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Publicaciones del Departamento de Histología y Embriología
Astrocytic Expression of the Immunoreceptor CD300f Protects Hippocampal Neurons from Amyloid-β Oligomer Toxicity In Vitro
Curr Alzheimer Res 2017 14(7):778-783
Thiago Zaqueu Lima 1 , Luis Roberto Sardinha 2 , Joan Sayos 3 , Luiz Eugenio Mello 1 , Hugo Peluffo 4
1 Department of Physiology, Universidade Federal de Sao Paulo, Sao Paulo. Brazil. 2 Hospital Israelita Albert Einstein, Sao Paulo. Brazil. 3 Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBBER-BBN), Instituto de Salud Carlos III, Barcelona. Spain. 4 Departamento de Histología y Embriología, Facultad de Medicina, UDELAR, Montevideo, Uruguay; Neuroinflammation and Gene Therapy Laboratory, Institut Pasteur de Montevideo. Uruguay.
DOI: 10.2174/1567205014666170202121709
PMID: 28155597
Pubmed: https://pubmed.ncbi.nlm.nih.gov/28155597
Texto completo: https://www.eurekaselect.com/article/81448
Abstract:
Background: Astrocytes contribute to neuroinflammation that accompanies neurodegenerative disorders such as Alzheimer's disease (AD). In this sense, the toxicity of these diseases might be attenuated through the modulation of astrocytic inflammatory responses. Recently, the CD300f immunoreceptor was described as a new member of the CD300 immunoreceptor family, showing promising modulatory properties.
Objective: Here, we investigated whether overexpression of hCD300f (the human isoform of CD300f) in astrocytes protects hippocampal neurons against the degeneration induced by amyloid-beta (Aβ) oligomer.
Method: Astrocyte monolayers were transfected with hCD300f before seeding the hippocampal neurons, and then the co-culture was exposed to Aβ1-42 oligomers (5 μM, 48h).
Results: hCD300f expression significantly abrogated the neuronal loss elicited by Aβ. This effect was dependent on neuron-astrocyte cell-cell interactions since no protection was observed using conditioned media from transfected astrocytes. Astrocyte modulation was dependent on the cytoplasmic signaling tail of hCD300f. Furthermore hCD300f expression did not affect the ability of astrocytes to uptake Aβ1- 42 oligomers by endocytosis, which discards the possibility that increased Aβ1-42 clearance could mediate neuroprotection by hCD300f.
Conclusion: These results suggest that the astrocyte-directed expression of the hCD300f immune receptor can be a neuroprotective strategy in AD disease.
Post-hatching brain morphogenesis and cell proliferation in the pulse-type mormyrid Mormyrus rume proboscirostris
J Physiol Paris 2016 110(3 Pt B):245-258
Milka Radmilovich 1 , Isabel Barreiro 2 , Leticia Iribarne 3 , Kirsty Grant 4 , Frank Kirschbaum 5 , María E Castelló 6
1 Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; Unidad Asociada "Histología de Sistemas Sensoriales", Facultad de Medicina-Instituto de Investigaciones Biológicas Clemente Estable, Uruguay. Electronic address: milka@fmed.edu.uy. 2 Unidad Asociada "Histología de Sistemas Sensoriales", Facultad de Medicina-Instituto de Investigaciones Biológicas Clemente Estable, Uruguay; Desarrollo y Evolución Neural, Departamento de Neurociencias Integrativas y Computacionales, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, Montevideo, Uruguay. Electronic address: isabelpepis@gmail.com. 3 Desarrollo y Evolución Neural, Departamento de Neurociencias Integrativas y Computacionales, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, Montevideo, Uruguay. Electronic address: irilet@gmail.com. 4 Unit of Neuroscience Information and Complexity, CNRS FRE, 3693 Gif-sur-Yvette, France. Electronic address: kirsty.grant.unic@gmail.com. 5 Unit Biology and Ecology of Fishes, Faculty of Life Sciences, Humboldt University of Berlin, Berlin, Germany. Electronic address: frank.kirschbaum@staff.hu-berlin.de. 6 Unidad Asociada "Histología de Sistemas Sensoriales", Facultad de Medicina-Instituto de Investigaciones Biológicas Clemente Estable, Uruguay; Desarrollo y Evolución Neural, Departamento de Neurociencias Integrativas y Computacionales, Instituto de Investigaciones Biológicas Clemente Estable, Ministerio de Educación y Cultura, Montevideo, Uruguay. Electronic address: mcastello@iibce.edu.uy.
DOI: 10.1016/j.jphysparis.2016.11.007
PMID: 27888101
Pubmed: https://pubmed.ncbi.nlm.nih.gov/27888101
Texto completo: https://linkinghub.elsevier.com/retrieve/pii/S0928-4257(16)30029-8
Abstract:
The anatomical organization of African Mormyrids' brain is a clear example of departure from the average brain morphotype in teleosts, probably related to functional specialization associated to electrosensory processing and sensory-motor coordination. The brain of Mormyrids is characterized by a well-developed rhombencephalic electrosensory lobe interconnected with relatively large mesencephalic torus semicircularis and optic tectum, and a huge and complex cerebellum. This unique morphology might imply cell addition from extraventricular proliferation zones up to late developmental stages. Here we studied the ontogeny of these brain regions in Mormyrus rume proboscirostris from embryonic to adult stages by classical histological techniques and 3D reconstruction, and analyzed the spatial-temporal distribution of proliferating cells, using pulse type BrdU labeling. Brain morphogenesis and maturation progressed in rostral-caudal direction, from 4day old free embryos, through larvae, to juveniles whose brain almost attained adult morphological complexity. The change in the relative size of the telencephalon, and mesencephalic and rhombencephalic brain regions suggest a developmental shift in the relative importance of visual and electrosensory modalities. In free embryos, proliferating cells densely populated the lining of the ventricular system. During development, ventricular proliferating cells decreased in density and extension of distribution, constituting ventricular proliferation zones. The first recognizable one was found at the optic tectum of free embryos. Several extraventricular proliferation zones were found in the cerebellar divisions of larvae, persisting along life. Adult M. rume proboscirostris showed scarce ventricular but profuse cerebellar proliferation zones, particularly at the subpial layer of the valvula cerebelli, similar to lagomorphs. This might indicate that adult cerebellar proliferation is a conserved vertebrate feature.
Ovarian follicular dynamics after aromatizable or non aromatizable neonatal androgenization
J Mol Histol 2016 47(5):491-501
Gabriel Anesetti 1 , Rebeca Chávez-Genaro 2
1 Histology and Embryology Department, School of Medicine, General Flores 2125, CP 11800, Montevideo, Uruguay. ganesett@fmed.edu.uy. 2 Histology and Embryology Department, School of Medicine, General Flores 2125, CP 11800, Montevideo, Uruguay.
DOI: 10.1007/s10735-016-9692-1
PMID: 27541036
Pubmed: https://pubmed.ncbi.nlm.nih.gov/27541036
Texto completo: https://doi.org/10.1007/s10735-016-9692-1
Abstract:
The effects of neonatal testosterone or dihydrotestosterone exposure on ovarian follicular dynamics were analysed at prepubertal, pubertal or adult age in Wistar rats. Both androgens induced a transitory increase on follicular endowment that was partially corrected at puberty. At adult age testosterone prevented ovulation, without significant modifications on follicular dynamics. An increased number of cystic structures were observed from puberty to adult age. However, ovaries of rats treated with dihydrotestosterone showed follicles with evident morphological alterations in granulosa and thecal layers although several corpora lutea were observed. A significant increase in preantral follicles and few cystic structures were detected at advanced adulthood. The size of cyst increased with age. No immunohistochemical changes on growth factors or enzymes related to steroidogenesis in growing follicles were obvious in any group. In both androgenized groups, cysts shared immunohistochemical characteristics exhibited by preovulatory follicles but they were unable to ovulate spontaneously. Our results provide an insight into the role of different androgens in female reproductive system development, indicating a direct effect of dihydrotestosterone on ovarian tissues whereas a central effect would be the main feature of neonatal testosterone exposure. Heterogeneous clinical manifestations seen in pathologies such as polycystic ovary syndrome among women could be associated with subtle hormonal changes during follicular population development.
Ciliary Entry of the Hedgehog Transcriptional Activator Gli2 Is Mediated by the Nuclear Import Machinery but Differs from Nuclear Transport in Being Imp-α/β1-Independent
PLoS One 2016 11(8):e0162033
Belén Torrado 1 , Martín Graña 2 , José L Badano 1 , Florencia Irigoín 1 3
1 Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo CP11400, Uruguay. 2 Bioinformatics Unit, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo CP11400, Uruguay. 3 Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Gral. Flores 2125, Montevideo CP11800, Uruguay.
DOI: 10.1371/journal.pone.0162033
PMID: 27579771
Pubmed: https://pubmed.ncbi.nlm.nih.gov/27579771
Texto completo: https://dx.plos.org/10.1371/journal.pone.0162033
Abstract:
Gli2 is the primary transcriptional activator of Hedgehog signalling in mammals. Upon stimulation of the pathway, Gli2 moves into the cilium before reaching the nucleus. However, the mechanisms underlying its entry into the cilium are not completely understood. Since several similarities have been reported between nuclear and ciliary import, we investigated if the nuclear import machinery participates in Gli2 ciliary entry. Here we show that while two conserved classical nuclear localization signals mediate Gli2 nuclear localization via importin (Imp)-α/β1, these sequences are not required for Gli2 ciliary import. However, blocking Imp-mediated transport through overexpression of GTP-locked Ran reduced the percentage of Gli2 positive cilia, an effect that was not explained by increased CRM1-dependent export of Gli2 from the cilium. We explored the participation of Imp-β2 in Gli2 ciliary traffic and observed that this transporter is involved in moving Gli2 into the cilium, as has been described for other ciliary proteins. In addition, our data indicate that Imp-β2 might also collaborate in Gli2 nuclear entry. How does Imp-β2 determine the final destination of a protein that can localize to two distinct subcellular compartments remains an open question. Therefore, our data shows that the nuclear-cytoplasmic shuttling machinery plays a critical role mediating the subcellular distribution of Gli2 and the activation of the pathway, but distinct importins likely play a differential role mediating its ciliary and nuclear translocation.
A Natural Cattle Immune Response Against Horn Fly (Diptera: Muscidae) Salivary Antigens May Regulate Parasite Blood Intake
J Econ Entomol 2016 109(4):1951-6
M Breijo 1 , L Pastro 2 , S Rocha 3 , X Ures 3 , P Alonzo 3 , M Santos 3 , C Bolatto 4 , C Fernández 5 , A Meikle 6
1 Unidad de Reactivos y Biomodelos de Experimentación, Facultad de Medicina, Universidad de la República, Gral. Flores 2125, Montevideo, Uruguay (mbreijo@fmed.edu.uy; gabrielrocha85@gmail.com; ximenaures@gmail.com; palonzo@higiene.edu.uy; msantos@fmed.edu.uy) mbreijo@fmed.edu.uy. 2 Laboratorio de Interacciones Moleculares, Facultad de Ciencias, Iguá 4225, 11400 Montevideo, Uruguay (lpastro@fcien.edu.uy). 3 Unidad de Reactivos y Biomodelos de Experimentación, Facultad de Medicina, Universidad de la República, Gral. Flores 2125, Montevideo, Uruguay (mbreijo@fmed.edu.uy; gabrielrocha85@gmail.com; ximenaures@gmail.com; palonzo@higiene.edu.uy; msantos@fmed.edu.uy). 4 Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Gral. Flores 2125, Montevideo, Uruguay (cbolatto@fmed.edu.uy). 5 Cátedra de Inmunología, Facultad de Química, Instituto de Higiene, Universidad de la República, Av. Alfredo Navarro 3051, 11600 Montevideo, Uruguay (cfernan@fq.edu.uy). 6 Laboratorio de Técnicas Nucleares, Facultad de Veterinaria, Universidad de la República, Lasplaces 1550, Montevideo, Uruguay (meikleana@gmail.com).
DOI: 10.1093/jee/tow133
PMID: 27329632
Pubmed: https://pubmed.ncbi.nlm.nih.gov/27329632
Texto completo: https://academic.oup.com/jee/article-lookup/doi/10.1093/jee/tow133
Abstract:
The horn fly, Haematobia irritans (L.), is a blood-sucking ectoparasite that is responsible for sizeable economic losses in livestock. The salivary gland products facilitate blood intake. Taking advantage of the identification of novel H. irritans salivary antigens (Hematobin, HTB and Irritans 5, IT5), we investigated the parasite loads, H. irritans blood intake, and antibody response of naturally infected bovines during the fly season. Fly loads and fly hemoglobin content fluctuated during the trial. Each time horn fly loads exceeded 200 flies per cattle, a reduction in horn fly blood intake was observed three weeks later. All of the cattle elicited an antibody response against HTB and IT5 that declined once the fly season was over. Cattle anti-IT5 titers were positively correlated with parasite loads and negatively correlated with fly blood intake. These results suggest that the natural changes in the H. irritans blood intake observed in this study were associated with a natural host response against horn fly salivary antigens.
Post-paralysis tyrosine kinase inhibition with masitinib abrogates neuroinflammation and slows disease progression in inherited amyotrophic lateral sclerosis
J Neuroinflammation 2016 13(1):177
Emiliano Trias 1 , Sofía Ibarburu 1 , Romina Barreto-Núñez 1 , Joël Babdor 2 3 4 5 , Thiago T Maciel 2 3 4 5 6 7 , Matthias Guillo 2 3 4 5 , Laurent Gros 8 , Patrice Dubreuil 7 8 9 , Pablo Díaz-Amarilla 10 , Patricia Cassina 11 , Laura Martínez-Palma 11 , Ivan C Moura 2 3 4 5 6 7 , Joseph S Beckman 12 , Olivier Hermine 13 14 15 16 17 18 19 20 21 , Luis Barbeito 22
1 Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, 11.400, Uruguay. 2 Imagine Institute, Hôpital Necker, 24 boulevard du Montparnasse, 75015, Paris, France. 3 INSERM UMR 1163, Laboratory of Cellular and Molecular Mechanisms of Hematological Disorders and Therapeutic Implications, Paris, France. 4 Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France. 5 CNRS ERL 8254, Paris, France. 6 Laboratory of Excellence GR-Ex, Paris, France. 7 Equipe Labélisée par la Ligue Nationale contre le cancer, Paris, Cedex, France. 8 AB Science, 3 Avenue Georges V, 75008, Paris, France. 9 CRCM, [Signaling, Hematopoiesis and Mechanism of Oncogenesis], Inserm, U1068, Institut Paoli-Calmettes, Aix-Marseille Univ, UM105, CNRS, UMR7258, Marseille, F-13009, France. 10 Laboratorio de Neurobiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay. 11 Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay. 12 Linus Pauling Institute, Department of Biochemistry and Biophysics, Environmental Health Sciences Center, Oregon State University, Corvallis, USA. 13 Imagine Institute, Hôpital Necker, 24 boulevard du Montparnasse, 75015, Paris, France. ohermine@gmail.com. 14 INSERM UMR 1163, Laboratory of Cellular and Molecular Mechanisms of Hematological Disorders and Therapeutic Implications, Paris, France. ohermine@gmail.com. 15 Paris Descartes-Sorbonne Paris Cité University, Imagine Institute, Paris, France. ohermine@gmail.com. 16 CNRS ERL 8254, Paris, France. ohermine@gmail.com. 17 Laboratory of Excellence GR-Ex, Paris, France. ohermine@gmail.com. 18 Equipe Labélisée par la Ligue Nationale contre le cancer, Paris, Cedex, France. ohermine@gmail.com. 19 AB Science, 3 Avenue Georges V, 75008, Paris, France. ohermine@gmail.com. 20 Department of Hematology, Necker Hospital, Paris, France. ohermine@gmail.com. 21 Centre national de référence des mastocytoses (CEREMAST), Paris, France. ohermine@gmail.com. 22 Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, 11.400, Uruguay. barbeito@pateur.edu.uy.
DOI: 10.1186/s12974-016-0620-9
PMID: 27400786
Pubmed: https://pubmed.ncbi.nlm.nih.gov/27400786
Texto completo: https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-016-0620-9
Abstract:
Background: In the SOD1(G93A) mutant rat model of amyotrophic lateral sclerosis (ALS), neuronal death and rapid paralysis progression are associated with the emergence of activated aberrant glial cells that proliferate in the degenerating spinal cord. Whether pharmacological downregulation of such aberrant glial cells will decrease motor neuron death and prolong survival is unknown. We hypothesized that proliferation of aberrant glial cells is dependent on kinase receptor activation, and therefore, the tyrosine kinase inhibitor masitinib (AB1010) could potentially control neuroinflammation in the rat model of ALS.
Methods: The cellular effects of pharmacological inhibition of tyrosine kinases with masitinib were analyzed in cell cultures of microglia isolated from aged symptomatic SOD1(G93A) rats. To determine whether masitinib prevented the appearance of aberrant glial cells or modified post-paralysis survival, the drug was orally administered at 30 mg/kg/day starting after paralysis onset.
Results: We found that masitinib selectively inhibited the tyrosine kinase receptor colony-stimulating factor 1R (CSF-1R) at nanomolar concentrations. In microglia cultures from symptomatic SOD1(G93A) spinal cords, masitinib prevented CSF-induced proliferation, cell migration, and the expression of inflammatory mediators. Oral administration of masitinib to SOD1(G93A) rats starting after paralysis onset decreased the number of aberrant glial cells, microgliosis, and motor neuron pathology in the degenerating spinal cord, relative to vehicle-treated rats. Masitinib treatment initiated 7 days after paralysis onset prolonged post-paralysis survival by 40 %.
Conclusions: These data show that masitinib is capable of controlling microgliosis and the emergence/expansion of aberrant glial cells, thus providing a strong biological rationale for its use to control neuroinflammation in ALS. Remarkably, masitinib significantly prolonged survival when delivered after paralysis onset, an unprecedented effect in preclinical models of ALS, and therefore appears well-suited for treating ALS.
Interactions between environmental factors and maternal-fetal genetic variations: strategies to elucidate risks of preterm birth
Eur J Obstet Gynecol Reprod Biol 2016 202:20-5
Silvana Pereyra 1 , Bernardo Bertoni 2 , Rossana Sapiro 3
1 Departamento de Genética, Facultad de Medicina, Universidad de la República, Av. General Flores 2125, C.P. 11800 Montevideo, Uruguay. Electronic address: spereyra@fmed.edu.uy. 2 Departamento de Genética, Facultad de Medicina, Universidad de la República, Av. General Flores 2125, C.P. 11800 Montevideo, Uruguay. Electronic address: bbertoni@fmed.edu.uy. 3 Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Av. General Flores 2125, C.P. 11800 Montevideo, Uruguay. Electronic address: rsapiro@fmed.edu.uy.
DOI: 10.1016/j.ejogrb.2016.04.030
PMID: 27156152
Pubmed: https://pubmed.ncbi.nlm.nih.gov/27156152
Texto completo: https://linkinghub.elsevier.com/retrieve/pii/S0301-2115(16)30181-6
Abstract:
Context: Preterm birth (PTB) is a complex disease in which medical, social, cultural, and hereditary factors contribute to the pathogenesis of this adverse event. Interactions between genes and environmental factors may complicate our understanding of the relative influence of both effects on PTB. To overcome this, we combined data obtained from a cohort of newborns and their mothers with multiplex analysis of inflammatory-related genes and several environmental risk factors of PTB to describe the environmental-genetic influence on PTB.
Objective: The study aimed to investigate the association between maternal and fetal genetic variations in genes related to the inflammation pathway with PTB and to assess the interaction between environmental factors with these variations.
Study design: We conducted a case-control study at the Pereira Rossell Hospital Center, Montevideo, Uruguay. The study included 143 mother-offspring dyads who delivered at preterm (gestational age<37 weeks) and 108 mother-offspring dyads who delivered at term. We used real-time PCR followed by a high-resolution melting analysis to simultaneously identify gene variations involved in inflammatory pathways in the context of environmental variables. The genes analyzed were: Toll-like receptor 4 (TLR4), Interleukin 6 (IL6), Interleukin 1 beta (IL1B) and Interleukin 12 receptor beta (IL12RB).
Results: We detected a significant interaction between IL1B rs16944 polymorphism in maternal samples and IL6 rs1800795 polymorphism in newborns, emphasizing the role of the interaction of maternal and fetal genomes in PTB. In addition, smoke exposure and premature rupture of membranes (PROM) were significantly different between the premature group and controls. IL1B and IL6 polymorphisms in mothers were significantly associated with PTB when controlling for smoke exposure. TLR4 polymorphism and PROM were significantly associated with PTB when controlling for PROM, but only in the case of severe PTB.
Conclusions: Interactions between maternal and fetal genomes may influence the timing of birth. By incorporating environmental data, we revealed genetic associations with PTB, a finding not found when we analyzed genetic data alone. Our results stress the importance of studying the effect of genotype interactions between mothers and children in the context of environmental factors because they substantially contribute to phenotype variability.
Electrophilic nitro-fatty acids prevent astrocyte-mediated toxicity to motor neurons in a cell model of familial amyotrophic lateral sclerosis via nuclear factor erythroid 2-related factor activation
Free Radic Biol Med 2016 95:112-20
Pablo Diaz-Amarilla 1 * , Ernesto Miquel 2 * , Andrés Trostchansky 3 , Emiliano Trias 4 , Ana M Ferreira 5 , Bruce A Freeman 6 , Patricia Cassina 2 , Luis Barbeito 4 , Marcelo R Vargas 7 , Homero Rubbo 8
1 Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay. 2 Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay. 3 Departamento de Bioquímica and Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay. 4 Institut Pasteur of Montevideo, Montevideo, Uruguay. 5 Catedra de Inmunología, Facultad de Quimica y Ciencias, Universidad de la República, Montevideo, Uruguay. 6 Department of Pharmacology and Chemical Biology, University of Pittsburgh, PA, USA. 7 Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC, USA. 8 Departamento de Bioquímica and Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay. Electronic address: hrubbo@fmed.edu.uy. * These authors contributed equally to this work
DOI: 10.1016/j.freeradbiomed.2016.03.013
PMID: 27012417
Pubmed: https://pubmed.ncbi.nlm.nih.gov/27012417
Texto completo: https://linkinghub.elsevier.com/retrieve/pii/S0891-5849(16)00119-2
Abstract:
Nitro-fatty acids (NO2-FA) are electrophilic signaling mediators formed in tissues during inflammation, which are able to induce pleiotropic cytoprotective and antioxidant pathways including up regulation of Nuclear factor erythroid 2-related factor 2 (Nrf2) responsive genes. Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by the loss of motor neurons associated to an inflammatory process that usually aggravates the disease progression. In ALS animal models, the activation of the transcription factor Nrf2 in astrocytes confers protection to neighboring neurons. It is currently unknown whether NO2-FA can exert protective activity in ALS through Nrf2 activation. Herein we demonstrate that nitro-arachidonic acid (NO2-AA) or nitro-oleic acid (NO2-OA) administrated to astrocytes expressing the ALS-linked hSOD1(G93A) induce antioxidant phase II enzyme expression through Nrf2 activation concomitant with increasing intracellular glutathione levels. Furthermore, treatment of hSOD1(G93A)-expressing astrocytes with NO2-FA prevented their toxicity to motor neurons. Transfection of siRNA targeted to Nrf2 mRNA supported the involvement of Nrf2 activation in NO2-FA-mediated protective effects. Our results show for the first time that NO2-FA induce a potent Nrf2-dependent antioxidant response in astrocytes capable of preventing motor neurons death in a culture model of ALS.
Selenoproteins of African trypanosomes are dispensable for parasite survival in a mammalian host
Mol Biochem Parasitol 2016 206(1-2):13-9
Mariana Bonilla 1 , Erika Krull 1 , Florencia Irigoín 2 , Gustavo Salinas 3 , Marcelo A Comini 4
1 Redox Biology of Trypanosomes Laboratory, Institut Pasteur de Montevideo, Uruguay. 2 Molecular Human Genetics Laboratory, Institut Pasteur de Montevideo, Uruguay; Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay. 3 Worm Biology Laboratory, Institut Pasteur de Montevideo, Uruguay; Cátedra de Inmunología, Departamento de Biociencias, Facultad de Química, Universidad de la República, Montevideo, Uruguay. Electronic address: gsalin@fq.edu.uy. 4 Redox Biology of Trypanosomes Laboratory, Institut Pasteur de Montevideo, Uruguay. Electronic address: mcomini@pasteur.edu.uy.
DOI: 10.1016/j.molbiopara.2016.03.002
PMID: 26975431
Pubmed: https://pubmed.ncbi.nlm.nih.gov/26975431
Texto completo: https://linkinghub.elsevier.com/retrieve/pii/S0166-6851(16)30018-4
Abstract:
The trace element selenium is found in polypeptides as selenocysteine, the 21(st) amino acid that is co-translationally inserted into proteins at a UGA codon. In proteins, selenocysteine usually plays a role as an efficient redox catalyst. Trypanosomatids previously examined harbor a full set of genes encoding the machinery needed for selenocysteine biosynthesis and incorporation into three selenoproteins: SelK, SelT and, the parasite-specific, Seltryp. We investigated the selenoproteome of kinetoplastid species in recently sequenced genomes and assessed the in vivo relevance of selenoproteins for African trypanosomes. Database mining revealed that SelK, SelT and Seltryp genes are present in most kinetoplastids, including the free-living species Bodo saltans, and Seltryp was lost in the subgenus Viannia from the New World Leishmania. Homology and sinteny with bacterial sulfur dioxygenases and sulfur transferases suggest a putative role for Seltryp in sulfur metabolism. A Trypanosoma brucei selenocysteine synthase (SepSecS) null-mutant, in which selenoprotein synthesis is abolished, displayed similar sensitivity to oxidative stress induced by a short-term exposure to high concentrations of methylglyoxal or H2O2 to that of the parental wild-type cell line. Importantly, the infectivity of the SepSecS knockout cell line was not impaired when tested in a mouse infection model and compensatory effects via up-regulation of proteins involved in thiol-redox metabolism were not observed. Collectively, our data show that selenoproteins are not required for survival of African trypanosomes in a mammalian host and exclude a role for selenoproteins in parasite antioxidant defense and/or virulence. On this basis, selenoproteins can be disregarded as drug target candidates.
Increase in the expression of leukocyte elastase inhibitor during wound healing in corneal endothelial cells
Cell Tissue Res 2015 362(3):557-68
Cristian Justet 1 , Frances Evans 1 2 , Alicia Torriglia 3 4 5 , Silvia Chifflet 6
1 Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Gral. Flores 2125, 11800, Montevideo, Uruguay. 2 Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Gral. Flores 2125, 11800, Montevideo, Uruguay. 3 INSERM U1138, Centre de Recherche des Cordeliers, Paris, France. alicia.torriglia@inserm.fr. 4 Université Paris Descartes, Paris, France. alicia.torriglia@inserm.fr. 5 Université Pierre et Marie Curie, Paris, France. alicia.torriglia@inserm.fr. 6 Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Gral. Flores 2125, 11800, Montevideo, Uruguay. schiffle@mednet.org.uy.
DOI: 10.1007/s00441-015-2223-7
PMID: 26085342
Pubmed: https://pubmed.ncbi.nlm.nih.gov/26085342
Texto completo: https://dx.doi.org/10.1007/s00441-015-2223-7
Abstract:
Tissue injury triggers a complex network of cellular and molecular responses. Although cell migration and proliferation are the most conspicuous, several other responses, such as apoptosis and increased protease activity, are necessary for a proper restitution of the tissue. In this work, we study the leukocyte elastase inhibitor (LEI) expression during wound healing of bovine corneal endothelial monolayers in culture. LEI is a multifunctional protein with anti-protease and anti-apoptotic activity. When properly cleaved, it is transformed into L-DNase II, a pro-apoptotic enzyme and translocated to the nucleus. We found that early after injury LEI increases its protein and mRNA expressions, without nuclear translocation and returns to basal levels immediately after wound closure. This increase is blocked by N-acetylcysteine, suggesting that production of reactive oxygen species immediately after wounding is involved in the LEI increase. Another finding of this work is that there is an acidification of the cells at the wound border which, in contrast to other cell types, does not determine nuclear translocation of the protein. Taken together, the results of this work suggest that the function of LEI during wound healing is related to its activity as a protease inhibitor and/or to its anti-apoptotic activity.