Due to the ability of the blood–brain barrier(BBB) to prevent the entry of drugs into the brain, it is a challenge to treat central nervous system disorders pharmacologically. The development of nanotechnology provid...Due to the ability of the blood–brain barrier(BBB) to prevent the entry of drugs into the brain, it is a challenge to treat central nervous system disorders pharmacologically. The development of nanotechnology provides potential to overcome this problem. In this review, the barriers to brain-targeted drug delivery are reviewed, including the BBB, blood–brain tumor barrier(BBTB), and nose-to-brain barrier. Delivery strategies are focused on overcoming the BBB, directly targeting diseased cells in the brain, and dual-targeted delivery. The major concerns and perspectives on constructing brain-targeted delivery systems are discussed.展开更多
The blood–brain barrier(BBB) and the poor ability of many drugs to cross that barrier greatly limits the efficacy of chemotherapies for glioblastoma multiforme(GBM). The present study exploits albumin as drug deliver...The blood–brain barrier(BBB) and the poor ability of many drugs to cross that barrier greatly limits the efficacy of chemotherapies for glioblastoma multiforme(GBM). The present study exploits albumin as drug delivery vehicle to promote the chemotherapeutic efficacy of paclitaxel(PTX) by improving the stability and targeting efficiency of PTX/albumin nanoparticles(NPs). Here we characterize PTX-loaded human serum albumin(HSA) NPs stabilized with intramolecular disulfide bonds and modified with substance P(SP) peptide as the targeting ligand. The fabricated SP-HSA-PTX NPs exhibited satisfactory drug-loading content(7.89%) and entrapment efficiency(85.7%) with a spherical structure(about 150 nm) and zeta potential of -12.0 mV. The in vitro drug release from SP-HSA-PTX NPs occurred in a redox-responsive manner. Due to the targeting effect of the SP peptide, cellular uptake of SP-HSA-PTX NPs into brain capillary endothelial cells(BCECs) and U87 cells was greatly improved.The low IC_(50), prolonged survival period and the obvious pro-apoptotic effect shown by TUNEL analysis all demonstrated that the fabricated SP-HSA-PTX NPs showed a satisfactory anti-tumor effect and could serve as a novel strategy for GBM treatment.展开更多
Chemotherapy outcomes for the treatment of glioma remains unsatisfactory due to the inefficient drug transport across the blood–brain barrier(BBB) and insufficient drug accumulation in the tumor region. Although many...Chemotherapy outcomes for the treatment of glioma remains unsatisfactory due to the inefficient drug transport across the blood–brain barrier(BBB) and insufficient drug accumulation in the tumor region. Although many approaches, including various nanosystems, have been developed to promote the distribution of chemotherapeutics in the brain tumor, the delivery efficiency and the possible damage to the normal brain function still greatly restrict the clinical application of the nanocarriers.Therefore, it is urgent and necessary to discover more safe and effective BBB penetration and gliomatargeting strategies. In the present study, menthol, one of the strongest BBB penetration enhancers screened from traditional Chinese medicine, was conjugated to casein, a natural food protein with brain targeting capability. Then the conjugate self-assembled into the nanoparticles to load anti-cancer drugs.The nanoparticles were characterized to have appropriate size, spheroid shape and high loading drug capacity. Tumor spheroid penetration experiments demonstrated that penetration ability of mentholmodified casein nanoparticles(M-CA-NP) into the tumor were much deeper than that of unmodified nanoparticles. In vivo imaging further verified that M-CA-NPs exhibited higher brain tumor distribution than unmodified nanoparticles. The median survival time of glioma-bearing mice treated with HCPT-MCA-NPs was significantly prolonged than those treated with free HCPT or HCPT-CA-NPs. HE staining ofthe organs indicated the safety of the nanoparticles. Therefore, the study combined the advantages of traditional Chinese medicine strategy with modern delivery technology for brain targeting, and provide a safe and effective approach for glioma therapy.展开更多
Brain tumor incidence shows an upward trend in recent years; brain tumors account for 5% of adult tumors, while in children, this figure has increased to 70%. Moreover, 20%–30% of malignant tumors will eventually met...Brain tumor incidence shows an upward trend in recent years; brain tumors account for 5% of adult tumors, while in children, this figure has increased to 70%. Moreover, 20%–30% of malignant tumors will eventually metastasize into the brain. Both benign and malignant tumors can cause an increase in intracranial pressure and brain tissue compression, leading to central nervous system(CNS) damage which endangers the patients' lives. Despite the many approaches to treating brain tumors and the progress that has been made, only modest gains in survival time of brain tumor patients have been achieved. At present, chemotherapy is the treatment of choice for many cancers, but the special structure of the blood–brain barrier(BBB) limits most chemotherapeutic agents from passing through the BBB and penetrating into tumors in the brain. The BBB microenvironment contains numerous cell types, including endothelial cells, astrocytes, peripheral cells and microglia, and extracellular matrix(ECM). Many chemical components of natural products are reported to regulate the BBB microenvironment near brain tumors and assist in their treatment. This review focuses on the composition and function of the BBB microenvironment under both physiological and pathological conditions, and the current research progress in regulating the BBB microenvironment by natural products to promote the treatment of brain tumors.展开更多
Major depressive disorder (MDD) is the most common nonfatal disease burden world-wide. Systemic chronic low-grade inflammation has been reported to be associated with MDD pro-gression by affecting monoaminergic and gl...Major depressive disorder (MDD) is the most common nonfatal disease burden world-wide. Systemic chronic low-grade inflammation has been reported to be associated with MDD pro-gression by affecting monoaminergic and glutamatergic neurotransmission. However,whether various proinflammatory cytokines are abnormally elevated before the first episode of depression is still largely unclear. Here,we evaluated 184 adolescent patients who were experiencing their first episode of depressive disorder,and the same number of healthy individuals was included as con-trols. We tested the serum levels of high-sensitivity C-reactive protein (hs-CRP),tumor necrosis factor-α(TNF-α),IgE,14 different types of food antigen-specific IgG,histamine,homocysteine,S100 calcium-binding protein B,and diamine oxidase. We were not able to find any significant dif-ferences in the serum levels of hs-CRP or TNF-αbetween the two groups. However,the histamine level of the patients (12.35μM) was significantly higher than that of the controls (9.73μM,P<0.001,Mann–Whitney U test). Moreover,significantly higher serum food antigen-specific IgG positive rates were also found in the patient group. Furthermore,over 80% of patients exhibited prolonged food intolerance with elevated levels of serum histamine,leading to hyperpermeability of the blood–brain barrier,which has previously been implicated in the pathogen-esis of MDD. Hence,prolonged high levels of serum histamine could be a risk factor for depressive disorders,and antihistamine release might represent a novel therapeutic strategy for depression treatment.展开更多
Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells...Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells in the central nervous system,maintain homeostasis in the neural environment,support neurons,mediate apoptosis,participate in immune regulation,and have neuroprotective effects.Increasing evidence has shown that microglia play a pivotal role in the pathogenesis of subarachnoid hemorrhage and affect the process of injury and the prognosis of subarachnoid hemorrhage.Moreover,microglia play certain neuroprotective roles in the recovery phase of subarachnoid hemorrhage.Several approaches aimed at modulating microglia function are believed to attenuate subarachnoid hemorrhage injury.This provides new targets and ideas for the treatment of subarachnoid hemorrhage.However,an in-depth and comprehensive summary of the role of microglia after subarachnoid hemorrhage is still lacking.This review describes the activation of microglia after subarachnoid hemorrhage and their roles in the pathological processes of vasospasm,neuroinflammation,neuronal apoptosis,blood–brain barrier disruption,cerebral edema,and cerebral white matter lesions.It also discusses the neuroprotective roles of microglia during recovery from subarachnoid hemorrhage and therapeutic advances aimed at modulating microglial function after subarachnoid hemorrhage.Currently,microglia in subarachnoid hemorrhage are targeted with TLR inhibitors,nuclear factor-κB and STAT3 pathway inhibitors,glycine/tyrosine kinases,NLRP3 signaling pathway inhibitors,Gasdermin D inhibitors,vincristine receptorαreceptor agonists,ferroptosis inhibitors,genetic modification techniques,stem cell therapies,and traditional Chinese medicine.However,most of these are still being evaluated at the laboratory stage.More clinical studies and data on subarachnoid hemorrhage are required to improve the treatment of subarachnoid hemorrhage.展开更多
Tanycytes, specialized ependymal cells located in the hypothalamus, play a crucial role in the generation of new neurons that contribute to the neural circuits responsible for regulating the systemic energy balance. T...Tanycytes, specialized ependymal cells located in the hypothalamus, play a crucial role in the generation of new neurons that contribute to the neural circuits responsible for regulating the systemic energy balance. The precise coordination of the gene networks controlling neurogenesis in naive and mature tanycytes is essential for maintaining homeostasis in adulthood. However, our understanding of the molecular mechanisms and signaling pathways that govern the proliferation and differentiation of tanycytes into neurons remains limited. This article aims to review the recent advancements in research into the mechanisms and functions of tanycyte-derived neurogenesis. Studies employing lineage-tracing techniques have revealed that the neurogenesis specifically originating from tanycytes in the hypothalamus has a compensatory role in neuronal loss and helps maintain energy homeostasis during metabolic diseases. Intriguingly,metabolic disorders are considered early biomarkers of Alzheimer's disease. Furthermore,the neurogenic potential of tanycytes and the state of newborn neurons derived from tanycytes heavily depend on the maintenance of mild microenvironments, which may be disrupted in Alzheimer's disease due to the impaired blood–brain barrier function.However, the specific alterations and regulatory mechanisms governing tanycyte-derived neurogenesis in Alzheimer's disease remain unclear. Accumulating evidence suggests that tanycyte-derived neurogenesis might be impaired in Alzheimer's disease, exacerbating neurodegeneration. Confirming this hypothesis, however, poses a challenge because of the lack of long-term tracing and nucleus-specific analyses of newborn neurons in the hypothalamus of patients with Alzheimer's disease. Further research into the molecular mechanisms underlying tanycyte-derived neurogenesis holds promise for identifying small molecules capable of restoring tanycyte proliferation in neurodegenerative diseases. This line of investigation could provide valuable insights into potential therapeu展开更多
Intranasal drug administration is receiving increased attention as a delivery method for by-passing the blood–brain barrier and rapidly targeting therapeutics to the CNS.However,rapid mucociliary clearance in the nas...Intranasal drug administration is receiving increased attention as a delivery method for by-passing the blood–brain barrier and rapidly targeting therapeutics to the CNS.However,rapid mucociliary clearance in the nasal cavity is a major hurdle.The purpose of this study was to evaluate the effect of mucoadhesive polymers in enhancing the delivery of nimodipine microemulsion to the brain via the intranasal route.The optimized mucoadhesive microemulsion was characterized,and the in vitro drug release and in vivo nasal absorption of drug from the new formulation were evaluated in rats.The optimized formulation consisted of Capmul MCM as oil,Labrasol as surfactant,and Transcutol P as co-surfactant,with a particle size of 250 nm and zeta potential value of?15 mV.In vitro and ex vivo permeation studies showed an initial burst of drug release at 30 min and sustained release up to 6 h,attributable to the presence of free drug entrapped in the mucoadhesive layer.In vivo pharmacokinetic studies in rats showed that the use of the mucoadhesive microemulsion enhanced brain and plasma concentrations of nimodipine.These results suggest that incorporation of a mucoadhesive agent in a microemulsion intranasal delivery system can increase the retention time of the formulation and enhance brain delivery of drugs.展开更多
Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple rol...Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple roles of mononuclear macrophages in the neuroinflammatory process. Monocytes play a significant role in neuroinflammation, and managing neuroinflammation by manipulating peripheral monocytes stands out as an effective strategy for the treatment of multiple sclerosis, leading to improved patient outcomes. This review outlines the steps involved in the entry of myeloid monocytes into the central nervous system that are targets for effective intervention: the activation of bone marrow hematopoiesis, migration of monocytes in the blood, and penetration of the blood–brain barrier by monocytes. Finally, we summarize the different monocyte subpopulations and their effects on the central nervous system based on phenotypic differences. As activated microglia resemble monocyte-derived macrophages, it is important to accurately identify the role of monocyte-derived macrophages in disease. Depending on the roles played by monocyte-derived macrophages at different stages of the disease, several of these processes can be interrupted to limit neuroinflammation and improve patient prognosis. Here, we discuss possible strategies to target monocytes in neurological diseases, focusing on three key aspects of monocyte infiltration into the central nervous system, to provide new ideas for the treatment of neurodegenerative diseases.展开更多
Current therapeutic strategies for ischemic stroke fall short of the desired objective of neurological functional recovery.Therefore,there is an urgent need to develop new methods for the treatment of this condition.E...Current therapeutic strategies for ischemic stroke fall short of the desired objective of neurological functional recovery.Therefore,there is an urgent need to develop new methods for the treatment of this condition.Exosomes are natural cell-derived vesicles that mediate signal transduction between cells under physiological and pathological conditions.They have low immunogenicity,good stability,high delivery efficiency,and the ability to cross the blood–brain barrier.These physiological properties of exosomes have the potential to lead to new breakthroughs in the treatment of ischemic stroke.The rapid development of nanotechnology has advanced the application of engineered exosomes,which can effectively improve targeting ability,enhance therapeutic efficacy,and minimize the dosages needed.Advances in technology have also driven clinical translational research on exosomes.In this review,we describe the therapeutic effects of exosomes and their positive roles in current treatment strategies for ischemic stroke,including their antiinflammation,anti-apoptosis,autophagy-regulation,angiogenesis,neurogenesis,and glial scar formation reduction effects.However,it is worth noting that,despite their significant therapeutic potential,there remains a dearth of standardized characterization methods and efficient isolation techniques capable of producing highly purified exosomes.Future optimization strategies should prioritize the exploration of suitable isolation techniques and the establishment of unified workflows to effectively harness exosomes for diagnostic or therapeutic applications in ischemic stroke.Ultimately,our review aims to summarize our understanding of exosome-based treatment prospects in ischemic stroke and foster innovative ideas for the development of exosome-based therapies.展开更多
Acute ischemic stroke is a clinical emergency and a condition with high morbidity,mortality,and disability.Accurate predictive,diagnostic,and prognostic biomarkers and effective therapeutic targets for acute ischemic ...Acute ischemic stroke is a clinical emergency and a condition with high morbidity,mortality,and disability.Accurate predictive,diagnostic,and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain undetermined.With innovations in high-throughput gene sequencing analysis,many aberrantly expressed non-coding RNAs(ncRNAs)in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental models.Differentially expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes,leading to neuroprotection or deterioration,thus ncRNAs can serve as therapeutic targets in acute ischemic stroke.Moreover,distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.In particular,ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic stroke.In this review,we consolidate the latest progress of research into the roles of ncRNAs(microRNAs,long ncRNAs,and circular RNAs)in the pathological processes of acute ischemic stroke–induced brain damage,as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.Findings from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.展开更多
Glioblastoma multiforme(GBM) is the most common primary malignant brain tumor, and it is associated with poor prognosis. Its characteristics of being highly invasive and undergoing heterogeneous genetic mutation, as w...Glioblastoma multiforme(GBM) is the most common primary malignant brain tumor, and it is associated with poor prognosis. Its characteristics of being highly invasive and undergoing heterogeneous genetic mutation, as well as the presence of the blood–brain barrier(BBB), have reduced the efficacy of GBM treatment. The emergence of a novel therapeutic method, namely, sonodynamic therapy(SDT), provides a promising strategy for eradicating tumors via activated sonosensitizers coupled with low-intensity ultrasound. SDT can provide tumor killing effects for deep-seated tumors, such as brain tumors. However, conventional sonosensitizers cannot effectively reach the tumor region and kill additional tumor cells, especially brain tumor cells. Efforts should be made to develop a method to help therapeutic agents pass through the BBB and accumulate in brain tumors. With the development of novel multifunctional nanosensitizers and newly emerging combination strategies, the killing ability and selectivity of SDT have greatly improved and are accompanied with fewer side effects. In this review, we systematically summarize the findings of previous studies on SDT for GBM, with a focus on recent developments and promising directions for future research.展开更多
The blood–brain barrier constitutes a dynamic and interactive boundary separating the central nervous system and the peripheral circulation.It tightly modulates the ion transport and nutrient influx,while restricting...The blood–brain barrier constitutes a dynamic and interactive boundary separating the central nervous system and the peripheral circulation.It tightly modulates the ion transport and nutrient influx,while restricting the entry of harmful factors,and selectively limiting the migration of immune cells,thereby maintaining brain homeostasis.Despite the well-established association between blood–brain barrier disruption and most neurodegenerative/neuroinflammatory diseases,much remains unknown about the factors influencing its physiology and the mechanisms underlying its breakdown.Moreover,the role of blood–brain barrier breakdown in the translational failure underlying therapies for brain disorders is just starting to be understood.This review aims to revisit this concept of“blood–brain barrier breakdown,”delving into the most controversial aspects,prevalent challenges,and knowledge gaps concerning the lack of blood–brain barrier integrity.By moving beyond the oversimplistic dichotomy of an“open”/“bad”or a“closed”/“good”barrier,our objective is to provide a more comprehensive insight into blood–brain barrier dynamics,to identify novel targets and/or therapeutic approaches aimed at mitigating blood–brain barrier dysfunction.Furthermore,in this review,we advocate for considering the diverse time-and location-dependent alterations in the blood–brain barrier,which go beyond tight-junction disruption or brain endothelial cell breakdown,illustrated through the dynamics of ischemic stroke as a case study.Through this exploration,we seek to underscore the complexity of blood–brain barrier dysfunction and its implications for the pathogenesis and therapy of brain diseases.展开更多
Brain delivery of macromolecular therapeutics (e.g., proteins) remains an unsolved problem because of the formidable blood brain bather (BBB). Although a direct pathway of nose-to-brain transfer provides an answer to ...Brain delivery of macromolecular therapeutics (e.g., proteins) remains an unsolved problem because of the formidable blood brain bather (BBB). Although a direct pathway of nose-to-brain transfer provides an answer to circumventing the BBB and has already been intensively investigated for brain delivery of small drugs, new challenges arise for intranasal delivery of proteins because of their larger size and hydrophilicity. h order to overcome the bathers and take advantage of available pathways (e.g., epithelial tight junctions, uptake by olfactory neurons, transport into brain tissues, and intra-brain diffusion), a low molecular weight protamine (LMWP) cell-penetrating peptide was utilized to facilitate nose-to-brain transport. Cell-penetrating peptides (CPP) have been widely used to mediate macromolecular delivery through many kinds of biobarriers. Our results show that conjugates of LMWP proteinsare able to effectively penetrate into the brain after intranasal administration. The CPP-based intranasal method highlights a promising solution for protein therapy of brain diseases. (C) 2016 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.展开更多
The central nervous system(CNS)is a reservoir of immune privilege.Specialized immune glial cells are responsible for maintenance and defense against foreign invaders.The blood–brain barrier(BBB)prevents detrimental p...The central nervous system(CNS)is a reservoir of immune privilege.Specialized immune glial cells are responsible for maintenance and defense against foreign invaders.The blood–brain barrier(BBB)prevents detrimental pathogens and potentially overreactive immune cells from entering the periphery.When the double-edged neuroinflammatory response is overloaded,it no longer has the protective function of promoting neuroregeneration.Notably,microbiota and its derivatives may emerge as pathogen-associated molecular patterns of brain pathology,causing microbiome–gut–brain axis dysregulation from the bottom-up.When dysbiosis of the gastrointestinal flora leads to subsequent alterations in BBB permeability,peripheral immune cells are recruited to the brain.This results in amplification of neuroinflammatory circuits in the brain,which eventually leads to specific neurological disorders.Aggressive treatment strategies for gastrointestinal disorders may protect against specific immune responses to gastrointestinal disorders,which can lead to potential protective effects in the CNS.Accordingly,this study investigated the mutual effects of microbiota and the gut–brain axis,which may provide targeting strategies for future disease treatment.展开更多
The central nervous system is characterized by a peculiar vascularization termed blood–brain barrier(BBB),which regulates the exchange of cells and molecules between the cerebral tissue and the whole body.BBB dysfunc...The central nervous system is characterized by a peculiar vascularization termed blood–brain barrier(BBB),which regulates the exchange of cells and molecules between the cerebral tissue and the whole body.BBB dysfunction is a life-threatening condition since its presence corresponds to a marker of severity in most diseases encountered in the intensive care unit(ICU).During critical illness,inflammatory response,cytokine release,and other phenomena activating the brain endothelium contribute to alterations in the BBB and increase its permeability to solutes,cells,nutrients,and xenobiotics.Moreover,patients in the ICU are often old,with underlying acute or chronic diseases,and overly medicated due to their critical condition;these factors could also contribute to the development of BBB dysfunction.An accurate diagnostic approach is critical for the identification of the mechanisms underlying BBB alterations,which should be rapidly managed by intensivists.Several methods were developed to investigate the BBB and assess its permeability.Nevertheless,in humans,exploration of the BBB requires the use of indirect methods.Imaging and biochemical methods can be used to study the abnormal passage of molecules through the BBB.In this review,we describe the structural and functional characteristics of the BBB,present tools and methods for probing this interface,and provide examples of the main diseases managed in the ICU that are related to BBB dysfunction.展开更多
Background:Disruption of the blood–brain barrier(BBB)after a stroke can lead to brain injury and neurological impairment.Previous work confirmed the involvement of the immunoproteasome subunit of low molecular mass p...Background:Disruption of the blood–brain barrier(BBB)after a stroke can lead to brain injury and neurological impairment.Previous work confirmed the involvement of the immunoproteasome subunit of low molecular mass peptide 2(LMP2)in the pathophysiology of ischemia stroke.However,the relationship between the immunoproteasome LMP2 and the BBB remains unclear.Methods:Adult male Sprague–Dawley rats were subjected to transient middle cerebral artery occlusion/reperfusion(MCAO/R).Three days before MCAO,the rats were treated with lentivirus-mediated LMP2 shRNA preparations by stereotactical injection into the ipsilateral hemispheric region.The rat brain microvascular endothelial cell(RBMVEC)line was exposed to oxygen–glucose deprivation/reperfusion(OGD/R)to mimic ischemic conditions in vitro.The RNA interference-mediated knockdown of LMP2 orβ-catenin was analysed in vivo and in vitro.Analysis of the quantity of extravasated Evans blue(EB)and cerebral fluorescent angiography were performed to evaluate the integrity of the BBB.Immunofluorescence and Western blotting were employed to detect the expression of target proteins.Cell migration was evaluated using a scratch migration assay.The results of immunofluorescence,Western blotting and cell migration were quantified using the software ImageJ(Version 1.53).Parametric data from different groups were compared using one-way ANOVA followed by the least significant difference(LSD)test.Results:Cerebral ischemia led to lower levels of structural components of the BBB such as tight junction proteins[occludin,claudin-1 and zonula occludens(ZO-1)]in the MCAO/R group compared with the sham group(P<0.001).However,inhibition of the immunoproteasome LMP2 restored the expression of these proteins,resulting in higher levels of occludin,claudin-1 and ZO-1 in the LMP2-shRNA group compared with the control-shRNA group(P<0.001).In addition,inhibition of the immunoproteasome LMP2 contributed to higher microvascular density and decreased BBB permeability[e.g.,the quantity of extravasate展开更多
基金funded by the National Natural Science Foundation of China(Nos.31571016 and 81402866)
文摘Due to the ability of the blood–brain barrier(BBB) to prevent the entry of drugs into the brain, it is a challenge to treat central nervous system disorders pharmacologically. The development of nanotechnology provides potential to overcome this problem. In this review, the barriers to brain-targeted drug delivery are reviewed, including the BBB, blood–brain tumor barrier(BBTB), and nose-to-brain barrier. Delivery strategies are focused on overcoming the BBB, directly targeting diseased cells in the brain, and dual-targeted delivery. The major concerns and perspectives on constructing brain-targeted delivery systems are discussed.
基金supported by the National Natural Science Funds of China (21602030 and 81172993)National Basic Research Program of China (973 Program, 2013CB932500), Shanghai Sailing Program (16YF1400900)+1 种基金Scientific Research Foundation of Fudan University for Talent Introduction (JJF301103)National Science Fund for Distinguished Young Scholars (81425023)
文摘The blood–brain barrier(BBB) and the poor ability of many drugs to cross that barrier greatly limits the efficacy of chemotherapies for glioblastoma multiforme(GBM). The present study exploits albumin as drug delivery vehicle to promote the chemotherapeutic efficacy of paclitaxel(PTX) by improving the stability and targeting efficiency of PTX/albumin nanoparticles(NPs). Here we characterize PTX-loaded human serum albumin(HSA) NPs stabilized with intramolecular disulfide bonds and modified with substance P(SP) peptide as the targeting ligand. The fabricated SP-HSA-PTX NPs exhibited satisfactory drug-loading content(7.89%) and entrapment efficiency(85.7%) with a spherical structure(about 150 nm) and zeta potential of -12.0 mV. The in vitro drug release from SP-HSA-PTX NPs occurred in a redox-responsive manner. Due to the targeting effect of the SP peptide, cellular uptake of SP-HSA-PTX NPs into brain capillary endothelial cells(BCECs) and U87 cells was greatly improved.The low IC_(50), prolonged survival period and the obvious pro-apoptotic effect shown by TUNEL analysis all demonstrated that the fabricated SP-HSA-PTX NPs showed a satisfactory anti-tumor effect and could serve as a novel strategy for GBM treatment.
基金financial support from the National Natural Science Foundation of China(No.81573616,81690263 and81773911,China)the Development Project of Shanghai Peak Disciplines-Integrated Medicine(No.20150407,China)
文摘Chemotherapy outcomes for the treatment of glioma remains unsatisfactory due to the inefficient drug transport across the blood–brain barrier(BBB) and insufficient drug accumulation in the tumor region. Although many approaches, including various nanosystems, have been developed to promote the distribution of chemotherapeutics in the brain tumor, the delivery efficiency and the possible damage to the normal brain function still greatly restrict the clinical application of the nanocarriers.Therefore, it is urgent and necessary to discover more safe and effective BBB penetration and gliomatargeting strategies. In the present study, menthol, one of the strongest BBB penetration enhancers screened from traditional Chinese medicine, was conjugated to casein, a natural food protein with brain targeting capability. Then the conjugate self-assembled into the nanoparticles to load anti-cancer drugs.The nanoparticles were characterized to have appropriate size, spheroid shape and high loading drug capacity. Tumor spheroid penetration experiments demonstrated that penetration ability of mentholmodified casein nanoparticles(M-CA-NP) into the tumor were much deeper than that of unmodified nanoparticles. In vivo imaging further verified that M-CA-NPs exhibited higher brain tumor distribution than unmodified nanoparticles. The median survival time of glioma-bearing mice treated with HCPT-MCA-NPs was significantly prolonged than those treated with free HCPT or HCPT-CA-NPs. HE staining ofthe organs indicated the safety of the nanoparticles. Therefore, the study combined the advantages of traditional Chinese medicine strategy with modern delivery technology for brain targeting, and provide a safe and effective approach for glioma therapy.
基金supported by the Shanghai Rising-Star Program of China (13QA1403400)Shanghai Talent Development Funds (201665)+3 种基金Natural Science Foundation of China (81773909)Excellent Youth Program of Shanghai Municipal Commission of Health and Family Planning (2017YQ060)Medical Profession Scholarship of Shanghai University of Traditional Chinese MedicineThe Open Project Program of Key Lab of Smart Drug Delivery, Fudan University (SDD2017-01)
文摘Brain tumor incidence shows an upward trend in recent years; brain tumors account for 5% of adult tumors, while in children, this figure has increased to 70%. Moreover, 20%–30% of malignant tumors will eventually metastasize into the brain. Both benign and malignant tumors can cause an increase in intracranial pressure and brain tissue compression, leading to central nervous system(CNS) damage which endangers the patients' lives. Despite the many approaches to treating brain tumors and the progress that has been made, only modest gains in survival time of brain tumor patients have been achieved. At present, chemotherapy is the treatment of choice for many cancers, but the special structure of the blood–brain barrier(BBB) limits most chemotherapeutic agents from passing through the BBB and penetrating into tumors in the brain. The BBB microenvironment contains numerous cell types, including endothelial cells, astrocytes, peripheral cells and microglia, and extracellular matrix(ECM). Many chemical components of natural products are reported to regulate the BBB microenvironment near brain tumors and assist in their treatment. This review focuses on the composition and function of the BBB microenvironment under both physiological and pathological conditions, and the current research progress in regulating the BBB microenvironment by natural products to promote the treatment of brain tumors.
基金supported by the Youth Psychological Development Base in China
文摘Major depressive disorder (MDD) is the most common nonfatal disease burden world-wide. Systemic chronic low-grade inflammation has been reported to be associated with MDD pro-gression by affecting monoaminergic and glutamatergic neurotransmission. However,whether various proinflammatory cytokines are abnormally elevated before the first episode of depression is still largely unclear. Here,we evaluated 184 adolescent patients who were experiencing their first episode of depressive disorder,and the same number of healthy individuals was included as con-trols. We tested the serum levels of high-sensitivity C-reactive protein (hs-CRP),tumor necrosis factor-α(TNF-α),IgE,14 different types of food antigen-specific IgG,histamine,homocysteine,S100 calcium-binding protein B,and diamine oxidase. We were not able to find any significant dif-ferences in the serum levels of hs-CRP or TNF-αbetween the two groups. However,the histamine level of the patients (12.35μM) was significantly higher than that of the controls (9.73μM,P<0.001,Mann–Whitney U test). Moreover,significantly higher serum food antigen-specific IgG positive rates were also found in the patient group. Furthermore,over 80% of patients exhibited prolonged food intolerance with elevated levels of serum histamine,leading to hyperpermeability of the blood–brain barrier,which has previously been implicated in the pathogen-esis of MDD. Hence,prolonged high levels of serum histamine could be a risk factor for depressive disorders,and antihistamine release might represent a novel therapeutic strategy for depression treatment.
基金supported by the Natural Science Foundation of Shandong Province,No.ZR2022MH124the Youth Science Foundation of Shandong First Medical University,No.202201–105(both to YX)。
文摘Subarachnoid hemorrhage leads to a series of pathological changes,including vascular spasm,cellular apoptosis,blood–brain barrier damage,cerebral edema,and white matter injury.Microglia,which are the key immune cells in the central nervous system,maintain homeostasis in the neural environment,support neurons,mediate apoptosis,participate in immune regulation,and have neuroprotective effects.Increasing evidence has shown that microglia play a pivotal role in the pathogenesis of subarachnoid hemorrhage and affect the process of injury and the prognosis of subarachnoid hemorrhage.Moreover,microglia play certain neuroprotective roles in the recovery phase of subarachnoid hemorrhage.Several approaches aimed at modulating microglia function are believed to attenuate subarachnoid hemorrhage injury.This provides new targets and ideas for the treatment of subarachnoid hemorrhage.However,an in-depth and comprehensive summary of the role of microglia after subarachnoid hemorrhage is still lacking.This review describes the activation of microglia after subarachnoid hemorrhage and their roles in the pathological processes of vasospasm,neuroinflammation,neuronal apoptosis,blood–brain barrier disruption,cerebral edema,and cerebral white matter lesions.It also discusses the neuroprotective roles of microglia during recovery from subarachnoid hemorrhage and therapeutic advances aimed at modulating microglial function after subarachnoid hemorrhage.Currently,microglia in subarachnoid hemorrhage are targeted with TLR inhibitors,nuclear factor-κB and STAT3 pathway inhibitors,glycine/tyrosine kinases,NLRP3 signaling pathway inhibitors,Gasdermin D inhibitors,vincristine receptorαreceptor agonists,ferroptosis inhibitors,genetic modification techniques,stem cell therapies,and traditional Chinese medicine.However,most of these are still being evaluated at the laboratory stage.More clinical studies and data on subarachnoid hemorrhage are required to improve the treatment of subarachnoid hemorrhage.
基金supported by the National Natural Science Foundation of China,Nos.31871477,32170971 (both to SQ)the Qing-Feng Scholar Research Foundation of Shanghai Medical College,Fudan University,No.QF2212 (to HT)。
文摘Tanycytes, specialized ependymal cells located in the hypothalamus, play a crucial role in the generation of new neurons that contribute to the neural circuits responsible for regulating the systemic energy balance. The precise coordination of the gene networks controlling neurogenesis in naive and mature tanycytes is essential for maintaining homeostasis in adulthood. However, our understanding of the molecular mechanisms and signaling pathways that govern the proliferation and differentiation of tanycytes into neurons remains limited. This article aims to review the recent advancements in research into the mechanisms and functions of tanycyte-derived neurogenesis. Studies employing lineage-tracing techniques have revealed that the neurogenesis specifically originating from tanycytes in the hypothalamus has a compensatory role in neuronal loss and helps maintain energy homeostasis during metabolic diseases. Intriguingly,metabolic disorders are considered early biomarkers of Alzheimer's disease. Furthermore,the neurogenic potential of tanycytes and the state of newborn neurons derived from tanycytes heavily depend on the maintenance of mild microenvironments, which may be disrupted in Alzheimer's disease due to the impaired blood–brain barrier function.However, the specific alterations and regulatory mechanisms governing tanycyte-derived neurogenesis in Alzheimer's disease remain unclear. Accumulating evidence suggests that tanycyte-derived neurogenesis might be impaired in Alzheimer's disease, exacerbating neurodegeneration. Confirming this hypothesis, however, poses a challenge because of the lack of long-term tracing and nucleus-specific analyses of newborn neurons in the hypothalamus of patients with Alzheimer's disease. Further research into the molecular mechanisms underlying tanycyte-derived neurogenesis holds promise for identifying small molecules capable of restoring tanycyte proliferation in neurodegenerative diseases. This line of investigation could provide valuable insights into potential therapeu
基金The authors wish to acknowledge NIPER–Ahmedabad(No.NIPERA160712)for providing all the facilitiestheir grant of a Junior Research Scholarship to Ms.Rudree Pathak to carry out this work。
文摘Intranasal drug administration is receiving increased attention as a delivery method for by-passing the blood–brain barrier and rapidly targeting therapeutics to the CNS.However,rapid mucociliary clearance in the nasal cavity is a major hurdle.The purpose of this study was to evaluate the effect of mucoadhesive polymers in enhancing the delivery of nimodipine microemulsion to the brain via the intranasal route.The optimized mucoadhesive microemulsion was characterized,and the in vitro drug release and in vivo nasal absorption of drug from the new formulation were evaluated in rats.The optimized formulation consisted of Capmul MCM as oil,Labrasol as surfactant,and Transcutol P as co-surfactant,with a particle size of 250 nm and zeta potential value of?15 mV.In vitro and ex vivo permeation studies showed an initial burst of drug release at 30 min and sustained release up to 6 h,attributable to the presence of free drug entrapped in the mucoadhesive layer.In vivo pharmacokinetic studies in rats showed that the use of the mucoadhesive microemulsion enhanced brain and plasma concentrations of nimodipine.These results suggest that incorporation of a mucoadhesive agent in a microemulsion intranasal delivery system can increase the retention time of the formulation and enhance brain delivery of drugs.
基金supported by the National Natural Science Foundation of China,Nos.82060219,82271234the Natural Science Foundation of Jiangxi Province,Nos.20212ACB216009,20212BAB216048+1 种基金Jiangxi Province Thousands of Plans,No.jxsq2019201023Youth Team Project of the Second Affiliated Hospital of Nanchang University,No.2019YNTD12003(all to FH)。
文摘Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple roles of mononuclear macrophages in the neuroinflammatory process. Monocytes play a significant role in neuroinflammation, and managing neuroinflammation by manipulating peripheral monocytes stands out as an effective strategy for the treatment of multiple sclerosis, leading to improved patient outcomes. This review outlines the steps involved in the entry of myeloid monocytes into the central nervous system that are targets for effective intervention: the activation of bone marrow hematopoiesis, migration of monocytes in the blood, and penetration of the blood–brain barrier by monocytes. Finally, we summarize the different monocyte subpopulations and their effects on the central nervous system based on phenotypic differences. As activated microglia resemble monocyte-derived macrophages, it is important to accurately identify the role of monocyte-derived macrophages in disease. Depending on the roles played by monocyte-derived macrophages at different stages of the disease, several of these processes can be interrupted to limit neuroinflammation and improve patient prognosis. Here, we discuss possible strategies to target monocytes in neurological diseases, focusing on three key aspects of monocyte infiltration into the central nervous system, to provide new ideas for the treatment of neurodegenerative diseases.
基金supported by the National Natural Science Foundation of China,Nos.82071291(to YY),82301464(to HM)the Norman Bethune Health Science Center of Jilin University,No.2022JBGS03(to YY)+2 种基金a grant from Department of Science and Technology of Jilin Province,Nos.YDZJ202302CXJD061(to YY),20220303002SF(to YY)a grant from Jilin Provincial Key Laboratory,No.YDZJ202302CXJD017(to YY)Talent Reserve Program of First Hospital of Jilin University,No.JDYYCB-2023002(to ZNG)。
文摘Current therapeutic strategies for ischemic stroke fall short of the desired objective of neurological functional recovery.Therefore,there is an urgent need to develop new methods for the treatment of this condition.Exosomes are natural cell-derived vesicles that mediate signal transduction between cells under physiological and pathological conditions.They have low immunogenicity,good stability,high delivery efficiency,and the ability to cross the blood–brain barrier.These physiological properties of exosomes have the potential to lead to new breakthroughs in the treatment of ischemic stroke.The rapid development of nanotechnology has advanced the application of engineered exosomes,which can effectively improve targeting ability,enhance therapeutic efficacy,and minimize the dosages needed.Advances in technology have also driven clinical translational research on exosomes.In this review,we describe the therapeutic effects of exosomes and their positive roles in current treatment strategies for ischemic stroke,including their antiinflammation,anti-apoptosis,autophagy-regulation,angiogenesis,neurogenesis,and glial scar formation reduction effects.However,it is worth noting that,despite their significant therapeutic potential,there remains a dearth of standardized characterization methods and efficient isolation techniques capable of producing highly purified exosomes.Future optimization strategies should prioritize the exploration of suitable isolation techniques and the establishment of unified workflows to effectively harness exosomes for diagnostic or therapeutic applications in ischemic stroke.Ultimately,our review aims to summarize our understanding of exosome-based treatment prospects in ischemic stroke and foster innovative ideas for the development of exosome-based therapies.
基金supported by the National Natural Science Foundation of China,Nos.82301486(to SL)and 82071325(to FY)Medjaden Academy&Research Foundation for Young Scientists,No.MJR202310040(to SL)+2 种基金Nanjing Medical University Science and Technique Development,No.NMUB20220060(to SL)Medical Scientific Research Project of Jiangsu Commission of Health,No.ZDA2020019(to JZ)Health China Buchang Zhiyuan Public Welfare Project for Heart and Brain Health,No.HIGHER202102(to QD).
文摘Acute ischemic stroke is a clinical emergency and a condition with high morbidity,mortality,and disability.Accurate predictive,diagnostic,and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain undetermined.With innovations in high-throughput gene sequencing analysis,many aberrantly expressed non-coding RNAs(ncRNAs)in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental models.Differentially expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes,leading to neuroprotection or deterioration,thus ncRNAs can serve as therapeutic targets in acute ischemic stroke.Moreover,distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.In particular,ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic stroke.In this review,we consolidate the latest progress of research into the roles of ncRNAs(microRNAs,long ncRNAs,and circular RNAs)in the pathological processes of acute ischemic stroke–induced brain damage,as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.Findings from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.
基金partially supported by the National Natural Science Foundation of China(81702457)the Clinical Medical University and Hospital Joint Construction of Disciplinary Projects 2021(2021lcxk017)+4 种基金the Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Cancer(2020B121201004)the Outstanding Youths Development Scheme of Nanfang Hospital,Southern Medical University(2021J008)the Basic and Clinical Cooperative Research and Promotion Program of Anhui Medical University(2021xkjT028)the Open Fund of Key Laboratory of Antiinflammatory and Immune Medicine(KFJJ-2021-11)Grants for Scientific Research of BSKY from Anhui Medical University(1406012201)。
文摘Glioblastoma multiforme(GBM) is the most common primary malignant brain tumor, and it is associated with poor prognosis. Its characteristics of being highly invasive and undergoing heterogeneous genetic mutation, as well as the presence of the blood–brain barrier(BBB), have reduced the efficacy of GBM treatment. The emergence of a novel therapeutic method, namely, sonodynamic therapy(SDT), provides a promising strategy for eradicating tumors via activated sonosensitizers coupled with low-intensity ultrasound. SDT can provide tumor killing effects for deep-seated tumors, such as brain tumors. However, conventional sonosensitizers cannot effectively reach the tumor region and kill additional tumor cells, especially brain tumor cells. Efforts should be made to develop a method to help therapeutic agents pass through the BBB and accumulate in brain tumors. With the development of novel multifunctional nanosensitizers and newly emerging combination strategies, the killing ability and selectivity of SDT have greatly improved and are accompanied with fewer side effects. In this review, we systematically summarize the findings of previous studies on SDT for GBM, with a focus on recent developments and promising directions for future research.
基金supported by the grants from the Spanish Ministry of Economy and Competitiveness(SAF2017-85602-R)the Spanish Ministry of Science and Innovation(PID2020-119638RB-I00 to EGR)FPU-program(FPU17/02616 to JCG)。
文摘The blood–brain barrier constitutes a dynamic and interactive boundary separating the central nervous system and the peripheral circulation.It tightly modulates the ion transport and nutrient influx,while restricting the entry of harmful factors,and selectively limiting the migration of immune cells,thereby maintaining brain homeostasis.Despite the well-established association between blood–brain barrier disruption and most neurodegenerative/neuroinflammatory diseases,much remains unknown about the factors influencing its physiology and the mechanisms underlying its breakdown.Moreover,the role of blood–brain barrier breakdown in the translational failure underlying therapies for brain disorders is just starting to be understood.This review aims to revisit this concept of“blood–brain barrier breakdown,”delving into the most controversial aspects,prevalent challenges,and knowledge gaps concerning the lack of blood–brain barrier integrity.By moving beyond the oversimplistic dichotomy of an“open”/“bad”or a“closed”/“good”barrier,our objective is to provide a more comprehensive insight into blood–brain barrier dynamics,to identify novel targets and/or therapeutic approaches aimed at mitigating blood–brain barrier dysfunction.Furthermore,in this review,we advocate for considering the diverse time-and location-dependent alterations in the blood–brain barrier,which go beyond tight-junction disruption or brain endothelial cell breakdown,illustrated through the dynamics of ischemic stroke as a case study.Through this exploration,we seek to underscore the complexity of blood–brain barrier dysfunction and its implications for the pathogenesis and therapy of brain diseases.
基金the National Basic Research Program of China(973 Program Nos.2013CB932503 and 2014CB931900)National Natural Science Foundation of China(Nos.81172996,81373357,81422048 and 81361140344)
文摘Brain delivery of macromolecular therapeutics (e.g., proteins) remains an unsolved problem because of the formidable blood brain bather (BBB). Although a direct pathway of nose-to-brain transfer provides an answer to circumventing the BBB and has already been intensively investigated for brain delivery of small drugs, new challenges arise for intranasal delivery of proteins because of their larger size and hydrophilicity. h order to overcome the bathers and take advantage of available pathways (e.g., epithelial tight junctions, uptake by olfactory neurons, transport into brain tissues, and intra-brain diffusion), a low molecular weight protamine (LMWP) cell-penetrating peptide was utilized to facilitate nose-to-brain transport. Cell-penetrating peptides (CPP) have been widely used to mediate macromolecular delivery through many kinds of biobarriers. Our results show that conjugates of LMWP proteinsare able to effectively penetrate into the brain after intranasal administration. The CPP-based intranasal method highlights a promising solution for protein therapy of brain diseases. (C) 2016 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.
文摘The central nervous system(CNS)is a reservoir of immune privilege.Specialized immune glial cells are responsible for maintenance and defense against foreign invaders.The blood–brain barrier(BBB)prevents detrimental pathogens and potentially overreactive immune cells from entering the periphery.When the double-edged neuroinflammatory response is overloaded,it no longer has the protective function of promoting neuroregeneration.Notably,microbiota and its derivatives may emerge as pathogen-associated molecular patterns of brain pathology,causing microbiome–gut–brain axis dysregulation from the bottom-up.When dysbiosis of the gastrointestinal flora leads to subsequent alterations in BBB permeability,peripheral immune cells are recruited to the brain.This results in amplification of neuroinflammatory circuits in the brain,which eventually leads to specific neurological disorders.Aggressive treatment strategies for gastrointestinal disorders may protect against specific immune responses to gastrointestinal disorders,which can lead to potential protective effects in the CNS.Accordingly,this study investigated the mutual effects of microbiota and the gut–brain axis,which may provide targeting strategies for future disease treatment.
文摘The central nervous system is characterized by a peculiar vascularization termed blood–brain barrier(BBB),which regulates the exchange of cells and molecules between the cerebral tissue and the whole body.BBB dysfunction is a life-threatening condition since its presence corresponds to a marker of severity in most diseases encountered in the intensive care unit(ICU).During critical illness,inflammatory response,cytokine release,and other phenomena activating the brain endothelium contribute to alterations in the BBB and increase its permeability to solutes,cells,nutrients,and xenobiotics.Moreover,patients in the ICU are often old,with underlying acute or chronic diseases,and overly medicated due to their critical condition;these factors could also contribute to the development of BBB dysfunction.An accurate diagnostic approach is critical for the identification of the mechanisms underlying BBB alterations,which should be rapidly managed by intensivists.Several methods were developed to investigate the BBB and assess its permeability.Nevertheless,in humans,exploration of the BBB requires the use of indirect methods.Imaging and biochemical methods can be used to study the abnormal passage of molecules through the BBB.In this review,we describe the structural and functional characteristics of the BBB,present tools and methods for probing this interface,and provide examples of the main diseases managed in the ICU that are related to BBB dysfunction.
基金supported by the National Natural Science Foundation of China(81771250)the Natural Science Foundation of Fujian Province,China(2020J011059,2020R1011004)+1 种基金the Joint Funds for the Innovation of Science and Technology of Fujian Province,China(2017Y9065)the High-level hospital foster grants from Fujian Provincial Hospital,Fujian Province,China(2020HSJJ07)。
文摘Background:Disruption of the blood–brain barrier(BBB)after a stroke can lead to brain injury and neurological impairment.Previous work confirmed the involvement of the immunoproteasome subunit of low molecular mass peptide 2(LMP2)in the pathophysiology of ischemia stroke.However,the relationship between the immunoproteasome LMP2 and the BBB remains unclear.Methods:Adult male Sprague–Dawley rats were subjected to transient middle cerebral artery occlusion/reperfusion(MCAO/R).Three days before MCAO,the rats were treated with lentivirus-mediated LMP2 shRNA preparations by stereotactical injection into the ipsilateral hemispheric region.The rat brain microvascular endothelial cell(RBMVEC)line was exposed to oxygen–glucose deprivation/reperfusion(OGD/R)to mimic ischemic conditions in vitro.The RNA interference-mediated knockdown of LMP2 orβ-catenin was analysed in vivo and in vitro.Analysis of the quantity of extravasated Evans blue(EB)and cerebral fluorescent angiography were performed to evaluate the integrity of the BBB.Immunofluorescence and Western blotting were employed to detect the expression of target proteins.Cell migration was evaluated using a scratch migration assay.The results of immunofluorescence,Western blotting and cell migration were quantified using the software ImageJ(Version 1.53).Parametric data from different groups were compared using one-way ANOVA followed by the least significant difference(LSD)test.Results:Cerebral ischemia led to lower levels of structural components of the BBB such as tight junction proteins[occludin,claudin-1 and zonula occludens(ZO-1)]in the MCAO/R group compared with the sham group(P<0.001).However,inhibition of the immunoproteasome LMP2 restored the expression of these proteins,resulting in higher levels of occludin,claudin-1 and ZO-1 in the LMP2-shRNA group compared with the control-shRNA group(P<0.001).In addition,inhibition of the immunoproteasome LMP2 contributed to higher microvascular density and decreased BBB permeability[e.g.,the quantity of extravasate
