Miyoshi Makoto, Usami Makoto, Ohata Atsushi
Division of Nutrition and Metabolism, Kobe University Graduate School of Health Sciences, Kobe, Japan.
Nutrition. 2008 Nov-Dec;24(11-12):1189-98. doi: 10.1016/j.nut.2008.06.012. Epub 2008 Aug 23.
The short-chain fatty acids (SCFAs), butyrate, propionate, and acetate, produced by bacterial fermentation of dietary fiber, can modulate the transcription of certain genes by inhibiting histone deacetylase in colonocytes and several other cell types in vitro. We previously reported that butyrate decreases tight junction permeability by activating lipoxygenase (LOX) in intestinal monolayer cells. In the present study, we evaluated the effects of SCFAs on tight junction permeability in an endothelial cell culture and their possible mechanisms of action via histone deacetylase inhibitor activity. We also investigated the factors modulating tight junction permeability.
The effects of butyrate, propionate, and acetate on tight junction permeability in human umbilical vein endothelial cells were examined using Transwell chamber cultures. The contributions of inducible nitric oxide synthase (NOS), endothelial NOS, estrogen receptor, cyclo-oxygenase, and LOX to SCFAs' effects were also evaluated. The effects of SCFAs were compared with those of trichostatin A, a typical histone deacetylase inhibitor.
Low concentrations of butyrate and propionate decreased paracellular permeability without inducing cell damage. However, acetate decreased paracellular permeability in a concentration-dependent manner. An estrogen receptor antagonist attenuated the effects of SCFAs on tight junction permeability. The influences of inducible NOS, cyclo-oxygenase, and LOX inhibitors and the expressions of cyclo-oxygenase and LOX mRNAs were different for each SCFA. Trichostatin A slightly decreased paracellular permeability when used at lower concentrations, but higher concentrations of trichostatin A increased permeability.
The SCFAs play an important role in the assembly of tight junctions in normal vascular endothelial cells.
膳食纤维经细菌发酵产生的短链脂肪酸(SCFAs),即丁酸、丙酸和乙酸,可通过抑制结肠细胞和其他几种细胞类型中的组蛋白脱乙酰酶来调节某些基因的转录。我们之前报道过,丁酸通过激活肠道单层细胞中的脂氧合酶(LOX)来降低紧密连接通透性。在本研究中,我们评估了SCFAs对内皮细胞培养中紧密连接通透性的影响及其通过组蛋白脱乙酰酶抑制剂活性的可能作用机制。我们还研究了调节紧密连接通透性的因素。
使用Transwell小室培养法检测丁酸、丙酸和乙酸对人脐静脉内皮细胞紧密连接通透性的影响。还评估了诱导型一氧化氮合酶(NOS)、内皮型NOS、雌激素受体、环氧化酶和LOX对SCFAs作用的贡献。将SCFAs的作用与典型的组蛋白脱乙酰酶抑制剂曲古抑菌素A的作用进行比较。
低浓度的丁酸和丙酸可降低细胞旁通透性,且不引起细胞损伤。然而,乙酸以浓度依赖的方式降低细胞旁通透性。雌激素受体拮抗剂可减弱SCFAs对紧密连接通透性的影响。每种SCFA对诱导型NOS、环氧化酶和LOX抑制剂的影响以及环氧化酶和LOX mRNA的表达各不相同。曲古抑菌素A在较低浓度使用时可轻微降低细胞旁通透性,但较高浓度的曲古抑菌素A会增加通透性。
SCFAs在正常血管内皮细胞紧密连接的组装中起重要作用。