Rifampicin quinone pretreatment improves neuronal survival by modulating microglia inflammation induced by α-synuclein

The World Health Organization has predicted that neurodegenerative diseasesaffecting the motor function will become the second most prevalent cause ofdeath in the next 20 years. New therapies can result from three main sources:synthetic compounds, natural products, and existing drugs. Parkinson?s disease (PD) is a common neurodegenerative disease affecting 1?3% of the adult population over 50 years of age worldwide. It is initially characterized by the death of dopaminergic neurons in the substantia nigra pars compact and later by the widespread loss of nondopaminergic neurons, including those in the cortex (Goedert et al., 2013). Inflammation is the main underlying cause in most, if not all, neurodegenerative diseases, playing a protective role in their initial acute phases, but a pernicious one in their later chronic phases. Increasing evidence has disclosed that microglia-mediated neuroinflammation is crucial for PD progression (Hirsch and Hunot, 2009). Another neuropathological hallmark of PD is the presence of Lewy bodies, which are primarily composed of α-synuclein (α-Syn) aggregates (Goedert et al., 2013). In recent years, important studies on the role of α-Syn in PD have been conducted. The α-Syn aggregation in the central nervous system is a pathological process of fundamental importance in the development and progression of PD. Aggregates of α-Syn, in oligomeric and fibril forms, are thought to be capable of causing neurodegeneration either by directly damaging neurons or by activating microglia to produce neuroinflammatory mediators, which are neurotoxic (Hirsch and Hunot, 2009). Due to the consequent neuronal damage, an aggregation and release process of endogenous α-Syn occurs, triggering microglial activation and leading to neuroinflammation (Sanchez-Guajardo et al., 2015). In this way, α-Syn aggregates generate a vicious circle of neuroinflammation and neuronal death in PD. The interaction between these two players, α-Syn aggregates and microglial cells, is thus believed to be strongly implicated in the inflammatory process that accompanies PD progression. However, the molecular mechanisms that underlie α-Syn-induced microglia activation are not well understood.Fil: Acuña, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Corbalan, Natalia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; Argentina. Universidad Nacional de Salta; ArgentinaFil: Raisman Vozari, Rita. Centre de Recherche de I'Institut du Cerveau et de la Moelle Epinière; Francia. Sorbonne University; Francia. Inserm; Franci

Nitric oxide system and basal ganglia physiopathology

Nitric oxide (NO) is a pleiotropic molecule that is needed for physiological functions, especially in the brain NO induces vasodilatation, inhibits apoptosis and plays an important role in memory processes. A population of interneurons has been distinguished in the striatum by nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) staining, an enzyme that is identical with NO synthase (NOS). These interneurons are aspiny cells with dendritic branches and axonal arborisation extending to form a wide field. Single action potentials in these cells produce large inhibitory postsynaptic currents in medium-sized spiny neurons. Release of NO from these neurons facilitates the concurrent release of dopamine and glutamate (GLU). Although the influence of NOS-positive interneurons on striatal neuronal activity remains to be thoroughly characterized, evidence has accumulated suggesting that NO signaling may mediate and/or regulate multiple aspects of striatal neurotransmission. Striatal NO signaling has a major impact on the responsiveness of dopaminergic (DA) neurons to electrical stimulation of the striatum and to some extent, the prefrontal cortex. Moreover, it is likely that NO signalling plays an important role in regulating the activity of striatal output neurons. Thus, striatal NOS interneurons may be critically involved in integrating corticostriatal sensorimotor information within striatal networks and synchronizing the activity of functionally related striatonigral sub-systems. Our studies showed that systemic injections of the inhibitors of NOS decrease either elevate plus maze exploration or rearing in an open field arena. These results may involve motor effects of these compounds, since inhibitors of NOS induced catalepsy in mice. This effect was also found in rats after systemic, intracebroventricular or intrastriatal administration. Chronic NO synthesis inhibition induces plastic changes in NO producing neurons in areas related to motor control. In the same way, the application of NOS inhibitor twice a day, during four days caused cross-tolerance to the cataleptic effect of haloperidol. This raises the possibility that such treatments could decrease motor side effects associated with antipsychotic medications. However, NO can be harmful mainly under oxidative stress conditions due to the oxidation and nitrotyrosilation of functional proteins. Considerable existing evidences indicate a role for NO–DA interactions in pathophysiological conditions such as Parkinson's disease (PD) and schizophrenia. However, the findings on the impact of nitrergic mechanisms in schizophrenia and PD are contradictory. In addition, the slow progression of these diseases, complicates experimental approaches to modeling their pathophysiological mechanism. Inducing experimental Parkinson in rats we found an interaction between NO system and neurodegenerative processes in the nigrostriatal pathway. Because NOS is an enzyme widely distributed and involved in a plethora of necessary physiological responses inside and outside the brain, the role of NO in human neurodegenerative disease is not as easily understood.peer-reviewe

Chemicals Possessing a Neurotrophin-Like Activity on Dopaminergic Neurons in Primary Culture

BACKGROUND:Neurotrophic factors have been shown to possess strong neuroprotective and neurorestaurative properties in Parkinson's disease patients. However the issues to control their delivery into the interest areas of the brain and their surgical administration linked to their unability to cross the blood brain barrier are many drawbacks responsible of undesirable side effects limiting their clinical use. A strategy implying the use of neurotrophic small molecules could provide an interesting alternative avoiding neurotrophin administration and side effects. In an attempt to develop drugs mimicking neurotrophic factors, we have designed and synthesized low molecular weight molecules that exhibit neuroprotective and neuritogenic potential for dopaminergic neurons. PRINCIPAL FINDINGS:A cell-based screening of an in-house quinoline-derived compound collection led to the characterization of compounds exhibiting both activities in the nanomolar range on mesencephalic dopaminergic neurons in spontaneous or 1-methyl-4-phenylpyridinium (MPP(+))-induced neurodegeneration. This study provides evidence that rescued neurons possess a functional dopamine transporter and underlines the involvement of the extracellular signal-regulated kinase 1/2 signaling pathway in these processes. CONCLUSION:Cell-based screening led to the discovery of a potent neurotrophic compound possessing expected physico-chemical properties for blood brain barrier penetration as a serious candidate for therapeutic use in Parkinson disease

Intranasal glyphosate-based herbicide administration alters the redox balance and the cholinergic system in the mouse brain

Pesticide exposure is associated with cognitive and psychomotor disorders. Glyphosate-based herbicides (GlyBH) are among the most used agrochemicals, and inhalation of GlyBH sprays may arise from frequent aerial pulverizations. Previously, we described that intranasal (IN) administration of GlyBH in mice decreases locomotor activity, increases anxiety, and impairs recognition memory. Then, the aim of the present study was to investigate the mechanisms involved in GlyBH neurotoxicity after IN administration. Adult male CF-1 mice were exposed to GlyBH IN administration (equivalent to 50 mg/kg/day of Gly acid, 3 days a week, during 4 weeks). Total thiol content and the activity of the enzymes catalase, acetylcholinesterase and transaminases were evaluated in different brain areas. In addition, markers of the cholinergic and the nigrostriatal pathways, as well as of astrocytes were evaluated by fluorescence microscopy in coronal brain sections. The brain areas chosen for analysis were those seen to be affected in our previous study. GlyBH IN administration impaired the redox balance of the brain and modified the activities of enzymes involved in cholinergic and glutamatergic pathways. Moreover, GlyBH treatment decreased the number of cholinergic neurons in the medial septum as well as the expression of the α7-acetylcholine receptor in the hippocampus. Also, the number of astrocytes increased in the anterior olfactory nucleus of the exposed mice. Taken together, these disturbances may contribute to the neurobehavioural impairments reported previously by us after IN GlyBH administration in mice.Fil: Gallegos, Cristina Eugenia. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Toxicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Bartos, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Toxicología; ArgentinaFil: Gumilar, Fernanda Andrea. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Toxicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Raisman Vozari, Rita. Université Pierre et Marie Curie; Francia. Institut National de la Santé et de la Recherche Médicale; FranciaFil: Minetti, Silvia Alejandra. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Toxicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Baier, Carlos Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Toxicología; Argentin

Exploiting the therapeutic potential of ready-to-use drugs: Repurposing antibiotics against amyloid aggregation in neurodegenerative diseases

Neurodegenerative diseases are chronic and progressive disorders that affect specific regions of the brain, causing gradual disability and suffering that results in a complete inability of patients to perform daily functions. Amyloid aggregation of specific proteins is the most common biological event that is responsible for neuronal death and neurodegeneration in various neurodegenerative diseases. Therapeutic agents capable of interfering with the abnormal aggregation are required, but traditional drug discovery has fallen short. The exploration of new uses for approved drugs provides a useful alternative to fill the gap between the increasing incidence of neurodegenerative diseases and the long-term assessment of classical drug discovery technologies. Drug re-profiling is currently the quickest possible transition from bench to bedside. In this way, experimental evidence shows that some antibiotic compounds exert neuroprotective action through anti-aggregating activity on disease-associated proteins. The finding that many antibiotics can cross the blood-brain barrier and have been used for several decades without serious toxic effects makes them excellent candidates for therapeutic switching towards neurological disorders. The present review is, to our knowledge, the first extensive evaluation and analysis of the anti-amyloidogenic effect of different antibiotics on well-known disease-associated proteins. In addition, we propose a common structural signature derived from the antiaggregant antibiotic molecules that could be relevant to rational drug discovery.Fil: Socias, Sergio Benjamin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; ArgentinaFil: González Lizarraga, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; ArgentinaFil: Avila, Cesar Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; ArgentinaFil: Vera Ocampo, Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; ArgentinaFil: Acuña, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; Argentina. Centre National de la Recherche Scientifique; Francia. Universite de la Sorbona Nouvelle; FranciaFil: Sepúlveda Díaz, Julia E.. Universite de la Sorbona Nouvelle; Francia. Centre National de la Recherche Scientifique; FranciaFil: del Bel Belluz Guimaraes, Elaine. Universidade de Sao Paulo; BrasilFil: Raisman Vozari, Rita. Universite de la Sorbona Nouvelle; Francia. Centre National de la Recherche Scientifique; FranciaFil: Chehin, Rosana Nieves. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Biológica; Argentin

CMT-3 targets different α-synuclein aggregates mitigating their toxic and inflammogenic effects

Parkinson's disease (PD) is a neurodegenerative disorder for which only symptomatic treatments are available. Repurposing drugs that target α-synuclein aggregation, considered one of the main drivers of PD progression, could accelerate the development of disease-modifying therapies. In this work, we focused on chemically modified tetracycline 3 (CMT-3), a derivative with reduced antibiotic activity that crosses the blood–brain barrier and is pharmacologically safe. We found that CMT-3 inhibited α-synuclein amyloid aggregation and led to the formation of non-toxic molecular species, unlike minocycline. Furthermore, CMT-3 disassembled preformed α-synuclein amyloid fibrils into smaller fragments that were unable to seed in subsequent aggregation reactions. Most interestingly, disaggregated species were non-toxic and less inflammogenic on brain microglial cells. Finally, we modelled the interactions between CMT-3 and α-synuclein aggregates by molecular simulations. In this way, we propose a mechanism for fibril disassembly. Our results place CMT-3 as a potential disease modifier for PD and possibly other synucleinopathies.Fil: González Lizarraga, Maria Florencia. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Ploper, Diego. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Avila, Cesar Luis. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Socias, Sergio Benjamin. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: dos Santos Pereira, Mauricio. Universidade de Sao Paulo; BrasilFil: Machín, Belén. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; ArgentinaFil: Del Bel, Elaine. Universidade de Sao Paulo; BrasilFil: Michel, Patrick Pierre. Centre National de la Recherche Scientifique; FranciaFil: Pietrasanta, Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Raisman Vozari, Rita. Centre National de la Recherche Scientifique; FranciaFil: Chehin, Rosana Nieves. Universidad Nacional de Tucumán. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucumán. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet Noa Sur. Instituto de Investigaciones en Medicina Molecular y Celular Aplicada del Bicentenario; Argentin

Rifampicin and Its Derivative Rifampicin Quinone Reduce Microglial Inflammatory Responses and Neurodegeneration Induced In Vitro by α-Synuclein Fibrillary Aggregates

Abstract: Aggregated forms of the synaptic protein α‐synuclein (αS) have been proposed to operateas a molecular trigger for microglial inflammatory processes and neurodegeneration in Parkinson´sdisease. Here, we used brain microglial cell cultures activated by fibrillary forms of recombinanthuman αS to assess the anti‐inflammatory and neuroprotective activities of the antibiotic rifampicin(Rif) and its autoxidation product rifampicin quinone (RifQ). Pretreatments with Rif and RifQreduced the secretion of prototypical inflammatory cytokines (TNF‐, IL‐6) and the burst ofoxidative stress in microglial cells activated with αS fibrillary aggregates. Note, however, that RifQwas constantly more efficacious than its parent compound in reducing microglial activation. Wealso established that the suppressive effects of Rif and RifQ on cytokine release was probably dueto inhibition of both PI3K‐ and non‐PI3K‐dependent signaling events. The control of oxidative stressappeared, however, essentially dependent on PI3K inhibition. Of interest, we also showed that RifQwas more efficient than Rif in protecting neuronal cells from toxic factors secreted by microgliaactivated by αS fibrils. Overall, data with RifQ are promising enough to justify further studies toconfirm the potential of this compound as an anti‐parkinsionian drug.Fil: Acuña, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; Argentina. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: Hamadat, Sabah. Sorbonne University; FranciaFil: Corbalan, Natalia Soledad. Université Paris Est Créteil; Francia. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: González Lizarraga, Maria Florencia. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Dos Santos Pereira, Mauricio. Sorbonne University; Francia. Centre National de la Recherche Scientifique; Francia. Universidade de Sao Paulo; BrasilFil: Rocca, Jérémy. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: Sepúlveda Díaz, Julia. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: Del Bel, Elaine. Universidade de Sao Paulo; BrasilFil: Papy García, Dulce. Université Paris Est Créteil; FranciaFil: Chehin, Rosana Nieves. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Michel, Patrick P.. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: Raisman Vozari, Rita. Sorbonne University; Francia. Centre National de la Recherche Scientifique; Franci

HS3ST2 expression is critical for the abnormal phosphorylation of tau in Alzheimer's disease-related tau pathology

Heparan sulphate (glucosamine) 3-O-sulphotransferase 2 (HS3ST2, also known as 3OST2) is an enzyme predominantly expressed in neurons wherein it generates rare 3-O-sulphated domains of unknown functions in heparan sulphates. in Alzheimer's disease, heparan sulphates accumulate at the intracellular level in disease neurons where they co-localize with the neurofibrillary pathology, while they persist at the neuronal cell membrane in normal brain. However, it is unknown whether HS3ST2 and its 3-O-sulphated heparan sulphate products are involved in the mechanisms leading to the abnormal phosphorylation of tau in Alzheimer's disease and related tauopathies. Here, we first measured the transcript levels of all human heparan sulphate sulphotransferases in hippocampus of Alzheimer's disease (n = 8; 76.8 +/- 3.5 years old) and found increased expression of HS3ST2 (P < 0.001) compared with control brain (n = 8; 67.8 +/- 2.9 years old). Then, to investigate whether the membrane-associated 3-O-sulphated heparan sulphates translocate to the intracellular level under pathological conditions, we used two cell models of tauopathy in neuro-differentiated SH-SY5Y cells: a tau mutation-dependent model in cells expressing human tau carrying the P-301L mutation hTau P-301L, and a tau mutation-independent model in where tau hyperphosphorylation is induced by oxidative stress. Confocal microscopy, fluorescence resonance energy transfer, and western blot analyses showed that 3-O-sulphated heparan sulphates can be internalized into cells where they interact with tau, promoting its abnormal phosphorylation, but not that of p38 or NF-kappa B p65. We showed, in vitro, that the 3-O-sulphated heparan sulphates bind to tau, but not to GSK3B, protein kinase A or protein phosphatase 2, inducing its abnormal phosphorylation. Finally, we demonstrated in a zebrafish model of tauopathy expressing the hTau P-301L, that inhibiting hs3st2 (also known as 3ost2) expression results in a strong inhibition of the abnormally phosphorylated tau epitopes in brain and in spinal cord, leading to a complete recovery of motor neuronal axons length (n = 25; P < 0.005) and of the animal motor response to touching stimuli (n = 150; P < 0.005). Our findings indicate that HS3ST2 centrally participates to the molecular mechanisms leading the abnormal phosphorylation of tau. By interacting with tau at the intracellular level, the 3-O-sulphated heparan sulphates produced by HS3ST2 might act as molecular chaperones allowing the abnormal phosphorylation of tau. We propose HS3ST2 as a novel therapeutic target for Alzheimer's disease.Association France Alzheimer & Maladies ApparenteesSATT Idf InnovCONACyT, MexicoFrench Ministry of Higher Education and ResearchInstitute de Recherche ServierUniv Paris Est, CNRS, Lab Cell Growth Tissue Repair & Regenerat CRRET, UPEC,EA 4397,ERL 9215, F-94000 Creteil, FranceUPMC, Univ Paris 04, Inst Cerveau & Moelle Epiniere, CNRS,UMR 7225,INSERM,U1127,UM75, Paris, FranceHop Robert Debre, INSERM, UMR 1141, F-75019 Paris, FranceSorbonne Paris Cite, Univ Paris Diderot, Paris, FranceUniversidade Federal de São Paulo, Aging & Neurodegenerat Dis Brain Bank Invest Lab, BR-04023062 São Paulo, BrazilGrp Hosp Pitie Salpetriere, Biochim Malad Neurometab, F-75013 Paris, FranceRadboud Univ Nijmegen, Med Ctr, Radboud Inst Mol Life Sci, NL-6525 ED Nijmegen, NetherlandsUniv Strasbourg, INSERM, U1119, FMTS, F-67000 Strasbourg, FranceUniversidade Federal de São Paulo, Aging & Neurodegenerat Dis Brain Bank Invest Lab, BR-04023062 São Paulo, BrazilCONACyT, Mexico: 308978Web of Scienc

Doxycycline interferes with tau aggregation and reduces its neuronal toxicity

Tauopathies are neurodegenerative disorders with increasing incidence and still without cure. The extensive time required for development and approval of novel therapeutics highlights the need for testing and repurposing known safe molecules. Since doxycycline impacts α-synuclein aggregation and toxicity, herein we tested its effect on tau. We found that doxycycline reduces amyloid aggregation of the 2N4R and K18 isoforms of tau protein in a dose-dependent manner. Furthermore, in a cell free system doxycycline also prevents tau seeding and in cell culture reduces toxicity of tau aggregates. Overall, our results expand the spectrum of action of doxycycline against aggregation-prone proteins, opening novel perspectives for its repurposing as a disease-modifying drug for tauopathies.Fil: Medina, Luciana. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: González Lizarraga, Maria Florencia. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Dominguez Meijide, Antonio. Universidad de Santiago de Compostela; EspañaFil: Ploper, Diego. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Parrales, Valeria. Sorbonne University; FranciaFil: Sequeira, Sabrina. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Cima Omori, Maria Sol. German Center for Neurodegenerative Diseases Deutsches Zentrum für Neurodegenerative Erkrankungen; AlemaniaFil: Zweckstetter, Markus. Center for Neurodegenerative Diseases Deutsches Zentrum für Neurodegenerative Erkrankungen; AlemaniaFil: del Bel Belluz Guimaraes, Elaine. Universidade de Sao Paulo; BrasilFil: Michel, Patrick Pierre. Sorbonne University; FranciaFil: Outeiro, Tiago Fleming. University of Newcastle; Reino UnidoFil: Raisman Vozari, Rita. Sorbonne University; FranciaFil: Chehin, Rosana Nieves. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Socias, Sergio Benjamin. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; Argentin

EFFETS D'UNE DEPOLARISATION CHRONIQUE SUR LE DEVELOPPEMENT ET LA SURVIE DES NEURONES DOPAMINERGIQUES DU MESENCEPHALE (MODULATION PAR DES ANTAGONISTES DE LA TRANSMISSION GLUTAMATERGIQUE)

AFIN DE MIEUX COMPRENDRE LES MECANISMES CONDUISANT A LA PERTE DES NEURONES DOPAMINERGIQUES DANS LA MALADIE DE PARKINSON ET DE TENTER D'EN PREVENIR LES EFFETS, NOUS AVONS UTILISE UN MODELE DE DEGENERESCENCE SPONTANEE ET PROGRESSIVE DE CES NEURONES, LA SOURIS MUTANTE WEAVER. CHEZ CET ANIMAL, LA PERTE NEURONALE RESULTERAIT D'UNE DEPOLARISATION CHRONIQUE, CONSEQUENCE DE LA MUTATION PONCTUELLE DU CANAL POTASSIQUE GIRK2, EN ASSOCIATION AVEC DES PHENOMENES EXCITOTOXIQUES. APRES AVOIR CARACTERISE LA TOPOGRAPHIE ET LA CINETIQUE DE DEGENERESCENCE DES NEURONES DOPAMINERGIQUES DANS CE MODELE, NOUS AVONS MIS EN EVIDENCE DEUX TYPES DE MORT CELLULAIRE, L'UN APOPTOTIQUE ET L'AUTRE AUTOPHAGIQUE. DE MANIERE PLUS ORIGINALE, NOUS AVONS MONTRE UNE AUGMENTATION DU NOMBRE D'ASTROCYTES GFAP+ PARALLELEMENT A LA DEGENERESCENCE DES NEURONES DOPAMINERGIQUES DANS LA SNPC DES SOURIS WEAVER. CES ASTROCYTES SONT EGALEMENT RETROUVES DANS LA VTA, OU CES NEURONES NE DEGENERENT PAS. ENSUITE, NOUS AVONS MIME LES EFFETS DE LA MUTATION WEAVER DANS UN MODELE DE CULTURE DE MESENCEPHALE DE RAT DANS LEQUEL LES NEURONES DOPAMINERGIQUES ONT ETE SOUMIS A UNE DEPOLARISATION CHRONIQUE PAR AUGMENTATION DES NIVEAUX DE POTASSIUM EXTRACELLULAIRE. GRACE A CE MODELE, NOUS AVONS MONTRE QUE CETTE DEPOLARISATION EXERCAIT UN EFFET DELETERE, MEDIE PAR LES RECEPTEURS NMDA, QUI POUVAIT ETRE PREVENU PAR INHIBITION DES RECEPTEURS IONOTROPIQUES AU GLUTAMATE PAR DES ANTAGONISTES SPECIFIQUES. DANS CES CONDITIONS, LA DEPOLARISATION CHRONIQUE INDUIT DES EFFETS TROPHIQUES RESULTANTS D'UNE AUGMENTATION MODEREE DE LA CONCENTRATION INTRACELLULAIRE DE CALCIUM. ENFIN, LE TRAITEMENT DES SOURIS WEAVER PAR LE RILUZOLE, UN ANTAGONISTE GLUTAMATERGIQUE ATYPIQUE, INDUIT UN IMPORTANT BOURGEONNEMENT DES TERMINAISONS DOPAMINERGIQUES DANS LE STRIATUM ET UNE AUGMENTATION DE L'EXPRESSION DE LA TH ET DE LA DAT DANS LES NEURONES DOPAMINERGIQUES, CE QUI PEUT TEMOIGNER D'UNE RECUPERATION DE L'ACTIVITE ELECTRIQUE NORMALE. EN CONCLUSION, CE TRAVAIL A PERMIS DE MIEUX COMPRENDRE UN DES MECANISMES POUVANT ETRE IMPLIQUE DANS LES EVENEMENTS EXCITOTOXIQUES CONDUISANT A LA DEGENERESCENCE DES NEURONES DOPAMINERGIQUES. DE PLUS, IL DEVRAIT PERMETTRE DE DEVELOPPER DES STRATEGIES THERAPEUTIQUES POUR LA MALADIE DE PARKINSON, BASEES SUR L'UTILISATION D'ANTAGONISTES DES RECEPTEURS GLUTAMATERGIQUES.ORSAY-PARIS 11-BU Sciences (914712101) / SudocSudocFranceF