4-Hydroxynonenal Inhibition of Insulin Secretion via Single Vesicle

Imaging

Voiceover

Presenter(s)

Vrishank Bikkumalla

Abstract or Description

4-Hydroxynonenal or 4-HNE is a reactive lipid aldehyde formed from oxidative stress, a byproduct of inflammation. As a reactive lipid aldehyde, 4-HNE is known to disrupt cellular processes by reacting with a modifying proteins. Inflammation is also a key marker for a variety of different chronic diseases, including type II diabetes, a disease where pancreatic beta cells do not produce enough insulin to keep up with the body's demands. Despite this, the effects of surface level modification in pancreatic beta cells by 4-HNE are not well understood. In order to this, however, the effect of 4-HNE on insulin secretion must first be documented. As such, there are two main goals of this study: 1) to use cell culture and microscopy techniques to determine if insulin secretion is inhibited by 4-HNE and 2) the magnitude of this effect. GRINCH cells, a rat insulinoma cell line, stably expressing a Green Fluorescent Protein (GFP) vesicle tag, were cultured two weeks prior. Total Internal Fluorescence Microcopy was used to image the cells before and after 4-HNE treatment and vehicle treatment of ethanol. Cells were then stimulated with potassium chloride to induce secretion. The number of secretion events were then counted per each cell. Graphical analysis showed a clear trend was witnessed that 4-HNE was inhibiting insulin secretion compared to vehicle treatment. Further analysis is needed to classify the number of events as percentage of total vesicles on each cell. The study sets a foundation to further study surface level proteins called synapotgamins, proteins involved in exocytosis.