La cultura política en el pueblo mapuche: el caso Wallmapuwen

En este artículo abordamos la cultura política in­dígena para lo cual se toma el caso concreto del pueblo mapuche. Haciendo un breve recuento de las políticas aplicadas por el Estado chileno, evaluamos los obstáculos que han dificultado la formación del partido político mapuche Wall­mapuwen. Consideramos que la formación de un partido político indígena es una alternativa para reconstituir la identidad cultural y, en un futuro, la autonomía del pueblo mapuche. Al mismo tiempo, para una renovación en su ac­ción colectiva será necesario que sus demandas particulares se articulen estratégicamente con diferentes organizaciones sociales, con y sin adscripción étnica. Afirmamos, además, que los partidos etno-políticos en Latinoamérica avi­zoran fructíferas experiencias de organización para el fortalecimiento de una cultura política democrática.In this article we address indigenous political culture taking as a case of study the Mapuche people. Having carried out a brief overview of the policies applied by the Chilean state, we evaluate those obstacles that have hindered the formation of the Mapuche political party Wallmapuwen. We believe that the formation of a political party by the indigenous people is a means to reconstitute the cultural identity, and in the future, the autonomy of the Mapuche people. At the same time, a revitalization in the collective action will need to have their own particular demands articulated strategically with different social organizations, with and without ethnic affiliation. We affirm, moreover, that ethno-regional parties in Latin America envisage fruitful organizational experiences towards the strengthening of a democratic culture

Electrochromic polyoxometalate material as a sensor of bacterial activity

L. fermentum, a bacterium of human microbiota, acts as an electron donor to the electrochromic [P2MoVI18O62]6. Since, the reductive capacity of L. fermentum correlates with its metabolic activity, the reaction with [P2MoVI18O62]6- affords a means of evaluating its activity. Following this logic, we have concluded that vancomycin severely affects the activity of L. fermentum whereas omeprazole does not.FQM368 Bionanopartículas Metálicas (BioNanomet)Departamento de Química InorgánicaThis work was funded by MINECO and FEDER (project CTQ2012-32236

Identification of the key excreted molecule by Lactobacillus fermentum related to host iron absorption

We have taken a vital step towards understanding why probiotic bacteria increase iron absorption in the gastrointestinal tract. We show here that Lactobacillus fermentum, one of the main probiotics of the microbiota, exhibits an extraordinary ferric-reducing activity. This activity is predominantly due to an excreted molecule: p-hydroxyphenyllactic acid (HPLA). Reduction of Fe(III) to Fe(II) is essential for iron absorption in the gastrointestinal tract. By reducing Fe(III), HPLA boosts Fe(II) absorption through the DMT1 channels of enterocytes. An in vitro experiment tested and confirmed this hypothesis. This discovery opens new avenues for the treatment of iron deficiency in humans, one of the most common and widespread nutritional disorders in the world

Insights on the (Auto)Photocatalysis of Ferritin

Traditionally, ferritin has been considered a photocatalyst capable of photo-oxidizing organic molecules and transferring electrons to external electron acceptors when irradiated by UV–visible light. We have designed new approaches to resolve the uncertainties regarding its photocatalytical mechanism. Experiments with an Fe(II) chelator, an electrochromic indicator, and recombinant ferritin proteins indicate that the excited electrons at the conduction band of the ferritin core do not cross the protein shell. Instead, irradiation causes the electrons to reduce the ferrihydrite core to produce Fe(II) ions. These Fe(II) ions exit the protein shell to reduce electron acceptors. In the absence of electron acceptors or chelators, Fe(II) re-enters ferritin.This work was funded by MINECO and FEDER (CTQ2015-64538). N.S. would like to acknowledge funding from the U.S. Student Fulbright Scholarship

Bacteria-Carried Iron Oxide Nanoparticles for Treatment of Anemia

The efficiency of maghemite nanoparticles for the treatment of anemia was sensibly higher when nanoparticles were incorporated onto the probiotic bacterium Lactobacillus fermentum (MNP-bacteria) than when administrated as uncoated nanoparticles (MNP). Plasma iron and hemoglobin, intestine expression of divalent metal transporter 1 (DMT1) and duodenal Cytochrome b (DcytB), as well as hepatic expression of the hormone hepcidin were fully restored to healthy levels after administration of MNP-bacteria but not of MNP. A magnetic study on biodistribution and biodegradation showed accumulation of maghemite nanoparticles in intestine lumen when MNP-bacteria were administrated. In contrast, MNP barely reached intestine. In vivo MRI studies suggested the internalization of MNP-bacteria into enterocytes, which did not occur with MNP. Transmission electronic microscopy confirmed this internalization. The collective analysis of results point out that L. fermentum is an excellent carrier to overcome the stomach medium and drive maghemite nanoparticles to intestine, where iron absorption occurs. Due the probiotic ability to adhere to the gut wall, MNP-bacteria internalize into the enterocyte, where maghemite nanoparticles are delivered, providing an adequate iron level into enterocyte. This paper advances a new route for effective iron absorption in the treatment of anemia.The efficiency of maghemite nanoparticles for the treatment of anemia was sensibly higher when nanoparticles were incorporated onto the probiotic bacterium Lactobacillus fermentum (MNP-bacteria) than when administrated as uncoated nanoparticles (MNP). Plasma iron and hemoglobin, intestine expression of divalent metal transporter 1 (DMT1) and duodenal Cytochrome b (DcytB), as well as hepatic expression of the hormone hepcidin were fully restored to healthy levels after administration of MNP-bacteria but not of MNP. A magnetic study on biodistribution and biodegradation showed accumulation of maghemite nanoparticles in intestine lumen when MNP-bacteria were administrated. In contrast, MNP barely reached intestine. In vivo MRI studies suggested the internalization of MNP-bacteria into enterocytes, which did not occur with MNP. Transmission electronic microscopy confirmed this internalization. The collective analysis of results point out that L. fermentum is an excellent carrier to overcome the stomach medium and drive maghemite nanoparticles to intestine, where iron absorption occurs. Due the probiotic ability to adhere to the gut wall, MNP-bacteria internalize into the enterocyte, where maghemite nanoparticles are delivered, providing an adequate iron level into enterocyte. This paper advances a new route for effective iron absorption in the treatment of anemia

Artificial Magnetic Bacteria: Living Magnets at Room Temperature

"This is the peer reviewed version of the following article: Martín Marcos, M.A.; et al. Artificial Magnetic Bacteria: Living Magnets at Room Temperature. Advanced Functional Materials, 24(23): 3489-3493 (2014), which has been published in final form at http://dx.doi.org/10.1002/adfm.201303754 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."Biogenic magnetite is a fascinating example of how nature can generate functional magnetic nanostructures. Inspired by the magnetic bacteria, an attempt is made to mimic their magnetic properties, rather than their structures, to create living magnets at room temperature. The non-magnetic probiotic bacteria Lactobacillus fermentum and Bifidobacteria breve are used as bioplatforms to densely arrange superparamagnetic nanoparticles on their external surfaces, thus obtaining the artificial magnetic bacteria. Magnetic probiotic bacteria can be produced by using superparamagnetic maghemite nanoparticles assembled at their surfaces. They present a collective ferromagnetic phase at room temperature. The blocking temperature of these maghemite nanoparticles increases more than 100 K when assembled at the artificial magnetic bacteria.This work was funded by Biosearch S. A. (POSTBIO project-Agency for Innovation and Development of Andalucia IDEA) and by MINECO and FEDER (project CTQ2012–32236)

Selecting FRET pairs for visualizing amyloid aggregation

This work was supported by grant CTQ2017–85658-R funded by MCIN/AEI/10.13039/501100011033/FEDER “Una manera de hacer Europa” and grants PID2019–104366RB-C22 and PID2020–114256RBI00 funded by MCIN/AEI/10.13039/ 501100011033. A.R.-A. thanks the Spanish Ministerio de Educación y Formación Profesional for an FPU Ph.D. studentship.In a recent work, we reported a methodology for imaging the different stages of amyloid aggregation in quantitative multiparametric dual-color fluorescence lifetime imaging (FLIM) and superresolution microscopy by using a pair of dyes capable of binding aggregates and undergoing subsequent intra-aggregate energy transfer (FRET) (RuizArias et al. Sensors Actuat. B, 2022, 350:130882). In this microarticle we present the optimization process for choosing the best pair of dyes through a screening of different naphthalimides and quinolimides and other known amyloid-binding dyes.Spanish Ministerio de Educación y FormaciónGrant CTQ2017–85658-R funded by MCIN/AEI/10.13039/501100011033/FEDER “Una manera de hacer Europa”Grants PID2019–104366RB-C22 and PID2020–114256RBI00 funded by MCIN/AEI/10.13039/ 50110001103