Limits...
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

AICAR upregulates the mRNA levels of the three PPARs in HL-1 cardiomyocytes. Analysis of the mRNA levels of Ppara (a), Ppard (b), and Pparg (c) by real-time RT-PCR in HL-1 cells stimulated by AICAR for 24 h in the presence or absence of Compound C. Data are normalized by the Cyclophilin A mRNA levels and expressed as mean ± SD of 4 different experiments. (∗P < 0.05, ∗∗∗P < 0.001 versus control nonstimulated cells; #P < 0.05 versus AICAR-treated cells).
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4663352&req=5

fig2: AICAR upregulates the mRNA levels of the three PPARs in HL-1 cardiomyocytes. Analysis of the mRNA levels of Ppara (a), Ppard (b), and Pparg (c) by real-time RT-PCR in HL-1 cells stimulated by AICAR for 24 h in the presence or absence of Compound C. Data are normalized by the Cyclophilin A mRNA levels and expressed as mean ± SD of 4 different experiments. (∗P < 0.05, ∗∗∗P < 0.001 versus control nonstimulated cells; #P < 0.05 versus AICAR-treated cells).

Mentions: AICAR-induced AMPK activation in HL-1 cardiac cells has been previously reported by others [24]. To confirm this in our hands, HL-1 cells were treated with AICAR for 1 h and AMPK phosphorylation was analyzed. AICAR treatment induced AMPK phosphorylation in Thr 172 (~2-fold, P < 0.01) (Figure 1(a)) as well as phosphorylation in Ser 79 of its well-known target ACC (~1.6-fold, P < 0.05) (Figure 1(b)), confirming that AICAR stimulation activates AMPK in HL-1 cardiomyocytes. Because AMPK is able to drive the long-term metabolic adaptation through PPAR regulation [10–14], we explored the effect of AICAR stimulation for 24 h on PPAR expression. Treatment with AICAR strongly induced the Ppara (~4.9-fold, P < 0.001) (Figure 2(a)), Ppard (~4.1-fold, P < 0.05) (Figure 2(b)), and Pparg (~17.5-fold, P < 0.001) (Figure 2(c)) mRNA levels. However, while AICAR-induced Ppara and Pparg expression was attenuated in the presence of the AMPK inhibitor Compound C (Figures 2(a) and 2(c)), this drug was unable to prevent the AICAR-induced Ppard upregulation (Figure 2(b)).


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)

AICAR upregulates the mRNA levels of the three PPARs in HL-1 cardiomyocytes. Analysis of the mRNA levels of Ppara (a), Ppard (b), and Pparg (c) by real-time RT-PCR in HL-1 cells stimulated by AICAR for 24 h in the presence or absence of Compound C. Data are normalized by the Cyclophilin A mRNA levels and expressed as mean ± SD of 4 different experiments. (∗P < 0.05, ∗∗∗P < 0.001 versus control nonstimulated cells; #P < 0.05 versus AICAR-treated cells).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig2: AICAR upregulates the mRNA levels of the three PPARs in HL-1 cardiomyocytes. Analysis of the mRNA levels of Ppara (a), Ppard (b), and Pparg (c) by real-time RT-PCR in HL-1 cells stimulated by AICAR for 24 h in the presence or absence of Compound C. Data are normalized by the Cyclophilin A mRNA levels and expressed as mean ± SD of 4 different experiments. (∗P < 0.05, ∗∗∗P < 0.001 versus control nonstimulated cells; #P < 0.05 versus AICAR-treated cells).
Mentions: AICAR-induced AMPK activation in HL-1 cardiac cells has been previously reported by others [24]. To confirm this in our hands, HL-1 cells were treated with AICAR for 1 h and AMPK phosphorylation was analyzed. AICAR treatment induced AMPK phosphorylation in Thr 172 (~2-fold, P < 0.01) (Figure 1(a)) as well as phosphorylation in Ser 79 of its well-known target ACC (~1.6-fold, P < 0.05) (Figure 1(b)), confirming that AICAR stimulation activates AMPK in HL-1 cardiomyocytes. Because AMPK is able to drive the long-term metabolic adaptation through PPAR regulation [10–14], we explored the effect of AICAR stimulation for 24 h on PPAR expression. Treatment with AICAR strongly induced the Ppara (~4.9-fold, P < 0.001) (Figure 2(a)), Ppard (~4.1-fold, P < 0.05) (Figure 2(b)), and Pparg (~17.5-fold, P < 0.001) (Figure 2(c)) mRNA levels. However, while AICAR-induced Ppara and Pparg expression was attenuated in the presence of the AMPK inhibitor Compound C (Figures 2(a) and 2(c)), this drug was unable to prevent the AICAR-induced Ppard upregulation (Figure 2(b)).

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