67 resultados para tissue remodelling gene


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As pituitary function depends on the integrity of the hypothalamic-pituitary axis, any defect in the development and organogenesis of this gland may account for a form of combined pituitary hormone deficiency (CPHD). A mutation in a novel, tissue-specific, paired-like homeodomain transcription factor, termed Prophet of Pit-1 (PROP1), has been identified as causing the Ames dwarf (df) mouse phenotype, and thereafter, different PROP1 gene alterations have been found in humans with CPHD. We report on the follow-up of two consanguineous families (n = 12), with five subjects affected with CPHD (three males and two females) caused by the same nucleotide C to T transition, resulting in the substitution of Arg-->Cys in PROP1 at codon 120. Importantly, there is a variability of phenotype, even among patients with the same mutation. The age at diagnosis was dependent on the severity of symptoms, ranging from 9 months to 8 yr. Although in one patient TSH deficiency was the first symptom of the disorder, all patients became symptomatic by exhibiting severe growth retardation and failure to thrive, which was mainly caused by GH deficiency (n = 4). The secretion of the pituitary-derived hormones (GH, PRL, TSH, LH, and FSH) declined gradually with age, following a different pattern in each individual; therefore, the deficiencies developed over a variable period of time. All of the subjects entered puberty spontaneously, and the two females also experienced menarche and periods before a replacement therapy was necessary.

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Synchrotron Microbeam Radiation Therapy (MRT) relies on the spatial fractionation of the synchrotron photon beam into parallel micro-beams applying several hundred of grays in their paths. Several works have reported the therapeutic interest of the radiotherapy modality at preclinical level, but biological mechanisms responsible for the described efficacy are not fully understood to date. The aim of this study was to identify the early transcriptomic responses of normal brain and glioma tissue in rats after MRT irradiation (400Gy). The transcriptomic analysis of similarly irradiated normal brain and tumor tissues was performed 6 hours after irradiation of 9 L orthotopically tumor-bearing rats. Pangenomic analysis revealed 1012 overexpressed and 497 repressed genes in the irradiated contralateral normal tissue and 344 induced and 210 repressed genes in tumor tissue. These genes were grouped in a total of 135 canonical pathways. More than half were common to both tissues with a predominance for immunity or inflammation (64 and 67% of genes for normal and tumor tissues, respectively). Several pathways involving HMGB1, toll-like receptors, C-type lectins and CD36 may serve as a link between biochemical changes triggered by irradiation and inflammation and immunological challenge. Most immune cell populations were involved: macrophages, dendritic cells, natural killer, T and B lymphocytes. Among them, our results highlighted the involvement of Th17 cell population, recently described in tumor. The immune response was regulated by a large network of mediators comprising growth factors, cytokines, lymphokines. In conclusion, early response to MRT is mainly based on inflammation and immunity which appear therefore as major contributors to MRT efficacy.

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The cpb2 gene of beta2-toxigenic Clostridium perfringens isolated from horses, cattle, sheep, human and pigs was sequenced. The cpb2 gene of equine and other non-porcine isolates differed from porcine isolates by the absence of an adenine in a poly A tract immediately downstream of the start codon in all non-porcine C. perfringens strains. This deletion involved formation of a cryptic gene harbouring a premature stop codon after only nine amino acid codons, while the full beta2-toxin protein consists of 265 amino acids. Immunoblots carried out with antibodies directed against a recombinant beta2-toxin showed the absence of expression of the beta2-toxin in equine and the other non-porcine strains under standard culture conditions. However, treatment of C. perfringens with the aminoglycosides gentamicin or streptomycin was able to induce expression of the cpb2 gene in a representative equine strain of this group, presumably by frameshifting. The presence of the beta2-toxin was revealed by immunohistology in tissue samples of small and large intestine from horses with severe typhlocolitis that had been treated before with gentamicin. This result may explain the finding that antibiotic treatment of horses affected by beta2-toxigenic C. perfringens leads to a more accentuated and fatal progression of equine typhlocolitis. Clinical observations show a reduced appearance of strong typhlocolitis in horses with intestinal complications admitted to hospital care since the standard use of gentamicin has been abandoned. This is the first report on expression of a bacterial toxin gene by antibiotic-induced ribosomal frameshifting.

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For the efficient translocation of organic nitrogen, small peptides of two to three amino acids are posited as an important alternative to amino acids. A new transporter mediating the uptake of di- and tripeptides was isolated from Arabidopsis thaliana by heterologous complementation of a peptide transport-deficient Saccharomyces cerevisiae mutant. AtPTR1 mediated growth of S. cerevisiae cells on different di- and tripeptides and caused sensitivity to the phytotoxin phaseolotoxin. The spectrum of substrates recognized by AtPTR1 was determined in Xenopus laevis oocytes injected with AtPTR1 cRNA under voltage clamp conditions. AtPTR1 not only recognized a broad spectrum of di- and tripeptides, but also substrates lacking a peptide bond. However, amino acids, omega-amino fatty acids or peptides with more than three amino acid residues did not interact with AtPTR1. At pH 5.5 AtPTR1 had an apparent lower affinity (K-0.5 = 416 mum) for Ala-Asp compared with Ala-Ala (K-0.5 = 54 mum) and Ala-Lys (K-0.5 = 112 mum). Transient expression of AtPTR1/GFP fusion proteins in tobacco protoplasts showed that AtPTR1 is localized at the plasma membrane. In addition, transgenic plants expressing the beta-glucuronidase (uidA) gene under control of the AtPTR1 promoter demonstrated expression in the vascular tissue throughout the plant, indicative of a role in long-distance transport of di- and tripeptides.

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Expansins are members of a multigene family of extracellular proteins, which increase cell wall extensibility in vitro and thus are thought to be involved in cell expansion. The major significance of the presence of this large gene family may be that distinctly expressed genes can independently regulate cell expansion in place and time. Here we report on LeExp9, a new expansin gene from tomato, and compare its expression in the shoot tip with that of LeExp2 and LeExp18. LeExp18 gene is expressed in very young tissues of the tomato shoot apex and the transcript levels are upregulated in the incipient primordium. LeExp2 mRNA accumulated in more mature tissues and transcript levels correlated with cell elongation in the elongation zone. In situ hybridization experiments showed a uniform distribution of LeExp9 mRNA in submeristematic tissues. When gibberellin-deficient mutant tomatoes that lacked elongation of the internodes were treated with gibberellin, the phenotypic rescue was correlated with an increase in LeExp9 and LeExp2, but not LeExp18 levels. We propose that the three expansins define three distinct growing zones in the shoot tip. In the meristem proper, gibberellin-independent LeExp18 mediates the cell expansion that accompanies cell division. In the submeristematic zone, LeExp9 mediates cell expansion at a time that cell division comes to a halt. LeExp9 expression requires gibberellin but the hormone is not normally limiting. Finally, LeExp2 mediates cell elongation in young stem tissue. LeExp2 expression is limited by the available gibberellin. These data suggest that regulation of cell wall extensibility is controlled, at least in part, by differential regulation of expansin genes.

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Plant shoot development depends on the perpetuation of a group of undifferentiated cells in the shoot apical meristem (SAM). In the Petunia mutant hairy meristem (ham), shoot meristems differentiate postembryonically as continuations of the subtending stem. HAM encodes a putative transcription factor of the GRAS family, which acts non-cell-autonomously from L3-derived tissue of lateral organ primordia and stem provasculature. HAM acts in parallel with TERMINATOR (PhWUSCHEL) and is required for continued cellular response to TERMINATOR and SHOOTMERISTEMLESS (PhSTM). This reveals a novel mechanism by which signals from differentiating tissues extrinsically control stem cell fate in the shoot apex.

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The molecular regulation of horn growth in ruminants is still poorly understood. To investigate this process, we collected 1019 hornless (polled) animals from different cattle breeds. High-density SNP genotyping confirmed the presence of two different polled associated haplotypes in Simmental and Holstein cattle co-localized on BTA 1. We refined the critical region of the Simmental polled mutation to 212 kb and identified an overlapping region of 932 kb containing the Holstein polled mutation. Subsequently, whole genome sequencing of polled Simmental and Holstein cows was used to determine polled associated genomic variants. By genotyping larger cohorts of animals with known horn status we found a single perfectly associated insertion/deletion variant in Simmental and other beef cattle confirming the recently published possible Celtic polled mutation. We identified a total of 182 sequence variants as candidate mutations for polledness in Holstein cattle, including an 80 kb genomic duplication and three SNPs reported before. For the first time we showed that hornless cattle with scurs are obligate heterozygous for one of the polled mutations. This is in contrast to published complex inheritance models for the bovine scurs phenotype. Studying differential expression of the annotated genes and loci within the mapped region on BTA 1 revealed a locus (LOC100848215), known in cow and buffalo only, which is higher expressed in fetal tissue of wildtype horn buds compared to tissue of polled fetuses. This implicates that the presence of this long noncoding RNA is a prerequisite for horn bud formation. In addition, both transcripts associated with polledness in goat and sheep (FOXL2 and RXFP2), show an overexpression in horn buds confirming their importance during horn development in cattle.

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AIM It is unknown how the heart distinguishes various overloads, such as exercise or hypertension, causing either physiological or pathological hypertrophy. We hypothesize that alpha-calcitonin-gene-related peptide (αCGRP), known to be released from contracting skeletal muscles, is key at this remodelling. METHODS The hypertrophic effect of αCGRP was measured in vitro (cultured cardiac myocytes) and in vivo (magnetic resonance imaging) in mice. Exercise performance was assessed by determination of maximum oxygen consumption and time to exhaustion. Cardiac phenotype was defined by transcriptional analysis, cardiac histology and morphometry. Finally, we measured spontaneous activity, body fat content, blood volume, haemoglobin mass and skeletal muscle capillarization and fibre composition. RESULTS While αCGRP exposure yielded larger cultured cardiac myocytes, exercise-induced heart hypertrophy was completely abrogated by treatment with the peptide antagonist CGRP(8-37). Exercise performance was attenuated in αCGRP(-/-) mice or CGRP(8-37) treated wild-type mice but improved in animals with higher density of cardiac CGRP receptors (CLR-tg). Spontaneous activity, body fat content, blood volume, haemoglobin mass, muscle capillarization and fibre composition were unaffected, whereas heart index and ventricular myocyte volume were reduced in αCGRP(-/-) mice and elevated in CLR-tg. Transcriptional changes seen in αCGRP(-/-) (but not CLR-tg) hearts resembled maladaptive cardiac phenotype. CONCLUSIONS Alpha-calcitonin-gene-related peptide released by skeletal muscles during exercise is a hitherto unrecognized effector directing the strained heart into physiological instead of pathological adaptation. Thus, αCGRP agonists might be beneficial in heart failure patients.

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BACKGROUND TMPRSS2-ERG gene fusion is the most frequent genetic alteration in prostate cancer. However, information about its distribution in lymph node positive prostate cancers and the prognostic significance in these advanced tumors is unknown. METHODS Gene fusion status was determined by fluorescence in situ hybridization on a tissue-microarray constructed from 119 hormone-naïve nodal positive, surgically treated prostate cancers containing samples from the primary tumors and corresponding lymph node metastases. Data were correlated with various tumor features (Gleason score, stage, cancer volume, nodal tumor burden) and biochemical recurrence-free, disease-specific, and overall survival. RESULTS TMPRSS2-ERG fusion was detected in 43.5% of the primary tumors. Conversely, only 29.9% of the metastasizing components showed the fusion. Concordance in TMPRSS2-ERG status between primary tumors and metastases was 70.9% (Kappa 0.39); 20.9% and 8.1% of the patients showed the mutation solely in their primary tumors and metastases, respectively. TMPRSS2-ERG fusion was not correlated with specific histopathological tumor features but predicted favorable biochemical recurrence-free, disease-specific and overall survival independently when present in the primary tumor (P < 0.05 each). CONCLUSION TMPRSS2-ERG fusion is more frequent in primary prostate cancer than in corresponding metastases suggesting no selection of fusion-positive cells in the metastatic process. The gene fusion in primary tumors independently predicts favorable outcome.

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BACKGROUND & AIMS: The genetic background of alcoholic liver diseases and their complications are increasingly recognized. A common polymorphism in the neurocan (NCAN) gene, which is known to be expressed in neuronal tissue, has been identified as a risk factor for non-alcoholic fatty liver disease (NAFLD). We investigated if this polymorphism may also be related to alcoholic liver disease (ALD) and hepatocellular carcinoma (HCC). METHODS: We analysed the distribution of the NCAN rs2228603 genotypes in 356 patients with alcoholic liver cirrhosis, 126 patients with alcoholic HCC, 382 persons with alcohol abuse without liver damage, 362 healthy controls and in 171 patients with hepatitis C virus (HCV) associated HCC. Furthermore, a validation cohort of 229 patients with alcoholic cirrhosis (83 with HCC) was analysed. The genotypes were determined by LightSNiP assays. The expression of NCAN was studied by RT-PCR and immunofluorescence microscopy. RESULTS: The frequency of the NCAN rs2228603 T allele was significantly increased in patients with HCC due to ALD (15.1%) compared to alcoholic cirrhosis without HCC (9.3%), alcoholic controls (7.2%), healthy controls (7.9%), and HCV associated HCC (9.1%). This finding was confirmed in the validation cohort (15.7% vs. 6.8%, OR=2.53; 95%CI: 1.36-4.68; p=0.0025) and by multivariate analysis (OR=1.840; 95%CI: 1.22-2.78; p=0.004 for carriage of the rs2228603 T allele). In addition, we identified and localised NCAN expression in human liver. CONCLUSIONS: NCAN is not only expressed in neuronal tissue, but also in the liver. Its rs2228603 polymorphism is a risk factor for HCC in ALD, but not in HCV infection.

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BACKGROUND Flavobacterium psychrophilum is the agent of Bacterial Cold Water Disease and Rainbow Trout Fry Syndrome, two diseases leading to high mortality. Pathogen detection is mainly carried out using cultures and more rapid and sensitive methods are needed. RESULTS We describe a qPCR technique based on the single copy gene β' DNA-dependent RNA polymerase (rpoC). Its detection limit was 20 gene copies and the quantification limit 103 gene copies per reaction. Tests on spiked spleens with known concentrations of F. psychrophilum (106 to 101 cells per reaction) showed no cross-reactions between the spleen tissue and the primers and probe. Screening of water samples and spleens from symptomless and infected fishes indicated that the pathogen was already present before the outbreaks, but F. psychrophilum was only quantifiable in spleens from diseased fishes. CONCLUSIONS This qPCR can be used as a highly sensitive and specific method to detect F. psychrophilum in different sample types without the need for culturing. qPCR allows a reliable detection and quantification of F. psychrophilum in samples with low pathogen densities. Quantitative data on F. psychrophilum abundance could be useful to investigate risk factors linked to infections and also as early warning system prior to potential devastating outbreak.

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Binding of CD47 to signal regulatory protein alpha (SIRPα), an inhibitory receptor, negatively regulates phagocytosis. In acute myeloid leukemia (AML), CD47 is overexpressed on peripheral blasts and leukemia stem cells and inversely correlates with survival. Aim of the study was to investigate the correlation between CD47 protein expression by immunohistochemistry (IHC) in a bone marrow (BM) tissue microarray (TMA) and clinical outcome in AML patients. CD47 staining on BM leukemia blasts was scored semi-quantitatively and correlated with clinical parameters and known prognostic factors in AML. Low (scores 0-2) and high (score 3) CD47 protein expression were observed in 75% and 25% of AML patients. CD47 expression significantly correlated with percentage BM blast infiltration and peripheral blood blasts. Moreover, high CD47 expression was associated with nucleophosmin (NPM1) gene mutations. In contrast, CD47 expression did not significantly correlate with overall or progression free survival or response to therapy. In summary, a BM TMA permits rapid and reproducible semi-quantitative analysis of CD47 protein expression by IHC. While CD47 expression on circulating AML blasts has been shown to be a negative prognostic marker for a very defined population of AML patients with NK AML, CD47 expression on AML BM blasts is not.

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We have cloned the complete coding region of the porcine TNFSF10 gene. The porcine TNFSF10 cDNA has an ORF of 870 nucleotides and shares 85% identity with human TNFSF10, and 75% and 72% identity with rat and mouse Tnfsf10 coding sequences, respectively. The deduced porcine TNFSF10 protein consists of 289 amino acids with the calculated molecular mass of 33.5 kDa and a predicted pI of 8.15. The amino acid sequence similarities correspond to 86, 72 and 70% when compared with human, rat and mouse sequences, respectively. Northern blot analysis detected TNFSF10-specific transcripts (approximately 1.7 kb) in various organs of a 10-week-old pig, suggesting ubiquitous expression. Real-time RT-PCR studies of various organs from fetal (days 73 and 98) and postnatal stages (two weeks, eight months) demonstrated developmental and tissue-specific regulation of TNFSF10 mRNA abundance. The chromosomal location of the porcine TNFSF10 gene was determined by FISH of a specific BAC clone to metaphase chromosomes. This TNFSF10 BAC clone has been assigned to SSC13q34-->q36. Additionally, the localization of the TNFSF10 gene was verified by RH mapping on the porcine IMpRH panel.

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The epigenetic influence of maternal cells on the development of their progeny has long been studied in various eukaryotes. Multicellular organisms usually provide their zygotes not only with nutrients but also with functional elements required for proper development, such as coding and non-coding RNAs. These maternally deposited RNAs exhibit a variety of functions, from regulating gene expression to assuring genome integrity. In ciliates, such as Paramecium these RNAs participate in the programming of large-scale genome reorganization during development, distinguishing germline-limited DNA, which is excised, from somatic-destined DNA. Only a handful of proteins playing roles in this process have been identified so far, including typical RNAi-derived factors such as Dicer-like and Piwi proteins. Here we report and characterize two novel proteins, Pdsg1 and Pdsg2 (Paramecium protein involved in Development of the Somatic Genome 1 and 2), involved in Paramecium genome reorganization. We show that these proteins are necessary for the excision of germline-limited DNA during development and the survival of sexual progeny. Knockdown of PDSG1 and PDSG2 genes affects the populations of small RNAs known to be involved in the programming of DNA elimination (scanRNAs and iesRNAs) and chromatin modification patterns during development. Our results suggest an association between RNA-mediated trans-generational epigenetic signal and chromatin modifications in the process of Paramecium genome reorganization.

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The objective of the present review was to summarize the evidence available on the temporal sequence of hard and soft tissue healing around titanium dental implants in animal models and in humans. A search was undertaken to find animal and human studies reporting on the temporal dynamics of hard and soft tissue integration of titanium dental implants. Moreover, the influence of implant surface roughness and chemistry on the molecular mechanisms associated with osseointegration was also investigated. The findings indicated that the integration of titanium dental implants into hard and soft tissue represents the result of a complex cascade of biological events initiated by the surgical intervention. Implant placement into alveolar bone induces a cascade of healing events starting with clot formation and continuing with the maturation of bone in contact with the implant surface. From a genetic point of view, osseointegration is associated with a decrease in inflammation and an increase in osteogenesis-, angiogenesis- and neurogenesis-associated gene expression during the early stages of wound healing. The attachment and maturation of the soft tissue complex (i.e. epithelium and connective tissue) to implants becomes established 6-8 weeks following surgery. Based on the findings of the present review it can be concluded that improved understanding of the mechanisms associated with osseointegration will provide leads and targets for strategies aimed at enhancing the clinical performance of titanium dental implants.