microRNA expression patterns reveal differential expression of target genes with age

Epigenetic biomarkers in aging and longevity: Current and future application

The aging process has been one of the most necessary research fields in the current century, and knowing different theories of aging and the role of different genetic, epigenetic, molecular, and environmental modulating factors in increasing the knowledge of aging mechanisms and developing appropriate diagnostic, therapeutic, and preventive ways would be helpful. One of the most conserved signs of aging is epigenetic changes, including DNA methylation, histone modifications, chromatin remodeling, noncoding RNAs, and extracellular RNAs. Numerous biological processes and hallmarks are vital in aging development, but epigenomic alterations are especially notable because of their importance in gene regulation and cellular identity. The mounting evidence points to a possible interaction between age-related epigenomic alterations and other aging hallmarks, like genome instability. To extend a healthy lifespan and possibly reverse some facets of aging and aging-related diseases, it will be crucial to comprehend global and locus-specific epigenomic modifications and recognize corresponding regulators of health and longevity. In the current study, we will aim to discuss the role of epigenomic mechanisms in aging and the most recent developments in epigenetic diagnostic biomarkers, which have the potential to focus efforts on reversing the destructive signs of aging and extending the lifespan.

Exposure to per- and polyfluoroalkyl substances and alterations in plasma microRNA profiles in children

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals that persist in the environment and can accumulate in humans, leading to adverse health effects. MicroRNAs (miRNAs) are emerging biomarkers that can advance the understanding of the mechanisms of PFAS effects on human health. However, little is known about the associations between PFAS exposures and miRNA alterations in humans.

OBJECTIVE

To investigate associations between PFAS concentrations and miRNA levels in children.

METHODS

Data from two distinct cohorts were utilized: 176 participants (average age 16.6 years; 75.6% female) from the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) cohort in the United States, and 64 participants (average age 6.5 years, 39.1% female) from the Rhea study, a mother-child cohort in Greece. PFAS concentrations and miRNA levels were assessed in plasma samples from both studies. Associations between individual PFAS and plasma miRNA levels were examined after adjusting for covariates. Additionally, the cumulative effects of PFAS mixtures were evaluated using an exposure burden score. Ingenuity Pathways Analysis was employed to identify potential disease functions of PFAS-associated miRNAs.

RESULTS

Plasma PFAS concentrations were associated with alterations in 476 miRNAs in the Teen-LABs study and 13 miRNAs in the Rhea study (FDR p < 0.1). Specifically, plasma PFAS concentrations were consistently associated with decreased levels of miR-148b-3p and miR-29a-3p in both cohorts. Pathway analysis indicated that PFAS-related miRNAs were linked to numerous chronic disease pathways, including cardiovascular diseases, inflammatory conditions, and carcinogenesis.

CONCLUSION

Through miRNA screenings in two independent cohorts, this study identified both known and novel miRNAs associated with PFAS exposure in children. Pathway analysis revealed the involvement of these miRNAs in several cancer and inflammation-related pathways. Further studies are warranted to enhance our understanding of the relationships between PFAS exposure and disease risks, with miRNA emerging as potential biomarkers and/or mediators in these complex pathways.

Regulation of the HIF switch in human endothelial and cancer cells

Hypoxia-inducible factors (HIFs) are transcription factors that reprogram the transcriptome for cells to survive hypoxic insults and oxidative stress. They are important during embryonic development and reprogram the cells to utilize glycolysis when the oxygen levels are extremely low. This metabolic change facilitates normal cell survival as well as cancer cell survival. The key feature in survival is the transition between acute hypoxia and chronic hypoxia, and this is regulated by the transition between HIF-1 expression and HIF-2/HIF-3 expression. This transition is observed in many human cancers and endothelial cells and referred to as the HIF Switch. Here we discuss the mechanisms involved in the HIF Switch in human endothelial and cancer cells which include mRNA and protein levels of the alpha chains of the HIFs. A major continuing effort in this field is directed towards determining the differences between normal and tumor cell utilization of this important pathway, and how this could lead to potential therapeutic approaches.

Influence of analytical procedures on miRNA expression analyses in saliva samples

Aim of this study was to demonstrate the influence of different analytical procedures and techniques on the resulting miRNA expression profile in healthy control subjects and tumor patients using the oral squamous cell carcinoma (OSCC) model and to demonstrate the technical and biological reproducibility. Body fluids such as saliva are suitable for non-invasive miRNA analysis because ubiquitously circulating miRNA can be found in them. It was technically possible to distinguish between healthy and diseased samples based on the miRNA expression profile found. Regardless of the methodology used, good technical reproducibility of the results seems to be achievable. On the other hand, biological reproducibility was inadequate, which is why prompt sampling and sequencing is recommended. The data indicate that malignant lesions can be detected using miRNA signatures extracted from saliva. This could stimulate further research to establish standardized protocols and kits for sample collection, miRNA extraction, sequencing and interpretation of results.

The Benefits of the Mediterranean Diet on Inflamm-Aging in Childhood Obesity

(1) Background: Numerous elements of the Mediterranean diet (MD) have antioxidant and anti-inflammatory qualities. (2) Methods: We present a narrative review of the potential benefits of the Mediterranean dietary pattern (MD) in mitigating aging-related inflammation (inflamm-aging) associated with childhood obesity. The mechanisms underlying chronic inflammation in obesity are also discussed. A total of 130 papers were included after screening abstracts and full texts. (3) Results: A complex interplay between obesity, chronic inflammation, and related comorbidities is documented. The MD emerges as a promising dietary pattern for mitigating inflammation. Studies suggest that the MD may contribute to weight control, improved lipid profiles, insulin sensitivity, and endothelial function, thereby reducing the risk of metabolic syndrome in children and adolescents with obesity. (4) Conclusions: While evidence supporting the anti-inflammatory effects of the MD in pediatric obesity is still evolving, the existing literature underscores its potential as a preventive and therapeutic strategy. However, MD adherence remains low among children and adolescents, necessitating targeted interventions to promote healthier dietary habits. Future high-quality intervention studies are necessary to elucidate the specific impact of the MD on inflammation in diverse pediatric populations with obesity and associated comorbidities.

AMPK-upregulated microRNA-708 plays as a suppressor of cellular senescence and aging via downregulating disabled-2 and mTORC1 activation

Senescence-associated microRNAs (SA-miRNAs) are important molecules for aging regulation. While many aging-promoting SA-miRNAs have been identified, confirmed aging-suppressive SA-miRNAs are rare, that impeded our full understanding on aging regulation. In this study, we verified that miR-708 expression is decreased in senescent cells and aged tissues and revealed that miR-708 overexpression can alleviate cellular senescence and aging performance. About the molecular cascade carrying the aging suppressive action of miR-708, we unraveled that miR-708 directly targets the 3'UTR of the disabled 2 (Dab2) gene and inhibits the expression of DAB2. Interestingly, miR-708-caused DAB2 downregulation blocks the aberrant mammalian target of rapamycin complex 1 (mTORC1) activation, a driving metabolic event for senescence progression, and restores the impaired autophagy, a downstream event of aberrant mTORC1 activation. We also found that AMP-activated protein kinase (AMPK) activation can upregulate miR-708 via the elevation of DICER expression, and miR-708 inhibitor is able to blunt the antiaging effect of AMPK. In summary, this study characterized miR-708 as an aging-suppressive SA-miRNA for the first time and uncovered a new signaling cascade, in which miR-708 links the DAB2/mTOR axis and AMPK/DICER axis together. These findings not only demonstrate the potential role of miR-708 in aging regulation, but also expand the signaling network connecting AMPK and mTORC1.

Research progress and potential application of microRNA and other non-coding RNAs in forensic medicine

At present, epigenetic markers have been extensively studied in various fields and have a high value in forensic medicine due to their unique mode of inheritance, which does not involve DNA sequence alterations. As an epigenetic phenomenon that plays an important role in gene expression, non-coding RNAs (ncRNAs) act as key factors mediating gene silencing, participating in cell division, and regulating immune response and other important biological processes. With the development of molecular biology, genetics, bioinformatics, and next-generation sequencing (NGS) technology, ncRNAs such as microRNA (miRNA), circular RNA (circRNA), long non-coding RNA (lncRNA), and P-element induced wimpy testis (PIWI)-interacting RNA (piRNA) are increasingly been shown to have potential in the practice of forensic medicine. NcRNAs, mainly miRNA, may provide new strategies and methods for the identification of tissues and body fluids, cause-of-death analysis, time-related estimation, age estimation, and the identification of monozygotic twins. In this review, we describe the research progress and application status of ncRNAs, mainly miRNA, and other ncRNAs such as circRNA, lncRNA, and piRNA, in forensic practice, including the identification of tissues and body fluids, cause-of-death analysis, time-related estimation, age estimation, and the identification of monozygotic twins. The close links between ncRNAs and forensic medicine are presented, and their research values and application prospects in forensic medicine are also discussed.

Exploring miR-155-5p and miR-1246 as Diagnostic and Prognostic Markers in Oral Squamous cell carcinoma

INTRODUCTION

Oral Squamous Cell Carcinoma (OSCC) is one of the leading cancers worldwide, significantly impacting developing nations. This study aimed to explore the diagnostic and prognostic potential of miR-155-5p and miR-1246 in OSCC in the Indian population, as their comparative roles in this context remain unexplored.

MATERIAL AND METHODS

The present cross-sectional study comprised 50 histopathologically confirmed OSCC cases, with adjacent normal mucosa as controls. MiRNA expression was assessed via qRT-PCR and correlated with clinicopathological factors. MiRwalk and miRTargetlink were used for miRNA:mRNA interaction prediction, and gprofiler was employed to analyze validated targets for functional insights.

RESULTS

The expression analysis showed a significant upregulation of miR-155-5p and miR-1246 in OSCC tissues compared to adjacent controls. Receiver operating curve analysis revealed that miR-1246 exhibited excellent diagnostic accuracy (AUC = 0.94) compared to miR-155-5p (AUC = 0.69). Higher miRNA levels were associated with age and extracapsular extension while overexpression of miR-1246 was correlated significantly with increased tumor size, tumor grade, TNM staging, and depth of invasion. The analysis for target prediction unveiled a set of validated targets, among which were WNT5A, TP53INP1, STAT3, CTNNB1, PRKAR1A, and NFIB.

CONCLUSION

miR-155-5p and miR-1246 may be used as potential prognostic biomarkers in OSCC, with miR-1246 demonstrating superior diagnostic accuracy.

Hypertrophic cardiomyopathy in MYBPC3 carriers in aging

Hypertrophic cardiomyopathy (HCM) is characterized by abnormal thickening of the myocardium, leading to arrhythmias, heart failure, and elevated risk of sudden cardiac death, particularly among the young. This inherited disease is predominantly caused by mutations in sarcomeric genes, among which those in the cardiac myosin binding protein-C3 (MYBPC3) gene are major contributors. HCM associated with MYBPC3 mutations usually presents in the elderly and ranges from asymptomatic to symptomatic forms, affecting numerous cardiac functions and presenting significant health risks with a spectrum of clinical manifestations. Regulation of MYBPC3 expression involves various transcriptional and translational mechanisms, yet the destiny of mutant MYBPC3 mRNA and protein in late-onset HCM remains unclear. Pathogenesis related to MYBPC3 mutations includes nonsense-mediated decay, alternative splicing, and ubiquitin-proteasome system events, leading to allelic imbalance and haploinsufficiency. Aging further exacerbates the severity of HCM in carriers of MYBPC3 mutations. Advancements in high-throughput omics techniques have identified crucial molecular events and regulatory disruptions in cardiomyocytes expressing MYBPC3 variants. This review assesses the pathogenic mechanisms that promote late-onset HCM through the lens of transcriptional, post-transcriptional, and post-translational modulation of MYBPC3, underscoring its significance in HCM across carriers. The review also evaluates the influence of aging on these processes and MYBPC3 levels during HCM pathogenesis in the elderly. While pinpointing targets for novel medical interventions to conserve cardiac function remains challenging, the emergence of personalized omics offers promising avenues for future HCM treatments, particularly for late-onset cases.

Frailty, sex, and poverty are associated with DNA damage and repair in frail, middle-aged urban adults

Frailty is an age-related syndrome characterized by reduced recovery from stressors and increased risks of morbidity and mortality. Although frailty is usually studied in those over 65 years, our previous work showed that frailty is both present and a risk factor for premature mortality in midlife. We identified altered gene expression patterns and biological pathways associated with inflammation in frailty. Evidence suggests DNA oxidation damage related to inflammation accumulates with age, and that DNA repair capacity (DRC) declines with age and age-related conditions. We hypothesized that inter-individual differences in DNA oxidation damage and DRC are associated with frailty status and poverty level. Using the CometChip assay, we assessed baseline single-strand breaks and hydrogen peroxide (H2O2)-induced DNA oxidation damage and DRC in non-frail and frail middle-aged African American and White individuals with household incomes above and below poverty. Analysis of baseline single-strand breaks showed no associations with frailty, poverty, race, or sex. However, we identified an interaction between frailty and poverty in H2O2-induced DNA oxidation damage. We also identified interactions between sex and frailty as well as sex and poverty status with DRC. The social determinant of health, poverty, associates with DRC in men. Baseline DNA damage, H2O2-induced DNA damage as well as DRC were associated with serum cytokine levels. IL-10 levels were inversely associated with baseline DNA damage as well as H2O2-induced DNA damage, DRC was altered by IL-4 levels and sex, and by TNF-α levels in the context of sex and poverty status. This is the first evidence that DRC may be influenced by poverty status at midlife. Our data show that social determinants of health should be considered in examining biological pathways through which disparate age-related health outcomes become manifest.

Vascular Ageing: Mechanisms, Risk Factors, and Treatment Strategies

Ageing constitutes the biggest risk factor for poor health and adversely affects the integrity and function of all the cells, tissues, and organs in the human body. Vascular ageing, characterised by vascular stiffness, endothelial dysfunction, increased oxidative stress, chronic low-grade inflammation, and early-stage atherosclerosis, may trigger or exacerbate the development of age-related vascular diseases, which each year contribute to more than 3.8 million deaths in Europe alone and necessitate a better understanding of the mechanisms involved. To this end, a large number of recent preclinical and clinical studies have focused on the exponential accumulation of senescent cells in the vascular system and paid particular attention to the specific roles of senescence-associated secretory phenotype, proteostasis dysfunction, age-mediated modulation of certain microRNA (miRNAs), and the contribution of other major vascular risk factors, notably diabetes, hypertension, or smoking, to vascular ageing in the elderly. The data generated paved the way for the development of various senotherapeutic interventions, ranging from the application of synthetic or natural senolytics and senomorphics to attempt to modify lifestyle, control diet, and restrict calorie intake. However, specific guidelines, considering the severity and characteristics of vascular ageing, need to be established before widespread use of these agents. This review briefly discusses the molecular and cellular mechanisms of vascular ageing and summarises the efficacy of widely studied senotherapeutics in the context of vascular ageing.

Pathogenesis of miR-155 on nonmodifiable and modifiable risk factors in Alzheimer's disease

Alzheimer's disease (AD) is a common age-related neurodegenerative disease in the central nervous system and is the primary cause of dementia. It is clinically characterized by the memory impairment, aphasia, apraxia, agnosia, visuospatial and executive dysfunction, behavioral changes, and so on. Incidence of this disease was bound up with age, genetic factors, cardiovascular and cerebrovascular dysfunction, and other basic diseases, but the exact etiology has not been clarified. MicroRNAs (miRNAs) are small endogenous non-coding RNAs that were involved in the regulation of post-transcriptional gene expression. miRNAs have been extensively studied as noninvasive potential biomarkers for disease due to their relative stability in bodily fluids. In addition, they play a significant role in the physiological and pathological processes of various neurological disorders, including stroke, AD, and Parkinson's disease. MiR-155, as an important pro-inflammatory mediator of neuroinflammation, was reported to participate in the progression of β-amyloid peptide and tau via regulating immunity and inflammation. In this review, we put emphasis on the effects of miR-155 on AD and explore the underlying biological mechanisms which could provide a novel approach for diagnosis and treatment of AD.

The potential of using non-coding RNAs in forensic science applications

With the continuous development and integration of molecular biology and forensic science, non-coding RNAs (ncRNAs), especially ncRNAs with regulatory functions such as microRNA, long non-coding RNA, and circular RNA, have recently been actively explored by forensic scholars. In this study, we review the literature on these ncRNAs in various fields of forensic science, including postmortem interval determination, wound age estimation, forensic age assessment, cause of death analysis, and body fluid identification, aiming to evaluate the current research and provide a perspective for future applications.

miRNA expression in serum and PBMCs isolated from middle-aged and elderly patients during asthma exacerbation

microRNAs are short, noncoding RNA molecules involved in many inflammatory processes including bronchial asthma. Rhinoviruses are the main cause of acute asthma attack and may be involved in miRNA profile dysregulation. The aim of the study was to investigate the serum miRNA profile during asthma exacerbation in middle-aged and elderly patients. We also evaluated in this group in vitro response to rhinovirus 1b exposure. Seventeen middle-aged and elderly asthmatics were admitted to an outpatient clinic during asthma exacerbation and within a period of 6-8 weeks later. Blood samples were collected from the subjects and PBMCs were isolated. Cells were cultured in the presence of Rhinovirus 1b and with the medium only, and, after 48 h. miRNA expression (miRNA-19b, -106a, 126a, and -146a) isolated from serum and PBMCs (cultures) was evaluated with RT-PCR. Cytokines (INF-γ, TNF-α, IL6, and Il-10) in culture supernatants were evaluated with flow cytometry. On exacerbation visit patients demonstrated higher expression of serum miRNA-126a and -146a as compared to follow-up visit. There was a positive correlation between asthma control test results and miRNA-19, -126a, -146a. There was no other significant association between patient characteristics and the miRNA profile. Rhinovirus exposure did not changed miRNA expression in PBMCs as compared to medium on both visits. Cytokine production in culture supernatants significantly increased after rhinovirus infection. The group of middle-aged and elderly patients demonstrated changed levels serum miRNA during asthma exacerbation as compared to follow-up visit; however, correlations between their expression and clinical features were hardly noticeable. Rhinovirus did not affect expression of miRNA in PBMCs; yet, it induced cytokine production.

Characteristics of circulating small noncoding RNAs in plasma and serum during human aging

Objective

Aging is a complicated process that triggers age-related disease susceptibility through intercellular communication in the microenvironment. While the classic secretome of senescence-associated secretory phenotype (SASP) including soluble factors, growth factors, and extracellular matrix remodeling enzymes are known to impact tissue homeostasis during the aging process, the effects of novel SASP components, extracellular small noncoding RNAs (sncRNAs), on human aging are not well established.

Methods

Here, by utilizing 446 small RNA-seq samples from plasma and serum of healthy donors found in the Extracellular RNA (exRNA) Atlas data repository, we correlated linear and nonlinear features between circulating sncRNAs expression and age by the maximal information coefficient (MIC) relationship determination. Age predictors were generated by ensemble machine learning methods (Adaptive Boosting, Gradient Boosting, and Random Forest) and core age-related sncRNAs were determined through weighted coefficients in machine learning models. Functional investigation was performed via target prediction of age-related miRNAs.

Results

We observed the number of highly expressed transfer RNAs (tRNAs) and microRNAs (miRNAs) showed positive and negative associations with age respectively. Two-variable (sncRNA expression and individual age) relationships were detected by MIC and sncRNAs-based age predictors were established, resulting in a forecast performance where all R ² values were greater than 0.96 and root-mean-square errors (RMSE) were less than 3.7 years in three ensemble machine learning methods. Furthermore, important age-related sncRNAs were identified based on modeling and the biological pathways of age-related miRNAs were characterized by their predicted targets, including multiple pathways in intercellular communication, cancer and immune regulation.

Conclusion

In summary, this study provides valuable insights into circulating sncRNAs expression dynamics during human aging and may lead to advanced understanding of age-related sncRNAs functions with further elucidation.

Experimental Autoimmune Encephalomyelitis of Mice: IgGs from the Sera of Mice Hydrolyze miRNAs

It was shown that the spontaneous development of experimental encephalomyelitis (EAE) in C57BL/6 mice occurs due to changes in the profile of bone marrow stem cells differentiation. This leads to the appearance of lymphocytes producing antibodies-abzymes that hydrolyze DNA, myelin basic protein (MBP), and histones. The activity of abzymes in the hydrolysis of these auto-antigens slowly but constantly increases during the spontaneous development of EAE. Treatment of mice with myelin oligodendrocyte glycoprotein (MOG) leads to a sharp increase in the activity of these abzymes with their maximum at 20 days (acute phase) after immunization. In this work, we analyzed changes in the activity of IgG-abzymes hydrolyzing (pA)₂₃, (pC)₂₃, (pU)₂₃, and six miRNAs (miR-9-5p, miR-219a-5p, miR-326, miR-155-5p, miR-21-3p, and miR-146a-3p) before and after mice immunization with MOG. Unlike abzymes hydrolyzing DNA, MBP, and histones, the spontaneous development of EAE leads not to an increase but to a permanent decrease of IgGs activity of hydrolysis of RNA-substrates. Treatment of mice with MOG resulted in a sharp but transient increase in the activity of antibodies by day 7 (onset of the disease), followed by a sharp decrease in activity 20-40 days after immunization. A significant difference in the production of abzymes against DNA, MBP, and histones before and after mice immunization with MOG with those against RNAs may be since the expression of many miRNAs decreased with age. This can lead to a decrease in the production of antibodies and abzymes that hydrolyze miRNAs with age mice.

The role of microRNA-485 in neurodegenerative diseases

Neurodegenerative diseases (NDDs) are age-related disorders characterized by progressive neurodegeneration and neuronal cell loss in the central nervous system. Neuropathological conditions such as the accumulation of misfolded proteins can cause neuroinflammation, apoptosis, and synaptic dysfunction in the brain, leading to the development of NDDs including Alzheimer's disease (AD) and Parkinson's disease (PD). MicroRNAs (miRNAs) are small noncoding RNA molecules that regulate gene expression post-transcriptionally via RNA interference. Recently, some studies have reported that some miRNAs play an important role in the development of NDDs by regulating target gene expression. MiRNA-485 (miR-485) is a highly conserved brain-enriched miRNA. Accumulating clinical reports suggest that dysregulated miR-485 may be involved in the pathogenesis of AD and PD. Emerging studies have also shown that miR-485 plays a novel role in the regulation of neuroinflammation, apoptosis, and synaptic function in the pathogenesis of NDDs. In this review, we introduce the biological characteristics of miR-485, provide clinical evidence of the dysregulated miR-485 in NDDs, novel roles of miR-485 in neuropathological events, and discuss the potential of targeting miR-485 as a diagnostic and therapeutic marker for NDDs.

Obtaining miRNA from Saliva-Comparison of Sampling and Purification Methods

The use of saliva as a biomarker source has advantages over other biofluids and imaging techniques, and miRNAs are ideal biomarker candidates. They are involved in numerous cellular processes, and their altered expression suggests that miRNAs play a crucial regulatory role in disease development. We wanted to find an easily reproducible and executable miRNA-obtaining methodology suitable for quantification. Three commercial miRNA extraction kits (mirVana, Nucleospin and miRNeasy) and three saliva collectors (50 mL tubes, Salimetrics and Oragene) were tested. Several features, including RNA quality and technical parameters, were evaluated. The expression of five synthetic spike-in controls and seven saliva-miRNAs was analyzed independently and grouped by the collectors and the extraction kits. The combination of Oragene and miRNeasy assured the most sensitive detection of all seven saliva miRNAs. Testing different combinations of saliva collectors and RNA purification kits permitted the establishment of combinations for different uses. The results of our study highlight that optimization of resources for biomarker studies is possible after careful planning of each study.

MicroRNA 200a as a histologically independent marker for meningioma recurrence: Results of a four microRNA panel analysis in meningiomas

INTRODUCTION

Meningiomas are mostly benign neoplasms of the central nervous system. Nevertheless there are recurrences in about 20% after surgical resection. Previous studies could reveal several predictors of meningioma recurrence. Tumor progression often is associated with a specific pattern of chromosome losses. Our study investigated the potential function of selected microRNAs as markers of tumor progression.

METHODS

By real-time polymerase chain reaction the expressions of microRNA 21-3p, 34a-3p, 200a-3p, and 409-3p were analyzed in solid tumor and in blood samples of 51 meningioma patients as well as in blood samples of 20 healthy individuals. Additionally, aberrations of parts of chromosomes 1, 14, 18, and 22 were analyzed by FISH. Tumor and blood samples were statistically analyzed, using Spearman's rank correlation coefficient as well as Mann-Whitney U- and Kruskal-Wallis-Test.

RESULTS

MicroRNA 200a showed significantly lower expressions in recurrent meningiomas than in newly diagnosed ones. MicroRNA 409 in meningiomas was correlated significantly with tumor volume and showed a significant negative correlation with patient age. Significance was found between the expression patterns of microRNAs 34a and 200a with the respective aberrations of chromosome 1p and the microRNA 409 with aberration of chromosome 14. In the male cohort the expression of microRNA 200a in blood was significantly upregulated in patients compared to healthy volunteers. By our research the function of microRNA 200a was proved to detect meningioma patients by liquid biopsy.

CONCLUSION

We detected microRNA 200a as a new biomarker to indicate meningioma recurrences. Future transferability to blood could be important for patient follow-up.

A blast from the past: To tame time with metformin

The strong evidence of metformin use in subjects affected by type 2 diabetes (T2DM) on health outcomes, together with data from pre-clinical studies, has led the gerontological research to study the therapeutic potential of such a drug as a slow-aging strategy. However, despite clinical use for over fifty years as an anti-diabetic drug, the mechanisms of action beyond glycemic control remain unclear. In this review, we have deeply examined the literature, doing a narrative review from the metformin story, through mechanisms of action to slow down aging potential, from lower organisms to humans. Based on the available evidence, we conclude that metformin, as shown in lower organisms and mice, may be effective in humans' longevity. A complete analysis and follow-up of ongoing clinical trials may provide more definitive answers as to whether metformin should be promoted beyond its use to treat T2DM as a drug that enhances both healthspan and lifespan.

Biological Age Predictors: The Status Quo and Future Trends

There is no single universal biomarker yet to estimate overall health status and longevity prospects. Moreover, a consensual approach to the very concept of aging and the means of its assessment are yet to be developed. Markers of aging could facilitate effective health control, more accurate life expectancy estimates, and improved health and quality of life. Clinicians routinely use several indicators that could be biomarkers of aging. Duly validated in a large cohort, models based on a combination of these markers could provide a highly accurate assessment of biological age and the pace of aging. Biological aging is a complex characteristic of chronological age (usually), health-to-age concordance, and medically estimated life expectancy. This study is a review of the most promising techniques that could soon be used in routine clinical practice. Two main selection criteria were applied: a sufficient sample size and reliability based on validation. The selected biological age calculators were grouped according to the type of biomarker used: (1) standard clinical and laboratory markers; (2) molecular markers; and (3) epigenetic markers. The most accurate were the calculators, which factored in a variety of biomarkers. Despite their demonstrated effectiveness, most of them require further improvement and cannot yet be considered for use in standard clinical practice. To illustrate their clinical application, we reviewed their use during the COVID-19 pandemic.

MicroRNA biomarkers in frontotemporal dementia and to distinguish from Alzheimer's disease and amyotrophic lateral sclerosis

Frontotemporal lobar degeneration describes a group of progressive brain disorders that primarily are associated with atrophy of the prefrontal and anterior temporal lobes. Frontotemporal lobar degeneration is considered to be equivalent to frontotemporal dementia. Frontotemporal dementia is characterized by progressive impairments in behavior, executive function, and language. There are two main clinical subtypes: behavioral-variant frontotemporal dementia and primary progressive aphasia. The early diagnosis of frontotemporal dementia is critical for developing management strategies and interventions for these patients. Without validated biomarkers, the clinical diagnosis depends on recognizing all the core or necessary neuropsychiatric features, but misdiagnosis often occurs due to overlap with a range of neurologic and psychiatric disorders. In the studies reviewed a very large number of microRNAs were found to be dysregulated but with limited overlap between individual studies. Measurement of specific miRNAs singly or in combination, or as miRNA pairs (as a ratio) in blood plasma, serum, or cerebrospinal fluid enabled frontotemporal dementia to be discriminated from healthy controls, Alzheimer's disease, and amyotrophic lateral sclerosis. Furthermore, upregulation of miR-223-3p and downregulation of miR-15a-5p, which occurred both in blood serum and cerebrospinal fluid, distinguished behavioral-variant frontotemporal dementia from healthy controls. Downregulation of miR-132-3p in frontal and temporal cortical tissue distinguished frontotemporal lobar degeneration and frontotemporal dementia, respectively, from healthy controls. Possible strong miRNA biofluid biomarker contenders for behavioral-variant frontotemporal dementia are miR-223-3p, miR-15a-5p, miR-22-3p in blood serum and cerebrospinal fluid, and miR-124 in cerebrospinal fluid. No miRNAs were identified able to distinguish between behavioral-variant frontotemporal dementia and primary progressive aphasia subtypes. Further studies are warranted on investigating miRNA expression in biofluids and frontal/temporal cortical tissue to validate and extend these findings.

Tackling cellular senescence by targeting miRNAs

Cellular senescence, which is characterized by permanent proliferation arrest, has become an important target for the amelioration of various human diseases. The activity of senescent cells is mainly related to the senescence-associated secretory phenotype (SASP). The SASP can cause chronic inflammation in local tissues and organs through autocrine and paracrine mechanisms, and a series of factors secreted by senescent cells can deteriorate the cellular microenvironment, promoting tumor formation and exacerbating aging-related diseases. Therefore, avoiding the promotion of cancer is an urgent problem. In recent years, increased attention has been given to the mechanistic study of microRNAs in senescence. As important posttranscriptional regulators, microRNAs possess unique tissue-specific expression in senescence. MicroRNAs can regulate the SASP by regulating proteins in the senescence signaling pathway, the reverse transcriptase activity of telomerase, the generation of reactive oxygen species and oxidative damage to mitochondria. Numerous studies have confirmed that removing senescent cells does not cause significant side effects, which also opens the door to the development of treatment modalities against senescent cells. Herein, this review discusses the double-edged sword of cellular senescence in tumors and aging-related diseases and emphasizes the roles of microRNAs in regulating the SASP, especially the potential of microRNAs to be used as therapeutic targets to inhibit senescence, giving rise to novel therapeutic approaches for the treatment of aging-associated diseases.

Systemic Listeria monocytogenes infection in aged mice induces long-term neuroinflammation: the role of miR-155

BACKGROUND

Understanding mechanisms of pathologic neuroinflammation is essential for improving outcomes after central nervous system infections. Brain tissue-resident memory T cells (bT_RM) are recruited during central nervous system infection and promote pathogen control as well as noxious inflammation. Our prior studies in young mice showed optimal recruitment of CD8⁺ bT_RM during neuroinvasive Listeria monocytogenes (Lm) infection required miR-155, and was significantly inhibited by anti-miR-155 oligonucleotides. Since Lm is an important pathogen in the elderly, we hypothesized anti-miR-155 would also inhibit accumulation of CD8⁺ bT_RM in aged mice infected with Lm.

METHODS

Young (2 mo) and aged (> 18 mo) male C57BL/6 mice were infected intra-peritoneally with wild-type Lm, or avirulent Lm mutants lacking the genes required for intracellular motility (ΔactA) or phagosomal escape (Δhly), then were given antibiotics. Brain leukocytes and their intracellular cytokine production were quantified by flow cytometry >28d post-infection (p.i.). The role of miR-155 was tested by injecting mice with anti-miR-155 or control oligonucleotides along with antibiotics.

RESULTS

Aged mice had significantly more homeostatic CD8⁺ bT_RM than did young mice, which did not increase after infection with wild-type Lm despite 50% mortality, whereas young mice suffered no mortality after a larger inoculum. For direct comparison of post-infectious neuroinflammation after the same inoculum, young and aged mice were infected with 10⁷ CFU ΔactA Lm. This mutant caused no mortality and significantly increased CD8⁺ bT_RM 28d p.i. in both groups, whereas bone marrow-derived myeloid cells, particularly neutrophils, increased only in aged mice. Notably, anti-miR-155 reduced accumulation of brain myeloid cells in aged mice after infection, whereas CD8⁺ bT_RM were unaffected.

CONCLUSIONS

Systemic infection with Lm ΔactA is a novel model for studying infection-induced brain inflammation in aged mice without excessive mortality. CD8⁺ bT_RM increase in both young and aged mice after infection, whereas only in aged mice bone marrow-derived myeloid cells increase long-term. In aged mice, anti-miR-155 inhibits brain accumulation of myeloid cells, but not CD8⁺ bT_RM. These results suggest young and aged mice differ in manifestations and mechanisms of infection-induced neuroinflammation and give insight for developing therapies to ameliorate brain inflammation following severe infection in the elderly.

Noncoding RNAs in age-related cardiovascular diseases

Cardiovascular diseases (CVDs) are the leading cause of morbidity and mortality in the adult population worldwide and represent a severe economic burden and public health concern. The majority of human genes do not code for proteins. However, noncoding transcripts play important roles in ageing that significantly increases the risk for CVDs. Noncoding RNAs (ncRNAs) are critical regulators of multiple biological processes related to ageing such as oxidative stress, mitochondrial dysfunction and chronic inflammation. NcRNAs are also involved in pathophysiological developments within the cardiovascular system including arrhythmias, cardiac hypertrophy, fibrosis, myocardial infarction and heart failure. In this review article, we cover the roles of ncRNAs in cardiovascular ageing and disease as well as their potential therapeutic applications in CVDs.

The Role of MicroRNAs in Endothelial Cell Senescence

Cellular senescence is a complex, dynamic process consisting of the irreversible arrest of growth and gradual deterioration of cellular function. Endothelial senescence affects the cell’s ability to repair itself, which is essential for maintaining vascular integrity and leads to the development of endothelial dysfunction, which has an important role in the pathogenesis of cardiovascular diseases. Senescent endothelial cells develop a particular, senescence-associated secretory phenotype (SASP) that detrimentally affects both surrounding and distant endothelial cells, thereby facilitating the ageing process and development of age-related disorders. Recent studies highlight the role of endothelial senescence and its dysfunction in the pathophysiology of several age-related diseases. MicroRNAs are small noncoding RNAs that have an important role in the regulation of gene expression at the posttranscriptional level. Recently, it has been discovered that miRNAs could importantly contribute to endothelial cell senescence. Overall, the research focus has been shifting to new potential mechanisms and targets to understand and prevent the structural and functional changes in ageing senescent endothelial cells in order to prevent the development and limit the progression of the wide spectrum of age-related diseases. The aim of this review is to provide some insight into the most important pathways involved in the modulation of endothelial senescence and to reveal the specific roles of several miRNAs involved in this complex process. Better understanding of miRNA’s role in endothelial senescence could lead to new approaches for prevention and possibly also for the treatment of endothelial cells ageing and associated age-related diseases.

Molecular Mechanisms of Immunosenescene and Inflammaging: Relevance to the Immunopathogenesis and Treatment of Multiple Sclerosis

Aging is characterized, amongst other features, by a complex process of cellular senescence involving both innate and adaptive immunity, called immunosenescence and associated to inflammaging, a low-grade chronic inflammation. Both processes fuel each other and partially explain increasing incidence of cancers, infections, age-related autoimmunity, and vascular disease as well as a reduced response to vaccination. Multiple sclerosis (MS) is a lifelong disease, for which considerable progress in disease-modifying therapies (DMTs) and management has improved long-term survival. However, disability progression, increasing with age and disease duration, remains. Neurologists are now involved in caring for elderly MS patients, with increasing comorbidities. Aging of the immune system therefore has relevant implications for MS pathogenesis, response to DMTs and the risks mediated by these treatments. We propose to review current evidence regarding markers and molecular mechanisms of immunosenescence and their relevance to understanding MS pathogenesis. We will focus on age-related changes in the innate and adaptive immune system in MS and other auto-immune diseases, such as systemic lupus erythematosus and rheumatoid arthritis. The consequences of these immune changes on MS pathology, in interaction with the intrinsic aging process of central nervous system resident cells will be discussed. Finally, the impact of immunosenescence on disease evolution and on the safety and efficacy of current DMTs will be presented.

Expression of miRNA-25 in young and old lung adenocarcinoma

Background:

An appropriate personalized molecular testing ensures the most efficacious treatment in lung cancer. It is still controversial whether younger lung adenocarcinoma (LUAD) patients have different molecular features compared with their older counterparts. MicroRNAs have been involved in lung cancer and their altered expression has been suggested as a potential biomarker in the pathogenesis, diagnosis, prognosis, and therapy of LUAD.

Materials and Methods:

To analyze putative differences in miR-25 expression between young (with age ≤50 years) and old adenocarcinoma patients, we quantified miR-25 levels with NanoString technology in 88 LUAD specimens. We further investigated a cohort of 309 LUAD patients from the cancer genome atlas (TCGA) database to test our hypothesis.

Results:

miR-25 expression was upregulated in young LUAD patients in comparison to the older ones (P = 0.03) in our series. The analysis of public database TCGA confirmed our results, which miR-25 differentially expressed in the two aged groups (P = 0.0009). Moreover, a consequential pairing of miR-25 with a target region in phosphatase and tensin homolog (PTEN) 3’ untranslated region (UTR) and actually low PTEN expression seemed to be associated with high miR-25 (P = 0.001) in young patients.

Conclusions:

The interaction of miR-25 and PTEN in young LUAD may define a subgroup of patients, highlighting the concept of molecular testing in different age subtypes.

miR-29cb2 promotes angiogenesis and osteogenesis by inhibiting HIF-3α in bone

Coordination between osteogenesis and angiogenesis is required for bone homeostasis. Here, we show that miR-29cb2 is a bone-specific miRNA and plays critical roles on angiogenesis-osteogenesis coupling during bone remodeling. Mice with deletion of miR-29cb2 exhibit osteopenic phenotypes and osteoblast impairment, accompanied by pronounced decreases in specific H vessels. The decrease in bone miR-29cb2 was associated with pathological ovariectomy stimuli. Mechanistically, hypoxia-inducible factor (HIF)-3α, as a target for miR-29cb2, inhibits HIF-1α activity by competitively bonding with HIF-1β. Notably, miR-29cb2 in peripheral blood (PB) nearly is undetectable in sham and significantly increases in ovariectomy mice. Further evaluation from osteoporosis patients demonstrates similar signatures. ROC analysis shows miR-29cb2 in PB has higher sensitivity and specificity for diagnosing osteoporosis when compared with four clinical biomarkers. Collectively, these findings reveal that miR-29cb2 is essential for bone remodeling by inhibiting HIF-3α and elevated bone-specific miR-29cb2 in PB, which may be a promising biomarker for bone loss.

miR-548j-5p regulates angiogenesis in peripheral artery disease

Peripheral artery disease (PAD) is a vascular disease involving diffuse atherosclerosis, and is associated with increased cardiovascular mortality and morbidity. Critical limb ischemia (CLI) is the most severe complication of PAD. In addition to medical and interventional treatment, therapeutic angiogenesis is a novel therapy for PAD. Circulating microRNAs (miRNAs) are considered key regulators of gene expression, but their role in ischemic-induced angiogenesis is poorly-characterized. There is currently a limited understanding of the specific miRNAs associated with PAD. To determine the regulation of miRNAs, we obtained miRNA profiles using RNA isolated from patients with PAD and a control group. The effects of specific miRNAs on angiogenesis were evaluated by assessing the in vitro angiogenic function of endothelial progenitor cells (EPCs), performing an in vivo angiogenesis assay, and employing a mouse hindlimb ischemic model. Our results demonstrated that circulating miR-548j-5p was significantly reduced in patients with PAD as compared with the controls. miR-548j-5p promoted EPC angiogenesis by enhancing migration and tube formation. The endothelial nitric oxide synthase (NOS) and stromal cell-derived factor (SDF)-1 signaling pathways appeared to be potential targets of miR-548j-5p. Furthermore, the results of a directed in vivo angiogenesis assay of EPCs and a hindlimb ischemia mouse model demonstrated that miR-548j-5p enhanced the capillary density and blood flow recovery in hindlimb ischemia. In conclusion, our data indicated that up-regulation of miR-548j-5p promotes angiogenesis in ischemic tissue and may represent a novel therapeutic approach for PAD.

Extracellular vesicle microRNAs in celiac disease patients under a gluten-free diet, and in lactose intolerant individuals

BACKGROUND

Celiac disease (CD) is an autoimmune disorder triggered by an abnormal immunological response to gluten ingestion and is associated with deregulated expression of cellular microRNAs (miRNAs) of the gut mucosa. It is frequently misdiagnosed as lactose intolerance (LI) due to symptom resemblance. Microvilli loss may be counteracted by a rigorous gluten-free diet (GFD).

AIMS

To identify altered extracellular vesicle miRNAs from plasma among CD patients on GFD (n=34), lactose intolerant individuals on restrictive diet (n=14) and controls (n=23), and to predict biological pathways in which these altered miRNAs may play a part.

METHODS

Five different small RNA samples of each group were pooled twice and then screened by new-generation sequencing. Four miRNAs were selected to be quantified by RT-qPCR in the entire sample.

RESULTS

The levels of four miRNAs - miR-99b-3p, miR-197-3p, miR-223-3p, and miR-374b-5p - differed between CD patients and controls (P<0.05). Apart from miR-223-3p, all these miRNAs tended to have altered levels also between LI and controls (P<0.10). The results for miR-99b-3p and miR-197-3p between CD and controls were confirmed by RT-qPCR, which also indicated different levels of miR-99b-3p and miR-374b-5p between CD-associated LI and LI (P<0.05).

CONCLUSIONS

These miRNAs may have targets that affect cell death, cell communication, adhesion, and inflammation modulation pathways. Hence, altered miRNA levels could be associated with CD-related aspects and gut mucosa recovery.

Integrated Multi-Omics for Novel Aging Biomarkers and Antiaging Targets

Aging is closely related to the occurrence of human diseases; however, its exact biological mechanism is unclear. Advancements in high-throughput technology provide new opportunities for omics research to understand the pathological process of various complex human diseases. However, single-omics technologies only provide limited insights into the biological mechanisms of diseases. DNA, RNA, protein, metabolites, and microorganisms usually play complementary roles and perform certain biological functions together. In this review, we summarize multi-omics methods based on the most relevant biomarkers in single-omics to better understand molecular functions and disease causes. The integration of multi-omics technologies can systematically reveal the interactions among aging molecules from a multidimensional perspective. Our review provides new insights regarding the discovery of aging biomarkers, mechanism of aging, and identification of novel antiaging targets. Overall, data from genomics, transcriptomics, proteomics, metabolomics, integromics, microbiomics, and systems biology contribute to the identification of new candidate biomarkers for aging and novel targets for antiaging interventions.

miRNAs as Therapeutic Tools in Alzheimer's Disease

Alzheimer’s disease (AD), an age-dependent, progressive neurodegenerative disorder, is the most common type of dementia, accounting for 50–70% of all dementia cases. Due to the increasing incidence and corresponding socioeconomic burden of dementia, it has rapidly emerged as a challenge to public health worldwide. The characteristics of AD include the development of extracellular amyloid-beta plaques and intracellular neurofibrillary tangles, vascular changes, neuronal inflammation, and progressive brain atrophy. However, the complexity of the biology of AD has hindered progress in elucidating the underlying pathophysiological mechanisms of AD, and the development of effective treatments. MicroRNAs (miRNAs, which are endogenous, noncoding RNAs of approximately 22 nucleotides that function as posttranscriptional regulators of various genes) are attracting attention as powerful tools for studying the mechanisms of diseases, as they are involved in several biological processes and diseases, including AD. AD is a multifactorial disease, and several reports have suggested that miRNAs play an important role in the pathological processes of AD. In this review, the basic biology of miRNAs is described, and the function and physiology of miRNAs in the pathological processes of AD are highlighted. In addition, the limitations of current pharmaceutical therapies for the treatment of AD and the development of miRNA-based next-generation therapies are discussed.

Identification and Characterization of Circulating MicroRNAs as Novel Biomarkers in Dogs With Heart Diseases

Background: Previous studies in humans have confirmed dysregulations of circulating microRNAs (miRNAs) in patients with various cardiovascular diseases. However, studies on circulating miRNAs in dogs with various heart diseases are limited in number. This study aimed to identify significantly dysregulated circulating miRNAs and characterize them as novel biomarkers in dogs with heart diseases. Materials and Methods: Circulating levels of 11 miRNAs were investigated in serum samples of 82 dogs (72 with heart diseases and 10 healthy dogs) using quantitative reverse transcription-polymerase chain reaction. The results were correlated to clinical data including echocardiographic results and N-terminal pro B-type natriuretic peptide (NT-proBNP) levels. Results: Upregulation of cfa-miR-130b was observed in dogs with myxomatous mitral valve degeneration (MMVD) stage B, patent ductus arteriosus, and pulmonic stenosis. In dogs with MMVD stage B, cfa-miR-130b was upregulated and correlated with clinical indices. In receiver operating characteristic (ROC) analysis, cfa-miR-130b accurately distinguished dogs with diseases from healthy dogs. We also observed that cfa-miR-375 and cfa-let-7b were upregulated in dogs with concentric cardiac hypertrophy. The cfa-miR-375 was correlated with concentric hypertrophy indices and was an accurate indicator of concentric hypertrophy in ROC analysis. Conclusions: The miRNAs identified in this study may be used as novel biomarkers and possible candidates for therapeutic targets in various canine heart diseases.

Centenarians as models of healthy aging: Example of REST

Centenarians are a group of individuals exhibiting extreme longevity, who are characterized by a remarkable compression of morbidity. Therefore, centenarians have been postulated as a model of healthy aging. Different approaches have been used to decipher the biology and genetics of centenarians in order to identify key anti-aging pathways. The majority of studies have taken advantage of blood samples to perform their analysis. Besides, a recent study in human brain samples deciphered the transcription factor REST (Repressor Element-1 Silencing Transcription Factor) as an important player of extreme longevity and cognitive activity. This study goes from human to animal models and revealed that REST acts as an epigenetic regulator of neuronal homeostasis, to control aging and longevity. The aim of this view point is to summarize recent literature describing genetic and epigenetic factors, as well as molecular pathways associated with centenarians and the biology of aging. We will pay particular attention to the impact of REST in centenarians and longevity.

miR-496 inhibits proliferation via LYN and AKT pathway in gastric cancer

MicroRNAs (miRNAs) operate as tumor suppressor or carcinogen to regulate cell proliferation, metastasis, invasion, differentiation, apoptosis, and metabolic process. In the present research, we investigated the effect and mechanism of miR-496 in human gastric cancer cells. miR-496 was downregulated in two gastric cancer cell lines, AGS and MKN45, compared with normal gastric epithelial cell line GES-1. miR-496 mimics inhibited the proliferation of AGS cells after the transfection for 48 and 72 h. The migration and invasion of AGS cells were also inhibited by the transfection of miR-496 mimics. miR-496 mimics induced the apoptosis through upregulating the levels of Bax and Active Caspase 3 and downregulating the levels of Bcl-2 and Total Caspase 3. Bioinformatics analysis showed that there was a binding site between miR-496 and Lyn kinase (LYN). miR-496 mimics could inhibit the expression of LYN in AGS cells. LYN overexpression blocked the inhibition of tumor cell growth, as well as the inhibition of AKT/mTOR signaling pathway induced by miR-496. In conclusion, miR-496 inhibited the proliferation through the AKT/mTOR signaling pathway via targeting LYN in gastric cancer cells. Our research provides a new potential target for clinical diagnosis and targeted treatment for gastric cancer.

Exosomes and Micro-RNAs in Aging Process

Exosomes are the main actors of intercellular communications and have gained great interest in the new cell-free regenerative medicine. These nanoparticles are secreted by almost all cell types and contain lipids, cytokines, growth factors, messenger RNA, and different non-coding RNA, especially micro-RNAs (mi-RNAs). Exosomes' cargo is released in the neighboring microenvironment but is also expected to act on distant tissues or organs. Different biological processes such as cell development, growth and repair, senescence, migration, immunomodulation, and aging, among others, are mediated by exosomes and principally exosome-derived mi-RNAs. Moreover, their therapeutic potential has been proved and reinforced by their use as biomarkers for disease diagnostics and progression. Evidence has increasingly shown that exosome-derived mi-RNAs are key regulators of age-related diseases, and their involvement in longevity is becoming a promising issue. For instance, mi-RNAs such as mi-RNA-21, mi-RNA-29, and mi-RNA-34 modulate tissue functionality and regeneration by targeting different tissues and involving different pathways but might also interfere with long life expectancy. Human mi-RNAs profiling is effectively related to the biological fluids that are reported differently between young and old individuals. However, their underlying mechanisms modulating cell senescence and aging are still not fully understood, and little was reported on the involvement of mi-RNAs in cell or tissue longevity. In this review, we summarize exosome biogenesis and mi-RNA synthesis and loading mechanism into exosomes' cargo. Additionally, we highlight the molecular mechanisms of exosomes and exosome-derived mi-RNA regulation in the different aging processes.

Circulating miRNA expression in asthmatics is age-related and associated with clinical asthma parameters, respiratory function and systemic inflammation

Background

The course of asthma may differ between elderly asthmatics (EA) and non-elderly asthmatics (nEA), which may be partially associated with an age-dependent aberrant immune response. The aim of the study was to determine the influence of serum miRNA expression on asthma characteristics and systemic inflammation markers in EA and nEA.

Methods

Control and severity of asthma, pulmonary function and FeNO were assessed in 28 EA and 31 nEA patients. The control group included 59 elderly and non-elderly healthy individuals. The expression of selected miRNAs in serum was measured with rt-PCR, and proinflammatory cytokine activity was assayed by ELISA or flow cytometry.

Results

No difference in serum miRNA expression was observed between the asthmatics and healthy controls. EA demonstrated lower expression of miRNA-106a and miRNA-126a than nEA (p = 0.003 and p = 0.02) and EC had lower expression of miRNA-146a, -126a, -106a and 19b than nEC (p = 0.001, p = 0.003, p = 0.005 and p < 0.001 respectively). Only nEA demonstrated a relationship between the expression of selected miRNAs and the level of asthma control (assessed with ACT) and with airway inflammation, measured by FeNO level. All patients with asthma demonstrated elevated TNFα, IL-6 and sTNF RI levels compared to controls (p = 0.026, p = 0.03 and p < 0.001 respectively). EA demonstrated a higher TNFα level than EC (p < 0.001), and EA had a higher level of sTNF RI than nEA (p < 0.001). A significant correlation was observed between serum levels of proinflammatory cytokines and selected miRNAs.

Conclusion

Serum miRNA expression was found to correlate with clinical characteristics of asthma and systemic inflammation in an age-dependent fashion, suggesting that miRNA may differentially contribute to asthma pathogenesis in elderly and non-elderly patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01769-x.

Ranking Biomarkers of Aging by Citation Profiling and Effort Scoring

Aging affects most living organisms and includes the processes that reduce health and survival. The chronological and the biological age of individuals can differ remarkably, and there is a lack of reliable biomarkers to monitor the consequences of aging. In this review we give an overview of commonly mentioned and frequently used potential aging-related biomarkers. We were interested in biomarkers of aging in general and in biomarkers related to cellular senescence in particular. To answer the question whether a biological feature is relevant as a potential biomarker of aging or senescence in the scientific community we used the PICO strategy known from evidence-based medicine. We introduced two scoring systems, aimed at reflecting biomarker relevance and measurement effort, which can be used to support study designs in both clinical and research settings.

Voluntary wheel-running exercise attenuates brain aging of rats through activating miR-130a-mediated autophagy

Autophagy is a highly regulated intracellular process for the degradation of protein aggregates and damaged organelles. Recently, autophagy has been implicated in Alzheimer's disease (AD) and aging. Autophagy process is regulated by the recruitment and assembly of several autophagy-related genes (Atgs) such as, Atg7 and LC3, as the highly conserved and important markers involved in the regulation of autophagy. We recently reported the reduced LC3-II/LC3-I ratio, down-regulated ATG7, and increased p62 protein levels in hippocampal tissues of aging rats. MicroRNA-130a (miR-130a) plays a crucial role in physiological and pathological processes, but whether miR-130a affects the autophagy of brain is unknown. We aim to explore the regulatory role of miR-130a on the autophagy and cell senescence of SH-SY5Y, as well as LC3-II/LC3-I ratio, and the expression of p62, ATG7, Ac-p53 and p21 during exercise intervention of aging rats. In this study, miR-130a expression was markedly down-regulated in the hippocampal of aged rats companying with up-regulated expression of Ac-p53 and p21 when compared with young rats. In contrast, voluntary wheel running could up-regulate miR-130a expression; decrease the expression of Ac-p53 and p21 in aging rats. Interestingly, exercise reversed the impaired autophagy resulted from aging possibly by activating AMPK signaling. Moreover, overexpression of miR-130a in d-galactose (D-gal)-induced SH-SY5Y cell senescence model attenuated d-gal-induced impaired autophagy and cell senescence, demonstrated by decreased levels of LC3, Ac-p53, p21 and increased p62, suggesting that voluntary wheel running can alleviate brain aging in natural aging rats by up-regulating miR-130a-mediated autophagy.

A ride through the epigenetic landscape: aging reversal by reprogramming

Aging has become one of the fastest-growing research topics in biology. However, exactly how the aging process occurs remains unknown. Epigenetics plays a significant role, and several epigenetic interventions can modulate lifespan. This review will explore the interplay between epigenetics and aging, and how epigenetic reprogramming can be harnessed for age reversal. In vivo partial reprogramming holds great promise as a possible therapy, but several limitations remain. Rejuvenation by reprogramming is a young but rapidly expanding subfield in the biology of aging.

Changes in the MicroRNA Profile of the Giant Panda After Canine Distemper Vaccination and the Integrated Analysis of MicroRNA-Messenger RNA

Canine distemper (CD) is a significant threat to wild and captive giant panda populations. Captive giant pandas are inoculated with canine distemper virus (CDV) vaccination to prevent the infection with the CDV. As an important regulator, microRNA (miRNA) plays a crucial role in regulating gene expression, including in disease immunity. To understand the role of miRNA in immune response to CDV vaccination, we investigated the miRNA expression profile in five giant panda cubs after two inoculations, 21 days apart. A total of 187 conserved miRNAs and 96 novel miRNAs were identified. Among the 187 conserved miRNAs, 29 differentially expressed miRNAs were found postinoculation. The upregulation of miR-16, miR-182, miR-30b, and miR-101 indicated that the innate immune may be enhanced, whereas the upregulation of miR-142 and miR-19a are probably involved in the enhanced cellular immune response. However, the downregulated miR-155 and miR-181a might indicate the giant panda has weak ability to produce antibodies and memory B cells. Integrated analysis of miRNA-messenger RNA (mRNA) found 20 negatively regulated miRNA-mRNA pairs, where downregulated miR-204 might enhance giant panda cub innate immunity by increasing TLR6 expression, and downregulated miR-330 might activate macrophages and regulate the immune response by increasing TMEM106A expression. Our research provides key information for future development to enhance the immune response of giant pandas and potentially improve the survival of captive and wild giant panda populations threatened by CD.

miR-221-3p regulates apoptosis of ovarian granulosa cells via targeting FOXO1 in older women with diminished ovarian reserve (DOR)

In our earlier study, we showed that the expression of microRNA‐221‐3p (miR‐221‐3p) was significantly lower in women of advanced age with diminished ovarian reserve (DOR) compared with young women with normal ovarian reserve (NOR). Therefore, in this study, we aimed to explore how miR‐221‐3p regulates apoptosis of granulosa cells and the pathogenesis of DOR. Bioinformatics prediction and dual‐luciferase reporter assay were conducted to identify the target gene of miR‐221‐3p. miR‐221‐3p expression was manipulated by transfecting KGN cells with miR‐221‐3p mimics, inhibitor, and negative control. Following transfection, apoptosis of granulosa cells was determined by flow cytometry, and the expression of the target gene was measured by quantitative real‐time polymerase chain reaction (qRT‐PCR) and western blot analysis (WB). In addition, the expression of the target gene in granulosa cells of DOR patients and NOR patients was measured. miR‐221‐3p were found to directly bind the 3ʹ untranslated region of Forkhead box O1 (FOXO1). Transfection with miR‐221‐3p mimics significantly decreased the apoptosis rate of KGN cells compared with transfection with miR‐221‐3p inhibitors. The expression level of miR‐221‐3p was negatively correlated with the messenger RNA and protein levels of the FOXO1 gene. Besides, FOXO1 expression was upregulated in DOR patients. In conclusion, these results provide evidence that downregulation of miR‐221‐3p expression promotes apoptosis of granulosa cells by upregulating FOXO1 expression, thus serving an important role in DOR pathogenesis.

Forensic transcriptome analysis using massively parallel sequencing

The application of transcriptome analyses in forensic genetics has experienced tremendous growth and development in the past decade. The earliest studies and main applications were body fluid and tissue identification, using targeted RNA transcripts and a reverse transcription endpoint PCR method. A number of markers have been identified for the forensically most relevant body fluids and tissues and the method has been successfully used in casework. The introduction of Massively Parallel Sequencing (MPS) opened up new perspectives and opportunities to advance the field. Contrary to genomic DNA where two copies of an autosomal DNA segment are present in a cell, abundant RNA species are expressed in high copy numbers. Even whole transcriptome sequencing (RNA-Seq) of forensically relevant body fluids and of postmortem material was shown to be possible. This review gives an overview on forensic transcriptome analyses and applications. The methods cover whole transcriptome as well as targeted MPS approaches. High resolution forensic transcriptome analyses using MPS are being applied to body fluid/ tissue identification, determination of the age of stains and the age of the donor, the estimation of the post-mortem interval and to post mortem death investigations.

MicroRNAs Regulating Autophagy in Neurodegeneration

Social and economic impacts of neurodegenerative diseases (NDs) become more prominent in our constantly aging population. Currently, due to the lack of knowledge about the aetiology of most NDs, only symptomatic treatment is available for patients. Hence, researchers and clinicians are in need of solid studies on pathological mechanisms of NDs. Autophagy promotes degradation of pathogenic proteins in NDs, while microRNAs post-transcriptionally regulate multiple signalling networks including autophagy. This chapter will critically discuss current research advancements in the area of microRNAs regulating autophagy in NDs. Moreover, we will introduce basic strategies and techniques used in microRNA research. Delineation of the mechanisms contributing to NDs will result in development of better approaches for their early diagnosis and effective treatment.

Circulating microRNAs Associated With Reversible Cerebral Vasoconstriction Syndrome

OBJECTIVE

The purpose of this study was to investigate the significance of circulating micro RNAs (miRNAs) in the pathogenesis of reversible cerebral vasoconstriction syndrome (RCVS).

METHODS

We prospectively recruited 3 independent cohorts of patients with RCVS and age-matched and sex-matched controls in a single medical center. Next-generation small RNA sequencing followed by quantitative polymerase chain reaction (PCR) was used to identify and validate differentially expressed miRNAs, which was cross-validated in migraine patients in ictal stage or interictal stage. Computational analysis was used to predict the target genes of miRNAs, followed by in vitro functional analysis.

RESULTS

We identified a panel of miRNAs including miR-130a-3p, miR-130b-3p, let-7a-5p, let-7b-5p, and let-7f-5p that well differentiated patients with RCVS from controls (area under the receiver operating characteristics curve [AUC] was 0.906, 0.890, and 0.867 in the 3 cohorts, respectively). The abundance of let-7a-5p, let-7b-5p, and let-7f-5p, but not miR-130a-3p nor miR-130b-3p, was significantly higher in patients with ictal migraine compared with that of controls and patients with interictal migraine. Target prediction and pathway enrichment analysis suggested that the transforming growth factor-β signaling pathway and endothelin-1 responsible for vasomotor control might link these miRNAs to RCVS pathogenesis, which was confirmed in vitro by transfecting miRNAs mimics or incubating the patients' cerebrospinal fluid (CSF) in 3 different vascular endothelial cells. Moreover, miR-130a-3p was associated with imaging-proven disruption of the blood-brain barrier (BBB) in patients with RCVS and its overexpression led to reduced transendothelial electrical resistance (ie, increased permeability) in in vitro human BBB model.

INTERPRETATION

We identified the circulating miRNA signatures associated with RCVS, which may be functionally linked to its headache, BBB integrity, and vasomotor function. ANN NEUROL 2021;89:459-473.

Non-coding RNAs as Regulators of Cellular Senescence in Idiopathic Pulmonary Fibrosis and Chronic Obstructive Pulmonary Disease

Cellular senescence is a cell fate implicated in the pathogenesis of idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD). Cellular senescence occurs in response to cellular stressors such as oxidative stress, DNA damage, telomere shortening, and mitochondrial dysfunction. Whether these stresses induce cellular senescence or an alternative cell fate depends on the type and magnitude of cellular stress, but also on intrinsic factors regulating the cellular stress response. Non-coding RNAs, including both microRNAs and long non-coding RNAs, are key regulators of cellular stress responses and susceptibility to cellular senescence. In this review, we will discuss cellular mechanisms that contribute to senescence in IPF and COPD and highlight recent advances in our understanding of how these processes are influenced by non-coding RNAs. We will also discuss the potential therapeutic role for targeting non-coding RNAs to treat these chronic lung diseases.

Age-Related Immune Profile of the T Cell Receptor Repertoire, Thymic Recent Output Function, and miRNAs

Background

T cell immunity plays a central role in the body's defense system, including maintaining homeostasis and preventing tumorigenesis and viral infection. Immune system functions degenerate with age, leading to immune senescence. Physiologically, immune senescence is characterized by a decrease in T cell receptor diversity, naive T cell deficiency, and alterations in T cell immune-related miRNAs. However, little is known about the characteristics of T cell immunosenescence in Chinese individuals.

Results

A significant decrease in the miR-17, miR-92a, and miR-181a levels in PBMCs was detected with age. The miR-92a and miR-181a levels were upregulated in CBMCs when comparing healthy individuals to group I (0~9 years), whereas miR-17 was downregulated. The sjTREC level in PBMCs was negatively correlated with age, and a sharp decrease in sjTRECs was found between groups I and II (10~19 years). Twenty-four TCR Vβ subfamilies could be detected in most samples, and most displayed polyclonality, while skewed expression of the Vβ subfamilies as well as an increased oligoclonal tendency was found with age. Similarly, the frequencies of the TCR Vγ and Vδ subfamilies decreased with age, and the alteration in clonality appeared to be stable at different ages.

Conclusion

We made the novel observation of T cell immunosenescence with age in Chinese individuals, which may provide information for immune targets to enhance the T cell immune response in immunotherapy settings for elderly patients.

Aging, MicroRNAs, and Heart Failure

Aging is a major risk factor for heart failure, one of the leading causes of death in Western society. The mechanisms that underlie the different forms of heart failure have been elucidated only in part and the role of noncoding RNAs is still poorly characterized. Specifically, microRNAs (miRNAs), a class of small noncoding RNAs that can modulate gene expression at the posttranscriptional level in all cells, including myocardial and vascular cells, have been shown to play a role in heart failure with reduced ejection fraction. In contrast, miRNAs role in heart failure with preserved ejection fraction, the predominant form of heart failure in the elderly, is still unknown. In this review, we will focus on age-dependent miRNAs in heart failure and on some other conditions that are prevalent in the elderly and are frequently associated with heart failure with preserved ejection fraction.