Rotigaptide (50 nM) increased gap junction mediated intercellular communication by 40% in HeLa cells expressing Cx43-GFP, with effects confined to cells expressing Cx43.
Rotigaptide specifically enhances gap junction intercellular communication in cells expressing Cx43, supporting its mechanism as an antiarrhythmic peptide.
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 et al. (Mon,) reported a other. Rotigaptide (ZP123) was evaluated on Gap junction mediated intercellular communication. Rotigaptide (50 nM) increased gap junction mediated intercellular communication by 40% in HeLa cells expressing Cx43-GFP, with effects confined to cells expressing Cx43.