Artery Occlusion In Rats Research Articles

A Factor XIa Inhibitor Engineered from Banded Krait Venom Toxin: Efficacy and Safety in Rodent Models of Arterial and Venous Thrombosis.

Activated factor XI (FXIa) is an important antithrombotic drug target. Clinical and pre-clinical data have demonstrated that its inhibition attenuates thrombosis with minimal risk of excessive bleeding. We isolated Fasxiator from the venom of banded krait Bungarus fasciatus and subsequently engineered FasxiatorN17R,L19E, with improved affinity (Ki = 0.9 nM) and selectivity towards FXIa. Here, we assess the in vivo efficacy and bleeding risk of rFasxiatorN17R, L19E in pre-clinical animal models. Rats injected intravenously (i.v.) with bolus rFasxiatorN17R, L19E showed the specific in vivo attenuation of the intrinsic coagulation pathway, lasting for at least 60 min. We performed the in vivo dose-ranging experiments for rFasxiatorN17R, L19E as follows: FeCl3-induced carotid artery occlusion in rats (arterial thrombosis); inferior vena cava ligation in mice (venous thrombosis); tail bleeding time in both rats and mice (bleeding risk). Head-to-head comparisons were made using therapeutic dosages of unfractionated heparin (UFH) and low-molecular-weight heparin (LMWH) for arterial and venous thrombosis, respectively. In the arterial thrombosis model, 2 mg/kg i.v. rFasxiatorN17R,L19E achieved a similar antithrombotic efficacy to that of UFH, with >3-fold lower bleeding time. In the venous thrombosis model, the 10 mg/kg subcutaneous (s.c.) injection of rFasxiatorN17R,L19E achieved similar efficacy and bleeding levels to those of LMWH enoxaparin. Overall, rFasxiatorN17R,L19E represents a promising molecule for the development of FXIa-targeting anticoagulants.

Retinal Oxygen Delivery and Metabolism Response to Hyperoxia During Bilateral Common Carotid Artery Occlusion in Rats.

PurposeThe purpose of the current study was to test the hypothesis that responses of total retinal blood flow (TRBF), inner retinal oxygen delivery (DO2), metabolism (MO2), and extraction fraction (OEF) to hyperoxia are higher after minutes of bilateral common carotid artery occlusion (BCCAO) as compared to days of BCCAO.MethodsTwenty-eight rats were subjected to BCCAO for 30 minutes (n = 12), 1 day (n = 8), or 3 days (n = 8). Eight of the 12 rats were also evaluated at baseline, prior to BCCAO. During room air breathing (RA) and 100% O2 inspiration (hyperoxia), blood flow and phosphorescence lifetime imaging were performed to measure TRBF and vascular O2 contents, respectively. DO2, MO2, and OEF were calculated from these measurements.ResultsAfter 30 minutes or 3 days of BCCAO, TRBF did not differ between RA and hyperoxia conditions (P ≥ 0.14) but decreased under hyperoxia after 1 day (P = 0.01). Compared to RA, DO2 and MO2 were increased under hyperoxia after 30 minutes of BCCAO (P ≤ 0.02). Additionally, MO2 was decreased under hyperoxia after 1 day of BCCAO (P = 0.04). OEF was decreased under hyperoxia compared to RA (P < 0.001). Under hyperoxia, TRBF and DO2 were reduced after all BCCAO durations compared to baseline (P ≤ 0.04), whereas MO2 did not differ from baseline after 30 minutes of BCCAO (P = 1.00).ConclusionsThe findings indicate that hyperoxia introduced minutes after ischemia can reduce DO2 impairments and potentially return MO2 to approximately normal values. This information contributes to the knowledge of the effect of supplemental oxygen intervention on TRBF, DO2, MO2, and OEF outcomes after variable durations of ischemia.

Changes in Brain Electrical Activity after Transient Middle Cerebral Artery Occlusion in Rats.

Objectives. Ischemic stroke is a leading cause of death and disability worldwide. To search for new therapeutic and pharmacotherapeutic strategies, numerous models of this disease have been proposed, the most popular being transient middle cerebral artery occlusion. Behavioral and sensorimotor testing, biochemical, and histological methods are traditionally used in conjunction with this model to assess the effectiveness of potential treatment options. Despite its wide overall popularity, electroencephalography/electrocorticography is quite rarely used in such studies. Materials and methods. In the present work, we explored the changes in brain electrical activity at days 3 and 7 after 30- and 45-min of transient middle cerebral artery occlusion in rats. Results. Cerebral ischemia altered the amplitude and spectral electrocorticogram characteristics, and led to a reorganization of inter- and intrahemispheric functional connections. Ischemia duration affected the severity as well as the nature of the observed changes. Conclusions. The dynamics of changes in brain electrical activity may indicate a spontaneous partial recovery of impaired cerebral functions at post-surgery day 7. Our results suggest that electrocorticography can be used successfully to assess the functional status of the brain following ischemic stroke in rats as well as to investigate the dynamics of functional recovery.

Neuroprotection of Oral Edaravone on Middle Cerebral Artery Occlusion in Rats.

Edaravone has been widely used in the treatment of acute ischemic stroke. However, there has been no oral preparation of edaravone in the clinic. In this study, we assessed the effect and possible mechanisms of oral edaravone on the middle cerebral artery occlusion (MCAO) model in rats. Highly bioavailable form of novel edaravone formulation developed using self-nanomicellizing solid dispersion strategy which showed up to 16.1-fold improved oral bioavailability was considered oral edaravone. The male rats (n = 84) were randomly divided into sham; model; oral edaravone in low dose (10mg/kg), medium dose (20mg/kg), and high dose (30mg/kg); and edaravone by intraperitoneal administration group (IP group, 10mg/kg). Rats were treated with different drugs 5h after the operation, twice a day for 7days. The behavioral data were dose-dependently improved by oral edaravone and sensorimotor functions of the high dose group were similar to those of the edaravone by IP route group. Furthermore, oral edaravone significantly reduced cerebral infarction area and downregulated the levels of caspase-3, GFAP, Iba1, 3-NT, and 4-HNE, whereas upregulated those of Vamp-2 and Map-2 in a dose-dependent manner. Especially effect of the high dose on these molecules was equal to that of edaravone by IP administration. Taken together, our data suggest that the improvement of sensorimotor deficits by oral edaravone in high doses after ischemia is similar to that in edaravone by IP administration. Neuroprotection of oral edaravone is at least partial by minimizing oxidative stress, the overactivation of glial cells, and the levels of the apoptosis-associated proteins, and alleviating synaptic damage in a dose-dependent manner.

Silent information regulator 1 ameliorates oxidative stress injury via PGC-1α/PPARγ-Nrf2 pathway after ischemic stroke in rat

ObjectiveAstrocytes mediate brain defense against oxidative stress-induced injury. Silent information regulator 1 (SIRT1) has anti-oxidative stress effects in many diseases and is highly expressed in astrocytes. However, the neuroprotective effects of SIRT1 on astrocytes after cerebral ischemia/reperfusion injury are unclear. Therein, we aim to investigate the protective effect of SIRT1 on oxidative stress injury after ischemic stroke and possible mechanisms. MethodsWe evaluated the effects of SIRT1 in astrocytes after cerebral ischemia/reperfusion injury using oxygen-glucose deprivation/recovery (OGD/R) in astrocytes in vitro and middle cerebral artery occlusion in rats in vivo. siRNA was injected intracerebroventricularly 24 h before Middle cerebral artery (MCA) occlusion (MCAO)/reperfusion(R) to silence SIRT1. ResultsSIRT1 knockdown reduced cell viability, increased oxidative stress, and decreased PGC-1α, PPARγ, Nrf2, heme oxygenase (HO)−1, and NAD(P)H: oxidoreductase-1 (NQO1) expression. Moreover, SIRT1 knockdown also suppressed PGC-1α activity, the PGC-1α/PPARγ interaction, and the PPARγ/PPRE interaction. Similarly, in our in vivo experiments, SIRT1 overexpression and PGC-1α or PPARγ knockdown reduced PGC-1α, PPARγ, Nrf2, HO−1, and NQO1 protein expression and blocked the PGC-1α/PPARγ interaction. SIRT1 overexpression plus PPARγ knockdown inhibited the interaction of PPARγ with PPRE. Nrf2 knockdown blocked Nrf2 expression and downstream proteins induced by SIRT1 overexpression. ConclusionOverall, our data indicated that SIRT1 directly mediated the PGC-1α/PPARγ pathway in response to focal cerebral ischemia/reperfusion-induced neurological deficit, providing insights into the treatment of focal cerebral ischemia/reperfusion injury.

Relation between the Severity of the Sensorimotor Cortical Edema with Cell Swelling and the Duration of Common Carotid Artery Occlusion in Rats (Morphometric Study)

The aim of the study. To examine the changes in structure and morphometry in sensorimotor cortical edema with cell swelling in mature white rats after common carotid artery occlusion of various durations.Material and methods. Acute ischemia was modeled on white adult Wistar rats by 20-, 30- and 40-min occlusion of the common carotid arteries (CCA). Histological (hematoxylin-eosin and Nissl staining), immunohistochemical (NSE, MAP-2, GFAP) and morphometric methods were used. Morphometry was assessed on hematoxylin and eosin-stained specimens using ImageJ 1.53 plug-ins (Find Maxima, Find Foci). Statistical hypothesis testing (nonparametric criteria) was performed using Statistica 8.0 software.Results. In the sensorimotor cortex (SMC) of white rats after 20, 30 and 40 minutes of CCA occlusion the signs of cytotoxic brain edema appeared, focal destructive and adaptive changes of neurons and astroglia evolved. The edema persisted throughout the observation period (7 days). The increase in the relative area, the number of cell swelling zones and their hydration (pixel brightness) was significant. On days 1 and 3 after CCA occlusion, some of the SMC astrocyte processes underwent destruction. Subpial and perivascular zones suffered to a greater extent. Mild and moderate (after unilateral 30-min CCA occlusion) to moderate and severe (after bilateral 40-min CCA occlusion) scattered structural and functional changes of the SMC with large areas of clearing in the «porous» neuropil, severe perivascular and perineuronal edema of the astrocyte processes developed. The latter was associated with a moderate reduction of the total neuronal density.Conclusion. After occlusion of CCA, signs of edema with cellular swelling appeared in the SMC amid dystrophic and necrotic pyramidal neurons and activated neuroglial cells. To a greater extent, the signs of brain swelling were evident three days after bilateral 40-min occlusion of CCA.

Molecular Magnetic Resonance Imaging of Vascular Inflammation After Recanalization in a Rat Ischemic Stroke Model.

Brain imaging has become central in the management of acute ischemic stroke. Detection of parenchymal injury and perfusion enables characterization of the extent of ischemic damage, which guides treatment decision-making. Additional assessment of secondary events, such as inflammation, which may particularly arise after recanalization, may improve diagnosis and (supplementary) treatment selection. Therefore, we developed and tested a molecular magnetic resonance imaging (MRI) approach for in vivo detection of vascular inflammation after transient middle cerebral artery occlusion in rats. Molecular MRI of VCAM-1 (vascular cell adhesion molecule-1) expression was performed with a targeted contrast agent, in addition to MR angiography, and diffusion-, T2- and perfusion-weighted MRI, from 1 hour until 96 hours after transient middle cerebral artery occlusion in rats. VCAM-1 expression, detected with susceptibility-weighted MRI, was significantly enhanced at 6 hours after recanalization as compared with 1-hour postrecanalization, coinciding with a transient decline in perfusion after initial hyperperfusion. VCAM-1 levels declined after 24 hours, but remained elevated, particularly in lesion borderzones. The implementation of molecular MRI of vascular inflammation into imaging protocols after acute ischemic stroke could provide complementary information that may guide treatment decision-making before and after recanalization therapy.

Electroacupuncture Promotes the Survival of the Grafted Human MGE Neural Progenitors in Rats with Cerebral Ischemia by Promoting Angiogenesis and Inhibiting Inflammation.

Stem cells have the potential as a regenerative therapy for cerebral ischemia by improving functional outcomes. However, cell transplantation has some limitations, including a low rate of the grafted cell survival. There is still a major challenge of promoting the harmonious symbiosis between grafted cells and the host. Acupuncture can effectively improve the functional outcome after cerebral ischemia. The present study evaluated the therapeutic effects and explored the mechanism of combined medial ganglionic eminence (MGE) neural progenitors differentiated from human embryonic stem cells (hESCs) with electroacupuncture (EA) in a bilateral common carotid artery occlusion (2VO) rat model. The results showed that EA could promote the survival of the grafted MGE neural progenitors differentiated from hESCs and alleviate learning and memory impairment in rats with cerebral ischemia. This may have partially resulted from inhibited expression of TNF-α and IL-1β and increased vascular endothelial growth factor (VEGF) expression and blood vessel density in the hippocampus. Our findings indicated that EA could promote the survival of the grafted MGE neural progenitors and enhance transplantation therapy's efficacy by promoting angiogenesis and inhibiting inflammation.

Effect of cinnamon on antioxidant content and ZO-1 gene expression in brain following middle cerebral artery occlusion in rats receiving high-fat diet

Effect of cinnamon on antioxidant content and ZO-1 gene expression in brain following middle cerebral artery occlusion in rats receiving high-fat diet

Nociceptive receptors are expressed differently in trigeminal nociception after lingual nerve injury and unilateral external carotid artery occlusion in rats

ObjectivesTo investigate the different changes in nociceptive activity between two animal models of trigeminal neuropathic pain: unilateral external carotid artery ischemic reperfusion and lingual nerve crush in rats. DesignIn this study, changes in nociceptive activity were investigated in unilateral external carotid artery ischemic reperfusion and lingual nerve crush models of trigeminal neuropathic pain in rats. Field excitatory postsynaptic potentials (fEPSPs) evoked by capsaicin application on the tongue of rats were recorded in the trigeminal nucleus caudalis. In addition, immunohistochemistry was performed in the trigeminal ganglia and trigeminal nucleus caudalis. ResultsThe fEPSP in unilateral external carotid artery ischemic reperfusion and lingual nerve crush rats was irregular relative to that in sham rats. In particular, the fEPSP spike in lingual nerve crush rats had a higher amplitude and shorter duration than that in sham rats. Unilateral external carotid artery ischemic reperfusion and lingual nerve crush also increased c-fos expression in the trigeminal nucleus caudalis. Upregulation of transient receptor potential vanilloid 1 in trigeminal ganglion was observed in unilateral external carotid artery ischemic reperfusion and lingual nerve crush rats, whereas upregulation of purinergic receptor subtype 3 in trigeminal ganglion was observed only in lingual nerve crush rats. ConclusionsAlthough unilateral external carotid artery ischemic reperfusion and lingual nerve crush similarly increased nociceptive activity at the trigeminal nucleus caudalis, the fEPSPs and expression of nociceptive peripheral afferent neurons were different. Therefore, direct and indirect nerve injuries apparently induced the same nociceptive activity by different signaling responses dependent on nociceptive receptors.

Ischemic-hypoxic preconditioning enhances the mitochondrial function recovery of transplanted olfactory mucosa mesenchymal stem cells via miR-181a signaling in ischemic stroke.

Cerebral ischemia/reperfusion injury causes a series of intricate cascade reactions in brain tissue causing apoptosis and proinflammatory programmed cell death known as pyroptosis of nerve cells. The dysfunction of target organelle mitochondria plays a key role in the process of neuronal apoptosis and pyroptosis. Mesenchymal stem cells (MSCs) have been widely used in the experimental or clinical treatment of various ischemic diseases, but the therapeutic efficacy of MSCs on cerebral ischemia-reperfusion injury need to be improved. We successfully cultured olfactory mucosa MSCs (OM-MSCs) to obtain a better source of seed cells. In this way, the therapeutic potential of OM-MSCs transplantation has been evaluated for ischemic stroke using an optimized culture scheme in vitro. Ischemic-hypoxic preconditioned OM-MSCs (IhOM-MSCs) were used to treat a neuron model of oxygen-glucose deprivation/reperfusion and the middle cerebral artery occlusion in rats. These results demonstrated that IhOM-MSCs mediated the upregulation of the downstream target genes GRP78 and Bcl-2 by miR-181a to protect mitochondrial function and inhibit apoptosis and pyroptosis of neurons in the ischemia/reperfusion injury model. Thus, IhOM-MSCs transplantation may be an effective therapy of ischemic stroke in the future.

Evaluation of the Effectiveness of Post-Stroke Metformin Treatment Using Permanent Middle Cerebral Artery Occlusion in Rats.

Stroke is the second leading cause of death worldwide. Treatment options for ischemic stroke are limited, and the development of new therapeutic agents or combined therapies is imperative. Growing evidence suggests that metformin treatment, due to its anti-inflammatory action, exerts a neuroprotective effect against ischemia/reperfusion-induced brain damage. Experimental assessment has typically been performed in models of cerebral transient ischemia followed by long-term reperfusion. The aim of this study was to evaluate the neuroprotective effect of metformin treatment after permanent middle cerebral artery occlusion (pMCAO) without reperfusion in rats. Neurological deficits were assessed using the Longa scale, which offers a graded scale on body movement following pMCAO. Both infarct size and brain oedema area were measured by staining with 2,3,5-triphenyltetrazolium chloride. The number of neurons and total and activated microglia, as well as interleukin 10 (IL-10) production, in brain sections were evaluated by immunohistochemical staining. Our results show that metformin treatment improves the neurological state and reduces infarct size after 120 h of pMCAO. Metformin also prevents neuronal loss in the ischemic cortex but not in the striatum after 48 h of pMCAO. Moreover, post-stroke treatment with metformin significantly decreases the number of total and activated microglia at 48 h. The anti-inflammatory effect of metformin is associated with increased IL-10 production at 48 h after pMCAO. The results of the present study suggest that post-stroke treatment with metformin exerts anti-inflammatory and neuroprotective effects in a pMCAO model.

Effects of Early Rehydration on Brain Perfusion and Infarct Core after Middle Cerebral Artery Occlusion in Rats.

Imaging evidence for the effect of rehydration on cerebral perfusion and brain ischemia has never been proposed in the literature. This study aimed to test the hypothesis that early rehydration treatment can improve cerebral perfusion and decrease infarct volume, consequently reducing mortality of dehydrated stroke animals. Methods: Thirty dehydrated experimental rats were randomly assigned to either a rehydration or control group after middle cerebral artery occlusion (MCAO). Diffusion-weighted imaging and dynamic contrast enhancement perfusion imaging were performed at 30 min and 6 h after MCAO using a 9.4T MR imaging scanner to measure the infarct volume and brain perfusion. Results: The survival rates after the first MRI scan were 91.7% for the rehydration group and 58.3% for the control group (p = 0.059). The survival rates after the second MRI scan were 66.7% for the rehydration group, and 8.3% of the control group survived (p = 0.003). The infarct volume of the rehydration group was significantly smaller than control group at 30 min after MCAO (p = 0.007). The delay time and time to maximum were significantly shorter in the rehydration group at 30 min (p = 0.004 and 0.035, respectively). Conclusions: The findings suggest that early rehydration therapy can decrease the infarct volume, shorten the delay time of cerebral perfusion, and increase survival of dehydrated ischemic-stroke rats. This preliminary study provided imaging evidence that more intensive early hydration therapies and reperfusion strategies may be necessary for acute stroke patients with dehydrated status.

Casticin protected against neuronal injury and inhibited the TLR4/NF-κB pathway after middle cerebral artery occlusion in rats.

Although stroke is a major human neurological disease, there is a paucity of effective neuroprotectants that can improve its treatment. Casticin is a natural monomer drug with many biological effects such as anti‐inflammatory and anti‐tumor actions. However, it is not clear whether it has a neuroprotective effect in ischemic stroke. In this study, the neuroprotective effect of casticin in a rat middle cerebral artery occlusion (MCAO) model was investigated. Results showed that casticin reduced the volume of the cerebral infarction, mNSS scores, swimming distance, time to find the submerged platform, and serum concentrations of TNF‐α, TGF‐β, IL‐6 in MCAO rats. Moreover, casticin also decreased the expression of TLR4, NF‐κB p65, and NF‐κB p50 proteins and reversed the reduced expression of IκB protein in the brain tissue of MCAO rats. The in vitro study revealed that casticin decreased apoptosis of OGD/R‐PC12 cells, reduced the expression of TLR4, NF‐κB p65, and NF‐κB p50, while increased IκB protein expression. In conclusion, casticin improved the neurological functions of MCAO rats via inhibiting the TLR4/NF‐κB pathway and might have the potential to be developed into a neuroprotective agent for stroke patients.

Abstract P751: Global Analyses of Protein and Microrna Cargo in Neural Stem Cell Derived-Exosomes After Brain Ischemia

Background: Adult neurogenesis facilitates brain remodeling after stroke. Exosomes derived from neural stem cells (NSCs) promote ischemic neurovascular remodeling including angiogenesis and axonal outgrowth, potentially by transferring their cargo proteins and miRNAs to recipient cells. However, cargo profiles of proteins and miRNAs in NSC exosomes have not been investigated. Methods: Exosomes were isolated from supernatants of cultured NSCs harvested from the subventricular zone of rats subjected to 7 day middle cerebral artery occlusion (MCAO) and non-MCAO rats, respectively. Mass spectrometry and miRNA array were utilized to determine the protein and miRNA profiles of NSC-derived exosomes (NSC-Exos). Bioinformatic pathway analyses were performed using Ingenuity Pathway Analysis (IPA). Results: Exosome markers and size distribution (50-200nm) were validated with Western blot, transmission electron microscopy and Nanosight measurements, respectively. Proteomics analysis yielded a total of 1,770 proteins in ischemic NSC-Exos. Bioinformatics analysis identified 24, 23 and 23 proteins that were related to neuronal cell proliferation, migration and differentiation, respectively. Intriguingly, enrichment signaling pathway analysis revealed cargo proteins in ischemic NSC-Exos were highly associated with dysfunction, membrane, and permeability of mitochondrion, indicating a critical role of extracellular mitochondrion in stroke-induced neurogenesis. In addition, 318 miRNAs were detected in ischemic NSC-Exos. Gene ontology analysis demonstrated that differentially expressed miRNAs between ischemic and non-ischemic NSC-Exos were highly related to inflammation, cell proliferation, cell cycle, and differentiation. The top 3 upregulated miRNAs including miR-106b, miR-542,miR-125b were validated in ischemic NSC-Exos using RT-PCR. The functions of these miRNAs are related to the induction of angiogenesis. Summary/Conclusion: Our results for the first time demonstrate that ischemic NSC-Exos contain a robust profile of protein and miRNA effectors, which may provide new insights into the function of NSC-Exos in stroke-induced neurogenesis and potentially lead to new therapeutic targets against stroke.

The Hsp90 Inhibitor 17-DMAG Attenuates Hyperglycemia-Enhanced Hemorrhagic Transformation in Experimental Stroke.

Introduction Hemorrhagic transformation (HT) is one of the most common complications of ischemic stroke which is exacerbated by hyperglycemia. Oxidative stress, inflammatory response, and matrix metalloproteinases (MMPs) have been evidenced to play a vital role in the pathophysiology of HT. Our previous study has reported that 17-DMAG, an Hsp90 inhibitor, protects the brain against ischemic injury via inhibiting inflammation and reducing MMP-9 after ischemia. However, whether 17-DMAG would attenuate HT in hyperglycemic middle cerebral artery occlusion (MCAO) rats is still unknown. Methods Acute hyperglycemia was induced by an injection of 50% dextrose. Rats were pretreated with 17-DMAG before MCAO. Infarction volume, hemorrhagic volume neurological scores, expressions of inflammatory molecules and tight junction proteins, and activity of MMP-2 and MMP-9 were assessed 24 h after MCAO. Results 17-DMAG was found to reduce HT, improve neurological function, and inhibit expressions of inflammatory molecules and the activation of MMPs at 24 h after MCAO. Conclusion These results implicated that Hsp90 could be a novel therapeutic target in HT following ischemic stroke.

Delayed Treatment with Human Dental Pulp Stem Cells Accelerates Functional Recovery and Modifies Responses of Peri-Infarct Astrocytes Following Photothrombotic Stroke in Rats

Dental pulp contains multipotent mesenchymal stem cells that improve outcomes when administered early after temporary middle cerebral artery occlusion in rats. To further assess the therapeutic potential of these cells, we tested whether functional recovery following stroke induced by photothrombosis could be modified by a delayed treatment that was initiated after the infarct attained maximal volume. Photothrombosis induces permanent focal ischemia resulting in tissue changes that better reflect key aspects of the many human strokes in which early restoration of blood flow does not occur. Human dental pulp stem cells (approximately 400 × 103 viable cells) or vehicle were injected into the infarct and adjacent brain tissue of Sprague-Dawley rats at 3 days after the induction of unilateral photothrombotic stroke in the sensorimotor cortex. Forepaw function was tested up to 28 days after stroke. Cellular changes in peri-infarct tissue at 28 days were assessed using immunohistochemistry. Rats treated with the stem cells showed faster recovery compared with vehicle-treated animals in a test of forelimb placing in response to vibrissae stimulation and in first attempt success in a skilled forelimb reaching test. Total success in the skilled reaching test and forepaw use during exploration in a Perspex cylinder were not significantly different between the 2 groups. At 28 days after stroke, rats treated with the stem cells showed decreased immunolabeling for glial fibrillary acidic protein in tissue up to 1 mm from the infarct, suggesting decreased reactive astrogliosis. Synaptophysin, a marker of synapses, and collagen IV, a marker of capillaries, were not significantly altered at this time by the stem-cell treatment. These results indicate that dental pulp stem cells can accelerate recovery without modifying initial infarct formation. Decreases in reactive astrogliosis in peri-infarct tissue could have contributed to the change by promoting adaptive responses in neighboring neurons.

Thrombus Imaging Using 3D Printed Middle Cerebral Artery Model and Preclinical Imaging Techniques: Application to Thrombus Targeting and Thrombolytic Studies.

Diseases with the highest burden for society such as stroke, myocardial infarction, pulmonary embolism, and others are due to blood clots. Preclinical and clinical techniques to study blood clots are important tools for translational research of new diagnostic and therapeutic modalities that target blood clots. In this study, we employed a three-dimensional (3D) printed middle cerebral artery model to image clots under flow conditions using preclinical imaging techniques including fluorescent whole-body imaging, magnetic resonance imaging (MRI), and computed X-ray microtomography (microCT). Both liposome-based, fibrin-targeted, and non-targeted contrast agents were proven to provide a sufficient signal for clot imaging within the model under flow conditions. The application of the model for clot targeting studies and thrombolytic studies using preclinical imaging techniques is shown here. For the first time, a novel method of thrombus labeling utilizing barium sulphate (Micropaque®) is presented here as an example of successfully employed contrast agents for in vitro experiments evaluating the time-course of thrombolysis and thus the efficacy of a thrombolytic drug, recombinant tissue plasminogen activator (rtPA). Finally, the proof-of-concept of in vivo clot imaging in a middle cerebral artery occlusion (MCAO) rat model using barium sulphate-labelled clots is presented, confirming the great potential of such an approach to make experiments comparable between in vitro and in vivo models, finally leading to a reduction in animals needed.

Pretreatment with Shenxiong Drop Pill induces AQP4- mediated neuroprotective effect on middle cerebral artery occlusion in rats

Purpose: To investigate the neuroprotective effect of Shenxiong Drop Pill (SXDP) pretreatment on rats with middle cerebral artery occlusion (MCAO) in rats, and the mechanism involved.Methods: Ninety-nine SD rats were randomly assigned to 4 groups: control group, MCAO group, shamoperated group and SXDP group. The MCAO model was established via thread occlusion. Rats in the SXDP group was administered SXDP 7 days before induction of MCAO. Neurological deficit score (NDS) was determined using Bederson's neurological behavioral scoring method, while cerebral infarction volume was measured using TTC staining. Integrated optical density (IOD) of Nissl Body was evaluated via Nissl staining. Brain water content was measured using dry-wet method. The expression level of AQP4 in brain tissues was determined using immunocytochemistry.Results: The SXDP treatment resulted in significant reduction in NDS, marked improvement in IOD of Nissl Body, and significant reductions in cerebral infarction volume, brain water content, and expression level of AQP4, relative to control (p&lt; 0.05).Conclusion: These results suggest that SXDP pretreatment exerts neuroprotective effect against cerebral ischemia in rats by decreasing in cerebral edema through a mechanism involving downregulation of the expression of AQP4.&#x0D; Keywords: Middle cerebral artery occlusion, Cerebral ischemia, Aquaporins-4, Cerebral edema, Neuroprotection

The Neuroprotective Effects of Danggui-Shaoyao San on Vascular Cognitive Impairment: Involvement of the Role of the Low-Density Lipoprotein Receptor-Related Protein.

Effective drugs for treating dementia are still rare. Danggui-Shaoyao San (DSS), a traditional Chinese medicine, has been widely used in oriental countries for the treatment of various gynecological diseases. Many studies reported that DSS could ameliorate cognitive impairment. In this study, we aimed to investigate the underlying mechanism of DSS on vascular cognitive impairment (VCI) rats. Chronic cerebral hypoperfusion (CCH) is one of the main causes of VCI. CCH resulted in a chain of pathological process, including neuroinflammation, neuronal apoptosis, and oxidative stress. The most widely used animal model of VCI is permanent bilateral common carotid artery occlusion in rats. In this research, we determined whether DSS attenuated cognitive impairment by targeting I kappa B kinase (IKK)/nuclear factor of kappa B (NF-κB) signal pathway in VCI rats. Morris water maze and fear conditioning tests results indicated that DSS [7.2 g/(kg·d)] could improve learning and memory ability in VCI rats. We also found DSS significantly elevated the levels of low-density lipoprotein receptor-related protein 1 (LRP1) in the brain of VCI rats and this might indirectly target the IKK/NF-κB signal pathway to exert inhibitory effect on neuroinflammation, neuronal apoptosis, and oxidative stress in VCI rats. The present researches indicated that DSS might attenuate cognitive impairment by targeting IKK/NF-κB signal pathway in VCI rats and DSS might be a promising agent on VCI.