Use of immune checkpoint inhibitors (ICIs) as cancer immunotherapy has advanced rapidly in the clinic; however, ICI initiation can also cause an unexpectedly rapid acceleration of cancer progression in some patients. Here, we used a murine syngeneic melanoma model to conduct mechanistic analysis of cancer-associated fibroblast (CAF) function in cancer progression in the context of immunotherapy. We found that after ICI treatment CAFs acquire inflammatory properties, which can promote tumor progression.
View Article and Find Full Text PDFExtracellular membrane vesicles (MVs) caused by the artificial production of polyhydroxybutyrate (PHB) were previously detected in Escherichia coli. We herein observed MV biogenesis in the mutant strain (-PHB) of the natural PHB producer, Cupriavidus necator H16. This inverse relationship was revealed through comparative electron microscopic ana-lyses of wild-type and mutant strains.
View Article and Find Full Text PDFThe Diels-Alder (DA) reaction, specifically referring to the [4 + 2] cycloaddition reaction in pericyclic reactions, is a process that forms two carbon-carbon covalent bonds in a single step via an electron ring transition state. Among the secondary metabolites produced by microorganisms, numerous compounds are biosynthesized through DA reactions, most of which are enzymatic. Our research group has discovered an enzyme named Diels-Alderase (DAase) that catalyzes the DA reaction in filamentous fungi, and we have been investigating its catalytic mechanism.
View Article and Find Full Text PDFA microaerophilic Gram-stain-negative bacilliform bacterial strain, FB-5, was isolated from activated sludge in Yokohama, Japan, that exhibited filamentous growth and formed a microtube (sheath). Cells were motile using a single polar flagellum. The optimum growth temperature and pH were 30 °C and 7.
View Article and Find Full Text PDFNatural products are important sources of seed compounds for drug discovery. However, it has become difficult in recent years to discover new compounds with valuable pharmacological activities. On the other hand, among the vast number of natural products that have been isolated so far, a considerable number of compounds with specific biological activities are thought to be overlooked in screening that uses biological activity as an index.
View Article and Find Full Text PDFUse of immune checkpoint inhibitors (ICIs) as cancer immunotherapy has advanced rapidly in the clinic. We recently reported that tumor stroma-derived angiopoietin-like protein 2 (ANGPTL2) has tumor suppressive activity by enhancing dendritic cell-mediated CD8 T cell anti-tumor immune responses. However, a direct impact of ANGPTL2 on ICI anti-tumor effect remains unclear.
View Article and Find Full Text PDF(-)-FR901483 () isolated from the fungus sp. No.11231 achieves immunosuppression via nucleic acid biosynthesis inhibition rather than IL-2 production inhibition as accomplished by FK506 and cyclosporin A.
View Article and Find Full Text PDFPreviously, we reported that an ANGPTL3 vaccine is a hopeful therapeutic option against dyslipidemia. In our current study, we assess durability and booster effects of that vaccine over a period representing a mouse's lifespan. The vaccine remained effective for over one year, and booster vaccination maintained suppression of circulating triglyceride levels thereafter without major adverse effects on lungs, kidneys, or liver, suggesting vaccine efficacy and safety.
View Article and Find Full Text PDFThe lactate-based polyester poly[lactate (LA)--3-hydroxybutyrate (3HB)], termed LAHB, is a highly transparent and flexible bio-based polymeric material. There are many unknowns regarding its degradation process in riverine environments, especially the changes in bacterial flora that might result from its degradation and the identities of any LAHB-degrading bacteria. LAHB were immersed in the river water samples (A and B), and LAHB degradation was observed in terms of the weight change of the polymer and the microscopic changes on the polymer surfaces.
View Article and Find Full Text PDFUse of immune checkpoint inhibitors (ICIs) as cancer immunotherapy advances rapidly in the clinic. Despite their therapeutic benefits, ICIs can cause clinically significant immune-related adverse events (irAEs), including myocarditis. However, the cellular and molecular mechanisms regulating irAE remain unclear.
View Article and Find Full Text PDFWe report biosynthetic pathways that can synthesize and transform conjugated octaenes and nonaenes to complex natural products. The biosynthesis of (-)-PF1018 involves an enzyme PfB that can control the regio-, stereo-, and periselectivity of multiple reactions starting from a conjugated octaene. Using PfB as a lead, we discovered a homologous enzyme, BruB, that facilitates diene isomerization, tandem 8π-6π-electrocyclization, and a 1,2-divinylcyclobutane Cope rearrangement to generate a new-to-nature compound.
View Article and Find Full Text PDFThe increased incidence of obesity in the global population has increased the risk of several chronic inflammation-related diseases, including non-alcoholic steatohepatitis (NASH)-hepatocellular carcinoma (HCC). The progression from NASH to HCC involves a virus-independent liver carcinogenic mechanism; however, we currently lack effective treatment and prevention strategies. Several reports have suggested that fecal volatile organic compounds (VOCs) are strongly associated with NASH-HCC; therefore, we explored the biomarkers involved in its pathogenesis and progression.
View Article and Find Full Text PDFBackground: The ability to predict secondary cardiovascular events could improve health of patients undergoing statin treatment. Circulating ANGPTL8 (angiopoietin-like protein 8) levels, which positively correlate with proatherosclerotic lipid profiles, activate the pivotal proatherosclerotic factor ANGPTL3. Here, we assessed potential association between circulating ANGPTL8 levels and risk of secondary cardiovascular events in statin-treated patients.
View Article and Find Full Text PDFBackground: Colibactin is a genotoxin produced by Escherichia coli and other Enterobacteriaceae that is believed to increase the risk of colorectal cancer (CRC) of their symbiosis hosts, including human. A peptidase ClbP is the key enzyme for activation of colibactin. Inhibition of ClbP is considered to impede maturation of precolibactin into genotoxic colibactin.
View Article and Find Full Text PDFDiosgenin is an aglycone of dioscin, a major bioactive steroidal saponin found in plants, including Himalayan Paris (), fenugreek (), and yam ( spp.). We have previously demonstrated that a species of natural yam, , contains a promising bioactive compound diosgenin, which induces anti-carcinogenic and anti-hypertriacylglycerolemic activities.
View Article and Find Full Text PDFBackground: Evaluating patients' risk for acute kidney injury (AKI) is crucial for positive outcomes following cardiac surgery. Our aims were first to select candidate risk factors from pre- or intra-operative real-world parameters collected from routine medical care and then evaluate potential associations between those parameters and risk of onset of post-operative cardiac surgery-associated AKI (CSA-AKI).
Method: We conducted two cohort studies in Japan.
Uncontrolled proliferation of intestinal epithelial cells caused by mutations in genes of the WNT/β-catenin pathway is associated with development of intestinal cancers. We previously reported that intestinal stromal cell-derived angiopoietin-like protein 2 (ANGPTL2) controls epithelial regeneration and intestinal immune responses. However, the role of tumor cell-derived ANGPTL2 in intestinal tumorigenesis remained unclear.
View Article and Find Full Text PDFRecent studies have shown that often carries a biosynthetic gene cluster termed either the island or the cluster that allows the production of a genotoxic polyketide-nonribosomal peptide hybrid secondary metabolite called colibactin. While the gene cluster is not always expressed, when the strain that resides in the colon produces the genotoxin, it is suspected to become a risk factor for colorectal cancer. Therefore, there is great interest in devising a simple method for the detection of colibactin-producing strains and understanding the detailed mechanism of how colibactin can induce oncogenesis, to develop convenient early screening methods and possible preventive treatments against colorectal cancer.
View Article and Find Full Text PDFPurpose: After our group described the first remote-access thyroidectomy series in 2000, the procedure has been further developed. Although a thoracoscopic approach with a conventional open cervical incision for thyroid goiters with mediastinal extension has been performed at many institutions, remote-access thyroidectomy for cervicomediastinal goiters has not been established. We have performed combined thoracoscopic and axillary subcutaneous endoscopic thyroidectomies (axillo-thoracic endoscopic thyroidectomies).
View Article and Find Full Text PDFThe Diels-Alder (DA) reaction refers to a [4 + 2] cycloaddition reaction that falls under the category of pericyclic reactions. It is a reaction that allows regio- and stereo-selective construction of two carbon-carbon bonds simultaneously in a concerted manner to generate a six-membered ring structure through a six-electron cyclic transition state. The DA reaction is one of the most widely applied reactions in organic synthesis, yet its role in biological systems has been debated intensely over the last four decades.
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