Altered patterns of gene expression in response to chronic atrial fibrillation.
To obtain greater insight into atrial remodeling at the molecular level we analyzed the changes in gene expression in human atrial tissue between patients with chronic atrial fibrillation (AF) and those with normal sinus rhythm (NSR). cDNA microarray analysis was used to identify genes differentially expressed during sustained AF of more than 6 months (n = 9, mean age, 45 +/- 12, 6 males and 3 females) as compared to those with NSR (n = 9, mean age, 47 +/- 13, 6 males and 3 females). Western blot analysis was performed to confirm the altered gene expression and to establish the changes in protein expression. DNA gel electrophoresis to establish DNA ladder formation, which was associated with apoptosis in response to chronic AF, was performed. Microscopic findings were observed via electron microscopy. In the microarray analysis, out of 8,167 candidate genes, 66 genes showed a significant change in the expression level in the patients with chronic AF, which was in contrast to those with NSR. Among those, 31 genes were consistently down-regulated and 35 up-regulated more than 2-fold. The relative amounts of the Bcl-2 and p27 in the atrial tissue were decreased and angiotensin II type 2 (AT2) receptor and p21 were increased in the patients with chronic AF as compared to those with NSR. The atrial cardiomyocytes in chronic AF showed a prominent DNA ladder, which is a biochemical hallmark of apoptosis. The expression of Bcl-2, AT2 receptor, p21, and p27 were consistent with a significant role in the apoptosis of cardiac myocytes in the patients with chronic AF.
Kim
Nam-Ho
NH
Department of Internal Medicine, Wonkwang University Hospital, Iksan, South Korea.
Ahn
Youngkeun
Y
Oh
Seok Kyu
SK
Cho
Jeong Kwan
JK
Park
Hyung Wook
HW
Kim
Yong-Sook
YS
Hong
Moon Hwa
MH
Nam
Kwang Il
KI
Park
Woo Jin
WJ
Jeong
Myung Ho
MH
Ahn
Byung Hee
BH
Choi
Jong Bum
JB
Kook
Hyun
H
Park
Jong Chun
JC
Jeong
Jin-Won
JW
Kang
Jung Chaee
JC
D000328:Adult; D000368:Aged; D017209:Apoptosis; D001281:Atrial Fibrillation / Q000378:metabolism*; D015153:Blotting, Western; D016022:Case-Control Studies; D018797:Cell Cycle Proteins / Q000378:metabolism*; D050759:Cyclin-Dependent Kinase Inhibitor p21; D050760:Cyclin-Dependent Kinase Inhibitor p27; D015536:Down-Regulation; D004587:Electrophoresis, Agar Gel; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D044139:Receptor, Angiotensin, Type 2 / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D015854:Up-Regulation
C493956:CDKN1A protein, human; D018797:Cell Cycle Proteins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D019253:Proto-Oncogene Proteins c-bcl-2; D044139:Receptor, Angiotensin, Type 2; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27