Division of Physiology, Taiwan Livestock Research Institute, Council of Agriculture, Tainan, Taiwan.
Theriogenology. 2010 Feb;73(3):367-82. doi: 10.1016/j.theriogenology.2009.09.020. Epub 2009 Dec 1.
Downstream effects of prostaglandin-D synthetase (PGDS) in a primary culture of chicken (Gallus gallus) anterior pituitary cells were investigated to study how PGDS regulated laying in hens. Either PGDS downstream metabolite, PGD(2) or PGJ(2), elevated LHB mRNA and LHB protein levels in dose- and time-dependent manners, and treatment with arachidonic acid (1 microM) alone upregulated 15-deoxy-Delta(12,14)-PGJ(2) (15-d-PGJ(2); derived from PGJ(2))/PGJ(2), LHB mRNA, and LHB protein levels (P<0.05) in the primary culture of chicken pituitary anterior cells. Transfection of the plasmid Enhanced Green Fluorescent Protein-PGDS plasmid into these cells in medium containing 1 microM arachidonic acid additionally increased 15-d-PGJ(2)/PGJ(2), LHB mRNA, and LHB protein levels (P<0.05). In the hypothalamus/pituitary gland of laying hens, there was a high correlation (r=0.64; P<0.05) between PGDS and the peroxisome proliferator-activated receptor A (PPARA) mRNA level in a high egg production strain, the L2 Taiwan country chickens. In commercial Single-Comb White Leghorn layers, there were high correlation coefficients between PGDS and PPARA (r=0.65; P<0.05) and between PGDS and PPARG (r=0.67; P<0.01) mRNA levels. A broad-range PPARs agonist, GW9578 (5 to 500 nM), enhanced LHB mRNA and LHB protein levels (P<0.05). The PPARA-specific (GW6471) and PPARG-specific (T0070907) antagonists suppressed endogenous LHB mRNA and LHB protein levels (P<0.05); in addition, both antagonists attenuated arachidonic acid-induced LHB mRNA levels (P<0.05) and PGDS-induced (in the presence of 1 microM arachidonic acid) LHB mRNA and LHB protein (P<0.05) levels in the primary culture of chicken anterior pituitary cells. Higher LHB mRNA/LHB protein ratios in PGD(2)-, PGJ(2)-, arachidonic acid-, PGDS-, and GW9578-induced as well as GW6471- and T0070907-suppressed anterior pituitary cells suggested that LHB transcription occurred before translation. In conclusion, PGDS induced LHB transcription and subsequent translation via the PPAR signaling pathway.
研究了前列腺素 D 合酶（PGDS）在鸡（Gallus gallus）前垂体细胞原代培养中的下游效应，以研究 PGDS 如何调节母鸡的产蛋。PGDS 的下游代谢产物 PGD（2）或 PGJ（2）以剂量和时间依赖的方式升高 LHB mRNA 和 LHB 蛋白水平，而单独用花生四烯酸（1μM）处理可上调 15-脱氧-Delta（12,14）-PGJ（2）（15-d-PGJ（2）；来自 PGJ（2））/PGJ（2）、LHB mRNA 和 LHB 蛋白水平（P<0.05）在鸡垂体前细胞原代培养中。在含有 1μM 花生四烯酸的培养基中，将质粒增强型绿色荧光蛋白-PGDS 质粒转染到这些细胞中，还可额外增加 15-d-PGJ（2）/PGJ（2）、LHB mRNA 和 LHB 蛋白水平（P<0.05）。在高产蛋鸡系 L2 台湾土鸡的下丘脑/垂体中，PGDS 与过氧化物酶体增殖物激活受体 A（PPARA）mRNA 水平之间存在高度相关性（r=0.64；P<0.05）。在商业单冠白来航鸡中，PGDS 与 PPARA（r=0.65；P<0.05）和 PGDS 与 PPARG（r=0.67；P<0.01）mRNA 水平之间存在高度相关系数。广泛的 PPAR 激动剂 GW9578（5 至 500 nM）可增强 LHB mRNA 和 LHB 蛋白水平（P<0.05）。PPARA 特异性（GW6471）和 PPARG 特异性（T0070907）拮抗剂抑制内源性 LHB mRNA 和 LHB 蛋白水平（P<0.05）；此外，两种拮抗剂均抑制花生四烯酸诱导的 LHB mRNA 水平（P<0.05）和 PGDS 诱导的（在 1μM 花生四烯酸存在下）LHB mRNA 和 LHB 蛋白（P<0.05）在鸡前垂体细胞原代培养中。PGD（2）、PGJ（2）、花生四烯酸、PGDS 和 GW9578 诱导以及 GW6471 和 T0070907 抑制的前垂体细胞中 LHB mRNA/LHB 蛋白比值较高，表明 LHB 转录发生在翻译之前。总之，PGDS 通过 PPAR 信号通路诱导 LHB 转录和随后的翻译。
