Supercurrent, Multiple Andreev Reflections and Shapiro Steps in InAs Nanosheet Josephson Junctions.

We report an experimental study of proximity induced superconductivity in planar Josephson junction devices made from free-standing InAs nanosheets. The nanosheets are grown by molecular beam epitaxy, and the Josephson junction devices are fabricated by directly contacting the nanosheets with superconductor Al electrodes. The fabricated devices are explored by low-temperature carrier transport measurements. The measurements show that the devices exhibit a gate-tunable supercurrent, multiple Andreev reflections, and a good quality superconductor-semiconductor interface. The superconducting characteristics of the Josephson junctions are investigated at different magnetic fields and temperatures and are analyzed based on the Bardeen-Cooper-Schrieffer (BCS) theory. The measurements of the ac Josephson effect are also conducted under microwave radiations with different radiation powers and frequencies, and integer Shapiro steps are observed. Our work demonstrates that InAs nanosheet based hybrid devices are desired systems for investigating the forefront of physics, such as two-dimensional topological superconductivity.

Tuning Edge States in Strained-Layer InAs/GaInSb Quantum Spin Hall Insulators.

We report on a class of quantum spin Hall insulators (QSHIs) in strained-layer InAs/GaInSb quantum wells, in which the bulk gaps are enhanced up to fivefold as compared to the binary InAs/GaSb QSHI. Remarkably, with consequently increasing edge velocity, the edge conductance at zero and applied magnetic fields manifests time reversal symmetry-protected properties consistent with the Z_{2} topological insulator. The InAs/GaInSb bilayers offer a much sought-after platform for future studies and applications of the QSHI.

The molecular events involved in oligodendrocyte precursor cell proliferation induced by the conditioned medium from b104 neuroblastoma cells.

The conditioned medium from B104 neuroblastoma cells (B104CM) induces proliferation of oligodendrocyte progenitor cells (OPCs) in vitro. However, the molecular events that occur during B104CM-induced proliferation of OPCs has not been well clarified. In the present study, using OPCs immunopanned from embryonic day 14 Sprague-Dawley rat spinal cords, we explored the activation of several signaling pathways and the expression of several important immediate early genes (IEGs) and cyclins in OPCs in response to B104CM. We found that B104CM can induce OPC proliferation through the activation of the extracellular signal-regulated kinases 1 and 2 (Erk1/2), but not PI3K or p38 MAPK signaling pathways in vitro. The IEGs involved in B104CM-induced OPC proliferation include c-fos, c-jun and Id2, but not c-myc, fyn, or p21. The cyclins D1, D2 and E are also involved in B104CM-stimulated proliferation of OPCs. The activation of Erk results in subsequent expression of IEGs (such as c-fos, c-jun and Id-2) and cyclins (including cyclin D1, D2 and E), which play key roles in cell cycle initiation and OPC proliferation. Collectively, these results suggest that the phosphorylation of Erk1/2 is an important molecular event during OPC proliferation induced by B104CM.

Selective targeting of GARP-LTGFß axis in the tumor microenvironment augments PD-1 blockade via enhancing CD8+ T cell antitumor immunity.

BACKGROUND: Immune checkpoint blockade (ICB) has revolutionized cancer immunotherapy. However, most patients with cancer fail to respond clinically. One potential reason is the accumulation of immunosuppressive transforming growth factor ß (TGFß) in the tumor microenvironment (TME). TGFß drives cancer immune evasion in part by inducing regulatory T cells (Tregs) and limiting CD8+ T cell function. Glycoprotein-A repetitions predominant (GARP) is a cell surface docking receptor for activating latent TGFß1, TGFß2 and TGFß3, with its expression restricted predominantly to effector Tregs, cancer cells, and platelets. METHODS: We investigated the role of GARP in human patients with cancer by analyzing existing large databases. In addition, we generated and humanized an anti-GARP monoclonal antibody and evaluated its antitumor efficacy and underlying mechanisms of action in murine models of cancer. RESULTS: We demonstrate that GARP overexpression in human cancers correlates with a tolerogenic TME and poor clinical response to ICB, suggesting GARP blockade may improve cancer immunotherapy. We report on a unique anti-human GARP antibody (named PIIO-1) that specifically binds the ligand-interacting domain of all latent TGFß isoforms. PIIO-1 lacks recognition of GARP-TGFß complex on platelets. Using human LRRC32 (encoding GARP) knock-in mice, we find that PIIO-1 does not cause thrombocytopenia; is preferentially distributed in the TME; and exhibits therapeutic efficacy against GARP+ and GARP- cancers, alone or in combination with anti-PD-1 antibody. Mechanistically, PIIO-1 treatment reduces canonical TGFß signaling in tumor-infiltrating immune cells, prevents T cell exhaustion, and enhances CD8+ T cell migration into the TME in a C-X-C motif chemokine receptor 3 (CXCR3)-dependent manner. CONCLUSION: GARP contributes to multiple aspects of immune resistance in cancer. Anti-human GARP antibody PIIO-1 is an efficacious and safe strategy to block GARP-mediated LTGFß activation, enhance CD8+ T cell trafficking and functionality in the tumor, and overcome primary resistance to anti-PD-1 ICB. PIIO-1 therefore warrants clinical development as a novel cancer immunotherapeutic.

REG4 is a Potential Biomarker for Radiochemotherapy Sensitivity in Colorectal Cancer.

PURPOSE: Colorectal cancer (CRC) is one of the most common types of malignancies, and radiochemotherapy (RCT) followed by surgery is the recommended approach for CRC treatment. However, some cases do not respond to first-line conventional chemotherapy or even progress further after treatment. Moreover, there is a risk of severe side effects, such as radiodermatitis. Therefore, identifying predictors for RCT sensitivity is an essential step toward predicting and eventually overcoming resistance. MATERIALS AND METHODS: We used integrative bioinformatics analysis and experimental validation to show that regenerating family member 4 (REG4) may be a potential biomarker for RCT sensitivity in CRC. RESULTS: REG4, whose expression is upregulated in some CRC tissues and downregulated in RCT-sensitive CRC cells, was identified as a potential genetic marker for RCT sensitivity in CRC. Immunohistochemistry-based tissue microarray of human CRC was used to experimentally validate REG4 data obtained from the bioinformatics analysis. CONCLUSION: Collectively, these results indicate that REG4 may be a potential biomarker for RCT sensitivity in CRC.

Nicotine self-administration differentially modulates glutamate and GABA transmission in hypothalamic paraventricular nucleus to enhance the hypothalamic-pituitary-adrenal response to stress.

The mechanisms by which chronic nicotine self-administration augments hypothalamo-pituitary-adrenal (HPA) responses to stress are only partially understood. Nicotine self-administration alters neuropeptide expression in corticotropin-releasing factor (CRF) neurons within paraventricular nucleus (PVN) and increases PVN responsiveness to norepinephrine during mild footshock stress. Glutamate and GABA also modulate CRF neurons, but their roles in enhanced HPA responsiveness to footshock during chronic self-administration are unknown. We show that nicotine self-administration augmented footshock-induced PVN glutamate release, but further decreased GABA release. In these rats, intra-PVN kynurenic acid, a glutamate receptor antagonist, blocked enhanced adrenocorticotropic hormone and corticosterone responses to footshock. In contrast, peri-PVN kynurenic acid, which decreases activity of GABA afferents to PVN, enhanced footshock-induced corticosterone secretion only in control rats self-administering saline. Additionally, in rats self-administering nicotine, footshock-induced elevation of corticosterone was significantly less than in controls after intra-PVN saclofen (GABA-B receptor antagonist). Therefore, the exaggerated reduction in GABA release by footshock during nicotine self-administration disinhibits CRF neurons. This disinhibition combined with enhanced glutamate input provides a new mechanism for HPA sensitization to stress by chronic nicotine self-administration. This mechanism, which does not preserve homeostatic plasticity, supports the concept that smoking functions as a chronic stressor that sensitizes the HPA to stress.

Tannin-immobilized cellulose hydrogel fabricated by a homogeneous reaction as a potential adsorbent for removing cationic organic dye from aqueous solution.

Tannin-immobilized cellulose (CT) hydrogels were successfully fabricated by homogeneous immobilization and crosslinking reaction via a simple method. The structures and properties of hydrogels were characterized by SEM and mechanical test. Methlyene Blue (MB) was selected as a cationic dye model, and the adsorption ability of CT hydrogel was evaluated. Tannins immobilized acted as adsorbent sites which combined MB by electrostatic attraction, resulting in the attractive adsorption ability of CT hydrogel. Adsorption kinetics could be better described by the pseudo-second-order model, and the absorption behaviors were in agreement with a Langmuir isotherm. The adsorption-desorption cycle of CT hydrogel was repeated six times without significant loss of adsorption capacity. In this work, both tannin immobilization and hydrogel formation were achieved simultaneously by a facile homogeneous reaction, providing a new pathway to fabricate tannin-immobilized materials for water treatment.

MicroRNA-93 alleviates neuropathic pain through targeting signal transducer and activator of transcription 3.

Emerging evidence suggests that microRNAs (miRNAs) play a critical role in the pathogenesis of neuropathic pain. However, the exact role of miRNAs in regulating neuropathic pain remains largely unknown. In this study, we aimed to investigate the potential role of miR-93 in a rat model of neuropathic pain induced by chronic constriction sciatic nerve injury (CCI). We found a significant decrease of miR-93 in the spinal cord of CCI rats compared with sham rats. Overexpression of miR-93 significantly alleviated neuropathic pain development and reduced inflammatory cytokine expression, including interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and IL-6 in CCI rats. By bioinformatic analysis and dual-luciferase reporter assay, we found that miR-93 directly targeted the 3'-untranslated region (UTR) of signal transducer and activator of transcription 3 (STAT3), an important regulator of inflammation. Overexpression of miR-93 markedly suppressed the expression of STAT3 in vitro and in vivo. Furthermore, overexpression of STAT3 significantly reversed the miR-93 overexpression-induced suppressive effects on neuropathic pain development and neuroinflammation. Taken together, our study suggests that miR-93 inhibits neuropathic pain development of CCI rats possibly through inhibiting STAT3-mediated neuroinflammation. Our findings indicate that miR-93 may serve as a novel therapeutic target for neuropathic pain intervention.

Aceclidine and pilocarpine interact differently with muscarinic receptor in isolated rabbit iris muscle.

The relationship between muscarinic receptor affinity states and the contractile response to the muscarinic agonists carbachol, aceclidine, and pilocarpine, has been examined in the isolated rabbit iris muscle. Contraction of the iris muscle by carbachol and aceclidine was more potent and/or more efficacious than the response to pilocarpine. Analysis of [3H]-Quinuclidinyl benzilate (QNB) binding showed that while both carbachol and aceclidine bound to high- and low-affinity forms of the muscarinic receptor, pilocarpine bound to one affinity state. The efficacy of carbachol and aceclidine to stimulate contraction of the iris muscle was consistent with receptor occupancy theory only when considering the low-affinity state of the muscarinic receptor, and activation of the low-affinity rather than high-affinity binding state of the receptor is likely to mediate the contraction of iris muscle. Therefore, the typical anti-glaucoma muscarinic agonists aceclidine and pilocarpine may interact differently with their target receptors in isolated rabbit iris muscle.

6beta-acetoxy nortropane regulated processing of amyloid precursor protein in CHOm1 cells and rat brain.

The effects of the muscarinic receptor agonist 6beta-acetoxy nortropane on amyloid precursor protein (APP) processing were studied in both transfected Chinese hamster ovary cells stably expressing muscarinic M(1) receptors (denoted as CHOm(1) cell line) and in cerebral cortical and hippocampal slices. Exposure of CHOm(1) cells to 6beta-acetoxy nortropane for 1 h significantly increased the secretion of secretory amyloid precursor protein (derived from alpha-secretase cleavage) in a concentration-dependent manner. In the same system, 6beta-acetoxy nortropane reduced the beta-amyloid peptide production. Similar results were obtained in hippocampal and cerebral cortical slices, with 6beta-acetoxy nortropane administration resulting in an increase in secretory amyloid precursor protein and a decrease in beta-amyloid peptide release. The increase of secretory amyloid precursor protein secretion was abolished by preincubation with selective muscarinic M(1) receptor antagonist pirenzepine, but not by preincubation with selective muscarinic M(2) receptor antagonist methoctramine, suggesting that 6beta-acetoxy nortropane promotes secretory amyloid precursor protein release in the brain via muscarinic M(1) receptor activation. These results suggest that 6beta-acetoxy nortropane could exert a beneficial effect on the progress of Alzheimer's disease by promoting amyloid precursor protein processing through alpha-secretase.

Simultaneous changes in secretory amyloid precursor protein and beta-amyloid peptide release from rat hippocampus by activation of muscarinic receptors.

Amyloid deposits in Alzheimer's disease (AD) are composed of beta-amyloid peptides (Abeta) that are derived from the larger amyloid precursor protein (APP). A number of studies with various transfected cell lines demonstrated that either APP secretion or Abeta production could be modulated by specific muscarinic receptor activation. In the present study, we investigated the simultaneous changes of neurotrophic secretory APP (APPs) and neurotoxic Abeta release from rat hippocampus by activation of muscarinic receptors. The treatment with carbachol (10 microM-1 mM) resulted in the increased APPs release and simultaneously reduced Abeta production from the hippocampus slices in a concentration-dependent manner. The carbachol-stimulated APPs release was blocked by the nonselective M antagonist atropine and the M(1) antagonist pirenzepine, but was not significantly affected by the M(2) antagonist methoctramine, demonstrating that APP processing was regulated mainly via M(1) receptor in the rat hippocampus. The effect of carbachol-stimulated APPs secretion was further verified in CHOm(1) cells stably expressing human muscarinic M(1) receptors. These data suggest that selective M(1) receptor agonists might execute a dual action of increasing APPs release and decreasing Abeta formation to modify the AD process.

Effects of histone deacetylase inhibition on the survival, proliferation and migration of Schwann cells, as well as on the expression of neurotrophic factors and genes associated with myelination.

Trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, has been shown to have neuroprotective, neurotrophic and anti-inflammatory properties in both animal and cellular models of neurodegenerative disorders. In a previous study of ours, we demonstrated that TSA inhibited the proliferation and increased the differentiation of neuronal precursor cells (NPCs). However, the effects of TSA on Schwann cells (SCs) have not yet been fully elucidated. Thus, in the present study, using SCs derived from adult rat sciatic nerves, we investigated the effects of TSA on the survival, proliferation, migration and myelination of SCs. We found that TSA significantly induced SC death when used at high concentrations. We also observed that TSA promoted the proliferation of SCs in a time-dependent manner. In addition, TSA inhibited the migration of SCs. Moreover, RT-PCR revealed that TSA increased the mRNA expression of several neurotrophic factors and inhibited the expression of genes associated with myelination, including myelin basic protein (MBP) and myelin protein zero (MPZ). Taken together, our results suggest that TSA plays an important role in regulating the growth and biological function of SCs. These data may contribute to our understanding of TSA-based treatment of neurodegenerative diseases.

Comparative study on transcatheter arterial chemoembolization, portal vein embolization and high intensity focused ultrasound sequential therapy for patients.

OBJECTIVE: To investigate the safety and efficacy of transcatheter arterial chemoembolization (TACE), combined with portal vein embolization (PVE), and high intensity focused ultrasound (HIFU) sequential therapy in treating patients with hepatocellular carcinoma (HCC). METHODS: Patients with inoperative HCC were treated by two methods: in the study group with TACE first, then PVE a week later, and then TACE+PVE every two months as a cycle, after 2~3 cycles finally HIFU was given; in the control group only TACE+PVE was given. Response (CR+PR), and disease control rate (CR+PR+SD), side effects, overall survival and time to progress were calculated. RESULTS: Main side effects of both groups were nausea and vomiting. No treatment related death occurred. In the study group, 32 patients received TACE for overall 67 times, PVE 64 times, and HIFU 99 times; on average 2.1, 2 and 3.1 times for each patient, respectively. In the control group, 36 patients were given TACE 78 times and PVE 74 times, averaging 2.2 and 2.1 times per patient. Effective rate: 25.0% in study group and 8.3% in control group (p>0.05). Disease control rates were 71.9% and 44.4%, respectively (p<0.05). In patients with portal vein tumor thrombus, the rate reduced over 1/2 after treatment was 69.2%(9/13) in the study and 21.4%(3/14) in the control group (p<0.05). Rate of AFP reversion or decrease over 1/2 was 66.7%(16/24) in study and 37%(10/27) (p<0.05) in control group. Median survival time: 16 months in study and 10 months in control group. PFS was 7months in study and 3 months in control group. Log-rank test suggested that statistically significant difference exists between two groups (p=0.024). 1-, 2- and 3-year survival rates were 56.3%, 18.8% and 9.3% in study, while 30.6%, 5.6% and 0 in control group, respectively, with statistically significant difference between two groups (by Log-rank, p = 0.014). CONCLUSIONS: The treatment of TACE+PVE+HIFU sequential therapy for HCC increases response rate, prolong survival, and could thus be a safe and effective treatment for advanced cases.

PDGF-AA and bFGF mediate B104CM-induced proliferation of oligodendrocyte precursor cells.

The conditioned medium from B104 neuroblastoma cells (B104CM) induces proliferation of οligodendrocyte precursor cells (OPCs) in vitro, which indicates that certain factors contained within B104CM give instructional signals that direct the proliferation of OPCs. However, the OPC-proliferative factors present in B104CM have yet to be identified. Platelet-derived growth factor AA (PDGF-AA), basic fibroblast growth factor (bFGF) and insulin-like growth factor-1 (IGF-1) have been reported to act as potent mitogens for OPC proliferation. This raises the possibility that B104CM induces proliferation of OPCs through secretion of PDGF­AA, bFGF and/or IGF-1. In the present study, we detected the expression and levels of PDGF-AA, bFGF and IGF-1 in B104 cells and B104CM, and observed the expression of their receptors in OPCs. The results indicated that these growth factors were expressed in B104 cells and B104CM. All 3 receptors, PDGFR, FGFR2 and IGF-1R, were also detected in OPCs. Furthermore, B104CM-stimulated OPC proliferation could be markedly decreased by both AG1295 (an inhibitor of PDGFR) and PD173074 (an inhibitor of FGFR). However, the inhibition of IGF-1R with AG1204 did not affect the proliferation of OPCs. Our study suggests that the PDGF-AA and bFGF in B104CM are 2 key factors that stimulate OPC proliferation.

Protective effects of the delta opioid peptide [D-Ala2, D-Leu5]enkephalin in an ex vivo model of ischemia/reperfusion in brain slices.

INTRODUCTION: The delta opioid peptide [D-Ala2, D-Leu5]enkephalin (DADLE) plays a key role in neuronal protection against both hypoxic and ischemic conditions. However, the cellular mechanisms of action of DADLE under these conditions remain unclear. METHODS: Ischemia was simulated with perfusing the brain slices with glucose-free artificial cerebrospinal fluid. Apoptosis was examined using an in situ cell death detection kit and expressed as the percentage of positively labeled neurons relative to total number of neurons. PCR was performed by adding cDNA, 5 pm dNTP, 1 µL Taqase, and primers. PCR products were separated with electrophoresis, stained with ethidium bromide, and visualized under ultraviolet light. AIMS: To investigate the potential effects of DADLE in an ex vivo model of cerebral ischemia/reperfusion. RESULTS: DADLE attenuated lactic dehydrogenase release and neuronal apoptosis in a concentration-dependent manner. The protective effects of DADLE were attenuated by representative selective delta2, but not delta1 opioid antagonists. Treatment with PD98059, a selective inhibitor of ERK kinase (MEK), also blocked the protective effect of DADLE as well as ERK phosphorylation induced by DADLE. CONCLUSIONS: Endogenous opioid peptides could promote cell survival via delta2 opioid receptors, possibly through the downstream MEK-ERK pathway.

Genome-Wide Gene Expression Profiling of Nucleus Accumbens Neurons Projecting to Ventral Pallidum Using both Microarray and Transcriptome Sequencing.

The cellular heterogeneity of brain poses a particularly thorny issue in genome-wide gene expression studies. Because laser capture microdissection (LCM) enables the precise extraction of a small area of tissue, we combined LCM with neuronal track tracing to collect nucleus accumbens shell neurons that project to ventral pallidum, which are of particular interest in the study of reward and addiction. Four independent biological samples of accumbens projection neurons were obtained. Approximately 500 pg of total RNA from each sample was then amplified linearly and subjected to Affymetrix microarray and Applied Biosystems sequencing by oligonucleotide ligation and detection (SOLiD) transcriptome sequencing (RNA-seq). A total of 375 million 50-bp reads were obtained from RNA-seq. Approximately 57% of these reads were mapped to the rat reference genome (Baylor 3.4/rn4). Approximately 11,000 unique RefSeq genes and 100,000 unique exons were identified from each sample. Of the unmapped reads, the quality scores were 4.74 ± 0.42 lower than the mapped reads. When RNA-seq and microarray data from the same samples were compared, Pearson correlations were between 0.764 and 0.798. The variances in data obtained for the four samples by microarray and RNA-seq were similar for medium to high abundance genes, but less among low abundance genes detected by microarray. Analysis of 34 genes by real-time polymerase chain reaction showed higher correlation with RNA-seq (0.66) than with microarray (0.46). Further analysis showed 20-30 million 50-bp reads are sufficient to provide estimates of gene expression levels comparable to those produced by microarray. In summary, this study showed that picogram quantities of total RNA obtained by LCM of ∼700 individual neurons is sufficient to take advantage of the benefits provided by the transcriptome sequencing technology, such as low background noise, high dynamic range, and high precision.

Propofol attenuates oxidative stress-induced PC12 cell injury via p38 MAP kinase dependent pathway.

AIM: To investigate the neuroprotective effect of propofol and its intracellular mechanism on neurons in vitro. METHODS: Cell viability was determined with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide reduction. Apoptotic cell death was determined by Hoechst 33258 staining and a fluorescence-activated cell sorter. The caspase-3 activity was measured by fluorometric assay. Mitogen-activated protein (MAP) kinase phosphorylation was detected with Western blotting. RESULTS: The pretreatment of rat pheochromocytoma cell line PC12 with propofol (1-10 micromol/L) resulted in a significant recovery from hydrogen peroxide (H2O2)-induced cell death and the inhibition of H2O2 induced caspase-3 activation and PC12 cell apoptosis. Propofol inhibited the H2O2-induced p38 MAP kinase, but not c-Jun N-terminal kinase or extracellular signal-regulated kinase 1 and 2 activations. CONCLUSION: Propofol might attenuate H2O2-induced PC12 cell death through the inhibition of signaling pathways mediated by the p38 MAP kinase.

Phosphorylated heat shock protein 27 is involved in enhanced heart tolerance to ischemia in short-term type 1 diabetic rats.

AIM: To examine the tolerance of type 1 diabetic hearts to ischemia and reperfusion injury. Myocardial contents of 27-kDa and 70-kDa heat shock proteins (hsp) as well as phosphorylated hsp27 were also determined. METHODS: Hearts from hyperglycemic rats 3 weeks after streptozocin injection and age-matched normal rats were subjected to ischemia and reperfusion in vitro. Cardiac function and electrocardiogram were recorded throughout experiments. Myocardial heat shock proteins were detected with Western blot. RESULTS: Despite depressed systolic function at the baseline, diabetic hearts exhibited considerable enhancement in post-ischemic heart function, manifested by an increase in the maximal rate of left ventricular pressure rise and fall (post-ischemic dp/dtmax and dp/dtmin were 560+/-117 and -313+/-68 mmHg/s in control, n=7, 1249+/-57 and -1204+/-36 mmHg/s in diabetes, n=10, P<0.01). Reperfusion ventricular fibrillation in the diabetic group were attenuated compared with controls (1.5+/-0.3 vs 7.2+/-2.1 min in control, P<0.01). The increased heart resistance to ischemia in diabetes was associated with hyperglycemia and accompanied by enhanced expression of myocardial phosphorylated hsp27 with normal aortic vessel relaxation. Cardioprotection was abrogated by metabolic correction with insulin and accompanied by phospho-hsp27 reduction. CONCLUSION: Heart resistance to ischemia is increased in type 1 diabetes, and hyperglycemia may present a mild yet stressful stimulus leading to upregulation of endogenous stress protein, which may play a potential role in cardioprotection and compensate for detrimental effects of hyperglycemia in diabetes.