Nuclear envelope and chromatin choreography direct cellular differentiation

The nuclear envelope plays an indispensable role in the spatiotemporal organization of chromatin and transcriptional regulation during the intricate process of cell differentiation. This review outlines the distinct regulatory networks between nuclear envelope proteins, transcription factors and epigenetic modifications in controlling the expression of cell lineage-specific genes during differentiation. Nuclear lamina with its associated nuclear envelope proteins organize heterochromatin via Lamina-Associated Domains (LADs), proximal to the nuclear periphery. Since nuclear lamina is mechanosensitive, we critically examine the impact of extracellular forces on differentiation outcomes. The nuclear envelope is spanned by nuclear pore complexes which, in addition to their central role in transport, are associated with chromatin organization. Furthermore, mutations in the nuclear envelope proteins disrupt differentiation, resulting in developmental disorders. Investigating the underlying nuclear envelope controlled regulatory mechanisms of chromatin remodelling during lineage commitment will accelerate our fundamental understanding of developmental biology and regenerative medicine.

Changes in taste and odor sensitivities during repeated bicycle ergometer exercises

BACKGROUND

Effective nutritional support is essential for maintaining good performance during exercise. Taste and olfaction are key senses for food intake, and understanding how their sensitivities change during exercise is important for effective nutritional support. However, the effects of exercise on taste and odor sensitivities remain unclear. This study aimed to investigate changes in taste and odor sensitivities during repeated endurance exercise using a bicycle ergometer.

METHODS

A total of 20 women (mean age; 21.6 ± 0.2 years) participated in the study, completing four 60-minute segments, each comprising 50 minutes of bicycle ergometer exercise at an exercise intensity of 60% heart rate reserve and a 10-minute sensory test. The sensory tests were conducted five times in total: after each exercise segment and once before exercise as a control. Four concentrations (×0.5, ×0.75, ×1, and × 1.25) of a commercially available isotonic beverage were used as taste samples, and the subjects evaluated the taste intensity, preference, and odor intensity. Four types of food odorants were used as odor samples, and the subjects rated their preference. The subjects also reported their perceived fatigue levels during the taste and odor tests. Fatigue levels and taste intensity were rated using a 100-mm visual analogue scale, and taste and odor preferences and odor intensity were evaluated using a scoring method.

RESULTS

The degree of physical fatigue significantly increased with each successive bicycle exercise segment. The taste intensity and preference for beverages with higher concentrations increased as the number of exercise segments increased, showing a significant increase in taste intensity for the × 1.25 solution in the final segment compared with before the tests. On the other hand, no significant effect was observed on the perceived odor intensity of the isotonic beverages. Similarly, there was no significant effect on the preference for odor samples due to repeated exercise.

CONCLUSIONS

These results suggest that taste sensitivity may change with prolonged exercise. Additionally, since odor intensity and preference were not significantly affected by repeated exercise, odor sensitivity may be less impacted by exercise than taste sensitivity.

The role of beta band phase resetting in audio-visual temporal order judgment

The integration of auditory and visual stimuli is essential for effective language processing and social perception. The present study aimed to elucidate the mechanisms underlying audio-visual (A-V) integration by investigating the temporal dynamics of multisensory regions in the human brain. Specifically, we evaluated inter-trial coherence (ITC), a neural index indicative of phase resetting, through scalp electroencephalography (EEG) while participants performed a temporal-order judgment task that involved auditory (beep, A) and visual (flash, V) stimuli. The results indicated that ITC phase resetting was greater for bimodal (A + V) stimuli compared to unimodal (A or V) stimuli in the posterior temporal region, which resembled the responses of A-V multisensory neurons reported in animal studies. Furthermore, the ITC got lager as the stimulus-onset asynchrony (SOA) between beep and flash approached 0 ms. This enhancement in ITC was most clearly seen in the beta band (13-30 Hz). Overall, these findings highlight the importance of beta rhythm activity in the posterior temporal cortex for the detection of synchronous audiovisual stimuli, as assessed through temporal order judgment tasks.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11571-024-10183-0.

Altered effective connectivity within brain lesioned regions and cognitive impairment after stroke

Poststroke cognitive impairments (PSCI) reflect widespread network dysfunction due to structural damage, abnormal neural activity, or abnormal connections in affected brain regions. The exact influence of these lesioned regions on the related functional network and their role in PSCI remains unclear. We recruited 35 first-time stroke patients who had basal ganglia infarcts and PSCI, along with 29 age-matched healthy controls. We utilized T1-weighted imaging to inspect structural damage with regional gray matter volume (GMV). Resting-state fMRI data were utilized to examine spontaneous activities with regional Wavelet-ALFF metric, investigate dynamic functional connectivity (dFC) by seeding the region with damaged GMV, and further study effective connectivity within the abnormal dFC network and its impact on PSCI. In comparison to HC, patients showed significant reduced GMV in the bilateral Rolandic operculum (ROL), along with notable abnormal Wavelet-ALFF values in the right Precuneus (PCUN) and left Cerebellum_9 (CER9). Particularly, an abnormal dFC network seeded in the left ROL, demonstrating significantly differential between PSCI and HC groups and remaining consistent across all time windows, was observed. This abnormal dFC network comprised the left ROL as the seed region, the right ROL, bilateral PCUN, bilateral CER9, right Superior Temporal Gyrus (STG), and right Parahippocampal Gyrus (PHG). Notably, in patients, impaired functions across various cognitive domains significantly influenced the altered effective connections among the abnormal regions, particularly impacting the connections between structurally damaged regions and those with abnormal spontaneous activity. These findings suggest that altered effective connectivity networks within lesioned regions may contribute to deficits in various cognitive domains in PSCI.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11571-024-10209-7.

Biofilm-associated proteins: from the gut biofilms to neurodegeneration

Human microbiota form a biofilm with substantial consequences for health and disease. Numerous studies have indicated that microbial communities produce functional amyloids as part of their biofilm extracellular scaffolds. The overlooked interplay between bacterial amyloids and the host may have detrimental consequences for the host, including neurodegeneration. This work gives an overview of the biofilm-associated amyloids expressed by the gut microbiota and their potential role in neurodegeneration. It discusses the biofilm-associated proteins (BAPs) of the gut microbiota, maps the amyloidogenic domains of these proteins, and analyzes the presence of bap genes within accessory genomes linked with transposable elements. Furthermore, the evidence supporting the existence of amyloids in the gut are presented. Finally, it explores the potential interactions between BAPs and α-synuclein, extending the literature on amyloid cross-kingdom interactions. Based on these findings, this study propose that BAP amyloids act as transmissible catalysts, facilitating the misfolding, accumulation, and spread of α-synuclein aggregates. This review contributes to the understanding of complex interactions among the microbiota, transmissible elements, and host, which is crucial for developing novel therapeutic approaches to combat microbiota-related diseases and improve overall health outcomes.

Development of a Caco-2-based intestinal mucosal model to study intestinal barrier properties and bacteria-mucus interactions

The intestinal mucosal barrier is a dynamic system that allows nutrient uptake, stimulates healthy microbe-host interactions, and prevents invasion by pathogens. The mucosa consists of epithelial cells connected by cellular junctions that regulate the passage of nutrients covered by a mucus layer that plays an important role in host-microbiome interactions. Mimicking the intestinal mucosa for in vitro assays, particularly the generation of a mucus layer, has proven to be challenging. The intestinal cell-line Caco-2 is widely used in academic and industrial laboratories due to its capacity to polarize, form an apical brush border, and reproducibly grow into confluent cell layers in different culture systems. However, under normal culture conditions, Caco-2 cultures lack a mucus layer. Here, we demonstrate for the first time that Caco-2 cultures can form a robust mucus layer when cultured under air-liquid interface (ALI) conditions on Transwell inserts with addition of vasointestinal peptide (VIP) in the basolateral compartment. We demonstrate that unique gene clusters are regulated in response to ALI and VIP single stimuli, but the ALI-VIP combination treatment resulted in a significant upregulation of multiple mucin genes and proteins, including secreted MUC2 and transmembrane mucins MUC13 and MUC17. Expression of tight junction proteins was significantly altered in the ALI-VIP condition, leading to increased permeability to small molecules. Commensal Lactiplantibacillus plantarum bacteria closely associated with the Caco-2 mucus layer and differentially colonized the surface of the ALI cultures. Pathogenic Salmonella enterica were capable of invading beyond the mucus layer and brush border. In conclusion, Caco-2 ALI-VIP cultures provide an accessible and straightforward way to culture an in vitro intestinal mucosal model with improved biomimetic features. This novel in vitro intestinal model can facilitate studies into mucus and epithelial barrier functions and in-depth molecular characterization of pathogenic and commensal microbe-mucus interactions.

The roles of pleiotrophin in brain injuries: a narrative review of the literature

BACKGROUND

Pleiotrophin (PTN), a secreted multifunctional growth factor, is highly expressed in the developing brain. Recently, many studies have indicated that PTN participates in the development of brain and plays a neuroprotection after brain injury, especially promoting neuronal survival and neurite outgrowth, stimulating oligodendrocyte maturation and myelination, modulating neuroinflammation, and so on.

OBJECTIVE

However, no reviews comprehensively summarize the roles of PTN in brain injuries. Considering this, this review focuses on the roles and related regulatory pathways of PTN in brain injuries, what is known to date.

METHODS

PubMed and Embase databases have been searched, and related studies are compiled and summarized.

RESULTS

Our review has found PTN participates in the repairment of brain injuries, including hypoxic-ischemic brain injury, preterm white matter injury, traumatic brain injury, and neurodegenerative diseases, mainly based on animal data and small sample size studies. Besides, PTN interacts with receptors, such as, Z-type protein tyrosine phosphatase receptor and syndecan-3, regulating related pathways in these events.

CONCLUSION

It suggests PTN as a promising candidate for the treatment of brain injuries clinically. However, the evidence is early in its development. Further multi-center and large-sample studies are warranted to support our findings and determine the clinical value of PTN for treating brain injuries.

Alterations of synaptic plasticity and brain oscillation are associated with autophagy induced synaptic pruning during adolescence

Adolescent brain development is characterized by significant anatomical and physiological alterations, but little is known whether and how these alterations impact the neural network. Here we investigated the development of functional networks by measuring synaptic plasticity and neural synchrony of local filed potentials (LFPs), and further explored the underlying mechanisms. LFPs in the hippocampus were recorded in young (21 ~ 25 days), adolescent (1.5 months) and adult (3 months) rats. Long term potentiation (LTP) and neural synchrony were analyzed. The results showed that the LTP was the lowest in adolescent rats. During development, the theta coupling strength was increased progressively but there was no significant change of gamma coupling between young rats and adolescent rats. The density of dendrite spines was decreased progressively during development. The lowest levels of NR2A, NR2B and PSD95 were detected in adolescent rats. Importantly, it was found that the expression levels of autophagy markers were the highest during adolescent compared to that in other developmental stages. Moreover, there were more co-localization of autophagosome and PSD95 in adolescent rats. It suggests that autophagy is possibly involved in synaptic elimination during adolescence, and further impacts synaptic plasticity and neural synchrony.

Interkingdom signaling between gastrointestinal hormones and the gut microbiome

The interplay between the gut microbiota and gastrointestinal hormones plays a pivotal role in the health of the host and the development of diseases. As a vital component of the intestinal microecosystem, the gut microbiota influences the synthesis and release of many gastrointestinal hormones through mechanisms such as modulating the intestinal environment, producing metabolites, impacting mucosal barriers, generating immune and inflammatory responses, and releasing neurotransmitters. Conversely, gastrointestinal hormones exert feedback regulation on the gut microbiota by modulating the intestinal environment, nutrient absorption and utilization, and the bacterial biological behavior and composition. The distributions of the gut microbiota and gastrointestinal hormones are anatomically intertwined, and close interactions between the gut microbiota and gastrointestinal hormones are crucial for maintaining gastrointestinal homeostasis. Interventions leveraging the interplay between the gut microbiota and gastrointestinal hormones have been employed in the clinical management of metabolic diseases and inflammatory bowel diseases, such as bariatric surgery and fecal microbiota transplantation, offering promising targets for the treatment of dysbiosis-related diseases.

Sg-snn: a self-organizing spiking neural network based on temporal information

Neurodynamic observations indicate that the cerebral cortex evolved by self-organizing into functional networks, These networks, or distributed clusters of regions, display various degrees of attention maps based on input. Traditionally, the study of network self-organization relies predominantly on static data, overlooking temporal information in dynamic neuromorphic data. This paper proposes Temporal Self-Organizing (TSO) method for neuromorphic data processing using a spiking neural network. The TSO method incorporates information from multiple time steps into the selection strategy of the Best Matching Unit (BMU) neurons. It enables the coupled BMUs to radiate the weight across the same layer of neurons, ultimately forming a hierarchical self-organizing topographic map of concern. Additionally, we simulate real neuronal dynamics, introduce a glial cell-mediated Glial-LIF (Leaky Integrate-and-fire) model, and adjust multiple levels of BMUs to optimize the attention topological map.Experiments demonstrate that the proposed Self-organizing Glial Spiking Neural Network (SG-SNN) can generate attention topographies for dynamic event data from coarse to fine. A heuristic method based on cognitive science effectively guides the network's distribution of excitatory regions. Furthermore, the SG-SNN shows improved accuracy on three standard neuromorphic datasets: DVS128-Gesture, CIFAR10-DVS, and N-Caltech 101, with accuracy improvements of 0.3%, 2.4%, and 0.54% respectively. Notably, the recognition accuracy on the DVS128-Gesture dataset reaches 99.3%, achieving state-of-the-art (SOTA) performance.

Chemogenetic inhibition of corticotropin releasing hormone neurons in the paraventricular nucleus attenuates traumatic stress-induced deficit of NREM sleep, but not REM sleep in mice

Present study was aimed to elucidate the role of corticotropin releasing hormone (CRH) neurons located in the paraventricular nucleus of the hypothalamus (PVN) in the mechanisms of stress-induced insomnia. Experiments were done in the rodent model of traumatic stress, mice exposure to the predator (rat) odor. Sleep changes associated with this model of stress were first assessed in adult male C57BL/6J wild-type mice (n = 12). The effect of chemogenetic silencing of CRH neurons within the PVN on traumatic stress-induced insomnia was examined in adult male CRH-ires-Cre mice using designer receptors exclusively activated by designer drugs (DREADD) technology. Animals received bilateral injections of inhibitory DREADD vector AAV-hSyn-DIO-hM4Di-mCherry (n = 10) or control AAV-hSyn-DIO-mCherry virus (n = 10) into the PVN during surgery. The DREADD was activated by intraperitoneal injection of clozapine-N-oxide (CNO) prior to the induction of traumatic stress. The exposure of mice to rat odor induced strong long-lasting suppression of both non-rapid eye movement (NREM) and rapid eye movement (REM) sleep stages in both experiments. Selective suppression of CRH neurons within the PVN alleviated acute insomnia by significantly increasing the time spent in NREM sleep but it did not counteract the stress-induced deficit in REM sleep. These findings suggest a specific role for CRH-secreting neurons within the PVN in the suppression of NREM sleep during acute insomnia caused by predator odor stress, whereas REM sleep suppression is controlled by a different mechanism.

Maternal-infant probiotic transmission mitigates early-life stress-induced autism in mice

Autism, a disorder influenced by both genetic and environmental factors, presents significant challenges for prevention and treatment. While maternal-infant gut microbiota has been a focus in autism research, preventive strategies targeting maternal gut microbiota remain underexplored. This study demonstrates that prenatal probiotic intake can effectively prevent maternal separation-induced autistic-like behaviors in offspring without altering the embryonic neurodevelopment in mice. Using specific PCR primers and cross-fostering experiments, we traced the vertical transmission of probiotics, primarily via fecal/vaginal contamination. Early probiotic colonization conferred resilience against stress-induced gut pathogenic microbes and Th17-mediated peripheral inflammation while significantly inhibiting hypermyelination and neuroinflammation linked to systemic inflammation. Microbial metabolites like tyrosol and xanthurenic acid alleviated neuroinflammation and hypermyelination in vitro, though the causal relationship among neuroinflammation, hypermyelination, and autism in vivo requires further validation. These findings underscore the importance of the maternal-infant microbiota transmission window in autism prevention and highlight the clinical potential of prenatal probiotic interventions.

Deciphering the role of APOE in cerebral amyloid angiopathy: from genetic insights to therapeutic horizons

Cerebral amyloid angiopathy (CAA), characterized by the deposition of amyloid-β (Aβ) peptides in the walls of medium and small vessels of the brain and leptomeninges, is a major cause of lobar hemorrhage in elderly individuals. Among the genetic risk factors for CAA that continue to be recognized, the apolipoprotein E (APOE) gene is the most significant and prevalent, as its variants have been implicated in more than half of all patients with CAA. While the presence of the APOE ε4 allele markedly increases the risk of CAA, the ε2 allele confers a protective effect relative to the common ε3 allele. These allelic variants encode three APOE isoforms that differ at two amino acid positions. The primary physiological role of APOE is to mediate lipid transport in the brain and periphery; however, it has also been shown to be involved in a wide array of biological functions, particularly those involving Aβ, in which it plays a known role in processing, production, aggregation, and clearance. The challenges posed by the reliance on postmortem histological analyses and the current absence of an effective intervention underscore the urgency for innovative APOE-targeted strategies for diagnosing CAA. This review not only deepens our understanding of the impact of APOE on the pathogenesis of CAA but can also help guide the exploration of targeted therapies, inspiring further research into the therapeutic potential of APOE.

Regulation of dentate gyrus pattern separation by hilus ectopic granule cells

The dentate gyrus (DG) in hippocampus is reported to perform pattern separation, converting similar inputs into different outputs and thus avoiding memory interference. Previous studies have found that human and mice with epilepsy have significant pattern separation defects and a portion of adult-born granule cells (abGCs) migrate abnormally into the hilus, forming hilus ectopic granule cells (HEGCs). For the lack of relevant pathophysiological experiments, how HEGCs affect pattern separation remains unclear. Therefore, in this paper, we will construct the DG neuronal circuit and focus on discussing effects of HEGCs on pattern separation numerically. The obtained results showed that HEGCs impaired pattern separation efficiency since the sparse firing of granule cells (GCs) was destroyed. We provided new insights into the underlining mechanisms of HEGCs impairing pattern separation through analyzing two excitatory circuits: GC-HEGC-GC and GC-Mossy cell (MC)-GC, both of which involve the participation of HEGCs within the DG. It is revealed that the recurrent excitatory circuit GC-HEGC-GC formed by HEGCs mossy fiber sprouting significantly enhanced GCs activity, consequently disrupted pattern separation. However, another excitatory circuit had negligible effects on pattern separation due to the direct and indirect influences of MCs on GCs, which in turn led to the GCs sparse firing. Thus, HEGCs impair DG pattern separation mainly through the GC-HEGC-GC circuit and therefore ablating HEGCs may be one of the effective ways to improve pattern separation in patients with epilepsy.

Remimazolam induced cytotoxicity mediated through multiple stress pathways and acted synergistically with tyrosine kinase inhibitors in hepatocellular carcinoma

The primary treatment for hepatocellular carcinoma (HCC) involves surgical removal of the primary tumor, but this creates a favorable environment for the proliferation and spread of residual and circulating cancer cells. The development of remimazolam-based balanced anesthesia is crucial for future antitumor applications. It is important to understand the mechanisms of cytotoxicity for HCC in detail.

We performed cell viability analysis, western blotting analysis, reverse transcription-polymerase chain reaction analysis, and flow cytometry analysis in two HCC cell lines, HepG2 and Hep3B cells.

Our data demonstrated that remimazolam induced cytotoxicity by suppressing cell proliferation, inhibiting G1 phase progression, and affecting mitochondrial reactive oxygen species (ROS) levels, leading to apoptosis, DNA damage, cytosolic ROS elevation, lipid peroxidation, autophagy, mitochondrial depolarization, and endoplasmic reticulum stress. Inhibitors of apoptosis, autophagic cell death, and ferroptosis and a ROS scavenger failed to rescue cell death caused by remimazolam besylate. Our combination index revealed that remimazolam besylate has the potential to act as a sensitizer for targeted tyrosine kinase inhibitor therapy for HCC.

Our findings open up new possibilities for combinatory HCC therapy using remimazolam, leveraging its dual functional roles in surgery and drug therapy for liver cancers.

EIciRNAs in focus: current understanding and future perspectives

Circular RNAs (circRNAs) are a unique class of covalently closed single-stranded RNA molecules that play diverse roles in normal physiology and pathology. Among the major types of circRNA, exon-intron circRNA (EIciRNA) distinguishes itself by its sequence composition and nuclear localization. Recent RNA-seq technologies and computational methods have facilitated the detection and characterization of EIciRNAs, with features like circRNA intron retention (CIR) and tissue-specificity being characterized. EIciRNAs have been identified to exert their functions via mechanisms such as regulating gene transcription, and the physiological relevance of EIciRNAs has been reported. Within this review, we present a summary of the current understanding of EIciRNAs, delving into their identification and molecular functions. Additionally, we emphasize factors regulating EIciRNA biogenesis and the physiological roles of EIciRNAs based on recent research. We also discuss the future challenges in EIciRNA exploration, underscoring the potential for novel functions and functional mechanisms of EIciRNAs for further investigation.

Visual image reconstructed without semantics from human brain activity using linear image decoders and nonlinear noise suppression

In recent years, substantial strides have been made in the field of visual image reconstruction, particularly in its capacity to generate high-quality visual representations from human brain activity while considering semantic information. This advancement not only enables the recreation of visual content but also provides valuable insights into the intricate processes occurring within high-order functional brain regions, contributing to a deeper understanding of brain function. However, considering fusion semantics in reconstructing visual images from brain activity involves semantic-to-image guide reconstruction and may ignore underlying neural computational mechanisms, which does not represent true reconstruction from brain activity. In response to this limitation, our study introduces a novel approach that combines linear mapping with nonlinear noise suppression to reconstruct visual images perceived by subjects based on their brain activity patterns. The primary challenge associated with linear mapping lies in its susceptibility to noise interference. To address this issue, we leverage a flexible denoised deep convolutional neural network, which can suppress noise from linear mapping. Our investigation encompasses linear mapping as well as the training of shallow and deep autoencoder denoised neural networks, including a pre-trained, state-of-the-art denoised neural network. The outcome of our study reveals that combining linear image decoding with nonlinear noise reduction significantly enhances the quality of reconstructed images from human brain activity. This suggests that our methodology holds promise for decoding intricate perceptual experiences directly from brain activity patterns without semantic information. Moreover, the model has strong neural explanatory power because it shares structural and functional similarities with the visual brain.

Novel role of FTO in regulation of gut-brain communication via Desulfovibrio fairfieldensis-produced hydrogen sulfide under arsenic exposure

Fat mass and obesity-associated protein (FTO) is the key demethylase that reverses the abnormally altered N6-methyladenosine (m6A) modification in eukaryotic cells under environmental pollutants exposure. Arsenic is an environmental metalloid and can cause severe symptoms in human mainly through drinking water. However, there is no specific treatment for its toxic effects due to the uncovered mechanisms. We previously revealed that exposure to arsenic increased the level of m6A via down-regulation of FTO, which might serve as a potential target for intervention against arsenic-related disorders. In this study, our results demonstrated that chronic exposure to arsenic significantly disrupted the intestinal barrier and microenvironment. Also, this administration resulted in the enhancement of m6A modification and the reduction of FTO expression in the intestine. By using both CRISPR/Cas9-based FTO knock-in strategy and adeno-associated virus (AAV)-mediated overexpression of FTO in the intestine, we established for the first time that up-regulation of FTO remarkably ameliorated arsenic-induced disruption of intestinal barriers and altered microenvironment of mice. We also firstly identified a dominant gut microbial species, Desulfovibrio fairfieldensis, which was sharply reduced in arsenic-exposed mice, was able to proceed arsenic-induced neurobehavioral impairments by declining the levels of its major metabolite hydrogen sulfide. Administration of Desulfovibrio fairfieldensis could significantly alleviate the neurotoxicity of arsenic. Intriguingly, the beneficial effects of FTO against arsenic neurotoxicity possibly occurred through a novel gut-brain communication via Desulfovibrio fairfieldensis and its produced hydrogen sulfide. Collectively, these findings will provide new ideas for understanding the mechanisms of arsenic-induced toxic effects from a gut-brain communication perspective, and will assist the development of explicit intervention strategy via regulation of a new potential target FTO for prevention and treatment against arsenic-related both intestinal and neurological disorders.

Neural oscillations predict flow experience

Flow experience, characterized by immersion in the activity at hand, provides a motivational boost and promotes positive behaviors. However, the oscillatory representations of flow experience are still poorly understood. In this study, the difficulty of the video game was adjusted to manipulate the individual's personalized flow or non-flow state, and EEG data was recorded throughout. Our results show that, compared to non-flow tasks, flow tasks exhibit higher theta power, moderate alpha power, and lower beta power, providing evidence for a focused yet effortless brain pattern during flow. Additionally, we employed Lasso regression to predict individual subjective flow scores based on neural data, achieving a correlation coefficient of 0.571 (p < 0.01) between the EEG-predicted scores and the actual self-reported scores. Our findings offer new insights into the oscillatory representation of flow and emphasize that flow, as a measure of individual experience quality, can be objectively and quantitatively predicted through neural oscillations.

Unraveling the functional complexity of the locus coeruleus-norepinephrine system: insights from molecular anatomy to neurodynamic modeling

The locus coeruleus (LC), as the primary source of norepinephrine (NE) in the brain, is central to modulating cognitive and behavioral processes. This review synthesizes recent findings to provide a comprehensive understanding of the LC-NE system, highlighting its molecular diversity, neurophysiological properties, and role in various brain functions. We discuss the heterogeneity of LC neurons, their differential responses to sensory stimuli, and the impact of NE on cognitive processes such as attention and memory. Furthermore, we explore the system's involvement in stress responses and pain modulation, as well as its developmental changes and susceptibility to stressors. By integrating molecular, electrophysiological, and theoretical modeling approaches, we shed light on the LC-NE system's complex role in the brain's adaptability and its potential relevance to neurological and psychiatric disorders.

SARS-CoV-2 and HCoV-OC43 regulate host m6A modification via activation of the mTORC1 signalling pathway to facilitate viral replication

N6-methyladenosine (m6A) is the most prevalent post-transcriptional modification in eukaryotic RNA and is also present in various viral RNAs, where it plays a crucial role in regulating the viral life cycle. However, the molecular mechanisms through which viruses regulate host RNA m6A methylation are not fully understood. In this study, we reveal that SARS-CoV-2 and HCoV-OC43 infection enhance host m6A modification by activating the mTORC1 signalling pathway. Specifically, the viral non-structural protein nsp14 upregulates the expression of S-adenosylmethionine synthase MAT2A in an mTORC1-dependent manner. This mTORC1-MAT2A axis subsequently stimulates the synthesis of S-adenosylmethionine (SAM). The increase of SAM then enhances the m6A methylation of host RNA and facilitates viral replication. Our findings uncover a molecular mechanism by which viruses regulate host m6A methylation and provide insights into how SARS-CoV-2 hijacks host cellular epitranscriptomic modifications to promote its replication.

N6-methyladenosine modification of THBS1 induced by affluent WTAP promotes Graves' ophthalmopathy progression through glycolysis to affect Th17/Treg balance

Graves' ophthalmopathy (GO) obvious manifestation is the imbalance of Th17/Treg. N6-methyladenosine (m6A) methylation is an important regulator of Th17/Treg balance. However, few reports narrate how m6A regulators mediate the role of genes in GO progression. We explored the m6A modification of THBS1 mediated by WTAP, and the mechanism by which THBS1 regulated glycolysis and Th17/Treg balance. A total of 12 peripheral blood (4 GO samples, 4 GH samples, and 4 health samples) were collected to measure the percentage of Th17/Treg in monocytes by flow cytometry. RNA sequencing (RNA-seq) combined with MeRIP sequencing (MeRIP-seq) was used to screen differentially expressed and methylated genes. MeRIP-qPCR was performed to evaluate the m6A abundance of THBS1 after WTAP silencing. Glycolysis of CD4+ T cells was reflected by the lactate content and glucose uptake. The number of Th17 cells was increased in GO peripheral blood, whereas the Treg cells decreased. RNA-seq acquired 679 differentially expressed genes (308 up-regulated, and 371 down-regulated) in the CD4+ T cells of GO compared to healthy control. MeRIP-seq identified 3277 m6A peaks between the GO group and the healthy control group, corresponding with 2744 genes (1143 hypermethylated and 1601 hypomethylated). Combined analysis of RNA-seq and MeRIP-seq showed 81 hypermethylated and up-regulated genes. Among the six candidate genes in the PI3K-signaling pathway, THBS1 was the most significantly differentially expressed and hypermethylated. THBS1 silencing resulted in decreased lactate content and glucose uptake in CD4+ T cells. WTAP was significantly upregulated in CD4+ T cells of GO, and WTAP silencing significantly reduced m6A abundance and expression of THBS1. Upregulated and hypermethylated THBS1 mediated by WTAP promoted glycolysis of CD4+ T cells, affected Th17/Treg balance, and facilitated GO progression. We provided a novel potential target for GO treatment and revealed the molecular mechanism of WTAP and THBS1 in GO under the m6A perspective.

Sleep timing in flies from "adolescence" to adulthood

The aim of the present study was to assess sleep timing in Drosophila melanogaster at different ages, within the setting of an enforced schedule of varying light-dark stimuli, simulating light exposure variations between four typical office working days and one free day spent outside by a human, for a total of 30 days. Locomotor activity recording started when male flies were 3 days old. Flies exhibited a bimodal activity pattern, with a morning and an evening peak, and clear anticipation of the lights on and lights off transitions. From experimental day 10 (i.e. 12-day-old flies) onwards, a decrease in activity counts/increase in sleep amount were observed. On free days, a rise in activity counts and a reduction in sleep amount during the lights on interval was observed and was also present, albeit less obvious, on the subsequent working day during the lights off interval. A progressive delay in sleep onset was observed in the first days of the experiment, peaking on day 4 (i.e. 6-day-old flies), after which sleep onset timing gradually advanced. A delay in sleep offset was also observed for the first 13 days of the experiment, after which sleep offset stabilized. In conclusion, 'adolescent' flies exhibited changes in sleep timing that were reminiscent of those of human adolescents.

Resveratrol alleviates depressive-like behavior via the activation of SIRT1/NF-κB signaling pathway in microglia

BACKGROUND

Currently, the pathogenesis of depression remains poorly understood, leading to many patients receiving ineffective treatment. Resveratrol has demonstrated beneficial effects in the prevention and treatment of depression. However, it remains unknown whether resveratrol administration can counteract depression-like behaviors by regulating the SIRT1/NF-κB signaling pathway.

METHODOLOGY/PRINCIPAL FINDINGS

Male C57BL/6 mice were randomly assigned to a control group, a depression group, and a resveratrol group. The depression model was established using chronic unpredictable mild stress (CUMS) for 5 weeks. Behavioral tests were conducted to assess depressive-like behaviors. The expression levels of SIRT1 and NF-κB in the hippocampus of mice and BV2 microglial cells were measured. After 5 weeks of modeling, the results indicated that mice in the depression group exhibited significant depressive-like behaviors and inhibited activation of the SIRT1/NF-κB signaling pathway. In contrast, resveratrol administration effectively reversed these changes. Results from in vitro experiments showed that LPS stimulation increased microglial activity and downregulated the SIRT1/NF-κB signaling pathway in microglia; however, resveratrol treatment mitigated these effects.

CONCLUSIONS/SIGNIFICANCE

Our findings suggested that resveratrol can alleviate CUMS-induced depression-like behaviors via the activation of the Sirt1/NF-κB pathway in microglia.

Machine learning-assisted design of immunomodulatory lipid nanoparticles for delivery of mRNA to repolarize hyperactivated microglia

Regulating inflammatory microglia presents a promising strategy for treating neurodegenerative and autoimmune disorders, yet effective therapeutic agents delivery to these cells remains a challenge. This study investigates modified lipid nanoparticles (LNP) for mRNA delivery to hyperactivated microglia, particularly those with pro-inflammatory characteristics, utilizing supervised machine learning (ML) classifiers. We developed and screened a library of 216 LNP formulations with varying lipid compositions, N/P ratios, and hyaluronic acid (HA) modifications. The transfection efficiency of eGFP mRNA was assessed in the BV-2 murine microglia cell line under different immunological states, including resting and activated conditions (LPS-activated and IL4/IL13-activated). ML-guided morphometric analysis tracked the phenotypes of various microglia subtypes before and after transfection. Four supervised ML classifiers were investigated to predict transfection efficiency and phenotypic changes based on LNP design parameters. The Multi-Layer Perceptron (MLP) neural network emerged as the best-performing model, achieving weighted F1-scores ≥0.8. While it accurately predicted responses from LPS-activated and resting cells, it struggled with IL4/IL13-activated cells. The MLP model was validated by predicting the performance of four unseen LNP formulations delivering eGFP mRNA to LPS-activated BV2 cells. HA-LNP2 emerged as optimal formulation for delivering target IL10 mRNA, effectively suppressing inflammatory phenotypes, evidenced by shifts in cell morphology, increased IL10 expression, and reduced TNF-α levels. We also evaluated HA-LNP2 on LPS-activated human iPSC-derived microglia, confirming its efficacy in modulating inflammatory responses. This study highlights the potential of tailored LNP design and ML techniques to enhance mRNA therapy for neuroinflammatory disorders by leveraging carrier's immunogenic properties to modulate microglial responses.

Role of iron in brain development, aging, and neurodegenerative diseases

It is now understood that iron crosses the blood-brain barrier via a complex metabolic regulatory network and participates in diverse critical biological processes within the central nervous system, including oxygen transport, energy metabolism, and the synthesis and catabolism of myelin and neurotransmitters. During brain development, iron is distributed throughout the brain, playing a pivotal role in key processes such as neuronal development, myelination, and neurotransmitter synthesis. In physiological aging, iron can selectively accumulate in specific brain regions, impacting cognitive function and leading to intracellular redox imbalance, mitochondrial dysfunction, and lipid peroxidation, thereby accelerating aging and associated pathologies. Furthermore, brain iron accumulation may be a primary contributor to neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Comprehending the role of iron in brain development, aging, and neurodegenerative diseases, utilizing iron-sensitive Magnetic Resonance Imaging (MRI) technology for timely detection or prediction of abnormal neurological states, and implementing appropriate interventions may be instrumental in preserving normal central nervous system function.

The effects of stress on working-memory-related prefrontal processing: an fNIRS study

Acute stress causes a shift from executive to automated behavior. A key executive function suffering from this shift is working memory. Working memory is mainly negatively affected in the first 10 and more than 25 minutes after acute stress. These phases coincide with increased central levels of noradrenaline and cortisol. Increased levels of both hormones can cause a relative deactivation in prefrontal areas related to working memory processing. However, so far, there is little research that investigates the complete relationship between acute stress and resulting changes in stress hormones, neural activation, and working memory processing, over time. In this study, we used functional near-infrared spectroscopy to measure prefrontal activity during an nback task in a stress (28 subjects, 7 female/21 male) and a control group (28 subjects, 10 female/18 male) once (20 minutes) before and twice (4 and 24 minutes) after a socially evaluated cold pressor test or a warm water control condition. Additionally, we regularly measured changes in salivary cortisol and α-amylase (a correlate of central noradrenaline) during the experiment. While salivary cortisol was increased starting 14 minutes after acute stress, no effect of stress on salivary α-amylase or working memory performance was found. On a neural level, we found a marginally stronger decline in 3-back-related prefrontal activity from the first to the third measurement point in the stress than in the control group. These results present tentative evidence for a negative effect of acute stress on working-memory-related prefrontal processing mediated by central cortisol levels.

Exploring the versatility of Drosophila melanogaster as a model organism in biomedical research: a comprehensive review

Drosophila melanogaster is a highly versatile model organism that has profoundly advanced our understanding of human diseases. With more than 60% of its genes having human homologs, Drosophila provides an invaluable system for modelling a wide range of pathologies, including neurodegenerative disorders, cancer, metabolic diseases, as well as cardiac and muscular conditions. This review highlights key developments in utilizing Drosophila for disease modelling, emphasizing the genetic tools that have transformed research in this field. Technologies such as the GAL4/UAS system, RNA interference (RNAi) and CRISPR-Cas9 have enabled precise genetic manipulation, with CRISPR-Cas9 allowing for the introduction of human disease mutations into orthologous Drosophila genes. These approaches have yielded critical insights into disease mechanisms, identified novel therapeutic targets and facilitated both drug screening and toxicological studies. Articles were selected based on their relevance, impact and contribution to the field, with a particular focus on studies offering innovative perspectives on disease mechanisms or therapeutic strategies. Our findings emphasize the central role of Drosophila in studying complex human diseases, underscoring its genetic similarities to humans and its effectiveness in modelling conditions such as Alzheimer's disease, Parkinson's disease and cancer. This review reaffirms Drosophila's critical role as a model organism, highlighting its potential to drive future research and therapeutic advancements.

RNA-binding protein quaking: a multifunctional regulator in tumour progression

BACKGROUND

Quaking (QKI) is a member of the signal transduction and activators of RNA (STAR) family, performing a crucial multifunctional regulatory role in alternative splicing, mRNA precursor processing, mRNA transport and localization, mRNA stabilization, and translation during tumour progression. Abnormal QKI expression or fusion mutations lead to aberrant RNA and protein expression, thereby promoting tumour progression. However, in many types of tumour, QKI played a role as tumour suppressor, the regulatory role of QKI in tumour progression remains ambiguous.

OBJECTIVES

This review aims to analyze the isoform and function of QKI, the impact of QKI-regulated gene expression or signalling pathway alterations on tumour progression, and its potential clinical applications as a predictive marker or target for tumour therapy.

METHODS

We reviewed recent studies and summarized the function of QKI alteration in tumour progression.

RESULTS

QKI mediate post-transcriptional gene regulation including alternative splicing, polyadenylation, mRNA stabilization, mRNA subcellular location, and noncoding RNA by binding to the QRE elements of targeted nucleotide. The dysregulation of QKI is intricately correlated to tumour proliferation, metastasis, angiogenesis, tumor stem cells, the tumour microenvironment, and treatment sensitivity, and represents as a potential biological predictor in tumour diagnosis and prognosis.

CONCLUSIONS

QKI play a critical role as tumour suppressor or an oncogene in tumour progression due to the different splicing sites and transcripts with various tumour subtype or tumor micorenvironment. Ongoing research about QKI's functions and mechanisms persist is required to conduct for better understanding the role of QKI in tumour regulation.

Reconstruction and application of multilayer brain network for juvenile myoclonic epilepsy based on link prediction

Juvenile myoclonic epilepsy (JME) exhibits abnormal functional connectivity of brain networks at multiple frequencies. We used the multilayer network model to address the heterogeneous features at different frequencies and assess the mechanisms of functional integration and segregation of brain networks in JME patients. To address the possibility of false edges or missing edges during network construction, we combined multilayer networks with link prediction techniques. Resting-state functional magnetic resonance imaging (rs-fMRI) data were procured from 40 JME patients and 40 healthy controls. The Multilayer Network framework is utilized to integrate information from different frequency bands and to fuse similarity metrics for link prediction. Finally, calculate the entropy of the multiplex degree and multilayer clustering coefficient of the reconfigured multilayer frequency network. The results showed that the multilayer brain network of JME patients had significantly reduced ability to integrate and separate information and significantly correlated with severity of JME symptoms. This difference was particularly evident in default mode network (DMN), motor and somatosensory network (SMN), and auditory network (AN). In addition, significant differences were found in the precuneus, suboccipital gyrus, middle temporal gyrus, thalamus, and insula. Results suggest that JME patients have abnormal brain function and reduced cross-frequency interactions. This may be due to changes in the distribution of connections within and between the DMN, SMN, and AN in multiple frequency bands, resulting in unstable connectivity patterns. The generation of these changes is related to the pathological mechanisms of JME and may exacerbate cognitive and behavioral problems in patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11571-024-10191-0.

Influences of physical stimulations on the migration and differentiation of Schwann cells involved in peripheral nerve repair

Peripheral nerve injury repair has always been a research concern of scientists. At the tissue level, axonal regeneration has become a research spotlight in peripheral nerve repair. Through transplantation of autologous nerve grafts or other emerging biomaterials functional recovery after facial nerve injury is not ideal in clinical scenarios. Great strides have been made to improve facial nerve repair at the micro-cellular level. Physical stimulation techniques can trigger Schwann cells (SCs) to migrate and differentiate into cells required for peripheral nerve repair. Classified by the sources of physical stimulations, SCs repair peripheral nerves through galvanotaxis, magnetotaxis and durotaxis. This article summarized the activation, directional migration and differentiation of SCs induced by physical stimulations, thus providing new ideas for the research of peripheral nerve repair.

Neuroenhancement by repetitive transcranial magnetic stimulation (rTMS) on DLPFC in healthy adults

The term "neuroenhancement" describes the enhancement of cognitive function associated with deficiencies resulting from a specific condition. Nevertheless, there is currently no agreed-upon definition for the term "neuroenhancement", and its meaning can change based on the specific research being discussed. As humans, our continual pursuit of expanding our capabilities, encompassing both cognitive and motor skills, has led us to explore various tools. Among these, repetitive Transcranial Magnetic Stimulation (rTMS) stands out, yet its potential remains underestimated. Historically, rTMS was predominantly employed in studies focused on rehabilitation objectives. A small amount of research has examined its use on healthy subjects with the goal of improving cognitive abilities like risk-seeking, working memory, attention, cognitive control, learning, computing speed, and decision-making. It appears that the insights gained in this domain largely stem from indirect outcomes of rehabilitation research. This review aims to scrutinize these studies, assessing the effectiveness of rTMS in enhancing cognitive skills in healthy subjects. Given that the dorsolateral prefrontal cortex (DLPFC) has become a popular focus for rTMS in treating psychiatric disorders, corresponding anatomically to Brodmann areas 9 and 46, and considering the documented success of rTMS stimulation on the DLPFC for cognitive improvement, our focus in this review article centers on the DLPFC as the focal point and region of interest. Additionally, recognizing the significance of theta burst magnetic stimulation protocols (TBS) in mimicking the natural firing patterns of the brain to modulate excitability in specific cortical areas with precision, we have incorporated Theta Burst Stimulation (TBS) wave patterns. This inclusion, mirroring brain patterns, is intended to enhance the efficacy of the rTMS method. To ascertain if brain magnetic stimulation consistently improves cognition, a thorough meta-analysis of the existing literature has been conducted. The findings indicate that, after excluding outlier studies, rTMS may improve cognition when compared to appropriate control circumstances. However, there is also a considerable degree of variation among the researches. The navigation strategy used to reach the stimulation site and the stimulation location are important factors that contribute to the variation between studies. The results of this study can provide professional athletes, firefighters, bodyguards, and therapists-among others in high-risk professions-with insightful information that can help them perform better on the job.

Beta-band oscillations and spike-local field potential synchronization in the motor cortex are correlated with movement deficits in an exercise-induced fatigue mouse model

Fatigue, a complex and multifaceted symptom, profoundly influences quality of life, particularly among individuals suffering from chronic medical conditions or neurological disorders. This symptom not only exacerbates existing conditions but also hinders daily functioning, thereby perpetuating a vicious cycle of worsening symptoms and reduced physical activity. Given the pivotal role of the motor cortex (M1) in coordinating and executing voluntary movements, understanding how the cortex regulates fatigue is crucial. Despite its importance, the neural mechanisms underlying fatigue remain inadequately explored. In this study, we employed electrophysiological recordings in the M1 region of mice to investigate how excitation-inhibition dynamics and neural oscillations are regulated during exercise-induced fatigue. We observed that fatigue led to decreased voluntary physical activity and cognitive performance, manifesting as reduced running wheel distance, mean speed, exercise intensity, and exploratory behaviour. At the neural level, we detected increased firing frequencies for M1 neurons, including both pyramidal neurons and interneurons, along with heightened beta-band oscillatory activity and stronger coupling between beta-band oscillations and interneurons. These findings enhance our understanding of the mechanisms underlying fatigue, offering insights into behavioural, excitability, and oscillatory changes. The results of this study could pave the way for the development of novel intervention strategies to combat fatigue.

Formation of cognitive maps in large-scale environments by sensorimotor integration

Hippocampus in the mammalian brain supports navigation by building a cognitive map of the environment. However, only a few studies have investigated cognitive maps in large-scale arenas. To reveal the computational mechanisms underlying the formation of cognitive maps in large-scale environments, we propose a neural network model of the entorhinal-hippocampal neural circuit that integrates both spatial and non-spatial information. Spatial information is relayed from the grid units in medial entorhinal cortex (MEC) by integrating multimodal sensory-motor signals. Non-spatial, such as object, information is imparted from the visual units in lateral entorhinal cortex (LEC) by encoding visual scenes through a deep neural network. The synaptic weights from the grid units and the visual units to the place units in the hippocampus are learned by a competitive learning rule. We simulated the model in a large box maze. The place units in the model form irregularly-spaced multiple fields across the environment. When the strength of visual inputs is dominant, the responses of place units become conjunctive and egocentric. These results point to the key role of the hippocampus in balancing spatial and non-spatial information relayed via LEC and MEC.

Multi-level cognitive state classification of learners using complex brain networks and interpretable machine learning

Identifying the cognitive state can help educators understand the evolving thought processes of learners, and it is important in promoting the development of higher-order thinking skills (HOTS). Cognitive neuroscience research identifies cognitive states by designing experimental tasks and recording electroencephalography (EEG) signals during task performance. However, most of the previous studies primarily concentrated on extracting features from individual channels in single-type tasks, ignoring the interconnection across channels. In this study, three learning activities (i.e., video watching activity, keyword extracting activity, and essay creating activity) were designed based on a revised Bloom's taxonomy and the Interactive-Constructive-Active-Passive framework and used with 31 college students. The EEG signals were recorded when they were engaged in these activities. First, whole-brain network temporal dynamics were characterized by EEG microstate sequence analysis. Such dynamic changes rely on learning activity and corresponding functional brain systems. Subsequently, phase locking value was used to construct synchrony-based functional brain networks. The network characteristics were extracted to be inputted into different machine learning classifiers: Support Vector Machine, K-Nearest Neighbour, Random Forest, and eXtreme Gradient Boosting (XGBoost). XGBoost showed superior performance in the classification of cognitive states, with an accuracy of 88.07%. Furthermore, SHapley Additive exPlanations (SHAP) was adopted to reveal the connections between different brain regions that contributed to the classification of cognitive state. SHAP analysis reveals that the connections in the frontal, temporal, and central regions are most important for the high cognitive state. Collectively, this study may provide further evidence for educators to design cognitive-guided instructional activities to enhance learners' HOTS.

Screening potential diagnostic biomarkers for PLA2R‑associated idiopathic membranous nephropathy by WGCNA analysis and LASSO algorithm

Adult nephrotic syndrome is primarily caused by membranous nephropathy (MN), with idiopathic membranous nephropathy (IMN) being a prominent subtype. The onset of phospholipase A2 receptor (PLA2R1)-associated IMN is critically linked to M-type PLA2R1 exposure, yet the mechanism underlying glomerular injury remains unclear. In this study, membranous nephropathy datasets (GSE115857, GSE200828) were retrieved from GEO. Differential gene expression was analyzed using the 'limma' R package. WGCNA filtered PLA2R-related modules and intersected genes. LASSO regression, evaluated by ROC analysis, identified characteristic genes. Binomial logistic regression assessed their association with IMN. Validation was performed in the GSE133288 dataset. IHC and qRT-PCR detected characteristic gene expression in PLA2R-positive patients. This study identified elevated PLA2R expression in IMN patients among 117 DEGs. PPI analysis suggested enrichment in Golgi membranes, co-regulation, and glucocorticoid responsiveness, implicating the PPAR pathway by KEGG. WGCNA revealed a 440-gene brown module associated with IMN-PLA2R, with ECM1, SLC19A2, RASD1, FOSB, KDELR3, ZFP36, and ELF4 highlighted as diagnostic markers by ROC analysis. Clinical validation confirmed ECM1 upregulation increased IMN risk, while upregulation of SLC19A2, ZFP36, RASD1, and FOSB decreased it. ECM1 positively correlated with PLA2R, whereas SLC19A2, ZFP36, and FOSB negatively correlated. IHC analysis demonstrated consistent gene expression patterns in IMN tissues, with podocyte exposure to PLA2R-positive serum reducing viability and increasing apoptosis. Functional studies, prompted by RASD1 downregulation, revealed enhanced cell activity and reduced apoptosis upon RASD1 overexpression compared to the Serum + Ov-NC control. Collectively, this study identified diagnostic markers for PLA2R-related IMN, offering novel therapeutic targets for the treatment of IMN.

Stage-specific modulation of Drosophila gene expression with muscle GAL4 promoters

The bipartite GAL4/UAS system is the most widely used method for targeted gene expression in Drosophila melanogaster and facilitates rapid in vivo genetic experimentation. Defining precise gene expression patterns for tissues and/or cell types under GAL4 control will continue to evolve to suit experimental needs. However, the precise spatial and temporal expression patterns for some commonly used muscle tissue promoters are still unclear. This missing information limits the precise timing of experiments during development. Here, we focus on three muscle-enriched GAL4 drivers (Mef2-GAL4, C57-GAL4 and G7-GAL4) to better inform selection of the most appropriate muscle promoter for experimental needs. Specifically, C57-GAL4 and G7-GAL4 turn on in the first or second instar larval stages, respectively, and can be used to bypass myogenesis for studies of muscle function after development.

Oxidative stress and reactive oxygen species in otorhinolaryngological diseases: insights from pathophysiology to targeted antioxidant therapies

Oxidative stress, characterized by an imbalance between excessive reactive oxygen species (ROS) production and impaired antioxidant defenses, is closely linked to the pathogenesis of various otorhinolaryngological disorders. Mitochondria, as the primary site of cellular energy production, play a crucial role in modulating oxidative stress. Mitochondrial dysfunction exacerbates ROS generation, leading to cellular damage and inflammatory responses. In otorhinolaryngological diseases, oxidative stress is strongly associated with conditions such as hearing loss, allergic rhinitis, and chronic sinusitis, where oxidative damage and tissue inflammation are key pathological features. Recent studies have highlighted the potential of antioxidant therapies to mitigate oxidative stress and restore homeostasis, offering promising avenues for alleviating symptoms in these diseases. However, despite the encouraging results from early-stage research, the clinical efficacy of antioxidant interventions remains to be fully established. This review provides an overview of the role of oxidative stress in otorhinolaryngological diseases and evaluates the therapeutic potential of antioxidant strategies.

Human induced pluripotent stem cell-derived therapies for regeneration after central nervous system injury

In recent years, the progression of stem cell therapies has shown great promise in advancing the nascent field of regenerative medicine. Considering the non-regenerative nature of the mature central nervous system, the concept that "blank" cells could be reprogrammed and functionally integrated into host neural networks remained intriguing. Previous work has also demonstrated the ability of such cells to stimulate intrinsic growth programs in post-mitotic cells, such as neurons. While embryonic stem cells demonstrated great potential in treating central nervous system pathologies, ethical and technical concerns remained. These barriers, along with the clear necessity for this type of treatment, ultimately prompted the advent of induced pluripotent stem cells. The advantage of pluripotent cells in central nervous system regeneration is multifaceted, permitting differentiation into neural stem cells, neural progenitor cells, glia, and various neuronal subpopulations. The precise spatiotemporal application of extrinsic growth factors in vitro, in addition to microenvironmental signaling in vivo, influences the efficiency of this directed differentiation. While the pluri- or multipotency of these cells is appealing, it also poses the risk of unregulated differentiation and teratoma formation. Cells of the neuroectodermal lineage, such as neuronal subpopulations and glia, have been explored with varying degrees of success. Although the risk of cancer or teratoma formation is greatly reduced, each subpopulation varies in effectiveness and is influenced by a myriad of factors, such as the timing of the transplant, pathology type, and the ratio of accompanying progenitor cells. Furthermore, successful transplantation requires innovative approaches to develop delivery vectors that can mitigate cell death and support integration. Lastly, host immune responses to allogeneic grafts must be thoroughly characterized and further developed to reduce the need for immunosuppression. Translation to a clinical setting will involve careful consideration when assessing both physiologic and functional outcomes. This review will highlight both successes and challenges faced when using human induced pluripotent stem cell-derived cell transplantation therapies to promote endogenous regeneration.

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

JOURNAL/nrgr/04.03/01300535-202511000-00033/figure1/v/2024-12-20T164640Z/r/image-tiff In addition to the loss of motor function, ~ 60% of patients develop pain after spinal cord injury. The cellular-molecular mechanisms are not well understood, but the data suggests that plasticity within the rostral, epicenter, and caudal penumbra of the injury site initiates a cellular-molecular interplay that acts as a rewiring mechanism leading to central neuropathic pain. Sprouting can lead to the formation of new connections triggering abnormal sensory transmission. The excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and excitotoxicity. Our previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator tamoxifen. In this study, we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord injury. We hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters, leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant sprouting. Male and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control (placebo). We used von Frey monofilaments and the "up-down method" to evaluate mechanical allodynia. Tamoxifen treatment decreased allodynia only in female rats with spinal cord injury revealing a sex-dependent effect. The expression profile of glutamatergic transporters (excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1) revealed a sexual dimorphism in the rostral, epicenter, and caudal areas of the spinal cord with a pattern of expression primarily on astrocytes. Female rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased excitatory amino acid transporter-2 expression compared with female rodents. Analyses of peptidergic (calcitonin gene-related peptide-α) and non-peptidergic (isolectin B4) fibers outgrowth in the dorsal horn after spinal cord injury showed an increased calcitonin gene-related peptide-α/ isolectin B4 ratio in comparison with sham, suggesting increased receptive fields in the dorsal horn. Although the behavioral assay shows decreased allodynia in tamoxifen-treated female rats, this was not associated with overexpression of glutamate transporters or alterations in the dorsal horn laminae fibers at 28 days post-injury. Our findings provide new evidence of the sexually dimorphic expression of glutamate transporters in the spinal cord. The dimorphic expression revealed in this study provides a therapeutic opportunity for treating chronic pain, an area with a critical need for treatment.

Advances in therapies using mesenchymal stem cells and their exosomes for treatment of peripheral nerve injury: state of the art and future perspectives

"Peripheral nerve injury" refers to damage or trauma affecting nerves outside the brain and spinal cord. Peripheral nerve injury results in movements or sensation impairments, and represents a serious public health problem. Although severed peripheral nerves have been effectively joined and various therapies have been offered, recovery of sensory or motor functions remains limited, and efficacious therapies for complete repair of a nerve injury remain elusive. The emerging field of mesenchymal stem cells and their exosome-based therapies hold promise for enhancing nerve regeneration and function. Mesenchymal stem cells, as large living cells responsive to the environment, secrete various factors and exosomes. The latter are nano-sized extracellular vesicles containing bioactive molecules such as proteins, microRNA, and messenger RNA derived from parent mesenchymal stem cells. Exosomes have pivotal roles in cell-to-cell communication and nervous tissue function, offering solutions to changes associated with cell-based therapies. Despite ongoing investigations, mesenchymal stem cells and mesenchymal stem cell-derived exosome-based therapies are in the exploratory stage. A comprehensive review of the latest preclinical experiments and clinical trials is essential for deep understanding of therapeutic strategies and for facilitating clinical translation. This review initially explores current investigations of mesenchymal stem cells and mesenchymal stem cell-derived exosomes in peripheral nerve injury, exploring the underlying mechanisms. Subsequently, it provides an overview of the current status of mesenchymal stem cell and exosome-based therapies in clinical trials, followed by a comparative analysis of therapies utilizing mesenchymal stem cells and exosomes. Finally, the review addresses the limitations and challenges associated with use of mesenchymal stem cell-derived exosomes, offering potential solutions and guiding future directions.

Understanding the link between type 2 diabetes mellitus and Parkinson's disease: role of brain insulin resistance

Type 2 diabetes mellitus and Parkinson's disease are chronic diseases linked to a growing pandemic that affects older adults and causes significant socio-economic burden. Epidemiological data supporting a close relationship between these two aging-related diseases have resulted in the investigation of shared pathophysiological molecular mechanisms. Impaired insulin signaling in the brain has gained increasing attention during the last decade and has been suggested to contribute to the development of Parkinson's disease through the dysregulation of several pathological processes. The contribution of type 2 diabetes mellitus and insulin resistance in neurodegeneration in Parkinson's disease, with emphasis on brain insulin resistance, is extensively discussed in this article and new therapeutic strategies targeting this pathological link are presented and reviewed.

Induced pluripotent stem cell-related approaches to generate dopaminergic neurons for Parkinson's disease

The progressive loss of dopaminergic neurons in affected patient brains is one of the pathological features of Parkinson's disease, the second most common human neurodegenerative disease. Although the detailed pathogenesis accounting for dopaminergic neuron degeneration in Parkinson's disease is still unclear, the advancement of stem cell approaches has shown promise for Parkinson's disease research and therapy. The induced pluripotent stem cells have been commonly used to generate dopaminergic neurons, which has provided valuable insights to improve our understanding of Parkinson's disease pathogenesis and contributed to anti-Parkinson's disease therapies. The current review discusses the practical approaches and potential applications of induced pluripotent stem cell techniques for generating and differentiating dopaminergic neurons from induced pluripotent stem cells. The benefits of induced pluripotent stem cell-based research are highlighted. Various dopaminergic neuron differentiation protocols from induced pluripotent stem cells are compared. The emerging three-dimension-based brain organoid models compared with conventional two-dimensional cell culture are evaluated. Finally, limitations, challenges, and future directions of induced pluripotent stem cell-based approaches are analyzed and proposed, which will be significant to the future application of induced pluripotent stem cell-related techniques for Parkinson's disease.

The Citron homology domain of MAP4Ks improves outcomes of traumatic brain injury

JOURNAL/nrgr/04.03/01300535-202511000-00027/figure1/v/2024-12-20T164640Z/r/image-tiff The mitogen-activated protein kinase kinase kinase kinases (MAP4Ks) signaling pathway plays a pivotal role in axonal regrowth and neuronal degeneration following insults. Whether targeting this pathway is beneficial to brain injury remains unclear. In this study, we showed that adeno-associated virus-delivery of the Citron homology domain of MAP4Ks effectively reduces traumatic brain injury-induced reactive gliosis, tauopathy, lesion size, and behavioral deficits. Pharmacological inhibition of MAP4Ks replicated the ameliorative effects observed with expression of the Citron homology domain. Mechanistically, the Citron homology domain acted as a dominant-negative mutant, impeding MAP4K-mediated phosphorylation of the dishevelled proteins and thereby controlling the Wnt/β-catenin pathway. These findings implicate a therapeutic potential of targeting MAP4Ks to alleviate the detrimental effects of traumatic brain injury.

Oligodendroglial heterogeneity in health, disease, and recovery: deeper insights into myelin dynamics

Decades of research asserted that the oligodendroglial lineage comprises two cell types: oligodendrocyte precursor cells and oligodendrocytes. However, recent studies employing single-cell RNA sequencing techniques have uncovered novel cell states, prompting a revision of the existing terminology. Going forward, the oligodendroglial lineage should be delineated into five distinct cell states: oligodendrocyte precursor cells, committed oligodendrocyte precursor cells, newly formed oligodendrocytes, myelin-forming oligodendrocytes, and mature oligodendrocytes. This new classification system enables a deeper understanding of the oligodendroglia in both physiological and pathological contexts. Adopting this uniform terminology will facilitate comparison and integration of data across studies. This, including the consolidation of findings from various demyelinating models, is essential to better understand the pathogenesis of demyelinating diseases. Additionally, comparing injury models across species with varying regenerative capacities can provide insights that may lead to new therapeutic strategies to overcome remyelination failure. Thus, by standardizing terminology and synthesizing data from diverse studies across different animal models, we can enhance our understanding of myelin pathology in central nervous system disorders such as multiple sclerosis, Alzheimer's disease, and amyotrophic lateral sclerosis, all of which involve oligodendroglial and myelin dysfunction.