Journal: International Journal of Molecular Sciences
Article Title: Augmenting Vacuolar H + -ATPase Function Prevents Cardiomyocytes from Lipid-Overload Induced Dysfunction
doi: 10.3390/ijms21041520
Figure Lengend Snippet: Status and activity of v-ATPase in lipid-overexposed cardiomyocytes. ( A , B ) Fractionation in adult rat cardiomyocytes (aRCMs): aRCMs were incubated for 24h with either low palmitate (LP, palmitate/BSA ratio 0.3:1), high palmitate (HP, palmitate/BSA ratio 3:1), or HP with the addition of 25mM glucose (HP/HG). Contents of v-ATPase subunit a2 (V 0 -a2) and subunit B2 (V 1 -B2) were assessed by Western blotting in total cell lysates (Lys), in the cytoplasmic fraction (Cyt) and in the membrane fraction (M). GAPDH and Caveolin-3 were detected as loading control for V 1 -B2 and V 0 -a2, respectively. ( A ) Representative blots of three independent experiments are shown. ( B ) Quantification: The ratio of V 1 -B2 (membrane/cytoplasm) ( n = 3). ( C , D ) Immunoprecipitation (IP) of v-ATPase subunit d1 (V 0 -d1) or subunit B2 from HL-1 cells after incubation for 24 h with either basal (Ctrl) medium, Ctrl medium supplemented with 25 mM glucose (Ctrl/HG), HP medium containing 500µM palmitate and 100 nM insulin, or HP medium supplemented with 25 mM glucose (HP/ HG). IP samples were immunoblotted with antibodies against v-ATPase subunits V 0 -d1 and V 1 -B2 ( n = 4). ( E , F ) Chloroquine (CHLQ) accumulation in lipid-overexposed aRCMs: ( E ) aRCMs were incubated for 24h with LP medium (LP), LP supplemented with 100nM Bafilomycin-A (BafA), LP/HG, HP, and HP/HG; ( F ) aRCMs were incubated for 48 h with either LP medium with the addition of 120 µL AdGFP (AdGFP), AdGFP supplemented with 100 nM Bafilomycin-A (BafA), LP medium with the addition of 120 µL AdPKD (AdPKD), HP with the addition of 120 µL AdGFP (AdGFP/HP), or HP with the addition of 120 µL AdPKD (AdPKD/HP). After the culturing of all conditions above, cells were sub for [ 3 H] CQ accumulation assay last 20 min. Values are displayed as mean ± SEM ( n = 4). * p < 0.05 were considered statistically significant.
Article Snippet: Primary antibodies were detected by either anti-rabbit secondary antibody for PKD/PKC-μ, T-AKT, pAKT, pS6, IRAP and GAPDH (Cell Signaling Technology) or anti-rabbit secondary antibody for V 0 -a2, V 0 -d1, and V 1 -B2 (Dako Corp., Carpinteria, CA, USA), or anti-mouse secondary antibody for caveolin-3 (BD Transduction Laboratories Dako Corp., Carpinteria, CA, USA).
Techniques: Activity Assay, Fractionation, Incubation, Western Blot, Membrane, Control, Immunoprecipitation