Effect of insulin on IR and GLP1-R expressions in HT22 cells

Insulin is a significant growth factor that specifically binds to the insulin receptor (IR) in the brain and then activates the PI3K-AKT pathway. Glucagon-like peptide 1 (GLP-1) has a variety of functions including neuroprotection, support for neurogenesis, and increasing insulin signal. This study aims to investigate the effect of insulin administered to immortalized clonal mouse hippocampal cell line (HT22) at different doses and intervals on IR, insulin receptor A (IRA), insulin receptor B (IRB), and Glucagon-like peptide 1 receptor (GLP1-R) mRNA expression and protein levels. The cells were planted in 6 well plates at a density of 3 × 10⁵/4 × 10⁵. Cells treated with insulin at different concentrations (5, 10, and 40 nM) were collected at 0.5, 2, 8, 16, and 24 h. RT-PCR and western blot analysis were used to measure mRNA expression and protein levels. Our results showed that insulin has short and long-term effects on IR and GLP1-R expression depending on dose and time. These findings may guide future studies targeting IR isoforms and GLP1-R in particular, as well as determining the optimal dose and duration of insulin stimulation in insulin signaling research.