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A soluble receptor for advanced glycation end-products inhibits hypoxia/reoxygenation-induced apoptosis in rat cardiomyocytes via the mitochondrial pathway.

Guo C, Zeng X, Song J, Zhang M, Wang H, Xu X, Du F, Chen B - Int J Mol Sci (2012)

Bottom Line: Compared with H/R alone, sRAGE pretreatment reduced H/R-induced cardiomyocyte apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (p < 0.05).In addition, sRAGE treatment significantly inhibited H/R-induced mitochondrial depolarization and mPTP opening, reduced mitochondrial cytochrome c leakage, caspase-3 and caspase-9 activity, and decreased the ratio of Bax to Bcl-2.Therefore, we conclude that the exogenous administration of sRAGE during H/R is involved in cardioprotection by inhibiting apoptosis via the mitochondrial pathway, which, if further confirmed in vivo, may have important clinical implications during H/R.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Beijing Tian Tan Hospital, Capital Medical University, Beijing 100050, China; E-Mails: songjuan2008@163.com (J.S.); dayanjingzm@sina.com (M.Z.); xuxiaoweittyy@sina.com (X.X.); fhduu@yahoo.com.cn (F.D.); chbux@126.com (B.C.).

ABSTRACT
Severe myocardial dysfunction and tissue damage resulting from ischemia/reperfusion (I/R) is a common clinical scenario in patients with certain types of heart diseases and therapies such as thrombolysis, percutaneous coronary intervention, coronary artery bypass grafting, and cardiac transplantation. The underlining mechanism of endogenous cardiac protection after I/R injury has been a focus of current research. Growing evidences suggests that soluble receptor for advanced glycation end-products (sRAGE) has a cardioprotective effect; however, its role in I/R injury remains unclear. We hypothesized that exogenous administration of sRAGE during hypoxia/reoxygenation (H/R) induces cardioprotection by inhibiting cardiomyocyte apoptosis via multiple signals, involving mitochondrial membrane potential (MMP), the mitochondrial permeability transition pore (mPTP), mitochondrial cytochrome c, caspase-3, Bcl-2 and Bax. Neonatal rat cardiomyocytes underwent hypoxia for 3-h followed by 2-h reoxygenation or were treated with sRAGE for 10 min before H/R. Compared with H/R alone, sRAGE pretreatment reduced H/R-induced cardiomyocyte apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (p < 0.05). In addition, sRAGE treatment significantly inhibited H/R-induced mitochondrial depolarization and mPTP opening, reduced mitochondrial cytochrome c leakage, caspase-3 and caspase-9 activity, and decreased the ratio of Bax to Bcl-2. Therefore, we conclude that the exogenous administration of sRAGE during H/R is involved in cardioprotection by inhibiting apoptosis via the mitochondrial pathway, which, if further confirmed in vivo, may have important clinical implications during H/R.

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Effect of sRAGE on apoptosis. Effect of sRAGE during H/R on apoptosis by Hoechst 33258 (A) and TUNEL staining (B). Con, no treatment; Con-sRAGE, sRAGE alone; H/R, 3-h hypoxia followed by 2-h reoxygenation; H/R-sRAGE, sRAGE for 10 min, then 3-h hypoxia before 2-h reoxygenation. The scale bar indicates 50 μM. Apoptotic ratio further analyzed by Hoechst 33258 staining (C) and TUNEL staining (D). Dose of sRAGE was 900 ng/mL. Data are the mean ± SD (* p < 0.01 compared with the control, # p < 0.01 compared with H/R).
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f3-ijms-13-11923: Effect of sRAGE on apoptosis. Effect of sRAGE during H/R on apoptosis by Hoechst 33258 (A) and TUNEL staining (B). Con, no treatment; Con-sRAGE, sRAGE alone; H/R, 3-h hypoxia followed by 2-h reoxygenation; H/R-sRAGE, sRAGE for 10 min, then 3-h hypoxia before 2-h reoxygenation. The scale bar indicates 50 μM. Apoptotic ratio further analyzed by Hoechst 33258 staining (C) and TUNEL staining (D). Dose of sRAGE was 900 ng/mL. Data are the mean ± SD (* p < 0.01 compared with the control, # p < 0.01 compared with H/R).

Mentions: To determine the effect of sRAGE pretreatment on apoptosis induced by H/R in cultures of neonatal rat cardiac myocytes, we first examined cell morphology by phase-contrast microscopy and nuclear morphology by Hoechst and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. Hoechst 33258 staining revealed that control cell nuclei had regular contours and round or elliptical shapes. In contrast, H/R cells showed smaller nuclei and condensed chromatin. Incubation with sRAGE improved morphological features and decreased the number of apoptotic cells induced by H/R. (Figure 3A). The apoptosis ratio was higher for H/R as compared to the control (27.9% ± 5.9% vs. 11.4% ± 2.4%, respectively; n = 8, p < 0.01). Compared with the H/R treatment, sRAGE pre-treatment decreased H/R-induced apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (n = 8, p < 0.01). sRAGE alone had no effect on cardiomyocyte apoptosis (Figure 3B). The apoptotic results were further confirmed by TUNEL staining (Figure 3C). Almost no TUNEL-positive cells could be found with control treatment, but many TUNEL-positive cells were found with H/R. The number of TUNEL-positive cells was higher for H/R as compared to the control (30.4% ± 5.2% vs. 9.2% ± 2.0%, respectively; n = 8, p < 0.01). Compared with the H/R treatment, sRAGE pre-treatment decreased H/R-induced apoptosis from 30.4% ± 5.2% to 14.5% ± 3.3% (n = 8, p < 0.01). sRAGE alone had no effect on cardiomyocyte apoptosis (Figure 3D).


A soluble receptor for advanced glycation end-products inhibits hypoxia/reoxygenation-induced apoptosis in rat cardiomyocytes via the mitochondrial pathway.

Guo C, Zeng X, Song J, Zhang M, Wang H, Xu X, Du F, Chen B - Int J Mol Sci (2012)

Effect of sRAGE on apoptosis. Effect of sRAGE during H/R on apoptosis by Hoechst 33258 (A) and TUNEL staining (B). Con, no treatment; Con-sRAGE, sRAGE alone; H/R, 3-h hypoxia followed by 2-h reoxygenation; H/R-sRAGE, sRAGE for 10 min, then 3-h hypoxia before 2-h reoxygenation. The scale bar indicates 50 μM. Apoptotic ratio further analyzed by Hoechst 33258 staining (C) and TUNEL staining (D). Dose of sRAGE was 900 ng/mL. Data are the mean ± SD (* p < 0.01 compared with the control, # p < 0.01 compared with H/R).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472784&req=5

f3-ijms-13-11923: Effect of sRAGE on apoptosis. Effect of sRAGE during H/R on apoptosis by Hoechst 33258 (A) and TUNEL staining (B). Con, no treatment; Con-sRAGE, sRAGE alone; H/R, 3-h hypoxia followed by 2-h reoxygenation; H/R-sRAGE, sRAGE for 10 min, then 3-h hypoxia before 2-h reoxygenation. The scale bar indicates 50 μM. Apoptotic ratio further analyzed by Hoechst 33258 staining (C) and TUNEL staining (D). Dose of sRAGE was 900 ng/mL. Data are the mean ± SD (* p < 0.01 compared with the control, # p < 0.01 compared with H/R).
Mentions: To determine the effect of sRAGE pretreatment on apoptosis induced by H/R in cultures of neonatal rat cardiac myocytes, we first examined cell morphology by phase-contrast microscopy and nuclear morphology by Hoechst and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining. Hoechst 33258 staining revealed that control cell nuclei had regular contours and round or elliptical shapes. In contrast, H/R cells showed smaller nuclei and condensed chromatin. Incubation with sRAGE improved morphological features and decreased the number of apoptotic cells induced by H/R. (Figure 3A). The apoptosis ratio was higher for H/R as compared to the control (27.9% ± 5.9% vs. 11.4% ± 2.4%, respectively; n = 8, p < 0.01). Compared with the H/R treatment, sRAGE pre-treatment decreased H/R-induced apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (n = 8, p < 0.01). sRAGE alone had no effect on cardiomyocyte apoptosis (Figure 3B). The apoptotic results were further confirmed by TUNEL staining (Figure 3C). Almost no TUNEL-positive cells could be found with control treatment, but many TUNEL-positive cells were found with H/R. The number of TUNEL-positive cells was higher for H/R as compared to the control (30.4% ± 5.2% vs. 9.2% ± 2.0%, respectively; n = 8, p < 0.01). Compared with the H/R treatment, sRAGE pre-treatment decreased H/R-induced apoptosis from 30.4% ± 5.2% to 14.5% ± 3.3% (n = 8, p < 0.01). sRAGE alone had no effect on cardiomyocyte apoptosis (Figure 3D).

Bottom Line: Compared with H/R alone, sRAGE pretreatment reduced H/R-induced cardiomyocyte apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (p < 0.05).In addition, sRAGE treatment significantly inhibited H/R-induced mitochondrial depolarization and mPTP opening, reduced mitochondrial cytochrome c leakage, caspase-3 and caspase-9 activity, and decreased the ratio of Bax to Bcl-2.Therefore, we conclude that the exogenous administration of sRAGE during H/R is involved in cardioprotection by inhibiting apoptosis via the mitochondrial pathway, which, if further confirmed in vivo, may have important clinical implications during H/R.

View Article: PubMed Central - PubMed

Affiliation: Department of Cardiology, Beijing Tian Tan Hospital, Capital Medical University, Beijing 100050, China; E-Mails: songjuan2008@163.com (J.S.); dayanjingzm@sina.com (M.Z.); xuxiaoweittyy@sina.com (X.X.); fhduu@yahoo.com.cn (F.D.); chbux@126.com (B.C.).

ABSTRACT
Severe myocardial dysfunction and tissue damage resulting from ischemia/reperfusion (I/R) is a common clinical scenario in patients with certain types of heart diseases and therapies such as thrombolysis, percutaneous coronary intervention, coronary artery bypass grafting, and cardiac transplantation. The underlining mechanism of endogenous cardiac protection after I/R injury has been a focus of current research. Growing evidences suggests that soluble receptor for advanced glycation end-products (sRAGE) has a cardioprotective effect; however, its role in I/R injury remains unclear. We hypothesized that exogenous administration of sRAGE during hypoxia/reoxygenation (H/R) induces cardioprotection by inhibiting cardiomyocyte apoptosis via multiple signals, involving mitochondrial membrane potential (MMP), the mitochondrial permeability transition pore (mPTP), mitochondrial cytochrome c, caspase-3, Bcl-2 and Bax. Neonatal rat cardiomyocytes underwent hypoxia for 3-h followed by 2-h reoxygenation or were treated with sRAGE for 10 min before H/R. Compared with H/R alone, sRAGE pretreatment reduced H/R-induced cardiomyocyte apoptosis from 27.9% ± 5.9% to 9.4% ± 0.7% (p < 0.05). In addition, sRAGE treatment significantly inhibited H/R-induced mitochondrial depolarization and mPTP opening, reduced mitochondrial cytochrome c leakage, caspase-3 and caspase-9 activity, and decreased the ratio of Bax to Bcl-2. Therefore, we conclude that the exogenous administration of sRAGE during H/R is involved in cardioprotection by inhibiting apoptosis via the mitochondrial pathway, which, if further confirmed in vivo, may have important clinical implications during H/R.

Show MeSH
Related in: MedlinePlus