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Catestatin attenuates endoplasmic reticulum induced cell apoptosis by activation type 2 muscarinic acetylcholine receptor in cardiac ischemia/reperfusion.

Liao F, Zheng Y, Cai J, Fan J, Wang J, Yang J, Cui Q, Xu G, Tang C, Geng B - Sci Rep (2015)

Bottom Line: Cardiomyocytes endogenously produced CST and its expression was reduced after I/R.CST pretreatment decreased apoptosis especially endoplasmic reticulum (ER) stress response during I/R.The protective effects of CST were blocked by extracellular signal-regulated kinases 1/2 (ERK1/2) inhibitor PD90895 and phosphoinositide 3-kinase (PI3 K) inhibitor wortmannin.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology and Pathophysiology, School of Basic Medical Science, Peking University, P.R. China.

ABSTRACT
Catestatin (CST) is a catecholamine secretion inhibiting peptide as non-competitive inhibitor of nicotinic acetylcholine receptor. CST play a protective role in cardiac ischemia/reperfusion (I/R) but the molecular mechanism remains unclear. Cardiomyocytes endogenously produced CST and its expression was reduced after I/R. CST pretreatment decreased apoptosis especially endoplasmic reticulum (ER) stress response during I/R. The protection of CST was confirmed in H9c2 cardiomyoblasts under Anoxia/reoxygenation (A/R). In contrast, siRNA-mediated knockdown of CST exaggerated ER stress induced apoptosis. The protective effects of CST were blocked by extracellular signal-regulated kinases 1/2 (ERK1/2) inhibitor PD90895 and phosphoinositide 3-kinase (PI3 K) inhibitor wortmannin. CST also increased ERK1/2 and protein kinase B (Akt) phosphorylation and which was blocked by atropine and selective type 2 muscarinic acetylcholine (M2) receptor, but not type 1 muscarinic acetylcholine (M1) receptor antagonist. Receptor binding assay revealed that CST competitively bound to the M2 receptor with a 50% inhibitory concentration of 25.7 nM. Accordingly, CST inhibited cellular cAMP stimulated by isoproterenol or forskolin, and which was blocked by selective M2 receptor antagonist. Our findings revealed that CST binds to M2 receptor, then activates ERK1/2 and PI3 K/Akt pathway to inhibit ER stress-induced cell apoptosis resulting in attenuation cardiac I/R injury.

No MeSH data available.


Related in: MedlinePlus

CST protected against ER-stress induced apoptosis via ERK1/2 and PI3 K pathway in H9c2 cardiomyoblast.Western blot analysis of protein expression of ER stress-marker proteins and apoptosis cell number with treatment with stress inducers dithiothreitol (DTT) (a), tunicamycin (b), and thapsigargin (c) after pretreatment with PD98059 or wortmannin. **P < 0.01 vs single ER-stress inducers, #P < 0.05 vs single catestatin treatment. Eight independent experiments were performed for above studies.
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f5: CST protected against ER-stress induced apoptosis via ERK1/2 and PI3 K pathway in H9c2 cardiomyoblast.Western blot analysis of protein expression of ER stress-marker proteins and apoptosis cell number with treatment with stress inducers dithiothreitol (DTT) (a), tunicamycin (b), and thapsigargin (c) after pretreatment with PD98059 or wortmannin. **P < 0.01 vs single ER-stress inducers, #P < 0.05 vs single catestatin treatment. Eight independent experiments were performed for above studies.

Mentions: To confirm these pathways involved in ER stress-induced cellular apoptosis by CST, we measured the effect of these inhibitors on DTT-, tunicamycin- and thapsigargin-induced cellular apoptosis. In situ staining of apoptotic cells with cleaved caspase-3 antibody revealed that CST reduced the number of apoptotic cells induced by DTT, tunicamycin and thapsigargin, and which also were blocked by PD98059 and wortmannin (see supplementary Fig. S7–S9 online). Consistently, the major apoptosis pathway of ER stress—Chop expression, caspase-12 cleavage and JNK phosphorylation, ER stress response markers including phosphorylated PERK, Grp78 protein expression—were also lowered by CP while inducing by DTT (Fig. 5a, and supplementary Fig. S10 online), tunicamycin (Fig. 5b and supplementary Fig. S11 online) and thapsigargin (Fig. 5c and supplementary Fig. S12 online), which were also reversed by two inhibitors. Therefore, CST inhibited apoptotic pathways of the unfolded protein response in part via ERK and PI3 K signaling pathways.


Catestatin attenuates endoplasmic reticulum induced cell apoptosis by activation type 2 muscarinic acetylcholine receptor in cardiac ischemia/reperfusion.

Liao F, Zheng Y, Cai J, Fan J, Wang J, Yang J, Cui Q, Xu G, Tang C, Geng B - Sci Rep (2015)

CST protected against ER-stress induced apoptosis via ERK1/2 and PI3 K pathway in H9c2 cardiomyoblast.Western blot analysis of protein expression of ER stress-marker proteins and apoptosis cell number with treatment with stress inducers dithiothreitol (DTT) (a), tunicamycin (b), and thapsigargin (c) after pretreatment with PD98059 or wortmannin. **P < 0.01 vs single ER-stress inducers, #P < 0.05 vs single catestatin treatment. Eight independent experiments were performed for above studies.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4645123&req=5

f5: CST protected against ER-stress induced apoptosis via ERK1/2 and PI3 K pathway in H9c2 cardiomyoblast.Western blot analysis of protein expression of ER stress-marker proteins and apoptosis cell number with treatment with stress inducers dithiothreitol (DTT) (a), tunicamycin (b), and thapsigargin (c) after pretreatment with PD98059 or wortmannin. **P < 0.01 vs single ER-stress inducers, #P < 0.05 vs single catestatin treatment. Eight independent experiments were performed for above studies.
Mentions: To confirm these pathways involved in ER stress-induced cellular apoptosis by CST, we measured the effect of these inhibitors on DTT-, tunicamycin- and thapsigargin-induced cellular apoptosis. In situ staining of apoptotic cells with cleaved caspase-3 antibody revealed that CST reduced the number of apoptotic cells induced by DTT, tunicamycin and thapsigargin, and which also were blocked by PD98059 and wortmannin (see supplementary Fig. S7–S9 online). Consistently, the major apoptosis pathway of ER stress—Chop expression, caspase-12 cleavage and JNK phosphorylation, ER stress response markers including phosphorylated PERK, Grp78 protein expression—were also lowered by CP while inducing by DTT (Fig. 5a, and supplementary Fig. S10 online), tunicamycin (Fig. 5b and supplementary Fig. S11 online) and thapsigargin (Fig. 5c and supplementary Fig. S12 online), which were also reversed by two inhibitors. Therefore, CST inhibited apoptotic pathways of the unfolded protein response in part via ERK and PI3 K signaling pathways.

Bottom Line: Cardiomyocytes endogenously produced CST and its expression was reduced after I/R.CST pretreatment decreased apoptosis especially endoplasmic reticulum (ER) stress response during I/R.The protective effects of CST were blocked by extracellular signal-regulated kinases 1/2 (ERK1/2) inhibitor PD90895 and phosphoinositide 3-kinase (PI3 K) inhibitor wortmannin.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology and Pathophysiology, School of Basic Medical Science, Peking University, P.R. China.

ABSTRACT
Catestatin (CST) is a catecholamine secretion inhibiting peptide as non-competitive inhibitor of nicotinic acetylcholine receptor. CST play a protective role in cardiac ischemia/reperfusion (I/R) but the molecular mechanism remains unclear. Cardiomyocytes endogenously produced CST and its expression was reduced after I/R. CST pretreatment decreased apoptosis especially endoplasmic reticulum (ER) stress response during I/R. The protection of CST was confirmed in H9c2 cardiomyoblasts under Anoxia/reoxygenation (A/R). In contrast, siRNA-mediated knockdown of CST exaggerated ER stress induced apoptosis. The protective effects of CST were blocked by extracellular signal-regulated kinases 1/2 (ERK1/2) inhibitor PD90895 and phosphoinositide 3-kinase (PI3 K) inhibitor wortmannin. CST also increased ERK1/2 and protein kinase B (Akt) phosphorylation and which was blocked by atropine and selective type 2 muscarinic acetylcholine (M2) receptor, but not type 1 muscarinic acetylcholine (M1) receptor antagonist. Receptor binding assay revealed that CST competitively bound to the M2 receptor with a 50% inhibitory concentration of 25.7 nM. Accordingly, CST inhibited cellular cAMP stimulated by isoproterenol or forskolin, and which was blocked by selective M2 receptor antagonist. Our findings revealed that CST binds to M2 receptor, then activates ERK1/2 and PI3 K/Akt pathway to inhibit ER stress-induced cell apoptosis resulting in attenuation cardiac I/R injury.

No MeSH data available.


Related in: MedlinePlus