Blood-brain Barrier In Patients Research Articles

Familial Alzheimer’s Disease Mutation PSEN2 Exacerbates Toxoplasma gondii-mediated Human Blood-Brain Barrier Damage

Background and Hypothesis Toxoplasma gondii is an obligate intracellular parasite that infects one-third of the global population. T. gondii transmission to humans primarily occurs from the consumption of contaminated meats, water, or produce. Unfortunately, T. gondii will evade the host clearance, allowing it to cross the blood-brain barrier (BBB), infecting neurons where it transitions into slow-growing cysts, leading to a life-long chronic infection. Recently, studies have suggested that T. gondii infection may exacerbate the decline of cognitive function. The BBB is critical for restricting neurotoxic blood-derived products, leukocytes, and pathogens from entering the brain. Studies have shown that BBB dysfunction and damage to the barrier integrity may also contribute to cognitive impairment. Alzheimer’s disease (AD), the most common form of dementia, is a progressive neurodegenerative disease and its neuropathology is associated with b-amyloid plaques. Familial Alzheimer’s Disease is associated with the proteins, presenilin-1 and presenilin-2, encoded by PSEN1 and PSEN2. Mutations in these two genes contribute to early onset AD. Furthermore, dementia has been linked with an increased breakdown of the BBB. Therefore, we hypothesized that T. gondii infection will exacerbate barrier damage and dysfunction in brain microvascular endothelial cells (BMECs) containing familial AD mutations compared to healthy controls. Experimental Design To test our hypothesis, we infected human induced pluripotent stem cell (iPSC)-derived BMECs, which display near in vivo like BBB properties, containing the familial AD PSEN2 mutation or healthy controls with T. gondii. Results Using immunofluorescence and transendothelial electrical resistance, our results show that BMECs containing the PSEN2 mutation have a quicker onset of barrier damage, but we observed no difference in the loss of tight junctions ZO-1, Occludin, and Claudin-5 compared to healthy controls after infection. Potential Impact These data suggest that a T. gondii infection can exacerbate the breakdown of the BBB in patients with the PSEN2 mutation, worsening the prognosis of familial AD patients.

The Brain Kidney Axis Vascular Cross Talk

AbstractChronic kidney disease (CKD) is associated with cognitive impairment and dementia; 87% of patients on chronic dialysis have some degree of cognitive impairment. The prevalence of CKD increases with age and approximately 40% of persons aged >60 years have CKD. With increasing life expectancy, prevalence of both CKD and dementia are expected to increase.CKD and Alzheimer’s disease (AD) share common risk factors. Patients with CKD are older, and have multiple comorbidities such as hypertension, diabetes mellitus, dyslipidemia, metabolic syndrome, and obesity, making CKD a model for accelerated aging, inflammation, and vascular dysregulation. Inflammation and vascular dysregulation can disrupt blood brain barrier, decreased kidney function can influence amyloid clearance, an important AD biomarker. Patients with CKD have alterations in cerebral blood flow, brain white matter integrity, brain neurochemicals, and blood brain barrier permeability‐ findings that are similar to those seen in AD.We investigated brain alterations seen in CKD before and after successful kidney transplant and found reversibility of brain alterations, and improvement in cognitive function after kidney transplantation. Further, we examined whether the cognitive impairment in CKD is due to comorbidities such as hypertension or due to decreased kidney function. In addition, for the first time, we have shown evidence for disruption of blood brain barrier in patients with CKD. With the high prevalence of CKD in the older population, and the strong association between decreased glomerular filtration rate and cognitive impairment, understanding the mechanisms underlying cognitive impairment and developing strategies to mitigate the risks in the CKD population is important.The potential reversibility in brain alterations seen in CKD after a kidney transplant indicate an opportunity to develop strategies for management of cognitive impairment.

Enhanced VEGF secretion and blood-brain barrier disruption: Radiation-mediated inhibition of astrocyte autophagy via PI3K-AKT pathway activation.

Radiation-induced damage to the blood-brain barrier (BBB) is the recognized pathological basis of radiation-induced brain injury (RBI), a side effect of head and neck cancer treatments. There is currently a lack of therapeutic approaches for RBI due to the ambiguity of its underlying mechanisms. Therefore, it is essential to identify these mechanisms in order to prevent RBI or provide early interventions. One crucial factor contributing to BBB disruption is the radiation-induced activation of astrocytes and oversecretion of vascular endothelial growth factor (VEGF). Mechanistically, the PI3K-AKT pathway can inhibit cellular autophagy, leading to pathological cell aggregation. Moreover, it acts as an upstream pathway of VEGF. In this study, we observed the upregulation of the PI3K-AKT pathway in irradiated cultured astrocytes through bioinformatics analysis, we then validated these findings in animal brains and in vitro astrocytes following radiation exposure. Additionally, we also found the inhibition of autophagy and the oversecretion of VEGF in irradiated astrocytes. By inhibiting the PI3K-AKT pathway or promoting cellular autophagy, we observed a significant amelioration of the inhibitory effect on autophagy, leading to reductions in VEGF oversecretion and BBB disruption. In conclusion, our study suggests that radiation can inhibit autophagy and promote VEGF oversecretion by upregulating the PI3K-AKT pathway in astrocytes. Blocking the PI3K pathway can alleviate both of these effects, thereby mitigating damage to the BBB in patients undergoing radiation treatment.

Establishment and Validation of a New Co-Culture for the Evaluation of the Permeability through the Blood-Brain Barrier in Patients with Glioblastoma.

Currently, the mechanisms involved in drug access to the central nervous system (CNS) are not completely elucidated, and research efforts to understand the behaviour of the therapeutic agents to access the blood-brain barrier continue with the utmost importance. The aim of this work was the creation and validation of a new in vitro model capable of predicting the in vivo permeability across the blood-brain barrier in the presence of glioblastoma. The selected in vitro method was a cell co-culture model of epithelial cell lines (MDCK and MDCK-MDR1) with a glioblastoma cell line (U87-MG). Several drugs were tested (letrozole, gemcitabine, methotrexate and ganciclovir). Comparison of the proposed in vitro model, MDCK and MDCK-MDR1 co-cultured with U87-MG, and in vivo studies showed a great predictability for each cell line, with R2 values of 0.8917 and 0.8296, respectively. Therefore, both cells lines (MDCK and MDCK-MDR1) are valid for predicting the access of drugs to the CNS in the presence of glioblastoma.

Abstract 2788: Extracellular vesicles as a pharmacodynamic reporter in glioblastoma

Abstract Glioblastoma (GBM), a lethal astrocytic brain tumor, has limited available treatment options. A major hindrance to the progress of new therapies is the selectivity of the blood brain barrier (BBB) which limits drug access to the tumor. Further, there are currently no minimally-invasive tests that can quickly and accurately determine whether novel therapeutics have crossed the BBB during clinical trials. Therefore, development of a non-invasive test that can identify drug delivery and target engagement in GBM represents an opportunity to enhance knowledge during early phase trials of a new compound’s pharmacological suitability and potential efficacy. This study proposes that cargo contained in GBM-derived extracellular vesicles (EVs), which are small membrane-bound particles released from cells, may serve as one such pharmacodynamic reporter. We analyzed RNA-seq data for EVs isolated from two GBM patient-derived xenograft models grown as short-term in vitro cultures, GBM10 and GBM120, following treatment with either temozolomide (TMZ) or pevonedistat (MLN). We assessed whether EV RNA payloads vary with different drug concentrations (EC50 vs EC80) and at different time points (4hr vs 24hr) post treatment. In the samples treated with MLN, a few long non-coding RNAs are commonly upregulated across the different time points and two models. Under different TMZ concentrations, differentially expressed genes are overrepresented in biological processes such as cytoplasmic translation and cellular macromolecule biosynthesis. We also found a negative correlation between the TMZ concentration and Y RNA expression level, which are functionally involved with DNA replication. Additionally, using CIRI2, we predicted the amount of circular RNAs in the EV cargo; we found that the ratio of circular RNAs to their linear counterparts (CLR) varies under different treatments. In GBM10, the percentage of circRNA with CLR > 1 decreases with increasing drug effect. Thus, our preliminary results indicate that EV cargo post-treatment may be a novel pharmacodynamic reporter in GBM. To apply such an assessment to patients, we have simultaneously pursued the development of an immunoprecipitation (IP) approach to enrich GBM-derived EVs that can then undergo cargo profiling. Potential biomarkers were screened across isolated GBM EVs from in vitro supernatant by western blot and ExoView analysis. B7H3 has emerged as a lead candidate for GBM-EV enrichment. To validate the ability of EV cargo to reflect drug distribution across the BBB in patients, current efforts are focused on applying IP enrichment of GBM-EVs in longitudinally-acquired cerebrospinal fluid samples from patients during their disease course. Overall, we anticipate that the results of this study will lead to development of a clinical test that reflects BBB penetration and tumor response, which will likely aid in novel drug development efforts. Citation Format: Valerie DeLuca, Nanyun Tang, Yue Hao, Anjali Raju, Charles Shaffer, Cecile Riviere-Cazaux, Terry C. Burns, Jann Sarkaria, Ian Parney, Patrick Pirrotte, Kendall Van Keuren-Jensen, Michael E. Berens. Extracellular vesicles as a pharmacodynamic reporter in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2788.

Single-cell transcriptomics reveals the interaction between peripheral CD4+ CTLs and mesencephalic endothelial cells mediated by IFNG in Parkinson's disease

Parkinson's disease (PD) is characterized by dopaminergic neurons degeneration in the substantia nigra pars compacta. Increasing evidence indicates that peripheral CD4+ T cells, a vital pathological component of PD, have been implicated in systemic inflammation activation, blood-brain barrier (BBB) dysfunction, central nervous system infiltration, and consequent neurons degeneration. However, there is no consensus on CD4+ T cell types' exact phenotypic characteristics in systemic inflammation and the mechanism of CD4+ T cells traffic into the BBB in patients with PD. In this study, we employed single-cell RNA sequencing (scRNA-seq) to elucidate the potential mechanism of T cells on the breakdown of BBB. The PD-associated Cytotoxic CD4+ T cells (CD4+ CTLs) were characterized by a significant increase in proportion as well as enhancement of interferon-gamma (IFNG) response and cell adhesion. Meanwhile, TBX21, IRF1 and NFATC2, identified as the key transcription factors in effector CD4+ T cells differentiation, induced overexpression of target genes-IFNG in CD4+ CTLs. Interestingly, endothelial cells (ECs) in PD patients were discovered to be more responsive to IFNG than other cell types of midbrain. Furthermore, the cell-cell communication analysis between CD4+ T cells and midbrain cells identified IFNG/IFNGR1 and SPP1/ITGB1 as the ligand-receptor pairs to mediate CD4+ CTLs' infiltration into the central nervous system (CNS) through the weakened ECs' tight junction. Together, these results suggested that PD-specific peripheral CD4+ CTLs might influence BBB function by migrating to mesencephalic endothelial cells (ECs) and activating the IFNG response in ECs.

Blood-Brain Barrier-Associated Proteins Are Elevated in Serum of Epilepsy Patients.

Blood-brain barrier (BBB) dysfunction emerges as one of the mechanisms underlying the induction of seizures and epileptogenesis. There is growing evidence that seizures also affect BBB, yet only scarce data is available regarding serum levels of BBB-associated proteins in chronic epilepsy. In this study, we aimed to assess serum levels of molecules associated with BBB in patients with epilepsy in the interictal period. Serum levels of MMP-9, MMP-2, TIMP-1, TIMP-2, S100B, CCL-2, ICAM-1, P-selectin, and TSP-2 were examined in a group of 100 patients who were seizure-free for a minimum of seven days and analyzed by ELISA. The results were compared with an age- and sex-matched control group. Serum levels of MMP-9, MMP-2, TIMP-1, TIMP-2 and S100B were higher in patients with epilepsy in comparison to control group (p < 0.0001; <0.0001; 0.001; <0.0001; <0.0001, respectively). Levels of CCL-2, ICAM-1, P-selectin and TSP-2 did not differ between the two groups. Serum levels of MMP-9, MMP-2, TIMP-1, TIMP-2 and S100B are elevated in patients with epilepsy in the interictal period, which suggests chronic processes of BBB disruption and restoration. The pathological process initiating epilepsy, in addition to seizures, is probably the factor contributing to the elevation of serum levels of the examined molecules.

The pathogenic role of lupus-specific autoantibodies and Interleukin-6 on demyelination of the brainstem and spinal cord in systemic lupus erythematosus.

Demyelinating syndromes that result in brainstem and/or spinal cord lesions similar to those observed in neuromyelitis optica spectrum disorder (NMOSD) as neuropsychiatric syndromes in systemic lupus erythematosus (NPSLE) occasionally develop in patients with SLE. Cerebrospinal fluid (CSF) interleukin (IL)-6 is a known biomarker for NMOSD; however, its application in patients with SLE with brainstem and/or spinal cord lesions is unknown. Additionally, the breakdown of blood-brain barrier (BBB) integrity by autoantibodies is another mechanism of NMOSD; however, it is not elucidated in SLE. Therefore, this study was designed to clarify the use of CSF IL-6 and investigate whether autoantibodies contribute to BBB breaches and the development of brainstem and/or spinal cord lesions. Data from patients with NPSLE who had NMOSD-like demyelinating lesions in the central nervous system (CNS), including brainstem and/or spinal cord lesions, were retrospectively analyzed. We retrospectively investigated the interval changes in CSF IL-6 and clinical and serological factors related to BBB permeability using CSF/serum albumin ratio (QAlb). Twelve patients with NPSLE who had demyelinating lesions in the brainstem and/or spinal cord were recruited. Before treatment, CSF IL-6 levels were 29.1pg/mL and significantly decreased to 3.8pg/mL by treatment (p = 0.008). Before treatment, CSF IL-6 was significantly correlated with the anti-dsDNA antibody titer (p = 0.027). Furthermore, before treatment, QAlb was significantly correlated with the serum anti-Smith antibody titer. In patients with atypical NMOSD who had specific lesions defined in the NMOSD diagnostic criteria but were negative for antiaquaporin four antibody, a significant correlation was observed between the serum anti-Smith antibody titer and CSF IL-6 (p = 0.025) and QAlb (p = 0.033) values before treatment. CSF IL-6 could be a surrogating marker for disease activity, and serum anti-Smith antibody permeabilizes the BBB in patients with NPSLE, supporting the development of NMOSD-like CNS lesions.

Single-nucleus RNA sequencing of midbrain blood-brain barrier cells in schizophrenia reveals subtle transcriptional changes with overall preservation of cellular proportions and phenotypes

The midbrain is an extensively studied brain region in schizophrenia, in view of its reported dopamine pathophysiology and neuroimmune changes associated with this disease. Besides the dopaminergic system, the midbrain contains other cell types that may be involved in schizophrenia pathophysiology. The neurovascular hypothesis of schizophrenia postulates that both the neurovasculature structure and the functioning of the blood-brain barrier (BBB) are compromised in schizophrenia. In the present study, potential alteration in the BBB of patients with schizophrenia was investigated by single-nucleus RNA sequencing of post-mortem midbrain tissue (15 schizophrenia cases and 14 matched controls). We did not identify changes in the relative abundance of the major BBB cell types, nor in the sub-populations, associated with schizophrenia. However, we identified 14 differentially expressed genes in the cells of the BBB in schizophrenia as compared to controls, including genes that have previously been related to schizophrenia, such as FOXP2 and PDE4D. These transcriptional changes were limited to the ependymal cells and pericytes, suggesting that the cells of the BBB are not broadly affected in schizophrenia.

Activation of Wnt/β-catenin pathway mitigates blood-brain barrier dysfunction in Alzheimer's disease.

Alzheimer's disease is a neurodegenerative disorder that causes age-dependent neurological and cognitive declines. The treatments for Alzheimer's disease pose a significant challenge, because the mechanisms of disease are not being fully understood. Malfunction of the blood-brain barrier is increasingly recognized as a major contributor to the pathophysiology of Alzheimer's disease, especially at the early stages of the disease. However, the underlying mechanisms remain poorly characterized, while few molecules can directly target and improve blood-brain barrier function in the context of Alzheimer's disease. Here, we showed dysfunctional blood-brain barrier in patients with Alzheimer's disease reflected by perivascular accumulation of blood-derived fibrinogen in the hippocampus and cortex, accompanied by decreased tight junction proteins Claudin-5 and glucose transporter Glut-1 in the brain endothelial cells. In the APPswe/PS1dE9 (APP/PS1) mouse model of Alzheimer's disease, blood-brain barrier dysfunction started at 4 months of age and became severe at 9 months of age. In the cerebral microvessels of APP/PS1 mice and amyloid-β-treated brain endothelial cells, we found suppressed Wnt/β-catenin signalling triggered by an increase of GSK3β activation, but not an inhibition of the AKT pathway or switching to the Wnt/planar cell polarity pathway. Furthermore, using our newly developed optogenetic tool for controlled regulation of LRP6 (upstream regulator of the Wnt signalling) to activate Wnt/β-catenin pathway, blood-brain barrier malfunction was restored by preventing amyloid-β-induced brain endothelial cells impairments and promoting the barrier repair. In conclusion, targeting LRP6 in the Wnt/β-catenin pathway in the brain endothelium can alleviate blood-brain barrier malfunction induced by amyloid-β, which may be a potential treatment strategy for Alzheimer's disease.

Clinical Features and Potential Mechanisms Relating Neuropathological Biomarkers and Blood-Brain Barrier in Patients With Alzheimer's Disease and Hearing Loss.

BackgroundThe aim of this study was to explore clinical features and potential mechanisms relating neuropathological biomarkers and blood-brain barrier (BBB) in Alzheimer’s disease (AD) and hearing loss (HL).Materials and MethodsA total of 65 patients with AD were recruited and auditory function was assessed by threshold of pure tone audiometry (PTA). Patients were divided into AD with HL (AD-HL) and AD with no HL (AD-nHL) groups based on the standard of World Health Organization. Clinical symptoms were assessed by multiple rating scales. The levels of neuropathological biomarkers of β amyloid1-42 (Aβ1–42) and multiple phosphorylated tau (P-tau), and BBB factors of matrix metalloproteinases (MMPs), receptor of advanced glycation end products, glial fibrillary acidic protein, and low-density lipoprotein receptor related protein 1 were measured.Results(1) Compared with AD-nHL group, AD-HL group had significantly impaired overall cognitive function and cognitive domains of memory, language, attention, execution, and activities of daily living (ADL) reflected by the scores of rating scales (P < 0.05). PTA threshold was significantly correlated with the impairments of overall cognitive function and cognitive domains of memory and language, and ADL in patients with AD (P < 0.05). (2) P-tau (S199) level was significantly increased in CSF from AD-HL group (P < 0.05), and was significantly and positively correlated with PTA threshold in patients with AD. (3) MMP-3 level was significantly elevated in CSF from AD-HL group (P < 0.05), and was significantly and positively correlated with PTA threshold in patients with AD (P < 0.05). (4) In AD-HL group, P-tau (S199) level was significantly and positively correlated with the levels of MMP-2 and MMP-3 in CSF (P < 0.05).ConclusionAD-HL patients have severely compromised overall cognitive function, multiple cognitive domains, and ADL. The potential mechanisms of AD-HL involve elevations of AD neuropathological biomarker of P-tau (S199) and BBB factor of MMP-3, and close correlations between P-tau (S199) and MMP-2/MMP-3 in CSF. Findings from this investigation highly suggest significance of early evaluation of HL for delaying AD progression, and indicate new directions of drug development by inhibiting neuropathological biomarkers of AD and protecting BBB.

Реамберин у комплексі оптимізації та диференціації стратегії інтенсивної терапії вторинних гнійних менінгоенцефалітів

Стаття присвячена питанням покращання діагностики, застосування методик оцінки тяжкості стану хворих при надходженні у відділення інтенсивної терапії, у динаміці спостереження за ними, оптимізації інтенсивної терапії (ІТ) вторинного гнійного менінгоенцефаліту (ВГМЕ). Загальна схема відбору пацієнтів, їх рандомізації, включення в дослідження й аналіз можуть бути подані в такий спосіб. Пацієнти з підтвердженим ВГМЕ методом рандомізації з урахуванням тяжкості стану та варіанту ІТ були розподілені на 2 групи. У I групу увійшли 22 пацієнти, котрим проводилася базисна ІТ із позицій доказової медицини відповідно до міжнародних рекомендацій Surviving Sepsis Campaign: International guidelines for management of severe sepsis and septiс shock 2012, що доповнювалася включенням дексаметазону. У II групу увійшов 21 пацієнт, у яких ІТ, що проводилась у I групі, доповнювалась в/в введенням розчину реамберин. На початку дослідження не виявлено вірогідних відмінностей між групами за статтю, віком, локалізацією септичного вогнища, частотою реєстрації 4 ознак синдрому системної запальної відповіді, позитивних результатів бактеріологічних посівів ліквору та матеріалів із первинного вогнища, тобто вибірки були порівняними за цими ознаками. У цей же час серед пацієнтів II групи було в 2,8 раза більше хворих із рівнем свідомості «сопор» або «кома I ступеня» (76,2 % проти 27,2 %; р &lt; 0,001). Несприятливий прогноз (центральний перфузійний тиск &lt; 50 мм рт.ст.) при надходженні до стаціонару мали 22,7 % хворих із I групи і 28,6 % — із II (р &gt; 0,60). Незважаючи на початково більш тяжкий стан хворих із ВГМЕ в II групі, додавання до базисної терапії в/в введення розчину реамберин сприяло тому, що санація ліквору в II групі проходила більш плавно, без вторинного сплеску цитозу, характерного для I групи на 5-ту добу дослідження. Установлено, що в I групі С-реактивний білок у лікворі зникав до 3-ї доби дослідження, з’являвся на 5-ту добу і був відсутнім до 7-ї доби дослідження. У II групі наявність С-реактивного білка було зафіксовано лише на початку і 1-шу добу дослідження, що свідчить про більш стійкий характер відновлення функціонального стану гематоенцефалічного бар’єра в II групі, без вторинного (повторного) його прориву. Оцінка ефективності ІТ на 28-му добу дослідження показала, що відмічалось зменшення когнітивних дисфункцій у I групі на 28,4 %, у II — на 37,7 %; органних дисфункцій у I групі — з 76,3 до 43,8 %; у II — з 88,7 до 36,9 %. Показники істинної летальності становили 27,27 і 23,81 % (р &gt; 0,90) відповідно. Зниження прогнозованої летальності в I групі становило 4,73 %, у II — 16,19 %.

Oral Ursodeoxycholic acid crosses the blood brain barrier in patients with retinal detachment and protects against retinal degeneration in an ex vivo model

AbstractPurposeThe neuroprotective properties of hydrophilic bile acids are recognized but whether their oral administration can benefit to patients with retinal diseases is unknown. Rhegmatogenous retinal detachment (RD) is a threatening visual condition and a human disease model for retinal degenerations. Despite surgical reattachment, vision does not fully recover, due to subretinal fluid (SFR) and photoreceptor cell death, through mechanisms that recapitulate those of retinal degenerative diseases. We have measured the ocular concentration of Ursodeoxycholic acid (UDCA) administered orally to patients with RD. We then tested the effects and mechanisms of UDCA, at concentrations found in patient’s eyes, in RD models. Finally, we analyzed the neuroprotective effects of ocular fluids from treated patients.Methods26 patients with RD were included. 21 patients received UDCA before surgery. Ocular fluids samples were collected and bile acids were measured. Rat retinal explants and WERI‐Rb‐1 human cone cell line were exposed to albumin or patient’s SRF ± UDCA. Cell death markers and transcriptome were analyzed.ResultsUDCA was detected in ocular media after oral administration and its level correlated with protein concentration in SRF and extension of RD. At 6 months after surgery, visual recovery was superior in patients who had higher UDCA ocular levels.UDCA levels measured in human ocular media, protected photoreceptors from apoptosis and necrosis in rats retinal explants exposed to albumin and UDCA protected WERI‐Rb‐1 cells from albumin‐induced death. Cell death was reduced in retinal explants exposed to SRF collected from UDCA‐treated patients as compared to SRF from controls. UDCA effects resulted from the up‐regulation of anti‐apoptotic, anti‐oxidant and anti‐inflammatory genes.ConclusionsOral UDCA reaches neuroprotective concentrations in patients with RD, showing its potential as an adjuvant to surgery but also in other retinal degenerative diseases.

Alzheimer's disease with sleep insufficiency: a cross-sectional study on correlations among clinical characteristics, orexin, its receptors, and the blood-brain barrier.

Previous studies have shown that reduced sleep duration, sleep fragmentation, and decreased sleep quality in patients with Alzheimer's disease are related to dysfunction in orexin signaling. At the same time, blood-brain barrier disruption is considered an early biomarker of Alzheimer's disease. However, currently no report has examined how changes in orexin signaling relate to changes in the blood-brain barrier of patients who have Alzheimer's disease with sleep insufficiency. This cross-sectional study included 50 patients with Alzheimer's disease who received treatment in 2019 at Beijing Tiantan Hospital. Patients were divided into two groups: those with insufficient sleep (sleep duration ≤ 6 hours, n = 19, age 61.58 ± 8.54 years, 10 men) and those with normal sleep durations (sleep duration > 6 hours, n = 31, age 63.19 ± 10.09 years, 18 men). Demographic variables were collected to evaluate cognitive function, neuropsychiatric symptoms, and activities of daily living. The levels of orexin, its receptor proteins, and several blood-brain barrier factors were measured in cerebrospinal fluid. Sleep insufficiency was associated with impaired overall cognitive function that spanned multiple cognitive domains. Furthermore, levels of orexin and its receptors were upregulated in the cerebrospinal fluid, and the blood-brain barrier was destroyed. Both these events precipitated each other and accelerated the progression of Alzheimer's disease. These findings describe the clinical characteristics and potential mechanism underlying Alzheimer's disease accompanied by sleep deprivation. Inhibiting the upregulation of elements within the orexin system or preventing the breakdown of the blood-brain barrier could thus be targets for treating Alzheimer's disease.

Inhibition of Aryl Hydrocarbon Receptor Attenuates Hyperglycemia-Induced Hematoma Expansion in an Intracerebral Hemorrhage Mouse Model.

BackgroundHyperglycemia is associated with greater hematoma expansion (HE) and worse clinical prognosis after intracerebral hemorrhage (ICH). However, the clinical benefits of intensive glucose normalization remain controversial, and there are no approved therapies for reducing HE. The aryl hydrocarbon receptor (AHR) has been shown to participate in hyperglycemia‐induced blood–brain barrier (BBB) dysfunction and brain injury after stroke. Herein, we investigated the role of AHR in hyperglycemia‐induced HE in a male mouse model of ICH.Methods and ResultsCD1 mice (n=387) were used in this study. Mice were subjected to ICH by collagenase injection. Fifty percent dextrose was injected intraperitoneally 3 hours after ICH. AHR knockout clustered regularly interspaced short palindromic repeat was administered intracerebroventricularly to evaluate the role of AHR after ICH. A selective AHR inhibitor, 6,2′,4′‐trimethoxyflavone, was administered intraperitoneally 2 hours or 6 hours after ICH for outcome study. To evaluate the effect of AHR on HE, 3‐methylcholanthrene, an AHR agonist, was injected intraperitoneally 2 hours after ICH. The results showed hyperglycemic ICH upregulated AHR accompanied by greater HE. AHR inhibition provided neurological benefits by restricting HE and preserving BBB function after hyperglycemic ICH. In vivo knockdown of AHR further limited HE and enhanced the BBB integrity. Hyperglycemia directly activated AHR as a physiological stimulus in vivo. The thrombospondin‐1/transforming growth factor‐β/vascular endothelial growth factor axis partly participated in AHR signaling after ICH, which inhibited the expressions of BBB‐related proteins, ZO‐1 and Claudin‐5.ConclusionsAHR may serve as a potential therapeutic target to attenuate hyperglycemia‐induced hematoma expansion and to preserve the BBB in patients with ICH.

Free Immunoglobulin Light Chains in Patients with Tick-Borne Encephalitis: Before and after Treatment.

Background: Tick-borne encephalitis (TBE) is inflammation of the central nervous system (CNS) caused by a viral infection which may be associated with increased synthesis of immunoglobulins. It can lead to inter alia, breakdown of the blood-brain barrier (BBB), or even death and, unfortunately, treatment is only symptomatic. Therefore, the aim of the present study was assessment of the concentrations of free light chains (FLC) kappa (κ) and lambda (λ in the cerebrospinal fluid (CSF) and serum of patients with TBE. Methods: A total of 58 cerebrospinal fluid and serum sample pairs were analyzed. Samples were collected from patients with TBE before and after treatment. FLC were measured using the turbidimetric method. The values of κIgG-index, λIgG-index, κFLC-index and λFLC-index were calculated using relevant formulas. Results: Pre-treatment serum λFLC concentrations were higher in comparison to post-treatment levels. Moreover, it was observed that CSF λFLC, TBEV IgM, TBEV IgG, and serum TBEV IgG, as well as the values of λFLC-index, κFLC-index, and λIgG-index were elevated after treatment. In the total study group, the concentrations of CSF κFLC and λFLC, and values of four indexes: κFLC-index, λFLC-index, κIgG-index, and λIgG-index correlated with each other and with CSF TBEV IgM and IgG antibodies. The CSF level of TBEV IgG was also associated with serum IgG TBEV and CSF IgM TBEV antibodies. Additionally, serum κFLC correlated with serum and CSF λFLC. Conclusion: This is the first study that demonstrates statistically significant differences in serum and CSF λFLC, as well as in the calculated values of three algorithms: λIgG-index, κFLC-index, and λIgG-index prior to and following treatment of TBE. Our findings may indicate that these differences reflect the intrathecal synthesis of immunoglobulins and increased permeability of BBB in patients with TBE. Moreover, it could provide the basis for developing new therapeutic strategies.

A Higher Dose of Dasatinib May Increase the Possibility of Crossing the Blood–brain Barrier in the Treatment of Patients With Philadelphia Chromosome–positive Acute Lymphoblastic Leukemia

Dasatinib is a second-generation tyrosine kinase inhibitor with higher central nervous system (CNS) penetration compared with imatinib and nilotinib in in vitro studies. However, limited clinical data are available regarding the dosage and CNS penetration of dasatinib. The purpose of this study was to investigate the actual ability of dasatinib to cross the blood-brain barrier in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). Plasma and cerebrospinal fluid (CSF) samples collected from Ph+ ALL patients treated with dasatinib were analyzed by using an LC-MS/MS assay. Orally administered dasatinib 100 mg once daily was well absorbed by the patient but penetrated poorly into the CSF. The use of a higher drug dosage (140 mg/d) may increase systemic drug exposure and enhance the penetration of dasatinib into the CSF. Based on this study, the use of a higher dosage of dasatinib (140 mg/d) is recommended in patients at high risk of CNS relapse or patients who need treatment for CNS leukemia. ClinicalTrials.gov identifier: NCT02523976.

Drug-Resistant Temporal Lobe Epilepsy Alters the Expression and Functional Coupling to Gαi/o Proteins of CB1 and CB2 Receptors in the Microvasculature of the Human Brain.

Cannabinoid receptors 1 and 2 (CB1 and CB2, respectively) play an important role in maintaining the integrity of the blood–brain barrier (BBB). On the other hand, BBB dysfunction is a common feature in drug-resistant epilepsy. The focus of the present study was to characterize protein expression levels and Gαi/o protein-induced activation by CB1 and CB2 receptors in the microvascular endothelial cells (MECs) isolated from the brain of patients with drug-resistant mesial temporal lobe epilepsy (DR-MTLE). MECs were isolated from the hippocampus and temporal neocortex of 12 patients with DR-MTLE and 12 non-epileptic autopsies. Immunofluorescence experiments were carried out to determine the localization of CB1 and CB2 receptors in the different cell elements of MECs. Protein expression levels of CB1 and CB2 receptors were determined by Western blot experiments. [35S]-GTPγS binding assay was used to evaluate the Gαi/o protein activation induced by specific agonists. Immunofluorescent double-labeling showed that CB1 and CB2 receptors colocalize with tight junction proteins (claudin-5, occludin, and zonula occludens-1), glial fibrillary acidic protein and platelet-derived growth factor receptor-β. These results support that CB1 and CB2 receptors are expressed in the human isolated microvessels fragments consisting of MECs, astrocyte end feet, and pericytes. The hippocampal microvasculature of patients with DR-MTLE presented lower protein expression of CB1 and CB2 receptors (66 and 43%, respectively; p < 0.001). However, its Gαi/o protein activation was with high efficiency (CB1, 251%, p < 0.0008; CB2, 255%, p < 0.0001). Microvasculature of temporal neocortex presented protein overexpression of CB1 and CB2 receptors (35 and 41%, respectively; p < 0.01). Their coupled Gαi/o protein activation was with higher efficiency for CB1 receptors (103%, p < 0.006), but lower potency (p < 0.004) for CB2 receptors. The present study revealed opposite changes in the protein expression of CB1 and CB2 receptors when hippocampus (diminished expression of CB1 and CB2) and temporal neocortex (increased expression of CB1 and CB2) were compared. However, the exposure to specific CB1 and CB2 agonists results in high efficiency for activation of coupled Gαi/o proteins in the brain microvasculature of patients with DR-MTLE. CB1 and CB2 receptors with high efficiency could represent a therapeutic target to maintain the integrity of the BBB in patients with DR-MTLE.

Mental disorders and the state of the blood-brain barrier in patients with the new coronavirus infection

Mental disorders and the state of the blood-brain barrier in patients with the new coronavirus infection

Dynamics of neurospecific enolase as a leading marker in determining the functional state of the blood-brain barrier in patients with metabolic coma

Annotation. Determining the pathogenetic mechanism of disturbance of consciousness, coma, at the stage of admission of the patient to the intensive care unit is an important point in determining the features of the algorithm of treatment of such patients. The aim of this study was to determine the mechanisms of the primary cause of loss of consciousness (coma) in the acute period of its course and to assess the effectiveness of pathogenetically sound intensive care since the patient's admission to the clinic. We examined 60 patients with coma of neurotropic metabolic (secondary) origin, who were additionally prescribed substances with antioxidant, vasoprotective and energy-protective effects in the algorithm of intensive care. Mean normal values of neurospecific enolase levels were obtained in 20 volunteers. The functional state of the blood-brain barrier was determined on the 1st, 3rd and 10th day of treatment. Ceruloplasmin solution and D-fructose-1,6-diphosphate sodium salt were found to be pathogenetically significant in determining the effects of treatment in patients with metabolic coma.