Circulating microRNAs as Potential Biomarkers of Endothelial Dysfunction in Obese Children

Extracellular Vesicles and Pregnancy-Related Hypertensive Disorders: A Descriptive Review on the Possible Implications "From Bench to Bedside"

Pregnancy involves extracellular vesicles (EVs) through mechanisms that are poorly understood to date. Furthermore, it is not surprising that EVs may also be involved in the pathophysiology of pre-eclampsia (PE) and gestational hypertension, two clinical conditions with high morbidity and mortality, given their capacity to mediate intracellular communications and regulate inflammation and angiogenesis. We searched major online scientific search engines (PubMed, Google Scholar, Scopus, WES, Embase, etc.) using the terms "Preeclampsia", "Pregnancy", "Hypertension", "Pregnancy-related hypertension", "Extracellular vesicles", "Biomarkers", "Gestation" AND "Obstetrics". Finding potential early biomarkers of risk or illness progression would be essential for the optimum care of expectant mothers with the aforementioned conditions. Nevertheless, none of the various screening assays that have been discovered recently have shown high predictive values. The analysis of EVs in the peripheral blood starting from the first trimester of pregnancy may hold great promise for the possible correlation with gestational hypertension problems and represent a marker of the early stages of the disease. EVs use may be a novel therapeutic approach for the management of various illnesses, as well. In order to define EVs' function in the physiopathology of pregnancy-associated hypertension and PE, as well as their potential as early biomarkers and therapeutic tools, we have compiled the most recent data in this review.

Involvement of circulating microRNAs in the pathogenesis of atherosclerosis in young patients with obesity

Obesity is considered an important factor contributing to the development of atherosclerosis. Inflammation plays a key role in endothelial dysfunction (ED), an initial stage of the atherosclerotic process. Several microRNAs (miRNAs) may play an important role in the inflammatory process, but there is a lack of information about their participation in the early stages of atherosclerosis development in patients with obesity. We aimed to assess the relations between plasma concentration of selected miRNAs, ED evaluated by reactive hyperemia index (RHI), inflammatory markers and other factors involved in the pathogenesis of atherosclerosis in adolescents and young adults with obesity. Participants (30 males, 30 females; aged 15 25 years) were divided into two groups: those with overweight/obesity (OW/O) (20 males, 20 females) and controls (C) (10 males, 10 females). The plasma concentrations of inflammatory markers, cytokines, adipocytokines, markers of lipid profile and glucose metabolism and selected miRNAs (miR 92, 126, -146a, -155) were analyzed. No significant differences in any of the miRNAs were found between the groups. MiR-146a correlated positively with RHI. Dividing the group by sex showed more significant associations between miRNA and analyzed parameters (IL-6, fasting glycemia) in men. Several observed correlations indicate a potential role of miRNAs in inflammation, the atherosclerotic process and glycemic control, primarily in male subjects with obesity. The relatively low number of observed associations between assessed parameters related to obesity and the pathogenesis of its complications could be attributed to the early stage of the atherosclerotic process in young subjects with obesity, where only subtle abnormalities are expectedly found. Key words Endothelial dysfunction, Atherosclerosis, Obesity, MicroRNA, Reactive hyperemia index.

Exosomes from IH- Induced bEnd3 Cells Promote OSA Cognitive Impairment via miR-20a-5p/MFN2 Mediated Pyroptosis of HT22 Cells

Background

OSA can cause cognitive impairment (CI). The aim of this study was to investigate whether miR-20a-5p in exosomes derived from bEnd3 cells with IH mediates intercellular crosstalk and induces CI through hippocampal neuronal cell pyroptosis.

Materials and Methods

BEnd3-derived exosomes were isolated from the normal oxygen control group (NC-EXOS) and IH group (IH-EXOS). In vitro, exosomes were cocultured with HT22 cells. Meanwhile, in vivo, exosomes were injected into mice via the caudal vein. The spatial memory ability of mice was tested by MWM method to evaluate the effect of exosomes on the cognitive function of mice. Adults diagnosed with OSA underwent the MoCA and ESS tests to assess cognitive function and daytime sleepiness. Spearman's rank correlation analysis was used to evaluate the correlation between miR-20a-5p and candidate proteins and clinical parameters. Transfection using small interfering RNAs, miRNA mimics, and plasmids to evaluate the role of miR-20a-5p and its target genes. Dual luciferase reporter gene assay was used to confirm the binding of miR-20a-5p to its target gene.

Results

IH could cause pyroptosis and inflammation in bEnd3 cells, and promote the expression of miR-20a-5p. Isolated IH-EXOS induced increased pyroptosis and activation of inflammatory response in vitro and in vivo, accompanied by increased expression of miR-20a-5p. In addition, IH-EXOS led to decreased learning and memory ability in mice. Interestingly, AHI was higher and MoCA scores were lower in severe OSA compared to healthy comparisons. In addition, miR-20a-5p and GSDMD were positively correlated with AHI but negatively correlated with MoCA in severe OSA. IH-induced exosomes were rich in miR-20a-5p, and these exosomes were found to deliver miR-20a-5p to HT22 cells, playing a key role in the induction of OSA-CI by directly targeting MFN2.

Conclusion

Exosome miR-20a-5p from IH-stimulated bEnd3 cells can promote OSA-CI by increasing HT22 cells pyroptosis through its target MFN2.

Exploring the role of exosomal MicroRNAs as potential biomarkers in preeclampsia

The complex pathogenesis of preeclampsia (PE), a significant contributor to maternal and neonatal mortality globally, is poorly understood despite substantial research. This review explores the involvement of exosomal microRNAs (exomiRs) in PE, focusing on their impact on the protein kinase B (AKT)/hypoxia-inducible factor 1-α (HIF1α)/vascular endothelial growth factor (VEGF) signaling pathway as well as endothelial cell proliferation and migration. Specifically, this article amalgamates existing evidence to reveal the pivotal role of exomiRs in regulating mesenchymal stem cell and trophoblast function, placental angiogenesis, the renin-angiotensin system, and nitric oxide production, which may contribute to PE etiology. This review emphasizes the limited knowledge regarding the role of exomiRs in PE while underscoring the potential of exomiRs as non-invasive biomarkers for PE diagnosis, prediction, and treatment. Further, it provides valuable insights into the mechanisms of PE, highlighting exomiRs as key players with clinical implications, warranting further exploration to enhance the current understanding and the development of novel therapeutic interventions.

Oxidative Stress, Inflammation, and Mitochondrial Dysfunction: A Link between Obesity and Atrial Fibrillation

The adipose tissue has long been thought to represent a passive source of triglycerides and fatty acids. However, extensive data have demonstrated that the adipose tissue is also a major endocrine organ that directly or indirectly affects the physiological functions of almost all cell types. Obesity is recognized as a risk factor for multiple systemic conditions, including metabolic syndrome, type 2 diabetes mellitus, sleep apnea, cardiovascular disorders, and many others. Obesity-related changes in the adipose tissue induce functional and structural changes in cardiac myocytes, promoting a wide range of cardiovascular disorders, including atrial fibrillation (AF). Due to the wealth of epidemiologic data linking AF to obesity, the mechanisms underlying AF occurrence in obese patients are an area of rich ongoing investigation. However, progress has been somewhat slowed by the complex phenotypes of both obesity and AF. The triad inflammation, oxidative stress, and mitochondrial dysfunction are critical for AF pathogenesis in the setting of obesity via multiple structural and functional proarrhythmic changes at the level of the atria. The aim of this paper is to provide a comprehensive view of the close relationship between obesity-induced oxidative stress, inflammation, and mitochondrial dysfunction and the pathogenesis of AF. The clinical implications of these mechanistic insights are also discussed.

Childhood Obesity, Diabetes. and Cardiovascular Disease Risk

This mini-review aims to briefly summarize the pathophysiology of childhood obesity, type 2 diabetes mellitus (T2DM), and cardiovascular disease (CVD) risk in children and adolescents. Recent data on efficacy of lifestyle interventions, medications, and metabolic surgery for obesity, T2DM, and CVD risk factors are also reviewed. We conducted a PubMed search of English-language original and review articles relevant to childhood obesity, T2DM, and CVD risk factors, and biomarkers in children with an emphasis on recent publications. Childhood obesity arises from an intricate interaction between genetic, physiologic, environmental, and socioeconomic factors. The rise in the prevalence of childhood obesity is associated with the development of comorbidities including T2DM and CVD at an early age. A multipronged approach is central to the detection, monitoring, and management of childhood obesity and associated adverse metabolic consequences.

Identification of novel circulating miRNAs biomarkers for healthy obese and lean children

BACKGROUND

The prevalence of childhood obesity and overweight has risen globally, leading to increased rates of metabolic disorders. Various factors, including genetic, epigenetic, and environmental influences such as diet and physical activity, contribute to pediatric obesity. This study aimed to identify specific circulating miRNAs as potential biomarkers for assessing obesity in children.

METHODS

Thirty children, including 15 obese and 15 extremely thin individuals, were selected for this study. MiRNA expression in circulating plasma was assessed using miRNA microarrays. The reliability of differential miRNA expression was confirmed using TaqMan qPCR. The correlation between miRNAs and obesity was analyzed through multiple linear regression, receiver operator characteristic (ROC) curve analysis, and odds ratio (OR) calculations. Bioinformatics tools were utilized to identify target genes for the selected miRNAs, and a functional network map was constructed.

RESULTS

A total of 36 differentially expressed miRNAs were identified through gene chip analysis, and TaqMan qPCR validation confirmed the upregulation of seven miRNAs: hsa-miR-126-3p, hsa-miR-15b-5p, hsa-miR-199a-3p, hsa-miR-20a-5p, hsa-miR-223-3p, hsa-miR-23a-3p, and hsa-miR-24-3p. Among these, hsa-miR-15b-5p and hsa-miR-223-3p exhibited a statistically significant difference except for hsa-miR-23a-3p. These two miRNAs showed more predicted target genes related to obesity than others. Multiple linear regression analysis revealed an association between obesity and hsa-miR-15b-5p and hsa-miR-223-3p [10.529 (4.974-16.084), -10.225 (-17.852~ -2.657)]. Even after adjusting for age and sex, these two miRNAs remained associated with obesity [8.936 (3.572-14.301), -8.449(-15.634~ -1.303)]. The area under the ROC curve (AUC) reached values of 0.816, 0.711, and 0.929, respectively. Odds ratio analysis demonstrated a significant correlation between obesity and hsa-miR-15b-5p (OR = 143, 95% CI 5.80 to 56,313, p = 0.024) and between obesity and hsa-miR-223-3p (OR = 0.01, 95% CI 0.00 to 0.23, p = 0.037). Importantly, hsa-miR-15b-5p was found to have numerous target genes associated with the FoxO, insulin, Ras, and AMPK signaling pathways.

CONCLUSIONS

Differential miRNA expression profiles in the circulation of obese children compared to controls suggest underlying metabolic abnormalities. Hsa-miR-15b-5p and hsa-miR-223-3p may be considered as molecular markers for the screening of obese children and populations at risk of developing metabolic syndrome.

The role of adipocytokines in the development of non-alcoholic fatty liver disease in children and adolescents

Over the past 20 years, the proportion of overweight and obese children and adolescents has increased significantly in most countries. Obesity represents a major cardiometabolic risk and is closely associated with comorbidities such as hypertension, hyperlipidemia, hyperinsulinemia, type 2 diabetes, and non-alcoholic fatty liver disease (NAFLD). There is a lot of uncertainty regarding the diagnosis of metabolic syndrome in children, mainly due to the various and conflicting definitions that have been proposed. The prevalence of metabolic syndrome varied significantly in children (from 6 to 39%) depending on the applied definition criteria. According to these definitions, only 2% of children met all the criteria for metabolic syndrome. Over the past decade, studies have shown that, in parallel with the increase in the prevalence of obesity in the pediatric population, NAFLD has become the most common form of liver disease in childhood. In NAFLD, inflammatory cytokines/adipokines and other factors lead to steatohepatitis and/or fibrosis. Recently, several adipocytokines and inflammatory cytokines have been identified with significant positive (leptin, chemerin, vaspin, TNF-α, IL-6 and IL-8) or negative (adiponectin) associations with metabolic risk factors. Some of them can be considered as pathophysiological factors linking obesity and its complications such as insulin resistance and NAFLD. However, data on other adipocytokines and their role in metabolism remain controversial and partially unknown, especially with regard to their role in childhood (resistin, NAMPT, FGF-21, A-FABP, RBP4, lipocalin-2, omentin-1, hsCRP). Adipocytokines are a novel and powerful tool not only for the diagnosis and stratification of NAFLD and the metabolic syndrome, but also as a potential therapeutic target. Adipocytokine therapy requires further study in all patients with metabolic syndrome and NAFLD, especially in children and adolescents.

Identification of biomarkers, pathways, and potential therapeutic targets for heart failure using next-generation sequencing data and bioinformatics analysis

BACKGROUND

Heart failure (HF) is the most common cardiovascular diseases and the leading cause of cardiovascular diseases related deaths. Increasing molecular targets have been discovered for HF prognosis and therapy. However, there is still an urgent need to identify novel biomarkers. Therefore, we evaluated biomarkers that might aid the diagnosis and treatment of HF.

METHODS

We searched next-generation sequencing (NGS) dataset (GSE161472) and identified differentially expressed genes (DEGs) by comparing 47 HF samples and 37 normal control samples using limma in R package. Gene ontology (GO) and pathway enrichment analyses of the DEGs were performed using the g: Profiler database. The protein-protein interaction (PPI) network was plotted with Human Integrated Protein-Protein Interaction rEference (HiPPIE) and visualized using Cytoscape. Module analysis of the PPI network was done using PEWCC1. Then, miRNA-hub gene regulatory network and TF-hub gene regulatory network were constructed by Cytoscape software. Finally, we performed receiver operating characteristic (ROC) curve analysis to predict the diagnostic effectiveness of the hub genes.

RESULTS

A total of 930 DEGs, 464 upregulated genes and 466 downregulated genes, were identified in HF. GO and REACTOME pathway enrichment results showed that DEGs mainly enriched in localization, small molecule metabolic process, SARS-CoV infections, and the citric acid tricarboxylic acid (TCA) cycle and respiratory electron transport. After combining the results of the PPI network miRNA-hub gene regulatory network and TF-hub gene regulatory network, 10 hub genes were selected, including heat shock protein 90 alpha family class A member 1 (HSP90AA1), arrestin beta 2 (ARRB2), myosin heavy chain 9 (MYH9), heat shock protein 90 alpha family class B member 1 (HSP90AB1), filamin A (FLNA), epidermal growth factor receptor (EGFR), phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1), cullin 4A (CUL4A), YEATS domain containing 4 (YEATS4), and lysine acetyltransferase 2B (KAT2B).

CONCLUSIONS

This discovery-driven study might be useful to provide a novel insight into the diagnosis and treatment of HF. However, more experiments are needed in the future to investigate the functional roles of these genes in HF.

Extracellular Vesicles and Hypertension

Hypertension implicates multiple organs and systems, accounting for the majority of cardiovascular diseases and cardiac death worldwide. Extracellular vesicles derived from various types of cells could transfer a variety of substances such as proteins, lipids, and nucleic acids from cells to cells, playing essential roles in both physiological and pathological processes. Extracellular vesicles are demonstrated to be closely associated with the development of essential hypertension by mediating the renin-angiotensin-aldosterone system and crosstalk between multiple vascular cells. Extracellular vesicles also participate in various kinds of pathogenesis of secondary hypertensions including acute kidney injury, renal parenchymal diseases, kidney transplantation, secretory diseases (primary aldosteronism, pheochromocytoma and paraganglioma, Cushing's syndrome), and obstructive sleep apnea. Extracellular vesicles have been proved to have the potential to be served as new biomarkers in the diagnosis, treatment, and prognosis assessment of hypertension. In the future, large multicenter cohorts are highly in demand for further verifying the sensitivity and specificity of extracellular vesicles as biomarkers.

Obstructive Sleep Apnea: A Look towards Micro-RNAs as Biomarkers of the Future

Sleep-disordered breathing (SDB) includes a broad spectrum of diseases, of which obstructive sleep apnea syndrome (OSA) is the most clinically significant manifestation. OSA is a respiratory disorder characterized by episodes of complete or partial obstruction of the upper airways that disturb ventilation and sleep architecture. In recent years, interest in the clinical implications of OSA seems to have increased, probably due to the numerous studies that have shown the existence of an important correlation between OSA and cardiovascular, dysmetabolic, and neoplastic changes. The guidelines currently available highlight the importance of diagnosis and effective treatment for OSA, underlining the need for new biomarkers that are useful in clinical practice, feasible, and reproducible to guide medical decision making. In this review, we intend to provide an overview of the potential role of microRNAs as new indicators for OSA management. MicroRNAs (miRNAs) are small non-coding RNA molecules that play an important role in RNA silencing and regulation of gene expression at the post-transcriptional level. These can bind specifically to their target genes by forming silencing complexes, thus inducing degradation or altered gene expression. A wide range of miRNAs have been extensively studied in a variety of diseases including cancer, and recently, miRNAs have been shown to have enormous potential to function as diagnostic and clinical biomarkers of disease. This review includes recent studies that establish the inevitable role of miRNAs in the pathogenesis of OSA.

EVs-miRNA: The New Molecular Markers for Chronic Respiratory Diseases

Idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), asthma and sleep disorders are chronic respiratory diseases that affect the airways, compromising lung function over time. These diseases affect hundreds of millions of people around the world and their frequency seems to be increasing every year. Extracellular vesicles (EVs) are small-sized vesicles released by every cell in the body. They are present in most body fluids and contain various biomolecules including proteins, lipids, mRNA and non-coding RNA (micro-RNA). The EVs can release their cargo, specifically micro-RNAs (miRNAs), to both neighboring and/or distal cells, playing a fundamental role in cell-cell communication. Recent studies have shown their possible role in the pathogenesis of various chronic respiratory diseases. The expression of miRNAs and, in particular, of miRNAs contained within the extracellular vesicles seems to be a good starting point in order to identify new potential biomarkers of disease, allowing a non-invasive clinical diagnosis. In this review we summarize some studies, present in the literature, about the functions of extracellular vesicles and miRNAs contained in extracellular vesicles in chronic respiratory diseases and we discuss the potential clinical applications of EVs and EVs-miRNAs for their possible use such as future biomarkers.

Identification of hsa-miR-365b-5p's role in Alzheimer's disease: a combined analysis of miRNA and mRNA microarrays

BACKGROUND

Alzheimer's disease is a prevalent health problem with a heavy global burden. Definitely diagnosed by autopsy, the clear mechanism of Alzheimer's disease pathogenesis process needs to be illustrated. MicroRNAs are suggested to be involved in many diseases. We aimed to investigate the role of microRNA in Alzheimer's disease.

METHODS

We attempted to discover the role of microRNA in Alzheimer's disease by microarray bioinformatics analysis using autopsy sample data from the GEO database. Temporal cortex samples were included in this study. Bioinformatics analyses and visualization were processed based on R.

RESULTS

After filtering out significantly differential expressed microRNAs and genes, enrichment analyses of both microRNAs and genes were conducted, respectively. Then, we constructed a transcription factor- microRNA-mRNA network and a protein-protein interaction network. In parallel, we used the receiver operating characteristic curve to evaluate the diagnostic value of microRNA. Based on the evidence, we finally identified hsa-miR-365b-5p as a key target in Alzheimer's disease.

CONCLUSIONS

Hsa-miR-365b-5p act as a key target in Alzheimer's disease. It regulates Alzheimer's disease pathogenesis process via neuroinflammation, Wnt and oxidative stress pathway which provides a potential target for Alzheimer's disease treatment.

Cardiovascular Disease-Associated MicroRNAs as Novel Biomarkers of First-Trimester Screening for Gestational Diabetes Mellitus in the Absence of Other Pregnancy-Related Complications

We assessed the diagnostic potential of cardiovascular disease-associated microRNAs for the early prediction of gestational diabetes mellitus (GDM) in singleton pregnancies of Caucasian descent in the absence of other pregnancy-related complications. Whole peripheral venous blood samples were collected within 10 to 13 weeks of gestation. This retrospective study involved all pregnancies diagnosed with only GDM (n = 121) and 80 normal term pregnancies selected with regard to equality of sample storage time. Gene expression of 29 microRNAs was assessed using real-time RT-PCR. Upregulation of 11 microRNAs (miR-1-3p, miR-20a-5p, miR-20b-5p, miR-23a-3p, miR-100-5p, miR-125b-5p, miR-126-3p, miR-181a-5p, miR-195-5p, miR-499a-5p, and miR-574-3p) was observed in pregnancies destinated to develop GDM. Combined screening of all 11 dysregulated microRNAs showed the highest accuracy for the early identification of pregnancies destinated to develop GDM. This screening identified 47.93% of GDM pregnancies at a 10.0% false positive rate (FPR). The predictive model for GDM based on aberrant microRNA expression profile was further improved via the implementation of clinical characteristics (maternal age and BMI at early stages of gestation and an infertility treatment by assisted reproductive technology). Following this, 69.17% of GDM pregnancies were identified at a 10.0% FPR. The effective prediction model specifically for severe GDM requiring administration of therapy involved using a combination of these three clinical characteristics and three microRNA biomarkers (miR-20a-5p, miR-20b-5p, and miR-195-5p). This model identified 78.95% of cases at a 10.0% FPR. The effective prediction model for GDM managed by diet only required the involvement of these three clinical characteristics and eight microRNA biomarkers (miR-1-3p, miR-20a-5p, miR-20b-5p, miR-100-5p, miR-125b-5p, miR-195-5p, miR-499a-5p, and miR-574-3p). With this, the model identified 50.50% of GDM pregnancies managed by diet only at a 10.0% FPR. When other clinical variables such as history of miscarriage, the presence of trombophilic gene mutations, positive first-trimester screening for preeclampsia and/or fetal growth restriction by the Fetal Medicine Foundation algorithm, and family history of diabetes mellitus in first-degree relatives were included in the GDM prediction model, the predictive power was further increased at a 10.0% FPR (72.50% GDM in total, 89.47% GDM requiring therapy, and 56.44% GDM managed by diet only). Cardiovascular disease-associated microRNAs represent promising early biomarkers to be implemented into routine first-trimester screening programs with a very good predictive potential for GDM.

Dietary Improvement during Lactation Normalizes miR-26a, miR-222 and miR-484 Levels in the Mammary Gland, but Not in Milk, of Diet-Induced Obese Rats

We aimed to evaluate in rats whether the levels of specific miRNA are altered in the mammary gland (MG) and milk of diet-induced obese dams, and whether improving maternal nutrition during lactation attenuates such alterations. Dams fed with a standard diet (SD) (control group), with a Western diet (WD) prior to and during gestation and lactation (WD group), or with WD prior to and during gestation but moved to SD during lactation (Rev group) were followed. The WD group showed higher miR-26a, miR-222 and miR-484 levels than the controls in the MG, but the miRNA profile in Rev animals was not different from those of the controls. The WD group also displayed higher miR-125a levels than the Rev group. Dams of the WD group, but not the Rev group, displayed lower mRNA expression levels of Rb1 (miR-26a’s target) and Elovl6 (miR-125a’s target) than the controls in the MG. The WD group also presented lower expression of Insig1 (miR-26a’s target) and Cxcr4 (miR-222’s target) than the Rev group. However, both WD and Rev animals displayed lower expression of Vegfa (miR-484’s target) than the controls. WD animals also showed greater miR-26a, miR-125a and miR-222 levels in the milk than the controls, but no differences were found between the WD and Rev groups. Thus, implementation of a healthy diet during lactation normalizes the expression levels of specific miRNAs and some target genes in the MG of diet-induced obese dams but not in milk.

Long non-coding RNA MIR4435-2HG/microRNA-125a-5p axis is involved in myocardial ischemic injuries

This study aimed to investigate whether and how long non-coding RNA (lncRNA) MIR4435-2 host gene (MIR4435-2HG) involved in acute myocardial ischemia/reperfusion (I/R). Blood samples were collected from acute myocardial infarction (AMI) patients to detect MIR4435-2HG expression. In vivo myocardial I/R mice model and in vitro H₂O₂-induced oxidative stress model were established. Echocardiography, TUNEL assay and lactate dehydrogenase (LDH) detection were performed to assess heart infarction and myocardium apoptosis. Relationship among microRNA-125a-5p (miR-125a-5p), MIR4435-2HG and Mitochondrial fission protein 1 (MTFP1) was predicted by Targetscan and verified by luciferase reporter assay. MIR4435-2HG was notably upregulated in AMI patients, myocardial I/R mice and H₂O₂-treated cells. Knockdown of MIR4435-2HG notably alleviated infraction volume, ejection fraction (EF) and fractional shortening (FS) levels, cell apoptosis portion and pro-apoptotic cleaved-caspase-3 and Cyt c expression caused by myocardial I/R and oxidative stress, as well as improved cardiomyocytes viability. Transfection with miR-125a-5p alleviated MIR4435-2HG-caused cardiomyocytes apoptosis during oxidative stress. MiR-125a-5p overexpression decreased luciferase activity of the wild-type MIR4435-2HG compared with the mutated MIR4435-2HG. The expression levels of MTFP1 were elevated in myocardium from MI mice model and H₂O₂-treated AC16 cardiomyocytes. In addition, miR-125a-5p overexpression inhibited MTFP1 expression, and could stimulate the wild-type MTFP1 promoter luciferase activity but not the mutated one. Our findings revealed the role of MIR4435-2HG in MI-induced myocardium injury and cardiomyocytes apoptosis, disclosed a novel MIR4435-2HG/miR-125a-5p regulatory axis during myocardial I/R, and thus identified a potential target for the therapy of myocardial IR injury.

The implications of exosomes in pregnancy: emerging as new diagnostic markers and therapeutics targets

Extracellular vehicles (EVs) are a heterogeneous group of cell and membranous particles originating from different cell compartments. EVs participate in many essential physiological functions and mediate fetal-maternal communications. Exosomes are the smallest unit of EVs, which are delivered to the extracellular space. Exosomes can be released by the umbilical cord, placenta, amniotic fluid, and amniotic membranes and are involved in angiogenesis, endothelial cell migration, and embryo implantation. Also, various diseases such as gestational hypertension, gestational diabetes mellitus (GDM), preterm birth, and fetal growth restriction can be related to the content of placental exosomes during pregnancy. Due to exosomes' ability to transport signaling molecules and their effect on sperm function, they can also play a role in male and female infertility. In the new insight, exosomal miRNA can diagnose and treat infertilities disorders. In this review, we focused on the functions of exosomes during pregnancy. Video abstract.

Evaluation of Early Biomarkers of Atherosclerosis Associated with Polychlorinated Biphenyl Exposure: An in Vitro and in Vivo Study

BACKGROUND

Miscellaneous cardiovascular risk factors have been defined, but the contribution of environmental pollutants exposure on cardiovascular disease (CVD) remains underappreciated.

OBJECTIVE

We investigated the potential impact of typical environmental pollutant exposure on atherogenesis and its underlying mechanisms.

METHODS

We used human umbilical vein endothelial cells (HUVECs) and apolipoprotein E knockout (ApoE-/-) mice to investigate how 2,3,5-trichloro-6-phenyl-[1,4]-benzoquinone (PCB29-pQ, a toxic polychlorinated biphenyl metabolite) affects atherogenesis and identified early biomarkers of CVD associated with PCB29-pQ exposures. Then, we used long noncoding RNAs (lncRNAs) HDAC7-AS1-overexpressing ApoE-/- mice and apolipoprotein E/caveolin 1 double-knockout (ApoE-/-/CAV1-/-) mice to address the role of these early biomarkers in PCB29-pQ-induced atherogenesis. Plasma samples from patients with coronary heart disease (CHD) were also used to confirm our findings.

RESULTS

Our data indicate that lncRNA HDAC7-AS1 bound to MIR-7-5p via argonaute 2 in PCB29-pQ-challenged HUVECs. Our mRNA sequencing assay identified transforming growth factor-β2 (TGF-β2) as a possible target gene of MIR-7-5p; HDAC7-AS1 sponged MIR-7-5p and inhibited the binding of TGF-β2 to MIR-7-5p. The effect of PCB29-pQ-induced endothelial injury, vascular inflammation, development of plaques, and atherogenesis in ApoE-/- mice was greater with MIR-7-5p-mediated TGF-β2 inhibition, whereas HDAC7-AS1-overexpressing ApoE-/- mice and ApoE-/-/CAV1-/- mice showed the opposite effect. Consistently, plasma levels of HDAC7-AS1 and MIR-7-5p were found to be significantly associated individuals diagnosed with CHD.

DISCUSSIONS

These findings demonstrated that a mechanism-based, integrated-omics approach enabled the identification of potentially clinically relevant diagnostic indicators and therapeutic targets of CHD mediated by environmental contaminants using in vitro and in vivo models of HUVECs and ApoE-/- and ApoE-/-/CAV1-/- mice. https://doi.org/10.1289/EHP9833.

Untargeted sequencing of circulating microRNAs in a healthy and diseased older population

We performed untargeted profiling of circulating microRNAs (miRNAs) in a well characterized cohort of older adults to verify associations of health and disease-related biomarkers with systemic miRNA expression. Differential expression analysis revealed 30 miRNAs that significantly differed between healthy active, healthy sedentary and sedentary cardiovascular risk patients. Increased expression of miRNAs miR-193b-5p, miR-122-5p, miR-885-3p, miR-193a-5p, miR-34a-5p, miR-505-3p, miR-194-5p, miR-27b-3p, miR-885-5p, miR-23b-5b, miR-365a-3p, miR-365b-3p, miR-22-5p was associated with a higher metabolic risk profile, unfavourable macro- and microvascular health, lower physical activity (PA) as well as cardiorespiratory fitness (CRF) levels. Increased expression of miR-342-3p, miR-1-3p, miR-92b-5p, miR-454-3p, miR-190a-5p and miR-375-3p was associated with a lower metabolic risk profile, favourable macro- and microvascular health as well as higher PA and CRF. Of note, the first two principal components explained as much as 20% and 11% of the data variance. miRNAs and their potential target genes appear to mediate disease- and health-related physiological and pathophysiological adaptations that need to be validated and supported by further downstream analysis in future studies.

Clinical Trial Registration: ClinicalTrials.gov: NCT02796976 (https://clinicaltrials.gov/ct2/show/NCT02796976).

Profiling of exosomal microRNAs expression in umbilical cord blood from normal and preeclampsia patients

Background

Epidemiological and experimental studies suggest that preeclampsia has a negative impact on maternity and offspring health. Previous studies report that dysregulation in utero-environment increases risk for elderly disease such as cardiovascular disease. However, the underlying mechanisms remain elusive. Specific microRNAs (miRNAs) are packaged in exosomes may regulate microvascular dysfunction in offspring of mothers with preeclampsia. The present study aimed to identify the differential expression profiles of microRNAs in the serum exosomes between patients with preeclampsia and normal pregnancies.

Methods

A comprehensive miRNA sequence-based approach was performed to compare exosomes carry miRNAs (Exo-miRNAs) expression levels in umbilical serum between normal and preeclampsia patients. Exosomes were isolated using the ExoQuick precipitation kit. Serum exosomes were then viewed under electron microscopy, and their characteristics determined by western blotting and nanoparticle-tracking analysis. Illumina platform was used to perform sequencing. Bioinformatics analysis was used to explore differentially expressed Exo-miRNAs in umbilical serum.

Results

Based on sequence similarity, 1733 known miRNAs were retrieved. Furthermore, 157 mature miRNAs in serum exosomes were significantly differential expressed between PE and those control groups (P<0.05, log₂|FC| > 1). Out, of the 157 miRNAs, 96 were upregulated miRNAs whereas 61 miRNAs were downregulated. The 157 differentially expressed miRNAs targeted 51,424 differentially expressed genes. Functional analysis through KEGG pathway and Gene Ontology results uncovered that target genes of miRNAs with differential expression were significantly linked to several pathways and biological processes.

Conclusion

The findings of this study showed differential expression of umbilical serum Exo-miRNAs in normal compared with PE patients, implying that these Exo-miRNAs may associate with microvascular dysfunction in offspring of mothers with preeclampsia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04449-w.

Stem cell-derived and circulating exosomal microRNAs as new potential tools for diabetic nephropathy management

BACKGROUND

Despite major advances in the treatment of diabetic nephropathy (DN) in recent years, it remains the most common cause of end-stage renal disease. An early diagnosis and therapy may slow down the DN progression. Numerous potential biomarkers are currently being researched. Circulating levels of the kidney-released exosomes and biological molecules, which reflect the DN pathology including glomerular and tubular dysfunction as well as mesangial expansion and fibrosis, have shown the potential for predicting the occurrence and progression of DN. Moreover, many experimental therapies are currently being investigated, including stem cell therapy and medications targeting inflammatory, oxidant, or pro-fibrotic pathways activated during the DN progression. The therapeutic potential of stem cells is partly depending on their secretory capacity, particularly exosomal microRNAs (Exo-miRs). In recent years, a growing line of research has shown the participation of Exo-miRs in the pathophysiological processes of DN, which may provide effective therapeutic and biomarker tools for DN treatment.

METHODS

A systematic literature search was performed in MEDLINE, Scopus, and Google Scholar to collect published findings regarding therapeutic stem cell-derived Exo-miRs for DN treatment as well as circulating Exo-miRs as potential DN-associated biomarkers.

FINDINGS

Glomerular mesangial cells and podocytes are the most important culprits in the pathogenesis of DN and, thus, can be considered valuable therapeutic targets. Preclinical investigations have shown that stem cell-derived exosomes can exert beneficial effects in DN by transferring renoprotective miRs to the injured mesangial cells and podocytes. Of note, renoprotective Exo-miR-125a secreted by adipose-derived mesenchymal stem cells can improve the injured mesangial cells, while renoprotective Exo-miRs secreted by adipose-derived stem cells (Exo-miR-486 and Exo-miR-215-5p), human urine-derived stem cells (Exo-miR-16-5p), and bone marrow-derived mesenchymal stem cells (Exo-miR-let-7a) can improve the injured podocytes. On the other hand, clinical investigations have indicated that circulating Exo-miRs isolated from urine or serum hold great potential as promising biomarkers in DN.

MicroRNAs in Obesity-Associated Disorders: The Role of Exercise Training

Obesity is a worldwide epidemic affecting over 13% of the adult population and is defined by an excess of body fat that predisposes comorbidities. It is considered a multifactorial disease in which environmental and genetic factors interact, and it is a risk marker for cardiovascular disease. Lifestyle modifications remain the mainstay of treatment for obesity based on adequate diet and physical exercise. In addition, obesity is related to cardiovascular and skeletal muscle disorders, such as cardiac hypertrophy, microvascular rarefaction, and skeletal muscle atrophy. The discovery of obesity-involved molecular pathways is an important step to improve both the prevention and management of this disease. MicroRNAs (miRNAs) are a class of gene regulators which bind most commonly, but not exclusively, to the 3'-untranslated regions of messenger RNAs of protein-coding genes and negatively regulate their expression. Considerable effort has been made to identify miRNAs and target genes that predispose to obesity. Besides their intracellular function, recent studies have demonstrated that miRNAs can be exported or released by cells and circulate within the blood in a remarkably stable form. The discovery of circulating miRNAs opens up intriguing possibilities for the use of circulating miRNA patterns as biomarkers for obesity and cardiovascular diseases. The aim of this review is to provide an overview of the recent discoveries of the role played by miRNAs in the obese phenotype and associated comorbidities. Furthermore, we will discuss the role of exercise training on regulating miRNAs, indicating the mechanisms related to these alterations.

Epigenetic regulation of pediatric and neonatal immune responses

Epigenetic regulation of transcription is a collective term that refers to mechanisms known to regulate gene transcription without changing the underlying DNA sequence. These mechanisms include DNA methylation and histone tail modifications which influence chromatin accessibility, and microRNAs that act through post-transcriptional gene silencing. Epigenetics is known to regulate a variety of biological processes, and the role of epigtenetics in immunity and immune-mediated diseases is becoming increasingly recognized. While DNA methylation is the most widely studied, each of these systems play an important role in the development and maintenance of appropriate immune responses. There is clear evidence that epigenetic mechanisms contribute to developmental stage-specific immune responses in a cell-specific manner. There is also mounting evidence that prenatal exposures alter epigenetic profiles and subsequent immune function in exposed offspring. Early life exposures that are associated with poor long-term health outcomes also appear to impact immune specific epigenetic patterning. Finally, each of these epigenetic mechanisms contribute to the pathogenesis of a wide variety of diseases that manifest during childhood. This review will discuss each of these areas in detail. IMPACT: Epigenetics, including DNA methylation, histone tail modifications, and microRNA expression, dictate immune cell phenotypes. Epigenetics influence immune development and subsequent immune health. Prenatal, perinatal, and postnatal exposures alter immune cell epigenetic profiles and subsequent immune function. Numerous pediatric-onset diseases have an epigenetic component. Several successful strategies for childhood diseases target epigenetic mechanisms.

Identification of miRNA Signature Associated With Erectile Dysfunction in Type 2 Diabetes Mellitus by Support Vector Machine-Recursive Feature Elimination

Diabetic mellitus erectile dysfunction (DMED) is one of the most common complications of diabetes mellitus (DM), which seriously affects the self-esteem and quality of life of diabetics. MicroRNAs (miRNAs) are endogenous non-coding RNAs whose expression levels can affect multiple cellular processes. Many pieces of studies have demonstrated that miRNA plays a role in the occurrence and development of DMED. However, the exact mechanism of this process is unclear. Hence, we apply miRNA sequencing from blood samples of 10 DMED patients and 10 DM controls to study the mechanisms of miRNA interactions in DMED patients. Firstly, we found four characteristic miRNAs as signature by the SVM-RFE method (hsa-let-7E-5p, hsa-miR-30 days-5p, hsa-miR-199b-5p, and hsa-miR-342–3p), called DMEDSig-4. Subsequently, we correlated DMEDSig-4 with clinical factors and further verified the ability of these miRNAs to classify samples. Finally, we functionally verified the relationship between DMEDSig-4 and DMED by pathway enrichment analysis of miRNA and its target genes. In brief, our study found four key miRNAs, which may be the key influencing factors of DMED. Meanwhile, the DMEDSig-4 could help in the development of new therapies for DMED.

The "Adipo-Cerebral" Dialogue in Childhood Obesity: Focus on Growth and Puberty. Physiopathological and Nutritional Aspects

Overweight and obesity in children and adolescents are overwhelming problems in western countries. Adipocytes, far from being only fat deposits, are capable of endocrine functions, and the endocrine activity of adipose tissue, resumable in adipokines production, seems to be a key modulator of central nervous system function, suggesting the existence of an “adipo-cerebral axis.” This connection exerts a key role in children growth and puberty development, and it is exemplified by the leptin–kisspeptin interaction. The aim of this review was to describe recent advances in the knowledge of adipose tissue endocrine functions and their relations with nutrition and growth. The peculiarities of major adipokines are briefly summarized in the first paragraph; leptin and its interaction with kisspeptin are focused on in the second paragraph; the third paragraph deals with the regulation of the GH-IGF axis, with a special focus on the model represented by growth hormone deficiency (GHD); finally, old and new nutritional aspects are described in the last paragraph.

Correlation between serum miR-122 and myocardial damage and ventricular function in patients with essential hypertension

Background

Myocardial damage and decreased ventricular function are risk factors leading to a bad prognosis in patients with essential hypertension (EH). MicroRNAs play important roles in myocardial function impairment in patients with hypertension. The purpose of our research was to investigate the correlation between serum miR-122 and myocardial damage and ventricular functions in EH patients.

Methods

The clinic data of EH patients (group A, n=60) and healthy individuals (group B, n=60) from December 2016 to December 2019 in our hospital were collected and analyzed. Serum miR-122, myocardial damage markers [B-type brain natriuretic peptide (BNP), homocysteine (Hcy), cardiac troponin T (cTnT) and creatine kinase MB isoenzyme (CK-MB)] and cardiac function indicators [ejection fraction (EF), left ventricular septal thickness (IVST), left ventricular isovolumic relaxation time (IVRT), left ventricular end-diastolic diameter (LVEDD), left ventricular posterior wall thickness (LVPWT), and left ventricular end-systolic diameter (LVESD)] were assessed in both groups. The correlation between serum miR-122 and myocardial damage markers and ventricular function indicators was analyzed.

Results

(I) The mean serum miR-122 concentration in group A and group B was 6.86±1.23 and 3.36±1.87 µmol/L, respectively. The serum miR-122 concentration in group A was evidently increased compared with that in group B. (II) The levels of BNP, Hcy, cTnT, and CK-MB in the peripheral blood in group A were evidently increased compared with those in group B (P<0.05). (III) EF and IVRT were evidently decreased in group A compared with that in group B (P<0.05). (IV) Serum miR-122 concentration was positively correlated with the myocardial damage markers BNP, Hcy, cTnT and CK-MB, and serum miR-122 concentration was negatively correlated with the ventricular function indicators EF and IVRT but not significantly correlated with other ventricular function indicators (IVST, LVEDD, LVPWT and LVESD).

Conclusions

The serum miR-122 concentration in EH patients was higher than that in healthy individuals, and miR-122 concentration was positively correlated with myocardial damage markers. Serum miR-122 level was negatively correlated with the ventricular function indicators EF and IVRT but was not significantly correlated with other ventricular function indicators (IVST, LVEDD, LVPWT, and LVESD).

Pulmonary MicroRNA Changes Alter Angiogenesis in Chronic Obstructive Pulmonary Disease and Lung Cancer

The pulmonary endothelium is dysfunctional in chronic obstructive pulmonary disease (COPD), a known risk factor for lung cancer. The pulmonary endothelium is altered in emphysema, which is disproportionately affected by cancers. Gene and microRNA expression differs between COPD and non-COPD lung. We hypothesised that the alteration in microRNA expression in the pulmonary endothelium contributes to its dysfunction. A total of 28 patients undergoing pulmonary resection were recruited and endothelial cells were isolated from healthy lung and tumour. MicroRNA expression was compared between COPD and non-COPD patients. Positive findings were confirmed by quantitative polymerase chain reaction (qPCR). Assays assessing angiogenesis and cellular migration were conducted in Human Umbilical Vein Endothelial Cells (n = 3-4) transfected with microRNA mimics and compared to cells transfected with negative control RNA. Expression of miR-181b-3p, miR-429 and miR-23c (all p < 0.05) was increased in COPD. Over-expression of miR-181b-3p was associated with reduced endothelial sprouting (p < 0.05). miR-429 was overexpressed in lung cancer as well and exhibited a reduction in tubular formation. MicroRNA-driven changes in the pulmonary endothelium thus represent a novel mechanism driving emphysema. These processes warrant further study to determine if they may be therapeutic targets in COPD and lung cancer.

Alterations in Circulating MicroRNAs and the Relation of MicroRNAs to Maximal Oxygen Consumption and Intima-Media Thickness in Ultra-Marathon Runners

The impact of long-term training on cardiovascular disease (CVD) is not clear. Carotid intima-media thickness (CIMT) test is recommended as a useful measure to diagnose the early stages of atherosclerosis. MicroRNAs (miRNAs) are altered due to endurance exercise and can be promising biomarkers of pathophysiological changes. We aimed to evaluate the association of circulating miRNAs with physical fitness and markers of atherosclerosis in ultra-marathon runners. Ultra-marathon runners had 28-fold upregulation of miR-125a-5p expressions compared to control individuals (p = 0.002), whereas let-7e and miR-126 did not differ statistically between ultra-marathon runners and controls. In the ultra-marathon runners' group, negative correlations were observed between VO₂max/kg and relative expression of miR-125a-5p and miR-126 (r = -0.402, p = 0.028; r = -0.438, p = 0.032, respectively). Positive correlations were observed between CIMT and miR-125a-5p and miR-126 (r = 0.388, p = 0.050; r = 0.504, p = 0.023, respectively) in ultra-marathon runners. Individuals with the highest quartile of VO₂max/kg had 23-fold lower miR-126 expression in comparison to subgroups with lower VO₂max/kg (p = 0.017). Our results may indicate that both miRNAs may serve as a biomarker for early pathological changes leading to atherosclerosis burden in athletes. Furthermore, the association between miRNAs and traditional risk factors for CVD indicate a possible use of these molecules as early biomarkers of future cardiovascular health.

Novel proteins associated with chronic intermittent hypoxia and obstructive sleep apnea: From rat model to clinical evidence

OBJECTIVE

To screen for obstructive sleep apnea (OSA) biomarkers, isobaric tags for relative and absolute quantitation (iTRAQ)-labeled quantitative proteomics assay was used to identify differentially expressed proteins (DEPs) during chronic intermittent hypoxia (CIH).

METHOD

The iTRAQ technique was applied to compare DEPs in the serum of a CIH rat model and control group. Biological analysis of DEPs was performed using Gene Ontology and Kyoto Encyclopedia to explore related biological functions and signaling pathways. Enzyme-linked immunosorbent assay (ELISA) was performed to validate their expression in sera from patients with OSA and CIH rats.

RESULTS

Twenty-three DEPs (fold change ≥1.2 or ≤0.833, p<0.05) were identified, and two DEPs (unique peptides>3 and higher coverage) were further verified by ELISA in the CIH rat model and OSA subject: apolipoprotein A-IV (APOA4, p<0.05) and Tubulin alpha-1A chain (TUBA1A, p<0.05). Both groups showed significant differences in the expression levels of DEPs between the CIH and control groups and the severe OSA and non-OSA groups. APOA4 was found to be upregulated and TUBA1A downregulated in both the sera from OSA patients and CIH rats, on comparing proteomics results with clinical results. There were two pathways that involved three DEPs, the mitogen-activated protein kinase (MAPK) signaling pathway (p<0.05) and cytokine-cytokine receptor interaction (p<0.05).

CONCLUSION

APOA4 and TUBA1A may be potential novel biomarkers for CIH and OSA, and may play an important role in the development of OSA complications.

Phenotypic variance in pediatric obstructive sleep apnea

It is crucial that clinicians understand what underpins the considerable phenotypic variance in pediatric obstructive sleep apnea syndrome (OSAS), if they are to implement individually tailored phenotype-based approaches to diagnosis and management. This review summarizes the current literature on how disease severity, comorbidities, genetic and environmental/lifestyle factors interact to determine the overall OSAS phenotype. The first part discusses the impact of these factors on OSAS-related morbidity in the context of otherwise healthy children, whilst the second half details children with complex conditions, particularly focusing on the anatomical and functional abnormalities predisposing to upper airway obstruction unique to each condition. One can then understand the need for a multidimensional assessment strategy for pediatric OSAS; one that incorporates the history, physical examination, sleep study results, and biomarkers to enable precise stratification, so vital for effective determination of the timing and the nature of the therapeutic interventions required.

High fructose exposure modifies the amount of adipocyte-secreted microRNAs into extracellular vesicles in supernatants and plasma

Background

High fructose exposure induces metabolic and endocrine responses in adipose tissue. Recent evidence suggests that microRNAs in extracellular vesicles are endocrine signals secreted by adipocytes. Fructose exposure on the secretion of microRNA by tissues and cells is poorly studied. Thus, the aim of this study was to evaluate the effect of fructose exposure on the secretion of selected microRNAs in extracellular vesicles from 3T3-L1 cells and plasma from Wistar rats.

Methods

3T3-L1 cells were exposed to 550 µM of fructose or standard media for four days, microRNAs levels were determined in extracellular vesicles of supernatants and cells by RT-qPCR. Wistar rats were exposed to either 20% fructose drink or tap water for eight weeks, microRNAs levels were determined in extracellular vesicles of plasma and adipose tissue by RT-qPCR.

Results

This study showed that fructose exposure increased the total number of extracellular vesicles released by 3T3-L1 cells (p = 0.0001). The levels of miR-143-5p were increased in extracellular vesicles of 3T3-L1 cells exposed to fructose (p = 0.0286), whereas miR-223-3p levels were reduced (p = 0.0286). Moreover, in plasma-derived extracellular vesicles, miR-143-5p was higher in fructose-fed rats (p = 0.001), whereas miR-223-3p (p = 0.022), miR-342-3p (p = 0.0011), miR-140-5p (p = 0.0129) and miR-146b-5p (p = 0.0245) were lower.

Conclusion

Fructose exposure modifies the levels of microRNAs in extracellular vesicles in vitro and in vivo. In particular, fructose exposure increases miR-143-5p, while decreases miR-223-3p and miR-342-3p.

The Potential Role of Exosomes in Child and Adolescent Obesity

Child and adolescent obesity constitute one of the greatest contemporary public health menaces. The enduring disproportion between calorie intake and energy consumption, determined by a complex interaction of genetic, epigenetic, and environmental factors, finally leads to the development of overweight and obesity. Child and adolescent overweight/obesity promotes smoldering systemic inflammation (“para-inflammation”) and increases the likelihood of later metabolic and cardiovascular complications, including metabolic syndrome and its components, which progressively deteriorate during adulthood. Exosomes are endosome-derived extracellular vesicles that are secreted by a variety of cells, are naturally taken-up by target cells, and may be involved in many physiological and pathological processes. Over the last decade, intensive research has been conducted regarding the special role of exosomes and the non-coding (nc) RNAs they contain (primarily micro (mi) RNAs, long (l) non-coding RNAs, messenger (m) RNAs and other molecules) in inter-cellular communications. Through their action as communication mediators, exosomes may contribute to the pathogenesis of obesity and associated disorders. There is increasing evidence that exosomal miRNAs and lncRNAs are involved in pivotal processes of adipocyte biology and that, possibly, play important roles in gene regulation linked to human obesity. This review aims to improve our understanding of the roles of exosomes and their cargo in the development of obesity and related metabolic and inflammatory disorders. We examined their potential roles in adipose tissue physiology and reviewed the scarce data regarding the altered patterns of circulating miRNAs and lncRNAs observed in obese children and adolescents, compared them to the equivalent, more abundant existing findings of adult studies, and speculated on their proposed mechanisms of action. Exosomal miRNAs and lncRNAs could be applied as cardiometabolic risk biomarkers, useful in the early diagnosis and prevention of obesity. Furthermore, the targeting of crucial circulating exosomal cargo to tissues involved in the pathogenesis and maintenance of obesity could provide a novel therapeutic approach to this devastating and management-resistant pandemic.

Association Analysis in Children Born from Normal and Complicated Pregnancies-Cardiovascular Disease Associated microRNAs and the Incidence of Prehypertension/Hypertension, Overweight/Obesity, Valve Problems and Heart Defects

The goal was to assess how a history of any kind of pregnancy-related complication altered expression profile of microRNAs played a role in the pathogenesis of diabetes, cardiovascular and cerebrovascular diseases in the peripheral blood leukocytes of children at the age of 3–11 years. The prior exposure to gestational hypertension, preeclampsia, fetal growth restriction, gestational diabetes mellitus, preterm prelabor rupture of membranes or spontaneous preterm birth causes that a significant proportion of children (57.42% to 90.0% specifically) had a substantially altered microRNA expression profile, which might be the origin of a lifelong cardiovascular risk. A total of 23 out of 29 tested microRNAs were upregulated in children born from such complicated gestation. The occurrence of overweight, obesity, valve problems and heart defects even intensified upregulation of microRNAs already present in children exposed to such pregnancy complications. The occurrence of overweight/obesity (miR-92a-3p, and miR-210-3p) and valve problems or heart defects (miR-342-3p) induced microRNA upregulation in children affected with pregnancy complications. Overall, 42.86% overweight/obese children and 27.36% children with valve problems or heart defects had even higher microRNA levels than children with normal clinical findings after complicated pregnancies. In addition, the microRNA expression profile was also able to differentiate between children descending from normal gestation in relation to the occurrence of overweight and obesity. Screening on the base of the combination of 19 microRNAs identified 70.0% overweight/obese children at 90.0% specificity. In general, children after complicated pregnancies, just as children after normal pregnancies, with abnormal findings are at a higher risk of the onset of cardiovascular complications, and their dispensarization, with the aim to implement primary prevention strategies, would be beneficial.

Fibrinolytic Activity of Circulating Microvesicles Is Associated with Progression of Breast Cancer

The fibrinolytic system plays an important role in breast cancer, favoring progression through extracellular-matrix degradation, angiogenesis, apoptosis and cellular proliferation. The expression of urokinase-type plasminogen activator (uPA) in breast cancer tissue is widely recognized as an unfavorable prognostic factor. However, fibrinolytic activity associated with uPA cannot be reliably measured in the blood because of the rapid inhibition of uPA by plasminogen activator inhibitor-1 (PAI-1). By contrast, circulating microvesicles (Mvs) in peripheral blood protect bound enzymes from inhibition. Mvs are extracellular vesicles, released from various types of cells, and their size fluctuates between 100 and 1,000 nm. Mvs carry DNA, RNA, miRNA, and proteins, thereby serving as a source of horizontal communication between cells. We investigated whether fibrinolytic activity on circulating Mvs reflects breast cancer progression. The study population consisted of 13 patients with breast cancer and 13 healthy women. The cancer patients included 4 patients in remission, 3 patients with locally advanced cancer, and 6 with metastatic disease. Mvs were isolated from peripheral blood, quantified by a protein concentration method, and their fibrinolytic potential was measured by their capacity to generate plasmin. Although the quantity of Mvs found in patients with cancer and healthy individuals was similar, plasmin generated on Mvs was twice the amount in patients with metastasis than in healthy women (P < 0.05), underlying the value of this distinctive parameter. The data suggest that in breast cancer patients, higher fibrinolytic activity of circulating Mvs could be related to progression and metastasis of breast cancer.

Circulating Exosomal miRNAs Signal Circadian Misalignment to Peripheral Metabolic Tissues

Night shift work increases risk of metabolic disorders, particularly obesity and insulin resistance. While the underlying mechanisms are unknown, evidence points to misalignment of peripheral oscillators causing metabolic disturbances. A pathway conveying such misalignment may involve exosome-based intercellular communication. Fourteen volunteers were assigned to a simulated day shift (DS) or night shift (NS) condition. After 3 days on the simulated shift schedule, blood samples were collected during a 24-h constant routine protocol. Exosomes were isolated from the plasma samples from each of the blood draws. Exosomes were added to naïve differentiated adipocytes, and insulin-induced pAkt/Akt expression changes were assessed. ChIP-Seq analyses for BMAL1 protein, mRNA microarrays and exosomal miRNA arrays combined with bioinformatics and functional effects of agomirs and antagomirs targeting miRNAs in NS and DS exosomal cargo were examined. Human adipocytes treated with exosomes from the NS condition showed altered Akt phosphorylation responses to insulin in comparison to those treated with exosomes from the DS condition. BMAL1 ChIP-Seq of exosome-treated adipocytes showed 42,037 binding sites in the DS condition and 5538 sites in the NS condition, with a large proportion of BMAL1 targets including genes encoding for metabolic regulators. A significant and restricted miRNA exosomal signature emerged after exposure to the NS condition. Among the exosomal miRNAs regulated differentially after 3 days of simulated NS versus DS, proof-of-concept validation of circadian misalignment signaling was demonstrated with hsa-mir-3614-5p. Exosomes from the NS condition markedly altered expression of key genes related to circadian rhythm in several cultured cell types, including adipocytes, myocytes, and hepatocytes, along with significant changes in 29 genes and downstream gene network interactions. Our results indicate that a simulated NS schedule leads to changes in exosomal cargo in the circulation. These changes promote reduction of insulin sensitivity of adipocytes in vitro and alter the expression of core clock genes in peripheral tissues. Circulating exosomal miRNAs may play an important role in metabolic dysfunction in NS workers by serving as messengers of circadian misalignment to peripheral tissues.

Cardiovascular morbidities of obstructive sleep apnea and the role of circulating extracellular vesicles

Obstructive sleep apnea (OSA) is characterized by recurrent upper airway collapse during sleep resulting in impaired blood gas exchange, namely intermittent hypoxia (IH) and hypercapnia, fragmented sleep (SF), increased oxidative stress and systemic inflammation. Among a myriad of potential associated morbidities, OSA has been particularly implicated as mechanistically contributing to the prevalence and severity of cardiovascular diseases (CVD). However, the benefits of continuous positive airway pressure (CPAP), which is generally employed in OSA treatment, to either prevent or improve CVD outcomes remain unconvincing, suggesting that the pathophysiological mechanisms underlying the incremental CVD risk associated with OSA are not clearly understood. One of the challenges in development of non-invasive diagnostic assays is the ability to identify clinically and mechanistically relevant biomarkers. Circulating extracellular vesicles (EVs) and their cargos reflect underlying changes in cellular homeostasis and can provide insights into how cells and systems cope with physiological perturbations by virtue of the identity and abundance of miRNAs, mRNAs, proteins, and lipids that are packaged in the EVs under normal as well as diseased states, such as OSA. EVs can not only provide unique insights into coordinated cellular responses at the organ or systemic level, but can also serve as reporters of the effects of OSA in CVD, either by their properties enabling regeneration and repair of injured vascular cells or by damaging them. Here, we highlight recent progress in the pathological CVD consequences of OSA, and explore the putative roles of EVs in OSA-associated CVD, along with emerging diagnostic and therapeutic opportunities.

The reviews of this paper are available via the supplemental material section.

Substantially Altered Expression Profile of Diabetes/Cardiovascular/Cerebrovascular Disease Associated microRNAs in Children Descending from Pregnancy Complicated by Gestational Diabetes Mellitus-One of Several Possible Reasons for an Increased Cardiovascular Risk

Gestational diabetes mellitus (GDM), one of the major pregnancy-related complications, characterized as a transitory form of diabetes induced by insulin resistance accompanied by a low/absent pancreatic beta-cell compensatory adaptation to the increased insulin demand, causes the acute, long-term, and transgenerational health complications. The aim of the study was to assess if alterations in gene expression of microRNAs associated with diabetes/cardiovascular/cerebrovascular diseases are present in whole peripheral blood of children aged 3-11 years descending from GDM complicated pregnancies. A substantially altered microRNA expression profile was found in children descending from GDM complicated pregnancies. Almost all microRNAs with the exception of miR-92a-3p, miR-155-5p, and miR-210-3p were upregulated. The microRNA expression profile also differed between children after normal and GDM complicated pregnancies in relation to the presence of overweight/obesity, prehypertension/hypertension, and/or valve problems and heart defects. Always, screening based on the combination of microRNAs was superior over using individual microRNAs, since at 10.0% false positive rate it was able to identify a large proportion of children with an aberrant microRNA expression profile (88.14% regardless of clinical findings, 75.41% with normal clinical findings, and 96.49% with abnormal clinical findings). In addition, the higher incidence of valve problems and heart defects was found in children with a prior exposure to GDM. The extensive file of predicted targets of all microRNAs aberrantly expressed in children descending from GDM complicated pregnancies indicates that a large group of these genes is involved in ontologies of diabetes/cardiovascular/cerebrovascular diseases. In general, children with a prior exposure to GDM are at higher risk of later development of diabetes mellitus and cardiovascular/cerebrovascular diseases, and would benefit from dispensarisation as well as implementation of primary prevention strategies.

Diabetes Mellitus and Cardiovascular Risk Assessment in Mothers with a History of Gestational Diabetes Mellitus Based on Postpartal Expression Profile of MicroRNAs Associated with Diabetes Mellitus and Cardiovascular and Cerebrovascular Diseases

Mothers with a history of gestational diabetes mellitus (GDM) have an increased risk of developing diabetes in the future and a lifelong cardiovascular risk. Postpartal expression profile of cardiovascular/cerebrovascular disease associated microRNAs was assessed 3–11 years after the delivery in whole peripheral blood of young and middle-aged mothers with a prior exposure to GDM with the aim to identify a high-risk group of mothers at risk of later development of diabetes mellitus and cardiovascular/cerebrovascular diseases who would benefit from implementation of early primary prevention strategies and long-term follow-up. The hypothesis of the assessment of cardiovascular risk in women was based on the knowledge that a series of microRNAs play a role in the pathogenesis of diabetes mellitus and cardiovascular/cerebrovascular diseases. Abnormal expression profile of multiple microRNAs was found in women with a prior exposure to GDM (miR-1-3p, miR-16-5p, miR-17-5p, miR-20a-5p, miR-20b-5p, miR-21-5p, miR-23a-3p, miR-24-3p, miR-26a-5p, miR-29a-3p, miR-100-5p, miR-103a-3p, miR-125b-5p, miR-126-3p, miR-130b-3p, miR-133a-3p, miR-143-3p, miR-145-5p, miR-146a-5p, miR-181a-5p, miR-195-5p, miR-199a-5p, miR-221-3p, miR-342-3p, miR-499a-5p, and-miR-574-3p). Postpartal combined screening of miR-1-3p, miR-16-5p, miR-17-5p, miR-20b-5p, miR-21-5p, miR-23a-3p, miR-26a-5p, miR-29a-3p, miR-103a-3p, miR-133a-3p, miR-146a-5p, miR-181a-5p, miR-195-5p, miR-199a-5p, miR-221-3p, and miR-499a-5p showed the highest accuracy for the identification of mothers with a prior exposure to GDM at a higher risk of later development of cardiovascular/cerebrovascular diseases (AUC 0.900, p < 0.001, sensitivity 77.48%, specificity 93.26%, cut off >0.611270413). It was able to identify 77.48% mothers with an increased cardiovascular risk at 10.0% FPR. Any of changes in epigenome (upregulation of miR-16-5p, miR-17-5p, miR-29a-3p, and miR-195-5p) that were induced by GDM-complicated pregnancy are long-acting and may predispose mothers affected with GDM to later development of diabetes mellitus and cardiovascular/cerebrovascular diseases. In addition, novel epigenetic changes (upregulation of serious of microRNAs) appeared in a proportion of women that were exposed to GDM throughout the postpartal life. Likewise, a previous occurrence of either GH, PE, and/or FGR, as well as a previous occurrence of GDM, is associated with the upregulation of miR-1-3p, miR-17-5p, miR-20a-5p, miR-20b-5p, miR-29a-3p, miR-100-5p, miR-125b-5p, miR-126-3p, miR-130b-3p, miR-133a-3p, miR-143-3p, miR-145-5p, miR-146a-5p, miR-181a-5p, miR-199a-5p, miR-221-3p, and miR-499a-5p. On the other hand, upregulation of miR-16-5p, miR-21-5p, miR-23a-3p, miR-24-3p, miR-26a-5p, miR-103a-3p, miR-195-5p, miR-342-3p, and miR-574-3p represents a unique feature of aberrant expression profile of women with a prior exposure to GDM. Screening of particular microRNAs may stratify a high-risk group of mothers with a history of GDM who might benefit from implementation of early primary prevention strategies.

Unique microRNA Signals in Plasma Exosomes from Pregnancies Complicated by Preeclampsia

Although preeclampsia is a common and serious complication of pregnancy, insight into its pathobiology and diagnosis is lacking. Circulating plasma exosomes, which contain RNA and other molecules and have recently become accessible for diagnostics, may be informative in this regard. We tested the hypothesis that preeclampsia may affect the miRNA cargo within circulating maternal blood exosomes. We collected plasma from 60 pregnant women at term, including 20 women with pregnancy complicated by preeclampsia, and 20 women with fetal growth restriction and 20 with healthy pregnancy, serving as controls. We isolated exosomes from the maternal plasma by continuous density gradient ultracentrifugation. Our main outcome variable was exosomal miRNA cargo, analyzed by quantitative polymerase chain reaction-based TaqMan advanced miRNA assay in a card format and the expression of differentially expressed exosomal miRNA in whole plasma from the same participants. We found that 7 miRNA species were differentially expressed in exosomes from women with preeclampsia and those from controls. In contrast, there was no significant difference in exosomal miRNA expression between women with fetal growth restriction and controls. The results were not affected by fetal sex. Only one of the preeclampsia-related, differentially expressed exosomal miRNAs was significantly different in whole plasma miRNA analysis. We concluded that unlike whole plasma miRNA, exosomes extracted from the plasma of women with preeclampsia exhibit a unique miRNA profile, suggesting that plasma exosomal miRNA could provide insight into the pathophysiology of preeclampsia, and may play a role in disease diagnostics.

Plasma exosomes in OSA patients promote endothelial senescence: effect of long-term adherent continuous positive airway pressure

Obstructive sleep apnea (OSA) is associated with increased risk for end-organ morbidities, which can collectively be viewed as accelerated aging. Vascular senescence is an important contributor to end-organ dysfunction. Exosomes are released ubiquitously into the circulation, and transfer their cargo to target cells facilitating physiological and pathological processes. Plasma exosomes from 15 patients with polysomnographically diagnosed OSA at baseline (OSA-T1) after 12 months of adherent continuous positive airway pressure (CPAP) treatment (OSA-T2), 13 untreated OSA patients at 12-month intervals (OSA-NT1, OSA-NT2), and 12 controls (CO1 and CO2) were applied on naïve human microvascular endothelialcells-dermal (HMVEC-d). Expression of several senescence gene markers including p16 (CDKN2A), SIRT1, and SIRT6 and immunostaining for β-galactosidase activity (x-gal) were performed. Endothelial cells were also exposed to intermittent hypoxia (IH) or normoxia (RA) or treated with hydrogen peroxide (H2O2), stained with x-gal and subjected to qRT-PCR. Exosomes from OSA-T1, OSA-NT1, and OSA-NT2 induced significant increases in x-gal staining compared to OSA-T2, CO1, and CO2 (p-value < 0.01). p16 expression was significantly increased (p < 0.01), while SIRT1 and SIRT6 expression levels were decreased (p < 0.02 and p < 0.009). Endothelial cells exposed to IH or to H2O2 showed significant increases in x-gal staining (p < 0.001) and in senescence gene expression. Circulating exosomes in untreated OSA induce marked and significant increases in senescence of naïve endothelial cells, which are only partially reversible upon long-term adherent CPAP treatment. Furthermore, endothelial cells exposed to IH or H2O2 also elicit similar responses. Thus, OSA either directly or indirectly via exosomes may initiate and exacerbate cellular aging, possibly via oxidative stress-related pathways.

MiRNAs as Novel Adipokines: Obesity-Related Circulating MiRNAs Influence Chemosensitivity in Cancer Patients

Adipose tissue is an endocrine organ, capable of regulating distant physiological processes in other tissues via the release of adipokines into the bloodstream. Recently, circulating adipose-derived microRNAs (miRNAs) have been proposed as a novel class of adipokine, due to their capacity to regulate gene expression in tissues other than fat. Circulating levels of adipokines are known to be altered in obese individuals compared with typical weight individuals and are linked to poorer health outcomes. For example, obese individuals are known to be more prone to the development of some cancers, and less likely to achieve event-free survival following chemotherapy. The purpose of this review was twofold; first to identify circulating miRNAs which are reproducibly altered in obesity, and secondly to identify mechanisms by which these obesity-linked miRNAs might influence the sensitivity of tumors to treatment. We identified 8 candidate circulating miRNAs with altered levels in obese individuals (6 increased, 2 decreased). A second literature review was then performed to investigate if these candidates might have a role in mediating resistance to cancer treatment. All of the circulating miRNAs identified were capable of mediating responses to cancer treatment at the cellular level, and so this review provides novel insights which can be used by future studies which aim to improve obese patient outcomes.

Plasma Extracellular Vesicles in Children with OSA Disrupt Blood-Brain Barrier Integrity and Endothelial Cell Wound Healing in Vitro

Pediatric obstructive sleep apnea (P-OSA) is associated with neurocognitive deficits and endothelial dysfunction, suggesting the possibility that disruption of the blood-brain barrier (BBB) may underlie these morbidities. Extracellular vesicles (EVs), which include exosomes, are small particles involved in cell-cell communications via different mechanisms and could play a role in OSA-associated end-organ injury. To examine the roles of EVs in BBB dysfunction, we recruited three groups of children: (a) absence of OSA or cognitive deficits (CL, n = 6), (b) OSA but no evidence of cognitive deficits (OSA-NC(-), n = 12), and (c) OSA with evidence of neurocognitive deficits (OSA-NC(+), n = 12). All children were age-, gender-, ethnicity-, and BMI-z-score-matched, and those with OSA were also apnea-hypopnea index (AHI)-matched. Plasma EVs were characterized, quantified, and applied on multiple endothelial cell types (HCAEC, HIAEC, human HMVEC-D, HMVEC-C, HMVEC-L, and hCMEC/D3) while measuring monolayer barrier integrity and wound-healing responses. EVs from OSA children induced significant declines in hCMEC/D3 transendothelial impedance compared to CL (p < 0.001), and such changes were greater in NC(+) compared to NC(-) (p < 0.01). The effects of EVs from each group on wound healing for HCAEC, HIAEC, HMVED-d, and hCMEC/D3 cells were similar, but exhibited significant differences across the three groups, with evidence of disrupted wound healing in P-OSA. However, wound healing in HMVEC-C was only affected by NC(+) (p < 0.01 vs. NC(-) or controls (CO). Furthermore, no significant differences emerged in HMVEC-L cell wound healing across all three groups. We conclude that circulating plasma EVs in P-OSA disrupt the integrity of the BBB and exert adverse effects on endothelial wound healing, particularly among OSA-NC(+) children, while also exhibiting endothelial cell type selectivity. Thus, circulating EVs cargo may play important roles in the emergence of end-organ morbidity in pediatric OSA.

Circulating microRNAs in human obesity: a systematic review

Context: Differential expression profiles of microRNAs have been reported in human obesity suggesting a miRNAs role in the development of obesity and associated disorders. Objective: To review circulating microRNAs (c-miRNAs) dysregulated in human obesity and to predict their possible target genes. Methods: We performed a systematic review on PubMed database (PROSPERO, CRD42017077742) for original works on c-miRNAs and human obesity and recorded c-miRNAs with differential expression profiles. Potential target genes and metabolic pathways for dysregulated miRNAs with at least two independent reports were searched using bioinformatic tools. Results: Twenty-two c-miRNAs are overexpressed, nine underexpressed and two c-miRNAs dysregulated in both directions in people with obesity compared to lean controls. Bioinformatic analyses suggest these c-miRNAs target on genes associated with fatty acid metabolism and PI3k/Akt pathway. Conclusion: Literature records 33 c-miRNAs confirmedly dysregulated in human obesity. Their predicted target genes are involved in pathways that could explain the development of obesity and its comorbidities. Further research will clarify the role of these miRNAs on metabolic diseases and their usefulness for the prognosis, prevention and treatment of obesity.

Postnatal Expression Profile of microRNAs Associated with Cardiovascular and Cerebrovascular Diseases in Children at the Age of 3 to 11 Years in Relation to Previous Occurrence of Pregnancy-Related Complications

Children descending from pregnancies complicated by gestational hypertension (GH), preeclampsia (PE) or fetal growth restriction (FGR) have a lifelong cardiovascular risk. The aim of the study was to verify if pregnancy complications induce postnatal alterations in gene expression of microRNAs associated with cardiovascular/cerebrovascular diseases. Twenty-nine microRNAs were assessed in peripheral blood, compared between groups, and analyzed in relation to both aspects, the current presence of cardiovascular risk factors and cardiovascular complications and the previous occurrence of pregnancy complications with regard to the clinical signs, dates of delivery, and Doppler ultrasound examination. The expression profile of miR-21-5p differed between controls and children with a history of uncomplicated pregnancies with abnormal clinical findings. Abnormal expression profile of multiple microRNAs was found in children affected with GH (miR-1-3p, miR-17-5p, miR-20a-5p, miR-21-5p, miR-23a-3p, miR-26a-5p, miR-29a-3p, miR-103a-3p, miR-125b-5p, miR-126-3p, miR-133a-3p, miR-146a-5p, miR-181a-5p, miR-195-5p, and miR-342-3p), PE (miR-1-3p, miR-20a-5p, miR-20b-5p, miR-103a-3p, miR-133a-3p, miR-342-3p), and FGR (miR-17-5p, miR-126-3p, miR-133a-3p). The index of pulsatility in the ductus venosus showed a strong positive correlation with miR-210-3p gene expression in children exposed to PE and/or FGR. Any of changes in epigenome (up-regulation of miR-1-3p and miR-133a-3p) that were induced by pregnancy complications are long-acting and may predispose children affected with GH, PE, or FGR to later development of cardiovascular/cerebrovascular diseases. Novel epigenetic changes (aberrant expression profile of microRNAs) appeared in a proportion of children that were exposed to GH, PE, or FGR. Screening of particular microRNAs may stratify a highly risky group of children that might benefit from implementation of early primary prevention strategies.

Gut Microbiota and Endothelial Dysfunction Markers in Obese Mexican Children and Adolescents

Obesity is a metabolic disease characterized by low-grade inflammation and accompanied by dyslipidemia and up-regulation of other bioactive molecules, creating a predisposition to endothelial dysfunction and metabolic syndrome. We studied the association between gut microbiota diversity and endothelial dysfunction (EDF) markers in obese Mexican children and adolescents. We examined clinical data including metabolic factors and EDF markers in blood samples. Gut bacterial diversity was characterized by high-throughput sequencing of V3-16S rDNA libraries. Triglycerides, insulin, homeostasis model assessment-insulin resistant (HOMA-IR), leptin, C-reactive protein (CRP), and EDF marker intercellular adhesion molecule 1 (ICAM-1) were significantly higher in obese children and adolescents. Multivariate analysis showed statistically significant positive associations between vascular cell adhesion molecule 1 (VCAM-1) and Veillonellaceae, and between ICAM-1 and Ruminococcus in obese children. In obese adolescents, there was a statistically significant positive association between total cholesterol and Ruminococcus, and between ICAM-1 and Bacteroides. LEfSe analysis showed that the genus Lactobacillus and family Coriobacteriaceae were enriched in children, and genera Collinsella and Prevotella were enriched in obese adolescents. Obese children and adolescents had higher levels of insulin resistance and metabolic syndrome. These results suggest that obese Mexican children and adolescents had increased levels of CRP and a reduction of adiponectin, which causes higher expression of EDF markers, affecting endothelial function and associating with changes in the gut microbiota.

Exosome and Macrophage Crosstalk in Sleep-Disordered Breathing-Induced Metabolic Dysfunction

Obstructive sleep apnea (OSA) is a highly prevalent worldwide public health problem that is characterized by repetitive upper airway collapse leading to intermittent hypoxia, pronounced negative intrathoracic pressures, and recurrent arousals resulting in sleep fragmentation. Obesity is a major risk factor of OSA and both of these two closely intertwined conditions result in increased sympathetic activity, oxidative stress, and chronic low-grade inflammation, which ultimately contribute, among other morbidities, to metabolic dysfunction, as reflected by visceral white adipose tissue (VWAT) insulin resistance (IR). Circulating extracellular vesicles (EVs), including exosomes, are released by most cell types and their cargos vary greatly and reflect underlying changes in cellular homeostasis. Thus, exosomes can provide insights into how cells and systems cope with physiological perturbations by virtue of the identity and abundance of miRNAs, mRNAs, proteins, and lipids that are packaged in the EVs cargo, and are secreted from the cells into bodily fluids under normal as well as diseased states. Accordingly, exosomes represent a novel pathway via which a cohort of biomolecules can travel long distances and result in the modulation of gene expression in selected and targeted recipient cells. For example, exosomes secreted from macrophages play a critical role in innate immunity and also initiate the adaptive immune response within specific metabolic tissues such as VWAT. Under normal conditions, phagocyte-derived exosomes represent a large portion of circulating EVs in blood, and carry a protective signature against IR that is altered when secreting cells are exposed to altered physiological conditions such as those elicited by OSA, leading to emergence of IR within VWAT compartment. Consequently, increased understanding of exosome biogenesis and biology should lead to development of new diagnostic biomarker assays and personalized therapeutic approaches. Here, the evidence on the major biological functions of macrophages and exosomes as pathophysiological effectors of OSA-induced metabolic dysfunction is discussed.

Novel Insights in the Metabolic Syndrome in Childhood and Adolescence

Metabolic syndrome (MetS) is recognized as an escalating major health risk in adults as well as in children and adolescents. Its prevalence ranges from 6 to 39% depending on the applied definition criteria. To date, there is no consensus on a MetS definition for children and adolescents. However, most authors agree on essential components such as glucose intolerance, central obesity, hypertension, and dyslipidemia; each representing a risk for cardiovascular disease. Recently, associations between MetS and non-alcoholic fatty liver disease, hyperuricemia, and sleep disturbances have emerged. Biomarkers like adipocytokines are a subject of current research as they are implicated in the pathogenesis of the MetS. Epigenetics and gestational programming, especially the role of microRNA, comprise a novel, rapidly developing and promising research focus on the topic of MetS. MicroRNAs are increasingly valued for potential roles in the diagnosis, stratification, and therapeutics of MetS. Early detection of risk factors, screening for metabolic disturbances, and the identification of new therapies are major aims to reduce morbidity and mortality related to MetS. Dietary modification and physical activity are currently the only adopted treatment approaches. Pharmacological therapies and bariatric surgery are still contradictory and, therefore, are only recommended in selected high-risk cases.

Evaluation of epigenetic alterations (mir-126 and mir-155 expression levels) in Mexican children exposed to inorganic arsenic via drinking water

Recently, a great number of epidemiological studies have shown evidence that exposure to inorganic arsenic could have harmful effects on the cardiovascular system of humans. However, the underlying mechanisms through which arsenic induces cardiovascular toxic effects remain unclear. In this regard, epigenetic mechanisms have emerged as a probable connection between environment and disease phenotypes, including cardiovascular diseases. Therefore, this study aimed to evaluate epigenetic changes related to cardiotoxicity (miR-126 and miR-155 expression levels) in children from San Luis Potosi, Mexico exposed to inorganic arsenic. From 2014 to 2015, in a cross-sectional study, children (aged 6-12 years; n = 73) attending public schools at the studied sites were enrolled to take part in this study. Urinary arsenic was used as an exposure biomarker and analyzed by an atomic absorption spectrophotometry technique. On the other hand, miR-126 and miR-155 expression levels were evaluated by qRT-PCR. A mean urinary arsenic level of 30.5 ± 25.5 μg/g of creatinine was found. Moreover, the data showed a significant negative association (p < 0.05) between urinary arsenic concentrations and plasma miR-126 levels. However, an association between urinary arsenic concentrations and plasma miR-155 levels was not found (p > 0.05). In this regard, some investigations have shown an association between diminished plasma miR-126 levels and cardiovascular illnesses. The results found in this study are of concern. However, more similar studies including a larger sample size are necessary in order to clarify the real significance of the data.