Cerebral Infarction Model Research Articles

Synergistic effects of repeated transcranial magnetic stimulation and mesenchymal stem cells transplantation on alleviating neuroinflammation and PANoptosis in cerebral ischemia

BackgroundNeuronal death is the primary cause of poor outcomes in cerebral ischemia. The inflammatory infiltration in the early phase of ischemic stroke plays a vital role in triggering neuronal death. Either transplantation of mesenchymal stem cells (MSCs) derived from humans or repetitive transcranial magnetic stimulation (rTMS) have respectively proved to be neuroprotective and anti-inflammatory in cerebral ischemia. However, either treatment above has its limitations. Whether these two therapies have synergistic effects on improving neurological function and the underlying mechanisms remains unclear. This investigation aims to elucidate the synergistic effects and underlying mechanisms of MSCs combined with rTMS treatment on the neurological function recovery post-ischemia.MethodsA Sprague-Dawley rat model of cerebral infarction was induced via transient middle cerebral artery occlusion (tMCAO). The rats were divided into five groups (n = 50): sham, tMCAO, rTMS, MSCs, and MSCs + rTMS groups. Transplantation of human umbilical cord MSCs and rTMS intervention were performed 24 h post-stroke. Neurological function was further assessed via several behavioral tests and the 2,3,5-triphenyltetrazolium chloride (TTC) staining companied with Nissl staining were used to assess neuronal survival. TUNEL staining, western blotting, immunofluorescence, immunohistochemistry, ELISA, and flow cytometry were employed to measure the levels of neuroinflammation and PANoptosis. The molecular mechanisms underlying the special role of rTMS in the combined therapy were distinguished with transcriptome sequencing via PC12 cells in oxygen-glucose deprivation/reoxygenation (OGD/R) conditions.ResultsThe combined therapy efficiently reduced lesion volume and improved neuronal survival (P < 0.05), subsequently improving functional recovery after ischemic stroke. MSCs + rTMS treatment ameliorated the PANoptosis in neurons (P < 0.05), accompanied by decreased levels of inflammatory factors in the cerebral tissue and serum during the subacute phase of cerebral infarction. To further explore the roles of either therapy on synergistic effect, we found that the transplanted MSCs primarily localized in the spleen and reduced cerebral inflammatory infiltration after ischemia via suppressed splenic inflammation. Meanwhile, rTMS significantly protects neurons from PANoptosis in MSCs-inhibited inflammatory conditions by downregulating REST unveiled by transcriptome sequencing.ConclusionsOur study elucidates an unidentified mechanism by which the combination of MSCs and rTMS could synergistically promote neuronal survival and suppress neuroinflammation during the subacute phase of cerebral infarction, thus improving neurological outcomes. The downregulating REST induced by rTMS may potentially contribute to the neuroprotective effect against PANoptosis in MSCs-inhibited inflammatory conditions. These results are expected to provide novel insights into the mechanisms of MSCs and rTMS combination therapy in synergistically protecting against cerebral ischemia injury and potential targets underlying neuronal PANoptosis in the early phase of stroke.

Tanshinone IIA inhibits the apoptosis process of nerve cells by upshifting SIRT1 and FOXO3α protein and regulating anti- oxidative stress molecules and inflammatory factors in cerebral infarction model

Background As a prevalent cerebrovascular disorder, cerebral infarction (CI) has garnered extensive attention globally due to its high incidence and substantial fatality rate. Ischemia-reperfusion injury (IRI) exacerbates not only neuronal demise but also amplifies neural functional impairment. Tanshinone IIA (Tan IIA) has been identified to confer protection against IRI, yet the precise underlying mechanisms remain elusive. This work aimed to delve into the mechanistic role of Tan IIA in CI, with the goal of furnishing more distinct theoretical substantiation for its clinical application. Methods Initially, a middle cerebral artery embolization model group (MCAO) model was established, followed by the categorization of rats into distinct groups based on different administration modes. Therapeutic effects were evaluated through indices including mortality rate, cerebral tissue water content, CI proportion, and neural functional scoring. Meanwhile, cellular apoptosis rates in hippocampal and cortical tissues, as well as levels of oxidative stress molecules (OSM), Sirtuin 1 (SIRT1), Forkhead box O3 (FOXO3α), and inflammatory factors, were examined to explore the mechanism of action. Results This work revealed that within varying doses of Tan IIA groups, as dosage escalated, mortality rate, cerebral edema severity, CI proportion, and neural functional scoring gradually diminished. Notably, the 35 mg/kg dose group exhibited the most significant reductions, with decreases of 74.9%, 12.7%, 47.5%, and 54%, respectively. Cellular apoptosis rates in hippocampal and cortical tissues displayed a stepwise descending trend, with the 35 mg/kg dose group showcasing the largest reduction. SIRT1 and FOXO3α proteins exhibited a steady increase, with the 35 mg/kg dose group manifesting respective elevations of 87.9% and 65.5%, the highest among all groups. Antioxidant molecules glutathione (GSH) and superoxide dismutase (SOD) contents progressively increased, whereas malondialdehyde (MDA) and nitric oxide (NO) content decreased. The 35 mg/kg dose group recorded the highest increments of 49.1% and 58.1% for GSH and SOD content, while achieving the greatest reductions of 55.6% and 56.2% for MDA and NO content. Expression of inflammatory factors, namely tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), and interleukin-6 (IL-6), gradually declined, with reductions of 42.1%, 32.2%, and 29.1%, respectively, in the 35 mg/kg dose group, exhibiting drastic differences (p < 0.05). Conclusion In conclusion, this research elucidates that Tan IIA improves cerebral edema and neural function by elevating intracellular expression of SIRT1 and FOXO3α proteins, modulating OSM and inflammatory factors. These findings yielded robust experimental support for the potential use of Tan IIA as a therapeutic agent for CI.

Human cranial bone-derived mesenchymal stem cells cultured under simulated microgravity can improve cerebral infarction in rats

The efficacy of transplanting human cranial bone-derived mesenchymal stem cells (hcMSCs) cultured under simulated microgravity (sMG) conditions has been previously reported; however, their effect on cerebral infarction remains unknown. Here, we examined the efficacy of transplanting hcMSCs cultured in an sMG environment into rat models of cerebral infarction. For evaluating neurological function, hcMSCs cultured in either a normal gravity (1G) or an sMG environment were transplanted in rats 1 day after inducing cerebral infarction. The expression of endogenous neurotrophic, axonal, neuronal, synaptogenic, angiogenic, and apoptosis-related factors in infarcted rat brain tissue was examined using real-time polymerase chain reaction and western blotting 35 days after stroke induction. The RNAs of hcMSCs cultured under 1G or sMG environments were sequenced. The results showed that neurological function was significantly improved after transplantation of hcMSCs from the sMG group compared with that from the 1G group. mRNA expressions of nerve growth factor, fibroblast growth factor 2, and synaptophysin were significantly higher in the sMG group than in the 1G group, whereas sortilin 1 expression was significantly lower. RNA sequencing analysis revealed that genes related to cell proliferation, angiogenesis, neurotrophy, neural and synaptic organization, and inhibition of cell differentiation were significantly upregulated in the sMG group. In contrast, genes promoting microtubule and extracellular matrix formation and cell adhesion, signaling, and differentiation were downregulated. These results demonstrate that hcMSCs cultured in the sMG environment may be a useful source of stem cells for the recovery of neurological function after cerebral infarction.

Effect of Xuming Decoction in Records of Proved Prescriptions, Ancient a nd Modern on cerebral ischemic injury and angiogenesis in rat model of acute cerebral infarction

This paper aims to explore the effect of Xuming Decoction in the Records of Proved Prescriptions, Ancient and Modern on cerebral ischemic injury and angiogenesis in the rat model of acute cerebral infarction. SD rats were randomized into 6 groups: sham group, model group, low-, medium-, and high-dose(5.13, 10.26, and 20.52 g·kg~(-1), respectively) Xuming Decoction groups, and butylphthalide(0.06 g·kg~(-1)) group. After the successful establishment of the rat model by middle cerebral artery occlusion(MCAO), rats in the sham and model groups were administrated with distilled water and those in other groups with corresponding drugs for 7 consecutive days. After the neurological function was scored, all the rats were sacrificed, and the brain tissue samples were collected. The degree of cerebral ischemic injury was assessed by the neurological deficit score and staining with 2,3,5-triphenyltetrazolium chloride. Hematoxylin-eosin staining was performed to observe the pathological changes in the brain. Transmission electron microscopy was employed to observe the ultrastructures of neurons and microvascular endothelial cells(ECs) on the ischemic side of the brain tissue. Immunofluorescence assay was employed to detect the expression of von Willebrand factor(vWF) and hematopoietic progenitor cell antigen CD34(CD34) in the ischemic brain tissue. Real-time PCR and Western blot were employed to determine the mRNA and protein levels, respectively, of Runt-related transcription factor 1(RUNX1), vascular endothelial growth factor(VEGF), angiopoietin-1(Ang-1), angiopoietin-2(Ang-2), and VEGF receptor 2(VEGFR2) in the ischemic brain tissue. The results showed that compared with the sham group, the model group showed increased neurological deficit score and cerebral infarction area(P&lt;0.01), pathological changes, and damaged ultrastructure of neurons and microvascular ECs in the ischemic brain tissue. Furthermore, the modeling up-regulated the mRNA levels of RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P&lt;0.01) and the protein levels of vWF, CD34, RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P&lt;0.05 or P&lt;0.01). Compared with the model group, high-dose Xuming Decoction and butylphthalide decreased the neurological deficit score and cerebral infarction area(P&lt;0.01) and alleviated the pathological changes and damage of the ultrastructure of neurons and microvascular ECs in the ischemic brain tissue. Moreover, they up-regulated the mRNA levels of RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P&lt;0.01) and the protein levels of vWF, CD34, RUNX1, VEGF, Ang-1, Ang-2, and VEGFR2(P&lt;0.01). The results suggest that Xuming Decoction in the Records of Proved Prescriptions, Ancient and Modern can promote the angiogenesis and collateral circulation establishment to alleviate neurological dysfunction of the ischemic brain tissue in MCAO rats by regulating the RUNX1/VEGF pathway.

Electroacupuncture ameliorates gastrointestinal dysfunction by modulating DMV cholinergic efferent signals to drive the vagus nerve in p-MCAO rats

BackgroundThe use of proton pump inhibitors in the acute phase of cerebral infarction may lead to adverse long-term outcomes, this study aims to explore the potential of electroacupuncture (EA) in replacing omeprazole in exerting post-stroke gastrointestinal protection. MethodsA permanent middle cerebral artery infarction model was established using the modified Longa thread occlusion technique. Gastrointestinal motility, gastrointestinal mucosal damage, cerebral infarct volume, and alterations in choline acetyltransferase (ChAT)-positive neurons within the dorsal motor nucleus of the vagus nerve (DMV) were assessed after 7 days of EA at Zusanli (ST36) or omeprazole intervention. To evaluate the role of the vagal nerve in mitigating post-stroke gastrointestinal dysfunction, we employed subdiaphragmatic vagotomy and the ChAT-specific inhibitor α-NETA. Additionally, we utilized methyllycaconitine (MLA), a selective inhibitor of the α7-type nicotinic acetylcholine receptor (α7nAChR), and PNU282987, an agonist, to identify the target of EA. ResultsEA restored ChAT neurons lost in the DMV, activated the vagus nerve and conferred cerebroprotection while ameliorating gastrointestinal mucosal injury and gastrointestinal motility disorders. In addition, following the administration of the α7nAChR antagonist, the attenuation of gastric mucosal injury and inflammatory factors induced by EA was hindered, although gastrointestinal motility still exhibited improvement. ConclusionEA at ST36 promotes the restoration of cholinergic signaling in the DMV of stroke-afflicted rats, and its excitation of the vagal nerve inhibits gastrointestinal inflammation after stroke via α7nAChR, while improvement in gastrointestinal motility could be mediated by other acetylcholine receptors.

Piezo1 Knockout Improves Post-Stroke Cognitive Dysfunction by Inhibiting the Interleukin-6 (IL-6)/Glutathione Peroxidase 4 (GPX4) Pathway.

Cerebral infarction often results in post-stroke cognitive impairment, which impairs the quality of life and causes long-term disability. Astrocytes, the most abundant glial cells in the central nervous system, have a crucial role in cerebral ischemia and neuroinflammation. We explored the possible advantages of interleukin-6 (IL-6), a powerful pro-inflammatory cytokine produced by astrocytes, for post-stroke cognitive function. Mendelian randomization was applied to analyze the GWAS database of stroke patients, obtaining a causal relationship between IL-6 and stroke. Further validation of this relationship and its mechanisms was conducted. Using a mouse model of cerebral infarction, we demonstrated a significant increase in IL-6 expression in astrocytes surrounding the ischemic lesion. This protective effect of Piezo1 knockout was attributed to the downregulation of matrix metalloproteinases and upregulation of tight junction proteins, such as occludin and zonula occludens-1 (ZO-1). Two-step Mendelian randomization revealed that IL-6 exposure is a risk factor for stroke. Moreover, we conducted behavioral assessments and observed that Piezo1 knockout mice that received intranasal administration of astrocyte-derived IL-6 showed notable improvement in cognitive function compared to control mice. This enhancement was associated with reduced neuronal cell death and suppressed astrocyte activation, preserving ZO-1. Our study shows that astrocyte-derived IL-6 causes cognitive decline after stroke by protecting the blood-brain barrier. This suggests that piezo1 knockout may reduce cognitive impairment after brain ischemia. Further research on the mechanisms and IL-6 delivery methods may lead to new therapies for post-stroke cognition.

Temporal expression profiles of microRNAs associated with acute phase of brain ischemia in gerbil hippocampus

Neuroprotective therapeutic potential for restoring dysregulated microRNA (miRNA) expression has previously been demonstrated in a gerbil cerebral infarction model. However, since temporal changes in miRNA expression profiles following stroke onset are unknown, miRNAs proving to be useful therapeutic targets have yet to be identified. We evaluated cognitive function, hippocampal neuronal cell death, and microarray-based miRNA expression profiles at 5, 9, 18, 36, and 72 h after 5-min whole brain ischemia in gerbils. A decline in cognitive function occurred in parallel with increased neuronal cell death 36–72 h after ischemia. The Jonckheere-Terpstra test was used to analyze miRNA expression trends 5–72 h after ischemia. The expression levels of 63 miRNAs were significantly upregulated, whereas 32 miRNAs were significantly downregulated, monotonically. Of the 32 monotonically downregulated miRNAs, 18 showed the largest decrease in expression 5–9 h after ischemia. A subset of these dysregulated miRNAs (miR-378a-5p, miR-204-5p, miR-34c-5p, miR-211-5p, miR-34b-3p, and miR-199b-3p) could be associated with brain ischemia and neuropsychiatric disorders.

The GLP-1 receptor agonist exenatide improves recovery from spinal cord injury by inducing macrophage polarization toward the M2 phenotype.

Although a wide variety of mechanisms take part in the secondary injury phase of spinal cord injury (SCI), inflammation is the most important factor implicated in the sequelae after SCI. Being central to the inflammation reaction, macrophages and their polarization are a topic that has garnered wide interest in the studies of SCI secondary injury. The glucagon-like peptide 1 (GLP-1) receptor agonist exenatide has been shown to enhance the endoplasmic reticulum stress response and improve motor function recovery after spinal cord injury (SCI). Since exenatide has also been reported to induce the production of M2 cells in models of cerebral infarction and neurodegenerative diseases, this study was conducted to examine the effects of exenatide administration on the inflammation process that ensues after spinal cord injury. In a rat contusion model of spinal cord injury, the exenatide group received a subcutaneous injection of 10 μg exenatide immediately after injury while those in the control group received 1 mL of phosphate-buffered saline. Quantitative RT-PCR and immunohistochemical staining were used to evaluate the effects of exenatide administration on the macrophages infiltrating the injured spinal cord, especially with regard to macrophage M1 and M2 profiles. The changes in hind limb motor function were assessed based on Basso, Beattie, Bresnahan locomotor rating scale (BBB scale) scores. The improvement in BBB scale scores was significantly higher in the exenatide group from day 7 after injury and onwards. Quantitative RT-PCR revealed an increase in the expression of M2 markers and anti-inflammatory interleukins in the exenatide group that was accompanied by a decrease in the expression of M1 markers and inflammatory cytokines. Immunohistochemical staining showed no significant difference in M1 macrophage numbers between the two groups, but a significantly higher number of M2 macrophages was observed in the exenatide group on day 3 after injury. Our findings suggest that exenatide administration promoted the number of M2-phenotype macrophages after SCI, which may have led to the observed improvement in hind limb motor function in a rat model of SCI.

ATF4 Exacerbates Cerebral Infarction-Induced Sensory Dysfunction via HDAC1/DNMT1/GPX4 Signaling.

Cerebral infarction is the main cause of death and long-term disability worldwide. Neuronal degeneration and limp sensory dysfunction are the secondary damages induced by cerebral infarction. This study aimed to investigate the roles of activating transcription factor 4 (ATF4) in cerebral infarction and the underlying molecular mechanisms. Middle cerebral artery occlusion (MCAO) surgery was applied to establish a cerebral infarction model in vivo. Histological analysis was performed using Nissl assay. Gene expression was determined using immunohistochemistry, immunofluorescence, and Western blot. Gene interaction was confirmed by co-immunoprecipitation (Co-IP), chromatin immunoprecipitation (ChIP), and luciferase assays. Cellular functions were determined using Cell Counting Kit assay (CCK-8), propidium iodide (PI) staining, and terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assays. ATF4 was overexpressed in cerebral infarction models in vivo and in vitro. However, ATF4 knockdown decreased ischemic foci and volume and restored sensory functions in vivo. ATF4 knockdown suppressed lipid peroxidation and neuronal ferroptosis in vitro. Moreover, ATF4 activated DNA methyltransferase 1 (DNMT1), which induced glutathione peroxidase 4 (GPX4) DNA methylation and decreased its expression. GPX4 knockdown alleviated the effects of shATF4 and promoted neuronal ferroptosis. Overall, ATF4 knockdown protected against cerebral infarction and sensory dysfunction by promoting DNMT1-mediated DNA methylation of GPX4.

Correction to “Hypoxic preconditioning improves the survival and neural effects of transplanted mesenchymal stem cells via CXCL12/CXCR4 signalling in a rat model of cerebral infarction”

Correction to “Hypoxic preconditioning improves the survival and neural effects of transplanted mesenchymal stem cells via CXCL12/CXCR4 signalling in a rat model of cerebral infarction”

Ultrasound-Targeted Microbubble Destruction Increases BBB Permeability and Promotes Stem Cell-Induced Regeneration of Stroke by Downregulating MMP8.

The objective of this study was to evaluate the feasibility, safety, and effectiveness of intravenous stem cell delivery utilizing ultrasound-targeted microbubble destruction (UTMD) in a rat model of middle cerebral artery occlusion (MCAO), while investigating the underlying mechanisms. Acute cerebral infarction (ACI) was induced surgically in adult rats to create the MCAO rat model. Intravenous injection of SonoVue microbubbles and bone marrow-derived mesenchymal stem cells (BMSC) was performed concurrently, with or without ultrasound targeting the stroke. The animals were divided into four groups: sham-operated group, ACI-MCAO rats treated with phosphate-buffered saline (ACI+PBS), rats receiving intravenous delivery of BMSC expressing green fluorescent protein (GFP-BMSC; ACI+BMSC), and rats receiving intravenous GFP-BMSC with simultaneous UTMD exposure (ACI+BMSC+UTMD). The efficacy of the treatments was assessed by evaluating the animals' neurological function using the Longa score and examining histopathological changes such as cerebral infarct volume, cerebral edema, and cell apoptosis. A rat cytokine array was utilized to identify the potential cytokines that may be responsible for the therapeutic effect of UTMD-mediated BMSC treatment. Optimal UTMD parameters resulted in an increase in blood-brain barrier (BBB) permeability after 30 min, which returned to baseline 72 h later without causing any residual injury. UTMD application significantly increased the homing of intravenously delivered BMSC, resulting in a 2.2-fold increase in GFP-BMSC cell count on day 3 and a 2.6-fold increase on day 7 compared with intravenous delivery alone. This effect persisted for up to 6 weeks after injection. Intravenous BMSC delivery significantly reduced the volume of cerebral infarct and decreased cerebral edema, leading to a lower Longa score. Furthermore, this effect was further enhanced by UTMD. Acute cerebral infarction induced by MCAO led to elevated matrix metalloproteinase 8 (MMP8) levels in the cerebrospinal fluid, which were significantly reduced following UTMD-mediated BMSC treatment. Ultrasound-targeted microbubble destruction facilitates the migration and homing of BMSC into the brain, possibly by transiently increasing blood-brain barrier (BBB) permeability, thereby improving therapeutic outcomes in an ACI rat model. The observed effect may be partly attributed to modulation of MMP8 levels.Advances in knowledge: UTMD-mediated intravenously delivered BMSC transplantation led to a significant increase in cell homing and reduction of MMP8 levels, resulting in increased therapeutic effect in an acute ischemic cerebral infarction model.

SRSF3 Alleviates Ischemic Cerebral Infarction Damage by Activating the PI3K/AKT Pathway

Background: Ischemic cerebral infarction is one of cerebrovascular diseases with high incidence, disability rate, and mortality globally, and neuronal cell apoptosis is a crucial cause of brain injury during cerebral infarction. Methods: A middle cerebral artery occlusion (MCAO) model was built in Sprague-Dawley rats to simulate ischemic cerebral infarction. An in vitro model of ischemic cerebral infarction was constructed in BV2 cells with the treatment of oxygen-glucose deprivation (OGD). The role and mechanism of serine/arginine-rich splicing factor 3 (SRSF3) in ischemic cerebral infarction were investigated both in animal and cell models. Results: The expression of SRSF3 was downregulated in MCAO-treated rats. Overexpression of SRSF3 reduced the neurological scores, brain water content, and infarct volume in MCAO-induced rats. Increased apoptosis in neurons accompanied with the abnormal expressions of apoptosis-related proteins in MCAO-induced rats were revised with the upregulation of SRSF3. Also, a diminished cell viability and elevated apoptosis rate were indicated in OGD-induced BV2 cells, which were reversed with the overexpression of SRSF3. Besides, OGD induced an enhancement in the relative protein expression of programmed cell death protein 4 (PDCD4) and a reduction in the relative expression of p-PI3K/PI3K and p-AKT/AKT, which were inverted with the upregulation of SRSF3 in BV2 cells. Overexpression of PDCD4 abolished the role of SRSF3 in cell viability, apoptosis rate, and the level of the PI3K/AKT pathway in OGD-induced BV2 cells. Conclusion: SRSF3 improved ischemic cerebral infarction via PDCD4 in vivo and in vitro, which was closely associated with the PI3K/AKT signaling pathway.

MiR-182 promotes apoptosis of neural cells in cerebral infarction rats by PI3K/AKT signaling pathway.

To explore the effects of micro ribonucleic acid (miR)-182 on the proliferation and apoptosis of neural cells in cerebral infarction rats and its underlying mechanism. The rat model of cerebral infarction was established, and neural cells were extracted accordingly. The cell proliferation ability was detected via cell counting kit-8 (CCK8) assay. In addition, the apoptosis rate was determined through flow cytometry and the activity of active caspase-3. Furthermore, the interaction between miR-182 and PI3K was explored via dual luciferase reporter assay, and the protein expression levels were observed via Western blotting. The neural cells in mouse brain tissues significantly decreased in the model group compared with that in the control group via HE stain. Additionally, the expression level of miR-182 was significantly increased in the model group compared with that in the control group. Furthermore, overexpression of miR-182 could inhibit the proliferation of neural cells through inducing cell apoptosis. Besides, the results of the luciferase reporter assay showed that the relative luciferase activity in neural cells could be inhibited by the transfection with miR-182 (P<0.05). Overexpression of miR-182 significantly reduced the protein expression levels of phosphatidylinositol 3-hydroxy kinase (PI3K) and p-AKT. MiR-182 induces apoptosis of neural cells through inhibiting the PI3K/AKT signaling pathway, which plays an important regulatory role in the apoptosis of neural cells in cerebral infarction rats.

MiR-26a Improves Microglial Activation and Neuronal Apoptosis in a Rat Model of Cerebral Infarction by Regulating the TREM1-TLR4/MyD88/NF-κB Axis

Emerging studies have indicated that abnormally expressed microRNAs (miRNAs) are related to the pathogenesis of cerebral ischemia. Nevertheless, the function of miR-26a in neuronal damage and microglial activation during cerebral infarction remains elusive. It was revealed that miR-26a was downregulated in oxygen-glucose deprivation (OGD)-treated microglia and neurons. Overexpressing miR-26a reduced the inflammatory reaction in BV2 cells and decreased neuronal apoptosis following OGD stimulation. miR-26a upregulation inactivated the TLR4/MyD88/NF-κB pathway and inhibited TREM1 expression. Repressing NF-κB phosphorylation inhibited the miR-26a level. As supported by the dual-luciferase reporter assay, TREM1 was directly targeted by miR-26a. Furthermore, a rat model of middle cerebral artery occlusion (MCAO) was built. We discovered that miR-26a improved cognitive, learning, and motor functions and reduced cerebral edema in MCAO rats. Mechanistically, upregulating miR-26a reduced inflammation and neuronal apoptosis by mitigating the TREM1-TLR4/MyD88/NF-κB pathway in the MCAO rat model. Collectively, this study verified that the miR-26a-TREM1-TLR4/MyD88/NF-κB axis contributes to modulating OGD-mediated microglial activation and neuronal injury.

FNDC5 inhibits autophagy of bone marrow mesenchymal stem cells and promotes their survival after transplantation by downregulating Sp1

Regenerative therapy based on mesenchymal stem cells (MSCs) has great promise to achieve functional recovery in cerebral infarction patients. However, the survival rate of transplanted MSCs is extremely low because of destructive autophagy caused by the harsh ischemic microenvironment in cerebral infarct tissue. The mechanism by which fibronectin type III domain protein 5 (FNDC5) regulates autophagy of transplanted bone marrow-MSCs (BMSCs) following ischemic injury needs to be elucidated. In this study, we confirmed that FNDC5 promotes the survival of transplanted BMSCs in a rat cerebral infarction model. Furthermore, bioinformatic analysis and verification experiments revealed the transcription factor, Sp1, to be a key mediator of autophagy regulation by FNDC5. FNDC5 significantly inhibited BMSC autophagy by down-regulating Sp1 and the autophagy-related Sp1-target gene, ULK2. Transplanted BMSCs overexpressing FNDC5 (BMSCs-OE-FNDC5) promoted neurovascular proliferation and alleviated ischemic brain injury in cerebral infarct model rats. However, the increased survival and enhanced neuroprotective effect of transplanted BMSCs-OE-FNDC5 were reversed by simultaneous overexpression of Sp1. Our data indicate a role for FNDC5 in BMSC survival and reveal a novel mechanism of transcription regulation through Sp1 for the autophagy-related gene ULK2. Modulation of FNDC5 may promote survival capacity and improve the therapeutic effect of BMSCs in various tissues following ischemia.

Bone marrow-derived mononuclear cells ameliorate neurological function in chronic cerebral infarction model mice via improvement of cerebral blood flow

Background aimsStroke is a frequently observed neurological disorder that might lead to permanent and severe disability. Recently, various regenerative therapies have been developed, some of which have already been applied clinically. However, their outcomes have not been fully satisfactory. In particular, the development of regenerative therapies for chronic ischemic stroke is greatly needed. Herein intracerebral administration of bone marrow-derived mononuclear cells (BM-MNCs) was assessed as a potential treatment for chronic ischemic stroke using a severe combined immunodeficiency mouse model characterized by minimal vascular variation unrelated to immunodeficiency. MethodsA reproducible model of permanent middle cerebral artery occlusion was prepared, and intracerebral BM-MNC transplantation was performed 14 days after stroke induction in the infarcted brain. ResultsSensorimotor behavioral function and cerebral blood flow were significantly improved upon treatment with BM-MNCs compared to control medium injection. The transplanted cells exhibited characteristics of the vascular endothelium and microglia/macrophages. Significant angiogenesis and suppression of astrogliosis and microgliosis were observed in the affected brain. Messenger RNA expression analysis showed significant increases in anti-inflammatory cytokines, A2 astrocyte/anti-inflammatory microglia markers and vascular endothelial markers such as vascular endothelial growth factor and significant decreases in pro-inflammatory cytokines and A1 astrocyte/pro-inflammatory microglia markers following BM-MNC transplantation. ConclusionsThese results suggest that intracerebral administration of BM-MNCs should be considered an effective cell therapy for chronic stroke.

Model of small-focal ischemic cerebral infarction as a basis for the development of new methods of stroke therapy

Background. Among the existing experimental models of cerebral stroke in large animals, there is no possibility to create a focal brain infarction of limited volume, which would provide an opportunity to evaluate both the endogenous potential of neuroregeneration and to establish the effectiveness of new drugs on postischemic brain remodeling.&#x0D; Aim. Development of a method for modeling small-focal ischemic infarction of the cerebral cortex in a mini-pig.&#x0D; Material and methods. The study used mature female mini-pigs of the Vietnamese fold-bellied breed. Two-level occlusion of the great vessels was performed by ligation of the right common carotid artery and subsequent cauterization of the distal branches of the middle cerebral artery. In the postoperative period, the survival rate of animals and neurological deficit were assessed. On the 7th day, the animals were taken out of the experiment, the brain was isolated from the cranial box. Macroscopic and microscopic examinations included analysis of the localization and area of cerebral infarction, as well as morphological changes in the infarcted and peri-infarcted areas of the cerebral cortex.&#x0D; Results. With a 100% survival rate of experimental animals on the 3rd day after the operation, a neurological examination revealed violations of skin sensitivity and muscle tone in the hind and fore limbs, which partially recovered a week after the onset of ischemic stroke. Macroscopic examination of the brain on the 7th day after the operation visually revealed a small-focal ischemic cerebral infarction in the parietal lobe of the left hemisphere. Histological analysis of the cerebral cortex revealed a wedge-shaped necrotic focus of ischemic injury. In the peri-infarction region of the brain, reactive tissue changes with preserved nerve cells, mostly without visible damage, were found.&#x0D; Conclusion. The developed two-level method of stroke modeling in a mini pig induces ischemic cerebral infarction of limited volume in the parietal lobe; non-critical histological changes in the peri-infarct area and a slight neurological deficit suggest the possibility of using this model to develop new methods of stroke therapy.

Effects of exercise and bryostatin-1 on functional recovery and posttranslational modification in the perilesional cortex after cerebral infarction.

Strokes can cause a variety of sequelae, such as paralysis, particularly in the early stages after stroke onset. Rehabilitation therapy atthis time often provides some degree of paralysis recovery. Neuroplasticity in the peri-infarcted cerebral cortex induced by exercise training may contribute to recovery of paralysis after cerebral infarction. However, the molecular mechanism of this process remains unclear. This study focused on brain protein kinase C (PKC), which is speculated to be involved in neuroplasticity. We evaluated the functional recovery of cerebral infarction model rats, by using rotarod test after running wheel training and with/without administration of bryostatin, a PKC activator. In addition, the expression of phosphorylated and unphosphorylated PKC subtypes, glycogen synthase kinase 3β (GSK3β), and collapsin response-mediator proteins 2 (CRMP2) were analyzed by Western blotting. In the rotarod test, bryostatin administration alone had no effect on gait duration, but the combination of training and this drug significantly prolonged gait duration compared with training alone. In protein expression analysis, the combination of training and bryostatin significantly increased phosphorylation of PKCα and PKCε isoforms, increased phosphorylation of GSK3β, which acts downstream of PKC, and decreased phosphorylation of CRMP2. The effect of bryostatin in combination with training appears to be mediated via PKC phosphorylation, with effects on functional recovery occurring through the downstream regulation of GSK3β and CRMP2 phosphorylation.

Enhanced angiogenic properties of umbilical cord blood primed by OP9 stromal cells ameliorates neurological deficits in cerebral infarction mouse model

Umbilical cord blood (UCB) transplantation shows proangiogenic effects and contributes to symptom amelioration in animal models of cerebral infarction. However, the effect of specific cell types within a heterogeneous UCB population are still controversial. OP9 is a stromal cell line used as feeder cells to promote the hematoendothelial differentiation of embryonic stem cells. Hence, we investigated the changes in angiogenic properties, underlying mechanisms, and impact on behavioral deficiencies caused by cerebral infarction in UCB co-cultured with OP9 for up to 24 h. In the network formation assay, only OP9 pre-conditioned UCB formed network structures. Single-cell RNA sequencing and flow cytometry analysis showed a prominent phenotypic shift toward M2 in the monocytic fraction of OP9 pre-conditioned UCB. Further, OP9 pre-conditioned UCB transplantation in mice models of cerebral infarction facilitated angiogenesis in the peri-infarct lesions and ameliorated the associated symptoms. In this study, we developed a strong, fast, and feasible method to augment the M2, tissue-protecting, pro-angiogenic features of UCB using OP9. The ameliorative effect of OP9-pre-conditioned UCB in vivo could be partly due to promotion of innate angiogenesis in peri-infarct lesions.

In vivo evaluation of histopathologic findings of vascular damage after mechanical thrombectomy with the Tromba device in a canine model of cerebral infarction.

A novel stent retriever device for in vivo mechanical thrombectomy for acute cerebral infarction has been developed. In this study, we compared the thrombus removal capacity, potential complications, and extent of vessel wall damage of this novel device with those of the Solitaire FR device by performing a histopathologic analysis using an autopsied canine model. Through this experimental evaluation, we aimed to assess the safety and efficacy of the newly developed thrombus removal device for cerebral infarction. Blood clots (autologous thrombus) were injected into 12 canines. Mechanical thrombectomy was performed in six canines using the newly developed Tromba thrombectomy device (experimental group) and in the other six canines using the Solitaire FR thrombectomy device (control group). Angiographic and histopathologic evaluations were performed 1 month after the blood vessels underwent mechanical thrombectomy. In the experimental group, the reperfusion patency was classified as "no narrowing" in five cases and "moderate narrowing (25%-50% stenosis)" in one case. In the control group, the reperfusion patency was classified as "no narrowing" in four cases, "moderate narrowing (25%-50% stenosis)" in one case, and "slight narrowing (less than 25% stenosis)" in one case. In the experimental group, intimal proliferation was observed in only two cases, endothelial loss was observed in two cases, and device-induced medial injury was observed in one case. In the control group, intimal proliferation was observed in two cases, endothelial loss was observed in one case, and thrombosis (fibrin/platelet) was observed in one case. The Tromba thrombectomy device showed no significant difference to the conventional Solitaire device in angiographic and histopathologic evaluations after thrombus removal. The stability and efficiency of the newly developed Tromba device are considered to be high and comparable to those of Solitaire.