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

Astrocyte-derived MMP-9 is a key mediator of pseudorabies virus penetration of the blood-brain barrier and tight junction disruption

Pseudorabies virus (PRV) infection leads to viral encephalitis and neurological damage in mice, causing significant neurological symptoms and brain damage. This study aimed to investigate the cellular mechanisms of PRV-induced encephalopathy and the role of matrix metalloproteinase-9 (MMP-9) in blood-brain barrier (BBB) disruption. We found that PRV infection increased the number of astrocytes and induced a phenotypic shift from the A2 to the A1 subtype, which was associated with increased secretion of MMP-9. MMP-9 was identified as a critical mediator of PRV-induced BBB disruption, as it degrades collagen VI, leading to BBB damage. PRV was shown to penetrate the BBB via a paracellular pathway, and MMP-9 deletion reversed this damage, mitigating tight junction injury. Additionally, PRV infection caused an "inflammatory storm" in the central nervous system (CNS), with increased levels of the chemokines CCL-3, CCL-4, and CCL-5; the cytokines IL-6 and IL-18; and TNF-α. The expression of INF-γ was significantly decreased. In conclusion, PRV infection disrupts the BBB and induces an inflammatory response in the CNS, with MMP-9 playing a key role in mediating BBB damage. These findings provide insights into the pathogenesis of PRV-induced encephalopathy and potential therapeutic targets for viral encephalitis.

Impaired Resting-State Functional Connectivity in Cerebral Autosomal-Dominant Arteriopathy, Subcortical Infarcts, and Leukoencephalopathy Mutant Mice

BACKGROUND

Cerebral autosomal-dominant arteriopathy, subcortical infarcts, and leukoencephalopathy is the most prevalent monogenic inherited cause of cerebral small vessel disease. Despite its prevalence, there is currently no proven therapy to prevent or reverse the progression of the disease.

METHODS

This study aimed to characterize the functional integrity of long white matter tracts in cerebral autosomal-dominant arteriopathy, subcortical infarcts, and leukoencephalopathy transgenic mice expressing R169C mutant Notch3 (Notch3R169C) compared with wild type littermates (Notch3WT), both with and without a superimposed focal white matter lesion in the corpus callosum, utilizing optical resting-state functional connectivity imaging alongside behavioral examinations. In addition, we examined the efficacy of tocotrienol, a neuroprotective derivative of vitamin E derived from palm oil, which has shown promise in preventing white matter disease progression in clinical trials involving patients with small vessel disease.

RESULTS

At baseline, resting-state interhemispheric and intrahemispheric functional connectivity was significantly lower in Notch3R169C than in Notch3WT (P=0.004), and the grid walk test revealed a higher number of foot faults in the Notch3R169C group compared with Notch3WT. Sex did not interact with the genotype on the primary outcomes. Introducing a lesion in the corpus callosum compromised functional connectivity and behavior outcomes in both genotypes to a similar extent; lesion volumes did not differ between the genotypes. Tocotrienol treatment did not show any protective effect on any end point.

CONCLUSIONS

These data show impaired resting-state functional connectivity and increased foot faults in the Notch3R169C mutant model of cerebral autosomal-dominant arteriopathy, subcortical infarcts, and leukoencephalopathy. Future work will aim to test therapeutic or preventive interventions in cerebral autosomal-dominant arteriopathy, subcortical infarcts, and leukoencephalopathy mutants using these measures.

Intracerebral Transplantation of Autologous Mesenchymal Stem Cells Improves Functional Recovery in a Rat Model of Chronic Ischemic Stroke

While treatments exist for the acute phase of stroke, there are limited options for patients with chronic infarcts and long-term disability. Allogenic mesenchymal stem cells (alloMSCs) show promise for the treatment of stroke soon after ischemic injury. There is, however, no information on the use of autologous MSCs (autoMSCs), delivered intracerebrally in rats with a chronic infarct. In this study, rats underwent middle cerebral artery occlusion (MCAO) to induce stroke followed by bone marrow aspiration and MSC expansion in a closed bioreactor. Four weeks later, brain MRI was obtained and autoMSCs (1 × 106, 2.5 × 106 or 5 × 106; n = 6 each) were stereotactically injected into the peri-infarct and compared to controls (MCAO only; MCAO + PBS; n = 6-9). Behavior was assessed using the modified neurological severity score (mNSS). For comparison, an additional cohort of MCAO rats were implanted with 2.5 × 106 alloMSCs generated from a healthy rat. All doses of autoMSCs produced significant improvement (54-70%) in sensorimotor function 60 days later. In contrast, alloMSCs improved only 31.7%, similar to that in PBS controls 30%. Quantum dot-labeled auto/alloMSCs were found exclusively at the implantation site throughout the post-transplantation period with no tumor formation on MRI or Ki67 staining of engrafted MSCs. Small differences in stroke volume and no differences in corpus callosum width were observed after MSC treatment. Stroke-induced glial reactivity in the peri-infarct was long-lasting and unabated by auto/alloMSC transplantation. These studies suggest that intracerebral transplantation of autoMSCs as compared to alloMSCs may be a promising treatment in chronic stroke.

Netrin-1 binding to UNC5b improves post-stroke neuronal ferroptosis via AMPK-BACH1 pathway

Ferroptosis contributes to neuronal destruction after ischemic stroke which may be improved by inhibiting BTB domain and CNC homolog 1 (BACH1), a recently recognized ferroptosis facilitator. Axon guidance molecule netrin-1 (Ntn1) functions in neuroprotection against ischemic insult by engaging into its receptor of uncoordinated-5 homolog B (UNC5b) via adenosine 5'-monophosphate-activated protein kinase (AMPK), which potentially binds to BACH1. Whether Ntn1/UNC5b regulates post-stroke ferroptosis through AMPK-BACH1 pathway remains unclear. Ntn1 supplementation and UNC5b knockdown by siRNA were performed in photo-thrombosis stroke mice and oxygen-glucose deprivation-treated HT22 neurons. AMPK inhibitor BAY3827 and BACH1 activator Leptomycin B (LMB) were administrated. Ferroptosis was determined by ferroptosis-associated proteins (FSP1, GPX4 and ACSL4), Fe2+, malondialdehyde and mitochondrial morphology. BACH1 and p-AMPK/AMPK as well as the interaction between them were examined by Western blot and co-immunoprecipitation. Neuronal ferroptosis and the protein levels of BACH1 and p-AMPK were increased after photo-thrombosis and oxygen-glucose deprivation. Ntn1 supplementation or UNC5b knockdown relieved neuronal ferroptosis and neurological impairment with downregulated BACH1 and upregulated p-AMPK, nonetheless, UNC5b knockdown prevented the beneficial role of Ntn1. Both BAY3827 and LMB could reverse the change of ferroptosis caused by Ntn1 where BAY3827 inhibited the effects of Ntn1 to p-AMPK and BACH1 while LMB only inhibited the effect of Ntn1 to BACH1 without p-AMPK, suggesting BACH1 was regulated by AMPK. Co-immunoprecipitation verified that AMPK could physically bind to BACH1. Our results demonstrate UNC5b-evoked neuronal ferroptosis post stroke, and favor that Ntn1 improves post-stroke ferroptosis by its interaction with UNC5b via the AMPK-BACH1 pathway.

MMP-9 inhibitor SB-3CT improves neurological outcomes in ischemic stroke mice by modulation of astrocytic lipid metabolism

The acute phase of ischemic stroke is marked by a surge in matrix metalloproteinase-9 (MMP-9) activity. While integral to natural repair processes, MMP-9 exacerbates injury by breaking down the blood-brain barrier (BBB) and promoting edema and inflammation. MMP-9 is predominantly secreted by inflammatory cells such as neutrophils, macrophages and microglia soon after stroke onset. In this study we investigated the effects of MMP-9 inhibition via SB-3CT on astrocytic lipid metabolism, and its potential to enhance neuronal survival and recovery following ischemic stroke. Mice were subjected to transient middle cerebral artery occlusion (tMCAO) for 60 min, mice then were injected with SB-3CT (25 mg/kg, i.v.). On D3 post tMCAO, neurological outcomes were assessed, and whole brains were collected for analysis. Lipidomic analysis of brain tissue showed that SB-3CT treatment significantly restrained astrocytic cholesterol metabolism by modulating the sphingolipid and glycerophospholipid pathways. Specifically, SB-3CT reduced ceramide accumulation and promoted an increase in neuroprotective hexosylceramides, leading to enhanced neuronal survival and synaptic integrity. In addition, SB-3CT treatment reduced astrocytic and microglial reactivity, thereby mitigating neuroinflammation. In order to optimize the timing and dosage of MMP-9 inhibition to maximize the therapeutic efficacy, tMCAO mice were given three injections of SB-3CT on D0, D2 and D4 within 7 days after modeling. We found that prolonged MMP-9 inhibition alleviated astrogliosis, concurrently impaired neurological recovery and inhibited angiogenesis. These results demonstrate the critical role of lipid metabolism in MMP-9-mediated brain injury and the potential of SB-3CT as a therapeutic strategy for ischemic stroke by targeting astrocytic lipid metabolism.

Kuanxiong Aerosol Attenuates Ischemic Stroke Injury via Modulation of the TRPV1 Channel

OBJECTIVE

To evaluate the therapeutic effects of Kuanxiong Aerosol (KXA) on ischemic stroke with reperfusion and elucidate the underlying pharmacological mechanisms.

METHODS

In vivo pharmacological effects on ischemic stroke with reperfusion was evaluated using the transient middle cerebral artery occlusion (t-MCAO) mice model. To evaluate short-term outcome, 30 mice were randomly divided into vehicle group (n=15) and KXA group (n=15). Mice in KXA and vehicle groups received 69 mg KXA and vehicle for 1 day, respectively. To evaluate long-term outcome, 35 mice were randomly divided into sham group (n=5), vehicle group (n=15), and KXA group (n=15). Mice in KXA and vehicle groups received 69 mg KXA and vehicle for 7 days, respectively. Pathological changes in the brain were observed by 2,3,5-triphenyltetrazolium chloride or Nissl stainings, and behavioral assessments, including the Modified Neurologic Severity Score, Bederson score, rotarod test, and adhesive removal test were conducted. The penetration ability of KXA and KX (KXA without propellants) through the blood-brain barrier was assessed both in vitro using a transwell model and in vivo. Furthermore, in vitro effects of KX (5, 10, and 20 µL/L) on oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced injury, transient receptor potential vanilloid type 1 (TRPV1) modulation, calcium influx, and mitochondrial function were explored through Western blot, CCK-8 assay, JC-1 staining, calcium imaging, adenosine triphosphate (ATP) and antioxidant measurements.

RESULTS

In in vivo experiments, KXA reduced brain infarct volume and neuron loss in t-MCAO mice. Behavioral assessments showed marked improvement in the neurological deficit of t-MCAO mice with KXA treatment (P<0.05 or P<0.01). Additionally, in vitro findings indicated that KX ameliorated OGD/R-induced injury through TRPV1 channel modulation. KX increased cell viability in OGD/R-treated SH-SY5Y cells and prevented OGD/R-induced calcium overload by downregulating TRPV1 expression and constraining calcium influx through TRPV1 (P<0.05 or P<0.01). Furthermore, KXA maintained the membrane potential and function of mitochondria in OGD/R-treated SH-SY5Y cells.

CONCLUSIONS

KXA could attenuate ischemic stroke injury through TRPV1 channel modulation, indicating its potential as a promising therapeutic option for stroke in clinical practice.

Paraoxonase 1 ameliorates neurological symptoms and motor coordination impairment caused by cerebral ischemia-reperfusion injury

The anti-atherosclerotic effects of high-density lipoprotein (HDL) prevent the onset of cerebral infarction and provide cerebroprotective effects against ischemia-reperfusion injury. These inhibitory effects have been attributed to its antioxidant, anti-inflammatory, and antithrombotic properties. However, pharmacotherapeutic strategies to clinically realize these effects have not been demonstrated. Therefore, we aimed to develop paraoxonase 1 (PON1), a hydrolytic enzyme associated with HDL that exhibits antioxidant and anti-inflammatory effects, as a novel therapeutic agent against ischemia-reperfusion injury in cerebral infarction. We established a method to extract PON1 from human plasma with high purity and recovery while maintaining its activity. The purified PON1 exhibited antioxidant activity against human-derived LDL and HDL. Furthermore, PON1 actively suppressed the oxidation chain reaction by hydrolyzing lipid peroxides. The HDL-binding ability of PON1 was evaluated based on its activity in fractionated HDL from mice administered PON1 intravenously, which showed that most intravenously administered PON1 specifically bound to HDL. The cerebroprotective effect of intravenously administered PON1 was assessed using a mouse middle cerebral artery ischemia-reperfusion model by measuring infarct volume, long-term neurological scores, and walking time on a rotarod. Administration of PON1 after reperfusion reduced infarct volume 24 h after ischemia-reperfusion. Additionally, daily administration of PON1 for three days significantly improved neurological scores and walking time by approximately one month. Analysis of gene arrays in brain tissue indicated that PON1 suppresses biological functions and pathways associated with oxidative stress, inflammation, vascular dysfunction, thrombosis, and fibrosis. PON1 enhances the cerebroprotective effects of HDL and is a potential candidate for acute stroke therapy.

The temporal dynamic of bradykinin type 2 receptor effects reveals its neuroprotective role in the chronic phase of cerebral and retinal ischemic injury

The activation of the bradykinin type 2 receptor is intricately involved in acute post-ischemic inflammatory responses. However, its precise role in different stages of ischemic injury, especially in the chronic phase, remains unclear. Following simultaneous cerebral and retinal ischemia, bradykinin type 2 receptor knockout mice and their controls were longitudinally monitored for 35 days via magnetic resonance imaging, fundus photography, fluorescein angiography, behavioral assessments, vascular permeability measurements, and immunohistochemistry, as well as glycemic status assessments. Without impacting the lesion size, bradykinin type 2 receptor deficiency reduced acute cerebral vascular permeability preventing the loss of pericytes and tight junctions. In the chronic phase of ischemia, however, it resulted in increased astrogliosis and cortical neuronal loss, as well as higher functional deficits. The retinal findings demonstrated a similar pattern. Bradykinin type 2 receptor deficiency delayed, but exacerbated the development of retinal necrosis, increased subacute vascular permeability, and promoted retinal ganglion cell loss in the chronic phase of ischemia. This investigation sheds light on the temporal dynamic of bradykinin type 2 receptor effects in ischemia, pointing to a therapeutic potential in the subacute and chronic phases of ischemic injury.

LncRNA Tug1 Regulates Post-Stroke Microglial Pyroptosis via PINK1/Parkin-Mediated Mitophagy

Microglia, the central nervous system's primary immune cells, play a key role in the progression of cerebral ischemic stroke, particularly through their involvement in pyroptosis. The long non-coding RNA taurine up-regulated gene 1 (Tug1) is elevated during ischemic stroke and is critical in driving post-stroke neuroinflammation. However, the underlying molecular mechanisms remain unclear. This study explores the biological role of Tug1 and its potential mechanisms in regulating pyroptosis in microglia. We utilized an in vivo photothrombosis (PT) mice model and an in vitro oxygen-glucose deprivation and reperfusion (OGD/R) BV2 cell model to explore the mechanisms underlying ischemic stroke. Initially, we assessed the expression levels of Tug1 in the OGD/R model in vitro and the PT model in vivo. Subsequently, we investigated the impact of Tug1 on microglial pyroptosis by knocking down Tug1, silencing the PTEN-induced putative kinase 1 (Pink1) expression, and employing the mitophagy inhibitor mdivi-1. Tug1 exacerbated microglial pyroptosis by inhibiting mitophagy in both in vivo and in vitro models. The increase in mitophagy observed following Tug1 knockdown was reversed by either silencing Pink1 expression or using the mitophagy inhibitor mdivi-1. This reversal resulted in exacerbated pyroptosis and worsened neurological damage. Further mechanistic studies revealed that Tug1 knockdown significantly reduced microglial pyroptosis and alleviated neuronal damage by enhancing PINK1/Parkin-mediated mitophagy. For the first time, this study reveals that Tug1 promotes hypoxia-induced microglial pyroptosis by inhibiting PINK1/Parkin-mediated mitophagy, potentially providing a promising therapeutic target for ischemic inflammatory injury.

New TIPARP inhibitor rescues mitochondrial function and brain injury in ischemic stroke

Ischemic stroke is a high-mortality disease that urgently requires new therapeutic strategies. Insufficient cerebral blood supply can induce poly (ADP-ribose) polymerase (PARP) activation and mitochondrial dysfunction, leading to tissue damage and motor dysfunction. We demonstrate that the expression of TCDD inducible PARP (TIPARP) is elevated in ischemic stroke patients and mice. Knockdown of Tiparp reduces brain infarction and promotes recovery of motor function in ischemic stroke mice. A rationally designed TIPARP inhibitor, XG-04-B1, promotes repair of brain injury and recovery of motor function in ischemic stroke mice. Mechanistically, XG-04-B1 increases neuronal plasticity and inhibits astrocyte activation in ischemic stroke mice. In addition, eukaryotic translation initiation factor 3 subunit B (EIF3B) is a direct target of TIPARP. TIPARP interacts with EIF3B through nucleoplasmic redistribution, leading to mitochondrial dysfunction. Knockdown of Tiparp and inhibition of TIPARP via XG-04-B1 restore mitochondrial homeostasis in ischemic stroke mice. Taken together, TIPARP activation contributes to mitochondrial dysfunction and subsequent brain injury, and is therefore a promising therapeutic target for stroke.

M1 Microglia-Derived Exosomes Promote A1 Astrocyte Activation and Aggravate Ischemic Injury via circSTRN3/miR-331-5p/MAVS/NF-κB Pathway

Background

After ischemic stroke (IS), microglia and astrocytes undergo polarization, transforming into a pro-inflammatory phenotype (M1 or A1). According to previous studies, exosomes might play an important role in the interplay between M1 microglia and A1 astrocytes after IS.

Methods

We used the microglial oxygen-glucose deprivation/reperfusion (OGD/R) model and ultracentrifugation to extract M1 microglial exosomes (M1-exos). Subsequently, we identified circSTRN3 enriched in exosomes through RNA sequencing and detected the role of circSTRN3 in astrocyte activation based on bioinformatics analysis, immunofluorescence, Western blotting, and polymerase chain reaction analysis. We validated these findings in the middle cerebral artery occlusion/reperfusion (MCAO/R) model of adult male C57BL/6J mice. Finally, we confirmed the correlation among circSTRN3, miR-331-5p, and stroke severity score in exosomes isolated from peripheral blood of IS patients.

Results

Our findings revealed that M1-exos promoted A1 astrocyte activation. CircSTRN3 was abundant in M1-exos, which could sponge miR-331-5p to affect mitochondrial antiviral signaling protein (MAVS), activate NF-κB pathway, and participate in A1 astrocyte activation. In addition, overexpressed circSTRN3 augmented the infarct size and neurological dysfunction in MCAO/R models, while miR-331-5p mimics reversed the effect. Furthermore, circSTRN3 in IS patients was positively correlated with stroke severity score (R 2 = 0.83, P < 0.001), while miR-331-5p demonstrated a negative correlation with the same score (R 2 = 0.81, P < 0.001).

Conclusion

Taken together, our research indicated that circSTRN3 from M1-exos could promote A1 astrocyte activation and exacerbate ischemic brain injury via miR331-5p/MAVS/NF-κB axis.

Activation of GPR30 Ameliorates Cerebral Ischemia-Reperfusion Injury by Suppressing Ferroptosis Through Nrf2/GPX4 Signaling Pathway

The newly identified estrogen receptor, G protein-coupled receptor 30 (GPR30), is prevalent in the brain and has been shown to provide significant neuroprotection. Recent studies have linked ferroptosis, a newly characterized form of programmed cell death, closely with cerebral ischemia-reperfusion injury (CIRI), highlighting it as a major contributing factor. Consequently, our research aimed to explore the potential of GPR30 targeting in controlling neuronal ferroptosis and lessening CIRI impacts. Results indicated that GPR30 activation not only improved neurological outcomes and decreased infarct size in a mouse model but also lessened iron accumulation and malondialdehyde formation post-middle cerebral artery occlusion (MCAO). This protective effect extended to increased levels of Nrf2 and GPX4 proteins. Similar protective results were replicated in PC12 cells subjected to Oxygen Glucose Deprivation and Reoxygenation (OGD/R) using the GPR30-specific agonist G1. Importantly, inhibition of Nrf2 with ML385 curtailed the neuroprotective effects of GPR30 activation, suggesting that GPR30 mitigates CIRI primarily through inhibition of neuronal ferroptosis via upregulation of Nrf2 and GPX4.

MiR-30c-5p-Targeted Regulation of GNAI2 Improves Neural Function Injury and Inflammation in Cerebral Ischemia-Reperfusion Injury

MiRNAs are related to neuronal proliferation and apoptosis following cerebral ischemia-reperfusion injury (CIRI). This study focused on miR-30c-5p in the disease. An oxygen-glucose deprivation/re-oxygenation (OGD/R) model was prepared in HT22 cells and transfected to overexpress miR-30c-5p and G Protein Subunit Alpha I2 (GNAI2) respectively or co-transfected to silence miR-30c-5p and GNAI2. Meanwhile, a middle cerebral artery occlusion (MCAO) model was constructed in mice, and miR-30c-5p and GNAI2 were silenced in vivo simultaneously. The mice were evaluated for neurological damage, apoptosis, and inflammation. HT22 cells were tested for cytotoxicity, proliferation, apoptosis, and inflammatory factors. The interaction between miR-30c-5p and GNAI2 was predicted, analyzed, and confirmed. MiR-30c-5p was found to be downregulated in both experimental models. miR-30c-5p reduced lactate dehydrogenase production, inflammatory response, inhibit apoptosis, and enhanced neuronal proliferation, while GNAI2 overexpression showed the opposite results. Downregulated miR-30c-5p worsened neurological function, apoptosis, and inflammation of MCAO mice while silencing GNAI2 attenuated the influence of downregulated miR-30c-5p. MiR-30c-5p can improve neuronal apoptosis and inflammatory response caused by CIRI and is neuroprotective by targeting GNAI2, providing a new target for treating CIRI.

Striatal Blood Flow Changes by Middle Cerebral Artery Occlusion and Its Effect on Neurological Deficits in Mice

OBJECTIVE

We attempted to record the regional cerebral blood flow (CBF) simultaneously at various regions of the cerebral cortex and the striatum during middle cerebral artery (MCA) occlusion and to evaluate neurological deficits and infarct formation.

METHODS

In male C57BL/6J mice, CBF was recorded in three regions including the ipsilateral cerebral cortex and the striatum with laser Doppler flowmeters, and the origin of MCA was occluded with a monofilament suture for 15-90 min. After 48 h, neurological deficits were evaluated, and infarct was examined by triphenyltetrazolium chloride (TTC) staining.

RESULTS

CBF decrease in the striatum was approximately two-thirds of the MCA-dominant region of the cortex during MCA occlusion. The characteristic CBF fluctuation because of spontaneously occurred spreading depolarization observed throughout the cortex was not found in the striatum. Ischemic foci with slight lower staining to TTC were found in the ipsilateral striatum in MCA-occluded mice for longer than 30 min (n = 54). Twenty-nine among 64 MCA-occluded mice exhibited neurological deficits even in the absence of apparent infarct with minimum staining to TTC in the cortex, and the severity of neurological deficits was not correlated with the size of the cortical infarct.

CONCLUSION

Neurological deficits might be associated with the ischemic striatum rather than with cortical infarction.

Lipidomic analysis identifies long-chain acylcarnitine as a target for ischemic stroke

INTRODUCTION

Lipid metabolism dysfunction is widely involved in the pathological process of acute ischemic stroke (AIS). The coordination of lipid metabolism between neurons and astrocytes is of great significance. However, the full scope of lipid dynamic changes and the function of key lipids during AIS remain unknown. Hence, identifying lipid alterations and characterizing their key roles in AIS is of great importance.

METHODS

Untargeted and targeted lipidomic analyses were applied to profile lipid changes in the ischemic penumbra and peripheral blood of transient middle cerebral artery occlusion (tMCAO) mice as well as the peripheral blood of AIS patients. Infarct volume and neurological deficits were assessed after tMCAO. The cell viability and dendritic complexity of primary neurons were evaluated by CCK8 assay and Sholl analysis. Seahorse, MitoTracker Green, tetramethyl rhodamine methyl ester (TMRM), 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) and MitoSOX were used as markers of mitochondrial health. Fluorescent and isotopic free fatty acid (FFA) pulse-chase assays were used to track FFA flux in astrocytes.

RESULTS

Long-chain acylcarnitines (LCACs) were the lipids with the most dramatic changes in the ischemic penumbra and peripheral blood of tMCAO mice. LCACs were significantly elevated on admission in AIS patients and associated with poor outcomes in AIS patients. Increasing LCACs through a bolus administration of palmitoylcarnitine amplified stroke injury, while decreasing LCACs by overexpressing carnitine palmitoyltransferase 2 (CPT2) ameliorated stroke injury. Palmitoylcarnitine aggravated astrocytic mitochondrial damage after OGD/R, while CPT2 overexpression in astrocytes ameliorated cocultured neuron viability. Further study revealed that astrocytes stimulated by OGD/R liberated FFAs from lipid droplets into mitochondria to form LCACs, resulting in mitochondrial damage and lowered astrocytic metabolic support and thereby aggravated neuronal damage.

CONCLUSION

LCACs could accumulate and damage neurons by inducing astrocytic mitochondrial dysfunction in AIS. LCACs play a crucial role in the pathology of AIS and are novel promising diagnostic and prognostic biomarkers for AIS.

A role for astrocytic insulin-like growth factor I receptors in the response to ischemic insult

Increased neurotrophic support, including insulin-like growth factor I (IGF-I), is an important aspect of the adaptive response to ischemic insult. However, recent findings indicate that the IGF-I receptor (IGF-IR) in neurons plays a detrimental role in the response to stroke. Thus, we investigated the role of astrocytic IGF-IR on ischemic insults using tamoxifen-regulated Cre deletion of IGF-IR in glial fibrillary acidic protein (GFAP) astrocytes, a major cellular component in the response to injury. Ablation of IGF-IR in astrocytes (GFAP-IGF-IR KO mice) resulted in larger ischemic lesions, greater blood-brain-barrier disruption and more deteriorated sensorimotor coordination. RNAseq detected increases in inflammatory, cell adhesion and angiogenic pathways, while the expression of various classical biomarkers of response to ischemic lesion were significantly increased at the lesion site compared to control littermates. While serum IGF-I levels after injury were decreased in both control and GFAP-IR KO mice, brain IGF-I mRNA expression show larger increases in the latter. Further, greater damage was also accompanied by altered glial reactivity as reflected by changes in the morphology of GFAP astrocytes, and relative abundance of ionized calcium binding adaptor molecule 1 (Iba 1) microglia. These results suggest a protective role for astrocytic IGF-IR in the response to ischemic injury.

Ca2+ oscillation in vascular smooth muscle cells control myogenic spontaneous vasomotion and counteract post-ischemic no-reflow

Ischemic stroke produces the highest adult disability. Despite successful recanalization, no-reflow, or the futile restoration of the cerebral perfusion after ischemia, is a major cause of brain lesion expansion. However, the vascular mechanism underlying this hypoperfusion is largely unknown, and no approach is available to actively promote optimal reperfusion to treat no-reflow. Here, by combining two-photon laser scanning microscopy (2PLSM) and a mouse middle cerebral arteriolar occlusion (MCAO) model, we find myogenic vasomotion deficits correlated with post-ischemic cerebral circulation interruptions and no-reflow. Transient occlusion-induced transient loss of mitochondrial membrane potential (ΔΨm) permanently impairs mitochondria-endoplasmic reticulum (ER) contacts and abolish Ca2+ oscillation in smooth muscle cells (SMCs), the driving force of myogenic spontaneous vasomotion. Furthermore, tethering mitochondria and ER by specific overexpression of ME-Linker in SMCs restores cytosolic Ca2+ homeostasis, remotivates myogenic spontaneous vasomotion, achieves optimal reperfusion, and ameliorates neurological injury. Collectively, the maintaining of arteriolar myogenic vasomotion and mitochondria-ER contacts in SMCs, are of critical importance in preventing post-ischemic no-reflow.

Treatment with β-sitosterol ameliorates the effects of cerebral ischemia/reperfusion injury by suppressing cholesterol overload, endoplasmic reticulum stress, and apoptosis

β-Sitosterol is a type of phytosterol that occurs naturally in plants. Previous studies have shown that it has anti-oxidant, anti-hyperlipidemic, anti-inflammatory, immunomodulatory, and anti-tumor effects, but it is unknown whether β-sitosterol treatment reduces the effects of ischemic stroke. Here we found that, in a mouse model of ischemic stroke induced by middle cerebral artery occlusion, β-sitosterol reduced the volume of cerebral infarction and brain edema, reduced neuronal apoptosis in brain tissue, and alleviated neurological dysfunction; moreover, β-sitosterol increased the activity of oxygen- and glucose-deprived cerebral cortex neurons and reduced apoptosis. Further investigation showed that the neuroprotective effects of β-sitosterol may be related to inhibition of endoplasmic reticulum stress caused by intracellular cholesterol accumulation after ischemic stroke. In addition, β-sitosterol showed high affinity for NPC1L1, a key transporter of cholesterol, and antagonized its activity. In conclusion, β-sitosterol may help treat ischemic stroke by inhibiting neuronal intracellular cholesterol overload/endoplasmic reticulum stress/apoptosis signaling pathways.

Absence in CX3CR1 receptor signaling promotes post-ischemic stroke cognitive function recovery through suppressed microglial pyroptosis in mice

BACKGROUND

Post-stroke cognitive impairment (PSCI) is a major source of morbidity and mortality after stroke, but the pathological mechanisms remain unclear. Previous studies have demonstrated that the CX3CR1 receptor plays a crucial role in maintaining an early protective microenvironment after stroke, but whether it persistently influences cognitive dysfunction in the chronic phase requires further investigation.

METHODS

Mouse was used to establish a middle cerebral artery occlusion (MCAO)/reperfusion model to study PSCI. Cognitive function was assessed by the Morris water maze (MWM) and the novel object recognition test. Neurogenesis was assessed by immunofluorescence staining with Nestin+ /Ki67+ and DCX+ /BrdU+ double-positive cells. The cerebral damage was monitored by [18 F]-DPA-714 positron emission tomography, Nissel, and TTC staining. The pyroptosis was histologically, biochemically, and electron microscopically examined.

RESULTS

Upon MCAO, at 28 to 35 days, CX3CR1 knockout (CX3CR1-/- ) mice had better cognitive behavioral performance both in MWM and novel object recognition test than their CX3CR1+/- counterparts. Upon MCAO, at 7 days, CX3CR1-/- mice increased the numbers of Nestin+ /Ki67+ and DCX+ /BrdU+ cells, and meanwhile it decreased the protein expression of GSDMD, NLRP3 inflammasome subunit, caspase-1, mature IL-1β/IL-18, and p-P65 in the hippocampus as compared with CX3CR1+/- mice. In addition, CX3CR1-/- mice could reverse infarct volume in the hippocampus region post-stroke.

CONCLUSION

Our study demonstrated that CX3CR1 gene deletion was beneficial to PSCI recovery. The mechanism might lie in inhibited pyroptosis and enhanced neurogenesis. CX3CR1 receptor may serve as a therapeutic target for improving the PSCI.

A new multi-parameter imaging platform for in vivo drug efficacy evaluation of ischemic stroke

Ischemic stroke with high incidence and disability rate severely endangers human health. Current clinical treatment strategies are quite limited, new drugs for ischemic stroke are urgently needed. However, most existing methods for the efficacy evaluation of new drugs possess deficiencies of divorcing from the true biological context, single detection indicator and complex operations, leading to evaluation biases and delaying drug development process. In this work, leveraging the advantages of fluorescence imaging with non-invasive, real-time, in-situ, high selectivity and high sensitivity, a new multi-parameter simultaneous fluorescence imaging platform (MPSFL-Platform) based on two fluorescence materials was constructed to evaluate the efficacy of new drug for ischemic stroke. Through simultaneous fluorescence observing three key indicators of ischemic stroke, malondialdehyde (MDA), formaldehyde (FA), and monoamine oxidase A (MAO-A), the efficacy evaluations of three drugs for ischemic stroke were real-time and in-situ performed. Compared with edaravone and butylphthalide, edaravone dexborneol exhibited better therapeutic effect by using MPSFL-Platform. The successful establishment of MPSFL-Platform is serviceable to accelerate the conduction of preclinical trial and the exploration of pathophysiology mechanism for drugs related to ischemic stroke and other brain diseases, which is perspective to promote the efficiency of new drug development.

Edaravone dexborneol ameliorates cognitive impairment by regulating the NF-κB pathway through AHR and promoting microglial polarization towards the M2 phenotype in mice with bilateral carotid artery stenosis (BCAS)

Cerebral small vessel disease (CSVD) is one of the most important causes of stroke and vascular dementia, so exploring effective treatment modalities for CSVD is warranted. This study aimed to explore the anti-inflammatory effects of Edaravone dexborneol (C.EDA) in a CSVD model. Mice with CSVD showed distinct cognitive decline, as assessed by the Morris water maze (MWM). Pathological staining verified leakage across the blood‒brain barrier (BBB), microglial proliferation, neuronal loss and demyelination. Western blot analysis demonstrated that M1 microglia dominated prophase and released proinflammatory molecules; the aryl hydrocarbon receptor (AHR) was found to participate in modulating nuclear factor-kappa B (NF-κB) signalling activation through tumour necrosis factor receptor-associated factor-6 (TRAF6). C.EDA treatment resulted in the polarization of microglia from the M1 to the M2 phenotype. Mice sequentially treated with C.EDA exhibited a significant improvement in cognitive function; expression of the anti-inflammatory cytokines and modulatory proteins AHR and TRAF6 was upregulated, while the levels of pNF-κBp65 and pIΚBα were downregulated. C.EDA promoted microglial activation towards the M2 phenotype by upregulating AHR expression, which prevented TRAF6 ubiquitination, promoted NF-κB RelA/p65 protein degradation and inhibited subsequent NF-κB phosphorylation. Mechanistically, the anti-inflammatory effect of C.EDA alleviated neuronal loss and myelin damage, while at the functional level, C.EDA improved cognitive function and thus showed good application prospects.

CircRIMS promotes cerebral ischemia-reperfusion injury through increasing apoptosis and targeting the miR-96-5p/JAK/STAT1 axis

OBJECTIVE

This study aims to explore the function of circRIMS in cerebral ischemia/reperfusion (CIR) and its regulatory mechanism.

METHOD

The expression of the circRIMS was examined in GEO chip data and validated by qRT-PCR analysis. A middle cerebral artery occlusion/repression (MCAO/R) model was developed using C57BL/6J mice. Starbase and circinteractome were employed to identify the target miRNA and mRNA. The result was confirmed by dual-luciferase reporter assay, and biotinylated RNA-pulldown assay. The cell viability and apoptosis were confirmed through CCK-8 and flow cytometry assay.

RESULTS

This study revealed that circRIMS expression was upregulated in MCAO mice model and OGD/RX-simulated cell model. Knockdown circRIMS demonstrated the functional of circRIMS in increasing cell viability, reducing apoptosis, LDH activity and inflammatory factors secretion in OGD/RX-simulated CIR injury in vitro. Additionally, miR-96-5p was identified as a target of circRIMS, while the STAT1 gene is a downstream gene of miR-96-5p, and JAK was also considered to be a downstream gene of the JAK-STAT pathway. Furthermore, inhibition of miR-96-5p or overexpression of STAT1 promoted the progression of CIR injury by elevating apoptosis, reducing cell viability, and increasing the secretion of inflammatory cytokines.

CONCLUSION

CircRIMS contributes to the progression of CIR injury via regulating miR-96-5p/JAK/STAT1 axis.

Inflammatory diseases: Function of LncRNAs in their emergence and the role of mesenchymal stem cell secretome in their treatment

One of the best treatments for inflammatory diseases such as COVID-19, respiratory diseases and brain diseases is treatment with stem cells. Here we investigate the effect of stem cell therapy in the treatment of brain diseases.Preclinical studies have shown promising results, including improved functional recovery and tissue repair in animal models of neurodegenerative diseases, strokes,and traumatic brain injuries. However,ethical implications, safety concerns, and regulatory frameworks necessitate thorough evaluation before transitioning to clinical applications. Additionally, the complex nature of the brain and its intricate cellular environment present unique obstacles that must be overcome to ensure the successful integration and functionality of genetically engineered MSCs. The careful navigation of this path will determine whether the application of genetically engineered MSCs in brain tissue regeneration ultimately lives up to the hype surrounding it.

Low-intensity pulsed ultrasound ameliorates glia-mediated inflammation and neuronal damage in experimental intracerebral hemorrhage conditions

BACKGROUND

Intracerebral hemorrhage (ICH) is a condition associated with high morbidity and mortality, and glia-mediated inflammation is a major contributor to neurological deficits. However, there is currently no proven effective treatment for clinical ICH. Recently, low-intensity pulsed ultrasound (LIPUS), a non-invasive method, has shown potential for neuroprotection in neurodegenerative diseases. This study aimed to investigate the neuroprotective effects and potential mechanisms of LIPUS on glia-mediated inflammation in ICH.

METHODS

This study used 289 mice to investigate the effects of LIPUS on ICH. ICH was induced by injecting bacterial collagenase (type VII-S; 0.0375 U) into the striatum of the mice. LIPUS was applied noninvasively for 3 days, including a 2-h-delayed intervention to mimic clinical usage. The study evaluated neurological function, histology, brain water content, hemoglobin content, MRI, and protein expression of neurotrophic factors, inflammatory molecules, and apoptosis. In vitro studies investigated glia-mediated inflammation by adding thrombin (10 U/mL) or conditioned media to primary and cell line cultures. The PI3K inhibitor LY294002 was used to confirm the effects of PI3K/Akt signaling after LIPUS treatment.

RESULTS

LIPUS treatment improved neurological deficits and reduced tissue loss, edema, and neurodegeneration after ICH. The protective effects of LIPUS resulted from decreased glia-mediated inflammation by inhibiting PI3K/Akt-NF-κB signaling, which reduced cytokine expression and attenuated microglial activation-induced neuronal damage in vitro.

CONCLUSIONS

LIPUS treatment improved neurological outcomes and reduced glia-mediated inflammation by inhibiting PI3K/Akt-NF-κB signaling after ICH. LIPUS may provide a non-invasive potential management strategy for ICH.

Routes and methods of neural stem cells injection in cerebral ischemia

Cerebral ischemia is a serious cerebrovascular disease with the characteristics of high morbidity, disability, and mortality. Currently, stem cell therapy has been extensively applied to a wide range of diseases, including neurological disorders, autoimmune deficits, and other diseases. Transplantation therapy with neural stem cells (NSCs) is a very promising treatment method, which not only has anti-inflammatory, antiapoptotic, promoting angiogenesis, and neurogenesis effects, but also can improve some side effects related to thrombolytic therapy. NSCs treatment could exert protective effects in alleviating cerebral ischemia-induced brain damage and neurological dysfunctions. However, the different injection routes and doses of NSCs determine diverse therapeutic efficacy. This review mainly summarizes the various injection methods and injection effects of NSCs in cerebral ischemia, as well as proposes the existing problems and prospects of NSCs transplantation.

Resolvin D1 reprograms energy metabolism to promote microglia to phagocytize neutrophils after ischemic stroke

Neutrophil aggregation and clearance are important factors affecting neuroinflammatory injury during acute ischemic stroke. Emerging evidence suggests that energy metabolism is essential for microglial functions, especially microglial phagocytosis, which determines the degree of brain injury. Here, we demonstrate that Resolvin D1 (RvD1), a lipid mediator derived from docosahexaenic acid (DHA), promotes the phagocytosis of neutrophils by microglia, thereby reducing neutrophil accumulation in the brain and alleviating neuroinflammation in the ischemic brain. Further studies reveal that RvD1 reprograms energy metabolism from glycolysis to oxidative phosphorylation (OXPHOS), providing sufficient energy for microglial phagocytosis. Moreover, RvD1 enhances microglial glutamine uptake and stimulates glutaminolysis to support OXPHOS to boost ATP production depending on adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) activation. Overall, our results reveal that RvD1 reprograms energy metabolism to promote the microglial phagocytosis of neutrophils after ischemic stroke. These findings may guide perspectives for stroke therapy from modulating microglial immunometabolism.

Effects of the Co-Overexpression of the BCL and BDNF Genes on the Gamma-Aminobutyric Acid-Ergic Differentiation of Wharton's-Jelly-Derived Mesenchymal Stem Cells

One of the problems with using MSCs (mesenchymal stem cells) to treat different neurodegenerative diseases of the central nervous system is their low ability to spontaneously differentiate into functional neurons. The aim of this study was to investigate how the co-overexpression of the BCL and BDNF genes affects the ability of genetically modified MSCs to differentiate into GABA-ergic neurons. A co-overexpression of two genes was performed, one of which, BCL, was supposed to increase the resistance of the cells to the toxic agents in the brain environment. The second one, BDNF, was supposed to direct the cells onto the neuronal differentiation pathway. As a result, the co-overexpression of both BCL2 + BDNF and BCLXL + BDNF caused an increase in the MAP2 gene expression level (a marker of the neuronal pathway) and the SYP gene that is associated with synaptogenesis. In both cases, approximately 18% of the genetically modified and then differentiated cells exhibited the presence of the GAD protein, which is characteristic of GABA-ergic neurons. Despite the presence of GAD, after both modifications, only the BCL2 and BDNF co-overexpression correlated with the ability of the modified cells to release gamma-aminobutyric acid (GABA) after depolarization. Our study identified a novel model of genetically engineered MSCs that can be used as a tool to deliver the antiapoptotic proteins (BCL) and neurotrophic factor (BDNF) directly into the brain microenvironment. Additionally, in the investigated model, the genetically modified MSCs could easily differentiate into functional GABA-ergic neurons and, moreover, due to the secreted BCL and BDNF, promote endogenous neuronal growth and encourage synaptic connections between neurons.

Endothelial cell CD36 mediates stroke-induced brain injury via BBB dysfunction and monocyte infiltration in normal and obese conditions

CD36 expressed in multiple cell types regulates inflammation, vascular function, and innate immunity. Specifically, CD36 in microvascular endothelial cells (ECs) signals to elicit inflammation and causes EC death. This study investigated roles for EC-CD36 on acute stroke pathology in normal and obese conditions. Obesity induced by a high-fat diet (HD) selectively increased CD36 expression in ECs, not in monocytes/macrophages, in the post-ischemic brain. Mice deficient CD36 in ECs (ECCD36-/-) showed reduced injury size and vascular permeability in normal conditions. While control mice fed a HD developed obesity and aggravated stroke injury, ECCD36-/- mice were resistant to develop an obesity phenotype. Subjecting ECCD36-/- mice to stroke resulted in reduced injury size and BBB disruption. Moreover, the mice had reduced MCP-1 and CCR2 gene expression, resulting in reduced monocyte trafficking with improved survival and acute motor function. Reduced MCP-1 and CCR2 expression was still evident in ECCD36-/- mice subjected to severe stroke, suggesting that monocyte trafficking is an infarct-independent metabolic effect associated with specific EC-CD36 deletion. Our findings demonstrate the importance of EC-CD36 in developing vascular comorbidities and suggest that targeting EC-CD36 is a potential preventative strategy to normalize vascular risk factors, leading to improved acute stroke outcomes.

Combination treatment of Danggui Buxue Decoction and endothelial progenitor cells can enhance angiogenesis in rats with focal cerebral ischemia and hyperlipidemia

ETHNOPHARMACOLOGICAL RELEVANCE

Danggui Buxue Decoction (DBD) is a classic prescription of traditional Chinese medicine that is mainly used for treating clinical anemia for more than 800 years. This prescription has been utilized for nourishing "Qi" and enriching "Blood" for women suffering from menopausal symptoms. Meanwhile, DBD has the role of improving angiogenesis and promoting the neuroprotective functions. Bone marrow-derived endothelial progenitor cells (EPCs) was suboptimal to treat the focal cerebral ischemia (FCI). Thus, it's may be a novel strategy of DBD combined with EPCs transplantation for the FCI.

AIM OF THE STUDY

To investigate the mechanistic effects of DBD in combination with EPCs transplantation to improve behavioral function of the FCI and hyperlipidemia.

MATERIALS AND METHODS

We used rats with hyperlipidemia to develop a FCI model using photo-thrombosis, and treated the DBD in combination with EPCs transplantation. We adopted the Modified Neurological Severity Score to evaluate the neurological deficit, undertook the 2,3,5-triphenyltetrazolium chloride staining to calculate the total infarct volume. We carried out the RT-qPCR, Immunohistochemical analyses, TUNEL, ELISA, and Western blotting to measure the gene and protein levels which related to anti-apoptosis mechanisms and angiogenesis.

RESULTS

Administration of DBD in combination with EPCs transplantation was found to improve behavioral function, reducing the infarct volume and decrease the level of total-cholesterole (TC) and low-density lipoprotein-cholesterol (LDL-C). Treatment of DBD plus EPCs increased the mRNA and protein expression of vascular endothelial growth factor A, fibroblastic growth factor-2, and angiopoietin-1 and decreased the apoptosis of endothelial cells by activating the phosphoinositide 3-kinase/protein kinase B/Bcl-xL/Bcl-2 associated death promoter (PI3K/Akt/BAD) pathway and promoting activation of the extracellular signal-regulated kinase (ERK) pathway, which induced angiogenesis directly.

CONCLUSIONS

Our findings provided that DBD administration combined with EPCs transplantation promoted reconstruction of nervous function. This was achieved by enhancing expression of the growth factors related to anti-apoptosis mechanisms and angiogenesis thanks to regulation of the PI3K/Akt/BAD and ERK signaling pathways, and might be relate to the lowering of TC and LDL-C levels.

Plasma β2-microglobulin and cerebrospinal fluid biomarkers of Alzheimer's disease pathology in cognitively intact older adults: the CABLE study

BACKGROUND

Previous studies have suggested a correlation between elevated levels of β₂-microglobulin (B2M) and cognitive impairment. However, the existing evidence is insufficient to establish a conclusive relationship. This study aims to analyze the link of plasma B2M to cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers and cognition.

METHODS

To track the dynamics of plasma B2M in preclinical AD, 846 cognitively healthy individuals in the Chinese Alzheimer's Biomarker and LifestylE (CABLE) cohort were divided into four groups (suspected non-AD pathology [SNAP], 2, 1, 0) according to the NIA-AA criteria. Multiple linear regression models were employed to examine the plasma B2M's relationship with cognitive and CSF AD biomarkers. Causal mediation analysis was conducted through 10,000 bootstrapped iterations to explore the mediating effect of AD pathology on cognition.

RESULTS

We found that the levels of plasma B2M were increased in stages 1 (P = 0.0007) and 2 (P < 0.0001), in contrast to stage 0. In total participants, higher levels of B2M were associated with worse cognitive performance (P = 0.006 for MMSE; P = 0.012 for MoCA). Moreover, a higher level of B2M was associated with decreases in Aβ_1-42 (P < 0.001) and Aβ_1-42/Aβ_1-40 (P = 0.015) as well as increases in T-tau/Aβ_1-42 (P < 0.001) and P-tau/Aβ_1-42 (P < 0.001). The subgroup analysis found B2M correlated with Aβ_1-42 in non-APOE ε4 individuals (P < 0.001) but not in APOE ε4 carriers. Additionally, the link between B2M and cognition was partially mediated by Aβ pathology (percentage: 8.6 to 19.3%), whereas tau pathology did not mediate this effect.

CONCLUSIONS

This study demonstrated the association of plasma B2M with CSF AD biomarkers as well as a possible important role of Aβ pathology in the association between B2M and cognitive impairment, particularly in cognitively normal individuals. The results indicated that B2M could be a potential biomarker for preclinical AD and might have varied functions throughout various stages of preclinical AD progression.

Endothelial progenitor cell transplantation attenuates synaptic loss associated with enhancing complement receptor 3-dependent microglial/macrophage phagocytosis in ischemic mice

Endothelial progenitor cell (EPC) transplantation has therapeutic effects in cerebral ischemia. However, how EPCs modulate microglial activity remains unclear. In the study, we explored whether EPCs modulated microglial/macrophage activity and facilitated injured brain repair. Adult male mice (n = 184) underwent transient middle cerebral artery occlusion, and EPCs were transplanted into the brain immediately after ischemia. Microglial/macrophage activity and complement receptor 3 (CR3) expression were evaluated in ischemic brains and cultured microglia. CR3 agonist leukadherin-1 was administrated into mice immediately after ischemia to imitate the effects of EPCs. Synaptophysin and postsynaptic density protein 95 (PSD-95) expressions were detected in EPC- and leukadherin-1 treated mice. We found that EPC transplantation increased the number of M2 microglia/macrophage-phagocytizing apoptotic cells and CR3 expression in ischemic brains at 3 days after ischemia (p < 0.05). EPC-conditional medium or cultured EPCs increased microglial migration and phagocytosis and upregulated CR3 expression in cultured microglia under oxygen-glucose deprivation condition (p < 0.05). Leukadherin-1 reduced brain atrophy volume and neurological deficits at 14 days after ischemia (p < 0.05). Both EPC transplantation and leukadherin-1 increased synaptophysin and PSD-95 expression at 14 days after ischemia (p < 0.05). EPC transplantation promoted CR3-mediated microglial/macrophage phagocytosis and subsequently attenuated synaptic loss. Our study provided a novel therapeutic mechanism for EPCs.

β2-Microglobulin exacerbates neuroinflammation, brain damage, and cognitive impairment after stroke in rats

β2-Microglobulin (β2M), a component of the major histocompatibility complex class I molecule, is associated with aging-related cognitive impairment and Alzheimer's disease. Although upregulation of β2M is considered to be highly related to ischemic stroke, the specific role and underlying mechanistic action of β2M are poorly understood. In this study, we established a rat model of focal cerebral ischemia by occlusion of the middle cerebral artery. We found that β2M levels in the cerebral spinal fluid, serum, and brain tissue were significantly increased in the acute period but gradually decreased during the recovery period. RNA interference was used to inhibit β2M expression in the acute period of cerebral stroke. Tissue staining with 2,3,5-triphenyltetrazolium chloride and evaluation of cognitive function using the Morris water maze test demonstrated that decreased β2M expression in the ischemic penumbra reduced infarct volume and alleviated cognitive deficits, respectively. Notably, glial cell, caspase-1 (p20), and Nod-like receptor pyrin domain containing 3 (NLRP3) inflammasome activation as well as production of the inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α were also effectively inhibited by β2M silencing. These findings suggest that β2M participates in brain injury and cognitive impairment in a rat model of ischemic stroke through activation of neuroinflammation associated with the NLRP3 inflammasome.

Role of Mesenchymal Stem/Stromal Cells in Modulating Ischemia/Reperfusion Injury: Current State of the Art and Future Perspectives

Ischemia/reperfusion injury (IRI) is a multistep damage that occurs in several tissues when a blood flow interruption is inevitable, such as during organ surgery or transplantation. It is responsible for cell death and tissue dysfunction, thus leading, in the case of transplantation, to organ rejection. IRI takes place during reperfusion, i.e., when blood flow is restored, by activating inflammation and reactive oxygen species (ROS) production, causing mitochondrial damage and apoptosis of parenchymal cells. Unfortunately, none of the therapies currently in use are definitive, prompting the need for new therapeutic approaches. Scientific evidence has proven that mesenchymal stem/stromal cells (MSCs) can reduce inflammation and ROS, prompting this cellular therapy to also be investigated for treatment of IRI. Moreover, it has been shown that MSC therapeutic effects were mediated in part by their secretome, which appears to be involved in immune regulation and tissue repair. For these reasons, mediated MSC paracrine function might be key for injury amelioration upon IRI damage. In this review, we highlight the scientific literature on the potential beneficial use of MSCs and their products for improving IRI outcomes in different tissues/organs, focusing in particular on the paracrine effects mediated by MSCs, and on the molecular mechanisms behind these effects.

CircFOXP1 alleviates brain injury after acute ischemic stroke by regulating STAT3/apoptotic signaling

According to previous studies, circular RNAs (circRNAs) are involved in multiple pathological processes of acute ischemic stroke (AIS). However, the relationship between circFOXP1 and IS has not yet been reported. Here, we found that circFOXP1 expression was significantly decreased in the peripheral blood of AIS patients compared to controls and was associated with the severity and prognosis of AIS. Functionally, knockdown and overexpression of circFOXP1 promoted and inhibited apoptotic signaling, respectively, following oxygen-glucose deprivation/reperfusion (OGD/R) treatment in vitro. Adeno-associated virus (AAV)-mediated circFOXP1 overexpression attenuated neurological deficits and improved functional recovery after transient middle cerebral artery occlusion (tMCAO) treatment in vivo. Mechanistically, decreased QKI expression inhibited circFOXP1 biogenesis under hypoxic conditions. Decreased circFOXP1 expression accelerated signal transducer and activator of transcription 3 (STAT3) protein degradation by binding to and increasing STAT3 protein ubiquitination, ultimately aggravating brain injury after cerebral ischemia by activating apoptotic signaling. In summary, our study is the first to reveal that circFOXP1 alleviates brain injury after cerebral ischemia by regulating STAT3/apoptotic signaling, which provides a potentially novel therapeutic target for AIS.

Kir4.1 channel activation in NG2 glia contributes to remyelination in ischemic stroke

BACKGROUND

Stroke is one of the most common neurological diseases in the world and is clinically manifested by transient or permanent brain dysfunction. It has a high mortality and disability rate, which severely affects people's health and diminishes the quality of life. However, there is no efficient treatment that can be considered curative and there are other less well-known theories of pathogenesis. Therefore, it is imperative to gain a full understanding of the pathophysiology of ischemia and to seek new therapeutic strategies.

METHODS

We first examined Kir4.1 channel and myelin based protein (MBP) expression in brain tissues from acute ischemic patients by Western blotting. We then established a transient ischemic mouse model (tMCAO) to conduct molecular, cell biological, transmission electron microscopy and pharmacokinetic studies, as well as in Kir4.1 cKO mice. Finally, neuroimaging and behavioral analyses were used to examine whether activation of Kir4.1 channel by luteolin could contribute to neuronal functional recovery in ischemic stroke.

FINDINGS

In acute ischemic stroke patients, we first demonstrated that Kir4.1 ion channels were greatly impaired and a severe demyelination of axons occurred in ischemic infarction area of cerebral cortex in these patients. Further evidence showed that the deficits of Kir4.1 channels in NG2 glia led to the myelin loss of axons in a transient ischemic mouse model (tMCAO). Treating ischemic mice with a natural botanical extract, luteolin augmented Kir4.1 channel currents in NG2 glia and consequently promoted remyelination of axons, alleviated the infarction area and ultimately improved motor function in a series of behavioral tests.

INTERPRETATION

Targeting Kir4.1 ion channels expressed in NG2 glial cells by luteolin treatment highlights an effective therapeutic strategy for a prompt brain functional recovery in ischemic stroke.

FUNDING

This work was supported by grants from the Ministry of Science and Technology China Brain Initiative (2022ZD0204702, to X.T.), the National Natural Science Foundation of China (82271466, 82171279, 31970904 and 31571063), the Program for Professor of Special Appointment (Eastern Scholar for Dr. X.T.) at Shanghai Institutions for Higher Learning (1510000084), Shanghai Pujiang Talent Award (15PJ1404600), Shanghai Municipal Science and Technology Major Project (2018SHZDZX05) and Shanghai Science and Technology Project (17411954000).

Redefining the Koizumi model of mouse cerebral ischemia: A comparative longitudinal study of cerebral and retinal ischemia in the Koizumi and Longa middle cerebral artery occlusion models

Cerebral and retinal ischemia share similar pathogenesis and epidemiology, each carrying both acute and prolonged risk of the other and often co-occurring. The most used preclinical stroke models, the Koizumi and Longa middle cerebral artery occlusion (MCAO) methods, have reported retinal damage with great variability, leaving the disruption of retinal blood supply via MCAO poorly investigated, even providing conflicting assumptions on the origin of the ophthalmic artery in rodents. The aim of our study was to use longitudinal in vivo magnetic resonance assessment of cerebral and retinal vascular perfusion after the ischemic injury to clarify whether and how the Koizumi and Longa methods induce retinal ischemia and how they differ in terms of cerebral and retinal lesion evolution. We provided anatomical evidence of the origin of the ophthalmic artery in mice from the pterygopalatine artery. Following the Koizumi surgery, retinal responses to ischemia overlapped with those in the brain, resulting in permanent damage. In contrast, the Longa method produced only extensive cerebral lesions, with greater tissue loss than in the Koizumi method. Additionally, our data suggests the Koizumi method should be redefined as a model of ischemia with chronic hypoperfusion rather than of ischemia and reperfusion.

Traumatic brain injury recapitulates developmental changes of axons

During development, half of brain white matter axons are maintained for growth, while the remainder undergo developmental axon degeneration. After traumatic brain injury (TBI), injured axons also appear to follow pathways leading to either degeneration or repair. These observations raise the intriguing, but unexamined possibility that TBI recapitulates developmental axonal programs. Here, we examined axonal changes in the developing brain in young rats and after TBI in adult rat. Multiple shared changes in axonal microtubule (MT) through tubulin post-translational modifications and MT associated proteins (MAPs), tau and MAP6, were found in both development and TBI. Specifically, degenerating axons in both development and TBI underwent phosphorylation of tau and excessive tubulin tyrosination, suggesting MT instability and depolyermization. Conversely, nearby axons without degenerating morphologies, had increased MAP6 expression and maintenance of tubulin acetylation, suggesting enhanced MT stabilization, thereby supporting survival or repair. Quantitative proteomics revealed similar signaling pathways of axon degeneration and growth/repair, including protein clusters and networks. This comparison approach demonstrates how focused evaluation of developmental processes may provide insight into pathways initiated by TBI. In particular, the data suggest that TBI may reawaken dormant axonal programs that direct axons towards either degeneration or growth/repair, supporting further study in this area.

Regulatory mechanisms of tetramethylpyrazine on central nervous system diseases: A review

Central nervous system (CNS) diseases can lead to motor, sensory, speech, cognitive dysfunction, and sometimes even death. These diseases are recognized to cause a substantial socio-economic impact on a global scale. Tetramethylpyrazine (TMP) is one of the main active ingredients extracted from the Chinese herbal medicine Ligusticum striatum DC. (Chuan Xiong). Many in vivo and in vitro studies have demonstrated that TMP has a certain role in the treatment of CNS diseases through inhibiting calcium ion overload and glutamate excitotoxicity, anti-oxidative/nitrification stress, mitigating inflammatory response, anti-apoptosis, protecting the integrity of the blood-brain barrier (BBB) and facilitating synaptic plasticity. In this review, we summarize the roles and mechanisms of action of TMP on ischemic cerebrovascular disease, spinal cord injury, Parkinson’s disease, Alzheimer’s disease, cognitive impairments, migraine, and depression. Our review will provide new insights into the clinical applications of TMP and the development of novel therapeutics.

Assessing the Global Impact on the Mouse Kidney After Traumatic Brain Injury: A Transcriptomic Study

Purpose

In this study, we use animal models combined with bioinformatics strategies to investigate the potential changes in overall renal transcriptional expression after traumatic brain injury.

Methods

Microarray analysis was performed after kidney acquisition using unilateral controlled cortical impact as the primary mouse TBI model. Multi-oriented gene set enrichment analysis was performed for differentially expressed genes.

Results

The results showed that TBI affected the gene set associated with mitochondria function in kidney cells, and a negative enrichment of gene sets associated with immune cell migration and epidermal development was also observed. Analysis of the disease phenotype gene set revealed that differential expression of mitochondria-related genes was associated with lactate metabolism. Alternatively, activation and adhesion of immune cells associated with the complement system may promote autoinflammation in kidney tissue. The simulated immune cell infiltration analysis showed an increase in the proportion of activated memory CD4 T cells and a decrease in the proportion of resting memory CD4 T cells, suggesting that activated memory CD4 T cell infiltration may be involved in the inflammation of renal tissue and cause damage to renal cells, such as principal cells, mesangial cells and loops of Henle cells.

Conclusion

This study is the first to reveal the effects of brain trauma on the kidney. TBI may affect the expression of mitochondria function-related gene sets in renal cells by increasing lactate. It may also affect renal mesangial cells by inducing increased infiltration of immune cells through mechanisms related to complement system activation or autoimmune antibodies.

LncRNA Tug1 Contributes Post-stroke NLRP3 Inflammasome-Dependent Pyroptosis via miR-145a-5p/Tlr4 Axis

Pyroptosis, a type of programmed cell death illuminated by inflammasomes and active caspases, is implicated in post-stroke inflammation. Our previous study showed that lncRNA taurine upregulated gene 1 (Tug1) sponging miR-145a-5p modulated microglial activation after oxygen-glucose deprivation (OGD). However, the role and mechanism of Tug1 on post-stroke pyroptosis is not fully clear. Photo-thrombosis stroke mice and OGD-treated BV-2 microglia were established respectively. Tug1 knockdown or overexpression was achieved by intraventricular infusion of AAV-shTug1 in vivo, or transfection of siTug1 and pcDNA3.1-Tug1 in vitro. Neurological function and infarction volume were evaluated. Meanwhile, pyroptosis-associated proteins (IL-1β, IL-18, NLRP3, ASC, cleaved-caspase-1, and GSDMD-N), TLR4, and p-p65/p65 as well as Tug1 and miR-145a-5p were detected 24 h after photo-thrombosis or 4 h after OGD by qRT-PCR, western blot, and ELISA. The correlation between Tug1/miR-145a-5p/Tlr4 axis and pyroptosis was explored by dual-luciferase reporter assay and functional gain-and-loss experiments. Photo-thrombosis or OGD caused neural injury and upregulated pyroptosis-associated proteins, Tug1, TLR4, and p-p65 as well as downregulated miR-145a-5p, which was prevented by Tug1 knockdown in vivo and in vitro. Tlr4 gene, putatively binding with miR-145a-5p by bioinformatics analysis, was found to be a direct target of miR-145a-5p with negative interactions. Furthermore, miR-145a-5p inhibitor abolished the inhibitive effects of siTug1 on TLR4 and p-p65 as well as pyroptosis-associated proteins, whereas miR-145a-5p mimics abrogated the enhanced effects of pcDNA3.1-Tug1 on that, suggesting an involvement of Tug1/miR-145a-5p/Tlr4 axis on pyroptosis. Tug1 contributes NLRP3 inflammasome-dependent pyroptosis through miR-145a-5p/Tlr4 axis post-stroke, providing a promising therapeutic strategy against inflammatory injury.

Blocking C3d+/GFAP+ A1 Astrocyte Conversion with Semaglutide Attenuates Blood-Brain Barrier Disruption in Mice after Ischemic Stroke

Astrocytes play an essential role in the modulation of blood-brain barrier function. Neurological diseases induce the transformation of astrocytes into a neurotoxic A1 phenotype, exacerbating brain injury. However, the effect of A1 astrocytes on the BBB dysfunction after stroke is unknown. Adult male ICR mice (n=97) were subjected to 90-minute transient middle cerebral artery occlusion (tMCAO). Immunohistochemical staining of A1 (C3d) and A2 (S100A10) was performed to characterize phenotypic changes in astrocytes over time after tMCAO. The glucagon-like peptide-1 receptor agonist semaglutide was intraperitoneally injected into mice to inhibit A1 astrocytes. Infarct volume, atrophy volume, neurobehavioral outcomes, and BBB permeability were evaluated. RNA-seq was adopted to explore the potential targets and signaling pathways of A1 astrocyte-induced BBB dysfunction. Astrocytic C3d expression was increased, while expression of S100A10 was decreased in the first two weeks after tMCAO, reflecting a shift in the astrocytic phenotype. Semaglutide treatment reduced the expression of CD16/32 in microglia and C3d in astrocytes after ischemic stroke (p<0.05). Ischemia-induced brain infarct volume, atrophy volume and neuroinflammation were reduced in the semaglutide-treated mice, and neurobehavioral outcomes were improved compared to control mice (p<0.05). We further demonstrated that semaglutide treatment reduced the gap formation of tight junction proteins ZO-1, claudin-5 and occludin, as well as IgG leakage three days following tMCAO (p<0.05). In vitro experiments revealed that A1 astrocyte-conditioned medium disrupted BBB integrity. RNA-seq showed that A1 astrocytes were enriched in inflammatory factors and chemokines and significantly modulated the TNF and chemokine signaling pathways, which are closely related to barrier damage. We concluded that astrocytes undergo a phenotypic shift over time after ischemic stroke. C3d⁺/GFAP⁺ astrocytes aggravate BBB disruption, suggesting that inhibiting C3d⁺/GFAP⁺ astrocyte formation represents a novel strategy for the treatment of ischemic stroke.

Targeted delivery of fat extract by platelet membrane-cloaked nanocarriers for the treatment of ischemic stroke

BACKGROUND

Our previous studies suggest that human fat extract (FE) contains a variety of angiogenic factors and may provide an alternative treatment option for stroke. However, the therapeutic effect is largely limited due to its short half-life, and inaccurate targeting.

RESULTS

Herein, we leverage the targeting abilities of platelets (PLTs) to the lesion area of stroke and Arg-Gly-Asp (RGD) peptides to the angiogenic blood vessels to develop a biomimetic nanocarrier that capable of delivering FE precisely to treat stroke. The biomimetic nanocarriers are comprised of FE-encapsulated PLGA (poly(lactic-co-glycolic acid)) core enclosed by RGD peptides decorated plasma membrane of PLTs, namely RGD-PLT@PLGA-FE. We found that RGD-PLT@PLGA-FE not only targeted damaged and inflamed blood vessels but also achieved rapid accumulation in the lesion area of ischemic brain. In addition, RGD-PLT@PLGA-FE kept a sustained release behavior of FE at the lesion site, effectively increased its half-life and promoted angiogenesis and neurogenesis with delivering neurotrophic factors including BDNF, GDNF and bFGF to the brain, that ultimately resulted in blood flow increase and neurobehavioral recovery.

CONCLUSIONS

In conclusion, our study provides a new strategy to design a biomimetic system for FE delivery and it is a promising modality for stroke therapy.

CircUSP36 attenuates ischemic stroke injury through the miR-139-3p/SMAD3/Bcl2 signal axis

Circular RNAs (circRNAs) play important roles in a variety of physiological and pathological processes. Researches demonstrated that circRNAs provided novel strategies for the prevention and treatment of IS. However, the biological function of hsa_circ_0045932 (circUSP36) has not been revealed yet. Here, we explored the effect of circUSP36 on IS and its mechanism. In this study, we found that circUSP36 expression was significantly decreased in the peripheral blood of IS patients and was negatively correlated with the severity, infarct volume and poor prognosis of IS. Functionally, circUSP36 silencing inhibited cellular activity and proliferation and promoted apoptosis after oxygen-glucose deprivation/reperfusion (OGD/R) treatment, while circUSP36 overexpression reversed these cellular phenotypes in vitro. Adeno-associated virus (AAV)-mediated overexpression of circUSP36 attenuates brain injury and neurological deficit and promotes motor function recovery of transient middle cerebral artery occlusion (tMCAO) mice. Subsequently, the RNA antisense purification (RAP) and luciferase reporter assay confirmed that circUSP36 acts as a sponge to adsorb miR-139-3p, and miR-139-3p could bind and inhibit SMAD3 expression. Further rescue experiments showed that both miR-139-3p overexpression and SMAD3 silencing could abolish the antiapoptotic effect of circUSP36. In summary, we reveal for the first time that circUSP36 attenuates ischemic stroke injury through the miR-139-3p/SMAD3/Bcl2 signal axis, which make circUSP36 a potential therapeutic target for IS.

Role of uroguanylin's signaling pathway in the development of ischemic stroke

Stroke is one of the leading causes of mortality and disability worldwide. By affecting bradykinin function, activation of guanylate cyclase (GC)‐A has been shown to have a neuroprotective effect after ischaemic stroke, whereas the same has not been confirmed for GC‐B; therefore, we aimed to determine the possible role of GC‐C and its agonist, uroguanylin (UGN), in the development of stroke. In this study, middle cerebral artery occlusion (MCAO) was performed on wild‐type (WT), GC‐C KO and UGN KO mice. MR images were acquired before and 24 h after MCAO. On brain slices 48 h after MCAO, the Ca²⁺ response to UGN stimulation was recorded. Our results showed that the absence of GC‐C in GC‐C KO mice resulted in the development of smaller ischaemic lesions compared with WT littermates, which is an opposite effect compared with the effects of GC‐A agonists on brain lesions. WT and UGN KO animals showed a stronger Ca²⁺ response upon UGN stimulation in astrocytes of the peri‐ischaemic cerebral cortex compared with the same cortical region of the unaffected contralateral hemisphere. This stronger activation was not observed in GC‐C KO animals, which may be the reason for smaller lesion development in GC‐C KO mice. The reason why GC‐C might affect Ca²⁺ signalling in peri‐ischaemic astrocytes is that GC‐C is expressed in these cells after MCAO, whereas under normoxic conditions, it is expressed mainly in cortical neurons. Stronger activation of the Ca²⁺‐dependent signalling pathway could lead to the stronger activation of the Na⁺/H⁺ exchanger, tissue acidification and neuronal death.

circDlgap4 Alleviates Cerebral Ischaemic Injury by Binding to AUF1 to Suppress Oxidative Stress and Neuroinflammation

Ischaemic stroke is one of the most common causes of mortality and morbidity.circDlgap4 has been implicated in ischemia/reperfusion injury through an unknown mechanism. Here, we studied the function of circDlgap4/AUF1 in ischaemic stroke and its underlying molecular mechanism. N2a cells and primary mouse cortical neurons were subjected to OGD to mimic neuronal injury during ischemia. BV-2 cells were treated with LPS to mimic neuroinflammation. The MTT assay was used to assess cell viability, while flow cytometry was used to measure cell apoptosis. qRT-PCR, western blotting, immunohistochemistry, and immunostaining were employed to determine the levels of circDlgap4, AUF1, NRF2/HO-1, proinflammatory cytokines, NF-κB pathway-related proteins, and IBA-1. RIP and RNA pulldown assays were employed to validate the interactions of circDlgap4/AUF1, AUF1/NRF2, and AUF1/cytokine mRNAs. mRNA degradation was used to determine the effects on mRNA stability. The tMCAO model was used as an in vivo model of ischaemic stroke. TCC staining and neurological scoring were performed to evaluate ischaemic injury. circDlgap4 was decreased following OGD and during tMCAO. circDlgap4 overexpression inhibited OGD-induced cell death and oxidative stress and LPS-induced increases in proinflammatory cytokines by increasing NRF2/HO-1. Knockdown of AUF1 blocked the effects of circDlgap4 overexpression. Mechanistically, RIP, RNA pulldown, and mRNA degradation assay results showed circDlgap4/AUF1/NRF2 mRNA formed a complex to stabilize NRF2 mRNA. Furthermore, AUF1 directly interacted with TNF-α, IL-1β, and COX-2 mRNAs, and circDlgap4/AUF1 binding promoted the degradation of these mRNAs. Finally, circDlgap4 ameliorated ischaemic injury in vivo. circDlgap4 alleviates ischaemic stroke injury by suppressing oxidative stress and neuroinflammation by binding to AUF1.

Combination of Stem Cells with Chinese Herbs for Secondary Depression in Neurodegenerative Diseases Based on Traditional Chinese Medicine Theories

Depression is a common secondary symptom in neurodegenerative diseases (NDs) caused by the loss of neurons and glial cells. Recent research focuses on stem cell therapy to replace dead nerve cells, but the low efficiency of stem cell differentiation and short survival time are obstacles limiting the therapy's effectiveness. Clinically, patients with different diseases cannot obtain the same effect by using the same cell therapy. However, traditional Chinese medicine (TCM) often uses syndrome differentiation to determine the treatment plan for NDs. Based on TCM syndrome differentiation and treatment, this article summarizes the advantages of Chinese herbal medicine combined with stem cell therapy, mainly for the effects of various herbs on diseases and stem cells, including prolonging the survival time of stem cells, resisting inflammation, and antidepressant-like effects. In particular, it analyzes the unique pathways of the influence of drugs and acupuncture on different therapies, seeking to clarify the scientific TCM system. This review mainly elaborates on the treatment of secondary depression in TCM and the advantages of a herbal combined stem cell therapy in various methods. We believe it can provide a new clinical concept for secondary depression to obtain good clinical effects and reduce the risks borne by patients.

Gut Microbial Dysbiosis Associated with Type 2 Diabetes Aggravates Acute Ischemic Stroke

Type 2 diabetes (T2D) is an independent risk factor for acute ischemic stroke (AIS), but the underlying mechanisms remain elusive. Because the gut microbiota plays a causal role in both T2D and AIS, we wondered whether gut dysbiosis in T2D aggravates stroke progression. We recruited 35 T2D, 90 AIS, 60 AIS with T2D (AIS_T2D) patients, and 55 healthy controls and found that AIS and T2D had an additive effect on AIS_T2D patient gut dysbiosis by exhibiting the largest difference from the heathy controls. In addition, we found that the degree of gut dysbiosis associated with T2D was positively correlated with the National Institutes of Health Stroke Scale (NIHSS), modified Rankin score (mRS), and Essen stroke risk score in patients with AIS, including AIS and AIS_T2D patients. Compared with mice colonized with gut microbiota from healthy controls poststroke modeling, germfree (GF) mice colonized with gut microbiota from T2D patients showed exacerbated cerebral injury and impaired gut barrier function. Specifically, exacerbated brain injury and gut barrier dysfunction in T2D-treated GF mice were significantly associated with a reduction in short-chain fatty acid (SCFA)-producing bacteria. Our study showed that T2D and AIS have an additive effect on AIS_T2D patient gut microbiota dysbiosis. T2D-associated gut microbiota dysbiosis is associated with stroke severity in AIS patients and aggravates stroke progression in mice.

IMPORTANCE We demonstrated an additive effect of type 2 diabetes (T2D) and acute ischemic stroke (AIS) on AIS with T2D (AIS_T2D) patient gut microbiota dysbiosis, and gut dysbiosis associated with T2D was positively correlated with stroke severity in AIS patients. Through animal experiments, we found that cerebral injury was exacerbated by fecal microbiota transplantation from T2D patients compared with that from healthy controls, which was associated with a reduction in short-chain fatty acid (SCFA)-producing bacteria. This study provided a novel view that links T2D and AIS through gut microbial dysbiosis.