analysis of peroxisomal protein gene expression during neural differentiation: direct implication of peroxisomal proteins regulation and neurogenesis

peroxisomes are small size organelles in nearly all eukaryotic cells involved in various metabolic functions including β-oxidation of very long chain fatty acids and metabolite peroxidation and plasmalogens synthesis. the latter is one of the major constituents in neural cell membranes. the biogenesis of peroxisomes is a complex process which requires multiple proteins encoded by pex genes. dysfunction in several pex genes due to mutations have been reported to be associated with some human disorders characterized by neurologic deficits termed peroxisomal biogenesis disorders like zellweger syndrome. therefore, it has been postulated that peroxisome organelles may play an essential role in neurogenesis. one of the recently identified peroxisomal matrix proteins is termed peroxisomal protein (pep). previous studies have shown that pep is mainly expressed in brain tissues of adult mice and a possible role for pep in neurogenesis is suggested. in this study, we assessed the expression level of pep during neural differentiation process of mouse embryonic carcinoma cell (p19) and mouse embryonic stem cells (royan b1) into neural cells. time course study of pep expression revealed that its expression markedly increased prior to elevation of map2 expression enhancement. it was shown to be associated with the stage when aggregates or ebs were treated with retinoic acid. it is of interest to note that pep has a fibronectin type iii domain, but whether this domain plays a critical interaction in aggregate formation of neurogenesis step needs further investigation.