Department of Nutrition and Movement Sciences, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.
J Cell Biochem. 2019 Oct;120(10):17219-17227. doi: 10.1002/jcb.28982. Epub 2019 May 20.
Apolipoprotein-I (ApoA-I), the major component of high-density lipoprotein (HDL) particles, mediates cholesterol efflux by which it facilitates the removal of excess cholesterol from peripheral tissues. Therefore, elevating ApoA-I production leading to the production of new pre-β-HDL particles is thought to be beneficial in the prevention of cardiovascular diseases. Recently, we observed that amoxicillin treatment led to decreased HDL concentrations in healthy human volunteers. We questioned whether this antibiotic effect was directly or indirectly, via changed short-chain fatty acids (SCFA) concentrations through an altered gut microflora. Therefore, we here evaluated the effects of amoxicillin and various SCFA on hepatic ApoA-I expression, secretion, and the putative underlying pathways.
Human hepatocytes (HepG2) were exposed to increasing dose of amoxicillin or SCFA for 48 hours. ApoA-I messenger RNA (mRNA) transcription and secreted protein were analyzed using quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. To study underlying mechanisms, changes in mRNA expression of KEAP1, CPT1, and PPARα, as well as a PPARα transactivation assay, were analyzed. Amoxicillin dose-dependently decreased ApoA-I mRNA transcription as well as ApoA-I protein secretion. SCFA treatment resulted in a dose-dependent stimulation of ApoA-I mRNA transcription, however, the ApoA-I protein secretion was decreased. Furthermore, SCFA treatment increased PPARα transactivation, PPARα and CPT1 mRNA transcription, whereas KEAP1 mRNA transcription was decreased.
Direct treatment of HepG2 cells with amoxicillin has either direct effects on lowering ApoA-I transcription and secretion or indirect effects via modified SCFA concentrations because SCFA were found to stimulate hepatic ApoA-I expression. Furthermore, BET inhibition and PPARα activation were identified as possible mechanisms behind the observed effects on ApoA-I transcription.
载脂蛋白-I（ApoA-I）是高密度脂蛋白（HDL）颗粒的主要成分，通过介导胆固醇外排，促进外周组织中多余胆固醇的清除。因此，提高 ApoA-I 的产生，导致新的前-β-HDL 颗粒的产生，被认为有益于预防心血管疾病。最近，我们观察到阿莫西林治疗导致健康志愿者的 HDL 浓度降低。我们质疑这种抗生素作用是直接的还是间接的，通过改变短链脂肪酸（SCFA）浓度，通过改变肠道微生物群。因此，我们在这里评估了阿莫西林和各种 SCFA 对肝 ApoA-I 表达、分泌的影响，以及潜在的潜在途径。
人肝细胞（HepG2）暴露于递增剂量的阿莫西林或 SCFA 48 小时。使用定量聚合酶链反应和酶联免疫吸附试验分别分析 ApoA-I 信使 RNA（mRNA）转录和分泌蛋白。为了研究潜在机制，分析了 KEAP1、CPT1 和 PPARα 的 mRNA 表达变化，以及 PPARα 反式激活测定。阿莫西林剂量依赖性地降低 ApoA-I mRNA 转录和 ApoA-I 蛋白分泌。SCFA 处理导致 ApoA-I mRNA 转录剂量依赖性刺激，然而，ApoA-I 蛋白分泌减少。此外，SCFA 处理增加了 PPARα 反式激活、PPARα 和 CPT1 mRNA 转录，而 KEAP1 mRNA 转录减少。
阿莫西林直接作用于 HepG2 细胞，要么直接降低 ApoA-I 转录和分泌，要么通过改变 SCFA 浓度间接影响，因为发现 SCFA 刺激肝 ApoA-I 表达。此外，BET 抑制和 PPARα 激活被确定为观察到的 ApoA-I 转录影响的可能机制。
