Guzeloglu Aydin, Subramaniam Prem, Michel Frank, Thatcher William W
Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA.
Biol Reprod. 2004 Jul;71(1):170-6. doi: 10.1095/biolreprod.103.025411. Epub 2004 Feb 25.
A series of experiments were undertaken to examine the effects of interferon (IFN)-tau on regulation of prostaglandin H synthase (PGHS)-2 mRNA in bovine endometrial (BEND) cells as a means to elucidate the actions of IFN-tau to maintain pregnancy. The objective was to determine if IFN-tau mediates posttranscriptional regulation of PGHS-2 mRNA. Cells were treated with phorbol 12,13-dibutyrate (PdBu) for 3 h to induce PGHS-2 mRNA expression. Actinomycin D (0 or 1 microg/ml) or the p38 mitogen-activated protein kinase (MAPK) inhibitor, SB203580 (1 microM), were added at 3 h, followed by addition of IFN-tau (0 or 50 ng/ml) at 3.5 h and extraction of RNA at 4.5 h. The concentrations of PGHS-2 mRNA were stable between 3 and 4.5 h regardless of actinomycin D. Simultaneous treatment of PdBu-treated cells with actinomycin D and SB203580 (1 microM) decreased PGHS-2 mRNA. Addition of IFN-tau (50 ng/ml) reduced PGHS-2 mRNA, which was not observed when actinomycin D was present. Concurrent treatments of cells with SB203580 and IFN-tau (5 ng/ml) decreased concentrations of PGHS-2 mRNA in an additive manner. Although IFN-tau reduced PGHS-2 mRNA concentrations, phosphorylation of p38 MAPK was induced by IFN-tau, PdBu, and PdBu combined with IFN-tau after 10 min of treatment. Both the p38 MAPK inhibitor and IFN-tau decreased prostaglandin F(2alpha) secretion, and decreases were additive when the two were given together. In summary, activation of p38 MAPK by PdBu is required for continued presence of PGHS-2 mRNA and secretion of prostaglandin F(2alpha) in BEND cells. Interferon-tau mediates a transcription-dependent mechanism, which induces degradation of PGHS-2 mRNA. However, the consequences of an IFN-tau-induced activation of p38 MAPK warrant further investigation, because inhibition of p38 MAPK caused a degradation of PGHS-2 mRNA.
进行了一系列实验，以研究干扰素（IFN）-τ对牛子宫内膜（BEND）细胞中前列腺素H合酶（PGHS）-2 mRNA调节的影响，以此阐明IFN-τ维持妊娠的作用机制。目的是确定IFN-τ是否介导PGHS-2 mRNA的转录后调控。用佛波酯12,13-二丁酸酯（PdBu）处理细胞3小时以诱导PGHS-2 mRNA表达。在3小时时加入放线菌素D（0或1微克/毫升）或p38丝裂原活化蛋白激酶（MAPK）抑制剂SB203580（1微摩尔），然后在3.5小时加入IFN-τ（0或50纳克/毫升），并在4.5小时提取RNA。无论有无放线菌素D，PGHS-2 mRNA的浓度在3至4.5小时之间保持稳定。用放线菌素D和SB203580（1微摩尔）同时处理经PdBu处理的细胞可降低PGHS-2 mRNA水平。加入IFN-τ（50纳克/毫升）可降低PGHS-2 mRNA水平，而当存在放线菌素D时未观察到这种现象。用SB203580和IFN-τ（5纳克/毫升）同时处理细胞，可使PGHS-2 mRNA浓度呈相加性降低。尽管IFN-τ降低了PGHS-2 mRNA浓度，但在处理10分钟后，IFN-τ、PdBu以及PdBu与IFN-τ联合使用均可诱导p38 MAPK磷酸化。p38 MAPK抑制剂和IFN-τ均可降低前列腺素F2α分泌，二者同时使用时降低作用呈相加性。总之，PdBu激活p38 MAPK是BEND细胞中PGHS-2 mRNA持续存在及前列腺素F2α分泌所必需的。IFN-τ介导一种转录依赖性机制，可诱导PGHS-2 mRNA降解。然而，IFN-τ诱导p38 MAPK激活的后果值得进一步研究，因为抑制p38 MAPK会导致PGHS-2 mRNA降解。
