Interactions between brain-resident and peripheral infiltrated immune cells are thought to contribute to neuroplasticity after cerebral ischemia. However, conventional bulk sequencing makes it challenging to depict this complex immune network. Using single-cell RNA sequencing, we mapped compositional and transcriptional features of peri-infarct immune cells. Microglia were the predominant cell type in the peri-infarct region, displaying a more diverse activation pattern than the typical pro- and anti-inflammatory state, with axon tract-associated microglia (ATMs) being associated with neuronal regeneration. Trajectory inference suggested that infiltrated monocyte-derived macrophages (MDMs) exhibited a gradual fate trajectory transition to activated MDMs. Inter-cellular crosstalk between MDMs and microglia orchestrated anti-inflammatory and repair-promoting microglia phenotypes and promoted post-stroke neurogenesis, with SOX2 and related Akt/CREB signaling as the underlying mechanisms. This description of the brain's immune landscape and its relationship with neurogenesis provides new insight into promoting neural repair by regulating neuroinflammatory responses.
Humans ; Ischemic Stroke ; Brain/metabolism* ; Macrophages ; Brain Ischemia/metabolism* ; Microglia/metabolism* ; Gene Expression Profiling ; Anti-Inflammatory Agents ; Neuronal Plasticity/physiology* ; Infarction/metabolism*

To explore the effect and mechanism of Zuogui Pills in promoting neural tissue recovery and functional recovery in mice with ischemic stroke. Male C57BL/6J mice were randomly divided into a sham group, a model group, and low-, medium, and high-dose Zuogui Pills groups(3.5, 7, and 14 g·kg~(-1)), with 15 mice in each group. The ischemic stroke model was established using photochemical embolization. Stiker remove and irregular ladder walking behavioral tests were conducted before modeling and on days 7, 14, 21, and 28 after medication. Triphenyl tetrazolium chloride(TTC) staining was performed on day 3 after modeling, and T2-weighted imaging(T2WI) and diffusion-weighted imaging(DWI) were performed on day 28 after medication to evaluate the extent of brain injury. Hematoxylin-eosin(HE) staining was performed to observe the histology of the cerebral cortex. Axonal marker proteins myelin basic protein(MBP), growth-associated protein 43(GAP43), mammalian target of rapamycin(mTOR), and its downstream phosphorylated s6 ribosomal protein(p-S6), as well as mechanism-related proteins osteopontin(OPN) and insulin-like growth factor 1(IGF-1), were detected using immunofluorescence and Western blot. Zuogui Pills had a certain restorative effect on the neural function impairment caused by ischemic stroke in mice. TTC staining showed white infarct foci in the sensory-motor cortex area, and T2WI imaging revealed cystic necrosis in the sensory-motor cortex area. The Zuogui Pills groups showed less brain tissue damage, fewer scars, and more capillaries. The number of neuronal axons in those groups was higher than that in the model group, and neuronal activity was stronger. The expression of GAP43, OPN, IGF-1, and mTOR proteins in the Zuogui Pills groups was higher than that in the model group. In summary, Zuogui Pills can promote the recovery of neural function and axonal growth in mice with ischemic stroke, and its mechanism may be related to the activation of the OPN/IGF-1/mTOR signaling pathway.
Mice ; Animals ; Male ; Ischemic Stroke ; Recovery of Function/physiology* ; Insulin-Like Growth Factor I/pharmacology* ; Mice, Inbred C57BL ; TOR Serine-Threonine Kinases/metabolism* ; Stroke/drug therapy* ; Brain Ischemia/drug therapy* ; Mammals/metabolism*

This study investigated the effect of Xiaoxuming Decoction(XXMD) on the activation of astrocytes after cerebral ischemia/reperfusion(I/R) injury. The model of cerebral IR injury was established using the middle cerebral artery occlusion method. Fluorocitrate(FC), an inhibitor of astrocyte activation, was applied to inhibit astrocyte activation. Rats were randomly divided into a sham group, a model group, a XXMD group, a XXMD+FC group, and a XXMD+Vehicle group. Neurobehavioral changes at 24 hours after cerebral IR injury, cerebral infarction, histopathological changes observed through HE staining, submicroscopic structure of astrocytes observed through transmission electron microscopy, fluorescence intensity of glial fibrillary acidic protein(GFAP) and thrombospondin 1(TSP1) measured through immunofluorescence, and expression of GFAP and TSP1 in brain tissue measured through Western blot were evaluated in rats from each group. The experimental results showed that neurobehavioral scores and cerebral infarct area significantly increased in the model group. The XXMD group, the XXMD+FC group, and the XXMD+Vehicle group all alleviated neurobehavioral changes in rats. The pathological changes in the brain were evident in the model group, while the XXMD group, the XXMD+FC group, and the XXMD+Vehicle group exhibited milder cerebral IR injury in rats. The submicroscopic structure of astrocytes in the model group showed significant swelling, whereas the XXMD group, the XXMD+FC group, and XXMD+Vehicle group protected the submicroscopic structure of astrocytes. The fluorescence intensity and protein expression of GFAP and TSP1 increased in the model group compared with those in the sham group. However, the XXMD group, the XXMD+FC group, and XXMD+Vehicle group all down-regulated the expression of GFAP and TSP1. The combination of XXMD and FC showed a more pronounced effect. These results indicate that XXMD can improve cerebral IR injury, possibly by inhibiting astrocyte activation and down-regulating the expression of GFAP and TSP1.
Rats ; Animals ; Astrocytes ; Brain Ischemia/metabolism* ; Brain ; Reperfusion Injury/metabolism* ; Infarction, Middle Cerebral Artery

This study investigated the neuroprotective effects and underlying mechanism of Liujing Toutong Tablets(LJTT) on a rat model of permanent middle cerebral artery occlusion(pMCAO). The pMCAO model was established using the suture method. Eighty-four male SPF-grade SD rats were randomly divided into a sham operation group, a model group, a nimodipine group(0.020 g·kg~(-1)), and high-, medium-, and low-dose LJTT groups(2.8, 1.4, and 0.7 g·kg~(-1)). The Longa score, adhesive removal test and laser speckle contrast imaging technique were used to evaluate the degree of neurological functional impairment and changes in local cerebral blood flow. The survival and mortality of rats in each group were recorded daily. After seven days of continuous administration following the model induction, the rats in each group were euthanized, and brain tissue and blood samples were collected for corresponding parameter measurements. Nissl staining was used to examine pathological changes in brain tissue neurons. The levels of tumor necrosis factor-alpha(TNF-α), interleukin-6(IL-6), IL-1β, vascular endothelial growth factor(VEGF), calcitonin gene-related peptide(CGRP), beta-endorphin(β-EP), and endogenous nitric oxide(NO) in rat serum were measured using specific assay kits. The entropy weight method was used to analyze the weights of various indicators. The protein expression levels of nuclear factor kappa-B(NF-κB), inhibitor kappaB alpha(IκBα), phosphorylated IκBα(p-IκBα), and phosphorylated inhibitor of NF-κB kinase alpha(p-IKKα) in brain tissue were determined using Western blot. Immunohistochemistry was used to detect the protein expression of chemokine-like factor 1(CKLF1) and C-C chemokine receptor 5(CCR5) in rat brain tissue. Compared with the sham operation group, the model group showed significantly higher neurological functional impairment scores, prolonged adhesive removal time, decreased cerebral blood flow, increased neuronal damage, reduced survival rate, significantly increased levels of TNF-α, IL-1β, IL-6, CGRP, and NO in serum, significantly decreased levels of VEGF and β-EP, significantly increased expression levels of NF-κB p65, p-IκBα/IκBα, and p-IKKα in rat brain tissue, and significantly upregulated protein expression of CKLF1 and CCR5. Compared with the model group, the high-dose LJTT group significantly improved the neurological functional score of pMCAO rats after oral administration for 7 days. LJTT at all doses significantly reduced adhesive removal time and restored cerebral blood flow. The high-and medium-dose LJTT groups significantly improved neuronal damage. The LJTT groups at all doses showed reduced levels of TNF-α, IL-1β, IL-6, CGRP, and NO in rat serum, increased VEGF and β-EP levels, and significantly decreased expression levels of NF-κB p65, p-IκBα/IκBα, p-IKKα, and CCR5 protein in rat brain tissue. The entropy weight analysis revealed that CGRP and β-EP were significantly affected during the model induction, and LJTT exhibited a strong effect in reducing the release of inflammatory factors such as TNF-α and IL-1β. LJTT may exert a neuroprotective effect on rats with permanent cerebral ischemia by reducing neuroinflammatory damage, and its mechanism may be related to the inhibition of the NF-κB signaling pathway and the regulation of the CKLF1/CCR5 axis. Additionally, LJTT may exert certain analgesic effects by reducing CGRP and NO levels and increasing β-EP levels.
Rats ; Male ; Animals ; NF-kappa B/metabolism* ; NF-KappaB Inhibitor alpha/metabolism* ; Vascular Endothelial Growth Factor A/genetics* ; I-kappa B Kinase/pharmacology* ; Tumor Necrosis Factor-alpha/pharmacology* ; Interleukin-6/genetics* ; Calcitonin Gene-Related Peptide/pharmacology* ; Rats, Sprague-Dawley ; Signal Transduction ; Brain Ischemia/drug therapy* ; Tablets

Vascular dementia(VD) is a condition of cognitive impairment due to acute and chronic cerebral hypoperfusion. The available therapies for VD mainly focus on mitigating cerebral ischemia, improving cognitive function, and controlling mental behavior. Achievements have been made in the basic and clinical research on the treatment of VD with traditional Chinese medicine(TCM) active components, including Ginkgo leaf extract, puerarin, epimedium, tanshinone, and ginsenoside. Most of these components have anti-inflammatory, anti-apoptotic, anti-oxidant, and neuroprotective effects, and puerarin demonstrates excellent performance in mitigating cholinergic nervous system disorders and improving synaptic plasticity. Puerarin, ginkgetin, and epimedium are all flavonoids, while tanshinone is a diterpenoid. Puerariae Lobatae Radix, pungent in nature, can induce clear Yang to reach the cerebral orifices and has the wind medicine functions of ascending, dispersing, moving, and scurrying. Puerariae Lobatae Radix entering collaterals will dredge blood vessels to promote blood flow, and that entering the sweat pore will open the mind, which is in line with the TCM pathogenesis characteristics of VD. This study reviews the progress in the mechanism of puerarin, the main active component of Puerariae Lobatae Radix, in treating VD. Puerarin can ameliorate cholinergic nervous system disorders, reduce excitotoxicity, anti-inflammation, inhibit apoptosis, alleviate oxidative stress injury, enhance synaptic plasticity, up-regulate neuroprotective factor expression, promote cerebral circulation metabolism, and mitigate Aβ injury. The pathways of action include activating nuclear factor erythroid 2-related factor 2(Nrf2)/antioxidant response element(ARE), vascular endothelial growth factor(VEGF), extracellular regulated protein kinases(ERK), phosphatidylinositol-3-kinase(PI3K)/protein kinase B(Akt), Janus-activating kinase 2(JAK2)/signal transducer and activator of transcription 3(STAT3), AMP-activated protein kinase(AMPK), as well as inhibiting the tumor necrosis factor α(TNF-α), transient receptor potential melastatin 2(TRPM2)/N-methyl-D-aspartate receptor(NMDAR), p38 mitogen-activated protein kinase(p38 MAPK), Toll-like receptor 4(TLR4)/nuclear factor-kappaB(NF-κB), early growth response 1(Egr-1), and matrix metalloproteinase 9(MMP-9). By reviewing the papers about the treatment of VD by puerarin published by CNKI, Wanfang, VIP, PubMed, and Web of Science in the last 10 years, this study aims to support the treatment and drug development for VD.
Humans ; Dementia, Vascular/drug therapy* ; Vascular Endothelial Growth Factor A ; NF-kappa B/metabolism* ; Antioxidants ; Brain Ischemia ; Cholinergic Agents

Ischemic stroke is a major public health problem worldwide. Although the circadian clock is involved in the process of ischemic stroke, the exact mechanism of the circadian clock in regulating angiogenesis after cerebral infarction remains unclear. In the present study, we determined that environmental circadian disruption (ECD) increased the stroke severity and impaired angiogenesis in the rat middle cerebral artery occlusion model, by measuring the infarct volume, neurological tests, and angiogenesis-related protein. We further report that Bmal1 plays an irreplaceable role in angiogenesis. Overexpression of Bmal1 promoted tube-forming, migration, and wound healing, and upregulated the vascular endothelial growth factor (VEGF) and Notch pathway protein levels. This promoting effect was reversed by the Notch pathway inhibitor DAPT, according to the results of angiogenesis capacity and VEGF pathway protein level. In conclusion, our study reveals the intervention of ECD in angiogenesis in ischemic stroke and further identifies the exact mechanism by which Bmal1 regulates angiogenesis through the VEGF-Notch1 pathway.
Rats ; Animals ; Vascular Endothelial Growth Factor A/pharmacology* ; Brain Ischemia/metabolism* ; Ischemic Stroke ; Signal Transduction ; ARNTL Transcription Factors/pharmacology* ; Neovascularization, Physiologic/physiology*

Chronic cerebral hypoperfusion leads to white matter injury (WMI), which subsequently causes neurodegeneration and even cognitive impairment. However, due to the lack of treatment specifically for WMI, novel recognized and effective therapeutic strategies are urgently needed. In this study, we found that honokiol and magnolol, two compounds derived from Magnolia officinalis, significantly facilitated the differentiation of primary oligodendrocyte precursor cells (OPCs) into mature oligodendrocytes, with a more prominent effect of the former compound. Moreover, our results demonstrated that honokiol treatment improved myelin injury, induced mature oligodendrocyte protein expression, attenuated cognitive decline, promoted oligodendrocyte regeneration, and inhibited astrocytic activation in the bilateral carotid artery stenosis model. Mechanistically, honokiol increased the phosphorylation of serine/threonine kinase (Akt) and mammalian target of rapamycin (mTOR) by activating cannabinoid receptor 1 during OPC differentiation. Collectively, our study indicates that honokiol might serve as a potential treatment for WMI in chronic cerebral ischemia.
Magnolia ; White Matter ; Brain Ischemia/metabolism* ; Oligodendroglia/metabolism*

OBJECTIVES: To study the effect of ligustrazine injection on mitophagy in neonatal rats with hypoxic-ischemic encephalopathy (HIE) and its molecular mechanism. METHODS: Neonatal Sprague-Dawley rats, aged 7 days, were randomly divided into a sham-operation group with 8 rats, a model group with 12 rats, and a ligustrazine group with 12 rats. The rats in the model group and the ligustrazine group were used to establish a neonatal rat model of HIE by ligation of the left common carotid artery followed by hypoxia treatment, and blood vessels were exposed without any other treatment for the rats in the sham-operation group. The rats in the ligustrazine group were intraperitoneally injected with ligustrazine (20 mg/kg) daily after hypoxia-ischemia, and those in the sham-operation group and the model group were intraperitoneally injected with an equal volume of normal saline daily. Samples were collected after 7 days of treatment. Hematoxylin and eosin staining and Nissl staining were used to observe the pathological changes of neurons in brain tissue; immunohistochemical staining was used to observe the positive expression of PINK1 and Parkin in the hippocampus and cortex; TUNEL staining was used to measure neuronal apoptosis; Western blotting was used to measure the expression levels of the mitophagy pathway proteins PINK1 and Parkin and the autophagy-related proteins Beclin-1, microtubule-associated protein 1 light chain 3 (LC3), and ubiquitin-binding protein (P62). RESULTS: Compared with the sham-operation group, the model group had a significant reduction in the number of neurons, an increase in intercellular space, loose arrangement, lipid vacuolization, and a reduction in Nissl bodies. The increased positive expression of PINK1 and Parkin, apoptosis rate of neurons, and protein expression levels of PINK1, Parkin, Beclin1 and LC3 (P<0.05) and the decreased protein expression level of P62 in the hippocampus were also observed in the model group (P<0.05). Compared with the model group, the ligustrazine group had a significant increase in the number of neurons with ordered arrangement and an increase in Nissl bodies, significant reductions in the positive expression of PINK1 and Parkin, the apoptosis rate of neurons, and the protein expression levels of PINK1, Parkin, Beclin1, and LC3 (P<0.05), and a significant increase in the protein expression level of P62 (P<0.05). CONCLUSIONS Ligustrazine can alleviate hypoxic-ischemic brain damage and inhibit neuronal apoptosis in neonatal rats to a certain extent, possibly by inhibiting PINK1/Parkin-mediated autophagy.
Rats ; Animals ; Hypoxia-Ischemia, Brain/metabolism* ; Animals, Newborn ; Rats, Sprague-Dawley ; Beclin-1 ; Autophagy ; Ubiquitin-Protein Ligases/metabolism* ; Protein Kinases/metabolism*

OBJECTIVES: Application of ultrashort wave (USW) to rats with cerebral ischemia and reperfusion injury could inhibit the decrease of expression of secretory pathway Ca²⁺-ATPase 1 (SPCA1), an important participant in Golgi stress, reduce the damage of Golgi apparatus and the apoptosis of neuronal cells, thereby alleviating cerebral ischemia-reperfusion injury. This study aims to investigate the effect of USW on oxygen-glucose deprivation/reperfusion (OGD/R) injury and the expression of SPCA1 at the cellular level. METHODS: N2a cells were randomly divided into a control (Con) group, an OGD/R group, and an USW group. The cells in the Con group were cultured without exposure to OGD. The cells in the OGD/R group were treated with OGD/R. The cells in the USW group were treated with USW after OGD/R. Cell morphology was observed under the inverted phase-contrast optical microscope, cell activity was detected by cell counting kit-8 (CCK-8), apoptosis was detected by flow cytometry, and SPCA1 expression was detected by Western blotting. RESULTS: Most of the cells in the Con group showed spindle shape with a clear outline and good adhesion. In the OGD/R group, cells were wrinkled, with blurred outline, poor adhesion, and lots of suspended dead cells appeared; compared with the OGD/R group, the cell morphology and adherence were improved, with clearer outlines and fewer dead cells in the USW group. Compared with the Con group, the OGD/R group showed decreased cell activity, increased apoptotic rate, and down-regulating SPCA1 expression with significant differences (all P<0.001); compared with the OGD/R group, the USW group showed increased cell activity, decreased apoptotic rate, and up-regulating SPCA1 expression with significant differences (P<0.01 or P<0.001). CONCLUSIONS USW alleviates the injury of cellular OGD/R, and its protective effect may be related to its up-regulation of SPCA1 expression.
Animals ; Rats ; Apoptosis ; Brain Ischemia ; Glucose/metabolism* ; Oxygen/metabolism* ; Reperfusion Injury/metabolism* ; Transcriptional Activation ; Up-Regulation ; Calcium-Transporting ATPases/metabolism*

OBJECTIVES: Restoration of blood circulation within "time window" is the principal treating goal for treating acute ischemic stroke. Previous studies revealed that delayed recanalization might cause serious ischemia/reperfusion injury. However, plenty of evidences showed delayed recanalization improved neurological outcomes in acute ischemic stroke. This study aims to explore the role of delayed recanalization on blood-brain barrier (BBB) in the penumbra (surrounding ischemic core) and neurological outcomes after middle cerebral artery occlusion (MCAO). METHODS: Recanalization was performed on the 3rd day after MCAO. BBB disruption was tested by Western blotting, Evans blue dye, and immunofluorescence staining. Infarct volume and neurological outcomes were evaluated on the 7th day after MCAO. The expression of fibroblast growth factor 21 (FGF21), fibroblast growth factor receptor 1 (FGFR1), phosphatidylinositol-3-kinase (PI3K), and serine/threonine kinase (Akt) in the penumbra were observed by immunofluorescence staining and/or Western blotting. RESULTS: The extraversion of Evans blue, IgG, and albumin increased surrounding ischemic core after MCAO, but significantly decreased after recanalization. The expression of Claudin-5, Occludin, and zona occludens 1 (ZO-1) decreased surrounding ischemic core after MCAO, but significantly increased after recanalization. Infarct volume reduced and neurological outcomes improved following recanalization (on the 7th day after MCAO). The expressions of Claudin-5, Occludin, and ZO-1 decreased surrounding ischemic core following MCAO, which were up-regulated corresponding to the increases of FGF21, p-FGFR1, PI3K, and p-Akt after recanalization. Intra-cerebroventricular injection of FGFR1 inhibitor SU5402 down-regulated the expression of PI3K, p-Akt, Occludin, Claudin-5, and ZO-1 in the penumbra, which weakened the beneficial effects of recanalization on neurological outcomes after MCAO. CONCLUSIONS Delayed recanalization on the 3rd day after MCAO increases endogenous FGF21 in the penumbra and activates FGFR1/PI3K/Akt pathway, which attenuates BBB disruption in the penumbra and improves neurobehavior in MCAO rats.
Animals ; Rats ; Blood-Brain Barrier/metabolism* ; Brain Ischemia ; Claudin-5/metabolism* ; Infarction, Middle Cerebral Artery/metabolism* ; Ischemic Stroke/metabolism* ; Occludin/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Rats, Sprague-Dawley ; Receptor, Fibroblast Growth Factor, Type 1/metabolism* ; Reperfusion Injury/metabolism*