Histone Acetylation Defects in Brain Precursor Cells: A Potential Pathogenic Mechanism Causing Proliferation and Differentiation Dysfunctions in Mitochondrial Aspartate-Glutamate Carrier Isoform 1 Deficiency

Mitochondrial aspartate-glutamate carrier isoform 1 (AGC1) deficiency is an ultra-rare genetic disease characterized by global hypomyelination and brain atrophy, caused by mutations in the SLC25A12 gene leading to a reduction in AGC1 activity. In both neuronal precursor cells and oligodendrocytes precursor cells (NPCs and OPCs), the AGC1 determines reduced proliferation with an accelerated differentiation of OPCs, both associated with gene expression dysregulation. Epigenetic regulation of gene expression through histone acetylation plays a crucial role in the proliferation/differentiation of both NPCs and OPCs and is modulated by mitochondrial metabolism. In AGC1 deficiency models, both OPCs and NPCs show an altered expression of transcription factors involved in the proliferation/differentiation of brain precursor cells (BPCs) as well as a reduction in histone acetylation with a parallel alteration in the expression and activity of histone acetyltransferases (HATs) and histone deacetylases (HDACs). In this study, histone acetylation dysfunctions have been dissected in in vitro models of AGC1 deficiency OPCs (Oli-Neu cells) and NPCs (neurospheres), in physiological conditions and following pharmacological treatments. The inhibition of HATs by curcumin arrests the proliferation of OPCs leading to their differentiation, while the inhibition of HDACs by suberanilohydroxamic acid (SAHA) has only a limited effect on proliferation, but it significantly stimulates the differentiation of OPCs. In NPCs, both treatments determine an alteration in the commitment toward glial cells. These data contribute to clarifying the molecular and epigenetic mechanisms regulating the proliferation/differentiation of OPCs and NPCs. This will help to identify potential targets for new therapeutic approaches that are able to increase the OPCs pool and to sustain their differentiation toward oligodendrocytes and to myelination/remyelination processes in AGC1 deficiency, as well as in other white matter neuropathologies

Deficiency of mitochondrial aspartate-glutamate carrier 1 leads to oligodendrocyte precursor cell proliferation defects both in vitro and in vivo

Aspartate-Glutamate Carrier 1 (AGC1) deficiency is a rare neurological disease caused by mutations in the solute carrier family 25, member 12 (SLC25A12) gene, encoding for the mitochondrial aspartate-glutamate carrier isoform 1 (AGC1), a component of the malate-aspartate NADH shuttle (MAS), expressed in excitable tissues only. AGC1 deficiency patients are children showing severe hypotonia, arrested psychomotor development, seizures and global hypomyelination. While the effect of AGC1 deficiency in neurons and neuronal function has been deeply studied, little is known about oligodendrocytes and their precursors, the brain cells involved in myelination. Here we studied the effect of AGC1 down-regulation on oligodendrocyte precursor cells (OPCs), using both in vitro and in vivo mouse disease models. In the cell model, we showed that a reduced expression of AGC1 induces a deficit of OPC proliferation leading to their spontaneous and precocious differentiation into oligodendrocytes. Interestingly, this effect seems to be related to a dysregulation in the expression of trophic factors and receptors involved in OPC proliferation/differentiation, such as Platelet-Derived Growth Factor α (PDGFα) and Transforming Growth Factor βs (TGFβs). We also confirmed the OPC reduction in vivo in AGC1-deficent mice, as well as a proliferation deficit in neurospheres from the Subventricular Zone (SVZ) of these animals, thus indicating that AGC1 reduction could affect the proliferation of different brain precursor cells. These data clearly show that AGC1 impairment alters myelination not only by acting on N-acetyl-aspartate production in neurons but also on OPC proliferation and suggest new potential therapeutic targets for the treatment of AGC1 deficiency

Deficiency of Mitochondrial Aspartate-Glutamate Carrier 1 Leads to Oligodendrocyte Precursor Cell Proliferation Defects Both In Vitro and In Vivo

Aspartate-Glutamate Carrier 1 (AGC1) deficiency is a rare neurological disease caused by mutations in the solute carrier family 25, member 12 (SLC25A12) gene, encoding for the mitochondrial aspartate-glutamate carrier isoform 1 (AGC1), a component of the malate-aspartate NADH shuttle (MAS), expressed in excitable tissues only. AGC1 deficiency patients are children showing severe hypotonia, arrested psychomotor development, seizures and global hypomyelination. While the effect of AGC1 deficiency in neurons and neuronal function has been deeply studied, little is known about oligodendrocytes and their precursors, the brain cells involved in myelination. Here we studied the effect of AGC1 down-regulation on oligodendrocyte precursor cells (OPCs), using both in vitro and in vivo mouse disease models. In the cell model, we showed that a reduced expression of AGC1 induces a deficit of OPC proliferation leading to their spontaneous and precocious differentiation into oligodendrocytes. Interestingly, this effect seems to be related to a dysregulation in the expression of trophic factors and receptors involved in OPC proliferation/differentiation, such as Platelet-Derived Growth Factor \u3b1 (PDGF\u3b1) and Transforming Growth Factor \u3b2s (TGF\u3b2s). We also confirmed the OPC reduction in vivo in AGC1-deficent mice, as well as a proliferation deficit in neurospheres from the Subventricular Zone (SVZ) of these animals, thus indicating that AGC1 reduction could affect the proliferation of different brain precursor cells. These data clearly show that AGC1 impairment alters myelination not only by acting on N-acetyl-aspartate production in neurons but also on OPC proliferation and suggest new potential therapeutic targets for the treatment of AGC1 deficiency

Riluzole-Rasagiline Hybrids: Toward the Development of Multi-Target-Directed Ligands for Amyotrophic Lateral Sclerosis

Polypharmacology is a new trend in amyotrophic lateral sclerosis (ALS) therapy and an effective way of addressing a multifactorial etiology involving excitotoxicity, mitochondrial dysfunction, oxidative stress, and microglial activation. Inspired by a reported clinical trial, we converted a riluzole (1)-rasagiline (2) combination into single-molecule multi-target-directed ligands. By a ligand-based approach, the highly structurally integrated hybrids 3-8 were designed and synthesized. Through a target- and phenotypic-based screening pipeline, we identified hit compound 6. It showed monoamine oxidase A (MAO-A) inhibitory activity (IC50 = 6.9 mu M) rationalized by in silico studies as well as in vitro brain permeability. By using neuronal and non-neuronal cell models, including ALS-patient-derived cells, we disclosed for 6 a neuroprotective/neuroinflammatory profile similar to that of the parent compounds and their combination. Furthermore, the unexpected MAO inhibitory activity of 1 (IC50 = 8.7 mu M) might add a piece to the puzzle of its anti-ALS molecular profile

Mediciones de gases en la pluma cratérica y en fumarolas hidrotermales del Complejo Copahue - Caviahue

El Complejo Copahue - Caviahue (provincia de Neuquén) aloja un sistema hidrotermal con un interesante potencial geotérmico y, además, a uno de los volcanes más activos de Argentina: el volcán Copahue. Tanto este volcán como las áreas termales periféricas presentan emisiones gaseosas, las cuales permanentemente aportan información acerca de la actividad del volcán y de las condiciones de los fluidos en el acuífero geotermal. Por este motivo, llevar a cabo un seguimiento de las manifestaciones gaseosas consiste en una actividad relevante y con diversas aplicaciones.En febrero del 2020 se llevó a cabo una campaña de medición de gases en el complejo mencionado. El instrumental utilizado consistió en un equipo Multigas desarrollado por el ICES ? CNEA, capaz de tomar mediciones en tiempo real de concentraciones de CO2, SO2 y H2S, así como de condiciones atmosféricas tales como la presión y la temperatura. Este instrumento fue utilizado para tomar mediciones de la composición de: (i) la pluma cratérica del volcán Copahue y (ii) de las fumarolas en dos sitios termales (Villa de Copahue y Las Maquinitas), emitidas desde el acuífero geotermal periférico. Además, en el sitio Villa de Copahue se realizaron mediciones de flujo de CO2 emitido a través del suelo, con un flujómetro comercial West Systems.Las mediciones en la pluma cratérica del volcán Copahue permitieron obtener relaciones CO2/SO2. Esta valiosa relación constituye una señal geoquímica precursora de erupciones volcánicas. Por otro lado, en las dos áreas termales periféricas se obtuvieron relaciones CO2/H2S. Por último, en la Villa de Copahue se realizó un mapa de flujo del CO2 del suelo, se cuantificó la cantidad de este gas liberado a la atmósfera y, utilizando la relación CO2/H2S, se obtuvo una estimación de la cantidad de H2S emitido.Fil: Lamberti, María Clara Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas. Grupo de Estudio y Seguimiento de Volcanes Activos; ArgentinaFil: Núñez, N.. Comisión Nacional de Energía Atómica; ArgentinaFil: Sánchez, H.. Comisión Nacional de Energía Atómica; ArgentinaFil: Llano, Joaquin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas. Grupo de Estudio y Seguimiento de Volcanes Activos; ArgentinaFil: Carbajal, F.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Vesga Ramires, A.. Comisión Nacional de Energía Atómica; ArgentinaFil: Forte, Pablo Brian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas. Grupo de Estudio y Seguimiento de Volcanes Activos; ArgentinaFil: Massenzio, Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas. Grupo de Estudio y Seguimiento de Volcanes Activos; ArgentinaFil: García, S.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Agusto, Mariano Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas. Grupo de Estudio y Seguimiento de Volcanes Activos; ArgentinaFil: Gómez, M.. Comisión Nacional de Energía Atómica; Argentina15° Encuentro del Centro Internacional de Ciencias de la TierraMendozaArgentinaUniversidad Nacional de CuyoComisión Nacional de Energía Atómic

Bio-organic self-assembled DNA nanostructures and their use in the mitigation of the activation of microglia in neuroinflammation

Neuroinflammation, which is characterized by the activation of microglial cells, is a hallmark of ALS and most other neurodegenerative diseases. In the early phases of chronic neurodegenerative diseases, microglia assume an M2 phenotype, which is neuroprotective, while in advanced phases, they activate to an M1 phenotype which is neurotoxic. The mechanism by which activation spreads among microglial cells is not fully understood yet, but it is known that the exchange of proteins and microRNA is involved and exosomes are play a role in this process1. Studies have shown that activation of microglia stimulates the release of exosomes, altering their composition and function. As some miRNAs are upregulated in neuroinflammation, these could turn up to be transported in higher number and participate to the spreading of neuroinflammation to otherwise resting microglia. After demonstrating that microglia can naturally take up tetrahedron-shaped DNA nanostructures2 even without the need for any transfection agent, we designed and realized several types of modular DNA-based self-assembled nanostructures that can bear functional elements and labelling moieties (such as fluorophores). We engineered these self-assembled nanostructures by incorporating functional components that target and cleave specific miRNAs involved in the activation of microglia (like miR-34a). We observed the uptake of nanostructures by the cells and a reduction of the activation, by quantitating its molecular markers. Mir-34a, otherwise upregulated in activated microglia, was reduced after nanostructure treatment. The self-assembled tetrahedral DNA nanostructures proved a valuable shuttle for delivering specific functional elements to live mammalian cells without being intrinsically toxic. A variety of different organic or biological functional units can be loaded on them for future extensions of their application and the preparation of candidate drugs or theranostics by design. References: [1] F. Massenzio, , E. Peña-Altamira, S. Petralla, M. Virgili, G. Zuccheri, A. Miti, E. Polazzi, I. Mengoni , D. Piffaretti, B. Monti, Biochim Biophys Acta Mol Basis Dis. 2018, 1864, 3771-3785. [2] C. Bergamini, P. Angelini, K. J. Rhoden, A. M. Porcelli, R., G. Zuccheri, Methods, 2014, 67, 185-9

In vivo morphological alterations of TAMs during KCa3.1 inhibition—by using in vivo two-photon time-lapse technology

Tumor associated macrophages (TAMs) are the mostprevalent cells recruited in the tumor microenvironment (TME). Once recruited, TAMs acquire a pro-tumor phenotype characterized by a typical morphology: ameboid in the tumor core and with larger soma and thick branches in the tumor periphery. Targeting TAMs by reverting them to an anti-tumor phenotype is a promising strategy for cancer immunotherapy. Taking advantage of Cx3cr1GFP/WT heterozygous mice implanted with murine glioma GL261-RFP cells we investigated the role of Ca2+-activated K+ channel (KCa3.1) on the phenotypic shift of TAMs at the late stage of glioma growth through in vivo two-photon imaging. We demonstrated that TAMs respond promptly to KCa3.1 inhibition using a selective inhibitor of the channel (TRAM-34) in a time-dependent manner by boosting ramified projections attributable to a less hypertrophic phenotype in the tumor core. We also revealed a selective effect of drug treatment by reducing both glioma cells and TAMs in the tumor core with no interference with surrounding cells. Taken together, our data indicate a TRAM-34-dependent progressive morphological transformation of TAMs toward a ramified and anti-tumor phenotype, suggesting that the timing of KCa3.1 inhibition is a key point to allow beneficial effects on TAMs

Changing paradigm to target microglia in neurodegenerative diseases: from anti-inflammatory strategy to active immunomodulation.

INTRODUCTION: The importance of microglia in most neurodegenerative pathologies, from Parkinson's disease to amyotrophic lateral sclerosis and Alzheimer's disease, is increasingly recognized. Until few years ago, microglial activation in pathological conditions was considered dangerous to neurons due to its causing inflammation. Today we know that these glial cells also play a crucial physiological and neuroprotective role, which is altered in neurodegenerative conditions. AREAS COVERED: The neuroinflammatory hypothesis for neurodegenerative diseases has led to the trial of anti-inflammatory agents as therapeutics with largely disappointing results. New information about the physiopathological role of microglia has highlighted the importance of immunomodulation as a potential new therapeutic approach. This review summarizes knowledge on microglia as a potential therapeutic target in the most common neurodegenerative diseases, with focus on compounds directed toward the modulation of microglial immune response through specific molecular pathways. EXPERT OPINION: Here we support the innovative concept of targeting microglial cells by modulating their activity, rather than simply trying to counteract their inflammatory neurotoxicity, as a potential therapeutic approach for neurodegenerative diseases. The advantage of this therapeutic approach could be to reduce neuroinflammation and toxicity, while at the same time strengthening intrinsic neuroprotective properties of microglia and promoting neuroregeneration

Preliminary evidence for high anti-PLAC1 antibody levels in infertile patients with repeated unexplained implantation failure

Objective: Placenta-specific1 (PLAC1) is a trophoblast-specific gene encoding for a protein that is highly expressed in human placenta, on the surface of the syncytiotrophoblast. PLAC1 was found to elicit spontaneous antibody responses in cancer patients. We aimed to determine the levels of anti-PLAC1 antibodies in infertile women with a history of unexplained repeated implantation failure after IVF cycles as compared to fertile women. Study design: An observational case-control clinical study. Main outcome measure(s): Two groups of patients were analysed in two different experimental settings: 21 infertile women and 81 control patients were enrolled in the first group, 16 infertile women and 67 fertile controls in the second group. Anti-PLAC1 antibody levels and ranking were analysed by ELISA test. Results: In both groups of infertile patients enrolled, optical densities (OD) from ELEA test ranked significantly higher than those of controls (0.27 +/- 0.2 vs. 0.13 +/- 0.1 respectively; p = 0.0009 in the first group), (0.62 +/- 0.38 vs. 0.39 +/- 0.35 respectively; p = 0.0044 in the second experiment). In the first group about one case in four (29%) had OD levels above the 95thpercentile (0.337) for healthy controls (p = 0.005). In the second experiment 4 out of 16 cases (25%) had OD levels above the 95th percentile (0.878) for healthy controls (p = 0.023). Conclusions: Anti-PLAC1 antibodies could represent a biomarker associated with infertility and with high probability of repeated implantation failure after ovarian stimulation and IVF-ET, greatly improving the diagnostic work up of infertile couples. (C) 2013 Elsevier Ltd. All rights reserved