Effect of alisol A on cerebral ischemia reperfusion injury by protecting blood brain barrier and its mechanism / 中国药理学通报

Aim To investigate whether alisol A (AA) could improve the blood brain barrier (BBB) mediated cortex cerebral ischemia-repeifusion injury (CIRI) by inhibiting matrix metalloproteinase 9 (MMP-9). Methods The global cerebral ischemia- reperfusion (GCI/R) model in mice was established, and the AA was intragastric injected subsequently for seven days. The modified neurological severity scores (mNSS), open field test and Y-maze test were applied to detect neurological function. Magnetic resonance spectroscopy (MRS) was used to detect relevant neu- rosubstance metabolism in cortex of mice. Transmission electron microscope (TEM) was employed to observe the ultrastructure of BBB in cortex. Western blot and immunohistochemistry were used to detect the MMP-9 level in cortex. The binding possibility of A A and MMP-9 was determined by molecular docking. Results Compared with Sham group, mice in GCI/R group have an increased mNSS score but decreased at total distance and center distance to total distance ratio in open field test as well as alternation rate in Y-maze test (P<0.01). While mice in GCI/R + AA group have a decreased mNSS score but increased at total distance and center distance to total distance ratio in open field test as well as alternation rate in Y-maze test (P<0.01) compared with GCI/R group. MRS results found that in cortex of GCI/R group mice, the level of GABA and NAA significantly decreased while the Cho, mI and Tau level increased (P<0.01). Whereas in GCI/R + AA group mice, the GABA and NAA level increased and the Cho, ml and Tau decreased significantly (P<0.01). By TEM we observed that the basilemma of cerebral microvessels collapsed, the lumen narrowed, the endothelial cells were active and plasma membranes ruffled, gaps between cells were enlarged and tight junctions were damaged and the end feet of astrocytes were swollen in GCI/R group mice. While in GCI/R + AA group mice, the lumen was filled, plasma membranes of endothelial cells were smooth, tight junctions were complete and end feet of astrocytes were in normal condition. Western blot and immunohistochemistry both found that the MMP-9 level increased in GCI/R group mice (P < 0.01) and decreased in GCI/R + AA group mice (P < 0.05). Molecular docking proved the binding between aliso A and MMP9 through TYR-50 and ARG-106, and the binding energy was calculated as -6.24 kcal · mol

Analysis of Inhibitory Effect of Berberine Compounds on Acetylcholinesterase and Blood-brain Barrier Permeability / 中国实验方剂学杂志

ObjectiveTo examine the inhibitory effects of berberine compounds， including columbamine， on acetylcholinesterase from the perspectives of drug-target binding affinity and kinetics and explore the blood-brain barrier （BBB） permeability of these compounds in different multi-component backgrounds. MethodThe median inhibitory concentration （IC50） of acetylcholinesterase by berberine compounds including columbamine was measured using the Ellman-modified spectrophotometric method. The binding kinetic parameters （Koff） of these compounds with acetylcholinesterase were determined using the enzyme activity recovery method. A qualitative analysis of the ability of these components to penetrate the BBB and arrive at the brain tissue in diverse multi-component backgrounds （including medicinal herbs and compound formulas） was conducted using ultra performance liquid chromatography-high resolution mass spectrometry （UPLC-HRMS）. ResultBerberine compounds， including columbamine， exhibited strong inhibition of acetylcholinesterase， with IC50 values in the nanomolar range. Moreover， they displayed better drug-target binding kinetics characteristics （with smaller Koff values） than the positive control of donepezil hydrochloride （P<0.01）， indicating a longer inhibition duration of acetylcholinesterase. Berberine components such as columbamine could penetrate the BBB to arrive at brain tissue in the form of a monomer， as well as in the multi-component backgrounds of Coptis and Phellodendri Chinensis Cortex medicinal extracts and the compound formula Huanglian Jiedutang. ConclusionThese berberine compounds such as columbamine exhibit a strong inhibitory effect on acetylcholinesterase and can arrive at brain tissue in multi-component backgrounds. In the level of pharmacological substance， this supports the clinical efficacy of compound Huanglian Jiedutang in improving Alzheimer's disease， providing data support for elucidating the pharmacological basis of compound Huanglian Jiedutang.

Research progress of biomimetic nano drug delivery system in nervous system disease / 药学学报

Brain delivery of drugs remains challenging due to the presence of the blood-brain barrier (BBB). With advances in nanotechnology and biotechnology, new possibilities for brain-targeted drug delivery have emerged. Biomimetic nano drug delivery systems with high brain-targeting and BBB-penetrating capabilities, along with good biocompatibility and safety, can enable 'invisible' drug delivery. In this review, five different types of biomimetic strategies are presented and their research progress in central nervous system disorders is reviewed. Finally, the challenges and future prospects for biomimetic nano drug delivery systems in intracerebral drug delivery are summarized.

Transdermal drug delivery technology for brain-targeted drug delivery / 药学学报

Intracerebral delivery of drugs for the treatment of central nervous system disorders is usually limited by the blood-brain barrier (BBB). Transdermal drug delivery systems (TDDS) have the advantage of improving patient compliance and avoiding first-pass effects compared to intravenous, oral and intranasal drug delivery, and are an emerging non-invasive drug delivery route that facilitates long-term drug delivery to patients. The discovery of direct subcutaneous targeting of lymphatic pathways to brain tissue has made TDDS a new brain-targeted drug delivery strategy. At the same time, the development of nano-delivery technology has further facilitated the application of TDDS for targeted drug delivery to the brain. This review summarizes the mechanism of transdermal drug delivery into the brain and the application of TDDS in the treatment of brain diseases, providing new ideas and methods for the treatment of central nervous system diseases.

Research Progress on Protective Effect and Mechanism of Salidroside on Cerebral Ischemia Injury： A Review / 中国实验方剂学杂志

Ischemic stroke is caused by a variety of factors caused by intracerebral artery stenosis or obstruction， can lead to cerebral ischemia， hypoxia， neuronal necrosis and neurological dysfunction and other pathological injuries， with high morbidity， high disability rate， high mortality characteristics. Cerebral ischemia-reperfusion injury is the main secondary injury， which can lead to permanent disability or even death in severe cases. With the development of traditional Chinese medicine（TCM） modernization， the extraction and application of active components of TCM have been paid more and more attention. Salidroside， as the main active component of Rhodirosea， a rare Chinese medicinal herb， has been proved to fight cerebral ischemia injury by inhibiting cell apoptosis， anti-oxidative stress， reducing inflammatory response， protecting blood-brain barrier， regulating autophagy， promoting nerve remodeling and synaptic regeneration in preclinical trials. However， due to its multi-pathway， multi-pathway and multi-target action characteristics， the specific mechanism of salidroside to improve cerebral ischemia injury has not been fully elucidated. By reviewing relevant literature in the past decade， the author reviewed the mechanism of action of salidroside in the treatment of ischemic brain injury， and summarized the recent progress of its pharmacokinetic studies and safety evaluation， in order to provide theoretical basis and new research ideas for the development and clinical application of the active ingredients of traditional Chinese medicine.

Functionalized exosome-loaded ginsenoside Rg1 for the treatment of ischemic stroke / 生物工程学报

The aim of this study was to investigate the therapeutic effects and potential mechanism of c(RGDyK) peptide modified mesenchymal stem cell exosomes loaded with ginsenoside Rg1 (G-Rg1) on ischemic stroke. Thread-tying method was used to establish SD rats transient middle cerebral occlusion model (tMCAO). The model rats were randomly divided into tMCAO group, Exo group, free G-Rg1 group, Exo-Rg1 group and cRGD-Exo-Rg1 group, and sham group was used as control. The infarct volume was measured by 2, 3, 5-triphenyltetrachloride (TTC) staining, the changes of neuron and endothelium were observed by immunofluorescence, and the expression of related proteins was detected by Western blotting. The results showed that cRGD-Exo-Rg1 up-regulated the expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factors (HIF-1α) by activating PI3K/AKT pathway, thus promoting angiogenesis and neurogenesis, effectively reducing the volume of cerebral infarction and improving neural function. In addition, the delivery of cRGD-Exo-Rg1 to ischemic brain tissue up-regulated the expression of occludin and claudin-5, and reduced the injury of blood-brain barrier. Taken together, cRGD-Exo-Rg1 was effective in the treatment of ischemic stroke by promoting angiogenesis and neurogenesis, which provided experimental evidence for the potential clinical benefits of other neuroprotective therapies.

Meridian Tropism and Compatibility of Chinese Medicine from Theory of Brain Sweat Pore / 中国实验方剂学杂志

Since LIU Hejian proposed the concept of sweat pore， the theory of sweat pore has experienced accelerated development. Especially with the advances in modern human anatomy and physiology， the microscopic anatomy of sweat pore begins to focus on the intercellular space， ion channels and other membranous space with channels， pores， doors， etc.， which exert the functions of exchanging fluid， information， and energy inside and outside blood vessels and discharging metabolic wastes so as to maintain the normal operation of organs. Therefore， sweat pore is the structural basis for the movement of Qi and the central link of Qi-fluid exchange in the body. The brain， as the house of original spirit， is in charge of the spirit of five Zang-organs. The brain sweat pore is pivotal for the circulation of Qi， blood， and fluid in the brain， and it is the structural basis for the normal physiological functions of the brain. The dysfunction of the brain sweat pore will cause the stagnation of Qi and the abnormal transport of blood and fluid. It will cause the abnormal exchange of Qi， liquid and other material and information， which fail to nourish the original spirt and cause the loss of vital activity， eventually leading to consciousness and emotion disorders. The treatment should focus on opening the brain sweat pore， smoothing the exchange of Qi and fluid inside and outside the pore， and restoring the Qi movement， so as to cure encephalopathy. At present， western medicine treatment of encephalopathy needs to solve the problem of drug efflux from the blood-brain barrier and improve the effective concentration of drugs into the brain. The structure and function of brain sweat pore is similar to those of the blood-brain barrier. The aromatic resuscitative medicines and wind-extinguishing medicines can open the brain sweat pore. When being combined with other medicines， they can lead the medicine to enter the brain to restore the Qi movement of the brain sweat pore and enhance the therapeutic effect. Liver-pacifying wind-extinguishing medicines， insect medicines， tonifying medicines， heat-clearing toxin-removing medicines， and damp-draining medicines can treat pathological factors such as wind， phlegm， stasis， deficiency， toxin， and dampness， respectively. These medicines， combined with the medicines with the tropism to brain meridians， can open the brain sweat pore and guide the medicine into the brain to enhance the effective concentration of the medicine， thereby enhancing the efficacy against encephalopathy.

Advances in preclinical studies on borneol as an adjuvant for glioma / 药学实践杂志

Glioma is a common primary malignant brain tumor. At present, the main clinical treatment is surgical resection combined with radiotherapy and chemotherapy. Due to the selective permeability of the blood-brain barrier and the characteristics of multi-drug resistance of tumor cells, the therapeutic effect is not ideal. In recent years, studies have found that borneol could open the blood-brain barrier and promote the infiltration of chemotherapy drugs. When borneol is combined with or co-carried with chemotherapy drugs, chemotherapy drugs could target more glioma tissues and increase efficacy. The preclinical studies on the combination of borneol and chemotherapy drugs in recent years were reviewed in this article, in order to provide useful reference for the treatment of glioma.

Salmonella-mediated blood‒brain barrier penetration, tumor homing and tumor microenvironment regulation for enhanced chemo/bacterial glioma therapy

Chemotherapy is an important adjuvant treatment of glioma, while the efficacy is far from satisfactory, due not only to the biological barriers of blood‒brain barrier (BBB) and blood‒tumor barrier (BTB) but also to the intrinsic resistance of glioma cells via multiple survival mechanisms such as up-regulation of P-glycoprotein (P-gp). To address these limitations, we report a bacteria-based drug delivery strategy for BBB/BTB transportation, glioma targeting, and chemo-sensitization. Bacteria selectively colonized into hypoxic tumor region and modulated tumor microenvironment, including macrophages repolarization and neutrophils infiltration. Specifically, tumor migration of neutrophils was employed as hitchhiking delivery of doxorubicin (DOX)-loaded bacterial outer membrane vesicles (OMVs/DOX). By virtue of the surface pathogen-associated molecular patterns derived from native bacteria, OMVs/DOX could be selectively recognized by neutrophils, thus facilitating glioma targeted delivery of drug with significantly enhanced tumor accumulation by 18-fold as compared to the classical passive targeting effect. Moreover, the P-gp expression on tumor cells was silenced by bacteria type III secretion effector to sensitize the efficacy of DOX, resulting in complete tumor eradication with 100% survival of all treated mice. In addition, the colonized bacteria were finally cleared by anti-bacterial activity of DOX to minimize the potential infection risk, and cardiotoxicity of DOX was also avoided, achieving excellent compatibility. This work provides an efficient trans-BBB/BTB drug delivery strategy via cell hitchhiking for enhanced glioma therapy.

Stigmasterol protects human brain microvessel endothelial cells against ischemia-reperfusion injury through suppressing EPHA2 phosphorylation / 中国天然药物

Stigmasterol is a plant sterol with anti-apoptotic, anti-oxidative and anti-inflammatory effect through multiple mechanisms. In this study, we further assessed whether it exerts protective effect on human brain microvessel endothelial cells (HBMECs) against ischemia-reperfusion injury and explored the underlying mechanisms. HBMECs were used to establish an in vitro oxygen and glucose deprivation/reperfusion (OGD/R) model, while a middle cerebral artery occlusion (MCAO) model of rats were constructed. The interaction between stigmasterol and EPHA2 was detected by surface plasmon resonance (SPR) and cellular thermal shift assay (CETSA). The results showed that 10 μmol·L-1 stigmasterol significantly protected cell viability, alleviated the loss of tight junction proteins and attenuated the blood-brain barrier (BBB) damage induced by OGD/R in thein vitro model. Subsequent molecular docking showed that stigmasterol might interact with EPHA2 at multiple sites, including T692, a critical gatekeep residue of this receptor. Exogenous ephrin-A1 (an EPHA2 ligand) exacerbated OGD/R-induced EPHA2 phosphorylation at S897, facilitated ZO-1/claudin-5 loss, and promoted BBB leakage in vitro, which were significantly attenuated after stigmasterol treatment. The rat MCAO model confirmed these protective effects in vivo. In summary, these findings suggest that stigmasterol protects HBMECs against ischemia-reperfusion injury by maintaining cell viability, reducing the loss of tight junction proteins, and attenuating the BBB damage. These protective effects are at least meditated by its interaction with EPHA2 and inhibitory effect on EPHA2 phosphorylation.

Updated Understanding of the Glial-Vascular Unit in Central Nervous System Disorders / 神经科学通报·英文版

The concept of the glial-vascular unit (GVU) was raised recently to emphasize the close associations between brain cells and cerebral vessels, and their coordinated reactions to diverse neurological insults from a "glio-centric" view. GVU is a multicellular structure composed of glial cells, perivascular cells, and perivascular space. Each component is closely linked, collectively forming the GVU. The central roles of glial and perivascular cells and their multi-level interconnections in the GVU under normal conditions and in central nervous system (CNS) disorders have not been elucidated in detail. Here, we comprehensively review the intensive interactions between glial cells and perivascular cells in the niche of perivascular space, which take part in the modulation of cerebral blood flow and angiogenesis, formation of the blood-brain barrier, and clearance of neurotoxic wastes. Next, we discuss dysfunctions of the GVU in various neurological diseases, including ischemic stroke, spinal cord injury, Alzheimer's disease, and major depression disorder. In addition, we highlight the possible therapies targeting the GVU, which may have potential clinical applications.

Parkinson's Disease: A Multisystem Disorder / 神经科学通报·英文版

The way sporadic Parkinson's disease (PD) is perceived has undergone drastic changes in recent decades. For a long time, PD was considered a brain disease characterized by motor disturbances; however, the identification of several risk factors and the hypothesis that PD has a gastrointestinal onset have shed additional light. Today, after recognition of prodromal non-motor symptoms and the pathological processes driving their evolution, there is a greater understanding of the involvement of other organ systems. For this reason, PD is increasingly seen as a multiorgan and multisystemic pathology that arises from the interaction of susceptible genetic factors with a challenging environment during aging-related decline.

Soybean isoflavones alleviate cerebral ischemia/reperfusion injury in rats by inhibiting ferroptosis and inflammatory cascade reaction / 南方医科大学学报

OBJECTIVE@#To explore the mechanism that mediates the effect of soybean isoflavones (SI) against cerebral ischemia/reperfusion (I/R) injury in light of the regulation of regional cerebral blood flow (rCBF), ferroptosis, inflammatory response and blood-brain barrier (BBB) permeability.@*METHODS@#A total of 120 male SD rats were equally randomized into sham-operated group (Sham group), cerebral I/R injury group and SI pretreatment group (SI group). Focal cerebral I/R injury was induced in the latter two groups using a modified monofilament occlusion technique, and the intraoperative changes of real-time cerebral cortex blood flow were monitored using a laser Doppler flowmeter (LDF). The postoperative changes of cerebral pathological morphology and the ultrastructure of the neurons and the BBB were observed with optical and transmission electron microscopy. The neurological deficits of the rats was assessed, and the severities of cerebral infarction, brain edema and BBB disruption were quantified. The contents of Fe2+, GSH, MDA and MPO in the ischemic penumbra were determined with spectrophotometric tests. Serum levels of TNF-α and IL-1βwere analyzed using ELISA, and the expressions of GPX4, MMP-9 and occludin around the lesion were detected with Western blotting and immunohistochemistry.@*RESULTS@#The rCBF was sharply reduced in the rats in I/R group and SI group after successful insertion of the monofilament. Compared with those in Sham group, the rats in I/R group showed significantly increased neurological deficit scores, cerebral infarction volume, brain water content and Evans blue permeability (P < 0.01), decreased Fe2+ level, increased MDA level, decreased GSH content and GPX4 expression (P < 0.01), increased MPO content and serum levels of TNF-α and IL-1β (P < 0.01), increased MMP-9 expression and lowered occludin expression (P < 0.01). All these changes were significantly ameliorated in rats pretreated with IS prior to I/R injury (P < 0.05 or 0.01).@*CONCLUSION@#SI preconditioning reduces cerebral I/R injury in rats possibly by improving rCBF, inhibiting ferroptosis and inflammatory response and protecting the BBB.

Progress on Prevention and Treatment of Cerebral Small Vascular Disease Using Integrative Medicine / 中国结合医学杂志

Cerebral small vessel disease (CSVD) is a senile brain lesion caused by the abnormal structure and function of arterioles, venules and capillaries in the aging brain. The etiology of CSVD is complex, and disease is often asymptomatic in its early stages. However, as CSVD develops, brain disorders may occur, such as stroke, cognitive dysfunction, dyskinesia and mood disorders, and heart, kidney, eye and systemic disorders. As the population continues to age, the burden of CSVD is increasing. Moreover, there is an urgent need for better screening methods and diagnostic markers for CSVD, in addition to preventive and asymptomatic- and mild-stage treatments. Integrative medicine (IM), which combines the holistic concepts and syndrome differentiations of Chinese medicine with modern medical perspectives, has unique advantages for the prevention and treatment of CSVD. In this review, we summarize the biological markers, ultrasound and imaging features, disease-related genes and risk factors relevant to CSVD diagnosis and screening. Furthermore, we discuss IM-based CSVD prevention and treatment strategies to stimulate further research in this field.

Research advances in brain lactate level and hepatic encephalopathy / 临床肝胆病杂志

Hepatic encephalopathy (HE) is a common complication and an independent risk factor for death in patients with liver cirrhosis. Brain lactate level is associated with the progression and severity of HE, and research on brain lactate level may help to further explain the pathogenesis of HE. This article summarizes the metabolic process of brain lactate, the association between brain lactate level and HE, and the potential therapeutic targets for HE and provides a reference for clinicians to further systematically evaluate the progression, treatment outcome, and prognosis of patients with HE, in order to reduce the medical burden of patients and improve the prognosis of patients with HE.

Effect of Angelica dahurica coumarins on the transport behavior of puerarin across blood-brain barrier in vitro and in vivo / 药学学报

A BBB co-culture cell model consisting of rat brain microvascular endothelial cells (BMEC) and astrocytes (AS) was established to study the effect of Angelica dahurica coumarins on the transport behavior of puerarin across blood-brain barrier (BBB) in vitro and in vivo. The barrier function of this model was evaluated by measuring the transendothelial resistance, phenol red permeability and BBB related protein expression. The permeability assay and western blot methods were performed to study the effects of Angelica dahurica coumarins on the BBB permeability and the expression of BBB related protein. The animal experiment protocols in this study were approved by the Animal Ethics Committee of Xi'an Jiaotong University (Animal Ethics No.: 2021-1329). The results showed that the established BMEC/AS co-culture model could be used to evaluate drug transport across BBB in vitro. After combined with Angelica dahurica coumarins, the transport capacity of puerarin was significantly increased in vitro and in vivo. Additionally, Angelica dahurica coumarins enhanced BBB permeability and inhibited the protein expression of P-glycoprotein (P-gp), zonula occludens-1 (ZO-1) and occludin. Angelica dahurica coumarins might increase BBB permeability by inhibiting the expression of P-gp and tight junction protein, thereby increasing the content of puerarin in brain tissue.

The modulation and mechanisms of high-altitude hypoxia in drug transport across the blood-brain barrier / 药学学报

The function of the central nervous system was significantly altered under high-altitude hypoxia, and these changes lead to central nervous system disease and affected the metabolism of drugs in vivo. The blood-brain barrier is essential for maintaining central nervous system stability and plays a key role in the regulation of drug metabolism, and barrier structure and dysfunction affect drug transport to the brain. Changes in the structure and function of the blood-brain barrier and the transport of drugs across the blood-brain barrier under high-altitude hypoxia are regulated by changes in brain microvascular endothelial cells, astrocytes and pericytes, and are regulated by drug metabolism factors such as drug transporters and drug metabolizing enzymes. This article reviews the effects of high-altitude hypoxia on the structure and function of the blood-brain barrier and the effects of changes in the blood-brain barrier on drug metabolism. We investigate the regulatory effects and underlying mechanisms of the blood-brain barrier and related pathways such as transcription factors, inflammatory factors and nuclear receptors on drug transport under high-altitude hypoxia.

Resampling combined with stacking learning for prediction of blood-brain barrier permeability of compounds / 生物医学工程学杂志

It is a significant challenge to improve the blood-brain barrier (BBB) permeability of central nervous system (CNS) drugs in their development. Compared with traditional pharmacokinetic property tests, machine learning techniques have been proven to effectively and cost-effectively predict the BBB permeability of CNS drugs. In this study, we introduce a high-performance BBB permeability prediction model named balanced-stacking-learning based BBB permeability predictor(BSL-B3PP). Firstly, we screen out the feature set that has a strong influence on BBB permeability from the perspective of medicinal chemistry background and machine learning respectively, and summarize the BBB positive(BBB+) quantification intervals. Then, a combination of resampling algorithms and stacking learning(SL) algorithm is used for predicting the BBB permeability of CNS drugs. The BSL-B3PP model is constructed based on a large-scale BBB database (B3DB). Experimental validation shows an area under curve (AUC) of 97.8% and a Matthews correlation coefficient (MCC) of 85.5%. This model demonstrates promising BBB permeability prediction capability, particularly for drugs that cannot penetrate the BBB, which helps reduce CNS drug development costs and accelerate the CNS drug development process.

Polymeric nanocarriers for nose-to-brain drug delivery in neurodegenerative diseases and neurodevelopmental disorders

Neurodegenerative diseases are progressive conditions that affect the neurons of the central nervous system (CNS) and result in their damage and death. Neurodevelopmental disorders include intellectual disability, autism spectrum disorder, and attention-deficit/hyperactivity disorder and stem from the disruption of essential neurodevelopmental processes. The treatment of neurodegenerative and neurodevelopmental conditions, together affecting ∼120 million people worldwide, is challenged by the blood-brain barrier (BBB) and the blood-cerebrospinal fluid barrier that prevent the crossing of drugs from the systemic circulation into the CNS. The nose-to-brain pathway that bypasses the BBB and increases the brain bioavailability of intranasally administered drugs is promising to improve the treatment of CNS conditions. This pathway is more efficient for nanoparticles than for solutions, hence, the research on intranasal nano-drug delivery systems has grown exponentially over the last decade. Polymeric nanoparticles have become key players in the field owing to the high design and synthetic flexibility. This review describes the challenges faced for the treatment of neurodegenerative and neurodevelopmental conditions, the molecular and cellular features of the nasal mucosa and the contribution of intranasal nano-drug delivery to overcome them. Then, a comprehensive overview of polymeric nanocarriers investigated to increase drug bioavailability in the brain is introduced.

Endogenous FGF21 attenuates blood-brain barrier disruption in penumbra after delayed recanalization in MCAO rats through FGFR1/PI3K/Akt pathway / 中南大学学报(医学版)

OBJECTIVES@#Restoration of blood circulation within "time window" is the principal treating goal for treating acute ischemic stroke. Previous studies revealed that delayed recanalization might cause serious ischemia/reperfusion injury. However, plenty of evidences showed delayed recanalization improved neurological outcomes in acute ischemic stroke. This study aims to explore the role of delayed recanalization on blood-brain barrier (BBB) in the penumbra (surrounding ischemic core) and neurological outcomes after middle cerebral artery occlusion (MCAO).@*METHODS@#Recanalization was performed on the 3rd day after MCAO. BBB disruption was tested by Western blotting, Evans blue dye, and immunofluorescence staining. Infarct volume and neurological outcomes were evaluated on the 7th day after MCAO. The expression of fibroblast growth factor 21 (FGF21), fibroblast growth factor receptor 1 (FGFR1), phosphatidylinositol-3-kinase (PI3K), and serine/threonine kinase (Akt) in the penumbra were observed by immunofluorescence staining and/or Western blotting.@*RESULTS@#The extraversion of Evans blue, IgG, and albumin increased surrounding ischemic core after MCAO, but significantly decreased after recanalization. The expression of Claudin-5, Occludin, and zona occludens 1 (ZO-1) decreased surrounding ischemic core after MCAO, but significantly increased after recanalization. Infarct volume reduced and neurological outcomes improved following recanalization (on the 7th day after MCAO). The expressions of Claudin-5, Occludin, and ZO-1 decreased surrounding ischemic core following MCAO, which were up-regulated corresponding to the increases of FGF21, p-FGFR1, PI3K, and p-Akt after recanalization. Intra-cerebroventricular injection of FGFR1 inhibitor SU5402 down-regulated the expression of PI3K, p-Akt, Occludin, Claudin-5, and ZO-1 in the penumbra, which weakened the beneficial effects of recanalization on neurological outcomes after MCAO.@*CONCLUSIONS@#Delayed recanalization on the 3rd day after MCAO increases endogenous FGF21 in the penumbra and activates FGFR1/PI3K/Akt pathway, which attenuates BBB disruption in the penumbra and improves neurobehavior in MCAO rats.