314 research outputs found
Involvement of both caspase-8 and Noxa-activated pathways in endoplasmic reticulum stress-induced apoptosis in triple-negative breast tumor cells
Recent evidences indicate that triple-negative breast cancer (TNBC) cells with a mesenchymal phenotype show a basal activation of the unfolded protein response (UPR) that increases their sensitivity to endoplasmic reticulum (ER) stress although the underlying cell death mechanism remains largely unexplored. Here we show that both caspase-8-dependent and -independent apoptotic mechanisms are activated in TNBC cells undergoing sustained ER stress. Activation of the extrinsic apoptotic pathway by ER stress involves ATF4-dependent upregulation of tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2/DR5). In addition, accumulation of BH3-only protein Noxa at the mitochondria further contributes to apoptosis following ER stress in TNBC cells. Accordingly, simultaneous abrogation of both extrinsic and intrinsic apoptotic pathways is required to inhibit ER stress-induced apoptosis in these cells. Importantly, persistent FLICE-inhibitory protein (FLIP) expression plays an adaptive role to prevent early activation of the extrinsic pathway of apoptosis upon ER stress. Overall, our data show that ER stress induces cell death through a pleiotropic mechanism in TNBC cells and suggest that targeting FLIP expression may be an effective approach to sensitize these tumor cells to ER stress-inducing agents
INTECO Webmessenger: Study of the Usability in Instant Messaging Systems
The main aim of this project is dual. Firstly, it is to achieve a complete analysis of the necessities of disabled people on the Internet. Secondly, it is intended to develop an instant messaging system based on the Windows Live Messenger whose requirements are defined over the previous analysis. This software is called INTECO Webmessenge
Conservation of limpet populations: a heavily exploited resource in Azores, NE-Atlantic
10th International Temperate Reefs Symposium, The University of Western Australia, 12-17 de janeiro.Limpet harvesting in Azores (NE Atlantic) has been taking place probably since the islands were first colonized in the XV century. Limpet species are highly exploited and populations from most islands have declined steadily bringing about catastrophic effects on coastal communities. Despite their economic importance limpets are also ecologically key species and require prioritizing conservation strategies. Patellid limpets are broadcast spawners which go through a planktonic larval stage in their life cycle. They are benthic as adults and the larva is the only phase during their life-cycle which has the ability to disperse over assumed large spatial distances. However, there is now mounting evidence that gene flow between islands and mainlands can be low, even for species with a relatively long planktonic larval stage. Low levels of larval exchange may thus limit the success of conservation objectives expected upon migration and recruitment. In dispersive isolated oceanic islands such as the Macaronesian Islands, the Azores Archipelago in particular, is not clear whether limpet populations from different islands form a single meta-population or, in contrast, populations on each island are isolated from the rest. Knowledge on this scenario is crucial for the management and conservation of exploited populations of limpets. Here we have developed and described species-specific multiplexed microsatellite markers for the limpets Patella candei and Patella aspera using whole genome shotgun 454 sequencing. These genetic tools have allowed the study of the population genetic structure and evolutionary history of patellid species in the archipelago of Azores. Genetic studies, alongside with biological, ecological and oceanographic information, represent an important contribution for the understanding of population dynamics by allowing testing hypothesis about larval dispersal patterns, recruitment and life history traits, population connectivity, genetic diversity, and population equilibrium
Angiotensin AT1 and AT2 receptors heteromer expression in microglia correlates with Parkinson's disease progression in the hemilesioned rat model of the disease
Background/Aims : The renin-angiotensin system (RAS) is altered in Parkinson's disease (PD), a disease due to substantia nigra neurodegeneration and whose dopamine-replacement therapy, using the precursor levodopa, leads to dyskinesias as the main side effect. Angiotensin AT 1 and AT 2 receptors, mainly known for their role in regulating water homeostasis and blood pressure and able to form heterodimers (AT 1/2 Hets), are present in the central nervous system. We assessed the functionality and expression of AT 1/2 Hets in Parkinson Disease (PD). Methods: Immunocytochemistry was used to analyze the colocalization between angiotensin receptors, bioluminescence resonance energy transfer was used to detect AT 1/2 Hets. Calcium and cAMP determination, MAPK activation and label-free assays were performed to characterize signaling. Proximity ligation assays was used to quantify receptor expression in microglial cells and brain striatal slices. Results: We confirmed that AT 1 and AT 2 receptors form AT 1/2 Hets that are expressed in cells of the central nervous system. AT 1/2 Hets are novel functional units with particular signaling properties. Importantly, the coactivation of the two receptors in the heteromer reduces the signaling output of angiotensin. Remarkably, AT 1/2 Hets that are expressed in both striatal neurons and microglia show a cross-potentiation, i.e. candesartan, the antagonist of AT 1 increases the effect of AT 2 receptor agonists. In addition, the level of expression in the unilateral 6-OH-dopamine lesion rat PD model increases upon disease progression and is maximal in dyskinetic animals. Conclusion: The results indicate that boosting the action of neuroprotective AT 2 receptors using an AT 1 receptor antagonist constitutes a promising therapeutic strategy in PD
Angiotensin AT 1 and AT 2 receptor heteromer expression in the hemilesioned rat model of Parkinson's disease that increases with levodopa-induced dyskinesia
Background/aims: The renin-angiotensin system (RAS) is altered in Parkinson's disease (PD), a disease due to substantia nigra neurodegeneration and whose dopamine-replacement therapy, using the precursor levodopa, leads to dyskinesias as the main side effect. Angiotensin AT1 and AT2 receptors, mainly known for their role in regulating water homeostasis and blood pressure and able to form heterodimers (AT1/2Hets), are present in the central nervous system. We assessed the functionality and expression of AT1/2Hets in Parkinson disease (PD). Methods: Immunocytochemistry was used to analyze the colocalization between angiotensin receptors; bioluminescence resonance energy transfer was used to detect AT1/2Hets. Calcium and cAMP determination, MAPK activation, and label-free assays were performed to characterize signaling in homologous and heterologous systems. Proximity ligation assays were used to quantify receptor expression in mouse primary cultures and in rat striatal sections. Results: We confirmed that AT1 and AT2 receptors form AT1/2Hets that are expressed in cells of the central nervous system. AT1/2Hets are novel functional units with particular signaling properties. Importantly, the coactivation of the two receptors in the heteromer reduces the signaling output of angiotensin. Remarkably, AT1/2Hets that are expressed in both striatal neurons and microglia make possible that candesartan, the antagonist of AT1, increases the effect of AT2 receptor agonists. In addition, the level of striatal expression increased in the unilateral 6-OH-dopamine lesioned rat PD model and was markedly higher in parkinsonian-like animals that did not become dyskinetic upon levodopa chronic administration if compared with expression in those that became dyskinetic. Conclusion: The results indicate that boosting the action of neuroprotective AT2 receptors using an AT1 receptor antagonist constitutes a promising therapeutic strategy in PD. Keywords: Dyskinesia; G-protein-coupled receptor (GPCR); Heteromer; Levodopa; Neuroinflammation
Evidence of Zika virus horizontal and vertical transmission in Aedes albopictus from Spain but not infectious virus in saliva of the progeny
Aedes albopictus mosquitoes have been experimentally demonstrated to be a competent vector for Zika virus (ZIKV) in different countries, but there are still some gaps related to the importance of Ae. albopictus in ZIKV transmission. Recent studies on Spanish Ae. albopictus populations showed controversial results for ZIKV transmission and no studies have been performed yet to detect infectious ZIKV in saliva of progeny of infected female mosquitoes. Herein, the horizontal transmission (HT) and vertical transmission (VT) of ZIKV in field-collected Ae. albopictus mosquitoes from Spain were evaluated for ZIKV strains (African I and Asian lineages) to better estimate the risk of ZIKV transmission by Ae. albopictus. The two field-collected Ae. albopictus populations assayed were infected by all tested ZIKV strains, however differences in terms of vector competence were detected depending on strain-population combination. Moreover, a higher susceptibility to the African I lineage strain than to the Asian lineage strain was observed in both mosquito populations. On the other hand, VT was demonstrated for both ZIKV lineages, detecting the virus in both males and females of the progeny of infected females, although importantly ZIKV dissemination and transmission were not detected in the infected females from the offspring. The results of the present study demonstrate that Spanish Ae. albopictus populations could sustain virus transmission in case of ZIKV introduction, but VT would play a poor role in the ZIKV epidemiology. Overall, our results provide helpful information to health authorities to establish efficient surveillance and vector control programs for ZIKV.info:eu-repo/semantics/publishedVersio
European Aedes caspius mosquitoes are experimentally unable to transmit Zika virus
Background: Aedes caspius (Pallas, 1771) is a foodwater mosquito species widely distributed in the Western Palae‑
arctic. As an anthropophilic species, its role as an arbovirus vector may be the key for understanding the transmission
cycle of certain diseases in Europe such as Zika virus (ZIKV). Concerning vector competence for ZIKV, studies related to
Ae. caspius are still scarce. ZIKV is an arbovirus that has provoked a widespread epidemic in the Pacifc region (2007–
2013) and in the Americas (2015–2016). ZIKV is associated with serious neurological injuries (e.g. microcephaly) and
Guillain-Barré syndrome. Due to the ZIKV epidemics in the American continent, some viraemic travellers coming from
endemic countries have been reported in Europe. More knowledge is therefore required to defne the susceptibility
of autochthonous mosquito species such as Ae. caspius for ZIKV in order to improve arbovirus surveillance and control
programmes. In the present study, the vector competence of a European population of Ae. caspius was evaluated for
two ZIKV lineages, the Suriname ZIKV strain (Asian lineage) and the MR766 ZIKV strain (African I lineage). Females were
tested at 7, 14 and 21 days post-exposure (dpe) to infectious blood meals. An Ae. aegypti PAEA strain was used as a
positive control.
Results: Aedes caspius presented low susceptibility to ZIKV infection and the virus was only detected by RT-qPCR
in body samples. Low viral loads were detected for the MR766 strain at 7 dpe and for the Suriname strain at 14 and
21 dpe. Aedes caspius was unable to produce a disseminated infection and virus transmission at any of the tested time
points. Using Ae. aegypti PAEA strain, infection, dissemination and transmission rates were calculated for the Suriname
ZIKV strain (Asian lineage) at each time point. For the MR766 ZIKV strain (African I lineage), while only infection rates
were estimated at each time point, no dissemination or transmission were detected in either species.
Conclusions: The results of the present study reveal that the tested Ae. caspius population has a strong midgut
escape barrier that limits the dissemination or transmission of the virus. As such, it seems unlikely that European Ae.
caspius mosquitoes could be involved in ZIKV transmission if ZIKV was introduced into Europe. This information may
help in designing a better strategy to European surveillance and control programmes for ZIKV.info:eu-repo/semantics/publishedVersio
Synthesis, structural characterization, and ligand replacement reactions of gem-dithiolato-bridged rhodium and iridium complexes
The reaction of gem-dithiol compounds R2C(SH)2 (R = Bn (benzyl), iPr; R2 = −(CH2)4−) with dinuclear rhodium or iridium complexes containing basic ligands such as [M(μ-OH)(cod)]2 and [M(μ-OMe)(cod)]2, or the mononuclear [M(acac)(cod)] (M = Rh, Ir, cod = 1,5-cyclooctadiene) in the presence of a external base, afforded the dinuclear complexes [M2(μ-S2CR2)(cod)2] (1−4). The monodeprotonation of 1,1-dimercaptocyclopentane gave the mononuclear complex [Rh(HS2Cptn)(cod)] (5) that is a precursor for the dinuclear compound [Rh2(μ-S2Cptn)(cod)2] (6). Carbonylation of the diolefin compounds gave the complexes [Rh2(μ-S2CR2)(CO)4] (7−9), which reacted with P-donor ligands to stereoselectively produce the trans isomer of the disubstituted complexes [Rh2(μ-S2CR2)(CO)2(PR′3)2] (R′ = Ph, Cy (cyclohexyl)) (10−13) and [Rh2(μ-S2CBn2)(CO)2{P(OR′)3}2] (R′ = Me, Ph) (14−15). The substitution process in [Rh2(μ-S2CBn2)(CO)4] (7) by P(OMe)3 has been studied by spectroscopic means and the full series of substituted complexes [Rh2(μ-S2CBn2)(CO)4−n{P(OR)3}n] (n = 1, 4) has been identified in solution. The cis complex [Rh2(μ-S2CBn2)(CO)2(μ-dppb)] (16) was obtained by reaction of 7 with the diphosphine dppb (1,4-bis(diphenylphosphino)butane). The molecular structures of the diolefinic dinuclear complexes [Rh2(μ-S2CR2)(cod)2] (R = Bn (1), iPr (2); R2 = −(CH2)4− (6)) and that of the cis complex 16 have been studied by X-ray diffraction.The financial support from Ministerio de Educación y Ciencia (MEC/FEDER) Project CTQ2006-03973/BQU is gratefully acknowledged. A. B. R. thanks the Programa Iberoamericano de Ciencia y Tecnología para el Desarrollo (CYTED) for a fellowship.
Also, A.B. R. and A.J. P. thank to Fonacit-Venezuela (S1-2002000260) for financial support.Peer Reviewe
Functional complexes of Angiotensin-converting enzyme 2 and renin-angiotensin system receptors: expression in adult but not fetal lung tissue
Angiotensin-converting enzyme 2 (ACE2) is a membrane peptidase and a componentof the renin-angiotensin system (RAS) that has been found in cells of all organs, including thelungs. While ACE2 has been identified as the receptor for severe acute respiratory syndrome (SARS)coronaviruses, the mechanism underlying cell entry remains unknown. Human immunodeficiencyvirus infects target cells via CXC chemokine receptor 4 (CXCR4)-mediated endocytosis. Furthermore,CXCR4 interacts with dipeptidyl peptidase-4 (CD26/DPPIV), an enzyme that cleaves CXCL12/SDF-1,which is the chemokine that activates this receptor. By analogy, we hypothesized that ACE2 mightalso be capable of interactions with RAS-associated G-protein coupled receptors. Using resonanceenergy transfer and cAMP and mitogen-activated protein kinase signaling assays, we found thathuman ACE2 interacts with RAS-related receptors, namely the angiotensin II type 1 receptor (AT1R),the angiotensin II type 2 receptor (AT2R), and the MAS1 oncogene receptor (MasR). Although theseinteractions led to various alterations of signal transduction, but, more importantly, ligand binding toAT1R resulted in the downregulation of ACE2 cell surface expression, while ligand binding to AT2R,but not to MasR, resulted in upregulation of ACE2 cell surface expression. Proximity ligation assaysperformed in situ revealed macromolecular complexes containing ACE2 and AT1R, AT2R or MasR inadult but not fetal mouse lung tissue. These findings highlight the relevance of RAS in SARS-CoV-2infection and the role of ACE2-containing complexes as potential therapeutic targets
Development and characterization of microsattelite Loci for the harvested limpets Patella Candei (D'orbigny, 1839) and Patella Aspera (Röding, 1798) using 454 sequencing
World Congress of Malacology, Ponta Delgada, July 22-28, 2013.There is growing consensus that anthropogenic activities are impacting the structure and functioning of marine ecosystems and that these can have profound community level effects, particularly when targeting keystone species. Limpet harvesting in Azores (NE Atlantic) has been taking place probably since the islands were first colonized. These species are highly exploited and the stocks in most islands have declined steadily with catastrophic effects on coastal communities. They are a locally important resource but also ecologically important species and require prioritizing conservation strategies. Such strategies should be su pported by reliable data on the structure and dynamics of their populations, so that ecological hotspots are identified and protected. Characterizing the genetic diversity and structure of marine exploited populations is thus of paramount importance to identify such units of conservation. Here we describe and develop species-specific microsatellite markers for the harvested limpets Patella candei and Patella aspera using whole genome shotgun 454 sequencing. A total of 309 bioinformatic-validated pairs of primers were obtained from P. aspera microsatellite enriched library. The optimization of the amplification conditions of selectect microsatellites (simplex and multiplex reactions) was performed in a gradient thermal cycler to optimize locus-specific amplification conditions and test their utility as genetic markers. Forty pairs of primers were tested, and about 28 revealed to be polymorphic. Using the same procedure, a total of 107 pairs of primers were validated for P. candei of which 15 turned out to be polymorphic. These novel genetic markers can be used to study the population genetic structure and evolutionary history of both patellid species e.g. levels of genetic variability within and between populations, and thus to contribute for stock conservation and management along their distributional area
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