尽管宫内生长受限（IUGR）条件下胎儿肝脏的脂质代谢已被广泛研究，但母体营养不良对胎儿肝脏脂质代谢、脂毒性损伤和发育异常的影响仍知之甚少。因此，本研究利用转录组分析探讨了母体营养不良对IUGR羊胎儿肝脏脂质代谢紊乱、脂毒性损伤和发育异常的影响。将 17 只单胎母羊在妊娠第 90 天随机分为三组：对照组（CG；0.63 MJ 代谢能/体重 (ME/BW)0.75/天，n = 5）、母体营养不良组 1（MU1；0.33） MJ ME/BW0.75/天，n = 6) 和孕产妇营养不良第 2 组 (MU2；0.20 MJ ME/BW0.75/天，n = 6)。胎儿在​​怀孕第 130 天被安乐死并康复。 MU1和MU2组母血（P < 0.01）、胎儿血液（P < 0.01）和胎儿肝脏（P < 0.05）中游离脂肪酸（FFA）水平升高，但胎儿肝甘油三酯（TG）水平升高与CG相比，MU2组的β-羟基丁酸水平（P<0.01）以及MU1和MU2组的β-羟基丁酸水平（P<0.01）降低。在 MU1 和 MU2 胎儿中观察到严重的炎症细胞浸润和非酒精性脂肪肝疾病活动评分增加（P < 0.01）。 MU1和MU2组胎儿肝脏中胎儿肝网状纤维和胶原纤维逐渐沉积，MU2胎儿出现明显的肝纤维化（P < 0.05）。基因集富集分析表明，与对照组相比，两个 MU 组中涉及脂质积累和 FFA β 氧化的基因均下调。 MU1 (P < 0.05) 和 MU2 (P < 0.01) 胎儿中 β-氧化调节剂乙酰辅酶 A 乙酰转移酶 1 和 TCA 调节剂异柠檬酸脱氢酶的胎儿肝脏 mRNA 表达降低，长链 mRNA 表达下调在 MU2 胎儿中观察到脂肪酸 CoA 连接酶 1（P < 0.05）和 3-磷酸甘油酰基转移酶（P < 0.01）。使用 RNA 测序鉴定了 MU1 与 CG（360 DEG）和 MU2 与 CG（746 DEG）中的差异表达基因（DEG）。对 MU1 与 CG 和 MU2 与 CG 之间 231 个相交 DEG 的生物信息学分析表明，中性粒细胞胞外陷阱 (NET) 被诱导，并在 IUGR 绵羊胎儿肝损伤中发挥核心作用。 MU1 和 MU2 组中母血髓过氧化物酶 (MPO) 水平升高 (P < 0.01)，胎儿肝脏切片中 NE (Elane) 阳性区域 (P < 0.05) 和胎儿肝脏 MPO 蛋白表达升高 (P < 0.01) ;然而，MU1 组胎膜（P < 0.01）和胎儿血液（P < 0.05）中 MPO 水平降低，MU2 组母胎胎盘和胎儿血液中 MPO 水平降低（P < 0.01）。对MU1与CG（129°）和MU2与CG（515°）之间相交DEG的基因表达趋势进行分析，进一步揭示30个枢纽基因是G2/M细胞周期的重要调节因子，所有这些都与肝细胞癌相关。 MU1组（P<0.05）和MU2组（P<0.01）胎肝G0/G1期细胞减少，而MU1组和MU2组G2/M期细胞增多（P<0.01）。 MU1和MU2组中上调的枢纽基因和胎肝蛋白表达的代表母体胚胎亮氨酸拉链激酶和胞质分裂1蛋白调节因子1逐渐增强（P < 0.01），MU2组拓扑异构酶II α蛋白表达逐渐增强（P < 0.01）。 < 0.05)，如预期。这些结果表明，IUGR 绵羊胎肝中 FFA 超载、严重脂毒性损伤和 NET 被诱导，并且 G2/M 细胞周期的促病调节因子上调。这些发现为了解肝脏脂质代谢受损和发育异常的发病机制以及因母亲营养不良导致的IUGR产后肝病的分子起源提供了新的见解。这些信息可以支持新治疗策略的开发。版权所有 © 2024 Elsevier Inc. 保留所有权利。

Although lipid metabolism in fetal livers under intrauterine growth restriction (IUGR) conditions has been widely studied, the implications of maternal undernutrition on fetal hepatic lipid metabolism, lipotoxic injury, and abnormal development remain largely unknown. Therefore, this study investigated the effects of maternal undernutrition on disordered hepatic lipid metabolism, lipotoxic injury, and abnormal development in IUGR sheep fetuses using transcriptome analysis. Seventeen singleton ewes were randomly divided into three groups on day 90 of pregnancy: a control group (CG; 0.63 MJ metabolic energy/body weight (ME/BW)0.75/day, n = 5), maternal undernutrition group 1 (MU1; 0.33 MJ ME/BW0.75/day, n = 6), and maternal undernutrition group 2 (MU2; 0.20 MJ ME/BW0.75/day, n = 6). The fetuses were euthanized and recovered on day 130 of pregnancy. The levels of free fatty acids (FFA) in maternal blood (P < 0.01), fetal blood (P < 0.01), and fetal livers (P < 0.05) were increased in the MU1 and MU2 groups, but fetal hepatic triglyceride (TG) levels in the MU2 group (P < 0.01) and β-hydroxybutyrate levels in the MU1 and MU2 groups (P < 0.01) were decreased compared to the CG. Severe inflammatory cell infiltration and increased non-alcoholic fatty liver disease activity scores were observed in MU1 and MU2 fetuses (P < 0.01). Progressive deposition of fetal hepatic reticular fibers and collagen fibers in the fetal livers of the MU1 and MU2 groups and significant hepatic fibrosis were observed in the MU2 fetuses (P < 0.05). Gene set enrichment analysis showed that genes involved in lipid accumulation and FFA beta oxidation were downregulated in both MU groups compared to those in the controls. The fetal liver mRNA expression of the β-oxidation regulator, acetyl-CoA acetyltransferase 1, and the TCA regulator, isocitrate dehydrogenase were reduced in MU1 (P < 0.05) and MU2 (P < 0.01) fetuses, and downregulated mRNA expression of long chain fatty acid CoA ligase 1 (P < 0.05) and glycerol-3-phosphate acyltransferase (P < 0.01) was observed in MU2 fetuses. Differentially expressed genes (DEGs) in MU1 versus CG (360 DEGs) and MU2 versus CG (746 DEGs) were identified using RNA sequencing. Bioinformatics analyses of the 231 intersecting DEGs between MU1 versus CG and MU2 versus CG indicated that neutrophil extracellular traps (NETs) were induced and played a central role in fetal hepatic injury in IUGR sheep. Increased maternal blood myeloperoxidase (MPO) levels (P < 0.01), NE (Elane)-positive areas in fetal liver sections (P < 0.05), and fetal liver MPO protein expression (P < 0.01) were found in the MU1 and MU2 groups; however, MPO levels were reduced in the fetal membrane (P < 0.01) and fetal blood (P < 0.05) in the MU1 group, and in the maternal-fetal placenta and fetal blood in the MU2 group (P < 0.01). Analysis of gene expression trends in the intersecting DEGs between MU1 versus CG (129 DEGs) and MU2 versus CG (515 DEGs) further revealed that 30 hub genes were essential regulators of the G2/M cell cycle, all of which were associated with hepatocellular carcinoma. G0/G1 phase cells of the fetal liver were reduced in the MU1 (P < 0.05) and MU2 (P < 0.01) groups, whereas G2/M phase cells were elevated in the MU1 and MU2 groups (P < 0.01). The representatives of upregulated hub genes and fetal liver protein expression of maternal embryonic leucine zipper kinase and protein regulator of cytokinesis 1 were progressively enhanced in the MU1 and MU2 groups (P < 0.01), and topoisomerase II alpha protein expression in the MU2 group (P < 0.05), as expected. These results indicate that FFA overload, severe lipotoxic injury, and NETs were induced, and disease-promoting regulators of the G2/M cell cycle were upregulated in the fetal liver of IUGR sheep. These findings provide new insights into the pathogenesis of impaired hepatic lipid metabolism and abnormal development and the molecular origin of post-natal liver disease in IUGR due to maternal undernutrition. This information can support the development of new therapeutic strategies.Copyright © 2024 Elsevier Inc. All rights reserved.