Neuron-targeted liposomal coenzyme Q10 attenuates neuronal ferroptosis after subarachnoid hemorrhage by activating the ferroptosis suppressor protein 1/coenzyme Q10 system.

Subarachnoid hemorrhage (SAH) is primarily attributed to the rupture of intracranial aneurysms and is associated with a high incidence of disability and mortality. SAH disrupts the blood‒brain barrier, leading to the release of iron ions from blood within the subarachnoid space, subsequently inducing neuronal ferroptosis. A recently discovered protein, known as ferroptosis suppressor protein 1 (FSP1), exerts anti-ferroptotic effects by facilitating the conversion of oxidative coenzyme Q 10 (CoQ10) to its reduced form, which effectively scavenges reactive oxygen radicals and mitigates iron-induced ferroptosis. In our investigation, we observed an increase in FSP1 levels following SAH. However, the depletion of CoQ10 caused by SAH hindered the biological function of FSP1. Therefore, we created neuron-targeted liposomal CoQ10 by introducing the neuron-targeting peptide Tet1 onto the surface of liposomal CoQ10. Our objective was to determine whether this formulation could activate the FSP1 system and subsequently inhibit neuronal ferroptosis. Our findings revealed that neuron-targeted liposomal CoQ10 effectively localized to neurons at the lesion site after SAH. Furthermore, it facilitated the upregulation of FSP1, reduced the accumulation of malondialdehyde and reactive oxygen species, inhibited neuronal ferroptosis, and exerted neuroprotective effects both in vitro and in vivo. Our study provides evidence that supplementation with CoQ10 can effectively activate the FSP1 system. Additionally, we developed a neuron-targeted liposomal CoQ10 formulation that can be selectively delivered to neurons at the site of SAH. This innovative approach represents a promising therapeutic strategy for neuronal ferroptosis following SAH. STATEMENT OF SIGNIFICANCE: Subarachnoid hemorrhage (SAH) is primarily attributed to the rupture of intracranial aneurysms and is associated with a high incidence of disability and mortality. Ferroptosis suppressor protein 1 (FSP1), exerts anti-ferroptotic effects by facilitating the conversion of oxidative coenzyme Q 10 (CoQ10) to its reduced form, which effectively scavenges reactive oxygen radicals and mitigates iron-induced ferroptosis. In our investigation, we observed an increase in FSP1 levels following SAH. However, the depletion of CoQ10 caused by SAH hindered the biological function of FSP1. Therefore, we created neuron-targeted liposomal CoQ10. We find that it effectively localized to neurons at the lesion site after SAH and activated the FSP1/CoQ10 system. This innovative approach represents a promising therapeutic strategy for neuronal ferroptosis following SAH and other central nervous system diseases characterized by disruption of the blood-brain barrier.

Molecular Mechanisms of Medicinal Plant Securinega suffruticosa-derived Compound Securinine against Spinal Muscular Atrophy based on Network Pharmacology and Experimental Verification.

BACKGROUND: Spinal Muscular Atrophy (SMA) is a severe motor neuronal disorder with high morbidity and mortality. Securinine has shown the potential to treat SMA; however, its anti-SMA role remains unclear. OBJECTIVE: This study aims to reveal the anti-SMA mechanisms of securinine. METHODS: Securinine-associated targets were acquired from Herbal Ingredients' Targets (HIT), Similarity Ensemble Approach (SEA), and SuperPred. SMA-associated targets were obtained from GeneCards and Dis- GeNET. Protein-protein Interaction (PPI) network was constructed using GeneMANIA, and hug targets were screened using cytoHubba. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed using ClusterProfifiler. Molecular docking was conducted using Pymol and Auto- Dock. In vitro assays were used to verify the anti-SMA effects of securinine. RESULTS: Twenty-six intersection targets of securinine and SMA were obtained. HDAC1, HDAC2, TOP2A, PIK3R1, PRMT5, JAK2, HSP90AB1, TERT, PTGS2, and PAX8 were the core targets in PPI network. GO analysis demonstrated that the intersecting targets were implicated in the regulation of proteins, steroid hormones, histone deacetylases, and DNA transcription. KEGG analysis, pathway-pathway, and hub target-pathway networks revealed that securinine might treat SMA through TNF, JAK-STAT, Ras, and PI3K-Akt pathways. Securinine had a favorable binding affinity with HDAC1, HSP90AB, JAK2, PRMT5, PTGS2, and TERT. Securinine rescued viability suppression, mitochondria damage, and SMN loss in the SMA cell model. Furthermore, securinine increased HDAC1 and PRMT5 expression, decreased PTGS2 expression, suppressed the JAK2-STAT3 pathway, and promoted the PI3K-Akt pathway. CONCLUSION: Securinine might alleviate SMA by elevating HDAC1 and PRMT5 expression and reducing PTGS2 via JAK2-STAT3 suppression and PI3K-Akt activation.

Gut dysbiosis impairs intestinal renewal and lipid absorption in Scarb2 deficiency-associated neurodegeneration.

Scavenger receptor class B, member 2 (SCARB2) is linked to Gaucher disease (GD) and Parkinson's disease (PD). Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy (PME), a rare group of inherited neurodegenerative diseases characterized by myoclonus. We found that Scarb2 deficiency in mice leads to age-dependent dietary lipid malabsorption, accompanied with vitamin E deficiency. Our investigation revealed that Scarb2 deficiency is associated with gut dysbiosis and an altered bile acid pool, leading to hyperactivation of FXR in intestine. Hyperactivation of FXR impairs epithelium renewal and lipid absorption. Patients with SCARB2 mutations have a severe reduction in their vitamin E levels and cannot absorb dietary vitamin E. Finally, inhibiting FXR or supplementing vitamin E ameliorates the neuromotor impairment and neuropathy in Scarb2 knockout mice. These data indicate that gastrointestinal dysfunction is associated with SCARB2 deficiency-related neurodegeneration, and SCARB2-associated neurodegeneration can be improved by addressing the nutrition deficits and gastrointestinal issues.

Responsive regularity of neurons in the hindlimb region of primary somatosensory cortex to different temperature thermal needle stimulation of "Zusanli"(ST36) in mice. / å°é¼ åˆçº§ä½“æ„Ÿçš®å±‚åŽè‚¢åŒºç¥žç»å ƒå¯¹"足三里"不同温度热刺激的响应规律.

OBJECTIVES: To study the regularity of central response to thermal needle stimulation of "Zusanli" (ST36) at different temperature, and to analyze the temperature difference of central responses. METHODS: Six male C57BL/6j adult mice were used in the present study. For observing activities of neurons in the hindlimb region of left primary somatosensory cortex (S1HL, A/P=0.46 mm, M/L=1.32 mm, D/V=-0.14 mm) by using a fast high-resolution miniature two-photon microscopy (FHIRM-TPM), the mice were anesthetized with 3% isoflurane (inhalation), with its head fixed in a stereotaxic apparatus, then, adeno-associated virus (AAV-hSyn-GCaMP6f-WPRE-hGHpA, for showing intracellular calcium transients in neurons transfected) was injected into the left S1HL region using a micro-syringe after scalp surgical operation. The mice's right ST36 were stimulated using internal thermal needles with the temperature being 43 ℃, or 45 ℃, or 47 ℃, separately. Image J software and MATLAB 2020b software were used to process the image data of neuronal calcium activity (Ca2+ signaling) in the left S1HL region, including the instant maximum calcium peak value (ΔF/F) in 2 s, instant calcium spike frequency in 2 s, short-term calcium peak value (ΔF/F) in 3.5 min, short-term calcium spike frequency in 3.5 min, calcium peak duration in 3.5 min, maximum calcium peak value (ΔF/F) at the 1st , 2nd and 3rd min, and calcium spike frequency at the 1st, 2nd and 3rd min after thermal needle stimulation. RESULTS: In comparison with the normal temperature needle stimulation, the instant intracellular maximum calcium peak value, instant calcium spike frequency, short-term maximum calcium peak value, short-term calcium spike frequency, and calcium peak duration of S1HL neurons in response to 43 ℃, 45 ℃ and 47 ℃ internal thermal needle stimulation of ST36 were significantly increased (P<0.001, P<0.01). Comparison among the 43 ℃, 45 ℃ and 47 ℃ thermal needle stimulation showed that the 45 ℃ thermal needle stimulation was obviously superior to 43 ℃ and 47 ℃ thermal needle stimulation in increasing instant calcium spike frequency, short-term calcium spike frequency and calcium peak duration of S1HL neurons (P<0.001, P<0.01). The 47 ℃ thermal needle stimulation was stronger than 43 ℃ and 45 ℃ thermal needle stimulation in increasing the instant maximum calcium peak value (P<0.001). The maximum calcium peak value was apparently higher (P<0.001) at the 2nd min than that at the 1st and 3rd min after 43 ℃, 45 ℃ and 47 ℃ thermal needle stimulation. No significant differences were found in the short-term maximum calcium peak value among the 3 thermal needle stimulation and in the calcium spike frequency among the 3 time points after 43 ℃, 45 ℃ and 47 ℃ thermal needle stimulation. CONCLUSIONS: S1HL neurons respond to all 43 ℃, 45 ℃ and 47 ℃ thermal needle stimulation of ST36 in mice, while more actively to 45 ℃ thermal needle stimulation.

Electroacupuncture alleviates intestinal inflammation via a distinct neuro-immune signal pathway in the treatment of postoperative ileus.

BACKGROUND: The induction of intestinal inflammation as a result of abdominal surgery is an essential factor in postoperative ileus (POI) development. Electroacupuncture (EA) at ST36 has been demonstrated to relieve intestinal inflammation and restore gastrointestinal dysmotility in POI. This study aims to elucidate the neuroimmune pathway involved in the anti-inflammatory properties of EA in POI. METHODS: After intestinal manipulation (IM) was performed to induce POI, intestinal inflammation and motility were assessed 24 h post-IM, by evaluating gastrointestinal transit (GIT), cytokines expression, and leukocyte infiltration. Experimental surgery, pharmacological intervention, and genetic knockout mice were used to elucidate the neuroimmune mechanisms of EA. RESULTS: EA at ST36 significantly improved GIT and reduced the expression of pro-inflammatory cytokines and leukocyte infiltration in the intestinal muscularis following IM in mice. The anti-inflammatory effectiveness of EA treatment was abolished by sub-diaphragmatic vagotomy, whereas splenectomy did not hinder the anti-inflammatory benefits of EA treatment. The hexamethonium chloride (HEX) administration contributes to a notable reduction in the EA capacity to suppress inflammation and enhance motility dysfunction, and EA is ineffective in α7 nicotinic acetylcholine receptor (α7nAChR) knockout mice. CONCLUSIONS: EA at ST36 prevents intestinal inflammation and dysmotility through a neural circuit that requires vagal innervation but is independent of the spleen. Further findings revealed that the process involves enteric neurons mediating the vagal signal and requires the presence of α7nAChR. These findings suggest that utilizing EA at ST36 may represent a possible therapeutic approach for POI and other immune-related gastrointestinal diseases.

Iron overload in hypothalamic AgRP neurons contributes to obesity and related metabolic disorders.

Iron overload is closely associated with metabolic dysfunction. However, the role of iron in the hypothalamus remains unclear. Here, we find that hypothalamic iron levels are increased, particularly in agouti-related peptide (AgRP)-expressing neurons in high-fat-diet-fed mice. Using pharmacological or genetic approaches, we reduce iron overload in AgRP neurons by central deferoxamine administration or transferrin receptor 1 (Tfrc) deletion, ameliorating diet-induced obesity and related metabolic dysfunction. Conversely, Tfrc-mediated iron overload in AgRP neurons leads to overeating and adiposity. Mechanistically, the reduction of iron overload in AgRP neurons inhibits AgRP neuron activity; improves insulin and leptin sensitivity; and inhibits iron-induced oxidative stress, endoplasmic reticulum stress, nuclear factor κB signaling, and suppression of cytokine signaling 3 expression. These results highlight the critical role of hypothalamic iron in obesity development and suggest targets for treating obesity and related metabolic disorders.

Involvement of NOTCH1-mediated Microglia Activation in Neuromodulation of Chronic Prostatitis-related Pain.

BACKGROUND/AIM: This study aimed to investigate the role of NOTCH receptor 1 (NOTCH1)-mediated activation of microglia in the L5-S2 spinal dorsal horn in chronic prostatitis pain. MATERIALS AND METHODS: Rats were divided into chronic prostatitis (CP) group and control group. Complete Freund's adjuvant was injected into the prostate, and prostate pathology and pain-related behavior were monitored to assess the successful establishment of the CP-related pain model. The dorsal horn of the L5-S2 spinal cord was collected for the detection of ionized calcium-binding adapter molecule 1 (IBA-1) and NOTCH1 expression by quantitative real time polymerase chain reaction and the detection of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) by enzyme-linked immunosorbent assay. Electrical excitability was assessed with whole-cell patch clamp. In addition, NOTCH1 receptor inhibitor or inhibitor of microglial cell activation was injected into the subarachnoid space, and the pro-inflammatory cytokines in the spinal cord were detected. RESULTS: In the CP group, the expression of NOTCH1, IBA-1, TNF-α and IL-1ß began to increase at 4 days, peaked at 12 days, and began to decline at 24 days, and it was significantly higher than in the control group (p<0.01). Inhibition of microglia or NOTCH1 receptor markedly reduced the content of TNF-α and IL-1ß in the spinal cord (p<0.05). At 4, 12 and 24 days, the amplitude and frequency of neuronal action potential increased and the threshold decreased markedly as compared to the control group (p<0.05), and spontaneous action potential was noted. CONCLUSION: NOTCH1 mediates the activation of microglia in the L5-S2 spinal cord, leading to the secretion of inflammatory factors and enhanced electrical excitability of neurons, which is related to persistent and refractory chronic prostatitis-related pain.

O-GlcNAc signaling increases neuron regeneration through one-carbon metabolism in Caenorhabditis elegans.

Cellular metabolism plays an essential role in the regrowth and regeneration of a neuron following physical injury. Yet, our knowledge of the specific metabolic pathways that are beneficial to neuron regeneration remains sparse. Previously, we have shown that modulation of O-linked ß-N-acetylglucosamine (O-GlcNAc) signaling, a ubiquitous post-translational modification that acts as a cellular nutrient sensor, can significantly enhance in vivo neuron regeneration. Here, we define the specific metabolic pathway by which O-GlcNAc transferase (ogt-1) loss of function mediates increased regenerative outgrowth. Performing in vivo laser axotomy and measuring subsequent regeneration of individual neurons in C. elegans, we find that glycolysis, serine synthesis pathway (SSP), one-carbon metabolism (OCM), and the downstream transsulfuration metabolic pathway (TSP) are all essential in this process. The regenerative effects of ogt-1 mutation are abrogated by genetic and/or pharmacological disruption of OCM and the SSP linking OCM to glycolysis. Testing downstream branches of this pathway, we find that enhanced regeneration is dependent only on the vitamin B12 independent shunt pathway. These results are further supported by RNA sequencing that reveals dramatic transcriptional changes by the ogt-1 mutation, in the genes involved in glycolysis, OCM, TSP, and ATP metabolism. Strikingly, the beneficial effects of the ogt-1 mutation can be recapitulated by simple metabolic supplementation of the OCM metabolite methionine in wild-type animals. Taken together, these data unearth the metabolic pathways involved in the increased regenerative capacity of a damaged neuron in ogt-1 animals and highlight the therapeutic possibilities of OCM and its related pathways in the treatment of neuronal injury.

Dry needling combined with exercise therapy: Effects on wrist flexors spasticity in post-stroke patients - A randomized controlled trial.

BACKGROUND: The positive contribution of dry needling (DN) in conjunction with exercise therapy for patients with stroke and spasticity remains uncertain. OBJECTIVE: To examine the effects of DN combined with exercise therapy on wrist flexor spasticity and motor function in patients with stroke. METHODS: Twenty-four participants with stroke were randomly assigned to either the DN and exercise therapy group or the DN alone group. Assessments were conducted at baseline, after the 4th treatment session, and 3 weeks post-treatment. RESULTS: A significant Group×Time interaction was observed for wrist active range of motion (ROM) (P = 0.046), favoring the DN with exercise therapy group (∼10° at baseline, ∼15° immediately after the 4th session, and 15.4° at follow-up). The improvements in spasticity, passive ROM, and H-reflex latency were sustained during follow-up. However, there were no significant between-group differences in any outcome at any measurement time point. CONCLUSION: The combined DN and exercise therapy did not exhibit superiority over DN alone concerning spasticity severity and motor function. However, it demonstrated additional advantages, particularly in improving motor neuron excitability and wrist passive extension.

Npy transcription is regulated by noncanonical STAT3 signaling in hypothalamic neurons: Implication with lipotoxicity and obesity.

Neuropeptide Y (Npy) is an abundant neuropeptide expressed in the central and peripheral nervous systems. NPY-secreting neurons in the hypothalamic arcuate nucleus regulate energy homeostasis, and Npy mRNA expression is regulated by peripheral nutrient and hormonal signals like leptin, interleukin-6 (IL-6), and fatty acids. This study demonstrates that IL-6, which phosphorylates tyrosine 705 (Y705) of STAT3, decreased Npy mRNA in arcuate immortalized hypothalamic neurons. In parallel, inhibitors of STAT3-Y705 phosphorylation, stattic and cucurbitacin I, robustly upregulated Npy mRNA. Chromatin-immunoprecipitation showed high baseline total STAT3 binding to multiple regulatory regions of the Npy gene, which are decreased by IL-6 exposure. The STAT3-Npy interaction was further examined in obesity-related pathologies. Notably, in four different hypothalamic neuronal models where palmitate potently stimulated Npy mRNA, Socs3, a specific STAT3 activity marker, was downregulated and was negatively correlated with Npy mRNA levels (R2 = 0.40, p < 0.001), suggesting that disrupted STAT3 signaling is involved in lipotoxicity-mediated dysregulation of Npy. Finally, human NPY SNPs that map to human obesity or body mass index were investigated for potential STAT3 binding sites. Although none of the SNPs were linked to direct STAT3 binding, analysis show that rs17149106 (-602 G > T) is located on an upstream enhancer element of NPY, where the variant is predicted to disrupt validated binding of KLF4, a known inhibitory cofactor of STAT3 and downstream effector of leptin signaling. Collectively, this study demonstrates that STAT3 signaling negatively regulates Npy transcription, and that disruption of this interaction may contribute to metabolic disorders.

Single-neuron projectomes of mouse paraventricular hypothalamic nucleus oxytocin neurons reveal mutually exclusive projection patterns.

Oxytocin (OXT) plays important roles in autonomic control and behavioral modulation. However, it is unknown how the projection patterns of OXT neurons align with underlying physiological functions. Here, we present the reconstructed single-neuron, whole-brain projectomes of 264 OXT neurons of the mouse paraventricular hypothalamic nucleus (PVH) at submicron resolution. These neurons hierarchically clustered into two groups, with distinct morphological and transcriptional characteristics and mutually exclusive projection patterns. Cluster 1 (177 neurons) axons terminated exclusively in the median eminence (ME) and have few collaterals terminating within hypothalamic regions. By contrast, cluster 2 (87 neurons) sent wide-spread axons to multiple brain regions, but excluding ME. Dendritic arbors of OXT neurons also extended outside of the PVH, suggesting capability to sense signals and modulate target regions. These single-neuron resolution observations reveal distinct OXT subpopulations, provide comprehensive analysis of their morphology, and lay the structural foundation for better understanding the functional heterogeneity of OXT neurons.

Temperature-Dependent Olive Pomace Extraction for Obtaining Bioactive Compounds Preventing the Death of Murine Cortical Neurons.

High-pressure and temperature extraction (HPTE) can effectively recover bioactive compounds from olive pomace (OP). HPTE extract obtained by extracting OP with ethanol and water (50:50 v/v) at 180 °C for 90 min demonstrated a pronounced ability to preserve intracellular calcium homeostasis, shielding neurons from the harmful effects induced by N-methyl-d-aspartate (NMDA) receptor (NMDAR) overactivation, such as aberrant calpain activation. In this study, the extraction temperature was changed from 37 to 180 °C, and the extracts were evaluated for their antioxidant potency and ability to preserve crucial intracellular Ca2+-homeostasis necessary for neuronal survival. Additionally, to verify the temperature-induced activity of the extract, further extractions on the exhausted olive pomace were conducted, aiming to identify variations in the quality and quantity of extracted phenolic molecules through HPLC analysis. The results revealed a significant increase in bioactive compounds as a function of temperature variation, reaching 6.31 ± 0.09 mgCAE/mL extract for the extraction performed at 180 °C. Subsequent extraction of the exhausted residues yielded extracts that remained active in preventing calcium-induced cell death. Moreover, despite increased antiradical power, extracts re-treated at 180 °C did not display cell protection activity. Our results indicate that the molecules able to maintain physiological Ca2+-homeostasis in murine cortical neurons in conditions of cytotoxic stimulation of NMDAR are wholly recovered from olive pomace only following extraction performed at 180 °C.

2(3H)-Dihydrofranolactone metabolites from Pleosporales sp. NUH322 as anti-amyotrophic lateral sclerosis drugs.

Amyotrophic lateral sclerosis (ALS) is a devastating motor disease with limited treatment options. A domestic fungal extract library was screened using three assays related to the pathophysiology of ALS with the aim of developing a novel ALS drug. 2(3H)-dihydrofuranolactones 1 and 2, and five known compounds 3-7 were isolated from Pleosporales sp. NUH322 culture media, and their protective activity against the excitotoxicity of ß-N-oxalyl-L-α,ß-diaminopropionic acid (ODAP), an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamatergic agonist, was evaluated under low mitochondrial glutathione levels induced by ethacrynic acid (EA) and low sulfur amino acids using our developed ODAP-EA assay. Additional assays evaluated the recovery from cytotoxicity caused by transfected SOD1-G93A, an ALS-causal gene, and the inhibitory effect against reactive oxygen species (ROS) elevation. The structures of 1 and 2 were elucidated using various spectroscopic methods. We synthesized 1 from D-ribose, and confirmed the absolute structure. Isolated and synthesized 1 displayed higher ODAP-EA activities than the extract and represented its activity. Furthermore, 1 exhibited protective activity against SOD1-G93A-induced toxicity. An ALS mouse model, SOD1-G93A, of both sexes, was treated orally with 1 at pre- and post-symptomatic stages. The latter treatment significantly extended their lifespan (p = 0.03) and delayed motor deterioration (p = 0.001-0.01). Our result suggests that 1 is a promising lead compound for the development of ALS drugs with a new spectrum of action targeting both SOD1-G93A proteopathy and excitotoxicity through its action on the AMPA-type glutamatergic receptor.

Is functional electrical stimulation effective in improving walking in adults with lower limb impairment due to an upper motor neuron lesion? An umbrella review.

PURPOSE: To conduct an umbrella review of systematic reviews on functional electrical stimulation (FES) to improve walking in adults with an upper motor neuron lesion. METHODS: Five electronic databases were searched, focusing on the effect of FES on walking. The methodological quality of reviews was evaluated using AMSTAR2 and certainty of evidence was established through the GRADE approach. RESULTS: The methodological quality of the 24 eligible reviews (stroke, n = 16; spinal cord injury (SCI), n = 5; multiple sclerosis (MS); n = 2; mixed population, n = 1) ranged from critically low to high. Stroke reviews concluded that FES improved walking speed through an orthotic (immediate) effect and had a therapeutic benefit (i.e., over time) compared to usual care (low certainty evidence). There was low-to-moderate certainty evidence that FES was no better or worse than an Ankle Foot Orthosis regarding walking speed post 6 months. MS reviews concluded that FES had an orthotic but no therapeutic effect on walking. SCI reviews concluded that FES with or without treadmill training improved speed but combined with an orthosis was no better than orthosis alone. FES may improve quality of life and reduce falls in MS and stroke populations. CONCLUSION: FES has orthotic and therapeutic benefits. Certainty of evidence was low-to-moderate, mostly due to high risk of bias, low sample sizes, and wide variation in outcome measures. Future trials must be of higher quality, use agreed outcome measures, including measures other than walking speed, and examine the effects of FES for adults with cerebral palsy, traumatic and acquired brain injury, and Parkinson's disease.

Understanding the genetic mechanisms and cognitive impairments in Down syndrome: towards a holistic approach.

The most common genetic cause of intellectual disability is Down syndrome (DS), trisomy 21. It commonly results from three copies of human chromosome 21 (HC21). There are no mutations or deletions involved in DS. Instead, the phenotype is caused by altered transcription of the genes on HC21. These transcriptional variations are responsible for a myriad of symptoms affecting every organ system. A very debilitating aspect of DS is intellectual disability (ID). Although tremendous advances have been made to try and understand the underlying mechanisms of ID, there is a lack of a unified, holistic view to defining the cause and managing the cognitive impairments. In this literature review, we discuss the mechanisms of neuronal over-inhibition, abnormal morphology, and other genetic factors in contributing to the development of ID in DS patients and to gain a holistic understanding of ID in DS patients. We also highlight potential therapeutic approaches to improve the quality of life of DS patients.

PGE2 Potentiates Orai1-Mediated Calcium Entry Contributing to Peripheral Sensitization.

Peripheral sensitization is one of the primary mechanisms underlying the pathogenesis of chronic pain. However, candidate molecules involved in peripheral sensitization remain incompletely understood. We have shown that store-operated calcium channels (SOCs) are expressed in the dorsal root ganglion (DRG) neurons. Whether SOCs contribute to peripheral sensitization associated with chronic inflammatory pain is elusive. Here we report that global or conditional deletion of Orai1 attenuates Complete Freund's adjuvant (CFA)-induced pain hypersensitivity in both male and female mice. To further establish the role of Orai1 in inflammatory pain, we performed calcium imaging and patch-clamp recordings in wild-type (WT) and Orai1 knockout (KO) DRG neurons. We found that SOC function was significantly enhanced in WT but not in Orai1 KO DRG neurons from CFA- and carrageenan-injected mice. Interestingly, the Orai1 protein level in L3/4 DRGs was not altered under inflammatory conditions. To understand how Orai1 is modulated under inflammatory pain conditions, prostaglandin E2 (PGE2) was used to sensitize DRG neurons. PGE2-induced increase in neuronal excitability and pain hypersensitivity was significantly reduced in Orai1 KO mice. PGE2-induced potentiation of SOC entry (SOCE) was observed in WT, but not in Orai1 KO DRG neurons. This effect was attenuated by a PGE2 receptor 1 (EP1) antagonist and mimicked by an EP1 agonist. Inhibition of Gq/11, PKC, or ERK abolished PGE2-induced SOCE increase, indicating PGE2-induced SOCE enhancement is mediated by EP1-mediated downstream cascade. These findings demonstrate that Orai1 plays an important role in peripheral sensitization. Our study also provides new insight into molecular mechanisms underlying PGE2-induced modulation of inflammatory pain.Significance Statement Store-operated calcium channel (SOC) Orai1 is expressed and functional in dorsal root ganglion (DRG) neurons. Whether Orai1 contributes to peripheral sensitization is unclear. The present study demonstrates that Orai1-mediated SOC function is enhanced in DRG neurons under inflammatory conditions. Global and conditional deletion of Orai1 attenuates complete Freund's adjuvant (CFA)-induced pain hypersensitivity. We also demonstrate that prostaglandin E2 (PGE2) potentiates SOC function in DRG neurons through EP1-mediated signaling pathway. Importantly, we have found that Orai1 deficiency diminishes PGE2-induced SOC function increase and reduces PGE2-induced increase in neuronal excitability and pain hypersensitivity. These findings suggest that Orai1 plays an important role in peripheral sensitization associated with inflammatory pain. Our study reveals a novel mechanism underlying PGE2/EP1-induced peripheral sensitization. Orai1 may serve as a potential target for pathological pain.

Cytoprotective effects of Hangekobokuto against corticosterone-induced cell death in HT22 cells.

The hypothalamic-pituitary-adrenal (HPA) system plays an important role in stress response. Chronic stress is thought to induce neuronal damage and contribute to the pathogenesis of psychiatric disorders by causing dysfunction of the HPA system and promoting the production and release of glucocorticoids, including corticosterone and cortisol. Several clinical studies have demonstrated the efficacy of herbal medicines in treating psychiatric disorders; however, their effects on corticosterone-induced neuronal cell death remain unclear. Here, we used HT22 cells to evaluate the neuroprotective potential of herbal medicines used in neuropsychiatry against corticosterone-induced hippocampal neuronal cell death. Cell death was assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) reduction and Live/Dead assays. Hangekobokuto, Kamikihito, Saikokaryukotsuboreito, Kamishoyosan, and Yokukansan were supplied in the form of water-extracted dried powders. Exposure of HT22 cells to ≥ 100 µM corticosterone decreased MTT values. Exposure to 500 µM corticosterone alone reduced MTT values to 18%, while exposure to 10 µM Mifepristone (RU486)-a glucocorticoid receptor antagonist-restored values to 36%. Corticosterone-induced cell death was partially suppressed by treatment with RU486. At 100 µg/mL, Hangekobokuto significantly suppressed the decrease in MTT values (15-32%) and increase in the percentage of ethidium homodimer-1-positive dead cells caused by corticosterone exposure (78-36%), indicating an inhibitory effect on cell death. By contrast, Kamikihito, Saikokaryukotsuboreito, Kamishoyosan, and Yokukansan did not affect corticosterone-induced cell death. Therefore, our results suggest that Hangekobokuto may ameliorate the onset and progression of psychiatric disorders by suppressing neurological disorders associated with increased levels of glucocorticoids.

Neonatal di-(2-ethylhexyl)phthalate exposure induces permanent alterations in secretory CRH neuron characteristics in the hypothalamus paraventricular region of adult male rats.

Corticotrophin-releasing hormone (CRH) neurons in the hypothalamic paraventricular nucleus (PVN) play a critical role in the modulation of the hypothalamic-pituitary-adrenal (HPA) axis. Early-life exposure to di-(2-ethylhexyl) phthalate (DEHP) has been associated with an increased risk of developing psychiatric disorders in adulthood. The present work was designed to explore the impact of neonatal exposure to DEHP on adult PVN CRH neuronal activity. DEHP or vehicle was given to male rat pups from PND16 to PND22. Then, anxiety-like behaviors, serum corticosterone and testosterone, immunohistochemistry, western blotting, fluorescence in situ hybridization and acute ex vivo slice electrophysiological recordings were used to evaluate the influence of DEHP on adult PVN secretory CRH neurons. Neonatal DEHP-exposed rats exhibited enhanced anxiety-like behaviors in adults, with an increase in CORT. Secretory CRH neurons showed higher spontaneous firing activity but could be inhibited by GABAAR blockers. CRH neurons displayed fewer firing spikes, prolonged first-spike latency, depolarizing shifts in GABA reversal potential and strengthened GABAergic inputs, as indicated by increases in the frequency and amplitude of sIPSCs. Enhancement of GABAergic transmission was accompanied by upregulated expression of GAD67 and downregulated expression of GABABR1, KCC2 and GAT1. These findings suggest that neonatal exposure to DEHP permanently altered the characteristics of secretory CRH neurons in the PVN, which may contribute to the development of psychiatric disorders later in life.

Single-neuron analysis of axon arbors reveals distinct presynaptic organizations between feedforward and feedback projections.

The morphology and spatial distribution of axon arbors and boutons are crucial for neuron presynaptic functions. However, the principles governing their whole-brain organization at the single-neuron level remain unclear. We developed a machine-learning method to separate axon arbors from passing axons in single-neuron reconstruction from fluorescence micro-optical sectioning tomography imaging data and obtained 62,374 axon arbors that displayed distinct morphology, spatial patterns, and scaling laws dependent on neuron types and targeted brain areas. Focusing on the axon arbors in the thalamus and cortex, we revealed the segregated spatial distributions and distinct morphology but shared topographic gradients between feedforward and feedback projections. Furthermore, we uncovered an association between arbor complexity and microglia density. Finally, we found that the boutons on terminal arbors show branch-specific clustering with a log-normal distribution that again differed between feedforward and feedback terminal arbors. Together, our study revealed distinct presynaptic structural organizations underlying diverse functional innervation of single projection neurons.

Activation of neurons in the insular cortex and lateral hypothalamus during food anticipatory period caused by food restriction in mice.

Mice fed a single meal daily at a fixed time display food anticipatory activity (FAA). It has been reported that the insular cortex (IC) plays an essential role in food anticipation, and lateral hypothalamus (LH) regulates the expression of FAA. However, how these areas contribute to FAA production is still unclear. Thus, we examined the temporal and spatial activation pattern of neurons in the IC and LH during the food anticipation period to determine their role in FAA establishment. We observed an increase of c-Fos-positive neurons in the IC and LH, including orexin neurons of male adult C57BL/6 mice. These neurons were gradually activated from the 1st day to 15th day of restricted feeding. The activation of these brain regions, however, peaked at a distinct point in the food restriction procedure. These results suggest that the IC and LH are differently involved in the neural network for FAA production.