, and wound-healing assays were used to evaluate cell proliferation and migration. Dual-luciferase reporter assay was performed to validate the interaction between miR-499-5p and SOX6. miR-499-5p significantly increased in aorta tissues of mice in AS tissues and vascular smooth muscle cells treated with ox-LDL. miR-499-5p overexpression could promote the proliferation and migration of MOVAS. Bioinformatics analysis predicted and further experiments verified that miR-499-5p could directly bind to the 3'-untranslated region (UTR) region of SOX6. Further, miR-499-5p induced an increased expression of smooth muscle proliferation and migration-related genes, PCNA, cyclin D1, and matrix metalloproteinase (MMP2), as well as the decreased expression of proliferation inhibiting factor p21, which was significantly reversed by SOX6 overexpression. miR-499-5p boosts the proliferation and migration of smooth muscle cells by binding and inhibiting SOX6 expression. The miR-499-5p/SOX6 axis may present a promising therapeutic implication for the prevention and treatment of cardiovascular diseases.

Effect of miR-499-5p/SOX6 axis on atrial fibrosis in rats with atrial fibrillation

Atrial fibrosis is involved in the progression of atrial fibrillation (AF). miR-499-5p is the most downregulated microRNA in arrhythmogenic cardiomyopathy hearts. Sry-related high-mobility-group box 6 (SOX6) is associated with apoptosis, inflammatory responses, and fibrosis. This study investigated the mechanism of miR-499-5p in ameliorating AF rats by regulating SOX6. AF rat models were established by injecting Ach-CaCl₂ mixture, and the rats were treated with Lv-miR-499-5p/oe-SOX6/si-SOX6 before modeling. AF duration was recorded using electrocardiogram. miR-499-5p and SOX6 expression levels in the myocardium were determined by reverse transcription-quantitative polymerase chain reaction. The binding of miR-499-5p and SOX6 was validated. The atrial fibrosis degree and cardiomyocyte apoptosis were assessed using the Masson and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining methods. Levels of SOX6, atrial fibrosis markers (collage I/α-SMA/TGFβ1), cell cycle-related proteins (p21/CDC25/Cyclin B1), and cell senescence markers (SA-β-gal/γ-H2AX) were measured using Western blotting and immunohistochemistry. miR-499-5p was downregulated and SOX6 was upregulated in AF rats. miR-499-5p overexpression shortened the AF duration, alleviated atrial fibrosis, and decreased collage I/α-SMA/TGFβ1. miR-499-5p targeted SOX6 to ameliorate atrial fibrosis. AF rats exhibited increased p21/CDC25/Cyclin B1/SA-β-gal/γ-H2AX levels and raised cardiomyocyte apoptosis. SOX6 silencing downregulated p21 and alleviated cardiomyocyte cycle arrest, cell senescence, and apoptosis in AF rats. Shortly, miR-499-5p suppresses atrial fibrosis and cardiomyocyte senescence by targeting SOX6 and downregulating p21, thus mitigating AF in rats.

Lactobacillus johnsonii YH1136 plays a protective role against endogenous pathogenic bacteria induced intestinal dysfunction by reconstructing gut microbiota in mice exposed at high altitude

Background

Intestinal microbiota plays an important role in maintaining the microecological balance of the gastrointestinal tract in various animals. Disturbances in the intestinal microbiota may lead to the proliferation of potentially pathogenic bacteria that become the dominant species, leading to intestinal immune disorders, intestinal inflammation, and other intestinal diseases. Numerous studies have been confirmed that high-altitude exposure affects the normal function of the intestine and the composition of the intestinal microbiota. However, it is still necessary to reveal the changes in intestinal microbiota in high-altitude exposure environments, and clarify the relationship between the proliferation of potentially pathogenic bacteria and intestinal injury in this environment. In addition, explored probiotics that may have preventive effects against intestinal diseases.

Methods and results

C57BL/6 mice were randomly divided into three groups, a high-altitude group (HA), control group (C), and high-altitude probiotic group (HAP). The HA and HAP groups were subjected to hypoxia modeling for 14 days in a low-pressure oxygen chamber with daily gavage of 0.2 mL of normal saline (HA) and Lactobacillus johnsonii YH1136 bacterial fluid (HAP), while the control group was fed normally. L. johnsonii YH1136 was isolated from feces of a healthy Tibetan girl in Baingoin county, the Nagqu region of the Tibet Autonomous Region, at an altitude of 5000 meters. Our observations revealed that gavage of YH1136 was effective in improving the damage to the intestinal barrier caused by high-altitude exposure to hypoxic environments and helped to reduce the likelihood of pathogenic bacteria infection through the intestinal barrier. It also positively regulates the intestinal microbiota to the extent of Lactobacillus being the dominant microbiome and reducing the number of pathogenic bacteria. By analyzing the expression profile of ileal microRNAs and correlation analysis with intestinal microbiota, we found that Staphylococcus and Corynebacterium1 cooperated with miR-196a-1-3p and miR-3060-3p, respectively, to play a regulatory role in the process of high-altitude hypoxia-induced intestinal injury.

Conclusion

These findings revealed the beneficial effect of L. johnsonii YH1136 in preventing potential endogenous pathogenic bacteria-induced intestinal dysfunction in high-altitude environments. The mechanism may be related to the regulation of intestinal injury from the perspective of the gut microbiota as well as miRNAs.

Transcriptome sequencing analysis of the role of miR-499-5p and SOX6 in chicken skeletal myofiber specification

MicroRNAs (miRNAs) might play critical roles in skeletal myofiber specification. In a previous study, we found that chicken miR-499-5p is specifically expressed in slow-twitch muscle and that its potential target gene is SOX6. In this study, we performed RNA sequencing to investigate the effects of SOX6 and miR-499-5p on the modulation and regulation of chicken muscle fiber type and its regulatory mechanism. The expression levels of miR-499-5p and SOX6 demonstrated opposing trends in different skeletal muscles and were associated with muscle fiber type composition. Differential expression analysis revealed that miR-499-5p overexpression led to significant changes in the expression of 297 genes in chicken primary myoblasts (CPMs). Myofiber type-related genes, including MYH7B and CSRP3, showed expression patterns similar to those in slow-twitch muscle. According to functional enrichment analysis, differentially expressed genes were mostly associated with muscle development and muscle fiber-related processes. SOX6 was identified as the target gene of miR-499-5p in CPM using target gene mining and luciferase reporter assays. SOX6 knockdown resulted in upregulation of the slow myosin genes and downregulation of fast myosin genes. Furthermore, protein-protein interaction network analysis revealed that MYH7B and RUNX2 may be the direct targets of SOX6. These results indicated that chicken miR-499-5p may promote slow-twitch muscle fiber formation by repressing SOX6 expression. Our study provides a dataset that can be used as a reference for animal meat quality and human muscle disease studies.

Circ_0123996 promotes the proliferation, inflammation, and fibrosis of mesangial cells by sponging miR-203a-3p to upregulate SOX6 in diabetic nephropathy

Circular RNA has been reported to participate in human diseases including diabetic nephropathy (DN). However, the role and mechanism of circ_0123996 in DN need to be further explored. Relative expression levels of circ_0123996, microRNA (miR)-203a-3p, SRY-box 6 (SOX6), and inflammatory cytokines were determined using quantitative real-time PCR. Western blot analysis was used to detect the protein expression of SOX6 and fibrosis-related markers. Cell proliferation was measured using the Cell Counting Kit 8 assay. The interaction between miR-203a-3p and circ_0123996 or SOX6 was verified using the dual-luciferase reporter assay. The circ_0123996 and SOX6 expression were increased and the miR-203a-3p expression was decreased in high glucose-induced mesangial cells. Silenced circ_0123996 could hinder the proliferation, inflammation, and fibrosis of mesangial cells. In terms of mechanism, circ_0123996 could sponge miR-203a-3p to positively regulate SOX6 expression. Function experiments revealed that miR-203a-3p inhibitor could abolish the regulation of circ_0123996 silencing on mesangial cell proliferation, inflammation, and fibrosis. In addition, the knockdown of SOX6 could inhibit mesangial cell proliferation, inflammation, and fibrosis. Also, SOX6 overexpression could reverse the regulation of circ_0123996 silencing on mesangial cell progression. In summary, our data revealed that circ_0123996 promoted the proliferation, inflammation, and fibrosis of mesangial cells via modulating the miR-203a-3p/SOX6 axis, suggesting that circ_0123996 might be a target for alleviating DN progression.

Diagnostic value of cardiac miR-126-5p, miR-134-5p, and miR-499a-5p in coronary artery disease-induced sudden cardiac death

Background

The identification of coronary artery disease-induced sudden cardiac death (CAD-SCD) has always been a medical challenge. MicroRNAs (miRNAs) played vital roles in pathogenesis processes and served as potential biomarkers for cardiovascular and many other diseases. The aim of this study was to investigate the diagnostic value of the specific miRNAs for CAD-SCD.

Methods

A total of 30 autopsy-verified CAD-SCD victims were selected, including 18 individuals who experienced more than once asymptomatic myocardial ischemia (CAD-activated SCD) and 12 victims without prominent pathological features of insufficient blood supply (CAD-silent SCD). Meanwhile, 30 traumatic victims were enrolled as controls. Systematic postmortem examinations were performed in all study population. The expressions of cardiac miR-126-5p, miR-134-5p, and miR-499a-5p were analyzed by real-time quantitative polymerase chain reaction (RT-qPCR).

Results

RT-qPCR showed significant downregulations of miR-126-5p and miR-499a-5p in CAD-SCD victims, with no obvious difference in miR-134-5p. Receiver-operating characteristic analysis revealed the diagnostic performance of miR-126-5p (areas under the curve [AUC] = 0.76) and validated miR-499a-5p (AUC = 0.82) as a sensitive marker. Additionally, the decreased expression of the two specific cardio-miRNAs was detected for discriminating CAD-silent SCD and CAD-activated SCD. Compared with the limited diagnostic value of single miR-126-5p and miR-499a-5p, their combination could achieve better discriminative capacity (AUC = 0.82, sensitivity = 91.7%, specificity = 77.8%).

Conclusion

Cardiac miR-126-5p and miR-499a-5p presented good diagnostic abilities for CAD-SCD, and their combination could help evaluate CAD condition. These targeted miRNAs as novel biomarkers are expected to be useful to discriminate the detailed causes in real SCD cases.

Associations of serum expressions of miR-499 and sex determining region Y-box 6 with prognosis of acute myocardial infarction patients

Background: To explore the associations of serum expressions of miR-499 and sex determining region Y-box 6 (SOX6) with major adverse cardiovascular and cerebrovascular events (MACCE) and prognosis of acute myocardial infarction (AMI) patients undergoing percutaneous coronary intervention (PCI).

Methods: The clinical data of 132 patients diagnosed from February 2016 to October 2019 were collected. Serum miR-499 and SOX6 expressions were detected by RT-qPCR. Optimal cut-off values were determined using receiver operating characteristic curves, based on which patients were divided into low and high miR-499 expression groups, and high and low SOX6 expression groups. Survival curves were plotted using Kaplan-Meier method, and the independent risk factors for MACCE were explored by multivariate logistic regression analysis. A nomogram model was established based on the factors and validated using internal data.

Results: AMI group had higher miR-499 expression and lower SOX6 expression than those of control group (P<0.05). After PCI, miR-499 expression decreased and SOX6 expression increased (P<0.05). Low miR-499 expression group had higher 3-year survival and MACCE-free rates than those of high miR-499 expression group (P<0.05). Low SOX6 expression group had lower 3-year survival and MACCE-free rates than those of high SOX6 expression group (P<0.05). AMI history, LVEF, CK-MB, miR-499 and SOX6 expressions were independent risk factors for MACCE (P<0.05). The nomogram model had high accuracy for predicting overall survival, with a concordance index of 0.742 (95%CI=0.684-0.845).

Conclusions: AMI patients have increased serum expression of miR-499 and decreased expression of SOX6. High miR-499 expression is an independent risk factor for poor prognosis. The established nomogram model can be used to predict the risk of MACCE after PCI.

Sox6, A Potential Target for MicroRNAs in Cardiometabolic Disease

PURPOSE OF REVIEW

The study aims to review recent advances in knowledge on the interplay between miRNAs and the sex-determining Region Y (SRY)-related high-mobility-group box 6 (Sox6) in physiology and pathophysiology, highlighting an important role in autoimmune and cardiometabolic conditions.

RECENT FINDINGS

The transcription factor Sox6 is an important member of the SoxD family and plays an indispensable role in adult tissue homeostasis, regeneration, and physiology. Abnormal expression of the Sox6 gene has been implicated in several disease conditions including diabetes, cardiomyopathy, autoimmune diseases, and hypertension. Expression of Sox6 is regulated by miRNAs, which are RNAs of about 22 nucleotides, and have also been implicated in several pathophysiological conditions where Sox6 plays a role. Regulation of Sox6 by miRNAs is important in diverse physiological tissues and organs. Dysregulation of the interplay between miRNAs and Sox6 is an important determinant of various disease conditions and may be actionable for therapeutic purposes.

Therapeutic Targets for Regulating Oxidative Damage Induced by Ischemia-Reperfusion Injury: A Study from a Pharmacological Perspective

Ischemia-reperfusion (I-R) injury is damage caused by restoring blood flow into ischemic tissues or organs. This complex and characteristic lesion accelerates cell death induced by signaling pathways such as apoptosis, necrosis, and even ferroptosis. In addition to the direct association between I-R and the release of reactive oxygen species and reactive nitrogen species, it is involved in developing mitochondrial oxidative damage. Thus, its mechanism plays a critical role via reactive species scavenging, calcium overload modulation, electron transport chain blocking, mitochondrial permeability transition pore activation, or noncoding RNA transcription. Other receptors and molecules reduce tissue and organ damage caused by this pathology and other related diseases. These molecular targets have been gradually discovered and have essential roles in I-R resolution. Therefore, the current study is aimed at highlighting the importance of these discoveries. In this review, we inquire about the oxidative damage receptors that are relevant to reducing the damage induced by oxidative stress associated with I-R. Several complications on surgical techniques and pathology interventions do not mitigate the damage caused by I-R. Nevertheless, these therapies developed using alternative targets could work as coadjuvants in tissue transplants or I-R-related pathologies

Epigenome-Wide Association Study Reveals Differential Methylation Sites and Association of Gene Expression Regulation with Ischemic Moyamoya Disease in Adults

Background

The association of DNA methylation with the pathogenesis of adult ischemic moyamoya disease (MMD) is unknown. Here, we investigated the genome-wide DNA methylation profiles in patients with MMD and identified the genes related to the pathogenesis of MMD.

Methods

Whole blood samples were collected from 20 individuals, including 10 patients with ischemic moyamoya disease without any underlying disease and 10 healthy individuals. Genome-wide DNA methylation analysis was performed using Illumina 850K microarrays. Transcriptional correlation was verified using quantitative reverse transcription-polymerase chain reaction. In vitro experiments were used to analyze the association of functional defects with candidate epigenetic markers.

Results

The genome-wide methylation level in the whole blood of adults with ischemic MMD was higher than that in the healthy individuals. In total, 759 methylation probes differed significantly between the case and control. The hypermethylated regions were mostly concentrated in the gene spacer regions. Among genes with the highest degree of the differential expression, KCNMA1 and GALNT2 were upregulated, whereas SOX6 and RBM33 were downregulated.

Conclusions

This is the first study showing that the low expression of genes associated with epigenetic regulation, such as SOX6 and RBM33, may be related to vascular occlusion in MMD, whereas the overexpression of KCNMA1 and GALNT2 may be related to the vascular hyperplasia. The results suggest that DNA methylation was involved in the pathogenesis of MMD, and new pathogenic genes were proposed as biological markers.

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.

Differential expression of miRNA in histological subtype of Wilms tumor

INTRODUCTION

Wilms tumor is the most common renal malignancy in children and difficult to differentiate from other paediatric abdominal tumors radiologically, necessitating an invasive procedure for diagnosis. Previous studies have shown the potential role of miRNA as biomarkers for diagnosis, histological subtyping and prognosis. In this study, we are exploring the role of miRNA in the histological subtyping of Wilms tumor in the Indian population.

MATERIALS AND METHODS

A total of 15 cases of Wilms tumor were evaluated for global miRNA expression analysis by microarray. Total RNA was extracted from fresh frozen tumor and miRNA expression analysis was performed using Agilent platform. Unsupervised clustering was done to analyse the data.

RESULTS

Using unpaired student T test, top 10 significantly differentially expressed miRNA were selected which could differentiate among different histological subtypes by unsupervised hierarchical clustering and principal component analysis. The presence of necrosis, heterologous differentiation led to change in miRNA expression profile and led to a distinct cluster formation.

CONCLUSIONS

A panel of 5 miRNAs (miR1, 133b, 299-3p, 499a-5p, 491-3p) could differentiate among different histological subtypes of Wilms tumor, thus avoiding an invasive procedure in children, however, further confirmation using real time PCR analysis will be needed.

Circ_0001206 regulates miR-665/CRKL axis to alleviate hypoxia/reoxygenation-induced cardiomyocyte injury in myocardial infarction

Aims

Myocardial infarction (MI) is a type of cardiovascular disease caused by myocardial necrosis. Growing evidences have suggested that circular RNAs (circRNAs) play crucial roles in cardiac hypoxia/reoxygenation (H/R)‐induced injury of MI.

Methods and results

Hypoxia/reoxygenation model of H9C2 cells was established and circ_0001206 expression was detected via quantitative real‐time polymerase chain reaction. Ribonuclease R (RNase R) and Actinomycin D (Act D) assays verified the stability. Cell counting kit‐8 (CCK‐8), western blot, TUNEL, and flow cytometry assays evaluated cell viability and cell apoptosis. RNA pull‐down, RNA binding protein immunoprecipitation (RIP), and luciferase reporter assays explored the mechanisms underlying MI. All experimental data were presented with mean ± standard deviation (SD) and P < 0.05 indicated statistical significance. Circ_0001206 was low‐expressed in H9C2 cells under H/R treatment. Circ_0001206 was formed by cyclization of CRK like proto‐oncogene, adaptor protein (CRKL). Circ_0001206 overexpression promoted cell viability and inhibited cardiomyocyte apoptosis. It was confirmed that circ_0001206 regulated CRKL expression via acting as a competing endogenous RNA (ceRNA) of microRNA‐665 (miR‐665). CRKL played a protective role in MI.

Conclusions

Circ_0001206 regulates miR‐665/CRKL axis to alleviate H/R‐induced cardiomyocyte injury in MI. Our findings suggest that circ_0001206 might be a potential target for MI treatment.

Ferulic Acid Alleviates Oxidative Stress-Induced Cardiomyocyte Injury by the Regulation of miR-499-5p/p21 Signal Cascade

Objective

To investigate the protective effects and regulatory mechanisms of ferulic acid on oxidative stress-induced cardiomyocyte injury.

Methods

We established a cardiomyocyte oxidative stress cell model by H₂O₂ treatment and a mouse heart injury model by isoprenaline infusion of male C57BL/6 mice. Ferulic acid was applied to treat oxidative stress-induced cardiomyocyte injury. DHE staining was used to detect ROS production. DNA fragmentation, TUNEL assay, and cleaved caspase-3 were used to analyze cell apoptosis. Real-time PCR and Western blotting were used to analyze miRNA and protein levels to investigate the regulatory mechanisms of ferulic acid on oxidative stress-induced cardiomyocyte injury.

Results

Ferulic acid pretreatment significantly inhibited H₂O₂- and isoprenaline-induced oxidative stress and cell apoptosis by promoting miR-499-5p expression and inhibiting p21 expression. MiR-499-5p inhibition reversed the protective effects of ferulic acid. Further study found that ferulic acid could also attenuate isoprenaline-induced mouse heart fibrosis and cell apoptosis by reducing oxidative stress, inflammation, and apoptosis in vivo.

Conclusions

We proved that ferulic acid protects cardiomyocytes from oxidative stress-induced injury by regulating the miR-499-5p/p21signaling pathway, which provides insight into the clinical application of ferulic acid in the treatment of cardiovascular diseases.

Dysregulation of miR-342-3p in plasma exosomes derived from convalescent AMI patients and its consequences on cardiac repair

Plasma exosomes derived from healthy people have been shown to be beneficial in terms of protecting against ischemia-reperfusion injury or acute myocardial infarction (AMI). However, a pathological condition may severely affect the constitution and biological activity of exosomes. In our study, we isolated plasma exosomes from healthy volunteers and convalescent AMI patients (3-7 d after onset). Compared to exosomes from healthy controls (Nor-Exo), exosomes from convalescent AMI patients (AMI-Exo) exhibited an impaired ability to repair damaged cardiomyocytes both in vitro and in vivo. miRNA sequencing and PCR analysis indicated that miR-342-3p was significantly downregulated in AMI-Exo. Moreover, miR-342-3p alleviated H2O2-induced injury and reduced apoptosis and autophagy in H9c2 cardiomyocytes, while in vivo restoration of miR-342-3p expression enhanced the reparative function of AMI-Exo. Further mechanistic studies revealed that the SOX6 and TFEB genes were two direct and functional targets of miR-342-3p. Taken together, during the early convalescent phase after AMI, dysregulated miR-342-3p in plasma exosomes might be responsible for their impaired cardioprotective potential. miR-342-3p contributed to exosome-mediated heart repair by inhibiting cardiomyocyte apoptosis and autophagy through targeting SOX6 and TFEB, respectively. Our work provided novel insights on the role of plasma exosomes in the natural process of cardiac repair after AMI and suggestions for therapy development.

miR-3113-5p, miR-223-3p, miR-133a-3p, and miR-499a-5p are sensitive biomarkers to diagnose sudden cardiac death

Background

Sudden cardiac death (SCD) remains a great health threat and diagnostic challenge, especially those cases without positive autopsy findings. Molecular biomarkers have been urgently needed for the diagnosis of SCD displaying negative autopsy results. Due to their nature of stability, microRNAs (miRNAs) have emerged as promising diagnostic biomarkers for cardiovascular diseases.

Methods

This study investigated whether specific cardio-miRNAs (miR-3113-5p, miR-223-3p, miR-499a-5p, and miR-133a-3p) could serve as potential biomarkers for the diagnosis of SCD. Thirty-four SCD cases were selected, 18 categorized as SCD with negative autopsy (SCD-negative autopsy) findings and 16 as SCD with positive autopsy (SCD-positive autopsy) findings such as coronary atherosclerosis and gross myocardial scar. Carbon monoxide (CO) intoxication (n = 14) and fatal injury death (n = 14) that displayed no pathological changes of myocardium were selected as control group, respectively. Histological analyses were performed to reveal the pathological changes and real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the expression of those miRNAs.

Results

It showed that heart samples from the SCD-negative autopsy group displayed no remarkable difference with regard to the expression of cleaved-caspase3, CD31, and CD68 and the extent of fibrotic tissue accumulation when compared with control samples. The four cardio-miRNAs were significantly up-regulated in the SCD samples as compared with control. When discriminating SCD from controls, receiver operating characteristic (ROC) curve analysis revealed that the areas under the curve (AUC) of these 4 miRNAs were from 0.7839 to 0.9043 with sensitivity of 64.71–97.06% and specificity of 70–100%. Moreover, when discriminating the specific causes of SCD, the four miRNA expressions increased in the heart from the SCD-negative autopsy group as relative to that from the SCD-positive autopsy group, and a combination of two miRNAs presented higher diagnostic value (AUC = 0.7407–0.8667).

Conclusion

miR-3113-5p, miR-223-3p, miR-499a-5p, and miR-133a-3p may serve as independent diagnostic biomarkers for SCD, and a combination of two of these miRNAs could further discriminate detailed causes of SCD.

The potential of miR-499 plasmatic level as a biomarker of obstructive sleep apnea syndrome

Background: Obstructive sleep apnea syndrome (OSAS) is one of the most common sleep-related breathing disorders. The aim of this study was to improve diagnostics in OSAS using blood circulating biomarkers. We consider the potential of cardiac-specific miRNAs in the diagnosis and risk assessment of cardiovascular complications. Materials & methods: Plasmatic levels of miR-1-3p, miR-133a-3p and miR-499a-5p were measured by reverse transcription-PCR and compared with the clinical status of OSAS patients and controls. Results: The level of miR-499 was higher (p = 0.0343) in OSAS patients (mean expression: 0.00561) compared with the controls (mean expression: 0.00003), using the multivariate logistic regression. Conclusion: The role of miR-499 in gene expression regulation during hypoxia and our findings indicate that miR-499 could be a new diagnostic biomarker for OSAS.

Curcumin promotes venous thrombi resolve process in a mouse deep venous thrombosis model via regulating miR-499

BACKGROUND/AIMS

The morbidity of deep venous thrombosis (DVT) is increasing rapidly and the current therapeutic strategies for DVT are unsatisfactory. Accumulating evidence suggest that venous thrombi resolve (VTR) may provide new insights into DVT therapeutic strategies. The aim of this study was to investigate the role of curcumin in VTR process and try to reveal the potential mechanism.

METHODS

Immunofluorescence and HE staining were performed to investigate the therapeutic angiogenesis effect of curcumin in VTR process. Microarray analysis and RT-PCR were performed to examine the expression level of miR-499 in thrombosis after curcumin administration. Cell proliferation, migration and angiogenesis capacity were tested by CCK8 assay, Transwell assay and Tube formation assay, respectively. Dual-luciferase reporter assay (DLR) was used to confirm the connection between miR-499 and paired phosphate and tension homology deleted on chromosome ten (PTEN).

RESULTS

We found that curcumin could effectively promote VTR process by activating angiogenesis in thrombus in vivo. The expression of miR-499 exhibited notably downregulated after curcumin administration. The proangiogenic effect of curcumin in HUVECs could be blocked by miR-499 overexpression. In addition, we confirmed that miR-499 directly target to the 3'UTR region of PTEN.

CONCLUSION

Curcumin promotes VTR process in DVT through activating therapeutic angiogenesis. Mechanically, curcumin promotes therapeutic angiogenesis by regulating miR-499 mediated PTEN/VEGF/Ang-1 signaling pathway.

Role of microRNA-129 in cancer and non-cancerous diseases (Review)

An increasing number of studies indicate that microRNAs (miRNAs/miRs) are involved in diverse biological signaling pathways and play important roles in the progression of various diseases, including both oncological and non-oncological diseases. These small non-coding RNAs can block translation, resulting in a low expression level of target genes. miR-129 is an miRNA that has been the focus of considerable research in recent years. A growing body of evidence shows that the miR-129 family not only functions in cancer, including osteosarcoma, nasopharyngeal carcinoma, and ovarian, prostate, lung, breast and colon cancer, but also in non-cancerous diseases, including heart failure (HF), epilepsy, Alzheimer's disease (AD), obesity, diabetes and intervertebral disc degeneration (IVDD). It is therefore necessary to summarize current research progress on the role of miR-129 in different diseases. The present review includes an updated summary of the mechanisms of the miR-129 family in oncological and non-oncological diseases. To the best of our knowledge, this is the first review focusing on the role of miR-129 in non-cancerous diseases such as obesity, HF, epilepsy, diabetes, IVDD and AD.

M2 macrophage-derived exosomes carry miR-1271-5p to alleviate cardiac injury in acute myocardial infarction through down-regulating SOX6

BACKGROUND

Emerging evidence has indicated that exosomes serve as key regulators in acute myocardial infarction (AMI). This study was determined to investigate the effect of M2 macrophage-derived exosomes (M2-Exos) in AMI and the further mechanism.

METHODS

M2 macrophages were induced and M2-exos were isolated and verified. The AMI mouse model was prepared by ligation of the left anterior descending coronary artery (LAD) and then intravenously injected with the isolated M2-exos. The mouse cardiac function was assessed by echocardiography. Hematoxylin and eosin (HE) staining and TUNEL assay were conducted to examine myocardial lesion and apoptosis in cardiac tissues. The expressions of associated molecules were detected by quantitative real time-PCR (qRT-PCR) and western blot. MTT assay, Flow cytometry and Dual-luciferase reporter assay were carried out to detect cell viability, apoptosis and the interaction of miRNA and the target.

RESULT

M2-Exos could promote cardiac repair in AMI mice. M2-Exos suppressed apoptosis and enhanced viability of hypoxia-induced cardiomyocytes through delivery of miR-1271-5p. SOX6 is a direct target of miR-1271-5p. miR-1271-5p decreased cardiomyocyte apoptosis induced by hypoxia and alleviated cardiac injury in AMI via down-regulating SOX6 expression.

CONCLUSION

We identified that M2-Exos could carry miR-1271-5p to reduce apoptosis of cardiomyocytes and promote cardiac repair via down-regulating SOX6.

Restoring microRNA-499-5p Protects Sepsis-Induced Lung Injury Mice Via Targeting Sox6

BACKGROUND

MicroRNAs (miRs) are known to participate in sepsis; hence, we aim to discuss the protective effect of miR-499-5p targeting sex-determining region Y-related high-mobility-group box 6 (Sox6) on sepsis-induced lung injury in mice.

METHODS

The sepsis-induced lung injury model was established by cecal ligation and puncture. The wet/dry weight (W/D) ratio, miR-499-5p, Sox6, Caspase-3 and Caspase-9 expression in lung tissues of mice were tested. Lung injury score, collagen fibers and the degree of pulmonary fibrosis in lung tissues were determined. Further, the cell apoptosis in lung tissues was measured. The inflammatory factors contents and oxidative stress indices in bronchoalveolar lavage fluid (BALF) and lung tissues were detected via loss- and gain-of-function assays. The targeting relation between miR-499-5p and Sox6 was verified.

RESULTS

W/D ratio and Sox6 were increased while miR-499-5p was decreased in lung tissues of sepsis-induced lung injury mice. Restored miR-499-5p or depleted Sox6 alleviated lung tissues pathology, reduced lung injury score, collagen fibers, the degree of pulmonary fibrosis, TUNEL positive cells, Caspase-3 and Caspase-9 protein expression and inflammatory factors contents in BALF and lung tissues as well as oxidative stress response in lung tissues of sepsis-induced lung injury mice. miR-499-5p targeted Sox6.

CONCLUSION

High expression of miR-499-5p can attenuate cell apoptosis in lung tissues and inhibit inflammation of sepsis-induced lung injury mice via depleting Sox6, and it is a potential candidate marker and therapeutic target for sepsis-induced lung injury.

Hyperoside ameliorates diabetic nephropathy induced by STZ via targeting the miR-499-5p/APC axis

Diabetic nephropathy is a serious complication of diabetes. Hyperoside has been widely reported to ameliorate diabetes-associated disease. The current study is designed to explore the mechanism of hyperoside in diabetic nephropathy. In the present study, high glucose was used to treat podocytes. Diabetic nephropathy mice models were established by high-fat feeding followed by multiple low dose injections of streptozocin. Western blot analysis was conducted for detection of extracellular matrix accumulation, inflammatory response and cell apoptosis. We found out that hyperoside improved high glucose-induced cell injury. Additionally, hyperoside prevented mice with diabetic nephropathy from diabetic symptoms and renal dysfunction. Mechanistically, hyperoside inhibited the mRNA and protein expression of APC. MiR-499-5p was found to be an upstream negative mediator of APC, and hyperoside induced the upregulation of miR-499-5p. MiR-499-5p bound with the 3' untranslated region of APC to inhibit its expression. Finally, rescue assays revealed that the suppressive effects of miR-499-5p overexpression on renal dysfunction were rescued by upregulation of APC in mice with diabetic nephropathy. In conclusion, these findings indicated that hyperoside ameliorates diabetic nephropathy via targeting the miR-499-5p/APC axis, suggesting that hyperoside may offer a potential tactic for diabetic nephropathy treatment.

MicroRNA-499 serves as a sensitizer for lung cancer cells to radiotherapy by inhibition of CK2α-mediated phosphorylation of p65

The present study aimed to define the tumor-suppressive role of microRNA-499 (miR-499) in lung cancer cells and its underlying mechanism. First, qRT-PCR analysis revealed poor expression of miR-499 in clinical samples and cell lines of lung cancer. Next, we performed loss- and gain-of-function experiments for the expression of miR-499 in lung cancer cells exposed to irradiation (IR) to determine the effect of miR-499 expression on cell viability and apoptosis as well as tumor growth. Results showed that overexpression of miR-499 inhibited cell viability, enhanced the radiosensitivity of lung cancer cells, and promoted cell apoptosis under IR. Furthermore, CK2α was verified to be a target of miR-499, and miR-499 was identified to repress p65 phosphorylation by downregulating CK2α expression, which ultimately diminished the survival rate of lung cancer cells under IR. Collectively, the key findings of the study illustrate the tumor-inhibiting function of miR-499 and confirmed that miR-499-mediated CK2α inhibition and altered p65 phosphorylation enhances the sensitivity of lung cancer cells to IR.

Cell type-specific microRNA therapies for myocardial infarction

Current interventions fail to recover injured myocardium after infarction and prompt the need for development of cardioprotective strategies. Of increasing interest is the therapeutic use of microRNAs to control gene expression through specific targeting of mRNAs. In this Review, we discuss current microRNA-based therapeutic strategies, describing the outcomes and limitations of key microRNAs with a focus on target cell types and molecular pathways. Last, we offer a perspective on the outlook of microRNA therapies for myocardial infarction, highlighting the outstanding challenges and emerging strategies.

MicroRNA-499-5p targets SIRT1 to aggravate lipopolysaccharide-induced acute lung injury

Acute lung injury (ALI) is a life-threatening disease without effective and specific therapeutic strategies except the life-supporting treatments. Inflammation and oxidative stress are essential for the progression of ALI. MicroRNA-499-5p (miR-499-5p) has multiple pathophysiological actions; however, its function and mechanisms in ALI remain elusive. Mice were intravenously injected with miR-499-5p agomir, antagomir or the negative controls for 3 consecutive days and then received a single intratracheal injection of lipopolysaccharide (LPS, 5 mg/kg) to generate ALI model. Twenty four hours prior to LPS injection, EX-527 (1 mg/kg) was applied to inhibit SIRT1 activity. We identified a significant upregulation of miR-499-5p in LPS-treated lung tissues. miR-499-5p antagomir prevented, while miR-499-5p agomir promoted inflammation, oxidative stress and ALI in LPS-treated mice. Further studies indicated that miR-499-5p directly bound to the 3'-untranslated region of Sirtuin 1 (Sirt1) and decreased its protein level. SIRT1 inhibition blocked miR-499-5p antagomir-mediated pulmonary protection against LPS injury. miR-499-5p targets SIRT1 to aggravate LPS-induced ALI and it is a promising therapeutic target for the treatment of ALI.

Emerging roles of Sox6 in the renal and cardiovascular system

The function of Sex-determining Region Y (SRY)-related high-mobility-group box (Sox) family of transcription factors in cell fate decisions during embryonic development are well-established. Accumulating evidence indicates that the Sox family of transcription factors are fundamental in adult tissue homeostasis, regeneration, and physiology. The SoxD subfamily of genes are expressed in various cell types of different organs during embryogenesis and adulthood and have been involved in cell-fate determination, cellular proliferation and survival, differentiation, and terminal maturation in a number of cell lineages. The dysregulation in the function of SoxD proteins (i.e. Sox5, Sox6, Sox13, and Sox23) have been implicated in different disease conditions such as chondrodysplasia, cancer, diabetes, hypertension, autoimmune diseases, osteoarthritis among others. In this minireview, we present recent developments related to the transcription factor Sox6, which is involved in a number of diseases such as diabetic nephropathy, adipogenesis, cardiomyopathy, inflammatory bowel disease, and cancer. Sox6 has been implicated in the regulation of renin expression and JG cell recruitment in mice during sodium depletion and dehydration. We provide a current perspective of Sox6 research developments in last five years, and the implications of Sox6 functions in cardiovascular physiology and disease conditions.

MicroRNAs: roles in cardiovascular development and disease

Cardiovascular diseases (CVDs) comprise a group of disorders ranging from peripheral artery, coronary artery, cardiac valve, cardiac muscle, and congenital heart diseases to arrhythmias and ultimately, heart failure. For all the advances in therapeutics, CVDs are still the leading cause of mortality the world over, hence the significance of a thorough understanding of CVDs at the molecular level. Disparities in the expressions of genes and microRNAs (miRNAs) play a crucial role in the determination of the fate of cellular pathways, which ultimately affect an organism's physiology. Indeed, miRNAs serve as the regulators of gene expressions in that they perform key functions both in several important cellular pathways and in the regulation of the onset of various diseases such as CVDs. Many miRNAs are expressed in embryonic, postnatal, and adult hearts; their aberrant expression or genetic deletion is associated with abnormal cardiac cell differentiation, disruption in heart development, and cardiac dysfunction. A substantial body of evidence implicates miRNAs in CVD development and suggests them as diagnostic biomarkers and intriguing therapeutic tools. The present review provides an overview of the history, biogenesis, and processing of miRNAs, as well as their function in the development, remodeling, and diseases of the heart.

Effects of Oxidative Stress on Protein Translation: Implications for Cardiovascular Diseases

Cardiovascular diseases (CVDs) are a group of disorders that affect the heart and blood vessels. Due to their multifactorial nature and wide variation, CVDs are the leading cause of death worldwide. Understanding the molecular alterations leading to the development of heart and vessel pathologies is crucial for successfully treating and preventing CVDs. One of the causative factors of CVD etiology and progression is acute oxidative stress, a toxic condition characterized by elevated intracellular levels of reactive oxygen species (ROS). Left unabated, ROS can damage virtually any cellular component and affect essential biological processes, including protein synthesis. Defective or insufficient protein translation results in production of faulty protein products and disturbances of protein homeostasis, thus promoting pathologies. The relationships between translational dysregulation, ROS, and cardiovascular disorders will be examined in this review.

Downregulation of miR-483-5p decreases hypoxia-induced injury in human cardiomyocytes by targeting MAPK3

Background

MiR-483-5p was recently identified as a risk factor in the early stages of acute myocardial infarction (AMI) patients. Here, we further investigated how miR-483-5p affects cardiomyocyte apoptosis and oxidative stress under hypoxic conditions.

Methods

Plasma samples were collected from AMI patients and healthy volunteers. The expression of miR-483-5p was determined using quantitative real-time PCR. An in vitro hypoxic model was constructed to mimic AMI in AC16 cells. Cell viability, apoptosis and oxidative stress biomarker levels (MDA, SOD and CAT) were respectively determined using CCK-8, flow cytometry and commercial assay kits.

Results

The expression levels of miR-483-5p were significantly higher in AMI patients than in control subjects. Circulating levels of miR-483-5p positively correlated with creatine kinase MB isoform (CK-MB) and cardiac troponin I (cTnI) levels. The in vitro experiments showed that the expression levels of miR-483-5p were also upregulated in hypoxia-induced AC16 cell injury. MiR-483-5p overexpression significantly increased hypoxia-induced cardiomyocyte apoptosis and oxidative stress, while knockdown attenuated these effects. Mechanistically, miR-483-5p directly targets MAPK3 in AC16 cells. Furthermore, the protective effects of miR-483-5p knockdown against hypoxia-induced cardiomyocyte injury are partially dependent on MAPK3.

Conclusions

MiR-483-5p, which targets MAPK3, might be a potential therapeutic target for the diagnosis and prevention of hypoxia-induced myocardial injury.

Inhibition of long non-coding RNA TUG1 protects against diabetic cardiomyopathy induced diastolic dysfunction by regulating miR-499-5p

Reportedly, several long non-coding RNAs (lncRNAs) have been involved in the regulation of cardiac hypertrophy induced by diabetic cardiomyopathy (DCM), causing cardiac dysfunction and subsequent failure. Although lncRNA taurine upregulated gene 1 (TUG1) is associated with myocardial injury, the expression profile and potential role of TUG1 in DCM-related cardiac hypertrophy remain unknown. This study elucidated the functions of TUG1 in DCM and its underlying mechanisms. Our results demonstrated that the expression of TUG1 was upregulated in db/db mice cardiomyocytes. Inhibition of TUG1 by lentivirus si-TUG1 indicated no effect on systolic function; however, it effectively improved DCM-induced diastolic dysfunction in db/db mice. TUG1 silencing demonstrated no influence on the metabolic characteristics of DCM, including blood glucose and lipid levels. Notably, TUG1 knockdown significantly decreased cardiac hypertrophy and reduced the fibrotic area, in vivo. To further investigate the underlying mechanism, miR-499-5p was predicted as the targeted TUG1 microRNA. The RT-qPCR and luciferase activity results confirmed that TUG1 negatively regulated miR-499-5p in cardiomyocytes. Furthermore, the overexpression of miR-499-5p abated the inhibitory effects of TUG1 silencing on high glucose-mediated cardiac hypertrophy, in vitro. Collectively, our study suggested that TUG1 knockdown attenuated DCM-induced cardiac hypertrophy and diastolic dysfunction by upregulating miR-499-5p. lncRNA TUG1 may be a novel potential target for DCM therapy.

Novel Mechanisms of Exercise-Induced Cardioprotective Factors in Myocardial Infarction

Exercise training has been reported to ameliorate heart dysfunction in both humans and animals after myocardial infarction (MI). Exercise-induced cardioprotective factors have been implicated in mediating cardiac repair under pathological conditions. These protective factors secreted by or enriched in the heart could exert cardioprotective functions in an autocrine or paracrine manner. Extracellular vesicles, especially exosomes, contain key molecules and play an essential role in cell-to-cell communication via delivery of various factors, which may be a novel target to study the mechanism of exercise-induced benefits, besides traditional signaling pathways. This review is designed to demonstrate the function and underlying protective mechanism of exercise-induced cardioprotective factors in MI, with an aim to offer more potential therapeutic targets for MI.

Human umbilical cord mesenchymal stem cells-derived exosomes transfers microRNA-19a to protect cardiomyocytes from acute myocardial infarction by targeting SOX6

Exosomes secreted by human umbilical cord mesenchymal stem cells (hucMSCs) protect cardiomyocytes from anoxia-reoxygenation injury. But the mechanism of hucMSC-exo-microRNA (miR)-19a in acute myocardial infarction (AMI) remains unclear. For this study, cardiac function related indicators, inflammatory factors and markers of myocardial injury, cardiomyocyte injury, infarct size, and apoptosis were detected in vivo experiments. The gain-and loss-of function was performed to evaluate the effects of hucMSC-exo with down/upregulated miR-19a on AMI rats and hypoxic H9C2 cells. Western blot analysis was used to detect levels of AKT/JNK3/caspase-3 axis-related proteins. Consequently, hucMSC-exo alleviated AMI and inhibited cardiomyocyte apoptosis. miR-19a was downregulated in AMI tissues and cells, and increased after hucMSC-exo treatment. miR-19a knockdown in hucMSC-exo impaired the protective role of hucMSC-exo alone in the AMI damage. SOX6 is a target gene of miR-19a and its inhibition lightened hypoxic damage of H9C2 cells. SOX6 knockdown together with miR-19a inhibition in hucMSC-exo activated AKT and inhibited JNK3/caspase-3 axis. Taken together, hucMSC-exo protected cardiomyocytes from AMI injury by transferring miR-19a, targeting SOX6, activating AKT, and inhibiting JNK3/caspase-3 activation. This study may provide new understanding for AMI treatment.

MicroRNA-129-5p alleviates nerve injury and inflammatory response of Alzheimer's disease via downregulating SOX6

There is growing evidence of the position of microRNAs (miRs) in Alzheimer's disease (AD), thus our objective was to discuss the impact of miR-129-5p regulating nerve injury and inflammatory response in AD rats by modulating SOX6 expression. The AD rat model was established by injecting Aβ_25-35 into the brain. The pathological changes, ultrastructure, number of neurons, cell degeneration and apoptosis of hippocampal tissue were observed in vivo. MiR-129-5p, SOX6, IL-1β, TNF-α, Bcl-2 and Bax expression in serum and hippocampal tissues were detected by ELISA, RT-qPCR or western blot analysis. The successfully modeled hippocampal neuronal cells of AD were transfected with miR-129-5p mimic, SOX6-siRNA or their controls to figure out their roles in proliferation, apoptosis and inflammatory reaction in vitro. Low expression of SOX6 and high expression of miR-129-5p in vivo of rats would shorten the escape latent period and increase the times of crossing platforms, alleviate the pathological injury, inhibit neuronal apoptosis and reduce the inflammatory reaction. Up-regulation of miR-129-5p and down-regulation of SOX6 promoted proliferation, suppressed apoptosis and degraded the inflammatory reaction of neuronal cells in vitro. Up-regulation of SOX6 reversed the expression of miR-129-5p to reduce the damage and inflammatory response of the cell model of AD. Our study presents that up-regulation of miR-129-5p or down-regulation of SOX6 can reduce nerve injury and inflammatory response in rats with AD. Thus, miR-129-5p may be a potential candidate for the treatment of AD.