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Item 2D and 3D Models of Alzheimer’s Disease: Investigating Neuron-like Cells in Oxidative Environments(ACS Publications) Salles, Geisa Rodrigues; Giraldi, Luiza de Andrade; Silva, Newton Soares da; Porcionatto, Marimelia Aparecida; Soares, Cristina PachecoAlzheimer’s disease (AD) is a complex and enigmatic neurodegenerative disorder in which amyloid-β (Aβ) aggregates and oxidative stress play crucial roles in neuronal damage. Aβ forms senile plaques, while reactive oxygen species (ROS)-induced oxidative stress causes cellular dysfunction. Elucidating neuronal injury led by mild and severe oxidative stress may provide insight into how neurons respond to toxic environments. In parallel, modeling AD three-dimensionally is in the spotlight, sustainably contributing to reducing animals in research and replicating spatially neuronal mechanisms, such as neurite network and oxidative stress responses. This study evaluates the effects of oxidative stress on neuron-like cells cultured in two-dimensional (2D) and 3D spheroids, strengthening their potential as platforms for AD investigation. For the 2D models, SH-SY5Y (cells from human neuroblastoma) cells were differentiated into the neuronal phenotype and exposed to mild or severe concentrations of oxygen peroxide (H2O2, 100 or 200 μM, respectively). Cytoviability, ROS, Aβ particle analyses, and morphological aspects were assessed. Neuronal cells under severe stress produced elevated levels of intra- and extracellular Aβ aggregates. A range of Aβ particle analyses were performed comparing their properties, and morphologically, neurites were compromised under severe stress. For the 3D models, SH-SY5Y spheroids were self-assembled by 10 days of cultivation on developed nonadhesive hydrogel microwells and differentiated into the neuronal phenotype; their area, circularity, and solidity were measured. Spheroids were exposed or not to 200 μM H2O2, stained for cytoskeleton/nuclei, and imaged by scanning electron microscopy (SEM), and their viability was evaluated. Throughout the cultivation period, spheroids grew and differentiated morphologically. Neurite distribution was observed along the 3D composition; however, under oxidative stress, cytoviability decreased, abnormal nuclear staining was observed surrounding the spheroids, and morphological disorganization was evident by SEM, representing structural disarrangement and nuclear disruption. Briefly, this study provides a basis for exploring oxidative stress and producing robust 3D approaches to unraveling AD mechanisms.Item Neuroprotective effects of taurine on SH-SY5Y cells under hydrocortisone induced stress(CDRR Editors) Rossato, Rafaella Carvalho; Granato, Alessandro Eustaquio Campos; Moraes, Carlos Dailton Guedes de Oliveira; Salles, Geisa Nogueira; Soares, Cristina PachecoAlzheimer's disease (AD) is the most common, progressive and irreversible neurodegenerative disorder, characterized by memory loss, cognitive impairment and behavioral abnormalities. Although there is no cure, several study strategies seek to elucidate mechanisms of the disease. Recent studies address the benefits of taurine. Thus, the present study aims to analyze neuroprotective effects of taurine in human neuroblastoma (SH-SY5Y), using an in vitro experimental model of oxidative stress induced by hydrocortisone. This work showed for the first time that taurine can promote neuroprotection in SH-SY5Y under oxidative stress caused by hydrocortisone. Cell viability was evaluated using crystal violet and the evaluation of cell morphology was performed by scanning electron microscopy (SEM). The viability of SH-SY5Y pre-treated with taurine and stressed with hydrocortisone was preserved, compared to the stressed only group, which was also morphologically observed. Therefore, taurine can represent a considerable therapeutic candidate in the prevention of neurodegenerative diseases, such as AD.Item Photobiomodulation by LED 660 nm and Taurine against H2O2 oxidative stress in SH-SY5Y cells(Springer Nature Link) Rossato, Rafaella Carvalho; Salles, Geisa Rodrigues; Albuquerque, Amanda Lira; Porcionatto, Marimélia Aparecida; Granato, Alessandro Eustáquio Campos; Ulrich, Henning; Santos, Mariela Inês Batista dos; Soares, Cristina PachecoAlzheimer's Disease (AD) is a progressive uncurable neurodegenerative pathology affecting millions worldwide. Photo- biomodulation and Taurine are promising alternatives for preventing and reducing the rapid progression of neurodegenera- tion, stimulating the reconstructing of neural tissue structures, especially improving mitochondrial activity, which is highly impaired in AD. In this study, the mitochondrial effects of Taurine combined with light emitting diode (LED) irradiation were evaluated on human neuroblastoma cells (SH-SY5Y), under oxidative stress condition by hydrogen peroxide (H2O2) exposure, a considerable modulator in AD. We evaluated LED irradiation at the wavelength of 660 nm and Taurine under different concentrations before and together with exposing SH-SY5Y cells to different concentrations of H2O2, assessing mitochondrial activity by the MTT colorimetric test and labeling live cells mitochondria by the fluorescent probe MitoTracker. Cell viability was also evaluated by the trypan blue exclusion assay, and cellular morphological structures were imaged by scanning electron microscopy (SEM). Neuroprotective effects were achieved by both LED irradiation and LED irradia- tion + Taurine when cells were exposed to them before H2O2-induced stress. Comparing both agents, LED irradiation at 660 nm is sufficient to improve mitochondrial activity, however, healthy mitochondrial morphology was only observed when cells were treated with Taurine together with LED irradiation, representing affordable candidates that act in synergy against oxidative stress, one of the main contributors to neurodegeneration.