Explore the vast range of titles available.

Summary Recent evidence demonstrates that serum levels of specific miRNAs significantly change with age. The ability of circulating sncRNAs to act as signaling molecules and regulate a broad spectrum of cellular functions implicates them as key players in the aging process. To discover circulating sncRNAs that impact aging in the long-lived Ames dwarf mice, we conducted deep sequencing of small RNAs extracted from serum of young and old mice. Our analysis showed genotype-specific changes in the circulating levels of 21 miRNAs during aging [genotype-by-age interaction (GbA)]. Genotype-by-age miRNAs showed four distinct expression patterns and significant overtargeting of transcripts involved in age-related processes. Functional enrichment analysis of putative and validated miRNA targets highlighted cellular processes such as tumor suppression, anti-inflammatory response, and modulation of Wnt, insulin, mTOR, and MAPK signaling pathways, among others. The comparative analysis of circulating GbA miRNAs in Ames mice with circulating miRNAs modulated by calorie restriction (CR) in another long-lived mouse suggests CR-like and CR-independent mechanisms contributing to longevity in the Ames mouse. In conclusion, we showed for the first time a signature of circulating miRNAs modulated by age in the long-lived Ames mouse.

Objective. We explored the relationships among microRNAs (miRNAs) and SFRP4, as they relate to adipose tissue functions including lipolysis, glucose and glycerol turnover, and insulin sensitivity. Methods. Abdominal adipose tissue (AbdAT) levels of thirteen microRNAs (miRNAs), SFRP4, and VEGF in lean nondiabetic subjects (n=7), subjects with obesity (n=5), and subjects with obesity and type 2 diabetes (T2DM) (n=5) were measured by qPCR. Insulin sensitivity was measured by the euglycemic-hyperinsulinemic clamp. Osmium fixation and Coulter counting were used for adipocyte sizing. Data were analyzed using generalized linear models that adjusted for age, gender, and ethnicity. Results. AbdAT miR-24, miR-30d, and miR-146a were elevated in subjects with obesity (P<0.05) and T2DM (P<0.1) and positively correlated with measures of percent body fat by DXA (rmiR.24=0.894, rmiR.146a=0.883, P<0.05), and AbdAT SFRP4 (rmiR.30=0.93, rmiR.146a=0.88, P<0.05). These three miRNAs additionally correlated among themselves (rmiR.24~miR.146a=0.90, rmiR.30~miR.146a=0.85, P<0.01). Conclusions. This study suggests a novel association between the elevated levels of miRNAs miR-24, miR-30d, and miR-146a (apparently coregulated) and the level of SFRP4 transcript in AbdAT of subjects with obesity and T2DM. These molecules might be part of a regulatory loop involved in AbdAT remodeling/adiposity and systemic insulin resistance. This trial is registered with NCT00704197.

The clinical presentation of diabetes sometimes overlaps, contributing to ambiguity in the diagnosis. Thus, circulating pancreatic islet-enriched microRNAs (miRNAs) might be useful biomarkers of β-cell injury/dysfunction that would allow more accurate subtyping of diabetes. We measured plasma levels of selected miRNAs in subjects with prediabetes (n = 12), type 2 diabetes (T2D, n = 31), latent autoimmune diabetes of adults (LADA, n = 6) and type 1 diabetes (T1D, n = 16) and compared them to levels in healthy control subjects (n = 27). The study was conducted at the Translational Research Institute for Metabolism and Diabetes (TRI-MD), Florida Hospital. MiRNAs including miR-375 (linked to β-cell injury), miR-21 (associated with islet inflammation), miR-24.1, miR-30d, miR-34a, miR-126, miR-146, and miR-148a were significantly elevated in subjects with various forms of diabetes compared to healthy controls. Levels of several miRNAs were significantly correlated with glucose responses during oral glucose tolerance testing, HbA 1c , β-cell function, and insulin resistance in healthy controls, prediabetes, and T2D. These data suggest that miRNAs linked to β-cell injury and islet inflammation might be useful biomarkers to distinguish between subtypes of diabetes. This information could be used to predict progression of the disease, guide selection of optimal therapy and monitor responses to interventions, thus improving outcomes in patients with diabetes.

The purpose of this study was to define the proteomic and phosphoproteomic landscape of circulating extracellular vesicles (EVs) in people with normal glucose tolerance (NGT), prediabetes (PDM), and diabetes (T2DM). Archived serum samples from 30 human subjects (n = 10 per group, ORIGINS study, NCT02226640) were used. EVs were isolated using EVtrap®. Mass spectrometry-based methods were used to detect the global EV proteome and phosphoproteome. Differentially expressed features, correlation, enriched pathways, and enriched tissue-specific protein sets were identified using custom R scripts. Phosphosite-centric analyses were conducted using directPA and PhosR software packages. A total of 2372 unique EV proteins and 716 unique EV phosphoproteins were identified among all samples. Unsupervised clustering of the differentially expressed (fold change ≥ 2, p < 0.05, FDR < 0.05) proteins and, particularly, phosphoproteins showed excellent discrimination among the three groups. CDK1 and PKCδ appear to drive key upstream phosphorylation events that define the phosphoproteomic signatures of PDM and T2DM. Circulating EVs from people with diabetes carry increased levels of specific phosphorylated kinases (i.e., AKT1, GSK3B, LYN, MAP2K2, MYLK, and PRKCD) and could potentially distribute activated kinases systemically. Among characteristic changes in the PDM and T2DM EVs, “integrin switching” appeared to be a central feature. Proteins involved in oxidative phosphorylation (OXPHOS), known to be reduced in various tissues in diabetes, were significantly increased in EVs from PDM and T2DM, which suggests that an abnormally elevated EV-mediated secretion of OXPHOS components may underlie the development of diabetes. A highly enriched signature of liver-specific markers among the downregulated EV proteins and phosphoproteins in both PDM and T2DM groups was also detected. This suggests that an alteration in liver EV composition and/or secretion may occur early in prediabetes. This study identified EV proteomic and phosphoproteomic signatures in people with prediabetes and T2DM and provides novel insight into the pathobiology of diabetes.

The coronavirus disease 2019 (COVID-19) pandemic, caused by the SARS-CoV-2 virus, is wreaking havoc around the world. Considering that extracellular vesicles (EVs) released from SARS-CoV-2 infected cells might play a role in a viremic phase contributing to disease progression and that standard methods for EV isolation have been reported to co-isolate viral particles, we would like to recommend the use of heightened laboratory safety measures during the isolation of EVs derived from SARS-CoV-2 infected tissue and blood from COVID-19 patients. Research needs to be conducted to better understand the role of EVs in SARS-CoV-2 infectivity, disease progression, and transmission. EV isolation procedures should include approaches for protection from SARS-CoV-2 contamination. We recommend the EV and virology scientific communities develop collaborative projects where relationships between endogenous EVs and potentially lethal enveloped viruses are addressed to better understand the risks and pathobiology involved.

Circulating exosomes in the blood are promising tools for biomarker discovery in cancer. Due to their heterogeneity, different isolation methods may enrich distinct exosome cargos generating different omic profiles. In this study, we evaluated the effects of plasma exosome isolation methods on detectable multi-omic profiles in patients with non-small cell lung cancer (NSCLC), castration-resistant prostate cancer (CRPC), and healthy controls, and developed an algorithm to quantify exosome enrichment. Plasma exosomes were isolated from CRPC (n = 10), NSCLC (n = 14), and healthy controls (n = 10) using three different methods: size exclusion chromatography (SEC), lectin binding, and T-cell immunoglobulin domain and mucin domain-containing protein 4 (TIM4) binding. Molecular profiles were determined by mass spectrometry of extracted exosome fractions. Enrichment analysis of uniquely detected molecules was performed for each method with MetaboAnalyst. The exosome enrichment index (EEI) scores methods based on top differential molecules between patient groups. The lipidomic analysis detected 949 lipids using exosomes from SEC, followed by 246 from lectin binding and 226 from TIM4 binding. The detectable metabolites showed SEC identifying 191 while lectin binding and TIM4 binding identified 100 and 107, respectively. When comparing uniquely detected molecules, different methods showed preferential enrichment of different sets of molecules with SEC enriching the greatest diversity. Compared to controls, SEC identified 28 lipids showing significant difference in NSCLC, while only 1 metabolite in NSCLC and 5 metabolites in CRPC were considered statistically significant (FDR < 0.1). Neither lectin-binding- nor TIM4-binding-derived exosome lipids or metabolites demonstrated significant differences between patient groups. We observed the highest EEI from SEC in lipids (NSCLC: 871.33) which was also noted in metabolites. These results support that the size exclusion method of exosome extraction implemented by SBI captures more heterogeneous exosome populations. In contrast, lectin-binding and TIM4-binding methods bind surface glycans or phosphatidylserine moieties of the exosomes. Overall, these findings suggest that specific isolation methods select subpopulations which may significantly impact cancer biomarker discovery.

Reduced inflammation, increased insulin sensitivity, and protection against cancer are shared between humans and mice with GH/IGF1 deficiency. Beyond hormone levels, miRNAs are important regulators of metabolic changes associated with healthy aging. We hypothesized that GH deficiency in humans alters the abundance of circulating miRNAs and that a subset of those miRNAs may overlap with those found in GH‐deficient mice. In this study, subjects with untreated congenital isolated GH deficiency (IGHD; n = 23) and control subjects matched by age and sex (n = 23) were recruited and serum was collected for miRNA sequencing. Serum miRNAs from young (6 month) and old (22 month) Ames dwarf (df/df) mice with GH deficiency and their WT littermates (n = 5/age/genotype group) were used for comparison. We observed 14 miRNAs regulated with a genotype by age effect and 19 miRNAs regulated with a genotype effect independent of age in serum of IGHD subjects. These regulated miRNAs are known for targeting pathways associated with longevity such as mTOR, insulin signaling, and FoxO. The aging function was overrepresented in IGHD individuals, mediated by hsa‐miR‐31, hsa‐miR‐146b, hsa‐miR‐30e, hsa‐miR‐100, hsa‐miR‐181b‐2, hsa‐miR‐195, and hsa‐miR‐181b‐1, which target the FoxO and mTOR pathways. Intriguingly, miR‐181b‐5p, miR‐361‐3p, miR‐144‐3p, and miR‐155‐5p were commonly regulated in the serum of humans and GH‐deficient mice. In vitro assays confirmed target genes for the main up‐regulated miRNAs, suggesting miRNAs regulated in IGHD individuals can regulate the expression of age‐related genes. These findings indicate that systemic miRNAs regulated in IGHD individuals target pathways involved in aging in both humans and mice. In this study we investigated serum regulated miRNAs in GH deficient humans and mice. We observed that some miRNAs are commonly regulated in both species. These miRNAs target pathways involved in aging in both humans and mice.

Crohn’s disease (CD) and rheumatoid arthritis (RA) are immune mediated inflammatory diseases. Several studies indicate a role for microRNAs (miRNAs) in the pathogenesis of a variety of autoimmune diseases, including CD and RA. Our study’s goal was to investigate circulating miRNAs in CD and RA patients to identify potential new biomarkers for early detection and personalized therapeutic approaches for autoimmune diseases. For this study, subjects with CD (n = 7), RA (n = 8) and healthy controls (n = 7) were recruited, and plasma was collected for miRNA sequencing. Comparison of the expression patterns of miRNAs between CD and healthy patients identified 99 differentially expressed miRNAs. Out of these miRNAs, 4 were down regulated, while 95 were up regulated. Comparison of miRNAs between RA and healthy patients identified 57 differentially expressed miRNAs. Out of those, 12 were down regulated, while 45 were up regulated. For all the miRNAs down regulated in CD and RA patients, 420 GO terms for biological processes were similarly regulated between both groups. Therefore, the identification of new plasma miRNAs allows the emergence of new biomarkers that can assist in the diagnosis and treatment of CD and RA.