Effect of angiotensin II receptor 1 antisense oligodoexynucleotides on physiological and pathophysiological growth of cardiomyocytes.
OBJECTIVE
To evaluate the role of angiotensin II receptor 1 antisense oligodexynucleotides (AT1R-AS-ODNs) on physiological and pathophysiological growth of cardiomyocytes from normotensive rats.


METHODS
Cardiomyocytes were transfected with AT1R-AS-ODNs (200 nmol/L) followed by treatment with or without angiotensin II (1 micromol/L). In situ hybridization and Western blot were used for AT1R mRNA and protein detection, respectively. c-Jun N-terminal protein kinase (JNK) activity was characterized by immune complex kinase assay. c-Jun protein expression was examined by immunocytochemistry. DNA content was detected by flow cytometric assay. Atrial natriuretic factor (ANF) expression was identified by radioimmunoassay.


RESULTS
Treatment with AT1R-AS-ODNs for 24 h resulted in 51.2 % decrease in AT1R mRNA and 60.7 % in protein (P<0.05 vs control). However, the basal level of JNK activity, c-Jun protein expression, and DNA content were not altered by AT1R-AS treatment in absence of overactive hormonal system. After treatment with angiotensin II for 30 min, both p46JNK and p54JNK were robustly activated. By 2 h, c-Jun protein expression was increased. By 24 h, angiotensin II caused a marked increase both in G0/G1 and G2/M DNA content, and increased ANF expression by 1.8-fold. All these were inhibited by AT1R-AS-ODNs pretreatment. In contrast, sense sequence was ineffective.


CONCLUSIONS
Decrease of AT1R expression by AS-ODNs did not interfere with normal growth, but protected cardiomyocytes from angiotensin II-dependent pathophysiological growth.
Wang
Ying
Y
Department of Cardiology, Renmin Hospital, Wuhan University, Wuhan 430060, China. wangying6662001@yahoo.com.cn
Wang
Jin-ming
JM
Yan
Shu-xun
SX
Li
Ming-jiang
MJ
Li
Jian-jun
JJ
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D009320:Atrial Natriuretic Factor / Q000378:metabolism; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000502:physiology; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology*; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D044140:Receptor, Angiotensin, Type 1 / Q000096:biosynthesis* / Q000235:genetics
D020319:Oligodeoxyribonucleotides, Antisense; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D000804:Angiotensin II; D009320:Atrial Natriuretic Factor; D004247:DNA; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases