Assaying sarcoplasmic reticulum Ca^(2+)-leak in mouse atrial myocytes  

作　　者：Fan Xu Jing-Jing Li Eric Yang Yi Zhang Wenjun Xie 

机构地区：[1]School of Life Science and Technology,Xi'an Jiaotong University,Xi'an 710061,China [2]Department of Cardiology,First Affiliated Hospital of Xi'an Jiaotong University,Xi'an 710061,China [3]Department of Physiology and Pathophysiology,School of Basic Medical Sciences,and Key Laboratory of Environment and Genes Related to Diseases,Ministry of Education,Xi'an Jiaotong University Health Science Center,Xi'an 710061,China

出　　处：《Biophysics Reports》2024年第5期297-303,共7页生物物理学报（英文版）

基　　金：supported by grants from the National Natural Science Foundation of China(31971045,32171103)。

摘　　要：More and more studies have suggested an essential role of sarcoplasmic reticulum(SR)Ca^(2+)leak of atrial myocytes in atrial diseases such as atrial fibrillation(AF).The increasing interest in atrial Ca^(2+)signaling makes it necessary to develop a more accurate approach for Ca^(2+)measurement in atrial myocytes due to obvious differences between atrial and ventricular Ca^(2+)handling.In the present study,we proposed a new approach for quantifying total SR Ca^(2+)leak in atrial myocytes with confocal line-scan Ca^(2+)images.With a very precious approximation of the histogram of normalized line-scan Ca^(2+)images by using a modified Gaussian distribution,we separated the signal pixel components from noisy pixels and extracted two new dimensionless parameters,Fsignalsand Rsignals,to reflect the summation of signal pixels and their release components,respectively.In the presence of tetracaine blocking SR Ca^(2+)leak,the two parameters were very close to 0,and in atrial myocytes under normal conditions,the two parameters are well positive correlative with Ca^(2+)spark frequency and total signal mass,the two classic readouts for SR Ca^(2+)leak.Consistent with Ca^(2+)Spark readouts,the two parameters quantified a significant increase of SR Ca^(2+)leak in atrial myocytes from mice harboring a leaky type 2 ryanodine receptor mutation(RyR2-R2474S+/-)compared to the WT group.Collectively,this study proposed a simple and effective approach to quantify SR Ca^(2+)leak in atrial myocytes,which may benefit research on calcium signaling in atrial physiology and diseases.

关 键 词：Atrial myocyte Sarcoplasmic reticulum Ca^(2+)leak Confocal images Ca^(2+)measurement 

分 类 号：R54[医药卫生—心血管疾病]