Yang Yuan H, Aeberli Daniel, Dacumos April, Xue Jin R, Morand Eric F
Centre for Inflammatory Diseases, Department of Medicine, Monash University, Clayton, Victoria, Australia.
J Immunol. 2009 Jul 15;183(2):1435-45. doi: 10.4049/jimmunol.0804000. Epub 2009 Jun 24.
Annexin-1 (ANXA1) is a mediator of the anti-inflammatory actions of endogenous and exogenous glucocorticoids (GC). The mechanism of ANXA1 effects on cytokine production in macrophages is unknown and is here investigated in vivo and in vitro. In response to LPS administration, ANXA1(-/-) mice exhibited significantly increased serum IL-6 and TNF compared with wild-type (WT) controls. Similarly, LPS-induced IL-6 and TNF were significantly greater in ANXA1(-/-) than in WT peritoneal macrophages in vitro. In addition, deficiency of ANXA1 was associated with impairment of the inhibitory effects of dexamethasone (DEX) on LPS-induced IL-6 and TNF in macrophages. Increased LPS-induced cytokine expression in the absence of ANXA1 was accompanied by significantly increased LPS-induced activation of ERK and JNK MAPK and was abrogated by inhibition of either of these pathways. No differences in GC effects on MAPK or MAPK phosphatase 1 were observed in ANXA1(-/-) cells. In contrast, GC-induced expression of the regulatory protein GILZ was significantly reduced in ANXA1(-/-) cells by silencing of ANXA1 in WT cells and in macrophages of ANXA1(-/-) mice in vivo. GC-induced GILZ expression and GC inhibition of NF-kappaB activation were restored by expression of ANXA1 in ANXA1(-/-) cells, and GILZ overexpression in ANXA1(-/-) macrophages reduced ERK MAPK phosphorylation and restored sensitivity of cytokine expression and NF-kappaB activation to GC. These data confirm ANXA1 as a key inhibitor of macrophage cytokine expression and identify GILZ as a previously unrecognized mechanism of the anti-inflammatory effects of ANXA1.
膜联蛋白-1（ANXA1）是内源性和外源性糖皮质激素（GC）抗炎作用的介质。ANXA1对巨噬细胞细胞因子产生的影响机制尚不清楚，本文对此进行了体内和体外研究。与野生型（WT）对照相比，给予脂多糖（LPS）后，ANXA1基因敲除（-/-）小鼠的血清白细胞介素-6（IL-6）和肿瘤坏死因子（TNF）显著增加。同样，在体外，LPS诱导的IL-6和TNF在ANXA1（-/-）腹膜巨噬细胞中比在WT腹膜巨噬细胞中显著更高。此外，ANXA1缺乏与地塞米松（DEX）对巨噬细胞中LPS诱导的IL-6和TNF的抑制作用受损有关。在缺乏ANXA1的情况下，LPS诱导的细胞因子表达增加伴随着LPS诱导的细胞外信号调节激酶（ERK）和c-Jun氨基末端激酶（JNK）丝裂原活化蛋白激酶（MAPK）的显著激活，并且通过抑制这些途径中的任何一条都可以消除这种激活。在ANXA1（-/-）细胞中未观察到GC对MAPK或MAPK磷酸酶1的影响有差异。相反，通过在WT细胞中沉默ANXA1以及在体内ANXA1（-/-）小鼠的巨噬细胞中，GC诱导的调节蛋白糖皮质激素诱导亮氨酸拉链蛋白（GILZ）的表达在ANXA1（-/-）细胞中显著降低。通过在ANXA1（-/-）细胞中表达ANXA1，恢复了GC诱导的GILZ表达以及GC对核因子κB（NF-κB）激活的抑制作用，并且在ANXA1（-/-）巨噬细胞中过表达GILZ降低了ERK MAPK磷酸化，并恢复了细胞因子表达和NF-κB激活对GC的敏感性。这些数据证实ANXA1是巨噬细胞细胞因子表达的关键抑制剂，并确定GILZ是ANXA1抗炎作用的一种先前未被认识的机制。
