Figure 5.

TSHR/IGF1R crosstalk is necessary for Tepro inhibition of GO antibodies. β-arrestin 1 (ARRB1) gene knockdown in TEDOFs was performed as described in the Fig. 4 legend. Cells were incubated with purified antibodies (TED-Igs) isolated from the sera of 30 patients with or without 1 µg/mL Tepro. Secreted hyaluronan (HA) was measured as described in Materials and Methods. Cells treated with ARRB1 siRNA exhibited at least a 70% decrease in ARRB1 mRNA. Data were normalized to percent maximum of M22 in cells exposed to nontargeting (NT) siRNA, and bars represent mean ± SEM computed from the averages of triplicate measurements in 3 different TEDOF strains. Under control conditions (black bars), TED-Ig stimulation of HA secretion was 87% of M22 and partially inhibited by Tepro, P = 0.0004. In cells without β-arrestin 1 (gray bars), TED-Igs stimulation was 70% and not significantly different with Tepro (78%).