Circulating levels and the bioactivity of miR-30b increase during pubertal progression in boys.

Background: Puberty marks the transition from childhood to adulthood and is initiated by activation of a pulsatile GnRH secretion from the hypothalamus. MKRN3 functions as a pre-pubertal break on the GnRH pulse generator and hypothalamic expression and circulating levels of MKRN3 decrease peri-pubertally. In rodents, microRNA miR-30b seems to directly target hypothalamic MKRN3 expression - and in boys, circulating levels of miR-30b-5p increase when puberty is pharmacologically induced. Similarly, miR-200b-3p and miR-155-5p have been suggested to inhibit expression of other proteins potentially involved in the regulation of GnRH secretion. Here we measure circulating levels of these three miRNAs as boys progress through puberty. Materials and Methods: Forty-six boys from the longitudinal part of the Copenhagen Puberty Study were included. All boys underwent successive clinical examinations including estimation of testis size by palpation. miR-30b-5p, miR-200b-3p, and miR-155-5p were measured in serum by RT-qPCR using a kit sensitive to the phosphorylation status of the miRNAs. Thirty-nine boys had miRNA levels measured in three consecutive samples (pre-, peri-, and post-pubertally) and seven boys had miR-30b-5p levels measured in ten consecutive samples during the pubertal transition. Results: When circulating levels of miR-30b-5p in pre- and peri-pubertal samples were compared with post-pubertal levels, we observed a significant increase of 2.3 and 2.2-fold (p-value<6.0×10-4), respectively, and a larger fraction of miR-30b-5p appeared to be phosphorylated post-pubertally indicating an increase in its bioactivity. We also observed a negative correlation between circulating levels of miR-30b-5p and MKRN3. The inter-individual variation in circulating miR-30b levels was substantial and we could not define a clinical threshold for miR-30b-5p suggestive of imminent puberty. Also, miR-155-5p showed significantly increasing levels from the peri- to the post-pubertal stage (p=3.0×10-3), whereas miR-200b-3p did not consistently increase. Conclusion: Both circulating levels of miR-30b-5p and its bioactivity increase during the pubertal transition in boys supporting its role in the activation of the HPG axis at the onset of physiologically normal puberty.

Acute green tea intake attenuates circulating microRNA expression induced by a high-fat, high-saturated meal in obese women: A randomized crossover study.

The objective of this study was to assess whether acute green tea (GT) supplementation attenuates inflammatory and oxidative stress biomarkers induced by high-fat, high-saturated (HFHS) meals in obese women, and to assess its ability to modulate circulating microRNA (miRNA) expression. This was a randomized, double-blind, crossover study. The study included obese women over 18 years old who had no comorbidities. In the first moment, patients were instructed to take 2 capsules of placebo or GT (738 mg) at 10:00 p.m. and to fast overnight. The next morning, a blood sample was collected, and an HFHS meal was offered to the patients. Another blood sample was collected 5 hours after the meal. In the second moment, patients who received placebo in the first moment now received the GT and vice-versa. Serum inflammatory and oxidative stress biomarkers were measured, and circulating levels of miRNA were evaluated. Fifteen women with mean age of 35.5±9.9 years were included in the final analysis. There was no difference regarding inflammatory and oxidative stress biomarkers. However, patients who consumed GT had lower circulating expression of 62 miRNAs compared with patients who did not consume GT. Predictive analysis of target genes showed 1,757 targets regulated by the 62 miRNAs. Notably, 5 miRNAs (miR-1297, miR-192-5p, miR-373-3p, miR-595 and miR-1266-5p) regulate genes associated with TGF-beta, CARM1, RSK, and BMP pathways. Our study showed that GT inhibited the expression of miRNAs induced by HFHS meal intake. These results shed light on the mechanisms involved in the beneficial effects of GT ingestion.

Circulating MicroRNAs as a New Class of Biomarkers of Physiological Reactions of the Organism to the Intake of Dietary Supplements and Drugs.

BACKGROUND: The analysis of individual microRNAs (miRNAs) as a diagnostic and prognostic tool for the effective treatment of various diseases has aroused particular interest in the scientific community. The determination of circulating miRNAs makes it possible to assess biological changes associated with nutritional processes, the intake of dietary supplements and drugs, etc. The profile of circulating miRNAs reflects the individual adaptation of the organism to the effect of specific environmental conditions. OBJECTIVE: The objective of this study is to systematize the data and show the importance of circulating miRNAs as new potential biomarkers of the organism's response to the intake of various dietary supplements, drugs, and consider the possibility of their use in doping control. METHODS: A systematic analysis of scientific publications (ncbi.nlm.nih.gov) on the miRNA expression profile in response to the intake of dietary supplements and drugs most often used by athletes, and supposed their role as potential markers in modern doping control was carried out. RESULTS: The profile of circulating miRNAs is highly dependent on the intake of a particular drug, and, therefore, may be used as a marker of the effects of biologically active supplements and drugs including the substances from the Prohibited List of the World Anti-Doping Agency (WADA). CONCLUSION: Monitoring of circulating miRNAs can serve as a high-precision marker for detecting doping abuse in elite sports. However, it is necessary to conduct additional studies on the effect of complex drugs on the profile of circulating miRNAs and individual circulating miRNAs on a particular biological process.

A MicroRNA Signature in Acute Coronary Syndrome Patients and Modulation by Colchicine.

BACKGROUND: Circulating microRNAs (miRNAs) may play a pathogenic role in acute coronary syndromes (ACS). It is not yet known if miRNAs dysregulated in ACS are modulated by colchicine. We profiled miRNAs in plasma samples simultaneously collected from the aorta, coronary sinus, and right atrium in patients with ACS. METHODS: A total of 396 of 754 miRNAs were detected by TaqMan real-time polymerase chain reaction from EDTA-plasma in a discovery cohort of 15 patients (n = 3 controls, n = 6 ACS standard therapy, n = 6 ACS standard therapy plus colchicine). Fifty-one significantly different miRNAs were then measured in a verification cohort of 92 patients (n = 13 controls, n = 40 ACS standard therapy, n = 39 ACS standard therapy plus colchicine). Samples were simultaneously obtained from the coronary sinus, aortic root, and right atrium. RESULTS: Circulating levels of 30 of 51 measured miRNAs were higher in ACS standard therapy patients compared to controls. In patients with ACS, levels of 12 miRNAs (miR-17, -106b-3p, -191, -106a, -146a, -130a, -223, -484, -889, -425-3p, -629, -142-5p) were lower with colchicine treatment. Levels of 7 of these 12 miRNA were higher in ACS standard therapy patients compared to controls and returned to levels seen in control individuals after colchicine treatment. Three miRNAs suppressed by colchicine (miR-146a, miR-17, miR-130a) were identified as regulators of inflammatory pathways. MicroRNAs were comparable across sampling sites with select differences in the transcoronary gradient of 4 miRNA. CONCLUSION: The levels of specific miRNAs elevated in ACS returned to levels similar to control individuals following colchicine. These miRNAs may mediate ACS (via inflammatory pathways) or increase post-ACS risk, and could be potentially used as biomarkers of treatment efficacy.

Panoramic Visualization of Circulating MicroRNAs Across Neurodegenerative Diseases in Humans.

Neurodegenerative diseases (NDs) such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and dementia pose one of the greatest health challenges this century. Although these NDs have been looked at as single entities, the underlying molecular mechanisms have never been collectively visualized to date. With the advent of high-throughput genomic and proteomic technologies, we now have the opportunity to visualize these diseases in a whole new perspective, which will provide a clear understanding of the primary and secondary events vital in achieving the final resolution of these diseases guiding us to new treatment strategies to possibly treat these diseases together. We created a knowledge base of all microRNAs known to be differentially expressed in various body fluids of ND patients. We then used several bioinformatic methods to understand the functional intersections and differences between AD, PD, ALS, and MS. These results provide a unique panoramic view of possible functional intersections between AD, PD, MS, and ALS at the level of microRNA and their cognate genes and pathways, along with the entities that unify and separate them. While the microRNA signatures were apparent for each ND, the unique observation in our study was that hsa-miR-30b-5p overlapped between all four NDS, and has significant functional roles described across NDs. Furthermore, our results also show the evidence of functional convergence of miRNAs which was associated with the regulation of their cognate genes represented in pathways that included fatty acid synthesis and metabolism, ECM receptor interactions, prion diseases, and several signaling pathways critical to neuron differentiation and survival, underpinning their relevance in NDs. Envisioning this group of NDs together has allowed us to propose new ways of utilizing circulating miRNAs as biomarkers  and in visualizing diverse NDs more holistically . The critical molecular insights gained through the discovery of ND-associated miRNAs, overlapping miRNAs, and the functional convergence of microRNAs on vital pathways strongly implicated in neurodegenerative processes can prove immensely valuable in the identifying new generation of biomarkers, along with the development of miRNAs into therapeutics.

Circulating MicroRNA-21 Correlates With Left Atrial Low-Voltage Areas and Is Associated With Procedure Outcome in Patients Undergoing Atrial Fibrillation Ablation.

BACKGROUND: Atrial fibrosis is a hallmark of arrhythmogenic structural remodeling in patients with persistent atrial fibrillation (AF) and is negatively correlated with procedure outcome in patients undergoing ablation. However, noninvasive methods to determine the extent of atrial fibrosis are limited. Here, we used microRNA (miRNA) expression analysis to detect markers of left atrial low-voltage areas (LVAs) in patients with persistent AF undergoing catheter ablation. METHODS: We performed 3-dimensional voltage mapping in 102 patients (average age 62.1±13.1 years, CHA2DS2-VASc score of 2.3±1.6, LA size 41.5±5.7 mm) undergoing ablation for persistent AF and determined the extent of left atrial low-voltage. LVAs were defined if bipolar electrogram amplitudes were <0.5 mV during sinus rhythm. Before ablation, we obtained a blood sample, isolated miRNAs, and profiled them on a miRCURY LNA Universal RT microRNA PCR Human panel. RESULTS: Sixty-nine miRNAs were identified in all samples, with an average of 123 miRNAs detectable per sample. We found that the serum concentration of miR-21, a miRNA that has been previously linked to cardiac fibrosis development, was strongly associated with the extent of LVAs determined by voltage mapping. We could confirm that LVAs were negatively correlated with ablation success in a 1-year follow-up. In addition, miR-21 serum levels were associated with AF-free survival after catheter ablation. CONCLUSIONS: Circulating miR-21 correlates with left atrial LVAs and is associated with procedure outcome in patients with persistent AF undergoing ablation.