Gene-expression analysis of early- and late-maturation-stage rat enamel organ


Rodrigo S. Lacruz, 2250 Alcazar St CSA # 103, Los Angeles, CA 90033, USA
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Lacruz RS, Smith CE, Chen Y-B, Hubbard MJ, Hacia JG, Paine ML. Gene-expression analysis of early- and late-maturation-stage rat enamel organ
Eur J Oral Sci 2011; 119 (Suppl. 1): 149–157. © 2011 Eur J Oral Sci

Enamel maturation is a dynamic process that involves high rates of mineral acquisition, associated fluctuations in extracellular pH, and resorption of extracellular enamel proteins. During maturation, ameloblasts change from having a tall, thin, and highly polarized organization, characteristic of the secretory stage, to having a low columnar and widened morphology in the maturation stage. To identify potential differences in gene expression throughout maturation, we obtained enamel organ epithelial cells derived from the early- and late-maturation stages of rat incisor and analyzed the global gene-expression profiles at each stage. Sixty-three candidate genes were identified as having potential roles in the maturation process. Quantitative PCR was used to confirm the results of this genome-wide analysis in a subset of genes. Transcripts enriched during late maturation (n = 38) included those associated with lysosomal activity, solute carrier transport, and calcium signaling. Also up-regulated were transcripts involved in cellular responses to oxidative stress, proton transport, cell death, and the immune system. Transcripts down-regulated during the late maturation stage (n = 25) included those with functions related to cell adhesion, cell signaling, and T-cell activation. These results indicate that ameloblasts undergo widespread molecular changes during the maturation stage of amelogenesis and hence provide a basis for future functional investigations into the mechanistic basis of enamel mineralization.