Bergamini Gabriella, Cigana Cristina, Sorio Claudio, Della Peruta Marco, Pompella Alfonso, Corti Alessandro, Huaux François A, Leal Teresinha, Assael Baroukh M, Melotti Paola
Cystic Fibrosis Center-Azienda Ospedaliera di Verona, Piazzale Stefani 1, 37126 Verona, Italy.
Am J Respir Cell Mol Biol. 2009 Aug;41(2):199-206. doi: 10.1165/rcmb.2008-0013OC. Epub 2008 Dec 18.
Anti-inflammatory properties of azithromycin (AZM) have been proposed as possible mechanisms of clinical beneficial effects in patients with cystic fibrosis (CF). Altered glutathione (GSH) transport in cystic fibrosis transmembrane regulator protein (CFTR)-deficient cells leads to the occurrence of oxidative stress that finally induces glutathione S-transferase (GST) activity. The present investigation was aimed to verify the effects of AZM on GST activity and expression in CF airway cells in vitro and in vivo. AZM exposure significantly decreased GSTT1 and GSTM1 mRNA and protein expression in IB3-1, restoring the levels to those observed in non-CF C38 cells, which also express lower levels of gamma-glutamyltransferase (GGT) activity than IB3-1. In another CF cell line, 2CFSMEo-, AZM produced 45% reduction in GSTT1 and GSTM1 mRNA levels. AZM reduced GST activity by approximately 25% and 40% in IB3-1 and 2CFSMEo- cells, respectively. GSTP1 was similarly expressed in all CF and non-CF cells and was unaffected by AZM. The anti-inflammatory cytokine IL-10 down-modulated GST activity at similar levels, supporting a link between GST inhibition and anti-inflammatory properties of AZM. In bronchoalveolar lavage fluid of CF mice homozygous for the F508 del mutation, GSTM1 protein levels were undetectable after AZM treatment. The association between increased GST expression and activity, together with its reversal by AZM treatment in vitro and in vivo, suggest novel antioxidant properties for this drug. The issue whether decreased GST activity may directly concur to anti-inflammatory properties of AZM or is rather a marker of the oxidative status of CF cells will require additional studies.
阿奇霉素（AZM）的抗炎特性被认为是其对囊性纤维化（CF）患者产生临床有益效果的可能机制。囊性纤维化跨膜调节蛋白（CFTR）缺陷细胞中谷胱甘肽（GSH）转运的改变会导致氧化应激的发生，最终诱导谷胱甘肽S-转移酶（GST）活性。本研究旨在验证AZM对体外和体内CF气道细胞中GST活性和表达的影响。暴露于AZM可显著降低IB3-1细胞中GSTT1和GSTM1 mRNA及蛋白表达，使其水平恢复到非CF C38细胞中的水平，而C38细胞中γ-谷氨酰转移酶（GGT）活性水平也低于IB3-1细胞。在另一种CF细胞系2CFSMEo-中，AZM使GSTT1和GSTM1 mRNA水平降低了45%。AZM分别使IB3-1和2CFSMEo-细胞中的GST活性降低了约25%和40%。GSTP1在所有CF和非CF细胞中的表达相似，且不受AZM影响。抗炎细胞因子IL-10以相似水平下调GST活性，支持了GST抑制与AZM抗炎特性之间的联系。在F508 del突变纯合的CF小鼠的支气管肺泡灌洗液中，AZM治疗后未检测到GSTM1蛋白水平。GST表达和活性增加以及AZM在体外和体内治疗后的逆转之间的关联，提示了该药物具有新的抗氧化特性。GST活性降低是否直接有助于AZM的抗炎特性，还是仅仅是CF细胞氧化状态的一个标志物，这一问题还需要进一步研究。
