The role of the Grb2–p38 MAPK signaling pathway in cardiac hypertrophy and fibrosis
J. Clin. Invest. Shaosong Zhang, et al. 111:833 doi:10.1172/JCI16290 [
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Figure 1Biochemical characterization of Grb2 and MAPK in murine cardiac tissue 7 days after TAC or sham operation. (
a) Load-induced formation of a Grb2-FAK complex. Anti-FAK immunoprecipitates (IP) derived from ventricular lysates were separated by SDS-PAGE and analyzed by immunoblotting with an anti-Grb2 antibody (lower panel). Anti-FAK immunoprecipitates were also analyzed in parallel by immunoblotting with an anti-FAK antibody (upper panel). (
b) Reduced Grb2 protein content in
Grb2+/– cardiac tissue. Upper panel, ventricular lysates were analyzed by immunoblotting with an anti-Grb2 antibody. Lower panel, quantification of Grb2 protein levels by densitometric analysis of immunoreactive bands. (
c) Analysis of p38 MAPK activation in
Grb2+/– cardiac tissue. Ventricular lysates were analyzed by immunoblotting with an anti-phospho–p38 MAPK antibody (upper panel). Lysates were also analyzed in parallel by immunoblotting with an anti–p38 MAPK (lower panel) antibody to control for protein content. (
d) Analysis of JNK activation in
Grb2+/– cardiac tissue. Lysates were analyzed by immunoblotting with an anti–phospho-JNK antibody (upper panel). Lysates were also analyzed in parallel by immunoblotting with an anti-JNK (lower panel) antibody to control for protein content. (
e) Analysis of ERK activity in
Grb2+/– cardiac tissue. Anti-ERK immunoprecipitates derived from ventricular lysates were analyzed by in vitro kinase assay by use of Elk-1 protein as a substrate. Anti-phospho–Elk-1 antibody immunoblotting was performed to assess ERK activity (upper panel). Lysates were also analyzed in parallel by immunoblotting with an anti-ERK (lower panel) antibody to control for protein content. Sham, sham operation.
