Stra6-null mice are protected from activation of STAT and suppression of insulin signaling by holo-RBP.
A, left panel, immunoblots demonstrating the level of RBP in serum of three individual WT and Stra6-null male mice injected with buffer (−) or with recombinant histidine-tagged RBP (holo-RBP). Coomassie Blue staining of serum albumin provided a loading control. Right panel, quantitation of immunoblots showing total serum RBP levels in denoted groups. †, p < 0.05 holo-RBP-treated Stra6-null versus WT mice. B–E, levels of mRNAs for Socs3 (B and C) and Pparg (D and E) in WAT (B and D) and skeletal muscle (C and E) of WT and Stra6-null mice treated with buffer (black bars) or with holo-RBP (gray bars). Data are means ± S.E. (n = 3/group). #, p < 0.05 holo-RBP-treated versus buffer-treated WT mice; *, p < 0.05 buffer-treated Stra6-null versus WT mice; †, p < 0.05 holo-RBP-treated Stra6-null versus WT mice. F and H, immunoblots of pJAK2, JAK2, pIR, IR, pAKT, and AKT in WAT (F) and skeletal muscle (H) of WT and Stra6-null mice (6-null) treated with buffer or with holo-RBP. G and I, quantitation of immunoblots in F and H, respectively. Means ± S.D. *, p < 0.05; **, p < 0.01; ***, p < 0.001 versus buffer-treated WT mice. ††, p < 0.01; †††, p < 0.001 versus holo-RBP-treated WT mice.