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Sample records for retinoic acid inducible

  1. Cadmium induces retinoic acid signaling by regulating retinoic acid metabolic gene expression.

    PubMed

    Cui, Yuxia; Freedman, Jonathan H

    2009-09-11

    The transition metal cadmium is an environmental teratogen. In addition, cadmium and retinoic acid can act synergistically to induce forelimb malformations. The molecular mechanism underlying the teratogenicity of cadmium and the synergistic effect with retinoic acid has not been addressed. An evolutionarily conserved gene, beta,beta-carotene 15,15'-monooxygenase (BCMO), which is involved in retinoic acid biosynthesis, was studied in both Caenorhabditis elegans and murine Hepa 1-6 cells. In C. elegans, bcmo-1 was expressed in the intestine and was cadmium inducible. Similarly, in Hepa 1-6 cells, Bcmo1 was induced by cadmium. Retinoic acid-mediated signaling increased after 24-h exposures to 5 and 10 microm cadmium in Hepa 1-6 cells. Examination of gene expression demonstrated that the induction of retinoic acid signaling by cadmium may be mediated by overexpression of Bcmo1. Furthermore, cadmium inhibited the expression of Cyp26a1 and Cyp26b1, which are involved in retinoic acid degradation. These results indicate that cadmium-induced teratogenicity may be due to the ability of the metal to increase the levels of retinoic acid by disrupting the expression of retinoic acid-metabolizing genes. PMID:19556237

  2. Cadmium Induces Retinoic Acid Signaling by Regulating Retinoic Acid Metabolic Gene Expression*

    PubMed Central

    Cui, Yuxia; Freedman, Jonathan H.

    2009-01-01

    The transition metal cadmium is an environmental teratogen. In addition, cadmium and retinoic acid can act synergistically to induce forelimb malformations. The molecular mechanism underlying the teratogenicity of cadmium and the synergistic effect with retinoic acid has not been addressed. An evolutionarily conserved gene, β,β-carotene 15,15′-monooxygenase (BCMO), which is involved in retinoic acid biosynthesis, was studied in both Caenorhabditis elegans and murine Hepa 1–6 cells. In C. elegans, bcmo-1 was expressed in the intestine and was cadmium inducible. Similarly, in Hepa 1–6 cells, Bcmo1 was induced by cadmium. Retinoic acid-mediated signaling increased after 24-h exposures to 5 and 10 μm cadmium in Hepa 1–6 cells. Examination of gene expression demonstrated that the induction of retinoic acid signaling by cadmium may be mediated by overexpression of Bcmo1. Furthermore, cadmium inhibited the expression of Cyp26a1 and Cyp26b1, which are involved in retinoic acid degradation. These results indicate that cadmium-induced teratogenicity may be due to the ability of the metal to increase the levels of retinoic acid by disrupting the expression of retinoic acid-metabolizing genes. PMID:19556237

  3. Retinoic acid-induced neural differentiation of embryonal carcinoma cells.

    PubMed Central

    Jones-Villeneuve, E M; Rudnicki, M A; Harris, J F; McBurney, M W

    1983-01-01

    We have previously shown that the P19 line of embryonal carcinoma cells develops into neurons, astroglia, and fibroblasts after aggregation and exposure to retinoic acid. The neurons were initially identified by their morphology and by the presence of neurofilaments within their cytoplasm. We have more fully documented the neuronal nature of these cells by showing that their cell surfaces display tetanus toxin receptors, a neuronal cell marker, and that choline acetyl-transferase and acetyl cholinesterase activities appear coordinately in neuron-containing cultures. Several days before the appearance of neurons, there is a marked decrease in the amount of an embryonal carcinoma surface antigen, and at the same time there is a substantial decrease in the volumes of individual cells. Various retinoids were able to induce the development of neurons in cultures of aggregated P19 cells, but it did not appear that polyamine metabolism was involved in the effect. We have isolated a mutant clone which does not differentiate in the presence of any of the drugs which are normally effective in inducing differentiation of P19 cells. This mutant and others may help to elucidate the chain of events triggered by retinoic acid and other differentiation-inducing drugs. Images PMID:6656766

  4. Retinoic acid modulation of ultraviolet light-induced epidermal ornithine decarboxylase activity

    SciTech Connect

    Lowe, N.J.; Breeding, J.

    1982-02-01

    Irradiation of skin with ultraviolet light of sunburn range (UVB) leads to a large and rapid induction of the polyamine biosynthetic enzyme ornithine decarboxylase in the epidermis. Induction of epidermal ornithine decarboxylase also occurs following application of the tumor promoting agent 12-0-tetradecanoylphorbol-13 acetate and topical retinoic acid is able to block both this ornithine decarboxylase induction and skin tumor promotion. In the studies described below, topical application of retinoic acid to hairless mouse skin leads to a significant inhibition of UVB-induced epidermal ornithine decarboxylase activity. The degree of this inhibition was dependent on the dose, timing, and frequency of the application of retinoic acid. To show significant inhibition of UVB-induced ornithine decarboxylase the retinoic acid had to be applied within 5 hr of UVB irradiation. If retinoic acid treatment was delayed beyond 7 hr following UVB, then no inhibition of UVB-induced ornithine decarboxylase was observed. The quantities of retinoic acid used (1.7 nmol and 3.4 nmol) have been shown effective at inhibiting 12-0-tetradecanoyl phorbol-13 acetate induced ornithine decarboxylase. The results show that these concentrations of topical retinoic acid applied either before or immediately following UVB irradiation reduces the UVB induction of epidermal ornithine decarboxylase. The effect of retinoic acid in these regimens on UVB-induced skin carcinogenesis is currently under study.

  5. Characterization of retinoic acid-induced neurobehavioral effects in developing zebrafish.

    PubMed

    Wang, Yujiang; Chen, Jiangfei; Du, Changchun; Li, Chunqi; Huang, Changjiang; Dong, Qiaoxiang

    2014-02-01

    Retinoic signaling plays an important role in cell proliferation and differentiation. Disruption of retinoic signaling via excessive or deficient retinoic acid can cause teratogenic effects on developing embryos. Similar to retinoic acid, many xenobiotic environmental pollutants have been found to disrupt retinoic signaling through binding and eliciting agonistic activity on retinoic acid receptors. Currently, studies of retinoic acid or retinoic acid-like compounds in aquatic organisms have mainly focused on teratogenicity and few studies have explored their neurobehavioral toxicity. In the present study, the authors used retinoic acid as an example to explore the neurobehavioral toxicity associated with developmental exposure of retinoic acid-like compounds in zebrafish. The findings confirmed retinoic acid's teratogenic effects such as bent spine, malformed tail, and pericardial edema in developing zebrafish with a median effective concentration of 2.47 nM. Retinoic acid-induced cell apoptosis at 24 h postfertilization was consistently found in the eye and tail regions of embryos. Spontaneous movement as characterized by tail bend frequency was significantly increased in zebrafish embryos following exposure to 2 nM and 8 nM retinoic acid. Relatively low-dose retinoic acid exposure of 2 nM led to fast locomotion behavior in the dark period and hyperactivity during light-dark photoperiod stimulation. The 2-nM retinoic acid exposure also led to alterations of neurobehavior- and optic nerve-related genes, with the transforming growth factor-β signal transduction inhibitor noggin (nog) and the spinal cord marker homeobox c3a (hox) being underexpressed and the retinal G protein-coupled receptor a (rgr), the photoreceptor cell marker rhodopsin (rho), and the short wave-sensitive cone pigment opsin 1 (opn1sw1) being overexpressed. Increased expression of opn1sw1 and rho was confirmed by whole-mount in situ hybridization. Whether the misexpression of these genes leads

  6. RETINOIC ACID ALTERS EPITHELIAL DIFFERENTIATION DURING PALATOGENESIS

    EPA Science Inventory

    Retinoids are teratogenic in humans and animals, producing a syndrome of craniofacial malformations which includes cleft palate. his study investigates the mechanism through which retinoic acid induces cleft palate. urine palatogenesis after exposure to retinoic acid in utero is ...

  7. A paradoxical teratogenic mechanism for retinoic acid.

    PubMed

    Lee, Leo M Y; Leung, Chun-Yin; Tang, Walfred W C; Choi, Heung-Ling; Leung, Yun-Chung; McCaffery, Peter J; Wang, Chi-Chiu; Woolf, Adrian S; Shum, Alisa S W

    2012-08-21

    Retinoic acid, an active metabolite of vitamin A, plays essential signaling roles in mammalian embryogenesis. Nevertheless, it has long been recognized that overexposure to vitamin A or retinoic acid causes widespread teratogenesis in rodents as well as humans. Although it has a short half-life, exposure to high levels of retinoic acid can disrupt development of yet-to-be formed organs, including the metanephros, the embryonic organ which normally differentiates into the mature kidney. Paradoxically, it is known that either an excess or a deficiency of retinoic acid results in similar malformations in some organs, including the mammalian kidney. Accordingly, we hypothesized that excess retinoic acid is teratogenic by inducing a longer lasting, local retinoic acid deficiency. This idea was tested in an established in vivo mouse model in which exposure to excess retinoic acid well before metanephric rudiments exist leads to failure of kidney formation several days later. Results showed that teratogen exposure was followed by decreased levels of Raldh transcripts encoding retinoic acid-synthesizing enzymes and increased levels of Cyp26a1 and Cyp26b1 mRNAs encoding enzymes that catabolize retinoic acid. Concomitantly, there was significant reduction in retinoic acid levels in whole embryos and kidney rudiments. Restoration of retinoic acid levels by maternal supplementation with low doses of retinoic acid following the teratogenic insult rescued metanephric kidney development and abrogated several extrarenal developmental defects. This previously undescribed and unsuspected mechanism provides insight into the molecular pathway of retinoic acid-induced teratogenesis. PMID:22869719

  8. All-trans retinoic acid potentiates cisplatin-induced kidney injury in rats: impact of retinoic acid signaling pathway.

    PubMed

    Elsayed, Abdelrahman M; Abdelghany, Tamer M; Akool, El-Sayed; Abdel-Aziz, Abdel-Aziz H; Abdel-Bakky, Mohamed S

    2016-03-01

    Cisplatin (cis-diammine dichloroplatinum (II), CDDP) is a widely used drug for treatment of various types of cancers. However, CDDP-induced nephrotoxicity remains the main dose-limiting side effect. Retinoids are a group of vitamin A-related compounds that exert their effects through retinoid receptors activation. In this study, we investigated the effect of CDDP treatment on retinoic acid receptor-α (RAR-α) and retinoid X receptor-α (RXR-α) expression. In addition, we investigated the possible modulatory effects of RAR agonist, all-trans retinoic acid (ATRA), on CDDP-induced nephrotoxicity. Rats were treated with saline, DMSO, CDDP, ATRA, or CDDP/ATRA. Twenty-four hours after the last ATRA injection, rats were killed; blood samples were collected; kidneys were dissected; and biochemical, immunohistochemical, and histological examinations were performed. Our results revealed that CDDP treatment significantly increased serum levels of creatinine and urea, with concomitant decrease in serum albumin. Moreover, reduced glutathione (GSH) content as well as superoxide dismutase (SOD) and catalase (CAT) activities were significantly reduced with concurrent increase in kidney malondialdehyde (MDA) content following CDDP treatment. Furthermore, CDDP markedly upregulated tubular RAR-α, RXR-α, fibrin, and inducible nitric oxide synthase (iNOS) protein expression. Although administration of ATRA to control rats did not produce marked alterations in kidney function parameters, administration of ATRA to CDDP-treated rats significantly exacerbated CDDP-induced nephrotoxicity. In addition, CDDP/ATRA co-treatment significantly increased RAR-α, RXR-α, fibrin, and iNOS protein expression compared to CDDP alone. In conclusion, we report, for the first time, the crucial role of retinoid receptors in CDDP-induced nephrotoxicity. Moreover, our findings indicate that co-administration of ATRA with CDDP, although beneficial on the therapeutic effects, their deleterious effects on

  9. Intracrine prostaglandin E(2) signalling regulates hypoxia-inducible factor-1α expression through retinoic acid receptor-β.

    PubMed

    Fernández-Martínez, Ana B; Jiménez, María I Arenas; Manzano, Victoria Moreno; Lucio-Cazaña, Francisco J

    2012-12-01

    We have previously found in human renal proximal tubular HK-2 cells that hypoxia- and all-trans retinoic acid-induced hypoxia-inducible factor-1α up-regulation is accompanied by retinoic acid receptor-β up-regulation. Here we first investigated whether hypoxia-inducible factor-1α expression is dependent on retinoic acid receptor-β and our results confirmed it since (i) hypoxia-inducible factor-1α-inducing agents hypoxia, hypoxia-mimetic agent desferrioxamine, all-trans retinoic acid and interleukin-1β increased retinoic acid receptor-β expression, (ii) hypoxia-inducible factor-1α up-regulation was prevented by retinoic acid receptor-β antagonist LE-135 or siRNA retinoic acid receptor-β and (iii) there was direct binding of retinoic acid receptor-β to the retinoic acid response element in hypoxia-inducible factor-1α promoter upon treatment with all-trans retinoic acid and 16,16-dimethyl-prostaglandin E(2). Since intracellular prostaglandin E(2) mediates hypoxia-inducible factor-1α up-regulation in normoxia in HK-2 cells, we next investigated and confirmed, its role in the up-regulation of retinoic acid receptor-β in normoxia by hypoxia-inducible factor-1α-inducing agents all-trans retinoic acid, interleukin-1β and 16,16-dimethyl-prostaglandin E(2) by inhibiting cyclooxygenases, prostaglandin influx transporter or EP receptors. Interestingly, the hypoxia-induced increase in retinoic acid receptor-β expression and accumulation of hypoxia-inducible factor-1α was also blocked by the inhibitors tested. This is the first time, to our knowledge, that retinoic acid receptor-β signalling is involved in the control of the expression of transcription factor hypoxia-inducible factor-1α in both normoxia and hypoxia and that retinoic acid receptor-β expression is found to be strictly regulated by intracellular prostaglandin E(2). Given the relevance of hypoxia-inducible factor-1α in the kidney in terms of tumorigenesis, progressive renal failure, production

  10. All-trans retinoic acid mitigates methotrexate-induced liver injury in rats; relevance of retinoic acid signaling pathway.

    PubMed

    Ewees, Mohamed G; Abdelghany, Tamer M; Abdel-Aziz, Abdel-Aziz H; Abdel-Bakky, Mohamed S

    2015-09-01

    Methotrexate (MTX) is a widely used drug for treatment of rheumatic and autoimmune diseases as well as different types of cancer. One of the major side effects of MTX is hepatotoxicity. Retinoid receptors, including retinoid X receptor (RXR), and retinoic acid receptor (RAR) are vitamin A receptors that are highly expressed in the liver and regulate important physiological processes through regulation of different genes. In this study, we investigated the effect of MTX on RXR-α and RAR-α expression in the liver and the potential protective effects of all-trans retinoic acid (ATRA) in MTX-induced hepatotoxicity. Rats were randomly divided into five groups: The rates were treated with saline, DMSO, MTX (20 mg/kg/IP; single dose), ATRA (7.5 mg/kg/day, I.P), or MTX and ATRA. Rats were killed 24 h after the last ATRA injection. The liver tissues were dissected out, weighed, and subjected to histological, immunohistochemical, and biochemical examinations. Our results demonstrated that treatment with MTX resulted in significant decrease in reduced glutathione (GSH) content and superoxide dismutase (SOD) activity, with concomitant increase in ALT, AST, and MDA levels. In addition, MTX markedly downregulated the expression of both RXR-α and RAR-α, and changed the appearance of RXR-α to be very small speckled droplets. Treatment with ATRA significantly ameliorated MTX-induced effects on GSH, ALT, and MDA. Moreover, ATRA administration increased the expression and nuclear translocation of RXR-α in rat hepatocytes. In conclusion, our study revealed, for the first time, that retinoid receptors may play an important role in the MTX-induced hepatotoxicity. PMID:25971792

  11. STRUCTURAL REMODELING OF PROTEOGLYCANS UPON RETINOIC ACID-INDUCED DIFFERENTIATION OF NCCIT CELLS*

    PubMed Central

    Gasimli, Leyla; Stansfield, Hope E.; Nairn, Alison V.; Liu, Haiying; Paluh, Janet L.; Yang, Bo; Dordick, Jonathan S.; Moremen, Kelley W.; Linhardt, Robert J.

    2012-01-01

    Pluripotent and multipotent cells become increasingly lineage restricted through differentiation. Alterations to the cellular proteoglycan composition and structure should accompany these changes to influence cell proliferation, delineation of tissues and acquisition of cell migration capabilities. Retinoic acid plays an important role in pre-patterning of the early embryo. Retinoic acid can be used in vitro to induce differentiation, causing pluripotent and multipotent cells to become increasingly lineage restricted. We examined retinoic acid-induced changes in the cellular proteoglycan composition of the well-characterized teratocarcinoma line NCCIT. Our analysis revealed changes in the abundance of transcripts for genes encoding core proteins, enzymes that are responsible for early and late linkage region biosynthesis, as well as enzymes for GAG chain extension and modification. Transcript levels for genes encoding core proteins used as backbones for polysaccharide synthesis revealed highly significant increases in expression of lumican and decorin, 1500-fold and 2800-fold, respectively. Similarly, glypican 3, glypican 5, versican and glypican 6 showed increases between 5 and 70-fold. Significant decreases in biglycan, serglycin, glypican 4, aggrecan, neurocan, CD74 and glypican 1 were observed. Disaccharide analysis of the glycans in heparin/heparan sulfate and chondroitin/dermatan sulfate revealed retinoic acid-induced changes restricted to chondroitin/dermatan sulfate glycans. Our study provides the first detailed analysis of changes in the glycosaminoglycan profile of human pluripotent cells upon treatment with the retinoic acid morphogen. PMID:23053635

  12. Structural remodeling of proteoglycans upon retinoic acid-induced differentiation of NCCIT cells.

    PubMed

    Gasimli, Leyla; Stansfield, Hope E; Nairn, Alison V; Liu, Haiying; Paluh, Janet L; Yang, Bo; Dordick, Jonathan S; Moremen, Kelley W; Linhardt, Robert J

    2013-07-01

    Pluripotent and multipotent cells become increasingly lineage restricted through differentiation. Alterations to the cellular proteoglycan composition and structure should accompany these changes to influence cell proliferation, delineation of tissues and acquisition of cell migration capabilities. Retinoic acid plays an important role in pre-patterning of the early embryo. Retinoic acid can be used in vitro to induce differentiation, causing pluripotent and multipotent cells to become increasingly lineage restricted. We examined retinoic acid-induced changes in the cellular proteoglycan composition of the well-characterized teratocarcinoma line NCCIT. Our analysis revealed changes in the abundance of transcripts for genes encoding core proteins, enzymes that are responsible for early and late linkage region biosynthesis, as well as enzymes for GAG chain extension and modification. Transcript levels for genes encoding core proteins used as backbones for polysaccharide synthesis revealed highly significant increases in expression of lumican and decorin, 1,500-fold and 2,800-fold, respectively. Similarly, glypican 3, glypican 5, versican and glypican 6 showed increases between 5 and 70-fold. Significant decreases in biglycan, serglycin, glypican 4, aggrecan, neurocan, CD74 and glypican 1 were observed. Disaccharide analysis of the glycans in heparin/heparan sulfate and chondroitin/dermatan sulfate revealed retinoic acid-induced changes restricted to chondroitin/dermatan sulfate glycans. Our study provides the first detailed analysis of changes in the glycosaminoglycan profile of human pluripotent cells upon treatment with the retinoic acid morphogen. PMID:23053635

  13. Retinoic acid-primed human dendritic cells inhibit Th9 cells and induce Th1/Th17 cell differentiation.

    PubMed

    Rampal, Ritika; Awasthi, Amit; Ahuja, Vineet

    2016-07-01

    All-trans-retinoic acid plays a central role in mucosal immunity, where it promotes its synthesis by up-regulating CD103 expression on dendritic cells, induces gut tropic (α4β7(+) and CCR9(+)) T cells, and inhibits Th1/Th17 differentiation. Recently, murine studies have highlighted the proinflammatory role of retinoic acid in maintaining inflammation under a variety of pathologic conditions. However, as a result of limited human data, we investigated the effect of retinoic acid on human dendritic cells and CD4(+) T cell responses in the presence of polarizing (Th1/Th9/Th17) and inflammatory (LPS-induced dendritic cells) conditions. We report a novel role of retinoic acid in an inflammatory setup, where retinoic acid-primed dendritic cells (retinoic acid-monocyte-derived dendritic cells) up-regulated CCR9(+)T cells, which were observed to express high levels of IFN-γ in the presence of Th1/Th17 conditions. Retinoic acid-monocyte-derived dendritic cells, under Th17 conditions, also favored the induction of IL-17(+) T cells. Furthermore, in the presence of TGF-β1 and IL-4, retinoic acid-monocyte-derived dendritic cells inhibited IL-9 and induced IFN-γ expression on T cells. Experiments with naïve CD4(+) T cells, activated in the presence of Th1/Th17 conditions and absence of DCs, indicated that retinoic acid inhibited IFN-γ and IL-17 expression on T cells. These data revealed that in the face of inflammatory conditions, retinoic acid, in contrast from its anti-inflammatory role, could maintain or aggravate the intestinal inflammation. PMID:26980802

  14. Retinoic acid activates human inducible nitric oxide synthase gene through binding of RAR{alpha}/RXR{alpha} heterodimer to a novel retinoic acid response element in the promoter

    SciTech Connect

    Zou Fang; Liu Yan; Liu Li; Wu Kailang; Wei Wei; Zhu Ying . E-mail: yingzhu@whu.edu.cn; Wu Jianguo . E-mail: wu9988@vip.sina.com

    2007-04-06

    Human inducible nitric oxide synthase (hiNOS) catalyzes nitric oxide (NO) which has a significant effect on tumor suppression and cancer therapy. Here we revealed the detailed molecular mechanism involved in the regulation of hiNOS expression induced by retinoic acid (RA). We showed that RAR{alpha}/RXR{alpha} heterodimer was important in hiNOS promoter activation, hiNOS protein expression, and NO production. Serial deletion and site-directed mutation analysis revealed two half-sites of retinoic acid response element (RARE) spaced by 5 bp located at -172 to -156 in the hiNOS promoter. EMSA and ChIP assays demonstrated that RAR{alpha}/RXR{alpha} directly bound to this RARE of hiNOS promoter. Our results suggested the identification of a novel RARE in the hiNOS promoter and the roles of the nuclear receptors (RAR{alpha}/RXR{alpha}) in the induction of hiNOS by RA.

  15. Retinoic acid induces cells cultured from oral squamous cell carcinomas to become anti-angiogenic.

    PubMed Central

    Lingen, M. W.; Polverini, P. J.; Bouck, N. P.

    1996-01-01

    Retinoids have shown great promise as chemopreventive against the development of squamous cell carcinomas of the upper aerodigestive tract. However, the exact mechanism by which they block new tumors from arising is unknown. Here, we report that 13-cis- and all-trans-retinoic acid, used at clinically achievable doses of 10(-6) mol/L or less, can directly and specifically affect cell lines cultured from oral squamous cell carcinomas, inducing them to switch from an angiogenic to an anti-angiogenic phenotype. Although retinoic-acid-treated and untreated tumor cells make the same amount of interleukin-8, the major inducer of neovascularization produced by such tumor lines, they vary in production of inhibitory activity. Only the retinoic-acid-treated cells produce a potent angio-inhibitory activity that is able to block in vitro migration of endothelial cells toward tumor cell conditioned media and to halt neovascularization induced by such media in the rat cornea. Anti-angiogenic activity is induced in the tumor cells by low doses of retinoids in the absence of toxicity with a kinetics that suggest that it could be contributing to the effectiveness of the retinoids as chemopreventive agents. Images Figure 6 PMID:8686749

  16. LIMB DEFECTS INDUCED BY RETINOIC ACID SIGNALING ANTAGONISM AND SYNTHESIS INHIBITION ARE CONSISTENT WITH ETHANOL-INDUCED LIMB DEFECTS

    EPA Science Inventory

    Limb defects induced by retinoic acid signaling antagonism and synthesis inhibition are consistent with ethanol-induced limb defects

    Johnson CS1, Sulik KK1,2, Hunter, ES III3
    1Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, NC....

  17. Expression in the human brain of retinoic acid induced 1, a protein associated with neurobehavioural disorders.

    PubMed

    Fragoso, Yara Dadalti; Stoney, Patrick N; Shearer, Kirsty D; Sementilli, Angelo; Nanescu, Sonia E; Sementilli, Pietro; McCaffery, Peter

    2015-03-01

    Retinoic acid induced 1 (RAI1) is a protein of uncertain mechanism of action which nevertheless has been the focus of attention because it is a major contributing factor in several human developmental disorders including Smith-Magenis and Potocki-Lupski syndromes. Further, RAI1 may be linked to adult neural disorders with developmental origins such as schizophrenia and autism. The protein has been extensively examined in the rodent but very little is known about its distribution in the human central nervous system. This study demonstrated the presence of RAI1 transcript in multiple regions of the human brain. The cellular expression of RAI1 protein in the human brain was found to be similar to that described in the mouse, with high levels in neurons, but not glia, of the dentate gyrus and cornus ammonis of the hippocampus. In the cerebellum, a second region of high expression, RAI1 was present in Purkinje cells, but not granule cells. RAI1 was also found in neurons of the occipital cortex. The expression of this retinoic acid-induced protein matched well in the hippocampus with expression of the retinoic acid receptors. The subcellular distribution of human neuronal RAI1 indicated its presence in both cytoplasm and nucleus. Overall, human RAI1 protein was found to be a highly expressed neuronal protein whose distribution matches well with its role in cognitive and motor skills. PMID:24519454

  18. The Expression of Bone Morphogenetic Protein 2 and Matrix Metalloproteinase 2 through Retinoic Acid Receptor Beta Induced by All-Trans Retinoic Acid in Cultured ARPE-19 Cells

    PubMed Central

    Gao, Zhenya; Huo, Lijun; Cui, Dongmei; Yang, Xiao; Zeng, Junwen

    2016-01-01

    Purpose All-trans retinoic acid (ATRA) plays an important role in ocular development. Previous studies found that retinoic acid could influence the metabolism of scleral remodeling by promoting retinal pigment epithelium (RPE) cells to secrete secondary signaling factors. The purpose of this study was to investigate whether retinoic acid affected secretion of bone morphogenetic protein 2 (BMP-2) and matrix metalloproteinase 2 (MMP-2) and to explore the signaling pathway of retinoic acid in cultured acute retinal pigment epithelial 19 (ARPE-19) cells. Methods The effects of ATRA (concentrations from 10−9 to 10−5 mol/l) on the expression of retinoic acid receptors (RARs) in ARPE-19 cells were examined at the mRNA and protein levels using reverse transcription-polymerase chain reaction (RT-PCR) and western blot assay, respectively. The effects of treating ARPE-19 cells with ATRA concentrations ranging from 10−9 to 10−5 mol/l for 24 h and 48 h or with 10-6mol/l ATRA at different times ranging from 6h to 72h were assessed using real-time quantitative PCR (qPCR) and enzyme-linked immunosorbent assay (ELISA). The contribution of RARβ-induced activation of ARPE-19 cells was confirmed using LE135, an antagonist of RARβ. Results RARβ mRNA levels significantly increased in the ARPE-19 cells treated with ATRA for 24h and 48h. These increases in RARβ mRNA levels were dose dependent (at concentrations of 10−9 to 10−5 mol/l) with a maximum effect observed at 10−6 mol/l. There were no significant changes in the mRNA levels of RARα and RARγ. Western blot assay revealed that RARβ protein levels were increased significantly in a time-dependent manner in ARPE-19 cells treated with 10−6 mol/l ATRA from 12 h to 72 h, with a marked increase observed at 24 h and 48 h. The upregulation of RARβ and the ATRA-induced secretion in ARPE-19 cells could be inhibited by the RARβ antagonist LE135. Conclusion ATRA induced upregulation of RARβ in ARPE-19 cells and stimulated

  19. Retinoic acid reduces solvent-induced neuropathy and promotes neural regeneration in mice.

    PubMed

    Palencia, Guadalupe; Hernández-Pedro, Norma; Saavedra-Perez, David; Peña-Curiel, Omar; Ortiz-Plata, Alma; Ordoñez, Graciela; Flores-Estrada, Diana; Sotelo, Julio; Arrieta, Oscar

    2014-08-01

    In humans, exposure to organic solvents (OS) is frequent in work activities or as a recreational inhalant, inducing severe neuropathy (secondary to demyelization of peripheral nerves). We have previously shown that all-trans retinoic acid (ATRA) increases local content of neural growth factor (NGF), improving peripheral neuropathy of diverse origins. In this study, we evaluated the effect of ATRA on OS-induced peripheral neuropathy in experimental mice. Two simultaneous experiments were performed. The first one aimed to evaluate ATRA for the prevention of damage induced by OS, the second to test ATRA as an OS-induced neuropathy treatment. Nociceptive threshold latency and NGF concentration in serum and in peripheral nerves were determined. Morphological changes and evidence of sciatic nerve regeneration were evaluated. Mice exposed to OS developed neuropathy and axonal degeneration. ATRA diminished the effects of OS inhalation on sensorial changes and nerve morphology. Treatment with ATRA reversed sensorial and nerve morphological changes of OS-induced neuropathy, and this was associated with increased contents of NGF. Similar to previous experiences on diabetic and toxic neuropathy, ATRA reduced and partially reversed the peripheral neuropathy caused by OS exposure. These favorable effects apparently are due to local production of NGF induced by neural regeneration in response to the administration of retinoic acid. PMID:24647975

  20. Retinoic Acid Receptor α Mediates All-trans-retinoic Acid-induced Klf4 Gene Expression by Regulating Klf4 Promoter Activity in Vascular Smooth Muscle Cells*

    PubMed Central

    Shi, Jian-hong; Zheng, Bin; Chen, Si; Ma, Guo-yan; Wen, Jin-kun

    2012-01-01

    The transcription factor Krüppel-like factor 4 (KLF4) plays a critical role in vascular smooth muscle cell (VSMC) differentiation induced by all-trans-retinoic acid (ATRA). Although it has been demonstrated that ATRA stimulation augments both KLF4 protein and mRNA levels in VSMCs, the molecular mechanisms by which ATRA regulates Klf4 transcription are unknown. In this study, we examined the roles of ATRA-selective nuclear retinoic acid receptors (RARs) in the transcriptional regulation of Klf4. The introduction of small interfering RNA and an RAR antagonist demonstrated that RARα, but not RARβ or RARγ, mediated ATRA-induced Klf4 expression. A luciferase assay for the Klf4 promoter showed that three GC boxes in the proximal Klf4 promoter were indispensible for ATRA-induced Klf4 transcription and that RARα enhanced Klf4 promoter activity in a GC box-dependent manner. Furthermore, chromatin immunoprecipitation and oligonucleotide pulldown assays demonstrated that the transcription factors KLF4, Sp1, and YB1 directly bound to the GC boxes of the proximal Klf4 promoter. Upon RARα agonist stimulation, RARα was recruited to the Klf4 promoter through its interaction with KLF4, Sp1, and YB1 to form a transcriptional activation complex on the three GC boxes of the Klf4 promoter. These results suggest that RARα serves as an essential co-activator for ATRA signaling and that the recruitment of RARα to the KLF4-Sp1-YB1 complex, which leads to Klf4 expression in VSMCs, is independent of a retinoic acid response element. PMID:22337869

  1. Retinoic acid metabolism proteins are altered in trichoblastomas induced by mouse papillomavirus 1.

    PubMed

    Everts, Helen B; Suo, Liye; Ghim, Shinge; Bennett Jenson, A; Sundberg, John P

    2015-12-01

    Skin cancer burden is significant as treatment costs have skyrocketed to $8.1 million annually and some forms metastasize, such as cutaneous squamous cell carcinoma (cSCC) and melanoma. cSCC is caused by altered growth factor signaling induced by chemical carcinogens, ultraviolet light (UV) exposure, and infections with papillomaviruses (PVs). One of the few options for preventing cSCC in high-risk patients is oral retinoids. While much is understood about retinoid treatments and metabolism in mouse models of chemically and UV exposure induced cSCC, little is known about the role of retinoids in PV-induced cSCC. To better understand how retinoid metabolism is altered in cSCC, we examined the expression of this pathway in the newly discovered mouse papillomavirus (MmuPV1), which produces trichoblastomas in dorsal skin but not cSCC. We found significant increases in a rate-limiting enzyme involved in retinoic acid synthesis and retinoic acid binding proteins, suggestive of increased RA synthesis, in MmuPV1-induced tumors in B6.Cg-Foxn1(nu)/J mice. Similar increases in these proteins were seen after acute UVB exposure in Crl:SKH1-Hr(hr) mice and in regressing pre-cancerous lesions in a chemically-induced mouse model, suggesting a common mechanism in limiting the progression of papillomas to full blown cSCC. PMID:26416148

  2. Different agonist- and antagonist-induced conformational changes in retinoic acid receptors analyzed by protease mapping.

    PubMed Central

    Keidel, S; LeMotte, P; Apfel, C

    1994-01-01

    The pleiotropic effects of retinoic acid on cell differentiation and proliferation are mediated by two subfamilies of nuclear receptors, the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs). Recently the synthetic retinoid Ro 41-5253 was identified as a selective RAR alpha antagonist. As demonstrated by gel retardation assays, Ro 41-5253 and two related new RAR alpha antagonists do not influence RAR alpha/RXR alpha heterodimerization and DNA binding. In a limited trypsin digestion assay, complexation of RAR alpha with retinoic acid or several other agonistic retinoids altered the degradation of the receptor such that a 30-kDa proteolytic fragment became resistant to proteolysis. This suggests a ligand-induced conformational change, which may be necessary for the interaction of the DNA-bound RAR alpha/RXR alpha heterodimer with other transcription factors. Our results demonstrate that antagonists compete with agonists for binding to RAR alpha and may induce a different structural alteration, suggested by the tryptic resistance of a shorter 25-kDa protein fragment in the digestion assay. This RAR alpha conformation seems to allow RAR alpha/RXR alpha binding to DNA but not the subsequent transactivation of target genes. Protease mapping with C-terminally truncated receptors revealed that the proposed conformational changes mainly occur in the DE regions of RAR alpha. Complexation of RAR beta, RAR gamma, and RXR alpha, as well as the vitamin D3 receptor, with their natural ligands resulted in a similar resistance of fragments to proteolytic digestion. This could mean that ligand-induced conformational changes are a general feature in the hormonal activation of vitamin D3 and retinoid receptors. Images PMID:8264595

  3. Zebrafish retinal defects induced by ethanol exposure are rescued by retinoic acid and folic acid supplement

    PubMed Central

    Muralidharan, Pooja; Sarmah, Swapnalee; Marrs, James A.

    2014-01-01

    Fetal Alcohol Spectrum Disorder (FASD) is caused by prenatal alcohol exposure, producing craniofacial, sensory, motor, and cognitive defects. FASD is highly prevalent in low socioeconomic populations, which are frequently accompanied by malnutrition. FASD-associated ocular pathologies include microphthalmia, optic nerve hypoplasia, and cataracts. The present study characterizes specific retinal tissue defects, identifies ethanol-sensitive stages during retinal development, and dissects the effect of nutrient supplements, such as retinoic acid (RA) and folic acid (FA) on ethanol-induced retinal defects. Exposure to pathophysiological concentrations of ethanol (during midblastula transition through somitogenesis; 2–24 hours post fertilization [hpf]) altered critical transcription factor expression involved in retinal cell differentiation, and produced severe retinal ganglion cell, photoreceptor, and Müller glial differentiation defects. Ethanol exposure did not alter retinal cell differentiation induction, but increased retinal cell death and proliferation. RA and FA nutrient co-supplementation rescued retinal photoreceptor and ganglion cell differentiation defects. Ethanol exposure during retinal morphogenesis stages (16–24 hpf) produced retinal defects like those seen with ethanol exposure between 2–24 hpf. Significantly, during an ethanol-sensitive time window (16–24 hpf), RA co-supplementation moderately rescued these defects, whereas FA co-supplementation showed significant rescue of optic nerve and photoreceptor differentiation defects. Interestingly, RA, but not FA, supplementation after ethanol exposure could reverse ethanol-induced optic nerve and photoreceptor differentiation defects. Our results indicate that various ethanol-sensitive events underlie FASD-associated retinal defects. Nutrient supplements like retinoids and folate were effective in alleviating ethanol-induced retinal defects. PMID:25541501

  4. Zebrafish retinal defects induced by ethanol exposure are rescued by retinoic acid and folic acid supplement.

    PubMed

    Muralidharan, Pooja; Sarmah, Swapnalee; Marrs, James A

    2015-03-01

    Fetal Alcohol Spectrum Disorder (FASD) is caused by prenatal alcohol exposure, producing craniofacial, sensory, motor, and cognitive defects. FASD is highly prevalent in low socioeconomic populations, which are frequently accompanied by malnutrition. FASD-associated ocular pathologies include microphthalmia, optic nerve hypoplasia, and cataracts. The present study characterizes specific retinal tissue defects, identifies ethanol-sensitive stages during retinal development, and dissects the effect of nutrient supplements, such as retinoic acid (RA) and folic acid (FA) on ethanol-induced retinal defects. Exposure to pathophysiological concentrations of ethanol (during midblastula transition through somitogenesis; 2-24 h post fertilization [hpf]) altered critical transcription factor expression involved in retinal cell differentiation, and produced severe retinal ganglion cell, photoreceptor, and Müller glial differentiation defects. Ethanol exposure did not alter retinal cell differentiation induction, but increased retinal cell death and proliferation. RA and FA nutrient co-supplementation rescued retinal photoreceptor and ganglion cell differentiation defects. Ethanol exposure during retinal morphogenesis stages (16-24 hpf) produced retinal defects like those seen with ethanol exposure between 2 and 24 hpf. Significantly, during an ethanol-sensitive time window (16-24 hpf), RA co-supplementation moderately rescued these defects, whereas FA co-supplementation showed significant rescue of optic nerve and photoreceptor differentiation defects. Interestingly, RA, but not FA, supplementation after ethanol exposure could reverse ethanol-induced optic nerve and photoreceptor differentiation defects. Our results indicate that various ethanol-sensitive events underlie FASD-associated retinal defects. Nutrient supplements like retinoids and folate were effective in alleviating ethanol-induced retinal defects. PMID:25541501

  5. PI3K/AKT and ERK regulate retinoic acid-induced neuroblastoma cellular differentiation

    SciTech Connect

    Qiao, Jingbo; Paul, Pritha; Lee, Sora; Qiao, Lan; Josifi, Erlena; Tiao, Joshua R.; Chung, Dai H.

    2012-08-03

    Highlights: Black-Right-Pointing-Pointer Retinoic acid (RA) induces neuroblastoma cells differentiation, which is accompanied by G0/G1 cell cycle arrest. Black-Right-Pointing-Pointer RA resulted in neuroblastoma cell survival and inhibition of DNA fragmentation; this is regulated by PI3K pathway. Black-Right-Pointing-Pointer RA activates PI3K and ERK1/2 pathway; PI3K pathway mediates RA-induced neuroblastoma cell differentiation. Black-Right-Pointing-Pointer Upregulation of p21 is necessary for RA-induced neuroblastoma cell differentiation. -- Abstract: Neuroblastoma, the most common extra-cranial solid tumor in infants and children, is characterized by a high rate of spontaneous remissions in infancy. Retinoic acid (RA) has been known to induce neuroblastoma differentiation; however, the molecular mechanisms and signaling pathways that are responsible for RA-mediated neuroblastoma cell differentiation remain unclear. Here, we sought to determine the cell signaling processes involved in RA-induced cellular differentiation. Upon RA administration, human neuroblastoma cell lines, SK-N-SH and BE(2)-C, demonstrated neurite extensions, which is an indicator of neuronal cell differentiation. Moreover, cell cycle arrest occurred in G1/G0 phase. The protein levels of cyclin-dependent kinase inhibitors, p21 and p27{sup Kip}, which inhibit cell proliferation by blocking cell cycle progression at G1/S phase, increased after RA treatment. Interestingly, RA promoted cell survival during the differentiation process, hence suggesting a potential mechanism for neuroblastoma resistance to RA therapy. Importantly, we found that the PI3K/AKT pathway is required for RA-induced neuroblastoma cell differentiation. Our results elucidated the molecular mechanism of RA-induced neuroblastoma cellular differentiation, which may be important for developing novel therapeutic strategy against poorly differentiated neuroblastoma.

  6. Triphenyl phosphate-induced developmental toxicity in zebrafish: Potential role of the retinoic acid receptor

    PubMed Central

    Isales, Gregory M.; Hipszer, Rachel A.; Raftery, Tara D.; Chen, Albert; Stapleton, Heather M.; Volz, David C.

    2015-01-01

    Using zebrafish as a model, we previously reported that developmental exposure to triphenyl phosphate (TPP) – a high-production volume organophosphate-based flame retardant – results in dioxin-like cardiac looping impairments that are independent of the aryl hydrocarbon receptor. Using a pharmacologic approach, the objective of this study was to investigate the potential role of retinoic acid receptor (RAR) – a nuclear receptor that regulates vertebrate heart morphogenesis – in mediating TPP-induced developmental toxicity in zebrafish. We first revealed that static exposure of zebrafish from 5-72 hours post-fertilization (hpf) to TPP in the presence of non-toxic concentrations of an RAR antagonist (BMS493) significantly enhanced TPP-induced toxicity (relative to TPP alone), even though identical non-toxic BMS493 concentrations mitigated retinoic acid (RA)-induced toxicity. BMS493-mediated enhancement of TPP toxicity was not a result of differential TPP uptake or metabolism, as internal embryonic doses of TPP and diphenyl phosphate (DPP) – a primary TPP metabolite - were not different in the presence or absence of BMS493. Using real-time PCR, we then quantified the relative change in expression of cytochrome P450 26a1 (cyp26a1) – a major target gene for RA-induced RAR activation in zebrafish – and found that RA and TPP exposure resulted in a ∼5-fold increase and decrease in cyp26a1 expression, respectively, relative to vehicle-exposed embryos. To address whether TPP may interact with human RARs, we then exposed Chinese hamster ovary cells stably transfected with chimeric human RARα-, RARβ-, or RARγ to TPP in the presence of RA, and found that TPP significantly inhibited RA-induced luciferase activity in a concentration-dependent manner. Overall, our findings suggest that zebrafish RARs may be involved in mediating TPP-induced developmental toxicity, a mechanism of action that may have relevance to humans. PMID:25725299

  7. Cerebrospinal fluid control of neurogenesis induced by retinoic acid during early brain development.

    PubMed

    Alonso, M I; Martín, C; Carnicero, E; Bueno, D; Gato, A

    2011-07-01

    Embryonic-cerebrospinal fluid (E-CSF) plays crucial roles in early brain development including the control of neurogenesis. Although FGF2 and lipoproteins present in the E-CSF have previously been shown to be involved in neurogenesis, the main factor triggering this process remains unknown. E-CSF contains all-trans-retinol and retinol-binding protein involved in the synthesis of retinoic acid (RA), a neurogenesis inducer. In early chick embryo brain, only the mesencephalic-rombencephalic isthmus (IsO) is able to synthesize RA. Here we show that in chick embryo brain development: (1) E-CSF helps to control RA synthesis in the IsO by means of the RBP and all-trans-retinol it contains; (2) E-CSF has retinoic acid activity, which suggests it may act as a diffusion pathway for RA; and (3) the influence of E-CSF on embryonic brain neurogenesis is to a large extent due to its involvement in RA synthesis. These data help to understand neurogenesis from neural progenitor cells. PMID:21594951

  8. Retinoic acid receptor gamma-induced misregulation of chondrogenesis in the murine limb bud in vitro.

    PubMed

    Galdones, Eugene; Hales, Barbara F

    2008-11-01

    Vitamin A derivatives modulate gene expression through retinoic acid and rexinoid receptor (RAR/RXR) heterodimers and are indispensable for limb development. Of particular interest, RARgamma is highly expressed in cartilage, a target affected following retinoid-induced limb insult. The goal of this study was to examine how selective activation of RARgamma affects limb development. Forelimbs from E12.5 CD-1 mice were cultured for 6 days in the presence of all-trans RA (pan-RAR agonist; 0.1 or 1.0 microM) or BMS-189961 (BMS961, RARgamma-selective agonist; 0.01 or 0.1 microM) and limb morphology assessed. Untreated limbs developed normal cartilage elements whereas pan-RAR or RARgamma agonist-treated limbs exhibited reductive effects on chondrogenesis. Retinoid activity was assessed using RAREbeta2 (retinoic acid response element beta2)-lacZ reporter limbs; after 3 h of treatment, both drugs increased retinoid activity proximally. To elucidate the expression profiles of a subset of genes important for development, limbs were cultured for 3 h and cRNA hybridized to osteogenesis-focused microarrays. Two genes, matrix GLA protein (Mgp; chondrogenesis inhibitor) and growth differentiation factor-10 (Gdf10/Bmp3b) were induced by RA and BMS-189961. Real-time PCR was done to validate our results and whole mount in situ hybridizations against Mgp and Gdf10 localized their upregulation to areas of cartilage and programmed cell death, respectively. Thus, our results illustrate the importance of RARgamma in mediating the retinoid-induced upregulation of Mgp and Gdf10; determining their roles in chondrogenesis and cell death will help further unravel mechanisms underlying retinoid teratogenicity. PMID:18703560

  9. AXIAL SKELETAL AND HOX EXPRESSION DOMAIN ALTERATIONS INDUCED BY RETINOIC ACID, VALPROIC ACID AND BROMOXYNIL DURING MURINE DEVELOPMENT

    EPA Science Inventory

    ABSTRACT

    Retinoic acid (RA) alters the developmental fate of the axial skeletal anlage. "Anteriorizations" or "posteriorizations", the assumption of characteristics of embryonic areas normally anterior or posterior to the affected tissues, are correlated with altered emb...

  10. Modulation of ultraviolet light-, ethyl methanesulfonate-, and 7,12-dimethylbenz(A)anthracene-induced unscheduled DNA synthesis by retinol and retinoic acid in the primary rat hepatocyte

    SciTech Connect

    Budroe, J.D.; Shaddock, J.G.; Casciano, D.A.

    1987-01-01

    The effects of retinol and retinoic acid on unscheduled DNA synthesis (UDS) in primary Sprague-Dawley rat hepatocytes were studied in the presence and absence of know chemical and physical mutagens. Neither retinol or retinoic acid caused a significant increase in UDS over solvent control at concentrations ranging from 1 ..mu..M to 50 ..mu..M. Retinol and retinoic acid did not significantly affect 200..mu..g/mL ethyl methanesulfonate (EMS)- or 32 J/m/sup 2/ ultraviolet light (UV)-induced UDS at concentrations ranging from 1..mu..M to 50 ..mu..M. In contrast, retinol and retinoic acid significantly inhibited 2.5 ..mu..g/mL and 5.0 ..mu..g/mL 7,12-dimethyl-benz(a)-anthracene(DMBA)-induced UDS at concentrations of 1..mu..M or greater. Retinol-and retinoic acid-induced hepatocytotoxicity was studied in vitro using lactate dehydrogenase (LDH) release as an indicator of cytoxicity. Neither retinol nor retinoic acid caused significant increases in LDH release over solvent control 3 hours after treatment, whereas retinol caused a biologically significant increase in LDH release 24 hours posttreatment at concentrations of 50 ..mu..M and 100 ..mu..M. These data suggest that nontoxic concentrations of retinol and retinoic acid do not inhibit the DNA excision repair process but apparently affect the effective DNA adduct load due to the ultimate species of DMBA metabolite responsible for hepatocellular DNA damage.

  11. Modulation of ultraviolet light-, ethyl methanesulfonate-, and 7,12-dimethylbenz(a)anthracene-induced unscheduled DNA synthesis by retinol and retinoic acid in the primary rat hepatocyte

    SciTech Connect

    Budroe, J.D.; Shaddock, J.G.; Casciano, D.A.

    1987-01-01

    The effects of retinol and retinoic acid on unscheduled DNA synthesis (UDS) in primary Sprague-Dawley rat hepatocytes were studied in the presence and absence of known chemical and physical mutagens. Neither retinol nor retinoic acid caused a significant increase in UDS over solvent control at concentrations ranging from 1 microM to 50 microM. Retinol and retinoic acid did not significantly affect 200 micrograms/mL ethyl methanesulfonate(EMS)- or 32 J/m2 ultraviolet light(UV)-induced UDS at concentrations ranging from 1 microM to 50 microM. In contrast, retinol and retinoic acid significantly inhibited 2.5 micrograms/mL and 5.0 micrograms/mL 7,12-dimethyl-benz(a)anthracene(DMBA)-induced UDS at concentrations of 1 microM or greater. Retinol- and retinoic acid-induced hepatocytotoxicity was studied in vitro using lactate dehydrogenase (LDH) release as an indicator of cytoxicity. Neither retinol nor retinoic acid caused significant increases in LDH release over solvent control 3 hours after treatment, whereas retinol caused a biologically significant increase in LDH release 24 hours posttreatment at concentrations of 50 microM and 100 microM. These data suggest that nontoxic concentrations of retinol and retinoic acid do not inhibit the DNA excision repair process but apparently affect the effective DNA adduct load due to the ultimate species of DMBA metabolite responsible for hepatocellular DNA damage.

  12. The AhR agonist VAF347 augments retinoic acid-induced differentiation in leukemia cells.

    PubMed

    Ibabao, Christopher N; Bunaciu, Rodica P; Schaefer, Deanna M W; Yen, Andrew

    2015-01-01

    In binary cell-fate decisions, driving one lineage and suppressing the other are conjoined. We have previously reported that aryl hydrocarbon receptor (AhR) promotes retinoic acid (RA)-induced granulocytic differentiation of lineage bipotent HL-60 myeloblastic leukemia cells. VAF347, an AhR agonist, impairs the development of CD14(+)CD11b(+) monocytes from granulo-monocytic (GM) stage precursors. We thus hypothesized that VAF347 propels RA-induced granulocytic differentiation and impairs D3-induced monocytic differentiation of HL-60 cells. Our results show that VAF347 enhanced RA-induced cell cycle arrest, CD11b integrin expression and neutrophil respiratory burst. Granulocytic differentiation is known to be driven by MAPK signaling events regulated by Fgr and Lyn Src-family kinases, the CD38 cell membrane receptor, the Vav1 GEF, the c-Cbl adaptor, as well as AhR, all of which are embodied in a putative signalsome. We found that the VAF347 AhR ligand regulates the signalsome. VAF347 augments RA-induced expression of AhR, Lyn, Vav1, and c-Cbl as well as p47(phox). Several interactions of partners in the signalsome appear to be enhanced: Fgr interaction with c-Cbl, CD38, and with pS259c-Raf and AhR interaction with c-Cbl and Lyn. Thus, we report that, while VAF347 impedes monocytic differentiation induced by 1,25-dihydroxyvitamin D3, VAF347 promotes RA-induced differentiation. This effect seems to involve but not to be limited to Lyn, Vav1, c-Cbl, AhR, and Fgr. PMID:25941627

  13. Impaired Neural Differentiation Potency by Retinoic Acid Receptor-α Pathway Defect in Induced Pluripotent Stem Cells

    PubMed Central

    Hou, Pei-Shan; Huang, Wen-Chin; Chiang, Wei; Lin, Wei-Che

    2014-01-01

    Abstract Induced pluripotent stem cells (iPSCs) are reprogrammed from somatic cells via ectopic gene expression and, similarly to embryonic stem cells (ESCs), possess powerful abilities to self-renew and differentiate into cells of various lineages. However, the neural differentiation potency of iPSCs remains unknown. In this study, we demonstrated the neural differentiation ability of iPSCs compared with ESCs using an retinoic acid (RA) induction system. The neural differentiation efficiency of iPSCs was obviously lower than that of ESCs. Retinoic acid receptor-α (RARα) was critical in the RA-induced neural differentiation of iPSCs, and the effect of RARα was confirmed by applying a specific RARα antagonist ER50891 to ESCs. These findings indicate that iPSCs do not possess the complete properties that ESCs have. PMID:25364979

  14. ERF and ETV3L are retinoic acid-inducible repressors required for primary neurogenesis.

    PubMed

    Janesick, Amanda; Abbey, Rachelle; Chung, Connie; Liu, Sophia; Taketani, Mao; Blumberg, Bruce

    2013-08-01

    Cells in the developing neural tissue demonstrate an exquisite balance between proliferation and differentiation. Retinoic acid (RA) is required for neuronal differentiation by promoting expression of proneural and neurogenic genes. We show that RA acts early in the neurogenic pathway by inhibiting expression of neural progenitor markers Geminin and Foxd4l1, thereby promoting differentiation. Our screen for RA target genes in early Xenopus development identified Ets2 Repressor Factor (Erf) and the closely related ETS repressors Etv3 and Etv3-like (Etv3l). Erf and Etv3l are RA responsive and inhibit the action of ETS genes downstream of FGF signaling, placing them at the intersection of RA and growth factor signaling. We hypothesized that RA regulates primary neurogenesis by inducing Erf and Etv3l to antagonize proliferative signals. Loss-of-function analysis showed that Erf and Etv3l are required to inhibit proliferation of neural progenitors to allow differentiation, whereas overexpression of Erf led to an increase in the number of primary neurons. Therefore, these RA-induced ETS repressors are key components of the proliferation-differentiation switch during primary neurogenesis in vivo. PMID:23824578

  15. Retinoic acid induces Sertoli cell paracrine signals for spermatogonia differentiation but cell autonomously drives spermatocyte meiosis

    PubMed Central

    Raverdeau, Mathilde; Gely-Pernot, Aurore; Féret, Betty; Dennefeld, Christine; Benoit, Gérard; Davidson, Irwin; Chambon, Pierre; Mark, Manuel; Ghyselinck, Norbert B.

    2012-01-01

    Direct evidence for a role of endogenous retinoic acid (RA), the active metabolite of vitamin A in the initial differentiation and meiotic entry of spermatogonia, and thus in the initiation of spermatogenesis is still lacking. RA is synthesized by dedicated enzymes, the retinaldehyde dehydrogenases (RALDH), and binds to and activates nuclear RA receptors (RARA, RARB, and RARG) either within the RA-synthesizing cells or in the neighboring cells. In the present study, we have used a combination of somatic genetic ablations and pharmacological approaches in vivo to show that during the first, prepubertal, spermatogenic cycle (i) RALDH-dependent synthesis of RA by Sertoli cells (SC), the supporting cells of the germ cell (GC) lineage, is indispensable to initiate differentiation of A aligned into A1 spermatogonia; (ii) RARA in SC mediates the effects of RA, possibly through activating Mafb expression, a gene whose Drosophila homolog is mandatory to GC differentiation; (iii) RA synthesized by premeiotic spermatocytes cell autonomously induces meiotic initiation through controlling the RAR-dependent expression of Stra8. Furthermore, we show that RA of SC origin is no longer necessary for the subsequent spermatogenic cycles but essential to spermiation. Altogether, our data establish that the effects of RA in vivo on spermatogonia differentiation are indirect, via SC, but direct on meiotic initiation in spermatocytes, supporting thereby the notion that, contrary to the situation in the female, RA is necessary to induce meiosis in the male. PMID:23012458

  16. Nuclear CD38 in retinoic acid-induced HL-60 cells

    SciTech Connect

    Yalcintepe, Leman . E-mail: lemany@istanbul.edu.tr; Albeniz, Isil; Adin-Cinar, Suzan; Tiryaki, Demir; Bermek, Engin; Graeff, Richard M.; Lee, Hon Cheung

    2005-02-01

    The cell surface antigen, CD38, is a 45-kDa transmembrane protein which is predominantly expressed on hematopoietic cells during differentiation. As a bifunctional ectoenzyme, it catalyzes the synthesis of cyclic ADP-ribose (cADPR) from NAD{sup +} and hydrolysis of either NAD{sup +} or cADPR to ADP-ribose. All-trans-retinoic acid (RA) is a potent and specific inducer of CD38 in myeloid cells. In this report, we demonstrate that the nuclei of RA-treated human HL-60 myeloblastic cells reveal enzymatic activities inherent to CD38. Thus, GDP-ribosyl cyclase and NAD{sup +} glycohydrolase activities in the nuclear fraction increased very significantly in response to incubation with RA. With Western blotting, we detected in the nuclear protein fraction from RA-treated cells a {approx}43-kDa protein band which was reactive with the CD38-specific monoclonal antibody OKT10. The expression of CD38 in HL-60 nuclei was also shown with FACScan analysis. RA treatment gave rise to an increase in in vitro ADP ribosylation of the {approx}43-kDa nuclear protein. Moreover, nuclei isolated from RA-treated HL-60 cells revealed calcium release in response to cADPR, whereas a similar response was not observed in control nuclei. These results suggest that CD38 is expressed in HL-60 cell nuclei during RA-induced differentiation.

  17. Human myeloblastic leukemia cells (HL-60) express a membrane receptor for estrogen that signals and modulates retinoic acid-induced cell differentiation

    SciTech Connect

    Kauss, M. Ariel; Reiterer, Gudrun; Bunaciu, Rodica P.; Yen, Andrew

    2008-10-01

    Estrogen receptors are historically perceived as nuclear ligand activated transcription factors. An estrogen receptor has now been found localized to the plasma membrane of human myeloblastic leukemia cells (HL-60). Its expression occurs throughout the cell cycle, progressively increasing as cells mature from G{sub 1} to S to G{sub 2}/M. To ascertain that the receptor functioned, the effect of ligands, including a non-internalizable estradiol-BSA conjugate and tamoxifen, an antagonist of nuclear estrogen receptor function, were tested. The ligands caused activation of the ERK MAPK pathway. They also modulated the effect of retinoic acid, an inducer of MAPK dependent terminal differentiation along the myeloid lineage in these cells. In particular the ligands inhibited retinoic acid-induced inducible oxidative metabolism, a functional marker of terminal myeloid cell differentiation. To a lesser degree they also diminished retinoic acid-induced earlier markers of cell differentiation, namely CD38 and CD11b. However, they did not regulate retinoic acid-induced G{sub 0} cell cycle arrest. There is thus a membrane localized estrogen receptor in HL-60 myeloblastic leukemia cells that can cause ERK activation and modulates the response of these cells to retinoic acid, indicating crosstalk between the membrane estrogen and retinoic acid evoked pathways relevant to propulsion of cell differentiation.

  18. Human myeloblastic leukemia cells (HL-60) express a membrane receptor for estrogen that signals and modulates retinoic acid-induced cell differentiation.

    PubMed

    Kauss, M Ariel; Reiterer, Gudrun; Bunaciu, Rodica P; Yen, Andrew

    2008-10-01

    Estrogen receptors are historically perceived as nuclear ligand activated transcription factors. An estrogen receptor has now been found localized to the plasma membrane of human myeloblastic leukemia cells (HL-60). Its expression occurs throughout the cell cycle, progressively increasing as cells mature from G(1) to S to G(2)/M. To ascertain that the receptor functioned, the effect of ligands, including a non-internalizable estradiol-BSA conjugate and tamoxifen, an antagonist of nuclear estrogen receptor function, were tested. The ligands caused activation of the ERK MAPK pathway. They also modulated the effect of retinoic acid, an inducer of MAPK dependent terminal differentiation along the myeloid lineage in these cells. In particular the ligands inhibited retinoic acid-induced inducible oxidative metabolism, a functional marker of terminal myeloid cell differentiation. To a lesser degree they also diminished retinoic acid-induced earlier markers of cell differentiation, namely CD38 and CD11b. However, they did not regulate retinoic acid-induced G(0) cell cycle arrest. There is thus a membrane localized estrogen receptor in HL-60 myeloblastic leukemia cells that can cause ERK activation and modulates the response of these cells to retinoic acid, indicating crosstalk between the membrane estrogen and retinoic acid evoked pathways relevant to propulsion of cell differentiation. PMID:18692045

  19. Retinoic acid induces nuclear accumulation of Raf1 during differentiation of HL-60 cells

    SciTech Connect

    Smith, James; Bunaciu, Rodica P.; Reiterer, Gudrun; Coder, David; George, Thaddeus; Asaly, Michael; Yen, Andrew

    2009-08-01

    All trans-retinoic acid (RA) is a standard therapeutic agent used in differentiation induction therapy treatment of acute promyelocytic leukemia (APL). RA and its metabolites use a diverse set of signal transduction pathways during the differentiation program. In addition to the direct transcriptional targets of the nuclear RAR and RXR receptors, signals derived from membrane receptors and the Raf-MEK-ERK pathway are required. Raf1 phosphorylation and the prolonged activation of Raf1 persisting during the entire differentiation process are required for RA-dependent differentiation of HL-60 cells. Here we identify a nuclear redistribution of Raf1 during the RA-induced differentiation of HL-60 cells. In addition, the nuclear accumulation of Raf1 correlates with an increase in Raf1 phosphorylated at serine 621. The serine 621 phosphorylated Raf1 is predominantly localized in the nucleus. The RA-dependent nuclear accumulation of Raf1 suggests a novel nuclear role for Raf1 during the differentiation process.

  20. Epigenomic reorganization of the clustered Hox genes in embryonic stem cells induced by retinoic acid.

    PubMed

    Kashyap, Vasundhra; Gudas, Lorraine J; Brenet, Fabienne; Funk, Patricia; Viale, Agnes; Scandura, Joseph M

    2011-02-01

    Retinoic acid (RA) regulates clustered Hox gene expression during embryogenesis and is required to establish the anterior-posterior body plan. Using mutant embryonic stem cell lines deficient in the RA receptor γ (RARγ) or Hoxa1 3'-RA-responsive element, we studied the kinetics of transcriptional and epigenomic patterning responses to RA. RARγ is essential for RA-induced Hox transcriptional activation, and deletion of its binding site in the Hoxa1 enhancer attenuates transcriptional and epigenomic activation of both Hoxa and Hoxb gene clusters. The kinetics of epigenomic reorganization demonstrate that complete erasure of the polycomb repressive mark H3K27me3 is not necessary to initiate Hox transcription. RARγ is not required to establish the bivalent character of Hox clusters, but RA/RARγ signaling is necessary to erase H3K27me3 from activated Hox genes during embryonic stem cell differentiation. Highly coordinated, long range epigenetic Hox cluster reorganization is closely linked to transcriptional activation and is triggered by RARγ located at the Hoxa1 3'-RA-responsive element. PMID:21087926

  1. Molecular cloning, characterization and expression analysis of woodchuck retinoic acid-inducible gene I.

    PubMed

    Yan, Qi; Liu, Qin; Li, Meng-Meng; Li, Fang-Hui; Zhu, Bin; Wang, Jun-Zhong; Lu, Yin-Ping; Liu, Jia; Wu, Jun; Zheng, Xin; Lu, Meng-Ji; Wang, Bao-Ju; Yang, Dong-Liang

    2016-06-01

    Cytosolic retinoic acid-inducible gene I (RIG-I) is an important innate immune RNA sensor and can induce antiviral cytokines, e.g., interferon-β (IFN-β). Innate immune response to hepatitis B virus (HBV) plays a pivotal role in viral clearance and persistence. However, knowledge of the role that RIG-I plays in HBV infection is limited. The woodchuck is a valuable model for studying HBV infection. To characterize the molecular basis of woodchuck RIG-I (wRIG-I), we analyzed the complete coding sequences (CDSs) of wRIG-I, containing 2778 base pairs that encode 925 amino acids. The deduced wRIG-I protein was 106.847 kD with a theoretical isoelectric point (pI) of 6.07, and contained three important functional structures [caspase activation and recruitment domains (CARDs), DExD/H-box helicases, and a repressor domain (RD)]. In woodchuck fibroblastoma cell line (WH12/6), wRIG-I-targeted small interfering RNA (siRNA) down-regulated RIG-I and its downstrean effector-IFN-β transcripts under RIG-I' ligand, 5'-ppp double stranded RNA (dsRNA) stimulation. We also measured mRNA levels of wRIG-I in different tissues from healthy woodchucks and in the livers from woodchuck hepatitis virus (WHV)-infected woodchucks. The basal expression levels of wRIG-I were abundant in the kidney and liver. Importantly, wRIG-I was significantly up-regulated in acutely infected woodchuck livers, suggesting that RIG-I might be involved in WHV infection. These results may characterize RIG-I in the woodchuck model, providing a strong basis for further study on RIG-I-mediated innate immunity in HBV infection. PMID:27376800

  2. Effect of All-Trans Retinoic Acid on the Pancreas of Streptozotocin-Induced Diabetic Rat.

    PubMed

    Eltony, Sohair A; Elmottaleb, Nashwa A; Gomaa, Asmaa M; Anwar, Mamdouh M; El-Metwally, Tarek H

    2016-03-01

    All-trans Retinoic acid (atRA) is instructive for the development of endocrine pancreas and is an integral component of β-cell induction protocols. We showed that atRA induces glucose-responsive endocrine transdifferentiation of pleomorphic pancreatic ductal adenocarcinoma cells in vitro. This study aimed to detect the role of atRA in improving the histological changes of the pancreas in diabetic rats. Forty young male Wistar rats were used and divided into three groups. Group I: normal vehicle control (N = 5). Group II: streptozotocin-induced diabetic rats (N = 20) were followed up at 0.0, 1, 2, and 4 weeks. Group III: streptozotocin-induced diabetic rats (N = 15) treated with atRA (2.5 mg/kg/day), were followed up at 1, 2, and 4 weeks. Specimens from the pancreas were processed for light, electron microscopy and pancreatic insulin mRNA expression. Blood samples were assayed for the levels of glucose, insulin, and total peroxides. In the atRA-treated group, the number of the islets and the islet area significantly increased. Strong insulin-immunoreactive endocrine-like cells were observed nearby the pancreatic acini and the interlobular ducts. Interestingly, insulin-positive cells seemed to arise from pancreatic acinar and ductal epithelium. Ultrastructurally, ß-cells, acinar, and ductal cells restored their normal appearance. Pancreatic insulin mRNA and blood indices were almost normalized. AtRA improved the histological changes of the pancreas and the blood indices in diabetic rats. PMID:26704900

  3. Modeling and analysis of retinoic acid induced differentiation of uncommitted precursor cells†

    PubMed Central

    Tasseff, Ryan; Nayak, Satyaprakash; Song, Sang Ok; Yen, Andrew; Varner, Jeffrey D.

    2013-01-01

    Manipulation of differentiation programs has therapeutic potential in a spectrum of human cancers and neurodegenerative disorders. In this study, we integrated computational and experimental methods to unravel the response of a lineage uncommitted precursor cell-line, HL-60, to Retinoic Acid (RA). HL-60 is a human myeloblastic leukemia cell-line used extensively to study human differentiation programs. Initially, we focused on the role of the BLR1 receptor in RA-induced differentiation and G1/0-arrest in HL-60. BLR1, a putative G protein-coupled receptor expressed following RA exposure, is required for RA-induced cell-cycle arrest and differentiation and causes persistent MAPK signaling. A mathematical model of RA-induced cell-cycle arrest and differentiation was formulated and tested against BLR1 wild-type (wt) knock-out and knock-in HL-60 cell-lines with and without RA. The current model described the dynamics of 729 proteins and protein complexes interconnected by 1356 interactions. An ensemble strategy was used to compensate for uncertain model parameters. The ensemble of HL-60 models recapitulated the positive feedback between BLR1 and MAPK signaling. The ensemble of models also correctly predicted Rb and p47phox regulation and the correlation between p21-CDK4-cyclin D formation and G1/0-arrest following exposure to RA. Finally, we investigated the robustness of the HL-60 network architecture to structural perturbations and generated experimentally testable hypotheses for future study. Taken together, the model presented here was a first step toward a systematic framework for analysis of programmed differentiation. These studies also demonstrated that mechanistic network modeling can help prioritize experimental directions by generating falsifiable hypotheses despite uncertainty. PMID:21437295

  4. Retinoic acid alone and in combination with cytosine arabinoside induces differentiation of human myelomonocytic and monoblastic leukaemic cells.

    PubMed

    Hassan, H T; Rees, J K

    1988-01-01

    The effect of retinoic acid (RA) alone and in combination with cytosine arabinoside (Ara-C) on differentiation of fresh human myeloid leukaemic cells from patients with AML was studied. Cells from six patients: three with acute myelomonocytic leukaemia AMMoL and three with acute monoblastic leukaemia AMoL with a percentage of blasts greater than 70, were treated in an in vitro primary suspension culture with retinoic acid (10(-7) M), cytosine arabinoside (100 ng/ml) or both in combination. Non-adherent mononuclear cells were seeded at a concentration of 5 x 10(5) cells/ml in RPMI 1640 culture medium supplemented with 20 per cent fetal bovine serum and 10 per cent (PHA-LCM) phytohaemagglutinin leucocyte conditioned medium and incubated for 6 days at 37 degrees C in a humidified incubator containing 5 per cent CO2 in air. Morphological and functional differentiation into terminal mature elements was induced in all leukaemia cells of the six patients following exposure to the combination of both agents. These results suggest the potential usefulness of the combination of a differentiating agent (retinoic acid) and an antileukaemic drug (cytosine arabinoside) in the treatment of acute myeloid leukaemias: AMMoL and AMoL. This combination warrants a clinical trial. PMID:3422632

  5. Comparative molecular pathology of cadmium- and all-trans-retinoic acid-induced postaxial forelimb ectrodactyly

    SciTech Connect

    Liao Xiaoyan; Lee, Grace S.; Shimizu, Hirohito; Collins, Michael D.

    2007-11-15

    Cadmium chloride (CdCl{sub 2}) and all-trans-retinoic acid (RA) induce postaxial forelimb ectrodactyly in C57BL/6N mice when administered during early limb development, and co-administration yields a synergistic response suggesting a common final pathway to the defect. In the current study, forelimb buds from embryos given high maternal teratogenic doses of CdCl{sub 2} or RA, or the combination of both agents at low doses were collected at various time points after treatment on GD 9.5 and examined for cellular apoptosis, proliferation, and patterning genes. Some cellular perturbations detected in the developing limb bud were similar for both teratogens, whereas other alterations were unique to each agent. For example, at 12 and 18 h, CdCl{sub 2} treatment increased apoptotic cells in the mesenchyme underneath the apical ectodermal ridge (AER), whereas RA caused apoptosis in the AER and proximal mesenchyme. Further, the combined low-dose treatment increased cell death synergistically in all three regions. CdCl{sub 2} and the low-dose combined treatment inhibited mesenchymal proliferation at 12 h, which was associated with induction of p21{sup cip1} and inhibition of phospho-c-Jun. In contrast, RA did not inhibit mesenchymal proliferation and did not induce p21{sup cip1} expression or change c-Jun phosphorylation. All three treatment groups showed a delay in the patterning of distal chondrogenesis centers as indicated by Sox9 expression. There was also common inhibition in the expression of AER markers, Fgf8 and Fgf4, and the mesenchymal marker Msx1 involved in the maintenance of epithelial-mesenchymal interactions. Collectively, a model is hypothesized where limb patterning can be perturbed by insults to both ectoderm and mesoderm.

  6. A novel model of in vitro osteocytogenesis induced by retinoic acid treatment.

    PubMed

    Mattinzoli, D; Messa, P; Corbelli, A; Ikehata, M; Zennaro, C; Armelloni, S; Li, M; Giardino, L; Rastaldi, M P

    2012-01-01

    Despite recent research which more and more stresses the importance of osteocytes in regulating bone and systemic mineral metabolism, current molecular and functional knowledge of osteocyte properties are still incomplete, mostly due to limited availability of in vitro models. Osteocytes are terminally differentiated dendritic cells, and therefore are not easy to obtain and maintain in primary cultures. As an alternative, osteocyte differentiation can be induced by progressive osteoblast embedding in mineralised extracellular matrix. In this model, which is suitable for reproduction of bone development, the presence of calcified matrix prevents several cell biological methods from being used. Therefore, the osteocyte-like MLO-Y4 cell line continues to be the most widely used cellular system. Here we show that treatment of primary osteoblasts or MC3T3-E1 cells with retinoic acid generates a homogeneous population of ramified cells with osteocyte features, as confirmed by morphological and molecular analyses. The first morphological changes are detectable in primary cells after 2 days of treatment, and in the cell line after 4 days of treatment. Differentiation is complete in 5 and 10 days, respectively, with progressive development of dendrites, loss of the ability to produce extracellular matrix, down-regulation of osteoblast markers, and up-regulation of osteocyte-specific molecules, most notably among them sclerostin. Compared to other published protocols, our method has a number of advantages. It is easy to perform and does not require special instrumentation, it is highly reproducible, and rapidly generates a mature osteocyte population in the complete absence of extracellular matrix, allowing the use of these cells for unlimited biological applications. PMID:23160992

  7. Pathways through which a regimen of melatonin and retinoic acid induces apoptosis in MCF-7 human breast cancer cells.

    PubMed

    Eck-Enriquez, K; Kiefer, T L; Spriggs, L L; Hill, S M

    2000-06-01

    It has been established that melatonin (Mlt) and retinoic acid, individually, inhibit the proliferation of the estrogen receptor-alpha (ER alpha)-positive MCF-7 breast cancer cell line. Our laboratory has previously demonstrated that Mlt and all-trans-retinoic acid (atRA) not only inhibit the proliferation, but also induce apoptosis of MCF-7 cells when used in a sequential regimen of Mlt followed 24 h later by atRA. Using this same MCF-7 breast cancer cell line, we investigated the potential pathways through which apoptosis is being induced. We found that treatment of MCF-7 cells with Mlt for 24 h before the addition of atRA decreased the protein levels of the death suppressor, Bcl-2, and increased, although with different time courses, the levels of the death promoters, Bax and Bak; however, there was no change in the levels of the tumor suppressor gene, p53. MCF-7 cells treated sequentially with Mlt and atRA also demonstrated an enhanced sensitivity to the apoptotic effects of atRA, which did not appear to be due to increased expression of the retinoic acid receptors, RAR alpha or RXR alpha, but rather to enhanced transcriptional activity of the RAR alpha. These data suggest that the sequential treatment regimen of Mlt and atRA may induce apoptosis by modulation of members of the Bcl-2 family of proteins. Thus, this combinatorial regimen, which reduces the concentration of atRA needed for clinical efficacy while enhancing its anti-tumorigenic activity, could be of great therapeutic benefit, and may, in fact, specifically induce the regression of established breast tumors due to its apoptosis-promoting effects. PMID:10965999

  8. Retinoic acid induced the differentiation of neural stem cells from embryonic spinal cord into functional neurons in vitro

    PubMed Central

    Tan, Bo-Tao; Wang, Li; Li, Sen; Long, Zai-Yun; Wu, Ya-Min; Liu, Yuan

    2015-01-01

    Retinoic acid is an important molecular taking part in the development and homeostasis of nervous system. Neural stem cells (NSCs) are pluripotent cells that can differentiate into three main neural cells including neuron, astrocyte and oligodendrocyte. However, whether retinoic acid can induce NSCs derived from embryonic spinal cord differentiating into functional neurons and its efficiency are not clear. In this experiment, NSCs were isolated from embryonic 14 d spinal cord of rats. The growth and neuronal differentiation of NSCs induced by 500 nM RA was examined in vitro. It was indicated that compared with the control group, there were more differentiated cells with longer cytodendrites in the medium treated with RA at different time. And more, there were more neuronal marker positive cells in 500 nM RA group than the control group seven days after differentiation. At the same time, the expression of β-tublin III protein in RA group was higher than those in control group, which was contrary to the expression of astrocyte marker GFAP protein at seven days after differentiation. However the differentiated neurons, whether treated with RA or not both exhibited biological electrical reactivity after stimulated by glutamine. Therefore, these findings indicated that RA could promote growth of cellular dendrites and neuronal differentiation of NSCs, which also induce functional maturation of differentiated neurons finally. PMID:26339381

  9. Interactions between the Influenza A Virus RNA Polymerase Components and Retinoic Acid-Inducible Gene I

    PubMed Central

    Li, Weizhong; Chen, Hongjun; Sutton, Troy; Obadan, Adebimpe

    2014-01-01

    ABSTRACT The influenza A virus genome possesses eight negative-strand RNA segments in the form of viral ribonucleoprotein particles (vRNPs) in association with the three viral RNA polymerase subunits (PB2, PB1, and PA) and the nucleoprotein (NP). Through interactions with multiple host factors, the RNP subunits play vital roles in replication, host adaptation, interspecies transmission, and pathogenicity. In order to gain insight into the potential roles of RNP subunits in the modulation of the host's innate immune response, the interactions of each RNP subunit with retinoic acid-inducible gene I protein (RIG-I) from mammalian and avian species were investigated. Studies using coimmunoprecipitation (co-IP), bimolecular fluorescence complementation (BiFc), and colocalization using confocal microscopy provided direct evidence for the RNA-independent binding of PB2, PB1, and PA with RIG-I from various hosts (human, swine, mouse, and duck). In contrast, the binding of NP with RIG-I was found to be RNA dependent. Expression of the viral NS1 protein, which interacts with RIG-I, did not interfere with the association of RNA polymerase subunits with RIG-I. The association of each individual virus polymerase component with RIG-I failed to significantly affect the interferon (IFN) induction elicited by RIG-I and 5′ triphosphate (5′ppp) RNA in reporter assays, quantitative reverse transcription-PCR (RT-PCR), and IRF3 phosphorylation tests. Taken together, these findings indicate that viral RNA polymerase components PB2, PB1, and PA directly target RIG-I, but the exact biological significance of these interactions in the replication and pathogenicity of influenza A virus needs to be further clarified. IMPORTANCE RIG-I is an important RNA sensor to elicit the innate immune response in mammals and some bird species (such as duck) upon influenza A virus infection. Although the 5′-triphosphate double-stranded RNA (dsRNA) panhandle structure at the end of viral genome RNA is

  10. Mouse GATA-4: a retinoic acid-inducible GATA-binding transcription factor expressed in endodermally derived tissues and heart.

    PubMed Central

    Arceci, R J; King, A A; Simon, M C; Orkin, S H; Wilson, D B

    1993-01-01

    We report the cDNA cloning and characterization of mouse GATA-4, a new member of the family of zinc finger transcription factors that bind a core GATA motif. GATA-4 cDNA was identified by screening a 6.5-day mouse embryo library with oligonucleotide probes corresponding to a highly conserved region of the finger domains. Like other proteins of the family, GATA-4 is approximately 50 kDa in size and contains two zinc finger domains of the form C-X-N-C-(X17)-C-N-X-C. Cotransfection assays in heterologous cells demonstrate that GATA-4 trans activates reporter constructs containing GATA promoter elements. Northern (RNA) analysis and in situ hybridization show that GATA-4 mRNA is expressed in the heart, intestinal epithelium, primitive endoderm, and gonads. Retinoic acid-induced differentiation of mouse F9 cells into visceral or parietal endoderm is accompanied by increased expression of GATA-4 mRNA and protein. In vitro differentiation of embryonic stem cells into embryoid bodies is also associated with increased GATA-4 expression. We conclude that GATA-4 is a tissue-specific, retinoic acid-inducible, and developmentally regulated transcription factor. On the basis of its tissue distribution, we speculate that GATA-4 plays a role in gene expression in the heart, intestinal epithelium, primitive endoderm, and gonads. Images PMID:8455608

  11. Evolution of retinoic acid receptors and retinoic acid signaling.

    PubMed

    Gutierrez-Mazariegos, Juliana; Schubert, Michael; Laudet, Vincent

    2014-01-01

    Retinoic acid (RA) is a vitamin A-derived morphogen controlling important developmental processes in vertebrates, and more generally in chordates, including axial patterning and tissue formation and differentiation. In the embryo, endogenous RA levels are controlled by RA synthesizing and degrading enzymes and the RA signal is transduced by two retinoid receptors: the retinoic acid receptor (RAR) and the retinoid X receptor (RXR). Both RAR and RXR are members of the nuclear receptor superfamily of ligand-activated transcription factors and mainly act as heterodimers to activate the transcription of target genes in the presence of their ligand, all-trans RA. This signaling pathway was long thought to be a chordate innovation, however, recent findings of gene homologs involved in RA signaling in the genomes of a wide variety of non-chordate animals, including ambulacrarians (sea urchins and acorn worms) and lophotrochozoans (annelids and mollusks), challenged this traditional view and suggested that the RA signaling pathway might have a more ancient evolutionary origin than previously thought. In this chapter, we discuss the evolutionary history of the RA signaling pathway, and more particularly of the RARs, which might have experienced independent gene losses and duplications in different animal lineages. In sum, the available data reveal novel insights into the origin of the RA signaling pathway as well as into the evolutionary history of the RARs. PMID:24962881

  12. RIPPLY3 is a retinoic acid-inducible repressor required for setting the borders of the pre-placodal ectoderm

    PubMed Central

    Janesick, Amanda; Shiotsugu, Jason; Taketani, Mao; Blumberg, Bruce

    2012-01-01

    Retinoic acid signaling is a major component of the neural posteriorizing process in vertebrate development. Here, we identify a new role for the retinoic acid receptor (RAR) in the anterior of the embryo, where RAR regulates Fgf8 expression and formation of the pre-placodal ectoderm (PPE). RARα2 signaling induces key pre-placodal genes and establishes the posterolateral borders of the PPE. RAR signaling upregulates two important genes, Tbx1 and Ripply3, during early PPE development. In the absence of RIPPLY3, TBX1 is required for the expression of Fgf8 and hence, PPE formation. In the presence of RIPPLY3, TBX1 acts as a transcriptional repressor, and functions to restrict the positional expression of Fgf8, a key regulator of PPE gene expression. These results establish a novel role for RAR as a regulator of spatial patterning of the PPE through Tbx1 and RIPPLY3. Moreover, we demonstrate that Ripply3, acting downstream of RAR signaling, is a key player in establishing boundaries in the PPE. PMID:22354841

  13. Regulation of Retinoic Acid Inducible Gene-I (RIG-I) Activation by the Histone Deacetylase 6.

    PubMed

    Liu, Helene Minyi; Jiang, Fuguo; Loo, Yueh Ming; Hsu, ShuZhen; Hsiang, Tien-Ying; Marcotrigiano, Joseph; Gale, Michael

    2016-07-01

    Retinoic acid inducible gene-I (RIG-I) is a cytosolic pathogen recognition receptor that initiates the immune response against many RNA viruses. Upon RNA ligand binding, RIG-I undergoes a conformational change facilitating its homo-oligomerization and activation that results in its translocation from the cytosol to intracellular membranes to bind its signaling adaptor protein, mitochondrial antiviral-signaling protein (MAVS). Here we show that RIG-I activation is regulated by reversible acetylation. Acetyl-mimetic mutants of RIG-I do not form virus-induced homo-oligomers, revealing that acetyl-lysine residues of the RIG-I repressor domain prevent assembly to active homo-oligomers. During acute infection, deacetylation of RIG-I promotes its oligomerization upon ligand binding. We identify histone deacetylase 6 (HDAC6) as the deacetylase that promotes RIG-I activation and innate antiviral immunity to recognize and restrict RNA virus infection. PMID:27372014

  14. Retinoic acid affects calcium signaling in adult molluscan neurons.

    PubMed

    Vesprini, Nicholas D; Dawson, Taylor F; Yuan, Ye; Bruce, Doug; Spencer, Gaynor E

    2015-01-01

    Retinoic acid, the active metabolite of vitamin A, is important for nervous system development, regeneration, as well as cognitive functions of the adult central nervous system. These central nervous system functions are all highly dependent on neuronal activity. Retinoic acid has previously been shown to induce changes in the firing properties and action potential waveforms of adult molluscan neurons in a dose- and isomer-dependent manner. In this study, we aimed to determine the cellular pathways by which retinoic acid might exert such effects, by testing the involvement of pathways previously shown to be affected by retinoic acid. We demonstrated that the ability of all-trans retinoic acid (atRA) to induce electrophysiological changes in cultured molluscan neurons was not prevented by inhibitors of protein synthesis, protein kinase A or phospholipase C. However, we showed that atRA was capable of rapidly reducing intracellular calcium levels in the same dose- and isomer-dependent manner as shown previously for changes in neuronal firing. Moreover, we also demonstrated that the transmembrane ion flux through voltage-gated calcium channels was rapidly modulated by retinoic acid. In particular, the peak current density was reduced and the inactivation rate was increased in the presence of atRA, over a similar time course as the changes in cell firing and reductions in intracellular calcium. These studies provide further evidence for the ability of atRA to induce rapid effects in mature neurons. PMID:25343782

  15. All-trans retinoic acid induces oxidative phosphorylation and mitochondria biogenesis in adipocytes[S

    PubMed Central

    Tourniaire, Franck; Musinovic, Hana; Gouranton, Erwan; Astier, Julien; Marcotorchino, Julie; Arreguin, Andrea; Bernot, Denis; Palou, Andreu; Bonet, M. Luisa; Ribot, Joan; Landrier, Jean-François

    2015-01-01

    A positive effect of all-trans retinoic acid (ATRA) on white adipose tissue (WAT) oxidative and thermogenic capacity has been described and linked to an in vivo fat-lowering effect of ATRA in mice. However, little is known about the effects of ATRA on mitochondria in white fat. Our objective has been to characterize the effect of ATRA on mitochondria biogenesis and oxidative phosphorylation (OXPHOS) capacity in mature white adipocytes. Transcriptome analysis, oxygraphy, analysis of mitochondrial DNA (mtDNA), and flow cytometry-based analysis of mitochondria density were performed in mature 3T3-L1 adipocytes after 24 h incubation with ATRA (2 µM) or vehicle. Selected genes linked to mitochondria biogenesis and function and mitochondria immunostaining were analyzed in WAT tissues of ATRA-treated as compared with vehicle-treated mice. ATRA upregulated the expression of a large set of genes linked to mtDNA replication and transcription, mitochondrial biogenesis, and OXPHOS in adipocytes, as indicated by transcriptome analysis. Oxygen consumption rate, mtDNA content, and staining of mitochondria were increased in the ATRA-treated adipocytes. Similar results were obtained in WAT depots of ATRA-treated mice. We conclude that ATRA impacts mitochondria in adipocytes, leading to increased OXPHOS capacity and mitochondrial content in these cells. PMID:25914170

  16. Retinoic acid induces nuclear FAK translocation and reduces breast cancer cell adhesion through Moesin, FAK, and Paxillin.

    PubMed

    Sanchez, Angel Matías; Shortrede, Jorge Eduardo; Vargas-Roig, Laura María; Flamini, Marina Inés

    2016-07-15

    Breast cancer is the most common malignancy in women, with metastases being the cause of death in 98%. In previous works we have demonstrated that retinoic acid (RA), the main retinoic acid receptor (RAR) ligand, is involved in the metastatic process by inhibiting migration through a reduced expression of the specific migration-related proteins Moesin, c-Src, and FAK. At present, our hypothesis is that RA also acts for short periods in a non-genomic action to cooperate with motility reduction and morphology of breast cancer cells. Here we identify that the administration of 10(-6) M RA (10-20 min) induces the activation of the migration-related proteins Moesin, FAK, and Paxillin in T-47D breast cancer cells. The phosphorylation exerted by the selective agonists for RARα and RARβ, on Moesin, FAK, and Paxillin was comparable to the activation exerted by RA. The RARγ agonist only led to a weak activation, suggesting the involvement of RARα and RARβ in this pathway. We then treated the cells with different inhibitors that are involved in cell signaling to regulate the mechanisms of cell motility. RA failed to activate Moesin, FAK, and Paxillin in cells treated with Src inhibitor (PP2) and PI3K inhibitor (WM), suggesting the participation of Src-PI3K in this pathway. Treatment with 10(-6) M RA for 20 min significantly decreased cell adhesion. However, when cells were treated with 10(-6) M RA and FAK inhibitor, the RA did not significantly inhibit adhesion, suggesting a role of FAK in the adhesion inhibited by RA. By immunofluorescence and immunoblotting analysis we demonstrated that RA induced nuclear FAK translocation leading to a reduced cellular adhesion. These findings provide new information on the actions of RA for short periods. RA participates in cell adhesion and subsequent migration, modulating the relocation and activation of proteins involved in cell migration. PMID:27130522

  17. Acidic leucine-rich nuclear phosphoprotein 32 family member B (ANP32B) contributes to retinoic acid-induced differentiation of leukemic cells

    SciTech Connect

    Yu, Yun; Shen, Shao-Ming; Zhang, Fei-Fei; Wu, Zhao-Xia; Han, Bin; Wang, Li-Shun

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer ANP32B was down-regulated during ATRA-induced leukemic cell differentiation. Black-Right-Pointing-Pointer Knockdown of ANP32B enhanced ATRA-induced leukemic cell differentiation. Black-Right-Pointing-Pointer Ectopic expression of ANP32B inhibited ATRA-induced leukemic cell differentiation. Black-Right-Pointing-Pointer ANP32B inhibited ATRA activated transcriptional activity of RAR{alpha}. -- Abstract: The acidic leucine-rich nuclear phosphoprotein 32B (ANP32B) is a member of a conserved superfamily of nuclear proteins whose functions are largely unknown. In our previous work, ANP32B was identified as a novel direct substrate for caspase-3 and acted as a negative regulator for leukemic cell apoptosis. In this work, we provided the first demonstration that ANP32B expression was down-regulated during differentiation induction of leukemic cells by all-trans retinoic acid (ATRA). Knockdown of ANP32B expression by specific shRNA enhanced ATRA-induced leukemic cell differentiation, while ectopic expression of ANP32B attenuated it, indicating an inhibitory role of ANP32B against leukemic cell differentiation. Furthermore, luciferase reporter assay revealed that ANP32B might exert this role through inhibiting the ATRA dependent transcriptional activity of retinoic acid receptor (RAR{alpha}). These data will shed new insights into understanding the biological functions of ANP32B protein.

  18. MicroRNA gene expression during retinoic acid-induced differentiation of human acute promyelocytic leukemia.

    PubMed

    Garzon, R; Pichiorri, F; Palumbo, T; Visentini, M; Aqeilan, R; Cimmino, A; Wang, H; Sun, H; Volinia, S; Alder, H; Calin, G A; Liu, C-G; Andreeff, M; Croce, C M

    2007-06-14

    MicroRNAs (miRNAs) are small non-coding RNAs of 19-25 nucleotides that are involved in the regulation of critical cell processes such as apoptosis, cell proliferation and differentiation. However, little is known about the role of miRNAs in granulopoiesis. Here, we report the expression of miRNAs in acute promyelocytic leukemia patients and cell lines during all-trans-retinoic acid (ATRA) treatment by using a miRNA microarrays platform and quantitative real time-polymerase chain reaction (qRT-PCR). We found upregulation of miR-15a, miR-15b, miR-16-1, let-7a-3, let-7c, let-7d, miR-223, miR-342 and miR-107, whereas miR-181b was downregulated. Among the upregulated miRNAs, miR-107 is predicted to target NFI-A, a gene that has been involved in a regulatory loop involving miR-223 and C/EBPa during granulocytic differentiation. Indeed, we have confirmed that miR-107 targets NF1-A. To get insights about ATRA regulation of miRNAs, we searched for ATRA-modulated transcription factors binding sites in the upstream genomic region of the let-7a-3/let-7b cluster and identified several putative nuclear factor-kappa B (NF-kappaB) consensus elements. The use of reporter gene assays, chromatin immunoprecipitation and site-directed mutagenesis revealed that one proximal NF-kappaB binding site is essential for the transactivation of the let-7a-3/let-7b cluster. Finally, we show that ATRA downregulation of RAS and Bcl2 correlate with the activation of known miRNA regulators of those proteins, let-7a and miR-15a/miR-16-1, respectively. PMID:17260024

  19. Retinoic acid induces homing of protective T and B cells to the gut after subcutaneous immunization in mice.

    PubMed

    Hammerschmidt, Swantje I; Friedrichsen, Michaela; Boelter, Jasmin; Lyszkiewicz, Marcin; Kremmer, Elisabeth; Pabst, Oliver; Förster, Reinhold

    2011-08-01

    Diarrheal diseases represent a major health burden in developing countries. Parenteral immunization typically does not induce efficient protection against enteropathogens because it does not stimulate migration of immune cells to the gut. Retinoic acid (RA) is critical for gut immunity, inducing upregulation of gut-homing receptors on activated T cells. In this study, we have demonstrated that RA can redirect immune responses elicited by s.c. vaccination of mice from skin-draining inguinal LNs (ingLNs) to the gut. When present during priming, RA induced robust upregulation of gut-homing receptors in ingLNs, imprinting gut-homing capacity on T cells. Concurrently, RA triggered the generation of gut-tropic IgA+ plasma cells in ingLNs and raised the levels of antigen-specific IgA in the intestinal lumen and blood. RA applied s.c. in vivo induced autonomous RA production in ingLN DCs, further driving efficient induction of gut-homing molecules on effector cells. Importantly, RA-supplemented s.c. immunization elicited a potent immune response in the small intestine that protected mice from cholera toxin–induced diarrhea and diminished bacterial loads in Peyer patches after oral infection with Salmonella. Thus, the use of RA as a gut-homing navigator represents a powerful tool to induce protective immunity in the intestine after s.c. immunization, offering what we believe to be a novel approach for vaccination against enteropathogens. PMID:21737878

  20. Elevated TrkA receptor expression is associated with all-trans retinoic acid-induced neuroblastoma differentiation.

    PubMed

    Gao, Q; Chen, C F; Dong, Q; Hou, L; Chen, X; Zhi, Y L; Li, X; Lu, H T; Zhang, H Y

    2015-01-01

    Neuroblastoma is the most common and one of the deadliest among pediatric tumors; however, a subset of infants with neuroblastoma display spontaneous regression. The mechanism of spontaneous regression remains to be elucidated. TrkA plays an essential role in the differentiation and functionality of neurons; abundant TrkA expression is associated with favorable prognosis of neuroblastoma. All-trans retinoic acid (ATRA), a first-line drug for acute promyelocytic leukemia (APL) treatment, has been shown to induce differentiation and inhibit cell growth. Neuroblastoma tissues in our hospital inpatient were collected, primary cell culture was performed, and the cells were separated and purified to be cell line. Trypan blue exclusion was used to count the numbers of cells alive, morphological changes were observed under the phase-contrast microscope. RT-PCR was used to determine the expression level of TrkA. In this study, a human neuroblastoma cell line was successfully established; in addition, we demonstrated that ATRA induces growth arrest and promotes the differentiation of neuroblastoma cells. In addition, ATRA was shown to significantly increase the levels of TrkA mRNA expression. Therefore, we concluded that the elevated expression of the TrkA receptor is associated with ATRA-induced growth arrest and differentiation o neuroblastoma cells. The results of this study provide a theoretical basis for the clinical application of differentiation-inducing ATRA for neuroblastoma therapy. PMID:26535632

  1. c-myc regulation during retinoic acid-induced differentiation of F9 cells is posttranscriptional and associated with growth arrest.

    PubMed Central

    Dean, M; Levine, R A; Campisi, J

    1986-01-01

    We have shown that c-myc mRNA levels decrease more than 20-fold when F9 teratocarcinoma stem cells are induced to arrest growth and terminally differentiate to parietal endoderm after exposure to retinoic acid and cyclic AMP (Campisi et al., Cell 36:241-247, 1984). Here, we demonstrate that although growth arrest and full expression of the differentiated phenotype required about 3 days, c-myc mRNA declined abruptly between 8 and 16 h after the addition of retinoic acid and cyclic AMP. The decline was independent of cyclic AMP. We found little or no change in the level of c-myc transcription during differentiation, although two other genes showed marked transcriptional regulation. Thus, decreased c-myc mRNA is a consequence of very early posttranscriptional regulation directed by retinoic acid. Differentiation was not fundamental to this regulation. We have shown that sodium butyrate blocks expression of the differentiated phenotype if added within 8 h of retinoic acid and cyclic AMP (Levine et al., Dev. Biol. 105:443-450, 1984). However, butyrate did not inhibit the decrease in c-myc mRNA. Furthermore, F9 cells partially arrested growth without differentiating when grown in isoleucine-deficient medium. Under these conditions, c-myc mRNA levels also declined. Our results suggest that induction of differentiation-specific genes may be under retinoic acid-mediated control dissimilar from that responsible for the decay of c-myc mRNA. In addition, they raise the possibility that growth arrest may be initiated by reduced c-myc expression. Images PMID:3785153

  2. Unexpected phenotypes of malformations induced in Xenopus tropicalis embryos by combined exposure to triphenyltin and 9-cis-retinoic acid.

    PubMed

    Zhu, Jingmin; Yu, Lin; Wu, Lijiao; Hu, Lingling; Shi, Huahong

    2014-03-01

    Xenopus tropicalis embryos were exposed for 48 hr to the mixtures of 5 μg Sn/L triphenyltin (TPT), which is a well-known endocrine disruptor, and 0.25-5 μg/L 9-cis retinoic acid (9c-RA), which is the natural ligand of retinoid X receptor. The phenotypes induced by combined exposure were more variable than those resulting from single exposure to either TPT or 9c-RA. The prominent phenotypes included underdeveloped head structures, abnormal eyes, narrow fins, enlarged proctodaeum, etc. Especially, combined exposure induced unexpected notochord malformations, which ranged from small swellings of the surface of the tails to the extension and extrusion of notochord out of the posterior tails. Compared with the 5 μg Sn/L TPT-treated group, the index of fin deficiency was not affected, and the index of axis deficiency was significantly increased with increasing RA concentrations in the mixtures. Our results suggest that combined exposure to TPT and 9c-RA induced not only more variable phenotypes of malformations than exposure to single compound but also some new and unexpected phenotypes. PMID:25079278

  3. Cholinergic activation enhances retinoic acid-induced differentiation in the human NB-4 acute promyelocytic leukemia cell line.

    PubMed

    Chotirat, Sadudee; Suriyo, Tawit; Hokland, Marianne; Hokland, Peter; Satayavivad, Jutamaad; Auewarakul, Chirayu U

    2016-07-01

    The non-neuronal cholinergic system (NNCS) has been shown to play a role in regulating hematopoietic differentiation. We determined the expression of cholinergic components in leukemic cell lines by Western blotting and in normal leukocyte subsets by flow cytometry and found a heterogeneous expression of choline acetyltransferase (ChAT), acetylcholinesterase (AChE), choline transporter (CHT), M3 muscarinic acetylcholine receptor (M3-mAChR) and α7 nicotinic acetylcholine receptor (α7-nAChR). We then evaluated NNCS role in differentiation of human NB-4 acute promyelocytic leukemia cell line and discovered a dramatic induction of M3-mAChR after all-trans retinoic acid (ATRA) treatment (p<0.0001). Adding carbachol which is a cholinergic agonist to the ATRA treatment resulted in an increase of a granulocytic differentiation marker (CD11b) as compared with ATRA treatment alone (p<0.05), indicating that cholinergic activation enhanced ATRA in inducing NB-4 maturation. The combination of carbachol and ATRA treatment for 72h also resulted in decreased viability and increased cleaved caspase-3 expression when compared with ATRA treatment alone (p<0.05). However, this combination did not cause poly (ADP-ribose) polymerase (PARP) cleavage. Overall, we have shown that NB-4 cells expressed M3-mAChR in a differentiation-dependent manner and cholinergic stimulation induced maturation and death of ATRA-induced differentiated NB-4 cells. PMID:27282572

  4. Retinoic acid metabolic change in retina and choroid of the guinea pig with lens-induced myopia

    PubMed Central

    Mao, Jun-Feng; Liu, Shuang-Zhen; Dou, Xiu-Qiong

    2012-01-01

    AIM To investigate the role of retinoic acid (RA) and retinaldehyde dehydrogenase-2 (RALDH2) of retina and choroid in the guinea pig lens-induced myopic eyes. METHODS Totally 45 guinea pigs, at age of three weeks, were randomly assigned into three groups: the normal control, the lens-induced group and the recovering group. Out of focus was induced by the -6.00D concave lens on the left eye, and lasted for 15 days. All animals underwent biometric measurement (corneal radius of curvature, refraction and axial length). Subsequently, RA content in the retina and RPE/choriod complex was detected by reversed-phase high-performance liquid chromatography. RALDH2 protein in the retina and RPE/choriod complex was evaluated by the immunohistochemical staining and Western blotting. RESULTS After wearing -6.00D lens for 15 days, axial length of the lens-induced eye extends and myopia was formed, with RA contents increasing in both the neural retina and RPE/choroid complex. Comparing with the lens-induced group, myopic degree significantly relieved, and its RA contents in both the neural retina and RPE/choroid complex decreased in the recovering group. In the normal control, RALDH2 protein was expressed positively in the retinal nerve fiber layer (RNFL), inner plexiform layer (IPL) and lateral border of outer nuclear layer (ONL). Retinal RALDH2 protein increased in the lens-induced group, and was also positive in the outer plexiform layer (OPL). In the recovering group, retinal RALDH2 protein attenuated the expression in the OPL turns to negative. RALDH2 protein was not expressed in the choroid of any group. CONCLUSION RA of retina and chorid participates in the regulation of the lens-induced myopia in guinea pigs, which may be related with retinal RALDH2 protein. PMID:23275899

  5. All-trans retinoic acid induces cellular senescence by up-regulating levels of p16 and p21 via promoter hypomethylation.

    PubMed

    Lim, Joo Song; Park, Sun-Hye; Jang, Kyung Lib

    2011-09-01

    All-trans retinoic acid (ATRA) induces cellular senescence via up-regulation of p16 and p21; however, the action mechanism of ATRA is unknown. Here, we show that ATRA induces promoter hypomethylation of p16 and p21 via down-regulation of DNA methyltransferases 1, 3a, and 3b to facilitate binding of Ets1/2 to the p16 promoter and p53 to the p21 promoter, resulting in up-regulation of their expression and subsequent induction of cellular senescence in HepG2 cells. These effects were mediated by retinoic acid receptor β₂ whose promoter was also hypomethylated in the presence of ATRA. Therefore, ATRA can be considered as an epi-drug in cancer therapy. PMID:21843507

  6. New discovery of cryptorchidism: Decreased retinoic acid in testicle.

    PubMed

    Peng, Jinpu; Shen, Lianju; Chen, Jinjun; Cao, Xining; Zhou, Yue; Weng, Huali; Long, Chunlan; Zhang, Deying; Tu, Shengfen; Zhang, Yan; He, Dawei; Lin, Tao; Wei, Guanghui

    2016-05-01

    This study focuses on investigation of cryptorchidism induced by flutamide (Flu) and its histopathological damage, and detects retinoic acid concentration in testicle tissue, in order to find a new method for clinical treatment to infertility caused by cryptorchidism. Twenty SD (Sprague Dawley) pregnant rats were randomly divided into Flu cryptorchidism group (n = 10) and normal control group (n = 10). HE stained for observing morphological difference. Transmission electron microscope (TEM) was used for observing the tight junction structure between Sertoli cells. Epididymal caudal sperms were counted and observed in morphology. The expression of stimulated by retinoic acid gene 8 (Stra8) was detected using immunohistochemistry, western blot, and Q-PCR. High performance liquid chromatography (HPLC) analysis was made on retinoic acid content. Sperm count and morphology observation confirmed cryptorchidism group was lower than normal group in sperm quantity and quality. The observation by TEM showed a loose structure of tight junctions between Sertoli cells. Immunohistochemistry, western blot, and Q-PCR showed that cryptorchidism group was significantly lower than normal group in the expression of Stra8. HPLC showed that retinoic acid content was significantly lower in cryptorchid testis than in normal testis. In the cryptorchidism model, retinoic acid content in testicular tissue has a significant reduction; testicles have significant pathological changes; damage exists in the structure of tight junctions between Sertoli cells; Stra8 expression has a significant reduction, perhaps mainly contributing to spermatogenesis disorder. PMID:27275115

  7. PI3K/Akt pathway regulates retinoic acid-induced Hox gene expression in F9 cells.

    PubMed

    Lee, Youra; Lee, Ji-Yeon; Kim, Myoung Hee

    2014-09-01

    Retinoic acid (RA), the most potent natural form of vitamin A, is a key morphogen in vertebrate development and a potent regulator of both adult and embryonic cell differentiation. Specifically, RA regulates clustered Hox gene expression during embryogenesis and is required to establish the anteroposterior body plan. The PI3K/Akt pathway was also reported to play an essential role in the process of RA-induced cell differentiation. Therefore, we tested whether the PI3K/Akt pathway is involved in RA-induced Hox gene expression in a F9 murine embryonic teratocarcinoma cells. To examine the effect of PI3K/Akt signaling on RA-induced initiation of collinear expression of Hox genes, F9 cells were treated with RA in the presence or absence of PI3K inhibitor LY294002, and time-course gene expression profiles for all 39 Hox genes located in four different clusters-Hoxa, Hoxb, Hoxc, and Hoxd-were analyzed. Collinear expression of Hoxa and -b cluster genes was initiated earlier than that of the -c and -d clusters upon RA treatment. When LY294002 was applied along with RA, collinear expression induced by RA was delayed, suggesting that the PI3K/Akt signaling pathway somehow regulates RA-induced collinear expression of Hox genes in F9 cells. The initiation of Hox collinear expression by RA and the delayed expression following LY294002 in F9 cells would provide a good model system to decipher the yet to be answered de novo collinear expression of Hox genes during gastrulation, which make the gastrulating cells to remember their positional address along the AP body axis in the developing embryo. PMID:25212816

  8. Inhibition of hypoxia inducible factors combined with all-trans retinoic acid treatment enhances glial transdifferentiation of neuroblastoma cells

    PubMed Central

    Cimmino, Flora; Pezone, Lucia; Avitabile, Marianna; Acierno, Giovanni; Andolfo, Immacolata; Capasso, Mario; Iolascon, Achille

    2015-01-01

    Neuroblastoma (NBL) is a heterogeneous tumor characterized by a wide range of clinical manifestations. A high tumor cell differentiation grade correlates to a favorable stage and positive outcome. Expression of the hypoxia inducible factors HIF1-α (HIF1A gene) and HIF2-α (EPAS1 gene) and/or hypoxia-regulated pathways has been shown to promote the undifferentiated phenotype of NBL cells. Our hypothesis is that HIF1A and EPAS1 expression represent one of the mechanisms responsible for the lack of responsiveness of NBL to differentiation therapy. Clinically, high levels of HIF1A and EPAS1 expression were associated with inferior survival in two NBL microarray datasets, and patient subgroups with lower expression of HIF1A and EPAS1 showed significant enrichment of pathways related to neuronal differentiation. In NBL cell lines, the combination of all-trans retinoic acid (ATRA) with HIF1A or EPAS1 silencing led to an acquired glial-cell phenotype and enhanced expression of glial-cell differentiation markers. Furthermore, HIF1A or EPAS1 silencing might promote cell senescence independent of ATRA treatment. Taken together, our data suggest that HIF inhibition coupled with ATRA treatment promotes differentiation into a more benign phenotype and cell senescence in vitro. These findings open the way for additional lines of attack in the treatment of NBL minimal residue disease. PMID:26057707

  9. Inhibition of hypoxia inducible factors combined with all-trans retinoic acid treatment enhances glial transdifferentiation of neuroblastoma cells.

    PubMed

    Cimmino, Flora; Pezone, Lucia; Avitabile, Marianna; Acierno, Giovanni; Andolfo, Immacolata; Capasso, Mario; Iolascon, Achille

    2015-01-01

    Neuroblastoma (NBL) is a heterogeneous tumor characterized by a wide range of clinical manifestations. A high tumor cell differentiation grade correlates to a favorable stage and positive outcome. Expression of the hypoxia inducible factors HIF1-α (HIF1A gene) and HIF2-α (EPAS1 gene) and/or hypoxia-regulated pathways has been shown to promote the undifferentiated phenotype of NBL cells. Our hypothesis is that HIF1A and EPAS1 expression represent one of the mechanisms responsible for the lack of responsiveness of NBL to differentiation therapy. Clinically, high levels of HIF1A and EPAS1 expression were associated with inferior survival in two NBL microarray datasets, and patient subgroups with lower expression of HIF1A and EPAS1 showed significant enrichment of pathways related to neuronal differentiation. In NBL cell lines, the combination of all-trans retinoic acid (ATRA) with HIF1A or EPAS1 silencing led to an acquired glial-cell phenotype and enhanced expression of glial-cell differentiation markers. Furthermore, HIF1A or EPAS1 silencing might promote cell senescence independent of ATRA treatment. Taken together, our data suggest that HIF inhibition coupled with ATRA treatment promotes differentiation into a more benign phenotype and cell senescence in vitro. These findings open the way for additional lines of attack in the treatment of NBL minimal residue disease. PMID:26057707

  10. Involvement of apoptotic cell death and cell cycle perturbation in retinoic acid-induced cleft palate in mice

    SciTech Connect

    Okano, Junko . E-mail: okajun@anat1.med.kyoto-u.ac.jp; Suzuki, Shigehiko; Shiota, Kohei

    2007-05-15

    Retinoic acid (RA), a metabolite of vitamin A, plays a key role in a variety of biological processes and is essential for normal embryonic development. On the other hand, exogenous RA could cause cleft palate in offspring when it is given to pregnant animals at either the early or late phases of palatogenesis, but the pathogenetic mechanism of cleft palate caused by excess RA remains not fully elucidated. The aim of the present study was to investigate the effects of excess of RA on early palatogenesis in mouse fetuses and analyze the teratogenic mechanism, especially at the stage prior to palatal shelf elevation. We gave all-trans RA (100 mg/kg) orally to E11.5 ICR pregnant mice and observed the changes occurring in the palatal shelves of their fetuses. It was found that apoptotic cell death increased not only in the epithelium of the palatal shelves but also in the tongue primordium, which might affect tongue withdrawal movement during palatogenesis and impair the horizontal elevation of palatal shelves. In addition, RA was found to prevent the G{sub 1}/S progression of palatal mesenchymal cells through upregulation of p21 {sup Cip1}, leading to Rb hypophospholylation. Thus, RA appears to cause G{sub 1} arrest in palatal mesenchymal cells in a similar manner as in various cancer and embryonic cells. It is likely that apoptotic cell death and cell cycle disruption are involved in cleft palate formation induced by RA.

  11. ALDH1A1 provides a source of meiosis-inducing retinoic acid in mouse fetal ovaries

    PubMed Central

    Bowles, Josephine; Feng, Chun-Wei; Miles, Kim; Ineson, Jessica; Spiller, Cassy; Koopman, Peter

    2016-01-01

    Substantial evidence exists that during fetal ovarian development in mammals, retinoic acid (RA) induces germ cells to express the pre-meiotic marker Stra8 and enter meiosis, and that these effects are prevented in the fetal testis by the RA-degrading P450 enzyme CYP26B1. Nonetheless, the role of RA has been disputed principally because germ cells in embryos lacking two major RA-synthesizing enzymes, ALDH1A2 and ALDH1A3, remain able to enter meiosis. Here we show that a third RA-synthesizing enzyme, ALDH1A1, is expressed in fetal ovaries, providing a likely source of RA in the absence of ALDH1A2 and ALDH1A3. In ovaries lacking ALDH1A1, the onset of germ cell meiosis is delayed. Our data resolve the conundrum posed by conflicting published data sets and reconfirm the model that meiosis is triggered by endogenous RA in the developing ovary. PMID:26892828

  12. Retinoic Acid Prevents Disruption of Blood-Spinal Cord Barrier by Inducing Autophagic Flux After Spinal Cord Injury.

    PubMed

    Zhou, Yulong; Zheng, Binbin; Ye, Libing; Zhang, Hongyu; Zhu, Sipin; Zheng, Xiaomeng; Xia, Qinghai; He, Zili; Wang, Qingqing; Xiao, Jian; Xu, Huazi

    2016-04-01

    Spinal cord injury (SCI) induces the disruption of the blood-spinal cord barrier (BSCB), which leads to infiltration of blood cells, inflammatory responses and neuronal cell death, with subsequent development of spinal cord secondary damage. Recent reports pointed to an important role of retinoic acid (RA), the active metabolite of the vitamin A, in the induction of the blood-brain barrier (BBB) during human and mouse development, however, it is unknown whether RA plays a role in maintaining BSCB integrity under the pathological conditions such as SCI. In this study, we investigated the BSCB protective role of RA both in vivo and in vitro and demonstrated that autophagy are involved in the BSCB protective effect of RA. Our data show that RA attenuated BSCB permeability and also attenuated the loss of tight junction molecules such as P120, β-catenin, Occludin and Claudin5 after injury in vivo as well as in brain microvascular endothelial cells. In addition, RA administration improved functional recovery of the rat model of trauma. We also found that RA could significantly increase the expression of LC3-II and decrease the expression of p62 both in vivo and in vitro. Furthermore, combining RA with the autophagy inhibitor chloroquine (CQ) partially abolished its protective effect on the BSCB and exacerbated the loss of tight junctions. Together, our studies indicate that RA improved functional recovery in part by the prevention of BSCB disruption via the activation of autophagic flux after SCI. PMID:26582233

  13. The BRPF2/BRD1-MOZ complex is involved in retinoic acid-induced differentiation of embryonic stem cells.

    PubMed

    Cho, Hye In; Kim, Min Seong; Jang, Yeun Kyu

    2016-08-01

    The scaffold protein BRPF2 (also called BRD1), a key component of histone acetyltransferase complexes, plays an important role in embryonic development, but its function in the differentiation of embryonic stem cells (ESCs) remains unknown. In the present study, we investigated whether BRPF2 is involved in mouse ESC differentiation. BRPF2 depletion resulted in abnormal formation of embryoid bodies, downregulation of differentiation-associated genes, and persistent maintenance of alkaline phosphatase activity even after retinoic acid-induced differentiation, indicating impaired differentiation of BRPF2-depleted ESCs. We also found reduced global acetylation of histone H3 lysine 14 (H3K14) in BRPF2-depleted ESCs, irrespective of differentiation status. Further, co-immunoprecipitation analysis revealed a physical association between BRPF2 and the histone acetyltransferase MOZ in differentiated ESCs, suggesting the role of BRPF2-MOZ complexes in ESC differentiation. Together, these results suggest that BRPF2-MOZ complexes play an important role in the differentiation of ESCs via H3K14 acetylation. PMID:27256846

  14. Bone morphogenetic protein 4 and retinoic acid trigger bovine VASA homolog expression in differentiating bovine induced pluripotent stem cells.

    PubMed

    Malaver-Ortega, Luis F; Sumer, Huseyin; Jain, Kanika; Verma, Paul J

    2016-02-01

    Primordial germ cells (PGCs) are the earliest identifiable and completely committed progenitors of female and male gametes. They are obvious targets for genome editing because they assure the transmission of desirable or introduced traits to future generations. PGCs are established at the earliest stages of embryo development and are difficult to propagate in vitro--two characteristics that pose a problem for their practical application. One alternative method to enrich for PGCs in vitro is to differentiate them from pluripotent stem cells derived from adult tissues. Here, we establish a reporter system for germ cell identification in bovine pluripotent stem cells based on green fluorescent protein expression driven by the minimal essential promoter of the bovine Vasa homolog (BVH) gene, whose regulatory elements were identified by orthologous modelling of regulatory units. We then evaluated the potential of bovine induced pluripotent stem cell (biPSC) lines carrying the reporter construct to differentiate toward the germ cell lineage. Our results showed that biPSCs undergo differentiation as embryoid bodies, and a fraction of the differentiating cells expressed BVH. The rate of differentiation towards BVH-positive cells increased up to tenfold in the presence of bone morphogenetic protein 4 or retinoic acid. Finally, we determined that the expression of key PGC genes, such as BVH or SOX2, can be modified by pre-differentiation cell culture conditions, although this increase is not necessarily mirrored by an increase in the rate of differentiation. PMID:26660942

  15. Topical retinoic acid does not alter the vasoconstrictive properties of topical corticosteroids in humans.

    PubMed

    Schmied, C; Saurat, J H

    1991-01-01

    Dermo-epidermal atrophy is one of the main side effects of long-term treatment with topical corticosteroids. Retinoic acid may prevent and even reverse these effects in animals. Extension of this concept to therapy in humans implies that several studies have been performed; among others, it has to be established that treatment with topical retinoic acid does not interfere with the anti-inflammatory action of topical corticosteroids. The present study on the cutaneous vasoconstriction test comprised two different double-blind approaches: (i) vasoconstriction tests with betamethasone dipropionate (Diprolene) and clobetasone butyrate (Emovate) were carried out on skin that had previously been treated for 10 days with retinoic acid 0.01, 0.025 or 0.05% (or excipient); (ii) vasoconstriction tests with a combination of triamcinolone acetonide 0.1% and retinoic acid 0.025% were compared with triamcinolone acetonide 0.1% alone. Pretreatment for 10 days with retinoic acid did not alter the vasoconstriction induced by corticosteroids: no decrease or increase in the vasoconstriction score was observed, whether the skin had been previously treated with retinoic acid or with excipient. The vasoconstriction scores obtained with a combination of retinoic acid and triamcinolone acetonide were identical with those obtained with the steroid alone. This study indicates that retinoic acid does not inhibit the vasoconstriction induced by topical corticosteroids and suggests that the anti-inflammatory effect of the latter should be maintained in association with retinoic acid. PMID:2050230

  16. Sonic hedgehog and retinoic Acid induce bone marrow-derived stem cells to differentiate into glutamatergic neural cells.

    PubMed

    Yu, Zhenhai; Wu, Shixing; Liu, Zhen; Lin, Haiyan; Chen, Lei; Yuan, Xinli; Zhang, Zhiying; Liu, Fang; Zhang, Chuansen

    2015-01-01

    Studies have showed that transplanted stem cells in the inner ear won't regenerate to replace the damaged sensory hair cells. They can spontaneously differentiate into mesenchymal cells and fibrocytes in the damaged inner ear. Only mature sensory cells of MSCs-derived possess the great potency for cell transplantation in the treatment of sensorineural hearing loss. So, we try to establish an efficient generation of the glutamatergic sensory neural phenotype for the cell transplantation of the hearing loss. We isolated MSCs from femoral and tibial bones according to their adherence to culture dishes. After purification, proliferation, and passaged, cells became homogeneous in appearance, showing more uniformity and grew in a monolayer with a typical spindle-shape morphology. The cell surface markers were assessed using FACS to characterize the isolated cells. For neural induction to harvest the glutamatergic sensory neurons, passage 3 MSCs were incubated with preinduced medium for 24 hr, and neural-induced medium for an additional 14 days. The cells exhibit a typical neural shape. RT-PCR analysis indicated that the mRNA levels of the neural cell marker nestin, Tau, MAP-2, β-tubulin III, GluR-3, and GluR-4 were higher compared with primary MSCs. Immunohistochemistry and western-blotting proofed that nestin, MAP-2, β-tubulin III, and GluR-4 proteins indeed exhibit their expression difference in the induced cells compared to the MSCs. We show an efficient protocol by the combined applications of Sonic Hedgehog (Shh) and Retinoic Acid (RA) to induce MSCs to differentiate into the glutamatergic sensory neuron which were identified from the morphological, biochemical, and molecular characteristics. PMID:24547891

  17. Retinoic acid inhibits the proliferative response induced by CD40 activation and interleukin-4 in mantle cell lymphoma.

    PubMed

    Guidoboni, Massimo; Zancai, Paola; Cariati, Roberta; Rizzo, Silvana; Dal Col, Jessica; Pavan, Alessandro; Gloghini, Annunziata; Spina, Michele; Cuneo, Antonio; Pomponi, Fabrizio; Bononi, Antonio; Doglioni, Claudio; Maestro, Roberta; Carbone, Antonino; Boiocchi, Mauro; Dolcetti, Riccardo

    2005-01-15

    Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin's lymphoma with poor response to therapy and unfavorable prognosis. Here, we show that retinoic acid (RA) isomers significantly inhibit the proliferation of both primary MCL cultures (n = 7) and established cell lines (Granta 519 and SP-53) as shown by [(3)H]thymidine uptake and carboxyfluorescein diacetate succinimidyl ester labeling coupled with cyclin D1 staining. RA induces cell accumulation in G(0)-G(1) together with a marked up-regulation of p27(Kip1) by inhibiting ubiquitination and proteasome-dependent degradation of the protein. The p21(Cip1) inhibitor was also up-regulated by RA in Granta 519 cells, whereas the expression of cyclin D1 is unaffected. Most of RA-induced p27(Kip1) was bound to cyclin D1/cyclin-dependent kinase 4 complexes, probably contributing to the decreased cyclin-dependent kinase 4 kinase activity and pRb hypophosphorylation observed in RA-treated cells. Experiments with receptor-selective ligands indicate that RA receptor alpha cooperates with retinoid X receptors in mediating RA-dependent MCL cell growth inhibition. Notably, RA isomers, and particularly 9-cis-RA, also inhibited the growth-promoting effect induced in primary MCL cells by CD40 activation alone or in combination with interleukin-4. Immunohistochemical analysis showed that significant numbers of CD40L-expressing lymphoid cells are present in lymph node biopsies of MCL patients. These results therefore further strengthen the possibility that triggering of CD40 by infiltrating CD40L+ cells may continuously promote the growth of MCL cells in vivo. On these grounds, our findings that RA inhibits basal MCL proliferation as well as MCL growth-promoting effects exerted by microenvironmental factors make these compounds highly attractive in terms of potential clinical efficacy in this setting. PMID:15695403

  18. Retinoic acid-induced AP-1 transcriptional activity regulates B16 mouse melanoma growth inhibition and differentiation.

    PubMed

    Huang, Ying; Boskovic, Goran; Niles, Richard M

    2003-02-01

    Retinoic acid (RA) inhibits growth and induces differentiation of B16 mouse melanoma cells. These effects are accompanied by a large increase in PKCalpha mRNA and protein levels and surprisingly an increase in activating protein-1 (AP-1) transcriptional activity. To further investigate the RA-induced AP-1 activity we established clones of B16 cells stably expressing an AP-1-luciferase reporter gene. Treatment of these clones with phorbol dibutyrate increased AP-1 activity which peaked at 2-4 h and returned to baseline level by 24 h. In contrast, RA treatment resulted in a slow increase in AP-1 activity that reached a maximum level at 48 h and was maintained for the duration of the treatment. We tested the importance of the RA-induced AP-1 activity by establishing clones which stably express a dominant negative fos gene (A-fos) and have greatly diminished AP-1 activity. Growth rates of untreated A-fos expressing cells were similar to wt B16 and clones not expressing A-fos. However, clones expressing the dominant-negative fos had a markedly decreased sensitivity to RA-induced inhibition of anchorage-dependent and -independent growth. Treatment of wt B16 cells for 48 h with RA increased melanin production by two to fourfold, but this effect was completely lost in the A-fos clones. The ability of RA to induce RARbeta and PKCalpha expression was retained in A-fos clones, suggesting that A-fos was not interfering with RAR transcription activation functions. We tested whether the RA-induced AP-1 activity might be mediated by the ERK1/2 MAPK pathway. Inhibition of ERK1/2 phosphorylation stimulated AP-1 activity, which was not additive to that induced by RA. This finding raises the possibility that this MAPK pathway may be a target of retinoid action. Our observations suggest that AP-1 transcriptional activity induced by RA likely plays an important role in the biological changes mediated by this retinoid in B16 melanoma cells. PMID:12494454

  19. Evidence for genetic regulation of mRNA expression of the dosage-sensitive gene retinoic acid induced-1 (RAI1) in human brain

    PubMed Central

    Chen, Li; Tao, Yu; Song, Fan; Yuan, Xi; Wang, Jian; Saffen, David

    2016-01-01

    RAI1 (retinoic acid induced-1) is a dosage-sensitive gene that causes Smith-Magenis syndrome (SMS) when mutated or deleted and Potocki-Lupski Syndrome (PTLS) when duplicated, with psychiatric features commonly observed in both syndromes. How common genetic variants regulate this gene, however, is unknown. In this study, we found that RAI1 mRNA expression in Chinese prefrontal and temporal cortex correlate with genotypes of common single nucleotide polymorphisms (SNPs) located in the RAI1 5′-upstream region. Using genotype imputation, “R2-Δ2” analysis, and data from the RegulomeDB database, we identified SNPs rs4925102 and rs9907986 as possible regulatory variants, accounting for approximately 30–40% of the variance in RAI1 mRNA expression in both brain regions. Specifically, rs4925102 and rs9907986 are predicted to disrupt the binding of retinoic acid RXR-RAR receptors and the transcription factor DEAF1 (Deformed epidermal autoregulatory factor-1), respectively. Consistent with these predictions, we observed binding of RXRα and RARα to the predicted RAI1 target in chromatin immunoprecipitation assays. Retinoic acid is crucial for early development of the central neural system, and DEAF1 is associated with intellectual disability. The observation that a significant portion of RAI1 mRNA expression is genetically controlled raises the possibility that common RAI1 5′-region regulatory variants contribute more generally to psychiatric disorders. PMID:26743651

  20. Evidence for genetic regulation of mRNA expression of the dosage-sensitive gene retinoic acid induced-1 (RAI1) in human brain.

    PubMed

    Chen, Li; Tao, Yu; Song, Fan; Yuan, Xi; Wang, Jian; Saffen, David

    2016-01-01

    RAI1 (retinoic acid induced-1) is a dosage-sensitive gene that causes Smith-Magenis syndrome (SMS) when mutated or deleted and Potocki-Lupski Syndrome (PTLS) when duplicated, with psychiatric features commonly observed in both syndromes. How common genetic variants regulate this gene, however, is unknown. In this study, we found that RAI1 mRNA expression in Chinese prefrontal and temporal cortex correlate with genotypes of common single nucleotide polymorphisms (SNPs) located in the RAI1 5'-upstream region. Using genotype imputation, "R(2)-Δ(2)" analysis, and data from the RegulomeDB database, we identified SNPs rs4925102 and rs9907986 as possible regulatory variants, accounting for approximately 30-40% of the variance in RAI1 mRNA expression in both brain regions. Specifically, rs4925102 and rs9907986 are predicted to disrupt the binding of retinoic acid RXR-RAR receptors and the transcription factor DEAF1 (Deformed epidermal autoregulatory factor-1), respectively. Consistent with these predictions, we observed binding of RXRα and RARα to the predicted RAI1 target in chromatin immunoprecipitation assays. Retinoic acid is crucial for early development of the central neural system, and DEAF1 is associated with intellectual disability. The observation that a significant portion of RAI1 mRNA expression is genetically controlled raises the possibility that common RAI1 5'-region regulatory variants contribute more generally to psychiatric disorders. PMID:26743651

  1. Thyroid hormone receptor can modulate retinoic acid-mediated axis formation in frog embryogenesis.

    PubMed Central

    Banker, D E; Eisenman, R N

    1993-01-01

    Thyroid hormone receptor acts as a hormone-dependent transcriptional transactivator and as a transcriptional repressor in the absence of thyroid hormone. Specifically, thyroid hormone receptor can repress retinoic acid-induced gene expression through interactions with retinoic acid receptor. (Retinoic acid is a potent teratogen in the frog Xenopus laevis, acting at early embryonic stages to interfere with the formation of anterior structures. Endogenous retinoic acid is thought to act in normal anterior-posterior axis formation.) We have previously shown that thyroid hormone receptor RNA (alpha isotype) is expressed and polysome-associated during Xenopus embryogenesis preceding thyroid gland maturation and endogenous thyroid hormone production (D. E. Banker, J. Bigler, and R. N. Eisenman, Mol. Cell. Biol. 11:5079-5089, 1991). To determine whether thyroid hormone receptor might influence the effects of retinoic acid in early frog development, we have examined the results of ectopic thyroid hormone receptor expression on retinoic acid teratogenesis. We demonstrate that microinjections of full-length thyroid hormone receptor RNA protect injected embryos from retinoic acid teratogenesis. DNA binding is apparently essential to this protective function, as truncated thyroid hormone receptors, lacking DNA-binding domains but including hormone-binding and dimerization domains, do not protect from retinoic acid. We have shown that microinjections of these dominant-interfering thyroid hormone receptors, as well as anti-thyroid hormone receptor antibodies, increase retinoic acid teratogenesis in injected embryos, presumably by inactivating endogenous thyroid hormone receptor. This finding suggests that endogenous thyroid hormone receptors may act to limit retinoic acid sensitivity. On the other hand, after thyroid hormone treatment, ectopic thyroid hormone receptor mediates teratogenesis that is indistinguishable from the dorsoanterior deficiencies produced in retinoic acid

  2. Retinoic Acid Induces Embryonic Stem Cell Differentiation by Altering Both Encoding RNA and microRNA Expression

    PubMed Central

    Yu, Mengying; Wu, Haibo; Ai, Zhiying; Wu, Yongyan; Liu, Hongliang; Du, Juan; Guo, Zekun; Zhang, Yong

    2015-01-01

    Retinoic acid (RA) is a vitamin A metabolite that is essential for early embryonic development and promotes stem cell neural lineage specification; however, little is known regarding the impact of RA on mRNA transcription and microRNA levels on embryonic stem cell differentiation. Here, we present mRNA microarray and microRNA high-output sequencing to clarify how RA regulates gene expression. Using mRNA microarray analysis, we showed that RA repressed pluripotency-associated genes while activating ectoderm markers in mouse embryonic stem cells (mESCs). Moreover, RA modulated the DNA methylation of mESCs by altering the expression of epigenetic-associated genes such as Dnmt3b and Dnmt3l. Furthermore, H3K4me2, a pluripotent histone modification, was repressed by RA stimulation. From microRNA sequence data, we identified two downregulated microRNAs, namely, miR-200b and miR-200c, which regulated the pluripotency of stem cells. We found that miR-200b or miR-200c deficiency suppressed the expression of pluripotent genes, including Oct4 and Nanog, and activated the expression of the ectodermal marker gene Nestin. These results demonstrate that retinoid induces mESCs to differentiate by regulating miR-200b/200c. Our findings provide the landscapes of mRNA and microRNA gene networks and indicate the crucial role of miR-200b/200c in the RA-induced differentiation of mESCs. PMID:26162091

  3. Integrating Retinoic Acid Signaling with Brain Function

    ERIC Educational Resources Information Center

    Luo, Tuanlian; Wagner, Elisabeth; Drager, Ursula C.

    2009-01-01

    The vitamin A derivative retinoic acid (RA) regulates the transcription of about a 6th of the human genome. Compelling evidence indicates a role of RA in cognitive activities, but its integration with the molecular mechanisms of higher brain functions is not known. Here we describe the properties of RA signaling in the mouse, which point to…

  4. Functional and cellular characterization of human Retinoic Acid Induced 1 (RAI1) mutations associated with Smith-Magenis Syndrome

    PubMed Central

    2010-01-01

    Background Smith-Magenis Syndrome is a contiguous gene syndrome in which the dosage sensitive gene has been identified: the Retinoic Acid Induced 1 (RAI1). Little is known about the function of human RAI1. Results We generated the full-length cDNA of the wild type protein and five mutated forms: RAI1-HA 2687delC, RAI1-HA 3103delC, RAI1 R960X, RAI1-HA Q1562R, and RAI1-HA S1808N. Four of them have been previously associated with SMS clinical phenotype. Molecular weight, subcellular localization and transcription factor activity of the wild type and mutant forms were studied by western blot, immunofluorescence and luciferase assays respectively. The wild type protein and the two missense mutations presented a higher molecular weight than expected, localized to the nucleus and activated transcription of a reporter gene. The frameshift mutations generated a truncated polypeptide with transcription factor activity but abnormal subcellular localization, and the same was true for the 1-960aa N-terminal half of RAI1. Two different C-terminal halves of the RAI1 protein (1038aa-end and 1229aa-end) were able to localize into the nucleus but had no transactivation activity. Conclusion Our results indicate that transcription factor activity and subcellular localization signals reside in two separate domains of the protein and both are essential for the correct functionality of RAI1. The pathogenic outcome of some of the mutated forms can be explained by the dissociation of these two domains. PMID:20738874

  5. Retinoic Acid Induced 1, RAI1: A Dosage Sensitive Gene Related to Neurobehavioral Alterations Including Autistic Behavior

    PubMed Central

    Carmona-Mora, Paulina; Walz, Katherina

    2010-01-01

    Genomic structural changes, such as gene Copy Number Variations (CNVs) are extremely abundant in the human genome. An enormous effort is currently ongoing to recognize and catalogue human CNVs and their associations with abnormal phenotypic outcomes. Recently, several reports related neuropsychiatric diseases (i.e. autism spectrum disorders, schizophrenia, mental retardation, behavioral problems, epilepsy) with specific CNV. Moreover, for some conditions, both the deletion and duplication of the same genomic segment are related to the phenotype. Syndromes associated with CNVs (microdeletion and microduplication) have long been known to display specific neurobehavioral traits. It is important to note that not every gene is susceptible to gene dosage changes and there are only a few dosage sensitive genes. Smith-Magenis (SMS) and Potocki-Lupski (PTLS) syndromes are associated with a reciprocal microdeletion and microduplication within chromosome 17p11.2. in humans. The dosage sensitive gene responsible for most phenotypes in SMS has been identified: the Retinoic Acid Induced 1 (RAI1). Studies on mouse models and humans suggest that RAI1 is likely the dosage sensitive gene responsible for clinical features in PTLS. In addition, the human RAI1 gene has been implicated in several neurobehavioral traits as spinocerebellar ataxia (SCA2), schizophrenia and non syndromic autism. In this review we discuss the evidence of RAI1 as a dosage sensitive gene, its relationship with different neurobehavioral traits, gene structure and mutations, and what is known about its molecular and cellular function, as a first step in the elucidation of the mechanisms that relate dosage sensitive genes with abnormal neurobehavioral outcomes. PMID:21629438

  6. Activation of AMP-activated protein kinase by retinoic acid sensitizes hepatocellular carcinoma cells to apoptosis induced by sorafenib

    PubMed Central

    Ishijima, Naoki; Kanki, Keita; Shimizu, Hiroki; Shiota, Goshi

    2015-01-01

    To improve the outcome of cancer chemotherapy, strategies to enhance the efficacy of anticancer drugs are required. Sorafenib is the only drug to prolong overall survival of the patients with hepatocellular carcinoma (HCC), however, the outcome is still not satisfactory. Retinoids, vitamin A derivatives, have been known to exhibit inhibitory effects on various cancers including HCC. In this study, we investigated the effects of combined treatment using sorafenib and retinoids including all-trans retinoic acid (ATRA), NIK-333, and Am80 on HCC cells. Cell viability assays in six HCC cell lines, HepG2, PLC/PRF/5, HuH6, HLE, HLF, and Hep3B, revealed that 5 and 10 μM ATRA, concentrations that do not exert cytotoxic effects, enhanced the cytotoxicity of sorafenib, being much more effective than NIK-333 and Am80. We found that ATRA induced AMP-activated protein kinase activation, which was followed by reduced intracellular ATP level. Gene expression analysis revealed that ATRA decreased the expression of glycolytic genes such as GLUT-1 and LDHA. In the combination treatment using ATRA and sorafenib, increased apoptosis, followed by the activation of p38 MAPK and JNK, the upregulation and translocation of Bax to mitochondria, and the activation of caspase-3, was observed. Suppression of AMP-activated protein kinase by siRNA restored the viability of the cells treated with ATRA and sorafenib. Our results thus indicate that ATRA is useful for enhancing the cytotoxicity of sorafenib against HCC cells by regulating the energy metabolism of HCC cells. PMID:25683251

  7. Activation of AMP-activated protein kinase by retinoic acid sensitizes hepatocellular carcinoma cells to apoptosis induced by sorafenib.

    PubMed

    Ishijima, Naoki; Kanki, Keita; Shimizu, Hiroki; Shiota, Goshi

    2015-05-01

    To improve the outcome of cancer chemotherapy, strategies to enhance the efficacy of anticancer drugs are required. Sorafenib is the only drug to prolong overall survival of the patients with hepatocellular carcinoma (HCC), however, the outcome is still not satisfactory. Retinoids, vitamin A derivatives, have been known to exhibit inhibitory effects on various cancers including HCC. In this study, we investigated the effects of combined treatment using sorafenib and retinoids including all-trans retinoic acid (ATRA), NIK-333, and Am80 on HCC cells. Cell viability assays in six HCC cell lines, HepG2, PLC/PRF/5, HuH6, HLE, HLF, and Hep3B, revealed that 5 and 10 μM ATRA, concentrations that do not exert cytotoxic effects, enhanced the cytotoxicity of sorafenib, being much more effective than NIK-333 and Am80. We found that ATRA induced AMP-activated protein kinase activation, which was followed by reduced intracellular ATP level. Gene expression analysis revealed that ATRA decreased the expression of glycolytic genes such as GLUT-1 and LDHA. In the combination treatment using ATRA and sorafenib, increased apoptosis, followed by the activation of p38 MAPK and JNK, the upregulation and translocation of Bax to mitochondria, and the activation of caspase-3, was observed. Suppression of AMP-activated protein kinase by siRNA restored the viability of the cells treated with ATRA and sorafenib. Our results thus indicate that ATRA is useful for enhancing the cytotoxicity of sorafenib against HCC cells by regulating the energy metabolism of HCC cells. PMID:25683251

  8. Retinoic acid affects the expression of nuclear retinoic acid receptors in tissues of retinol-deficient rats.

    PubMed Central

    Haq, R; Pfahl, M; Chytil, F

    1991-01-01

    The multitude of biological effects of the vitamin A metabolite, retinoic acid, are mediated by nuclear retinoic acid receptors (RARs), which are members of the steroid/thyroid hormone receptor superfamily. RAR-alpha, -beta, and -gamma are encoded by three genes from which multiple isoforms can be generated. Recent studies suggest that the expression of at least some RAR isoforms can be regulated by retinoic acid in certain cell lines. Here we examined regulation of RAR expression in the adult animal. RARs were analyzed by Northern blots from lung, liver, and testes of retinol-deficient rats. Retinol deficiency caused a 65-70% decrease in the mRNA levels of lung and liver RAR-beta, whereas no change was observed in RAR-alpha and -gamma mRNA levels in these organs. In the testes of retinol-deficient animals, two transcripts, RAR-alpha 1 (3.7 kb) and RAR-alpha 2 (2.8 kb), were detected as compared with one RAR-alpha 1 (3.7 kb) transcript in retinol-sufficient testes. When retinol-deficient rats were orally administered 1 dose of retinoic acid (100 micrograms per rat), lung RAR-beta mRNA levels started to increase after 1 hr and reached a 16-fold higher level after 4 hr; after 4 hr these retinoic acid-fed rats also showed a 7-fold increase in liver RAR-beta mRNA levels as compared with levels in the retinol-deficient rats. In contrast, liver, lung, and testes RAR-alpha transcripts remained either unchanged or showed only a slight increase in response to retinoic acid. RAR-gamma was constitutively expressed in lung, and its mRNA levels were induced 2-fold by retinoic acid. These results show tissue diversity in the rapid induction of RAR-beta and RAR-gamma by retinoic acid in the adult animal and suggest distinct roles for the various receptor isoforms in the control of the retinoid response. Images PMID:1654565

  9. Enhancement of caffeic acid phenethyl ester on all-trans retinoic acid-induced differentiation in human leukemia HL-60 cells

    SciTech Connect

    Kuo, H.-C.; Kuo, W.-H.; Lee, Y.-J.; Wang, C.-J.; Tseng, T.-H. . E-mail: tht@csmu.edu.tw

    2006-10-01

    All-trans retinoic acid (ATRA) induces complete remission in a high proportion of patients with acute promyelocytic leukemia (APL); however, the response is sometimes very slow. Furthermore, relapse and resistance to treatment often occur despite continued treatment with ATRA. Thereafter, combination treatment strategies have been suggested to circumvent these problems. The present study demonstrates that caffeic acid phenethyl ester (CAPE), a major component of honeybee propolis, enhanced ATRA-induced granulocytic differentiation in HL-60, a human promyelocytic cell line. The differentiation was assessed by Wright-Giemsa stain, nitroblue tetrazolium reduction, and membrane differentiation marker CD11b. In addition, CAPE enhanced ATRA-induced cell cycle arrest at the G1 phase by decreasing the association of cdk2-cyclin E complex. Finally, it was demonstrated that CAPE promoted the ATRA-mediated nuclear transcription activation of RAR{alpha} assessed by EMSA assay and enhanced the expression of target genes including RAR{alpha}, C/EBP{epsilon}, and p21 protein resulting in the differentiation development of leukemia. It is suggested that CAPE possesses the potential to enhance the efficiency of ATRA in the differentiation therapy of APL.

  10. All-trans retinoic acid protects against arsenic-induced uterine toxicity in female Sprague-Dawley rats

    SciTech Connect

    Chatterjee, A.; Chatterji, U.

    2011-12-15

    Background and purpose: Arsenic exposure frequently leads to reproductive failures by disrupting the rat uterine histology, hormonal integrity and estrogen signaling components of the rat uterus, possibly by generating reactive oxygen species. All-trans retinoic acid (ATRA) was assessed as a prospective therapeutic agent for reversing reproductive disorders. Experimental approach: Rats exposed to arsenic for 28 days were allowed to either recover naturally or were treated simultaneously with ATRA for 28 days or treatment continued up to 56 days. Hematoxylin-eosin double staining was used to evaluate changes in the uterine histology. Serum gonadotropins and estradiol were assayed by ELISA. Expression of the estrogen receptor (ER{alpha}), an estrogen responsive gene vascular endothelial growth factor (VEGF), and cell cycle regulatory proteins, cyclin D1 and CDK4, was assessed by RT-PCR, immunohistochemistry and western blot analysis. Key results: ATRA ameliorated sodium arsenite-induced decrease in circulating estradiol and gonadotropin levels in a dose- and time-dependent manner, along with recovery of luminal epithelial cells and endometrial glands. Concomitant up regulation of ER{alpha}, VEGF, cyclin D1, CDK4 and Ki-67 was also observed to be more prominent for ATRA-treated rats as compared to the rats that were allowed to recover naturally for 56 days. Conclusions and implications: Collectively, the results reveal that ATRA reverses arsenic-induced disruption of the circulating levels of gonadotropins and estradiol, and degeneration of luminal epithelial cells and endometrial glands of the rat uterus, indicating resumption of their functional status. Since structural and functional maintenance of the pubertal uterus is under the influence of estradiol, ATRA consequently up regulated the estrogen receptor and resumed cellular proliferation, possibly by an antioxidant therapeutic approach against arsenic toxicity. Highlights: Black-Right-Pointing-Pointer Arsenic

  11. Increased expression of retinoic acid-induced gene 1 in the dorsolateral prefrontal cortex in schizophrenia, bipolar disorder, and major depression

    PubMed Central

    Haybaeck, Johannes; Postruznik, Magdalena; Miller, Christine L; Dulay, Jeannette R; Llenos, Ida C; Weis, Serge

    2015-01-01

    Background Retinoids regulate gene expression in different cells and tissues at the transcriptional level. Retinoic acid transcriptionally regulates downstream regulatory molecules, including enzymes, transcription factors, cytokines, and cytokine receptors. Animal models indicate an involvement of retinoid signaling pathways in the regulation of synaptic plasticity and learning, especially in the hippocampus. Retinoic acid-inducible or induced gene 1 (RAI-1) is induced during neuronal differentiation, and was associated with the severity of the phenotype and response to medication in schizophrenic patients. Methods In the present study, we used immunohistochemistry to investigate the expression of RAI-1 in 60 brains from the Stanley Neuropathology Consortium (15 cases each from controls and from patients with schizophrenia, bipolar disorder, and major depression). Rating scores for density and intensity were determined in the dorsolateral prefrontal cortex. Results All four groups showed high interindividual variation. RAI-1-positive cells were identified as neurons and astrocytes. Significantly increased intensities in cortical neurons were noted in all three major psychiatric groups compared with controls. The density of RAI-1-positive neurons was increased (P=0.06) in schizophrenia and bipolar disorder. In bipolar disorder, RAI-1-positive astrocytes in gray matter showed a significantly increased intensity and compound value. Thus, a significant increase in the parameters measured was found in schizophrenia, bipolar disorder, and major depression. Conclusion Our study shows a significant increase in expression of RAI-1 in the brains from patients with schizophrenia, bipolar disorder, or major depression. The increased expression might reflect altered signaling pathways, like that for retinoic acid. The underlying mechanisms leading to the increased expression and its functional consequences are so far unknown, and remain to be investigated in future studies

  12. Induced Differentiation of Human Myeloid Leukemia Cells into M2 Macrophages by Combined Treatment with Retinoic Acid and 1α,25-Dihydroxyvitamin D3

    PubMed Central

    Takahashi, Hiromichi; Hatta, Yoshihiro; Iriyama, Noriyoshi; Hasegawa, Yuichiro; Uchida, Hikaru; Nakagawa, Masaru; Makishima, Makoto; Takeuchi, Jin; Takei, Masami

    2014-01-01

    Retinoids and 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) induce differentiation of myeloid leukemia cells into granulocyte and macrophage lineages, respectively. All-trans retinoic acid (ATRA), which is effective in the treatment of acute promyelocytic leukemia, can induce differentiation of other types of myeloid leukemia cells, and combined treatment with retinoid and 1,25(OH)2D3 effectively enhances the differentiation of leukemia cells into macrophage-like cells. Recent work has classified macrophages into M1 and M2 types. In this study, we investigated the effect of combined treatment with retinoid and 1,25(OH)2D3 on differentiation of myeloid leukemia THP-1 and HL60 cells. 9-cis Retinoic acid (9cRA) plus 1,25(OH)2D3 inhibited proliferation of THP-1 and HL60 cells and increased myeloid differentiation markers including nitroblue tetrazolium reducing activity and expression of CD14 and CD11b. ATRA and the synthetic retinoic acid receptor agonist Am80 exhibited similar effects in combination with 1,25(OH)2D3 but less effectively than 9cRA, while the retinoid X receptor agonist HX630 was not effective. 9cRA plus 1,25(OH)2D3 effectively increased expression of M2 macrophage marker genes, such as CD163, ARG1 and IL10, increased surface CD163 expression, and induced interleukin-10 secretion in myeloid leukemia cells, while 9cRA alone had weaker effects on these phenotypes and 1,25(OH)2D3 was not effective. Taken together, our results demonstrate selective induction of M2 macrophage markers in human myeloid leukemia cells by combined treatment with 9cRA and 1,25(OH)2D3. PMID:25409436

  13. Retinoic acid induces macrophage cholesterol efflux and inhibits atherosclerotic plaque formation in apoE-deficient mice.

    PubMed

    Zhou, Wenjing; Lin, Jiacheng; Chen, Hongen; Wang, Jingjing; Liu, Yan; Xia, Min

    2015-08-28

    It has been suggested that retinoic acid (RA) has a potential role in the prevention of atherosclerotic CVD. In the present study, we used J774A.1 cell lines and primary peritoneal macrophages to investigate the protective effects of RA on foam cell formation and atherogenesis in apoE-deficient (apoE- / -) mice. A total of twenty male apoE- / - mice (n 10 animals per group), aged 8 weeks, were fed on a high-fat diet (HFD) and treated with vehicle or 9-cis-RA for 8 weeks. The atherosclerotic plaque area in the aortic sinus of mice in the 9-cis-RA group was 40·7 % less than that of mice in the control group (P< 0·01). Mouse peritoneal macrophages from the 9-cis-RA group had higher protein expression levels of ATP-binding cassette transporter A1 (ABCA1) and G1 (ABCG1) than those from the control group. Serum total and LDL-cholesterol concentrations were lower in the 9-cis-RA group than in the control group (P< 0·05). In vitro studies showed that incubation of cholesterol-loaded J774A.1 macrophages with 9-cis-RA (0·1, 1 and 10 μmol/l) induced cholesterol efflux in a dose-dependent manner. The 9-cis-RA treatment markedly attenuated lipid accumulation in macrophages exposed to oxidised LDL. Moreover, treatment with 9-cis-RA significantly increased the protein expression levels of ABCA1 and ABCG1 in J774A.1 macrophages in a dose-dependent manner. Furthermore, 9-cis-RA dose-dependently enhanced the protein expression level of liver X receptor-α (LXRα), the upstream regulator of ABCA1 and ABCG1. Taken together, the present results show that 9-cis-RA suppresses foam cell formation and prevents HFD-induced atherogenesis via the LXRα-dependent up-regulation of ABCA1 and ABCG1. PMID:26201974

  14. Co-adjuvant effects of retinoic acid and IL-15 induce inflammatory immunity to dietary antigens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Under physiological conditions the gut-associated lymphoid tissues not only prevent the induction of a local inflammatory immune response, but also induce systemic tolerance to fed antigens. A notable exception is coeliac disease, where genetically susceptible individuals expressing human leukocyte...

  15. The E3 ubiquitin protein ligase MDM2 dictates all-trans retinoic acid-induced osteoblastic differentiation of osteosarcoma cells by modulating the degradation of RARα.

    PubMed

    Ying, M; Zhang, L; Zhou, Q; Shao, X; Cao, J; Zhang, N; Li, W; Zhu, H; Yang, B; He, Q

    2016-08-18

    Retinoic acid receptor alpha (RARα) has a critical role in the differentiation process of osteosarcoma cells induced by all-trans retinoic acid (ATRA). However, degradation of RARα through ubiquitin proteasome pathway weakens the differentiation efficiency of osteosarcoma cells. In this study, we discover that murine double minute-2 (MDM2) acts as an E3 ubiquitin ligase to target RARα for degradation. We observe that MDM2 is required for RARα polyubiquitination and proteasomal degradation because downregulation of MDM2 by short hairpin RNA results in the accumulation of RARα, and MDM2 overexpression promotes the degradation of RARα. We also demonstrate that the N-terminal domain of MDM2 (amino acids 1-109) is the major RARα-binding site. Importantly, endogenous MDM2 levels are not only upregulated in human primary osteosarcoma blasts but are also inversely correlated with the level of osteopontin, which is a marker of bone differentiation. Moreover, MDM2 impairs the ATRA-induced osteoblastic differentiation of osteosarcoma cells, whereas an inhibitor of the MDM2 ubiquitin ligase synergizes with ATRA to enhance the differentiation of osteosarcoma cells and primary osteosarcoma blasts. Therefore, our study indicates that MDM2 serves as an E3 ubiquitin ligase to regulate the degradation of RARα and suggests that MDM2 is a novel therapeutic target for ATRA-based differentiation therapeutic approaches in osteosarcoma. PMID:26776160

  16. Retinoic acid-induced IgG production in TLR-activated human primary B cells involves ULK1-mediated autophagy

    PubMed Central

    Eriksen, Agnete Bratsberg; Torgersen, Maria Lyngaas; Holm, Kristine Lillebø; Abrahamsen, Greger; Spurkland, Anne; Moskaug, Jan Øivind; Simonsen, Anne; Blomhoff, Heidi Kiil

    2015-01-01

    In the present study we have established a vital role of autophagy in retinoic acid (RA)-induced differentiation of toll-like receptor (TLR)-stimulated human B cells into Ig-secreting cells. Thus, RA enhanced autophagy in TLR9- and CD180-stimulated peripheral blood B cells, as revealed by increased levels of the autophagosomal marker LC3B-II, enhanced colocalization between LC3B and the lysosomal marker Lyso-ID, by a larger percentage of cells with more than 5 characteristic LC3B puncta, and by the concomitant reduction in the level of SQSTM1/p62. Furthermore, RA induced expression of the autophagy-inducing protein ULK1 at the transcriptional level, in a process that required the retinoic acid receptor RAR. By inhibiting autophagy with specific inhibitors or by knocking down ULK1 by siRNA, the RA-stimulated IgG production in TLR9- and CD180-mediated cells was markedly reduced. We propose that the identified prominent role of autophagy in RA-mediated IgG-production in normal human B cells provides a novel mechanism whereby vitamin A exerts its important functions in the immune system. PMID:25749095

  17. Chromatin Changes in Dicer-Deficient Mouse Embryonic Stem Cells in Response to Retinoic Acid Induced Differentiation

    PubMed Central

    Cooney, Austin J.; Gunaratne, Preethi H.

    2013-01-01

    Loss of Dicer, an enzyme critical for microRNA biogenesis, results in lethality due to a block in mouse embryonic stem cell (mES) differentiation. Using ChIP-Seq we found increased H3K9me2 at over 900 CpG islands in the Dicer-/-ES epigenome. Gene ontology analysis revealed that promoters of chromatin regulators to be among the most impacted by increased CpG island H3K9me2 in ES (Dicer-/-). We therefore, extended the study to include H3K4me3 and H3K27me3 marks for selected genes. We found that the ES (Dicer-/-) mutant epigenome was characterized by a shift in the overall balance between transcriptionally favorable (H3K4me3) and unfavorable (H3K27me3) marks at key genes regulating ES cell differentiation. Pluripotency genes Oct4, Sox2 and Nanog were not impacted in relation to patterns of H3K27me3 and H3K4me3 and showed no changes in the rates of transcript down-regulation in response to RA. The most striking changes were observed in regards to genes regulating differentiation and the transition from self-renewal to differentiation. An increase in H3K4me3 at the promoter of Lin28b was associated with the down-regulation of this gene at a lower rate in Dicer-/-ES as compared to wild type ES. An increase in H3K27me3 in the promoters of differentiation genes Hoxa1 and Cdx2 in Dicer-/-ES cells was coincident with an inability to up-regulate these genes at the same rate as ES upon retinoic acid (RA)-induced differentiation. We found that siRNAs Ezh2 and post-transcriptional silencing of Ezh2 by let-7g rescued this effect suggesting that Ezh2 up-regulation is in part responsible for increased H3K27me3 and decreased rates of up-regulation of differentiation genes in Dicer-/-ES. PMID:24040281

  18. Potentiation of the teratogenic effects induced by coadministration of retinoic acid or phytanic acid/phytol with synthetic retinoid receptor ligands.

    PubMed

    Elmazar, M M A; Nau, H

    2004-11-01

    Previous studies in our laboratory identified retinoid-induced defects that are mediated by RAR-RXR heterodimerization using interaction of synthetic ligands selective for the retinoid receptors RAR and RXR in mice (Elmazar et al. 1997, Toxicol Appl Pharmacol 146:21-28; Elmazar et al. 2001, Toxicol Appl Pharmacol 170:2-9; Nau and Elmazar 1999, Handbook of experimental pharmacology, vol 139, Retinoids, Springer-Verlag, pp 465-487). The present study was designed to investigate whether these RAR-RXR heterodimer-mediated defects can be also induced by interactions of natural and synthetic ligands for retinoid receptors. A non-teratogenic dose of the natural RXR agonist phytanic acid (100 mg/kg orally) or its precursor phytol (500 mg/kg orally) was coadministered with a synthetic RARalpha-agonist (Am580; 5 mg/kg orally) to NMRI mice on day 8.25 of gestation (GD8.25). Furthermore, a non-teratogenic dose of the synthetic RXR agonist LGD1069 (20 mg/kg orally) was also coadministered with the natural RAR agonist, all- trans-retinoic acid (atRA, 20 mg/kg orally) or its precursor retinol (ROH, 50 mg/kg orally) to NMRI mice on GD8.25. The teratogenic outcome was scored in day-18 fetuses. The incidence of Am580-induced resorptions, spina bifida aperta, micrognathia, anotia, kidney hypoplasia, dilated bladder, undescended testis, atresia ani, short and absent tail, fused ribs and fetal weight retardation were potentiated by coadministration of phytanic acid or its precursor phytol. Am580-induced exencephaly and cleft palate, which were not potentiated by coadministration with the synthetic RXR agonists, were also not potentiated by coadministration with either phytanic acid or its precursor phytol. LGD1069 potentiated atRA- and ROH-induced resorption, exencephaly, spina bifida, aperta, ear anotia and microtia, macroglossia, kidney hypoplasia, undescended testis, atresia ani, tail defects and fetal weight retardation, but not cleft palate. These results suggest that synergistic

  19. A RARE of hepatic Gck promoter interacts with RARα, HNF4α and COUP-TFII that affect retinoic acid- and insulin-induced Gck expression.

    PubMed

    Li, Rui; Zhang, Rui; Li, Yang; Zhu, Bing; Chen, Wei; Zhang, Yan; Chen, Guoxun

    2014-09-01

    The expression of hepatic glucokinase gene (Gck) is regulated by hormonal and nutritional signals. How these signals integrate to regulate the hepatic Gck expression is unclear. We have shown that the hepatic Gck expression is affected by Vitamin A status and synergistically induced by insulin and retinoids in primary rat hepatocytes. We hypothesized that this is mediated by a retinoic acid responsive element (RARE) in the hepatic Gck promoter. Here, we identified the RARE in the hepatic Gck promoter using standard molecular biology techniques. The single nucleotide mutations affecting the promoter activation by retinoic acid (RA) were also determined for detail analysis of protein and DNA interactions. We have optimized experimental conditions for performing electrophoresis mobility shift assay and demonstrated the interactions of the retinoic acid receptor α (RARα), retinoid X receptor α (RXRα), hepatocyte nuclear factor 4α (HNF4α) and chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) in the rat nuclear extract with this RARE, suggesting their roles in the regulation of Gck expression. Chromatin immunoprecipitation assays demonstrated that recombinant adenovirus-mediated overexpression of RARα, HNF4α and COUP-TFII, but not RXRα, significantly increased their occupancy in the hepatic Gck promoter in primary rat hepatocytes. Overexpression of RARα, HNF4α and COUP-TFII, but not RXRα, also affected the RA- and insulin-mediated Gck expression in primary rat hepatocytes. In summary, this hepatic Gck promoter RARE interacts with RARα, HNF4α and COUP-TFII to integrate Vitamin A and insulin signals. PMID:24973045

  20. Eosinophils from Murine Lamina Propria Induce Differentiation of Naïve T Cells into Regulatory T Cells via TGF-β1 and Retinoic Acid

    PubMed Central

    Ojcius, David M.; Hu, Wei-Lin; Ge, Yu-Mei; Lin, Xu’ai; Li, Lan-Juan; Pan, Jian-Ping; Yan, Jie

    2015-01-01

    Treg cells play a crucial role in immune tolerance, but mechanisms that induce Treg cells are poorly understood. We here have described eosinophils in lamina propria (LP) that displayed high aldehyde dehydrogenase (ALDH) activity, a rate-limiting step during all-trans retinoic acid (ATRA) synthesis, and expressed TGF-β1 mRNA and high levels of ATRA. Co-incubation assay confirmed that LP eosinophils induced the differentiation of naïve T cells into Treg cells. Differentiation promoted by LP eosinophils were inhibited by blocked either TGF-β1 or ATRA. Peripheral blood (PB) eosinophils did not produce ATRA and could not induce Treg differentiation. These data identifies LP eosinophils as effective inducers of Treg cell differentiation through a mechanism dependent on TGF-β1 and ATRA. PMID:26587591

  1. Developmental expression of retinoic acid receptors (RARs)

    PubMed Central

    Dollé, Pascal

    2009-01-01

    Here, I review the developmental expression features of genes encoding the retinoic acid receptors (RARs) and the 'retinoid X' or rexinoid receptors (RXRs). The first detailed expression studies were performed in the mouse over two decades ago, following the cloning of the murine Rar genes. These studies revealed complex expression features at all stages of post-implantation development, one receptor gene (Rara) showing widespread expression, the two others (Rarb and Rarg) with highly regionalized and/or cell type-specific expression in both neural and non-neural tissues. Rxr genes also have either widespread (Rxra, Rxrb), or highly-restricted (Rxrg) expression patterns. Studies performed in zebrafish and Xenopus demonstrated expression of Rar and Rxr genes (both maternal and zygotic), at early pre-gastrulation stages. The eventual characterization of specific enzymes involved in the synthesis of retinoic acid (retinol/retinaldehyde dehydrogenases), or the triggering of its catabolism (CYP26 cytochrome P450s), all of them showing differential expression patterns, led to a clearer understanding of the phenomenons regulated by retinoic acid signaling during development. Functional studies involving targeted gene disruptions in the mouse, and additional approaches such as dominant negative receptor expression in other models, have pinpointed the specific, versus partly redundant, roles of the RARs and RXRs in many developing organ systems. These pleiotropic roles are summarized hereafter in relationship to the receptors’ expression patterns. PMID:19471585

  2. 9-cis-retinoic acid in combination with retinal pigment epithelium induces apoptosis in cultured retinal explants only during early postnatal development.

    PubMed

    Söderpalm, A K; Karlsson, J; Caffé, A R; vanVeen, T

    1999-12-10

    Retinoic acid is one of the active metabolites of vitamin A and has profound effects on the development of the CNS including retina. Previously, we have shown that rod-specific apoptosis is induced in retinal explants from neonatal mice by exposure to 9-cis-retinoic acid (9CRA) when the retinal pigment epithelium (RPE) is present. In explants lacking RPE, it instead has a differentiation-promoting effect seen as an accelerated opsin expression on postnatal day 3. To investigate the long-term effect of 9CRA exposure, we have explanted retinas from neonatal C3H mice with or without RPE attached and placed in organ culture. After 19 or 48 h in culture or 7, 8 or 13 days in culture, the explants were either fixed for histochemical examination or frozen for assay of DEVDase activity. We found that long-term exposure to 9CRA caused a decrease in the number of cell layers in the outer nuclear layer (ONL) only in explants with the RPE attached. When explants with RPE attached were exposed to 9CRA only during the second postnatal week, neither an increase in DEVDase activity, TUNEL-positive cells, nor a decrease in cell layers of the ONL could be demonstrated, indicating that the retina was insensitive to the apoptosis-inducing effect of 9CRA after the first postnatal week. The absence of RPE in control explants resulted in a higher number of rosettes and the extrusion of cells into the subretinal space. PMID:10611516

  3. Arsenic trioxide and all-trans retinoic acid target NPM1 mutant oncoprotein levels and induce apoptosis in NPM1-mutated AML cells.

    PubMed

    Martelli, Maria Paola; Gionfriddo, Ilaria; Mezzasoma, Federica; Milano, Francesca; Pierangeli, Sara; Mulas, Floriana; Pacini, Roberta; Tabarrini, Alessia; Pettirossi, Valentina; Rossi, Roberta; Vetro, Calogero; Brunetti, Lorenzo; Sportoletti, Paolo; Tiacci, Enrico; Di Raimondo, Francesco; Falini, Brunangelo

    2015-05-28

    Nucleophosmin (NPM1) mutations represent an attractive therapeutic target in acute myeloid leukemia (AML) because they are common (∼30% AML), stable, and behave as a founder genetic lesion. Oncoprotein targeting can be a successful strategy to treat AML, as proved in acute promyelocytic leukemia by treatment with all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO), which degrade the promyelocytic leukemia (PML)-retinoic acid receptor fusion protein. Adjunct of ATRA to chemotherapy was reported to be beneficial for NPM1-mutated AML patients. Leukemic cells with NPM1 mutation also showed sensibility to ATO in vitro. Here, we explore the mechanisms underlying these observations and show that ATO/ATRA induce proteasome-dependent degradation of NPM1 leukemic protein and apoptosis in NPM1-mutated AML cell lines and primary patients' cells. We also show that PML intracellular distribution is altered in NPM1-mutated AML cells and reverted by arsenic through oxidative stress induction. Interestingly, similarly to what was described for PML, oxidative stress also mediates ATO-induced degradation of the NPM1 mutant oncoprotein. Strikingly, NPM1 mutant downregulation by ATO/ATRA was shown to potentiate response to the anthracyclin daunorubicin. These findings provide experimental evidence for further exploring ATO/ATRA in preclinical NPM1-mutated AML in vivo models and a rationale for exploiting these compounds in chemotherapeutic regimens in clinics. PMID:25795919

  4. Induced expression of the new cytokine, activin A, in human monocytes: inhibition by glucocorticoids and retinoic acid.

    PubMed Central

    Yu, J; Shao, L E; Frigon, N L; Lofgren, J; Schwall, R

    1996-01-01

    The capacity of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF), glucocorticoids or all-trans-retinoic acid to modulate production of activin A by human monocytes was studied. It was shown that GM-CSF stimulated monocytes to accumulate activin A RNA after as few as 4 hr of incubation, reaching a peak of stimulation at approximately 16 hr of incubation. The activin A transcripts accumulated in the monocytes after stimulation with only 5 U/ml of GM-CSF and reached a maximum plateau level of expression between 25 and 50 U/ml of GM-CSF. Biologically active activin A molecules were detected in the conditioned media by a bioassay, performed both in the absence and presence of a neutralizing antiserum for activin A. Accumulation of bioactive activin A in conditioned medium of monocyte cultures was detected after 24 hr of incubation with GM-CSF and high levels of activin A were maintained for 72 hr. The production of the dimeric beta A beta A in these monocytes was further confirmed by sandwich enzyme-linked immunosorbent assay (ELISA) specific for activin A. In contrast to the stimulatory effect of GM-CSF, hydrocortisone, dexamethasone or all-trans-retinoic acid at 1 x 10(-7) to 1 x 10(-5) M inhibited the constitutive expression of activin A and greatly suppressed the GM-CSF-stimulated production. Thus, the expression of activin A is modulated in monocytes by different agents. These observations may imply new roles for activin A at sites of inflammation where monocytes accumulate. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:8774352

  5. Retinoic Acid Induces Ubiquitination-Resistant RIP140/LSD1 Complex to Fine-Tune Pax6 Gene in Neuronal Differentiation.

    PubMed

    Wu, Cheng-Ying; Persaud, Shawna D; Wei, Li-Na

    2016-01-01

    Receptor-interacting protein 140 (RIP140) is a wide-spectrum coregulator for hormonal regulation of gene expression, but its activity in development/stem cell differentiation is unknown. Here, we identify RIP140 as an immediate retinoic acid (RA)-induced dual-function chaperone for LSD1 (lysine-specific demethylase 1). RIP140 protects LSD1's catalytic domain and antagonizes its Jade-2-mediated ubiquitination and degradation. In RA-induced neuronal differentiation, the increased RIP140/LSD1 complex is recruited by RA-elevated Pit-1 to specifically reduce H3K4me2 modification on the Pax6 promoter, thereby repressing RA-induction of Pax6. This study reveals a new RA-induced gene repressive mechanism that modulates the abundance, enzyme quality, and recruitment of histone modifier LSD1 to neuronal regulator Pax6, which provides a homeostatic control for RA induction of neuronal differentiation. PMID:26372689

  6. Tolerability and Efficacy of Retinoic Acid Given after Full-face Peel Treatment of Photodamaged Skin

    PubMed Central

    Hu, Judy Y.; Biron, Julie A.; Yatskayer, Margarita; Dahl, Amanda; Oresajo, Christian

    2011-01-01

    Objective: All-trans retinoic acid is a well-established topical treatment of photodamaged skin. This study assessed the tolerance and efficacy of all-trans retinoic acid after full-face treatment with a chemical peel. Design: This was a split-face, randomized study. One side of each face was treated with peel and the other side with peel and all-trans retinoic acid (3%). Four treatments were given during the 10-week study period. Setting: Physician office. Participants: Fifteen female subjects 39 to 55 years of age. Measurements: Results were evaluated at Baseline; Weeks 4, 7, and 10; and at a 13-week follow-up visit by dermal grading of visual symptoms of irritation, subjective experiences of irritation, clinical grading of skin condition, and self-assessment questionnaires. Results: Both peel and peel plus all-trans retinoic acid treatments achieved significant improvement in fine lines, radiance, roughness, skin tone clarity, skin tone evenness, and hyperpigmentation appearance. Improvement in wrinkles and firmness was not observed in the peel plus all-trans retinoic acid arm, while pore appearance failed to improve in either treatment arm. Improvement in overall facial appearance was greater in the peel alone arm. Peel alone and the addition of all-trans retinoic acid did not cause dryness, edema, or peeling, and the frequency of peel-induced erythema did not increase with the addition of all-trans retinoic acid. Subject-perceived improvements with the peel treatment did not differ significantly from subject-perceived improvements of the peel plus all-trans retinoic acid treatment. Adverse events requiring intervention or discontinuing treatment were not observed in either treatment arm. Conclusion: The addition of all-trans retinoic acid after peel treatment does not significantly enhance peel-induced improvement in photoaging parameters, peel-induced adverse effects, and subject-perceived improvements. PMID:22010055

  7. Unbinding of Retinoic Acid from its Receptor Studied by Steered Molecular Dynamics

    NASA Astrophysics Data System (ADS)

    Kosztin, D.

    1999-01-01

    Retinoic acid receptor (RAR) is a ligand-dependent transcription factor that regulates the expression of genes involved in cell growth, differentiation, and development. Binding of the retinoic acid hormone to RAR is accompanied by conformational changes in the protein which induce transactivation or transrepression of the target genes. In this paper we present a study of the hormone binding/unbinding process in order to clarify the role of some of the amino acid contacts and identify possible pathways of the all-trans retinoic acid binding/unbinding to/from human retinoic acid receptor (hRAR)-g. Three possible pathways were explored using steered molecular dynamics simulations. Unbinding was induced on a time scale of 1 ns by applying external forces to the hormone. The simulations suggest that the hormone may employ one pathway for binding and an alternative "back door" pathway for unbinding.

  8. The combination of the antiestrogen endoxifen with all-trans-retinoic acid has anti-proliferative and anti-migration effects on melanoma cells without inducing significant toxicity in non-neoplasic cells.

    PubMed

    Ribeiro, Mariana P C; Silva, Filomena S G; Paixão, Joana; Santos, Armanda E; Custódio, José B A

    2013-09-01

    Melanoma incidence is dramatically increasing and the available treatments beyond partial efficacy have severe side effects. Retinoids are promising anticancer agents, but their clinical use has been limited by their toxicity, although a combination with other agents can possibly generate a therapeutic action at lower dosage. Thus, we investigated the effects of all-trans-retinoic acid combined with the antiestrogen endoxifen on melanoma cell proliferation and the effects were compared with its pro-drug tamoxifen. Moreover, we evaluated the effects of these combinations on non-neoplasic cells and assessed mitochondrial bioenergetic functions, to predict their potential toxicity. Individually, all-trans-retinoic acid and the antiestrogens endoxifen and tamoxifen decreased melanoma cell biomass, cell viability and DNA synthesis, without increased cell death, suggesting that the compounds inhibited cell proliferation. Noteworthy, endoxifen decreased cell proliferation more efficiently than tamoxifen. The combination of endoxifen with all-trans-retinoic acid enhanced the antiproliferative effects of the compounds individually more potently than tamoxifen, which did not enhance the effects induced by all-trans-retinoic acid alone, and blocked cell cycle progression in G1. Moreover, the combination of all-trans-retinoic acid with endoxifen significantly decreased melanoma cells migration, whereas the combination with tamoxifen did not present significant effects. At the concentrations used the compounds did not induce cytotoxicity in non-neoplasic cells and liver mitochondrial bioenergetic function was not affected. Altogether, our results show for the first time that a combined treatment of all-trans-retinoic acid with endoxifen may provide an anti-proliferative and anti-migration effect upon melanoma cells without major toxicity, offering a powerful therapeutic strategy for malignant melanoma. PMID:23712006

  9. ERAP140/Nbla10993 is a novel favorable prognostic indicator for neuroblastoma induced in response to retinoic acid.

    PubMed

    Arai, Hiroshi; Ozaki, Toshinori; Niizuma, Hidetaka; Nakamura, Yohko; Ohira, Miki; Takano, Kunio; Matsumoto, Masahiko; Nakagawara, Akira

    2008-06-01

    In the present study, we identified a gene termed Nbla10993 whose expression levels are higher in favorable neuroblastomas versus unfavorable ones. Structural analysis showed that Nbla10993 is a novel splicing variant of the ER-associated protein of 140 kDa (ERAP140), which lacks the central acidic as well as the COOH-terminal Cys/His-rich domain. Similarly, ERAP140 was preferentially expressed in favorable neuroblastomas relative to unfavorable ones. During the all-trans-retinoic acid (ATRA)-mediated neuronal differentiation in neuroblastoma-derived RTBM1 cells, the expression levels of ERAP140/Nbla10993 increased at the mRNA level. Consistent with these observations, the luciferase reporter analysis demonstrated that the ERAP140/Nbla10993 promoter responds to ATRA. In addition, the immunoprecipitation/immunoblotting experiments showed that ERAP140 forms a stable complex with RARalpha but not with RXRalpha in cells, suggesting that ERAP140 is involved in RAR-mediated transcriptional regulation. Furthermore, the quantitative real-time PCR analysis using 109 primary neuroblastoma samples demonstrated that the expression levels of ERAP140/Nbla10993 significantly correlate with a better clinical outcome of neuroblastomas. Taken together, our present findings indicate that ERAP140/Nbla10993 plays an important role in the regulation of ATRA-mediated neuronal differentiation, and is a novel member of prognostic indicators for neuroblastoma. PMID:18497940

  10. All-trans retinoic acid regulates hepatic bile acid homeostasis

    PubMed Central

    Yang, Fan; He, Yuqi; Liu, Hui-Xin; Tsuei, Jessica; Jiang, Xiaoyue; Yang, Li; Wang, Zheng-Tao; Wan, Yu-Jui Yvonne

    2014-01-01

    Retinoic acid (RA) and bile acids share common roles in regulating lipid homeostasis and insulin sensitivity. In addition, the receptor for RA (retinoid x receptor) is a permissive partner of the receptor for bile acids, farnesoid x receptor (FXR/NR1H4). Thus, RA can activate the FXR-mediated pathway as well. The current study was designed to understand the effect of all-trans RA on bile acid homeostasis. Mice were fed an all-trans RA-supplemented diet and the expression of 46 genes that participate in regulating bile acid homeostasis was studied. The data showed that all-trans RA has a profound effect in regulating genes involved in synthesis and transport of bile acids. All-trans RA treatment reduced the gene expression levels of Cyp7a1, Cyp8b1, and Akr1d1, which are involved in bile acid synthesis. All-trans RA also decreased the hepatic mRNA levels of Lrh-1 (Nr5a2) and Hnf4α (Nr2a1), which positively regulate the gene expression of Cyp7a1 and Cyp8b1. Moreover, all-trans RA induced the gene expression levels of negative regulators of bile acid synthesis including hepatic Fgfr4, Fxr, and Shp (Nr0b2) as well as ileal Fgf15. All-trans RA also decreased the expression of Abcb11 and Slc51b, which have a role in bile acid transport. Consistently, all-trans RA reduced hepatic bile acid levels and the ratio of CA/CDCA, as demonstrated by liquid chromatography-mass spectrometry. The data suggest that all-trans RA-induced SHP may contribute to the inhibition of CYP7A1 and CYP8B1, which in turn reduces bile acid synthesis and affects lipid absorption in the gastrointestinal tract. PMID:25175738

  11. All-Trans Retinoic Acid Induces Expression of a Novel Intergenic Long Noncoding RNA in Adult rat Primary Hippocampal Neurons.

    PubMed

    Kour, Sukhleen; Rath, Pramod C

    2016-02-01

    Around 90% of the mammalian genome undergoes pervasive transcription into various types of small and long regulatory noncoding RNAs, whereas only ∼ 1.5% codes for proteins. Long noncoding RNAs (lncRNAs) constitute diverse classes of sense- and antisense transcripts that are abundantly expressed in the mammalian central nervous system (CNS) in cell type- and developmental stage-specific manners. They are implicated in brain development, differentiation, neuronal plasticity, and other cognitive functions. Mammalian brain requires the vitamin A metabolite all-trans retinoic acid (atRA) for its normal development, differentiation, and cell-fate determination. However, its role in adult brain function is less understood. Here, we report atRA-mediated transcriptional upregulation of endogenous expression of a novel long intergenic noncoding RNA-rat brain expressed (LINC-RBE) in cultured primary hippocampal neurons from adult rat. We have previously reported LINC-RBE as an intergenic, simple repeat sequence containing lncRNA highly expressed in the rat brain. This is a first-time report of involvement of atRA in transcriptional upregulation of lncRNA expression in rat hippocampal neurons. Therefore, it may be involved in regulation of brain function and disease. PMID:26572536

  12. Retinoic acid induces caspase-8 transcription via phospho-CREB and increases apoptotic responses to death stimuli in neuroblastoma cells

    PubMed Central

    Jiang, Manrong; Zhu, Kejin; Grenet, Jose; Lahti, Jill M.

    2008-01-01

    Caspase-8 is frequently deleted or silenced in neuroblastoma and other solid tumor such as medulloblastoma and small cell lung carcinoma. Caspase-8 expression can be re-established in neuroblastoma cell lines by treatment with demethylating agents or with IFN-γ Here we show that four different retinoic acid (RA) derivatives also increase caspase-8 protein expression in neuroblastoma, medulloblastoma and small cell lung carcinoma cell lines. This increase in protein expression is mirrored by an increase in RNA expression in NB cells. However, the promoter region of the caspase-8 gene was not responsible for the induction of caspase-8 expression. Rather, we identified another intronic region containing a CREB binding site that was required for maximal induction of caspase-8 via RA. DNA-protein interaction assays revealed increased phospho-CREB binding to this response element in RA-treated NB cells. Furthermore, both mutation of the CREB binding site completely blocked caspase-8 induction in the luciferase reporter system assay and transfection of dominant-negative form of CREB repressed the up-regulation of caspase-8 by RA. Importantly, RA-released cells maintained caspase-8 expression for at least 2–5 days and were more sensitive to doxorubicin and TNFα. Thus, RA treatment in conjunction with TNFα and/or subsets of cytotoxic agents may have therapeutic benefits. PMID:18342014

  13. Retinoic Acid Receptors Control Spermatogonia Cell-Fate and Induce Expression of the SALL4A Transcription Factor.

    PubMed

    Gely-Pernot, Aurore; Raverdeau, Mathilde; Teletin, Marius; Vernet, Nadège; Féret, Betty; Klopfenstein, Muriel; Dennefeld, Christine; Davidson, Irwin; Benoit, Gérard; Mark, Manuel; Ghyselinck, Norbert B

    2015-10-01

    All-trans retinoic acid (ATRA) is instrumental to male germ cell differentiation, but its mechanism of action remains elusive. To address this question, we have analyzed the phenotypes of mice lacking, in spermatogonia, all rexinoid receptors (RXRA, RXRB and RXRG) or all ATRA receptors (RARA, RARB and RARG). We demonstrate that the combined ablation of RXRA and RXRB in spermatogonia recapitulates the set of defects observed both upon ablation of RAR in spermatogonia. We also show that ATRA activates RAR and RXR bound to a conserved regulatory region to increase expression of the SALL4A transcription factor in spermatogonia. Our results reveal that this major pluripotency gene is a target of ATRA signaling and that RAR/RXR heterodimers are the functional units driving its expression in spermatogonia. They add to the mechanisms through which ATRA promote expression of the KIT tyrosine kinase receptor to trigger a critical step in spermatogonia differentiation. Importantly, they indicate also that meiosis eventually occurs in the absence of a RAR/RXR pathway within germ cells and suggest that instructing this process is either ATRA-independent or requires an ATRA signal originating from Sertoli cells. PMID:26427057

  14. Retinoic Acid Receptors Control Spermatogonia Cell-Fate and Induce Expression of the SALL4A Transcription Factor

    PubMed Central

    Gely-Pernot, Aurore; Raverdeau, Mathilde; Teletin, Marius; Vernet, Nadège; Féret, Betty; Klopfenstein, Muriel; Dennefeld, Christine; Davidson, Irwin; Benoit, Gérard; Mark, Manuel; Ghyselinck, Norbert B.

    2015-01-01

    All-trans retinoic acid (ATRA) is instrumental to male germ cell differentiation, but its mechanism of action remains elusive. To address this question, we have analyzed the phenotypes of mice lacking, in spermatogonia, all rexinoid receptors (RXRA, RXRB and RXRG) or all ATRA receptors (RARA, RARB and RARG). We demonstrate that the combined ablation of RXRA and RXRB in spermatogonia recapitulates the set of defects observed both upon ablation of RAR in spermatogonia. We also show that ATRA activates RAR and RXR bound to a conserved regulatory region to increase expression of the SALL4A transcription factor in spermatogonia. Our results reveal that this major pluripotency gene is a target of ATRA signaling and that RAR/RXR heterodimers are the functional units driving its expression in spermatogonia. They add to the mechanisms through which ATRA promote expression of the KIT tyrosine kinase receptor to trigger a critical step in spermatogonia differentiation. Importantly, they indicate also that meiosis eventually occurs in the absence of a RAR/RXR pathway within germ cells and suggest that instructing this process is either ATRA-independent or requires an ATRA signal originating from Sertoli cells. PMID:26427057

  15. All-trans retinoic acid induces arginase-1 and inducible nitric oxide synthase-producing dendritic cells with T cell inhibitory function.

    PubMed

    Bhatt, Sumantha; Qin, Jie; Bennett, Carole; Qian, Shiguang; Fung, John J; Hamilton, Thomas A; Lu, Lina

    2014-06-01

    Hepatic stellate cells (HSC) are a major source of the immunoregulatory metabolite all-trans retinoic acid (ATRA), which may contribute to the generation of tolerogenic dendritic cells (DCs) in the liver. The present study seeks to clarify the mechanism(s) through which ATRA promotes the development of tolerogenic DCs. Although bone marrow-derived ATRA-treated DCs (RA-DCs) and conventional DCs had comparable surface phenotype, RA-DCs had diminished stimulatory capacity and could directly inhibit the expansion of DC/OVA-stimulated OT-II T cells. Arginase-1 (Arg-1) was found promote suppression because 1) ATRA was a potent inducer of Arg-1 protein and activity, 2) the Arg-1 inhibitor N(w)-hydroxy nor-l-arginine partially reversed suppression, and 3) the suppressive function of RA-DCs was partially compromised using OT-II T cells from GCN2(-/-) mice, which are insensitive to Arg-1. Inducible NO synthase (iNOS), however, was found to be a more significant contributor to RA-DC function because 1) ATRA potentiated the expression of IFN-γ-induced iNOS, 2) suppressive function in RA-DCs was blocked by the iNOS inhibitor N(G)-monomethyl-l-arginine, monoacetate salt, and 3) RA-DCs derived from iNOS(-/-) mice exhibited near complete loss of tolerogenic function, despite sustained Arg-1 activity. The expression of iNOS and the suppressive function of RA-DCs were dependent on both IFN-γ and ATRA. Furthermore, the in vivo behavior of RA-DCs proved to be consistent with their in vitro behavior. Thus, we conclude that ATRA enhances both Arg-1 and iNOS expression in IFN-γ-treated DCs, resulting in a tolerogenic phenotype. These findings elucidate mechanisms through which ATRA may contribute to liver immune tolerance. PMID:24790153

  16. Anchoring of both PKA-RIIα and 14-3-3θ regulates retinoic acid induced 16 mediated phosphorylation of heat shock protein 70

    PubMed Central

    Tang, Hai-Lin; Zhu, Shi-Ying; Zhao, Lan-Juan; Ren, Hao; Zhao, Ping; Qi, Zhong-Tian; Wang, Wen

    2015-01-01

    Our previous study reported that retinoic acid induced 16 (RAI16) could enhance tumorigenesis in hepatocellular carcinoma (HCC). However, the cellular functions of RAI16 are still unclear. In this study, by immunoprecipitation and tandem (MS/MS) mass spectrometry analysis, we identified that RAI16 interacted with the type II regulatory subunit of PKA (PKA-RIIα), acting as a novel protein kinase A anchoring protein (AKAP). In addition, RAI16 also interacted with heat shock protein 70 (HSP70) and 14-3-3θ. Further studies indicated that RAI16 mediated PKA phosphorylation of HSP70 at serine 486, resulting in anti-apoptosis events. RAI16 was also phosphorylated by the anchored PKA at serine 325, which promoted the recruitment of 14-3-3θ, which, in turn, inhibited RAI16 mediated PKA phosphorylation of HSP70. These findings offer mechanism insight into RAI16 mediated anti-apoptosis signaling in HCC. PMID:25900241

  17. Human B-cell lymphoma cell lines are highly sensitive to apoptosis induced by all-trans retinoic acid and interferon-gamma.

    PubMed

    Niitsu, Nozomi; Higashihara, Masaaki; Honma, Yoshio

    2002-08-01

    When cells were incubated in the presence of both interferon-gamma (IFN-gamma) and all-trans retinoic acid (ATRA), the concentration of IFN-gamma required to induce apoptosis of B-cell lymphoma cells was much lower than that required for myeloid or erythroid cell lines. The concentration of IFN-gamma that effectively inhibited the proliferation of BALM-3 cells was 1/40 of that required for BALM-1 cells. STAT-1 phosphorylation, IRF-1 mRNA and protein expression and RAR-beta expression were enhanced to a greater degree in BALM-3 cells treated with IFN-gamma and ATRA than in BALM-1 cells treated with IFN-gamma and ATRA, suggesting that these IFN-gamma related genes were involved in the induction of apoptosis of BALM-3 cells. PMID:12191570

  18. Retinoic acid: its biosynthesis and metabolism.

    PubMed

    Napoli, J L

    1999-01-01

    This article presents a model that integrates the functions of retinoid-binding proteins with retinoid metabolism. One of these proteins, the widely expressed (throughout retinoid target tissues and in all vertebrates) and highly conserved cellular retinol-binding protein (CRBP), sequesters retinol in an internal binding pocket that segregates it from the intracellular milieu. The CRBP-retinol complex appears to be the quantitatively major form of retinol in vivo, and may protect the promiscuous substrate from nonenzymatic degradation and/or non-specific enzymes. For example, at least seven types of dehydrogenases catalyze retinal synthesis from unbound retinol in vitro (NAD+ vs. NADP+ dependent, cytosolic vs. microsomal, short-chain dehydrogenases/reductases vs. medium-chain alcohol dehydrogenases). But only a fraction of these (some of the short-chain de-hydrogenases/reductases) have the fascinating additional ability of catalyzing retinal synthesis from CRBP-bound retinol as well. Similarly, CRBP and/or other retinoid-binding proteins function in the synthesis of retinal esters, the reduction of retinal generated from intestinal beta-carotene metabolism, and retinoic acid metabolism. The discussion details the evidence supporting an integrated model of retinoid-binding protein/metabolism. Also addressed are retinoid-androgen interactions and evidence incompatible with ethanol causing fetal alcohol syndrome by competing directly with retinol dehydrogenation to impair retinoic acid biosynthesis. PMID:10506831

  19. Nutrigenomic regulation of adipose tissue development - role of retinoic acid: A review.

    PubMed

    Wang, Bo; Yang, Qiyuan; Harris, Corrine L; Nelson, Mark L; Busboom, Jan R; Zhu, Mei-Jun; Du, Min

    2016-10-01

    To improve the efficiency of animal production, livestock have been extensively selected or managed to reduce fat accumulation and increase lean growth, which reduces intramuscular or marbling fat content. To enhance marbling, a better understanding of the mechanisms regulating adipogenesis is needed. Vitamin A has recently been shown to have a profound impact on all stages of adipogenesis. Retinoic acid, an active metabolite of vitamin A, activates both retinoic acid receptors (RAR) and retinoid X receptors (RXR), inducing epigenetic changes in key regulatory genes governing adipogenesis. Additionally, Vitamin D and folates interact with the retinoic acid receptors to regulate adipogenesis. In this review, we discuss nutritional regulation of adipogenesis, focusing on retinoic acid and its impact on epigenetic modifications of key adipogenic genes. PMID:27086067

  20. Biosynthesis and metabolism of retinoic acid: roles of CRBP and CRABP in retinoic acid: roles of CRBP and CRABP in retinoic acid homeostasis.

    PubMed

    Napoli, J L

    1993-02-01

    The enzymes that constitute the pathway of retinoic acid biosynthesis and metabolism may recognize retinoid binding proteins as effectors and substrates. Apocellular retinol-binding protein (CRBP) stimulates a bile-salt independent membrane-bound retinyl ester hydrolase resulting in the hydrolysis of endogenous retinyl esters and the formation of holoCRBP. HoloCRBP delivers retinol to a microsomal nicotin-amide-adenine dinucleotide phosphate-dependent dehydrogenase, protects it from artifactual oxidation and denies enzymes that cannot recognize the binding protein access to retinol. The retinal synthesized may be transferred from the microsomes to the cytosol by CRBP. A cytosolic retinal dehydrogenase has been purified that produces retinoic acid from retinal generated by microsomes in the presence of CRBP and from the complex CRBP-retinal itself. Thus, CRBP(type I) seems to channel retinoids through the reactions of retinoic acid synthesis via a series of protein-protein interactions. Cellular retinoic acid-binding protein (type I) facilitates retinoic acid metabolism by sequestering it and by acting as a low Km substrate, thereby also modulating the steady-state concentrations of retinoic acid. PMID:8381481

  1. Gene Expression Profiling Elucidates a Specific Role for RARγ in the Retinoic Acid Induced Differentiation of F9 Teratocarcinoma Stem Cells

    PubMed Central

    Su, Dan; Gudas, Lorraine J

    2010-01-01

    The biological effects of all-trans-retinoic acid (RA), a major active metabolite of retinol, are mainly mediated through its interactions with retinoic acid receptor (RARs α, β, γ) and retinoid X receptor (RXRs α, β, γ) heterodimers. RAR/RXR heterodimers activate transcription by binding to RA-response elements (RAREs or RXREs) in the promoters of primary target genes. Murine F9 teratocarcinoma stem cells have been widely used as a model for cellular differentiation and RA signaling during embryonic development. We identified and characterized genes that are differentially expressed in F9 wild type (Wt) and F9 RAR γ−/− cells, with and without RA treatment, through the use of oligonucleotide based microarrays. Our data indicate that RARγ, in the absence of exogenous RA, modulates gene expression. Genes such as Sfrp2, Tie1, Fbp2, Emp1, and Emp3 exhibited higher transcript levels in RA treated Wt, RARα−/− and RARβ2−/− lines than in RA-treated RARγ−/− cells, and represent specific RARγ targets. Other genes, such as Runx1, were expressed at lower levels in both F9 RARβ2−/− and RARγ−/− cell lines then in F9 Wt and RARα−/−. Genes specifically induced by RA at 6h with the protein synthesis inhibitor cycloheximide in F9 Wt, but not in RARγ−/− cells, included Hoxa3, Hoxa5, Gas1, Cyp26a1, Sfrp2, Fbp2, and Emp1. These genes represent specific primary RARγ targets in F9 cells. Several genes in the Wnt signaling pathway were regulated by RARγ. Delineation of the receptor specific actions of RA with respect to cell proliferation and differentiation should result in more effective therapies with this drug. PMID:18164278

  2. Metabolic Characterization of All-Trans-Retinoic Acid (ATRA)–Induced Craniofacial Development of Murine Embryos Using In Vivo Proton Magnetic Resonance Spectroscopy

    PubMed Central

    Peng, Lihong; Wu, Renhua; Hu, Xiao; Zhang, Guishan; Tang, Shijie

    2014-01-01

    Aim To characterize the abnormal metabolic profile of all-trans-retinoic acid (ATRA)–induced craniofacial development in mouse embryos using proton magnetic resonance spectroscopy (1H-MRS). Methods Timed-pregnant mice were treated by oral gavage on the morning of embryonic gestation day 11 (E11) with all-trans-retinoic acid (ATRA). Dosing solutions were adjusted by maternal body weight to provide 30, 70, or 100 mg/kg RA. The control group was given an equivalent volume of the carrier alone. Using an Agilent 7.0 T MR system and a combination of surface coil coils, a 3 mm×3 mm×3 mm 1H-MRS voxel was selected along the embryonic craniofacial tissue. 1H-MRS was performed with a single-voxel method using PRESS sequence and analyzed using LCModel software. Hematoxylin and eosin was used to detect and confirm cleft palate. Result 1H-MRS revealed elevated choline levels in embryonic craniofacial tissue in the RA70 and RA100 groups compared to controls (P<0.05). Increased choline levels were also found in the RA70 and RA100 groups compared with the RA30 group (P<0.01). High intra-myocellular lipids at 1.30 ppm (IMCL13) in the RA100 group compared to the RA30 group were found (P<0.01). There were no significant changes in taurine, intra-myocellular lipids at 2.10 ppm (IMCL21), and extra-myocellular lipids at 2.30 ppm (EMCL23). Cleft palate formation was observed in all fetuses carried by mice administered 70 and 100 mg/kg RA. Conclusions This novel study suggests that the elevated choline and lipid levels found by 1H-MRS may represent early biomarkers of craniofacial defects. Further studies will determine performance of this test and pathogenetic mechanisms of craniofacial malformation. PMID:24816763

  3. Characterization of DNA Binding and Retinoic Acid Binding Properties of Retinoic Acid Receptor

    NASA Astrophysics Data System (ADS)

    Yang, Na; Schule, Roland; Mangelsdorf, David J.; Evans, Ronald M.

    1991-05-01

    High-level expression of the full-length human retinoic acid receptor (RAR) α and the DNA binding domain of the RAR in Escherichia coli was achieved by using a T7 RNA polymerase-directed expression system. After induction, full-length RAR protein was produced at an estimated level of 20% of the total bacterial proteins. Both intact RAR molecules and the DNA binding domain bind to the cognate DNA response element with high specificity in the absence of retinoic acid. However, this binding is enhanced to a great extent upon the addition of eukaryotic cell extracts. The factor responsible for this enhancement is heat-sensitive and forms a complex with RAR that binds to DNA and exhibits a distinct migration pattern in the gel-mobility-shift assay. The interaction site of the factor with RAR is localized in the 70-amino acid DNA binding region of RAR. The hormone binding ability of the RARα protein was assayed by a charcoal absorption assay and the RAR protein was found to bind to retinoic acid with a K_d of 2.1 x 10-10 M.

  4. Tamoxifen enhances the differentiation-inducing and growth-inhibitory effects of all-trans retinoic acid in acute promyelocytic leukemia cells.

    PubMed

    Adachi, Koji; Honma, Yoshio; Miyake, Takaaki; Kawakami, Koshi; Takahashi, Tsutomu; Suzumiya, Junji

    2016-03-01

    All-trans retinoic acid (ATRA) is valuable in differentiation therapy for acute promyelocytic leukemia (APL). However, ATRA has had limited success as a single agent, due to the development of resistance. We found that tamoxifen effectively enhanced the differentiation-inducing effect of ATRA. Tamoxifen alone inhibited the proliferation of myeloid leukemia cell lines while only slightly increasing morphologic differentiation. Tamoxifen effectively enhanced the growth-inhibiting actions of various differentiation-inducing agents. ATRA in the presence of tamoxifen increased NBT reduction and the expression of CD11b in HL-60 cells more effectively than ATRA alone. Tamoxifen also enhanced the differentiation induced by the other inducers tested. ATRA induced the differentiation of APL cell lines NB4 and HT93 and APL cells in primary culture, and this differentiation was also enhanced by tamoxifen. Tamoxifen is one of the most widely used drugs for the treatment of cancer and has few side effects. The combination of ATRA and tamoxifen might be considered for the treatment of APL patients in whom it can be difficult to apply arsenic trioxide or anthracyclines. PMID:26797574

  5. Retinoic acid treated human dendritic cells induce T regulatory cells via the expression of CD141 and GARP which is impaired with age.

    PubMed

    Agrawal, Sudhanshu; Ganguly, Sreerupa; Tran, Alexander; Sundaram, Padmaja; Agrawal, Anshu

    2016-06-01

    Aged subjects display increased susceptibility to mucosal diseases. Retinoic Acid (RA) plays a major role in inducing tolerance in the mucosa. RA acts on Dendritic cells (DCs) to induce mucosal tolerance. Here we compared the response of DCs from aged and young individuals to RA with a view to understand the role of DCs in age-associated increased susceptibility to mucosal diseases. Our investigations revealed that compared to young DCs, RA stimulated DCs from aged subjects are defective in inducing IL-10 and T regulatory cells. Examinations of the underlying mechanisms indicated that RA exposure led to the upregulation of CD141 and GARP on DCs which rendered the DCs tolerogenic. CD141(hi), GARP(+) DCs displayed enhanced capacity to induce T regulatory cells compared to CD141(lo) and GARP(-) DCs. Unlike RA stimulated DCs from young, DCs from aged subjects exhibited diminished upregulation of both CD141 and GARP. The percentage of DCs expressing CD141 and GARP on RA treatment was significantly reduced in DCs from aged individuals. Furthermore, the remaining CD141(hi), GARP(+) DCs from aged individuals were also deficient in inducing T regs. In summary, reduced response of aged DCs to RA enhances mucosal inflammation in the elderly, increasing their susceptibility to mucosal diseases. PMID:27244900

  6. Retinoic acid treated human dendritic cells induce T regulatory cells via the expression of CD141 and GARP which is impaired with age

    PubMed Central

    Agrawal, Sudhanshu; Ganguly, Sreerupa; Tran, Alexander; Sundaram, Padmaja; Agrawal, Anshu

    2016-01-01

    Aged subjects display increased susceptibility to mucosal diseases. Retinoic Acid (RA) plays a major role in inducing tolerance in the mucosa. RA acts on Dendritic cells (DCs) to induce mucosal tolerance. Here we compared the response of DCs from aged and young individuals to RA with a view to understand the role of DCs in age-associated increased susceptibility to mucosal diseases. Our investigations revealed that compared to young DCs, RA stimulated DCs from aged subjects are defective in inducing IL-10 and T regulatory cells. Examinations of the underlying mechanisms indicated that RA exposure led to the upregulation of CD141 and GARP on DCs which rendered the DCs tolerogenic. CD141hi, GARP+ DCs displayed enhanced capacity to induce T regulatory cells compared to CD141lo and GARP− DCs. Unlike RA stimulated DCs from young, DCs from aged subjects exhibited diminished upregulation of both CD141 and GARP. The percentage of DCs expressing CD141 and GARP on RA treatment was significantly reduced in DCs from aged individuals. Furthermore, the remaining CD141hi, GARP+ DCs from aged individuals were also deficient in inducing T regs. In summary, reduced response of aged DCs to RA enhances mucosal inflammation in the elderly, increasing their susceptibility to mucosal diseases. PMID:27244900

  7. Anti-inflammatory roles of retinoic acid in rat brain astrocytes: Suppression of interferon-gamma-induced JAK/STAT phosphorylation.

    PubMed

    Choi, Woo-Hyuck; Ji, Kyung-Ae; Jeon, Sae-Bom; Yang, Myung-Soon; Kim, Ho; Min, Kyoung-Jin; Shong, Minho; Jou, Ilo; Joe, Eun-Hye

    2005-04-01

    The anti-inflammatory effect of retinoic acid (RA) has been investigated for several decades. However, the underlying mechanisms responsible for this effect are largely unknown. In this study, we demonstrate that 9-cis-RA (cRA) and all-trans-RA (tRA) inhibit interferon-gamma (IFN-gamma)-induced inflammatory responses in astrocytes. In primary cultured rat brain astrocytes and C6 astroglioma cells, both cRA and tRA decreased IFN-gamma-induced expression of interferon regulatory factor-1. Both RA isoforms also reduced IFN-gamma-induced activation of signal transducers and activators of transcription (STAT)1, STAT3, Janus kinase (JAK)1, and JAK2. This inhibitory effect was significant when cells were pre-treated with RA prior to IFN-gamma. Furthermore, the effect of pre-treated RA was abolished in the presence of cycloheximide, indicating a requirement for de novo protein synthesis. Suppressors of cytokine signaling (SOCS), which are negative regulators of the JAK/STAT pathway, may be candidate mediators of the anti-inflammatory function of RA. Both cRA and tRA induced SOCS3 mRNA expression. These results suggest that RA induces an anti-inflammatory effect by suppressing the activation of the JAK/STAT pathway in IFN-gamma-treated astrocytes. SOCS3 may be at least one of the mechanisms that mediate the anti-inflammatory roles of RA. PMID:15721283

  8. The Neurobiology of Retinoic Acid in Affective Disorders

    PubMed Central

    Bremner, J Douglas; McCaffery, Peter

    2009-01-01

    Current models of affective disorders implicate alterations in norepinephrine, serotonin, dopamine, and CRF/cortisol; however treatments targeted at these neurotransmitters or hormones have led to imperfect resolution of symptoms, suggesting that the neurobiology of affective disorders is incompletely understood. Until now retinoids have not been considered as possible contributors to affective disorders. Retinoids represent a family of compounds derived from Vitamin A that perform a large number of functions, many via the vitamin A product, retinoic acid. This signaling molecule binds to specific retinoic acid receptors in the brain which, like the glucocorticoid and thyroid hormone receptors, are part of the nuclear receptor superfamily and regulate gene transcription. Research in the field of retinoic acid in the CNS has focused on the developing brain, in part stimulated by the observation that isotretinoin (13-cis retinoic acid), an isomer of retinoic acid used in the treatment of acne, is highly teratogenic for the CNS. More recent work has suggested that retinoic acid may influence the adult brain; animal studies indicated that the administration of isotretinoin is associated with alterations in behavior as well as inhibition of neurogenesis in the hippocampus. Clinical evidence for an association between retinoids and depression includes case reports in the literature, studies of health care databases, and other sources. A preliminary PET study in human subjects showed that isotretinoin was associated with a decrease in orbitofrontal metabolism. Several studies have shown that the molecular components required for retinoic acid signaling are expressed in the adult brain ; the overlap of brain areas implicated in retinoic acid function and stress and depression suggest that retinoids could play a role in affective disorders. This report reviews the evidence in this area and describes several systems that may be targets of retinoic acid and which contribute

  9. EMBO Retinoids 2011: mechanisms, biology and pathology of signaling by retinoic acid and retinoic acid receptors

    PubMed Central

    McKenna, Neil J.

    2012-01-01

    Retinoic acid (RA) is one of the principal active metabolites of vitamin A (retinol) which mediates a spectrum of critical physiological and developmental processes. Transcriptional regulation by RA is mediated primarily by members of the retinoic acid receptor (RAR) subfamily of the nuclear receptor (NR) superfamily of transcription factors. NRs bind specific genomic DNA sequence motifs and engage coregulators and components of the basal transcription machinery to effect transcriptional regulation at target gene promoters. Disruption of signaling by retinoic acid is thought to underlie the etiology of a number of inflammatory and neoplastic diseases including breast cancer and haematological malignancies. A meeting of international researchers in retinoid signaling was convened in Strasbourg in September 2011 under the auspices of the European Molecular Biology Organization (EMBO). Retinoids 2011 encompassed myriad mechanistic, biological and pathological aspects of these hormones and their cognate receptors, as well as setting these advances in the context of wider current questions on signaling by members of the NR superfamily. PMID:22438793

  10. Retinoic acid expands the evolutionarily reduced dentition of zebrafish

    PubMed Central

    Seritrakul, Pawat; Samarut, Eric; Lama, Tenzing T. S.; Gibert, Yann; Laudet, Vincent; Jackman, William R.

    2012-01-01

    Zebrafish lost anterior teeth during evolution but retain a posterior pharyngeal dentition that requires retinoic acid (RA) cell-cell signaling for its development. The purposes of this study were to test the sufficiency of RA to induce tooth development and to assess its role in evolution. We found that exposure of embryos to exogenous RA induces a dramatic anterior expansion of the number of pharyngeal teeth that later form and shifts anteriorly the expression patterns of genes normally expressed in the posterior tooth-forming region, such as pitx2 and dlx2b. After RA exposure, we also observed a correlation between cartilage malformations and ectopic tooth induction, as well as abnormal cranial neural crest marker gene expression. Additionally, we observed that the RA-induced zebrafish anterior teeth resemble in pattern and number the dentition of fish species that retain anterior pharyngeal teeth such as medaka but that medaka do not express the aldh1a2 RA-synthesizing enzyme in tooth-forming regions. We conclude that RA is sufficient to induce anterior ectopic tooth development in zebrafish where teeth were lost in evolution, potentially by altering neural crest cell development, and that changes in the location of RA synthesis correlate with evolutionary changes in vertebrate dentitions.—Seritrakul, P., Samarut, E., Lama, T. T. S., Gibert, Y., Laudet, V., Jackman, W. R. Retinoic acid expands the evolutionarily reduced dentition of zebrafish. PMID:22942074

  11. Retinoic Acid in the Immune System

    PubMed Central

    Pino-Lagos, Karina; Benson, Micah J.; Noelle, Randolph J.

    2013-01-01

    On occasion, emerging scientific fields intersect and great discoveries result. In the last decade, the discovery of regulatory T cells (Treg) in immunity has revolutionized our understanding of how the immune system is controlled. Intersecting the rapidly emerging field of Treg function, has been the discovery that retinoic acid (RA) controls both the homing and differentiation of Treg. Instantly, the wealth and breadth of knowledge of the molecular basis for RA action, its receptors, and how it controls cellular differentiation can and will be exploited to understand its profound effects on Treg. Historically, vitamin A deprivation and repletion and RA agonists have been shown to profoundly affect immunity. Now these findings can be interpreted in light of the revelations that RA controls leukocyte homing and Treg function. PMID:19076350

  12. Sex specific retinoic acid signaling is required for the initiation of urogenital sinus bud development.

    PubMed

    Bryant, Sarah L; Francis, Jeffrey C; Lokody, Isabel B; Wang, Hong; Risbridger, Gail P; Loveland, Kate L; Swain, Amanda

    2014-11-15

    The mammalian urogenital sinus (UGS) develops in a sex specific manner, giving rise to the prostate in the male and the sinus vagina in the embryonic female. Androgens, produced by the embryonic testis, have been shown to be crucial to this process. In this study we show that retinoic acid signaling is required for the initial stages of bud development from the male UGS. Enzymes involved in retinoic acid synthesis are expressed in the UGS mesenchyme in a sex specific manner and addition of ligand to female tissue is able to induce prostate-like bud formation in the absence of androgens, albeit at reduced potency. Functional studies in mouse organ cultures that faithfully reproduce the initiation of prostate development indicate that one of the roles of retinoic acid signaling in the male is to inhibit the expression of Inhba, which encodes the βA subunit of Activin, in the UGS mesenchyme. Through in vivo genetic analysis and culture studies we show that inhibition of Activin signaling in the female UGS leads to a similar phenotype to that of retinoic acid treatment, namely bud formation in the absence of androgens. Our data also reveals that both androgens and retinoic acid have extra independent roles to that of repressing Activin signaling in the development of the prostate during fetal stages. This study identifies a novel role for retinoic acid as a mesenchymal factor that acts together with androgens to determine the position and initiation of bud development in the male UGS epithelia. PMID:25261715

  13. Activation of Notch1 inhibits medial edge epithelium apoptosis in all-trans retinoic acid-induced cleft palate in mice.

    PubMed

    Zhang, Yadong; Dong, Shiyi; Wang, Weicai; Wang, Jianning; Wang, Miao; Chen, Mu; Hou, Jinsong; Huang, Hongzhang

    2016-08-26

    Administration of all-trans retinoic acid (atRA) on E12.0 (embryonic day 12.0) leads to failure of medial edge epithelium (MEE) disappearance and cleft palate. However, the molecular mechanism underlying the relationship between atRA and MEE remains to be identified. In this study, atRA (200 mg/kg) administered by gavage induced a 75% incidence of cleft palate in C57BL/6 mice. Notch1 was up-regulated in MEE cells in the atRA-treated group compared with the controls at E15.0, together with reduced apoptosis and elevated proliferation. Next, we investigated the mechanisms underlying atRA, Notch1 and MEE degradation in palate organ culture. Our results revealed that down-regulation of Notch1 partially rescued the inhibition of atRA-induced palate fusion. Molecular analysis indicated that atRA increased the expression of Notch1 and Rbpj and decreased the expression of P21. In addition, depletion of Notch1 expression decreased the expression of Rbpj and increased the expression of P21. Moreover, inhibition of Rbpj expression partially reversed atRA-induced MEE persistence and increased P21 expression. These findings demonstrate that atRA inhibits MEE degradation, which in turn induces a cleft palate, possibly through the Notch1/RBPjk/P21 signaling pathway. PMID:27343556

  14. c-Myc-mediated expression of nucleophosmin/B23 decreases during retinoic acid-induced differentiation of human leukemia HL-60 cells.

    PubMed

    Yung, Benjamin Y M

    2004-12-17

    The retinoic acid-induced differentiation of human leukemia HL-60 cells towards mature granulocytic cells was accompanied by the decline in the protein levels of c-myc, nucleophosmin/B23 and its promoter activity. These RA-induced effects were further enhanced by the concurrent treatment of HL-60 cells with p38 map kinase inhibitor SB203580 (SB). It seems that there is a strong correlation of nucleophosmin/B23 and c-Myc expressions in cells under RA treatment. Furthermore, nucleophosmin/B23 promoter activity decreased upon c-Myc antisense-mediated reduction of intracellular amount of c-Myc. CHIP assays showed that binding of c-Myc to the nucleophosmin/B23 promoter decreased in RA-treated cells. Thus, nucleophosmin/B23 expression is targeted by c-Myc during RA-induced differentiation. These results provide evidence for a novel mechanism of transcriptional downregulation of nucleophosmin/B23 and the functional role of c-Myc in RA-induced differentiation. PMID:15589822

  15. All-trans retinoic acid regulates the expression of apolipoprotein E in rats with glomerulosclerosis induced by Adriamycin.

    PubMed

    Zhou, Tian-Biao; Qin, Yuan-Han; Lei, Feng-Ying; Su, Li-Na; Zhao, Yan-Jun; Huang, Wei-Fang

    2011-06-01

    Apolipoprotein E (apoE) is an important plasma protein in cholesterol homeostasis and plays a key role in the progression of glomerulosclerosis (GS). We conducted this investigation to explore whether all-trans retinoic acid (ATRA) could regulate the apoE expression in the pathological process of GS. 120 Wistar rats were divided into three groups at random: sham operation group (SHO), glomerulosclerosis model group without treatment (GS), GS model group treated with ATRA (GA); n=40, respectively. The disease of GS in rat was established by uninephrectomy and adriamycin (5mg/kg) injection. At the end of 9 and 13 weeks, 20 rats in each group were killed and the relevant samples were collected. 24-hour urine total protein (24UTP), 24-hour urine excretion for albumin (24Ualb), serum total protein (TP) and serum albumin (Alb), blood urea nitrogen (BUN), serum creatinine (Scr), total cholesterol (TC), triglyceride (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL), serum and urine apoE and glomerulosclerosis index (GSI) were measured. The protein expressions of collagen IV (Col-IV), fibronectin (FN) and apoE in glomeruli were determined by immunohistochemistry. Real-time reverse transcription polymerase chain reaction (real-time RT-PCR) was used to detect the expression of apoE mRNA in kidney. TP and Alb in GA group in 9/13-week were increased than those of GS group, however, the differences were not statistically significant. Compared with group GS at 9/13 weeks, values of 24UTP, 24Ualb, BUN, Scr, TC, TG, HDL, LDL, serum and urine apoE, and GSI in GA group that were significantly reduced, and protein expressions of Col-IV, FN and apoE in glomeruli and expression of apoE mRNA in renal tissue were significantly down-regulated by ATRA (P<0.01). In conclusion, ATRA can regulate the expression of apoE, reduce the accumulation of extracellular matrix (ECM) and step down the progression of GS. PMID:21385580

  16. A third human retinoic acid receptor, hRAR-. gamma

    SciTech Connect

    Krust, A.; Kastner, Ph.; Petkovich, M.; Zelent, A.; Chambon, P. )

    1989-07-01

    Retinoic acid receptors (RARs) are retinoic acid (RA)-inducible enhancer factors belonging to the superfamily of steroid/thyroid nuclear receptors. The authors have previously characterized two human RAR (hRAR-{alpha} and hRAR-{beta}) cDNAs and have recently cloned their murine cognates (mRAR-{alpha} and mRAR-{beta}) together with a third RAR (mRAR-{gamma}) whose RNA was detected predominantly in skin, a well-known target for RA. mRAR-{gamma} cDNA was used here to clone its human counterpart (hRAR-{gamma}) from a T47D breast cancer cell cDNA library. Using a transient transfection assay in HeLa cells and a reporter gene harboring a synthetic RA responsive element, they demonstrate that hRAR-{gamma} cDNA indeed encodes a RA-inducible transcriptional trans-activator. Interestingly, comparisons of the amino acid sequences of all six human and mouse RARs indicate that the interspecies conservation of a given member of the RAR subfamily (either {alpha}, {beta}, or {gamma}) is much higher than the conservation of all three receptors within a given species. These observations indicate that RAR-{alpha}, -{beta}, and -{gamma} may perform specific functions. They show also that hRAR-{gamma} RNA is the predominant RAR RNA species in human skin, which suggests that hRAR-{gamma} mediates some of the retinoid effects in this tissue.

  17. Antiviral activity of human oligoadenylate synthetases-like (OASL) is mediated by enhancing retinoic acid-inducible gene I (RIG-I) signaling

    PubMed Central

    Zhu, Jianzhong; Zhang, Yugen; Ghosh, Arundhati; Cuevas, Rolando A.; Forero, Adriana; Dhar, Jayeeta; Ibsen, Mikkel Søes; Schmid-Burgk, Jonathan Leo; Schmidt, Tobias; Ganapathiraju, Madhavi K.; Fujita, Takashi; Hartmann, Rune; Barik, Sailen; Hornung, Veit; Coyne, Carolyn B.; Sarkar, Saumendra N.

    2014-01-01

    SUMMARY Virus infection is sensed in the cytoplasm by retinoic acid-inducible gene I (RIG-I, also known as DDX58), which requires RNA and polyubiquitin binding to induce type I interferon (IFN), and activate cellular innate immunity. We show that the human IFN-inducible oligoadenylate synthetases-like (OASL) protein had antiviral activity and mediated RIG-I activation by mimicking polyubiquitin. Loss of OASL expression reduced RIG-I signaling and enhanced virus replication in human cells. Conversely, OASL expression suppressed replication of a number of viruses in a RIG-I-dependent manner and enhanced RIG-I-mediated IFN induction. OASL interacted and colocalized with RIG-I, and through its C-terminal ubiquitin-like domain specifically enhanced RIG-I signaling. Bone marrow derived macrophages from mice deficient for Oasl2 showed that among the two mouse orthologs of human OASL; Oasl2 is functionally similar to human OASL. Our findings show a mechanism by which human OASL contributes to host antiviral responses by enhancing RIG-I activation. PMID:24931123

  18. Retinoic Acid Induced-Autophagic Flux Inhibits ER-Stress Dependent Apoptosis and Prevents Disruption of Blood-Spinal Cord Barrier after Spinal Cord Injury

    PubMed Central

    Zhou, Yulong; Zhang, Hongyu; Zheng, Binbin; Ye, Libing; Zhu, Sipin; Johnson, Noah R; Wang, Zhouguang; Wei, Xiaojie; Chen, Daqing; Cao, Guodong; Fu, Xiaobing; Li, Xiaokun; Xu, Hua-Zi; Xiao, Jian

    2016-01-01

    Spinal cord injury (SCI) induces the disruption of the blood-spinal cord barrier (BSCB) which leads to infiltration of blood cells, an inflammatory response, and neuronal cell death, resulting spinal cord secondary damage. Retinoic acid (RA) has a neuroprotective effect in both ischemic brain injury and SCI, however the relationship between BSCB disruption and RA in SCI is still unclear. In this study, we demonstrated that autophagy and ER stress are involved in the protective effect of RA on the BSCB. RA attenuated BSCB permeability and decreased the loss of tight junction (TJ) molecules such as P120, β-catenin, Occludin and Claudin5 after injury in vivo as well as in Brain Microvascular Endothelial Cells (BMECs). Moreover, RA administration improved functional recovery in the rat model of SCI. RA inhibited the expression of CHOP and caspase-12 by induction of autophagic flux. However, RA had no significant effect on protein expression of GRP78 and PDI. Furthermore, combining RA with the autophagy inhibitor chloroquine (CQ) partially abolished its protective effect on the BSCB via exacerbated ER stress and subsequent loss of tight junctions. Taken together, the neuroprotective role of RA in recovery from SCI is related to prevention of of BSCB disruption via the activation of autophagic flux and the inhibition of ER stress-induced cell apoptosis. These findings lay the groundwork for future translational studies of RA for CNS diseases, especially those related to BSCB disruption. PMID:26722220

  19. Retinoic acid-inducible gene-I-like receptor (RLR)-mediated antiviral innate immune responses in the lower respiratory tract: Roles of TRAF3 and TRAF5.

    PubMed

    Chiba, Yuki; Matsumiya, Tomoh; Satoh, Tsugumi; Hayakari, Ryo; Furudate, Ken; Xing, Fei; Yoshida, Hidemi; Tanji, Kunikazu; Mizukami, Hiroki; Imaizumi, Tadaatsu; Ito, Etsuro

    2015-11-13

    Upon viral infection, the cytoplasmic viral sensor retinoic acid-inducible gene-I (RIG-I) recognizes viral RNA to activate antiviral signaling to induce type I interferon (IFN). RIG-I-like receptors (RLRs) activate antiviral signaling in a tissue-specific manner. The molecular mechanism underlying antiviral signaling in the respiratory system remains unclear. We studied antiviral signaling in the lower respiratory tract (LRT), which is the site of many harmful viral infections. Epithelial cells of the LRT can be roughly divided into two groups: bronchial epithelial cells (BECs) and pulmonary alveolar epithelial cells (AECs). These two cell types exhibit different phenotypes; therefore, we hypothesized that these cells may play different roles in antiviral innate immunity. We found that BECs exhibited higher antiviral activity than AECs. TNF receptor-associated factor 3 (TRAF3) has been shown to be a crucial molecule in RLR signaling. The expression levels of TRAF3 and TRAF5, which have conserved domains that are nearly identical, in the LRT were examined. We found that the bronchus exhibited the highest expression levels of TRAF3 and TRAF5 in the LRT. These findings suggest the importance of the bronchus in antiviral innate immunity in the LRT and indicate that TRAF3 and TRAF5 may contribute to RLR signaling. PMID:26454171

  20. MicroRNA-31 negatively regulates peripherally derived regulatory T-cell generation by repressing retinoic acid-inducible protein 3.

    PubMed

    Zhang, Lingyun; Ke, Fang; Liu, Zhaoyuan; Bai, Jing; Liu, Jinlin; Yan, Sha; Xu, Zhenyao; Lou, Fangzhou; Wang, Hong; Zhu, Huiyuan; Sun, Yang; Cai, Wei; Gao, Yuanyuan; Li, Qun; Yu, Xue-Zhong; Qian, Youcun; Hua, Zichun; Deng, Jiong; Li, Qi-Jing; Wang, Honglin

    2015-01-01

    Peripherally derived regulatory T (pT(reg)) cell generation requires T-cell receptor (TCR) signalling and the cytokines TGF-β1 and IL-2. Here we show that TCR signalling induces the microRNA miR-31, which negatively regulates pT(reg)-cell generation. miR-31 conditional deletion results in enhanced induction of pT(reg) cells, and decreased severity of experimental autoimmune encephalomyelitis (EAE). Unexpectedly, we identify Gprc5a as a direct target of miR-31. Gprc5a is known as retinoic acid-inducible protein 3, and its deficiency leads to impaired pT(reg-)cell induction and increased EAE severity. By generating miR-31 and Gprc5a double knockout mice, we show that miR-31 promotes the development of EAE through inhibiting Gprc5a. Thus, our data identify miR-31 and its target Gprc5a as critical regulators for pT(reg)-cell generation, suggesting a previously unrecognized epigenetic mechanism for dysfunctional T(reg) cells in autoimmune diseases. PMID:26165721

  1. Induction of autophagy is a key component of all-trans-retinoic acid-induced differentiation in leukemia cells and a potential target for pharmacologic modulation.

    PubMed

    Orfali, Nina; O'Donovan, Tracey R; Nyhan, Michelle J; Britschgi, Adrian; Tschan, Mario P; Cahill, Mary R; Mongan, Nigel P; Gudas, Lorraine J; McKenna, Sharon L

    2015-09-01

    Acute myeloid leukemia (AML) is characterized by the accumulation of immature blood cell precursors in the bone marrow. Pharmacologically overcoming the differentiation block in this condition is an attractive therapeutic avenue, which has achieved success only in a subtype of AML, acute promyelocytic leukemia (APL). Attempts to emulate this success in other AML subtypes have thus far been unsuccessful. Autophagy is a conserved protein degradation pathway with important roles in mammalian cell differentiation, particularly within the hematopoietic system. In the study described here, we investigated the functional importance of autophagy in APL cell differentiation. We found that autophagy is increased during all-trans-retinoic acid (ATRA)-induced granulocytic differentiation of the APL cell line NB4 and that this is associated with increased expression of LC3II and GATE-16 proteins involved in autophagosome formation. Autophagy inhibition, using either drugs (chloroquine/3-methyladenine) or short-hairpin RNA targeting the essential autophagy gene ATG7, attenuates myeloid differentiation. Importantly, we found that enhancing autophagy promotes ATRA-induced granulocytic differentiation of an ATRA-resistant derivative of the non-APL AML HL60 cell line (HL60-Diff-R). These data support the development of strategies to stimulate autophagy as a novel approach to promote differentiation in AML. PMID:25986473

  2. Neutrophils are immune cells preferentially targeted by retinoic acid in elderly subjects

    PubMed Central

    2010-01-01

    Background The immune system gradually deteriorates with age and nutritional status is a major factor in immunosenescence. Of the many nutritional factors implicated in age-related immune dysfunction, vitamin A may be a good candidate, since vitamin A concentrations classically decrease during aging whereas it may possess important immunomodulatory properties via its active metabolites, the retinoic acids. This prompted us to investigate the immune response induced by retinoids in adults and elderly healthy subjects. Before and after oral supplementation with 13cis retinoic acid (0.5 mg/kg/day during 28 days), whole blood cells were phenotyped, and functions of peripheral blood mononuclear cells (PBMC) and polymorphonuclear cells (PMN) were investigated by flow cytometry and ELISA tests. Results In both young adults (n = 20, 25 ± 4 years) and older subjects (n = 20, 65 ± 4 years), retinoic acid supplementation had no effect on the distribution of leukocyte subpopulations or on the functions of PBMC (Il-2 and sIl-2R production, membrane expression of CD25). Concerning PMN, retinoic acid induced an increase in both spontaneous migration and cell surface expression of CD11b in the two different age populations, whereas bactericidal activity and phagocytosis remained unchanged. Conclusions We demonstrated that retinoic acid induces the same intensity of immune response between adult and older subjects, and more specifically affects PMN functions, i.e. adhesion and migration, than PBMC functions. PMID:20727130

  3. Retinoic Acid Protects Cardiomyocytes from High Glucose-Induced Apoptosis via Inhibition of Sustained Activation of NF-κB Signaling

    PubMed Central

    Nizamutdinova, Irina T.; Guleria, Rakeshwar S.; Singh, Amar B.; Kendall, Jonathan A.; Baker, Kenneth M.; Pan, Jing

    2012-01-01

    We have previously shown that retinoic acid (RA) has protective effects on high glucose (HG)-induced cardiomyocyte apoptosis. To further elucidate the molecular mechanisms of RA effects, we determined the interaction between nuclear factor (NF)-κB and RA signaling. HG induced a sustained phosphorylation of IKK/IκBα and transcriptional activation of NF-κB in cardiomyocytes. Activated NF-κB signaling has an important role in HG-induced cardiomyocyte apoptosis and gene expression of interleukin-6 (IL-6), tumor necrosis factor (TNF)-α and monocyte chemoattractant protein-1 (MCP-1). All-trans RA (ATRA) and LGD1069, through activation of RAR/RXR-mediated signaling, inhibited the HG-mediated effects in cardiomyocytes. The inhibitory effect of RA on NF-κB activation was mediated through inhibition of IKK/IκBα phosphorylation. ATRA and LGD1069 treatment promoted protein phosphatase 2A (PP2A) activity, which was significantly suppressed by HG stimulation. The RA effects on IKK and IκBα were blocked by okadaic acid or silencing the expression of PP2Ac-subunit, indicating that the inhibitory effect of RA on NF-κB is regulated through activation of PP2A and subsequent dephosphorylation of IKK/IκBα. Moreover, ATRA and LGD1069 reversed the decreased PP2A activity and inhibited the activation of IKK/IκBα and gene expression of MCP-1, IL-6 and TNF-α in the hearts of Zucker diabetic fatty rats. In summary, our findings suggest that the suppressed activation of PP2A contributed to sustained activation of NF-κB in HG-stimulated cardiomyocytes; and that the protective effect of RA on hyperglycemia-induced cardiomyocyte apoptosis and inflammatory responses is partially regulated through activation of PP2A and suppression of NF-κB-mediated signaling and downstream targets. PMID:22718360

  4. Identification of a retinoic acid-inducible gene I from Japanese eel (Anguilla japonica) and expression analysis in vivo and in vitro.

    PubMed

    Feng, Jianjun; Guo, Songlin; Lin, Peng; Wang, Yilei; Zhang, Ziping; Zhang, Zaipeng; Yu, Lili

    2016-08-01

    RIG-I (retinoic acid inducible gene-I) is one of the key cytosolic pattern recognition receptors (PRRs) for the recognition of cytosolic viral nucleic acids and the production of type I interferons (IFNs). The full-length cDNA sequence of RIG-I (AjRIG-I) in Japanese eel (Anguilla japonica) was identified and characterized in this article. The full-length cDNA of AjRIG-I was 3468 bp, including a 5'-untranslated region (UTR) of 52 bp, a 3'-UTR of 617 bp and an open reading frame (ORF) of 2799 bp encoding a polypeptide of 933 amino acid residues with a calculated molecular mass of 106.2 kDa. NCBI CDD analysis showed that the AjRIG-I protein had the typical conserved domains, including two adjacent caspase activation and recruitment domains (CARDs), a DEXDc domain, a HELICc domain and a C-terminal regulatory domain (RD). Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed a broad expression for AjRIG-I in a wide range of tissues, with the predominant expression in liver, followed by the gills, spleen, kidney, intestine, skin, and the very low expression in muscle and heart. The AjRIG-I expressions in liver, spleen and kidney were significantly induced following injection with LPS, the viral mimic poly I:C, and Aeromonas hydrophila infection. In vitro, the AjRIG-I transcripts of Japanese eel liver cells were significantly enhanced by poly I:C and PGN stimulation, down-regulated with CpG-DNA treatment whereas no change of the expression level was found post LPS challenge. These results collectively suggested AjRIG-I transcripts expression possibly play an important role in fish defense against viral and bacterial infection. PMID:27238428

  5. SPLUNC1 is associated with nasopharyngeal carcinoma prognosis and plays an important role in all-trans-retinoic acid-induced growth inhibition and differentiation in nasopharyngeal cancer cells.

    PubMed

    Zhang, Wenling; Zeng, Zhaoyang; Wei, Fang; Chen, Pan; Schmitt, David C; Fan, Songqing; Guo, Xiaofang; Liang, Fang; Shi, Lei; Liu, Zixin; Zhang, Zuping; Xiang, Bo; Zhou, Ming; Huang, Donghai; Tang, Ke; Li, Xiaoling; Xiong, Wei; Tan, Ming; Li, Guiyuan; Li, Xiayu

    2014-11-01

    Human SPLUNC1 can suppress nasopharyngeal carcinoma (NPC) tumor formation; however, the correlation between SPLUNC1expression and NPC patient prognosis has not been reported. In the present study, we used a large-scale sample of 1015 tissue cores to detect SPLUNC1 expression and its association with patient prognosis. SPLUNC1 expression was reduced in NPC samples compared to nontumor nasopharyngeal epithelium tissues. Positive expression of SPLUNC1 in NPC predicted a better prognosis (disease-free survival, P = 0.034; overall survival, P = 0.048). Cox's proportional hazards model revealed that SPLUNC1 could be a significant prognostic factor affecting disease-free survival (P = 0.027). A cDNA micro-array analyzed by significant analysis of micro-array (SAM) and ingenuity pathway analysis (IPA) revealed that an indirect interaction existed between SPLUNC1 and retinoic acid (RA) in the cancer regulatory network. To further investigate the molecular mechanisms involved, we utilized several bioinformatics tools and identified 12 retinoid X receptors heterodimer binding sites in the promoter region of the SPLUNC1 gene. The transcriptional activity of the SPLUNC1 promoter was up-regulated significantly by all-trans-retinoic acid (ATRA). SPLUNC1 and retinoic acid receptor expression were induced significantly by ATRA, and removal of ATRA led to a progressive loss of SPLUNC1 and retinoic acid receptor expression. ATRA inhibited proliferation and induced the differentiation of NPC cells. Interestingly, over-expression of SPLUNC1 sensitized NPC cells to ATRA, whereas knockdown of SPLUNC1 in HNE1 cells increased cell viability. Under SPLUNC1 knockdown conditions, differentiation was reversed by ATRA treatment. We concluded that SPLUNC1 could potentially predict prognosis for NPC patients and play an important role in ATRA-induced growth inhibition and differentiation in NPC cells. PMID:25161098

  6. All-Trans Retinoic Acid-Induced Deficiency of the Wnt/β-Catenin Pathway Enhances Hepatic Carcinoma Stem Cell Differentiation.

    PubMed

    Zhu, Xinfeng; Wang, Wenxue; Zhang, Xia; Bai, Jianhua; Chen, Gang; Li, Li; Li, Meizhang

    2015-01-01

    Retinoic acid (RA) is an important biological signal that directly differentiates cells during embryonic development and tumorigenesis. However, the molecular mechanism of RA-mediated differentiation in hepatic cancer stem cells (hCSCs) is not well understood. In this study, we found that mRNA expressions of RA-biosynthesis-related dehydrogenases were highly expressed in hepatocellular carcinoma. All-trans retinoic acid (ATRA) differentiated hCSCs through inhibiting the function of β-catenin in vitro. ATRA also inhibited the function of PI3K-AKT and enhanced GSK-3β-dependent degradation of phosphorylated β-catenin. Furthermore, ATRA and β-catenin silencing both increased hCSC sensitivity to docetaxel treatment. Our results suggest that targeting β-catenin will provide extra benefits for ATRA-mediated treatment of hepatic cancer patients. PMID:26571119

  7. All-Trans Retinoic Acid-Induced Deficiency of the Wnt/β-Catenin Pathway Enhances Hepatic Carcinoma Stem Cell Differentiation

    PubMed Central

    Zhang, Xia; Bai, Jianhua; Chen, Gang; Li, Li; Li, Meizhang

    2015-01-01

    Retinoic acid (RA) is an important biological signal that directly differentiates cells during embryonic development and tumorigenesis. However, the molecular mechanism of RA-mediated differentiation in hepatic cancer stem cells (hCSCs) is not well understood. In this study, we found that mRNA expressions of RA-biosynthesis-related dehydrogenases were highly expressed in hepatocellular carcinoma. All-trans retinoic acid (ATRA) differentiated hCSCs through inhibiting the function of β-catenin in vitro. ATRA also inhibited the function of PI3K-AKT and enhanced GSK-3β-dependent degradation of phosphorylated β-catenin. Furthermore, ATRA and β-catenin silencing both increased hCSC sensitivity to docetaxel treatment. Our results suggest that targeting β-catenin will provide extra benefits for ATRA-mediated treatment of hepatic cancer patients. PMID:26571119

  8. Activation of protein phosphatase 2A is responsible for increased content and inactivation of respiratory chain complex i induced by all-trans retinoic acid in human keratinocytes.

    PubMed

    Papa, F; Sardaro, N; Lippolis, R; Panelli, D; Scacco, S

    2016-01-01

    This study presents the effect of all-trans retinoic acid (ATRA) on cell growth and respiratory chain complex I in human keratinocyte cultures. Keratinocyte treatment results in increased level of GRIM-19 and other subunits of complex I, in particular of their carbonylated forms, associated with inhibition of its enzymatic activity. The results show that in keratinocytes ATRA-promoted phosphatase activity controls the proteostasis and activity of complex I. PMID:27358125

  9. PALATAL EXPRESSION OF TGFB ISOFORMS IN NORMAL AND RETINOIC ACID-TREATED EMBRYOS

    EPA Science Inventory

    Retinoic Acid (RA) is know to induce cleft palate in all mammalian species tested. he aetiology of RA-induced cleft palate has been extensively investigated in C57B16 mouse embryos by one of us 1. e have recently shown distinct site- and stage-specific expression pattern of the R...

  10. Flusilazole induces spatio-temporal expression patterns of retinoic acid-, differentiation- and sterol biosynthesis-related genes in the rat Whole Embryo Culture.

    PubMed

    Dimopoulou, Myrto; Verhoef, Aart; van Ravenzwaay, Bennard; Rietjens, Ivonne M C M; Piersma, Aldert H

    2016-09-01

    Embryotoxic responses are critically dependent on the timing of exposure during embryo development. Here, we examined the time- dependent developmental effects in rat embryos exposed to flusilazole (FLU), and their link to retinoic acid (RA) mediated pathways. To this end, we assessed the effects of 4h exposure of rat embryos in vitro to 300μM FLU during four developmental time windows (0-4, 4-8, 24-28 and 44-48h), evaluating morphological parameters, expression and localization of five genes directly or indirectly linked with the RA pathway. These were RA- (Cyp26a1 and Dhrs3), differentiation- (Gbx2 and Cdx1) and sterol biosynthesis- (Cyp51) related genes. Extended exposure for 48h to 300μM FLU resulted in morphological changes, typical for triazoles and RA, while the 4h exposure times did not. Time dependent significant upregulation of the five selected genes was observed. These results corroborate that the embryotoxic responses to FLU are correlated with the regulation of the RA pathway. Thus, these gene expression markers can be considered early biomarkers of FLU-induced potential developmental toxicity later in the development. PMID:27094377

  11. Signalling Through Retinoic Acid Receptors is Required for Reprogramming of Both Mouse Embryonic Fibroblast Cells and Epiblast Stem Cells to Induced Pluripotent Stem Cells

    PubMed Central

    Yang, Jian; Wang, Wei; Ooi, Jolene; Campos, Lia S.

    2015-01-01

    Abstract We previously demonstrated that coexpressing retinoic acid (RA) receptor gamma and liver receptor homolog‐1 (LRH1 or NR5A2) with OCT4, MYC, KLF4, and SOX2 (4F) rapidly reprograms mouse embryonic fibroblast cells (MEFs) into induced pluripotent stem cells (iPSCs). Here, we further explore the role of RA in reprogramming and report that the six factors (6F) efficiently and directly reprogram MEFs into integration‐free iPSCs in defined medium (N2B27) in the absence of feeder cells. Through genetic and chemical approaches, we find that RA signalling is essential, in a highly dose‐sensitive manner, for MEF reprogramming. The removal of exogenous RA from N2B27, the inhibition of endogenous RA synthesis or the expression of a dominant‐negative form of RARA severely impedes reprogramming. By contrast, supplementing N2B27 with various retinoids substantially boosts reprogramming. In addition, when coexpressed with LRH1, RA receptors (RARs) can promote reprogramming in the absence of both exogenous and endogenously synthesized RA. Remarkably, the reprogramming of epiblast stem cells into embryonic stem cell‐like cells also requires low levels of RA, which can modulate Wnt signalling through physical interactions of RARs with β‐catenin. These results highlight the important functions of RA signalling in reprogramming somatic cells and primed stem cells to naïve pluripotency. Stem Cells 2015;33:1390–1404 PMID:25546009

  12. Retinoid metabolism and all-trans retinoic acid-induced growth inhibition in head and neck squamous cell carcinoma cell lines.

    PubMed Central

    Braakhuis, B. J.; Klaassen, I.; van der Leede, B. M.; Cloos, J.; Brakenhoff, R. H.; Copper, M. P.; Teerlink, T.; Hendriks, H. F.; van der Saag, P. T.; Snow, G. B.

    1997-01-01

    Retinoids can reverse potentially premalignant lesions and prevent second primary tumours in patients with head and neck squamous cell carcinoma (HNSCC). Furthermore, it has been reported that acquired resistance to all-trans retinoic acid (RA) in leukaemia is associated with decreased plasma peak levels, probably the result of enhanced retinoid metabolism. The aim of this study was to investigate the metabolism of retinoids and relate this to growth inhibition in HNSCC. Three HNSCC cell lines were selected on the basis of a large variation in the all-trans RA-induced growth inhibition. Cells were exposed to 9.5 nM (radioactive) for 4 and 24 h, and to 1 and 10 microM (nonradioactive) all-trans RA for 4, 24, 48 and 72 h, and medium and cells were analysed for retinoid metabolites. At all concentrations studied, the amount of growth inhibition was proportional to the extent at which all-trans-, 13- and 9-cis RA disappeared from the medium as well as from the cells. This turnover process coincided with the formation of a group of as yet unidentified polar retinoid metabolites. The level of mRNA of cellular RA-binding protein II (CRABP-II), involved in retinoid homeostasis, was inversely proportional to growth inhibition. These findings indicate that for HNSCC retinoid metabolism may be associated with growth inhibition. Images Figure 6 PMID:9231918

  13. microRNA-34a-Upregulated Retinoic Acid-Inducible Gene-I Promotes Apoptosis and Delays Cell Cycle Transition in Cervical Cancer Cells.

    PubMed

    Wang, Jing-Hua; Zhang, Le; Ma, Yu-Wei; Xiao, Jing; Zhang, Yi; Liu, Min; Tang, Hua

    2016-06-01

    The function of retinoic acid-inducible gene-I (RIG-I) in viral replication is well documented, but its function in carcinogenesis and malignancies as well as relationship with microRNAs (miRNAs) remain poorly understood. miR-34a is an antioncogene in multiple tumors. In our study, RIG-I and miR-34a suppressed cell growth, proliferation, migration, and invasion in cervical cancer cells in vitro. miR-34a was validated as a new regulator of RIG-I by binding to its 3' untranslated region and upregulating its expression level. Furthermore, we revealed that RIG-I and miR-34a enhanced apoptosis, delayed the G1/S/G2 transition of the cell cycle, and inhibited the epithelial-mesenchymal transition process to modulate malignancies in cervical cancer cells. Phenotypic rescue experiments indicated that RIG-I mediates the effects of miR-34a in HeLa and C33A cells. These findings provide new insights into the mechanisms that underlie carcinogenesis and may provide new biomarkers for the diagnosis and therapy of cervical cancer. PMID:26910120

  14. Retinoic acid specifically downregulates Fgf4 and inhibits posterior cell proliferation in the developing mouse autopod

    PubMed Central

    HAYES, CHRISTOPHER; MORRISS-KAY, GILLIAN M.

    2001-01-01

    Retinoic acid, when administered to pregnant mice on d 11.0 of gestation, causes limb skeletal abnormalities consisting of reduced digital number, shortening of the long bones and delayed ossification. We show here that these effects are correlated with a decrease in cell proliferation within 5 h of retinoic acid administration, specifically in the posterior half of the distal limb bud mesenchyme, from which the distal skeletal elements are generated. There is a specific downregulation of Fgf4, a gene known to be involved in limb bud outgrowth and expressed only in the posterior part of the apical ectodermal ridge; Fgf8, which is expressed throughout the apical ectodermal ridge, is unaffected. The reduction in Fgf4 expression is not accompanied by downregulation of Shh, nor of its receptor and downstream target gene Ptc, suggesting that the skeletal reduction defects induced by retinoic acid are mediated specifically by FGF4-induced skeletogenic mesenchymal cell proliferation. PMID:11430695

  15. Ethanol Effects On Physiological Retinoic Acid Levels

    PubMed Central

    Napoli, Joseph L.

    2011-01-01

    Summary All-trans-retinoic acid (atRA) serves essential functions during embryogenesis and throughout post-natal vertebrate life. Insufficient or excess atRA causes teratogenic and/or toxic effects in the developing embryo: interference with atRA biosynthesis or signaling likely underlies some forms of cancer. Many symptoms of vitamin A (atRA precursor) deficiency and/or toxicity overlap with those of another pleiotropic agent—ethanol. These overlapping symptoms have prompted research to understand whether interference with atRA biosynthesis and/or action may explain (in part) pathology associated with excess ethanol consumption. Ethanol affects many aspects of retinoid metabolism and mechanisms of action site-specifically, but no robust data support inhibition of vitamin A metabolism, resulting in decreased atRA in vivo during normal vitamin A nutriture. Actually, ethanol either has no effect on or increases atRA at select sites. Despite this realization, insight into whether interactions between ethanol and retinoids represent cause vs. effect requires additional research. PMID:21766417

  16. Altered retinoic acid signalling underpins dentition evolution.

    PubMed

    Gibert, Yann; Samarut, Eric; Pasco-Viel, Emmanuel; Bernard, Laure; Borday-Birraux, Véronique; Sadier, Alexa; Labbé, Catherine; Viriot, Laurent; Laudet, Vincent

    2015-03-01

    Small variations in signalling pathways have been linked to phenotypic diversity and speciation. In vertebrates, teeth represent a reservoir of adaptive morphological structures that are prone to evolutionary change. Cyprinid fish display an impressive diversity in tooth number, but the signals that generate such diversity are unknown. Here, we show that retinoic acid (RA) availability influences tooth number size in Cyprinids. Heterozygous adult zebrafish heterozygous for the cyp26b1 mutant that encodes an enzyme able to degrade RA possess an extra tooth in the ventral row. Expression analysis of pharyngeal mesenchyme markers such as dlx2a and lhx6 shows lateral, anterior and dorsal expansion of these markers in RA-treated embryos, whereas the expression of the dental epithelium markers dlx2b and dlx3b is unchanged. Our analysis suggests that changes in RA signalling play an important role in the diversification of teeth in Cyprinids. Our work illustrates that through subtle changes in the expression of rate-limiting enzymes, the RA pathway is an active player of tooth evolution in fish. PMID:25652838

  17. Altered retinoic acid signalling underpins dentition evolution

    PubMed Central

    Gibert, Yann; Samarut, Eric; Pasco-Viel, Emmanuel; Bernard, Laure; Borday-Birraux, Véronique; Sadier, Alexa; Labbé, Catherine; Viriot, Laurent; Laudet, Vincent

    2015-01-01

    Small variations in signalling pathways have been linked to phenotypic diversity and speciation. In vertebrates, teeth represent a reservoir of adaptive morphological structures that are prone to evolutionary change. Cyprinid fish display an impressive diversity in tooth number, but the signals that generate such diversity are unknown. Here, we show that retinoic acid (RA) availability influences tooth number size in Cyprinids. Heterozygous adult zebrafish heterozygous for the cyp26b1 mutant that encodes an enzyme able to degrade RA possess an extra tooth in the ventral row. Expression analysis of pharyngeal mesenchyme markers such as dlx2a and lhx6 shows lateral, anterior and dorsal expansion of these markers in RA-treated embryos, whereas the expression of the dental epithelium markers dlx2b and dlx3b is unchanged. Our analysis suggests that changes in RA signalling play an important role in the diversification of teeth in Cyprinids. Our work illustrates that through subtle changes in the expression of rate-limiting enzymes, the RA pathway is an active player of tooth evolution in fish. PMID:25652838

  18. Stress-induced NF-κB activation differentiates promyelocytic leukemia cells to macrophages in response to all-trans-retinoic acid.

    PubMed

    Imran, Muhammad; Park, Joon Seong; Lim, In Kyoung

    2015-03-01

    All-trans-retinoic acid (ATRA) has been known as a choice of treatment for inducing differentiation of promyelocytic leukemia cells to granulocytes. NF-κB plays a crucial role in inflammation and immunity and its activation is an important event for macrophage differentiation both in vivo and in vitro. We report here that NF-κB activation is critical for determining ATRA-induced lineage specific differentiation of myeloid leukemia cells. Our data revealed that ATRA treatment to HL-60 cells enhanced IκBα degradation and NF-κB nuclear translocation and the activated NF-κB potentiated the ability of ATRA for differentiation and switched differentiation to macrophages instead of granulocytes. Serum withdrawal and LPS treatment dampened IκBα expression via MAPK activation and reactive oxygen species generation leading to NF-κB nuclear translocation and ATRA treatment further corroborated these effects in myeloid leukemia cells. Activated NF-κB enhanced the degree of ATRA-induced differentiation of HL-60 cells to macrophages, rather than granulocytes, as assessed by morphologic examination and expressions of differentiation markers such as CD11b, CD38, CD68, MMP9 and Btg2. Employing LLnL or dominant negative IκBα attenuated NF-κB associated enhanced cell maturation and differentiation switch thus suggesting NF-κB as one of the factors that determines ATRA induced lineage specificity of myeloid leukemia cells. Furthermore, MAPK activation was observed to be central both for the differentiation of promyelocytic cells to macrophages or granulocytes regulating NF-κB or C/EBPα expressions, respectively; however, MAPK-mediated signals are modulated under various conditions affecting lineage specificity. In summary, our present data demonstrate that activation of NF-κB directly affects differentiation program of promyelocytes to macrophages, rather than granulocyte, in response to ATRA treatment. PMID:25435432

  19. Visible Absorption Properties of Retinoic Acid Controlled on Hydrogenated Amorphous Silicon Thin Film

    NASA Astrophysics Data System (ADS)

    Tsujiuchi, Yutaka; Masumoto, Hiroshi; Goto, Takashi

    2008-02-01

    Langmuir-Blodgett (LB) films of retinoic acid and LB films of retinoic acid mixed with a peptide that contains an alanine-lysine-valine (AKV) amino acid sequence deposited on a hydrogenated amorphous silicon (a-Si:H) film prepared by electron cyclotron resonance (ECR) plasma sputtering were fabricated, and their light absorption spectrums were compared. A specific visible light absorption at approximately 500 nm occurred in a film that had a film thickness of more than 80 nm and a hydrogen concentration of more than 20% in the sputtering process gas. Mixing the AKV sequence peptide with retinoic acid caused a 6 nm blueshift, from 363 to 357 nm, of the absorption maximum of the composite LB film on a SiO2 substrate. Using the same peptide, a large 30 nm blueshift, from 500 to 470 nm, was induced in the composite LB film on the a-Si:H film.

  20. Comparative Analysis of Protocols to Induce Human CD4+Foxp3+ Regulatory T Cells by Combinations of IL-2, TGF-beta, Retinoic Acid, Rapamycin and Butyrate.

    PubMed

    Schmidt, Angelika; Eriksson, Matilda; Shang, Ming-Mei; Weyd, Heiko; Tegnér, Jesper

    2016-01-01

    Regulatory T cells (Tregs) suppress other immune cells and are critical mediators of peripheral tolerance. Therapeutic manipulation of Tregs is subject to numerous clinical investigations including trials for adoptive Treg transfer. Since the number of naturally occurring Tregs (nTregs) is minute, it is highly desirable to develop a complementary approach of inducing Tregs (iTregs) from naïve T cells. Mouse studies exemplify the importance of peripherally induced Tregs as well as the applicability of iTreg transfer in different disease models. Yet, procedures to generate iTregs are currently controversial, particularly for human cells. Here we therefore comprehensively compare different established and define novel protocols of human iTreg generation using TGF-β in combination with other compounds. We found that human iTregs expressed several Treg signature molecules, such as Foxp3, CTLA-4 and EOS, while exhibiting low expression of the cytokines Interferon-γ, IL-10 and IL-17. Importantly, we identified a novel combination of TGF-β, retinoic acid and rapamycin as a robust protocol to induce human iTregs with superior suppressive activity in vitro compared to currently established induction protocols. However, iTregs generated by these protocols did not stably retain Foxp3 expression and did not suppress in vivo in a humanized graft-versus-host-disease mouse model, highlighting the need for further research to attain stable, suppressive iTregs. These results advance our understanding of the conditions enabling human iTreg generation and may have important implications for the development of adoptive transfer strategies targeting autoimmune and inflammatory diseases. PMID:26886923

  1. Comparative Analysis of Protocols to Induce Human CD4+Foxp3+ Regulatory T Cells by Combinations of IL-2, TGF-beta, Retinoic Acid, Rapamycin and Butyrate

    PubMed Central

    Schmidt, Angelika; Eriksson, Matilda; Shang, Ming-Mei; Weyd, Heiko; Tegnér, Jesper

    2016-01-01

    Regulatory T cells (Tregs) suppress other immune cells and are critical mediators of peripheral tolerance. Therapeutic manipulation of Tregs is subject to numerous clinical investigations including trials for adoptive Treg transfer. Since the number of naturally occurring Tregs (nTregs) is minute, it is highly desirable to develop a complementary approach of inducing Tregs (iTregs) from naïve T cells. Mouse studies exemplify the importance of peripherally induced Tregs as well as the applicability of iTreg transfer in different disease models. Yet, procedures to generate iTregs are currently controversial, particularly for human cells. Here we therefore comprehensively compare different established and define novel protocols of human iTreg generation using TGF-β in combination with other compounds. We found that human iTregs expressed several Treg signature molecules, such as Foxp3, CTLA-4 and EOS, while exhibiting low expression of the cytokines Interferon-γ, IL-10 and IL-17. Importantly, we identified a novel combination of TGF-β, retinoic acid and rapamycin as a robust protocol to induce human iTregs with superior suppressive activity in vitro compared to currently established induction protocols. However, iTregs generated by these protocols did not stably retain Foxp3 expression and did not suppress in vivo in a humanized graft-versus-host-disease mouse model, highlighting the need for further research to attain stable, suppressive iTregs. These results advance our understanding of the conditions enabling human iTreg generation and may have important implications for the development of adoptive transfer strategies targeting autoimmune and inflammatory diseases. PMID:26886923

  2. Proteomic profiling of the stem cell response to retinoic acid and synthetic retinoid analogues: identification of major retinoid-inducible proteins.

    PubMed

    Maltman, Daniel J; Christie, Victoria B; Collings, Jonathan C; Barnard, Jonathan H; Fenyk, Stepan; Marder, Todd B; Whiting, Andrew; Przyborski, Stefan A

    2009-05-01

    The natural retinoid, all-trans retinoic acid (ATRA), is widely used to direct the in vitro differentiation of stem cells. However, substantial degradation and isomerisation of ATRA in response to UV-vis light has serious implications with regard to experimental reproducibility and standardisation. We present the novel application of proteomic biomarker profiling technology to stem cell lysates to rapidly compare the differentiation effects of ATRA with those of two stable synthetic retinoid analogues, EC19 and EC23, which have both been shown to induce differentiation in the embryonal carcinoma cell line TERA2.cl.SP12. MALDI-TOF MS (matrix-assisted laser desorption ionisation time-of-flight mass spectrometry) protein profiles support previous findings into the functional relationships between these compounds in the TERA2.cl.SP12 line. Subsequent analysis of protein peak data enabled the semi-quantitative comparison of individual retinoid-responsive proteins. We have used ion exchange chromatographic protein separation to enrich for retinoid-inducible proteins, thereby facilitating their identification from SDS-PAGE gels. The cellular retinoid-responsive proteins CRABP-I, CRABP-II, and CRBP-I were up-regulated in response to ATRA and EC23, indicating a bona fide retinoid pathway response to the synthetic compound. In addition, the actin filament regulatory protein profilin-1 and the microtubule regulator stathmin were also elevated following treatment with both ATRA and EC23. The up-regulation of profilin-1 and stathmin associated with retinoid-induced neural differentiation correlates with their known roles in cytoskeletal reorganisation during axonal development. Immunological analysis via western blotting confirmed the identification of CRABP-I, profilin-1 and stathmin, and supported their observed regulation in response to the retinoid treatments. PMID:19381361

  3. Retinoid X receptor and retinoic acid response in the marine sponge Suberites domuncula.

    PubMed

    Wiens, Matthias; Batel, Renato; Korzhev, Michael; Müller, Werner E G

    2003-09-01

    To date no nuclear receptors have been identified or cloned from the phylogenetically oldest metazoan phylum, the Porifera (sponges). We show that retinoic acid causes tissue regression in intact individuals of the demosponge Suberites domuncula and in primmorphs, special three-dimensional cell aggregates. Primmorphs were cultivated on a galectin/poly-L-lysine matrix in order to induce canal formation. In the presence of 1 or 50 micromol l(-1) retinoic acid these canals undergo regression, a process that is reversible. We also cloned the cDNA from S. domuncula encoding the retinoid X receptor (RXR), which displays the two motifs of nuclear hormone receptors, the ligand-binding and the DNA-binding domains, and performed phylogenetic analyses of this receptor. RXR expression undergoes strong upregulation in response to treatment with retinoic acid, whereas the expression of the sponge caspase is not increased. The gene encoding the LIM homeodomain protein was found to be strongly upregulated in response to retinoic acid treatment. These data indicate that the RXR and its ligand retinoic acid play a role in the control of morphogenetic events in sponges. PMID:12909707

  4. Matrine cooperates with all-trans retinoic acid on differentiation induction of all-trans retinoic acid-resistant acute promyelocytic leukemia cells (NB4-LR1): possible mechanisms.

    PubMed

    Wu, Dijiong; Shao, Keding; Sun, Jie; Zhu, Fuyun; Ye, Baodong; Liu, Tingting; Shen, Yiping; Huang, He; Zhou, Yuhong

    2014-03-01

    Retinoic acid resistance results in refractory disease, and recovery in acute promyelocytic leukemia remains a challenge in clinical practice, with no ideal chemotherapeutic drug currently available. Here we report on the effect of an active compound of Sophora flavescens called matrine (0.1 mmol/L) combined with all-trans retinoic acid (1 µmol/L) in alleviating retinoic acid resistance in acute promyelocytic leukemia-derived NB4-LR1 cells by differentiation induction, as can be seen by an induced morphology change, increased CD11b expression, and nitro blue tetrazolium reduction activity, and a decreased expression of the promyelocytic leukemia-retinoic acid receptor α fusion gene and protein product. We further explored the probable mechanism of how matrine promotes the recovery of differentiation ability in NB4-LR1 cells when exposed to all-trans retinoic acid. We observed that the combination of all-trans retinoic acid and matrine can increase the level of cyclic adenosine monophosphate and protein kinase A activity, reduce telomerase activity, and downregulate the protein expression of topoisomerase II beta in NB4-LR1 cells. The results of this study suggest the possible clinical utility of matrine in the treatment of retinoic acid-resistant acute promyelocytic leukemia. PMID:24619838

  5. Structural analysis of DNA interaction with retinol and retinoic acid.

    PubMed

    Mandeville, J S; N'soukpoé-Kossi, C N; Neault, J F; Tajmir-Riahi, H A

    2010-06-01

    Dietary constituents of fresh fruits and vegetables may play a relevant role in DNA adduct formation by inhibiting enzymatic activities. Studies have shown the important role of antioxidant vitamins A, C, and E in the protection against cancer and cardiovascular diseases. The antioxidant activity of vitamin A and beta-carotene may consist of scavenging oxygen radicals and preventing DNA damage. This study was designed to examine the interaction of calf-thymus DNA with retinol and retinoic acid in aqueous solution at physiological conditions using a constant DNA concentration and various retinoid contents. Fourier transform infrared (FTIR), circular dichroism (CD), and fluorescence spectroscopic methods were used to determine retinoid binding mode, the binding constant, and the effects of retinol and retinoic acid complexation on DNA conformation and aggregation. Structural analysis showed that retinol and retinoic acid bind DNA via G-C and A-T base pairs and the backbone phosphate groups with overall binding constants of Kret = 3.0 (+/-0.50) x 10(3) (mol.L(-1))(-1) and Kretac = 1.0 (+/-0.20) x 10(4) (mol.L(-1))(-1). The number of bound retinoids per DNA were 0.84 for retinol and 1.3 for retinoic acid. Hydrophobic interactions were also observed at high retinol and retinoic acid contents. At a high retinoid concentration, major DNA aggregation occurred, while DNA remained in the B-family structure. PMID:20555389

  6. Photoaffinity labeling of retinoic acid-binding proteins.

    PubMed Central

    Bernstein, P S; Choi, S Y; Ho, Y C; Rando, R R

    1995-01-01

    Retinoid-binding proteins are essential mediators of vitamin A function in vertebrate organisms. They solubilize and stabilize retinoids, and they direct the intercellular and intracellular trafficking, transport, and metabolic function of vitamin A compounds in vision and in growth and development. Although many soluble retinoid-binding proteins and receptors have been purified and extensively characterized, relatively few membrane-associated enzymes and other proteins that interact with retinoids have been isolated and studied, due primarily to their inherent instabilities during purification. In an effort to identify and purify previously uncharacterized retinoid-binding proteins, it is shown that radioactively labeled all-trans-retinoic acid can be used as a photoaffinity labeling reagent to specifically tag two known retinoic acid-binding proteins, cellular retinoic acid-binding protein and albumin, in complex mixtures of cytosolic proteins. Additionally, a number of other soluble and membrane-associated proteins that bind all-trans-[11,12-3H]retinoic acid with high specificity are labeled utilizing the same photoaffinity techniques. Most of these labeled proteins have molecular weights that do not correspond to any known retinoid-binding proteins. Thus, photoaffinity labeling with all-trans-retinoic acid and related photoactivatable retinoids is a method that should prove extremely useful in the identification and purification of novel soluble and membrane-associated retinoid-binding proteins from ocular and nonocular tissues. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:7846032

  7. Cyanobacteria blooms produce teratogenic retinoic acids

    PubMed Central

    Wu, Xiaoqin; Jiang, Jieqiong; Wan, Yi; Giesy, John P.; Hu, Jianying

    2012-01-01

    Deformed amphibians have been observed in eutrophic habitats, and some clues point to the retinoic acids (RAs) or RA mimics. However, RAs are generally thought of as vertebrate-specific hormones, and there was no evidence that RAs exist in cyanobacteria or algae blooms. By analyzing RAs and their analogs 4-oxo-RAs in natural cyanobacteria blooms and cultures of cyanobacteria and algae, we showed that cyanobacteria blooms could produce RAs, which were powerful animal teratogens. Intracellular RAs and 4-oxo-RAs with concentrations between 0.4 and 4.2 × 102 ng/L were detected in all bloom materials, and extracellular concentrations measured in water from Taihu Lake, China, were as great as 2.0 × 10 ng/L, which might pose a risk to wildlife through chronic exposure. Further examination of 39 cyanobacteria and algae species revealed that 32 species could produce RAs and 4-oxo-RAs (1.6–1.4 × 103 ng/g dry weight), and the dominant cyanobacteria species in Taihu Lake, Microcystis flos-aquae and Microcystis aeruginosa, produced high amounts of RAs and 4-oxo-RAs with concentrations of 1.4 × 103 and 3.7 × 102 ng/g dry weight, respectively. Most genera of cyanobacteria that could produce RAs and 4-oxo-RAs, such as Microcystis, Anabaena, and Aphanizomenon, often occur dominantly in blooms. Production of RAs and 4-oxo-RAs by cyanobacteria was associated with species, origin location, and growth stage. These results represent a conclusive demonstration of endogenous production of RAs in freshwater cyanobacteria blooms. The observation of teratogenic RAs in cyanobacteria is evolutionarily and ecologically significant because RAs are vertebrate-specific hormones, and cyanobacteria form extensive and highly visible blooms in many aquatic ecosystems. PMID:22645328

  8. Regulatory CD8{sup +} T cells induced by exposure to all-trans retinoic acid and TGF-{beta} suppress autoimmune diabetes

    SciTech Connect

    Kishi, Minoru; Yasuda, Hisafumi; Abe, Yasuhisa; Sasaki, Hirotomo; Shimizu, Mami; Arai, Takashi; Okumachi, Yasuyo; Moriyama, Hiroaki; Hara, Kenta; Yokono, Koichi; Nagata, Masao

    2010-03-26

    Antigen-specific regulatory CD4{sup +} T cells have been described but there are few reports on regulatory CD8{sup +} T cells. We generated islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP)-specific regulatory CD8{sup +} T cells from 8.3-NOD transgenic mice. CD8{sup +} T cells from 8.3-NOD splenocytes were cultured with IGRP, splenic dendritic cells (SpDCs), TGF-{beta}, and all-trans retinoic acid (ATRA) for 5 days. CD8{sup +} T cells cultured with either IGRP alone or IGRP and SpDCs in the absence of TGF-{beta} and ATRA had low Foxp3{sup +} expression (1.7 {+-} 0.9% and 3.2 {+-} 4.5%, respectively). In contrast, CD8{sup +} T cells induced by exposure to IGRP, SpDCs, TGF-{beta}, and ATRA showed the highest expression of Foxp3{sup +} in IGRP-reactive CD8{sup +} T cells (36.1 {+-} 10.6%), which was approximately 40-fold increase compared with that before induction culture. CD25 expression on CD8{sup +} T cells cultured with IGRP, SpDCs, TGF-{beta}, and ATRA was only 7.42%, whereas CD103 expression was greater than 90%. These CD8{sup +} T cells suppressed the proliferation of diabetogenic CD8{sup +} T cells from 8.3-NOD splenocytes in vitro and completely prevented diabetes onset in NOD-scid mice in cotransfer experiments with diabetogenic splenocytes from NOD mice in vivo. Here we show that exposure to ATRA and TGF-{beta} induces CD8{sup +}Foxp3{sup +} T cells ex vivo, which suppress diabetogenic T cells in vitro and in vivo.

  9. Retinoic Acid Stimulates Regeneration of Mammalian Auditory Hair Cells

    NASA Astrophysics Data System (ADS)

    Lefebvre, Philippe P.; Malgrange, Brigitte; Staecker, Hinrich; Moonen, Gustave; van de Water, Thomas R.

    1993-04-01

    Sensorineural hearing loss resulting from the loss of auditory hair cells is thought to be irreversible in mammals. This study provides evidence that retinoic acid can stimulate the regeneration in vitro of mammalian auditory hair cells in ototoxic-poisoned organ of Corti explants in the rat. In contrast, treatment with retinoic acid does not stimulate the formation of extra hair cells in control cultures of Corti's organ. Retinoic acid-stimulated hair cell regeneration can be blocked by cytosine arabinoside, which suggests that a period of mitosis is required for the regeneration of auditory hair cells in this system. These results provide hope for a recovery of hearing function in mammals after auditory hair cell damage.

  10. Retinoic acid receptors: from molecular mechanisms to cancer therapy.

    PubMed

    di Masi, Alessandra; Leboffe, Loris; De Marinis, Elisabetta; Pagano, Francesca; Cicconi, Laura; Rochette-Egly, Cécile; Lo-Coco, Francesco; Ascenzi, Paolo; Nervi, Clara

    2015-02-01

    Retinoic acid (RA), the major bioactive metabolite of retinol or vitamin A, induces a spectrum of pleiotropic effects in cell growth and differentiation that are relevant for embryonic development and adult physiology. The RA activity is mediated primarily by members of the retinoic acid receptor (RAR) subfamily, namely RARα, RARβ and RARγ, which belong to the nuclear receptor (NR) superfamily of transcription factors. RARs form heterodimers with members of the retinoid X receptor (RXR) subfamily and act as ligand-regulated transcription factors through binding specific RA response elements (RAREs) located in target genes promoters. RARs also have non-genomic effects and activate kinase signaling pathways, which fine-tune the transcription of the RA target genes. The disruption of RA signaling pathways is thought to underlie the etiology of a number of hematological and non-hematological malignancies, including leukemias, skin cancer, head/neck cancer, lung cancer, breast cancer, ovarian cancer, prostate cancer, renal cell carcinoma, pancreatic cancer, liver cancer, glioblastoma and neuroblastoma. Of note, RA and its derivatives (retinoids) are employed as potential chemotherapeutic or chemopreventive agents because of their differentiation, anti-proliferative, pro-apoptotic, and anti-oxidant effects. In humans, retinoids reverse premalignant epithelial lesions, induce the differentiation of myeloid normal and leukemic cells, and prevent lung, liver, and breast cancer. Here, we provide an overview of the biochemical and molecular mechanisms that regulate the RA and retinoid signaling pathways. Moreover, mechanisms through which deregulation of RA signaling pathways ultimately impact on cancer are examined. Finally, the therapeutic effects of retinoids are reported. PMID:25543955

  11. Vitamin E supplementation does not prevent ethanol-reduced hepatic retinoic acid levels in rats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chronic, excessive ethanol intake can increase retinoic acid (RA) catabolism by inducing cytochrome P450 2E1 (CYP2E1). Vitamin E (VE) is an antioxidant implicated in CYP2E1 inhibition. In the current study, we hypothesized that VE supplementation inhibits CYP2E1 and decreases RA catabolism, thereby ...

  12. Retinoic acid influences neuronal migration from the ganglionic eminence to the cerebral cortex

    PubMed Central

    Crandall, James E.; Goodman, Timothy; McCarthy, Deirdre M.; Duester, Gregg; Bhide, Pradeep G.; Dräger, Ursula C.; McCaffery, Peter

    2013-01-01

    The ganglionic eminence contributes cells to several forebrain structures including the cerebral cortex, for which it provides GABAergic interneurons. Migration of neuronal precursors from the retinoic-acid rich embryonic ganglionic eminence to the cerebral cortex is known to be regulated by several factors, but retinoic acid has not been previously implicated. We found retinoic acid to potently inhibit cell migration in slice preparations of embryonic mouse forebrains, which was reversed by an antagonist of the dopamine-D2 receptor, whose gene is transcriptionally regulated by retinoic acid. Histonedeacetylase inhibitors, which amplify nuclear receptor-mediated transcription, potentiated the inhibitory effect of retinoic acid. Surprisingly, when retinoic acid signalling was completely blocked with a pan-retinoic acid receptor antagonist, this also decreased cell migration into the cortex, implying that a minimal level of endogenous retinoic acid is necessary for tangential migration. Given these opposing effects of retinoic acid in vitro, the in vivo contribution of retinoic acid to migration was tested by counting GABAergic interneurons in cortices of adult mice with experimental reductions in retinoic acid signalling: a range of perturbations resulted in significant reductions in the numerical density of some GABAergic interneuron subpopulations. These observations suggest functions of retinoic acid in interneuron diversity and organization of cortical excitatory–inhibitory balance. PMID:21895658

  13. Retinoic Acid Signaling Affects Cortical Synchrony During Sleep

    NASA Astrophysics Data System (ADS)

    Maret, Stéphanie; Franken, Paul; Dauvilliers, Yves; Ghyselinck, Norbert B.; Chambon, Pierre; Tafti, Mehdi

    2005-10-01

    Delta oscillations, characteristic of the electroencephalogram (EEG) of slow wave sleep, estimate sleep depth and need and are thought to be closely linked to the recovery function of sleep. The cellular mechanisms underlying the generation of delta waves at the cortical and thalamic levels are well documented, but the molecular regulatory mechanisms remain elusive. Here we demonstrate in the mouse that the gene encoding the retinoic acid receptor beta determines the contribution of delta oscillations to the sleep EEG. Thus, retinoic acid signaling, which is involved in the patterning of the brain and dopaminergic pathways, regulates cortical synchrony in the adult.

  14. Molecular Analysis of the Retinoic Acid Induced 1 Gene (RAI1) in Patients with Suspected Smith-Magenis Syndrome without the 17p11.2 Deletion

    PubMed Central

    Vilboux, Thierry; Ciccone, Carla; Blancato, Jan K.; Cox, Gerald F.; Deshpande, Charu; Introne, Wendy J.; Gahl, William A.; Smith, Ann C. M.; Huizing, Marjan

    2011-01-01

    Smith-Magenis syndrome (SMS) is a complex neurobehavioral disorder characterized by multiple congenital anomalies. The syndrome is primarily ascribed to a ∼3.7 Mb de novo deletion on chromosome 17p11.2. Haploinsufficiency of multiple genes likely underlies the complex clinical phenotype. RAI1 (Retinoic Acid Induced 1) is recognized as a major gene involved in the SMS phenotype. Extensive genetic and clinical analyses of 36 patients with SMS-like features, but without the 17p11.2 microdeletion, yielded 10 patients with RAI1 variants, including 4 with de novo deleterious mutations, and 6 with novel missense variants, 5 of which were familial. Haplotype analysis showed two major RAI1 haplotypes in our primarily Caucasian cohort; the novel RAI1 variants did not occur in a preferred haplotype. RNA analysis revealed that RAI1 mRNA expression was significantly decreased in cells of patients with the common 17p11.2 deletion, as well as in those with de novo RAI1 variants. Expression levels varied in patients with familial RAI1 variants and in non-17p11.2 deleted patients without identified RAI1 defects. No correlation between SNP haplotype and RAI1 expression was found. Two clinical features, ocular abnormalities and polyembolokoilomania (object insertion), were significantly correlated with decreased RAI1 expression. While not significantly correlated, the presence of hearing loss, seizures, hoarse voice, childhood onset of obesity and specific behavioral aspects and the absence of immunologic abnormalities and cardiovascular or renal structural anomalies, appeared to be specific for the de novo RAI1 subgroup. Recognition of the combination of these features will assist in referral for RAI1 analysis of patients with SMS-like features without detectable microdeletion of 17p11.2. Moreover, RAI1 expression emerged as a genetic target for development of therapeutic interventions for SMS. PMID:21857958

  15. All-trans-retinoic acid and CD38 ligation differentially regulate CD1d expression and α-galactosylceramide-induced immune responses.

    PubMed

    Chen, Qiuyan; Ross, A Catharine

    2015-01-01

    The MHC class-I like molecule CD1d presents glycolipid antigens and thereby activates invariant natural killer-T (NKT) cells. However, little is understood regarding the regulation of its expression. All-trans-retinoic acid (RA) and CD38, which is itself a target of RA, both independently regulate the differentiation of antigen presenting cells. In the current study, we treated human THP-1 cells and murine splenic cells with RA, with and without antibody-mediated ligation of cell-surface CD38. Whereas a physiological concentration (20 nM) of RA alone rapidly and markedly increased CD1d protein in THP-1 cells, there was a marked synergy between RA and ligation of CD38 with antibody to CD38. Moreover, RA and CD38 ligation differentially regulated CD1d protein distribution between the cell surface and intracellular compartments, as, whereas RA mainly increased intracellular CD1d protein, ligation of CD38 increased CD1d protein both at the cell surface and intracellularly. By confocal microscopy, CD1d was located close to the plasma membrane but only partially overlapped with LAMP1, a late endosomes/lysosomal marker. Furthermore, RA and/or CD38 ligation increased splenocyte proliferation and differentiation after treatment with the CD1 ligand α-galactosylceramide (αGalCer), evidenced by an increase in the number of splenic dendritic cells, NKT cells, and germinal center plasmacytes. RA also differentially regulated αGalCer-induced cytokine expression, increasing IL-4 and decreasing IFNγ production by total spleen cells and the NKT cell population. Our results indicate a previously unknown mechanism in which RA and CD38 differentially yet cooperatively regulate CD1d expression and antigen-presenting function, which could be important for the enhancement of immunity. PMID:25248321

  16. Hepatitis C Virus Frameshift/Alternate Reading Frame Protein Suppresses Interferon Responses Mediated by Pattern Recognition Receptor Retinoic-Acid-Inducible Gene-I

    PubMed Central

    Park, Seung Bum; Seronello, Scott; Mayer, Wasima; Ojcius, David M.

    2016-01-01

    Hepatitis C virus (HCV) actively evades host interferon (IFN) responses but the mechanisms of how it does so are not completely understood. In this study, we present evidence for an HCV factor that contributes to the suppression of retinoic-acid-inducible gene-I (RIG-I)-mediated IFN induction. Expression of frameshift/alternate reading frame protein (F/ARFP) from HCV -2/+1 frame in Huh7 hepatoma cells suppressed type I IFN responses stimulated by HCV RNA pathogen-associated molecular pattern (PAMP) and poly(IC). The suppression occurred independently of other HCV factors; and activation of interferon stimulated genes, TNFα, IFN-λ1, and IFN-λ2/3 was likewise suppressed by HCV F/ARFP. Point mutations in the full-length HCV sequence (JFH1 genotype 2a strain) were made to introduce premature termination codons in the -2/+1 reading frame coding for F/ARFP while preserving the original reading frame, which enhanced IFNα and IFNβ induction by HCV. The potentiation of IFN response by the F/ARFP mutations was diminished in Huh7.5 cells, which already have a defective RIG-I, and by decreasing RIG-I expression in Huh7 cells. Furthermore, adding F/ARFP back via trans-complementation suppressed IFN induction in the F/ARFP mutant. The F/ARFP mutants, on the other hand, were not resistant to exogenous IFNα. Finally, HCV-infected human liver samples showed significant F/ARFP antibody reactivity, compared to HCV-uninfected control livers. Therefore, HCV F/ARFP likely cooperates with other viral factors to suppress type I and III IFN induction occurring through the RIG-I signaling pathway. This study identifies a novel mechanism of pattern recognition receptor modulation by HCV and suggests a biological function of the HCV alternate reading frame in the modulation of host innate immunity. PMID:27404108

  17. Comparative analysis of transcriptional profiles of retinoic-acid-induced gene I-like receptors and interferons in seven tissues from ducks infected with avian Tembusu virus.

    PubMed

    Fu, Guanghua; Chen, Cuiteng; Huang, Yu; Cheng, Longfei; Fu, Qiuling; Wan, Chunhe; Shi, Shaohua; Chen, Hongmei; Liu, Wei

    2016-01-01

    Avian Tembusu virus (ATV), an emerging virus that mainly infects laying and breeding ducks in China, has caused severe economic loss in duck industry. However, there have been no reports about host innate immune responses during ATV infection and its correlation with clinical signs or pathology. To identify the roles of these immune factors in the innate host response to ATV infection, quantitative real-time PCR (qPCR) was used to analyze the transcriptional profiles on the genes encoding two retinoic-acid-induced gene I (RIG-I)-like receptors (RLRs) and two interferons (INF-α and INF-γ) in seven tissues of an ATV-infected shelduck. After infection with ATV, both RLR genes were significantly upregulated (P < 0.05) in all seven tissues. The peak expression levels of the two RLR genes were observed at 24 hours postinfection (hpi) and were higher in non-lymphoid tissues (liver, lung, kidney, and ovary) than in lymphoid tissues (thymus, spleen and bursa). Although the transcription levels of both IFN genes were also upregulated, they showed different time-dependent expression patterns compared with those of the RLR genes. In addition, the highest mRNA expression of the two IFN genes was observed in the ovary at 6 hpi. This observation suggests that the ovary is the primary target tissue in ATV infection and explains the clinical characteristics of the primary pathological changes in the ovaries of ATV-infected ducks. Our results, for the first time, elucidate the differential and coordinated expression profiles of two RLRs and two IFNs in an ATV-infected shelduck. PMID:26427380

  18. Targeted disruption of retinoic acid receptor alpha (RAR alpha) and RAR gamma results in receptor-specific alterations in retinoic acid-mediated differentiation and retinoic acid metabolism.

    PubMed Central

    Boylan, J F; Lufkin, T; Achkar, C C; Taneja, R; Chambon, P; Gudas, L J

    1995-01-01

    F9 embryonic teratocarcinoma stem cells differentiate into an epithelial cell type called extraembryonic endoderm when treated with retinoic acid (RA), a derivative of retinol (vitamin A). This differentiation is presumably mediated through the actions of retinoid receptors, the RARs and RXRs. To delineate the functions of each of the different retinoid receptors in this model system, we have generated F9 cell lines in which both copies of either the RAR alpha gene or the RAR gamma gene are disrupted by homologous recombination. The absence of RAR alpha is associated with a reduction in the RA-induced expression of both the CRABP-II and Hoxb-1 (formerly 2.9) genes. The absence of RAR gamma is associated with a loss of the RA-inducible expression of the Hoxa-1 (formerly Hox-1.6), Hoxa-3 (formerly Hox-1.5), laminin B1, collagen IV (alpha 1), GATA-4, and BMP-2 genes. Furthermore, the loss of RAR gamma is associated with a reduction in the metabolism of all-trans-RA to more polar derivatives, while the loss of RAR alpha is associated with an increase in metabolism of RA relative to wild-type F9 cells. Thus, each of these RARs exhibits some specificity with respect to the regulation of differentiation-specific gene expression. These results provide an explanation for the expression of multiple RAR types within one cell type and suggest that each RAR has specific functions. PMID:7823950

  19. The dual nature of retinoic acid in pemphigus and its therapeutic potential: Special focus on all-trans Retinoic Acid.

    PubMed

    Tavakolpour, Soheil; Daneshpazhooh, Maryam; Mahmoudi, Hamid Reza; Balighi, Kamran

    2016-07-01

    The efficient treatment of pemphigus with no certain side effect remained a controversial issue. Although there are various options for controlling disease severity, the majority of them may cause serious side effects. Retinoic acid (RA), an active metabolite converted from vitamin A, plays an active role in immune functions. Effects of RA, especially all-trans-Retinoic Acid (ATRA) on different types of cells involved in immune responses were analyzed in vitro and in vivo. RAs could affect the differentiation of T helper (Th) cells, B cells responses, stabilization of both natural regulatory T cells (nTregs) and regulatory B cells (Bregs) populations, and regulating the expression of critical genes in immune responses. The role of RA, based on major immune cells involved in pemphigus has not been addressed so far. In this study, we sought to determine the possible effects of RA, with a special focus on ATRA in pemphigus. All the evidences of ATRA effects on the immune system were collected and their association with the pemphigus was analyzed. According to the previous results, ATRA causes a decline in Th17 populations; increase in CD4+ induced regulatory T cells (iTregs), stabilization of nTregs, and promotion of suppressive B cells, which are critical in the improvement of pemphigus. Nevertheless, it also causes shifting of the Th1:Th2 balance toward Th2 cells, which is not favorable for pemphigus patients. In conclusion, ATRA acts via different ways in pemphigus. Due to increase in the suppressive function via iTregs, nTregs, and Bregs, it is suggested that patients with pemphigus may benefit from systemic ATRA therapy. To clarify this issue, further studies, such as clinical trials are needed. PMID:27156125

  20. Retinoic acid expands the evolutionarily reduced dentition of zebrafish.

    PubMed

    Seritrakul, Pawat; Samarut, Eric; Lama, Tenzing T S; Gibert, Yann; Laudet, Vincent; Jackman, William R

    2012-12-01

    Zebrafish lost anterior teeth during evolution but retain a posterior pharyngeal dentition that requires retinoic acid (RA) cell-cell signaling for its development. The purposes of this study were to test the sufficiency of RA to induce tooth development and to assess its role in evolution. We found that exposure of embryos to exogenous RA induces a dramatic anterior expansion of the number of pharyngeal teeth that later form and shifts anteriorly the expression patterns of genes normally expressed in the posterior tooth-forming region, such as pitx2 and dlx2b. After RA exposure, we also observed a correlation between cartilage malformations and ectopic tooth induction, as well as abnormal cranial neural crest marker gene expression. Additionally, we observed that the RA-induced zebrafish anterior teeth resemble in pattern and number the dentition of fish species that retain anterior pharyngeal teeth such as medaka but that medaka do not express the aldh1a2 RA-synthesizing enzyme in tooth-forming regions. We conclude that RA is sufficient to induce anterior ectopic tooth development in zebrafish where teeth were lost in evolution, potentially by altering neural crest cell development, and that changes in the location of RA synthesis correlate with evolutionary changes in vertebrate dentitions. PMID:22942074

  1. Dysregulated microRNA Clusters in Response to Retinoic Acid and CYP26B1 Inhibitor Induced Testicular Function in Dogs

    PubMed Central

    Kasimanickam, Vanmathy R.; Kasimanickam, Ramanathan K.; Dernell, William S.

    2014-01-01

    Spermatogenesis is a multistep synchronized process. Diploid spermatogonia differentiate into haploid spermatozoa following mitosis, meiosis and spermiogenesis. Division and differentiation of male germ cells is achieved through the sequential expression of several genes. Numerous mRNAs in the differentiating germ cells undergo post-transcriptional and translational regulation. MiRNAs are powerful negative regulators of mRNA transcription, stability, and translation and recognize their mRNA targets through base-pairing. Retinoic acid (RA) signaling is essential for spermatogenesis and testicular function. Testicular RA level is critical for RA signal transduction. This study investigated the miRNAs modulation in an RA- induced testicular environment following the administration of all-trans RA (2 µM) and CYP26B1- inhibitor (1 µM) compared to control. Eighty four canine mature miRNAs were analyzed and their expression signatures were distinguished using real-time PCR based array technology. Of the miRNAs analyzed, miRNA families such as miR-200 (cfa-miR-200a, cfa-miR-200b and cfa-miR-200c), Mirlet-7 (cfa-let-7a, cfa-let-7b, cfa-let-7c, cfa-let-7g and cfa-let-7f), miR-125 (cfa-miR-125a and cfa-miR-125b), miR-146 (cfa-miR-146a and cfa-miR-146b), miR-34 (cfa-miR-34a, cfa-miR-34b and cfa-miR-34c), miR-23 (cfa-miR-23a and cfa-miR-23b), cfa-miR-184, cfa-miR-214 and cfa-miR-141 were significantly up-regulated with testicular RA intervention via administration of CYP26B1 inhibitor and all-trans-RA and species of miRNA such as cfa-miR-19a, cfa-miR-29b, cfa-miR-29c, cfa-miR-101 and cfa-miR-137 were significantly down-regulated. This study explored information regarding chromosome distribution, human orthologous sequences and the interaction of target genes of miRNA families significantly distinguished in this study using prediction algorithms. This study importantly identified dysregulated miRNA species resulting from RA-induced spermatogenesis. The present contribution

  2. Three Conazoles Increase Hepatic Microsomal Retinoic Acid Metabolism and Decrease Mouse Hepatic Retinoic Acid Levels In Vivo

    EPA Science Inventory

    Conazoles are fungicides used in agriculture and as pharmaceuticals. In a previous toxicogenomic study of triazole-containing conazoles we found gene expression changes consistent with the alteration of the metabolism of all trans-retinoic acid (atRA), a vitamin A metabolite with...

  3. Chronic oral treatment with 13-cis-retinoic acid (isotretinoin) or all-trans-retinoic acid does not alter depression-like behaviors in rats.

    PubMed

    Ferguson, Sherry A; Cisneros, F Javier; Gough, B; Hanig, Joseph P; Berry, Kimberly J

    2005-10-01

    Oral treatment with the anti-acne drug Accutane (isotretinoin, 13-cis-retinoic acid) has been associated with suicide ideation and depression. Here, depression-like behaviors (i.e., behavioral despair and anhedonia) were quantified in adult Sprague-Dawley rats gavaged daily beginning at postnatal day (PND) 82 with 13-cis-RA (7.5 or 22.5 mg/kg) or all-trans-retinoic acid (10 or 15 mg/kg ). Tested at PND 130-131 in the Forced Swim Test, 7.5 mg/kg 13-cis-RA marginally decreased immobility and slightly increased climb/struggle durations whereas neither all-trans-retinoic acid group differed from controls. Voluntary saccharin solution (0.03%) intake at PND 102-104 and PND 151-153 was not different from controls in any treated group, although all RA-treated groups had lower intakes. Swim speed in a water maze at PND 180 was similar across groups, indicating no RA-induced differences in physical ability. Open field activity was mildly decreased at PND 91 in 7.5 mg/kg-treated males only, but it was within the control range at PND 119, 147, and 175. Thus, at serum levels similar to those in humans receiving the drug, chronic 13-cis-RA treatment did not severely affect depression-like behaviors in rats. These data do not substantiate the hypothesis of 13-cis-RA-induced depression. PMID:16033993

  4. Novel Retinoic Acid Receptor Alpha Agonists for Treatment of Kidney Disease

    PubMed Central

    Liu, Ruijie; Li, Zhengzhe; Chen, Yibang; Evans, Todd; Chuang, Peter; Das, Bhaskar; He, John Cijiang

    2011-01-01

    Development of pharmacologic agents that protect podocytes from injury is a critical strategy for the treatment of kidney glomerular diseases. Retinoic acid reduces proteinuria and glomerulosclerosis in multiple animal models of kidney diseases. However, clinical studies are limited because of significant side effects of retinoic acid. Animal studies suggest that all trans retinoic acid (ATRA) attenuates proteinuria by protecting podocytes from injury. The physiological actions of ATRA are mediated by binding to all three isoforms of the nuclear retinoic acid receptors (RARs): RARα, RARβ, and RARγ. We have previously shown that ATRA exerts its renal protective effects mainly through the agonism of RARα. Here, we designed and synthesized a novel boron-containing derivative of the RARα-specific agonist Am580. This new derivative, BD4, binds to RARα receptor specifically and is predicted to have less toxicity based on its structure. We confirmed experimentally that BD4 binds to RARα with a higher affinity and exhibits less cellular toxicity than Am580 and ATRA. BD4 induces the expression of podocyte differentiation markers (synaptopodin, nephrin, and WT-1) in cultured podocytes. Finally, we confirmed that BD4 reduces proteinuria and improves kidney injury in HIV-1 transgenic mice, a model for HIV-associated nephropathy (HIVAN). Mice treated with BD4 did not develop any obvious toxicity or side effect. Our data suggest that BD4 is a novel RARα agonist, which could be used as a potential therapy for patients with kidney disease such as HIVAN. PMID:22125642

  5. All-trans retinoic acid and rapamycin normalize Hutchinson Gilford progeria fibroblast phenotype

    PubMed Central

    Pellegrini, Camilla; Columbaro, Marta; Capanni, Cristina; D'Apice, Maria Rosaria; Cavallo, Carola; Murdocca, Michela; Lattanzi, Giovanna; Squarzoni, Stefano

    2015-01-01

    Hutchinson Gilford progeria syndrome is a fatal disorder characterized by accelerated aging, bone resorption and atherosclerosis, caused by a LMNA mutation which produces progerin, a mutant lamin A precursor. Progeria cells display progerin and prelamin A nuclear accumulation, altered histone methylation pattern, heterochromatin loss, increased DNA damage and cell cycle alterations. Since the LMNA promoter contains a retinoic acid responsive element, we investigated if all-trans retinoic acid administration could lower progerin levels in cultured fibroblasts. We also evaluated the effect of associating rapamycin, which induces autophagic degradation of progerin and prelamin A. We demonstrate that all-trans retinoic acid acts synergistically with low-dosage rapamycin reducing progerin and prelamin A, via transcriptional downregulation associated with protein degradation, and increasing the lamin A to progerin ratio. These effects rescue cell dynamics and cellular proliferation through recovery of DNA damage response factor PARP1 and chromatin-associated nuclear envelope proteins LAP2α and BAF. The combined all-trans retinoic acid-rapamycin treatment is dramatically efficient, highly reproducible, represents a promising new approach in Hutchinson-Gilford Progeria therapy and deserves investigation in ageing-associated disorders. PMID:26359359

  6. All-trans retinoic acid and rapamycin normalize Hutchinson Gilford progeria fibroblast phenotype.

    PubMed

    Pellegrini, Camilla; Columbaro, Marta; Capanni, Cristina; D'Apice, Maria Rosaria; Cavallo, Carola; Murdocca, Michela; Lattanzi, Giovanna; Squarzoni, Stefano

    2015-10-01

    Hutchinson Gilford progeria syndrome is a fatal disorder characterized by accelerated aging, bone resorption and atherosclerosis, caused by a LMNA mutation which produces progerin, a mutant lamin A precursor. Progeria cells display progerin and prelamin A nuclear accumulation, altered histone methylation pattern, heterochromatin loss, increased DNA damage and cell cycle alterations. Since the LMNA promoter contains a retinoic acid responsive element, we investigated if all-trans retinoic acid administration could lower progerin levels in cultured fibroblasts. We also evaluated the effect of associating rapamycin, which induces autophagic degradation of progerin and prelamin A. We demonstrate that all-trans retinoic acid acts synergistically with low-dosage rapamycin reducing progerin and prelamin A, via transcriptional downregulation associated with protein degradation, and increasing the lamin A to progerin ratio. These effects rescue cell dynamics and cellular proliferation through recovery of DNA damage response factor PARP1 and chromatin-associated nuclear envelope proteins LAP2α and BAF. The combined all-trans retinoic acid-rapamycin treatment is dramatically efficient, highly reproducible, represents a promising new approach in Hutchinson-Gilford Progeria therapy and deserves investigation in ageing-associated disorders. PMID:26359359

  7. A retinoic acid receptor-specific element controls the retinoic acid receptor-beta promoter.

    PubMed

    Hoffmann, B; Lehmann, J M; Zhang, X K; Hermann, T; Husmann, M; Graupner, G; Pfahl, M

    1990-11-01

    The morphogen retinoic acid (RA) regulates gene transcription by interacting with specific nuclear receptors that recognize DNA sequences near responsive promoters. While much has recently been learned about the nuclear receptor proteins, little is known about the genes that are directly regulated by RA and their cis-acting response elements recognized by these receptors. Here we have analyzed the RA receptor-beta (RAR beta) gene promoter that is controlled by RA. We find that a RA-responsive element (RARE) is located adjacent to the TATA box. The RARE shows a direct repeat symmetry which is essential for its function. While thyroid hormone-responsive elements can also function as RAR response elements, we show here that this RARE is activated by endogenous RARs and RAR beta, but cannot be regulated by thyroid hormone receptors and other known nuclear receptors. In addition, we find that RAR gamma is a poor activator of this RARE. However, the response element is bound with high affinity by both RAR beta and RAR gamma as well as by thyroid hormone receptors. Thus, interaction between specific response elements and receptors is insufficient for gene activation. PMID:2177841

  8. Role of Promyelocytic Leukemia (Pml) Sumolation in Nuclear Body Formation, 11s Proteasome Recruitment, and as2O3-Induced Pml or Pml/Retinoic Acid Receptor α Degradation

    PubMed Central

    Lallemand-Breitenbach, Valérie; Zhu, Jun; Puvion, Francine; Koken, Marcel; Honoré, Nicole; Doubeikovsky, Alexandre; Duprez, Estelle; Pandolfi, Pier Paolo; Puvion, Edmond; Freemont, Paul; de Thé, Hugues

    2001-01-01

    Promyelocytic leukemia (PML) is the organizer of nuclear matrix domains, PML nuclear bodies (NBs), with a proposed role in apoptosis control. In acute promyelocytic leukemia, PML/retinoic acid receptor (RAR) α expression disrupts NBs, but therapies such as retinoic acid or arsenic trioxide (As2O3) restore them. PML is conjugated by the ubiquitin-related peptide SUMO-1, a process enhanced by As2O3 and proposed to target PML to the nuclear matrix. We demonstrate that As2O3 triggers the proteasome-dependent degradation of PML and PML/RARα and that this process requires a specific sumolation site in PML, K160. PML sumolation is dispensable for its As2O3-induced matrix targeting and formation of primary nuclear aggregates, but is required for the formation of secondary shell-like NBs. Interestingly, only these mature NBs harbor 11S proteasome components, which are further recruited upon As2O3 exposure. Proteasome recruitment by sumolated PML only likely accounts for the failure of PML-K160R to be degraded. Therefore, studying the basis of As2O3-induced PML/RARα degradation we show that PML sumolation directly or indirectly promotes its catabolism, suggesting that mature NBs could be sites of intranuclear proteolysis and opening new insights into NB alterations found in viral infections or transformation. PMID:11413191

  9. Retinoic Acid-mediated Nuclear Receptor Activation and Hepatocyte Proliferation

    PubMed Central

    Bushue, Nathan; Wan, Yu-Jui Yvonne

    2016-01-01

    Due to their well-known differentiation and apoptosis-inducing abilities, retinoic acid (RA) and its analogs have strong anti-cancer efficacy in human cancers. However, in vivo RA is a liver mitogen. While speculation has persisted that RA-mediated signaling is likely involved in hepatocyte proliferation during liver regeneration, direct evidence is still required. Findings in support of this proposition include observations that a release of retinyl palmitate (the precursor of RA) occurs in liver stellate cells following liver injury. Nevertheless, the biological action of this released vitamin A is virtually unknown. More likely is that the released vitamin A is converted to RA, the biological form, and then bound to a specific receptor (retinoid x receptor; RXRα), which is most abundantly expressed in the liver. Considering the mitogenic effects of RA, the RA-activated RXRα would likely then influence hepatocyte proliferation and liver tissue repair. At present, the mechanism by which RA stimulates hepatocyte proliferation is largely unknown. This review summarizes the activation of nuclear receptors (peroxisome proliferator activated receptor-α, pregnane x receptor, constitutive androstane receptor, and farnesoid x receptor) in an RXRα dependent manner to induce hepatocyte proliferation, providing a link between RA and its proliferative role.

  10. Novel retinoic acid receptor ligands in Xenopus embryos.

    PubMed Central

    Blumberg, B; Bolado, J; Derguini, F; Craig, A G; Moreno, T A; Chakravarti, D; Heyman, R A; Buck, J; Evans, R M

    1996-01-01

    Retinoids are a large family of natural and synthetic compounds related to vitamin A that have pleiotropic effects on body physiology, reproduction, immunity, and embryonic development. The diverse activities of retinoids are primarily mediated by two families of nuclear retinoic acid receptors, the RARs and RXRs. Retinoic acids are thought to be the only natural ligands for these receptors and are widely assumed to be the active principle of vitamin A. However, during an unbiased, bioactivity-guided fractionation of Xenopus embryos, we were unable to detect significant levels of all-trans or 9-cis retinoic acids. Instead, we found that the major bioactive retinoid in the Xenopus egg and early embryo is 4-oxoretinaldehyde, which is capable of binding to and transactivating RARs. In addition to its inherent activity, 4-oxoretinaldehyde appears to be a metabolic precursor of two other RAR ligands, 4-oxoretinoic acid and 4-oxoretinol. The remarkable increase in activity of retinaldehyde and retinol as a consequence of 4-oxo derivatization suggests that this metabolic step could serve a critical regulatory function during embryogenesis. Images Fig. 1 Fig. 4 PMID:8643496

  11. All-trans retinoic acid combined with 5-Aza-2 Prime -deoxycitidine induces C/EBP{alpha} expression and growth inhibition in MLL-AF9-positive leukemic cells

    SciTech Connect

    Fujiki, Atsushi; Imamura, Toshihiko; Sakamoto, Kenichi; Kawashima, Sachiko; Yoshida, Hideki; Hirashima, Yoshifumi; Miyachi, Mitsuru; Yagyu, Shigeki; Nakatani, Takuya; Sugita, Kanji; Hosoi, Hajime

    2012-11-16

    Highlights: Black-Right-Pointing-Pointer We tested whether ATRA and 5-Aza affect AML cell differentiation and growth. Black-Right-Pointing-Pointer Cell differentiation and growth arrest were induced in MLL-AF9-expressing cells. Black-Right-Pointing-Pointer Increased expression of C/EBP{alpha}, C/EBP{epsilon}, and PU.1 were also observed. Black-Right-Pointing-Pointer MLL-AF4/AF5q31-expressing cells are less sensitive to ATRA and 5-Aza. Black-Right-Pointing-Pointer Different MLL fusion has distinct epigenetic properties related to RA pathway. -- Abstract: The present study tested whether all-trans retinoic acid (ATRA) and 5-Aza-2 Prime -deoxycitidine (5-Aza) affect AML cell differentiation and growth in vitro by acting on the CCAAT/enhancer binding protein {alpha} (C/EBP{alpha}) and c-Myc axis. After exposure to a combination of these agents, cell differentiation and growth arrest were significantly higher in human and murine MLL-AF9-expressing cells than in MLL-AF4/AF5q31-expressing cells, which were partly associated with increased expression of C/EBP{alpha}, C/EBP{epsilon}, and PU.1, and decreased expression of c-Myc. These findings indicate that MLL-AF9-expressing cells are more sensitive to ATRA and 5-Aza, indicating that different MLL fusion proteins possess different epigenetic properties associated with retinoic acid pathway inactivation.

  12. Retinoic acid inhibits histone methyltransferase Whsc1 during palatogenesis.

    PubMed

    Liu, Shiying; Higashihori, Norihisa; Yahiro, Kohei; Moriyama, Keiji

    2015-03-13

    Cleft lip with or without palate (CL/P) is a common congenital anomaly in humans and is thought to be caused by genetic and environmental factors. However, the epigenetic mechanisms underlying orofacial clefts are not fully understood. Here, we investigate how the overdose of retinoic acid (RA), which can induce cleft palate in mice and humans, regulates histone methyltransferase, Wolf-Hirschhorn syndrome candidate 1 (WHSC1) during palatal development in mice. We treated mouse embryonic fibroblasts (MEFs) with 1 μM all-trans RA and discovered that the global level of H3K36me3 was downregulated and that expression of the H3K36 methyltransferase gene, Whsc1, was reduced. The expression level of WHSC1 in embryonic palatal shelves was reduced during palatogenesis, following maternal administration of 100 mg/kg body weight of RA by gastric intubation. Furthermore, the expression of WHSC1 in palatal shelves was observed in epithelial and mesenchymal cells at all stages, suggesting an important role for palatal development. Our results suggest that the pathogenesis of cleft palate observed after excessive RA exposure is likely to be associated with a reduction in the histone methyltransferase, WHSC1. PMID:25677622

  13. Retinoic acid in alveolar development, maintenance and regeneration.

    PubMed Central

    Maden, Malcolm; Hind, Matthew

    2004-01-01

    Recent data suggest that exogenous retinoic acid (RA), the biologically active derivative of vitamin A, can induce alveolar regeneration in a rat model of experimental emphysema. Here, we describe a mouse model of disrupted alveolar development using dexamethasone administered postnatally. We show that the effects of dexamethasone are concentration dependent, dose dependent, long lasting and result in a severe loss of alveolar surface area. When RA is administered to these animals as adults, lung architecture and the surface area per unit of body weight are completely restored to normal. This remarkable effect may be because RA is required during normal alveolar development and administering RA re-awakens gene cascades used during development. We provide evidence that RA is required during alveologenesis in the mouse by showing that the levels of the retinoid binding proteins, the RA receptors and two RA synthesizing enzymes peak postnatally. Furthermore, an inhibitor of RA synthesis, disulphiram, disrupts alveologenesis. We also show that RA is required throughout life for the maintenance of lung alveoli because when rats are deprived of dietary retinol they lose alveoli and show the features of emphysema. Alveolar regeneration with RA may therefore be an important novel therapeutic approach to the treatment of respiratory diseases characterized by a reduced gas-exchanging surface area such as bronchopulmonary dysplasia and emphysema for which there are currently no treatments. PMID:15293808

  14. Calcineurin mediates homeostatic synaptic plasticity by regulating retinoic acid synthesis

    PubMed Central

    Arendt, Kristin L.; Zhang, Zhenjie; Ganesan, Subhashree; Hintze, Maik; Shin, Maggie M.; Tang, Yitai; Cho, Ahryon; Graef, Isabella A.; Chen, Lu

    2015-01-01

    Homeostatic synaptic plasticity is a form of non-Hebbian plasticity that maintains stability of the network and fidelity for information processing in response to prolonged perturbation of network and synaptic activity. Prolonged blockade of synaptic activity decreases resting Ca2+ levels in neurons, thereby inducing retinoic acid (RA) synthesis and RA-dependent homeostatic synaptic plasticity; however, the signal transduction pathway that links reduced Ca2+-levels to RA synthesis remains unknown. Here we identify the Ca2+-dependent protein phosphatase calcineurin (CaN) as a key regulator for RA synthesis and homeostatic synaptic plasticity. Prolonged inhibition of CaN activity promotes RA synthesis in neurons, and leads to increased excitatory and decreased inhibitory synaptic transmission. These effects of CaN inhibitors on synaptic transmission are blocked by pharmacological inhibitors of RA synthesis or acute genetic deletion of the RA receptor RARα. Thus, CaN, acting upstream of RA, plays a critical role in gating RA signaling pathway in response to synaptic activity. Moreover, activity blockade-induced homeostatic synaptic plasticity is absent in CaN knockout neurons, demonstrating the essential role of CaN in RA-dependent homeostatic synaptic plasticity. Interestingly, in GluA1 S831A and S845A knockin mice, CaN inhibitor- and RA-induced regulation of synaptic transmission is intact, suggesting that phosphorylation of GluA1 C-terminal serine residues S831 and S845 is not required for CaN inhibitor- or RA-induced homeostatic synaptic plasticity. Thus, our study uncovers an unforeseen role of CaN in postsynaptic signaling, and defines CaN as the Ca2+-sensing signaling molecule that mediates RA-dependent homeostatic synaptic plasticity. PMID:26443861

  15. Calcineurin mediates homeostatic synaptic plasticity by regulating retinoic acid synthesis.

    PubMed

    Arendt, Kristin L; Zhang, Zhenjie; Ganesan, Subhashree; Hintze, Maik; Shin, Maggie M; Tang, Yitai; Cho, Ahryon; Graef, Isabella A; Chen, Lu

    2015-10-20

    Homeostatic synaptic plasticity is a form of non-Hebbian plasticity that maintains stability of the network and fidelity for information processing in response to prolonged perturbation of network and synaptic activity. Prolonged blockade of synaptic activity decreases resting Ca(2+) levels in neurons, thereby inducing retinoic acid (RA) synthesis and RA-dependent homeostatic synaptic plasticity; however, the signal transduction pathway that links reduced Ca(2+)-levels to RA synthesis remains unknown. Here we identify the Ca(2+)-dependent protein phosphatase calcineurin (CaN) as a key regulator for RA synthesis and homeostatic synaptic plasticity. Prolonged inhibition of CaN activity promotes RA synthesis in neurons, and leads to increased excitatory and decreased inhibitory synaptic transmission. These effects of CaN inhibitors on synaptic transmission are blocked by pharmacological inhibitors of RA synthesis or acute genetic deletion of the RA receptor RARα. Thus, CaN, acting upstream of RA, plays a critical role in gating RA signaling pathway in response to synaptic activity. Moreover, activity blockade-induced homeostatic synaptic plasticity is absent in CaN knockout neurons, demonstrating the essential role of CaN in RA-dependent homeostatic synaptic plasticity. Interestingly, in GluA1 S831A and S845A knockin mice, CaN inhibitor- and RA-induced regulation of synaptic transmission is intact, suggesting that phosphorylation of GluA1 C-terminal serine residues S831 and S845 is not required for CaN inhibitor- or RA-induced homeostatic synaptic plasticity. Thus, our study uncovers an unforeseen role of CaN in postsynaptic signaling, and defines CaN as the Ca(2+)-sensing signaling molecule that mediates RA-dependent homeostatic synaptic plasticity. PMID:26443861

  16. Biological activity of all-trans retinol requires metabolic conversion to all-trans retinoic acid and is mediated through activation of nuclear retinoid receptors in human keratinocytes.

    PubMed

    Kurlandsky, S B; Xiao, J H; Duell, E A; Voorhees, J J; Fisher, G J

    1994-12-30

    The biological activity of all-trans retinol, in human keratinocytes, was investigated through metabolic and functional analyses that assessed the capacity for retinol uptake and metabolism and the mechanism of retinol-induced activation of gene transcription. Human keratinocytes converted all-trans retinol predominantly to retinyl esters, which accounted for 60 and 90% of cell-associated radiolabel after a 90-min pulse and a 48-h chase, respectively. Human keratinocytes also metabolized all-trans retinol to low levels of all-trans retinoic acid (11.47-131.3 ng/mg of protein) in a dose-dependent manner, between 0.3 and 10 microM added retinol. Small amounts of 13-cis retinoic acid (5.47-8.62 ng/mg of protein) were detected, but 9-cis retinoic acid was detected only when keratinocytes were incubated with radiolabeled retinol. There was no accumulation of the oxidized catabolic metabolites 4-hydroxy- or 4-oxoretinoic acid; however, 5,6-epoxy retinoic acid was detected at pharmacological levels (10 and 30 microM) of added retinol. Biological activity of retinol was assessed through analysis of two known retinoic acid-mediated responses: 1) reduction of type I epidermal transglutaminase and 2) activation of a retinoic acid receptor-dependent reporter gene, beta RARE3-tk-CAT. Both all-trans retinol and all-trans retinoic acid reduced type I epidermal transglutaminase in a dose-dependent manner; however, the ED50 for all-trans retinol (10 nM) was 10 times greater than for all-trans retinoic acid (1 nM). All-trans retinol also stimulated beta RARE3-tk-CAT reporter gene activity in a dose-dependent manner. Half-maximal induction was observed at 30 nM retinol, which was again 10-fold greater than observed with all-trans retinoic acid. Cotransfection of human keratinocytes with expression vectors for dominant negative mutant retinoic acid and retinoid X receptors reduced retinol-induced beta RARE3-tk-CAT reporter gene activation by 80%. Inhibition of conversion of all

  17. Retinoic acid‐induced glandular differentiation of the oesophagus

    PubMed Central

    Chang, Chih‐Long; Lao‐Sirieix, Pierre; Save, Vicki; De La Cueva Mendez, Guillermo; Laskey, Ron; Fitzgerald, Rebecca C

    2007-01-01

    Background Retinoic acid (RA) is a powerful differentiation agent. Barrett's oesophagus occurs when duodeno‐gastro‐oesophageal reflux causes squamous epithelium (SE) tissue to become columnar epithelium tissue by an unknown mechanism. The bile acid lithocholic acid (LCA) competes for the retinoid X receptor retinoid binding site. Hence, RA pathways may be implicated in Barrett's oesophagus. Methods RA activity in tissues and cell lines treated with all‐trans retinoic acid (ATRA) with or without LCA was assessed using a reporter. Expression of p21 was determined by real‐time PCR in Barrett's oesophagus cell lines with or without LCA. SE and Barrett's oesophagus biopsy specimens were exposed to 100 μM of ATRA or 20 mM of a RA inhibitor, citral, in organ culture for >72 h. Characteristics of treated specimens, compared with untreated controls, were analysed by immunohistochemical analysis (cytokeratins (CKs), vimentin) and RT‐PCR (CKs). Confocal microscopy assessed temporal changes in co‐localisation of CK8/18 and vimentin. Cell proliferation was assessed by bromo‐deoxyuridine incorporation and immunohistochemical analysis for Ki67 and p21. Results RA biosynthesis was increased in Barrett's oesophagus compared with SE (p<0.001). LCA and ATRA caused a synergistic increase in RA signalling as shown by increased p21 (p<0.01). Morphological and molecular analysis of SE exposed to ATRA showed columnar differentiation independent of proliferation. Metaplasia could be induced from the stromal compartment alone and vimentin expression co‐localised with CK8/18 at 24 h, which separated into CK8/18‐positive glands and vimentin‐positive stroma by 48 h. Citral‐treated Barrett's oesophagus led to phenotypic and immunohistochemical characteristics of SE, which was independent of proliferation. Conclusion RA activity is increased in Barrett's oesophagus and is induced by LCA. Under conditions of altered RA activity and an intact stroma, the

  18. Ethanol exposure affects gene expression in the embryonic organizer and reduces retinoic acid levels.

    PubMed

    Yelin, Ronit; Schyr, Racheli Ben-Haroush; Kot, Hadas; Zins, Sharon; Frumkin, Ayala; Pillemer, Graciela; Fainsod, Abraham

    2005-03-01

    Fetal Alcohol Spectrum Disorder (FASD) is a set of developmental malformations caused by alcohol consumption during pregnancy. Fetal Alcohol Syndrome (FAS), the strongest manifestation of FASD, results in short stature, microcephally and facial dysmorphogenesis including microphthalmia. Using Xenopus embryos as a model developmental system, we show that ethanol exposure recapitulates many aspects of FAS, including a shortened rostro-caudal axis, microcephally and microphthalmia. Temporal analysis revealed that Xenopus embryos are most sensitive to ethanol exposure between late blastula and early/mid gastrula stages. This window of sensitivity overlaps with the formation and early function of the embryonic organizer, Spemann's organizer. Molecular analysis revealed that ethanol exposure of embryos induces changes in the domains and levels of organizer-specific gene expression, identifying Spemann's organizer as an early target of ethanol. Ethanol also induces a defect in convergent extension movements that delays gastrulation movements and may affect the overall length. We show that mechanistically, ethanol is antagonistic to retinol (Vitamin A) and retinal conversion to retinoic acid, and that the organizer is active in retinoic acid signaling during early gastrulation. The model suggests that FASD is induced in part by an ethanol-dependent reduction in retinoic acid levels that are necessary for the normal function of Spemann's organizer. PMID:15708568

  19. Redox control of retinoic acid receptor activity: a novel mechanism for retinoic acid resistance in melanoma cells.

    PubMed

    Demary, K; Wong, L; Liou, J S; Faller, D V; Spanjaard, R A

    2001-06-01

    Retinoic acid (RA) slows growth and induces differentiation of tumor cells through activation of RA receptors (RARs). However, melanoma cell lines display highly variable responsiveness to RA, which is a poorly understood phenomenon. By using Northern and Western blot analyses, we show that RA-resistant A375 and RA-responsive S91 melanoma cells express comparable levels of major components of RAR-signaling pathways. However, A375 cells have substantially higher intracellular reactive oxygen species (ROS) levels than S91 cells. Lowering ROS levels in A375 cells through hypoxic culture conditions restores RAR-dependent trans-activity, which could be further enhanced by addition of the antioxidant N-acetyl-cysteine. Hypoxia also enhances RAR activity in the moderately RA-responsive C32 cells, which have intermediate ROS levels. Conversely, increasing oxidative stress in highly RA-responsive S91 and B16 cells, which have low ROS levels, by treatment with H(2)O(2) impairs RAR activity. Consistent with these observations, RA more potently inhibited the proliferation of hypoxic A375 cells than that of normoxic cells. Oxidative states diminish, whereas reducing conditions enhance, DNA binding of retinoid X receptor/RAR heterodimers in vitro, providing a molecular basis for the observed inverse correlation between RAR activity and ROS levels. The redox state of melanoma cells provides a novel, epigenetic control mechanism of RAR activity and RA resistance. PMID:11356710

  20. All-Trans Retinoic Acid Modulates ORMDL3 Expression via Transcriptional Regulation

    PubMed Central

    Zhuang, Li-Li; Huang, Bo-Xian; Feng, Jie; Zhu, Liang-Hua; Jin, Rui; Qiu, Ling-Zhi; Zhou, Guo-Ping

    2013-01-01

    All-trans retinoic acid (ATRA) is an active metabolite of Vitamin A, it shows protective effects on asthma, including maintains airway epithelial integrity, inhibits asthma effector cells differentiation, modulates immune response, et al. However, the promoting effect of ATRA on Th2 response has restricted the clinical application of ATRA in asthma treatment. ORMDL3 is a candidate gene of childhood onset asthma, and high-transcript of ORMDL3 is associated with the development of asthma. Here we show that ATRA increases ORMDL3 production in vitro via inducing PKA-dependent CREB phosphorylation which in turn binds to the CRE element in promoter region of ORMDL3 and initiates ORMDL3 transcription. This finding is in consistent with the previous reports that ATRA could regulate target genes without the presence of retinoic acid response element (RARE) in promoter region but through other signals such as PKA/CREB. Nevertheless, in the present study, the traditional signal pathway of ATRA, retinoic acid receptor (RAR) signal transduction pathway, indirectly modulated ORMDL3 expression. RAR-α agonist (Am-80) increased ORMDL3 production even though there was no RARE in ORMDL3 promoter, introns or 3′-downstream region. Besides, the signal of RAR might differ from that of ATRA since Am-80 failed to induce CREB activation. In conclusion, our data indicate that ATRA facilitates ORMDL3 production probable through PKA/CREB, and this may be a starting point for more detailed mechanism researches on ATRA and asthma. PMID:24204796

  1. All-trans retinoic acid modulates ORMDL3 expression via transcriptional regulation.

    PubMed

    Zhuang, Li-Li; Huang, Bo-Xian; Feng, Jie; Zhu, Liang-Hua; Jin, Rui; Qiu, Ling-Zhi; Zhou, Guo-Ping

    2013-01-01

    All-trans retinoic acid (ATRA) is an active metabolite of Vitamin A, it shows protective effects on asthma, including maintains airway epithelial integrity, inhibits asthma effector cells differentiation, modulates immune response, et al. However, the promoting effect of ATRA on Th2 response has restricted the clinical application of ATRA in asthma treatment. ORMDL3 is a candidate gene of childhood onset asthma, and high-transcript of ORMDL3 is associated with the development of asthma. Here we show that ATRA increases ORMDL3 production in vitro via inducing PKA-dependent CREB phosphorylation which in turn binds to the CRE element in promoter region of ORMDL3 and initiates ORMDL3 transcription. This finding is in consistent with the previous reports that ATRA could regulate target genes without the presence of retinoic acid response element (RARE) in promoter region but through other signals such as PKA/CREB. Nevertheless, in the present study, the traditional signal pathway of ATRA, retinoic acid receptor (RAR) signal transduction pathway, indirectly modulated ORMDL3 expression. RAR-α agonist (Am-80) increased ORMDL3 production even though there was no RARE in ORMDL3 promoter, introns or 3'-downstream region. Besides, the signal of RAR might differ from that of ATRA since Am-80 failed to induce CREB activation. In conclusion, our data indicate that ATRA facilitates ORMDL3 production probable through PKA/CREB, and this may be a starting point for more detailed mechanism researches on ATRA and asthma. PMID:24204796

  2. All-Trans Retinoic Acid Induces Proliferation, Survival, and Migration in A549 Lung Cancer Cells by Activating the ERK Signaling Pathway through a Transcription-Independent Mechanism

    PubMed Central

    Quintero Barceinas, Reyna Sara; García-Regalado, Alejandro; Aréchaga-Ocampo, Elena; Villegas-Sepúlveda, Nicolás; González-De la Rosa, Claudia Haydée

    2015-01-01

    All-trans retinoic acid (ATRA) has been used as an antineoplastic because of its ability to promote proliferation, inhibition, and differentiation, primarily in leukemia; however, in other types of cancer, such as lung cancer, treatment with ATRA is restricted because not all the patients experience the same results. The ERK signaling pathway is dysregulated in cancer cells, including lung cancer, and this dysregulation promotes proliferation and cell invasion. In this study, we demonstrate that treatment with ATRA can activate the ERK signaling pathway by a transcription-independent mechanism through a signaling cascade that involves RARα and PI3K, promoting growth, survival, and migration in lung cancer cells. Until now, this mechanism was unknown in lung cancer cells. The inhibition of the ERK signaling pathway restores the beneficial effects of ATRA, reduces proliferation, increases apoptosis, and blocks the cell migration process in lung cancer cells. In conclusion, our results suggest that the combination of ATRA with ERK inhibitor in clinical trials for lung cancer is warranted. PMID:26557664

  3. α-Mangostin, a Natural Agent, Enhances the Response of NRAS Mutant Melanoma to Retinoic Acid

    PubMed Central

    Xia, Yun; Chen, Jing; Gong, Chongwen; Chen, Hongxiang; Sun, Jiaming

    2016-01-01

    Background The identification and use of novel compounds alone or in combination hold promise for the fight against NRAS mutant melanoma. Material/Methods We screened a kinase-specific inhibitor library through combining it with α-Mangostin in NRAS mutant melanoma cell line, and verified the enhancing effect of α-Mangostin through inhibition of the tumorigenesis pathway. Results Within the kinase inhibitors, retinoic acid showed a significant synergistic effect with α-Mangostin. α-Mangostin also can reverse the drug resistance of retinoic acid in RARa siRNA-transduced sk-mel-2 cells. Colony assay, TUNEL staining, and the expressions of several apoptosis-related genes revealed that α-Mangostin enhanced the effect of retinoic acid-induced apoptosis. The combination treatment resulted in marked induction of ROS generation and inhibition of the AKT/S6 pathway. Conclusions These results indicate that the combination of these novel natural agents with retinoid acid may be clinically effective in NRAS mutant melanoma. PMID:27104669

  4. α-Mangostin, a Natural Agent, Enhances the Response of NRAS Mutant Melanoma to Retinoic Acid.

    PubMed

    Xia, Yun; Chen, Jing; Gong, Chongwen; Chen, Hongxiang; Sun, Jiaming

    2016-01-01

    BACKGROUND The identification and use of novel compounds alone or in combination hold promise for the fight against NRAS mutant melanoma. MATERIAL AND METHODS We screened a kinase-specific inhibitor library through combining it with α-Mangostin in NRAS mutant melanoma cell line, and verified the enhancing effect of α-Mangostin through inhibition of the tumorigenesis pathway. RESULTS Within the kinase inhibitors, retinoic acid showed a significant synergistic effect with α-Mangostin. α-Mangostin also can reverse the drug resistance of retinoic acid in RARa siRNA-transduced sk-mel-2 cells. Colony assay, TUNEL staining, and the expressions of several apoptosis-related genes revealed that a-Mangostin enhanced the effect of retinoic acid-induced apoptosis. The combination treatment resulted in marked induction of ROS generation and inhibition of the AKT/S6 pathway. CONCLUSIONS These results indicate that the combination of these novel natural agents with retinoid acid may be clinically effective in NRAS mutant melanoma. PMID:27104669

  5. T-box binding protein type two (TBX2) is an immediate early gene target in retinoic-acid-treated B16 murine melanoma cells.

    PubMed

    Boskovic, Goran; Niles, Richard M

    2004-05-01

    Retinoic acid induces growth arrest and differentiation in B16 mouse melanoma cells. Using gene arrays, we identified several early response genes whose expression is altered by retinoic acid. One of the genes, tbx2, is a member of T-box nuclear binding proteins that are important morphogens in developing embryos. Increased TBX2 mRNA is seen within 2 h after addition of retinoic acid to B16 cells. The effect of retinoic acid on gene expression is direct since it does not require any new protein synthesis. We identified a degenerate retinoic acid response element (RARE) between -186 and -163 in the promoter region of the tbx2 gene. A synthetic oligonucleotide spanning this region was able to drive increased expression of a luciferase reporter gene in response to retinoic acid; however, this induction was lost when a point mutation was introduced into the RARE. This oligonucleotide also specifically bound RAR in nuclear extracts from B16 cells. TBX2 expression and its induction by retinoic acid was also observed in normal human and nonmalignant mouse melanocytes. PMID:15093729

  6. Thyroid hormone activation of retinoic acid synthesis in hypothalamic tanycytes

    PubMed Central

    Stoney, Patrick N.; Helfer, Gisela; Rodrigues, Diana; Morgan, Peter J.

    2015-01-01

    Thyroid hormone (TH) is essential for adult brain function and its actions include several key roles in the hypothalamus. Although TH controls gene expression via specific TH receptors of the nuclear receptor class, surprisingly few genes have been demonstrated to be directly regulated by TH in the hypothalamus, or the adult brain as a whole. This study explored the rapid induction by TH of retinaldehyde dehydrogenase 1 (Raldh1), encoding a retinoic acid (RA)‐synthesizing enzyme, as a gene specifically expressed in hypothalamic tanycytes, cells that mediate a number of actions of TH in the hypothalamus. The resulting increase in RA may then regulate gene expression via the RA receptors, also of the nuclear receptor class. In vivo exposure of the rat to TH led to a significant and rapid increase in hypothalamic Raldh1 within 4 hours. That this may lead to an in vivo increase in RA is suggested by the later induction by TH of the RA‐responsive gene Cyp26b1. To explore the actions of RA in the hypothalamus as a potential mediator of TH control of gene regulation, an ex vivo hypothalamic rat slice culture method was developed in which the Raldh1‐expressing tanycytes were maintained. These slice cultures confirmed that TH did not act on genes regulating energy balance but could induce Raldh1. RA has the potential to upregulate expression of genes involved in growth and appetite, Ghrh and Agrp. This regulation is acutely sensitive to epigenetic changes, as has been shown for TH action in vivo. These results indicate that sequential triggering of two nuclear receptor signalling systems has the capability to mediate some of the functions of TH in the hypothalamus. GLIA 2016;64:425–439 PMID:26527258

  7. All-Trans-Retinoic-Acid Unmasking Hypercalcemia of Hyperparathyroidism.

    PubMed

    Yanamandra, Uday; Sahu, Kamal Kant; Khadwal, Alka; Prakash, Gaurav; Varma, Subhash Chander; Malhotra, Pankaj

    2016-06-01

    We present a patient of acute promyelocytic leukaemia managed with all-trans-retinoic-acid and arsenic trioxide who developed hypercalcemia with target organ damage. The patient also was simultaneously discovered to be symptomatic from hyperparathyroidism, which was unmasked after ATRA administration. Patient was successfully managed without any interruption of ATRA therapy and parathyroidectomy. We discuss the mechanisms of ATRA in causing hypercalcemia and its possible role in index case in unmasking hyperparathyroidism. Present case refutes Occam's razor and emphasise that known adverse effects shouldn't withhold clinicians from working up for other common causes for a given condition. PMID:27408352

  8. Conformational Analysis of Free and Bound Retinoic Acid

    PubMed Central

    Fu, Zheng; Li, Xue; Merz, Kenneth M.

    2012-01-01

    The conformational profiles of unbound all-trans and 9-cis retinoic acid (RA) have been determined using classical and quantum mechanical calculations. Sixty-six all-trans-RA (ATRA) and forty-eight 9-cis-RA energy minimum conformers were identified via HF/6-31G* geometry optimizations in vacuo. Their relative conformational energies were estimated utilizing the M06, M06-2x and MP2 methods combined with the 6-311+G(d,p), aug-cc-pVDZ and aug-cc-pVTZ basis sets, as well as complete basis set MP2 extrapolations using the latter two basis sets. Single-point energy calculations performed with the M06-2x density functional were found to yield similar results to MP2/CBS for the low-energy retinoic acid conformations. Not unexpectedly, the conformational propensities of retinoic acid were governed by the orientation and arrangement of the torsion angles associated with the polyene tail. We also used previously reported QM/MM X-ray refinement results on four ATRA-protein crystal structures plus one newly refined 9-cis-RA complex (PDB ID 1XDK) in order to investigate the conformational preferences of bound retinoic acid. In the re-refined RA conformers the conjugated double bonds are nearly coplanar, which is consistent with the global minimum identified by the Omega/QM method rather than the corresponding crystallographically determined conformations given in the PDB. Consequently, a 91.3% average reduction of the local strain energy in the gas phase, as well as 92.1% in PCM solvent, was observed using the QM/MM refined structures versus the PDB deposited RA conformations. These results thus demonstrate that our QM/MM X-ray refinement approach can significantly enhance the quality of X-ray crystal structures refined by conventional refinement protocols, thereby providing reliable drug-target structural information for use in structure-based drug discovery applications. PMID:22844234

  9. REACTIVITY PROFILE OF LIGANDS OF MAMMALIAN RETINOIC ACID RECEPTORS: A PRELIMINARY COREPA ANALYSIS

    EPA Science Inventory

    Retinoic acid and associated derivatives comprise a class of endogenous hormones that bind to and activate different families of retinoic acid receptors (RARs, RXRs), and control many aspects of vertebrate development. Identification of potential RAR and RXR ligands is of interes...

  10. Enhancement of fludarabine sensitivity by all-trans-retinoic acid in chronic lymphocytic leukemia cells

    PubMed Central

    Fernández-Calotti, Paula X.; Lopez-Guerra, Mónica; Colomer, Dolors; Pastor-Anglada, Marçal

    2012-01-01

    Background A subset of patients with fludarabine-resistant chronic lymphocytic leukemia has previously been shown to express elevated intracellular levels of the concentrative high-affinity fludarabine transporter hCNT3, without any detectable related activity. We have recently shown that all-trans-retinoic acid is capable of inducing hCNT3 trafficking to plasma membrane in the MEC1 cell line. We, therefore, evaluated the effect of all-trans-retinoic acid on hCNT3 in primary chronic lymphocytic leukemia cells as a suitable mechanism to improve fludarabine-based therapy of chronic lymphocytic leukemia. Design and Methods Cells from 23 chronic lymphocytic leukemia patients wild-type for P53 were analyzed for ex vivo sensitivity to fludarabine. hCNT3 activity in chronic lymphocytic leukemia cell samples was evaluated by measuring the uptake of [8-3H]-fludarabine. The amounts of transforming growth factor-β1 and hCNT3 messenger RNA were analyzed by real-time polymerase chain reaction. The effect of all-trans-retinoic acid on hCNT3 subcellular localization was analyzed by confocal microscopy and its effect on fludarabine-induced apoptosis was evaluated by flow cytometry analysis using annexin V staining. Results Chronic lymphocytic leukemia cases showing higher ex vivo basal sensitivity to fludarabine also had a greater basal hCNT3-associated fludarabine uptake capacity compared to the subset of patients showing ex vivo resistance to the drug. hCNT3 transporter activity in chronic lymphocytic leukemia cells from the latter patients was either negligible or absent. Treatment of the fludarabine-resistant subset of chronic lymphocytic leukemia cells with all-trans-retinoic acid induced increased fludarabine transport via hCNT3 which was associated with a significant increase in fludarabine sensitivity. Conclusions Improvement of ex vivo fludarabine sensitivity in chronic lymphocytic leukemia cells is associated with increased hCNT3 activity after all-trans-retinoic acid

  11. Effect of mitotic inducers and retinoic acid blocker on expression of pluripotent genes in ES cells derived from early stage in vitro-produced embryos in buffalo.

    PubMed

    Kumar, Ashok; Kumar, Kuldeep; Singh, Renu; Puri, Gopal; Ranjan, R; Yasotha, T; Singh, R K; Sarkar, M; Bag, Sadhan

    2012-12-01

    So far, it has been difficult to generate embryonic stem (ES) cell from early stage preimplantation embryos of buffalo. These ES cells will be more helpful for efficient embryo cloning and generation of body cells as they are more primitive than inner cell mass (ICM)-derived ES cells. The present study was conducted to find the effect of lipopolysaccharide (LPS), melatonin (N-acetyl-5-methoxytryptamine, a pineal gland product), and citral (3,7-dimethyl-2,6-octadienal and a retinoic acid synthesis blocker) on establishment of primary ES cell colonies, the comparative size of the ES cell colonies, and expression of pluripotent genes during extended period of culture in buffalo. Zona-free eight-cell stage in vitro fertilization (IVF) embryos were cultured in ES cell medium supplemented with none (media I as control), LPS (media II), citral melatonin (media III), or melatonin (media IV). The multiplication of blastomere leading to ES cell colony formation and expression of pluripotent genes were assessed up to day 20 of culture. The primary colony formation, the comparative size of the ES cell colonies, and expression of pluripotent genes in these colonies were better in the medium supplemented with melatonin in all days of culture. Within melatonin supplementation, the colony size was comparatively larger on day 8 and day 12 of culture. Further, with this supplementation, the Oct-4 and Nanog expression was comparatively higher on all days of culture. The results indicated that supplementation of melatonin helped in the formation of better primary ES cell colony as well as in the maintenance of pluripotency. The results also indicated that primary colonies developed on day 8 to day 12 of culture may be better for passaging them for establishment of ES cell line from early stage preimplantation IVF embryos of in buffalo. PMID:23093464

  12. Retinoic acid-induced differentiation of human neuroblastoma SH-SY5Y cells is associated with changes in the abundance of G proteins.

    PubMed

    Ammer, H; Schulz, R

    1994-04-01

    Western blot analysis, using subtype-specific anti-G protein antibodies, revealed the presence of the following G protein subunits in human neuroblastoma SH-SY5Y cells: Gs alpha, Gi alpha 1, Gi alpha 2, Go alpha, Gz alpha, and G beta. Differentiation of the cells by all-trans-retinoic acid (RA) treatment (10 mumol/L; 6 days) caused substantial alterations in the abundance of distinct G protein subunits. Concomitant with an enhanced expression of mu-opioid binding sites, the levels of the inhibitory G proteins Gi alpha 1 and Gi alpha 2 were found to be significantly increased. This coordinate up-regulation is accompanied by functional changes in mu-opioid receptor-stimulated low-Km GTPase, mu-receptor-mediated adenylate cyclase inhibition, and receptor-independent guanosine 5'-(beta gamma-imido)triphosphate [Gpp(NH)p; 10 nmol/L]-mediated attenuation of adenylate cyclase activity. In contrast, increased levels of inhibitory G proteins had no effect on muscarinic cholinergic receptor-mediated adenylate cyclase inhibition. With respect to stimulatory receptor systems, a reciprocal regulation was observed for prostaglandin E1 (PGE1) receptors and Gs alpha, the G protein subunit activating adenylate cyclase. RA treatment of SH-SY5Y cells increases both the number of PGE1 binding sites and PGE1-stimulated adenylate cyclase activity, but significantly reduced amounts of Gs alpha were found. This down-regulation is paralleled by a decrease in the stimulatory activity of Gs alpha as assessed in S49 cyc- reconstitution assays.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8133263

  13. Retinoic acid binding protein in normal and neopolastic rat prostate.

    PubMed

    Gesell, M S; Brandes, M J; Arnold, E A; Isaacs, J T; Ueda, H; Millan, J C; Brandes, D

    1982-01-01

    Sucrose density gradient analysis of cytosol from normal and neoplastic rat prostatic tissues exhibited a peak of (3H) retinoic acid binding in the 2S region, corresponding to the cytoplasmic retinoic acid binding protein (cRABP). In the Fisher-Copenhagen F1 rat, cRABP was present in the lateral lobe, but could not be detected in the ventral nor in the dorsal prostatic lobes. Four sublines of the R-3327 rat prostatic tumor contained similar levels of this binding protein. The absence of cRABP in the normal tissue of origin of the R-3327 tumor, the rat dorsal prostate, and reappearance in the neoplastic tissues follows a pattern described in other human and animal tumors. The occurrence of cRABP in the well-differentiated as well as in the anaplastic R-3327 tumors in which markers which reflect a state of differentiation and hormonal regulation, such as androgen receptor, 5 alpha reductase, and secretory acid phosphatase are either markedly reduced or absent, points to cRABP as a marker of malignant transformation. PMID:6283503

  14. Interferon regulatory factor-1 binds c-Cbl, enhances mitogen activated protein kinase signaling and promotes retinoic acid-induced differentiation of HL-60 human myelo-monoblastic leukemia cells

    PubMed Central

    Shen, Miaoqing; Bunaciu, Rodica P.; Congleton, Johanna; Jensen, Holly A.; Sayam, Lavanya G.; Varner, Jeffrey D.; Yen, Andrew

    2014-01-01

    All-trans retinoic acid (RA) and interferons (IFNs) have efficacy in treating certain leukemias and lymphomas, respectively, motivating interest in their mechanism of action to improve therapy. Both RA and IFNs induce interferon regulatory factor-1 (IRF-1). We find that in HL-60 myeloblastic leukemia cells which undergo mitogen activated protien kinase (MAPK)-dependent myeloid differentiation in response to RA, IRF-1 propels differentiation. RA induces MAPK-dependent expression of IRF-1. IRF-1 binds c-Cbl, a MAPK related adaptor. Ectopic IRF-1 expression causes CD38 expression and activation of the Raf/MEK/ERK axis, and enhances RA-induced differentiation by augmenting CD38, CD11b, respiratory burst and G0 arrest. Ectopic IRF-1 expression also decreases the activity of aldehyde dehydrogenase 1, a stem cell marker, and enhances RA-induced ALDH1 down-regulation. Interestingly, expression of aryl hydrocarbon receptor (AhR), which is RA-induced and known to down-regulate Oct4 and drive RA-induced differentiation, also enhances IRF-1 expression. The data are consistent with a model whereby IRF-1 acts downstream of RA and AhR to enhance Raf/MEK/ERK activation and propel differentiation. PMID:21740303

  15. All-trans retinoic acid modulates mitogen-activated protein kinase pathway activation in human scleral fibroblasts through retinoic acid receptor beta

    PubMed Central

    Huo, Lijun; Cui, Dongmei; Yang, Xiao; Gao, Zhenya; Trier, Klaus

    2013-01-01

    Purpose All-trans retinoic acid (ATRA) is known to inhibit the proliferation of human scleral fibroblasts (HSFs) and to modulate the scleral intercellular matrix composition, and may therefore serve as a mediator for controlling eye growth. Cell proliferation is regulated by the mitogen-activated protein kinase (MAPK) pathway. The aim of the current study was to investigate whether changed activation of the MAPK pathway could be involved in the response of HSFs exposed to ATRA. Methods HSFs were cultured in Dulbecco Modified Eagle's Medium/F12 (DMEM/F12) and exposed to 1 μmol/l ATRA for 10 min, 30 min, 1 h, 8 h, or 24 h. The activation of extracellular signal-regulated kinase (ERK 1/2), p38, and c-Jun N-terminal kinase (JNK) in HSFs was assessed with western blot analysis and immunocytofluorescence. Results After exposure to ATRA for 24 h, the HSFs appeared shrunken and thinner than the control cells. The intercellular spaces were wider, and the HSFs appeared less numerous than in the control culture. Western blot showed decreased activation of ERK 1/2 in the HSFs from 30 min (p=0.01) to 24 h (p<0.01) after the start of exposure to ATRA, and increased activation of the JNK protein from 10 to 30 min (p<0.01) after the start of exposure to ATRA. Indirect immunofluorescence confirmed changes in activation of ERK 1/2 and JNK in HSFs exposed to ATRA. No change in activation of p38 in HSFs was observed after exposure to ATRA. Pretreatment of the HSFs with LE135, an antagonist of retinoic acid receptor beta (RARβ), abolished the ATRA-induced changes inactivation of ERK 1/2 and JNK. Conclusions ATRA inhibits HSF proliferation by a mechanism associated with modulation of ERK 1/2 and JNK activation and depends on stimulation of retinoic acid receptor beta. PMID:23946634

  16. Morphological and functional differentiation in BE(2)-M17 human neuroblastoma cells by treatment with Trans-retinoic acid

    PubMed Central

    2013-01-01

    Background Immortalized neuronal cell lines can be induced to differentiate into more mature neurons by adding specific compounds or growth factors to the culture medium. This property makes neuronal cell lines attractive as in vitro cell models to study neuronal functions and neurotoxicity. The clonal human neuroblastoma BE(2)-M17 cell line is known to differentiate into a more prominent neuronal cell type by treatment with trans-retinoic acid. However, there is a lack of information on the morphological and functional aspects of these differentiated cells. Results We studied the effects of trans-retinoic acid treatment on (a) some differentiation marker proteins, (b) types of voltage-gated calcium (Ca2+) channels and (c) Ca2+-dependent neurotransmitter ([3H] glycine) release in cultured BE(2)-M17 cells. Cells treated with 10 μM trans-retinoic acid (RA) for 72 hrs exhibited marked changes in morphology to include neurite extensions; presence of P/Q, N and T-type voltage-gated Ca2+ channels; and expression of neuron specific enolase (NSE), synaptosomal-associated protein 25 (SNAP-25), nicotinic acetylcholine receptor α7 (nAChR-α7) and other neuronal markers. Moreover, retinoic acid treated cells had a significant increase in evoked Ca2+-dependent neurotransmitter release capacity. In toxicity studies of the toxic gas, phosgene (CG), that differentiation of M17 cells with RA was required to see the changes in intracellular free Ca2+ concentrations following exposure to CG. Conclusion Taken together, retinoic acid treated cells had improved morphological features as well as neuronal characteristics and functions; thus, these retinoic acid differentiated BE(2)-M17 cells may serve as a better neuronal model to study neurobiology and/or neurotoxicity. PMID:23597229

  17. Changes in Gene Expression Profiling of Apoptotic Genes in Neuroblastoma Cell Lines upon Retinoic Acid Treatment

    PubMed Central

    Celay, Jon; Blanco, Idoia; Lázcoz, Paula; Rotinen, Mirja; Castresana, Javier S.; Encío, Ignacio

    2013-01-01

    To determine the effect of retinoic acid (RA) in neuroblastoma we treated RA sensitive neuroblastoma cell lines with 9-cis RA or ATRA for 9 days, or for 5 days followed by absence of RA for another 4 days. Both isomers induced apoptosis and reduced cell density as a result of cell differentiation and/or apoptosis. Flow cytometry revealed that 9-cis RA induced apoptosis more effectively than ATRA. The expression profile of apoptosis and survival pathways was cell line specific and depended on the isomer used. PMID:23650528

  18. Three conazoles increase hepatic microsomal retinoic acid metabolism and decrease mouse hepatic retinoic acid levels in vivo

    SciTech Connect

    Chen, P.-J.; Padgett, William T.; Moore, Tanya; Winnik, Witold; Lambert, Guy R.; Thai, Sheau-Fung; Hester, Susan D.; Nesnow, Stephen

    2009-01-15

    Conazoles are fungicides used in agriculture and as pharmaceuticals. In a previous toxicogenomic study of triazole-containing conazoles we found gene expression changes consistent with the alteration of the metabolism of all trans-retinoic acid (atRA), a vitamin A metabolite with cancer-preventative properties (Ward et al., Toxicol. Pathol. 2006; 34:863-78). The goals of this study were to examine effects of propiconazole, triadimefon, and myclobutanil, three triazole-containing conazoles, on the microsomal metabolism of atRA, the associated hepatic cytochrome P450 (P450) enzyme(s) involved in atRA metabolism, and their effects on hepatic atRA levels in vivo. The in vitro metabolism of atRA was quantitatively measured in liver microsomes from male CD-1 mice following four daily intraperitoneal injections of propiconazole (210 mg/kg/d), triadimefon (257 mg/kg/d) or myclobutanil (270 mg/kg/d). The formation of both 4-hydroxy-atRA and 4-oxo-atRA were significantly increased by all three conazoles. Propiconazole-induced microsomes possessed slightly greater metabolizing activities compared to myclobutanil-induced microsomes. Both propiconazole and triadimefon treatment induced greater formation of 4-hydroxy-atRA compared to myclobutanil treatment. Chemical and immuno-inhibition metabolism studies suggested that Cyp26a1, Cyp2b, and Cyp3a, but not Cyp1a1 proteins were involved in atRA metabolism. Cyp2b10/20 and Cyp3a11 genes were significantly over-expressed in the livers of both triadimefon- and propiconazole-treated mice while Cyp26a1, Cyp2c65 and Cyp1a2 genes were over-expressed in the livers of either triadimefon- or propiconazole-treated mice, and Cyp2b10/20 and Cyp3a13 genes were over-expressed in the livers of myclobutanil-treated mice. Western blot analyses indicated conazole induced-increases in Cyp2b and Cyp3a proteins. All three conazoles decreased hepatic atRA tissue levels ranging from 45-67%. The possible implications of these changes in hepatic atRA levels

  19. Retinoic Acid as a Modulator of T Cell Immunity

    PubMed Central

    Bono, Maria Rosa; Tejon, Gabriela; Flores-Santibañez, Felipe; Fernandez, Dominique; Rosemblatt, Mario; Sauma, Daniela

    2016-01-01

    Vitamin A, a generic designation for an array of organic molecules that includes retinal, retinol and retinoic acid, is an essential nutrient needed in a wide array of aspects including the proper functioning of the visual system, maintenance of cell function and differentiation, epithelial surface integrity, erythrocyte production, reproduction, and normal immune function. Vitamin A deficiency is one of the most common micronutrient deficiencies worldwide and is associated with defects in adaptive immunity. Reports from epidemiological studies, clinical trials and experimental studies have clearly demonstrated that vitamin A plays a central role in immunity and that its deficiency is the cause of broad immune alterations including decreased humoral and cellular responses, inadequate immune regulation, weak response to vaccines and poor lymphoid organ development. In this review, we will examine the role of vitamin A in immunity and focus on several aspects of T cell biology such as T helper cell differentiation, function and homing, as well as lymphoid organ development. Further, we will provide an overview of the effects of vitamin A deficiency in the adaptive immune responses and how retinoic acid, through its effect on T cells can fine-tune the balance between tolerance and immunity. PMID:27304965

  20. Retinoic Acid as a Modulator of T Cell Immunity.

    PubMed

    Bono, Maria Rosa; Tejon, Gabriela; Flores-Santibañez, Felipe; Fernandez, Dominique; Rosemblatt, Mario; Sauma, Daniela

    2016-01-01

    Vitamin A, a generic designation for an array of organic molecules that includes retinal, retinol and retinoic acid, is an essential nutrient needed in a wide array of aspects including the proper functioning of the visual system, maintenance of cell function and differentiation, epithelial surface integrity, erythrocyte production, reproduction, and normal immune function. Vitamin A deficiency is one of the most common micronutrient deficiencies worldwide and is associated with defects in adaptive immunity. Reports from epidemiological studies, clinical trials and experimental studies have clearly demonstrated that vitamin A plays a central role in immunity and that its deficiency is the cause of broad immune alterations including decreased humoral and cellular responses, inadequate immune regulation, weak response to vaccines and poor lymphoid organ development. In this review, we will examine the role of vitamin A in immunity and focus on several aspects of T cell biology such as T helper cell differentiation, function and homing, as well as lymphoid organ development. Further, we will provide an overview of the effects of vitamin A deficiency in the adaptive immune responses and how retinoic acid, through its effect on T cells can fine-tune the balance between tolerance and immunity. PMID:27304965

  1. Retinoic Acid and Affective Disorders: The Evidence for an Association

    PubMed Central

    Bremner, J Douglas; Shearer, Kirsty; McCaffery, Peter

    2011-01-01

    Objective Isotretinoin (13-cis-retinoic acid, or 13-cis-RA) (Accutane), approved by the FDA for the treatment of acne, carries a black box warning related to the risk of depression, suicide, and psychosis. Retinoic acid (RA), the active form of vitamin A, regulates gene expression in the brain, and isotretinoin is its 13-cis isomer. Retinoids represent a group of compounds derived from vitamin A that perform a large variety of functions in many systems, in particular the CNS, and abnormal retinoid levels can have neurological effects. Although infrequent, proper recognition and treatment of psychiatric side effects in acne patients is critical given the risk of death and disability. This paper reviews the evidence for a relationship between isotretinoin, depression and suicidality. Data Sources Evidence examined includes: 1) case reports; 2) temporal association between onset of depression and exposure to the drug; 3) challenge-rechallenge cases; 4) class effect (other compounds in the same class, like vitamin A, having similar neuropsychiatric effects); 5) dose response; and 6) biologically plausible mechanisms. Study Selection All papers in the literature related to isotretinoin, depression and suicide were reviewed, as well as papers related to class effect, dose response, and biological plausibility. Data Extraction Information from individual articles in the literature was extracted. Data Synthesis The literature reviewed is consistent with an association between isotretinoin administration, depression and suicide in some individuals. Conclusions The relationship between isotretinoin and depression may have implications for a greater understanding of the neurobiology of affective disorders. PMID:21903028

  2. Retinoic acid stimulation of human dermal fibroblast proliferation is dependent on suboptimal extracellular Ca2+ concentration

    SciTech Connect

    Varani, J.; Shayevitz, J.; Perry, D.; Mitra, R.S.; Nickoloff, B.J.; Voorhees, J.J. )

    1990-06-01

    Human dermal fibroblasts failed to proliferate when cultured in medium containing 0.15 mmol/l (millimolar) Ca2+ (keratinocyte growth medium (KGM)) but did when the external Ca2+ concentration was raised to 1.4 mmol/l. All-trans retinoic acid (retinoic acid) stimulated proliferation in KGM but did not further stimulate growth in Ca2(+)-supplemented KGM. The ability of retinoic acid to stimulate proliferation was inhibited in KGM prepared without Ca2+ or prepared with 0.03 mmol/l Ca2+ and in KGM treated with 1 mmol/l ethylene-glycol-bis-(beta-aminoethyl ether)N,N'-tetra acetic acid. Using 45Ca2+ to measure Ca2+ influx and efflux, it was found that retinoic acid minimally increased Ca2+ uptake into fibroblasts. In contrast, retinoic acid treatment of fibroblasts that had been pre-equilibrated for 1 day with 45Ca2+ inhibited release of intracellular Ca2+ into the extracellular fluid. Retinoic acid also stimulated 35S-methionine incorporation into trichloroacetic acid-precipitable material but in contrast to its effect on proliferation, stimulation of 35S-methionine incorporation occurred in both high-Ca2+ and low-Ca2+ medium. These data indicate that retinoic acid stimulation of proliferation, but not protein synthesis, is dependent on the concentration of Ca2+ in the extracellular environment.

  3. Genetic selection for modulators of a retinoic-acid-responsive reporter in human cells.

    PubMed Central

    Richards, Burt; Karpilow, Jon; Dunn, Christine; Peterson, Isaac; Maxfield, Andrew; Zharkikh, Ludmilla; Abedi, Majid; Hurlburt, Anthony; Hardman, Joshua; Hsu, Forrest; Li, Wenhua; Rebentisch, Matthew; Sandrock, Robert; Sandrock, Tanya; Kamb, Alexander; Teng, David H-F

    2003-01-01

    We used a genetic screening methodology, a human cell line bearing a retinoic-acid-responsive enhanced GFP reporter, and a flow sorter to recover dominant modulators of reporter expression. Four inducers and three suppressors that were fused to the C terminus of a protein scaffold for stability were isolated and their mechanisms of action studied. Mutagenesis experiments indicated that six of these dominant agents exerted their effects at the protein level. The single cDNA coding fragment that was isolated comprised the central 64-amino-acid section of human cyclophilin B, which contained its peptidyl-prolyl isomerase domain; this cyclophilin fragment repressed expression of the retinoic-acid-responsive reporter. The remaining clones encoded peptides shorter than 30 amino acids unrelated to known gene open reading frames. Genetic epistasis studies between the strongest inducer, R3, and a dominant-negative mutant of RARalpha suggest that the two factors function in the same pathway. Transcript microarray analyses suggest that R3 induced a subset of the retinoid-responsive genes in melanoma cells. Finally, yeast two-hybrid assays and co-immunoprecipitation studies of human cell extracts identified PAT1 as a protein that interacts with R3. PMID:12663543

  4. Retinol dehydrogenase 10 but not retinol/sterol dehydrogenase(s) regulates the expression of retinoic acid-responsive genes in human transgenic skin raft culture.

    PubMed

    Lee, Seung-Ah; Belyaeva, Olga V; Wu, Lizhi; Kedishvili, Natalia Y

    2011-04-15

    Retinoic acid is essential for skin growth and differentiation, and its concentration in skin is controlled tightly. In humans, four different members of the short-chain dehydrogenase/reductase (SDR) superfamily of proteins were proposed to catalyze the rate-limiting step in the biosynthesis of retinoic acid (the oxidation of retinol to retinaldehyde). Epidermis contains at least three of these enzymes, but their relative importance for retinoic acid biosynthesis and regulation of gene expression during growth and differentiation of epidermis is not known. Here, we investigated the effect of the four human SDRs on retinoic acid biosynthesis, and their impact on growth and differentiation of keratinocytes using organotypic skin raft culture model of human epidermis. The results of this study demonstrate that ectopic expression of retinol dehydrogenase 10 (RDH10, SDR16C4) in skin rafts dramatically increases proliferation and inhibits differentiation of keratinocytes, consistent with the increased steady-state levels of retinoic acid and activation of retinoic acid-inducible genes in RDH10 rafts. In contrast, SDRs with dual retinol/sterol substrate specificity, namely retinol dehydrogenase 4 (RoDH4, SDR9C8), RoDH-like 3α-hydroxysteroid dehydrogenase (RL-HSD, SDR9C6), and RDH-like SDR (RDHL, SDR9C4) do not affect the expression of retinoic acid-inducible genes but alter the expression levels of several components of extracellular matrix. These results reveal essential differences in the metabolic contribution of RDH10 versus retinol/sterol dehydrogenases to retinoic acid biosynthesis and provide the first evidence that non-retinoid metabolic products of retinol/sterol dehydrogenases affect gene expression in human epidermis. PMID:21345790

  5. Retinol Dehydrogenase 10 but Not Retinol/Sterol Dehydrogenase(s) Regulates the Expression of Retinoic Acid-responsive Genes in Human Transgenic Skin Raft Culture*

    PubMed Central

    Lee, Seung-Ah; Belyaeva, Olga V.; Wu, Lizhi; Kedishvili, Natalia Y.

    2011-01-01

    Retinoic acid is essential for skin growth and differentiation, and its concentration in skin is controlled tightly. In humans, four different members of the short-chain dehydrogenase/reductase (SDR) superfamily of proteins were proposed to catalyze the rate-limiting step in the biosynthesis of retinoic acid (the oxidation of retinol to retinaldehyde). Epidermis contains at least three of these enzymes, but their relative importance for retinoic acid biosynthesis and regulation of gene expression during growth and differentiation of epidermis is not known. Here, we investigated the effect of the four human SDRs on retinoic acid biosynthesis, and their impact on growth and differentiation of keratinocytes using organotypic skin raft culture model of human epidermis. The results of this study demonstrate that ectopic expression of retinol dehydrogenase 10 (RDH10, SDR16C4) in skin rafts dramatically increases proliferation and inhibits differentiation of keratinocytes, consistent with the increased steady-state levels of retinoic acid and activation of retinoic acid-inducible genes in RDH10 rafts. In contrast, SDRs with dual retinol/sterol substrate specificity, namely retinol dehydrogenase 4 (RoDH4, SDR9C8), RoDH-like 3α-hydroxysteroid dehydrogenase (RL-HSD, SDR9C6), and RDH-like SDR (RDHL, SDR9C4) do not affect the expression of retinoic acid-inducible genes but alter the expression levels of several components of extracellular matrix. These results reveal essential differences in the metabolic contribution of RDH10 versus retinol/sterol dehydrogenases to retinoic acid biosynthesis and provide the first evidence that non-retinoid metabolic products of retinol/sterol dehydrogenases affect gene expression in human epidermis. PMID:21345790

  6. Solid Lipid Nanoparticles Loaded with Retinoic Acid and Lauric Acid as an Alternative for Topical Treatment of Acne Vulgaris.

    PubMed

    Silva, Elton Luiz; Carneiro, Guilherme; De Araújo, Lidiane Advíncula; Trindade, Mariana de Jesus Vaz; Yoshida, Maria Irene; Oréfice, Rodrigo Lambert; Farias, Luis de Macêdo; De Carvalho, Maria Auxiliadora Roque; Dos Santos, Simone Gonçalves; Goulart, Gisele Assis Castro; Alves, Ricardo José; Ferreira, Lucas Antônio Miranda

    2015-01-01

    Topical therapy is the first choice for the treatment of mild to moderate acne and all-trans retinoic acid is one of the most used drugs. The combination of retinoids and antimicrobials is an innovative approach for acne therapy. Recently, lauric acid, a saturated fatty acid, has shown strong antimicrobial activity against Propionibacterium acnes. However, topical application of retinoic acid is followed by high incidence of side-effects, including erythema and irritation. Solid lipid nanoparticles represent an alternative to overcome these side-effects. This work aims to develop solid lipid nanoparticles loaded with retinoic acid and lauric acid and evaluate their antibacterial activity. The influence of lipophilic stearylamine on the characteristics of solid lipid nanoparticles was investigated. Solid lipid nanoparticles were characterized for size, zeta potential, encapsulation efficiency, differential scanning calorimetry and X-ray diffraction. The in vitro inhibitory activity of retinoic acid-lauric acid-loaded solid lipid nanoparticles was evaluated against Propionibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis. High encapsulation efficiency was obtained at initial time (94 ± 7% and 100 ± 4% for retinoic acid and lauric acid, respectively) and it was demonstrated that lauric acid-loaded-solid lipid nanoparticles provided the incorporation of retinoic acid. However, the presence of stearylamine is necessary to ensure stability of encapsulation. Moreover, retinoic acid-lauric acid-loaded solid lipid nanoparticles showed growth inhibitory activity against Staphylococcus epidermidis, Propionibacterium acnes and Staphylococcus aureus, representing an interesting alternative for the topical therapy of acne vulgaris. PMID:26328443

  7. In vitro formation of retinoic acid from retinal in rat liver.

    PubMed

    Hupert, J; Mobarhan, S; Layden, T J; Papa, V M; Lucchesi, D J

    1991-08-01

    Enzymatic conversion of retinal to retinoic acid in rat liver cytosol was detected using a rapid and sensitive assay based on high pressure liquid chromatography (HPLC). This retinal oxidase assay system did not require extraction steps or any other manipulation of the sample mixture once the sample vial was sealed for incubation. The product (retinoic acid) and the reactant (retinal) were separated by HPLC in 14.0 min with a sensitivity of 15 and 40 pmol per injection for retinoic acid and retinal, respectively. Enzymatic activity was observed to be linear with protein concentration (0-2.4 mg/mL) and time (0-30 min) and displayed a broad pH maximum of 7.7-9.7. The enzyme exhibited Michaelis-Menten single-substrate kinetics with an apparent Km of 0.25 mM. The average specific activity in nine normal rats was 35.6 +/- 3.3 nmol retinoic acid formed/h per mg protein. Incubation of the enzyme with zinc did not affect the rate of retinoic acid synthesis. Dithiothreitol inhibited the reaction. Both NAD and NADH stimulated retinoic acid formation. Formation of retinol was also observed when these pyridine nucleotides were added to the reaction mixture, indicating the presence of retinal reductase activity. The results of kinetic studies suggest that NADH may act indirectly to stimulate retinoic acid formation. PMID:1760155

  8. Distinct binding determinants for 9-cis retinoic acid are located within AF-2 of retinoic acid receptor alpha.

    PubMed Central

    Tate, B F; Allenby, G; Janocha, R; Kazmer, S; Speck, J; Sturzenbecker, L J; Abarzúa, P; Levin, A A; Grippo, J F

    1994-01-01

    Retinoids exert their physiological action by interacting with two families of nuclear receptors, the retinoic acid receptors (RARs) and the retinoid X receptors (RXRs), which regulate gene expression by forming transcriptionally active heterodimeric RAR/RXR or homodimeric RXR/RXR complexes on DNA. Retinoid receptor activity resides in several regions, including the DNA and ligand binding domains, a dimerization interface, and both a ligand-independent (AF-1) and a ligand-dependent (AF-2) transactivation function. While 9-cis retinoic acid (RA) alone is the cognate ligand for the RXRs, both 9-cis RA and all-trans RA (t-RA) compete for binding with high affinity to the RARs. This latter observation suggested to us that the two isomers may interact with a common binding site. Here we report that RAR alpha has two distinct but overlapping binding sites for 9-cis RA and t-RA. Truncation of a human RAR alpha to 419 amino acids yields a receptor that binds both t-RA and 9-cis RA with high affinity, but truncation to amino acid 404 yields a mutant receptor that binds only t-RA with high affinity. Remarkably, this region also defines a C-terminal boundary for AF-2, as addition of amino acids 405 to 419 restores receptor-mediated gene activity to a truncated human RAR alpha lacking this region. It is interesting to speculate that binding of retinoid stereoisomers to unique sites within an RAR may function with AF-2 to cause differential activation of retinoid-responsive gene pathways. Images PMID:8139538

  9. Retinol metabolism in LLC-PK1 Cells. Characterization of retinoic acid synthesis by an established mammalian cell line.

    PubMed

    Napoli, J L

    1986-10-15

    Specific assays, based on gas chromatography-mass spectrometry and high-performance liquid chromatography, were used to quantify the conversion of retinol and retinal into retinoic acid by the pig kidney cell line LLC-PK1. Retinoic acid synthesis was linear for 2-4 h as well as with graded amounts of either substrate to at least 50 microM. Retinoic acid concentrations increased through 6-8 h, but decreased thereafter because of substrate depletion (t1/2 of retinol = 13 h) and product metabolism (1/2 = 2.3 h). Retinoic acid metabolism was accelerated by treating cells with 100 nM retinoic acid for 10 h (t1/2 = 1.7 h) and was inhibited by the antimycotic imidazole ketoconazole. Feedback inhibition was not indicated since retinoic acid up to 100 nM did not inhibit its own synthesis. Retinol dehydrogenation was rate-limiting. The reduction and dehydrogenation of retinal were 4-8-fold and 30-60-fold faster, respectively. Greater than 95% of retinol was converted into metabolites other than retinoic acid, whereas the major metabolite of retinal was retinoic acid. The synthetic retinoid 13-cis-N-ethylretinamide inhibited retinoic acid synthesis, but 4-hydroxylphenylretinamide did not. 4'-(9-Acridinylamino)methanesulfon-m-anisidide, an inhibitor of aldehyde oxidase, and ethanol did not inhibit retinoic acid synthesis. 4-Methylpyrazole was a weak inhibitor: disulfiram was a potent inhibitor. These data indicate that retinol dehydrogenase is a sulfhydryl group-dependent enzyme, distinct from ethanol dehydrogenase. Homogenates of LLC-PK1 cells converted retinol into retinoic acid and retinyl palmitate and hydrolyzed retinyl palmitate. This report suggests that substrate availability, relative to enzyme activity/amount, is a primary determinant of the rate of retinoic acid synthesis, identifies inhibitors of retinoic acid synthesis, and places retinoic acid synthesis into perspective with several other known pathways of retinoid metabolism. PMID:3759984

  10. Retinoic acid regulates embryonic development of mammalian submandibular salivary glands.

    PubMed

    Wright, Diana M; Buenger, Deanna E; Abashev, Timur M; Lindeman, Robert P; Ding, Jixiang; Sandell, Lisa L

    2015-11-01

    Organogenesis is orchestrated by cell and tissue interactions mediated by molecular signals. Identification of relevant signals, and the tissues that generate and receive them, are important goals of developmental research. Here, we demonstrate that Retinoic Acid (RA) is a critical signaling molecule important for morphogenesis of mammalian submandibular salivary glands (SMG). By examining late stage RA deficient embryos of Rdh10 mutant mice we show that SMG development requires RA in a dose-dependent manner. Additionally, we find that active RA signaling occurs in SMG tissues, arising earlier than any other known marker of SMG development and persisting throughout gland morphogenesis. At the initial bud stage of development, we find RA production occurs in SMG mesenchyme, while RA signaling occurs in epithelium. We also demonstrate active RA signaling occurs in glands cultured ex vivo, and treatment with an inhibitor of RA signaling blocks growth and branching. Together these data identify RA signaling as a direct regulator of SMG organogenesis. PMID:26278034

  11. Retinoic acid-binding protein, rhombomeres and the neural crest.

    PubMed

    Maden, M; Hunt, P; Eriksson, U; Kuroiwa, A; Krumlauf, R; Summerbell, D

    1991-01-01

    We have investigated by immunocytochemistry the spatial and temporal distribution of cellular retinoic acid-binding protein (CRABP) in the developing nervous system of the chick embryo in order to answer two specific questions: do neural crest cells contain CRABP and where and when do CRABP-positive neuroblasts first arise in the neural tube? With regard to the neural crest, we have compared CRABP staining with HNK-1 staining (a marker of migrating neural crest) and found that they do indeed co-localise, but cephalic and trunk crest behave slightly differently. In the cephalic region in tissues such as the frontonasal mass and branchial arches, HNK-1 immunoreactivity is intense at early stages, but it disappears as CRABP immunoreactivity appears. Thus the two staining patterns do not overlap, but are complementary. In the trunk, HNK-1 and CRABP stain the same cell populations at the same time, such as those migrating through the anterior halves of the somites. In the neural tube, CRABP-positive neuroblasts first appear in the rhombencephalon just after the neural folds close and then a particular pattern of immunoreactivity appears within the rhombomeres of the hindbrain. Labelled cells are present in the future spinal cord, the posterior rhombencephalon up to rhombomere 6 and in rhombomere 4 thus producing a single stripe pattern. This pattern is dynamic and gradually changes as anterior rhombomeres begin to label. The similarity of this initial pattern to the arrangement of certain homeobox genes in the mouse stimulated us to examine the expression of the chicken Hox-2.9 gene. We show that at stage 15 the pattern of expression of this gene is closely related to that of CRABP. The relationship between retinoic acid, CRABP and homeobox genes is discussed. PMID:1707786

  12. The Retinoic Acid Receptor-α mediates human T-cell activation and Th2 cytokine and chemokine production

    PubMed Central

    Dawson, Harry D; Collins, Gary; Pyle, Robert; Key, Michael; Taub, Dennis D

    2008-01-01

    Background We have recently demonstrated that all-trans-retinoic acid (ATRA) and 9-cis-retinoic acid (9-cis RA) promote IL-4, IL-5 and IL-13 synthesis, while decreasing IFN-γ and TNF-α expression by activated human T cells and reduces the synthesis of IL-12p70 from accessory cells. Here, we have demonstrated that the observed effects using ATRA and 9-cis RA are shared with the clinically useful RAR ligand, 13-cis retinoic acid (13-cis RA), and the retinoic acid receptor-α (RAR-α)-selective agonist, AM580 but not with the RAR-β/γ ligand, 4-hydroxyphenylretinamide (4-HPR). Results The increase in type 2 cytokine production by these retinoids correlated with the expression of the T cell activation markers, CD69 and CD38. The RAR-α-selective agonist, AM580 recapitulated all of the T cell activation and type 2 cytokine-inducing effects of ATRA and 9-cis-RA, while the RAR-α-selective antagonist, RO 41–5253, inhibited these effects. Conclusion These results strongly support a role for RAR-α engagement in the regulation of genes and proteins involved with human T cell activation and type 2 cytokine production. PMID:18416830

  13. An adverse outcome pathway framework for neural tube and axial defects mediated by modulation of retinoic acid homeostasis.

    PubMed

    Tonk, Elisa C M; Pennings, Jeroen L A; Piersma, Aldert H

    2015-08-01

    Developmental toxicity can be caused through a multitude of mechanisms and can therefore not be captured through a single simple mechanistic paradigm. However, it may be possible to define a selected group of overarching mechanisms that might allow detection of the vast majority of developmental toxicants. Against this background, we have explored the usefulness of retinoic acid mediated regulation of neural tube and axial patterning as a general mechanism that, when perturbed, may result in manifestations of developmental toxicity that may cover a large part of malformations known to occur in experimental animals and in man. Through a literature survey, we have identified key genes in the regulation of retinoic acid homeostasis, as well as marker genes of neural tube and axial patterning, that may be used to detect developmental toxicants in in vitro systems. A retinoic acid-neural tube/axial patterning adverse outcome pathway (RA-NTA AOP) framework was designed. The framework was tested against existing data of flusilazole exposure in the rat whole embryo culture, the zebrafish embryotoxicity test, and the embryonic stem cell test. Flusilazole is known to interact with retinoic acid homeostasis, and induced common and unique NTA marker gene changes in the three test systems. Flusilazole-induced changes were similar in directionality to gene expression responses after retinoic acid exposure. It is suggested that the RA-NTA framework may provide a general tool to define mechanistic pathways and biomarkers of developmental toxicity that may be used in alternative in vitro assays for the detection of embryotoxic compounds. PMID:25461899

  14. Differential Incorporation of β-actin as A Component of RNA Polymerase II into Regulatory Regions of Stemness/Differentiation Genes in Retinoic Acid-Induced Differentiated Human Embryonic Carcinoma Cells

    PubMed Central

    Falahzadeh, Khadijeh; Shahhoseini, Maryam; Afsharian, Parvaneh

    2016-01-01

    Objective Nuclear actin is involved in transcription regulation by recruitment of histone modifiers and chromatin remodelers to the regulatory regions of active genes. In recent years, further attention has been focused on the role of actin as a nuclear protein in transcriptional processes. In the current study, the epigenetic role of nuclear actin on transcription regulation of two stemness (OCT4 and NANOG) and two differentiation) NESTIN and PAX6) marker genes was evaluated in a human embryonal carcinoma cell line (NT2) before and after differentiation induction. Materials and Methods In this experimental study, differentiation of embryonal cells was induced by retinoic acid (RA), and quantitative real-time polymerase chain reaction (PCR) was used to evaluate differential expression of marker genes before and 3 days after RA- induced differentiation. Chromatin immunoprecipitation (ChIP) coupled with real-time PCR was then undertaken to monitor the incorporation of β-actin, as a functional component of RNA polymerase II, in the regulatory regions of marker genes. Results Data showed significant change in nuclear actin incorporation into the promoter regions of NESTIN and PAX6 after RA-induction. Conclusion We emphasize the dynamic functional role of nuclear actin in differentiation of embryonal cells and its role as a subunit of RNA polymerase II. PMID:27540526

  15. Chronic retinoic acid treatment suppresses adult hippocampal neurogenesis, in close correlation with depressive-like behavior.

    PubMed

    Hu, Pu; Wang, Yu; Liu, Ji; Meng, Fan-Tao; Qi, Xin-Rui; Chen, Lin; van Dam, Anne-Marie; Joëls, Marian; Lucassen, Paul J; Zhou, Jiang-Ning

    2016-07-01

    Clinical studies have highlighted an association between retinoid treatment and depressive symptoms. As we had shown before that chronic application of all-trans retinoic acid (RA) potently activated the hypothalamus-pituitary-adrenal (HPA) stress axis, we here questioned whether RA also induced changes in adult hippocampal neurogenesis, a form of structural plasticity sensitive to stress and implicated in aspects of depression and hippocampal function. RA was applied intracerebroventricularly (i.c.v.) to adult rats for 19 days after which animals were subjected to tests for depressive-like behavior (sucrose preference) and spatial learning and memory (water maze) performance. On day 27, adult hippocampal neurogenesis and astrogliosis was quantified using BrdU (newborn cell survival), PCNA (proliferation), doublecortin (DCX; neuronal differentiation), and GFAP (astrocytes) as markers. RA was found to increase retinoic acid receptor-α (RAR-α) protein expression in the hippocampus, suggesting an activation of RA-induced signaling mechanisms. RA further potently suppressed cell proliferation, newborn cell survival as well as neurogenesis, but not astrogliosis. These structural plasticity changes were significantly correlated with scores for anhedonia, a core symptom of depression, but not with water maze performance. Our results suggest that RA-induced impairments in hippocampal neurogenesis correlate with depression-like symptoms but not with spatial learning and memory in this design. Thus, manipulations aimed to enhance neurogenesis may help ameliorate emotional aspects of RA-associated mood disorders. © 2016 Wiley Periodicals, Inc. PMID:26860546

  16. BIOCONCENTRATION AND METABOLISM OF ALL-TRANS RETINOIC ACID BY RANA SYLVATICA AND RANA CLAMITANS TADPOLES

    EPA Science Inventory

    Retinoids, which are Vitamin A derivatives, are important signaling molecules that regulate processes critical for development in all vertebrates. The objective of our study was to examine uptake and metabolism of all-trans retinoic acid...

  17. Cyclooxygenase-2 knockdown using retinoic acid chalcone (RAC), a promising therapeutic strategy for colon cancer

    PubMed Central

    Jiang, Chao; Wang, Qiong; Xu, Zhe; Li, Wei-Su; Chen, Che; Yao, Xue-Quan; Liu, Fu-Kun

    2015-01-01

    Retinoic acid is an effective agent in the treatment of epithelial and hematological malignancies. The present study demonstrates that retinoic acid chalcone (RAC), an analogue of retinoic acid inhibits cell proliferation and induces apoptosis in HCT-15 and CT26.WT colon cancer cell lines. In HCT-15 cells the percentage of apoptotic cells increased from 32.4 ± 3, 45.0 ± 3 to 72.6 ± 5% respectively at 10, 15 and 20 μg/mL compared to 3.7% in control. Similarly in CT26.WT cells the percentage increased from 28.6 ± 3, 41.2 ± 3 to 65.4 ± 5% on treatment with 10, 15 and 20 μg/mL concentrations of RAC after 72 h compared to 2.9 ± 1% in control. Western blotting, fluorescence-activated cell sorting analysis and reverse transcription-PCR assays were used to investigate these effects. RAC inhibited the overexpression of COX-2, PGE2 and PGE2 receptor (EP1 and EP4) in the colon cancer cell lines. RAC mediated inhibition of cell growth and induction of apoptosis through COX-2 inhibition was also confirmed by treating the HCT-15 and CT26.WT colon cancer cells with COX-2 inhibitor, indomethacin and transfection of cells with COX-2 small interfering RNA. In nude mice with tumor xenografts, treatment with RAC-supplemented diet caused inhibition of COX-2, PGE2, and PGE2 receptors (EP1, EP3, and EP4) in tumors. Thus RAC can be a potential candidate for the treatment of colon cancer through the inhibition of COX-2 expression and subsequent inhibition of PGE2 and PGE2 receptors. PMID:26269760

  18. Association between cytoplasmic CRABP2, altered retinoic acid signaling, and poor prognosis in glioblastoma.

    PubMed

    Liu, Rong-Zong; Li, Shuai; Garcia, Elizabeth; Glubrecht, Darryl D; Yin Poon, Ho; Easaw, Jacob C; Godbout, Roseline

    2016-06-01

    Retinoic acid (RA), a metabolite of vitamin A, is required for the regulation of growth and development. Aberrant expression of molecules involved in RA signaling has been reported in various cancer types including glioblastoma multiforme (GBM). Cellular retinoic acid-binding protein 2 (CRABP2) has previously been shown to play a key role in the transport of RA to retinoic acid receptors (RARs) to activate their transcription regulatory activity. Here, we demonstrate that CRABP2 is predominantly located in the cytoplasm of GBM tumors. Cytoplasmic, but not nuclear, CRABP2 levels in GBM tumors are associated with poor patient survival. Treatment of malignant glioma cell lines with RA results in a dose-dependent increase in accumulation of CRABP2 in the cytoplasm. CRABP2 knockdown reduces proliferation rates of malignant glioma cells, and enhances RA-induced RAR activation. Levels of CRYAB, a small heat shock protein with anti-apoptotic activity, and GFAP, an astrocyte-specific intermediate filament protein, are greatly reduced in CRABP2-depleted cells. Restoration of CRYAB expression partially but significantly reversed the effect of CRABP2 depletion on RAR activation. Our combined in vivo and in vitro data indicate that: (i) CRABP2 is an important determinant of clinical outcome in GBM patients, and (ii) the mechanism of action of CRABP2 in GBM involves sequestration of RA in the cytoplasm and activation of an anti-apoptotic pathway, thereby enhancing proliferation and preventing RA-mediated cell death and differentiation. We propose that reducing CRABP2 levels may enhance the therapeutic index of RA in GBM patients. GLIA 2016;64:963-976. PMID:26893190

  19. Application of retinoic acid improves form and function of tissue engineered corneal construct.

    PubMed

    Abidin, Fadhilah Z; Gouveia, Ricardo M; Connon, Che J

    2015-01-01

    Retinoic acid has recently been shown to control the phenotype and extracellular matrix composition of corneal stromal cells cultured in vitro as monolayers. This study set out to investigate the effects of retinoic acid on human corneal keratocytes within a 3D environment. Human corneal keratocytes were encapsulated in collagen gels, which were subsequently compressed under load, and cultured in serum-free media supplemented with 10 µM retinoic acid or DMSO vehicle for 30 days. Cell proliferation was quantified on selected days, while the expression of several important keratocytes markers was evaluated at day 30 using RT-PCR and immunoblotting. The weight and size of the collagen constructs were measured before and after hydration and contraction analyses. Retinoic acid enhanced keratocyte proliferation until day 30, whereas cells in control culture conditions showed reduced numbers after day 21. Both gene and protein expressions of keratocyte-characteristic proteoglycans (keratocan, lumican and decorin), corneal crystallins and collagen type I and V were significantly increased following retinoic acid supplementation. Retinoic acid also significantly reduced the expression of matrix metalloproteases 1, 3 and 9 while not increasing α-smooth muscle actin and fibronectin expression. Furthermore, these effects were also correlated with the ability of retinoic acid to significantly inhibit the contractility of keratocytes while allowing the build-up of corneal stromal extracellular matrix within the 3D constructs. Thus, retinoic acid supplementation represents a promising strategy to improve the phenotype of 3D-cultured keratocytes, and their usefulness as a model of corneal stroma for corneal biology and regenerative medicine applications. PMID:26496651

  20. Application of retinoic acid improves form and function of tissue engineered corneal construct

    PubMed Central

    Abidin, Fadhilah Z; Gouveia, Ricardo M; Connon, Che J

    2015-01-01

    ABSTRACT Retinoic acid has recently been shown to control the phenotype and extracellular matrix composition of corneal stromal cells cultured in vitro as monolayers. This study set out to investigate the effects of retinoic acid on human corneal keratocytes within a 3D environment. Human corneal keratocytes were encapsulated in collagen gels, which were subsequently compressed under load, and cultured in serum-free media supplemented with 10 µM retinoic acid or DMSO vehicle for 30 days. Cell proliferation was quantified on selected days, while the expression of several important keratocytes markers was evaluated at day 30 using RT-PCR and immunoblotting. The weight and size of the collagen constructs were measured before and after hydration and contraction analyses. Retinoic acid enhanced keratocyte proliferation until day 30, whereas cells in control culture conditions showed reduced numbers after day 21. Both gene and protein expressions of keratocyte-characteristic proteoglycans (keratocan, lumican and decorin), corneal crystallins and collagen type I and V were significantly increased following retinoic acid supplementation. Retinoic acid also significantly reduced the expression of matrix metalloproteases 1, 3 and 9 while not increasing α-smooth muscle actin and fibronectin expression. Furthermore, these effects were also correlated with the ability of retinoic acid to significantly inhibit the contractility of keratocytes while allowing the build-up of corneal stromal extracellular matrix within the 3D constructs. Thus, retinoic acid supplementation represents a promising strategy to improve the phenotype of 3D-cultured keratocytes, and their usefulness as a model of corneal stroma for corneal biology and regenerative medicine applications. PMID:26496651

  1. The HER2 inhibitor TAK165 Sensitizes Human Acute Myeloid Leukemia Cells to Retinoic Acid-Induced Myeloid Differentiation by activating MEK/ERK mediated RARα/STAT1 axis.

    PubMed

    Shao, Xuejing; Liu, Yujia; Li, Yangling; Xian, Miao; Zhou, Qian; Yang, Bo; Ying, Meidan; He, Qiaojun

    2016-01-01

    The success of all-trans retinoic acid (ATRA) in differentiation therapy for patients with acute promyelocytic leukemia (APL) highly encourages researches to apply this therapy to other types of acute myeloid leukemia (AML). However, AML, with the exception of APL, fails to respond to differentiation therapy. Therefore, research strategies to further sensitize cells to retinoids and to extend the range of AMLs that respond to retinoids beyond APLs are urgently needed. In this study, we showed that TAK165, a HER2 inhibitor, exhibited a strong synergy with ATRA to promote AML cell differentiation. We observed that TAK165 sensitized the AML cells to ATRA-induced cell growth inhibition, G0/G1 phase arrest, CD11b expression, mature morphologic changes, NBT reduction and myeloid regulator expression. Unexpectedly, HER2 pathway might not be essential for TAK165-enhanced differentiation when combined with ATRA, while the enhanced differentiation was dependent on the activation of the RARα/STAT1 axis. Furthermore, the MEK/ERK cascade regulated the activation of STAT1. Taken together, our study is the first to evaluate the synergy of TAK165 and ATRA in AML cell differentiation and to assess new opportunities for the combination of TAK165 and ATRA as a promising approach for future differentiation therapy. PMID:27074819

  2. The HER2 inhibitor TAK165 Sensitizes Human Acute Myeloid Leukemia Cells to Retinoic Acid-Induced Myeloid Differentiation by activating MEK/ERK mediated RARα/STAT1 axis

    PubMed Central

    Shao, Xuejing; Liu, Yujia; Li, Yangling; Xian, Miao; Zhou, Qian; Yang, Bo; Ying, Meidan; He, Qiaojun

    2016-01-01

    The success of all-trans retinoic acid (ATRA) in differentiation therapy for patients with acute promyelocytic leukemia (APL) highly encourages researches to apply this therapy to other types of acute myeloid leukemia (AML). However, AML, with the exception of APL, fails to respond to differentiation therapy. Therefore, research strategies to further sensitize cells to retinoids and to extend the range of AMLs that respond to retinoids beyond APLs are urgently needed. In this study, we showed that TAK165, a HER2 inhibitor, exhibited a strong synergy with ATRA to promote AML cell differentiation. We observed that TAK165 sensitized the AML cells to ATRA-induced cell growth inhibition, G0/G1 phase arrest, CD11b expression, mature morphologic changes, NBT reduction and myeloid regulator expression. Unexpectedly, HER2 pathway might not be essential for TAK165-enhanced differentiation when combined with ATRA, while the enhanced differentiation was dependent on the activation of the RARα/STAT1 axis. Furthermore, the MEK/ERK cascade regulated the activation of STAT1. Taken together, our study is the first to evaluate the synergy of TAK165 and ATRA in AML cell differentiation and to assess new opportunities for the combination of TAK165 and ATRA as a promising approach for future differentiation therapy. PMID:27074819

  3. Retinoic acid inhibits the cytoproliferative response to weak 50-Hz magnetic fields in neuroblastoma cells

    PubMed Central

    TRILLO, MARÍA ÁNGELES; MARTÍNEZ, MARÍA ANTONIA; CID, MARÍA ANTONIA; ÚBEDA, ALEJANDRO

    2012-01-01

    We previously reported that intermittent exposure to a 50-Hz magnetic field (MF) at 100 μT stimulates cell proliferation in the human neuroblastoma cell line NB69. The present study aimed to investigate whether the magnetic field-induced growth promotion also occurs at a lower magnetic flux density of 10 μT. To this purpose, NB69 cells were subjected for 42 h to intermittent exposure, 3 h on/3 h off, to a 50-Hz MF at a 10 or 100 μT magnetic flux density. The field exposure took place either in the presence or in the absence of the antiproliferative agent retinoic acid. At the end of the treatment and/or incubation period, the cell growth was estimated by hemocytometric counting and spectrophotometric analysis of total protein and DNA contents. Potential changes in DNA synthesis were also assessed through proliferating cell nuclear antigen (PCNA) immunolabeling. The results confirmed previously reported data that a 42-h exposure to a 50-Hz sine wave MF at 100 μT promotes cell growth in the NB69 cell line, and showed that 10 μT induces a similar proliferative response. This effect, which was significantly associated and linearly correlated with PCNA expression, was abolished by the presence of retinoic acid in the culture medium. PMID:23292364

  4. Identification of a microsomal retinoic acid synthase as a microsomal cytochrome P-450-linked monooxygenase system.

    PubMed

    Tomita, S; Tsujita, M; Matsuo, Y; Yubisui, T; Ichikawa, Y

    1993-12-01

    1. To characterize an enzyme which metabolizes retinal in liver microsomes, several properties of the enzymatic reaction from retinal to retinoic acid were investigated using rabbit liver microsomes. 2. The maximum pH of the reaction in the liver microsomes was 7.6. 3. The Km and Vmax values for all-trans, 9-cis and 13-cis-retinals were determined. 4. The reaction proceeded in the presence of NADPH and molecular oxygen. 5. The incorporation of one atom of molecular oxygen into retinal was confirmed by using oxygen-18, showing that the reaction comprised monooxygenation, not dehydrogenation. 6. The monooxygenase activity was inhibited by carbon monoxide, phenylisocyanide and anti-NADPH-cytochrome P-450 reductase IgG, but not by anti-cytochrome b5 IgG. 7. The enzymatic activity inhibited by carbon monoxide was photoreversibly restored by light of a wavelength of around 450 nm. 8. The retinal-induced spectra of liver microsomes with three isomeric retinals were type I spectra. 9. The microsomal monooxygenase activity induced by phenobarbital or ethanol were more effective than that by 3-methylcholanthrene, clotrimazole or beta-naphthoflavone. 10. These results showed that the monooxygenase reaction from retinal to retinoic acid in liver microsomes is catalyzed by a cytochrome P-450-linked monooxygenase system. PMID:8138015

  5. The role of Zic transcription factors in regulating hindbrain retinoic acid signaling

    PubMed Central

    2013-01-01

    Background The reiterated architecture of cranial motor neurons aligns with the segmented structure of the embryonic vertebrate hindbrain. Anterior-posterior identity of cranial motor neurons depends, in part, on retinoic acid signaling levels. The early vertebrate embryo maintains a balance between retinoic acid synthetic and degradative zones on the basis of reciprocal expression domains of the retinoic acid synthesis gene aldhehyde dehydrogenase 1a2 (aldh1a2) posteriorly and the oxidative gene cytochrome p450 type 26a1 (cyp26a1) in the forebrain, midbrain, and anterior hindbrain. Results This manuscript investigates the role of zinc finger of the cerebellum (zic) transcription factors in regulating levels of retinoic acid and differentiation of cranial motor neurons. Depletion of zebrafish Zic2a and Zic2b results in a strong downregulation of aldh1a2 expression and a concomitant reduction in activity of a retinoid-dependent transgene. The vagal motor neuron phenotype caused by loss of Zic2a/2b mimics a depletion of Aldh1a2 and is rescued by exogenously supplied retinoic acid. Conclusion Zic transcription factors function in patterning hindbrain motor neurons through their regulation of embryonic retinoic acid signaling. PMID:23937294

  6. Retinoic acid amide inhibits JAK/STAT pathway in lung cancer which leads to apoptosis.

    PubMed

    Li, Hong-Xing; Zhao, Wei; Shi, Yan; Li, Ya-Na; Zhang, Lian-Shuang; Zhang, Hong-Qin; Wang, Dong

    2015-11-01

    Small cell lung cancer (SCLC) accounts for 12 to 16% of lung neoplasms and has a high rate of metastasis. The present study demonstrates the antiproliferative effect of retinoic acid amide in vitro and in vivo against human lung cancer cells. The results from MTT assay showed a significant growth inhibition of six tested lung cancer cell lines and inhibition of clonogenic growth at 30 μM. Retinoic acid amide also leads to G2/M-phase cell cycle arrest and apoptosis of lung cancer cells. It caused inhibition of JAK2, STAT3, and STAT5, increased the level of p21WAF1, and decreased cyclin A, cyclin B1, and Bcl-XL expression. Retinoic acid amide exhibited a synergistic effect on antiproliferative effects of methotrexate in lung cancer cells. In lung tumor xenografts, the tumor volume was decreased by 82.4% compared to controls. The retinoic acid amide-treated tumors showed inhibition of JAK2/STAT3 activation and Bcl-XL expression. There was also increase in expression of caspase-3 and caspase-9 in tumors on treatment with retinoic acid amide. Thus, retinoic acid amide exhibits promising antiproliferative effects against human lung cancer cells in vitro and in vivo and enhances the antiproliferative effect of methotrexate. PMID:26044560

  7. MDI 301 suppresses myeloid leukemia cell growth in vitro and in vivo without the toxicity associated with all-trans retinoic acid therapy.

    PubMed

    Aslam, Muhammad N; McClintock, Shannon; Khan, Shazli P; Perone, Patricia; Allen, Ronald; Ouillette, Peter D; Dame, Michael K; Cheng, Jason X; Kunkel, Steven L; Varani, James

    2015-08-01

    MDI 301 is a novel 9-cis retinoic acid derivative in which the terminal carboxylic acid group has been replaced by a picolinate ester. MDI 301, a retinoic acid receptor-α - agonist, suppressed the growth of several human myeloid leukemia cell lines (HL60, NB4, OCI-M2, and K562) in vitro and induced cell-substrate adhesion in conjunction with upregulation of CD11b. Tumor growth in HL60-injected athymic nude mice was reduced. In vitro, MDI 301 was comparable to all-trans retinoic acid (ATRA) whereas in vivo, MDI 301 was slightly more efficacious than ATRA. Most importantly, unlike what was found with ATRA treatment, MDI 301 did not induce a cytokine response in the treated animals and the severe inflammatory changes and systemic toxicity seen with ATRA did not occur. A retinoid with these characteristics might be valuable in the treatment of promyelocytic leukemia, or, perhaps, other forms of myeloid leukemia. PMID:26010252

  8. Transglutaminase-2 Is Involved in All-Trans Retinoic Acid-Induced Invasion and Matrix Metalloproteinases Expression of SH-SY5Y Neuroblastoma Cells via NF-κB Pathway

    PubMed Central

    Lee, Hye Ja; Park, Mi Kyung; Bae, Hyun Cheol; Yoon, Hee Jung; Kim, Soo Youl; Lee, Chang Hoon

    2012-01-01

    All-trans retinoic acid (ATRA) is currently used in adjuvant differentiation-based treatment of residual or relapsed neuroblastoma (NB). It has been reported that short-term ATRA treatment induces migration and invasion of SH-SY5Y via transglutaminase-2 (Tgase-2). However, the detailed mechanism of Tgase-2's involvement in NB cell invasion remains unclear. Therefore we investigated the role of Tgase-2 in invasion of NB cells using SH-SY5Y cells. ATRA dose-dependently induced the invasion of SH-SY5Y cells. Cystamine (CTM), a well known tgase inhibitor suppressed the ATRA-induced invasion of SH-SY5Y cells in a dose-dependent manner. Matrix metalloproteinase-9 (MMP-9) and MMP-2, well known genes involved in invasion of cancer cells were induced in the ATRA-induced invasion of the SH-SH5Y cells. Treatment of CTM suppressed the MMP-9 and MMP-2 enzyme activities in the ATRA-induced invasion of the SH-SY5Y cells. To confirm the involvement of Tgase-2, gene silencing of Tgase-2 was performed in the ATRA-induced invasion of the SH-SH5Y cells. The siRNA of Tgase-2 suppressed the MMP-9 and MMP-2 activity of the SH-SY5Y cells. MMP-2 and MMP-9 are well known target genes of NF-κB. Therefore the relationship of Tgase-2 and NF-κB in the ATRA-induced invasion of the SH-SY5Y cells was examined using siRNA and CTM. ATRA induced the activation of NF-κB in the SH-SY5Y cells and CTM suppressed the activation of NF-κB. Gene silencing of Tgase-2 suppressed the MMP expression by ATRA. These results suggested that Tgase-2 might be a new target for controlling the ATRA-induced invasion of NBs. PMID:24130925

  9. Prospective teratology of retinoic acid metabolic blocking agents (RAMBAs) and loss of CYP26 activity.

    PubMed

    McCaffery, P; Simons, C

    2007-01-01

    All-trans retinoic acid (atRA) is the transcriptionally active product of vitamin A and induces gene expression via specific receptors at nM concentrations. Essential enzymes that regulate the local levels of atRA are the CYP26 members of the cytochrome P450 family, which catabolize atRA. Compounds that have been designed to inhibit these enzymes are known as Retinoic Acid Metabolic Blocking Agents (RAMBAs). Treatment with these compounds will raise endogenous atRA levels and may be therapeutic for the treatment of diseases that respond to high atRA concentrations, including several types of cancer as well as skin conditions such as psoriasis and acne. This review describes the mechanism of action of the RAMBAs and discusses the potential side effects of these compounds. atRA is highly teratogenic and the potential teratogenicity of the RAMBAs is described by comparison with the abnormalities resulting from null mutation of individual CYP26 genes. The possible effects of RAMBAs on the adult brain are also described that have the potential for harm but, in the right circumstances, may also be beneficial. PMID:17979744

  10. Reversal effects of topical retinoic acid on the skin of kidney transplant recipients under systemic corticotherapy.

    PubMed

    De Lacharriére, O; Escoffier, C; Gracia, A M; Teillac, D; Saint Léger, D; Berrebi, C; Debure, A; Lévêque, J L; Kreis, H; De Prost, Y

    1990-11-01

    The systemic long-term corticosteroid treatment administered to kidney graft recipients (KGR) within the framework of the required immunosuppressive therapy induces an atrophy of the skin, from the sixth month onwards. We studied the effect of topical all-trans retinoic acid (0.05%; Galderma Labs.) applied to the forearms of 27 KGR (14 men, 13 women) over a 6-month period. Twenty-four subjects completed the trial. The following results were obtained in the treated forearm versus the untreated forearm (excipient alone): clinically, an increase in skin thickness; by noninvasive techniques, an increase in skin thickness, skin elasticity, skin conductance, and TEWL, and a reduction in the size of the corneocytes. No change in stratum corneum lipid content was observed. A sex-related difference was noted in the response to treatment under our experimental conditions, the female patients responding better. A punch biopsy (4 mm) was performed on both forearms of four patients after the 6-month period. Histologic and ultrastructural examination revealed epidermal and dermal changes evoking increased cellular metabolism in the retinoic acid-treated forearms. PMID:2230213