RESUMEN
Pyroglutamate (pE)-modified amyloid-ß (Aß) peptides play a crucial role in the development of Alzheimer's disease. pEAß3-42 can rapidly form oligomers that gradually elongate hydrophobic segments to form ß-sheet-rich amyloid intermediates, ultimately resulting in the formation of mature amyloid fibrils. pEAß3-42 can also catalyze the aggregation of Aß species and subsequently accelerate the formation of amyloid senile plaques. Considering the recent clinical success of the pEAß3-42-targeting antibody donanemab, molecules that strongly bind pEAß3-42 and prevent its aggregation and catalytic effect on Aßs may also provide potential therapeutic options for Alzheimer's disease. Here, we demonstrate that the natural antibiotic cyclopeptide tyrocidine A (TA) not only strongly inhibits the aggregation of Aß1-42 as previously reported, but also interacts with the hydrophobic C-terminus and middle domain of pEAß3-42 to maintain an unordered conformation, effectively impeding the formation of initial oligomers and subsequently halting the aggregation of pEAß3-42. Furthermore, TA can disrupt the "catalytic effect" of pEAß3-42 on amyloid aggregates, effectively suppressing Aß aggregation and ultimately preventing the pathological events induced by Aßs.
Asunto(s)
Péptidos beta-Amiloides , Interacciones Hidrofóbicas e Hidrofílicas , Ácido Pirrolidona Carboxílico , Péptidos beta-Amiloides/metabolismo , Péptidos beta-Amiloides/química , Ácido Pirrolidona Carboxílico/química , Ácido Pirrolidona Carboxílico/análogos & derivados , Ácido Pirrolidona Carboxílico/farmacología , Humanos , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Agregado de Proteínas/efectos de los fármacos , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacología , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/tratamiento farmacológicoRESUMEN
Cyclic GMP-AMP synthase (cGAS) is an essential sensor of aberrant cytosolic DNA for initiating innate immunity upon invading pathogens and cellular stress, which is considered as a potential drug target for autoimmune and autoinflammatory diseases. Here, we report the discovery of a class of cyclopeptide inhibitors of cGAS identified by an in vitro screening assay from a focused library of cyclic peptides. These cyclopeptides specifically bind to the DNA binding site of cGAS and block the binding of dsDNA with cGAS, subsequently inhibit dsDNA-induced liquid phase condensation and activation of cGAS. The specificity and potency of one optimal lead XQ2B were characterized in cellular assays. Concordantly, XQ2B inhibited herpes simplex virus-1 (HSV-1)-induced antiviral immune responses and enhanced HSV-1 infection in vitro and in vivo. Furthermore, XQ2B significantly suppressed the elevated levels of type I interferon and proinflammatory cytokines in primary macrophages from Trex1-/- mice and systemic inflammation in Trex1-/- mice. XQ2B represents the specific cGAS inhibitor targeting protein-DNA interaction and phase separation and serves as a scaffold for the development of therapies in the treatment of cGAS-dependent inflammatory diseases.
Asunto(s)
ADN , Péptidos Cíclicos , Animales , Ratones , Péptidos Cíclicos/farmacología , ADN/metabolismo , Nucleotidiltransferasas/metabolismo , Inmunidad Innata , CitocinasRESUMEN
Bioluminogenic probes emerged as powerful tools for imaging and analysis of various bioanalyses, but traditional approaches would be limited to the low sensitivity during determine the low activity of protease in clinical specimens. Herein, we proposed a caged luciferase inhibitor-based bioluminescence-switching strategy (CLIBS) by using a cleavable luciferase inhibitor to modulate the activity of luciferase reporter to amplify the detective signals, which led to the enhancement of detection sensitivity, and enabled the determination of circulating Aminopeptidase N (APN) activity in thousands of times diluted serum. By applying the CLIBS to serum samples in non-small cell lung cancer (NSCLC) patients from two clinical cohorts, we revealed that, for the first time, higher circulating APN activities but not its concentration, were associated with more NSCLC metastasis or higher metastasis stages by subsequent clinical analysis, and can serve as an independent factor for forecasting NSCLC patients' risk of metastasis.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Antígenos CD13 , LuciferasasRESUMEN
PURPOSE: The adaptive immune responses induced by radiotherapy has been demonstrated to largely rely on STING-dependent type I interferons (IFNs) production. However, irradiated tumor cells often fail to induce dendritic cells (DCs) to produce type I IFNs. Hence, we aim to uncover the limitation of STING-mediated innate immune sensing following radiation, and identify efficient reagents capable to rescue the failure of type I IFNs induction for facilitating radiotherapy. METHODS: A targeted cell-based phenotypic screening was performed to search for active molecules that could elevate the production of type I IFNs. USP14 knockout or inhibition was assayed for IFN production and the activation of STING signaling in vitro. The mechanisms of USP14 were investigated by western blot and co-immunoprecipitation in vitro. Additionally, combinational treatments with PT33 and radiation in vivo and in vitro models were performed to evaluate type I IFNs responses to radiation. RESULTS: PT33 was identified as an enhancer of STING agonist elicited type I IFNs production to generate an elevated and durable STING activation profile in vitro. Mechanistically, USP14 inhibition or deletion impairs the deubiquitylation of K63-linked IRF3. Furthermore, blockade of USP14 with PT33 enhances DC sensing of irradiated-tumor cells in vitro, and synergizes with radiation to promote systemic antitumor immunity in vivo. CONCLUSION: Our findings reveal that USP14 is one of the major IFN production suppressors and impairs the activation of IRF3 by removing the K63-linked ubiquitination of IRF3. Therefore, blockage of USP14 results in the gain of STING signaling activation and radiation-induced adaptive immune responses.
Asunto(s)
Inmunidad Adaptativa , Interferón Tipo I , Interferón beta , Radioterapia , Ubiquitina Tiolesterasa , Humanos , Inmunidad Innata , Factor 3 Regulador del Interferón , Interferón Tipo I/metabolismo , Interferón beta/metabolismo , Proteínas de la Membrana/metabolismo , Transducción de Señal , Células Tumorales CultivadasRESUMEN
The extensive applications of Firefly luciferase (Fluc) in numerous biological, biomedical, and clinical investigations rendered an urgent need for efficient and biocompatible Fluc inhibitors for the construction of novel assay platforms. Herein we describe the identification of 2-benzylidene-tetralone derivatives as highly potent and reversible Firefly luciferase inhibitors by competing with d-luciferin. The most active compound 48 was found to have >7000 fold higher potency (IC50 = 0.25 nM) than that of the well-known luciferase inhibitor resveratrol (IC50 = 1.9 µM) biochemically with sub- to low nanomolar IC50 values, and it can efficiently block the Fluc generated bioluminescence in vivo.
RESUMEN
The first proteolysis targeting chimeras for the intracellular elimination of transforming growth factor-ß1 (TGF-ß1), which contributes to various diseases, are described. The appropriately designed DT-6 could efficiently degrade intracellular TGF-ß1, and inhibit M2 macrophage induced epithelial to mesenchymal transition and invasive migration of cancer cells.
Asunto(s)
Péptidos y Proteínas de Señalización Intercelular/metabolismo , Macrófagos/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Transición Epitelial-Mesenquimal , Células Hep G2 , Humanos , Invasividad NeoplásicaRESUMEN
Raloxifene, a selective estrogen receptor modulator, displays benefits for Alzheimer's disease (AD) prevention in postmenopausal women as hormonal changes during menopause have the potential to influence AD pathogenesis, but the underlying mechanism of its neuroprotection is not entirely clear. In this study, the effects of raloxifene on amyloid-ß (Aß) amyloidogenesis were evaluated. The results demonstrated that raloxifene inhibits Aß42 aggregation and destabilizes preformed Aß42 fibrils through directly interacting with the N-terminus and middle domains of Aß42 peptides. Consequently, raloxifene not only reduces direct toxicity of Aß42 in HT22 neuronal cells, but also suppresses expressions of tumor necrosis factor-α and transforming growth factor-ß induced by Aß42 peptides, and then alleviates microglia-mediated indirect toxicity of Aß42 to HT22 neuronal cells. Our results suggested an alternative possible explanation for the neuroprotective activity of raloxifene in AD prevention.
Asunto(s)
Péptidos beta-Amiloides/toxicidad , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Fragmentos de Péptidos/toxicidad , Agregado de Proteínas/efectos de los fármacos , Clorhidrato de Raloxifeno/farmacología , Enfermedad de Alzheimer/prevención & control , Péptidos beta-Amiloides/química , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Interacciones Hidrofóbicas e Hidrofílicas , Ratones , Microglía/citología , Microglía/metabolismo , Neuronas/metabolismo , Fármacos Neuroprotectores/química , Fragmentos de Péptidos/química , Agregación Patológica de Proteínas/metabolismo , Dominios Proteicos , Clorhidrato de Raloxifeno/química , Factor de Crecimiento Transformador beta/genética , Factor de Necrosis Tumoral alfa/genéticaRESUMEN
The intrinsic haemolysis of an amyloid-ß (Aß) N-terminal targeting gramicidin S derivative was successfully dissociated from its Aß oligomer-preventing activities via Ala-scanning-based regulation of molecular amphiphilicity. The representative analogue DGR-7 shows low toxicity but significant efficiency in preventing Aß oligomers and reducing amyloid plaques in APP/PS1 transgenic AD mice.
Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/metabolismo , Gramicidina/farmacología , Hemólisis/efectos de los fármacos , Placa Amiloide/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Animales , Relación Dosis-Respuesta a Droga , Gramicidina/efectos adversos , Gramicidina/química , Ratones , Ratones Transgénicos , Conformación Molecular/efectos de los fármacos , Células PC12 , Placa Amiloide/metabolismo , RatasRESUMEN
Major limitations of chalcones as clinical anticancer agents are water insolubility and poor bioavailability, which may be improved by a classic phosphate prodrug strategy that targets non-specific alkaline phosphatase (ALP) for releasing the parent drug in vivo. In this study, we found that BOC26P, a phosphate prodrug of chalcone OC26, exhibits excellent water solubility and improved plasma concentration in vivo by either i.v. or p.o. compared with the parent drug. In pace with decreased inhibitory activity of BOC26P against microtubule polymerization in vitro and in cells, the antiproliferative activity of BOC26P is attenuated in A549 and HLF cells. However, the antitumor effect of BOC26P increases in an A549 xenograft model as compared to the equimolar concentration of OC26, suggesting that complex tumor microenvironment would be another important influence factor to regulate the antitumor activity of BOC26Pin vivo. In conclusion, these observations showed that the traditional phosphate prodrug strategy would be a promising and easy method to increase water solubility and anticancer activity of chalcones for the clinical developments of anticancer agents.
Asunto(s)
Antineoplásicos/síntesis química , Chalconas/síntesis química , Fosfatos/síntesis química , Profármacos/síntesis química , Células A549 , Animales , Antineoplásicos/farmacología , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Chalconas/farmacología , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos/métodos , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Fosfatos/farmacología , Profármacos/farmacología , Ratas , Ratas Sprague-Dawley , Solubilidad , Agua/química , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
Elimination of amyloid-ß (Aß) oligomers remains challenging. We describe here a novel strategy to prevent and eliminate the Aß oligomers from either the early aggregation or the fibril dissolution pathway by targeting the flexible N-terminus, but not the widely investigated hydrophobic segment, with a rationally designed cyclopeptide.
Asunto(s)
Péptidos beta-Amiloides/química , Gramicidina/química , Gramicidina/síntesis química , Interacciones Hidrofóbicas e Hidrofílicas , Conformación MolecularRESUMEN
The proteasomal 19S regulatory particle (RP) associated deubiquitinases (DUBs) have attracted much attention owing to their potential as a therapeutic target for cancer therapy. Identification of new entities against 19S RP associated DUBs and illustration of the underlying mechanisms is crucial for discovery of novel proteasome blockers. In this study, a series of 4-arylidene curcumin analogues were identified as potent proteasome inhibitor by preferentially blocking deubiquitinase function of proteasomal 19S RP with moderate 20S CP inhibition. The most active compound 33 exhibited a major inhibitory effect on 19S RP-associated ubiquitin-specific proteases 14, along with a minor effect on ubiquitin C-terminal hydrolase 5, which resulted in dysfunction of proteasome, and subsequently accumulated ubiquitinated proteins (such as IκB) in several cancer cells. Remarkably, though both 19S RP and 20S CP inhibition induced significantly endoplasmic reticulum stress and triggered caspase-12/9 pathway activation to promote cancer cell apoptosis, the 19S RP inhibition by 33 avoided slow onset time, Bcl-2 overexpression, and PERK-phosphorylation, which contribute to the deficiencies of clinical drug Bortezomib. These systematic studies provided insights in the development of novel proteasome inhibitors for cancer treatment.
Asunto(s)
Antineoplásicos/farmacología , Curcumina/análogos & derivados , Curcumina/farmacología , Enzimas Desubicuitinizantes/antagonistas & inhibidores , Complejo de la Endopetidasa Proteasomal , Inhibidores de Proteasoma/farmacología , Células A549 , Animales , Antineoplásicos/química , Células CHO , Proliferación Celular/efectos de los fármacos , Proliferación Celular/fisiología , Cricetinae , Cricetulus , Enzimas Desubicuitinizantes/metabolismo , Relación Dosis-Respuesta a Droga , Sistemas de Liberación de Medicamentos/métodos , Humanos , Complejo de la Endopetidasa Proteasomal/metabolismo , Inhibidores de Proteasoma/químicaRESUMEN
Amyloid-ß (Aß) oligomers are causative agents triggering AD pathogenesis, but their elimination remains challenging. We herein reported a natural cyclopeptide tyrocidine A prevents and reverses amyloidogenesis without Aß oligomer accumulation by stabilizing the monomeric, but not the oligomeric state of Aß peptides.