Journal: Cellular and Molecular Gastroenterology and Hepatology
Article Title: A Dual-compartment Scaffolding Role for Receptor for Activate C Kinase 1 in Hepatic Glucagon Signaling and Gluconeogenesis
doi: 10.1016/j.jcmgh.2025.101666
Figure Lengend Snippet: RACK1 deficiency attenuates hepatic PKA signaling. ( A–B ) RACK1 fl/fl mice injected with AAV8-TBG-iGFP (GFP) or AAV8-TBG-iCre (Cre) and fasted for 2 hours (basal) or treated with glucagon (100 μg/kg body weight; Glu) or insulin (1.5 U/kg body weight) for 15 minutes. Liver lysates were analyzed for cAMP levels ( A ) and by Western blotting ( B ). Quantified Western blot data are shown in the left panel. ∗∗∗ P < .001 vs corresponding basal. & P < .001 vs GFP + glucagon; 2-way ANOVA followed by Sidak’s post hoc test. ( C ) cAMP levels in primary hepatocytes stimulated with vehicle (basal) or glucagon (200 nM) for 10 minutes. ∗∗∗ P < .001 vs GFP + basal; 2-way ANOVA followed by Sidak’s post hoc test. ( D ) Western blot analysis of primary hepatocytes from GFP and Cre mice stimulated with vehicle (basal) or glucagon (200 nM) for the indicated times. Relative phosphorylation of pCREB S133 and phosphor-PKA substrates (pPKA sub) is expressed as fold change over GFP at 0 minutes, normalized to total protein ( left panel ). ∗, ∗∗∗ P < .05 and .001 vs Glu at 0 minutes, respectively; $ P < .001 vs Cre at 0 minutes; # P < .01 vs corresponding GFP; 2-way ANOVA followed by Sidak’s post hoc test. Arrows indicate pPKA sub unchanged or increased in RACK1-deficient cells. ( E ) Western blot analysis of primary hepatocytes from GFP and Cre mice stimulated with vehicle (basal), or insulin (20 nM) for the indicated times. Relative phosphorylation of pAKT S473 is expressed as fold change over GFP at 0 minutes, normalized to total protein (lower panel). ∗∗∗, # P < .001 vs corresponding Ins at 0 minutes; 2-way ANOVA followed by Sidak’s post hoc test. ( F ) qPCR analysis of PKA target genes G6PC and PCK1 in hepatocytes treated for 4 hours with vehicle, insulin (20 nM), glucagon (100 nM), glucagon + insulin, cAMP (20 μM), or cAMP + insulin. ∗∗∗ P < .001 vs corresponding basal; # P < .001 vs corresponding GFP; % P < .001 vs corresponding cAMP or glucagon; 2-way ANOVA followed by Sidak’s post hoc test. ( G ) qPCR analysis of the indicated genes in liver tissues from GFP and Cre mice following a 6-hour fast. ∗, ∗∗, ∗∗∗ P < .05, .01 and .001 vs GFP, respectively; 2-tailed Student’s t -test.
Article Snippet: Acute deletion of RACK1 gene in the liver was achieved through the injection of AAV viruses (1 × 10 11 genome copies/mouse) encoding Cre recombinase under the TBG promoter (AAV-TBG-iCre; Vector Biolabs) into the retroorbital vein of RACK1 fl/fl transgenic mice.
Techniques: Injection, Western Blot, Phospho-proteomics