RESUMO
The environment, containing pollutants, toxins, and transition metals (copper, iron, manganese, and zinc), plays a critical role in neurodegenerative disease development. Copper occupational exposure increases Parkinson's disease (PD) risk. Previously, we determined the mechanisms by which copper induces dopaminergic cell death in vitro. The copper transporter protein 1 (Ctr1) overexpression led to intracellular glutathione depletion potentiating caspase-3 mediated cell death; oxidative stress was primarily cytosolic, and Nrf2 was upregulated mediating an antioxidant response; and protein ubiquitination, AMPK-Ulk1 signaling, p62, and Atg5-dependent autophagy were increased as a protective mechanism. However, the effect of chronic copper exposure on the neurodegenerative process has not been explored in vivo. We aimed to elucidate whether prolonged copper treatment reproduces PD features and mechanisms during aging. Throughout 40 weeks, C57BL/6J male mice were treated with copper at 0, 100, 250, and 500 ppm in the drinking water. Chronic copper exposure altered motor function and induced dopaminergic neuronal loss, astrocytosis, and microgliosis in a dose-dependent manner. α-Synuclein accumulation and aggregation were increased in response to copper, and the proteasome and autophagy alterations, previously observed in vitro, were confirmed in vivo, where protein ubiquitination, AMPK phosphorylation, and the autophagy marker LC3-II were also increased by copper exposure. Finally, nitrosative stress was induced by copper in a concentration-dependent fashion, as evidenced by increased protein nitration. To our knowledge, this is the first study combining chronic copper exposure and aging, which may represent an in vivo model of non-genetic PD and help to assess potential prophylactic and therapeutic approaches. DATA AVAILABILITY: The data underlying this article are available in the article.
Assuntos
Doenças Neurodegenerativas , Doença de Parkinson , Camundongos , Animais , Masculino , Cobre/toxicidade , Cobre/metabolismo , Doenças Neurodegenerativas/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Camundongos Endogâmicos C57BL , alfa-Sinucleína/metabolismo , Doença de Parkinson/metabolismo , Neurônios Dopaminérgicos , EnvelhecimentoRESUMO
Biometals are all metal ions that are essential for all living organisms. About 40% of all enzymes with known structures require biometals to function correctly. The main target of damage by biometals is the central nervous system (CNS). Biometal dysregulation (metal deficiency or overload) is related to pathological processes. Chronic occupational and environmental exposure to biometals, including iron and copper, is related to an increased risk of developing Parkinson's disease (PD). Indeed, biometals have been shown to induce a dopaminergic neuronal loss in the substantia nigra. Although the etiology of PD is still unknown, oxidative stress dysregulation, mitochondrial dysfunction, and inhibition of both the ubiquitin-proteasome system (UPS) and autophagy are related to dopaminergic neuronal death. Herein, we addressed the involvement of redox-active biometals, iron, and copper, as oxidative stress and neuronal death inducers, as well as the current metal chelation-based therapy in PD.
Assuntos
Doença de Parkinson , Oligoelementos , Humanos , Doença de Parkinson/patologia , Cobre , Metais , Ferro , Estresse Oxidativo , Oxirredução , Neurônios Dopaminérgicos/patologia , Quelantes/farmacologia , Quelantes/uso terapêuticoRESUMO
OBJECTIVE: To generate an immunogenic chimeric protein containing the Entamoeba histolytica LC3 fragment fused to the retrograde delivery domains of exotoxin A of Pseudomonas aeruginosa and KDEL3 for use as an effective vaccine. RESULTS: A codon-optimized synthetic gene encoding the PEΔIII-LC3-KDEL3 fusion construct was designed for expression in Pichia pastoris. This transgene was subcloned into the plasmid pPIC9 for methanol-inducible expression. After transformation and selection of positive-transformed clones by PCR, the expression of the recombinant protein PEΔIII-LC3-KDEL3 was elicited. SDS-PAGE, protein glycosylation staining and western blot assays demonstrated a 67 kDa protein in the medium culture supernatant. The recombinant protein was detected with a polyclonal anti-6X His tag antibody and a polyclonal E. histolytica-specific antibody. A specific antibody response was induced in hamsters after immunization with this protein. CONCLUSIONS: We report for the first time the design and expression of the recombinant E. histolytica LC3 protein fused to PEΔIII and KDEL3, with potential application as an immunogen.
Assuntos
ADP Ribose Transferases/genética , Toxinas Bacterianas/genética , Entamoeba histolytica/genética , Exotoxinas/genética , Proteínas Recombinantes de Fusão/genética , Vacinas , Fatores de Virulência/genética , ADP Ribose Transferases/imunologia , Animais , Toxinas Bacterianas/imunologia , Entamoeba histolytica/imunologia , Exotoxinas/imunologia , Pichia/genética , Proteínas Recombinantes de Fusão/imunologia , Fatores de Virulência/imunologia , Exotoxina A de Pseudomonas aeruginosaRESUMO
Chemokines are members of the super family of cytokines necessary for leukocyte recruitment in tissues and lymphoid organs. The interferon-gamma inducible protein-10 (IP-10) chemo-attracts CXCR3-expressing cells, such as activated T lymphocytes and monocytes. We have genetically engineered a strain of Lactococcus lactis to secrete a biologically active murine IP-10 that interacts with human CXCR3, its homolog receptor, and chemo-attracts human CD3+ T lymphocytes.
Assuntos
Complexo CD3/metabolismo , Fatores Quimiotáticos/farmacologia , Lactococcus lactis/metabolismo , Linfócitos/efeitos dos fármacos , Receptores de Citocinas/metabolismo , Sequência de Aminoácidos , Animais , Quimiotaxia/efeitos dos fármacos , Humanos , Linfócitos/citologia , Camundongos , Dados de Sequência Molecular , Receptores de Citocinas/química , Alinhamento de SequênciaRESUMO
Lymphotactin-XCL1 is a chemokine produced mainly by activated CD8+ T-cells and directs migration of CD4+ and CD8+ lymphocytes and natural killer (NK) cells. We expressed human lymphotactin (LTN) by the lactic-acid bacterium Lactococcus lactis. Biological activity of LTN was confirmed by chemo-attraction of human T-cells by chemotaxis demonstrating, for the first time, how this chemokine secreted by a food-grade prokaryote retains biological activity and chemoattracts T lymphocytes. This strain thus represents a feasible well-tolerated vector to deliver active LTN at a mucosal level.