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.

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.

Repeated presentation of visual threats drives innate fear habituation and is modulated by threat history and acute stress exposure

To survive predation, animals must be able to detect and appropriately respond to predator threats in their environment. Such defensive behaviors are thought to utilize hard-wired neural circuits for threat detection, sensorimotor integration, and execution of ethologically-relevant behaviors. Despite being hard-wired, defensive behaviors (i.e. fear responses) are not fixed, but rather show remarkable flexibility, suggesting that extrinsic factors such as threat history, environmental contexts, and physiological state may alter innate defensive behavioral responses. The goal of the present study was to examine how extrinsic and intrinsic factors influence innate defensive behaviors in response to visual threats. In the absence of a protective shelter, our results indicate that mice showed robust freezing behavior following both looming (proximal) and sweeping (distal) threats, with increased behavioral vigor in response to looming stimuli, which represent a higher threat imminence. Repeated presentation of looming or sweeping stimuli at short inter-trial intervals resulted in robust habituation of freezing, which was accelerated at longer inter-trial intervals, regardless of contextual cues. Finally, prior stress history such as acute foot shock further disrupted innate freezing habituation, resulting in a delayed habituation phenotype, consistent with a heightened fear state. Together, our results indicate that extrinsic factors such as threat history, environmental familiarity, and stressors have robust and diverse effects on defensive behaviors, highlighting the behavioral flexibility in how mice respond to predator threats.

25 years of Drosophila "Sleep genes"

The field of Drosophila sleep research, which began 25 years ago, has identified more than 200 genes influencing sleep. In this review, I summarize the foundation of the field and the growing list of genes implicated in sleep regulation. I compare the genetic methods used to identify genes governing sleep and circadian rhythms and the distinct outcomes of screens for genes regulating these two highly related processes. Finally, I discuss the ~ 200 sleep-regulating genes of Drosophila in the context of recent developments in the field and voice reasons for scepticism regarding the relevance of these genes to the homoeostatic regulation of sleep. Finally, I speculate on the future promise of the fly model system for revealing conserved molecular mechanisms of sleep homoeostasis.

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.

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.

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.

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.

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.

Glutamatergic CYLD deletion leads to aberrant excitatory activity in the basolateral amygdala: association with enhanced cued fear expression

JOURNAL/nrgr/04.03/01300535-202511000-00029/figure1/v/2024-12-20T164640Z/r/image-tiff Neuronal activity, synaptic transmission, and molecular changes in the basolateral amygdala play critical roles in fear memory. Cylindromatosis (CYLD) is a deubiquitinase that negatively regulates the nuclear factor kappa-B pathway. CYLD is well studied in non-neuronal cells, yet under-investigated in the brain, where it is highly expressed. Emerging studies have shown involvement of CYLD in the remodeling of glutamatergic synapses, neuroinflammation, fear memory, and anxiety- and autism-like behaviors. However, the precise role of CYLD in glutamatergic neurons is largely unknown. Here, we first proposed involvement of CYLD in cued fear expression. We next constructed transgenic model mice with specific deletion of Cyld from glutamatergic neurons. Our results show that glutamatergic CYLD deficiency exaggerated the expression of cued fear in only male mice. Further, loss of CYLD in glutamatergic neurons resulted in enhanced neuronal activation, impaired excitatory synaptic transmission, and altered levels of glutamate receptors accompanied by over-activation of microglia in the basolateral amygdala of male mice. Altogether, our study suggests a critical role of glutamatergic CYLD in maintaining normal neuronal, synaptic, and microglial activation. This may contribute, at least in part, to cued fear expression.

Copper homeostasis and neurodegenerative diseases

Copper, one of the most prolific transition metals in the body, is required for normal brain physiological activity and allows various functions to work normally through its range of concentrations. Copper homeostasis is meticulously maintained through a complex network of copper-dependent proteins, including copper transporters (CTR1 and CTR2), the two copper ion transporters the Cu -transporting ATPase 1 (ATP7A) and Cu-transporting beta (ATP7B), and the three copper chaperones ATOX1, CCS, and COX17. Disruptions in copper homeostasis can lead to either the deficiency or accumulation of copper in brain tissue. Emerging evidence suggests that abnormal copper metabolism or copper binding to various proteins, including ceruloplasmin and metallothionein, is involved in the pathogenesis of neurodegenerative disorders. However, the exact mechanisms underlying these processes are not known. Copper is a potent oxidant that increases reactive oxygen species production and promotes oxidative stress. Elevated reactive oxygen species levels may further compromise mitochondrial integrity and cause mitochondrial dysfunction. Reactive oxygen species serve as key signaling molecules in copper-induced neuroinflammation, with elevated levels activating several critical inflammatory pathways. Additionally, copper can bind aberrantly to several neuronal proteins, including alpha-synuclein, tau, superoxide dismutase 1, and huntingtin, thereby inducing neurotoxicity and ultimately cell death. This study focuses on the latest literature evaluating the role of copper in neurodegenerative diseases, with a particular focus on copper-containing metalloenzymes and copper-binding proteins in the regulation of copper homeostasis and their involvement in neurodegenerative disease pathogenesis. By synthesizing the current findings on the functions of copper in oxidative stress, neuroinflammation, mitochondrial dysfunction, and protein misfolding, we aim to elucidate the mechanisms by which copper contributes to a wide range of hereditary and neuronal disorders, such as Wilson's disease, Menkes' disease, Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, Huntington's disease, and multiple sclerosis. Potential clinically significant therapeutic targets, including superoxide dismutase 1, D-penicillamine, and 5,7-dichloro-2-[(dimethylamino)methyl]-8-hydroxyquinoline, along with their associated therapeutic agents, are further discussed. Ultimately, we collate evidence that copper homeostasis may function in the underlying etiology of several neurodegenerative diseases and offer novel insights into the potential prevention and treatment of these diseases based on copper homeostasis.

Spatial transcriptomics combined with single-nucleus RNA sequencing reveals glial cell heterogeneity in the human spinal cord

JOURNAL/nrgr/04.03/01300535-202511000-00032/figure1/v/2024-12-20T164640Z/r/image-tiff Glial cells play crucial roles in regulating physiological and pathological functions, including sensation, the response to infection and acute injury, and chronic neurodegenerative disorders. Glial cells include astrocytes, microglia, and oligodendrocytes in the central nervous system, and satellite glial cells and Schwann cells in the peripheral nervous system. Despite the greater understanding of glial cell types and functional heterogeneity achieved through single-cell and single-nucleus RNA sequencing in animal models, few studies have investigated the transcriptomic profiles of glial cells in the human spinal cord. Here, we used high-throughput single-nucleus RNA sequencing and spatial transcriptomics to map the cellular and molecular heterogeneity of astrocytes, microglia, and oligodendrocytes in the human spinal cord. To explore the conservation and divergence across species, we compared these findings with those from mice. In the human spinal cord, astrocytes, microglia, and oligodendrocytes were each divided into six distinct transcriptomic subclusters. In the mouse spinal cord, astrocytes, microglia, and oligodendrocytes were divided into five, four, and five distinct transcriptomic subclusters, respectively. The comparative results revealed substantial heterogeneity in all glial cell types between humans and mice. Additionally, we detected sex differences in gene expression in human spinal cord glial cells. Specifically, in all astrocyte subtypes, the levels of NEAT1 and CHI3L1 were higher in males than in females, whereas the levels of CST3 were lower in males than in females. In all microglial subtypes, all differentially expressed genes were located on the sex chromosomes. In addition to sex-specific gene differences, the levels of MT-ND4 , MT2A , MT-ATP6 , MT-CO3 , MT-ND2 , MT-ND3 , and MT-CO2 in all spinal cord oligodendrocyte subtypes were higher in females than in males. Collectively, the present dataset extensively characterizes glial cell heterogeneity and offers a valuable resource for exploring the cellular basis of spinal cord-related illnesses, including chronic pain, amyotrophic lateral sclerosis, and multiple sclerosis.

A single-cell transcriptomic atlas of sensory-dependent gene expression in developing mouse visual cortex

Sensory experience drives the maturation of neural circuits during postnatal brain development through molecular mechanisms that remain to be fully elucidated. One likely mechanism involves the sensory-dependent expression of genes that encode direct mediators of circuit remodeling within developing cells. To identify potential drivers of sensory-dependent synaptic development, we generated a single-nucleus RNA sequencing dataset describing the transcriptional responses of cells in the mouse visual cortex to sensory deprivation or to stimulation during a developmental window when visual input is necessary for circuit refinement. We sequenced 118,529 nuclei across 16 neuronal and non-neuronal cell types isolated from control, sensory deprived and sensory stimulated mice, identifying 1268 sensory-induced genes within the developing brain. While experience elicited transcriptomic changes in all cell types, excitatory neurons in layer 2/3 exhibited the most robust changes, and the sensory-induced genes in these cells are poised to strengthen synapse-to-nucleus crosstalk and to promote cell type-specific axon guidance pathways. Altogether, we expect this dataset to significantly broaden our understanding of the molecular mechanisms through which sensory experience shapes neural circuit wiring in the developing brain.

A ROS-Responsive nanoparticle for nuclear gene delivery and autophagy restoration in Parkinson's disease therapy

Parkinson's disease (PD) is characterized by the pathological aggregation of α-synuclein (α-syn) and neuroinflammation. Current gene therapies face challenges in nuclear delivery and resolving pre-existing α-syn aggregates. Here, we developed glucose-and trehalose-functionalized carbonized polymer dots (GT-PCDs) loaded with plasmid DNA (pDNA) for targeted gene delivery and autophagy restoration. The GT-PCDs@pDNA nanoparticles exhibit reactive oxygen species (ROS)-responsive behavior, enabling efficient nuclear entry under oxidative stress conditions. Both in vitro and in vivo studies demonstrated that GT-PCDs@pDNA effectively silenced SNCA gene expression, reduced α-syn aggregates, and restored autophagic flux by promoting transcription factor EB (TFEB) nuclear translocation. Moreover, GT-PCDs@pDNA enhanced blood-brain barrier (BBB) permeability via glucose transporter 1 (Glut-1)-mediated transcytosis, significantly improving motor deficits and reducing neuroinflammation in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model. This multifunctional nanocarrier system offers a promising strategy for combined gene therapy and autophagy modulation in neurodegenerative diseases.

Multifunctional albumin-based hydrogel/microglia composites enhancing the therapeutic potential of neonatal microglia in complex spinal cord injuries and sealing dural rupture

Treatment for spinal cord injuries (SCIs) remains largely ineffective, with scar formation and neural degeneration being major barriers to functional recovery. Neonatal microglia have shown potential in reducing scar formation and promoting axonal regrowth. However, cell viability and retention at the injury site are often suboptimal. The hostile post-SCI inflammatory microenvironment leads to poor cell survival and the dural damage that is frequently associated with SCIs results in cell loss. To address these challenges, we have developed an albumin-based hydrogel. This hydrogel creates a favorable microenvironment for the encapsulated cells, mimicking the extracellular matrix and enhancing the viability of the transplanted cells. In vivo studies demonstrate its efficacy in preventing scar formation, promoting axonal regeneration, and sealing the dura. Importantly, this hydrogel leverages albumin, a natural polymer in the body, and is synthesized through a simple process, making it highly feasible for clinical translation. In summary, this albumin hydrogel is a valuable delivery vehicle that enhances the therapeutic potential of neonatal microglia in treating SCIs, particularly those involving dural rupture.

Inhibitory gamma-aminobutyric acidergic neurons in the anterior cingulate cortex participate in the comorbidity of pain and emotion

Pain is often comorbid with emotional disorders such as anxiety and depression. Hyperexcitability of the anterior cingulate cortex has been implicated in pain and pain-related negative emotions that arise from impairments in inhibitory gamma-aminobutyric acid neurotransmission. This review primarily aims to outline the main circuitry (including the input and output connectivity) of the anterior cingulate cortex and classification and functions of different gamma-aminobutyric acidergic neurons; it also describes the neurotransmitters/neuromodulators affecting these neurons, their intercommunication with other neurons, and their importance in mental comorbidities associated with chronic pain disorders. Improving understanding on their role in pain-related mental comorbidities may facilitate the development of more effective treatments for these conditions. However, the mechanisms that regulate gamma-aminobutyric acidergic systems remain elusive. It is also unclear as to whether the mechanisms are presynaptic or postsynaptic. Further exploration of the complexities of this system may reveal new pathways for research and drug development.

Autism spectrum disorder: difficulties in diagnosis and microRNA biomarkers

We performed a PubMed search for microRNAs in autism spectrum disorder that could serve as diagnostic biomarkers in patients and selected 17 articles published from January 2008 to December 2023, of which 4 studies were performed with whole blood, 4 with blood plasma, 5 with blood serum, 1 with serum neural cell adhesion molecule L1-captured extracellular vesicles, 1 with blood cells, and 2 with peripheral blood mononuclear cells. Most of the studies involved children and the study cohorts were largely males. Many of the studies had performed microRNA sequencing or quantitative polymerase chain reaction assays to measure microRNA expression. Only five studies had used real-time polymerase chain reaction assay to validate microRNA expression in autism spectrum disorder subjects compared to controls. The microRNAs that were validated in these studies may be considered as potential candidate biomarkers for autism spectrum disorder and include miR-500a-5p, -197-5p, -424-5p, -664a-3p, -365a-3p, -619-5p, -664a-3p, -3135a, -328-3p, and -500a-5p in blood plasma and miR-151a-3p, -181b-5p, -320a, -328, -433, -489, -572, -663a, -101-3p, -106b-5p, -19b-3p, -195-5p, and -130a-3p in blood serum of children, and miR-15b-5p and -6126 in whole blood of adults. Several important limitations were identified in the studies reviewed, and need to be taken into account in future studies. Further studies are warranted with children and adults having different levels of autism spectrum disorder severity and consideration should be given to using animal models of autism spectrum disorder to investigate the effects of suppressing or overexpressing specific microRNAs as a novel therapy.

Activation of adult endogenous neurogenesis by a hyaluronic acid collagen gel containing basic fibroblast growth factor promotes remodeling and functional recovery of the injured cerebral cortex

JOURNAL/nrgr/04.03/01300535-202510000-00024/figure1/v/2024-11-26T163120Z/r/image-tiff The presence of endogenous neural stem/progenitor cells in the adult mammalian brain suggests that the central nervous system can be repaired and regenerated after injury. However, whether it is possible to stimulate neurogenesis and reconstruct cortical layers II to VI in non-neurogenic regions, such as the cortex, remains unknown. In this study, we implanted a hyaluronic acid collagen gel loaded with basic fibroblast growth factor into the motor cortex immediately following traumatic injury. Our findings reveal that this gel effectively stimulated the proliferation and migration of endogenous neural stem/progenitor cells, as well as their differentiation into mature and functionally integrated neurons. Importantly, these new neurons reconstructed the architecture of cortical layers II to VI, integrated into the existing neural circuitry, and ultimately led to improved brain function. These findings offer novel insight into potential clinical treatments for traumatic cerebral cortex injuries.

Functions of nuclear factor Y in nervous system development, function and health

Nuclear factor Y is a ubiquitous heterotrimeric transcription factor complex conserved across eukaryotes that binds to CCAAT boxes, one of the most common motifs found in gene promoters and enhancers. Over the last 30 years, research has revealed that the nuclear factor Y complex controls many aspects of brain development, including differentiation, axon guidance, homeostasis, disease, and most recently regeneration. However, a complete understanding of transcriptional regulatory networks, including how the nuclear factor Y complex binds to specific CCAAT boxes to perform its function remains elusive. In this review, we explore the nuclear factor Y complex's role and mode of action during brain development, as well as how genomic technologies may expand understanding of this key regulator of gene expression.

Persistent alterations in gray matter in COVID-19 patients experiencing sleep disturbances: a 3-month longitudinal study

JOURNAL/nrgr/04.03/01300535-202510000-00030/figure1/v/2024-11-26T163120Z/r/image-tiff Sleep disturbances are among the most prevalent neuropsychiatric symptoms in individuals who have recovered from severe acute respiratory syndrome coronavirus 2 infections. Previous studies have demonstrated abnormal brain structures in patients with sleep disturbances who have recovered from coronavirus disease 2019 (COVID-19). However, neuroimaging studies on sleep disturbances caused by COVID-19 are scarce, and existing studies have primarily focused on the long-term effects of the virus, with minimal acute phase data. As a result, little is known about the pathophysiology of sleep disturbances in the acute phase of COVID-19. To address this issue, we designed a longitudinal study to investigate whether alterations in brain structure occur during the acute phase of infection, and verified the results using 3-month follow-up data. A total of 26 COVID-19 patients with sleep disturbances (aged 51.5 ± 13.57 years, 8 women and 18 men), 27 COVID-19 patients without sleep disturbances (aged 47.33 ± 15.98 years, 9 women and 18 men), and 31 age- and gender-matched healthy controls (aged 49.19 ± 17.51 years, 9 women and 22 men) were included in this study. Eleven COVID-19 patients with sleep disturbances were included in a longitudinal analysis. We found that COVID-19 patients with sleep disturbances exhibited brain structural changes in almost all brain lobes. The cortical thicknesses of the left pars opercularis and left precuneus were significantly negatively correlated with Pittsburgh Sleep Quality Index scores. Additionally, we observed changes in the volume of the hippocampus and its subfield regions in COVID-19 patients compared with the healthy controls. The 3-month follow-up data revealed indices of altered cerebral structure (cortical thickness, cortical grey matter volume, and cortical surface area) in the frontal-parietal cortex compared with the baseline in COVID-19 patients with sleep disturbances. Our findings indicate that the sleep disturbances patients had altered morphology in the cortical and hippocampal structures during the acute phase of infection and persistent changes in cortical regions at 3 months post-infection. These data improve our understanding of the pathophysiology of sleep disturbances caused by COVID-19.

Recovery of the injured neural system through gene delivery to surviving neurons in Parkinson's disease

A critical unaddressed problem in Parkinson's disease is the lack of therapy that slows or hampers neurodegeneration. While medications effectively manage symptoms, they offer no long-term benefit because they fail to address the underlying neuronal loss. This highlights that the elusive goals of halting progression and restoring damaged neurons limit the long-term impact of current approaches. Recent clinical trials using gene therapy have demonstrated the safety of various vector delivery systems, dosages, and transgenes expressed in the central nervous system, signifying tangible and substantial progress in applying gene therapy as a promising Parkinson's disease treatment. Intriguingly, at diagnosis, many dopamine neurons remain in the substantia nigra, offering a potential window for recovery and survival. We propose that modulating these surviving dopamine neurons and axons in the substantia nigra and striatum using gene therapy offers a potentially more impactful therapeutic approach for future research. Moreover, innovative gene therapies that focus on preserving the remaining elements may have significant potential for enhancing long-term outcomes and the quality of life for patients with Parkinson's disease. In this review, we provide a perspective on how gene therapy can protect vulnerable elements in the substantia nigra and striatum, offering a novel approach to addressing Parkinson's disease at its core.

Reduced mesencephalic astrocyte-derived neurotrophic factor expression by mutant androgen receptor contributes to neurodegeneration in a model of spinal and bulbar muscular atrophy pathology

JOURNAL/nrgr/04.03/01300535-202509000-00027/figure1/v/2024-11-05T132919Z/r/image-tiff Spinal and bulbar muscular atrophy is a neurodegenerative disease caused by extended CAG trinucleotide repeats in the androgen receptor gene, which encodes a ligand-dependent transcription factor. The mutant androgen receptor protein, characterized by polyglutamine expansion, is prone to misfolding and forms aggregates in both the nucleus and cytoplasm in the brain in spinal and bulbar muscular atrophy patients. These aggregates alter protein-protein interactions and compromise transcriptional activity. In this study, we reported that in both cultured N2a cells and mouse brain, mutant androgen receptor with polyglutamine expansion causes reduced expression of mesencephalic astrocyte-derived neurotrophic factor. Overexpression of mesencephalic astrocyte-derived neurotrophic factor ameliorated the neurotoxicity of mutant androgen receptor through the inhibition of mutant androgen receptor aggregation. Conversely, knocking down endogenous mesencephalic astrocyte-derived neurotrophic factor in the mouse brain exacerbated neuronal damage and mutant androgen receptor aggregation. Our findings suggest that inhibition of mesencephalic astrocyte-derived neurotrophic factor expression by mutant androgen receptor is a potential mechanism underlying neurodegeneration in spinal and bulbar muscular atrophy.

Treadmill exercise in combination with acousto-optic and olfactory stimulation improves cognitive function in APP/PS1 mice through the brain-derived neurotrophic factor- and Cygb-associated signaling pathways

JOURNAL/nrgr/04.03/01300535-202509000-00031/figure1/v/2024-11-05T132919Z/r/image-tiff A reduction in adult neurogenesis is associated with behavioral abnormalities in patients with Alzheimer's disease. Consequently, enhancing adult neurogenesis represents a promising therapeutic approach for mitigating disease symptoms and progression. Nonetheless, non-pharmacological interventions aimed at inducing adult neurogenesis are currently limited. Although individual non-pharmacological interventions, such as aerobic exercise, acousto-optic stimulation, and olfactory stimulation, have shown limited capacity to improve neurogenesis and cognitive function in patients with Alzheimer's disease, the therapeutic effect of a strategy that combines these interventions has not been fully explored. In this study, we observed an age-dependent decrease in adult neurogenesis and a concurrent increase in amyloid-beta accumulation in the hippocampus of amyloid precursor protein/presenilin 1 mice aged 2-8 months. Amyloid deposition became evident at 4 months, while neurogenesis declined by 6 months, further deteriorating as the disease progressed. However, following a 4-week multifactor stimulation protocol, which encompassed treadmill running (46 min/d, 10 m/min, 6 days per week), 40 Hz acousto-optic stimulation (1 hour/day, 6 days/week), and olfactory stimulation (1 hour/day, 6 days/week), we found a significant increase in the number of newborn cells (5'-bromo-2'-deoxyuridine-positive cells), immature neurons (doublecortin-positive cells), newborn immature neurons (5'-bromo-2'-deoxyuridine-positive/doublecortin-positive cells), and newborn astrocytes (5'-bromo-2'-deoxyuridine-positive/glial fibrillary acidic protein-positive cells). Additionally, the amyloid-beta load in the hippocampus decreased. These findings suggest that multifactor stimulation can enhance adult hippocampal neurogenesis and mitigate amyloid-beta neuropathology in amyloid precursor protein/presenilin 1 mice. Furthermore, cognitive abilities were improved, and depressive symptoms were alleviated in amyloid precursor protein/presenilin 1 mice following multifactor stimulation, as evidenced by Morris water maze, novel object recognition, forced swimming test, and tail suspension test results. Notably, the efficacy of multifactor stimulation in consolidating immature neurons persisted for at least 2 weeks after treatment cessation. At the molecular level, multifactor stimulation upregulated the expression of neuron-related proteins (NeuN, doublecortin, postsynaptic density protein-95, and synaptophysin), anti-apoptosis-related proteins (Bcl-2 and PARP), and an autophagy-associated protein (LC3B), while decreasing the expression of apoptosis-related proteins (BAX and caspase-9), in the hippocampus of amyloid precursor protein/presenilin 1 mice. These observations might be attributable to both the brain-derived neurotrophic factor-mediated signaling pathway and antioxidant pathways. Furthermore, serum metabolomics analysis indicated that multifactor stimulation regulated differentially expressed metabolites associated with cell apoptosis, oxidative damage, and cognition. Collectively, these findings suggest that multifactor stimulation is a novel non-invasive approach for the prevention and treatment of Alzheimer's disease.

Glucocorticoid receptor signaling in the brain and its involvement in cognitive function

The hypothalamic-pituitary-adrenal axis regulates the secretion of glucocorticoids in response to environmental challenges. In the brain, a nuclear receptor transcription factor, the glucocorticoid receptor, is an important component of the hypothalamic-pituitary-adrenal axis's negative feedback loop and plays a key role in regulating cognitive equilibrium and neuroplasticity. The glucocorticoid receptor influences cognitive processes, including glutamate neurotransmission, calcium signaling, and the activation of brain-derived neurotrophic factor-mediated pathways, through a combination of genomic and non-genomic mechanisms. Protein interactions within the central nervous system can alter the expression and activity of the glucocorticoid receptor, thereby affecting the hypothalamic-pituitary-adrenal axis and stress-related cognitive functions. An appropriate level of glucocorticoid receptor expression can improve cognitive function, while excessive glucocorticoid receptors or long-term exposure to glucocorticoids may lead to cognitive impairment. Patients with cognitive impairment-associated diseases, such as Alzheimer's disease, aging, depression, Parkinson's disease, Huntington's disease, stroke, and addiction, often present with dysregulation of the hypothalamic-pituitary-adrenal axis and glucocorticoid receptor expression. This review provides a comprehensive overview of the functions of the glucocorticoid receptor in the hypothalamic-pituitary-adrenal axis and cognitive activities. It emphasizes that appropriate glucocorticoid receptor signaling facilitates learning and memory, while its dysregulation can lead to cognitive impairment. This provides clues about how glucocorticoid receptor signaling can be targeted to overcome cognitive disability-related disorders.

Targeting harmful effects of non-excitatory amino acids as an alternative therapeutic strategy to reduce ischemic damage

The involvement of the excitatory amino acids glutamate and aspartate in cerebral ischemia and excitotoxicity is well-documented. Nevertheless, the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely understudied. The release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the penumbra. Our findings indicated that the reversible loss of field excitatory postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids (L-alanine, glycine, L-glutamine, and L-serine) at their plasma concentrations. These amino acids induce swelling in the somas of neurons and astrocytes during hypoxia, along with permanent dendritic damage mediated by N-methyl-D-aspartate receptors. Blocking N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during hypoxia. It is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels, leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor activation. Thus, previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain injury. Understanding these pathways could highlight new therapeutic targets to mitigate brain injury.

Crosstalk among canonical Wnt and Hippo pathway members in skeletal muscle and at the neuromuscular junction

Skeletal muscles are essential for locomotion, posture, and metabolic regulation. To understand physiological processes, exercise adaptation, and muscle-related disorders, it is critical to understand the molecular pathways that underlie skeletal muscle function. The process of muscle contraction, orchestrated by a complex interplay of molecular events, is at the core of skeletal muscle function. Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction. Within muscle fibers, calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force. Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling. The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis. Myogenic regulators coordinate the differentiation of myoblasts into mature muscle fibers. Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability. Several muscle-related diseases, including congenital myasthenic disorders, sarcopenia, muscular dystrophies, and metabolic myopathies, are underpinned by dysregulated molecular pathways in skeletal muscle. Therapeutic interventions aimed at preserving muscle mass and function, enhancing regeneration, and improving metabolic health hold promise by targeting specific molecular pathways. Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway, a critical regulator of myogenesis, muscle regeneration, and metabolic function, and the Hippo signaling pathway. In recent years, more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers, and at the neuromuscular junction. In fact, research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers. In this review, we will summarize and discuss the data on these two pathways, focusing on their concerted action next to their contribution to skeletal muscle biology. However, an in-depth discussion of the non-canonical Wnt pathway, the fibro/adipogenic precursors, or the mechanosensory aspects of these pathways is not the focus of this review.

Phase-adapted metal ion supply for spinal cord repair with a Mg-Zn incorporated chimeric microsphere

Dynamic alterations in metal ion concentrations are observed in the pathological process of spinal cord injury (SCI). Hence, strategically supplying metal ions in a phase-adapted manner is promising to facilitate injured spinal cord repair by preventing pathological damage. To achieve this, a chimeric hydrogel microsphere with Mg2+-crosslinked methacrylate gelatin as the "shell" and Zn2+-loaded poly (lactic-co-glycolic acid) (PLGA) as the "core" was designed. The chimeric microspheres allow continuous delivery of Mg2+ or Zn2+ at the exact required phase in SCI pathological process. Early release of Mg2+ reduced inflammation by diminishing the secretion of proinflammatory cytokines due to changes in macrophage polarization, which further suppressed scar formation to create an ideal space for neural regeneration. The subsequently released Zn2+ at the late phase effectively promoted neural cell proliferation and regeneration, which was accompanied by activation of mature neurons, interneurons, and motor neurons, leading to significant behavioral recovery. Thus, this study underscores the critical role of metal ions at different phases of injured spinal cord repair and describes the construction of an injectable chimeric hydrogel microsphere carrying distinct metal ions with a core-shell structure. Chimeric microspheres overcome the discrepancy between the inflammatory response and neural regeneration and are a promising therapeutic strategy for injured spinal cord repair.

Engineering a long-lasting microvasculature in vitro model for traumatic injury research

Microvascular injuries can have systemic physiological effects that exacerbate other injuries and pose a danger to life. Reliable in vitro microvascular models are required to enhance understanding of traumatic injuries. This research aims to develop and optimise a three-dimensional (3D) hydrogel construct for the formation and long-term stability of an in vitro microvascular model for trauma research. First, we develop a 3D hydrogel scaffold using a physiologically relevant cell type to enable the formation of a durable microvascular endothelial network and validate it against the gold standard: HUVECs. Then, we explore the impact of modifying the hydrogel composition, specifically fibrinogen source and concentration, medium, and crosslinking ratio, on scaffold material properties and, consequently, the formation of endothelial networks, their architecture, and long-term integrity. Our results demonstrate that 3D hydrogel scaffolds are crucial for maintaining network stability beyond the initial 24 h. For trauma research applications, the material properties and mechanical behaviour of the hydrogels are critical. Microrheometry revealed that fibrinogen concentration significantly influences gelation times, absorbance rate, storage modulus (G'), loss modulus (G"), and complex viscosity, while also reducing creep compliance. Our multi-pronged approach to engineering microvasculature constructs revealed that variations in hydrogel composition, including fibrinogen concentration and source, crosslinking ratio and choice of medium, strongly affect the hydrogel material characteristics and, in turn, the resulting microvascular networks. Hydrogels made with high concentrations of human fibrinogen, a 200:10:1 crosslinking ratio, and endothelial basal medium (EBM) or EBM supplemented with VEGF performed best, demonstrating superior long-term network stability. The microvasculature construct developed here could be used as a potential platform for studying traumatic injuries, as well as testing interventions aimed at improving recovery and mitigating damage.

Investigation of the relationship between 0.5-1200 Hz signal characteristics of cortical high-frequency oscillations and epileptogenicity through multivariate analysis

Fast ripples (FRs) (250-500 Hz) on the electroencephalogram (EEG) are closely related to epileptogenicity and are important to determine cortical regions resected in epilepsy surgery. However, FR-related epileptogenicity may be variable, and may depend on information associated with FRs. We enrolled nine epilepsy patients who had undergone intracranial 5 kHz-sampling-rate EEG for surgical treatment and had final Engel class I outcomes. Three electrodes were selected from each epileptogenic area (EA) and the unlikely EA (the region outside the EA) in each patient. Up to 100 candidate FRs were automatically detected from interictal nocturnal EEG at each of the selected electrodes and were visually reviewed independently by two researchers. Multivariate logistic regression analysis was performed using the frequency and log-power value of the corresponding FRs, presence of concurrent spike, ripple, very-high-frequency oscillations (vHFO)1 (500-600 Hz), and vHFO2 (600-1200 Hz), and whether the timing of the spectral peak of corresponding FRs was in the peak-trough or trough-peak transition of each slow activity (0.5-1, 1-2, 2-3, 3-4, and 4-8 Hz) as independent variables. Factors significantly related to epileptogenicity were FR power, the concurrent presence of spike and vHFO2, coupling with 0.5-1 and 1-2 Hz slow waves in the peak-trough transition, and coupling with 3-4 and 4-8 Hz slow waves in the trough-peak transition. Multifactorial analysis of FRs may increase their usefulness, potentially leading to improved treatment outcomes in epilepsy surgery.

Olfactory receptors in neural regeneration in the central nervous system

Olfactory receptors are crucial for detecting odors and play a vital role in our sense of smell, influencing behaviors from food choices to emotional memories. These receptors also contribute to our perception of flavor and have potential applications in medical diagnostics and environmental monitoring. The ability of the olfactory system to regenerate its sensory neurons provides a unique model to study neural regeneration, a phenomenon largely absent in the central nervous system. Insights gained from how olfactory neurons continuously replace themselves and reestablish functional connections can provide strategies to promote similar regenerative processes in the central nervous system, where damage often results in permanent deficits. Understanding the molecular and cellular mechanisms underpinning olfactory neuron regeneration could pave the way for developing therapeutic approaches to treat spinal cord injuries and neurodegenerative diseases like Alzheimer's disease. Olfactory receptors are found in almost any cell of every organ/tissue of the mammalian body. This ectopic expression provides insights into the chemical structures that can activate olfactory receptors. In addition to odors, olfactory receptors in ectopic expression may respond to endogenous compounds and molecules produced by mucosal colonizing microbiota. The analysis of the function of olfactory receptors in ectopic expression provides valuable information on the signaling pathway engaged upon receptor activation and the receptor's role in proliferation and cell differentiation mechanisms. This review explores the ectopic expression of olfactory receptors and the role they may play in neural regeneration within the central nervous system, with particular attention to compounds that can activate these receptors to initiate regenerative processes. Evidence suggests that olfactory receptors could serve as potential therapeutic targets for enhancing neural repair and recovery following central nervous system injuries.