고지방식이, 고과당식이, 콜라식이에 따른 소장의 부착연접 및 염증의 변화

Abstract

서론: 고지방식이와 고탄수화물식이가 비알코올성 지방간질환과 관련이 있다는 것은 널리 알려진 사실이다. 여러 연구에서 비알코올성 지방간질환과 증가된 장투과도가 연관되어 있다고 알려져 있다. 그러나 고지방식이나 고과당식이가 장의 부착연접이나 염증에 어떠한 영향을 미치는지는 아직 잘 알려져 있지 않아 이를 알아보고자 하였다. 방법: 37 마리의 수컷 백서를 고지방식이군, 고과당식이군, 콜라군, 대조군으로 나누었다. 소장에서 부착연접의 변화를 보기 위해 백서를 20주에 희생시켜 ZO-1 과 occludin에 대한 면역화학염색을 하였고, 염증 정도를 보기 위해 TLR４와 NOX4에 대한 면역화학염색을 하였다. 결과: ZO-1의 표현은 모든 실험군에서 대조군에 비해 감소하는 경향을 보였지만 통계적으로 유의한 차이는 없었다. Occludin에 대한 면역화학염색은 3+로 판독된 경우를 정상으로 분류했을 때 고지방식이군(28.7 % vs. 55.6%; p=0.042)과 콜라식이군 (33.3 % vs. 55.6%; p=0.004)이 대조군에 비해 정상인 비율이 통계적으로 유의하게 낮았다. TLR4에 대한 면역화학염색은 0과 1+로 염색된 것을 정상으로 분류했을 때 고지방식이군 (71.4% vs. 11.1 %; p=0.042)이 대조군에 비해 통계적으로 유의하게 TLR4의 발현이 증가된 결과를 보였다. NOX4의 발현은 모든 실험군에서 대조군에 비해 증가였으나 통계적으로 유의한 차이는 없었다. ZO-1의 발현의 증가와 TLR4의 발현의 감소가 통계적인 유의성이 있었으며 occludin과 TLR4는 연관성을 보이지 않았다. 결론: 고지방식이, 고과당식이, 콜라 식이를 한 군에서 부착연접이 감소하였고, 염증표지자는 증가하였다.|Objectives Nonalcoholic fatty liver disease (NAFLD) is associated with food composition including fat and fructose. Recently, it was also suggested that intestinal permeability and inflammation was increased in NAFLD. However, whether high-fat and high-fructose diets are associated with increased intestinal permeability and inflammation in NAFLD is not determined. Therefore, we investigated the effect of high-fat diet, high-fructose diet and soft drink on intestinal integrity and inflammation. Methods Thirty-seven male Sprague-Dawley rats (300-350 g) were divided into 4 groups, which were fed with a high-fat, high-fructose, cola, and control diet, respectively, for 20 weeks. To determine the effects of high-fat, high-fructose, and cola on intestinal integrity and inflammation, we assessed the integrity of epithelial tight junctions within the small intestine by immunohistochemical analysis of ZO-1 and occludin expression. We also performed immunohistochemical stain of inflammatory markers, TLR-4. Results Expression of ZO-1 in all experimental groups was lower than that in the control group. Expression of occludin in the high-fat diet group (28.7 % vs. 55.6 %; p=0.042) and cola-diet group (33.3 % vs. 55.6 %; p=0.004) was lower than that in the control group. Expression of TLR-4 in the high-fat diet group was higher than that in the control group (71.4 vs. 11.1; p=0.016). The intensity of duodenal Zo-1 staining is related to lower expression of TLR4 (p=0.036). But expression of occludin is not related to expression of TLR4. Expression of NOX4 is not related to expression of ZO-1 and occludin. Conclusions High-fat diet, high-fructose diet and cola may be related to disruption of tight junction integrity and increase in inflammation.; Objectives Nonalcoholic fatty liver disease (NAFLD) is associated with food composition including fat and fructose. Recently, it was also suggested that intestinal permeability and inflammation was increased in NAFLD. However, whether high-fat and high-fructose diets are associated with increased intestinal permeability and inflammation in NAFLD is not determined. Therefore, we investigated the effect of high-fat diet, high-fructose diet and soft drink on intestinal integrity and inflammation. Methods Thirty-seven male Sprague-Dawley rats (300-350 g) were divided into 4 groups, which were fed with a high-fat, high-fructose, cola, and control diet, respectively, for 20 weeks. To determine the effects of high-fat, high-fructose, and cola on intestinal integrity and inflammation, we assessed the integrity of epithelial tight junctions within the small intestine by immunohistochemical analysis of ZO-1 and occludin expression. We also performed immunohistochemical stain of inflammatory markers, TLR-4. Results Expression of ZO-1 in all experimental groups was lower than that in the control group. Expression of occludin in the high-fat diet group (28.7 % vs. 55.6 %