Mediators of inflammation and regeneration.

Characterization of the molecular response under caries lesions requires a robust and reliable transcript isolation system, and analysis of data indicated that collection of extracted teeth in either liquid nitrogen/RNA-stabilizing solution facilitated this. Subsequent transcriptional analysis indicated higher general activity in carious pulps, while characterization of inflammatory mediators, including cytokines and S100 proteins, highlighted increasing expression levels associated with both microbial front progression and elevated cellular immune response. Analysis of the pleiotropic hormone adrenomedullin (ADM) indicated that transcript and protein levels are increased in pulpal tissue during caries, and that protein levels sequestered in dentin due to primary dentinogenesis are comparable with those of TGF-β1. Expression analysis of a leucine-rich-repeat-containing protein (LRRC15/Lib) indicated that this highly conserved molecule was up-regulated during caries, is transcriptionally regulated by pro-inflammatory stimuli, and is relatively abundant in mineralized tissues.