PhD Scientific Days 2024

Poster Session F - Molecular Medicine 3.

The influence of insulin in an in-vitro cell culture model of neurodegeneration

Text of the abstract

Introduction
Alzheimer's Disease (AD) is a chronic neurodegenerative condition and the most common cause of dementia. In 2023, around 55 million people worldwide are living with dementia, with AD accounting for 60-70% of these cases (WHO data). Currently, no drug therapy can slow or stop the chronic degeneration of brain nerve cells in AD.
Aim
Our aim is to develop a cell culture model for rapid in vitro testing to examine the effects of cytoprotective compounds. Our research focuses on studying the impairment of insulin signaling, as its role in neuron damage is scientifically accepted. Repositioning compounds that enhance insulin sensitivity, already known in clinical practice, may allow the clinical translation of our basic research data.
Methods
Our research is based on the SH-SY5Y human neuroblastoma cell culture. We differentiated these cells for 5 days using 20 µM retinoic acid in a medium containing 5% FBS. The differentiation was monitored using the Neurite Cell Outgrowth Kit. Bisphenol A (BpA) was used to study the impairment of insulin signaling. We established a dose-response curve for BpA to determine the effective concentration. For insulin, a dose-response curve was also established in the 0.1-30000 pM range to identify concentrations that significantly increase viability. We then assessed cell viability in the presence of BpA across this range. Cell viability was measured using the resazurin viability test.
Results
During the differentiation of SH-SY5Y cells, retinoic acid inhibited cell growth and proliferation, while the number of neurites increased compared to the control group, indicating differentiation from the neuroblastoma phenotype towards neuron-like cells. The dose-response curve for BpA showed dose-dependent cytotoxicity. A concentration of 60 µM was chosen, as it did not cause significant cell death but did significantly reduce viability compared to the control group. While we confirmed the cytoprotective effect of insulin against control damage, insulin could not fully compensate for BpA-induced damage.
Conclusion
Our results suggest that although insulin had a cytoprotective effect against control damage, this effect is diminished in the presence of BpA. Therefore, BpA does not achieve its cytotoxic effect by impairing insulin signaling, indicating that the described model is not suitable for modeling the insulin-resistant state in AD.