Abstract：Objective To study the possible mechanism of medium-chain fatty acid (MCFA) in reducing body weight by observing the effect of MCFA on the expression of TLR4 signaling pathway related molecules in small intestine tissues of mice with obesity induced by high-fat diet. Methods Thirty-six C57BL/6J high-fat diet-induced obese mice were randomly divided into octanoic acid group, capric acid group and oleic acid group (each n=12) according to their fasting body weight. After exposure to the high-fat diets (containing 2% octanoic acid(C8:0), capric acid (C10:0)and oleic acid (C18:1) respectively) for 16 weeks, their body, liver and mesenteric, epididymal and perirenal fat pads were weighed. Meanwhile, lipid metabolism related indexes in serum were measured. Tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1 (IL-1) levels in small intestine were measured by ELISA. The expression of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and TNF-α mRNA in small intestine tissues were measured by real-time RT-PCR. Results The weight of body, liver and epididymal fat pads, the level of TNF-α and the expression of TLR4 mRNA in small intestine tissues were significantly lower in octanoic acid group and capric acid group than in oleic acid group (all P<0.05). The concentrations of total cholesterol (TC) and free fatty acid (FFA) in serum, the levels of IL-6 and IL-1 and the expression of MyD88 and TNF-α mRNA in small intestine tissues were significantly lower in octanoic acid group than in oleic acid group (all P<0.05), whereas the serum concentration of high-density lipoprotein cholesterol (HDL-C) and the ratio of serum HDL-C to LDL-C (low-density lipoprotein cholesterol) were significantly higher in octanoic acid group than in oleic acid group (both P<0.05). The levels of triglyceride (TG) and free fatty acid (FFA) in serum were significantly lower in capric acid group than in oleic acid group (both P<0.05). Conclusions MCFA may effectively reduce the body weight of obese individuals via reducing inflammatory factors by down-regulating TLR4 signaling pathway related molecules in small intestine tissues.
赵晓, 张永, 张新胜, 徐庆, 于晓明, 刘鹿, 刘英华, 薛长勇. 中链脂肪酸对肥胖C57BL/6J小鼠小肠TLR4传导通路分子表达的影响[J]. 实用预防医学, 2017, 24(8): 916-919.
ZHAO Xiao, ZHANG Yong, ZHANG Xin-sheng, XU Qing, YU Xiao-ming, LIU Lu, LIU Ying-hua, XUE Chang-yong. Effect of medium-chain fatty acid on the expression of TLR4 pathway related molecules in small intestine of C57BL/6J mice with obesity. , 2017, 24(8): 916-919.
[1] Xue C,Liu Y,Wang J,et al.Chinese hypertriglycerideamic subjects of different ages responded differently to consuming oil with medium- and long-chain fatty acids[J].Biosci Biotechnol Biochem,2009,73(8):1711-1717. [2] Zhang Y,Xu Q,Liu YH,et al.Medium-Chain triglyceride activated brown adipose tissue and induced reduction of fat mass in C57BL/6J mice fed high-fat diet[J].Biomed Environ Sci,2015,28(2):97-104. [3] Liu YH,Xue CY,Zhang Y,et al.Triglyceride with medium-chain fatty acids increases the activity and expression of hormone-sensitive lipase in white adipose tissue of C57BL/6J mice[J].Biosci Biotechnol Biochem,2011,75(10):1939-1944. [4] Olson NC, Callas PW, Hanley AJ,et al. Circulating levels of TNF-αlpha are associated with impaired glucose tolerance, increased insulin resistance, and ethnicity:the insulin resistance atherosclerosis study[J]. J Clin Endocrinol Metab, 2012,97(3):1032-1040. [5] Bose KS, Gupta SK, Vyas P. Adipocytokine levels in genetically high risk for type 2 diabetes in the Indian population: a cross-sectional study[J].Exp Diabetes Res,2012:386524. [6] Kalupahana NS, Moustaid-Moussa N, Claycombe KJ. Immunity as a link between obesity and insulin resistance[J]. Mol Aspects Med,2012,33(1):26-34. [7] Osborn O,Olefsky JM. The cellular and signaling networks linking the immune system and metabolism in disease[J]. Nat Med,2012,18(3):363-374. [8] Gioannini TL,Weiss JP. Regulation of interactions of Gram-negative bacterial endotoxins with mammalian cells[J]. Immunol Res,2007,39(1-3):249-260. [9] Kang S,Lee SP,Kim KE,et al.Toll-like receptor 4 in lymphatic endothelial cells comtributes to LPS-induced lymphangiogenesis by chemotactic recruitment of macrophages[J].Blood,2009,113(11):2605-2613. [10] Ding S,Chi MM,Scull BP,et al. High-fat diet:bacteria interactions promote intestinal inflammation,which precedes and correlates with obesity and insulin resistance in mouse[J]. PLoS One,2010,5(8):e12191.
2017, Vol. 24 
