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AICAR Protects against High Palmitate/High Insulin-Induced Intramyocellular Lipid Accumulation and Insulin Resistance in HL-1 Cardiac Cells by Inducing PPAR-Target Gene Expression.

Rodríguez-Calvo R, Vázquez-Carrera M, Masana L, Neumann D - PPAR Res (2015)

Bottom Line: Treatment with AICAR induced gene expression of all three PPARs, but only the Ppara and Pparg regulation were dependent on AMPK.AICAR treatment induced the expression of Acadvl and Glut4, which correlated to prevention of the HP/HI-induced intramyocellular lipid build-up, and attenuation of the HP/HI-induced impairment of glucose uptake.These data support the hypothesis that AICAR contributes to cardiac metabolic adaptation via regulation of transcriptional mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics, CARIM School for Cardiovascular Diseases, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200 MD Maastricht, Netherlands.

ABSTRACT
Here we studied the impact of 5-aminoimidazole-4-carboxamide riboside (AICAR), a well-known AMPK activator, on cardiac metabolic adaptation. AMPK activation by AICAR was confirmed by increased phospho-Thr(172)-AMPK and phospho-Ser(79)-ACC protein levels in HL-1 cardiomyocytes. Then, cells were exposed to AICAR stimulation for 24 h in the presence or absence of the AMPK inhibitor Compound C, and the mRNA levels of the three PPARs were analyzed by real-time RT-PCR. Treatment with AICAR induced gene expression of all three PPARs, but only the Ppara and Pparg regulation were dependent on AMPK. Next, we exposed HL-1 cells to high palmitate/high insulin (HP/HI) conditions either in presence or in absence of AICAR, and we evaluated the expression of selected PPAR-targets genes. HP/HI induced insulin resistance and lipid storage was accompanied by increased Cd36, Acot1, and Ucp3 mRNA levels. AICAR treatment induced the expression of Acadvl and Glut4, which correlated to prevention of the HP/HI-induced intramyocellular lipid build-up, and attenuation of the HP/HI-induced impairment of glucose uptake. These data support the hypothesis that AICAR contributes to cardiac metabolic adaptation via regulation of transcriptional mechanisms.

No MeSH data available.


Related in: MedlinePlus

Treatment with AICAR regulates the expression of PPAR-target genes. Analysis of the mRNA levels of Cd36 (a), Acot1 (b), Cpt-1b (c), Acox1 (d), Acadvl (e), Ucp3 (f), Glut4 (f), and Pdk4 (h) by real-time RT-PCR in HL-1 cells stimulated with HP/HI for 16 h in the presence or absence of AICAR (24 h). Data are normalized by the Cyclophilin A mRNA levels and expressed as mean ± SD of 4 different experiments. (∗P < 0.05, ∗∗P < 0.01 versus control nonstimulated cells; #P < 0.05, ##P < 0.01 versus HP/HI-stimulated cells).
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fig3: Treatment with AICAR regulates the expression of PPAR-target genes. Analysis of the mRNA levels of Cd36 (a), Acot1 (b), Cpt-1b (c), Acox1 (d), Acadvl (e), Ucp3 (f), Glut4 (f), and Pdk4 (h) by real-time RT-PCR in HL-1 cells stimulated with HP/HI for 16 h in the presence or absence of AICAR (24 h). Data are normalized by the Cyclophilin A mRNA levels and expressed as mean ± SD of 4 different experiments. (∗P < 0.05, ∗∗P < 0.01 versus control nonstimulated cells; #P < 0.05, ##P < 0.01 versus HP/HI-stimulated cells).

Mentions: Next, HL-1 cardiomyocytes were challenged with HP/HI to render the cells insulin resistant, in the presence or absence of AICAR, and the expression of selected PPAR-target genes involved in glucose and fatty acid metabolism was analyzed by real-time PCR. HP/HI stimulation induced the expression of the fatty acid transporter Cd36 (~1.4-fold; P < 0.05 versus CT) (Figure 3(a)), Acot1 (~1.9-fold; P < 0.05 versus CT) (Figure 3(b)), and Ucp3 (~3.2-fold; P < 0.01 versus CT) (Figure 3(f)). Nevertheless, HP/HI stimulation did not alter the expression of other genes involved in fatty acid and glucose metabolism, such as Cpt1b (Figure 3(c)), Acox1 (Figure 3(d)), Acadvl (Figure 3(e)), Glut4 (Figure 3(g)), and Pdk4 (Figure 3(h)). Treatment with AICAR induced the expression of key genes involved in fatty acid metabolism, such as Cd36 (~1.4-fold; P < 0.05 versus CT) (Figure 3(a)), Cpt1b (~1.5-fold; P < 0.05 versus CT) (Figure 3(c)), Acox1 (~1.3-fold; P < 0.05 versus CT) (Figure 3(d)), and Acadvl (~1.8-fold; P < 0.05 versus CT; ~1.8-fold; P < 0.01 versus HP/HI) (Figure 3(e)), and glucose transport, such as Glut4 (~4.5-fold; P < 0.05 versus HP/HI) (Figure 3(g)).


AICAR Protects against High Palmitate/High Insulin-Induced Intramyocellular Lipid Accumulation and Insulin Resistance in HL-1 Cardiac Cells by Inducing PPAR-Target Gene Expression.

Rodríguez-Calvo R, Vázquez-Carrera M, Masana L, Neumann D - PPAR Res (2015)

Treatment with AICAR regulates the expression of PPAR-target genes. Analysis of the mRNA levels of Cd36 (a), Acot1 (b), Cpt-1b (c), Acox1 (d), Acadvl (e), Ucp3 (f), Glut4 (f), and Pdk4 (h) by real-time RT-PCR in HL-1 cells stimulated with HP/HI for 16 h in the presence or absence of AICAR (24 h). Data are normalized by the Cyclophilin A mRNA levels and expressed as mean ± SD of 4 different experiments. (∗P < 0.05, ∗∗P < 0.01 versus control nonstimulated cells; #P < 0.05, ##P < 0.01 versus HP/HI-stimulated cells).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4663352&req=5

fig3: Treatment with AICAR regulates the expression of PPAR-target genes. Analysis of the mRNA levels of Cd36 (a), Acot1 (b), Cpt-1b (c), Acox1 (d), Acadvl (e), Ucp3 (f), Glut4 (f), and Pdk4 (h) by real-time RT-PCR in HL-1 cells stimulated with HP/HI for 16 h in the presence or absence of AICAR (24 h). Data are normalized by the Cyclophilin A mRNA levels and expressed as mean ± SD of 4 different experiments. (∗P < 0.05, ∗∗P < 0.01 versus control nonstimulated cells; #P < 0.05, ##P < 0.01 versus HP/HI-stimulated cells).
Mentions: Next, HL-1 cardiomyocytes were challenged with HP/HI to render the cells insulin resistant, in the presence or absence of AICAR, and the expression of selected PPAR-target genes involved in glucose and fatty acid metabolism was analyzed by real-time PCR. HP/HI stimulation induced the expression of the fatty acid transporter Cd36 (~1.4-fold; P < 0.05 versus CT) (Figure 3(a)), Acot1 (~1.9-fold; P < 0.05 versus CT) (Figure 3(b)), and Ucp3 (~3.2-fold; P < 0.01 versus CT) (Figure 3(f)). Nevertheless, HP/HI stimulation did not alter the expression of other genes involved in fatty acid and glucose metabolism, such as Cpt1b (Figure 3(c)), Acox1 (Figure 3(d)), Acadvl (Figure 3(e)), Glut4 (Figure 3(g)), and Pdk4 (Figure 3(h)). Treatment with AICAR induced the expression of key genes involved in fatty acid metabolism, such as Cd36 (~1.4-fold; P < 0.05 versus CT) (Figure 3(a)), Cpt1b (~1.5-fold; P < 0.05 versus CT) (Figure 3(c)), Acox1 (~1.3-fold; P < 0.05 versus CT) (Figure 3(d)), and Acadvl (~1.8-fold; P < 0.05 versus CT; ~1.8-fold; P < 0.01 versus HP/HI) (Figure 3(e)), and glucose transport, such as Glut4 (~4.5-fold; P < 0.05 versus HP/HI) (Figure 3(g)).

Bottom Line: Treatment with AICAR induced gene expression of all three PPARs, but only the Ppara and Pparg regulation were dependent on AMPK.AICAR treatment induced the expression of Acadvl and Glut4, which correlated to prevention of the HP/HI-induced intramyocellular lipid build-up, and attenuation of the HP/HI-induced impairment of glucose uptake.These data support the hypothesis that AICAR contributes to cardiac metabolic adaptation via regulation of transcriptional mechanisms.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Genetics, CARIM School for Cardiovascular Diseases, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200 MD Maastricht, Netherlands.

ABSTRACT
Here we studied the impact of 5-aminoimidazole-4-carboxamide riboside (AICAR), a well-known AMPK activator, on cardiac metabolic adaptation. AMPK activation by AICAR was confirmed by increased phospho-Thr(172)-AMPK and phospho-Ser(79)-ACC protein levels in HL-1 cardiomyocytes. Then, cells were exposed to AICAR stimulation for 24 h in the presence or absence of the AMPK inhibitor Compound C, and the mRNA levels of the three PPARs were analyzed by real-time RT-PCR. Treatment with AICAR induced gene expression of all three PPARs, but only the Ppara and Pparg regulation were dependent on AMPK. Next, we exposed HL-1 cells to high palmitate/high insulin (HP/HI) conditions either in presence or in absence of AICAR, and we evaluated the expression of selected PPAR-targets genes. HP/HI induced insulin resistance and lipid storage was accompanied by increased Cd36, Acot1, and Ucp3 mRNA levels. AICAR treatment induced the expression of Acadvl and Glut4, which correlated to prevention of the HP/HI-induced intramyocellular lipid build-up, and attenuation of the HP/HI-induced impairment of glucose uptake. These data support the hypothesis that AICAR contributes to cardiac metabolic adaptation via regulation of transcriptional mechanisms.

No MeSH data available.


Related in: MedlinePlus