RNAi efficiency is enhanced through knockdown of double-stranded RNA-degrading enzymes in butterfly Papilio xuthus.

The efficiency of RNA interference (RNAi) has always limited the research on the phenotype innovation of Lepidoptera insects. Previous studies have found that double-stranded RNA-degrading enzyme (dsRNase) is an important factor in RNAi efficiency, but there have been no relevant reports in butterflies (Papilionoidea). Papilio xuthus is one of the important models in butterflies with an extensive experimental application value. To explore the effect of dsRNase in the RNAi efficiency on butterflies, six dsRNase genes (PxdsRNase 1-6) were identified in P. xuthus genome, and their dsRNA-degrading activities were subsequently detected by ex vivo assays. The result shows that the dsRNA-degrading ability of gut content (<1 h) was higher than hemolymph content (>12 h). We then investigated the expression patterns of these PxdsRNase genes during different tissues and developmental stages, and related RNAi experiments were carried out. Our results show that different PxdsRNase genes had different expression levels at different developmental stages and tissues. The expression of PxdsRNase2, PxdsRNase3, and PxdsRNase6 were upregulated significantly through dsGFP injection, and PxdsRNase genes can be silenced effectively by injecting their corresponding dsRNA. RNAi-of-RNAi studies with PxEbony, which acts as a reporter gene, observed that silencing PxdsRNase genes can increase RNAi efficiency significantly. These results confirm that silencing dsRNase genes can improve RNAi efficiency in P. xuthus significantly, providing a reference for the functional study of insects such as butterflies with low RNAi efficiency.

Triptolide induces PANoptosis in macrophages and causes organ injury in mice.

Macrophages represent the first lines of innate defense against pathogenic infections and are poised to undergo multiple forms of regulated cell death (RCD) upon infections or toxic stimuli, leading to multiple organ injury. Triptolide, an active compound isolated from Tripterygium wilfordii Hook F., possesses various pharmacological activities including anti-tumor and anti-inflammatory effects, but its applications have been hampered by toxic adverse effects. It remains unknown whether and how triptolide induces different forms of RCD in macrophages. In this study, we showed that triptolide exhibited significant cytotoxicity on cultured macrophages in vitro, which was associated with multiple forms of lytic cell death that could not be fully suppressed by any one specific inhibitor for a single form of RCD. Consistently, triptolide induced the simultaneous activation of pyroptotic, apoptotic and necroptotic hallmarks, which was accompanied by the co-localization of ASC specks respectively with RIPK3 or caspase-8 as well as their interaction with each other, indicating the formation of PANoptosome and thus the induction of PANoptosis. Triptolide-induced PANoptosis was associated with mitochondrial dysfunction and ROS production. PANoptosis was also induced by triptolide in mouse peritoneal macrophages in vivo. Furthermore, triptolide caused kidney and liver injury, which was associated with systemic inflammatory responses and the activation of hallmarks for PANoptosis in vivo. Collectively, our data reveal that triptolide induces PANoptosis in macrophages in vitro and exhibits nephrotoxicity and hepatotoxicity associated with induction of PANoptosis in vivo, suggesting a new avenue to alleviate triptolide's toxicity by harnessing PANoptosis.

Dimethyl fumarate inhibits necroptosis and alleviates systemic inflammatory response syndrome by blocking the RIPK1-RIPK3-MLKL axis.

Necroptosis has been implicated in various inflammatory diseases including tumor-necrosis factor-α (TNF-α)-induced systemic inflammatory response syndrome (SIRS). Dimethyl fumarate (DMF), a first-line drug for treating relapsing-remitting multiple sclerosis (RRMS), has been shown to be effective against various inflammatory diseases. However, it is still unclear whether DMF can inhibit necroptosis and confer protection against SIRS. In this study, we found that DMF significantly inhibited necroptotic cell death in macrophages induced by different necroptotic stimulations. Both the autophosphorylation of receptor-interacting serine/threonine kinase 1 (RIPK1) and RIPK3 and the downstream phosphorylation and oligomerization of MLKL were robustly suppressed by DMF. Accompanying the suppression of necroptotic signaling, DMF blocked the mitochondrial reverse electron transport (RET) induced by necroptotic stimulation, which was associated with its electrophilic property. Several well-known anti-RET reagents also markedly inhibited the activation of the RIPK1-RIPK3-MLKL axis accompanied by decreased necrotic cell death, indicating a critical role of RET in necroptotic signaling. DMF and other anti-RET reagents suppressed the ubiquitination of RIPK1 and RIPK3, and they attenuated the formation of necrosome. Moreover, oral administration of DMF significantly alleviated the severity of TNF-α-induced SIRS in mice. Consistent with this, DMF mitigated TNF-α-induced cecal, uterine, and lung damage accompanied by diminished RIPK3-MLKL signaling. Collectively, DMF represents a new necroptosis inhibitor that suppresses the RIPK1-RIPK3-MLKL axis through blocking mitochondrial RET. Our study highlights DMF's potential therapeutic applications for treating SIRS-associated diseases.

Theaflavin mitigates acute gouty peritonitis and septic organ injury in mice by suppressing NLRP3 inflammasome assembly.

Activation of NLR family pyrin domain-containing 3 (NLRP3) inflammasome plays important role in defending against infections, but its aberrant activation is causally linked to many inflammatory diseases, thus being a therapeutic target for these diseases. Theaflavin, one major ingredient of black tea, exhibits potent anti-inflammatory and anti-oxidative activities. In this study, we investigated the therapeutic effects of theaflavin against NLRP3 inflammasome activation in macrophages in vitro and in animal models of related diseases. We showed that theaflavin (50, 100, 200 µM) dose-dependently inhibited NLRP3 inflammasome activation in LPS-primed macrophages stimulated with ATP, nigericin or monosodium urate crystals (MSU), evidenced by reduced release of caspase-1p10 and mature interleukin-1ß (IL-1ß). Theaflavin treatment also inhibited pyroptosis as shown by decreased generation of N-terminal fragment of gasdermin D (GSDMD-NT) and propidium iodide incorporation. Consistent with these, theaflavin treatment suppressed ASC speck formation and oligomerization in macrophages stimulated with ATP or nigericin, suggesting reduced inflammasome assembly. We revealed that theaflavin-induced inhibition on NLRP3 inflammasome assembly and pyroptosis resulted from ameliorated mitochondrial dysfunction and reduced mitochondrial ROS production, thereby suppressing interaction between NLRP3 and NEK7 downstream of ROS. Moreover, we showed that oral administration of theaflavin significantly attenuated MSU-induced mouse peritonitis and improved the survival of mice with bacterial sepsis. Consistently, theaflavin administration significantly reduced serum levels of inflammatory cytokines including IL-1ß and attenuated liver inflammation and renal injury of mice with sepsis, concomitant with reduced generation of caspase-1p10 and GSDMD-NT in the liver and kidney. Together, we demonstrate that theaflavin suppresses NLRP3 inflammasome activation and pyroptosis by protecting mitochondrial function, thus mitigating acute gouty peritonitis and bacterial sepsis in mice, highlighting a potential application in treating NLRP3 inflammasome-related diseases.

Discovery of novel microtubule stabilizers targeting taxane binding site by applying molecular docking, molecular dynamics simulation, and anticancer activity testing.

Disruption of the dynamic equilibrium of microtubules can induce cell cycle arrest in G2/M phase and apoptosis. Hence, discovery of novel tubulin polymerization inhibitors is very necessary and an important task in drug research and development for treatment of various tumors. In this investigation, 50 compounds were screened as microtubule stabilizers targeting the taxane site by combination of molecular docking methods. Among these hits, hits 19 and 38 with novel scaffolds exhibited the highest anti-proliferative activity with IC50 ranging from 9.50 to 13.81 µM in four cancer cell lines. The molecular dynamics simulations confirmed that tubulin and two hits could form stable systems. Meanwhile, the mechanism of the interactions between tubulin and two hits at simulated physiological conditions were probed. The in vitro tubulin polymerization assay revealed hits 19 and 38 were able to promote tubulin polymerization in a dose-dependent manner. Further, the immunofluorescence assay suggested that hits 19 and 38 could accelerate microtubule assembly in A549 and HeLa cells. Finally, studies on antitumor activity indicated that hits 19 and 38 induced G2/M phase cell cycle arrest and apoptosis, and inhibited cancer cell motility and migration in A549 and HeLa cells. Importantly, hit38 exhibited better anti-tubulin and anti-cancer activity than hit19 in A549 and HeLa cells. Therefore, these results suggest that hit38 represents a promising microtubule stabilizer for treating cancer and deserves further investigation.

Molecular Studies of Relationships and Identifications Among Insects of the Subfamily Panchaetothripinae (Thysanoptera, Thripidae).

The Panchaetothripinae comprises 42 genera and 146 species of leaf-feeding thrips, some of which are horticultural pests. We examined representatives of the 18 genera that include most of these pests. For species delimitation, we used DNA barcoding to produce171 sequences for 40 morphospecies. Most species were found to be monophyletic, although cryptic diversity was evident in 8 presumptive species. A multilocus molecular phylogenetic assessment was based on one mitochondrial (COI) and three nuclear loci (EF-1α, ITS2, and 28S) from 132 specimens (18 genera and 33 species), representing all genera and ~82% of species in China. Maximum likelihood (ML) and Bayesian inference (BI) confirmed monophyly of each genus with strong support. Monophyly of tribes Panchaetothripini and Monilothripini were refuted, but the well supported tribe Tryphactothripini was confirmed. Rhipiphorothrips was recovered as a sister to the remainder of the genera of Panchaetothripinae combined. Both analyses revealed two major clades. Clade A comprised the majority of the genera, including tribe Tryphactothripini. Clade B included only four genera of which two, Helionothrips and Caliothrips, are particularly species rich. The relationships of some genera remain unresolved.

Identification of Novel Inhibitors Targeting SGK1 via Ensemble-Based Virtual Screening Method, Biological Evaluation and Molecular Dynamics Simulation.

Serum and glucocorticoid-regulated kinase 1 (SGK1), as a serine threonine protein kinase of the AGC family, regulates different enzymes, transcription factors, ion channels, transporters, and cell proliferation and apoptosis. Inhibition of SGK1 is considered as a valuable approach for the treatment of various metabolic diseases. In this investigation, virtual screening methods, including pharmacophore models, Bayesian classifiers, and molecular docking, were combined to discover novel inhibitors of SGK1 from the database with 29,158 compounds. Then, the screened compounds were subjected to ADME/T, PAINS and drug-likeness analysis. Finally, 28 compounds with potential inhibition activity against SGK1 were selected for biological evaluation. The kinase inhibition activity test revealed that among these 28 hits, hit15 exhibited the highest inhibition activity against SGK1, which gave 44.79% inhibition rate at the concentration of 10 µM. In order to further investigate the interaction mechanism of hit15 and SGK1 at simulated physiological conditions, a molecular dynamics simulation was performed. The molecular dynamics simulation demonstrated that hit15 could bind to the active site of SGK1 and form stable interactions with key residues, such as Tyr178, ILE179, and VAL112. The binding free energy of the SGK1-hit15 was -48.90 kJ mol-1. Therefore, the identified hit15 with novel scaffold may be a promising lead compound for development of new SGK1 inhibitors for various diseases treatment.

[Analysis of CiteSpace knowledge map for traditional Chinese medicine prevention and treatment of cerebral small vessel diseases].

This study aims to analyze the research on the prevention and treatment of cerebral small vessel diseases(CSVDs) with traditional Chinese medicine(TCM) based on knowledge map, and to preliminarily explore the research hotspots and trends. To be specific, articles on TCM treatment of CSVDs in CNKI, Wanfang, and VIP(from establishment to November 2021) were retrieved, followed by bibliometric analysis. Then CiteSpace 5.7 R4 and Gephi were employed for generation of maps on annual number of articles, author cooperation, institution cooperation, keyword co-occurrence, keyword clustering, and keyword emergence. A total of 106 eligible articles were screened out, and the annual number of articles presented a steady upward trend. A total of 277 authors were included in the author cooperation network, among whom CHEN Zhigang published the most articles. A total of 87 institutions were included in the institution cooperation network, among which Dongfang Hospital of Beijing University of Chinese Medicine showed the most frequent cooperation with other institutions. Keyword clustering showed that research on the TCM treatment of CSVDs mainly focused on five aspects: related disease research, neurological function deficits, disease nature and location in TCM, TCM treatment methods, and formulas. The prevention and treatment of CSVDs with TCM in China has been developing steadily in the past ten years, and TCM has unique advantages in the prevention and treatment of this disease. The knowledge maps vividly demonstrated the development and research hotspots and trends in this field. The result is expected to provide a reference for further research in this field.

Distinctive evolutionary pattern of organelle genomes linked to the nuclear genome in Selaginellaceae.

Plastids and mitochondria are endosymbiotic organelles that store genetic information. The genomes of these organelles generally exhibit contrasting patterns regarding genome architecture and genetic content. However, they have similar genetic features in Selaginellaceae, and little is known about what causes parallel evolution. Here, we document the multipartite plastid genomes (plastomes) and the highly divergent mitochondrial genomes (mitogenomes) from spikemoss obtained by combining short- and long-reads. The 188-kb multipartite plastome has three ribosomal operon copies in the master genomic conformation, creating the alternative subgenomic conformation composed of 110- and 78-kb subgenomes. The long-read data indicated that the two different genomic conformations were present in almost equal proportions in the plastomes of Selaginella nipponica. The mitogenome of S. nipponica was assembled into 27 contigs with a total size of 110 kb. All contigs contained directly arranged repeats at both ends, which introduced multiple conformations. Our results showed that plastomes and mitogenomes share high tRNA losses, GC-biased nucleotides, elevated substitution rates and complicated organization. The exploration of nuclear-encoded organelle DNA replication, recombination and repair proteins indicated that, several single-targeted proteins, particularly plastid-targeted recombinase A1, have been lost in Selaginellaceae; conversely, the dual-targeted proteins remain intact. According to the reported function of recombinase A1, we propose that the plastomes of spikemoss often fail to pair homologous sequences during recombination, and the dual-targeted proteins play a key role in the convergent genetic features of plastomes and mitogenomes. Our results provide a distinctive evolutionary pattern of the organelle genomes in Selaginellaceae and evidence of their convergent evolution.

Discovery of novel tubulin inhibitors targeting taxanes site by virtual screening, molecular dynamic simulation, and biological evaluation.

Microtubules play crucial role in process of mitosis and cell proliferation, which have been considered as attractive drug targets for anticancer therapy. The aim of this study was to discover novel and chemically diverse tubulin inhibitors for treatment of cancer. In this investigation, the multilayer virtual screening methods, including common feature pharmacophore model, structure-based pharmacophore model and molecular docking, were developed to screen BioDiversity database with 30,000 compounds. A total of 102 compounds were obtained by the virtual screening, and further filtered by diverse chemical clusters with desired properties and PAINS analysis. Finally, 50 compounds were selected and submitted to the biological evaluation. Among these hits, hits 8 and 30 with novel scaffolds displayed stronger antiproliferative activity on four human tumor cells including Hela, A549, MCF-7, and HepG2. Moreover, the two hits were subsequently submitted to molecular dynamic simulations of 90 ns with the aim of exploring the stability of ligand-protein interactions into the binding pocket, and further probing the mechanism of the interaction between tubulin and hits. The molecular dynamic simulation results revealed there had stronger interactions between tubulin and hits in equilibrium state. Therefore, the hits 8 and 30 have been well characterized as lead compounds for developing new tubulin inhibitors with potential anticancer activity.

Expression and purification of a recombinant ELRL-MAP30 with dual-targeting anti-tumor bioactivity.

MAP30 (Momordica antiviral protein 30kD) is a single-chain Ⅰ-type ribosome inactivating protein with a variety of biological activities, including anti-tumor ability. It was reported that MAP30 would serve as a novel and relatively safe agent for prophylaxis and treatment of liver cancer. To determine whether adding two tumor targeting peptides could improve the antitumor activities of MAP30, we genetically modified MAP30 with an RGD motif and a EGFRi motif, which is a ligand with high affinity for αvß3 integrins and with high affinity for EGFR. The recombinant protein ELRL-MAP30 (rELRL-MAP30) containing a GST-tag was expressed in E. coli. The rELRL-MAP30 was highly expressed in the soluble fraction after induction with 0.15 mM IPTG for 20 h at 16 °C. The purified rELRL-MAP30 appeared as a band on SDS-PAGE. It was identified by western blotting. Cytotoxicity of recombinant protein to HepG2, MDA-MB-231, HUVEC and MCF-7 cells was detected by MTT analysis. Half maximal inhibitory concentration (IC50) values were 54.64 µg/mL, 70.13 µg/mL, 146 µg/mL, 466.4 µg/mL, respectively. Proliferation inhibition assays indicated that rELRL-MAP30 could inhibit the growth of Human liver cancer cell HepG2 effectively. We found that rELRL-MAP30 significantly induced apoptosis in liver cancer cells, as evidenced by nuclear staining of DAPI. In addition, rELRL-MAP30 induced apoptosis in human liver cancer HepG2 cells by up-regulation of Bax as well as down-regulation of Bcl-2. Migration of cell line were markedly inhibited by rELRL-MAP30 in a dose-dependent manner compared to the recombinant MAP30 (rMAP30). In summary, the fusion protein displaying extremely potent cytotoxicity might be highly effective for tumor therapy.

Discovery of novel DGAT1 inhibitors by combination of machine learning methods, pharmacophore model and 3D-QSAR model.

DGAT1 plays a crucial controlling role in triglyceride biosynthetic pathways, which makes it an attractive therapeutic target for obesity. Thus, development of DGAT1 inhibitors with novel chemical scaffolds is desired and important in the drug discovery. In this investigation, the multistep virtual screening methods, including machine learning methods and common feature pharmacophore model, were developed and used to identify novel DGAT1 inhibitors from BioDiversity database with 30,000 compounds. 531 compounds were predicted as DGAT1 inhibitors by combination of machine learning methods comprising of SVM, NB and RP models. Then, 12 agents were filtered from 531 compounds by using the common feature pharmacophore model. The 3D chemical structures of the 12 hits coordinated with surface charges and isosurface have been carefully analyzed by the established 3D-QSAR model. Finally, 8 compounds with desired properties were retained from the final hits and have been assigned to another research group to complete the follow-up compound synthesis and biologic evaluation.

Plastome-based phylogenomics resolves the placement of the sanguinolenta group in the spikemoss of lycophyte (Selaginellaceae).

Selaginellaceae have been shown to be monophyletic in previous studies, and include only the single genus Selaginella. However, the two most recent classifications of the genus disagree in terms of the number of subgenera recognized, and the position of problematic clades such as the "sanguinolenta" group, which has been resolved in quite different positions in different studies. Here, we performed a plastid-genome based phylogenomic analysis of Selaginellaceae to address this problem. The sanguinolenta group, represented here by three species, was resolved as sister to the remaining members of subg. Stachygynandrum. Additionally, subg. Exaltatae, subg. Ericetorum, and subg. Gymnogynum in clade A clustered into a well supported monophyletic clade but with conflicting topology between subgenera inside, which is possibly attributed to the early divergence among them. We uncovered substantial variation in both synonymous (dS) and nonsynonymous (dN) substitution rate, and GC content in plastomes of Selaginellaceae. The values of dS, dN, and GC content were significantly higher than those of other lycophytes (Isoetaceae and Lycopodiaceae). We observed a significant positive correlation between the high GC content, and the elevated dS and dN rates. In addition, the dS and dN values inferred among branches of Selaginellaceae were extremely variable. Our data indicate that this unevenly distributed substitution rate likely reflected relaxed or intensified selection among different lineages, which is possibly related to the inconsistency of the subgeneric phylogenetic topologies of Selaginellaceae.

Directed Repeats Co-occur with Few Short-Dispersed Repeats in Plastid Genome of a Spikemoss, Selaginella vardei (Selaginellaceae, Lycopodiopsida).

BACKGROUND: It is hypothesized that the highly conserved inverted repeats (IR) structure of land plant plastid genomes (plastomes) is beneficial for stabilizing plastome organization, whereas the mechanism of the occurrence and stability maintenance of the recently reported direct repeats (DR) structure is yet awaiting further exploration. Here we describe the DR structure of the Selaginella vardei (Selaginellaceae) plastome, to elucidate the mechanism of DR occurrence and stability maintenance. RESULTS: The plastome of S. vardei is 121,254 bp in length and encodes 76 genes, of which 62 encode proteins, 10 encode tRNAs, and four encode rRNAs. Unexpectedly, the two identical rRNA gene regions (13,893 bp) are arranged in a direct orientation (DR), rather than inverted. Comparing to the IR organization in Isoetes flaccida (Isoetaceae, Lycopodiopsida) plastome, a ca. 50-kb trnN-trnF inversion that spans one DR copy was found in the plastome of S. vardei, which might cause the orientation change. In addition, we find extremely rare short dispersed repeats (SDRs) in the plastomes of S. vardei and its closely related species S. indica. CONCLUSIONS: We suggest that the ca. 50-kb inversion resulted in the DR structure, and the reduction in SDRs plays a key role in maintaining the stability of plastomes with DR structure by avoiding potential secondary recombination. We further confirmed the presence of homologous recombination between DR regions, which are able to generate subgenomes and form diverse multimers. Our study deepens the understanding of Selaginella plastomes and provides new insights into the diverse plastome structures in land plants.

Correction to: Directed Repeats Co-occur with Few Short-Dispersed Repeats in Plastid Genome of a Spikemoss, Selaginella vardei (Selaginellaceae, Lycopodiopsida).

Following the publication of this article [1], the authors reported that the Fig. 2 described in the article had a mistake that two grey blocks in S. moellendorffii was not placed as background color, and in the Fig. 2 legend, chlL-chlN was wrongly written into chlL-chlL. They have therefore provided the following alternative Fig. 2 in this Correction article in order to show the accurate information.

Exercise interventions on patients with end-stage renal disease: a systematic review.

OBJECTIVE:: This study aimed to conduct an up-to-date systematic review of the literature to evaluate the effects of exercise on fatigue, anxiety, depression, physical activity, and quality of life (QOL) in patients with end-stage renal disease. DATA SOURCES:: We searched PubMed (October 2018), Embase (from 1966 to October 2018), Web of Science (from 1900 to October 2018), The Cochrane Library (October 2018), and references of papers. METHODS:: This study includes randomized controlled trials that analyzed the combined effects of exercise intervention on patients with end-stage renal disease. Two reviewers independently screened the retrieved records, extracted data, and assessed the risk of bias for inclusion in the study. The effects of exercise intervention were conducted in the meta-analysis using RevMan 5.3 software. RESULTS:: A total of 614 participants were included in 13 randomized controlled studies. The study revealed that exercise can improve fatigue, anxiety, depression, physical activity, and QOL. The effect value results were as follows: (1) fatigue, -0.97 (95% confidence interval (CI) -1.32 to -0.62, P < 0.00001); (2) anxiety, -0.78 (95% CI -1.17 to -0.39, P < 0.0001); (3) depression, -0.85 (95% CI -1.13 to -0.56, P < 0.00001) (4) physical activity, 38.15 (95% CI 21.20 to 55.10, P < 0.0001); (5) QOL, the physical component of the 36-item Short-Form Health Survey (SF-36), 4.73 (95% CI 1.92 to 7.54, P = 0.0010); and (6) the mental component of the SF-36, 3.42 (95% CI 0.27 to 6.56, P = 0.03). CONCLUSION:: Exercise intervention is more effective in fatigue, anxiety, depression, physical activity, and QOL. However, large-scale randomized controlled trials are needed to confirm the appropriate types of exercise and optimal time for patients with end-stage renal disease.

Combination radiotherapy and cantharidin inhibits lung cancer growth through altering tumor infiltrating lymphocytes.

This study aimed to detect the effect of combination radiotherapy and cantharidin on lung cancer growth. We found that combination therapy with radiotherapy and cantharidin was more effective in inhibiting the tumor growth than radiotherapy or cantharidin alone. It decreased the percentage of CD4+ Tregs and enhanced the percentage of CD8+ T cells, CD4+ Teff cells when comparing to that of single treatment. Combination therapy promoted a great increase in double producing CD8+ T cells and CD4+ Teff cells in tumor infiltrating lymphocytes. Overexpression of CTLA4 reversed the inhibitory action of combination treatment on cancer growth. Our data suggest that combining radiotherapy and cantharidin may have synergistic effects in driving tumor rejection by increasing T-cell infiltration, proliferation and cytokine production.

A remarkable new species and one newly recorded species of genus Oxyartes Stl, 1875 (Phasmida, Lonchodidae, Necrosciinae) from China.

The genus Oxyartes currently comprises 17 taxa, of which 12 are found in China, representing the high diversity in China. This list includes the two species from China as described in this paper. The first is a new remarkable species O. bouxraeuz sp. nov. collected from Gulinqing township, Yunnan. The second is a newly recorded species, O. cresphontes. This species is reported from Mdog, Xizang, China. A key to this genus from China is presented. Type specimens are deposited in the Yunnan Agricultural University (YNAU).

Discovery of potent microtubule-destabilizing agents targeting for colchicine site by virtual screening, biological evaluation, and molecular dynamics simulation.

Microtubule has been considered as attractive therapeutic target for various cancers. Although numerous of chemically diverse compounds targeting to colchicine site have been reported, none of them was approved by Food and Drug Administration. In this investigation, the virtual screening methods, including pharmacophore model, molecular docking, and interaction molecular fingerprints similarity, were applied to discover novel microtubule-destabilizing agents from database with 324,474 compounds. 22 compounds with novel scaffolds were identified as microtubule-destabilizing agents, and then submitted to the biological evaluation. Among these 22 hits, hit4 with novel scaffold represents the best anti-proliferative activity with IC50 ranging from 4.51 to 14.81 µM on four cancer cell lines. The in vitro assays reveal that hit4 can effectively inhibit tubulin assembly, and disrupt the microtubule network in MCF-7 cell at a concentration-dependent manner. Finally, the molecular dynamics simulation analysis exhibits that hit4 can stably bind to colchicine site, interact with key residues, and induce αT5 and ßT7 regions changes. The values of ΔGbind for the tubulin-colchicine and tubulin-hit4 are -172.9±10.5 and -166.0±12.6 kJ·mol-1, respectively. The above results indicate that the hit4 is a novel microtubule destabilizing agent targeting to colchicine-binding site, which could be developed as a promising tubulin polymerization inhibitor with higher activity for cancer therapy.

Discovery of novel S6K1 inhibitors by an ensemble-based virtual screening method and molecular dynamics simulation.

Ribosomal protein S6 kinase beta-1 (S6K1) is considered a potential target for the treatment of various diseases, such as obesity, type II diabetes, and cancer. Development of novel S6K1 inhibitors is an urgent and important task for the medicinal chemists. In this research, an effective ensemble-based virtual screening method, including common feature pharmacophore model, 3D-QSAR pharmacophore model, naïve Bayes classifier model, and molecular docking, was applied to discover potential S6K1 inhibitors from BioDiversity database with 29,158 compounds. Finally, 7 hits displayed considerable properties and considered as potential inhibitors against S6K1. Further, carefully analyzing the interactions between these 7 hits and key residues in the S6K1 active site, and comparing them with the reference compound PF-4708671, it was found that 2 hits exhibited better binding patterns. In order to further investigate the mechanism of the interactions between 2 hits and S6K1 at simulated physiological conditions, the molecular dynamics simulation was performed. The ΔGbind energies for S6K1-Hit1 and S6K1-Hit2 were - 111.47 ± 1.29 and - 54.29 ± 1.19 kJ mol-1, respectively. Furthermore, deep analysis of these results revealed that Hit1 was the most stable complex, which can stably bind to S6K1 active site, interact with all of the key residues, and induce H1, H2, and M-loop regions changes. Therefore, the identified Hit1 may be a promising lead compound for developing new S6K1 inhibitor for various metabolic diseases treatment.