TY - JOUR
T1 - Activation of histone deacetylase-6 induces contractile dysfunction through derailment of α-tubulin proteostasis in experimental and human atrial fibrillation
AU - Zhang, Deli
AU - Wu, Chia-Tung
AU - Qi, XiaoYan
AU - Meijering, Roelien A M
AU - Hoogstra-Berends, Femke
AU - Tadevosyan, Artavazd
AU - Cubukcuoglu Deniz, Gunseli
AU - Durdu, Serkan
AU - Akar, Ahmet Ruchan
AU - Sibon, Ody C M
AU - Nattel, Stanley
AU - Henning, Robert H
AU - Brundel, Bianca J J M
PY - 2014/1/21
Y1 - 2014/1/21
N2 - BACKGROUND: Atrial fibrillation (AF) is characterized by structural remodeling, contractile dysfunction, and AF progression. Histone deacetylases (HDACs) influence acetylation of both histones and cytosolic proteins, thereby mediating epigenetic regulation and influencing cell proteostasis. Because the exact function of HDACs in AF is unknown, we investigated their role in experimental and clinical AF models.METHODS AND RESULTS: Tachypacing of HL-1 atrial cardiomyocytes and Drosophila pupae hearts significantly impaired contractile function (amplitude of Ca(2+) transients and heart wall contractions). This dysfunction was prevented by inhibition of HDAC6 (tubacin) and sirtuins (nicotinamide). Tachypacing induced specific activation of HDAC6, resulting in α-tubulin deacetylation, depolymerization, and degradation by calpain. Tachypacing-induced contractile dysfunction was completely rescued by dominant-negative HDAC6 mutants with loss of deacetylase activity in the second catalytic domain, which bears α-tubulin deacetylase activity. Furthermore, in vivo treatment with the HDAC6 inhibitor tubastatin A protected atrial tachypaced dogs from electric remodeling (action potential duration shortening, L-type Ca(2+) current reduction, AF promotion) and cellular Ca(2+)-handling/contractile dysfunction (loss of Ca(2+) transient amplitude, sarcomere contractility). Finally, atrial tissue from patients with AF also showed a significant increase in HDAC6 activity and reduction in the expression of both acetylated and total α-tubulin.CONCLUSIONS: AF induces remodeling and loss of contractile function, at least in part through HDAC6 activation and subsequent derailment of α-tubulin proteostasis and disruption of the cardiomyocyte microtubule structure. In vivo inhibition of HDAC6 protects against AF-related atrial remodeling, disclosing the potential of HDAC6 as a therapeutic target in clinical AF.
AB - BACKGROUND: Atrial fibrillation (AF) is characterized by structural remodeling, contractile dysfunction, and AF progression. Histone deacetylases (HDACs) influence acetylation of both histones and cytosolic proteins, thereby mediating epigenetic regulation and influencing cell proteostasis. Because the exact function of HDACs in AF is unknown, we investigated their role in experimental and clinical AF models.METHODS AND RESULTS: Tachypacing of HL-1 atrial cardiomyocytes and Drosophila pupae hearts significantly impaired contractile function (amplitude of Ca(2+) transients and heart wall contractions). This dysfunction was prevented by inhibition of HDAC6 (tubacin) and sirtuins (nicotinamide). Tachypacing induced specific activation of HDAC6, resulting in α-tubulin deacetylation, depolymerization, and degradation by calpain. Tachypacing-induced contractile dysfunction was completely rescued by dominant-negative HDAC6 mutants with loss of deacetylase activity in the second catalytic domain, which bears α-tubulin deacetylase activity. Furthermore, in vivo treatment with the HDAC6 inhibitor tubastatin A protected atrial tachypaced dogs from electric remodeling (action potential duration shortening, L-type Ca(2+) current reduction, AF promotion) and cellular Ca(2+)-handling/contractile dysfunction (loss of Ca(2+) transient amplitude, sarcomere contractility). Finally, atrial tissue from patients with AF also showed a significant increase in HDAC6 activity and reduction in the expression of both acetylated and total α-tubulin.CONCLUSIONS: AF induces remodeling and loss of contractile function, at least in part through HDAC6 activation and subsequent derailment of α-tubulin proteostasis and disruption of the cardiomyocyte microtubule structure. In vivo inhibition of HDAC6 protects against AF-related atrial remodeling, disclosing the potential of HDAC6 as a therapeutic target in clinical AF.
KW - Acetylation
KW - Animals
KW - Atrial Fibrillation/metabolism
KW - Atrial Remodeling/physiology
KW - Calpain/metabolism
KW - Cardiac Pacing, Artificial
KW - Dogs
KW - Drosophila
KW - Drosophila Proteins/antagonists & inhibitors
KW - HeLa Cells
KW - Histone Deacetylase 6
KW - Histone Deacetylases/metabolism
KW - Humans
KW - Hydroxamic Acids/pharmacology
KW - Indoles/pharmacology
KW - Mice
KW - Microtubules/metabolism
KW - Myocardial Contraction/physiology
KW - Myocytes, Cardiac/cytology
KW - Tubulin/metabolism
U2 - 10.1161/CIRCULATIONAHA.113.005300
DO - 10.1161/CIRCULATIONAHA.113.005300
M3 - Article
C2 - 24146251
VL - 129
SP - 346
EP - 358
JO - Circulation
JF - Circulation
SN - 0009-7322
IS - 3
ER -