Salvianolic acid B exerts its anti-tumor immunity by targeting USP2 and reducing the PD-L1 level / 药学学报

With the development of small-molecule immunotherapy drugs, its combination with the programmed cell death ligand 1/programmed cell death protein 1 (PD-L1/PD-1) antibodies would provide a new opportunity for cancer treatment. Therefore, targeting PD-L1/PD-1 axis by small-molecule drug is an attractive approach to enhance antitumor immunity and considered as the next generation of tumor immunotherapy. In the present study, we investigated the anti-tumor role of salvianolic acid B (SAB) by regulating the PD-L1 level in tumors. Changes of total PD-L1 and membrane PD-L1 levels were determined by Western blot, flow cytometry and PD-1/PD-L1 interaction assays. The expression of mRNA level of PD-L1 was detected by real-time PCR. The cytotoxicity of activated peripheral blood mononuclear cell (PBMC) cells toward co-cultured tumor cells was measured by cell impedance assay and crystal violet experiment. Surface plasma resonance technique was used to analyze the direct interaction between SAB and ubiquitin carboxyl-terminal hydrolase 2 (USP2). The antitumor effect of SAB in vivo was examined by C57BL/6 mice bearing MC38 xenograft tumor (all animal experiments were conducted in accordance with the Animal Ethics Committee of the Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences). Western blot and flow cytometry assay showed that SAB can significantly downregulate the abundance of PD-L1 in RKO and PC3 cells in dose- and time-dependent manner. PD-1/PD-L1 binding assay revealed that SAB reduces the binding of tumor cells to recombinant PD-1 protein. Mechanism studies revealed that SAB can bind directly to USP2 protein and inhibit its activity, thus promote the ubiquitin-proteasome pathway degradation of PD-L1 proteins. In addition, Cell impedance and crystal violet staining indicated that SAB enhances the killing activity of co-cultured PBMC cells toward tumor cells. MC38 tumor transplanted mouse experiments revealed that SAB treatment displayed significant suppression in the growth of MC38 tumor xenografts in C57BL/6 mice with an inhibition rate of 63.2% at 20 mg·kg-1. Our results demonstrate that SAB exerts its anti-tumor activity by direct binding and inhibiting the activity of USP2 and reducing the PD-L1 level. Our study provides an important material basis and scientific basis for the potential application of SAB in tumor immunotherapy drug targeting USP2-PD-L1 axis.

Research progresses on NLRP3 inflammasomes-induced anti-tumor immunity / 药学学报

More and more studies have shown that NOD-like receptor protein 3 (NLRP3) inflammasome has become the regulatory factor of inflammatory response and protective immunity, and the assembly and activation of NLRP3 inflammasomes are closely related to the anti-tumor immunity effect. Depending on the cell type and stimuli, activation of the NLRP3 inflammasome can induce immune cells to become polarized, hyperactive, or pyroptotic, releasing interleukin (IL)-1β and IL-18, which leads to cascade immune or inflammatory responses, and its role in tumor immunity has received extensive attention. Here, we review the mechanisms of the NLRP3 inflammasome enhancing CD8+ T cells-mediated anti-tumor immunity by inducing the pyroptosis of tumor cell, the pyroptosis or hyperactive state of dendritic cells (DCs), and the pyroptosis or polarization of the macrophages. Different anti-tumor immune roles of NLRP3 inflammasome activation in tumor cells and immune cells provide new directions for future research and may influence the development of next-generation immunotherapy.

Design, synthesis and pharmacological investigation of isoindoline derivatives as 5-HT/NE double reuptake inhibitors / 药学学报

A series of isoindoline derivatives were designed, synthesized, and evaluated for their double inhibitory activities. All of them were new compounds, and their structures were confirmed by 1H NMR and HR-MS. Preliminary in vitro pharmacological tests showed that all compounds exhibited 5-HT or NE reuptake inhibition activity. Among the tested compounds, compound I-3 exhibited potent inhibitory activity against 5-HT and NE reuptake in vitro, and exhibited potent antidepressant activity in vivo. These compounds designed can be further optimized for finding more potent 5-HT/NE dual reuptake inhibitors and antidepressant candidates as well.

Evaluation of the sedative and hypnotic effects of H1208 / 药学学报

This study is to investigate the sedative and hypnotic effects of a novel compound H1208. The sedative activity of H1208 was investigated by recording the spontaneous locomotor activity of mice. The hypnotic property was evaluated by the latency and duration of sleep (loss of righting reflex) in mice and the effect of hypnotics on sleep pattern of electroencephalogram were studied in conscious, freely moving mice with chronically implanted electrodes. The brain monoamine neurotransmitters levels in mice were measured by high performance liquid chromatography-electrochemical detection. The spontaneous locomotor activity was decreased by 56.7% and 80.2% in H1208 (5 and 25 mg x kg(-1), ip) treated mice, respectively. The loss of righting reflex was directly induced in mice after H1208 (60 mg x kg(-1), ip) administration. The non-rapid eye movement sleep increased significantly by 131% and 259%, respectively, within 3 hours after H1208 (30 and 60 mg x kg(-1), ip) administration. However, the rapid eye movement sleep decreased significantly. The contents of DA in the striatum and cortex and 5-HT in the cortex decreased significantly. These results demonstrated that H1208 has potent sedative and hypnotic effects, which may be closely related to the decreased contents of DA and 5-HT in mouse brain.