MicroRNA-124 Regulates STAT3 Expression and Is Down-regulated in Colon Tissues of Pediatric Patients With Ulcerative Colitis

Background & Aims - Altered levels and functions of microRNAs (miRs) have been associated with inflammatory bowel diseases (IBDs), although little is known about their roles in pediatric IBD. We investigated whether colonic mucosal miRs are altered in children with ulcerative colitis (UC). Methods - We used a library of 316 miRs to identify those that regulate phosphorylation of STAT3 in NCM460 human colonocytes incubated with interleukin-6. Levels of miR-124 were measured by real-time PCR analysis of colon biopsies from pediatric and adult patients with UC and patients without IBD (controls), and of HCT-116 colonocytes incubated with 5-aza-2’-deoxycytidine. Methylation of the MIR124 promoter was measured by quantitative methylation-specific PCR. Results - Levels of phosphorylated STAT3 and the genes it regulates (encoding VEGF, BCL2, BCLXL, and MMP9) were increased in pediatric patients with UC, compared to control tissues. Overexpression of miR-124, let-7, miR-125, miR-26, or miR-101 reduced STAT3 phosphorylation by ≥75% in NCM460 cells; miR-124 had the greatest effect. miR-124 was downregulated specifically in colon tissues from pediatric patients with UC and directly targeted STAT3 mRNA. Levels of miR-124 were decreased whereas levels of STAT3 phosphorylation increased in colon tissues from pediatric patients with active UC, compared to those with inactive disease. Furthermore, levels of miR-124 and STAT3 were inversely correlated in mice with experimental colitis. Downregulation of miR-124 in tissues from children with UC was attributed to hypermethylation of its promoter region. Incubation of HCT-116 colonocytes with 5-aza-2’ deoxycytidine upregulated miR-124 and reduced levels of STAT3 mRNA. Conclusions - MiR-124 appears to regulate the expression of STAT3. Reduced levels of miR-124 in colon tissues of children with active UC appear to increase expression and activity of STAT3, which could promote inflammation and pathogenesis of UC in children

Thermographic measurement of canopy temperature is a useful tool for predicting water deficit effects on fruit weight in citrus trees

[EN] Alternative and more practical methods for plant water stress detection than stem water potential (ψs) and stomatal conductance (gs) are needed when regulated deficit irrigation (RDI) strategies are applied. The aim of this experiment was to compare sap flow and canopy temperature (Tc) measurements with more classical methods like ψs or gs to predict the effect of deficit irrigation on fresh fruit weight in citrus trees. The experiment was performed during the summer of 2011 in a “Clementina de Nules” orchard undergoing RDI. Sap flow was determined by means of the compensation heat pulse method in well-watered and RDI trees. Tc was measured continuously with infrared thermometers (IRTs) mounted over the canopies and also weekly with an infrared hand-operated thermographic camera taking frontal images of the sunlit side of tree crowns. Concurrently, ψs and gs were also measured on all trees. Results showed that the evolution of the relative transpiration obtained with the sap flow sensors was in agreement with the plant water stress experienced. The values of Tc obtained with the fixed IRTs, normalized by air temperature (Tc − Ta) were in general poorly related with ψs and gs. However, when Tc was obtained from thermal imaging, there was a good correlation with ψs in days of relatively high water stress (i.e. when ψs differences among treatments were >1.0 MPa). The average fruit weight at harvest was significantly correlated with all the stress indicators, and the best correlation was that of thermographic Tc followed by ψs and gs. Overall, results showed that in citrus trees Tc measurement obtained from thermal imaging is a good tool to predict the effect of water deficit on fresh fruit weight.The authors thank H. Hernandez and T. Yeves for their help with the field work. This experiment has been funded by the RIDECO-CONSOLIDER CSD2006-00067 and Telerieg Interreg IV Sudoe projects. C. Ballester was holder of a predoctoral fellowship FPI-INIA-CCAA. D.S. Intrigliolo acknowledges the financial support received from the Spanish Ministry of Economy and Competitiveness (MINECO) program "Ramon y Cajal".Ballester, C.; Castel, J.; Jiménez Bello, MÁ.; Castel Sánchez, JR.; Intrigliolo Molina, DS. (2013). Thermographic measurement of canopy temperature is a useful tool for predicting water deficit effects on fruit weight in citrus trees. Agricultural Water Management. 122:1-6. https://doi.org/10.1016/j.agwat.2013.02.005S1612

Direct observations of CO2 emission reductions due to COVID-19 lockdown across European urban districts

The measures taken to contain the spread of COVID-19 in 2020 included restrictions of people's mobility and reductions in economic activities. These drastic changes in daily life, enforced through national lockdowns, led to abrupt reductions of anthropogenic CO(2 )emissions in urbanized areas all over the world. To examine the effect of social restrictions on local emissions of CO2, we analysed district level CO(2 )fluxes measured by the eddy-covariance technique from 13 stations in 11 European cities. The data span several years before the pandemic until October 2020 (six months after the pandemic began in Europe). All sites showed a reduction in CO2 emissions during the national lockdowns. The magnitude of these reductions varies in time and space, from city to city as well as between different areas of the same city. We found that, during the first lockdowns, urban CO2 emissions were cut with respect to the same period in previous years by 5% to 87% across the analysed districts, mainly as a result of limitations on mobility. However, as the restrictions were lifted in the following months, emissions quickly rebounded to their pre-COVID levels in the majority of sites.Peer reviewe

Gene Network Analysis of Bone Marrow Mononuclear Cells Reveals Activation of Multiple Kinase Pathways in Human Systemic Lupus Erythematosus

Background: Gene profiling studies provide important information for key molecules relevant to a disease but are less informative of protein-protein interactions, post-translational modifications and regulation by targeted subcellular localization. Integration of genomic data and construction of functional gene networks may provide additional insights into complex diseases such as systemic lupus erythematosus (SLE). Methodology/Principal Findings: We analyzed gene expression microarray data of bone marrow mononuclear cells (BMMCs) from 20 SLE patients (11 with active disease) and 10 controls. Gene networks were constructed using the bioinformatic tool Ingenuity Gene Network Analysis. In SLE patients, comparative analysis of BMMCs genes revealed a network with 19 central nodes as major gene regulators including ERK, JNK, and p38 MAP kinases, insulin, Ca2+ and STAT3. Comparison between active versus inactive SLE identified 30 central nodes associated with immune response, protein synthesis, and post-transcriptional modification. A high degree of identity between networks in active SLE and non-Hodgkin's lymphoma (NHL) patients was found, with overlapping central nodes including kinases (MAPK, ERK, JNK, PKC), transcription factors (NF-kappaB, STAT3), and insulin. In validation studies, western blot analysis in splenic B cells from 5-month-old NZB/NZW F1 lupus mice showed activation of STAT3, ITGB2, HSPB1, ERK, JNK, p38, and p32 kinases, and downregulation of FOXO3 and VDR compared to normal C57Bl/6 mice. Conclusions/Significance: Gene network analysis of lupus BMMCs identified central gene regulators implicated in disease pathogenesis which could represent targets of novel therapies in human SLE. The high similarity between active SLE and NHL networks provides a molecular basis for the reported association of the former with lymphoid malignancies

What is the future of targeted therapy in rheumatology: biologics or small molecules?

Background: Until late in the 20th century, the therapy of rheumatic diseases relied on the use of drugs that had been developed through empirical approaches without detailed understanding of the molecular mechanisms involved. That approach changed with the introduction of biologic therapeutics at the end of the 20th century and by the recent development of small-molecule inhibitors of intracellular signal transduction pathways. Here we compare and discuss the advantages and disadvantages of those two groups of targeted anti-inflammatory therapeutics.Discussion: TNF-blocking biologic agents were introduced into the therapy of rheumatoid arthritis and other autoimmune and inflammatory diseases in the late 1990s. Further biologic agents targeting cytokine networks or specific lymphocyte subsets have since been added to the armamentarium of anti-rheumatic therapy. During the last few years, another wave of novel discoveries led to the development of a new class of small molecule anti-inflammatory compounds targeting intracellular signal transduction molecules, such as tyrosine kinases. In all those cases, the specific targets of the drugs are well defined and significant knowledge about their role in the disease pathomechanism is available, qualifying them for being targeted therapeutics for inflammatory rheumatic diseases. While both groups of targeted therapeutics offer significant clinical benefit, they clearly differ in several aspects, such as the localization of their targets, their route of administration and target specificity, as well as technical details such as manufacturing procedures and cost basis. In this debate paper, we compare the advantages and disadvantages of the two different approaches, aiming to shed light on the possible future of targeted therapies.Summary: Biologic therapeutics and small-molecule inhibitors both have significant advantages and disadvantages in the therapy of rheumatic diseases. The future of targeted therapies is one of the most exciting questions of current rheumatology research and therapy. © 2014 Mócsai et al.; licensee BioMed Central Ltd

Impact of Systemic Inflammation and Autoimmune Diseases on apoA-I and HDL Plasma Levels and Functions

The cholesterol of high-density lipoproteins (HDLs) and its major proteic component, apoA-I, have been widely investigated as potential predictors of acute cardiovascular (CV) events. In particular, HDL cholesterol levels were shown to be inversely and independently associated with the risk of acute CV diseases in different patient populations, including autoimmune and chronic inflammatory disorders. Some relevant and direct anti-inflammatory activities of HDL have been also recently identified targeting both immune and vascular cell subsets. These studies recently highlighted the improvement of HDL function (instead of circulating levels) as a promising treatment strategy to reduce inflammation and associated CV risk in several diseases, such as systemic lupus erythematosus and rheumatoid arthritis. In these diseases, anti-inflammatory treatments targeting HDL function might improve both disease activity and CV risk. In this narrative review, we will focus on the pathophysiological relevance of HDL and apoA-I levels/functions in different acute and chronic inflammatory pathophysiological conditions

Διερεύνηση του ρόλου των microRNAs στην ρύθμιση της έκφρασης γονιδίων που υπεισέρχονται στην παθογένεια του συστηματικού ερυθηματώδους λύκου (ΣΕΛ) σε πειραματικά πρότυπα και ασθενείς με ΣΕΛ

Systemic lupus erythematosus (SLE) is the prototypic autoimmune disease that involves multiple genetic and environmental contributions. Although its etiology is not established, it is considered that the immune system of SLE patients is predisposed to aberrant responsiveness. The hallmark of the disease is the production of anti-nuclear autoantibodies and the formation of immunocomplexes that promote injury to various target organs. Defects in T cell antigen receptor–mediated signaling have been shown to lead to breakdown of immunological tolerance. Aberrant co-stimulation and skewed cytokine production by CD4+ T lymphocytes are important mechanisms that lead to B cell hyper-responsiveness in SLE.Considering the complexity of the disease, high throughput techniques have been used to dissect disease mechanisms and identify novel molecules involved in the deregulation of the immune response in human SLE. cDNA microarrays have been used in SLE and have found unique gene signatures in the disease. Although these studies have provided important insights into genetic pathways involved in lupus pathogenesis, they offer only limited information with regard to regulatory mechanisms that control gene expression.Micro-RNAs (miRNAs) are potent negative modulators of genes involved in a variety of cellular processes. In animal cells, miRNAs regulate their targets by translational inhibition and mRNA destabilization. Deregulation of miRNA expression has been implicated in the pathogenesis of several human diseases and they are considered as potential biomarkers and therapeutic targets. Compared with other gene regulatory mechanisms such as epigenetic and transcription factors, miRNA-mediated effects occur prior to protein synthesis, thus allowing for the fine tuning of gene expression. This is particularly important for the immune system that has to adjust rapidly in response to environmental changes.MiRNAs have the potential to regulate the development and function of both the innate and the adaptive immune system and several miRNAs have been shown to be activated after stimulation of various immune pathways. Deregulation of miRNAs leads to uncontrolled immune response and development of autoimmunity in mice. Altered miRNA expression has also been reported in human autoimmune diseases, such as SLE, rheumatoid arthritis and multiple sclerosis but the mechanisms by which these changes promote autoimmunity have not been thoroughly investigated.In this study, we investigated the role of this new class of gene modulators in human SLE. To this end, we analyzed the miRNA profile in peripheral blood mononuclear cells (PBMCs) of SLE patients by microarray technology aiming to identify novel genes involved in disease pathogenesis. We found a set of differentially expressed miRNAs in SLE patients compared to healthy individuals and in patients with active versus inactive disease. Several miRNAs displayed a strong correlation with disease activity. Longitudinal studies in large patient cohorts are needed to define the use of miRNAs as disease biomarkers. Importantly, the identified miRNAs are predicted to regulate genes and processes pertinent to the pathogenesis of SLE.Among these genes, mir-21 was one of the highest up-regulated in SLE patients and displayed the strongest correlation with disease activity (r2= 0,92). Compared with controls, CD4 T lymphocytes from patients with SLE had higher basal and activation-induced miR-21 expression. Silencing of miR-21 reversed the activated phenotype of T cells from patients with SLE—namely, enhanced proliferation, IL10 production, CD40L expression and their capacity to drive B cell maturation into Ig-secreting CD19+CD38 hi IgD−plasma cells. Overexpression of miR-21 in normal T cells led to acquisition of an activated phenotype. Investigation of putative gene- targets showed that PDCD4 (a selective protein translation inhibitor) was suppressed by miR-21 and its expression was decreased in active SLE. Together these data suggest that miRNAs may regulate major pathogenic pathways in SLE.Ο Συστηματικός Ερυθηματώδης Λύκος (ΣΕΛ) αποτελεί ένα συστηματικό νόσημα, αυτοάνοσης αιτιολογίας, που περιλαμβάνει πολλαπλές γενετικές και περιβαλλοντικές παραμέτρους. Οι ασθενείς ποικίλουν όσο αναφορά τα κλινικά συμπτώματα, την πρόγνωση και την ανταπόκριση στην θεραπεία. Το κύριο χαρακτηριστικό του νοσήματος είναι η υπερδραστηκότητα των Β λεμφοκυττάρων του ανοσοποιητικού συστήματος και η αυξημένη παραγωγή αυτοαντισωμάτων. Μηχανισμοί που εξαρτώνται αλλά και που είναι ανεξάρτητοι από τα Τ λεμφοκύτταρα θεωρούνται υπεύθυνοι για την υπερδραστηκότητα των Β λεμφοκυττάρων που παρατηρείται στην νόσο. Ο φαινότυπος της νόσου είναι αποτέλεσμα ενός ευρέως φάσματος αλλαγών στην έκφραση γονιδίων που συμβαίνουν όχι μόνο στους προσβεβλημένους ιστούς αλλά και στα δραστικά κύτταρα του ανοσοποιητικού συστήματος. Λαμβάνοντας υπόψη την πολυπλοκότητα της νόσου, τεχνικές που επιτρέπουν την ταυτόχρονη μελέτη ενός μεγάλου αριθμού παραμέτρων (high throughput techniques) είναι απαραίτητες για την αποσαφήνιση και κατανόηση της αιτιολογίας της νόσου. Η τεχνολογία των μικροσυστοιχείων (microarrays) έχει συμβάλει ουσιαστικά στην ταυτοποίηση μορίων, κυτταρικών πληθυσμών αλλα και σηματοδοτικών μονοπατιών που εμπλέκονται στην παθοφυσιολογία της νόσου. Παρόλα αυτά, κρίνεται απαραίτητη η ταυτοποίηση νέων μορίων στόχων με δυνατότητες χρήσης για προγνωστικούς, διαγνωστικούς και θεραπευτικούς σκοπούς στην αντιμετώπιση του ΣΕΛ.Τα microRNAs (miRNAs) αποτελούν μια νέα ομάδα εξελικτικά καλά διατηρημένων μικρών μορίων RΝΑ που δεν κωδικοποιούν για πρωτεΐνες και θεωρούνται σημαντικοί αρνητικοί ρυθμιστές της έκφρασης γονιδίων. Ανάλογα με τον βαθμό συμπληρωματικότητας, τα miRNAs προσδένονται στα mRNAs - στόχους τους και είτε προκαλούν την αποικοδόμηση τους είτε αναστέλλουν την μετάφραση τους σε πρωτεϊνικά μόρια. Σε σύγκριση με άλλες κατηγορίες ρυθμιστών γονιδίων, όπως μεταγραφικούς και επιγενετικούς παράγοντες, τα miRNAs βρίσκονται ένα βήμα ακριβώς πριν την πρωτεϊνική σύνθεση, καθιστώντας τα ,ίσως, πιο κατάλληλα μόρια για την ρύθμιση της γονιδιακής έκφρασης ως αποτέλεσμα ανταπόκρισης του κυττάρου σε εξωτερικά ερεθίσματα και προσαρμογή του στο εξωκυττάριο περιβάλλον. Τα miRNAs εμπλέκονται σε ζωτικής σημασίας διαδικασίες όπως τον πολλαπλασιασμό, την διαφοροποίηση και την απόπτωση των κυττάρων και έχουν ήδη συσχετιστεί με πολλές ανθρώπινες ασθένειες. Εξαιτίας της έντονης επιρροής των φλεγμονωδών ερεθισμάτων στην έκφραση γονιδίων, η ανοσιακή απόκριση έχει την δυνατότητα ρύθμισης των επιπέδων έκφρασης διαφόρων miRNAs. Αντίθετα, αρκετά miRNAs έχουν δειχτεί ότι εμπλέκονται στην ρύθμιση του συστήματος της φυσικής και της ειδικής ανοσίας. Μεταβολές στην έκφραση miRNAs έχουν περιγραφεί σε αυτοάνοσα νοσήματα, όπως ο Συστηματικός Ερυθηματώδης Λύκος (ΣΕΛ), η ρευματοειδής αρθρίτιδα (ΡΑ) και η πολλαπλή σκλήρυνση, αλλά οι μηχανισμοί που διαταράσονται και προάγουν την αυτοανοσία δεν έχουν χαρακτηριστεί. Στην παρούσα μελέτη, θελήσαμε να μελετήσουμε τον ρόλο της νέας αυτής τάξης γονιδίων στην ρύθμιση και διαταραχή της ανοσολογικής απόκρισης στον ΣΕΛ, που θα μπορούσε με την σειρά του να βοηθήσει στην αποσαφήνιση και κατανόηση των παθογενετικών μηχανισμών που εμπλέκονται στη νόσο. Με την χρήση της τεχνολογίας των μικροσυστοιχείων ταυτοποιήσαμε έναν αριθμό miRNAs με διαφορετική έκφραση στα μονοκύτταρα περιφερικού αίματος ασθενών με ΣΕΛ. Αξίζει να σημειωθεί, ότι, ορισμένα miRNAs είχαν πολύ καλή συσχέτιση με την ενεργότητα της ασθένειας, υποδεικνύοντας ότι μπορούν να χρησιμοποιηθούν ως προγνωστικοί παράγοντες. Επιπλέον, αρκετά miRNAs προβλέπονται να στοχεύουν γονίδια που εμπλέκονται σε διαδικασίες που είναι διαταραγμένες στον ΣΕΛ. Το mir-21 ήταν απο τα γονίδια που παρουσίαζε αυξημένη έκφραση στα μονοκύτταρα ασθενών με ΣΕΛ, σε σχέση με τους υγιείς μάρτυρες και είχε πολύ καλή συσχέτιση με την ενεργότητα της νόσου (r2= 0,92). Επίσης, η έκφραση του mir-21 βρέθηκε αυξημένη και στα Β αλλά και στα CD4 T λεμφοκύτταρα ασθενών με ΣΕΛ. Σίγηση του miR-21 επηρρέασε σημαντικά χαρακτηριστικά των Τ λεμφοκυττάρων που συμβάλουν στην υπερδραστικότητα τους στον ΣΕΛ, όπως τον πολλαπλασιασμό, την παραγωγή κυτταροκινών (IL10) και την έκφραση μορίων συνδιέγερσης επιφανείας (CD40L). Επιπλέον, η αναστολή της έκφρασης του mir-21 στα CD4 Τ λεμφοκύτταρα μείωσε την ικανότητα τους να προάγουν την διαφοροποίηση των B λεμφοκυττάρων σε Ig-παραγωγά CD19+CD38hiIgD − πλασματοκύτταρα. Αντίθετα, η υπερέκφραση του miR-21 σε υγιή T λεμφοκύτταρα οδήγησε στην ανάκτηση ενός ενεργοποιημένου ‘ΣΕΛ’ φαινοτύπου. Στην συνέχεια, αναζητήσαμε γονίδια-στόχους του miR-21 και βρήκαμε οτι αναστέλει την έκφραση της πρωτεΐνης PDCD4, η οποία βρέθηκε με μειωμένη έκφραση στους ασθενείς με ΣΕΛ. Συνολικά, τα παραπάνω δεδομένα τονίζουν τον ρόλο των miRNAs στην ρύθμιση σημαντικών μοριακών μονοπατιών που συμβάλουν στην παθογένεια της νόσου