Repositioning of anti-cancer drug candidate, AZD7762, to an anti-allergic drug suppressing IgE-mediated mast cells and allergic responses via the inhibition of Lyn and Fyn

Mast cells are critical effector cells in IgE-mediated allergic responses. The aim of this study was to investigate the anti-allergic effects of 3-[(aminocarbonyl)amino]-5-(3-fluorophenyl)-N-(3S)-3-piperidinyl-2-thiophenecarboxamide (AZD7762) in vitro and in vivo. AZD7762 inhibited the antigen-stimulated degranulation from RBL-2H3 (IC₅₀, ∼27.9 nM) and BMMCs (IC₅₀, ∼99.3 nM) in a dose-dependent manner. AZD7762 also inhibited the production of TNF-α and IL-4. As the mechanism of its action, AZD7762 inhibited the activation of Syk and its downstream signaling proteins, such as Linker of activated T cells (LAT), phospholipase (PL) Cγ1, Akt, and mitogen-activated protein (MAP) kinases (Erk1/2, p38, and JNK) in mast cells. In in vitro protein kinase assay, AZD7762 inhibited the activity of Lyn and Fyn kinases, which are important for the activation of Syk in mast cells. Furthermore, AZD7762 also suppressed the degranulation of LAD2 human mast cells (IC₅₀, ∼49.9 nM) and activation of Syk in a dose-dependent manner. As observed in experiments with mast cells in vitro, AZD7762 inhibited antigen-mediated passive cutaneous anaphylaxis in mice (ED₅₀, ∼35.8 mg/kg). Altogether, these results suggest that AZD7762 could be used as a new therapeutic agent for mast cell-mediated allergic diseases.

It's not just about recruitment: An exploratory look at tobacco education sessions to increase participation into smoking cessation programs among American Indians

American Indians (AI) have the highest smoking rates and lowest quit rates of any racial/ethnic group in the U.S. Researchers and community members from the American Indian Health Research and Education Alliance (AIHREA) created and evaluated a culturally-tailored smoking cessation program, All Nations Breath of Life (ANBL) as a recruitment tool for smoking cessation programs among AI. To increase enrollment in ANBL, AI smokers were approached at cultural events and asked to attend a 30-minute educational session (in-person, n= 179; tele-video, n=97). Tele-video (30%) and in-person (9%) session participants were recruited into ANBL. Pre- and post-tests showed participants in both sessions demonstrated increased motivation and confidence to quit smoking but significant differences were present in both sessions (p < 0.0001). Results indicate that theoretically guided and culturally tailored education sessions are viable approaches to educate and recruit underserved populations into programs that promote smoking cessation.

Furaltadone suppresses IgE-mediated allergic response through the inhibition of Lyn/Syk pathway in mast cells

Mast cells are critical cells that prompt various allergic response-inducing factors, contributing to allergic diseases. While used as an antibiotic for livestock, there is no study on the effect of furaltadone on allergic response. This study investigated the effect of furaltadone on mast cells and passive cutaneous anaphylaxis (PCA). Furaltadone inhibited the degranulation of mast cells stimulated by antigen (IC₅₀, ~ 3.9 μM), and also suppressed the production of tumor necrosis factor (TNF)-α and interleukin (IL)-4 in a concentration dependent manner. In addition, furaltadone inhibited allergic responses in an acute allergy animal model, PCA. Further investigation on the mechanism for these inhibitory effects of furaltadone found that the activities of Lyn/Syk and Syk-dependent downstream proteins such as mitogen-activated protein (MAP) kinases were inhibited by furaltadone in mast cells. Taken together, this study demonstrates that furaltadone inhibits the activation of mast cells by antigen via the suppression of the Lyn/Syk pathway and ameliorates allergic responses in vivo.

Neoagarohexaose-mediated activation of dendritic cells via Toll-like receptor 4 leads to stimulation of natural killer cells and enhancement of antitumor immunity

β-Agarase cleaves the β-1,4 linkages of agar to produce neoagarooligosaccharides (NAO), which are associated with various physiological functions. However, the immunological functions of NAO are still unclear. In this study, we demonstrated that β-agarase DagA-produced neoagarohexaose (DP6), an NAO product, promoted the maturation of dendritic cells (DCs) by Toll-like receptor 4 (TLR4). DP6 directly and indirectly enhanced the activation of natural killer (NK) cells in a TLR4-dependent manner in vitro and in vivo. Finally, the antitumor activity of DP6 against B16F1 melanoma cells was inhibited in NK cell-depletion systems by using NK-cell depleting antibodies in vivo. Collectively, the results indicated that DP6 augments antitumor immunity against B16F1 melanoma cells via the activation of DC-mediated NK cells in a TLR4-dependent manner. Thus, DP6 is a potential candidate adjuvant that acts as an immune cell modulator for the treatment of melanoma. [BMB Reports 2017; 50(5): 263-268].

A novel mouse model of atopic dermatitis that is T helper 2 (Th2)-polarized by an epicutaneous allergen

The pathogenesis of atopic dermatitis (AD) involves T helper 2 (Th2) cells, and effective therapies remain elusive due to the paucity of animal models. We aimed to develop a mouse model of an immune system aberration caused by allergen. Experiments were conducted in two phases. In experiment 1, BALB/c mice were sensitized with one of four chemical allergens - toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), trimellitic anhydride (TMA), or 2,4-dinitrochlorobenzene (DNCB) - for 3 weeks. Based on results of experiment 1, immunological features were compared between TMA-sensitized BALB/c mice and NC/Nga mice, after exposure to mite extracts, harmful chemicals and detergents in experiment 2. Sensitization by allergen caused a large number of pathological changes in the skin, and an increase in mast cell number. TMA-sensitized BALB/c mice models showed higher sensitivity to an environmental allergen than NC/Nga mice did. Overall, the initial sensitization with TMA leads to disturbances in Th2-mediated immunity.

Polysaccharide isolated from Aloe vera gel suppresses ovalbumin-induced food allergy through inhibition of Th2 immunity in mice

An allergic reaction occurs when the immune system overreacts to harmless substance called allergen that gains access to the body. Food allergy is a hypersensitive immune reaction to food proteins and the number of patients with food allergy has recently increased. Aloe Vera is used for wellness and medicinal purposes. In particular, Aloe vera has been reported to enhance immunity. However, the effect of Aloe vera on food allergy is not yet known. In this study, we investigated the effects of processed Aloe vera gel (PAG) containing low molecular weight Aloe polysaccharide (AP) on ovalbumin (OVA)-induced food allergy in mice. Allergic symptoms, rectal temperature, and diarrhea were measured in OVA-induced food allergy mice. Other allergic parameters were also analyzed by RT-PCR, ELISA, flow cytometry, and other biochemical methods. As the results, PAG suppressed the decrease of body temperature, diarrhea, and allergic symptoms in OVA-induced food allergy mice. PAG also reduced serum concentrations of type 2 helper T cell (Th2) cytokines (Interleukin-(IL)-4, IL-5, and IL-13) as well as histamine, mast cell protease-1 (MCP-1), and immunoglobulin (Ig)E. PAG blocked the degranulation of mast cells and infiltration of eosinophils in intestine. Furthermore, PAG suppressed the population of Th2 cells in spleen and mesenteric lymph nodes. PAG also increased the production of IL-10 and population of type 1 regulatory T (Tr1) cells in mice with food allergy. Taken together, our findings suggest that PAG suppressed Th2 immune responses through, at least partially, stimulating the secretion of IL-10 in food allergy mice.

Epigenetic reader BRD4 inhibition as a therapeutic strategy to suppress E2F2-cell cycle regulation circuit in liver cancer

Deregulation of the epigenome component affects multiple pathways in the cancer phenotype since the epigenome acts at the pinnacle of the hierarchy of gene expression. Pioneering work over the past decades has highlighted that targeting enzymes or proteins involved in the epigenetic regulation is a valuable approach to cancer therapy. Very recent results demonstrated that inhibiting the epigenetic reader BRD4 has notable efficacy in diverse cancer types. We investigated the potential of BRD4 as a therapeutic target in liver malignancy. BRD4 was overexpressed in three different large cohort of hepatocellular carcinoma (HCC) patients as well as in liver cancer cell lines. BRD4 inhibition by JQ1 induced anti-tumorigenic effects including cell cycle arrest, cellular senescence, reduced wound healing capacity and soft agar colony formation in liver cancer cell lines. Notably, BRD4 inhibition caused MYC-independent large-scale gene expression changes in liver cancer cells. Serial gene expression analyses with SK-Hep1 liver cancer cells treated with JQ1 to delineate the key player of BRD4 inhibition identified E2F2 as the first line of downstream direct target of BRD4. Further experiments including chromatin immunoprecipitation (ChIP) assay and loss of function study confirmed E2F2 as key player of BRD4 inhibition. Overexpressed E2F2 is a crucial center of cell cycle regulation and high expression of E2F2 is significantly associated with poor prognosis of HCC patients. Our findings reveal BRD4-E2F2-cell cycle regulation as a novel molecular circuit in liver cancer and provide a therapeutic strategy and innovative insights for liver cancer therapies.

DJ-1 controls bone homeostasis through the regulation of osteoclast differentiation

Receptor activator of NF-kB ligand (RANKL) generates intracellular reactive oxygen species (ROS), which increase RANKL-mediated signaling in osteoclast (OC) precursor bone marrow macrophages (BMMs). Here we show that a ROS scavenging protein DJ-1 negatively regulates RANKL-driven OC differentiation, also called osteoclastogenesis. DJ-1 ablation in mice leads to a decreased bone volume and an increase in OC numbers. In vitro, the activation of RANK-dependent signals is enhanced in DJ-1-deficient BMMs as compared to wild-type BMMs. DJ-1 suppresses the activation of both RANK-TRAF6 and RANK-FcRγ/Syk signaling pathways because of activation of Src homology region 2 domain-containing phosphatase-1, which is inhibited by ROS. Ablation of DJ-1 in mouse models of arthritis and RANKL-induced bone disease leads to an increase in the number of OCs, and exacerbation of bone damage. Overall, our results suggest that DJ-1 plays a role in bone homeostasis in normal physiology and in bone-associated pathology by negatively regulating osteoclastogenesis.

Osteoclasts are involved in arthritis, and their differentiation depends on RANKL signaling. The author show that the ROS-scavenging protein DJ-1 negatively regulates RANKL signaling and that its ablation increases osteoclast numbers and exacerbates bone damage in mouse models of arthritis.

Fibrinogen cleavage products and Toll-like receptor 4 promote the generation of programmed cell death 1 ligand 2-positive dendritic cells in allergic asthma

BACKGROUND

Inhaled protease allergens preferentially trigger T_H2-mediated inflammation in allergic asthma. The role of dendritic cells (DCs) on induction of T_H2 cell responses in allergic asthma has been well documented; however, the mechanism by which protease allergens induce T_H2-favorable DCs in the airway remains unclear.

OBJECTIVE

We sought to determine a subset of DCs responsible for T_H2 cell responses in allergic asthma and the mechanism by which protease allergens induce the DC subset in the airway.

METHODS

Mice were challenged intranasally with protease allergens or fibrinogen cleavage products (FCPs) to induce allergic airway inflammation. DCs isolated from mediastinal lymph nodes were analyzed for surface phenotype and T-cell stimulatory function. Anti-Thy1.2 and Mas-TRECK mice were used to deplete innate lymphoid cells and mast cells, respectively. Adoptive cell transfer, bone marrow DC culture, anti-IL-13, and Toll-like receptor (TLR) 4-deficient mice were used for further mechanistic studies.

RESULTS

Protease allergens induced a remarkable accumulation of T_H2-favorable programmed cell death 1 ligand 2 (PD-L2)⁺ DCs in mediastinal lymph nodes, which was significantly abolished in mice depleted of mast cells and, to a lesser extent, innate lymphoid cells. Mechanistically, FCPs generated by protease allergens triggered IL-13 production from wild-type mast cells but not from TLR4-deficient mast cells, which resulted in an increase in the number of PD-L2⁺ DCs. Intranasal administration of FCPs induced an increase in numbers of PD-L2⁺ DCs in the airway, which was significantly abolished in TLR4- and mast cell-deficient mice. Injection of IL-13 restored the PD-L2⁺ DC population in mice lacking mast cells.

CONCLUSION

Our findings unveil the "protease-FCP-TLR4-mast cell-IL-13" axis as a molecular mechanism for generation of T_H2-favorable PD-L2⁺ DCs in allergic asthma and suggest that targeting the PD-L2⁺ DC pathway might be effective in suppressing allergic T-cell responses in the airway.

A novel IL-10-producing innate lymphoid cells (ILC10) in a contact hypersensitivity mouse model

The immunoregulatory cytokine Interleukin 10 (IL-10) protein is produced by various cells during the course of inflammatory disorders. Mainly, it downregulates pro-inflammatory cytokines, antigen presentation, and helper T cell activation. In this study, we show that the ratio of IL-10-producing cells was significantly increased in lineage negative (i.e., not T, B, or leukocyte cell lineages) cells than in lineage positive cells in lymphoid and peripheral tissues. We further observed that IL-10-producing innate lymphoid cells (ILCs), here called firstly ILC10, were increased in number in oxazolone-induced contact hypersensitivity (CHS) mice. In detail, IL-10-producing lineage negative cells were elevated in the axillary, inguinal lymph node, and ear tissues of CHS mice. Notably, the cells expressed classical ILC marker proteins such as CD45, CD127, and Sca-1. Altogether, our findings suggest for the first time that ILC10s are present in various physiological settings and could be involved in numerous immune responses as regulatory cells. [BMB Reports 2016; 49(5): 293-296]

Anticancer Effects of a New SIRT Inhibitor, MHY2256, against Human Breast Cancer MCF-7 Cells via Regulation of MDM2-p53 Binding

The sirtuins (SIRTs), a family of NAD⁺-dependent class III histone deacetylase, are involved in various biological processes including cell survival, division, senescence, and metabolism via activation of the stress-response pathway. Recently, inhibition of SIRTs has been considered a promising anticancer strategy, but their precise mechanisms of action are not well understood. In particular, the relevance of p53 to SIRT-induced effects has not been fully elucidated. We investigated the anticancer effects of a novel SIRT inhibitor, MHY2256, and its efficacy was compared to that of salermide in MCF-7 (wild-type p53) and SKOV-3 (null-type p53) cells. Cell viability, SIRT1 enzyme activity, cell cycle regulation, apoptosis, and autophagic cell death were measured. We compared sensitivity to cytotoxicity in MCF-7 and SKOV-3 cells. MHY2256 significantly decreased the viability of MCF-7 (IC₅₀, 4.8 μM) and SKOV-3 (IC₅₀, 5.6 μM) cells after a 48 h treatment period. MHY2256 showed potent inhibition (IC₅₀, 0.27 mM) against SIRT1 enzyme activity compared with nicotinamide (IC_50, >1 mM). Moreover, expression of SIRT (1, 2, or 3) protein levels was significantly reduced by MHY2256 treatment in both MCF-7 and SKOV-3 cells. Flow cytometry analysis revealed that MHY2256 significantly induced cell cycle arrest in the G1 phase, leading to an effective increase in apoptotic cell death in MCF-7 and SKOV-3 cells. A significant increase in acetylated p53, a target protein of SIRT, was observed in MCF-7 cells after MHY2256 treatment. MHY2256 up-regulated LC3-II and induced autophagic cell death in MCF-7 cells. Furthermore, MHY2256 markedly inhibited tumor growth in a tumor xenograft model of MCF-7 cells. These results suggest that a new SIRT inhibitor, MHY2256, has anticancer activity through p53 acetylation in MCF-7 human breast cancer cells.

Discovery of urinary metabolomic biomarkers for early detection of acute kidney injury

The discovery of new biomarkers for early detection of drug-induced acute kidney injury (AKI) is clinically important. In this study, sensitive metabolomic biomarkers identified in the urine of rats were used to detect cisplatin-induced AKI. Cisplatin (10 mg kg(-1), i.p.) was administered to Sprague-Dawley rats, which were subsequently euthanized after 1, 3 or 5 days. In cisplatin-treated rats, mild histopathological alterations were noted at day 1, and these changes were severe at days 3 and 5. Blood urea nitrogen (BUN) and serum creatinine (SCr) levels were significantly increased at days 3 and 5. The levels of new urinary protein-based biomarkers, including kidney injury molecule-1 (KIM-1), glutathione S-transferase-α (GST-α), tissue inhibitor of metalloproteinase-1 (TIMP-1), vascular endothelial growth factor (VEGF), calbindin, clusterin, neutrophil, neutrophil gelatinase-associated lipocalin (NGAL), and osteopontin, were significantly elevated at days 3 and 5. Among urinary metabolites, trigonelline and 3-indoxylsulfate (3-IS) levels were significantly decreased in urine collected from cisplatin-treated rats prior to histological kidney damage. However, carbon tetrachloride (CCl4), a hepatotoxicant, did not affect these urinary biomarkers. Trigonelline is closely associated with GSH depletion and results in insufficient antioxidant capacity against cisplatin-induced AKI. The predominant cisplatin-induced AKI marker appeared to be reduced in urinary 3-IS levels. Because 3-IS is predominantly excreted via active secretion in proximal tubules, a decrease is indicative of tubular damage. Further, urinary excretion of 3-IS levels was markedly reduced in patients with AKI compared to normal subjects. The area under the curve receiver operating characteristics (AUC-ROC) for 3-IS was higher than for SCr, BUN, lactate dehydrogenase (LDH), total protein, and glucose. Therefore, low urinary or high serum 3-IS levels may be more useful for early detection of AKI than conventional biomarkers.

Surveillance of the Middle East respiratory syndrome (MERS) coronavirus (CoV) infection in healthcare workers after contact with confirmed MERS patients: incidence and risk factors of MERS-CoV seropositivity

Given the mode of transmission of Middle East respiratory syndrome (MERS), healthcare workers (HCWs) in contact with MERS patients are expected to be at risk of MERS infections. We evaluated the prevalence of MERS coronavirus (CoV) immunoglobulin (Ig) G in HCWs exposed to MERS patients and calculated the incidence of MERS-affected cases in HCWs. We enrolled HCWs from hospitals where confirmed MERS patients had visited. Serum was collected 4 to 6 weeks after the last contact with a confirmed MERS patient. We performed an enzyme-linked immunosorbent assay (ELISA) to screen for the presence of MERS-CoV IgG and an indirect immunofluorescence test (IIFT) to confirm MERS-CoV IgG. We used a questionnaire to collect information regarding the exposure. We calculated the incidence of MERS-affected cases by dividing the sum of PCR-confirmed and serology-confirmed cases by the number of exposed HCWs in participating hospitals. In total, 1169 HCWs in 31 hospitals had contact with 114 MERS patients, and among the HCWs, 15 were PCR-confirmed MERS cases in study hospitals. Serologic analysis was performed for 737 participants. ELISA was positive in five participants and borderline for seven. IIFT was positive for two (0.3%) of these 12 participants. Among the participants who did not use appropriate personal protective equipment (PPE), seropositivity was 0.7% (2/294) compared to 0% (0/443) in cases with appropriate PPE use. The incidence of MERS infection in HCWs was 1.5% (17/1169). The seroprevalence of MERS-CoV IgG among HCWs was higher among participants who did not use appropriate PPE.

Effects of pH and Salts on Physical and Mechanical Properties of Pea Starch Films

To identify the significant contribution of intermolecular hydrogen bonds of starch molecules to the film structure formation, pH of film-forming solutions was adjusted and also various salts (NaCl, CaCl2 , CaSO4 , and K2 SO4 ) were mixed into the glycerol-plasticized pea starch film. The film made from pH 7 possessed the highest tensile strength-at-break (2 times) and elastic modulus (4 to 15 times) and the lowest elongation-at-break compared with those of the films made from acid and alkali environments. The pH 7 film also has the highest film density and the lowest total soluble matter. At the level of 0.01 to 0.1 M of CaSO4 and 0.1 M of K2 SO4 in a kilogram of starch, the water solubility of the film increased, while chloride salts slightly lowered the solubility. NaCl and CaSO4 reduced water vapor permeability (WVP), while CaCl2 slightly increased WVP at 0.01 and 0.06 M concentrations, and K2 SO4 significantly increased WVP at 0.03 and 0.15 M. Presence of salts increased tensile strength (5 to 14 times than the control films) and elastic modulus (35 to 180 times) of starch film at 0.01 to 0.03 M of CaSO4 and K2 SO4 . Elongation-at-break increased significantly as salt concentration increases to an optimal level. However, when the concentration exceeded above the optimal level, the E of starch films decreased and showed no significant difference from the control film. Overall, the addition of salts modified physical and mechanical properties of pea starch films more than pH adjustment without any salt addition.

Properties of Dye-Sensitized Solar Cells Using Carbon Nanowall Counter Electrodes

This research investigates plasma-treated and metal-coated carbon nanowalls (CNWs) for use as counter electrodes of dye-sensitized solar cells (DSSCs). The CNWs were synthesized on a fluorine-tin-oxide (FTO) glass substrate using the microwave plasma-enhanced chemical vapor deposition (PECVD) system with methane (CH4) gas. The post-plasma treatment was performed on the CNWs with hydrogen (H2) plasma using PECVD, and the CNWs were sputter-coated with metal films using the RF magnetron sputtering system with a four-inch tungsten (W) target. Then the post-plasma-treated and metal-coated CNWs were used as counter electrodes for the fabrication of the DSSCs. Field-emission scanning electron microscopy (FE-SEM) was performed to obtain cross-sectional and planar images of the grown CNWs. The energy conversion efficiencies of the DSSCs manufactured using the post-plasma-treated and metal-layer-coated CNWs as the counter electrodes were measured.

Reaction Gas Ratio Effect on the Growth of a Diamond Film Using Microwave Plasma-Enhanced Chemical Vapor Deposition

In this study, diamond films were prepared using the microwave plasma-enhanced chemical vapor deposition (PECVD) system, which included a DC bias system to enhance the nucleation of the films. The films were synthesized on Si wafers with different ratios of methane (CH4) and hydrogen (H2) gases. We have studied the effects of the CH4-to-H2 ratio on the structural and optical properties of diamond films. The thickness and surface profile of the films were characterized via field emission scanning electron microscopy (FE-SEM). Raman was used to investigate the structural properties of the diamond films. The refractive indexes as functions of the CH4-to-H2 ratio were measured using an ellipsometer. The FE-SEM analysis showed that the 3 and 5 sccm CH4 created diamond films. The Raman analysis indicated that a nanocrystalline diamond film was formed at 3 sccm; a general diamond film, at 5 sccm; and films similar to the a-C:H film, at 7 sccm. The ellipsometer measurement showed that the refractive index of the synthesized diamond film was around 2.42 at 3 sccm. This value decreased as the CH4 volume increased.

Efficacy and safety of ursodeoxycholic acid composite on fatigued patients with elevated liver function and/or fatty liver: a multi-centre, randomised, double-blinded, placebo-controlled trial

AIM

The aim of this study was to assess the effects of ursodeoxycholic acid composite (URSA-S) on fatigue in patients with elevated liver function tests and/or fatty liver disease.

METHODS

In this multi-centre randomised double-blinded placebo-controlled trial, 168 adults who were diagnosed with fatigue based on our criteria and had elevated liver function tests (but not > 5 times the normal level) and/or fatty liver on ultrasonography, were randomised to either the placebo or URSA-S administration group. The rate of improvement of checklist individual strength (CIS) using a cut-off of 76 points at the end of the study (8 weeks), the change in fatigue scale [CIS score and visual analogue scale (VAS)] were evaluated. The adverse effects of URSA-S were also recorded.

RESULTS

The rate of CIS improvement at the end-point was 79.76% and 45.68% in the therapy and placebo groups, respectively (p < 0.05). The fatigue recovery rate of the CIS score and VAS were higher in the therapy (-25.44 ± 18.57, -27.84 ± 2.70) than in the placebo group (-16.59 ± 17.29, -19.46 ± 2.81) (p < 0.05). The difference in fatigue recovery rate between the therapy and placebo groups was significant after 8 weeks. When analysed separately in patients with abnormal liver function tests and fatty liver disease, the fatigue recovery rate of the CIS score and VAS at 8 weeks was higher in the therapy than in the placebo group (p < 0.05). The frequency of adverse events in the therapy group was not significantly higher than that in the placebo group.

CONCLUSION

URSA-S is effective for alleviating fatigue in patients with liver dysfunction and/or fatty liver. The adverse effects of URSA-S are not significant. This study is registered at https://clinicaltrials.gov/ct2/show/NCT02415777.

Diminished Lipid Raft SNAP23 Increases Blood Pressure by Inhibiting the Membrane Fluidity of Vascular Smooth-Muscle Cells

Synaptosomal-associated protein 23 (SNAP23) is involved in microvesicle trafficking and exocytosis in various cell types, but its functional role in blood pressure (BP) regulation has not yet been defined. Here, we found that lipid raft SNAP23 expression was much lower in vascular smooth-muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) than in those from normotensive Wistar-Kyoto (WKY) rats. This led us to investigate the hypothesis that this lower expression may be linked to the spontaneous hypertension found in SHR. The expression level of lipid raft SNAP23 and the fluidity in the plasma membrane of VSMCs were lower in SHR than in WKY rats. Cholesterol content in the VSMC membrane was higher, but the secreted cholesterols found in VSMC-conditioned medium and in the blood serum were lower in SHR than in WKY rats. SNAP23 knockdown in WKY rat VSMCs reduced the membrane fluidity and increased the membrane cholesterol level. Systemic overexpression of SNAP23 in SHR resulted in an increase of cholesterol content in their serum, a decrease in cholesterol in their aorta and the reduction of their BP. Our findings suggest that the low expression of the lipid raft SNAP23 in VSMCs might be a potential cause for the characteristic hypertension of SHR.

Biological Behavior of Osteoblast Cell and Apatite Forming Ability of the Surface Modified Ti Alloys

Titanium as one kind of biomaterials comes in direct contact with the body, making evaluation of biocompatibility an important aspect to biomaterials development. Surface chemistry of titanium plays an important role in osseointegration. Different surface modification alters the surface chemistry and result in different biological response. In this study, three kinds of mixed acid solutions were used to treat Ti specimens to induce Ca-P formation. Following a strong mixed acid activation process, Ca-P coating successfully formed on the Ti surfaces in simulated body fluid. Strong mixed acid increased the roughness of the metal surface, because the porous and rough surface allows better adhesion between Ca-P coatings and substrates. After modification of titanium surface by mixed acidic solution and subsequently H2O2/HCL treatment evaluation of biocompatibility was conducted from hydroxyapatite formation by biomimetic process and cell viability on modified titanium surface. Nano-scale modification of titanium surfaces can alter cellular and tissue responses, which may benefit osseointegration and dental implant therapy. Results from this study indicated that surface treatment methods affect the surface morphology, type of TiO2 layer formed and subsequent apatite deposition and biological responses. The thermo scientific alamarblue cell viability assay reagent is used to quantitatively measure the viability of mammalian cell lines, bacteria and fungi by incorporating a rapid, sensitive and reliable fluorometric/colorimetric growth indicator, without any toxic and side effect to cell line. In addition, mixed acid treatment uses a lower temperature and shorter time period than widely used alkali treatment.

Mesenteric IL-10-producing CD5+ regulatory B cells suppress cow's milk casein-induced allergic responses in mice

Food allergy is a hypersensitive immune reaction to food proteins. We have previously demonstrated the presence of IL-10-producing CD5(+) B cells and suggested their potential role in regulating cow's milk casein allergy in humans and IgE-mediated anaphylaxis in mice. In this study, we determined whether IL-10-producing CD5(+) regulatory B cells control casein-induced food allergic responses in mice and, if so, the underlying mechanisms. The induction of oral tolerance (OT) by casein suppressed casein-induced allergic responses including the decrease of body temperature, symptom score, diarrhea, recruitment of mast cells and eosinophils into jejunum, and other biological parameters in mice. Notably, the population of IL-10-producing CD5(+) B cells was increased in mesenteric lymph node (MLN), but not in spleen or peritoneal cavity (PeC) in OT mice. The adoptive transfer of CD5(+) B cells from MLN, but not those from spleen and PeC, suppressed the casein-induced allergic responses in an allergen-specific and IL-10-dependent manner. The inhibitory effect of IL-10-producing CD5(+) B cells on casein-induced allergic response was dependent on Foxp3(+) regulatory T cells. Taken together, mesenteric IL-10-producing regulatory B cells control food allergy via Foxp3(+) regulatory T cells and could potentially act as a therapeutic regulator for food allergy.

A novel role for flotillin-1 in H-Ras-regulated breast cancer aggressiveness

Elevated expression and aberrant activation of Ras have been implicated in breast cancer aggressiveness. H-Ras, but not N-Ras, induces breast cell invasion. A crucial link between lipid rafts and H-Ras function has been suggested. This study sought to identify the lipid raft protein(s) responsible for H-Ras-induced tumorigenicity and invasiveness of breast cancer. We conducted a comparative proteomic analysis of lipid raft proteins from invasive MCF10A human breast epithelial cells engineered to express active H-Ras and non-invasive cells expressing active N-Ras. Here, we identified a lipid raft protein flotillin-1 as an important regulator of H-Ras activation and breast cell invasion. Flotillin-1 was required for epidermal growth factor-induced activation of H-Ras, but not that of N-Ras, in MDA-MB-231 triple-negative breast cancer (TNBC) cells. Flotillin-1 knockdown inhibited the invasiveness of MDA-MB-231 and Hs578T TNBC cells in vitro and in vivo. In xenograft mouse tumor models of these TNBC cell lines, we showed that flotillin-1 played a critical role in tumor growth. Using human breast cancer samples, we provided clinical evidence for the metastatic potential of flotillin-1. Membrane staining of flotillin-1 was positively correlated with metastatic spread (p = 0.013) and inversely correlated with patient disease-free survival rates (p = 0.005). Expression of flotillin-1 was associated with H-Ras in breast cancer, especially in TNBC (p < 0.001). Our findings provide insight into the molecular basis of Ras isoform-specific interplay with flotillin-1, leading to tumorigenicity and aggressiveness of breast cancer.

Autocrine stimulation of IL-10 is critical to the enrichment of IL-10-producing CD40(hi)CD5(+) regulatory B cells in vitro and in vivo

IL-10-producing B (Breg) cells regulate various immune responses. However, their phenotype remains unclear. CD40 expression was significantly increased in B cells by LPS, and the Breg cells were also enriched in CD40^hiCD5⁺ B cells. Furthermore, CD40 expression on Breg cells was increased by IL-10, CD40 ligand, and B cell-activating factor, suggesting that CD40^hi is a common phenotype of Breg cells. LPS-induced CD40 expression was largely suppressed by an anti-IL-10 receptor antibody and in IL-10^−/−CD5⁺CD19⁺ B cells. The autocrine effect of IL-10 on the CD40 expression was largely suppressed by an inhibitor of JAK/STAT3. In vivo, the LPS treatment increased the population of CD40^hiCD5⁺ Breg cells in mice. However, the population of CD40^hiCD5⁺ B cells was minimal in IL-10^−/− mice by LPS. Altogether, our findings show that Breg cells are largely enriched in CD40^hiCD5⁺ B cells and the autocrine effect of IL-10 is critical to the formation of CD40^hiCD5⁺ Breg cells. [BMB Reports 2015; 48(1): 54-59]

An indoxyl compound 5-bromo-4-chloro-3-indolyl 1,3-diacetate, CAC-0982, suppresses activation of Fyn kinase in mast cells and IgE-mediated allergic responses in mice

Mast cells, constituents of virtually all organs and tissues, are critical cells in IgE-mediated allergic responses. The aim of this study was to investigate the effect and mechanism of an indoxyl chromogenic compound, 5-bromo-4-chloro-3-indolyl 1,3-diacetate, CAC-0982, on IgE-mediated mast cell activation and allergic responses in mice. CAC-0982 reversibly suppressed antigen-stimulated degranulation in murine mast cells (IC50, ~3.8μM) and human mast cells (IC50, ~3.0μM). CAC-0982 also inhibited the expression and secretion of IL-4 and TNF-α in mast cells. Furthermore, CAC-0982 suppressed the mast cell-mediated allergic responses in mice in a dose-dependent manner (ED50 27.9mg/kg). As for the mechanism, CAC-0982 largely suppressed the phosphorylation of Syk and its downstream signaling molecules, including LAT, Akt, Erk1/2, p38, and JNK. Notably, the tyrosine kinase assay of antigen-stimulated mast cells showed that CAC-0982 inhibited Fyn kinase, one of the upstream tyrosine kinases for Syk activation in mast cells. Taken together, these results suggest that CAC-0982 may be used as a new treatment for regulating IgE-mediated allergic diseases through the inhibition of the Fyn/Syk pathway in mast cells.

Rhamnus davurica leaf extract inhibits Fyn activation by antigen in mast cells for anti-allergic activity

BACKGROUND

Complementary and alternative herbal medicines are recently considered as a promising approach for treating various diseases. We screened approximately 100 plant extracts for anti-allergic activity. Rhamnus davurica leaf extract showed the most potent inhibitory effect on the activation of RBL-2H3 mast cells. Although Rhamnus davurica extract has been used to treat pruritus, dysuresia, and constipation as a traditional herbal medicine in some Asian countries, an anti-allergic effect of Rhamnus davurica has not yet been demonstrated. We aimed to investigate the effect and mechanism of the leaf extract of Rhamnus davurica (LERD) on mast cells in vitro and allergic responses in vivo.

METHODS

The effects of LERD on the activation of mast cells and mast cell-mediated passive cutaneous anaphylaxis (PCA) were measured in mice and two types of mast cells, mouse bone marrow-derived mast cells (BMMCs) and RBL-2H3 cells in vitro. A mechanistic study of its inhibitory effect was performed by using degranulation assay, reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, and western blotting analysis.

RESULTS

LERD reversibly suppressed antigen-stimulated degranulation in BMMCs and RBL-2H3 cells, and also inhibited mRNA expression and secretion of TNF-α and IL-4 in a dose-dependent manner. In a PCA animal model, LERD significantly inhibited antigen-induced allergic response and degranulation of ear tissue mast cells. As for the mechanism of action, LERD inhibited the activation of Syk, which is the pivotal signaling protein for mast cell activation by antigen. Furthermore, LERD also impeded the activations of well-known downstream proteins such as LAT, Akt and three MAP kinases (Erk, p38 and JNK). In an in vitro kinase assay, LERD suppressed the activation of Fyn in antigen-stimulated mast cells.

CONCLUSION

This study demonstrated for the first time that LERD has anti-allergic effects through inhibiting the Fyn/Syk pathway in mast cells. Therefore, this study provides scientific evidence for LERD to be used as an herbal medicine or health food for patients with allergic diseases.