High Mobility Group A1 Regulates Transcription Levels of Oligodendrocyte Marker Genes in Cultured Oligodendrocyte Precursor Cells.

Oligodendrocyte precursor cells (OPCs) serve as progenitor cells of terminally differentiated oligodendrocytes. Past studies have confirmed the importance of epigenetic system in OPC differentiation to oligodendrocytes. High mobility group A1 (HMGA1) is a small non-histone nuclear protein that binds DNA and modifies the chromatin conformational state. However, it is still completely unknown about the roles of HMGA1 in the process of OPC differentiation. In this study, we prepared primary OPC cultures from the neonatal rat cortex and examined whether the loss- and gain-of-function of HMGA1 would change the mRNA levels of oligodendrocyte markers, such as , , and during the process of OPC differentiation. In our system, the mRNA levels of , , and increased depending on the oligodendrocyte maturation step, but the level of mRNA decreased. When HMGA1 was knocked down by a siRNA approach, the mRNA levels of , , and were smaller in OPCs with siRNA compared to the ones in the control OPCs. On the contrary, when HMGA1 expression was increased by transfection of the plasmid, the mRNA levels of , , and were slightly larger compared to the ones in the control OPCs. These data may suggest that HMGA1 participates in the process of OPC differentiation by regulating the mRNA expression level of myelin-related genes.