Interleukin-6 increases insulin secretion and preproinsulin mRNA expression via Ca2+-dependent mechanism

in Journal of Endocrinology

Interleukin (IL)-6, one of the cytokines released from inflammatory cells, stimulates insulin secretion in a physiological concentration (1-100 pg/ml), but the exact mechanism is still unknown. The present studies were undertaken to investigate the mechanism of IL-6-induced stimulation of insulin secretion in HIT-T 15 cells. The effects of the addition of nifedipine on the IL-6 (100 pg/ml)-induced stimulation of insulin secretion were investigated. We also examined the possibility that IL-6 (1-100 pg/ml) may stimulate insulin messenger ribonucleic acid (mRNA) expression, using the reverse transcription-polymerase chain reaction method. The addition of 100 and 1000 nM nifedipine significantly attenuated the stimulatory effects of 100 pg/ml IL-6 on insulin secretion. The addition of 1-100 pg/ml IL-6 dose-dependently increased preproinsulin mRNA expression relative to beta-actin mRNA. IL-6 increased insulin gene promoter activity of fragments A (-2188 to +337 bp) and B (-1782 to +270 bp) but not fragments C (-1275 to +270 bp), D (-1138 to +270 bp), E (-880 to +236 bp) or F (-356 to +252 bp). The addition of 10 nM nifedipine completely abolished the stimulatory effect of 10-100 pg/ml IL-6 on relative preproinsulin mRNA expression. These data raised the possibility that IL-6 increased preproinsulin mRNA expression via the stimulation of Ca(2+) influx which enhances insulin gene expression.

If the inline PDF is not rendering correctly, you can download the PDF file here.


      Society for Endocrinology

Sept 2018 onwards Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 163 39 1
PDF Downloads 89 35 1