A Reliable High-Throughput Screening Model for Antidepressant.

Depression is the most frequent affective disorder and is the leading cause of disability worldwide. In order to screen antidepressants and explore molecular mechanisms, a variety of animal models were used in experiments, but there is no reliable high-throughput screening method. Zebrafish is a common model organism for mental illness such as depression. In our research, we established chronic unpredictable mild stress (CUMS) models in C57BL/6 mice and zebrafish; the similarities in behavior and pathology suggest that zebrafish can replace rodents as high-throughput screening organisms. Stress mice (ip., 1 mg/kg/d, 3 days) and zebrafish (10 mg/L, 20 min) were treated with reserpine. As a result, reserpine caused depression-like behavior in mice, which was consistent with the results of the CUMS mice model. Additionally, reserpine reduced the locomotor ability and exploratory behavior of zebrafish, which was consistent with the results of the CUMS zebrafish model. Further analysis of the metabolic differences showed that the reserpine-induced zebrafish depression model was similar to the reserpine mice model and the CUMS mice model in the tyrosine metabolism pathway. The above results showed that the reserpine-induced depression zebrafish model was similar to the CUMS model from phenotype to internal metabolic changes and can replace the CUMS model for antidepressants screening. Moreover, the results from this model were obtained in a short time, which can shorten the cycle of drug screening and achieve high-throughput screening. Therefore, we believe it is a reliable high-throughput screening model.

A Small ß-Carboline Derivative "B-9-3" Modulates TGF-ß Signaling Pathway Causing Tumor Regression in Vivo.

Targeting tumor microenvironment (TME) is crucial in order to overcome the anti-cancer therapy resistance. In this study, we report the antitumor activity of a newly synthesized ß-carboline derivative "B-9-3." Here, this small molecule showed a promising antitumor activity in vivo along with an enhanced immune response as reflected by a reduction of regulatory T cells and increased CD4+/CD8+ T cells. Further, B-9-3 decreased the number of myofibroblasts not only in the tumor but also in the lung suggesting an anti-metastatic action. The reduction of myofibroblasts was associated with lower expression of epithelial-to-mesenchymal transition markers and a decrease of phosphorylated SMAD2/3 complex indicating the implication of TGF-ß signaling pathway in B-9-3's effect. The blockade of myofibroblasts induction by B-9-3 was also verified in vitro in human fibroblasts treated with TGF-ß. To elucidate the mechanism of B-9-3's action on TGF-ß pathway, first, we investigated the molecular interaction between B-9-3 and TGF-ß receptors using docking method. Data showed a weak interaction of B-9-3 with the ATP-binding pocket of TGFßRI but a strong one with a ternary complex formed of extracellular domains of TGFßRI, TGFßRII, and TGF-ß. In addition, the role of TGFßRI and TGFßRII in B-9-3's activity was explored in vitro. B-9-3 did not decrease any of the two receptors' protein level and only reduced phosphorylated SMAD2/3 suggesting that its effect was more probably due to its interaction with the ternary complex rather than decreasing the expression of TGF-ß receptors or interfering with their ATP-binding domains. B-9-3 is a small active molecule which acts on the TGF-ß signaling pathway and improves the TME to inhibit the proliferation and the metastasis of the tumor with the potential for clinical application.

Preparation of novel dual-site drug delivery system based on hydroxypropyl methyl cyclodextrin.

An amphipathic copolymer of poly(polyethylene glycol-b-polycaprolactone-co-hydroxypropyl methyl cyclodextrin) [poly(mPEG-b-PCL-co-HPCD)] was synthesized via the free radical polymerization. The copolymer was used to prepare novel nanoparticles (NPs) by a solvent evaporation method. Curcumin (CUR) was selected as a model drug and loaded in the both sites of inner NPs and the cavities of HPCD. 1H nuclear magnetic resonance (1H NMR) study was carried out to confirm the synthesis of poly(mPEG-b-PCL-co-HPCD). The morphology and particle size distribution of the cargo-free NPs were monitored with transmission electron microscopy (TEM) and Malvern particle sizer. The distribution state of CUR in the CUR-loaded NPs was studied with differential scanning calorimetry (DSC) and X-ray diffraction (XRD) methods. The 1H NMR spectrum demonstrated the successful preparation of poly(mPEG-b-PCL-co-HPCD) copolymer. TEM photograph illustrated that the cargo-free NPs had a spherical morphology with an average diameter of 229±32.8nm. The cargo-free NPs had a low critical micelle concentration of 2.9×10-2mg/mL. The HepG2 cells incubated with 1.0mg/mL NPs suspension showed high cell viability. The drug release profile showed that the medicated NPs could continuously release CUR for 24h. Therefore, the poly(mPEG-b-PCL-co-HPCD) NPs had a potential application on the drug delivery.