Alteration of LAR-RPTP Expression in the Rat Trigeminal Ganglion after Tooth Extraction

LAR-RPTP (leukocyte common antigen-related receptor protein tyrosine phosphatase) is an important regulator in the nervous system, but little is known about its expression pattern in rat trigeminal ganglion (TG) neurons. To examine whether LAR-RPTP is expressed in the TG in the current study, we sacrificed rats at 0, 7, 10 and 56 day postpartum (dpp) and a second group of rats at 3 and 5 days after an experimental tooth extraction as a TG injury model. RT-PCR was then used to determine the level of LAR-RPTP expression in the TG and immunohistology was employed to detect the subcellular localization of the protein. The mRNA expression of LAR-RPTP during the developmental stages in the TG was found to gradually increase. After experimental tooth extraction however, these transcript levels had significantly decreased at three days. LAR-RPTP protein signals in the TG were found to be cytoplasmic in the normal animals but interestingly, at five days after an experimental tooth extraction, these signals were rare. These results indicate that LAR-RPTP may be regulated during both the developmental as well as regenerative processes that take place in the TG. This further suggests that LAR-RPTP is not only involved in primary axonogenesis but possibly also in the molecular control of axons during TG repair.