Immunization with nanovaccines containing mutated K-Ras peptides and imiquimod aggravates heterotopic pancreatic cancer induced in mice

Purpose: The growing incidence and lethality of pancreatic cancer urges the development of new therapeutic approaches. Anti-tumoral vaccines can potentiate the immune response against the tumor, targeting specific antigens expressed only on tumor cells. In this work, we designed new vaccines for pancreatic cancer, composed by chitosan nanocapsules (CS NCs) containing imiquimod (IMQ) as adjuvant, and targeting the K-Ras mutation G12V. Experimental design: We tested the immunogenicity of our vaccines in mice, carrying different combinations of K-Ras mutated peptides. Then, we analyzed their prophylactic and therapeutic efficacy in mice bearing heterotopic pancreatic cancer. Results: Unexpectedly, although good results were observed at short time points, the different combinations of our CS NCs vaccines seemed to potentiate tumor growth and reduce survival rate. We propose that this effect could be due to an inadequate immune response, partially because of the induction of a regulatory tolerogenic response. Conclusion: Our results call for caution in the use of some NCs containing IMQ in the immunotherapy against pancreatic cancer.Agencia Estatal de Investigación | Ref. BIO2017-84974-RXunta de Galicia | Ref. ED431C 2020/02Xunta de Galicia | Ref. ED431G2019/06Xunta de Galicia | Ref. ED481A-2018/230Xunta de Galicia | Ref. ED481A-2018/29

Characterization of the antiproliferative activity of Sargassum muticum low and high molecular weight polysaccharide fractions

The extract obtained by pressurized hot water extraction from Sargassum muticum, to recover the bioactive compound known as fucoidan, was fractionated using membranes of 100, 50, 30, 10, and 5 kDa, obtaining five retentates and the final permeate. These fractions were characterized for phloroglucinol content, protein content, sulfate content, and trolox equivalent antioxidant capacity (TEAC); apart from oligosaccharides, FTIR and molar mass distribution were also evaluated. Retentates of 100 and 50 kDa showed higher values for phloroglucinol, TEAC, and sulfate content. The rheology of the alginate fraction was also evaluated. Regarding the potential antitumoral activity, all fractions were assessed in MCF-7 cells using a metabolic activity assay based on the reduction of a tetrazolium compound, the most efficient being R100 and R50. Based on the results, these fractions were compared with commercial fucoidans at the same concentrations, and similar results were found. In addition, synergistic cytotoxic effects using two drugs commonly used in breast cancer, cis-Platinum (cis-Pt) and 5-fluorouracil (5-FU), were tested in combination with R100 and R50. Promising results were obtained when the retentate and the drugs were mixed, showing an improvement in the cytotoxicity induced by the chemotherapy.Xunta de Galicia | Ref. ED481D-2022-018Xunta de Galicia | Ref. ED481A-2018/294Agencia Estatal de Investigación | Ref. RYC2018-024454-IXunta de Galicia | Ref. ED431F 2020/01Xunta de Galicia | Ref. ED431C-2020/02Xunta de Galicia | Ref. ED431C-2022/0

Influence of Controlled Cooling in Bimodal Scaffold Fabrication Using Polymers with Different Melting Temperatures

Abstract: The combination of different materials and capabilities to manufacture at several scales open new possibilities in scaffold design for bone regeneration. This work is focused on bimodal scaffolds that combine polylactic acid (PLA) melt extruded strands with polycaprolactone (PCL) electrospun fibers. This type of bimodal scaffold offers better mechanical properties, compared to the use of PCL for the extruded strands, and provides potential a means for controlled drug and/or growthfactordeliverythroughtheelectrospunfibers. Thetechnologiesoffuseddepositionmodeling (FDM) and electrospinning were combined to create 3D bimodal constructs. The system uses a controlled cooling system allowing the combination of polymers with different melting temperatures to generate integrated scaffold architecture. The thermoplastic polymers used in the FDM process enhance the mechanical properties of the bimodal scaffold and control the pore structure. Integrated layers of electrospun microfibers induce an increase of the surface area for cell culture purposes, as well as potential in situ controlled drug and/or growth factor delivery. The proposed bimodal scaffolds (PLA extruded strands and PCL electrospun fibers) show appropriate morphology and better mechanical properties when compared to the use of PCL extruded strands. On average, bimodal scaffolds with overall dimensions of 30×30×2.4 mm3 (strand diameter of 0.5 mm, strand stepover of 2.5 mm, pore size of 2 mm, and layer height of 0.3 mm) showed scaffold stiffness of 23.73 MPa and compression strength of 3.85 MPa. A cytotoxicity assay based human fibroblasts showed viability of the scaffold materials. Keywords: tissue engineering; bone; bimodal scaffolds; fused deposition modeling; electrospinning; hybrid manufacturing proces

Eventos ciclónicos y potencial de precipitación en los cabos, México: efectos urbanos

La península del estado de Baja California Sur en México, es la más afectada por eventos ciclónicos, sin embargo, es el que presenta la precipitación media anual más baja del país. En este sentido, debido a que el municipio de Los Cabos cuenta con un gran número de estaciones pluviométricas, se propone un estudio estadístico de los registros pluviométricos disponibles de los eventos ciclónicos comprendidos entre 1950 y 2013, con el objetivo de estimar la precipitación a través de la correlación de la intensidad (velocidad de vientos) y la distancia al punto del estudio (radio de afectación). Los resultados sugieren, que no existe una relación directa entre la precipitación que genera una tormenta ciclónica, la intensidad de la misma y el radio de afectación, no obstante, se precisa que las máximas precipitaciones anuales in situ están relacionadas con eventos ciclónicos, los cuales han ocasionado importantes efectos adversos en la homeostasia del sistema urbano

Immunization with nanovaccines containing mutated K-Ras peptides and imiquimod aggravates heterotopic pancreatic cancer induced in mice

PurposeThe growing incidence and lethality of pancreatic cancer urges the development of new therapeutic approaches. Anti-tumoral vaccines can potentiate the immune response against the tumor, targeting specific antigens expressed only on tumor cells. In this work, we designed new vaccines for pancreatic cancer, composed by chitosan nanocapsules (CS NCs) containing imiquimod (IMQ) as adjuvant, and targeting the K-Ras mutation G12V.Experimental designWe tested the immunogenicity of our vaccines in mice, carrying different combinations of K-Ras mutated peptides. Then, we analyzed their prophylactic and therapeutic efficacy in mice bearing heterotopic pancreatic cancer.ResultsUnexpectedly, although good results were observed at short time points, the different combinations of our CS NCs vaccines seemed to potentiate tumor growth and reduce survival rate. We propose that this effect could be due to an inadequate immune response, partially because of the induction of a regulatory tolerogenic response.ConclusionOur results call for caution in the use of some NCs containing IMQ in the immunotherapy against pancreatic cancer

High spatial heterogeneity and low connectivity of bacterial communities along a Mediterranean subterranean estuary

Unidad de excelencia María de Maeztu CEX2019-000940-MSubterranean estuaries are biogeochemically active coastal sites resulting from the underground mixing of fresh aquifer groundwater and seawater. In these systems, microbial activity can largely transform the chemical elements that may reach the sea through submarine groundwater discharge (SGD), but little is known about the microorganisms thriving in these land-sea transition zones. We present the first spatially-resolved characterization of the bacterial assemblages along a coastal aquifer in the NW Mediterranean, considering the entire subsurface salinity gradient. Combining bulk heterotrophic activity measurements, flow cytometry, microscopy and 16S rRNA gene sequencing we find large variations in prokaryotic abundances, cell size, activity and diversity at both the horizontal and vertical scales that reflect the pronounced physicochemical gradients. The parts of the transect most influenced by freshwater were characterized by smaller cells and lower prokaryotic abundances and heterotrophic production, but some activity hotspots were found at deep low-oxygen saline groundwater sites enriched in nitrite and ammonium. Diverse, heterogeneous and highly endemic communities dominated by Proteobacteria, Patescibacteria, Desulfobacterota and Bacteroidota were observed throughout the aquifer, pointing to clearly differentiated prokaryotic niches across these transition zones and little microbial connectivity between groundwater and Mediterranean seawater habitats. Finally, experimental manipulations unveiled large increases in community heterotrophic activity driven by fast growth of some rare and site-specific groundwater Proteobacteria. Our results indicate that prokaryotic communities within subterranean estuaries are highly heterogeneous in terms of biomass, activity and diversity, suggesting that their role in transforming nutrients will also vary spatially within these terrestrial-marine transition zones

Galaxy classification: deep learning on the OTELO and COSMOS databases

Context. The accurate classification of hundreds of thousands of galaxies observed in modern deep surveys is imperative if we want to understand the universe and its evolution. Aims. Here, we report the use of machine learning techniques to classify early- and late-type galaxies in the OTELO and COSMOS databases using optical and infrared photometry and available shape parameters: either the Sersic index or the concentration index. Methods. We used three classification methods for the OTELO database: 1) u-r color separation , 2) linear discriminant analysis using u-r and a shape parameter classification, and 3) a deep neural network using the r magnitude, several colors, and a shape parameter. We analyzed the performance of each method by sample bootstrapping and tested the performance of our neural network architecture using COSMOS data. Results. The accuracy achieved by the deep neural network is greater than that of the other classification methods, and it can also operate with missing data. Our neural network architecture is able to classify both OTELO and COSMOS datasets regardless of small differences in the photometric bands used in each catalog. Conclusions. In this study we show that the use of deep neural networks is a robust method to mine the cataloged dataComment: 20 pages, 10 tables, 14 figures, Astronomy and Astrophysics (in press

The polypeptides COX2A and COX2B are essential components of the mitochondrial cytochrome c oxidase of Toxoplasma gondii

AbstractTwo genes encoding cytochrome c oxidase subunits, Cox2a and Cox2b, are present in the nuclear genomes of apicomplexan parasites and show sequence similarity to corresponding genes in chlorophycean algae. We explored the presence of COX2A and COX2B subunits in the cytochrome c oxidase of Toxoplasma gondii. Antibodies were raised against a synthetic peptide containing a 14-residue fragment of the COX2A polypeptide and against a hexa-histidine-tagged recombinant COX2B protein. Two distinct immunochemical stainings localized the COX2A and COX2B proteins in the parasite's mitochondria. A mitochondria-enriched fraction exhibited cyanide-sensitive oxygen uptake in the presence of succinate. T. gondii mitochondria were solubilized and subjected to Blue Native Electrophoresis followed by second dimension electrophoresis. Selected protein spots from the 2D gels were subjected to mass spectrometry analysis and polypeptides of mitochondrial complexes III, IV and V were identified. Subunits COX2A and COX2B were detected immunochemically and found to co-migrate with complex IV; therefore, they are subunits of the parasite's cytochrome c oxidase. The apparent molecular mass of the T. gondii mature COX2A subunit differs from that of the chlorophycean alga Polytomella sp. The data suggest that during its biogenesis, the mitochondrial targeting sequence of the apicomplexan COX2A precursor protein may be processed differently than the one from its algal counterpart

Síntesis de nuevos triazolil-glicoconjugados con un fragmento carbazol

En este trabajo se presenta la síntesis de tres nuevos híbridos carbazol-triazol-carbohidrato los cuales podrían ser de potencial utilidad como inhibidores de la enzima -glucosidasa. Los derivados de 1,2,3-triazoles 1,4-disustituidos fueron preparados mediante una reacción de cicloadición alquino-azida catalizada por cobre (I) (CuAAC) entre glucosilazidas (derivadas de la glucosa y de los diacetónidos de la gluco- y alofuranosa) y el 9-propargil-9H-carbazol. Los triazolil-glicoconjugados con un fragmento carbazol se obtuvieron en buenos rendimientos empleando condiciones de microondas y en cortos tiempos de reacción. Estos productos fueron caracterizados adecuadamente por técnicas espectroscópicas convencionales.In this work, the synthesis of three new carbazole-triazole-carbohydrate hybrids is presented, which could be potentially useful as inhibitors of the enzyme -glucosidase. The 1,4-disubstituted 1,2,3-triazole derivatives were prepared by a copper (I) catalyzed alkyne-azide cycloaddition reaction (CuAAC) between glucosylazides (derived from glucose and from the diacetonides of gluco- and alofuranose) and 9-propargyl-9H-carbazole. Triazolyl-glycoconjugates with a carbazole fragment were obtained in good yields using microwave conditions and in short reaction times. These products were adequately characterized by conventional spectroscopic techniques