Yongliang Yang

CRM1 Is a Cellular Target of Curcumin: New Insights for the Myriad of Biological Effects of an Ancient Spice

Curcumin is the major constituent of turmeric plant, an ancient spice widely used in Indian cuisine and traditional herbal medicine. Recently, the potential medical use of curcumin as anti‐cancer and anti‐inflammatory agent has set off an upsurge in research into the mechanism for its broad biological effects. We showed that CRM1, an important nuclear exportin, is a cellular target of curcumin by serious experimental and theoretical investigation. Using a nuclear export functional assay, we observed a clear and rapid shift of cargo proteins from a cytoplasmic localization to the nucleus when treated with curcumin or its structural analogue dibenzylideneacetone (DBA). We demonstrated that curcumin could specifically target the conserved Cys528 of CRM1 through mass spectrometric analysis and in vivo experiments. Furthermore, computational modeling has revealed that curcumin could be correctly docked into the hydrophobic pocket of CRM1 judged from shape complementarity and putative molecular interactions. The Michael acceptor moiety on curcumin is within the appropriate distance to enable Michael reaction with Cys residue of CRM1. More importantly, we showed that nuclear retention of FOXO1 could be observed in the presence of Leptomycin B (LMB) or curcumin whereas in cells expressing the CRM1‐Cys528 mutant, only a cytoplasmic localization was observed. The inhibition of nuclear traffic by curcumin may account for its myriad of biological effects, particularly for its therapeutic properties in cancer and inflammatory diseases. Our findings may have important implications for further clinical investigation of curcumin.

A comparison of various optimization algorithms of protein–ligand docking programs by fitness accuracy

In protein–ligand docking, an optimization algorithm is used to find the best binding pose of a ligand against a protein target. This algorithm plays a vital role in determining the docking accuracy. To evaluate the relative performance of different optimization algorithms and provide guidance for real applications, we performed a comparative study on six efficient optimization algorithms, containing two evolutionary algorithm (EA)-based optimizers (LGA, DockDE) and four particle swarm optimization (PSO)-based optimizers (SODock, varCPSO, varCPSO-ls, FIPSDock), which were implemented into the protein–ligand docking program AutoDock. We unified the objective functions by applying the same scoring function, and built a new fitness accuracy as the evaluation criterion that incorporates optimization accuracy, robustness, and efficiency. The varCPSO and varCPSO-ls algorithms show high efficiency with fast convergence speed. However, their accuracy is not optimal, as they cannot reach very low energies. SODock has the highest accuracy and robustness. In addition, SODock shows good performance in efficiency when optimizing drug-like ligands with less than ten rotatable bonds. FIPSDock shows excellent robustness and is close to SODock in accuracy and efficiency. In general, the four PSO-based algorithms show superior performance than the two EA-based algorithms, especially for highly flexible ligands. Our method can be regarded as a reference for the validation of new optimization algorithms in protein–ligand docking.

Recurrent ECSIT mutation encoding V140A triggers hyperinflammation and promotes hemophagocytic syndrome in extranodal NK/T cell lymphoma

Hemophagocytic syndrome (HPS) is a fatal hyperinflammatory disease with a poorly understood mechanism that occurs most frequently in extranodal natural killer/T cell lymphoma (ENKTL). Through exome sequencing of ENKTL tumor–normal samples, we have identified a hotspot mutation (c.419T>C) in the evolutionarily conserved signaling intermediate in Toll pathway (ECSIT) gene, encoding a V140A variant of ECSIT. ECSIT-V140A activated NF-κB more potently than the wild-type protein owing to its increased affinity for the S100A8 and S100A9 heterodimer, which promotes NADPH oxidase activity. ECSIT-T419C knock-in mice showed higher peritoneal NADPH oxidase activity than mice with wild-type ECSIT in response to LPS. ECSIT-T419C-transfected ENKTL cell lines produced tumor necrosis factor (TNF)-α and interferon (IFN)-γ, which induced macrophage activation and massive cytokine secretion in cell culture and mouse xenografts. In individuals with ENKTL, ECSIT-V140A was associated with activation of NF-κB, higher HPS incidence, and poor prognosis. The immunosuppressive drug thalidomide prevented NF-κB from binding to the promoters of its target genes (including TNF and IFNG), and combination treatment with thalidomide and dexamethasone extended survival of mice engrafted with ECSIT-T419C-transfected ENKTL cells. We added thalidomide to the conventional dexamethasone-containing therapy regimen for two patients with HPS who expressed ECSIT-V140A, and we observed reversal of their HPS and disease-free survival for longer than 3 years. These findings provide mechanistic insights and a potential therapeutic strategy for ENKTL-associated HPS.

Structural Bioinformatics-Based Identification of EGFR Inhibitor Gefitinib as a Putative Lead Compound for BACE

β‐secretase (BACE‐1) is a potential target for the treatment of Alzheimers disease (AD). Despite its potential, only few compounds targeting BACE have entered the clinical trials. Herein, we describe the identification of Gefitinib as a potential lead compound for BACE through an integrated approach of structural bioinformatics analysis, experimental assessment and computational analysis. In particular, we performed ELISA and western analysis to assess the effect of Gefitinib using N2a human APP695 cells. In addition, we investigated the binding mechanism of Gefitinib with BACE through molecular docking coupled with molecular dynamics simulations. The computational analyses revealed that hydrophobic contact is a major contributing factor to the binding of Gefitinib with BACE. The results obtained in the study have rendered Gefitinib as a putative lead compound for BACE. Further optimization studies are warranted to improve its potency and pharmacological properties against BACE for potential AD treatment.

Traditional Herbal Medicine-Derived Sulforaphene LFS-01 Reverses Colitis in Mice by Selectively Altering the Gut Microbiota and Promoting Intestinal Gamma-Delta T Cells

Sulforaphene (LFS-01) is a natural compound derived from traditional herbal medicine. Here, we show that oral administration of LFS-01 is able to dramatically alter the skewed gut microbiota and reverse colitis in model mice associated with an increase of intestinal γδT cells. Through 16S rDNA sequencing, we showed that LFS-01 can selectively suppress enteric pathogens such as Escherichia–Shigella and Helicobacter whereas the protective strains including Lactobacillus and Lachnospiraceae were significantly expanded after LFS-01 treatment. Interestingly, we demonstrated that LFS-01 administration can significantly promote the IL-17+γδT cells in model mice in response to the expanded Lactobacillus. We verified that the intracellular components of Lactobacillus can stimulate the growth of IL-17+γδT cells upon preincubation. The increased IL-17A after LFS-01 treatment in turn recovers the disrupted occludin subcellular location and protects the epithelial barrier in the colon of model mice. Remarkably, LFS-01 does not show apparent toxicity to animals and we demonstrated that LFS-01 also exerts strong protective effects in TNBS-induced colitis rats. Therefore, LFS-01 holds great promise for the treatment of inflammatory bowel disease (IBD) and warrants translation for use in clinical trials. Our work provided a new avenue for the treatment of IBD based on the strategy of harnessing intestinal symbiosis.

Cancer Stem Cells Therapeutic Target Database: The First Comprehensive Database for Therapeutic Targets of Cancer Stem Cells

Cancer stem cells (CSCs) are a subpopulation of tumor cells that have strong self‐renewal capabilities and may contribute to the failure of conventional cancer therapies. Hence, therapeutics homing in on CSCs represent a novel and promising approach that may eradicate malignant tumors. However, the lack of information on validated targets of CSCs has greatly hindered the development of CSC‐directed therapeutics. Herein, we describe the Cancer Stem Cells Therapeutic Target Database (CSCTT), the first online database to provide a rich bioinformatics resource for the display, search, and analysis of structure, function, and related annotation for therapeutic targets of cancer stem cells. CSCTT contains 135 proteins that are potential targets of CSCs, with validated experimental evidence manually curated from existing literatures. Proteins are carefully annotated with a detailed description of protein families, biological process, related diseases, and experimental evidences. In addition, CSCTT has compiled 213 documented therapeutic methods for cancer stem cells, including 118 small molecules and 20 biotherapy methods. The CSCTT may serve as a useful platform for the development of CSC‐directed therapeutics against various malignant tumors. The CSCTT database is freely available to the public at http://www.csctt.org/. Stem Cells Translational Medicine 2017;6:331–334

Investigation of Family 18 Chitinases and Inhibitors by Computer-Aided Approaches

Chitinases belong to family 18 glycosyl hydrolases that can hydrolyze chitin by cleaving β-1,4-glycosidic bond, and are at key points in the life cycles of organism. The inhibitors of chitinases not only have chemotherapeutic potential against fungi, insects, but also hold anti-inflammatory efficacy against asthma and allergic disease in human. This review summarizes the structural characters of chitinases, the proposed catalytic mechanism, furthermore, also gives descriptions of currently existing inhibitors. In addition, computational studies of the interaction modes of chitinases with different inhibitors and substrates, as well as the inhibitor design of chitinases, are summarized so as to obtain an overall understanding for chitinases.

Traditional herbal medicine-derived sulforaphene promotes mitophagic cell death in lymphoma cells through CRM1-mediated p62/SQSTM1 accumulation and AMPK activation

Sulforaphene (LFS-01) is the major chemical constituent of Raphanus sativus, a medicinal herb used for over a thousand years in traditional Chinese medicine. Here we identified that LFS-01 can selectively eradicate lymphoma cells while sparing normal lymphocytes by triggering concomitant mitophagy and apoptosis. We demonstrated that LFS-01 can retain Nrf2 in the nucleus by covalently modulating CRM1 and consequently upregulate p62/SQSTM1, an essential structural component of the autophagosomes during mitophagic process. We found that LFS-01 treatment also stimulated AMPK and thereby inhibited the mTOR pathway. On the contrary, we revealed that AMPK inhibition can severely impair the LFS-01-mediated mitophagy. Transcriptomic studies confirmed that 15 autophagy-associated genes such as p62/SQSTM1, VCP and BCL2 were differentially expressed after LFS-01 treatment. Furthermore, protein interactome network analysis revealed that the events of apoptosis and the assembly of autophagy vacuole were significant upon LFS-01 exposure. Lastly, we found that LFS-01 exhibited strong efficacy in xenograft mouse model yet with the lack of apparent toxicity to animals. We concluded that LFS-01 triggered mitophagic cell death via CRM1-mediated p62 overexpression and AMPK activation. Our findings provide new insights into the mechanism of action for LFS-01 and highlight its potential applications in treating major human diseases.