Intrastriatal transplantation of bone marrow nonhematopoietic cells improves functional recovery after stroke in adult mice

Nuclear receptor coactivator 4-mediated ferritinophagy contributes to cerebral ischemia-induced ferroptosis in ischemic stroke

Ischemic stroke poses a significant health risk due to its high rate of disability and mortality. To address this problem, several therapeutic approaches have been proposed, including interruption targeting programmed cell death (PCD). Ferroptosis is a newly defined PCD characterized by iron-dependent accumulation of lipid peroxidation, and is becoming a promising target for treating numerous diseases. To explore the underlying mechanisms of the initiation and execution of ferroptosis in ischemic stroke, we established stroke models in vivo and in vitro simulating ischemia/reperfusion (I/R) neuronal injury. Different from previous reports on stroke, we tested ferroptosis by measuring the levels of core proteins, such as ACSL4, 15-LOX2, Ferritin and GPX4. In addition, I/R injury induces excessive degradation of ferritin via the autophagy pathway and subsequent increase of free iron in neurons. This phenomenon has recently been termed ferritinophagy and reported to be regulated by nuclear receptor coactivator 4 (NCOA4) in some cell lines. Increased NCOA4 in cytoplasm was detected in our study and then silenced by shRNA to investigate its function. Both in vivo and in vitro, NCOA4 deletion notably abrogated ferritinophagy caused by I/R injury and thus inhibited ferroptosis. Furthermore, we found that NCOA4 was upregulated by ubiquitin specific peptidase 14 (USP14) via a deubiquitination process in damaged neurons, and we found evidence of pharmacological inhibition of USP14 effectively reducing NCOA4 levels to protect neurons from ferritinophagy-mediated ferroptosis. These findings suggest a novel and effective target for treating ischemic stroke.

Sult2b1 deficiency exacerbates ischemic stroke by promoting pro-inflammatory macrophage polarization in mice

Rationale: Stroke is a leading causes of human death worldwide. Ischemic damage induces the sterile neuroinflammation, which directly determines the recovery of patients. Lipids, a major component of the brain, significantly altered after stroke. Cholesterol sulfate, a naturally occurring analog of cholesterol, can directly regulate immune cell activation, indicating the possible involvement of cholesterol metabolites in neuroinflammation. Sulfotransferase family 2b member 1 (Sult2b1) is the key enzyme that catalyzes the synthesis of cholesterol sulfate. This study aimed to investigate the function of Sult2b1 and cholesterol sulfate in the neuroinflammation after ischemic stroke.

Methods and Results: Sult2b1^-/- and wild-type mice were subjected to transient middle cerebral artery occlusion. Our data showed that Sult2b1^-/- mice had larger infarction and worse neurological scores. To determine whether immune cells were involved in the worsening stroke outcome in Sult2b1^-/- mice, bone marrow transplantation, immune cell depletion, and adoptive monocyte transfer were performed. Combined with CyTOF and immunofluorescence techniques, we demonstrated that after stroke, the peripheral monocyte-derived macrophages were the dominant cell type promoting the pro-inflammatory status in Sult2b1^-/-mice. Using primary bone marrow-derived macrophages, we showed that cholesterol sulfate could attenuate the pro-inflammatory polarization of macrophages under both normal and oxygen-glucose deprivation conditions by regulating the levels of nicotinamide adenine dinucleotide phosphate (NADPH), reactive oxygen species (ROS), and activating the AMP-activated protein kinase (AMPK) - cAMP responsive element-binding protein (CREB) signaling pathway.

Conclusions:Sult2b1^-/- promoted the polarization of macrophages into pro-inflammatory status. This trend could be attenuated by adding cholesterol sulfate, which promotes the polarization of macrophages into anti-inflammatory status by metabolic regulation. In this study, we established an inflammation-metabolism axis during the macrophage polarization after ischemic stroke.

Circular RNA 0025984 Ameliorates Ischemic Stroke Injury and Protects Astrocytes Through miR-143-3p/TET1/ORP150 Pathway

MiR-143-3p is aberrantly expressed in patients with ischemic stroke and associated with ischemic brain injury. However, the underlying mechanisms are largely unknown. Here, we confirmed circ_0025984 and TET1 as a sponge and target of miR-143-3p, respectively, by luciferase reporter assay. In astrocytes, OGD significantly decreased circ_0025984 and TET1 levels but increased miR-143-3p levels, which was also observed in brains of mice with MCAO. Treatment with miR-143-3p inhibitor or circ_0025984 significantly decreased astrocyte apoptosis and autophagy, as well as cerebral injury and neuron loss in mice with MCAO. Notably, TET1 overexpression decreased astrocyte apoptosis and autophagy and induced promoter hypomethylation and expression of ORP150. Our results demonstrated for the first time that circ_0025984 protects astrocytes from ischemia-induced autophagy and apoptosis by targeting the miR-143-3p/TET1 pathway and might inhibit cerebral injury induced by ischemic stroke. Furthermore, our data revealed the important positive regulation of ORP150 by TET1, which could be associated with its neuroprotective role. Graphical abstract Model for signaling pathway of circ_0025984/miR-143-3p/TET1 inastrocytes cultured under OGD. In astrocytes, circ_0025984 acts as a sponge of miR-143-3p, which directly targets TET1 and decreases its expression (A). After translocatinginto the nucleus, TET1 binds to the promoter of ORP150, converts 5mC into 5hmC,leading to DNA demethylation and increased expression of ORP150 (B). In astrocytescultured under OGD, ER stress is induced and eventually leads to apoptosis andautophagy mediated by ATG7, which is regulated by circ_0025984 via ORP150 andGRP78 (C).

Dental pulp stem cell-derived exosomes alleviate cerebral ischaemia-reperfusion injury through suppressing inflammatory response

Objectives

The study aimed to determine whether dental pulp stem cell‐derived exosomes (DPSC‐Exos) exert protective effects against cerebral ischaemia‐reperfusion (I/R) injury and explore its underlying mechanism.

Materials and Methods

Exosomes were isolated from the culture medium of human DPSC. Adult male C57BL/6 mice were subjected to 2 hours transient middle cerebral artery occlusion (tMCAO) injury followed by 2 hours reperfusion, after which singular injection of DPSC‐Exos via tail vein was administrated. Brain oedema, cerebral infarction and neurological impairment were measured on day 7 after exosomes injection. Then, oxygen‐glucose deprivation–reperfusion (OGD/R) induced BV2 cells were studied to analyse the therapeutic effects of DPSC‐Exos on I/R injury in vitro. Protein levels of TLR4, MyD88, NF‐κB p65, HMGB1, IL‐6, IL‐1β and TNF‐α were determined by western blot or enzyme‐linked immunosorbent assay. The cytoplasmic translocation of HMGB1 was detected by immunofluorescence staining.

Results

DPSC‐Exos alleviated brain oedema, cerebral infarction and neurological impairment in I/R mice. DPSC‐Exos inhibited the I/R‐mediated expression of TLR4, MyD88 and NF‐κB significantly. DPSC‐Exos also reduced the protein expression of IL‐6, IL‐1β and TNF‐α compared with those of the control both in vitro and in vivo. Meanwhile, DPSC‐Exos markedly decreased the HMGB1 cytoplasmic translocation induced by I/R damage.

Conclusions

DPSC‐Exos can ameliorate I/R‐induced cerebral injury in mice. Its anti‐inflammatory mechanism might be related with the inhibition of the HMGB1/TLR4/MyD88/NF‐κB pathway.

The effects of Hippophae rhamnoides in neuroprotection and behavioral alterations against iron-induced epilepsy

Epilepsy is a neurological disorder in which malfunctioning of the electrical activity of the brain causes recurrent, unprovoked seizures. Epilepsy causes wide symptoms that include cognitive dysfunction, anxiety, behavioral alterations, and histological impairments. In this study, the effect of Hippophae rhamnoides (Sea buckthorn/Sbt) on electrophysiology, behavior, and histology in iron-induced epilepsy was analyzed. Rats were randomly divided into four groups (n = 8); Control group, Epileptic group, Sbt treated epileptic group, and Sbt treated group. To induce epilepsy, the intracortical iron injection was administered at a dose of 5 μl of 100 mM FeCl₃. A significant increase in epileptiform activity, behavioral abnormalities, and histological impairments was observed in the iron-induced epileptic rats. Hippophae rhamnoides berry extract was administered orally at a dose of 1 ml/kg body wt. for one month. Sbt administration significantly reduced the epileptiform activity, improved behavioral abnormalities, and improved histological impairments in epileptic rats. In conclusion, this study demonstrates the antiepileptic effect of Sbt that probably has exerted by its neuroprotective and behavioral alteration potential against iron-induced epilepsy.

Recovery of post-stroke cognitive and motor deficiencies by Shuxuening injection via regulating hippocampal BDNF-mediated Neurotrophin/Trk Signaling

A mild ischemic stroke may cause both debilitating locomotor and cognitive decline, for which the mechanism is not fully understood, and no therapies are currently available. In this study, a nonfatal stroke model was constructed in mice by a modified middle cerebral artery occlusion (MCAO) procedure, allowing an extended recovery period up to 28 days. The extended MCAO model successfully mimicked phenotypes of a recovery phase post-stroke, including locomotor motor and cognitive deficiencies, which were effectively improved after Shuxuening injection (SXNI) treatment. Tissue slices staining showed that SXNI repaired brain injury and reduced neuronal apoptosis, especially in the hippocampus CA3 region. Transcriptomics sequencing study revealed 565 differentially expressed genes (DEGs) in the ischemic brain after SXNI treatment. Integrated network pharmacological analysis identified Neurotrophin/Trk Signaling was the most relevant pathway, which involves 15 key genes. Related DEGs were further validated by RT-PCR. Western-blot analysis showed that SXNI reversed the abnormal expression of BDNF, TrkB, Mek3 and Jnk1after stroke. ELISA found that SXNI increased brain level of p-Erk and Creb. At sub-brain level, the expression of BDNF and TrkB was decreased and GFAP was increased on the hippocampal CA3 region in the post-stroke recovery phase and this abnormality was improved by SXNI. In vitro experiments also found that oxygen glucose deprivation reduced the expression of BDNF and TrkB, which was reversed by SXNI. In summary, we conclude that SXNI facilitates the recovery of cognitive and locomotor dysfunction by modulating Neurotrophin/Trk Signaling in a mouse model for the recovery phase of post-ischemic stroke.

Krüppel-Like Factor 6 Silencing Prevents Oxidative Stress and Neurological Dysfunction Following Intracerebral Hemorrhage via Sirtuin 5/Nrf2/HO-1 Axis

As a severe neurological deficit, intracerebral hemorrhage (ICH) is associated with overwhelming mortality. Subsequent oxidative stress and neurological dysfunction are likely to cause secondary brain injury. Therefore, this study sought to define the role of Krüppel-like factor 6 (KLF6) and underlying mechanism in oxidative stress and neurological dysfunction following ICH. An in vivo model of ICH was established in rats by injection of autologous blood, and an in vitro ICH cell model was developed in hippocampal neurons by oxyhemoglobin (OxyHb) exposure. Next, gain- and loss-of-function assays were performed in vivo and in vitro to clarify the effect of KLF6 on neurological dysfunction and oxidative stress in ICH rats and neuronal apoptosis and mitochondrial reactive oxygen species in OxyHb-induced hippocampal neurons. KLF6, nuclear factor erythroid 2–related factor 2 (Nrf2), and heme oxygenase 1 (HO-1) were highly expressed in hippocampal tissues of ICH rats, whereas sirtuin 5 (SIRT5) presented a poor expression. Mechanistically, KLF6 bound to the SIRT5 promoter and transcriptionally repressed SIRT5 to activate the Nrf2/HO-1 signaling pathway. KLF6 silencing alleviated neurological dysfunction and oxidative stress in ICH rats and diminished oxidative stress and neuronal apoptosis in OxyHb-induced neurons, whereas SIRT5 overexpression negated its effect. To sum up, KLF6 silencing elevated SIRT5 expression to inactivate the Nrf2/HO-1 signaling pathway, thus attenuating oxidative stress and neurological dysfunction after ICH.

Zeb2 Is a Regulator of Astrogliosis and Functional Recovery after CNS Injury

The astrocytic response to injury is characterized on the cellular level, but our understanding of the molecular mechanisms controlling the cellular processes is incomplete. The astrocytic response to injury is similar to wound-healing responses in non-neural tissues that involve epithelial-to-mesenchymal transitions (EMTs) and upregulation in ZEB transcription factors. Here we show that injury-induced astrogliosis increases EMT-related genes expression, including Zeb2, and long non-coding RNAs, including Zeb2os, which facilitates ZEB2 protein translation. In mouse models of either contusive spinal cord injury or transient ischemic stroke, the conditional knockout of Zeb2 in astrocytes attenuates astrogliosis, generates larger lesions, and delays the recovery of motor function. These findings reveal ZEB2 as an important regulator of the astrocytic response to injury and suggest that astrogliosis is an EMT-like process, which provides a conceptual connection for the molecular and cellular similarities between astrogliosis and wound-healing responses in non-neural tissue.

Mucosal-Associated Invariant T Cells Are Involved in Acute Ischemic Stroke by Regulating Neuroinflammation

Background Mucosal-associated invariant T (MAIT) cells have been associated with inflammation in several autoimmune diseases. However, their relation to ischemic stroke remains unclear. This study attempted to elucidate the role of MAIT cells in acute ischemic stroke in mice. Methods and Results We used MR1 knockout C57BL/6 (MR1-/-) mice and wild-type littermates (MR1+/+). After performing a transient middle cerebral artery occlusion (tMCAO), we evaluated the association with inflammation and prognosis in the acute cerebral ischemia. Furthermore, we analyzed the tMCAO C57BL/6 mice administered with the suppressive MR1 ligand and the vehicle control. We also evaluated the infiltration of MAIT cells into the ischemic brain by flow cytometry. Results showed a reduction of infarct volume and an improvement of neurological impairment in MR1-/- mice (n=8). There was a reduction in the number of infiltrating microglia/macrophages (n=3-5) and in their activation (n=5) in the peri-infarct area of MR1-/- mice. The cytokine levels of interleukin-6 and interleukin-17 at 24 hours after tMCAO (n=3-5), and for interleukin-17 at 72 hours after tMCAO (n=5), were lower in the MR1-/- mice. The administration of the suppressive MR1 ligand reduced the infarct volume and improved functional impairment (n=5). Flow cytometric analysis demonstrated there was a reduction of MAIT cells infiltrating into the ischemic brain at 24 hours after tMCAO (n=17). Conclusions Our results showed that MAIT cells play an important role in neuroinflammation after focal cerebral ischemia and the use of MAIT cell regulation has a potential role as a novel neuroprotectant for the treatment of acute ischemic stroke.

Bone marrow-derived mesenchymal stem cells improve post-ischemia neurological function in rats via the PI3K/AKT/GSK-3β/CRMP-2 pathway

BACKGROUND

Transplantation of bone marrow-derived mesenchymal stem cells (BMSCs) is a potential therapy for cerebral ischemia. However, the underlying protective mechanism remains undetermined. Here, we tested the hypothesis that transplantation of BMSCs via intravenous injection can alleviate neurological functional deficits through activating PI3K/AKT signaling pathway after cerebral ischemia in rats.

METHODS

A cerebral ischemic rat model was established by the 2 h middle cerebral artery occlusion (MCAO). Twenty-four hours later, BMSCs (1 × 10⁶ in 1 ml PBS) from SD rats were injected into the tail vein. Neurological function was evaluated by modified neurological severity score (mNSS) and modified adhesive removal test before and on d1, d3, d7, d10 and d14 after MCAO. Protein expressions of AKT, GSK-3β, CRMP-2 and GAP-43 were detected by Western-bolt. NF-200 was detected by immunofluorescence.

RESULTS

BMSCs transplantation did not only significantly improve the mNSS score and the adhesive-removal somatosensory test after MCAO, but also increase the density of NF-200 and the expression of p-AKT, pGSK-3β and GAP-43, while decrease the expression of pCRMP-2. Meanwhile, these effects can be suppressed by LY294002, a specific inhibitor of PI3K/AKT.

CONCLUSION

These data suggest that transplantation of BMSCs could promote axon growth and neurological deficit recovery after MCAO, which was associated with activation of PI3K/AKT /GSK-3β/CRMP-2 signaling pathway.

DL-3n-Butylphthalide Improves Blood-Brain Barrier Integrity in Rat After Middle Cerebral Artery Occlusion

Objective: DL-3n-butylphthalide (NBP) has beneficial effects in different stages of ischemic stroke. Our previous studies have demonstrated that NBP promoted angiogenesis in the perifocal region of the ischemic brain. However, the molecular mechanism of NBP for blood–brain barrier protection in acute ischemic stroke was unclear. Here, we explored the neuroprotective effects of NBP on blood–brain barrier integrity in the acute phase of ischemic stroke in a rat model.

Methods: Adult male Sprague–Dawley rats (n = 82) underwent 2 h of transient middle cerebral artery occlusion and received 90 mg/kg of NBP for 3 days. Brain edema, infarct volume, surface blood flow, and neurological severity score were evaluated. Blood–brain barrier integrity was evaluated by Evans blue leakage and changes in tight junction proteins. We further examined AQP4 and eNOS expression, MMP-9 enzyme activity, and possible signaling pathways for the role of NBP after ischemic stroke.

Results: NBP treatment significantly increased eNOS expression and surface blood flow in the brain, reduced brain edema and infarct volume, and improved neurological severity score compared to the control group (p < 0.05). Furthermore, NBP attenuated Evans blue and IgG leakage and increased tight junction protein expression compared to the control after 1 and 3 days of ischemic stroke (p < 0.05). Finally, NBP decreased AQP4 expression, MMP-9 enzyme activity, and increased MAPK expression during acute ischemic stroke.

Conclusion: NBP protected blood–brain barrier integrity and attenuated brain injury in the acute phase of ischemic stroke by decreasing AQP4 expression and MMP-9 enzyme activity. The MAPK signaling pathway may be associated in this process.

Microglia exosomal miRNA-137 attenuates ischemic brain injury through targeting Notch1

Microglia are the resident immune cells in the central nervous system and play an essential role in brain homeostasis and neuroprotection in brain diseases. Exosomes are crucial in intercellular communication by transporting bioactive miRNAs. Thus, this study aimed to investigate the function of microglial exosome in the presence of ischemic injury and related mechanism. Oxygen-glucose deprivation (OGD)-treated neurons and transient middle cerebral artery occlusion (TMCAO)-treated mice were applied in this study. Western blotting, RT-PCR, RNA-seq, luciferase reporter assay, transmission electron microscope, nanoparticle tracking analysis, immunohistochemistry, TUNEL and LDH assays, and behavioral assay were applied in mechanistic and functional studies. The results demonstrated that exosomes derived from microglia in M2 phenotype (BV2-Exo) were internalized by neurons and attenuated neuronal apoptosis in response to ischemic injury in vitro and in vivo. BV2-Exo also decreased infarct volume and behavioral deficits in ischemic mice. Exosomal miRNA-137 was upregulated in BV2-Exo and participated in the partial neuroprotective effect of BV2-Exo. Furthermore, Notch1 was a directly targeting gene of exosomal miRNA-137. In conclusion, these results suggest that BV2-Exo alleviates ischemia-reperfusion brain injury through transporting exosomal miRNA-137. This study provides novel insight into microglial exosomes-based therapies for the treatment of ischemic brain injury.

M2 microglial small extracellular vesicles reduce glial scar formation via the miR-124/STAT3 pathway after ischemic stroke in mice

Rationale: Glial scars present a major obstacle for neuronal regeneration after stroke. Thus, approaches to promote their degradation and inhibit their formation are beneficial for stroke recovery. The interaction of microglia and astrocytes is known to be involved in glial scar formation after stroke; however, how microglia affect glial scar formation remains unclear. Methods: Mice were treated daily with M2 microglial small extracellular vesicles through tail intravenous injections from day 1 to day 7 after middle cerebral artery occlusion. Glial scar, infarct volume, neurological score were detected after ischemia. microRNA and related protein were examined in peri-infarct areas of the brain following ischemia. Results: M2 microglial small extracellular vesicles reduced glial scar formation and promoted recovery after stroke and were enriched in miR-124. Furthermore, M2 microglial small extracellular vesicle treatment decreased the expression of the astrocyte proliferation gene signal transducer and activator of transcription 3, one of the targets of miR-124, and glial fibrillary acidic protein and inhibited astrocyte proliferation both in vitro and in vivo. It also decreased Notch 1 expression and increased Sox2 expression in astrocytes, which suggested that astrocytes had transformed into neuronal progenitor cells. Finally, miR-124 knockdown in M2 microglial small extracellular vesicles blocked their effects on glial scars and stroke recovery. Conclusions: Our results showed, for the first time, that microglia regulate glial scar formation via small extracellular vesicles, indicating that M2 microglial small extracellular vesicles could represent a new therapeutic approach for stroke.

Revisiting Stem Cell-Based Clinical Trials for Ischemic Stroke

Stroke is the leading cause of serious long-term disability, significantly reducing mobility in almost half of the affected patients aged 65 years and older. There are currently no proven neurorestorative treatments for chronic stroke. To address the complex problem of restoring function in ischemic brain tissue, stem cell transplantation-based therapies have emerged as potential restorative therapies. Aligning with the major cell types found within the ischemic brain, stem-cell-based clinical trials for ischemic stroke have fallen under three broad cell lineages: hematopoietic, mesenchymal, and neural. In this review article, we will discuss the scientific rationale for transplanting cells from each of these lineages and provide an overview of published and ongoing trials using this framework.

Dexmedetomidine-up-regulated microRNA-381 exerts anti-inflammatory effects in rats with cerebral ischaemic injury via the transcriptional factor IRF4

Dexmedetomidine (Dex) possesses analgesic and anaesthetic values and reported being used in cerebral ischaemic injury therapeutics. Accumulating studies have determined the effect of microRNAs (miRNAs) on the cerebral ischaemic injury. Thus, the present study aimed to unravel the molecular mechanism of miR-381 and Dex in cerebral ischaemic injury. For this purpose, the cerebral ischaemic injury rat model was established by induction of middle cerebral artery occlusion (MCAO) and expression of miR-381 and IRF4 was determined. Thereafter, MCAO rats were treated with Dex, miR-381 mimic, miR-381 inhibitor and oe-IRF4 respectively, followed by evaluation of neurological function. Furthermore, neuron cells were isolated from the hippocampus of rats and subjected to oxygen-glucose deprivation (OGD). Then, OGD-treated neuron cells and primary neuron cells were examined by gain- and loss-of-function assay. Neuron cell apoptosis was detected using TUNEL staining and flow cytometry. The correlation between interferon regulatory factor 4 (IRF4) and interleukin (IL)-9 was detected. Our results showed down-regulated miR-38 and up-regulated IRF4 in MCAO rats. Besides, IRF4 was targeted by miR-381 in neuron cells. Dex and overexpressed miR-381, or silenced IRF4 improved the neurological function and inhibited neuron cell apoptosis in MCAO rats. Additionally, in MCAO rats, Dex was found to increase the miR-381 expression and reduced IRF4 expression to decrease the IL-9 expression, which suppressed the inflammatory response and cell apoptosis both in vivo and in vitro. Importantly, our study demonstrated that Dex elevated the expression of miR-381, which ultimately results in the inhibition of inflammation response in rats with cerebral ischaemic injury.

Endothelial progenitor cell transplantation alleviated ischemic brain injury via inhibiting C3/C3aR pathway in mice

Endothelial progenitor cell transplantation is a potential therapeutic approach in brain ischemia. However, whether the therapeutic effect of endothelial progenitor cells is via affecting complement activation is unknown. We established a mouse focal ischemia model (n = 111) and transplanted endothelial progenitor cells into the peri-infarct region immediately after brain ischemia. Neurological outcomes and brain infarct/atrophy volume were examined after ischemia. Expression of C3, C3aR and pro-inflammatory factors were further examined to explore the role of endothelial progenitor cells in ischemic brain. We found that endothelial progenitor cells improved neurological outcomes and reduced brain infarct/atrophy volume after 1 to 14 days of ischemia compared to the control (p < 0.05). C3 and C3aR expression in the brain was up-regulated at 1 day up to 14 days (p < 0.05). Endothelial progenitor cells reduced astrocyte-derived C3 (p < 0.05) and C3aR expression (p < 0.05) after ischemia. Endothelial progenitor cells also reduced inflammatory response after ischemia (p < 0.05). Endothelial progenitor cell transplantation reduced astrocyte-derived C3 expression in the brain after ischemic stroke, together with decreased C3aR and inflammatory response contributing to neurological function recovery. Our results indicate that modulating complement C3/C3aR pathway is a novel therapeutic target for the ischemic stroke.

Recombinant canine basic fibroblast growth factor-induced differentiation of canine bone marrow mesenchymal stem cells into voltage- and glutamate-responsive neuron-like cells

Introduction

Basic fibroblast growth factor (bFGF) is a promising cytokine in regenerative therapy for spinal cord injury. In this study, recombinant canine bFGF (rc-bFGF) was synthesized for clinical use in dogs, and the ability of rc-bFGF to differentiate canine bone marrow mesenchymal stem cells (BMSCs) into functional neurons was investigated.

Methods

The rc-bFGF was synthesized using a wheat germ cell-free protein synthesis system. The expression of rc-bFGF mRNA in the purification process was confirmed using a reverse transcription-polymerase chain reaction (RT-PCR). Western blotting was performed to confirm the antigenic property of the purified protein. To verify function of the purified protein, phosphorylation of extracellular signal-regulated kinase (ERK) was examined by in vitro assay using HEK293 cells. To compare the neuronal differentiation capacity of canine BMSCs in response to treatment with rc-bFGF, the cells were divided into the following four groups: control, undifferentiated, rh-bFGF, and rc-bFGF groups. After neuronal induction, the percentage of cells that had changed to a neuron-like morphology and the mRNA expression of neuronal markers were evaluated. Furthermore, to assess the function of the canine BMSCs after neuronal induction, changes in the intracellular Ca²⁺ concentrations after stimulation with KCl and l-glutamate were examined.

Results

The protein synthesized in this study was rc-bFGF and functioned as bFGF, from the results of RT-PCR, western blotting, and the expression of pERK in HEK293 cells. Canine BMSCs acquired a neuron-like morphology and expressed mRNAs of neuronal markers after neuronal induction in the rh-bFGF and the rc-bFGF groups. These results were more marked in the rc-bFGF group than in the other groups. Furthermore, an increase in intracellular Ca²⁺ concentrations was observed after the stimulation of KCl and l-glutamate in the rc-bFGF group, same as in the rh-bFGF group.

Conclusions

A functional rc-bFGF was successfully synthesized, and rc-bFGF induced the differentiation of canine BMSCs into voltage- and glutamate-responsive neuron-like cells. Our purified rc-bFGF may contribute, on its own, or in combination with canine BMSCs, to regenerative therapy for spinal cord injury in dogs.

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Functional rc-bFGF was successfully synthesized.

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rc-bFGF induced the differentiation of canine BMSCs into neuron-like cells.

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rc-bFGF may aid in regenerative therapy of spinal cord injury in dogs.

Application of Stem Cells in Stroke: A Multifactorial Approach

Stroke has a debilitating effect on the human body and a serious negative effect on society, with a global incidence of one in every six people. According to the World Health Organization, 15 million people suffer stroke worldwide each year. Of these, 5 million die and another 5 million are permanently disabled. Motor and cognitive deficits like hemiparesis, paralysis, chronic pain, and psychomotor and behavioral symptoms can persist long term and prevent the patient from fully reintegrating into society, therefore continuing to add to the costly healthcare burden of stroke. Regenerative medicine using stem cells seems to be a panacea for sequelae after stroke. Stem cell-based therapy aids neuro-regeneration and neuroprotection for neurological recovery in patients. However, the use of stem cells as a therapy in stroke patients still needs a lot of research at both basic and translational levels. As well as the mode of action of stem cells in reversing the symptoms not being clear, there are several clinical parameters that need to be addressed before establishing stem cell therapy in stroke, such as the type of stem cells to be administered, the number of stem cells, the timing of dosage, whether dose-boosters are required, the route of administration, etc. There are upcoming prospects of cell-free therapy also by using exosomes derived from stem cells. There are several ongoing pre-clinical studies aiming to answer these questions. Despite still being in the development stage, stem cell therapy holds great potential for neurological rehabilitation in patients suffering from stroke.

Farnesoid X receptor knockout protects brain against ischemic injury through reducing neuronal apoptosis in mice

Background

Farnesoid X receptor (FXR) is a nuclear receptor that plays a critical role in controlling cell apoptosis in diverse diseases. Previous studies have shown that knocking out FXR improved cardiac function by reducing cardiomyocyte apoptosis in myocardial ischemic mice. However, the role of FXR after cerebral ischemia remains unknown. In this study, we explored the effects and mechanisms of FXR knockout (KO) on the functional recovery of mice post cerebral ischemia-reperfusion.

Methods

Adult male C57BL/6 wild type and FXR KO mice were subjected to 90-min transient middle cerebral artery occlusion (tMCAO). The mice were divided into five groups: sham, wild-type tMCAO, FXR KO tMCAO, wild-type tMCAO treated with calcium agonist Bayk8644, and FXR KO tMCAO treated with Bayk8644. FXR expression was examined using immunohistochemistry and Western blot. Brain infarct and brain atrophy volume were examined at 3 and 14 days after stroke respectively. Neurobehavioral tests were conducted up to 14 days after stroke. The protein levels of apoptotic factors (Bcl-2, Bax, and Cleaved caspase-3) and mRNA levels of pro-inflammatory factors (TNF-α, IL-6, IL-1β, IL-17, and IL-18) were examined using Western blot and RT-PCR. TUNEL staining and calcium imaging were obtained using confocal and two-photon microscopy.

Results

The expression of FXR was upregulated after ischemic stroke, which is located in the nucleus of the neurons. FXR KO was found to reduce infarct volume and promote neurobehavioral recovery following tMCAO compared to the vehicle. The expression of apoptotic and pro-inflammatory factors decreased in FXR KO mice compared to the control. The number of NeuN⁺/TUNEL⁺ cells declined in the peri-infarct area of FXR KO mice compared to the vehicle. We further demonstrated that inhibition of FXR reduced calcium overload and addition of ionomycin could reverse this neuroprotective effect in vitro. What is more, in vivo results showed that enhancement of intracellular calcium concentrations could aggravate ischemic injury and reverse the neuroprotective effect of FXR KO in mice.

Conclusions

FXR KO can promote neurobehavioral recovery and attenuate ischemic brain injury, inflammatory release, and neuronal apoptosis via reducing calcium influx, suggesting its role as a therapeutic target for stroke treatments.

Triad3A displays a critical role in suppression of cerebral ischemic/reperfusion (I/R) injury by regulating necroptosis

Ischemic stroke is a major cause of death and disability worldwide. Necroptosis is known as a form of cell death, playing an essential role in regulating ischemia-induced brain injury. Triad3A is a ubiquitin ligase of the RING-in-between-RING family, and regulates necroptotic cell death under different pathological conditions, including neurodegenerative disorders. In the present study, the effects of Triad3A on experimental stroke were explored on a mouse model with middle cerebral artery occlusion (MCAO). The results indicated that Triad3A expression was markedly induced in the ischemic brain after MCAO operation. The neurons and microglia cells were the major cellular sources for Triad3A induction. Triad3A knockdown enhanced the infarction area, cell death, microglia activity, and the expression levels of pro-inflammatory markers including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, inducible nitric oxide synthase (iNOS), CD32 and CD68 in MCAO mice. Triad3A and necroptosis were triggered in mouse microglia cells treated with oxygen and glucose deprivation (OGD), and in TNFα-incubated mouse hippocampal neuronal cells treated with Z-VAD-fmk, known as a pan-caspase inhibitor. Moreover, Triad3A knockdown accelerated cell death in microglial cells and neurons under these stresses. Furthermore, pre-treatment with necroptosis inhibitor markedly inhibited the cell death promoted by Triad3A silence in brain of mice with MCAO operation, demonstrating that Triad3A could regulate necroptosis to meditate the progression of cerebral I/R injury. Collectively, these finding illustrated that Triad3A could be served as a potential target for stroke therapy.

Shuxuening injection facilitates neurofunctional recovery via down-regulation of G-CSF-mediated granulocyte adhesion and diapedesis pathway in a subacute stroke mouse model

Post-stroke neural damage is a serious health concern which does not yet have an effective treatment. We have shown previously that Shuxuening injection (SXNI), a Ginkgo biloba extract-based natural medicine, protects brain after an acute ischemic stroke, but its efficacy for post-stroke recovery is not known. This study was to investigate whether SXNI can improve the prognosis of stroke at a subacute phase. Mice with cerebral ischemia-reperfusion injury (CIRI) were established by middle cerebral artery occlusion (MCAO), and drugs or saline were injected by the tail vein every 12 h after reperfusion. The therapeutic effect of SXNI was evaluated by survival rate, modified neurologic severity scores (mNSS), open-field test, locomotive gait patterns, cerebral infarction volume, brain edema and histopathological changes. Subsequently, a combined method of RNA-seq and Ingenuity® Pathway Analysis (IPA) was performed to identify key targets and pathways of SXNI facilitating the prognosis of stroke in mouse brain. The results of the transcriptome analysis were verified by real time reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), western blot (WB) and immunohistochemistry (IHC). The experimental results showed that in the new subacute stroke model, SXNI markedly improves the survival rate, neurological and motor functions and histopathological changes, and significantly reduces cerebral infarction and edema volume. RNA-seq analysis of subacute stroke mice with or without SXNI (3 mL/kg) indicated 963 differentially expressed genes (DEGs) with a fold change ≥ 1.5 and a P-value ≤ 0.01. IPA analysis of DEGs showed that granulocyte adhesion and diapedesis ranked first in the pathway ranking, and the most critical gene regulated by SXNI was G-csf. Simultaneously, RT-PCR, ELISA, WB and IHC results demonstrated that SXNI not only obviously reduced the mRNA expression levels of key genes G-csf, Sele and Mac-1 in this pathway, but also significantly decreased the protein expression levels of G-CSF in serum and E-selectin and MAC-1 in brain tissues. In summary, our research suggested that SXNI can exert a remarkable neurofunctional therapeutic effect on stroke mice via down-regulating G-CSF to inhibit granulocyte adhesion and diapedesis. This study provides experimental evidence that SXNI may fulfill the need for stroke medicine targeting specifically at the recovery stage.

Bone Marrow-Derived NCS-01 Cells Advance a Novel Cell-Based Therapy for Stroke

Human mesenchymal stem cells have been explored for their application in cell-based therapies targeting stroke. Identifying cell lines that stand as safe, accessible, and effective for transplantation, while optimizing dosage, timing, and method of delivery remain critical translational steps towards clinical trials. Preclinical studies using bone marrow-derived NCS-01 cells show the cells' ability to confer functional recovery in ischemic stroke. Coculturing primary rat cortical cells or human neural progenitor cells with NCS-01 cells protects against oxygen-glucose deprivation. In the rodent middle cerebral artery occlusion model, intracarotid artery administration of NCS-01 cells demonstrate greater efficacy than other mesenchymal stem cells (MSCs) at improving motor and neurological function, as well as reducing infarct volume and peri-infarct cell loss. NCS-01 cells secrete therapeutic factors, including basic fibroblast growth factor and interleukin-6, while also demonstrating a potentially novel mechanism of extending filopodia towards the site of injury. In this review, we discuss recent preclinical advancements using in vitro and in vivo ischemia models that support the transplantation of NCS-01 in human stroke trials. These results, coupled with the recommendations put forth by the consortium of Stem cell Therapeutics as an Emerging Paradigm for Stroke (STEPS), highlight a framework for conducting preclinical research with the ultimate goal of initiating clinical trials.

Silencing the lncRNA Maclpil in pro-inflammatory macrophages attenuates acute experimental ischemic stroke via LCP1 in mice

Long noncoding RNAs (lncRNA) expression profiles change in the ischemic brain after stroke, but their roles in specific cell types after stroke have not been studied. We tested the hypothesis that lncRNA modulates brain injury by altering macrophage functions. Using RNA deep sequencing, we identified 73 lncRNAs that were differentially expressed in monocyte-derived macrophages (MoDMs) and microglia-derived macrophages (MiDMs) isolated in the ischemic brain three days after stroke. Among these, the lncRNA, GM15628, is highly expressed in pro-inflammatory MoDMs but not in MiDMs, and are functionally related to its neighbor gene, lymphocyte cytosolic protein 1 (LCP1), which plays a role in maintaining cell shape and cell migration. We termed this lncRNA as Macrophage contained LCP1 related pro-inflammatory lncRNA, Maclpil. Using cultured macrophages polarized by LPS, M(LPS), we found that downregulation of Maclpil in M(LPS) decreased pro-inflammatory gene expression while promoting anti-inflammatory gene expression. Maclpil inhibition also reduced the migration and phagocytosis ability of MoDMs by inhibiting LCP1. Furthermore, adoptive transfer of Maclpil silenced M(LPS), reduced ischemic brain infarction, improved behavioral performance and attenuated penetration of MoDMs in the ischemic hemisphere. We conclude that by blocking macrophage, Maclpil protects against acute ischemic stroke by inhibiting neuroinflammation.

P2Y6 receptor inhibition aggravates ischemic brain injury by reducing microglial phagocytosis

Introduction

Clearance of damaged cells and debris is beneficial for the functional recovery after ischemic brain injury. However, the specific phagocytic receptor that mediates microglial phagocytosis after ischemic stroke is unknown.

Aim

To investigate whether P2Y6 receptor‐mediated microglial phagocytosis is beneficial for the debris clearance and functional recovery after ischemic stroke.

Results

The expression of the P2Y6 receptor in microglia increased within 3 days after transient middle cerebral artery occlusion. Inhibition of microglial phagocytosis by the selective inhibitor MRS2578 enlarged the brain atrophy and edema volume after ischemic stroke, subsequently aggravated neurological function as measured by modified neurological severity scores and Grid walking test. MRS2578 treatment had no effect on the expression of IL‐1α, IL‐1β, IL‐6, IL‐10, TNF‐α, TGF‐β, and MPO after ischemic stroke. Finally, we found that the expression of myosin light chain kinase decreased after microglial phagocytosis inhibition in the ischemic mouse brain, which suggested that myosin light chain kinase was involved in P2Y6 receptor‐mediated phagocytosis.

Conclusion

Our results indicate that P2Y6 receptor‐mediated microglial phagocytosis plays a beneficial role during the acute stage of ischemic stroke, which can be a therapeutic target for ischemic stroke.

MicroRNA-181c provides neuroprotection in an intracerebral hemorrhage model

Apoptosis is an important factor during the early stage of intracerebral hemorrhage. MiR-181c plays a key regulatory role in apoptosis. However, whether miR-181c is involved in apoptosis of prophase cells after intracerebral hemorrhage remains unclear. Therefore, in vitro and in vivo experiments were conducted to test this hypothesis. In vivo experiments: collagenase type VII was injected into the basal ganglia of adult Sprague-Dawley rats to establish an intracerebral hemorrhage model. MiR-181c mimic or inhibitor was injected in situ 4 hours after intracerebral hemorrhage. Neurological functional defects (neurological severity scores) were assessed 1, 7, and 14 days after model establishment. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling and western blot assay were conducted 14 days after model establishment. In vitro experiments: PC12 cells were cultured under oxygen-glucose deprivation, and hemins were added to simulate intracerebral hemorrhage in vitro. MiR-181c mimic or inhibitor was added to regulate miR-181c expression. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, luciferase reporter system, and western blot assay were performed. Experimental results revealed differences in miR-181c expression in brain tissues of both patients and rats with cerebral hemorrhage. In addition, in vitro experiments found that miR-181c overexpression could upregulate the Bcl-2/Bax ratio to inhibit apoptosis, while inhibition of miR-181c expression could reduce the Bcl-2/Bax ratio and aggravate apoptosis of cells. Regulation of apoptosis occurred through the phosphoinositide 3 kinase (PI3K)/Akt pathway by targeting of phosphatase and tensin homolog deleted on chromosome ten (PTEN). Higher miR-181c overexpression correlated with lower neurological severity scores, indicating better recovery of neurological function. In conclusion, miR-181c affects the prognosis of intracerebral hemorrhage by regulating apoptosis, and these effects might be directly mediated and regulated by targeting of the PTEN\PI3K/Akt pathway and Bcl-2/Bax ratio. Furthermore, these results indicated that miR-181c played a neuroprotective role in intracerebral hemorrhage by regulating apoptosis of nerve cells, thus providing a potential target for the prevention and treatment of intracerebral hemorrhage. Testing of human serum was authorized by the Ethics Committee of China Medical University (No. 2012-38-1) on February 20, 2012. The protocol was registered with the Chinese Clinical Trial Registry (Registration No. ChiCTR-COC-17013559). The animal study was approved by the Institutional Animal Care and Use Committee of China Medical University (approval No. 2017008) on March 8, 2017.

A Comparison of Intracerebral Transplantation of RMNE6 Cells and MSCs on Ischemic Stroke Models

Background

Cell therapy using stem cells is promising for stroke patients; however, stem cell therapy faces many problems. RMNE6 cells, a new stem cell line, are superior to other stem cell lines. Mesenchymal stem cells (MSCs) appear to be a promising candidate for stroke patients. In the current study, we determined the therapeutic effects of RMNE6 cells on a middle cerebral artery occlusion (MCAO) model of rats and identified the differences between RMNE6 cells and MSCs with respect to therapeutic effects.

Material and Methods

RMNE6 and Enhanced green fluorescent protein (EGFP)-labeled MSCs were transplanted into the ischemic brains of MCAO rats. The behavior of rats was examined using the rotarod test with neuroradiologic assessment using magnetic resonance imaging (MRI). Four weeks after cell transplantation, the rats were investigated by immunofluorescence staining to explore the fates of the graft cells.

Result

After transplantation, RMNE6 cells and MSCs survived and migrated toward the injured area without differentiation. There was tumorigenesis in the brains transplanted with RMNE6 cells. Cell transplantation had no effects on the size of the ischemic volume. The behavior of the model animals showed no significant improvement.

Conclusion

MSCs are still the preferred cells for cell replacement in stroke therapy, while RMNE6 cells need to be modified.

Translating intracarotid artery transplantation of bone marrow-derived NCS-01 cells for ischemic stroke: Behavioral and histological readouts and mechanistic insights into stem cell therapy

The present study used in vitro and in vivo stroke models to demonstrate the safety, efficacy, and mechanism of action of adult human bone marrow‐derived NCS‐01 cells. Coculture with NCS‐01 cells protected primary rat cortical cells or human neural progenitor cells from oxygen glucose deprivation. Adult rats that were subjected to middle cerebral artery occlusion, transiently or permanently, and subsequently received intracarotid artery or intravenous transplants of NCS‐01 cells displayed dose‐dependent improvements in motor and neurological behaviors, and reductions in infarct area and peri‐infarct cell loss, much better than intravenous administration. The optimal dose was 7.5 × 10⁶ cells/mL when delivered via the intracarotid artery within 3 days poststroke, although therapeutic effects persisted even when administered at 1 week after stroke. Compared with other mesenchymal stem cells, NCS‐01 cells ameliorated both the structural and functional deficits after stroke through a broad therapeutic window. NCS‐01 cells secreted therapeutic molecules, such as basic fibroblast growth factor and interleukin‐6, but equally importantly we observed for the first time the formation of filopodia by NCS‐01 cells under stroke conditions, characterized by cadherin‐positive processes extending from the stem cells toward the ischemic cells. Collectively, the present efficacy readouts and the novel filopodia‐mediated mechanism of action provide solid lab‐to‐clinic evidence supporting the use of NCS‐01 cells for treatment of stroke in the clinical setting.

EPO regulates neuroprotective Transmembrane BAX Inhibitor-1 Motif-containing (TMBIM) family members GRINA and FAIM2 after cerebral ischemia-reperfusion injury

BACKGROUND AND PURPOSE

Transmembrane BAX Inhibitor-1 Motif-containing (TMBIM) family members exert inhibitory activities in apoptosis and necroptosis. FAIM2 (TMBIM-2) is neuroprotective against murine focal ischemia and is regulated by erythropoietin (EPO). Similar to FAIM2, GRINA (TMBIM-3) is predominantly expressed in the brain. The role of GRINA in transient brain ischemia, its potential synergistic effects with FAIM2 and its regulation by EPO treatment were assessed.

METHODS

We performed transient (30 min) middle cerebral artery occlusion (tMCAo) followed by 72 h of reperfusion in GRINA-deficient (GRINA-/-), FAIM2-deficient (FAIM2-/-), double-deficient (GRINA-/-FAIM2-/-) and wildtype littermates (WT) mice. We administered EPO or saline 0, 24 and 48 h after tMCAo. We subjected primary murine cortical neurons (pMCN) of all mouse strains to oxygen-glucose deprivation (OGD) after GRINA and/or FAIM2 gene transfection.

RESULTS

Compared to wildtype controls GRINA deficiency led to a similar increase in infarct volumes as FAIM2 deficiency (p < .01). We observed the highest neurological deficits and largest infarct sizes in double-deficient mice. EPO administration upregulated GRINA and FAIM2 mRNA levels in wildtype littermates. EPO decreased infarct sizes and abrogated neurological impairments in wildtype controls. GRINA and/or FAIM2 deficient mice showed increased expression levels of cleaved-caspase 3 and of pro-apoptotic BAX mRNA. Further, caspase 8 was upregulated in FAIM2-/- and caspase 9 in GRINA-/- mice. Overexpression of GRINA and FAIM2 in wildtype and in double deficient pMCN decreased cell death rate after OGD.

CONCLUSIONS

GRINA and FAIM2 are highly expressed in the brain and convey EPO-mediated neuroprotection after ischemic stroke involving different caspases.

PAI-1 but Not PAI-2 Gene Deficiency Attenuates Ischemic Brain Injury After Experimental Stroke

After stroke, secondary brain damage is influenced by the extent of fibrin clot formation. This is counteracted by the endogenous fibrinolysis. Of major interest are the key players of the fibrinolytic plasminogen activator system including the urokinase plasminogen activator (uPA), the tissue-type plasminogen activator (tPA), and their endogenous inhibitors plasminogen activator inhibitor 1 (PAI-1) and PAI-2. The role of PAI-1 in brain injury is well established, whereas the importance of PAI-2 is unknown at present. The objectives of the present were twofold: first, to characterize the time-dependent cerebral mRNA expression of the plasminogen activator system (PAS) after brain ischemia and second, to investigate the impact of PAI-1 and PAI-2 on brain infarct volume using gene-deficient mice. Adult C57Bl/6J mice were subjected to unilateral transient middle cerebral artery occlusion (MCAO) followed by reperfusion for 3, 24, 72, or 120 h. Quantitative PCR revealed that brain mRNA expression levels of the PAS components, and particularly of PAI-1 (237-fold) and PAI-2 (19-fold), peaked at 24 h after stroke. Accordingly, PAI-1 plasma activity was strongly increased. Brain infarct volume in TTC (2,3,5-triphenyltetrazolium chloride)-stained brain sections was significantly smaller 24 h after MCAO in PAI-1-deficient mice (- 31%), but not in PAI-2-deficient mice (- 6%). Thus, endogenous upregulation of PAI-1, but not of PAI-2, might contribute to increased brain damage after acute ischemic stroke. The present study therefore shows that PAI-2 is induced by brain ischemia, but does not play an important or relevant role for secondary brain damage after brain injury.

Circular RNA TLK1 Aggravates Neuronal Injury and Neurological Deficits after Ischemic Stroke via miR-335-3p/TIPARP

Circular RNAs (circRNAs) are expressed at high levels in the brain and are involved in various CNS diseases. However, the potential role of circRNAs in ischemic stroke-associated neuronal injury remains largely unknown. Here, we investigated the important functions of circRNA TLK1 (circTLK1) in this process. The levels of circTLK1 were significantly increased in brain tissues in a mouse model of focal cerebral ischemia and reperfusion. Knockdown of circTLK1 significantly decreased infarct volumes, attenuated neuronal injury, and improved neurological deficits. Furthermore, circTLK1 functioned as an endogenous miR-335-3p sponge to inhibit miR-335-3p activity, resulting in the increase of 2,3,7,8-tetrachlorodibenzo-p-dioxin-inducible poly (ADP-ribose) polymerase expression and a subsequent exacerbation of neuronal injury. Clinical studies confirmed increased levels of circTLK1 in the plasma of patients with acute ischemic stroke (59 males and 12 females). Our findings reveal a detrimental role of circTLK1 in ischemic brain injury.SIGNIFICANCE STATEMENT The extent of neuronal injury after brain ischemia is a primary factor determining stroke outcomes. However, the molecular switches that control the death of ischemic neurons are poorly understood. While our previous studies indicated the involvement of circRNAs in ischemic stroke, the potential role of circRNAs in neuronal injury remains largely unknown. The levels of circTLK1 were significantly increased in the brain tissue and plasma isolated from animal models of ischemic stroke and patients. Knockdown of circTLK1 significantly decreased infarct volumes, attenuated neuronal injury, and improved subsequent long-term neurological deficits. To our knowledge, these results provide the first definitive evidence that circTLK1 is detrimental in ischemic stroke.

Hypothalamic impairment underlying heat intolerance in pregnant mice

Pregnant women are vulnerable to heat stroke reactions caused by high environmental temperatures. Heat intolerance is associated with hypothalamic impairment. Here, we aim to ascertain whether pregnancy causes heat intolerance by inducing hypothalamic impairment in mice. In the heated groups, mice were exposed to whole body heating (WBH; 41.2 °C for 1 h) in an environment-controlled chamber. Then, they were returned to normal room temperature (26 °C) immediately after WBH. In the hyperbaric oxygen therapy (HBO₂T) groups, mice were exposed to 100% O₂ at 2.0 atm absolute (ATA) for 4 h immediately post-WBH. Mice that survived after 4 h of WBH were considered survivors. Here, we show that when pregnant mice underwent non-HBO₂T (21% O₂ at 1.0 ATA for 4 h) after WBH, the survival rate was 4/20, and the core temperature at 4 h post-WBH was 31.2 ± 0.2 °C. Both the survival rate and core temperature of HBO₂T pregnant mice (10/10 and 35.2 ± 0.3 °C, respectively) were significantly greater than those in non-HBO₂T pregnant mice. Compared to non-HBO₂T heated mice, the HBO₂T heated mice exhibited lower neurological severity scores, reduced hypothalamic neuronal damage, fewer apoptotic cells, reduced multiorgan damage scores, and lower hypothalamic levels of proinflammatory cytokines and nitrogen and oxygen radical species. Compared to non-HBO₂T heated mice, the HBO₂T-treated heated mice had significantly higher hypothalamic-pituitary-adrenal axis activity (evidenced by higher serum levels of both adrenocorticotrophic hormone and corticosterone). In conclusion, pregnancy induces heat intolerance by inducing hypothalamic impairment in mice. Additionally, HBO₂T protects against heat intolerance in pregnant mice by preserving hypothalamic integrity.

Bone marrow stromal cells transplantation promotes the resolution and recanalization of deep vein thrombosis in rabbits through regulating macrophage infiltration and angiogenesis

This study aims to validate whether bone marrow stromal cells (BMSCs) transplantation could promote the resolution and recanalization of deep vein thrombosis (DVT) and to explore the underlying mechanism. The right hind femoral vein was embolized to establish the DVT rabbit model. BMSCs from New Zealand white rabbits were isolated and identified, and then injected into DVT rabbits. After that, the extent of angiogenesis was determined by the amount of capillaries that were positive for antibody against vWF. Macrophage infiltration was measured by immunohistochemistry with F4/80 antibody. M1 or M2 macrophages were identified as F4/80 + CD11c ⁺ or F4/80 + CD206 ⁺ cells by using flow cytometry analysis, respectively. BMSCs were successfully isolated and identified. BMSCs transplantation promotes macrophage infiltration and angiogenesis in DVT rabbits. BMSCs transplantation causes M1/M2 polarization, altered cytokine production and increased monocyte chemotactic protein 1 (MCP-1) protein expression in DVT rabbits. However, injection of MCP-1 protein not only reversed the effects of BMSCs transplantation on macrophage infiltration and angiogenesis, but also reversed the effects of BMSCs transplantation on M1/M2 polarization and cytokine production in DVT rabbits. BMSCs transplantation promotes the resolution and recanalization of DVT in rabbits through regulating macrophage infiltration and angiogenesis, the underlying mechanism is associated with MCP-1 expression.

Silencing of SNHG12 Enhanced the Effectiveness of MSCs in Alleviating Ischemia/Reperfusion Injuries via the PI3K/AKT/mTOR Signaling Pathway

Previous studies have reported that the long non-coding RNA SNHG12 (lncRNA SNHG12) plays a critical role in regulating the function of mesenchymal stem cells (MSCs); however, the effect of lncRNA SNHG12 on MSCs in injured brain tissue has rarely been reported. We studied the effect and mechanism of lncRNA SNHG12-modified mesenchymal stem cells (MSCs) in treating brain injuries caused by ischemia/reperfusion (I/R). I/R treated rat brain microvascular endothelial cells (BMECs) were co-cultured with MSCs or I/R pretreated MSCs. Next, BMEC proliferation was detected by using CCK-8 and EdU assays, and cell apoptosis was determined by using flow cytometry and the Hoechst staining method. Autophagy of BMECs was determined using immunofluorescence and expression of associated pathway proteins were measured by western blotting. Moreover, BMEC proliferation, apoptosis, and autophagy were also determined after the BMECs had been co-cultured with shSNHG12-MSCs. In addition, a rat model of middle cerebral artery occlusion (MCAO) was used to further confirm the findings obtained with cells. I/R treatment significantly decreased the proliferation of BMECs, but increased their levels of SNHG12 expression, apoptosis, and autophagy. However, co-culturing of BMECs with MSCs markedly alleviated the reduction in BMEC proliferation and the increases in BMEC apoptosis and autophagy, as well as the phosphorylation of PI3K, AKT, and mTOR proteins in BMECs that had been induced by I/R. Furthermore, shSNHG12 remarkably enhanced the effects of MSCs. In addition, an injection MSCs reduced the infarct areas and rates of cell apoptosis in MACO rats, and reduced the phosphorylation of PI3K, AKT, and mTOR proteins. Moreover, shSNHG12 enhanced the ameliorative effect of MSCs in treating brain injuries in the MACO rats. In conclusion, silencing of SNHG12 enhanced the effects of MSCs in reducing apoptosis and autophagy of BMECs by activating the PI3K/AKT/mTOR signaling pathway.

ZIPK mediates endothelial cell contraction through myosin light chain phosphorylation and is required for ischemic-reperfusion injury

The paracellular gap formed by endothelial cell (EC) contraction is fundamental for endothelium permeability, but the mechanism underlying EC contraction has yet to be determined. Here, we identified the zipper-interacting protein kinase (ZIPK) as the kinase for EC contraction and myosin light chain (MLC) phosphorylation. Inhibition of ZIPK activity by pharmacological inhibitors and small interfering RNAs led to a significant decrease in the mono- and diphosphorylation of MLCs along with a contractile response to thrombin, suggesting an essential role of ZIPK in EC paracellular permeability. To assess the role of ZIPK in vivo, we established mouse lines with conditional deletion of Zipk gene. The endothelium-specific deletion of Zipk led to embryonic lethality, whereas the UBC-Cre^ERT2-mediated deletion of Zipk by tamoxifen induction at adulthood caused no apparent phenotype. The induced deletion of Zipk significantly inhibited ischemia-reperfusion-induced blood-brain barrier dysfunction and neuronal injuries from middle cerebral artery occlusion and reperfusion, as evidenced by reduced infarct and edema volume, attenuated Evans blue dye leakage, and improved neuronal behavior. We thus concluded that ZIPK and its phosphorylation of MLC were required for EC contraction and ischemic neuronal injuries. ZIPK may be a prospective therapeutic target for stroke.-Zhang, Y., Zhang, C., Zhang, H., Zeng, W., Li, S., Chen, C., Song, X., Sun, J., Sun, Z., Cui, C., Cao, X., Zheng, L., Wang, P., Zhao, W., Zhang, Z., Xu, Y., Zhu, M., Chen, H. ZIPK mediates endothelial cell contraction through myosin light chain phosphorylation and is required for ischemic-reperfusion injury.

Modern Concepts in Regenerative Therapy for Ischemic Stroke: From Stem Cells for Promoting Angiogenesis to 3D-Bioprinted Scaffolds Customized via Carotid Shear Stress Analysis

Ischemic stroke is associated with a tremendous economic and societal burden, and only a few therapies are currently available for the treatment of this devastating disease. The main therapeutic approaches used nowadays for the treatment of ischemic brain injury aim to achieve reperfusion, neuroprotection and neurorecovery. Therapeutic angiogenesis also seems to represent a promising tool to improve the prognosis of cerebral ischemia. This review aims to present the modern concepts and the current status of regenerative therapy for ischemic stroke and discuss the main results of major clinical trials addressing the effectiveness of stem cell therapy for achieving neuroregeneration in ischemic stroke. At the same time, as a glimpse into the future, this article describes modern concepts for stroke prevention, such as the implantation of bioprinted scaffolds seeded with stem cells, whose 3D geometry is customized according to carotid shear stress.

Stroke Dysbiosis Index (SDI) in Gut Microbiome Are Associated With Brain Injury and Prognosis of Stroke

Background: Significant dysbiosis occurs in the gut microbiome of stroke patients. Condensing these broad, complex changes into one index would greatly facilitate the clinical usage of gut microbiome data. Here, we formulated a gut microbiota index in patients with acute ischemic stroke based on their gut microbiota dysbiosis patterns and tested whether the index was correlated with brain injury and early outcome.

Methods: A total of 104 patients with acute ischemic stroke and 90 healthy individuals were recruited, and their gut microbiotas were compared and to model a Stroke Dysbiosis Index (SDI), which representing stroke-associated dysbiosis patterns overall. Another 83 patients and 70 controls were recruited for validation. The association of SDI with stroke severity (National Institutes of Health Stroke Scale [NIHSS] score) and outcome (modified Rankin scale [mRS] score: favorable, 0–2; unfavorable, >2) at discharge was also assessed. A middle cerebral artery occlusion (MCAO) model was used in human flora-associated (HFA) animals to explore the causal relationship between gut dysbiosis and stroke outcome.

Results: Eighteen genera were significantly different between stroke patients and healthy individuals. The SDI formula was devised based on these microbiome differences; SDI was significantly higher in stroke patients than in healthy controls. SDI alone discriminated stroke patients from controls with AUCs of 74.9% in the training cohort and 84.3% in the validation cohort. SDI was significantly and positively correlated with NIHSS score on admission and mRS score at discharge. Logistic regression analysis showed that SDI was an independent predictor of severe stroke (NIHSS ≥8) and early unfavorable outcome (mRS >2). Mice receiving fecal transplants from high-SDI patients developed severe brain injury with elevated IL-17⁺ γδ T cells in gut compared to mice receiving transplants from low-SDI patients (all P < 0.05).

Conclusions: We developed an index to measure gut microbiota dysbiosis in stroke patients; this index was significantly correlated with patients' outcome and was causally related to outcome in a mouse model of stroke. Our model facilitates the potential clinical application of gut microbiota data in stroke and adds quantitative evidence linking the gut microbiota to stroke.

Protective effects of mesenchymal stem cells overexpressing extracellular regulating kinase 1/2 against stroke in rats

OBJECTIVE

Although transplantation of bone marrow-derived mesenchymal stem cells (MSCs) has shown beneficial effects on stroke, lower survival of MSCs limits effects. Extracellular regulating kinase 1/2 signaling (ERK1/2) is crucial for cell survival, differentiation, and proliferation. This study was designed to explore whether MSCs modified by over-expressing ERK1/2 may reinforce beneficial effects on stroke in rats.

METHODS

rat MSCs transfected with ERK1/2 and empty lentivirus to generate MSCs overexpressing ERK1/2 (ERK/MSCs) and MSCs (as a control), respectively. In vitro, ERK/MSCs were plated and exposed to glutamate-induced condition, and viability of ERK/MSCs was measured. Furthermore, neural induction of ERK/MSCs was investigated in vitro. Cerebral ischemic rats were induced by occluding middle cerebral artery, and then were stereotaxically injected into ipsilateral right lateral ventricle with ERK/MSCs or MSCs 3 days after stroke and survived for 7 or 14 days after injection.

RESULTS

ERK/MSCs showed better viability in physiological and glutamate-induced neurotoxic conditions compared to MSCs. After neural induction, more neurons were be differentiated from ERK/MSCs than from MSCs. After transplantation, more numbers of grafted cells and improved functional recovery were observed in ERK/MSCs-treated rats compared with MSCs-treated rats. Compared with MSCs treatment, ERK/MSCs treatment significantly increased proliferation of neural stem cells in the subventricle zone (SVZ) and the MAP2/nestin double-labeled cells adjacent to the SVZ, enhanced the numbers of reactive astrocytes while suppressed microglial activation. Besides, TNF-α level was elevated in ERK/MSCs-treated rats.

CONCLUSION

ERK/MSCs transplantation showed better functional recovery after stroke in rats, likely in part through enhancing survival of MSCs and possibly by modulating the proliferation, neuronal de-differentiation and neuroinflammation.

Inhibition of miRNA-27b enhances neurogenesis via AMPK activation in a mouse ischemic stroke model

Stroke is a leading cause of death and disability, but treatment options remain limited. Recent studies have suggested that cerebral ischemia‐induced neurogenesis plays a vital role in post‐stroke repair. Overactivation of AMP‐activated protein kinase (AMPK), a master sensor of energy balance, has been reported to exacerbate neuron apoptosis, but the role of chronic AMPK stimulus in post‐stroke recovery remains unclear. MicroRNAs have emerged as regulators of neurogenesis and have been reported to be involved in neurological function. In this study, we verified that miR‐27b directly targets AMPK and inhibits AMPK expression. In cultured neural stem cells, miR‐27b inhibitor improved proliferation and differentiation via the AMPK signaling pathway, but did not have an obvious effect on cell viability under oxygen and glucose deprivation conditions. In a mouse middle cerebral artery occlusion model, administration of miR‐27b inhibitor significantly enhanced behavioral function recovery and spatial memory. Up‐regulation of neurogenesis was observed both in the subventricular zone and in the hippocampal dentate gyrus. Collectively, our data suggest that miR‐27b inhibition promotes recovery after ischemic stroke by regulating AMPK activity. These findings may facilitate the development of novel therapeutic strategies for stroke.

Myosin1f-mediated neutrophil migration contributes to acute neuroinflammation and brain injury after stroke in mice

Background

During the acute stroke phase, neutrophils from the peripheral blood are first to arrive in the ischemic brain, which then attracts other immune cells that exacerbate neuroinflammation in the ischemic tissue. Myosin1f was reported to specifically mediate neutrophil migration in the peripheral tissues, but whether it plays a critical role in the neuroinflammatory response after ischemic stroke remains unknown. In this study, we aim to test the hypothesis that myosin1f-mediated neutrophil migration is critical in acute neuroinflammation induced by ischemic stroke.

Methods

Myosin1f ^−/− and wild type (WT) mice were subjected to transient middle cerebral artery occlusion (MCAO). To determine which cells determine myosin1f’s transmigration ability, bone marrow transplantation, neutrophil depletion, and adoptive neutrophil transfer were performed. The myosin1f RNA level was assessed in peripheral neutrophils by reverse transcription polymerase chain reaction (RT-PCR) at 1 day and 3 days after stroke. The infiltrating neutrophils were quantified by immunofluorescence staining and FACS at 72 h after reperfusion.

Results

The myosin1f ^−/− mice had significantly smaller infarctions than the myosin1f ^+/+ mice. Bone marrow transplantation from myosin1f ^−/− mice to recipient mice also had smaller infarctions compared to animals receiving bone marrow from myosin1f ^+/+ mice. By performing neutrophil depletion and adoptive transfer, we confirmed that myosin1f acts mainly in circulating neutrophils. RT-PCR showed that myosin1f gene expression was increased in the circulating blood neutrophils at 3 days after ischemia. The confocal immunostaining and FACS results confirmed that fewer neutrophils infiltrated into the ischemic brain in myosin1f ^−/− mice compared to WT mice.

Conclusions

Myosin1f determines neutrophil migration into the ischemic hemisphere, which directly affects stroke outcome.

Electronic supplementary material

The online version of this article (10.1186/s12974-019-1465-9) contains supplementary material, which is available to authorized users.

Dl-3-N-butylphthalide promotes angiogenesis and upregulates sonic hedgehog expression after cerebral ischemia in rats

INTRODUCTION

Dl-3-N-butylphthalide (NBP), a small molecule drug used clinically in the acute phase of ischemic stroke, has been shown to improve functional recovery and promote angiogenesis and collateral vessel circulation after experimental cerebral ischemia. However, the underlying molecular mechanism is unknown.

AIMS

To explore the potential molecular mechanism of angiogenesis induced by NBP after cerebral ischemia.

RESULTS

NBP treatment attenuated body weight loss, reduced brain infarct volume, and improved neurobehavioral outcomes during focal ischemia compared to the control rats (P < 0.05). NBP increased the number of CD31⁺ microvessels, the number of CD31⁺ /BrdU⁺ proliferating endothelial cells, and the functional vascular density (P < 0.05). Further study demonstrated that NBP also promoted the expression of vascular endothelial growth factor and angiopoietin-1 (P < 0.05), which was accompanied by upregulated sonic hedgehog expression in astrocytes in vivo and in vitro.

CONCLUSION

NBP treatment promoted the expression of vascular endothelial growth factor and angiopoietin-1, induced angiogenesis, and improved neurobehavioral recovery. These effects were associated with increased sonic hedgehog expression after NBP treatment. Our results broadened the clinical application of NBP to include the later phase of ischemia.

MicroRNA-126 Regulates Angiogenesis and Neurogenesis in a Mouse Model of Focal Cerebral Ischemia

Studies demonstrate that microRNA-126 plays a critical role in promoting angiogenesis. However, its effects on angiogenesis following ischemic stroke are unclear. Here, we explored the effect of microRNA-126-3p and microRNA-126-5p on angiogenesis and neurogenesis after brain ischemia. We demonstrated that both microRNA (miRNA)-126-3p and microRNA-126-5p increased the proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) compared with the scrambled miRNA control (p < 0.05). Transferring microRNA-126 into a mouse middle cerebral artery occlusion model via lentivirus, we found that microRNA-126 overexpression increased the number of CD31⁺/BrdU⁺ (5-bromo-2'-deoxyuridine-positive) proliferating endothelial cells and DCX⁺/BrdU⁺ neuroblasts in the ischemic mouse brain, improved neurobehavioral outcomes (p < 0.05), and reduced brain atrophy volume (p < 0.05) compared with control mice. Western blot results showed that AKT and ERK signaling pathways were activated in the lentiviral-microRNA-126-treated group (p < 0.05). Both PCR and western blot results demonstrated that tyrosine-protein phosphatase non-receptor type 9 (PTPN9) was decreased in the lentiviral-microRNA-126-treated group (p < 0.05). Dual-luciferase gene reporter assay also showed that PTPN9 was the direct target of microRNA-126-3p and microRNA-126-5p in the ischemic brain. We demonstrated that microRNA-126-3p and microRNA-126-5p promoted angiogenesis and neurogenesis in ischemic mouse brain, and further improved neurobehavioral outcomes. Our mechanistic study further showed that microRNA-126 mediated angiogenesis through directly inhibiting its target PTPN9 and activating AKT and ERK signaling pathways.

Hyperbaric Oxygen Protects Against Cerebral Damage in Permanent Middle Cerebral Artery Occlusion Rats and Inhibits Autophagy Activity

BACKGROUND

To investigate the effects of hyperbaric oxygen (HBO) on brain damage and autophagy levels in a rat model of middle cerebral artery occlusion.

METHODS

Neurologic injury and infarcted areas were evaluated according to the modified neurological severity score and 2,3,5-triphenyltetrazolium chloride staining. Western blots were used to determine beclin1, caspase-3 and fodrin1 protein expression. Beclin1 protein expression (an autophagy marker), positive terminal dUTP nick-end labeling (TUNEL) staining (an apoptosis marker) and positive propidium iodide (PI) staining (a necrosis marker) were detected by immunofluorescence.

RESULTS

Our results indicated that HBO could decrease the infarct volume and speed up the recovery of the neurological deficit scores in ischemic rats. Beclin1 was down-regulated after HBO treatment. HBO treatment inhibited fodrin1 protein expression and decreased the number of PI-positive cells. HBO also down-regulated caspase-3 and decreased the number of TUNEL-positive cells.

CONCLUSION

Cerebral ischemia caused early neuronal death due to necrosis, followed by delayed neuronal death due to apoptosis. Consequently, autophagy might be involved in all processes of ischemia. HBO could protect the brain against ischemic injury, and the possible mechanisms might be correlated with decreased autophagy activity and decreased apoptosis and necrosis levels.

The spleen may be an important target of stem cell therapy for stroke

Stroke is the most common cerebrovascular disease, the second leading cause of death behind heart disease and is a major cause of long-term disability worldwide. Currently, systemic immunomodulatory therapy based on intravenous cells is attracting attention. The immune response to acute stroke is a major factor in cerebral ischaemia (CI) pathobiology and outcomes. Over the past decade, the significant contribution of the spleen to ischaemic stroke has gained considerable attention in stroke research. The changes in the spleen after stroke are mainly reflected in morphology, immune cells and cytokines, and these changes are closely related to the stroke outcomes. Autonomic nervous system (ANS) activation, release of central nervous system (CNS) antigens and chemokine/chemokine receptor interactions have been documented to be essential for efficient brain-spleen cross-talk after stroke. In various experimental models, human umbilical cord blood cells (hUCBs), haematopoietic stem cells (HSCs), bone marrow stem cells (BMSCs), human amnion epithelial cells (hAECs), neural stem cells (NSCs) and multipotent adult progenitor cells (MAPCs) have been shown to reduce the neurological damage caused by stroke. The different effects of these cell types on the interleukin (IL)-10, interferon (IFN), and cholinergic anti-inflammatory pathways in the spleen after stroke may promote the development of new cell therapy targets and strategies. The spleen will become a potential target of various stem cell therapies for stroke represented by MAPC treatment.

Intravenous administration of human adipose-derived stem cells ameliorates motor and cognitive function for intracerebral hemorrhage mouse model

Even today, intracerebral hemorrhage (ICH) is a major cause of death and disabilities. Rehabilitation is preferentially applied for functional recovery although its effect is limited. Recent studies have suggested that intravenous administration of mesenchymal stem cells would improve the post-ICH neurological deficits. Human adipose-derived stem cells (hADSCs) have been established in our laboratory. We aimed to evaluate the therapeutic efficacy of the hADSCs on the post-ICH neurological deficits using a clinical-relevant ICH mouse model. We also evaluated immune responses to clarify the underlying mechanisms. The hADSCs expressed MSC markers at high levels. The hADSCs administration into the ICH-bearing mice improved the neurological deficits during the subacute phases, which was shown by neurobehavioral experiments. Besides, the hADSC administration decreased the number of CD11⁺CD45⁺ cells and increased the proportion of CD86⁺ and Ly6C⁺ cells in the ICH lesions. In summary, intravenous administration of hADSCs during the acute phase improved ICH-induced neurological deficits during the subacute phase because of the suppression of acute inflammation mediated by CD11⁺CD45⁺ subpopulations. Our data suggest that hADSCs can be served as a novel strategy for ICH treatment.

Bone Marrow Stromal Cells With Exercise and Thyroid Hormone Effect on Post-Stroke Injuries in Middle-aged Mice

Introduction:

Based on our previous findings, the treatment of stem cells alone or in combination with thyroid hormone (T₃) and mild exercise could effectively reduce the risk of stroke damage in young mice. However, it is unclear whether this treatment is effective in aged or middle-aged mice. Therefore, this study designed to assess whether combination of Bone Marrow Stromal Cells (BMSCs) with T₃ and mild treadmill exercise can decrease stroke complications in middle-aged mice.

Methods:

Under laser Doppler flowmetry monitoring, transient focal cerebral ischemia was produced by right Middle Cerebral Artery Occlusion (MCAO) for 45 min followed by 7 days of reperfusion in middle-aged mice. BMSCs (1×10⁵) were injected into the right cerebral ventricle 24 h after MCAO, followed by daily injection of triiodothyronine (T₃) (20 μg/100 g/d SC) and 6 days of running on a treadmill. Infarct size, neurological function, apoptotic cells and expression levels of Glial Fibrillary Acidic Protein (GFAP) were evaluated 1 week after stroke.

Results:

Post-ischemic treatment with BMSCs or with T₃ and or mild treadmill exercise alone or in combination did not significantly change neurological function, infarct size, and apoptotic cells 7 days after ischemia in middle-aged mice (P>0.05). However, the expression of GFAP significantly reduced after treatment with BMSCs and or T₃ (P<0.01).

Conclusion:

Our findings indicate that post-stroke treatment BMSCs with exercise and thyroid hormone cannot reverse neuronal damage 7 days after ischemia in middle-aged mice. These findings further support that age is an important variable in stroke treatment

Reliability of behavioral tests in the middle cerebral artery occlusion model of rat

Stroke is one of the leading causes of death and disability worldwide, and its incidence is increasing. To overcome impairment from stroke, translational research for developing new therapeutic technologies has been conducted and middle cerebral artery occlusion (MCAo) in rat is the representative model. Since recovery from neurological impairment in contralateral limbs caused by brain damage is the major goal of treatment, behavioral tests that assess the relevant function are used. To determine therapeutic effect, obtaining reliable results of behavioral assessment is a prerequisite. However, studies on the reliability of behavioral tests in the MCAo rat model and necessity of prior training have not yet been reported. In this study, the authors investigate relative and absolute inter-rater reliabilities of modified neurological severity score (mNSS), cylinder test, and grid-walking test before training and repeated training every week until the reliability of results reached a satisfactory level. The training included repeated learning of the scoring system and decreasing disagreements among the raters. For MCAo modeling, adult male Sprague-Dawley rats were subjected to 90 min of transient MCAo. Six raters conducted behavioral tests via observation of video-recording on sham-operated and MCAo model rats at 3 or 7 days after the intervention. An independent experimenter randomly numbered each video clip to blind the experiment. The results of reliabilities were unacceptable before training and improved to a satisfactory level after 6 weeks of training in all of the tests. In conclusion, mNSS, cylinder test, and grid-walking test on the MCAo rat model are reliable evaluation methods after conducting appropriate training.