708 research outputs found

    Ofd1 Controls Dorso-Ventral Patterning and Axoneme Elongation during Embryonic Brain Development.

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    Oral-facial-digital type I syndrome (OFDI) is a human X-linked dominant-male-lethal developmental disorder caused by mutations in the OFD1 gene. Similar to other inherited disorders associated to ciliary dysfunction OFD type I patients display neurological abnormalities. We characterized the neuronal phenotype that results from Ofd1 inactivation in early phases of mouse embryonic development and at post-natal stages. We determined that Ofd1 plays a crucial role in forebrain development, and in particular, in the control of dorso-ventral patterning and early corticogenesis. We observed abnormal activation of Sonic hedgehog (Shh), a major pathway modulating brain development. Ultrastructural studies demonstrated that early Ofd1 inactivation results in the absence of ciliary axonemes despite the presence of mature basal bodies that are correctly orientated and docked. Ofd1 inducible-mediated inactivation at birth does not affect ciliogenesis in the cortex, suggesting a developmental stage-dependent role for a basal body protein in ciliogenesis. Moreover, we showed defects in cytoskeletal organization and apical-basal polarity in Ofd1 mutant embryos, most likely due to lack of ciliary axonemes. Thus, the present study identifies Ofd1 as a developmental disease gene that is critical for forebrain development and ciliogenesis in embryonic life, and indicates that Ofd1 functions after docking and before elaboration of the axoneme in vivo

    OPTIMAL MANAGEMENT OF FLEXIBILITY SERVICES IN LV DISTRIBUTION GRIDS

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    With the increase of intermittent and not programmable generation from clean resources and of new demand tech-nologies characterized by high coincident peaks (like heat pumps, induction cookers, etc.) the management of avail-able flexibility in distribution grids to provide network ser-vices has become very important. The paper proposes an optimization model to manage the flexibility in the LV net-work to both solve local network problems and aggregate the available flexibility for use at higher levels while sat-isfying LV network constraints. The model is a tool for the LV DSOs to optimally manage the flexibilities and its fea-tures are illustrated on the IEEE 123 test feeder

    Construction of a YAC contig covering human chromosome 6p22

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    A contig covering human chromosome 6p22 that consists of 134 YAC clones aligned based on the presence/absence of 52 DNA markers is presented. This contig overlaps with the 6p23 contig at its telomeric end and with the 6p21.3 contig at its centromeric end. The order of loci within the contig resolves the relative positions of several genetically mapped markers. Among the additional markers used here, there are eight novel PCR assays. The 12 known genes and anonymous ESTs located within the contig establish a first step toward a transcriptional map of this region. The instability of YAC clones observed during this work is also discussed. (C) 1996 Academic Press, Inc

    Oral-Facial-Digital syndrome Type I cells exhibit impaired DNA repair; unanticipated consequences of defective OFD1 outside of the cilia network

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    Defects in OFD1 underlie the clinically complex ciliopathy, Oral-Facial-Digital syndrome Type I (OFD Type I). Our understanding of the molecular, cellular and clinical consequences of impaired OFD1 originate from its characterised roles at the centrosome/basal body/cilia network. Nonetheless, the first described OFD1 interactors were components of the TIP60 histone acetyltransferase complex. We find that OFD1 can also localise to chromatin and its reduced expression is associated with mislocalization of TIP60 in patient-derived cell lines. TIP60 plays important roles in controlling DNA repair. OFD Type I cells exhibit reduced histone acetylation and altered chromatin dynamics in response to DNA double strand breaks (DSBs). Furthermore, reduced OFD1 impaired DSB repair via homologous recombination repair (HRR). OFD1 loss also adversely impacted upon the DSB-induced G2-M checkpoint, inducing a hypersensitive and prolonged arrest. Our findings show that OFD Type I patient cells have pronounced defects in the DSB-induced histone modification, chromatin remodelling and DSB-repair via HRR; effectively phenocopying loss of TIP60. These data extend our knowledge of the molecular and cellular consequences of impaired OFD1, demonstrating that loss of OFD1 can negatively impact upon important nuclear events; chromatin plasticity and DNA repair

    Impact of the number of comorbidities on cardiac sympathetic derangement in patients with reduced ejection fraction heart failure

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    Introduction Heart failure (HF) is frequently associated with comorbidities. 123I-metaiodobenzylguanidine (123I-mIBG) imaging constitutes an effective tool to measure cardiac adrenergic innervation and to improve prognostic stratification in HF patients, including the risk of major arrhythmic events. Although comorbidities have been individually associated with reduced cardiac adrenergic innervation, thus suggesting increased arrhythmic risk, very comorbid HF patients seem to be less likely to experience fatal arrhythmias. We evaluated the impact of the number of comorbidities on cardiac adrenergic innervation, assessed through 123I-mIBG imaging, in patients with systolic HF. Methods Patients with systolic HF underwent clinical examination, transthoracic echocardiography and cardiac 123I-mIBG scintigraphy. The presence of 7 comorbidities/conditions (smoking, chronic obstructive pulmonary disease, diabetes mellitus, peripheral artery disease, atrial fibrillation, chronic ischemic heart disease and chronic kidney disease) was documented in the overall study population. Results The study population consisted of 269 HF patients with a mean age of 66±11 years, a left ventricular ejection fraction (LVEF) of 31±7%, and 153 (57%) patients presented ≥3 comorbidities. Highly comorbid patients presented a reduced late heart to mediastinum (H/M) ratio, while no significant differences emerged in terms of early H/M ratio and washout rate. Multiple regression analysis revealed that the number of comorbidities was not associated with mIBG parameters of cardiac denervation, which were correlated with age, body mass index and LVEF. Conclusion In systolic HF patients, the number of comorbidities is not associated with alterations in cardiac adrenergic innervation. These results are consistent with the observation that very comorbid HF patients suffer lower risk of sudden cardiac death

    miR-181a/b downregulation exerts a protective action on mitochondrial disease models.

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    Mitochondrial diseases (MDs) are a heterogeneous group of devastating and often fatal disorders due to defective oxidative phosphorylation. Despite the recent advances in mitochondrial medicine, effective therapies are still not available for these conditions. Here, we demonstrate that the microRNAs miR-181a and miR-181b (miR-181a/b) regulate key genes involved in mitochondrial biogenesis and function and that downregulation of these miRNAs enhances mitochondrial turnover in the retina through the coordinated activation of mitochondrial biogenesis and mitophagy. We thus tested the effect of miR-181a/b inactivation in different animal models of MDs, such as microphthalmia with linear skin lesions and Leber\u27s hereditary optic neuropathy. We found that miR-181a/b downregulation strongly protects retinal neurons from cell death and significantly ameliorates the disease phenotype in all tested models. Altogether, our results demonstrate that miR-181a/b regulate mitochondrial homeostasis and that these miRNAs may be effective gene-independent therapeutic targets for MDs characterized by neuronal degeneration

    Generation and Characterization of a Tumor Stromal Microenvironment and Analysis of Its Interplay with Breast Cancer Cells: An In Vitro Model to Study Breast Cancer-Associated Fibroblast Inactivation

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    Breast cancer-associated fibroblasts (BCAFs), the most abundant non-cancer stromal cells of the breast tumor microenvironment (TME), dramatically sustain breast cancer (BC) progression by interacting with BC cells. BCAFs, as well as myofibroblasts, display an up regulation of activation and inflammation markers represented by α-smooth muscle actin (α-SMA) and cyclooxygenase 2 (COX-2). BCAF aggregates have been identified in the peripheral blood of metastatic BC patients. We generated an in vitro stromal model consisting of human primary BCAFs grown as monolayers or 3D cell aggregates, namely spheroids and reverted BCAFs, obtained from BCAF spheroids reverted to 2D cell adhesion growth after 216 h of 3D culture. We firstly evaluated the state of activation and inflammation and the mesenchymal status of the BCAF monolayers, BCAF spheroids and reverted BCAFs. Then, we analyzed the MCF-7 cell viability and migration following treatment with conditioned media from the different BCAF cultures. After 216 h of 3D culture, the BCAFs acquired an inactivated phenotype, associated with a significant reduction in α-SMA and COX-2 protein expression. The deactivation of the BCAF spheroids at 216 h was further confirmed by the cytostatic effect exerted by their conditioned medium on MCF-7 cells. Interestingly, the reverted BCAFs also retained a less activated phenotype as indicated by α-SMA protein expression reduction. Furthermore, the reverted BCAFs exhibited a reduced pro-tumor phenotype as indicated by the anti-migratory effect exerted by their conditioned medium on MCF-7 cells. The deactivation of BCAFs without drug treatment is possible and leads to a reduced capability of BCAFs to sustain BC progression in vitro. Consequently, this study could be a starting point to develop new therapeutic strategies targeting BCAFs and their interactions with cancer cells
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