CHARACTERIZATION OF DIFFERENTIATED HUMAN NEUROBLASTOMA SH-SY5Y CELLS IN CULTURE

Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases affecting an estimated 20 million worldwide. The primary pathology of AD is the progressive loss of basal forebrain cholinergic neurons, which is responsible for the cognitive decline experienced by AD patients. The mechanisms underlying this selective vulnerability have not been fully elucidated. Furthermore, oxidative stress is a key factor behind the pathology of AD leading to this neuronal loss. The current literature suggests that there are limited in-vitro models available to accurately simulate the hallmark symptoms of Alzheimer's disease (AD). The SH-SY5Y cell line has been used extensively to study neuronal stress responses but the undifferentiated cell type has been predominantly used. Undifferentiated SH-SY5Y versus differentiated SH-SY5Y have been shown to have different interaction, expression and localization with AD hallmark, amyloid-b -42. This project sought to use differentiated cholinergic cells from the line SH-SY5Y to further isolate and elucidate, in-vitro, the mechanisms behind the oxidative stress response, a key stressor in the pathology of AD. Building upon previous studies, a protocol to differentiate SH-SY5Y cells with retinoic acid (RA) and neurotrophin (BDNF) to mature neurons of the cholinergic phenotype was optimized and implemented. The results showed successful differentiation into the cholinergic phenotype as evidenced via immunofluorescence imaging of choline acetyl transferase (ChAT) expression and mature neurite morphology. To simulate oxidative stress, we exposed both undifferentiated and differentiated SH-SY5Y cells to hypoxic conditions. Results indicated a stress response to mild hypoxic conditions with higher sensitivity in cholinergic differentiated SH-SY5Y. Understanding these hallmark mechanisms behind oxidative stress is crucial to developing mechanism-based therapeutics for AD.