Details
| Original language | English |
|---|---|
| Pages (from-to) | 409-19 |
| Number of pages | 11 |
| Journal | Journal of Bioenergetics and Biomembranes |
| Volume | 45 |
| Issue number | 4 |
| Publication status | Published - Aug 2013 |
Abstract
Previous data showed that dipyridamole enhanced gap junction coupling in vascular endothelial and smooth muscle cell lines by a cAMP-dependent mechanism. The present study investigates the level at which dipyridamole affects gap junction coupling. In the GM-7373 endothelial cell line, scrape loading/dye transfer experiments revealed a rapid increase in gap junction coupling induced during the first 6 h of dipyridamole treatment, followed by a slow increase induced by further incubation. Immunostaining analyses showed that the rapid enhancement of gap junction coupling correlated with an increased amount of Cx43 gap junction plaques and a reduced amount of Cx43 containing vesicles, while the amount of Cx43 mRNA or protein was not changed during this period, as found by semiquantitative RT-PCR and Western blot. Additionally, brefeldin A did not block this short-term-induced enhancement of gap junction coupling. Along with the dipyridamole-induced long-term enhancement of gap junction coupling, the amount of Cx43 mRNA and protein additionally to the amount of Cx43 gap junction plaques were increased. Furthermore, the anti-Cx43 antibody detected only two bands at 42 kDa and 44 kDa in control cells and cells treated with dipyridamole for 6 h, while long-term dipyridamole-treated cells showed a third band at 46 kDa. We propose that a dipyridamole-induced cAMP synthesis increased gap junction coupling in the GM-7373 endothelial cell line at different levels: the short-term effect is related to already oligomerised connexins beyond the Golgi apparatus and the long-term effect involves new expression and synthesis as well as posttranslational modification of Cx43.
Keywords
- Cells, Cultured, Connexin 43/genetics, Dipyridamole/pharmacology, Endothelial Cells/cytology, Gap Junctions/drug effects, Humans, Phosphorylation, RNA, Messenger/genetics
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In: Journal of Bioenergetics and Biomembranes, Vol. 45, No. 4, 08.2013, p. 409-19.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Dipyridamole-related enhancement of gap junction coupling in the GM-7373 aortic endothelial cells correlates with an increase in the amount of connexin 43 mRNA and protein as well as gap junction plaques
AU - Begandt, Daniela
AU - Bader, Almke
AU - Gerhard, Linda
AU - Lindner, Julia
AU - Dreyer, Lutz
AU - Schlingmann, Barbara
AU - Ngezahayo, Anaclet
N1 - Funding information: Acknowledgments The work was supported by Boehringer Ingelheim International GmbH. The authors thank Prof. Dr. Wolfgang Eisert for discussion and comments on the manuscript.
PY - 2013/8
Y1 - 2013/8
N2 - Previous data showed that dipyridamole enhanced gap junction coupling in vascular endothelial and smooth muscle cell lines by a cAMP-dependent mechanism. The present study investigates the level at which dipyridamole affects gap junction coupling. In the GM-7373 endothelial cell line, scrape loading/dye transfer experiments revealed a rapid increase in gap junction coupling induced during the first 6 h of dipyridamole treatment, followed by a slow increase induced by further incubation. Immunostaining analyses showed that the rapid enhancement of gap junction coupling correlated with an increased amount of Cx43 gap junction plaques and a reduced amount of Cx43 containing vesicles, while the amount of Cx43 mRNA or protein was not changed during this period, as found by semiquantitative RT-PCR and Western blot. Additionally, brefeldin A did not block this short-term-induced enhancement of gap junction coupling. Along with the dipyridamole-induced long-term enhancement of gap junction coupling, the amount of Cx43 mRNA and protein additionally to the amount of Cx43 gap junction plaques were increased. Furthermore, the anti-Cx43 antibody detected only two bands at 42 kDa and 44 kDa in control cells and cells treated with dipyridamole for 6 h, while long-term dipyridamole-treated cells showed a third band at 46 kDa. We propose that a dipyridamole-induced cAMP synthesis increased gap junction coupling in the GM-7373 endothelial cell line at different levels: the short-term effect is related to already oligomerised connexins beyond the Golgi apparatus and the long-term effect involves new expression and synthesis as well as posttranslational modification of Cx43.
AB - Previous data showed that dipyridamole enhanced gap junction coupling in vascular endothelial and smooth muscle cell lines by a cAMP-dependent mechanism. The present study investigates the level at which dipyridamole affects gap junction coupling. In the GM-7373 endothelial cell line, scrape loading/dye transfer experiments revealed a rapid increase in gap junction coupling induced during the first 6 h of dipyridamole treatment, followed by a slow increase induced by further incubation. Immunostaining analyses showed that the rapid enhancement of gap junction coupling correlated with an increased amount of Cx43 gap junction plaques and a reduced amount of Cx43 containing vesicles, while the amount of Cx43 mRNA or protein was not changed during this period, as found by semiquantitative RT-PCR and Western blot. Additionally, brefeldin A did not block this short-term-induced enhancement of gap junction coupling. Along with the dipyridamole-induced long-term enhancement of gap junction coupling, the amount of Cx43 mRNA and protein additionally to the amount of Cx43 gap junction plaques were increased. Furthermore, the anti-Cx43 antibody detected only two bands at 42 kDa and 44 kDa in control cells and cells treated with dipyridamole for 6 h, while long-term dipyridamole-treated cells showed a third band at 46 kDa. We propose that a dipyridamole-induced cAMP synthesis increased gap junction coupling in the GM-7373 endothelial cell line at different levels: the short-term effect is related to already oligomerised connexins beyond the Golgi apparatus and the long-term effect involves new expression and synthesis as well as posttranslational modification of Cx43.
KW - Cells, Cultured
KW - Connexin 43/genetics
KW - Dipyridamole/pharmacology
KW - Endothelial Cells/cytology
KW - Gap Junctions/drug effects
KW - Humans
KW - Phosphorylation
KW - RNA, Messenger/genetics
U2 - 10.1007/s10863-013-9518-8
DO - 10.1007/s10863-013-9518-8
M3 - Article
C2 - 23800832
VL - 45
SP - 409
EP - 419
JO - Journal of Bioenergetics and Biomembranes
JF - Journal of Bioenergetics and Biomembranes
SN - 0145-479X
IS - 4
ER -