Topical Area: Carotenoids and Retinoids (CARIG)
Carotenoid/retinoids status and metabolism are essential for normal placental and fetal development. Both deficiencies and excess of retinoids and some carotenoids are associated with adverse pregnancy outcomes, such as preeclampsia and preterm birth. A group of important genes involved in regulating carotenoid/retinoid metabolism and maternal to fetal transfer in human placenta. The objective of this study is to analyze (a) the expression of genes critical for regulating carotenoid/retinoid metabolism and maternal-fetal transport in human trophoblasts and (b) placental transcriptional profiles of these pathways in response to carotenoid exposure.
Human cytotrophoblasts (CTBs) were isolated from term placentas. CTB RNA was used to analyze the expression of genes involved in carotenoid/retinoid metabolism and pathways by qRT-PCT. First trimester-like trophoblasts (HTR-8/SVneo) were treated with either β-carotene or lycopene. RNAs were isolated and gene expression were analyzed by DNA microarrays.
Results : Human CTBs express retinoid metabolism and pathways-related genes, including Stra6, Lrat, Rdh5, Rdh10, Aldh1a1, Aldh1a2, Aldh1a3, Aldh8a1, Cyp26a1, and Cyp26b1, but not carotenoid metabolism genes, BCO1 and BCO2. Microarray analysis of placental gene expression profile revealed a total of 872 and 756 differentially expressed genes, respectively, compared to the control. Gene set enrichment analysis and functional annotation clustering was performed to characterize the genes differentially expressed in either β-carotene or lycopene-treated HTR-8/SVneo cells. Many known retinoid metabolism related genes and genes involved in regulation of retinoid signaling were found, and the expression profiles of these genes were markedly different in response to β-carotene treatments. Finally, the qRT-PCR and microarray analysis results showed similar gene expression patterns of carotenoid/retinoid metabolism and pathways.
Conclusions : These findings suggest that placental expression of genes involved in retinoid metabolism and transport in trophoblasts is critical for regulating retinoid homeostasis during placental and fetal development. Carotenoid exposure in early placental development, significantly modify the placenta gene expression related to retinoid pathways and maternal to fetal transfer.
Funding Sources : NIH HD421174