Tryptophan regulates the expression of IGFBP1 in bovine endometrial epithelial cells in vitro via the TDO2-AHR pathway

• Published in: BMC veterinary research Vol. 20; no. 1; p. 390
• Main Authors: Wang, Peng-Chao, Liu, Ze-Kun, Li, Jia-Rong, Zhao, Zi-Hui, Chang, Qian-Wen, Guo, Xiao-Min, Jin, Lin, Hu, Yong-Ting, Yang, Zhenshan
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 04.09.2024; BioMed Central; BMC
• Subjects: Amino acids; Animals; aryl hydrocarbon receptors; Basic Medicine; Binding proteins; Bovine; Brucellosis in cattle; Cattle; Cell and Molecular Biology; Cell- och molekylärbiologi; conceptus; Cyclooxygenase 2 - genetics; Cyclooxygenase 2 - metabolism; Cyclooxygenase-2; Dinoprostone - metabolism; Endometrium; Endometrium - drug effects; Endometrium - metabolism; Enzymes; Epithelial cells; Epithelial Cells - drug effects; Epithelial Cells - metabolism; epithelium; Female; Fertility; gene expression regulation; Gene Expression Regulation - drug effects; Genes; insulin; Insulin-Like Growth Factor Binding Protein 1 - genetics; Insulin-Like Growth Factor Binding Protein 1 - metabolism; Insulin-like growth factor-binding protein 1; Kynurenine; Kynurenine - metabolism; Kynurenine - pharmacology; kynurenine pathway; Ligands; Medical and Health Sciences; Medicin och hälsovetenskap; Medicinska och farmaceutiska grundvetenskaper; Metabolism; Metabolites; Oxidases; PGE2; Physiological aspects; Pregnancy; Prostaglandin E2; prostaglandin synthase; prostaglandins; Protein synthesis; quantitative polymerase chain reaction; Receptors, Aryl Hydrocarbon - genetics; Receptors, Aryl Hydrocarbon - metabolism; Signal Transduction - drug effects; Transcription factors; Tryptophan; Tryptophan - metabolism; Tryptophan - pharmacology; Tryptophan 2,3-dioxygenase; Tryptophan hydroxylase; Tryptophan Oxygenase - genetics; Tryptophan Oxygenase - metabolism; Uterine receptivity; Uterus; Western blotting; China; Kynurenine; Tryptophan; PGE2; Bovine; Uterine receptivity
• ISSN: 1746-6148; 1746-6148
• DOI: 10.1186/s12917-024-04191-9

This study aimed to identify the roles of L-tryptophan (Trp) and its rate-limiting enzymes on the receptivity of bovine endometrial epithelial cells. Real-time PCR was conducted to analyze the differential expression of genes between different groups of bovine endometrial epithelial cells. Western blot was performed to detect Cyclooxygenase-2 (COX2) expression after treatment with Trp or kynurenine (the main metabolites of Trp). The kynurenine assay was used to examine if Trp or prostaglandin E2 (PGE2) can increase the production of kynurenine in the bovine endometrial epithelial cells. Trp significantly stimulates insulin growth factor binding protein 1 (IGFBP1) expression, a common endometrial marker of conceptus elongation and uterus receptivity for ruminants. When bovine endometrial epithelial cells are treated with Trp, tryptophan hydroxylase-1 remains unchanged, but tryptophan 2,3-dioxygenase 2 (TDO2) is significantly increased, suggesting tryptophan is mainly metabolized through the kynurenine pathway. Kynurenine significantly stimulates IGFBP1 expression. Furthermore, Trp and kynurenine significantly increase the expression of aryl hydrocarbon receptor (AHR). CH223191, an AHR inhibitor, abrogates the induction of Trp and kynurenine on IGFBP1. PGE2 significantly induces the expression of TDO2, AHR, and IGFBP1. The regulation between Trp / kynurenine and PGE2 may be crucial for the receptivity of the bovine uterus.