Epigallocatechin-3-gallate has dual, independent effects on the cardiac sarcoplasmic reticulum/endoplasmic reticulum Ca2+ ATPase

We determined the effects of epigallocatechin-3-gallate (EGCG) and epicatechin (EC), on pump turnover and Ca 2+ transport by the cardiac form of the sarcoplasmic/endoplasmic reticulum Ca 2+ -ATPase (SERCA). Fluorescence spectroscopy was used to directly measure SERCA ATPase activity and to measure C...

Full description

Saved in:
Bibliographic Details
Published in:Journal of muscle research and cell motility 2011-09, Vol.32 (2), p.89-98
Main Authors: Kargacin, M. E., Emmett, T. L., Kargacin, Gary J.
Format: Article
Language:English
Subjects:
Adenosinetriphosphatase
Animal Anatomy
Animals
Antioxidants - pharmacology
Biomedical and Life Sciences
Biomedicine
Ca super(2+)-transporting ATPase
Calcium
Calcium - metabolism
Calcium influx
Calcium transport
Cardiac muscle
Catechin - analogs & derivatives
Catechin - pharmacology
Cell Biology
Cell migration
Dogs
Dose-Response Relationship, Drug
Endoplasmic reticulum
epicatechin
epigallocatechin-3-gallate
fluorescence spectroscopy
Heart
HEK293 Cells
Histology
Humans
Life Sciences
Microsomes
Morphology
Muscles
Myocardium - cytology
Myocardium - metabolism
Myocytes, Cardiac - cytology
Myocytes, Cardiac - metabolism
Original Paper
Phospholamban
Phosphorylation
Proteomics
Sarcoplasmic reticulum
Sarcoplasmic Reticulum - metabolism
Sarcoplasmic Reticulum Calcium-Transporting ATPases - metabolism
Vesicles
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We determined the effects of epigallocatechin-3-gallate (EGCG) and epicatechin (EC), on pump turnover and Ca 2+ transport by the cardiac form of the sarcoplasmic/endoplasmic reticulum Ca 2+ -ATPase (SERCA). Fluorescence spectroscopy was used to directly measure SERCA ATPase activity and to measure Ca 2+ uptake into cardiac sarcoplasmic reticulum (SR) vesicles and microsomes derived from human embryonic kidney (HEK) cells expressing human cardiac SERCA2a. We found that EGCG reduces the maximum velocity of Ca 2+ uptake into cardiac SR vesicles and increases the Ca 2+ -sensitivity of uptake in a concentration-dependent manner. EC is less potent than EGCG in increasing the Ca 2+ -sensitivity of uptake and does not affect maximum uptake velocity. The EGCG-dependent reduction in Ca 2+ uptake velocity is well correlated with direct inhibition of SERCA. The effect of EGCG on the Ca 2+ -sensitivity of Ca 2+ uptake into cardiac SR vesicles is affected by the phosphorylation status of phospholamban (PLB). When cardiac SERCA2a is expressed in HEK cells without PLB, EGCG reduces the maximum velocity of Ca 2+ uptake but does not affect the Ca 2+ -sensitivity of uptake into microsomes derived from these cells indicating that the effect of EGCG on Ca 2+ -sensitivity requires the presence of PLB. Our results show that EGCG has dual effects on SERCA function in cardiac SR vesicles: it directly affects SERCA by reducing maximum uptake velocity; it increases the Ca 2+ -sensitivity of Ca 2+ uptake in a manner that appears to depend on the interaction between SERCA and PLB.
ISSN:0142-4319
1573-2657
DOI:10.1007/s10974-011-9256-7