High miR-126-3p levels associated with cardiovascular events in a general population

BACKGROUND

Endothelial dysfunction is a forerunner of atherosclerosis, leading to cardiovascular disease, and albuminuria is a marker of endothelial dysfunction. Circulating levels of microRNAs are emerging as potential biomarkers for cardiovascular disease. Here we estimate the predictive value of a plasma microRNAs signature associated with albuminuria in the incidence of cardiovascular events.

METHODS

Plasma microRNAs quantified in hypertensive patients by next generation sequencing were validated in a cohort of patients and controls by real-time quantitative PCR. The microRNAs found to be associated with albuminuria were analysed for their prognostic value in predicting cardiovascular events incidence on a retrospective, population-based study (Hortega Study), using Cox proportional hazard models.

RESULTS

A plasma microRNA profile was identified in the discovery cohort (n = 48) associated with albuminuria and three microRNAs (miR-126-3p, miR-1260b and miR-374a-5p) were confirmed in the validation cohort (n = 98). The microRNA signature discriminates urinary albumin excretion at baseline (n = 1025), and predicts the incidence of cardiovascular events and coronary heart disease and stroke in a general population retrospective study within a 14-year follow-up (n = 926). High miR-126-3p levels were associated with a shorter time free of both cardiovascular events (HR=1.48, (1.36-1.62), p < 0.0001), as well as coronary artery disease and stroke combined (HR=2.49, (2.19-2.83), p < 0.0001).

CONCLUSIONS

An increased plasma microRNAs profile was identified in hypertensive patients with albuminuria. Increased miR-126-3p suggest it may serve as a prognostic marker for cardiovascular events in a long-term general population. Further studies will assess the potential role of miR-126-3p as a guide for the status of endothelial dysfunction.

Rab3A/Rab27A System Silencing Ameliorates High Glucose-Induced Injury in Podocytes

Diabetic nephropathy is a major complication in diabetic patients. Podocytes undergo loss and detachment from the basal membrane. Intra- and intercellular communication through exosomes are key processes for maintaining function, and the Rab3A/Rab27A system is an important counterpart. Previously, we observed significant changes in the Rab3A/Rab27A system in podocytes under glucose overload, demonstrating its important role in podocyte injury. We investigated the implication of silencing the Rab3A/Rab27A system in high glucose-treated podocytes and analysed the effect on differentiation, apoptosis, cytoskeletal organisation, vesicle distribution, and microRNA expression in cells and exosomes. For this, we subjected podocytes to high glucose and transfection through siRNAs, and we isolated extracellular vesicles and performed western blotting, transmission electron microscopy, RT-qPCR, immunofluorescence and flow cytometry assays. We found that silencing RAB3A and RAB27A generally leads to a decrease in podocyte differentiation and cytoskeleton organization and an increase in apoptosis. Moreover, CD63-positive vesicles experienced a pattern distribution change. Under high glucose, Rab3A/Rab27A silencing ameliorates some of these detrimental processes, suggesting a differential influence depending on the presence or absence of cellular stress. We also observed substantial expression changes in miRNAs that were relevant in diabetic nephropathy upon silencing and glucose treatment. Our findings highlight the Rab3A/Rab27A system as a key participant in podocyte injury and vesicular traffic regulation in diabetic nephropathy.

Plasma Exosomal Non-Coding RNA Profile Associated with Renal Damage Reveals Potential Therapeutic Targets in Lupus Nephritis

Despite considerable progress in our understanding of systemic lupus erythematosus (SLE) pathophysiology, patient diagnosis is often deficient and late, and this has an impact on disease progression. The aim of this study was to analyze non-coding RNA (ncRNA) packaged into exosomes by next-generation sequencing to assess the molecular profile associated with renal damage, one of the most serious complications of SLE, to identify new potential targets to improve disease diagnosis and management using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The plasma exosomes had a specific ncRNA profile associated with lupus nephritis (LN). The three ncRNA types with the highest number of differentially expressed transcripts were microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and piwi-interacting RNAs (piRNAs). We identified an exosomal 29-ncRNA molecular signature, of which 15 were associated only with LN presence; piRNAs were the most representative, followed by lncRNAs and miRNAs. The transcriptional regulatory network showed a significant role for four lncRNAs (LINC01015, LINC01986, AC087257.1 and AC022596.1) and two miRNAs (miR-16-5p and miR-101-3p) in network organization, targeting critical pathways implicated in inflammation, fibrosis, epithelial-mesenchymal transition and actin cytoskeleton. From these, a handful of potential targets, such as transforming growth factor-β (TGF-β) superfamily binding proteins (activin-A, TGFB receptors, etc.), WNT/β-catenin and fibroblast growth factors (FGFs) have been identified for use as therapeutic targets of renal damage in SLE.

Biofluid Specificity of Long Non-Coding RNA Profile in Hypertension: Relevance of Exosomal Fraction

Non-coding RNA (ncRNA)-mediated targeting of various genes regulates the molecular mechanisms of the pathogenesis of hypertension (HTN). However, very few circulating long ncRNAs (lncRNAs) have been reported to be altered in essential HTN. The aim of our study was to identify a lncRNA profile in plasma and plasma exosomes associated with urinary albumin excretion in HTN by next-generation sequencing and to assess biological functions enriched in response to albuminuria using GO and KEGG analysis. Plasma exosomes showed higher diversity and fold change of lncRNAs than plasma, and low transcript overlapping was found between the two biofluids. Enrichment analysis identified different biological pathways regulated in plasma or exosome fraction, which were implicated in fatty acid metabolism, extracellular matrix, and mechanisms of sorting ncRNAs into exosomes, while plasma pathways were implicated in genome reorganization, interference with RNA polymerase, and as scaffolds for assembling transcriptional regulators. Our study found a biofluid specific lncRNA profile associated with albuminuria, with higher diversity in exosomal fraction, which identifies several potential targets that may be utilized to study mechanisms of albuminuria and cardiovascular damage.

Mesenchymal Stem Cell-Derived Extracellular Vesicles as Non-Coding RNA Therapeutic Vehicles in Autoimmune Diseases

Autoimmune diseases (ADs) are characterized by the activation of the immune system against self-antigens. More common in women than in men and with an early onset, their incidence is increasing worldwide, and this, combined with their chronic nature, is contributing to an enlarged medical and economic burden. Conventional immunosuppressive agents are designed to alleviate symptoms but do not constitute an effective therapy, highlighting a need to develop new alternatives. In this regard, mesenchymal stem cells (MSCs) have demonstrated powerful immunosuppressive and regenerative effects. MSC-derived extracellular vesicles (MSC-EVs) have shown some advantages, such as less immunogenicity, and are proposed as novel therapies for ADs. In this review, we summarize current perspectives on therapeutic options for ADs based on MSCs and MSC-EVs, focusing particularly on their mechanism of action exerted through their non-coding RNA (ncRNA) cargo. A complete state-of-the-art review was performed, centralized on some of the most severe ADs (rheumatoid arthritis, autoimmune type 1 diabetes mellitus, and systemic lupus erythematosus), giving evidence that a promising field is evolving to overcome the current knowledge and provide new therapeutic possibilities centered on MSC-EVs and their role as ncRNA delivery vehicles for AD gene therapy.

Exosomal and Plasma Non-Coding RNA Signature Associated with Urinary Albumin Excretion in Hypertension

Non-coding RNA (ncRNA), released into circulation or packaged into exosomes, plays important roles in many biological processes in the kidney. The purpose of the present study is to identify a common ncRNA signature associated with early renal damage and its related molecular pathways. Three individual libraries (plasma and urinary exosomes, and total plasma) were prepared from each hypertensive patient (with or without albuminuria) for ncRNA sequencing analysis. Next, an RNA-based transcriptional regulatory network was constructed. The three RNA biotypes with the greatest number of differentially expressed transcripts were long-ncRNA (lncRNA), microRNA (miRNA) and piwi-interacting RNA (piRNAs). We identified a common 24 ncRNA molecular signature related to hypertension-associated urinary albumin excretion, of which lncRNAs were the most representative. In addition, the transcriptional regulatory network showed five lncRNAs (LINC02614, BAALC-AS1, FAM230B, LOC100505824 and LINC01484) and the miR-301a-3p to play a significant role in network organization and targeting critical pathways regulating filtration barrier integrity and tubule reabsorption. Our study found an ncRNA profile associated with albuminuria, independent of biofluid origin (urine or plasma, circulating or in exosomes) that identifies a handful of potential targets, which may be utilized to study mechanisms of albuminuria and cardiovascular damage.

Small Rab GTPases in Intracellular Vesicle Trafficking: The Case of Rab3A/Raphillin-3A Complex in the Kidney

Small Rab GTPases, the largest group of small monomeric GTPases, regulate vesicle trafficking in cells, which are integral to many cellular processes. Their role in neurological diseases, such as cancer and inflammation have been extensively studied, but their implication in kidney disease has not been researched in depth. Rab3a and its effector Rabphillin-3A (Rph3A) expression have been demonstrated to be present in the podocytes of normal kidneys of mice rats and humans, around vesicles contained in the foot processes, and they are overexpressed in diseases with proteinuria. In addition, the Rab3A knockout mice model induced profound cytoskeletal changes in podocytes of high glucose fed animals. Likewise, RphA interference in the Drosophila model produced structural and functional damage in nephrocytes with reduction in filtration capacities and nephrocyte number. Changes in the structure of cardiac fiber in the same RphA-interference model, open the question if Rab3A dysfunction would produce simultaneous damage in the heart and kidney cells, an attractive field that will require attention in the future.

Supervised Analysis for Phenotype Identification: The Case of Heart Failure Ejection Fraction Class

Artificial Intelligence is creating a paradigm shift in health care, with phenotyping patients through clustering techniques being one of the areas of interest.

OBJECTIVE

To develop a predictive model to classify heart failure (HF) patients according to their left ventricular ejection fraction (LVEF), by using available data from Electronic Health Records (EHR).

SUBJECTS AND METHODS

2854 subjects over 25 years old with a diagnosis of HF and LVEF, measured by echocardiography, were selected to develop an algorithm to predict patients with reduced EF using supervised analysis. The performance of the developed algorithm was tested in heart failure patients from Primary Care. To select the most influentual variables, the LASSO algorithm setting was used, and to tackle the issue of one class exceeding the other one by a large amount, we used the Synthetic Minority Oversampling Technique (SMOTE). Finally, Random Forest (RF) and XGBoost models were constructed.

RESULTS

The full XGBoost model obtained the maximum accuracy, a high negative predictive value, and the highest positive predictive value. Gender, age, unstable angina, atrial fibrillation and acute myocardial infarct are the variables that most influence EF value. Applied in the EHR dataset, with a total of 25,594 patients with an ICD-code of HF and no regular follow-up in cardiology clinics, 6170 (21.1%) were identified as pertaining to the reduced EF group.

CONCLUSION

The obtained algorithm was able to identify a number of HF patients with reduced ejection fraction, who could benefit from a protocol with a strong possibility of success. Furthermore, the methodology can be used for studies using data extracted from the Electronic Health Records.

Urinary- and Plasma-Derived Exosomes Reveal a Distinct MicroRNA Signature Associated With Albuminuria in Hypertension

Urinary albumin excretion (UAE) is a marker of cardiovascular risk and renal damage in hypertension. MicroRNAs (miRNAs) packaged into exosomes function as paracrine effectors in cell communication and the kidney is not exempt. This study aimed to state an exosomal miRNA profile/signature associated to hypertension with increased UAE and the impact of profibrotic TGF-β1 (transforming growth factor β1) on exosomes miRNA release. Therefore, exosomes samples from patients with hypertension with/without UAE were isolated and characterized. Three individual and unique small RNA libraries from each subject were prepared (total plasma, urinary, and plasma-derived exosomes) for next-generation sequencing profiling. Differentially expressed miRNAs were over-represented in Kyoto Encyclopedia of Genes and Genomes pathways, and selected miRNAs were validated by real-time quantitative polymerase chain reaction in a confirmation cohort. Thus, a signature of 29 dysregulated circulating miRNAs was identified in UAE hypertensive subjects, regulating 21 pathways. Moreover, changes in the levels of 4 exosomes-miRNAs were validated in a confirmation cohort and found associated with albuminuria. In particular miR-26a, major regulator of TGF-β signaling, was found downregulated in both type of exosomes when compared with healthy controls and to hypertension normoalbuminurics (P<0.01). Similarly, decreased miR-26a levels were found in podocyte-derived exosomes after TGF-β stress. Our results revealed an exosomes miRNA signature associated to albuminuria in hypertension. In particular, exosomes miR-26a seemed to play a key role in the regulation of TGF-β, a relevant effector in podocyte damage. These findings support the use of exosomes miRNAs as biomarkers of cardiovascular risk progression and therapeutic tools in early kidney damage.

Exosomes as Drug Delivery Systems: Endogenous Nanovehicles for Treatment of Systemic Lupus Erythematosus

Exosomes, nanometer-sized lipid-bilayer-enclosed extracellular vesicles (EVs), have attracted increasing attention due to their inherent ability to shuttle proteins, lipids and genes between cells and their natural affinity to target cells. Their intrinsic features such as stability, biocompatibility, low immunogenicity and ability to overcome biological barriers, have prompted interest in using exosomes as drug delivery vehicles, especially for gene therapy. Evidence indicates that exosomes play roles in both immune stimulation and tolerance, regulating immune signaling and inflammation. To date, exosome-based nanocarriers delivering small molecule drugs have been developed to treat many prevalent autoimmune diseases. This review highlights the key features of exosomes as drug delivery vehicles, such as therapeutic cargo, use of targeting peptide, loading method and administration route with a broad focus. In addition, we outline the current state of evidence in the field of exosome-based drug delivery systems in systemic lupus erythematosus (SLE), evaluating exosomes derived from various cell types and engineered exosomes.

Therapeutic Potential of Extracellular Vesicles in Hypertension-Associated Kidney Disease

Hypertension-mediated organ damage frequently includes renal function decline in which several mechanisms are involved. The present review outlines the state of the art on extracellular vesicles in hypertension and hypertension-related renal damage. Emerging evidence indicates that extracellular vesicles, small vesicles secreted by most cell types and body fluids, are involved in cell-to-cell communication and are key players mediating biological processes such as inflammation, endothelial dysfunction or fibrosis, mechanisms present the onset and progression of hypertension-associated kidney disease. We address the potential use of extracellular vesicles as markers of hypertension-mediated kidney damage severity and their application as therapeutic agents in hypertension-associated renal damage. The capacity of exosomes to deliver a wide variety of cargos to the target cell efficiently makes them a potential drug delivery system for treatment of renal diseases.

The Rab-Rabphilin system in injured human podocytes stressed by glucose overload and angiotensin II

Kidney injury in hypertension and diabetes entails, among in other structures, damage in a key cell of the glomerular filtration barrier, the podocyte. Podocytes are polarized and highly differentiated cells in which vesicular transport, partly driven by Rab GTPases, is a relevant process. The aim of the present study was to analyze Rab GTPases of the Rab-Rabphilin system in human immortalized podocytes and the impact of high glucose and angiotensin II. Furthermore, alterations of the system in urine cell pellets from patients with hypertension and diabetes were studied. Apoptosis was analyzed in podocytes, and mRNA level quantification, Western blot analysis, and immunofluorescence were developed to quantify podocyte-specific molecules and Rab-Rabphilin components (Rab3A, Rab27A, and Rabphilin3A). Quantitative RT-PCR was performed on urinary cell pellet from patients. The results showed that differentiated cells had reduced protein levels of the Rab-rabphillin system compared with undifferentiated cells. After glucose overload and angiotensin II treatment, apoptosis was increased and podocyte-specific proteins were reduced. Rab3A and Rab27A protein levels were increased under glucose overload, and Rabphilin3A decreased. Furthermore, this system exhibited higher levels under stress conditions in a manner of angiotensin II dose and time treatment. Immunofluorescence imaging indicated different expression patterns of podocyte markers and Rab27A under treatments. Finally, Rab3A and Rab27A were increased in patient urine pellets and showed a direct relationship with albuminuria. Collectively, these results suggest that the Rab-Rabphilin system could be involved in the alterations observed in injured podocytes and that a mechanism may be activated to reduce damage through the vesicular transport enhancement directed by this system.

Optimization of small RNA library preparation protocol from human urinary exosomes

Background

Sequencing of miRNAs isolated from exosomes has great potential to identify novel disease biomarkers, but exosomes have low amount of RNA, hindering adequate analysis and quantification. Here, we have assessed several steps in developing an optimized small RNA (sRNA) library preparation protocol for next-generation sequencing (NGS) miRNA analysis from urinary exosomes.

Methods

A total of 24 urinary exosome samples from donors were included in this study. RNA was extracted by column-based methods. The quality of extracted RNA was assessed by spectrophotometric quantification and Bioanalyzer software analysis. All libraries were prepared using the CleanTag small RNA library preparation protocol and the effect of our additional modifications on adapter-dimer presence, sequencing data and tagged small RNA library population was also analyzed.

Results

Our results show that good quality sequencing libraries can be prepared following our optimized small RNA library preparation protocol from urinary exosomes. When the size selection by gel purification step was included within the workflow, adapter-dimer was totally removed from cDNA libraries. Furthermore, the inclusion of this modification step within small RNA library protocol augmented the small RNA mapped reads, with an especially significant 37% increase in miRNA reads, and the gel purification step made no difference to the tagged miRNA population.

Conclusions

This study provides researchers with an optimized small RNA library preparation workflow for next generation sequencing based exosome-associated miRNA analysis that yields a high amount of miRNA mapped reads without skewing the tagged miRNA population significantly.

Urinary exosome miR-146a is a potential marker of albuminuria in essential hypertension

Background

There is increasing interest in using extracellular vesicle-derived microRNAs (miRNAs) as biomarkers in renal dysfunction and injury. Preliminary evidence indicates that miRNAs regulate the progression of glomerular disease. Indeed, exosomes from the renal system have provided novel evidence in the clinical setting of albuminuria. Thus, the aim of this study was to quantify the urinary miRNAs present in exosome and microvesicles (MVs), and to assess their association with the presence of increased urinary albumin excretion in essential hypertension.

Methods

Exosomes were collected from urine specimens from a cohort of hypertensive patients with (n = 24) or without albuminuria (n = 28), and from 20 healthy volunteers as a control group. Urinary exosomes were phenotyped by Western blot, tunable resistive pulse sensing, and electronic microscopy. Expression of miR-146a and miR-335* was analysed by qRT-PCR and any associations between albuminuria and exosomal miRNAs were analysed.

Results

Urinary miRNAs are highly enriched in exosome subpopulations compared to MVs, both in patients with or without increased albuminuria (p < 0.001), but not in the control group. High albuminuria was associated with 2.5-fold less miR-146a in exosomes (p = 0.017), whereas miR-146a levels in MV did not change. In addition, exosome miR-146a levels were inversely associated with albuminuria (r = 0.65, p < 0.0001), and discriminated the presence of urinary albumin excretion presence [area under the curve = 0.80, 95% confidence interval: 0.66–0.95; p = 0.0013].

Conclusions

Our results indicate that miRNAs were enriched in the urinary exosome subpopulation in hypertensive patients and that low miR-146a expression in exosomes was associated with the presence of albuminuria. Thus, urinary exosome miR-146a may be a potentially useful tool for studying early renal injury in hypertension.

Are IL18RAP gene polymorphisms associated with body mass regulation? A cross-sectional study

OBJECTIVES

To investigate the association between IL18RAP and body mass index (BMI) and obesity and to verify the effect of a polymorphism in the microRNA136 (MIR136) IL18RAP binding region.

DESIGN

We analysed samples from two Spanish cross-sectional studies, VALCAR (Spanish Mediterranean coast) and Hortega (Spanish centre). These studies aimed at analysing cardiovascular risk and development of cardiovascular disease in the general population. Both populations correspond to regions with different characteristics.

SETTING

Five IL18RAP single nucleotide polymorphisms were selected using the SYSNPs web tool and analysed by oligonucleotide ligation assay (SNPlex). For the MIR136 functional study, cells were transfected with plasmids containing different rs7559479 polymorphism alleles and analysed by luciferase reporter assays.

PARTICIPANTS

1970 individuals (Caucasian, both genders): VALCAR (468) and Hortega (1502).

RESULTS

rs2293225, rs2272127 and rs7559479 showed the following associations: rs7559479 G allele correlated with a higher obesity risk (P=0.01; OR=1.82; 95% CI 1.15 to 2.87 for the VALCAR group; P=0.033; OR=1.35; 95% CI 1.03 to 1.79 for the Hortega population) and higher body mass index (BMI) values (P=0.0045; P=0.1 for VALCAR and Hortega, respectively); a significant association with obesity (P=0.0024, OR=1.44, 95% CI 1.14 to 1.82) and increased BMI values (P=0.008) was found when considering both populations together. rs2293225 T allele was associated with lower obesity risk (P=0.036; OR=0.60; 95% CI 0.35 to 0.96) and lower BMI values (P=0.0038; OR=1.41) while the rs2272127 G allele was associated with lower obesity risk (P=0.028; OR=0.66; 95% CI 0.44 to 0.97) only in the VALCAR population. A reporter assay showed that the presence of the A allele in rs7559479 was associated with increased MIR136 binding to IL18RAP.

CONCLUSIONS

Our results suggest that polymorphisms in IL18RAP influence susceptibility to obesity. We demonstrated that the A allele in rs7559479 increases MIR136 binding, which regulates IL-18 system activity.

Extracellular Vesicles as Therapeutic Agents in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease that affects multiple organs. Currently, therapeutic molecules present adverse side effects and are only effective in some SLE patient subgroups. Extracellular vesicles (EV), including exosomes, microvesicles and apoptotic bodies, are released by most cell types, carry nucleic acids, proteins and lipids and play a crucial role in cell-to-cell communication. EVs can stimulate or suppress the immune responses depending on the context. In SLE, EVs can work as autoadjuvants, enhance immune complex formation and maintaining inflammation state. Over the last years, EVs derived from mesenchymal stem cells and antigen presenting cells have emerged as cell-free therapeutic agents to treat autoimmune and inflammatory diseases. In this review, we summarize the current therapeutic applications of extracellular vesicles to regulate immune responses and to ameliorate disease activity in SLE and other autoimmune disorders.

Urinary dedifferentiated podocytes as a non-invasive biomarker of lupus nephritis

BACKGROUND

Currently, renal biopsy remains the gold standard for the diagnosis and prognosis of lupus nephritis (LN). However, it is an invasive method, and new non-invasive laboratory tests are needed to identify renal involvement without renal biopsy. Podocyte damage plays an important role in the pathogenesis and progression of systemic lupus erythematosus (SLE). We characterize whether the phenotype of urinary podocytes (viability, apoptosis, mRNA and protein levels of the podocyte-associated molecules) is a novel marker of clinical and histological features in SLE patients with or without LN.

METHODS

We quantified in urinary sediments of 32 SLE patients and 20 controls, mRNA and protein levels of podocalyxin, synapotopodin, podocin, nephrin and WT-1 by quantitative real-time polymerase chain reaction and western blot analysis and correlated these with clinical and histological parameters. The viability of detached urine podocytes was analysed by flow cytometry with podocalyxin and annexin V/7-AAD double staining and immunofluorescence of urine podocyte cultures.

RESULTS

The degree of a poptotic podocytes from urine samples was significantly decreased in patients with LN, especially in the active state (33% compared with 75% in controls, P < 0.001), and the majority of the detached podocytes in the urine of patients with active LN were viable (70% grew in culture). Furthermore, urinary mRNA of podocyte-associated molecules was significantly lower in patients with active LN (P < 0.05) compared with healthy controls, and protein levels of podocyte markers were significantly increased in SLE patients, especially with LN compared with SLE without LN (P < 0.05) and the healthy control group (P < 0.01). Finally, urinary protein levels of podocyte-related markers were associated with proteinuria and histological features (P < 0.05 and P < 0.01), and receiver operating characteristics curves of protein levels discriminate between LN and healthy controls with an area under the curve (AUC) between 0.91 and 0.77 (P < 0.001).

CONCLUSIONS

Urinary dedifferentiated podocytes were shown in active LN, and their protein levels correlated with proteinuria and histological features in LN. These preliminary results suggest that it could be a potentially useful non-invasive marker for evaluating the progression of glomerular disease in SLE.

Increased Urinary Exosomal MicroRNAs in Patients with Systemic Lupus Erythematosus

There is increased interest in using microRNAs (miRNAs) as biomarkers in different diseases. Present in body fluids, it is controversial whether or not they are mainly enclosed in exosomes, thus we studied if urinary miRNAs are concentrated inside exosomes and if the presence of systemic lupus erythematosus with or without lupus nephritis modifies their distribution pattern. We quantified specific miRNAs in urine of patients with systemic lupus erythematosus (n = 38) and healthy controls (n = 12) by quantitative reverse-transcription PCR in cell-free urine, exosome-depleted supernatant and exosome pellet obtained by ultracentrifugation. In control group, miR-335* and miR-302d were consistently higher in exosomes than in exosome-depleted supernatant, and miR-200c and miR-146a were higher in cell-free fraction. In lupus patients, all urinary miRNAs tested were mainly in exosomes with lower levels outside them (p<0.05 and p<0.01, respectively). This pattern is especially relevant in patients with active lupus nephritis compared to the control group or to the SLE patients in absence of lupus nephritis, with miR-146a being the most augmented (100-fold change, p<0.001). Among the exosomal miRNAs tested, only the miR-146a discriminates the presence of active lupus nephritis. In conclusion, urinary miRNAs are contained primarily in exosomes in systemic lupus erythematosus, and the main increment was found in the presence of active lupus nephritis. These findings underscore the attractiveness of exosomal miRNAs in urine, a non-invasive method, as potential renal disease markers.

Enhanced reduction in oxidative stress and altered glutathione and thioredoxin system response to unsaturated fatty acid load in familial hypercholesterolemia

OBJECTIVES

Familial hypercholesterolemia (FH) is characterized by increased oxidative stress (OS) levels. In the postprandial state, lipids and lipoproteins modulate OS status through their impact on pro-oxidant and antioxidant mechanisms. The objective of this study was to evaluate in patients with FH the response to an unsaturated oral fat load test (OFLT) by analyzing the mRNA levels of genes involved in the glutathione and thioredoxin antioxidant systems.

DESIGN AND METHODS

We analyzed 14 FH patients and 20 normolipidemic and normoglycemic controls. In both groups, mRNA values of antioxidant enzyme genes (glutathione and thioredoxin systems) were determined at baseline and at 2, 4, 6, and 8h after OFLT by real time PCR.

RESULTS

In the fasting state the mRNA levels of antioxidant enzymes GPX4 and the GSR, GSS, and GCLC enzymes (involved in glutathione regeneration and synthesis) and thioredoxin (TXN), were significantly increased in the FH group compared to the healthy controls. Some genes (GPX1 and GPX4) were increased at 4h in both groups, but values for the rest of the antioxidant enzyme mRNAs were decreased in FH patients after 4h from unsaturated OFLT and were increased in controls.

CONCLUSIONS

We concluded that an OFLT with predominantly unsaturated fat has a different effect on postprandial antioxidant enzyme mRNA levels in controls than in FH patients. Increased antioxidant enzyme mRNA is not the main way to reduce postprandial oxidative stress in FH. This difference could determine the influence of dietary patterns in these patients.

Gill histopathological and oxidative stress evaluation in native fish captured in Portuguese northwestern rivers

The Northwestern Portuguese region is densely populated and highly industrialized, suffering from high anthropogenic pressure. To assess the biological effect of the several pollutants that are constantly released to the water, a biomarker-based biomonitoring is a promising approach that may provide early-warning signals of pollutants exposure. Fish gill is the first target of pollutants action, thus histopathological and biochemical changes may constitute potential biomarkers. To evaluate this hypothesis, three native fish species (barbel-Luciobarbus bocagei, chub-Squalius carolitertii and nase-Pseudochondrostoma sp.) were sampled in Northwestern Portuguese rivers, the gill histopathological changes were qualitative and quantitatively analyzed and the lipid peroxidation and glutathione-S-transferase activity were determined. A multivariate statistical analysis was performed to establish correlations between these biological responses, environmental variables and ecological status. The quantitative evaluation of the main histopathological changes and oxidative stress responses emphasize the differences, among species, in the responses to the presence of contaminants in water. Discriminant canonical analysis showed that filament epithelium proliferation, necrosis and GST activity were the main contributors to discriminate the ecological status classification. In addition, the results showed that a wide range of environmental factors are influencing fish physiology. In conclusion, the gill biological responses, although not reflecting specific contaminants, can be used as biomarkers of ecosystems perturbation.

Interface formation in monolayer graphene-boron nitride heterostructures

The ability to control the formation of interfaces between different materials has become one of the foundations of modern materials science. With the advent of two-dimensional (2D) crystals, low-dimensional equivalents of conventional interfaces can be envisioned: line boundaries separating different materials integrated in a single 2D sheet. Graphene and hexagonal boron nitride offer an attractive system from which to build such 2D heterostructures. They are isostructural, nearly lattice-matched, and isoelectronic, yet their different band structures promise interesting functional properties arising from their integration. Here, we use a combination of in situ microscopy techniques to study the growth and interface formation of monolayer graphene-boron nitride heterostructures on ruthenium. In a sequential chemical vapor deposition process, boron nitride grows preferentially at the edges of existing monolayer graphene domains, which can be exploited for synthesizing continuous 2D membranes of graphene embedded in boron nitride. High-temperature growth leads to intermixing near the interface, similar to interfacial alloying in conventional heterostructures. Using real-time microscopy, we identify processes that eliminate this intermixing and thus pave the way to graphene-boron nitride heterostructures with atomically sharp interfaces.

Reduced mortality for women with mammography-detected breast cancer in east Denmark and south Sweden

The 5-year relative survival from breast cancer in Denmark is 10 percentage points lower than in Sweden. This difference has been demonstrated previously as being caused partly by more involved lymph nodes and larger tumours in Denmark. Sweden has had nationwide mammography-screening coverage since 1991, whereas this is still in its infancy in Denmark. In the search for an explanation for the remaining survival difference, patient delay was a likely candidate. This study compared patient delay and mammography-detection between two national regions. Data on patient delay and mammography were obtained from hospital records from 1989 and 1994, and analysed using Cox proportional hazard analysis of death within the first 5 years, with the factors age, country, delay/mammography detection and established patho-anatomic variables. A comparison of patient delay and mammography detection in 1989 and 1994 showed more mammography-detected tumours in south Sweden and more women with long delay in east Denmark. Mammography detection, but not long patient delay, had a significant effect on the death hazard when adjusting for patho-anatomic risk factors. The hazard ratio was not eliminated in 1989, but in 1994, the hazard ratio between east Denmark and south Sweden was reduced from 1.3 to 1.1. In conclusion, patient delay did not appear to have any effect on 5-year survival when adjusting for patho-anatomic factors, but tumour detection by mammography affected survival favourably and partly explained the survival difference between east Denmark and south Sweden.

Structural properties of Y1-xYbxNi2B2C synthesized at high pressure: EXAFS data analysis

Local structure of Y(1-x)Yb(x)Ni2B2C series synthesized at high pressure 8 GPa has been studied using EXAFS. Measurements were performed at the Ni K-edge in temperature range 5-300 K. The results show that the Debye-Waller factor for Ni-Ni bond in the parent YNi2B2C compound is characterized by the Einstein temperature O(E) = 350 K, while a minimum value O(E) = 300 K is reached for the compound with = 0.025, which has the highest critical temperature T(c) = 12.5K of the superconductive transition. This correlates with the further suppressing of superconductivity and with the appearance of the local magnetic moments in the investigated Y(1-x)Yb(x)Ni2B2C series for x > or = 0.05 compounds. Observed changes in the local electronic and the local crystal structure of this system as a function of Yb concentration and of temperature were explained in the frame of the band filling effect.

Lattice softening in superconducting compositions of Ba(K)BiO3

Temperature dependent x-ray absorption spectra investigation were measured for Ba(1-x)K(x)BiO3 (Bi L3-edge) with x =0.0, 0.25, 0.4, 0.5 and for BaPbO3 (Pb L3-edge). It was found that at low temperatures the Debye-Waller factor of the square diagonal Bi-Bi bond has the maximum value near the insulator-metal phase transition for the compound with x = 0.25 and x = 0.4. Temperature dependence of the Debye-Waller factor of Bi-Bi bond strongly differs from the Einstein model curve that well describes the harmonic systems (for example BaPbO3). This behavior is consistent with the strong anharmonicity of the Bi-O shell due to the double-well vibration potential reported by us earlier. Presented results point to the essential lattice softening of the superconducting compositions, which is important for the understanding of superconductivity mechanism in perovskite type oxides.

Malignant nodular hidradenoma

A 54-year-old male farmer was seen in May 1990 with a violaceous, exulcerated tumor, 2x1.5 cm in diameter, localized to the sternal area of the chest. The tumor had been present for 30 years, showing slow progressive growth; it was excised, but recurred 2 years before our initial evaluation. The tumor was again excised with a wide free margin. The histopathologic study showed an ill-defined, epithelial neoformation, formed by lobules of clear polygonal cells at the deep dermis and subcutaneous tissue; there was a second group of smaller cells with a basaloid aspect, a few of them presenting slight atypia. The tumoral lobules were surrounded by a myxoid material with vascular proliferation. The epidermis was normal. The histopathologic report was of a malignant nodular hidradenoma. No evidence of lymph node or distant metastases was found. One year after the excision, the tumor recurred at the surgical site, and an axillary lymph node showed metastatic cells. The lesion was excised for a third time and the patient was lost to follow-up.

Distribution of [3H]diadenosine tetraphosphate binding sites in rat brain

The distribution of the diadenosine tetraphosphate high-affinity binding sites has been studied in rat brain by an autoradiographic method using [3H]diadenosine tetraphosphate as the ligand. The binding characteristics are comparable to those described in studies performed on rat brain synaptosomes. White matter is devoid of specific binding. The range of binding site densities in gray matter varies from 3 to 15 fmol/mg of tissue, exhibiting a widespread but heterogeneous distribution. The highest densities correspond to the seventh cranial nerve, medial superior olive, pontine nuclei, glomerular and external plexiform layers of the olfactory bulb, and the granule cell layer of the cerebellar cortex. Intermediate density levels of binding correspond to different cortical areas, several nuclei of the amygdala, and the oriens and pyramidal layers of the hippocampal formation. The localization of diadenosine tetraphosphate binding sites in the brain may provide information on the places where diadenosine polyphosphate compounds can be expected to function in the central nervous system.

Prevalence of mental disorder in military children and adolescents: findings from a two-stage community survey

OBJECTIVE

Because previous reports have suggested that children of military families are at greater risk for psychopathology, this study examines the levels of psychopathology in an epidemiological community sample of military children all living on a military post.

METHOD

Standardized psychopathology rating scales and a structured diagnostic interview (the Diagnostic Interview Schedule for Children [DISC], version 2.1) were used in a multimethod, multistage survey; 294 six- to seventeen-year-old military children and their parents participated in the study.

RESULTS

Parent- and child-administered structured DSM-III-R DISC interviews indicated that children's levels of psychopathology were at levels consistent with studies of other normal samples. In addition, parents' and children's symptom checklist ratings of children were at national norms, as were parents' ratings of their own symptoms.

CONCLUSIONS

Overall results do not support the notion that levels of psychopathology are greatly increased in military children. Further studies of military families should address the effects of rank and socioeconomic status, housing, and the current impact of life stressors on the parents as well as the children, in order to avoid drawing erroneous conclusions about parts or all of the military community.

Comparison of derivatization procedures for the determination of diuretics in urine by gas chromatography-mass spectrometry

Three different GC-MS screening procedures, which use different ways of derivatization (methylation), are compared. In the first one, derivatization with iodomethane in acetone and a previous solid-liquid extraction is used; the second one is based on an extractive alkylation method using iodomethane in toluene (liquid-liquid extraction); and the last one is flash methylation by pyrolysis of tetraalkylammonium salts in the injector of the gas chromatograph using trimethylanilinium as the derivatization agent. The speed of the extraction, reproducibility and accuracy have been compared for 20 diuretics including the ones most often used in sports, such as bumetanide, ethacrynic acid, acetazolamide, dichlorphenamide, furosemide, hydroflumethiazide, hydrochlorothiazide and chlorthalidone; they have also been applied to the two uricosuric agents probenecid and benzbromarone.

Psychometric analysis in children with mental retardation due to perinatal hypoxia treated with fibroblast growth factor (FGF) and showing improvement in mental development

Basic fibroblast growth factor (bFGF) has shown a neurotrophic effect in the neurons of several CNS areas. In vivo, it contributes to restore neurochemical and morphological deficits in different rodent models of brain damage, including rats with brain damage induced by hypoxia/ischemia when FGF was intramuscularly (i.m.) administered. Toxicological and immunological studies performed in rats, mice and volunteers showed no evidence of side-effects. Bovine FGF was i.m. administered in children with mental retardation caused by perinatal hypoxia, aged 1-15 years, at dosages of 0.4 or 0.28 microgram kg-1, once or twice a month, over 7-12 months. Group A [n = 12; 6 treated (T), 6 controls (Ct)], group B (n = 16; 8 T, 8 Ct) and group C (n = 67; 45 T, 22 Ct) were evaluated with the P. A. R. scale, the WISC-RM and the Gesell scale, respectively. Development increased significantly in treated children from groups A (P < 0.02) and C (P < 0.001), and IQ rose by more than 10 points (P < 0.001) in group B patients.