Mena Sandra J, Manosalva Carolina, Carretta Maria D, Teuber Stefanie, Olmo Iván, Burgos Rafael A, Hidalgo Maria A
Laboratory of Molecular Pharmacology, Institute of Pharmacology, Faculty of Veterinary Science, Universidad Austral de Chile, Valdivia, Chile Department of Biology, Universidad de Nariño, Pasto, Colombia.
Laboratory of Molecular Pharmacology, Institute of Pharmacology, Faculty of Veterinary Science, Universidad Austral de Chile, Valdivia, Chile Institute of Pharmacy, Faculty of Sciences, Universidad Austral de Chile, Valdivia, Chile.
Innate Immun. 2016 Aug;22(6):479-89. doi: 10.1177/1753425916656765. Epub 2016 Jun 30.
Fatty acids have been recognized as regulators of immune function in addition to their known metabolic role. Long-chain fatty acids bind free fatty acid receptor (FFAR)-1/GPR40, which is expressed on bovine neutrophils, and increase responses such as granule release and gene expression. In this study, we investigated the molecular mechanisms governing the up-regulation of cyclooxygenase-2 (COX-2) and IL-8, as well as matrix metalloproteinase (MMP)-9 granule release in FFAR1/GPR40 agonist-stimulated neutrophils. Our results showed that natural (oleic and linoleic acid) and synthetic (GW9508) FFAR1/GPR40 agonists increased ERK1/2, p38 MAPK and Akt phosphorylation, and that the FFAR1/GPR40 antagonist GW1100 reduced these responses. We evaluated the levels of IκBα, a component of the classical activation pathway of the transcription factor NF-κB, and we observed IκBα reduction after stimulation with FFAR1/GPR40 agonists, an effect that was inhibited by GW1100 or the inhibitors UO126, SB203580 or LY294002. FFAR1/GPR40 agonists increased COX-2 and IL-8 expression, which was inhibited by GW1100 and an NF-κB inhibitor. Finally, the FFAR1/GPR40 agonist-induced MMP-9 granule release was reduced by GW1100 and UO126. In conclusion, FFAR1/GPR40 agonists differentially stimulate neutrophil functions; COX-2 and IL-8 are expressed after FFAR1/GPR40 activation via NF-κB, IκBα reduction is FFAR1/GPR40- and PI3K/MAPK-dependent, and MMP-9 granule release is FFAR1/GPR40- and ERK1/2-dependent.
脂肪酸除了具有已知的代谢作用外，还被认为是免疫功能的调节因子。长链脂肪酸与游离脂肪酸受体（FFAR）-1/GPR40结合，该受体在牛中性粒细胞上表达，并增加颗粒释放和基因表达等反应。在本研究中，我们调查了在FFAR1/GPR40激动剂刺激的中性粒细胞中，调控环氧合酶-2（COX-2）、白细胞介素-8（IL-8）上调以及基质金属蛋白酶（MMP）-9颗粒释放的分子机制。我们的结果表明，天然（油酸和亚油酸）和合成（GW9508）的FFAR1/GPR40激动剂增加了细胞外信号调节激酶1/2（ERK1/2）、p38丝裂原活化蛋白激酶（MAPK）和蛋白激酶B（Akt）的磷酸化，而FFAR1/GPR40拮抗剂GW1100降低了这些反应。我们评估了转录因子核因子κB（NF-κB）经典激活途径的一个组成部分——IκBα的水平，并且我们观察到用FFAR1/GPR40激动剂刺激后IκBα减少，这一效应被GW1100或抑制剂UO126、SB203580或LY294002抑制。FFAR1/GPR40激动剂增加了COX-2和IL-8的表达，这被GW1100和一种NF-κB抑制剂抑制。最后，GW1100和UO126减少了FFAR1/GPR40激动剂诱导的MMP-9颗粒释放。总之，FFAR1/GPR40激动剂以不同方式刺激中性粒细胞功能；COX-2和IL-8在FFAR1/GPR40激活后通过NF-κB表达，IκBα减少是FFAR1/GPR40和磷脂酰肌醇-3激酶/丝裂原活化蛋白激酶（PI3K/MAPK）依赖性的，而MMP-9颗粒释放是FFAR1/GPR40和ERK1/2依赖性的。
