Hoskins Emily C, Halloran Katherine M, Stenhouse Claire, Moses Robyn M, Dunlap Kathrin A, Satterfield Michael C, Seo Heewon, Johnson Gregory A, Wu Guoyao, Bazer Fuller W
Departments of Animal Science, Texas A&M University, College Station, TX, 77843-2471, USA.
Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, 77843, USA.
J Anim Sci Biotechnol. 2021 Mar 5;12(1):39. doi: 10.1186/s40104-021-00554-6.
Administration of exogenous progesterone (P4) to ewes during the pre-implantation period advances conceptus development and implantation. This study determined effects of exogenous P4 on transport of select nutrients and pathways that enhance conceptus development. Pregnant ewes (n = 38) were treated with either 25 mg P4 in 1 mL corn oil (P4, n = 18) or 1 mL corn oil alone (CO, n = 20) from day 1.5 through day 8 of pregnancy and hysterectomized on either day 9 or day 12 of pregnancy. Endometrial expression of genes encoding enzymes for synthesis of polyamines, transporters of glucose, arginine, and glycine, as well as progestamedins was determined by RT-qPCR.
On day 12 of pregnancy, conceptuses from P4-treated ewes had elongated while those from CO-treated ewes were spherical. The mRNA expression of AZIN2, an arginine decarboxylase, was lower in endometria of P4-treated than CO-treated ewes on day 9 of pregnancy. Expression of FGF10, a progestamedin, was greater in endometria of CO and P4-treated ewes on day 12 of gestation in addition to P4-treated ewes necropsied on day 9 of gestation. Treatment with P4 down-regulated endometrial expression of amino acid transporter SLC1A4 on day 12 of pregnancy.
Results indicated that administration of exogenous P4 during the pre-implantation period advanced the expression of FGF10, which may accelerate proliferation of trophectoderm cells, but also was correlated with decreased expression of glycine and serine transporters and polyamine synthesis enzyme AZIN2. Further research with increased sample sizes may determine how differential expression affects endometrial functions and potentially embryonic loss.
在母羊植入前阶段给予外源性孕酮（P4）可促进胚胎发育和着床。本研究确定了外源性P4对特定营养物质转运及促进胚胎发育途径的影响。从妊娠第1.5天至第8天，对38只怀孕母羊进行处理，其中18只母羊注射1 mL玉米油中的25 mg P4（P4组），20只母羊仅注射1 mL玉米油（玉米油组，CO），并在妊娠第9天或第12天进行子宫切除。通过逆转录定量聚合酶链反应（RT-qPCR）测定子宫内膜中编码多胺合成酶、葡萄糖、精氨酸和甘氨酸转运蛋白以及孕激素介质的基因表达。
在妊娠第12天，P4处理母羊的胚胎已伸长，而CO处理母羊的胚胎呈球形。在妊娠第9天，P4处理母羊的子宫内膜中，精氨酸脱羧酶AZIN2的mRNA表达低于CO处理母羊。除了在妊娠第9天进行尸检的P4处理母羊外，在妊娠第12天，CO和P4处理母羊的子宫内膜中孕激素介质FGF10的表达更高。在妊娠第12天，P4处理下调了子宫内膜中氨基酸转运蛋白SLC1A4的表达。
结果表明，在植入前阶段给予外源性P4可促进FGF10的表达，这可能加速滋养外胚层细胞的增殖，但也与甘氨酸和丝氨酸转运蛋白以及多胺合成酶AZIN2的表达降低有关。进一步增加样本量的研究可能会确定差异表达如何影响子宫内膜功能以及潜在的胚胎丢失。
