College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountain Region, College of Animal Science, Guizhou University, Guiyang, China.
Front Endocrinol (Lausanne). 2024 May 1;15:1356914. doi: 10.3389/fendo.2024.1356914. eCollection 2024.
Nutritional deficiency occurs frequently during pregnancy and breastfeeding. Tryptophan (Trp), an essential amino acid which is critical for protein synthesis, serves as the precursor for serotonin, melatonin, and kynurenine (Kyn). The imbalance between serotonin and kynurenine pathways in Trp metabolism is closely related to inflammation and depression. This study assessed the effects of Trp deficiency on mouse early pregnancy.
Embryo implantation and decidualization were analyzed after female mice had been fed diets containing 0.2% Trp (for the control group), 0.062% Trp (for the low Trp group) and 0% Trp (for the Trp-free group) for two months. The uteri of the mice were collected on days 4, 5, and 8 of pregnancy for further analysis.
On day 8 of pregnancy, the number of implantation sites were found to be similar between the control and the low Trp groups. However, no implantation sites were detected in the Trp-free group. On day 5 of pregnancy, plane polarity- and decidualization-related molecules showed abnormal expression pattern in the Trp-free group. On day 4 of pregnancy, there was no significant difference in uterine receptivity molecules between the low-Trp group and the control group, but uterine receptivity was abnormal in the Trp-free group. At implantation sites of the Trp-free group, IDO and AHR levels were markedly elevated. This potentially increased levels of Kyn, 2-hydroxy estradiol, and 4-hydroxy estradiol to affect decidualization.
Trp-free diet may impair decidualization via the IDO-KYN-AHR pathway.
营养缺乏在妊娠和哺乳期很常见。色氨酸（Trp）是一种必需氨基酸，对蛋白质合成至关重要，它是血清素、褪黑素和犬尿氨酸（Kyn）的前体。Trp 代谢中血清素和犬尿氨酸途径之间的失衡与炎症和抑郁密切相关。本研究评估了 Trp 缺乏对小鼠早期妊娠的影响。
雌性小鼠连续两个月喂食含 0.2%Trp（对照组）、0.062%Trp（低 Trp 组）和 0%Trp（无 Trp 组）的饮食后，分析胚胎着床和蜕膜化。妊娠第 4、5 和 8 天收集小鼠子宫进行进一步分析。
妊娠第 8 天，对照组和低 Trp 组的着床点数量相似。然而，无 Trp 组未检测到着床点。妊娠第 5 天，无 Trp 组平面极性和蜕膜化相关分子的表达模式异常。妊娠第 4 天，低 Trp 组和对照组的子宫接受性分子无显著差异，但无 Trp 组的子宫接受性异常。在无 Trp 组的着床点，IDO 和 AHR 水平明显升高。这可能增加了犬尿氨酸、2-羟基雌二醇和 4-羟基雌二醇的水平，从而影响蜕膜化。
无 Trp 饮食可能通过 IDO-KYN-AHR 途径损害蜕膜化。
