Beneficial Role of Rosuvastatin in Blood-Brain Barrier Damage Following Experimental Ischemic Stroke

Acupuncture Extended the Thrombolysis Window by Suppressing Blood-Brain Barrier Disruption and Regulating Autophagy-Apoptosis Balance after Ischemic Stroke

BACKGROUND

Ischemic stroke (IS) is one of the leading causes of death and disability worldwide. The narrow therapeutic window (within 4.5 h) and severe hemorrhagic potential limits therapeutic efficacy of recombinant tissue type plasminogen activator (rt-PA) intravenous thrombolysis for patients. Xingnao Kaiqiao (XNKQ) acupuncture is an integral part of traditional Chinese medicine, specifically designed to address acute ischemic stroke by targeting key acupoints such as Shuigou (GV26) and Neiguan (PC6). In this study, we explored the therapeutic potential of XNKQ acupuncture in extending the time window for thrombolysis and interrogated the molecular mechanisms responsible for this effect.

METHODS

The effect of extending the thrombolysis window by acupuncture was evaluated via TTC staining, neuronal score evaluation, hemorrhagic transformation assay, and H&E staining. RNA sequencing (RNA-seq) technology was performed to identify the therapeutic targets and intervention mechanisms of acupuncture. Evans blue staining and transmission electron microscopy were used to assess blood-brain barrier (BBB) integrity. Immunofluorescence staining and co-immunoprecipitation were performed to evaluate the level of autophagy and apoptosis and validate their interactions with BBB endothelial cells.

RESULTS

Acupuncture alleviated infarction and neurological deficits and extended the thrombolysis window to 6 h. The RNA-seq revealed 16 potential therapeutic predictors for acupuncture intervention, which related to suppressing inflammation and restoring the function of BBB and blood vessels. Furthermore, acupuncture suppressed BBB leakage and preserved tight junction protein expression. The protective effect was associated with regulation of the autophagy-apoptosis balance in BBB endothelial cells. Acupuncture intervention dissociated the Beclin1/Bcl-2 complex, thereby promoting autophagy and reducing apoptosis.

CONCLUSION

XNKQ acupuncture could serve as an adjunctive therapy for rt-PA thrombolysis, aiming to extend the therapeutic time window and mitigate ischemia-reperfusion injury. Acupuncture suppressed BBB disruption by regulating the autophagy-apoptosis balance, which in turn extended the therapeutic window of rt-PA in IS. These findings provide a rationale for further exploration of acupuncture as a complementary candidate co-administered with rt-PA.

Statins and cognition: Modifying factors and possible underlying mechanisms

Statins are a class of widely prescribed drugs used to reduce low-density lipoprotein cholesterol (LDL-C) and important to prevent cardiovascular diseases (CVD). Most statin users are older adults with CVD, who are also at high risk of cognitive decline. It has been suggested that statins can alter cognitive performance, although their positive or negative effects are still debated. With more than 200 million people on statin therapy worldwide, it is crucial to understand the reasons behind discrepancies in the results of these studies. Here, we review the effects of statins on cognitive function and their association with different etiologies of dementia, and particularly, Alzheimer’s disease (AD). First, we summarized the main individual and statin-related factors that could modify the cognitive effects of statins. Second, we proposed the underlying mechanisms for the protective and adverse effects of statins on cognitive performance. Finally, we discussed potential causes of discrepancies between studies and suggested approaches to improve future studies assessing the impact of statins on dementia risk and cognitive function.

Efficacy of Rosuvastatin Combined with rt-PA Intravenous Thrombolytic Therapy for Elderly Acute Ischemic Stroke Patients

Background

Acute ischemic stroke (AIS) is a fatal and disabling disease. Given the unsatisfactory results by current treatment strategies, optimizing the treatment of AIS is still an urgent problem to be solved.

Objective

To determine the therapeutic efficacy of rosuvastatin (ROS) combined with thrombolytic therapy using recombinant tissue plasminogen activator (rt-PA) on senile AIS patients and analyze its effects on serum inflammatory responses and neurological function.

Methods

A retrospective study was conducted on 150 senile AIS patients who visited the Longmen County People's Hospital between January 2019 and June 2021. Of them, 100 cases treated by ROS combined with rt-PA intravenous thrombolytic therapy (ivTT) were set as the observation group and the rest 50 cases receiving rt-PA alone were included in the control group. Intergroup comparisons were conducted with respect to the following parameters: neurological function (National Institutes of Health Stroke Scale, NIHSS; Scandinavian Stroke Scale, SSS), serum neuron-specific enolase (NSE) and high-sensitivity C-reactive protein (hs-CRP), therapeutic efficacy, incidence of adverse reactions, and patient satisfaction.

Results

The observation group had lower NIHSS and SSS scores and serum NSE and hs-CRP than the control group. In addition, the observation group was found with a higher overall response rate, higher patient satisfaction, and fewer adverse reactions.

Conclusion

ROS combined with rt-PA ivTT can better enhance the therapeutic efficacy of elderly patients with AIS, improve their neurological function, and reduce serum inflammatory responses.

Integrated Network Pharmacology and UPLC/Q-TOF-MS Screen System to Exploring Anti-Inflammatory Active Components and Mechanism of Shunaoxin Pills

Background

Chronic cerebral ischemia (CCI) is a pathological condition associated with a variety of cerebrovascular diseases. Shunaoxin pills (SNX) are a traditional Chinese medicine (TCM) used to improve blood circulation. However, its multicomponent and multitarget features make it difficult to decipher the molecular mechanisms.

Objective

Thus, in this study, we aimed to identify the key anti-inflammatory components of SNX as markers for standardization and quality control and the potential pharmacological mechanisms of SNX in the treatment of CCI by network pharmacology to provide scientific evidence of its clinical efficacy.

Methods

We evaluated the anti-inflammatory effect of SNX using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectroscopy (UPLC/Q-TOF-MS) combined with a dual-luciferase reporter assay for nuclear factor kappa B (NF-κB) inhibition to identify the active components in SNX. In addition, key pathways involved in the anti-inflammatory effect of SNX were predicted using a network pharmacology approach, and some crucial proteins and pathways were further validated by Western blotting.

Results

Shunaoxin pills inhibited NF-κB through tumor necrosis factor-α (TNF-α) stimulation in 293T cells. The therapeutic effect may be related to 10 pathways regulated by ligustilide, ferulic acid, ligustrazine, and senkyunolide I. It was further confirmed that ligustilide could reduce the inflammatory response by inhibiting the phosphorylation of p38 and 3-phosphoinositide-dependent kinase 1 (PDK1).

Conclusions

Ligustilide, senkyunolide I, ferulic acid, and ligustrazine could be used as anti-inflammatory Q-markers to control the quality of SNX, and p38 and PDK1 might be potential targets of SNX in the treatment of CCI.

Long-Term Use of Statins Lowering the Risk of Rehospitalization Caused by Ischemic Stroke Among Middle-Aged Hyperlipidemic Patients: A Population-Based Study

Background: The long-term effects of statin use on rehospitalization due to ischemic stroke (reHospIS) in hyperlipidemic patients are still unknown. Therefore, we aimed to assess the long-term risks of reHospIS for hyperlipidemic patients who were taking statins and nonstatin lipid-lowering medicines on a regular basis.

Methods and Materials: The National Health Insurance Research Database in Taiwan was used to conduct a 6-year cohort study of patients >45 years old (n = 9,098) who were newly diagnosed with hyperlipidemia and hospitalized for the first or second time due to ischemic stroke (IS). The risk of reHospIS was assessed using Cox proportional hazards regression model.

Results: Nonstatin lipid-lowering medicines regular users were associated with a higher risk of reHospIS compared to stains users (hazard ratio, HR = 1.29–1.39, p < 0.05). Rosuvastatin was the most preferred lipid-lowering medicine with lower HRs of reHospIS in hyperlipidemic patients whether they developed diabetes or not. Bezafibrate regular users of hyperlipidemic patients developing diabetes (HR = 2.15, p < 0.01) had nearly 50% lower reHospIS risks than those without diabetes (HR = 4.27, p < 0.05). Age, gender, drug dosage, comorbidities of diabetes and heart failure (HF), and characteristics of the first hospitalization due to IS were all adjusted in models. Moreover, increasing trends of HRs of reHospIS were observed from Rosuvastatin, nonstatin lipid-lowering medicines, Lovastatin, and Gemfibrozil to Bezafibrate users.

Conclusion: Statins were associated with long-term secondary prevention of reHospIS for hyperlipidemic patients. Rosuvastatin seemed to have the best protective effects. On the other hand, Bezafibrate appears to be beneficial for hyperlipidemic patients developing diabetes. Further research into the combination treatment of statin and nonstatin lipid-lowering medicines in hyperlipidemic patients developing diabetes is warranted.

A comparison of the effects of monotherapy with rosuvastatin, atorvastatin or ezetimibe versus combination treatment with rosuvastatin-ezetimibe and atorvastatin-ezetimibe on the integrity of vascular endothelial cells damaged by oxidized cholesterol

Dyslipidemia, atherosclerosis, and cardiovascular events can be prevented, or treated, using statins, alone or in combination with ezetimibe. The aim of the study was to compare the direct pleiotropic effects of two commonly-used statins (atorvastatin, rosuvastatin), ezetimibe and their combinations on endothelial cells damaged by oxidized cholesterol. HUVEC cultures were stimulated for 20 hours with atorvastatin (5 μM; 2793 ng/mL), rosuvastatin (10 μM; 4815 ng/mL), ezetimibe (1.22 μM; 500 ng/mL), atorvastatin plus ezetimibe (5 μM + 1.22 μM; 2793 ng/mL + 500 ng/mL) and rosuvastatin plus ezetimibe (10 μM + 1.22 μM; 4815 ng/mL + 500ng/mL) in separate groups, with or without 25-hydroxycholesterol pre-incubation (24.83 μM; 10 μg/mL; four hours then washout). HUVEC integrity was measured in the RTCA-DP xCELLigence system. The mRNA expression and protein levels of ZO-1, OCLN, ICAM-1 were analyzed by real-time PCR and ELISA. Pre-incubation with 25-OHC resulted in decreased endothelial cell integrity (p<0.001), decreased expression of ZO-1 mRNA (p<0.05) and protein levels (p<0.05), OCLN mRNA (p<0.05) and protein levels (p<0.05) and increased ICAM-1 mRNA (p<0.001) and protein levels (p<0.001) compared to the control group. Incubation with rosuvastatin (12h p<0.01; 24h p<0.001) and atorvastatin (only 12h p<0.05) restored HUVEC integrity. Subsequent incubation with rosuvastatin increased ZO-1 mRNA (p<0.001) and protein (p<0.001) levels. Subsequent addition of ezetimibe increased ZO-1 mRNA level (p<0.001) but not protein level. Furthermore, only incubation with rosuvastatin increased OCLN mRNA (p<0.05) and protein (p<0.05) levels. In each drug-stimulated group, both ICAM-1 mRNA and protein levels were reduced after initial incubation with oxysterol (p<0.05). 25-hydroxycholesterol disrupts endothelial integrity, decreases the mRNA and protein levels of tight junction, and increases those of intercellular adhesion molecules. Both rosuvastatin and atorvastatin can improve endothelial integrity, but only rosuvastatin can completely abolish the effect of oxysterol. The combination of statins with ezetimibe has less direct effect on the endothelial barrier than the statins alone.

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

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

Xiao-Xu-Ming decoction prevented hemorrhagic transformation induced by acute hyperglycemia through inhibiting AGE-RAGE-mediated neuroinflammation

Stroke is one of the leading causes of death worldwide. Hemorrhagic transformation (HT) is a common serious complication of ischemic stroke (IS) and is related to poor prognosis. Hyperglycemia after stroke is associated with the occurrence of HT and seriously affects the clinical treatment of stroke. Our previous experiments demonstrated that the Xiao-Xu-Ming decoction effective components group (XXMD), which is a Chinese medicine formula reconstituted by active ingredients, has multiple pharmacological effects in the treatment of IS. However, the effects of XXMD on HT after IS remain unclear. Thus, we investigated the preventive effects of XXMD on hyperglycemia-induced HT and further explored the underlying mechanism. Acute hyperglycemia combined with the electrocoagulation cerebral ischemia model was used to establish the HT model. XXMD (37.5, 75, 150 mg/kg/d) was given by gavage for 5 days. Network pharmacology was used to predict potential targets and pathways of XXMD in HT occurrence, and further studies confirmed the related targets. The results showed that hyperglycemia aggravated neurological deficits and blood-brain barrier (BBB) disruption, leading to intracerebral hemorrhage. Pretreatment with XXMD improved neurological function and BBB integrity and inhibited HT occurrence. Network pharmacology revealed that AGE-RAGE-mediated neuroinflammation may be associated with hyperglycemia-induced HT. Further studies confirmed that hyperglycemia activated the AGE-RAGE signaling pathway, increased the expression of HMGB1, TLR4 and p-p65, and induced the release of inflammatory factors and neutrophil infiltration, leading to HT. XXMD could inhibit AGE-RAGE-mediated neuroinflammation. These findings indicated that pretreatment with XXMD alleviated hyperglycemia-induced HT, which may be associated with the inhibition of AGE-RAGE-mediated neuroinflammation. Therefore, XXMD may be a potential therapeutic drug for HT.

Extracellular Vesicles: Novel Roles in Neurological Disorders

Exosomes are small extracellular vesicles (EVs) secreted by almost all cells, which have been recognized as a novel platform for intercellular communication in the central nervous system (CNS). Exosomes are capable of transferring proteins, nucleic acids, lipids, and metabolites between neurons and glial cells, contributing to CNS development and maintenance of homeostasis. Evidence shows that exosomes originating from CNS cells act as suppressors or promoters in the initiation and progression of neurological disorders. Moreover, these exosomes have been shown to transfer molecules associated with diseases through the blood-brain barrier (BBB) and thus can be detected in blood. This unique feature enables exosomes to act as potential diagnostic biomarkers for neurological disorders. In addition, a substantial number of researches have indicated that exosomes derived from mesenchymal stem cells (MSCs) have repair effects on neurological disorders. Herein, we briefly introduce the roles of exosomes under physiological and pathological conditions. In particular, novel roles of exosomes as potential diagnostic biomarkers and therapeutic tools for neurological disorders are highlighted.

Network Pharmacology-Based Approach to Revealing Biological Mechanisms of Qingkailing Injection against IschemicStroke: Focusing on Blood-Brain Barrier

Ischemic stroke is the most common type of cerebrovascular accident worldwide. It causes long-term disability and death. Qingkailing (QKL) injection is a traditional Chinese patent medicine which has been clinically applied in the treatment of ischemic stroke for nearly thirty years. In the present study, network pharmacology combined with experimentation was used to elucidate the mechanisms of QKL. ADME screening and target prediction identified 62 active compounds and 275 targets for QKL. Topological screening of the protein-protein interaction (PPI) network was used to build a core PPI network consisting of 408 nodes and 17,830 edges. KEGG enrichment indicated that the main signaling pathway implicated in ischemic stroke involved hypoxia-inducible factor-1 (HIF-1). Experimentation showed that QKL alleviated neurological deficits, brain infraction, blood-brain barrier (BBB) leakage, and tight junction degeneration in a mouse ischemic stroke model. Two-photon laser scanning microscopy was used to evaluate BBB permeability and cerebral microvessel structure in living mice. HIF-1α, matrix metalloproteinase-9 (MMP-9), and tight junction proteins such as occludin, zonula occludins-1 (ZO-1), claudin-5, and VE-Cadherin were measured by western blotting. QKL upregulated ZO-1 and downregulated HIF-1α and MMP-9. QKL has a multiapproach, multitarget, and synergistic effect against ischemic stroke.

Targeting E. coli invasion of the blood-brain barrier for investigating the pathogenesis and therapeutic development of E. coli meningitis

Escherichia coli is the most common Gram-negative bacillary organism causing neonatal meningitis. Escherichia coli meningitis remains an important cause of mortality and morbidity, but the pathogenesis of E. coli penetration of the blood-brain barrier remains incompletely understood. Escherichia coli entry into the brain occurs in the meningeal and cortex capillaries, not in the choroid plexus, and exploits epidermal growth factor receptor (EGFR) and cysteinyl leukotrienes (CysLTs) for invasion of the blood-brain barrier. The present study examined whether EGFR and CysLTs are inter-related in their contribution to E. coli invasion of the blood-brain barrier and whether counteracting EGFR and CysLTs is a beneficial adjunct to antibiotic therapy of E. coli meningitis. We showed that (a) meningitis isolates of E. coli exploit EGFR and CysLTs for invasion of the blood-brain barrier, (b) the contribution of EGFR is upstream of that of CysLTs, and (c) counteracting EGFR and CysLTs as an adjunctive therapy improved the outcome (survival, neuronal injury and memory impairment) of animals with E. coli meningitis. These findings suggest that investigation of host factors contributing to E. coli invasion of the blood-brain barrier will help in enhancing the pathogenesis and development of new therapeutic targets for E. coli meningitis in the era of increasing resistance to conventional antibiotics.

The Effect of Exosomes Derived from Bone Marrow Stem Cells in Combination with Rosuvastatin on Functional Recovery and Neuroprotection in Rats After Ischemic Stroke

Rosuvastatin, known as a cholesterol-lowering agent, has been used as an alternative therapy after the onset of stroke. In this study, neuroprotection and functional recovery of exosomes in combination with rosuvastatin have been investigated. Sixty adult male Wistar rats were subjected to middle cerebral artery occlusion (MCAO). Exosome at the dose of 100 μg and/or rosuvastatin at the dose of 20 mg/kg/day for 7 days were administered to rats as a therapeutic strategy. The elevated body swing test (EBST) and Garcia score were conducted as behavioral tests for the measurement of functional recovery. The histopathological and immunohistochemical analyses were also performed for the assessment of infarcted volume and neuroprotection in the brain of rats. The real-time PCR method was carried out to determine the relative expressions of the NLRP-3 and NLRP1 genes. After 7 days of treatment with exosome and rosuvastatin in rats which underwent MCAO, the decrease in infarct volume of the animals treated with exosome was more pronounced compared with those treated only with exosome. The combination therapy remarkably lowered the size of infarct volume. Our observation was confirmed by the downregulation of the NLRP1 and NLRP3 genes in response to combinatory treatment of rats induced by MCOA, denoting a lower rate of cell death. The number of GFAP-positive cells were reduced in the exosome-treated group compared with the MCAO group. The rate of lipid peroxidation was measured by malondialdehyde (MDA) levels which demonstrated a significant reduction of MDA in the exosome- and rotuvastatin-treated groups when compared with the MCAO group. However, the levels of the SOD enzyme did not significantly alter when the treatment groups were compared with the MCAO group. According to our findings, it seems that the use of exosomes and rosuvastatin, as a novel treatment regimen, might promote neurological recovery after the onset of stroke.

The effect of HMG-CoA reductase inhibitors on thrombolysis-induced haemorrhagic transformation

Thrombolysis-induced haemorrhagic transformation is the most challenging preventable complication in thrombolytic therapy. This condition is often associated with poor functional outcome and long-term disease burden. Statins, or 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, are controversially suggested to either increase or decrease the odds of better primary outcomes compared to treatment without statins after thrombolysis in patients or animals; statins are thought to act by influencing lipid levels, the inflammatory response, blood brain barrier permeability and cell apoptosis. Statins are the cornerstone of secondary prevention of cardiovascular and cerebrovascular diseases. However, the role of statins in acute phase stroke, and the necessity of their use, remains unclear. Currently, whether statins can increase the risk of haemorrhagic transformation is of great concern for patients treated with tissue plasminogen activator (t-PA). Herein, we thoroughly summarize the recent advances that address whether the administration of statins in ischaemic stroke increases haemorrhagic transformation in patients or animals who received thrombolysis at an early stage and the related mechanisms. This review will provide more clinical and preclinical evidence to address questions regarding the exercise of caution in the use of high dose statins in patients who received thrombolysis and if low dose statins may be beneficial in decreasing thrombolysis-induced haemorrhagic transformation.

Dysfunction of 67-kDa Laminin Receptor Disrupts BBB Integrity via Impaired Dystrophin/AQP4 Complex and p38 MAPK/VEGF Activation Following Status Epilepticus

Status epilepticus (SE, a prolonged seizure activity) impairs brain-blood barrier (BBB) integrity, which results in secondary complications following SE. The non-integrin 67-kDa laminin receptor (67-kDa LR) plays a role in cell adherence to laminin (a major glycoprotein component in basement membrane), and participates laminin-mediated signaling pathways including p38 mitogen-activated protein kinase (p38 MAPK). Thus, we investigated the role of 67-kDa LR in SE-induced vasogenic edema formation in the rat piriform cortex (PC). SE diminished 67-kDa LR expression, but increased laminin expression, in endothelial cells accompanied by the reduced SMI-71 (a rat BBB barrier marker) expression. Astroglial 67-kDa LR expression was also reduced in the PC due to massive astroglial loss. 67-kDa LR neutralization led to serum extravasation in the PC concomitant with the reduced SMI-71 expression. 67-kDa LR neutralization also decreased expressions of dystrophin and aquaporin-4 (AQP4). In addition, it increased p38 MAPK phosphorylation and expressions of vascular endothelial growth factor (VEGF), laminin and endothelial nitric oxide synthase (eNOS), which were abrogated by SB202190, a p38 MAPK inhibitor. Therefore, our findings indicate that 67-kDa LR dysfunction may disrupt dystrophin-AQP4 complex, which would evoke vasogenic edema formation and subsequent laminin over-expression via activating p38 MAPK/VEGF axis.

Cryptotanshinone Attenuates Oxygen-Glucose Deprivation/ Recovery-Induced Injury in an in vitro Model of Neurovascular Unit

Cryptotanshinone (CTs), an active component isolated from the root of Salvia miltiorrhiza (SM), has been shown to exert potent neuroprotective property. We here established an oxygen-glucose deprivation/recovery (OGD/R)-injured Neurovascular Unit (NVU) model in vitro to observe the neuroprotective effects of CTs on cerebral ischemia/reperfusion injury (CIRI), and explore the underlying mechanisms. CTs was observed to significantly inhibit the OGD/R-induced neuronal apoptosis, and decease the activation of Caspase-3 and the degradation of poly-ADP-ribose polymerase (PARP), as well as the increase of Bax/Bcl-2 ratio in neurons under OGD/R condition. The inhibitory effects of CTs on neuron apoptosis were associated with the blocking of mitogen-activated protein kinase (MAPK) signaling pathway. CTs also remarkably ameliorated OGD/R-induced reduction of transepithelial electrical resistance (TEER) values and the increase of transendothelial permeability coefficient (Pe) of sodium fluorescein (SF) by upregulating the expression of ZO-1, Claudin-5, and Occludin in brain microvascular endothelial cells (BMECs), which might be related to the down-regulation of matrix metalloproteinase (MMP)-9 expression. Based on these findings, CTs may play a neuroprotective role in OGD/R injure in NVU models in vitro by inhibiting cell apoptosis and alleviating the damage of blood-brain barrier (BBB).

Epidermal growth factor treatment has protective effects on the integrity of the blood-brain barrier against cerebral ischemia injury in bEnd3 cells

Tight junctions (TJs) serve an important role in maintaining the integrity of the blood-brain barrier (BBB), while neurological disorders, including ischemic stroke, induce TJ disruption and increase BBB permeability; results include edema formation and hemorrhage transformation. Cerebral endothelium protection presents a promising approach in ischemic stroke therapy. In the current study, protective effects of the epidermal growth factor (EGF) on ischemia-induced disruption of BBB integrity were examined using an oxygen-glucose deprivation (OGD) model in bEnd3 cells. Expression levels of claudin-5 and TJ protein-1 (ZO-1) were determined by reverse transcription-quantitative polymerase chain reaction and western blot analysis. Cell viability was evaluated by cell counting kit-8 assay and the endothelial permeability of Lucifer yellow (LY) was assessed using Transwell assays. The results revealed that post-ischemia administration of EGF (250 ng/ml) significantly attenuated the decrease in mRNA (P<0.05) and protein (P<0.01) expression levels of claudin-5 and ZO-1, and the increase in endothelial permeability of LY (P<0.05) induced by 4 h OGD exposure followed by 24 h reoxygenation. In addition, EGF did not significant affect cell viability. The current study suggested a potential of EGF to improve BBB integrity against ischemic injury by upregulating the expression of TJ proteins and reducing endothelial permeability.