analysis of pparγ gene expression in stem cells during neurogenesis step

mouse embryonic stem cells (es) are pluripotent cell lines derived from the inner cell mass of the blastocyst. their properties include self renewal and capacity to differentiate into different cell types. neural differentiation of es cells has been achieved by several different protocols such as treating with retinoic acid and serum decreasing in culture media. the ppars (peroxisome proliferator-activated receptors) are members of the nuclear hormone receptor superfamily. three major isoforms of ppars (α, β and γ) have been identified. ppar γ has been demonstrated to play an important role in the regulation of cell differentiation. ppar γ has 2 isoforms termed: γ1, γ2. ppar γ2 is primarily expressed in adipocytes but ppar γ1 is expressed in various cell types such as neuron and astroglial cells. in order to understand the molecular mechanisms of ppar γ during neurogenesis, we set serial experiments to evaluate the relative expression patterns of these genes. embryonic stem cells were cultured to form multicellular aggregates, called embryoid bodies (ebs). then, formed embroyid bodies were treated with retinoic acid (ra) for 4 days and cells were plated to differentiate into neurons. rna extraction and cdna synthesis were performed. cdna was used as a template for rt-pcr and real time pcr. semi-quantitative data showed that ppar γ1 expression increased in nerve cells relative to embryonic stem cells. however, no expression of ppar γ2 was observed. moreover, to further evaluate ppar γ2 expression, real time pcr was carried out but no expression for this variant was found. thus, our results confirmed previous data that there is no expression in nerve tissues.