苏氨酸对大鼠小肠上皮细胞系IEC-6细胞活性和紧密连接蛋白表达的影响

Effects of Threonine on Activity and Tight Junction Protein Expression of Rat Intestinal Epithelia Cell Line IEC-6 Cell

本研究旨在探讨苏氨酸对大鼠小肠上皮细胞活性和增殖的影响,并研究苏氨酸是否对大鼠小肠上皮细胞紧密连接蛋白表达具有调控作用。试验采用不同浓度的苏氨酸(0、0.1、0.5、1.0、5.0、10.0 mmol/L)处理大鼠小肠上皮细胞系IEC-6细胞24 h,用噻唑兰(MTT)法测定IEC-6细胞活性,苏木精-伊红(HE)染色观察IEC-6细胞增殖情况,Western-blot法检测IEC-6细胞紧密连接蛋白表达情况。结果表明:各浓度的苏氨酸均能不同程度地提高IEC-6细胞的活性,0.5 mmol/L苏氨酸处理24 h时IEC-6细胞的活性最高,且与未经苏氨酸处理的对照组差异显著(P<0.05)。不同浓度的苏氨酸均能促进IEC-6细胞的增殖,且在苏氨酸浓度为0.5 mmol/L时促增殖作用最明显。与未经苏氨酸处理的对照组相比,0.1 mmol/L的苏氨酸对紧密连接蛋白claudin-3的表达未产生显著影响(P>0.05),但显著促进了occludin的表达(P <0.05);苏氨酸浓度为0.5、1.0、5.0、10.0 mmol/L时均显著促进上述2种紧密连接蛋白的表达(P <0.05),使claudin-3的相对表达量分别增加了1.84、7.08、8.71、3.83倍,occludin的相对表达量分别增加了2.65、2.71、2.82、3.88倍。综上,适宜浓度的苏氨酸对大鼠小肠上皮细胞系IEC-6细胞的活性和增殖具有促进作用,且在浓度为0.5 mmol/L时作用最显著,同时促进了紧密连接蛋白claudin-3和occludin的表达。

This experiment was to investigate the effects of threonine on the activity and proliferation of rat intestinal epithelial cells,and to explore whether threonine had regulation effect on tight junction protein expression of rat intestinal epithelial cells.Rat intestinal epithelial cell line IEC-6 cells were treated with different concentrations(0,0.1,0.5,1.0,5.0 and 10.0 mmol/L)of threonine for 24 h.The IEC-6 cell activity was determined using MTT method,the IEC-6 cell proliferation was observed through hematoxylin and eosin(HE)staining,and the expression of IEC-6 cell tight junction proteins claudin-3 and occludin were tested by Western-blot method.The results showed that different concentrations of threonine could increase the IEC-6 cell activity in varying degree,and the IEC-6 cell activity was the highest after explored to 0.5 mmol/L threonine for 24 h,and it significantly higher that the control group which not treated by threonine(P<0.05).IEC-6 cell proliferation also was enhanced by different concentrations of threonine,and the 0.5 mmol/L threonine group had best effect.Compared with the control group which not treated by threonine,threonine with the concentration of 0.1 mmol/L had no effect on the tight junction protein claudin-3 expression(P>0.05),but significantly increased the occludin expression(P<0.05).Compared with the control group which not treated by threonine,threonine with the concentrations of 0.5,1.0,5.0 and 10.0 mmol/L significantly increased the occludin and claudin-3 expression,the relative expression level of claudin-3 increased by 1.84,7.08,8.71 and 3.83 times,respectively,and the relative expression level of occluding increased by 2.65,2.71,2.82 and 3.88 times,respectively.In conclusion,threonine with properly concentration can improve the activity and proliferation of IEC-6,and 0.5 mmol/L threonine has the most significant effect.Meanwhile,the 0.5 mmol/L threonine up-regulates the expression of tight junction proteins claudin-3 and occludin.