engleski

Tissue and age specific changes in CYP51 gene expression in mouse brain

CYP51 gene, a member of a large CYP (cytochrome P450) gene superfamily, found in all biological phyla, encodes lanosterol 14 -demethylase that catalyzes oxidative removal of the 14 -methyl group from lanosterol. In mammals, this enzyme has a pivotal role in postsqualene path of cholesterol biosynthesis that takes place mostly in liver. However, the largest concentration of cholesterol in mammals is found in brain. Furthermore, as lipoprotein transport of cholesterol to brain tissue is limited to great extent by blood-brain barrier, the majority of brain cholesterol is synthesized de novo in brain. As cholesterol homeostasis in brain is not fully clarified, a study of brain cholesterol production was undertaken, based on CYP51 expression in several brain regions of mice of different age. After tissue collection, RNA isolation and quantification using Agilent RNA chip, cDNA was synthesized. Quantification of CYP51 expression was performed using real-time PCR method with SYBR Green as fluorescent reporter of target amplification in real time. Data were interpreted as relative CYP51 expression using comparative CT method. The results indicate tissue specific differences in CYP51 expression in cerebrum, cerebellum and brain stem, with the highest expression in brain stem corresponding to high contents of white matter in that region. Age specific differences are present in all of the three brain regions. This observation implies that cholesterogenesis in brain (varying in its intensity) takes place during the whole life-span with substantial decline in aged mice, which correlates to decrease of brain cholesterol production during aging. Our intention is to extend our study to other important genes in brain cholesterol homeostasis on the level of transcriptome and proteome in normal and neuropathologically altered brain tissue. Hopefully, this will enable a better understanding of the involvement of quantitative and qualitative changes of brain cholesterol in brain development, regeneration of damaged neurons, brain aging and neurodegenerative processes.

CYP51; mouse brain; cholesterogenesis

nije evidentirano