Smooth muscle-specific knockout of IRS-1 but not IRS-2 stimulates the dedifferentiation of aortic smooth muscle cells.
A, B, D, and E, aortae from normal wild-type mice (WT+/+
NG), diabetic wild-type mice (WT+/+
HG), normal IRS-1 knockout mice (IRS-1−/−
NG), IRS-2 knockout mice (IRS-2−/−
NG), or diabetic IRS-2 knockout mice (IRS-2−/−
HG) were prepared following the procedure described under “Experimental Procedures.” The lysates were immunoblotted (IB) with anti-KLF4, anti-myocardin (A and B) or anti-SM22 antibody (D and E). The blots were reprobed with an anti-β-actin antibody as a loading control. The value of each column is the ratio of the mean ± S.D. value of the scanning units obtained from 6 mice/group for KLF4, myocardin, or SM22 divided by the scanning units of corresponding β-actin, respectively. *, p < 0.05; **, p < 0.01; ***, p < 0.001; significant differences between two mouse types. C and F, aortic lysates from diabetic wild-type mice (WT+/+
HG) or non-diabetic IRS-1 knockout mice (IRS-1−/−
NG) treated with SHPS-1/SHP2-disrupting peptide (AP) or a control peptide (CP) for 5 days were immunoblotted with anti-KLF4, anti-myocardin (C), or anti-SM22 antibody (F). The blots were reprobed with an anti-β-actin antibody as a loading control. M1 and M2 denote two representative mice for each group.