Neuroscience Bulletin

Brutons tyrosine kinase (BTK) has been reported to be important in the inflammatory response in many diseases. However, its role and explicit mechanisms in intracerebral hemorrhage (ICH) remain unclear. Here, we used a mouse ICH model and transcriptomic datasets to explore the effect of BTK on neuroinflammation after ICH. Inhibiting BTK with ibrutinib alleviated ICH-induced neurological deficits and neuroinflammation in mice. After analyzing RNA-sequencing data of ICH and control mice by weighted gene co-expression network analysis (WGCNA) and protein-protein interaction (PPI) analysis, we found that Btk was a hub gene in the green dynamic module. Also, 12 hub genes that closely interacted with BTK were identified in the key gene module, all having a critical role in the inflammatory process. Then, single cell RNA-sequencing data analysis showed that microglia were the immune cells that expressed the most BTK in the mouse brain. After dividing microglia in ICH mice into BTK_high and BTK_low groups, GO/KEGG enrichment analyses of differentially expressed genes (DEGs) between these two microglia groups revealed that most of the top 30 enriched pathways were immune-related. Then, gene set enrichment analysis (GSEA) of the BTK_high and BTK_low microglia showed that the expression levels of four anti-inflammatory and phagocytosis-related pathways were significantly lower in the BTK_high microglia than in the BTK_low microglia. Furthermore, gene set variation analysis (GSVA) demonstrated that multiple immune pathways were expressed differentially between the two microglia groups. Also, six microglia polarization scores were calculated, and the results showed that the BTK_high microglia tend to polarize towards M1 and M2b states, while the BTK_high microglia towards M2 (M2a, M2c) states. Finally, intercellular communication analysis was conducted, and BTK was revealed to promote communication between microglia and other immune cells both at the general level and in specific inflammatory pathways. In conclusion, our study showed that BTK is critical in promoting post-ICH neuroinflammation, at least partly by interacting with Btk-related hub genes and modulating microglias immune pathways, polarization, and intercellular communication.

Presenilin 1 (PS1), a key pathogenic factor in familial Alzheimers disease, is implicated in regulation of mitochondrial functions, yet its precise sub-mitochondrial localization and underlying mechanisms remain poorly understood. In this study, we generated PS1 knockout (PS1 KO) cell lines to investigate the role of PS1 in mitochondrial structure and function. Our results demonstrated that PS1 is directly localized to the mitochondrial inner membrane. PS1 deficiency led to reduced ATP production, impaired mitochondrial respiration capacity, decreased mitochondrial membrane potential, disrupted Ca2+ homeostasis, and elevated reactive oxygen species (ROS) accumulation. Moreover, loss of PS1 caused abnormal mitochondrial cristae structure. Further analysis revealed that PS1 interacts with mitochondrial inner membrane proteins. Its absence promotes ATAD3A oligomerization and disrupts its arrangement at mitochondrial cristae junctions, leading to expansion of the mitochondria-associated membrane (MAM) and instability of mitochondrial DNA (mtDNA). Our findings demonstrate that PS1 acts as a central regulator of mitochondrial cristae morphogenesis by modulating protein interaction networks at cristae junctions, thereby illuminating fundamental molecular mechanisms contributing to mitochondrial dysfunctions in Alzheimers disease.

Glioma is the most common primary malignant tumor of the brain, and accumulating evidence indicates that neuronal activity plays a pivotal role in tumor progression. In this study, neuronal activity is modulated in vitro using potassium chloride (KCl)-induced depolarization and midazolam (MDZ)-mediated suppression. MDZ is a neuronal activity modulation medication, commonly used for sedation, anxiolysis, and amnesia in clinics. After treatment, conditioned media derived from these neuronal cultures are subsequently co-cultured with glioma cells. EdU incorporation assays demonstrate that MDZ significantly inhibits glioma cell proliferation in vitro. Furthermore, an orthotopic xenograft glioma model is established to assess the anti-tumor efficacy of MDZ in vivo, as evaluated by tumor volume and Ki-67 immunostaining. Mechanistically, insulin-like growth factor 1 (IGF1) is identified as the neuronal-activity-regulated factor that promotes glioma growth through activation of the PI3K/AKT signaling pathway. Moreover, transcriptomic profiling of brain tissues reveals that MDZ attenuates neuronal activity and downregulates neuron-derived growth factors in both glioma and non-tumor regions, thereby exerting anti-tumor effects in vivo. Collectively, these findings demonstrate that MDZ suppresses glioma progression by suppressing neuronal activity and inhibiting neuron-derived trophic factors, providing new insights into the development of therapeutic strategies for glioma.

Alzheimers disease (AD), the leading cause of dementia, affects over 33 million people worldwide, with pathogenesis tied to amyloid-{beta} (A{beta}) accumulation. Although anti-A{beta} monoclonal antibodies have shown clinical benefits, they often cause side effects including amyloid-related imaging abnormalities and brain microhemorrhage, especially in APOE E4 allele carriers. Here we used PHP.eB serotype adeno-associated virus (AAV), a vector with enhanced central nervous system (CNS) tropism, to deliver an A{beta} antibody expression vector (AAV-LEC) into the CNS of APP/PS1 and 5xFAD mice intravenously. The AAV-LEC-mediated expression of anti-A{beta} antibodies in the CNS significantly reduced the number and size of A{beta} plaques at various stages in both APP/PS1 and 5xFAD mice, alongside improved spatial learning and memory. It also reversed abnormal glial activation with reduced disease-associated microglia and astrocytes, and restored oligodendrocyte differentiation and myelin formation. No brain microhemorrhage or liver damage was detected following the AAV-antibody treatment. Thus, this AAV-mediated strategy offers a promising, convenient and safe AD therapeutic approach in the future.

Neuromodulators influence critical functions of the developing human brain and regulate behavioral states. Dysfunction of neuromodulatory systems is often involved in neuropsychiatric disease and many drugs for these conditions act on these signaling pathways. Recent advances in stem cell biology have made it possible to derive a wide range of cells across the developing human nervous system in regionalized organoids and to functionally integrate them into assembloids, however they currently do not systematically incorporate neuromodulation. Here, we generated human midbrain-hindbrain organoids (hMHO) from human induced pluripotent stem (hiPS) cells and fused them with human cortical organoids (hCO) to form neuromodulatory assembloids (hNMA). We focus on serotonin (5-hydroxytryptamine, 5-HT) as one key neuromodulator and found characteristic gene expression patterns and electrophysiological properties of serotonergic neurons (5-HT neurons) in the hMHO. In hNMA, 5-HT neurons projected into hCO, released 5-HT and modulated cortical network activity. To explore the applicability of this system in human disease, we studied 22q11.2 deletion syndrome (22q11.2DS), a common microdeletion associated with high risk for neuropsychiatric disease and defects in 5-HT signaling. We found aberrant 5-HT dynamics in hNMA from patient hiPS cell lines that were rescued by administration of a selective serotonin reuptake inhibitor (SSRI). Taken together, hNMA can be used to study human 5-HT dynamics and uncover disease phenotypes which could facilitate therapeutic development.

Profound degeneration of dopamine (DA) neurons and reduced DA levels in the brain is recognized as an underlying cause of Parkinsons Disease (PD). The standard treatment for PD is levodopa (L-DOPA), but its effectiveness wanes over time and prolonged usage can lead to L-DOPA-induced-dyskinesia (LID). An adeno-associated virus (AAV)-based strategy to overexpress aromatic l-amino acid decarboxylase (AADC) in the striatum combined with L-DOPA therapy shows promise for symptomatic improvement but requires an invasive delivery approach. Here, we generated enhancer AAVs to drive AADC expression in key cell types and paired them with a blood-brain barrier (BBB)-penetrant capsid. We characterized the AAVs in mouse following multiple routes of administration and found that cell-type specific viral treatment ameliorated motor deficits and LID in PD disease models. This cell type-specific viral rescue strategy showed similar or better phenotypic rescue compared to a ubiquitous targeting approach and improved mortality. Additionally, we characterized the expression of an AAV-AADC vector capable of mouse phenotypic rescue in non-human primate (NHP) following two routes of administration. This novel therapeutic strategy in combination with L-DOPA may enable a less invasive and better tolerated approach to treat motor deficits in PD patients.

SUMMERYAstrocytic dysfunction is closely associated with nearly all types of neurological diseases. Targeting astrocyte regulation has thus emerged as an important potential therapeutic strategy for neurological disorders. However, mechanisms that induce astrocyte dysfunction under pathological conditions have not been fully elucidated. In this study, we identified that Homeodomain-only protein X (Hopx) is downregulated in astrocytes across inflammatory models, Alzheimers disease (AD) mouse models, and brain tissues from AD patients. In the brains of AD mice, Hopx-positive astrocytes exhibit efficient {beta}-amyloid (A{beta}) plaque clearance, while knockout of Hopx leads to astrocytic dysfunction. Conversely, astrocyte-specific overexpression of Hopx not only significantly enhances their A{beta} phagocytic function but also effectively reduces the generation of neurotoxic astrocytes while increasing protective astrocytes. In summary, this study demonstrates the core regulatory mechanism underlying astrocytic dysfunction under AD pathological conditions and provides important potential targets for developing therapeutic strategies for AD by targeting astrocyte regulatory pathways.

Alzheimers disease (AD) is a common neurodegenerative disorder primarily caused by Amyloid-beta (A{beta}) toxicity. Therefore, there is an urgent need to develop novel, effective, and safe drugs to treat AD. Traditional Chinese Medicine (TCM) has a long history of use in protecting against memory impairments. Recently, TCM has attracted growing attention from researchers as a source of potent neuroprotective compounds. In this study, we focus on four TCM herbs with multiple therapeutic properties: Valeriana jatamansi (V; 20 mg/mL), Acori tatarinowii (A; 10 mg/mL), Fructus Schisandrae (F; 5 mg/mL), and Scutellaria baicalensis (S; 2.5 mg/mL). The aim is to develop a neuroprotective anti-AD formulation, named "Zhi-Shi-Wu-Huang" derived from V, A, F, and S, and evaluate its efficacy in transgenic Caenorhabditis elegans models of AD. These four TCM herbs are among the most potent activators of the HSP-70 promoter, promoting the expression of heat shock protein 70 (HSP-70), which helps prevent protein misfolding and aggregation. Additionally, V, A, F, S, and the Zhi-Shi-Wu-Huang formula were found to reduce reactive oxygen species (ROS) production and enhance the expression of superoxide dismutase-3 (sod-3) and chymotrypsin-like proteasomes. Our findings demonstrate that both the individual extracts (V, A, F, S) and the Zhi-Shi-Wu-Huang formulation significantly reduce A{beta}-induced toxicity in transgenic worms by activating the insulin/DAF-16 signaling pathway.

Recurrent hypoglycemia increases cognitive impairment in diabetes mellitus patients. Following cerebral neuron injury, endothelial cells provide morphological, metabolic and immune support to damaged neurons. We investigated the inflammatory mechanism involved in hippocampal neuron degeneration. Behavioral experiments, including the open field test (OFT) and the Morris water maze test, were performed to measure cognitive changes. Using a vascular ring experiment, we evaluated vasodilation of the carotid artery. ZBP1 expression was knocked down after transfection with small interfering RNA in a brain endothelial cell line (bEnd3). In this study, PANoptosis, a recently defined form of programmed cell death (PCD), was found to be increased by hypoglycemia in the hippocampus of type 2 diabetic mice in vivo and by low glucose in bEnd3 cells in vitro. ZBP1 knockdown decreased PANoptosis induced by low-glucose stimulation in high-glucose-cultivated bEnd3 cells. RNA transcriptomics sequencing revealed that AGE-RAGE signaling significantly changed after ZBP1 was knocked down in bEnd3 cells. Corresponding biochemical data confirmed that ZBP1 knockdown regulated the advanced glycation end products (AGEs)-Receptor for Advanced Glycation End Products (RAGE) axis in bEnd3 cells. We present the first evidence that hypoglycemia impaired cognition in mice with type 2 diabetes by activating brain endothelial ZBP1-mediated PANoptosis via the AGE-RAGE axis. ARTICLE HIGHLIGHTSO_LIPANoptosis, a newly defined form of programmed cell death, is induced in the hippocampus after recurrent hypoglycemia in male db/db mice. C_LIO_LIZBP1, a sensor of the PANoptosome, was activated in low glucose cultured brain endothelial cells. C_LIO_LIHypoglycemia impairs vasodilation and cognitive function in type 2 diabetic mice. C_LIO_LIOur study indicates that inhibiting ZBP1-PANoptosis and the AGE-RAGE axis may be a potential approach to prevent hypoglycemia-induced cognitive degeneration in individuals with type 2 diabetes. C_LI

Alzheimers disease (AD) is a devastating neurodegenerative disease whose etiology is poorly understood and for which current treatments provide only modest control of symptoms. To better investigate the causes and progression of the disease, the transgenic TgF344-AD rat model has emerged as a crucial tool. In this paper, we collect observations on the accumulation of amyloid-{beta}, changes in neuronal density, and a decline in cognitive performance in TgF344-AD and wild-type rats. We develop a compartmental ordinary differential equation model and determine its parameters by fitting the output to the experimental observations. Our model simulations support the hypothesis that the accumulation of amyloid-{beta} leads to a rapid decline in neuronal density followed by a significant loss in memory and learning ability. Our mathematical model can provide a bridge between AD research in rodent models and the human condition of AD.

The Subthalamic Nucleus (STN) regulates movement and is an important clinical target for deep brain stimulation (DBS) in Parkinsons Disease (PD). However, it remains unclear how dopamine loss and DBS influence STN gait encoding. We performed simultaneous recordings from multiple neurons and intermittent DBS in the STN of healthy and dopamine depleted PD mice during voluntary locomotion. We found that dopamine loss resulted in gait deficits manifested as altered stride length of both hindlimbs and forelimbs, which were rescued by intermittent DBS. Furthermore, dopamine loss exaggerated movement encoding of STN population dynamics, and elevates individual STN spiking during movement and beta-rhythmic firing at rest. Despite an overall increase in the fraction of neuron activated by movement, individual neurons gait encoding properties remain similar between healthy and PD mice. While DBS suppressed firing in both healthy and PD mice, it selectively reduced STN beta-rhythmic spiking, desynchronized STN networks, and rescued gait deficits associated with the loss of dopamine. These results suggest that pathological activation and beta synchronization of the STN contributes to motor deficits related to PD, and DBS-induced reduction of beta rhythmic spiking and STN network desynchronization contribute to the therapeutic effects of DBS in PD.

Parkinsons disease (PD) is the second most progressive degenerative disorder of the brain due to dopaminergic (DA) neuron degenerations and alpha-synuclein (-Syn) accumulations. At present, the disease has no effective treatment. Therefore, the current study objective is to identify a novel anti-PD formula (Zhi-Shi-Huang-Wu Formula, F-2) computed at 8:4:2:1 ratio from HSP 70 promoter activators Valeriana jatamansi (V), Acori talarinowii (A), Scutellaria baicalensis (S), Fructus Schisandrae (F). Traditionally, V is used to cure memory impairments, A treats mental disorders, and chronic mild stress, S for neuroprotection, and F showed multiple therapeutic actions to treat insomnia. This study investigated the neuroprotective potential of the V, A, S, F, formula F-2 and its underlying molecular mechanisms in transgenic Caenorhabditis elegans models. A, S, F, and F-2 successfully restored 6-hydroxydopamine intoxicated DA neuron degenerations, reduced food-sensing behavior disabilities, and attenuated -Syn aggregations. Moreover, activates the lipid deposition and proteasome expressions to confirm -Syn degradations at the cellular level. Reactive oxygen species (ROS) cause oxidative stress, and A, S, F, and F-2 repressed ROS and raised SOD-3 expressions. Overall, these data indicate that V, A, S, F combined into F-2 (22.3%) are more effective against PD progression-like symptom than individual drugs V (0.7%), A (11.4%), S (9.6%), and F (12.6%). These improved neuroprotective actions of F-2 possibly due to following the antioxidative pathway. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=144 SRC="FIGDIR/small/709540v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@1a6f1f7org.highwire.dtl.DTLVardef@157a270org.highwire.dtl.DTLVardef@69a238org.highwire.dtl.DTLVardef@1194b5e_HPS_FORMAT_FIGEXP M_FIG C_FIG

The gut-brain axis has emerged as a crucial factor in neurodegeneration, with growing evidence linking gut dysbiosis and metabolic dysfunction to Alzheimers disease (AD) progression. Unfortunately, the lack of human-relevant in vitro models limits our ability to effectively explore the mechanism of this axis. To address this gap, we have developed a human induced pluripotent stem cell (iPSC)-derived gut-blood-brain barrier (BBB)-brain microphysiological system that enables systematic investigation of gut-brain interaction in the context of AD under controlled conditions. Our findings reveal that the interaction between gut and brain organoids can promote the maturation of brain organoids, making them more similar to their physiological characteristics in vivo. Additionally, co-culture gut and brain organoids better recapitulates the pathological features of AD. We also discovered that gut organoids of AD can trigger neurodegenerative disease manifestations in healthy brain organoids. In summary, our microphysiological system provides a novel and versatile in vitro platform for studying the interaction between the gut and brain in neurodegenerative diseases.

Tumor heterogeneity highlights the necessity of precision cancer medicine, making the evaluation and screening of anticancer drugs a core challenge in cancer therapy. However, current cell-based efficacy assessment methods struggle to quantify the holistic impact of drugs on cellular behavior through specific target engagement. Here, we proposed a novel approach (DL-TCP-FRET) that integrates phenotypic and target-related evaluations: the logistic fitting analysis is performed on time- and concentration-dependent cellular phenotypic characteristics to construct a phenotypic score (P), while a target score (T) is established based on the FRET efficiency between target proteins. These two scores were then further combined to generate a unified drug efficacy score (PT). Validation in A549 cells demonstrated that our method can reliably distinguish EGFR-TKIs from non-targeted drugs. DL-TCP-FRET simplifies the experimental workflow of drug efficacy evaluation and improves the accuracy of targeted drug identification, providing a novel strategy for advancing precision cancer therapy.

The impact of cellular activities on large-scale brain dynamics is thought to determine brain functioning and disease, yet the causal relationships of neural mechanisms across scales remain unclear. Recently, the cerebellum has been reported to affect whole-brain dynamics during sensorimotor integration. To disclose the underlying mechanisms, we have developed a multiscale digital brain co-simulator, in which a spiking neural network of the olivo-cerebellar microcircuit is embedded in a mouse virtual brain and wired with other nodes using an atlas-based long-range connectome. Parameters and bi-directional interfaces between the spiking olivo-cerebellar network and other rate-coded modules were tuned to match experimental data of primary sensory and motor cortex (M1 and S1) power spectral densities and neuronal spiking rates. Then, the role of the cerebellar circuitry on sensorimotor integration was analyzed by lesioning critical circuit connections in silico. Simulations showed that spike processing within the cerebellar circuit is key to explaining the gamma-band coherence between M1 and S1 during sensorimotor integration. These results provide a mechanistic explanation of how the cerebellum promotes the formation of sensorimotor contingencies in relevant cortical modules as the basis of its critical role in sensorimotor prediction. On a broader perspective, this modelling approach opens new perspectives for the multiscale investigation of brain physiological and pathological states in relation to specific cellular and microcircuit properties.

The Lymphocyte antigen-6 (Ly6)/urokinase-type plasminogen activator receptor (uPAR) superfamily (LU super family) of proteins are involved in diverse biological processes. In Drosophila melanogaster, members of the LU superfamily have undergone lineage-specific gene duplication and acquired specialized functions in distinct tissues. A glycosylphosphatidylinositol (GPI)-anchored LU family protein Belly roll (Bero) has recently been shown to regulate larval escape behavior; however, its cellular expression profile and potential roles remain incompletely understood. In this study, we generated a bero-GAL4T2A transgenic line to delineate endogenous bero expression. This analysis revealed that bero is expressed in the peptidergic neurons in the central nervous system (CNS) that had not been documented in previous studies, as well as in the peripheral nervous system (PNS) and non-neuronal tissues, such as the anal pad and epidermis. Reanalysis of publicly available single-cell RNA sequencing (scRNA-seq) datasets demonstrated that bero is expressed in several peptidergic neurons. These findings suggest that Bero is specifically expressed in diverse peptidergic neurons and may play important roles in coordinating hormonal and neural regulation in D. melanogaster.

Alzheimers disease (AD) is the most prevalent form of dementia, characterized by progressive memory loss, cognitive decline, and emotional dysregulation. Adult hippocampal neurogenesis (AHN) critically contributes to cognition and mood but undergoes precipitous decline during AD progression. Here, we investigated whether enhancing AHN through genetic expansion of endogenous neural stem cells (NSC) ameliorates AD-related phenotypes. Using lentiviral overexpression of the cell cycle regulators Cdk4 and CyclinD1 in the dentate gyrus of 3xTg-AD mouse, we show that enhancing AHN partially rescues hippocampal-specific cognitive functions, namely: spatial navigation and exploratory behavior. These findings show that endogenous NSC can be exploited to ameliorate hippocampal cognitive functions in AD, providing additional evidence for exploiting AHN as a promising therapeutic target for neurodegenerative disease.

Dynamic sensory processing helps animals adjust behaviors in response to changing environments and internal states. Hunger is a salient internal cue that can directly modify chemosensory signaling to promote homeostatic behavior. In Drosophila melanogaster, hunger enhances the sensitivity of sweet gustatory receptor neurons (GRNs) to encourage feeding, and here we investigated candidate hunger/satiety hormone receptors to identify mechanisms of metabolic regulation in primary taste cells. The conserved insulin receptor (InR) is expressed in sweet GRNs, and targeted InR knockdown and inactivation within these cells elevated sucrose sensitivity, increased sucrose consumption, and altered feeding behavior under sated conditions. Additionally, sweet cellular responses to sucrose were reciprocally affected by inactive and overactive InR signaling. These findings reveal that InR signaling can modulate sweet sensitivity at the level of primary taste cells, suppressing feeding by reducing taste responsiveness under specific metabolic conditions.

Long noncoding RNAs (LncRNAs) have emerged as a class of important regulatory ncRNAs and are known to fine-tune numerous cellular processes including proliferation, differentiation and development; however, their role in quiescence still remains largely unexplored. A miRNA host gene lncRNA, MIR503HG, has been reported to play important role in cancer development. Here, we demonstrate the role of MIR503HG lncRNA in regulating cellular quiescence. MIR503HG displays elevated levels in human diploid fibroblasts induced to undergo quiescence. Depletion of MIR503HG in HDFs affects the entry of cells into quiescence but has no effect on cell cycle progression, suggesting its role in quiescence attainment and/or maintenance. Additionally, MIR503HG depletion led to a drastic decrease in the levels of miR508 target, PTEN with a concomitant increase in pAkt levels, indicating its role in negative regulation of miR508. Further, we demonstrate that the lncRNA MIR503HG regulates PTEN levels by acting as a ceRNA for miR508 to maintain cellular quiescence. Our studies illustrate that MIR503HG can function synergistically with miR503 to maintain cells under quiescence and both the miRNA-HG and the miRNA encoded by its gene locus synergistically control the same biological process in different ways by regulating different downstream genes.

Although the causes of Tau aggregates vary, once Tau aggregates are formed, their neurotoxicity significantly contributes to neuronal death and cognitive decline in tauopathies, with Alzheimers disease (AD) being the most well-known example. Despite its central pathogenic role, however, effective therapeutic strategies targeting neurotoxicity of Tau remain poor. Here we demonstrate the pathogenic role of neuronal cell death in Tau-related neurodegeneration. Tau-expressing neurons undergo cell death through Z-DNA-binding protein 1 (ZBP1) activation triggered by endogenous Z-RNAs. These Z-RNAs are derived from reactivated transposable elements (TEs) that are typically silenced within heterochromatin. Tau aggregates show a strong affinity for H3K9me3-modified chromatin, effectively sequestering these epigenetic marks from Heterochromatin Protein 1 (HP1), thereby disrupting the condensation of constitutive heterochromatin. Clinically, an inverse correlation between ZBP1 expression levels in excitatory neurons and cognitive performance in AD patients was observed. Importantly, Zbp1 haploinsufficiency significantly ameliorated cognitive deficits in aged Tau-transgenic mice (24-month-old), highlighting the therapeutic potential of ZBP1 inhibition to strive against neurodegeneration in tauopathies.