scholarly journals Towards Deep Neural Network Models for the Prediction of the Blood–Brain Barrier Permeability for Diverse Organic Compounds

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5901
Author(s):  
Eugene V. Radchenko ◽  
Alina S. Dyabina ◽  
Vladimir A. Palyulin
Keyword(s):  
Neural Network ◽  
Organic Compounds ◽  
Blood Brain Barrier ◽  
Structural Characteristics ◽  
External Validation ◽  
Brain Barrier ◽  
Full Potential ◽  
Neural Network Models ◽  
Blood Brain ◽  
Bbb Permeability

Permeation through the blood–brain barrier (BBB) is among the most important processes controlling the pharmacokinetic properties of drugs and other bioactive compounds. Using the fragmental (substructural) descriptors representing the occurrence number of various substructures, as well as the artificial neural network approach and the double cross-validation procedure, we have developed a predictive in silico LogBB model based on an extensive and verified dataset (529 compounds), which is applicable to diverse drugs and drug-like compounds. The model has good predictivity parameters (Q2=0.815, RMSEcv=0.318) that are similar to or better than those of the most reliable models available in the literature. Larger datasets, and perhaps more sophisticated network architectures, are required to realize the full potential of deep neural networks. The analysis of fragment contributions reveals patterns of influence consistent with the known concepts of structural characteristics that affect the BBB permeability of organic compounds. The external validation of the model confirms good agreement between the predicted and experimental LogBB values for most of the compounds. The model enables the evaluation and optimization of the BBB permeability of potential neuroactive agents and other drug compounds.

scholarly journals Quantum Artificial Neural Network Approach to Derive a Highly Predictive 3D-QSAR Model for Blood–Brain Barrier Passage

2021 ◽  
Vol 22 (20) ◽  
pp. 10995
Author(s):  
Taeho Kim ◽  
Byoung Hoon You ◽  
Songhee Han ◽  
Ho Chul Shin ◽  
Kee-Choo Chung ◽  
...  
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Blood Brain Barrier ◽  
3D Qsar ◽  
Qsar Model ◽  
Brain Barrier ◽  
Quantum Mechanical ◽  
Blood Brain ◽  
Artificial Neural ◽  
Bbb Permeability

A successful passage of the blood–brain barrier (BBB) is an essential prerequisite for the drug molecules designed to act on the central nervous system. The logarithm of blood–brain partitioning (LogBB) has served as an effective index of molecular BBB permeability. Using the three-dimensional (3D) distribution of the molecular electrostatic potential (ESP) as the numerical descriptor, a quantitative structure-activity relationship (QSAR) model termed AlphaQ was derived to predict the molecular LogBB values. To obtain the optimal atomic coordinates of the molecules under investigation, the pairwise 3D structural alignments were conducted in such a way to maximize the quantum mechanical cross correlation between the template and a target molecule. This alignment method has the advantage over the conventional atom-by-atom matching protocol in that the structurally diverse molecules can be analyzed as rigorously as the chemical derivatives with the same scaffold. The inaccuracy problem in the 3D structural alignment was alleviated in a large part by categorizing the molecules into the eight subsets according to the molecular weight. By applying the artificial neural network algorithm to associate the fully quantum mechanical ESP descriptors with the extensive experimental LogBB data, a highly predictive 3D-QSAR model was derived for each molecular subset with a squared correlation coefficient larger than 0.8. Due to the simplicity in model building and the high predictability, AlphaQ is anticipated to serve as an effective computational screening tool for molecular BBB permeability.

scholarly journals Dual Roles of Astrocyte-Derived Factors in Regulation of Blood-Brain Barrier Function after Brain Damage

2019 ◽  
Vol 20 (3) ◽  
pp. 571 ◽  
Author(s):  
Shotaro Michinaga ◽  
Yutaka Koyama
Keyword(s):  
Brain Damage ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Blood Brain ◽  
Secondary Damage ◽  
The Central Nervous System ◽  
Bbb Permeability ◽  
Novel Therapeutic Strategies ◽  
Glial Derived Neurotrophic Factor ◽  
Endothelial Growth Factors

The blood-brain barrier (BBB) is a major functional barrier in the central nervous system (CNS), and inhibits the extravasation of intravascular contents and transports various essential nutrients between the blood and the brain. After brain damage by traumatic brain injury, cerebral ischemia and several other CNS disorders, the functions of the BBB are disrupted, resulting in severe secondary damage including brain edema and inflammatory injury. Therefore, BBB protection and recovery are considered novel therapeutic strategies for reducing brain damage. Emerging evidence suggests key roles of astrocyte-derived factors in BBB disruption and recovery after brain damage. The astrocyte-derived vascular permeability factors include vascular endothelial growth factors, matrix metalloproteinases, nitric oxide, glutamate and endothelin-1, which enhance BBB permeability leading to BBB disruption. By contrast, the astrocyte-derived protective factors include angiopoietin-1, sonic hedgehog, glial-derived neurotrophic factor, retinoic acid and insulin-like growth factor-1 and apolipoprotein E which attenuate BBB permeability resulting in recovery of BBB function. In this review, the roles of these astrocyte-derived factors in BBB function are summarized, and their significance as therapeutic targets for BBB protection and recovery after brain damage are discussed.

scholarly journals Pseudogene ACTBP2 increases blood–brain barrier permeability by promoting KHDRBS2 transcription through recruitment of KMT2D/WDR5 in Aβ1–42 microenvironment

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Qianshuo Liu ◽  
Xiaobai Liu ◽  
Defeng Zhao ◽  
Xuelei Ruan ◽  
Rui Su ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Vital Role ◽  
Brain Barrier ◽  
Blood Brain ◽  
Bbb Permeability ◽  
Novel Target ◽  
And Function

AbstractThe blood–brain barrier (BBB) has a vital role in maintaining the homeostasis of the central nervous system (CNS). Changes in the structure and function of BBB can accelerate Alzheimer’s disease (AD) development. β-Amyloid (Aβ) deposition is the major pathological event of AD. We elucidated the function and possible molecular mechanisms of the effect of pseudogene ACTBP2 on the permeability of BBB in Aβ1–42 microenvironment. BBB model treated with Aβ1–42 for 48 h were used to simulate Aβ-mediated BBB dysfunction in AD. We proved that pseudogene ACTBP2, RNA-binding protein KHDRBS2, and transcription factor HEY2 are highly expressed in ECs that were obtained in a BBB model in vitro in Aβ1–42 microenvironment. In Aβ1–42-incubated ECs, ACTBP2 recruits methyltransferases KMT2D and WDR5, binds to KHDRBS2 promoter, and promotes KHDRBS2 transcription. The interaction of KHDRBS2 with the 3′UTR of HEY2 mRNA increases the stability of HEY2 and promotes its expression. HEY2 increases BBB permeability in Aβ1–42 microenvironment by transcriptionally inhibiting the expression of ZO-1, occludin, and claudin-5. We confirmed that knocking down of Khdrbs2 or Hey2 increased the expression levels of ZO-1, occludin, and claudin-5 in APP/PS1 mice brain microvessels. ACTBP2/KHDRBS2/HEY2 axis has a crucial role in the regulation of BBB permeability in Aβ1–42 microenvironment, which may provide a novel target for the therapy of AD.

scholarly journals Early Appearance of Activated Matrix Metalloproteinase-9 after Focal Cerebral Ischemia in Mice: A Possible Role in Blood—Brain Barrier Dysfunction

1999 ◽  
Vol 19 (9) ◽  
pp. 1020-1028 ◽  
Author(s):  
Yvan Gasche ◽  
Miki Fujimura ◽  
Yuiko Morita-Fujimura ◽  
Jean-Christophe Copin ◽  
Makoto Kawase ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Blood Brain Barrier ◽  
Focal Cerebral Ischemia ◽  
Vasogenic Edema ◽  
Tissue Inhibitor Of Metalloproteinase ◽  
Brain Barrier ◽  
Critical Event ◽  
Secondary Brain Injury ◽  
Blood Brain ◽  
Bbb Permeability

During cerebral ischemia blood–brain barrier (BBB) disruption is a critical event leading to vasogenic edema and secondary brain injury. Gelatinases A and B are matrix metalloproteinases (MMP) able to open the BBB. The current study analyzes by zymography the early gelatinases expression and activation during permanent ischemia in mice (n = 15). ProMMP-9 expression was significantly ( P < 0.001) increased in ischemic regions compared with corresponding contralateral regions after 2 hours of ischemia (mean 694.7 arbitrary units [AU], SD ± 238.4 versus mean 107.6 AU, SD ± 15.6) and remained elevated until 24 hours (mean 745,7 AU, SD ± 157.4). Moreover, activated MMP-9 was observed 4 hours after the initiation of ischemia. At the same time as the appearance of activated MMP-9, we detected by the Evan's blue extravasation method a clear increase of BBB permeability, Tissue inhibitor of metalloproteinase-1 was not modified during permanent ischemia at any time. The ProMMP-2 was significantly ( P < 0.05) increased only after 24 hours of permanent ischemia (mean 213.2 AU, SD ± 60.6 versus mean 94.6 AU, SD ± 13.3), and no activated form was observed. The appearance of activated MMP-9 after 4 hours of ischemia in correlation with BBB permeability alterations suggests that MMP-9 may play an active role in early vasogenic edema development after stroke.

scholarly journals Glycocalyx degradation leads to blood–brain barrier dysfunction and brain edema after asphyxia cardiac arrest in rats

2017 ◽  
Vol 38 (11) ◽  
pp. 1979-1992 ◽  
Author(s):  
Jiajia Zhu ◽  
Xing Li ◽  
Jia Yin ◽  
Yafang Hu ◽  
Yong Gu ◽  
...  
Keyword(s):  
Cardiac Arrest ◽  
Survival Rate ◽  
Brain Edema ◽  
Blood Brain Barrier ◽  
Brain Barrier ◽  
Neurologic Outcome ◽  
Endothelial Glycocalyx ◽  
Inflammatory Factors ◽  
Blood Brain ◽  
Bbb Permeability

The role of glycocalyx in blood–brain barrier (BBB) integrity and brain damage is poorly understood. Our study aimed to investigate the impacts of endothelial glycocalyx on BBB function in a rat model of cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). Male Sprague-Dawley rats subjected to 8-min asphyxia CA/CPR. Compared to controls, glycocalyx was mildly injured by CA, severely disrupted by hyaluronidase (HAase) with CA, and mitigated by hydrocortisone (HC) with CA. More importantly, the disruption of glycocalyx caused by HAase treatment was associated with higher BBB permeability and aggravated brain edema at 24 h after return of spontaneous circulation, as well as lower survival rate and poorer neurologic outcome at seventh day. Reversely, less degradation of glycocalyx by HC treatment was accompanied by higher seven-day survival rate and better neurologic outcome. Mechanistically, HAase treatment further increased CA/CPR-induced activation of glia cells and expression of inflammatory factors, whereas HC decreased them in the brain cortex and hippocampus. Glycocalyx degradation results in BBB leakage, brain edema, and deteriorates neurologic outcome after asphyxia CA/CPR in rats. Preservation of glycocalyx by HC could improve neurologic outcome and reduce BBB permeability, apparently through reduced gene transcription-protein synthesis and inflammation.

scholarly journals Blood-Brain Barrier and Exercise – a Short Review

2008 ◽  
Vol 19 (1) ◽  
pp. 83-92 ◽  
Author(s):  
Katarzyna Nierwińska ◽  
Elżbieta Malecka ◽  
Małgorzata Chalimoniuk ◽  
Aleksandra Żebrowska ◽  
Józef Langfort
Keyword(s):  
Blood Brain Barrier ◽  
Brain Injuries ◽  
Marked Change ◽  
Short Review ◽  
Brain Barrier ◽  
Neural Function ◽  
Normal Brain ◽  
Cns Injury ◽  
Blood Brain ◽  
Bbb Permeability

Blood-Brain Barrier and Exercise – a Short ReviewBlood-brain barier (BBB) segregates central nervous system (CNS) from the circulating blood. BBB is formed by the brain capillary endothelial cells with complex tight junctions between them as well as by astrocytes and pericytes. BBB is responsible for transport of selected chemicals into and out of the CNS as well as for its protection from fluctuations in plasma composition following meals, during exercise and from circulating agents such as neurotransmitters, xenobiotics and other potentially harmful substances capable to disturb neural function. BBB may be compromised during CNS injury, infection, fever and in some nerodegenerative diseases. The increase of BBB permeability was observed also during exercise as documented by changes of plasma S-100 protein levels, used as a peripheral marker of BBB integrity. Marked change in BBB integrity during exercise may disturb normal brain function and contribute to the development of central fatigue. Moreover, serum S-100β may indicate level of injury in individuals suffering brain injuries during sports. There are also data suggesting that acute effect of physical exercise on serum S100β levels may not be related with CNS injury. Further studies to establish whether training and which type of it may modulate BBB permeability are needed.

scholarly journals Angiogenesis and Blood-Brain Barrier Permeability in Vascular Remodeling after Stroke

2020 ◽  
Vol 18 (12) ◽  
pp. 1250-1265 ◽  
Author(s):  
Yi Yang ◽  
Michel T. Torbey
Keyword(s):  
Tight Junction ◽  
Blood Brain Barrier ◽  
Defense Mechanism ◽  
Vascular Endothelial Cells ◽  
Brain Plasticity ◽  
Normal Function ◽  
Brain Barrier ◽  
Neurologic Recovery ◽  
Blood Brain ◽  
Bbb Permeability

Angiogenesis, the growth of new blood vessels, is a natural defense mechanism helping to restore oxygen and nutrient supply to the affected brain tissue following an ischemic stroke. By stimulating vessel growth, angiogenesis may stabilize brain perfusion, thereby promoting neuronal survival, brain plasticity, and neurologic recovery. However, therapeutic angiogenesis after stroke faces challenges: new angiogenesis-induced vessels have a higher than normal permeability, and treatment to promote angiogenesis may exacerbate outcomes in stroke patients. The development of therapies requires elucidation of the precise cellular and molecular basis of the disease. Microenvironment homeostasis of the central nervous system is essential for its normal function and is maintained by the blood-brain barrier (BBB). Tight junction proteins (TJP) form the tight junction (TJ) between vascular endothelial cells (ECs) and play a key role in regulating the BBB permeability. We demonstrated that after stroke, new angiogenesis-induced vessels in peri-infarct areas have abnormally high BBB permeability due to a lack of major TJPs in ECs. Therefore, promoting TJ formation and BBB integrity in the new vessels coupled with speedy angiogenesis will provide a promising and safer treatment strategy for improving recovery from stroke. Pericyte is a central neurovascular unite component in vascular barriergenesis and are vital to BBB integrity. We found that pericytes also play a key role in stroke-induced angiogenesis and TJ formation in the newly formed vessels. Based on these findings, in this article, we focus on regulation aspects of the BBB functions and describe cellular and molecular special features of TJ formation with an emphasis on role of pericytes in BBB integrity during angiogenesis after stroke.

EXTH-07. TEMPORAL ASSESSMENT OF ALTERED PERI-ABLATION BLOOD-BRAIN BARRIER PERMEABILITY FOLLOWING TUMOR CYTOREDUCTION BY THERMAL THERAPY IN A RAT ORTHOTOPIC GLIOBLASTOMA MODEL

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi164-vi164
Author(s):  
Tavarekere Nagaraja ◽  
Seamus Bartlett ◽  
Glauber Cabral ◽  
Katelynn Farmer ◽  
Robert Knight ◽  
...  
Keyword(s):  
Blood Brain Barrier ◽  
Evans Blue ◽  
Thermal Therapy ◽  
Female Rats ◽  
Brain Barrier ◽  
Gadolinium Contrast ◽  
Dce Mri ◽  
Blood Brain ◽  
Bbb Permeability ◽  
Bbb Opening

Abstract Laser interstitial thermal therapy (LITT) is a minimally invasive tumor cytoreductive treatment for recurrent gliomas, brain tumors in eloquent regions and/or otherwise inaccessible. Following reports of persistent peri-ablation blood-brain barrier (BBB) opening in humans, we examined this phenomenon using a rat glioblastoma model. Athymic female rats were implanted with U251 tumor cells in one brain hemisphere. Tumor growth was monitored using magnetic resonance imaging (MRI) and dynamic contrast enhanced (DCE)-MRI. When tumors reached about 4 mm in diameter, they were ablated under supervision of diffusion-weighted MRI using Visualase®, a clinical LITT system. Four rats were used as controls. Longitudinal MRI data were obtained before LITT, and at post-LITT 2 (n=9), 3 (n=3) and 4 (n=9) weeks. After the terminal MRI at each time point, rats were injected intravenously with fluorescent isothiocyanate dextran (FITC-dextran; 2000 kDa) and Evans Blue (68 kDa after binding to plasma albumin) and the brains immersion fixed in 10% paraformaldehyde. The brains were cut into 100 μM thick slices in a vibratome and examined for the distribution of the two fluorophores. All rats survived the LITT procedure. The sham controls showed increased tumor burden by 2 weeks and were sacrificed. DCE-MRI data and fluorescent data showed elevated BBB permeability in peri-ablation regions, with leakage of a gadolinium contrast on DCE-MRI and of Evans Blue, but not of FITC-dextran. Histology showed little tumor tissue at 2 weeks, but evidence of recurrence at ablation margins at later times. These data demonstrate that LITT is adaptable to rat glioma models and can be performed under MRI monitoring. Peri-ablation regions showed selective increase in BBB permeability acutely due to sublethal heating, but later increases in permeability may be due to tumor recurrence. We suggest this model is useful for examining the temporal and spatial development of peri-ablation BBB opening following LITT.

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