OBJECTIVE: To explore the inhibitory effect of calcitonin gene-related peptide (CGRP) on cardiomyocyte apoptosis and the underlying mechanism. METHODS: In cultured rat cardiomyocytes, apoptosis was induced by the incubation of isoprenaline (10(-5) mol/L) for 48 h. CGRP (10(-8) or 10(-7) mol/L) was administrated for 1 h before incubating isoprenaline to evaluate its effect on cardiomyocyte apoptosis. At the end of the drug treatment, the rate of apoptotic cells and intracellular reactive oxygen species (ROS) were determined, and RNA was extracted to examine the expression of microRNA-1 and microRNA-133a. RESULTS: Isoprenaline significantly increased the rate of apoptotic cells and intracellular ROS production concomitantly with the increased microRNA-1 expression and the decreased microRNA-133a expression, which were inhibited by pretreatment with CGRP. The effects of CGRP were reversed by CGRP receptor antagonist. CONCLUSION: CGRP can inhibit the isoprenaline-induced cardiomyocyte apoptosis. The beneficial effect of CGRP is related to regulating microRNA-1 and microRNA-133a expression through the prevention of isoprenaline-induced ROS production.
OBJECTIVE: To explore the inhibitory effect of calcitonin gene-related peptide (CGRP) on cardiomyocyte apoptosis and the underlying mechanism. METHODS: In cultured rat cardiomyocytes, apoptosis was induced by the incubation of isoprenaline (10(-5) mol/L) for 48 h. CGRP (10(-8) or 10(-7) mol/L) was administrated for 1 h before incubating isoprenaline to evaluate its effect on cardiomyocyte apoptosis. At the end of the drug treatment, the rate of apoptotic cells and intracellular reactive oxygen species (ROS) were determined, and RNA was extracted to examine the expression of microRNA-1 and microRNA-133a. RESULTS:Isoprenaline significantly increased the rate of apoptotic cells and intracellular ROS production concomitantly with the increased microRNA-1 expression and the decreased microRNA-133a expression, which were inhibited by pretreatment with CGRP. The effects of CGRP were reversed by CGRP receptor antagonist. CONCLUSION:CGRP can inhibit the isoprenaline-induced cardiomyocyte apoptosis. The beneficial effect of CGRP is related to regulating microRNA-1 and microRNA-133a expression through the prevention of isoprenaline-induced ROS production.