Investigation of Phosphodiesterase 1B Gene Expression Levels on Amyloid Formation Induced by Food Sweeteners Glycation Products

In this study, it was aimed to investigate the effects of methylglyoxal, metabolic end product of high-fructose diets, on in vitro beta amyloid formation, secondary messenger molecule cyclic adenosine monophosphate (cAMP), and phosphodiesterase 1 (PDE1), which is responsible for the breakdown of this molecule. Human Glioblastoma U-87 MG (ATCC HTB-14) cell line was used in the study. Cells were produced in a sterile incubator at 37°C, 5% CO2 and 95% air in Eagle’s Minimum Essential Medium (E-MEM) containing 10% of fetal bovine serum (FBS) and penicillin/streptomycin/ amphotericin B mixture. In the study, different concentrations of methylglyoxal (100-400 μM) were added to the cells sown in 24-wells one day in advance. At the end of the period, MTT (Thiazolyl Blue Tetrazolium Bromide) reagent was added to the wells to determine the effective concentration of methylglyoxal. Next, PDE1B, PDE1B1 and Aβ1-40 gene expression levels were investigated by real time PCR method. The cAMP protein level was analyzed by ELISA method. In the viability tests, 200 μM concentration of methylglyoxal decreased the cell viability by 28% compared to the control group. This concentration was used as the active concentration and was used for subsequent studies. Again, methylglyoxal was found to increase intracellular cAMP level by 31%. According to the obtained gene expression data, it was found that methylglyoxal was increased Aβ1-40 gene expression by 3.7-fold, whereas PDE1B and PDE1B1 gene expressions were regulated down by 1.6 and 3.3-fold respectively. It is concluded that the fructose diet will have a significant effect on the pathogenesis of Alzheimer’s disease in affected individuals. However, further investigations are needed, especially in vivo trials, to fully elucidate the subject