Figure 12.

GH signaling is compromised in Lmna-deficient hepatocytes and livers. (A) Primary hepatocytes were isolated from 8- to 12-week-old WT and KO male mice, serum-starved for 8–12 hours, treated with 0, 25, 50, or 250 ng/mL of human GH (37°C, 10 min), and then lysed to prepare cytoplasmic and nuclear extracts for immunoblotting. Primary hepatocyte isolation experiments were repeated 5 times, and results shown are representative. (B) Primary hepatocytes were isolated from 8- to 12-week-old WT and KO female mice, serum-starved for 8–12 hours, treated with 0, 50, or 250 ng/mL of human GH (37°C, 10 min), and then lysed to prepare cytoplasmic and nuclear extracts for immunoblotting. Primary hepatocyte isolation experiments were repeated 2 times. (C) Cytoplasmic liver extracts were prepared from WT and KO male mice (20–24 weeks old) that were injected intraperitoneally with either PBS or GH (2.5 mg/kg). Livers were harvested 10 minutes after injection. Extracts then were analyzed by immunoblotting as indicated in the Materials and Methods section. (D) Relative band intensities for phosphorylated and total Jak2, Akt, Stat5, and Erk for immunoblots shown in panel C were determined using ImageJ software, and relative band intensities for the phosphorylated proteins were normalized to total Jak2, Akt, Stat5, or Erk. Note that GH induced Jak2, Stat5, and Erk phosphorylation in WT but not KO livers. **P < .01 for WT PBS vs GH for phosphorylated Stat5 and phosphorylated Erk analysis, and ****P < .0001 for WT PBS vs GH for phosphorylated Jak2 analysis. Error bars in all graphs represent SD. Statistical significance was determined using 1-way analysis of variance followed by the Tukey post hoc test.