Transforming growth factor β3 increases chondrocyte proliferation and decreases apoptosis in murine cricoid cartilage in vitro

Abstract

To determine if the luminal epithelium and/or exogenous transforming growth factor beta (TGFbeta) affects growth of the cricoid. Subglottises from 20 neonatal mice were subdivided into four groups: A, five subglottises with luminal epithelium grown in basic medium; B, five epithelium-free subglottises in basic medium; C, five epithelium-free subglottises in basic medium with supplemental TGFbeta1, and D, five epithelium-free subglottises in basic medium with supplemental TGFbeta3. Groups A and D demonstrated the greatest luminal area expansion. Group A rings demonstrated statistically higher chondrocyte proliferation than Groups B and C and lesser amounts of luminal apoptosis. Groups B and C rings demonstrated the least amount of cell proliferation, and greater luminal apoptosis relative to Group A. Groups A and D rings had similar apoptotic and proliferative results. Luminal epithelium exerts influence over the cricoid by increasing chondrocyte proliferation and decreasing the relative proportion of luminal chondrocytes that undergo apoptosis. Exogenous TGFbeta3, not TGFbeta1, also increases chondrocyte proliferation within the cricoid and appears to influence apoptosis as well.