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1.
Int J Mol Sci ; 25(4)2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38396805

RESUMEN

Infection is a major contributor to the development of cancer, with more than 15% of new cancer diagnoses estimated to be caused by infection [...].


Asunto(s)
Toxinas Bacterianas , Neoplasias , Humanos , Toxinas Bacterianas/toxicidad
2.
J Cell Mol Med ; 27(10): 1315-1326, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37078409

RESUMEN

The bacterial product CNF1, through its action on the Rho GTPases, is emerging as a modulator of crucial signalling pathways involved in selected neurological diseases characterized by mitochondrial dysfunctions. Mitochondrial impairment has been hypothesized to have a key role in paramount mechanisms underlying Rett syndrome (RTT), a severe neurologic rare disorder. CNF1 has been already reported to have beneficial effects in mouse models of RTT. Using human RTT fibroblasts from four patients carrying different mutations, as a reliable disease-in-a-dish model, we explored the cellular and molecular mechanisms, which can underlie the CNF1-induced amelioration of RTT deficits. We found that CNF1 treatment modulates the Rho GTPases activity of RTT fibroblasts and induces a considerable re-organization of the actin cytoskeleton, mainly in stress fibres. Mitochondria of RTT fibroblasts show a hyperfused morphology and CNF1 decreases the mitochondrial mass leaving substantially unaltered the mitochondrial dynamic. From a functional perspective, CNF1 induces mitochondrial membrane potential depolarization and activation of AKT in RTT fibroblasts. Given that mitochondrial quality control is altered in RTT, our results are suggestive of a reactivation of the damaged mitochondria removal via mitophagy restoration. These effects can be at the basis of the beneficial effects of CNF1 in RTT.


Asunto(s)
Proteínas de Escherichia coli , Síndrome de Rett , Ratones , Animales , Humanos , Síndrome de Rett/tratamiento farmacológico , Síndrome de Rett/genética , Síndrome de Rett/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Proyectos Piloto , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/farmacología , Mitocondrias/metabolismo , Fibroblastos/metabolismo
3.
Anaerobe ; 82: 102757, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37380012

RESUMEN

OBJECTIVE: The aim of this study was to analyze enterotoxigenic Bacteroides fragilis (ETBF) isolates from colorectal biopsies of subjects with a histological analysis positive for colorectal cancer (CRC), pre-cancerous lesions (pre-CRC) or with a healthy intestinal tissue and to evaluate the environmental factors that may not only concur to CRC development but may also affect gut microbiota composition. METHODS: ETBF isolates were typed using the ERIC-PCR method, while PCR assays were performed to investigate the bft alleles, the B. fragilis pathogenicity island (BFPAI) region and the cepA, cfiA and cfxA genes. Susceptibility to antibiotics was tested using the agar dilution method. Environmental factors that could play a role in promoting intestinal dysbiosis were evaluated throughout a questionnaire administered to the subjects enrolled. RESULTS: Six different ERIC-PCR types were identified. The type denominated C in this study was the most prevalent, in particular among the biopsies of subjects with pre-CRC, while an isolate belonging to a different type, denominated F, was detected in a biopsy from a subject with CRC. All the ETBF isolates from pre-CRC or CRC subjects had a B. fragilis pathogenicity island (BFPAI) region pattern I, while those from healthy individuals showed also different patterns. Furthermore, 71% of isolates from subjects with pre-CRC or CRC were resistant to two or more classes of antibiotics vs 43% of isolates from healthy individuals. The B. fragilis toxin BFT1 was the most frequently detected in this study, confirming the constant circulation of this isoform strains in Italy. Interestingly, BFT1 was found in 86% of the ETBF isolates from patients with CRC or pre-CRC, while the BFT2 was prevalent among the ETBF isolates from healthy subjects. No substantial differences based on sex, age, tobacco and alcohol consumption were observed between healthy and non-healthy individuals included in this study, while most of the subjects with CRC or pre-CRC lesions were subjected to pharmacological therapy (71%) and showed a body mass index (BMI) that falls within the overweight range (86%). CONCLUSIONS: Our data suggest that some types of ETBF seem to better adapt and colonize the human gut and that the selective pressure exerted by factors related to lifestyle, such as pharmacological therapy and weight, could facilitate their persistence in the gut and their possible involvement in CRC development.


Asunto(s)
Infecciones Bacterianas , Toxinas Bacterianas , Infecciones por Bacteroides , Neoplasias Colorrectales , Humanos , Bacteroides fragilis , Toxinas Bacterianas/genética , Disbiosis , Metaloendopeptidasas/genética , Infecciones por Bacteroides/microbiología , Neoplasias Colorrectales/microbiología , Antibacterianos
4.
Cell Microbiol ; 22(2): e13138, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31698538

RESUMEN

Some toxigenic bacteria produce protein toxins with carcinogenic signatures, which either directly damage DNA or stimulate signalling pathways related to cancer. So far, however, only a few of them have been proved to favour the induction or progression of cancer. In this work, we report that the Rho-activating Escherichia coli protein toxin, cytotoxic necrotising factor 1 (CNF1), induces epithelial to mesenchymal transition (EMT) in intestinal epithelial cells. EMT is a crucial step in malignant tumour conversion and invasiveness. In the case of CNF1, it occurs by up-regulation of the transcription factors ZEB1 and Snail1, delocalisation of E-cadherin and ß-catenin, activation of the serine/threonine kinase mTOR, accelerated wound healing, and invasion. However, our results highlight that nontransformed epithelial cells entail the presence of inflammatory factors, in addition to CNF1, to acquire a mesenchymal-like behaviour. All this suggests that the surrounding microenvironment, as well as the cell type, dramatically influences the CNF1 ability to promote carcinogenic traits.


Asunto(s)
Toxinas Bacterianas/farmacología , Células Epiteliales/metabolismo , Transición Epitelial-Mesenquimal/efectos de los fármacos , Proteínas de Escherichia coli/farmacología , Escherichia coli/metabolismo , Factores de Transcripción de la Familia Snail/metabolismo , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/metabolismo , Antígenos CD/metabolismo , Cadherinas/metabolismo , Línea Celular , Células Epiteliales/patología , Humanos , Serina-Treonina Quinasas TOR/metabolismo , beta Catenina/metabolismo
5.
Int J Mol Sci ; 22(22)2021 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-34830494

RESUMEN

Cytotoxic necrotizing factor 1 (CNF1) is a bacterial virulence factor, the target of which is represented by Rho GTPases, small proteins involved in a huge number of crucial cellular processes. CNF1, due to its ability to modulate the activity of Rho GTPases, represents a widely used tool to unravel the role played by these regulatory proteins in different biological processes. In this review, we summarized the data available in the scientific literature concerning the observed in vitro effects induced by CNF1. An article search was performed on electronic bibliographic resources. Screenings were performed of titles, abstracts, and full-texts according to PRISMA guidelines, whereas eligibility criteria were defined for in vitro studies. We identified a total of 299 records by electronic article search and included 76 original peer-reviewed scientific articles reporting morphological or biochemical modifications induced in vitro by soluble CNF1, either recombinant or from pathogenic Escherichia coli extracts highly purified with chromatographic methods. Most of the described CNF1-induced effects on cultured cells are ascribable to the modulating activity of the toxin on Rho GTPases and the consequent effects on actin cytoskeleton organization. All in all, the present review could be a prospectus about the CNF1-induced effects on cultured cells reported so far.


Asunto(s)
Toxinas Bacterianas/genética , Infecciones por Escherichia coli/genética , Proteínas de Escherichia coli/genética , Escherichia coli/genética , Citoesqueleto de Actina/efectos de los fármacos , Citoesqueleto de Actina/genética , Toxinas Bacterianas/farmacología , Línea Celular , Enterotoxinas/genética , Enterotoxinas/farmacología , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/patología , Proteínas de Escherichia coli/farmacología , Humanos , Proteínas de Unión al GTP rho/genética
6.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-34201747

RESUMEN

Rett syndrome (RTT) is a rare neurological disorder caused by mutations in the X-linked MECP2 gene and a major cause of intellectual disability in females. No cure exists for RTT. We previously reported that the behavioural phenotype and brain mitochondria dysfunction are widely rescued by a single intracerebroventricular injection of the bacterial toxin CNF1 in a RTT mouse model carrying a truncating mutation of the MeCP2 gene (MeCP2-308 mice). Given the heterogeneity of MECP2 mutations in RTT patients, we tested the CNF1 therapeutic efficacy in a mouse model carrying a null mutation (MeCP2-Bird mice). CNF1 selectively rescued cognitive defects, without improving other RTT-related behavioural alterations, and restored brain mitochondrial respiratory chain complex activity in MeCP2-Bird mice. To shed light on the molecular mechanisms underlying the differential CNF1 effects on the behavioural phenotype, we compared treatment effects on relevant signalling cascades in the brain of the two RTT models. CNF1 provided a significant boost of the mTOR activation in MeCP2-308 hippocampus, which was not observed in the MeCP2-Bird model, possibly explaining the differential effects of CNF1. These results demonstrate that CNF1 efficacy depends on the mutation beared by MeCP2-mutated mice, stressing the need of testing potential therapeutic approaches across RTT models.


Asunto(s)
Toxinas Bacterianas/farmacología , Encéfalo/efectos de los fármacos , Proteínas de Escherichia coli/farmacología , Proteína 2 de Unión a Metil-CpG/genética , Mitocondrias/efectos de los fármacos , Síndrome de Rett/tratamiento farmacológico , Animales , Toxinas Bacterianas/administración & dosificación , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Proteínas de Escherichia coli/administración & dosificación , Miedo/efectos de los fármacos , Femenino , Infusiones Intraventriculares , Mutación con Pérdida de Función , Masculino , Trastornos de la Memoria/tratamiento farmacológico , Trastornos de la Memoria/etiología , Ratones Mutantes , Proteínas de Microfilamentos/metabolismo , Mitocondrias/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Síndrome de Rett/etiología , Serina-Treonina Quinasas TOR/metabolismo
7.
Int J Mol Sci ; 21(17)2020 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-32867331

RESUMEN

Accumulating evidence indicates that the human intestinal microbiota can contribute to the etiology of colorectal cancer. Triggering factors, including inflammation and bacterial infections, may favor the shift of the gut microbiota from a mutualistic to a pro-carcinogenic configuration. In this context, certain bacterial pathogens can exert a pro-tumoral activity by producing enzymatically-active protein toxins that either directly induce host cell DNA damage or interfere with essential host cell signaling pathways involved in cell proliferation, apoptosis, and inflammation. This review is focused on those toxins that, by mimicking carcinogens and cancer promoters, could represent a paradigm for bacterially induced carcinogenesis.


Asunto(s)
Bacterias/patogenicidad , Toxinas Bacterianas/toxicidad , Neoplasias del Colon/genética , Bacterias/metabolismo , Proliferación Celular , Supervivencia Celular , Neoplasias del Colon/microbiología , Daño del ADN , Microbioma Gastrointestinal , Inestabilidad Genómica , Humanos , Simbiosis
8.
Molecules ; 24(9)2019 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-31060218

RESUMEN

Natural compounds are emerging as agents for the treatment of malignant diseases. We previously showed that extracts from in vitro cell suspension cultures of strawberry reduced murine melanoma cell proliferation, as shown for fruit extracts. In this work, chromatographic, mass spectrometric, and spectrophotometric analyses were carried out to identify the bioactive compound exerting the detected cytotoxic activity. Moreover, aiming to confirm the anti-proliferative activity of the extracts against both paediatric and adult human tumors, cytotoxic experiments were performed on neuroblastoma, colon, and cervix carcinoma cell lines. Extracts from in vitro cell suspension cultures of strawberry induced a statistically significant reduction of cell growth in all the tumor cell lines tested. Interestingly, human fibroblasts from healthy donors were not subjected to this cytotoxic effect, highlighting the importance of further preclinical investigations. The accurate mass measurement, fragmentation patterns, and characteristic mass spectra and mass losses, together with the differences in chromatographic retention times and absorbance spectra, led us to hypothesize that the compound acting as an anti-proliferative agent could be a novel acetal dihydrofurofuran derivative (C8H10O3, molecular mass 154.0630 amu).


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Extractos Celulares/farmacología , Fragaria/citología , Neoplasias/tratamiento farmacológico , Adulto , Antineoplásicos Fitogénicos/química , Extractos Celulares/química , Línea Celular Tumoral , Proliferación Celular , Supervivencia Celular/efectos de los fármacos , Niño , Ensayos de Selección de Medicamentos Antitumorales , Fragaria/química , Humanos
9.
Int J Mol Sci ; 19(7)2018 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-29933571

RESUMEN

The Escherichia coli protein toxin cytotoxic necrotizing factor 1 (CNF1), which acts on the Rho GTPases that are key regulators of the actin cytoskeleton, is emerging as a potential therapeutic tool against certain neurological diseases characterized by cellular energy homeostasis impairment. In this brief communication, we show explorative results on the toxin's effect on fibroblasts derived from a patient affected by myoclonic epilepsy with ragged-red fibers (MERRF) that carries a mutation in the m.8344A>G gene of mitochondrial DNA. We found that, in the patient's cells, besides rescuing the wild-type-like mitochondrial morphology, CNF1 administration is able to trigger a significant increase in cellular content of ATP and of the mitochondrial outer membrane marker Tom20. These results were accompanied by a profound F-actin reorganization in MERRF fibroblasts, which is a typical CNF1-induced effect on cell cytoskeleton. These results point at a possible role of the actin organization in preventing or limiting the cell damage due to mitochondrial impairment and at CNF1 treatment as a possible novel strategy against mitochondrial diseases still without cure.


Asunto(s)
Adenosina Trifosfato/biosíntesis , Toxinas Bacterianas/farmacología , ADN Mitocondrial/genética , Proteínas de Escherichia coli/farmacología , Fibroblastos/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mutación , Toxinas Bacterianas/aislamiento & purificación , ADN Mitocondrial/metabolismo , Complejo IV de Transporte de Electrones/genética , Complejo IV de Transporte de Electrones/metabolismo , Escherichia coli/química , Proteínas de Escherichia coli/aislamiento & purificación , Fibroblastos/metabolismo , Fibroblastos/patología , Expresión Génica , Humanos , Síndrome MERRF/tratamiento farmacológico , Síndrome MERRF/genética , Síndrome MERRF/metabolismo , Síndrome MERRF/patología , Masculino , Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Persona de Mediana Edad , Mitocondrias/genética , Mitocondrias/metabolismo , Mitocondrias/ultraestructura , Proteínas del Complejo de Importación de Proteínas Precursoras Mitocondriales , Proyectos Piloto , Cultivo Primario de Células , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Fibras de Estrés/efectos de los fármacos , Fibras de Estrés/metabolismo , Fibras de Estrés/ultraestructura
10.
Int J Mol Sci ; 19(5)2018 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-29738516

RESUMEN

Cytotoxic necrotizing factor 1 (CNF1) is a bacterial protein toxin primarily expressed by pathogenic Escherichia coli strains, causing extraintestinal infections. The toxin is believed to enhance the invasiveness of E. coli by modulating the activity of Rho GTPases in host cells, but it has interestingly also been shown to promote inflammation, stimulate host immunity and function as a potent immunoadjuvant. The mechanisms underlying the immunostimulatory properties of CNF1 are, however, poorly characterized, and little is known about the direct effects of the toxin on immune cells. Here, we show that CNF1 induces expression of maturation markers on human immature monocyte-derived dendritic cells (moDCs) without compromising cell viability. Consistent with the phenotypic maturation, CNF1 further triggered secretion of proinflammatory cytokines and increased the capacity of moDCs to stimulate proliferation of allogenic naïve CD4+ T cells. A catalytically inactive form of the toxin did not induce moDC maturation, indicating that the enzymatic activity of CNF1 triggers immature moDCs to undergo phenotypic and functional maturation. As the maturation of dendritic cells plays a central role in initiating inflammation and activating the adaptive immune response, the present findings shed new light on the immunostimulatory properties of CNF1 and may explain why the toxin functions as an immunoadjuvant.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Toxinas Bacterianas/química , Células Dendríticas/efectos de los fármacos , Proteínas de Escherichia coli/química , Inflamación/tratamiento farmacológico , Adyuvantes Inmunológicos/química , Toxinas Bacterianas/genética , Toxinas Bacterianas/farmacología , Supervivencia Celular/efectos de los fármacos , Células Dendríticas/inmunología , Escherichia coli/química , Escherichia coli/patogenicidad , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/farmacología , Humanos , Inflamación/inmunología , Inflamación/patología , Monocitos/efectos de los fármacos , Monocitos/inmunología , Proteínas de Unión al GTP rho/genética
11.
Int J Mol Sci ; 19(5)2018 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-29783743

RESUMEN

In this study, we report how the cholera toxin (CT) A subunit (CTA), the enzyme moiety responsible for signaling alteration in host cells, enters the exosomal pathway, secretes extracellularly, transmits itself to a cell population. The first evidence for long-term transmission of CT's toxic effect via extracellular vesicles was obtained in Chinese hamster ovary (CHO) cells. To follow the CT intracellular route towards exosome secretion, we used a novel strategy for generating metabolically-labeled fluorescent exosomes that can be counted by flow cytometry assay (FACS) and characterized. Our results clearly show the association of CT with exosomes, together with the heat shock protein 90 (HSP90) and Protein Disulfide Isomerase (PDI) molecules, proteins required for translocation of CTA across the ER membrane into the cytoplasm. Confocal microscopy showed direct internalization of CT containing fluorescent exo into CHO cells coupled with morphological changes in the recipient cells that are characteristic of CT action. Moreover, Me665 cells treated with CT-containing exosomes showed an increase in Adenosine 3',5'-Cyclic Monophosphate (cAMP) level, reaching levels comparable to those seen in cells exposed directly to CT. Our results prompt the idea that CT can exploit an exosome-mediated cell communication pathway to extend its pathophysiological action beyond an initial host cell, into a multitude of cells. This finding could have implications for cholera disease pathogenesis and epidemiology.


Asunto(s)
Factores de Ribosilacion-ADP/metabolismo , Toxina del Cólera/metabolismo , Exosomas/metabolismo , Animales , Células CHO , Línea Celular Tumoral , Membrana Celular/metabolismo , Cólera/etiología , Toxina del Cólera/química , Toxina del Cólera/toxicidad , Cricetinae , Cricetulus , AMP Cíclico/metabolismo , Proteínas HSP90 de Choque Térmico/metabolismo , Humanos , Proteína Disulfuro Isomerasas/metabolismo , Subunidades de Proteína/metabolismo , Transporte de Proteínas
12.
BMC Cancer ; 14: 449, 2014 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-24939046

RESUMEN

BACKGROUND: Glioblastomas are largely unresponsive to all available treatments and there is therefore an urgent need for novel therapeutics. Here we have probed the antineoplastic effects of a bacterial protein toxin, the cytotoxic necrotizing factor 1 (CNF1), in the syngenic GL261 glioma cell model. CNF1 produces a long-lasting activation of Rho GTPases, with consequent blockade of cytodieresis in proliferating cells and promotion of neuron health and plasticity. METHODS: We have tested the antiproliferative effects of CNF1 on GL261 cells and human glioma cells obtained from surgical specimens. For the in vivo experiments, we injected GL261 cells into the adult mouse visual cortex, and five days later we administered either a single intracerebral dose of CNF1 or vehicle. To compare CNF1 with a canonical antitumoral drug, we infused temozolomide (TMZ) via minipumps for 1 week in an additional animal group. RESULTS: In culture, CNF1 was very effective in blocking proliferation of GL261 cells, leading them to multinucleation, senescence and death within 15 days. CNF1 had a similar cytotoxic effect in primary human glioma cells. CNF1 also inhibited motility of GL261 cells in a scratch-wound migration assay. Low dose (2 nM) CNF1 and continuous TMZ infusion significantly prolonged animal survival (median survival 35 days vs. 28 days in vehicle controls). Remarkably, increasing CNF1 concentration to 80 nM resulted in a dramatic enhancement of survival with no obvious toxicity. Indeed, 57% of the CNF1-treated animals survived up to 60 days following GL261 glioma cell transplant. CONCLUSIONS: The activation of Rho GTPases by CNF1 represents a novel potential therapeutic strategy for the treatment of central nervous system tumors.


Asunto(s)
Antineoplásicos/farmacología , Toxinas Bacterianas/farmacología , Proteínas de Escherichia coli/farmacología , Glioma/patología , Animales , Antineoplásicos/administración & dosificación , Toxinas Bacterianas/administración & dosificación , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Proteínas de Escherichia coli/administración & dosificación , Glioma/tratamiento farmacológico , Glioma/mortalidad , Humanos , Ratones , Factores de Tiempo , Ensayo de Tumor de Célula Madre
13.
Diabetes Res Clin Pract ; 213: 111732, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38838944

RESUMEN

BACKGROUND: In lower extremity peripheral artery disease (PAD), the ankle-brachial index (ABI) is an easily reproducible diagnostic tool for PAD, but it loses reliability when > 1.4 due to calcification of the vessel wall. Patients with diabetes are at higher risk for wall calcification. In order to overcome the limitation and reliability of ABI, particularly in patients with diabetes, we decided to assess resistive (RI) and pulsatility index (PI) by ultrasound doppler of the dorsal metatarsal artery (DMA). RESULTS: We therefore analyzed 51 legs (32 patients), evaluating the correlation between PI, RI, and ABI. Patients with diabetes were 21 (65.6 %), accounting for 33 legs (64.7 %). Out of 51 legs assessed, 37 (72.5 %) cases had compressible arteries, whereas in 14 legs (27.5 %) ABI was not calculable due to wall calcification. PAD was significantly associated with lower both RI and PI of the DMA (both p < 0.000). RI, but not PI, showed a significant correlation (r = 0.535) with ABI, when ABI was less than 1.4, but not when ABI > 1.4. When analyzed separately, patients with diabetes showed a similar figure in comparison with those without diabetes (r = 0.600), RI, but not PI, showed a significant correlation with ABI. CONCLUSION: Dorsal metatarsal artery resistive index (MARI) showed a significant inverse correlation with PAD, similarly to ABI, irrespective of the presence of diabetes. MARI seems to be an effective screening tool for PAD even in patients with wall calcification. Further studies are needed for confirming the results of the present pilot study.


Asunto(s)
Índice Tobillo Braquial , Enfermedad Arterial Periférica , Humanos , Enfermedad Arterial Periférica/fisiopatología , Enfermedad Arterial Periférica/diagnóstico por imagen , Enfermedad Arterial Periférica/diagnóstico , Femenino , Masculino , Anciano , Persona de Mediana Edad , Flujo Pulsátil/fisiología , Resistencia Vascular/fisiología , Ultrasonografía Doppler , Arterias/diagnóstico por imagen , Arterias/fisiopatología
14.
J Neurosci ; 31(42): 15163-72, 2011 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-22016550

RESUMEN

A classical example of age-dependent plasticity is ocular dominance (OD) plasticity, triggered by monocular deprivation (MD). Sensitivity of cortical circuits to a brief period of MD is maximal in juvenile animals and downregulated in adult age. It remains unclear whether a reduced potential for morphological remodeling underlies this downregulation of physiological plasticity in adulthood. Here we have tested whether stimulation of structural rearrangements is effective in promoting experience-dependent plasticity in adult age. We have exploited a bacterial protein toxin, cytotoxic necrotizing factor 1 (CNF1), that regulates actin dynamics and structure of neuronal processes via a persistent activation of Rho GTPases. Injection of CNF1 into the adult rat visual cortex triggered a long-lasting activation of the Rho GTPase Rac1, with a consequent increase in spine density and length in pyramidal neurons. Adult rats treated with CNF1, but not controls, showed an OD shift toward the open eye after MD. CNF1-mediated OD plasticity was selectively attributable to the enhancement of open-eye responses, whereas closed-eye inputs were unaffected. This effect correlated with an increased density of geniculocortical terminals in layer IV of monocularly deprived, CNF1-treated rats. Thus, Rho GTPase activation reinstates OD plasticity in the adult cortex via the potentiation of more active inputs from the open eye. These data establish a direct link between structural remodeling and functional plasticity and demonstrate a role for Rho GTPases in brain plasticity in vivo. The plasticizing effects of Rho GTPase activation may be exploited to promote brain repair.


Asunto(s)
Plasticidad Neuronal/fisiología , Corteza Visual/citología , Corteza Visual/enzimología , Proteínas de Unión al GTP rho/metabolismo , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/fisiología , Análisis de Varianza , Animales , Toxinas Bacterianas/farmacología , Antígeno CD11b/metabolismo , Espinas Dendríticas/efectos de los fármacos , Espinas Dendríticas/enzimología , Predominio Ocular/efectos de los fármacos , Predominio Ocular/fisiología , Proteínas de Escherichia coli/farmacología , Potenciales Evocados Visuales/efectos de los fármacos , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Regulación de la Expresión Génica/fisiología , Proteína Básica de Mielina/metabolismo , Plasticidad Neuronal/efectos de los fármacos , Fosfopiruvato Hidratasa/metabolismo , Lectinas de Plantas/metabolismo , Ratas , Ratas Long-Evans , Receptores N-Acetilglucosamina/metabolismo , Privación Sensorial/fisiología , Estadísticas no Paramétricas , Factores de Tiempo , Proteína 2 de Transporte Vesicular de Glutamato/metabolismo , Vías Visuales/fisiología
15.
Int J Cancer ; 130(6): 1273-83, 2012 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21445970

RESUMEN

Caveolae have been indicated as a center of cytoskeleton regulation for Src kinase/Rho GTPase signaling. In addition, Src recruitment on intact cortical actin cytoskeleton appears to be required for bFGF/FGFR signal activation. Recently, we established a relationship between caveolin-1 (Cav-1) expression and cell migration in human malignant melanoma, constitutively activated by a bFGF autoregulatory loop. This work intends to investigate whether caveolae's asset, through bFGF/FGFR/c-Src/Rho signaling, could be related to melanoma cell anchorage. Accordingly, we revealed the existence of a FGFR/Src kinase pathway in Cav-1 enriched detergent-resistant membranes (DRMs) of Me665/1 metastatic melanoma cells, as confirmed by FGFR silencing. Moreover, we determined the expression and phosphorylation levels of Cav-1/Src/Erk signal pathway as a function of FGFR activation and cell density. A sucrose density gradient ultracentrifugation was employed to monitor Cav-1 membrane association and buoyancy in Me665/1 cells treated for actin fragmentation or for altered phosphorylation signals. As a result, melanoma cells show remarkable resistance to Cav-1 disassembly, together with persisting cell signal activity, being Src and Cav-1 crucial modulators of Rho GTPases. In conclusion, our study primarily highlights, in a metastatic melanoma cell line expressing caveolin, the circumstances whereby caveola structural and functional endurance enables the FGFR/Src/Rho GTPases pathway to keep on cell progression.


Asunto(s)
Caveolina 1/metabolismo , Melanoma/metabolismo , Receptores de Factores de Crecimiento de Fibroblastos/metabolismo , Proteínas de Unión al GTP rho/metabolismo , Familia-src Quinasas/metabolismo , Actinas/metabolismo , Caveolina 1/genética , Recuento de Células , Línea Celular Tumoral , Membrana Celular/genética , Membrana Celular/metabolismo , Movimiento Celular/fisiología , Citoesqueleto/genética , Citoesqueleto/metabolismo , Humanos , Sistema de Señalización de MAP Quinasas , Melanoma/genética , Melanoma/patología , Fosforilación , Receptores de Factores de Crecimiento de Fibroblastos/genética , Transducción de Señal , Proteínas de Unión al GTP rho/genética , Familia-src Quinasas/genética
16.
Am J Cancer Res ; 12(2): 651-660, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35261793

RESUMEN

Colorectal cancer (CRC) is a leading cause of cancer death worldwide. The risk of developing CRC is influenced by both environmental and genetic factors. Recently, chronic inflammation and gut microbiota modifications have been associated with increased CRC risk. Escherichia coli belongs to the commensal intestinal flora and can become highly pathogenic following the acquisition of genes coding for virulence factors, such as the cytotoxic necrotizing factor type 1 (CNF1). Numerous reports highlight that, besides exerting direct effects on epithelial cells, CNF1 can also act on immune cells, modulating their responses and possibly contributing to disease development. In the present review, we summarized the key studies addressing the immunomodulatory functions of CNF1 and discussed the contribution that CNF1 can bring about to CRC through the creation of a pro-inflammatory microenvironment.

17.
Eur J Intern Med ; 100: 62-68, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35058148

RESUMEN

BACKGROUND: Gastrointestinal (GI) manifestations are frequent in systemic sclerosis (SSc) with an impact on quality of life and morbidity. Bowel vasculopathy is a key pathogenetic factor responsible for GI involvement. OBJECTIVES: To compare abdominal ultrasound (US) and Color Doppler Ultrasonography (CDU) features of splanchnic vessels of SSc patients with healthy controls. METHODS: The charts of SSc patients who underwent an abdominal US and CDU study were retrospectively analyzed. For Superior Mesenteric Artery (SMA) and Inferior Mesenteric Artery (IMA) caliber, Peak Systolic Velocity (PSV), Reverse Velocity (RV), End-Diastolic Velocity (EDV), Mean Velocity (mV), Blood-flow, Resistive Index (RI) and Pulsatility Index (PI) were recorded. RESULTS: 28 SSc patients and 28 controls were enrolled. In SSc, caliber of SMA was significantly smaller than in controls (5.75 ± 0.62 mm vs. 6.45 ± 0.60 mm, p < 0.0001 - p adj =0.0002). The flow study of SMA and IMA showed a significant reduction of RV (SMA: 7.25 ± 6.37 cm/s vs. 18.52 ± 6.16 cm/s, p < 0.0001 - p adj <0.0001; IMA: 2.69 ± 6.10 cm/s vs. 17.06 ± 5.75 cm/s, p < 0.0001 - p adj <0.0001) and PI (SMA: 3.33 ± 0.75 vs. 4.53 ± 1.03, p < 0.0001 - p adj =0.0002; IMA: 3.54 ± 0.95 vs. 6.08 ± 1.53, p < 0.0001 - p adj <0.0001) in SSc patients than controls. CONCLUSION: involvement of splanchnic vessels in SSc may be non-invasively investigated with abdominal US and CDU. Morphological and functional changes of Doppler parameters observed in SMA and IMA clearly demonstrate that these vessels are affected by SSc vasculopathy.


Asunto(s)
Esclerodermia Sistémica , Enfermedades Vasculares , Humanos , Arteria Mesentérica Superior/diagnóstico por imagen , Arteria Mesentérica Superior/patología , Calidad de Vida , Estudios Retrospectivos , Esclerodermia Sistémica/complicaciones , Esclerodermia Sistémica/diagnóstico por imagen , Ultrasonografía Doppler en Color
18.
PLoS Pathog ; 5(10): e1000603, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19798427

RESUMEN

Infection with Helicobacter pylori is responsible for gastritis and gastroduodenal ulcers but is also a high risk factor for the development of gastric adenocarcinoma and lymphoma. The most pathogenic H. pylori strains (i.e., the so-called type I strains) associate the CagA virulence protein with an active VacA cytotoxin but the rationale for this association is unknown. CagA, directly injected by the bacterium into colonized epithelium via a type IV secretion system, leads to cellular morphological, anti-apoptotic and proinflammatory effects responsible in the long-term (years or decades) for ulcer and cancer. VacA, via pinocytosis and intracellular trafficking, induces epithelial cell apoptosis and vacuolation. Using human gastric epithelial cells in culture transfected with cDNA encoding for either the wild-type 38 kDa C-terminal signaling domain of CagA or its non-tyrosine-phosphorylatable mutant form, we found that, depending on tyrosine-phosphorylation by host kinases, CagA inhibited VacA-induced apoptosis by two complementary mechanisms. Tyrosine-phosphorylated CagA prevented pinocytosed VacA to reach its target intracellular compartments. Unphosphorylated CagA triggered an anti-apoptotic activity blocking VacA-induced apoptosis at the mitochondrial level without affecting the intracellular trafficking of the toxin. Assaying the level of apoptosis of gastric epithelial cells infected with wild-type CagA(+)/VacA(+)H. pylori or isogenic mutants lacking of either CagA or VacA, we confirmed the results obtained in cells transfected with the CagA C-ter constructions showing that CagA antagonizes VacA-induced apoptosis. VacA toxin plays a role during H. pylori stomach colonization. However, once bacteria have colonized the gastric niche, the apoptotic action of VacA might be detrimental for the survival of H. pylori adherent to the mucosa. CagA association with VacA is thus a novel, highly ingenious microbial strategy to locally protect its ecological niche against a bacterial virulence factor, with however detrimental consequences for the human host.


Asunto(s)
Antígenos Bacterianos/metabolismo , Apoptosis/fisiología , Proteínas Bacterianas/metabolismo , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/metabolismo , Helicobacter pylori/patogenicidad , Antígenos Bacterianos/genética , Proteínas Bacterianas/genética , Western Blotting , Línea Celular , Helicobacter pylori/metabolismo , Humanos , Inmunoprecipitación , Microscopía Confocal , Mutagénesis Sitio-Dirigida , Fosforilación , Proteínas Recombinantes de Fusión , Transfección , Tirosina/metabolismo
19.
Crit Rev Microbiol ; 37(1): 1-14, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20874522

RESUMEN

In this review, we discuss the multifactorial role of intestinal microbiota in colorectal cancer. The peculiar metabolism of dietary compounds of the individual microbiota complement, its overall immunostimulation and immunomodulatory activity, and eventually the production of toxins that perturb the regulation of cell growth, define the balance of positive and negative risk factors for colorectal cancer development. Moreover, shaping the composition of the human intestinal microbiota, diet has an indirect impact in determining the balance between health and disease. The integration of diet, microbial, and host factors in a system approach is mandatory to determine the overall balance of risk and protective factors for colorectal cancer onset.


Asunto(s)
Neoplasias Colorrectales/microbiología , Intestinos/microbiología , Metagenoma , Dieta , Humanos , Intestinos/inmunología
20.
Acta Cardiol ; 66(6): 791-6, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22299392

RESUMEN

OBJECTIVE: The aim of this study was to evaluate the adherence to recommendations for secondary prevention of cardiovascular diseases in patients with acute coronary syndromes (ACS). METHODS AND RESULTS: Physical examination, a careful medical interview with assessment for lifestyle habits, adherence to pharmacological therapy and blood analyses were performed in 130 patients at the time of the acute event and after 6 months of follow-up. At follow-up examination, 7 patients persisted to smoke (5.4%), 41 (31.5%) continued to have high blood pressure, 34 (26.1%) had high levels of total cholesterol, 38 (29.2%) high levels of triglycerides, 64 (49.2%) high levels of LDL-cholesterol and 46 (35.4%) low levels of HDL-cholesterol. Despite all treatments no significant change occurred. A high percentage of patients (47%) reported a lower daily consumption of fruit and vegetables with respect to the recommended daily portions, nearly the whole population (92.3%) did not reach the recommended portions of legumes per week recommended, and a consistent percentage of patients (81.5%) did not consume fish twice a week, as recommended. CONCLUSION: These findings demonstrate the difficulty of modifying the lifestyle habits in patients with ACS.


Asunto(s)
Síndrome Coronario Agudo/terapia , Estilo de Vida , Cooperación del Paciente/estadística & datos numéricos , Síndrome Coronario Agudo/sangre , Síndrome Coronario Agudo/tratamiento farmacológico , Síndrome Coronario Agudo/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Dieta , Femenino , Conductas Relacionadas con la Salud , Humanos , Italia , Masculino , Persona de Mediana Edad , Sistema de Registros , Factores de Riesgo , Prevención Secundaria , Fumar/epidemiología
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