Purification and Characterization of Novel Genes of Human Fetal Astrocytes

ABSTRACT

Astrocytes are ubiquitous in the brain and have multiple functions. It is becoming clear that they play an important role in monitoring the neuromicroenvironment, information processing, and signaling in the central nervous system (CNS) in normal conditions and respond to CNS injuries. During the development of the CNS, astrocytes play a key role as a substrate for neuronal migration and axonal growth. To identify genes that could participate in astrocyte maturation, we used the differential display reverse transcription-PCR (DDRT-PCR) method. Human fetal astrocytes were cultured and total RNAs are isolated at intervals of 5 days for 50 days. Using 24 primer combinations, we have identified a set of 18 candidate cDNAs deriving from excised DDRT-PCR bands. DNA sequencing revealed 16 genes that have been described already (HMGCR, thyroid receptor interactor gene, NPM, transglutaminase mRNA, and SPARC etc.). We have also found two novel genes (A3 and C8), which were expressed differently in culture stages. A3 expressed decreasingly and C8 expressed increasingly in accordance with to culture stages. We have analysed these two genes. A3 (3,626 bp) showed 93% homology with the Homo sapiens general transcription factor 3 (GTF3) and C8 (2,401 bp) had 97% homology with the transmembrane receptor Unc5H2. Temporal expression of these two genes in this study suggests that the proteins of these genes may have different roles in maturation of the human fetal astrocytes.