Focal Cerebral Ischemia In Rats Research Articles

Abstract WP307: Combinatory Therapy With a PAF-Receptor Antagonist Plus a Lipid Mediator Provides Long-Lasting Protection in Experimental Stroke

Objective: Neuroprotective efficacy observed during short survival periods may not necessarily apply to more extended survival periods, and some stroke-impaired behaviors recover naturally in rodent models 1-2 weeks after stroke. The objective of the present study was to test the hypothesis that acute LAU-0901 plus NPD1-induced neuroprotection endures in animals allowed to survive for several weeks after focal ischemic insult. Two small bioactive molecules were investigated: LAU-0901, a PAF-R antagonist that blocks pro-inflammatory signaling, and neuroprotectin D1 (NPD1), which activates cell-survival pathways, and their combination exerts potent anti-inflammatory activity in the brain. Methods: Male SD rats (290-360g) were subjected to 2h of middle cerebral artery occlusion (MCAo) by the intraluminal filament and treated with vehicle, LAU-0901 (60 mg/kg, IP), NPD1 (222 μg/kg, IV), LAU-0901+NPD1 at 3 h after onset of MCAo. Rats received neurobehavioral examinations during MCAo (60 min) and then on days 1, 2, 3, 7, and weekly during eight weeks survival period, followed by ex vivo MRI on weeks 4 and 8. Results: Physiological variables showed no significant differences among groups. No adverse behavioral side effects were observed after administering LAU-0901, NPD1, or LAU-0901+NPD1. LAU-0901 and NPD1 treatments alone significantly improved the behavior compared to the vehicle group on day 1 (by 32 and 33%), day 7 (38 and 40%), week 4 (38 and 39%), and persisting throughout eight weeks of survival period (by 58 and 44%, respectively). Combinatory treatment with LAU-0901+NPD1 dramatically improved behavior on days 1 (by 37), 2 (by 37%), 3 (by 36%), 7 (40%), and on weeks 4 (by 40%), 5 (44%), 6 (44%), 7 (44%) and 8 (41%) compared to vehicle group. Treatments with LAU-0901, NPD1, and NPD1+RvD1 reduced T2WI lesion volumes on week 4 by 32, 41, and 50% and tissue loss on week 8 by 83, 51, and 50%, respectively, compared to vehicles. Conclusion: These data suggest that LAU-0901 and NPD1 alone provide high-grade neuroprotection in the MCAo model. Combinatory therapy with LAU-0901 plus NPD1 is more effective than the single therapy affording synergistic neuroprotection with improved neurological recovery when administered at 3h after focal cerebral ischemia in rats.

Ramelteon improves blood-brain barrier of focal cerebral ischemia rats to prevent post-stroke depression via upregulating occludin

Post-stroke depression (PSD) negatively affects the prognosis of post-stroke animals. Ramelteon has neuroprotection for chronic ischemia animals, but the effect and the biological mechanism of it on PSD is still unclear. This study explored the effects of ramelteon with prophylactic administration on blood-brain barrier in rats with middle cerebral artery occlusion (MCAO) and the oxygen-glucose deprivation/reperfusion (OGD/R) bEnd.3 cells and found that ramelteon pretreatment improved the depressive-like behaviors and decreased infarct area in MCAO rats. Also, this study found ramelteon pretreatment improved viability and inhibited permeability in OGD/R cells. In addition, this study found that MCP-1, TNF-α, and IL-1 levels were raised in the MCAO rats and that occludin protein and mRNA levels were decreased in the MCAO and the OGD/R models, while the Egr-1 level was up-regulated. All of these were antagonized by ramelteon pretreatment. In addition, overexpression of Egr-1 could reverse the effect of 100 nM ramelteon pretreatment on FITC and occludin levels in OGD/R cells. In short, this study has demonstrated that the protective effect on PSD of ramelteon pretreatment on MCAO rats is related to the development of BBB permeability and that ramelteon regulates occludin to protect the BBB by inhibiting Egr-1.

RETRACTION NOTICE: Effect of 3-Aminobenzamide on the Ultrastructure of Astrocytes and Microvessels after Focal Cerebral Ischemia in Rats.

[This retracts the article DOI: 10.1177/1559325819901242.].

Abstract TP212: Robust Neuroprotection With PAF-R Antagonist Plus AT-NPD1 In Experimental Ischemic Stroke: Dose-response And Therapeutic Window

Objective: We examined the neuroprotective efficacy, including dose-responses and therapeutic window of 1) LAU-0901, receptor antagonist of the bioactive phospholipid mediator platelet-activating factor (PAF-R) that downregulates pro-inflammatory signaling and has been shown efficacy in a stroke model and, 2) AT-NPD1 (Aspirin- triggered NPD1), its synthesis in the brain was discovered upon aspirin + DHA administration (Bazan et al. Exp Neurol., 2012) and induced cell-survival pathways, anti-inflammatory and neuroprotective activity in focal cerebral ischemia. Methods: Male SD rats underwent 2 hours of MCAo. Behavior testing (days 1-7) and ex vivo MRI on day 7 were conducted. In dose-response, rats were treated with LAU-0901 (45 and 60 mg/kg; IP), AT-NPD1 (111, 222, 333 μg/kg; IV), LAU-0901+AT-NPD1 (LAU-0901 at 3h and AT-NPD1 at 3.15h) or vehicle. In the therapeutic window, vehicle LAU-0901 (60 mg/kg), AT-NPD1 (222 μg/kg), and LAU-0901+AT-NPD1 were administered at 3, 4, 5, and 6h after onset of MCAo. Rats were perfused on day 7, and an ex vivo brain MRI was conducted using 11.7 T MRI. Hierarchal region splitting was used to distinguish the core from the penumbra. Results: LAU-0901 and AT-NPD1 treatments alone improved behavior by 40-42% and 20-30%, respectively, and LAU-0901+AT-NPD1 by 40% compared to the vehicle group. T2-weighted imaging (T2WI) volumes were reduced with all doses of LAU-0901 and AT-NPD1 by 73-90% and 67-83% and LAU-0901+AT-NPD1 by 94% compared to vehicle. In the therapeutic window, treatment with LAU-0901 and AT-NPD1 alone, when administered at 3h, improved behavior on day 7 by 35 and 28%. In contrast, LAU-0901+AT-NPD1, when administered at 3, 4, 5, and 6 hours, improved behavior by 50, 56, 33, and 26%. Ischemic core, penumbra, and total lesion volumes were dramatically reduced with LAU-0901+AT-NPD1 when administered at 3, 4, 5, and 6h by 93, 90, 82, and 84% compared to the vehicle. Conclusion: These data suggest that LAU-0901 and AT-NPD1 alone in low doses provide high-grade neuroprotection in the MCAo model. Combination therapy with LAU-0901 and AT-NPD1 is more effective than the single therapy, affording synergistic neuroprotection with improved neurological recovery when administered up to 6 h after focal cerebral ischemia in rats.

Nootropic Activity of Prospekta in a Blind Placebo-Controlled Study in a Model of Focal Cerebral Ischemia in Rats.

Analysis of the pharmacological activity of the original drug Prospekta in a rat model of focal cerebral ischemia revealed its nootropic effect: course treatment in the post-ischemic period led to recovery of the neurological status of animals at the peak of neurological deficit. Evaluation of the therapeutic potential of the drug in morphological and functional CNS disorders allowed us to conclude that it is advisable to carry out further studies of its biological activity at the preclinical stage (the results obtained in animals were successfully confirmed in a clinical trial of drug efficacy in the treatment of moderate cognitive disorders in the early recovery period after ischemic stroke). Studies of the nootropic activity in other pathologies of the nervous system are also promising.

Predicting thrombolytic haemorrhage risk of acute ischemic stroke through angiogenesis/inflammation dual-targeted MR imaging

Ischemic stroke is currently one of the biggest threats to global health due to its high mortality and disability rate. Thrombolysis with intravenous alteplase remains a primary therapy for acute ischemic stroke. Nevertheless, haemorrhage may be triggered to cause secondary victimization to the patients. On the other hand, the compensatory cerebral collaterals developing in response to ischemia stroke help preserve the penumbral area where the neurons are considered to be salvageable. In this context, precisely evaluating the collateral circulation and predicting the thrombolytic risk of stroke are extremely important not only for treatment decision making but also for a good prognosis. Aiming at identifying the ischemic penumbra and precisely predicting the possible thrombolytic haemorrhage risk prior to thrombolytic therapy, we herein report a dual-targeted magnetic resonance imaging (MRI) nanoprobe based on magnetic iron oxide nanoparticles for visualizing both cerebral collateral circulation and ischemic inflammation. Focal cerebral ischemia rat models were adopted for imaging studies on 7.0 Tesla MRI with different sequences. The imaging results revealed that the nanoprobe could target the newly formed collateral vessels and inflammatory lesions in the cerebral ischemic region, which enabled the visualization of the potential haemorrhage sites of thrombolytic therapy apart from the ischemic penumbra. The current studies therefore offer for the first time a noninvasive approach for precisely predicting potential reperfusion haemorrhage through MRI.

MMP-12 knockdown prevents secondary brain damage after ischemic stroke in mice

We previously reported that increased expression of matrix metalloproteinase-12 (MMP-12) mediates blood-brain barrier disruption via tight junction protein degradation after focal cerebral ischemia in rats. Currently, we evaluated whether MMP-12 knockdown protects the post-stroke mouse brain and promotes better functional recovery. Adult male mice were injected with negative siRNA or MMP-12 siRNA (intravenous) at 5 min of reperfusion following 1 h transient middle cerebral artery occlusion. MMP-12 knockdown significantly reduced the post-ischemic infarct volume and improved motor and cognitive functional recovery. Mechanistically, MMP-12 knockdown ameliorated degradation of tight junction proteins zonula occludens-1, claudin-5, and occludin after focal ischemia. MMP-12 knockdown also decreased the expression of inflammatory mediators, including monocyte chemoattractant protein-1, tumor necrosis factor-α, and interleukin-6, and the expression of apoptosis marker cleaved caspase-3 after ischemia. Overall, the present study indicates that MMP-12 promotes secondary brain damage after stroke and hence is a promising stroke therapeutic target.

Para‑hydroxybenzaldehyde against transient focal cerebral ischemia in rats via mitochondrial preservation.

Gastrodia elata (GE) Blume has been widely used for thousands of years to treat various central and peripheral nervous disorders. P-hydroxybenzaldehyde (PHBA) is a chemical component of GE. However, its role and mechanism in transient focal cerebral ischemia remain unclear. The present study aimed to investigate the protective effect of PHBA on middle cerebral artery occlusion (MCAO) rats. A total of 56 Sprague-Dawley male rats were randomly divided into control, model, PHBA-high dose (PHBA-H) and PHBA-low dose (PHBA-L) groups. The MCAO injury model was replicated in all rats except for the control group. In the control group, only the right common carotid artery was isolated without embolization. After treatment with PHBA, the protective effects (neurological deficit score, cerebral index, weight and cerebral infarct) were analyzed. Western blotting was performed to estimate the protein levels of Bcl-2, Bax and Caspase-3. Apoptotic cells were detected using hematoxylin-eosin staining and TUNEL immunofluorescence assay. Mitochondrial oxidative stress indicators, including reactive oxygen species (ROS), malondialdehyde (MDA) and total superoxide dismutase (T-SOD), while dysfunction indicators, including mitochondrial permeability transition pore (MPTP), ATP and cytochrome C oxidase, were measured using commercial kits. The ultrastructure of mitochondria was observed under an electron microscope. Once the model was successful established, the rats in the MCAO group suffered neurological damage (P<0.001), increased cerebral index (P<0.001), decreased body weight (P<0.001) and had severe cerebral infarction (P<0.001). Moreover, the number of apoptotic cells and the levels of ROS (P<0.001) and MDA (P<0.05) in mitochondria and the protein levels of Bax (P<0.001) and cleaved caspase-3 (P<0.001) were increased. The activities of T-SOD (P<0.001) and cytochrome C oxidase (P<0.001) in the mitochondria, ATP content (P<0.05) and Bcl-2 protein level (P<0.001) decreased, MPTP was stimulated to open and mitochondrial structures were damaged (P<0.001). PHBA treatment resulted in a decrease of the neurological deficit score (PHBA-H 24 h, P<0.001; PHBA-H 6 h and PHBA-L 24 h, P<0.01; PHBA-L 6 h, P<0.05), apoptotic cell number (P<0.001), mitochondrial ROS (P<0.001) and MPTP opening (P<0.001), Bax (P<0.01, P<0.001) and cleaved caspase-3 protein expression (P<0.001) in rats. And the expression of Bcl-2 protein (P<0.001) was increased. In addition, the cerebral index (P<0.05), weight loss (P<0.05), infarction rate (P<0.01) and MDA content (P<0.001) were decrease in the PHBA-H group. The level of ATP (P<0.05) and cytochrome C oxidase (P<0.05) and T-SOD activity (P<0.05) of PHBA-H group rats increased, but no significant difference was observed in the PHBA-L group. Overall, PHBA had a protective effect on transient focal cerebral ischemia in normal rats, regulated the expression of Bcl-2, Bax and cleaved caspase-3 proteins and improved the oxidative stress and dysfunction of mitochondria.

Comparison of the efficacies of Huangqi-Danshen herbal pair compatibility with wild-simulated and transplanted Astragali Radix based on a novel metabolomics strategy

In China, Astragali Radix (Huangqi, HQ) has been extensively applied as a bulk medication. Currently, two forms of HQ are available on the market: wild-simulated HQ (WHQ) and transplanted HQ (THQ), However, it is uncertain whether the two are equally effective. This study compared the differences in their effects by investigating the efficacy of the herbal combination of Astragali Radix and Salvia miltiorrhiza (Huangqi-Danshen, HD) in the prevention of focal cerebral ischemia (FCI) rats. To achieve the more accurate differential metabolites related to FCI, we proposed a tissue-targeted metabonomic study in conjunction with a novel screening strategy based on ultra-high performance liquid chromatography coupled with the quadrupole-Exactive mass spectrometry (UHPLC-Q Exactive MS). The appropriate thresholds of four screening factors (variable importance in the projection (VIP), log2 absolute value of fold change (|log2(FC)|), -In(p-value) and ǀp(corr)ǀ) and their best combination were determined by comparing R2X, R2Y, and Q2 of the orthogonal to partial least squares discriminant analysis (OPLS-DA) models. Eleven metabolites were significantly screened and associated with focal cerebral ischemia through the novel metabolomics strategy. The transplanted HD (THD) had a better callback effect on these eleven metabolites compared with the wild-simulated HD (WHD), especially γ-L-Glutamyl-l-glutamic acid, proline, maleic acid, and S-(Formylmethyl)glutathione. Additionally, the optimal WHD and transplanted THD doses were found to be medium and high. Pathway analysis revealed that middle-dose WHD and high-dose THD largely participated in four and six metabolic pathways, respectively. The results further revealed that THD was better than WHD against focal cerebral ischemia. These findings provided a unique perspective on an integrated comparison of the efficacy difference between WHQ and THQ. In addition, the tissue-targeted metabonomic study gave us new insights into the pathological mechanism of focal cerebral ischemia.

Parthenolide modulates cerebral ischemia-induced microglial polarization and alleviates neuroinflammatory injury via the RhoA/ROCK pathway

BackgroundMicroglia can be activated as proinflammatory (M1) phenotypes and anti-inflammatory (M2) phenotypes after stroke. Parthenolide (PTL) has anti-inflammatory and protective effects on neurological diseases, but until now, the exact mechanisms of these processes after stroke have been unclear. The purpose of this study was to determine the effect of PTL on microglial polarization after stroke and its target for inducing microglial polarization. MethodsTriphenyltetrazolium chloride (TTC) staining, hematoxylin-eosin (HE) staining, and neurological evaluation were performed in a focal transient cerebral ischemia rat model. The human microglia exposed to lipopolysaccharide (LPS) was used for in vitro experiments. Microglial polarization was assessed by RT-PCR and immunostaining. Inflammatory cytokine assays and western blotting were used to investigate the molecular mechanisms underlying PTL-mediated microglial polarization in vivo and in vitro. ResultsPTL significantly reduced cerebral infarction and neuronal apoptosis in rats with cerebral ischemia, reduced the level of inflammatory factors and alleviated neurological deficits. PTL treatment decreased the expression of microglia/macrophage markers in M1 macrophages and increased the expression of microglia/macrophage markers in M2 macrophages after stroke, which induced the transformation of microglia cells from the M1 phenotype to the M2 phenotype. Furthermore, PTL significantly reduced RhoA/ROCK-NF-κB pathway activity and downregulated the effects of pentanoic acid (ROCK agonist). ConclusionsPTL has been shown to mediate neuroinflammation and protect against ischemic brain injury by regulating microglial polarization via the RhoA/ROCK pathway.

Endothelial Protection of Vasoactive Intestinal Peptide Enhances Angiogenesis Mediated by eNOS Pathway Following Focal Cerebral Ischemia in Rats

Endothelial Protection of Vasoactive Intestinal Peptide Enhances Angiogenesis Mediated by eNOS Pathway Following Focal Cerebral Ischemia in Rats

Neuroprotective Effect of Alpha-Pinene on Focal Cerebral Ischemia in Rats

Neuroprotective Effect of Alpha-Pinene on Focal Cerebral Ischemia in Rats

Neuroprotective efficacy of N-t-butylhydroxylamine (NtBHA) in transient focal ischemia in rats.

The pharmacological or toxicological activities of the degradation products of drug candidates have been unaddressed during the drug development process. Ischemic stroke accounts for 80% of all strokes and is responsible for considerable mortality and disability worldwide. Despite decades of research on neuroprotective agents, tissue plasminogen activators (t-PA), a thrombolytic agent, remains the only approved acute stroke pharmacological therapy. NXY-059, a free radical scavenger, exhibited striking neuroprotective properties in preclinical models and met all the criteria established by the Stroke Academic Industry Roundtable (STAIR) for a neuroprotective agent. In phase 3 clinical trials, NXY-059 exhibited significant neuroprotective effects in one trial (SAINT-I), but not in the second (SAINT-II). Some have hypothesized that N-t-butyl hydroxylamine (NtBHA), a breakdown product of NXY-059 was the actual neuroprotective agent in SAINT-I and that changes to the formulation of NXY-059 to prevent its breakdown to NtBHA in SAINT -II was the reason for the lack of efficacy. We evaluated the neuroprotective effect of NtBHA in N-methyl-D-aspartate (NMDA)-treated primary neurons and in rat focal cerebral ischemia. NtBHA significantly attenuated infarct volume in rat transient focal ischemia, and attenuated NMDA-induced cytotoxicity in primary cortical neurons. NtBHA also reduced free radical generation and exhibited mitochondrial protection.

COMPREHENSIVE ASSESSMENT OF NEUROLOGICAL DEFICIT AND ITS CORRECTION WITH PIR-10 COMPOUND IN EXPERIMENTAL FOCAL CEREBRAL ISCHEMIA OF RATS

Introduction: Correction of motor dysfunction resulting from focal cerebral ischemia is one of the significant problems of pharmacology and experimental therapy. Pyrimidine derivatives in the experiment on rats previously showed cerebroprotective activity, as a result of which it was decided to test the PIR-10 compound for the ability to reduce neurological deficit. Methods: A study was conducted to assess the effect of pyrimidine derivative (PIR-10 50 mg/kg) on neurological deficiency in the conditions of focal cerebral ischemia in rats. The study used mature male Wistar rats weighing 220-240 g (n=40). Focal cerebral ischemia was reproduced by coagulation of the left middle cerebral artery (anesthesia chloralhydrate 350 mg/kg). Neurological deficits were assessed using the McGraw, Combs and D'alecy, Garcia scales. Results: The studied compound PIR-10 contributes to the reduction of neurological deficits in all selected schools in comparison with the control group of animals (McGraw by 68% (p&lt;0,05), Combs and D'alecy by 4,3 times (p&lt;0,05), Garcia by 84% (p&lt;0,05)). In addition, the results obtained after administration of PIR-10 to rats showed a statistically significantly difference from the group of rats receiving a reference drug cavinton. However, complete recovery of motor functions after modeling focal cerebral ischemia was not observed in any group of rats. Conclusion: The PIR10 compound is able to partially correct the neurological deficit that occurs in conditions of cerebral circulatory insufficiency, surpassing the activity of the reference drug cavinton.

Protection of Vasoactive Intestinal Peptide on the Blood-Brain Barrier Dysfunction Induced by Focal Cerebral Ischemia in Rats

ObjectiveTo investigate the effects of vasoactive intestinal peptide on the blood brain barrier function after focal cerebral ischemia in rats. Materials and methodsRats were intracerebroventricular injected with vasoactive intestinal peptide after a two hours middle cerebral artery occlusion. Functional outcome was studied with the neurological severity score. The brain edema and the infarction were evaluated via histology. The blood brain barrier permeability was assessed using Evans Blue dye injection method. We also measure the apoptosis of brain microvascular endothelial cells and brain levels of B-cell leukemia-2 protein by immunohistochemical analysis and western blotting, respectively. ResultsIn contrast to the cases treated with vehicle at 72 h after middle cerebral artery occlusion, the treatment with vasoactive intestinal peptide significantly (P < 0.05) reduced the neurological severity score, the brain edema and infarct volume. The Evans Blue leakage and brain water content were obviously reduced (P < 0.05) in vasoactive intestinal peptide-treated rats compared with those of control rats at 72 and 96 h after stroke. In addition, vasoactive intestinal peptide decreased the numbers of terminal deoxynucleotidyl transferase-mediated dUTP-nick end labeling positive endothelial cells and increased the protein levels of B-cell leukemia-2 in the ischemic hemisphere at 72 h after ischemia. ConclusionsOur data suggest that treatment with vasoactive intestinal peptide ameliorates the blood brain barrier function, contributing to reduce in brain damage both morphologically and functionally in the ischemic rat. This amelioration may be associated with attenuation in apoptosis of brain microvascular endothelial cells by increased B-cell leukemia-2 expression.

Vagus nerve stimulation alleviated cerebral ischemia and reperfusion injury in rats by inhibiting pyroptosis via \u03b17 nicotinic acetylcholine receptor

Cumulative evidence suggests that pyroptosis, a new sort of programmed cell death, is closely related to cerebral ischemia/reperfusion (I/R) injury. Our previous studies have testified that vagus nerve stimulation (VNS) was involved in many different neuroprotective and neuroplasticity pathways via α7 nicotinic acetylcholine receptor (α7nAchR), a vital node of the cholinergic anti-inflammatory pathway during cerebral I/R injury. We aimed to determine the neuroprotective effects of VNS through α7nAchR-mediated inhibition of pyroptosis. Focal cerebral ischemic stroke rat models were obtained by middle cerebral artery occlusion for 120 min. Expression of the NLRP3 inflammasome was evaluated using western blotting and immunofluorescence (IF) staining. The neurological deficit score, infarct volume, TUNEL staining findings, transmission electron microscopy findings, and expression of inflammatory cytokines were assessed 3 days after I/R injury. Our findings suggested that the protein expression levels of NLRP3, GSDMD-N, cleaved caspase-1, and ASC gradually increased until they peaked on day 3 after I/R injury. VNS inhibited the expression of pyroptosis-related molecules and decreased the number of pyroptotic cells and membrane pores. Administration of α7nAchR-antagonist and agonist helped in further assessment of the role of α7nAchR in pyroptosis. α7nAchR-agonist mimicked VNS’s neuroprotective effects on the improvement of neurological deficits, the reduction of infarct volumes, and the inhibition of neuronal pyroptosis after cerebral I/R injury. Conversely, the neuroprotection provided by VNS could be reversed by the administration of α7nAchR-antagonist. In conclusion, VNS-induced neuroprotection via inhibition of neuronal pyroptosis was α7nAchR-dependent, highlighting the pivotal role of α7nAChR in suppressing cellular pyroptosis and neuroinflammation. These findings may allow a better understanding of treatment principles for cerebral I/R injury.

Abstract WP235: Docosanoids Protect Inflammation-induced Brain Damage And Lead To Neurological Recovery In Experimental Stroke

Objective: Cerebral ischemia initiates lipid peroxidation, uncompensated oxidative stress, and neuronal damage. We investigated the neuroprotective bioactivity of docosanoid (DOC) mediators: Neuroprotectin D1 (NPD1), Resolvin D1 (RvD1), and their combination (NPD1+RvD1) against experimental ischemic stroke. These lipid mediators are biosynthesized “on-demand” in response to stroke onset to resolve neuroinflammation and restore homeostasis. This study investigated the dose-response and therapeutic window in a model of focal cerebral ischemia. Methods: Male SD rats received 2h of middle cerebral artery occlusion (MCAo). Neurological score was evaluated on days 1, 2, 3, and 7, followed by an ex vivo MRI on day 7. In dose-response study, rats were treated with NPD1 (111, 222, and 333μg/kg), RvD1 (111, 222, and 333μg/kg), NPD1 + RvD1 or vehicle (n=4-5 per group). All treatments were administered IV at 3h after the onset of MCAo. In the therapeutic window study, vehicle, NPD1 (222 μg/kg), RvD1 (222 μg/kg), NPD1+RvD1 were administered IV at 3, 4, 5, and 6 h after onset of MCAo. Results: No adverse behavioral side effects were observed after drugs administration. NPD1 (111, 222, and 333μg/kg) treatment alone greatly improved neurological scores (by 32-35%) and RvD1 (111, 222, and 333μg/kg) alone (by 31-35%) vs vehicle group on day 7. The neuroprotective effect was enhanced using the NPD1+ RvD1, which improved total neurological scores on days 1-7 by 25-40% vs vehicle. Ischemic core, penumbra, and total lesion volumes (computed from T2WI) were reduced with NPD1+RvD1 by 69, 70, and 67% vs vehicle. Therapeutic window: treatments with NPD1 and RvD1 alone when administered at 3h improved behavior on day 7 by 35%. Combinatory NPD1+RvD1 treatment improved behavior when administered at 3h (by 56%), 4h (by 23%), 5h (by 26%), and 6 h (by 28%), vs vehicle. Conclusion: We show that NPD1, RvD1 alone provides high-grade neuroprotection against inflammation and elicit neurological recovery in the MCAo model. Combination therapy with NPD1 and RvD1 is more effective than the single therapy when administered up to 6h after focal cerebral ischemia in rats. Thus, we hypothesize that these treatments may potentially be used in treating focal ischemic stroke in the clinical setting.

Gastrodin injection alleviates lung injury caused by focal cerebral ischemia in rats through NGF/TrkA pathway-mediated activation of the anti-inflammatory pathway

To investigate the therapeutic mechanism of gastrodin injection for alleviating lung injury caused by focal cerebral ischemia in rats and the role of the NGF-TrkA pathway in mediating this effect. Forty SD rats were equally randomized into normal group, sham-operated group, model group and gastrodin group, and in the latter two groups, rat models of focal cerebral ischemia were established by embolization of the right middle cerebral artery. After successful modeling, the rats were treated with intraperitoneal injection of gastrodin injection at the daily dose of 10 mg/kg for 14 days. After the treatment, the wet/dry weight ratio of the lung tissue was determined, the pathological changes in the lung tissue were observed using HE staining, and the levels of IL-10 and TNF-α in the arterial blood were detected with ELISA. The expressions of NF-κB p65 and TNF-α in the lung tissue were detected with Western blotting, and the expressions of NGF and TrkA were detected using immunohistochemical staining and Western blotting. Compared with the normal control and sham-operated groups, the rats in the model group showed obvious inflammatory lung injury, significantly increased wet/ dry weight ratio of the lungs (P < 0.01), increased TNF-α level in arterial blood (P < 0.01), and significantly up-regulated protein expressions of NF-κB p65 (P < 0.01), TNF-α (P < 0.01), NGF (P < 0.05) and TrkA(P < 0.05) in the lung tissue. Treatment with gastrodin injection obviously alleviated lung inflammation, decreased the wet/dry weight ratio of the lungs (P < 0.05), and significantly lowered TNF-α level (P < 0.01) and increased IL-10 level in the arterial blood in the rat models (P < 0.01); gastrodin injection also significantly decreased the protein expressions of NF-κB p65 and TNF-α (P < 0.05) and up-regulated the expressions of NGF and TrkA in the lung tissue of the rats (P < 0.05). The NGF/TrkA pathway may participate in cerebral ischemia-induced inflammatory lung injury, which can be obviously alleviated by gastrodin through the activation of the anti-inflammatory pathway mediated by the NGF/TrkA pathway.

RETRACTED ARTICLE: Inhibition of Long non-coding RNA zinc finger antisense 1 improves functional recovery and angiogenesis after focal cerebral ischemia via microRNA-144-5p/fibroblast growth factor 7 axis

Statement of Retraction Tong Li, Bai Ling Qing, Yan Deng, Xian Ting Que, Cheng Zhi Wang, Hua Wen Lu, Shao Hua Wang & Zi Jun Wang (2022) Inhibition of Long non-coding RNA zinc finger antisense 1 improves functional recovery and angiogenesis after focal cerebral ischemia via microRNA-144-5p/fibroblast growth factor 7 axis, Bioengineered, 13:1, 1702-1716, DOI: 10.1080/21655979.2021.2018093 Since publication, significant concerns have been raised about the integrity of the data and reported results in the article. When approached for an explanation, the authors did not provide their original data or any necessary supporting information. As verifying the validity of published work is core to the integrity of the scholarly record, we are therefore retracting the article. All authors listed in this publication have been informed. We have been informed in our decision-making by our editorial policies and the COPE guidelines. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.

NEP1‑40 promotes myelin regeneration via upregulation of GAP‑43 and MAP‑2 expression after focal cerebral ischemia in rats.

Axon regeneration after lesions to the central nervous system (CNS) is largely limited by the presence of growth inhibitory molecules expressed in myelin. Nogo-A is a principal inhibitor of neurite outgrowth, and blocking the activity of Nogo-A can induce axonal sprouting and functional recovery. However, there are limited data on the expression of Nogo-A after CNS lesions, and the mechanism underlying its influences on myelin growth remains unknown. The aim of the present study was to observe the time course of Nogo-A after cerebral ischemia/reperfusion in rats using immunohistochemistry and western blot techniques, and to test the effect of its inhibitor Nogo extracellular peptide 1–40 (NEP1-40) on neural plasticity proteins, growth-associated binding protein 43 (GAP-43) and microtubule associated protein 2 (MAP-2), as a possible mechanism underlying myelin suppression. A classic model of middle cerebral artery occlusion (MCAO) was established in Sprague-Dawley rats, which were divided into three groups: i) MCAO model group; ii) MCAO + saline group; and iii) MCAO + NEP1-40 group. Rats of each group were divided into five subgroups by time points as follows: days 1, 3, 7, 14 and 28. Animals that only received sham operation were used as controls. The Nogo-A immunoreactivity was located primarily in the cytoplasm of oligodendrocytes. The number of Nogo-A immunoreactive cells significantly increased from day 1 to day 3 after MCAO, nearly returning to the control level at day 7, increased again at day 14 and decreased at day 28. Myelin basic protein (MBP) immunoreactivity in the ipsilateral striatum gradually decreased from day 1 to day 28 after ischemia, indicating myelin loss appeared at early time points and continuously advanced during ischemia. Then, intracerebroventricular infusion of NEP1-40, which is a Nogo-66 receptor antagonist peptide, was administered at days 1, 3 and 14 after MCAO. It was observed that GAP-43 considerably increased from day 1 to day 7 and then decreased to a baseline level at day 28 compared with the control. MAP-2 expression across days 1–28 significantly decreased after MCAO. Administration of NEP1-40 attenuated the reduction of MBP, and upregulated GAP-43 and MAP-2 expression at the corresponding time points after MCAO compared with the MCAO + saline group. The present results indicated that NEP1-40 ameliorated myelin damage and promoted regeneration by upregulating the expression of GAP-43 and MAP-2 related to neuronal and axonal plasticity, which may aid with the identification of a novel molecular mechanism of restriction in CNS regeneration mediated by Nogo-A after ischemia in rats.