OBJECTIVES: To observe the therapeutic effect of spermine in neonatal mouse models of severe hand, foot and mouth disease (HFMD) caused by enterovirus 71 (EV71) infection and explore its therapeutic mechanism in light of regulation of macrophage GBP5/NLRP3 inflammasome pathway. METHODS: Neonatal BALB/c mice (3-5 days old) were divided into control group, EV71 infection group and Spermine treatment group. The mice in the latter two groups received an intraperitoneal injection of 50 μL EV71 suspension (1×10⁶ TCID50 of EV71), followed 3 days later by intraperitoneal injection of 50 μL PBS or 100 μmol/L spermine. GBP5, NLRP3, CXCL10, and TNFSF10 expressions in heart, liver, lung and kidney tissues of the mice were detected using Western blotting and qPCR, and tissue pathologies and macrophage infiltration were assessed with HE staining and immunohistochemistry. In cultured THP-1 and RAW264.7 cells, the effects of EV71 infection, GBP5 siRNA transfection and treatment with spermine or eflornithine on GBP5, NLRP3, CXCL10, and TNFSF10 mRNA expressions were investigated using qPCR. RESULTS: In the neonatal mice, EV71 infection resulted in multiple organ damage, macrophage infiltration and activation of the GBP5/NLRP3 pathway, and spermine treatment significantly improved tissue injuries, reduced macrophage infiltration, and down-regulated the expressions of GBP5, NLRP3 and the inflammatory factors in the infected mice. In THP-1 and RAW264.7 cells, EV71 infection caused significant upregulation of GBP5, NLRP3, CXCL10, and TNFSF10 expressions, which were obviously lowered by spermine treatment. In THP-1 cells, treatment with eflornithine significantly suppressed the reduction of GBP5, NLRP3, CXCL10, and TNFSF10 expressions induced by GBP5 siRNA transfection. CONCLUSIONS Spermine suppressed EV71 infection-induced inflammatory responses by inhibiting GBP5-mediated NLRP3 inflammasome activation, suggesting a new strategy for treatment of severe HFMD.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein ; Mice ; Macrophages/metabolism* ; Enterovirus A, Human ; Mice, Inbred BALB C ; Inflammasomes/metabolism* ; Spermine/therapeutic use* ; Animals, Newborn ; Humans ; Enterovirus Infections ; Hand, Foot and Mouth Disease/drug therapy* ; RAW 264.7 Cells ; Chemokine CXCL10/metabolism*

OBJECTIVES: To investigate the effect of orexin-A-mediated regulation of ionotropic glutamate receptors for promoting motor function recovery in rats with spinal cord injury (SCI). METHODS: Thirty-six newborn SD rats (aged 7-14 days) were randomized into 6 groups (n=6), including a normal control group, a sham-operated group, and 4 SCI groups with daily intrathecal injection of saline, DNQX, orexin-A, or orexin-A+DNQX for 3 consecutive days after PCI. Motor function of the rats were evaluated using blood-brain barrier (BBB) score and inclined plane test 1 day before and at 1, 3, and 7 days after SCI. For patch-clamp experiment, spinal cord slices from newborn rats in the control, sham-operated, SCI, and SCI+orexin groups were prepared, and ventral horn neurons were acutely isolated to determine the reversal potential and dynamic indicators of glutamate receptor-mediated currents under glutamate perfusion. RESULTS: At 3 and 7 days after SCI, the orexin-A-treated rats showed significantly higher BBB scores and grip tilt angles than those with other interventions. Compared with those treated with DNQX alone, the rats receiving the combined treatment with orexin and DNQX had significantly higher BBB scores and grip tilt angles on day 7 after PCI. In the patch-clamp experiment, the ventral horn neurons from SCI rat models exhibited obviously higher reversal potential and greater rise slope of glutamate current with shorter decay time than those from sham-operated and orexin-treated rats. CONCLUSIONS Orexin-A promotes motor function recovery in rats after SCI possibly by improving the function of the ionotropic glutamate receptors.
Animals ; Spinal Cord Injuries/drug therapy* ; Rats ; Rats, Sprague-Dawley ; Receptors, Ionotropic Glutamate/metabolism* ; Recovery of Function/drug effects* ; Orexins/pharmacology* ; Male ; Female ; Animals, Newborn ; Neuropeptides/pharmacology* ; Intracellular Signaling Peptides and Proteins/pharmacology*

OBJECTIVES: To evaluate the therapeutic effect of gastrodin against hypoxic-ischemic brain damage (HIBD) in neonatal mice and explore the role of GPX4/SLC7A11/FTH1 signaling in mediating its effect. METHODS: Twenty-four 9- to 11-day-old C57BL/6J mice were randomized equally into 4 groups for sham operation, HIBD modeling by right common carotid artery ligation and subsequent exposure to hypoxia for 1 h, or gastrodin treatment at 100 or 200 mg/kg before and at 1 and 2 days after modeling. The mice then underwent neurological assessment (Zea-Longa scores), and the cerebral cortical penumbra tissue were collected for HE and Nissl staining, detection of ferroptosis biomarkers and protein expressions of GPX4, SLC7A11, and FTH1 with Western blotting and immunofluorescence co-localization, and observation of mitochondrial ultrastructure with electron microscopy. In cultured HT22 neuronal cells with oxygen-glucose deprivation (OGD) for 2 h, the effects of pretreatments with 0.5 mmol/L gastrodin, 10 μmol/L RSL3 (a GPX4 inhibitor), alone or in combination, were analyzed on expressions of ferroptosis-related proteins, cellular Fe²⁺, ROS, lipid peroxidation, MDA, and GSH levels, mitochondrial membrane potential (JC-1), and cell viability. RESULTS: Gastrodin treatment at the two doses both significantly ameliorated HIBD and neurological deficits of the mice, reduced mitochondrial damage and Fe²⁺, MDA and ROS levels, increased GSH level, and upregulated GPX4, SLC7A11, and FTH1 protein expressions. In HT22 cells, gastrodin pretreatment obviously attenuated OGD-induced ferroptosis and improved cell viability and mitochondrial function. Co-treatment with RSL3 potently abrogated the inhibitory effects of gastrodin on Fe²⁺, ROS, BODIPY-C11, and MDA levels and attenuated its protective effects on GSH level, cell viability, and mitochondrial membrane potential. CONCLUSIONS Gastrodin provides neuroprotective effects in neonatal mice with HIBD by suppressing neuronal ferroptosis via upregulating the GPX4/SLC7A11/FTH1 signaling pathway.
Animals ; Ferroptosis/drug effects* ; Hypoxia-Ischemia, Brain/drug therapy* ; Mice ; Mice, Inbred C57BL ; Signal Transduction/drug effects* ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Glucosides/pharmacology* ; Animals, Newborn ; Benzyl Alcohols/pharmacology* ; Amino Acid Transport System y+/metabolism*

The oxytocin receptor (OXTR) has garnered increasing attention for its role in regulating both mature behaviors and brain development. It has been established that OXTR mediates a range of effects that are region-specific or period-specific. However, the current studies of OXTR expression patterns in mice only provide limited help due to limitations in resolution. Therefore, our objective was to generate a comprehensive, high-resolution spatiotemporal expression map of Oxtr mRNA across the entire developing mouse brain. We applied RNAscope in situ hybridization to investigate the spatiotemporal expression pattern of Oxtr in the brains of male mice at six distinct postnatal developmental stages (P7, P14, P21, P28, P42, P56). We provide detailed descriptions of Oxtr expression patterns in key brain regions, including the cortex, basal forebrain, hippocampus, and amygdaloid complex, with a focus on the precise localization of Oxtr⁺ cells and the variance of expression between different neurons. Furthermore, we identified some neuronal populations with high Oxtr expression levels that have been little studied, including glutamatergic neurons in the ventral dentate gyrus, Vgat⁺Oxtr⁺ cells in the basal forebrain, and GABAergic neurons in layers 4/5 of the cortex. Our study provides a novel perspective for understanding the distribution of Oxtr and encourages further investigations into its functions.
Animals ; Receptors, Oxytocin/metabolism* ; Male ; Brain/growth & development* ; Mice ; Mice, Inbred C57BL ; Neurons/metabolism* ; Single-Cell Analysis ; Gene Expression Regulation, Developmental ; RNA, Messenger/metabolism* ; Animals, Newborn

Hypoxic-ischemic (HI) brain damage poses a high risk of death or lifelong disability, yet effective treatments remain elusive. Here, we demonstrated that miR-100-5p levels in the lesioned cortex increased after HI insult in neonatal mice. Knockdown of miR-100-5p expression in the brain attenuated brain injury and promoted functional recovery, through inhibiting the cleaved-caspase-3 level, microglia activation, and the release of proinflammation cytokines following HI injury. Engineered extracellular vesicles (EVs) containing neuron-targeting rabies virus glycoprotein (RVG) and miR-100-5p antagonists (RVG-EVs-Antagomir) selectively targeted brain lesions and reduced miR-100-5p levels after intranasal delivery. Both pre- and post-HI administration showed therapeutic benefits. Mechanistically, we identified protein phosphatase 3 catalytic subunit alpha (Ppp3ca) as a novel candidate target gene of miR-100-5p, inhibiting c-Fos expression and neuronal apoptosis following HI insult. In conclusion, our non-invasive method using engineered EVs to deliver miR-100-5p antagomirs to the brain significantly improves functional recovery after HI injury by targeting Ppp3ca to suppress neuronal apoptosis.
Animals ; MicroRNAs/metabolism* ; Extracellular Vesicles/metabolism* ; Mice ; Recovery of Function/physiology* ; Hypoxia-Ischemia, Brain/therapy* ; Mice, Inbred C57BL ; Antagomirs/administration & dosage* ; Male ; Animals, Newborn ; Apoptosis/drug effects* ; Brain Injuries/metabolism* ; Glycoproteins ; Peptide Fragments ; Viral Proteins

Necrotizing enterocolitis (NEC) is an intestinal inflammatory and necrotic disease seen in premature infants, and remains the leading cause of death resulted from gastrointestinal diseases in premature infants. The specific pathogenesis of NEC is still unclear. In recent years, a lot of studies have reported that Toll-like receptor 4 (TLR4) plays a key role in the pathogenesis of NEC. TLR4, which is abundantly expressed in intestinal epithelial cells of premature infants, binds to bacterial lipopolysaccharide (LPS) to activate downstream signaling pathways, leading to disruption of intestinal epithelial integrity and bacterial translocation, resulting in intestinal ischemic necrosis and inflammatory responses, which may rapidly progress to severe sepsis, multiple organ dysfunction, and death. This paper reviews the mechanism of TLR4-related signaling pathways in intestinal epithelial injury and inflammatory responses in newborns with NEC, providing a reference to study new therapeutic targets for NEC.
Enterocolitis, Necrotizing/pathology* ; Toll-Like Receptor 4/metabolism* ; Humans ; Infant, Newborn ; Signal Transduction ; Inflammation/metabolism* ; Animals ; Intestines/immunology* ; Intestinal Mucosa/pathology* ; Infant, Premature

OBJECTIVES: To evaluate preterm white matter injury (PWMI) in neonatal rats using multimodal magnetic resonance imaging (MRI) combined with histological assessments and to explore its underlying mechanisms. METHODS: Healthy 3-day-old Sprague-Dawley neonatal rats were randomly divided into a sham operation group and a PWMI group (n=12 in each group). A PWMI model was established in neonatal rats through hypoxia-ischemia. Laser speckle imaging was used to observe changes in cerebral oxygen saturation and blood flow at different time points post-modeling. Multimodal MRI was employed to assess the condition of white matter injury, while hematoxylin-eosin staining was utilized to observe morphological changes in the striatal area on the injured side. Immunofluorescence staining was performed to detect the proliferation and differentiation of oligodendrocyte precursor cells. RESULTS: At 0, 6, 12, 24, and 72 hours post-modeling, the relative blood flow and relative oxygen saturation on the injured side in the PWMI group were significantly lower than those in the sham operation group (P<0.05). At 24 hours post-modeling, T2-weighted imaging showed high signals in the white matter of the injured side in the PWMI group, with relative apparent diffusion coefficient values and Lorenz differential values being lower than those in the sham operation group (P<0.001); additionally, the arrangement of nerve cells in the PWMI group was disordered, and the number of EdU⁺PDGFR-α⁺ cells was higher than that in the sham operation group (P<0.001). At 28 days post-modeling, the relative fractional anisotropy values, the number of EdU⁺Olig2⁺ cells, and the fluorescence intensity of myelin basic protein and neurofilament protein 200 in the white matter region of the PWMI group were all lower than those in the sham operation group (P<0.001). CONCLUSIONS Multimodal MRI can evaluate early and long-term changes in PWMI in neonatal rat models in vivo, providing both imaging and pathological evidence for the diagnosis and treatment of PWMI in neonates. Hypoxia-ischemia inhibits the proliferation and differentiation of oligodendrocyte precursor cells in neonatal rats, leading to PWMI.
Animals ; Rats, Sprague-Dawley ; Magnetic Resonance Imaging/methods* ; Rats ; White Matter/injuries* ; Animals, Newborn ; Female ; Multimodal Imaging ; Male ; Hypoxia-Ischemia, Brain/pathology*

White matter injury (WMI) is a major form of brain injury in preterm infants. Its characteristic pathological features primarily involve impaired development of oligodendrocyte precursor cells and structural damage to axons, which can lead to the neurological sequelae such as motor, behavioral, and cognitive dysfunctions. Chondroitin sulfate proteoglycans (CSPGs), as the important components of extracellular matrix, can participate in neuroinflammatory response mediated by microglial cells and dynamically balance glial scar reconstruction and axon growth by regulating specific receptors and signaling pathways. This article reviews the relationship between CSPGs and WMI, as well as the mechanisms by which CSPGs inhibit axon growth, focusing on the role of multi-target regulation of CSPGs in promoting axon plasticity and functional brain recovery, thereby providing a theoretical basis for improving the prognosis of preterm infants with WMI.
Humans ; Chondroitin Sulfate Proteoglycans/physiology* ; White Matter/pathology* ; Axons/physiology* ; Infant, Premature ; Infant, Newborn ; Animals

OBJECTIVES: To investigate the effects of hyperoxia on the expression of N-methyl-D-aspartate receptor 1 (NMDAR1) and its synapse-associated molecules, including cannabinoid receptor 1 (CB1R), postsynaptic density 95 (PSD95), and synapsin (SYN), in the hippocampus of neonatal rats. METHODS: One-day-old Sprague-Dawley neonatal rats were randomly divided into a hyperoxia group and a control group (n=8 per group). The hyperoxia group was exposed to 80% ± 5% oxygen continuously, while the control group was exposed to room air, for 7 days. At 1, 3, and 7 days after hyperoxia exposure, hematoxylin and eosin (HE) staining was used to observe histopathological changes in the brain. The expression levels of NMDAR1, CB1R, PSD95, and SYN proteins and mRNAs in the hippocampus were detected by immunohistochemistry, Western blotting, and quantitative real-time PCR. RESULTS: After 7 days of hyperoxia exposure, the hyperoxia group showed decreased neuronal density and disordered arrangement in brain tissue. Compared with the control group, after 1 day of hyperoxia exposure, CB1R mRNA and both NMDAR1 and CB1R protein expression in the hyperoxia group were significantly downregulated, while SYN protein expression was significantly upregulated (P<0.05). After 3 days, mRNA expression of NMDAR1, CB1R, and SYN was significantly decreased (P<0.05); NMDAR1 and CB1R protein expression was significantly downregulated (P<0.05), while PSD95 and SYN protein expression was significantly upregulated (P<0.05). After 7 days of hyperoxia, the protein expression of NMDAR1 and CB1R was significantly upregulated (P<0.05). CONCLUSIONS Continuous hyperoxia exposure induces time-dependent changes in the expression levels of NMDAR1 and its synapse-associated molecules in the hippocampus of neonatal rats.
Animals ; Receptors, N-Methyl-D-Aspartate/genetics* ; Rats, Sprague-Dawley ; Hippocampus/pathology* ; Rats ; Animals, Newborn ; Receptor, Cannabinoid, CB1/genetics* ; Hyperoxia/metabolism* ; Disks Large Homolog 4 Protein/genetics* ; Synapsins/genetics* ; Synapses ; Male ; Female ; RNA, Messenger/analysis*

OBJECTIVES: To investigate whether mesenchymal stem cell-derived exosomes (MSC-Exo) alleviate white matter damage (WMD) in neonatal rats by targeting the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3). METHODS: Three-day-old Sprague-Dawley rats were randomly assigned to four groups: Sham, hypoxia-ischemia (HI), MSC-Exo, and MCC950 (NLRP3 inhibitor) (n=24 per group). The WMD model was established by unilateral common carotid artery ligation combined with hypoxia. Exosomes (1×10⁸ particles/μL) were transplanted into the lateral ventricle using stereotaxic guidance. Fourteen days after modeling, hematoxylin-eosin staining was used to observe pathological changes in brain tissue, and transmission electron microscopy was used to assess myelinated axons. Western blotting was performed to detect the expression of myelin basic protein (MBP), NLRP3, caspase-1, and interleukin-1β (IL-1β). Immunohistochemistry was used to measure NLRP3, caspase-1, and IL-1β expression. Twenty-eight days post-modeling, behavioral changes were evaluated using the Morris water maze. RESULTS: In the HI group, marked inflammatory cell infiltration, extensive vacuolation, and decreased numbers of myelinated axons were observed compared to the Sham group. The MSC-Exo group showed reduced inflammatory infiltration, fewer vacuoles, and increased myelinated axons compared to the HI group, while the MCC950 group showed nearly normal cell morphology. Compared to the Sham group, the HI group exhibited decreased MBP expression, fewer platform crossings, shorter time in the target quadrant, increased expression of NLRP3, caspase-1, and IL-1β, and longer escape latency (all P<0.05). Compared to the HI group, the MSC-Exo and MCC950 groups showed increased MBP expression, more platform crossings, longer target quadrant stay, and reduced NLRP3, caspase-1, and IL-1β expression, as well as shorter escape latency (all P<0.05). CONCLUSIONS MSC-Exo may attenuate white matter damage in neonatal rats by targeting the NLRP3 inflammasome and promoting oligodendrocyte maturation.
Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/antagonists & inhibitors* ; Rats, Sprague-Dawley ; White Matter/pathology* ; Inflammasomes/physiology* ; Rats ; Animals, Newborn ; Mesenchymal Stem Cells ; Interleukin-1beta/analysis* ; Male ; Caspase 1/analysis* ; Hypoxia-Ischemia, Brain/therapy* ; Myelin Basic Protein/analysis*