The chromosome-scale reference genome of Rubus chingii Hu provides insight into the biosynthetic pathway of hydrolyzable tannins.

Rubus chingii Hu (Fu-Pen-Zi), a perennial woody plant in the Rosaceae family, is a characteristic traditional Chinese medicinal plant because of its unique pharmacological effects. There are abundant hydrolyzable tannin (HT) components in R. chingii that provide health benefits. Here, an R. chingii chromosome-scale genome and related functional analysis provide insights into the biosynthetic pathway of HTs. In total, sequence data of 231.21 Mb (155 scaffolds with an N50 of 8.2 Mb) were assembled into seven chromosomes with an average length of 31.4 Mb, and 33 130 protein-coding genes were predicted, 89.28% of which were functionally annotated. Evolutionary analysis showed that R. chingii was most closely related to Rubus occidentalis, from which it was predicted to have diverged 22.46 million years ago (Table S8). Comparative genomic analysis showed that there was a tandem gene cluster of UGT, carboxylesterase (CXE) and SCPL genes on chromosome 02 of R. chingii, including 11 CXE, eight UGT, and six SCPL genes, which may be critical for the synthesis of HTs. In vitro enzyme assays indicated that the proteins encoded by the CXE (LG02.4273) and UGT (LG02.4102) genes have tannin hydrolase and gallic acid glycosyltransferase functions, respectively. The genomic sequence of R. chingii will be a valuable resource for comparative genomic analysis within the Rosaceae family and will be useful for understanding the biosynthesis of HTs.

Progress in the development of small molecular inhibitors of the Bruton's tyrosine kinase (BTK) as a promising cancer therapy.

Bruton tyrosine kinase (BTK) is a key kinase in the B cell antigen receptor signal transduction pathway, which is involved in the regulation of the proliferation, differentiation and apoptosis of B cells. BTK has become a significant target for the treatment of hematological malignancies and autoimmune diseases. Ibrutinib, the first-generation BTK inhibitor, has made a great contribution to the treatment of B cell malignant tumors, but there are still some problems such as resistance or miss target of site mutation. Therefore, there is an imperative need to develop novel BTK inhibitors to overcome these problems. Besides, proteolysis targeting chimera (PROTAC) technology has been successfully applied to the development of BTK degradation agents, which has opened a fresh way for the BTK targeted treatment. This paper reviews the biological function of BTK, the discovery and development of BTK targeted drugs as a promising cancer therapy. It mainly reviews the binding sites and structural characteristics of BTK, structure-activity relationships, activity and drug resistance of BTK inhibitors, as well as potential treatment strategies to overcome the resistance of BTK, which provides a reference for the rational design and development of new powerful BTK inhibitors.

Ras/Raf/MEK/ERK pathway axis mediated neurotoxicity induced by high-risk pesticide residue-Avermectin.

Pesticide residues have become a healthy threaten of human beings. Among the pesticides, many of them have neurotoxicity. Extracellular Regulated Protein Kinases (ERK) pathway is an important signaling pathway that regulates a variety of downstream progress. In this work, peach (PRUNUS persica) and cherry (PRUNUS cerasus) were sampled from over 300 plantations in China and assessed for the residue risk. In mechanism studies, high-risk pesticide Avermectin showed a high activity inhibiting three neurotoxicity models, SH-SY5Y, PC-12 and SK-N-SH cells. At protein levels, ERK pathway proteins and their downstream proteins were obviously down-regulated. Moreover, the effects of low-dose Avermectin can be accumulated at protein levels in the low-dose long-term chronic toxicology detection.

Discovery of Novel Diarylamide N-Containing Heterocyclic Derivatives as New Tubulin Polymerization Inhibitors with Anti-Cancer Activity.

Tubulin has been regarded as an attractive and successful molecular target in cancer therapy and drug discovery. Vicinal diaryl is a simple scaffold found in many colchicine site tubulin inhibitors, which is also an important pharmacophoric point of tubulin binding and anti-cancer activity. As the continuation of our research work on colchicine binding site tubulin inhibitors, we designed and synthesized a series of diarylamide N-containing heterocyclic derivatives by the combination of vicinal diaryl core and N-containing heterocyclic skeletons into one hybrid though proper linkers. Among of these compounds, compound 15b containing a 5-methoxyindole group exhibited the most potent inhibitory activity against the tested three human cancer cell lines (MGC-803, PC-3 and EC-109) with IC50 values of 1.56 µM, 3.56 µM and 14.5 µM, respectively. Besides, the SARs of these compounds were preliminarily studied and summarized. The most active compound 15b produced the inhibition of tubulin polymerization in a dose-dependent manner and caused microtubule network disruption in MGC-803 cells. Therefore, compound 15b was identified as a novel tubulin polymerization inhibitor targeting the colchicine binding site. In addition, the results of molecular docking also suggested compound 15b could tightly bind into the colchicine binding site of ß-tubulin.

Drug Discovery Targeting Focal Adhesion Kinase (FAK) as a Promising Cancer Therapy.

FAK is a nonreceptor intracellular tyrosine kinase which plays an important biological function. Many studies have found that FAK is overexpressed in many human cancer cell lines, which promotes tumor cell growth by controlling cell adhesion, migration, proliferation, and survival. Therefore, targeting FAK is considered to be a promising cancer therapy with small molecules. Many FAK inhibitors have been reported as anticancer agents with various mechanisms. Currently, six FAK inhibitors, including GSK-2256098 (Phase I), VS-6063 (Phase II), CEP-37440 (Phase I), VS-6062 (Phase I), VS-4718 (Phase I), and BI-853520 (Phase I) are undergoing clinical trials in different phases. Up to now, there have been many novel FAK inhibitors with anticancer activity reported by different research groups. In addition, FAK degraders have been successfully developed through "proteolysis targeting chimera" (PROTAC) technology, opening up a new way for FAK-targeted therapy. In this paper, the structure and biological function of FAK are reviewed, and we summarize the design, chemical types, and activity of FAK inhibitors according to the development of FAK drugs, which provided the reference for the discovery of new anticancer agents.

Synthesis and Biological Evaluation of Amino Chalcone Derivatives as Antiproliferative Agents.

Chalcone is a common scaffold found in many biologically active compounds. The chalcone scaffold was also frequently utilized to design novel anticancer agents with potent biological efficacy. Aiming to continue the research of effective chalcone derivatives to treat cancers with potent anticancer activity, fourteen amino chalcone derivatives were designed and synthesized. The antiproliferative activity of amino chalcone derivatives was studied in vitro and 5-Fu as a control group. Some of the compounds showed moderate to good activity against three human cancer cells (MGC-803, HCT-116 and MCF-7 cells) and compound 13e displayed the best antiproliferative activity against MGC-803 cells, HCT-116 cells and MCF-7 cells with IC50 values of 1.52 µM (MGC-803), 1.83 µM (HCT-116) and 2.54 µM (MCF-7), respectively which was more potent than the positive control (5-Fu). Further mechanism studies were explored. The results of cell colony formatting assay suggested compound 10e inhibited the colony formation of MGC-803 cells. DAPI fluorescent staining and flow cytometry assay showed compound 13e induced MGC-803 cells apoptosis. Western blotting experiment indicated compound 13e induced cell apoptosis via the extrinsic/intrinsic apoptosis pathway in MGC-803 cells. Therefore, compound 13e might be a valuable lead compound as antiproliferative agents and amino chalcone derivatives worth further effort to improve amino chalcone derivatives' potency.

Monoclonal antibody-based colloid gold immunochromatographic strip for the rapid detection of Tomato zonate spot tospovirus.

BACKGROUND: Tomato zonate spot virus (TZSV), a new species of genus Tospovirus, caused significant losses in yield and problems in quality of many important vegetables and ornamentals in Southwest China and posed a serious threat to important economic crops for the local farmers. A convenient and reliable method was urgently needed for rapid detection and surveillance of TZSV. METHODS: The nucleocapsid protein (N) of TZSV was expressed in Escherichia coli and purified, and was used as the antigen to immunize BALB/c mice. Three monoclonal antibodies (mAbs) 3A2, 5D2 and 5F7 against TZSV were obtained through the hybridoma technique. The mAb 3A2 was conjugated with colloid gold as detecting reagent; mAb 5D2 was coated on a porous nitrocellulose membrane as the detection line and protein A was coated as the control line respectively. The colloid gold immunochromatographic (GICA) strip was assembled. RESULTS: The analysis of Dot-ELISA and Western blot showed that the obtained three independent lines of mAbs 3A2, 5D2 and 5F7 specifically recognized TZSV N. Based on the assembly of GICA strip, the detection of TZSV was achieved by loading the infected sap onto the test strip for visual inspection. The analysis could be completed within 5-10 min. No cross-reaction occurred between TZSV and other tested viruses. The visual detection limit of the test strip for TZSV was 800 fold dilutions of TZSV-infected leaf samples. CONCLUSION: The mAbs were specific and the colloidal GICA strip developed in this study was convenient, fast and reliable for the detection of TZSV. The method could be applied for the rapid diagnosis and surveillance of TZSV in the field.

SAMHD1 Inhibits LINE-1 Retrotransposition by Promoting Stress Granule Formation.

The SAM domain and HD domain containing protein 1 (SAMHD1) inhibits retroviruses, DNA viruses and long interspersed element 1 (LINE-1). Given that in dividing cells, SAMHD1 loses its antiviral function yet still potently restricts LINE-1, we propose that, instead of blocking viral DNA synthesis by virtue of its dNTP triphosphohydrolase activity, SAMHD1 may exploit a different mechanism to control LINE-1. Here, we report a new activity of SAMHD1 in promoting cellular stress granule assembly, which correlates with increased phosphorylation of eIF2α and diminished eIF4A/eIF4G interaction. This function of SAMHD1 enhances sequestration of LINE-1 RNP in stress granules and consequent blockade to LINE-1 retrotransposition. In support of this new mechanism of action, depletion of stress granule marker proteins G3BP1 or TIA1 abrogates stress granule formation and overcomes SAMHD1 inhibition of LINE-1. Together, these data reveal a new mechanism for SAMHD1 to control LINE-1 by activating cellular stress granule pathway.

A neuron-specific antiviral mechanism prevents lethal flaviviral infection of mosquitoes.

Mosquitoes are natural vectors for many etiologic agents of human viral diseases. Mosquito-borne flaviviruses can persistently infect the mosquito central nervous system without causing dramatic pathology or influencing the mosquito behavior and lifespan. The mechanism by which the mosquito nervous system resists flaviviral infection is still largely unknown. Here we report that an Aedes aegypti homologue of the neural factor Hikaru genki (AaHig) efficiently restricts flavivirus infection of the central nervous system. AaHig was predominantly expressed in the mosquito nervous system and localized to the plasma membrane of neural cells. Functional blockade of AaHig enhanced Dengue virus (DENV) and Japanese encephalitis virus (JEV), but not Sindbis virus (SINV), replication in mosquito heads and consequently caused neural apoptosis and a dramatic reduction in the mosquito lifespan. Consistently, delivery of recombinant AaHig to mosquitoes reduced viral infection. Furthermore, the membrane-localized AaHig directly interfaced with a highly conserved motif in the surface envelope proteins of DENV and JEV, and consequently interrupted endocytic viral entry into mosquito cells. Loss of either plasma membrane targeting or virion-binding ability rendered AaHig nonfunctional. Interestingly, Culex pipien pallens Hig also demonstrated a prominent anti-flavivirus activity, suggesting a functionally conserved function for Hig. Our results demonstrate that an evolutionarily conserved antiviral mechanism prevents lethal flaviviral infection of the central nervous system in mosquitoes, and thus may facilitate flaviviral transmission in nature.

Complement-related proteins control the flavivirus infection of Aedes aegypti by inducing antimicrobial peptides.

The complement system functions during the early phase of infection and directly mediates pathogen elimination. The recent identification of complement-like factors in arthropods indicates that this system shares common ancestry in vertebrates and invertebrates as an immune defense mechanism. Thioester (TE)-containing proteins (TEPs), which show high similarity to mammalian complement C3, are thought to play a key role in innate immunity in arthropods. Herein, we report that a viral recognition cascade composed of two complement-related proteins limits the flaviviral infection of Aedes aegypti. An A. aegypti macroglobulin complement-related factor (AaMCR), belonging to the insect TEP family, is a crucial effector in opposing the flaviviral infection of A. aegypti. However, AaMCR does not directly interact with DENV, and its antiviral effect requires an A. aegypti homologue of scavenger receptor-C (AaSR-C), which interacts with DENV and AaMCR simultaneously in vitro and in vivo. Furthermore, recognition of DENV by the AaSR-C/AaMCR axis regulates the expression of antimicrobial peptides (AMPs), which exerts potent anti-DENV activity. Our results both demonstrate the existence of a viral recognition pathway that controls the flaviviral infection by inducing AMPs and offer insights into a previously unappreciated antiviral function of the complement-like system in arthropods.

The roles of direct recognition by animal lectins in antiviral immunity and viral pathogenesis.

Lectins are a group of proteins with carbohydrate recognition activity. Lectins are categorized into many families based on their different cellular locations as well as their specificities for a variety of carbohydrate structures due to the features of their carbohydrate recognition domain (CRD) modules. Many studies have indicated that the direct recognition of particular oligosaccharides on viral components by lectins is important for interactions between hosts and viruses. Herein, we aim to globally review the roles of this recognition by animal lectins in antiviral immune responses and viral pathogenesis. The different classes of mammalian lectins can either recognize carbohydrates to activate host immunity for viral elimination or can exploit those carbohydrates as susceptibility factors to facilitate viral entry, replication or assembly. Additionally, some arthropod C-type lectins were recently identified as key susceptibility factors that directly interact with multiple viruses and then facilitate infection. Summarization of the pleiotropic roles of direct viral recognition by animal lectins will benefit our understanding of host-virus interactions and could provide insight into the role of lectins in antiviral drug and vaccine development.

Identification of novel key amino acids at the interface of the transmembrane domains of human BST-2 and HIV-1 Vpu.

BACKGROUND: BST-2 (bone marrow stromal cell antigen 2) is an interferon-inducible protein that inhibits virus release by tethering viral particles to the cell surface. This antiviral activity of BST-2 is antagonized by HIV-1 accessory protein Vpu. Vpu physically interacts with BST-2 through their mutual transmembrane (TM) domains. In this study, we utilized the BRET assay and molecular dynamics (MD) simulation method to further characterize the interaction of BST-2 and Vpu. RESULTS: Amino acids I34, L37, P40 and L41 in the TM domain of BST-2, and L11, A18 and W22 in the TM domain of Vpu were identified to be critical for the interaction between BST-2 and Vpu. The residues P40 in the TM domain of BST-2 and L11 in the TM domain of Vpu were shown, for the first time, to be important for their interaction. Furthermore, triple-amino-acid substitutions, 14-16 (AII to VAA) and 26-28 (IIE to AAA) in Vpu TM, not the single-residue mutation, profoundly disrupted BST-2/Vpu interaction. The results of MD simulation revealed significant conformational changes of the BST-2/Vpu complex as a result of mutating P40 of BST-2 and L11, 14-16 (AII to VAA) and 26-28 (IIE to AAA) of Vpu. In addition, disrupting the interaction between BST-2 and Vpu rendered BST-2 resistant to Vpu antagonization. CONCLUSIONS: Through use of the BRET assay, we identified novel key residues P40 in the TM domain of BST-2 and L11 in the TM domain of Vpu that are important for their interaction. These results add new insights into the molecular mechanism behind BST-2 antagonization by HIV-1 Vpu.

The research progress of SARS-CoV-2 main protease inhibitors from 2020 to 2022.

The novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide. The main protease (Mpro) of SARS-CoV-2 plays a central role in viral replication and transcription and represents an attractive drug target for fighting COVID-19. Many SARS-CoV-2 Mpro inhibitors have been reported, including covalent and noncovalent inhibitors. The SARS-CoV-2 Mpro inhibitor PF-07321332 (Nirmatrelvir) designed by Pfizer has been put on the market. This paper briefly introduces the structural characteristics of SARS-CoV-2 Mpro and summarizes the research progress of SARS-CoV-2 Mpro inhibitors from the aspects of drug repurposing and drug design. These information will provide a basis for the drug development of treating the infection of SARS-CoV-2 and even other coronaviruses in the future.

The role of the structural domains of human BST-2 in inhibiting the release of xenotropic murine leukemia virus-related virus.

BST-2 (bone marrow stromal cell antigen 2) is an interferon-inducible protein that inhibits the release of a variety of enveloped viruses by tethering viral particles to the cell surface. Xenotropic murine leukemia virus-related virus (XMRV) is a gamma-retrovirus that was derived from the recombination of two endogenous murine leukemia viruses during the production of a prostate cell line in mice. In this study, we observed that XMRV was highly sensitive to the inhibition by human BST-2. We were able to determine the structural domains of BST-2 that are essential to restrict XMRV, including the transmembrane domain, the coiled-coil ectodomain, the C-terminal glycosylphosphatidylinositol (GPI) anchor, the two putative N-linked glycosylation sites, and the three extracellular cysteine residues. Protease treatment effectively released XMRV particles into the supernatant, supporting the notion that BST-2 tethered nascent particles to the cell surface. These data suggest that BST-2 poses a strong restriction toward XMRV production.

Discovery of novel tertiary amide derivatives as NEDDylation pathway activators to inhibit the tumor progression in vitro and in vivo.

NEDDylation pathway regulates multiple physiological process, unlike inhibitors, NEDDylation activators are rarely studied. Novel amide derivatives were synthesized and evaluated for antiproliferative activity against MGC803, MCF-7 and PC-3 cells. Among them, Ⅶ-31 displayed the most potent activity with an IC50 value of 94 nmol/L against MGC803 cells. Cellular mechanisms elucidated that Ⅶ-31 inhibited the cell viability, arrested cell cycle at G2/M phase and induced apoptosis via intrinsic and extrinsic pathways against MGC803 cells. In addition, Ⅶ-31 activated NAE1-Ubc12-Cullin1 NEDDylation via interacting with NAE1 directly. Furthermore, the activation of NEDDylation resulted in the degradation of inhibitor of apoptosis proteins (IAPs). Importantly, Ⅶ-31 inhibited tumor growth in xenograft models in vivo without the apparent toxicity. In summary, it is the first time to reveal that Ⅶ-31 deserves consideration for cancer therapy as a NEDDylation activator.

Development of a dual-functional conjugate of antigenic peptide and Fc-III mimetics (DCAF) for targeted antibody blocking.

Targeted antibody blocking enables characterization of binding sites on immunoglobulin G (IgG), and can efficiently eliminate harmful antibodies from organisms. In this report, we present a novel peptide-denoted as a dual-functional conjugate of antigenic peptide and Fc-III mimetics (DCAF)-for targeted blocking of antibodies. Synthesis of DCAF was achieved by native chemical ligation, and the molecule consists of three functional parts: a specific antigenic peptide, a linker and the Fc-III mimetic peptide, which has a high affinity toward the Fc region of IgG molecules. We demonstrate that DCAF binds the cognate antibody with high selectivity by simultaneously binding to the Fab and Fc regions of IgG. Animal experiments revealed that DCAF molecules diminish the antibody-dependent enhancement effect in a dengue virus infection model, and rescue the acetylcholine receptor by inhibiting the complement cascade in a myasthenia gravis model. These results suggest that DCAFs could have utility in the development of new therapeutics against harmful antibodies.

[Synergic effects of Danggui Buxue Decoction in reducing toxicity of cytoxan in tumor-bearing mice].

OBJECTIVE: To study the inhibitory effect of Danggui Buxue Tang (DBT), a compound traditional Chinese herbal medicine for supplementing blood, on tumor growth in tumor-bearing mice after inoculation of EL-4 cells, and its immune mechanism as well as its synergic effect in reducing toxicity of cytoxan (CTX). METHODS: Experiment was carried out in tumor-bearing mice after inoculation of EL-4 cells. The mice were randomly divided into four groups after 7 days of the inoculation: untreated group, DBT-treated group [24 g/(kg x d)], CTX-treated group [7.5 mg/(kg x d)] and DBT plus CTX-treated group, with another ten normal mice as control. Inhibitory rate of tumor growth, survival time, immune function and variability of blood cells were measured in the mice during the experiment. RESULTS: After treatment of relevant interventions for 15 days, the tumor in the DBT-treated group, CTX-treated group and DBT plus CTX-treated group grew slower than the untreated group (P<0.05). Murine survival time in the DBT-treated group, CTX-treated group and DBT plus CTX-treated group was lengthened as compared with that in the untreated group (P<0.05). Compared with the untreated group, all kinds of immune indexes in the DBT-treated group and DBT plus CTX-treated group were significantly improved (P<0.05), while the immune indexes in the CTX-treated group were decreased (P<0.05). Compared with the CTX-treated group, all kinds of immune indexes in the DBT plus CTX-treated group were significantly improved (P<0.05). CONCLUSIONS: DBT can enhance the immune function in tumor-bearing mice and the inhibitory effect of DBT on tumor growth is related to the enhanced immune response. DBT can also increase the therapeutic effects and reduce the side effects of CTX.

Progress towards understanding the pathogenesis of dengue hemorrhagic fever.

Dengue virus (DENV) is a mosquito-borne virus belonging to the Flaviviridae family. There are 4 serotypes of DENV that cause human disease through transmission by mosquito vectors. DENV infection results in a broad spectrum of clinical symptoms, ranging from mild fever to dengue hemorrhagic fever (DHF), the latter of which can progress to dengue shock syndrome (DSS) and death. Researchers have made unremitting efforts over the last half-century to understand DHF pathogenesis. DHF is probably caused by multiple factors, such as virus-specific antibodies, viral antigens and host immune responses. This review summarizes the current progress of studies on DHF pathogenesis, which may provide important information for achieving effective control of dengue in the future.

Regulation of Antimicrobial Peptides in Aedes aegypti Aag2 Cells.

Antimicrobial peptides (AMPs) are an important group of immune effectors that play a role in combating microbial infections in invertebrates. Most of the current information on the regulation of insect AMPs in microbial infection have been gained from Drosophila, and their regulation in other insects are still not completely understood. Here, we generated an AMP induction profile in response to infections with some Gram-negative, -positive bacteria, and fungi in Aedes aegypti embryonic Aag2 cells. Most of the AMP inductions caused by the gram-negative bacteria was controlled by the Immune deficiency (Imd) pathway; nonetheless, Gambicin, an AMP gene discovered only in mosquitoes, was combinatorially regulated by the Imd, Toll and JAK-STAT pathways in the Aag2 cells. Gambicin promoter analyses including specific sequence motif deletions implicated these three pathways in Gambicin activity, as shown by a luciferase assay. Moreover, the recognition between Rel1 (refer to Dif/Dorsal in Drosophila) and STAT and their regulatory sites at the Gambicin promoter site was validated by a super-shift electrophoretic mobility shift assay (EMSA). Our study provides information that increases our understanding of the regulation of AMPs in response to microbial infections in mosquitoes. And it is a new finding that the A. aegypti AMPs are mainly regulated Imd pathway only, which is quite different from the previous understanding obtained from Drosophila.

Molecular detection of watermelon mosaic virus associated with a serious mosaic disease on Cucurbita pepo L. in Shanxi, China.

With continued expansion of Cucurbita pepo L. cultivation, viral diseases affecting the crop have become more serious in recent years, causing enormous losses in yield and quality. A virus sample was obtained from Wenshui in Shanxi province, China. Double-stranded RNA technology and sequence-independent amplification (SIA) were used to identify the virus that induced C. pepo L. mosaic disease. SIA and sequencing results showed the presence of watermelon mosaic virus (WMV) in diseased C. pepo L. leaves. The complete sequence of WMV from the Shanxi isolate (i.e., WMV-WS) was cloned and analyzed for further characterization. The genomic RNA of WMV-WS is 10,040 nucleotides in length and encodes a putative polyprotein of 3218 amino acids. Phylogenetic analysis indicate that all WMV isolates were divided into four groups and WMV-WS isolate belong to Group 4. Further analysis showed that these WMV isolates were not only to a certain degree related to the host, but also related to geographical origin of isolates. Our results provide information for a better understanding of the genetic diversity of WMV isolates infecting C. pepo L. in Shanxi, China.