Study On The Adjustment Of Iodine Excess To Endoplasmic Reticulum Stress Specific Apoptosis Protein Expression In Human Thyroid Follicular Cells

ObjectiveTwo chamber follicular model are formed out of the body to explore the adjustment of iodine excess to endoplasmic reticulum stress and endoplasmic reticulum stress specific apoptosis protein expression in thyroid follicular cells.MethodsCultivate the human thyroid follicular cells in logarithmic growth phase in a Transwell room to form two chamber follicular model.Arsenic cerium catalytic spectrophotometry was applied to test iodine content in the upper and lower chamber of the model to prove the iodine uptake in the thyroid follicular model of two chambers.Take the model as experimental research object to have high concentration of potassium iodide and endoplasmic reticulum stress reliever 4-phenyl butyric acid(4-PBA)intervention.Western-blot was applied to test the expression of endoplasmic reticulum stress protein GRP78,ATF4 and endoplasmic reticulum stress specific apoptosis protein Caspase-12,CHOP after intervention.Results1.Within the groups,the iodine concentration in the upper chamber(follicular cavity)and lower chamber were 213.33±5.686ug/L and 112.67±3.055ug/L,respectively.Statistical significance was observed between these two results by pared t-test(p<0.01),that is iodine concentration in upper chamber was remarkably higher than lower chamber;2.The relative expression of ATF4 in high-I group was 0.37±0.078,with 0.14±0.021 in the control group.The difference was statistically significant by pared t-test(p<0.05),that is ATF4 expression in high-I group was higher than the controls;the relative expression of CHOP in high-I group was 0.85±0.218,with 0.13±0.015 in the control group.The difference was statistically significant by pared t-test(p<0.05),that is CHOP expression in high-I group was higher than the controls;the relative expression of GRP78 in high-I group was 0.31±0.137,with 0.19±0.203 in the control group,but no statistical significance was observed by paired t-test(p>0.05),which means no significant difference in GRP78 expression between high-I group and control group;the relative expression of Caspase-12 in high-I group was 0.64±0.147,with 0.40±0.282 in the control group,but no statistical significance was observed by paired t-test(p>0.05),which means no significant difference in Caspase-12 expression between high-I group and control group.3.The relative expression of ATF4 in high-I group was 0.37±0.078,with 0.03±0.014 in the high-I + 4-PBA group.The difference was statistically significant by pared t-test(p<0.05),that is ATF4 expression in high-I group was higher than the high-I +4-PBA group;the relative expression of CHOP in high-I group was 0.85±0.218,with0.25±0.124 in the high-I + 4-PBA group.The difference was statistically significant by pared t-test(p<0.05),that is CHOP expression in high-I group was higher than the high-I + 4-PBA group;the relative expression of GRP78 in high-I group was0.31±0.137,with 0.20±0.090 in the high-I + 4-PBA group.No significant difference was observed between the results by pared t-test(p>0.05),which means no significant difference in GRP78 expression was obtained between high-I group and high-I +4-PBA group;the relative expression of Caspase-12 in high-I group was 0.64±0.147,with 0.34±0.010 in the high-I + 4-PBA group.No significant difference was observed between the results by pared t-test(p>0.05),which means no significant difference in Caspase-12 expression was gained between high-I group and high-I + 4-PBA group.Conclusions1.Two chamber follicular model could simulate the structure and function of thyroid follicle successfully and the thyroid follicular cell of the model has absorption andtransport of iodine these functions.2.High iodine selectively activates human thyroid follicular cells endoplasmic reticulum stress specific ATF4-CHOP apoptosis pathway while it has no difference to the endoplasmic reticulum stress specific Caspase-12 apoptosis pathway.