排序方式: 共有250条查询结果,搜索用时 31 毫秒
181.
Gaia Colasante Stefania Crispi Ahmed Mansouri Vania Broccoli 《Developmental biology》2009,334(1):59-71
The homeobox-containing gene Arx is expressed during ventral telencephalon development and required for correct GABAergic interneuron tangential migration from the ganglionic eminences to the olfactory bulbs, cerebral cortex and striatum. Its human ortholog is associated with a variety of neurological clinical manifestations whose symptoms are compatible with the loss of cortical interneurons and altered basal ganglia-related activities. Herein, we report the identification of a number of genes whose expression is consistently altered in Arx mutant ganglionic eminences. Our analyses revealed a striking ectopic expression in the ganglionic eminences of several of these genes normally at most marginally expressed in the ventral telencephalon. Among them, Ebf3 was functionally analyzed. Thus, its ectopic expression in ventral telencephalon was found to prevent neuronal tangential migration. Further, we showed that Arx is sufficient to repress Ebf3 endogenous expression and that its silencing in Arx mutant tissues partially rescues tangential cell movement. Together, these data provide new insights into the molecular pathways regulated by Arx during telencephalon development. 相似文献
182.
Luvoni GC Chigioni S Perego L Lodde V Modina S Luciano AM 《Animal reproduction science》2006,96(1-2):66-78
Information about the mechanisms of meiotic arrest and resumption of meiosis in feline oocytes is still limited. The aim of this study was to investigate the effect of the presence of gonadotropins during IVM, on meiotic progression in relation to the status of gap junction mediated communications between oocyte and cumulus cells, to the cAMP intracellular content, and to the intra-oocyte concentration of glutathione (GSH) in feline oocytes. Our results indicated that about 50% of cumulus-oocyte complexes (COCs) showed functionally open communications at the time of collection, while the remainder were partially or totally closed. After 3h of culture, the percentage of COCs with functional gap junctions was significantly greater in the group matured in the presence of gonadotropins than in those matured without them, where an interruption of communications was observed. Moreover, this precocious uncoupling was associated with a moderate increase of cAMP concentration in the oocyte, lower than in the group exposed to gonadotropins. Intra-oocyte glutathione levels decreased significantly after 24h of IVM, whether gonadotropins were present or absent during the culturing process. The presence of thiol compounds in the IVM medium induced an intra-oocyte GSH concentration significantly higher than that found in oocytes cultured without these compounds, and similar to the GSH content of immature oocytes. Moreover, the intracellular GSH concentration increased as meiosis progressed. The present study suggests that in feline oocytes, gonadotropins affect the dynamic changes in communications between oocyte and cumulus cells during IVM. However, the intracellular concentration of GSH is not influenced by the gonadotropin stimulation. Moreover, the presence of gonadotropins and thiol compounds results in an increase of GSH levels along with meiotic progression of the oocytes. 相似文献
183.
Dose-response curves, resulting in estimates of endpoints such as the IC(50), are fundamental to drug discovery. However, some estimates are more reliable than others. It is important to know just how reliable an estimate is if we want to base decisions on it or use it in further modeling. In this study, the authors propose a new measure of endpoint reliability, based on the concept of desirability first introduced by Harrington. The solution is not dependent on the application used to analyze the experimental data, provided a number of parameters to characterize the dose-response curve are available. The authors show how this score can be used as an objective and consistent measure to rank screening results, combine information from groups of experiments, and determine optimal levels of characterization of a compound's biological activity. 相似文献
184.
Paola Stiuso Gaia Giuberti Angela Lombardi Alessandra Dicitore Vittorio Limongelli Maria Cartenì Alberto Abbruzzese Michele Caraglia 《Amino acids》2010,39(3):661-670
We previously demonstrated that the γ-glutamyl 16 amine derivative of vasoactive intestinal peptide (VIP) acts as structural
VIP agonist with affinity and potency higher than VIP. Herein, we have evaluated the effects of VIP and γ-Gln16-diaminopropane
derivative of VIP (VIP-DAP3) on the proliferation and protection from oxidative stress induced by hydrogen peroxide (H2O2) on epidermoid carcinoma cell lines. We have found that 10−11 M VIP-DAP3 completely antagonized the inhibition induced by H2O2 on both cell proliferation and S-phase distribution while these effects were only partially antagonized by equimolar concentrations
of VIP. Moreover, both oxidative stress and intracellular lipid oxidation induced by H2O2 were reduced by VIP and completely antagonized by VIP-DAP3. Thereafter, we have found that H2O2 increased p38 kinase activity and both HSP70 and HSP27 expression. VIP and VIP-DAP3 again antagonized these effects partially
or totally, respectively. H2O2 reduced the activity of extracellular signal-regulated kinases Erk-1/2 and Akt, signalling proteins involved in proliferation/survival
pathways. Again VIP restored the activity of both kinases while VIP-DAP3 caused indeed an increase of their activity as compared
to untreated cells. These data suggest that VIP-DAP3 has a stronger anti-oxidative activity as compared to VIP likely based
on its super-agonistic binding on the putative receptor. 相似文献
185.
Space-filling neurons extensively sample their receptive fields with fine dendritic branches. In this study we show that a member of the conserved Robo receptor family, Robo, and its ligand Slit regulate the dendritic differentiation of space-filling neurons. Loss of Robo or Slit function leads to faster elongating and less branched dendrites of the complex and space-filling class IV multi-dendritic dendrite-arborization (md-da) neurons in the Drosophila embryonic peripheral nervous system, but not of the simpler class I neurons. The total dendrite length of Class IV neurons is not modified in robo or slit mutant embryos. Robo mediates this process cell-autonomously. Upon Robo over-expression in md-da neurons the dendritic tree is simplified and time-lapse analysis during larval stages indicates that this is due to reduction in the number of newly formed branches. We propose that Slit, through Robo, provides an extrinsic signal to coordinate the growth rate and the branching level of space-filling neurons, thus allowing them to appropriately cover their target field. 相似文献
186.
187.
Schwartz JW Novarino G Piston DW DeFelice LJ 《The Journal of biological chemistry》2005,280(19):19177-19184
The human norepinephrine (NE) transporter (hNET) attenuates neuronal signaling by rapid NE clearance from the synaptic cleft, and NET is a target for cocaine and amphetamines as well as therapeutics for depression, obsessive-compulsive disorder, and post-traumatic stress disorder. In spite of its central importance in the nervous system, little is known about how NET substrates, such as NE, 1-methyl-4-tetrahydropyridinium (MPP+), or amphetamine, interact with NET at the molecular level. Nor do we understand the mechanisms behind the transport rate. Previously we introduced a fluorescent substrate similar to MPP+, which allowed separate and simultaneous binding and transport measurement (Schwartz, J. W., Blakely, R. D., and DeFelice, L. J. (2003) J. Biol. Chem. 278, 9768-9777). Here we use this substrate, 4-(4-(dimethylamino)styrl)-N-methyl-pyridinium (ASP+), in combination with green fluorescent protein-tagged hNETs to measure substrate-transporter stoichiometry and substrate binding kinetics. Calibrated confocal microscopy and fluorescence correlation spectroscopy reveal that hNETs, which are homomultimers, bind one substrate molecule per transporter subunit. Substrate residence at the transporter, obtained from rapid on-off kinetics revealed in fluorescence correlation spectroscopy, is 526 micros. Substrate residence obtained by infinite dilution is 1000 times slower. This novel examination of substrate-transporter kinetics indicates that a single ASP+ molecule binds and unbinds thousands of times before being transported or ultimately dissociated from hNET. Calibrated fluorescent images combined with mass spectroscopy give a transport rate of 0.06 ASP+/hNET-protein/s, thus 36,000 on-off binding events (and 36 actual departures) occur for one transport event. Therefore binding has a low probability of resulting in transport. We interpret these data to mean that inefficient binding could contribute to slow transport rates. 相似文献
188.
189.
Gaia Bazzi Andrea Galimberti Quentin R. Hays Ilaria Bruni Jacopo G. Cecere Luca Gianfranceschi Keith A. Hobson Yolanda E. Morbey Nicola Saino Christopher G. Guglielmo Diego Rubolini 《Ecology and evolution》2016,6(10):3226-3239
Understanding the genetic background of complex behavioral traits, showing multigenic control and extensive environmental effects, is a challenging task. Among such traits, migration is known to show a large additive genetic component. Yet, the identification of specific genes or gene regions explaining phenotypic variance in migratory behavior has received less attention. Migration ultimately depends on seasonal cycles, and polymorphism at phenological candidate genes may underlie variation in timing of migration or other aspects of migratory behavior. In this study of a Nearctic–Neotropical migratory songbird, the Wilson's warbler (Cardellina pusilla), we investigated the association between polymorphism at two phenological candidate genes, Clock and Adcyap1, and two aspects of the migratory phenotype, timing of spring migration through a stopover site and inferred latitude of the breeding destination. The breeding destination of migrating individuals was identified using feather deuterium ratio (δ2H), which reliably reflects breeding latitude throughout the species' western breeding range. Ninety‐eight percent of the individuals were homozygous at Clock, and the rare heterozygotes did not deviate from homozygous migration phenology. Adcyap1 was highly polymorphic, and allele size was not significantly associated with migration date. However, Adcyap1 allele size significantly positively predicted the inferred breeding latitude of males but not of females. Moreover, we found a strong positive association between inferred breeding latitude and Adcyap1 allele size in long‐distance migrating birds from the northern sector of the breeding range (western Canada), while this was not the case in short‐distance migrating birds from the southern sector of the breeding range (coastal California). Our findings support previous evidence for a role of Adcyap1 in shaping the avian migratory phenotype, while highlighting that patterns of phenological candidate gene–phenotype associations may be complex, significantly varying between geographically distinct populations and even between the sexes. 相似文献
190.
Alessandra Stacchiotti Gaia Favero Antonio Lavazza Igor Golic Marija Aleksic Aleksandra Korac Luigi Fabrizio Rodella Rita Rezzani 《PloS one》2016,11(1)