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Cardioprotective Signature of Short-Term Caloric Restriction.

Noyan H, El-Mounayri O, Isserlin R, Arab S, Momen A, Cheng HS, Wu J, Afroze T, Li RK, Fish JE, Bader GD, Husain M - PLoS ONE (2015)

Bottom Line: This short-term model of CR was associated with cardio-protection, as evidenced by decreased infarct size (18.5±2.4% vs. 26.6±1.7%, N=10/group; P=0.01). mRNA and miR profiles pre-MI (N=5/group) identified genes modulated by short-term CR to be associated with circadian clock, oxidative stress, immune function, apoptosis, metabolism, angiogenesis, cytoskeleton and extracellular matrix (ECM).Western blots pre-MI revealed CR-associated increases in phosphorylated Akt and GSK3ß, reduced levels of phosphorylated AMPK and mitochondrial related proteins PGC-1α, cytochrome C and cyclooxygenase (COX) IV, with no differences in the levels of phosphorylated eNOS or MAPK (ERK1/2; p38).CR regimen was also associated with reduced protein abundance of cleaved caspase 3 in the infarcted heart and improved cardiac function.

View Article: PubMed Central - PubMed

Affiliation: Division of Experimental Therapeutics, Toronto General Research Institute, Toronto, Ontario, Canada.

ABSTRACT

Objective: To understand the molecular pathways underlying the cardiac preconditioning effect of short-term caloric restriction (CR).

Background: Lifelong CR has been suggested to reduce the incidence of cardiovascular disease through a variety of mechanisms. However, prolonged adherence to a CR life-style is difficult. Here we reveal the pathways that are modulated by short-term CR, which are associated with protection of the mouse heart from ischemia.

Methods: Male 10-12 wk old C57bl/6 mice were randomly assigned to an ad libitum (AL) diet with free access to regular chow, or CR, receiving 30% less food for 7 days (d), prior to myocardial infarction (MI) via permanent coronary ligation. At d8, the left ventricles (LV) of AL and CR mice were collected for Western blot, mRNA and microRNA (miR) analyses to identify cardioprotective gene expression signatures. In separate groups, infarct size, cardiac hemodynamics and protein abundance of caspase 3 was measured at d2 post-MI.

Results: This short-term model of CR was associated with cardio-protection, as evidenced by decreased infarct size (18.5±2.4% vs. 26.6±1.7%, N=10/group; P=0.01). mRNA and miR profiles pre-MI (N=5/group) identified genes modulated by short-term CR to be associated with circadian clock, oxidative stress, immune function, apoptosis, metabolism, angiogenesis, cytoskeleton and extracellular matrix (ECM). Western blots pre-MI revealed CR-associated increases in phosphorylated Akt and GSK3ß, reduced levels of phosphorylated AMPK and mitochondrial related proteins PGC-1α, cytochrome C and cyclooxygenase (COX) IV, with no differences in the levels of phosphorylated eNOS or MAPK (ERK1/2; p38). CR regimen was also associated with reduced protein abundance of cleaved caspase 3 in the infarcted heart and improved cardiac function.

No MeSH data available.


Related in: MedlinePlus

Short-term CR induces known pro-survival pathways.Western blots analysis of the left ventricular protein extracts after 7 days of caloric restriction depicting significant (A) decrease in AMPK phosphorylation, (B & C) increase in phosphorylation of AKT and its downstream target GSK-3β compared to AL group. Phosphorylation levels of ERK, p38 MAPK and eNOS (D-F) were comparable between the CR and AL mice. Abundance of the mitochondrial proteins PGC-1α, Cytochrome C and COX-IV were significantly reduced in the CR group compared to the AL mice.
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pone.0130658.g007: Short-term CR induces known pro-survival pathways.Western blots analysis of the left ventricular protein extracts after 7 days of caloric restriction depicting significant (A) decrease in AMPK phosphorylation, (B & C) increase in phosphorylation of AKT and its downstream target GSK-3β compared to AL group. Phosphorylation levels of ERK, p38 MAPK and eNOS (D-F) were comparable between the CR and AL mice. Abundance of the mitochondrial proteins PGC-1α, Cytochrome C and COX-IV were significantly reduced in the CR group compared to the AL mice.

Mentions: Next, the phosphorylation (P~) status of signaling pathways previously shown to be involved in cardiac protection such as AMPK [40], Akt/PKB [41], GSK3β [42], ERK and p38 MAPK [43] were examined by Western blot. Densitometry demonstrated a significant increase in P~AKT (pAkt/Akt: AL 0.4±0.1 vs. CR 1.3±0.1, P<0.05; 3.25±0.1 fold change) and its downstream target GSK3β (P~GSK3β/GSK3β: AL 0.4±0.05 vs. CR 0.9±0.1, P<0.05; 2.25±0.1 fold change) (Fig 7A and 7B). By contrast, the phosphorylation status of two members of the MAPK signaling pathway, namely p38 and ERK, were not changed in response to CR (Fig 7C and 7D). We also observed a significant reduction in phosphorylation of the α-subunit of the AMP-activated protein kinase (AMPKα) in CR as compared to AL mice (P~AMPK/AMPK: P AL 1.64±0.3 vs. CR 0.6±0.1, P<0.05; -2.75±0.3 fold) (Fig 7E). By examining down-stream targets of AMPK, such as eNOS and mitochondrial markers, PGC-1, cytochrome c, and COX IV, we found no difference in both total and phosphorylated eNOS levels in the hearts of CR vs. AL mice (Fig 7F), but did find decreased protein abundance of the mitochondrial markers noted above (PGC-1α: AL 1.7±0.3 vs. CR 0.6±0.1; -2.85±0.3 fold change; COX-IV: AL 2.5±0.5 vs. CR 0.9±0.2, -2.85±0.3 fold change; Cytochorome C: AL 5±0.5 vs. CR 3.2±0.1, P<0.05, -1.6±0.1 fold change) (Fig 7G–7I). In addition, protein abundance of autophagic marker LC3B-II were reduced in the hearts of CR mice (AL 0.3±0.02 vs. CR 0.07±0.006, P<0.05, -4.3±0.1 fold change) (Panel A in Fig. A in S2 File). Importantly, sAL mice showed no change in Akt phosphorylation (Panel B in Fig. B in S2 File) indicating that the increased Akt phosphorylation observed following CR is specifically related to the dietary manipulation rather than the stress of animal handling. Together, these results demonstrate that short-term CR modulates known signaling pathways implicated in cardio-protection, mitochondrial function and biogenesis.


Cardioprotective Signature of Short-Term Caloric Restriction.

Noyan H, El-Mounayri O, Isserlin R, Arab S, Momen A, Cheng HS, Wu J, Afroze T, Li RK, Fish JE, Bader GD, Husain M - PLoS ONE (2015)

Short-term CR induces known pro-survival pathways.Western blots analysis of the left ventricular protein extracts after 7 days of caloric restriction depicting significant (A) decrease in AMPK phosphorylation, (B & C) increase in phosphorylation of AKT and its downstream target GSK-3β compared to AL group. Phosphorylation levels of ERK, p38 MAPK and eNOS (D-F) were comparable between the CR and AL mice. Abundance of the mitochondrial proteins PGC-1α, Cytochrome C and COX-IV were significantly reduced in the CR group compared to the AL mice.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4476723&req=5

pone.0130658.g007: Short-term CR induces known pro-survival pathways.Western blots analysis of the left ventricular protein extracts after 7 days of caloric restriction depicting significant (A) decrease in AMPK phosphorylation, (B & C) increase in phosphorylation of AKT and its downstream target GSK-3β compared to AL group. Phosphorylation levels of ERK, p38 MAPK and eNOS (D-F) were comparable between the CR and AL mice. Abundance of the mitochondrial proteins PGC-1α, Cytochrome C and COX-IV were significantly reduced in the CR group compared to the AL mice.
Mentions: Next, the phosphorylation (P~) status of signaling pathways previously shown to be involved in cardiac protection such as AMPK [40], Akt/PKB [41], GSK3β [42], ERK and p38 MAPK [43] were examined by Western blot. Densitometry demonstrated a significant increase in P~AKT (pAkt/Akt: AL 0.4±0.1 vs. CR 1.3±0.1, P<0.05; 3.25±0.1 fold change) and its downstream target GSK3β (P~GSK3β/GSK3β: AL 0.4±0.05 vs. CR 0.9±0.1, P<0.05; 2.25±0.1 fold change) (Fig 7A and 7B). By contrast, the phosphorylation status of two members of the MAPK signaling pathway, namely p38 and ERK, were not changed in response to CR (Fig 7C and 7D). We also observed a significant reduction in phosphorylation of the α-subunit of the AMP-activated protein kinase (AMPKα) in CR as compared to AL mice (P~AMPK/AMPK: P AL 1.64±0.3 vs. CR 0.6±0.1, P<0.05; -2.75±0.3 fold) (Fig 7E). By examining down-stream targets of AMPK, such as eNOS and mitochondrial markers, PGC-1, cytochrome c, and COX IV, we found no difference in both total and phosphorylated eNOS levels in the hearts of CR vs. AL mice (Fig 7F), but did find decreased protein abundance of the mitochondrial markers noted above (PGC-1α: AL 1.7±0.3 vs. CR 0.6±0.1; -2.85±0.3 fold change; COX-IV: AL 2.5±0.5 vs. CR 0.9±0.2, -2.85±0.3 fold change; Cytochorome C: AL 5±0.5 vs. CR 3.2±0.1, P<0.05, -1.6±0.1 fold change) (Fig 7G–7I). In addition, protein abundance of autophagic marker LC3B-II were reduced in the hearts of CR mice (AL 0.3±0.02 vs. CR 0.07±0.006, P<0.05, -4.3±0.1 fold change) (Panel A in Fig. A in S2 File). Importantly, sAL mice showed no change in Akt phosphorylation (Panel B in Fig. B in S2 File) indicating that the increased Akt phosphorylation observed following CR is specifically related to the dietary manipulation rather than the stress of animal handling. Together, these results demonstrate that short-term CR modulates known signaling pathways implicated in cardio-protection, mitochondrial function and biogenesis.

Bottom Line: This short-term model of CR was associated with cardio-protection, as evidenced by decreased infarct size (18.5±2.4% vs. 26.6±1.7%, N=10/group; P=0.01). mRNA and miR profiles pre-MI (N=5/group) identified genes modulated by short-term CR to be associated with circadian clock, oxidative stress, immune function, apoptosis, metabolism, angiogenesis, cytoskeleton and extracellular matrix (ECM).Western blots pre-MI revealed CR-associated increases in phosphorylated Akt and GSK3ß, reduced levels of phosphorylated AMPK and mitochondrial related proteins PGC-1α, cytochrome C and cyclooxygenase (COX) IV, with no differences in the levels of phosphorylated eNOS or MAPK (ERK1/2; p38).CR regimen was also associated with reduced protein abundance of cleaved caspase 3 in the infarcted heart and improved cardiac function.

View Article: PubMed Central - PubMed

Affiliation: Division of Experimental Therapeutics, Toronto General Research Institute, Toronto, Ontario, Canada.

ABSTRACT

Objective: To understand the molecular pathways underlying the cardiac preconditioning effect of short-term caloric restriction (CR).

Background: Lifelong CR has been suggested to reduce the incidence of cardiovascular disease through a variety of mechanisms. However, prolonged adherence to a CR life-style is difficult. Here we reveal the pathways that are modulated by short-term CR, which are associated with protection of the mouse heart from ischemia.

Methods: Male 10-12 wk old C57bl/6 mice were randomly assigned to an ad libitum (AL) diet with free access to regular chow, or CR, receiving 30% less food for 7 days (d), prior to myocardial infarction (MI) via permanent coronary ligation. At d8, the left ventricles (LV) of AL and CR mice were collected for Western blot, mRNA and microRNA (miR) analyses to identify cardioprotective gene expression signatures. In separate groups, infarct size, cardiac hemodynamics and protein abundance of caspase 3 was measured at d2 post-MI.

Results: This short-term model of CR was associated with cardio-protection, as evidenced by decreased infarct size (18.5±2.4% vs. 26.6±1.7%, N=10/group; P=0.01). mRNA and miR profiles pre-MI (N=5/group) identified genes modulated by short-term CR to be associated with circadian clock, oxidative stress, immune function, apoptosis, metabolism, angiogenesis, cytoskeleton and extracellular matrix (ECM). Western blots pre-MI revealed CR-associated increases in phosphorylated Akt and GSK3ß, reduced levels of phosphorylated AMPK and mitochondrial related proteins PGC-1α, cytochrome C and cyclooxygenase (COX) IV, with no differences in the levels of phosphorylated eNOS or MAPK (ERK1/2; p38). CR regimen was also associated with reduced protein abundance of cleaved caspase 3 in the infarcted heart and improved cardiac function.

No MeSH data available.


Related in: MedlinePlus