Circulating miR-499 as a potential biomarker for acute myocardial infarction

Design and analysis of self-priming extension DNA hairpin probe for miRNA detection based on a unified dynamic programming framework

MicroRNAs (miRNAs) are potential biomarkers for cancer diagnosis and prognosis, methods for detecting miRNAs with high sensitivity, selectivity, and stability are urgently needed. Various nucleic acid probes that have traditionally been for this purpose suffer several drawbacks, including inefficient signal-to-noise ratios and intensities, high cost, and time-consuming method establishment. Computing tools used for investigating the thermodynamics of DNA hybridization reactions can accurately predict the secondary structure of DNA and the interactions between DNA molecules. Herein, NUPACK was used to design a series of nucleic acid probes and develop a phosphorothioated-terminal hairpin formation and self-priming extension (PS-THSP) signal amplification strategy, which enabled the ultrasensitive detection of miR-200a in serum samples. The free and binding energies of the DNA detection probes calculated using NUPACK, as well as the biological experimental results, were considered synthetically to select the best sequence and experimental conditions. A unified dynamic programming framework, NUPACK analysis and the experimental data, were complementary and improved the designed model in all respects. Our study demonstrates the feasibility of using computer technology such as NUPACK to simplify the experimental process and provide intuitive results.

An Alternating Current Electroosmotic Flow-Based Ultrasensitive Electrochemiluminescence Microfluidic System for Ultrafast Monitoring, Detection of Proteins/miRNAs in Unprocessed Samples

Early diagnosis of acute diseases is restricted by the sensitivity and complex process of sample treatment. Here, an ultrasensitive, rapid, and portable electrochemiluminescence-microfluidic (ECL-M) system is described via sandwich-type immunoassay and surface plasmonic resonance (SPR) assay. Using a sandwich immunoreaction approach, the ECL-M system employs cardiac troponin-I antigen (cTnI) as a detection model with a Ru@SiO2 NPs labeled antibody as the signal probe. For miR-499-5p detection, gold nanoparticles generate SPR effects to enhance Ru(bpy)3 2+ ECL signals. The system based on alternating current (AC) electroosmotic flow achieves an LOD of 2 fg mL-1 for cTnI in 5 min and 10 aM for miRNAs in 10 min at room temperature. The point-of-care testing (POCT) device demonstrated 100% sensitivity and 98% specificity for cTnI detection in 123 clinical serum samples. For miR-499-5p, it exhibited 100% sensitivity and 97% specificity in 55 clinical serum samples. Continuous monitoring of these biomarkers in rats' saliva, urine, and interstitial fluid samples for 48 hours revealed observations rarely documented in biotic fluids. The ECL-M POCT device stands as a top-performing system for ECL analysis, offering immense potential for ultrasensitive, rapid, highly accurate, and facile detection and monitoring of acute diseases in POC settings.

miRNAs in Heart Development and Disease

Cardiovascular diseases (CVD) are a group of disorders that affect the heart and blood vessels. They include conditions such as myocardial infarction, coronary artery disease, heart failure, arrhythmia, and congenital heart defects. CVDs are the leading cause of death worldwide. Therefore, new medical interventions that aim to prevent, treat, or manage CVDs are of prime importance. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the posttranscriptional level and play important roles in various biological processes, including cardiac development, function, and disease. Moreover, miRNAs can also act as biomarkers and therapeutic targets. In order to identify and characterize miRNAs and their target genes, scientists take advantage of computational tools such as bioinformatic algorithms, which can also assist in analyzing miRNA expression profiles, functions, and interactions in different cardiac conditions. Indeed, the combination of miRNA research and bioinformatic algorithms has opened new avenues for understanding and treating CVDs. In this review, we summarize the current knowledge on the roles of miRNAs in cardiac development and CVDs, discuss the challenges and opportunities, and provide some examples of recent bioinformatics for miRNA research in cardiovascular biology and medicine.

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.

Panoramic on Epigenetics in Coronary Artery Disease and the Approach of Personalized Medicine

Epigenetic modifications play a fundamental role in the progression of coronary artery disease (CAD). This panoramic review aims to provide an overview of the current understanding of the epigenetic mechanisms involved in CAD pathogenesis and highlights the potential implications for personalized medicine approaches. Epigenetics is the study of heritable changes that do not influence alterations in the DNA sequence of the genome. It has been shown that epigenetic processes, including DNA/histone methylation, acetylation, and phosphorylation, play an important role. Additionally, miRNAs, lncRNAs, and circRNAs are also involved in epigenetics, regulating gene expression patterns in response to various environmental factors and lifestyle choices. In the context of CAD, epigenetic alterations contribute to the dysregulation of genes involved in inflammation, oxidative stress, lipid metabolism, and vascular function. These epigenetic changes can occur during early developmental stages and persist throughout life, predisposing individuals to an increased risk of CAD. Furthermore, in recent years, the concept of personalized medicine has gained significant attention. Personalized medicine aims to tailor medical interventions based on an individual's unique genetic, epigenetic, environmental, and lifestyle factors. In the context of CAD, understanding the interplay between genetic variants and epigenetic modifications holds promise for the development of more precise diagnostic tools, risk stratification models, and targeted therapies. This review summarizes the current knowledge of epigenetic mechanisms in CAD and discusses the fundamental principles of personalized medicine.

Exosomal microRNA‑4516, microRNA‑203 and SFRP1 are potential biomarkers of acute myocardial infarction

Acute myocardial infarction (AMI) is a serious disease which threatens public health. Exosomes (exos) contain certain genetic information and are important communication vehicles between cells. In the present study, different exosomal microRNAs (miRs), which exhibit a notable association between expression levels in plasma and AMI were assessed to support the development of new diagnostic and clinical assessment markers of patients with AMI. In total, 93 individuals, including 31 healthy controls and 62 patients with AMI, were recruited for the present study. Data on age, blood pressure, glucose levels, lipid levels and coronary angiography images were collected from the enrolled individuals, and plasma samples were collected. Plasma exos were extracted and verified using ultracentrifugation, transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blotting (WB). Exo‑miR‑4516 and exo‑miR‑203 in plasma exos were identified by exosomal miRNA sequencing analysis, reverse transcription‑quantitative PCR was performed to detect the levels of exo‑miR‑4516 and exo‑miR‑203 in plasma exos, and ELISA was performed to detect the levels of secretory frizzled‑related protein 1 (SFRP1) in samples. The correlation analysis between exo‑miR‑4516, exo‑miR‑203 and SFRP1 in plasma exos and AMI was presented as receiver operating characteristic curves (ROCs) of the SYNTAX score, cardiac troponin I (cTnI), low‑density lipoprotein (LDL) and each indicator separately. Kyoto Encyclopedia of Genes and Genomes enrichment analysis was performed to predict relevant enrichment pathways. Exos were successfully isolated from plasma by ultracentrifugation, which was confirmed by TEM, NTA and WB. Exo‑miR‑4516, exo‑miR‑203 and SFRP1 levels in plasma were significantly higher in the AMI group compared with the healthy control group. ROCs demonstrated that exo‑miR‑4516, exo‑miR‑203 and SFRP1 levels had a high diagnostic efficiency in predicting AMI. Exo‑miR‑4516 was positively correlated with SYNTAX score, and plasma SFRP1 was positively correlated with plasma cTnI and LDL. In conclusion, the data demonstrated that exo‑miR‑4516, exo‑miR‑203 and SFRP1 levels could be used in combination to diagnose and assess the severity of AMI. The present study was retrospectively registered (TRN, NCT02123004).

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.

Diagnostic potential of a circulating miRNA model associated with therapeutic effect in heart failure

Heart failure (HF), as the leading cause of death, is continuing to increase along with the aging of the general population all over the world. Identification of diagnostic biomarkers for early detection of HF is considered as the most effective way to reduce the risk and mortality. Herein, we collected plasma samples from HF patients (n = 40) before and after medical therapy to determine the change of circulating miRNAs through a quantitative real-time PCR (QRT-PCR)-based miRNA screening analysis. miR-30a-5p and miR-654-5p were identified as the most significantly changed miRNAs in the plasma of patients upon treatment. In consistence, miR-30a-5p showed upregulation and miR-654-5p showed downregulation in the circulation of 30 HF patients, compared to 15 normal controls in the training phase, from which a two-circulating miRNA model was developed for HF diagnosis. Next, we performed the model validation using an independent cohort including 50 HF patients and 30 controls. As high as 98.75% of sensitivity and 95.00% of specificity were achieved. A comparison between the miRNA model and NT-pro BNP in diagnostic accuracy of HF indicated an upward trend of the miRNA model. Moreover, change of the two miRNAs was further verified in association with the therapeutic effect of HF patients, in which miR-30a-5p showed decrease while miR-654-5p showed increase in the plasma of patients after LVAD implantation. In conclusion, the current study not only identified circulating miR-654-5p for the first time as a novel biomarker of HF, but also developed a novel 2-circulating miRNA model with promising potentials for diagnosis and prognosis of HF patients, and in association with therapeutic effects as well.

Tanshinone IIA improves cardiac function via regulating miR-499-5p dependent angiogenesis in myocardial ischemic mice

BACKGROUND/AIMS

Myocardial ischemia-reperfusion injury leads to aggravated cardiac remodeling and heart failure. After myocardial infarction (MI), angiogenesis plays a vital role in the repair and regeneration of tissue. The purpose of the current study was to determine the effect of Tanshinone IIA (Tan IIA) on angiogenesis and elucidate its related mechanism.

METHODS

The C57BL/6 mice MI model was established to evaluate the therapeutic effect of Tan IIA in vivo. MicroRNA (miRNA) microarray and bioinformatics analysis were performed to determine the differential expressions of miRNAs after Tan IIA administration. Cell proliferation, migration, and angiogenesis capacity were detected by EdU, Transwell, and Tube formation assay in vitro, respectively. The relationship between miR-499-5p (miR-499) and paired phosphate and tension homolog deleted on chromosome ten (PTEN) was confirmed by using a Dual-luciferase reporter assay.

RESULTS

Our results showed that Tan IIA administration improved cardiac function after MI by activating angiogenesis. Further miRNA microarray and bioinformatics analysis revealed that miR-499 was significantly down-regulated, while PTEN was remarkably upregulated after Tan IIA administration post-MI. In addition, we found that miR-499 knock-down effectively promotes cell proliferation, migration, and tube formation ability of HUVECs. Dual-luciferase reporter assay demonstrated that PTEN contains a direct binding site for miR-499-5p.

CONCLUSION

Tan IIA improves cardiac function post-MI by inducing angiogenesis. In terms of the mechanism, Tan IIA promotes therapeutic angiogenesis by regulating miR-499-5p/PTEN signaling pathway.

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.

Circulating microRNAs as predictive biomarkers of coronary artery diseases in type 2 diabetes patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) is an increasing metabolic disorder mostly resulting from unhealthy lifestyles. T2DM patients are prone to develop heart conditions such as coronary artery disease (CAD) which is a major cause of death in the world. Most clinical symptoms emerge at the advanced stages of CAD; therefore, establishing new biomarkers detectable in the early stages of the disease is crucial to enhance the efficiency of treatment. Recently, a significant body of evidence has shown alteration in miRNA levels associate with dysregulated gene expression occurring in T2DM and CAD, highlighting significance of circulating miRNAs in early detection of CAD arising from T2DM. Therefore, it seems crucial to establish a link between the miRNAs prognosing value and development of CAD in T2DM.

AIM

This study provides an overview on the alterations of the circulatory miRNAs in T2DM and various CADs and consider the potentials of miRNAs as biomarkers prognosing CADs in T2DM patients.

MATERIALS AND METHODS

Literature search was conducted for miRNAs involved in development of T2DM and CAD using the following key words: "miRNAs", "Biomarker", "Diabetes Mellitus Type 2 (T2DM)", "coronary artery diseases (CAD)". Articles written in the English language.

RESULT

There has been shown a rise in miR-375, miR-9, miR-30a-5p, miR-150, miR-9, miR-29a, miR-30d, miR-34a, miR-124a, miR-146a, miR-27a, and miR-320a in T2DM; whereas, miR-126, miR-21, miR-103, miR-28-3p, miR-15a, miR-145, miR-375, miR-223 have been shown to decrease. In addition to T2DM, some miRNAs such as mirR-1, miR-122, miR-132, and miR-133 play a part in development of subclinical aortic atherosclerosis associated with metabolic syndrome. Some miRNAs increase in both T2DM and CAD such as miR-1, miR-132, miR-133, and miR-373-3-p. More interestingly, some of these miRNAs such as miR-92a elevate years before emerging CAD in T2DM.

CONCLUSION

dysregulation of miRNAs plays outstanding roles in development of T2DM and CAD. Also, elevation of some miRNAs such as miR-92a in T2DM patients can efficiently prognose development of CAD in these patients, so these miRNAs can be used as biomarkers in this regard.

Heart-specific DNA methylation analysis in plasma for the investigation of myocardial damage

Background

Circulating cell-free DNA (cfDNA) can be released when myocardial damage occurs.

Methods

Here, we used the methylated CpG tandem amplification and sequencing (MCTA-seq) method for analyzing dynamic changes in heart-derived DNA in plasma samples from myocardial infarction (MI) patients.

Results

We identified six CGCGCGG loci showing heart-specific hypermethylation patterns. MCTA-seq deconvolution analysis combining these loci detected heart-released cfDNA in MI patients at hospital admission, and showed that the prominently elevated total cfDNA level after percutaneous coronary intervention (PCI) was derived from both the heart and white blood cells. Furthermore, for the top marker CORO6, we developed a digital droplet PCR (ddPCR) assay that clearly detected heart damage signals in cfDNA of MI patients at hospital admission.

Conclusions

Our study provides insights into MI pathologies and developed a new ddPCR assay for detecting myocardial damage in clinical applications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03234-9.

Diagnostic and Prognostic Value of miRNAs after Coronary Artery Bypass Grafting: A Review

MiRNAs are noncoding, 21-24 nucleotide-long RNA particles that control over 60% of genes. MiRNAs affect gene expression through binding to the 3'-untranslated region of messenger RNA (mRNA), thus inhibiting mRNA translation or inducing mRNA degradation. MiRNAs have been associated with various cardiovascular diseases, including heart failure, hypertension, left ventricular hypertrophy, or ischemic heart disease. In addition, miRNA expression alters during coronary artery bypass grafting (CABG) surgery, which could be used to predict perioperative outcomes. CABG is an operation in which complex coronary arteries stenosis is treated by bypassing atherosclerotic lesions with venous or arterial grafts. Despite a very low perioperative mortality rate and excellent long-term survival, CABG is associated with postoperative complications, including reperfusion injury, graft failure, atrial fibrillation and perioperative myocardial infarction. So far, no reliable diagnostic and prognostic tools to predict prognosis after CABG have been developed. Changes in the perioperative miRNA expression levels could improve the diagnosis of post-CABG myocardial infarction and atrial fibrillation and could be used to stratify risk after CABG. Herein, we describe the expression changes of different subtypes of miRNAs during CABG and review the diagnostic and prognostic utility of miRNAs in patients undergoing CABG.

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.

Can miRNAs Serve as Potential Markers in Thermal Burn Injury: An In Silico Approach

Burn injury has been a major cause of morbidity at global levels. They can occur by multiple agents, such as thermal radiation and chemicals. Among all, thermal burn is predominant and may require specialized treatment in some patients. Although various biomarkers are reportedly used in thermal burn for understanding the pathophysiology of the injury, their limitations prompt for the search of suitable markers that can address the depth and severity of the burn. MicroRNAs (miRNAs) are conserved noncoding molecules that seem to be the promising marker due to their role in multiple pathways and participation in different physiological processes of the body. The present review highlights the role of miRNAs in the repair of the wound and their interaction with specific genes in response to burn stress. Key miR candidates include miR-21, miR-29a, miR-378a-5p, miR-100, miR-27b, miR-200c, miR-150, miR-499-5p, miR-92a, miR-194, and miR-146b, which are identified for their respective targets involved in wound repair. Furthermore, bioinformatics and computational tools were used to confirm the miRNAs and their specific targets. Gene and miRNA expression data sets were downloaded from Research Collaboratory for Structural Bioinformatics Protein Data Bank Database and RNAComposer, respectively, and docked by PatchDock. The possible implications of the identified miRNAs could be in understanding the mechanism of burn injury. These can also be studied with the available drugs being used for burn injury. Apart from that, new intended molecules may also be tested for their effect on these miRNAs.

Screening and identification of potential protein biomarkers for the early diagnosis of acute myocardial infarction

Background

Acute myocardial infarction (AMI) is the most serious type of heart disease. Clinically, there is an urgent need to discover diagnostic biomarkers for the early diagnosis of AMI.

Methods

Serum proteomic profiles in AMI patients, healthy controls, and stable angina pectoris (SAP) patients were explored and compared by iTRAQ-2DLC-MS/MS. The clinical data of AMI patients were also analyzed. Differentially expressed proteins were validated by enzyme linked immunosorbent assay (ELISA), and diagnostic models were constructed.

Results

A total of 39 differentially expressed proteins were identified in AMI patients. The results showed that the serum levels of apolipoprotein E (APOE) in AMI patients were notably higher than those in the healthy controls (P=0.0172). The serum levels of aspartate aminotransferase (AATC) in AMI patients were markedly higher than those in the healthy controls and SAP patients (P<0.0001 and P<0.0001, respectively). The serum levels of fibronectin (FINC) in SAP patients were significantly higher than those in the healthy controls and AMI patients (P=0.0043 and P=0.0044, respectively). Clinical data analysis showed a considerable difference in blood glucose levels, troponin I (TNI), and creatine kinase (CK) in AMI patients compared with SAP patients and healthy controls. A diagnostic model consisting of AATC and clinical indicators [lactate dehydrogenase (LDH) and CK] was established to distinguish between AMI patients and healthy controls, with an area under the curve (AUC) value of 0.993 sensitivity and specificity of 96.2% and 96.3%, respectively. A diagnostic model consisting of AATC and CK was established to distinguish between AMI patients and SAP patients, with an AUC value of 0.975 and a sensitivity and specificity of 85.2% and 79.30%, respectively.

Conclusions

In this study, differentially expressed proteins in AMI patients were combined with clinical indexes, LDH and CK, and two diagnostic models were constructed. This study may provide meaningful data for the early diagnosis of AMI.

Elucidation of Epigenetic Landscape in Coronary Artery Disease: A Review on Basic Concept to Personalized Medicine

Despite extensive clinical research and management protocols applied in the field of coronary artery diseases (CAD), it still holds the number 1 position in mortality worldwide. This indicates that we need to work on precision medicine to discover the diagnostic, therapeutic, and prognostic targets to improve the outcome of CAD. In precision medicine, epigenetic changes play a vital role in disease onset and progression. Epigenetics is the study of heritable changes that do not affect the alterations of DNA sequence in the genome. It comprises various covalent modifications that occur in DNA or histone proteins affecting the spatial arrangement of the DNA and histones. These multiple modifications include DNA/histone methylation, acetylation, phosphorylation, and SUMOylation. Besides these covalent modifications, non-coding RNAs-viz. miRNA, lncRNA, and circRNA are also involved in epigenetics. Smoking, alcohol, diet, environmental pollutants, obesity, and lifestyle are some of the prime factors affecting epigenetic alterations. Novel molecular techniques such as next-generation sequencing, chromatin immunoprecipitation, and mass spectrometry have been developed to identify important cross points in the epigenetic web in relation to various diseases. The studies regarding exploration of epigenetics, have led researchers to identify multiple diagnostic markers and therapeutic targets that are being used in different disease diagnosis and management. Here in this review, we will discuss various ground-breaking contributions of past and recent studies in the epigenetic field in concert with coronary artery diseases. Future prospects of epigenetics and its implication in CAD personalized medicine will also be discussed in brief.

Diagnostic and prognostic value of circulating miRNA-499 and miRNA-22 in acute myocardial infarction

BACKGROUND

Currently, acute myocardial infarction (AMI) represents a serious cardiovascular disease with high morbidity and mortality. Therefore, this study aimed to systematically evaluate the roles of miRNA-499 and miRNA-22 as potential biomarkers for AMI.

METHODS

According to the inclusion and exclusion criteria, we measured circulating levels of miRNAs in 50 AMI patients and 50 non-MI populations. The expression levels of plasma miRNA-499 and miRNA-22 were analyzed by real-time fluorescent quantitative polymerase chain reaction (qRT-PCR). A statistical analysis of clinical data of AMI patients was conducted by 90-day follow-up.

RESULTS

Real-time PCR analysis showed that the relative expression level of miRNA-499 increased gradually among the three groups (P < .05). However, the expression of miRNA-22 showed a downward trend (P < .05). According to logistic analysis, the relative levels of miRNA-499 and miRNA-22 were important predictors of AMI. When the miRNA-499 and miRNA-22 levels were 0.377 and 0.946 separately, the diagnostic value of miRNA-499 and miRNA-22 for AMI was 86.00% and 86.00% for sensitivity, and 98.00% and 94.00% for specificity, respectively. In addition, compared to the baseline GRACE scoring system, the combination of miRNA-499, miRNA-22, and GRACE scores had a stronger discriminating power for MACE occurrence, with a sensitivity of 100.00% and a specificity of 79.40%.

CONCLUSIONS

The results showed that plasma miRNA-499 and miRNA-22 were more sensitive and specific for the diagnosis of AMI, suggesting that they can be used as potential biomarkers for clinical diagnosis of AMI.

Ischemic postconditioning attenuates the inflammatory response in ischemia/reperfusion myocardium by upregulating miR‑499 and inhibiting TLR2 activation

Toll-like receptor 2 (TLR2)-mediated myocardial inflammation serves an important role in promoting myocardial ischemic/reperfusion (I/R) injury. Previous studies have shown that miR-499 is critical for cardioprotection after ischemic postconditioning (IPostC). Therefore, the present study evaluated the protective effect of IPostC on the myocardium by inhibiting TLR2, and also assessed the involvement of microRNA (miR)-499. Rat hearts were subjected to 30 min of ischemia and 2 h of reperfusion. The IPostC was 3 cycles of 30 sec of reperfusion and 30 sec of re-occlusion prior to reperfusion. In total, 90 rats were randomly divided into six groups (n=15 per group): Sham; I/R; IPostC; miR-499 negative control adeno-associated virus (AAV) vectors + IPostC; miR-499 inhibitor AAV vectors + IPostC; and miR-499 mimic AAV vectors + IPostC. It was identified that IPostC significantly decreased the I/R-induced cardiomyocyte apoptotic index (29.4±2.03% in IPostC vs. 42.64±2.27% in I/R; P<0.05) and myocardial infarct size (48.53±2.49% in IPostC vs. 66.52±3.1% in I/R; P<0.05). Moreover, these beneficial effects were accompanied by increased miR-499 expression levels (as demonstrated by reverse transcription-quantitative PCR) in the myocardial tissue and decreased TLR2, protein kinase C (PKC), interleukin (IL)-1β and IL-6 expression levels (as demonstrated by western blotting and ELISA) in the myocardium and serum. The results indicated that IPostC + miR-499 mimics significantly inhibited inflammation and the PKC signaling pathway and enhanced the anti-inflammatory and anti-apoptotic effects of IPostC. However, IPostC + miR-499 inhibitors had the opposite effect. Therefore, it was speculated that IPostC may have a miR-499-dependent cardioprotective effect. The present results suggested that miR-499 may be involved in IPostC-mediated ischemic cardioprotection, which may occur via local and systemic TLR2 inhibition, subsequent inhibition of the PKC signaling pathway and a decrease in inflammatory cytokine release, including IL-1β and IL-6. Moreover, these effects will ultimately lead to a decrease in the myocardial apoptotic index and myocardial infarct size via the induction of the anti-apoptotic protein Bcl-2, and inhibition of the pro-apoptotic protein Bax in myocardium.

Enhanced peripheral blood miR-324-5p is associated with the risk of metabolic syndrome by suppressing ROCK1

The current study aims to evaluate whether peripheral blood miR-324-5p could be used to differentiate patients with metabolic disorders and healthy controls. Our data showed that miR-324-5p levels were elevated in the peripheral blood of patients with hyperglycemia or hyperlipidemia. In addition, the expression of miR-324-5p was enhanced in the peripheral blood and liver of db/db mice. Further study indicated that overexpression of miR-324-5p reduced the activation of the AKT/GSK pathway and increased lipid accumulation, while the inhibition of miR-324-5p activated the AKT/GSK pathway and decreased lipid accumulation. A dual luciferase assay revealed that Rho-associated coiled-coil containing protein kinase 1 (ROCK1) was a target gene of miR-324-5p. In addition, silencing ROCK1 deteriorated lipid and glucose metabolism. More importantly, knockdown of ROCK1 reversed the miR-324-5p inhibitor-induced improvement of glucose and lipid metabolism. In summary, miR-324-5p plays a regulatory role in glucose and lipid metabolism by targeting ROCK1, which is involved in metabolic disorders. The use of miR-324-5p in diagnosing metabolic syndrome is worth investigating and may benefit patients.

Mitochondrial DNA Copy Number in Peripheral Blood Is Reduced in Type 2 Diabetes Patients with Polyneuropathy and Associated with a MIR499A Gene Polymorphism

Our aim was to evaluate in a cohort of 125 Italian patients with type 2 diabetes (T2D), who underwent neurological evaluation, the possible differences in the number of mitochondrial DNA copies (mtDNA) comparing positive and negative patients for cardiovascular autonomic neuropathy (CAN) or diabetic peripheral neuropathy (DPN) and comparing them with healthy controls. We also investigated a possible correlation of the number of mtDNA copies with the polymorphism rs3746444 of the MIR499A. T2D patients show a decrease in the number of mtDNA copies compared to healthy controls (p = 2 × 10^-10). Dividing the T2D subjects by neurological evaluation, we found a significant mtDNA decrease in patients with DPN compared with those without (p = 0.02), while no differences were observed between subjects with and without CAN. Furthermore, the homozygous variant genotype for the polymorphism rs3746444 of MIR499A correlates with a decrease in the number of mtDNA copies, particularly in T2D patients (p = 0.009). Our data show a decrease in the number of mtDNA copies in subjects with T2D and suggest that this decrease is more evident in patients who develop DPN. Furthermore, the association of the variant allele of MIR499A with the number of mtDNA copies allows us to hypothesize a possible effect of this polymorphism in oxidative stress.

microRNA profiling in the Weddell seal suggests novel regulatory mechanisms contributing to diving adaptation

Background

The Weddell Seal (Leptonychotes weddelli) represents a remarkable example of adaptation to diving among marine mammals. This species is capable of diving > 900 m deep and remaining underwater for more than 60 min. A number of key physiological specializations have been identified, including the low levels of aerobic, lipid-based metabolism under hypoxia, significant increase in oxygen storage in blood and muscle; high blood volume and extreme cardiovascular control. These adaptations have been linked to increased abundance of key proteins, suggesting an important, yet still understudied role for gene reprogramming.

In this study, we investigate the possibility that post-transcriptional gene regulation by microRNAs (miRNAs) has contributed to the adaptive evolution of diving capacities in the Weddell Seal.

Results

Using small RNA data across 4 tissues (brain, heart, muscle and plasma), in 3 biological replicates, we generate the first miRNA annotation in this species, consisting of 559 high confidence, manually curated miRNA loci. Evolutionary analyses of miRNA gain and loss highlight a high number of Weddell seal specific miRNAs.

Four hundred sixteen miRNAs were differentially expressed (DE) among tissues, whereas 80 miRNAs were differentially expressed (DE) across all tissues between pups and adults and age differences for specific tissues were detected in 188 miRNAs. mRNA targets of these altered miRNAs identify possible protective mechanisms in individual tissues, particularly relevant to hypoxia tolerance, anti-apoptotic pathways, and nitric oxide signal transduction. Novel, lineage-specific miRNAs associated with developmental changes target genes with roles in angiogenesis and vasoregulatory signaling.

Conclusions

Altogether, we provide an overview of miRNA composition and evolution in the Weddell seal, and the first insights into their possible role in the specialization to diving.

Potential Impact of MicroRNA Gene Polymorphisms in the Pathogenesis of Diabetes and Atherosclerotic Cardiovascular Disease

MicroRNAs (miRNAs) are endogenous, small (18–23 nucleotides), non-coding RNA molecules. They regulate the posttranscriptional expression of their target genes. MiRNAs control vital physiological processes such as metabolism, development, differentiation, cell cycle and apoptosis. The control of the gene expression by miRNAs requires efficient binding between the miRNA and their target mRNAs. Genome-wide association studies (GWASs) have suggested the association of single-nucleotide polymorphisms (SNPs) with certain diseases in various populations. Gene polymorphisms of miRNA target sites have been implicated in diseases such as cancers, diabetes, cardiovascular and Parkinson’s disease. Likewise, gene polymorphisms of miRNAs have been reported to be associated with diseases. In this review, we discuss the SNPs in miRNA genes that have been associated with diabetes and atherosclerotic cardiovascular disease in different populations. We also discuss briefly the potential underlining mechanisms through which these SNPs increase the risk of developing these diseases.

Preoperative miRNA-208a as a Predictor of Postoperative Complications in Children with Congenital Heart Disease Undergoing Heart Surgery

Major perioperative cardiovascular events are important causes of morbidity in pediatric patients with congenital heart disease who undergo reparative surgery. Current preoperative clinical risk assessment strategies have poor accuracy for identifying patients who will sustain adverse events following heart surgery. There is an ongoing need to integrate clinical variables with novel technology and biomarkers to accurately predict outcome following pediatric heart surgery. We tested whether preoperative levels of miRNAs-208a can serve as such a biomarker. Serum samples were obtained from pediatric patients immediately before heart surgery. MiRNA-208a was quantified by RQ-PCR. Correlations between the patient's clinical variables and miRNA levels were tested. Lower levels of preoperative miRNA-208a correlated with and could predict the appearance of postoperative cardiac and inflammatory complications. MiRNA-208a may serve as a biomarker for the prediction of patients who are at risk to develop complications following surgery for the repair of congenital heart defects.

MicroRNAs in Cardiac Diseases

Since their discovery 20 years ago, microRNAs have been related to posttranscriptional regulation of gene expression in major cardiac physiological and pathological processes. We know now that cardiac muscle phenotypes are tightly regulated by multiple noncoding RNA species to maintain cardiac homeostasis. Upon stress or various pathological conditions, this class of non-coding RNAs has been found to modulate different cardiac pathological conditions, such as contractility, arrhythmia, myocardial infarction, hypertrophy, and inherited cardiomyopathies. This review summarizes and updates microRNAs playing a role in the different processes underlying the pathogenic phenotypes of cardiac muscle and highlights their potential role as disease biomarkers and therapeutic targets.

Reduction of miR-29a-3p induced cardiac ischemia reperfusion injury in mice via targeting Bax

The current study mainly aimed to evaluate the expression and the potential mechanism of miR-29a-3p in the hearts of mice after cardiac ischemia reperfusion (CIR) injury. Quantitative PCR was carried out to assess the relative levels of miR-29a-3p in the hearts of a CIR injury mouse model. To the best of our knowledge, the current study is the first to show that the level of miR-29a-3p was significantly decreased in the hearts of CIR injury mouse models compared with that of sham controls. Moreover, the authors found that decreased miR-29a-3p levels enhanced the production of reactive oxygen species in cardiomyocytes. Meanwhile, the inhibition of miR-29a-3p induced substantial cardiomyocyte apoptosis. Further study showed that the inhibition of miR-29a-3p decreased the activation of Akt and p38, suggesting a stress-induced self-regulatory mechanism after CIR injury in primary cardiomyocytes. A dual luciferase assay and western blot analysis showed that Bax was a target gene of miR-29a-3p. The authors also measured the level of miR-29a-3p in the plasma of 100 acute myocardial infarction (AMI) patients and found that circulating miR-29a-3p was significantly decreased in AMI patients. Receiver operating characteristic curve analysis showed that miR-29a-3p could be used to screen AMI patients from healthy controls. Hence, the authors of the current study propose that reduced miR-29a-3p levels in primary cardiomyocytes contribute to CIR injury-related apoptosis mainly by targeting Bax.

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

Objective

MiR-499 has been reported to be expressed only in cardiomyocytes, and its expression would increase after acute myocardial infarction (AMI). miR-499 plays a role in the process of cardiomyocytes injury induced by hypoxia/reoxygenation (H/R), however, it still remains unclear.

Results

Hypoxia inhibited miR-499-5p expression and H/R induced apoptosis. SOX6 was a target gene of miR-499-5p, and high expression of miR-499-5p inhibited the expression of SOX6. MiR-499-5p reduced H9c2 cells injury by inhibiting the expression of SOX6, overexpression of which could reverse the effect of miR-499-5p on H9c2 cells. MiR-499-5p inhibited the levels of LDH and MDA, while overexpression of miR-499-5p inhibited H/R-induced cell apoptosis. MiR-499-5p could up-regulate the level of Bcl-2 and down-regulate the expression levels of Bax and caspase-3. However, SOX6 partially reversed these effects of miR-499-5p.

Conclusion

We proved that miR-499-5p inhibited H/R-induced cardiomyocytes injury by targeting SOX6. Our results suggested that miR-499-5p/SOX6 pathway may present a potential therapeutic target for the treatment of AMI.

Role of miRNAs on the Pathophysiology of Cardiovascular Diseases

MiRNA (or microRNA) is a subclass of non-coding RNAs that is responsible for post-transcriptional gene regulation. It has approximately 22 nucleotides and regulates gene expression in plants and animals at the post-transcriptional level, by the cleavage of a target mRNA or by suppression of its translation. Although many of the processes and mechanisms have not yet been fully elucidated, there is a strong association between miRNA expression and several diseases. It is known that miRNAs are expressed in the cardiovascular system, but their role in cardiovascular diseases (CVDs) has not been clearly established. In this non-systematic review of the literature, we first present the definition of miRNAs and their action at the cellular level. Afterward, we discuss the role of miRNAs as circulating biomarkers of CVDs, and then their role in cardiac remodeling and atherosclerosis. Despite the complexity and challenges, it is crucial to identify deregulated miRNAs in CVDs, as it allows a better understanding of underlying cellular and molecular mechanisms and helps in the development of more accurate diagnostic and prognostic circulating biomarkers, and new therapeutic strategies for different stages of CVDs.

Circulating MicroRNA-499 as a Diagnostic Biomarker for Acute Myocardial Infarction: A Meta-analysis

Background

Recent studies have shown that circulating microRNA-499 could be a powerful biomarker of acute myocardial infarction (AMI). Interest in circulating microRNA-499 for detecting AMI is increasing rapidly. To evaluate the diagnosis of circulating microRNA-499 for AMI, this study was performed.

Methods

We searched PubMed, Embase, and the Cochrane Library for studies published up to December 31, 2018, as well as the reference lists of relevant studies. Studies were included if they assessed the accuracy of blood circulating microRNA-499 or cardiac troponin T (cTnT) for AMI and provided sufficient data to construct a 2 × 2 contingency table. Extracted data were analysed for sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operator curve (SROC) analyses. Prespecified subgroup analysis and metaregression were also performed.

Results

Fourteen studies including 3816 participants were included in this meta-analysis. The overall pooled sensitivity and specificity were 0.84 (95% CI: 0.64-0.94) and 0.97 (95% CI: 0.90-0.99), respectively. The area under the SROC curve (AUC) was 0.98 (95% CI: 0.96-0.99). The studies had substantial heterogeneity (I² = 98.74%). Seven studies also used cTnT as a marker for the diagnosis of AMI. The overall pooled sensitivity and specificity of cTnT were 0.95 (95% CI: 0.87-0.98) and 0.96 (95% CI: 0.85-0.99), respectively. The area under the SROC curve (AUC) was 0.99 (95% CI: 0.97-0.99). The DOR of circulating miR-499 and cTnT were 188 (95% CI: 19-1815) and 420 (95% CI: 86-2038), respectively. Metaregression analysis suggested that specimen and healthy controls were the main sources of heterogeneity. No publication bias was suggested by Deeks' regression test of asymmetrical funnel plot (t = 0.85; p value = 0.41).

Conclusion

The results showed that circulating microRNA-499 is a reliable biomarker for diagnosing AMI patients.

Reactive Oxygen Species Related Noncoding RNAs as Regulators of Cardiovascular Diseases

Reactive oxygen species (ROS) are a class of reactive molecules that have been implicated in a variety of cardiovascular diseases, accompanied by disorder of multiple signaling events. As cardiomyocytes maintain abundant of mitochondria, which supply the major source of endogenous ROS, oxidative damage to mitochondria often drives apoptotic cell death and initiates cardiac pathology. In recent years, non-coding RNAs (ncRNAs) have received much attention to uncover their roles in regulating gene expression during those pathological events in the heart, such as myocardial infarction, cardiac hypertrophy, and heart failure. Emerging evidences have highlighted that different ROS levels in response to diverse cardiac stresses result in differential expression of ncRNAs, subsequently altering the expression of pathogenetic genes. However, the knowledge about the ncRNA-linked ROS regulatory mechanisms in cardiac pathologies is still largely unexplored. In this review, we summarize the connections that exist among ROS, ncRNAs, and cardiac diseases to understand the interactions among the molecular entities underlying cardiac pathological events in the hopes of guiding novel therapies for heart diseases in the future.

miRNA Polymorphisms and Risk of Cardio-Cerebrovascular Diseases: A Systematic Review and Meta-Analysis

Recently extensive focus has been concentrated on the role of miRNAs in the initiation and progression of cardio-cerebrovascular diseases (CCDs) which constitute a range of conditions including cardiovascular diseases (CVDs, especially coronary artery disease (CAD)), congenital heart disease (CHD) and cerebrovascular diseases (CBVDs, especially the ischemic stroke (IS)). An increasing number of studies are evaluating the association between different miRNA polymorphisms and risk of CCDs, but results have been inconclusive. This study represents a comprehensive systematic review and meta-analysis of the association between miRNA polymorphisms and risk of CCDs. PubMed, Embase, Scopus, and Web of Science were queried to identify eligible articles. Odds ratios and 95% confidence intervals were used to assess the association of miRNA polymorphisms with CCD susceptibility. A total of 51 eligible articles evaluating the association of 31 miRNA polymorphisms were identified. Meta-analysis was performed for six miRNA polymorphisms. miR-146a rs2910164 (30 studies: 13,186 cases/14,497 controls), miR-149 rs2292832 (Nine studies: 4116 cases/3511 controls), miR-149 rs71428439 (Three studies: 1556 cases/1567 controls), miR-196a2 rs11614913 (20 studies: 10,144 cases/10,433 controls), miR-218 rs11134527 (Three studies: 2,322 cases/2,754 controls) were not associated with overall CCD. miR-499 rs3746444 was associated with CCD (20 studies: 9564 cases/8876 controls). In the subgroups, rs2910164 and rs3746444 were only associated with CVDs, especially CAD. In conclusion, the results support the existence of a role for miR-146a rs2910164 and miR-499 rs3746444 in determining susceptibility to CCDs, especially CAD.

Propofol Protects Rat Cardiomyocytes from Anthracycline-Induced Apoptosis by Regulating MicroRNA-181a In Vitro and In Vivo

We aimed to evaluate the cardioprotective effect and mechanism of propofol in anthracycline-induced cardiomyocyte apoptosis. We selected the rat myocardial cell line, H9c2, and primary cardiomyocytes for in vitro study. The cardiomyocytes were treated with vehicle, Adriamycin® (ADM), propofol, or a combination of ADM and propofol. The proportion of apoptotic cells and the expression of miR-181a were detected by flow cytometry and real-time PCR, respectively. Luciferase assays were performed to explore the direct target gene of miR-181a. In vivo assay, rats were randomly divided into different treatment groups. The apoptosis index was determined by TUNEL staining, and the expression of miR-181a and STAT3 in heart tissue was detected. The antiproliferative effect of ADM alone was significantly greater than that of ADM plus propofol. A significantly greater decrease in the proportion of apoptotic cells and in miR-181a expression was observed in the combination treatment group compared with that in the ADM groups in vitro and in vivo. The loss-of-function of miR-181a in H9c2 of ADM treatment resulted in increased Bcl-2 and decreased Bax. MiR-181a suppressed Bcl-2 expression through direct targeting of the Bcl-2 transcript. Propofol reduced anthracycline-induced apoptosis in cardiomyocytes via targeting miR-181a/Bcl-2, and a negative correlation between miR-181a and Bcl-2 was observed.

Expression of miR-208b and miR-499 in Greek Patients with Acute Myocardial Infarction

BACKGROUND/AIM

Certain microRNAs (miRs) present in human plasma are candidate biomarkers for cardiovascular diseases, including acute myocardial infarction (AMI). We examined the expression of two cardiac-specific miRs (miR-208b and miR-499) in a Greek pathological population.

MATERIALS AND METHODS

Plasma samples from AMI patients and healthy subjects (controls) were analyzed using TaqMan® MicroRNA assays.

RESULTS

The concentration of both miRs was significantly elevated in AMI patients compared to healthy controls. Moreover, receiver-operating characteristic (ROC) curve analysis showed that miR-208b and miR-499 displayed similar properties with the established AMI biomarker cardiac troponin T (cTnT).

CONCLUSION

We showed, for the first time, that these miRs could be used as AMI biomarkers in our population as well. Our data are in agreement with those of studies based on different population groups and further strengthen the observation that plasma levels of circulating miR-208b and miR-499 could serve as potential AMI biomarkers.

Association between a MIR499A polymorphism and diabetic neuropathy in type 2 diabetes

AIMS

Diabetic polyneuropathy (DPN) and cardiovascular autonomic neuropathy (CAN) affect a large percentage of diabetic people and impact severely on quality of life. As it seems that miRNAs and their variations might play a role in these complications, we investigated whether the rs3746444 SNP in the MIR499A gene could be associated with susceptibility to DPN and/or CAN.

METHODS

We analyzed 150 participants with type 2 diabetes. DNA was extracted from peripheral blood samples and genotyping was performed by TaqMan genotyping assay. Cardiovascular tests, MNSI-Q and MDNS for neuropathic symptoms and signs, VPT, and thermal thresholds were used for CAN and DPN assessment. We performed a genotype-phenotype correlation analysis.

RESULTS

We observed that the GG genotype was associated with a higher risk of developing CAN (P=0.002 and OR=16.08, P=0.0005 and OR=35.02, for early and confirmed CAN, respectively) and DPN (P=0.037 and OR=6.56), after correction for BMI, sex, age, HbA1c and disease duration. Moreover, the GG genotype was associated with worse values of MDNS (P=0.017), VPT (P=0.01), thermal thresholds (P=0.01), and CAN score (P<0.001). A logistic multivariate analysis confirmed that MIR499A GG genotype, disease duration and HbA1c contributed to early CAN (R²=0.26), while the same variables and age contributed to DPN (R²=0.21). With a multiple linear regression, we observed that GG genotype (P=0.001) and disease duration (P=0.035) were the main variables contributing to the CAN score (R²=0.35).

CONCLUSIONS

We described for the first time that the MIR499A genetic variation could be involved in diabetic neuropathies susceptibility. In particular, patients carrying the rs3746444 GG genotype had a higher risk of CAN development, together with a more severe form of CAN.

MicroRNAs as potential prognosticators of neurological outcome in out-of-hospital cardiac arrest patients

Out-of-hospital cardiac arrest survival rates have increased due to advancement in resuscitative measures, yet approximately 90% of survivors ultimately die or have severe neurologic dysfunction caused by ischemic injury. Currently, there are few early prognostic indicators of which patients have possibility of meaningful recovery. This leads to uncertainty for families and clinicians, as well as aggressive, invasive and expensive treatments despite medical futility. Several biomarkers investigated in traumatic brain injury have shown prognostication potential in ischemic brain injury. miRNAs, small noncoding RNAs responsible for gene regulation, have been studied in cardiovascular diseases, and have shown prognostication potential due to tissue specificity and stability in circulation. This review discusses available evidence on miRNAs prognosticating neurological outcomes after out-of-hospital cardiac arrest.

miR-181a and miR-150 regulate dendritic cell immune inflammatory responses and cardiomyocyte apoptosis via targeting JAK1-STAT1/c-Fos pathway

The immune inflammatory response plays a crucial role in many cardiac pathophysiological processes, including ischaemic cardiac injury and the post-infarction repair process. MicroRNAs (miRNAs) regulate the development and function of dendritic cells (DCs), which are key players in the initiation and regulation of immune responses; however, the underlying regulatory mechanisms remain unclear. Here, we used the supernatants of necrotic primary cardiomyocytes (Necrotic-S) to mimic the myocardial infarction (MI) microenvironment to investigate the role of miRNAs in the regulation of DC-mediated inflammatory responses. Our results showed that Necrotic-S up-regulated the DC maturation markers CD40, CD83 and CD86 and increased the production of inflammatory cytokines, concomitant with the up-regulation of miR-181a and down-regulation of miR-150. Necrotic-S stimulation activated the JAK/STAT pathway and promoted the nuclear translocation of c-Fos and NF-κB p65, and silencing of STAT1 or c-Fos suppressed Necrotic-S-induced DC maturation and inflammatory cytokine production. The effects of Necrotic-S on DC maturation and inflammatory responses, its activation of the JAK/STAT pathway and the induction of cardiomyocyte apoptosis under conditions of hypoxia were suppressed by miR-181a or miR-150 overexpression. Taken together, these data indicate that miR-181a and miR-150 attenuate DC immune inflammatory responses via JAK1-STAT1/c-Fos signalling and protect cardiomyocytes from cell death under conditions of hypoxia.

miRNA Expression Profile and Effect of Wenxin Granule in Rats with Ligation-Induced Myocardial Infarction

Wenxin Granule (WXKL) is a traditional Chinese medicine used for treatment of myocardial infarction (MI) and arrhythmias. However, the genomic pathological mechanisms of MI and mechanisms of WXKL are largely unknown. This study aims to investigate a comprehensive miRNA expression profile, and the predicted correlation pathways to be targeted by differentially expressed miRNAs in MI, and mechanisms of WXKL from a gene level. MI rat model was established by a coronary artery ligation surgery. miRNA expression microarrays were performed and the data were deposited in Gene Expression Omnibus (GEO number GSE95855). And, pathway analysis was performed by using the DIANA-miRPath v3.0 online tool. The expressions of miR-1, miR-133, Cx43, and Cx45 were detected by quantitative real-time PCR. It was found that 35 differentially expressed miRNAs and 23 predicted pathways, including miR-1, miR-133, and gap junction pathway, are involved in the pathogenesis of MI. And, WXKL increased the expressions of miR-1 and miR-133, while also increased the mRNA levels of Cx43 and Cx45, and, especially, recovered the Cx43/Cx45 ratio near to normal level. The results suggest that regulatory effects on miR-1, miR-133, Cx43, and Cx45 might be a possible mechanism of WXKL in the treatment of MI at the gene level.

Long non-coding RNA MALAT1 functions as a mediator in cardioprotective effects of fentanyl in myocardial ischemia-reperfusion injury

Long non-coding (lncRNA) MALAT1 can be increased by hypoxia or ischemic limbs. Also, downregulation of MALAT1 contributes to reduction of cardiomyocyte apoptosis. However, the functional involvement of MALAT1 in myocardial ischemia-reperfusion (I/R) injury has not been defined. This study investigated the functional involvement of lncRNA-MALAT1 in cardioprotective effects of fentanyl. HL-1, a cardiac muscle cell line from the AT-1 mouse atrial cardiomyocyte tumor lineage was pre-treated with fentanyl and generated cell model of hypoxia-reoxygenation (H/R). Relative expression of MALAT1, miR-145, and Bnip3 mRNA in cells was determined by quantitative real-time PCR. Cardiomyocyte H/R injury was indicated by lactate dehydrogenase (LDH) release and cell apoptosis. The results showed that fentanyl abrogates expression of responsive gene for H/R and induces downregulation of MALAT1 and Bnip3 and upregulation of miR-145. We found that miR-145/Bnip3 pathway was negatively regulated by MALAT1 in H/R-HL-1 cell with or without fentanyl treatment. Moreover, both MALAT1 overexpression and miR-145 knockdown reverse cardioprotective effects of fentanyl, as indicated by increase in LDH release and cell apoptosis. The reversal effect of MALAT1 for fentanyl is confirmed in cardiac ischemia/reperfusion (I/R) mice. In summary, lncRNA-MALAT1 is sensitive to H/R injury and abrogates cardioprotective effects of Fentanyl by negatively regulating miR-145/Bnip3 pathway.

Advances in Integrating Traditional and Omic Biomarkers When Analyzing the Effects of the Mediterranean Diet Intervention in Cardiovascular Prevention

Intervention with Mediterranean diet (MedDiet) has provided a high level of evidence in primary prevention of cardiovascular events. Besides enhancing protection from classical risk factors, an improvement has also been described in a number of non-classical ones. Benefits have been reported on biomarkers of oxidation, inflammation, cellular adhesion, adipokine production, and pro-thrombotic state. Although the benefits of the MedDiet have been attributed to its richness in antioxidants, the mechanisms by which it exercises its beneficial effects are not well known. It is thought that the integration of omics including genomics, transcriptomics, epigenomics, and metabolomics, into studies analyzing nutrition and cardiovascular diseases will provide new clues regarding these mechanisms. However, omics integration is still in its infancy. Currently, some single-omics analyses have provided valuable data, mostly in the field of genomics. Thus, several gene-diet interactions in determining both intermediate (plasma lipids, etc.) and final cardiovascular phenotypes (stroke, myocardial infarction, etc.) have been reported. However, few studies have analyzed changes in gene expression and, moreover very few have focused on epigenomic or metabolomic biomarkers related to the MedDiet. Nevertheless, these preliminary results can help to better understand the inter-individual differences in cardiovascular risk and dietary response for further applications in personalized nutrition.