Blood diagnostic and prognostic biomarkers in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a devastating neurodegenerative disease for which the current treatment approaches remain severely limited. The principal pathological alterations of the disease include the selective degeneration of motor neurons in the brain, brainstem, and spinal cord, as well as abnormal protein deposition in the cytoplasm of neurons and glial cells. The biological markers under extensive scrutiny are predominantly located in the cerebrospinal fluid, blood, and even urine. Among these biomarkers, neurofilament proteins and glial fibrillary acidic protein most accurately reflect the pathologic changes in the central nervous system, while creatinine and creatine kinase mainly indicate pathological alterations in the peripheral nerves and muscles. Neurofilament light chain levels serve as an indicator of neuronal axonal injury that remain stable throughout disease progression and are a promising diagnostic and prognostic biomarker with high specificity and sensitivity. However, there are challenges in using neurofilament light chain to differentiate amyotrophic lateral sclerosis from other central nervous system diseases with axonal injury. Glial fibrillary acidic protein predominantly reflects the degree of neuronal demyelination and is linked to non-motor symptoms of amyotrophic lateral sclerosis such as cognitive impairment, oxygen saturation, and the glomerular filtration rate. TAR DNA-binding protein 43, a pathological protein associated with amyotrophic lateral sclerosis, is emerging as a promising biomarker, particularly with advancements in exosome-related research. Evidence is currently lacking for the value of creatinine and creatine kinase as diagnostic markers; however, they show potential in predicting disease prognosis. Despite the vigorous progress made in the identification of amyotrophic lateral sclerosis biomarkers in recent years, the quest for definitive diagnostic and prognostic biomarkers remains a formidable challenge. This review summarizes the latest research achievements concerning blood biomarkers in amyotrophic lateral sclerosis that can provide a more direct basis for the differential diagnosis and prognostic assessment of the disease beyond a reliance on clinical manifestations and electromyography findings.

Assessment of facial pressure sensitivity of head-mounted displays based on practical application scenarios

With the development of Virtual Reality and Augmented Reality technologies, improving the comfort of head-mounted displays (HMDs) is crucial for optimizing user experience. Although pressure threshold measurements have been widely applied in the design of wearable devices, no studies have yet investigated pressure sensitivity specific to HMDs. This study developed a novel handheld electronic force gauge to measure subjective discomfort sensitivity at nine key contact points between the HMD and the face under varying applied forces. Repeated measures ANOVA was used to compare the results, with discomfort levels classified through clustering. A new sensitivity map was created based on these classifications. The findings show higher pressure sensitivity around the periorbital and zygomatic regions, with gender differences becoming more pronounced as pressure increases. Designers can leverage these data to apply soft or pressure-relieving materials in highly sensitive areas and adjust the weight distribution of the HMD.

ACVR1 drives neuropathic pain by regulating NLRP3-Induced neuronal pyroptosis through the p38 and Smad1/5/8 pathways

BACKGROUND

Neuropathic pain is characterized by sustained pain hypersensitivity caused by nerve injury. The molecular mechanisms underlying this condition remain poorly understood. This study aims to elucidate the role of ACVR1 and its downstream pathways in mediating neuropathic pain through neuronal pyroptosis and neuroinflammation.

METHODS

A spared nerve injury (SNI) model was established both in male and female mouse to induce neuropathic pain. Behavioral tests, Western blot, PCR, and immunofluorescence were used to assess the expression of ACVR1, p-Smad1/5/8, p-p38, and pyroptosis-related proteins (NLRP3, Caspase-1, and GSDMD-N). ACVR1, p38, and Smad1/5/8 were pharmacologically inhibited to evaluate their roles in neuropathic pain and pyroptosis.

RESULTS

Behavioral analysis confirmed successful SNI model establishment, marked by reduced paw withdrawal thresholds (PWT). Protein and mRNA expression analysis revealed significant upregulation of ACVR1, p-Smad1/5/8, and p-p38 in the spinal cord, particularly in neurons. Furthermore, SNI enhanced pyroptosis-related protein expression, including NLRP3, Caspase-1, GSDMD-N, IL-1β and IL-18. Inhibition of ACVR1 alleviated mechanical allodynia, reduced neuronal pyroptosis, and decreased serum IL-1β and IL-18 levels. Similarly, p38 inhibition mitigated NLRP3-induced pyroptosis without altering ACVR1 expression. In contrast, Smad1/5/8 inhibition by DMH-1 effectively reduced pyroptosis and inflammation via NLRP3 but had no effect on p38 phosphorylation. Combined p38 and Smad1/5/8 pathway inhibition synergistically decreased pyroptosis-related protein expression, highlighting their interactive roles in ACVR1-mediated neuropathic pain.

CONCLUSION

These findings suggest that ACVR1 exacerbates neuropathic pain by activating neuronal pyroptosis and neuroinflammation via the p38 and Smad1/5/8 pathways. Targeting ACVR1 and its downstream signaling pathways may offer novel therapeutic strategies for neuropathic pain.

Targeting mitochondria-regulated ferroptosis: A new frontier in Parkinson's disease therapy

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantial nigra. Mitochondrial dysfunction and mitochondrial oxidative stress are central to the pathogenesis of PD, with recent evidence highlighting the role of ferroptosis - a type of regulated cell death dependent on iron metabolism and lipid peroxidation. Mitochondria, the central organelles for cellular energy metabolism, play a pivotal role in PD pathogenesis through the production of Reactive oxygen species (ROS) and the disruption of iron homeostasis. This review explores the intricate interplay between mitochondrial dysfunction and ferroptosis in PD, focusing on key processes such as impaired electron transport chain function, tricarboxylic acid (TCA) cycle dysregulation, disruption of iron metabolism, and altered lipid peroxidation. We discuss key pathways, including the role of glutathione (GSH), mitochondrial ferritin, and the regulation of the mitochondrial labile iron pool (mLIP), which collectively influence the susceptibility of neurons to ferroptosis. Furthermore, this review emphasizes the importance of mitochondrial quality control mechanisms, such as mitophagy and mitochondrial biogenesis, in mitigating ferroptosis-induced neuronal death. Understanding these mechanisms linking the interplay between mitochondrial dysfunction and ferroptosis may pave the way for novel therapeutic approaches aimed at preserving mitochondrial integrity and preventing neuronal loss in PD.

Activation of Epac2 improves Aβ-induced impairment of memory retrieval in an acute model of Alzheimer's disease

Impaired memory retrieval is one of the cognitive markers in the early stage of Alzheimer's Disease (AD). Previous studies report that exchange protein directly activated by cAMP 2 (Epac2) plays a specific and time-limited role in promoting memory retrieval. In this study, we investigated the effect of a novel Epac2 activator, S220, on neuronal and synaptic activities, and memory impairment in an acute AD mouse model. S220 treatment increased the firing rate of action potential and intracellular calcium in primary neuronal cultures. Moreover, S220 treatment increased synaptic currents in CA1 neurons. In the acute AD mouse model, intrahippocampal injection of amyloid-β (Aβ) oligomers impaired memory performance. Notably, administering S220 20 min before retention of contextual fear conditioning recovered the Aβ-induced memory impairment, suggesting an enhancing effect on memory retrieval. Collectively, our data demonstrate that the novel Epac2 activator S220 promotes synaptic communication and neuronal firing, and thereby improves Aβ-induced memory impairment via enhancing memory retrieval, indicating the role of Epac2 as a potential treatment target for AD.

Liquid-to-gel transitions of phase-separated coacervate microdroplets enabled by endogenous enzymatic catalysis

Biomolecular condensates formed by liquid-liquid phase separation (LLPS) play a crucial role in organizing biochemical processes within living cells. The phase transition of these condensates from a functional liquid-like state to a pathological gel-like or solid-like state is believed to be linked to cellular dysfunction and various diseases. Here, we present a biomimetic model to demonstrate that endogenous enzyme-catalyzed crosslinking within condensate-mimicked coacervate microdroplets can promote a liquid-to-gel phase transition. We identify the transformation in physical characteristics of the densely packed microdroplets including reduced internal mobility, increased storage modulus, selective blocking of large nanoparticles, and enhanced salt resistance. The reversible dynamics of gel-like microdroplets mediated by ionic strength exhibited a limited release and recapture of sequestered positively charged guest molecules. Furthermore, we validate that the phase transition contributes to a restricted biochemical process through an enzymatic cascade. Overall, this work represents an adaptive in vitro platform for exploring the phase transitions associated with the physiological functions of biomolecular condensates and offers chemical insights and perspectives for investigating potential mechanisms involved in phase transitions.

The impact of membrane receptors on modulating empathic pain

Humans can estimate each other's pain and provide adapted care to reduce it. Empathetic skills are crucial for caregivers involved in pain management; consequently, educational programs and theories have emphasized the positive role of empathy in reducing pain intensity. It is also widely assumed that if caregivers lack empathy, they will underestimate pain intensity in their patients, and this unempathetic attitude can negatively influence pain intensity perception. Empathy for pain is thought to activate the affective‒motivational components of the pain matrix, which includes the anterior insula, middle and anterior cingulate cortices and amygdala, as indicated by functional magnetic resonance imaging and other methodologies. Activity in this core neural network reflects the affective experience that activates our responses to pain and lays the neural foundation for our understanding of our own emotions and those of others. Additionally, a variety of factors can regulate the intensity of empathy for pain, such as oxytocin and vasopressin receptors. Therefore, we selectively review the molecular mechanisms by which membrane receptors modulate this pain modality.

Genetic inactivation of the CRF2 receptor eliminates morphine-induced sociability deficits in female mice

Social behavior deficits, such as poor sociability and social isolation, are key clinical features of substance use disorders. The corticotropin-releasing factor (CRF) system may underlie the effects of substances of abuse but its implication in substance-induced social behavior deficits remains largely unknown. CRF signaling is mediated by two receptor types, termed CRF1 and CRF2. Using the genetic mouse model of CRF2 receptor-deficiency and the three-chamber task for sociability, the present studies examined the specific role for the CRF2 receptor in sociability deficits induced by morphine. Notably, to assess possible sex-linked differences, female and male CRF2 receptor wild-type (CRF2 WT) or knockout (CRF2 KO) mice were used. Intraperitoneal administration of morphine (1 mg/kg) reliably eliminated the preference for an unfamiliar same-sex conspecific over an object in female CRF2 WT, but not in CRF2 KO, mice, revealing a key role for the CRF2 receptor in opiate-induced sociability deficits. In contrast, morphine almost significantly and similarly reduced the preference for an unfamiliar same-sex conspecific over an object in male CRF2 WT and CRF2 KO mice, indicating no role for the CRF2 receptor. Notably, treatment with morphine never affected distance travelled during the three-chamber test, indicating that CRF2 receptor-dependent or -independent opiate effects were specific to social behavior. The present findings provide initial evidence of a critical sex-linked role for the CRF2 receptor in social behavior deficits induced by opiate substances, suggesting new, sex-customized, therapeutic strategy for opioid use disorders.

Terahertz waves promote Ca2+ transport in the Cav2.1 channel

CaV2.1 channels are the structural foundation for neurotransmitter transmission and other vital biological processes. If autoimmune-mediated reduction in presynaptic CaV2.1 leads to a decrease in calcium influx during a presynaptic action potential, which decreases chemical neurotransmission, leading to a debilitating neuromuscular weakness, also known as Lambert-Eaton myasthenia syndrome. The selectivity filter is a core structural component of CaV2.1 channels, with a pivotal role in regulating the selective permeation of Ca2+ ions. Due to the vibration and rotation frequencies of the selectivity filter of CaV2.1 being located in the terahertz band, terahertz waves at specific frequencies may resonate with it, thereby affecting Ca2+ current passing through CaV2.1. Therefore, it is highly worthwhile to study how the terahertz waves regulate the CaV2.1 channel. In this study, we investigate the structure of CaV2.1 channels using molecular dynamics simulations. The effect of external terahertz waves on the channel has been examined at different resonant frequencies of the selectivity filter. We found that when the frequency of terahertz waves applied is around the symmetrical vibration frequency of the carboxyl group in the selectivity filter, the PMF of CaV2.1 significantly decreases, promoting the transport of Ca2+ ions through CaV2.1. The reason behind this is that the terahertz waves resonate with the carboxyl groups of the selectivity filter, affecting the hydrogen network between the hydrated water of Ca2+ ions and the selectivity filter. These findings open up new treatment avenues for channel diseases such as Lambert-Eaton myasthenic syndrome treated with terahertz waves.

Chronopharmacokinetics of the antidepressant paroxetine: An in vitro and in vivo approach

The circadian rhythm influences homeostatic functions such as sleep, physical activity and food intake as well as pharmacotherapy, namely pharmacokinetics. To investigate the impact of the circadian rhythm on the pharmacokinetics of paroxetine, in vitro synchronized permeability studies were carried out in a tri-culture blood-brain barrier model. Paroxetine demonstrated lower apparent permeability when the cells were incubated at 24 h post-synchronization than at 36 h. Additionally, in vivo chronopharmacokinetic studies were performed in CD-1 female mice administered with paroxetine (5 mg/kg) by intranasal route in the early morning or evening. Paroxetine exposure in the brain was higher when it was administered at the beginning of the active phase (ZT13) compared with the rest phase (ZT1) (p < 0.001), probably owing to the lower levels of P-glycoprotein expressed in the brain at the active phase (p < 0.05). Since melatonin production depends on serotonin, its plasma concentrations were also assessed in vivo. The results demonstrated that melatonin concentrations increased 12 h after paroxetine nasal instillation at ZT13 (p < 0.05), but remained unchanged at ZT1, suggesting that the drug effect is influenced by administration time. In conclusion, the circadian rhythm impacted the pharmacokinetics of paroxetine, especially its distribution into the brain, the target organ. This emphasizes the importance of the time of administration in antidepressant dosing, highlighting its relevance for future studies.

Decoding molecular mechanisms: brain aging and Alzheimer's disease

The complex morphological, anatomical, physiological, and chemical mechanisms within the aging brain have been the hot topic of research for centuries. The aging process alters the brain structure that affects functions and cognitions, but the worsening of such processes contributes to the pathogenesis of neurodegenerative disorders, such as Alzheimer's disease. Beyond these observable, mild morphological shifts, significant functional modifications in neurotransmission and neuronal activity critically influence the aging brain. Understanding these changes is important for maintaining cognitive health, especially given the increasing prevalence of age-related conditions that affect cognition. This review aims to explore the age-induced changes in brain plasticity and molecular processes, differentiating normal aging from the pathogenesis of Alzheimer's disease, thereby providing insights into predicting the risk of dementia, particularly Alzheimer's disease.

In silico discovery of novel compounds for FAK activation using virtual screening, AI-based prediction, and molecular dynamics

Focal Adhesion Kinase (FAK) is a non-receptor tyrosine kinase that plays a crucial role in cell proliferation, migration, and signal transduction. FAK is overexpressed in metastatic and advanced-stage cancers, where it is considered a key kinase in cancer growth and metastasis. However, recent research has revealed that FAK activity decreases in various diseases. we aimed to identify compounds that could enhance FAK activity using structure-based virtual screening and artificial intelligence models from a vast chemical database. We began with an extensive chemical database containing over 10 million compounds and used our newly developed pipeline to screen candidate molecules. To select compounds structurally similar to ZINC40099027 (ZN27), a known FAK activator, we calculated Tanimoto Similarity scores and chose compounds with a score of at least 0.8. Clustering was performed using K-means based on the molecular properties. Subsequently, we utilized docking simulation, deep learning and SAScorer to evaluate and predict the protein-ligand docking affinity and physicochemical properties of the candidate compounds. The deep learning models were selected as state-of-the-art models: GLAM predicts the blood-brain barrier permeability of FAK, and elEmBERT predicts the potential toxicity of compound. The combined results were used to create an evaluation matrix. We selected 10 promising candidate compounds from the initial dataset of 10 million. To evaluate the stability of these top 10 candidate compounds in interaction with the FAK protein, we conducted Molecular Dynamics (MD) simulations. We performed a molecular dynamics simulation for a total of 50 ns and identified the top three promising candidate compounds.

An insect-based bioelectronic sensing system combining flexible dual-sided microelectrode array and insect olfactory circuitry for human lung cancer detection

Early detection of lung cancer significantly enhances treatment outcomes, yet current screening methods are limited by accessibility, sensitivity, and cost. This study introduces a bioelectronic sensing platform that integrates the highly sensitive locust olfactory system with a flexible dual-sided microelectrode array (MEA), for robust, noninvasive, and label-free detection of volatile lung cancer biomarkers. Using an innovative folding-annealing fabrication technique and PEDOT:PSS surface functionalization, we developed flexible, dual-sided MEAs with high electrode densities of 463, 687, and 766 channels/mm2 across prototypes, maintaining low impedance (within 4 × 104 Ω). These MEAs demonstrated mechanical flexibility and stability, enabling direct insertion into locust brain tissue without mechanical reinforcement and facilitating precise recording of neural activity in the antennal lobe triggered by lung cancer-related volatile organic compounds (VOCs) from low concentration (1 ppm). Advanced dimensionality reduction techniques applied to the electrophysiological recordings identified distinct neural response patterns to each VOC biomarker and the complex "scent" emitted from various cell lines. Using high-dimensional population neuronal response analysis with a leave-one-trial-out approach, the platform achieved a 100 % classification success rate for unknown VOCs. Additionally, varying concentrations (ppm-ppb) of individual VOC biomarkers were detected and classified with an accuracy of 86 %. The system was further tested for its ability to detect and classify human lung cancer cell lines based on the unique "scent" of cultured cells, including two non-small cell lung cancer (NSCLC) and two small cell lung cancer (SCLC) types. Quantitative assessments demonstrated that the platform achieved a classification accuracy of 85 % across these cell lines. These results substantiate the platform's potential for enhancing clinical diagnostics through the accurate identification of lung cancer stages and cell types. By integrating biological sensory systems with advanced bioelectronics, this study introduces a novel and efficient approach to lung cancer biomarker detection. It provides a non-invasive, brain-based cancer screening method, offering an accessible and innovative solution for early lung cancer diagnosis.

Behavioral and transcriptomic effects of a novel cannabinoid on a rat valproic acid model of autism

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by impaired social communication, restricted interests, repetitive behavior and irritability. Exposure to valproic acid (VPA) during pregnancy has been shown to increase the risk of autism in children and has led to the development of the in-utero VPA rat model that elicits neurodevelopmental autistic-like features. Offspring exhibit behavioral and neurobiological alterations modelling ASD symptoms. We performed a behavioral and molecular assessment in a rat in-utero VPA model treated with a novel botanical cannabinoid, JZP541. Male offspring from dams treated with VPA were tested acutely and sub-chronically with JZP541 (10, 30, or 100 mg/kg, intraperitoneally). A behavioral testing battery was performed, and brain frontal cortex and hippocampus used for RNA sequencing. In utero exposure to VPA resulted in progeny showing behavioral phenotypes characteristic of ASD. JZP541 attenuated these deficits in social, stereotypic, hyperactivity and irritability behavior in a dose-dependent fashion. VPA exposure was associated with a substantial transcriptional dysregulation impacting multiple key biological processes in a tissue-dependent manner. The expression profiles were integrated with publicly available datasets of autism-associated genes to support the validity of the model used and to focus on the effects of treatment on known autism-relevant transcriptional targets. This approach indicated a strong and dose-dependent reduction of the autism-associated gene expression signature in brain samples from animals dosed with JZP541. Our findings demonstrate JZP541 was able to ameliorate ASD associated behavioral deficits, and this was supported by improvements in putative transcriptional biomarkers of ASD.

Bidirectional regulation of the brain-gut-microbiota axis following traumatic brain injury

JOURNAL/nrgr/04.03/01300535-202508000-00002/figure1/v/2024-09-30T120553Z/r/image-tiff Traumatic brain injury is a prevalent disorder of the central nervous system. In addition to primary brain parenchymal damage, the enduring biological consequences of traumatic brain injury pose long-term risks for patients with traumatic brain injury; however, the underlying pathogenesis remains unclear, and effective intervention methods are lacking. Intestinal dysfunction is a significant consequence of traumatic brain injury. Being the most densely innervated peripheral tissue in the body, the gut possesses multiple pathways for the establishment of a bidirectional "brain-gut axis" with the central nervous system. The gut harbors a vast microbial community, and alterations of the gut niche contribute to the progression of traumatic brain injury and its unfavorable prognosis through neuronal, hormonal, and immune pathways. A comprehensive understanding of microbiota-mediated peripheral neuroimmunomodulation mechanisms is needed to enhance treatment strategies for traumatic brain injury and its associated complications. We comprehensively reviewed alterations in the gut microecological environment following traumatic brain injury, with a specific focus on the complex biological processes of peripheral nerves, immunity, and microbes triggered by traumatic brain injury, encompassing autonomic dysfunction, neuroendocrine disturbances, peripheral immunosuppression, increased intestinal barrier permeability, compromised responses of sensory nerves to microorganisms, and potential effector nuclei in the central nervous system influenced by gut microbiota. Additionally, we reviewed the mechanisms underlying secondary biological injury and the dynamic pathological responses that occur following injury to enhance our current understanding of how peripheral pathways impact the outcome of patients with traumatic brain injury. This review aimed to propose a conceptual model for future risk assessment of central nervous system-related diseases while elucidating novel insights into the bidirectional effects of the "brain-gut-microbiota axis."

Sex-dependent role of the dorsolateral septum in shaping contextual cocaine memory strength

Established memories can be destabilized, updated, and reconsolidated into long-term memory stores. Memory updating and reconsolidation can alter the strength of maladaptive contextual drug memories and consequently context-induced drug craving and relapse. The dorsolateral septum (dlS) is a GABAergic nucleus that receives dense direct input from the cornu ammonis 3 regions of the dorsal hippocampus, a brain region that is critical for the maintenance of contextual cocaine memories. Accordingly, we tested the hypothesis that neuronal activity in the dlS regulates the strength of cocaine-predictive contextual memories prior to reconsolidation. Male and female Sprague-Dawley rats received cocaine self-administration training followed by extinction training in two different environmental contexts. After the last extinction training session, the rats were placed back into the cocaine-predictive context to retrieve and destabilize their cocaine-related contextual memories. Immediately or 6 h after memory retrieval, the rats received intra-dlS vehicle or baclofen/muscimol (B/M; GABAB/A agonists) infusions to inhibit neuronal activity during or after memory updating/reconsolidation, respectively. Resulting changes in cocaine and extinction memory strength were assessed based on the magnitude of unreinforced lever responding in the two contexts. Intra-dlS B/M infusion immediately after memory retrieval increased subsequent context-induced cocaine seeking behaviors in male rats, but not in female rats, whereas delayed B/M treatment had no effects in male rats. Together these findings suggest that the dlS is selectively engaged during memory updating/reconsolidation to reduce the strength of cocaine memories in males, possibly contributing to sex differences in the progression of cocaine use disorder.

Computational insights into the inhibition of cell division in Staphylococcus aureus: Towards novel therapeutics

Staphylococcus aureus, a gram-positive bacterium, causes infective endocarditis, osteoarticular, skin, and respiratory infections. The emergence of multidrug-resistant strains, particularly Methicillin-resistant Staphylococcus aureus (MRSA), has caused a 21-35 % rise in bloodstream infections, complicating treatment strategies. Filamentous temperature-sensitive protein Z (FtsZ), a critical protein involved in bacterial cell division, forms a Z-ring at the division site, making it a key target for novel antibacterial therapies. In this study, 1165 phytochemicals were screened, and three lead molecules namely, Aromadendrin, Leucopelargonidin, and 7-Deacetoxy-7-oxogedunin were identified based on their favorable physicochemical properties, drug-likeness, and estimated binding affinities (- 11.73 kcal/mol, - 10.77 kcal/mol, and - 10.38 kcal/mol, respectively) against FtsZ. 100 ns Molecular dynamics simulations conducted in triplicates confirmed the stability of the FtsZ-ligand complexes.Binding free energy calculations revealed that IMPHY003535 (Leucopelargonidin) exhibited the most favorable binding free energy (-27.25 kcal/mol), followed by 7-Deacetoxy-7-oxogedunin (-15.31 kcal/mol) and Aromadendrin (-13.38 kcal/mol). Leucopelargonidin emerged as the most promising inhibitor, highlighting its potential as a lead compound for developing antibacterial agents targeting FtsZ. These findings demonstrate the significant role of phytochemicals in combating antibiotic resistance and the importance of further optimization, including in vivo studies, to assess their therapeutic potential, which could provide new treatment avenues to overcome bacterial resistance mechanisms.

Diabetic peripheral neuropathy and neuromodulation techniques: a systematic review of progress and prospects

Neuromodulation for diabetic peripheral neuropathy represents a significant area of interest in the management of chronic pain associated with this condition. Diabetic peripheral neuropathy, a common complication of diabetes, is characterized by nerve damage due to high blood sugar levels that lead to symptoms, such as pain, tingling, and numbness, primarily in the hands and feet. The aim of this systematic review was to evaluate the efficacy of neuromodulatory techniques as potential therapeutic interventions for patients with diabetic peripheral neuropathy, while also examining recent developments in this domain. The investigation encompassed an array of neuromodulation methods, including frequency rhythmic electrical modulated systems, dorsal root ganglion stimulation, and spinal cord stimulation. This systematic review suggests that neuromodulatory techniques may be useful in the treatment of diabetic peripheral neuropathy. Understanding the advantages of these treatments will enable physicians and other healthcare providers to offer additional options for patients with symptoms refractory to standard pharmacologic treatments. Through these efforts, we may improve quality of life and increase functional capacity in patients suffering from complications related to diabetic neuropathy.

Wireless, battery-free, remote photoactivation of caged-morphine for photopharmacological pain modulation without side effects

Chronic pain severely impairs physical, psychological, and cognitive functions. While opioid-based therapies can be effective, they are limited by tolerance, dependence, and adverse side effects, highlighting the need for safer alternatives. Recent advances in photopharmacology allow precise modulation of pain-related neuronal circuits, offering improved control and effectiveness. For delivery of light, fully implantable, wireless, battery-free optical systems in miniaturized forms offer attractive options relative to alternatives that use conventional bulk hardware and fiber optic tethers. This work presents a technology of this type, based on microscale light-emitting diodes (μ-ILEDs) and near-field communication (NFC) protocols, and optimized to activate photocaged morphine (pc-Mor) in targeted regions of the spinal cord. The unique flexible, lightweight designs ensure stable, minimally invasive operation in small animal model behavioral studies, with efficient power consumption and minimized thermal load on fragile tissues. Experimental results demonstrate effective pain suppression and reduced opioid-related side effects in an animal model of pain, thereby establishing this platform as a promising solution for chronic pain management.

An in vitro platform for characterizing axonal electrophysiology of individual human iPSC-derived nociceptors

Neuropathic pain is characterized by aberrant activity of specific nociceptor populations, as demonstrated through functional assessments such as microneurography. Current treatments against severe forms of neuropathic pain demonstrate insufficient efficacy or lead to unwanted side effects as they fail to specifically target the affected nociceptors. Tools that can recapitulate aspects of microneurography in vitro would enable a more targeted compound screening. Therefore, we developed an in vitro platform combining a CMOS-based high-density microelectrode array with a polydimethylsiloxane (PDMS) guiding microstructure that captures the electrophysiological responses of individual axons. Human induced pluripotent stem cell-derived (hiPSC) sensory neurons were cultured in a way that allowed axons to be distributed through parallel 4 ×10μm microchannels exiting the seeding well before converging to a bigger axon-collecting channel. This configuration allowed the measurement of stimulation-induced responses of individual axons. Sensory neurons were found to exhibit a great diversity of electrophysiological response profiles that can be classified into different functional archetypes. Moreover, we show that some responses are affected by applying the TRPV1 agonist capsaicin. Overall, results using our platform demonstrate that we were able to distinguish individual axon responses, making the platform a promising tool for testing therapeutic candidates targeting particular sensory neuron subtypes.

Integration of symbolic and non-symbolic numerical information in children: Task dependence and its link to math abilities

From birth, children can access the approximate number system for noisy numerical estimates. With age, they acquire an exact number system for precise numerical information representation. The relations between these two systems and their correlations with math abilities in children remain unclear. In this study, 8- to 10-year-old children (N = 119) completed two tasks to test the integration of symbolic and non-symbolic numerical information (i.e., "symbolic integration") and how this integration relates to children's formal math abilities. For the number comparison task, involving dot arrays and Arabic numerals, children indicated which of two sequentially presented stimuli was larger. These stimuli were either in the same format (dot-dot or numeral-numeral) or in a mixed format (dot-numeral or numeral-dot). For the number-letter discrimination task, participants identified numerals or letter pairs co-occurring with dot arrays that either matched or mismatched the numeral's quantity. In the number comparison task, we found that children were significantly slower when comparing mixed-format stimuli versus same-format conditions, suggesting a lack of symbolic integration (i.e., "symbolic estrangement"). In contrast, in the number-letter discrimination task, children were significantly faster in tasks where the dot arrays and numerals matched, indicating symbolic integration. While we found correlations between number processing and math skills at the condition level for both tasks, neither of the derived measures of symbolic estrangement or symbolic integration correlated with children's performance on a standardized math assessment. Thus, we conclude that numerical integration or estrangement is task dependent and that symbolic integration has limited impact on 8- to 10-year-old children's math abilities.

Kappa opioid receptors diminish spontaneous dopamine signals in awake mice through multiple mechanisms

The role of the dynorphin/kappa opioid receptor (KOR) system in dopamine (DA) regulation has been extensively investigated. KOR activation reduces extracellular DA concentrations, but the exact mechanism(s) through which this is accomplished are not fully elucidated. To explore KOR influences on real-time DA fluctuations, we used the photosensor dLight1.2 with fiber photometry in the nucleus accumbens (NAc) core of freely moving male and female C57BL/6J mice. First, we established that the rise and fall of spontaneously arising DA signals were due to DA release and reuptake, respectively. Next, mice were systemically administered the KOR agonist U50,488H in the presence or absence of the KOR antagonist aticaprant. U50,488H reduced both the amplitude and width of spontaneous signals in both sexes. Further, the slope of the correlation between amplitude and width was increased, indicating that DA uptake rates were increased. U50,488H also reduced the frequency of occurrence of signals in males and females. The effects of KOR activation were stronger in males, while effects of KOR antagonism were stronger in females. Overall, KORs exerted significant inhibitory control over spontaneous DA signaling, acting through at least three mechanisms - inhibiting DA release, promoting DA transporter-mediated uptake, and reducing the frequency of signals.

Kinsenoside attenuates ER stress and inhibits inflammatory responses through IL-10/STAT/SOCS3 pathway in chronic pain relief

Neuro-inflammation contributes to neuropathic pain by sensitizing ionic channels. Kinsenoside, a traditional Chinese medicine, has recognized anti-inflammatory properties. However, it remains unclear whether kinsenoside can be used for pain therapy. Network pharmacology analysis revealed that 57 % of its targets are associated with pain, including inflammation and synaptic transmission. The analgesic effects of kinsenoside were confirmed in SNL and formalin rat models, with ED50 values of 47.99 μg and 36.80 μg, respectively. Transcriptome and WGCNA analyses indicated the involvement of cytokine release, anti-inflammatory activity, and synapse enrichment in the blue module. Furthermore, we confirmed that kinsenoside's efficacy was mainly mediated by IL-10 induction, phosphorylation of STAT3, and SOCS3 expression. Pretreatment with kinsenoside significantly inhibited the release of TNF-α, IL-1β, and IL-6. Kinsenoside also attenuated ER stress in both microglia and neural cells. Molecular docking analysis demonstrated significantly high binding energies of IL-10, STAT3, and SOCS3 with MHC. Additionally, whole-cell recordings revealed that bath application of kinsenoside reduced the frequency and amplitude of spinal glutamatergic transmission in a dose-dependent manner. In summary, pharmacological prediction and biological validation collectively indicate that kinsenoside significantly exerts significant analgesic effects by attenuating ER stress and inhibiting inflammatory responses via the IL-10/p-STAT3/SOCS3 axis, precisely regulating spinal glutamatergic transmission for pain relief.

Connecting the dots: Mitochondrial transfer in immunity, inflammation, and cancer

Mitochondria are more than mere energy generators; they are multifaceted organelles that integrate metabolic, signalling, and immune functions, making them indispensable players in maintaining cellular and systemic health. Mitochondrial transfer has recently garnered attention due to its potential role in several physiological and pathological processes. This process involves multiple mechanisms by which mitochondria, along with mitochondrial DNA and other components, are exchanged between cells. In this review, we examine the critical roles of mitochondrial transfer in health and disease, focusing on its impact on immune cell function, the resolution of inflammation, tissue repair, and regeneration. Additionally, we explore its implications in viral infections and cancer progression. We also provide insights into emerging therapeutic applications, emphasizing its potential to address unmet clinical needs.

Phytocompounds of Senecio candicans as potential acetylcholinesterase inhibitors targeting Alzheimer's disease: A structure-based virtual screening and molecular dynamics simulation study

Alzheimer's disease (AD) is a chronic neurodegenerative disorder characterized by cognitive decline due to the accumulation of amyloid-beta plaques, neurofibrillary tangles, and decreased acetylcholine levels caused by acetylcholinesterase (AChE) activity. Current treatments using synthetic acetylcholinesterase inhibitors (AChEIs) provide only symptomatic relief and are associated with adverse effects, highlighting the need for safer and more effective alternatives. This study investigates the potential of phytoconstituents from the plant Senecio candicans as natural AChE inhibitors for AD treatment. Using structure-based virtual screening, molecular docking, and molecular dynamics simulations, we evaluated several compounds from Senecio candicans for their binding affinity, stability, and inhibitory activity against AChE. The findings identified compounds such as Estra-135(10)-trien-17β-ol and Vulgarone A, which demonstrated strong binding affinities and stable interactions with AChE, comparable to or surpassing the clinically used drug Donepezil. These phytoconstituents exhibited potential as effective AChEIs with potentially fewer side effects. The results underscore the therapeutic potential of plant-based molecules for drug discovery, offering a promising avenue for developing new treatments for neurodegenerative diseases. Combining phytochemical studies with computational methods provides a powerful approach to identifying novel therapeutic agents. This study suggests that phytoconstituents from Senecio candicans could serve as safer alternatives for managing AD. Further experimental validation and clinical studies are necessary to confirm these compounds' efficacy and safety, paving the way for innovative, plant-derived treatments for Alzheimer's disease.

Utilizing engineered extracellular vesicles as delivery vectors in the management of ischemic stroke: a special outlook on mitochondrial delivery

Ischemic stroke is a secondary cause of mortality worldwide, imposing considerable medical and economic burdens on society. Extracellular vesicles, serving as natural nano-carriers for drug delivery, exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke. However, the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency. By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles, their delivery efficacy may be greatly improved. Furthermore, previous studies have indicated that microvesicles, a subset of large-sized extracellular vesicles, can transport mitochondria to neighboring cells, thereby aiding in the restoration of mitochondrial function post-ischemic stroke. Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components, such as proteins or deoxyribonucleic acid, or their sub-components, for extracellular vesicle-based ischemic stroke therapy. In this review, we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies. Given the complex facets of treating ischemic stroke, we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process. Moreover, given the burgeoning interest in mitochondrial delivery, we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.

Mitochondrial translocator-protein ligand etifoxine reduces pain symptoms and protects against motor dysfunction development following peripheral nerve injury in rats

Peripheral nerve injury enhances mitochondrial translocator protein (TSPO) expression in the spinal cord and dorsal root ganglia (DRG), which is associated with neuroinflammation and mitochondrial dysfunction contributing to chronic pain development. Here, we investigate the effect of TSPO ligand Etifoxine, on the development of chronic pain and motor dysfunction following sciatic nerve injury. Mechanical and thermal sensitivity, as well as motor function, were measured in rats before and after sciatic nerve crush (SNC). Rats were treated with the Etifoxine (50 mg/kg, twice daily) for one week. At the end of the experiment, RT-PCR and immunohistochemistry (IHC) were performed to assess mitochondrial stress and neuroinflammation. Additionally, high-resolution respirometry (O2k) was used to evaluate mitochondrial function in the spinal cord following mitochondrial permeability transition pore (mPTP) induction by Ca2+. Etifoxine treatment post-SNC alleviated mechanical and thermal hypersensitivity, as well as motor dysfunction in rats. In addition, Etifoxine treatment modulates neuroinflammation and mitochondrial stress. Specifically, we found a significant reduction in microglia presence and the transcription of pro-inflammatory cytokines (TNFα, IL-6, IL-1β) in the DRG and spinal cord of the SNC/etifoxine-treated group. Furthermore, Etifoxine treatment prevent the decline in mitochondrial respiration, including non-phosphorylation, ATP-linked respiration, and maximal respiration, after mPTP induction by Ca2+. Our findings suggest that TSPO-ligand Etifoxine protects against motor dysfunction and the development of chronic pain by reducing neuroinflammation and apoptosis in the DRG and spinal cord. Importantly, the beneficial effects of TSPO-ligands are reflected in the restoration of the mitochondrial function under challenging conditions.

A novel selective phosphodiesterase 9 inhibitor, irsenontrine (E2027), enhances GluA1 phosphorylation in neurons and improves learning and memory via cyclic GMP elevation

Phosphodiesterase 9 (PDE9) plays a critical role in synaptic plasticity and cognitive function by modulating cyclic GMP (cGMP). Many reports have shown that PDE9 inhibition improves cognitive function and synaptic plasticity in rodents. Several studies have found that the NO/cGMP/PKG pathway is downregulated in patients with Alzheimer's disease (AD) or dementia with Lewy bodies (DLB) and in older individuals. A PDE9 inhibitor could therefore be a potential therapeutic approach for improving cognitive dysfunction in dementia, including in AD and DLB. We previously discovered a novel PDE9 inhibitor, irsenontrine (E2027). In the current study, irsenontrine showed highly selective affinity for PDE9 with more than 1800-fold selectivity over other PDEs. Irsenontrine maleate significantly increased intracellular cGMP levels in rat cortical primary neurons, and phosphorylation of AMPA receptor subunit GluA1 was induced following cGMP elevation. Oral administration of irsenontrine significantly upregulated cGMP levels in the hippocampus and cerebrospinal fluid (CSF) of naïve rats, and a novel object recognition test showed that irsenontrine administration also significantly improved learning and memory. The effects of irsenontrine were confirmed in rats treated with Nω-nitro-l-arginine methyl ester hydrochloride (l-NAME), a model of learning and memory impairment due to downregulation of the cGMP pathway. l-NAME downregulated cGMP in the CSF and hippocampus and impaired novel object recognition, but oral administration of irsenontrine clearly attenuated these phenotypes. These results indicate that irsenontrine improves learning and memory via the elevation of cGMP levels, and they strongly suggest that irsenontrine could be a novel therapeutic approach against cognitive dysfunction.

Challenges and material innovations in drug delivery to central nervous system tumors

Central nervous system (CNS) tumors, encompassing a diverse array of neoplasms in the brain and spinal cord, pose significant therapeutic challenges due to their intricate anatomy and the protective presence of the blood-brain barrier (BBB). The primary treatment obstacle is the effective delivery of therapeutics to the tumor site, which is hindered by multiple physiological, biological, and technical barriers, including the BBB. This comprehensive review highlights recent advancements in material science and nanotechnology aimed at surmounting these delivery challenges, with a focus on the development and application of nanomaterials. Nanomaterials emerge as potent tools in designing innovative drug delivery systems that demonstrate the potential to overcome the limitations posed by CNS tumors. The review delves into various strategies, including the use of lipid nanoparticles, polymeric nanoparticles, and inorganic nanoparticles, all of which are engineered to enhance drug stability, BBB penetration, and targeted tumor delivery. Additionally, this review highlights the burgeoning role of theranostic nanoparticles, integrating therapeutic and diagnostic functionalities to optimize treatment efficacy. The exploration extends to biocompatible materials like biodegradable polymers, liposomes, and advanced material-integrated delivery systems such as implantable drug-eluting devices and microfabricated devices. Despite promising preclinical results, the translation of these material-based strategies into clinical practice necessitates further research and optimization.

Glycolytic dysregulation in Alzheimer's disease: unveiling new avenues for understanding pathogenesis and improving therapy

Alzheimer's disease poses a significant global health challenge owing to the progressive cognitive decline of patients and absence of curative treatments. The current therapeutic strategies, primarily based on cholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists, offer limited symptomatic relief without halting disease progression, highlighting an urgent need for novel research directions that address the key mechanisms underlying Alzheimer's disease. Recent studies have provided insights into the critical role of glycolysis, a fundamental energy metabolism pathway in the brain, in the pathogenesis of Alzheimer's disease. Alterations in glycolytic processes within neurons and glial cells, including microglia, astrocytes, and oligodendrocytes, have been identified as significant contributors to the pathological landscape of Alzheimer's disease. Glycolytic changes impact neuronal health and function, thus offering promising targets for therapeutic intervention. The purpose of this review is to consolidate current knowledge on the modifications in glycolysis associated with Alzheimer's disease and explore the mechanisms by which these abnormalities contribute to disease onset and progression. Comprehensive focus on the pathways through which glycolytic dysfunction influences Alzheimer's disease pathology should provide insights into potential therapeutic targets and strategies that pave the way for groundbreaking treatments, emphasizing the importance of understanding metabolic processes in the quest for clarification and management of Alzheimer's disease.

Activation of transient receptor potential vanilloid 4 impairs long-term depression in nucleus accumbens and induces depressive-like behavior

Long-term depression (LTD), a form of synaptic plasticity, is impaired in the nucleus accumbens (NAc) in depression. While TRPV4 activation regulates synaptic transmission in the hippocampus, its effects in the NAc remain unclear. Here, we examined the effects of TRPV4 activation on LTD induction in the NAc and depressive-like behavior. Mice that were administered the TRPV4 agonist GSK1016790A into the NAc (GSK-mice) showed depressive-like behavior and impaired LTD induction in NAc slices. Additionally, the mRNA and protein levels of dopamine D2 receptor (D2R) and A-type gamma-aminobutyric acid receptor (GABAAR) were markedly decreased in the NAc of GSK-mice. Meanwhile, administering a D2R (quinpirole) or GABAAR (muscimol) agonist reversed LTD impairment in the NAc. The protein levels of phosphorylated protein kinase C (p-PKC) increased markedly and that of phosphorylated protein kinase B (p-Akt) decreased in the NAc of GSK mice. Administration of a PKC antagonist (GF109203X) or phosphatidylinositol 3-kinase (PI3K) agonist (740 Y-P) significantly increased GABAAR protein levels and restored LTD induction in the NAc of GSK-mice. Administration of quinpirole increased p-Akt and GABAAR protein levels in the NAc of GSK-mice. Finally, administration of quinpirole, muscimol, GF109203X or 740 Y-P improved the depressive-like behavior in GSK-mice. This study suggests that activation of TRPV4 impairs LTD induction in the NAc and induces depressive-like behavior, which is likely mediated by down-regulating D2R to inhibit PI3K-Akt pathway, and activating PKC to decrease the expression of GABAAR.

Sharpening the number sense: Developmental trends in numerosity perception

Numerosity perception, the ability to process and estimate the number of objects in a set without explicitly counting, has been widely studied, and one well-established finding is that children become more accurate at perceiving numerosity with age. The question remains, however, what the underlying cognitive processes and mechanisms are that drive this improvement. Some authors have suggested that this is due to an increased numerical precision (i.e., the sharpening hypothesis), whereas others have proposed that the more accurate performance is due to the improved ability to inhibit non-numerical features of the display such as object size and spacing of items (i.e., the filtering hypothesis). The current study examined the developmental trajectory of numerosity perception across three age groups (M = 5.65, M = 11.03, and M = 20.10 years). As expected, more accurate performance was observed with age. Regression and analyses of variance revealing the contribution of numerical and non-numerical predictors in performance show that the performance in all age groups was primarily driven by numerical information and that its contribution increased with age. In addition, a consistent bias toward non-numerical features was observed in all age groups. These results support the sharpening hypothesis for children from 5 years of age to early adulthood, suggesting that from this age onward children increasingly focus on numerical information as they get older. These results have important implications for the understanding of the development and specific improvements of numerical perception.

Soluble tau aggregates decrease the threshold for thalamic oscillations and increase the excitability of thalamic neurons

Sleep disturbances frequently occur early in dementias such as Alzheimer's disease (AD) and potentially arise from many factors including cortico-thalamo-cortical (CTC) loop dysfunction. It has been reported that tau filament deposition occurs in the thalamus and there is thalamic atrophy in symptomatic AD patients which could contribute to CTC loop disturbance. Here we have investigated whether human recombinant tau soluble aggregates can induce dysfunction in thalamic circuits. Electrophysiological measurements were made from acutely isolated male and female rat corticothalamic slices following incubation with tau aggregates. Tau aggregates markedly reduced the threshold for inducing spindle-like oscillations and increased the excitability of thalamic neurons. Tau aggregates also significantly enhanced the frequency of miniature excitatory postsynaptic currents recorded in ventrobasal thalamic neurons, suggesting possible changes in terminal Ca2+ influx. These pro-excitatory effects of tau aggregates could contribute to the aberrant CTC loop dysfunction observed in AD models and patients, which manifests as sleep disturbances and absence seizures.

Chronic social stress induces generalized hyper-sensitivity to aversion: A mouse model with translational validity for understanding and treating negative valence disorders

The RDoC framework focuses on neurobehavioral processes often dysfunctional in mental disorders and commensurate with translational research. Generalized hyper-sensitivity to aversion/threat is common in various stress-related emotional disorders; increased Pavlovian aversion learning-memory (PAL, PAM) provides a translational paradigm for its study. Here we present the development and application of a mouse model for the study of generalized hyper-sensitivity to aversion/threat. In male adult mice, chronic exposure to social aversion (chronic social stress, CSS) leads, relative to controls (CON), to increased acquisition and expression of tone-footshock conditioned freezing behavior. The altered neurobehavioral state of CSS mice is expected to involve structure-function changes in amygdala: in CSS mice, higher levels of both PAL and PAM freezing behavior co-occurred with fewer lateral/basal amygdala glutamate neurons expressing the immediate early-gene protein c-Fos. A current antidepressant, SSRI escitalopram, reversed excessive PAM freezing behavior in CSS mice with sub-chronic dosing. The model was applied to investigate 3 compounds with novel mechanisms of action: indoleamine dioxygenase 1 (IDO 1) inhibition, somatostatin receptor 4 (SSTR4) agonism, and transient receptor potential canonical channels 4 and 5 (TRPC4/5) inhibition. For each, there was evidence for attenuation of excessive PAL and/or PAM in CSS mice. Preclinical validation of TRPC4/5 channels inhibition contributed to the decision to investigate, and accurately predicted, clinical efficacy, measured as reduced amygdala and emotional reactivities to aversion in major depressive disorder. Future work will focus on (back-)translational studies that address stress-induced changes in amygdala reactivity and aversion processing, their underlying etio-pathophysiological causes, and neuropharmacological responsiveness.

Chronic nicotine enhances object recognition memory via inducing long-term potentiation in the medial prefrontal cortex in mice

Chronic nicotine administration enhances cognitive functions, including learning and memory, and ameliorates cognitive impairments observed in psychological and neurodegenerative disorders. However, the detailed mechanisms underlying these effects are not fully understood. In this study, we used a novel object recognition (NOR) test and in vitro slice electrophysiology in mice to investigate the involvement of the medial prefrontal cortex (mPFC), a brain region connected to the hippocampus, and the synaptic plasticity within this region in chronic nicotine-induced object recognition memory enhancement. The NOR test revealed that chronic nicotine administration for five consecutive days significantly enhanced object recognition memory in male and female mice. This effect was blocked by intra-mPFC infusion of mecamylamine (Mec), a non-selective nicotinic acetylcholine receptor (nAChR) antagonist. In parallel with these findings, whole-cell recordings demonstrated that chronic nicotine administration significantly increased the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/N-methyl-d-aspartate (NMDA) ratio in mPFC layer V pyramidal neurons in male but not female mice. This plastic change was suppressed by systemic injection of Mec or methyllycaconitine, an α7 nAChR antagonist. Furthermore, optogenetic erasure of long-term potentiation (LTP) through chromophore-assisted light inactivation of cofilin, a protein essential for stabilizing spine expansion, suppressed chronic nicotine-induced enhancement of recognition memory. These findings suggest that chronic nicotine administration induces LTP in mPFC pyramidal neurons, likely enhancing object recognition memory.

Effects of P301L-TAU on post-translational modifications of microtubules in human iPSC-derived cortical neurons and TAU transgenic mice

JOURNAL/nrgr/04.03/01300535-202508000-00025/figure1/v/2024-09-30T120553Z/r/image-tiff TAU is a microtubule-associated protein that promotes microtubule assembly and stability in the axon. TAU is missorted and aggregated in an array of diseases known as tauopathies. Microtubules are essential for neuronal function and regulated via a complex set of post-translational modifications, changes of which affect microtubule stability and dynamics, microtubule interaction with other proteins and cellular structures, and mediate recruitment of microtubule-severing enzymes. As impairment of microtubule dynamics causes neuronal dysfunction, we hypothesize cognitive impairment in human disease to be impacted by impairment of microtubule dynamics. We therefore aimed to study the effects of a disease-causing mutation of TAU (P301L) on the levels and localization of microtubule post-translational modifications indicative of microtubule stability and dynamics, to assess whether P301L-TAU causes stability-changing modifications to microtubules. To investigate TAU localization, phosphorylation, and effects on tubulin post-translational modifications, we expressed wild-type or P301L-TAU in human MAPT -KO induced pluripotent stem cell-derived neurons (iNeurons) and studied TAU in neurons in the hippocampus of mice transgenic for human P301L-TAU (pR5 mice). Human neurons expressing the longest TAU isoform (2N4R) with the P301L mutation showed increased TAU phosphorylation at the AT8, but not the p-Ser-262 epitope, and increased polyglutamylation and acetylation of microtubules compared with endogenous TAU-expressing neurons. P301L-TAU showed pronounced somatodendritic presence, but also successful axonal enrichment and a similar axodendritic distribution comparable to exogenously expressed 2N4R-wildtype-TAU. P301L-TAU-expressing hippocampal neurons in transgenic mice showed prominent missorting and tauopathy-typical AT8-phosphorylation of TAU and increased polyglutamylation, but reduced acetylation, of microtubules compared with non-transgenic littermates. In sum, P301L-TAU results in changes in microtubule PTMs, suggestive of impairment of microtubule stability. This is accompanied by missorting and aggregation of TAU in mice but not in iNeurons. Microtubule PTMs/impairment may be of key importance in tauopathies.

Square-shaped Cu2MoS4 loaded on three-dimensional flower-like AgBiS2 to form S-scheme heterojunction as a light-driven photoelectrochemical sensor for efficient detection of serotonin in biological samples

Serotonin (5-HT) is a crucial neurotransmitter in the body, with its levels being particularly significant for life safety. Here, we designed the AgBiS2/Cu2MoS4 S-scheme heterojunction by uniformly immobilizing lamellar Cu2MoS4 on the surface of three-dimensional (3D) flower-like AgBiS2 using a simple physical mixing technique. In this case, AgBiS2 and Cu2MoS4 are bonded together by electrostatic attraction to form an active surface with a large specific surface area. Subsequently, the detector 5-HT bound to AgBiS2/Cu2MoS4/GCE undergoes hole oxidation and the photocurrent signal increases significantly. Meanwhile, the reaction mechanism of AgBiS2/Cu2MoS4 composite material was investigated through density functional theory calculations. The AgBiS2/Cu2MoS4/GCE sensor demonstrates a low detection limit of 0.046 nM and a wide linear range (0.0001-8 μM). Furthermore, by comparing UV-Vis spectrophotometry and fluorescence spectroscopy for the detection of 5-HT in human serum, it was proved that the sensor has an impressive recovery rate.

Interaction of major facilitator superfamily domain containing 2A with the blood-brain barrier

The functional and structural integrity of the blood-brain barrier is crucial in maintaining homeostasis in the brain microenvironment; however, the molecular mechanisms underlying the formation and function of the blood-brain barrier remain poorly understood. The major facilitator superfamily domain containing 2A has been identified as a key regulator of blood-brain barrier function. It plays a critical role in promoting and maintaining the formation and functional stability of the blood-brain barrier, in addition to the transport of lipids, such as docosahexaenoic acid, across the blood-brain barrier. Furthermore, an increasing number of studies have suggested that major facilitator superfamily domain containing 2A is involved in the molecular mechanisms of blood-brain barrier dysfunction in a variety of neurological diseases; however, little is known regarding the mechanisms by which major facilitator superfamily domain containing 2A affects the blood-brain barrier. This paper provides a comprehensive and systematic review of the close relationship between major facilitator superfamily domain containing 2A proteins and the blood-brain barrier, including their basic structures and functions, cross-linking between major facilitator superfamily domain containing 2A and the blood-brain barrier, and the in-depth studies on lipid transport and the regulation of blood-brain barrier permeability. This comprehensive systematic review contributes to an in-depth understanding of the important role of major facilitator superfamily domain containing 2A proteins in maintaining the structure and function of the blood-brain barrier and the research progress to date. This will not only help to elucidate the pathogenesis of neurological diseases, improve the accuracy of laboratory diagnosis, and optimize clinical treatment strategies, but it may also play an important role in prognostic monitoring. In addition, the effects of major facilitator superfamily domain containing 2A on blood-brain barrier leakage in various diseases and the research progress on cross-blood-brain barrier drug delivery are summarized. This review may contribute to the development of new approaches for the treatment of neurological diseases.

EZH2-dependent myelination following sciatic nerve injury

JOURNAL/nrgr/04.03/01300535-202508000-00028/figure1/v/2024-09-30T120553Z/r/image-tiff Demyelination and remyelination have been major focal points in the study of peripheral nerve regeneration following peripheral nerve injury. Notably, the gene regulatory network of regenerated myelin differs from that of native myelin. Silencing of enhancer of zeste homolog 2 (EZH2) hinders the differentiation, maturation, and myelination of Schwann cells in vitro. To further determine the role of EZH2 in myelination and recovery post-peripheral nerve injury, conditional knockout mice lacking Ezh2 in Schwann cells (Ezh2fl/fl;Dhh-Cre and Ezh2fl/fl;Mpz-Cre) were generated. Our results show that a significant proportion of axons in the sciatic nerve of Ezh2-depleted mice remain unmyelinated. This highlights the crucial role of Ezh2 in initiating Schwann cell myelination. Furthermore, we observed that 21 days after inducing a sciatic nerve crush injury in these mice, most axons had remyelinated at the injury site in the control nerve, while Ezh2fl/fl;Mpz-Cre mice had significantly fewer remyelinated axons compared with their wild-type littermates. This suggests that the absence of Ezh2 in Schwann cells impairs myelin formation and remyelination. In conclusion, EZH2 has emerged as a pivotal regulatory factor in the process of demyelination and myelin regeneration following peripheral nerve injury. Modulating EZH2 activity during these processes may offer a promising therapeutic target for the treatment of peripheral nerve injuries.

Repeated cocaine exposure and prolonged withdrawal induce spatial memory impairment and dysregulate the glutamatergic synapse composition in the dorsal hippocampus of male rats

Adolescents are particularly susceptible to various forms of gratification, among which psychostimulants. During adolescence the hippocampus, a brain area relevant to spatial memory domain, undergoes maturational processes, such as structural and molecular reorganization of the excitatory synapses. Our goal was to reveal putatively enduring spatial memory deficits and molecular correlates in male rats exposed to repeated cocaine after a period of withdrawal. Towards this goal, adolescent Sprague-Dawley male rats were exposed to chronic cocaine treatment (5 mg/kg/day, subcutaneously) for 15 days and, after 2 weeks of withdrawal, were subjected to spatial order object recognition (SOOR) test, a memory task based on the rat's ability to recognize objects displacement. Next, we investigated subcellular specific expression of markers of the glutamate synapse in the dorsal hippocampus. Our findings show that withdrawal from repeated cocaine exposure during adolescence is associated with spatial memory impairment. Such deficit was correlated to a reduced expression and retention of NMDA receptor subunits, GluN1, GluN2A and GluN2B, at both synaptic and extra-synaptic sites, an effect indicative of impaired NMDA receptor trafficking. Analysis of endocytosis markers (Rab family of monomeric GTPase) revealed that cocaine-withdrawn rats favor the degradative pathway (Rab7-Rab9) over the recycling pathway (Rab11). In contrast, saline-treated rats primarily activate the recycling pathway. Our findings, mislocalization of glutamatergic receptors together with sorting of NMDA receptor towards degradation, rather than recycling, may contribute to the understanding of the mechanisms underlying the spatial memory deficits in male rats with an adolescent history of cocaine.

AAV2-PDE6B restores retinal structure and function in the retinal degeneration 10 mouse model of retinitis pigmentosa by promoting phototransduction and inhibiting apoptosis

JOURNAL/nrgr/04.03/01300535-202508000-00030/figure1/v/2024-09-30T120553Z/r/image-tiff Retinitis pigmentosa is a group of inherited diseases that lead to retinal degeneration and photoreceptor cell death. However, there is no effective treatment for retinitis pigmentosa caused by PDE6B mutation. Adeno-associated virus (AAV)-mediated gene therapy is a promising strategy for treating retinitis pigmentosa. The aim of this study was to explore the molecular mechanisms by which AAV2-PDE6B rescues retinal function. To do this, we injected retinal degeneration 10 (rd10) mice subretinally with AAV2-PDE6B and assessed the therapeutic effects on retinal function and structure using dark- and light-adapted electroretinogram, optical coherence tomography, and immunofluorescence. Data-independent acquisition-mass spectrometry-based proteomic analysis was conducted to investigate protein expression levels and pathway enrichment, and the results from this analysis were verified by real-time polymerase chain reaction and western blotting. AAV2-PDE6B injection significantly upregulated PDE6β expression, preserved electroretinogram responses, and preserved outer nuclear layer thickness in rd10 mice. Differentially expressed proteins between wild-type and rd10 mice were closely related to visual perception, and treating rd10 mice with AAV2-PDE6B restored differentially expressed protein expression to levels similar to those seen in wild-type mice. Kyoto Encyclopedia of Genes and Genome analysis showed that the differentially expressed proteins whose expression was most significantly altered by AAV2-PDE6B injection were enriched in phototransduction pathways. Furthermore, the phototransduction-related proteins Pde6α, Rom1, Rho, Aldh1a1, and Rbp1 exhibited opposite expression patterns in rd10 mice with or without AAV2-PDE6B treatment. Finally, Bax/Bcl-2, p-ERK/ERK, and p-c-Fos/c-Fos expression levels decreased in rd10 mice following AAV2-PDE6B treatment. Our data suggest that AAV2-PDE6B-mediated gene therapy promotes phototransduction and inhibits apoptosis by inhibiting the ERK signaling pathway and upregulating Bcl-2/Bax expression in retinitis pigmentosa.

Aberrant white matter structural connectivity of nucleus accumbens in patients with major depressive disorder: A probabilistic fibre tracing study

BACKGROUND

Extensive neuroimaging studies have established that functional abnormalities and morphological alterations in the nucleus accumbens (NAc) are implicated in major depressive disorder (MDD), but changes in its white matter structural connectivity (SC) remain unclear. We aimed to elucidate the changes in the white matter fibre connectivity of the NAc in MDD patients.

METHODS

This study used probabilistic fibre tracking to analyze the diffusion tensor imaging (DTI) data of 125 MDD patients and 129 healthy controls (HCs), calculating the strength of SC (sSC) from bilateral NAc to the entire brain and its correlation with depressive symptoms.

RESULTS

Compared to HCs, MDD exhibited increased sSC between the left NAc (L.NAc) and regions involving the left middle frontal gyrus, bilateral cingulate gyrus (CG), bilateral hippocampus, left caudate, left medial superior occipital gyrus, right globus pallidus, right superior and middle temporal gyrus, right precuneus, right insula, and right posterior parietal thalamus. Enhanced sSC was also observed between the right NAc (R.NAc) and the left temporal lobe, left posterior superior temporal sulcus (pSTS), bilateral lateral occipital cortex, left hippocampus, right putamen and right ventral occipital cortex. The sSC of L.NAc-left CG and R.NAc-left pSTS was positively correlated with HAMD scores in MDD.

CONCLUSIONS

Abnormal white matter connectivity of the NAc primarily affects the cortico-limbic circuit, cortico-basal ganglia circuit, and the temporal-occipital cortical regions in patients with MDD, along with the asymmetrical features of the inter-hemispheric SC related to NAc. These alteration may underlie the dysfunction of reward processing and emotion regulation in MDD.

Paternal ethanol exposure alters offspring motor skills and behavior in a sex-dependent manner and modifies early growth response 1 expression in the medial prefrontal cortex

BACKGROUND

Alcohol consumption is linked to various health issues exerting direct effects on the consumer and indirectly on offspring through both maternal and paternal transmission pathways. Our recent studies highlight the importance of paternal health before conception, showing that male ethanol consumption can alter epigenetic sperm marks and DNA integrity and testicular organization which led to adverse effects on embryonic development and induced alterations in testicular and sperm characteristics in the offspring.

METHODS

Based on these findings, this study explores the effects of paternal ethanol (15 % v/v) consumption for 12 days on motor development in mice offspring. We also analyzed different behavioral parameters and evaluated the expression of immediate early genes from the medial prefrontal cortex in the progeny during adulthood.

RESULTS

Paternal alcohol intake negatively affects the offspring, showing a delay in the acquisition of motor developmental skills at an early age and some modifications of behavior in a sex-dependent manner in adulthood. Furthermore, this consumption shows an increase in the expression of the Early Growth Response 1 gene in both males and females in the medial prefrontal cortex.

LIMITATIONS

In situ expression of the early growth response 1 gene was not measured. Hormonal fluctuations during the estrous cycle of the female offspring were not considered, these changes could interact with the observed outcomes.

CONCLUSIONS

This gene plays a key role in regulating cognition, emotion, and behavior. These findings highlight the importance of considering paternal health and alcohol consumption when assessing the risks to future generations.

Effects of fecal microbiota transplantation from patients with generalized anxiety on anxiety-like behaviors: The role of the gut-microbiota-endocannabinoid-brain Axis

BACKGROUND

Intestinal dysbacteriosis is frequently implicated in generalized anxiety disorder (GAD). However, the molecular mechanisms and functional changes of the gut-brain axis in GAD remain largely unexplored.

METHODS

We investigated anxiety-like behaviors, gut microbiota changes, brain region-specific endocannabinoid (eCB) system alterations, including the expression of cannabinoid type 1 (CB1R), monoacylglycerol lipase (MAGL), and fatty acid amide hydrolase (FAAH) in the hippocampus (Hip), prefrontal cortex (PFC), and amygdala (Amy), as well as plasma medium- and long-chain fatty acids (MLCFAs) in a mouse model of chronic restraint stress (CRS) and antibiotic-treated mice receiving fecal microbiota transplantation from GAD patients (FMT-GAD). Additionally, we assessed the impact of FMT-GAD on anxiety-like behavior in systemic CB1R/FAAH/MAGL knockout mice.

RESULTS

CRS induced anxiety-like behaviors, suppressed eCB signaling in the brain, and altered the gut microbiota and plasma MLCFA composition in mice. FMT-GAD-treated mice exhibited anxiety-like behaviors, increased FAAH expression in the Hip and Amy, and MAGL expression in the Hip, while reducing CB1R expression in the Hip. FMT-GAD was associated with decreased plasma polyunsaturated fatty acids (PUFAs) and reduced microbiome function for fatty acid biosynthesis. Notably, FMT-GAD intensified anxiety-like behaviors in CB1R-KO mice but failed to induce anxiety-like behaviors in MAGL-KO and FAAH-KO mice.

CONCLUSIONS

This study demonstrates that the interplay between the gut microbiota and the eCB system modulates GAD-related anxiety-like behaviors.

Association between ketogenic diets and depression: A cross-sectional analysis of the NHANES 2005-2023 August

BACKGROUND

The ketogenic diet (KD) is widely used for epilepsy and neurodegenerative diseases. Glutamate, the excitatory neurotransmitter in the body, has been found to be significantly elevated in the brains of some patients with depression. Ketone bodies, the main products of KD, may negatively regulate the metabolic activity of glutamate, which suggests a potential role in the onset and progression of depression. However, the relationship between KD and depression risk remains uncertain.

METHODS

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and August 2023 to investigate the association between the ketogenic diet ratio (KDR) and depression risk. Multiple logistic regression analysis was employed to examine this association, whereas nonlinear relationships were assessed using restricted cubic splines. Stratification analysis was employed to examine the association between KDR and depression severity. Subgroup analyses were also performed.

RESULTS

In a fully adjusted model accounting for confounding variables, KDR was significantly associated with depression risk. Two-piecewise linear regression analysis better fitted the association (KDR < 0.35, OR: 0.11; 95%CI: 0.03-0.35; P < 0.001). Subgroup analyses indicated that this association between KDR and depression was particularly pronounced in certain specific populations. We further observed a significant correlation between KDR and depression severity (P < 0.001).

CONCLUSION

Higher KDR was associated with a reduced risk of depression, with potentially greater efficacy observed in specific populations. Additionally, KDR has been found to be significantly associated with the severity of depression. Further study could investigate their potential mechanism.

Functional COPA is indispensable for early embryo development beyond major genome activation in bovines

Embryonic genome activation is divided into a minor and a major wave of transition to endogenous transcription. In bovines, minor genome activation begins early in the 2-cell stage and is completed by the 8-cell stage when major genome activation becomes dominant. While the activation of genes known to regulate early development have been studied extensively, genes involved in more central cellular functions have not been examined. Taking advantage of the CRISPR Cas9 system, the present study investigated the effect of knocking out the Golgi retrograde protein transporter COPA on early bovine development. After the electroporation of presumptive zygotes with Cas9 ribonucleoproteins targeting COPA exon 6, sequences of 2 (11 %) and 4-cell (16 %) embryos showed knockouts of COPA whereas 8-cell embryos and blastocysts did not, demonstrating that COPA is necessary for development to the 8-cell stage and beyond. Using a repair template containing silent mutations along the target site, COPA loss of wildtype was observed in 5 blastocysts, with successful knock-in of the template on at least one allele. This shows that an edited yet functional copy of COPA can save the developmental capacity of the embryo and demonstrates that Cas9 activity at the target region itself is not responsible for the loss of function. Together, the present study revealed that COPA is necessary for embryonic development, and that the timing of this necessity is before major genome activation onset. More generally, this study further demonstrates the utility of genome editing within reproductive biotechnology for the interrogation of gene function and early embryonic development.

Gut-brain axis modulation by sudachi peel extract enhances resilience to chronic social defeat stress in mice

BACKGROUND

Sudachitin, an anti-inflammatory compound from Citrus sudachi peel, may influence stress resilience. We examined whether sudachi peel extract affects depression-like behaviors and gut microbiota dysbiosis in mice subjected to chronic social defeat stress (CSDS).

METHODS

First, we examined the effect of sudachitin on depression-like behavior and plasma interleukin-6 (IL-6) levels following lipopolysaccharide (LPS, 0.5 mg/kg) administration. Next, we investigated whether supplementation with sudachi peel extract could modulate the gut microbiota dysbiosis induced by CSDS.

RESULTS

Sudachitin prevented LPS-induced depression-like behavior and the rise in plasma IL-6. In control mice, CSDS increased IL-6, induced splenomegaly, and caused anhedonia-like behavior. These changes were absent in the sudachi peel extract group. Although alpha-diversity of the gut microbiota remained abnormal under CSDS, beta-diversity was significantly altered by sudachi peel extract. Moreover, plasma IL-6 levels and Iba1 expression in the prefrontal cortex correlated with the relative abundance of certain gut bacteria.

LIMITATIONS

The exact mechanisms behind the resilience-promoting effects of sudachi peel extract remain unclear.

CONCLUSION

Sudachi peel extract supplementation enhances resilience to CSDS by preventing anhedonia, reducing plasma IL-6 levels and splenomegaly, and modulating gut microbiota composition. Further research is needed to clarify these anti-inflammatory pathways and the roles of additional pro-inflammatory cytokines.

The abnormal choline to creatine ratio of the right anterior cingulate gyrus is linked to cognitive impairment in youth with major depressive disorder

BACKGROUND

Previous studies indicated that the notion that 20-40 % of patients with major depressive disorder (MDD) have cognitive impairments (CI). The mechanism of cognitive deficits in MDD is largely unknown. Recent evidence suggests that metabolic changes may be associated with poorer cognitive outcomes in MDD.

METHOD

We recruited 105 right-handed, untreated youth with MDD patients, and 68 demographically matched healthy controls (HCs), and underwent the MATRICS Consensus Cognitive Battery (MCCB) assessment and proton magnetic resonance spectroscopy (1H-MRS) scan in the anterior cingulate gyrus (ACC) and putamen. Differential and association analysis was performed to investigate the relationship between cognitive performance and neurometabolism ratios of ACC and putamen in MDD groups.

RESULTS

Thirty-nine patients defined as CI group (>1.5 SD below the normal mean of MCCB in two or more MCCB domains) and 67 patients for NCI (without CI) group. The CI group exhibited significantly higher Cho/Cr ratios in the right ACC when compared to the NCI group and HCs groups. Both CI and NCI groups showed significantly higher Cho/Cr ratios in the left putamen compared to the HCs. Meanwhile, the number of episodes were positively correlated with the Cho/Cr ratios in the left putamen (r = 0.35, p = 0.035) in CI group.

CONCLUSION

Our findings suggest that both CI and NCI MDD may experience putamen dysfunction. Additionally, the frequency of depressive episodes appears to have a cumulative effect on alterations in the Cho/Cr ratios in the putamen. Concurrently, an increased Cho/Cr ratio in the ACC is linked to widespread cognitive deficits in MDD patients. These results may point to a subgroup of patients who could benefit from interventions aimed at modulating brain functional status.