Circulating microRNAs (miRs) for diagnosing acute myocardial infarction: an exciting challenge

Elevated miRNA-499 Levels in Early Phase of Non-ST Elevation Acute Coronary Syndromes Predict Increased Long-Term Risk of Major Adverse Cardiac Events

Background/Objectives: Available data suggest the diagnostic potential of testing microRNAs (miRs) in myocardial infarction, but their prognostic value remains unclear. To evaluate the prognostic value of circulating miRs (miR-1, miR-21, miR-133a, miR-208 and miR-499) for predicting major adverse cardiac events (MACEs), including death, non-fatal myocardial infarction (MI) or cardiovascular rehospitalization, in patients with non-ST segment elevation acute coronary syndromes (NSTE-ACS). Methods: Our prospective, single-center, observational study included patients (pts) with NSTE-ACS admitted <24 h after symptoms onset and pts with confirmed stable coronary artery disease (SCAD) as controls. Relative expression of miRs was calculated, and subjects were categorized according to miRs expression on hospital admission into two groups (≤median and >median). Results: Overall, 103 NSTE-ACS (52 NSTEMI/51 UA) and 47 SCAD pts (median age 66 years, 67% male) were included. During the median 895 (581-1134) days of the follow-up, MACE occurred in 75 (50%) patients: 20 (13%) died, 28 (19%) presented with MI, and 65 (43%) were readmitted due to cardiovascular reasons. Incidence of MI, rehospitalization and MACE was significantly higher in pts with elevated (>median) miR-499 [MI: 34.3% vs. 7.3%; HR = 6.0 (2.8-12.7) for rehospitalization; 53.7% vs. 36.2%, HR = 2.3 (1.4-3.8) for MACE; 62.7% vs. 42%, HR = 2.4 (1.5-3.8)] for hospital readmission. In the Cox proportional hazards regression model, miR-499 expression above the median level [HR = 1.8 (1.1-3.1)], high-sensitivity cardiac troponin T [HR = 1.2 (1.02-1.5)], diabetes [HR = 1.7 (1.1-2.8)] and percutaneous intervention during hospital stay [HR = 2.1 (1.1-3.8)] were identified as independent predictors of MACE in long-term observation, even after adjustment for covariates. Conclusions: Elevated miR-499 level on hospital admission in NSTE-ACS is related to an increased rate of MACE in the 2.5-year follow-up.

miR‑146b‑5p inhibits tumorigenesis and metastasis of gallbladder cancer by targeting Toll‑like receptor 4 via the nuclear factor‑κB pathway

Gallbladder cancer (GBC) is a carcinoma of the biliary tract, which is common in developing countries and is associated with a high fatality rate. The aim of the present study was to investigate the mechanisms underlying the occurrence and development of GBC. A decrease in the expression of miR‑146b‑5p and an increase in the expression of its target gene Toll‑like receptor 4 (TLR4) were first observed in GBC tissues. Further study demonstrated that an increase in TLR4 expression caused by a decrease in miR‑146b‑5p expression led to activation of nuclear factor (NF)‑κB signaling. GBC cells were cultured in vitro, and it was observed that overexpression of miR‑146b‑5p effectively inhibited their viability, proliferation, migration and invasion, and increased their apoptosis. Using a BALB/c nude mouse xenograft model, it was demonstrated that overexpression of miR‑146b‑5p was sufficient to reduce tumor volume and alleviate pathological characteristics. Overall, the results of the present study indicated that the decrease in the expression of miR‑146b‑5p increased TLR4 expression and indirectly activated the NF‑κB signaling pathway, thereby regulating the development of GBC.

The Experimental Pathology at Ancona: 50 Years of Exciting and Pioneering Research on Human Pathology

Half century ago, a few academic pioneers founded the laboratories of experimental and ultrastructural pathology in Ancona. From this origin, a new phase of experimental studies developed aimed at translational and clinical research up to the present, when our group is internationally recognized for its fundamental contributions in gerontological research and molecular diagnostic pathology. Since the desire of immortality and of eternal youth seems to be as old as mankind, in the future we plan to focus our scientific research on Regenerative Medicine and Rejuvenation strategies. This is the most ambitious aim in the framework of the world aging population. We do not know whether we would achieve these results by ourselves. We are confident that, as in the past, new generations of scientist of the school of experimental pathology at Ancona will get the baton by the older one and lead the future with the same enthusiasm, love and commitment.

Epigenetic effects of physical activity in elderly patients with cardiovascular disease

Cardiovascular disease (CVD) is an important public health problem affecting especially the elderly. Over the past 20years, an increasing number of studies have examined its underlying pathophysiological mechanisms and new therapies are continually being discovered. However, despite considerable progress in CVD management, mortality and morbidity remain a major healthcare concern, and frequent hospital admissions compromise the daily life and social activities of these patients. Physical activity has emerged as an important non-pharmacological adjunctive therapy for CVD in older patients, especially for heart failure patients, exerting its beneficial effects on mortality, morbidity, and functional capacity. The mechanisms underlying the cardiovascular benefits of exercise are not wholly clear. Mounting evidence suggest that epigenetic modifications, such as DNA methylation, histone post-translational modifications (hPTMs) and non-coding RNA, especially microRNAs (miRNAs), may be induced by physical activity. Recently, a number of miRNAs have been identified as key players in gene expression modulation by exercise. MiRNAs are synthesized by living cells and actively released into the bloodstream through different shuttles. The epigenetic information, thus carried and delivered, is involved in the interplay between environmental factors, including physical activity, and individual genetic make-up. We review and discuss the effects of exercise on age-related CVDs, focusing on circulating miRNA (c-miRNAs) modulation. Epigenetic mechanisms may have clinical relevance in CVD prevention and management; since they can be modified, insights into the implications of lifestyle-related epigenetic changes in CVD etiology may help develop therapeutic protocols of exercise training that can be suitable and effective for elderly patients.

Noncoding RNAs as novel biomarkers in pancreatic cancer: what do we know?

Pancreatic cancer is an aggressive cancer of the digestive system, which is becoming a serious health problem worldwide. Overall survival for patients with pancreatic cancer is poor, mainly due to a lack of biomarkers to enable early diagnosis and a lack of prognostic markers that can inform decision-making, facilitating personalized treatment and an optimal clinical outcome. ncRNAs play an important role in pancreatic carcinogenesis. Here we review the literature on the role of ncRNAs as biomarkers in pancreatic cancer. We focus on the significance of ncRNAs as markers for early diagnosis, as prognostic biomarkers able to inform clinical management and as targets for novel therapeutics for patients with pancreatic cancer.

Expression of circulating miR-486 and miR-150 in patients with acute myocardial infarction

Background

With its high morbidity and mortality, acute myocardial infarction (AMI) places a major burden on society and on individual patients. Correct, early correct diagnosis is crucial to the management of AMI.

Methods

In this study, the expression of circulating miR-486 and miR-150 was investigated in AMI patients and the two miRNAs were evaluated as potential biomarkers for AMI. Plasma samples from 110 patients with AMI (65 patients with ST-segment elevation myocardial infarction (STEMI) and 45 patients with non-ST-segment elevation myocardial infarction (NSTEMI)) and 110 healthy adults were collected. Circulating levels of miR-486 and miR-150 were detected using quantitative real-time PCR in plasma samples.

Results

Results showed that the levels of miR-486 and miR-150 were significantly higher in AMI patients than in healthy controls. Receiver operating characteristic (ROC) curve analyses indicated that the two plasma miRNAs were of significant diagnostic value for AMI, especially NSTEMI. The combined ROC analysis revealed an AUC value of 0.771 in discriminating AMI patients from healthy controls and an AUC value of 0.845 in discriminating NSTEMI patients from healthy controls.

Conclusion

Results indicated that the levels of circulating miR-486 and miR-150 are associated with AMI. They may be novel and powerful biomarkers for AMI, especially for NSTEMI.

Clinical impact of circulating miR-26a, miR-191, and miR-208b in plasma of patients with acute myocardial infarction

Background

Aberrant expression of several types of miRNAs has been reported in acute myocardial infarction (AMI). The objective of our study was to compare miRNA expression in AMI patients and normal healthy people and determine whether miR-26a, miR-191, and miR-208b could be measured in plasma as indicators for AMI.

Methods

Detection of AMI patients and normal persons by using miRNA microarray chip analysis and miR-26a, miR-191, and miR-208b was screened out. Eighty-seven AMI patients and eighty-seven homogeneous healthy individuals were recruited. Total mRNA including miRNA was isolated and miR-26a, miR-191, and miR-208b expression were determined by qRT-PCR. Receiver operating characteristic curve analysis was performed to evaluate the instructive power of miR-26a, miR-191, and miR-208b for AMI. Dual-luciferase reporter assays indicated p21 is a direct target of miR-208b.

Results

miR-26a and miR-191 were low expressed in AMI compared with normal healthy people, but miR-208b was expressed at a high level in AMI. miR-26a showed an area under the curve (AUC) of 0.745, with a sensitivity of 73.6 % and a specificity of 72.4 %.The AUC for miR-191 was 0.669, with a sensitivity of 62.1 % and a specificity of 69.0 %.The AUC for miR-208b was 0.674, with a sensitivity of 59.8 % and a specificity of 73.6 %.

Conclusions

miR-208b was significantly increased in the AMI compared with healthy people, while miR-26a and miR-191 were decreased. miR-26a, miR-191, and miR-208b were potential indices of AMI, and miR-208b was more effective in patients with non-ST-elevation myocardial infarction.

MiR-34a, miR-21 and miR-23a as potential biomarkers for coronary artery disease: a pilot microarray study and confirmation in a 32 patient cohort

The aim of this study was to investigate the expression of circulating microRNAs (miRNAs) in apolipoprotein E (apoE) knockout mice (apoE(-/-)) and to validate the role of these miRNAs in human coronary artery disease (CAD). Pooled plasma from 10 apoE(-/-) mice and 10 healthy C57BL/6 (B6) mice was used to perform the microarray analysis. The results showed that miR-34a, miR-21, miR-23a, miR-30a and miR-106b were differentially expressed in apoE(-/-) mice, and these expression changes were confirmed by real-time quantitative reverse-transcription PCR. Then, miR-34a, miR-21, miR-23a, miR-30a and miR-106b were detected in the plasma of 32 patients with CAD and of 20 healthy controls. Only miR-34a, miR-21 and miR-23a were significantly differentially expressed in the plasma of CAD patients (all P<0.01). In conclusion, miR-34a, miR-21 and miR-23a were elevated in CAD patients, which means that these miRNAs might serve as biomarkers of CAD development and progression.

Diagnostic and prognostic value of circulating microRNAs in patients with acute chest pain

OBJECTIVES

To address the diagnostic value of circulating microRNAs (miRNAs) in patients presenting with acute chest pain.

DESIGN

In a prospective, international, multicentre study, six miRNAs (miR-133a, miR-208b, miR-223, miR-320a, miR-451 and miR-499) were simultaneously measured in a blinded fashion in 1155 unselected patients presenting with acute chest pain to the emergency department. The final diagnosis was adjudicated by two independent cardiologists. The clinical follow-up period was 2 years.

RESULTS

Acute myocardial infarction (AMI) was the adjudicated final diagnosis in 224 patients (19%). Levels of miR-208b, miR-499 and miR-320a were significantly higher in patients with AMI compared to those with other final diagnoses. MiR-208b provided the highest diagnostic accuracy for AMI (area under the receiver operating characteristic curve 0.76, 95% confidence interval 0.72-0.80). This diagnostic value was lower than that of the fourth-generation cardiac troponin T (cTnT; 0.84) or the high-sensitivity cTnT (hs-cTnT; 0.94; both P < 0.001 for comparison). None of the six miRNAs provided added diagnostic value when combined with cTnT or hs-cTnT (ns for the comparison of combinations vs. cTnT or hs-cTnT alone). During follow-up, 102 (9%) patients died. Levels of MiR-208b were higher in patients who died within 30 days, but the prognostic accuracy was low to moderate. None of the miRNAs predicted long-term mortality.

CONCLUSION

The miRNAs investigated in this study do not seem to provide incremental diagnostic or prognostic value in patients presenting with suspected AMI.

Clinical impact of circulating miR-133, miR-1291 and miR-663b in plasma of patients with acute myocardial infarction

Background

Acute myocardial infarction (AMI) is one of the leading causes for death in both developed and developing countries and it is the single largest cause of death in the United States, responsible for 1 out of every 6 deaths. The objective of this study was to determine microRNA (miRNA) expression in AMI and determine whether miR-133, miR-1291 and miR-663b could be measured in plasma as a biomarker for recurrence.

Methods

Patients with AMI and those without AMI were retrospectively recruited for a comparison of their plasma miR-133, miR-1291 and miR-663b expression.

Results

miR-133, miR-1291 and miR-663b levels were significantly overexpressed in AMI compared with Non-AMI. MiR-133 showed an AUC of 0.912, with a sensitivity of 81.1% and a specificity of 91.2%. The AUC for miR-1291 was 0.695, with a sensitivity of 78.4% and a specificity of 89.5%. The AUC for miR-663b was 0.611, with a sensitivity of 72.4% and a specificity of 76.5%.

Conclusions

This study demonstrated that the levels of miR-133, miR-1291 and miR-663b are associated with AMI. The potential of these miRNAs as biomarkers to improve patient stratification according to the risk of AMI and as circulating biomarkers for the AMI progonos warrants further study.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8183629061241474

MicroRNAs in Lipid Metabolism and Atherosclerosis

BACKGROUND: MicroRNAs (miRNA) are mediators of post-transcriptional gene expression that likely regulate most biological pathways and networks. The study of miRNAs is a rapidly emerging field; recent findings have revealed a significant role for miRNAs in atherosclerosis and lipoprotein metabolism.CONTENT: Results from recent studies demonstrated a role for miRNAs in endothelial integrity, macrophage inflammatory response to oxidized low-density lipoprotein, vascular smooth muscle cell proliferation and cholesterol synthesis. These mechanisms are all vital to the initiation and proliferation of atherosclerosis and cardiovascular disease. The importance of miRNAs has recently been recognized in cardiovascular sciences and miRNAs will likely become an integral part of our fundamental comprehension of atherosclerosis and lipoprotein metabolism. The extensive impact of miRNA mediated gene regulation and the relative ease of in vivo applicable modifications highlight the enormous potential of miRNA-based therapeutics in cardiovascular diseases.SUMMARY: miRNA studies in the field of lipid metabolism and atherosclerosis are in their infancy, and thus there is tremendous opportunity for discovery in this understudied area. The ability to target miRNAs in vivo through delivery of miRNA-mimics to enhance miRNA function, or antimiRNAs which inhibit miRNAs, has opened new avenues for the development of therapeutics for dyslipidemias and atherosclerosis, offers a unique approach to treating disease by modulating entire biological pathways. These exciting findings support the development of miRNA antagonists as potential therapeutics for the treatment of dyslipidaemia, atherosclerosis and related metabolic diseases.KEYWORDS: atherosclerosis, lipoprotein, HDL, miRNA

Stress-induced ECM alteration modulates cellular microRNAs that feedback to readjust the extracellular environment and cell behavior

The extracellular environment is a complex entity comprising of the extracellular matrix (ECM) and regulatory molecules. It is highly dynamic and under cell-extrinsic stress, transmits the stressed organism’s state to each individual ECM-connected cell. microRNAs (miRNAs) are regulatory molecules involved in virtually all the processes in the cell, especially under stress. In this review, we analyse how miRNA expression is regulated downstream of various signal transduction pathways induced by changes in the extracellular environment. In particular, we focus on the muscular dystrophy-associated cell adhesion molecule dystroglycan capable of signal transduction. Then we show how exactly the same miRNAs feedback to regulate the extracellular environment. The ultimate goal of this bi-directional signal transduction process is to change cell behavior under cell-extrinsic stress in order to respond to it accordingly.

MicroRNAs as biomarkers for ischemic heart disease

MicroRNAs (miRs) are short, noncoding RNAs that function as posttranscriptional inhibitors of mRNA translation to protein. They are essential for normal development and homeostasis. Dysregulated expression patterns both cause and result from disease states. Generally studied as intracellular mediators, miRs can be isolated from body fluids and exhibit remarkable stability to degradation. These features, in combination with their tissue specificity, make miRs attractive candidates as blood-derived biomarkers for coronary artery disease (CAD), the most frequent cause of death worldwide. The use of miRs as biomarkers in both symptomatic and asymptomatic CAD and the influence of conventional cardiovascular risk factors and CAD treatment on their circulating levels are the topics of this review. To conclude, it highlights the remaining hurdles to tackle before this promising application of miRs can enter into routine clinical practice.

Clinical implications of microRNAs in cancer

MicroRNAs (miRNAs) are endogenously produced non-coding RNAs that serve as micromanagers by negatively regulating gene expression. MiRNAs are implicated in several biological pathways including development of neoplasia. Because altered miRNA expression is implicated in the pathobiology of various cancers, these molecules serve as potential therapeutic targets. Using miRNA mimics to restore levels of aberrantly down-regulated miRNAs or miRNA inhibitors to inactivate over-expressed miRNAs shows promise as the next generation of therapeutic strategies. Manipulation of miRNAs offers an alternative therapeutic approach for chemo- and radiation-resistant tumors. Similarly, miRNA expression patterns can be used for diagnosis and to predict prognosis and efficacy of therapy. We present here an overview of how miRNAs affect cancers, how they may be used as biomarkers, and the clinical implications of miRNAs in cancer.

Extracellular communication via microRNA: lipid particles have a new message

The complexity of microRNA (miRNA)-mediated pathway control has burgeoned since the discovery that miRNAs are found in the extracellular space and constitute a form of cell-cell communication. miRNAs have been found in plasma, urine, and saliva and have recently been shown to be carried on lipoproteins. This has led to the proposal that circulating miRNAs may be useful biomarkers of various diseases, including cardiovascular disease, diabetes, and other forms of dysregulated metabolism. Although our understanding of the cellular machinery responsible for the secretion of miRNA is incomplete, it has been demonstrated that miRNAs are packaged into exosomes, microvesicles, and apoptotic bodies by a broad range of cell types. Intriguingly, a large portion of extracellular miRNA is found outside of any lipid-containing vesicle, and instead is associated with RNA binding proteins like argonautes 1 and 2, which may aid in their protection from abundant nucleases in the extracellular space. The excitement for miRNAs as biomarkers is mounting as more and more evidence supports that these noncoding RNAs are actively secreted from diseased tissues, possibly before the onset of overt disease. While caution should be taken in these early days, there is little doubt that extracellular miRNAs will hold tremendous potential as both diagnostic and therapeutic agents.