RESUMEN
To explore the reaction universality of bridge nitration, the mononitration of different p-tert-butylcalix[4]arene derivatives was executed with tert-butyl nitrite as a nitration reagent. The effects of calix[4]arene conformations, substituents on the lower rim, and reaction conditions on bridge mononitration are systematically studied. The bridge nitration of p-tert-butylcalix[4]arene derivatives in 1,3-alternate, 1,2-alternate, and partial cone conformations can be smoothly executed while that of p-tert-butylcalix[4]arene derivatives strictly regulated in a cone conformation cannot. The nitration product complexity shows a positive correlation with the bridge-hydrogen types, and the optimal bridge-mononitrated substrate is calix[4]arene with only one bridge-hydrogen type. The electron-withdrawing substituent on the lower rim is apparently beneficial for the bridge mononitration. As a result, a variety of bridging chiral p-tert-butylcalix[4]arenes with a mononitro bridge substituent have been successfully synthesized. The highest bridge-mononitrated yield can reach 27% from 1,3-alternate p-tert-butylcalix[4]arene biscrown-5 under optimal reaction conditions.
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The co-contamination with cadmium (Cd) and arsenic (As) in the paddy soil is the most seriously combined pollution of toxic elements in China, and it is rather difficult to decrease bioavailable Cd and As levels in soil because of the opposite ionic forms of bioavailable Cd (cation) and As (anion). This study explored the optimal conditions of Eh and pH in different soils for simultaneous decrease of Cd and As bioavailabilities in the soil-rice system through soil culture and rice pot experiments under water management strategies. The results showed that near neutral soil pH (7.0) were eventually observed under long-term flooding conditions. Under unflooded conditions, soil pH is the dominant factor influencing bioavailabilities of Cd and As, while under flooded conditions, Eh becomes the most important factor. Pot experiments showed that flooding significantly reduced the Cd concentration in rice grains from 54.5% to 95.5%, but concomitantly increased rice As concentration substantially (214%-302%). By evaluating the trade-off value between the bioavailabilities of Cd and As in the soil, the minimal trade-off value was obtained when the soil Eh was -130 mV and the pH was 6.8.
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Arsénico , Oryza , Contaminantes del Suelo , Arsénico/análisis , Cadmio/análisis , Concentración de Iones de Hidrógeno , Suelo , Contaminantes del Suelo/análisis , Agua , Contaminación del Agua , Abastecimiento de AguaRESUMEN
Williams syndrome transcription factor (WSTF) is a transcription factor and tyrosine kinase. WSTF overexpression promotes migration and proliferation of various cancers, and Ser158 (WSTFS158) phosphorylation plays an important role in this process. However, the role of the other posttranslational modifications of WSTF is unknown. Here, we report that lysine (K) 426 on WSTF is acetylated by MOF and deacetylated by SIRT1. Mechanistically, male-specific lethal (MSL) 1v1 interaction with WSTF facilitates its interaction with MOF for WSTF acetylation, which in turn promotes WSTFS158 phosphorylation. The kinase and transcriptional regulatory activity of WSTF were enhanced by acetylation. WSTFK426ac levels positively and significantly correlated with tumor size, histological grade, and age. Moreover, we demonstrated that acetylated WSTF promotes cancer cell proliferation, migration, invasion, and tumor formation. In conclusion, we identified the enzymes regulating WSTF K426 acetylation, and demonstrated an acetylation-dependent mechanism that modulates the activities of WSTF and contributes to tumorigenesis. Our findings provide new clues to study WSTF-mediated normal development and disease.
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Carcinogénesis/patología , Histona Acetiltransferasas/metabolismo , Neoplasias/patología , Factores de Transcripción/metabolismo , Acetilación , Animales , Carcinogénesis/genética , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Femenino , Regulación de la Expresión Génica , Células HEK293 , Histona Acetiltransferasas/genética , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Invasividad Neoplásica/genética , Trasplante de Neoplasias , Fosforilación , Procesamiento Proteico-Postraduccional , Interferencia de ARN , ARN Interferente Pequeño/genética , Sirtuina 1/genética , Sirtuina 1/metabolismo , Trasplante HeterólogoRESUMEN
Multitargeted therapy could rectify various oncogenic pathways to block tumorigenesis and progression. The combination of endocrine-, immune-, and chemotherapy might exert a highly synergistic effect against certain tumors. Herein, a series of smart Pt(IV) prodrugs 3-6, named Melatplatin, were rationally designed not only to multitarget DNA, MT1, and estrogen receptor (ER) but also to activate immune response. Melatplatin, conjugating first-line chemotherapeutic Pt drugs with human endogenous melatonin (MT), significantly enhanced drug efficacy especially in ER high-expression (ER+) cells, among which 3 presented the most potent cytotoxicity toward ER+ MCF-7 with nanomolar IC50 values 100-fold lower than cisplatin. Melatplatin could bind well to melatonin receptor (MT1) according to molecular docking. Besides, 3 evidently increased intracellular accumulation and DNA damage, upregulated γH2AX and P53, and silenced NF-κB to induce massive apoptosis. Most strikingly, 3 effectively inhibited tumor growth and attenuated systemic toxicity compared to cisplatin in vivo, promoting lymphocyte proliferation in spleen to achieve immune modulation.
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Antineoplásicos/química , Platino (Metal)/química , Profármacos/química , Receptor de Melatonina MT1/metabolismo , Receptores de Estrógenos/metabolismo , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Apoptosis/efectos de los fármacos , Sitios de Unión , Puntos de Control del Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Daño del ADN/efectos de los fármacos , Humanos , Sistema Inmunológico/efectos de los fármacos , Sistema Inmunológico/metabolismo , Ratones , Ratones Desnudos , Simulación del Acoplamiento Molecular , FN-kappa B/antagonistas & inhibidores , FN-kappa B/genética , FN-kappa B/metabolismo , Neoplasias/tratamiento farmacológico , Neoplasias/patología , Profármacos/farmacología , Profármacos/uso terapéutico , Estructura Terciaria de Proteína , Receptor de Melatonina MT1/química , Receptores de Estrógenos/químicaRESUMEN
Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of insulin signaling pathway, and more and more studies have shown that it is a potential target for the treatment of type 2 diabetes mellitus (T2DM). In this study, 17 new 4-thiazolinone derivatives were designed and synthesized as novel PTP1B inhibitors, and ADMET prediction confirmed that these compounds were to be drug-like. In vitro enzyme activity experiments were performed on these compounds, and it was found that a plurality of compounds had good inhibitory activity and high selectivity against PTP1B protein. Among them, compound 7p exhibited the best inhibitory activity with an IC50 of 0.92 µM. The binding mode of compound 7p and PTP1B protein was explored, revealing the reason for its high efficiency. In addition, molecular dynamics simulations for the PTP1BWT and PTP1Bcomp#7p systems revealed the effects of compound 7p on PTP1B protein at the molecular level. In summary, the study reported for the first time that 4-thiazolinone derivatives as a novel PTP1B inhibitor had good inhibitory activity and selectivity for the treatment of T2DM, providing more options for the development of PTP1B inhibitors. AbbreviationsBBBblood-brain barrierCDC25Bcell division cycle 25 homolog BCYP2D6Cytochrome P450 2D6 bindingDCCMdynamic cross-correlation mapDSDiscovery StudioH bondhydrogen bondHIAhuman intestinal absorptionLARleukocyte antigen-related phosphataseMDmolecular dynamicsMEG-2maternal-effect germ-cell defective 2MM-PBSAmolecular mechanics Poisson Boltzmann surface area)PCAprincipal component analysisPDBProtein Data BankpNPPp-nitrophenyl phosphatePPBplasma protein bindingPTP1Bprotein tyrosine phosphotase 1BRMSDroot mean square deviationRMSFroot mean square fluctuationSHP-1src homologous phosphatase-1SHP-2src homologous phosphatase-2SPCsingle-point chargeTCPTPT cell protein tyrosine phosphataseT2DMType 2 diabetes mellitusVDWvan der WaalsCommunicated by Ramaswamy H. Sarma.
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Inhibidores Enzimáticos , Proteína Tirosina Fosfatasa no Receptora Tipo 1/antagonistas & inhibidores , Diabetes Mellitus Tipo 2 , Inhibidores Enzimáticos/farmacología , Humanos , Insulina , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Relación Estructura-ActividadRESUMEN
The important role of insulin-like growth factor-1 receptor (IGF-1R) in tumorigenesis has been well established. The classical model involves IGF-1R binding to IGF-1/2, the following activation of PI3K-Akt-signaling cascades, driving cell proliferation and apoptosis inhibition. Here we report a new signal transduction pathway of IGF-1R in the intestinal epithelium. Using heterozygous knockout mice (Igf1r+/-), we analyzed the expressions of viral RNA sensors MDA5 and RIG-I in the intestinal epithelium. Igf1r+/- mice exhibited higher MDA5 and RIG-I than wild-type (WT) mice, indicating that knockdown of IGF-1R could trigger MDA5 and RIG-I. IGF-1R knockdown-triggered MDA5 and RIG-I were further investigated in human colonic cancer cells. Increased MDA5 and RIG-I were clearly seen in the cytoplasm in cancer cells as well as normal human colonic cells with silenced IGF-1R. Notably, the upregulations of MDA5 and RIG-I was not affected by blockage of the PI3K-Akt pathway with LY294002. These results suggested a new signal transduction pathway of IGF-1R. Importantly, IGF-1R knockdown-triggered MDA5 and RIG-I resulted in colorectal cancer apoptosis through activation of the mitochondrial pathway. These in vitro observations were evidenced in the azoxymethane (AOM)-dextran sulfate sodium (DSS) colorectal cancer model of mice. In conclusion, knockdown of IGF-1R triggers viral RNA sensor MDA5- and RIG-I-mediated mitochondrial apoptosis in cancer cells.
RESUMEN
Although insulin-like growth factor-1 receptor (IGF-1R) has been accepted as a major determinant of cancers, its biological roles and corresponding mechanisms in tumorigenesis have remained elusive. Herein, we demonstrate that IGF-1R plays pivotal roles in the regulation of mitochondrial respiratory chain and functions during colitis and tumorigenesis. Heterozygous knockout IGF-1R attenuated azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colitis and colitis associated cancer (CAC) in Igf1r+/- mice. Heterozygous knockout IGF-1R confers resistance to oxidative stress-induced damage on colorectal epithelial cells by protecting mitochondrial dynamics and structures. IGF-1R low expression improves the biological function of mitochondrial fusion under oxidative stress. Mechanically, an increase in respiratory coupling index (RCI) and oxidative phosphorylation index (ADP/O) was seen in colorectal epithelial cells of Igf1r+/- mice. Seahorse XFe-24 analyzer analysis of mitochondrial bioenergetics demonstrated an increase in oxygen consumption rate (OCR) and a decrease of extracellular acidification rate (ECAR) in Igf1r+/- cells. Further analysis suggests the protection mechanisms of Igf1r+/- cells from oxidative stress through the activation of the mitochondrial respiratory chain and LKB1/AMPK pathways. These results highlight the biological roles of IGF-1R at the nexus between oxidative damage and mitochondrial function and a connection between colitis and colorectal cancer.
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Colitis/prevención & control , Neoplasias Colorrectales/prevención & control , Mitocondrias/fisiología , Estrés Oxidativo , Receptor IGF Tipo 1/fisiología , Animales , Proliferación Celular , Colitis/inducido químicamente , Colitis/metabolismo , Colitis/patología , Neoplasias Colorrectales/etiología , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Sulfato de Dextran/toxicidad , Femenino , Heterocigoto , Masculino , Ratones , Ratones Noqueados , Transducción de SeñalRESUMEN
Overexpression of Jumonji domain-containing 6 (JMJD6) has been reported to be associated with more aggressive breast cancer characteristics. However, the precise role of JMJD6 in breast cancer development remains unclear. Here, we demonstrate that JMJD6 has intrinsic tyrosine kinase activity and can utilize ATP and GTP as phosphate donors to phosphorylate Y39 of histone H2A.X (H2A.XY39ph). High JMJD6 levels promoted autophagy in triple negative breast cancer (TNBC) cells by regulating the expression of autophagy-related genes. The JMJD6-H2A.XY39ph axis promoted TNBC cell growth via the autophagy pathway. We show that combined inhibition of JMJD6 kinase activity and autophagy efficiently decreases TNBC growth. Together, these findings suggest an effective strategy for TNBC treatment.
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Autofagia , Histonas/metabolismo , Histona Demetilasas con Dominio de Jumonji/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias de la Mama Triple Negativas/metabolismo , Animales , Femenino , Histonas/genética , Humanos , Histona Demetilasas con Dominio de Jumonji/genética , Ratones , Ratones Endogámicos BALB C , Proteínas de Neoplasias/genética , Fosforilación , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/patologíaRESUMEN
Although a mountain of papers have showed that metformin plays a role in inhibiting cancers, but the mechanism underpinning this has not yet fully elucidated. Herein, we used AOM/DSS model, the clinicopathological features are similar to those found in humans, to investigate the effects of metformin as well as combination with 5-FU in the prevention of colitis and colitis associated cancer (CAC). Oral metformin significantly inhibited DSS-induced ulcerative colitis and AOM/DSS-induced CAC. Metformin also ameliorated 5-FU-induced colorectal gastrointestinal symptoms in mice. Metformin combination with 5-FU strongly inhibited colorectal cancer. Metformin reduced levels of the NFκB signaling components p-IKKα/ß, p-NFκB, p-IκBα in colorectal mucosal cells. Transmission electron microscopy analysis suggested that the inhibition of metformin on colitis and CAC might associate with its biological activity of protecting mitochondrial structures of colorectal epithelial cells. Further analysis by Mito Tracker Red staining assay indicated that metformin prevented H2O2-induced mitochondrial fission correlated with a decrease of mitochondrial perimeter. In addition, metformin increased the level of NDUFA9, a Q-module subunit required for complex I assembly, in colorectal epithelial cells. These observations of metformin in the inhibition of colitis and CAC might associate with its activity of activating the LKB1/AMPK pathway in colorectal epithelial cells. In conclusion, metformin inhibited colitis and CAC through protecting the mitochondrial structures of colorectal epithelial cells.
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Colitis/tratamiento farmacológico , Neoplasias del Colon/tratamiento farmacológico , Células Epiteliales/efectos de los fármacos , Hipoglucemiantes/uso terapéutico , Metformina/uso terapéutico , Mitocondrias/metabolismo , Animales , Modelos Animales de Enfermedad , Humanos , Hipoglucemiantes/farmacología , Metformina/farmacología , Ratones , Transducción de SeñalRESUMEN
BACKGROUND: The relationship between protein structure and its bioactivity is one of the fundamental problems for protein engineering and pharmaceutical design. METHOD: A new method, called SPTD (Simulated Protein Thermal Detection), was proposed for studying and improving the thermal stability of enzymes. The method was based on the evidence observed by conducting the MD (Molecular Dynamics) simulation for all the atoms of an enzyme vibrating from the velocity at a room temperature (e.g., 25°C) to the desired working temperature (e.g., 65°C). According to the recorded MD trajectories and the coordinate deviations of the constituent residues under the two different temperatures, some new strategies have been found that are useful for both drug delivery and starch industry. CONCLUSION: The SPTD technique presented in this paper may become a very useful tool for pharmaceutical design and protein engineering.
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Bacillus/enzimología , Glicósido Hidrolasas/química , Temperatura , Animales , Estabilidad de Enzimas , Glicósido Hidrolasas/metabolismo , Humanos , Ingeniería de ProteínasRESUMEN
PPARα and PPARγ have been the most widely studied Peroxisome proliferator-activated receptor (PPAR) subtypes due to their important roles in regulating glucose, lipids, and cholesterol metabolism. By combining the lowering serum triglyceride levels benefit of PPARα agonists (such as fibrates) with the glycemic advantages of the PPARγ agonists (such as TZD), the dual PPAR agonists approach can both improve the metabolic effects and minimize the side effects caused by either agent alone, and hence, has become a promising strategy for designing effective drugs against type-2 diabetes. In this study, by means of virtual screening, ADMET prediction and molecular dynamics (MD) simulations techniques, one compound-ASN15761007 with high binding score, low toxicity were gained. It was observed by MD simulations that ASN15761007 not only possessed the same function as AZ242 did in activating PPARα and BRL did in activating PPARγ, but also had more favorable conformation for binding to the two receptors. Our results provided an approach to rapidly produce novel PPARα/γ dual agonists which might be a potential lead compound to develop against insulin resistance and hyperlipidemia.
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Diseño de Fármacos , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , PPAR alfa/química , PPAR gamma/química , Secuencia de Aminoácidos , Aminoácidos/química , Sitios de Unión , Simulación por Computador , Ligandos , Conformación Molecular , PPAR alfa/agonistas , PPAR gamma/agonistas , Unión Proteica , Relación Estructura-Actividad CuantitativaRESUMEN
The thiazolidinedione class PPARγ agonists as antidiabetic agents are restricted in clinical use because of the side effects such as edema, weight gain, and heart failure. The single and selective agonism of PPARγ is the main cause of side effects. The multi-target cooperative PPARα/γ dual agonist development is a hot topic in the antidiabetic medicinal chemistry field. Saroglitazar is the first approved PPARα/γ dual agonist, available in India for the treatment of diabetic dyslipidemia. It got rid of these side effects. With the aim of finding more protent PPARα/γ dual agonists, the scaffold hopping was used to replace α-o phenylpropionic acid skeleton of saroglitazar with L-tyrosine skeleton. Then, the structural modification was carried out designing 72 compounds. Considering the importance of chirality, opposite configuration of 72 compounds was also studied. 12 compounds with better -cdocker energy were screened by molecular docking. Subsequently, the pharmacokinetic properties and toxicity evaluated by ADMET prediction, 11 of them showed better properties. Comp#L-17-1 and comp#L-3-1 were regarded as representatives to study the binding stability by molecular dynamics (MD) simulations. The MD simulation results of comp#L-17-1-PPARs (α, γ) and comp#L-3-1-PPARs (α, γ) provided structure reference for the research and development of novel PPARα/γ dual agonists.
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Descubrimiento de Drogas/métodos , Hipoglucemiantes/química , PPAR alfa/agonistas , PPAR gamma/agonistas , Fenilpropionatos/química , Pirroles/química , Diabetes Mellitus/tratamiento farmacológico , Dislipidemias/tratamiento farmacológico , Humanos , Hipoglucemiantes/farmacología , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Fenilpropionatos/farmacología , Pirroles/farmacologíaRESUMEN
Marshallagia marshalli (Nematoda: Trichostrongylidae) infection can lead to serious parasitic gastroenteritis in sheep, goat, and wild ruminant, causing significant socioeconomic losses worldwide. Up to now, the study concerning the molecular biology of M. marshalli is limited. Herein, we sequenced the complete mitochondrial (mt) genome of M. marshalli and examined its phylogenetic relationship with selected members of the superfamily Trichostrongyloidea using Bayesian inference (BI) based on concatenated mt amino acid sequence datasets. The complete mt genome sequence of M. marshalli is 13,891 bp, including 12 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes. All protein-coding genes are transcribed in the same direction. Phylogenetic analyses based on concatenated amino acid sequences of the 12 protein-coding genes supported the monophylies of the families Haemonchidae, Molineidae, and Dictyocaulidae with strong statistical support, but rejected the monophyly of the family Trichostrongylidae. The determination of the complete mt genome sequence of M. marshalli provides novel genetic markers for studying the systematics, population genetics, and molecular epidemiology of M. marshalli and its congeners.
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Enfermedades de los Bovinos/parasitología , Genoma Mitocondrial/genética , Trichostrongyloidea/genética , Tricostrongiloidiasis/veterinaria , Animales , Teorema de Bayes , Bovinos , ADN Mitocondrial/química , ADN Mitocondrial/genética , Marcadores Genéticos/genética , Filogenia , Análisis de Secuencia de ADN/veterinaria , Trichostrongyloidea/aislamiento & purificación , Tricostrongiloidiasis/parasitologíaRESUMEN
MicroRNAs (miRNAs) exhibit a crucial role in the regulation of angiogenesis and tumor progression, of which miR-199a-5p (miR-199a) has been reported to function as a tumor suppressor in multiple malignancies. However, the precise mechanisms underlying miR-199a in hemangiomas (HAs) remain elusive. In this study, we found that miR-199a had low expression level, while proliferating cell nuclear antigen (PCNA) had high expression level in proliferating-phase HAs compared with the involuting-phase HAs and normal tissues. Spearman correlation analysis revealed the negative correlation of miR-199a with PCNA expression in proliferating-phase HAs. In vitro experiments showed that restoration of miR-199a suppressed cell proliferation capability and induced cell apoptosis in HA-derived endothelial cells (HDEC) and CRL-2586 EOMA cells, followed with decreased PCNA expression and increased cleaved caspase-3 expression, but miR-199a inhibitor reversed these effects. Furthermore, HIF1A was identified as a target of miR-199a and had negative correlation with miR-199a expression in proliferating-phase HAs. Overexpression of HIF1A attenuated the anti-proliferation effect of miR-199a mimic in HAs cells. Taken together, our findings demonstrate that miR-199a may inhibit proliferation and induce apoptosis in HAs cells via targeting HIF1A and provide a potential therapeutic target for HAs.
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Apoptosis/genética , Proliferación Celular/genética , Hemangioma/genética , Hemangioma/patología , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , MicroARNs/genética , Caspasa 3/genética , Línea Celular Tumoral , Niño , Preescolar , Células Endoteliales/patología , Femenino , Humanos , Lactante , Masculino , Neovascularización Patológica/patología , Antígeno Nuclear de Célula en Proliferación/genéticaRESUMEN
Endothelial injury and dysfunction followed by endothelial activation and inflammatory cell recruitment are factors contributing to the initiation and progression of atherosclerosis. Oxidized low-density lipoprotein (ox-LDL) promotes inflammation during atherogenesis and lipid deposition in the arterial wall. We observed that stimulation of human umbilical vein endothelial cells (HUVECs) with ox-LDL activated pro-inflammatory cytokine production and apoptosis, inhibited cell migration, and upregulated T-cell immunoglobulin and mucin domain 3 (Tim-3) expression. Tim-3, in turn, protected HUVECs from ox-LDL-induced apoptosis via the JNK pathway and reversed the inhibition of migration. Tim-3 also inhibited ox-LDL-induced inflammatory cytokine production by suppressing NF-κB activation. In addition, Tim-3 increased production of type 2 T helper cells (Th2) and regulatory T cell (Treg)-associated cytokines. Blocking Tim-3 reversed its effects on the inflammatory response to ox-LDL. Thus, Tim-3 signaling may be a "self-control" mechanism in ox-LDL-triggered inflammation in HUVECs. These results identify Tim-3 as a factor in HUVEC activity and suggest its potential in the treatment of atherosclerosis.
RESUMEN
A two-level principal component predictor (2L-PCA) was proposed based on the principal component analysis (PCA) approach. It can be used to quantitatively analyze various compounds and peptides about their functions or potentials to become useful drugs. One level is for dealing with the physicochemical properties of drug molecules, while the other level is for dealing with their structural fragments. The predictor has the self-learning and feedback features to automatically improve its accuracy. It is anticipated that 2L-PCA will become a very useful tool for timely providing various useful clues during the process of drug development.
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The resistance mechanisms that limit the efficacy of retinoid therapy in cancer are poorly understood. Sphingosine kinase 2 (SphK2) is a highly conserved enzyme that is mainly located in the nucleus and endoplasmic reticulum. Unlike well-studied sphingosine kinase 1 (SphK1) located in the cytosol, little has yet understood the functions of SphK2. Here we show that SphK2 overexpression contributes to the resistance of all-trans retinoic acid (ATRA) therapy in colon cancer through rapid degradation of cytoplasmic retinoid X receptor α (RXRα) by lysine 48 (K48)- and lysine 63 (K63)-based polyubiquitination. Human colonic adenocarcinoma HCT-116 cells transfected with SphK2 (HCT-116Sphk2 cells) demonstrate resistance to ATRA therapy as determined by in vitro and in vivo assays. Sphk2 overexpression increases the ATRA-induced nuclear RXRα export to cytoplasm and then rapidly degrades RXRα through the polyubiquitination pathway. We further show that Sphk2 activates the ubiquitin-proteasome system through the signal mechanisms of (1) K48-linked proteosomal degradation and (2) K63-linked ubiquitin-dependent autophagic degradation. These results provide new insights into the biological functions of Sphk2 and the molecular mechanisms that underlie the Sphk2-mediated resistance to retinoid therapy.
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Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Resistencia a Antineoplásicos/genética , Expresión Génica , Fosfotransferasas (Aceptor de Grupo Alcohol)/genética , Receptor alfa X Retinoide/metabolismo , Tretinoina/farmacología , Animales , Autofagia , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/patología , Modelos Animales de Enfermedad , Células HCT116 , Humanos , Ligandos , Ratones , Unión Proteica , Transporte de Proteínas , Proteolisis/efectos de los fármacos , Carga Tumoral/efectos de los fármacos , Ubiquitinación/efectos de los fármacos , Ubiquitinas/metabolismo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Telmisartan, a bifunctional agent of blood pressure lowering and glycemia reduction, was previously reported to antagonize angiotensin II type 1 (AT1) receptor and partially activate peroxisome proliferator-activated receptor γ (PPARγ) simultaneously. Through the modification to telmisartan, researchers designed and obtained imidazo-\pyridine derivatives with the IC50s of 0.49~94.1 nM against AT1 and EC50s of 20~3640 nM towards PPARγ partial activation. For minutely inquiring the interaction modes with the relevant receptor and analyzing the structure-activity relationships, molecular docking and 3D-QSAR (Quantitative structure-activity relationships) analysis of these imidazo-\pyridines on dual targets were conducted in this work. Docking approaches of these derivatives with both receptors provided explicit interaction behaviors and excellent matching degree with the binding pockets. The best CoMFA (Comparative Molecular Field Analysis) models exhibited predictive results of q2=0.553, r2=0.954, SEE=0.127, r2pred=0.779 for AT1 and q2=0.503, r2=1.00, SEE=0.019, r2pred=0.604 for PPARγ, respectively. The contour maps from the optimal model showed detailed information of structural features (steric and electrostatic fields) towards the biological activity. Combining the bioisosterism with the valuable information from above studies, we designed six molecules with better predicted activities towards AT1 and PPARγ partial activation. Overall, these results could be useful for designing potential dual AT1 antagonists and partial PPARγ agonists.
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Bloqueadores del Receptor Tipo 1 de Angiotensina II/química , Imidazoles/química , Modelos Moleculares , PPAR gamma/química , Piridinas/química , Relación Estructura-Actividad Cuantitativa , Receptor de Angiotensina Tipo 1/química , Bloqueadores del Receptor Tipo 1 de Angiotensina II/farmacología , Sitios de Unión , Humanos , Imidazoles/farmacología , Conformación Molecular , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Estructura Molecular , PPAR gamma/antagonistas & inhibidores , Unión Proteica , Piridinas/farmacología , Electricidad EstáticaRESUMEN
Gene expression was examined in hemangiomas (HA), benign, birthmark-like tumors occurring in infancy, and confirmed in HA-derived endothelial cells (HDEC), for which cell proliferation and apoptosis were also assessed. Protein and mRNA accumulation of Rho-associated protein kinase (ROCK), vascular endothelial growth factor (VEGF), Ki-67 and proliferating cell nuclear antigen was significantly higher in proliferating phase HAs than in involuting phase HAs. In contrast, p53 and caspase-3 exhibited higher levels of accumulation in involuting than proliferating HAs. Cell apoptotic indexes were low in proliferating phase HAs and increased in involuting phase HAs. HDECs were treated with the ROCK inhibitor Y-27632. Y-27632 induced p53 expression and downregulated VEGF expression, significantly inhibited cell proliferation, and induced cell apoptosis in HA cells. The inhibitor effects were confirmed in HAs from HDEC-injected nude mice. These results indicated that ROCK is involved in p53-mediated apoptosis and VEGF expression in HA cells and suggested that such inhibition may be exploited for future HA therapies.
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Amidas/administración & dosificación , Hemangioma/tratamiento farmacológico , Piridinas/administración & dosificación , Proteína p53 Supresora de Tumor/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Quinasas Asociadas a rho/metabolismo , Amidas/farmacología , Animales , Apoptosis , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Hemangioma/metabolismo , Humanos , Ratones , Ratones Desnudos , Antígeno Nuclear de Célula en Proliferación/metabolismo , Piridinas/farmacologíaRESUMEN
Peroxisome proliferators-activated receptors (PPARα, γ and δ) are potentially effective targets for Type 2 diabetes mellitus therapy. The severe effects of known glitazones and the successfully approved agents (saroglitazar and lobeglitazone) motivated us to study novelly potent PPARs drugs with improved safety profile. In this work, we received 15 carboxylic acids based on the combination principle to integrate the polar head of bezafibrate with the hydrophobic tail of pioglitazone. Another 12 tetrazoles based on the bioisosterism principle were obtained accordingly. Furthermore, in vitro PPARs transactivation assays on these 3- or 4-alkoxy substituted phenoxy derivatives afforded six compounds. Interactions and binding stability from the docking analysis and 20 ns molecular dynamic simulations confirmed the representative compounds to be suitable and plausible for PPARs pockets. The above-mentioned results demonstrated that the compounds may be used as reference for further optimization for enhanced PPARs activities and wide safety range.