Relationship of Circulating miRNAs with Insulin Sensitivity and Associated Metabolic Risk Factors in Humans

Dietary Epigenetic Modulators: Unravelling the Still-Controversial Benefits of miRNAs in Nutrition and Disease

In the context of nutrient-driven epigenetic alterations, food-derived miRNAs can be absorbed into the circulatory system and organs of recipients, especially humans, and potentially contribute to modulating health and diseases. Evidence suggests that food uptake, by carrying exogenous miRNAs (xenomiRNAs), regulates the individual miRNA profile, modifying the redox homeostasis and inflammatory conditions underlying pathological processes, such as type 2 diabetes mellitus, insulin resistance, metabolic syndrome, and cancer. The capacity of diet to control miRNA levels and the comprehension of the unique characteristics of dietary miRNAs in terms of gene expression regulation show important perspectives as a strategy to control disease susceptibility via epigenetic modifications and refine the clinical outcomes. However, the absorption, stability, availability, and epigenetic roles of dietary miRNAs are intriguing and currently the subject of intense debate; additionally, there is restricted knowledge of their physiological and potential side effects. Within this framework, we provided up-to-date and comprehensive knowledge on dietary miRNAs' potential, discussing the latest advances and controversial issues related to the role of miRNAs in human health and disease as modulators of chronic syndromes.

Association between circulating micro-ribonucleic acids and metabolic syndrome in older adults from a population-based study

BACKGROUND AND AIMS

Aging is a major factor in development of chronic non-communicable diseases (NCD). Epigenetic causes are risk factors in NCD development since studies indicate that the expression of micro-ribonucleic acids (miRs) is altered under different clinical conditions. This study aimed to analyze the expression profile of circulating miRs and investigate their association with biomarkers of cardiometabolic risk in older adults living in São Paulo municipality, Brazil.

METHODS

A cross-sectional study was conducted based on the analysis of data from 200 older adults, with a mean age of 69.1 (0.5) years old participating in the ISA-Nutrition. The expression profiles of 21 plasma miRs related to glycemic and lipid metabolism, adiposity, and inflammation were evaluated in relation to cardiometabolic risk. Individuals were distributed into groups according to diagnosis of metabolic syndrome (MetS). The Stata Somersd module was used to calculate confidence intervals for Kendall's tau-a to estimate the correlations among variables.

RESULTS

Differences in the plasma expression were observed in two of the 21 miRs evaluated according to the MetS presence in participants. Individuals with MetS showed higher expression of miR-30a and miR-122 than individuals without MetS.

CONCLUSIONS

Considering that miR-30, and miR-122 were altered due to MetS, these miRs may be potential biomarkers for MetS in older adults.

Circulating MiRNAs Are Associated With Low-grade Systemic Inflammation and Leptin Levels in Older Adults

Inflammaging refers to the low-grade systemic inflammation that occurs with aging present in chronic non-communicable diseases. MicroRNAs (miRNAs) are potential biomarkers for these diseases in older adults. This study aimed to assess the expression of 21 circulating miRNAs and their associations with inflammatory biomarkers in older adults. This cross-sectional study was performed with 200 individuals participating in ISA-Nutrition. The systemic low-grade inflammation score (SIS) was calculated from the plasma concentration of 10 inflammatory biomarkers. Circulating miRNA expression was assessed using the Fluidigm method. Wilcoxon-Mann-Whitney test was employed to determine differences in SIS among groups distributed according to sex and presence of MetS. Spearman's correlation was used to estimate correlations among SIS, leptin levels, miRNA expression, and variables of interest. Analyses were performed using software R version 4.2.3, with a significance level of 0.05. The final sample consisted of 193 individuals with a mean age of 69.1 (SE = 0.5) years, being 64.7% individuals with metabolic syndrome (MetS). Positive correlations were observed between leptin concentration and metabolic risk factors, and leptin concentration was higher in individuals with MetS compared to those without MetS. The expression of 15 circulating miRNAs was negatively correlated with leptin concentration. GLMs showed negative associations between miRNAs (miR-15a, miR-16, miR-223, miR-363, miR-532), leptin, and/or SIS values; and only miR-21 showed positive association with SIS values. The results suggest the presence of peripheral leptin resistance associated with low-grade inflammation and plasma expression of miRNAs in older adults. These findings suggest the potential role of miRNAs as biomarkers for cardiometabolic risk.

Differential expression of adipocyte and myotube extracellular vesicle miRNA cargo in chronic binge alcohol-administered SIV-infected male macaques

Our studies in chronic binge alcohol (CBA) -treated simian immunodeficiency virus (SIV)-infected macaques and in people living with HIV (PLWH) show significant alterations in metabolic homeostasis. CBA promotes a profibrotic phenotype in adipose tissue and skeletal muscle (SKM) and decreases adipose-derived stem cell and myoblast differentiation, making adipose and SKM potential drivers in metabolic dysregulation. Furthermore, we have shown that the differential expression of microRNAs (miRs) in SKM contributes to impaired myoblast differentiation potential. Beyond modulation of intracellular responses, miRs can be transported in extracellular vesicles (EVs) to mediate numerous cellular responses through intercellular and interorgan communication. This study tested the hypothesis that CBA alters concentration and miR cargo of EVs derived from adipocytes and myotubes isolated from SIV-infected male macaques. Fourteen male rhesus macaques received either CBA (2.5 g/kg/day) or sucrose (VEH) for 14.5 months. Three months following the initiation of CBA/VEH, all animals were infected with SIVmac251 and 2.5 months later were initiated on antiretroviral therapy. SKM and adipose tissue samples were collected at the study endpoint (blood alcohol concentration = 0 mM). EVs were isolated by ultracentrifugation of myotube and adipocyte cell culture supernatant. Nanoparticle tracking revealed no differences in concentration or size of particles between VEH and CBA groups. Adipocyte-derived EVs from CBA animals showed decreased miR-let-7a expression (p = 0.03). Myotube-derived EVs from CBA animals had decreased miR-16 (p = 0.04) and increased miR-133a and miR-133b (both p = 0.04) expression. These results indicate that CBA administration differentially regulates EV miR content but does not alter the number of EVs from adipocytes or myotubes. Future studies are warranted to determine the functional relevance of CBA-altered EV miR cargo and their role in intercellular and interorgan communication and metabolic dysregulation.

Circulating microRNA as Biomarkers for Gestational Diabetes Mellitus-A Systematic Review and Meta-Analysis

Gestational diabetes mellitus (GDM) is a severe pregnancy complication for both the woman and the child. Women who suffer from GDM have a greater risk of developing Type 2 diabetes mellitus (T2DM) later in life. Identification of any potential biomarkers for the early prediction of gestational diabetes can help prevent the disease in women with a high risk. Studies show microRNA (miRNA) as a potential biomarker for the early discovery of GDM, but there is a lack of clarity as to which miRNAs are consistently altered in GDM. This study aimed to perform a systematic review and meta-analysis to investigate miRNAs associated with GDM by comparing GDM cases with normoglycemic controls. The systematic review was performed according to PRISMA guidelines with searches in PubMed, Web of Science, and ScienceDirect. The primary search resulted in a total of 849 articles, which were screened according to the prior established inclusion and exclusion criteria. Following the screening of articles, the review was based on the inclusion of 35 full-text articles, which were evaluated for risk of bias and estimates of quality, after which data were extracted and relative values for miRNAs were calculated. A meta-analysis was performed for the miRNA species investigated in three or more studies: MiR-29a, miR-330, miR-134, miR-132, miR-16, miR-223, miR-155, miR-122, miR-17, miR-103, miR-125, miR-210, and miR-222. While some miRNAs showed considerable between-study variability, miR-29a, miR-330, miR-134, miR-16, miR-223, and miR-17 showed significant overall upregulation in GDM, while circulating levels of miR-132 and miR-155 were decreased among GDM patients, suggesting further studies of these as biomarkers for early GDM discovery.

Could Long Non-Coding RNA MEG3 and PTENP1 Interact with miR-21 in the Pathogenesis of Non-Alcoholic Fatty Liver Disease?

NAFLD is the most common cause of chronic liver disease worldwide. The miRNAs and lncRNAs are important endogenous ncRNAs families that can regulate molecular mechanisms. The aim of this study was to analyze the miRNA and lncRNA expression profiles in serum samples of NAFLD patients with different types of hepatosteatosis compared to healthy controls by the qPCR method. A total of180 NAFLD patients and 60 healthy controls were included. miRCURY LNA miRNA miRNome PCR human panel I + II kit and LncProfiler qPCR Array Kit were used to detect miRNA and lncRNA expression, respectively. DIANA miRPath and DIANA-lncBase web servers were used for interaction analysis. As a result, 75 miRNA and 24 lncRNA expression changes were determined. For miRNAs and lncRNAs, 30 and 5 were downregulated and 45 and 19 were upregulated, respectively. hsa-miR-21 was upregulated 2-fold whereas miR-197 was downregulated 0.25-fold. Among lncRNAs, NEAT1 was upregulated 2.9-fold while lncRNA MEG3 was downregulated 0.41-fold. A weak correlation was found between hsa-miR-122 and lncRNA MALAT1. As a conclusion, it is clear that lncRNA-miRNA interaction is involved in the molecular mechanisms of the emergence of NAFLD. The lncRNAs MEG3 and PTENP1 interacted with hsa-miR-21. It was thought that this interaction should be investigated as a biomarker for the development of NAFLD.

Circulating microRNAs Showed Specific Responses according to Metabolic Syndrome Components and Sex of Adults from a Population-Based Study

MicroRNAs (miRNAs) regulate several metabolic pathways and are potential biomarkers for early risk prediction of metabolic syndrome (MetS). Our aim was to evaluate the levels of 21 miRNAs in plasma according to MetS components and sex in adults. We employed a cross-sectional study of 192 adults aged 20 to 59 years old from the 2015 Health Survey of São Paulo with Focus in Nutrition. Data showed reduced levels of miR-16 and miR-363 in women with MetS; however, men with one or more risk factors showed higher levels of miR-let-7c and miR-30a. Individuals with raised waist circumference showed higher levels of miR-let-7c, miR-122, miR-30a, miR-146a, miR-15a, miR-30d and miR-222. Individuals with raised blood pressure had higher miR-30a, miR-122 and miR-30a levels. Plasma levels of four miRNAs (miR-16, miR-363, miR-375 and miR-486) were lower in individuals with low HDL-cholesterol concentrations. In addition, plasma levels of five miRNAs (miR-122, miR-139, miR-let-7c, miR-126 and miR-30a) were increased in individuals with high fasting plasma glucose and/or insulin resistance. Our results suggest that the pattern of miRNA levels in plasma may be a useful early biomarker of cardiometabolic components of MetS and highlight the sex differences in the plasma levels of miRNAs in individuals with MetS.

Maternal Exercise Programs Glucose and Lipid Metabolism and Modulates Hepatic miRNAs in Adult Male Offspring

Detrimental exposures in mothers are recognized as risk factors for the development of metabolic dysfunction in offspring. In contrast, maternal exercise has been reported to be an effective strategy to maintain offspring health. However, the mechanisms underlying the protective effects of maternal exercise on adult offspring metabolic homeostasis are largely unclear. This study aims to investigate whether maternal exercise before and during pregnancy could combat the adverse effects of maternal high-fat diet (HFD) on metabolism in 24-week-old male offspring and to explore the role of miRNAs in mediating the effects. Female C57BL/6 mice were fed with either control diet or HFD 3-week prior to breeding and throughout pregnancy and lactation, among whom half of the HFD-fed mice were submitted to voluntary wheel running training 3-week before and during pregnancy. Male offspring were sedentary and fed with a control diet from weaning to 24 weeks. Body weight, the content of inguinal subcutaneous adipose tissue and perirenal visceral adipose tissue, glucose tolerance, and serum insulin and lipids in offspring were analyzed. Hepatic tissues were collected for transcriptome and miRNA sequencing and reverse transcription-quantitative polymerase chain reaction validation. The results showed that maternal HFD resulted in significant glucose intolerance, insulin resistance, and dyslipidemia in adult offspring, which were negated by maternal exercise. Transcriptome sequencing showed that maternal exercise reversed perinatal HFD-regulated genes in adult offspring, which were enriched in glucose and lipid metabolic-related signaling pathways. At the same time, maternal exercise significantly rescued the changes in the expression levels of 3 hepatic miRNAs in adult offspring, and their target genes were involved in the regulation of cholesterol biosynthesis and epigenetic modification, which may play an important role in mediating the intergenerational metabolic regulation of exercise. Overall, our research pioneered the role of miRNAs in mediating the programming effects of maternal exercise on adult offspring metabolism, which might provide novel insight into the prevention and treatment of metabolic disorders in early life.

MicroRNA Transcriptomics Analysis Identifies Dysregulated Hedgehog Signaling Pathway in a Mouse Model of Acute Intracerebral Hemorrhage Exposed to Hyperglycemia

OBJECTIVE

Hyperglycemia is often observed in the patients after acute stroke. This study aims to elucidate the potential effect and mechanism of hyperglycemia by screening microRNAs expression in intracerebral hemorrhage mice.

METHODS

We employed the collagenase model of intracerebral hemorrhage. Twenty male C57BL/6 mice were used and randomly divided in normo- and hyperglycemic. The hyperglycemia was induced by intraperitoneally injection of 50% of Dextrose (8 mL/kg) 3 hours after intracerebral hemorrhage. The neurologic impairment was investigated by neurologic deficit scale. To study the specific mechanisms of hyperglycemia, microRNAs expression in perihematomal area was investigated by RNA sequencing. MicroRNAs expression in hyperglycemic intracerebral hemorrhage animals were compared normoglycemic mice. Functional annotation analysis was used to indicate potential pathological pathway, underlying observed effects. Finally, polymerase chain reaction validation was administered.

RESULTS

Intraperitoneal injection of dextrose significantly increased blood glucose level. That was associated with aggravation of neurological deficits in hyperglycemic compared to normoglycemic animals. A total of 73 differentially expressed microRNAs were identified via transcriptomics analysis. Bioinformatics analyses showed that these microRNAs were significantly altered in several signaling pathways, of which the hedgehog signaling pathway was regarded as the most potential pathway associated with the effect of hyperglycemia on acute intracerebral hemorrhage. Furthermore, polymerase chain reaction results validated the correlation between microRNAs and hedgehog signaling pathway.

CONCLUSIONS

MicroRNA elevated in hyperglycemia group may be involved in worsening the neurological function via inhibiting the hedgehog signaling, which provides a novel molecular physiological mechanism and lays the foundation for treatment of intracerebral hemorrhage.

Association between circulating microRNAs and the metabolic syndrome in adult populations: A systematic review

BACKGROUND

Circulating microRNAs (miRNAs) are one of the most abundant classes of gene regulatory molecules, and had been associated to the metabolic syndrome, higher BMI, dyslipidemia and diabetes mellitus. In this sense, miRNAs could help to understand the mechanism behind the development of metabolic syndrome.

OBJECTIVE

To determine the relationship between circulating microRNAs and the metabolic syndrome in adult population.

METHODS

We performed a systematic review according to the recommendations of the Cochrane Collaboration and following the PRISMA Statement. The results were grouped for miRNAs levels in MetS and metabolic variables included in MetS and their statistic association with miRNAs levels.

RESULTS

We finally included sixteen studies with a total of 7195 individuals. We found 47 miRNAs reported to be related to metabolic syndrome (p < 0,05) and 98 associated with the metabolic alterations included in its diagnostic (p < 0,05). Forty-nine miRNAs levels were described as relate to insulin resistance, 29 with high triglycerides, 35 with hypertension, 28 with obesity, and 16 miRNAs with cholesterol HDL(p < 0,05). Changes in levels of miR-505-5p, miR-148a-3p, miR-19b-3p, miR-320b, miR-342-3p, miR-197-3p, miR-192-5p, miR-122-5p, miR-103, miR-130a, miR-155-5p and miR-375, were reported as significant in more than one study. The results only included a descriptive synthesis, clinical heterogeneity did not allow a meta-analysis.

CONCLUSION

The findings on the current systematic review suggests a possible relationship between miRNAs with metabolic syndrome and metabolic traits. This association could help to understand the mechanism behind the develop of the metabolic syndrome. However, more studies are necessary for further validation.

Paeonol suppresses lipid formation and promotes lipid degradation in adipocytes

Paeonol can regulate a variety of physiological and pathological processes such as thrombosis, oxidative stress, inflammation and atherosclerosis. However, its potential role and underlying mechanisms in obesity and lipid metabolism remain to be elucidated. In the present study, 3T3-L1 cells were differentiated and collected on days 4, 6 and 8. The expression levels of fatty-acid-binding protein 4 (FABP4) and microRNA (miR)-21 were detected using reverse transcription-quantitative PCR and western blot analyses. Cell viability was assessed using a Cell Counting Kit-8 assay. A miR-21 mimic was constructed and transfected into 3T3-L1 preadipocytes. Adipocyte differentiation was detected using Oil Red O staining. The proteins CD36, glucose transporter 4, peroxisome proliferator-activated receptor γ (PPAR-γ) and adipocyte protein 2 (Ap2) were detected using western blot analysis. The expression levels of FABP4 and miR-21 were increased in differentiated 3T3-L1 cells. Paeonol exhibited no effects on cell activity, whereas it inhibited the expression levels of miR-21 in the 3T3-L1 differentiated adipocytes. Paeonol suppressed the differentiation of 3T3-L1 adipocytes and its effect was partially reversed by the overexpression of miR-21. In addition, paeonol promoted the lipid degradation of 3T3-L1 adipocytes, increased the expression levels of PPAR-γ and Ap2, and suppressed triglyceride synthesis in these cells. These effects were partially reversed by the overexpression of miR-21. In conclusion, the findings of the present study indicated that paeonol may exert protective effects against lipid formation and promote lipid degradation in adipocytes. These data provide evidence of the regulatory effect of paeonol on adipocyte differentiation and highlight its pathological significance.

Systematic bioinformatic analysis of nutrigenomic data of flavanols in cell models of cardiometabolic disease

Flavanol intake positively influences several cardiometabolic risk factors in humans. However, the specific molecular mechanisms of action of flavanols, in terms of gene regulation, in the cell types relevant to cardiometabolic disease have never been systematically addressed. On this basis, we conducted a systematic literature review and a comprehensive bioinformatic analysis of genes whose expression is affected by flavanols in cells defining cardiometabolic health: hepatocytes, adipocytes, endothelial cells, smooth muscle cells and immune cells. A systematic literature search was performed using the following pre-defined criteria: treatment with pure compounds and metabolites (no extracts) at low concentrations that are close to their plasma concentrations. Differentially expressed genes were analyzed using bioinformatics tools to identify gene ontologies, networks, cellular pathways and interactions, as well as transcriptional and post-transcriptional regulators. The systematic literature search identified 54 differentially expressed genes at the mRNA level in in vitro models of cardiometabolic disease exposed to flavanols and their metabolites. Global bioinformatic analysis revealed that these genes are predominantly involved in inflammation, leukocyte adhesion and transendothelial migration, and lipid metabolism. We observed that, although the investigated cells responded differentially to flavanol exposure, the involvement of anti-inflammatory responses is a common mechanism of flavanol action. We also identified potential transcriptional regulators of gene expression: transcriptional factors, such as GATA2, NFKB1, FOXC1 or PPARG, and post-transcriptional regulators: miRNAs, such as mir-335-5p, let-7b-5p, mir-26b-5p or mir-16-5p. In parallel, we analyzed the nutrigenomic effects of flavanols in intestinal cells and demonstrated their predominant involvement in the metabolism of circulating lipoproteins. In conclusion, the results of this systematic analysis of the nutrigenomic effects of flavanols provide a more comprehensive picture of their molecular mechanisms of action and will support the future setup of genetic studies to pave the way for individualized dietary recommendations.

Early-life nutrition and metabolic disorders in later life: a new perspective on energy metabolism

Type 2 diabetes mellitus and metabolic disorders have become an epidemic globally. However, the pathogenesis remains largely unclear and the prevention and treatment are still limited. In addition to environmental factors during adulthood, early life is the critical developmental window with high tissue plasticity, which might be modified by external environmental cues. Substantial evidence has demonstrated the vital role of early-life nutrition in programming the metabolic disorders in later life. In this review, we aim to overview the concepts of fetal programming and investigate the effects of early-life nutrition on energy metabolism in later life and the potential epigenetic mechanism. The related studies published on PubMed database up to March 2020 were included. The results showed that both maternal overnutrition and undernutrition increased the riskes of metabolic disorders in offspring and epigenetic modifications, including DNA methylation, miRNAs, and histone modification, might be the vital mediators. The beneficial effects of early-life lifestyle modifications as well as dietary and nutritional interventions on these deleterious metabolic remolding were initially observed. Overall, characterizing the early-life malnutrition that reshapes metabolic disease trajectories may yield novel targets for early prevention and intervention and provide a new point of view to the energy metabolism.

Characterization of Differentially Expressed Circulating miRNAs in Metabolically Healthy versus Unhealthy Obesity

Obese individuals without metabolic comorbidities are categorized as metabolically healthy obese (MHO). MicroRNAs (miRNAs) may be implicated in MHO. This cross-sectional study explores the link between circulating miRNAs and the main components of metabolic syndrome (MetS) in the context of obesity. We also examine oxidative stress biomarkers in MHO vs. metabolically unhealthy obesity (MUO). We analysed 3536 serum miRNAs in 20 middle-aged obese individuals: 10 MHO and 10 MUO. A total of 159 miRNAs were differentially expressed, of which, 72 miRNAs (45.2%) were higher and 87 miRNAs (54.7%) were lower in the MUO group. In addition, miRNAs related to insulin signalling and lipid metabolism pathways were upregulated in the MUO group. Among these miRNAs, hsa-miR-6796-5p and hsa-miR-4697-3p, which regulate oxidative stress, showed significant correlations with glucose, triglycerides, HbA1c and HDLc. Our results provide evidence of a pattern of differentially expressed miRNAs in obesity according to MetS, and identify those related to insulin resistance and lipid metabolism pathways.

High serum miR-421 is associated with metabolic dysregulation and inflammation in patients with metabolic syndrome

Aim: To explore the association of circulating miRNAs with adiposity, metabolic status and inflammatory biomarkers in patients with metabolic syndrome (MetS). Methods: Serum levels of 372 miRNAs were measured in patients with (n = 6) and without MetS (n = 6) by quantitative PCR array, and dysregulated miRNAs were validated in a larger cohort (MetS, n = 89; non-MetS, n = 144). Results: In the screening study, seven miRNAs were dysregulated in patients with MetS, and miR-421 remained increased in the validation study. miR-421 was associated with a high risk of MetS and insulin resistance and hypertension and correlated with glycated hemoglobin, triacylglycerols, high-sensitivity CRP, IL-6, resistin and adiponectin (p < 0.05). Conclusion: Circulating miR-421 is a potential biomarker for insulin resistance, metabolic dysregulation and inflammatory status in patients with MetS.

High expression levels of circulating microRNA-122 and microRNA-222 are associated with obesity in children with Mayan ethnicity

OBJECTIVES

High expression levels (HELs) of microRNA-122 (miR-122) or microRNA-222 (miR-222) have been associated with insulin resistance (IR), which leads to the development of obesity. The association between HELs of circulating miR-122 and miR-222 and the risk of obesity was evaluated in Mexican school-aged children, where childhood obesity is the primary cause of morbidity.

METHODS

Anthropometric data, biochemical parameters, and caloric intake were obtained in 50 children with obesity and 49 children with normal weight. The expression of circulating miR-122 and miR-222 was measured by quantitative real-time polymerase chain reaction amplification. Data were analyzed using Student t test, Pearson correlation coefficient, associations with chi-square, and multiple linear and logistic regressions with SPSS software v.23.

RESULTS

The mean relative expression for miR-122 and miR-222 was 0.33 and 5.65, respectively, for children with obesity and 0.22 and 3.16, respectively, for children with normal weight. The expression of miR-122 and miR-222 was 1.47 and 1.78-fold higher, respectively, in children with obesity (P = 0.001 and P = 0.025). HELs of both miR-122 and miR-222 were associated with body mass index (BMI), waist to height ratio (WHR), fat percentage, serum high-density lipid levels, triglycerides (TGs), and metabolic index (MI) (P < .001).

CONCLUSIONS

The HELs of circulating miR-122 conferred a 3.85-fold increase in the risk for obesity, whereas the HELs of both miR-122 and miR-222 conferred a 3.11-fold increase in the risk for obesity, which were also associated with higher anthropometric or biochemical parameters, such as BMI, WHR, fat percentage, serum high-density lipid levels, TGs, and MI, in Mayan children.

Type 2 Diabetes in Youth: the Role of Early Life Exposures

PURPOSE OF REVIEW

This review examines the impact of early life exposures on glucose metabolism in the offspring and explores potential metabolic mechanisms leading to type 2 diabetes in childhood.

RECENT FINDINGS

One in five adolescents is diagnosed with prediabetes. Recent studies have elucidated the impact of early exposures such as maternal diabetes, but also hyperglycemia below the threshold of gestational diabetes, obesity, hyperlipidemia, and paternal obesity on the future metabolic health of the offspring. Mechanisms affecting the developmental programing of offspring toward type 2 diabetes include epigenetic modifications, alterations in stem cell differentiation, metabolome and microbiome variation, immune dysregulation, and neonatal nutrition. The risk of type 2 diabetes in offspring is increased not only by diabetes exposure in utero but also by exposure to a heterogeneous milieu of factors that accompany maternal obesity that provoke a vicious cycle of metabolic disease. The key period for intervention to prevent type 2 diabetes is within the first 1000 days of life.

Identifying potential functional lncRNAs in metabolic syndrome by constructing a lncRNA-miRNA-mRNA network

The metabolic syndrome (MS) is a cluster of interrelated risk factors including diabetes mellitus, abdominal obesity, high cholesterol, and hypertension, which can significantly increase mortality and disability. Accumulating evidence suggest that long non-coding RNAs (lncRNAs) are involved in the pathogenesis of human metabolic diseases. However, little is known about the regulatory role of lncRNAs in MS. In this work, we proposed a method for identifying potential MS-associated lncRNAs by constructing an lncRNA-miRNA-mRNA network (LMMN). Firstly, we constructed LMMN by integrating MS-associated genes, miRNA-mRNA interactions, miRNA-lncRNA interactions and mRNA/miRNA expression profiles in patients with MS. Then, we predicted potential MS-associated lncRNAs based on the topological properties of LMMN. As a result, we identified XIST as the most important lncRNA in LMMN. Furthermore, we focused on XIST/miR-214-3p and mir-181a-5p/PTEN axis and validated their expression in MS using real-time quantitative polymerase chain reaction (RT-qPCR). The RT-qPCR results showed that the expression of XIST and PTEN was significantly decreased (P < 0.05) while the expression of miR-214-3p was significantly increased (P < 0.05) in peripheral blood mononuclear cells (PBMCs) of patients with MS, compared with healthy controls. In addition, correlation analysis showed that XIST was negatively correlated with serum C peptide and PTEN was positively correlated with BMI of MS patients. Our findings provided new evidence for further exploring the regulatory role of XIST and other lncRNAs in MS.

Principal component analysis of blood microRNA datasets facilitates diagnosis of diverse diseases

Early, ideally pre-symptomatic, recognition of common diseases (e.g., heart disease, cancer, diabetes, Alzheimer’s disease) facilitates early treatment or lifestyle modifications, such as diet and exercise. Sensitive, specific identification of diseases using blood samples would facilitate early recognition. We explored the potential of disease identification in high dimensional blood microRNA (miRNA) datasets using a powerful data reduction method: principal component analysis (PCA). Using Qlucore Omics Explorer (QOE), a dynamic, interactive visualization-guided bioinformatics program with a built-in statistical platform, we analyzed publicly available blood miRNA datasets from the Gene Expression Omnibus (GEO) maintained at the National Center for Biotechnology Information at the National Institutes of Health (NIH). The miRNA expression profiles were generated from real time PCR arrays, microarrays or next generation sequencing of biologic materials (e.g., blood, serum or blood components such as platelets). PCA identified the top three principal components that distinguished cohorts of patients with specific diseases (e.g., heart disease, stroke, hypertension, sepsis, diabetes, specific types of cancer, HIV, hemophilia, subtypes of meningitis, multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer’s disease, mild cognitive impairment, aging, and autism), from healthy subjects. Literature searches verified the functional relevance of the discriminating miRNAs. Our goal is to assemble PCA and heatmap analyses of existing and future blood miRNA datasets into a clinical reference database to facilitate the diagnosis of diseases using routine blood draws.

Nutritional genomics, inflammation and obesity

The Human Genome Project has significantly broadened our understanding of the molecular aspects regulating the homeostasis and the pathophysiology of different clinical conditions. Consequently, the field of nutrition has been strongly influenced by such improvements in knowledge - especially for determining how nutrients act at the molecular level in different conditions, such as obesity, type 2 diabetes, cardiovascular disease, and cancer. In this manner, characterizing how the genome influences the diet and vice-versa provides insights about the molecular mechanisms involved in chronic inflammation-related diseases. Therefore, the present review aims to discuss the potential application of Nutritional Genomics to modulate obesity-related inflammatory responses. Arch Endocrinol Metab. 2020;64(3):205-22.

Association of circulating miR-20a, miR-27a, and miR-126 with non-alcoholic fatty liver disease in general population

Non-alcoholic fatty liver disease (NAFLD) is closely associated with obesity, metabolic syndrome, and type II diabetes mellitus. Recently, circulating microRNAs (miRNAs) have been proposed as useful disease biomarkers. We examined whether circulating miRNAs, such as miR-20a, miR-27a, and miR-126, were useful biomarkers for NAFLD. We conducted a cross-sectional analysis of 527 subjects aged 39 years or older who had undergone a health examination in the Yakumo Study. Of the residents, 92 were diagnosed with NAFLD using a registered medical sonographer. Serum miR-20a, miR-27a and miR-126 levels were measured by quantitative real-time PCR. We then calculated the odds ratios for serum miRNA level changes according to the severity of NAFLD using normal liver status as the reference group. Serum levels of miR-20a and 27a, but not miR-126, were significantly lower in NAFLD subjects than normal subjects. Serum miR-20a and miR-27a levels were significantly lower in both male and female severe NAFLD subjects. Logistic regression analysis showed a significant relationship between low circulating miR-20a and 27a levels and severe NAFLD. Down-regulated circulating miR-20a and 27a levels were significantly associated with severe NAFLD in the general population. Circulating miR-20a and miR-27a may be useful biomarkers for severe NAFLD.

Plasma Protein and MicroRNA Biomarkers of Insulin Resistance: A Network-Based Integrative -Omics Analysis

Although insulin resistance (IR) is a key pathophysiologic condition underlying various metabolic disorders, impaired cellular glucose uptake is one of many manifestations of metabolic derangements in the human body. To study the systems-wide molecular changes associated with obesity-dependent IR, we integrated information on plasma proteins and microRNAs in eight obese insulin-resistant (OIR, HOMA-IR > 2.5) and nine lean insulin-sensitive (LIS, HOMA-IR < 1.0) normoglycemic males. Of 374 circulating miRNAs we profiled, 65 species increased and 73 species decreased in the OIR compared to the LIS subjects, suggesting that the overall balance of the miRNA secretome is shifted in the OIR subjects. We also observed that 40 plasma proteins increased and 4 plasma proteins decreased in the OIR subjects compared to the LIS subjects, and most proteins are involved in metabolic and endocytic functions. We used an integrative -omics analysis framework called iOmicsPASS to link differentially regulated miRNAs with their target genes on the TargetScan map and the human protein interactome. Combined with tissue of origin information, the integrative analysis allowed us to nominate obesity-dependent and obesity-independent protein markers, along with potential sites of post-transcriptional regulation by some of the miRNAs. We also observed the changes in each -omics platform that are not linked by the TargetScan map, suggesting that proteins and microRNAs provide orthogonal information for the progression of OIR. In summary, our integrative analysis provides a network of elevated plasma markers of OIR and a global shift of microRNA secretome composition in the blood plasma.

Quantum Dot Based Nano-Biosensors for Detection of Circulating Cell Free miRNAs in Lung Carcinogenesis: From Biology to Clinical Translation

Lung cancer is the most frequently occurring malignancy and the leading cause of cancer-related death for men in our country. The only recommended screening method is clinic based low-dose computed tomography (also called a low-dose CT scan, or LDCT). However, the effect of LDCT on overall mortality observed in lung cancer patients is not statistically significant. Over-diagnosis, excessive cost, risks associated with radiation exposure, false positive results and delay in the commencement of the treatment procedure questions the use of LDCT as a reliable technique for population-based screening. Therefore, identification of minimal-invasive biomarkers able to detect malignancies at an early stage might be useful to reduce the disease burden. Circulating nucleic acids are emerging as important source of information for several chronic pathologies including lung cancer. Of these, circulating cell free miRNAs are reported to be closely associated with the clinical outcome of lung cancer patients. Smaller size, sequence homology between species, low concentration and stability are some of the major challenges involved in characterization and specific detection of miRNAs. To circumvent these problems, synthesis of a quantum dot based nano-biosensor might assist in sensitive, specific and cost-effective detection of differentially regulated miRNAs. The wide excitation and narrow emission spectra of these nanoparticles result in excellent fluorescent quantum yields with a broader color spectrum which make them ideal bio-entities for fluorescence resonance energy transfer (FRET) based detection for sequential or simultaneous study of multiple targets. In addition, photo-resistance and higher stability of these nanoparticles allows extensive exposure and offer state-of-the art sensitivity for miRNA targeting. A major obstacle for integrating QDs into clinical application is the QD-associated toxicity. However, the use of non-toxic shells along with surface modification not only overcomes the toxicity issues, but also increases the ability of QDs to quickly detect circulating cell free miRNAs in a non-invasive mode. The present review illustrates the importance of circulating miRNAs in lung cancer diagnosis and highlights the translational prospects of developing QD-based nano-biosensor for rapid early disease detection.

Changes in Blood microRNA Expression and Early Metabolic Responsiveness 21 Days Following Bariatric Surgery

Background: Early metabolic responses following bariatric surgery appear greater than expected given the initial weight loss and coincide with improvement in diabetes. We hypothesized that small non-coding microRNA changes might contribute to regulating mechanisms for metabolic changes and weight loss in patients with severe obesity and diabetes. Methods: Twenty-nine type 2 patients with severe obesity (mean BMI 46.2 kg/m²) and diabetes underwent Roux-en-Y gastric bypass (RYGB) surgery. Clinical measurements and fasting blood samples were taken preoperatively and at day 21 postoperatively. Normalization of fasting glucose and HbA1c following bariatric surgery (short-term diabetes remission) was defined as withdrawal of anti-diabetic medication and fasting glucose < 100 mg/dL (5.6 mmol/L) or HbA1c < 6.0%. MicroRNA expression was determined by quantitative polymerase chain reaction and tested for significant changes after surgery. Results: BMI decreased by 3.8 kg/m² 21 days postoperatively. Eighteen of 29 RYGB (62%) had short-term diabetes remission. Changes from pre- to post-surgery in 32 of 175 microRNAs were nominally significant (p < 0.05). Following multiple comparison adjustment, changes in seven microRNAs remained significant: miR-7-5p, let-7f-5p, miR-15b-5p, let-7i-5p, miR-320c, miR-205-5p, and miR-335-5p. Four pathways were over-represented by these seven microRNAs, including diabetes and insulin resistance pathways. Conclusion: Seven microRNAs showed significant changes 21 days after bariatric surgery. Functional pathways of the altered microRNAs were associated with diabetes-, pituitary-, and liver-related disease, with expression in natural killer cells, and pivotal intestinal pathology suggesting possible mechanistic roles in early diabetes responses following bariatric surgery.