Multiple sclerosis is an autoimmune disease, with higher prevalence in women, in whom the immune system is dysregulated. This dysregulation has been shown to correlate with changes in transcriptome ...expression as well as in gene-expression regulators, such as non-coding RNAs (e.g. microRNAs). Indeed, some of these have been suggested as biomarkers for multiple sclerosis even though few biomarkers have reached the clinical practice. Recently, a novel family of non-coding RNAs, circular RNAs, has emerged as a new player in the complex network of gene-expression regulation. MicroRNA regulation function through a 'sponge system' and a RNA splicing regulation function have been proposed for the circular RNAs. This regulating role together with their high stability in biofluids makes them seemingly good candidates as biomarkers. Given the dysregulation of both protein-coding and non-coding transcriptome that have been reported in multiple sclerosis patients, we hypothesised that circular RNA expression may also be altered. Therefore, we carried out expression profiling of 13.617 circular RNAs in peripheral blood leucocytes from multiple sclerosis patients and healthy controls finding 406 differentially expressed (P-value < 0.05, Fold change > 1.5) and demonstrate after validation that, circ_0005402 and circ_0035560 are underexpressed in multiple sclerosis patients and could be used as biomarkers of the disease.
The aim of this study was to identify differentially expressed microRNAs (miRNAs) that might play an important role in the etiology of retinal degeneration in a genetic mouse model of retinitis ...pigmentosa (rd10 mice) at initial stages of the disease.
miRNAs-mRNA interaction networks were generated for analysis of biological pathways involved in retinal degeneration.
Of more than 1900 miRNAs analyzed, we selected 19 miRNAs on the basis of (1) a significant differential expression in rd10 retinas compared with control samples and (2) an inverse expression relationship with predicted mRNA targets involved in biological pathways relevant to retinal biology and/or degeneration. Seven of the selected miRNAs have been associated with retinal dystrophies, whereas, to our knowledge, nine have not been previously linked to any disease.
This study contributes to our understanding of the etiology and progression of retinal degeneration.
Abstract We demonstrate a straightforward method to encapsulate siRNA into naturally available and unmodified human apoferritin. The encapsulation into apoferritin is independent of the sequence of ...the siRNA and provides superior protection for those sensitive molecules. High efficiency in transfection can be achieved in human tumorigenic cells, human primary mesenchymal stem cells (hMSC) and peripheral blood mononuclear cells (PBMCs). In contrast to Lipofectamine, highly effective gene silencing can be achieved with ferritin as the delivery agent in both tumor cells and PBMCs at low siRNA concentrations (10 nM). As an endogenous delivery agent, apoferritin does not induce immune activation of T- and B-cells in human PBMCs. Apoferritin shows intrinsic anti-inflammatory effects and apoferritin-mediated delivery shows a preference for immune-activated T- and B-cells, a natural selectivity which may turn useful for drug delivery in case of infections or inflammatory diseases.
The hippocampus is a brain area linked to cognition. The mechanisms that maintain cognitive activity in humans are poorly understood. Centenarians display extreme longevity which is generally ...accompanied by better quality of life, lower cognitive impairment, and reduced incidence of pathologies including neurodegenerative diseases. We performed transcriptomic studies in hippocampus samples from individuals of different ages (centenarians ≥97 years, old, and young) and identified a differential gene expression pattern in centenarians compared to the other two groups. In particular, several isoforms of metallothioneins (MTs) were highly expressed in centenarians. Moreover, we identified that MTs were mainly expressed in astrocytes. Functional studies in human primary astrocytes revealed that MT1 and MT3 are necessary for their homeostasis maintenance. Overall, these results indicate that the expression of MTs specifically in astrocytes is a mechanism for protection during aging.
Chronic social stress can increase susceptibility to chronic diseases such as depression. One of the most used models to study the physiological mechanisms and behavioral outcomes of this type of ...stress is chronic defeat stress (CDS) in male mice. OF1 male mice were subjected to a stress period lasting 18 days. During that time, non-stressed animals were housed in groups. The cluster analysis of the behavioral profile displayed during the first social interaction divided subjects into two groups: active/aggressive (AA) and passive/reactive (PR). The day after the end of the stress period, the following behavioral analyses were performed: the sucrose preference test (SPT) on day 19, the open field test (OFT) on day 20, and the forced swim test (FST) on day 21. Immediately after completing the last test, animals were weighed, and blood samples were obtained. Then, they were sacrificed, and their prefrontal cortices and hippocampi were removed and stored to analyze monoamine levels. Stressed animals displayed anhedonia, and solely the PR mice continued to show higher levels of immobility in the OFT and FST. All stressed animals, regardless of the coping strategy, presented higher plasma corticosterone levels. In addition, stressed mice showed lower levels of tyrosine, dopamine, DOPAC, MHPG, kynurenine, kynurenic acid, and 5-HIAA levels but higher serotonin levels in the prefrontal cortex, not in the hippocampus. In conclusion, our results show that CSD induces differences in monoamine levels between brain areas, and these differences did not respond to the coping strategy adopted.
Frailty is an intermediate and reversible geriatric syndrome that often precedes dependence. Therefore, its identification is essential to prevent dependence. Several molecules have been proposed as ...biomarkers of frailty, but none of them have reached clinical practice. Recently, circular RNAs have emerged as new non-coding RNAs. Their regulatory role together with their high stability in biofluids makes them good candidates as biomarkers for various processes, but, to date, no study has characterized the expression of circRNA in frailty.
We studied RNA from leukocytes of 35 frails and 35 robust individuals. After RNA-Sequencing, circRNA detection was performed by CIRI2 and Circexplorer2 and differential expression analysis by DESeq2. Validation was performed by Quantitative-PCR. Linear Discriminant Analysis was performed to determine the best circRNA combination to discriminate frail from robust. In addition, CircRNA candidates were studied in 13 additional elder donors before and after a 3-month physical intervention. We found 89 differentially expressed circRNAs (p-value<0.05, FC>|1.5|) with frailty. Upregulation of hsa_circ_0007817, hsa_circ_0101802 and hsa_circ_0060527 in frail individuals was validated. The combination of hsa_circ_0079284, hsa_circ_0007817 and hsa_circ_0075737 levels showed a great biomarker value with a 95.9% probability of correctly classifying frail and robust individuals. Moreover, hsa_circ_0079284 levels decreased after physical intervention in concordance with an improvement in frailty scores.
This work describes for the first time a different expression pattern of circular RNA (circRNAs) between frail and robust individuals. Moreover, the level of some circRNAs is modulated after a physical intervention. These results suggest that they could be used as minimally invasive biomarkers of frailty.
Abstract
Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system, with higher prevalence in women, that leads to neurological disability. The disease course and clinical ...phenotype are highly variable, and therefore, biomarkers for the diagnosis, classification, monitoring of the disease and treatment assessment are needed. Studies have shown a dysregulation in the coding and non-coding RNAs and proposed some as biomarkers. However, still none of them have reached the clinical practice. Recently, circular RNAs (circRNAs) have emerged as new players in the transcriptome that hold a great potential as biomarkers in several diseases. Leukocytes from 30 MS patients and 20 healthy controls (HCs) were RNA-sequenced to study the linear and circular transcriptome. Differential expression analysis was performed by DESeq, and circRNA candidates were studied in a second cohort (70 MS and 46 HC) by RT-qPCR and in paired samples drawn during the relapse and remission phases (20 patients). Among the differentially expressed circRNAs, 96.1% are upregulated in patients compared with controls, but similar circRNA profiles are found between MS types. The same upregulation trend was observed in females but not in males or in the linear transcriptome. The upregulation of 6 circRNAs was validated, and a change in their expression was found between relapse and remission. The 6 circRNAs showed a good performance to discriminate patients from HC with a combined area under the curve of 0.852. There is global, specific and sex-dependent increase of circRNA expression in MS, and 6 circRNAs are proposed as potential biomarkers.
Multiple sclerosis (MS) is a chronic and neurodegenerative disease of the central nervous system (CNS) characterized by the immune mediated attack on axons and the subsequent demyelination. There is ...growing evidence that the gut microbiota of MS patients is altered; however, the connection between demyelination events and changes in the gut microbiota has not been determined. The objective of the current work was to characterize the microbial dysbiosis in two murine demyelinating models and to study the correlation between them. Concurrently, their suitability as predictors of microbial changes in MS patients was assessed. To this purpose, experimental autoimmune encephalomyelitis (EAE) and cuprizone (CPZ) models were induced in C57BL/6 mice that were monitored for 4 and 9 weeks, respectively. Fecal samples were collected during disease progression. Motor skill performance was evaluated by EAE scale measurement in EAE mice and demyelination by magnetic resonance imaging (MRI) in CPZ ones. EAE and CPZ mice revealed drastic microbial changes according to disease progression, adding a new layer of complexity to the understanding of demyelination and remyelination processes. Besides, the reported microbial changes replicate most of the characteristics that define the potential dysbiosis in MS patients. The controlled environment and stable diet that animals have in research centers offer an exceptional scenario to modify animal’s microbiota and provide opportunities to study host microbiota interplay with restrained conditions not achievable in human studies. Nevertheless the slight differences from murine model’s and patient’s microbiota should be considered in the design of studies aiming to modulate the microbiota.
ABO blood groups have recently been related to COVID19 infection. In the present work, we performed this analysis using data from 412 COVID19 patients and 17796 blood donors, all of them from ...Gipuzkoa, a region in Northern Spain. The results obtained confirmed this relation, in addition to showing a clear importance of group O as a protective factor in COVID19 disease, with an OR = 0.59 (CI95% 0.481-0.7177, p<0.0001) while A, B and AB are risk factors. ABO blood groups are slightly differently distributed in the populations and therefore these results should be replicated in the specific areas with a proper control population.
Differences in gene expression patterns have been documented not only in Multiple Sclerosis patients versus healthy controls but also in the relapse of the disease. Recently a new gene expression ...modulator has been identified: the microRNA or miRNA. The aim of this work is to analyze the possible role of miRNAs in multiple sclerosis, focusing on the relapse stage. We have analyzed the expression patterns of 364 miRNAs in PBMC obtained from multiple sclerosis patients in relapse status, in remission status and healthy controls. The expression patterns of the miRNAs with significantly different expression were validated in an independent set of samples. In order to determine the effect of the miRNAs, the expression of some predicted target genes of these were studied by qPCR. Gene interaction networks were constructed in order to obtain a co-expression and multivariate view of the experimental data. The data analysis and later validation reveal that two miRNAs (hsa-miR-18b and hsa-miR-599) may be relevant at the time of relapse and that another miRNA (hsa-miR-96) may be involved in remission. The genes targeted by hsa-miR-96 are involved in immunological pathways as Interleukin signaling and in other pathways as wnt signaling. This work highlights the importance of miRNA expression in the molecular mechanisms implicated in the disease. Moreover, the proposed involvement of these small molecules in multiple sclerosis opens up a new therapeutic approach to explore and highlight some candidate biomarker targets in MS.