Circulating miRNAs in Ageing and Ageing-Related Diseases

MicroRNAs （miRNAs） are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. They are involved in important biological processes including development, homeostasis, and ageing. Recently, extracellular miRNAs have been discovered in the bloodstream and bodily fluids. These miRNAs are shown to be secreted and circulating in microvesicles （MVs）, or in complex with other factors such as RNA-binding proteins and high-density lipoprotein （HDL） particles. These cell-free, circulating miRNAs can be taken into and function as negative regulators of target genes in recipient cells. Here we review the biogenesis and uptake of circulating miRNAs as well as their profiles in ageing and ageing-related diseases. We discuss the emerging role of circulating miRNAs as biomarkers and therapeutic targets.

An ultra-sensitive biosensor for circulating microRNA detection with Fe single-atom enhanced cathodic luminol-O2 electrochemiluminescence

Circulating microRNAs(miRNAs)play a pivotal role in the occurrence and development of acute myocardial infarction(AMI),and precise detection of them holds significant clinical implications.The development of luminol-based luminophores in the field of electrochemiluminescence(ECL)for miRNA detection has been significant,while their effectiveness is hindered by the instability of co-reactant hydrogen peroxide(H_(2)O_(2)).In this work,an iron single-atom catalyst(Fe-PNC)was employed for catalyzing the luminol-O2 ECL system to achieve ultra-sensitive detection of myocardial miRNA.Target miRNA triggers a hybridization chain reaction(HCR),resulting in the generation of a DNA product featuring multiple sticky ends that facilitate the attachment of Fe-PNC probes to the electrode surface.The Fe-PNC catalyst exhibits high promise and efficiency for the oxygen reduction reaction(ORR)in electrochemical energy conversion systems.The resulting ECL biosensor allowed ultrasensitive detection of myocardial miRNA with a low detection limit of 0.42 fM and a wide linear range from 1 fM to 1.0 nM.Additionally,it demonstrates exceptional performance when evaluated using serum samples collected from patients with AMI.This work expands the application of single-atom catalysis in ECL sensing and introduces novel perspectives for utilizing ECL in disease diagnosis.

Novel insights regarding the role of noncoding RNAs in diabetes

Diabetes mellitus(DM)is a group of metabolic disorders defined by hyperglycemia induced by insulin resistance,inadequate insulin secretion,or excessive glucagon secretion.In 2021,the global prevalence of diabetes is anticipated to be 10.7%(537 million people).Noncoding RNAs(ncRNAs)appear to have an important role in the initiation and progression of DM,according to a growing body of research.The two major groups of ncRNAs implicated in diabetic disorders are miRNAs and long noncoding RNAs.miRNAs are singlestranded,short(17–25 nucleotides),ncRNAs that influence gene expression at the post-transcriptional level.Because DM has reached epidemic proportions worldwide,it appears that novel diagnostic and therapeutic strategies are required to identify and treat complications associated with these diseases efficiently.miRNAs are gaining attention as biomarkers for DM diagnosis and potential treatment due to their function in maintaining physiological homeostasis via gene expression regulation.In this review,we address the issue of the gradually expanding global prevalence of DM by presenting a complete and upto-date synopsis of various regulatory miRNAs involved in these disorders.We hope this review will spark discussion about ncRNAs as prognostic biomarkers and therapeutic tools for DM.We examine and synthesize recent research that used novel,high-throughput technologies to uncover ncRNAs involved in DM,necessitating a systematic approach to examining and summarizing their roles and possible diagnostic and therapeutic uses.

Evaluation of P-glycoprotein-targeting circulating microRNAs as peripheral biomarkers for medically intractable epilepsy

Background Early diagnosis of medically intractable epilepsy is challenging in clinical work.P-glycoprotein(P-gp)is one of the most important multidrug efux transporters,which has been demonstrated to contribute to the drug resistance of intractable epilepsy.The present study was aimed to explore the diagnostic value of microRNAs(miRNAs)targeting P-gp for medically intractable epilepsy.Methods Thirty-six patients with intractable epilepsy and 36 epilepsy patients responsive to anti-epilepsy drugs,who visited Jinshan Hospital of Fudan University from September 2014 to September 2016,were enrolled in this study.Clinical information of the patients was obtained by retrospectively reviewing medical records.MiRNAs with diferential serum expression between the two groups of patients were detected by microarray assay.Meanwhile,miRNAs that were confrmed to regulate P-gp in vitro by western blot were selected for further validation.In the validation phase,reverse transcription quantitative PCR(RT-qPCR)was conducted to confrm the diferential expression of the candidate miRNAs in the epilepsy cohorts.Receiver operating characteristic(ROC)curve analysis was carried out to evaluate the diagnostic value of the miRNAs for intractable epilepsy.Results Three miRNAs including miR-6514-3p,miR-6076-5p,and miR-6855-3p were identifed to be candidate miRNAs by microarray assay.The results of western blotting validated that miR-146a-5p and miR-138-5p could regulate P-gp expression in vitro,so they were included in the candidate miRNAs for further validation.In the validation phase,the results of RT-qPCR indicated that compared with drug-responsive patients,the patients with intractable epilepsy showed decreased level of miR-138-5p and increased level of miR-146a-5p.The results of ROC curve analysis indicated that miR-138-5p(AUC=0.877)and miR-146a-5p(AUC=0.866)had high diagnostic value for intractable epilepsy.In addition,the miR-panel composed of miR-138-5p and miR-146a-5p showed higher diagnostic value(AUC=0.926)than the miRNAs selected by microarray assay.Conclusions Our results indicated that the dysregulated miR-138-5p and miR-146a-5p which target P-gp expression have high potential as peripheral biomarkers for medically intractable epilepsy.

Vegetarian diets,circulating miRNA expression and healthspan in subjects living in the Blue Zone

A long-term vegetarian diet plays a role in the longevity and maintenance of the healthspan,but the underlying mechanisms for these observations are largely unknown.Particularly,it is not known whether a longterm vegetarian dietary pattern may affect the circulating miRNA expression in such a way as to modulate the healthspan.The Adventist Health Study-2(AHS-2)cohort includes a large number of older adults who primarily follow vegetarian dietary patterns and reside in Loma Linda,California,one of five“Blue Zones”in the world in which a higher proportion of the population enjoys a longer than average lifespan.We performedmiRNA-seq in 96 subjects selected from the AHS-2 cohort with different dietary patterns.We identified several differentially expressed miRNAs between vegetarians and non-vegetarians,which are involved in immune response and cytokine signaling,cell growth and proliferation as well as age-related diseases such as cardiovascular diseases and neurodegenerative diseases.Overall,our study showed that a vegetarian diet modulates aging-associated circulating miRNAs in a sex-dependent manner of differential expression for certain miRNAs,which may be related in a beneficial manner to the healthspan.Further investigation is needed to validate these miRNAs as potential biomarkers for diet-modulated longevity in humans.

A pilot study of microRNAs as a new potential biomarkers for hypertension

Background Micro RNAs have recently been considered as biomarkers in several different cardiovascular diseases,however,so far there are no circulating miRNAs data about hypertension.Therefore,the aim of the present pilot study was to identify circulating miRNAs for hypertension biomarkers.Methods Using an Agilent microarray,plasma miRNAs were profiled from plasma samples of 10 patients with untreated essential hypertension and 10 healthy controls.Candidate biomarkers identified in the profiles were subjected to validation by using quantitative PCR in an independent sample set of 20 patients with untreated essential hypertension and 20 healthy controls.Then,we assessed the selected miRNAs for the detection and diagnosis of hypertension from plasma samples of 70 patients with untreated essential hypertension and 20 healthy controls.The Spearman correlation coefficient was used to assessed the selected miRNAs correlations with blood pressure.The area under the receiver operating characteristic curve（AUC） was used to evaluate diagnostic accuracy.Results The expressions of selected 8 miRNAs were investigated independently in plasma samples from 10 hypertension patients and 10 healthy subjects.The levels of circulating miR-30c-5p,miR-133 b,miR-29b-3p,miR-29a-3p,miR-29c-3p,miR-30a-3p,miR-let7b-3p expression were significantly down regulated in hypertension group compared with healthy group and the level of hsa-miR-92b-3p was significantly unregulated between the groups.We used q RT-PCR assay to confirm the expression of 8 candidate miRNAs,miR-30c-5p（P 〈 0.001）,miR-29b-3p（P 〈 0.001）,miR-29a-3p（P = 0.027）,miR-29c-3p（P 〈 0.001）,miR-92b-3p（P = 0.003）,miR-30a-3p（P = 0.704）,miR-133b（P =0.346）,andmiR-let7b（P = 0.161）.The diagnostic accuracy of miR-30c-5p,miR-29b-3p,miR-29a-3p,miR-29c-3p and miR-92b-3p,as measured by AUC,were 0.897,0.90,0.829,0.825 and 0.832,respectively,with all P 〈0.001.Conclusions The plasma levels of miR-30c-5p,miR-29b-3p,miR-29a-3p,miR-29c-3p and miR-92b-3p associated with hypertension which provide an impetus for future evaluations of hypertension development,progression,therapeutic efficacy and prognosis.