15 research outputs found

    Atm reactivation reverses ataxia telangiectasia phenotypes in vivo

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    Hereditary deficiencies in DNA damage signaling are invariably associated with cancer predisposition, immunodeficiency, radiation sensitivity, gonadal abnormalities, premature aging, and tissue degeneration. ATM kinase has been established as a central player in DNA double-strand break repair and its deficiency causes ataxia telangiectasia, a rare, multi-system disease with no cure. So ATM represents a highly attractive target for the development of novel types of gene therapy or transplantation strategies. Atm tamoxifen-inducible mouse models were generated to explore whether Atm reconstitution is able to restore Atm function in an Atm-deficient background. Body weight, immunodeficiency, spermatogenesis, and radioresistance were recovered in transgenic mice within 1 month from Atm induction. Notably, life span was doubled after Atm restoration, mice were protected from thymoma and no cerebellar defects were observed. Atm signaling was functional after DNA damage in vivo and in vitro. In summary, we propose a new Atm mouse model to investigate novel therapeutic strategies for ATM activation in ataxia telangiectasia disease

    Modulation of the cardiomyocyte contractile function inside a hydrostatic pressure bioreactor: verification of the Frank-Starling law

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    We have studied beating mouse cardiac syncytia in vitro in order to assess the inotropic, ergotropic, and chronotropic effects of both increasing and decreasing hydrostatic pressures. In particular, we have performed an image processing analysis to evaluate the kinematics and the dynamics of those pressure-loaded beating syncytia starting from the video registration of their contraction movement. By this analysis, we have verified the Frank-Starling law of the heart in in vitro beating cardiac syncytia and we have obtained their geometrical-functional classificatio

    Modulation of the cardiomyocyte contraction inside a hydrostatic pressure bioreactor: in vitro verification of the Frank-Starling law

    No full text
    We have studied beating mouse cardiac syncytia in vitro in order to assess the inotropic, ergotropic, and chronotropic effects of both increasing and decreasing hydrostatic pressures. In particular, we have performed an image processing analysis to evaluate the kinematics and the dynamics of that pressure-loaded beating syncytia starting from the video registration of their contraction movement. By this analysis, we have verified the Frank-Starling law of the heart in in vitro beating cardiac syncytia and we have obtained their geometrical-functional classification

    Modulation of the cardiomyocyte contraction inside a hydrostatic pressure bioreactor: in vitro verification of the Frank-Starling law

    No full text
    We have studied beating mouse cardiac syncytia in vitro in order to assess the inotropic, ergotropic, and chronotropic effects of both increasing and decreasing hydrostatic pressures. In particular, we have performed an image processing analysis to evaluate the kinematics and the dynamics of that pressure-loaded beating syncytia starting from the video registration of their contraction movement. By this analysis, we have verified the Frank-Starling law of the heart in in vitro beating cardiac syncytia and we have obtained their geometrical-functional classification

    The role of semaphorin signaling in the etiology of hypogonadotropic hypogonadism

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    In mammals fertility depends on timely onset and cyclic secretion of gonadotropin-releasing hormone (GnRH), secreted by scattered hypothalamic neurons (GnRH neurons). These cells originate in the nasal placode and migrate first in the nasal compartment, then through the cribriform plate and finally across the basal forebrain, before they set in their final position in the hypothalamus. This long journey is regulated by many different factors that could be mutated in neuroendocrine syndromes such as congenital hypogonadotropic hypogonadism (CHH), Kallmann Syndrome (KS) and CHARGE syndrome. Recently, semaphorins, a large family of molecules, previously discovered as axon guidance cues, are emerging as key regulators of the neuroendocrine control of GnRH neurons and are acquiring an increasing role in the etiopathogenesis of CHH and KS. Specifically, semaphorins play a multifaceted action in GnRH neuron biology: on one hand regulating their migration and survival during embryonic development and, on the other, controlling the plasticity of the median eminence (ME) in terms of its response to varying sex steroid hormone levels. In this review we will focus our attention on recent studies describing the roles of different semaphorins in the normal and pathological biology of the GnRH neuronal system

    Comparative metabolic profiling by 1H-NMR spectroscopy analysis reveals the adaptation of S. mansoni from its host to in vitro culture conditions: a pilot study with ex vivo and GSH-supplemented medium-cultured parasites

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    Schistosomiasis is a neglected tropical disease caused by parasitic flatworms (blood fluke) of the genus Schistosoma. Parasites acquire most nutrients for their development and sustainment within the definitive host either by ingestion into the gut or across the body surface. Over the years, the best conditions for long-term maintenance of parasites in vitro have been thoroughly established. In our hands, H-1-NMR spectroscopy represents a powerful tool to characterize the metabolic changes in S. mansoni in response to culturing condition perturbations. In order to compare the metabolic fingerprint of ex vivo and parasites cultured in vitro with or without the supplement of reduced glutathione, we conducted a pilot study applying the H-1-NMR spectroscopy-based metabolomics. We obtained new insight into specific metabolic pathways modulated under these different experimental conditions

    (+)-(R)- and (−)-(S)-Perhexiline maleate: Enantioselective synthesis and functional studies on Schistosoma mansoni larval and adult stages

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    Schistosomiasis is a neglected tropical disease mainly affecting the poorest tropical and subtropical areas of the world with the impressive number of roughly 200 million infections per year. Schistosomes are blood trematode flukes of the genus Schistosoma causing symptoms in humans and animals. Organ morbidity is caused by the accumulation of parasite eggs and subsequent development of fibrosis. If left untreated, schistosomiasis can result in substantial morbidity and even mortality. Praziquantel (PZQ) is the most effective and widely used compound for the treatment of the disease, in prevention and control programs in the last 30 years. Unfortunately, it has no effect on juvenile immature schistosomes and cannot prevent reinfection or interfere with the schistosome life cycle; moreover drug-resistance represents a serious threat. The search for an alternative or complementary treatment is urgent and drug repurposing could accelerate a solution. The anti-anginal drug perhexiline maleate (PHX) has been previously shown to be effective on larval, juvenile, and adult stages of S. mansoni and to impact egg production in vitro. Since PHX is a racemic mixture of R-(+)- and S-(−)-enantiomers, we designed and realized a stereoselective synthesis of both PHX enantiomers and developed an analytical procedure for the direct quantification of the enantiomeric excess also suitable for semipreparative separation of PHX enantiomers. We next investigated the impact of each enantiomer on viability of newly transformed schistosomula (NTS) and worm pairs of S. mansoni as well as on egg production and vitellarium morphology by in vitro studies. Our results indicate that the R-(+)-PHX is mainly driving the anti-schistosomal activity but that also the S-(−)-PHX possesses a significant activity towards S. mansoni in vitro

    Atm reactivation reverses ataxia telangiectasia phenotypes in vivo

    No full text
    Hereditary deficiencies in DNA damage signaling are invariably associated with cancer predisposition, immunodeficiency, radiation sensitivity, gonadal abnormalities, premature aging, and tissue degeneration. ATM kinase has been established as a central player in DNA double-strand break repair and its deficiency causes ataxia telangiectasia, a rare, multi-system disease with no cure. So ATM represents a highly attractive target for the development of novel types of gene therapy or transplantation strategies. Atm tamoxifen-inducible mouse models were generated to explore whether Atm reconstitution is able to restore Atm function in an Atm-deficient background. Body weight, immunodeficiency, spermatogenesis, and radioresistance were recovered in transgenic mice within 1 month from Atm induction. Notably, life span was doubled after Atm restoration, mice were protected from thymoma and no cerebellar defects were observed. Atm signaling was functional after DNA damage in vivo and in vitro. In summary, we propose a new Atm mouse model to investigate novel therapeutic strategies for ATM activation in ataxia telangiectasia disease

    β-Adrenergic response is counteracted by extremely-low-frequency pulsed electromagnetic fields in beating cardiomyocytes

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    Proper β-adrenergic signaling is indispensable for modulating heart frequency. Studies on extremely-low-frequency pulsed electromagnetic field (ELF-PEMF) effects in the heart beat function are contradictory and no definitive conclusions were obtained so far. To investigate the interplay between ELF-PEMF exposure and β-adrenergic signaling, cultures of primary murine neonatal cardiomyocytes and of sinoatrial node were exposed to ELF-PEMF and short and long-term effects were evaluated. The ELF-PEMF generated a variable magnetic induction field of 0-6mT at a frequency of 75Hz. Exposure to 3mT ELF-PEMF induced a decrease of contraction rate, Ca2+ transients, contraction force, and energy consumption both under basal conditions and after β-adrenergic stimulation in neonatal cardiomyocytes. ELF-PEMF exposure inhibited β-adrenergic response in sinoatrial node (SAN) region. ELF-PEMF specifically modulated β2 adrenergic receptor response and the exposure did not modify the increase of contraction rate after adenylate cyclase stimulation by forskolin. In HEK293T cells transfected with β1 or β2 adrenergic receptors, ELF-PEMF exposure induced a rapid and selective internalization of β2 adrenergic receptor. The β-adrenergic signaling, was reduced trough Gi protein by ELF-PEMF exposure since the phosphorylation level of phospholamban and the PI3K pathway were impaired after isoproterenol stimulation in neonatal cardiomyocytes. Long term effects of ELF-PEMF exposure were assessed in cultures of isolated cardiomyocytes. ELF-PEMF counteracts cell size increase, the generation of binucleated of cardiomyocytes and prevents the up-regulation of hypertrophic markers after β-adrenergic stimulation, indicating an inhibition of cell growth and maturation. These data show that short and long term exposure to ELF-PEMF induces a reduction of cardiac β-adrenergic response at molecular, functional and adaptative levels
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