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2.
Health Serv Res Manag Epidemiol ; 11: 23333928241240970, 2024.
Article En | MEDLINE | ID: mdl-38572165

Older patients with loneliness are connected to others through their social network ties and are, therefore, more likely to be influenced by their family environment. We define collateral care as involving the family members of patients suffering from loneliness. This research letter determines what physicians and nurses should be aware of in the families of older patients to manage their health care. A cross-sectional study in Japan was conducted on patients aged 65 years or older together with their accompanying family members, aged 18 years or older. Patient loneliness was assessed using the 3-item version of the UCLA (University of California, Los Angeles) Loneliness Scale (Japanese). The sample comprised 50 pairs of patients and their families. Family income inadequacy was significantly associated with patient loneliness (P = .021). Our data reveal the family's financial instability contributes to patients' loneliness. In addition to traditional forms of direct care, physicians and nurses need to be willing to manage the loneliness of older patients by attempting to provide collateral care, considering family circumstances.

3.
Biochem Pharmacol ; 215: 115730, 2023 09.
Article En | MEDLINE | ID: mdl-37543348

The E3 ubiquitin ligase RFFL is an apoptotic inhibitor highly expressed in cancers and its knockdown suppresses cancer cell growth and sensitizes to chemotherapy. RFFL also participates in peripheral protein quality control which removes the functional cell surface ΔF508-CFTR channel and reduces the efficacy of pharmaceutical therapy for cystic fibrosis (CF). Although RFFL inhibitors have therapeutic potential for both cancer and CF, they remain undiscovered. Here, a chemical array screening has identified α-tocopherol succinate (αTOS) as an RFFL ligand. NMR analysis revealed that αTOS directly binds to RFFL's substrate-binding region without affecting the E3 enzymatic activity. Consequently, αTOS inhibits the RFFL-substrate interaction, ΔF508-CFTR ubiquitination and elimination from the plasma membrane of epithelial cells, resulting in the increased functional CFTR channel. Among the α-tocopherol (αTOL) analogs we tested, only αTOS inhibited the RFFL-substrate interaction and increased the cell surface ΔF508-CFTR, depending on RFFL expression. Similarly, the unique proapoptotic effect of αTOS was dependent on RFFL expression. Thus, unlike other αTOL analogs, αTOS acts as an RFFL protein-protein interaction inhibitor which may explain its unique biological properties among αTOL analogs. Moreover, αTOS may act as a CFTR stabilizer, a novel class of drugs that extend cell surface ΔF508-CFTR lifetime.


Cystic Fibrosis , alpha-Tocopherol , Humans , alpha-Tocopherol/pharmacology , Cystic Fibrosis Transmembrane Conductance Regulator/genetics , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Antioxidants/pharmacology , Cystic Fibrosis/drug therapy , Apoptosis
4.
Aging Clin Exp Res ; 34(12): 3097-3105, 2022 Dec.
Article En | MEDLINE | ID: mdl-36181638

PURPOSE: To determine the relationship between family uncertainty and family quality of life (QOL) during the recovery period of patients with cerebrovascular disease in Japan, and the factors that influence family uncertainty. METHODS: Data were collected from copies of patient medical files and interviews with family members of 85 patients admitted to two rehabilitation wards in Japan. Family uncertainty was measured using the Japanese version of the Managing Uncertainty in Illness Scale-Family Member form (MUIS-FM) and family QOL using the World Health Organization Five Well-Being Index (WHO-5). Multiple linear regression analysis was applied to investigate associated factors. RESULTS: WHO-5 score was significantly negatively associated with MUIS-FM score (ß = - 0.236, p = 0.03); other factors associated with MUIS-FM score were the Care Shared Decision-Making Questionnaire for care providers score (ß = - 0.384, p < 0.001), Short Intolerance of Uncertainty Scale score (ß = 0.296, p = 0.001), and history of surgical treatment (ß = 0.199, p = 0.032). CONCLUSIONS: Family QOL could be improved by reducing family uncertainty. It is also suggested that promoting shared decision-making between healthcare providers and patients' families may help reduce family uncertainty. It is necessary to take into account not only family intolerance of uncertainty but also uncertainty that varies by type of acute care provided.


Cerebrovascular Disorders , Quality of Life , Humans , Uncertainty , Japan , Family
5.
Plant Direct ; 6(9): e446, 2022 Sep.
Article En | MEDLINE | ID: mdl-36172078

In Arabidopsis thaliana, the Sigma factor B regulator RsbQ-like family of α/ß hydrolases contains the strigolactone (SL) receptor DWARF14 (AtD14), the karrikin receptor KARRIKIN INSENSITIVE2 (AtKAI2), and DWARF14-LIKE2 (AtDLK2), a protein of unknown function. Despite very similar protein folds, AtD14 and AtKAI2 differ in size and architecture of their ligand binding pockets, influencing their substrate specificity. We present the 1.5 Å crystal structure of AtDLK2, revealing the smallest ligand binding pocket in the protein family, bordered by two unique glycine residues. We identified a gatekeeper residue in the protein's lid domain and present a pyrrolo-quinoline-dione compound that inhibits AtDLK2's enzymatic activity.

6.
J Agric Food Chem ; 70(10): 3109-3116, 2022 Mar 16.
Article En | MEDLINE | ID: mdl-35234040

Melanin is a secondary metabolite required for the infection of the rice blast fungus Pyricularia oryzae. Melanin biosynthesis enzymes are targets for controlling rice blast disease, and three types of commercial melanin biosynthesis inhibitors (MBIs) including MBI-R, MBI-D, and MBI-P have been developed. However, the occurrence of MBI-D-resistant strains containing scytalone dehydratase (SDH1/RSY1) with V75M mutations has been recently reported. In this study, we aimed to identify inhibitors of SDH1-V75M. We screened the RIKEN Natural Products Depository chemical library using chemical array technology and evaluated the inhibition of SDH1-V75M by candidate compounds. NPD13731 strongly inhibited the activity of wild-type and mutant SDH1. The structure-activity relationship data were used to create a more potent inhibitor 16, which controlled rice blast disease in rice plants infected with MBI-D-resistant P. oryzae. Compound 16, which we named melabiostin, may be used to develop fungicides for controlling rice blast infections.


Magnaporthe , Oryza , Ascomycota , Hydro-Lyases/metabolism , Melanins , Oryza/metabolism , Plant Diseases/microbiology
7.
ACS Chem Biol ; 17(2): 483-491, 2022 02 18.
Article En | MEDLINE | ID: mdl-35128925

Glutathione peroxidase 4 (GPX4) is an intracellular enzyme that oxidizes glutathione while reducing lipid peroxides and is a promising target for cancer therapy. To date, several GPX4 inhibitors have been reported to exhibit cytotoxicity against cancer cells. However, some cancer cells are less sensitive to the known GPX4 inhibitors. This study aimed to explore compounds showing synergistic effects with GPX4 inhibitors. We screened a chemical library and identified a compound named NPD4928, whose cytotoxicity was enhanced in the presence of a GPX4 inhibitor. Furthermore, we identified ferroptosis suppressor protein 1 as its target protein. The results indicate that NPD4928 enhanced the sensitivity of various cancer cells to GPX4 inhibitors, suggesting that the combination might have therapeutic potential via the induction of ferroptosis.


Ferroptosis , Glutathione/metabolism , Oxidation-Reduction , Phospholipid Hydroperoxide Glutathione Peroxidase , Small Molecule Libraries/pharmacology
8.
iScience ; 24(12): 103497, 2021 Dec 17.
Article En | MEDLINE | ID: mdl-34934919

The disruption of the tumor microenvironment (TME) is a promising anti-cancer strategy, but its effective targeting for solid tumors remains unknown. Here, we investigated the anti-cancer activity of the mitochondrial complex I inhibitor intervenolin (ITV), which modulates the TME independent of energy depletion. By modulating lactate metabolism, ITV induced the concomitant acidification of the intra- and extracellular environment, which synergistically suppressed S6K1 activity in cancer cells through protein phosphatase-2A-mediated dephosphorylation via G-protein-coupled receptor(s). Other complex I inhibitors including metformin and rotenone were also found to exert the same effect through an energy depletion-independent manner as ITV. In mouse and patient-derived xenograft models, ITV was found to suppress tumor growth and its mode of action was further confirmed. The TME is usually acidic owing to glycolytic cancer cell metabolism, and this condition is more susceptible to complex I inhibitors. Thus, we have demonstrated a potential treatment strategy for solid tumors.

9.
Article En | MEDLINE | ID: mdl-34886431

Digital tools are increasingly used for health promotion, but their utility during recovery from a nuclear disaster has yet to be established. This study analysed differences in knowledge, attitude, and practice (KAP) toward digital tools for radiation protection and health promotion, and preferences for specific application functions, among cohorts living within and outside areas affected by the Fukushima Daiichi nuclear power station (FDNPS) accident. A needs assessment was conducted by internet survey, and responses from those affected (N = 86) and not affected (N = 253) were compared and quantified by an adjusted odds ratio (aOR), using logistic regression analyses. KAP toward the radiation-related application in the affected group had an aOR of 1.95 (95% confidence interval (CI) = 1.12-3.38) for knowledge, and 5.71 (CI = 2.55-12.8) for practice. Conversely, toward the health-related application, the aOR of the affected group was 0.50 (CI = 0.29-0.86). The preference in the affected group was significantly lower for two application functions related to radiation measurement and two health-related functions (one about the effects of radiation in general and another about personal health advice in general): aOR range 0.43-0.50. Development of specific applications incorporating the findings from this survey was intended to foster a locally appropriate eHealth environment during recovery from the FDNPS accident.


Disasters , Fukushima Nuclear Accident , Radiation Protection , Japan , Surveys and Questionnaires
10.
Commun Biol ; 4(1): 1165, 2021 10 07.
Article En | MEDLINE | ID: mdl-34621018

Hypoxia-inducible factor-1 (HIF-1) plays essential roles in human diseases, though its central role in oxygen homoeostasis hinders the development of direct HIF-1-targeted pharmacological approaches. Here, we surveyed small-molecule compounds that efficiently inhibit the transcriptional activity of HIF-1 without affecting body homoeostasis. We focused on Mint3, which activates HIF-1 transcriptional activity in limited types of cells, such as cancer cells and macrophages, by suppressing the factor inhibiting HIF-1 (FIH-1). We identified naphthofluorescein, which inhibited the Mint3-FIH-1 interaction in vitro and suppressed Mint3-dependent HIF-1 activity and glycolysis in cancer cells and macrophages without evidence of cytotoxicity in vitro. In vivo naphthofluorescein administration suppressed tumour growth and metastasis without adverse effects, similar to the genetic depletion of Mint3. Naphthofluorescein attenuated inflammatory cytokine production and endotoxic shock in mice. Thus, Mint3 inhibitors may present a new targeted therapeutic option for cancer and inflammatory diseases by avoiding severe adverse effects.


Adaptor Proteins, Signal Transducing/antagonists & inhibitors , Carcinogenesis/drug effects , Neoplasm Metastasis/drug therapy , Neoplasms/drug therapy , Shock, Septic/drug therapy , Cell Line, Tumor , Fluoresceins/pharmacology , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Mixed Function Oxygenases/genetics , Mixed Function Oxygenases/metabolism , Neoplasm Metastasis/genetics , Neoplasms/genetics , Repressor Proteins/genetics , Repressor Proteins/metabolism
11.
J Biol Chem ; 297(1): 100803, 2021 07.
Article En | MEDLINE | ID: mdl-34022224

The transcriptional coactivator with PDZ-binding motif (TAZ) (WWTR1) induces epithelial-mesenchymal transition and enhances drug resistance in multiple cancers. TAZ has been shown to interact with transcription factors in the nucleus, but when phosphorylated, translocates to the cytoplasm and is degraded through proteasomes. Here, we identified a compound TAZ inhibitor 4 (TI-4) that shifted TAZ localization to the cytoplasm independently of its phosphorylation. We used affinity beads to ascertain a putative target of TI-4, chromosomal segregation 1 like (CSE1L), which is known to be involved in the recycling of importin α and as a biomarker of cancer malignancy. We found that TI-4 suppressed TAZ-mediated transcription in a CSE1L-dependent manner. CSE1L overexpression increased nuclear levels of TAZ, whereas CSE1L silencing delayed its nuclear import. We also found via the in vitro coimmunoprecipitation experiments that TI-4 strengthened the interaction between CSE1L and importin α5 and blocked the binding of importin α5 to TAZ. WWTR1 silencing attenuated CSE1L-promoted colony formation, motility, and invasiveness of human lung cancer and glioblastoma cells. Conversely, CSE1L silencing blocked TAZ-promoted colony formation, motility, and invasiveness in human lung cancer and glioblastoma cells. In human cancer tissues, the expression level of CSE1L was found to correlate with nuclear levels of TAZ. These findings support that CSE1L promotes the nuclear accumulation of TAZ and enhances malignancy in cancer cells.


Cell Nucleus/metabolism , Cellular Apoptosis Susceptibility Protein/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Neoplasms/metabolism , Neoplasms/pathology , Trans-Activators/metabolism , Cell Line, Tumor , Cell Movement , Cell Proliferation , Gene Expression Regulation, Neoplastic , Gene Silencing , Green Fluorescent Proteins/metabolism , Humans , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Models, Biological , Neoplasm Invasiveness , Neoplasms/genetics , Phosphorylation , Photobleaching , Protein Binding , Protein Transport , Subcellular Fractions/metabolism , Transcriptional Coactivator with PDZ-Binding Motif Proteins , Tumor Stem Cell Assay , alpha Karyopherins/metabolism
12.
PeerJ ; 8: e9730, 2020.
Article En | MEDLINE | ID: mdl-32904404

BACKGROUND: Risk communication is widely accepted as a significant factor for policy makers, academic researchers, and practitioners in diverse fields. However, there remains a lack of comprehensive knowledge about how risk communication is currently conducted across fields and about the way risk communication is evaluated. METHODOLOGY: This study systematically searched for materials from three scholarly search engines and one journal with a single search term of "risk communication." The eligibility assessment selected peer-reviewed articles published in English that evaluated risk communication activities. Emphasis was placed on articles published in recent years accounting for about half of the pre-selected ones. Data on field of study, intervention timing, target audience, communication type, and objectives/evaluation indicators was extracted from the articles. Patterns of objectives/evaluation indicators used in risk communication activities were compared with those of the definitions and purposes of risk communication stated by relevant organizations. Association analysis was conducted based on study fields and objectives/evaluation indicators. RESULTS: The screening process yielded 292 articles that were published between 2011 and 2017 in various fields, such as medicine, food safety, chemical substances, and disasters/emergencies. The review process showed that many activities were performed in the medical field, during non-/pre-crisis periods. Recent activities primarily targeted citizens/Non-Profit Organizations (NPOs), and was disseminated in the form of large group or mass communication. While "knowledge increase," "change in risk perception and concern alleviation," and "decision making and behavior change" were commonly addressed in practice, "trust-building" and "reduction in psychological distress" were rarely focused. The analysis also indicated that the medical field tends to perform risk communication at the individual or small group level, in contrast to the food safety field. Further, risk communications in the non-/pre-crisis period are more likely to aim at "changes in risk perception and concern alleviation" than those in the crisis period. Risk communications that aim at "changes in risk perception and concern alleviation" are likely to be presented in a large group or mass communication, whereas those that aim at "decision making and behavior change" are likely to be conducted at the individual or small group level. CONCLUSION: An overview of recent activities may provide those who engage in risk communication with an opportunity to learn from practices in different fields or those conducted in different intervention timings. Devoting greater attention to trust building and reduction in psychological distress and exploring non-citizen/NPO stakeholders' needs would be beneficial across academic and professional disciplines.

13.
Environ Pollut ; 266(Pt 2): 115179, 2020 Nov.
Article En | MEDLINE | ID: mdl-32717636

Hydrophobic pollutants are still present in agricultural soil. The Cucurbitaceae family accumulates hydrophobic pollutants through roots, resulting in the contamination of aerial parts. Major latex-like proteins (MLPs), found in the Cucurbitaceae family, play an important role in the contamination by binding to these hydrophobic pollutants. Thus far, efficient cultivation methods for the production of safe crops with lower concentrations of hydrophobic pollutants have not been developed. Herein, we competitively inhibited the binding of MLPs to hydrophobic pollutants, pyrene and dieldrin, in roots by using MLP binding pesticides. By conducting a chemical array screening, we found that MLPs bound compounds with indole- and quinazoline-like structures. Commercially available pesticides amisulbrom and pyrifluquinazon, which possess such structures, successfully inhibited the binding of MLPs to pyrene and dieldrin in vitro. When zucchini plants were cultivated in the contaminated soil with 1.25 mmol/kg pyrene and 12.5 µmol/kg dieldrin, the concentration of pyrene and dieldrin in xylem sap was significantly decreased by 30% and 15%, respectively. Our results demonstrate that the pesticides binding to MLPs competitively inhibited the binding of MLPs to pyrene and dieldrin in roots, resulting in the reduction of overall contamination. This study proposes a novel approach to cultivate safer crops and advances the utilization of unknown functions of pesticides.


Cucurbita , Environmental Pollutants , Pesticides/analysis , Soil Pollutants/analysis , Binding, Competitive , Latex , Plant Roots/chemistry
14.
Sci Rep ; 10(1): 8691, 2020 05 26.
Article En | MEDLINE | ID: mdl-32457324

Chemical priming is an attractive and promising approach to improve abiotic stress tolerance in a broad variety of plant species. We screened the RIKEN Natural Products Depository (NPDepo) chemical library and identified a novel compound, FSL0260, enhancing salinity-stress tolerance in Arabidopsis thaliana and rice. Through transcriptome analysis using A. thaliana seedlings, treatment of FSL0260 elevated an alternative respiration pathway in mitochondria that modulates accumulation of reactive oxygen species (ROS). From comparison analysis, we realized that the alternative respiration pathway was induced by treatment of known mitochondrial inhibitors. We confirmed that known inhibitors of mitochondrial complex I, such as rotenone and piericidin A, also enhanced salt-stress tolerance in Arabidopsis. We demonstrated that FSL0260 binds to complex I of the mitochondrial electron transport chain and inhibits its activity, suggesting that inhibition of mitochondrial complex I activates an alternative respiration pathway resulting in reduction of ROS accumulation and enhancement of tolerance to salinity in plants. Furthermore, FSL0260 preferentially inhibited plant mitochondrial complex I rather than a mammalian complex, implying that FSL0260 has a potential to be an agent for improving salt-stress tolerance in agriculture that is low toxicity to humans.


Arabidopsis/drug effects , Electron Transport Complex I/metabolism , Salt Tolerance/drug effects , Arabidopsis/growth & development , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Electron Transport Complex I/antagonists & inhibitors , Mitochondria/metabolism , Reactive Oxygen Species/metabolism , Rotenone/pharmacology , Seedlings/drug effects , Seedlings/metabolism , Sodium Chloride/pharmacology
15.
Bio Protoc ; 10(3): e3516, 2020 Feb 05.
Article En | MEDLINE | ID: mdl-33654741

Valosin-containing protein (VCP; also known as p97) is a type II ATPase regulating several cellular processes. Using proteomic techniques, we identified a chemical compound that binds to the D1 ATPase domain of VCP. The protocol described here was to study the effect of the compound on ATPase activity in vitro of purified VCP protein. ATPases are enzymes that hydrolyze ATP in a reaction resulting the release of an inorganic phosphate. This reaction can be measured using several methods, such as colorimetric, fluorescence, and radiometric assays, in addition to the bioluminescence assay mentioned here. Since the remaining ATP level after the reaction was detected using a luciferase assay, the luminescent signal indicates the ATPase activity inversely. This protocol is sensitive, rapid, and can be used for high-throughput screening assays to study the effect of compounds on ATPase function.

16.
Bio Protoc ; 10(3): e3517, 2020 Feb 05.
Article En | MEDLINE | ID: mdl-33654742

Development of methods for protein identification is one of the important aspects of proteomics. Here, we report a protocol for the preparation of compound conjugated beads by photo-crosslinking, affinity purification, gel electrophoresis, and highly sensitive mass spectrometric assay for drug-target identification. Although there are several other methods used for drug-target identification, such as biochemical fractionation or radioactive ligand binding assay, affinity purification is widely used for its straight-forward and easy approach. To identify the target protein of an inhibitor of cancer cell-accelerated fibroblast migration, we prepared the inhibitor-conjugated beads by photo-crosslinking. Proteins were pulled down from cell lysates by the compound beads and separated by SDS-PAGE, and a specifically pulled down protein was cut out, trypsin-digested, analyzed using matrix-assisted laser desorption ionization/time of flight mass spectrometry (MALDI-TOF-MS) and identified by peptide mass fingerprinting (PMF) method. Since the photo-crosslinking enables the immobilization of ligands on an affinity matrix in a functional group-independent manner, we do not have to determine the functional group of the compound to conjugate the matrix. In addition, as compared to other MS techniques such as electrospray ionization, MALDI offers a less complex sample preparation procedure and higher sensitivity, and thus is better suited for the rapid identification of proteins isolated by gel electrophoresis.

17.
ACS Chem Biol ; 14(9): 1964-1971, 2019 09 20.
Article En | MEDLINE | ID: mdl-31497942

The plant hormone abscisic acid (ABA) regulates the development of various plant organs including seeds, roots, and fruits, and significantly contributes to abiotic stress responses, especially to drought. Since recent climate changes are adversely affecting crop cultivation, enhancement of plant stress tolerance by regulation of ABA signaling would be an important strategy. In the plant genome, ABA receptors are encoded by multiple genes constituting three subfamilies; however, functional differences among them remain unclear. To enhance desired effects of ABA, the biological functions of the receptor family warrant clarification. This study aimed to determine the functional differences among ABA receptors in plants. We screened small-molecule ligands binding to specific receptors, using a chemical array. In vitro evaluation of hit compounds using 11 Arabidopsis ABA receptors revealed that (+)-3'-alkyl ABAs served as agonists for different receptors depending on the length of their 3'-alkyl chains. Combinatorial in vitro and physiological effects of these compounds on the stomata, seeds, and seedlings indicated that, along with subfamily III, receptors of subfamily II are important to induce strong drought responses. Among (+)-3'-alkyl ABAs assessed herein, (+)-3'-butyl ABA induced a transcriptional response and stomatal closure but only slightly inhibited seed germination and growth, suggesting that it enhances drought tolerance. In silico docking simulation and site-directed mutagenesis revealed the amino acid residues contributing to the selective agonist activity of the (+)-3'-alkyl ABAs. These results provide novel insights into the structure and biological effects of 3'-derivatives of ABA and a basis for agrochemical development.


Abscisic Acid/analogs & derivatives , Arabidopsis Proteins/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Membrane Transport Proteins/metabolism , Receptors, Cell Surface/metabolism , Abscisic Acid/metabolism , Arabidopsis/chemistry , Arabidopsis/metabolism , Arabidopsis Proteins/agonists , Arabidopsis Proteins/antagonists & inhibitors , Arabidopsis Proteins/genetics , Germination/drug effects , Intracellular Signaling Peptides and Proteins/agonists , Membrane Transport Proteins/agonists , Molecular Docking Simulation , Molecular Structure , Mutagenesis, Site-Directed , Mutation , Phosphoprotein Phosphatases/antagonists & inhibitors , Plant Leaves/metabolism , Protein Binding , RNA, Messenger/metabolism , Receptors, Cell Surface/agonists , Receptors, Cell Surface/genetics , Structure-Activity Relationship
18.
ACS Chem Biol ; 14(8): 1819-1828, 2019 08 16.
Article En | MEDLINE | ID: mdl-31365229

Thioviridamide, prethioviridamide, and JBIR-140, which are ribosomally synthesized and post-translationally modified peptides (RiPPs) possessing five thioamide bonds, induce selective apoptosis in various cancer cells, especially those expressing the adenovirus oncogene E1A. However, the target protein of this unique family of bioactive compounds was previously unknown. To investigate the mechanism of action, we adopted a combined approach of genome-wide shRNA library screening, transcriptome profiling, and biochemical identification of prethioviridamide-binding proteins. An shRNA screen identified 63 genes involved in cell sensitivity to prethioviridamide, which included translation initiation factors, aminoacyl tRNA synthetases, and mitochondrial proteins. Transcriptome profiling and subsequent analysis revealed that prethioviridamide induces the integrated stress response (ISR) through the GCN2-ATF4 pathway, which is likely to cause cell death. Furthermore, we found that prethioviridamide binds and inhibits respiratory chain complex V (F1Fo-ATP synthase) in mitochondria, suggesting that inhibition of complex V leads to activation of the GCN2-ATF4 pathway. These results imply that the members of a unique family of RiPPs with polythioamide structure target mitochondria to induce the ISR.


Antineoplastic Agents/pharmacology , Oligopeptides/pharmacology , Thioamides/pharmacology , Activating Transcription Factor 4/metabolism , Animals , Antineoplastic Agents/chemistry , Gene Expression Profiling , HeLa Cells , Humans , Mitochondria/metabolism , Oligopeptides/chemistry , Protein Kinases/metabolism , Protein Processing, Post-Translational , Proton-Translocating ATPases/antagonists & inhibitors , RNA/metabolism , Rats , Signal Transduction/physiology , Thioamides/chemistry
19.
Bioconjug Chem ; 30(5): 1395-1404, 2019 05 15.
Article En | MEDLINE | ID: mdl-30888797

The X-linked inhibitor of apoptosis protein baculovirus IAP repeat (XIAP BIR3) domain is a promising therapeutic target for cancer treatment. For the mirror-image screening campaign to identify drug candidates from an unexplored mirror-image natural product library, a facile synthetic protocol for XIAP BIR3 domain synthesis was established by a native chemical ligation strategy using conserved cysteines present among BIR domains. The native and mirror-image XIAP BIR3 domains with an appropriate functional group for labeling were prepared using the established protocol. Taking advantage of the resulting synthetic proteins, several bioassay systems were developed to characterize inhibitors of the protein-protein interaction between the XIAP BIR3 domain and the second mitochondria-derived activator of caspases.


X-Linked Inhibitor of Apoptosis Protein/antagonists & inhibitors , Amino Acid Sequence , Biological Assay , Humans , Protein Binding , Protein Conformation , Protein Domains , Protein Folding , Sequence Homology, Amino Acid , X-Linked Inhibitor of Apoptosis Protein/chemistry , X-Linked Inhibitor of Apoptosis Protein/metabolism
20.
J Biol Chem ; 294(9): 2988-2996, 2019 03 01.
Article En | MEDLINE | ID: mdl-30610116

Carcinoma-associated fibroblasts are fibroblasts activated by surrounding cancer cells. Carcinoma-associated fibroblasts exhibit enhanced cell migration, which plays an important role in cancer metastasis. Previously, we demonstrated enhanced migration of NIH3T3 fibroblasts when they were cultured in the presence of MCF7 breast cancer cells. Human fibroblasts displayed a similar phenomenon even when they were co-cultured with cancer cells other than MCF7 cells. In this study, we screened ∼16,000 compounds from the RIKEN Natural Products Depository chemical library for inhibitors of enhanced NIH3T3 cell migration in the presence of MCF7. We identified NPD8733 as an inhibitor of cancer cell-enhanced fibroblast migration. This inhibition was observed not only in a wound-healing co-culture assay but also in a Transwell migration assay. Using NPD8733 and a structurally similar but inactive derivative, NPD8126, on immobilized beads, we found that NPD8733, but not NPD8126, specifically binds to valosin-containing protein (VCP)/p97, a member of the ATPase-associated with diverse cellular activities (AAA+) protein family. Using VCP truncation variants, we found that NPD8733 binds to the D1 domain of VCP. Because VCP's D1 domain is important for its function, we concluded that NPD8733 may act on VCP by binding to this domain. siRNA-mediated silencing of VCP in NIH3T3 fibroblasts, but not in MCF7 cells, reduced the migration of the co-cultured NIH3T3 fibroblasts. These results indicate that MCF7 activates the migration of NIH3T3 cells through VCP and that NPD8733 binds VCP and thereby inhibits its activity.


Cell Movement/drug effects , Fibroblasts/cytology , Fibroblasts/drug effects , Small Molecule Libraries/metabolism , Small Molecule Libraries/pharmacology , Valosin Containing Protein/metabolism , Animals , Coculture Techniques , Drug Evaluation, Preclinical , Humans , Ligands , MCF-7 Cells , Mice , NIH 3T3 Cells , Protein Domains , Valosin Containing Protein/chemistry
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