14 research outputs found

    Cystic adenomatoid malformations are induced by localized FGF10 overexpression in fetal rat lung

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    Fibroblast growth factor-10 (FGF10) is a mesenchymal growth factor, involved in epithelial and mesenchymal interactions during lung branching morphogenesis. In the present work, FGF10 overexpression was transiently induced in a temporally and spatially restricted manner, during the pseudoglandular or canalicular stages of rat lung development, by trans-uterine ultrasound-guided intraparenchymal microinjections of adenoviral vector encoding the rfgf10 transgene. The morphologic and histologic classification of the resulting malformations were dependent upon developmental stage and location. Overexpression of FGF10 restricted to the proximal tracheobronchial tree during the pseudoglandular phase resulted in large cysts lined by tall columnar epithelium composed primarily of Clara cells with a paucity of Type II pneumocytes, resembling bronchiolar type epithelium. In contrast, FGF10 overexpression in the distal lung parenchyma during the canalicular phase resulted in small cysts lined by cuboidal epithelial cells composed of primarily Type II pneumocytes resembling acinar epithelial differentiation. The cystic malformations induced by FGF10 overexpression appear to closely recapitulate the morphology and histology of the spectrum of human congenital cystic adenomatoid malformation (CCAM). These findings support a role for FGF10 in the induction of human CCAM and provide further mechanistic insight into the role of FGF10 in normal and abnormal lung development.This project was in part funded by proceeds from the Ruth and Tristram C. Colket Jr. Chair in Pediatric Surgery (A.W.F.), and the Fundação para a Ciência e Tecnologia (POCI/SAUOBS/56428/2004). S.G. was supported by FCT grant ref. SFRH/BD/15260/2004

    Multiple independent L-gulonolactone oxidase (GULO) gene losses and vitamin C synthesis reacquisition events in non-Deuterostomian animal species

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    Background: L-ascorbate (Vitamin C) is an important antioxidant and co-factor in eukaryotic cells, and in mammals it is indispensable for brain development and cognitive function. Vertebrates usually become L-ascorbate auxothrophs when the last enzyme of the synthetic pathway, an L-gulonolactone oxidase (GULO), is lost. Since Protostomes were until recently thought not to have a GULO gene, they were considered to be auxothrophs for Vitamin C. Results: By performing phylogenetic analyses with tens of non-Bilateria and Protostomian genomes, it is shown, that a GULO gene is present in the non-Bilateria Placozoa, Myxozoa (here reported for the first time) and Anthozoa groups, and in Protostomians, in the Araneae family, the Gastropoda class, the Acari subclass (here reported for the first time), and the Priapulida, Annelida (here reported for the first time) and Brachiopoda phyla lineages. GULO is an old gene that predates the separation of Animals and Fungi, although it could be much older. We also show that within Protostomes, GULO has been lost multiple times in large taxonomic groups, namely the Pancrustacea, Nematoda, Platyhelminthes and Bivalvia groups, a pattern similar to that reported for Vertebrate species. Nevertheless, we show that Drosophila melanogaster seems to be capable of synthesizing L-ascorbate, likely through an alternative pathway, as recently reported for Caenorhabditis elegans. Conclusions: Non-Bilaterian and Protostomians seem to be able to synthesize Vitamin C either through the conventional animal pathway or an alternative pathway, but in this animal group, not being able to synthesize L-ascorbate seems to be the exception rather than the ruleXunta de Galicia | Ref. ED431C2018/55-GRCNorte 2020 y FEDER | Ref. Norte-01-0145-FEDER-000008Xunta de Galicia | Ref. ED481B 2016/068–

    Targeted gene transfer to fetal rat lung interstitium by ultrasound-guided intrapulmonary injection

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    In utero gene transfer to the developing lung may have clinical or research applications. In this study, we developed a new method for specifically targeting the fetal rat lung with adeno and lentiviral vectors encoding the enhanced green fluorescence protein (EGFP) marker gene at E15.5 using ultrasound biomicroscopy (UBM). Survival rate, morphometric parameters, viral biodistribution, and lung transduction efficiency were analyzed and compared to the intra-amniotic route of administration. Expression of EGFP started as early as 24 and 72 h after the injection of adenoviral and lentiviral vectors, respectively. Both vectors transduced lung parenchyma with gene expression limited to interstitial cells of the injected region, in contrast to intra-amniotic injection, which targeted the pulmonary epithelium. Expression of EGFP was most intense at E18.5 and E21.5 for adenoviral and lentiviral vectors, respectively. In contrast to lentivirus, adenoviral expression significantly declined until final analysis at 1 week of age. This study demonstrates the feasibility of targeting the fetal rat lung interstitium with viral vectors under UBM guidance during the pseudoglandular stage. This model system may facilitate in vivo studies of dynamic lung morphogenesis and could provide insight into the efficacy of prenatal gene transfer strategies for treatment of specific lung disorders.FCT Grant (SFRH/BD/15260/2004) on behalf of the FCT Grant POCI/SAU-OBS/56428/200

    Nontoxic glasses: Preparation, structural, electrical and biological properties

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    The authors are grateful by the FEDER funds through the COMPETE 2020 Program and National Funds through FCT?Portuguese Foundation for Science and Technology under the project UID/CTM/50025/2013, UCIBIO, REQUIMTE UID/Multi/04378/2013, and DENTALBLAST project (ref. n? 17956).Bacterial infections affect about 1 in 5 patients who receive a dental implant within 5 years of surgery. To avoid the implant rejection it is necessary for the development of innovative biomaterials, with addition or substitution of the ions, for implant coatings that promote a strong bond with the new host bone and antibacterial action. The objective of this work was to synthesize a bioactive glass with different silver concentrations to evaluate their antibacterial performance. The glasses were synthesized with up to 2% silver content by melt-quenching. Structural, morphological, biological, and electrical properties of all samples were studied. The biological behavior was evaluated through cytotoxicity tests and antibacterial activity. The structural analysis shows that the introduction of silver do not promote significant changes, not altering the advantageous properties of the bioglass of the bioglass. It was verified that the glasses with a silver content from 0.5% to 2%, completely prevented the growth of both Staphylococcus aureus and Escherichia coli while being nontoxic toward mammalian cells. Therefore, these bioglasses are promising materials to be used in the production of dental implants with antimicrobial activity.authorsversionpublishe

    Identification of a DNA-binding site for the transcription factor Haa1, required for Saccharomyces cerevisiae response to acetic acid stress

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    The transcription factor Haa1 is the main player in reprogramming yeast genomic expression in response to acetic acid stress. Mapping of the promoter region of one of the Haa1-activated genes, TPO3, allowed the identification of an acetic acid responsive element (ACRE) to which Haa1 binds in vivo. The in silico analysis of the promoter regions of the genes of the Haa1-regulon led to the identification of an Haa1-responsive element (HRE) 5′-GNN(G/C)(A/C)(A/G)G(A/G/C)G-3′. Using surface plasmon resonance experiments and electrophoretic mobility shift assays it is demonstrated that Haa1 interacts with high affinity (KD of 2 nM) with the HRE motif present in the ACRE region of TPO3 promoter. No significant interaction was found between Haa1 and HRE motifs having adenine nucleotides at positions 6 and 8 (KD of 396 and 6780 nM, respectively) suggesting that Haa1p does not recognize these motifs in vivo. A lower affinity of Haa1 toward HRE motifs having mutations in the guanine nucleotides at position 7 and 9 (KD of 21 and 119 nM, respectively) was also observed. Altogether, the results obtained indicate that the minimal functional binding site of Haa1 is 5′-(G/C)(A/C)GG(G/C)G-3′. The Haa1-dependent transcriptional regulatory network active in yeast response to acetic acid stress is proposed

    Snapshot of viral infections in wild carnivores reveals ubiquity of parvovirus and susceptibility of Egyptian mongoose to feline panleukopenia virus

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    The exposure of wild carnivores to viral pathogens, with emphasis on parvovirus (CPV/FPLV), was assessed based on the molecular screening of tissue samples from 128 hunted or accidentally road-killed animals collected in Portugal from 2008 to 2011, including Egyptian mongoose (Herpestes ichneumon, n = 99), red fox (Vulpes vulpes, n = 19), stone marten (Martes foina, n = 3), common genet (Genetta genetta, n = 3) and Eurasian badger (Meles meles, n = 4). A high prevalence of parvovirus DNA (63%) was detected among all surveyed species, particularly in mongooses (58%) and red foxes (79%), along with the presence of CPV/FPLV circulating antibodies that were identified in 90% of a subset of parvovirus-DNA positive samples. Most specimens were extensively autolysed, restricting macro and microscopic investigations for lesion evaluation. Whenever possible to examine, signs of active disease were not present, supporting the hypothesis that the parvovirus vp2 gene fragments detected by real-time PCR possibly correspond to viral DNA reminiscent from previous infections. The molecular characterization of viruses, based on the analysis of the complete or partial sequence of the vp2 gene, allowed typifying three viral strains of mongoose and four red fox’s as feline panleukopenia virus (FPLV) and one stone marten’s as newCPV-2b type. The genetic similarity found between the FPLV viruses from free-ranging and captive wild species originated in Portugal and publicly available comparable sequences, suggests a closer genetic relatedness among FPLV circulating in Portugal. Although the clinical and epidemiological significance of infection could not be established, this study evidences that exposure of sympatric wild carnivores to parvovirus is common and geographically widespread, potentially carrying a risk to susceptible populations at the wildlife-domestic interface and to threatened species, such as the wildcat (Felis silvestris) and the critically endangered Iberian lynx (Lynx pardinus).publishe

    Cobalt Ferrite Synthesized Using a Biogenic Sol–Gel Method for Biomedical Applications

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    Cancer is one of the leading causes of death worldwide. Conventional treatments such as surgery, chemotherapy, and radiotherapy have limitations and severe side effects. Magnetic hyperthermia (MH) is an alternative method that can be used alone or in conjunction with chemotherapy or radiotherapy to treat cancer. Cobalt ferrite particles were synthesized using an innovative biogenic sol–gel method with powder of coconut water (PCW). The obtained powders were subjected to heat treatments between 500 °C and 1100 °C. Subsequently, they were characterized by thermal, structural, magnetic, and cytotoxic analyses to assess their suitability for MH applications. Through X-ray diffraction and Raman spectroscopy, it was possible to confirm the presence of the pure phase of CoFe2O4 in the sample treated at 1100 °C, exhibiting a saturation magnetization of 84 emu/g at 300 K and an average grain size of 542 nm. Furthermore, the sample treated at 1100 °C showed a specific absorption rate (SAR) of 3.91 W/g, and at concentrations equal to or below 5 mg/mL, is non-cytotoxic, being the most suitable for biomedical applications

    Metabolic cross-feeding in imbalanced diets allows gut microbes to improve reproduction and alter host behaviour

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    In the fly Drosophila melanogaster commensal bacteria and dietary essential amino acids control food choice behavior. Here, by using chemically defined diets and metabolomics, the authors show that Acetobacter pomorum (Ap) and Lactobacilli plantarum (Lp) engage in a mutualistic metabolic relationship to overcome detrimental diets, and identify Ap as the bacterium altering the host’s feeding decisions
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