Hippocampal DHCR24 down regulation in a rat model of streptozotocin-induced cognitive decline

The DHCR24 (24-dehydrocholesterol reductase) gene codes a multifunctional protein which consists of enzymatic, antioxidant, and anti-apoptotic activities. It exists in almost all neurons and protects the neural cells against amyloid β toxicity. Several studies have shown the down regulation of DHCR24 in Alzheimer's disease. We examined the time profile of DHCR24-mRNA alteration in an animal model of streptozotocin (STZ)-induced cognitive impairment. The DHCR24 mRNA levels of hippocampus and cognitive impairment were evaluated at 7, 14, and 21 days after intracerebroventricular (ICV)-STZ/Saline administration. DHCR24 expression was down regulated at 14 and 21 days after ICV-STZ administration. The decrease in expression of DHCR24 preceded the onset of the cognitive impairment. These results suggest the potential relation between DHCR24 expression and cognitive impairment.