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1.
Curr Neuropharmacol ; 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38549522

RESUMEN

BACKGROUND: Environmental exposures to non-biodegradable and biodegradable plastics are unavoidable. Microplastics (MPs) and nanoplastics (NPs) from the manufacturing of plastics (primary sources) and the degradation of plastic waste (secondary sources) can enter the food chain directly or indirectly and, passing biological barriers, could target both the brain and the gonads. Hence, the worldwide diffusion of environmental plastic contamination (PLASTAMINATION) in daily life may represent a possible and potentially serious risk to human health. OBJECTIVE: This review provides an overview of the effects of non-biodegradable and the more recently introduced biodegradable MPs and NPs on the brain and brain-dependent reproductive functions, summarizing the molecular mechanisms and outcomes on nervous and reproductive organs. Data from in vitro, ex vivo, non-mammalian and mammalian animal models and epidemiological studies have been reviewed and discussed. RESULTS: MPs and NPs from non-biodegradable plastics affect organs, tissues and cells from sensitive systems such as the brain and reproductive organs. Both MPs and NPs induce oxidative stress, chronic inflammation, energy metabolism disorders, mitochondrial dysfunction and cytotoxicity, which in turn are responsible for neuroinflammation, dysregulation of synaptic functions, metabolic dysbiosis, poor gamete quality, and neuronal and reproductive toxicity. In spite of this mechanistic knowledge gained from studies of non-biodegradable plastics, relatively little is known about the adverse effects or molecular mechanisms of MPs and NPs from biodegradable plastics. CONCLUSION: The neurological and reproductive health risks of MPs/NPs exposure warrant serious consideration, and further studies on biodegradable plastics are recommended.

2.
Pharmaceutics ; 15(11)2023 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-38004530

RESUMEN

Plastics have changed human lives, finding a broad range of applications from packaging to medical devices. However, plastics can degrade into microscopic forms known as micro- and nanoplastics, which have raised concerns about their accumulation in the environment but mainly about the potential risk to human health. Recently, biodegradable plastic materials have been introduced on the market. These polymers are biodegradable but also bioresorbable and, indeed, are fundamental tools for drug formulations, thanks to their transient ability to pass through biological barriers and concentrate in specific tissues. However, this "other side" of bioplastics raises concerns about their toxic potential, in the form of micro- and nanoparticles, due to easier and faster tissue accumulation, with unknown long-term biological effects. This review aims to provide an update on bioplastic-based particles by analyzing the advantages and drawbacks of their potential use as components of innovative formulations for brain diseases. However, a critical analysis of the literature indicates the need for further studies to assess the safety of bioplastic micro- and nanoparticles despite they appear as promising tools for several nanomedicine applications.

3.
Clin Immunol ; 257: 109853, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-38013163

RESUMEN

Eosinophilic esophagitis (EoE) is increasingly diagnosed in patients with dysphagia. Type-2 immunity can induce EoE histopathology via non-IgE-dependent mechanisms, possibly involving IgG4 and IL-10. To elucidate the contribution of this response to EoE pathogenesis, we examined its association with clinical and histologic endpoints in adult EoE patients given a two-food elimination diet. IgG4- and IL-10-expressing cells were counted in esophageal biopsies and serum food-specific IgG4 measured at baseline and follow-up. Variables were correlated with histologic measures of disease activity. Patients exhibited significant reduction in esophageal eosinophilia and overall histology. A significant decrease in IL-10+-cell frequencies correlated with histologic changes. In contrast, a decline in serum and esophageal IgG4, while substantial, did not correlate with IL-10+-cell frequencies or histologic parameters. These results suggest a critical role of IL-10 in EoE pathogenesis. Conversely, IgG4 expression, while reflecting exposure to food antigens, is not obviously related to EoE histopathology or IL-10 expression.


Asunto(s)
Esofagitis Eosinofílica , Adulto , Humanos , Alérgenos , Biopsia , Esofagitis Eosinofílica/inmunología , Inmunoglobulina G , Interleucina-10
4.
Front Endocrinol (Lausanne) ; 14: 1269334, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37900144

RESUMEN

Introduction: Male reproduction is under the control of the hypothalamus-pituitary-gonadal (HPG) axis. The endocannabinoid system (ECS) and the kisspeptin system (KS) are two major signaling systems in the central and peripheral control of reproduction, but their possible interaction has been poorly investigated in mammals. This manuscript analyzes their possible reciprocal modulation in the control of the HPG axis. Materials and methods: Adolescent male rats were treated with kisspeptin-10 (Kp10) and endocannabinoid anandamide (AEA), the latter alone or in combination with the type 1 cannabinoid receptor (CB1) antagonist rimonabant (SR141716A). The hypothalamic KS system and GnRH expression, circulating sex steroids and kisspeptin (Kiss1) levels, and intratesticular KS and ECS were evaluated by immunohistochemical and molecular methods. Non-coding RNAs (i.e., miR145-5p, miR-132-3p, let7a-5p, let7b-5p) were also considered. Results: Circulating hormonal values were not significantly affected by Kp10 or AEA; in the hypothalamus, Kp10 significantly increased GnRH mRNA and aromatase Cyp19, Kiss1, and Kiss1 receptor (Kiss1R) proteins. By contrast, AEA treatment affected the hypothalamic KS at the protein levels, with opposite effects on the ligand and receptor, and SR141716A was capable of attenuating the AEA effects. Among the considered non-coding RNA, only the expression of miR145-5p was positively affected by AEA but not by Kp10 treatment. Localization of Kiss1+/Kiss1R+ neurons in the arcuate nucleus revealed an increase of Kiss1R-expressing neurons in Kp10- and AEA-treated animals associated with enlargement of the lateral ventricles in Kp10-treated animals. In the brain and testis, the selected non-coding RNA was differently modulated by Kp10 or AEA. Lastly, in the testis, AEA treatment affected the KS at the protein levels, whereas Kp10 affected the intragonadal levels of CB1 and FAAH, the main modulator of the AEA tone. Changes in pubertal transition-related miRNAs and the intratesticular distribution of Kiss1, Kiss1R, CB1, and CB2 following KP and AEA treatment corroborate the KS-ECS crosstalk also showing that the CB1 receptor is involved in this interplay. Conclusion: For the first time in mammals, we report the modulation of the KS in both the hypothalamus and testis by AEA and revealed the KP-dependent modulation of CB1 and FAAH in the testis. KP involvement in the progression of spermatogenesis is also suggested.


Asunto(s)
Kisspeptinas , MicroARNs , Masculino , Ratas , Animales , Kisspeptinas/genética , Kisspeptinas/metabolismo , Receptores de Kisspeptina-1/genética , Endocannabinoides/farmacología , Endocannabinoides/metabolismo , Rimonabant/metabolismo , Rimonabant/farmacología , Hipotálamo/metabolismo , Hormona Liberadora de Gonadotropina/metabolismo , Mamíferos/metabolismo , Reproducción , ARN no Traducido/metabolismo , MicroARNs/metabolismo
5.
Molecules ; 28(12)2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37375406

RESUMEN

Human malignant melanoma cells from lymph node metastatic site (MeWo) were selected for testing several synthesized and purified silver(I) and gold(I) complexes stabilized by unsymmetrically substituted N-heterocyclic carbene (NHC) ligands, called L20 (N-methyl, N'-[2-hydroxy ethylphenyl]imidazol-2-ylide) and M1 (4,5-dichloro, N-methyl, N'-[2-hydroxy ethylphenyl]imidazol-2-ylide), having halogenide (Cl- or I-) or aminoacyl (Gly=N-(tert-Butoxycarbonyl)glycinate or Phe=(S)-N-(tert-Butoxycarbonyl)phenylalaninate) counterion. For AgL20, AuL20, AgM1 and AuM1, the Half-Maximal Inhibitory Concentration (IC50) values were measured, and all complexes seemed to reduce cell viability more effectively than Cisplatin, selected as control. The complex named AuM1 was the most active just after 8 h of treatment at 5 µM, identified as effective growth inhibition concentration. AuM1 also showed a linear dose and time-dependent effect. Moreover, AuM1 and AgM1 modified the phosphorylation levels of proteins associated with DNA lesions (H2AX) and cell cycle progression (ERK). Further screening of complex aminoacyl derivatives indicated that the most powerful were those indicated with the acronyms: GlyAg, PheAg, AgL20Gly, AgM1Gly, AuM1Gly, AgL20Phe, AgM1Phe, AuM1Phe. Indeed, the presence of Boc-Glycine (Gly) and Boc-L-Phenylalanine (Phe) showed an improved efficacy of Ag main complexes, as well as that of AuM1 derivatives. Selectivity was further checked on a non-cancerous cell line, a spontaneously transformed aneuploid immortal keratinocyte from adult human skin (HaCaT). In such a case, AuM1 and PheAg complexes resulted as the most selective allowing HaCaT viability at 70 and 40%, respectively, after 48 h of treatment at 5 µM. The same complexes tested on 3D MeWo static culture induced partial spheroid disaggregation after 24 h of culture, with almost half of the cells dead.


Asunto(s)
Antineoplásicos , Complejos de Coordinación , Compuestos Heterocíclicos , Melanoma , Humanos , Complejos de Coordinación/química , Estructura Molecular , Antineoplásicos/farmacología , Antineoplásicos/química , Cisplatino/farmacología , Metano/química , Melanoma/tratamiento farmacológico , Compuestos Heterocíclicos/química , Línea Celular Tumoral
6.
Artículo en Inglés | MEDLINE | ID: mdl-36900934

RESUMEN

INTRODUCTION: Few studies have focused on the long-term effects of the COVID-19 pandemic on mental health. The objective of our work was to evaluate the changes in emotional and behavioral symptoms in patients with neuropsychiatric disorders and the impact on parenting stress 1 year after the first national lockdown. METHODS: We enrolled 369 patients aged 1.5-18 years of age referred to the Child and Adolescent Neuropsychiatry Unit of the University Hospital of Salerno (Italy) by their parents. We asked their parents to complete two standardized questionnaires for the assessment of emotional/behavioral symptoms (Child Behavior CheckList, CBCL) and parental stress (Parenting Stress Index, PSI) prior to the pandemic (Time 0), during the first national lockdown (Time 1) and after 1 year (Time 2), and we monitored the changes in symptoms over time. RESULTS: After 1 year from the start of the first national lockdown, we found a significant increase of internalizing problems, anxiety, depression, somatization, and social and oppositional-defiant problems in older children (6-18 years), and a significant increase of somatization, anxiety problems, and sleep problems in younger children (1.5-5 years). We also observed a significant relationship between emotional/behavioral symptoms and parental stress. CONCLUSION: Our study showed that parental stress levels increased compared to the pre-pandemic months and continues to persist over time, while internalizing symptoms of children and adolescents showed a significant worsening during 1 year follow-up from the first COVID-19 lockdown.


Asunto(s)
COVID-19 , Humanos , Niño , Adolescente , Lactante , Preescolar , Pandemias , Estudios de Seguimiento , Control de Enfermedades Transmisibles , Responsabilidad Parental/psicología
7.
Cancers (Basel) ; 14(12)2022 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-35740587

RESUMEN

BACKGROUND: Mucosal-associated invariant T (MAIT) cells are a subset of unconventional T lymphocytes expressing a semi-invariant α/ß T-cell receptor (TCR). The physiological functions of these cells, which are particularly abundant in normal liver and mucosal sites, have become clear only in recent years, but their role in most human diseases is still unknown. Since the cellular origin and etiopathogenesis of most T-lymphomas are still elusive, we decided to explore the presence of MAIT cells in biopsies from these neoplasms. METHODS: Sixteen biopsies obtained from patients with a T-cell lymphoma diagnosis were analyzed via immunofluorescence staining using an anti-Vα7.2 antibody and the MR1-antigen tetramer. Positive cases were subjected to a polymerase chain reaction for the detection of Vα7.2-Jα33, Vα7.2-Jα20, or Vα7.2-Jα12 rearrangements, followed by sequencing of the CDR3α region. RESULTS: CD3+/Vα7.2+ and CD3+/MR1-Ag-tetramer+ cells were found in 4 of 16 samples analyzed. The identification of specific TCR rearrangements confirmed the presence of these cells in all four samples. PCR and sequencing results documented the presence of multiple clones of MAIT cells in each positive sample. CONCLUSIONS: MAIT cells are frequently found in T-cell lymphomas. More in-depth studies and a larger number of samples are needed to better clarify the contribution of MAIT cells to this rare neoplasm.

8.
Genes (Basel) ; 13(2)2022 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-35205340

RESUMEN

The hypothalamus-pituitary-testis axis controls the production of spermatozoa, and the kisspeptin system, comprising Kiss1 and Kiss1 receptor (Kiss1R), is the main central gatekeeper. The activity of the kisspeptin system also occurs in testis and spermatozoa, but currently the need of peripheral kisspeptin to produce gametes is not fully understood. Hence, we characterized kisspeptin system in rat spermatozoa and epididymis caput and cauda and analyzed the possible presence of Kiss1 in the epididymal fluid. The presence of Kiss1 and Kiss1R in spermatozoa collected from epididymis caput and cauda was evaluated by Western blot; significant high Kiss1 levels in the caput (p < 0.001 vs. cauda) and constant levels of Kiss1R proteins were observed. Immunofluorescence analysis revealed that the localization of Kiss1R in sperm head shifts from the posterior region in the epididymis caput to perforatorium in the epididymis cauda. In spermatozoa-free epididymis, Western blot revealed higher expression of Kiss1 and Kiss1R in caput (p < 0.05 vs. cauda). Moreover, immunohistochemistry revealed that Kiss1 and Kiss1R proteins were mainly localized in the secretory epithelial cell types and in contractile myoid cells, respectively. Finally, both dot blot and Elisa revealed the presence of Kiss1 in the epididymal fluid collected from epididymis cauda and caput, indicating that rat epididymis and spermatozoa possess a complete kisspeptin system. In conclusion, we reported for the first time in rodents Kiss1R trafficking in spermatozoa during the epididymis transit and Kiss1 measure in the epididymal fluid, thus suggesting a possible role for the system in spermatozoa maturation and storage within the epididymis.


Asunto(s)
Epidídimo , Kisspeptinas , Animales , Epidídimo/metabolismo , Kisspeptinas/genética , Kisspeptinas/metabolismo , Masculino , Proteínas/metabolismo , Ratas , Receptores de Kisspeptina-1/genética , Receptores de Kisspeptina-1/metabolismo , Maduración del Esperma/genética , Espermatozoides/metabolismo
9.
Chemosphere ; 254: 126819, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32334263

RESUMEN

Bisphenol A (BPA) is a synthetic xenoestrogen diffused worldwide. Humans are chronically exposed to low doses of BPA from food and drinks, thus BPA accumulates in tissues posing human health risk. In this study, we investigated the effects of BPA on peripheral blood mononuclear cells (PBMC) from human healthy donors, and in glia and microglia of rat offspring at postnatal day 17 (17PND) from pregnant females who received BPA soon after coupling and during lactation and weaning. Results indicated that BPA affected Phytoemagglutinin (PHA) stimulated PBMC proliferation causing an S-phase cell cycle accumulation at nanomolar concentrations while BPA was almost ineffective in resting PBMC. Furthermore, BPA induced chromosome aberrations and the appearance of shattered cells characterized by high number of fragmented and pulverized chromosomes, suggesting that the compound could cause a massive genomic rearrangement by inducing catastrophic events. The BPA-induced DNA damage was observed mainly in TCD4+ and TCD8+ subsets of T lymphocytes and was mediated by the increase of ERK1/2 phosphorylation, p21/Waf1 and PARP1 protein expression. Intriguingly, we observed for the first time that BPA-induced effects were associated to a sex specific modulation of ERα and ERß in human PBMC. Immunofluorescence analysis of rat hippocampus corroborated in vitro findings showing that BPA induced É£H2AX phosphorylation in microglia and astrocytosis by decreasing ERα expression within the dentate gyrus. Overall these results suggest that BPA can alter immune surveillance functions at both peripheral and central level with a potential risk for cancer, neuroinflammation and neurodegeneration.


Asunto(s)
Compuestos de Bencidrilo/toxicidad , Daño del ADN , Fenoles/toxicidad , Animales , Ciclo Celular , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Femenino , Humanos , Leucocitos Mononucleares/efectos de los fármacos , Masculino , Proteína Quinasa 3 Activada por Mitógenos , Fosforilación , Embarazo , Ratas
11.
J Phys Chem B ; 122(2): 910-918, 2018 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-29072463

RESUMEN

Specific ion effects of the large halide anions have been shown to moderate anion adsorption to the air-water interface (AWI), but little quantitative attention has been paid to the behavior of alkali cations. Here we investigate the concentration and local distribution of sodium (Na+) at the AWI in dilute (<1 M) aqueous solutions of NaCl, NaBr, and NaI using a combination of molecular dynamics (MD) and SESSA simulations, and liquid jet ambient pressure photoelectron spectroscopy measurements. We use SESSA to simulate Na 2p photoelectron intensities on the basis of the atom density profiles obtained from MD simulations, and we compare the simulation results with photoelectron spectroscopy experiments to evaluate the performance of a nonpolarizable force field model versus that of an induced dipole polarizable one. Our results show that the nonpolarizable force model developed by Horinek and co-workers (Chem. Phys. Lett. 2009, 479, 173-183) accurately predicts the local concentration and distribution of Na+ near the AWI for all three electrolytes, whereas the polarizable model does not. To our knowledge, this is the first interface-specific spectroscopic validation of a MD force field. The molecular origins of the unique Na+ distributions for the three electrolytes are analyzed on the basis of electrostatic arguments, and shown to arise from an indirect anion effect wherein the identity of the anion affects the strength of the attractive Na+-H2O electrostatic interaction. Finally, we use the photoelectron spectroscopy results to constrain the range of inelastic mean free paths (IMFPs) for the three electrolyte solutions used in the SESSA simulations that are able to reproduce the experimental intensities. Our results suggest that earlier estimates of IMFPs for aqueous solutions are likely too high.

12.
Nat Commun ; 6: 8695, 2015 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-26522614

RESUMEN

The incidence and death rate of pancreatic ductal adenocarcinoma (PDAC) have increased in recent years, therefore the identification of novel targets for treatment is extremely important. Interactions between cancer and stromal cells are critically involved in tumour formation and development of metastasis. Here we report that PDAC cells secrete BAG3, which binds and activates macrophages, inducing their activation and the secretion of PDAC supporting factors. We also identify IFITM-2 as a BAG3 receptor and show that it signals through PI3K and the p38 MAPK pathways. Finally, we show that the use of an anti-BAG3 antibody results in reduced tumour growth and prevents metastasis formation in three different mouse models. In conclusion, we identify a paracrine loop involved in PDAC growth and metastatic spreading, and show that an anti-BAG3 antibody has therapeutic potential.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Reguladoras de la Apoptosis/metabolismo , Carcinoma Ductal Pancreático/metabolismo , Proliferación Celular , Macrófagos/citología , Neoplasias Pancreáticas/metabolismo , Células del Estroma/citología , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Proteínas Reguladoras de la Apoptosis/genética , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/fisiopatología , Femenino , Humanos , Macrófagos/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/fisiopatología , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Células del Estroma/metabolismo , Neoplasias Pancreáticas
15.
Front Biosci (Landmark Ed) ; 18(1): 133-44, 2013 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-23276914

RESUMEN

Breast cancer is a major cause of cancer death in women in the world. Triple-negative breast cancers, which accounts for 10-20% of all mammary tumours, are characterised by an aggressive phenotype, are often found in younger women and have been associated with poor prognosis. Obesity increases the risk for triple-negative breast cancer occurrence. Because triple-negative breast cancer patients are unresponsive to current targeted therapies and other treatment options are only partially effective, new pharmacological approaches are warranted. The obesity-linked adipokine, leptin, is a well known mitogen/survival factor in breast cancer cells and several studies have addressed the role of leptin in breast cancer pathogenesis and progression. Surprisingly, recent in vitro studies have shown that leptin enhances the anti-proliferative effects of cAMP elevation in triple-negative breast cancer cells by apoptosis induction. In the current review, we discuss on the role of cAMP as a growth suppressor and of leptin as a growth promoting factor in breast cancer cells and we will focus on the molecular pathways involved in the antiproliferative interaction between leptin and cAMP elevation. The rationale for the possible development of a simple, cheap and innovative approach for therapeutic intervention in triple-negative breast cancer, based on the use of cAMP elevating drugs at lower and tolerable doses, will be also discussed.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , AMP Cíclico/fisiología , Leptina/fisiología , Transducción de Señal/efectos de los fármacos , Neoplasias de la Mama/fisiopatología , Línea Celular Tumoral , AMP Cíclico/agonistas , AMP Cíclico/uso terapéutico , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Humanos , Leptina/uso terapéutico , Factor de Transcripción STAT3/metabolismo
16.
J Cell Physiol ; 228(1): 198-206, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22674530

RESUMEN

Osteosarcoma is the most common malignant primary bone tumor in children and adolescents. The clinical outcome for osteosarcoma remains discouraging despite aggressive surgery and intensive radiotherapy and chemotherapy regimens. Thus, novel therapeutic approaches are needed. Previously, we have shown that inorganic phosphate (Pi) inhibits proliferation and aggressiveness of human osteosarcoma U2OS cells identifying adenylate cyclase, beta3 integrin, Rap1, ERK1/2 as proteins whose expression and function are relevantly affected in response to Pi. In this study, we investigated whether Pi could affect chemosensitivity of osteosarcoma cells and the underlying molecular mechanisms. Here, we report that Pi inhibits proliferation of p53-wild type U2OS cells (and not of p53-null Saos and p53-mutant MG63 cells) by slowing-down cell cycle progression, without apoptosis occurrence. Interestingly, we found that Pi strongly enhances doxorubicin-induced cytotoxicity in U2OS, and not in Saos and MG63 cells, by apoptosis induction, as revealed by a marked increase of sub-G1 population, Bcl-2 downregulation, caspase-3 activation, and PARP cleavage. Remarkably, Pi/doxorubicin combination-induced cytotoxicity was accompanied by an increase of p53 protein levels and of p53 target genes mdm2, p21 and Bax, and was significantly reduced by the p53 inhibitor pifithrine-alpha. Moreover, the doxorubicin-induced cytotoxicity was associated with ERK1/2 pathway inhibition in response to Pi. Altogether, our data enforce the evidence of Pi as a novel signaling molecule capable of inhibiting ERK pathway and inducing sensitization to doxorubicin of osteosarcoma cells by p53-dependent apoptosis, implying that targeting Pi levels might represent a rational strategy for improving osteosarcoma therapy.


Asunto(s)
Antibióticos Antineoplásicos/uso terapéutico , Neoplasias Óseas/tratamiento farmacológico , Doxorrubicina/uso terapéutico , Osteosarcoma/tratamiento farmacológico , Fosfatos/uso terapéutico , Proteína p53 Supresora de Tumor/metabolismo , Antibióticos Antineoplásicos/administración & dosificación , Neoplasias Óseas/metabolismo , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Doxorrubicina/administración & dosificación , Quimioterapia Combinada , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Osteosarcoma/metabolismo , Fosfatos/administración & dosificación , Interferencia de ARN , ARN Interferente Pequeño , Proteína p53 Supresora de Tumor/genética
17.
Front Biosci (Elite Ed) ; 3(4): 1249-58, 2011 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-21622131

RESUMEN

Osteosarcoma is the most common malignant primary bone tumor in children and adolescents and is characterized by a high metastatic potential. Its clinical outcome remains discouraging despite aggressive treatments. Thus, novel therapeutic approaches are needed. Recent results indicate that inorganic phosphate (Pi) is capable of affecting specific signal transduction pathways and of acting as an active regulator of cell behaviour. Previously, we found that Pi inhibits proliferation of human osteosarcoma U2OS cells via an adenylate cyclase/cAMP mediated mechanism. Here, we report that upon Pi treatment, U2OS cells become extremely hard to dislodge with trypsin. The lack of sensitivity to the trypsin action was paralleled by relevant changes in integrin subunits expression and accompanied by an increase of cell adhesion in cell-matrix adhesion assays. Interestingly, exposure of U2OS cells to Pi results also in a strong activation and protein level up-regulation of Rap1 small GTPase and in an early increase followed by a sustained inhibition of Erk1/2 phosphorylation. Importantly, the Pi-induced increase of cell adhesion was enforced by a cAMP analogue which specifically activated Epac/Rap1 and insensitive to PKA and MEK1/2 inhibitors. Our results enforce the evidences of inorganic phosphate as a signalling molecule, identify beta3 integrin, Rap1, ERK1/2 as proteins whose expression and function are relevantly affected by Pi in osteosarcoma U2OS cells The clinical significance and potential therapeutic applications by our data will be discussed.


Asunto(s)
Osteosarcoma/patología , Fosfatos/farmacología , Adhesión Celular , Línea Celular Tumoral , Proliferación Celular , Humanos , Osteosarcoma/metabolismo
18.
J Phys Chem A ; 113(31): 8823-5, 2009 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-19591498

RESUMEN

There is a considerable controversy surrounding the nature of the Cl-/OH complex in aqueous solution, which appears as a byproduct of the irradiation of salt solutions in nuclear reactor operation, radioactive waste storage, medicine, and environmental problems. In this work, we report results of combined quantum mechanical molecular mechanics calculations of ground-state free-energy surfaces and absorption spectrum through the CCSDT level of theory that are consistent with the experimental data and suggest that hemibonded HOCl- species may indeed exist in bulk aqueous solution.

19.
J Phys Chem A ; 113(26): 7286-93, 2009 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-19438204

RESUMEN

Classical molecular dynamics simulations of aqueous solutions of sodium chloride and potassium fluoride at two different concentrations have been carried out using polarizable force fields and standard additive force fields (not including polarizability explicitly). We show that the presence of chloride ions at the air-solution interface, as predicted from the polarizable simulations of NaCl solutions, is reconcilable with the classical thermodynamics results of Gibbs absorption theory. We discuss the role of system size in the establishment of a bulklike region in which the ion densities have converged to the same value. We compare the results for NaCl solutions with those obtained for KF at two concentrations. We find that the computed surface tension and the surface excess follow the experimental trend for each salt solution. We have characterized the extent of adsorption by calculating the fraction of the solution surface area that is occupied by each ion. The analysis reveals that, as expected, in the KF solution neither the cation nor the anion is present on the surface, regardless of whether or not a polarizable force field is employed. On the other hand, in the NaCl solutions, chloride anions occupy the surface to an extent that is roughly proportional to their bulk concentration, but only when a polarizable model is used.

20.
Phys Chem Chem Phys ; 10(32): 4778-84, 2008 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-18688520

RESUMEN

X-Ray photoemission spectroscopy operating under ambient pressure conditions is used to probe ion distributions throughout the interfacial region of a free-flowing aqueous liquid micro-jet of 6 M potassium fluoride. Varying the energy of the ejected photoelectrons by carrying out experiments as a function of X-ray wavelength measures the composition of the aqueous-vapor interfacial region at various depths. The F(-) to K(+) atomic ratio is equal to unity throughout the interfacial region to a depth of 2 nm. The experimental ion profiles are compared with the results of a classical molecular dynamics simulation of a 6 M aqueous KF solution employing polarizable potentials. The experimental results are in qualitative agreement with the simulations when integrated over an exponentially decaying probe depth characteristic of an APPES experiment. First principles molecular dynamics simulations have been used to calculate the potential of mean force for moving a fluoride anion across the air-water interface. The results show that the fluoride anion is repelled from the interface, consistent with the depletion of F(-) at the interface revealed by the APPES experiment and polarizable force field-based molecular dynamics simulation. Together, the APPES and MD simulation data provide a detailed description of the aqueous-vapor interface of alkali fluoride systems. This work offers the first direct observation of the ion distribution at an aqueous potassium fluoride solution interface. The current experimental results are compared to those previously obtained for saturated solutions of KBr and KI to underscore the strong difference in surface propensity between soft/large and hard/small halide ions in aqueous solution.

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