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1.
Pharmacol Res ; 206: 107296, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38971269

RESUMEN

The activity of sirtuin 1 (SIRT1, a member of the NAD+-dependent deacetylases family) decreases during aging as NAD+ levels naturally decline, thus increasing the risk of several age-associated diseases. Several sirtuin-activating compounds (STACs) have been developed to counteract the age-associated reduction in SIRT1 activity, and some of them are currently under development in clinical trials. STACs induce SIRT1 activation, either through allosteric activation of the enzyme in the presence of NAD+, or by increasing NAD+ levels by inhibiting its degradation or by supplying a key precursor in biosynthesis. In this study, we have identified (E)-2'-des-methyl sulindac analogues as a novel class of STACs that act also in the absence of NAD+, a peculiar behavior demonstrated through enzymatic and mass spectrometry experiments, both in vitro and in cell lines. The activation of the SIRT1 pathway was confirmed in vivo through gene expression and metabolomics analysis. Our data suggest that these compounds could serve as candidate leads for a novel therapeutic strategy aimed at addressing a key metabolic deficiency that may contribute to metabolic and age-associated diseases.


Asunto(s)
NAD , Sirtuina 1 , Sirtuina 1/metabolismo , NAD/metabolismo , Animales , Humanos , Activadores de Enzimas/farmacología , Línea Celular , Ratones , Masculino , Ratones Endogámicos C57BL , Descubrimiento de Drogas
2.
Int J Mol Sci ; 25(6)2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38542527

RESUMEN

Angiopoietin-like protein 3 (ANGPTL3) is a plasmatic protein that plays a crucial role in lipoprotein metabolism by inhibiting the lipoprotein lipase (LPL) and the endothelial lipase (EL) responsible for the hydrolysis of phospholipids on high-density lipoprotein (HDL). Interest in developing new pharmacological therapies aimed at inhibiting ANGPTL3 has been growing due to the hypolipidemic and antiatherogenic profile observed in its absence. The goal of this study was the in silico characterization of the interaction between ANGPTL3 and EL. Because of the lack of any structural information on both the trimeric coiled-coil N-terminal domain of ANGPTL3 and the EL homodimer as well as data regarding their interactions, the first step was to obtain the three-dimensional model of these two proteins. The models were then refined via molecular dynamics (MD) simulations and used to investigate the interaction mechanism. The analysis of interactions in different docking poses and their refinement via MD allowed the identification of three specific glutamates of ANGPTL3 that recognize a positively charged patch on the surface of EL. These ANGPTL3 key residues, i.e., Glu154, Glu157, and Glu160, could form a putative molecular recognition site for EL. This study paves the way for future investigations aimed at confirming the recognition site and at designing novel inhibitors of ANGPTL3.


Asunto(s)
Proteína 3 Similar a la Angiopoyetina , Lipasa , Proteínas Similares a la Angiopoyetina , Lipasa/metabolismo , Lipoproteína Lipasa/metabolismo , Lipoproteínas HDL/metabolismo , Fosfolípidos/metabolismo , Triglicéridos , Angiopoyetinas/metabolismo
3.
Proteins ; 91(5): 619-633, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36511838

RESUMEN

Riboflavin is an essential water-soluble vitamin that needs to be provided through the diet because of the conversion into flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), important cofactors in hundreds of flavoenzymes. The adsorption and distribution of riboflavin is mediated by transmembrane transporters of the SLC52 family, namely RFVT1-3, whose mutations are mainly associated with two diseases, MADD and the Brown-Vialetto-Van Laere syndrome. Interest in RFVTs as pharmacological targets has increased in the last few years due to their overexpression in several cancer cells, which can be exploited both by blocking the uptake of riboflavin into the cancerous cells, and by performing cancer targeted delivery of drugs with a high affinity for RFVTs. In this work, we propose three-dimensional structural models for all three human riboflavin transporters obtained by state-of-the-art artificial intelligence-based methods, which were then further refined with molecular dynamics simulations. Furthermore, two of the most notable mutations concerning RFVT2 and RFVT3 (W31S and N21S, respectively) were investigated studying the interactions between the wild-type and mutated transporters with riboflavin.


Asunto(s)
Inteligencia Artificial , Pérdida Auditiva Sensorineural , Humanos , Riboflavina/metabolismo , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Pérdida Auditiva Sensorineural/genética , Relación Estructura-Actividad , Mononucleótido de Flavina , Flavina-Adenina Dinucleótido/metabolismo
4.
Genet Med ; 25(11): 100922, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37403762

RESUMEN

PURPOSE: RPH3A encodes a protein involved in the stabilization of GluN2A subunit of N-methyl-D-aspartate (NMDA)-type glutamate receptors at the cell surface, forming a complex essential for synaptic plasticity and cognition. We investigated the effect of variants in RPH3A in patients with neurodevelopmental disorders. METHODS: By using trio-based exome sequencing, GeneMatcher, and screening of 100,000 Genomes Project data, we identified 6 heterozygous variants in RPH3A. In silico and in vitro models, including rat hippocampal neuronal cultures, have been used to characterize the effect of the variants. RESULTS: Four cases had a neurodevelopmental disorder with untreatable epileptic seizures [p.(Gln73His)dn; p.(Arg209Lys); p.(Thr450Ser)dn; p.(Gln508His)], and 2 cases [p.(Arg235Ser); p.(Asn618Ser)dn] showed high-functioning autism spectrum disorder. Using neuronal cultures, we demonstrated that p.(Thr450Ser) and p.(Asn618Ser) reduce the synaptic localization of GluN2A; p.(Thr450Ser) also increased the surface levels of GluN2A. Electrophysiological recordings showed increased GluN2A-dependent NMDA ionotropic glutamate receptor currents for both variants and alteration of postsynaptic calcium levels. Finally, expression of the Rph3AThr450Ser variant in neurons affected dendritic spine morphology. CONCLUSION: Overall, we provide evidence that missense gain-of-function variants in RPH3A increase GluN2A-containing NMDA ionotropic glutamate receptors at extrasynaptic sites, altering synaptic function and leading to a clinically variable neurodevelopmental presentation ranging from untreatable epilepsy to autism spectrum disorder.


Asunto(s)
Trastorno del Espectro Autista , Epilepsia , Animales , Humanos , Ratas , Trastorno del Espectro Autista/genética , Epilepsia/genética , Mutación Missense/genética , N-Metilaspartato/metabolismo , Neuronas/metabolismo , Rabfilina-3A
5.
Glycoconj J ; 40(6): 655-668, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38100017

RESUMEN

Since the 1980s, it has been known that the administration of ganglioside GM1 to cultured cells induced or enhanced neuronal differentiation. GM1 mechanism of action relies on its direct interaction and subsequent activation of the membrane tyrosine kinase receptor, TrkA, which naturally serves as NGF receptor. This process is mediated by the sole oligosaccharide portion of GM1, the pentasaccharide ß-Gal-(1-3)-ß-GalNAc-(1-4)-[α-Neu5Ac-(2-3)]-ß-Gal-(1-4)-ß-Glc. Here we detailed the minimum structural requirements of the oligosaccharide portion of GM1 for mediating the TrkA dependent neuritogenic processing. By in vitro and in silico biochemical approaches, we demonstrated that the minimal portion of GM1 required for the TrkA activation is the inner core of the ganglioside's oligosaccharide ß-Gal-(1-3)-ß-GalNAc-(1-4)-[α-Neu5Ac-(2-3)]-ß-Gal. The addition of a sialic acid residue at position 3 of the outer galactose of the GM1 oligosaccharide, which forms the oligosaccharide of GD1a, prevented the interaction with TrkA and the resulting neuritogenesis. On the contrary, the addition of a fucose residue at position 2 of the outer galactose, forming the Fucosyl-GM1 oligosaccharide, did not prevent the TrkA-mediated neuritogenesis.


Asunto(s)
Gangliósido G(M1) , Galactosa , Gangliósido G(M1)/química , Ácido N-Acetilneuramínico , Oligosacáridos/química
6.
Int J Mol Sci ; 24(3)2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36769028

RESUMEN

The fulfilment of the European "Farm to Fork" strategy requires a drastic reduction in the use of "at risk" synthetic pesticides; this exposes vulnerable agricultural sectors-among which is the European risiculture-to the lack of efficient means for the management of devastating diseases, thus endangering food security. Therefore, novel scaffolds need to be identified for the synthesis of new and more environmentally friendly fungicides. In the present work, we employed our previously developed 3D model of P. oryzae cytochrome bc1 (cyt bc1) complex to perform a high-throughput virtual screening of two commercially available compound libraries. Three chemotypes were selected, from which a small collection of differently substituted analogues was designed and synthesized. The compounds were tested as inhibitors of the cyt bc1 enzyme function and the mycelium growth of both strobilurin-sensitive (WT) and -resistant (RES) P. oryzae strains. This pipeline has permitted the identification of thirteen compounds active against the RES cyt bc1 and five compounds that inhibited the WT cyt bc1 function while inhibiting the fungal mycelia only minimally. Serendipitously, among the studied compounds we identified a new chemotype that is able to efficiently inhibit the mycelium growth of WT and RES strains by ca. 60%, without inhibiting the cyt bc1 enzymatic function, suggesting a different mechanism of action.


Asunto(s)
Ascomicetos , Fungicidas Industriales , Citocromos b/metabolismo , Ascomicetos/metabolismo , Fungicidas Industriales/farmacología , Estrobilurinas/farmacología , Complejo III de Transporte de Electrones
7.
Pharmacol Res ; 183: 106375, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35918045

RESUMEN

Toxic aggregates of α-synuclein (αsyn) are considered key drivers of Parkinson's disease (PD) pathology. In early PD, αsyn induces synaptic dysfunction also modulating the glutamatergic neurotransmission. However, a more detailed understanding of the molecular mechanisms underlying αsyn-triggered synaptic failure is required to design novel therapeutic interventions. Here, we described the role of Rabphilin-3A (Rph3A) as novel target to counteract αsyn-induced synaptic loss in PD. Rph3A is a synaptic protein interacting with αsyn and involved in stabilizing dendritic spines and in promoting the synaptic retention of NMDA-type glutamate receptors. We found that in vivo intrastriatal injection of αsyn-preformed fibrils in mice induces the early loss of striatal synapses associated with decreased synaptic levels of Rph3A and impaired Rph3A/NMDA receptors interaction. Modulating Rph3A striatal expression or interfering with the Rph3A/αsyn complex with a small molecule prevented dendritic spine loss and rescued associated early motor defects in αsyn-injected mice. Notably, the same experimental approaches prevented αsyn-induced synaptic loss in vitro in primary hippocampal neurons. Overall, these findings indicate that approaches aimed at restoring Rph3A synaptic functions can slow down the early synaptic detrimental effects of αsyn aggregates in PD.


Asunto(s)
Enfermedad de Parkinson , alfa-Sinucleína , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Ratones , Proteínas del Tejido Nervioso , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Proteínas de Transporte Vesicular/metabolismo , alfa-Sinucleína/metabolismo , Rabfilina-3A
8.
Regul Toxicol Pharmacol ; 131: 105146, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35219763

RESUMEN

On October 21-22, 2020 the HESI (Health and Environmental Sciences Institute) Protein Allergens, Toxins, and Bioinformatics Committee, and the Society of Toxicology Food Safety Specialty Section co-hosted a virtual workshop titled "From Protein Toxins to Applied Toxicological Testing". The workshop focused on the safety assessment of novel proteins contained in foods and feeds, was globally represented by over 200 stakeholder attendees, and featured contributions from experts in academia, government and non-government organizations, and agricultural biotechnology developers from the private sector. A range of topics relevant to novel protein safety were discussed, including: the state of protein toxin biology, modes and mechanisms of action, structures and activity, use of bioinformatic analyses to assess the safety of a protein, and ways to leverage computational biology with in silico approaches for protein toxin identification/characterization. Key outcomes of the workshop included the appreciation of the complexity of developing a definition for a protein toxin when viewed from the perspective of food and feed safety, confirming the need for a case-by-case hypothesis-driven interpretation of bioinformatic results that leverages additional metadata rather than an alignment threshold-driven interpretation, and agreement that a "toxin protein database" is not necessary, as the bioinformatic needs for toxin detection may be accomplished by existing databases such as Pfam and UniProtKB/Swiss-Prot. In this paper, a path forward is proposed.


Asunto(s)
Biología Computacional , Inocuidad de los Alimentos , Alérgenos/química , Alérgenos/toxicidad , Biotecnología/métodos , Bases de Datos de Proteínas
9.
Int J Mol Sci ; 23(14)2022 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-35886974

RESUMEN

NONO and SFPQ are involved in multiple nuclear processes (e.g., pre-mRNA splicing, DNA repair, and transcriptional regulation). These proteins, along with NEAT1, enable paraspeckle formation, thus promoting multiple myeloma cell survival. In this paper, we investigate NONO and SFPQ dimer stability, highlighting the hetero- and homodimer structural differences, and model their interactions with RNA, simulating their binding to a polyG probe mimicking NEAT1guanine-rich regions. We demonstrated in silico that NONO::SFPQ heterodimerization is a more favorable process than homodimer formation. We also show that NONO and SFPQ RRM2 subunits are primarily required for protein-protein interactions with the other DBHS protomer. Simulation of RNA binding to NONO and SFPQ, beside validating RRM1 RNP signature importance, highlighted the role of ß2 and ß4 strand residues for RNA specific recognition. Moreover, we demonstrated the role of the NOPS region and other protomer's RRM2 ß2/ß3 loop in strengthening the interaction with RNA. Our results, having deepened RNA and DBHS dimer interactions, could contribute to the design of small molecules to modulate the activity of these proteins. RNA-mimetics, able to selectively bind to NONO and/or SFPQ RNA-recognition site, could impair paraspeckle formation, thus representing a first step towards the discovery of drugs for multiple myeloma treatment.


Asunto(s)
Proteínas de Unión al ADN , Mieloma Múltiple , Factor de Empalme Asociado a PTB , ARN , Proteínas de Unión al ADN/metabolismo , Dimerización , Humanos , Mieloma Múltiple/genética , Mieloma Múltiple/metabolismo , Factor de Empalme Asociado a PTB/metabolismo , Subunidades de Proteína/metabolismo , ARN/metabolismo , Factores de Empalme de ARN/metabolismo , Proteínas de Unión al ARN/metabolismo
10.
Int J Mol Sci ; 24(1)2022 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-36613703

RESUMEN

GPR17, a G protein-coupled receptor, is a pivotal regulator of myelination. Its endogenous ligands trigger receptor desensitization and downregulation allowing oligodendrocyte terminal maturation. In addition to its endogenous agonists, GPR17 could be promiscuously activated by pro-inflammatory oxysterols and chemokines released at demyelinating lesions. Herein, the chemokine receptors CXCR2 and CXCR4 were selected to perform both in silico modelling and in vitro experiments to establish their structural and functional interactions with GPR17. The relative propensity of GPR17 and CXCR2 or CXCR4 to form homo- and hetero-dimers was assessed by homology modelling and molecular dynamics (MD) simulations, and co-immunoprecipitation and immunoenzymatic assay. The interaction between chemokine receptors and GPR17 was investigated by determining receptor-mediated modulation of intracellular cyclic adenosine monophosphate (cAMP). Our data show the GPR17 association with CXCR2 or CXCR4 and the negative regulation of these interactions by CXCR agonists or antagonists. Moreover, GPR17 and CXCR2 heterodimers can functionally influence each other. In contrast, CXCR4 can influence GPR17 functionality, but not vice versa. According to MD simulations, all the dimers reached conformational stability and negative formation energy, confirming the experimental observations. The cross-talk between these receptors could play a role in the development of the neuroinflammatory milieu associated with demyelinating events.


Asunto(s)
Receptores de Quimiocina , Receptores Acoplados a Proteínas G , Receptores Acoplados a Proteínas G/química , Transducción de Señal/fisiología , AMP Cíclico , Simulación de Dinámica Molecular
11.
J Lipid Res ; 62: 100006, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33518511

RESUMEN

Lecithin:cholesterol-acyl transferase (LCAT) plays a major role in cholesterol metabolism as it is the only extracellular enzyme able to esterify cholesterol. LCAT activity is required for lipoprotein remodeling and, most specifically, for the growth and maturation of HDLs. In fact, genetic alterations affecting LCAT functionality may cause a severe reduction in plasma levels of HDL-cholesterol with important clinical consequences. Although several hypotheses were formulated, the exact molecular recognition mechanism between LCAT and HDLs is still unknown. We employed a combination of structural bioinformatics procedures to deepen the insights into the HDL-LCAT interplay that promotes LCAT activation and cholesterol esterification. We have generated a data-driven model of reconstituted HDL (rHDL) and studied the dynamics of an assembled rHDL::LCAT supramolecular complex, pinpointing the conformational changes originating from the interaction between LCAT and apolipoprotein A-I (apoA-I) that are necessary for LCAT activation. Specifically, we propose a mechanism in which the anchoring of LCAT lid to apoA-I helices allows the formation of a hydrophobic hood that expands the LCAT active site and shields it from the solvent, allowing the enzyme to process large hydrophobic substrates.


Asunto(s)
Fosfatidilcolina-Esterol O-Aciltransferasa
12.
Int J Mol Sci ; 22(7)2021 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-33918510

RESUMEN

The increasing emergence of fungicide-resistant pathogens requires urgent solutions for crop disease management. Here, we describe a structural investigation of new fungicides obtained by combining strobilurin and succinate dehydrogenase inhibitor pharmacophores. We identified compounds endowed with very good activity against wild-type Pyricularia oryzae, combined in some cases with promising activity against strobilurin-resistant strains. The first three-dimensional model of P. oryzae cytochrome bc1 complex containing azoxystrobin as a ligand was developed. The model was validated with a set of commercially available strobilurins, and it well explains both the resistance mechanism to strobilurins mediated by the mutation G143A and the activity of metyltetraprole against strobilurin-resistant strains. The obtained results shed light on the key recognition determinants of strobilurin-like derivatives in the cytochrome bc1 active site and will guide the further rational design of new fungicides able to overcome resistance caused by G143A mutation in the rice blast pathogen.


Asunto(s)
Ascomicetos , Farmacorresistencia Fúngica , Fungicidas Industriales/síntesis química , Estrobilurinas/química , Pruebas de Sensibilidad Microbiana , Simulación del Acoplamiento Molecular , Succinato Deshidrogenasa/antagonistas & inhibidores
13.
Molecules ; 24(12)2019 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-31208066

RESUMEN

Monoacylglycerol lipase (MAGL) is a serine hydrolase that has a key regulatory role in controlling the levels of 2-arachidonoylglycerol (2-AG), the main signaling molecule in the endocannabinoid system. Identification of selective modulators of MAGL enables both to provide new tools for investigating pathophysiological roles of 2-AG, and to discover new lead compounds for drug design. The development of sensitive and reliable methods is crucial to evaluate this modulatory activity. In the current study, we report readily synthesized long-wavelength putative fluorogenic substrates with different acylic side chains to find a new probe for MAGL activity. 7-Hydroxyresorufinyl octanoate proved to be the best substrate thanks to the highest rate of hydrolysis and the best Km and Vmax values. In addition, in silico evaluation of substrates interaction with the active site of MAGL confirms octanoate resorufine derivative as the molecule of choice. The well-known MAGL inhibitors URB602 and methyl arachidonylfluorophosphonate (MAFP) were used for the assay validation. The assay was highly reproducible with an overall average Z' value of 0.86. The fast, sensitive and accurate method described in this study is suitable for low-cost high-throughput screening (HTS) of MAGL modulators and is a powerful new tool for studying MAGL activity.


Asunto(s)
Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Colorantes Fluorescentes , Ensayos Analíticos de Alto Rendimiento , Monoacilglicerol Lipasas/antagonistas & inhibidores , Relación Dosis-Respuesta a Droga , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Hidrólisis , Cinética , Conformación Molecular , Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Monoacilglicerol Lipasas/química , Reproducibilidad de los Resultados , Relación Estructura-Actividad
14.
Bioorg Med Chem ; 26(9): 2561-2572, 2018 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-29678535

RESUMEN

Monoacylglycerol lipase (MAGL) has an essential role in the catabolic pathway of the endocannabinoid 2-arachidonoylglycerol, which makes it a potential target for highly specific inhibitors for the treatment of a number of diseases. We designed and synthesized a series of carbamate analogues of URB602. We evaluated their inhibitory activity toward human MAGL in vitro both in cell culture and lysates. The target compounds exhibited moderate to excellent inhibitory activity against MAGL. The most promising compound 2b showed good inhibitory activity with IC50 value of 4.5 ±â€¯0.70 µM reducing MAGL activity to 82% of controls at 10 µM compared to 66% for the parent compound URB602. Interestingly, compounds 2b and 2c induce cell death through the inhibition of MAGL. Molecular modelling approaches and docking studies, used to investigate inhibitory profiles, indicated that trifluoromethyl substitutions of the aryl group and the benzene ring present at the oxygen side of the carbamate molecule had a significant impact on the activity.


Asunto(s)
Antineoplásicos/farmacología , Carbamatos/farmacología , Inhibidores Enzimáticos/farmacología , Monoacilglicerol Lipasas/antagonistas & inhibidores , Amidohidrolasas/antagonistas & inhibidores , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Apoptosis/efectos de los fármacos , Sitios de Unión , Compuestos de Bifenilo/síntesis química , Compuestos de Bifenilo/química , Compuestos de Bifenilo/farmacología , Carbamatos/síntesis química , Carbamatos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Pruebas de Enzimas , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Células HEK293 , Humanos , Ratones , Simulación del Acoplamiento Molecular , Estructura Molecular , Monoacilglicerol Lipasas/química , Relación Estructura-Actividad
15.
Arch Toxicol ; 92(12): 3471-3486, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30293151

RESUMEN

Consumers are exposed to pesticide residues and other food contaminants via the diet. Both can exert adverse effects on different target organs via the activation of nuclear receptor pathways. Hepatotoxic effects of the widely used triazole fungicide propiconazole (Pi) are generally attributed to the activation of the constitutive androstane receptor (CAR) or the pregnane X receptor (PXR). We now investigated the effects of Pi on the aryl hydrocarbon receptor (AHR) and possible mixture toxicity when Pi is present in combination with BbF, an AHR ligand. In silico docking simulations indicate that Pi can bind to human AHR. Subsequent dual luciferase reporter gene assays in human HepG2 cells showed that Pi activates the AHR in vitro. This concentration-dependent activation was confirmed by real-time RT-PCR analyses of the model AHR target genes CYP1A1 and CYP1A2 in human HepaRG and HepG2 cells. In addition, induction of CYP1A1 protein levels and enzyme activity were recorded. Similarly, increased mRNA expression and enzyme activity of Cyp1a1 and Cyp1a2 was observed in livers of rats treated with Pi for 28 days via the diet. Gene expression analysis in AHR-knockout HepaRG cells showed no induction of CYP1A1 and CYP1A2, whereas gene expression in CAR-, and PXR-knockout cells was induced. Finally, mixture effects of Pi and BbF were analyzed in human cell lines: modeling of concentration-response curves revealed concentration additivity. In conclusion, our results demonstrate that the triazole Pi is an activator of AHR in silico, in vitro and in vivo and causes additive effects with an established AHR ligand.


Asunto(s)
Fluorenos/toxicidad , Receptores de Hidrocarburo de Aril/efectos de los fármacos , Receptores Citoplasmáticos y Nucleares/efectos de los fármacos , Triazoles/toxicidad , Animales , Línea Celular , Simulación por Computador , Receptor de Androstano Constitutivo , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1A2/metabolismo , Relación Dosis-Respuesta a Droga , Fluorenos/administración & dosificación , Fungicidas Industriales/administración & dosificación , Fungicidas Industriales/toxicidad , Perfilación de la Expresión Génica/métodos , Técnicas de Inactivación de Genes , Genes Reporteros , Células Hep G2 , Humanos , Ligandos , Hígado/efectos de los fármacos , Simulación del Acoplamiento Molecular , Ratas , Ratas Wistar , Receptores de Hidrocarburo de Aril/genética , Receptores de Hidrocarburo de Aril/metabolismo , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Triazoles/administración & dosificación
16.
J Neurochem ; 143(6): 645-659, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28796418

RESUMEN

GM1 ganglioside (II3 NeuAc-Gg4 Cer) is known to promote neurite formation in neuroblastoma cells by activating TrkA-MAPK pathway. The molecular mechanism by which GM1 is involved in the neurodifferentiation process is still unknown, however, in vitro and in vivo evidences have suggested that the oligosaccharide portion of this ganglioside could be involved. Here, we report that, similarly to the entire GM1 molecule, its oligosaccharide II3 NeuAc-Gg4, rather than its ceramide (Cer) portion is responsible for the neurodifferentiation process by augmenting neurite elongation and increasing the neurofilament protein expression in murine neuroblastoma cells, Neuro2a. Conversely, asialo-GM1, GM2 and GM3 oligosaccharides are not effective in neurite elongation on Neuro2a cells, whereas the effect exerted by the Fuc-GM1 oligosaccharide (IV2 αFucII3 Neu5Ac-Gg4 ) is similar to that exerted by GM1 oligosaccharide. The neurotrophic properties of GM1 oligosaccharide are exerted by activating the TrkA receptor and the following phosphorylation cascade. By photolabeling experiments performed with a nitrophenylazide containing GM1 oligosaccharide, labeled with tritium, we showed a direct interaction between the GM1 oligosaccharide and the extracellular domain of TrkA receptor. Moreover, molecular docking analyses confirmed that GM1 oligosaccharide binds the TrkA-nerve growth factor complex leading to a binding free energy of approx. -11.5 kcal/mol, acting as a bridge able to increase and stabilize the TrkA-nerve growth factor molecular interactions.


Asunto(s)
Gangliósido G(M1)/metabolismo , Neuritas/metabolismo , Neuroblastoma , Receptor trkA/metabolismo , Animales , Diferenciación Celular/fisiología , Línea Celular , Gangliósido G(M1)/química , Ratones , Simulación del Acoplamiento Molecular , Oligosacáridos/química , Oligosacáridos/metabolismo , Transducción de Señal/fisiología
17.
Biochim Biophys Acta Gen Subj ; 1861(4): 727-736, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28088504

RESUMEN

BACKGROUND: LAT1 (SLC7A5) is the transport competent unit of the heterodimer formed with the glycoprotein CD98 (SLC3A2). It catalyzes antiport of His and some neutral amino acids such as Ile, Leu, Val, Cys, Met, Gln and Phe thus being involved in amino acid metabolism. Interestingly, LAT1 is over-expressed in many human cancers that are characterized by increased demand of amino acids. Therefore LAT1 was recently acknowledged as a novel target for cancer therapy. However, knowledge on molecular mechanism of LAT1 transport is still scarce. METHODS: Combined approaches of bioinformatics, site-directed mutagenesis, chemical modification, and transport assay in proteoliposomes, have been adopted to unravel dark sides of human LAT1 structure/function relationships. RESULTS: It has been demonstrated that residues F252, S342, C335 are crucial for substrate recognition and C407 plays a minor role. C335 and C407 cannot be targeted by SH reagents. The transporter has a preferential dimeric structure and catalyzes an antiport reaction which follows a simultaneous random mechanism. CONCLUSIONS: Critical residues of the substrate binding site of LAT1 have been probed. This site is not freely accessible by molecules other than substrate. Similarly to LeuT, K+ has some regulatory properties on LAT1. GENERAL SIGNIFICANCE: The collected data represent a solid basis for deciphering molecular mechanism underlying LAT1 function.


Asunto(s)
Sistemas de Transporte de Aminoácidos/metabolismo , Aminoácidos/metabolismo , Transportador de Aminoácidos Neutros Grandes 1/metabolismo , Transporte de Proteínas/fisiología , Secuencia de Aminoácidos , Humanos , Transporte Iónico/fisiología , Proteolípidos/metabolismo , Alineación de Secuencia
18.
Org Biomol Chem ; 14(13): 3404-8, 2016 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-26952764

RESUMEN

A recombinant ketoreductase from Pichia glucozyma (KRED1-Pglu) was used for the enantioselective reduction of various mono-substituted acetophenones. Reaction rates of meta- and para-derivatives were consistent with the electronic effects described by σ-Hammett coefficients; on the other hand, enantioselectivity was determined by an opposite orientation of the substrate in the binding pocket. Reduction of ortho-derivatives occurred only with substrates bearing substituents with low steric impact (i.e., F and CN). Reactivity was controlled by stereoelectronic features (C[double bond, length as m-dash]O length and charge, shape of LUMO frontier molecular orbitals), which can be theoretically calculated.


Asunto(s)
Acetofenonas/metabolismo , Oxidorreductasas de Alcohol/metabolismo , Pichia/enzimología , Acetofenonas/química , Oxidorreductasas de Alcohol/química , Electrones , Estructura Molecular , Oxidación-Reducción , Estereoisomerismo , Especificidad por Sustrato
19.
PLoS One ; 19(6): e0304512, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38829838

RESUMEN

The Organic Cation Transporter Novel 1 (OCTN1), also known as SLC22A4, is widely expressed in various human tissues, and involved in numerous physiological and pathological processes remains. It facilitates the transport of organic cations, zwitterions, with selectivity for positively charged solutes. Ergothioneine, an antioxidant compound, and acetylcholine (Ach) are among its substrates. Given the lack of experimentally solved structures of this protein, this study aimed at generating a reliable 3D model of OCTN1 to shed light on its substrate-binding preferences and the role of sodium in substrate recognition and transport. A chimeric model was built by grafting the large extracellular loop 1 (EL1) from an AlphaFold-generated model onto a homology model. Molecular dynamics simulations revealed domain-specific mobility, with EL1 exhibiting the highest impact on overall stability. Molecular docking simulations identified cytarabine and verapamil as highest affinity ligands, consistent with their known inhibitory effects on OCTN1. Furthermore, MM/GBSA analysis allowed the categorization of substrates into weak, good, and strong binders, with molecular weight strongly correlating with binding affinity to the recognition site. Key recognition residues, including Tyr211, Glu381, and Arg469, were identified through interaction analysis. Ach demonstrated a low interaction energy, supporting the hypothesis of its one-directional transport towards to outside of the membrane. Regarding the role of sodium, our model suggested the involvement of Glu381 in sodium binding. Molecular dynamics simulations of systems at increasing levels of Na+ concentrations revealed increased sodium occupancy around Glu381, supporting experimental data associating Na+ concentration to molecule transport. In conclusion, this study provides valuable insights into the 3D structure of OCTN1, its substrate-binding preferences, and the role of sodium in the recognition. These findings contribute to the understanding of OCTN1 involvement in various physiological and pathological processes and may have implications for drug development and disease management.


Asunto(s)
Simulación del Acoplamiento Molecular , Simulación de Dinámica Molecular , Proteínas de Transporte de Catión Orgánico , Humanos , Proteínas de Transporte de Catión Orgánico/química , Proteínas de Transporte de Catión Orgánico/metabolismo , Proteínas de Transporte de Catión Orgánico/genética , Simportadores/química , Simportadores/metabolismo , Sitios de Unión , Unión Proteica , Ergotioneína/química , Ergotioneína/metabolismo , Sodio/metabolismo , Sodio/química , Simulación por Computador , Acetilcolina/metabolismo , Acetilcolina/química , Ligandos
20.
Sci Rep ; 13(1): 1343, 2023 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-36823210

RESUMEN

Stature is a biological trait directly determined by the interaction of genetic and environmental components. As such, it is often evaluated as an indicator for the reconstruction of skeletal biological profiles, past health, and social dynamics of human populations. Based on the analysis of 549 skeletons from the CAL (Collezione Antropologica LABANOF), a study of the diachronic trend of male and female adult stature in Milan (Italy) is being proposed here, covering a time span of about 2000 years, ranging from the Roman era to present-days. The skeletons, from necropolises dedicated to the less wealthy classes of Milanese society, were assigned to one of following five historical periods: Roman Era (first-fifth centuries AD), Early Middle Ages (sixth-tenth centuries AD), Late Middle Ages (eleventh-fifteenth centuries AD), Modern Era (sixteenth-eighteenth centuries AD) and Contemporary Era (nineteenth-twentieth centuries AD), and their stature was estimated according to the regression formulae of Trotter (1970). The collected data were then subjected to statistical analyses with ANOVA using R software. Although stature values showed an ample standard deviation in all periods, statistical analyses showed that stature did not significantly vary across historical periods in Milan for both sexes. This is one of the rare studies showing no diachronic changes in the trend of stature in Europe.


Asunto(s)
Estatura , Esqueleto , Adulto , Persona de Mediana Edad , Humanos , Masculino , Femenino , Europa (Continente) , Italia , Programas Informáticos
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