Consecuencias neurológicas de la inhibición sostenida de GSK-3 en cerebro adulto

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 11-septiembre-0

Mice Lacking Functional Fas Death Receptors Are Protected from Kainic Acid-Induced Apoptosis in the Hippocampus

© 2014, Springer Science+Business Media New York. The Fas receptor (FasR)/Fas ligand (FasL) system plays a significant role in the process of neuronal loss in neurological disorders. Thus, in the present study, we used a real-time PCR array focused apoptosis (Mouse Apoptosis RT2 PCR Array) to study the role of the Fas pathway in the apoptotic process that occurs in a kainic acid (KA) mice experimental model. In fact, significant changes in the transcriptional activity of a total of 23 genes were found in the hippocampus of wild-type C57BL/6 mice after 12 h of KA treatment compared to untreated mice. Among the up-regulated genes, we found key factors involved in the extrinsic apoptotic pathway, such as tnf, fas and fasL, and also in caspase genes (caspase-4, caspase-8 and caspase-3). To discern the importance of the FasR/FasL pathway, mice lacking the functional Fas death receptor (lpr) were also treated with KA. After 24 h of neurotoxin treatment, lpr mice exhibited a reduced number of apoptotic positive cells, determined by the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) method in different regions of the hippocampus, when compared to wild-type mice. In addition, treatment of lpr mice with KA did not produce significant changes in the transcriptional activity of genes related to apoptosis in the hippocampus, either in the fas and fas ligand genes or in caspase-4 and caspase-8 and the executioner caspase-3 genes, as occurred in wild-type C57BL/6 mice. Thus, these data provide direct evidence that Fas signalling plays a key role in the induction of apoptosis in the hippocampus following KA treatment, making the inhibition of the death receptor pathway a potentially suitable target for excitotoxicity neuroprotection in neurological conditions such as epilepsy.Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CiberNed-Instituto de Salud Carlos III) and by grants fromMinisterio de Ciencia (MICINN, MINECO) SAF2009-08233 and SAF2012-34177 and Fundación Ramón Areces to JJL. Grant 2009/SGR00853 from the Generalitat de Catalunya (Autonomous Government of Catalonia) and grants BFU2010-19119/BFI to CA, SAF2011-23631 to AC, and SAF2012-39852-C02-01 to MP from the Spanish Ministerio de Ciencia (MICINN, MINECO) also supported the study. Grant 0177594 from CONACYT (Mexico)Peer Reviewe

GSK-3 Mouse Models to Study Neuronal Apoptosis and Neurodegeneration

Increased GSK-3 activity is believed to contribute to the etiology of chronic disorders like Alzheimer’s disease (AD), schizophrenia, diabetes, and some types of cancer, thus supporting therapeutic potential of GSK-3 inhibitors. Numerous mouse models with modified GSK-3 have been generated in order to study the physiology of GSK-3, its implication in diverse pathologies and the potential effect of GSK-3 inhibitors. In this review we have focused on the relevance of these mouse models for the study of the role of GSK-3 in apoptosis. GSK-3 is involved in two apoptotic pathways, intrinsic and extrinsic pathways, and plays opposite roles depending on the apoptotic signaling process that is activated. It promotes cell death when acting through intrinsic pathway and plays an anti-apoptotic role if the extrinsic pathway is occurring. It is important to dissect this duality since, among the diseases in which GSK-3 is involved, excessive cell death is crucial in some illnesses like neurodegenerative diseases, while a deficient apoptosis is occurring in others such as cancer or autoimmune diseases. The clinical application of a classical GSK-3 inhibitor, lithium, is limited by its toxic consequences, including motor side effects. Recently, the mechanism leading to activation of apoptosis following chronic lithium administration has been described. Understanding this mechanism could help to minimize side effects and to improve application of GSK-3 inhibitors to the treatment of AD and to extend the application to other diseases.Peer reviewedPeer Reviewe

Diverse Large HIV-1 Non-subtype B Clusters Are Spreading Among Men Who Have Sex With Men in Spain

In Western Europe, the HIV-1 epidemic among men who have sex with men (MSM) is dominated by subtype B. However, recently, other genetic forms have been reported to circulate in this population, as evidenced by their grouping in clusters predominantly comprising European individuals. Here we describe four large HIV-1 non-subtype B clusters spreading among MSM in Spain. Samples were collected in 9 regions. A pol fragment was amplified from plasma RNA or blood-extracted DNA. Phylogenetic analyses were performed via maximum likelihood, including database sequences of the same genetic forms as the identified clusters. Times and locations of the most recent common ancestors (MRCA) of clusters were estimated with a Bayesian method. Five large non-subtype B clusters associated with MSM were identified. The largest one, of F1 subtype, was reported previously. The other four were of CRF02_AG (CRF02_1; n = 115) and subtypes A1 (A1_1; n = 66), F1 (F1_3; n = 36), and C (C_7; n = 17). Most individuals belonging to them had been diagnosed of HIV-1 infection in the last 10 years. Each cluster comprised viruses from 3 to 8 Spanish regions and also comprised or was related to viruses from other countries: CRF02_1 comprised a Japanese subcluster and viruses from 8 other countries from Western Europe, Asia, and South America; A1_1 comprised viruses from Portugal, United Kingom, and United States, and was related to the A1 strain circulating in Greece, Albania and Cyprus; F1_3 was related to viruses from Romania; and C_7 comprised viruses from Portugal and was related to a virus from Mozambique. A subcluster within CRF02_1 was associated with heterosexual transmission. Near full-length genomes of each cluster were of uniform genetic form. Times of MRCAs of CRF02_1, A1_1, F1_3, and C_7 were estimated around 1986, 1989, 2013, and 1983, respectively. MRCA locations for CRF02_1 and A1_1 were uncertain (however initial expansions in Spain in Madrid and Vigo, respectively, were estimated) and were most probable in Bilbao, Spain, for F1_3 and Portugal for C_7. These results show that the HIV-1 epidemic among MSM in Spain is becoming increasingly diverse through the expansion of diverse non-subtype B clusters, comprising or related to viruses circulating in other countries

Lysosomal cell death mechanisms in aging

25 p.-4 fig.Lysosomes are degradative organelles essential for cell homeostasis that regulate a variety of processes, from calcium signaling and nutrient responses to autophagic degradation of intracellular components. Lysosomal cell death is mediated by the lethal effects of cathepsins, which are released into the cytoplasm following lysosomal damage. This process of lysosomal membrane permeabilization and cathepsin release is observed in several physiopathological conditions and plays a role in tissue remodeling, the immune response to intracellular pathogens and neurodegenerative diseases. Many evidences indicate that aging strongly influences lysosomal activity by altering the physical and chemical properties of these organelles, rendering them more sensitive to stress. In this review we focus on how aging alters lysosomal function and increases cell sensitivity to lysosomal membrane permeabilization and lysosomal cell death, both in physiological conditions and age-related pathologies.Work in our laboratories is supported by grants from MINECO Consolider CSD2010-00045 to PB and MDL, SAF2012-36079 to PB and SAF2014-57539-R to MDL.Peer reviewe

Chaperone-mediated autophagy and disease: Implications for cancer and neurodegeneration

14 p.-3 fig.-1 tab.Chaperone-mediated autophagy (CMA) is a proteolytic process whereby selected intracellular proteins are degraded inside lysosomes. Owing to its selectivity, CMA participates in the modulation of specific regulatory proteins, thereby playing an important role in multiple cellular processes. Studies conducted over the last two decades have enabled the molecular characterization of this autophagic pathway and the design of specific experimental models, and have underscored the importance of CMA in a range of physiological processes beyond mere protein quality control. Those findings also indicate that decreases in CMA function with increasing age may contribute to the pathogenesis of age-associated diseases, including neurodegeneration and cancer. In the context of neurological diseases, CMA impairment is thought to contribute to the accumulation of misfolded/aggregated proteins, a process central to the pathogenesis of neurodegenerative diseases. CMA therefore constitutes a potential therapeutic target, as its induction accelerates the clearance of pathogenic proteins, promoting cell survival. More recent evidence has highlighted the important and complex role of CMA in cancer biology. While CMA induction may limit tumor development, experimental evidence also indicates that inhibition of this pathway can attenuate the growth of established tumors and improve the response to cancer therapeutics. Here, we describe and discuss the evidence supporting a role of impaired CMA function in neurodegeneration and cancer, as well as future research directions to evaluate the potential of this pathway as a target for the prevention and treatment of these diseases.Work in EA laboratory is supported by the National Institutes of Health: DK124308, P30DK041296 (P&F) and P30AG038072 (P&F). RGS is recipient of the Spanish Ministry of Science and Innovation grant RTI2018-098990-J-I00.Peer reviewe

O CURSO FUNDAMENTAL DA REFORMA FRANCISCO CAMPOS: UM OLHAR SOB AS INSTRUÇÕES PEDAGÓGICAS DO PROGRAMA DE MATEMÁTICA DE 1931

O presente trabalho tem por fim apresentar o programa de Matemática do CursoFundamental e suas Instruções Pedagógicas durante ação da Reforma Francisco Camposno ano de 1931. Tratando-se do estudo de uma disciplina escolar, a investigação foi frutode uma pesquisa desenvolvida no Núcleo de Pós-Graduação em Educação, daUniversidade Federal de Sergipe e obteve auxílio financeiro da Fundação de Apoio àPesquisa e à Inovação Tecnológica do Estado de Sergipe (FAPITEC/SE). Como resultado,verificou-se que o programa de Matemática implementado pela Reforma FranciscoCampos, na aplicação dos seus conteúdos, interagia entre seus ramos, de forma paulatinaaté a 5ª série, atingindo um conjunto. Quanto às instruções pedagógicas, as mesmas foramdescritas de forma geral e sem exemplos práticos sobre a fusão das Matemáticas, contudose apresentavam diferentes daquelas que foram inseridas nos programas do Colégio PedroII, nos anos de 1929 e 1930

Mice with a naturally occurring DISC1 mutation display a broad spectrum of behaviors associated to psychiatric disorders

Disrupted in schizophrenia-1 (DISC1) gene is associated with several neuropsychiatric disorders as it is disrupted by a balanced translocation involving chromosomes 1 and 11 in a large Scottish pedigree with high prevalence of schizophrenia, bipolar disorder and major depression. Since its identification, several mouse models with DISC1 genetic modifications have been generated using different approaches. Interestingly, a natural deletion of 25bp in the 129 mouse strain alters the DISC1 gene reading frame leading to a premature stop codon very close to the gene breakpoint in the mutant allele of the Scottish family. In the present study we confirmed that the 129DISC1Del mutation results in reduced level of full length DISC1 in hippocampus of heterozygous mice and we have characterized the behavioral consequences of heterozygous 129DISC1Del mutation in a mixed B6129 genetic background. We found alterations in spontaneous locomotor activity (hyperactivity in males and hypoactivity in females), deficits in pre-pulse inhibition (PPI) and also increased despair behavior in heterozygous 129DISC1Del mice, thus reproducing typical behaviors associated to psychiatric disorders. Since this mouse strain is widely and commercially available, we propose it as an amenable tool to study DISC1-related biochemical alterations and psychiatric behaviors. © 2014 Gómez-Sintes, Kvajo, Gogos and Lucas.Thiswork was supported by Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas(CiberNed-Instituto de Salud CarlosIII)and by grants from Ministerio de Ciencia(MEC,MICINN)SAF2009-08233 and SAF2012-34177 and Fundación Ramón ArecesPeer Reviewe

Neuronal apoptosis and reversible motor deficit in dominant-negative GSK-3 conditional transgenic mice

Increased glycogen synthase kinase-3 (GSK-3) activity is believed to contribute to the etiology of chronic disorders like Alzheimer's disease and diabetes, thus supporting therapeutic potential of GSK-3 inhibitors. However, sustained GSK-3 inhibition might induce tumorigenesis through β-catenin-APC dysregulation. Besides, sustained in vivo inhibition by genetic means (constitutive knock-out mice) revealed unexpected embryonic lethality due to massive hepatocyte apoptosis. Here, we have generated transgenic mice with conditional (tetracycline system) expression of dominant-negative-GSK-3 as an alternative genetic approach to predict the outcome of chronic GSK-3 inhibition, either per se, or in combination with mouse models of disease. By choosing a postnatal neuron-specific promoter, here we specifically address the neurological consequences. Tet/DN-GSK-3 mice showed increased neuronal apoptosis and impaired motor coordination. Interestingly, DN-GSK-3 expression shut-down restored normal GSK-3 activity and re-established normal incidence of apoptosis and motor coordination. These results reveal the importance of intact GSK-3 activity for adult neuron viability and physiology and warn of potential neurological toxicity of GSK-3 pharmacological inhibition beyond physiological levels. Interestingly, the reversibility data also suggest that unwanted side effects are likely to revert if excessive GSK-3 inhibition is halted.This work was supported by Spanish Ministry of Science and Education (Grants: SAF 2004-05525 to FA, SAF2006-02424 to JA, and SAF 2003-04144 and SAF 2006-05995 to JJL), Comunidad de Madrid, Fundación ‘La Caixa’, Fundación Ramón Areces and Fondo de Investigaciones Sanitarias/isciii-CiberNed. Analía Bortolozzi is recipient of a Ramón y Cajal contract from MEC through IDIBAPS.Peer reviewe