Lappas Martha
Mercy Perinatal Research CentreMercy Hospital for Women, Heidelberg, Victoria, AustraliaObstetricsNutrition and Endocrinology Group, Department of Obstetrics and Gynaecology, Mercy Hospital for Women, University of Melbourne, Level 4/163 Studley Road, Heidelberg 3084, Victoria, Australia Mercy Perinatal Research CentreMercy Hospital for Women, Heidelberg, Victoria, AustraliaObstetricsNutrition and Endocrinology Group, Department of Obstetrics and Gynaecology, Mercy Hospital for Women, University of Melbourne, Level 4/163 Studley Road, Heidelberg 3084, Victoria, Australia
Reproduction. 2016 Apr;151(4):411-20. doi: 10.1530/REP-15-0607. Epub 2016 Jan 25.
Inflammation plays a central role in the terminal process of human labour and delivery, including myometrial contractions. RAF1 proto-oncogene serine/threonine-protein kinase (RAF1) can activate ERK (official gene symbol MAPK1) and/or nuclear factor-kappa B (NF-κB) to regulate genes involved in inflammation. There are, however, no studies on the role of RAF1 in the processes of human labour and delivery. Thus, the aims of this study were to determine the effect of i) human labour and pro-inflammatory cytokines interleukin 1 beta (IL1B) and tumour necrosis factor (TNF) alpha on RAF1 protein expression in myometrium and ii) siRNA knockdown of RAF1 on pro-inflammatory and pro-labour mediators in human myometrial primary cells. Term labour was associated with an increase in RAF1 protein expression. Furthermore, RAF1 protein expression was increased in myometrial cells treated with IL1B and TNF, two likely factors contributing to preterm birth. Knockdown of RAF1 by siRNA in primary myometrial cells significantly decreased IL1B- and TNF-induced IL1A, IL1B, IL6, (C-X-C motif) ligand 8 (CXCL8)and chemokine (C-C motif) ligand 2 (CCL2) mRNA abundance and IL6, IL8 and CCL2; prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA levels and prostaglandin PGF2 α release; and NF-κB activation. Furthermore, RAF1 knockdown was associated with decreased activation of ERK in the presence of IL1B but not TNF. Concordantly, the ERK inhibitor U0126 significantly decreased IL1B-induced IL6, CXCL8, CCL2 and PTGS2 mRNA abundance; IL6, CXCL8, CCL2 and PGF2 α release; and NF-κB activation. In conclusion, IL1B induces the expression and secretion of pro-labour mediators through the RAF1-MAPK1-NF-κB signalling pathway. TNF, on the other hand, regulates pro-labour mediators through the RAF1-NF-κB signalling pathway via an MAPK1-independent mechanism.
炎症在人类分娩的终末过程中起着核心作用，包括子宫肌层收缩。RAF1原癌基因丝氨酸/苏氨酸蛋白激酶（RAF1）可激活细胞外信号调节激酶（ERK，官方基因符号MAPK1）和/或核因子-κB（NF-κB），以调节参与炎症的基因。然而，目前尚无关于RAF1在人类分娩过程中作用的研究。因此，本研究的目的是确定：i）人类分娩以及促炎细胞因子白细胞介素1β（IL1B）和肿瘤坏死因子（TNF）α对子宫肌层中RAF1蛋白表达的影响；ii）RNA干扰（siRNA）敲低RAF1对人子宫肌层原代细胞中促炎和促分娩介质的影响。足月分娩与RAF1蛋白表达增加有关。此外，在用IL1B和TNF处理的子宫肌层细胞中，RAF1蛋白表达增加，这两种细胞因子可能是导致早产的因素。在原代子宫肌层细胞中，通过siRNA敲低RAF1可显著降低IL1B和TNF诱导的白细胞介素1α（IL1A）、IL1B、白细胞介素6（IL6）、（C-X-C基序）配体8（CXCL8）和趋化因子（C-C基序）配体2（CCL2）的mRNA丰度，以及IL6、IL8和CCL2；前列腺素内过氧化物合酶2（PTGS2）的mRNA水平和前列腺素PGF2α的释放；以及NF-κB的激活。此外，在存在IL1B但不存在TNF的情况下，敲低RAF1与ERK激活的降低有关。同样，ERK抑制剂U0126可显著降低IL1B诱导的IL6、CXCL8、CCL2和PTGS2的mRNA丰度；IL6、CXCL8、CCL,2和PGF2α的释放；以及NF-κB的激活。总之，IL1B通过RAF1-MAPK1-NF-κB信号通路诱导促分娩介质的表达和分泌。另一方面，TNF通过RAF1-NF-κB信号通路，经由一种不依赖MAPK1的机制调节促分娩介质。
