Agonist-induced formation of FGFR1 homodimers and signaling differ among members of the FGF family.

Fibroblast growth factor receptor 1 (FGFR1) is known to be activated by homodimerization in the presence of both the FGF agonist ligand and heparan sulfate glycosaminoglycan. FGFR1 homodimers in turn trigger a variety of downstream signaling cascades via autophosphorylation of tyrosine residues in the cytoplasmic domain of FGFR1. By means of Bioluminescence Energy Resonance Transfer (BRET) as a sign of FGFR1 homodimerization, we evaluated in HEK293T cells the effects of all known FGF agonist ligands on homodimer formation. A significant correlation between BRET(2) signaling and ERK1/2 phosphorylation was observed, leading to a further characterization of the binding and signaling properties of the FGF subfamilies. FGF agonist ligand-FGFR1 binding interactions appear as the main mechanism for the control of FGFR1 homodimerization and MAPK signaling which demonstrated a high correlation. The bioinformatic analysis demonstrates the interface of the two pro-triplets SSS (Ser-Ser-Ser) and YGS (Tyr-Gly-Ser) located in the extracellular and intracellular domain of the FGFR1. These pro-triplets are postulated participate in the FGFR1 homodimerization interface interaction. The findings also reveal that FGF agonist ligands within the same subfamily of the FGF gene family produced similar increases in FGFR1 homodimer formation and MAPK signaling. Thus, the evolutionary relationship within this gene family appears to have a distinct functional relevance

Microvesicle and tunneling nanotube mediated intercellular transfer of g-protein coupled receptors in cell cultures.

none12Recent evidence shows that cells exchange collections of signals via microvesicles (MVs) and tunneling nano-tubes (TNTs). In this paper we have investigated whether in cell cultures GPCRs can be transferred by means of MVs and TNTs from a source cell to target cells. Western blot, transmission electron microscopy and gene expression analyses demonstrate that A(2A) and D(2) receptors are present in released MVs. In order to further demonstrate the involvement of MVs in cell-to-cell communication we created two populations of cells (HEK293T and COS-7) transiently transfected with D(2)R-CFP or A(2A)R-YFP. These two types of cells were co-cultured, and FRET analysis demonstrated simultaneously positive cells to the D(2)R-CFP and A(2A)R-YFP. Fluorescence microscopy analysis also showed that GPCRs can move from one cell to another also by means of TNTs. Finally, recipient cells pre-incubated for 24 h with A(2A)R positive MVs were treated with the adenosine A(2A) receptor agonist CGS-21680. The significant increase in cAMP accumulation clearly demonstrated that A(2A)Rs were functionally competent in target cells. These findings demonstrate that A(2A) receptors capable of recognizing and decoding extracellular signals can be safely transferred via MVs from source to target cells.openM. Guescini; G. Leo; S. Genedani; C. Carone; F. Pederzoli; F. Ciruela; D. Guidolin; V. Stocchi; M. Mantuano; D.O. Borroto-Escuela; K. Fuxe; L.F. AgnatiGuescini, Michele; G., Leo; S., Genedani; C., Carone; F., Pederzoli; F., Ciruela; D., Guidolin; Stocchi, Vilberto; Mantuano, Michela; D. O., Borroto Escuela; K., Fuxe; L. F., Agnat

Artículos de los proyectos de grado realizados por los estudiantes de ingeniería mecánica que se graduaron en el 2006

This document presents the articles of the final year undergraduate of the Department of Mechanical Engineering at EAFIT University in 2006. Each article contains information about the area of interest (Design of Technical Systems, Industrial Maintenance and Projects of Technical Systems), the main adviser, institution who benefited from the project and the Spanish and English summary with key words in English and Spanish. Some of the articles are included in their full length version.The originality and the pertinence of the articles convert them into a bibliographical valuable material for the engineering and especially for the mechanical engineering community. Each one of articles represents a particular view into a new practice of the mechanical engineering in Colombia and the world.Este documento presenta la relación de los artículos de los proyectos de grado de la carrera de Ingeniería Mecánica de la Universidad EAFIT en el año 2006. La información de cada artículo, contiene el área de énfasis (Diseño en Sistemas Técnicos, Mantenimiento Industrial y Proyectos de Sistemas Técnicos), el asesor principal del trabajo de grado, el sector beneficiado, el resumen en español y en inglés con las palabras claves en los dos idiomas y los resultados del trabajo de grado.La originalidad y pertinencia de los artículos los convierten en un material bibliográfico valioso para la ingeniería y en especial para la ingeniería mecánica. Cada uno de los artículos representa un punto de vista particular en la nueva práctica de la ingeniería mecánica en Colombia y en el mundo

Attenuation of oxytocin and serotonin 2A receptor signaling through novel heteroreceptor formation

The oxytocin receptor (OTR) and the 5-hydroxytryptamine 2A receptor (5-HTR2A) are expressed in similar brain regions modulating central pathways critical for social and cognition-related behaviors. Signaling crosstalk between their endogenous ligands, oxytocin (OT) and serotonin (5-hydroxytryptamine, 5-HT), highlights the complex interplay between these two neurotransmitter systems and may be indicative of the formation of heteroreceptor complexes with subsequent downstream signaling changes. In this study, we assess the possible formation of OTR-5HTR2A heteromers in living cells and the functional downstream consequences of this receptor–receptor interaction. First, we demonstrated the existence of a physical interaction between the OTR and 5-HTR2Ain vitro, using a flow cytometry-based FRET approach and confocal microscopy. Furthermore, we investigated the formation of this specific heteroreceptor complex ex vivo in the brain sections using the Proximity Ligation Assay (PLA). The OTR-5HTR2A heteroreceptor complexes were identified in limbic regions (including hippocampus, cingulate cortex, and nucleus accumbens), key regions associated with cognition and social-related behaviors. Next, functional cellular-based assays to assess the OTR-5HTR2A downstream signaling crosstalk showed a reduction in potency and efficacy of OT and OTR synthetic agonists, carbetocin and WAY267464, on OTR-mediated Gαq signaling. Similarly, the activation of 5-HTR2A by the endogenous agonist, 5-HT, also revealed attenuation in Gαq-mediated signaling. Finally, altered receptor trafficking within the cell was demonstrated, indicative of cotrafficking of the OTR/5-HTR2A pair. Overall, these results constitute a novel mechanism of specific interaction between the OT and 5-HT neurotransmitters via OTR-5HTR2A heteroreceptor formation and provide potential new therapeutic strategies in the treatment of social and cognition-related diseases

Heteroreceptor complexes formed by dopamine D1, histamine H3 and N-methyl-D-aspartate glutamate receptors as targets to prevent neuronal death in Alzheimer's disease

Alzheimer’s disease (AD) is a neurodegenerative disorder causing progressive memory loss and cognitive dysfunction. Anti-AD strategies targeting cell receptors consider them as isolated units. However, many cell surface receptors cooperate and physically contact each other forming complexes having different biochemical properties than individual receptors. We here report the discovery of dopamine D , histamine H , and N-methylD-aspartate (NMDA) glutamate receptor heteromers in heterologous systems and in rodent brain cortex. Heteromers were detected by coimmunoprecipitation and in situ proximity ligation assays (PLA) in the rat cortex where H receptor agonists, via negative cross-talk, and H receptor antagonists, via cross-antagonism, decreased D receptor agonist signaling determined by ERK1/2 or Akt phosphorylation and counteracted D receptormediated excitotoxic cell death. Both D and H receptor antagonists also counteracted NMDA toxicity suggesting a complex interaction between NMDA receptors and D -H receptor heteromer function. Likely due to heteromerization, H receptors act as allosteric regulator for D and NMDA receptors. By bioluminescence resonance energy transfer (BRET), we demonstrated that D or H receptors form heteromers with NR1A/NR2B NMDA receptor subunits. D -H -NMDA receptor complexes were confirmed by BRET combined with fluorescence complementation. The endogenous expression of complexes in mouse cortex was determined by PLA and similar expression was observed in wild-type and APP/PS1 mice. Consistent with allosteric receptor-receptor interactions within the complex, H receptor antagonists reduced NMDA or D receptor-mediated excitotoxic cell death in cortical organotypic cultures. Moreover, H receptor antagonists reverted the toxicity induced by ß -amyloid peptide. Thus, histamine H receptors in D -H -NMDA heteroreceptor complexes arise as promising targets to prevent neurodegeneration

POTENCIAL PROBIÓTICO DE CEPAS DE BACILLUS CON PROPIEDADES ANTIMICROBIANAS FRENTE A PATÓGENOS DE PECES

El objetivo de este trabajo ha sido aislar, identificar y caracterizar cepas bacterianas procedentes de ambiente marino, fitoplancton, zooplancton, huevos, larvas de lenguado y diferentes juveniles (branquias, intestino, piel), que pudieran tener actividad probiótica y actividad antibacteriana frente a distintos patógenos de peces. Se aislaron un total de 217 cepas bacterianas. Tras un primer cribado mediante ensayos de inhibición en placa frente a patógenos, se seleccionaron 9 cepas y se identificaron utilizando la secuenciación de su rRNA 16S. Los resultados mostraron que las mejores candidatas eran cepas del género Bacillus. Varios de estas posibles cepas candidatas se caracterizaron in vitro para determinar su potencial probiótico, mediante ensayos de inhibición en co-cultivo con V. anguillarum, resistencia a bilis de pez, y adherencia a mucus intestinal de pez. Nuestros resultados mostraron que algunas de las cepas seleccionadas pertenecientes al género Bacillus, podrían ser consideradas como potenciales probióticos frente a patógenos de peces, por lo que el beneficio de la administración de estas cepas a cultivos de peces será posteriormente estudiada

Molecular, biochemical and behavioural evidence for a novel oxytocin receptor and serotonin 2C receptor heterocomplex

The complexity of oxytocin-mediated functions is strongly associated with its modulatory effects on other neurotransmission systems, including the serotonin (5-hydroxytryptamine, 5-HT) system. Signalling between oxytocin (OT) and 5-HT has been demonstrated during neurodevelopment and in the regulation of specific emotion-based behaviours. It is suggested that crosstalk between neurotransmitters is driven by interaction between their specific receptors, particularly the oxytocin receptor (OTR) and the 5-hydroxytryptamine 2C receptor (5-HTR2C), but evidence for this and the downstream signalling consequences that follow are lacking. Considering the overlapping central expression profiles and shared involvement of OTR and 5-HTR2C in certain endocrine functions and behaviours, including eating behaviour, social interaction and locomotor activity, we investigated the existence of functionally active OTR/5-HTR2C heterocomplexes. Here, we demonstrate evidence for a potential physical interaction between OTR and 5-HTR2C in vitro in a cellular expression system using flow cytometry-based FRET (fcFRET). We could recapitulate this finding under endogenous expression levels of both receptors via in silico analysis of single cell transcriptomic data and ex vivo proximity ligation assay (PLA). Next, we show that co-expression of the OTR/5-HTR2C pair resulted in a significant depletion of OTR-mediated G alpha q-signalling and significant changes in receptor trafficking. Of note, attenuation of OTR-mediated downstream signalling was restored following pharmacological blockade of the 5-HTR2C. Finally, we demonstrated a functional relevance of this novel heterocomplex, in vivo, as 5-HTR2C antagonism increased OT-mediated hypoactivity in mice. Overall, we provide compelling evidence for the formation of functionally active OTR/5-HTR2C heterocomplexes, adding another level of complexity to OTR and 5-HTR2C signalling functionality.This article is part of the special issue on Neuropeptides

Heterogeneity of prodromal Parkinson symptoms in siblings of Parkinson disease patients

A prodromal phase of Parkinson’s disease (PD) may precede motor manifestations by decades. PD patients’ siblings are at higher risk for PD, but the prevalence and distribution of prodromal symptoms are unknown. The study objectives were (1) to assess motor and non-motor features estimating prodromal PD probability in PD siblings recruited within the European PROPAG-AGEING project; (2) to compare motor and non-motor symptoms to the well-established DeNoPa cohort. 340 PD siblings from three sites (Bologna, Seville, Kassel/Goettingen) underwent clinical and neurological evaluations of PD markers. The German part of the cohort was compared with German de novo PD patients (dnPDs) and healthy controls (CTRs) from DeNoPa. Fifteen (4.4%) siblings presented with subtle signs of motor impairment, with MDS-UPDRS-III scores not clinically different from CTRs. Symptoms of orthostatic hypotension were present in 47 siblings (13.8%), no different to CTRs (p = 0.072). No differences were found for olfaction and overall cognition; German-siblings performed worse than CTRs in visuospatial-executive and language tasks. 3/147 siblings had video-polysomnography-confirmed REM sleep behavior disorder (RBD), none was positive on the RBD Screening Questionnaire. 173/300 siblings had <1% probability of having prodromal PD; 100 between 1 and 10%, 26 siblings between 10 and 80%, one fulfilled the criteria for prodromal PD. According to the current analysis, we cannot confirm the increased risk of PD siblings for prodromal PD. Siblings showed a heterogeneous distribution of prodromal PD markers and probability. Additional parameters, including strong disease markers, should be investigated to verify if these results depend on validity and sensitivity of prodromal PD criteria, or if siblings’ risk is not elevated

A geroscience approach for Parkinson's disease: Conceptual framework and design of PROPAG-AGEING project

Advanced age is the major risk factor for idiopathic Parkinson's disease (PD), but to date the biological relationship between PD and ageing remains elusive. Here we describe the rationale and the design of the H2020 funded project “PROPAG-AGEING”, whose aim is to characterize the contribution of the ageing process to PD development. We summarize current evidences that support the existence of a continuum between ageing and PD and justify the use of a Geroscience approach to study PD. We focus in particular on the role of inflammaging, the chronic, low-grade inflammation characteristic of elderly physiology, which can propagate and transmit both locally and systemically. We then describe PROPAG-AGEING design, which is based on the multi-omic characterization of peripheral samples from clinically characterized drug-naïve and advanced PD, PD discordant twins, healthy controls and "super-controls", i.e. centenarians, who never showed clinical signs of motor disability, and their offspring. Omic results are then validated in a large number of samples, including in vitro models of dopaminergic neurons and healthy siblings of PD patients, who are at higher risk of developing PD, with the final aim of identifying the molecular perturbations that can deviate the trajectories of healthy ageing towards PD development

Early downregulation of hsa-miR-144-3p in serum from drug-naïve Parkinson’s disease patients

open101siThis work was supported by the Horizon 2020 Framework Programme (Grant number 634821, PROPAG-AGING).Advanced age represents one of the major risk factors for Parkinson’s Disease. Recent biomedical studies posit a role for microRNAs, also known to be remodelled during ageing. However, the relationship between microRNA remodelling and ageing in Parkinson’s Disease, has not been fully elucidated. Therefore, the aim of the present study is to unravel the relevance of microRNAs as biomarkers of Parkinson’s Disease within the ageing framework. We employed Next Generation Sequencing to profile serum microRNAs from samples informative for Parkinson’s Disease (recently diagnosed, drug-naïve) and healthy ageing (centenarians) plus healthy controls, age-matched with Parkinson’s Disease patients. Potential microRNA candidates markers, emerging from the combination of differential expression and network analyses, were further validated in an independent cohort including both drug-naïve and advanced Parkinson’s Disease patients, and healthy siblings of Parkinson’s Disease patients at higher genetic risk for developing the disease. While we did not find evidences of microRNAs co-regulated in Parkinson’s Disease and ageing, we report that hsa-miR-144-3p is consistently down-regulated in early Parkinson’s Disease patients. Moreover, interestingly, functional analysis revealed that hsa-miR-144-3p is involved in the regulation of coagulation, a process known to be altered in Parkinson’s Disease. Our results consistently show the down-regulation of hsa-mir144-3p in early Parkinson’s Disease, robustly confirmed across a variety of analytical and experimental analyses. These promising results ask for further research to unveil the functional details of the involvement of hsa-mir144-3p in Parkinson’s Disease.openZago E.; Dal Molin A.; Dimitri G.M.; Xumerle L.; Pirazzini C.; Bacalini M.G.; Maturo M.G.; Azevedo T.; Spasov S.; Gomez-Garre P.; Perinan M.T.; Jesus S.; Baldelli L.; Sambati L.; Calandra Buonaura G.; Garagnani P.; Provini F.; Cortelli P.; Mir P.; Trenkwalder C.; Mollenhauer B.; Franceschi C.; Lio P.; Nardini C.; Adarmes-Gomez A.; Azevedo T.; Bacalini M.G.; Baldelli L.; Bartoletti-Stella A.; Bhatia K.P.; Marta B.-T.; Boninsegna C.; Broli M.; Dolores B.-R.; Calandra-Buonaura G.; Capellari S.; Carrion-Claro M.; Cilea R.; Clayton R.; Cortelli P.; Molin A.D.; De Luca S.; De Massis P.; Dimitri G.M.; Doykov I.; Escuela-Martin R.; Fabbri G.; Franceschi C.; Gabellini A.; Garagnani P.; Giuliani C.; Gomez-Garre P.; Guaraldi P.; Hagg S.; Hallqvist J.; Halsband C.; Heywood W.; Houlden H.; Huertas I.; Jesus S.; Jylhava J.; Labrador-Espinosa M.A.; Licari C.; Lio P.; Luchinat C.; Macias D.; Macri S.; Magrinelli F.; Rodriguez J.F.M.; Massimo D.; Maturo M.G.; Mengozzi G.; Meoni G.; Mignani F.; Milazzo M.; Mills K.; Mir P.; Mollenhauer B.; Nardini C.; Nassetti S.A.; Pedersen N.L.; Perinan-Tocino M.T.; Pirazzini C.; Provini F.; Ravaioli F.; Sala C.; Sambati L.; Scaglione C.L.M.; Schade S.; Schreglmann S.; Spasov S.; Strom S.; Tejera-Parrado C.; Tenori L.; Trenkwalder C.; Turano P.; Valzania F.; Ortega R.V.; Williams D.; Xumerle L.; Zago E.Zago E.; Dal Molin A.; Dimitri G.M.; Xumerle L.; Pirazzini C.; Bacalini M.G.; Maturo M.G.; Azevedo T.; Spasov S.; Gomez-Garre P.; Perinan M.T.; Jesus S.; Baldelli L.; Sambati L.; Calandra Buonaura G.; Garagnani P.; Provini F.; Cortelli P.; Mir P.; Trenkwalder C.; Mollenhauer B.; Franceschi C.; Lio P.; Nardini C.; Adarmes-Gomez A.; Azevedo T.; Bacalini M.G.; Baldelli L.; Bartoletti-Stella A.; Bhatia K.P.; Marta B.-T.; Boninsegna C.; Broli M.; Dolores B.-R.; Calandra-Buonaura G.; Capellari S.; Carrion-Claro M.; Cilea R.; Clayton R.; Cortelli P.; Molin A.D.; De Luca S.; De Massis P.; Dimitri G.M.; Doykov I.; Escuela-Martin R.; Fabbri G.; Franceschi C.; Gabellini A.; Garagnani P.; Giuliani C.; Gomez-Garre P.; Guaraldi P.; Hagg S.; Hallqvist J.; Halsband C.; Heywood W.; Houlden H.; Huertas I.; Jesus S.; Jylhava J.; Labrador-Espinosa M.A.; Licari C.; Lio P.; Luchinat C.; Macias D.; Macri S.; Magrinelli F.; Rodriguez J.F.M.; Massimo D.; Maturo M.G.; Mengozzi G.; Meoni G.; Mignani F.; Milazzo M.; Mills K.; Mir P.; Mollenhauer B.; Nardini C.; Nassetti S.A.; Pedersen N.L.; Perinan-Tocino M.T.; Pirazzini C.; Provini F.; Ravaioli F.; Sala C.; Sambati L.; Scaglione C.L.M.; Schade S.; Schreglmann S.; Spasov S.; Strom S.; Tejera-Parrado C.; Tenori L.; Trenkwalder C.; Turano P.; Valzania F.; Ortega R.V.; Williams D.; Xumerle L.; Zago E