Centro de Biología Integrativa (CBI)
https://repositorio.umayor.cl/xmlui/handle/sibum/7696
Contiene la producción documental del CBI2024-03-29T10:56:48ZAssessment of Bio-Compounds Content, Antioxidant Activity, and Neuroprotective Effect of Red Cabbage (Brassica oleracea var. Capitata rubra) Processed by Convective Drying at Different Temperatures
https://repositorio.umayor.cl/xmlui/handle/sibum/9519
Assessment of Bio-Compounds Content, Antioxidant Activity, and Neuroprotective Effect of Red Cabbage (Brassica oleracea var. Capitata rubra) Processed by Convective Drying at Different Temperatures
Vega-Gálvez, Antonio; Gómez-Perez, Luis S.; Zepeda, Francisca; Vidal, Rene L. [Univ Mayor, Fac Ciencias, Ctr Biol Integrat, Chile]; Grunenwald, Felipe [Univ Mayor, Fac Ciencias, Ctr Biol Integrat, Chile]; Mejías, Nicol; Pasten, Alexis; Araya, Michael; Ah-Hen, Kong Shun
Parkinson's disease (PD) is the second most common neurodegenerative disorder, and no efficient therapy able to cure or slow down PD is available. In this study, dehydrated red cabbage was evaluated as a novel source of bio-compounds with neuroprotective capacity. Convective drying was carried out at different temperatures. Total phenolics (TPC), flavonoids (TFC), anthocyanins (TAC), and glucosinolates (TGC) were determined using spectrophotometry, amino acid profile by LC-DAD and fatty acid profile by GC-FID. Phenolic characterization was determined by liquid chromatography-high-resolution mass spectrometry. Cytotoxicity and neuroprotection assays were evaluated in SH-SY5Y human cells, observing the effect on preformed fibrils of alpha-synuclein. Drying kinetic confirmed a shorter processing time with temperature increase. A high concentration of bio-compounds was observed, especially at 90 C-degrees, with TPC = 1544.04 +/- 11.4 mg GAE/100 g, TFC = 690.87 +/- 4.0 mg QE/100 g and TGC = 5244.9 +/- 260.2 mu mol SngE/100 g. TAC degraded with temperature. Glutamic acid and arginine were predominant. Fatty acid profiles were relatively stable and were found to be mostly C18:3n3. The neochlorogenic acid was predominant. The extracts had no cytotoxicity and showed a neuroprotective effect at 24 h testing, which can extend in some cases to 48 h. The present findings underpin the use of red cabbage as a functional food ingredient.
2023-09-01T00:00:00ZSalmonella Type III Secretion Effector SrfJ: A Glucosylceramidase Affecting the Lipidome and the Transcriptome of Mammalian Host Cells
https://repositorio.umayor.cl/xmlui/handle/sibum/9478
Salmonella Type III Secretion Effector SrfJ: A Glucosylceramidase Affecting the Lipidome and the Transcriptome of Mammalian Host Cells
Aguilera-Herce, Julia; Panadero-Medianero, Concepción [Univ Mayor, Fac Sci, Ctr Integrat Biol, Chile]; Sánchez-Romero, María Antonia; Balbontín, Roberto; Bernal-Bayard, Joaquín; Ramos-Morales, Francisco
Type III secretion systems are found in many Gram-negative pathogens and symbionts of animals and plants. Salmonella enterica has two type III secretion systems associated with virulence, one involved in the invasion of host cells and another involved in maintaining an appropriate intracellular niche. SrfJ is an effector of the second type III secretion system. In this study, we explored the biochemical function of SrfJ and the consequences for mammalian host cells of the expression of this S. enterica effector. Our experiments suggest that SrfJ is a glucosylceramidase that alters the lipidome and the transcriptome of host cells, both when expressed alone in epithelial cells and when translocated into macrophages in the context of Salmonella infection. We were able to identify seventeen lipids with higher levels and six lipids with lower levels in the presence of SrfJ. Analysis of the forty-five genes, the expression of which is significantly altered by SrfJ with a fold-change threshold of two, suggests that this effector may be involved in protecting Salmonella from host immune defenses.
2023-05-07T00:00:00ZSenescent Schwann cells induced by aging and chronic denervation impair axonal regeneration following peripheral nerve injury
https://repositorio.umayor.cl/xmlui/handle/sibum/9455
Senescent Schwann cells induced by aging and chronic denervation impair axonal regeneration following peripheral nerve injury
Geronimo-Olvera, Cristian [Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Chile]; Girardi, Karina [Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Chile]; Necuñir-Ibarra, David [Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Chile]; Kumar Patel, Sandip; Bons, Joanna; Wright, Megan C.; Geschwind, Daniel; Hoke, Ahmet; Gómez-Sánchez, José A.; Schilling, Birgit; Rebolledo, Daniela L. [Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Chile]; Campisi, Judith; Court, Felipe A. [Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Chile]
Following peripheral nerve injury, successful axonal growth and functional recovery require Schwann cell (SC) reprogramming into a reparative phenotype, a process dependent upon c-Jun transcription factor activation. Unfortunately, axonal regeneration is greatly impaired in aged organisms and following chronic denervation, which can lead to poor clinical outcomes. While diminished c-Jun expression in SCs has been associated with regenerative failure, it is unclear whether the inability to maintain a repair state is associated with the transition into an axonal growth inhibition phenotype. We here find that reparative SCs transition into a senescent phenotype, characterized by diminished c-Jun expression and secretion of inhibitory factors for axonal regeneration in aging and chronic denervation. In both conditions, the elimination of senescent SCs by systemic senolytic drug treatment or genetic targeting improved nerve regeneration and functional recovery, increased c-Jun expression and decreased nerve inflammation. This work provides the first characterization of senescent SCs and their influence on axonal regeneration in aging and chronic denervation, opening new avenues for enhancing regeneration and functional recovery after peripheral nerve injuries.
2023-12-07T00:00:00ZPoly(ethylene imine)-chitosan carbon dots: study of its physical-chemical properties and biological in vitro performance
https://repositorio.umayor.cl/xmlui/handle/sibum/9454
Poly(ethylene imine)-chitosan carbon dots: study of its physical-chemical properties and biological in vitro performance
Santos, Nicolás [Escuela de Biotecnología, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Chile]; Valenzuela, Santiago; Segura, Camilo; Osorio-Román, Igor; Arrázola, Macarena S. [Centro de Biología Integrativa, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Chile]; Panadero-Medianero, Concepción [Centro de Biología Integrativa, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Chile]; Santana, Paula A.; Ahumada, Manuel [Escuela de Biotecnología, Facultad de Ciencias, Ingeniería y Tecnología, Universidad Mayor, Chile]
Carbon dots (CDs) have been quickly extended for nanomedicine uses because of their multiple applications, such as bioimaging, sensors, and drug delivery. However, the interest in increasing their photoluminescence properties is not always accompanied by cytocompatibility. Thus, a knowledge gap exists regarding their interactions with biological systems linked to the selected formulations and synthesis methods. In this work, we have developed carbon dots (CDs) based on poly (ethylene imine) (PEI) and chitosan (CS) by using microwave irradiation, hydrothermal synthesis, and a combination of both, and further characterized them by physicochemical and biological means. Our results indicate that synthesized CDs have sizes between 1 and 5 nm, a high presence of amine groups on the surface, and increased positive ζ potential values. Further, it is established that the choice and use of different synthesis procedures can contribute to a different answer to the CDs regarding their optical and biological properties. In this regard, PEI-only CDs showed the longest photoluminescent emission lifetime, non-hemolytic activity, and high toxicity against fibroblast. On the other hand, CS-only CDs have higher PL emission, non-cytotoxicity associated with fibroblast, and high hemolytic activity. Interestingly, their combination using the proposed methodologies allow a synergic effect in their CDs properties. Therefore, this work contributes to developing and characterizing CD formulations based on PEI and CS and better understanding the CD's properties and biological interaction.
2023-10-17T00:00:00Z