Expression Profiling Analysis Reveals Key MicroRNA– mRNA Interactions in Early Retinal Degeneration in Retinitis Pigmentosa

PURPOSE. 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. Methods. miRNAs-mRNA interaction networks were generated for analysis of biological pathways involved in retinal degeneration. RESULTS. 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. CONCLUSIONS. This study contributes to our understanding of the etiology and progression of retinal degeneration.Supported by the Fundacion Jesus de Gangoiti Barrera and from the Basque Government's Department of Industry and Education Grants SAIOTEK-PE11BN002, PC12BN001, and DEPLC13/002 (AA, JRE); funds from Foundation of Patients of Retinitis Pigmentosa of Gipuzkoa (Retinosis Gipuzkoa Begisare) (OB); a grant from the Fundacion Mutua Madrilena (OB); Basque Government's Department of Education grants DEDUC14/309 (MEI), Diputacion Foral de Gipuzkoa DFG15/006 (MM-C), and ELKARTEK 16/014 (MM-C); National Institute of Health Carlos III (Instituto de Salud Carlos III) Grants ISCIII: CP10/00572 (JRE), PI13/02621 (JRE); an Intensificacion Contract (ALdM) from the Basque Government's Department of Industry; and a grant from the Foundation of Patients of Retinitis Pigmentosa of Gipuzkoa (Retinosis Gipuzkoa Begisare) (JRE). JR-E is a Miguel Servet II Fellow, National Institute of Health Carlos III (Instituto de Salud Carlos III), ISCIII: CPII16/00012

MiR-219a-5p Enriched Extracellular Vesicles Induce OPC Differentiation and EAE Improvement More Efficiently Than Liposomes and Polymeric Nanoparticles

Remyelination is a key aspect in multiple sclerosis pathology and a special effort is being made to promote it. However, there is still no available treatment to regenerate myelin and several strategies are being scrutinized. Myelination is naturally performed by oligodendrocytes and microRNAs have been postulated as a promising tool to induce oligodendrocyte precursor cell differentiation and therefore remyelination. Herein, DSPC liposomes and PLGA nanoparticles were studied for miR-219a-5p encapsulation, release and remyelination promotion. In parallel, they were compared with biologically engineered extracellular vesicles overexpressing miR-219a-5p. Interestingly, extracellular vesicles showed the highest oligodendrocyte precursor cell differentiation levels and were more effective than liposomes and polymeric nanoparticles crossing the blood–brain barrier. Finally, extracellular vesicles were able to improve EAE animal model clinical evolution. Our results indicate that the use of extracellular vesicles as miR-219a-5p delivery system can be a feasible and promising strategy to induce remyelination in multiple sclerosis patients.This work was supported by Carlos III Institute, (PI17/00189 and DTS15/00069), by Fondo Europeo de Desarrollo Regional—FEDER, by the Gipuzkoa Regional Council (DFG 15/006), by grant from the Basque Government (RIS3/DTS/2018222025), by the Department of Industry of the Basque Country (ELKARTEK 16/014), and the Spanish State Research Agency (SAF2017-87670-R) and Maria de Maeztu Units of Excellence Program Grant MDM-2017-0720). I.O.-Q., A.A. and L.I. were supported by the Department of Education of the Basque Government. IOQ and LAN were supported by EMBO short Term Fellowship Programme. LAN was supported by a Canadian graduate scholarship from the Canadian Institutes of Health Research (CGS-D CIHR).PRC was supported by Ikerbasque, the Basque Foundation for Science

Therapeutic Potential of Extracellular Vesicles for Demyelinating Diseases; Challenges and Opportunities

Multiple Sclerosis is a demyelinating disease of the central nervous system for which no remyelination therapy is available and alternative strategies are being tested. Extracellular vesicles (EVs) have emerged as players in physiological and pathological processes and are being proposed as therapeutic targets and mediators. More concretely, EVs have shown to be involved in myelination related processes such as axon-oligodendrocyte communication or oligodendrocyte precursor cell migration. In addition, EVs have been shown to carry genetic material and small compounds, and to be able to cross the Blood Brain Barrier. This scenario led scientists to test the ability of EVs as myelin regeneration promoters in demyelinating diseases. In this review we will address the use of EVs as remyelination promoters and the challenges and opportunities of this therapy will be discussed

The role of diet related short chain fatty acids in multiple sclerosis

Trabajo presentado en The 35th European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), celebrado en Estocolmo (Suecia), del 11 al 13 de septiembre de 2019[Background] There is growing evidence that gut microbiota is altered in multiple sclerosis (MS). Microbial dysbiosis is characterized by the increase in the genera Methanobrevibacter, Akkermansia, Acinetobacter, Pseudomonas, Blautia and Ruminococcus; and decrease in Sutterella, Faecalibacterium, Prevotella, Fusobacterium, Anaerostipes, Clostridium cluster XIVa and IV, Parabacteroides and Butyricimonas. However, the understanding of how these changes affects the disease development and evolution requires the functional study of the microbiota. Microorganisms produce thousands of biologically active compounds to communicate and interact with their host. Between them could be remarked the short chain fatty acids (SCFAs) as important mediators of the interaction with the neuroendocrine and immune systems. [Aims]: Characterize the profile of fecal SCFAs in MS patients and controls and determine its relation with the fiber intake and the disease. [Methods]: A total of 20 MS patients and 20 controls participated in the study. All participants filled a complete nutritional test and provide a fecal sample. SCFAs were extracted from feces using formic acid (20%v/v) and methanol. 2-Ethylbutyric acid was used as internal control. Analysis was performed using gas chromatography and the acids acetic, propionic, butyric, isobutyric, valeric, isovaleric and caproic were determined. [Results]: The amount of total SCFAs and every single acid evaluated was lower on MS patients regardless the fiber intake. The dominant SCFAs acetic, propionic and butyric were between 20 and 30% lower in MS patients than in controls; major differences were observed on caproic acid (43%). Besides, MS patients showed an altered SCFA profile in comparison with healthy controls, characterized by the higher representation of isobutyric, acetic and isovaleric acids and lower of butyric and caproic acids. Regarding the fiber intake the most affected SCFAs were the acetic and butyric acids. Interestingly the total SCFAs in MS patients seems to diminish with the disease evolution and EDSS score. [Conclusion]: MS patient’s microbiota produces lower levels of SCFAs and presents an altered SCFAs profile. Besides, differences are more pronounced when EDSS score increases and disease progresses. Those results provide valuable information for the evaluation of SCFAs as biomarkers of the disease evolution and the establishment of nutritional patterns directed to the increase of SCFAs producti

Whole-transcriptome analysis in peripheral blood mononuclear cells from patients with lipid-specific oligoclonal IgM band characterization reveals two circular RNAs and two linear RNAs as biomarkers of highly active disease

The presence of anti-myelin lipid-specific oligoclonal IgM bands (LS-OCMBs) has been defined as an accurate predictor of an aggressive evolution of multiple sclerosis. However, the detection of this biomarker is performed in cerebrospinal fluid, a quite invasive liquid biopsy. In the present study we aimed at studying the expression profile of miRNA, snoRNA, circRNA and linearRNA in peripheral blood mononuclear cells (PBMCs) from patients with lipid-specific oligoclonal IgM band characterization. We included a total of 89 MS patients, 47 with negative LS-OCMB status and 42 with positive status. Microarray (miRNA and snoRNA) and RNA-seq (circular and linear RNAs) were used to perform the profiling study in the discovery cohort and candidates were validated by RT-qPCR in the whole cohort. The biomarker potential of the candidates was evaluated by ROC curve analysis. RNA-seq and RT-qPCR validation revealed that two circular (hsa_circ_0000478 and hsa_circ_0116639) and two linear RNAs (IRF5 and MTRNR2L8) are downregulated in PBMCs from patients with positive LS-OCMBs. Finally, those RNAs show a performance of a 70% accuracy in some of the combinations. The expression of hsa_circ_0000478, hsa_circ_0116639, IRF5 and MTRNR2L8 might serve as minimally invasive biomarkers of highly active disease

Whole-transcriptome analysis in peripheral blood mononuclear cells from patients with lipid-specific oligoclonal IgM band characterization reveals two circular RNAs and two linear RNAs as biomarkers of highly active disease

The presence of anti-myelin lipid-specific oligoclonal IgM bands (LS-OCMBs) has been defined as an accurate predictor of an aggressive evolution of multiple sclerosis. However, the detection of this biomarker is performed in cerebrospinal fluid, a quite invasive liquid biopsy. In the present study we aimed at studying the expression profile of miRNA, snoRNA, circRNA and linearRNA in peripheral blood mononuclear cells (PBMCs) from patients with lipid-specific oligoclonal IgM band characterization. We included a total of 89 MS patients, 47 with negative LS-OCMB status and 42 with positive status. Microarray (miRNA and snoRNA) and RNA-seq (circular and linear RNAs) were used to perform the profiling study in the discovery cohort and candidates were validated by RT-qPCR in the whole cohort. The biomarker potential of the candidates was evaluated by ROC curve analysis. RNA-seq and RT-qPCR validation revealed that two circular (hsa_circ_0000478 and hsa_circ_0116639) and two linear RNAs (IRF5 and MTRNR2L8) are downregulated in PBMCs from patients with positive LS-OCMBs. Finally, those RNAs show a performance of a 70% accuracy in some of the combinations. The expression of hsa_circ_0000478, hsa_circ_0116639, IRF5 and MTRNR2L8 might serve as minimally invasive biomarkers of highly active disease

MiR-219a-5p enriched extracellular vesicles induce OPC differentiation and EAE improvement more efficiently than liposomes and polymeric nanoparticles

Remyelination is a key aspect in multiple sclerosis pathology and a special effort is being made to promote it. However, there is still no available treatment to regenerate myelin and several strategies are being scrutinized. Myelination is naturally performed by oligodendrocytes and microRNAs have been postulated as a promising tool to induce oligodendrocyte precursor cell differentiation and therefore remyelination. Herein, DSPC liposomes and PLGA nanoparticles were studied for miR-219a-5p encapsulation, release and remyelination promotion. In parallel, they were compared with biologically engineered extracellular vesicles overexpressing miR-219a-5p. Interestingly, extracellular vesicles showed the highest oligodendrocyte precursor cell differentiation levels and were more effective than liposomes and polymeric nanoparticles crossing the blood–brain barrier. Finally, extracellular vesicles were able to improve EAE animal model clinical evolution. Our results indicate that the use of extracellular vesicles as miR-219a-5p delivery system can be a feasible and promising strategy to induce remyelination in multiple sclerosis patients