Bis(benzonitrile) dichloroplatinum (II) interrupts PD-1/PD-L1 interaction by binding to PD-1.

Checkpoint inhibitors such as PD-1/PD-L1 antibody therapeutics are a promising option for the treatment of multiple cancers. Due to the inherent limitations of antibodies, great efforts have been devoted to developing small-molecule PD-1/PD-L1 signaling pathway inhibitors. In this study we established a high-throughput AlphaLISA assay to discover small molecules with new skeletons that could block PD-1/PD-L1 interaction. We screened a small-molecule library of 4169 compounds including natural products, FDA approved drugs and other synthetic compounds. Among the 8 potential hits, we found that cisplatin, a first-line chemotherapeutic drug, reduced AlphaLISA signal with an EC50 of 8.3 ± 2.2 µM. Furthermore, we showed that cisplatin-DMSO adduct, but not semplice cisplatin, inhibited PD-1/PD-L1 interaction. Thus, we assessed several commercial platinum (II) compounds, and found that bis(benzonitrile) dichloroplatinum (II) disturbed PD-1/PD-L1 interaction (EC50 = 13.2 ± 3.5 µM). Its inhibitory activity on PD-1/PD-L1 interaction was confirmed in co-immunoprecipitation and PD-1/PD-L1 signaling pathway blockade bioassays. Surface plasmon resonance assay revealed that bis(benzonitrile) dichloroplatinum (II) bound to PD-1 (KD = 2.08 µM) but not PD-L1. In immune-competent wild-type mice but not in immunodeficient nude mice, bis(benzonitrile) dichloroplatinum (II) (7.5 mg/kg, i.p., every 3 days) significantly suppressed the growth of MC38 colorectal cancer xenografts with increasing tumor-infiltrating T cells. These data highlight that platinum compounds are potential immune checkpoint inhibitors for the treatment of cancers.

Genome-wide identification, characterization, and expression patterns of the BZR transcription factor family in sugar beet (Beta vulgaris L.).

BACKGROUND: BRASSINAZOLE-RESISTANT (BZR) family genes encode plant-specific transcription factors (TFs) that participate in brassinosteroid signal transduction. BZR TFs have vital roles in plant growth, including cell elongation. However, little is known about BZR genes in sugar beet (Beta vulgaris L.). RESULTS: Therefore, we performed a genome-wide investigation of BvBZR genes in sugar beet. Through an analysis of the BES1_N conserved domain, six BvBZR gene family members were identified in the sugar beet genome, which clustered into three subgroups according to a phylogenetic analysis. Each clade was well defined by the conserved motifs, implying that close genetic relationships could be identified among the members of each subfamily. According to chromosomal distribution mapping, 2, 1, 1, 1, and 1 genes were located on chromosomes 1, 4, 5, 6, and 8, respectively. The cis-acting elements related to taproot growth were randomly distributed in the promoter sequences of the BvBZR genes. Tissue-specific expression analyses indicated that all BvBZR genes were expressed in all three major tissue types (roots, stems, and leaves), with significantly higher expression in leaves. Subcellular localization analysis revealed that Bv1_fxre and Bv6_nyuw are localized in the nuclei, consistent with the prediction of Wolf PSORT. CONCLUSION: These findings offer a basis to predict the functions of BZR genes in sugar beet, and lay a foundation for further research of the biological functions of BZR genes in sugar beet.

[Quality Analysis and Evaluation of Anemarrhena asphodeloides Rhizome from Different Habitats].

UNLABELLED: tive: To compare and analyze the quality of Anemarrhena asphodeloides rhizome from different habitats. METHODS: Simultaneous determination of nine components in Anemarrhena asphodeloides rhizome by UPLC-TQ/MS was performed on a Phenomenex Kinetex XB-C18 (100 mm x 2.1 mm, 1.7 µm) column with the mobile phase consisted of 0.1% formic acid-acetonitrile (gradient elution) at the flow rate of 0.4 mL/min and thecolumn temperature at 35 degrees C. Multiple reaction mode detection (MRM) in mode was used in this assay. RESULTS: Nine components were separated totally within 15 min. Good correlation were found between the investigated compounds concentrations and their peak areas within the test ranges with the correlation coefficient from 0.9917 to 0.9992. The average recoveries were from 98.1% to 103.7%, and the RSD of precision was in the range of 1.7% - 4.7%. 0.074-3.620 mg/g for sarsasapogenin, 0.042-2.530 mg/g for timosaponin A III, 22.1- 50.4 mg/g for timosaponon B II, 0.10 -8.28 mg/g for officinalisinin II, 0.64 -7.29 mg/g for anemarsaponin B III, 3.28 -27.40 mg/g for mangiferin, 1.83 - 7.21 mg/g for isomangiferin, 0.36 -9.25 mg/g for neomangiferin and 4.72 x 10(-5) - 1.38 x 10(-3) mg/g for baohuoside I in Anemarrhena asphodeloides rhizome from different habitats were detected. CONCLUSION: The method is rapid, accurate and can be used for quality evaluation of Anemarrhena asphodeloides rhizome. The quality of Anemarrhena asphodeloides rhizome from different habitats are different. The saponins content of Anemarrhena asphodeloides rhizome in Hebei is higher than that of the others.

[Determination of lignans in schisandrae sphenantherae fructus from different regions].

With an objective to provide an experimental basis for scientific officinal of Schisandrae Sphenantherae Fructus, this research uses UPLC-TQ/MS method to analyze 7 different kinds of lignan in 70 batches of Schisandra sphenantherae Fructus samples from 9 regions. The results showed that in the area south of Qinling mountains, Schisandrae sphenantherae Fructus from Zhashui county and Shanyang county of Shangluo mainly contained schisantherin A and deoxyschizandrin. However, Schisandrae sphenantherae Fructus from Mei county of Baoji, Shiquan county and Ningshan county of Ankang, and Lueyang county of Hanzhong, mainly contained anwuligan. Samples from Ningshan county also consists relatively high level of deoxyschizandrin. In the central area of Qinling mountains and the Daba mountains, Schisandrae Sphenantherae Fructus from Nanzheng county of Hanzhong mainly contained schisanhenol and deoxyschizandrin. In conclusion, the kinds and level of lignan differ significantly in Schisandrae sphenantherae Fructus produced in different regions. In practical application, Schisandrae Sphenantherae Fructus produced in different regions should be distinguished and differently applied based on their main effective components corresponding to different diseases, which can lead to the best clinical use.

Synthesis of tigogenin MeON-Neoglycosides and their antitumor activity.

To discover new potent cytotoxic steroidal saponins, a series of tigogenin neoglycosides were synthesized via oxyamine neoglycosylation for the first time. The preliminary bioassays for their in vitro antitumor activities against five human cancer cell lines (A375, A-549, HCT-116, HepG2 and MCF-7) were conducted. The results revealed a sugar-dependent activity profile of their cytotoxicity, the glycoconjugation converted the non-active tigogenin to the most potential product Tg29 ((3R)-N-methoxyamino-tigogenin-ß-2-deoxy-d-galactoside) with IC50 value of 2.7µM and 4.6µM against HepG2 and MCF-7 cells respectively. And the 3R-tigogenin neoglycosides exhibited enhanced antitumor activity while the 3S-tigogenin almost showed no activity. Among the five cell lines, HepG2 and MCF-7 cells showed more sensitive cytotoxic responses to the products. Therefore, the neoglycosylation could be a promising strategy for the synthesis of antitumor steroidal saponins and it also proved the essential role of carbohydrate moiety of steroidal saponins in the biological activity.

Transcriptomic profiling of taproot growth and sucrose accumulation in sugar beet (Beta vulgaris L.) at different developmental stages.

In sugar beet (Beta vulgaris L.), taproot weight and sucrose content are the important determinants of yield and quality. However, high yield and low sucrose content are two tightly bound agronomic traits. The advances in next-generation sequencing technology and the publication of sugar beet genome have provided a method for the study of molecular mechanism underlying the regulation of these two agronomic traits. In this work, we performed comparative transcriptomic analyses in the high taproot yield cultivar SD13829 and the high sucrose content cultivar BS02 at five developmental stages. More than 50,000,000 pair-end clean reads for each library were generated. When taproot turned into the rapid growth stage at the growth stage of 82 days after emergence (DAE), eighteen enriched gene ontology (GO) terms, including cell wall, cytoskeleton, and enzyme linked receptor protein signaling pathway, occurred in both cultivars. Differentially expressed genes (DEGs) of paired comparison in both cultivars were enriched in the cell wall GO term. For pathway enrichment analyses of DEGs that were respectively generated at 82 DAE compared to 59 DAE (the earlier developmental stage before taproot turning into the rapid growth stage), plant hormone signal transduction pathway was enriched. At 82 DAE, the rapid enlarging stage of taproot, several transcription factor family members were up-regulated in both cultivars. An antagonistic expression of brassinosteroid- and auxin-related genes was also detected. In SD13829, the growth strategy was relatively focused on cell enlargement promoted by brassinosteroid signaling, whereas in BS02, it was relatively focused on secondarily cambial cell division regulated by cytokinin, auxin and brassinosteroid signaling. Taken together, our data demonstrate that the weight and sucrose content of taproot rely on its growth strategy, which is controlled by brassinosteroid, auxin, cytokinin, and gibberellin.

[The relationship between activities of chitinase and beta-1,3-glucanase and resistance to rhizomania in sugar beet].

The relationship between activities of chitinase and beta-1,3-glucanase and resistance to rhizomania of sugar beet were studied in diseased soil and disease-free soil by using a method of comparative physiology. Two resistant varieties and two susceptible ones of sugar beet were used in this experiment. Chitinase and beta-1,3-glucanase activities of the resistant varieties were higher than the susceptible ones in either diseased soil or disease-free soil. There is a positive correlation between chitinase, beta-1,3-glucanase activity and yield of beet in diseased soil, suggesting that pathogen infection can induce resistance to rhizomania through activating chitinase and beta-1,3-glucanase.

Potent inhibition of superoxide anion production in activated human neutrophils by isopedicin, a bioactive component of the Chinese medicinal herb Fissistigma oldhamii.

Fissistigma oldhamii is widely used in traditional Chinese medicine to treat rheumatoid arthritis. Activation of neutrophils is a key feature of inflammatory diseases. Herein, the anti-inflammatory functions of isopedicin, a flavanone derived from F. oldhamii, and its underlying mechanisms were investigated in human neutrophils. Isopedicin potently and concentration-dependently inhibited superoxide anion (O(2)(*)(-)) production in formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP)-activated human neutrophils with an IC(50) value of 0.34+/-0.03 microM. Furthermore, isopedicin displayed no superoxide-scavenging ability, and it failed to alter subcellular NADPH oxidase activity. The inhibitory effect of isopedicin on O(2)(*)(-) production was reversed by protein kinase A (PKA) inhibitors. Moreover, isopedicin increased cAMP formation and PKA activity in FMLP-activated human neutrophils, which occurred through the inhibition of phosphodiesterase (PDE) activity but not an increase in adenylate cyclase function. In addition, isopedicin reduced FMLP-induced phosphorylation of extracellular regulated kinase and c-Jun N-terminal kinase, which was reversed by the PKA inhibitor. In contrast, isopedicin failed to alter FMLP-induced phosphorylation of p38 mitogen-activated protein kinase and calcium mobilization. In summary, these results demonstrate that inhibition of O(2)(*)(-) production in human neutrophils by isopedicin is associated with an elevation of cellular cAMP and activation of PKA through its inhibition of cAMP-specific PDE.