Rat Model Of Stroke Research Articles

Abstract TP337: Blocking insulin-like growth factor 1 receptor in the gut abrogates IGF-1 mediated long-term neuroprotection in middle-aged female rats

Background and Purpose: Our previous studies in a rat model of ischemic stroke identified that intraperitoneal (IP), but not intracerebroventricular (ICV) administration of IGF-1 reduced stroke-induced gut leakiness and peripheral inflammation in the acute phase and attenuated stroke-induced impairment in acyclic middle-aged female rats. These data suggest that the gut may be implicated in IGF-1-mediated effects on stroke-induced cognitive impairment. To directly assess whether the effect of IGF-1 on behavioral improvement is mediated by the gut, study utilized a novel tet-inducible rAAV construct to block IGF1R specifically in the gut. Methods: Female Sprague Dawley rats (9-11 mo) were intragastrically gavaged with either recombinant rAAV construct containing IGFR-shRNA (IGFR-sh) downstream of the IESC promoter Lgr5 in a Tet-inducible system or rAAV-empty vector (Scr-sh) 4 weeks prior to experimental ischemia. Animals were subjected to endothelin-1 induced MCAo. Doxycycline was administered 4h later and IGF-1 was given ip at 4 and 24 h post-stroke. Sensorimotor function as well as peripheral inflammation (in serum samples) was assessed at 5d post-stroke and long-term cognitive impairment was evaluated after 60 days. Results: The mCherry reporter in the rAAV construct was observed in the intestinal crypt, indicating appropriate delivery of the construct. Sensorimotor function evaluated by vibrissae evoked forelimb placement task was significantly impaired in the ipsilateral paw after stroke in IGFR-Sh+IGF-1 compared to Scr-sh+IGF-1(p<0.005). IL-17 levels in serum were significantly elevated in the animals with IGFR-Sh+IGF1 compared to Scr_sh+IGF1 (p<0.004). Cognitive impairment assessed by Barnes maze showed no differences in spatial learning but revealed significant impairment in spatial recall in IGFR-sh+IGF1 group compared to SCR-sh+IGF1 animals (p<0.02). Conclusions: The present findings indicate that the beneficial effects of IGF-1 on long-term stroke recovery may be partially mediated by its effects on the gut and implicate the inflammatory cytokine IL-17a as a modifier of stroke-induced cognitive impairment. Supported by RF1NS119872 to FS and SB

Berberine enhances autophagic flux to alleviate ischemic neuronal injury by facilitating N-ethylmaleimide-sensitive factor-mediated fusion of autophagosomes with lysosomes.

Our previous study demonstrated that Berberine (BBR) significantly enhances autophagic flux, alleviating ischemic neuronal injury by restoring autolysosomal function, but how BBR augmented autolysosomal functions remained elusive. N-ethyl-maleimide sensitive factor (NSF) is considered as a major ATPase to reactivate soluble NSF attachment protein receptors (SNAREs), which directly mediate autophagosome-lysosome fusion. However, NSF was dramatically inactivated by ischemia to hamper membrane-membrane fusion, leading to autophagic/lysosomal dysfunction in neurons. This study was to investigate whether BBR-ameliorated autophagic flux was exerted by reinforcing NSF activity, which subsequently boosted autophagosome-lysosome fusion in ischemic neurons. Rat model of ischemic stroke and neuronal ischemia model of HT22 cells were prepared by middle cerebral artery occlusion (MCAO) and oxygen-glucose deprivation (OGD), respectively. BBR was intraperitoneally administrated with 100 mg/Kg/d for 3 days before MCAO and was treated with 90 μM in HT22 neurons for 12 h, respectively. The results illustrated that NSF activity was markedly reinforced to facilitate autophagosome-lysosome fusion in penumbral cells and OGD HT22 neurons by BBR treatment. Consequently, the ischemia-created autophagic/lysosomal dysfunction was greatly restored to alleviate ischemic injury. Thereafter, NSF activity in OGD HT22 neurons was altered by transfection with NSF-overexpressing lentiviruses and siRNA-mediated knockdown, respectively. The data showed that BBR-enhanced autophagic flux and it-induced neuroprotection were greatly counteracted by NSF knockdown. By contrast, NSF overexpression synergistically boosted autophagosome-lysosome fusion and further attenuated neuronal death upon BBR treatment. Therefore, our study indicates that BBR-conferred neuroprotection against ischemic stroke is induced through facilitating autophagosome-lysosome fusion, by which enhancing autophagic flux in ischemic neurons.

Therapeutic effects of traditional Chinese medicine Hua-Feng-Dan in a rat model of ischemic stroke involve renormalization of gut microbiota

Hua-Feng-Dan is a traditional Chinese medicine used to treat ischemic stroke, but little is known about its therapeutic mechanism. This study explored whether and how the mechanism involves readjustment of gut microbiota. Rats were subjected to middle cerebral artery occlusion as a model of ischemic stroke or to sham surgery, then treated or not with Hua-Feng-Dan. The different groups of animals were compared in terms of neurological score, cerebral infarct volume, brain edema, brain and gut histopathology to assess stroke severity. They were also compared in terms of indices of intestinal barrier permeability, inflammation and oxidative stress, brain metabolites as well as composition of the gut microbiota and their metabolites. Hua-Feng-Dan significantly reduced cerebral infarct volume and brain water content and improved neurological score, ischemic brain histopathology, and gut histopathology. It partially reversed stroke-induced intestinal barrier disruption and leakage, inflammation, dyslipidemia and oxidative stress, as well as the stroke-induced increase in pathogenic gut microbiota (e.g., Escherichia-Shigella, Enterococcus, Clostridium_innocuum_group) and decrease in beneficial microbiota (e.g., Lachnospiraceae, unclassified__f__Lachnospiracea and Ruminococcus_torques_group). The treatment altered levels of 39 and 38 metabolites produced during gut microbial and brain tissue metabolism respectively, mainly of amino acids, nucleosides, short-chain fatty acids, and essential fatty acids. Levels of factors related to inflammation and intestinal barrier permeability correlated positively with relative abundance of Escherichia-Shigella and Clostridium_innocuum_group, and negatively with 4-(glutamylamino) butanoate, 2-hydroxy-3-methylbutyric acid, dihomo-α-linolenic acid, dihomolinoleic acid, and 10-nitrolinoleic acid. Conversely, levels of 4-(glutamylamino) butanoate, 2-hydroxy-3-methylbutyric acid, and 10-nitrolinoleic acid correlated positively with relative abundance of unclassified__f__Lachnospiracea. Our results suggest that Hua-Feng-Dan may mitigate ischemic stroke injury by renormalizing gut microbiota and restoring gut barrier function, gut metabolism, thereby helping to alleviate inflammatory, neurological damage, and brain metabolic disorders.

Therapeutic effects of intracerebral transplantation of human modified bone marrow-derived stromal cells (SB623) with voluntary and forced exercise in a rat model of ischemic stroke.

Ischemic stroke results in significant long-term disability and mortality worldwide. Although existing therapies, such as recombinant tissue plasminogen activator and mechanical thrombectomy, have shown promise, their application is limited by stringent conditions. Mesenchymal stem cell (MSC) transplantation, especially using SB623 cells (modified human bone marrow-derived MSCs), has emerged as a promising alternative, promoting neurogenesis and recovery. This study evaluated the effects of voluntary and forced exercise, alone and in combination with SB623 cell transplantation, on neurological and psychological outcomes in a rat model of ischemic stroke. Male Wistar rats that had undergone middle cerebral artery occlusion (MCAO) were divided into six groups: control, voluntary exercise (V-Ex), forced exercise (F-Ex), SB623 transplantation, SB623 + V-Ex, and SB623 + F-Ex. Voluntary exercise was facilitated using running wheels, while forced exercise was conducted on treadmills. Neurological recovery was assessed using the modified neurological severity score (mNSS). Psychological symptoms were evaluated through the open field test (OFT) and forced swim test (FST), and neurogenesis was assessed via BrdU labeling. Both exercise groups exhibited significant changes in body weight post-MCAO. Both exercises enhanced the treatment effect of SB623 transplantation. The forced exercise showed a stronger treatment effect on ischemic stroke than voluntary exercise alone, and the sole voluntary exercise improved depression-like behavior. The SB623 + F-Ex group demonstrated the greatest improvements in motor function, infarct area reduction, and neurogenesis. The SB623 + V-Ex group was most effective in alleviating depression-like behavior. Future research should optimize these exercise protocols and elucidate the underlying mechanisms to develop tailored rehabilitation strategies for stroke patients.

Exosomes derived from highly scalable and regenerative human progenitor cells promote functional improvement in a rat model of ischemic stroke.

Globally, there are 15 million stroke patients each year who have significant neurological deficits. Today, there are no treatments that directly address these deficits. With demographics shifting to an older population, the problem is worsening. Therefore, it is crucial to develop feasible therapeutic treatments for stroke. In this study, we tested exosomes derived from embryonic endothelial progenitor cells (eEPC) to assess their therapeutic efficacy in a rat model of ischemic stroke. Importantly, we have developed purification methods aimed at producing robust and scalable exosomes suitable for manufacturing clinical grade therapeutic exosomes. We characterized exosome cargos including RNA-seq, miRNAs targets, and proteomic mass spectrometry analysis, and we found that eEPC-exosomes were enhanced with angiogenic miRNAs (i.e., miR-126), anti-inflammatory miRNA (i.e., miR-146), and anti-apoptotic miRNAs (i.e., miR-21). The angiogenic activity of diverse eEPC-exosomes sourced from a panel of eEPC production lines was assessed in vitro by live-cell vascular tube formation and scratch wound assays, showing that several eEPC-exosomes promoted the proliferation, tube formation, and migration in endothelial cells. We further applied the exosomes systemically in a rat middle cerebral artery occlusion (MCAO) model of stroke and tested for neurological recovery (mNSS) after injury in ischemic animals. The mNSS scores revealed that recovery of sensorimotor functioning in ischemic MCAO rats increased significantly after intravenous administration of eEPC-exosomes and outpaced recovery obtained through treatment with umbilical cord stem cells. Finally, we investigated the potential mechanism of eEPC-exosomes in mitigating ischemic stroke injury and inflammation by the expression of neuronal, endothelial, and inflammatory markers. Taken together, these data support the finding that eEPCs provide a valuable source of exosomes for developing scalable therapeutic products and therapies for stroke and other ischemic diseases.

Evaluating Cell Death Signaling by Immunofluorescence in a Rat Model of Ischemic Stroke.

Stroke is a leading cause of death and disability worldwide. Most cases of stroke are ischemic and result from the occlusion of the middle cerebral artery (MCA). Current pharmacological approaches for the treatment of ischemic stroke are limited; therefore, novel therapies providing effective neuroprotection against ischemic injury following stroke are urgently needed. In the brain tissue following ischemic stroke, the area of the ischemic penumbra is salvageable but at risk of progressing to irreversible damage. The penumbral area surrounding the infarcted core is a conceptual target for neuroprotection. Since the blood flow is partially maintained in the penumbral area, neuronal and non-neuronal cells in this area transiently survive after stroke, and these cells that are still viable may be rescued by appropriate medical interventions. Understanding the pathophysiology of the penumbra is important in the development of neuroprotective therapies because the cell death pathways activated in the ischemic penumbra may indicate therapeutic targets, such as RUNX1 and cathepsins. These protein targets functioning as mediators of programmed cell death can be further exploited in translational research. With moderate size and similarity to the human brain, the in vivo rat model of MCA occlusion (MCAO) mimics the human ischemic stroke and offers an applicable tool to investigate the penumbral pathology, examine the cell death signaling, and evaluate the effects of potential targets in the context of MCAO. Here, we describe how to induce MCAO in rats and how to perform immunofluorescence staining for the detection of cell death signaling in the rat brain following MCAO.

HESC-derived extracellular vesicles enriched with MFGE-8 and the GSH redox system act as senotherapeutics for neural stem cells in ischemic stroke.

Human embryonic stem cells (hESCs) and their extracellular vesicles (EVs) hold significant potential for tissue repair and regeneration. Neural stem cells (NSCs) in the adult brain often acquire senescent phenotypes after ischemic injuries, releasing neurodegenerative senescence-associated secretory phenotype factors. In this study, we investigated the senotherapeutic effects of hESC-EVs on NSCs and confirmed their neuroprotective effects in neurons via rejuvenation of NSC secretions. Proteomic profiling of hESC-EVs identified MFGE-8 as a critical bridging molecule to NSCs. We also found that the glutathione (GSH) redox system is a key contributor to the therapeutic antioxidant activity of hESC-EVs. Additionally, EVs produced by the hypoxic preconditioning of hESCs (hESC-HypoxEVs) exhibited reinforced GSH redox capacity and further enhanced the senotherapeutic effects on NSCs compared to naïve hESC-EVs. We also demonstrated that administration of hESC-HypoxEVs, precoated with MFGE-8, significantly increased the populations of NSCs and newborn neurons in the subventricular zone of the brain and improved sensorimotor functions in a rat model of ischemic stroke. Our study suggests that combining hESC-HypoxEVs with MFGE-8 may serve as an effective therapeutic modality for reversing senescence and enhancing the neurogenic potential of NSCs to treat neurodegenerative diseases.

Connectome-based prediction of functional impairment in experimental stroke models.

Experimental rat models of stroke and hemorrhage are important tools to investigate cerebrovascular disease pathophysiology mechanisms, yet how significant patterns of functional impairment induced in various models of stroke are related to changes in connectivity at the level of neuronal populations and mesoscopic parcellations of rat brains remain unresolved. To address this gap in knowledge, we employed two middle cerebral artery occlusion models and one intracerebral hemorrhage model with variant extent and location of neuronal dysfunction. Motor and spatial memory function was assessed and the level of hippocampal activation via Fos immunohistochemistry. Contribution of connectivity change to functional impairment was analyzed for connection similarities, graph distances and spatial distances as well as the importance of regions in terms of network architecture based on the neuroVIISAS rat connectome. We found that functional impairment correlated with not only the extent but also the locations of the injury among the models. In addition, via coactivation analysis in dynamic rat brain models, we found that lesioned regions led to stronger coactivations with motor function and spatial learning regions than with other unaffected regions of the connectome. Dynamic modeling with the weighted bilateral connectome detected changes in signal propagation in the remote hippocampus in all 3 stroke types, predicting the extent of hippocampal hypoactivation and impairment in spatial learning and memory function. Our study provides a comprehensive analytical framework in predictive identification of remote regions not directly altered by stroke events and their functional implication.

Therapeutic effects of low-intensity transcranial focused ultrasound stimulation on ischemic stroke in rats: an in vivo evaluation using electrical impedance tomography.

Although previous studies have demonstrated that transcranial focused ultrasound stimulation protects the ischemic brain, clear criteria for the stimulation time window and intensity are lacking. Electrical impedance tomography enables real-time monitoring of changes in cerebral blood perfusion within the ischemic brain, but investigating the feasibility of using this method to assess post-stroke rehabilitation in vivo remains critical. In this study, ischemic stroke was induced in rats through middle cerebral artery occlusion surgery. Transcranial focused ultrasound stimulation was used to treat the rat model of ischemia, and electrical impedance tomography was used to measure impedance during both the acute stage of ischemia and the rehabilitation stage following the stimulation. Electrical impedance tomography results indicated that cerebral impedance increased after the onset of ischemia and decreased following transcranial focused ultrasound stimulation. Furthermore, the stimulation promoted motor function recovery, reduced cerebral infarction volume in the rat model of ischemic stroke, and induced the expression of brain-derived neurotrophic factor in the ischemic brain. Our results also revealed a significant correlation between the impedance of the ischemic brain post-intervention and improvements in behavioral scores and infarct volume. This study shows that daily administration of transcranial focused ultrasound stimulation for 20 minutes to the ischemic hemisphere 24 hours after cerebral ischemia enhanced motor recovery in a rat model of ischemia. Additionally, our findings indicate that electrical impedance tomography can serve as a valuable tool for quantitatively evaluating rehabilitation after ischemic stroke in vivo. These findings suggest the feasibility of using impedance data collected via electrical impedance tomography to clinically assess the effects of rehabilitatory interventions for patients with ischemic stroke.

Effects of Motherwort on Biological Behavior of Brain Tissue in Rats with Ischemic Stroke and its Relationship with Phosphatidylinositol 3-Kinase/Protein Kinase B Signaling Pathway

Background Motherwort has a protective effect on the nervous system and can improve cerebral ischemia–reperfusion injury to a certain extent. However, the effect of motherwort on the biological behavior of the brain tissue of rats with ischemic stroke and its relationship with the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) signaling pathway is still unclear. Purpose Therefore, we will explore the effect of motherwort on the biological behavior of the brain tissue of rats with ischemic stroke and its relationship with the PI3K/AKT signaling pathway. Methods There were 17 model rats in each group, divided into a control group, a model group, and a motherwort (low, medium, and high) dose group. Detect cell proliferation, invasion, and so on, and observe the expression of proteins and genes such as nuclear factor kappa B (NF-κB), AKT, Pl3K, and β-actin. Results After successfully constructing a rat model of ischemic stroke, motherwort can improve neurological damage and cerebral infarction in ischemic stroke and is closely related to PI3K/AKT signaling; in addition, motherwort can upregulate PI3K/AKT signaling and improve neurological damage and cerebral infarct size in ischemic stroke rats to a certain extent, and play a role in protecting neurons. Conclusion The antioxidant and antineuronal apoptosis effects of motherwort can improve neurological damage and cerebral infarction area of ischemic stroke rats by upregulating the expression level of the PI3K/AKT signaling pathway, thereby inhibiting nerve cells. Apoptosis further protects neurons and plays a role in slowing down disease progression.

The Therapeutic Effects of SP-8356, a Verbenone Derivative, with Multimodal Cytoprotective Mechanisms in an Ischemic Stroke Rat Model.

An ischemic cerebral stroke results from the interruption of blood flow to the brain, triggering rapid and complex cascades of excitotoxicity, oxidative stress, and inflammation. Current reperfusion therapies, including intravenous thrombolysis and mechanical thrombectomy, cause further brain injury due to reperfusion-induced cytotoxicity. To date, novel cytoprotective therapies that could address these challenges have yet to be developed, likely due to the limitations of targeting a single pathologic mechanism. To address these unmet clinical needs, we investigated a synthetic verbenone derivative, SP-8356, as a potential multi-target cytoprotective agent for acute ischemic strokes. In transient middle cerebral artery occlusion (MCAO) rats, SP-8356 significantly reduced brain infarct and edema volumes while improving acute neurological deficits in a dose-dependent manner. Furthermore, SP-8356 improved long-term outcomes, particularly by reducing mortality. These potent cytoprotective effects of SP-8356 were achieved by suppressing the excessive production of free radicals and pro-inflammatory cytokines, reducing the infiltration of inflammatory cells, and mitigating increases in blood-brain barrier permeability. Additional research is needed to determine whether co-administration of SP-8356 can extend the therapeutic time window of reperfusion therapies by mitigating ischemia/reperfusion injury.

Novel Rat Model of Embolic Cerebral Ischemia Using a Radiopaque Blood Clot and a Microcatheter Under Fluoroscopy.

Conventional rat models of thromboembolic stroke do not allow control of infarct size or spontaneous recanalization. We aimed to develop a novel rat thromboembolic stroke model that ensures highly reproducible infarct sizes and locations within the MCA territory and does not require arterial ligation. Twenty male Sprague-Dawley rats and two sham-operated rats were included. A microcatheter was navigated from the caudal ventral artery to the internal carotid artery using digital subtraction angiography. A blood clot (diameter, 0.86 mm; length, 3 mm) containing zirconium dioxide was advanced in the catheter. Fluoroscopy was performed at 1, 3, 6, and 24 h after stroke model creation, and TTC staining was conducted at 24 h. Neurological deficit scores were measured. In all embolized rats, the ACA and MCA bifurcation were selective. Median operating time was 6 min. The position of the radiopaque blood clot remained unchanged for 24 h after model creation in 19/20 rats. Median infarct volume was 242 mm3 (IQR, 239-262 mm3). We present a novel rat model of highly reproducible focal infarct in only the MCA territory. Fluoroscopy effectively identified any blood clot migration. This model could contribute to the development of new thrombolytic agents.

Transplantation of human neural stem cells repairs neural circuits and restores neurological function in the stroke-injured brain

Exogenous neural stem cell (NSC) transplantation has become one of the most promising treatment methods for chronic stroke. Recent studies have shown that most ischemia-reperfusion model rats recover spontaneously after injury, which limits the ability to observe long-term behavioral recovery. Here, we used a severe stroke rat model with 150 minutes of ischemia, which produced severe behavioral deficiencies that persisted at 12 weeks, to study the therapeutic effect of neural stem cells on neural restoration in chronic stroke. Our study showed that stroke model rats treated with human neural stem cells had long-term sustained recovery of motor function, reduced infarction volume, long-term human neural stem cell survival, and improved local inflammatory environment and angiogenesis. We also demonstrated that transplanted human neural stem cells differentiated into mature neurons in vivo, formed stable functional synaptic connections with host neurons, and exhibited the electrophysiological properties of functional mature neurons, indicating that they replaced the damaged host neurons. The findings showed that human fetal-derived neural stem cells had long-term effects for neurological recovery in a model of severe stroke, which suggests that human neural stem cells-based therapy may be effective for repairing damaged neural circuits in stroke patients.

High-resolution perfusion imaging in rodents using pCASL at 9.4T.

Adequate perfusion is critical for maintaining normal brain function and aberrations thereof are hallmarks of many diseases. Pseudo-Continuous Arterial Spin Labeling (pCASL) MRI enables noninvasive quantitative perfusion mapping without contrast agent injection and with a higher signal-to-noise ratio (SNR) than alternative methods. Despite its great potential, pCASL remains challenging, unstable, and relatively low-resolution in rodents - especially in mice - thereby limiting the investigation of perfusion properties in many transgenic or other relevant rodent models of disease. Here, we address this gap by developing a novel experimental setup for high-resolution pCASL imaging in mice and combining it with the enhanced SNR of cryogenic probes. We show that our new experimental setup allows for optimal positioning of the carotids within the cryogenic coil, rendering labeling reproducible. With the proposed methodology, we managed to increase the spatial resolution of pCASL perfusion images by a factor of 15 in mice; a factor of 6 in rats is gained compared to the state of the art just by virtue of the cryogenic coil. We also show that the improved pCASL perfusion imaging allows much better delineation of specific brain areas, both in healthy animals as well as in rat and mouse models of stroke. Our results bode well for future high-definition pCASL perfusion imaging in rodents.

A fluorogenic ROS-triggered hydrogen sulfide donor for alleviating cerebral ischemia-reperfusion injury.

Rationale: Cerebral ischemia-reperfusion injury is a severe neurovascular disease that urgently requires effective therapeutic interventions. Recently, hydrogen sulfide (H2S) has garnered significant attention as a potential treatment for stroke; however, the precise and targeted delivery of H2S remains a considerable challenge for its clinical application. Methods: We have developed HSDF-NH2, a novel H2S donor characterized by high selectivity, self-reporting capabilities, and the ability to penetrate the blood-brain barrier (BBB). Results: HSDF-NH2 effectively scavenges reactive oxygen species (ROS) while generating H2S, with emitted fluorescence facilitating the visualization and quantification of H2S release. This compound has demonstrated protective effects against cerebral ischemia-reperfusion (I/R) injury and contributes to the reconstruction of brain structure and function in a rat stroke model (tMCAO/R). Conclusion: As a ROS-responsive, self-reporting, and fluorescent H2S donor, HSDF-NH2 holds considerable promise for the treatment of ischemic diseases beyond stroke.

Pretreatment Effect of Photo-Biomodulation through Alterations of MicroRNAs (21, 124a) in a Rat Model of Ischemic Stroke

Pretreatment Effect of Photo-Biomodulation through Alterations of MicroRNAs (21, 124a) in a Rat Model of Ischemic Stroke

Mild hypercapnia before reperfusion reduces ischemia-reperfusion injury in hyperacute ischemic stroke rat model.

Endovascular thrombectomy has a recanalization rate over 80%; however, approximately 50% of ischemic stroke patients still experience dependency or mortality. Recently, clinical trials demonstrated the benefits of administering neuroprotective agents prior to endovascular thrombectomy. Additionally, recent studies showed neuroprotective effects of mild hypercapnia in patients resuscitated after cardiac arrest. However, its efficacy in ischemic stroke remains unclear. We aimed to investigate whether carbon dioxide (CO2) per-conditioning has neuroprotective effects in rat models with middle cerebral artery occlusion (MCAO). Rat models received intermittent inhalation of mixed gas during the MCAO period. After surgery, behavioral assessments, infarct size measurement, immunohistochemistry, and western blot analysis were performed. We found CO2 per-conditioning reduced infarct size and neurological deficit. The number of 8-hydroxy-2-deoxyguanosine (8-OHdG) positive cells and matrix metalloproteinase 9 (MMP-9)/platelet derived growth factor receptor beta (PDGFRβ) double positive cells were significantly decreased after CO2 per-conditioning. The expressions of tight junction protein and pericytes survival were preserved. This study underscores mild hypercapnia before reperfusion not only reduces neurologic deficit and infarct size, but also maintains the integrity of the blood-brain barrier and neurovascular unit, alongside mitigating oxidative stress in hyperacute stroke rat models. Therapeutic mild hypercapnia before reperfusion is promising and requires further clinical application.

Illustrate the metabolic regulatory mechanism of Taohong Siwu decoction in ischemic stroke by mass spectrometry imaging.

Metabolic dysregulation in the ischemic region has been increasingly recognized as a contributing factor to ischemic stroke pathogenesis. Taohong Siwu decoction (THSWD), a traditional Chinese medicine preparation used to enhance blood circulation, is frequently employed in treating ischemic stroke. However, the metabolic regulatory mechanism underlying the therapeutic effects of THSWD in ischemic stroke remains largely unexplored. In this study, we employed desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to investigate the metabolic changes in the brain tissue of ischemic stroke rat model. Our investigation revealed that 30 metabolites exhibited significant dysregulation in the ischemic brain regions, specifically the cortex and striatum, following ischemic injury. Following the treatment of THSWD, almost all the dysregulated metabolites got different degrees of callback. Further pathway analysis indicated that THSWD might exert its therapeutic effects by restoring energy metabolism, improving neurotransmitter metabolism, recovering polyamine metabolism, and so on. DESI-MSI offers a favorable methodology for investigating the alterations in the spatial distribution and level within the ischemic brain region following treatment with THSWD in ischemic stroke. These findings provide a novel perspective on the underlying mechanisms of the efficacy of THSWD in ischemic stroke treatment.

Dual-tDCS Ameliorates Cerebral Injury and Promotes Motor Function Recovery via cGAS-STING Signaling Pathway in a Rat Model of Ischemic Stroke.

Ischemic stroke is one of the leading causes of death and disability. Dual transcranial direct current stimulation (dual-tDCS) is a promising intervention to treat ischemic stroke, but its efficacy and underlying mechanism remain to be verified. Cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has recently emerged as a key mediator in cerebral injury. However, little is known about the effect of cGAS-STING on neuronal damage in ischemic stroke, and it remains to be studied whether the cGAS-STING pathway is involved in tDCS intervention for ischemic stroke. Therefore, we aimed to investigate whether dual-tDCS can alleviate ischemic brain injury in a rat model of ischemic stroke and if so, whether via cGAS-STING pathway. Middle cerebral artery occlusion (MCAO) was employed to induce a rat model of ischemic stroke. Male SD rats weighing 250-280g were randomly assigned to the Sham, MCAO, Dual-tDCS, Dual-tDCS + RU.521, and Dual-tDCS + 2'3'-cGAMP groups, with 10 rats in each group completing the experiment. Behavioral, morphological, MRI, and molecular biological methods were performed. We found that the cGAS-STING pathway was activated and expressed in neurons after MCAO. Dual-tDCS improved motor function and infarct volume, inhibited neuronal apoptosis, promoted the expression of neurotrophins (BDNF and NGF), CD31, and VEGF, and suppressed inflammation reaction after MCAO via the cGAS-STING pathway. Taken together, dual-tDCS may improve MCAO-induced brain injury and promote the recovery of motor function, resulting from the inhibition of neuronal apoptosis and inflammation reaction, as well as promotion of the expression of nerve plasticity- and angiogenesis-related proteins, via cGAS-STING pathway.

Recovery after human bone marrow mesenchymal stem cells (hBM-MSCs)-derived extracellular vesicles (EVs) treatment in post-MCAO rats requires repeated handling.

Rehabilitation is the only current intervention that improves sensorimotor function in ischemic stroke patients, similar to task-specific intensive training in animal models of stroke. Bone marrow mesenchymal stem cells (BM-MSCs)-derived extracellular vesicles (EVs) are promising in restoring brain damage and function in stroke models. Additionally, the non-invasive intranasal route allows EVs to reach the brain and target specific ischemic regions. Yet unclear is how handling might enhance recovery or influence other therapies such as EVs after stroke. We used the transient middle cerebral artery occlusion (MCAO) model of stroke in rats to assess how intensive handling alone, in the form of sensorimotor behavioral tests, or in combination with an intranasal treatment of EVs restored neurological function and ischemic damage. Handled rats were exposed to a battery of sensorimotor tests, including the modified Neurological Severity Score (mNSS), beam balance, corner, grid walking, forelimb placement, and cylinder tests, together with Magnetic Resonance Imaging (MRI) at 2, 7, 14, 21, and 28 days post-stroke (dps). Handled MCAO rats were also exposed to an intranasal multidose or single dose of EVs. Non-handled rats were evaluated only by mNSS and MRI at 2, 28, and 56 dps and were treated with a single intranasal dose of EVs. Our results showed that handling animals after MCAO is necessary for EVs to work at the tested dose and frequency, and that a single cumulative dose of EVs further improves the neurological function recovered during handling. These results show the importance of rehabilitation in combination with other treatments such as EVs, and highlight how extensive behavioral testing might influence functional recovery after stroke.