High-Frequency Oscillations Recorded on the Scalp of Patients With Epilepsy Using Tripolar Concentric Ring Electrodes

Epilepsy is the second most prevalent neurological disorder (~1% prevalence) affecting ~67 million people worldwide with up to 75% from developing countries. The conventional electroencephalogram is plagued with artifacts from movements, muscles, and other sources. Tripolar concentric ring electrodes automatically attenuate muscle artifacts and provide improved signal quality. We performed basic experiments in healthy humans to show that tripolar concentric ring electrodes can indeed record the physiological alpha waves while eyes are closed. We then conducted concurrent recordings with conventional disc electrodes and tripolar concentric ring electrodes from patients with epilepsy. We found that we could detect high frequency oscillations, a marker for early seizure development and epileptogenic zone, on the scalp surface that appeared to become more narrow-band just prior to seizures. High frequency oscillations preceding seizures were present in an average of 35.5% of tripolar concentric ring electrode data channels for all the patients with epilepsy whose seizures were recorded and absent in the corresponding conventional disc electrode data. An average of 78.2% of channels that contained high frequency oscillations were within the seizure onset or irritative zones determined independently by three epileptologists based on conventional disc electrode data and videos

Structure of the RNA-dependent RNA polymerase P2 from the cystovirus φ8

\ua9 The Author(s) 2024.The replication of RNA viruses relies on the activity of RNA-dependent RNA polymerases (RdRps). Despite large variations in their genomic sequences, viral RdRps share a common architecture generally known as a closed right hand. The P2 polymerase of cystovirus φ6 is currently among the best characterized viral RdRps. This polymerase is responsible for carrying out both replication and transcription of the viral double-stranded RNA genome using de novo initiation. Despite the extensive biochemical and structural studies conducted on φ6 P2, further structural information on other cystoviral RdRps is crucial to elucidate the structural and functional diversity of viral RdRps. Here, we have determined the atomic X-ray structure of the RdRp P2 from the φ6-related cystovirus φ8 at 3\uc5 resolution. This structure completes the existing set of structural information on the φ8 polymerase complex and sheds light on the difference and similarities with related cystoviral RdRps

Ischemia–reperfusion impairs blood–brain barrier function and alters tight junction protein expression in the ovine fetus

The blood–brain barrier is a restrictive interface between the brain parenchyma and the intravascular compartment. Tight junctions contribute to the integrity of the blood–brain barrier. Hypoxic–ischemic damage to the blood–brain barrier could be an important component of fetal brain injury. We hypothesized that increases in blood–brain barrier permeability after ischemia depend upon the duration of reperfusion and that decreases in tight junction proteins are associated with the ischemia-related impairment in blood–brain barrier function in the fetus. Blood–brain barrier function was quantified with the blood-to-brain transfer constant (Ki) and tight junction proteins by Western immunoblot in fetal sheep at 127 days of gestation without ischemia, and 4, 24, or 48 h after ischemia. The largest increase in Ki (P \u3c 0.05) was 4 h after ischemia. Occludin and claudin-5 expressions decreased at 4 h, but returned toward control levels 24 and 48 h after ischemia. Zonula occludens-1 and -2 decreased after ischemia. Inverse correlations between Ki and tight junction proteins suggest that the decreases in tight junction proteins contribute to impaired blood–brain barrier function after ischemia. We conclude that impaired blood–brain barrier function is an important component of hypoxic–ischemic brain injury in the fetus, and that increases in quantitatively measured barrier permeability (Ki) change as a function of the duration of reperfusion after ischemia. The largest increase in permeability occurs 4 h after ischemia and blood–brain barrier function improves early after injury because the blood–brain barrier is less permeable 24 and 48 than 4 h after ischemia. Changes in the tight junction molecular composition are associated with increases in blood–brain barrier permeability after ischemia

An RRM-ZnF RNA recognition module targets RBM10 to exonic sequences to promote exon exclusion

RBM10 is an RNA-binding protein that plays an essential role in development and is frequently mutated in the context of human disease. RBM10 recognizes a diverse set of RNA motifs in introns and exons and regulates alternative splicing. However, the molecular mechanisms underlying this seemingly relaxed sequence specificity are not understood and functional studies have focused on 3΄ intronic sites only. Here, we dissect the RNA code recognized by RBM10 and relate it to the splicing regulatory function of this protein. We show that a two-domain RRM1–ZnF unit recognizes a GGA-centered motif enriched in RBM10 exonic sites with high affinity and specificity and test that the interaction with these exonic sequences promotes exon skipping. Importantly, a second RRM domain (RRM2) of RBM10 recognizes a C-rich sequence, which explains its known interaction with the intronic 3΄ site of NUMB exon 9 contributing to regulation of the Notch pathway in cancer. Together, these findings explain RBM10's broad RNA specificity and suggest that RBM10 functions as a splicing regulator using two RNA-binding units with different specificities to promote exon skipping

Toxic effects of low-level long-term inhalation exposures of rats to nickel oxide nanoparticles

Rats were exposed to nickel oxide nanoparticles (NiO-NP) inhalation at 0.23 ± 0.01 mg/m3 for 4 h a day 5 times a week for up to 10 months. The rat organism responded to this impact with changes in cytological and some biochemical characteristics of the bronchoalveolar lavage fluid along with a paradoxically little pronounced pulmonary pathology associated with a rather low chronic retention of nanoparticles in the lungs. There were various manifestations of systemic toxicity, including damage to the liver and kidneys; a likely allergic syndrome as indicated by some cytological signs; transient stimulation of erythropoiesis; and penetration of nickel into the brain from the nasal mucous membrane along the olfactory pathway. Against a picture of mild to moderate chronic toxicity of nickel, its in vivo genotoxic effect assessed by the degree of DNA fragmentation in nucleated blood cells (the RAPD test) was pronounced, tending to increasing with the length of the exposure period. When rats were given orally, in parallel with the toxic exposure, a set of innocuous substances with differing mechanisms of expected bioprotective action, the genotoxic effect of NiO-NPs was found to be substantially attenuated. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.For modeling chronic intoxication development under low-level but long-term inhalation exposures to NiO nanoparticles, the experiments were carried out on outbred white female rats from our own breeding colony with an initial body weight of 150–220 g, with a minimum of 12 animals in exposed and control groups. Rats were housed in conventional conditions, breathed unfiltered air, and were fed standard balanced food. The experiments were planned and implemented in accordance with the “International guiding principles for biomedical research involving animals” developed by the Council for International Organizations of Medical Sciences (1985) and were approved by the Ethics Committee of the Ekaterinburg Medical Research Center Medical for Prophylaxis and Health Protection in Industrial Workers

M6A-dependent RNA condensation underlies FUS autoregulation and can be harnessed for ALS therapy development

Mutations in the FUS gene cause aggressive amyotrophic lateral sclerosis (ALS-FUS). Beyond mRNA, FUS generates partially processed transcripts retaining introns 6 and 7. We demonstrate that these FUSint6&amp;7-RNA molecules form nuclear condensates, scaffolded by the highly structured intron 7 and associated with nuclear speckles. Using hybridization-proximity labeling proteomics, we show that the FUSint6&amp;7-RNA condensates are enriched for splicing factors and the N6-methyladenosine (m6A) reader YTHDC1. These ribonucleoprotein structures facilitate posttranscriptional FUS splicing and depend on m6A/YTHDC1 for integrity. In cells expressing mutant FUS, FUSint6&amp;7-RNAs become hypermethylated, which in turn stimulates their condensation and splicing. We further show that FUS protein is repelled by m6A. Thus, ALS-FUS mutations may cause abnormal activation of FUS posttranscriptional splicing through altered RNA methylation. Notably, ectopic expression of FUS intron 7 sequences dissolves endogenous FUSint6&amp;7-RNA condensates, down-regulating FUS mRNA and protein. Our findings reveal a condensation-dependent mechanism regulating FUS splicing, with possible therapeutic implications for ALS.</p