Plasma miR-208 as a biomarker of myocardial injury

miR-208a as a Biomarker of Isoproterenol-induced Cardiac Injury in Sod2+/− and C57BL/6J Wild-type Mice

This investigation examined microRNA-208a (miR-208a) as a potential biomarker of isoproterenol (ISO)-induced cardiac injury in superoxide dismutase-2 ( Sod2+/−) and the wild-type mice, and the potential sensitivity of Sod2+/− mice to ISO-induced toxicity. A single intraperitoneal injection of ISO was administered to age-matched wild-type and Sod2+/− mice at 0, 80, or 160 mg/kg. Plasma miR-208a, cardiac troponin I (cTnI), and ISO systemic exposure were measured at various time points postdose. Hearts were collected for histopathology examination and for tissue expression of miR-208a and myosin heavy chain 7. ISO administration caused increases in cTnI and miR-208a plasma levels that correlated with myocardial damage; however, the magnitude of increase differed according to the types of mice. At similar ISO systemic exposure, the magnitude of cTnI was greater in wild-type mice compared to Sod2+/− mice; however, the magnitude of miR-208a was greater in Sod2+/− mice than that of the wild-type mice. Myocardial degeneration occurred at ≥3 hr in the wild-type and ≥6 hr in Sod2+/− mice. At ≥24 hr after ISO administration, miR-208a appeared superior to cTnI in indicating myocardial injury in both wild-type and Sod2+/− mice. Sod2+/− mice were not more sensitive than wild-type mice to ISO-induced toxicity.

Role of exosomes in myocardial remodeling

Exosomes are nanovesicles released from cells through exocytosis and are known to be mediators of proximal as well as distant cell-to-cell signaling. They are surrounded by a classical bilayered membrane with an exceptionally high cholesterol/phospholipid ratio. Exosomes were first described in 1977, then named prostasomes, and in 1987 the name exosome was coined. Exosomes contain surface proteins, some of which can act as labels in order to find their target cells. Exosomes also contain messages in the form of proteins and nucleic acids (RNA and DNA) that are transferable to target cells. Little is known and written about cardiac exosomes, although Gupta and Knowlton described exosomes containing HSP60 in 2007. It is now known that exosomes from cardiomyocytes can transfect other cells and that the metabolic milieu of the parental cell decides the quality of exosomes released such that they induce differential gene expression in transfected cells. Future clinical use of exosomes in diagnosis, monitoring disease progress, and treatment is promising.

MiR-216a and miR-216b as markers for acute phased pancreatic injury

MicroRNAs (miRNAs) are endogenous small RNAs (length, 18-ss23 nucleotides) that regulate gene expression. Recently, plasma miRNAs have been investigated as biomarkers for various diseases. In the present study, we explored cell- or tissue-specific miRNAs and assessed the applicability of miRNA profiling for identifying biomarkers of tissue injuries. miRNA analyses in various human and rat tissues identified several candidate miRNAs with possible tissue-specific expression, some of which have already been reported. In the present study, we focused on pancreas-specific miRNAs, miR-216a and miR-216b. Laser microdissection revealed that miR-216a and 216b were predominantly expressed in acinar cells of the pancreas as compared to Langerhans' islet. Plasma concentrations of miR-216a and miR-216b considerably increased in a rat model of L-arginineinduced acute pancreatitis. The current results have confirmed that miRNA expression profiling in various cells is useful for providing biomarkers for cell- or tissue-specific injuries.

microRNAs as a new mechanism regulating adipose tissue inflammation in obesity and as a novel therapeutic strategy in the metabolic syndrome

Obesity is associated closely with the metabolic syndrome (MS). It is well known that obesity-induced chronic inflammation plays a fundamental role in the pathogenesis of MS. White adipose tissue (AT) is the primary site for the initiation and exacerbation of obesity-associated inflammation. Exploring the mechanisms of white AT inflammation and resetting the immunological balance in white AT could be crucial for the management of MS. Several prominent molecular mechanisms have been proposed to mediate inflammation in white AT, including hypoxia, endoplasmic reticulum stress, lipotoxicity, and metabolic endotoxemia. Recently, a growing body of evidence supports the role of miRNAs as a new important inflammatory mediator by regulating both the adaptive and innate immunity. This review will focus on the implication of miRNAs in white AT inflammation in obesity, and will also highlight the potential of miRNAs as targets for therapeutic intervention in MS as well as the challenges lying in miRNA-targeting therapeutics.

Stability of miRNA in human urine supports its biomarker potential

AIM

miRNAs are showing utility as biomarkers in urologic disease, however, a rigorous evaluation of their stability in urine is lacking. Here, we evaluate the stability of miRNAs in urine under clinically relevant storage procedures.

MATERIALS & METHODS

Eight healthy individuals provided clean catch urine samples that were stored at room temperature or at 4°C for 5 days, or subjected to ten freeze-thaw cycles at -80°C. For each condition, two miRNAs, miR-16 and miR-21, were quantitated by quantitative real-time PCR.

RESULTS

All conditions demonstrated a surprising degree of stability of miRNAs in the urine: by the end of ten freeze-thaw cycles, 23-37% of the initial amount remained; over the 5-day period of storage at room temperature, 35% of the initial amount remained; and at 4°C, 42-56% of the initial amount remained. Both miRNAs also showed degradation at approximately the same rate.

CONCLUSION

miRNAs are relatively stable in urine under a variety of storage conditions, which supports their utility as urinary biomarkers.

Diagnosis, prognosis and therapeutic role of circulating miRNAs in cardiovascular diseases

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in the world. Although much progress has been made for cardiovascular diseases in diagnosis, treatment and prognosis during the past two decades, the clinical need for a novel diagnostic biomarker and new therapeutic interventions to decrease the cardiovascular disease incidence is ongoing. MicroRNAs (miRNAs) are endogenous, small (∼22 nucleotides), single-stranded, non-coding RNAs that regulate gene expression and are detectable in whole blood, serum, plasma, urine and other body fluids in a highly stable form. Accumulating evidence suggests that miRNAs are potential novel biomarkers with high sensitivity for early diagnosis and modern treatment for cardiovascular diseases. Altered circulating miRNAs expressions have been reported in acute myocardial infarction (AMI), acute coronary syndrome (ACS), stable coronary artery disease, heart failure, atherosclerosis, essential hypertension and stroke. In the present review, we examine more recent data regarding circulating miRNAs and their potential roles in diagnosis, prognosis and therapeutic strategies for cardiovascular diseases. In addition, we briefly present our own recent experience in detecting circulating miRNAs, and the significance of these miRNAs in AMI prognosis.

Assessment of circulating microRNAs in plasma of lung cancer patients

Lung cancer is the most common cause of cancer deaths worldwide and numerous ongoing research efforts are directed to identify new strategies for its early detection. The development of non-invasive blood-based biomarkers for cancer detection in its preclinical phases is crucial to improve the outcome of this deadly disease. MicroRNAs (miRNAs) are a new promising class of circulating biomarkers for cancer detection and prognosis definition, but lack of consensus on data normalization methods for circulating miRNAs and the critical issue of haemolysis, has affected the identification of circulating miRNAs with diagnostic potential. We describe here an interesting approach for profiling circulating miRNAs in plasma samples based on the evaluation of reciprocal miRNA levels measured by quantitative Real-Time PCR. By monitoring changes of plasma miRNA-ratios, it is possible to assess the deregulation of tumor-related miRNAs and identify signatures with diagnostic and prognostic value. In addition, to avoid bias due to the release of miRNAs from blood cells, a miRNA-ratios signature distinguishing haemolyzed samples was identified. The method described was validated in plasma samples of lung cancer patients, but given its reproducibility and reliability, could be potentially applied for the identification of diagnostic circulating miRNAs in other diseases.

Upregulation of the long non-coding RNA PlncRNA-1 promotes esophageal squamous carcinoma cell proliferation and correlates with advanced clinical stage

BACKGROUND

Recent studies revealed that long noncoding RNAs (lncRNAs) play critical regulatory roles in cancer biology. PlncRNA-1 is one of lncRNAs that is associated with cell apoptosis and proliferation of prostate cancer.

AIM

This study aimed to assess the potential role of PlncRNA-1 in the pathogenesis of esophageal squamous cell carcinoma (ESCC).

MATERIALS AND METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression level of PlncRNA-1 in 73 pairs of ESCC and their matched normal tissues. The correlation of PlncRNA-1 with clinicopathological features and clinical stages was also analyzed. Cancer cell proliferation and apoptosis were assessed following knock-down of PlncRNA-1 by MTT, colony formation assay, and flow cytometry.

RESULTS

The expression of PlncRNA-1 was significantly higher in human ESCC compared with the adjacent noncancerous tissues (69.8 %, p < 0.05), and the high level of PlncRNA-1 expression was significantly correlated with advanced clinical stage (p < 0.01) and lymph node metastasis (p < 0.05). Furthermore, knockdown of PlncRNA-1 reduced cell proliferation and increased the apoptosis in vitro.

CONCLUSIONS

PlncRNA-1 plays an important role in ESCC cell proliferation. Overexpression of PlncRNA-1 is correlated with advanced tumor stage and lymph node metastasis, and may serve as a potential prognostic marker and therapeutic target for ESCC.

Serum miRNAs for early diagnosis, efficacy assessment and prognostic evaluation in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors, with features of high malignancy, high mortality and poor prognosis. Most patients with HCC are diagnosed at late stages. One main reason is the lack of highly sensitive and specific molecular markers. MicroRNAs (miRNA) are a kind of small non-coding RNAs involved in posttranscriptional regulation in eukaryotes. They participate in many developmental and physiological processes, including growth, cell differentiation, proliferation and apoptosis. Since abnormal expression of miRNAs is closely related to HCC, serum miRNAs have appreciable value in early diagnosis, efficacy assessment and prognostic evaluation in HCC.

microRNAs in cardiovascular diseases: current knowledge and the road ahead

Over the last few years, the field of microribonucleic acid (miRNA) in cardiovascular biology and disease has expanded at an incredible pace. miRNAs are themselves part of a larger family, that of non-coding RNAs, the importance of which for biological processes is starting to emerge. miRNAs are ~22-nucleotide-long RNA sequences that can legate messenger (m)RNAs at partially complementary binding sites, and hence regulate the rate of protein synthesis by altering the stability of the targeted mRNAs. In the cardiovascular system, miRNAs have been shown to be critical regulators of development and physiology. They control basic functions in virtually all cell types relevant to the cardiovascular system (such as endothelial cells, cardiac muscle, smooth muscle, inflammatory cells, and fibroblasts) and, thus, are directly involved in the pathophysiology of many cardiovascular diseases. As a result of their role in disease, they are being studied for exploitation in diagnostics, prognostics, and therapeutics. However, there are still significant obstacles that need to be overcome before they enter the clinical arena. We present here a review of the literature and outline the directions toward their use in the clinic.

Screening plasma miRNAs as biomarkers for renal ischemia-reperfusion injury in rats

Background

Acute kidney injury is a common clinical comorbidity and early diagnosis is crucial for improving prognosis, but there is still no ideal biomarker for early diagnosis.

Material/Methods

miRNA microarray was used for detecting miRNA in kidney subjected to renal ischemia-reperfusion injury 12 h after reperfusion. Real-time PCR was performed to validate the results of microarray. miRNAs in the ischemia group were twice as high as in the sham group. Kidney-enriched miR-10a, miR-192, and miR-194 were detected in rat plasma to screen potential biomarkers for renal ischemia-reperfusion injury. Aberrant expressed miRNA in plasma at 12 h were further detected at 1 h, 2 h, 6 h, 12 h, and 24 h to observe the changing trend of these miRNAs and were compared to blood urea nitrogen and serum creatinine.

Results

Thirty-six miRNAs were aberrantly expressed in kidney of rats with renal ischemia-reperfusion injury, among which 15 miRNAs had a 2-fold greater change. Results of real-time PCR were generally in accordance with microarray results. Levels of the 15 miRNAs differentially expressed in injured kidney were not significantly different from those in sham kidney. However, miR-10a, miR-192, and miR-194 were significantly increased in plasma of rats with renal ischemia-reperfusion injury, among which miR-10a was elevated within 1 h after reperfusion, whereas miR-192 and miR-194 were elevated at 6 h after injury. Blood urea nitrogen was increased at 12 h and serum creatinine was increased at 6 h after injury.

Conclusions

Plasma miR-10a, miR-192, and miR-194 were potential biomarkers for renal ischemia reperfusion injury in rats, and miR-10a might be the most promising plasma biomarker for renal injury because of its elevation within 1 h after renal injury, as well as renal specificity.

Cardiovascular microRNAs: as modulators and diagnostic biomarkers of diabetic heart disease

Diabetic heart disease (DHD) is the leading cause of morbidity and mortality among the people with diabetes, with approximately 80% of the deaths in diabetics are due to cardiovascular complications. Importantly, heart disease in the diabetics develop at a much earlier stage, although remaining asymptomatic till the later stage of the disease, thereby restricting its early detection and active therapeutic management. Thus, a better understanding of the modulators involved in the pathophysiology of DHD is necessary for the early diagnosis and development of novel therapeutic implications for diabetes-associated cardiovascular complications. microRNAs (miRs) have recently been evolved as key players in the various cardiovascular events through the regulation of cardiac gene expression. Besides their credible involvement in controlling the cellular processes, they are also released in to the circulation in disease states where they serve as potential diagnostic biomarkers for cardiovascular disease. However, their potential role in DHD as modulators as well as diagnostic biomarkers is largely unexplored. In this review, we describe the putative mechanisms of the selected cardiovascular miRs in relation to cardiovascular diseases and discuss their possible involvement in the pathophysiology and early diagnosis of DHD.

Dysregulated miR1254 and miR579 for cardiotoxicity in patients treated with bevacizumab in colorectal cancer

Methods for detecting circulating microRNAs (miRNAs), small RNAs that control gene expression, at high sensitivity and specificity in the blood have been reported in recent studies. The goal of this study was to determine if detectable levels of specific miRNAs are released into the circulation for bevacizumab-induced cardiotoxicity. A miRNA array analysis was performed using RNA isolated from 10 control patients in bevacizumab treatment, and n=10 patients have been confirmed to have bevacizumab-induced cardiotoxicity. From the array, we selected 19 candidate miRNA for a second validation study in 90 controls and 88 patients with bevacizumab-induced cardiotoxicity. Consistent with the data obtained from the microRNA array, circulating levels of five miRNAs were significantly increased in patients with bevacizumab-induced cardiotoxicity compared with controls. To confirm these data, we compared selected miRNAs in the plasma of patients with bevacizumab-induced cardiotoxicity with those of 66 patients with acute myocardial infarction (AMI). Moreover, we went on to analyze what factors may influence the levels of potential biomarker miRNAs. Consistent with the data obtained from the microRNA array, circulating levels of five miRNAs were significantly increased in patients with bevacizumab-induced cardiotoxicity compared with those of healthy bevacizumab treatment controls. However, only miRNA1254 and miRNA579 showed high specificity in the validation experiments. Moreover, we went on to analyze what factors may influence the levels of potential biomarker miRNAs. We identify two miRNAs that are specifically elevated in patients with bevacizumab-induced cardiotoxicity, miR1254 and miRNA579, and miRNA1254 shows the strongest correlation to the clinical diagnosis of bevacizumab-induced cardiotoxicity.

Tumor-associated circulating microRNAs as biomarkers of cancer

MicroRNAs (miRNAs), the 17- to 25-nucleotide long noncoding RNAs that modulate the expression of mRNAs and proteins, have emerged as critical players in cancer initiation and progression processes. Deregulation of tissue miRNA expression levels associated with specific genetic alterations has been demonstrated in cancer, where miRNAs function either as oncogenes or as tumor-suppressor genes and are shed from cancer cells into circulation. The present review summarizes and evaluates recent advances in our understanding of the characteristics of tumor tissue miRNAs, circulating miRNAs, and the stability of miRNAs in tissues and their varying expression profiles in circulating tumor cells, and body fluids including blood plasma. These advances in knowledge have led to intense efforts towards discovery and validation of differentially expressing tumor-associated miRNAs as biomarkers and therapeutic targets of cancer. The development of tumor-specific miRNA signatures as cancer biomarkers detectable in malignant cells and body fluids should help with early detection and more effective therapeutic intervention for individual patients.

The therapeutic potential of miRNAs regulated in settings of physiological cardiac hypertrophy

Cardiac hypertrophy is broadly defined as an increase in heart mass. Heart enlargement in a setting of cardiac disease is referred to as pathological hypertrophy and often progresses to heart failure. Physiological hypertrophy refers to heart growth in response to postnatal development, exercise training and pregnancy, and is an adaptive response associated with the activation of cardioprotective signaling cascades. miRNAs have emerged as novel therapeutic targets for numerous pathologies, and miRNA-based therapies have already entered clinical trials. The identification of miRNAs differentially regulated during physiological growth may open up new therapeutic approaches for heart failure. In this review, we present information on miRNAs regulated in models of physiological hypertrophy, describe preclinical cardiac disease studies that have successfully targeted miRNAs regulated in settings of physiological growth (miR-34, miR-15, miR-199b, miR-208a and miR-378), and discuss challenges to overcome for the safe entry of miRNA-based therapies into the clinic for heart failure patients.

Molecular basis of cancer-therapy-induced cardiotoxicity: introducing microRNA biomarkers for early assessment of subclinical myocardial injury

Development of reliable biomarkers for early clinical assessment of drug-induced cardiotoxicity could allow the detection of subclinical cardiac injury risk in vulnerable patients before irreversible damage occurs. Currently, it is difficult to predict who will develop drug-induced cardiotoxicity owing to lack of sensitivity and/or specificity of currently used diagnostics. miRNAs are mRNA regulators and they are currently being extensively profiled for use as biomarkers due to their specific tissue and disease expression signature profiles. Identification of cardiotoxicity-specific miRNA biomarkers could provide clinicians with a valuable tool to allow prognosis of patients at risk of cardiovascular injury, alteration of a treatment regime or the introduction of an adjunct therapy in order to increase the long-term survival rate of patients treated with cardiotoxic drugs.

Rapid upregulation and clearance of distinct circulating microRNAs after prolonged aerobic exercise

Short nonprotein coding RNA molecules, known as microRNAs (miRNAs), are intracellular mediators of adaptive processes, including muscle hypertrophy, contractile force generation, and inflammation. During basal conditions and tissue injury, miRNAs are released into the bloodstream as "circulating" miRNAs (c-miRNAs). To date, the impact of extended-duration, submaximal aerobic exercise on plasma concentrations of c-miRNAs remains incompletely characterized. We hypothesized that specific c-miRNAs are differentially upregulated following prolonged aerobic exercise. To test this hypothesis, we measured concentrations of c-miRNAs enriched in muscle (miR-1, miR-133a, miR-499-5p), cardiac tissue (miR-208a), and the vascular endothelium (miR-126), as well as those important in inflammation (miR-146a) in healthy male marathon runners (N = 21) at rest, immediately after a marathon (42-km foot race), and 24 h after the race. In addition, we compared c-miRNA profiles to those of conventional protein biomarkers reflective of skeletal muscle damage, cardiac stress and necrosis, and systemic inflammation. Candidate c-miRNAs increased immediately after the marathon and declined to prerace levels or lower after 24 h of race completion. However, the magnitude of change for each c-miRNA differed, even when originating from the same tissue type. In contrast, traditional biomarkers increased after exercise but remained elevated 24 h postexercise. Thus c-miRNAs respond differentially to prolonged exercise, suggesting the existence of specific mechanisms of c-miRNA release and clearance not fully explained by generalized cellular injury. Furthermore, c-miRNA expression patterns differ in a temporal fashion from corollary conventional tissue-specific biomarkers, emphasizing the potential of c-miRNAs as unique, real-time markers of exercise-induced tissue adaptation.

Regulation of UCP1 in the Browning of Epididymal Adipose Tissue by β3-Adrenergic Agonist: A Role for MicroRNAs

Background. White adipose tissue browning may be a promising strategy to combat obesity. UCP1 is strongly induced in White adipose tissue with β3-adrenergic agonist treatment, but the causes of this increase have not been fully elucidated. This study aims to explore more miRNAs involved in the process of browning of visceral adipose tissue. Methods. Total of fourteen mice were randomly divided into control and study group. Study group mice were injected intraperitoneally with CL316243 once daily for seven days; meanwhile the control group were treated with 0.9% NaCl. After a 7-day period, the expression of genes involved in WAT browning and potential UCP1-targeting miRNAs in adipose tissues was analyzed by qPCR. Results. qPCR analysis revealed that UCP1, DIO2, CIDEA, and CPT1B in epididymal adipose tissue were overexpressed in CL316243 group. Furthermore, potential UCP1-targeting miR-9 and miR-338-3p in epididymal adipose tissue were significantly decreased in CL316243 group. Conclusion. This suggests that potential UCP1-targeting miR-9 and miR-338-3p may be involved in the browning of epididymal adipose tissue by regulating UCP1 gene expression. In this study, we demonstrated that this increase of UCP1 is due, at least in part, to the decreased expression of certain UCP1-targeting miRNAs in epididymal adipose tissue compared to control.

Stability of miR-126 in Urine and Its Potential as a Biomarker for Renal Endothelial Injury with Diabetic Nephropathy

Background. The purpose of the present study was to assess the feasibility of using miR-126 in the urine as a biomarker for diabetic nephropathy. Methods. miRNAs were extracted from the urine samples of T2DM patients with diabetic nephropathy (DN; n = 92), T2DM without DN (n = 86), and 85 healthy volunteers using quantitative reverse transcriptase polymerase chain reaction (real-time polymerase chain reaction) analysis. Stability of urinary miR-126 and factors that affected the stability were assessed. A subgroup analysis was also carried out to compare the urinary miR-126 level in T2DM patients well controlled by the treatment versus those who were not well controlled. Results. Urinary miR-126 was stable when the urine samples were kept at room temperature for extended period of time, 4°C, -20°C, and -80°C for up to 12 hours or subjected to 10 freeze-and-thaw cycle. Urinary miR-126 was significantly higher in T2DM patients with DN (5.76 ± 0.33 versus 3.25 ± 0.45 in T2DM patients without DN). Successful treatment significantly reduced urinary miR-126 in T2DM patients with DN to 3.89 ± 0.52 (P < 0.05). Conclusion. miR-126 in the urine is stable and it could be used as a biomarker of DN and to monitor the treatment response.

Assessment of operability of patients with pulmonary arterial hypertension associated with congenital heart disease

Pulmonary arterial hypertension (PAH) is a common complication of congenital heart disease, and is now predominantly among patients with uncorrected left-to-right shunts. A growing population is characterized by persistent or recurrent PAH after surgical or interventional correction of left-to-right shunts; the latter having a worse prognosis than other forms of PAH associated with congenital heart disease. New treatments for PAH have been shown to be effective in improving PAH exercise capacity and hemodynamics, raising the hope for making previously inoperable congenital heart defects operable and shifting the framework for the assessment of operability. This review focuses on current methods for assessing operability in PAH associated with congenital heart disease, and the possibility of "treat-and-repair" vs. "repair-and-treat" strategies for patients with inoperable or borderline PAH.

Circulating microRNAs as mirrors of acute coronary syndromes: MiRacle or quagMire?

Acute coronary syndrome (ACS), a leading cause of morbidity and mortality worldwide, is among the most serious cardiovascular diseases. Exploring novel approaches, which can complement and improve current strategies for ACS, is continuous. MicroRNAs (miRNAs) are a novel class of small, short non-coding RNA that post-transcriptionally regulate genes. The tissue- or cell-specific distribution features of miRNAs and its merit of stably existing in serum and plasma make them attractive biomarkers for ACS. An early and accurate diagnosis is the pre-requisite to facilitate rapid decision making and treatment and therefore improve outcome in ACS patients. This review highlights and summarizes recent studies using circulating miRNAs as novel biomarkers for ACS including its role in diagnosis, prediction, prognosis and reaction to therapy. In addition, we also discuss the potential function of miRNAs as extracellular communicators in cell-to-cell communication. Large multicentre studies are highly needed to pave the road for using circulating miRNAs as biomarkers for ACS from the bench to the bedside. Considering the advantageous properties and the continuously increasing number of studies, circulating miRNAs definitely have the potential to be reasonable diagnostic tools once their infancy has passed.

Circulating microRNAs: a potential role in diagnosis and prognosis of acute myocardial infarction

Rapid and correct diagnosis of acute myocardial infarction (AMI) plays a crucial role in saving patients' life. Although some biomarkers (such as cardiac troponin and creatine kinase) are available for AMI diagnosis so far, there is still a clinical need for novel biomarkers, which can reliably rule in or rule out AMI immediately on admission. Circulating microRNAs (miRNAs) are a potential choice for novel biomarkers in AMI diagnosis and prognosis with high sensitivity and specificity. Circulating microRNAs are endogenous miRNAs that are detectable in whole blood, serum, or plasma in a highly stable form. Until now, around 20 circulating miRNAs were reported to be closely associated with AMI. In this minireview, we summarized recent available data on the correlation between circulating miRNAs and AMI. Some miRNAs, such as miR-208, miR-499, miR-133, and miR-1, were given special attention, since they may have a potential prospect in diagnosis and prognosis of AMI.

Human miRNome profiling identifies microRNAs differentially present in the urine after kidney injury

BACKGROUND

Extracellular microRNAs (miRNAs) have been proposed as potentially robust and stable biomarkers of various disease conditions. The primary objective of this study was to identify miRNAs differentially occurring in the urine that could serve as potential biomarkers of acute kidney injury (AKI), because traditional AKI markers have limitations with respect to sensitivity, specificity, and timeliness of diagnosis.

METHODS

We profiled 1809 miRNAs in pooled urine samples from 6 patients with AKI and from 6 healthy controls. We measured the 378 stably detectable miRNAs in the 12 samples individually and selected the top 7 miRNAs that were most different in the urine of patients with AKI compared with the non-AKI control individuals. These miRNAs were assessed in a larger cohort of patients with AKI (n = 98: 71 AKI patients in the intensive care unit (ICU) and 27 kidney transplantation patients with biopsy-proven tubular injury) and patients without AKI (n = 97: 74 healthy volunteers and 23 ICU patients without AKI).

RESULTS

We identified 4 miRNAs capable of significantly differentiating patients with AKI from individuals without AKI: miR-21 (P = 0.0005), miR-200c (P < 0.0001), miR-423 (P = 0.001), and miR-4640 (P = 0.0355). The combined cross-validated area under the ROC curve for these 4 miRNAs was 0.91. The imprecision with respect to miRNA isolation and reverse transcription efficiency was <9% across 224 samples.

CONCLUSIONS

In this study we determined the entire miRNome of human urine and identified a panel of miRNAs that are both detectable noninvasively and diagnostically sensitive indicators of kidney damage.

Circulating microRNA-101 as a potential biomarker for hepatitis B virus-related hepatocellular carcinoma

Circulating microRNAs (miRNAs) are emerging as promising biomarkers for cancer; however, the significance of circulating miRNAs in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) remains largely unknown. Based on our prior observations that miRNA-101 (miR-101) is downregulated by HBV and induces epigenetic modification, we sought to test whether circulating miR-101 may serve as a potential biomarker for HCC. The expression of miR-101 in HCCs and serum was evaluated by real-time polymerase chain reaction. Tissue and serum miR-101 levels were assessed in samples from patients with HBV-related HCC and healthy controls. A potential correlation was also evaluated between miR-101 expression and the clinicopathological features and prognosis of HCC patients. miR-101 was downregulated in HBV-related HCC tissues compared with adjacent noncancerous tissues. Furthermore, the miR-101 levels in these tissues from HCC patients were significantly lower than those in tissues from control subjects. Notably, serum miR-101 levels were found to have an inverse correlation with tissue miR-101 expression levels. The expression of serum miR-101 in patients with HBV-related HCC was significantly higher than that in the healthy controls, and this increase correlated with hepatitis B surface antigen positivity, HBV DNA levels and tumor size. These results indicate that different factors govern the levels of miR-101 in the tissue and serum of HCC patients. Given the marked and consistent increase in serum miR-101 levels in HCC patients, circulating miR-101 may serve as a promising biochemical marker for monitoring the progression of tumor development in HBV-related HCC.

Host serum miR-223 is a potential new biomarker for Schistosoma japonicum infection and the response to chemotherapy

BACKGROUND

Numerous studies have shown that aberrant microRNA (miRNA) expression is associated with the pathogenesis and progression of various human diseases. Hence, serum miRNAs are considered to be potential biomarkers for the diagnosis of human diseases. This study examined whether several miRNAs known to be commonly deregulated in liver diseases are deregulated in the serum of hosts with hepatic schistosomiasis, and thus whether they could serve as potential markers for detection of schistosome infection and evaluation of the effectiveness of chemotherapy.

METHODS

We analyzed the serum levels of six selected candidate miRNA molecules (miR-146b, miR-122, miR-223, miR-199a-5p, miR-199a-3p, miR-34a) from mice, rabbits, buffalos and humans infected with Schistosoma japonicum using qPCR. We evaluated liver pathology by determining the hydroxyproline content in liver tissues. Primary resident liver cells were isolated to quantify the expression level of deregulated miRNAs. Bioinformatics analyses were also conducted to assess the potential function of miR-223.

RESULTS

Using a mouse model of Schistosoma japonicum infection, we found that the expression level of serum miR-223 was significantly elevated after infection, but returned to near normal levels after the treatment with praziquantel (PZQ). Importantly, the level of serum miR-223 reflected the extent of liver pathology post-infection. We validated the elevated level of the circulating miR-223 in serum samples of other host species including rabbits, buffalos and humans. In addition, our results showed that miR-223 was primarily located in the Kupffer cells, but its expression levels were significantly up-regulated in hepatocytes, hepatic stellate cells and Kupffer cells after infection. Bioinformatics analyses revealed a potential functional role of miR-223 in transcription regulator activity, transcription factor activity and DNA binding.

CONCLUSIONS

This study suggested that the circulating miR-223 could serve as a potential new biomarker for the detection of schistosome infection and the assessment of the response to chemotherapy.

Plasma microRNA signature as a noninvasive biomarker for acute graft-versus-host disease

Acute graft-versus-host disease (aGVHD) is the leading cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). Approximately 35% to 50% of HCT recipients develop aGVHD; however, there are no validated diagnostic and predictive blood biomarkers for aGVHD in clinical use. Here, we show that plasma samples from aGVHD patients have a distinct microRNA (miRNA) expression profile. We found that 6 miRNAs (miR-423, miR-199a-3p, miR-93*, miR-377, miR-155, and miR-30a) were significantly upregulated in the plasma of aGVHD patients (n = 116) when compared with non-GVHD patients (n = 52) in training and validation phases. We have developed a model including 4 miRNAs (miR-423, miR-199a-3p, miR-93*, and miR-377) that can predict the probability of aGVHD with an area under the curve of 0.80. Moreover, these elevated miRNAs were detected before the onset of aGVHD (median = 16 days before diagnosis). In addition, the levels of these miRNAs were positively associated with aGVHD severity, and high expression of the miRNA panel was associated with poor overall survival. Furthermore, the miRNA signature for aGVHD was not detected in the plasma of lung transplant or nontransplant sepsis patients. Our results have identified a specific plasma miRNA signature that may serve as an independent biomarker for the prediction, diagnosis, and prognosis of aGVHD.

Circulating MicroRNAs as potential biomarkers for alcoholic steatohepatitis

AIMS

To investigate serum miRNA profile in alcoholic steatohepatitis (ASH), evaluate its effect as non-invasive diagnostic tool and to study its targets' function.

METHODS

Microarray and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were utilized to detect serum miRNAs pattern in a rat ASH model, followed by target prediction with bioinformatics calculation. The functions and pathways of miRNAs' targets were analysed using databases of Gene Ontology and KEGG. The association between dysregulated miRNAs and genes was assessed by MiR-Gene Network. Five top dysregulated miRNAs were also verified in humans.

RESULTS

Eight up-regulated and three down-regulated serum miRNAs were selected as an accurate molecular signature in distinguishing ASH from control. For up-regulated miRNAs, 122 GO and 144 KEGG pathways were significantly enriched, including apoptosis, lipid metabolic process, PPAR signalling pathway. For down-regulated miRNAs, 86 GO and 104 KEGG pathways were enriched, including fatty acid metabolism and insulin signalling pathway. Besides, Ccdc117, Gcom1, Zmynd11 and Zfp423 were found at top list as under common regulation of maximum miRNAs. Moreover, miR-214 had the highest degree of 63 among all miRNAs, followed by miR-203 and miR-539. Similarly, Stat3 and Lyn showed the highest degree of 5 among all downstream targets. All significance analysis of microarrays (SAM) revealed that five top dysregulated miRNAs showed the same tendency in humans.

CONCLUSION

We have reported a unique serum miRNA pattern for non-invasive diagnosis of ASH and provided data reservoir for miRNA and downstream targets exploration.

Dynamic nature of noncoding RNA regulation of adaptive immune response

Immune response plays a fundamental role in protecting the organism from infections; however, dysregulation often occurs and can be detrimental for the organism, leading to a variety of immune-mediated diseases. Recently our understanding of the molecular and cellular networks regulating the immune response, and, in particular, adaptive immunity, has improved dramatically. For many years, much of the focus has been on the study of protein regulators; nevertheless, recent evidence points to a fundamental role for specific classes of noncoding RNAs (ncRNAs) in regulating development, activation and homeostasis of the immune system. Although microRNAs (miRNAs) are the most comprehensive and well-studied, a number of reports suggest the exciting possibility that long ncRNAs (lncRNAs) could mediate host response and immune function. Finally, evidence is also accumulating that suggests a role for miRNAs and other small ncRNAs in autocrine, paracrine and exocrine signaling events, thus highlighting an elaborate network of regulatory interactions mediated by different classes of ncRNAs during immune response. This review will explore the multifaceted roles of ncRNAs in the adaptive immune response. In particular, we will focus on the well-established role of miRNAs and on the emerging role of lncRNAs and circulating ncRNAs, which all make indispensable contributions to the understanding of the multilayered modulation of the adaptive immune response.

Serum miR-21 and miR-155 expression in idiopathic pulmonary fibrosis

OBJECTIVE

To investigate the expression of serum miRNA-21(miR-21) and miRNA-155 (miR-155) in idiopathic pulmonary fibrosis (IPF).

METHODS

A study including 65 patients with IPF and 65 similar age and gender healthy controls was performed. Serum specimens were collected from all subjects. Total RNA was extracted and the quantitative reverse transcription-polymerase chain reaction was used to measure serum miR-21 and miR-155 in both groups. Clinicopathologic features were assessed to determine associations with serum miR-21 and miR-155 concentrations.

RESULTS

Serum miR-21 expression was significantly higher in IPF samples than in healthy controls (p < 0.01), while serum miR-155 expression did not show a statistically significant difference (p > 0.05). Forced vital capacity (FVC) and radiologic features were associated with miR-21 and miR-155 expression in serum (p < 0.05). Neither miR-21 nor miR-155 expression was statistically significantly associated with clinicopathologic parameters, such as gender (p > 0.05) and age (p > 0.05).

CONCLUSION

These findings suggest that serum miR-21 is associated with IPF and the degree of damage indicated by FVC and radiologic examinations could correlate with miR-21 and miR-155 expression in serum. From another perspective, our study confirmed serum miRNA can be stable and detectable in serum of patients with IPF, which could prove useful as it could be considered as a new biomarker in serum for diagnosis and assessment of prognosis of IPF in the future.

Serum microRNA-122 kinetics in patients with chronic hepatitis C virus infection during antiviral therapy

The levels of the liver-specific microRNA-122 (miR-122) circulating extracellularly in the blood have been shown to be increased upon liver damage. However, it is unknown if the levels of serum miR-122 are altered during antiviral therapy and reflect the therapeutic success. Here, we investigated miR-122 serum levels in patients with chronic hepatitis C virus (HCV) genotype 1 infection during antiviral therapy with pegylated interferon and ribavirin. Therefore, sera from 60 patients with chronic HCV infection genotype 1 showing sustained virological response (SVR), non-response or relapse to therapy obtained at baseline, 4, 12, 24 weeks, end of treatment and follow-up were analysed retrospectively for miR-122 content by quantitative real-time reverse transcription PCR. The time courses of miR-122 were correlated with HCV RNA as well as standard liver parameters. We found that while there was no relation between serum miR-122 and HCV RNA levels at baseline, the decline in HCV RNA upon beginning of the therapy closely correlated with the reduction of serum miR-122 in the three different patient groups. Moreover, the serum miR-122 level correlated well with alanine aminotransaminase, a marker of ongoing liver damage. At follow-up serum miR-122 levels remained low in SVR, but increased to baseline levels in patients not responding or showing relapse to therapy. In contrast, the serum concentration of the ubiquitously expressed miR-16 did not change during therapy. We conclude that the serum level of miR-122 well reflects the success of interferon/ribavirin therapy in patients with chronic HCV infection.

A simple high-throughput technology enables gain-of-function screening of human microRNAs

MicroRNAs (miRs) regulate cellular processes by modulating gene expression. Although transcriptomic studies have identified numerous miRs differentially expressed in diseased versus normal cells, expression analysis alone cannot distinguish miRs driving a disease phenotype from those merely associated with the disease. To address this limitation, we developed miR-HTS, a method for unbiased high-throughput screening of the miRNome to identify functionally relevant miRs. Herein, we applied miR-HTS to simultaneously analyze the effects of 578 lentivirally transduced human miRs or miR clusters on growth of the IMR90 human lung fibroblast cell line. Growth-regulatory miRs were identified by quantitating the representation (i.e., relative abundance) of cells overexpressing each miR over a one-month culture of IMR90, using a panel of custom-designed quantitative real-time PCR (qPCR) assays specific for each transduced miR expression cassette. The miR-HTS identified 4 miRs previously reported to inhibit the growth of human lung-derived cell lines and 55 novel growth-inhibitory miR candidates. Nine of 12 (75%) selected candidate miRs were validated and shown to inhibit IMR90 cell growth. Thus, this novel lentiviral library- and qPCR-based miR-HTS technology provides a sensitive platform for functional screening that is straightforward and relatively inexpensive.

Development and application of a novel reverse transcription real-time PCR method for miR-499 quantification

OBJECTIVES

MicroRNAs (miRNAs) are endogenous small RNAs of 21-25 nucleotides that can pair with sites in 3' untranslated regions in mRNAs of protein-coding genes to downregulate their expression. Recently, miR-499 and other miRNAs released in circulating blood have been reported as promising biomarkers for acute myocardial infarction (AMI). In the present study, we developed a novel reverse-transcription real-time PCR assay for human miR-499 quantification.

DESIGN AND METHODS

miR-499 was reverse-transcribed with a 3' portion-specific primer into cDNAs. The cDNAs were further extended with overlap PCR. The extended cDNAs were determined by quantitative, real-time PCR. Synthetic miR-499 was put into the RT reaction over an optimal range to generate standard curves for absolute quantification of miR-499.

RESULTS

In the presence of 0.0001 amol/μL to 1.0×10⁶ amol/μL of synthetic miR-499, we observed a linear correlation (R²=0.999) between the logarithm of the amount of input RNA and the CT value. The miR-499 was reliably measured at a detection limit of 0.0001 amol/μL. The miR-499 measurements in spiked plasma samples indicated excellent correlation between the novel qRT PCR and classic stem loop qRT PCR. The qRT PCR analysis demonstrated that miR-499 was detected with higher levels in plasma from the patient with AMI in acute phase (AMI) compared with those from the control groups (P<0.001).

CONCLUSIONS

We developed a novel reverse-transcription real-time PCR assay for human miR-499 quantification. The good reproducibility and wide linearity range may permit more use of it in the quantification of other human miRNAs in future.

Circulating miRNAs reflect early myocardial injury and recovery after heart transplantation

BACKGROUND

MicroRNAs (miRNAs) are short, single-stranded and non-coding RNAs, freely circulating in human plasma and correlating with vary pathologies. In this study, we monitored early myocardial injury and recovery after heart transplantation by detecting levels of circulating muscle-specific miR-133a, miR-133b and miR-208a.

METHODS

7 consecutive patients underwent heart transplantation in Fuwai hospital and 14 healthy controls were included in our study. Peripheral vein blood was drawn from patients on the day just after transplantation (day 0), the 1st, 2nd, 3rd, 7th and 14th day after transplantation respectively. Serum from peripheral blood was obtained for cardiac troponin I (cTnI) measurement. Plasma was centrifuged from peripheral blood for measuring miR-133a, miR-133b and miR-208a by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The plasma concentration of miRNAs were calculated by absolute quantification method. The sensitivity and specificity of circulating miRNAs were revealed by receiver operating characteristic curve (ROC) analysis. Correlations between miRNAs and cTnI / perioperative parameters were analyzed.

RESULTS

Similar to cTnI, miR-133a, miR-133b and miR-208a all showed dynamic changes from high to low levels early after operation. The Sensitivity and specificity of miRNAs were: miR-133a (85.7%,100%), miR-208a (100%,100%), and miR-133b (90%,100%). Correlations between miRNAs and cTnI were statistically significant (p < 0.05), especially for miR-133b (R2 = 0.813, p < 0.001). MiR-133b from Day 0-Day 2 (r > 0.98, p < 0.01), and cTnI from Day 1- Day 3 (r > 0.86, p < 0.05) had strong correlations with bypass time, particularly parallel bypass time. Obviously, miR-133b had a better correlation than cTnI. Circulating miR-133b correlated well with parameters of heart function such as central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), cardiac output (CO) and inotrope support, while cTnI only correlated with 3 of the 4 parameters mentioned above. MiR-133b also had strong correlations with ventilation time (r > 0.99, p < 0.001) and length of ICU stay (r > 0.92, p < 0.05), both of which reflected the recovery after operation. The correlation coefficients of miR-133b were also higher than that of cTnI.

CONCLUSIONS

The dynamic change in circulating muscle-specific miRNAs, especially miR-133b can reflect early myocardial injury after heart transplantation. And miR-133b may have advantages over cTnI in forecasting graft dysfunction and recovery of patients after operation.

Hide and seek: tell-tale signs of breast cancer lurking in the blood

Breast cancer treatment is improving due to the introduction of new drugs, guided by molecular testing of the primary tumour for mutations/oncogenic drivers (e.g. HER2 gene amplification). However, tumour tissue is not always available for molecular analysis, intra-tumoural heterogeneity is common and the "cancer genome" is known to evolve with time, particularly following treatment as resistance develops. After resection, those patients with only residual micrometastases are likely to be cured but those with radiologically detectable overt disease are not. Thus, the discovery of blood test(s) that could (1) alert clinicians to early primary or recurrent disease and (2) monitor response to treatment could impact significantly on mortality. Towards this, we and others have focused on molecular profiling of circulating nucleic acids isolated from plasma, both cell-free DNA (cfDNA) and microRNAs, and the relationship of these to circulating tumour cells (CTCs). This review considers the utility of each as circulating biomarkers in breast cancer with particular emphasis on the bioinformatic tools available to support molecular profiling.

Circulating miRNAs as potential marker for pulmonary hypertension

MircoRNAs (miRNAs) are small non-coding RNAs that govern the gene expression and, play significant role in the pathogenesis of heart failure. The detection of miRNAs in circulation of pulmonary hypertensive (PH) human subjects remains elusive. In the current study, we determined the pattern of miRNAs of mild-to-severe human PH subjects and, compared them with the control subjects by miRNA array. Blood was obtained using fluoroscopic and waveform guided catheterization from the distal (pulmonary artery) port of the catheter. A total 40 human subjects were included in the study and, the degree of PH was determined by mean pulmonary arterial pressure. Among several miRNAs in the array, we validated 14 miRNAs and, the data were consistent with the array profile. We identified several novel downregulated miRNAs (miR-451, miR-1246) and upregulated miRNAs (miR-23b, miR-130a and miR-191) in the circulation of PH subjects. Our study showed novel set of miRNAs which are dysregulated in PH and, are directly proportional to the degree of PH. These miRNAs may be considered as potential biomarker for early detection of PH.

Serum miR-210 and miR-30a expressions tend to revert to fetal levels in Chinese adult patients with chronic heart failure

BACKGROUND

MicroRNAs (miRNAs) are widely involved in the process of chronic heart failure (HF), which is characterized by reactivation of the fetal gene program. Here, we examined whether the serum expression levels of some HF-related miRNAs in adult HF patients would tend to revert to fetal levels.

METHODS AND RESULTS

Serum was obtained from the peripheral venous blood of 22 HF patients, 18 asymptomatic controls, and the umbilical venous blood of 9 fetuses from 9 independent parturitions. Serum pools of the three groups were initially screened against 40 known HF-associated miRNAs via quantitative reverse transcriptase polymerase chain reaction. Twenty-seven miRNAs were stably expressed in the serum pools. Nine miRNAs showed similar expression levels in the HF and fetus groups compared to the controls, two of which (miR-210, miR-30a) were significantly up-regulated in both groups. These miRNAs showed high diagnostic accuracy and correlations with blood N-terminal prohormone of brain natriuretic peptide, identifying them as potential biomarkers for HF. Putative targets of the miRNAs were predicted with online software programs, and the Kyoto Encyclopedia of Genes and Genomes pathway analysis was employed to identify miRNA-regulated functional modules. In particular, miR-210 seemed to be more closely related than miR-30a to the pathological mechanisms of HF, including the calcium signaling, vascular smooth muscle contraction, transforming growth factor-β signaling, and aldosterone-regulated sodium reabsorption pathways.

CONCLUSION

The serum expression levels of some HF-related miRNAs in HF patients tended towards fetal levels. Among them, miR-210 and miR-30a were elevated in the HF and fetus groups.

Circulating microRNAs: a novel class of potential biomarkers for diagnosing and prognosing central nervous system diseases

As a class of important endogenous small noncoding RNAs that regulate gene expression at the posttranscriptional level, microRNAs (miRNAs) play a critical role in many physiological and pathological processes. It is believed that miRNAs contribute to the development, differentiation, and synaptic plasticity of the neurons, and their dysregulation has been linked to a series of diseases. MiRNAs exist in the tissues and as circulating miRNAs in several body fluids, including plasma or serum, cerebrospinal fluid, urine, and saliva. There are significant differences between the circulating miRNA expression profiles of healthy individuals and those of patients. Consequently, circulating miRNAs are likely to become a novel class of noninvasive and sensitive biomarkers. Although little is known about the origin and functions of circulating miRNAs at present, their roles in the clinical diagnosis and prognosis of diseases make them attractive markers, particularly for tumors and cardiovascular diseases. Until now, however, there have been limited data regarding the roles of circulating miRNAs in central nervous system (CNS) diseases. This review focuses on the characteristics of circulating miRNAs and their values as potential biomarkers in CNS diseases, particularly in Alzheimer's disease, Huntington's disease, multiple sclerosis, schizophrenia, and bipolar disorder.

Circulating miRNAs: novel biomarkers of acute coronary syndrome?

Acute coronary syndrome refers to any group of clinical symptoms compatible with acute myocardial infarction (AMI). AMI is a major cause of death and disability worldwide with the greatest risk of death within the first hours of AMI onset. Therefore, delays in ‘ruling in’ AMI may increase morbidity and mortality due to the time lag in initiating therapy. Likewise, since the majority of patients presenting with acute chest pain do not have AMI, the rapid ‘ruling out’ of AMI in those patients would increase emergency department triage efficiency, decrease medical costs, and reduce morbidity and mortality. Thus, the identification of novel biomarkers that improve current strategies and/or accurately identify subjects who are at risk of developing acute and chronic manifestations of cardiovascular disease are desperately needed. This article discusses the potential of peripheral blood microRNAs as clinical biomarkers for the diagnosis and prognosis of cardiovascular diseases such as AMI.

Expression of serum miR-20a-5p, let-7a, and miR-320a and their correlations with pepsinogen in atrophic gastritis and gastric cancer: a case-control study

Background

The identification of serial miRNAs targeting the same functional gastric protein could provide new and effective serological biomarkers for the diagnosis of gastric cancer (GC). The aim of this study was to evaluate the potential of miR-20a-5p, let-7a and miR-320a in the diagnosis of AG or GC and the correlation of the three miRNAs with their predicted target molecules PGA, PGC and PGA/PGC ratio.

Methods

The total of 291 patients included 103 controls (CON), 94 with atrophic gastritis (AG) and 94 with GC. The levels of serum miRNAs were detected by quantitative reverse transcription-polymerase chain reaction and serum pepsinogen A (PGA) and C (PGC) were determined by enzyme-linked immunosorbent assays.

Results

Serum miR-320a level decreased through the controls, AG and GC groups which were the cascades of GC development, while there were no significant differences in levels of miR-20a-5p and let-7a among the controls, AG and GC groups. When stratified by gender and age, serum miR-320a expression was lower in female GC patients than in controls (p = 0.035), especially in female GC patients older than 60 years (p = 0.008). For distinguishing female GC patients aged over 60, the area under the receiver operating characteristic curve for miR-320a was 0.699, and the best cut-off point was 4.76 with a sensitivity of 65.2% and specificity of 68.2%. Concerning the correlations between the selected miR-20a-5p, let-7a, miR-320a and PGs, we found that there were positive correlations between all the three and the ratio of PGA/PGC (r = 0.408, 0.255, 0.324; p = <0.001, 0.009, 0.001, respectively), but there was no relationship between the expression of serum miR-20a-5p and its predicted target PGA, or between let-7a and miR-320a and their predicted target PGC. Serum miR-320a was decreased and PGC was increased in the GC group compared with the control group.

Conclusions

Levels of serum miR-320a were lower in female GC patients older than 60 than in controls, which may provide a potential valuable marker for diagnosing older women with GC. The levels of serum miR-20a-5p, let-7a and miR-320a were positively correlated with PGA/PGC, which may indirectly reflect the functional status of the gastric mucosa.

Circulating cardio-enriched microRNAs are associated with long-term prognosis following myocardial infarction

Background

Increased levels of cardio-enriched microRNAs (miRNAs) have been described in patients with myocardial infarction (MI). We wanted to evaluate the diagnostic and prognostic potential of cardio-enriched miRNAs in patients presenting with a suspected acute coronary syndrome (ACS).

Methods

Cardio-enriched miRNAs (miR-1, miR-208b and miR-499-5p) were measured using real time PCR in plasma samples from 424 patients with suspected ACS treated in a coronary care unit. miRNAs were assessed for discrimination of a clinical diagnosis of myocardial infarction and for association with 30-day mortality and diagnosis of heart failure. Correlation with left ventricular systolic dysfunction as measured by the ejection fraction (LVEF) was also assessed. To confirm myocardial origin miRNA was measured during coronary artery bypass surgery.

Results

miRNAs were higher in MI patients and correlated with LVEF (p < 0.001). Discrimination of MI was accurate for miR-208b (AUC = 0.82) and miR-499-5p (AUC = 0.79) but considerable lower than for Troponin T (AUC = 0.95). Increased miRNA levels were strongly associated with increased risk of mortality or heart failure within 30 days for miR-208b (OR 1.79, 95% CI = 1.38-2.23, p = 1 × 10^-5) and miR-499-5p (OR 1.70, 95% CI = 1.31-2.20, p = 5 × 10^-5) but the association was lost when adjusting for Troponin T. During surgery miR-208b and miR-499-5p was released in the coronary sinus after cardioplegia-reperfusion to markedly higher levels than in a peripheral vein.

Conclusions

Our findings confirm increased levels of cardio-enriched miRNAs in the blood of MI patients and establish association of increased miRNA levels with reduced systolic function after MI and risk of death or heart failure.

Circulating microRNAs and aerobic fitness--the HUNT-Study

Aerobic fitness, measured as maximal oxygen uptake (VO2max), is a good indicator of cardiovascular health, and a strong predictor of cardiovascular mortality. Biomarkers associated with low VO2max may therefore represent potential early markers of future cardiovascular disease (CVD). The aim of this study was to assess whether circulating microRNAs (miRs) are associated with VO2max-level in healthy individuals. In a screening study, 720 miRs were measured in serum samples from healthy individuals (40-45 yrs) with high (n = 12) or low (n = 12) VO2max matched for gender, age and physical activity. Candiate miRs were validated in a second cohort of subjects with high (n = 38) or low (n = 38) VO2max. miR-210 and miR-222 were found to be higher in the low VO2max-group (p<0.05). In addition, miR-21 was increased in male participants with low VO2max (p<0.05). There were no correlations between traditional risk factors for CVD (blood pressure, cholesterol, smoking habit, or obesity) and miR-21, miR-210 and miR-222. DIANA-mirPath identified 611 potential gene-targets of miR-21, miR-210 and miR-222, and pathway analysis indicated alterations in several important signaling systems in subjects with low VO2max. Potential bias involve that blood was collected from non-fasting individuals, and that 8 performed exercise within 24 h before sampling. In conclusion, we found that miR-210, miR-21, and miR-222 were increased in healthy subjects with low VO2max. The lack of association between these three miRs, and other fitness related variables as well as traditional CVD risk factors, suggests that these miRs may have a potential as new independent biomarkers of fitness level and future CVD.

Identification of sensitive serum microRNA biomarkers for radiation biodosimetry

Exposure to ionizing radiation through environmental, occupational or a nuclear reactor accident such as the recent Fukushima Daiichi incident often results in major consequences to human health. The injury caused by radiation can manifest as acute radiation syndromes within weeks in organs with proliferating cells such as hematopoietic and gastrointestinal systems. Cancers, fibrosis and degenerative diseases are also reported in organs with differentiated cells, months or years later. Studies conducted on atom bomb survivors, nuclear reactor workers and animal models have shown a direct correlation of these effects with the absorbed dose. Physical dosimeters and the available radio-responsive biologics in body fluids, whose responses are rather indirect, have limitations to accurately evaluate the extent of post exposure damage. We have used an amplification-free, hybridization based quantitative assay utilizing the nCounter multiplex platform developed by nanoString Technologies to compare the levels of over 600 miRNAs in serum from mice irradiated at a range of 1 to 12 Gy at 24 and 48 hr time points. Development of a novel normalization strategy using multiple spike-in oligonucleotides allowed accurate measurement of radiation dose and time dependent changes in serum miRNAs. The response of several evolutionarily conserved miRNAs abundant in serum, were found to be robust and sensitive in the dose range relevant for medical triage and in patients who receive total body radiation as preparative regimen for bone marrow transplantation. Notably, miRNA-150, abundant in lymphocytes, exhibited a dose and time dependent decrease in serum, which we propose as a sensitive marker indicative of lymphocyte depletion and bone marrow damage. Our study has identified several markers useful for evaluation of an individual's response by minimally invasive methods, relevant to triage in case of a radiation accident and evaluation of toxicity and response during and after therapeutic radiation.

Serum microRNA expression profile: miR-1246 as a novel diagnostic and prognostic biomarker for oesophageal squamous cell carcinoma

Background:

Recent studies have demonstrated that microRNAs (miRNAs) are stably detectable in blood and can serve as useful biomarkers for cancer.

Methods:

We performed an miRNA array using serum samples obtained from oesophageal squamous cell carcinoma (ESCC) patients or healthy controls. MiR-1246 was the most markedly elevated in ESCC patients. Therefore, miR-1246 was selected as a candidate for further analysis. The serum miR-1246 level in 46 healthy controls and 101 ESCC patients was evaluated and compared among various clinicopathological characteristics. MiR-1246 expressions in tissue, exosomal, and cellular samples were also examined.

Results:

Serum miR-1246 alone yielded an receiver-operating characteristic curve area of 0.754, with 71.3% sensitivity and 73.9% specificity for distinguishing ESCC patients from healthy controls. Serum miR-1246 was significantly correlated with the TNM stage and showed to be the strongest independent risk factor for poor survival (HR, 4.032; P=0.017). Unlike the tendency shown in previous reports, miR-1246 was not upregulated in ESCC tissue samples. Furthermore, exosomal miR-1246 did not reflect the abundance in the cell of origin.

Conclusion:

These data support our contention that serum miR-1246 has strong potential as a novel diagnostic and prognostic biomarker in ESCC, and its releasing mechanism is selective and independent of tissue miRNA abundance.