Project description:The transcriptome of Ctrl and Vitamin A-deficient longterm hematopoietic stem cells (LT-HSC) and multipotant progenitors (MPP3/4) was assessed by RNAseq.
Project description:Embryonic stem cells (ESC) are derived from blastocyst-stage embryos and are thought to be functionally equivalent to the inner cell mass in their developmental potential. ESCs pluripotency is maintained through a complex interplay of different signaling pathways and a network of transcription factors, which is centered around Oct3/4, Sox2 and Nanog. Although, in general, much is known about this pluripotency self-renewal circuitry, the molecular events that lead ESC to exit from pluripotency and begin differentiation are currently less known. Retinoic acid, an active metabolite of the vitamin A (retinol), plays important and pleiotropic roles in vertebrate embryonic development and ESC differentiation. Here we demonstrate that RA promotes early steps of ESC differentiation, and that ESC increase their capacity to synthesize RA during spontaneous differentiation as embryoid bodies, up-regulating the RA biosynthetic pathway components RDH1, RDH10, ADH3, RALDH2, and CRABP2. Microarray derived from total RNA of mESC not treated or treated with all-trans retinoic acid (ATRA) for 2 hours.
Project description:Dietary vitamin A is metabolized into bioactive retinoic acid in vivo and regulates the development of many embryonic tissues. Retinoic acid signaling is active in the oral ectoderm-derived tissues of the neuroendocrine system, but its role there has not yet been fully explored. We show here that retinoic acid signaling is active during pituitary organogenesis and dependent on the pituitary transcription factor Prop1. Prop1-mutant mice show reduced expression of the aldehyde dehydrogenase gene Aldh1a2, which metabolizes the vitamin A-intermediate retinaldehyde into retinoic acid. In order to elucidate the specific function of RA signaling during neuroendocrine development, we studied a conditional deletion of Aldh1a2 and a dominant-negative mouse model of inhibited retinoic acid signaling during pituitary organogenesis. These models partially phenocopy Prop1-mutant mice by exhibiting embryonic pituitary dysmorphology and reduced hormone expression, especially of thyroid-stimulating hormone. These findings establish the critical role of retinoic acid in embryonic pituitary stem cell progression to differentiated hormone cells and raise the question of gene-by-environment interactions as contributors to pituitary development and disease.
Project description:Antimicrobial proteins form an essential chemical barrier that protects the intestinal epithelium from microbial invasion. REG3 family antimicrobial lectins are prominently induced by the microbiota, but how nutritional cues intersect with microbial signals to regulate their expression is poorly understood. Vitamin A plays a central role in mucosal adaptive immunity, but its contribution to epithelial innate immunity is unclear. Here, we show that dietary vitamin A promotes expression of REG3 antimicrobial lectins, including REG3G, in intestinal epithelial cells from both mice and humans. Vitamin A–dependent induction of REG3G expression is driven by retinoic acid and requires signaling through retinoic acid receptors (RARs). Mechanistically, RARs directly bind the Reg3g promoter adjacent to a binding site for STAT3, the transcription factor that transduces microbial signals, thereby integrating nutritional and microbial inputs at the level of REG3G transcription. Extending these findings, we demonstrate that vitamin A–retinoic acid signaling similarly promotes expression of α-defensin antimicrobial proteins. Together, these results define a transcriptional mechanism by which vitamin A enhances epithelial antimicrobial defenses to strengthen mucosal innate immunity.
Project description:Pyrydopyrazine A2 induced in vitro the differentiation of leukemic cells (HoxA9-Meis1) into macrophages, we decided to perform a transcriptomic study in order to analyze the GM-CSF pathway regulation. We therefore compared effect with A2 to cells treated with Retinoic acid and D3 Vitamin, a combination known to induce also differentiation of leukemic cells. HoxA9-Meis1 murine AML cells were treated in vitro during 24h, with Pyrydopyrazine( A2) at 3.4μM or a combination of all-trans Retinoic Acid (RA) and 1α-hydroxy-D3 Vitamin (D3V), 10μM each. Gene expression signature was compared to untreated control. One sample was tested for each condition
Project description:The contribution of liver sinusoidal endothelial cell (LSEC) zonation to metabolic dysfunction-associated steatotic liver disease (MASLD) pathogenesis remains undefined. We identified selective lipid deposition in the pericentral zone during early MASLD. Multi-omics analyses confirmed enhanced pericentral lipid metabolism in both hepatocytes and LSECs. Mechanistically, pericentral LSEC marker c-Kit transcriptionally activated FGF1 via nuclear receptor RXRG, which suppressed hepatocellular lipid accumulation through FGFR4 signaling. Remarkably, retinoic acid (RXRG’s endogenous ligand and active vitamin A metabolite) phenocopied FGF1’s anti-steatotic effects. Clinical data revealed an inverse correlation between dietary vitamin A and MASLD severity, suggesting therapeutic potential of vitamin A supplementation for early intervention.
Project description:Observational studies in human suggest involvement of vitamin A/retinoic acid (RA) signaling in the regulation of airway smooth muscle (ASM) function, but the precise mechanisms by which RA impacts ASM phenotype is not clear. Here, we generated trascriptional profiles from primary human ASM from 3 unrelated donoros cultured in control medium or medium containing BMS493 (an retinoic acid receptor antagonist)