TY - JOUR
T1 - Direct measurement of Ca2+ concentration in the SR of living cardiac myocytes
AU - Kasai, Hiroki
AU - Yao, Atsushi
AU - Oyama, Tomomi
AU - Hasegawa, Hiroshi
AU - Akazawa, Hiroshi
AU - Toko, Haruhiro
AU - Nagai, Toshio
AU - Kinugawa, Koichiro
AU - Kohmoto, Osami
AU - Maruyama, Kei
AU - Takahashi, Toshiyuki
AU - Nagai, Ryozo
AU - Miyawaki, Atsushi
AU - Komuro, Issei
N1 - Funding Information:
This work was partly supported by a Grant-in-Aid for Scientific Research on Priority Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan, Japan Heart Foundation, Takeda Medical Research Foundation, Uehara Memorial Foundation, and Grant-in-Aid of Japan Medical Association, The Kato Memorial Trust for Nambyo Research, and Takeda Science Foundation. We thank Dr. Makoto Endo and Dr. William. H. Barry for their kind suggestions on the experimental protocols and the results in this study.
PY - 2004/2/20
Y1 - 2004/2/20
N2 - Although abnormal sarcoplasmic reticulum (SR) Ca2+ handling may cause heart failure, there has been no method to directly measure Ca 2+ concentration in SR ([Ca2+]SR) of living cardiomyocytes. We have measured [Ca2+]SR by expressing novel fluorescent Ca2+ indicators yellow cameleon (YC) 2.1, YC3er, and YC4er in cultured neonatal rat cardiomyocytes. The distribution of YC2.1 was uniform in the cytoplasm, while that of YC3er/YC4er, containing the signal sequence which recruits them to SR, showed reticular pattern and was co-localized with SERCA2a. The treatment with caffeine reversibly decreased the emission ratio (R) in YC3er/YC4er-expressing myocytes, and the treatment with ryanodine and thapsigargin decreased R irreversibly. During the contraction-relaxation cycle, R was changed periodically in the YC2.1- and YC3er-expressing myocytes, but its direction of the change was opposite. These results suggest that YC3er/YC4er were specifically localized and functioned in SR as a [Ca2+]SR indicator. This technique would be useful to understand the function of SR in failing myocardium.
AB - Although abnormal sarcoplasmic reticulum (SR) Ca2+ handling may cause heart failure, there has been no method to directly measure Ca 2+ concentration in SR ([Ca2+]SR) of living cardiomyocytes. We have measured [Ca2+]SR by expressing novel fluorescent Ca2+ indicators yellow cameleon (YC) 2.1, YC3er, and YC4er in cultured neonatal rat cardiomyocytes. The distribution of YC2.1 was uniform in the cytoplasm, while that of YC3er/YC4er, containing the signal sequence which recruits them to SR, showed reticular pattern and was co-localized with SERCA2a. The treatment with caffeine reversibly decreased the emission ratio (R) in YC3er/YC4er-expressing myocytes, and the treatment with ryanodine and thapsigargin decreased R irreversibly. During the contraction-relaxation cycle, R was changed periodically in the YC2.1- and YC3er-expressing myocytes, but its direction of the change was opposite. These results suggest that YC3er/YC4er were specifically localized and functioned in SR as a [Ca2+]SR indicator. This technique would be useful to understand the function of SR in failing myocardium.
KW - Caffeine
KW - Cardiomyocyte
KW - Fluorescent Ca indicators
KW - Heart failure
KW - Real-time monitoring
KW - SERCA
KW - Sarcoplasmic reticulum
KW - Thapsigargin
KW - Yellow cameleon
UR - http://www.scopus.com/inward/record.url?scp=0942300663&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2003.12.189
DO - 10.1016/j.bbrc.2003.12.189
M3 - 学術論文
C2 - 14751234
AN - SCOPUS:0942300663
SN - 0006-291X
VL - 314
SP - 1014
EP - 1020
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 4
ER -