Relationship of plasma 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid concentration with OATP1B activity in patients with chronic kidney disease.

Organic anion-transporting polypeptides (OATP)1B are drug transporters mainly expressed in the sinusoidal membrane. Many studies have suggested that OATP1B activity is affected by genetic factor, the uremic toxin 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF), and inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Coproporphyrin-I (CP-I) is spotlighted as a highly accurate endogenous substrate of OATP1B. We previously reported a positive correlation between plasma CMPF and CP-I concentrations in patients with chronic kidney disease (CKD). The present study evaluated the impact of genetic polymorphisms, CMPF, IL-6, TNF-α, and estimated glomerular filtration rate (eGFR) on individual differences in OATP1B activity in patients with CKD. Seventy-three patients with CKD who received kidney transplant at least 3 months earlier were analyzed. Plasma CP-I concentration was higher in OATP1B1*15 carriers than in non-carriers. In all patients, CP-I did not correlate significantly with CMPF, IL-6, TNF-α, or eGFR. However, when the dataset was cut off at CMPF concentration of 8 and 7 µg/mL, 4 µg/mL, 3 µg/mL or 2 µg/mL, CMPF correlated positively with CP-I, and correlation coefficient tended to be higher as plasma CMPF concentration was lower. In conclusion, OATP1B1*15 impacted OATP1B activity in patients with CKD, but IL-6 and TNF-α did not. However, the impact of CMPF on OATP1B activity was limited to low CMPF concentrations, and the effect could be saturated at high concentrations. When prescribing an OATP1B substrate drug for patients with CKD, the OATP1B1*15 carrier status and plasma CMPF concentration may need to be considered to decide the dose regimen.

Non-cytotoxic nanomolar concentration of arctigenin protects neuronal cells from chemotherapy-induced ferroptosis by regulating SLC7A11-cystine-cysteine axis.

Neurotoxicity is a common side effect of certain types of therapeutic drugs, posing a major hurdle for their clinical application. Accumulating evidence suggests that ferroptosis is involved in the neurotoxicity induced by these drugs. Therefore, targeting ferroptosis is considered to be a reasonable approach to prevent such side effect. Arctigenin (ATG) is a major bioactive ingredient of Arctium lappa L., a popular medicinal plant in Asia, and has been reported to have multiple bioactivities including neuroprotection. However, the mechanisms underlying the neuroprotection of ATG has not been well elucidated. The purpose of this study was to investigate whether the neuroprotection of ATG was associated with its ability to protect neuronal cells from ferroptosis. Using neuronal cell ferroptosis model induced by either classic ferroptosis induces or therapeutic drugs, we demonstrated for the first time that ATG in the nanomolar concentration range effectively prevented neuronal cell ferroptosis induced by classic ferroptosis inducer sulfasalazine (SAS) and erastin (Era), or therapeutic drug oxaliplatin (OXA) and 5-fluorouracil (5-FU). Mechanistically, we uncovered that the anti-ferroptotic effect of ATG was attributed to its ability to activate SLC7A11-cystine-cysteine axis. The findings of the present study implicate that ATG holds great potential to be developed as a novel agent for preventing SLC7A11 inhibition-mediated neurotoxicity.

Pharmacological induction of chromatin remodeling drives chemosensitization in triple-negative breast cancer.

Targeted therapies have improved outcomes for certain cancer subtypes, but cytotoxic chemotherapy remains a mainstay for triple-negative breast cancer (TNBC). The epithelial-to-mesenchymal transition (EMT) is a developmental program co-opted by cancer cells that promotes metastasis and chemoresistance. There are no therapeutic strategies specifically targeting mesenchymal-like cancer cells. We report that the US Food and Drug Administration (FDA)-approved chemotherapeutic eribulin induces ZEB1-SWI/SNF-directed chromatin remodeling to reverse EMT that curtails the metastatic propensity of TNBC preclinical models. Eribulin induces mesenchymal-to-epithelial transition (MET) in primary TNBC in patients, but conventional chemotherapy does not. In the treatment-naive setting, but not after acquired resistance to other agents, eribulin sensitizes TNBC cells to subsequent treatment with other chemotherapeutics. These findings provide an epigenetic mechanism of action of eribulin, supporting its use early in the disease process for MET induction to prevent metastatic progression and chemoresistance. These findings warrant prospective clinical evaluation of the chemosensitizing effects of eribulin in the treatment-naive setting.

Synthesis and antiproliferative activity of a tetrahydrofuran analog of FR901464.

FR901464 is a natural product that exhibits antiproliferative activity at single-digit nanomolar concentrations in cancer cells. Its tetrahydropyran-spiroepoxide covalently binds the spliceosome. Through our medicinal chemistry campaign, we serendipitously discovered that a bromoetherification formed a tetrahydrofuran. The tetrahydrofuran analog was three orders of magnitude less potent than the corresponding tetrahydropyran analogs. This study shows the significance of the tetrahydropyran ring that presents the epoxide toward the spliceosome.

Dihydrotanshinone I exhibits antitumor effects via ß-catenin downregulation in papillary thyroid cancer cell lines.

Thyroid cancer is the most common endocrine carcinoma and, among its different subtypes, the papillary subtype (PTC) is the most frequent. Generally, PTCs are well differentiated, but a minor percentage of PTCs are characterized by a worse prognosis and more aggressive behavior. Phytochemicals, naturally found in plant products, represent a heterogeneous group of bioactive compounds that can interfere with cell proliferation and the regulation of the cell cycle, taking part in multiple signaling pathways that are often disrupted in tumor initiation, proliferation, and progression. In this work, we focused on 15,16-dihydrotanshinone I (DHT), a tanshinone isolated from Salvia miltiorrhiza Bunge (Danshen). We first evaluated DHT biological effect on PTC cells regarding cell viability, colony formation ability, and migration capacity. All of these parameters were downregulated by DHT treatment. We then investigated gene expression changes after DHT treatment by performing RNA-seq. The analysis revealed that DHT significantly reduced the Wnt signaling pathway, which plays a role in various diseases, including cancer. Finally, we demonstrate that DHT treatment decreases protein levels of ß-catenin, a final effector of canonical Wnt signaling pathway. Overall, our data suggest a possible use of this nutraceutical as an adjuvant in the treatment of aggressive papillary thyroid carcinoma.

Formation, Identification, and Occurrence of the Furan-Containing ß-Carboline Flazin Derived from l-Tryptophan and Carbohydrates.

ß-Carbolines (ßCs) are bioactive indole alkaloids found in foods and in vivo. This work describes the identification, formation, and occurrence in foods of the ßC with a furan moiety flazin (1-[5-(hydroxymethyl)furan-2-yl]-9H-pyrido[3,4-b]indole-3-carboxylic acid). Flazin was formed by the reaction of l-tryptophan with 3-deoxyglucosone but not with 5-hydroxymethylfurfural. Its formation was favored in acidic conditions and heating (70-110 °C). The proposed mechanism of formation occurs through the formation of intermediates 3,4-dihydro-ß-carboline-3-carboxylic acid (imines), followed by the oxidation to C═O in the carbohydrate chain and aromatization to ßC ring with subsequent dehydration steps and cyclization to afford the furan moiety. Flazin is generated in the reactions of tryptophan with carbohydrates. Its formation from fructose was higher than from glucose, whereas sucrose gave flazin under acidic conditions and heating owing to hydrolysis. Flazin was identified in foods by HPLC-MS, and its content was determined by HPLC-fluorescence. It occurred in numerous processed foods, such as tomato products, including crushed tomato puree, fried tomato, ketchup, tomato juices, and jams, but also in soy sauce, beer, balsamic vinegar, fruit juices, dried fruits, fried onions, and honey. Their concentrations ranged from not detected to 22.3 µg/mL, with the highest mean levels found in tomato concentrate (13.9 µg/g) and soy sauce (9.4 µg/mL). Flazin was formed during the heating process, as shown in fresh tomato juice and crushed tomatoes. These results indicate that flazin is widely present in foods and is daily uptaken in the diet.

Utilising Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to track the oxidation of lignin by an alkaliphilic laccase.

Lignin is a complex heteroaromatic polymer which is one of the most abundant and diverse biopolymers on the planet. It comprises approximately one third of all woody plant matter, making it an attractive candidate as an alternative, renewable feedstock to petrochemicals to produce fine chemicals. However, the inherent complexity of lignin makes it difficult to analyse and characterise using common analytical techniques, proving a hindrance to the utilisation of lignin as a green chemical feedstock. Herein we outline the tracking of lignin degradation by an alkaliphilic laccase in a semi-quantitative manner using a combined chemical analysis approach using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) to characterise shifts in chemical diversity and relative abundance of ions, and NMR to highlight changes in the structure of lignin. Specifically, an alkaliphilic laccase was used to degrade an industrially relevant lignin, with compounds such as syringaresinol being almost wholly removed (95%) after 24 hours of treatment. Structural analyses reinforced these findings, indicating a >50% loss of NMR signal relating to ß-ß linkages, of which syringaresinol is representative. Ultimately, this work underlines a combined analytical approach that can be used to gain a broader semi-quantitative understanding of the enzymatic activity of laccases within a complex, non-model mixture.

Drug Repurposing of ACT001 to Discover Novel Promising Sulfide Prodrugs with Improved Safety and Potent Activity for Neutrophil-Mediated Antifungal Immunotherapy.

Neutrophil-mediated immunotherapy is a promising strategy for treating Candida albicans infection due to its potential in dealing with drug-resistant events. Our previous study found that ACT001 exhibited good antifungal immunotherapeutic activity by inhibiting PD-L1 expression in neutrophils, but its strong cytotoxicity and high BBB permeability hindered its antifungal application. To address these deficiencies, a series of novel sulfide derivatives were designed and synthesized based on a slow-release prodrug strategy. Among these derivatives, compound 16 exhibited stronger inhibition of PD-L1 expression, less cytotoxicity to neutrophils, and lower BBB permeability than ACT001. Compound 16 also significantly enhanced neutrophil-mediated antifungal immunity in C. albicans infected mice, with acceptable pharmacokinetic properties and good oral safety. Moreover, pharmacological mechanism studies demonstrated that ACT001 and compound 16 reduced PD-L1 expression in neutrophils by directly targeting STAT3. Briefly, this study provided a novel prototype compound 16 which exhibited great potential in neutrophil-mediated antifungal immunotherapy.

The protective effects of Arctiin in asthma by attenuating airway inflammation and inhibiting p38/NF-κB signaling.

Asthma is a common chronic inflammatory disease of the airways, which affects millions of people worldwide. Arctiin, a bioactive molecule derived from the traditional Chinese Burdock, has not been previously reported for its effects on asthma in infants. In this study, an asthma model was established in mice by stimulation with ovalbumin (OVA). Bronchoalveolar lavage (BALF) was collected from OVA-challenged mice and the cells were counted. Lung tissue was harvested for hematoxylin-eosin (HE) staining and measurement of Wet/Dry weight ratios. The expressions of proteins were detected using enzyme-linked immunosorbent assay (ELISA) and Western blots. The superoxide dismutase (SOD) activity in lung tissue was measured using a commercial kit. We found that Arctiin had beneficial effects on asthma treatment. Firstly, it attenuated OVA-challenged lung pathological alterations. Secondly, it ameliorated pro-inflammatory response by reducing the number of inflammatory cells and mitigating the imbalance of Th1/Th2 factors in the bronchoalveolar lavage (BALF) of OVA-challenged mice. Importantly, Arctiin ameliorated OVA-induced lung tissue impairment and improved lung function. Additionally, we observed that oxidative stress (OS) in the pulmonary tissue of OVA-challenged mice was ameliorated by Arctiin. Mechanistically, Arctiin prevented OVA-induced activation of p38 and nuclear factor-κB (NF-κB). Based on these findings, we conclude that Arctiin might serve as a promising agent for the treatment of asthma.

Impact of Linker Groups on Self-Assembly, Gene Transfection, Antibacterial Activity, and In Vitro Cytotoxicity of Cationic Bolaamphiphiles.

Cationic bolaamphiphiles have gained significant attention in various research fields, including materials science, drug delivery, and gene therapy, due to their unique properties and potential applications. The objective of the current research is to develop more effective cationic bolaamphiphiles. Thus, we have designed and synthesized two cationic bolaamphiphiles (-(CH2)12(2,3-dihydroxy-N,N-dimethyl-N-(3-ureidopropyl)propan-1-aminium chloride))2 (C12(DDUPPAC)2)) and (-(CH2)12(N-(3-(carbamoyloxy)propyl)-2,3-dihydroxy-N,N-dimethylpropan-1-aminium chloride)2 (C12(CPDDPAC)2) containing urea and urethane linkages, respectively. We have investigated their self-assembly properties in water using several techniques, including surface tension, electrical conductivity, fluorescence probe, calorimetry, dynamic light scattering, and atomic force microscopy. Their biological applications, e.g., in vitro gene transfection, antibacterial activity, and cytotoxicity, were studied. Both bolaamphiphiles were observed to produce aggregates larger than spherical micelles above a relatively low critical aggregation concentration (cac). The calorimetric experiments suggested the thermodynamically favorable spontaneous aggregation of both bolaforms in water. The results of interaction studies led to the conclusion that C12(CPDDPAC)2 binds DNA with a greater affinity than C12(DDUPPAC)2. Also, C12(CPDDPAC)2 is found to act as a more efficient gene transfection vector than C12(DDUPPAC)2 in 264.7 cell lines. The in vitro cytotoxicity assay using MTT, however, revealed that neither of the bolaamphiphiles was toxic, even at higher quantities. Additionally, both bolaforms show beneficial antibacterial activity.

Conditions and Mechanism of Formation of the Maillard Reaction Pigment, Furpenthiazinate, in a Model System and in Some Acid Hydrolyzates of Foods and its Biological Properties.

Furpenthiazinate is a yellow pigment formed by the Maillard reaction between cysteine and furfural under strongly acidic conditions. Here, we describe the conditions and mechanism of pigment formation in a model system and in an acid hydrolyzate of food and analyze its biological properties. A reaction solution containing 32 mM cysteine and 128 mM furfural or 64 mM cysteine and 256 mM furfural in the presence of 2-6 M hydrochloric acid that was heated to 110 °C for 1-2 h yielded approximately 3 mM furpenthiazinate. Nuclear magnetic resonance analysis of furpenthiazinate prepared using 1-13C or 5-13C d-ribose suggests that it was formed through the condensation of cysteine and two C5 chains derived from pentose with the dehydration and elimination of formic acid. Furpenthiazinate was detected in mieki, a seasoning, and some acid hydrolyzates of food, and it did not show antibacterial or mutagenic activity.

Effects of Eribulin on the RNA Content of Extracellular Vesicles Released by Metastatic Breast Cancer Cells.

Extracellular vesicles (EVs) are small lipid particles secreted by almost all human cells into the extracellular space. They perform the essential function of cell-to-cell communication, and their role in promoting breast cancer progression has been well demonstrated. It is known that EVs released by triple-negative and highly aggressive MDA-MB-231 breast cancer cells treated with paclitaxel, a microtubule-targeting agent (MTA), promoted chemoresistance in EV-recipient cells. Here, we studied the RNA content of EVs produced by the same MDA-MB-231 breast cancer cells treated with another MTA, eribulin mesylate. In particular, we analyzed the expression of different RNA species, including mRNAs, lncRNAs, miRNAs, snoRNAs, piRNAs and tRNA fragments by RNA-seq. Then, we performed differential expression analysis, weighted gene co-expression network analysis (WGCNA), functional enrichment analysis, and miRNA-target identification. Our findings demonstrate the possible involvement of EVs from eribulin-treated cells in the spread of chemoresistance, prompting the design of strategies that selectively target tumor EVs.

Exploring correlations between soy sauce components and the formation of thermal contaminants during low-salt solid-state fermentation.

Soy sauce is a traditional seasoning in Asia and provides a unique flavor to food. However, some harmful Maillard reaction products (MRPs) were inevitably formed during the manufacturing process. Fermentation is a critical step of soy sauce manufacturing and has a significant impact on MRPs formation. Therefore, this study investigated the formation of some characteristic MRPs (e.g., furan, carboxymethyl lysine (CML), 5-hydroxymethylfurfural (5-HMF), α-dicarbonyl compounds) and their correlation with major quality indicators (e.g., free amino acids, reducing sugar, total acid, ammonia nitrogen, total nitrogen, non-salt soluble solids) in low-salt solid-state fermentation soy sauce (LSFSS). The result showed that the levels of furan, CML, and 5-HMF continue to increase during the fermentation process, reaching a maximum after sterilization. Further testing using Person correlation showed that the formation of furan, CML, and 5-HMF in LSFSS was positively correlated with glucose, fructose, α-dicarbonyl compounds, and most of the amino acids, while it was negatively correlated with sucrose and methionine. Among them, the contribution of lysine, valine, isoleucine, leucine, and arginine to furan formation has rarely been reported. Our results provide a good theoretical basis for the control of MRPs during LSFSS fermentation.

Volatile communication in plants relies on a KAI2-mediated signaling pathway.

Plants are constantly exposed to volatile organic compounds (VOCs) that are released during plant-plant communication, within-plant self-signaling, and plant-microbe interactions. Therefore, understanding VOC perception and downstream signaling is vital for unraveling the mechanisms behind information exchange in plants, which remain largely unexplored. Using the hormone-like function of volatile terpenoids in reproductive organ development as a system with a visual marker for communication, we demonstrate that a petunia karrikin-insensitive receptor, PhKAI2ia, stereospecifically perceives the (-)-germacrene D signal, triggering a KAI2-mediated signaling cascade and affecting plant fitness. This study uncovers the role(s) of the intermediate clade of KAI2 receptors, illuminates the involvement of a KAI2ia-dependent signaling pathway in volatile communication, and provides new insights into plant olfaction and the long-standing question about the nature of potential endogenous KAI2 ligand(s).

Development and characterization of liposomal formulations containing sesquiterpene lactones for the treatment of chronic gout.

Gout and hyperuricemia are characterized by high uric acid levels, and their treatment involves medications that have adverse effects. In this study, we evaluated oral liposomal formulations with eremantholide C and goyazensolide as a novel approach to reduce the toxicity associated with these substances while maintaining their anti-hyperuricemic activity. We characterized the formulations and evaluated them based on encapsulation efficiency and stability over 12 months and under simulated physiological environments. We determined the toxicity of the liposomal formulations in Caco-2 cells and the anti-hyperuricemic activity in rats. The formulations exhibited nanometric size, a narrow size distribution, and a negative zeta potential, indicating their stability and uniformity. The efficient encapsulation of the sesquiterpene lactones within the liposomes emphasizes their potential for sustained release and therapeutic efficacy. Stability evaluation revealed a small decrease in the eremantholide C concentration and a remarkable stability in the goyazensolide concentration. In Caco-2 cells, the liposomes did not exert toxicity, but did exhibit an antiproliferative effect. In vivo assays demonstrated that the liposomes reduced serum uric acid levels. Our study represents an advancement in gout and hyperuricemia treatment. The liposomal formulations effectively reduced the toxicity associated with the sesquiterpene lactones while maintaining their therapeutic effects.

Isoegomaketone alleviates inflammatory response and oxidative stress in sepsis lung injury.

BACKGROUND: Sepsis is a life-threatening condition characterized by acute organ dysfunction, which frequently leads to acute lung injury (ALI) in approximately 40% of cases. Isoegomaketone (IK) is a constituent of essential oil found in P. frutescens, known for its diverse biological properties, including anti-inflammatory and antitumor effects. However, the regulatory impact of IK on ALI in the context of sepsis remains poorly understood. METHODS: Pathological alterations in lung tissues were assessed using hematoxylin and eosin staining. Enumeration of total leukocytes and neutrophils in bronchoalveolar lavage fluid (BALF) was performed using a hematocytometer, while the levels of interleukin (IL)-6, IL-1ß, IL-10, and IL-17 in BALF were quantified using enzyme-linked immunosorbent serological assay. In addition, the levels of malondialdehyde (MDA), myeloperoxidase (MPO), superoxide dismutase (SOD), and glutathione (GSH) in lung tissues were assessed using respective commercial kits; cell apoptosis was evaluated using the terminal deoxynucleotide transferase--mediated dUTP nick end-labeling assay, and protein expressions were determined through Western blot analysis. RESULTS: Our findings revealed that cecal ligation and puncture (CLP) treatment in mice induced severe lung injury, characterized by increased lung injury scores, significant bleeding, neutrophil infiltration, and alveolar edema. However, treatment with IK at a dose of 10 mg/kg ameliorated CLP-induced lung injury, while IK dose of 5 mg/kg showed no significant effect. Additionally, IK treatment at 10 mg/kg reduced CLP-induced inflammation by decreasing levels of IL-6, IL-1ß, IL-10, and IL-17. Furthermore, IK at 10 mg/kg attenuated CLP-induced oxidative stress by modulating levels of MDA, MPO, SOD, and GSH. Moreover, IK treatment with a dose of 10 mg/kg activated the nuclear factor erythroid 2-related factor 2-heme oxygenase-1 (Nrf2-HO-1) pathway by enhancing the protein expressions of Nrf2 and HO-1. CONCLUSION: This study demonstrates that IK could mitigate the inflammatory response and oxidative stress associated with sepsis-induced ALI, supporting IK as a promising therapeutic agent for the treatment of sepsis-associated ALI.

Involvement of ferroptosis in eribulin-induced cytotoxicity in ovarian clear cell carcinoma.

Ovarian clear cell carcinoma (OCCC) is a unique clinicopathological subtype of epithelial ovarian cancer that is resistant to standard chemotherapy. Eribulin, a microtubule dynamics inhibitor of halichondrin class, has unique effects in the cancer microenvironment such as induction of epithelization and reduction in metastatic potential in breast cancer cells; however, nothing is known about the effect of eribulin and the detailed mechanisms in OCCC. This study aimed to investigate the involvement of ferroptosis and its mechanism in the antitumor activity of eribulin in OCCC cells and a mouse xenograft model. We found that eribulin-induced cell death was reduced by ferroptosis inhibitors; deferoxamine, an iron chelator and ferrostatin-1, a lipid peroxidation inhibitor. Eribulin increased the levels of intracellular iron, reactive oxygen species (ROS), and lipid peroxides, and increased the mitochondrial membrane potential. Eribulin downregulated the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), the mitochondrial enzyme dihydroorotate dehydrogenase (DHODH), and superoxide dismutase (SOD) activity. The combination of eribulin and ML210, a glutathione peroxidase 4-inhibiting ferroptosis inducer, had a synergistic effect on ferroptosis. Taken together, our findings show firstly that eribulin triggers ferroptosis in OCCC and this effect occurs via the suppression of the Nrf2-HO-1 signaling pathway, SOD activity and the promotion of lipid peroxidation. These findings suggest that eribulin-induced ferroptosis is associated with its anti-tumor effect and also could be a potential therapeutic target in OCCC.

Alleviative effects of the parthenolide derivative ACT001 on insulin resistance induced by sodium propionate combined with a high-fat diet and its potential mechanisms.

The increasing side effects of traditional medications used to treat type II diabetes have made research into the development of safer and more effective natural medications necessary. ACT001, a derivative of parthenolide, has been shown to have good anti-inflammatory and antitumor effects; however, its role in diabetes is unclear. The short-chain fatty acid propionate is a common food preservative that has been found to cause disturbances in glucose metabolism in mice and humans. This study aimed to investigate whether sodium propionate could aggravate insulin resistance in obese mice and cause diabetes and to study the alleviative effects and potential mechanisms of action of ACT001 on insulin resistance in diabetic mice. Type II diabetic mice were adminietered sodium propionate combined with a high-fat diet (HFD + propionate) by gavage daily for four weeks. Biochemical analysis showed that ACT001 significantly affected blood glucose concentration in diabetic mice, mainly by downregulating the expression of phosphoenolpyruvate carboxykinase 2 and glucose-6-phosphatase. Meanwhile, the level of fatty acid-binding protein 4 in the liver was significantly decreased. ACT001 has a protective effect on the liver and adipose tissue of mice. In addition, the results of the running wheel experiment indicated that ACT001 alleviated the circadian rhythm disorder caused by insulin resistance to a certain extent. This study revealed the potential mechanism by which ACT001 alleviates insulin resistance and provides ideas for developing natural antidiabetic drugs.

Integrated Proteomics Characterization of NLRP3 Inflammasome Inhibitor MCC950 in Monocytic Cell Line Confirms Direct MCC950 Engagement with Endogenous NLRP3.

Inhibition of the NLRP3 inflammasome is a promising strategy for the development of new treatments for inflammatory diseases. MCC950 is a potent and selective small-molecule inhibitor of the NLRP3 pathway and has been validated in numerous species and disease models. Although the capacity of MCC950 to block NLRP3 signaling is well-established, it is still critical to identify the mechanism of action and molecular targets of MCC950 to inform and derisk drug development. Quantitative proteomics performed in disease-relevant systems provides a powerful method to study both direct and indirect pharmacological responses to small molecules to elucidate the mechanism of action and confirm target engagement. A comprehensive target deconvolution campaign requires the use of complementary chemical biology techniques. Here we applied two orthogonal chemical biology techniques: compressed Cellular Thermal Shift Assay (CETSA) and photoaffinity labeling chemoproteomics, performed under biologically relevant conditions with LPS-primed THP-1 cells, thereby deconvoluting, for the first time, the molecular targets of MCC950 using chemical biology techniques. In-cell chemoproteomics with inlysate CETSA confirmed the suspected mechanism as the disruption of inflammasome formation via NLRP3. Further cCETSA (c indicates compressed) in live cells mapped the stabilization of NLRP3 inflammasome pathway proteins, highlighting modulation of the targeted pathway. This is the first evidence of direct MCC950 engagement with endogenous NLRP3 in a human macrophage cellular system using discovery proteomics chemical biology techniques, providing critical information for inflammasome studies.

Antiproliferative activities through accelerating autophagic flux by basidalin and its analogs in human cancer cells.

Basidalin, isolated from the basidiomycete Leucoagaricus naucina, has previously demonstrated antibacterial and antitumor properties against murine cancer cells in vivo, but its effects on human cancer cells remain unknown. In this study, we found that basidalin possesses antiproliferative activity against human cancer cell lines. To elucidate the antiproliferative mechanism of basidalin, we focused on autophagy. Treatment with basidalin led to an increase in LC3-II expression level, and accelerated autophagic flux through an mTOR-independent pathway. Moreover, according to the structure-activity relationship analysis-including newly synthesized basidalin analogs-the formyl group, not the amino group, contributes to the antiproliferative activities of basidalin against human cancer cells. Additionally, the antiproliferative activity of basidalin analogs was strongly correlated with autophagy-inducing activity, indicating that basidalin exhibits antiproliferative activity through autophagy induction. These data suggest that basidalin, characterized by its ability to upregulate autophagic flux, emerges as a novel anticancer drug.