Conclusions
The current findings identify the PI3K/AKT pathway as critical to the induction by TSH of IL-1RA in fibrocytes and GD-OFs. Furthermore, PTEN modulates the amplitude of the induction. In GD-OFs, relatively high basal PTEN levels prevent secreted IL-1RA expression or release. Knocking down PTEN allows GD-OFs to exhibit a pattern of IL-1RA expression resembling fibrocytes.
Results
TSH induces IL-1RA in fibrocytes and GD-OFs by activating the PI3K/AKT pathway. Interrupting either PI3K or AKT with small molecule inhibitors or by knocking down their expression with targeting small interfering RNA attenuates the actions of TSH. OFs exhibit greater basal PTEN activity and lower constitutive AKT phosphorylation than do fibrocytes. Patterns of PTEN induction diverge in the two cell types. Conclusions: The current findings identify the PI3K/AKT pathway as critical to the induction by TSH of IL-1RA in fibrocytes and GD-OFs. Furthermore, PTEN modulates the amplitude of the induction. In GD-OFs, relatively high basal PTEN levels prevent secreted IL-1RA expression or release. Knocking down PTEN allows GD-OFs to exhibit a pattern of IL-1RA expression resembling fibrocytes.