Ritchie Lab

The University of Michigan School of Dentistry



The Ritchie laboratory is focused on studying two major dentin noncollagenous proteins, dentin sialoprotein (DSP) and physophporyn (PP) which appear to play a significant role in the conversion of uncalcified predentin to calcified dentin. Later additional functions were discovered in Ritchie laboratory.


Helena Ritchie, MS, PhD
Associate Professor

helenar@umich.edu | 734-763-3746

Dr. Ritchie's laboratory has a significant record of achievement over the past two decades in cloning the dentin sialoprotein (DSP) and phosphophoryn (PP) genes, describing their genomic organization and gene regulation, clarifying DSP-PP precursor processing, and most recently investigating how these activities regulate tooth development. To successfully pursue these research areas, we developed novel methods (i.e., we were the first to utilize the Sf9 baculovirus system to fully characterize DSP-PP precursor protein cleavage), animal models (i.e., mutant DSP-PP transgenic and knockout mice) and reagents (i.e., multiple DSP-PP gene mutants). Because of our in depth expertise in this area, we have recently been able to discover that DSP-PP (also termed DSPP) knockout (KO) mice could not maintain the odontoblast lineage in dental pulp. Moreover we identified the appearance of chondrocyte-like cells in dental pulp suggesting that DSPP likely plays a heretofore unknown role in dental pulp differentiation during tooth development. Furthermore, we recently discovered that DSPP dosage affects epithelia-mesenchymal cell interactions, maintenance of odontoblast lineage in dental pulp and dental mineralization in vivo. Given this background, we are well positioned to pursue and characterize how DSPP is involved in tooth development and mineralization.


View the complete listing of publications.


Ritchie Lab
University of Michigan School of Dentistry
1011 N University Ave,
Ann Arbor, MI 48109