Silencing CD28 attenuated chest blast exposure-induced traumatic brain injury through the PI3K/AKT/NF-κB signaling pathway in male mice.

In modern war or daily life, blast-induced traumatic brain injury (bTBI) is a growing health concern. Our previous studies demonstrated that inflammation was one of the main features of bTBI, and CD28-activated T cells play a central role in inflammation. However, the mechanism of CD28 in bTBI remains to be elucidated. In this study, traumatic brain injury model induced by chest blast exposure in male mice was established, and the mechanism of CD28 in bTBI was studied by elisa, immunofluorescence staining, flow cytometry analysis and western blot. After exposure to chest shock wave, the inflammatory factors IL-4, IL-6 and HMGB1 in serum were increased, and CD3+ T cells, CD4+ and CD8+ T cell subsets in the lung were activated. In addition, chest blast exposure resulted in impaired spatial learning and memory ability, disruption of the blood-brain barrier (BBB), and the expression of Tau, p-tau, S100ß and choline acetyltransferase were increased. The results indicated that genetic knockdown of CD28 could inhibit inflammatory cell infiltration, as well as the activation of CD3+ T cells, CD4+ and CD8+ T cell subsets in the lung, improve spatial learning and memory ability, and ameliorate BBB disruption and hippocampal neuron damage. Moreover, genetic knockdown of CD28 could reduce the expression of p-PI3K, p-AKT and NF-κB. In conclusion, chest blast exposure could lead to bTBI, and attenuate bTBI via the PI3K/AKT/NF-κB signaling pathway in male mice. This study provides new targets for the prevention and treatment of veterans with bTBI.

Radiological Findings in Reversible Cerebral Vasoconstriction Syndrome: A Systematic Review of Literature.

Reversible cerebral vasoconstriction syndrome (RCVS) poses a complex neurological challenge characterized by sudden, severe headaches and multifocal cerebral vasoconstriction. While our understanding of its clinical aspects and underlying mechanisms has advanced, the focus of investigation remains on radiological manifestations. This systematic review aims to comprehensively analyze the existing literature on radiological findings in RCVS, synthesizing evidence from diverse imaging modalities to enhance the understanding of imaging features associated with the syndrome. Accurate diagnosis based on radiological findings is pivotal for initiating appropriate management and preventing complications. Specific markers may facilitate the differentiation of RCVS from other conditions, thereby enhancing patient care. This review explores a wide range of radiological presentations, from vasoconstriction to infarctions and hemorrhages, thereby refining diagnostic criteria and guiding clinical practice. By consolidating current knowledge, the review sheds light on areas of consensus, controversies, and gaps, with the aim of serving as a comprehensive resource for evidence-based decision-making.

PEG length effect of peptide-functional liposome for blood brain barrier (BBB) penetration and brain targeting.

Nanoparticles, in particular PEGylated, show great potential for in vivo brain targeted drug delivery. Nevertheless, how polyethylene glycol (PEG) length of nanoparticles affects their blood brain barrier (BBB) penetration or brain targeting is still unclear. In this study, we investigated the power of PEG chain-lengths (2, 3.4, 5, 10 kDa) in BBB penetration and brain targeting using Angiopep-2 peptide decorated liposomes. We found that PEG chain-length is critical, where the shorter PEG enabled the Angiopep-2 decorated liposomes to display more potent in vitro cell uptake via endocytosis. In contrast, their in vitro BBB penetration via transcytosis was much weaker relative to the liposomes with longer PEG chains, which result from their ineffective BBB exocytosis. Interestingly, the in vivo brain targeting aligns with the in vitro BBB penetration, as the long chain PEG-modified liposomes exerted superior brain accumulation both in normal or orthotropic glioblastoma (GBM) bearing mice, which could be ascribed to the combinational effect of prolonged circulation and enhanced BBB penetration of long chain PEG attached liposomes. These results demonstrate the crucial role of PEG length of nanoparticles for BBB penetration and brain targeting, providing guidance for PEG length selection in the design of nanocarrier for brain diseases treatment.

Cerebrospinal Fluid Proteome Map Reveals Molecular Signatures of Reversible Cerebral Vasoconstriction Syndrome.

Reversible cerebral vasoconstriction syndrome (RCVS) is a complex neurovascular disorder characterized by repetitive thunderclap headaches and reversible cerebral vasoconstriction. The pathophysiological mechanism of this mysterious syndrome remains under-explored and there is no clinically available molecular biomarker. To provide insight into the pathogenesis of RCVS, this study reported the first landscape of dysregulated proteome of cerebrospinal fluid (CSF) in patients with RCVS (n = 21) compared to the age- and sex-matched controls (n = 20) using data-independent acquisition mass spectrometry (DIA-MS). Protein-protein interaction and functional enrichment analysis were employed to construct functional protein networks using the RCVS proteome. An RCVS-CSF proteome library resource of 1,054 proteins was established, which illuminated large groups of upregulated proteins enriched in the brain and blood-brain barrier (BBB). Personalized RCVS-CSF proteomic profiles from 17 RCVS patients and 20 controls reveal proteomic changes involving the complement system, adhesion molecules, and extracellular matrix, which may contribute to the disruption of BBB and dysregulation of neurovascular units. Moreover, an additional validation cohort validated a panel of biomarker candidates and a two-protein signature predicted by machine learning model to discriminate RCVS patients from controls with an area under the curve of 0.997. This study reveals the first RCVS proteome and a potential pathogenetic mechanism of BBB and neurovascular unit dysfunction. It also nominates potential biomarker candidates that are mechanistically plausible for RCVS, which may offer potential diagnostic and therapeutic opportunities beyond the clinical manifestations.

Blood-brain barrier dysfunction and decreased transcription of tight junction proteins in epileptic dogs.

BACKGROUND: Epilepsy in dogs and humans is associated with blood-brain barrier (BBB) dysfunction (BBBD), which may involve dysfunction of tight junction (TJ) proteins, matrix metalloproteases, and astrocytes. Imaging techniques to assess BBB integrity, to identify potential treatment strategies, have not yet been evaluated in veterinary medicine. HYPOTHESIS: Some dogs with idiopathic epilepsy (IE) will exhibit BBBD. Identifying BBBD may improve antiepileptic treatment in the future. ANIMALS: Twenty-seven dogs with IE and 10 healthy controls. METHODS: Retrospective, prospective cohort study. Blood-brain barrier permeability (BBBP) scores were calculated for the whole brain and piriform lobe of all dogs by using dynamic contrast enhancement (DCE) magnetic resonance imaging (MRI) and subtraction enhancement analysis (SEA). Matrix metalloproteinase-9 (MMP9) activity in serum and cerebrospinal fluid (CSF) was measured and its expression in the piriform lobe was examined using immunofluorescent staining. Gene expression of TJ proteins and astrocytic transporters was analyzed in the piriform lobe. RESULTS: The DCE-MRI analysis of the piriform lobe identified higher BBBP score in the IE group when compared with controls (34.5% vs 26.5%; P = .02). Activity and expression of MMP9 were increased in the serum, CSF, and piriform lobe of IE dogs as compared with controls. Gene expression of Kir4.1 and claudin-5 in the piriform lobe of IE dogs was significantly lower than in control dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Our findings demonstrate BBBD in dogs with IE and were supported by increased MMP9 activity and downregulation of astrocytic potassium channels and some TJ proteins. Blood brain barrier dysfunction may be a novel antiepileptic therapy target.

Alterations in brain fluid physiology during the early stages of development of ischaemic oedema.

Oedema occurs when higher than normal amounts of solutes and water accumulate in tissues. In brain parenchymal tissue, vasogenic oedema arises from changes in blood-brain barrier permeability, e.g. in peritumoral oedema. Cytotoxic oedema arises from excess accumulation of solutes within cells, e.g. ischaemic oedema following stroke. This type of oedema is initiated when blood flow in the affected core region falls sufficiently to deprive brain cells of the ATP needed to maintain ion gradients. As a consequence, there is: depolarization of neurons; neural uptake of Na+ and Cl- and loss of K+; neuronal swelling; astrocytic uptake of Na+, K+ and anions; swelling of astrocytes; and reduction in ISF volume by fluid uptake into neurons and astrocytes. There is increased parenchymal solute content due to metabolic osmolyte production and solute influx from CSF and blood. The greatly increased [K+]isf triggers spreading depolarizations into the surrounding penumbra increasing metabolic load leading to increased size of the ischaemic core. Water enters the parenchyma primarily from blood, some passing into astrocyte endfeet via AQP4. In the medium term, e.g. after three hours, NaCl permeability and swelling rate increase with partial opening of tight junctions between blood-brain barrier endothelial cells and opening of SUR1-TPRM4 channels. Swelling is then driven by a Donnan-like effect. Longer term, there is gross failure of the blood-brain barrier. Oedema resolution is slower than its formation. Fluids without colloid, e.g. infused mock CSF, can be reabsorbed across the blood-brain barrier by a Starling-like mechanism whereas infused serum with its colloids must be removed by even slower extravascular means. Large scale oedema can increase intracranial pressure (ICP) sufficiently to cause fatal brain herniation. The potentially lethal increase in ICP can be avoided by craniectomy or by aspiration of the osmotically active infarcted region. However, the only satisfactory treatment resulting in retention of function is restoration of blood flow, providing this can be achieved relatively quickly. One important objective of current research is to find treatments that increase the time during which reperfusion is successful. Questions still to be resolved are discussed.

Progresses in the establishment, evaluation, and application of in vitro blood-brain barrier models.

The blood-brain barrier (BBB) is a barrier between the circulatory system and the central nervous system (CNS), contributing to CNS protection and maintaining the brain homeostasis. Establishment of in vitro BBB models that are closer to the microenvironment of the human brain is helpful for evaluating the potential and efficiency of a drug penetrating BBB and thus the clinical application value of the drug. The in vitro BBB models not only provide great convenience for screening new drugs that can access to CNS but also help people to have a deeper study on the mechanism of substances entering and leaving the brain, which makes people have greater opportunities in the treatment of CNS diseases. Up to now, although much effort has been paid to the researches on the in vitro BBB models and many progresses have been achieved, no unified method has been described for establishing a BBB model and there is much work to do and many challenges to be faced with in the future. This review summarizes the research progresses in the establishment, evaluation, and application of in vitro BBB models.

Translation from Preclinical Research to Clinical Trials: Transdermal Drug Delivery for Neurodegenerative and Mental Disorders.

Neurodegenerative diseases (NDs), particularly dementia, provide significant problems to worldwide healthcare systems. The development of therapeutic materials for various diseases has a severe challenge in the form of the blood-brain barrier (BBB). Transdermal treatment has recently garnered widespread favor as an alternative method of delivering active chemicals to the brain. This approach has several advantages, including low invasiveness, self-administration, avoidance of first-pass metabolism, preservation of steady plasma concentrations, regulated release, safety, efficacy, and better patient compliance. Topics include the transdermal method for therapeutic NDs, their classification, and the mechanisms that allow the medicine to enter the bloodstream through the skin. The paper also discusses the obstacles and potential outcomes of transdermal therapy, emphasizing the benefits and drawbacks of different approaches.

Prediction of blood-brain barrier permeability using machine learning approaches based on various molecular representation.

The assessment of compound blood-brain barrier (BBB) permeability poses a significant challenge in the discovery of drugs targeting the central nervous system. Conventional experimental approaches to measure BBB permeability are labor-intensive, cost-ineffective, and time-consuming. In this study, we constructed six machine learning classification models by combining various machine learning algorithms and molecular representations. The model based on ExtraTree algorithm and random partitioning strategy obtains the best prediction result, with AUC value of 0.932±0.004 and balanced accuracy (BA) of 0.837±0.010 for the test set. We employed the SHAP method to identify important features associated with BBB permeability. In addition, matched molecular pair (MMP) analysis and representative substructure derivation method were utilized to uncover the transformation rules and distinctive structural features of BBB permeable compounds. The machine learning models proposed in this work can serve as an effective tool for assessing BBB permeability in the drug discovery for central nervous system disease.

Functionalized nanoparticles to deliver nucleic acids to the brain for the treatment of Alzheimer's disease.

Brain-targeted gene delivery across the blood-brain barrier (BBB) is a significant challenge in the 21st century for the healthcare sector, particularly in developing an effective treatment strategy against Alzheimer's disease (AD). The Internal architecture of the brain capillary endothelium restricts bio-actives entry into the brain. Additionally, therapy with nucleic acids faces challenges like vulnerability to degradation by nucleases and potential immune responses. Functionalized nanocarrier-based gene delivery approaches have resulted in safe and effective platforms. These nanoparticles (NPs) have demonstrated efficacy in protecting nucleic acids from degradation, enhancing transport across the BBB, increasing bioavailability, prolonging circulation time, and regulating gene expression of key proteins involved in AD pathology. We provided a detailed review of several nanocarriers and targeting ligands such as cell-penetrating peptides (CPPs), endogenous proteins, and antibodies. The utilization of functionalized NPs extends beyond a singular system, serving as a versatile platform for customization in related neurodegenerative diseases. Only a few numbers of bioactive regimens can go through the BBB. Thus, exploring functionalized NPs for brain-targeted gene delivery is of utmost necessity. Currently, genes are considered high therapeutic potential molecules for altering any disease-causing gene. Through surface modification, nanoparticulate systems can be tailored to address various diseases by replacing the target-specific molecule on their surface. This review article presents several nanoparticulate delivery systems, such as lipid NPs, polymeric micelles, exosomes, and polymeric NPs, for nucleic acids delivery to the brain and the functionalization strategies explored in AD research.

Establishment of a Four-Cell In Vitro Blood-Brain Barrier Model With Human Primary Brain Cells.

The blood-brain barrier (BBB) constitutes a crucial protective anatomical layer with a microenvironment that tightly controls material transit. Constructing an in vitro BBB model to replicate in vivo features requires the sequential layering of constituent cell types. Maintaining heightened integrity in the observed tight junctions during both the establishment and post-experiment phases is crucial to the success of these models. We have developed an in vitro BBB model that replicates the cellular composition and spatial orientation of in vivo BBB observed in humans. The experiment includes comprehensive procedures and steps aimed at enhancing the integration of the four-cell model. Departing from conventional in vitro BBB models, our methodology eliminates the necessity for pre-coated plates to facilitate cell adhesion, thereby improving cell visualization throughout the procedure. An in-house coating strategy and a simple yet effective approach significantly reduce costs and provides superior imaging of cells and corresponding tight junction protein expression. Also, our BBB model includes all four primary cell types that are structural parts of the human BBB. With its innovative and user-friendly features, our in-house optimized in vitro four-cell-based BBB model showcases novel methodology and provides a promising experimental platform for drug screening processes. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Coating and culture system Basic Protocol 2: Cell seeding and Transwell insert handling Basic Protocol 3: Assessment of model functionality.

Preclinical systemic pharmacokinetics, dose-proportionality, and CNS distribution of the ATM inhibitor WSD0628, a novel radiosensitizer for the treatment of brain tumors.

Radiation therapy, a standard treatment option for many cancer patients, induces DNA double strand breaks (DSBs), leading to cell death. Ataxia telangiectasia mutated (ATM) kinase is a key regulator of DSB repair, and ATM inhibitors are being explored as radiosensitizers for various tumors, including primary and metastatic brain tumors. Efficacy of radiosensitizers for brain tumors may be influenced by a lack of effective drug delivery across the blood-brain barrier (BBB). The objective of this study was to evaluate the systemic pharmacokinetics and mechanisms that influence the CNS distribution of WSD0628, a novel and potent ATM inhibitor, in the mouse. Further, we have used these observations to form the basis of predicting effective exposures for clinical application. We observed a greater than dose proportional increase in exposure, likely due to saturation of clearance processes. Our results show that WSD0628 is orally bioavailable and CNS penetrant, with unbound partitioning in CNS (i.e., Kpuu) between 0.15 and 0.3. CNS distribution is not limited by the efflux transporters P-gp and Bcrp. WSD0628 is distributed uniformly amongst different brain regions. Thus, WSD0628 has favorable pharmacokinetic properties and potential for further exploration to determine the PK-PD-efficacy relationship in CNS tumors. This approach will provide critical insights for the clinical translation of WSD0628 for the treatment of primary and secondary brain tumors. Significance Statement This study evaluates the preclinical systemic pharmacokinetics, dose proportionality, and mechanisms influencing CNS distribution of WSD0628, a novel ATM inhibitor for the treatment of brain tumors. Results indicate that WSD0628 is orally bioavailable and CNS penetrant without efflux transporter liability. We also observed a greater than dose-proportional increase in exposure in both the plasma and brain. These favorable pharmacokinetic properties indicate WSD0628 has potential for further exploration for use as a radiosensitizer in the treatment of brain tumors.

Alzheimer's disease and drug delivery across the blood-brain barrier: approaches and challenges.

Alzheimer's disease (AD) is a diverse disease with a complex pathophysiology. The presence of extracellular ß-amyloid deposition as neuritic plaques and intracellular accumulation of hyper-phosphorylated tau as neurofibrillary tangles remain the core neuropathologic criteria for diagnosing Alzheimer's disease. Nonetheless, several recent basic discoveries have revealed significant pathogenic roles for other essential cellular and molecular processes. Previously, there were not so many disease-modifying medications (DMT) available as drug distribution through the blood-brain barrier (BBB) is difficult due to its nature, especially drugs of polypeptides nature and proteins. Recently FDA has approved lecanemab as DMT for its proven efficacy. It is also complicated to deliver drugs for diseases like epilepsy or any brain tumor due to the limitations of the BBB. After the advancements in the drug delivery system, different techniques are used to transport the medication across the BBB. Other methods are used, like enhancement of brain blood vessel fluidity by liposomes, infusion of hyperosmotic solutions, and local intracerebral implants, but these are invasive approaches. Non-invasive approaches include the formulation of nanoparticles and their coating with polymers. This review article emphasizes all the above-mentioned techniques, procedures, and challenges to transporting medicines across the BBB. It summarizes the most recent literature dealing with drug delivery across the BBB.

The Drosophila blood-brain barrier invades the nervous system in a GPCR-dependent manner.

The blood-brain barrier (BBB) represents a crucial interface between the circulatory system and the brain. In Drosophila melanogaster, the BBB is composed of perineurial and subperineurial glial cells. The perineurial glial cells are small mitotically active cells forming the outermost layer of the nervous system and are engaged in nutrient uptake. The subperineurial glial cells form occluding septate junctions to prevent paracellular diffusion of macromolecules into the nervous system. To address whether the subperineurial glia just form a simple barrier or whether they establish specific contacts with both the perineurial glial cells and inner central nervous system (CNS) cells, we undertook a detailed morphological analysis. Using genetically encoded markers alongside with high-resolution laser scanning confocal microscopy and transmission electron microscopy, we identified thin cell processes extending into the perineurial layer and into the CNS cortex. Interestingly, long cell processes were observed reaching the glia ensheathing the neuropil of the central brain. GFP reconstitution experiments highlighted multiple regions of membrane contacts between subperineurial and ensheathing glia. Furthermore, we identify the G-protein-coupled receptor (GPCR) Moody as negative regulator of the growth of subperineurial cell processes. Loss of moody triggered a massive overgrowth of subperineurial cell processes into the CNS cortex and, moreover, affected the polarized localization of the xenobiotic transporter Mdr65. Finally, we found that GPCR signaling, but not septate junction formation, is responsible for controlling membrane overgrowth. Our findings support the notion that the Drosophila BBB is able to bridge the communication gap between circulation and synaptic regions of the brain by long cell processes.

Carbon dots as dual inhibitors of tau and amyloid-beta aggregation for the treatment of Alzheimer's disease.

Alzheimer's disease (AD) is the most common form of senile dementia, presenting a significant challenge for the development of effective treatments. AD is characterized by extracellular amyloid plaques and intraneuronal neurofibrillary tangles. Therefore, targeting both hallmarks through inhibition of amyloid beta (Aß) and tau aggregation presents a promising approach for drug development. Carbon dots (CD), with their high biocompatibility, minimal cytotoxicity, and blood-brain barrier (BBB) permeability, have emerged as promising drug nanocarriers. Congo red, an azo dye, has gathered significant attention for inhibiting amyloid-beta and tau aggregation. However, Congo red's inability to cross the BBB limits its potential to be used as a drug candidate for central nervous system (CNS) diseases. Furthermore, current studies only focus on using Congo red to target single disease hallmarks, without investigating dual inhibition capabilities. In this study, we synthesized Congo red-derived CD (CRCD) by using Congo red and citric acid as precursors, resulting in three variants, CRCD1, CRCD2 and CRCD3, based on different mass ratios of precursors. CRCD2 and CRCD3 exhibited sustained low cytotoxicity, and CRCD3 demonstrated the ability to traverse the BBB in a zebrafish model. Moreover, thioflavin T (ThT) aggregation assays and AFM imaging revealed CRCD as potent inhibitors against both tau and Aß aggregation. Notably, CRCD1 emerged as the most robust inhibitor, displaying IC50 values of 0.2 ± 0.1 and 2.1 ± 0.5 µg/mL against tau and Aß aggregation, respectively. Our findings underscore the dual inhibitory role of CRCD against tau and Aß aggregation, showcasing effective BBB penetration and positioning CRCD as potential nanodrugs and nanocarriers for the CNS. Hence, CRCD-based compounds represent a promising candidate in the realm of multi-functional AD therapeutics, offering an innovative formulation component for future developments in this area. STATEMENT OF SIGNIFICANCE: This article reports Congo red-derived carbon dots (CRCD) as dual inhibitors of tau and amyloid-beta (Aß) aggregation for the treatment of Alzheimer's disease (AD). The CRCD are biocompatible and show strong fluorescence, high stability, the ability to cross the blood-brain barrier, and the function of addressing two major pathological features of AD.

Amelioration of experimental autoimmune encephalomyelitis by gemfibrozil in mice via PPARß/δ: implications for multiple sclerosis.

It is important to describe effective and non-toxic therapies for multiple sclerosis (MS), an autoimmune demyelinating disease. Experimental autoimmune encephalomyelitis (EAE) is an immune-mediated inflammatory disease that serves as a model for MS. Earlier we and others have shown that, gemfibrozil, a lipid-lowering drug, exhibits therapeutic efficacy in EAE. However, the underlying mechanism was poorly understood. Although gemfibrozil is a known ligand of peroxisome proliferator-activated receptor α (PPARα), here, we established that oral administration of gemfibrozil preserved the integrity of blood-brain barrier (BBB) and blood-spinal cord barrier (BSB), decreased the infiltration of mononuclear cells into the CNS and inhibited the disease process of EAE in both wild type and PPARα-/- mice. On the other hand, oral gemfibrozil was found ineffective in maintaining the integrity of BBB/BSB, suppressing inflammatory infiltration and reducing the disease process of EAE in mice lacking PPARß (formerly PPARδ), indicating an important role of PPARß/δ, but not PPARα, in gemfibrozil-mediated preservation of BBB/BSB and protection of EAE. Regulatory T cells (Tregs) play a critical role in the disease process of EAE/MS and we also demonstrated that oral gemfibrozil protected Tregs in WT and PPARα-/- EAE mice, but not PPARß-/- EAE mice. Taken together, our findings suggest that gemfibrozil, a known ligand of PPARα, preserves the integrity of BBB/BSB, enriches Tregs, and inhibits the disease process of EAE via PPARß, but not PPARα.

Charge-switchable cell-penetrating peptides for rerouting nanoparticles to glioblastoma treatment.

Glioblastoma (GB) is one of the most lethal types of neoplasms with unique anatomic, physiologic, and pathologic features that usually persist after exposure to standard therapeutic modalities. It is biologically aggressive, and the existence of the blood-brain barrier (BBB) limits the efficacy of standard therapies. In this work, we hypothesize the potential of surface-functionalized ultra-small nanostructured lipid carriers (usNLCs) with charge-switchable cell-penetrating peptides (CPPs) to overcome this biological barrier and improve targeted delivery to brain tumor tissues. The big question is: what is the potential of CPPs in directing nanoparticles toward brain tumor tissue? To answer this question, the usNLCs were functionalized with distinct biomolecules [five CPPs, c(RGDfK) and transferrin, Tf] through electrostatic interaction and its ability as a targeting approach to BBB (HBMEC) and glioma cells (U87 cells) evaluated in terms of physicochemical properties, cellular uptake, permeability in a 2D-BBB model, and tumor growth inhibition. Monte Carlo simulations elucidated CPP adsorption patterns. The permeability studies revealed that targeted usNLCs, especially usNLCsTf and usNLCsCPP4, exhibited an increased permeability coefficient compared to the non-targeted usNLCs. Functionalized usNLCs evidenced enhanced uptake in BBB cells, with smaller CPPs showing higher internalization (CPP1 and CPP2). Similarly, functionalized usNLCs exhibited more significant cytotoxicity in glioma cells, with specific CPPs promoting favorable internalization. Analysis of the endocytic pathway indicated that usNLCsCPPs were mainly internalized by direct translocation and caveolae-mediated endocytosis. Optimal usNLCs with dual targeting capabilities to both BBB and GB cells provide a promising therapeutic strategy for GB.

Mechanisms of QiShenYiQi in Inhibiting Blood-Brain Barrier Damage Following Stroke: A Network Pharmacology and Experimental Study.

BACKGROUND AND PURPOSE: QiShenYiQi (QSYQ) has shown promise in the treatment of blood-brain barrier (BBB) damage following stroke. However, the identification of its bioactive components and the underlying molecular mechanisms of action remain unknown. This study aimed to investigate the active ingredients and mechanisms involved in the inhibitory effects of QSYQ on BBB damage after ischemic stroke based on network pharmacology and experimental verification. MATERIALS AND METHODS: The chemical composition and target information of QSYQ were obtained from the Traditional Chinese Medicine Systems Pharmacology and Analysis Platform. BBB injury-related targets were identified by screening databases, and the overlapping targets with QSYQ were collected. Cytoscape software was utilized to construct protein-protein interaction (PPI) networks. Molecular docking analysis was conducted using AutoDock software. Animal experiments were carried out to verify the protective effect of QSYQ on BBB and explore potential molecular mechanisms. RESULTS: A total of 131 active ingredients in QSYQ and 154 common targets related to QSYQ and BBB damage were identified. Analysis of the PPI network revealed key targets including ALB, INS, ACTB, TP53, and CASP3 against BBB injury. Molecular docking analysis indicated favorable binding interactions between dihydrotanshinlactone, tanshinone IIA, salviolone, and their respective target proteins, such as FOS, INS, CASP3, and JUN. In animal experiments, QSYQ demonstrated effective inhibition of BBB damage, and this effect may be attributed to the regulation of ALB, INS, TP53, and CASP3. CONCLUSION: This study provides intriguing insights into the mechanisms by which QSYQ protects against BBB injury following ischemic stroke. Key targets, including ALB, INS, TP53, and CASP3, could be potentially involved in the beneficial effects of QSYQ.

18F-Labeled dihydropyridines via Hantzsch reaction for positron emission tomography of P-glycoprotein dysfunction.

Despite the availability of various 11C-labeled positron emission tomography (PET) tracers for assessing P-glycoprotein (P-gp) function, there are still limitations related to complex metabolism, high lipophilicity, and low baseline uptake. This study aimed to address these issues by exploring a series of customized dihydropyridines (DHPs) with enhanced stability and reduced lipophilicity as alternative PET tracers for P-gp dysfunction. Compared with verapamil and the rest DHPs, dimethyl 4-(4-fluorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (1) exhibited superior cellular uptake differences between the human gastric cancer cell line SGC7901 and its drug-resistant counterpart. [18F]1 is successfully synthesized using a novel "hot-Hantzsch" approach in 22.1 ± 0.1 % radiochemical yields. MicroPET/CT imaging demonstrated that the uptake of [18F]1 in the brains of P-gp blocked mice increased by > 3 times compared to the control group. Additionally, [18F]1 displayed favorable lipophilicity (log D = 2.3) and excellent clearance characteristics, making it a promising tracer candidate with low background noise and high contrast.