Increasing evidence suggests that apolipoprotein D (apoD) can play a major role in mediating neuronal regeneration in the central nervous system (CNS).  To investigate further, the present study was carried out to elucidate potential neuroprotection of apoD and its effects on F₂ -isoprostane (F₂-IsoP) and 24-hydroxycholesterol levels in the hippocampus after kainic acid (KA) treatment.  A significant increase in the number of neurons was observed in the cornu ammonis 1 (CA1) region of the hippocampus in slices treated with 10µg/ml and 20µg/ml of apoD after 3hr KA treatment, compared to those that received KA treatment only.  In addition, lactate dehydrogenase (LDH) assay revealed that hippocampal slices treated with 10µg apoD had decreased LDH activity compared to those that received KA treatment only.  Gas chromatography and mass spectrometry (GC/MS) confirmed that treatment with apoD resulted in reduced levels of isoprostanes and cholesterol oxidation products in the slices. These findings indicate that apoD has bound to arachidonic acid (AA) and cholesterol, thus reducing the formation of their metabolites.  It is concluded that apoD has a protective effect on hippocampal pyramidal neurons subjected to excitotoxic neuronal injury.

Students: Adelina Tan Yi Ping & Patrina Maryann D/O A (Diploma in Biomedical Science )

Supervisor: Associate Professor Wei-Yi Ong, Department of Anatomy; Yong Loo Lin, School of Medicine, National University of Singapore