Suchergebnisse

Ceria nanoparticles are cell compatible antioxidants whose activity can be enhanced by gold deposition and by surface functionalization with positive triphenylphosphonium units to selectively target the mitochondria. The antioxidant properties of these nanoparticles can serve as the basis of a new strategy for the treatment of several disorders exhibiting oxidative stress, such as cancer, diabetes or Alzheimer's disease. However, all of these pathologies require a specific antioxidant according with their mechanism to remove oxidant species excess in cells and diminish their effect on mitochondrial function. The mechanism through which ceria nanoparticles neutralize oxidative stress and their effect on mitochondrial function have not been characterized yet. In the present study, the mitochondria antioxidant effect of ceria and ceria‐supported gold nanoparticles, with or without triphenylphosphonium functionalization, was assessed in HeLa cells. The effect caused by ceria nanoparticles on mitochondria function in terms of mitochondrial membrane potential (∆Ψm), adenosine triphosphate (ATP) production, nuclear respiratory factor 1 (NRF1) and nuclear factor erythroid–2–like 1 (NFE2L1) was reversed by the presence of gold. Furthermore, this effect was enhanced when nanoparticles were functionalized with triphenylphosphonium. Our study illustrates how the mitochondrial antioxidant effect induced by ceria nanoparticles can be modulated by the presence of gold. ; This research was funded by Carlos III Health Institute and the European Regional Development Fund, grant number CP13/00252 and PI16/1083; the Catalonian Agency for Management of University and Research Grants, grant number 2017SGR1303; the Ministry of Education of the Valencian Regional Government, grant number PROMETEO/2019/027, The Foundation for the Promotion of Health and Biomedical Research of Valencia Region, grant number Nanobetes2.

[EN] Ceria nanoparticles are cell compatible antioxidants whose activity can be enhanced by gold deposition and by surface functionalization with positive triphenylphosphonium units to selectively target the mitochondria. The antioxidant properties of these nanoparticles can serve as the basis of a new strategy for the treatment of several disorders exhibiting oxidative stress, such as cancer, diabetes or Alzheimer's disease. However, all of these pathologies require a specific antioxidant according with their mechanism to remove oxidant species excess in cells and diminish their effect on mitochondrial function. The mechanism through which ceria nanoparticles neutralize oxidative stress and their effect on mitochondrial function have not been characterized yet. In the present study, the mitochondria antioxidant effect of ceria and ceria-supported gold nanoparticles, with or without triphenylphosphonium functionalization, was assessed in HeLa cells. The effect caused by ceria nanoparticles on mitochondria function in terms of mitochondrial membrane potential (Delta Psi m), adenosine triphosphate (ATP) production, nuclear respiratory factor 1 (NRF1) and nuclear factor erythroid-2 like 1 (NFE2L1) was reversed by the presence of gold. Furthermore, this effect was enhanced when nanoparticles were functionalized with triphenylphosphonium. Our study illustrates how the mitochondrial antioxidant effect induced by ceria nanoparticles can be modulated by the presence of gold. ; This research was funded by Carlos III Health Institute and the European Regional Development Fund, grant number CP13/00252 and PI16/1083; the Catalonian Agency for Management of University and Research Grants, grant number 2017SGR1303; the Ministry of Education of the Valencian Regional Government, grant number PROMETEO/2019/027, The Foundation for the Promotion of Health and Biomedical Research of Valencia Region, grant number Nanobetes2. ; Gutiérrez-Carcedo, P.; Navalón Oltra, S.; Simó, R.; Setoain, X.; Aparicio-Gómez, C.; Abasolo, I.; Victor, ...

This work was supported by ERANET-IB08-007 project from the European Union and its linked national project EUI2008- 03610 to AV. We also appreciate the support from EME2007-08 to NFM from Universitat Autonoma de Barcelona, from Antartide 2010 to MLT and EP, from MIUR Azioni Integrate Italia-Spagna 2010 Prot. IT10LECLM9 to MLT, from MINECO (IT2009-0021) to AV and LT, from AGAUR (2009SGR-108) to AV. AV is also supported by The Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN, Spain), an initiative funded by the VI National R&D&i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. PS has received predoctoral fellowship from ISCIII, and AV has been distinguished with an ICREA ACADEMIA award (Catalonia, Spain). ; Obtaining high levels of pure proteins remains the main bottleneck of many scientific and biotechnological studies. Among all the available recombinant expression systems, Escherichia coli facilitates gene expression by its relative simplicity, inexpensive and fast cultivation, well-known genetics and the large number of tools available for its biotechnological application. However, recombinant expression in E. coli is not always a straightforward procedure and major obstacles are encountered when producing many eukaryotic proteins and especially membrane proteins, linked to missing posttranslational modifications, proteolysis and aggregation. In this context, many conventional and unconventional eukaryotic hosts are under exploration and development, but in some cases linked to complex culture media or processes. In this context, alternative bacterial systems able to overcome some of the limitations posed by E. coli keeping the simplicity of prokaryotic manipulation are currently emerging as convenient hosts for protein production. We have comparatively produced a "difficult-to-express" human protein, the lysosomal enzyme alpha-galactosidase A (hGLA) in E. coli and in the psychrophilic bacterium Pseudoalteromonas haloplanktis TAC125 cells (P. haloplanktis TAC125). While in E. coli the production of active hGLA was unreachable due to proteolytic instability and/or protein misfolding, the expression of hGLA gene in P. haloplanktis TAC125 allows obtaining active enzyme. These results are discussed in the context of emerging bacterial systems for protein production that represent appealing alternatives to the regular use of E. coli and also of more complex eukaryotic systems.