Regulation of naturally occurring antisense RNA of myosin heavy chain (MyHC) in neonatal cardiomyocytes.
Naturally occurring antisense RNA has been detected for a range of eukaryotic genes. Its abundance compared to levels of its complementary sense mRNA appears to be a factor indicating its possible regulatory function. In previous studies, we detected appreciable levels of antisense RNA against the two isoforms (alpha and beta) of the heavy myosin-chain (MyHC) in the myocardium of rats. If this is to play a significant role in gene expression antisense levels should vary in response to external and internal cellular influences. Recently, a bidirectional promoter located in the alpha/beta MyHC intergenic region was described, which was proposed to regulate coordinated transcription of alpha-MyHC sense and beta-MyHC antisense. To study MyHC antisense regulation in neonatal heart, we investigated cultivated myocytes stimulated with either trijodthyronin (T3) as an inductor of alpha-MyHC or phenylephrine with stimulation of beta-MyHC. RNA-quantification of sense and antisense transcripts of both isoforms was performed by real-time RT-PCR. Stimulation by T3 led to an induction of both sense and antisense of alpha-MyHC and to a decrease of beta-MyHC sense and antisense. Phenylephrine increased sense and antisense beta-MyHC but reduced antisense alpha-MyHC. The sense/antisense of alpha- and beta-MyHC ratio was unchanged compared to control. Results indicate a coregulation of sense and antisense MyHC RNA under stimulation of T3 and phenylephrine in neonatal cardiomyocytes.
Luther
H P
HP
Medical Clinic I, Department of Cardiology, Humboldt-University (Charité), Ziegelstr. 5-9, D10117 Berlin, Germany. hanspeter.luther@charite.de
Bartsch
H
H
Morano
I
I
Podlowski
S
S
Baumann
G
G
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000235:genetics*; D010656:Phenylephrine / Q000494:pharmacology; D016372:RNA, Antisense / Q000235:genetics*; D051381:Rats; D017208:Rats, Wistar; D014284:Triiodothyronine / Q000494:pharmacology
D016372:RNA, Antisense; D014284:Triiodothyronine; D010656:Phenylephrine; D018995:Myosin Heavy Chains