Effects of monensin on tropoelastin metabolism in vascular smooth muscle cells: monensin causes intracellular degradation of accumulated tropoelastin.
Treatment with 80 nM monensin for 48 h resulted in impairment of tropoelastin secretion during the initial 6 h and subsequent reduction of tropoelastin synthesis from 18 to 48 h to one-tenth. The steady state level of tropoelastin mRNA started to decrease at 6 h and reached one-fifth of the control level by 48 h. A pulse-chase experiment after 24 h monensin treatment demonstrated that half of the accumulated tropoelastin in the cells was rapidly degraded within 120 min. These results indicate that the marked reduction in tropoelastin synthesis from 6 to 48 h treatment may be caused by both a reduction in the tropoelastin mRNA level and accelerated intracellular degradation of tropoelastin. Thus, monensin modulates tropoelastin expression through pretranslational and posttranslational mechanisms.
Ikeda
K
K
Department of Dermatology, National Defense Medical College, Saitama.
Wachi
H
H
Seyama
Y
Y
Tajima
S
S
D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D002642:Chick Embryo; D003470:Culture Media / Q000378:metabolism; D007476:Ionophores / Q000494:pharmacology; D008985:Monensin / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects; D013997:Time Factors; D014333:Tropoelastin / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*
D003470:Culture Media; D007476:Ionophores; D012333:RNA, Messenger; D014333:Tropoelastin; D008985:Monensin