Cellular memory of high glucose exposure in normoglycemia is probably mediated by reactive oxygen species in INS-1 cells / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the cellular memory of previous high glucose exposure in rat islet cell line (INS-1) and explore the possible mechanism.</p><p><b>METHODS</b>INS-1 cells were exposed to a high glucose (33.3 mmol/L) culture for 48 h followed by further culture in the presence of 11.1 mmol/L glucose in the culture medium for 3 or 5 days. The levels of bax and caspase-3 mRNA were measured by real-time PCR, the production of reactive oxygen species (ROS) was assayed using the dihydroethidium probe, and the cell viability was detected by MTT assay.</p><p><b>RESULTS</b>High glucose exposure of the cells for 48 h resulted in significantly increased ROS production and bax and caspase-3 mRNA expressions and lowered cell viability (P<0.001). In cells cultured in 11.1 mmol/L glucose following previous high glucose exposure, the ROS production and bax and caspase-3 mRNA expressions still maintained the high levels (P<0.05) while the cell viability remained significantly lower than the control cells (P<0.001).</p><p><b>CONCLUSION</b>High glucose causes persistent changes in cell viability and apoptosis-related gene expressions even after recovery of normoglycemia, the mechanism of which is probably related to increased ROS production.</p>