RESUMEN
Alzheimer's disease (AD) is a major cause of dementia and one of the most common chronic diseases affecting the aging population. Because AD is considered a public health priority, there is a critical need to discover novel and effective agents for the treatment of this condition. In view of the known contribution of up-regulated glutaminyl cyclase (QC) and glycogen synthase kinase-3ß (GSK-3ß) to the initiation of AD, we previously evaluated a series of dual inhibitors containing maleimide and imidazole motifs as potential anti-AD agents. Here, we assessed another series of hybrids containing maleimide and imidazole motifs to gain an in-depth understanding of the structure-activity relationship (SAR). Based on the primary screening, the introduction of 5-methyl imidazole at one side of the molecule did not enhance the QC-specific inhibitory activity of these hybrids (2, IC50 = 1.22 µM), although the potency was increased by 2' substitution on the maleimide motif at the other side of the molecule. Interestingly, compounds containing 5-methyl imidazole exhibited stronger GSK-3ß-specific inhibitory activity (2, IC50 = 0.0021 µM), and the electron-withdrawing group and 2' and 3' substitution were favorable. Further investigation of substitutions on the maleimide motif in compounds 14-35 revealed that QC-specific inhibition in the presence of piperidine was improved by introduction of a methoxy group (R2). Increasing the linker length and introduction of a methoxy group (R2) also increased the GSK-3ß-specific inhibitory potency. These findings were further confirmed by molecular docking analysis of 33 and 24 with QC and GSK-3ß. Overall, these hybrids exhibited enhanced inhibitory potency against both QC and GSK-3ß, highlighting an important strategy for improving the potency of hybrids as dual-targeting anti-AD agents.
Asunto(s)
Aminoaciltransferasas , Glucógeno Sintasa Quinasa 3 beta , Imidazoles , Maleimidas , Relación Estructura-Actividad , Maleimidas/química , Maleimidas/farmacología , Maleimidas/síntesis química , Imidazoles/química , Imidazoles/farmacología , Imidazoles/síntesis química , Humanos , Glucógeno Sintasa Quinasa 3 beta/antagonistas & inhibidores , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Aminoaciltransferasas/antagonistas & inhibidores , Aminoaciltransferasas/metabolismo , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/síntesis química , Estructura Molecular , Enfermedad de Alzheimer/tratamiento farmacológico , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Glucógeno Sintasa Quinasa 3/metabolismo , Relación Dosis-Respuesta a DrogaRESUMEN
An efficient protocol for direct coupling of maleimides and indolines at the C7-position was achieved under Rh(III) catalysis. Thirty four novel indoline-maleimide conjugates were prepared in good to excellent yields using this method. All compounds were evaluated for their anti-proliferative effect against colorectal cell lines. Among them, compound 3ab showed the most potent anti-proliferative activity against the CRC cells, and displayed low toxicity in the normal cell. Further investigation indicated that 3ab could effectively suppress the proliferation and migration of CRC cells, along with inducing cell cycle arrest and apoptosis. Mechanistic studies revealed that compound 3ab inhibited the proliferation of CRC cells via suppressing the AKT/GSK-3ß pathway. In vivo evaluation demonstrated remarkable antitumor effect of 3ab (10 mg/kg) in the HCT116 xenograft model with no obvious toxicity, which is superior to that of 5-Fluorouracil (20 mg/kg). Therefore, conjugate 3ab could be considered as a potential CRC therapy agent for further development.
Asunto(s)
Antineoplásicos , Apoptosis , Proliferación Celular , Neoplasias Colorrectales , Diseño de Fármacos , Ensayos de Selección de Medicamentos Antitumorales , Indoles , Maleimidas , Humanos , Antineoplásicos/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/patología , Indoles/química , Indoles/farmacología , Indoles/síntesis química , Maleimidas/química , Maleimidas/síntesis química , Maleimidas/farmacología , Proliferación Celular/efectos de los fármacos , Animales , Relación Estructura-Actividad , Apoptosis/efectos de los fármacos , Estructura Molecular , Ratones , Relación Dosis-Respuesta a Droga , Ratones Desnudos , Línea Celular Tumoral , Ratones Endogámicos BALB C , Movimiento Celular/efectos de los fármacosRESUMEN
The Golgi apparatus (GA) is central in shuttling proteins from the endoplasmic reticulum to different cellular areas. Therefore, targeting the GA to precisely destroy its proteins through local heat could induce apoptosis, offering a potential avenue for effective cancer therapy. Herein, a GA-targeted photothermal agent based on protein anchoring is introduced for enhanced photothermal therapy of tumor through the modification of near-infrared molecular dye with maleimide derivative and benzene sulfonamide. The photothermal agent can actively target the GA and covalently anchor to its sulfhydryl proteins, thereby increasing its retention within the GA. Under laser irradiation, the heat generated by the photothermal agent efficiently disrupts sulfhydryl proteins in situ, leading to GA dysfunction and ultimately inducing cell apoptosis. In vivo experiments demonstrate that the photothermal agent can precisely treat tumors and significantly reduce side effects.
Asunto(s)
Aparato de Golgi , Terapia Fototérmica , Aparato de Golgi/metabolismo , Aparato de Golgi/efectos de los fármacos , Terapia Fototérmica/métodos , Animales , Humanos , Ratones , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Neoplasias/terapia , Neoplasias/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Ratones Desnudos , Ratones Endogámicos BALB C , Maleimidas/química , Maleimidas/farmacologíaRESUMEN
Inhibition of protein kinase C (PKC) efficiently promoted the self-renewal of embryonic stem cells (ESCs). However, information about the function of PKC inhibition remains lacking. Here, RNA-sequencing showed that the addition of Go6983 significantly inhibited the expression of de novo methyltransferases (Dnmt3a and Dnmt3b) and their regulator Dnmt3l, resulting in global hypomethylation of DNA in mouse ESCs. Mechanistically, PR domain-containing 14 (Prdm14), a site-specific transcriptional activator, partially contributed to Go6983-mediated repression of Dnmt3 genes. Administration of Go6983 increased Prdm14 expression mainly through the inhibition of PKCδ. High constitutive expression of Prdm14 phenocopied the ability of Go6983 to maintain` mouse ESC stemness in the absence of self-renewal-promoting cytokines. In contrast, the knockdown of Prdm14 eliminated the response to PKC inhibition and substantially impaired the Go6983-induced resistance of mouse ESCs to differentiation. Furthermore, liquid chromatography-mass spectrometry profiling and Western blotting revealed low levels of Suv39h1 and Suv39h2 in Go6983-treated mouse ESCs. Suv39h enzymes are histone methyltransferases that recognize dimethylated and trimethylated histone H3K9 specifically and usually function as transcriptional repressors. Consistently, the inhibition of Suv39h1 by RNA interference or the addition of the selective inhibitor chaetocin increased Prdm14 expression. Moreover, chromatin immunoprecipitation assay showed that Go6983 treatment led to decreased enrichment of dimethylation and trimethylation of H3K9 at the Prdm14 promoter but increased RNA polymerase ⠡ binding affinity. Together, our results provide novel insights into the pivotal association between PKC inhibition-mediated self-renewal and epigenetic changes, which will help us better understand the regulatory network of stem cell pluripotency.
Asunto(s)
Proteínas de Unión al ADN , Células Madre Embrionarias de Ratones , Proteína Quinasa C , Animales , Ratones , Metilación de ADN , Proteínas de Unión al ADN/metabolismo , Indoles/farmacología , Maleimidas/farmacología , Células Madre Embrionarias de Ratones/efectos de los fármacos , Células Madre Embrionarias de Ratones/enzimología , Células Madre Embrionarias de Ratones/fisiología , Proteína Quinasa C/genética , Proteína Quinasa C/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Inhibidores de Proteínas Quinasas/farmacologíaRESUMEN
In the present work, we report a new series of potent SARS-CoV-2 Main Protease (Mpro) inhibitors based on maleimide derivatives. The inhibitory activities were tested in an enzymatic assay using recombinant Mpro (3CL Protease from coronavirus SARS-CoV-2). Within the set of new Mpro inhibitors, 6e demonstrated the highest activity in the enzymatic assay with an IC50 value of 8.52 ± 0.44 µM. The IC50 value for Nirmatrelvir (PF-07321332, used as a reference) was 0.84 ± 0.37 µM. The cytotoxic properties were determined in the MTT assay using MRC-5 and HEK-293 cell lines. In the course of the investigation, we found that the newly obtained maleimide derivatives are not substantially cytotoxic (IC50 values for most compounds were above 200 µM).
Asunto(s)
COVID-19 , Humanos , Células HEK293 , SARS-CoV-2 , Maleimidas/farmacología , Lactamas , Leucina , Nitrilos , Inhibidores de Proteasas/farmacología , Simulación del Acoplamiento Molecular , Antivirales/farmacologíaRESUMEN
Maleimide-containing prodrugs can quickly and selectively react with circulating serum albumin following their injection in the bloodstream. The drug-albumin complex then benefits from longer blood circulation times and better tumor accumulation. Herein, we have applied this strategy to a previously reported highly phototoxic Ru polypyridyl complex-based photosensitizer to increase its accumulation at the tumor, reduce off-target cytotoxicity, and therefore improve its pharmacological profile. Specifically, two complexes were synthesized bearing a maleimide group: one complex with the maleimide directly incorporated into the bipyridyl ligand, and the other has a hydrophilic linker between the ligand and the maleimide group. Their interaction with albumin was studied in-depth, revealing their ability to efficiently bind both covalently and noncovalently to the plasma protein. A crucial finding is that the maleimide-functionalized complexes exhibited significantly lower cytotoxicity in noncancerous cells under dark conditions compared to the nonfunctionalized complex, which is a highly desirable property for a photosensitizer. The binding to albumin also led to a decrease in the phototoxicity of the Ru bioconjugates in comparison to the nonfunctionalized complex, probably due to a decreased cellular uptake. Unfortunately, this decrease in phototoxicity was not compensated by a dramatic increase in tumor accumulation, as was demonstrated in a tumor-bearing mouse model using inductively coupled plasma mass spectrometry (ICP-MS) studies. Consequently, this study provides valuable insight into the future design of in situ albumin-binding complexes for photodynamic therapy in order to maximize their effectiveness and realize their full potential.
Asunto(s)
Antineoplásicos , Complejos de Coordinación , Neoplasias , Fotoquimioterapia , Rutenio , Animales , Ratones , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química , Rutenio/farmacología , Rutenio/química , Ligandos , Albúmina Sérica , Maleimidas/farmacología , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Antineoplásicos/químicaRESUMEN
Injectable hydrogels show great promise in developing novel regenerative medicine solutions and present advantages for minimally invasive applications. Hydrogels based on extracellular matrix components, such as collagen, have the benefits of cell adhesiveness, biocompatibility, and degradability by enzymes. However, to date, reported collagen hydrogels possess severe shortcomings, such as nonbiocompatible cross-linking chemistry, significant swelling, limited range of mechanical properties, or gelation kinetics unsuitable for in vivo injection. To solve these issues, we report the design and characterization of an injectable collagen hydrogel based on covalently modified acetyl thiol collagen cross-linked using thiol-maleimide click chemistry. The hydrogel is injectable for up to 72 h after preparation, shows no noticeable swelling, is transparent, can be molded in situ, and retains its shape in solution for at least one year. Notably, the hydrogel mechanical properties can be fine-tuned by simply adjusting the reactant stoichiometries, which to date was only reported for synthetic polymer hydrogels. The biocompatibility of the hydrogel is demonstrated in vitro using human corneal epithelial cells, which maintain viability and proliferation on the hydrogels for at least seven days. Furthermore, the developed hydrogel showed an adhesion strength on soft tissues similar to fibrin glue. Additionally, the developed hydrogel can be used as a sealant for repairing corneal perforations and can potentially alleviate the off-label use of cyanoacrylate tissue adhesive for repairing corneal perforations. Taken together, these characteristics show the potential of the thiol collagen hydrogel for future use as a prefabricated implant, injectable filler, or as sealant for corneal repair and regeneration.
Asunto(s)
Perforación Corneal , Hidrogeles , Humanos , Hidrogeles/farmacología , Hidrogeles/química , Química Clic , Compuestos de Sulfhidrilo/química , Colágeno/farmacología , Colágeno/química , Maleimidas/farmacologíaRESUMEN
Candidiasis caused by Candida albicans infection has long been a serious human health problem. The pathogenicity of C. albicans is mainly due to its virulence factors, which are novel targets of antifungal drugs for low risk of resistance development. In this study, we identified a maleimide compound [1-(4-methoxyphenyl)-1hydro-pyrrole-2,5-dione, MPD] that exerts effective anti-virulence activity. It could inhibit the process of adhesion, filamentation, and biofilm formation in C. albicans. In addition, it exhibited low cytotoxicity, hemolytic activity, and drug resistance development. Moreover, in Galleria mellonella-C. albicans (in vivo) infection model, the survival time of infected larvae was significantly prolonged under the treatment of MPD. Further, mechanism research revealed that MPD increased farnesol secretion by upregulating the expression of Dpp3. The increased farnesol inhibited the activity of Cdc35, which then decreased the intracellular cAMP content resulting in the inhibition of virulence factors via the Ras1-cAMP-Efg1 pathway. In all, this study evaluated the inhibitory effect of MPD on various virulence factors of C. albicans and identified the underlying mechanisms. This suggests a potential application of MPD to overcome fungal infections in clinics.
Asunto(s)
Candida albicans , Candidiasis , Animales , Humanos , Candida albicans/metabolismo , Factores de Virulencia/metabolismo , Farnesol/farmacología , Candidiasis/microbiología , Antifúngicos/uso terapéutico , Maleimidas/metabolismo , Maleimidas/farmacología , Maleimidas/uso terapéutico , Biopelículas , HifaRESUMEN
In these studies, we designed and investigated cyto- and genotoxic potential of five ruthenium cyclopentadienyl complexes bearing different phosphine and phosphite ligands. All of the complexes were characterized with spectroscopic analysis (NMR, FT-IR, ESI-MS, UV-vis, fluorescence and XRD (for two compounds)). For biological studies, we used three types of cells - normal peripheral blood mononuclear (PBM) cells, leukemic HL-60 cells and doxorubicin-resistance HL-60 cells (HL-60/DR). We compared the results obtained with those obtained for the complex with maleimide ligand CpRu(CO)2(η1-N-maleimidato) 1, which we had previously reported. We observed that the complexes CpRu(CO)(PPh3)(η1-N-maleimidato) 2a and CpRu(CO)(P(OEt)3)(η1-N-maleimidato) 3a were the most cytotoxic for HL-60 cells and non-cytotoxic for normal PBM cells. However, complex 1 was more cytotoxic for HL-60 cells than complexes 2a and 3a (IC50 = 6.39 µM vs. IC50 = 21.48 µM and IC50 = 12.25 µM, respectively). The complex CpRu(CO)(P(OPh)3)(η1-N-maleimidato) 3b is the most cytotoxic for HL-60/DR cells (IC50 = 104.35 µM). We found the genotoxic potential of complexes 2a and 3a only in HL-60 cells. These complexes also induced apoptosis in HL-60 cells. Docking studies showed that complexes 2a and CpRu(CO)(P(Fu)3)(η1-N-maleimidato) 2b have a small ability to degrade DNA, but they may cause a defect in DNA damage repair mechanisms leading to cell death. This hypothesis is corroborated with the results obtained in the plasmid relaxation assay in which ruthenium complexes bearing phosphine and phosphite ligands induce DNA breaks.
Asunto(s)
Antineoplásicos , Complejos de Coordinación , Neoplasias , Fosfitos , Rutenio , Humanos , Rutenio/farmacología , Rutenio/química , Ligandos , Leucocitos Mononucleares , Espectroscopía Infrarroja por Transformada de Fourier , Maleimidas/farmacología , Complejos de Coordinación/química , Antineoplásicos/química , Línea Celular TumoralRESUMEN
Development of protein-protein interaction (PPI) inhibitors remains a major challenge. A significant number of PPIs are mediated by helical recognition epitopes; although peptides derived from such epitopes are attractive templates for inhibitor design, they may not readily adopt a bioactive conformation, are susceptible to proteolysis and rarely elicit optimal cell uptake properties. Constraining peptides has therefore emerged as a useful method to mitigate against these liabilities in the development of PPI inhibitors. Building on our recently reported method for constraining peptides by reaction of dibromomaleimide derivatives with two cysteines positioned in an i and i + 4 relationship, in this study, we showcase the power of the method for rapid identification of ideal constraining positions using a maleimide-staple scan based on a 19-mer sequence derived from the BAD BH3 domain. We found that the maleimide constraint had little or a detrimental impact on helicity and potency in most sequences, but successfully identified i, i + 4 positions where the maleimide constraint was tolerated. Analyses using modelling and molecular dynamics (MD) simulations revealed that the inactive constrained peptides likely lose interactions with the protein as a result of introducing the constraint.
Asunto(s)
Proteínas Proto-Oncogénicas c-bcl-2 , Proteínas Proto-Oncogénicas , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Secuencia de Aminoácidos , Proteína bcl-X/metabolismo , Péptidos/química , Epítopos/metabolismo , Maleimidas/farmacología , Apoptosis , Unión ProteicaRESUMEN
A series of alkynyl-containing maleimides with potent anti-tuberculosis (TB) activity was developed through a rigid group substitution strategy based on our previous study. Systematic optimization of the two side chains flanking the maleimide core led to new compounds with potent activity against Mycobacterium tuberculosis (MIC < 1 µg/mL) and low cytotoxicity (IC50 > 64 µg/mL). Among them, compound 29 not only possessed good activity against extensively drug-resistant TB and favorable hepatocyte stability, but also displayed good intracellular antimycobacterial activity in macrophages. This study lays a good foundation for identifying new alkynyl-containing maleimides as promising leads for treating drug-resistant TB.
Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Humanos , Antituberculosos/química , Pruebas de Sensibilidad Microbiana , Maleimidas/farmacologíaRESUMEN
The major challenges in photodynamic therapy (PDT) are the neutralization of cytotoxic reactive oxygen species (ROS) by the excessive antioxidant glutathione (GSH) in tumor cells, high self-aggregation of most photosensitizers (PSs), and long time to protect from light after treatment. Thus, to develop the molecular PSs for the improved and safe PDT in clinic, a novel and versatile PS (Mal-Pc) has been designed by di-substituting maleimides to the axial positions of silicon (â £) phthalocyanine. Owning to the conjugation of maleimides, Mal-Pc can not only entry tumor cells more easily and faster, but also can react with the intracellular overexpressed GSH after entry. In addition, upon electrophilic reaction with GSH, the inhibition of self-aggregation of Mal-Pc has been demonstrated by the restoration of the fluorescence emission in aqueous media. As a result, the intracellular ROS levels and photocytotoxicity of Mal-Pc are dramatically enhanced. Finally, the high hydrophilicity of the product GS-conjugates facilitates Mal-Pc eliminate from the normal cells more rapidly. Overall, this work revealed the high potential of the versatile molecular Mal-Pc for highly efficient and safe PDT in clinical translation.
Asunto(s)
Antineoplásicos , Glutatión , Maleimidas , Fármacos Fotosensibilizantes , Especies Reactivas de Oxígeno , Glutatión/antagonistas & inhibidores , Maleimidas/química , Maleimidas/farmacología , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/farmacología , Especies Reactivas de Oxígeno/antagonistas & inhibidores , Antineoplásicos/química , Antineoplásicos/farmacología , Humanos , Células Hep G2RESUMEN
Acute lung injury (ALI) is an acute inflammatory disease, which severely impacts lung function with a high lethality rate. Chromone and maleimide are very important moieties of anti-inflammatory agents. Here, forty new chromone-maleimide hybrids were readily synthesized using a Heck-type coupling strategy in good yields and were screened for their anti-inflammatory activity. A majority of these hybrids showed high inhibitory potency against LPS-stimulated release of pro-inflammatory cytokines in macrophages. Preliminary structure-activity relationship studies led to the discovery of highly potent inhibitors. Five of them were found to inhibit lipopolysaccharide (LPS)-induced IL-6 and TNF-α release in a dose-dependent manner with IC50 values in the nanomolar rang. Furthermore, in vivo administration of 5e and 5g resulted in distinctly attenuated LPS-induced ALI via inhibiting the inflammation. Thus it is evident from our study that these novel chromone-maleimide hybrids present promising therapeutic potential for ALI.
Asunto(s)
Lesión Pulmonar Aguda , Lipopolisacáridos , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/tratamiento farmacológico , Animales , Antiinflamatorios/efectos adversos , Cromonas , Citocinas , Maleimidas/farmacología , RatonesRESUMEN
Natural enediyne antibiotics are powerful DNA-cleavage agents due to the presence of the highly reactive hex-3-ene-1,5-diyne units. However, the complicated chemical structure and thermal instability make their synthesis, derivatization, and storage challenging. Heterocycle-fused enediynes, which exhibit strong antineoplastic activity, are promising analogues of natural enediynes for medicinal applications. To this end, a series of maleimide-based enediynes with macrocyclic lactone moieties were synthesized through the Sonagashira coupling reaction. Differential scanning calorimetry and electron paramagnetic resonance results showed that these macrocyclic enediynes exhibited a rather low onset temperature and the ability to generate radicals at physiological temperature. In addition, the structure-activity relationship of enediynes was analyzed by changing the ring size and the substituents on the propargyl group. Cellular experiments indicated that the diradicals produced by these enediynes efficiently cleaved DNA and disrupted the cell cycle distribution, and consequently induced tumor cell death via an apoptosis pathway at low half inhibitory concentrations. Computational studies suggested that the maleimide moiety promoted the propargyl-allenyl rearrangement of the cyclic enediyne, enabling the generation of diradical species through the Myers-Saito cyclization, and then abstracted hydrogen atoms from the H-donors.
Asunto(s)
Enediinos , Lactonas , Antibióticos Antineoplásicos , Ciclización , ADN , Enediinos/química , Enediinos/farmacología , Maleimidas/farmacologíaRESUMEN
Showdomycin produced by Streptomyces showdoensis ATCC 15227 is a C-nucleoside microbial natural product with antimicrobial and cytotoxic properties. The unique feature of showdomycin in comparison to other nucleosides is its maleimide base moiety, which has the distinct ability to alkylate nucleophilic thiol groups by a Michael addition reaction. In order to understand structure-activity relationships of showdomycin, we synthesized a series of derivatives with modifications in the maleimide ring at the site of alkylation to moderate its reactivity. The showdomycin congeners were designed to retain the planarity of the base ring system to allow Watson-Crick base pairing and preserve the nucleosidic character of the compounds. Consequently, we synthesized triphosphates of showdomycin derivatives and tested their activity against RNA polymerases. Bromo, methylthio, and ethylthio derivatives of showdomycin were incorporated into RNA by bacterial and mitochondrial RNA polymerases and somewhat less efficiently by the eukaryotic RNA polymerase II. Showdomycin derivatives acted as uridine mimics and delayed further extension of the RNA chain by multi-subunit, but not mitochondrial RNA polymerases. Bioactivity profiling indicated that the mechanism of action of ethylthioshowdomycin was altered, with approximately 4-fold reduction in both cytotoxicity against human embryonic kidney cells and antibacterial activity against Escherichia coli. In addition, the ethylthio derivative was not inactivated by medium components or influenced by addition of uridine in contrast to showdomycin. The results explain how both the maleimide ring and the nucleoside nature contribute to the bioactivity of showdomycin and demonstrates for the first time that the two activities can be separated.
Asunto(s)
Nucleósidos , Showdomicina , Antibacterianos/farmacología , Humanos , Maleimidas/farmacología , ARN , Showdomicina/farmacología , Relación Estructura-Actividad , UridinaRESUMEN
BACKGROUND: Oxidative stress in the intervertebral disc leads to nucleus pulposus (NP) degeneration by inducing cell apoptosis. However, the molecular mechanisms underlying this process remain unclear. Increasing evidence indicates that GSK-3ß is related to cell apoptosis induced by oxidative stress. In this study, we explored whether GSK-3ß inhibition protects human NP cell against apoptosis under oxidative stress. METHODS AND RESULTS: Immunofluorescence staining was used to show the expression of GSK-3ß in human NP cells (NPCs). Flow cytometry, mitochondrial staining and western blot (WB) were used to detect apoptosis of treated NPCs, changes of mitochondrial membrane potential and the expression of mitochondrial apoptosis-related proteins using GSK-3ß specific inhibitor SB216763. Co-Immunoprecipitation (Co-IP) was used to demonstrate the interaction between GSK-3ß and Bcl-2. We delineated the protective effect of GSK-3ß specific inhibitor SB216763 on human NPCs apoptosis induced by oxidative stress in vitro. Further, we showed SB216763 exert the protective effect by preservation of the mitochondrial membrane potential and inhibition of caspase 3/7 activity during oxidative injury. The detailed mechanism underlying the antiapoptotic effect of GSK-3ß inhibition was also studied by analyzing mitochondrial apoptosis pathway in vitro. CONCLUSIONS: We concluded that the GSK-3ß inhibitor SB216763 protected mitochondrial membrane potential to delay nucleus pulposus cell apoptosis by inhibiting the interaction between GSK-3ß and Bcl-2 and subsequently reducing cytochrome c(Cyto-C) release and caspase-3 activation. Together, inhibition of GSK-3ß using SB216763 in NPCs may be a favorable therapeutic strategy to slow intervertebral disc degeneration.
Asunto(s)
Glucógeno Sintasa Quinasa 3 beta , Núcleo Pulposo , Apoptosis/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Glucógeno Sintasa Quinasa 3 beta/antagonistas & inhibidores , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Humanos , Indoles/farmacología , Maleimidas/farmacología , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Núcleo Pulposo/efectos de los fármacos , Núcleo Pulposo/metabolismo , Estrés Oxidativo/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/metabolismoRESUMEN
Streptomyces sp. GET02.ST and Achromobacter sp. GET02.AC were isolated together from the gut of the wharf roach, Ligia exotica, inhabiting the intertidal zone of the west coast of Korea. The co-cultivation of these two strains significantly induced the production of two new metabolites, ligiamycins A (1) and B (2), which were barely detected in the single culture of Streptomyces sp. GET02.ST. The planar structures of ligiamycins A (1) and B (2) were elucidated as new decalins coupled with amino-maleimides by the analysis of various spectroscopic data, including nuclear magnetic resonance (NMR), ultraviolet (UV), and mass (MS) data. The assignment of two nitrogen atoms in amino-maleimide in 1 was accomplished based on 1H-15N heteroatom single quantum coherence spectroscopy (HSQC) NMR experiments. The relative configurations of the ligiamycins were determined using rotating frame Overhauser effect spectroscopy (ROESY) NMR data, and their absolute configurations were deduced by comparing their experimental and calculated optical rotations. Ligiamycin A (1) displayed antibacterial effects against Staphylococcus aureus and Salmonella enterica, while ligiamycin B (2) exhibited mild cell cytotoxicity against human colorectal cancer cells.
Asunto(s)
Antibacterianos , Antineoplásicos , Maleimidas , Naftalenos , Animales , Humanos , Achromobacter/metabolismo , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Línea Celular Tumoral , Técnicas de Cocultivo , Neoplasias Colorrectales/tratamiento farmacológico , Isópodos/microbiología , Naftalenos/química , Naftalenos/aislamiento & purificación , Naftalenos/farmacología , Streptomyces/metabolismo , Maleimidas/química , Maleimidas/aislamiento & purificación , Maleimidas/farmacologíaRESUMEN
Surface stiffness is a unique indicator of various cellular states and events and needs to be tightly controlled. α-Mangostin, a natural compound with numerous bioactivities, reduces the mechanical stiffness of various cells; however, the mechanism by which it affects the actin cytoskeleton remains unclear. We aimed to elucidate the mechanism underlying α-mangostin activity on the surface stiffness of leukocytes. We treated spherical non-adherent myelomonocytic KG-1 cells with α-mangostin; it clearly reduced their surface stiffness and disrupted their microvilli. The α-mangostin-induced reduction in surface stiffness was inhibited by calyculin A, a protein phosphatase inhibitor. α-Mangostin also induced KG-1 cell adhesion to a fibronectin-coated surface. In KG-1 cells, a decrease in surface stiffness and the induction of cell adhesion are largely attributed to the dephosphorylation of ezrin/radixin/moesin proteins (ERMs); α-mangostin reduced the levels of phosphorylated ERMs. It further increased protein kinase C (PKC) activity. α-Mangostin-induced KG-1 cell adhesion and cell surface softness were inhibited by the PKC inhibitor GF109203X. The results of the present study suggest that α-mangostin decreases stiffness and induces adhesion of KG-1 cells via PKC activation and ERM dephosphorylation.
Asunto(s)
Adhesión Celular/efectos de los fármacos , Proteínas del Citoesqueleto/metabolismo , Elasticidad/efectos de los fármacos , Proteínas de la Membrana/metabolismo , Proteínas de Microfilamentos/metabolismo , Xantonas/farmacología , Células Cultivadas , Inhibidores Enzimáticos/farmacología , Humanos , Indoles/farmacología , Maleimidas/farmacología , Fosforilación/efectos de los fármacos , Proteína Quinasa C/antagonistas & inhibidores , Proteína Quinasa C/metabolismoRESUMEN
Currentin vitrothree-dimensional (3D) models of liver tissue have been limited by the inability to study the effects of specific extracellular matrix (ECM) components on cell phenotypes. This is in part due to limitations in the availability of chemical modifications appropriate for this purpose. For example, hyaluronic acid (HA), which is a natural ECM component within the liver, lacks key ECM motifs (e.g. arginine-glycine-aspartic acid (RGD) peptides) that support cell adhesion. However, the addition of maleimide (Mal) groups to HA could facilitate the conjugation of ECM biomimetic peptides with thiol-containing end groups. In this study, we characterized a new crosslinkable hydrogel (i.e. HA-Mal) that yielded a simplified ECM-mimicking microenvironment supportive of 3D liver cell culture. We then performed a series of experiments to assess the impact of physical and biochemical signaling in the form of RGD peptide incorporation and transforming growth factorß(TGF-ß) supplementation, respectively, on hepatic functionality. Hepatic stellate cells (i.e. LX-2) exhibited increased cell-matrix interactions in the form of cell spreading and elongation within HA-Mal matrices containing RGD peptides, enabling physical adhesions, whereas hepatocyte-like cells (HepG2) had reduced albumin and urea production. We further exposed the encapsulated cells to soluble TGF-ßto elicit a fibrosis-like state. In the presence of TGF-ßbiochemical signals, LX-2 cells became activated and HepG2 functionality significantly decreased in both RGD-containing and RGD-free hydrogels. Altogether, in this study we have developed a hydrogel biomaterial platform that allows for discrete manipulation of specific ECM motifs within the hydrogel to better understand the roles of cell-matrix interactions on cell phenotype and overall liver functionality.
Asunto(s)
Materiales Biocompatibles , Ácido Hialurónico , Hidrogeles/química , Maleimidas , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Adhesión Celular/efectos de los fármacos , Técnicas de Cultivo de Célula , Microambiente Celular/efectos de los fármacos , Matriz Extracelular/efectos de los fármacos , Células Hep G2 , Humanos , Ácido Hialurónico/química , Ácido Hialurónico/farmacología , Maleimidas/química , Maleimidas/farmacología , Oligopéptidos/química , Propiedades de SuperficieRESUMEN
INTRODUCTION: Prostate smooth muscle contraction is promoted by receptor-induced activation of intracellular signaling pathways. The presumed involvement in etiology and medical treatment of lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH) imparts a high clinical relevance to prostate smooth muscle contraction, which is contrasted by incomplete understanding at the molecular level. Involvement of protein kinase C (PKC) has been commonly assumed, but available studies were limited to nonhuman prostate smooth muscle or cell cultures. Here, we examined the effects of the PKC inhibitors Go6983 and GF109203x on contractions of human prostate tissues. METHODS: Prostate tissues were obtained from radical prostatectomy. Contractions were induced by electric field stimulation (EFS), α1 -adrenergic agonists (noradrenaline, phenylephrine, methoxamine), thromboxane A2 analog U46619, endothelin-1, or calcium chloride in an organ bath. RESULTS: GF109203X (500 nM) and Go6983 (300 nM) reduced EFS-, noradrenaline-, phenylephrine-, methoxamine-, and U46619-induced contractions of human prostate tissues, with maximum inhibitions approaching up to 55%. Using concentrations of 3 µM, GF109203X and Go6983 inhibited EFS- and noradrenaline-induced contractions, with similar effect sizes as 500 and 300 nM, respectively. Endothelin-1-induced contractions were not inhibited by GF109203X, and to neglectable extent by Go6983. After depolarization in calcium-free solution, calcium chloride-induced concentration-dependent contractions, which were inhibited by GF109203X and Go6983. CONCLUSIONS: GF109203X and Go6983 inhibit neurogenic, α1 -adrenergic, and thromboxane A2 -induced smooth muscle contractions in the human prostate, suggesting a role of PKC for human prostate smooth muscle contraction. The inhibition may by be imparted by inhibition of calcium sensitivity.