Biology subjects

Veno, M. T.

Publications and source records attributed to Veno, M. T..

7 recordsLinked to original sources

bioRxiv2024

EPILEPTOGENESIS INHIBITS THE CIRCADIAN CLOCK AND RESHAPES THE DIURNAL TRANSCRIPTOMIC RHYTHMICITY IN THE MOUSE HIPPOCAMPUS

Epileptogenesis is the process that leads the brain into epileptic activity. Clinical evidence shows that [~]90% of people with epilepsy present rhythmicity in the timing of their seizures presentation. However, whether the circadian clock is a key player during epileptogenesis remains unknown. Here, we triggered epileptogenesis in mice by the intra-amygdala injection of kainic acid and profiled by RNA sequencing their hippocampal diurnal mRNA rhythmicity. We show that epileptogenesis largely reshapes the hippocampal transcriptomic rhythmicity and that the molecular clock machinery is inhibited due to the disruption of the core clock gene Bmal1. We identified relevant dysregulated pathways and their dynamics in epileptogenesis, predicting a key role for microglial-driven neuroinflammation. We predicted the genes that Bmal1 is directly controlling over time. Finally, we sought for translational relevance evidence by performing RNA sequencing in hippocampal samples resected from patients with mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE-HS) and cross-analyzing datasets.

neuroscience↗

bioRxiv2023

ciRS-7-miR7 regulate ischemia induced neuronal death via glutamatergic signaling

Brain functionality relies on finely tuned regulation of gene expression by networks of non-coding RNAs (ncRNAs) such as the one composed by the circular RNA ciRS-7 (also known as CDR1as), the microRNA miR-7 and the long non-coding RNA Cyrano. Here we describe ischemia induced alterations in the ncRNA network both in vitro and in vivo and in transgenic mice lacking ciRS-7 or miR-7. Our data show that cortical neurons downregulate ciRS-7 and Cyrano and upregulate miR-7 expression upon ischemic insults. Mice lacking ciRS-7 show reduced lesion size and motor impairment, whilst the absence of miR-7 alone leads to an increase in the ischemia induced neuronal death. Moreover, miR-7 levels in pyramidal excitatory neurons regulate dendrite morphology and glutamatergic signaling suggesting a potential molecular link to the in vivo phenotype. Our data reveal that ciRS-7 and miR-7 contribute to the outcome of ischemic stroke and shed new light into the pathophysiological roles of intracellular networks of non-coding RNAs in the brain.

molecular biology↗

bioRxiv2022

MicroRNA-335-5p suppresses voltage-gated sodium channel expression and may be a target for seizure control

There remains an urgent need for new therapies for drug-resistant epilepsy (DRE). Sodium channel blockers are effective for seizure control in common forms of epilepsy, but loss of sodium channel function underlies some genetic forms of epilepsy. Approaches that provide bi-directional control of sodium channel expression are needed. MicroRNAs (miRNA) are small non-coding RNAs which negatively regulate gene expression. Here, we show that genome-wide miRNA screening of hippocampal tissue from a rat epilepsy model, mice treated with the novel anti-seizure medicine cannabidiol (CBD) and plasma from patients with DRE, converge on a single target, miR-335-5p. Pathway analysis on predicted and validated miR-335-5p targets identified multiple voltage-gated sodium channels (VGSCs). Intracerebroventricular injection of antisense oligonucleotides against miR-335-5p resulted in upregulation of Scn1a, Scn2a and Scn3a in the mouse brain and an increased action potential rising phase and greater excitability of hippocampal pyramidal neurons in brain slice recordings, consistent with VGSCs as functional targets of miR-335-5p. Blocking of miR-335-5p also increased voltage-gated sodium currents in human iPSC-derived neurons. Inhibition of miR-335-5p increased susceptibility to tonic-clonic seizures in the pentylenetetrazole seizure model, whereas AAV9-mediated overexpression of miR-335-5p reduced seizure severity and improved survival. These studies suggest modulation of miR-335-5p may be a means to regulate VGSCs and affect brain excitability and seizures. Changes to miR-335-5p may reflect compensatory mechanisms to control excitability and could provide new biomarker or therapeutic strategies for different types of drug-resistant epilepsy. Significance StatementDespite the clinical availability of over 30 anti-seizure medications (ASMs), around 30% of people with epilepsy do not achieve seizure freedom. MicroRNAs are small non-coding RNAs which negatively regulate protein expression by binding to target mRNAs. Here, we identified the brain-enriched miR-335-5p to be commonly altered in three heterogenous miRNA profiling datasets. Bi-directional modulation of miR-335-5p identified a potential homeostatic role of miR-335-5p in brain excitability involving voltage-gated sodium channels. Electrophysiological and in vivo approaches revealed pro-epileptic activity of miR-335-5p inhibition whereas overexpression of miR-335-5p resulted in anti-epileptic activity. Overall, targeting miR-335-5p could provide a new approach in the modulation of brain excitability, with possible therapeutic applications in drug-resistant epilepsies and other neurological diseases.

neuroscience↗

bioRxiv2019

A systems approach delivers a functional microRNA catalog and expanded targets for seizure suppression in temporal lobe epilepsy

MicroRNAs (miRNAs) are short noncoding RNAs that shape the gene expression landscape, including during the pathogenesis of temporal lobe epilepsy (TLE). In order to provide a full catalog of the miRNA changes that happen during experimental TLE, we sequenced Argonaute 2-loaded miRNAs in the hippocampus of three different animal models at regular intervals between the time of the initial precipitating insult to the establishment of spontaneous recurrent seizures. The commonly upregulated miRNAs were selected for a functional in vivo screen using oligonucleotide inhibitors. This revealed anti-seizure phenotypes upon inhibition of miR-10a-5p, miR-21a-5p and miR-142a-5p as well as neuroprotection-only effects for inhibition of miR-27a-3p and miR-431-5p. Proteomic data and pathway analysis on predicted and validated targets of these miRNAs indicated a role for TGF{beta} signaling in a shared seizure-modifying mechanism. Together, these results identify functional miRNAs in the hippocampus and a pipeline of new targets for seizure control in epilepsy.

neuroscience↗

bioRxiv2019

High-throughput RNA sequencing from paired lesional- and non-lesional skin reveals major alterations in the psoriasis circRNAome

BackgroundPsoriasis is a chronic inflammatory skin disease characterized by hyperproliferation and abnormal differentiation of keratinocytes. It is one of the most prevalent chronic inflammatory skin condition in adults worldwide, with a considerable negative impact on quality of life. Circular RNAs (circRNAs) are a recently identified type of non-coding RNA with diverse cellular functions related to their exceptional stability. In particular, some circRNAs can bind and regulate microRNAs (miRNAs), a group of RNAs that play a role in the pathogenesis of psoriasis. The aim of this study was to characterize the circRNAome in psoriasis and to assess potential correlations to miRNA expression patterns.\n\nResultsUsing high-throughput RNA-sequencing (RNA-seq) and NanoString nCounter technology, we found a substantial down-regulation of circRNA expression in lesional skin compared to non-lesional skin from psoriasis patients. We saw that this mainly applies to the epidermis by analyzing laser capture microdissected tissues and by RNA chromogenic in situ hybridization (CISH). We also found that the majority of the circRNAs were downregulated independent of their corresponding linear host genes. The observed downregulation of circRNAs in psoriasis was not due to altered expression levels of factors known to affect circRNA biogenesis, nor because lesional skin contained an increased number of inflammatory cells such as lymphocytes. Finally, we saw that the overall differences in available miRNA binding sites on the circRNAs between lesional and non-lesional skin did not correlate with differences in miRNA expression patterns.\n\nConclusionsWe have performed the first genome-wide circRNA profiling of paired lesional and non-lesional skin from psoriasis patients and revealed that circRNAs are much less abundant in the lesional samples. Whether this is a cause or a consequence of the disease remains to be revealed, however, we found no evidence that the loss of miRNA binding sites on the circRNAs could explain differences in miRNA expression reported between lesional and non-lesional skin.

molecular biology↗

bioRxiv2019

Nanopore sequencing of full-length circRNAs in human and mouse brains reveals circRNA-specific exon usage and intron retention

Circular RNA (circRNA) is a poorly understood class of non-coding RNAs, some of which have been shown to be functional important for cell proliferation and development. CircRNAs mainly derive from back splicing events of coding mRNAs, making it difficult to distinguish the internal exon composition of circRNA from the linearly spliced mRNA. To examine the global exon composition of circRNAs, we performed long-read sequencing of single molecules using nanopore technology for human and mouse brain-derived RNA. By applying an optimized circRNA enrichment protocol prior to sequencing, we were able to detect 7,834 and 10,975 circRNAs in human and mouse brain, respectively, of which 2,945 and 7,052 are not currently found in circBase. Alternative splicing was more prevalent in circRNAs than in linear spliced transcripts, and notably >200 not previously annotated exons were used in circRNAs. This suggests that properties associated with circRNA- specific features, e.g. the unusual back-splicing step during biogenesis, increased stability and /or their lack of translation, alter the general exon usage at steady state. We conclude that the nanopore sequencing technology provides a fast and reliable method to map the specific exon composition of circRNA.

genetics↗

bioRxiv2018

SMARTer single cell total RNA sequencing

Single cell RNA sequencing methods have been increasingly used to understand cellular heterogeneity. Nevertheless, most of these methods suffer from one or more limitations, such as focusing only on polyadenylated RNA, sequencing of only the 3 end of the transcript, an exuberant fraction of reads mapping to ribosomal RNA, and the unstranded nature of the sequencing data. Here, we developed a novel single cell strand-specific total RNA library preparation method addressing all the aforementioned shortcomings. Our method was validated on a microfluidics system using three different cancer cell lines undergoing a chemical or genetic perturbation. We demonstrate that our total RNA-seq method detects an equal or higher number of genes compared to classic polyA[+] RNA-seq, including novel and non-polyadenylated genes. The obtained RNA expression patterns also recapitulate the expected biological signal. Inherent to total RNA-seq, our method is also able to detect circular RNAs. Taken together, SMARTer single cell total RNA sequencing is very well suited for any single cell sequencing experiment in which transcript level information is needed beyond polyadenylated genes.

genomics↗