Department of Reproductive Immunology and Pathology, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-747 Tuwima 10 St ., 10 -, 748, Olsztyn, Poland.
BMC Vet Res. 2019 Nov 21;15(1):416. doi: 10.1186/s12917-019-2167-3.
Prostaglandin F (PGF) may differentially affect viability of luteal cells by inducing either proliferation or cell death (via apoptosis or necroptosis). The diverse effects of PGF may depend on its local vs. systemic actions. In our study, we determined changes in expression of genes related to: (i) apoptosis: caspase (CASP) 3, CASP8, BCL2 associated X (BAX), B-cell lymphoma 2 (BCL2) and (ii) necroptosis: receptor-interacting protein kinase (RIPK) 1, RIPK3, cylindromatosis (CYLD), and mixed lineage kinase domain-like (MLKL) in the early and mid-stage corpus luteum (CL) that accompany local (intra-CL) vs. systemic (i.m.) analogue of PGF (aPGF) actions. Cows at day 4 (n = 24) or day 10 (n = 24) of the estrous cycle were treated by injections as follows: (1) systemic saline, (2) systemic aPGF (25 mg; Dinoprost), (3) local saline, (4) local aPGF (2.5 mg; Dinoprost). After 4 h, CLs were collected by ovariectomy. Expression levels of mRNA and protein were investigated by RT-q PCR, Western blotting and immunohistochemistry, respectively.
We found that local and systemic administration of aPGF in the early-stage CL resulted in decreased expression of CASP3 (P < 0.01), but CASP8 mRNA expression was up-regulated (P < 0.05). However, the expression of CASP3 was up-regulated after local aPGF treatment in the middle-stage CL, whereas systemic aPGF administration increased both CASP3 and CASP8 expression (P < 0.01). Moreover, we observed that both local and systemic aPGF injections increased RIPK1, RIPK3 and MLKL expression in the middle-stage CL (P < 0.05) while CYLD expression was markedly higher after i.m. aPGF injections (P < 0.001). Moreover, we investigated the localization of necroptotic factors (RIPK1, RIPK3, CYLD and MLKL) in bovine CL tissue after local and systemic aPGF injections in the bovine CL.
Our results demonstrated for the first time that genes related to cell death pathways exhibit stage-specific responses to PGF administration depending on its local or systemic actions. Locally-acting PGF plays a luteoprotective role by inhibiting apoptosis and necroptosis in the early CL. Necroptosis is a potent mechanism responsible for structural CL regression during PGF-induced luteolysis in cattle.
前列腺素 F（PGF）可能通过诱导增殖或细胞死亡（通过细胞凋亡或坏死）来对黄体细胞的活力产生不同的影响（通过细胞凋亡或坏死）。PGF 的不同作用可能取决于其局部作用与全身作用。在我们的研究中，我们确定了与以下方面相关的基因表达的变化：（i）细胞凋亡：半胱天冬酶（CASP）3、CASP8、B 细胞淋巴瘤 2 相关 X（BAX）、B 细胞淋巴瘤 2（BCL2）和（ii）坏死：受体相互作用蛋白激酶（RIPK）1、RIPK3、圆柱瘤（CYLD）和混合谱系激酶结构域样（MLKL）在黄体早期和中期（CL）中的变化伴随着局部（CL 内）与全身（肌肉内）PGF 类似物（aPGF）的作用。发情周期第 4 天（n=24）或第 10 天（n=24）的奶牛接受以下注射治疗：（1）全身生理盐水，（2）全身 aPGF（25mg；dinoprost），（3）局部生理盐水，（4）局部 aPGF（2.5mg；dinoprost）。4 小时后，通过卵巢切除术收集 CL。通过 RT-qPCR、Western blotting 和免疫组织化学分别研究 mRNA 和蛋白质的表达水平。
我们发现，早期 CL 中局部和全身给予 aPGF 导致 CASP3 的表达下调（P<0.01），但 CASP8 mRNA 的表达上调（P<0.05）。然而，在中期 CL 中局部给予 aPGF 后，CASP3 的表达上调，而全身给予 aPGF 后，CASP3 和 CASP8 的表达均增加（P<0.01）。此外，我们观察到局部和全身给予 aPGF 均可增加中期 CL 中 RIPK1、RIPK3 和 MLKL 的表达（P<0.05），而肌肉内给予 aPGF 后 CYLD 的表达明显升高（P<0.001）。此外，我们还研究了局部和全身给予 aPGF 后牛 CL 组织中坏死因子（RIPK1、RIPK3、CYLD 和 MLKL）的定位。
我们的研究结果首次表明，与细胞死亡途径相关的基因对 PGF 给药的反应表现出与局部或全身作用有关的阶段特异性。局部作用的 PGF 通过在早期 CL 中抑制细胞凋亡和坏死发挥黄体保护作用。坏死是牛 PGF 诱导黄体溶解过程中导致结构 CL 退化的一种有效机制。
