110 research outputs found

    Angiopoietin 1 and integrin beta 1b are vital for zebrafish brain development

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    IntroductionAngiopoietin 1 (angpt1) is essential for angiogenesis. However, its role in neurogenesis is largely undiscovered. This study aimed to identify the role of angpt1 in brain development, the mode of action of angpt1, and its prime targets in the zebrafish brain.MethodsWe investigated the effects of embryonic brain angiogenesis and neural development using qPCR, in situ hybridization, microangiography, retrograde labeling, and immunostaining in the angpt1sa14264, itgb1bmi371, tekhu1667 mutant fish and transgenic overexpression of angpt1 in the zebrafish larval brains.ResultsWe showed the co-localization of angpt1 with notch, delta, and nestin in the proliferation zone in the larval brain. Additionally, lack of angpt1 was associated with downregulation of TEK tyrosine kinase, endothelial (tek), and several neurogenic factors despite upregulation of integrin beta 1b (itgb1b), angpt2a, vascular endothelial growth factor aa (vegfaa), and glial markers. We further demonstrated that the targeted angpt1sa14264 and itgb1bmi371 mutant fish showed severely irregular cerebrovascular development, aberrant hindbrain patterning, expansion of the radial glial progenitors, downregulation of cell proliferation, deficiencies of dopaminergic, histaminergic, and GABAergic populations in the caudal hypothalamus. In contrast to angpt1sa14264 and itgb1bmi371 mutants, the tekhu1667 mutant fish regularly grew with no apparent phenotypes. Notably, the neural-specific angpt1 overexpression driven by the elavl3 (HuC) promoter significantly increased cell proliferation and neuronal progenitor cells but decreased GABAergic neurons, and this neurogenic activity was independent of its typical receptor tek.DiscussionOur results prove that angpt1 and itgb1b, besides regulating vascular development, act as a neurogenic factor via notch and wnt signaling pathways in the neural proliferation zone in the developing brain, indicating a novel role of dual regulation of angpt1 in embryonic neurogenesis that supports the concept of angiopoietin-based therapeutics in neurological disorders

    Novel Approaches to Improve Myeloma Cell Killing by Monoclonal Antibodies

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    The monoclonal antibodies (mAbs) have significantly changed the treatment of multiple myeloma (MM) patients. However, despite their introduction, MM remains an incurable disease. The mAbs currently used for MM treatment were developed with different mechanisms of action able to target antigens, such as cluster of differentiation 38 (CD38) and SLAM family member 7 (SLAMF7) expressed by both, MM cells and the immune microenvironment cells. In this review, we focused on the mechanisms of action of the main mAbs approved for the therapy of MM, and on the possible novel approaches to improve MM cell killing by mAbs. Actually, the combination of anti-CD38 or anti-SLAMF7 mAbs with the immunomodulatory drugs significantly improved the clinical effect in MM patients. On the other hand, pre-clinical evidence indicates that different approaches may increase the efficacy of mAbs. The use of trans-retinoic acid, the cyclophosphamide or the combination of anti-CD47 and anti-CD137 mAbs have given the rationale to design these types of combinations therapies in MM patients in the future. In conclusion, a better understanding of the mechanism of action of the mAbs will allow us to develop novel therapeutic approaches to improve their response rate and to overcome their resistance in MM patients

    Bovine pestivirus is a new alternative virus for multiple myeloma oncolytic virotherapy

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    The oncolytic viruses have shown promising results for the treatment of multiple myeloma. However, the use of human viruses is limited by the patients' antiviral immune response. In this study, we investigated an alternative oncolytic strategy using non-human pathogen viruses as the bovine viral diarrhea virus (BVDV) that were able to interact with CD46

    Stem cell architecture drives myelodysplastic syndrome progression and predicts response to venetoclax-based therapy

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    Myelodysplastic syndromes (MDS) are heterogeneous neoplastic disorders of hematopoietic stem cells (HSCs). The current standard of care for patients with MDS is hypomethylating agent (HMA)-based therapy; however, almost 50% of MDS patients fail HMA therapy and progress to acute myeloid leukemia, facing a dismal prognosis due to lack of approved second-line treatment options. As cancer stem cells are the seeds of disease progression, we investigated the biological properties of the MDS HSCs that drive disease evolution, seeking to uncover vulnerabilities that could be therapeutically exploited. Through integrative molecular profiling of HSCs and progenitor cells in large patient cohorts, we found that MDS HSCs in two distinct differentiation states are maintained throughout the clinical course of the disease, and expand at progression, depending on recurrent activation of the anti-apoptotic regulator BCL-2 or nuclear factor-kappa B-mediated survival pathways. Pharmacologically inhibiting these pathways depleted MDS HSCs and reduced tumor burden in experimental systems. Further, patients with MDS who progressed after failure to frontline HMA therapy and whose HSCs upregulated BCL-2 achieved improved clinical responses to venetoclax-based therapy in the clinical setting. Overall, our study uncovers that HSC architectures in MDS are potential predictive biomarkers to guide second-line treatments after HMA failure. These findings warrant further investigation of HSC-specific survival pathways to identify new therapeutic targets of clinical potential in MDS

    Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

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    A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

    Role of Galectins in Multiple Myeloma

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    Galectins are a family of lectins that bind β-galactose-containing glycoconjugates and are characterized by carbohydrate-recognition domains (CRDs). Galectins exploit several biological functions, including angiogenesis, regulation of immune cell activities and cell adhesion, in both physiological and pathological processes, as tumor progression. Multiple myeloma (MM) is a plasma cell (PC) malignancy characterized by the tight adhesion between tumoral PCs and bone marrow (BM) microenvironment, leading to the increase of PC survival and drug resistance, MM-induced neo-angiogenesis, immunosuppression and osteolytic bone lesions. In this review, we explore the expression profiles and the roles of galectin-1, galectin-3, galectin-8 and galectin-9 in the pathophysiology of MM. We focus on the role of these lectins in the interplay between MM and BM microenvironment cells showing their involvement in MM progression mainly through the regulation of PC survival and MM-induced angiogenesis and osteoclastogenesis. The translational impact of these pre-clinical pieces of evidence is supported by recent data that indicate galectins could be new attractive targets to block MM cell growth in vivo and by the evidence that the expression levels of LGALS1 and LGALS8, genes encoding for galectin-1 and galectin-8 respectively, correlate to MM patients’ survival

    Oncolytic Virotherapy and Microenvironment in Multiple Myeloma

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    Multiple myeloma (MM) is a hematologic malignancy characterized by the accumulation of bone marrow (BM) clonal plasma cells, which are strictly dependent on the microenvironment. Despite the improvement of MM survival with the use of new drugs, MM patients still relapse and become always refractory to the treatment. The development of new therapeutic strategies targeting both tumor and microenvironment cells are necessary. Oncolytic virotherapy represent a promising approach in cancer treatment due to tumor-specific oncolysis and activation of the immune system. Different types of human viruses were checked in preclinical MM models, and the use of several viruses are currently investigated in clinical trials in MM patients. More recently, the use of alternative non-human viruses has been also highlighted in preclinical studies. This strategy could avoid the antiviral immune response of the patients against human viruses due to vaccination or natural infections, which could invalid the efficiency of virotherapy approach. In this review, we explored the effects of the main oncolytic viruses, which act through both direct and indirect mechanisms targeting myeloma and microenvironment cells inducing an anti-MM response. The efficacy of the oncolytic virus-therapy in combination with other anti-MM drugs targeting the microenvironment has been also discussed

    PD-L1/PD-1 Axis in Multiple Myeloma Microenvironment and a Possible Link with CD38-Mediated Immune-Suppression

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    The emerging role of the PD-1/PD-L1 axis in MM immune-microenvironment has been highlighted by several studies. However, discordant data have been reported on PD-1/PD-L1 distribution within the bone marrow (BM) microenvironment of patients with monoclonal gammopathies. In addition, the efficacy of PD-1/PD-L1 blockade as a therapeutic strategy to reverse myeloma immune suppression and inhibit myeloma cell survival still remains unknown. Recent data suggest that, among the potential mechanisms behind the lack of responsiveness or resistance to anti-PD-L1/PD-1 antibodies, the CD38 metabolic pathways involving the immune-suppressive factor, adenosine, could play an important role. This review summarizes the available data on PD-1/PD-L1 expression in patients with MM, reporting the main mechanisms of regulation of PD-1/PD-L1 axis. The possible link between the CD38 and PD-1/PD-L1 pathways is also reported, highlighting the rationale for the potential use of a combined therapeutic approach with CD38 blocking agents and anti-PD-1/PD-L1 antibodies in order to improve their anti-tumoral effect in MM patients
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