Ao Zheng, Wu Zhimin, Hu Guangling, Gong Ting, Zhang Caizai, Yang Zhenqing, Zhang Yiyu
Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, College of Animal Science, Guizhou University, Guiyang, 550025, China; Guizhou Provincial Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science, Guizhou University, Guiyang, 550025, China.
Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, College of Animal Science, Guizhou University, Guiyang, 550025, China; Guizhou Provincial Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science, Guizhou University, Guiyang, 550025, China.
Theriogenology. 2024 Mar 1;216:127-136. doi: 10.1016/j.theriogenology.2023.12.035. Epub 2023 Dec 31.
Placental dysfunction is considered as one of the main etiologies of fetal intrauterine growth retardation (IUGR). MicroRNAs (miRNAs) have been demonstrated to be a vital epigenetic modification involved in regulating the placental function and pregnancy outcomes in mammals. However, the mechanisms underlying placenta-specific miRNAs involved in the occurrence and development of pig IUGR remain unclear. In this work, we compared the placental morphologies of piglets with IUGR and normal birth weight (NBW) by using histomorphological analysis and performed a miRNA-mRNA integrative analysis of the gene expression profiles of IUGR and NBW placentas through RNA sequencing. We also investigated the role of differentially expressed ssc-miR-339-5p/GRIK3 through an in vitro experiment on porcine trophoblast cells (PTr2). IUGR piglets had significantly lower birth weight, placental weight, placental efficiency, and placental villus and capillary densities compared with the NBW piglets (P < 0.05). A total of 81 differentially expressed miRNAs and 726 differentially expressed genes in the placentas were screened out between the IUGR and NBW groups. The miRNA-mRNA interaction networks revealed the key core miRNA (ssc-miR-339-5p) and its corresponding target genes. Subsequently, we found that upregulation of ssc-miR-339-5p significantly inhibited the migration and proliferation of PTr2 cells (P < 0.05). The dual-luciferase reporter system showed that GRIK3 was the target gene of ssc-miR-339-5p, and the transcription level of GRIK3 may be negatively regulated by ssc-miR-339-5p. Additionally, overexpression of ssc-miR-339-5p significantly increased (P < 0.05) the mRNA expression levels of genes involved in the cytokine-cytokine receptor interaction pathway. These results indicate that ssc-miR-339-5p may affect the migration and proliferation of trophoblast cells by regulating the expression of GRIK3 and altering the placental inflammatory response, resulting in a suboptimal morphology and function of the placenta and the development of pig IUGR.
胎盘功能障碍被认为是胎儿宫内生长受限（IUGR）的主要病因之一。微小RNA（miRNA）已被证明是一种重要的表观遗传修饰，参与调节哺乳动物的胎盘功能和妊娠结局。然而，猪IUGR发生发展过程中涉及的胎盘特异性miRNA的潜在机制仍不清楚。在本研究中，我们通过组织形态学分析比较了IUGR仔猪和正常出生体重（NBW）仔猪的胎盘形态，并通过RNA测序对IUGR和NBW胎盘的基因表达谱进行了miRNA-mRNA整合分析。我们还通过对猪滋养层细胞（PTr2）进行体外实验，研究了差异表达的ssc-miR-339-5p/GRIK3的作用。与NBW仔猪相比，IUGR仔猪的出生体重、胎盘重量、胎盘效率以及胎盘绒毛和毛细血管密度显著降低（P<0.05）。在IUGR组和NBW组之间筛选出胎盘中共81个差异表达的miRNA和726个差异表达的基因。miRNA-mRNA相互作用网络揭示了关键核心miRNA（ssc-miR-339-5p）及其相应的靶基因。随后，我们发现上调ssc-miR-339-5p可显著抑制PTr2细胞的迁移和增殖（P<0.05）。双荧光素酶报告系统显示GRIK3是ssc-miR-339-5p的靶基因，且GRIK3的转录水平可能受到ssc-miR-339-5p的负调控。此外，过表达ssc-miR-339-5p可显著增加（P<0.05）细胞因子-细胞因子受体相互作用途径相关基因的mRNA表达水平。这些结果表明，ssc-miR-339-5p可能通过调节GRIK3的表达并改变胎盘炎症反应，影响滋养层细胞的迁移和增殖，导致胎盘形态和功能欠佳以及猪IUGR的发生。
