Sonochemical synthesis of ErVO4/MnWO4 heterostructures: Application as a novel nanostructured surface for electrochemical determination of tyrosine in biological samples

Present strategy introduces a novel method established for the synthesis of spherical shape ErVO4/MnWO4 heterostructures by a sonochemical method. This heterostructures with optima morphology can be synthesized by changing power and time ultrasound irradiation without any capping agent. BET analysis revealed that ErVO4/MnWO4 prepared in the presence of ultrasonic procedure has 75 times specific surface area as much as that of those was produced in the absence of ultrasonic rays. A variety of analyses (i.e., BET, XRD, TEM, EDS, FT-IR. and SEM) were applied for characterization of the ErVO4/MnWO4. Next, a selective and sensitive nanostructured sensor based on ErVO4/MnWO(4 )nanocomposite modified carbon paste electrode (ErVO4/MnWO4/CPE) was constructed for electrochemical detection of tyrosine (Tyr). The electrochemical characterizations were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Compared with the unmodified CPE, the oxidation peak current was significantly enhanced for Tyr. The impact of effective parameters on voltammetric response of Tyr was analyzed with design of experiments (DOE) and response surface methodology (RSM). Under the optimized conditions, the oxidation peak current of Tyr was linear over a range of 0.08-400.0 mu M with a detection limit of 7.7 nM. Finally, the usage of the proposed method was confirmed by the recovery tests of Tyr in biological samples. (C) 2019 Published by Elsevier Ltd

Nanomicellar-curcumin exerts its therapeutic effects via affecting angiogenesis, apoptosis, and T cells in a mouse model of melanoma lung metastasis

Background: Curcumin is a natural phytochemical polyphenol with significant anti-cancer effects and negligible side effects. In this study, the therapeutic capacity of nanomicellar-curcumin for treating lung metastasis was evaluated in an immunocompetent mouse model of metastatic melanoma. Martials and methods: Two doses of nanomicellar-curcumin (i.e. 10 and 20 μM) were used to induce cytotoxicity in 3 melanoma cell lines. A total of 60 mice were allocated to 20 mice in each of three groups (10 for survival and 10 for assays). Groups were no treatment control, PBS control, nanomicellar-curcumin 20 mg/kg IP 4 times a week, for three weeks). Immunohistochemistry, TUNEL assay, and Western blots were used on lung samples. Results: Nanomicellar-curcumin inhibited the in vitro growth of B16 F10 melanoma cells at 20 μM over 72 h. In vivo, 20 mg/kg nanomicellar-curcumin injected IP, delayed tumor cell growth and significantly extended mouse survival rate. Tumor infiltration of regulatory T cells and angiogenesis were reduced, while IFN-γ and CXCL10 were increased. Conclusion: Nanomicellar-curcumin can inhibit lung metastasis and growing melanoma via activation of apoptosis, activated T cells and inhibition of angiogenesis, tumor growth and regulatory T cells. © 2020 Elsevier Gmb

GGA function is required for maturation of neuroendocrine secretory granules

Secretory granule (SG) maturation has been proposed to involve formation of clathrin-coated vesicles (CCVs) from immature SGs (ISGs). We tested the effect of inhibiting CCV budding by using the clathrin adaptor GGA (Golgi-associated, γ-ear-containing, ADP-ribosylation factor-binding protein) on SG maturation in neuroendocrine cells. Overexpression of a truncated, GFP-tagged GGA, VHS (Vps27, Hrs, Stam)-GAT (GGA and target of myb (TOM))-GFP led to retention of MPR, VAMP4, and syntaxin 6 in mature SGs (MSGs), suggesting that CCV budding from ISGs is inhibited by the SG-localizing VHS-GAT-GFP. Furthermore, VHS-GAT-GFP-overexpression disrupts prohormone convertase 2 (PC2) autocatalytic cleavage, processing of secretogranin II to its product p18, and the correlation between PC2 and p18 levels. All these effects were not observed if full-length GGA1-GFP was overexpressed. Neither GGA1-GFP nor VHS-GAT-GFP perturbed SG protein budding from the TGN, or homotypic fusion of ISGs. Reducing GGA3 levels by using short interfering (si)RNA also led to VAMP4 retention in SGs, and inhibition of PC2 activity. Our results suggest that inhibition of CCV budding from ISGs downregulates the sorting from the ISGs and perturbs the intragranular activity of PC2