RESUMEN
In this work, we implemented for the first time the cycloSaligenyl prodrug strategy to increase the bioavailability of fosmidomycin phosphate analogs in bacteria. Here, we report the synthesis of 34 cycloSaligenyl prodrugs of fosfoxacin and its derivatives. Among them, fifteen double prodrugs efficiently prevented the growth of the non-pathogenic, fast-growing Mycobacterium smegmatis.
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Profármacos , Citidina Monofosfato , Mycobacterium smegmatis , FosfatosRESUMEN
The retrograde transport inhibitor Retro-2 has a protective effect on cells and in mice against Shiga-like toxins and ricin. Retro-2 causes toxin accumulation in early endosomes and relocalization of the Golgi SNARE protein syntaxin-5 to the endoplasmic reticulum. The molecular mechanisms by which this is achieved remain unknown. Here, we show that Retro-2 targets the endoplasmic reticulum exit site component Sec16A, affecting anterograde transport of syntaxin-5 from the endoplasmic reticulum to the Golgi. The formation of canonical SNARE complexes involving syntaxin-5 is not affected in Retro-2-treated cells. By contrast, the interaction of syntaxin-5 with a newly discovered binding partner, the retrograde trafficking chaperone GPP130, is abolished, and we show that GPP130 must indeed bind to syntaxin-5 to drive Shiga toxin transport from the endosomes to the Golgi. We therefore identify Sec16A as a druggable target and provide evidence for a non-SNARE function for syntaxin-5 in interaction with GPP130.
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Benzamidas/metabolismo , Proteínas Qa-SNARE/metabolismo , Tiofenos/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Benzamidas/farmacología , Transporte Biológico , Retículo Endoplásmico/efectos de los fármacos , Retículo Endoplásmico/metabolismo , Endosomas/metabolismo , Aparato de Golgi/metabolismo , Células HeLa , Humanos , Transporte de Proteínas , Ricina/metabolismo , Toxina Shiga/metabolismo , Toxinas Shiga/metabolismo , Tiofenos/farmacología , Proteínas de Transporte Vesicular/fisiologíaRESUMEN
Hypertension is associated with excessive reactive oxygen species (ROS) production in vascular cells. Mitochondria undergo fusion and fission, a process playing a role in mitochondrial function. OPA1 is essential for mitochondrial fusion. Loss of OPA1 is associated with ROS production and cell dysfunction. We hypothesized that mitochondria fusion could reduce oxidative stress that defect in fusion would exacerbate hypertension. Using (a) Opa1 haploinsufficiency in isolated resistance arteries from Opa1+/- mice, (b) primary vascular cells from Opa1+/- mice, and (c) RNA interference experiments with siRNA against Opa1 in vascular cells, we investigated the role of mitochondria fusion in hypertension. In hypertension, Opa1 haploinsufficiency induced altered mitochondrial cristae structure both in vascular smooth muscle and endothelial cells but did not modify protein level of long and short forms of OPA1. In addition, we demonstrated an increase of mitochondrial ROS production, associated with a decrease of superoxide dismutase 1 protein expression. We also observed an increase of apoptosis in vascular cells and a decreased VSMCs proliferation. Blood pressure, vascular contractility, as well as endothelium-dependent and -independent relaxation were similar in Opa1+/- , WT, L-NAME-treated Opa1+/- and WT mice. Nevertheless, chronic NO-synthase inhibition with L-NAME induced a greater hypertension in Opa1+/- than in WT mice without compensatory arterial wall hypertrophy. This was associated with a stronger reduction in endothelium-dependent relaxation due to excessive ROS production. Our results highlight the protective role of mitochondria fusion in the vasculature during hypertension by limiting mitochondria ROS production.
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GTP Fosfohidrolasas/fisiología , Hipertensión/prevención & control , Dinámicas Mitocondriales , Sustancias Protectoras/administración & dosificación , Animales , Apoptosis , Inhibidores Enzimáticos/toxicidad , Hipertensión/inducido químicamente , Hipertensión/metabolismo , Hipertensión/patología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , NG-Nitroarginina Metil Éster/toxicidad , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
A recently developed inhibitor of retrograde transport, namely Retro-2.1, proved to be a potent and broad-spectrum lead in vitro against intracellular pathogens, such as toxins, parasites, intracellular bacteria and viruses. To circumvent its low aqueous solubility, a formulation in poly(ethylene glycol)-block-poly(D,L)lactide micelle nanoparticles was developed. This formulation enabled the study of the pharmacokinetic parameters of Retro-2.1 in mice following intravenous and intraperitoneal injections, revealing a short blood circulation time, with an elimination half-life of 5 and 6.7 h, respectively. To explain the poor pharmacokinetic parameters, the metabolic stability of Retro-2.1 was studied in vitro and in vivo, revealing fast cytochrome-P-450-mediated metabolism into a less potent hydroxylated analogue. Subcutaneous injection of Retro-2.1 formulated in a biocompatible and bioresorbable polymer-based thermosensitive hydrogel allowed for sustained release of the drug, with an elimination half-life of 19 h, and better control of its metabolism. This study provides a guideline on how to administer this promising lead in vivo in order to study its efficacy.
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Hidrogeles , Nanopartículas , Ratones , Animales , Preparaciones de Acción Retardada , Polietilenglicoles , Polímeros , TemperaturaRESUMEN
BACKGROUND/OBJECTIVES: Maternal obesity impacts vascular functions linked to metabolic disorders in offspring, leading to cardiovascular diseases during adulthood. Even if the relation between prenatal conditioning of cardiovascular diseases by maternal obesity and vascular function begins to be documented, little is known about resistance arteries. They are of particular interest because of their specific role in the regulation of local blood flow. Then our study aims to determine if maternal obesity can directly program fetal vascular dysfunction of resistance arteries, independently of metabolic disorders. METHODS: With a model of rats exposed in utero to mild maternal diet-induced obesity (OMO), we investigated third-order mesenteric arteries of 4-month old rats in absence of metabolic disorders. The methylation profile of these vessels was determined by reduced representation bisulfite sequencing (RRBS). Vascular structure and reactivity were investigated using histomorphometry analysis and wire-myography. The metabolic function was evaluated by insulin and glucose tolerance tests, plasma lipid profile, and adipose tissue analysis. RESULTS: At 4 months of age, small mesenteric arteries of OMO presented specific epigenetic modulations of matrix metalloproteinases (MMPs), collagens, and potassium channels genes in association with an outward remodeling and perturbations in the endothelium-dependent vasodilation pathways (greater contribution of EDHFs pathway in OMO males compared to control rats, and greater implication of PGI2 in OMO females compared to control rats). These vascular modifications were detected in absence of metabolic disorders. CONCLUSIONS: Our study reports a specific methylation profile of resistance arteries associated with vascular remodeling and vasodilation balance perturbations in offspring exposed in utero to maternal obesity, in absence of metabolic dysfunctions.
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Endotelio Vascular , Epigénesis Genética , Obesidad Materna/fisiopatología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Factores Sexuales , Resistencia Vascular , Animales , Colágeno/genética , Metilación de ADN , Dieta Alta en Grasa , Endotelio Vascular/fisiopatología , Femenino , Masculino , Metaloproteinasas de la Matriz/genética , Canales de Potasio/genética , Embarazo , Ratas , Ratas Sprague-DawleyRESUMEN
Dichlorodiphenyltrichloroethane (p,p'DDT) is an endocrine-disrupting chemical (EDC). Several studies showed an association between p,p'DDT exposure and reprotoxic effects. We showed that p,p'DDT was a positive allosteric modulator of human follitropin receptor (FSHR). In contrast, we demonstrated that p,p'DDT decreased the cyclic AMP (cAMP) production induced by human choriogonadotropin (hCG). This study evaluated further the effects of p,p'DDT on Gs-, ß-arrestin 2- and steroidogenesis pathways induced by hCG or luteinizing hormone (LH). We used Chinese hamster ovary cells line stably expressing hCG/LHR. The effects of 10-100 µM p,p'DDT on cAMP production and on ß-arrestin 2 recruitment were measured using bioluminescence and time-resolved resonance energy transfer technology. The impact of 100 µM of p,p'DDT on steroid secretion was analysed in murine Leydig tumor cell line (mLTC-1). In cAMP assays, 100 µM p,p'DDT increased the EC50 by more than 300% and reduced the maximum response of the hCG/LHR to hCG and hLH by 30%. This inhibitory effect was also found in human granulosa cells line and in mLTC-1 cells. Likewise, 100 µM p,p'DDT decreased the hCG- and hLH-promoted ß-arrestin 2 recruitment down to 14.2 and 26.6%, respectively. Moreover, 100 µM p,p'DDT decreased by 30 and 47% the progesterone secretion induced by hCG or hLH, respectively, without affecting testosterone secretion. This negative effect of p,p'DDT was independent of cytotoxicity. p,p'DDT acted as a negative allosteric modulator of the hCG/LHR signalling. This emphasizes the importance of analyzing all receptor-downstream pathways to fully understand the deleterious effects of EDC on human health.
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DDT/toxicidad , Disruptores Endocrinos/toxicidad , Animales , Células CHO , Gonadotropina Coriónica , Cricetinae , Cricetulus , AMP Cíclico , Femenino , Humanos , Células Intersticiales del Testículo , Hormona Luteinizante/metabolismo , Masculino , Ratones , Receptores Acoplados a Proteínas G , Receptores de HL , Transducción de SeñalRESUMEN
Differentiated thyroid cancers are more frequent in women than in men. These different frequencies may depend on differences in patient's behavior and in thyroid investigations. However, an impact on sexual hormones is likely, although this has been insufficiently elucidated. Estrogens may increase the production of mutagenic molecules in the thyroid cell and favor the proliferation and invasion of tumoral cells by regulating both the thyrocyte enzymatic machinery and the inflammatory process associated with tumor growth. On the other hand, the worse prognosis of thyroid cancer associated with the male gender is poorly explained.
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Hormonas Esteroides Gonadales/metabolismo , Razón de Masculinidad , Neoplasias de la Tiroides/epidemiología , Estrógenos/metabolismo , Femenino , Humanos , Masculino , Pronóstico , Receptores de Estrógenos/metabolismo , Factores Sexuales , Glándula Tiroides/patología , Neoplasias de la Tiroides/mortalidad , Neoplasias de la Tiroides/patologíaRESUMEN
(1) Background: Chronic increases in blood flow, as in cardiovascular diseases, induce outward arterial remodeling. Thrombospondin-1 (TSP-1) is known to interact with matrix proteins and immune cell-surface receptors, but its contribution to flow-mediated remodeling in the microcirculation remains unknown. (2) Methods: Mesenteric arteries were ligated in vivo to generate high- (HF) and normal-flow (NF) arteries in wild-type (WT) and TSP-1-deleted mice (TSP-1-/-). After 7 days, arteries were isolated and studied ex vivo. (3) Results: Chronic increases in blood flow induced outward remodeling in WT mice (increasing diameter from 221 ± 10 to 280 ± 10 µm with 75 mmHg intraluminal pressure) without significant effect in TSP-1-/- (296 ± 18 to 303 ± 14 µm), neutropenic or adoptive bone marrow transfer mice. Four days after ligature, pro inflammatory gene expression levels (CD68, Cox2, Gp91phox, p47phox and p22phox) increased in WT HF arteries but not in TSP-1-/- mice. Perivascular neutrophil accumulation at day 4 was significantly lower in TSP-1-/- than in WT mice. (4) Conclusions: TSP-1 origin is important; indeed, circulating TSP-1 participates in vasodilation, whereas both circulating and tissue TSP-1 are involved in arterial wall thickness and diameter expansion.
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Endotelio Vascular/metabolismo , Arterias Mesentéricas/fisiología , Trombospondina 1/metabolismo , Animales , Arterias Mesentéricas/metabolismo , Ratones , Ratones Noqueados , Microcirculación , Modelos Animales , Flujo Sanguíneo Regional , Trombospondina 1/genética , VasodilataciónRESUMEN
Three α,α-difluorophosphonate derivatives of fosmidomycin were synthesized from diethyl 1,1-difluorobut-3-enylphosphonate and were evaluated on Escherichia coli. Two of them are among the best 1-deoxy-d-xylulose 5-phosphate reductoisomerase inhibitors, with IC50 in the nM range, much better than fosmidomycin, the reference compound. They also showed an enhanced antimicrobial activity against E. coli on Petri dishes in comparison with the corresponding phosphates and the non-fluorinated phosphonate.
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Antibacterianos/farmacología , Fosfomicina/análogos & derivados , Ácidos Hidroxámicos/farmacología , Isomerasas Aldosa-Cetosa/antagonistas & inhibidores , Isomerasas Aldosa-Cetosa/metabolismo , Farmacorresistencia Bacteriana/efectos de los fármacos , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Fosfomicina/síntesis química , Fosfomicina/química , Fosfomicina/farmacología , Pruebas de Sensibilidad MicrobianaRESUMEN
Aryl phosphoramidate prodrugs of fosfoxacin derivatives 15a-b and 8a-b were synthesized and investigated for their ability to target bacteria. No growth inhibition was observed neither for Mycobacterium smegmatis nor for Escherichia coli on solid medium, demonstrating the absence of release of the active compounds in the bacterial cells. Investigation of the stability of the prodrugs and their multienzymatic cleavage in abiotic and biotic conditions showed that the use of aryl phosphoramidate prodrug approach to deliver non-nucleotides compounds is not obvious and might not be appropriate for an antimicrobial drug.
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Amidas/síntesis química , Citidina Monofosfato/análogos & derivados , Ácidos Fosfóricos/síntesis química , Profármacos/síntesis química , Amidas/química , Citidina Monofosfato/síntesis química , Citidina Monofosfato/química , Estructura Molecular , Ácidos Fosfóricos/química , Profármacos/químicaRESUMEN
Hydroxamate analogs of fosfoxacin, the phosphate homolog of fosmidomycin, have been synthesized and their activity tested on Escherichia coli and Mycobacterium smegmatis DXRs. Except for compound 4b, the IC50 values of phosphate derivatives are approximately 10-fold higher than those of the corresponding phosphonates. Although their inhibitory activity on Escherichia coli DXR is less efficient than their phosphonate analogs, we report the ability of phosphate compounds to inhibit the growth of Escherichia coli. This work points out that the uptake of fosfoxacin and its analogs is taking place via the GlpT and UhpT transporters. As expected, these compounds are inefficient to inhibit the growth of M. smegmatis growth inhibition probably due to a lack of uptake.
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Isomerasas Aldosa-Cetosa/antagonistas & inhibidores , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/farmacología , Escherichia coli/enzimología , Fosfomicina/análogos & derivados , Mycobacterium smegmatis/enzimología , Fosfatos/farmacología , Isomerasas Aldosa-Cetosa/metabolismo , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/química , Fosfomicina/síntesis química , Fosfomicina/química , Fosfomicina/farmacología , Estructura Molecular , Fosfatos/química , Relación Estructura-ActividadRESUMEN
Iron is an essential nutriment for almost all organisms, but this metal is poorly bioavailable. During infection, bacteria access iron from the host by importing either iron or heme. Pseudomonas aeruginosa, a gram-negative pathogen, secretes two siderophores, pyoverdine (PVD) and pyochelin (PCH), to access iron and is also able to use many siderophores produced by other microorganisms (called xenosiderophores). To access heme, P. aeruginosa uses three distinct uptake pathways, named Has, Phu, and Hxu. We previously showed that P. aeruginosa expresses the Has and Phu heme uptake systems and the PVD- and PCH-dependent iron uptake pathways in iron-restricted growth conditions, using proteomic and RT-qPCR approaches. Here, using the same approaches, we show that physiological concentrations of hemin in the bacterial growth medium result in the repression of the expression of the proteins of the PVD- and PCH-dependent iron uptake pathways, leading to less production of these two siderophores. This indicates that the pathogen adapts its phenotype to use hemin as an iron source rather than produce PVD and PCH to access iron. Moreover, the presence of both hemin and a xenosiderophore resulted in (i) the strong induction of the expression of the proteins of the added xenosiderophore uptake pathway, (ii) repression of the PVD- and PCH-dependent iron uptake pathways, and (iii) no effect on the expression levels of the Has, Phu, or Hxu systems, indicating that bacteria use both xenosiderophores and heme to access iron.
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Hierro , Pseudomonas aeruginosa , Hemina , Proteómica , SideróforosRESUMEN
BACKGROUND: Many studies link G protein-coupled receptors (GPCRs) to cancer. Some endocrine tumors are unresponsive to standard treatment and/or require long-term and poorly tolerated treatment. This study explored, by bioinformatics analysis, the tumoral profiling of the GPCR transcriptome to identify potential targets in these tumors aiming at drug repurposing. METHODS: We explored the GPCR differentially expressed genes (DEGs) from public datasets (Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas (TCGA)). The GEO datasets were available for two medullary thyroid cancers (MTCs), eighty-seven pheochromocytomas (PHEOs), sixty-one paragangliomas (PGLs), forty-seven pituitary adenomas and one-hundred-fifty adrenocortical cancers (ACCs). The TCGA dataset covered 92 ACCs. We identified GPCRs targeted by approved drugs from pharmacological databases (ChEMBL and DrugBank). RESULTS: The profiling of dysregulated GPCRs was tumor specific. In MTC, we found 14 GPCR DEGs, including an upregulation of the dopamine receptor (DRD2) and adenosine receptor (ADORA2B), which were the target of many drugs. In PGL, seven GPCR genes were downregulated, including vasopressin receptor (AVPR1A) and PTH receptor (PTH1R), which were targeted by approved drugs. In ACC, PTH1R was also downregulated in both the GEO and TCGA datasets and was the target of osteoporosis drugs. CONCLUSIONS: We highlight specific GPCR signatures across the major endocrine tumors. These data could help to identify new opportunities for drug repurposing.
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Biología Computacional , Neoplasias de la Tiroides , Perfilación de la Expresión Génica , Humanos , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Neoplasias de la Tiroides/genética , TranscriptomaRESUMEN
Enterobactin (ENT) is a tris-catechol siderophore used to acquire iron by multiple bacterial species. These ENT-dependent iron uptake systems have often been considered as potential gates in the bacterial envelope through which one can shuttle antibiotics (Trojan horse strategy). In practice, siderophore analogues containing catechol moieties have shown promise as vectors to which antibiotics may be attached. Bis- and tris-catechol vectors (BCVs and TCVs, respectively) were shown using structural biology and molecular modeling to mimic ENT binding to the outer membrane transporter PfeA in Pseudomonas aeruginosa. TCV but not BCV appears to cross the outer membrane via PfeA when linked to an antibiotic (linezolid). TCV is therefore a promising vector for Trojan horse strategies against P. aeruginosa, confirming the ENT-dependent iron uptake system as a gate to transport antibiotics into P. aeruginosa cells.
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Enterobactina , Oxazolidinonas , Antibacterianos/química , Catecoles/química , Catecoles/metabolismo , Enterobactina/metabolismo , Hierro/metabolismo , Proteínas de Transporte de Membrana/metabolismo , Oxazolidinonas/química , Pseudomonas aeruginosa/metabolismo , Sideróforos/metabolismoRESUMEN
CONTEXT: Radioiodine-refractory thyroid cancers have poor outcomes and limited therapeutic options (tyrosine kinase inhibitors) due to transient efficacy and toxicity of treatments. Therefore, combinatorial treatments with new therapeutic approaches are needed. Many studies link G protein-coupled receptors (GPCRs) to cancer cell biology. OBJECTIVE: To perform a specific atlas of GPCR expression in progressive and refractory thyroid cancer to identify potential targets among GPCRs aiming at drug repositioning. METHODS: We analyzed samples from tumor and normal thyroid tissues from 17 patients with refractory thyroid cancer (12 papillary thyroid cancers [PTCs] and 5 follicular thyroid cancers [FTCs]). We assessed GPCR mRNA expression using NanoString technology with a custom panel of 371 GPCRs. The data were compared with public repositories and pharmacological databases to identify eligible drugs. The analysis of prognostic value of genes was also performed with TCGA datasets. RESULTS: With our transcriptomic analysis, 4 receptors were found to be downregulated in FTC (VIPR1, ADGRL2/LPHN2, ADGRA3, and ADGRV1). In PTC, 24 receptors were deregulated, 7 of which were also identified by bioinformatics analyses of publicly available datasets on primary thyroid cancers (VIPR1, ADORA1, GPRC5B, P2RY8, GABBR2, CYSLTR2, and LPAR5). Among all the differentially expressed genes, 22 GPCRs are the target of approved drugs and some GPCRs are also associated with prognostic factors. DISCUSSION: For the first time, we performed GPCR mRNA expression profiling in progressive and refractory thyroid cancers. These findings provide an opportunity to identify potential therapeutic targets for drug repositioning and precision medicine in radioiodine-refractory thyroid cancer.
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Adenocarcinoma Folicular/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Cáncer Papilar Tiroideo/metabolismo , Neoplasias de la Tiroides/metabolismo , Adenocarcinoma Folicular/genética , Adenocarcinoma Folicular/patología , Adulto , Anciano , Femenino , Perfilación de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Medicina de Precisión , Receptores Acoplados a Proteínas G/genética , Estudios Retrospectivos , Cáncer Papilar Tiroideo/genética , Cáncer Papilar Tiroideo/patología , Glándula Tiroides/metabolismo , Glándula Tiroides/patología , Neoplasias de la Tiroides/genéticaRESUMEN
OBJECTIVE: Somatostatin receptor ligands (SRL) are useful to control central hyperthyroidism in patients with thyrotropin-secreting pituitary adenoma (TSH pituitary adenoma). The aim of this study was to describe the frequency of thyrotropin deficiency (TSH deficiency) in patients with TSH pituitary adenoma treated by SRL. DESIGN: Retrospective study. METHODS: Patients with central hyperthyroidism due to TSH pituitary adenoma treated by short or long-acting SRL were retrospectively included. TSH deficiency was defined by a low FT4 associated with non-elevated TSH concentrations during SRL therapy. We analysed the frequency of TSH deficiency and the characteristics of patients with or without TSH deficiency. RESULTS: Forty-six patients were included. SRL were used as the first-line therapy in 21 of 46 patients (46%). Central hyperthyroidism was controlled in 36 of 46 patients (78%). TSH deficiency appeared in 7 of 46 patients (15%) after a median time of 4 weeks (4-7) and for a median duration of 3 months (2.5-3). The TSH deficiency occurred after one to three injections of long-acting SRL used as first-line therapy in 6/7 cases. There were no differences in terms of clinical and hormonal features, size of adenomas or doses of SRL between patients with or without TSH deficiency. CONCLUSIONS: SRL can induce TSH deficiency in patients with central hyperthyroidism due to TSH pituitary adenoma. Thyrotropic function should be assessed before the first three injections of SRL in order to track TSH deficiency and reduce the frequency of injections when control of thyrotoxicosis rather than tumour reduction is the aim of the treatment.
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Adenoma/complicaciones , Hipertiroidismo/tratamiento farmacológico , Hipotiroidismo/inducido químicamente , Neoplasias Hipofisarias/complicaciones , Receptores de Somatostatina/uso terapéutico , Adenoma/metabolismo , Adulto , Femenino , Humanos , Hipertiroidismo/etiología , Ligandos , Masculino , Persona de Mediana Edad , Neoplasias Hipofisarias/metabolismo , Estudios Retrospectivos , Tirotropina/metabolismoRESUMEN
BACKGROUND: The presence of chemical pollutants in the environment can affect human health. Epidemiological and in vivo experimental studies reveal reprotoxic effects (undescended testis) of phthalates (diethylhexyl phthalate (DEHP), dibutyl phthalate (DBP)) and bisphenol A (BPA), resulting in particular of a decrease in INSL3 (Insulin-Like 3 peptide) production. This hormone is essential for normal testis development and acts on a G protein-coupled receptor: RXFP2. OBJECTIVES: The aim of this study was to evaluate the individual and combined impacts of DEHP, DBP, and BPA on human RXFP2 (hRXFP2) activity. METHODS: We used HEK293 cells transiently transfected with hRXFP2 and receptor activity was analyzed by measuring intracellular cAMP production. The mixture was established at concentrations reported in human amniotic fluid, for the three compounds. RESULTS: Individually, DEHP, DBP and BPA increased the response to INSL3 by 19.3 to 27.5%. This potentiating effect was specific for RXFP2, because it was absent in the cells which did not express this receptor. On the other hand, and interestingly, the mixture of the three compounds reduced significantly the response to INSL3 by 12%, and the observed effects were opposite to those predicted, suggesting an antagonist effect. DISCUSSION-CONCLUSION: Taken together, our results demonstrate for the first time that a mixture of phthalates and BPA present in human amniotic fluid disturbs the human RXFP2 function. Moreover, we demonstrate that mixture can produce potential antagonistic effects that are not displayed by the compounds, individually.
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Líquido Amniótico , Insulina , Compuestos de Bencidrilo/toxicidad , Células HEK293 , Humanos , Masculino , Fenoles , Receptores Acoplados a Proteínas G/efectos de los fármacosRESUMEN
Iron acquisition pathways have often been considered to be gateways for the uptake of antibiotics into bacteria. Bacteria excrete chelators, called siderophores, to access iron. Antibiotic molecules can be covalently attached to siderophores for their transport into pathogens during the iron-uptake process. P. aeruginosa produces two siderophores and is also able to use many siderophores produced by other bacteria. We investigated the phenotypic plasticity of iron-uptake pathway expression in an epithelial cell infection assay in the presence of two different siderophore-antibiotic conjugates, one with a hydroxamate siderophore and the second with a tris-catechol. Proteomic and RT-qPCR approaches showed that P. aeruginosa was able to sense the presence of both compounds in its environment and adapt the expression of its iron uptake pathways to access iron via them. Moreover, the catechol-type siderophore-antibiotic was clearly more efficient in inducing the expression of its corresponding transporter than the hydroxamate compound when both were simultaneously present. In parallel, the expression of the proteins of the two iron uptake pathways using siderophores produced by P. aeruginosa was significantly repressed in the presence of both conjugates. Altogether, the data indicate that catechol-type siderophores are more promising vectors for antibiotic vectorization using a Trojan-horse strategy.
RESUMEN
In the absence of crystal available for the full-length thyrotropin receptor, knowledge of its structure and functioning has benefitted from the identification and characterization of mutations in patients with various thyroid dysfunctions. The characterization of activating mutations has contributed to the elaboration of a model involving the extracellular domain of the receptor as an inverse tethered agonist which, upon binding of the ligand, relieves the transmembrane domain from an inhibiting interaction and activates it. The models derived from comparisons with other receptors, enriched with the information provided by the study of mutations, have proven useful for the design of small-molecule agonists and antagonists that may be used in the future to treat thyroid dysfunctions. In this review, extrathyroidal expression of the thyrotropin receptor is described, the role of which is still poorly defined.
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Receptores de Tirotropina/fisiología , Enfermedades de la Tiroides/etiología , Animales , Humanos , Mutación/fisiología , Receptores de Tirotropina/genética , Transducción de Señal/efectos de los fármacos , Enfermedades de la Tiroides/genética , Enfermedades de la Tiroides/metabolismo , Tirotropina/metabolismoRESUMEN
Aim/hypothesis:In utero exposure to maternal diabetes increases the risk of developing hypertension and cardiovascular disorders during adulthood. We have previously shown that this is associated with changes in vascular tone in favor of a vasoconstrictor profile, which is involved in the development of hypertension. This excessive constrictor tone has also a strong impact on vascular structure. Our objective was to study the impact of in utero exposure to maternal diabetes on vascular structure and remodeling induced by chronic changes in hemodynamic parameters. Methods and Results: We used an animal model of rats exposed in utero to maternal hyperglycemia (DMO), which developed hypertension at 6 months of age. At a pre-hypertensive stage (3 months of age), we observed deep structural modifications of the vascular wall without any hemodynamic perturbations. Indeed, in basal conditions, resistance arteries of DMO rats are smaller than those of control mother offspring (CMO) rats; in addition, large arteries like thoracic aorta of DMO rats have an increase of smooth muscle cell attachments to elastic lamellae. In an isolated perfused kidney, we also observed a leftward shift of the flow/pressure relationship, suggesting a rise in renal peripheral vascular resistance in DMO compared to CMO rats. In this context, we studied vascular remodeling in response to reduced blood flow by in vivo mesenteric arteries ligation. In DMO rats, inward remodeling induced by a chronic reduction in blood flow (1 or 3 weeks after ligation) did not occur by contrast to CMO rats in which arterial diameter decreased from 428 ± 17 µm to 331 ± 20 µm (at 125 mmHg, p = 0.001). In these animals, the transglutaminase 2 (TG2) pathway, essential for inward remodeling development in case of flow perturbations, was not activated in low-flow (LF) mesenteric arteries. Finally, in old hypertensive DMO rats (18 months of age), we were not able to detect a pressure-induced remodeling in thoracic aorta. Conclusions: Our results demonstrate for the first time that in utero exposure to maternal diabetes induces deep changes in the vascular structure. Indeed, the early narrowing of the microvasculature and the structural modifications of conductance arteries could be a pre-emptive adaptation to fetal programming of hypertension.