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Abstract The blood-brain barrier (BBB) is a critical interface that maintains the central nervous system homeostasis by controlling the exchange of substances between the blood and the brain. Disruption of the BBB plays a vital role in the development of neuroinflammation and neurological dysfunction in sepsis, but the mechanisms by which the BBB becomes disrupted during sepsis are not well understood. Here, we induced endotoxemia, a major type of sepsis, in mice by intraperitoneal injection of lipopolysaccharide (LPS). LPS acutely increased BBB permeability, activated microglia, and heightened inflammatory responses in brain endothelium and parenchyma. Concurrently, LPS or proinflammatory cytokines activated the NF-κB pathway, inhibiting Wnt/β-catenin signaling in brain endothelial cells in vitro and in vivo. Cell culture study revealed that NF-κB p65 directly interacted with β-catenin to suppress Wnt/β-catenin signaling. Pharmacological NF-κB pathway inhibition restored brain endothelial Wnt/β-catenin signaling activity and mitigated BBB disruption and neuroinflammation in septic mice. Furthermore, genetic or pharmacological activation of brain endothelial Wnt/β-catenin signaling substantially alleviated LPS-induced BBB leakage and neuroinflammation, while endothelial conditional ablation of the Wnt7a/7b co-receptor Gpr124 exacerbated the BBB leakage caused by LPS. Mechanistically, Wnt/β-catenin signaling activation rectified the reduced expression levels of tight junction protein ZO-1 and transcytosis suppressor Mfsd2a in brain endothelial cells of mice with endotoxemia, inhibiting both paracellular and transcellular permeability of the BBB. Our findings demonstrate that endotoxemia-associated systemic inflammation decreases endothelial Wnt/β-catenin signaling through activating NF-κB pathway, resulting in acute BBB disruption and neuroinflammation. Targeting the endothelial Wnt/β-catenin signaling may offer a promising therapeutic strategy for preserving BBB integrity and treating neurological dysfunction in sepsis.

Abstract Obesity, a burgeoning global health issue, is increasingly recognized for its detrimental effects on the central nervous system, particularly concerning the integrity of the blood-brain barrier (BBB). This manuscript delves into the intricate relationship between obesity and BBB dysfunction, elucidating the underlying phenotypes and molecular mechanisms. We commence with an overview of the BBB’s critical role in maintaining cerebral homeostasis and the pathological alterations induced by obesity. By employing a comprehensive literature review, we examine the structural and functional modifications of the BBB in the context of obesity, including increased permeability, altered transport mechanisms, and inflammatory responses. The manuscript highlights how obesity-induced systemic inflammation and metabolic dysregulation contribute to BBB disruption, thereby predisposing individuals to various neurological disorders. We further explore the potential pathways, such as oxidative stress and endothelial cell dysfunction, that mediate these changes. Our discussion culminates in the summary of current findings and the identification of knowledge gaps, paving the way for future research directions. This review underscores the significance of understanding BBB dysfunction in obesity, not only for its implications in neurodegenerative diseases but also for developing targeted therapeutic strategies to mitigate these effects.

Salvianolic acid A (SalA), a bioactive compound extracted from Salvia miltiorrhiza, has garnered considerable interest for its potential in ameliorating the post-stroke neuroinflammation. This review delineates the possible molecular underpinnings of anti-inflammatory and neuroprotective roles of SalA, offering a comprehensive analysis of its therapeutic efficacy in preclinical studies of ischemic stroke. We explore the intricate interplay between post-stroke neuroinflammation and the modulatory effects of SalA on pro-inflammatory cytokines, inflammatory signaling pathways, the peripheral immune cell infiltration through blood-brain barrier disruption, and endothelial cell function. The pharmacokinetic profiles of SalA in the context of stroke, characterized by enhanced cerebral penetration post-ischemia, makes it particularly suitable as a therapeutic agent. Preliminary clinical findings have demonstrated that salvianolic acids (SA) has a positive impact on cerebral perfusion and neurological deficits in stroke patients, warranting further investigation. This review emphasizes SalA as a potential anti-inflammatory agent for the advancement of innovative therapeutic approaches in the treatment of ischemic stroke.

The objective of this study was to investigate the effects of yucca extract (YE) supplementation on estrus, nutrient digestibility, antioxidant capacity and fecal microorganisms of gilts. Twenty gilts were randomly divided into two groups: basal diet (CONT) and basal diet + 0.25 g/kg YE (YETG). The results showed that supplementing 0.25 g/kg YE in the diet of gilts significantly increased the apparent digestibility of dietary energy, crude fat and crude protein (p < 0.05). In addition, YE could also improve the antioxidant capacity of gilts, significantly increase the serum total antioxidant capacity (T-AOC) activity and decrease the malondialdehyde (MDA) content of gilts (p < 0.05). In terms of fecal microorganisms, YE significantly increased the Shannon index and Simpson index of fecal microorganisms of gilts (p < 0.05), decreased the abundance of Proteobacteria, Actinobacteriota and Streptococcus sp., and increased the abundance of Muribaculaceae and Prevotalla sp. in the feces of gilts (p < 0.05). In conclusion, dietary YE increased the apparent digestibility of nutrients, improved the antioxidant status of gilts and increased the α diversity of fecal microorganisms. These results provide a reference for the application of YE in gilts production.

Summary: The blood-brain barrier (BBB) is primarily manifested by a variety of physiological properties of brain endothelial cells (ECs), but the molecular foundation for these properties remains incompletely clear. Here, we generate a comprehensive molecular atlas of adult brain ECs using acutely purified mouse ECs and integrated multi-omics. Using RNA sequencing (RNA-seq) and proteomics, we identify the transcripts and proteins selectively enriched in brain ECs and demonstrate that they are partially correlated. Using single-cell RNA-seq, we dissect the molecular basis of functional heterogeneity of brain ECs. Using integrative epigenomics and transcriptomics, we determine that TCF/LEF, SOX, and ETS families are top-ranked transcription factors regulating the BBB. We then validate the identified brain-EC-enriched proteins and transcription factors in normal mouse and human brain tissue and assess their expression changes in mice with Alzheimer’s disease. Overall, we present a valuable resource with broad implications for regulation of the BBB and treatment of neurological disorders.

The purpose of this study is to investigate the effects of supplementing Yeast−derived postbiotics (Y−dP) to the diet of sows during late pregnancy and lactation on fecal microbiota and short−chain fatty acids (SCFA) in sows and their offspring weaned piglets, as well as the relationship between gut microbiota and SCFA, serum cytokines, and sow reproductive performance. A total of 150 sows were divided into three groups: control diet (CON), CON + Y−dP 1.25 g/kg, and CON + Y−dP 2 g/kg. The results showed that supplementing 0.125% Y−dP to the diet of sows can increase the content of isobutyric acid (IBA) in the feces of pregnant sows and reduce the content of butyric acid (BA) in the feces of weaned piglets (p < 0.05). The fecal microbiota of pregnant sows β diversity reduced and piglet fecal microbiota β diversity increased (p < 0.05). Y−dP significantly increased the abundance of Actinobacteria and Limosilactobacilli in the feces of pregnant sows (p < 0.05), as well as the abundance of Verrucomicrobiota, Bacteroidota, and Fusobacteriota in the feces of piglets (p < 0.05). The abundance of Bacteroidota in the feces of pregnant sows is positively correlated with propionic acid (PA) (r > 0.5, p < 0.05). The abundance of Prevotellaceae_NK3B31_group was positively correlated with Acetic acid (AA), PA, Valerate acid (VA), and total volatile fatty acid (TVFA) in the feces of pregnant sows (r > 0.5, p < 0.05), and Bacteroidota and Prevotellaceae_NK3B31_group were negatively correlated with the number of stillbirths (r < −0.5, p < 0.05). The abundance of Lactobacillus and Holdemanella in piglet feces was positively correlated with TVFA in feces and negatively correlated with IgA in serum (r > 0.5, p < 0.05). In conclusion, supplementing Y−dP to the diet of sows from late gestation to lactation can increase the chao1 index and α diversity of fecal microorganisms in sows during lactation, increase the abundance of Actinobacteria and Limosilactobacilli in the feces of sows during pregnancy, and increase the abundance of beneficial bacteria such as Bacteroidetes in piglet feces, thereby improving intestinal health. These findings provide a reference for the application of Y−dP in sow production and a theoretical basis for Y−dP to improve sow production performance.

Membrane viscosity is an important property of cell biology, which determines cellular function, development and disease progression. Various experimental and computational methods have been developed to investigate the mechanics of cells. However, there have been no experimental measurements of the membrane viscosity at high-frequencies in live cells. High frequency measurements are important because they can probe viscoelastic effects. Here, we investigate the membrane viscosity at gigahertz-frequencies through the damping of the acoustic vibrations of gold nanoplates. The experiments are modeled using a continuum mechanics theory which reveals that the membranes display viscoelasticity, with an estimated relaxation time of ca. 5.7+2.4/−2.7 ps. We further demonstrate that membrane viscoelasticity can be used to differentiate a cancerous cell line (the human glioblastoma cells LN-18) from a normal cell line (the mouse brain microvascular endothelial cells bEnd.3). The viscosity of cancerous cells LN-18 is lower than that of healthy cells bEnd.3 by a factor of three. The results indicate promising applications of characterizing membrane viscoelasticity at gigahertz-frequency in cell diagnosis.

Rapid upregulation of matrix metalloproteinase 9 (MMP-9) leads to blood-brain barrier (BBB) breakdown following stroke, but no MMP-9 inhibitors have been approved in clinic largely due to their low specificities and side effects. Here, we explored the therapeutic potential of a human IgG monoclonal antibody (mAb), L13, which was recently developed with exclusive neutralizing specificity to MMP-9, nanomolar potency, and biological function, using mouse stroke models and stroke patient samples. We found that L13 treatment at the onset of reperfusion following cerebral ischemia or after intracranial hemorrhage (ICH) significantly reduced brain tissue injury and improved the neurological outcomes of mice. Compared to control IgG, L13 substantially attenuated BBB breakdown in both types of stroke model by inhibiting MMP-9 activity-mediated degradations of basement membrane and endothelial tight junction proteins. Importantly, these BBB-protective and neuroprotective effects of L13 in wild-type mice were comparable to Mmp9 genetic deletion and fully abolished in Mmp9 knockout mice, highlighting the in vivo target specificity of L13. Meanwhile, ex vivo co-incubation with L13 significantly neutralized the enzymatic activities of human MMP-9 in the sera of ischemic and hemorrhagic stroke patients, or in the peri-hematoma brain tissues from hemorrhagic stroke patients. Overall, we demonstrated that MMP-9 exclusive neutralizing mAbs constitute a potential feasible therapeutic approach for both ischemic and hemorrhagic stroke.

The blood-brain barrier (BBB) prevents unregulated substance exchange between the central nervous system and the blood, while providing highly regulated transport of nutrients and tonic factors essential to brain metabolism. A group of carriers, transporters, and receptors is utilized by endothelial cells of the BBB to aid the influx and efflux of nutrients and metabolic wastes, and their function is subject to changes during metabolic disorders such as diabetes mellitus and obesity. This regulated barrier function of BBB is essential for maintaining the normal metabolism of the brain and transduction of metabolic signals from the periphery. As such, disruption of the BBB nutrient/hormone transport system has been proposed to be major contributors of many neurological diseases.

IntroductionThe effects of maternal addition of yeast cultures on offspring gut development and intestinal microorganisms are not yet known, so the aim of this study was to investigate the effects of maternal addition of yeast cultures to the diet of sows during late gestation and lactation on growth performance, antioxidant properties and intestinal microorganisms of offspring weaned piglets.Methods40 Landrace × Yorkshire sows (3–7 of parity) with similar backfat were randomly divided into two treatment groups: control diet (CON) and control diet +2.0 g/kg yeast culture (XPC), and the trial started on day 90 of gestation and ended on day 21 of lactation.ResultsThe results showed that maternal addition of yeast culture significantly increased weaned piglet weight and mean daily gain (p 0.05). Compared with the control group, the XPC group significantly increased the relative abundance of colonic chyme Bacteroidetes (p

Abstract Background The therapeutic efficacy of mesenchymal stem cells (MSCs) of different tissue origins on metabolic disorders can be varied in many ways but remains poorly defined. Here we report a comprehensive comparison of human MSCs derived from umbilical cord Wharton’s jelly (UC-MSCs), dental pulp (PU-MSCs), and adipose tissue (AD-MSCs) on the treatment of glucose and lipid metabolic disorders in type II diabetic mice. Methods Fourteen-to-fifteen-week-old male C57BL/6 db/db mice were intravenously administered with human UC-MSCs, PU-MSCs, and AD-MSCs at various doses or vehicle control once every 2 weeks for 6 weeks. Metformin (MET) was given orally to animals in a separate group once a day at weeks 4 to 6 as a positive control. Body weight, blood glucose, and insulin levels were measured every week. Glucose tolerance tests (GTT) and insulin tolerance tests (ITT) were performed every 2 weeks. All the animals were sacrificed at week 6 and the blood and liver tissues were collected for biochemical and histological examinations. Results UC-MSCs showed the strongest efficacy in reducing fasting glucose levels, increasing fasting insulin levels, and improving GTT and ITT in a dose-dependent manner, whereas PU-MSCs showed an intermediate efficacy and AD-MSCs showed the least efficacy on these parameters. Moreover, UC-MSCs also reduced the serum low-density lipoprotein cholesterol (LDL-C) levels with the most prominent potency and AD-MSCs had only very weak effect on LDL-C. In contrast, AD-MSCs substantially reduced the lipid content and histological lesion of liver and accompanying biomarkers of liver injury such as serum aspartate transaminase (AST) and alanine aminotransferase (ALT) levels, whereas UC-MSCs and PU-MSCs displayed no or modest effects on these parameters, respectively. Conclusions Taken together, our results demonstrated that MSCs of different tissue origins can confer substantially different therapeutic efficacy in ameliorating glucose and lipid metabolic disorders in type II diabetes. MSCs with different therapeutic characteristics could be selected according to the purpose of the treatment in the future clinical practice.

Disruption of the blood-brain barrier (BBB) causes or contributes to neuronal dysfunction and several central nervous system (CNS) disorders. Wnt/β-catenin signaling is essential for maintaining the integrity of the adult BBB in physiological and pathological conditions, including stroke. However, how the impairment of the endothelial Wnt/β-catenin signaling results in BBB breakdown remains unclear. Furthermore, the individual contributions of different BBB permeability-inducing mechanisms, including intercellular junction damage, endothelial transcytosis, and fenestration, remains unexplored. Here, we induced β-catenin endothelial-specific conditional knockout (ECKO) in adult mice and determined its impact on BBB permeability and the underlying mechanism. β-catenin ECKO reduced the levels of active β-catenin and the mRNA levels of Wnt target genes in mice, indicating downregulation of endothelial Wnt/β-catenin signaling. β-catenin ECKO mice displayed severe and widespread leakage of plasma IgG and albumin into the cerebral cortex, which was absent in wild-type controls. Mechanistically, both the paracellular and transcellular transport routes were disrupted in β-catenin ECKO mice. First, β-catenin ECKO reduced the tight junction protein levels and disrupted the intercellular junction ultrastructure in the brain endothelium. Second, β-catenin ECKO substantially increased the number of endothelial vesicles and caveolae-mediated transcytosis through downregulating Mfsd2a and upregulating caveolin-1 expression. Interestingly, fenestration and upregulated expression of the fenestration marker Plvap were not observed in β-catenin ECKO mice. Overall, our study reveals that endothelial Wnt/β-catenin signaling maintains adult BBB integrity via regulating the paracellular as well as transcellular permeability. These findings may have broad applications in understanding and treatment of CNS disorders involving BBB disruption.

Ischemic stroke is caused by insufficient cerebrovascular blood and oxygen supply. It is a major contributor to death or disability worldwide and has become a heavy societal and clinical burden. To date, effective treatments for ischemic stroke are limited, and innovative therapeutic methods are urgently needed. Hypoxia inducible factor-1α (HIF-1α) is a sensitive regulator of oxygen homeostasis, and its expression is rapidly induced after hypoxia/ischemia. It plays an extensive role in the pathophysiology of stroke, including neuronal survival, neuroinflammation, angiogenesis, glucose metabolism, and blood brain barrier regulation. In addition, the spatiotemporal expression profile of HIF-1α in the brain shifts with the progression of ischemic stroke; this has led to contradictory findings regarding its function in previous studies. Therefore, unveiling the Janus face of HIF-1α and its target genes in different type of cells and exploring the role of HIF-1α in inflammatory responses after ischemia is of great importance for revealing the pathogenesis and identifying new therapeutic targets for ischemic stroke. Herein, we provide a succinct overview of the current approaches targeting HIF-1α and summarize novel findings concerning HIF-1α regulation in different types of cells within neurovascular units, including neurons, endothelial cells, astrocytes, and microglia, during the different stages of ischemic stroke. The current representative translational approaches focused on neuroprotection by targeting HIF-1α are also discussed.

Following a cerebral ischemic event, substantial alterations in both cellular and molecular activities occur due to ischemia-induced cerebral pathology. Mounting evidence indicates that the robust recruitment of immune cells plays a central role in the acute stage of stroke. Infiltrating peripheral immune cells and resident microglia mediate neuronal cell death and blood-brain barrier disruption by releasing inflammation-associated molecules. Nevertheless, profound immunological effects in the context of the subacute and chronic recovery phase of stroke have received little attention. Early attempts to curtail the infiltration of immune cells were effective in mitigating brain injury in experimental stroke studies but failed to exert beneficial effects in clinical trials. Neural tissue damage repair processes include angiogenesis, neurogenesis, and synaptic remodeling, etc. Post-stroke inflammatory cells can adopt divergent phenotypes that influence the aforementioned biological processes in both endothelial and neural stem cells by either alleviating acute inflammatory responses or secreting a variety of growth factors, which are substantially involved in the process of angiogenesis and neurogenesis. To better understand the multiple roles of immune cells in neural tissue repair processes post stroke, we review what is known and unknown regarding the role of immune cells in angiogenesis, neurogenesis, and neuronal remodeling. A comprehensive understanding of these inflammatory mechanisms may help identify potential targets for the development of novel immunoregulatory therapeutic strategies that ameliorate complications and improve functional rehabilitation after stroke.

Background and PurposeRecent studies have shown that several proteins, including Axl, are related to hemorrhagic transformation (HT) following intravenous thrombolysis by affecting blood-brain barrier (BBB) function. However, the effects of these proteins on BBB function have been studied primarily in animal models. In this study, we aimed to identify serum protein markers that predict HT following intravenous thrombolysis in patients with acute ischemic stroke (AIS) and verify whether these serum proteins regulate BBB function and HT in animal stroke models.MethodsFirst, 118 AIS patients were enrolled in this study, including 52 HT patients and 66 non-HT patients. In Step 1, baseline serum levels of Axl, angiopoietin-like 4, C-reactive protein, ferritin, hypoxia-inducible factor-1 alpha, HTRA2, Lipocalin2, matrix metallopeptidase 9, platelet-derived growth factor-BB, and tumor necrosis factor alpha were measured using a quantitative cytokine chip. Next, sequence mutations and variations in genes encoding the differentially expressed proteins identified in Step 1 and subsequent function-related proteins were detected. Finally, we verified whether manipulation of differentially expressed proteins affected BBB function and HT in a hyperglycemia-induced rat stroke model.ResultsSerum Axl levels were significantly lower in the HT group than in the non-HT group; none of the other protein markers differed significantly between the two groups. Genetic testing revealed that sequence variations of GAS6 (the gene encoding the Axl ligand)-derived long non-coding RNA, GAS6-AS1, were significantly correlated with an increased risk of HT after intravenous thrombolysis. In animal studies, administration of recombinant GAS6 significantly reduced brain infarction and neurological deficits and attenuated BBB disruption and HT.ConclusionsLower serum Axl levels, which may result from sequence variations in GAS6-AS1, are correlated with an increased risk of HT after intravenous thrombolysis in stroke patients. Activation of the Axl signaling pathway by the GAS6 protein may serve as a therapeutic strategy to reduce HT in AIS patients.

The blood–brain barrier (BBB) plays a vital role in maintaining the specialized microenvironment of the neural tissue. It separates the peripheral circulatory system from the brain parenchyma while facilitating communication. Alterations in the distinct physiological properties of the BBB lead to BBB breakdown associated with normal aging and various neurodegenerative diseases. In this review, we first briefly discuss the aging process, then review the phenotypes and mechanisms of BBB breakdown associated with normal aging that further cause neurodegeneration and cognitive impairments. We also summarize dementia such as Alzheimer's disease (AD) and vascular dementia (VaD) and subsequently discuss the phenotypes and mechanisms of BBB disruption in dementia correlated with cognition decline. Overlaps between AD and VaD are also discussed. Techniques that could identify biomarkers associated with BBB breakdown are briefly summarized. Finally, we concluded that BBB breakdown could be used as an emerging biomarker to assist to diagnose cognitive impairment associated with normal aging and dementia.

Microcephaly (MCPH) is a genetically heterogeneous disorder characterized by non-progressive intellectual disability, small head circumference, and small brain size compared with the age- and sex-matched population. MCPH manifests as an isolated condition or part of another clinical syndrome; so far, 25 genes have been linked with MCPH. Many of these genes are reported in Pakistani population, but due to a high rate of consanguinity, a significant proportion of MCPH cohort is yet to be explored. MCPH5 is the most frequently reported type, accounting for up to 68.75% alone in a genetically constrained population like Pakistan. In the current study, whole exome sequencing (WES) was performed on probands from 10 families sampled from South Waziristan and two families from rural areas of the Pakistani Punjab. Candidate variants were validated through Sanger sequencing in all available family members. Variant filtering and in silico analysis identified three known mutations in ASPM, a MCPH5-associated gene. The founder mutation p.Trp1326* was segregating in 10 families, which further confirmed the evidence that it is the most prominent mutation in Pashtun ethnicity living in Pakistan and Afghanistan. Furthermore, the previously known mutations p.Arg3244* and p.Arg1019* were inherited in two families with Punjab ethnic profile. Collectively, this study added 12 more families to the mutational paradigm of ASPM and expanded the Pakistani MCPH cohort.

Ischemic stroke, caused by a sudden disruption of blood flow to the brain, is a leading cause of death and exerts a heavy burden on both patients and public health systems. Currently available treatments for ischemic stroke are very limited and are not feasible in many patients due to strict time windows required for their administration. Thus, novel treatment strategies are keenly required. T cells, which are part of the adaptive immune system, have gained more attention for its effects in ischemic stroke. Both preclinical and clinical studies have revealed the conflicting roles for T cells in post-stroke inflammation and as potential therapeutic targets. This review summarizes the mediators of T cell recruitment, as well as the temporal course of its infiltration through the blood-brain-barrier, choroid plexus, and meningeal pathways. Furthermore, we describe the mechanisms behind the deleterious and beneficial effects of T cells in the brain, in both antigen-dependent and antigen-independent manners, and finally we specifically focus on clinical and preclinical studies that have investigated T cells as potential therapeutic targets for ischemic stroke.

Oxidative stress-induced neuronal damage has been implicated to play a dominant role in neurodegenerative disorders, such as Alzheimer’s disease (AD). Nicotine, a principal additive compound for tobacco users, is thought as a candidate to attenuate amyloid-β-mediated neurotoxicity and NMDA-induced excitotoxicity. Previous studies demonstrated that nicotine exerted this neuroprotective action on oxidative stress. However, the mechanisms underlying how nicotine contributes on oxidative injury in immortalized hippocampal HT-22 cells remain largely unknown. Therefore, in this study we investigated that the potential effects of nicotine on hydrogen peroxide (H2O2)-induced oxidative injury and underlying mechanisms in HT-22 cells. We found that pretreatment with nicotine at low concentrations markedly recovered the cell cycle that was arrested at the G2/M phase in the presence of H2O2 through reduced intracellular ROS generation. Moreover, nicotine attenuated H2O2-induced mitochondrial dysfunctions. Mechanistically, the application of nicotine significantly upregulated the levels of phosphorylated Erk1/2. The neuroprotective effects of nicotine, in turn, were abolished by PD0325901, a selective Erk1/2 inhibitor. Further obtained investigation showed that nicotine exerted its neuroprotective effects via specifically activating α7 nicotinic acetylcholine receptors (α7-nAChRs). A selective inhibitor of α7-nAChRs, methyllycaconitine citrate (MLA), not only completely prevented nicotine-mediated antioxidation but also abolished expression of p-Erk1/2. Taken together, our findings suggest that nicotine suppresses H2O2-induced HT-22 cell injury through activating the α7-nAChR/Erk1/2 signaling pathway, which indicates that nicotine may be a novel strategy for the treatment of neurodegenerative disorders.

Up to now, the chemotherapy approaches for glioblastoma were limited. 1-[2-Thiazolylazo]-2-naphthol (named as NSC139021) was shown to significantly inhibit the proliferation of prostate cancer cells by targeting the atypical protein kinase RIOK2. It is documented that RIOK2 overexpressed in glioblastoma. However, whether NSC139021 can inhibit the growth of glioblastoma cells and be a potential drug for glioblastoma treatment need to be clarified. In this study, we investigated the effects of NSC139021 on human U118MG, LN-18, and mouse GL261 glioblastoma cells and the mouse models of glioblastoma. We verified that NSC139021 effectively inhibited glioblastoma cells proliferation, but it is independent of RIOK2. Our data showed that NSC139021 induced cell cycle arrest at G0/G1 phase via the Skp2-p27/p21-Cyclin E/CDK2-pRb signaling pathway in G1/S checkpoint regulation. In addition, NSC139021 also increased the apoptosis of glioblastoma cells by activating the p53 signaling pathway and increasing the levels of Bax and cleaved caspase 3. Furthermore, intraperitoneal administration of 150 mg/kg NSC139021 significantly suppressed the growth of human and mouse glioblastoma in vivo. Our study suggests that NSC139021 may be a potential chemotherapy drug for the treatment of glioblastoma by targeting the Skp2-p27/p21-Cyclin E/CDK2-pRb signaling pathway.

Summary: WNT7A and WNT7B control CNS angiogenesis and blood-brain barrier formation by activating endothelial Wnt/β-catenin signaling. The GPI-anchored protein RECK and adhesion G protein-coupled receptor GPR124 critically regulate WNT7-specific signaling in concert with FZD and LRP co-receptors. Here, we demonstrate that primarily the GPR124 ectodomain, but not its transmembrane and intracellular domains, mediates RECK/WNT7-induced canonical Wnt signaling. Moreover, RECK is the predominant binding partner of GPR124 in rat brain blood vessels in situ. WNT7A and WNT7B, but not WNT3A, directly bind to purified recombinant soluble RECK, full-length cell surface RECK, and the GPR124:RECK complex. Chemical cross-linking indicates that RECK and WNT7A associate with 1:1 stoichiometry, which stabilizes short-lived, active, monomeric, hydrophobic WNT7A. In contrast, free WNT7A rapidly converts into inactive, hydrophilic aggregates. Overall, RECK is a selective WNT7 receptor that mediates GPR124/FZD/LRP-dependent canonical Wnt/β-catenin signaling by stabilizing active cell surface WNT7, suggesting isoform-specific regulation of Wnt bioavailability. : Canonical Wnt/β-catenin signaling in brain endothelium is highly specialized and requires the WNT7-specific co-activators RECK and GPR124 in addition to the Wnt co-receptors FZD and LRP. Here, Vallon et al. demonstrate direct binding of WNT7 to RECK resulting in stabilization of active WNT7 and increased FZD:WNT7 complex formation. Keywords: Wnt signaling, endothelial cells, central nervous system, blood-brain barrier, RECK, WNT7, GPR124

Disruption of the blood-brain barrier (BBB) causes or contributes to neuronal dysfunction and several central nervous system (CNS) disorders. Wnt/β-catenin signaling is essential for maintaining the integrity of the adult BBB in physiological and pathological conditions, including stroke. However, how the impairment of the endothelial Wnt/β-catenin signaling results in BBB breakdown remains unclear. Furthermore, the individual contributions of different BBB permeability-inducing mechanisms, including intercellular junction damage, endothelial transcytosis, and fenestration, remains unexplored. Here, we induced β-catenin endothelial-specific conditional knockout (ECKO) in adult mice and determined its impact on BBB permeability and the underlying mechanism. β-catenin ECKO reduced the levels of active β-catenin and the mRNA levels of Wnt target genes in mice, indicating downregulation of endothelial Wnt/β-catenin signaling. β-catenin ECKO mice displayed severe and widespread leakage of plasma IgG and albumin into the cerebral cortex, which was absent in wild-type controls. Mechanistically, both the paracellular and transcellular transport routes were disrupted in β-catenin ECKO mice. First, β-catenin ECKO reduced the tight junction protein levels and disrupted the intercellular junction ultrastructure in the brain endothelium. Second, β-catenin ECKO substantially increased the number of endothelial vesicles and caveolae-mediated transcytosis through downregulating Mfsd2a and upregulating caveolin-1 expression. Interestingly, fenestration and upregulated expression of the fenestration marker Plvap were not observed in β-catenin ECKO mice. Overall, our study reveals that endothelial Wnt/β-catenin signaling maintains adult BBB integrity via regulating the paracellular as well as transcellular permeability. These findings may have broad applications in understanding and treatment of CNS disorders involving BBB disruption. [ABSTRACT FROM AUTHOR]

Choriocarcinoma is characterized by malignant proliferation and transformation of trophoblasts and is currently treated with systemic chemotherapeutic agents. The lack of specific targets for chemotherapeutic agents results in indiscriminate drug distribution. In our study, we aimed to delineate the mechanism by which G protein-coupled receptor 1 (GPR1) regulates the development of choriocarcinoma and thus investigated GPR1 as a prospective chemotherapeutic target. In this study, GPR1 expression levels were examined in several trophoblast cell lines. We found significantly higher GPR1 expression in choriocarcinoma cells (JEG3 and BeWo) than in normal trophoblast cells (HTR-8/SVneo). Additionally, we studied the role of GPR1 in choriocarcinoma in vitro and in vivo. GPR1 knockdown suppressed proliferation, invasion, and Akt and ERK phosphorylation in vitro and slowed tumor growth in vivo. Interestingly, GPR1 overexpression promoted increased proliferation, invasion, and Akt and ERK phosphorylation in vitro. Furthermore, we identified a specific GPR1-binding seven-amino acid peptide, LRH7- G3, that might also suppress choriocarcinoma in vitro and in vivo through phage display. Our study is the first to report that GPR1 may play a role in regulating choriocarcinoma progression through the Akt and ERK pathways. GPR1 could be a promising potential pharmaceutical target for choriocarcinoma. [ABSTRACT FROM AUTHOR]

Oligodendrocytesmyelinate axons in the central nervous system and develop fromoligodendrocyte precursor cells (OPCs) that must first migrate extensively during brain and spinal cord development.We showthat OPCs require the vasculature as a physical substrate for migration.We observed that OPCs of the embryonic mouse brain and spinal cord, as well as the human cortex, emerge from progenitor domains and associate with the abluminal endothelial surface of nearby blood vessels. Migrating OPCs crawl along and jump between vessels. OPC migration in vivo was disrupted in mice with defective vascular architecture but was normal in mice lacking pericytes. Thus, physical interactions with the vascular endothelium are required for OPC migration.We identifyWnt-Cxcr4 (chemokine receptor 4) signaling in regulation of OPC-endothelial interactions and propose that this signaling coordinates OPC migration with differentiation. [ABSTRACT FROM AUTHOR]