The antiarrhythmic peptide rotigaptide (ZP123) increases gap junction intercellular communication in cardiac myocytes and HeLa cells expressing connexin 43.
We investigated the effects of rotigaptide (ZP123), a stable hexapeptide with antiarrhythmic properties, on gap junction mediated intercellular communication in contracting rat neonatal cardiac myocytes, HL-1 cells derived from cardiac atrium and in HeLa cells transfected with cDNA encoding Cx43-GFP, Cx32-GFP, Cx26-GFP, wild-type Cx43 or wild-type Cx26. Intercellular communication was monitored before and after treatment with rotigaptide following microinjection of small fluorescent dyes (MW<1 kDa). The communication-modifying effect of rotigaptide was confined to cells expressing Cx43 since the peptide had no effect on dye transfer in HeLa cells expressing Cx32-GFP, Cx26-GFP or wild-type Cx26. In contrast, HeLa cells expressing Cx43-GFP exposed to 50 nM rotigaptide for 5 h showed a 40% increase in gap junction mediated communication. Rotigaptide (50 nM) increased intercellular dye transfer in myocytes and atrial HL-1 cells, where Cx43 is the dominant connexin. However, it caused no change in cell beating rates of cardiac myocytes. Western blot analysis showed that rotigaptide did not modify the overall level of Cx43 expression and changes in the phosphorylation status of the protein were not observed.We conclude that the effects of rotigaptide were confined to cells expressing Cx43.
Clarke
Thomas C
TC
Department of Medical Biochemistry and Immunology & Wales Heart Research Institute, Cardiff University, Cardiff, Wales.
Thomas
Dafydd
D
Petersen
Jørgen S
JS
Evans
W Howard
WH
Martin
Patricia E M
PE
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D002450:Cell Communication / Q000187:drug effects*; D000072259:Connexin 26; D018031:Connexin 43 / Q000032:analysis / Q000502:physiology*; D017630:Connexins / Q000032:analysis; D017629:Gap Junctions / Q000187:drug effects* / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D032383:Myocytes, Cardiac / Q000737:chemistry / Q000187:drug effects*; D009842:Oligopeptides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D000889:Anti-Arrhythmia Agents; D018031:Connexin 43; D017630:Connexins; C000607042:GJB2 protein, human; C000607044:Gjb2 protein, rat; D009842:Oligopeptides; D000072259:Connexin 26; C477643:rotigaptide