In hypoxic-ischemic brain damage (HIBD), the programmed cell death known as ferroptosis is significantly activated. Microglial cells demonstrate a high level of sensitivity to iron accumulation. Understanding how to regulate the dual role of microglia and transforming the microglial ferroptosis to a moderate and controllable process has considerable implications for the targeted treatment in HIBD. This paper serves as an overview of microglia-mediated ferroptosis in HIBD as a disease model. We discuss various aspects centered around microglia, including pathophysiological mechanisms, polarization and functions of microglia, molecular mechanisms of ferroptosis, signaling pathways, and therapeutic strategies. The review aims to provide a reference for studies of ferroptosis in microglia.
Microglia/physiology* ; Ferroptosis/physiology* ; Humans ; Animals ; Hypoxia-Ischemia, Brain/pathology* ; Signal Transduction

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*

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*

OBJECTIVES: To investigate whether human umbilical cord mesenchymal stem cells (HUC-MSCs) play protective effects against white matter injury (WMI) in neonatal rats via activation of the nuclear factor-erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)/heme oxygenase-1 (HO-1) signaling pathway. METHODS: A neonatal WMI model was established in 3-day-old Sprague-Dawley rats by unilateral common carotid artery ligation combined with hypoxia. The study comprised two parts. (1) Rats were randomized into sham, hypoxia-ischemia (HI), and HUC-MSC groups (n=36 per group); brain tissues were collected at 7, 14, and 21 days after modeling. (2) Rats were randomized into sham, HI, HUC-MSC, and HUC-MSC+ML385 (Nrf2 inhibitor) groups (n=12 per group); tissues were collected 14 days after modeling. Hematoxylin-eosin staining assessed histopathology, and Luxol fast blue staining evaluated myelination. Immunohistochemistry examined the localization and expression of Nrf2, myelin basic protein (MBP), and proteolipid protein (PLP). Immunofluorescence assessed synaptophysin (SYP) and postsynaptic density-95 (PSD-95). Western blotting quantified Nrf2, Keap1, HO-1, SYP, PSD-95, MBP, and PLP. Spatial learning and memory were evaluated by the Morris water maze. RESULTS: At 7, 14, and 21 days after modeling, the sham group showed intact white matter, whereas the HI group exhibited white matter disruption, cellular vacuolation, and disorganized nerve fibers. These pathological changes were attenuated in the HUC-MSC group. Compared with the HI group, the HUC-MSC group showed increased Nrf2 immunopositivity and protein levels, increased HO-1 protein levels, and decreased Keap1 protein levels (P<0.05). Compared with the HI group, the HUC-MSC group had higher SYP and PSD-95 immunofluorescence intensities and protein levels, higher MBP and PLP positivity and protein levels, increased mean optical density of myelin, more platform crossings, and longer time in the target quadrant (all P<0.05). These improvements were reduced in the HUC-MSC+ML385 group compared with the HUC-MSC group (P<0.05). CONCLUSIONS HUC-MSCs may promote oligodendrocyte maturation and synaptogenesis after neonatal WMI by activating the Nrf2/Keap1/HO-1 pathway, thereby improving spatial cognitive function.
NF-E2-Related Factor 2/physiology* ; Animals ; Rats, Sprague-Dawley ; Signal Transduction/physiology* ; Humans ; Rats ; White Matter/pathology* ; Kelch-Like ECH-Associated Protein 1/physiology* ; Umbilical Cord/cytology* ; Heme Oxygenase-1/physiology* ; Animals, Newborn ; Male ; Mesenchymal Stem Cell Transplantation ; Heme Oxygenase (Decyclizing)/physiology* ; Mesenchymal Stem Cells/physiology* ; Female ; Hypoxia-Ischemia, Brain

We describe an unusual case of hypoxic ischemic encephalopathy in a preterm female of 36 weeks who presented with status epilepticus and atypical abdominal myoclonus. The seizures were confirmed electrographically using video electroencephalography (EEG), while the abdominal myoclonus was demonstrated to be nonepileptic, as it had no EEG correlate. Other possible causes of neonatal seizures were excluded. The infant then responded to a gamut of antiseizure medications but the myoclonus persisted. To the best of our knowledge, this is the first report of atypical myoclonus in a preterm baby caused by hypoxic ischemic encephalopathy.

Hypoxic-ischemic brain damage (HIBD) is one of the main causes of disability in middle-aged and elderly people, as well as high mortality rates and long-term physical impairments in newborns. The pathological manifestations of HIBD include neuronal damage and loss of myelin sheaths. Tau protein is an important microtubule-associated protein in brain, exists in neurons and oligodendrocytes, and regulates various cellular activities such as cell differentiation and maturation, axonal transport, and maintenance of cellular cytoskeleton structure. Phosphorylation is a common chemical modification of Tau. In physiological condition, it maintains normal cell cytoskeleton and biological functions by regulating Tau structure and function. In pathological conditions, it leads to abnormal Tau phosphorylation and influences its structure and functions, resulting in Tauopathies. Studies have shown that brain hypoxia-ischemia could cause abnormal alteration in Tau phosphorylation, then participating in the pathological process of HIBD. Meanwhile, brain hypoxia-ischemia can induce oxidative stress and inflammation, and multiple Tau protein kinases are activated and involved in Tau abnormal phosphorylation. Therefore, exploring specific molecular mechanisms by which HIBD activates Tau protein kinases, and elucidating their relationship with abnormal Tau phosphorylation are crucial for future researches on HIBD related treatments. This review aims to focus on the mechanisms of the role of Tau phosphorylation in HIBD, and the potential relationships between Tau protein kinases and Tau phosphorylation, providing a basis for intervention and treatment of HIBD.
Humans ; tau Proteins/physiology* ; Phosphorylation ; Hypoxia-Ischemia, Brain/physiopathology* ; Animals ; Oxidative Stress

This study aims to explore whether Naoxintong Capsules improve multiple cerebral infarctions and myocardial injury via promoting angiogenesis, thereby exerting a simultaneous treatment effect on both the brain and heart. Male SD rats were randomly divided into six groups: sham-operated group, model group, high-dose, medium-dose, and low-dose groups of Naoxintong Capsules(440, 220, and 110 mg·kg~(-1)), and nimodipine group(10.8 mg·kg~(-1)). Rat models of multiple cerebral infarctions were established by injecting autologous thrombus, and samples were collected and tested seven days after modeling. Evaluations included multiple cerebral infarction model assessments, neurological function scores, grip strength tests, and rotarod tests, so as to evaluate neuromotor functions. Morphological structures of brain and heart tissue were observed using hematoxylin-eosin(HE) staining, Nissl staining, and Masson staining. Network pharmacology was employed to screen the mechanisms of Naoxintong Capsules in improving multiple cerebral infarctions and myocardial injury. Neuronal and myocardial cell ultrastructures were observed using transmission electron microscopy. Apoptosis rate in brain neuronal cells was detected by TdT-mediated dUTP nick end labeling(TUNEL) staining, and reactive oxygen species(ROS) levels in myocardial cells were measured. Immunofluorescence was used to detect the expression of platelet endothelial cell adhesion molecule-1(CD31), antigen identified by monoclonal antibody Ki67(Ki67), hematopoietic progenitor cell antigen CD34(CD34), and hypoxia inducible factor-1α(HIF-1α) in brain and myocardial tissue. Western blot, and real-time quantitative polymerase chain reaction(RT-qPCR) were used to detect the expression of HIF-1α, vascular endothelial growth factor(VEGF), vascular endothelial growth factor receptor 2(VEGFR2), sarcoma(Src), basic fibroblast growth factor(bFGF), angiopoietin-1(Ang-1), and TEK receptor tyrosine kinase(Tie-2). Compared with the model group, the medium-dose group of Naoxintong Capsules showed significantly lower neurological function scores, increased grip strength, and prolonged time on the rotarod. Pathological damage in brain and heart tissue was reduced, with increased and more orderly arranged mitochondria in neurons and cardiomyocytes. Apoptosis in brain neuronal cells was decreased, and ROS levels in cardiomyocytes were reduced. The microvascular density and endothelial cells of new blood vessels in brain and heart tissue increased, with increased overlapping regions of CD31 and Ki67 expression. The relative protein and mRNA expression levels of HIF-1α, VEGF, VEGFR2, Src, Ang-1, Tie-2, and bFGF were elevated in brain tissue and myocardial tissue. Naoxintong Capsules may improve multiple cerebral infarctions and myocardial injury by mediating HIF-1α/VEGF expression to promote angiogenesis.
Animals ; Male ; Drugs, Chinese Herbal/administration & dosage* ; Rats, Sprague-Dawley ; Rats ; Cerebral Infarction/genetics* ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics* ; Vascular Endothelial Growth Factor A/genetics* ; Capsules ; Signal Transduction/drug effects* ; Humans ; Brain/metabolism* ; Myocardium/metabolism* ; Apoptosis/drug effects*

OBJECTIVES: To evaluate the effect of eye acupuncture on neural function and angiogenesis of ischemic cerebral tissue in rats, and explore the roles of METTL3-mediated m⁶A methylation and the HIF-1α/VEGF-A signal axis in mediating this effect. METHODS: Fifty SD rats were randomized into normal control group, sham-operated group, model group, eye acupuncture group and DMOG (a HIF-1α agonist) group. Rat models of cerebral ischemia/reperfusion injury (CIRI) were established using a modified thread thrombus method, and the changes in neurological deficits of the rats after interventions were evaluated. TTC and Nissl staining were used to examine the changes in infarction size and neuronal injury, and cerebral angiogenesis was detected by double-immunofluorescence staining. m⁶A methylation modification level in the brain tissue was detected by ELISA, and RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of METTL3 and HIF-1α/VEGF-A. RESULTS: Compared with the control and sham-operated rats, the CIRI rats had significantly higher neurological deficit scores with larger cerebral infarction area, a greater number of CD31- and EDU-positive new vessels, higher expression levels of HIF-1α and VEGF-A, reduced number of Nissl bodies and m6A methylation level, and lowered METTL3 protein and mRNA expressions. All these changes were significantly improved by interventions with eye acupuncture after modeling or intraperitoneal injections of DMOG for 7 consecutive days prior to modeling, and the effects of the two interventions were similar. CONCLUSIONS Eye acupuncture can improve neurological deficits in CIRI rat models possibly by promoting cortical angiogenesis via upregulating METTL3-mediated m⁶A methylation and regulating the HIF-1α/VEGF-A signal axis.
Animals ; Rats, Sprague-Dawley ; Methyltransferases/metabolism* ; Reperfusion Injury/physiopathology* ; Methylation ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Rats ; Vascular Endothelial Growth Factor A/metabolism* ; Brain Ischemia/metabolism* ; Acupuncture Therapy ; Male ; Up-Regulation ; Neovascularization, Physiologic ; Angiogenesis ; Adenosine/analogs & derivatives*

OBJECTIVES: To investigate the effects of Naoluo Xintong Decoction (NLXTD) on proliferation of rat brain microvascular endothelial cells (BMECs) after oxygen-glucose deprivation/reoxygenation (OGD/R) injury and role of the HIF-1α/VEGF pathway in mediating its effect. METHODS: Using a BMEC model of OGD/R, we tested the effects of 10% NLXTD-medicated rat serum, alone or in combination with 2ME2 or 10% NAKL, on cell proliferation, migration, tube-forming ability and permeability using CCK-8 assay, Transwell chamber assay, tube formation assay and permeability assay. Cellular expressions of VEGF and Notch were detected using ELISA and laser confocal immunofluorescence analysis, and the expressions of HIF-1α, VEGFR2, Notch1, ERK and P-ERK1/2 proteins were detected with Western blotting. RESULTS: OGD/R injury significantly decreased viability of BMECs. NLXTD treatment of the cells with OGD/R could significantly promoted cell proliferation, migration and tube formation ability, but these effects were strongly attenuated by application of 2ME2. NLXTD treatment also significantly increased the percentages of VEGF- and Notch-positive cells in the cell models and obviously enhanced the expression levels of HIF-1α, VEGFR2, Notch1 and P-ERK1/2. CONCLUSIONS NLXTD promotes proliferation, migration, and tube formation of rat BMECs after OGD/R injury possibly by activating the HIF-1α/VEGF signaling pathway.
Animals ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Drugs, Chinese Herbal/pharmacology* ; Vascular Endothelial Growth Factor A/metabolism* ; Endothelial Cells/metabolism* ; Rats ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects* ; Glucose ; Brain/blood supply* ; Cells, Cultured ; Rats, Sprague-Dawley ; Vascular Endothelial Growth Factor Receptor-2/metabolism* ; Oxygen/metabolism* ; Cell Hypoxia

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*