Mirk/Dyrk1B controls ventral spinal cord development via Shh pathway.

Cross-talk between Mirk/Dyrk1B kinase and Sonic hedgehog (Shh)/Gli pathway affects physiology and pathology. Here, we reveal a novel role for Dyrk1B in regulating ventral progenitor and neuron subtypes in the embryonic chick spinal cord (SC) via the Shh pathway. Using in ovo gain-and-loss-of-function approaches at E2, we report that Dyrk1B affects the proliferation and differentiation of neuronal progenitors at E4 and impacts on apoptosis specifically in the motor neuron (MN) domain. Especially, Dyrk1B overexpression decreases the numbers of ventral progenitors, MNs, and V2a interneurons, while the pharmacological inhibition of endogenous Dyrk1B kinase activity by AZ191 administration increases the numbers of ventral progenitors and MNs. Mechanistically, Dyrk1B overexpression suppresses Shh, Gli2 and Gli3 mRNA levels, while conversely, Shh, Gli2 and Gli3 transcription is increased in the presence of Dyrk1B inhibitor AZ191 or Smoothened agonist SAG. Most importantly, in phenotype rescue experiments, SAG restores the Dyrk1B-mediated dysregulation of ventral progenitors. Further at E6, Dyrk1B affects selectively the medial lateral motor neuron column (LMCm), consistent with the expression of Shh in this region. Collectively, these observations reveal a novel regulatory function of Dyrk1B kinase in suppressing the Shh/Gli pathway and thus affecting ventral subtypes in the developing spinal cord. These data render Dyrk1B a possible therapeutic target for motor neuron diseases.

A global cloud free pixel- based image composite from Sentinel-2 data.

Large-scale land cover classification from satellite imagery is still a challenge due to the big volume of data to be processed, to persistent cloud-cover in cloud-prone areas as well as seasonal artefacts that affect spatial homogeneity. Sentinel-2 times series from Copernicus Earth Observation program offer a great potential for fine scale land cover mapping thanks to high spatial and temporal resolutions, with a decametric resolution and five-day repeat time. However, the selection of best available scenes, their download together with the requirements in terms of storage and computing resources pose restrictions for large-scale land cover mapping. The dataset presented in this paper corresponds to global cloud-free pixel based composite created from the Sentinel-2 data archive (Level L1C) available in Google Earth Engine for the period January 2017- December 2018. The methodology used for generating the image composite is described and the metadata associated with the 10 m resolution dataset is presented. The data with a total volume of 15 TB is stored on the Big Data platform of the Joint Research Centre. It can be downloaded per UTM grid zone, loaded into GIS clients and displayed easily thanks to pre-computed overviews.

GAD65 epitope mapping and search for novel autoantibodies in GAD-associated neurological disorders.

Antibodies against Glutamic-acid-decarboxylase (GAD65) are seen in various CNS excitability disorders including stiff-person syndrome, cerebellar ataxia, encephalitis and epilepsy. To explore pathogenicity, we examined whether distinct epitope specificities or other co-existing antibodies may account for each disorder. The epitope recognized by all 27 tested patients, irrespective of clinical phenotype, corresponded to the catalytic core of GAD. No autoantibodies against known GABAergic antigens were found. In a screen for novel specificities using live hippocampal neurons, three epilepsy patients, but no other, were positive. We conclude that no GAD-specific epitope defines any neurological syndrome but other antibody specificities may account for certain phenotypes.

Corticotropin-releasing hormone exerts direct effects on neuronal progenitor cells: implications for neuroprotection.

Neurogenesis during embryonic and adult life is tightly regulated by a network of transcriptional, growth and hormonal factors. Emerging evidence indicates that activation of the stress response, via the associated glucocorticoid increase, reduces neurogenesis and contributes to the development of adult diseases.As corticotrophin-releasing hormone (CRH) or factor is the major mediator of adaptive response to stressors, we sought to investigate its involvement in this process. Accordingly, we found that CRH could reverse the damaging effects of glucocorticoid on neural stem/progenitor cells (NS/PCs), while its genetic deficiency results in compromised proliferation and enhanced apoptosis during neurogenesis. Analyses in fetal and adult mouse brain revealed significant expression of CRH receptors in proliferating neuronal progenitors. Furthermore, by using primary cultures of NS/PCs, we characterized the molecular mechanisms and identified CRH receptor-1 as the receptor mediating the neuroprotective effects of CRH. Finally, we demonstrate the expression of CRH receptors in human fetal brain from early gestational age, in areas of active neuronal proliferation. These observations raise the intriguing possibility for CRH-mediated pharmacological applications in diseases characterized by altered neuronal homeostasis, including depression, dementia, neurodegenerative diseases, brain traumas and obesity.

Prox1 suppresses the proliferation of neuroblastoma cells via a dual action in p27-Kip1 and Cdc25A.

Neuroblastoma is a pediatric tumor that originates from precursor cells of the sympathetic nervous system with less than 40% long-term survival in children diagnosed with high-risk disease. These clinical observations underscore the need for novel insights in the mechanisms of malignant transformation and progression. Accordingly, it was recently reported that Prox1, a homeobox transcription regulator, is expressed in higher levels in human neuroblastoma with favorable prognosis. Consistently, we have recently shown that Prox1 exerts a strong antiproliferative effect on neural precursor cells during embryonic development. Thus, Prox1 is a candidate gene with a critical role in suppressing malignant neuroblastoma transformation. Here, we provide evidence that Prox1 strongly suppresses the proliferation of mouse and human neuroblastoma cell lines and blocks the growth of neuroblastoma tumors in SCID mice. Conversely, short hairpin RNA (shRNA) -mediated knockdown of basal Prox1 expression significantly induces proliferation, genomic instability and the ability of neuroblastoma cells to form tumors. Mechanistically, analysis of an inducible Prox1-overexpressing Neuro2A cell line indicates that Prox1 is sufficient to suppress CyclinD1, CyclinA and CyclinB1, consistent with a role in cell cycle arrest. Surprisingly, Prox1 strongly induces CyclinE1 expression in the same system despite its action on blocking cell cycle progression, which could account for the context dependent oncogenic function of Prox1. Most importantly, Prox1 was sufficient to decrease Cdc25A and induce p27-Kip1, but not p21-Cip1 or p53. By alleviating the Prox1 action in Cdc25A and p27-Kip1 expression, we were able to rescue its effect on cell cycle arrest. Together these data suggest that Prox1 negatively regulates neuroblastoma carcinogenesis through suppression of Cdc25A and induction of p27-Kip1 to counteract CyclinE1 overexpression and block cell cycle progression. Furthermore, these observations render Prox1 a candidate target for the treatment of neuroblastoma tumors.

Paclitaxel-ifosfamide-carboplatin combination chemotherapy regimen in advanced uterine and adnexal malignant mixed Mullerian tumours.

BACKGROUND: Malignant mixed Mullerian tumours (MMMTs) of the uterus and adnexa represent aggressive gynaecologic malignancies with a high rate of loco-regional and distant failure. For that reason, we evaluated the paclitaxel-ifosfamide-carboplatin (TICb) combination in patients with advanced MMMTs. METHODS: Female patients with advanced MMMTs, WHO-PS 0-2, no prior chemotherapy for systemic disease, unimpaired haemopoietic and organ function were eligible. Chemotherapy was administered at the following doses; paclitaxel: 175 mg m(-2) on day 1, ifosfamide: 2.0 g m(-2) day(-1)--days 1 and 2, and carboplatin at a target area under the curve 5 on day 2, with prophylactic G-CSF from day 3. RESULTS: Forty patients of a median age 61 (45-72) years, performance status 0-2 with advanced MMMTs of the uterus (n=34), tubes (n=2) or ovary (n=4) have entered and all were evaluable for response and toxicity. Responses were as follows: 27 out of 40 (67.5%) evaluable patients responded, with 11 complete responses and 16 partial responses, while 10 had stable disease, and 3 developed progressive disease. The median response duration was 9 months (range, 4-40 months), median progression-free survival 13 months (range, 3-42 months), while median overall survival 18 months (range, 4-48 months). Grade 3/4 neutropenia was recorded in 22 out of 40 (55%)--with 13 developing grade 4 (≤7 days) and 7 out of 40 (17.5%) of patients at least one episode of febrile neutropenia. CONCLUSION: In this study, it appears that the TICb combination, yielded important activity with manageable toxicity in females with advanced MMMTs warranting further randomised comparison with current standard regimens.

Mediastinal mass with Dysphagia in an elderly patient.

We report the use of endoscopic techniques for successful diagnosis in a case of atypical esophageal tuberculosis. Tuberculosis of the esophagus is an unusual presentation of this disease, having been estimated to occur in 0.15% of the people who die of tuberculosis. A few cases of possible primary tuberculous esophagitis have been described. This report describes a patient with dysphagia who appeared to have esophageal tuberculosis without HIV and in the absence of other signs of tuberculosis. The patient responded promptly to treatment with tuberculostatics.

In vivo chromatin remodeling by yeast ISWI homologs Isw1p and Isw2p.

Isw1p and Isw2p are budding yeast homologs of the Drosophila ISWI chromatin-remodeling ATPase. Using indirect-end-label and chromatin immunoprecipitation analysis, we show both independent and cooperative Isw1p- and Isw2p-mediated positioning of short nucleosome arrays in gene-regulatory elements at a variety of transcription units in vivo. We present evidence that both yeast ISWI complexes regulate developmental responses to starvation and that for Isw2p, recruitment by different DNA-binding proteins controls meiosis and haploid invasive growth.

Nonenzymatic synthesis of RNA and DNA oligomers on hexitol nucleic acid templates: the importance of the A structure.

Hexitol nucleic acid (HNA) is an analogue of DNA containing the standard nucleoside bases, but with a phosphorylated 1,5-anhydrohexitol backbone. HNA oligomers form duplexes having the nucleic acid A structure with complementary DNA or RNA oligomers. The HNA decacytidylate oligomer is an efficient template for the oligomerization of the 5'-phosphoroimidazolides of guanosine or deoxyguanosine. Comparison of the oligomerization efficiencies on HNA, RNA, and DNA decacytidylate templates under various conditions suggests strongly that only nucleic acid double helices with the A structure support efficient template-directed synthesis when 5'-phosphoroimidazolides of nucleosides are used as substrates.