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Ginkgo biloba extract EGB761 protects against aging-associated diastolic dysfunction in cardiomyocytes of D-galactose-induced aging rat.

Liu J, Wang J, Chen X, Guo C, Guo Y, Wang H - Oxid Med Cell Longev (2012)

Bottom Line: Our results demonstrated that in vitro stimulation with D-galactose induced AGEs production.The addition of EGB761 significantly decreased the number of cells positive for SA-β-gal.Furthermore, decreased diastolic [Ca(2+)](i), curtailment of the time from the maximum concentration of Ca(2+) to the baseline level and increased reuptake of Ca(2+) stores in the SR were also observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Gerontology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.

ABSTRACT
The aim of the present study was to make use of the artificially induced aging model cardiomyocytes to further investigate potential anti-aging-associated cellular diastolic dysfunction effects of EGB761 and explore underlying molecular mechanisms. Cultured rat primary cardiomyocytes were treated with either D-galactose or D-galactose combined with EGB761 for 48 h. After treatment, the percentage of cells positive for SA-β-gal, AGEs production, cardiac sarcoplasmic reticulum calcium pump (SERCA) activity, the myocardial sarcoplasmic reticulum calcium uptake, and relative protein levels were measured. Our results demonstrated that in vitro stimulation with D-galactose induced AGEs production. The addition of EGB761 significantly decreased the number of cells positive for SA-β-gal. Furthermore, decreased diastolic [Ca(2+)](i), curtailment of the time from the maximum concentration of Ca(2+) to the baseline level and increased reuptake of Ca(2+) stores in the SR were also observed. In addition, the level of p-Ser16-PLN protein as well as SERCA was markedly increased. The study indicated that EGb761 alleviates formation of AGEs products on SERCA2a in order to mitigate myocardial stiffness on one hand; on other hand, improve SERCA2a function through increase the amount of Ser16 sites PLN phosphorylation, which two hands finally led to ameliorate diastolic dysfunction of aging cardiomyocytes.

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Effect of EGB761 on SERCA2a, Ser16-phosphorylated PLN (p-Ser16 PLN), Thr17-phosphorylated PLN (p-Thr17 PLN) protein levels. Representative immunoblots for SERCA2a: p-Ser16 PLN, p-Thr17 PLN, and GAPDH in samples obtained from the control (lane 1), D-galactose (lane2), D-galactose + EGB761 (lane 3). Summarized data showing SERCA2a, p-Ser16 PLN, and p-Thr17 PLN protein expression normalized. Values are expressed as mean ± SD (n = 4, aP < 0.05 versus control group; bP < 0.05 versus D-galactose group).
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fig2: Effect of EGB761 on SERCA2a, Ser16-phosphorylated PLN (p-Ser16 PLN), Thr17-phosphorylated PLN (p-Thr17 PLN) protein levels. Representative immunoblots for SERCA2a: p-Ser16 PLN, p-Thr17 PLN, and GAPDH in samples obtained from the control (lane 1), D-galactose (lane2), D-galactose + EGB761 (lane 3). Summarized data showing SERCA2a, p-Ser16 PLN, and p-Thr17 PLN protein expression normalized. Values are expressed as mean ± SD (n = 4, aP < 0.05 versus control group; bP < 0.05 versus D-galactose group).

Mentions: In order to investigate the underlying mechanisms of EGB761 protecting against aging-associated diastolic dysfunction in cardiomyocytes, protein levels of calcium transport regulatory proteins were measured by Western blot. As shown in Figure 2, an approximately 60% downregulation of SERCA2a protein expression was observed in D-galactose-treated cardiomyocytes, while it was increased in addition of EGB761 compared with the D-galactose group (P < 0.05). Since the inhibitory effect of PLN on SERCA2a was dependent on the phosphorylation level of PLN, p- Ser16-PLN and p-Thr17-PLN protein expressions were then measured. As shown in Figure 2, the level of p-Ser16-PLN protein expression was markedly decreased by 54% in the D-galactose-treated cardiomyocytes compared with the control group, while it was increased in the EGB761 group (P < 0.05 versus D-galactose). However, the level of p-Thr17-PLN protein expression showed no significant changes in any groups (n = 20 number of rats and n = 6 experimental replicates; P < 0.05 versus D-galactose).


Ginkgo biloba extract EGB761 protects against aging-associated diastolic dysfunction in cardiomyocytes of D-galactose-induced aging rat.

Liu J, Wang J, Chen X, Guo C, Guo Y, Wang H - Oxid Med Cell Longev (2012)

Effect of EGB761 on SERCA2a, Ser16-phosphorylated PLN (p-Ser16 PLN), Thr17-phosphorylated PLN (p-Thr17 PLN) protein levels. Representative immunoblots for SERCA2a: p-Ser16 PLN, p-Thr17 PLN, and GAPDH in samples obtained from the control (lane 1), D-galactose (lane2), D-galactose + EGB761 (lane 3). Summarized data showing SERCA2a, p-Ser16 PLN, and p-Thr17 PLN protein expression normalized. Values are expressed as mean ± SD (n = 4, aP < 0.05 versus control group; bP < 0.05 versus D-galactose group).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3368694&req=5

fig2: Effect of EGB761 on SERCA2a, Ser16-phosphorylated PLN (p-Ser16 PLN), Thr17-phosphorylated PLN (p-Thr17 PLN) protein levels. Representative immunoblots for SERCA2a: p-Ser16 PLN, p-Thr17 PLN, and GAPDH in samples obtained from the control (lane 1), D-galactose (lane2), D-galactose + EGB761 (lane 3). Summarized data showing SERCA2a, p-Ser16 PLN, and p-Thr17 PLN protein expression normalized. Values are expressed as mean ± SD (n = 4, aP < 0.05 versus control group; bP < 0.05 versus D-galactose group).
Mentions: In order to investigate the underlying mechanisms of EGB761 protecting against aging-associated diastolic dysfunction in cardiomyocytes, protein levels of calcium transport regulatory proteins were measured by Western blot. As shown in Figure 2, an approximately 60% downregulation of SERCA2a protein expression was observed in D-galactose-treated cardiomyocytes, while it was increased in addition of EGB761 compared with the D-galactose group (P < 0.05). Since the inhibitory effect of PLN on SERCA2a was dependent on the phosphorylation level of PLN, p- Ser16-PLN and p-Thr17-PLN protein expressions were then measured. As shown in Figure 2, the level of p-Ser16-PLN protein expression was markedly decreased by 54% in the D-galactose-treated cardiomyocytes compared with the control group, while it was increased in the EGB761 group (P < 0.05 versus D-galactose). However, the level of p-Thr17-PLN protein expression showed no significant changes in any groups (n = 20 number of rats and n = 6 experimental replicates; P < 0.05 versus D-galactose).

Bottom Line: Our results demonstrated that in vitro stimulation with D-galactose induced AGEs production.The addition of EGB761 significantly decreased the number of cells positive for SA-β-gal.Furthermore, decreased diastolic [Ca(2+)](i), curtailment of the time from the maximum concentration of Ca(2+) to the baseline level and increased reuptake of Ca(2+) stores in the SR were also observed.

View Article: PubMed Central - PubMed

Affiliation: Department of Gerontology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.

ABSTRACT
The aim of the present study was to make use of the artificially induced aging model cardiomyocytes to further investigate potential anti-aging-associated cellular diastolic dysfunction effects of EGB761 and explore underlying molecular mechanisms. Cultured rat primary cardiomyocytes were treated with either D-galactose or D-galactose combined with EGB761 for 48 h. After treatment, the percentage of cells positive for SA-β-gal, AGEs production, cardiac sarcoplasmic reticulum calcium pump (SERCA) activity, the myocardial sarcoplasmic reticulum calcium uptake, and relative protein levels were measured. Our results demonstrated that in vitro stimulation with D-galactose induced AGEs production. The addition of EGB761 significantly decreased the number of cells positive for SA-β-gal. Furthermore, decreased diastolic [Ca(2+)](i), curtailment of the time from the maximum concentration of Ca(2+) to the baseline level and increased reuptake of Ca(2+) stores in the SR were also observed. In addition, the level of p-Ser16-PLN protein as well as SERCA was markedly increased. The study indicated that EGb761 alleviates formation of AGEs products on SERCA2a in order to mitigate myocardial stiffness on one hand; on other hand, improve SERCA2a function through increase the amount of Ser16 sites PLN phosphorylation, which two hands finally led to ameliorate diastolic dysfunction of aging cardiomyocytes.

Show MeSH
Related in: MedlinePlus