PR-957 retards rheumatoid arthritis progression and inflammation by inhibiting LMP7-mediated CD4+ T cell imbalance.

OBJECTIVE: Low molecular mass polypeptide 7 (LMP7) is an immunoproteasome subunit that regulates T cell amplification, differentiation, and inflammation and is involved in rheumatoid arthritis (RA) progression. This study intended to apply PR-957 (an anti-LMP7 agent) for RA treatment in vitro and in vivo and evaluate its interaction with LMP7-mediated CD4+ T cell imbalance. METHODS: Peripheral blood mononuclear cells (PBMCs) were obtained from 30 RA patients and 30 healthy controls. RA fibroblast-like synoviocytes (RA-FLSs) and CD4+ T cells were isolated from RA patients and then cocultured with PR-957 and/or LMP7 overexpression adenovirus (Ad-LMP7). Collagen-induced arthritis (CIA) mice were constructed and then treated with PR-957 and/or Ad-LMP7. RESULTS: LMP7 was higher in RA patients (versus healthy controls) and positively correlated with T helper (Th)1 cells, the Th1/Th2 ratio, Th17 cells, and the Th17/Treg ratio but not with Th2 or T regulatory (Treg) cells. PR-957 reduced Th1 and Th17 cells but increased Th2 and Treg cells in RA-CD4+ T cells, and this effect was partially reversed by Ad-LMP7 transfection. Interestingly, when cocultured with RA-CD4+ T cells, PR-957 increased RA-FLS apoptosis and decreased its invasive ability, viability, and inflammation, as suggested by IL-6, CCL2, MMP1, and MMP3; however, these phenomena were weakened in RA-FLSs without RA-CD4+ T cell coculture. In addition, Ad-LMP7 transfection attenuated the above effects of PR-957. In CIA mice, PR-957 decreased the arthritis score, synovial hyperproliferation and articular injury, inflammation in the synovium and serum, and the imbalance of Th1/Th2 and Th17/Treg in the spleen, and these effects were attenuated by Ad-LMP7. CONCLUSION: PR-957 ameliorates RA progression and inflammation by repressing LMP7-mediated CD4+ T cell imbalance.

The implication of long non-coding RNA expression profile in rheumatoid arthritis: Correlation with treatment response to tumor necrosis factor inhibitor.

OBJECTIVE: This study aimed to investigate the linkage of long non-coding RNA (lncRNA) expression profile with etanercept response in rheumatoid arthritis (RA) patients. METHODS: Peripheral blood mononuclear cell (PBMC) samples were collected from 80 RA patients prior to etanercept treatment. Samples from eight responders and eight non-responders at week 24 (W24) were proposed to RNA-sequencing, then 10 candidate lncRNAs were sorted and their PBMC expressions were validated by reverse transcription quantitative chain reaction (RT-qPCR) in 80 RA patients. Subsequently, clinical response by lncRNA (CRLnc) prediction model was established. RESULTS: RNA-sequencing identified 254 up-regulated and 265 down-regulated lncRNAs in W24 responders compared with non-responders, which were enriched in immune or joint related pathways such as B-cell receptor signaling, osteoclast differentiation and T-cell receptor signaling pathways, etc. By reverse transcription quantitative chain reaction (RT-qPCR) validation: Two lncRNAs were correlated with W4 response, three lncRNAs were correlated with W12 response, seven lncRNAs were correlated with W24 response. Subsequently, to construct and validate CRLnc prediction model, 80 RA patients were randomly divided into test set (n = 40) and validation set (n = 40). In the test set, lncRNA RP3-466P17.2 (OR = 9.743, P = .028), RP11-20D14.6 (OR = 10.935, P = .007), RP11-844P9.2 (OR = 0.075, P = .022), and TAS2R64P (OR = 0.044, P = .016) independently related to W24 etanercept response; then CRLnc prediction model integrating these four lncRNAs presented a good value in predicting W24 etanercept response (Area Under Curve (AUC): 0.956, 95%CI: 0.896-1.000). However, in the validation set, the CRLnc prediction model only exhibited a certain value in predicting W24 etanercept response (AUC: 0.753, 95%CI: 0.536-0.969). CONCLUSIONS: CRLnc prediction model is potentially a useful tool to instruct etanercept treatment in RA patients.

Mechanisms of ketamine on mice hippocampi shown by gas chromatography-mass spectrometry-based metabolomic analysis.

In the present study, we used a gas chromatography-mass spectrometry-based metabolomics method to evaluate the effects of ketamine on mice hippocampi. Multivariate statistical analysis and ingenuity pathway analysis were then used to identify and explore the potential mechanisms and biofunction of ketamine. Compared with the control (CON) group, 14 differential metabolites that involved amino acid metabolism, energy metabolism, and oxidative stress metabolism were identified. After combination with 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione (NBQX) administration, six of the 14 metabolites remained significantly differentially expressed between the ketamine (KET) and KET+NBQX groups, including glycine, alanine, glutamine, aspartic acid, myoinositol, and ascorbate, whereas no difference was found in the levels of the other eight metabolites between the KET and KET+NBQX groups, including phosphate, 4-aminobutyric acid, urea, creatine, L-malic acid, galactinol, inosine, and aminomalonic. Our findings indicate that ketamine exerts antidepressant effects through an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid inhibition-dependent mechanism and a mechanism not affected by α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid inhibition. Which provides further insight into the therapeutic mechanisms of ketamine in the hippocampus.

Up-regulation of SIRT6 in the hippocampus induced rats with depression-like behavior via the block Akt/GSK3ß signaling pathway.

Major depression is the leading cause of disability worldwide, which is associated with diverse alterations in brain such as neuro-inflammation, synaptic dysfunction, and cognitive deficit. Accumulating evidences suggest sirtuins (SIRTs) are involved in brain developmental disorders, metabolic diseases and play a key role in cognition and synaptic plasticity, yet the role in mood regulation remains controversial. Hence, Western blotting and RT-qPCR were used to investigate whether SIRTs (SIRT1-7) expression levels were altered in the hippocampus of rats, which followed 5 weeks of chronic unpredictable mild stress (CUMS) treatment, the results showed depressive-like behaviors: like body weight, forced swim test and sucrose preference test and SIRT6 was a significant increase in the hippocampal of CUMS rats. Furthermore, via a lentivirus-mediated transfection in hippocampal neurons, we aimed to detect how SIRT6 influence the function of hippocampus. The SIRT6 overexpression significantly inhibited expressions of proteins and/or phosphoproteins (e.g AKT, p-AKT, P-GSK3ß), decreased the ratios of p-GSK3ß/GSK3ß and p-Akt/Akt in the primary hippocampus neurons. Thus, our data indicates that SIRT6 is involved in the modulation of depressive-like behaviors and affects the survival and synaptic plasticity of hippocampal neuron via inhibitory activation of Akt-GSK3ß signaling.

Versatile Miniature Tunable Liquid Lenses Using Transparent Graphene Electrodes.

This paper presents, for the first time, versatile and low-cost miniature liquid lenses with graphene as electrodes. Tunable focal length is achieved by changing the droplet curvature using electrowetting on dielectric (EWOD). Ionic liquid and KCl solution are utilized as lens liquid on the top of a flexible Teflon-coated PDMS/parylene membrane. Transparent and flexible, graphene allows transmission of visible light as well as large deformation of the polymer membrane to achieve requirements for different lens designs and to increase the field of view without damaging of electrodes. The tunable range for the focal length is between 3 and 7 mm for a droplet with a volume of 3 µL. The visualization of bone marrow dendritic cells is demonstrated by the liquid lens system with a high resolution (456 lp/mm).

Laser-induced cavitation in nanoemulsion with gold nanospheres for blood clot disruption: in vitro results.

Optically activated cavitation in a nanoemulsion contrast agent is proposed for therapeutic applications. With a 56°C boiling point perfluorohexane core and highly absorptive gold nanospheres at the oil-water interface, cavitation nuclei in the core can be efficiently induced with a laser fluence below medical safety limits (70 mJ/cm2 at 1064 nm). This agent is also sensitive to ultrasound (US) exposure and can induce inertial cavitation at a pressure within the medical diagnostic range. Images from a high-speed camera demonstrate bubble formation in these nanoemulsions. The potential of using this contrast agent for blood clot disruption is demonstrated in an in vitro study. The possibility of simultaneous laser and US excitation to reduce the cavitation threshold for therapeutic applications is also discussed.

Can molecular imaging enable personalized diagnostics? An example using magnetomotive photoacoustic imaging.

The advantages of photoacoustic (PA) imaging, including low cost, non-ionizing operation, and sub-mm spatial resolution at centimeters depth, make it a promising modality to probe nanoparticle-targeted abnormalities in real time at cellular and molecular levels. However, detecting rare cell types in a heterogeneous background with strong optical scattering and absorption remains a big challenge. For example, differentiating circulating tumor cells in vivo (typically fewer than 10 cells/mL for an active tumor) among billions of erythrocytes in the blood is nearly impossible. In this paper, a newly developed technique, magnetomotive photoacoustic (mmPA) imaging, which can greatly increase the sensitivity and specificity of sensing targeted cells or molecular interactions, is reviewed. Its primary advantage is suppression of background signals through magnetic enrichment/manipulation with simultaneous PA detection of magnetic contrast agent targeted objects. Results from phantom and in vitro studies demonstrate the capability of mmPA imaging to differentiate regions targeted with magnetic nanoparticles from the background, and to trap and sensitively detect targeted cells at a concentration of a single cell per milliliter in a flow system mimicking a human peripheral artery. This technique provides an example of the ways in which molecular imaging can potentially enable robust molecular diagnosis and treatment, and accelerate the translation of molecular medicine into the clinic.

Magnetomotive photoacoustic imaging: in vitro studies of magnetic trapping with simultaneous photoacoustic detection of rare circulating tumor cells.

Photoacoustic (PA) imaging has been demonstrated to be a promising modality in molecular imaging for detection of nanoparticle-targeted diseased cells or tissues. However, intrinsic absorbers, such as blood, produce strong PA background signals that severely degrade the detection sensitivity and specificity of targeted objects. Magnetomotive photoacoustic (mmPA) imaging, a newly developed molecular imaging modality, introduced dynamic manipulation into traditional PA imaging. Unlike conventional PA imaging, magnetomotive manipulation with simultaneous ultrasound/PA imaging of agents incorporating magnetic nanoparticles enables direct visualization of the signal generating object and can dramatically reduce background signals from strong optical absorbers. This paper briefly reviews recent developments in mmPA imaging, including uses of composite contrast agent, design of magnet system, and data processing for motion filtering. The use of mmPA imaging in detecting rare circulating tumor cells in blood vessels, which remains a big challenge for real-time in vivo examination using current methodologies, was also addressed.

Trapping and dynamic manipulation of polystyrene beads mimicking circulating tumor cells using targeted magnetic/photoacoustic contrast agents.

Results on magnetically trapping and manipulating micro-scale beads circulating in a flow field mimicking metastatic cancer cells in human peripheral vessels are presented. Composite contrast agents combining magneto-sensitive nanospheres and highly optical absorptive gold nanorods were conjugated to micro-scale polystyrene beads. To efficiently trap the targeted objects in a fast stream, a dual magnet system consisting of two flat magnets to magnetize (polarize) the contrast agent and an array of cone magnets producing a sharp gradient field to trap the magnetized contrast agent was designed and constructed. A water-ink solution with an optical absorption coefficient of 10 cm⁻¹ was used to mimic the optical absorption of blood. Magnetomotive photoacoustic imaging helped visualize bead trapping, dynamic manipulation of trapped beads in a flow field, and the subtraction of stationary background signals insensitive to the magnetic field. The results show that trafficking micro-scale objects can be effectively trapped in a stream with a flow rate up to 12 ml/min and the background can be significantly (greater than 15 dB) suppressed. It makes the proposed method very promising for sensitive detection of rare circulating tumor cells within high flow vessels with a highly absorptive optical background.

Suppression of background signal in magnetomotive photoacoustic imaging of magnetic microspheres mimicking targeted cells.

Contrast-enhanced photoacoustic (PA) imaging has been proposed to identify circulating metastatic cancer cells magnetically trapped in the vasculature. However, its sensitivity is limited by the presence of a strong blood-background signal. This technique can be further improved by the significant suppression of blood background. In the phantom study presented here, significant background suppression is demonstrated with magnetomotive photoacoustic imaging. Magnetic particles with a mean diameter of 10 µm were integrated (concentration of 0.05 mg/ml) into an ink-water solution with an optical absorption coefficient of 5 cm(-1) to mimic cells targeted with magnetic nanoparticles and magnetically trapped in the human vasculature. Two mechanically moveable permanent magnets were used to accumulate microparticles in the investigated solution and manipulate them within a thin, 1.6-mm-diameter Teflon tube mimicking a blood vessel. Our results clearly indicate that the undesirable background can be effectively suppressed using the difference of PA images corresponding to different locations of accumulated particles.