548 research outputs found
A selective alpha1D-adrenoreceptor antagonist inhibits human prostate cancer cell proliferation and motility "in vitro"
The progression of prostate cancer (PC) to a metastatic hormone refractory disease is the major contributor to the overall cancer mortality in men, mainly because the conventional therapies are generally ineffective at this stage. Thus, other therapeutic options are needed as alternatives or in addition to the classic approaches to prevent or delay tumor progression. Catecholamines participate to the control of prostate cell functions by the activation of alpha1-adrenoreceptors (alpha1-AR) and increased sympathetic activity has been linked to PC development and evolution. Molecular and pharmacological studies identified three alpha1-AR subtypes (A, B and D), which differ in tissue distribution, cell signaling, pharmacology and physiological role. Within the prostate, alpha1A-ARs mainly control stromal cell functions, while alpha1B- and alpha1D- subtypes seem to modulate glandular epithelial cell growth. The possible direct contribution of alpha1D-ARs in tumor biology is supported by their overexpression in PC. The studies here presented investigate the "in vitro" antitumor action of A175, a selective alpha1D-AR antagonist we have recently obtained by modifying the potent, but not subtype-selective alpha1-AR antagonist (S)-WB4101, in the hormone-refractory PC3 and DU145 PC cell lines. The results indicate that A175 has an alpha1D-AR-mediated significant and dose-dependent antiproliferative action that possibly involves the induction of G0/G1 cell cycle arrest, but not apoptosis. In addition, A175 reduces cell migration and adhesiveness to culture plates. In conclusion, our work clarified some cellular aspects promoted by alpha1D-AR activity modulation and supports a further pharmacological approach in the cure of hormone-refractory PC, by targeting specifically this AR subtype
The small non-coding RNA processing machinery of two living fossil species, lungfish and coelacanth, gives new insights into the evolution of the Argonaute protein family
Argonaute (AGO) family proteins play many roles in epigenetic programming, genome rearrangement, mRNA breakdown, inhibition of translation, and transposon silencing. Despite being a hotspot in current scientific research, their evolutionary history is still poorly understood and consequently the identification of evolutionary conserved structural features should also generate useful information for better understanding their functions. We report here for the first time the transcript sets of the two subfamilies, Ago and Piwi, in the West African lungfish Protopterus annectens and in the Indonesian coelacanth Latimeria menadoensis, two key species in the evolutionary lineage leading to tetrapods. The phylogenetic analysis of 142 inferred protein sequences in 22 fully sequenced species and the analysis of microsynteny performed in the major vertebrate lineages indicate an intricate pattern for the evolution of both subfamilies that has been shaped by whole genome duplications and lineage specific gains and losses. The argonaute subfamily was additionally expanded by local gene duplications at the base of the jawed vertebrate lineage. The subfamily of Piwi proteins is involved in several processes such as spermatogenesis, piRNA biogenesis, and transposon repression. Expression assessment of AGO genes and genes coding for proteins involved in small RNA biogenesis suggests a limited activity of the Piwi pathway in lungfish in agreement with the lungfish genome containing mainly old and inactive transposons
IL-17 signaling components in bivalves: Comparative sequence analysis and involvement in the immune responses
The recent discovery of soluble immune-regulatory molecules in invertebrates takes advantage of the rapid growth of next generation sequencing datasets. Following protein domain searches in the transcriptomes of 31 bivalve spp. and in few available mollusk genomes, we retrieved 59 domains uniquely identifying interleukin 17 (IL-17) and 96 SEFIR domains typical of IL-17 receptors and CIKS/ACT1 proteins acting downstream in the IL-17 signaling pathway. Compared to the Chordata IL-17 family members, we confirm a separate clustering of the bivalve domain sequences and a consistent conservation pattern of amino acid residues. Analysis performed at transcript and genome level allowed us to propose an updated view of the components outlining the IL-17 signaling pathway in Mytilus galloprovincialis and Crassostrea gigas (in both species, homology modeling reduced the variety of IL-17 domains to only two 3D structures). Digital expression analysis indicated more heterogeneous expression levels for the mussel and oyster IL-17 ligands than for IL-17 receptors and CIKS/CIKSL proteins. Besides, new qPCR analyses confirmed such gene expression trends in hemocytes and gills of mussels challenged with heat-killed bacteria. These results uphold the involvement of an ancient IL-17 signaling pathway in the bivalve immune responses and, likewise in humans, suggest the possibility of distinctive modulatory roles of individual IL-17s/IL-17 receptors. Overall, the common evidence of pro-inflammatory cytokines and inter-related intracellular signaling pathways in bivalves definitely adds complexity to the invertebrate immunity
RNA sequencing and de novo assembly of the digestive gland transcriptome in Mytilus galloprovincialis fed with toxinogenic and non-toxic strains of Alexandrium minutum
Background
The Mediterranean mussel Mytilus galloprovincialis is marine bivalve with a relevant
commercial importance as well as a key sentinel organism for the biomonitoring of
environmental pollution. Here we report the RNA sequencing of the mussel digestive gland,
performed with the aim: a) to produce a high quality de novo transcriptome assembly, thus
improving the genetic and molecular knowledge of this organism b) to provide an initial
assessment of the response to paralytic shellfish poisoning (PSP) on a molecular level, in
order to identify possible molecular markers of toxin accumulation.
Results
The comprehensive de novo assembly and annotation of the transcriptome yielded a
collection of 12,079 non-redundant consensus sequences with an average length of 958 bp,
with a high percentage of full-length transcripts. The whole-transcriptome gene expression
study indicated that the accumulation of paralytic toxins produced by the dinoflagellate
Alexandrium minutum over a time span of 5 days scarcely affected gene expression, but the
results need further validation with a greater number of biological samples and naturally
contaminated specimens.
Conclusion
The digestive gland reference transcriptome we produced significantly improves the data
collected from previous sequencing efforts and provides a basic resource for expanding
functional genomics investigations in M. galloprovincialis. Although not conclusive, the
results of the RNA-seq gene expression analysis support the classification of mussels as
bivalves refractory to paralytic shellfish poisoning and point out that the identification
molecular biomarkers of PSP in the digestive gland of this organism is problematic
Immunoglobulin T from sea bass (Dicentrarchus labrax L.): Molecular characterization, tissue localization and expression after nodavirus infection
Background
Immunoglobulins (Igs) are fundamental components of the adaptive immune system of vertebrates, with the IgT/IgZ isotype specific of Teleosts. In this paper we describe the identification of an IgT heavy chain from the European sea bass (Dicentrarchus labrax L.), its molecular characterization and tissue mRNA localization by in situ hybridization.
Results
Sea bass IgT consists of 552 aa (Accession Number KM410929) and it contains a putative 19 amino acids long signal peptide and one potential N-glycosylation site. The C-region consists of four CH domains; each contains the cysteine and tryptophan residues required for their correct folding. Based on the recent sequencing of sea bass genome, we have identified five different genomic contigs bearing exons unequivocally pertaining to IgT (CH2, CH3 and CH4), but none corresponded to a complete IgH locus as IgT sequences were found in the highly fragmented assembled genomic regions which could not be assigned to any major scaffold. The 3D structure of sea bass IgT has been modelled using the crystal structure of a mouse Ig gamma as a template, thus showing that the amino acid sequence is suitable for the expected topology referred to an immunoglobulin-like architecture. The basal expression of sea bass IgT and IgM in different organs has been analysed: gut and gills, important mucosal organs, showed high IgT transcripts levels and this was the first indication of the possible involvement of sea bass IgT in mucosal immune responses. Moreover, sea bass IgT expression increased in gills and spleen after infection with nodavirus, highlighting the importance of IgT in sea bass immune responses. In situ hybridization confirmed the presence of IgT transcripts in the gut and it revealed a differential expression along the intestinal tract, with a major expression in the posterior intestine, suggesting the hindgut as a site for the recruitment of IgT+ cells in this species. IgT transcripts were also found in gill filaments and parallel lamellae and, for the first time, we identified scattered IgT positive cells in the liver, with a strong signal in the hepatic parenchyma.
Conclusions
In conclusion, we performed a full molecular characterization of IgT in sea bass that points out its possible involvement in mucosal immune responses of this species
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