Blood-Brain Barrier (BBB)-Crossing Strategies for Improved Treatment of CNS Disorders.

Blood-brain barrier (BBB) is a special biological property of the brain neurovascular unit (including brain microvessels and capillaries), which facilitates the transport of nutrients into the central nervous system (CNS) and exchanges metabolites but restricts passage of blood-borne neurotoxic substances and drugs/xenobiotics into CNS. BBB plays a crucial role in maintaining the homeostasis and normal physiological functions of CNS but severely impedes the delivery of drugs and biotherapeutics into CNS for treatment of neurological disorders. A variety of technologies have been developed in the past decade for brain drug delivery. Most of these technologies are still in preclinical stage and some are undergoing clinical studies. Only a few have been approved by regulatory agencies for clinical applications. This chapter will overview the strategies and technologies/approaches for brain drug delivery and discuss some of the recent advances in the field.

Donor-Acceptor Type Covalent Organic Frameworks.

Intermolecular charge transfer (ICT) effect has been widely studied in both small molecules and linear polymers. Covalently-bonded donor-acceptor pairs with tunable bandgaps and photoelectric properties endow these materials with potential applications in optoelectronics, fluorescent bioimaging, and sensors, etc. However, owing to the lack of charge transfer pathway or effective separation of charge carriers, unfavorable charge recombination gives rise to inevitable energy loss. Covalent organic frameworks (COFs) can be mediated with various geometry- and property-tailored building blocks, where donor (D) and acceptor (A) segments are connected by covalent bonds and can be finely arranged to form highly ordered networks (namely D-A COFs). The unique structural features of D-A COFs render the formation of segregated D-A stacks, thus provides pathways and channels for effective charge carriers transport. This review highlights the significant progress on D-A COFs over the past decade with emphasis on design principles, growing structural diversities, and promising application potentials.

Semicovariance Coefficient Analysis of Spike Proteins from SARS-CoV-2 and Other Coronaviruses for Viral Evolution and Characteristics Associated with Fatality.

Complex modeling has received significant attention in recent years and is increasingly used to explain statistical phenomena with increasing and decreasing fluctuations, such as the similarity or difference of spike protein charge patterns of coronaviruses. Different from the existing covariance or correlation coefficient methods in traditional integer dimension construction, this study proposes a simplified novel fractional dimension derivation with the exact Excel tool algorithm. It involves the fractional center moment extension to covariance, which results in a complex covariance coefficient that is better than the Pearson correlation coefficient, in the sense that the nonlinearity relationship can be further depicted. The spike protein sequences of coronaviruses were obtained from the GenBank and GISAID databases, including the coronaviruses from pangolin, bat, canine, swine (three variants), feline, tiger, SARS-CoV-1, MERS, and SARS-CoV-2 (including the strains from Wuhan, Beijing, New York, German, and the UK variant B.1.1.7) which were used as the representative examples in this study. By examining the values above and below the average/mean based on the positive and negative charge patterns of the amino acid residues of the spike proteins from coronaviruses, the proposed algorithm provides deep insights into the nonlinear evolving trends of spike proteins for understanding the viral evolution and identifying the protein characteristics associated with viral fatality. The calculation results demonstrate that the complex covariance coefficient analyzed by this algorithm is capable of distinguishing the subtle nonlinear differences in the spike protein charge patterns with reference to Wuhan strain SARS-CoV-2, which the Pearson correlation coefficient may overlook. Our analysis reveals the unique convergent (positive correlative) to divergent (negative correlative) domain center positions of each virus. The convergent or conserved region may be critical to the viral stability or viability; while the divergent region is highly variable between coronaviruses, suggesting high frequency of mutations in this region. The analyses show that the conserved center region of SARS-CoV-1 spike protein is located at amino acid residues 900, but shifted to the amino acid residues 700 in MERS spike protein, and then to amino acid residues 600 in SARS-COV-2 spike protein, indicating the evolution of the coronaviruses. Interestingly, the conserved center region of the spike protein in SARS-COV-2 variant B.1.1.7 shifted back to amino acid residues 700, suggesting this variant is more virulent than the original SARS-COV-2 strain. Another important characteristic our study reveals is that the distance between the divergent mean and the maximal divergent point in each of the viruses (MERS > SARS-CoV-1 > SARS-CoV-2) is proportional to viral fatality rate. This algorithm may help to understand and analyze the evolving trends and critical characteristics of SARS-COV-2 variants, other coronaviral proteins and viruses.

A Novel Chinese Medicine, Xinfeng Capsule, Modulates Proinflammatory Cytokines via Regulating the Toll-Like Receptor 4 (TLR4)/Mitogen-Activated Protein Kinase (MAPK)/Nuclear Kappa B (NF-κB) Signaling Pathway in an Adjuvant Arthritis Rat Model.

BACKGROUND Rheumatoid arthritis (RA) is a chronic autoimmune disease targeting joints. This research aimed to explore the effects of Xinfeng capsules (XFC) on cardiac injury in adjuvant arthritis (AA) model rats and assessed the associated mechanism. MATERIAL AND METHODS An adjuvant arthritis (AA) rat model was established by intracutaneously injection with Freund's complete adjuvant (FCA). Model rats were divided into 4 groups: an AA model group, an astragalus polysaccharides (APS) group, a methotrexate (MTX) group, and an XFC and triptolide (TPT) group. Hematoxylin-eosin (HE) staining was used to observe histopathologic changes. TUNEL assay was utilized to evaluate the apoptosis of cardiomyocytes. ELISA was utilized to evaluate levels of tumor necrosis factor alpha (TNF-alpha), interleukin 17 (IL-17), and interleukin 6 (IL-6) in myocardial tissues. Quantitative RT-PCR (qRT-PCR) was used to detect microRNA-21 (miRNA21) levels. Mitogen-activated protein kinase (MAPK)/p38, Toll-like receptor 4 (TLR4), and nuclear kappa B (NF-kappaB)/p65 levels were evaluated using Western blot. RESULTS XFC significantly improved proinflammatory response compared to the AA model group (p<0.05). XFC treatment significantly decreased the number of cells staining TUNEL-positive compared with the model group (p<0.05). XFC treatment significantly reduced TNF-alpha, IL-17, and IL-6 levels in myocardial tissues compared to the model group (p<0.05). Levels of miRNA21 were significantly lower in the XFC group compared to the AA model group (p<0.05). TLR4, MAPK/p38, and NF-kappaB/p65 expression levels were significantly lower in the XFC group than in the model group (p<0.05). CONCLUSIONS Xinfeng capsule, a traditional Chinese medicine preparation, protects against cardiac injury in AA rats by modulating proinflammatory cytokines expression via the TLR4/MAPK/NF-kappaB signaling pathway.

Drug Distribution into Peripheral Nerve.

Little is known about the impact of the blood-nerve barrier (BNB) on drug distribution into peripheral nerves. In this study, we examined the peripheral nerve penetration in rats of 11 small-molecule drugs possessing diverse physicochemical and transport properties and ProTx-II, a tarantula venom peptide with molecular mass of 3826 Daltons. Each drug was administered as constant rate intravenous infusion for 6 hours (small molecules) or 24 hours (ProTx-II). Blood and tissues including brain, spinal cord, sciatic nerve, and dorsal root ganglion (DRG) were collected for drug concentration measurements. Unbound fractions of a set of compounds were determined by equilibrium dialysis method in rat blood, brains, spinal cords, sciatic nerves, and DRG. We also investigated the influence of N-[4-[2-(6,7-dimethoxy-3,4-dihydro-1H-isoquinolin-2-yl)ethyl]phenyl]-5-methoxy-9-oxo-10H-acridine-4-carboxamide (GF120918), a P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) inhibitor, on the peripheral nerve and central nervous system (CNS) tissue penetration of imatinib. We found that: 1) the unbound fraction in brain tissue homogenate highly correlates with that in the spinal cord, sciatic nerve, and DRG for a set of compounds and thus provides a good surrogate for spinal cord and peripheral nerve tissues, 2) small-molecule drugs investigated can penetrate the DRG and sciatic nerve, 3) P-gp and BCRP have a limited impact on the distribution of small-molecule drugs into peripheral nerves, and 4) DRG is permeable to ProTx-II, but its distribution into sciatic nerve and CNS tissues is restricted. These results demonstrate that small-molecule drugs investigated can penetrate peripheral nerve tissues, and P-gp/BCRP may not be a limiting factor at the BNB. Biologics as large as ProTx-II can access the DRG but not sciatic nerve and CNS tissues.

Correlation between Membrane Protein Expression Levels and Transcellular Transport Activity for Breast Cancer Resistance Protein.

Emerging evidence indicates an important role for the breast cancer resistance protein (BCRP) in limiting brain penetration of substrate drugs. While in vitro transwell assays can provide an indication of BCRP substrate potential, the predictability of these assays in relation to in vivo brain penetration is still under debate. The present study examined the correlation of BCRP membrane protein expression level and transcellular transport activity across Madin-Darby canine kidney (MDCK) II monolayers. We expressed human BCRP or murine BCRP1 in MDCKII wild-type cells using BacMam2 virus transduction. The selective P-glycoprotein (P-gp) inhibitor LY335979 (1 µM) was included in the transport medium to measure BCRP-mediated transcellular transport for P-gp and BCRP cosubstrates. The BCRP levels in membrane extracts from MDCKII-BCRP or MDCKII-Bcrp1 cells were quantified by liquid chromatography-tandem mass spectrometry. The results are summarized as follows: 1) the membrane protein expression levels correlate with the corrected efflux ratios of substrates for human BCRP and murine BCRP1 within the efflux ratios investigated; 2) we demonstrate good concordance in rank order between the BCRP and BCRP1-mediated efflux ratios for 12 drugs; and 3) we propose an approach to contextualize in vitro BCRP transport data of discovery compounds by comparing them to the in vitro and in vivo transport data of the reference drug dantrolene and taking into account interbatch variation in BCRP expression. This approach correctly predicted compromised brain penetration for 25 discovery compounds in rodents, which were BCRP substrates but not P-gp or weak P-gp substrates. These results suggest that BCRP-expressing MDCKII cells are useful in predicting the in vivo role of BCRP in brain penetration.

Mechanism studies of Xinfeng capsule on improving cardiovascular function though toll-like receptor 4/nuclear factor kappa B pathway in a rat model of adjuvant arthritis.

OBJECTIVE: To observe the impact of Xinfeng capsule (XFC) on cardiovascular function in adjuvant arthritis (AA) model rats and investigate the mechanism though toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway. METHODS: Seventy rats were randomly divided into seven groups: normal control (NC), model control (MC), tripterygium glycosides tablet (TPT), methotrexate (MTX), high, moderate and low dose XFC group. The administration began from day 19 after modeling for 30 day. Paw swelling, arthritic index (AI), cardiac function indexes and myocardial pathological pattern were detected. The expression of TLR4, myeloid differentiation factor (MyD) 88, interleukin-1 receptor-associated kinase (IRAK) 1, tumor necrosis factor receptor associated factor (TRAF) 6, NF-κB, tumor necrosis factor-alpha (TNF-α) proteins in myocardial tissue were determined by western blot method. RESULTS: Paw swelling and AI in MC group increased in MC group (P < 0.01), and decreased in high and moderate dose XFC groups (P < 0.01 or P > 0.05). Left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), heart rate (HR) were elevated in MC group (P < 0.01), and ± dp/dtmax and CI were reduced (P < .01); while LVSP, LVEDP and HR declined and ±dp/ dtmax, CI improved in high dose XFC group (P < 0.05 or P < 0.01). LVSP in high dose XFC group were reduced more than other treatment groups (P < 0.05 or P < 0.01). The improvements on LVEDP, dp/ dt-max were superior to MTX and low dose XFC group, and the improvement on CI was better than low dose XFC group (P < 0.05 or P < 0.01). Myocardial fibers arranged irregular in MC group with intracellular edema and mitochondria damage. The modifications on myocardial structural were shown in each treatment group, but more prominent in TPT, high and moderate dose XFC group. The proteins of TLR4, MyD88, IRAK1, TRAF6, NF-κB, TNF-α were highly expressed in MC group, and those proteins declined in high and moderate dose XFC group (P < 0.05 or P < 0.01). High dose XFC group was superior to MTX and low dose XFC group on reducing TLR4, NF-κB, TNF-α (P < 0.05). CONCLUSION: XFC can not only inhibit the excessive activation of TLR4/NF-κB signaling pathway and the increased inflammatory mediators, but also reduce the damage of myocardial tissue and cells.

Insulin resistance, neuroinflammation, and Alzheimer's disease.

Alzheimer's disease (AD) is the most common form of dementia. Pathologically, it is characterized by degeneration of neurons and synapses, the deposition of extracellular plaques consisting of aggregated amyloid-ß (Aß) peptides, and intracellular neurofibrillary tangles made up of hyperphosphorylated tau protein. Recently, the spotlights have been centered on two characteristics of AD, neuroinflammation and insulin resistance. Because both of these pathways play roles in synaptic dysfunction and neurodegeneration, they become potential targets for therapeutic intervention that could impede the progression of the disease. Here, we present an overview of the traditional amyloid hypothesis, as well as emerging data on both inflammatory and impaired insulin signaling pathways in AD. It becomes evident that more than one concurrent treatment can be synergistic and various combinations should be discussed as a potential therapeutic strategy to correct the anomalies in AD. Insulin resistance, Aß/tau pathologies, neuroinflammation, and dysregulation of central nervous system homeostasis are intertwined processes that together create the complex pathology of AD and should be considered as a whole picture.

Use of xinfeng capsule to treat abarticular pathologic changes in patients with rheumatoid arthritis.

OBJECTIVE: To observe the influence of Xinfengcapsule (XFC) on abarticular pathologic changes (APCs) and other indices of patients with rheumatoid arthritis (RA) and explore the mechanism of action of XFC in improving such changes. METHODS: Three-hundred RA patients were divided randomly into a treatment group (n = 150) and control group (n = 150). A normal control (NC) group (n = 90) was also created. Changes in cardiac function, pulmonary function, anemia indices and platelet parameters of RA patients were measured. Curative effects of the two groups were compared, and comparison carried out with the NC group. RESULTS: In 300 RA patients, late diastolic peak flow velocity (A peak) was much higher (P < 0.01) and early diastolic peak flow velocity (E peak), E/A, and left ventricular fraction shortening much lower(P < 0.01) than those in the NC group. Vital capacity (VC), forced vital capacity in one second, forced vitalcapacity (FVC), maximal voluntary ventilation (MVV), maximal expiratory flow in 50% of VC (FEF50) and FEF75 were lowered remarkably (P < 0.05 or P < 0.01). Platelet count (PLT), plateletcrit (PCT) and mean platelet volume (MPV) increased markedly (P < 0.05 or P < 0.01), and hemoglobin (Hb) level decreased significantly (P < 0.05). After XFC treatment, the A peak and PLT and PCT were much lower (P < 0.05), and E/A and the number of red blood cells as well as Hb level were much higher (P < 0.05), as were FVC, MVV and FEF50 (P < 0.05 or P < 0.01), in the treatment group than those in the NC group. Total score of pain and swelling in joints, uric-acid level and high-sensitivity C-reactive protein level were much lower, and superoxide dismutase level as well as the number of CD4 + CD25+ regulation T cells (Treg) and CD4+ CD25+ CD127- Treg were much higher (P < 0.05 or P < 0.01) in the treatment group than those in the NC group. CONCLUSION: RA patients with pathologic changes in joints also suffer from lower cardiac and pulmonary functions and from parameters of anemia and platelet factors. XFC can improve the symptoms of RA patients, ameliorate their cardiac and pulmonary functions and reduce the parameters of anemia and platelet factors. XFC lowers the immune inflammatory reaction to improve APCs in RA patients.

Semi-Covariance Coefficient Analysis of Spike Proteins from SARS-CoV-2 and Its Variants Omicron, BA.5, EG.5, and JN.1 for Viral Infectivity, Virulence and Immune Escape.

Semi-covariance has attracted significant attention in recent years and is increasingly employed to elucidate statistical phenomena exhibiting fluctuations, such as the similarity or difference in charge patterns of spike proteins among coronaviruses. In this study, by examining values above and below the average/mean based on the positive and negative charge patterns of amino acid residues in the spike proteins of SARS-CoV-2 and its current circulating variants, the proposed methods offer profound insights into the nonlinear evolving trends in those viral spike proteins. Our study indicates that the charge span value can predict the infectivity of the virus and the charge density can estimate the virulence of the virus, and both predicated infectivity and virulence appear to be associated with the capability of viral immune escape. This semi-covariance coefficient analysis may be used not only to predict the infectivity, virulence and capability of immune escape for coronaviruses but also to analyze the functionality of other viral proteins. This study improves our understanding of the trend of viral evolution in terms of viral infectivity, virulence or the capability of immune escape, which remains further validated by more future studies and statistical data.

sTREM2 Differentially Affects Cytokine Expression in Myeloid-Derived Cell Models via MAPK-JNK Signaling Pathway.

TREM2 is a critical innate immune receptor primarily expressed on myeloid-derived cells, such as microglia and macrophages. Mutations in TREM2 are linked to several neurodegenerative diseases including Alzheimer's disease (AD). TREM2 can be cleaved from the cell membrane and released as soluble TREM2 (sTREM2). sTREM2 levels are shown to peak prior to AD, with its levels fluctuating throughout disease progression. However, the mechanism by which sTREM2 may affect innate immune responses is largely uncharacterized. In this study, we investigated whether sTREM2 can induce inflammatory response in myeloid-derived THP-1 monocytes and macrophages and characterized the signaling mechanisms involved. Our results show that sTREM2 was capable of stimulating the expression of several inflammatory cytokines in THP-1 cells throughout the time course of 2 h to 8 h but inducing anti-inflammatory cytokine expression at later time points. A TREM2 antibody was capable of inhibiting the expression of some cytokines induced by sTREM2 but enhancing others. The complex of sTREM2/TREM2 antibody was shown to enhance IL-1ß expression, which was partially blocked by an NLRP3 specific inhibitor, indicating that the complex activated the NRLP3 inflammasome pathway. sTREM2 was also shown to have differential effects on cytokine expression in M0, M1, and M2 macrophages differentiated from THP-1 cells. sTREM2 has a more stimulating effect on cytokine expression in M0 macrophages, less of an effect on M2 macrophages, and some inhibitory effects on cytokine expression in M1 macrophages at early time points. Analyses of several signaling pathways revealed that sTREM2-induced expression of cytokines occurs mainly through MAPK-JNK signaling. Our work reveals differential effects of sTREM2 on cytokine expression profiles of THP-1 cells and macrophages and demonstrates that the MAPK-JNK signaling pathway is mainly responsible for sTREM2-induced cytokine expression.

[Differentially expressed microRNAs in peripheral blood mononuclear cells of ankylosing spondylitis patients and its correlation with immune inflammatory response].

Objective To investigate the differentially expressed miRNAs in peripheral blood mononuclear cells (PBMCs) of ankylosing spondylitis (AS) patients, and explore its relevance with the immune inflammatory responses. Methods Fifteen AS patients (AS group) and fifteen healthy volunteers (control group) were recruited in this research. High-throughput RNA sequencing was used to screen miRNA expression in PBMCs. Real-time quantitative PCR was used to detect the six differentially expressed miRNAs. ELISA was applied to test the levels of proinflammatory cytokines, such as TNF-α, IL-1ß, IL-17, and IL-23. Finally, Spearman correlation analysis was conducted to study the correlations of differentially expressed miRNAs with disease activity indicators and immune inflammatory markers. Results Forty-four miRNAs were significantly differentially expressed in AS patients, manifested as 22 up-regulated and 22 down-regulated (fold change≥1). Among them, miR-1-3p and miR-133a-5p were up-regulated obviously, while miR-127-5p, miR-345-3p and miR-136-3p were down-regulated significantly. TNF-α, IL-1ß, IL-17 and IL-23 were significantly increased simultaneously in AS patients. Moreover, miR-1-3p was positively correlated with TNF-α, CRP and BASDAI score; miR-133a-5p was positively correlated with TNF-α; miR-127-5p was negatively correlated with ESR and VAS; miR-345-3p was negatively correlated with IL-17; miR-136-3p was negatively correlated with IL-17 and BASDAI score. Conclusion The miRNAs are abnormally expressed in PBMCs of AS patients, and the differentially expressed miRNAs are associated with disease activity indicators and immune inflammatory cytokines.

[Treatment of rheumatoid arthritis by xinfeng capsule: an efficacy observation].

OBJECTIVE: To observe the curative effect of Xinfeng Capsule (XC) in treatment of rheumatoid arthritis (RA). METHODS: Recruited were 80 active RA patients, who were randomly assigned to the normal control group and the treatment group, 40 in each group. All patients received the same routine anti-rheumatic treatment: Methotrexate 10 mg per week; Diclofenac 50 mg when pain was obvious, twice daily. Patients in the treatment group took XC 3 tablets each time, thrice daily. All treatment lasted for 12 consecutive weeks. Serum iron (SI), serum ferritin (SF), transferrin (TRF); and RA disease activity index (DAS-28) were detected in all patients. RESULTS: XC could improve HAQ, DAS-28, hypersensitive C reactive protein (hs-CRP), prostaglandins A (PGA), erythrocyte sedimentation rate (ESR), number of swelling joints, number of tender joints, and morning stiffness time in acute RA patients, showing statistical difference when compared with those of the control group (P < 0.01, P < 0.05). Compared with the control group, SI, SF, DAS-28, and TRF significantly decreased in the treatment group (P < 0.05). CONCLUSION: XC could improve DAS-28, and SI reserve in patients with active RA, and lower DAS-28 related indicators.

[Effect of Xinfeng Capsule on lung function in rats with adjuvant-induced arthritis and its mechanism].

OBJECTIVE: To investigate the effects of Xinfeng Capsule (XFC) on pulmonary function and related mechanism in adjuvant-induced arthritis (AA) rats. METHODS: The rats were randomly divided into five groups: normal control (NC), model control (MC) groups, methotrexate (MTX), tripterygium glycosides tablet (TPT) and Xinfeng capsule (XFC) treatment groups. The adjuvant-induced arthritis model was established by intracutaneous injection of 0.1 mL Freund ' s complete adjuvant in the right paw of rats; the drugs were given 19 d after model establishment. The toe swelling degree (E), arthritis index (AI), pulmonary function, peripheral blood Treg levels, pathological changes of lung tissue and expression of Foxp3, TGF-ß1, Smad3, Smad7 proteins in lung tissue were measured 30 d after drug administration. RESULTS: Compared to NC group, the levels of E, AI, alveolitis score, TGF-ß1 and Smad3 were significantly increased (P <0.05 or P <0.01); maximum expiratory flow 25% of vital capacity (FEF25),50% maximal expiratory vital capacity flow (FEF50), maximum expiratory flow at 75% of vital capacity (FEF75), maximum mid-expiratory flow (MMF), force peak expiratory flow (PEF), CD4+ CD25+ Treg, Foxp3 and Smad7 were significantly decreased in MC group (P <0.05 or P < 0.01). Compared to MC group,the expression of E, AI, TGF-ß1 and Smad3 were reduced, while FEF50, FEF75, MMF, PEF, Treg, Foxp3 and Smad7 were elevated in XFC group (P <0.05 or P <0.01). Compared to XFC group, the level of body mass,FEF25,FEF50, FEF75, MMF and Treg were lower in MTX and TPT groups (P <0.05 or P <0.01). CONCLUSION: There are inflamed joints and reduced pulmonary function in rats of adjuvant-induced arthritis. XFC can inhibit paw edema degrees, reduce arthritis response, and improve pulmonary function, which is associated with up-regulating expression of Treg and Foxp3, down-regulating the expression of TGF-ß1 and adjusting TGF-ß1/Smads signal pathway.

Semisupervised Manifold Regularization via a Subnetwork-Based Representation Learning Model.

Semisupervised classification with a few labeled training samples is a challenging task in the area of data mining. Moore-Penrose inverse (MPI)-based manifold regularization (MR) is a widely used technique in tackling semisupervised classification. However, most of the existing MPI-based MR algorithms can only generate loosely connected feature encoding, which is generally less effective in data representation and feature learning. To alleviate this deficiency, we introduce a new semisupervised multilayer subnet neural network called SS-MSNN. The key contributions of this article are as follows: 1) a novel MPI-based MR model using the subnetwork structure is introduced. The subnet model is utilized to enrich the latent space representations iteratively; 2) a one-step training process to learn the discriminative encoding is proposed. The proposed SS-MSNN learns parameters by directly optimizing the entire network, accepting input from one end, and producing output at the other end; and 3) a new semisupervised dataset called HFSWR-RDE is built for this research. Experimental results on multiple domains show that the SS-MSNN achieves promising performance over the other semisupervised learning algorithms, demonstrating fast inference speed and better generalization ability.

Hierarchical One-Class Model With Subnetwork for Representation Learning and Outlier Detection.

The multilayer one-class classification (OCC) frameworks have gained great traction in research on anomaly and outlier detection. However, most multilayer OCC algorithms suffer from loosely connected feature coding, affecting the ability of generated latent space to properly generate a highly discriminative representation between object classes. To alleviate this deficiency, two novel OCC frameworks, namely: 1) OCC structure using the subnetwork neural network (OC-SNN) and 2) maximum correntropy-based OC-SNN (MCOC-SNN), are proposed in this article. The novelties of this article are as follows: 1) the subnetwork is used to build the discriminative latent space; 2) the proposed models are one-step learning networks, instead of stacking feature learning blocks and final classification layer to recognize the input pattern; 3) unlike existing works which utilize mean square error (MSE) to learn low-dimensional features, the MCOC-SNN uses maximum correntropy criterion (MCC) for discriminative feature encoding; and 4) a brand-new OCC dataset, called CO-Mask, is built for this research. Experimental results on the visual classification domain with a varying number of training samples from 6131 to 513 061 demonstrate that the proposed OC-SNN and MCOC-SNN achieve superior performance compared to the existing multilayer OCC models. For reproducibility, the source codes are available at https://github.com/W1AE/OCC.

Differential Expression of ABC Transporter Genes in Brain Vessels vs. Peripheral Tissues and Vessels from Human, Mouse and Rat.

BACKGROUND: ATP-binding cassette (ABC) transporters comprise a superfamily of genes encoding membrane proteins with nucleotide-binding domains (NBD). These transporters, including drug efflux across the blood-brain barrier (BBB), carry a variety of substrates through plasma membranes against substrate gradients, fueled by hydrolyzing ATP. The expression patterns/enrichment of ABC transporter genes in brain microvessels compared to peripheral vessels and tissues are largely uncharacterized. METHODS: In this study, the expression patterns of ABC transporter genes in brain microvessels, peripheral tissues (lung, liver and spleen) and lung vessels were investigated using RNA-seq and WesTM analyses in three species: human, mouse and rat. RESULTS: The study demonstrated that ABC drug efflux transporter genes (including ABCB1, ABCG2, ABCC4 and ABCC5) were highly expressed in isolated brain microvessels in all three species studied; the expression of ABCB1, ABCG2, ABCC1, ABCC4 and ABCC5 was generally higher in rodent brain microvessels compared to those of humans. In contrast, ABCC2 and ABCC3 expression was low in brain microvessels, but high in rodent liver and lung vessels. Overall, most ABC transporters (with the exception of drug efflux transporters) were enriched in peripheral tissues compared to brain microvessels in humans, while in rodent species, additional ABC transporters were found to be enriched in brain microvessels. CONCLUSIONS: This study furthers the understanding of species similarities and differences in the expression patterns of ABC transporter genes; this is important for translational studies in drug development. In particular, CNS drug delivery and toxicity may vary among species depending on their unique profiles of ABC transporter expression in brain microvessels and BBB.

Abcg2 deficiency augments oxidative stress and cognitive deficits in Tg-SwDI transgenic mice.

Oxidative stress and neuroinflammation play important roles in Alzheimer's disease (AD). ABCG2 is a transporter protein expressed in the brain and involved in GSH transport. To study the roles of Abcg2 in oxidative stress and AD, we cross-bred Tg-SwDI and Abcg2-KO mice and generated Tg-SwDI/Abcg2-KO (double-tg) mice. Brain tissues from double-tg, Tg-SwDI, wild-type, and Abcg2-KO mice at various ages were analyzed. Aß40 and Aß42 were detected in Tg-SwDI and double-tg mice. Total brain GSH was decreased and levels of lipid/DNA oxidation were increased in 3-month double-tg compared to Tg-SwDI mice. Low brain GSH was still detected in 9-month double-tg mice. Increased HMOX-1 and MCP-5 expression was observed in 9-month double-tg mice but not in Tg-SwDI mice compared to WT and Abcg2-KO mice. Increased HMOX-1 and decreased ICAM-1 expression were observed in 12-month double-tg mice compared to Tg-SwDI mice. The levels of Nrf-2 expression and activity were decreased in 6-month double-tg mice. Behavioral tests show impaired cognitive/memory performance of 9-month double-tg compared to Tg-SwDI mice as well as WT and Abcg2-KO mice. These results suggest that Abcg2 deficiency increases oxidative stress and alters inflammatory response in the brain and exacerbates cognitive/memory deficit in double-tg mice at different developmental stages.

Effects of xinfeng capsule on pulmonary function based on treg-mediated notch pathway in a rat model of adjuvant arthritis.

OBJECTIVE: To observe the impact of xinfeng xapsule (XFC) on pulmonary function in a rat model of adjuvant arthritis (AA) and to investigate the mechanism of action. METHODS: Forty rats were randomly divided into four groups of ten: normal control (NC); model control (MC); tripterygium glycosides tablet (TPT); and xinfeng capsule (XFC). Except for the NC group, AA was induced in all rats by intracutaneous injection of 0.1 mL Freund's complete adjuvant in the right paw on the 19th day. NC and MC groups were given (0.9%) physiological saline. The TPT and XFC groups were given TPT (10 mg/kg) and XFC (1.2 g/ kg), respectively. Thirty days after administration, changes in paw edema (E), the arthritis index (AI), pulmonary function, levels of regulatory T-cells (Treg), ultrastructure of lung tissue, and expression of Notch receptors and ligands in lung tissue were observed. RESULTS: In the MC group, E and the AI were increased and pulmonary function significantly decreased; the structure of alveolar type-III cells was damaged; ratios ofTreg in peripheral blood were reduced; and expression of Notch receptors such as Notch3 and Notch4 and ligands such as Deltal in lung tissue were significantly increased whereas expression of Notch1, Jagged 1 and Jagged2 were significantly decreased. After intervention with XFC, E and the AI were decreased; pulmonary function was enhanced; the structure of alveolar type-II cells was improved; and expression of Treg, Notch1, Jagged1, Jagged2 was elevated, whereas that of Notch3, Notch4 and Delta1 was reduced. CONCLUSION: XFC can not only inhibit E and the AI and improve joint symptoms, it can also improve pulmonary function and reduce inflammation in lung tissue. These actions could be carried out through increases in the expression of Treg, Notch receptors (Notch1) and ligands (Jagged1, Jagged2), and reductions in the expression of Notch3, Notch4 and Delta1. These phenomena would reduce the deposition of immune complexes and the inflammatory response in lung tissue, thereby improving joint symptoms and pulmonary function.

Differentiation of Human Induced Pluripotent Stem Cells (hiPSC) into Endothelial-Type Cells and Establishment of an In Vitro Blood-Brain Barrier Model.

Development of central nervous system (CNS) therapeutics and their brain delivery is impeded by the presence of the blood-brain barrier (BBB). In vitro BBB models, in particular human in vitro BBB models, are critical tools for CNS drug research and development. However, the availability of primary human microvascular endothelial cells is very limited for in vitro modeling. Advances in human induced pluripotent stem cell (hiPSC) technologies provide reproducible human cell resources for scientific research, regenerative medicine, and in vitro modeling. In particular, the differentiation of hiPSC into brain endothelial cells provides scalable, renewable and unlimited cells for in vitro BBB modeling that enables rapid screening of CNS drugs in terms of their BBB permeability. The following protocols provide a general guideline for hiPSC culture, differentiation of hiPSC into endothelial cells (hiPSC-ECs), generation of rat primary astrocytes, and establishment of a two-chamber co-culture in vitro BBB model.