GW24-e2991 Protective effect of cardiotrophin-1 in preventing acute cardiomyocyte hypoxia- reoxygeonation injury mediated by supressor of cytokine signalling 1--SOCS1/stat3 pathway

Objectives To investigate the signalling pathways supressor of cytokine signalling 1 (SOCS1) how to involve in the protective effect of CT-1 in preventing cardiomyocyte I/R injury from cellular and molecular aspects. Methods Cardiomyocytes from the hearts of 1∼3-day-old neonatal rats (Sprague-Dawley) were prepared by a modification of a previously published protocol. There were seven groups in the experiment : 1) control group: cultivated with DMEM for 6h; 2) hypoxia-reoxygeonation group: 3) CT-1 group; 4) ASODN group1 and group 2: antisense oligonucleotides group (two antisense SOCS1 groups) : 5) SODN group (sense oligonucleotides SOCS1 group); 6) ScODN group (scrambled oligonucleotides SOCS1 group). Myocytes survival rate was evaluated by MTS method, apoptosis, mitochondrial permeability transition pore (Δψm) and reactive oxygen species (ROS) were detected by flow cytometer. SOCS1 and STAT3 protein by western blotting. Results Cardiomyocyte apoptosis and ROS increased markedly after hypoxia/reoxygenation, but cardiomyocyte survival rate and the level of Δψm decreased significantly. With CT-1 intervention, cardiomyocyte survival rate increased markedly (87%), apoptosis and ROS reduced significantly Δψm was lower and the ROS was higher than those in CT-1 group after giving antisense SOCS1 infection, but it was similar to that in CT-1 group after sense SOCS1 or scrambled SOCS1 infection. After hypoxia-reoxygeonation, Expression of SOCS1 mRNA and SOCS1 protein increased somewhat comparing with control group, but there no significant difference. However,expression of both SOCS1 mRNA and SOCS1 protein in CT-1 group increased apparently comparing with hypoxia-reoxygeonation group. Phosphorylated STAT3 increased obviously after processing with SOCS1 antisense oligonucleotides. Conclusions Supressor of cytokine signalling 1--SOCS1/STAT3 pathway may mediate the protection of CT-1 in preventing acute cardiomyocyte hypoxia- reoxygeonation injury.