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Sample records for activating retinoic acid

  1. [Biological activity of retinoic acid and methylretinoate].

    PubMed

    Dusheĭko, A A; Chernukhina, L A; Blazhevich, M A; Davydova, L P

    1980-01-01

    Vitamin A lack in the diet of chicken produces a significant increase in the glandular stomach as well as formation of erosions and ulcers on the surface of the mucous membrane of the intermediate zone. Replacement of retinyl acetate in the diet by retinoic acid or methyl retionate gives no rise to changes in the morphological integrity of the glandular stomach of the chickens. Moreover, these compounds produce a reverse development of vitamin A-induced changes. It is thus concluded that when the diet lacks vitamin A, both retinoic acid and methyl retionate are capable of maintaining the structural integrity of the stomach.

  2. 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.

  3. Fate of retinoic acid-activated embryonic cell lineages.

    PubMed

    Dollé, Pascal; Fraulob, Valérie; Gallego-Llamas, Jabier; Vermot, Julien; Niederreither, Karen

    2010-12-01

    Retinoic acid (RA), a vitamin A derivative, is synthesized by specific cell populations and acts as a diffusible embryonic signal activating ligand-inducible transcription factors, the RA receptors (RARs). RA-activatable transgenic systems have revealed many discrete, transient sites of RA action during development. However, there has been no attempt to permanently label the RA-activated cell lineages during mouse ontogenesis. We describe the characterization of a RA-activatable Cre transgene, which through crosses with a conditional reporter strain (the ROSA26R lacZ reporter), leads to a stable labeling of the cell populations experiencing RA signaling during embryogenesis. RA response-element (RARE)-driven Cre activity mimics at early stages the known activity of the corresponding RARE-lacZ transgene (Rossant et al.,1991). Stable labeling of the Cre-excised cell populations allows to trace the distribution of the RA-activated cell lineages at later stages. These are described in relationship with current models of RA activity in various developmental systems, including the embryonic caudal region, limb buds, hindbrain, sensory organs, and heart. PMID:21046629

  4. 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.

  5. 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

  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. Differential effects of prenatal cocaine and retinoic acid on activity level throughout day and night.

    PubMed

    Church, M W; Tilak, J P

    1996-12-01

    Prenatal cocaine exposure is associated with disrupted state control and lowered activity levels. Prenatal retinoic acid excess also influences activity levels in laboratory rats. Activity level is usually monitored during a brief period in young offspring. The effects of these drugs on pup activity levels throughout the day is unknown. There is also little information on the long-lasting effects of these teratogens in adult animals. We compared the daily activity of rats which were prenatally exposed to cocaine or retinoic acid (RA). Appropriate control groups were also used. The offspring were evaluated for activity levels in a neophobic situation and for a 22-h period in same-sex groups of 3 littermates. As both pups and adults, the cocaine groups were hypoactive while the RA group was hyperactive when first placed into the testing cage (neophobic situation). Similarly, during the remainder of the 22-h testing period, the pup and adult cocaine animals exhibited reduced activity levels while the RA animals exhibited elevated activity levels. Thus, prenatal cocaine and retinoic acid exposures affected offspring activity levels differently, both drugs have long-lasting neurobehavioral effects that persist into adulthood, and effects are influenced by time-of-day. Strain-dependent differences and mechanisms of action are discussed.

  8. 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.

  9. A widely used retinoic acid receptor antagonist induces peroxisome proliferator-activated receptor-gamma activity.

    PubMed

    Schupp, Michael; Curtin, Joshua C; Kim, Roy J; Billin, Andrew N; Lazar, Mitchell A

    2007-05-01

    Nuclear receptors (NRs) are transcription factors whose activity is regulated by the binding of small lipophilic ligands, including hormones, vitamins, and metabolites. Pharmacological NR ligands serve as important therapeutic agents; for example, all-trans retinoic acid, an activating ligand for retinoic acid receptor alpha (RARalpha), is used to treat leukemia. Another RARalpha ligand, (E)-S,S-dioxide-4-(2-(7-(heptyloxy)-3,4-dihydro-4,4-dimethyl-2H-1-benzothiopyran-6-yl)-1-propenyl)-benzoic acid (Ro 41-5253), is a potent antagonist that has been a useful and purportedly specific probe of RARalpha function. Here, we report that Ro 41-5253 also activates the peroxisome proliferator-activated receptor gamma (PPARgamma), a master regulator of adipocyte differentiation and target of widely prescribed antidiabetic thiazolidinediones (TZDs). Ro 41-5253 enhanced differentiation of mouse and human preadipocytes and activated PPARgamma target genes in mature adipocytes. Like the TZDs, Ro 41-5253 also down-regulated PPARgamma protein expression in adipocytes. In addition, Ro 41-5253 activated the PPARgamma-ligand binding domain in transiently transfected HEK293T cells. These effects were not prevented by a potent RARalpha agonist or by depleting cells of RARalpha, indicating that PPARgamma activation was not related to RARalpha antagonism. Indeed, Ro 41-5253 was able to compete with TZD ligands for binding to PPARgamma, suggesting that Ro 41-5253 directly affects PPAR activity. These results vividly demonstrate that pharmacological NR ligands may have "off-target" effects on other NRs. Ro 41-5253 is a PPARgamma agonist as well as an RARalpha antagonist whose pleiotropic effects on NRs may signify a unique spectrum of biological responses.

  10. Anti-osteoporosis activity of naringin in the retinoic acid-induced osteoporosis model.

    PubMed

    Wei, Min; Yang, Zhonglin; Li, Ping; Zhang, Yabo; Sse, Wing Cho

    2007-01-01

    Isoflavonoids isolated from plants have been confirmed to fight osteoporosis and promote bone health. However, few studies have been conducted to describe the anti-osteoporosis activity of botanical flavonone. Based on the experimental outcomes, we demonstrated the ability of naringin to fight osteoporosis in vitro. We developed a retinoic acid-induced osteoporosis model of rats to assess whether naringin has similar bioactivity against osteoporosis in vitro. After a 14-day supplement of retinoic acid to induce osteoporosis, SD rats were administered naringin. A blood test showed that naringin-treated rats experienced significantly lower activity of serum alkaline phosphatase and had higher femur bone mineral density, compared to untreated rats. All three dosages of naringin improved the decrease in bone weight coefficient, the length and the diameter of the bone, the content of bone ash, calcium, and phosphorus content induced by retinoic acid. The data of histomorphological metrology of naringin groups showed no difference as compared to normal control rats. These outcomes suggest that naringin offer a potential in the management of osteoporosis in vitro. PMID:17708632

  11. Molecular basis for designing selective modulators of retinoic acid receptor transcriptional activities.

    PubMed

    Lefebvre, P

    2001-08-01

    Retinoic acid receptors are ligand-regulated transcription factors belonging to the nuclear receptor superfamily, which comprises 49 members in the human genome. all-trans retinoic acid and 9-cis retinoic acid receptors (RARs and RXRs) are each encoded by three distinct genes and several isoforms arise from alternative splicing and the use of different promoters. While RXRs are promiscuous dimerization partners of several other nuclear receptors, RARs are active, in-vivo, when associated to RXRs. Retinoids are therefore regulators of multiple physiological processes, from embryogenesis to metabolism. Different combinations of RXR:RAR heterodimers occur as a function of their tissue-specific expression and their activity is mostly conditioned by the activation status of RAR. These heterodimers are defined as non permissive heterodimers, in opposition to permissive dimers whose transcriptional activity may be modulated through RXR and its dimerization partner. The transcriptional activity of these dimers also relies on their ability to recruit nuclear coactivators and corepressors, which function as multi proteic complexes harboring several enzymatic activities (acetylases, kinases). The structure of the ligand bound to the RAR moiety of the dimer, as well as the nature of the DNA sequence to which dimers are bound, dictate the relative affinity of dimers for coactivators and thus its overall transcriptional activity. RARs are also able to repress the activity of unrelated transcription factors such as AP1 and NF-kappa-B, and therefore have potent anti proliferative and anti inflammatory properties. This review summarizes our current view of molecular mechanisms governing these various activities and emphasizes the need for a detailed understanding of how retinoids may dictate transactivating and transrepressive properties of RARs and RXRs, which may be considered as highly valuable therapeutic targets in many diseases such as cancer, skin hyperproliferation and

  12. Survival of activated human T lymphocytes is promoted by retinoic acid via induction of IL-2.

    PubMed

    Engedal, Nikolai; Ertesvag, Aase; Blomhoff, Heidi Kiil

    2004-03-01

    At the end of an immune response, most activated T cells spontaneously undergo programmed cell death (apoptosis). In the present study we show that all-trans retinoic acid (atRA), a major vitamin A metabolite, can inhibit the spontaneous apoptosis of activated human T lymphocytes in vitro. Isolated peripheral blood T lymphocytes were activated by 12-O-tetradecanoyl phorbol 13-acetate and cultured for up to 11 days without any further stimuli. With time, a gradual increase in cell death was observed. This spontaneous death of activated T cells was apoptotic, as demonstrated by cell shrinkage, DNA fragmentation and depolarization of the mitochondrial membrane. In the presence of physiological concentrations of atRA, the percentage of T cells exhibiting these apoptotic features was significantly reduced. After 5 days of stimulation, the percentage of TUNEL+ T cells decreased from 28 to 12% in the presence of atRA. The anti-apoptotic effect of atRA was mimicked by the retinoic acid receptor (RAR)-selective agonists 4-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1-propenyl]benzoic acid and AM-580, and totally abrogated by the RAR-selective antagonist Ro 41-5253. Cytokines of the IL-2 family have been shown to improve the survival of activated T cells. Strikingly, we found that the ability of atRA to inhibit apoptosis was significantly correlated with its ability to increase the production of IL-2. Furthermore, a blocking anti-IL-2 receptor antibody completely abrogated the anti-apoptotic effect of atRA. Together, these results suggest that retinoic acid inhibits spontaneous apoptosis of activated T lymphocytes through a RAR-dependent increase in IL-2 production.

  13. Improved In Vitro Antileukemic Activity of All-Trans Retinoic Acid Loaded in Cholesteryl Butyrate Solid Lipid Nanoparticles.

    PubMed

    Silva, Elton Luiz; Lima, Flávia Alves; Carneiro, Guilherme; Ramos Jonas Periera; Gomes, Dawidson Assis; de Souza-Fagundes, Elaine Maria; Ferreira, Lucas Antônio Miranda

    2016-02-01

    All-trans retinoic acid, a hydrophobic drug, has become one of the most successful examples of differentiation agents used for treatment of acute promyelocytic leukemia. On the other hand, histone deacetylase inhibitors, such as cholesteryl butyrate, present differentiating activity and.can potentiate action of drugs such as all-trans retinoic acid. Solid lipid nanoparticles represent a promising alternative for administration of hydrophobic drugs such as ATRA. This study aimed to develop, characterize, and evaluate the cytotoxicity of all-trans retinoic acid-loaded solid lipid nanoparticles for leukemia treatment. The influence of in situ formation of an ion pairing between all-trans retinoic acid and lipophilic amines on the characteristics of the particles (size, zeta potential, encapsulation efficiency) was evaluated. Cholesteryl butyrate, a butyric acid donor, was used as a component of the lipid matrix. In vitro activity on cell viability and distribution of cell cycle phases were evaluated for HL-60, Jurkat, and THP-1 cell lines. The encapsulation efficiency of all-trans retinoic acid in cholesteryl butyrate-solid lipid nanoparticles was significantly increased by the presence of the amine. Inhibition of cell viability by all-trans retinoic acid-loaded solid lipid nanoparticles was more pronounced than the free drug. Analysis of the distribution of cell cycle phases also showed increased activity for all-trans retinoic acid-loaded cholesteryl butyrate-solid lipid nanoparticles, with a clear increase in subdiploid DNA content. The ion pair formation in SLN containing cholesteryl butyrate can be explored as a simple and inexpensive strategy to improve the efficacy and bioavail-ability of ATRA in the treatment of the cancer and metabolic diseases in which this retinoid plays an important role. PMID:27433579

  14. 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

  15. Retinoic acid response element in the human alcohol dehydrogenase gene ADH3: implications for regulation of retinoic acid synthesis.

    PubMed Central

    Duester, G; Shean, M L; McBride, M S; Stewart, M J

    1991-01-01

    Retinoic acid regulation of one member of the human class I alcohol dehydrogenase (ADH) gene family was demonstrated, suggesting that the retinol dehydrogenase function of ADH may play a regulatory role in the biosynthetic pathway for retinoic acid. Promoter activity of human ADH3, but not ADH1 or ADH2, was shown to be activated by retinoic acid in transient transfection assays of Hep3B human hepatoma cells. Deletion mapping experiments identified a region in the ADH3 promoter located between -328 and -272 bp which confers retinoic acid activation. This region was also demonstrated to confer retinoic acid responsiveness on the ADH1 and ADH2 genes in heterologous promoter fusions. Within a 34-bp stretch, the ADH3 retinoic acid response element (RARE) contains two TGACC motifs and one TGAAC motif, both of which exist in RAREs controlling other genes. A block mutation of the TGACC sequence located at -289 to -285 bp eliminated the retinoic acid response. As assayed by gel shift DNA binding studies, the RARE region (-328 to -272 bp) of ADH3 bound the human retinoic acid receptor beta (RAR beta) and was competed for by DNA containing a RARE present in the gene encoding RAR beta. Since ADH catalyzes the conversion of retinol to retinal, which can be further converted to retinoic acid by aldehyde dehydrogenase, these results suggest that retinoic acid activation of ADH3 constitutes a positive feedback loop regulating retinoic acid synthesis. Images PMID:1996113

  16. Retinoic acid synergizes ATO-mediated cytotoxicity by precluding Nrf2 activity in AML cells

    PubMed Central

    Valenzuela, M; Glorieux, C; Stockis, J; Sid, B; Sandoval, J M; Felipe, K B; Kviecinski, M R; Verrax, J; Calderon, P Buc

    2014-01-01

    Background: Standard therapy for acute promyelocytic leukaemia (APL) includes retinoic acid (all-trans retinoic acid (ATRA)), which promotes differentiation of promyelocytic blasts. Although co-administration of arsenic trioxide (ATO) with ATRA has emerged as an effective option to treat APL, the molecular basis of this effect remains unclear. Methods: Four leukaemia cancer human models (HL60, THP-1, NBR4 and NBR4-R2 cells) were treated either with ATO alone or ATO plus ATRA. Cancer cell survival was monitored by trypan blue exclusion and DEVDase activity assays. Gene and protein expression changes were assessed by RT-PCR and western blot. Results: ATO induced an antioxidant response characterised by Nrf2 nuclear translocation and enhanced transcription of downstream target genes (that is, HO-1, NQO1, GCLM, ferritin). In cells exposed to ATO plus ATRA, the Nrf2 nuclear translocation was prevented and cytotoxicity was enhanced. HO-1 overexpression reversed partially the cytotoxicity by ATRA-ATO in HL60 cells. The inhibitory effects of ATRA on ATO-mediated responses were not observed in either the ATRA-resistant NB4-R2 cells or in NB4 cells pre-incubated with the RARα antagonist Ro-41-52-53. Conclusions: The augmented cytotoxicity observed in leukaemia cells following combined ATO-ATRA treatment is likely due to inhibition of Nrf2 activity, thus explaining the efficacy of combined ATO-ATRA treatment in the APL therapy. PMID:25003661

  17. Retinoic acid induced growth arrest of human breast carcinoma cells requires protein kinase C alpha expression and activity.

    PubMed

    Cho, Y; Tighe, A P; Talmage, D A

    1997-09-01

    Retinoic acid inhibits proliferation of hormone-dependent, but not hormone-independent breast cancer cells. Retinoic acid-induced changes in cellular proliferation and differentiation are associated with disturbances in growth factor signaling and frequently with changes in protein kinase C expression. PKC delta, epsilon, and zeta are expressed in both hormone-dependent (T-47D) and hormone-independent (MDA-MB-231) cell lines. Retinoic acid arrested T-47D proliferation, induced PKC alpha expression and concomitantly repressed PKC zeta expression. The changes in PKC alpha and PKC zeta reflect retinoic acid-induced changes in mRNA. In contrast, retinoic acid had no effect on growth, or PKC expression in MDA-MB-231 cells. Growth arrest and the induction of PKC alpha, but not the reduction in PKC zeta, resulted from selective activation of RAR alpha. In total, these results support an important role for PKC alpha in mediating the anti-proliferative action of retinoids on human breast carcinoma cells.

  18. Inhibition of activation-induced apoptosis of thymocytes by all-trans- and 9-cis-retinoic acid is mediated via retinoic acid receptor alpha.

    PubMed

    Szondy, Z; Reichert, U; Bernardon, J M; Michel, S; Tóth, R; Karászi, E; Fésüs, L

    1998-05-01

    Thymocytes can be induced to undergo apoptotic cell death by activation through the T-cell receptor (TCR). This process requires macromolecular synthesis and has been shown to be inhibited by retinoic acids (RAs). Two groups of nuclear receptors for RAs have been identified: retinoic acid receptors (RARs) and retinoid X receptors (RXRs). All-trans-RA is the high-affinity ligand for RARs, and 9-cis-RA additionally binds to RXRs with high affinity. Because 9-cis-RA is much more potent in inhibiting TCR-mediated death than all-trans-RA, it was suggested that RXRs participate in the process. In the present study various synthetic retinoid analogues were used to address this question further. The results presented suggest that the inhibitory effect of RAs on activation-induced death of thymocytes is mediated via RARalpha, because (1) it can be reproduced by various RARalpha analogues both in vitro and in vivo, (2) the effect of RAs can be inhibited by the addition of an RARalpha antagonist, (3) CD4+CD8+thymocytes, which die on TCR stimulation, express RARalpha. Stimulation of RARgamma, in contrast, enhances the activation-induced death of thymocytes and inhibits its prevention by RARalpha stimulation. RXR co-stimulation suspends this inhibitory effect of RARgamma and permits the preventive function of RARalpha on activation-induced death. Our results suggest a complex interaction between the various isoforms of retinoid receptors and demonstrate that low (physiological) concentrations of all-trans-RA do not affect the activation-induced death of thymocytes because the RARalpha-mediated inhibitory and the RARgamma-mediated enhancing pathways are in balance, whereas if 9-cis-RA is formed, additional stimulation of RXRs permits the inhibitory action of RARalpha.

  19. Activation function 2 (AF-2) of retinoic acid receptor and 9-cis retinoic acid receptor: presence of a conserved autonomous constitutive activating domain and influence of the nature of the response element on AF-2 activity.

    PubMed Central

    Durand, B; Saunders, M; Gaudon, C; Roy, B; Losson, R; Chambon, P

    1994-01-01

    A motif essential for the transcriptional activation function 2 (AF-2) present in the E region of retinoic acid receptor (RAR) alpha and 9-cis retinoic acid receptor (RXR) alpha has been characterized as an amphipathic alpha-helix whose main features are conserved between transcriptionally active members of the nuclear receptor superfamily. This conserved motif, which can activate autonomously in the absence of ligand in animal and yeast cells, can be swapped between nuclear receptors without affecting the ligand dependency for activation of transcription, thus indicating that a ligand-dependent conformational change is necessary to reveal the AF-2 activation potential within the E region of the nuclear receptor. Interestingly, we show that the precise nature of the direct repeat response element to which RAR/RXR heterodimers are bound can affect the activity of the AF-2s of the heterodimeric partners, as well as the relative efficiency with which all-trans and 9-cis retinoic acids activate the RAR partner. Images PMID:7957103

  20. Identification of COUP-TFII Orphan Nuclear Receptor as a Retinoic Acid-Activated Receptor

    SciTech Connect

    Kruse, Schoen W; Suino-Powell, Kelly; Zhou, X Edward; Kretschman, Jennifer E; Reynolds, Ross; Vonrhein, Clemens; Xu, Yong; Wang, Liliang; Tsai, Sophia Y; Tsai, Ming-Jer; Xu, H Eric

    2010-01-12

    The chicken ovalbumin upstream promoter-transcription factors (COUP-TFI and II) make up the most conserved subfamily of nuclear receptors that play key roles in angiogenesis, neuronal development, organogenesis, cell fate determination, and metabolic homeostasis. Although the biological functions of COUP-TFs have been studied extensively, little is known of their structural features or aspects of ligand regulation. Here we report the ligand-free 1.48 {angstrom} crystal structure of the human COUP-TFII ligand-binding domain. The structure reveals an autorepressed conformation of the receptor, where helix {alpha}10 is bent into the ligand-binding pocket and the activation function-2 helix is folded into the cofactor binding site, thus preventing the recruitment of coactivators. In contrast, in multiple cell lines, COUP-TFII exhibits constitutive transcriptional activity, which can be further potentiated by nuclear receptor coactivators. Mutations designed to disrupt cofactor binding, dimerization, and ligand binding, substantially reduce the COUP-TFII transcriptional activity. Importantly, retinoid acids are able to promote COUP-TFII to recruit coactivators and activate a COUP-TF reporter construct. Although the concentration needed is higher than the physiological levels of retinoic acids, these findings demonstrate that COUP-TFII is a ligand-regulated nuclear receptor, in which ligands activate the receptor by releasing it from the autorepressed conformation.

  1. 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…

  2. Metabolic characteristics of 13-cis-retinoic acid (isotretinoin) and anti-tumour activity of the 13-cis-retinoic acid metabolite 4-oxo-13-cis-retinoic acid in neuroblastoma

    PubMed Central

    Sonawane, Poonam; Cho, Hwang Eui; Tagde, Ashujit; Verlekar, Dattesh; Yu, Alice L; Reynolds, C Patrick; Kang, Min H

    2014-01-01

    Background and Purpose Isotretinoin (13-cis-retinoic acid; 13-cRA) is a differentiation inducer used to treat minimal residual disease after myeloablative therapy for high-risk neuroblastoma. However, more than 40% of children develop recurrent disease during or after 13-cRA treatment. The plasma concentrations of 13-cRA in earlier studies were considered subtherapeutic while 4-oxo-13-cis-RA (4-oxo-13-cRA), a metabolite of 13-cRA considered by some investigators as inactive, were greater than threefold higher than 13-cRA. We sought to define the metabolic pathways of 13-cRA and investigated the anti-tumour activity of its major metabolite, 4-oxo-13-cRA. Experimental Approach Effects of 13-cRA and 4-oxo-13-cRA on human neuroblastoma cell lines were assessed by DIMSCAN and flow cytometry for cell proliferation, MYCN down-regulation by reverse transcription PCR and immunoblotting, and neurite outgrowth by confocal microscopy. 13-cRA metabolism was determined using tandem MS in human liver microsomes and in patient samples. Key Results Six major metabolites of 13-cRA were identified in patient samples. Of these, 4-oxo-13-cRA was the most abundant, and 4-oxo-13-cRA glucuronide was also detected at a higher level in patients. CYP3A4 was shown to play a major role in catalysing 13-cRA to 4-oxo-13-cRA. In human neuroblastoma cell lines, 4-oxo-13-cRA and 13-cRA were equi-effective at inducing neurite outgrowth, inhibiting proliferation, decreasing MYCN mRNA and protein, and increasing the expression of retinoic acid receptor-β mRNA and protein levels. Conclusions and Implications We showed that 4-oxo-13-cRA is as active as 13-cRA against neuroblastoma cell lines. Plasma levels of both 13-cRA and 4-oxo-13-cRA should be evaluated in pharmacokinetic studies of isotretinoin in neuroblastoma. PMID:25039756

  3. All-trans retinoic acid negatively regulates cytotoxic activities of nature killer cell line 92

    SciTech Connect

    Li Ang . E-mail: liang3829@sina.com.cn; He Meilan; Wang Hui; Qiao Bin; Chen Ping; Gu Hua; Zhang Mengjie; He Shengxiang

    2007-01-05

    NK cells are key components of innate immune systems and their activities are regulated by cytokines and hormones. All-trans retinoic acid (ATRA), as a metabolite of vitamin A and an immunomodulatory hormone, plays an important role in regulating immune responses. In the present study, we investigated the effect of ATRA on human NK cell line NK92. We found that ATRA dose-dependently suppressed cytotoxic activities of NK92 cells without affecting their proliferation. To explore the mechanisms underlying the ATRA influence on NK92 cells, we examined the production of cytokines (TNF-{alpha}, IFN-{gamma}), gene expression of cytotoxic-associated molecules (perforin, granzyme B, nature killer receptors (NCRs), and NKG2D), and the activation of NF-{kappa}B pathways related with immune response. Our results demonstrated that ATRA suppressed NF-{kappa}B activity and prevented I{kappa}B{alpha} degradation in a dose-dependent way, inhibited IFN-{gamma} production and gene expression of granzyme B and NKp46. Our findings suggest that ATRA is a negative regulator of NK92 cell activation and may act as a potential regulator of anti-inflammatory functions in vivo.

  4. PLZF is a negative regulator of retinoic acid receptor transcriptional activity.

    PubMed

    Martin, Perrine J; Delmotte, Marie-Hélène; Formstecher, Pierre; Lefebvre, Philippe

    2003-09-01

    BACKGROUND: Retinoic acid receptors (RARs) are ligand-regulated transcription factors controlling cellular proliferation and differentiation. Receptor-interacting proteins such as corepressors and coactivators play a crucial role in specifying the overall transcriptional activity of the receptor in response to ligand treatment. Little is known however on how receptor activity is controlled by intermediary factors which interact with RARs in a ligand-independent manner. RESULTS: We have identified the promyelocytic leukemia zinc finger protein (PLZF), a transcriptional corepressor, to be a RAR-interacting protein using the yeast two-hybrid assay. We confirmed this interaction by GST-pull down assays and show that the PLZF N-terminal zinc finger domain is necessary and sufficient for PLZF to bind RAR. The RAR ligand binding domain displayed the highest affinity for PLZF, but corepressor and coactivator binding interfaces did not contribute to PLZF recruitment. The interaction was ligand-independent and correlated to a decreased transcriptional activity of the RXR-RAR heterodimer upon overexpression of PLZF. A similar transcriptional interference could be observed with the estrogen receptor alpha and the glucocorticoid receptor. We further show that PLZF is likely to act by preventing RXR-RAR heterodimerization, both in-vitro and in intact cells. CONCLUSION: Thus RAR and PLZF interact physically and functionally. Intriguingly, these two transcription factors play a determining role in hematopoiesis and regionalization of the hindbrain and may, upon chromosomal translocation, form fusion proteins. Our observations therefore define a novel mechanism by which RARs activity may be controlled.

  5. Running increases neurogenesis without retinoic acid receptor activation in the adult mouse dentate gyrus.

    PubMed

    Aberg, Elin; Perlmann, Thomas; Olson, Lars; Brené, Stefan

    2008-01-01

    Both vitamin A deficiency and high doses of retinoids can result in learning and memory impairments, depression as well as decreases in cell proliferation, neurogenesis and cell survival. Physical activity enhances hippocampal neurogenesis and can also exert an antidepressant effect. Here we elucidate a putative link between running, retinoid signaling, and neurogenesis in hippocampus. Adult transgenic reporter mice designed to detect ligand-activated retinoic acid receptors (RAR) or retinoid X receptors (RXR) were used to localize the distribution of activated RAR or RXR at the single-cell level in the brain. Two months of voluntary wheel-running induced an increase in hippocampal neurogenesis as indicated by an almost two-fold increase in doublecortin-immunoreactive cells. Running activity was correlated with neurogenesis. Under basal conditions a distinct pattern of RAR-activated cells was detected in the granule cell layer of the dentate gyrus (DG), thalamus, and cerebral cortex layers 3-4 and to a lesser extent in hippocampal pyramidal cell layers CA1-CA3. Running did not change the number of RAR-activated cells in the DG. There was no correlation between running and RAR activation or between RAR activation and neurogenesis in the DG of hippocampus. Only a few scattered activated retinoid X receptors were found in the DG under basal conditions and after wheel-running, but RXR was detected in other areas such as in the hilus region of hippocampus and in layer VI of cortex cerebri. RAR agonists affect mood in humans and reduce neurogenesis, learning and memory in animal models. In our study, long-term running increased neurogenesis but did not alter RAR ligand activation in the DG in individually housed mice. Thus, our data suggest that the effects of exercise on neurogenesis and other plasticity changes in the hippocampal formation are mediated by mechanisms that do not involve retinoid receptor activation.

  6. SV40 enhancer activation during retinoic acid-induced differentiation of F9 embryonal carcinoma cells.

    PubMed Central

    Sleigh, M J; Lockett, T J

    1985-01-01

    The transient expression vector pSV2CAT, which carries the bacterial chloramphenicol acetyl transferase (CAT) gene under the control of the SV40 early promoter, was used to transfect the murine embryonal carcinoma cell line F9 at various times during the retinoic acid-induced differentiation of these cells. Expression of the CAT gene under SV40 promoter control was found to increase markedly on F9 cell differentiation, measured relative to expression from the thymidine kinase promoter in the same cells. A series of constructs was prepared to identify the features of the SV40 early promoter required for transcription in differentiated and undifferentiated cells, as well as the factors limiting transcription in each case. The increased transcription seen on F9 cell differentiation was not observed when cells were transfected with molecules lacking a functional enhancer. It appears that as embryonal carcinoma cells differentiate, increased SV40 transcription results from enhancer sequence activation. In both differentiated and undifferentiated cell types the level of transcription was found to be limited by the availability and/or activity of cellular factors necessary for enhancer function. Images Fig. 1. PMID:3004973

  7. PLZF is a negative regulator of retinoic acid receptor transcriptional activity

    PubMed Central

    Martin, Perrine J; Delmotte, Marie-Hélène; Formstecher, Pierre; Lefebvre, Philippe

    2003-01-01

    Background Retinoic acid receptors (RARs) are ligand-regulated transcription factors controlling cellular proliferation and differentiation. Receptor-interacting proteins such as corepressors and coactivators play a crucial role in specifying the overall transcriptional activity of the receptor in response to ligand treatment. Little is known however on how receptor activity is controlled by intermediary factors which interact with RARs in a ligand-independent manner. Results We have identified the promyelocytic leukemia zinc finger protein (PLZF), a transcriptional corepressor, to be a RAR-interacting protein using the yeast two-hybrid assay. We confirmed this interaction by GST-pull down assays and show that the PLZF N-terminal zinc finger domain is necessary and sufficient for PLZF to bind RAR. The RAR ligand binding domain displayed the highest affinity for PLZF, but corepressor and coactivator binding interfaces did not contribute to PLZF recruitment. The interaction was ligand-independent and correlated to a decreased transcriptional activity of the RXR-RAR heterodimer upon overexpression of PLZF. A similar transcriptional interference could be observed with the estrogen receptor alpha and the glucocorticoid receptor. We further show that PLZF is likely to act by preventing RXR-RAR heterodimerization, both in-vitro and in intact cells. Conclusion Thus RAR and PLZF interact physically and functionally. Intriguingly, these two transcription factors play a determining role in hematopoiesis and regionalization of the hindbrain and may, upon chromosomal translocation, form fusion proteins. Our observations therefore define a novel mechanism by which RARs activity may be controlled. PMID:14521715

  8. Shifting boundaries of retinoic acid activity control hindbrain segmental gene expression.

    PubMed

    Sirbu, Ioan Ovidiu; Gresh, Lionel; Barra, Jacqueline; Duester, Gregg

    2005-06-01

    Retinoic acid (RA) generated by Raldh2 in paraxial mesoderm is required for specification of the posterior hindbrain, including restriction of Hoxb1 expression to presumptive rhombomere 4 (r4). Hoxb1 expression requires 3' and 5' RA response elements for widespread induction up to r4 and for r3/r5 repression, but RA has previously been detected only from r5-r8, and vHnf1 is required for repression of Hoxb1 posterior to r4 in zebrafish. We demonstrate in mouse embryos that an RA signal initially travels from the paraxial mesoderm to r3, forming a boundary next to the r2 expression domain of Cyp26a1 (which encodes an RA-degrading enzyme). After Hoxb1 induction, the RA boundary quickly shifts to r4/r5, coincident with induction of Cyp26c1 in r4. A functional role for Cyp26c1 in RA degradation was established through examination of RA-treated embryos. Analysis of Raldh2-/- and vHnf1-/- embryos supports a direct role for RA in Hoxb1 induction up to r4 and repression in r3/r5, as well as an indirect role for RA in Hoxb1 repression posterior to r4 via RA induction of vHnf1 up to the r4/r5 boundary. Our findings suggest that Raldh2 and Cyp26 generate shifting boundaries of RA activity, such that r3-r4 receives a short pulse of RA and r5-r8 receives a long pulse of RA. These two pulses of RA activity function to establish expression of Hoxb1 and vHnf1 on opposite sides of the r4/r5 boundary.

  9. Spatiotemporal manipulation of retinoic acid activity in zebrafish hindbrain development via photo-isomerization.

    PubMed

    Xu, Lijun; Feng, Zhiping; Sinha, Deepak; Ducos, Bertrand; Ebenstein, Yuval; Tadmor, Arbel D; Gauron, Carole; Le Saux, Thomas; Lin, Shuo; Weiss, Shimon; Vriz, Sophie; Jullien, Ludovic; Bensimon, David

    2012-09-01

    All-trans retinoic acid (RA) is a key player in many developmental pathways. Most methods used to study its effects in development involve continuous all-trans RA activation by incubation in a solution of all-trans RA or by implanting all-trans RA-soaked beads at desired locations in the embryo. Here we show that the UV-driven photo-isomerization of 13-cis RA to the trans-isomer (and vice versa) can be used to non-invasively and quantitatively control the concentration of all-trans RA in a developing embryo in time and space. This facilitates the global or local perturbation of developmental pathways with a pulse of all-trans RA of known concentration or its inactivation by UV illumination. In zebrafish embryos in which endogenous synthesis of all-trans RA is impaired, incubation for as little as 5 minutes in 1 nM all-trans RA (a pulse) or 5 nM 13-cis RA followed by 1-minute UV illumination is sufficient to rescue the development of the hindbrain if performed no later than bud stage. However, if subsequent to this all-trans RA pulse the embryo is illuminated (no later than bud stage) for 1 minute with UV light (to isomerize, i.e. deactivate, all-trans RA), the rescue of hindbrain development is impaired. This suggests that all-trans RA is sequestered in embryos that have been transiently exposed to it. Using 13-cis RA isomerization with UV light, we further show that local illumination at bud stage of the head region (but not the tail) is sufficient to rescue hindbrain formation in embryos whose all-trans RA synthetic pathway has been impaired. PMID:22874920

  10. Retinoic acid-mediated gene expression in transgenic reporter zebrafish.

    PubMed

    Perz-Edwards, A; Hardison, N L; Linney, E

    2001-01-01

    Retinoic acid-mediated gene activation is important for normal vertebrate development. The size and nature of retinoic acid make it difficult to identify the precise cellular location of this signaling molecule throughout an embryo. Additionally, retinoic acid (RA) signaling is regulated by a complex combination of receptors, coactivators, and antagonizing proteins. Thus, in order to integrate these signals and identify regions within a whole developing embryo where cells can respond transcriptionally to retinoic acid, we have used a reporter transgenic approach. We have generated several stable lines of transgenic zebrafish which use retinoic acid response elements to drive fluorescent protein expression. In these zebrafish lines, transgene expression is localized to regions of the neural tube, retina, notochord, somites, heart, pronephric ducts, branchial arches, and jaw muscles in embryos and larvae. Transgene expression can be induced in additional regions of the neural tube and retina as well as the immature notochord, hatching gland, enveloping cell layer, and fin by exposing embryos to retinoic acid. Treatment with retinoic acid synthase inhibitors, citral and diethylaminobenzaldehyde (DEAB), during neurulation, greatly reduces transgene expression. DEAB treatment of embryos at gastrulation phenocopies the embryonic effects of vitamin A deprivation or targeted disruption of the RA synthase retinaldehyde dehydrogenase-2 in other vertebrates. Together these data suggest that the reporter expression we see in zebrafish is dependent upon conserved vertebrate pathways of RA synthesis.

  11. Retinoic acid receptors and GATA transcription factors activate the transcription of the human lecithin:retinol acyltransferase gene

    PubMed Central

    Cai, Kun; Gudas, Lorraine J.

    2008-01-01

    Lecithin retinol acyltransferase (LRAT) catalyzes the esterification of retinol (vitamin A). Retinyl esters and LRAT protein levels are reduced in many types of cancer cells. We present data that both the LRAT and retinoic acid receptor β2 (RARβ2) mRNA levels in the human prostate cancer cell line PC-3 are lower than those in cultured normal human prostate epithelial cells (PrEC). The activity of the human LRAT promoter (2.0 kb) driving a luciferase reporter gene in PC-3 cells is less than 40% of that in PrEC cells. Retinoic acid (RA) treatment increased this LRAT promoter-luciferase activity in PrEC cells, but not in PC-3 cells. Deletion of various regions of the human LRAT promoter demonstrated that a 172-bp proximal promoter region is essential for LRAT transcription and confers RA responsiveness in PrEC cells. This 172-bp region, contained within the 186 bp pLRAT/luciferase construct, has five putative GATA binding sites. Co-transfection of RARβ2 or RARγ and the transcription factor GATA-4 increased LRAT (pLRAT186) promoter activity in both PrEC and PC-3 cells. In addition, we found that both retinoic acid and retinol induced transcripts for the STRA6 gene, which encodes a membrane receptor involved in retinol (vitamin A) uptake, in PrEC cells but not in PC-3 cells. In summary, our data show that the transcriptional regulation of the human LRAT gene is aberrant in human prostate cancer cells and that GATA transcription factors are involved in the transcriptional activation of LRAT in PrEC cells. PMID:18652909

  12. Activation of RAS/ERK alone is insufficient to inhibit RXRα function and deplete retinoic acid in hepatocytes

    SciTech Connect

    Wang, Ai-Guo Song, Ya-Nan; Chen, Jun; Li, Hui-Ling; Dong, Jian-Yi; Cui, Hai-Peng; Yao, Liang; Li, Xue-Feng; Gao, Wen-Ting; Qiu, Ze-Wen; Wang, Fu-Jin; Wang, Jing-Yu

    2014-09-26

    Highlights: • The activation of RAS/ERK is insufficient to inhibit RXRα function and deplete RA. • The retinoid metabolism-related genes are down-regulated by ras oncogene. • The atRA has no effect on preventing hepatic tumorigenesis or curing the developed hepatic nodules. - Abstract: Activation of RAS/ERK signaling pathway, depletion of retinoid, and phosphorylation of retinoid X receptor alpha (RXRα) are frequent events found in liver tumors and thought to play important roles in hepatic tumorigenesis. However, the relationships among them still remained to be elucidated. By exploring the transgenic mouse model of hepatic tumorigenesis induced by liver-specific expression of H-ras12V oncogene, the activation of RAS/ERK, the mRNA expression levels of retinoid metabolism-related genes, the contents of retinoid metabolites, and phosphorylation of RXRα were determined. RAS/ERK signaling pathway was gradually and significantly activated in hepatic tumor adjacent normal liver tissues (P) and hepatic tumor tissues (T) of H-ras12V transgenic mice compared with normal liver tissues (Wt) of wild type mice. On the contrary, the mRNA expression levels of retinoid metabolism-related genes were significantly reduced in P and T compared with Wt. Interestingly, the retinoid metabolites 9-cis-retinoic acid (9cRA) and all-trans-retinoic acid (atRA), the well known ligands for nuclear transcription factor RXR and retinoic acid receptor (RAR), were significantly decreased only in T compared with Wt and P, although the oxidized polar metabolite of atRA, 4-keto-all-trans-retinoic-acid (4-keto-RA) was significantly decreased in both P and T compared with Wt. To our surprise, the functions of RXRα were significantly blocked only in T compared with Wt and P. Namely, the total protein levels of RXRα were significantly reduced and the phosphorylation levels of RXRα were significantly increased only in T compared with Wt and P. Treatment of H-ras12V transgenic mice at 5-week

  13. All trans-retinoic acid modulates the procoagulant activity of human breast cancer cells.

    PubMed

    Marchetti, Marina; Russo, Laura; Balducci, Donatella; Falanga, Anna

    2011-10-01

    All trans-retinoic acid (ATRA) induces apoptosis and/or differentiation in solid tumors, including breast cancer, and has become a therapeutic tool in this disease. In human promyelocytic leukemia ATRA reduces the expression of cellular procoagulant activities (PCA), i.e. tissue factor (TF) and cancer procoagulant (CP). There are no studies on the effects of ATRA on the PCA of solid tumors, i.e. breast cancer cells. We analyzed different human breast cancer cell lines in order to: 1. characterize the expression of TF and CP; 2. evaluate whether these activities are affected by ATRA; and 3. verify whether a reduction in tumor cell procoagulants may occur in association to apoptosis and growth inhibition induced by ATRA. Two estrogen receptor positive (ER-positive; i.e. MCF7 and ZR75.1) and one estrogen receptor negative (ER-negative; i.e. MDA.MB.231) cell lines were included into the study. The results show that ATRA affected TF in a dose-dependent fashion only in ER-positive cell lines. In particular, at 1 uM ATRA, TF significantly (p < 0.05) decreased by 57%, 44% in MCF7, ZR75.1 cells, respectively. Differently the results show that ATRA dose-dependently affected CP expression in all three cell lines. Specifically, at 1 uM ATRA, CP significantly decreased by 44%, 50% and 25% in MCF7, ZR75.1, and MDA.MB.231. Only in ER-positive cell lines, there was a dose-dependent inhibition of cell growth that became statistically significant at 1 uM ATRA, which was associated to a slight but significant increase in the percentage of apoptotic cells. In conclusion, this study demonstrates for the first time that ATRA downregulates the expression of TF and CP in breast cancer cells. Due to the pivotal role of coagulation activation in tumor progression, the capacity of ATRA to affect also tumor procoagulants, in parallel to cell apoptosis, open new perspectives in tumor therapy.

  14. Enhancement of the inducible NO synthase activation by retinoic acid is mimicked by RARalpha agonist in vivo.

    PubMed

    Seguin-Devaux, Carole; Devaux, Yvan; Latger-Cannard, Véronique; Grosjean, Sandrine; Rochette-Egly, Cécile; Zannad, Faiez; Meistelman, Claude; Mertes, Paul-Michel; Longrois, Dan

    2002-09-01

    We have previously shown that all-trans retinoic acid (atRA), the active metabolite of vitamin A, enhances the activation of the inducible nitric oxide synthase (NOS II) pathway, a component of innate immunity, in rats in vivo. We investigated the relative contribution of retinoic acid receptor-alpha (RARalpha) and retinoid X receptors (RXRs) to NOS II activation triggered by LPS. Five-day supplementation with 10 mg/kg of either atRA or the RARalpha selective agonist Ro-40-6055, but not with 10 mg/kg of the pan-RXR agonist Ro-25-7386, enhanced the LPS-induced NOS II mRNA, protein expression in liver, and plasma nitrite/nitrate concentration. Both atRA and the RARalpha agonist (but not the RXR agonist) increased the number of peripheral T helper lymphocytes and plasma interferon-gamma concentration. Synergism between retinoids and LPS on NOS II activation within an organ coincided with synergism on interferon regulatory factor-1 mRNA expression but not with the level of expression of the RARalpha protein. These results suggest that, in vivo, atRA activates NOS II through RARalpha and contributes to characterizing the complex effect of retinoids on the host inflammatory/immune response.

  15. 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

  16. Retinoic acid suppresses the canonical Wnt signaling pathway in embryonic stem cells and activates the noncanonical Wnt signaling pathway

    PubMed Central

    Osei-Sarfo, Kwame; Gudas, Lorraine J.

    2014-01-01

    Embryonic stem cells (ESCs) have both the ability to self-renew and to differentiate into various cell lineages. Retinoic acid (RA), a metabolite of Vitamin A, has a critical function in initiating lineage differentiation of ESCs through binding to the retinoic acid receptors (RARs). Additionally, the Wnt signaling pathway plays a role in pluripotency and differentiation, depending on the activation status of the canonical and noncanonical pathways. The activation of the canonical Wnt signaling pathway, which requires the nuclear accumulation of β-catenin and its interaction with Tcf1/Lef at Wnt response elements, is involved in ESC stemness maintenance. The noncanonical Wnt signaling pathway, through actions of Tcf3, can antagonize the canonical pathway. We show that RA activates the noncanonical Wnt signaling pathway, while concomitantly inhibiting the canonical pathway. RA increases the expression of ligands and receptors of the noncanonical Wnt pathway (Wnt 5a, 7a, Fzd2 and Fzd6), downstream signaling, and Tcf3 expression. RA reduces the phosphorylated β-catenin level by 4-fold, though total β-catenin levels don't change. We show that RA signaling increases the dissociation of Tcf1 and the association of Tcf3 at promoters of genes that regulate stemness (e.g. NR5A2,Lrh-1) or differentiation (eg. Cyr61, Zic5). Knockdown of Tcf3 increases Lrh-1 transcript levels in mESCs and prevents the RA-associated, ∼4-fold increase in Zic5, indicating that RA requires Tcf3 to effect changes in Zic5 levels. We demonstrate a novel role for RA in altering the activation of these two Wnt signaling pathways and show that Tcf3 mediates some actions of RA during differentiation. PMID:24648413

  17. Loss of growth inhibitory effects of retinoic acid in human breast cancer cells following long-term exposure to retinoic acid

    PubMed Central

    Stephen, R; Darbre, P D

    2000-01-01

    Although retinoids are known to be inhibitory to breast cancer cell growth, a key remaining question is whether they would remain effective if administered long-term. We describe here the long-term effects of all-trans retinoic acid on two oestrogen-dependent human breast cancer cell lines MCF7 and ZR-75-1. Although both cell lines were growth inhibited by retinoic acid in the short-term in either the absence or the presence of oestradiol, prolonged culture with 1 μM all-trans retinoic acid resulted in the cells acquiring resistance to the growth inhibitory effects of retinoic acid. Time courses showed that oestrogen deprivation of the cell lines resulted in upregulation of the basal non-oestrogen stimulated growth rate such that cells learned to grow at the same rate without as with oestradiol, but the cells remained growth inhibited by retinoic acid throughout. Addition of 1 μM all-trans retinoic acid to steroid deprivation conditions resulted in reproducible loss of growth response to both retinoic acid and oestradiol, although the time courses were separable in that loss of growth response to retinoic acid preceded that of oestradiol. Loss of growth response to retinoic acid did not involve loss of receptors, ER as measured by steroid binding assay or RARα as measured by Northern blotting. Function of the receptors was retained in terms of the ability of both oestradiol and retinoic acid to upregulate pS2 gene expression, but there was reduced ability to upregulate transiently transfected ERE- and RRE-linked reporter genes. Despite the accepted role of IGFBP3 in retinoic acid-mediated growth inhibition, progression to retinoic acid resistance occurred irrespective of level of IGFBP3, which remained high in the resistant MCF7 cells. Measurement of AP1 activity showed that the two cell lines had markedly different basal AP1 activities, but that progression to resistance was accompanied in both cases by a lost ability of retinoic acid to reduce AP1 activity

  18. 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

  19. A transition in transcriptional activation by the glucocorticoid and retinoic acid receptors at the tumor stage of dermal fibrosarcoma development.

    PubMed Central

    Vivanco, M D; Johnson, R; Galante, P E; Hanahan, D; Yamamoto, K R

    1995-01-01

    In transgenic mice harboring the bovine papillomavirus genome, fibrosarcomas arise along an experimentally accessible pathway in which normal dermal fibroblasts progress through two pre-neoplastic stages, mild and aggressive fibromatosis, followed by a final transition to the tumor stage. We found that the glucocorticoid receptor (GR) displays only modest transcriptional regulatory activity in cells derived from the three non-tumor stages, whereas it is highly active in fibrosarcoma cells. Upon inoculation into mice, the aggressive fibromatosis cells progress to tumor cells that have high GR activity; thus, the increased transcriptional regulatory activity of GR correlates with the cellular transition to the tumor stage. The intracellular levels of GR, as well as its hormone-dependent nuclear translocation and specific DNA binding activities, are unaltered throughout the progression. Strikingly, the low GR activity observed in the pre-neoplastic stages cannot be overcome by exogenous GR introduced by co-transfection. Moreover, comparisons of primary embryo fibroblasts and their transformed derivatives revealed a similar pattern--modest GR activity, unresponsive to overexpressed GR protein, in the normal cells was strongly increased in the transformed cells. Likewise, the retinoic acid receptor (RAR) displayed similar differential activity in the fibrosarcoma pathway. Thus, the oncogenic transformation of fibroblasts, and likely other cell types, is accompanied by a striking increase in the activities of transcriptional regulators such as GR and RAR. We suggest that normal primary cells have a heretofore unrecognized capability to limit the magnitude of induction of gene expression. Images PMID:7774580

  20. Nanostructured lipid carriers loaded with tributyrin as an alternative to improve anticancer activity of all-trans retinoic acid

    PubMed Central

    Silva, Elton Luiz; Carneiro, Guilherme; Caetano, Priscila Albuquerque; Costa, Daniel Ferreira; de Souza-Fagundes, Elaine Maria; Gomes, Dawidson Assis; Ferreira, Lucas Antônio Miranda

    2015-01-01

    Objectives All-trans retinoic acid (ATRA) is one of the most successful examples of differentiation agents and histone deacetylase inhibitors, such as tributyrin (TB), are known for their antitumor activity and potentiating action of drugs such as ATRA. Nanostructured lipid carriers (NLC) represent a promising alternative to the encapsulation of lipophilic drugs such as ATRA. This study aimed to develop, characterize, and evaluate the cytotoxicity of ATRA-TB-loaded nanostructured lipid carriers (NLC) for cancer treatment. Methods The influence of in situ formation of an ion pairing between ATRA and a lipophilic amine (benethamine; BNT) on the characteristics of NLC (size, zeta potential, encapsulation efficiency) was evaluated. Tributyrin (TB), a butyric acid donor, was used as a component of the lipid matrix. In vitro activity on cell viability and distribution of cell cycle phases were evaluated for MCF-7, MDA-MB-231, HL-60, and Jurkat cell lines. Results The presence of the amine significantly increased the encapsulation efficiency of ATRA in NLC. Inhibition of cell viability by TB-ATRA-loaded NLC was more pronounced than the free drug. Analysis of the distribution of cell cycle phases also showed increased activity for TB-ATRA-loaded NLC, with the clear effect of cell cycle arrest in G0/G1 phase transition. The presence of TB played an important role in the activity of the formulation. Conclusion Taken together, these findings suggest that TB-ATRA-loaded NLC represent a promising alternative to intravenous administration of ATRA in cancer treatment. PMID:25611812

  1. 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

  2. All-trans-retinoic acid nanodisks.

    PubMed

    Redmond, Katherine A; Nguyen, Thanh-Son; Ryan, Robert O

    2007-07-18

    Nanodisks are nanoscale, disk-shaped phospholipid bilayers whose edge is stabilized by association of apolipoprotein molecules. Self-assembled ND particles enriched with all-trans-retinoic acid (ATRA) (phospholipid:ATRA molar ratio = 5.5:1) were generated wherein all reaction components were solubilized. ATRA-ND migrated as a single band (Stokes' diameter approximately 20 nm) on native gradient polyacrylamide gel electrophoresis. ATRA, phospholipid and apolipoprotein co-eluted from a Sepharose 6B gel filtration column, consistent with stable integration of ATRA into the ND particle milieu. Spectroscopic analysis of ATRA-ND in buffer yielded an absorbance spectrum characteristic of ATRA. ATRA-ND mediated time-dependent inhibition of cultured HepG2 cell growth more effectively than free ATRA. The nanoscale size of the formulation particles and the stable integration of biologically active ATRA suggest ND represent a potentially useful vehicle for solubilization and in vivo delivery of ATRA.

  3. Formation of retinoic acid from retinol in the rat

    PubMed Central

    Emerick, R. J.; Zile, Maija; DeLuca, H. F.

    1967-01-01

    1. The formation in vivo of retinoic acid from microgram quantities of intrajugularly administered [15-14C]retinol was demonstrated in the rat. 2. Endogenously formed retinoic acid (about 0·1μg./rat) was found in liver, and to a much smaller extent in intestine, 12hr. after retinol administration. 3. Excretion of some of the endogenously formed retinoic acid occurred in the bile of bile-duct-cannulated rats. 4. Excretion of unaltered retinoic acid in the urine of intact rats did not occur even after the intrajugular administration of preformed retinoic acid. PMID:6029617

  4. Active Pin1 is a key target of all-trans retinoic acid in acute promyelocytic leukemia and breast cancer

    PubMed Central

    Wei, Shuo; Kozono, Shingo; Kats, Lev; Nechama, Morris; Li, Wenzong; Guarnerio, Jlenia; Luo, Manli; You, Mi-Hyeon; Yao, Yandan; Kondo, Asami; Hu, Hai; Bozkurt, Gunes; Moerke, Nathan J.; Cao, Shugeng; Reschke, Markus; Chen, Chun-Hau; Rego, Eduardo M.; LoCoco, Francesco; Cantley, Lewis; Lee, Tae Ho; Wu, Hao; Zhang, Yan; Pandolfi, Pier Paolo; Zhou, Xiao Zhen; Lu, Kun Ping

    2015-01-01

    A common key regulator of oncogenic signaling pathways in multiple tumor types is the unique isomerase Pin1. However, available Pin1 inhibitors lack the required specificity and potency. Using mechanism-based screening, here we find that all-trans retinoic acid (ATRA)--a therapy for acute promyelocytic leukemia (APL) that is considered the first example of targeted therapy in cancer, but its drug target remains elusive--inhibits and degrades active Pin1 selectively in cancer cells by directly binding to the substrate phosphate- and proline-binding pockets in the Pin1 active site. ATRA-induced Pin1 ablation degrades the fusion oncogene PML-RARα and treats APL in cell and animal models and human patients. ATRA-induced Pin1 ablation also inhibits triple negative breast cancer cell growth in human cells and in animal models by acting on many Pin1 substrate oncogenes and tumor suppressors. Thus, ATRA simultaneously blocks multiple Pin1-regulated cancer-driving pathways, an attractive property for treating aggressive and drug-resistant tumors. PMID:25849135

  5. A Comparison of the Roles of Peroxisome Proliferator-Activated Receptor and Retinoic Acid Receptor on CYP26 Regulation

    PubMed Central

    Tay, Suzanne; Dickmann, Leslie; Dixit, Vaishali

    2010-01-01

    The cytochrome P450 26 family is believed to be responsible for all-trans-retinoic acid (atRA) metabolism and elimination in the human fetus and adults. CYP26A1 and CYP26B1 mRNA is expressed in a tissue-specific manner, and mice in which the CPY26 isoform has been knocked out show distinct malformations and lethality. The aim of this study was to determine differences in CYP26A1 and CYP26B1 regulation and expression. Analysis of CYP26A1 and CYP26B1 expression in a panel of 57 human livers showed CYP26A1 to be the major CYP26 isoform present in the liver, and its expression to be subject to large interindividual variability between donors. CYP26A1 and retinoic acid receptor (RAR) β were found to be greatly inducible by atRA in HepG2 cells, whereas CYP26B1, RARα, and RARγ were induced to a much lesser extent. Based on treatments with RAR isoform-selective ligands, RARα is the major isoform responsible for CYP26A1 and RARβ induction in HepG2 cells. Classic cytochrome P450 inducers did not affect CYP26 transcription, whereas the peroxisome proliferator-activated receptor (PPAR) γ agonists pioglitazone and rosiglitazone up-regulated CYP26B1 transcription by as much as 209- ± 80-fold and CYP26A1 by 10-fold. RARβ was also up-regulated by pioglitazone and rosiglitazone. CYP26B1 induction by PPARγ agonists was abolished by the irreversible PPARγ antagonist 2-chloro-5-nitrobenzanilide (GW9662), whereas RARβ and CYP26A1 induction was unaffected by GW9662. Overall, the results of this study suggest that CYP26B1 and CYP26A1 are regulated by different nuclear receptors, resulting in tissue-specific expression patterns. The fact that drugs can alter the expression of CYP26 enzymes may have toxicological and therapeutic importance. PMID:19884280

  6. Inhibition of all-trans-retinoic acid-induced proteasome activation potentiates the differentiating effect of retinoid in acute myeloid leukemia cells.

    PubMed

    Fang, Yanfen; Zhou, Xinglu; Lin, Meihua; Ying, Meidan; Luo, Peihua; Zhu, Difeng; Lou, Jianshu; Yang, Bo; He, Qiaojun

    2011-01-01

    All-trans retinoic acid (ATRA) is nowadays considered to be the sole efficient agent for differentiation-based therapy in leukemia; however, the mechanisms of ATRA's biological effects remain largely unknown. Here we first reported that ATRA-induced myeloid leukemia differentiation was accompanied with the increased level of ubiquitin-protein conjugates and the upregulation of proteasome activity. To explore the functional role of the activated proteasome in retinoic acid (RA) signaling, the effects of proteasome inhibitors on RA-induced cell differentiation were determined. Our results demonstrated that inhibition of ATRA-elevated proteasome activity obviously promoted the myeloid maturation program triggered by ATRA, suggesting that the overactivated proteasome is not beneficial for ATRA's effects. Further studies demonstrated that the synergistic differentiating effects of ATRA and proteasome inhibitors might be associated with the protection of retinoic acid receptor alpha (RARα) from degradation by the ubiquitin-proteasome pathway (UPP). Moreover, the accumulated RARα was able to enhance the transcription of its target gene, which might also contribute to the enhanced differentiation of leukemia cells. Together, by linking the UPP to ATRA-dependent signaling, our data provide a novel insight into studying the mechanisms of ATRA-elicited cellular effects and imply the possibility of combination of ATRA and proteasome inhibitors in leukemia therapy.

  7. 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...

  8. Retinoic acid modulation of thyroid dual oxidase activity in rats and its impact on thyroid iodine organification.

    PubMed

    Mühlbauer, Mônica; da Silva, Alba Cenélia Matos; Marassi, Michelle Porto; Lourenço, Alexandre Lopes; Ferreira, Andrea Claudia Freitas; de Carvalho, Denise Pires

    2010-06-01

    The sodium-iodide symporter (NIS) mediates iodide uptake into the thyrocytes, which is important for the diagnosis and therapy of thyroid disorders. Decreased ability to uptake iodide in thyroid carcinomas reduces the efficacy of radioiodine therapy, and retinoic acid (RA) treatment reinduces iodide uptake. The effectiveness of treatment depends not only on iodide uptake but also on the ability of thyrocytes to organify iodine, which is catalyzed by thyroperoxidase (TPO) in the presence of H(2)O(2). Our goal was to determine the influence of RA on thyroid iodide uptake, iodine organification, and TPO and dual oxidase (DuOx) activities. Normal rats were treated with all-trans-RA or 13-cis-RA (100 or 1500 microg/100 g body weight (b.w.), s.c.) for 14 and 28 days. The 2 h thyroid radioiodine content significantly decreased in rats treated with all-trans-RA (100 microg/100 g b.w.) for 14 days. In this group, NIS function and TPO activity were unchanged, whereas DuOx activity was significantly decreased, which might have contributed to the decrease in iodine organification. Both doses of 13-cis-RA for 28 days increased the 15 min thyroid radioiodine uptake, while the 2 h radioiodide uptake increased only in rats treated with the highest dose of 13-cis-RA. While TPO activity did not change, H(2)O(2) generation was increased in this group, and serum thyroxine levels were normal. Since radioiodine half-life in the thyroid gland is important for treatment efficacy, our results highlight the importance of correctly choosing the RA isomer, the time and the dose of treatment, in order to improve the efficacy of radioiodine therapy.

  9. Retinol oxidation to retinoic acid in human thyroid glandular cells.

    PubMed

    Taibi, Gennaro; Gueli, Maria Concetta; Nicotra, Concetta M A; Cocciadiferro, Letizia; Carruba, Giuseppe

    2014-12-01

    Abstract Retinoic acid is regarded as the retinol metabolite that controls proliferation and differentiation of epithelial cells. In the present study, we investigated the potential role of xanthine dehydrogenase (XDH) in retinoic acid biosynthesis in human thyroid glandular cells (HTGC). In particular, we observed that cellular retinoids binding proteins (CRBPs) are also implicated in the biosynthetic pathway leading to retinoic acid formation in primary cultures of HTGC, as we have already reported for human mammary epithelial cells (HMEC). After partial protein purification, the enzyme responsible for retinoic acid biosynthesis was identified and quantified as XDH by immunoassay, by its ability to oxidize xanthine to uric acid and its sensitivity to the inhibitory effect of oxypurinol. The evidence of XDH-driven formation of retinoic acid in HTGC cultures further corroborates the potential role of XDH in retinoic acid biosynthesis in the epithelia. PMID:24506204

  10. Dietary soy protein isolate modifies hepatic retinoic acid receptor-beta proteins and inhibits their DNA binding activity in rats.

    PubMed

    Xiao, Chao Wu; Mei, Jie; Huang, Wenxin; Wood, Carla; L'abbé, Mary R; Gilani, G Sarwar; Cooke, Gerard M; Curran, Ivan H

    2007-01-01

    Retinoic acid receptors (RAR) belong to the same nuclear receptor superfamily as thyroid hormone receptors (TR) that were previously shown to be modulated by dietary soy protein isolate (SPI). This study has examined the effect of dietary SPI and isoflavones (ISF) on hepatic RAR gene expression and DNA binding activity. In Expt. 1, Sprague-Dawley rats were fed diets containing 20% casein or 20% alcohol-washed SPI in the absence or presence of increasing amounts of ISF (5-1250 mg/kg diet) for 70, 190, or 310 d. In Expt. 2, weanling Sprague-Dawley rats were fed diets containing 20% casein with or without supplemental ISF (50 mg/kg diet) or increasing amounts of alcohol-washed SPI (5, 10, and 20%) for 90 d. Intake of soy proteins significantly elevated hepatic RARbeta2 protein content dose-dependently compared with a casein diet, whereas supplemental ISF had no consistent effect. Neither RARbeta protein in the other tissues measured nor the other RAR (RARalpha and RARgamma) in the liver were affected by dietary SPI, indicating a tissue and isoform-specific effect of SPI. RARbeta2 mRNA abundances were not different between dietary groups except that its expression was markedly suppressed in male rats fed SPI for 310 d. DNA binding activity of nuclear RARbeta was significantly attenuated and the isoelectric points of RARbeta2 were shifted by dietary SPI. Overall, these results show for the first time, to our knowledge, that dietary soy proteins affect hepatic RARbeta2 protein content and RARbeta DNA binding activity, which may contribute to the suppression of retinoid-induced hypertriglyceridemia by SPI as reported.

  11. 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

  12. H11-H12 loop retinoic acid receptor mutants exhibit distinct trans-activating and trans-repressing activities in the presence of natural or synthetic retinoids.

    PubMed

    Lefebvre, B; Mouchon, A; Formstecher, P; Lefebvre, P

    1998-06-30

    Retinoids, such as the naturally occurring all-trans-retinoic acid (atRA) and synthetic ligand CD367 modulate ligand-dependent transcription through retinoic acid receptors (RARs). Retinoid binding to RAR is believed to trigger structural transitions in the ligand-binding domain (LBD), leading to helix H1 and helix H12 repositioning and coactivator recruitment and corepressor release. Here, we carried out a detailed mutagenesis analysis of the H11-H12 loop (designated the L box) to study its contribution to hRARalpha activation process. Point mutations that reduced transactivation by atRA also reduced atRA-induced transrepression of AP1 transcription, correlating ligand-induced activation and repression. However, a correlation was not observed with these mutations when tested with another ligand CD367, a synthetic agonist with binding properties identical to those of atRA. Transcription was strongly inhibited in the presence of CD367 for some mutants, thus leading to an inverse agonist activity of this ligand. None of these mutations significantly altered binding affinity for either ligand, indicating that altered transcription was not caused by altered ligand binding by these mutations. Although simple correlations with transcriptional activities were not found, these mutations were also characterized by altered ligand-induced structural transitions, which were distinct for the atRA-hRARalpha or CD367-hRARalpha complexes. These results indicate that amino acids in the L box are involved in specifying trans-repressive and trans-activating properties of the hRARalpha, and support the notion that different agonists induce distinct conformations in the LBD of the receptor.

  13. 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

  14. 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

  15. Two isoforms of Xenopus retinoic acid receptor gamma 2 (B) exhibit differential expression and sensitivity to retinoic acid during embryogenesis.

    PubMed

    Crawford, M J; Liversage, R A; Varmuza, S L

    1995-01-01

    We report the isolation of two retinoic acid receptor isoforms (RAR gamma), which differ only in the 5'untranslated and putative N-terminus A regions. The two isoforms appear to serve as early markers for the presumptive neural axis; however, their expression patterns differ. RAR-gamma 2.1 is first expressed at gastrulation at the dorsal lip and subsequently along the presumptive neural axis. RAR- gamma 2.2 represents the full-length sequence of a receptor cDNA already partially characterized and present as a maternal transcript [Ellinger-Ziegelbauer and Dreyer (1991); Genes Dev 5:94-104, (1993): Mech Dev 41:31-46; Pfeffer and DeRobertis, (1994) Mech Dev: 45:147-153]. Unlike RAR-gamma 2.2, the 2.1 variant is not expressed either in pre-somitic mesoderm or notochord. RAR-gamma 2.1 is strongly expressed in branchial arches and to a lesser extent in the neural floor plate. The two isoforms also exhibit differential sensitivity to retinoic acid. Constitutive expression of RAR gamma 2.2 following neurulation appears to be depressed by treatment with retinoic acid, but domains of highest expression, namely, the head and tail, remain relatively unaffected, as do patterns of expression prior to late neurulation. By contrast, RAR-gamma 2.1 is not transcribed in retinoid-inhibited structures. Using microinjection techniques, we show that changes of RAR-gamma 2.1 expression in presumptive head structures occur as an early and local consequence of retinoic acid administration. Since RAR-gamma 2.1 expression is inhibited by retinoic acid, we tested to see if other treatments that perturb axis formation had any effect. Surprisingly, UV irradiation did not suppress that its inhibition by retinoic acid is not due solely to inhibition of anterior neural development. These experiments demonstrate a new subdivision of isoforms that undergo differential expression during development and that exhibit differential sensitivity to retinoic acid and to UV. This sensitivity and the presence

  16. Combined staurosporine and retinoic acid induces differentiation in retinoic acid resistant acute promyelocytic leukemia cell lines

    PubMed Central

    Ge, Dong-zheng; Sheng, Yan; Cai, Xun

    2014-01-01

    All-trans retinoic acid (ATRA) resistance has been a critical problem in acute promyelocytic leukemia (APL) relapsed patients. In ATRA resistant APL cell lines NB4-R1 and NB4-R2, the combination of staurosporine and ATRA synergized to trigger differentiation accompanied by significantly enhanced protein level of CCAAT/enhancer binding protein ε (C/EBPε) and C/EBPβ as well as the phosphorylation of mitogen-activated protein (MEK) and extracellular signal-regulated kinase (ERK). Furthermore, attenuation of the MEK activation blocked not only the differentiation but also the increased protein level of C/EBPε and C/EBPβ. Taken together, we concluded that the combination of ATRA and staurosporine could overcome differentiation block via MEK/ERK signaling pathway in ATRA-resistant APL cell lines. PMID:24769642

  17. 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.

  18. Molecular recognition of CYP26A1 binding pockets and structure-activity relationship studies for design of potent and selective retinoic acid metabolism blocking agents.

    PubMed

    Sun, Bin; Song, Shuai; Hao, Chen-Zhou; Huang, Wan-Xu; Liu, Chun-Chi; Xie, Hong-Lei; Lin, Bin; Cheng, Mao-Sheng; Zhao, Dong-Mei

    2015-03-01

    All-trans-retinoic acid (ATRA), the biologically most active metabolite of vitamin A, plays a major role in the regulation of cellular differentiation and proliferation, and it is also an important pharmacological agent particularly used in the treatment of cancer, skin, neurodegenerative and autoimmune diseases. However, ATRA is very easy to be metabolized into 4-hydroxyl-RA in vivo by CYP26A1, an inducible cytochrome P450 enzyme, eventually into more polar metabolites. Therefore, it is vital to develop specific retinoic acid metabolism blocking agents (RAMBAs) to inhibit the metabolic enzyme CYP26A1 in the treatment of relevant diseases aforementioned. In this study, CYP26A1 and its interactions with retinoic acid-competitive metabolism blocking agents were investigated by a combined ligand- and structure-based approach. First, since the crystal structure of CYP26A1 protein has not been determined, we constructed the 3D structure of CYP26A1 using homology modeling. In order to achieve a deeper insight into the mode of action of RAMBAs in the active site, the molecular superimposition model and the common feature pharmacophore model were constructed, and molecular docking was performed. The molecular superimposition model is composed of three features: the main chain groups, side chain groups, and azole groups. The common feature pharmacophore model consists of five chemical features: four hydrophobic groups and one hydrogen acceptor (HHHHA). The results of molecular docking show that the characteristic groups of RAMBAs were mapped into three different active pockets, respectively. A structure-activity relationship (SAR) was obtained by a combination of the molecular superimposition and docking results with the pharmacophore model. This study gives more insight into the interaction model inside the CYP26A1 active site and provides guidance for the design of more potent and possibly more selective RAMBAs. PMID:25541526

  19. Molecular recognition of CYP26A1 binding pockets and structure-activity relationship studies for design of potent and selective retinoic acid metabolism blocking agents.

    PubMed

    Sun, Bin; Song, Shuai; Hao, Chen-Zhou; Huang, Wan-Xu; Liu, Chun-Chi; Xie, Hong-Lei; Lin, Bin; Cheng, Mao-Sheng; Zhao, Dong-Mei

    2015-03-01

    All-trans-retinoic acid (ATRA), the biologically most active metabolite of vitamin A, plays a major role in the regulation of cellular differentiation and proliferation, and it is also an important pharmacological agent particularly used in the treatment of cancer, skin, neurodegenerative and autoimmune diseases. However, ATRA is very easy to be metabolized into 4-hydroxyl-RA in vivo by CYP26A1, an inducible cytochrome P450 enzyme, eventually into more polar metabolites. Therefore, it is vital to develop specific retinoic acid metabolism blocking agents (RAMBAs) to inhibit the metabolic enzyme CYP26A1 in the treatment of relevant diseases aforementioned. In this study, CYP26A1 and its interactions with retinoic acid-competitive metabolism blocking agents were investigated by a combined ligand- and structure-based approach. First, since the crystal structure of CYP26A1 protein has not been determined, we constructed the 3D structure of CYP26A1 using homology modeling. In order to achieve a deeper insight into the mode of action of RAMBAs in the active site, the molecular superimposition model and the common feature pharmacophore model were constructed, and molecular docking was performed. The molecular superimposition model is composed of three features: the main chain groups, side chain groups, and azole groups. The common feature pharmacophore model consists of five chemical features: four hydrophobic groups and one hydrogen acceptor (HHHHA). The results of molecular docking show that the characteristic groups of RAMBAs were mapped into three different active pockets, respectively. A structure-activity relationship (SAR) was obtained by a combination of the molecular superimposition and docking results with the pharmacophore model. This study gives more insight into the interaction model inside the CYP26A1 active site and provides guidance for the design of more potent and possibly more selective RAMBAs.

  20. Nuclear retinoic acid receptors: conductors of the retinoic acid symphony during development.

    PubMed

    Samarut, Eric; Rochette-Egly, Cécile

    2012-01-30

    The vitamin A derivative, retinoic acid (RA), is essential for embryonic development through the activation of cognate nuclear receptors, RARs, which work as ligand dependent regulators of transcription. In vitro studies revealed how RARs control gene expression at the molecular level and now it appears that it is fine-tuned by a phosphorylation code. In addition, several genetic approaches provided valuable insights on the functions of RARs during development and on the influence of other actors such as the enzymes involved in RA synthesis and degradation and other signaling pathways. It appears that RARs are the conductors of the RA signaling symphony through controlling the dynamics and the coordination of the different players and development steps.

  1. Retinoic acid receptors inhibit AP1 activation by regulating extracellular signal-regulated kinase and CBP recruitment to an AP1-responsive promoter.

    PubMed

    Benkoussa, Madjid; Brand, Céline; Delmotte, Marie-Hélène; Formstecher, Pierre; Lefebvre, Philippe

    2002-07-01

    Retinoids exhibit antineoplastic activities that may be linked to retinoid receptor-mediated transrepression of activating protein 1 (AP1), a heterodimeric transcription factor composed of fos- and jun-related proteins. Here we show that transcriptional activation of an AP1-regulated gene through the mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase (ERK) pathway (MAPK(ERK)) is characterized, in intact cells, by a switch from a fra2-junD dimer to a junD-fosB dimer loading on its promoter and by simultaneous recruitment of ERKs, CREB-binding protein (CBP), and RNA polymerase II. All-trans-retinoic acid (atRA) receptor (RAR) was tethered constitutively to the AP1 promoter. AP1 transrepression by retinoic acid was concomitant to glycogen synthase kinase 3 activation, negative regulation of junD hyperphosphorylation, and to decreased RNA polymerase II recruitment. Under these conditions, fra1 loading to the AP1 response element was strongly increased. Importantly, CBP and ERKs were excluded from the promoter in the presence of atRA. AP1 transrepression by retinoids was RAR and ligand dependent, but none of the functions required for RAR-mediated transactivation was necessary for AP1 transrepression. These results indicate that transrepressive effects of retinoids are mediated through a mechanism unrelated to transcriptional activation, involving the RAR-dependent control of transcription factors and cofactor assembly on AP1-regulated promoters.

  2. Role of the retinoic acid receptor-α in HIV-associated nephropathy.

    PubMed

    Ratnam, Krishna K; Feng, Xiaobei; Chuang, Peter Y; Verma, Vikram; Lu, Ting-Chi; Wang, Jinshan; Jin, Yuanmeng; Farias, Eduardo F; Napoli, Joseph L; Chen, Nan; Kaufman, Lewis; Takano, Tomoko; D'Agati, Vivette D; Klotman, Paul E; He, John C

    2011-03-01

    All-trans retinoic acid protects against the development of HIV-associated nephropathy (HIVAN) in HIV-1 transgenic mice (Tg26). In vitro, all-trans retinoic acid inhibits HIV-induced podocyte proliferation and restores podocyte differentiation markers by activating its receptor-α (RARα). Here, we report that Am580, a water-soluble RARα-specific agonist, attenuated proteinuria, glomerosclerosis, and podocyte proliferation, and restored podocyte differentiation markers in kidneys of Tg26 mice. Furthermore, RARα-/- Tg26 mice developed more severe kidney and podocyte injury than did RARα+/- Tg26 mice. Am580 failed to ameliorate kidney injury in RARα-/- Tg26 mice, confirming our hypothesis that Am580 acts through RARα. Although the expression of RARα-target genes was suppressed in the kidneys of Tg26 mice and of patients with HIVAN, the expression of RARα in the kidney was not different between patients with HIVAN and minimal change disease. However, the tissue levels of retinoic acid were reduced in the kidney cortex and isolated glomeruli of Tg26 mice. Consistent with this, the expression of two key enzymes in the retinoic acid synthetic pathway, retinol dehydrogenase type 1 and 9, and the overall enzymatic activity for retinoic acid synthesis were significantly reduced in the glomeruli of Tg26 mice. Thus, a defect in the endogenous synthesis of retinoic acid contributes to loss of the protection by retinoic acid in HIVAN. Hence, RARα agonists may be potential agents for the treatment of HIVAN.

  3. Expression of the helix-loop-helix protein inhibitor of DNA binding-1 (ID-1) is activated by all-trans retinoic acid in normal human keratinocytes

    SciTech Connect

    Villano, C.M.; White, L.A. . E-mail: lawhite@aesop.rutgers.edu

    2006-08-01

    The ID (inhibitor of differentiation or DNA binding) helix-loop-helix proteins are important mediators of cellular differentiation and proliferation in a variety of cell types through regulation of gene expression. Overexpression of the ID proteins in normal human keratinocytes results in extension of culture lifespan, indicating that these proteins are important for epidermal differentiation. Our hypothesis is that the ID proteins are targets of the retinoic acid signaling pathway in keratinocytes. Retinoids, vitamin A analogues, are powerful regulators of cell growth and differentiation and are widely used in the prevention and treatment of a variety of cancers in humans. Furthermore, retinoic acid is necessary for the maintenance of epithelial differentiation and demonstrates an inhibitory action on skin carcinogenesis. We examined the effect of all-trans retinoic acid on expression of ID-1, -2, -3, and -4 in normal human keratinocytes and found that exposure of these cells to all-trans retinoic acid causes an increase in both ID-1 and ID-3 gene expression. Furthermore, our data show that this increase is mediated by increased transcription involving several cis-acting elements in the distal portion of the promoter, including a CREB-binding site, an Egr1 element, and an YY1 site. These data demonstrate that the ID proteins are direct targets of the retinoic acid signaling pathway. Given the importance of the ID proteins to epidermal differentiation, these results suggest that IDs may be mediating some of the effects of all-trans retinoic acid in normal human keratinocytes.

  4. Retinoic acid receptor alpha (RAralpha) Mutations in Human Leukemia.

    PubMed

    Parrado, A; Chomienne, C; Padua, R A

    2000-10-01

    The retinoic acid receptor alpha (RARalpha) plays a central role in the biology of the myeloid cellular compartment. Chromosomal translocations involving the RARalpha locus probably represent the malignant initiating events in acute promyelocytic leukemia (APL). Recent studies that identify novel interactions between RARalpha and the nuclear receptor co-activators and co-repressors, new functions of the oncogenic RARalpha fusion proteins and their catabolism in retinoic acid-induced differentiation, and the availability of new transgenic mice models have provided important insights into our understanding of the mechanisms by which mutant forms of RARalpha can be implicated in the development of leukemia. Novel alterations of the RARalpha gene identified in hematopoietic malignant disorders other than APL, such as myelodysplastic syndromes, non-APL acute myeloid leukemias and B-chronic lymphocytic leukemias, suggest that disruption of the RARalpha gene might predispose to myeloid and lymphoid disorders.

  5. Retinoic Acid-Mediated Regulation of GLI3 Enables Efficient Motoneuron Derivation from Human ESCs in the Absence of Extrinsic SHH Activation

    PubMed Central

    Calder, Elizabeth L.; Steinbeck, Julius A.; Tu, Edmund; Keros, Sotirios; Ying, Shui-Wang; Jaiswal, Manoj K.; Cornacchia, Daniela; Goldstein, Peter A.; Tabar, Viviane

    2015-01-01

    The derivation of somatic motoneurons (MNs) from ES cells (ESCs) after exposure to sonic hedgehog (SHH) and retinoic acid (RA) is one of the best defined, directed differentiation strategies to specify fate in pluripotent lineages. In mouse ESCs, MN yield is particularly high after RA + SHH treatment, whereas human ESC (hESC) protocols have been generally less efficient. In an effort to optimize yield, we observe that functional MNs can be derived from hESCs at high efficiencies if treated with patterning molecules at very early differentiation steps before neural induction. Remarkably, under these conditions, equal numbers of human MNs were obtained in the presence or absence of SHH exposure. Using pharmacological and genetic strategies, we demonstrate that early RA treatment directs MN differentiation independently of extrinsic SHH activation by suppressing the induction of GLI3. We further demonstrate that neural induction triggers a switch from a poised to an active chromatin state at GLI3. Early RA treatment prevents this switch by direct binding of the RA receptor at the GLI3 promoter. Furthermore, GLI3 knock-out hESCs can bypass the requirement for early RA patterning to yield MNs efficiently. Our data demonstrate that RA-mediated suppression of GLI3 is sufficient to generate MNs in an SHH-independent manner and that temporal changes in exposure to patterning factors such as RA affect chromatin state and competency of hESC-derived lineages to adopt specific neuronal fates. Finally, our work presents a streamlined platform for the highly efficient derivation of human MNs from ESCs and induced pluripotent stem cells. SIGNIFICANCE STATEMENT Our study presents a rapid and efficient protocol to generate human motoneurons from embryonic and induced pluripotent stem cells. Surprisingly, and in contrast to previous work, motoneurons are generated in the presence of retinoic acid but in the absence of factors that activate sonic hedgehog signaling. We

  6. Essential role for retinoic acid in the promotion of CD4+ T cell effector responses via retinoic acid receptor alpha

    PubMed Central

    Hall, J.A.; Cannons, J.L.; Grainger, J.R.; Santos, L.M. Dos; Hand, T.W.; Naik, S.; Wohlfert, E.A.; Chou, D.B.; Oldenhove, G.; Robinson, M.; Grigg, M.E.; Kastenmayer, R.; Schwartzberg, P.L.; Belkaid, Y.

    2012-01-01

    SUMMARY Vitamin A and its metabolite, retinoic acid (RA), have recently been implicated in the regulation of immune homeostasis via the peripheral induction of regulatory T cells. Here we show that RA is also required to elicit proinflammatory CD4+ helper T cell responses to infection and mucosal vaccination. Retinoic acid receptor alpha (RARα) is the critical mediator of these effects. Strikingly, antagonism of RAR signaling and deficiency in RARα(Rara−/−) results in a cell autonomous CD4+ T cell activation defect. Altogether, these findings reveal a fundamental role for the RA/RARα axis in the development of both regulatory and inflammatory arms of adaptive immunity and establish nutritional status as a broad regulator of adaptive T cell responses. PMID:21419664

  7. Catalase potentiates retinoic acid-induced THP-1 monocyte differentiation into macrophage through inhibition of peroxisome proliferator-activated receptor gamma.

    PubMed

    Ding, Qiurong; Jin, Ting; Wang, Zhenzhen; Chen, Yan

    2007-06-01

    Macrophage differentiation plays a pivotal role in cardiovascular diseases and many other physiological processes. However, the role of reaction oxygen species in macrophage differentiation has not been elucidated. Here, we report functional characterization of catalase, an enzyme that degrades hydrogen peroxide (H(2)O(2)), in THP-1 monocyte differentiation. Treatment of THP-1 cells with catalase was able to synergize with all-trans retinoic acid (ATRA) to enhance macrophage differentiation, demonstrated by changes of cell adherence, cell cycle arrest, nitroblue tetrazolium reduction, and expression of differentiation markers including CD68, CD11b, and matrix metalloproteinase 9 (MMP9). ATRA could stimulate retinoic acid (RA) receptor-mediated transcription, but this was not affected by catalase. However, ATRA and catalase were capable of reducing transcriptional activity mediated by peroxisome proliferator-activated receptor gamma (PPARgamma). Consistently, PPARgamma antagonists enhanced, and PPARgamma agonists inhibited MMP9 expression stimulated by ATRA and catalase in THP-1 cells. Therefore, these data indicate that catalase is able to potentiate ATRA-induced macrophage differentiation by inhibition of PPARgamma activity, underscoring an important interplay between H(2)O(2), RA, and PPARgamma in macrophages.

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. Ligand-dependent activation of transcription in vitro by retinoic acid receptor α/retinoid X receptor α heterodimers that mimics transactivation by retinoids in vivo

    PubMed Central

    Dilworth, F. Jeffrey; Fromental-Ramain, Catherine; Remboutsika, Eumorphia; Benecke, Arndt; Chambon, Pierre

    1999-01-01

    All-trans and 9-cis retinoic acids (RA) signals are transduced by retinoic acid receptor/retinoid X receptor (RAR/RXR) heterodimers that act as functional units controlling the transcription of RA-responsive genes. With the aim of elucidating the underlying molecular mechanisms, we have developed an in vitro transcription system using a chromatin template made up of a minimal promoter and a direct repeat with 5-spacing-based RA response element. RARα and RXRα were expressed in and purified from baculovirus-infected Sf9 cells, and transcription was carried out by using naked DNA or chromatin templates. Transcription from naked templates was not affected by the presence of RA and/or RAR/RXR heterodimers. In contrast, very little transcription occurred from chromatin templates in the absence of RA or RAR/RXR heterodimers whereas their addition resulted in a dosage-dependent stimulation of transcription that never exceeded that occurring on naked DNA templates. Most importantly, the addition of synthetic agonistic or antagonistic retinoids to the chromatin transcription system mimicked their stimulatory or inhibitory action in vivo, and activation by a RXR-specific retinoid was subordinated to the binding of an agonist ligand to the RAR partner. Moreover, the addition of the p300 coactivator generated a synergistic enhancement of transcription. Thus, the dissection of this transcription system ultimately should lead to the elucidation of the molecular mechanisms by which RAR/RXR heterodimers control transcription in a ligand-dependent manner. PMID:10051583

  14. 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

  15. Evidence for impaired retinoic acid receptor-thyroid hormone receptor AF-2 cofactor activity in human lung cancer.

    PubMed Central

    Moghal, N; Neel, B G

    1995-01-01

    Retinoic acid (RA) is required for normal airway epithelial cell growth and differentiation both in vivo and in vitro. One of the earliest events following the exposure of bronchial epithelial cells to RA is the strong induction of RA receptor beta (RAR beta) mRNA. Previous work established that many lung cancer cell lines and primary tumors display abnormal RAR beta mRNA expression, most often absence or weak expression of the RAR beta 2 isoform, even after RA treatment. Restoration of RAR beta 2 into RAR beta-negative lung cancer cell lines has been reported to inhibit tumorigenicity. Since RAR beta 2 inactivation may contribute to lung cancer, we have investigated the molecular mechanism of defective RAR beta 2 expression. Nuclear run-on assays and transient transfections with RAR beta 2 promoter constructs indicate the presence of trans-acting transcriptional defects in most lung cancer cell lines, which map to the RA response element (RARE). These defects cannot be complemented by RAR-retinoid X receptor cotransfection and can be separated into two types: (i) one affecting transcription from direct repeat RAREs, but not palindromic RAREs, and (ii) another affecting transcription from both types of RARE. Studies using chimeras between RAR alpha, TR alpha, and other transcription factors suggest the existence of novel RAR-thyroid hormone receptor AF-2-specific cofactors, which are necessary for high levels of transcription. Furthermore, these factors may be frequently inactivated in human lung cancer. PMID:7791800

  16. Cilostazol suppresses β-amyloid production by activating a disintegrin and metalloproteinase 10 via the upregulation of SIRT1-coupled retinoic acid receptor-β.

    PubMed

    Lee, Hye Rin; Shin, Hwa Kyoung; Park, So Youn; Kim, Hye Young; Lee, Won Suk; Rhim, Byung Yong; Hong, Ki Whan; Kim, Chi Dae

    2014-11-01

    The accumulation of plaques of β-amyloid (Aβ) peptides, a hallmark of Alzheimer's disease, results from the sequential cleavage of amyloid precursor protein (APP) by activation of β- and γ-secretases. However, the production of Aβ can be avoided by alternate cleavage of APP by α-and γ-secretases. We hypothesized that cilostazol attenuates Aβ production by increasing a disintegrin and metalloproteinase 10 (ADAM10)/α-secretase activity via SIRT1-coupled retinoic acid receptor-β (RARβ) activation in N2a cells expressing human APP Swedish mutation (N2aSwe). To evoke endogenous Aβ overproduction, the culture medium was switched from medium containing 10% fetal bovine serum (FBS) to medium containing 1% FBS, and cells were cultured for 3∼24 hr. After depletion of FBS in media, N2aSwe cells showed increased accumulations of full-length APP (FL-APP) and Aβ in a time-dependent manner (3-24 hr) in association with decreased ADAM10 protein expression. When pretreated with cilostazol (10-30 μM), FL-APP and Aβ levels were significantly reduced, and ADAM10 and α-secretase activities were restored. Furthermore, the effect of cilostazol on ADAM10 expression was antagonized by pretreating Rp-cAMPS and sirtinol and by SIRT1-gene silencing. In the N2aSwe cells overexpressing the SIRT1 gene, ADAM10, and sAPPα levels were significantly elevated. In addition, like all-trans retinoic acid, cilostazol enhanced the protein expressions of RARβ and ADAM10, and the cilostazol-stimulated ADAM10 elevation was significantly attenuated by LE135 (a RARβ inhibitor), sirtinol, and RARβ-gene silencing. In conclusion, cilostazol suppresses the accumulations of FL-APP and Aβ by activating ADAM10 via the upregulation of SIRT1-coupled RARβ.

  17. Treatment of acne vulgaris with the retinoic acid derivative Ro 11-1430. A controlled clinical trial against retinoic acid.

    PubMed

    Christiansen, J; Holm, P; Reymann, F

    1976-01-01

    In a double-blind, randomized, group-comparative clinical trial, 31 patients with acne vulgaris received topical treatment for 6-8 weeks with a lotion containing either 0.05% retinoic acid or 0.1% of the retinoic acid derivative Ro 11-1430. The side-effects erythema, desquamation and burning were significantly less frequent with Ro 11-1430 than with retinoic acid. The treatments appeared to be approximately equally effective in reducing the number of acne elements, but due to the limited number of patients studied, the trial was admittedly not sufficient to detect differences with regard to therapeutic efficacy.

  18. Transgenic retinoic acid sensor lines in zebrafish indicate regions of available embryonic retinoic acid

    PubMed Central

    Mandal, Amrita; Rydeen, Ariel; Anderson, Jane; Sorrell, Mollie R.J.; Zygmunt, Tomas; Torres-Vázquez, Jesús; Waxman, Joshua S.

    2013-01-01

    Background Retinoic acid (RA) signaling plays a critical role in vertebrate development. Transcriptional reporters of RA signaling in zebrafish, thus far, have not reflected the broader availability of embryonic RA, necessitating additional tools to enhance our understanding of the spatial and temporal activity of RA signaling in vivo. Results We have generated novel transgenic RA sensors in which a RA receptor (RAR) ligand-binding domain (RLBD) is fused to the Gal4 DNA binding domain (GDBD) or a VP16-GDBD (VPBD) construct. Stable transgenic lines expressing these proteins when crossed with UAS reporter lines are responsive to RA. Interestingly, the VPBD RA sensor is significantly more sensitive than the GDBD sensor and demonstrates there may be almost ubiquitous availability of RA within the early embryo. Using confocal microscopy to compare the expression of the GDBD RA sensor to our previously established RA signaling transcriptional reporter line, Tg(12XRARE:EGFP), illustrates these reporters have significant overlap, but that expression from the RA sensor is much broader. We also identify previously unreported domains of expression for the Tg(12XRARE:EGFP) line. Conclusions Our novel RA sensor lines will be useful and complementary tools for studying RA signaling during development and anatomical structures independent of RA signaling. PMID:23703807

  19. Retinoic acid conjugates as potential antitumor agents: synthesis and biological activity of conjugates with Ara-A, Ara-C, 3(2H)-furanone, and aniline mustard moieties.

    PubMed

    Manfredini, S; Simoni, D; Ferroni, R; Bazzanini, R; Vertuani, S; Hatse, S; Balzarini, J; De Clercq, E

    1997-11-01

    In a dual targeting approach, to explore the ability of tretinoin (all-trans-retinoic acid) to behave as a covalent carrier for cytotoxic entities, conjugates of retinoic acid with a few representative molecules, being important examples of antitumor pharmacophores (i.e., nucleoside analogues and alkylating agents), have been synthesized and tested for their cytostatic and differentiating activity. All compounds were stable to in vitro hydrolysis in human plasma and more lipophilic than the parent compounds, thus consenting enhanced uptake into the cells. Among the nucleoside analogues the Ara-C derivatives 3 and 6 and the Ara-A derivative 7 proved the most cytostatic (IC50 < 0.32 microgram/mL) resulting from 25- to > 144-fold more active (Ara-A derivatives) or at least as equally active (Ara-C derivatives) as compared to the parent nucleosides. Compound 3, endowed with a highly lipophilic silyl moiety at the 3' and 5' positions, showed the highest differentiating activity (54% and 44% differentiated HL-60 cells at 0.2 and 0.05 microgram/mL respectively). With regard to the retinoic acid conjugates of alkylating agents, compound 10 was the most cytostatic agent (IC50 < 0.32 microgram/mL) and the most potent differentiating agent (33-34% at 0.32 and 0.08 microgram/mL). These structures may also be regarded as analogs of either retinoic acid or the cytotoxic compound.

  20. 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

  1. Immunohistochemical analysis of cartilage-derived retinoic acid-sensitive protein (CD-RAP)/melanoma inhibitory activity (MIA) in murine, canine, bovine and equine cerebrospinal tissues.

    PubMed

    Tokunaga, Satoshi; Fujiki, Makoto; Yabuki, Akira; Misumi, Kazuhiro

    2012-04-01

    Cartilage-derived retinoic acid-sensitive protein (CD-RAP)/melanoma inhibitory activity (MIA), which appears abundantly in hypertrophic cartilage at the stage of endochondral ossification, is also detected in cerebrospinal fluid (CSF) following spinal cord injury. In this study, the localization of the CD-RAP/MIA molecule in normal tissues of the spine and brain obtained from mice, rats, dogs, cattle and horses was examined using immunohistochemistry with a specific antibody. The positive signals of CD-RAP/MIA were found at nerve cells in the spinal cords of all species and were especially strong at cerebellar Purkinje cells. The results suggested that CD-RAP/MIA included in normal cerebrospinal tissues could be a biomarker associated with tissue injuries, as the molecules might flow into the CSF.

  2. 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.

  3. 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

  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.

  5. In vitro assessment of retinoic acid and aryl hydrocarbon receptor activity of treated effluent from 39 wastewater-treatment plants in Victoria, Australia.

    PubMed

    Allinson, M; Shiraishi, F; Salzman, S A; Allinson, G

    2011-11-01

    This project involved the collection of final effluent samples from 39 wastewater-treatment plants (WWTPs) in Victoria, Australia, in late summer (late February to early March 2007). The 39 WWTPs included 15 lagoon-based plants and 24 with activated sludge-based processes. Samples were collected and subjected to measurement of retinoic acid receptor (RAR) and aryl hydrocarbon receptor (AhR) activity of the dissolved phase using yeast-based recombinant receptor-reporter gene bioassays. More than 90% of the effluents examined in this study elicited RAR activity (<0.5-198 ng/l a-t-RA equivalents [EQ]). All of the effluents had AhR activity (16-279 ng/l βNF EQ). Notwithstanding the paucity of comparative data, on the whole, the levels of RAR and AhR activity observed in this pilot survey of Victorian WWTP effluents were greater than those recently reported internationally. One assumption commonly made is that WWTP discharges will be diluted significantly in the receiving environment, further decreasing the potential risk of the discharges. Making this assumption may not be appropriate for some of Victoria's more ephemeral waterways or where effluent is discharged to an enclosed water body, such as a lake or terminal wetland. However, even where WWTP discharges represent all of the environmental flow in the warmer months, the observed RAR and AhR activity (as all-trans-retinoic acid (RA) and 2,3,7,8-tetrachloro-dibenzo-p-dioxin [TCDD] EQ, respectively) was still significantly lower than the concentrations of RA, and 2,3,7,8-TCCD known to cause developmental malformations in fish larvae after short-term exposure to these chemicals. Of perhaps greater concern, WWTP effluent can contain significant suspended solids (essentially biosolids), which may be a considerable sink for some hormonally active, hydrophobic compounds, and which may in turn increase the long-term exposure risk for aquatic fauna. Further studies of the nuclear and AhR activity of WWTP effluent suspended

  6. Retinoic acid modulates rat Ito cell proliferation, collagen, and transforming growth factor beta production.

    PubMed Central

    Davis, B H; Kramer, R T; Davidson, N O

    1990-01-01

    Recent studies suggest that vitamin A plays an inhibitory role with respect to "activation" of the hepatic Ito cell, a likely effector of hepatic fibrogenesis. Ito cell "activation" during fibrogenesis is characterized by a decrease in intracellular vitamin A and an increase in cellular proliferation and collagen production. To explore the hypothesis that retinoids have the capacity to diminish Ito cell activation, cultured Ito cells were exposed to retinoic acid and its effects assessed on three key features: cell proliferation, collagen protein production and mRNA abundance, and transforming growth factor beta protein production. Retinoic acid was 100-1,000X more potent than retinol with respect to inhibition of Ito cell proliferation. Interstitial collagen and transforming growth factor beta production were also reduced by 10(-6) M retinoic acid. The relative abundance of type I collagen mRNA however, was not significantly altered. By contrast, retinoic acid administration to rats caused a marked reduction in the abundance of type I collagen mRNA in both total hepatic and purified Ito cell RNA. The relative abundance of rat hepatic fibronectin or apolipoprotein E mRNA was not significantly altered. These studies demonstrate that retinoic acid can differentially modulate several key features of hepatic fibrogenesis in vitro and in vivo. Images PMID:2254460

  7. 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

  8. Retinoic acid 5,6-epoxidation by hemoproteins.

    PubMed

    Iwahashi, H; Ikeda, A; Negoro, Y; Kido, R

    1986-01-01

    Retinoic acid 5,6-epoxidase activity was found in several hemoproteins such as human oxy- and methemoglobin (HbO2 and MetHb), equine skeletal muscle oxy- and metmyoglobin (MbO2 and MetMb), bovine liver catalase, and horseradish peroxidase. Hematin also catalyzed retinoic acid 5,6-epoxidation. The results suggest that the heme moiety participates in the epoxidation. However, neither horse heart cytochrome c, nor free ferrous ion nor free ferric ion exhibited the epoxidase activity. Some hemoproteins (HbO2, MetHb, MbO2, MetMb, catalase, peroxidase, and hematin) exhibited characteristic individual pH dependences of the activity, suggesting that the epoxidase activities of the hemoproteins are influenced by the apoenzymes to some degree. This view is also supported by the finding that preincubation of an HbO2 preparation at various temperatures (37-70 degrees C) reduced its epoxidase activity with increasing temperature, whereas the activity of hematin was unaffected. Active oxygen scavengers such as mannitol, catalase, and superoxide dismutase exhibited no effect on the epoxidase activities of HbO2, MetHb, MbO2, and MetMb. A ligand of heme, CN- (100 mM), inhibited the epoxidase activities but N3- (100 mM) did not. The epoxidase activities were completely inhibited by NADPH, NADH, and/or 2-mercaptoethanol but not by NADP+ and/or NAD+. An intermediate in the epoxidation may be reduced by NADPH, NADH and/or 2-mercaptoethanol. Radical species can be considered as plausible candidates for the intermediate. PMID:3957898

  9. 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.

  10. 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

  11. Suppression of Spermatogenesis by Bisdichloroacetyldiamines Is Mediated by Inhibition of Testicular Retinoic Acid Biosynthesis

    PubMed Central

    Amory, John K.; Muller, Charles H.; Shimshoni, Jakob A.; Isoherranen, Nina; Paik, Jisun; Moreb, Jan S.; Amory, David W.; Evanoff, Ryan; Goldstein, Alex S.; Griswold, Michael D.

    2012-01-01

    The bisdichloroacetyldiamine WIN 18,446 reversibly inhibits spermatogenesis in many species, including humans; however, the mechanism by which WIN 18,446 functions is unknown. As retinoic acid is essential for spermatogenesis, we hypothesized that WIN 18,446 might inhibit retinoic acid biosynthesis from retinol (vitamin A) within the testes by inhibiting the enzyme aldehyde dehydrogenase 1a2 (ALDH1a2). We studied the effect of WIN 18,446 on ALDH1a2 enzyme activity in vitro, and on spermatogenesis and fertility in vivo, in mature male rabbits for 16 weeks. WIN 18,446 markedly inhibited ALDH1a2 enzyme activity in vitro with an IC50 of 0.3 μM. In vivo, the oral administration of 200 mg/kg WIN 18,446 to male rabbits for 16 weeks significantly reduced intratesticular concentrations of retinoic acid, severely impaired spermatogenesis, and caused infertility. Reduced concentrations of intratesticular retinoic acid were apparent after only 4 weeks of treatment and preceded the decrease in sperm counts and the loss of mature germ cells in tissue samples. Sperm counts and fertility recovered after treatment was discontinued. These findings demonstrate that bisdichloroacetyldiamines such as WIN 18,446 reversibly suppress spermatogenesis via inhibition of testicular retinoic acid biosynthesis by ALDH1a2. These findings suggest that ALDH1a2 is a promising target for the development of a reversible, nonhormonal male contraceptive. PMID:20705791

  12. Evaluation of effectiveness of chemical and physical sewage treatment technologies for removal of retinoic acid receptor agonistic activity detected in sewage effluent.

    PubMed

    Inoue, D; Matsui, H; Sei, K; Hu, J; Yang, M; Aragane, J; Hirotsuji, J; Ike, M

    2009-01-01

    Retinoic acid receptor (RAR) is a nuclear receptor involved in vertebrate morphogenesis, growth, cellular differentiation, and tissue homeostasis. Excess expression of the retinoid signaling can cause various developmental toxicities in animals and humans. We previously found that influents from sewage treatment plants (STPs) in Japan had a RAR agonistic activity and the activity cannot be removed completely by conventional biological treatments. In this study, we assessed the performance of chemical and physical sewage treatment technologies-ozonation, ultraviolet treatment, chlorination, coagulation using polyaluminium chloride (PAC) and ferric sulfate, and filtration with ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) membranes-in removal of RAR agonistic activity of STP effluent. All water treatment experiments were conducted in laboratory-scale reactors. The RAR agonistic activity of samples was measured using a yeast two-hybrid assay. Results showed that the effectiveness of tested technologies on the removal of RAR agonistic activity can be ranked as RO or NF > chlorination > ozonation > MF > UV > coagulation with ferric sulfate>coagulation with PAC. Furthermore, the effectiveness of chlorination might rank lower because excess reaction might bring a side effect by producing some RAR agonistic by-product(s).

  13. 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

  14. Serine 157, a retinoic acid receptor alpha residue phosphorylated by protein kinase C in vitro, is involved in RXR.RARalpha heterodimerization and transcriptional activity.

    PubMed

    Delmotte, M H; Tahayato, A; Formstecher, P; Lefebvre, P

    1999-12-31

    Retinoic acid (RA) regulation of cellular proliferation and differentiation is mediated, at least in part, through two related nuclear receptors, RAR and RXR. RA-induced modulation of gene expression leads generally to cellular differentiation, whereas stimulation of the protein kinase C (PKC) signaling pathway is associated with cellular proliferation. Pursuant to our discovery that prolonged activation of PKCs induced a strong decrease in RA responsiveness of a retinoid-inducible reporter gene, we have further investigated the connections between these two signaling pathways. We demonstrate that PKC isoforms alpha and gamma are able to phosphorylate human RARalpha (hRARalpha) in vitro on a single serine residue located in the extended DNA binding domain (T box). The introduction of a negative charge at this position (serine 157) strongly decreased hRARalpha transcriptional activity, whereas a similar mutation at other PKC consensus phosphorylation sites had no effect. The effect on transcriptional activation was correlated with a decrease in the capacity of hRARalpha to heterodimerize with hRXRalpha. Thus hRARalpha is a direct target for PKCalpha and gamma, which may control retinoid receptor transcriptional activities during cellular proliferation and differentiation.

  15. Inhibition of testicular embryonal carcinoma cell tumorigenicity by peroxisome proliferator-activated receptor-β/δ- and retinoic acid receptor-dependent mechanisms.

    PubMed

    Yao, Pei-Li; Chen, Li Ping; Dobrzański, Tomasz P; Phillips, Dylan A; Zhu, Bokai; Kang, Boo-Hyon; Gonzalez, Frank J; Peters, Jeffrey M

    2015-11-01

    Peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) has important physiological functions in control of cell growth, lipid and glucose homeostasis, differentiation and inflammation. To investigate the role of PPARβ/δ in cancer, stable human testicular embryonal carcinoma cell lines were developed that constitutively express PPARβ/δ. Expression of PPARβ/δ caused enhanced activation of the receptor, and this significantly decreased proliferation, migration, invasion, anchorage-independent growth, and also reduced tumor mass and volume of ectopic xenografts derived from NT2/D1 cells compared to controls. The changes observed in xenografts were associated with decreased PPARβ/δ-dependent expression of proliferating cell nuclear antigen and octamer-binding transcription factor-3/4, suggesting suppressed tumor proliferation and induction of differentiation. Inhibition of migration and invasion was mediated by PPARβ/δ competing with formation of the retinoic acid receptor (RAR)/retinoid X receptor (RXR) complex, resulting in attenuation of RARα-dependent matrix metalloproteinase-2 expression and activity. These results demonstrate that PPARβ/δ mediates attenuation of human testicular embryonal carcinoma cell progression through a novel RAR-dependent mechanism and suggest that activation of PPARβ/δ inhibits RAR/RXR dimerization and represents a new therapeutic strategy.

  16. 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.

  17. Promise of Retinoic Acid-Triazolyl Derivatives in Promoting Differentiation of Neuroblastoma Cells.

    PubMed

    Lone, Ali Mohd; Dar, Nawab John; Hamid, Abid; Shah, Wajaht Amin; Ahmad, Muzamil; Bhat, Bilal A

    2016-01-20

    Retinoic acid induces differentiation in various types of cells including skeletal myoblasts and neuroblasts and maintains differentiation of epithelial cells. The present study demonstrates synthesis and screening of a library of retinoic acid-triazolyl derivatives for their differentiation potential on neuroblastoma cells. Click chemistry approach using copper(I)-catalyzed azide-alkyne cycloaddition was adopted for the preparation of these derivatives. The neurite outgrowth promoting potential of retinoic acid-triazolyl derivatives was studied on neuroblastoma cells. Morphological examination revealed that compounds 8a, 8e, 8f, and 8k, among the various derivatives screened, exhibited promising neurite-outgrowth inducing activity at a concentration of 10 μM compared to undifferentiated and retinoic acid treated cells. Further on, to confirm this differentiation potential of these compounds, neuroblastoma cells were probed for expression of neuronal markers such as NF-H and NeuN. The results revealed a marked increase in the NF-H and NeuN protein expression when treated with 8a, 8e, 8f, and 8k compared to undifferentiated and retinoic acid treated cells. Thus, these compounds could act as potential leads in inducing neuronal differentiation for future studies.

  18. Increase in cholesterol sulfotransferase activity during in vitro squamous differentiation of rabbit tracheal epithelial cells and its inhibition by retinoic acid.

    PubMed

    Rearick, J I; Albro, P W; Jetten, A M

    1987-09-25

    It has previously been demonstrated that rabbit tracheal epithelial cells in primary culture undergo terminal differentiation at confluence to yield cornified cells much in analogy to epidermal keratinocytes and that one biochemical marker of this process seems to be the accumulation of cholesterol sulfate by the cells. The current work addresses the possible causes of this accumulation. Our studies show that the stimulation of cholesterol sulfate is paralleled by an increased activity of the biosynthetic enzyme cholesterol sulfotransferase. Squamous differentiated cells exhibited 20- to 30- fold higher levels of this enzyme activity than that in undifferentiated cells. As with other markers of squamous cell differentiation, the increase in cholesterol sulfotransferase can be prevented by the inclusion of retinoids in the cell culture medium. Inhibition of sulfotransferase levels can be observed at concentration of retinoic acid as low as 10(-11) M. The enzyme activity is optimal at pH 7 in buffers containing 0.2 M NaCl and 0.01% Triton X-100. Apparent Michaelis constants for the substrates 3'-phosphoadenosine-5'-phosphosulfate and cholesterol are 1 microM and 0.6 mM, respectively. Our results indicate that the increase in cholesterol sulfotransferase is the proximate cause for the accumulation of cholesterol sulfate in rabbit tracheal epithelial cells during squamous cell differentiation.

  19. Inhibition of transforming growth factor-beta-induced liver fibrosis by a retinoic acid derivative via the suppression of Col 1A2 promoter activity.

    PubMed

    Yang, Kun-Lin; Chang, Wen-Teng; Hung, Kuo-Chen; Li, Eric I C; Chuang, Chia-Chang

    2008-08-22

    Transforming growth factor-beta1 (TGF-beta1) mediates expression of collagen 1A2 (Col 1A2) gene via a synergistic cooperation between Smad2/Smad3 and Sp1, both act on the Col 1A2 gene promoter. In our previous study, we reported that a retinoic acid derivative obtained from Phellinus linteus (designated PL) antagonizes TGF-beta-induced liver fibrosis through regulation of ROS and calcium influx. In this continuing study we seek further the effect of PL on the Smad signaling pathway. We used a Col 1A2 promoter-luciferase construct to study the action of PL on Smad through TGF-beta. We found that PL decreases the promoter activity of Col 1A2, hinders the translocalization of phosphorylated Smad2/3-Smad 4 complex from cytosol into nucleus and inhibits Sp1 binding activity. These results suggest that PL inhibits TGF-beta1-induced Col 1A2 promoter activity through blocking ROS and calcium influx as well as impeding Sp1 binding and translocalization of pSmad 2/3-Smad4 complex into nucleus.

  20. Synergistic activation of Arg1 gene by retinoic acid and IL-4 involves chromatin remodeling for transcription initiation and elongation coupling

    PubMed Central

    Lee, Bomi; Wu, Cheng-Ying; Lin, Yi-Wei; Park, Sung Wook; Wei, Li-Na

    2016-01-01

    All-trans Retinoic acid (RA) and its derivatives are potent therapeutics for immunological functions including wound repair. However, the molecular mechanism of RA modulation in innate immunity is poorly understood, especially in macrophages. We found that topical application of RA significantly improves wound healing and that RA and IL-4 synergistically activate Arg1, a critical gene for tissue repair, in M2 polarized macrophages. This involves feed forward regulation of Raldh2, a rate-limiting enzyme for RA biosynthesis, and requires Med25 to coordinate RAR, STAT6 and chromatin remodeler, Brg1 to remodel the +1 nucleosome of Arg1 for transcription initiation. By recruiting elongation factor TFIIS, Med25 also facilitates transcriptional initiation-elongation coupling. This study uncovers synergistic activation of Arg1 by RA and IL-4 in M2 macrophages that involves feed forward regulation of RA synthesis and dual functions of Med25 in nucleosome remodeling and transcription initiation-elongation coupling that underlies robust modulatory activity of RA in innate immunity. PMID:27166374

  1. Initiating Meiosis: The Case for Retinoic Acid1

    PubMed Central

    Griswold, Michael D.; Hogarth, Cathryn A.; Bowles, Josephine; Koopman, Peter

    2011-01-01

    ABSTRACT The requirement for vitamin A in reproduction and development was first determined from studies of nutritional deficiencies. Subsequent research has shown that embryonic development and both male and female reproduction are modulated by retinoic acid (RA), the active form of vitamin A. Because RA is active in multiple developmental systems, its synthesis, transport, and degradation are tightly regulated in different tissues. A growing body of evidence implicates RA as a requirement for the initiation of meiosis in both male and female mammals, resulting in a mechanistic model involving the interplay of RA, RA synthesis enzymes, RA receptors, and degradative cytochrome P450 enzymes in this system. Recently, that model has been challenged, prompting a review of the established paradigm. While it remains possible that additional molecules may be involved in regulating entry into meiosis, the weight of evidence supporting a key role for RA is incontrovertible. PMID:22075477

  2. Homology model of human retinoic acid metabolising enzyme cytochrome P450 26A1 (CYP26A1): active site architecture and ligand binding.

    PubMed

    Gomaa, Mohamed Sayed; Yee, Sook Wah; Milbourne, Ceri Elizabeth; Barbera, Maria Chiara; Simons, Claire; Brancale, Andrea

    2006-08-01

    Homology models of cytochrome P450 RA1 (CYP26A1) were constructed using three human P450 structures, CYP2C8, CYP2C9 and CYP3A4 as templates for the model building. Using MOE software the lowest energy CYP26A1 model was then assessed for stereochemical quality and side chain environment. Further active site optimisation of the CYP26A1 model built using the CYP3A4 template was performed by molecular dynamics to generate a final CYP26A1 model. The natural substrate, all-trans-retinoic acid (atRA), and inhibitor R 15866, were docked into the model allowing further validation of the active site architecture. Using the docking studies structurally and functionally important residues were identified with subsequent characterisation of secondary structure. Multiple hydrophobic interactions, including the side chains of TRP112, PHE299, PHE222, PHE84, PHE374 and PRO371, are important for binding of atRA and R115866. Additional hydrogen bonding interactions were noted as follows: atRA-- C==O of the atRA carboxylate group and ARG86; R115866--benzothiazole nitrogen and the backbone NH of SER115.

  3. Teratogenicity of benzoic acid derivatives of retinoic acid in cultured mouse embryos.

    PubMed

    Goulding, E H; Jetten, A M; Abbott, B D; Pratt, R M

    1988-01-01

    Isotretinoin (13-cis-RA) is a human teratogen and mouse embryos exposed to 13-cis-RA in vivo exhibit many of the same defects as humans. Early postimplantation mouse embryos exposed to 13-cis-RA in culture exhibit developmental alterations of the visceral arches, similar to those seen after in vivo exposure. Certain benzoic acid derivatives of retinoic acid have been shown to possess activity equal to or greater than retinoic acid in several in vitro systems. This study examines the teratogenic effects of some of these retinoids on mouse embryos in vitro. Day 8 CD-1 mouse embryos were cultured for 48 hours in the presence of these benzoic acid derivatives. With the exception of Ro-15-0778, all compounds produced visceral arch malformations similar to those seen in embryos exposed to 13-cis-RA, but at dramatically different effective concentrations. Extremely low concentrations of the retinoic acid-related compounds tested appear to have detrimental effects on embryonic development and these compounds may be poor candidates for therapeutic use.

  4. Dominant negative retinoic acid receptor initiates tumor formation in mice

    PubMed Central

    Kupumbati, Tara S; Cattoretti, Giorgio; Marzan, Christine; Farias, Eduardo F; Taneja, Reshma; Mira-y-Lopez, Rafael

    2006-01-01

    Background Retinoic acid suppresses cell growth and promotes cell differentiation, and pharmacological retinoic acid receptor (RAR) activation is anti-tumorigenic. This begs the question of whether chronic physiological RAR activation by endogenous retinoids is likewise anti-tumorigenic. Results To address this question, we generated transgenic mice in which expression of a ligand binding defective dominant negative RARα (RARαG303E) was under the control of the mouse mammary tumor virus (MMTV) promoter. The transgene was expressed in the lymphoid compartment and in the mammary epithelium. Observation of aging mice revealed that transgenic mice, unlike their wild type littermates, developed B cell lymphomas at high penetrance, with a median latency of 40 weeks. MMTV-RARαG303E lymphomas were high grade Pax-5+, surface H+L Ig negative, CD69+ and BCL6- and cytologically and phenotypically resembled human adult high grade (Burkitt's or lymphoblastic) lymphomas. We postulated that mammary tumors might arise after a long latency period as seen in other transgenic models of breast cancer. We tested this idea by transplanting transgenic epithelium into the cleared fat pads of wild type hosts, thus bypassing lymphomagenesis. At 17 months post-transplantation, a metastatic mammary adenocarcinoma developed in one of four transplanted glands whereas no tumors developed in sixteen of sixteen endogenous glands with wild type epithelium. Conclusion These findings suggest that physiological RAR activity may normally suppress B lymphocyte and mammary epithelial cell growth and that global RAR inactivation is sufficient to initiate a stochastic process of tumor development requiring multiple transforming events. Our work makes available to the research community a new animal resource that should prove useful as an experimental model of aggressive sporadic lymphoma in immunologically uncompromised hosts. We anticipate that it may also prove useful as a model of breast cancer. PMID

  5. Dose Dependent Activation of Retinoic Acid-Inducible Gene-I Promotes Both Proliferation and Apoptosis Signals in Human Head and Neck Squamous Cell Carcinoma

    PubMed Central

    Yan, Ming; Zhu, Chao; Ye, Weimin; Zhu, Hanguang; Chen, Wantao; Zhang, Chenping; Zhang, Zhiyuan

    2013-01-01

    The retinoic-acid-inducible gene (RIG)-like receptor (RLR) family proteins are major pathogen reorganization receptors (PRR) responsible for detection of viral RNA, which initiates antiviral response. Here, we evaluated the functional role of one RLR family member, RIG-I, in human head and neck squamous cell carcinoma (HNSCC). RIG-I is abundantly expressed both in poorly-differentiated primary cancer and lymph node metastasis, but not in normal adjacent tissues. Activation of RIG-I by transfection with low dose of 5′-triphosphate RNA (3p-RNA) induces low levels of interferon and proinflammatory cytokines and promotes NF-κB- and Akt-dependent cell proliferation, migration and invasion. In contrast, activation of RIG-I by a high dose of 3p-RNA induces robust mitochondria-derived apoptosis accompanied by decreased activation of Akt, which is independent of the interferon and TNFα receptor, but can be rescued by over-expression of constitutively active Akt. Furthermore, co-immunoprecipitation experiments indicate that the CARD domain of RIG-I is essential for inducing apoptosis by interacting with caspase-9. Together, our results reveal a dual role of RIG-I in HNSCC through regulating activation of Akt, in which RIG-I activation by low-dose viral dsRNA increases host cell surviral, whereas higher level of RIG-I activation leads to apopotosis. These findings highlight the therapeutic potential of dsRNA mediated RIG-I activation in the treatment of HNSCC. PMID:23484008

  6. Retinoic acid from the meninges regulates cortical neuron generation.

    PubMed

    Siegenthaler, Julie A; Ashique, Amir M; Zarbalis, Konstantinos; Patterson, Katelin P; Hecht, Jonathan H; Kane, Maureen A; Folias, Alexandra E; Choe, Youngshik; May, Scott R; Kume, Tsutomu; Napoli, Joseph L; Peterson, Andrew S; Pleasure, Samuel J

    2009-10-30

    Extrinsic signals controlling generation of neocortical neurons during embryonic life have been difficult to identify. In this study we demonstrate that the dorsal forebrain meninges communicate with the adjacent radial glial endfeet and influence cortical development. We took advantage of Foxc1 mutant mice with defects in forebrain meningeal formation. Foxc1 dosage and loss of meninges correlated with a dramatic reduction in both neuron and intermediate progenitor production and elongation of the neuroepithelium. Several types of experiments demonstrate that retinoic acid (RA) is the key component of this secreted activity. In addition, Rdh10- and Raldh2-expressing cells in the dorsal meninges were either reduced or absent in the Foxc1 mutants, and Rdh10 mutants had a cortical phenotype similar to the Foxc1 null mutants. Lastly, in utero RA treatment rescued the cortical phenotype in Foxc1 mutants. These results establish RA as a potent, meningeal-derived cue required for successful corticogenesis.

  7. Ecto-alkaline phosphatase activity identified at physiological pH range on intact P19 and HL-60 cells is induced by retinoic acid.

    PubMed

    Scheibe, R J; Kuehl, H; Krautwald, S; Meissner, J D; Mueller, W H

    2000-01-01

    The activity of membrane-bound alkaline phosphatase (ALP) expressed on the external surface of cultured murine P19 teratocarcinoma and human HL-60 myeloblastic leukemia cells was studied at physiological pH using p-nitrophenylphosphate (pNPP) as substrate. The rate of substrate hydrolysis catalyzed by intact viable cells remained constant for eight successive incubations of 30 min and was optimal at micromolar substrate concentrations over the pH range 7.4-8.5. The value of apparent K(m) for pNPP in P19 and HL-60 cells was 120 microM. Hydrolytic activity of the ecto-enzyme at physiological pH decreased by the addition of levamisole, a specific and noncompetitive inhibitor of ALP (K(i) P19 = 57 microM; K(i) HL-60 = 50 microM). Inhibition of hydrolysis was reversed by removal of levamisole within 30 min. Retinoic acid (RA), which promotes the differentiation of P19 and HL-60 cells, induced levamisole-sensitive ecto-phosphohydrolase activity at pH 7.4. After its autophosphorylation by ecto-kinase activity, a 98-kDa membrane protein in P19 cells was found to be sensitive to ecto-ALP, and protein dephosphorylation increased after incubation of cells with RA for 24 h and 48 h. Orthovanadate, an inhibitor of all phosphatase activities, blocked the levamisole-sensitive dephosphorylation of the membrane phosphoproteins, while (R)-(-)-epinephrine reversed the effect by complexation of the inhibitor. The results demonstrate that the levamisole-sensitive phosphohydrolase activity on the cell surface is consistent with ecto-ALP activity degrading both physiological concentrations of exogenously added substrate and endogenous surface phosphoproteins under physiological pH conditions. The dephosphorylating properties of ecto-ALP are induced by RA, suggesting a specific function in differentiating P19 teratocarcinoma and HL-60 myeloblastic leukemia cells. PMID:10649440

  8. 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

  9. 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

  10. Cell type and gene-specific activity of the retinoid inverse agonist AGN 193109: divergent effects from agonist at retinoic acid receptor gamma in human keratinocytes.

    PubMed

    Thacher, S M; Nagpal, S; Klein, E S; Arefieg, T; Krasinski, G; DiSepio, D; Agarwal, C; Johnson, A; Eckert, R L; Chandraratna, R A

    1999-04-01

    Retinoids are important regulators of epithelial differentiation. AGN 193109 is a high-affinity antagonist and inverse agonist for the nuclear retinoic acid receptors (RARs). Paradoxically, both AGN 193109 and retinoid agonists inhibit the expression of the differentiation marker MRP-8 in normal human keratinocytes (NHKs). TTNPB, an RAR agonist, and AGN 193109 mutually antagonize MRP-8 inhibition at both mRNA and protein levels. We find that this antagonism, which is greatest at an AGN 193109:TTNPB ratio of about 10:1, is absent when either compound is in significant excess. The potent RARalpha-specific agonist, AGN 193836, has no effect on MRP-8 regulation. These data indicate that inverse agonists and agonists suppress MRP-8 in NHKs through RARgamma using distinct and mutually inhibitory mechanisms. The activity of AGN 193109 on MRP-8 is cell type specific. In differentiating ECE16-1 cervical cells, TTNPB inhibits while AGN 193109 induces MRP-8 mRNA levels. The effect of AGN 193109 on genes inhibited by retinoid agonists in NHKs is also selective; expression of the differentiation markers transglutaminase 1 and keratin 6 is not down-regulated by AGN 193109 whereas stromelysin-1 expression is suppressed. These results show a complex gene and cell context-specific interplay between agonist and inverse agonist for the regulation of gene expression.

  11. High affinity retinoic acid receptor antagonists: analogs of AGN 193109.

    PubMed

    Johnson, A T; Wang, L; Gillett, S J; Chandraratna, R A

    1999-02-22

    A series of high affinity retinoic acid receptor (RAR) antagonists were prepared based upon the known antagonist AGN 193109 (2). Introduction of various phenyl groups revealed a preference for substitution at the para-position relative to the meta-site. Antagonists with the highest affinities for the RARs possessed hydrophobic groups, however, the presence of polar functionality was also well tolerated.

  12. Expression of retinoic acid receptors in human endometrial carcinoma.

    PubMed

    Tanabe, Kojiro; Utsunomiya, Hiroki; Tamura, Mitsutoshi; Niikura, Hitoshi; Takano, Tadao; Yoshinaga, Kohsuke; Nagase, Satoru; Suzuki, Takashi; Ito, Kiyoshi; Matsumoto, Mitsuyo; Hayashi, Shin-ichi; Yaegashi, Nobuo

    2008-02-01

    The retinoids (vitamin A and its biologically active derivatives) are essential for the health and survival of the individual. Several studies have reported a strong rationale for the use of retinoids in cancer treatment and chemoprevention. It has been discovered that expression of retinoic acid receptor (RAR) beta is frequently silenced in epithelial carcinogenesis, which has led to the hypothesis that RAR beta could act as a tumor suppressor. However, the status of RAR beta in human endometrial carcinoma has not been examined. In the present study, we initially studied the effects of retinoic acid on cell proliferation and the expression of RAR alpha, RAR beta, and RAR gamma using AM580 (a RAR-specific agonist) in the Ishikawa endometrial cancer cell line. We also examined the expression of RAR in human eutopic endometrium (30 cases), endometrial hyperplasia (28 cases), and endometrial carcinoma (103 cases) using immunohistochemistry. Finally, we correlated these findings with the clinicopathological parameters. In vitro, cell growth was inhibited and RAR beta and RAR gamma mRNA was significantly induced by AM580, compared with vehicle controls, whereas RAR alpha mRNA was significantly attenuated by AM580, compared with vehicle. RAR beta was detected predominantly in endometrial hyperplasia, compared with endometrial carcinoma. No statistically significant correlation was obtained between the expression of any other RAR subtypes and clinicopathological parameters in human endometrial carcinoma. The results of our study demonstrate that AM580 inhibits cell growth and induces RAR beta mRNA expression in the Ishikawa cell line, and the expression level of RAR beta in endometrial carcinoma is significantly lower than that in endometrial hyperplasia. AM580 might therefore be considered as a potential treatment for endometrial carcinoma.

  13. 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

  14. Retinoic Acid Ameliorates Pancreatic Fibrosis and Inhibits the Activation of Pancreatic Stellate Cells in Mice with Experimental Chronic Pancreatitis via Suppressing the Wnt/β-Catenin Signaling Pathway

    PubMed Central

    Yin, Guojian; Fan, Yuting; Wu, Deqing; Qiu, Lei; Yu, Ge; Xing, Miao; Hu, Guoyong; Wang, Xingpeng; Wan, Rong

    2015-01-01

    Pancreatic fibrosis, a prominent feature of chronic pancreatitis (CP), induces persistent and permanent damage in the pancreas. Pancreatic stellate cells (PSCs) provide a major source of extracellular matrix (ECM) deposition during pancreatic injury, and persistent activation of PSCs plays a vital role in the progression of pancreatic fibrosis. Retinoic acid (RA), a retinoid, has a broad range of biological functions, including regulation of cell differentiation and proliferation, attenuating progressive fibrosis of multiple organs. In the present study, we investigated the effects of RA on fibrosis in experimental CP and cultured PSCs. CP was induced in mice by repetitive cerulein injection in vivo, and mouse PSCs were isolated and activated in vitro. Suppression of pancreatic fibrosis upon administration of RA was confirmed based on reduction of histological damage, α-smooth muscle actin (α-SMA) expression and mRNA levels of β-catenin, platelet-derived growth factor (PDGF)-Rβ transforming growth factor (TGF)-βRII and collagen 1α1 in vivo. Wnt 2 and β-catenin protein levels were markedly down-regulated, while Axin 2 expression level was up-regulated in the presence of RA, both in vivo and in vitro. Nuclear translation of β-catenin was significantly decreased following RA treatment, compared with cerulein-induced CP in mice and activated PSCs. Furthermore, RA induced significant PSC apoptosis, inhibited proliferation, suppressed TCF/LEF-dependent transcriptional activity and ECM production of PSC via down-regulation of TGFβRII, PDGFRβ and collagen 1α1 in vitro. These results indicate a critical role of the Wnt/β-catenin signaling pathway in RA-induced effects on CP and PSC regulation and support the potential of RA as a suppressor of pancreatic fibrosis in mice. PMID:26556479

  15. Retinoic Acid Ameliorates Pancreatic Fibrosis and Inhibits the Activation of Pancreatic Stellate Cells in Mice with Experimental Chronic Pancreatitis via Suppressing the Wnt/β-Catenin Signaling Pathway.

    PubMed

    Xiao, Wenqin; Jiang, Weiliang; Shen, Jie; Yin, Guojian; Fan, Yuting; Wu, Deqing; Qiu, Lei; Yu, Ge; Xing, Miao; Hu, Guoyong; Wang, Xingpeng; Wan, Rong

    2015-01-01

    Pancreatic fibrosis, a prominent feature of chronic pancreatitis (CP), induces persistent and permanent damage in the pancreas. Pancreatic stellate cells (PSCs) provide a major source of extracellular matrix (ECM) deposition during pancreatic injury, and persistent activation of PSCs plays a vital role in the progression of pancreatic fibrosis. Retinoic acid (RA), a retinoid, has a broad range of biological functions, including regulation of cell differentiation and proliferation, attenuating progressive fibrosis of multiple organs. In the present study, we investigated the effects of RA on fibrosis in experimental CP and cultured PSCs. CP was induced in mice by repetitive cerulein injection in vivo, and mouse PSCs were isolated and activated in vitro. Suppression of pancreatic fibrosis upon administration of RA was confirmed based on reduction of histological damage, α-smooth muscle actin (α-SMA) expression and mRNA levels of β-catenin, platelet-derived growth factor (PDGF)-Rβ transforming growth factor (TGF)-βRII and collagen 1α1 in vivo. Wnt 2 and β-catenin protein levels were markedly down-regulated, while Axin 2 expression level was up-regulated in the presence of RA, both in vivo and in vitro. Nuclear translation of β-catenin was significantly decreased following RA treatment, compared with cerulein-induced CP in mice and activated PSCs. Furthermore, RA induced significant PSC apoptosis, inhibited proliferation, suppressed TCF/LEF-dependent transcriptional activity and ECM production of PSC via down-regulation of TGFβRII, PDGFRβ and collagen 1α1 in vitro. These results indicate a critical role of the Wnt/β-catenin signaling pathway in RA-induced effects on CP and PSC regulation and support the potential of RA as a suppressor of pancreatic fibrosis in mice. PMID:26556479

  16. In vitro inhibition of promyelocytic leukemia/retinoic acid receptor-alpha (PML/RARalpha) expression and leukemogenic activity by DNA/LNA chimeric antisense oligos.

    PubMed

    Caprodossi, Sara; Galluzzi, Luca; Biagetti, Simona; Della Chiara, Giulia; Pelicci, Pier Giuseppe; Magnani, Mauro; Fanelli, Mirco

    2005-01-01

    Acute promyelocytic leukemia (APL) is a subtype of myeloid leukemia characterized by the chromosomal translocation t(15:17) that leads to the expression of promyelocytic leukemia/retinoic acid receptor-alpha (PML/ RARalpha) oncofusion protein. The block of differentiation at the promyelocytic stage of the blasts and their increased survival induced by PML/RARalpha are the principal biological features of the disease. Therapies based on pharmacological doses of retinoic acid (RA, 10(-6) M) are able to restore APL cell differentiation in most cases, but not to achieve complete hematological remission because retinoic acid resistance occurs in many patients. In order to elaborate alternative therapeutic approaches, we focused our attention on the use of antisense oligonucleotides as gene-specific drug directed to PML/RARalpha mRNA target. We used antisense molecules containing multiple locked nucleic acid (LNA) modifications. The LNAs are nucleotide analogues that are able to form duplexes with complementary DNA or RNA sequences with highly increased thermal stability and are resistant to 3'-exonuclease degradation in vitro. The DNA/LNA chimeric molecules were designed on the fusion sequence of PML and RARalpha genes to specifically target the oncofusion protein. Cell-free and in vitro experiments using U937-PR9-inducible cell line showed that DNA/LNA oligonucleotides were able to interfere with PML/RARalpha expression more efficiently than the corresponding unmodified DNA oligo. Moreover, the treatment of U937-PR9 cells with these chimeric antisense molecules was able to abrogate the block of differentiation induced by PML/RARalpha oncoprotein. These data suggest a possible application of oligonucleotides containing LNA in an antisense therapeutic strategy for APL.

  17. 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...

  18. Amyloid β inhibits retinoic acid synthesis exacerbating Alzheimer disease pathology which can be attenuated by an retinoic acid receptor α agonist.

    PubMed

    Goncalves, Maria B; Clarke, Earl; Hobbs, Carl; Malmqvist, Tony; Deacon, Robert; Jack, Julian; Corcoran, Jonathan P T

    2013-04-01

    The retinoic acid receptor (RAR) α system plays a key role in the adult brain, participating in the homeostatic control of synaptic plasticity, essential for memory function. Here we show that RARα signalling is down-regulated by amyloid beta (Aβ), which inhibits the synthesis of the endogenous ligand, retinoic acid (RA). This results in the counteraction of a variety of RARα-activated pathways that are key in the aetiopathology of Alzheimer's disease (AD) but which can be reversed by an RARα agonist. RARα signalling improves cognition in the Tg2576 mice, it has an anti-inflammatory effect and promotes Aβ clearance by increasing insulin degrading enzyme and neprilysin activity in both microglia and neurons. In addition, RARα signalling prevents tau phosphorylation. Therefore, stimulation of the RARα signalling pathway using a synthetic agonist, by both clearing Aβ and counteracting some of its toxic effects, offers therapeutic potential for the treatment of AD.

  19. Amyloid β inhibits retinoic acid synthesis exacerbating Alzheimer disease pathology which can be attenuated by an retinoic acid receptor α agonist

    PubMed Central

    Goncalves, Maria B; Clarke, Earl; Hobbs, Carl; Malmqvist, Tony; Deacon, Robert; Jack, Julian; Corcoran, Jonathan P T

    2013-01-01

    The retinoic acid receptor (RAR) α system plays a key role in the adult brain, participating in the homeostatic control of synaptic plasticity, essential for memory function. Here we show that RARα signalling is down-regulated by amyloid beta (Aβ), which inhibits the synthesis of the endogenous ligand, retinoic acid (RA). This results in the counteraction of a variety of RARα-activated pathways that are key in the aetiopathology of Alzheimer's disease (AD) but which can be reversed by an RARα agonist. RARα signalling improves cognition in the Tg2576 mice, it has an anti-inflammatory effect and promotes Aβ clearance by increasing insulin degrading enzyme and neprilysin activity in both microglia and neurons. In addition, RARα signalling prevents tau phosphorylation. Therefore, stimulation of the RARα signalling pathway using a synthetic agonist, by both clearing Aβ and counteracting some of its toxic effects, offers therapeutic potential for the treatment of AD. PMID:23379615

  20. Differential effects of retinoic acid and growth factors on osteoblastic markers and CD10/NEP activity in stromal-derived osteoblasts.

    PubMed

    Benayahu, D; Fried, A; Shamay, A; Cunningham, N; Blumberg, S; Wientroub, S

    1994-09-01

    The effects of retinoic acid (RA) on the expression of osteoblastic-related cell markers was examined. A marrow stromal osteogenic cell line, MBA-15, was analyzed by Northern blotting for the expression of bone matrix proteins. These cells constitutively express mRNA encoding for procollagen alpha 2 (I), osteonectin, osteopontin, biglycan, and alkaline phosphatase (ALK-P). Gene expression was unchanged in response to RA triggering for 24 hr. Furthermore, cell growth and enzymatic activities of ALK-P and neutral endopeptidase (CD10/NEP) were studied. These parameters were examined in MBA-15 and clonal populations representing different stages of differentiation. The cell's growth rate was unchanged, while ALK-P activity was greatly increased during the culture period under RA treatment in MBA-15 and in the clonal cell lines examined while CD10/NEP activity displayed a different pattern. MBA-15.4, a preosteoblast cell line, exhibited an inhibition in CD10/NEP activity at the beginning of the culture period, reaching basal level with time. This activity was greatly increased over control level in MBA-15.6, a mature stage of osteoblasts. Furthermore, the response of cell lines to various growth factors was tested subsequent to priming the cultures with RA. A synergistic effect was monitored for ALK-P activity in MBA-15.4 and MBA-15.6 cells under rh-bone morphogenic protein (BMP-2) and purified osteogenin (BMP-3), and an antagonist effect was measured when cells were exposed to transforming growth factor beta (TGF beta). Contrarily, BMP-2 and BMP-3 inhibited the CD10/NEP activity that had remained unchanged following priming of the cell with RA. Insulin-like growth factor I (IGF-I) and basic fibroblast growth factors (bFGF) did not affect either ALK-P nor CD10/NEP activities in both cloned cells. Cellular response to bone-seeking hormone, parathyroid hormone (PTH), and prostaglandin E2 (PGE2) was monitored by activation of intracellular cAMP. Treatment with RA caused a

  1. Binding of retinoic acid receptor heterodimers to DNA. A role for histones NH2 termini.

    PubMed

    Lefebvre, P; Mouchon, A; Lefebvre, B; Formstecher, P

    1998-05-15

    The retinoic acid signaling pathway is controlled essentially through two types of nuclear receptors, RARs and RXRs. Ligand dependent activation or repression of retinoid-regulated genes is dependent on the binding of retinoic acid receptor (RAR)/9-cis-retinoic acid receptor (RXR) heterodimers to retinoic acid response element (RARE). Although unliganded RXR/RAR heterodimers bind constitutively to DNA in vitro, a clear in vivo ligand-dependent occupancy of the RARE present in the RARbeta2 gene promoter has been reported (Dey, A., Minucci, S., and Ozato, K. (1994) Mol. Cell. Biol. 14, 8191-8201). Nucleosomes are viewed as general repressors of the transcriptional machinery, in part by preventing the access of transcription factors to DNA. The ability of hRXRalpha/hRARalpha heterodimers to bind to a nucleosomal template in vitro has therefore been examined. The assembly of a fragment from the RARbeta2 gene promoter, which contains a canonical DR5 RARE, into a nucleosome core prevented hRXRalpha/hRARalpha binding to this DNA, in conditions where a strong interaction is observed with a linear DNA template. However, histone tails removal by limited proteolysis and histone hyperacetylation yielded nucleosomal RAREs able to bind to hRXRalpha/hRARalpha heterodimers. These data establish therefore the role of histones NH2 termini as a major impediment to retinoid receptors access to DNA, and identify histone hyperacetylation as a potential physiological regulator of retinoid-induced transcription.

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

    PubMed

    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.

  3. Overproduction of bioactive retinoic acid in cells expressing disease-associated mutants of retinol dehydrogenase 12.

    PubMed

    Lee, Seung-Ah; Belyaeva, Olga V; Popov, Ivan K; Kedishvili, Natalia Y

    2007-12-01

    Retinol dehydrogenase 12 (RDH12) is an NADP(+)-dependent oxidoreductase that in vitro catalyzes the reduction of all-trans-retinaldehyde to all-trans-retinol or the oxidation of retinol to retinaldehyde depending on substrate and cofactor availability. Recent studies have linked the mutations in RDH12 to severe early-onset autosomal recessive retinal dystrophy. The biochemical basis of photoreceptor cell death caused by mutations in RDH12 is not clear because the physiological role of RDH12 is not yet fully understood. Here we demonstrate that, although bi-directional in vitro, in living cells, RDH12 acts exclusively as a retinaldehyde reductase, shifting the retinoid homeostasis toward the increased levels of retinol and decreased levels of bioactive retinoic acid. The retinaldehyde reductase activity of RDH12 protects the cells from retinaldehyde-induced cell death, especially at high retinaldehyde concentrations, and this protective effect correlates with the lower levels of retinoic acid in RDH12-expressing cells. Disease-associated mutants of RDH12, T49M and I51N, exhibit significant residual activity in vitro, but are unable to control retinoic acid levels in the cells because of their dramatically reduced affinity for NADPH and much lower protein expression levels. These results suggest that RDH12 acts as a regulator of retinoic acid biosynthesis and protects photoreceptors against overproduction of retinoic acid from all-trans-retinaldehyde, which diffuses into the inner segments of photoreceptors from illuminated rhodopsin. These results provide a novel insight into the mechanism of retinal degeneration associated with mutations in RDH12 and are consistent with the observation that RDH12-null mice are highly susceptible to light-induced retinal apoptosis in cone and rod photoreceptors.

  4. Usefulness of retinoic acid in the treatment of melasma.

    PubMed

    Pathak, M A; Fitzpatrick, T B; Kraus, E W

    1986-10-01

    Melasma is a circumscribed brown macular hypermelanosis of the areas of the face and neck that are exposed to light. Clinical trials with various depigmenting formulations containing hydroquinone were conducted to determine the ideal concentration of hydroquinone, retinoic acid, and corticosteroids for the treatment of melasma. The compounds were tested with and without the concomitant use of topical sunscreen preparations. Based on the results of the trials and our earlier clinical experience, we conclude that treatment of melasma should involve the following: avoidance of sun exposure, constant use of broad-spectrum sunscreens, and topical application of a cream or lotion containing 2% hydroquinone and 0.05% to 0.1% retinoic acid (tretinoin). Patients should suspend use of oral contraceptives and other agents that promote skin pigmentation. The monobenzyl ether of hydroquinone should never be used in melasma therapy.

  5. Have all-trans retinoic acid and arsenic trioxide replaced all-trans retinoic acid and anthracyclines in APL as standard of care.

    PubMed

    Iland, Harry J; Wei, Andrew; Seymour, John F

    2014-03-01

    Until recently, the standard of care in the treatment of APL has involved the combination of all-trans retinoic acid with anthracycline-based chemotherapy during both induction and consolidation. Additionally, the intensity of consolidation chemotherapy has evolved according to a universally accepted relapse-risk stratification algorithm based on the white cell and platelet counts at presentation. That standard of care is being challenged by the increasing incorporation of arsenic trioxide into front-line treatment protocols, based on two complementary observations. The first is the undoubted anti-leukaemic activity of arsenic trioxide as shown in the relapsed and refractory setting, and in the initial management of low- and intermediate-risk patients. The second is an improved understanding of the action of both all-trans retinoic acid and arsenic trioxide in mediating APL cell eradication, with increasing recognition that PML-RARA fusion protein degradation rather than direct induction of terminal differentiation is the primary mechanism for their ability to eliminate leukaemia initiating cells. As a result, we believe the standard of care for initial therapy in APL is shifting towards an all-trans retinoic acid plus arsenic trioxide-based approach, with additional chemotherapy reserved for patients with high-risk disease. PMID:24907016

  6. 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.

  7. Classical dendritic cells mediate fibrosis directly via the retinoic acid pathway in severe eye allergy

    PubMed Central

    Ahadome, Sarah D.; Mathew, Rose; Reyes, Nancy J.; Mettu, Priyatham S.; Cousins, Scott W.; Calder, Virginia L.; Saban, Daniel R.

    2016-01-01

    Fibrosis is a shared end-stage pathway to lung, liver, and heart failure. In the ocular mucosa (conjunctiva), fibrosis leads to blindness in trachoma, pemphigoid, and allergy. The indirect fibrogenic role of DCs via T cell activation and inflammatory cell recruitment is well documented. However, here we demonstrate that DCs can directly induce fibrosis. In the mouse model of allergic eye disease (AED), classical CD11b+ DCs in the ocular mucosa showed increased activity of aldehyde dehydrogenase (ALDH), the enzyme required for retinoic acid synthesis. In vitro, CD11b+ DC–derived ALDH was associated with 9-cis-retinoic acid ligation to retinoid x receptor (RXR), which induced conjunctival fibroblast activation. In vivo, stimulating RXR led to rapid onset of ocular mucosal fibrosis, whereas inhibiting ALDH activity in DCs or selectively depleting DCs markedly reduced fibrosis. Collectively, these data reveal a profibrotic ALDH-dependent pathway by DCs and uncover a role for DC retinoid metabolism. PMID:27595139

  8. 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

  9. 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

  10. In vitro effects of retinoic acid on mouse incisor development.

    PubMed

    Bloch-Zupan, A; Mark, M P; Weber, B; Ruch, J V

    1994-10-01

    The developing dentition is known to express the complete set of retinoic acid (RA) nuclear receptors and cytoplasmic RA-binding proteins (CRABPI and II), and RA is required for in vitro mouse molar morphogenesis, so the role of RA during in vitro mouse incisor development was investigated. Histological procedures, immunocytochemical detection of proliferating cells, immunofluorescence detection of laminin, and in situ hybridization with RNA probes for CRABPI and II were done on the tooth-germ cultures either in the presence or in the absence of RA. RA appeared to control initial morphogenesis, particularly the asymmetrical growth of the cervical loop, and to regulate required differential mitotic activity. RA seemed also to be involved in asymmetrical laminin deposition. The distribution of the CRABP gene transcripts was similar during in vivo and in vitro incisor development. However, CRABPI gene transcript distribution in the labial part of the epithelial loop was detected in vitro only in the presence of RA. A direct role of the CRABPs during tooth development is, however, unlikely because Ch55, a synthetic RA analogue that does not bind to CRABP, had the same effects as RA on in vitro incisor development. PMID:7741659

  11. Leukocyte Homing, Fate, and Function Are Controlled by Retinoic Acid

    PubMed Central

    Guo, Yanxia; Brown, Chrysothemis; Ortiz, Carla; Noelle, Randolph J.

    2015-01-01

    Although vitamin A was recognized as an “anti-infective vitamin” over 90 years ago, the mechanism of how vitamin A regulates immunity is only beginning to be understood. Early studies which focused on the immune responses in vitamin A-deficient (VAD) animals clearly demonstrated compromised immunity and consequently increased susceptibility to infectious disease. The active form of vitamin A, retinoic acid (RA), has been shown to have a profound impact on the homing and differentiation of leukocytes. Both pharmacological and genetic approaches have been applied to the understanding of how RA regulates the development and differentiation of various immune cell subsets, and how RA influences the development of immunity versus tolerance. These studies clearly show that RA profoundly impacts on cell- and humoral-mediated immunity. In this review, the early findings on the complex relationship between VAD and immunity are discussed as well as vitamin A metabolism and signaling within hematopoietic cells. Particular attention is focused on how RA impacts on T-cell lineage commitment and plasticity in various diseases. PMID:25540140

  12. Development of novel silicon-containing inverse agonists of retinoic acid receptor-related orphan receptors.

    PubMed

    Toyama, Hirozumi; Nakamura, Masaharu; Nakamura, Masahiko; Matsumoto, Yotaro; Nakagomi, Madoka; Hashimoto, Yuichi

    2014-03-15

    Retinoic acid receptor (RAR)-related orphan receptors (RORs) regulate a variety of physiological processes, including hepatic gluconeogenesis, lipid metabolism, circadian rhythm and immune function. The RAR agonist: all-trans retinoic acid was reported to be an RORβ inverse agonist, but no information is available regarding ROR activity of its synthetic analogue Am580. Therefore, we screened Am580 and some related tetramethyltetrahydronaphthalene derivatives and carried out structural development studies, including substitution of carbon atoms with silicon, with the aim of creating a potent ROR transcriptional inhibitor. The phenyl amide disila compound 22 showed the most potent ROR-inhibitory activity among the compounds examined. Its activity towards RORα, RORβ and RORγ was increased compared to that of Am580. The IC₅₀ values for RORα, RORβ and RORγ are 1.3, >10 and 4.5 μM, respectively.

  13. 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

  14. Retinoic acid stimulate differentiation of hippocampal stem cells into opsin expressing cells in vitro.

    PubMed

    Safari, M; Nobakht, M; Roshandel, N Rahbar; Ghazi, F; Joghataee, M T

    2009-09-01

    The results of several studies have demonstrated that cell differentiation influenced by derivatives of retinoic acid. To determine whether retinoic acid mediate the differentiation of neural stem cells we treated dissociated hippocampal stem cells with different concentrations of all trans or 9-cis retinoic acid and analyzed the effects on cell fate by specific monoclonal antibody for photoreceptors. Addition of exogenous retinoic acid caused a dose dependent specific in the elevation of the cell number that developed as photoreceptors in culture. Also results ofimmunohistochemical studies using monoclonal antibody demonstrated that the primary effect ofretinoic acid was to influence progenitor cells the developed as mature and immature photoreceptors. These results suggest that retinoic acid may play an important effect in the normal development of photoreceptor cells in vitro.

  15. 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

  16. The Role of Retinoic Acid (RA) in Spermatogonial Differentiation.

    PubMed

    Busada, Jonathan T; Geyer, Christopher B

    2016-01-01

    Retinoic acid (RA) directs the sequential, but distinct, programs of spermatogonial differentiation and meiotic differentiation that are both essential for the generation of functional spermatozoa. These processes are functionally and temporally decoupled, as they occur in distinct cell types that arise over a week apart, both in the neonatal and adult testis. However, our understanding is limited in terms of what cellular and molecular changes occur downstream of RA exposure that prepare differentiating spermatogonia for meiotic initiation. In this review, we describe the process of spermatogonial differentiation and summarize the current state of knowledge regarding RA signaling in spermatogonia. PMID:26559678

  17. Chemical modulation of chaperone-mediated autophagy by retinoic acid derivatives

    PubMed Central

    Anguiano, Jaime; Garner, Thomas P; Mahalingam, Murugesan; Das, Bhaskar C.; Gavathiotis, Evripidis; Cuervo, Ana Maria

    2013-01-01

    Chaperone-mediated autophagy (CMA) contributes to cellular quality control and the cellular response to stress through the selective degradation of cytosolic proteins in lysosomes. Decrease in CMA activity occurs in aging and in age-related disorders (for example, neurodegenerative diseases and diabetes). Although prevention of this age-dependent decline through genetic manipulation in mouse has proven beneficial, chemical modulation of CMA is not currently possible, due in part to the lack of information on the signaling mechanisms that modulate this pathway. In this work, we report that signaling through the retinoic acid receptor alpha (RARα) inhibits CMA and apply structure-based chemical design to develop synthetic derivatives of all-trans-retinoic acid (ATRA) to specifically neutralize this inhibitory effect. We demonstrate that chemical enhancement of CMA protects cells from oxidative stress and from proteotoxicity, supporting a potential therapeutic opportunity when reduced CMA contributes to cellular dysfunction and disease. PMID:23584676

  18. Identification of Apolipoprotein A-I as a Retinoic Acid-binding Protein in the Eye.

    PubMed

    Summers, Jody A; Harper, Angelica R; Feasley, Christa L; Van-Der-Wel, Hanke; Byrum, Jennifer N; Hermann, Marcela; West, Christopher M

    2016-09-01

    All-trans-retinoic acid may be an important molecular signal in the postnatal control of eye size. The goal of this study was to identify retinoic acid-binding proteins secreted by the choroid and sclera during visually guided ocular growth. Following photoaffinity labeling with all-trans-[11,12-(3)H]retinoic acid, the most abundant labeled protein detected in the conditioned medium of choroid or sclera had an apparent Mr of 27,000 Da. Following purification and mass spectrometry, the Mr 27,000 band was identified as apolipoprotein A-I. Affinity capture of the radioactive Mr 27,000 band by anti-chick apolipoprotein A-I antibodies confirmed its identity as apolipoprotein A-I. Photoaffinity labeling and fluorescence quenching experiments demonstrated that binding of retinoic acid to apolipoprotein A-I is 1) concentration-dependent, 2) selective for all-trans-retinoic acid, and 3) requires the presence of apolipoprotein A-I-associated lipids for retinoid binding. Expression of apolipoprotein A-I mRNA and protein synthesis were markedly up-regulated in choroids of chick eyes during the recovery from induced myopia, and apolipoprotein A-I mRNA was significantly increased in choroids following retinoic acid treatment. Together, these data suggest that apolipoprotein A-I may participate in a regulatory feedback mechanism with retinoic acid to control the action of retinoic acid on ocular targets during postnatal ocular growth.

  19. Identification of Apolipoprotein A-I as a Retinoic Acid-binding Protein in the Eye.

    PubMed

    Summers, Jody A; Harper, Angelica R; Feasley, Christa L; Van-Der-Wel, Hanke; Byrum, Jennifer N; Hermann, Marcela; West, Christopher M

    2016-09-01

    All-trans-retinoic acid may be an important molecular signal in the postnatal control of eye size. The goal of this study was to identify retinoic acid-binding proteins secreted by the choroid and sclera during visually guided ocular growth. Following photoaffinity labeling with all-trans-[11,12-(3)H]retinoic acid, the most abundant labeled protein detected in the conditioned medium of choroid or sclera had an apparent Mr of 27,000 Da. Following purification and mass spectrometry, the Mr 27,000 band was identified as apolipoprotein A-I. Affinity capture of the radioactive Mr 27,000 band by anti-chick apolipoprotein A-I antibodies confirmed its identity as apolipoprotein A-I. Photoaffinity labeling and fluorescence quenching experiments demonstrated that binding of retinoic acid to apolipoprotein A-I is 1) concentration-dependent, 2) selective for all-trans-retinoic acid, and 3) requires the presence of apolipoprotein A-I-associated lipids for retinoid binding. Expression of apolipoprotein A-I mRNA and protein synthesis were markedly up-regulated in choroids of chick eyes during the recovery from induced myopia, and apolipoprotein A-I mRNA was significantly increased in choroids following retinoic acid treatment. Together, these data suggest that apolipoprotein A-I may participate in a regulatory feedback mechanism with retinoic acid to control the action of retinoic acid on ocular targets during postnatal ocular growth. PMID:27402828

  20. Retinoic acid increases the sensitivity of the rat embryo fibroblast transformation assay.

    PubMed Central

    Halazonetis, T D; Daugherty, C; Leder, P

    1988-01-01

    The rat embryo fibroblast focus assay is used to evaluate the transforming potential of several oncogenes. The sensitivity of this assay increased fivefold when retinoic acid was added to tissue culture media. Retinoic acid probably acts by selectively inhibiting the proliferation of nontransformed cells. Images PMID:3380100

  1. 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.

  2. 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

  3. Characterization of retinoyl beta-glucuronide as a minor metabolite of retinoic acid in bile.

    PubMed Central

    Zile, M H; Schnoes, H K; DeLuca, H F

    1980-01-01

    Several metabolites detected in the bile of rats given radioactive retinoic acid were separated by liquid/gel partition chromatography and purified by high-pressure liquid chromatography. One of these metabolites was found to be sensitive to beta-D-glucuronidase, yielding both 13-cis- and all-trans-retinoic acid. It had the characteristic ultraviolet absorption spectrum of retinoic acid esters. Trimethylsilyl ether and acetyl derivatives of the methylated metabolite were prepared and examined by mass spectrometry. The resulting mass spectra established the structure to be retinoyl beta-glucuronide. Retinoyl glucuronide was rapidly excreted into the bile: the excretion was complete by 12 hr after the administration of retinoic acid. At this time the metabolite represented 12% of bile radioactivity (10% of dose). These observations confirm the existence of retinoyl glucuronide but demonstrate that it represents only one of several retinoic acid metabolites in bile. PMID:6932017

  4. Visualization of an endogenous retinoic acid gradient across embryonic development.

    PubMed

    Shimozono, Satoshi; Iimura, Tadahiro; Kitaguchi, Tetsuya; Higashijima, Shin-Ichi; Miyawaki, Atsushi

    2013-04-18

    In vertebrate development, the body plan is determined by primordial morphogen gradients that suffuse the embryo. Retinoic acid (RA) is an important morphogen involved in patterning the anterior-posterior axis of structures, including the hindbrain and paraxial mesoderm. RA diffuses over long distances, and its activity is spatially restricted by synthesizing and degrading enzymes. However, gradients of endogenous morphogens in live embryos have not been directly observed; indeed, their existence, distribution and requirement for correct patterning remain controversial. Here we report a family of genetically encoded indicators for RA that we have termed GEPRAs (genetically encoded probes for RA). Using the principle of fluorescence resonance energy transfer we engineered the ligand-binding domains of RA receptors to incorporate cyan-emitting and yellow-emitting fluorescent proteins as fluorescence resonance energy transfer donor and acceptor, respectively, for the reliable detection of ambient free RA. We created three GEPRAs with different affinities for RA, enabling the quantitative measurement of physiological RA concentrations. Live imaging of zebrafish embryos at the gastrula and somitogenesis stages revealed a linear concentration gradient of endogenous RA in a two-tailed source-sink arrangement across the embryo. Modelling of the observed linear RA gradient suggests that the rate of RA diffusion exceeds the spatiotemporal dynamics of embryogenesis, resulting in stability to perturbation. Furthermore, we used GEPRAs in combination with genetic and pharmacological perturbations to resolve competing hypotheses on the structure of the RA gradient during hindbrain formation and somitogenesis. Live imaging of endogenous concentration gradients across embryonic development will allow the precise assignment of molecular mechanisms to developmental dynamics and will accelerate the application of approaches based on morphogen gradients to tissue engineering and

  5. Retinoic acid deficiency alters second heart field formation.

    PubMed

    Ryckebusch, Lucile; Wang, Zengxin; Bertrand, Nicolas; Lin, Song-Chang; Chi, Xuan; Schwartz, Robert; Zaffran, Stéphane; Niederreither, Karen

    2008-02-26

    Retinoic acid (RA), the active derivative of vitamin A, has been implicated in various steps of cardiovascular development. The retinaldehyde dehydrogenase 2 (RALDH2) enzyme catalyzes the second oxidative step in RA biosynthesis and its loss of function creates a severe embryonic RA deficiency. Raldh2(-/-) knockout embryos fail to undergo heart looping and have impaired atrial and sinus venosus development. To understand the mechanism(s) producing these changes, we examined the contribution of the second heart field (SHF) to pharyngeal mesoderm, atria, and outflow tract in Raldh2(-/-) embryos. RA deficiency alters SHF gene expression in two ways. First, Raldh2(-/-) embryos exhibited a posterior expansion of anterior markers of the SHF, including Tbx1, Fgf8, and the Mlc1v-nlacZ-24/Fgf10 reporter transgene as well as of Islet1. This occurred at early somite stages, when cardiac defects became irreversible in an avian vitamin A-deficiency model, indicating that endogenous RA is required to restrict the SHF posteriorly. Explant studies showed that this expanded progenitor population cannot differentiate properly. Second, RA up-regulated cardiac Bmp expression levels at the looping stage. The contribution of the SHF to both inflow and outflow poles was perturbed under RA deficiency, creating a disorganization of the heart tube. We also investigated genetic cross-talk between Nkx2.5 and RA signaling by generating double mutant mice. Strikingly, Nkx2.5 deficiency was able to rescue molecular defects in the posterior region of the Raldh2(-/-) mutant heart, in a gene dosage-dependent manner. PMID:18287057

  6. Teratogenic effects of retinoic acid on neurulation in mice embryos.

    PubMed

    Nobakht, M; Zirak, A; Mehdizadeh, M; Tabatabaeei, P

    2006-02-21

    Retinoic acids (RA) are natural chemicals that exert a hormone-like activity and a variety of biological effects on early development of mouse. In this study, the probable teratogenic effects of RA on CNS have been investigated in pregnant mice (n = 20) divided into four groups: (1) untreated controls, (2) controls which received a single dose of DMSO, (3) a group that received 40 mg/kg, and (4) a group that received 60 mg/kg of all-trans RA in DMSO, respectively on the eighth day of gestation. Embryos whose dams had received 40 and 60 mg/kg doses of RA, showed malformations and decreased size. At 40 mg/kg dosage level, 50% of the embryos had closed neural tubes while at 60 mg/kg dosage level the neural tube failed to close. The neuroblast mantle layers were disorganized in the 40 mg/kg and even more in the 60 mg/kg exposed group compared to the controls. In mitosis, the density of chromatin was increased in the 60 mg/kg dose group. Compared to controls the 40 and 60 mg/kg dose groups of RA treated dams decreases in the luminal longitudinal and internal measures were observed. Also the thickness of ventricular, mantle and marginal layers was smaller. Wide intercellular spaces due to the degenerated cells at high doses of RA as well as an accumulation of intercellular fluid were observed. Therefore, the wedge shape of neuroepithelium was abolished, preventing the elevation of the neural wall.

  7. 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

  8. 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

  9. The retinoic acid derivative Ro 11-1430 in Acne vulgaris. A controlled multicenter trial against retinoic acid.

    PubMed

    Christiansen, J; Holm, P; Reymann, F

    1977-01-01

    In a double-blind controlled multicenter trial consisting of 257 patients with acne vulgaris an 8-week topical treatment with the retinoic acid derivative Ro 11-1430 (0.1% lotion) was compared with vitamin A acid (0.05% lotion) and the lotion alone (placebo). In reducing the number of comedones vitamin A acid was superior to Ro 11-1430, which was significantly better than placebo. The reduction in number of papules and pustules was not statistically significant on either treatment. Local side effects, i.e. erythema, desquamation, burning and pruritus occurred more frequently and were more severe on vitamin A acid than on Ro 11-1430 and placebo which did not differ. No correlation was found between incidence and severity of local reactions and therapeutic effect.

  10. Retinoic Acid and Histone Deacetylases Regulate Epigenetic Changes in Embryonic Stem Cells*

    PubMed Central

    Urvalek, Alison M.; Gudas, Lorraine J.

    2014-01-01

    All-trans-retinoic acid (RA) is a vitamin A metabolite that plays major roles in regulating stem cell differentiation and development. RA is the ligand of the retinoic acid receptor (RAR) family of transcription factors, which interact with retinoic acid response elements (RAREs) within target gene proximal promoters and enhancers. Although RA-mediated gene activation is well understood, less is known about the mechanisms for repression at RA-regulated genes. Using chromatin immunoprecipitation experiments, we show that in embryonic stem cells in the absence of RA, histone deacetylases (HDACs) differentially bind to various RAREs in proximal promoters or enhancer regions of RA-regulated genes; HDAC1, HDAC2, and HDAC3 bind at RAREs in the Hoxa1 and Cyp26a1 gene regulatory regions, whereas only HDAC1 binds at the RARβ2 RARE. shRNA knockdown of HDAC1, HDAC2, or HDAC3 differentially increases the deposition of the histone 3 lysine 27 acetylation (H3K27ac) epigenetic mark associated with increases in these three transcripts. Importantly, RA treatment differentially mediates the removal of HDACs from the Hoxa1, Cyp26a1, and RARβ2 genes and promotes the deposition of the H3K27ac mark at these genes. Overall, we show that HDACs differentially bind to RA-regulated genes to control key epigenetic marks involved in stem cell differentiation. PMID:24821725

  11. Treatment of recurrent malignant gliomas with 13-cis-retinoic acid naphthalene triazole.

    PubMed

    Jia, Pi-Feng; Gu, Wei-Ting; Zhang, Wei-Feng; Li, Feng

    2015-05-01

    Glioblastoma multiforme and anaplastic astrocytoma are challenges to clinical biologists at present. The patients with glioblastoma have median survival of less than 12 months, despite advances in radiotherapeutical, chemotherapeutical and conventional surgical modalities. Retinoic acids are known to effect in vitro proliferation, differentiation, and apoptosis in colon, prostate, lung, and leukemia cancers. Retinoids are known to have anti-proliferation, anti-migration, and anti-invasive activity against human malignant gliomas, suggesting that retinoids are suitable anticancer agents to inhibit progression of tumors. Recurrent malignant cerebral gliomas have been treated with ATRA and 13-cis RA. However, the side effects associated with the use of high doses of retinoic acid demand for some more potent derivative free from such effects. The present clinical trials are undertaken to investigate the clinical safety and possible efficacy of administering retinoic acid naphthalene triazole (RANT) to patients with recurrent malignant gliomas. The toxicities observed in the patients during RANT treatment were mild. These preliminary results suggest that RANT is more potent compared to RA against recurrent malignant gliomas.

  12. 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

  13. Upregulation of retinoic acid receptor-beta by the epidermal growth factor-receptor inhibitor PD153035 is not mediated by blockade of ErbB pathways.

    PubMed

    Grunt, Thomas W; Tomek, Katharina; Wagner, Renate; Puckmair, Klaudia; Kainz, Birgit; Rünzler, Dominik; Gaiger, Alexander; Köhler, Gottfried; Zielinski, Christoph C

    2007-06-01

    Inhibiting epidermal growth factor-receptor (ErbB-1) represents a powerful anticancer strategy. Activation of retinoid pathways is also in development for cancer treatment. Retinoic acid receptor-beta-the tumor suppressor and main retinoid mediator--is silenced in many tumors. The ErbB-1 inhibitor PD153035 cooperates with retinoic acid during growth inhibition and induces retinoic acid receptor-beta suggesting that ErbB-1 controls retinoic acid receptor-beta. However, here we demonstrate that ErbB pathways are not involved in PD153035-mediated retinoic acid receptor-beta-upregulation. PD153035 inhibits ErbB-1-phosphorylation, whereas its derivative EBE-A22 is inactive. Yet both inhibit cell growth and upregulate retinoic acid receptor-beta in ErbB-1-overexpressing (MDA-MB-468), moderately expressing (OVCAR-3), ErbB-1-negative (MDA-MB-453) or ErbB-negative cells (CEM, Jurkat). Both bind DNA, whereas the closely related ErbB-1 inhibitors AG1478 and ZD1839, which are inactive on retinoic acid receptor-beta, do not significantly bind DNA. None of the other ErbB-1/ErbB-2 inhibitors tested (RG-14620, LFM-A12, AG879, AG825) affect retinoic acid receptor-beta. PD153035 decreases methylation of the retinoic acid receptor-beta2 promoter. In OVCAR-3, it stimulates dislodgement of histone deacetylase 1 from the promoter and acetylation of histones H3 and H4. Consequently, PD153035 facilitates recruitment of RNA polymerase II to the promoter and stimulates transcriptional activity. Moreover, PD153035 increases the retinoic acid receptor-beta mRNA half-life. No other retinoid receptor, nor estrogen receptor-alpha, nor RASSF1A is upregulated by PD153035. Thus PD153035 induces retinoic acid receptor-beta by ErbB-independent transcriptional and post-transcriptional mechanisms. This report highlights a triple action for an ErbB-1 inhibitor (ErbB-1 inhibition, DNA intercalation, retinoic acid receptor-beta-induction). Such multitargeting drugs bear great potential for cancer

  14. 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.

  15. Dominant negative mutant of retinoic acid receptor alpha inhibits retinoic acid-induced P19 cell differentiation by binding to DNA.

    PubMed

    Costa, S L; McBurney, M W

    1996-05-25

    Retinoic acid (RA) is a potent inducer of P19 cell differentiation. RA activity is thought to be mediated by nuclear RA receptors (RARs), transcription factors whose activity is dependent on RA. There are three RARs called alpha, beta, and gamma. We created truncated versions of the three RARs and compared their activities as inhibitors of RA-mediated gene transcription and of P19 cell differentiation. Only mutants of the RAR alpha were inhibitory in these assays. A mutant of RAR alpha carrying a 10-amino-acid insert was able to heterodimerize with RXRbeta or with the normal RAR alpha and the inhibitory activity of this mutant was dependent on an intact DNA binding domain. We conclude that dominant negative mutants of RAR alpha act by heterodimerizing with RXRs or RARs and binding to RA response elements on DNA, thereby preventing binding of the normal receptors to those sites. PMID:8635515

  16. Dynamics and precision in retinoic acid morphogen gradients

    PubMed Central

    Schilling, Thomas F.; Nie, Qing; Lander, Arthur D.

    2013-01-01

    Summary Retinoic acid (RA) regulates many cellular behaviors during embryonic development and adult homeostasis. Like other morphogens, RA forms gradients through the use of localized sources and sinks, feedback, and interactions with other signals; this has been particularly well studied in the context of hindbrain segmentation in vertebrate embryos. Yet, as a small lipophilic molecule derived from a dietary source—vitamin A—RA differs markedly from better-studied polypeptide morphogens in its mechanisms of transport, signaling, and removal. Computational models suggest that the distinctive features of RA gradients make them particularly robust to large perturbations. Such features include combined positive and negative feedback effects via intracellular fatty acid binding proteins and RA-degrading enzymes. Here, we discuss how these features, together with feedback interactions among RA target genes, help enable RA to specify multiple, accurate pattern elements in the developing hindbrain, despite operating in an environment of high cellular and biochemical uncertainty and noise. PMID:23266215

  17. Identification and characterization of a functional retinoic acid/thyroid hormone-response element upstream of the human insulin gene enhancer.

    PubMed Central

    Clark, A R; Wilson, M E; London, N J; James, R F; Docherty, K

    1995-01-01

    A deletion analysis of the human insulin gene extending to 2 kb upstream of the transcription start site provided evidence of regulatory sequences located upstream of the insulin-linked polymorphic region (ILPR). Within this ILPR-distal region is a sequence (Ink, for insulin kilobase upstream) which contains three potential nuclear hormone-receptor half-sites, closely matching the consensus sequence AGGTCA. These sequences are arranged as a palindromic element with zero spacing over-lapping a direct repeat with 2 bp spacing. The Ink sequence was used in electrophoretic mobility-shift assays within nuclear extracts from COS-7 cells overexpressing the vitamin D, thyroid hormone or retinoic acid receptors, or from an insulin-expressing hamster cell line, HIT-T15. These studies suggest that the insulin-expressing cell line contains thyroid hormone and retinoic acid receptors at least, and that these receptors are able to recognize the Ink sequence. Three copies of the Ink sequence were placed upstream of the thymidine kinase promoter and firefly luciferase reporter gene. In COS-7 cells expressing the appropriate nuclear hormone receptor, this construct was responsive to both thyroid hormone (18-fold) and all-trans-retinoic acid (31-fold). In HIT-T15 cells the same construct responded to all-trans-retinoic acid, but not to thyroid hormone. Within the context of a 2 kb insulin gene fragment, the Ink sequence was shown to be activated by retinoic acid and by the retinoic acid receptor, but acted as a negative element in the presence of both retinoic acid and the retinoic acid receptor. Mutagenesis studies demonstrated that the palindromic sequence was important for the retinoic acid response, and for binding of complexes containing retinoic acid receptor. In human islets of Langerhans, retinoic acid was shown to stimulate insulin mRNA levels. These results demonstrate that a functional nuclear hormone-receptor-response element is located upstream of the human ILPR. As

  18. Synergistic activation of retinoic acid (RA)-responsive genes and induction of embryonal carcinoma cell differentiation by an RA receptor {alpha} (RAR{alpha})-, RAR{beta}-, or RAR{gamma}-selective ligand in combination with retinoid Z receptor-specific ligand

    SciTech Connect

    Roy, B.; Taneja, R.; Chambon, P.

    1995-12-01

    This research indicates thatn retinoic acid receptor (RAR)-retinoid X receptor (RXR) heterodimers activate transcription of RA-responsive genes and induce cell differentiation of P19 and F9 cells in a ligand-dependent manner. 43 refs., 4 figs., 2 tabs.

  19. Zebrafish fetal alcohol syndrome model: effects of ethanol are rescued by retinoic acid supplement

    PubMed Central

    Marrs, James A.; Clendenon, Sherry G.; Ratcliffe, Don R.; Fielding, Stephen M.; Liu, Qin; Bosron, William F.

    2009-01-01

    This study was designed to develop a zebrafish experimental model to examine defects in retinoic acid signaling caused by embryonic ethanol. Retinoic acid deficiency may be a causative factor leading to a spectrum of birth defects classified as fetal alcohol spectrum disorder (FASD). Experimental support for this hypothesis using Xenopus showed that effects of treatment with ethanol could be partially rescued by adding retinoids during ethanol treatment. Previous studies show that treating zebrafish embryos during gastrulation and somitogenesis stages with a pathophysiological concentration of ethanol (100 mM) produces effects that are characteristic features of FASD. We found that treating zebrafish embryos with retinoic acid at a low concentration (10−9 M) and 100 mM ethanol during gastrulation and somitogenesis stages significantly rescued a spectrum of defects produced by treating embryos with 100 mM ethanol alone. The rescue phenotype that we observed was quantitatively more similar to embryos treated with 10−9 M retinoic acid alone (retinoic acid toxicity) than to untreated or 100 mM ethanol treated embryos. Retinoic acid rescues defects caused by 100 mM ethanol treatment during gastrulation and somitogenesis stages that include early gastrulation cell movements (anterior-posterior axis), craniofacial cartilage formation and ear development. Morphological evidence also suggests that other characteristic features of FASD (e. g., neural axis patterning) are rescued by retinoic acid supplement. PMID:20036484

  20. Retinoic acid receptor alpha is associated with tamoxifen resistance in breast cancer

    PubMed Central

    Johansson, Henrik J.; Sanchez, Betzabe C.; Mundt, Filip; Forshed, Jenny; Kovacs, Aniko; Panizza, Elena; Hultin-Rosenberg, Lina; Lundgren, Bo; Martens, Ulf; Máthé, Gyöngyvér; Yakhini, Zohar; Helou, Khalil; Krawiec, Kamilla; Kanter, Lena; Hjerpe, Anders; Stål, Olle; Linderholm, Barbro K.; Lehtiö, Janne

    2013-01-01

    About one-third of oestrogen receptor alpha-positive breast cancer patients treated with tamoxifen relapse. Here we identify the nuclear receptor retinoic acid receptor alpha as a marker of tamoxifen resistance. Using quantitative mass spectrometry-based proteomics, we show that retinoic acid receptor alpha protein networks and levels differ in a tamoxifen-sensitive (MCF7) and a tamoxifen-resistant (LCC2) cell line. High intratumoural retinoic acid receptor alpha protein levels also correlate with reduced relapse-free survival in oestrogen receptor alpha-positive breast cancer patients treated with adjuvant tamoxifen solely. A similar retinoic acid receptor alpha expression pattern is seen in a comparable independent patient cohort. An oestrogen receptor alpha and retinoic acid receptor alpha ligand screening reveals that tamoxifen-resistant LCC2 cells have increased sensitivity to retinoic acid receptor alpha ligands and are less sensitive to oestrogen receptor alpha ligands compared with MCF7 cells. Our data indicate that retinoic acid receptor alpha may be a novel therapeutic target and a predictive factor for oestrogen receptor alpha-positive breast cancer patients treated with adjuvant tamoxifen. PMID:23868472

  1. 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

  2. Retinoic acid regulation by CYP26 in vertebrate lens regeneration

    PubMed Central

    Thomas, Alvin G; Henry, Jonathan J

    2014-01-01

    Xenopus laevis is among the few species that are capable of fully regenerating a lost lens de novo. This occurs upon removal of the lens, when secreted factors from the retina are permitted to reach the cornea epithelium and trigger it to form a new lens. Although many studies have investigated the retinal factors that initiate lens regeneration, relatively little is known about what factors support this process and make the cornea competent to form a lens. We presently investigate the role of Retinoic acid (RA) signaling in lens regeneration in Xenopus. RA is a highly important morphogen during vertebrate development, including the development of various eye tissues, and has been previously implicated in several regenerative processes as well. For instance, Wolffian lens regeneration in the newt requires active RA signaling. In contrast, we provide evidence here that lens regeneration in Xenopus actually depends on the attenuation of RA signaling, which is regulated by the RA-degrading enzyme CYP26. Using RTPCR we examined the expression of RA synthesis and metabolism related genes within ocular tissues. We found expression of aldh1a1, aldh1a2, and aldh1a3, as well as cyp26a1 and cyp26b1 in both normal and regenerating corneal tissue. On the other hand, cyp26c1 does not appear to be expressed in either control or regenerating corneas, but it is expressed in the lens. Additionally in the lens, we found expression of aldh1a1 and aldh1a2, but not aldh1a3. Using an inhibitor of CYP26, and separately using exogenous retinoids, as well as RA signaling inhibitors, we demonstrate that CYP26 activity is necessary for lens regeneration to occur. We also find using phosphorylated Histone H3 labeling that CYP26 antagonism reduces cell proliferation in the cornea, and using qPCR we find that exogenous retinoids alter the expression of putative corneal stem cell markers. Furthermore, the Xenopus cornea is composed of an outer layer and inner basal epithelium, as well as a

  3. 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.

  4. Phytanic acid and docosahexaenoic acid increase the metabolism of all-trans-retinoic acid and CYP26 gene expression in intestinal cells.

    PubMed

    Lampen, A; Meyer, S; Nau, H

    2001-10-31

    Retinoids are essential for growth and cell differentiation of epithelial tissues. The effects of the food compounds phytol, the phytol metabolite phytanic acid, and the fatty acid docosahexaenoic acid (DHA) on the retinoid signaling pathway in intestinal cells were studied. Phytol inhibited the formation of all-trans-retinoic acid (RA) from dietary retinol in intestinal cells. Phytanic acid, a known retinoic X receptor (RXRalpha) and peroxisome proliferator activating receptor (PPARalpha) activator, also activated PPARdelta, and to a lesser degree PPARgamma, in a transactivation assay. Phytanic acid had no effect on intestinal RA hydroxylase CYP26 (also named P450RAI) gene expression and metabolism of all-trans-RA in intestinal Caco-2 cells. However, in combination with retinoic acid receptor (RAR)-ligands (all-trans-RA or synthetic Am580) phytanic acid enhanced the induction of CYP26 and RA-metabolism in comparison to treatments with all-trans-RA or Am580 alone. Also treatment with DHA did not affect CYP26 gene expression and RA-metabolism but cotreatment of the cells with DHA and all-trans-RA or Am580 enhanced the induction of CYP26, in comparison to the induction caused by all-trans-RA or Am580 alone. This study indicates that food compounds such as phytanic acid and DHA that are RXR-agonists and have an impact on intestinal CYP26 gene expression and metabolism of all-trans-RA in intestinal cells.

  5. Retinoic acid inhibits induction of c-Jun protein by ultraviolet radiation that occurs subsequent to activation of mitogen-activated protein kinase pathways in human skin in vivo.

    PubMed

    Fisher, G J; Talwar, H S; Lin, J; Lin, P; McPhillips, F; Wang, Z; Li, X; Wan, Y; Kang, S; Voorhees, J J

    1998-03-15

    Human skin is exposed daily to solar ultraviolet (UV) radiation. UV induces the matrix metalloproteinases collagenase, 92-kD gelatinase, and stromelysin, which degrade skin connective tissue and may contribute to premature skin aging (photoaging). Pretreatment of skin with all-trans retinoic acid (tRA) inhibits UV induction of matrix metalloproteinases. We investigated upstream signal transduction pathways and the mechanism of tRA inhibition of UV induction of matrix metalloproteinases in human skin in vivo. Exposure of human skin in vivo to low doses of UV activated EGF receptors, the GTP-binding regulatory protein p21Ras, and stimulated mitogen-activated protein (MAP) kinases, extracellular signal-regulated kinase (ERK), c-Jun amino-terminal kinase (JNK), and p38. Both JNK and p38 phosphorylated, and thereby activated transcription factors c-Jun and activating transcription factor 2 (ATF-2), which bound to the c-Jun promoter and upregulated c-Jun gene expression. Elevated c-Jun, in association with constitutively expressed c-Fos, formed increased levels of transcription factor activator protein (AP) 1, which is required for transcription of matrix metalloproteinases. Pretreatment of human skin with tRA inhibited UV induction of c-Jun protein and, consequently, AP-1. c-Jun protein inhibition occurred via a posttranscriptional mechanism, since tRA did not inhibit UV induction of c-Jun mRNA. These data demonstrate, for the first time, activation of MAP kinase pathways in humans in vivo, and reveal a novel posttranscriptional mechanism by which tRA antagonizes UV activation of AP-1 by inhibiting c-Jun protein induction. Inhibition of c-Jun induction likely contributes to the previously reported prevention by tRA of UV induction of AP-1-regulated matrix-degrading metalloproteinases in human skin.

  6. 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

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

    PubMed

    Chen, Pei-Jen; 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

  8. 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...

  9. Marked resistance of RAR gamma-deficient mice to the toxic effects of retinoic acid.

    PubMed

    Look, J; Landwehr, J; Bauer, F; Hoffmann, A S; Bluethmann, H; LeMotte, P

    1995-07-01

    Excessive intake of retinol or of retinoic acid causes a syndrome of characteristic toxic effects known as hypervitaminosis A. To test the role of the nuclear retinoic acid receptor (RAR gamma) in this process we produced mice with a targeted disruption of the RAR gamma gene and examined toxic effects of repeated doses of retinoic acid and two other synthetic retinoids, Ro 15-1570 and Ro 40-6055. Surprisingly, homozygous mutant mice were resistant to fourfold higher doses of retinoic acid than wild-type mice as well as to elevated doses of the synthetic retinoids, indicating that RAR gamma may have a major role in mediating retinoid toxicity, a finding that possibly has practical implications for reducing the toxicity of synthetic retinoids in clinical use.

  10. Effects of synthetic retinoids and retinoic acid isomers on the expression of alkaline phosphatase in F9 teratocarcinoma cells.

    PubMed

    Gianni, M; Zanotta, S; Terao, M; Garattini, S; Garattini, E

    1993-10-15

    Expression of ALP in F9 teratocarcinoma cells is induced by all-trans retinoic acid (ATRA) (Gianni' et al., Biochem. J. 274: 673-678, 1991). The specific ligand for retinoic acid related receptors (RXRs), 9-cis retinoic acid (9-cis RA), and three synthetic analogs binding to the alpha, beta and gamma forms of the retinoic acid receptors (RARs), AM580, CD2019, and CD437, were used to study their effects on alkaline phosphatase (ALP) enzymatic activity and mRNA levels. At concentrations close to the Kd for their respective receptors, 9-cis RA, AM580 (the RAR alpha agonist) and CD437 (the RAR gamma agonist) clearly upregulate the expression of the ALP gene, whereas the effect of CD2019 (the RAR beta agonist) is very modest. A specific inhibitor of the RAR alpha, Ro 41-5253, completely blocks the induction of ALP triggered by AM580, while it has minor effects on the upregulation caused by ATRA, 9-cis RA, CD437 and CD2019. The induction of ALP observed with the various retinoids is inhibited by the contemporaneous treatment with dibutyryl cAMP. The levels of the RAR alpha and gamma transcripts are unaltered, while RAR beta mRNAs are induced by ATRA, AM580, CD437 and to a lower extent by 9-cis RA and CD2019.

  11. 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

  12. Retinoic Acid-Related Orphan Receptors (RORs): Regulatory Functions in Immunity, Development, Circadian Rhythm, and Metabolism

    PubMed Central

    Cook, Donald N.; Kang, Hong Soon; Jetten, Anton M.

    2015-01-01

    In this overview, we provide an update on recent progress made in understanding the mechanisms of action, physiological functions, and roles in disease of retinoic acid related orphan receptors (RORs). We are particularly focusing on their roles in the regulation of adaptive and innate immunity, brain function, retinal development, cancer, glucose and lipid metabolism, circadian rhythm, metabolic and inflammatory diseases and neuropsychiatric disorders. We also summarize the current status of ROR agonists and inverse agonists, including their regulation of ROR activity and their therapeutic potential for management of various diseases in which RORs have been implicated. PMID:26878025

  13. Recessive and dominant mutations in retinoic acid receptor beta in cases with microphthalmia and diaphragmatic hernia.

    PubMed

    Srour, Myriam; Chitayat, David; Caron, Véronique; Chassaing, Nicolas; Bitoun, Pierre; Patry, Lysanne; Cordier, Marie-Pierre; Capo-Chichi, José-Mario; Francannet, Christine; Calvas, Patrick; Ragge, Nicola; Dobrzeniecka, Sylvia; Hamdan, Fadi F; Rouleau, Guy A; Tremblay, André; Michaud, Jacques L

    2013-10-01

    Anophthalmia and/or microphthalmia, pulmonary hypoplasia, diaphragmatic hernia, and cardiac defects are the main features of PDAC syndrome. Recessive mutations in STRA6, encoding a membrane receptor for the retinol-binding protein, have been identified in some cases with PDAC syndrome, although many cases have remained unexplained. Using whole-exome sequencing, we found that two PDAC-syndrome-affected siblings, but not their unaffected sibling, were compound heterozygous for nonsense (c.355C>T [p.Arg119(∗)]) and frameshift (c.1201_1202insCT [p.Ile403Serfs(∗)15]) mutations in retinoic acid receptor beta (RARB). Transfection studies showed that p.Arg119(∗) and p.Ile403Serfs(∗)15 altered RARB had no transcriptional activity in response to ligands, confirming that the mutations induced a loss of function. We then sequenced RARB in 15 subjects with anophthalmia and/or microphthalmia and at least one other feature of PDAC syndrome. Surprisingly, three unrelated subjects with microphthalmia and diaphragmatic hernia showed de novo missense mutations affecting the same codon; two of the subjects had the c.1159C>T (Arg387Cys) mutation, whereas the other one carried the c.1159C>A (p.Arg387Ser) mutation. We found that compared to the wild-type receptor, p.Arg387Ser and p.Arg387Cys altered RARB induced a 2- to 3-fold increase in transcriptional activity in response to retinoic acid ligands, suggesting a gain-of-function mechanism. Our study thus suggests that both recessive and dominant mutations in RARB cause anophthalmia and/or microphthalmia and diaphragmatic hernia, providing further evidence of the crucial role of the retinoic acid pathway during eye development and organogenesis.

  14. 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

  15. Early retinoic acid deprivation in developing zebrafish results in microphthalmia.

    PubMed

    Le, Hong-Gam T; Dowling, John E; Cameron, D Joshua

    2012-09-01

    Vitamin A deficiency causes impaired vision and blindness in millions of children around the world. Previous studies in zebrafish have demonstrated that retinoic acid (RA), the acid form of vitamin A, plays a vital role in early eye development. The objective of this study was to describe the effects of early RA deficiency by treating zebrafish with diethylaminobenzaldehyde (DEAB), a potent inhibitor of the enzyme retinaldehyde dehydrogenase (RALDH) that converts retinal to RA. Zebrafish embryos were treated for 2 h beginning at 9 h postfertilization. Gross morphology and retinal development were examined at regular intervals for 5 days after treatment. The optokinetic reflex (OKR) test, visual background adaptation (VBA) test, and the electroretinogram (ERG) were performed to assess visual function and behavior. Early treatment of zebrafish embryos with 100 μM DEAB (9 h) resulted in reduced eye size, and this microphthalmia persisted through larval development. Retinal histology revealed that DEAB eyes had significant developmental abnormalities but had relatively normal retinal lamination by 5.5 days postfertilization. However, the fish showed neither an OKR nor a VBA response. Further, the retina did not respond to light as measured by the ERG. We conclude that early deficiency of RA during eye development causes microphthalmia as well as other visual defects, and that timing of the RA deficiency is critical to the developmental outcome.

  16. 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

  17. A Mollusk Retinoic Acid Receptor (RAR) Ortholog Sheds Light on the Evolution of Ligand Binding

    PubMed Central

    Gutierrez-Mazariegos, Juliana; Nadendla, Eswar Kumar; Lima, Daniela; Pierzchalski, Keely; Jones, Jace W.; Kane, Maureen; Nishikawa, Jun-Ichi; Hiromori, Youhei; Nakanishi, Tsuyoshi; Santos, Miguel M.; Castro, L. Filipe C.; Bourguet, William

    2014-01-01

    Nuclear receptors are transcription factors that regulate networks of target genes in response to small molecules. There is a strong bias in our knowledge of these receptors because they were mainly characterized in classical model organisms, mostly vertebrates. Therefore, the evolutionary origins of specific ligand-receptor couples still remain elusive. Here we present the identification and characterization of a retinoic acid receptor (RAR) from the mollusk Nucella lapillus (NlRAR). We show that this receptor specifically binds to DNA response elements organized in direct repeats as a heterodimer with retinoid X receptor. Surprisingly, we also find that NlRAR does not bind all-trans retinoic acid or any other retinoid we tested. Furthermore, NlRAR is unable to activate the transcription of reporter genes in response to stimulation by retinoids and to recruit coactivators in the presence of these compounds. Three-dimensional modeling of the ligand-binding domain of NlRAR reveals an overall structure that is similar to vertebrate RARs. However, in the ligand-binding pocket (LBP) of the mollusk receptor, the alteration of several residues interacting with the ligand has apparently led to an overall decrease in the strength of the interaction with the ligand. Accordingly, mutations of NlRAR at key positions within the LBP generate receptors that are responsive to retinoids. Altogether our data suggest that, in mollusks, RAR has lost its affinity for all-trans retinoic acid, highlighting the evolutionary plasticity of its LBP. When put in an evolutionary context, our results reveal new structural and functional features of nuclear receptors validated by millions of years of evolution that were impossible to reveal in model organisms. PMID:25116705

  18. Retinoic Acid Receptor-Mediated Induction of ABCA1 in Macrophages

    PubMed Central

    Costet, Philippe; Lalanne, Florent; Gerbod-Giannone, Marie C.; Molina, Jennifer R.; Fu, Xuan; Lund, Erik G.; Gudas, Lorraine J.; Tall, Alan R.

    2003-01-01

    ABCA1, the mutant molecule in Tangier Disease, mediates efflux of cellular cholesterol to apoA-I and is induced by liver X receptor (LXR)/retinoid X receptor (RXR) transcription factors. Retinoic acid receptor (RAR) activators (all-trans-retinoic acid [ATRA] and TTNPB) were found to increase ATP-binding cassette transporter 1 (ABCA1) mRNA and protein in macrophages. In cellular cotransfection assays, RARγ/RXR activated the human ABCA1 promoter, via the same direct repeat 4 (DR4) promoter element as LXR/RXR. Chromatin immunoprecipitation analysis in macrophages confirmed the binding of RARγ/RXR to the ABCA1 promoter DR4 element in the presence of ATRA, with weaker binding of RARα/RXR, and no binding of RARβ/RXR. However, in macrophages from RARγ−/− mice, TTNPB still induced ABCA1, in association with marked upregulation of RARα, suggesting that high levels of RARα can compensate for the absence of RARγ. Dose-response experiments with ATRA in mouse primary macrophages showed that other LXR target genes were weakly induced (ABCG1 and SREBP-1c) or not induced (apoE and LXRα). The more specific RAR activator TTNPB did not induce SREBP-1c in mouse primary macrophages or liver. These studies indicate a direct role of RARγ/RXR in induction of macrophage ABCA1. PMID:14560020

  19. Crystal structure of human aldehyde dehydrogenase 1A3 complexed with NAD+ and retinoic acid

    PubMed Central

    Moretti, Andrea; Li, Jianfeng; Donini, Stefano; Sobol, Robert W.; Rizzi, Menico; Garavaglia, Silvia

    2016-01-01

    The aldehyde dehydrogenase family 1 member A3 (ALDH1A3) catalyzes the oxidation of retinal to the pleiotropic factor retinoic acid using NAD+. The level of ALDHs enzymatic activity has been used as a cancer stem cell marker and seems to correlate with tumour aggressiveness. Elevated ALDH1A3 expression in mesenchymal glioma stem cells highlights the potential of this isozyme as a prognosis marker and drug target. Here we report the first crystal structure of human ALDH1A3 complexed with NAD+ and the product all-trans retinoic acid (REA). The tetrameric ALDH1A3 folds into a three domain-based architecture highly conserved along the ALDHs family. The structural analysis revealed two different and coupled conformations for NAD+ and REA that we propose to represent two snapshots along the catalytic cycle. Indeed, the isoprenic moiety of REA points either toward the active site cysteine, or moves away adopting the product release conformation. Although ALDH1A3 shares high sequence identity with other members of the ALDH1A family, our structural analysis revealed few peculiar residues in the 1A3 isozyme active site. Our data provide information into the ALDH1As catalytic process and can be used for the structure-based design of selective inhibitors of potential medical interest. PMID:27759097

  20. 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

  1. 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

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

    2011-12-01

    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.

  2. Retinoic acid attenuates O2-induced inhibition of lung septation.

    PubMed

    Veness-Meehan, Kathleen A; Pierce, Richard A; Moats-Staats, Billie M; Stiles, Alan D

    2002-11-01

    Exposure of the newborn lung to hyperoxia is associated with impaired alveolar development. In newborn rats exposed to hyperoxia and studied at day 14 of life, retinoic acid (RA) treatment improved survival and increased lung collagen but did not improve alveolar development. To determine whether RA treatment during exposure to hyperoxia results in late improvement in alveolarization, we treated newborn rats with RA and hyperoxia from day 3 to day 14 and then weaned O2 to room air by day 20, and studied the animals on day 42. O2-exposed animals had larger mean lung volumes, larger alveoli, and decreased gas-exchange tissue relative to air-exposed animals, whereas RA-treated O2-exposed animals were not statistically different from air-exposed controls. Relative to control animals, elastin staining at day 14 was decreased in hyperoxia-exposed lung independent of RA treatment, and, at day 42, elastin staining was similar in all treatment groups. At day 14, elastin gene expression was similar in all treatment groups, whereas at day 42 lung previously exposed to hyperoxia showed increased elastin signal independent of RA treatment. These results indicate that RA treatment during hyperoxia exposure promotes septal formation without evidence of effects on elastin gene expression after 4 wk of recovery. PMID:12376350

  3. 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

  4. Retinoic acid regulates anterior-posterior patterning within the lateral plate mesoderm of Xenopus.

    PubMed

    Deimling, Steven J; Drysdale, Thomas A

    2009-10-01

    The lateral plate mesoderm (LPM) lines the body cavities, gives rise to the heart and circulatory system and is responsible for patterning the underlying endoderm. We describe gene expression domains within the lateral plate mesoderm of the neurula stage Xenopus embryo that demonstrate a marked anterior posterior pattern in that tissue. FoxF1 and Nkx-2.5 are expressed in the anterior LPM, Hand1 in the middle and Xsal-1 in the posterior LPM. Since retinoic acid is known to pattern many tissues during development, and RALDH2, the enzyme primarily responsible for retinoic acid synthesis, is expressed in the anterior and dorsal LPM, we hypothesized that retinoic acid is necessary for correct patterning of the LPM. Exposure to exogenous retinoic acid during neurulation led to an expansion of the anterior and middle expression domains and a reduction of the posterior domain whereas exposure to a retinoic acid antagonist resulted in smaller anterior and middle expression domains. Furthermore, inhibition of RALDH2, which should decrease endogenous RA levels, caused a reduction of anterior domains indicating that endogenous RA is necessary for regulating their size. After altering retinoic acid signaling in a temporally restricted window, the displaced anterior-posterior pattern is maintained until gut looping, as demonstrated by permanently altered Hand1, FoxF1, xHoxC-10, and Pitx2 expression domains. We conclude that the broad expression domains of key transcription factors demonstrate a novel anterior-posterior pattern within the LPM and that retinoic acid can regulate the size of these domains in a coordinated manner.

  5. 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...

  6. Modulation of human stratum corneum properties by salicylic acid and all-trans-retinoic acid.

    PubMed

    Piérard-Franchimont, C; Goffin, V; Piérard, G E

    1998-01-01

    Topical all-trans-retinoic acid (RA) has been reported to decrease the in vivo skin response to sodium lauryl sulfate (SLS). The converse was also shown with a synergistic effect of RA following prior applications of SLS. The reason for such effects is not clear. We employed measures of transepidermal water loss (TEWL), squamometry and sequential corneosurfametry to explore the protective activity of a 0.05% RA cream at the level of the stratum corneum. Nonionic oil-in-water emulsions with or without 5% salicylic acid (SA) served as test product references. Data indicated that the RA formulation was responsible for a stochastic impairment in the TEWL and for an increased intercorneocyte cohesion. SA and the unmedicated emulsion did not lead to similar TEWL changes. The squamometry test proved to be very sensitive to disclose the effects of SA and RA without, however, allowing to distinguish the difference in the physiological processes involved. The corneosurfametry bioassay did not show any protection or synergistic effect between RA or SA and SLS challenge on the stratum corneum. This is in contrast to a previous work showing a positive protective effect afforded by retinol against SLS. The combined effects of irritant compounds affecting the stratum corneum are complex. The precise reason for some of their biological consequences remains a conundrum. On balance, products such as SA and RA do not appear to afford protection or impairment to a surfactant challenge at the level of the stratum corneum. PMID:9885411

  7. Modulation of human stratum corneum properties by salicylic acid and all-trans-retinoic acid.

    PubMed

    Piérard-Franchimont, C; Goffin, V; Piérard, G E

    1998-01-01

    Topical all-trans-retinoic acid (RA) has been reported to decrease the in vivo skin response to sodium lauryl sulfate (SLS). The converse was also shown with a synergistic effect of RA following prior applications of SLS. The reason for such effects is not clear. We employed measures of transepidermal water loss (TEWL), squamometry and sequential corneosurfametry to explore the protective activity of a 0.05% RA cream at the level of the stratum corneum. Nonionic oil-in-water emulsions with or without 5% salicylic acid (SA) served as test product references. Data indicated that the RA formulation was responsible for a stochastic impairment in the TEWL and for an increased intercorneocyte cohesion. SA and the unmedicated emulsion did not lead to similar TEWL changes. The squamometry test proved to be very sensitive to disclose the effects of SA and RA without, however, allowing to distinguish the difference in the physiological processes involved. The corneosurfametry bioassay did not show any protection or synergistic effect between RA or SA and SLS challenge on the stratum corneum. This is in contrast to a previous work showing a positive protective effect afforded by retinol against SLS. The combined effects of irritant compounds affecting the stratum corneum are complex. The precise reason for some of their biological consequences remains a conundrum. On balance, products such as SA and RA do not appear to afford protection or impairment to a surfactant challenge at the level of the stratum corneum.

  8. All-Trans-Retinoic Acid Enhances Mitochondrial Function in Models of Human Liver.

    PubMed

    Tripathy, Sasmita; Chapman, John D; Han, Chang Y; Hogarth, Cathryn A; Arnold, Samuel L M; Onken, Jennifer; Kent, Travis; Goodlett, David R; Isoherranen, Nina

    2016-05-01

    All-trans-retinoic acid (atRA) is the active metabolite of vitamin A. The liver is the main storage organ of vitamin A, but activation of the retinoic acid receptors (RARs) in mouse liver and in human liver cell lines has also been shown. AlthoughatRA treatment improves mitochondrial function in skeletal muscle in rodents, its role in modulating mitochondrial function in the liver is controversial, and little data are available regarding the human liver. The aim of this study was to determine whetheratRA regulates hepatic mitochondrial activity.atRA treatment increased the mRNA and protein expression of multiple components of mitochondrialβ-oxidation, tricarboxylic acid (TCA) cycle, and respiratory chain. Additionally,atRA increased mitochondrial biogenesis in human hepatocytes and in HepG2 cells with and without lipid loading based on peroxisome proliferator activated receptor gamma coactivator 1αand 1βand nuclear respiratory factor 1 mRNA and mitochondrial DNA quantification.atRA also increasedβ-oxidation and ATP production in HepG2 cells and in human hepatocytes. Knockdown studies of RARα, RARβ, and PPARδrevealed that the enhancement of mitochondrial biogenesis andβ-oxidation byatRA requires peroxisome proliferator activated receptor delta. In vivo in mice,atRA treatment increased mitochondrial biogenesis markers after an overnight fast. Inhibition ofatRA metabolism by talarozole, a cytochrome P450 (CYP) 26 specific inhibitor, increased the effects ofatRA on mitochondrial biogenesis markers in HepG2 cells and in vivo in mice. These studies show thatatRA regulates mitochondrial function and lipid metabolism and that increasingatRA concentrations in human liver via CYP26 inhibition may increase mitochondrial biogenesis and fatty acidβ-oxidation and provide therapeutic benefit in diseases associated with mitochondrial dysfunction. PMID:26921399

  9. Depletion of Retinoic Acid Receptors Initiates a Novel Positive Feedback Mechanism that Promotes Teratogenic Increases in Retinoic Acid

    PubMed Central

    D'Aniello, Enrico; Rydeen, Ariel B.; Anderson, Jane L.; Mandal, Amrita; Waxman, Joshua S.

    2013-01-01

    Normal embryonic development and tissue homeostasis require precise levels of retinoic acid (RA) signaling. Despite the importance of appropriate embryonic RA signaling levels, the mechanisms underlying congenital defects due to perturbations of RA signaling are not completely understood. Here, we report that zebrafish embryos deficient for RA receptor αb1 (RARαb1), a conserved RAR splice variant, have enlarged hearts with increased cardiomyocyte (CM) specification, which are surprisingly the consequence of increased RA signaling. Importantly, depletion of RARαb2 or concurrent depletion of RARαb1 and RARαb2 also results in increased RA signaling, suggesting this effect is a broader consequence of RAR depletion. Concurrent depletion of RARαb1 and Cyp26a1, an enzyme that facilitates degradation of RA, and employment of a novel transgenic RA sensor line support the hypothesis that the increases in RA signaling in RAR deficient embryos are the result of increased embryonic RA coupled with compensatory RAR expression. Our results support an intriguing novel mechanism by which depletion of RARs elicits a previously unrecognized positive feedback loop that can result in developmental defects due to teratogenic increases in embryonic RA. PMID:23990796

  10. 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

  11. Bidirectional CLOCK/BMAL1-dependent circadian gene regulation by retinoic acid in vitro

    SciTech Connect

    Shirai, Hidenori; Oishi, Katsutaka; Ishida, Norio . E-mail: n.ishida@aist.go.jp

    2006-12-15

    A central circadian clock located in the suprachiasmatic nucleus (SCN) of the mammalian hypothalamus entrains peripheral clocks through both neural and humoral factors. Although candidates for entrainment factors have been described, their details remain obscure. Here, we screened ligands for nuclear receptors that affect CLOCK/BMAL1-dependent transactivation of the mouse Period1 (mPer1) gene in NIH3T3 cells. We found that retinoic acids (RAs) significantly up-regulate mPer1 expression in an E-box-dependent manner. We also found that RAs up-regulate the expression of other E-box-dependent circadian genes such as mPer2, arginine vasopressin (mAVP), and peroxisome proliferator-activated receptor {alpha} (mPPAR{alpha}). Surprisingly, the effect of RAs on CLOCK/BMAL1 (E-box)-dependent mRNA expression was bidirectional and depended on the presence of exogenous retinoic acid receptor {alpha} (RAR{alpha}). These results suggest that RAs regulate the CLOCK/BMAL1-dependent transcription of circadian genes in a complex manner.

  12. Neural differentiation of pluripotent mouse embryonal carcinoma cells by retinoic acid: inhibitory effect of serum.

    PubMed

    Pacherník, J; Bryja, V; Esner, M; Kubala, L; Dvorák, P; Hampl, A

    2005-01-01

    In both embryonal carcinoma (EC) and embryonic stem (ES) cells, the differentiation pathway entered after treatment with retinoic acid (RA) varies as it is based upon different conditions of culture. This study employs mouse EC cells P19 to investigate the effects of serum on RA-induced neural differentiation occurring in a simplified monolayer culture. Cell morphology and expression of lineage-specific molecular markers document that, while non-neural cell types arise after treatment with RA under serum-containing conditions, in chemically defined serum-free media RA induces massive neural differentiation in concentrations of 10(-9) M and higher. Moreover, not only neural (Mash-1) and neuroectodermal (Pax-6), but also endodermal (GATA-4, alpha-fetoprotein) genes are expressed at early stages of differentiation driven by RA under serum-free conditions. Furthermore, as determined by the luciferase reporter assay, the presence or absence of the serum does not affect the activity of the retinoic acid response element (RARE). Thus, mouse EC cells are able to produce neural cells upon exposure to RA even without culture in three-dimensional embryoid bodies (EBs). However, in contrast to standard EBs-involving protocol(s), neural differentiation in monolayer only takes place when complex signaling from serum factors is avoided. This simple and efficient strategy is proposed to serve as a basis for neurodifferentiation studies in vitro. PMID:15717849

  13. 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.

  14. Retinoic acid and retinoid receptors: potential chemopreventive and therapeutic role in cervical cancer.

    PubMed

    Abu, Jafaru; Batuwangala, Madu; Herbert, Karl; Symonds, Paul

    2005-09-01

    Retinoids are natural and synthetic derivatives of vitamin A, which can be obtained from animal products (milk, liver, beef, fish oils, and eggs) and vegetables (carrots, mangos, sweet potatoes, and spinach). Retinoids regulate various important cellular functions in the body through specific nuclear retinoic-acid receptors and retinoid-X receptors, which are encoded by separate genes. Retinoic-acid receptors specifically bind tretinoin and alitretinoin, whereas retinoid-X receptors bind only alitretinoin. Retinoids have long been established as crucial for several essential life processes-healthy growth, vision, maintenance of tissues, reproduction, metabolism, tissue differentiation (normal, premalignant cells, and malignant cells), haemopoiesis, bone development, spermatogenesis, embryogenesis, and overall survival. Therefore, deficiency of vitamin A can lead to various unwanted biological effects. Several experimental and epidemiological studies have shown the antiproliferative activity of retinoids and their potential use in cancer treatment and chemoprevention. Emerging clinical trials have shown the chemotherapeutic and chemopreventive potential of retinoids in cancerous and precancerous conditions of the uterine cervix. In this review, we explore the potential chemopreventive and therapeutic roles of retinoids in preinvasive and invasive cervical neoplasia.

  15. Characterization of cDNAs encoding the chick retinoic acid receptor gamma 2 and preferential distribution of retinoic acid receptor gamma transcripts during chick skin development.

    PubMed

    Michaille, J J; Blanchet, S; Kanzler, B; Garnier, J M; Dhouailly, D

    1994-12-01

    Retinoic acid receptors alpha, beta and gamma (RAR alpha, beta and gamma) are ligand-inductible transcriptional activators which belong to the steroid/thyroid hormone receptor superfamily. At least two major isoforms (1 and 2) of each RAR arise by differential use of two promoters and alternative splicing. In mouse, the three RAR genes are expressed in stage- and tissue-specific patterns during embryonic development. In order to understand the role of the different RARs in chick, RAR gamma 2 cDNAs were isolated from an 8.5-day (stage 35 of Hamburger and Hamilton) chick embryo skin library. The deduced chick RAR gamma 2 amino acid sequence displays uncommon features such as 21 specific amino acid replacements, 12 of them being clustered in the amino-terminal region (domains A2 and B), and a truncated acidic carboxy-terminal region (F domain). However, the pattern of RAR gamma expression in chick embryo resembles that reported in mouse, particularly in skin where RAR gamma expression occurs in both the dermal and epidermal layers at the beginning of feather formation, and is subsequently restricted to the differentiating epidermal cells. Northern blot analysis suggests that different RAR gamma isoforms could be successively required during chick development.

  16. Retinoic acid regulates the development of a gut homing precursor for intestinal dendritic cells

    PubMed Central

    Zeng, Ruizhu; Oderup, Cecilia; Yuan, Robert; Lee, Mike; Habtezion, Aida; Hadeiba, Husein; Butcher, Eugene C

    2012-01-01

    The vitamin A metabolite retinoic acid (RA) regulates intestinal immune responses through immunomodulatory actions on intestinal dendritic cells (DCs) and lymphocytes. Here, we show that retinoic acid also controls the generation of gut-tropic migratory DC precursors, referred to as pre-mucosal DCs (pre-μDCs). Pre-μDCs express the gut trafficking receptor α4β7 and home preferentially to the intestines. They develop in the bone marrow, can differentiate into CCR9+ plasmacytoid DCs as well as conventional DCs (cDCs), but preferentially give rise to CD103+ intestinal cDCs. Generation of pre-μDCs in vivo in the bone marrow or in vitro is regulated by RA and retinoic acid receptor α signaling. The frequency of pre-μDCs is reduced in vitamin A-deficient animals and in animals treated with retinoic acid receptor inhibitors. The results define a novel vitamin A-dependent, retinoic-acid-regulated developmental sequence for dendritic cells and identify a targeted precursor for CD103+ cDCs in the gut. PMID:23235743

  17. Role of Acinus in Regulating Retinoic Acid-Responsive Gene Pre-mRNA Splicing

    PubMed Central

    Wang, Fang; Soprano, Kenneth J.; Soprano, Dianne Robert

    2014-01-01

    Acinus-S’ is a co-repressor for retinoic acid receptor (RAR)-dependent gene transcription and has been suggested to be involved in RNA processing. In this study the role of Acinus isoforms in regulating pre-mRNA splicing was explored using in vivo splicing assays. Both Acinus-L and Acinus-S’, with the activity of Acinus-L higher than that of Acinus-S’, increase the splicing of a retinoic acid (RA)-responsive minigene containing a weak 5′ splice site but not a RA-responsive minigene containing a strong 5′ splice site. RA treatment further enhances the splicing of the weak 5′ splice site by Acinus in a dose- and time-dependent manner, suggesting a RA-dependent activity in addition to a RA-independent activity of Acinus. The RA-independent effect of Acinus occurs to varying degrees using minigene constructs containing several different promoters while the RA-dependent splicing activity of Acinus is specific for transcripts derived from the minigene driven by a RA response element (RARE)-containing promoter. This suggests that the ligand-dependent splicing activity of Acinus is related to the RA-activated RAR bound to the RARE. The RRM domain is necessary for the RA-dependent splicing activity of Acinus and the RA-independent splicing activity of Acinus is repressed by RNPS1. Importantly, measurement of the splicing of endogenous human RARβ and Bcl-x in vivo demonstrates that Acinus stimulates the use of the weaker alternative 5′ splice site of these two genes in a RA-dependent manner for RARβ and a RA-independent manner for Bcl-x. Taken together, these studies demonstrate that Acinus functions in both RAR-dependent splicing and RAR-dependent transcription. PMID:25205379

  18. Physiological insights into all-trans-retinoic acid biosynthesis

    PubMed Central

    Napoli, Joseph L.

    2011-01-01

    All-trans-retinoic acid (atRA) provides essential support to diverse biological systems and physiological processes. Epithelial differentiation and its relationship to cancer and embryogenesis have typified intense areas of interest into atRA function. Recently, however, interest in atRA action in the nervous system, the immune system, energy balance and obesity has increased considerably, especially concerning postnatal function. atRA action depends on atRA biosynthesis: defects in retinoid-dependent processes increasingly relate to defects in atRA biogenesis. Considerable evidence indicates that physiological atRA biosynthesis occurs via a regulated process, consisting of a complex interaction of retinoid binding-proteins and retinoid recognizing enzymes. An accrual of biochemical, physiological and genetic data have identified specific functional outcomes for the retinol dehydrogenases, RDH1, RDH10, and DHRS9, as physiological catalysts of the first step in atRA biosynthesis, and for the retinal dehydrogenases RALDH1, RALDH2, and RALDH3, as catalysts of the second and irreversible step. Each of these enzymes associates with explicit biological processes mediated by atRA. Redundancy occurs, but seems limited. Cumulative data supports a model of interactions among these enzymes with retinoid binding-proteins, with feedback regulation and/or control by atRA via modulating gene expression of multiple participants. The ratio apo-CRBP1/holo-CRBP1 participates by influencing retinol flux into and out of storage as retinyl esters, thereby modulating substrate to support atRA biosynthesis. atRA biosynthesis requires presence of both an RDH and an RALDH: conversely, absence of one isozyme of either step does not indicate lack of atRA biosynthesis at the site. PMID:21621639

  19. Microbiota and bile acid profiles in retinoic acid-primed mice that exhibit accelerated liver regeneration

    PubMed Central

    Liu, Hui-Xin; Hu, Ying; Wan, Yu-Jui Yvonne

    2016-01-01

    Background & Aims All-trans Retinoic acid (RA) regulates hepatic lipid and bile acid homeostasis. Similar to bile acid (BA), RA accelerates partial hepatectomy (PHx)-induced liver regeneration. Because there is a bidirectional regulatory relationship between gut microbiota and BA synthesis, we examined the effect of RA in altering the gut microbial population and BA composition and established their relationship with hepatic biological processes during the active phases of liver regeneration. Methods C57BL/6 mice were treated with RA orally followed by 2/3 PHx. The roles of RA in shifting gut microbiota and BA profiles as well as hepatocyte metabolism and proliferation were studied. Results RA-primed mice exhibited accelerated hepatocyte proliferation revealed by higher numbers of Ki67-positive cells compared to untreated mice. Firmicutes and Bacteroidetes phyla dominated the gut microbial community (>85%) in both control and RA-primed mice after PHx. RA reduced the ratio of Firmicutes to Bacteroidetes, which was associated with a lean phenotype. Consistently, RA-primed mice lacked transient lipid accumulation normally found in regenerating livers. In addition, RA altered BA homeostasis and shifted BA profiles by increasing the ratio of hydrophilic to hydrophobic BAs in regenerating livers. Accordingly, metabolic regulators fibroblast growth factor 21, Sirtuin1, and their downstream targets AMPK and ERK1/2 were more robustly activated in RA-primed than unprimed regenerating livers. Conclusions Priming mice with RA resulted in a lean microbiota composition and hydrophilic BA profiles, which were associated with facilitated metabolism and enhanced cell proliferation. PMID:26701854

  20. Substrate Specificity and Ligand Interactions of CYP26A1, the Human Liver Retinoic Acid Hydroxylase

    PubMed Central

    Thatcher, Jayne E.; Buttrick, Brian; Shaffer, Scott A.; Shimshoni, Jakob A.; Goodlett, David R.; Nelson, Wendel L.

    2011-01-01

    All-trans-retinoic acid (atRA) is the active metabolite of vitamin A. atRA is also used as a drug, and synthetic atRA analogs and inhibitors of retinoic acid (RA) metabolism have been developed. The hepatic clearance of atRA is mediated primarily by CYP26A1, but design of CYP26A1 inhibitors is hindered by lack of information on CYP26A1 structure and structure-activity relationships of its ligands. The aim of this study was to identify the primary metabolites of atRA formed by CYP26A1 and to characterize the ligand selectivity and ligand interactions of CYP26A1. On the basis of high-resolution tandem mass spectrometry data, four metabolites formed from atRA by CYP26A1 were identified as 4-OH-RA, 4-oxo-RA, 16-OH-RA and 18-OH-RA. 9-cis-RA and 13-cis-RA were also substrates of CYP26A1. Forty-two compounds with diverse structural properties were tested for CYP26A1 inhibition using 9-cis-RA as a probe, and IC50 values for 10 inhibitors were determined. The imidazole- and triazole-containing inhibitors [S-(R*,R*)]-N-[4-[2-(dimethylamino)-1-(1H-imidazole-1-yl)propyl]-phenyl]2-benzothiazolamine (R116010) and (R)-N-[4-[2-ethyl-1-(1H-1,2,4-triazol-1-yl)butyl]phenyl]-2-benzothiazolamine (R115866) were the most potent inhibitors of CYP26A1 with IC50 values of 4.3 and 5.1 nM, respectively. Liarozole and ketoconazole were significantly less potent with IC50 values of 2100 and 550 nM, respectively. The retinoic acid receptor (RAR) γ agonist CD1530 was as potent an inhibitor of CYP26A1 as ketoconazole with an IC50 of 530 nM, whereas the RARα and RARβ agonists tested did not significantly inhibit CYP26A1. The pan-RAR agonist 4-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1-propenyl]benzoic acid and the peroxisome proliferator-activated receptor ligands rosiglitazone and pioglitazone inhibited CYP26A1 with IC50 values of 3.7, 4.2, and 8.6 μM, respectively. These data demonstrate that CYP26A1 has high ligand selectivity but accepts structurally related nuclear

  1. Retinoic acid and meiosis induction in adult versus embryonic gonads of medaka

    PubMed Central

    Adolfi, Mateus C.; Herpin, Amaury; Regensburger, Martina; Sacquegno, Jacopo; Waxman, Joshua S.; Schartl, Manfred

    2016-01-01

    In vertebrates, one of the first recognizable sex differences in embryos is the onset of meiosis, known to be regulated by retinoic acid (RA) in mammals. We investigated in medaka a possible meiotic function of RA during the embryonic sex determination (SD) period and in mature gonads. We found RA mediated transcriptional activation in germ cells of both sexes much earlier than the SD stage, however, no such activity during the critical stages of SD. In adults, expression of the RA metabolizing enzymes indicates sexually dimorphic RA levels. In testis, RA acts directly in Sertoli, Leydig and pre-meiotic germ cells. In ovaries, RA transcriptional activity is highest in meiotic oocytes. Our results show that RA plays an important role in meiosis induction and gametogenesis in adult medaka but contrary to common expectations, not for initiating the first meiosis in female germ cells at the SD stage. PMID:27677591

  2. Dynamic and combinatorial control of gene expression by nuclear retinoic acid receptors (RARs)

    PubMed Central

    Rochette-Egly, Cécile; Germain, Pierre

    2009-01-01

    Nuclear retinoic acid receptors (RARs) are transcriptional regulators controlling the expression of specific subsets of genes in a ligand-dependent manner. The basic mechanism for switching on transcription of cognate target genes involves RAR binding at specific response elements and a network of interactions with coregulatory protein complexes, the assembly of which is directed by the C-terminal ligand-binding domain of RARs. In addition to this scenario, new roles for the N-terminal domain and the ubiquitin-proteasome system recently emerged. Moreover, the functions of RARs are not limited to the regulation of cognate target genes, as they can transrepress other gene pathways. Finally, RARs are also involved in nongenomic biological activities such as the activation of translation and of kinase cascades. Here we will review these mechanisms, focusing on how kinase signaling and the proteasome pathway cooperate to influence the dynamics of RAR transcriptional activity. PMID:19471584

  3. Opposite effects of the acute promyelocytic leukemia PML-retinoic acid receptor alpha (RAR alpha) and PLZF-RAR alpha fusion proteins on retinoic acid signalling.

    PubMed Central

    Ruthardt, M; Testa, U; Nervi, C; Ferrucci, P F; Grignani, F; Puccetti, E; Grignani, F; Peschle, C; Pelicci, P G

    1997-01-01

    Fusion proteins involving the retinoic acid receptor alpha (RAR alpha) and the PML or PLZF nuclear protein are the genetic markers of acute promyelocytic leukemias (APLs). APLs with the PML-RAR alpha or the PLZF-RAR alpha fusion protein are phenotypically indistinguishable except that they differ in their sensitivity to retinoic acid (RA)-induced differentiation: PML-RAR alpha blasts are sensitive to RA and patients enter disease remission after RA treatment, while patients with PLZF-RAR alpha do not. We here report that (i) like PML-RAR alpha expression, PLZF-RAR alpha expression blocks terminal differentiation of hematopoietic precursor cell lines (U937 and HL-60) in response to different stimuli (vitamin D3, transforming growth factor beta1, and dimethyl sulfoxide); (ii) PML-RAR alpha, but not PLZF-RAR alpha, increases RA sensitivity of hematopoietic precursor cells and restores RA sensitivity of RA-resistant hematopoietic cells; (iii) PML-RAR alpha and PLZF-RAR alpha have similar RA binding affinities; and (iv) PML-RAR alpha enhances the RA response of RA target genes (those for RAR beta, RAR gamma, and transglutaminase type II [TGase]) in vivo, while PLZF-RAR alpha expression has either no effect (RAR beta) or an inhibitory activity (RAR gamma and type II TGase). These data demonstrate that PML-RAR alpha and PLZF-RAR alpha have similar (inhibitory) effects on RA-independent differentiation and opposite (stimulatory or inhibitory) effects on RA-dependent differentiation and that they behave in vivo as RA-dependent enhancers or inhibitors of RA-responsive genes, respectively. Their different activities on the RA signalling pathway might underlie the different responses of PML-RAR alpha and PLZF-RAR alpha APLs to RA treatment. The PLZF-RAR alpha fusion protein contains an approximately 120-amino-acid N-terminal motif (called the POZ domain), which is also found in a variety of zinc finger proteins and a group of poxvirus proteins and which mediates protein

  4. 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

  5. The Aldo-Keto Reductase AKR1B10 Is Up-Regulated in Keloid Epidermis, Implicating Retinoic Acid Pathway Dysregulation in the Pathogenesis of Keloid Disease.

    PubMed

    Jumper, Natalie; Hodgkinson, Tom; Arscott, Guyan; Har-Shai, Yaron; Paus, Ralf; Bayat, Ardeshir

    2016-07-01

    Keloid disease is a recurrent fibroproliferative cutaneous tumor of unknown pathogenesis for which clinical management remains unsatisfactory. To obtain new insights into hitherto underappreciated aspects of keloid pathobiology, we took a laser capture microdissection-based, whole-genome microarray analysis approach to identify distinct keloid disease-associated gene expression patterns within defined keloid regions. Identification of the aldo-keto reductase enzyme AKR1B10 as highly up-regulated in keloid epidermis suggested that an imbalance of retinoic acid metabolism is likely associated with keloid disease. Here, we show that AKR1B10 transfection into normal human keratinocytes reproduced the abnormal retinoic acid pathway expression pattern we had identified in keloid epidermis. Cotransfection of AKR1B10 with a luciferase reporter plasmid showed reduced retinoic acid response element activity, supporting the hypothesis of retinoic acid synthesis deficiency in keloid epidermis. Paracrine signals released by AKR1B10-overexpressing keratinocytes into conditioned medium resulted in up-regulation of transforming growth factor-β1, transforming growth factor-β2, and collagens I and III in both keloid and normal skin fibroblasts, mimicking the typical profibrotic keloid profile. Our study results suggest that insufficient retinoic acid synthesis by keloid epidermal keratinocytes may contribute to the pathogenesis of keloid disease. We refocus attention on the role of injured epithelium in keloid disease and identify AKR1B10 as a potential new target in future management of keloid disease. PMID:27025872

  6. Retinoic acid signalling centres in the avian embryo identified by sites of expression of synthesising and catabolising enzymes.

    PubMed

    Blentic, Aida; Gale, Emily; Maden, Malcolm

    2003-05-01

    Retinoic acid is an important signalling molecule in the developing embryo, but its precise distribution throughout development is very difficult to determine by available techniques. Examining the distribution of the enzymes by which it is synthesised by using in situ hybridisation is an alternative strategy. Here, we describe the distribution of three retinoic acid synthesising enzymes and one retinoic acid catabolic enzyme during the early stages of chick embryogenesis with the intention of identifying localized retinoic acid signalling regions. The enzymes involved are Raldh1, Raldh2, Raldh3, and Cyp26A1. Although some of these distributions have been described before, here we assemble them all in one species and several novel sites of enzyme expression are identified, including Hensen's node, the cardiac endoderm, the presumptive pancreatic endoderm, and the dorsal lens. This study emphasizes the dynamic pattern of expression of the enzymes that control the availability of retinoic acid as well as the role that retinoic acid plays in the development of many regions of the embryo throughout embryogenesis. This strategy provides a basis for understanding the phenotypes of retinoic acid teratology and retinoic acid-deficiency syndromes.

  7. Lysyl oxidase-like 4 involvement in retinoic acid epithelial wound healing.

    PubMed

    Comptour, Aurélie; Rouzaire, Marion; Belville, Corinne; Bonnin, Nicolas; Daniel, Estelle; Chiambaretta, Frédéric; Blanchon, Loïc; Sapin, Vincent

    2016-01-01

    Vitamin A and its active forms (retinoic acids/RAs) are known to have pro-healing properties, but their mechanisms of action are still poorly understood. This work aimed to identify the cellular and molecular processes by which atRA (all-trans RA) improves wound healing, using an in vivo model of mouse corneal alkali burns and an in vitro cellular human corneal epithelial injury model. Regulation by atRA has been studied on most of the cellular events that occur in wound healing. We investigated the direct influence of atRA on a specific target gene known to be involved in the extracellular matrix (ECM) dynamics, one of the pathways contributing to epithelial repair. Our results demonstrate that atRA promotes corneal epithelial wound healing by acting preferentially on migration. The induction of lysyl oxidase-like 4 (LOXL4) expression by atRA in the corneal epithelium environment was established as essential in the mechanism of atRA-dependent wound healing. Our study describes for the first time a direct link between a retinoic-induced gene and protein, LOXL4, and its general clinical pro-healing properties in ECM dynamics. PMID:27597564

  8. Lysyl oxidase-like 4 involvement in retinoic acid epithelial wound healing

    PubMed Central

    Comptour, Aurélie; Rouzaire, Marion; Belville, Corinne; Bonnin, Nicolas; Daniel, Estelle; Chiambaretta, Frédéric; Blanchon, Loïc; Sapin, Vincent

    2016-01-01

    Vitamin A and its active forms (retinoic acids/RAs) are known to have pro-healing properties, but their mechanisms of action are still poorly understood. This work aimed to identify the cellular and molecular processes by which atRA (all-trans RA) improves wound healing, using an in vivo model of mouse corneal alkali burns and an in vitro cellular human corneal epithelial injury model. Regulation by atRA has been studied on most of the cellular events that occur in wound healing. We investigated the direct influence of atRA on a specific target gene known to be involved in the extracellular matrix (ECM) dynamics, one of the pathways contributing to epithelial repair. Our results demonstrate that atRA promotes corneal epithelial wound healing by acting preferentially on migration. The induction of lysyl oxidase-like 4 (LOXL4) expression by atRA in the corneal epithelium environment was established as essential in the mechanism of atRA-dependent wound healing. Our study describes for the first time a direct link between a retinoic-induced gene and protein, LOXL4, and its general clinical pro-healing properties in ECM dynamics. PMID:27597564

  9. Contamination with retinoic acid receptor agonists in two rivers in the Kinki region of Japan.

    PubMed

    Inoue, Daisuke; Nakama, Koki; Sawada, Kazuko; Watanabe, Taro; Takagi, Mai; Sei, Kazunari; Yang, Min; Hirotsuji, Junji; Hu, Jianying; Nishikawa, Jun-ichi; Nakanishi, Tsuyoshi; Ike, Michihiko

    2010-04-01

    This study was conducted to investigate the agonistic activity against human retinoic acid receptor (RAR) alpha in the Lake Biwa-Yodo River and the Ina River in the Kinki region of Japan. To accomplish this, a yeast two-hybrid assay was used to elucidate the spatial and temporal variations and potential sources of RARalpha agonist contamination in the river basins. RARalpha agonistic activity was commonly detected in the surface water samples collected along two rivers at different periods, with maximum all-trans retinoic acid (atRA) equivalents of 47.6 ng-atRA/L and 23.5 ng-atRA/L being observed in Lake Biwa-Yodo River and Ina River, respectively. The results indicated that RARalpha agonists are always present and widespread in the rivers. Comparative investigation of RARalpha and estrogen receptor alpha agonistic activities at 20 stations along each river revealed that the spatial variation pattern of RARalpha agonist contamination was entirely different from that of the estrogenic compound contamination. This suggests that the effluent from municipal wastewater treatment plants, a primary source of estrogenic compounds, seemed not to be the cause of RARalpha agonist contamination in the rivers. Fractionation using high performance liquid chromatography (HPLC) directed by the bioassay found two bioactive fractions from river water samples, suggesting the presence of at least two RARalpha agonists in the rivers. Although a trial conducted to identify RARalpha agonists in the major bioactive fraction was not completed as part of this study, comparison of retention times in HPLC analysis and quantification with liquid chromatography-mass spectrometry analysis revealed that the major causative contaminants responsible for the RARalpha agonistic activity were not RAs (natural RAR ligands) and 4-oxo-RAs, while 4-oxo-RAs were identified as the major RAR agonists in sewage in Beijing, China. These findings suggest that there are unknown RARalpha agonists with high

  10. Saturated fatty acids regulate retinoic acid signalling and suppress tumorigenesis by targeting fatty acid-binding protein 5.

    PubMed

    Levi, Liraz; Wang, Zeneng; Doud, Mary Kathryn; Hazen, Stanley L; Noy, Noa

    2015-01-01

    Long chain fatty acids (LCFA) serve as energy sources, components of cell membranes and precursors for signalling molecules. Here we show that these biological compounds also regulate gene expression and that they do so by controlling the transcriptional activities of the retinoic acid (RA)-activated nuclear receptors RAR and PPARβ/δ. The data indicate that these activities of LCFA are mediated by FABP5, which delivers ligands from the cytosol to nuclear PPARβ/δ. Both saturated and unsaturated LCFA (SLCFA, ULCFA) bind to FABP5, thereby displacing RA and diverting it to RAR. However, while SLCFA inhibit, ULCFA activate the FABP5/PPARβ/δ pathway. We show further that, by concomitantly promoting the activation of RAR and inhibiting the activation of PPARβ/δ, SLCFA suppress the oncogenic properties of FABP5-expressing carcinoma cells in cultured cells and in vivo. The observations suggest that compounds that inhibit FABP5 may constitute a new class of drugs for therapy of certain types of cancer. PMID:26592976

  11. A Novel Method for the Preparation of Retinoic Acid-Loaded Nanoparticles

    PubMed Central

    Errico, Cesare; Gazzarri, Matteo; Chiellini, Federica

    2009-01-01

    The goal of present work was to investigate the use of bioerodible polymeric nanoparticles as carriers of retinoic acid (RA), which is known to induce differentiation of several cell lines into neurons. A novel method, named “Colloidal-Coating”, has been developed for the preparation of nanoparticles based on a copolymer of maleic anhydride and butyl vinyl ether (VAM41) loaded with RA. Nanoparticles with an average diameter size of 70 nm and good morphology were prepared. The activity of the encapsulated RA was evaluated on SK-N-SH human neuroblastoma cells, which are known to undergo inhibition of proliferation and neuronal differentiation upon treatment with RA. The activity of RA was not affected by the encapsulation and purification processes. PMID:19564952

  12. The histone demethylase PHF8 governs retinoic acid response in acute promyelocytic leukemia.

    PubMed

    Arteaga, Maria Francisca; Mikesch, Jan-Henrik; Qiu, Jihui; Christensen, Jesper; Helin, Kristian; Kogan, Scott C; Dong, Shuo; So, Chi Wai Eric

    2013-03-18

    While all-trans retinoic acid (ATRA) treatment in acute promyelocytic leukemia (APL) has been the paradigm of targeted therapy for oncogenic transcription factors, the underlying mechanisms remain largely unknown, and a significant number of patients still relapse and become ATRA resistant. We identified the histone demethylase PHF8 as a coactivator that is specifically recruited by RARα fusions to activate expression of their downstream targets upon ATRA treatment. Forced expression of PHF8 resensitizes ATRA-resistant APL cells, whereas its downregulation confers resistance. ATRA sensitivity depends on the enzymatic activity and phosphorylation status of PHF8, which can be pharmacologically manipulated to resurrect ATRA sensitivity to resistant cells. These findings provide important molecular insights into ATRA response and a promising avenue for overcoming ATRA resistance.

  13. All-Trans Retinoic Acid Induces TGF-β2 in Intestinal Epithelial Cells via RhoA- and p38α MAPK-Mediated Activation of the Transcription Factor ATF2

    PubMed Central

    Namachivayam, Kopperuncholan; MohanKumar, Krishnan; Arbach, Dima; Jagadeeswaran, Ramasamy; Jain, Sunil K.; Natarajan, Viswanathan; Mehta, Dolly; Jankov, Robert P.; Maheshwari, Akhil

    2015-01-01

    Objective We have shown previously that preterm infants are at risk of necrotizing enterocolitis (NEC), an inflammatory bowel necrosis typically seen in infants born prior to 32 weeks’ gestation, because of the developmental deficiency of transforming growth factor (TGF)-β2 in the intestine. The present study was designed to investigate all-trans retinoic acid (atRA) as an inducer of TGF-β2 in intestinal epithelial cells (IECs) and to elucidate the involved signaling mechanisms. Methods AtRA effects on intestinal epithelium were investigated using IEC6 cells. TGF-β2 expression was measured using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) and Western blots. Signaling pathways were investigated using Western blots, transiently-transfected/transduced cells, kinase arrays, chromatin immunoprecipitation, and selective small molecule inhibitors. Results AtRA-treatment of IEC6 cells selectively increased TGF-β2 mRNA and protein expression in a time- and dose-dependent fashion, and increased the activity of the TGF-β2 promoter. AtRA effects were mediated via RhoA GTPase, Rho-associated, coiled-coil-containing protein kinase 1 (ROCK1), p38α MAPK, and activating transcription factor (ATF)-2. AtRA increased phospho-ATF2 binding to the TGF-β2 promoter and increased histone H2B acetylation in the TGF-β2 nucleosome, which is typically associated with transcriptional activation. Conclusions AtRA induces TGF-β2 expression in IECs via RhoA- and p38α MAPK-mediated activation of the transcription factor ATF2. Further studies are needed to investigate the role of atRA as a protective/therapeutic agent in gut mucosal inflammation. PMID:26225425

  14. An enzymatic mechanism for generating the precursor of endogenous 13-cis retinoic acid in the brain.

    PubMed

    Takahashi, Yusuke; Moiseyev, Gennadiy; Chen, Ying; Farjo, Krysten; Nikolaeva, Olga; Ma, Jian-Xing

    2011-04-01

    13-cis Retinoic acid (13cRA), a stereoisomeric form of retinoic acid, is naturally generated in the body and is also used clinically to treat acute promyelocytic leukemia, some skin diseases and cancer. Furthermore, it has been suggested that 13cRA modulates brain neurochemical systems because increased 13cRA levels are correlated with depression and increased suicidal tendencies. However, the mechanism for the generation of endogenous 13cRA is not well understood. The present study identified and characterized a novel enzyme in zebrafish brain, 13-cis isomerohydrolase (13cIMH) (EC 5.2.1.7), which exclusively generated 13-cis retinol and can be oxidized to 13cRA. 13cIMH shares 74% amino acid sequence identity with human retinal pigment epithelium specific 65 kDa protein (RPE65), an 11-cis isomerohydrolase in the visual cycle, and retains the key residues essential for the isomerohydrolase activity of RPE65. Similar to RPE65, 13cIMH is a membrane-associated protein, requires all-trans retinyl ester as its intrinsic substrate, and its enzymatic activity is dependent on iron. The purified 13cIMH converted all-trans retinyl ester exclusively to 13-cis retinol with K(m)  = 2.6 μm and k(cat) = 4.4 × 10(-4) ·s(-1) . RT-PCR, western blot analysis and immunohistochemistry detected 13cIMH expression in the brain. These results suggest that 13cIMH may play a key role in the generation of 13cRA, as well as in the modulation of neuronal functions in the brain.

  15. Comparative effects of retinoic acid or glycolic acid vehiculated in different topical formulations.

    PubMed

    Maia Campos, Patrícia Maria Berardo Gonçalves; Gaspar, Lorena Rigo; Gonçalves, Gisele Mara Silva; Pereira, Lúcia Helena Terenciane Rodrigues; Semprini, Marisa; Lopes, Ruberval Armando

    2015-01-01

    Retinoids and hydroxy acids have been widely used due to their effects in the regulation of growth and in the differentiation of epithelial cells. However, besides their similar indication, they have different mechanisms of action and thus they may have different effects on the skin; in addition, since the topical formulation efficiency depends on vehicle characteristics, the ingredients of the formulation could alter their effects. Thus the objective of this study was to compare the effects of retinoic acid (RA) and glycolic acid (GA) treatment on the hairless mouse epidermis thickness and horny layer renewal when added in gel, gel cream, or cream formulations. For this, gel, gel cream, and cream formulations (with or without 6% GA or 0.05% RA) were applied in the dorsum of hairless mice, once a day for seven days. After that, the skin was analyzed by histopathologic, morphometric, and stereologic techniques. It was observed that the effects of RA occurred independently from the vehicle, while GA had better results when added in the gel cream and cream. Retinoic acid was more effective when compared to glycolic acid, mainly in the cell renewal and the exfoliation process because it decreased the horny layer thickness.

  16. 9-Cis Retinoic Acid Promotes Lymphangiogenesis and Enhances Lymphatic Vessel Regeneration: Therapeutic Implications of 9-Cis Retinoic Acid for Secondary Lymphedema

    PubMed Central

    Choi, Inho; Lee, Sunju; Chung, Hee Kyoung; Lee, Yong Suk; Kim, Kyu Eui; Choi, Dongwon; Park, Eun Kyung; Yang, Dongyun; Ecoiffier, Tatiana; Monahan, John; Chen, Wen; Aguilar, Berenice; Lee, Ha Neul; Yoo, Jaehyuk; Koh, Chester J.; Chen, Lu; Wong, Alex K.; Hong, Young-Kwon

    2012-01-01

    Background The lymphatic system plays a key role in tissue fluid homeostasis and lymphatic dysfunction due to genetic defects or lymphatic vessel obstruction can cause lymphedema, disfiguring tissue swellings often associated with fibrosis and recurrent infections without available cures to date. In this study, retinoic acids (RAs) were determined to be a potent therapeutic agent that is immediately applicable to reduce secondary lymphedema. Methods and Results We report that RAs promote proliferation, migration and tube formation of cultured lymphatic endothelial cells (LECs) by activating FGF-receptor signaling. Moreover, RAs control the expression of cell-cycle checkpoint regulators such as p27Kip1, p57Kip2 and the aurora kinases through both an Akt-mediated non-genomic action and a transcription-dependent genomic action that is mediated by Prox1, a master regulator of lymphatic development. Moreover, 9-cisRA was found to activate in vivo lymphangiogenesis in animals based on mouse trachea, matrigel plug and cornea pocket assays. Finally, we demonstrate that 9-cisRA can provide a strong therapeutic efficacy in ameliorating the experimental mouse tail lymphedema by enhancing lymphatic vessel regeneration. Conclusions These in vitro and animal studies demonstrate that 9-cisRA potently activates lymphangiogenesis and promotes lymphatic regeneration in an experimental lymphedema model, presenting it as a promising novel therapeutic agent to treat human lymphedema patients. PMID:22275501

  17. Retinoic acid receptor agonists regulate expression of ATP-binding cassette transporter G1 in macrophages.

    PubMed

    Ayaori, Makoto; Yakushiji, Emi; Ogura, Masatsune; Nakaya, Kazuhiro; Hisada, Tetsuya; Uto-Kondo, Harumi; Takiguchi, Shunichi; Terao, Yoshio; Sasaki, Makoto; Komatsu, Tomohiro; Iizuka, Maki; Yogo, Makiko; Uehara, Yoshinari; Kagechika, Hiroyuki; Nakanishi, Tsuyoshi; Ikewaki, Katsunori

    2012-04-01

    ABC transporter G1 (ABCG1) plays a pivotal role in HDL-mediated cholesterol efflux and atherogenesis. We investigated whether, and how, retinoic acid receptors (RARs) regulate ABCG1 expression in macrophages. All-trans retinoic acid (ATRA), an RAR ligand, increased ABCG1 protein levels and apoA-I/HDL-mediated cholesterol efflux from the macrophages. Both ATRA and other RAR agonists, TTNPB and Am580, increased major transcripts driven by promoter B upstream of exon 5, though minor transcripts driven by promoter A upstream of exon 1 were only increased by ATRA. The stimulatory effects of ATRA on ABCG1 expression were completely abolished in the presence of RAR/RXR antagonists but were only partially canceled in the presence of an LXR antagonist. Adenovirus with overexpressed oxysterol sulfotransferase abolished the LXR pathway, as previously reported, and ATRA-responsiveness in ABCA1/ABCG1 expressions were respectively attenuated by 38 and 22% compared to the control virus. Promoter assays revealed that ABCG1 levels were regulated more by promoter B than promoter A, and ATRA activated promoter B in a liver X receptor-responsive element (LXRE)-dependent manner. Further, LXRE-B in intron 7, but not LXRE-A in intron 5, enhanced ATRA responsiveness under overexpression of all RAR isoforms-RARα/β/γ. In contrast, the activation of promoter B by TTNPB depended on LXRE-B and RARα, but not on RARβ/γ. Finally, chromatin immunoprecipitation and gel-shift assays revealed a specific and direct repeat 4-dependent binding of RARα to LXRE-B. In conclusion, RAR ligands increase ABCA1/G1 expression and apoA-I/HDL-mediated cholesterol efflux from macrophages, and modulate ABCG1 promoter activity via LXRE-dependent mechanisms.

  18. Retinoic acid regulates Kit translation during spermatogonial differentiation in the mouse

    PubMed Central

    Busada, Jonathan T.; Chappell, Vesna A.; Niedenberger, Bryan A.; Kaye, Evelyn P.; Keiper, Brett D.; Hogarth, Cathryn A.; Geyer, Christopher B.

    2014-01-01

    In the testis, a subset of spermatogonia retains stem cell potential, while others differentiate to eventually become spermatozoa. This delicate balance must be maintained, as defects can result in testicular cancer or infertility. Currently, little is known about the gene products and signaling pathways directing these critical cell fate decisions. Retinoic acid (RA) is a requisite driver of spermatogonial differentiation and entry into meiosis, yet the mechanisms activated downstream are undefined. Here, we determined a requirement for RA in the expression of KIT, a receptor tyrosine kinase essential for spermatogonial differentiation. We found that RA signaling utilized the PI3K/AKT/mTOR signaling pathway to induce the efficient translation of mRNAs for Kit, which are present but not translated in undifferentiated spermatogonia. Our findings provide an important molecular link between a morphogen (RA) and the expression of KIT protein, which together direct the differentiation of spermatogonia throughout the male reproductive lifespan. PMID:25446031

  19. MicroRNA and DNA methylation alterations mediating retinoic acid induced neuroblastoma cell differentiation.

    PubMed

    Stallings, Raymond L; Foley, Niamh H; Bray, Isabella M; Das, Sudipto; Buckley, Patrick G

    2011-10-01

    Many neuroblastoma cell lines can be induced to differentiate into a mature neuronal cell type with retinoic acid and other compounds, providing an important model system for elucidating signalling pathways involved in this highly complex process. Recently, it has become apparent that miRNAs, which act as regulators of gene expression at a post-transcriptional level, are differentially expressed in differentiating cells and play important roles governing many aspects of this process. This includes the down-regulation of DNA methyltransferases that cause the de-methylation and transcriptional activation of numerous protein coding gene sequences. The purpose of this article is to review involvement of miRNAs and DNA methylation alterations in the process of neuroblastoma cell differentiation. A thorough understanding of miRNA and genetic pathways regulating neuroblastoma cell differentiation potentially could lead to targeted therapies for this disease.

  20. Identification of a retinoic acid responsive aldoketoreductase expressed in HL60 leukaemic cells.

    PubMed

    Mills, K I; Gilkes, A F; Sweeney, M; Choudhry, M A; Woodgate, L J; Bunce, C M; Brown, G; Burnett, A K

    1998-11-27

    Neutrophil and monocyte differentiation can be induced in HL60 leukaemia cells by all-trans-retinoic acid (ATRA) and 1alpha,25-dihydroxyvitamin D3 (D3), respectively, whose differentiating effects can be enhanced by exposure to 'anti-inflammatory agents' and steroids. We have provided evidence that this potentiation is via inhibition of the activity of an enzyme of the aldoketoreductase (AKR) family, but had failed to identify expression of known AKRs in HL60 cells. In this study, we have identified a previously unclassified aldoketoreductase family member (termed HAKR e) that is expressed in HL60 cells. HAKR e is dramatically and transiently up-regulated in HL60 cells within 24 h of exposure to ATRA, further supporting the proposition that a member(s) of this family of enzymes play(s) a role in controlling cell growth and/or differentiation.

  1. Mechanisms of retinoic acid signalling and its roles in organ and limb development

    PubMed Central

    Cunningham, Thomas J.; Duester, Gregg

    2015-01-01

    Retinoic acid (RA) signalling has a central role during vertebrate development. RA synthesized in specific locations regulates transcription by interacting with nuclear RA receptors (RARs) bound to RA response elements (RAREs) near target genes. RA was first implicated in signalling on the basis of its teratogenic effects on limb development. Genetic studies later revealed that endogenous RA promotes forelimb initiation by repressing fibroblast growth factor 8 (Fgf8). Insights into RA function in the limb serve as a paradigm for understanding how RA regulates other developmental processes. In vivo studies have identified RAREs that control repression of Fgf8 during body axis extension or activation of homeobox (Hox) genes and other key regulators during neuronal differentiation and organogenesis. PMID:25560970

  2. Control of retinoic acid receptor heterodimerization by ligand-induced structural transitions. A novel mechanism of action for retinoid antagonists.

    PubMed

    Depoix, C; Delmotte, M H; Formstecher, P; Lefebvre, P

    2001-03-23

    Heterodimerization of retinoic acid receptors (RARs) with 9-cis-retinoic receptors (RXRs) is a prerequisite for binding of RXR.RAR dimers to DNA and for retinoic acid-induced gene regulation. Whether retinoids control RXR/RAR solution interaction remains a debated question, and we have used in vitro and in vivo protein interaction assays to investigate the role of ligand in modulating RXR/RAR interaction in the absence of DNA. Two-hybrid assay in mammalian cells demonstrated that only RAR agonists were able to increase significantly RAR interaction with RXR, whereas RAR antagonists inhibited RXR binding to RAR. Quantitative glutathione S-transferase pull-down assays established that there was a strict correlation between agonist binding affinity for the RAR monomer and the affinity of RXR for liganded RAR, but RAR antagonists were inactive in inducing RXR recruitment to RAR in vitro. Alteration of coactivator- or corepressor-binding interfaces of RXR or RAR did not alter ligand-enhanced dimerization. In contrast, preventing the formation of a stable holoreceptor structure upon agonist binding strongly altered RXR.RAR dimerization. Finally, we observed that RAR interaction with RXR silenced RXR ligand-dependent activation function. We propose that ligand-controlled dimerization of RAR with RXR is an important step in the RXR.RAR activation process. This interaction is dependent upon adequate remodeling of the AF-2 structure and amenable to pharmacological inhibition by structurally modified retinoids.

  3. Expression of a retinoic acid signature in circulating CD34 cells from coronary artery disease patients

    PubMed Central

    2010-01-01

    Background Circulating CD34+ progenitor cells have the potential to differentiate into a variety of cells, including endothelial cells. Knowledge is still scarce about the transcriptional programs used by CD34+ cells from peripheral blood, and how these are affected in coronary artery disease (CAD) patients. Results We performed a whole genome transcriptome analysis of CD34+ cells, CD4+ T cells, CD14+ monocytes, and macrophages from 12 patients with CAD and 11 matched controls. CD34+ cells, compared to other mononuclear cells from the same individuals, showed high levels of KRAB box transcription factors, known to be involved in gene silencing. This correlated with high expression levels in CD34+ cells for the progenitor markers HOXA5 and HOXA9, which are known to control expression of KRAB factor genes. The comparison of expression profiles of CD34+ cells from CAD patients and controls revealed a less naïve phenotype in patients' CD34+ cells, with increased expression of genes from the Mitogen Activated Kinase network and a lowered expression of a panel of histone genes, reaching levels comparable to that in more differentiated circulating cells. Furthermore, we observed a reduced expression of several genes involved in CXCR4-signaling and migration to SDF1/CXCL12. Conclusions The altered gene expression profile of CD34+ cells in CAD patients was related to activation/differentiation by a retinoic acid-induced differentiation program. These results suggest that circulating CD34+ cells in CAD patients are programmed by retinoic acid, leading to a reduced capacity to migrate to ischemic tissues. PMID:20565948

  4. 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

  5. UPTAKE AND METABOLISM OF ALL-TRANS RETINOIC ACID BY THREE NATIVE NORTH AMERICAN RANIDS

    EPA Science Inventory

    Retinoids, which are Vvitamin 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 the model retinoid, all-trans retinoic acid (all-trans RA), by th...

  6. 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

  7. Regulation of laminin and entactin mRNA levels by retinoic acid and dibutyryl cyclic AMP

    SciTech Connect

    Durkin, M.E.; Phillips, S.L.; Carlin, B.E.; Merlie, J.P.; Chung, A.E.

    1986-05-01

    Retinoic acid and dibutyryl cAMP induced F9 embryonal carcinoma cells to differentiate to parietal endoderm; the morphological changes were accompanied by the increased synthesis of the basement membrane glycoproteins laminin and entactin. cDNA clones have been isolated for the A (400 kD), B1 (220 kD), and B2 (205 kD) chains of laminin. Northern blot analysis indicated that the A, B1, and B2 chains were encoded by RNA species of 9.8, 6.0, and 8.0 kb, respectively. The kinetics of induction of the laminin mRNAs were studied by dot-blotting dilutions of RNA extracted from F9 cells cultured in retinoic acid and dibutyryl cAMP for increasing amounts of time and hybridizing to /sup 32/P-labeled recombinant plasmids. Very low levels of the A and B chain RNAs were found in uninduced cells, and a large increase occurred between 48 and 72 hr of growth in retinoic acid and dibutyryl cAMP. A cDNA clone was also obtained for entactin, a 150 kD glycoprotein that forms a complex with laminin. Retinoic acid and dibutyryl cAMP treatment also increased the amount of entactin RNA in F9 cells. These results suggested that a common mechanism may exist for the coordinate regulation of the 4 basement membrane protein genes during differentiation.

  8. 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.

  9. FOXP2 drives neuronal differentiation by interacting with retinoic acid signaling pathways

    PubMed Central

    Devanna, Paolo; Middelbeek, Jeroen; Vernes, Sonja C.

    2014-01-01

    FOXP2 was the first gene shown to cause a Mendelian form of speech and language disorder. Although developmentally expressed in many organs, loss of a single copy of FOXP2 leads to a phenotype that is largely restricted to orofacial impairment during articulation and linguistic processing deficits. Why perturbed FOXP2 function affects specific aspects of the developing brain remains elusive. We investigated the role of FOXP2 in neuronal differentiation and found that FOXP2 drives molecular changes consistent with neuronal differentiation in a human model system. We identified a network of FOXP2 regulated genes related to retinoic acid signaling and neuronal differentiation. FOXP2 also produced phenotypic changes associated with neuronal differentiation including increased neurite outgrowth and reduced migration. Crucially, cells expressing FOXP2 displayed increased sensitivity to retinoic acid exposure. This suggests a mechanism by which FOXP2 may be able to increase the cellular differentiation response to environmental retinoic acid cues for specific subsets of neurons in the brain. These data demonstrate that FOXP2 promotes neuronal differentiation by interacting with the retinoic acid signaling pathway and regulates key processes required for normal circuit formation such as neuronal migration and neurite outgrowth. In this way, FOXP2, which is found only in specific subpopulations of neurons in the brain, may drive precise neuronal differentiation patterns and/or control localization and connectivity of these FOXP2 positive cells. PMID:25309332

  10. FOXP2 drives neuronal differentiation by interacting with retinoic acid signaling pathways.

    PubMed

    Devanna, Paolo; Middelbeek, Jeroen; Vernes, Sonja C

    2014-01-01

    FOXP2 was the first gene shown to cause a Mendelian form of speech and language disorder. Although developmentally expressed in many organs, loss of a single copy of FOXP2 leads to a phenotype that is largely restricted to orofacial impairment during articulation and linguistic processing deficits. Why perturbed FOXP2 function affects specific aspects of the developing brain remains elusive. We investigated the role of FOXP2 in neuronal differentiation and found that FOXP2 drives molecular changes consistent with neuronal differentiation in a human model system. We identified a network of FOXP2 regulated genes related to retinoic acid signaling and neuronal differentiation. FOXP2 also produced phenotypic changes associated with neuronal differentiation including increased neurite outgrowth and reduced migration. Crucially, cells expressing FOXP2 displayed increased sensitivity to retinoic acid exposure. This suggests a mechanism by which FOXP2 may be able to increase the cellular differentiation response to environmental retinoic acid cues for specific subsets of neurons in the brain. These data demonstrate that FOXP2 promotes neuronal differentiation by interacting with the retinoic acid signaling pathway and regulates key processes required for normal circuit formation such as neuronal migration and neurite outgrowth. In this way, FOXP2, which is found only in specific subpopulations of neurons in the brain, may drive precise neuronal differentiation patterns and/or control localization and connectivity of these FOXP2 positive cells.

  11. 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

  12. Novel retinoic acid receptor alpha agonists for treatment of kidney disease.

    PubMed

    Zhong, Yifei; Wu, Yingwei; 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.

  13. Synthesis and characterization of a new retinoic acid ECPIRM as potential chemotherapeutic agent for human cutaneous squamous carcinoma.

    PubMed

    Zhang, Mengli; Tao, Yue; Ma, Pengcheng; Wang, Dechuan; He, Chundi; Cao, Yuping; Wei, Jun; Li, Lingjun; Tao, Lei

    2015-01-01

    Cutaneous squamous cell carcinoma (CSCC) is one of the most common cancers worldwide, requiring effective therapeutic interventions. Retinoids are important chemopreventive and therapeutic agents for a variety of human cancers including CSCC. In this study we synthesized a novel retinoic derivative N-(4-ethoxycarbonylphenyl) isoretinamide (ECPIRM) and evaluated its biological activities and possible mechanisms in human cutaneous squamous cell lines. ECPIRM had better inhibitory effect on the proliferation of squamous carcinoma cells SCL-1 and colo-16, compared with All-trans retinoic acid and 13-cis retinoic acid. ECPIRM had less toxicity to normal keratinocyte cell line HaCaT. Mechanistically, ECPIRM induced G1 cell cycle arrest in SCL-1 cells, via the downregulation of CDK2, CDK4, cycling D1 and cyclin E expression and upregulation of p21. In addition, these effects were at least partially due to the inhibition of JNK/ ERK-AP-1 signaling pathway by ECPIRM. Importantly, these effects of ECPIRM are independent of the classical retinoid receptor pathway, suggesting that the novel compound will have less side-effects in chemotherapy. These findings demonstrate that ECPIRM is a potential inhibitor of MPAK-AP-1 pathway, and is a potential therapeutic agent against CSCC.

  14. Synthesis and characterization of a new retinoic acid ECPIRM as potential chemotherapeutic agent for human cutaneous squamous carcinoma.

    PubMed

    Zhang, Mengli; Tao, Yue; Ma, Pengcheng; Wang, Dechuan; He, Chundi; Cao, Yuping; Wei, Jun; Li, Lingjun; Tao, Lei

    2015-01-01

    Cutaneous squamous cell carcinoma (CSCC) is one of the most common cancers worldwide, requiring effective therapeutic interventions. Retinoids are important chemopreventive and therapeutic agents for a variety of human cancers including CSCC. In this study we synthesized a novel retinoic derivative N-(4-ethoxycarbonylphenyl) isoretinamide (ECPIRM) and evaluated its biological activities and possible mechanisms in human cutaneous squamous cell lines. ECPIRM had better inhibitory effect on the proliferation of squamous carcinoma cells SCL-1 and colo-16, compared with All-trans retinoic acid and 13-cis retinoic acid. ECPIRM had less toxicity to normal keratinocyte cell line HaCaT. Mechanistically, ECPIRM induced G1 cell cycle arrest in SCL-1 cells, via the downregulation of CDK2, CDK4, cycling D1 and cyclin E expression and upregulation of p21. In addition, these effects were at least partially due to the inhibition of JNK/ ERK-AP-1 signaling pathway by ECPIRM. Importantly, these effects of ECPIRM are independent of the classical retinoid receptor pathway, suggesting that the novel compound will have less side-effects in chemotherapy. These findings demonstrate that ECPIRM is a potential inhibitor of MPAK-AP-1 pathway, and is a potential therapeutic agent against CSCC. PMID:25991427

  15. Differentiation-inducing and anti-proliferative activities of isoliquiritigenin and all-trans-retinoic acid on B16F0 melanoma cells: Mechanisms profiling by RNA-seq.

    PubMed

    Chen, Xiaoyu; Yang, Ming; Hao, Wenjin; Han, Jichun; Ma, Jun; Wang, Caixia; Sun, Shiguo; Zheng, Qiusheng

    2016-10-30

    Melanoma is a cancer that arises from melanocytes, specialized pigmented cells that are found predominantly in the skin. The incidence of malignant melanoma has significantly increased over the last decade. With the development of therapy, the survival rate of some kind of cancer has been improved greatly. But the treatment of melanoma remains unsatisfactory. Much of melanoma's resistance to traditional chemotherapy is believed to arise intrinsically, by virtue of potent growth and cell survival-promoting genetic alteration. Therefore, significant attention has recently been focused on differentiation therapy, as well as differentiation inducer compounds. In previous study, we found isoliquiritigenin (ISL), a natural product extracted from licorice, could induce B16F0 melanoma cell differentiation. Here we investigated the transcriptional response of melanoma differentiation process induced by ISL and all-trans-retinoic acid (RA). Results showed that 390 genes involves in 201 biochemical pathways were differentially expressed in ISL treatment and 304 genes in 193 pathways in RA treatment. Differential expressed genes (DGEs, fold-change (FC)≥10) with the function of anti-proliferative and differentiation inducing indicated a loss of grade malignancy characteristic. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated glutathione metabolism, glycolysis/gluconeogenesis and pentose phosphate pathway were the top three relative pathway perturbed by ISL, and mitogen-activated protein kinase (MAPK) signaling pathway was the most important pathway in RA treatment. In the analysis of hierarchical clustering of DEGs, we discovered 72 DEGs involved in the process of drug action. We thought Cited1, Tgm2, Xaf1, Cd59a, Fbxo2, Adh7 may have critical role in the differentiation of melanoma. The evidence displayed herein confirms the critical role of reactive oxygen species (ROS) in melanoma pathobiology and provides evidence for future targets in the

  16. Differentiation-inducing and anti-proliferative activities of isoliquiritigenin and all-trans-retinoic acid on B16F0 melanoma cells: Mechanisms profiling by RNA-seq.

    PubMed

    Chen, Xiaoyu; Yang, Ming; Hao, Wenjin; Han, Jichun; Ma, Jun; Wang, Caixia; Sun, Shiguo; Zheng, Qiusheng

    2016-10-30

    Melanoma is a cancer that arises from melanocytes, specialized pigmented cells that are found predominantly in the skin. The incidence of malignant melanoma has significantly increased over the last decade. With the development of therapy, the survival rate of some kind of cancer has been improved greatly. But the treatment of melanoma remains unsatisfactory. Much of melanoma's resistance to traditional chemotherapy is believed to arise intrinsically, by virtue of potent growth and cell survival-promoting genetic alteration. Therefore, significant attention has recently been focused on differentiation therapy, as well as differentiation inducer compounds. In previous study, we found isoliquiritigenin (ISL), a natural product extracted from licorice, could induce B16F0 melanoma cell differentiation. Here we investigated the transcriptional response of melanoma differentiation process induced by ISL and all-trans-retinoic acid (RA). Results showed that 390 genes involves in 201 biochemical pathways were differentially expressed in ISL treatment and 304 genes in 193 pathways in RA treatment. Differential expressed genes (DGEs, fold-change (FC)≥10) with the function of anti-proliferative and differentiation inducing indicated a loss of grade malignancy characteristic. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated glutathione metabolism, glycolysis/gluconeogenesis and pentose phosphate pathway were the top three relative pathway perturbed by ISL, and mitogen-activated protein kinase (MAPK) signaling pathway was the most important pathway in RA treatment. In the analysis of hierarchical clustering of DEGs, we discovered 72 DEGs involved in the process of drug action. We thought Cited1, Tgm2, Xaf1, Cd59a, Fbxo2, Adh7 may have critical role in the differentiation of melanoma. The evidence displayed herein confirms the critical role of reactive oxygen species (ROS) in melanoma pathobiology and provides evidence for future targets in the

  17. 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.

  18. Regional Differentiation of Retinoic Acid-Induced Human Pluripotent Embryonic Carcinoma Stem Cell Neurons

    PubMed Central

    Coyle, Dennis E.; Li, Jie; Baccei, Mark

    2011-01-01

    The NTERA2 cl D1 (NT2) cell line, derived from human teratocarcinoma, exhibits similar properties as embryonic stem (ES) cells or very early neuroepitheial progenitors. NT2 cells can be induced to become postmitotic central nervous system neurons (NT2N) with retinoic acid. Although neurons derived from pluripotent cells, such as NT2N, have been characterized for their neurotransmitter phenotypes, their potential suitability as a donor source for neural transplantation also depends on their ability to respond to localized environmental cues from a specific region of the CNS. Therefore, our study aimed to characterize the regional transcription factors that define the rostocaudal and dorsoventral identity of NT2N derived from a monolayer differentiation paradigm using quantitative PCR (qPCR). Purified NT2N mainly expressed both GABAergic and glutamatergic phenotypes and were electrically active but did not form functional synapses. The presence of immature astrocytes and possible radial glial cells was noted. The NT2N expressed a regional transcription factor code consistent with forebrain, hindbrain and spinal cord neural progenitors but showed minimal expression of midbrain phenotypes. In the dorsoventral plane NT2N expressed both dorsal and ventral neural progenitors. Of major interest was that even under the influence of retinoic acid, a known caudalization factor, the NT2N population maintained a rostral phenotype subpopulation which expressed cortical regional transcription factors. It is proposed that understanding the regional differentiation bias of neurons derived from pluripotent stem cells will facilitate their successful integration into existing neuronal networks within the CNS. PMID:21283767

  19. Effect of retinoic acid and ethanol on retinoic acid receptor beta and glial fibrillary acidic protein mRNA expression in human astrocytoma cells.

    PubMed

    Grummer, M A; Salih, Z N; Zachman, R D

    2000-11-17

    This work explores the hypothesis that perturbations caused by ethanol on the regulatory role of retinoids in brain development may be a mechanism involved in the neuropathology of fetal alcohol syndrome. The interaction of ethanol and retinoic acid (RA) on RA receptor (RAR) beta and glial fibrillary acidic protein (GFAP) mRNA expression is evaluated. In the U-373 MG astrocytoma, mRNA expression of RAR beta was increased and GFAP was decreased by RA. Ethanol decreased the expression of RAR beta mRNA, but increased that of GFAP. The RA-stimulated increase in RAR beta was not affected by the presence of ethanol. RA prevented the ethanol-induced increase in GFAP mRNA. Cycloheximide abolished only the GFAP response to ethanol. This work shows that an interrelationship between ethanol and RA exists in the astrocyte. PMID:11058790

  20. Inhibition of epithelial cell adhesion by retinoic acid. Relationship to reduced extracellular matrix production and alterations in Ca2+ levels.

    PubMed Central

    Varani, J.; Gibbs, D. F.; Inman, D. R.; Shah, B.; Fligiel, S. E.; Voorhees, J. J.

    1991-01-01

    Human squamous epithelial cells maintained in growth factor-deficient medium were examined for sensitivity to all-trans retinoic acid (retinoic acid). Under conditions of low external Ca2+ (0.15 mmol/l [millimolar]), or high external Ca2+ (1.4 mmol/l), retinoic acid stimulated proliferation. Concomitantly, cell-substrate adhesion was decreased. Enzyme-linked immunosorbent assays were used to assess production of two extracellular matrix components, ie, fibronectin and thrombospondin. In the presence of retinoic acid, production of both was decreased. Because both fibronectin and thrombospondin serve as epithelial cell adhesion factors, the decreased production of these moieties could contribute to reduced adhesion. Using 45Ca2+ to measure total cell-associated Ca2+ and the Ca2(+)-sensitive dye Indo-1 to measure intracellular free Ca2+, it was found that concentrations of retinoic acid that altered cell-substrate adhesion in the squamous epithelial cells had no effect on total, cell-associated Ca2+, but reduced intracellular free Ca2+ by 50% to 60%. Because Ca2+ is a regulator of adhesion, the ability of retinoic acid to modulate Ca2+ levels in the squamous epithelial cells may explain, in part, how retinoic acid influences their adhesiveness. Images Figure 1 PMID:2012176

  1. Retinoic Acid Upregulates Preadipocyte Genes to Block Adipogenesis and Suppress Diet-Induced Obesity

    PubMed Central

    Berry, Daniel C.; DeSantis, David; Soltanian, Hooman; Croniger, Colleen M.; Noy, Noa

    2012-01-01

    Retinoic acid (RA) protects mice from diet-induced obesity. The activity is mediated in part through activation of the nuclear receptors RA receptors (RARs) and peroxisome proliferator–activated receptor β/δ and their associated binding proteins cellular RA binding protein type II (CRABP-II) and fatty acid binding protein type 5 in adipocytes and skeletal muscle, leading to enhanced lipid oxidation and energy dissipation. It was also reported that RA inhibits differentiation of cultured preadipocytes. However, whether the hormone suppresses adipogenesis in vivo and how the activity is propagated remained unknown. In this study, we show that RA inhibits adipocyte differentiation by activating the CRABP-II/RARγ path in preadipose cells, thereby upregulating the expression of the adipogenesis inhibitors Pref-1, Sox9, and Kruppel-like factor 2 (KLF2). In turn, KLF2 induces the expression of CRABP-II and RARγ, further potentiating inhibition of adipocyte differentiation by RA. The data also indicate that RA suppresses adipogenesis in vivo and that the activity significantly contributes to the ability of the hormone to counteract diet-induced obesity. PMID:22396202

  2. Predicting, Monitoring, and Managing Hypercalcemia Secondary to 13-Cis-Retinoic Acid Therapy in Children With High-risk Neuroblastoma.

    PubMed

    Chen, Suet Ching; Murphy, Dermot; Sastry, Jairam; Shaikh, Mohamad G

    2015-08-01

    13-cis-retinoic acid is an established component of treatment for children with high-risk neuroblastoma. However, significant hypercalcemia is increasingly recognized as a potentially life-threatening dosage-related side effect. We present 2 patients with significant hypercalcemia secondary to 13-cis-retinoic acid and their management, and identified the predictive factors for susceptibility to hypercalcemia. Assessing glomerular filtration rate and concomitant medication help predict individual susceptibility to hypercalcemia. Calcium levels should be monitored at days 1, 7, and 14 of each course of retinoic acid. An algorithm for the management of hypercalcemia during the affected and subsequent cycles of retinoid therapy is proposed.

  3. Transcriptional changes in organoculture of full-thickness human skin following topical application of all-trans retinoic acid.

    PubMed

    Gillbro, J M; Al-Bader, T; Westman, M; Olsson, M J; Mavon, A

    2014-06-01

    In this study, we developed an organoculture of human skin to investigate the effect of topical applied all-trans retinoic acid using a gene array approach. We could by using this approach confirm previous studies on genes activated by RA in keratinocyte monocultures and also provide new insights on genes that are relevant to RA-activation in human skin. The results in the present study show this model represent a valuable pre-clinical model for studying the effects of retinoids in skin. PMID:24697191

  4. Retinoic acid binding properties of the lipocalin member beta-lactoglobulin studied by circular dichroism, electronic absorption spectroscopy and molecular modeling methods.

    PubMed

    Zsila, Ferenc; Bikádi, Zsolt; Simonyi, Miklós

    2002-12-01

    Interaction between the Vitamin A derivative all-trans retinoic acid and the lipocalin member bovine beta-lactoglobulin (BLG) was studied by circular dichroism (CD) and electronic absorption spectroscopy at different pH values. In neutral and alkaline solutions achiral retinoic acid forms a non-covalent complex with the protein as indicated by the appearance of a negative Cotton effect around 347 nm associated to the narrowed and red shifted pi-pi(*) absorption band of the ligand. The induced optical activity is attributed to the helical distortion of the conjugated chain caused by the chiral protein binding environment. As the disappearing CD activity showed in the course of CD-pH titration experiment, retinoic acid molecules dissociate from BLG upon acidification but this release is completely reversible as proved by the reconstitution of the CD and absorption spectra after setting the pH back to neutral. This unique behavior of the complex is explained by the conformational change of BLG (Tanford transition) which involves a movement of the EF loop at the entrance of the central cavity from open to closed conformation in the course of pH lowering. From these results it was inferred that retinoic acid binds within the hydrophobic calyx of the beta-barrel. PMID:12429354

  5. Retinoic acid has different effects on UCP1 expression in mouse and human adipocytes

    PubMed Central

    2013-01-01

    Background Increased adipose thermogenesis is being considered as a strategy aimed at preventing or reversing obesity. Thus, regulation of the uncoupling protein 1 (UCP1) gene in human adipocytes is of significant interest. Retinoic acid (RA), the carboxylic acid form of vitamin A, displays agonist activity toward several nuclear hormone receptors, including RA receptors (RARs) and peroxisome proliferator-activated receptor δ (PPARδ). Moreover, RA is a potent positive regulator of UCP1 expression in mouse adipocytes. Results The effects of all-trans RA (ATRA) on UCP1 gene expression in models of mouse and human adipocyte differentiation were investigated. ATRA induced UCP1 expression in all mouse white and brown adipocytes, but inhibited or had no effect on UCP1 expression in human adipocyte cell lines and primary human white adipocytes. Experiments with various RAR agonists and a RAR antagonist in mouse cells demonstrated that the stimulatory effect of ATRA on UCP1 gene expression was indeed mediated by RARs. Consistently, a PPARδ agonist was without effect. Moreover, the ATRA-mediated induction of UCP1 expression in mouse adipocytes was independent of PPARγ coactivator-1α. Conclusions UCP1 expression is differently affected by ATRA in mouse and human adipocytes. ATRA induces UCP1 expression in mouse adipocytes through activation of RARs, whereas expression of UCP1 in human adipocytes is not increased by exposure to ATRA. PMID:24059847

  6. Liver-specific cytochrome P450 CYP2C22 is a direct target of retinoic acid and a retinoic acid-metabolizing enzyme in rat liver.

    PubMed

    Qian, Linxi; Zolfaghari, Reza; Ross, A Catharine

    2010-07-01

    Several cytochrome P450 (CYP) enzymes catalyze the C4-hydroxylation of retinoic acid (RA), a potent inducer of cell differentiation and an agent in the treatment of several diseases. Here, we have characterized CYP2C22, a member of the rat CYP2C family with homology to human CYP2C8 and CYP2C9. CYP2C22 was expressed nearly exclusively in hepatocytes, where it was one of the more abundant mRNAs transcripts. In H-4-II-E rat hepatoma cells, CYP2C22 mRNA was upregulated by all-trans (at)-RA, and Am580, a nonmetabolizable analog of at-RA. In comparison, in primary human hepatocytes, at-RA increased CYP2C9 but not CYP2C8 mRNA. Analysis of the CYP2C22 promoter region revealed a RA response element (5'-GGTTCA-(n)5-AGGTCA-3') in the distal flanking region, which bound the nuclear hormone receptors RAR and RXR and which was required for transcriptional activation response of this promoter to RA in CYP2C22-luciferase-transfected RA-treated HepG2 cells. The cDNA-expressed CYP2C22 protein metabolized [3H]at-RA to more polar metabolites. While long-chain polyunsaturated fatty acids competed, 9-cis-RA was a stronger competitor. Our studies demonstrate that CYP2C22 is a high-abundance, retinoid-inducible, hepatic P450 with the potential to metabolize at-RA, providing additional insight into the role of the CYP2C gene family in retinoid homeostasis.

  7. Computer-aided design of a novel ligand for retinoic acid receptor in cancer chemotherapy

    NASA Astrophysics Data System (ADS)

    Silva, Carlos H. T. P.; Leopoldino, Andreia M.; Silva, Eloiza H. T.; Espinoza, V. A. A.; Taft, C. A.

    The isotypes of RAR and RXR are retinoic acid and retinoid X acid receptors, respectively, whose ligand-binding domain contains the ligand-dependent activation function, with distinct pharmacological targets for retinoids, involved in the treatment of various cancers and skin diseases. Due to the major challenge which cancer treatment and cure still imposes after many decades to the international scientific community, there is actually considerable interest in new ligands with increased bioactivity. We have focused on the retinoid acid receptor, which is considered an interesting target for drug design. In this work, we carried out density functional geometry optimizations and different docking procedures. We performed screening in a large database (hundreds of thousands of molecules which we optimized at the AM1 level) yielding a set of potential bioactive ligands. A new ligand was selected and optimized at the B3LYP/6-31G* level. A flexible docking program was used to investigate the interactions between the receptor and the new ligand. The result of this work is compared with several crystallographic ligands of RAR. Our theoretically more bioactive new ligand indicates stronger and more hydrogen bonds as well as hydrophobic interactions with the receptor.

  8. CHARACTERIZATION OF CYPS IN THE METABOLISM OF ALL TRANS RETINOIC ACID BY LIVER MICROSOMES FROM MICE TREATED WITH CONAZOLES

    EPA Science Inventory

    Conazoles are fungicides used in crop protection and as pharmaceuticals. Triadimefon and propiconazole are hepatotumorigenic in mice, while myclobutanil is not. Previous toxicogenomic studies suggest that alteration of the retinoic acid metabolism pathway may involve in conazole-...

  9. Reversible effect of all-trans-retinoic acid on AML12 hepatocyte proliferation and cell cycle progression

    EPA Science Inventory

    The role of all-trans-retinoic acid (atRA) in the regulation of cellular proliferation and differentiation is well documented. Numerous studies have established the cancer preventive propertiesofatRAwhichfunctionstoregulate levels ofcellcycleproteinsessentialfortheGliS transition...

  10. Exogenous Modulation of Retinoic Acid Signaling Affects Adult RGC Survival in the Frog Visual System after Optic Nerve Injury

    PubMed Central

    Duprey-Díaz, Mildred V.; Blagburn, Jonathan M.; Blanco, Rosa E.

    2016-01-01

    After lesions to the mammalian optic nerve, the great majority of retinal ganglion cells (RGCs) die before their axons have even had a chance to regenerate. Frog RGCs, on the other hand, suffer only an approximately 50% cell loss, and we have previously investigated the mechanisms by which the application of growth factors can increase their survival rate. Retinoic acid (RA) is a vitamin A-derived lipophilic molecule that plays major roles during development of the nervous system. The RA signaling pathway is also present in parts of the adult nervous system, and components of it are upregulated after injury in peripheral nerves but not in the CNS. Here we investigate whether RA signaling affects long-term RGC survival at 6 weeks after axotomy. Intraocular injection of all-trans retinoic acid (ATRA), the retinoic acid receptor (RAR) type-α agonist AM80, the RARβ agonist CD2314, or the RARγ agonist CD1530, returned axotomized RGC numbers to almost normal levels. On the other hand, inhibition of RA synthesis with disulfiram, or of RAR receptors with the pan-RAR antagonist Ro-41-5253, or the RARβ antagonist LE135E, greatly reduced the survival of the axotomized neurons. Axotomy elicited a strong activation of the MAPK, STAT3 and AKT pathways; this activation was prevented by disulfiram or by RAR antagonists. Finally, addition of exogenous ATRA stimulated the activation of the first two of these pathways. Future experiments will investigate whether these strong survival-promoting effects of RA are mediated via the upregulation of neurotrophins. PMID:27611191

  11. Human renal mesangial cells are a target for the anti-inflammatory action of 9-cis retinoic acid

    PubMed Central

    Manzano, V Moreno; Muñoz, J C Sepúlveda; Jiménez, J Rodriguez; Puyol, M Rodriguez; Puyol, D Rodriguez; Kitamura, M; Cazaña, F J Lucio

    2000-01-01

    Mesangial cells play an active role in the inflammatory response to glomerular injury. We have studied in cultured human mesangial cells (CHMC) several effects of 9-cis retinoic acid (9-cRA), an activator of both retinoic acid receptors (RARs) and retinoid X receptors (RXRs). 9-cRA inhibited foetal calf serum-induced CHMC proliferation. It also prevented CHMC death induced by the inflammatory mediator H2O2. This preventive effect was not due to any increase in H2O2 catabolism and it persisted even when both catalase and glutathione synthesis were inhibited. Finally, 9-cRA diminished monocyte adhesion to FCS-stimulated CHMC. Interestingly, the retinoid also inhibited in FCS-stimulated cells the protein expression of two mesangial adhesion molecules, fibronectin and osteopontin, but it did not modify the protein expression of intercellular adhesion molecule-1 and vascular adhesion molecule-1. All major RARs and RXRs isotypes were expressed in CHMC regardless of the presence or absence of 9-cRA. Transcripts to RAR-α, RAR-β and RXR-α increased after incubation with 9-cRA whereas RXR-γ was inhibited, suggesting a major role for RARs and RXRs in 9-cRA-anti-inflammatory effects. 9-cRA was toxic only at 50 μM (a concentration 50–5000 times higher than required for the effects above). Cell death occurred by apoptosis, whose onset was associated with a pronounced increase in catalase activity and reduced glutathione content, being more effectively induced by all-trans retinoic acid. Modulation of the oxidant/antioxidant balance failed to inhibit apoptosis. We conclude that mesangial cells might be a target for the treatment of inflammatory glomerulopathies with 9-cRA. PMID:11139446

  12. Exogenous Modulation of Retinoic Acid Signaling Affects Adult RGC Survival in the Frog Visual System after Optic Nerve Injury.

    PubMed

    Duprey-Díaz, Mildred V; Blagburn, Jonathan M; Blanco, Rosa E

    2016-01-01

    After lesions to the mammalian optic nerve, the great majority of retinal ganglion cells (RGCs) die before their axons have even had a chance to regenerate. Frog RGCs, on the other hand, suffer only an approximately 50% cell loss, and we have previously investigated the mechanisms by which the application of growth factors can increase their survival rate. Retinoic acid (RA) is a vitamin A-derived lipophilic molecule that plays major roles during development of the nervous system. The RA signaling pathway is also present in parts of the adult nervous system, and components of it are upregulated after injury in peripheral nerves but not in the CNS. Here we investigate whether RA signaling affects long-term RGC survival at 6 weeks after axotomy. Intraocular injection of all-trans retinoic acid (ATRA), the retinoic acid receptor (RAR) type-α agonist AM80, the RARβ agonist CD2314, or the RARγ agonist CD1530, returned axotomized RGC numbers to almost normal levels. On the other hand, inhibition of RA synthesis with disulfiram, or of RAR receptors with the pan-RAR antagonist Ro-41-5253, or the RARβ antagonist LE135E, greatly reduced the survival of the axotomized neurons. Axotomy elicited a strong activation of the MAPK, STAT3 and AKT pathways; this activation was prevented by disulfiram or by RAR antagonists. Finally, addition of exogenous ATRA stimulated the activation of the first two of these pathways. Future experiments will investigate whether these strong survival-promoting effects of RA are mediated via the upregulation of neurotrophins. PMID:27611191

  13. Specificity in the synergism between retinoic acid and EGF on the growth of adult human skin fibroblasts

    SciTech Connect

    Harper, R.A. )

    1988-10-01

    Vitamin A (retinol) and five retinoids were tested for their ability to enhance epidermal growth factor (EGF) stimulation of adult human skin fibroblast growth in vitro. The retinoids utilized in this study were RO-1-5488 (all-trans-retinoic acid), RO-4-3780 (13-cis-retinoic acid), RO-10-9359, RO-10-1670, and RO-21-6583. Retinol and each retinoid were capable of stimulating fibroblast growth alone (0-86%), while 13-cis and all-trans-retinoic acid were the most potent in potentiating the EGF promotion of fibroblast growth. Since retinoic acid might enhance the EGF stimulation of cell growth by increasing either EGF receptor number or binding affinity, the binding of {sup 125}I-labeled EGF was carried out in the presence of retinoic acid and the data were subjected to a Scatchard-type analysis. No change in EGF receptor number or affinity was seen in the presence of retinoic acid. The data indicate a specific interaction between retinoid acid and EGF which results in the potentiation of the EGF-stimulated cell growth. Furthermore, the mechanism of this interaction does not seem to involve the initial binding of EGF to its plasma membrane receptor or the available number of EGF receptors located on the cell surface.

  14. Anti-apoptotic role of retinoic acid in the inner ear of noise-exposed mice

    SciTech Connect

    Ahn, Joong Ho; Kang, Hun Hee; Kim, Young-Jin; Chung, Jong Woo . E-mail: jwchung@amc.seoul.kr

    2005-09-23

    Exposure to loud noise can induce temporary or permanent hearing loss, and acoustic trauma is the major cause of hearing impairment in industrial nations. However, the mechanisms underlying the death of hair cells after acoustic trauma remain unclear. In addition to its involvement in cellular stress and apoptosis, the c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase family, is involved in cell survival, transformation, embryonic morphogenesis, and differentiation. JNK is primarily activated by various environmental stresses including noise, and the phenotypic result appears be to cell death. All-trans retinoic acid (ATRA) is an active metabolite of vitamin A that regulates a wide range of biological processes, including cell proliferation, differentiation, and morphogenesis. We evaluated the role of ATRA in preserving hearing in mice exposed to noise that can induce permanent hearing loss. Mice fed with ATRA before and during 3 consecutive days of noise exposure had a more preserved hearing threshold than mice fed sesame oil or saline. Histological and TUNEL staining of the cochlea showed significantly enhanced preservation of the organ of Corti, including outer hair cells and relatively low apoptotic nuclei, in mice-fed ATRA than in mice-fed sesame oil or saline. Phospho-JNK immunohistochemistry showed that ATRA inhibited the activation of JNK. These results suggest that ATRA has an anti-apoptotic effect on cochleae exposed to noise.

  15. Evidence for the presence of a retinoic acid receptor in rat osteosarcoma cells

    SciTech Connect

    Atkins, K.B.; Beitz, D.C. ); Horst, R.L.; Reinhardt, T.A. )

    1990-02-26

    Research has shown that ROS 17/2.8 cells respond to retinoic acid (RA) and do not express the cellular binding protein (CRABP) for RA. Initial experiments indicated the presence of a cytosolic and nuclear RA-binding activity. Both cytosolic and nuclear extracts were centrifuged (230,000g), and the supernatants labeled with ({sup 3}H)-RA{plus minus}100-fold excess RA. Sucrose gradient analysis of the nuclear extract showed a specific RA-binding activity sedimenting at 3.3S. Scatchard analysis of the nuclear extract showed a single binding component with an apparent K{sub d} of 10{sup {minus}9}M and an estimate of 1,700-3,000 copies/cell. The molecular weight of putative RAR was estimated to be 51KD by gel filtration. The cytosolic RA-binding activity co-sediments (2.0S) on a sucrose gradient with the cytosolic RA-binding activity from rat testis. Scatchard analysis resulted in an apparent Kd of 10{sup {minus}8}M with an estimated 60,000 copies of CRABP/cell. These data indicate ROS 17/2.8 cells express both RAR and CRABP.

  16. 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

  17. Altered sensitivity to ellagic acid in neuroblastoma cells undergoing differentiation with 12-O-tetradecanoylphorbol-13-acetate and all-trans retinoic acid.

    PubMed

    Alfredsson, Christina Fjæraa; Rendel, Filip; Liang, Qui-Li; Sundström, Birgitta E; Nånberg, Eewa

    2015-12-01

    Ellagic acid has previously been reported to induce reduced proliferation and activation of apoptosis in several tumor cell lines including our own previous data from non-differentiated human neuroblastoma SH-SY5Y cells. The aim of this study was now to investigate if in vitro differentiation with the phorbol ester 12-O- tetradecanoylphorbol-13-acetate or the vitamin A derivative all-trans retinoic acid altered the sensitivity to ellagic acid in SH-SY5Y cells. The methods used were cell counting and LDH-assay for evaluation of cell number and cell death, flow cytometric analysis of SubG1- and TUNEL-analysis for apoptosis and western blot for expression of apoptosis-associated proteins. In vitro differentiation was shown to reduce the sensitivity to ellagic acid with respect to cell detachment, loss of viability and activation of apoptosis. The protective effect was phenotype-specific and most prominent in all-trans retinoic acid-differentiated cultures. Differentiation-dependent up-regulation of Bcl-2 and integrin expression is introduced as possible protective mechanisms. The presented data also point to a positive correlation between proliferative activity and sensitivity to ellagic-acid-induced cell detachment. In conclusion, the presented data emphasize the need to consider degree of neuronal differentiation and phenotype of neuroblastoma cells when discussing a potential pharmaceutical application of ellagic acid in tumor treatment.

  18. The effect of topical retinoic acid (Airol) in the treatment of tinea versicolor.

    PubMed

    Handojo, I; Subagjo, B; Hadi, S

    1977-03-01

    A clinical trial with retinoic acid (Airol) cream 0.05% applied topically was carried out on 50 patients suffering from tinea versicolor allocated to a random procedure. The results, judged in terms of cure rate, incidence of relapse and tolerance were very satisfactory. As regards the above mentioned criteria for a successful treatment, there was no significant difference between the lotion and cream groups. Repigmentation of the affected skin after retinoic acid occurred in a relatively shorter period compared with other anti-fungal preparations, especially when simultaneously exposed to sunlight. The therapeutic action on dermatophytes was discussed. It was pointed out that patients suffering from tinea versicolor are predisposed to dermatophyte infections and that cleanliness of the skin is a simple but essential way of preventing contamination with Malassezia furfur.

  19. Neuralization of mouse embryonic stem cells in alginate hydrogels under retinoic acid and SAG treatment.

    PubMed

    Delivopoulos, Evangelos; Shakesheff, Kevin M; Peto, Heather

    2015-08-01

    This paper examines the differentiation of a mouse embryonic stem cell line (CGR8) into neurons, under retinoic acid (RA) and smoothened agonist (SAG) treatment. When stem cells underwent through an embryoid body (EB) formation stage, dissociation and seeding on glass coverslips, immunofluorescent labelling for neuronal markers (Nestin, b-Tubulin III, MAP2) revealed the presence of both immature neural progenitors and mature neurons. Undifferentiated CGR8 were also encapsulated in tubular, alginate-gelatin hydrogels and incubated in differentiation media containing retinoic acid (RA) and smoothened agonist (SAG). Cryo-sections of the hydrogel tubes were positive for Nestin, Pax6 and b-Tubulin III, verifying the presence of neurons and neural progenitors. Provided neural induction can be more precisely directed in the tubular hydrogels, these scaffolds will become a powerful model of neural tube development in embryos and will highlight potential strategies for spinal cord regeneration. PMID:26737053

  20. Retinoic acid signaling in cancer: The parable of acute promyelocytic leukemia.

    PubMed

    Ablain, Julien; de Thé, Hugues

    2014-11-15

    Inevitably fatal some 40 years, acute promyelocytic leukemia (APL) can now be cured in more than 95% of cases. This clinical success story is tightly linked to tremendous progress in our understanding of retinoic acid (RA) signaling. The discovery of retinoic acid receptor alpha (RARA) was followed by the cloning of the chromosomal translocations driving APL, all of which involve RARA. Since then, new findings on the biology of nuclear receptors have progressively enlightened the basis for the clinical efficacy of RA in APL. Reciprocally, the disease offered a range of angles to approach the cellular and molecular mechanisms of RA action. This virtuous circle contributed to make APL one of the best-understood cancers from both clinical and biological standpoints. Yet, some important questions remain unanswered including how lessons learnt from RA-triggered APL cure can help design new therapies for other malignancies. PMID:25130873

  1. Retinoic acid signaling in cancer: The parable of acute promyelocytic leukemia.

    PubMed

    Ablain, Julien; de Thé, Hugues

    2014-11-15

    Inevitably fatal some 40 years, acute promyelocytic leukemia (APL) can now be cured in more than 95% of cases. This clinical success story is tightly linked to tremendous progress in our understanding of retinoic acid (RA) signaling. The discovery of retinoic acid receptor alpha (RARA) was followed by the cloning of the chromosomal translocations driving APL, all of which involve RARA. Since then, new findings on the biology of nuclear receptors have progressively enlightened the basis for the clinical efficacy of RA in APL. Reciprocally, the disease offered a range of angles to approach the cellular and molecular mechanisms of RA action. This virtuous circle contributed to make APL one of the best-understood cancers from both clinical and biological standpoints. Yet, some important questions remain unanswered including how lessons learnt from RA-triggered APL cure can help design new therapies for other malignancies.

  2. Retinoic acid receptor alpha mediates growth inhibition by retinoids in human colon carcinoma HT29 cells.

    PubMed

    Nicke, B; Kaiser, A; Wiedenmann, B; Riecken, E O; Rosewicz, S

    1999-08-11

    Although retinoids have been suggested to inhibit chemically induced colon carcinogenesis, the molecular mechanisms underlying retinoid-mediated growth regulation in colon carcinoma cells are unknown. Therefore, we investigated the biological effects of retinoids on growth in HT29 colon carcinoma cells. All-trans retinoic acid (ATRA) treatment of HT29 cells resulted in a profound inhibition of anchorage-independent growth without biochemical or morphological evidence for induction of differentiation. Treatment with the selective RARalpha agonist Ro 40-6055 completely mimicked the effects of ATRA on growth and transactivation of a betaRAREx2-luciferase reporter construct, while RARbeta- and gamma-specific analogues were ineffective. Furthermore, ATRA-regulated growth and transactivation could be completely blocked by a RARalpha-selective receptor antagonist. Thus, ATRA potently inhibits anchorage-independent growth in HT29 cells and this effect is mainly if not exclusively mediated by the retinoic acid receptor alpha.

  3. Ethanol modulates the synthesis and catabolism of retinoic acid in the rat prostate.

    PubMed

    Fioruci-Fontanelli, Beatriz Aparecida; Chuffa, Luiz Gustavo A; Mendes, Leonardo O; Pinheiro, Patricia Fernanda F; Justulin, Luis Antônio; Felisbino, Sérgio Luis; Martinez, Francisco Eduardo

    2015-06-01

    All-trans retinoic acid (atRA) maintains physiological stability of the prostate, and we reported that ethanol intake increases atRA in the rat prostate; however the mechanisms underlying these changes are unknown. We evaluated the impact of a low- and high-dose ethanol intake (UChA and UChB strains) on atRA metabolism in the dorsal and lateral prostate. Aldehyde dehydrogenase (ALDH) subtype 1A3 was increased in the dorsal prostate of UChA animals while ALDH1A1 and ALDH1A2 decreased in the lateral prostate. In UChB animals, ALDH1A1, ALDH1A2, and ALDH1A3 increased in the dorsal prostate, and ALDH1A3 decreased in the lateral prostate. atRA levels increased with the low activity of CYP2E1 and decreased with high CYP26 activity in the UChB dorsal prostate. Conversely, atRA was found to decrease when the activity of total CYP was increased in the UChA lateral prostate. Ethanol modulates the synthesis and catabolism of atRA in the prostate in a concentration-dependent manner.

  4. Cytochrome P450s in the Regulation of Cellular Retinoic Acid Metabolism

    PubMed Central

    Ross, A. Catharine; Zolfaghari, Reza

    2013-01-01

    The active metabolite of vitamin A, retinoic acid (RA), is a powerful regulator of gene transcription. RA is also a therapeutic drug. The oxidative metabolism of RA by certain members of the cytochrome P450 (CYP) superfamily helps to maintain tissue RA concentrations within appropriate bounds. The CYP26 family—CYP26A1, CYP26B1, and CYP26C1—is distinguished by being both regulated by and active toward all-trans-RA (at-RA) while being expressed in different tissue-specific patterns. The CYP26A1 gene is regulated by multiple RA response elements. CYP26A1 is essential for embryonic development, whereas CYP26B1 is essential for postnatal survival as well as germ cell development. Enzyme kinetic studies have demonstrated that several CYP proteins are capable of metabolizing at-RA; however, it is likely that CYP26A1 plays a major role in RA clearance. Thus, pharmacological approaches to limiting the activity of CYP26 enzymes may extend the half-life of RA and could be useful clinically in the future. PMID:21529158

  5. Retinoic Acid and LTP Recruit Postsynaptic AMPA-Receptors Using Distinct SNARE-Dependent Mechanisms

    PubMed Central

    Arendt, Kristin L.; Zhang, Yingsha; Jurado, Sandra; Malenka, Robert C.; Südhof, Thomas C.; Chen, Lu

    2015-01-01

    SUMMARY Retinoic acid- (RA-) dependent homeostatic plasticity and NMDA-receptor-dependent LTP, a form of Hebbian plasticity, both enhance synaptic strength by increasing the abundance of postsynaptic AMPA receptors (AMPARs). However, it is unclear whether the molecular mechanisms mediating AMPAR-trafficking during homeostatic and Hebbian plasticity differ, and unknown how RA-signaling impacts Hebbian plasticity. Here, we show that RA increases postsynaptic AMPAR-abundance by an activity-dependent mechanism that requires a unique SNARE-dependent fusion machinery different from that mediating LTP. Specifically, RA-induced AMPAR-trafficking did not involve complexin, which activates SNARE complexes containing syntaxin-1 or -3 but not complexes containing syntaxin-4, whereas LTP required complexin. Moreover, RA-induced AMPAR trafficking utilized the Q-SNARE syntaxin-4 whereas LTP utilized syntaxin-3; both additionally required the Q-SNARE SNAP-47 and the R-SNARE synatobrevin-2. Finally, acute RA treatment blocked subsequent LTP expression, probably by increasing AMPAR-trafficking. Thus, RA-induced homeostatic plasticity involves a novel, activity-dependent postsynaptic AMPAR-trafficking pathway mediated by a unique SNARE-dependent fusion machinery. PMID:25843403

  6. [Folliculitis nuchae scleroticans--successful treatment with 13-cis-retinoic acid (isotretinoin)].

    PubMed

    Stieler, W; Senff, H; Jänner, M

    1988-11-01

    Acne keloidalis nuchae is characterized by keloidal papules and plaques. The lesions are located on the occipital scalp and posterior neck. This rare therapy-resistant condition is nearly always seen in men, particularly in negroes. Advanced stages of the disease require surgical excision with split-thickness skin grafts or treatment with a CO2 laser. Oral therapy with 13-cis-retinoic acid (isotretinoin) in a 23-year-old white man resulted in remarkable improvement within a few weeks.

  7. Retinoic acid-induced developmental defects are mediated by RARbeta/RXR heterodimers in the pharyngeal endoderm.

    PubMed

    Matt, Nicolas; Ghyselinck, Norbert B; Wendling, Olivia; Chambon, Pierre; Mark, Manuel

    2003-05-01

    Fusion and hypoplasia of the first two branchial arches, a defect typically observed in retinoic acid (RA) embryopathy, is generated in cultured mouse embryos upon treatment with BMS453, a synthetic compound that exhibits retinoic acid receptor beta (RARbeta) agonistic properties in transfected cells. By contrast, no branchial arch defects are observed following treatment with synthetic retinoids that exhibit RARalpha or RARgamma agonistic properties. The BMS453-induced branchial arch defects are mediated through RAR activation, as they are similar to those generated by a selective pan-RAR agonist, are prevented by a selective pan-RAR antagonist and cannot be mimicked by exposure to a pan-RXR agonist alone. They are enhanced in the presence of a pan-RXR agonist, and cannot be generated in Rarb-null embryos. Furthermore, they are accompanied, in the morphologically altered region, by ectopic expression of Rarb and of several other direct RA target genes. Therefore, craniofacial abnormalities characteristic of the RA embryopathy are mediated through ectopic activation of RARbeta/RXR heterodimers, in which the ligand-dependent activity of RXR is subordinated to that of RARbeta. Endodermal cells lining the first two branchial arches respond to treatment with the RARbeta agonist, in contrast to neural crest cells and ectoderm, which suggests that a faulty endodermal regionalization is directly responsible for RA-induced branchial arch dysmorphologies. Additionally, we provide the first in vivo evidence that the synthetic RARbeta agonist BMS453 exhibits an antagonistic activity on the two other RAR isotypes. PMID:12668623

  8. Myeloid differentiation and retinoblastoma phosphorylation changes in HL-60 cells induced by retinoic acid receptor- and retinoid X receptor-selective retinoic acid analogs.

    PubMed

    Brooks, S C; Kazmer, S; Levin, A A; Yen, A

    1996-01-01

    The ability of subtypes of retinoic acid receptors (RARs) and retinoid X receptors (RXRs) singly and in combination to elicit myeloid differentiation, G1/0-specific growth arrest, and retinoblastoma (RB) tumor suppressor protein dephosphorylation was determined in the human myeloblastic leukemia cell line HL-60 using subtype-selective retinoic acid (RA) analogs. RA analogs that selectively bind only to RARs (Am580 and/or TTNPB) or to RXRs (Ro 25-6603, SR11237, and/or SR11234) did not elicit the above-mentioned three cellular responses. In contrast, simultaneous treatment with both an RAR-selective ligand (Am580 or TTNPB) and an RXR-selective ligand (Ro 25-6603, SR11237, or SR11234) induced all three cellular processes. An RAR alpha-selective ligand used with an RXR-selective ligand generated the same responses as did all-trans RA or 9-cis RA, which affect both families of receptors, suggesting an important role for RAR alpha among RAR subtypes in eliciting cellular response. Consistent with this finding, the RAR alpha antagonist, Ro 41-5253, reduced the level of the cellular responses elicited by treatment with an RAR alpha-selective ligand plus RXR-selective ligand. The coupling of the shift of RB to its hypophosphorylated form with G1/0 arrest and differentiation in response to ligands is consistent with a possible role of RB as a downstream target or effector of RAR alpha and RXR in combination.

  9. Ubiquitin/proteasome pathway regulates levels of retinoic acid receptor gamma and retinoid X receptor alpha in human keratinocytes.

    PubMed

    Boudjelal, M; Wang, Z; Voorhees, J J; Fisher, G J

    2000-04-15

    Repeated exposure of human skin to solar UV radiation leads to premature aging (photoaging) and skin cancer. UV-induced skin damage can be ameliorated by all-trans retinoic acid treatment. The actions of retinoic acid in skin keratinocytes are mediated primarily by nuclear retinoic acid receptor gamma (RARgamma) and retinoid X receptor alpha (RXRalpha). We found that exposure of cultured primary human keratinocytes to UV irradiation (30 mJ/cm2) substantially reduced (50-90%) RARgamma and RXRalpha mRNA and protein within 8 h. The rates of disappearance of RARgamma and RXRalpha proteins after UV exposure or treatment with the protein synthesis inhibitor cycloheximide were similar. UV irradiation did not increase the rate of breakdown of RARgamma or RXRalpha but rather reduced their rate of synthesis. The addition of proteasome inhibitors MG132 and LLvL, but not the lysosomal inhibitor E64, prevented loss of RARgamma and RXRalpha proteins after exposure of keratinocytes to either UV radiation or cycloheximide. Soluble extracts from nonirradiated or UV-irradiated keratinocytes possessed similar levels of proteasome activity that degraded RARgamma and RXRalpha proteins in vitro. Furthermore, RARgamma and RXRalpha were polyubiquitinated in intact cells. RXRalpha was found to contain two proline, glutamate/aspartate, serine, and threonine (PEST) motifs, which confer rapid turnover of many short-lived regulatory proteins that are degraded by the ubiquitin/proteasome pathway. However, the PEST motifs in RXRalpha did not function to regulate its stability, because deletion of the PEST motifs individually or together did not alter ubiquitination or proteasome-mediated degradation of RXRalpha. These results demonstrate that loss of RARgamma and RXRalpha proteins after UV irradiation results from degradation via the ubiquitin/proteasome pathway. Taken together, the data here indicate that ubiquitin/proteasome-mediated breakdown is an important mechanism regulating the levels of

  10. Expression of retinoic acid receptor alpha mRNA in human leukemia cells.

    PubMed

    Largman, C; Detmer, K; Corral, J C; Hack, F M; Lawrence, H J

    1989-07-01

    The expression of the newly described human retinoic acid receptor alpha (RAR alpha) in six nonlymphoid and six lymphoid leukemia cell lines and nine freshly obtained samples of leukemia cells from patients with acute nonlymphoid leukemia was assessed by Northern blot analysis, using a full length cDNA clone of RAR alpha as probe. RAR alpha was expressed in all 12 cell lines and in all fresh leukemia samples as two major transcripts of 2.6 and 3.5 kb in size. Levels of RAR alpha expression and transcript sizes in retinoid-sensitive cells (such as HL60 or fresh promyelocytic leukemia cells) were not different from those in other samples. Moreover, expression of RAR alpha was not significantly modulated by exposure to cis-retinoic acid (cisRA) in either cisRA-responsive or unresponsive cells. By using a 3' fragment of the RAR alpha gene as a probe, we confirmed that the transcripts visualized did not represent the homologous RAR beta gene. RAR alpha appears to be expressed in most human leukemia cells regardless of the type of biologic response to retinoic acid.

  11. Aberrant distribution of junctional complex components in retinoic acid receptor alpha-deficient mice

    PubMed Central

    Chung, Sanny S W; Choi, Cindy; Wang, Xiangyuan; Hallock, Loretta; Wolgemuth, Debra J

    2009-01-01

    Retinoic acid receptor alpha (RARα)-deficient mice are sterile, with abnormalities in the progression of spermatogenesis and spermiogenesis. In the present study, we investigated whether defective retinoid signaling involved at least in part, disrupted cell-cell interactions. Hypertonic fixation approaches revealed defects in the integrity of the Sertoli-cell barrier in the tubules of RARα-deficient testes. Dye transfer experiments further revealed that coupling between cells from the basal to adluminal compartments was aberrant. There were also differences in the expression of several known retinoic acid (RA)-responsive genes encoding structural components of tight junctions and gap junctions. Immunostaining demonstrated a delay in the incorporation of zonula occludens (ZO-1), a peripheral component protein of tight junctions, into the Sertoli cell tight junctions. Markedly reduced expression of connexin-40 in mutant pachytene spermatocytes and round spermatids was found by in situ hybridization. An ectopic distribution of vimentin and disrupted cyclic expression of vimentin, which is usually tightly regulated during spermiogenesis, was found in RARα-deficient testes at all ages examined. Thus, the specific defects in spermiogenesis in RARα-deficient testes may correlate with a disrupted cyclic expression of RA-responsive structural components, including vimentin, a down-regulation of connexin-40 in spermatogenic cells, and delayed assembly of ZO-1 into Sertoli cell tight junctions. Interestingly, bioinformatic analysis revealed that many genes that are components of tight junctions and gap junctions contained potential retinoic acid response element binding sites. PMID:19937743

  12. Induction of carnitine palmitoyl transferase 1 and fatty acid oxidation by retinoic acid in HepG2 cells.

    PubMed

    Amengual, Jaume; Petrov, Petar; Bonet, M Luisa; Ribot, Joan; Palou, Andreu

    2012-11-01

    The vitamin A derivative retinoic acid (RA) is an important regulator of mammalian adiposity and lipid metabolism, primarily acting at the gene expression level through nuclear receptors of the RA receptor (RAR) and retinoid X receptor (RXR) subfamilies. Here, we studied cell-autonomous effects of RA on fatty acid metabolism, particularly fatty acid oxidation, in human hepatoma HepG2 cells. Exposure to all-trans RA (ATRA) up-regulated the expression of carnitine palmitoyl transferase-1 (CPT1-L) in HepG2 cells in a dose- and time-dependent manner, and increased cellular oxidation rate of exogenously added radiolabeled palmitate. The effect of ATRA on gene expression of CPT1-L was: dependent on ongoing transcription, reproduced by both 9-cis RA and a pan-RXR agonist (but not a pan-RAR agonist) and abolished following RXRα partial siRNA-mediated silencing. CPT1-L gene expression was synergistically induced in HepG2 cells simultaneously exposed to ATRA and a selective peroxisome proliferator-activated receptor α agonist. We conclude that ATRA treatment enhances fatty acid catabolism in hepatocytes through RXR-mediated mechanisms that likely involve the transactivation of the PPARα:RXR heterodimer. Knowledge of agents and nutrient-derivatives capable of enhancing substrate oxidation systemically and specifically in liver, and their mechanisms of action, may contribute to new avenues of prevention and treatment of fatty liver, obesity and other metabolic syndrome-related disorders. PMID:22871568

  13. Arginine of retinoic acid receptor beta which coordinates with the carboxyl group of retinoic acid functions independent of the amino acid residues responsible for retinoic acid receptor subtype ligand specificity.

    PubMed

    Zhang, Zeng Ping; Hutcheson, Juliet M; Poynton, Helen C; Gabriel, Jerome L; Soprano, Kenneth J; Soprano, Dianne Robert

    2003-01-15

    The biological actions of retinoic acid (RA) are mediated by retinoic acid receptors (RARalpha, RARbeta, and RARgamma) and retinoid X receptors (RXRalpha, RXRbeta, and RXRgamma). Consistent with the X-ray crystal structures of RARalpha and RARgamma, site-directed mutagenesis studies have demonstrated the importance of a conserved Arg residue (alphaArg(276), betaArg(269), and gammaArg(278)) for coordination with the carboxyl group of RA. However, mutation of Arg(269) to Ala in RARbeta causes only a 3- to 6-fold increase in the K(d) for RA and EC(50) in RA-dependent transcriptional transactivation assays while the homologous mutation in either RARalpha or RARgamma causes a 110-fold and a 45-fold increase in EC(50) value, respectively. To further investigate the nature of this difference, we prepared mutant RARs to determine the effect of conversion of betaR269A to a mutant which mimics either RARalpha ligand selectivity (betaA225S/R269A) or RARgamma ligand selectivity (betaI263M/R269A/V338A). Our results demonstrate that in RARbeta mutants that acquire either RARalpha or RARgamma ligand specificity the Arg(269) position responsible for coordination with the carboxyl group of retinoids continued to function like that of RARbeta. Furthermore, three mutant receptors (betaA225S/R269A, betaA225S/F279, and alphaF286A) were found to have a greater than wild-type affinity for the RARalpha-selective ligand Am580. Finally, a homology-based computer model of the ligand binding domain (LBD) of RARbeta and the X-ray crystal structures of the LBD of both RARalpha and RARgamma are used to describe potential mechanisms responsible for the increased affinity of some mutants for Am580 and for the difference in the effect of mutation of Arg(269) in RARbeta compared to its homologous Arg in RARalpha and RARgamma.

  14. 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.

  15. Embryonic retinoic acid synthesis is essential for early mouse post-implantation development.

    PubMed

    Niederreither, K; Subbarayan, V; Dollé, P; Chambon, P

    1999-04-01

    A number of studies have suggested that the active derivative of vitamin A, retinoic acid (RA), may be important for early development of mammalian embryos. Severe vitamin A deprivation in rodents results in maternal infertility, precluding a thorough investigation of the role of RA during embryogenesis. Here we show that production of RA by the retinaldehyde dehydrogenase-2 (Raldh2) enzyme is required for mouse embryo survival and early morphogenesis. Raldh2 is an NAD-dependent aldehyde dehydrogenase with high substrate specificity for retinaldehyde. Its pattern of expression during mouse development has suggested that it may be responsible for embryonic RA synthesis. We generated a targeted disruption of the mouse Raldh2 gene and found that Raldh2-/- embryos, which die at midgestation without undergoing axial rotation (body turning), exhibit shortening along the anterioposterior axis and do not form limb buds. Their heart consists of a single, medial, dilated cavity. Their frontonasal region is truncated and their otocysts are severely reduced. These defects result from a block in embryonic RA synthesis, as shown by the lack of activity of RA-responsive transgenes, the altered expression of an RA-target homeobox gene and the near full rescue of the mutant phenotype by maternal RA administration. Our data establish that RA synthesized by the post-implantation mammalian embryo is an essential developmental hormone whose lack leads to early embryo death. PMID:10192400

  16. Tributyltin and triphenyltin inhibit osteoclast differentiation through a retinoic acid receptor-dependent signaling pathway

    SciTech Connect

    Yonezawa, Takayuki; Hasegawa, Shin-ichi; Ahn, Jae-Yong; Cha, Byung-Yoon; Teruya, Toshiaki; Hagiwara, Hiromi; Nagai, Kazuo; Woo, Je-Tae; E-mail: jwoo@isc.chubu.ac.jp

    2007-03-30

    Organotin compounds, such as tributyltin (TBT) and triphenyltin (TPT), have been widely used in agriculture and industry. Although these compounds are known to have many toxic effects, including endocrine-disrupting effects, their effects on bone resorption are unknown. In this study, we investigated the effects of organotin compounds, such as monobutyltin (MBT), dibutyltin (DBT), TBT, and TPT, on osteoclast differentiation using mouse monocytic RAW264.7 cells. MBT and DBT had no effects, whereas TBT and TPT dose-dependently inhibited osteoclast differentiation at concentrations of 3-30 nM. Treatment with a retinoic acid receptor (RAR)-specific antagonist, Ro41-5253, restored the inhibition of osteoclastogenesis by TBT and TPT. TBT and TPT reduced receptor activator of nuclear factor-{kappa}B ligand (RANKL) induced nuclear factor of activated T cells (NFAT) c1 expression, and the reduction in NFATc1 expression was recovered by Ro41-5253. Our results suggest that TBT and TPT suppress osteoclastogenesis by inhibiting RANKL-induced NFATc1 expression via an RAR-dependent signaling pathway.

  17. Retinoic acid alleviates Con A-induced hepatitis and differentially regulates effector production in NKT cells.

    PubMed

    Lee, Kyoo-A; Song, You Chan; Kim, Ga-Young; Choi, Gyeyoung; Lee, Yoon-Sook; Lee, Jung-Mi; Kang, Chang-Yuil

    2012-07-01

    Retinoic acid (RA) is a diverse regulator of immune responses. Although RA promotes natural killer T (NKT) cell activation in vitro by increasing CD1d expression on antigen-presenting cells (APCs), the direct effects of RA on NKT-cell responses in vivo are not known. In the present study, we demonstrated the effect of RA on the severity of Con A-induced hepatitis and molecular changes of NKT cells. First, we demonstrated that Con A-induced liver damage was ameliorated by RA. In correlation with cytokine levels in serum, RA regulated the production of IFN-γ and IL-4 but not TNF-α by NKT cells without influencing the NKT-cell activation status. However, RA did not alleviate α-GalCer-induced liver injury, even though it reduced IFN-γ and IL-4 but not TNF-α levels in serum. This regulation was also detected when liver mononuclear cells (MNCs) or NKT hybridoma cells were treated with RA in vitro. The regulatory effect of RA on NKT cells was mediated by RAR-α, and RA reduced the phosphorylation of MAPK. These results suggest that RA differentially modulates the production of effector cytokines by NKT cells in hepatitis, and the suppressive effect of RA on hepatitis varies with the pathogenic mechanism of liver injury.

  18. Aldose Reductase acts as a Selective Derepressor of PPARγ and Retinoic Acid Receptor

    PubMed Central

    Thiagarajan, Devi; Ananthakrishnan, Radha; Zhang, Jinghua; O’Shea, Karen M.; Quadri, Nosirudeen; Li, Qing; Sas, Kelli; Jing, Xiao; Rosario, Rosa; Pennathur, Subramaniam; Schmidt, Ann Marie; Ramasamy, Ravichandran

    2016-01-01

    Summary Histone deacetylase 3 (HDAC3), a chromatin modifying enzyme, requires association with the deacetylase containing domain (DAD) of the nuclear receptor co-repressors NCOR1 and SMRT for its stability and activity. Here we show that aldose reductase (AR), the rate-limiting enzyme of the polyol pathway, competes with HDAC3 to bind the NCOR1/SMRT DAD. Increased AR expression leads to HDAC3 degradation followed by increased PPARγ signaling resulting in lipid accumulation in the heart. AR also downregulates expression of nuclear corepressor complex cofactors including Gps2 and Tblr1, thus affecting activity of the nuclear corepressor complex itself. Though AR reduces HDAC3-corepressor complex formation, it specifically de-represses the retinoic acid receptor (RAR), but not other nuclear receptors such as the thyroid receptor (TR) and liver X receptor (LXR). In summary, this work defines a distinct role for AR in lipid and retinoid metabolism through HDAC3 regulation and consequent de-repression of PPARγ and RAR. PMID:27052179

  19. Different effects of the treatment with AGN 193836 and 9-cis-retinoic acid in breast cancer cells.

    PubMed

    Isnardi, L; Raffo, P; Emionite, L; Chardraratna, R A; Toma, S

    1999-01-01

    Retinoid effects have been well studied in different cellular models, and their in vitro action on breast cancer is well known. Much less is known about the function of the different retinoid receptors in mediating retinoid activity in this and other cellular models. In order to better understand these biological mechanisms, several synthetic compounds have been produced, that have specific binding affinity for selected nuclear receptors, and their effect has been evaluated and confronted with that of classic compounds able to bind to different receptors. The aim of this study was the evaluation of the biological activities in breast cancer cell lines of one of these new compounds, AGN 193836, with a very selective binding affinity (selective agonist retinoid) for one single retinoic acid receptor (RAR alpha), in respect to a classic retinoid able to bind to a broad spectrum of retinoic acid receptors (pan-agonist retinoid), 9cRA. Our results clearly indicate that the selective retinoid retains most of the biological activities of the pan-agonist compound, but its effect is probably aggravated by fewer side-effects in vivo: This evidences indicate that selective-agonist retinoids are an interesting research field for the future, not only because of their speculative interest, but also in view of future clinical applications.

  20. A putative G-protein-coupled receptor, H218, is down-regulated during the retinoic acid-induced differentiation of F9 embryonal carcinoma cells.

    PubMed

    Li, Y; MacLennan, A J; Rogers, M B

    1998-03-15

    We have previously cloned a novel guanine nucleotide-binding protein (G-protein)-coupled receptor, H218, that has sequence similarity to a lysophosphatidic acid receptor, edg2. We present here Northern analysis indicating that the H218 mRNA is expressed in undifferentiated F9 embryonal carcinoma cells. The H218 message is down-regulated and its stability is decreased during retinoic acid- and dibutyryl cAMP-induced differentiation. Treatment by various receptor-selective retinoids indicated that retinoic acid receptor beta or gamma signaling, but not retinoid X receptor activation, is required for the down-regulation of H218 mRNA. Activation of the H218 receptor may contribute to the phenotype of undifferentiated F9 embryonal carcinoma cells.

  1. Comparison of efficacy of chemical peeling with 25% trichloroacetic acid and 0.1% retinoic acid for facial rejuvenation

    PubMed Central

    Gurel, Mehmet Salih; Gungor, Sule; Tekeli, Omur; Canat, Dilek

    2016-01-01

    Introduction Skin aging is a problem which negatively affects the psyche of the person, social relations, as well as work life and health and which compels the patients to find appropriate treatment methods. Numerous treatment methods have been developed in order to delay aging and to reduce the aging effects in addition to having a younger, healthier and more beautiful facial appearance. Aim To compare the efficiency, cosmetic results and possible adverse effects of the peeling treatment with 25% trichloroacetic acid (TCA) and 0.1% retinoic acid for facial rejuvenation in patients presenting with skin aging. Material and methods Fifty female patients in total presenting with medium and advanced degree skin aging were subject to this study. Two separate treatment groups were formed; the first group underwent chemical skin treatment with 25% TCA while the other group was applied with 0.1% retinoic acid treatment. Following the 4 months’ treatment the patients were controlled three times in total for post lesional hypopigmentation, hyperpigmentation, scars, skin irritation and other possible changes per month. The pretreatment and first follow-up visit, and final control images were comparatively evaluated by three observers via specific software. Results The healing rates of the group subject to retinoic acid were statistically higher (p < 0.05) compared to patients in the TCA group in the final follow-up visit following the treatment according to the first and second observers. On the other hand, according to the third observer, patients applied with retinoic acid presented with higher healing rates compared to those treated with TCA, however; this rate was not statistically significant (p > 0.05). The frequency of TCA- and retinoic acid-associated adverse effects was similar in both groups (p > 0.05). As a result of both treatments, a reduction in the quality of life scores as well as a pronounced recovery (p = 0.001) in the quality of life of those patients

  2. Early mouse caudal development relies on crosstalk between retinoic acid, Shh and Fgf signalling pathways.

    PubMed

    Ribes, Vanessa; Le Roux, Isabelle; Rhinn, Muriel; Schuhbaur, Brigitte; Dollé, Pascal

    2009-02-01

    The progressive generation of embryonic trunk structures relies on the proper patterning of the caudal epiblast, which involves the integration of several signalling pathways. We have investigated the function of retinoic acid (RA) signalling during this process. We show that, in addition to posterior mesendoderm, primitive streak and node cells transiently express the RA-synthesizing enzyme Raldh2 prior to the headfold stage. RA-responsive cells (detected by the RA-activated RARE-lacZ transgene) are additionally found in the epiblast layer. Analysis of RA-deficient Raldh2(-/-) mutants reveals early caudal patterning defects, with an expansion of primitive streak and mesodermal markers at the expense of markers of the prospective neuroepithelium. As a result, many genes involved in neurogenesis and/or patterning of the embryonic spinal cord are affected in their expression. We demonstrate that RA signalling is required at late gastrulation stages for mesodermal and neural progenitors to respond to the Shh signal. Whole-embryo culture experiments indicate that the proper response of cells to Shh requires two RA-dependent mechanisms: (1) a balanced antagonism between Fgf and RA signals, and (2) a RA-mediated repression of Gli2 expression. Thus, an interplay between RA, Fgf and Shh signalling is likely to be an important mechanism underpinning the tight regulation of caudal embryonic development. PMID:19168680

  3. Importance of ALDH1A enzymes in determining human testicular retinoic acid concentrations

    PubMed Central

    Arnold, Samuel L.; Kent, Travis; Hogarth, Cathryn A.; Schlatt, Stefan; Prasad, Bhagwat; Haenisch, Michael; Walsh, Thomas; Muller, Charles H.; Griswold, Michael D.; Amory, John K.; Isoherranen, Nina

    2015-01-01

    Retinoic acid (RA), the active metabolite of vitamin A, is required for spermatogenesis and many other biological processes. RA formation requires irreversible oxidation of retinal to RA by aldehyde dehydrogenase enzymes of the 1A family (ALDH1A). While ALDH1A1, ALDH1A2, and ALDH1A3 all form RA, the expression pattern and relative contribution of these enzymes to RA formation in the testis is unknown. In this study, novel methods to measure ALDH1A protein levels and intrinsic RA formation were used to accurately predict RA formation velocities in individual human testis samples and an association between RA formation and intratesticular RA concentrations was observed. The distinct localization of ALDH1A in the testis suggests a specific role for each enzyme in controlling RA formation. ALDH1A1 was found in Sertoli cells, while only ALDH1A2 was found in spermatogonia, spermatids, and spermatocytes. In the absence of cellular retinol binding protein (CRBP)1, ALDH1A1 was predicted to be the main contributor to intratesticular RA formation, but when CRBP1 was present, ALDH1A2 was predicted to be equally important in RA formation as ALDH1A1. This study provides a comprehensive novel methodology to evaluate RA homeostasis in human tissues and provides insight to how the individual ALDH1A enzymes mediate RA concentrations in specific cell types. PMID:25502770

  4. Phenotypic Characterization of Retinoic Acid Differentiated SH-SY5Y Cells by Transcriptional Profiling

    PubMed Central

    Korecka, Joanna A.; van Kesteren, Ronald E.; Blaas, Eva; Spitzer, Sonia O.; Kamstra, Jorke H.; Smit, August B.; Swaab, Dick F.; Verhaagen, Joost; Bossers, Koen

    2013-01-01

    Multiple genetic and environmental factors play a role in the development and progression of Parkinson’s disease (PD). The main neuropathological hallmark of PD is the degeneration of dopaminergic (DAergic) neurons in the substantia nigra pars compacta. To study genetic and molecular contributors to the disease process, there is a great need for readily accessible cells with prominent DAergic features that can be used for reproducible in vitro cellular screening. Here, we investigated the molecular phenotype of retinoic acid (RA) differentiated SH-SY5Y cells using genome wide transcriptional profiling combined with gene ontology, transcription factor and molecular pathway analysis. We demonstrated that RA induces a general neuronal differentiation program in SH-SY5Y cells and that these cells develop a predominantly mature DAergic-like neurotransmitter phenotype. This phenotype is characterized by increased dopamine levels together with a substantial suppression of other neurotransmitter phenotypes, such as those for noradrenaline, acetylcholine, glutamate, serotonin and histamine. In addition, we show that RA differentiated SH-SY5Y cells express the dopamine and noradrenalin neurotransmitter transporters that are responsible for uptake of MPP(+), a well known DAergic cell toxicant. MPP(+) treatment alters mitochondrial activity according to its proposed cytotoxic effect in DAergic neurons. Taken together, RA differentiated SH-SY5Y cells have a DAergic-like phenotype, and provide a good cellular screening tool to find novel genes or compounds that affect cytotoxic processes that are associated with PD. PMID:23724009

  5. Regulation by retinoic acid of acylation-stimulating protein and complement C3 in human adipocytes.

    PubMed Central

    Scantlebury, T; Sniderman, A D; Cianflone, K

    2001-01-01

    Acylation-stimulating protein (ASP), a product of complement C3, stimulates triacylglycerol synthesis in adipocytes. Previous studies have identified transthyretin, associated with chylomicrons, as a stimulator of C3 and ASP production. Since both transthyretin and chylomicrons transport retinyl ester/retinol, our goal was to investigate whether retinoic acid (RA) could be a potential hormonal mediator of the effect. Inhibitors of protein synthesis and protein secretion eliminated the stimulatory effects of chylomicrons on both C3 and ASP production in human differentiated adipocytes, suggesting that de novo protein synthesis and secretion are both required. Incubation with chylomicrons increased C3 mRNA levels (37+/-1.5%). RA alone or with chylomicrons had a stimulatory effect on C3 production (29-fold at 16.6 nM RA) and ASP production. An RA receptor antagonist blocked stimulation of C3 mRNA and C3 secretion by both RA and chylomicrons. Finally, RA and chylomicrons activated a 1.8 kb C3-promoter-luciferase construct transfected into 3T3-F442 and 3T3-L1 cells (by 41+/-0.2% and 69+/-0.3% respectively), possibly via RA receptor half-sites identified by sequence analysis. This is the first evidence documenting stimulation by RA of the C3 gene. Thus we propose RA as a novel cellular trigger in chylomicrons that subsequently results in increased ASP production by adipocytes after a meal. PMID:11368771

  6. Retinoic acid regulation of the Mesp-Ripply feedback loop during vertebrate segmental patterning.

    PubMed

    Moreno, Tanya A; Jappelli, Roberto; Izpisúa Belmonte, Juan Carlos; Kintner, Chris

    2008-03-15

    The Mesp bHLH genes play a conserved role during segmental patterning of the mesoderm in the vertebrate embryo by specifying segmental boundaries and anteroposterior (A-P) segmental polarity. Here we use a xenotransgenic approach to compare the transcriptional enhancers that drive expression of the Mesp genes within segments of the presomitic mesoderm (PSM) of different vertebrate species. We find that the genomic sequences upstream of the mespb gene in the pufferfish Takifugu rubripes (Tr-mespb) are able to drive segmental expression in transgenic Xenopus embryos while those from the Xenopus laevis mespb (Xl-mespb) gene drive segmental expression in transgenic zebrafish. In both cases, the anterior segmental boundary of transgene expression closely matches the expression of the endogenous Mesp genes, indicating that many inputs into segmental gene expression are highly conserved. By contrast, we find that direct retinoic acid (RA) regulation of endogenous Mesp gene expression is variable among vertebrate species. Both Tr-mespb and Xl-mespb are directly upregulated by RA, through a complex, distal element. By contrast, RA represses the zebrafish Mesp genes. We show that this repression is mediated, in part, by RA-mediated activation of the Ripply genes, which together with Mesp genes form an RA-responsive negative feedback loop. These observations suggest that variations in a direct response to RA input may allow for changes in A-P patterning of the segments in different vertebrate species.

  7. Potential for use of retinoic acid as an oral vaccine adjuvant

    PubMed Central

    Mwanza-Lisulo, Mpala; Kelly, Paul

    2015-01-01

    Despite the heavy burden of diarrhoeal disease across much of the tropical world, only two diarrhoea-causing pathogens, cholera and rotavirus, are the target of commercially available vaccines. Oral vaccines are generally less immunogenic than the best parenteral vaccines, but the reasons for this are still debated. Over the past decade, several lines of evidence from work in experimental animals have suggested that all-trans retinoic acid (ATRA), a form of vitamin A which is highly transcriptionally active, can alter the homing receptor expression of T lymphocytes. Increased expression of α4β7 integrin and the chemokine receptor CCR9 following exposure to ATRA can be used to redirect T cells to the gut. Early work in human volunteers suggests that oral ATRA administration 1 h prior to dosing with oral typhoid vaccine can augment secretion of specific IgA against vaccine-derived lipopolysaccharide into gut secretions. In this review, we set out the rationale for using ATRA in this way and assess its likely applicability to vaccination programmes for protection of children in low-income countries from the considerable mortality caused by diarrhoeal disease. Comparison of recent work in experimental animals, non-human primates and men suggests that a more detailed understanding of ATRA dosage and kinetics will be important to taking forward translational work into human vaccinology. PMID:25964457

  8. 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.

  9. Transcription factor TLX1 controls retinoic acid signaling to ensure spleen development

    PubMed Central

    Lenti, Elisa; Farinello, Diego; Penkov, Dmitry; Castagnaro, Laura; Lavorgna, Giovanni; Wuputra, Kenly; Tjaden, Naomi E. Butler; Bernassola, Francesca; Caridi, Nicoletta; Wagner, Michael; Kozinc, Katja; Niederreither, Karen; Blasi, Francesco; Pasini, Diego; Trainor, Paul A.

    2016-01-01

    The molecular mechanisms that underlie spleen development and congenital asplenia, a condition linked to increased risk of overwhelming infections, remain largely unknown. The transcription factor TLX1 controls cell fate specification and organ expansion during spleen development, and Tlx1 deletion causes asplenia in mice. Deregulation of TLX1 expression has recently been proposed in the pathogenesis of congenital asplenia in patients carrying mutations of the gene-encoding transcription factor SF-1. Herein, we have shown that TLX1-dependent regulation of retinoic acid (RA) metabolism is critical for spleen organogenesis. In a murine model, loss of Tlx1 during formation of the splenic anlage increased RA signaling by regulating several genes involved in RA metabolism. Uncontrolled RA activity resulted in premature differentiation of mesenchymal cells and reduced vasculogenesis of the splenic primordium. Pharmacological inhibition of RA signaling in Tlx1-deficient animals partially rescued the spleen defect. Finally, spleen growth was impaired in mice lacking either cytochrome P450 26B1 (Cyp26b1), which results in excess RA, or retinol dehydrogenase 10 (Rdh10), which results in RA deficiency. Together, these findings establish TLX1 as a critical regulator of RA metabolism and provide mechanistic insights into the molecular determinants of human congenital asplenia. PMID:27214556

  10. Apoptotic and anti-proliferative effects of all-trans retinoic acid

    SciTech Connect

    Zamora, Monica; Ortega, Juan Alberto; Alana, Lide; Vinas, Octavi; Mampel, Teresa . E-mail: tmampel@ub.edu

    2006-06-10

    We examined the apoptotic and anti-proliferative effects of all-trans retinoic acid (atRA) in HeLa cells. Our results demonstrated that HeLa cells were more sensitive to the anti-proliferative effects of atRA than to its apoptotic effects. Furthermore, we demonstrated that caspase inhibition attenuates cell death but does not alter the atRA-dependent reduction in cell proliferation, which suggests that atRA-induced apoptosis is independent of the arrest in cell proliferation. To check whether ANT proteins mediated these atRA effects, we transiently transfected cells with expression vectors encoding for individual ANT (adenine nucleotide translocase 1-3). Our results revealed that ANT1 and ANT3 over-expressing HeLa cells increased their atRA sensitivity. Thus, our results not only demonstrate the different functional activities of ANT isoforms, but also contribute to a better understanding of the properties of atRA as an anti-tumoral agent used in cancer therapy.

  11. Retinol Promotes In Vitro Growth of Proximal Colon Organoids through a Retinoic Acid-Independent Mechanism

    PubMed Central

    Nibe, Yoichi; Akiyama, Shintaro; Matsumoto, Yuka; Nozaki, Kengo; Fukuda, Masayoshi; Hayashi, Ayumi; Mizutani, Tomohiro; Oshima, Shigeru; Watanabe, Mamoru; Nakamura, Tetsuya

    2016-01-01

    Retinol (ROL), the alcohol form of vitamin A, is known to control cell fate decision of various types of stem cells in the form of its active metabolite, retinoic acid (RA). However, little is known about whether ROL has regulatory effects on colonic stem cells. We examined in this study the effect of ROL on the growth of murine normal colonic cells cultured as organoids. As genes involved in RA synthesis from ROL were differentially expressed along the length of the colon, we tested the effect of ROL on proximal and distal colon organoids separately. We found that organoid forming efficiency and the expression level of Lgr5, a marker gene for colonic stem cells were significantly enhanced by ROL in the proximal colon organoids, but not in the distal ones. Interestingly, neither retinaldehyde (RAL), an intermediate product of the ROL-RA pathway, nor RA exhibited growth promoting effects on the proximal colon organoids, suggesting that ROL-dependent growth enhancement in organoids involves an RA-independent mechanism. This was confirmed by the observation that an inhibitor for RA-mediated gene transcription did not abrogate the effect of ROL on organoids. This novel role of ROL in stem cell maintenance in the proximal colon provides insights into the mechanism of region-specific regulation for colonic stem cell maintenance. PMID:27564706

  12. Retinoic acid receptors recognize the mouse genome through binding elements with diverse spacing and topology.

    PubMed

    Moutier, Emmanuel; Ye, Tao; Choukrallah, Mohamed-Amin; Urban, Sylvia; Osz, Judit; Chatagnon, Amandine; Delacroix, Laurence; Langer, Diana; Rochel, Natacha; Moras, Dino; Benoit, Gerard; Davidson, Irwin

    2012-07-27

    Retinoic acid receptors (RARs) heterodimerize with retinoid X receptors (RXRs) and bind to RA response elements (RAREs) in the regulatory regions of their target genes. Although previous studies on limited sets of RA-regulated genes have defined canonical RAREs as direct repeats of the consensus RGKTCA separated by 1, 2, or 5 nucleotides (DR1, DR2, DR5), we show that in mouse embryoid bodies or F9 embryonal carcinoma cells, RARs occupy a large repertoire of sites with DR0, DR8, and IR0 (inverted repeat 0) elements. Recombinant RAR-RXR binds these non-canonical spacings in vitro with comparable affinities to DR2 and DR5. Most DR8 elements comprise three half-sites with DR2 and DR0 spacings. This specific half-site organization constitutes a previously unrecognized but frequent signature of RAR binding elements. In functional assays, DR8 and IR0 elements act as independent RAREs, whereas DR0 does not. Our results reveal an unexpected diversity in the spacing and topology of binding elements for the RAR-RXR heterodimer. The differential ability of RAR-RXR bound to DR0 compared to DR2, DR5, and DR8 to mediate RA-dependent transcriptional activation indicates that half-site spacing allosterically regulates RAR function.

  13. CDX4 and retinoic acid interact to position the hindbrain-spinal cord transition.

    PubMed

    Chang, Jessie; Skromne, Isaac; Ho, Robert K

    2016-02-15

    The sub-division of the posterior-most territory of the neural plate results in the formation of two distinct neural structures, the hindbrain and the spinal cord. Although many of the molecular signals regulating the development of these individual structures have been elucidated, the mechanisms involved in delineating the boundary between the hindbrain and spinal cord remain elusive. Two molecules, retinoic acid (RA) and the Cdx4 transcription factor have been previously implicated as important regulators of hindbrain and spinal cord development, respectively. Here, we provide evidence that suggests multiple regulatory interactions occur between RA signaling and the Cdx4 transcription factor to establish the anterior-posterior (AP) position of the transition between the hindbrain and spinal cord. Using chemical inhibitors to alter RA concentrations and morpholinos to knock-down Cdx4 function in zebrafish, we show that Cdx4 acts to prevent RA degradation in the presumptive spinal cord domain by suppressing expression of the RA degradation enzyme, Cyp26a1. In the hindbrain, RA signaling modulates its own concentration by activating the expression of cyp26a1 and inhibiting the expansion of cdx4. Therefore, interactions between Cyp26a1 and Cdx4 modulate RA levels along the AP axis to segregate the posterior neural plate into the hindbrain and spinal cord territories.

  14. Proteome alteration of U251 human astrocytoma cell after inhibiting retinoic acid synthesis.

    PubMed

    Zhang, Ming; Wan, Chunling; Ji, Baohu; Zhang, Zhao; Zhu, Hui; Tian, Nan; La, Yujuan; Huang, Ke; Jiang, Lei; He, Guang; Gao, Linhan; Zhao, Xinzhi; Shi, Yongyong; Huang, Gang; Feng, Guoyin; He, Lin

    2009-03-01

    Retinoic acid (Ra) is crucial for the patterning and neuronal differentiation in the central nervous system (CNS). Ra deficiency in animals disrupts the motor activities and memory abilities. The molecular mechanisms underlying these behavior abnormalities remain largely unknown. In the current study, we treated the astrocytoma cells with citral, an inhibitor of Ra synthesis. We analyzed the differences in the protein concentrations between the treated and untreated astrocytoma cells by two-dimensional gel electrophoresis (2-DE), Imagemaster software, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In total, 39 of 46 altered protein spots with significant mascot scores were identified representing 36 proteins, that were involved in significantly altered glutamate metabolism, lipid metabolism, mitochondrial function, and oxidative stress response by Ingenuity Pathway Analysis (IPA). Altered 3-phosphoglycerate dehydrogenase (PHGDH) was also observed in western blot. These data provide some clues for explaining the behavioral changes caused by Ra deficiency, and support the hypothesis that Ra signaling is associated with some symptoms of neurodegenerative disorders and schizophrenia. PMID:19089318

  15. Practical synthesis of a chromene analog for use as a retinoic acid receptor alpha antagonist lead compound.

    PubMed

    Jetson, Rachael; Malik, Neha; Luniwal, Amarjit; Chari, Venkatesh; Ratnam, Manohar; Erhardt, Paul

    2013-05-01

    Retinoic acid receptor alpha (RARα) selective compounds may guide the design of drugs that can be used in conjunction with hormonal adjuvant therapy in the treatment of breast cancer. Herein we report a modified synthesis of a known RARα antagonist, 2-fluoro-4-[[[8-bromo-2,2-dimethyl-4-(4-methylphenyl)chroman-6-yl]carbonyl]amino]benzoic acid and a synthesis of its unknown, desfluoro analog, 4-[[[8-bromo-2,2-dimethyl-4-(4-methylphenyl)chroman-6-yl]carbonyl]amino]benzoic acid. The modified route allows for facile reaction workups, increased yields, lower cost and incorporates a green alternative step. Structure-activity relationship studies determined through functional cell-based assays, demonstrated antagonism to RARα for both compounds. Molecular modeling within the RARα binding pocket was used to compare binding interactions of the desfluoro analog to a known RAR antagonist.

  16. Loss of MT1-MMP causes cell senescence and nuclear defects which can be reversed by retinoic acid.

    PubMed

    Gutiérrez-Fernández, Ana; Soria-Valles, Clara; Osorio, Fernando G; Gutiérrez-Abril, Jesús; Garabaya, Cecilia; Aguirre, Alina; Fueyo, Antonio; Fernández-García, María Soledad; Puente, Xose S; López-Otín, Carlos

    2015-07-14

    MT1-MMP (MMP14) is a collagenolytic enzyme located at the cell surface and implicated in extracellular matrix (ECM) remodeling. Mmp14(-/-) mice present dwarfism, bone abnormalities, and premature death. We demonstrate herein that the loss of MT1-MMP also causes cardiac defects and severe metabolic changes, and alters the cytoskeleton and the nuclear lamina structure. Moreover, the absence of MT1-MMP induces a senescent phenotype characterized by up-regulation of p16(INK4a) and p21(CIP1/WAF) (1), increased activity of senescence-associated β-galactosidase, generation of a senescence-associated secretory phenotype, and somatotroph axis alterations. Consistent with the role of retinoic acid signaling in nuclear lamina stabilization, treatment of Mmp14(-/-) mice with all-trans retinoic acid reversed the nuclear lamina alterations, partially rescued the cell senescence phenotypes, ameliorated the pathological defects in bone, skin, and heart, and extended their life span. These results demonstrate that nuclear architecture and cell senescence can be modulated by a membrane protease, in a process involving the ECM as a key regulator of nuclear stiffness under cell stress conditions.

  17. Loss of MT1-MMP causes cell senescence and nuclear defects which can be reversed by retinoic acid

    PubMed Central

    Gutiérrez-Fernández, Ana; Soria-Valles, Clara; Osorio, Fernando G; Gutiérrez-Abril, Jesús; Garabaya, Cecilia; Aguirre, Alina; Fueyo, Antonio; Fernández-García, María Soledad; Puente, Xose S; López-Otín, Carlos

    2015-01-01

    MT1-MMP (MMP14) is a collagenolytic enzyme located at the cell surface and implicated in extracellular matrix (ECM) remodeling. Mmp14−/− mice present dwarfism, bone abnormalities, and premature death. We demonstrate herein that the loss of MT1-MMP also causes cardiac defects and severe metabolic changes, and alters the cytoskeleton and the nuclear lamina structure. Moreover, the absence of MT1-MMP induces a senescent phenotype characterized by up-regulation of p16INK4a and p21CIP1/WAF1, increased activity of senescence-associated β-galactosidase, generation of a senescence-associated secretory phenotype, and somatotroph axis alterations. Consistent with the role of retinoic acid signaling in nuclear lamina stabilization, treatment of Mmp14−/− mice with all-trans retinoic acid reversed the nuclear lamina alterations, partially rescued the cell senescence phenotypes, ameliorated the pathological defects in bone, skin, and heart, and extended their life span. These results demonstrate that nuclear architecture and cell senescence can be modulated by a membrane protease, in a process involving the ECM as a key regulator of nuclear stiffness under cell stress conditions. PMID:25991604

  18. Identification of Retinoic Acid in a High Content Screen for Agents that Overcome the Anti-Myogenic Effect of TGF-Beta-1

    PubMed Central

    Krueger, Chateen; Hoffmann, F. Michael

    2010-01-01

    Background Transforming growth factor beta 1 (TGF-β1) is an inhibitor of muscle cell differentiation that is associated with fibrosis, poor regeneration and poor function in some diseases of muscle. When neutralizing antibodies to TGF-β1 or the angiotensin II inhibitor losartan were used to reduce TGF-β1 signaling, muscle morphology and function were restored in mouse models of Marfan Syndrome and muscular dystrophy. The goal of our studies was to identify additional agents that overcome the anti-myogenic effect of TGF-β1. Methodology/Principal Findings A high-content cell-based assay was developed in a 96-well plate format that detects the expression of myosin heavy chain (MHC) in C2C12 cells. The assay was used to quantify the dose-dependent responses of C2C12 cell differentiation to TGF-β1 and to the TGF-β1 Type 1 receptor kinase inhibitor, SB431542. Thirteen agents previously described as promoting C2C12 differentiation in the absence of TGF-β1 were screened in the presence of TGF-β1. Only all-trans retinoic acid and 9-cis retinoic acid allowed a maximal level of C2C12 cell differentiation in the presence of TGF-β1; the angiotensin-converting enzyme inhibitor captopril and 10 nM estrogen provided partial rescue. Vitamin D was a potent inhibitor of retinoic acid-induced myogenesis in the presence of TGF-β1. TGF-β1 inhibits myoblast differentiation through activation of Smad3; however, retinoic acid did not inhibit TGF-β1-induced activation of a Smad3-dependent reporter gene in C2C12 cells. Conclusions/Significance Retinoic acid alleviated the anti-myogenic effect of TGF-β1 by a Smad3-independent mechanism. With regard to the goal of improving muscle regeneration and function in individuals with muscle disease, the identification of retinoic acid is intriguing in that some retinoids are already approved for human therapy. However, retinoids also have well-described adverse effects. The quantitative, high-content assay will be useful to screen for

  19. All-Trans Retinoic Acid Reduces Joint Adhesion Formation: An Experimental Study in Rats

    PubMed Central

    Wang, Yuguang; Zhang, Chao; Cheng, Huan; Douglas, Patricia; Wang, Zhiqiang; Lu, Yun

    2015-01-01

    Background Intra-articular adhesion is a common complication in post-surgical knees. The formation of post-surgical joint adhesion could lead to serious conditions. All-trans retinoic acid (ATRA) is a physiological metabolite of vitamin A that has a wide range of biological activities. The aim of the study was to verify the effects of (ATRA) in preventing adhesions in the post-operative rat knee. Material/Methods Eighty healthy adult male Wistar rats underwent femoral condyle-exposing surgery. After surgery, cotton pads soaked with the vehicle or various concentrations of ATRA (0.1%, 0.05%, 0.025%) were applied to the surgery site for 5 min. The post-surgical knee joints were fixed with micro-Kirschner wires in a flexed position for 4 weeks. The rats were killed 4 weeks after surgery. The effect of ATRA on the prevention of intra-articular adhesion was evaluated using histological analyses, hydroxyproline content, visual score, and inflammatory factor activity evaluation. Results No obvious postoperative complications or signs of infection in the rats were observed. None of the rats died before the scheduled time. The rats in the 0.1% ATRA group showed better outcomes, as suggested by the visual scores, hydroxyproline contents, and inflammatory factors expressional levels, than the other 2 groups. The local application of 0.1% ATRA was able to suppress adhesions, collagen expression, and inflammatory activity in the post-surgical rat knees. Conclusions In the rat knee surgery model, the application of intra-articular ATRA was able to decrease intra-articular scar adhesion formation, collagen expression, and inflammatory activities. ATRA was found to work in a dose-dependent manner, with 0.1% being possible optimal concentration. PMID:26044570

  20. The SCFA butyrate stimulates the epithelial production of retinoic acid via inhibition of epithelial HDAC.

    PubMed

    Schilderink, Ronald; Verseijden, Caroline; Seppen, Jurgen; Muncan, Vanesa; van den Brink, Gijs R; Lambers, Tim T; van Tol, Eric A; de Jonge, Wouter J

    2016-06-01

    In the intestinal mucosa, retinoic acid (RA) is a critical signaling molecule. RA is derived from dietary vitamin A (retinol) through conversion by aldehyde dehydrogenases (aldh). Reduced levels of short-chain fatty acids (SCFAs) are associated with pathological microbial dysbiosis, inflammatory disease, and allergy. We hypothesized that SCFAs contribute to mucosal homeostasis by enhancing RA production in intestinal epithelia. With the use of human and mouse epithelial cell lines and primary enteroids, we studied the effect of SCFAs on the production of RA. Functional RA conversion was analyzed by Adlefluor activity assays. Butyrate (0-20 mM), in contrast to other SCFAs, dose dependently induced aldh1a1 or aldh1a3 transcript expression and increased RA conversion in human and mouse epithelial cells. Epithelial cell line data were replicated in intestinal organoids. In these organoids, butyrate (2-5 mM) upregulated aldh1a3 expression (36-fold over control), whereas aldh1a1 was not significantly affected. Butyrate enhanced maturation markers (Mucin-2 and villin) but did not consistently affect stemness markers or other Wnt target genes (lgr5, olfm4, ascl2, cdkn1). In enteroids, the stimulation of RA production by SCFA was mimicked by inhibitors of histone deacetylase 3 (HDAC3) but not by HDAC1/2 inhibitors nor by agonists of butyrate receptors G-protein-coupled receptor (GPR)43 or GPR109A, indicating that butyrate stimulates RA production via HDAC3 inhibition. We conclude that the SCFA butyrate inhibits HDAC3 and thereby supports epithelial RA production. PMID:27151945

  1. Retinoic acid inhibits endometrial cancer cell growth via multiple genomic mechanisms.

    PubMed

    Cheng, You-Hong; Utsunomiya, Hiroki; Pavone, Mary Ellen; Yin, Ping; Bulun, Serdar E

    2011-04-01

    Previous studies have indicated that retinoic acid (RA) may be therapeutic for endometrial cancer. However, the downstream target genes and pathways triggered by ligand-activated RA receptor α (RARα) in endometrial cancer cells are largely unknown. In this study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, and immunoblotting assays were used to assess the roles of RA and the RA agonist (AM580) in the growth of endometrial cancer cells. Illumina-based microarray expression profiling of endometrial Ishikawa cells incubated with and without AM580 for 1, 3, and 6 h was performed. We found that both RA and AM580 markedly inhibited endometrial cancer cell proliferation, while knockdown of RARα could block AM580 inhibition. Knockdown of RARα significantly increased proliferating cell nuclear antigen and BCL2 protein levels. Incubation of Ishikawa cells with or without AM580 followed by microarray expression profiling showed that 12 768 genes out of 47 296 gene probes were differentially expressed with significant P values. We found that 90 genes were the most regulated genes with the most significant P value (P<0.0001) using F-test. We selected four highly regulated genes with diverse functions, namely G0S2, TNFAIP2, SMAD3, and NRIP1. Real-time PCR verified that AM580 highly regulated these genes, whereas chromatin immunoprecipitation-PCR assay demonstrated that ligand-activated RARα interacted with the promoter of these genes in intact endometrial cancer cells. AM580 also significantly altered 18 pathways including those related to cell growth, differentiation, and apoptosis. In conclusion, AM580 treatment of Ishikawa cells causes the differential expression of a number of RARα target genes and activation of signaling pathways. These pathways could, therefore, mediate the carcinogenesis of human endometrial cancer.

  2. 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.

  3. Molecular mechanism of 9-cis-retinoic acid inhibition of adipogenesis in 3T3-L1 cells.

    PubMed

    Sagara, Chiaki; Takahashi, Katsuhiko; Kagechika, Hiroyuki; Takahashi, Noriko

    2013-03-29

    Retinoic acid (RA) signaling is mediated by specific nuclear hormone receptors. Here we examined the effects of 9-cis-RA on adipogenesis in mouse preadipocyte 3T3-L1 cells. 9-cis-RA inhibits the lipid accumulation of adipogenetically induced 3T3-L1 cells. The complex of retinoid X receptor α (RXRα) with peroxisome proliferator-activated receptor γ (PPARγ) is a major transcription factor in the process of adipogenesis, and the levels of these molecules were decreased by 9-cis-RA treatment. A RXR pan-antagonist suppressed 9-cis-RA's inhibitory effects on adipogenesis, but not on the intracellular levels of both RXRα and PPARγ. These results suggest that 9-cis-RA could inhibit adipogenesis by activating RXR, and decrease both RXR and PPARγs levels in a RXR activation-independent manner. PMID:23485459

  4. Effect of dexamethasone and oxygen exposure on neonatal rat lung retinoic acid receptor proteins.

    PubMed

    McMenamy, K R; Anderson, M J; Zachman, R D

    1994-10-01

    Retinol deficiency in animal models results in histopathologic airway changes that appear similar to those found in human premature infants with bronchopulmonary dysplasia (BPD). Dexamethasone (DEX), a steroid now often used in the treatment of BPD, might potentially affect lung vitamin A homeostasis since it alters serum and liver retinoid stores in certain models. Our objective was to determine the effect of DEX on neonatal rat lung retinoid status and the binding of retinoic acid (RA) to cytosolic and nuclear receptor proteins. We examined this effect both in room air and when the animals breathed 95% oxygen (O2). Twenty-four 1-day-old rat pups received either 1 microgram/g DEX subcutaneously, an equal volume of normal saline (NS) subcutaneously at 0 (start experiment time), 24, and 48 hours, or no injection at all, and were sacrificed at 72 hours. Twelve rats in each treatment group were housed in room air and 12 in each group were exposed to > 95% O2 for the 3 day period. Lung and liver were analyzed for retinyl palmitate (RP). Nuclear retinoic acid receptor (RAR) and cellular retinoic acid binding protein (CRABP) were measured by specific binding assays. DEX decreased liver RP by 33-55% and rat pup lung RP by over 60%; it also decreased lung RAR binding (mean dpm/microgram protein +/- SEM) in both room air and oxygen groups: Air (11.2 +/- 1.0) vs. Air/DEX (4.6 +/- 1.3, n = 6; P < 0.01), and O2 (18.2 +/- 0.6) vs. O2/DEX (3.2 +/- 0.6, n = 6; P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7838622

  5. Acitretin systemic and retinoic acid 0.1% cream supression of basal cell carcinoma

    PubMed Central

    Zhang, Xi-Bao; Zhang, San-Quan; Li, Chang-Xing; Huang, Zhen-Ming; Luo, Yu-Wu

    2010-01-01

    Retinoids have been used for years as monotherapy and/or in combination for treatment and suppression of cutaneous malignancies in patients with basal cell nevus syndrome, xeroderma pigmentosum, or cutaneous T-cell lymphoma (CTCL) basal cell carcinoma (BCC). We report 4 cases with BCC confirmed by histopathology who were treated by short-term systemic acitretin combined with retinoic acid 0.1% cream. The 4 cases with BCC showed good response to the treatment without severe adverse effects during treatment and follow-up. The finding suggests that acitretin may be an appropriate treatment option for elderly patients who require less invasive treatment for BCC. PMID:25386240

  6. Premature physeal closure following 13-cis-retinoic acid and prolonged fenretinide administration in neuroblastoma.

    PubMed

    Steineck, Angela; MacKenzie, John D; Twist, Clare J

    2016-11-01

    Retinoid therapy has contributed to improved outcomes in neuroblastoma. Clinical trials of fenretinide report favorable toxicity and disease stabilization in patients with high risk (HR) neuroblastoma. Skeletal effects have been described with other retinoids, but not with fenretinide to date. Two patients with HR, metastatic, refractory neuroblastoma received protracted courses of oral fenretinide for more than 5 years' duration. Both developed premature long bone physeal closure, causing limb length discrepancies; their neuroblastoma remains in remission. The radiographic and clinical findings reported suggest these skeletal abnormalities may be a consequence of treatment with 13-cis-retinoic acid (13cisRA) followed by prolonged oral fenretinide exposure.

  7. Inhibition of ultraviolet-induced carcinogenesis by all-trans retinoic acid

    SciTech Connect

    Epstein, J.H.; Grekin, D.A.

    1981-03-01

    The effects of all-trans retinoic acid (RA) in 0.05%, 0.025% and 0.005% concentrations on ultraviolet (UV) induced carcinogenesis was investigated in the skin of Uscd strain hairless mice. A carcinogenic amount of UV energy was delivered over the 12-mo period of the study. The 0.025% and 0.005% RA solutions did not alter the development of cutaneous cancers. However, the 0.05% RA concentration significantly inhibited the tumor formation in this study.

  8. Retinoic acid improves a hybridoma culture in a fructose-based medium by up-regulation of fructose incorporation via retinoid nuclear receptors.

    PubMed

    Inoue, Yuichi; Kawahara, Hiroharu; Shirahata, Sanetaka; Sugimoto, Yasushi

    2006-09-01

    Fructose was focused on as an alternative sugar source to glucose in a hybridoma culture medium because it decreases lactate production during cultivation, leading to cell and product stability. But, not all human hybridoma cell lines grew well in a fructose-based serum-free medium. We found that the addition of all-trans-retinoic acid to the fructose-based medium improved the growth and monoclonal antibody production of hybridoma cell lines by up-regulation of fructose incorporation that represented increased expression of the fructose transporter, GLUT5. Selective activation of retinoid nuclear receptor by synthetic ligands showed that both retinoic acid receptors and retinoid X receptors might be related to the improvement of the fructose-based hybridoma culture. This study might be applicable to cell cultures susceptible to lactate and pH changes as well as hybridoma cultures.

  9. Regulation of alkaline phosphatase expression in a neonatal rat clonal calvarial cell strain by retinoic acid.

    PubMed

    Ng, K W; Gummer, P R; Michelangeli, V P; Bateman, J F; Mascara, T; Cole, W G; Martin, T J

    1988-02-01

    A clonal cell strain, UMR 201, was established from a culture of rat calvarial cells by the process of limiting dilution on a collagen substratum. One-day-old neonatal rat calvaria stripped of periosteum were placed on collagen in alpha-MEM with 10% fetal bovine serum (FBS). Cells that grew out from the calvaria were passaged eight times to select cells with the ability to proliferate in culture before cloning was attempted. Cells from the clonal strain were homogeneous in appearance with a doubling time in culture of about 24 hours. The UMR 201 cells formed predominantly type 1 collagen. When treated with retinoic acid (RA), all cells showed an intense staining for alkaline phosphatase (ALP). This effect of RA on the expression of ALP activity was reversible and was time and dose dependent. The earliest change was observed within 6 hours. In contrast, single and isolated clumps of untreated cells stained positively for ALP only when they were confluent. Coincubation with dactinomycin up to 3 hours after the addition of RA completely prevented the expression of ALP, whereas dactinomycin became progressively less effective when added at later times. This is interpreted as indicating a regulatory role of RA on the gene expression of ALP. Other hormones acting on bone, such as 1,25(OH)2 vitamin D3 and dexamethasone, also modulate ALP activity. The cells showed morphologic evidence of senescence after passage 12. Our preliminary studies showed that the UMR 201 cells had the characteristics of relatively undifferentiated mesenchymal cells.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. A Novel Bidirectional Interaction between endothelin-3 and Retinoic Acid in Rat Enteric Nervous System Precursors

    PubMed Central

    Gisser, Jonathan M.; Cohen, Ariella R.; Yin, Han; Gariepy, Cheryl E.

    2013-01-01

    Background Signaling through the endothelin receptor B (EDNRB) is critical for the development of the enteric nervous system (ENS) and mutations in endothelin system genes cause Hirschsprung’s aganglionosis in humans. Penetrance of the disease is modulated by other genetic factors. Mutations affecting retinoic acid (RA) signaling also produce aganglionosis in mice. Thus, we hypothesized that RA and endothelin signaling pathways may interact in controlling development of the ENS. Methods Rat immunoselected ENS precursor cells were cultured with the EDNRB ligand endothelin-3, an EDNRB-selective antagonist (BQ-788), and/or RA for 3 or 14 days. mRNA levels of genes related to ENS development, RA- and EDNRB-signaling were measured at 3 days. Proliferating cells and cells expressing neuronal, glial, and myofibroblast markers were quantified. Results Culture of isolated ENS precursors for 3 days with RA decreases expression of the endothelin-3 gene and that of its activation enzyme. These changes are associated with glial proliferation, a higher percentage of glia, and a lower percentage of neurons compared to cultures without RA. These changes are independent of EDNRB signaling. Conversely, EDNRB activation in these cultures decreases expression of RA receptors β and γ mRNA and affects the expression of the RA synthetic and degradative enzymes. These gene expression changes are associated with reduced glial proliferation and a lower percentage of glia in the culture. Over 14 days in the absence of EDNRB signaling, RA induces the formation of a heterocellular plexus replete with ganglia, glia and myofibroblasts. Conclusions A complex endothelin-RA interaction exists that coordinately regulates the development of rat ENS precursors in vitro. These results suggest that environmental RA may modulate the expression of aganglionosis in individuals with endothelin mutations. PMID:24040226

  11. Vitamin D interferes with transactivation of the growth hormone gene by thyroid hormone and retinoic acid.

    PubMed Central

    Garcia-Villalba, P; Jimenez-Lara, A M; Aranda, A

    1996-01-01

    The thyroid hormone, retinoic acid (RA), and vitamin D regulate gene expression by binding to similar receptors which act as ligand-inducible transcription factors. Incubation of pituitary GH4C1 cells with nanomolar concentrations of vitamin D markedly reduces the response of the rat growth hormone mRNA to thyroid hormone triiodothyronine (T3) and RA. The stimulation of growth hormone gene expression by both ligands is mediated by a common hormone response element (TREGH) present in the 5'-flanking region of the gene, and the inhibition caused by vitamin D is due to transcriptional interference of the vitamin D receptor on this DNA element. No inhibition of the basal promoter activity by the vitamin was observed. The response to T3 and RA of a heterologous promoter containing this element, the palindromic T3- and RA-responsive sequence TREPAL, or a direct repeat of the same motif is also inhibited by vitamin D. In contrast, vitamin D strongly induces the activity of constructs containing a vitamin D response element, and neither T3 nor RA reduces vitamin D-mediated transactivation. Transfection with an expression vector for the retinoid X receptor alpha (RXR alpha) increases transactivation by T3 and RA but does not abolish the inhibition caused by the vitamin. Gel retardation experiments show that the vitamin D receptor (VDR) as a heterodimer with RXR weakly binds to the T3- and RA-responsive elements. Additionally, VDR displaces binding of T3 and RA receptors in a dose-dependent manner. Our data suggest the formation of TR-VDR and RAR-VDR heterodimers with RXR. The fact that the same response element mediates opposite effects of at least four different nuclear receptors provides a greater complexity and flexibility of the transcriptional responses to their ligands. PMID:8524311

  12. Role of retinoic acid metabolizing cytochrome P450s, CYP26, in inflammation and cancer

    PubMed Central

    Stevison, Faith; Jing, Jing; Tripathy, Sasmita; Isoherranen, Nina

    2016-01-01

    Vitamin A (retinol) and its active metabolite, all-trans-retinoic acid (atRA), play critical roles in regulating the differentiation, growth and migration of immune cells. Similarly, as critical signaling molecules in the regulation of the cell cycle, retinoids are important in cancers. Concentrations of atRA are tightly regulated in tissues, predominantly by the availability of retinol, synthesis of atRA by ALDH1A enzymes and metabolism and clearance of atRA by CYP26 enzymes. The ALDH1A and CYP26 enzymes are expressed in several cell types in the immune system and in cancer cells. In the immune system the ALDH1A and CYP26 enzymes appear to modulate RA concentrations. Consequently, alterations in the activity of ALDH1A and CYP26 enzymes are expected to change disease outcomes in inflammation. There is increasing evidence from various disease models of intestinal and skin inflammation that treatment with atRA has a positive effect on disease markers. However, whether aberrant atRA concentrations or atRA synthesis and metabolism play a role in inflammatory disease development and progression is not well understood. In cancers, especially in acute promyelocytic leukemia and neuroblastoma, increasing intracellular concentrations of atRA appears to provide clinical benefit. Inhibition of the CYP26 enzymes to increase atRA concentrations and combat therapy resistance has been pursued as a drug target in these cancers. This chapter covers the current knowledge of how atRA and retinol regulate the immune system and inflammation, how retinol and atRA metabolism is altered in inflammation and cancer and what roles atRA metabolizing enzymes have in immune responses and cancers. PMID:26233912

  13. An Alternative Retinoic Acid-responsive Stra6 Promoter Regulated in Response to Retinol Deficiency*

    PubMed Central

    Laursen, Kristian B.; Kashyap, Vasundhra; Scandura, Joseph; Gudas, Lorraine J.

    2015-01-01

    Cellular uptake of vitamin A (retinol) is essential for many biological functions. The Stra6 protein binds the serum retinol-binding protein, RBP4, and acts in conjunction with the enzyme lecithin:retinol acyltransferase to facilitate retinol uptake in some cell types. We show that in embryonic stem (ES) cells and in some tissues, the Stra6 gene encodes two distinct mRNAs transcribed from two different promoters. Whereas both are all-trans-retinoic acid (RA)-responsive in ES cells, the downstream promoter contains a half-site RA response element (RARE) and drives an ∼13-fold, RA-associated increase in luciferase reporter activity. We employed CRISPR-Cas9 genome editing to show that the endogenous RARE is required for RA-induced transcription of both Stra6 isoforms. We further demonstrate that in ES cells, 1) both RARγ and RXRα are present at the Stra6 RARE; 2) RA increases co-activator p300 (KAT3B) binding and histone H3 Lys-27 acetylation at both promoters; 3) RA decreases Suz12 levels and histone H3 Lys-27 trimethylation epigenetic marks at both promoters; and 4) these epigenetic changes are diminished in the absence of RARγ. In the brains of WT mice, both the longer and the shorter Stra6 transcript (Stra6L and Stra6S, respectively) are highly expressed, whereas these transcripts are found only at low levels in RARγ−/− mice. In the brains of vitamin A-deficient mice, both Stra6L and Stra6S levels are decreased. In contrast, in the vitamin A-deficient kidneys, the Stra6L levels are greatly increased, whereas Stra6S levels are decreased. Our data show that kidneys respond to retinol deficiency by differential Stra6 promoter usage, which may play a role in the retention of retinol when vitamin A is low. PMID:25544292

  14. All-trans-retinoic Acid Modulates the Plasticity and Inhibits the Motility of Breast Cancer Cells

    PubMed Central

    Zanetti, Adriana; Affatato, Roberta; Centritto, Floriana; Fratelli, Maddalena; Kurosaki, Mami; Barzago, Maria Monica; Bolis, Marco; Terao, Mineko; Garattini, Enrico; Paroni, Gabriela

    2015-01-01

    All-trans-retinoic acid (ATRA) is a natural compound proposed for the treatment/chemoprevention of breast cancer. Increasing evidence indicates that aberrant regulation of epithelial-to-mesenchymal transition (EMT) is a determinant of the cancer cell invasive and metastatic behavior. The effects of ATRA on EMT are largely unknown. In HER2-positive SKBR3 and UACC812 cells, showing co-amplification of the ERBB2 and RARA genes, ATRA activates a RARα-dependent epithelial differentiation program. In SKBR3 cells, this causes the formation/reorganization of adherens and tight junctions. Epithelial differentiation and augmented cell-cell contacts underlie the anti-migratory action exerted by the retinoid in cells exposed to the EMT-inducing factors EGF and heregulin-β1. Down-regulation of NOTCH1, an emerging EMT modulator, is involved in the inhibition of motility by ATRA. Indeed, the retinoid blocks NOTCH1 up-regulation by EGF and/or heregulin-β1. Pharmacological inhibition of γ-secretase and NOTCH1 processing also abrogates SKBR3 cell migration. Stimulation of TGFβ contributes to the anti-migratory effect of ATRA. The retinoid switches TGFβ from an EMT-inducing and pro-migratory determinant to an anti-migratory mediator. Inhibition of the NOTCH1 pathway not only plays a role in the anti-migratory action of ATRA; it is relevant also for the anti-proliferative activity of the retinoid in HCC1599 breast cancer cells, which are addicted to NOTCH1 for growth/viability. This effect is enhanced by the combination of ATRA and the γ-secretase inhibitor N-(N-(3,5-difluorophenacetyl)-l-alanyl)-S-phenylglycine t-butyl ester, supporting the concept that the two compounds act at the transcriptional and post-translational levels along the NOTCH1 pathway. PMID:26018078

  15. Retinoic Acid Attenuates Ileitis by Restoring the Balance between T-Helper 17 and T

    PubMed Central

    Collins, Colm B.; Aherne, Carol M.; Kominsky, Douglas; McNamee, Eóin N.; Lebsack, Matthew D.P.; Eltzschig, Holger; Jedlicka, Paul; Rivera-Nieves, Jesús

    2013-01-01

    Background & Aims Retinoic acid (RA), produced by intestinal epithelial cells (IECs) and dendritic cells (DCs) and regulated by transforming growth factor (TGF)-β, controls the enteric immune response by activating regulatory T (Treg) cells and preventing activation of T-helper (Th)17 cells Methods We studied the roles of RA in mice that overproduce tumor necrosis factor (TNF) and develop chronic ileitis (TNFΔARE mice). We assessed the frequency and function of CD103+ DCs and Th17 and Treg cells by flow cytometry; we measured expression of cytokines and retinaldehyde dehydrogenase (RALDH) enzymes in ileum samples, DCs, and IECs by real-time PCR. We quantified RA by electrochemical analysis and examined the effect of RA supplementation on TNF-induced ileitis using histologic, co-culture, and suppression assays and flow cytometry Results Numbers of CD103+ DCs decreased in the inflamed ilea of mice with chronic disease; RA synthetic machinery (RALDH1,2) was downregulated. Nevertheless, the proportion of CD4+, CD25+, FoxP3+ Treg cells increased, indicating an alternate source for RA. IECs responded to reduced levels of RA by upregulating RALDH3 in vivo and in vitro. Net tissue levels of RA levels remained lower in TNFΔARE than wild-type mice, indicating that epithelial up-regulation of RALDH3 could not maintain adequate concentrations of RA, probably because of loss of IEC mass. RA supplementation significantly attenuated disease by increasing the number and function of CD103+ DCs and Treg cells and reducing Th17 cells Conclusions Reduced levels of RA appear to induce IEC to upregulate synthesis of RA. RA supplementation attenuates ileitis through its effects on CD103+ DCs and Treg and Th17 cells. RA supplementation might used to treat patients with Crohn's disease PMID:22027263

  16. Caesium fluoride-promoted Stille coupling reaction: an efficient synthesis of 9Z-retinoic acid and its analogues using a practical building block.

    PubMed

    Okitsu, Takashi; Iwatsuka, Kinya; Wada, Akimori

    2008-12-21

    A highly efficient and rapid total synthesis of 9Z-retinoic acid was accomplished by caesium fluoride-promoted Stille coupling reaction; using a common building block, 9Z-retinoic acid analogues were also prepared by the same method without isomerisation of the Z-double bond.

  17. 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.

  18. 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

  19. Retinoic acid amplifies the host immune response to LPS through increased T lymphocytes number and LPS binding protein expression.

    PubMed

    Seguin-Devaux, Carole; Hanriot, Didier; Dailloux, Michèle; Latger-Cannard, Véronique; Zannad, Faiez; Mertes, Paul-Michel; Longrois, Dan; Devaux, Yvan

    2005-12-21

    Vitamin A deficiency is associated with increased susceptibility to infection but the effects of Vitamin A supplementation on host response to pathogens are controversial. This study investigated the mechanisms by which all-trans retinoic acid (atRA) modulates the host immune response in an experimental model of Vitamin A supplementation before and after challenge with LPS in rats. We show here that a supplementation with five daily injections of 10mg/kg atRA increased the number of T lymphocytes in the peripheral blood. In addition, we show that atRA increased the expression of the LPS binding protein (LBP), a component of the LPS recognition system. The retinoic acid receptor (RAR)alpha agonist Ro 4060-55 but not the pan-retinoid X receptors (RXRs) agonist Ro 2573-86 mimicked the effects of atRA on LBP expression suggesting that atRA enhances LBP expression through a RARalpha-mediated pathway. In order to investigate the significance of increased LBP expression we challenged atRA-supplemented rats with the Gram-positive bacteria Listeria monocytogenes (LM) that activates the immune response independently from LBP. In sharp contrast to our previous observations that atRA supplementation enhances IFN-gamma expression and NOS2 pathway activation in LPS-challenged rats [Devaux, Y., Grosjean, S., Seguin, C., David, C., Dousset, B., Zannad, F., Meistelman, C., de Talancé, N., Mertes, P.M., Ungureanu-Longrois, D., 2000. Retinoic acid and host-pathogen interactions: effects on inducible nitric oxide synthase in vivo. Am. J. Physiol. 279, E1045-E1053], atRA did not increase the LM-induced IFN-gamma expression and NOS2 pathway activation. Overall, these data demonstrate that although atRA induces a "priming" of the immune system characterized by increased T lymphocytes number and LBP expression, the profile of the immune response depends on the inflammatory/infectious stimulus. These results could explain why Vitamin A supplementation could have beneficial/neutral or

  20. Silybin from Silybum Marianum Seeds Inhibits Confluent-Induced Keratinocytes Differentiation as Effectively as Retinoic Acid without Inducing Inflammatory Cytokine.

    PubMed

    Kitajima, Seiji; Yamaguchi, Kohji

    2009-09-01

    Retinoic acid (RA) has been effective for improving wrinkles. However, it has also been reported that RA induces skin irritation. In this study, we explored new botanical compounds that show RA-like activity, but do not induce inflammation in vitro. Keratinocytes were maintained in a confluent condition and induced differentiation. Under this condition keratinocytes were treated with many botanical extracts and their morphological change were observed and compared with RA-treated. We found that silybin, which is a major flavonolignan from Silybum Marianum seeds, induced RA-like morphological change and prevented differentiation. We showed that silybin, like RA, reduced the expression of keratinocyte terminal differentiation markers and stimulated the expression of basement membrane component proteins. In contrast, silybin, unlike RA, did not stimulate the secretion of IL-1alpha, which is a skin irritation mediator. These results suggest that silybin has RA-like activity on keratinocytes and has the potential to improve winkle without inducing skin irritation.

  1. Ubiquitin specific protease 19 involved in transcriptional repression of retinoic acid receptor by stabilizing CORO2A

    PubMed Central

    Lim, Key-Hwan; Choi, Jong-Ho; Park, Jung-Hyun; Cho, Hyeon-Ju; Park, Jang-Joon; Lee, Eung-Ji; Li, Lan; Choi, Young-Kil; Baek, Kwang-Hyun

    2016-01-01

    Deubiquitination via deubiquitinating enzymes (DUBs) has been emerged as one of the important post-translational modifications, resulting in the regulation of numerous target proteins. In this study, we screened new protein biomarkers for adipogenesis, and related studies showed that ubiquitin specific protease 19 (USP19) as a DUB is gradually decreased during adipogenesis and it regulates coronin 2A (CORO2A) as one of the components for the nuclear receptor co-repressor (NCoR) complex in some studies. The regulation of CORO2A through the deubiquitinating activity of USP19 affected the transcriptional repression activity of the retinoic acid receptor (RAR), suggesting that USP19 may be involved in the regulation of RAR-mediated adipogenesis. PMID:27129179

  2. Detection of retinoic acid receptor antagonist contamination in the aquatic environment of the Kinki region of Japan.

    PubMed

    Inoue, Daisuke; Sawada, Kazuko; Sei, Kazunari; Ike, Michihiko

    2016-10-15

    Retinoic acid receptor (RAR) antagonists are potential toxic compounds that can cause teratogenesis in vertebrates. This study was conducted to evaluate the occurrence of RAR antagonist contamination in aquatic environments and identify its potential sources in detail. To accomplish this, the RAR antagonistic activities of surface waters of two rivers (the Yodo River and the Ina River) and influents and effluents of municipal wastewater treatment plants (WWTPs) in the Kinki region of Japan were investigated using a yeast two-hybrid assay. In the investigated rivers, remarkable RAR antagonistic activities were detected relatively consistently in specific regions, although the levels varied with time, and tended to increase downstream of municipal WWTPs. Investigations of WWTPs also revealed that RAR antagonists were present at remarkably high levels in municipal wastewater, and that RAR antagonist contamination remained in effluent after activated sludge treatments. Comparison of the concentration factors that reduced 50% of the RAR agonistic activity of 10(-7) M all-trans retinoic acid (IC50) for selected river water and WWTP effluent samples revealed that the contamination levels were greater in effluent (IC50: concentration factors of 92-313) than river water (IC50: concentration factors of 10.2-68.9). These results indicate that municipal WWTPs could be an important source of RAR antagonist contamination in the receiving rivers. Fractionations with high-performance liquid chromatography directed by the bioassay indicated that there were multiple RAR antagonists in municipal wastewater. Although a trial to identify the causative compounds in municipal wastewater was not completed, multiple bioactive peaks that should be studied further were isolated. This study clarified the occurrence of novel endocrine disrupting chemicals (i.e., RAR antagonists) in the aquatic environment at the watershed level and identified their possible source for the first time, which

  3. Detection of retinoic acid receptor antagonist contamination in the aquatic environment of the Kinki region of Japan.

    PubMed

    Inoue, Daisuke; Sawada, Kazuko; Sei, Kazunari; Ike, Michihiko

    2016-10-15

    Retinoic acid receptor (RAR) antagonists are potential toxic compounds that can cause teratogenesis in vertebrates. This study was conducted to evaluate the occurrence of RAR antagonist contamination in aquatic environments and identify its potential sources in detail. To accomplish this, the RAR antagonistic activities of surface waters of two rivers (the Yodo River and the Ina River) and influents and effluents of municipal wastewater treatment plants (WWTPs) in the Kinki region of Japan were investigated using a yeast two-hybrid assay. In the investigated rivers, remarkable RAR antagonistic activities were detected relatively consistently in specific regions, although the levels varied with time, and tended to increase downstream of municipal WWTPs. Investigations of WWTPs also revealed that RAR antagonists were present at remarkably high levels in municipal wastewater, and that RAR antagonist contamination remained in effluent after activated sludge treatments. Comparison of the concentration factors that reduced 50% of the RAR agonistic activity of 10(-7) M all-trans retinoic acid (IC50) for selected river water and WWTP effluent samples revealed that the contamination levels were greater in effluent (IC50: concentration factors of 92-313) than river water (IC50: concentration factors of 10.2-68.9). These results indicate that municipal WWTPs could be an important source of RAR antagonist contamination in the receiving rivers. Fractionations with high-performance liquid chromatography directed by the bioassay indicated that there were multiple RAR antagonists in municipal wastewater. Although a trial to identify the causative compounds in municipal wastewater was not completed, multiple bioactive peaks that should be studied further were isolated. This study clarified the occurrence of novel endocrine disrupting chemicals (i.e., RAR antagonists) in the aquatic environment at the watershed level and identified their possible source for the first time, which

  4. TRIM32 promotes retinoic acid receptor {alpha}-mediated differentiation in human promyelogenous leukemic cell line HL60

    SciTech Connect

    Sato, Tomonobu; Okumura, Fumihiko; Iguchi, Akihiro; Ariga, Tadashi; Hatakeyama, Shigetsugu

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer TRIM32 enhanced RAR{alpha}-mediated transcriptional activity even in the absence of RA. Black-Right-Pointing-Pointer TRIM32 stabilized RAR{alpha} in the human promyelogenous leukemic cell line HL60. Black-Right-Pointing-Pointer Overexpression of TRIM32 in HL60 cells induced granulocytic differentiation. Black-Right-Pointing-Pointer TRIM32 may function as a coactivator for RAR{alpha}-mediated transcription in APL cells. -- Abstract: Ubiquitination, one of the posttranslational modifications, appears to be involved in the transcriptional activity of nuclear receptors including retinoic acid receptor {alpha} (RAR{alpha}). We previously reported that an E3 ubiquitin ligase, TRIM32, interacts with several important proteins including RAR{alpha} and enhances transcriptional activity of RAR{alpha} in mouse neuroblastoma cells and embryonal carcinoma cells. Retinoic acid (RA), which acts as a ligand to nuclear receptors including RAR{alpha}, plays crucial roles in development, differentiation, cell cycles and apoptosis. In this study, we found that TRIM32 enhances RAR{alpha}-mediated transcriptional activity even in the absence of RA and stabilizes RAR{alpha} in the human promyelogenous leukemic cell line HL60. Moreover, we found that overexpression of TRIM32 in HL60 cells suppresses cellular proliferation and induces granulocytic differentiation even in the absence of RA. These findings suggest that TRIM32 functions as one of the coactivators for RAR{alpha}-mediated transcription in acute promyelogenous leukemia (APL) cells, and thus TRIM32 may become a potentially therapeutic target for APL.

  5. Locust retinoid X receptors: 9-Cis-retinoic acid in embryos from a primitive insect.

    PubMed

    Nowickyj, Shaun M; Chithalen, James V; Cameron, Don; Tyshenko, Michael G; Petkovich, Martin; Wyatt, Gerard R; Jones, Glenville; Walker, Virginia K

    2008-07-15

    The retinoid X receptor (RXR) is activated by its often elusive cognate ligand, 9-cis-retinoic acid (9-cis-RA). In flies and moths, molting is mediated by a heterodimer ecdysone receptor consisting of the ecdysone monomer (EcR) and an RXR homolog, ultraspiracle (USP); the latter is believed to have diverged from its RXR origin. In the more primitive insect, Locusta migratoria (Lm), RXR is more similar to human RXRs than to USPs. LmRXR was detected in early embryos when EcR transcripts were absent, suggesting another role apart from ecdysone signaling. Recombinant LmRXRs bound 9-cis-RA and all-trans-RA with high affinity (IC(50) = 61.2-107.7 nM; K(d) = 3 nM), similar to human RXR. To determine whether specific binding had functional significance, the presence of endogenous retinoids was assessed. Embryos were extracted by using modified Bligh and Dyer and solid-phase protocols to avoid the oily precipitate that makes this material unsuitable for assay. These extracts contained retinoids (5.4 nM) as assessed by RA-inducible Cyp26A1-promoter luciferase reporter cell lines. Furthermore, the use of HPLC and MS confirmed the presence of retinoids and identified in any embryo, 9-cis-RA, in addition to all-trans-RA. We estimate that whole embryos contain 3 nM RA, including 9-cis-RA at a concentration of 1.6 nM. These findings strongly argue for a functional role for retinoids in primitive insects and favor a model where signaling through the binding of 9-cis-RA to its RXR is established relatively early in evolution and embryonic development.

  6. Selective agonists of retinoic acid receptors: comparative toxicokinetics and embryonic exposure.

    PubMed

    Arafa, H M; Elmazar, M M; Hamada, F M; Reichert, U; Shroot, B; Nau, H

    2000-01-01

    Three biologically active synthetic retinoids were investigated that bind selectively to retinoic acid receptors RARs (alpha, beta and gamma). The retinoids were previously demonstrated to have different teratogenic effects in the mouse in terms of potency and regioselectivity. The teratogenic potency rank order (alpha >beta >gamma) was found to be more or less compatible with the receptor binding affinities and transactivation potencies of the retinoid ligands to their respective receptors. The RARalpha agonist (Am580; CD336) induced a wide spectrum of malformations; CD2019 (RARbeta agonist) and especially CD437 (RARgamma agonist) produced more restricted defects. In the current study we tried to address whether the differences in teratogenic effects are solely related to binding affinity and transactivation differences or also due to differences in embryonic exposure. Therefore, transplacental kinetics of the ligands were assessed following administration of a single oral dose of 15 mg/kg of either retinoid given to NMRI mice on day 11 of gestation. Am580 was rapidly transferred to the embryo resulting in the highest embryonic exposure [embryo to maternal plasma area under the time vs concentration curve (AUC)(0-24 h )ratio (E/M) was 1.7], in accordance with its highest teratogenic potency. The low placental transfer of CD2019 (E/M of 0.3) was compatible with its lower teratogenic potential. Of major interest was the finding that the CD437, though being least teratogenic, exhibited considerable embryonic exposure (E/M of 0.6). These findings suggest that both the embryonic exposure and receptor binding transactivation selectivity are crucial determinants of the teratogenicity of these retinoid ligands.

  7. Pharmacologic retinoid signaling and physiologic retinoic acid receptor signaling inhibit basal cell carcinoma tumorigenesis.

    PubMed

    So, Po-Lin; Fujimoto, Michele A; Epstein, Ervin H

    2008-05-01

    Basal cell carcinoma (BCC) is the most common human cancer. Patients with basal cell nevus syndrome (Gorlin syndrome) are highly susceptible to developing many BCCs as a result of a constitutive inactivating mutation in one allele of PATCHED 1, which encodes a tumor suppressor that is a major inhibitor of Hedgehog signaling. Dysregulated Hedgehog signaling is a common feature of both hereditary and sporadic BCCs. Recently, we showed remarkable anti-BCC chemopreventive efficacy of tazarotene, a retinoid with retinoic acid receptor (RAR) beta/gamma specificity, in Ptch1+/- mice when treatment was commenced before carcinogenic insults. In this study, we assessed whether the effect of tazarotene against BCC carcinogenesis is sustained after its withdrawal and whether tazarotene is effective against preexisting microscopic BCC lesions. We found that BCCs did not reappear for at least 5 months after topical drug treatment was stopped and that already developed, microscopic BCCs were susceptible to tazarotene inhibition. In vitro, tazarotene inhibited a murine BCC keratinocyte cell line, ASZ001, suggesting that its effect in vivo is by direct action on the actual tumor cells. Down-regulation of Gli1, a target gene of Hedgehog signaling and up-regulation of CRABPII, a target gene of retinoid signaling, were observed with tazarotene treatment. Finally, we investigated the effects of topical applications of other retinoid-related compounds on BCC tumorigenesis in vivo. Tazarotene was the most effective of the preparations studied, and its effect most likely was mediated by RARgamma activation. Furthermore, inhibition of basal RAR signaling in the skin promoted BCC carcinogenesis, suggesting that endogenous RAR signaling restrains BCC growth.

  8. Retinoic acid-induced expression of apolipoprotein D and concomitant growth arrest in human breast cancer cells are mediated through a retinoic acid receptor RARalpha-dependent signaling pathway.

    PubMed

    López-Boado, Y S; Klaus, M; Dawson, M I; López-Otín, C

    1996-12-13

    Apolipoprotein D (apoD) is a human plasma protein, belonging to the lipocalin superfamily, that is produced by a specific subtype of highly differentiated breast carcinomas and that is strongly up-regulated by retinoic acid (RA) in breast cancer cells. In this work, we have examined the molecular mechanisms mediating the induction of apoD gene expression by retinoids in T-47D human breast cancer cells. Northern blot analysis revealed that Ro40-6055, a synthetic retinoid that selectively binds and activates the retinoic acid receptor RARalpha, induced the accumulation of apoD mRNA in breast cancer cells in a time- and dose-dependent manner. The time course analysis demonstrated that apoD mRNA was induced 14-fold over control cells after 48 h of incubation with 10(-8) M Ro40-6055. As little as 10(-11) M of this retinoid induced apoD mRNA 5-fold over the control, whereas incubation with 10(-7) M Ro40-6055 induced maximally 15-fold over control cells. RARalpha-selective antagonists counteracted the inductive effects of all-trans-RA, 9-cis-RA, and Ro40-6055 on the expression of apoD, when present at the same concentration as the retinoid agonists. By contrast, RARbeta-, RARgamma-, and RXR-selective retinoids did not affect apoD gene expression. The retinoid agonist Ro40-6055 had an antiproliferative effect on T-47D cells, with maximal growth inhibition of approximately 60% obtained after 7 days of incubation with 10(-7) M. This antiproliferative effect could be counteracted by a 100-fold excess of the antagonist Ro41-5253. Treatment of the cells with retinoids that do not bind the nuclear retinoic acid receptors did not affect apoD expression, despite the fact that they did have a strong antiproliferative effect on T-47D cells. On the basis of these results, a role for RARalpha on apoD gene expression induction by retinoids in breast cancer cells is proposed.

  9. Impaired Development of Left Anterior Heart Field by Ectopic Retinoic Acid Causes Transposition of the Great Arteries

    PubMed Central

    Narematsu, Mayu; Kamimura, Tatsuya; Yamagishi, Toshiyuki; Fukui, Mitsuru; Nakajima, Yuji

    2015-01-01

    Background Transposition of the great arteries is one of the most commonly diagnosed conotruncal heart defects at birth, but its etiology is largely unknown. The anterior heart field (AHF) that resides in the anterior pharyngeal arches contributes to conotruncal development, during which heart progenitors that originated from the left and right AHF migrate to form distinct conotruncal regions. The aim of this study is to identify abnormal AHF development that causes the morphology of transposition of the great arteries. Methods and Results We placed a retinoic acid–soaked bead on the left or the right or on both sides of the AHF of stage 12 to 14 chick embryos and examined the conotruncal heart defect at stage 34. Transposition of the great arteries was diagnosed at high incidence in embryos for which a retinoic acid–soaked bead had been placed in the left AHF at stage 12. Fluorescent dye tracing showed that AHF exposed to retinoic acid failed to contribute to conotruncus development. FGF8 and Isl1 expression were downregulated in retinoic acid–exposed AHF, and differentiation and expansion of cardiomyocytes were suppressed in cultured AHF in medium supplemented with retinoic acid. Conclusions The left AHF at the early looped heart stage, corresponding to Carnegie stages 10 to 11 (28 to 29 days after fertilization) in human embryos, is the region of the impediment that causes the morphology of transposition of the great arteries. PMID:25929268

  10. 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

  11. Regulation of vitamin D receptor expression by retinoic acid receptor alpha in acute myeloid leukemia cells.

    PubMed

    Marchwicka, Aleksandra; Cebrat, Małgorzata; Łaszkiewicz, Agnieszka; Śnieżewski, Łukasz; Brown, Geoffrey; Marcinkowska, Ewa

    2016-05-01

    Acute myeloid leukemia (AML) is the predominant acute leukemia among adults, characterized by an accumulation of malignant immature myeloid precursors. A very promising way to treat AML is differentiation therapy using either all-trans-retinoic acid (ATRA) or 1,25-dihydroxyvitamin D3 (1,25D), or the use of both these differentiation-inducing agents. However, the effect of combination treatment varies in different AML cell lines, and this is due to ATRA either down- or up-regulating transcription of vitamin D receptor (VDR) in the cells examined. The mechanism of transcriptional regulation of VDR in response to ATRA has not been fully elucidated. Here, we show that the retinoic acid receptor α (RARα) is responsible for regulating VDR transcription in AML cells. We have shown that a VDR transcriptional variant, originating in exon 1a, is regulated by RARα agonists in AML cells. Moreover, in cells with a high basal level of RARα protein, the VDR gene is transcriptionally repressed as long as RARα agonist is absent. In these cells down-regulation of the level of RARα leads to increased expression of VDR. We consider that our findings provide a mechanistic background to explain the different outcomes from treating AML cell lines with a combination of ATRA and 1,25D. PMID:26969398

  12. MicroRNA 146 (Mir146) modulates spermatogonial differentiation by retinoic acid in mice.

    PubMed

    Huszar, Jessica M; Payne, Christopher J

    2013-01-01

    Impaired biogenesis of microRNAs disrupts spermatogenesis and leads to infertility in male mice. Spermatogonial differentiation is a key step in spermatogenesis, yet the mechanisms that control this event remain poorly defined. In this study, we discovered microRNA 146 (Mir146) to be highly regulated during spermatogonial differentiation, a process dependent on retinoic acid (RA) signaling. Mir146 transcript levels were diminished nearly 180-fold in differentiating spermatogonia when compared with undifferentiated spermatogonia. Luciferase assays revealed the direct binding of Mir146 to the 3' untranslated region of the mediator complex subunit 1 (Med1), a coregulator of retinoid receptors (RARs and RXRs). Overexpression of Mir146 in cultured undifferentiated spermatogonia reduced Med1 transcript levels, as well as those of differentiation marker kit oncogene (Kit). MED1 protein was also diminished. Conversely, inhibition of Mir146 increased the levels of Kit. When undifferentiated spermatogonia were exposed to RA, Mir146 was downregulated along with a marker for undifferentiated germ cells, zinc finger and BTB domain containing 16 (Zbtb16; Plzf); Kit was upregulated. Overexpression of Mir146 in RA-treated spermatogonia inhibited the upregulation of Kit, stimulated by retinoic acid gene 8 (Stra8), and spermatogenesis- and oogenesis-specific basic helix-loop-helix 2 (Sohlh2). Inhibition of Mir146 in RA-treated spermatogonia greatly enhanced the upregulation of these genes. We conclude that Mir146 modulates the effects of RA on spermatogonial differentiation.

  13. MicroRNA 146 (Mir146) Modulates Spermatogonial Differentiation by Retinoic Acid in Mice1

    PubMed Central

    Huszar, Jessica M.; Payne, Christopher J.

    2012-01-01

    ABSTRACT Impaired biogenesis of microRNAs disrupts spermatogenesis and leads to infertility in male mice. Spermatogonial differentiation is a key step in spermatogenesis, yet the mechanisms that control this event remain poorly defined. In this study, we discovered microRNA 146 (Mir146) to be highly regulated during spermatogonial differentiation, a process dependent on retinoic acid (RA) signaling. Mir146 transcript levels were diminished nearly 180-fold in differentiating spermatogonia when compared with undifferentiated spermatogonia. Luciferase assays revealed the direct binding of Mir146 to the 3′ untranslated region of the mediator complex subunit 1 (Med1), a coregulator of retinoid receptors (RARs and RXRs). Overexpression of Mir146 in cultured undifferentiated spermatogonia reduced Med1 transcript levels, as well as those of differentiation marker kit oncogene (Kit). MED1 protein was also diminished. Conversely, inhibition of Mir146 increased the levels of Kit. When undifferentiated spermatogonia were exposed to RA, Mir146 was downregulated along with a marker for undifferentiated germ cells, zinc finger and BTB domain containing 16 (Zbtb16; Plzf); Kit was upregulated. Overexpression of Mir146 in RA-treated spermatogonia inhibited the upregulation of Kit, stimulated by retinoic acid gene 8 (Stra8), and spermatogenesis- and oogenesis-specific basic helix-loop-helix 2 (Sohlh2). Inhibition of Mir146 in RA-treated spermatogonia greatly enhanced the upregulation of these genes. We conclude that Mir146 modulates the effects of RA on spermatogonial differentiation. PMID:23221399

  14. Retinol kinetics in unsupplemented and vitamin A-retinoic acid supplemented neonatal rats: a preliminary model

    PubMed Central

    Tan, Libo; Wray, Amanda E.; Green, Michael H.; Ross, A. Catharine

    2014-01-01

    Vitamin A (VA) metabolism in neonates is virtually uncharacterized. Our objective was to develop a compartmental model of VA metabolism in unsupplemented and VA-supplemented neonatal rats. On postnatal day 4, pups (n = 3/time) received 11,12-[3H]retinol orally, in either oil (control) or VA combined with retinoic acid (VARA) [VA (∼6 mg/kg body weight) + 10% retinoic acid]. Plasma and tissues were collected at 14 time points up to 14 days after dose administration. VARA supplementation rapidly, but transiently, increased total retinol mass in plasma, liver, and lung. It decreased the peak fraction of the dose in plasma. A multi-compartmental model developed to fit plasma [3H]retinol data predicted more extensive recycling of retinol between plasma and tissues in neonates compared with that reported in adults (144 vs. 12–13 times). In VARA pups, the recycling number for retinol between plasma and tissues (100 times) and the time that retinol spent in plasma were both lower compared with controls; VARA also stimulated the uptake of plasma VA into extravascular tissues. A VARA perturbation model indicated that the effect of VARA in stimulating VA uptake into tissues in neonates is both dramatic and transient. PMID:24711633

  15. Processive Pulses of Retinoic Acid Propel Asynchronous and Continuous Murine Sperm Production1

    PubMed Central

    Hogarth, Cathryn A.; Arnold, Samuel; Kent, Travis; Mitchell, Debra; Isoherranen, Nina; Griswold, Michael D.

    2014-01-01

    ABSTRACT The asynchronous cyclic nature of spermatogenesis is essential for continual sperm production and is one of the hallmarks of mammalian male fertility. While various mRNA and protein localization studies have indirectly implicated changing retinoid levels along testis tubules, no quantitative evidence for these changes across the cycle of the seminiferous epithelium currently exists. This study utilized a unique mouse model of induced synchronous spermatogenesis, localization of the retinoid-signaling marker STRA8, and sensitive quantification of retinoic acid concentrations to determine whether there are fluctuations in retinoid levels at each of the individual stages of germ cell differentiation and maturation to sperm. These data show that processive pulses of retinoic acid are generated during spermatogonial differentiation and are the likely trigger for cyclic spermatogenesis and allow us, for the first time, to understand how the cycle of the seminiferous epithelium is generated and maintained. In addition, this study represents the first direct quantification of a retinoid gradient controlling cellular differentiation in a postnatal tissue. PMID:25519186

  16. Signaling through retinoic acid receptors in cardiac development: Doing the right things at the right times.

    PubMed

    Xavier-Neto, José; Sousa Costa, Ângela M; Figueira, Ana Carolina M; Caiaffa, Carlo Donato; Amaral, Fabio Neves do; Peres, Lara Maldanis Cerqueira; da Silva, Bárbara Santos Pires; Santos, Luana Nunes; Moise, Alexander R; Castillo, Hozana Andrade

    2015-02-01

    Retinoic acid (RA) is a terpenoid that is synthesized from vitamin A/retinol (ROL) and binds to the nuclear receptors retinoic acid receptor (RAR)/retinoid X receptor (RXR) to control multiple developmental processes in vertebrates. The available clinical and experimental data provide uncontested evidence for the pleiotropic roles of RA signaling in development of multiple embryonic structures and organs such eyes, central nervous system, gonads, lungs and heart. The development of any of these above-mentioned embryonic organ systems can be effectively utilized to showcase the many strategies utilized by RA signaling. However, it is very likely that the strategies employed to transfer RA signals during cardiac development comprise the majority of the relevant and sophisticated ways through which retinoid signals can be conveyed in a complex biological system. Here, we provide the reader with arguments indicating that RA signaling is exquisitely regulated according to specific phases of cardiac development and that RA signaling itself is one of the major regulators of the timing of cardiac morphogenesis and differentiation. We will focus on the role of signaling by RA receptors (RARs) in early phases of heart development. This article is part of a Special Issue entitled: Nuclear receptors in animal development.

  17. Embryonic Gut Anomalies in a Mouse Model of Retinoic Acid-Induced Caudal Regression Syndrome

    PubMed Central

    Pitera, Jolanta E.; Smith, Virpi V.; Woolf, Adrian S.; Milla, Peter J.

    2001-01-01

    Vitamin A and its derivatives such as retinoic acid (RA) are important signaling molecules for morphogenesis of vertebrate embryos. Little is known, however, about morphogenetic factors controlling the development of the gastrointestinal tract and RA is likely to be involved. In the mouse, teratogenic doses of RA cause truncation of the embryonic caudal body axis that parallel the caudal regression syndrome as described in humans. These changes are often associated with anomalies of the lower digestive tract. Overlapping spatiotemporal expression of retinoic acid receptor-β (RARβ) and cellular retinol-binding protein I, CRBPI, with Hoxb5 and c-ret in the gut mesoderm imply possible cooperation required for proper neuromuscular development. To determine susceptibility and responsiveness of the developing gut and its neuromusculature to exogenous retinoids we used a mouse model of RA-induced caudal regression syndrome. The results showed that stage-specific RA treatment both in vivo and in vitro affected gut looping/rotation morphogenesis and growth of asymmetrical structures such as the cecum together with delayed differentiation of the gut mesoderm and colonization of the postcecal gut by neural crest-derived enteric neuronal precursors. These observations demonstrate that RA has a direct effect on gut morphogenesis and innervation. PMID:11733381

  18. Processive pulses of retinoic acid propel asynchronous and continuous murine sperm production.

    PubMed

    Hogarth, Cathryn A; Arnold, Samuel; Kent, Travis; Mitchell, Debra; Isoherranen, Nina; Griswold, Michael D

    2015-02-01

    The asynchronous cyclic nature of spermatogenesis is essential for continual sperm production and is one of the hallmarks of mammalian male fertility. While various mRNA and protein localization studies have indirectly implicated changing retinoid levels along testis tubules, no quantitative evidence for these changes across the cycle of the seminiferous epithelium currently exists. This study utilized a unique mouse model of induced synchronous spermatogenesis, localization of the retinoid-signaling marker STRA8, and sensitive quantification of retinoic acid concentrations to determine whether there are fluctuations in retinoid levels at each of the individual stages of germ cell differentiation and maturation to sperm. These data show that processive pulses of retinoic acid are generated during spermatogonial differentiation and are the likely trigger for cyclic spermatogenesis and allow us, for the first time, to understand how the cycle of the seminiferous epithelium is generated and maintained. In addition, this study represents the first direct quantification of a retinoid gradient controlling cellular differentiation in a postnatal tissue.

  19. 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

  20. SIGNALLING THROUGH RETINOIC ACID RECEPTORS IN CARDIAC DEVELOPMENT: DOING THE RIGHT THINGS AT THE RIGHT TIMES

    PubMed Central

    Xavier-Neto, José; Costa, Ângela M. Sousa; Figueira, Ana Carolina M.; Caiaffa, Carlo Donato; do Amaral, Fabio Neves; Peres, Lara Maldanis Cerqueira; da Silva, Bárbara Santos Pires; Santos, Luana Nunes; Moise, Alexander R.; Castillo, Hozana Andrade

    2015-01-01

    Retinoic acid (RA) is a terpenoid that is synthesized from Vitamin A/retinol (ROL) and binds to the nuclear receptors retinoic acid receptor (RAR)/retinoid X receptor (RXR) to control multiple developmental processes in vertebrates. The available clinic and experimental data provide uncontested evidence for the pleiotropic roles of RA signalling in development of multiple embryonic structures and organs such eyes, central nervous system, gonads, lungs and heart. The development of any of these above-mentioned embryonic organ systems can be effectively utilized to showcase the many strategies utilized by RA signalling. However, it is very likely that the strategies employed to transfer RA signals during cardiac development comprise the majority of the relevant and sophisticated ways through which retinoid signals can be conveyed in a complex biological system. Here, we provide the reader with arguments indicating that RA signalling is exquisitely regulated according to specific phases of cardiac development and that RA signalling itself is one of the major regulators of the timing of cardiac morphogenesis and differentiation. We will focus on the role of signalling by RA receptors (RARs) in early phases of heart development. PMID:25134739

  1. Selective Retinoic Acid Receptor γ Agonists Promote Repair of Injured Skeletal Muscle in Mouse

    PubMed Central

    Di Rocco, Agnese; Uchibe, Kenta; Larmour, Colleen; Berger, Rebecca; Liu, Min; Barton, Elisabeth R.; Iwamoto, Masahiro

    2016-01-01

    Retinoic acid signaling regulates several biological events, including myogenesis. We previously found that retinoic acid receptor γ (RARγ) agonist blocks heterotopic ossification, a pathological bone formation that mostly occurs in the skeletal muscle. Interestingly, RARγ agonist also weakened deterioration of muscle architecture adjacent to the heterotopic ossification lesion, suggesting that RARγ agonist may oppose skeletal muscle damage. To test this hypothesis, we generated a critical defect in the tibialis anterior muscle of 7-week-old mice with a cautery, treated them with RARγ agonist or vehicle corn oil, and examined the effects of RARγ agonist on muscle repair. The muscle defects were partially repaired with newly regenerating muscle cells, but also filled with adipose and fibrous scar tissue in both RARγ-treated and control groups. The fibrous or adipose area was smaller in RARγ agonist–treated mice than in the control. In addition, muscle repair was remarkably delayed in RARγ-null mice in both critical defect and cardiotoxin injury models. Furthermore, we found a rapid increase in retinoid signaling in lacerated muscle, as monitored by retinoid signaling reporter mice. Together, our results indicate that endogenous RARγ signaling is involved in muscle repair and that selective RARγ agonists may be beneficial to promote repair in various types of muscle injuries. PMID:26205250

  2. Effects of retinoic acid receptor-selective agonists on human nasal epithelial cell differentiation.

    PubMed

    Million, K; Tournier, F; Houcine, O; Ancian, P; Reichert, U; Marano, F

    2001-12-01

    Retinoids play a critical role in the maintenance of the mucociliary phenotype of epithelial cells in the upper respiratory tract. To determine the role of retinoic acid receptors (RARs) in the regulation of epithelial differentiation, we tested the effect of the synthetic retinoids CD336, CD2019, and CD666, selective agonists for RARalpha, RARbeta, and RARgamma, respectively, during differentiation of human nasal epithelial (HNE) cells in vitro. Using glutamylated tubulin and transglutaminase I (Tg I) as markers of ciliated cell and squamous cell differentiation, respectively, we showed that retinoic acid (RA) stimulated mucociliary differentiation and, in parallel, inhibited squamous cell differentiation. The agonists of the three RARs independently induced ciliogenesis and inhibited squamous cell differentiation by downregulating Tg I expression in a dose- and time-dependent manner. Antagonists specific for the three RARs abolished the effects of the corresponding agonists, demonstrating an RAR-specific mediated effect. Moreover, treatment of retinoid-deficient cultures with RAR agonists induced conversion of the squamous-like phenotype into a ciliated phenotype. In conclusion, all three RARs are potentially involved in the differentiating effects of RA in respiratory epithelial cells.

  3. Retinoic acid and mouse skin morphogenesis. II. Role of epidermal competence in hair glandular metaplasia.

    PubMed

    Viallet, J P; Dhouailly, D

    1994-11-01

    Retinoic acid (RA) has marked effects on mouse upper-lip skin morphogenesis, leading to the development of glomerular gland instead of hair vibrissa follicle, but does not apparently change the dorsal pelage hair developmental program. In order to test the hypothesis that an up-regulation of the beta retinoic acid nuclear receptor (RAR beta) may be implicated in the alteration of the dermal-epidermal interactions which occur during cutaneous appendage development, RA-treated and untreated skin explants, controls as well as heterotopic recombinants, were made among nasal, upper-lip, and dorsal mouse embryonic tissues. They were analyzed by in situ hybridization with RAR beta 35S-labeled probe after 48 hr of in vitro culture as well as by identification of the morphological phenotype of cutaneous appendages after 6 additional days of culture on the chick chorioallantoic membrane. The results show that only mesenchyme from the facial region can express the RAR beta gene either normally or after RA treatment, depending on its nasal or upper-lip origin. However, the RAR beta up-regulation is unrelated to hair glandular metaplasia, which depends both on a glandular bias of the upper-lip epidermis and on the weakening of hair follicle-inducing dermal properties. The latter occurs in both the upper-lip and dorsal dermis as a consequence of RA treatment.

  4. Impact of preconditioning with retinoic acid during early development on morphological and functional characteristics of human induced pluripotent stem cell-derived neurons.

    PubMed

    Horschitz, Sandra; Matthäus, Friederike; Groß, Anja; Rosner, Jan; Galach, Marta; Greffrath, Wolfgang; Treede, Rolf-Detlef; Utikal, Jochen; Schloss, Patrick; Meyer-Lindenberg, Andreas

    2015-07-01

    Human induced pluripotent stem cells (hiPSCs) are a suitable tool to study basic molecular and cellular mechanisms of neurodevelopment. The directed differentiation of hiPSCs via the generation of a self-renewable neuronal precursor cell line allows the standardization of defined differentiation protocols. Here, we have investigated whether preconditioning with retinoic acid during early neural induction impacts on morphological and functional characteristics of the neuronal culture after terminal differentiation. For this purpose we have analyzed neuronal and glial cell markers, neuronal outgrowth, soma size, depolarization-induced distal shifts of the axon initial segment as well as glutamate-evoked calcium influx. Retinoic acid preconditioning led to a higher yield of neurons vs. glia cells and longer axons than unconditioned controls. In contrast, glutamatergic activation and depolarization induced structural plasticity were unchanged. Our results show that the treatment of neuroectodermal cells with retinoic acid during early development, i.e. during the neurulation phase, increases the yield of neuronal phenotypes, but does not impact on the functionality of terminally differentiated neuronal cells. PMID:26001168

  5. BCOR as a novel fusion partner of retinoic acid receptor alpha in a t(X;17)(p11;q12) variant of acute promyelocytic leukemia.

    PubMed

    Yamamoto, Yukiya; Tsuzuki, Sachiko; Tsuzuki, Motohiro; Handa, Kousuke; Inaguma, Yoko; Emi, Nobuhiko

    2010-11-18

    The majority of acute promyelocytic leukemia (APL) cases are characterized by the presence of a promyelocytic leukemia-retinoic acid receptor alpha(RARA) fusion gene. In a small subset, RARA is fused to a different partner, usually involved in regulating cell growth and differentiation. Here, we identified a novel RARA fusion transcript, BCOR-RARA, in a t(X;17)(p11;q12) variant of APL with unique morphologic features, including rectangular and round cytoplasmic inclusion bodies. Although the patient was clinically responsive to all-trans retinoic acid, several relapses occurred with standard chemotherapy and all-trans retinoic acid. BCOR is a transcriptional corepressor through the proto-oncoprotein, BCL6, recruiting histone deacetylases and polycomb repressive complex 1 components. BCOR-RARA was found to possess common features with other RARA fusion proteins. These included: (1) the same break point in RARA cDNA; (2) self-association; (3) retinoid X receptor alpha is necessary for BCOR-RARA to associate with the RARA responsive element; (4) action in a dominant-negative manner on RARA transcriptional activation; and (5) aberrant subcellular relocalization. It should be noted that there was no intact BCOR found in the 45,-Y,t(X;17)(p11;q12) APL cells because they featured only a rearranged X chromosome. These results highlight essential features of pathogenesis in APL in more detail. BCOR appears to be involved not only in human congenital diseases, but also in a human cancer. PMID:20807888

  6. Zebrafish nephrogenesis involves dynamic spatiotemporal expression changes in renal progenitors and essential signals from retinoic acid and irx3b

    PubMed Central

    Wingert, Rebecca A.; Davidson, Alan J.

    2013-01-01

    Kidney nephrons are comprised of proximal and distal tubule segments that perform unique roles in excretion. The developmental pathways that establish nephron segment identities from renal progenitors are poorly understood. Here, we used the zebrafish pronephros to study nephron segmentation. We found that zebrafish nephron progenitors undergo elaborate spatiotemporal expression changes of many genes before adopting a segment fate. Initially, two domains of nephron progenitors are established, then are subdivided and demarcate individual nephron segments. Using genetic and chemical genetic models of retinoic acid (RA) deficiency, we discovered that RA modulates rostral progenitor formation. To delineate downstream pathways, we knocked down the irx3b transcription factor and found it regulates proximal tubule segment size and distal segment differentiation. Our results suggest a model whereby RA patterns the early field of nephron progenitors, with subsequent factors like irx3b acting to refine later progenitor subdomains and ensure activation of segment-specific gene programs. PMID:21761484

  7. Nicotinamide attenuates aquaporin 3 overexpression induced by retinoic acid through inhibition of EGFR/ERK in cultured human skin keratinocytes.

    PubMed

    Song, Xiuzu; Xu, Aie; Pan, Wei; Wallin, Brittany; Kivlin, Rebecca; Lu, Shan; Cao, Cong; Bi, Zhigang; Wan, Yinsheng

    2008-08-01

    The most common adverse effects that are related to all-trans retinoic acid (atRA) treatment are irritation and dryness of the skin. atRA therapy is reported to impair barrier function as achieved by trans-epidermal water loss (TEWL). Treatment with nicotinamide prior to initiation of atRA therapy provides additional barrier protection and thus reduces susceptibility of retinoic acid. Our previous studies showed that atRA upregulates aquaporin 3 (AQP3) in cultured human skin keratinocytes and fibroblasts. Others have demonstrated that in atopic dermatitis, overexpression of AQP3 is linked to elevated TEWL and that nicotinamide treatment reduces skin TEWL. In this study, we observed that while atRA upregulates AQP3 expression in cultured human skin keratinocytes (HaCaT cells), nicotinamide attenuates the effect of atRA in a concentration-dependent manner. atRA treatment induces EGFR and ERK activation. PD153035, an EGFR inhibitor, and U0126, an ERK inhibitor, inhibit atRA-induced upregulation of AQP3. Nicotinamide also inhibits atRA-induced activation of EGFR/ERK signal transduction and decreases water permeability by downregulating AQP3 expression. Collectively, our results indicate that the effect of atRA on AQP3 expression is at least partly mediated by EGFR/ERK signaling in cultured human skin keratinocytes. Nicotinamide attenuates atRA-induced AQP3 expression through inhibition of EGFR/ERK signal transduction and eventually decreases water permeability and water loss. Our study provides insights into the molecular mechanism through which nicotinamide reverses the side effects of dryness in human skin after treatment with atRA.

  8. Downregulation of angiotensin II type 1 receptor by all-trans retinoic acid in vascular smooth muscle cells.

    PubMed

    Takeda, K; Ichiki, T; Funakoshi, Y; Ito, K; Takeshita, A

    2000-01-01

    All-trans retinoic acid (atRA) is a biologically active metabolite of vitamin A that plays an important role in cell differentiation and proliferation. Although neointimal formation after balloon injury of rat carotid artery is inhibited by atRA, the mechanisms are not clearly understood. Because the renin-angiotensin system is one of the crucial components of atherosclerosis, we examined the effects of atRA on the expression of angiotensin II type 1 receptor (AT(1)-R) in vascular smooth muscle cells. atRA (1 micromol/L) decreased the AT(1)-R mRNA level by 50% after 24 hours; AT(1)-R number was also reduced to the same extent after 48 hours. atRA markedly suppressed promoter activity of the AT(1)-R promoter-luciferase construct, but AT(1)-R mRNA stability was not affected. Cycloheximide blocked the atRA-induced decrease in AT(1)-R mRNA expression, suggesting that this process requires de novo protein synthesis. Simultaneous treatment with an agonist (Ro40-6055) specific for retinoic acid receptor (RAR) and an agonist (Ro25-7836) specific for retinoid X receptor (RXR) suppressed the AT(1)-R mRNA expression comparable to that with treatment with atRA, suggesting that the RAR/RXR heterodimer mediates the effect of atRA in AT(1)-R downregulation. These results suggest that atRA suppressed AT(1)-R mRNA transcription through new protein synthesis induced by RAR/RXR-dependent transcription. This study provides novel insight into a role of atRA as an important molecule that regulates AT(1)-R gene expression and provides possible mechanisms for the suppression of neointimal formation by atRA.

  9. Retinoic acid is required for specification of the ventral eye field and for Rathke's pouch in the avian embryo.

    PubMed

    Maden, Malcolm; Blentic, Aida; Reijntjes, Susan; Seguin, Sophie; Gale, Emily; Graham, Anthony

    2007-01-01

    We have investigated the role of retinoic acid (RA) in eye development using the vitamin A deficient quail model system, which overcomes problems of retinoic acid synthesising enzyme redundancy in the embryo. In the absence of retinoic acid, the ventral optic stalk and ventral retina are missing, whereas the dorsal optic stalk and dorsal retina develop appropriately. Other ocular abnormalities observed were a thinner retina and the lack of differentiation of the lens. In an attempt to explain this, we studied the expression of various dorsally and ventrally expressed genes such as Pax2, Pax6, Tbx6, Vax2, Raldh1 and Raldh3 and noted that they were unchanged in their expression patterns. In contrast, the RA catabolising enzymes Cyp26A1 and Cyp26B1 which are known to be RA-responsive were not expressed at all in the developing eye. At much earlier stages, the expression domain of Shh in the prechordal plate was reduced, as was Nkx2.1 and we suggest a model whereby the eye field is specified according to the concentration of SHH protein that is present. We also describe another organ, Rathke's pouch which fails to develop in the absence of retinoic acid. We attribute this to the down-regulation of Bmp2, Shh and Fgf8 which are known to be involved in the induction of this structure.

  10. 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....

  11. Specificity of a retinoic acid response element in the phosphoenolpyruvate carboxykinase gene promoter: consequences of both retinoic acid and thyroid hormone receptor binding.

    PubMed Central

    Lucas, P C; Forman, B M; Samuels, H H; Granner, D K

    1991-01-01

    The ability of a retinoic acid (RA) response element (RARE) in the phosphoenolpyruvate carboxykinase (PEPCK) gene promoter to mediate effects of either RA or thyroid hormone (T3) on gene expression was studied. Fusion gene constructs consisting of PEPCK promoter sequences ligated to the chloramphenicol acetyltransferase (CAT) reporter gene were used for this analysis. While T3 induced CAT expression to a small degree (about twofold) when such constructs were transiently transfected into H4IIE rat hepatoma cells, along with an expression vector encoding the alpha subtype of the T3 receptor (TR), this effect was mediated by promoter sequences distinct from the PEPCK RARE. Although TRs were capable of binding the PEPCK RARE in the form of putative monomers, dimers, and heterodimers with RA receptors (RARs), this element failed to mediate any positive effect of T3 on gene expression. In contrast, the PEPCK RARE mediated six- to eightfold induction of CAT expression by RA. When TRs were coexpressed along with RARs in transfected H4IIE cells, this RA induction was substantially blunted in a T3-independent manner. This inhibitory effect may be due to the binding of nonfunctional TRs or TR-RAR heterodimers to the PEPCK RARE. A model is proposed to explain the previously observed in vivo effects of T3 on PEPCK gene expression. Images PMID:1656224

  12. Retinoic Acid Receptor β Controls Development of Striatonigral Projection Neurons through FGF-Dependent and Meis1-Dependent Mechanisms.

    PubMed

    Rataj-Baniowska, Monika; Niewiadomska-Cimicka, Anna; Paschaki, Marie; Szyszka-Niagolov, Monika; Carramolino, Laura; Torres, Miguel; Dollé, Pascal; Krężel, Wojciech

    2015-10-28

    The mammalian striatum controls sensorimotor and psychoaffective functions through coordinated activities of its two striatonigral and striatopallidal output pathways. Here we show that retinoic acid receptor β (RARβ) controls development of a subpopulation of GABAergic, Gad65-positive striatonigral projection neurons. In Rarb(-/-) knock-out mice, concomitant reduction of Gad65, dopamine receptor D1 (Drd1), and substance P expression at different phases of prenatal development was associated with reduced number of Drd1-positive cells at birth, in contrast to normal numbers of striatopallidal projection neurons expressing dopamine receptor D2. Fate mapping using BrdU pulse-chase experiments revealed that such deficits may originate from compromised proliferation of late-born striosomal neurons and lead to decreased number of Drd1-positive cells retaining BrdU in postnatal day (P) 0 Rarb(-/-) striatum. Reduced expression of Fgf3 in the subventricular zone of the lateral ganglionic eminence (LGE) at embryonic day 13.5 may underlie such deficits by inducing premature differentiation of neuronal progenitors, as illustrated by reduced expression of the proneural gene Ascl1 (Mash1) and increased expression of Meis1, a marker of postmitotic LGE neurons. In agreement with a critical role of FGF3 in this control, reduced number of Ascl1-expressing neural progenitors, and a concomitant increase of Meis1-expressing cells, were observed in primary cell cultures of Rarb(-/-) LGE. This defect was normalized by addition of fibroblast growth factor (FGF). Such data point to role of Meis1 in striatal development, also supported by reduced neuronal differentiation in the LGE of Meis1(-/-) embryos. Our data unveil a novel mechanism of development of striatonigral projection neurons involving retinoic acid and FGF, two signals required for positioning the boundaries of Meis1-expressing cells.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Redox balance influences differentiation status of neuroblastoma in the presence of all-trans retinoic acid

    PubMed Central

    Silvis, Anne M.; McCormick, Michael L.; Spitz, Douglas R.; Kiningham, Kinsley K.

    2015-01-01

    Neuroblastoma is the most common extra-cranial solid tumor in childhood; and patients in stage IV of the disease have a high propensity for tumor recurrence. Retinoid therapy has been utilized as a means to induce differentiation of tumor cells and to inhibit relapse. In this study, the expression of a common neuronal differentiation marker [neurofilament M (NF-M)] in human SK-N-SH neuroblastoma cells treated with 10 μM all-trans retinoic acid (ATRA) showed significantly increased expression in accordance with reduced cell number. This was accompanied by an increase in MitoSOX and DCFH2 oxidation that could be indicative of increased steady-state levels of reactive oxygen species (ROS) such as O2•− and H2O2, which correlated with increased levels of MnSOD activity and immuno-reactive protein. Furthermore PEG-catalase inhibited the DCFH2 oxidation signal to a greater extent in the ATRA-treated cells (relative to controls) at 96 h indicating that as the cells became more differentiated, steady-state levels of H2O2 increased in the absence of increases in peroxide-scavenging antioxidants (i.e., glutathione, glutathione peroxidase, and catalase). In addition, ATRA-induced stimulation of NF-M at 48 and 72 h was enhanced by decreasing SOD activity using siRNA directed at MnSOD. Finally, treatment with ATRA for 96 h in the presence of MnSOD siRNA or PEG-catalase inhibited ATRA induced increases in NF-M expression. These results provide strong support for the hypothesis that changes in steady-state levels of O2•− and H2O2 significantly contribute to the process of ATRA-induced differentiation in neuroblastoma, and suggest that retinoid therapy for neuroblastoma could potentially be enhanced by redox-based manipulations of superoxide metabolism to improve patient outcome. PMID:26678800

  18. The role of CYP26 enzymes in defining appropriate retinoic acid exposure during embryogenesis.

    PubMed

    Pennimpede, Tracie; Cameron, Don A; MacLean, Glenn A; Li, Hui; Abu-Abed, Suzan; Petkovich, Martin

    2010-10-01

    Retinoic acid (RA) is a pleiotropic derivative of vitamin A, or retinol, which is responsible for all of the bioactivity associated with this vitamin. The teratogenic influences of vitamin A deficiency and excess RA in rodents were first observed more than 50 years ago. Efforts over the last 15-20 years have refined these observations by defining the molecular mechanisms that control RA availability and signaling during murine embryonic development. This review will discuss our current understanding of the role of RA in teratogenesis, with specific emphasis on the essential function of the RA catabolic CYP26 enzymes in preventing teratogenic consequences caused by uncontrolled distribution of RA. Particular focus will be paid to the RA-sensitive tissues of the caudal and cranial regions, the limb, and the testis, and how genetic mutation of factors controlling RA distribution have revealed important roles for RA during embryogenesis.

  19. Improvement in Aqueous Solubility of Retinoic Acid Receptor (RAR) Agonists by Bending the Molecular Structure.

    PubMed

    Hiramatsu, Michiaki; Ichikawa, Yuki; Tomoshige, Shusuke; Makishima, Makoto; Muranaka, Atsuya; Uchiyama, Masanobu; Yamaguchi, Takao; Hashimoto, Yuichi; Ishikawa, Minoru

    2016-08-01

    Aqueous solubility is a key requirement for many functional molecules, e. g., drug candidates. Decrease of the partition coefficient (log P) by chemical modification, i.e., introduction of hydrophilic group(s) into molecules, is a classical strategy for improving aqueous solubility. We have been investigating alternative strategies for improving the aqueous solubility of pharmaceutical compounds by disrupting intermolecular interactions. Here, we show that introducing a bend into the molecular structure of retinoic acid receptor (RAR) agonists by changing the substitution pattern from para to meta or ortho dramatically enhances aqueous solubility by up to 890-fold. We found that meta analogs exhibit similar hydrophobicity to the parent para compound, and have lower melting points, supporting the idea that the increase of aqueous solubility was due to decreased intermolecular interactions in the solid state as a result of the structural changes.

  20. Isolation and characterization of all-trans-retinoic acid-responsive genes in the rat testis.

    PubMed

    Gaemers, I C; Van Pelt, A M; Themmen, A P; De Rooij, D G

    1998-05-01

    By way of differential screening of testis cDNA libraries from vitamin A-deficient (VAD) rats before and after administration of all-trans retinoic acid (ATRA), genes, the transcription of which was influenced by ATRA, were isolated. Most clones with an increased transcription encoded different subunits of the same mitochondrial protein complex, cytochrome c oxidase (COX). The mRNA expression of COX increased by a factor 3.9 +/- 1.5 (mean +/- SD, n = 4). This increased expression seems to reflect an increased energy demand in the ATRA-supplemented VAD testis. Also, one gene was isolated, the transcription of which was reduced to about 70% by ATRA. This gene, sulfated glycoprotein 2 (Sgp-2), is a major secretion product of Sertoli cells, the function of which is still unknown. The effect of ATRA on Sgp-2 expression may be direct, since the promoter of Sgp-2 contains a putative ATRA-responsive element (RARE). PMID:9547504

  1. Rational Design of a Colorimetric pH Sensor from a Soluble Retinoic Acid Chaperone

    PubMed Central

    Berbasova, Tetyana; Nosrati, Meisam; Vasileiou, Chrysoula; Wang, Wenjing; Lee, Kin Sing Stephen; Yapici, Ipek; Geiger, James H.; Borhan, Babak

    2014-01-01

    Reengineering of cellular retinoic acid binding protein II (CRABPII) to be capable of binding retinal as a protonated Schiff base is described. Through rational alterations of the binding pocket, electrostatic perturbations of the embedded retinylidene chromophore that favor delocalization of the iminium charge lead to exquisite control in the regulation of chromophoric absorption properties, spanning the visible spectrum (474–640 nm). The pKa of the retinylidene protonated Schiff base was modulated from 2.4 to 8.1, giving rise to a set of proteins of varying colors and pH sensitivities. These proteins were used to demonstrate a concentration-independent, ratiometric pH sensor. PMID:24059243

  2. Dissecting the Role of Retinoic Acid Receptor Isoforms in the CD8 Response to Infection

    PubMed Central

    Guo, Yanxia; Lee, Yu-Chi; Brown, Chrysothemis; Zhang, Weijun; Usherwood, Edward; Noelle, Randolph J.

    2015-01-01

    Vitamin A deficiency leads to increased susceptibility to a spectrum of infectious diseases. The studies presented dissect the intrinsic role of each of the retinoic acid receptor (RAR) isoforms in the clonal expansion, differentiation, and survival of pathogen-specific CD8 T cells in vivo. The data show that RARα is required for the expression of gut-homing receptors on CD8+ T cells and survival of CD8+ T cells in vitro. Furthermore, RARα is essential for survival of CD8+ T cells in vivo following Listeria monocytogenes infection. In contrast, RARβ deletion leads to modest deficiency in Ag-specific CD8+ T cell expansion during infection. The defective survival of RARα-deficient CD8+ T cells leads to a deficiency in control of L. monocytogenes expansion in the spleen. To our knowledge, these are the first comparative studies of the role of RAR isoforms in CD8+ T cell immunity. PMID:24610012

  3. Rational design of a colorimetric pH sensor from a soluble retinoic acid chaperone.

    PubMed

    Berbasova, Tetyana; Nosrati, Meisam; Vasileiou, Chrysoula; Wang, Wenjing; Lee, Kin Sing Stephen; Yapici, Ipek; Geiger, James H; Borhan, Babak

    2013-10-30

    Reengineering of cellular retinoic acid binding protein II (CRABPII) to be capable of binding retinal as a protonated Schiff base is described. Through rational alterations of the binding pocket, electrostatic perturbations of the embedded retinylidene chromophore that favor delocalization of the iminium charge lead to exquisite control in the regulation of chromophoric absorption properties, spanning the visible spectrum (474-640 nm). The pKa of the retinylidene protonated Schiff base was modulated from 2.4 to 8.1, giving rise to a set of proteins of varying colors and pH sensitivities. These proteins were used to demonstrate a concentration-independent, ratiometric pH sensor. PMID:24059243

  4. Improvement in Aqueous Solubility of Retinoic Acid Receptor (RAR) Agonists by Bending the Molecular Structure.

    PubMed

    Hiramatsu, Michiaki; Ichikawa, Yuki; Tomoshige, Shusuke; Makishima, Makoto; Muranaka, Atsuya; Uchiyama, Masanobu; Yamaguchi, Takao; Hashimoto, Yuichi; Ishikawa, Minoru

    2016-08-01

    Aqueous solubility is a key requirement for many functional molecules, e. g., drug candidates. Decrease of the partition coefficient (log P) by chemical modification, i.e., introduction of hydrophilic group(s) into molecules, is a classical strategy for improving aqueous solubility. We have been investigating alternative strategies for improving the aqueous solubility of pharmaceutical compounds by disrupting intermolecular interactions. Here, we show that introducing a bend into the molecular structure of retinoic acid receptor (RAR) agonists by changing the substitution pattern from para to meta or ortho dramatically enhances aqueous solubility by up to 890-fold. We found that meta analogs exhibit similar hydrophobicity to the parent para compound, and have lower melting points, supporting the idea that the increase of aqueous solubility was due to decreased intermolecular interactions in the solid state as a result of the structural changes. PMID:27378357

  5. Effects of in utero retinoic acid exposure on mouse pelage hair follicle development.

    PubMed

    García-Fernández, Rosa A; Pérez-Martínez, Claudia; Escudero-Diez, Alfredo; García-Iglesias, Maria J

    2002-06-01

    We investigated in vivo the histological and immunohistochemical responses of mouse hair pelage follicle morphogenesis to prenatal exposure to a potentially nonteratogenic dose of all-trans-retinoic acid (RA), as a basis studying the preventive effect of RA on adult mouse skin carcinogenesis. In pregnant mice, a single oral dose of RA at 30 mg kg-1 body weight given on day 11.5 of gestation caused no RA-induced changes in the morphology or temporal expression patterns of keratins during pelage hair follicle morphogenesis. The only differential effect of RA was a statistically significant increase in the number of BrdU-positive nuclei in hair bulbs from RA exposed fetuses compared with nonexposed mice. The absence of adverse RA effects suggests that this experimental design may represent a valuable protocol for use in studies on the in vivo effects of this retinoid on different skin diseases.

  6. Thyroid hormone and retinoic acid interact to regulate zebrafish craniofacial neural crest development.

    PubMed

    Bohnsack, Brenda L; Kahana, Alon

    2013-01-15

    Craniofacial and ocular morphogenesis require proper regulation of cranial neural crest migration, proliferation, survival and differentiation. Although alterations in maternal thyroid hormone (TH) are associated with congenital craniofacial anomalies, the role of TH on the neural crest has not been previously described. Using zebrafish, we demonstrate that pharmacologic and genetic alterations in TH signaling disrupt cranial neural crest migration, proliferation, and survival, leading to craniofacial, extraocular muscle, and ocular developmental abnormalities. In the rostral cranial neural crest that gives rise to the periocular mesenchyme and the frontonasal process, retinoic acid (RA) rescued migratory defects induced by decreased TH signaling. In the caudal cranial neural crest, TH and RA had reciprocal effects on anterior and posterior pharyngeal arch development. The interactions between TH and RA signaling were partially mediated by the retinoid X receptor. We conclude that TH regulates both rostral and caudal cranial neural crest. Further, coordinated interactions of TH and RA are required for proper craniofacial and ocular development.

  7. Thyroid Hormone and Retinoic Acid Interact to Regulate Zebrafish Craniofacial Neural Crest Development

    PubMed Central

    Bohnsack, Brenda L.; Kahana, Alon

    2012-01-01

    Craniofacial and ocular morphogenesis requires proper regulation of cranial neural crest migration, proliferation, survival and differentiation. Although alterations in maternal thyroid hormone (TH) are associated with congenital craniofacial anomalies, the role of TH on the neural crest has not been previously described. Using zebrafish, we demonstrate that pharmacologic and genetic alterations in TH signaling disrupt cranial neural crest migration, proliferation, and survival, leading to craniofacial, extraocular muscle, and ocular developmental abnormalities. In the rostral cranial neural crest that gives rise to the periocular mesenchyme and the frontonasal process, retinoic acid (RA) rescued migratory defects induced by decreased TH signaling. In the caudal cranial neural crest, TH and RA had reciprocal effects on anterior and posterior pharyngeal arch development. The interactions between TH and RA signaling were partially mediated by the retinoid X receptor. We conclude that TH regulates both rostral and caudal cranial neural crest. Further, coordinated interactions of TH and RA are required for proper craniofacial and ocular development. PMID:23165295

  8. Pharmacokinetics and effects on plasma retinol concentrations of 13-cis-retinoic acid in melanoma patients.

    PubMed Central

    Formelli, F.; Cavadini, E.; Mascheroni, L.; Belli, F.; Cascinelli, N.

    1997-01-01

    The pharmacokinetics of 13-cis-retinoic acid (13cisRA) and its effects on retinol plasma levels were investigated after the first and the last doses in melanoma patients, who participated in a study run to assess tolerance over a long period of a treatment schedule of 13cisRA associated with recombinant interferon alpha2a (rIFN-alpha2a). Melanoma patients with regional node metastases after radical surgery were randomized to be treated for 3 months with rIFN-alpha2a, 3 x 10(6) IU s.c. every other day, associated with oral 13cisRA at doses of 20 mg day(-1) (five patients) or 40 mg every other day (seven patients). Maximum 13cisRA blood concentrations usually occurred 4 h after drug administration, with average values of 406 and 633 ng ml(-1) (i.e. 1.3 and 2.1 microM) after the 20 and 40 mg dose respectively. The average half-life (t(1/2)) was approximately 30 h. The maximum concentration, the t(1/2) and the area under the concentration-time curves from 0 to 48 h (AUC(0-48)) of 13cisRA did not change after multiple dosing, whereas the AUC(0-48) of its major blood metabolite, 4-oxo-13-cis-retinoic acid, increased. Immediately after 13cisRA treatment, retinol plasma levels started to decline and they reached the lowest values (approximately 20% reduction) shortly after the time of maximum 13cisRA concentrations (i.e. 4-12 h after drug intake). Afterwards, values returned to baseline. The amount of retinol reduction in time was correlated with 13cisRA maximum concentrations. PMID:9413958

  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. Midkine (MK), the product of a retinoic acid responsive gene, and pleiotrophin constitute a new protein family regulating growth and differentiation.

    PubMed

    Muramatsu, T

    1993-03-01

    Using mouse teratocarcinoma system, we found a novel retinoic acid responsive gene. Midkine (MK), the product of the gene is a secreted, heparin-binding protein of molecular weight 14,000. MK gene is intensely expressed in the midgestation period, and in the adult mouse, the kidney is the principal site of its expression. MK and pleiotrophin have 50% sequence identity and constitute a new protein family regulating growth and differentiation. They share neurite outgrowth activity; other activities, either specific for one or common to both, have been reported. Furthermore, MK is of significant interest in cancer biology.

  11. Allosteric regulation of the discriminative responsiveness of retinoic acid receptor to natural and synthetic ligands by retinoid X receptor and DNA.

    PubMed

    Mouchon, A; Delmotte, M H; Formstecher, P; Lefebvre, P

    1999-04-01

    Transcriptional activation by retinoids is mediated through two families of nuclear receptors, all-trans-retinoic acid (RARs) and 9-cis retinoic acid receptors (RXRs). Conformationally restricted retinoids are used to achieve selective activation of RAR isotype alpha, beta or gamma, which reduces side effects in therapeutical applications. Synthetic retinoids mimic some of all-trans retinoic acid biological effects in vivo but interact differently with the ligand binding domain of RARalpha and induce distinct structural transitions of the receptor. In this report, we demonstrate that RAR-selective ligands have distinct quantitative activation properties which are reflected by their abilities to promote interaction of DNA-bound human RXRalpha (hRXRalpha)-hRARalpha heterodimers with the nuclear receptor coactivator (NCoA) SRC-1 in vitro. The hormone response element core motifs spacing defined the relative affinity of liganded heterodimers for two NCoAs, SRC-1 and RIP140. hRXRalpha activating function 2 was critical to confer hRARalpha full responsiveness but not differential sensitivity of hRARalpha to natural or synthetic retinoids. We also provide evidence showing that lysines located in helices 3 and 4, which define part of hRARalpha NCoA binding surface, contribute differently to (i) the transcriptional activity and (ii) the interaction of RXR-RAR heterodimers with SRC-1, when challenged by either natural or RAR-selective retinoids. Thus, ligand structure, DNA, and RXR exert allosteric regulations on hRARalpha conformation organized as a DNA-bound heterodimer. We suggest that the use of physically distinct NCoA binding interfaces may be important in controlling specific genes by conformationally restricted ligands.

  12. All-Trans Retinoic Acid plus Arsenic Trioxide versus All-Trans Retinoic Acid plus Chemotherapy for Newly Diagnosed Acute Promyelocytic Leukemia: A Meta-Analysis

    PubMed Central

    Ma, Yafang; Liu, Lu; Jin, Jie; Lou, Yinjun

    2016-01-01

    Background Recently, the all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO) protocol has become a promising first-line therapeutic approach in patients with newly diagnosed acute promyelocytic leukemia (APL), but its benefits compared with standard ATRA plus chemotherapy regimen needs to be proven. Herein, we conducted a meta-analysis comparing the efficacy of ATRA plus ATO with ATRA plus chemotherapy for adult patients with newly diagnosed APL. Methods We systematically searched biomedical electronic databases and conference proceedings through February 2016. Two reviewers independently assessed all studies for relevance and validity. Results Overall, three studies were eligible for inclusion in this meta-analysis, which included a total of 585 patients, with 317 in ATRA plus ATO group and 268 in ATRA plus chemotherapy group. Compared with patients who received ATRA and chemotherapy, patients who received ATRA plus ATO had a significantly better event-free survival (hazard ratio [HR] = 0.38, 95% confidence interval [CI]: 0.22–0.67, p = 0.009), overall survival (HR = 0.44, 95% CI: 0.24–0.82, p = 0.009), complete remission rate (relative risk [RR] = 1.05; 95% CI: 1.01–1.10; p = 0.03). There were no significant differences in early mortality (RR = 0.48; 95% CI: 0.22–1.05; p = 0.07). Conclusion Thus, this analysis indicated that ATRA plus ATO protocol may be preferred to standard ATRA plus chemotherapy protocol, particularly in low-to-intermediate risk APL patients. Further larger trials were needed to provide more evidence in high-risk APL patients. PMID:27391027

  13. All-Trans Retinoic Acid and Sodium Butyrate Enhance Natriuretic Peptide Receptor A Gene Transcription: Role of Histone Modification

    PubMed Central

    Kumar, Prerna; Periyasamy, Ramu; Das, Subhankar; Neerukonda, Smitha; Mani, Indra

    2014-01-01

    The objective of the present study was to delineate the mechanisms of GC-A/natriuretic peptide receptor-A (GC-A/NPRA) gene (Npr1) expression in vivo. We used all-trans retinoic acid (ATRA) and histone deacetylase (HDAC) inhibitor, sodium butyrate (NaBu) to examine the expression and function of Npr1 using gene-disrupted heterozygous (1-copy; +/−), wild-type (2-copy; +/+), and gene-duplicated heterozygous (3-copy; ++/+) mice. Npr1+/− mice exhibited increased renal HDAC and reduced histone acetyltransferase (HAT) activity; on the contrary, Npr1++/+ mice showed decreased HDAC and enhanced HAT activity compared with Npr1+/+ mice. ATRA and NaBu promoted global acetylation of histones H3-K9/14 and H4-K12, reduced methylation of H3-K9 and H3-K27, and enriched accumulation of active chromatin marks at the Npr1 promoter. A combination of ATRA-NaBu promoted recruitment of activator-complex containing E26 transformation–specific 1, retinoic acid receptor α, and HATs (p300 and p300/cAMP response element–binding protein-binding protein–associated factor) at the Npr1 promoter, and significantly increased renal NPRA expression, GC activity, and cGMP levels. Untreated 1-copy mice showed significantly increased systolic blood pressure and renal expression of α-smooth muscle actin (α-SMA) and proliferating cell nuclear antigen (PCNA) compared with 2- and 3-copy mice. Treatment with ATRA and NaBu synergistically attenuated the expression of α-SMA and PCNA and reduced systolic blood pressure in Npr1+/− mice. Our findings demonstrate that epigenetic upregulation of Npr1 gene transcription by ATRA and NaBu leads to attenuation of renal fibrotic markers and systolic blood pressure in mice with reduced Npr1 gene copy number, which will have important implications in prevention and treatment of hypertension-related renal pathophysiological conditions. PMID:24714214

  14. Retinoic acid exerts dual regulatory actions on the expression and nuclear localization of interferon regulatory factor-1.

    PubMed

    Luo, Xin M; Ross, A Catharine

    2006-05-01

    Interferon regulatory factor-1 (IRF-1), a transcription factor and tumor suppressor involved in cell growth regulation and immune responses, has been shown to be induced by all-trans retinoic acid (ATRA). However, the factors controlling the cellular location and activity of IRF-1 are not well understood. In this study, we examined the expression of IRF-1 and its nuclear localization, DNA-binding activity, and target gene expression in human mammary epithelial MCF10A cells, a model of breast epithelial cell differentiation and carcinogenesis. Following initial treatment with ATRA, IRF-1 mRNA and protein were induced within 2 hrs, reached a peak (>30-fold induction) at 8 hrs, and declined afterwards. IRF-1 protein was predominantly cytoplasmic during this treatment. Although a second dose of ATRA or Am580 (a related retinoid selective for retinoic acid receptor-alpha [RARalpha]), given 16 hrs after the first dose, restimulated IRF-1 mRNA and protein levels to a similar level to that obtained by the first dose, IRF-1 was predominantly concentrated in the nucleus after restimulation. ATRA and Am580 also increased nuclear RARalpha, whereas retinoid X receptor-alpha (RXRalpha)--a dimerization partner for RARalpha, was localized to the nucleus upon second exposure to ATRA. However, ATRA and Am580 did not regulate the expression or activation of signal transducer and activator of transcription-1 (STAT-1), a transcription factor capable of inducing the expression of IRF-1, indicating an STAT-1-independent mechanism of regulation by ATRA and Am580. The increase in nuclear IRF-1 after retinoid restimulation was accompanied by enhanced binding to an IRF-E DNA response element, and elevated expression of an IRF-1 target gene, 2',5'-oligoadenylate synthetase-2. The dual effect of retinoids in increasing IRF-1 mRNA and protein and in augmenting the nuclear localization of IRF-1 protein may be essential for maximizing the tumor suppressor activity and the immunosurveillance

  15. Altered Retinoic Acid Metabolism in Diabetic Mouse Kidney Identified by 18O Isotopic Labeling and 2D Mass Spectrometry

    PubMed Central

    Starkey, Jonathan M.; Zhao, Yingxin; Sadygov, Rovshan G.; Haidacher, Sigmund J.; LeJeune, Wanda S.; Dey, Nilay; Luxon, Bruce A.; Kane, Maureen A.; Napoli, Joseph L.; Denner, Larry; Tilton, Ronald G.

    2010-01-01

    Background Numerous metabolic pathways have been implicated in diabetes-induced renal injury, yet few studies have utilized unbiased systems biology approaches for mapping the interconnectivity of diabetes-dysregulated proteins that are involved. We utilized a global, quantitative, differential proteomic approach to identify a novel retinoic acid hub in renal cortical protein networks dysregulated by type 2 diabetes. Methodology/Principal Findings Total proteins were extracted from renal cortex of control and db/db mice at 20 weeks of age (after 12 weeks of hyperglycemia in the diabetic mice). Following trypsinization, 18O- and 16O-labeled control and diabetic peptides, respectively, were pooled and separated by two dimensional liquid chromatography (strong cation exchange creating 60 fractions further separated by nano-HPLC), followed by peptide identification and quantification using mass spectrometry. Proteomic analysis identified 53 proteins with fold change ≥1.5 and p≤0.05 after Benjamini-Hochberg adjustment (out of 1,806 proteins identified), including alcohol dehydrogenase (ADH) and retinaldehyde dehydrogenase (RALDH1/ALDH1A1). Ingenuity Pathway Analysis identified altered retinoic acid as a key signaling hub that was altered in the diabetic renal cortical proteome. Western blotting and real-time PCR confirmed diabetes-induced upregulation of RALDH1, which was localized by immunofluorescence predominantly to the proximal tubule in the diabetic renal cortex, while PCR confirmed the downregulation of ADH identified with mass spectrometry. Despite increased renal cortical tissue levels of retinol and RALDH1 in db/db versus control mice, all-trans-retinoic acid was significantly decreased in association with a significant decrease in PPARβ/δ mRNA. Conclusions/Significance Our results indicate that retinoic acid metabolism is significantly dysregulated in diabetic kidneys, and suggest that a shift in all-trans-retinoic acid metabolism is a novel feature in

  16. DIFFERENTIAL EXPRESSION OF RETINOIC ACID BIOSYNTHETIC AND METABOLISM GENES IN LIVERS FROM MICE TREATED WITH HEPATOTUMORIGENIC AND NON-HEPATOTUMORIGENIC CONAZOLES

    EPA Science Inventory

    Conazoles are fungicides used in crop protection and as pharmaceuticals. Triadimefon and propiconazole are hepatotumorigenic in mice, while myclobutanil is not. Previous toxicogenomic studies suggest that alteration of the retinoic acid metabolism pathway may play a key event in ...

  17. ALTERATIONS IN A11 TRANS RETINOIC ACID METABOLISM IN LIVER MICROSOMES FROM MICE TREATED WITH HEPATOTUMORIGENIC AND NON-HEPATOTUMORIGENIC CONAZOLES

    EPA Science Inventory

    Conazoles are fungicides used in crop protection and as pharmaceuticals. Triadimefon and propiconazole are hepatotumorigenic in mice, while myclobutanil is not. Previous toxicogenomic studies suggest that alteration of the retinoic acid metabolism pathway may be a key event in co...

  18. Oral Accutane (13-cis-retinoic acid) has no effects on spatial learning and memory in male and female Sprague-Dawley rats.

    PubMed

    Ferguson, Sherry A; Berry, Kimberly J

    2007-01-01

    Descriptions of psychiatric effects with Accutane (13-cis-retinoic acid (13-cis-RA)) use prompted a series of studies in a rodent model to ascertain its cognitive effects. Previously, we reported no effects on measures of anhedonia and depression in rats treated with 7.5, 22.5, or 30 mg/kg 13-cis-RA [S.A. Ferguson, F.J. Cisneros, B. Gough, J.P. Hanig, K.J. Berry, Chronic oral treatment with 13-cis-retinoic acid (isotretinoin) or all-trans-retinoic acid does not alter depression-like behaviors in rats, Toxicol. Sci. 87 (2005) 451-459 [16]; S.A. Ferguson, F.J., Cisneros, J.P. Hanig, K.J. Berry, Chronic oral treatment with Accutane (13-cis-retinoic acid) does not increase measures of anhedonia or depression in male and female Sprague-Dawley rats, (in preparation) [19

  19. Investigation of Retinoic Acid Function During Embryonic Brain Development Using Retinaldehyde-Rescued Rdh10 Knockout Mice

    PubMed Central

    Chatzi, Christina; Cunningham, Thomas J.; Duester, Gregg

    2013-01-01

    Background Retinoic acid (RA) signaling controls patterning and neuronal differentiation within the hindbrain, but forebrain RA function remains controversial. RA is produced from metabolism of retinol to retinaldehyde by retinol dehydrogenase (RDH), followed by metabolism of retinaldehyde to RA by retinaldehyde dehydrogenase (RALDH). Previous studies on Raldh2−/− and Raldh3−/− mice demonstrated an RA requirement for γ-aminobutyric acid (GABA)ergic and dopaminergic differentiation in forebrain basal ganglia, but no RA requirement was observed during early forebrain patterning or subsequent fore-brain cortical expansion. However, other studies suggested that RA controls forebrain patterning, and analysis of ethylnitrosourea-induced Rdh10 mutants suggested that RA synthesized in the meninges stimulates forebrain cortical expansion. Results We generated Rdh10−/− mouse embryos that lack RA activity early in the head and later in the meninges. We observed defects in hindbrain patterning and eye RA signaling, but early forebrain patterning was unaffected. Retinaldehyde treatment of Rdh10−/− embryos from E7–E9 rescues a cranial skeletal defect, resulting in E14.5 embryos lacking meningeal RA activity but maintaining normal forebrain shape and cortical expansion. Conclusions Rdh10−/− embryos demonstrate that RA controls hindbrain but not early forebrain patterning, while studies on retinaldehyde-rescued Rdh10−/− embryos show that meningeal RA synthesis is unnecessary to stimulate forebrain cortical expansion. PMID:23765990

  20. Effects of receptor-selective retinoids on CYP26 gene expression and metabolism of all-trans-retinoic acid in intestinal cells.

    PubMed

    Lampen, A; Meyer, S; Nau, H

    2001-05-01

    Retinoids mediate most of their function via interaction with retinoid receptors [retinoic acid receptors (RARs) and retinoid X receptors (RXRs)], which act as ligand-activated transcription factors controlling the expression of a number of target genes. The complex mechanistic pattern of retinoid-induced effects on gene expression of CYP26 and intestinal metabolism of all-trans-retinoic acid (RA) was investigated here by studying the effects of retinoid ligands with relative selectivity for binding and transactivation of the retinoid acid receptors, RARs and RXRs, in human intestinal Caco-2 cells. We show here that CYP26 is expressed in human duodenum and colon. In Caco-2 cells not only all-trans-RA but also synthetic agonists of the RAR induced intestinal CYP26 gene expression and all-trans-RA metabolism as well. The RARalpha ligand Am580 induced the CYP26 gene expression more than the RARbeta ligand CD2019 or the RARgamma ligand CD437 suggesting the highest specificity for RARalpha on intestinal CYP26 gene regulation. RXR ligands alone did not induce CYP26 gene expression or RA metabolism in Caco-2 cells at all. But together with the RARalpha ligand, Am580, there were enhanced effects on the induction of CYP26 gene expression and on the induction of the metabolism of all-trans-RA. We conclude that gene regulation of CYP26 and the metabolism of all-trans-RA in intestinal cells is regulated through RXR and RAR heterodimerization. When coadministered, RAR agonists showed the highest potency for CYP26 gene regulation. Receptor-selective retinoids showed enhanced effects on induction of CYP26 gene expression and all-trans-retinoic acid metabolism.

  1. Molecular mechanism of 9-cis-retinoic acid inhibition of adipogenesis in 3T3-L1 cells

    SciTech Connect

    Sagara, Chiaki; Takahashi, Katsuhiko; Kagechika, Hiroyuki; Takahashi, Noriko

    2013-03-29

    Highlights: ► We examined the effects of 9-cis-RA on adipogenesis in mouse preadipocyte 3T3-L1. ► 9-cis-RA inhibited lipid accumulation in adipogenetically-induced 3T3-L1 cells. ► A RXR pan-antagonist suppressed the inhibitory effects of 9-cis-RA on adipogenesis. ► This antagonist had no effects on RXRα and PPARγ levels in 9-cis-RA-treated cells. ► 9-cis-RA-induced decrease in both RXRα and PPARγ was independent of RXR activation. -- Abstract: Retinoic acid (RA) signaling is mediated by specific nuclear hormone receptors. Here we examined the effects of 9-cis-RA on adipogenesis in mouse preadipocyte 3T3-L1 cells. 9-cis-RA inhibits the lipid accumulation of adipogenetically induced 3T3-L1 cells. The complex of retinoid X receptor α (RXRα) with peroxisome proliferator-activated receptor γ (PPARγ) is a major transcription factor in the process of adipogenesis, and the levels of these molecules were decreased by 9-cis-RA treatment. A RXR pan-antagonist suppressed 9-cis-RA’s inhibitory effects on adipogenesis, but not on the intracellular levels of both RXRα and PPARγ. These results suggest that 9-cis-RA could inhibit adipogenesis by activating RXR, and decrease both RXR and PPARγs levels in a RXR activation-independent manner.

  2. All trans-retinoic acid analogs promote cancer cell apoptosis through non-genomic Crabp1 mediating ERK1/2 phosphorylation

    PubMed Central

    Persaud, Shawna D.; Park, Sung Wook; Ishigami-Yuasa, Mari; Koyano-Nakagawa, Naoko; Kagechika, Hiroyuki; Wei, Li-Na

    2016-01-01

    All trans retinoic acid (atRA) is one of the most potent therapeutic agents, but extensive toxicity caused by nuclear RA receptors (RARs) limits its clinical application in treating cancer. AtRA also exerts non-genomic activities for which the mechanism remains poorly understood. We determine that cellular retinoic acid binding protein 1 (Crabp1) mediates the non-genomic activity of atRA, and identify two compounds as the ligands of Crabp1 to rapidly and RAR-independently activate extracellular signal regulated kinase 1/2 (ERK1/2). Non-canonically activated ERK activates protein phosphatase 2A (PP2A) and lengthens cell cycle duration in embryonic stem cells (ESC). This is abolished in Crabp1-null ESCs. Re-expressing Crabp1 in Crabp1-negative cancer cells also sensitizes their apoptotic induction by atRA. This study reveals a physiological relevance of the non-genomic action of atRA, mediated by Crabp1, in modulating cell cycle progression and apoptosis induction, and provides a new cancer therapeutic strategy whereby compounds specifically targeting Crabp1 can modulate cell cycle and cancer cell apoptosis in a RAR-independent fashion, thereby avoiding atRA’s toxicity caused by its genomic effects. PMID:26935534

  3. Direct protein-protein interactions and substrate channeling between cellular retinoic acid binding proteins and CYP26B1.

    PubMed

    Nelson, Cara H; Peng, Chi-Chi; Lutz, Justin D; Yeung, Catherine K; Zelter, Alex; Isoherranen, Nina

    2016-08-01

    Cellular retinoic acid binding proteins (CRABPs) bind all-trans-retinoic acid (atRA) tightly. This study aimed to determine whether atRA is channeled directly to cytochrome P450 (CYP) CYP26B1 by CRABPs, and whether CRABPs interact directly with CYP26B1. atRA bound to CRABPs (holo-CRABP) was efficiently metabolized by CYP26B1. Isotope dilution experiments showed that delivery of atRA to CYP26B1 in solution was similar with or without CRABP. Holo-CRABPs had higher affinity for CYP26B1 than free atRA, but both apo-CRABPs inhibited the formation of 4-OH-RA by CYP26B1. Similar protein-protein interactions between soluble binding proteins and CYPs may be important for other lipophilic CYP substrates.

  4. Comparative proteomic analysis of all-trans-retinoic acid treatment reveals systematic posttranscriptional control mechanisms in acute promyelocytic leukemia.

    PubMed

    Harris, Michael N; Ozpolat, Bulent; Abdi, Fadi; Gu, Sheng; Legler, Allison; Mawuenyega, Kwasi G; Tirado-Gomez, Maribel; Lopez-Berestein, Gabriel; Chen, Xian

    2004-09-01

    All-trans-retinoic acid (ATRA) induces growth inhibition, differentiation, and apoptosis in cancer cells, including acute promyelocytic leukemia (APL). In APL, expression of promyelocytic leukemia protein retinoic acid receptor-alpha (PML-RARalpha) fusion protein, owing to the t(15; 17) reciprocal translocation, leads to a block in the promyelocytic stage of differentiation. Here, we studied molecular mechanisms involved in ATRA-induced growth inhibition and myeloid cell differentiation in APL. By employing comprehensive high-throughput proteomic methods of 2-dimensional (2-D) gel electrophoresis and amino acid-coded mass tagging coupled with electrospray ionization (ESI) mass spectrometry, we systematically identified a total of 59 differentially expressed proteins that were consistently modulated in response to ATRA treatment. The data revealed significant down-regulation of eukaryotic initiation and elongation factors, initiation factor 2 (IF2), eukaryotic initiation factor 4AI (eIF4AI), eIF4G, eIF5, eIF6, eukaryotic elongation factor 1A-1 (eEF1A-1), EF-1-delta, eEF1gamma, 14-3-3epsilon, and 14-3-3zeta/delta (P <.05). The translational inhibitor DAP5/p97/NAT1 (death-associated protein 5) and PML isoform-1 were found to be up-regulated (P <.05). Additionally, the down-regulation of heterogeneous nuclear ribonucleoproteins (hnRNPs) C1/C2, UP2, K, and F; small nuclear RNPs (snRNPs) D3 and E; nucleoprotein tumor potentiating region (TPR); and protein phosphatase 2A (PP2A) were found (P <.05); these were found to function in pre-mRNA processing, splicing, and export events. Importantly, these proteomic findings were validated by Western blot analysis. Our data in comparison with previous cDNA microarray studies and our reverse transcription-polymerase chain reaction (RT-PCR) experiments demonstrate that broad networks of posttranscriptional suppressive pathways are activated during ATRA-induced growth inhibition processes in APL. PMID:15142884

  5. Regulation of Expression of Citrate Synthase by the Retinoic Acid Receptor-Related Orphan Receptor α (RORα)

    PubMed Central

    Crumbley, Christine; Wang, Yongjun; Banerjee, Subhashis; Burris, Thomas P.

    2012-01-01

    The retinoic acid receptor-related orphan receptor α (RORα) is a member of the nuclear receptor superfamily of transcription factors that plays an important role in regulation of the circadian rhythm and metabolism. Mice lacking a functional RORα display a range of metabolic abnormalities including decreased serum cholesterol and plasma triglycerides. Citrate synthase (CS) is a key enzyme of the citric acid cycle that provides energy for cellular function. Additionally, CS plays a critical role in providing citrate derived acetyl-CoA for lipogenesis and cholesterologenesis. Here, we identified a functional RORα response element (RORE) in the promoter of the CS gene. ChIP analysis demonstrates RORα occupancy of the CS promoter and a putative RORE binds to RORα effectively in an electrophoretic mobility shift assay and confers RORα responsiveness to a reporter gene in a cotransfection assay. We also observed a decrease in CS gene expression and CS enzymatic activity in the staggerer mouse, which has a mutation of in the Rora gene resulting in nonfunctional RORα protein. Furthermore, we found that SR1001 a RORα inverse agonist eliminated the circadian pattern of expression of CS mRNA in mice. These data suggest that CS is a direct RORα target gene and one mechanism by which RORα regulates lipid metabolism is via regulation of CS expression. PMID:22485150

  6. Retinoic acid regulates CD1d gene expression at the transcriptional level in human and rodent monocytic cells.

    PubMed

    Chen, Qiuyan; Ross, A Catharine

    2007-04-01

    CD1d belongs to a group of nonclassical antigen-presenting molecules that present glycolipid antigens and thereby activate natural killer T (NKT) cells, a subset of bifunctional T cells. Little is known so far regarding the expression and physiologic regulation of CD1d. Here we show that all-trans-retinoic acid (RA), the active metabolite of vitamin A, rapidly (1 hr after treatment) increases CD1d mRNA in human and rodent monocytic cells at a physiologic dose (10 nM). The induction is RA specific and RA receptor (RAR) dependent-RA and an RARalpha agonist, Am580, both had a pronounced positive effect, whereas the addition of RARalpha antagonist partially blocked the increase in CD1d mRNA induced by RA and Am580. The induction was also completely blocked by the presence of actinomycin D. A putative RA-response element was identified in the distal 5' flanking region of the CD1d gene, which binds nuclear retinoid receptors and was responsive to RA in both gel mobility shift assay and transient transfection assay in THP-1 cells. These results further confirmed the transcriptional regulation of RA in CD1d gene expression. Moreover, RA significantly increased alpha-galactosylceramide-induced spleen cell proliferation. These studies together provide evidence for a previously unknown mechanism of CD1d gene expression regulation by RA and suggest that RA is a significant modulator of NKT cell activation.

  7. Delayed translocation of NGFI-B/RXR in glutamate stimulated neurons allows late protection by 9-cis retinoic acid

    SciTech Connect

    Mathisen, Gro H.; Fallgren, Asa B.; Strom, Bjorn O.; Boldingh Debernard, Karen A.; Mohebi, Beata U.; Paulsen, Ragnhild E.

    2011-10-14

    Highlights: {yields} NGFI-B and RXR translocate out of the nucleus after glutamate treatment. {yields} Arresting NGFI-B/RXR in the nucleus protects neurons from excitotoxicity. {yields} Late protection by 9-cis RA is possible due to a delayed translocation of NGFI-B/RXR. -- Abstract: Nuclear receptor and apoptosis inducer NGFI-B translocates out of the nucleus as a heterodimer with RXR in response to different apoptosis stimuli, and therefore represents a potential pharmacological target. We found that the cytosolic levels of NGFI-B and RXR{alpha} were increased in cultures of cerebellar granule neurons 2 h after treatment with glutamate (excitatory neurotransmitter in the brain, involved in stroke). To find a time-window for potential intervention the neurons were transfected with gfp-tagged expressor plasmids for NGFI-B and RXR. The default localization of NGFI-Bgfp and RXRgfp was nuclear, however, translocation out of the nucleus was observed 2-3 h after glutamate treatment. We therefore hypothesized that the time-window between treatment and translocation would allow late protection against neuronal death. The RXR ligand 9-cis retinoic acid was used to arrest NGFI-B and RXR in the nucleus. Addition of 9-cis retinoic acid 1 h after treatment with glutamate reduced the cytosolic translocation of NGFI-B and RXR{alpha}, the cytosolic translocation of NGFI-Bgfp observed in live neurons, as well as the neuronal death. However, the reduced translocation and the reduced cell death were not observed when 9-cis retinoic acid was added after 3 h. Thus, late protection from glutamate induced death by addition of 9-cis retinoic acid is possible in a time-window after apoptosis induction.

  8. Genital ulcers during treatment with ALL-trans retinoic acid for acute promyelocytic leukemia.

    PubMed

    Fukuno, Kenji; Tsurumi, Hisashi; Goto, Hideko; Oyama, Masami; Tanabashi, Shinobu; Moriwaki, Hisataka

    2003-11-01

    Scrotal ulcer is a unique adverse effect of all-trans retinoic acid (ATRA) in patients with acute promyelocytic leukemia (APL). The pathogenesis of scrotal ulceration remains unknown. We describe genital ulcers that developed in four patients with APL who were undergoing ATRA therapy (45 mg/m2 per day p.o.). Two of the patients were female, in whom this condition is quite rare. Genital ulcers with concomitant fever appeared between 17 and 32 days of therapy in all four patients. Genital ulcers healed in three of the patients while another patient developed Fournier's gangrene and underwent left testectomy. Ulcer healing was brought by either local or intravenous corticosteroids. Intravenous dexamethasone actually enabled continued ATRA administration in one patient, while ATRA was discontinued in other two patients. If corticosteroids cannot control progression of genital ulcers nor concomitant fever, ATRA administration should be discontinued so as not to induce Fournier's gangrene nor retionic acid syndrome. Our experience indicates the importance of recognizing genital ulcers associated with ATRA in order that appropriate countermeasures can be taken.

  9. Proinsulin C-peptide antagonizes the profibrotic effects of TGF-beta1 via up-regulation of retinoic acid and HGF-related signaling pathways.

    PubMed

    Hills, Claire E; Willars, Gary B; Brunskill, Nigel J

    2010-04-01

    Novel signaling roles for C-peptide have recently been discovered with evidence that it can ameliorate complications of type 1 diabetes. Here we sought to identify new pathways regulated by C-peptide of relevance to the pathophysiology of diabetic nephropathy. Microarray analysis was performed to identify genes regulated by either C-peptide and/or TGF-beta1 in a human proximal tubular cell line, HK-2. Expression of retinoic acid receptor beta (RARbeta), hepatocyte growth factor (HGF), cellular retinoic acid-binding protein II (CRABPII), vimentin, E-cadherin, Snail, and beta-catenin was assessed by immunoblotting. The cellular localization of vimentin and beta-catenin was determined by immunocytochemistry. Changes in cell morphology were assessed by phase contrast microscopy. Gene expression profiling demonstrated differential expression of 953 and 1458 genes after C-peptide exposure for 18 h or 48 h, respectively. From these, members of the antifibrotic retinoic acid (RA)- and HGF-signaling pathways were selected. Immunoblotting demonstrated that C-peptide increased RARbeta, CRABPII, and HGF. We confirmed a role for RA in reversal of TGF-beta1-induced changes associated with epithelial-mesenchymal transition, including expression changes in Snail, E-cadherin, vimetin, and redistribution of beta-catenin. Importantly, these TGF-beta1-induced changes were inhibited by C-peptide. Further, effects of TGF-beta1 on Snail and E-cadherin expression were blocked by HGF, and inhibitory effects of C-peptide were removed by blockade of HGF activity. This study identifies a novel role for HGF as an effector of C-peptide, possibly via an RA-signaling pathway, highlighting C-peptide as a potential therapy for diabetic nephropathy. PMID:20197308

  10. Molecular Pathways: Current Role and Future Directions of the Retinoic Acid Pathway In Cancer Prevention and Treatment

    PubMed Central

    Connolly, Roisin M.; Nguyen, Nguyen K.; Sukumar, Saraswati

    2013-01-01

    Retinoids and their naturally metabolized and synthetic products (e.g. all-trans retinoic acid, 13-cis retinoic acid, bexarotene) induce differentiation in various cell types. Retinoids exert their actions mainly through binding to the nuclear retinoic acid receptors (α, β, γ), which are transcriptional and homeostatic regulators whose functions are often compromised early in neoplastic transformation. The retinoids have been investigated extensively for their utility in cancer prevention and treatment. Success has been achieved with their use in the treatment of subtypes of leukemia harboring chromosomal translocations. Promising results have been observed in the breast cancer prevention setting, where fenretinide prevention trials have provided a strong rationale for further investigation in young women at high-risk for breast cancer. Ongoing phase 3 randomized trials investigating retinoids in combination with chemotherapy in non-small cell lung cancer aim to definitively characterize the role of retinoids in this tumor type. The limited treatment success observed to date in the prevention and treatment of solid tumors may relate to the frequent epigenetic silencing of RARβ. Robust evaluation of RARβ and downstream genes may permit optimized use of retinoids in the solid tumor arena. PMID:23322901

  11. Vitamin A increases nerve growth factor and retinoic acid receptor beta and improves diabetic neuropathy in rats.

    PubMed

    Hernández-Pedro, Norma; Granados-Soto, Vinicio; Ordoñez, Graciela; Pineda, Benjamin; Rangel-López, Edgar; Salazar-Ramiro, Aleli; Arrieta, Oscar; Sotelo, Julio

    2014-09-01

    All-trans retinoic acid (ATRA) promotes the endogenous expression of both nerve growth factor (NGF) and retinoic acid receptor beta (RAR-β). We have previously shown that the administration of ATRA partly reverts the damage induced by diabetic neuropathy (DN). In this investigation, we evaluated the effects of vitamin A, a commercial, inexpensive compound of retinoic acid, on the therapy of DN. A total of 70 rats were randomized into 4 groups. Group A was the control, and groups B, C, and D received a total dose of 60 mg/kg streptozotocin intraperitoneally. When signs of DN developed, groups C and D were treated either with vitamin A (20,000 IU) or with ATRA 25 mg/kg for 60 days. Plasma glucose, contents of NGF, thermal and nociceptive tests, and RAR-β expression were evaluated. All diabetic rats developed neuropathy. The treatment with vitamin A and ATRA reverted similarly the sensorial disturbances, which was associated with increased contents of NGF and RAR-β expression. Our results indicate that the administration of vitamin A has the same therapeutic effect as ATRA on peripheral neuropathy and suggest its potential therapeutic use in patients with diabetes.

  12. Combined Effects of Retinoic Acid and Hydro-Alcoholic Extract of Rosa Damascena Mill on Wound in Diabetic Rats.

    PubMed

    Mansouri, Esrafil; Hardani, Ameneh; Afzalzadeh, Mohamad Reza; Amir Zargar, Ashraf; Meamar, Zakiaeh

    2016-01-01

    Retinoic acid and Rosa damascena are compounds that have considerable effects in the cellular proliferation and synthesis of extracellular matrix. The present study was designed to assess the combined effects of retinoic acid and Rosa damascena mill on wound in diabetic rats. Seventy-two rats were used in this study. Diabetes was induced by a single intraperitoneal injection of streptozotocin (60 mg. Kg(-1)). Then, a full thickness wound was created on dorsal surface of all animals. After that, rats were divided, into three groups; control (normal saline), positive control (Phenytoin), and  case (combined of 0.1% Tretinoein lotion and hydro-alcoholic extract of Rosa damascena mill). Afterward, wounds were evaluated macroscopically and microscopically on days 5, 10 and 15. Macroscopic and microscopic evaluations showed a significant improvement (p<0.05) of wounds in case group on 5(th) and 10(th) days when compared to positive control and control groups. The combination of Retinoic acid and hydro-alcholic extract of Rosa damascena mill can accelerate wound healing in diabetic rats.

  13. Combined Effects of Retinoic Acid and Hydro-Alcoholic Extract of Rosa Damascena Mill on Wound in Diabetic Rats.

    PubMed

    Mansouri, Esrafil; Hardani, Ameneh; Afzalzadeh, Mohamad Reza; Amir Zargar, Ashraf; Meamar, Zakiaeh

    2016-01-01

    Retinoic acid and Rosa damascena are compounds that have considerable effects in the cellular proliferation and synthesis of extracellular matrix. The present study was designed to assess the combined effects of retinoic acid and Rosa damascena mill on wound in diabetic rats. Seventy-two rats were used in this study. Diabetes was induced by a single intraperitoneal injection of streptozotocin (60 mg. Kg(-1)). Then, a full thickness wound was created on dorsal surface of all animals. After that, rats were divided, into three groups; control (normal saline), positive control (Phenytoin), and  case (combined of 0.1% Tretinoein lotion and hydro-alcoholic extract of Rosa damascena mill). Afterward, wounds were evaluated macroscopically and microscopically on days 5, 10 and 15. Macroscopic and microscopic evaluations showed a significant improvement (p<0.05) of wounds in case group on 5(th) and 10(th) days when compared to positive control and control groups. The combination of Retinoic acid and hydro-alcholic extract of Rosa damascena mill can accelerate wound healing in diabetic rats. PMID:27642329

  14. Combined Effects of Retinoic Acid and Hydro-Alcoholic Extract of Rosa Damascena Mill on Wound in Diabetic Rats

    PubMed Central

    Mansouri, Esrafil; Hardani, Ameneh; Afzalzadeh, Mohamad Reza; Amir zargar, Ashraf; Meamar, Zakiaeh

    2016-01-01

    Retinoic acid and Rosa damascena are compounds that have considerable effects in the cellular proliferation and synthesis of extracellular matrix. The present study was designed to assess the combined effects of retinoic acid and Rosa damascena mill on wound in diabetic rats. Seventy-two rats were used in this study. Diabetes was induced by a single intraperitoneal injection of streptozotocin (60 mg. Kg-1). Then, a full thickness wound was created on dorsal surface of all animals. After that, rats were divided, into three groups; control (normal saline), positive control (Phenytoin), and  case (combined of 0.1% Tretinoein lotion and hydro-alcoholic extract of Rosa damascena mill). Afterward, wounds were evaluated macroscopically and microscopically on days 5, 10 and 15. Macroscopic and microscopic evaluations showed a significant improvement (p<0.05) of wounds in case group on 5th and 10th days when compared to positive control and control groups. The combination of Retinoic acid and hydro-alcholic extract of Rosa damascena mill can accelerate wound healing in diabetic rats. PMID:27642329

  15. Retinoic acid facilitates inactivated transmissible gastroenteritis virus induction of CD8(+) T-cell migration to the porcine gut.

    PubMed

    Chen, Xiaojuan; Tu, Chongzhi; Qin, Tao; Zhu, Liqi; Yin, Yinyan; Yang, Qian

    2016-01-01

    The digestive tract is the entry site for transmissible gastroenteritis virus (TGEV). TGEV transmission can be prevented if local immunity is established with increased lymphocytes. The current parenteral mode of vaccination stimulates systemic immunity well, but it does not induce sufficient mucosal immunity. Retinoic acid (RA) plays an important role in the induction of cells that imprint gut-homing molecules. We examined whether RA assist parenteral vaccination of pigs could improve mucosal immunity. We demonstrated that elevated numbers of gut-homing CD8(+) T cells (which express α4β7 and CCR9 molecules) were presented in porcine inguinal lymph nodes and were recruited to the small intestine by RA. Intestinal mucosal immunity (IgA titre) and systemic immunity (serum IgG titre) were enhanced by RA. Therefore, we hypothesized that RA could induce DCs to form an immature mucosal phenotype and could recruit them to the small intestinal submucosa. Porcine T-cells expressed β7 integrin and CCR9 receptors and migrated to CCL25 by a mechanism that was dependent of activation by RA-pretreated DCs, rather than direct activation by RA. Together, our results provide powerful evidence that RA can assist whole inactivated TGEV (WI-TGEV) via subcutaneous (s.c.) immunization to generate intestinal immunity, and offer new vaccination strategies against TGEV. PMID:27080036

  16. Modulation of docetaxel-induced apoptosis and cell cycle arrest by all- trans retinoic acid in prostate cancer cells

    PubMed Central

    Nehmé, A; Varadarajan, P; Sellakumar, G; Gerhold, M; Niedner, H; Zhang, Q; Lin, X; Christen, R D

    2001-01-01

    We report that all- trans retinoic acid (ATRA) enhanced the toxicity of docetaxel against DU145 and LNCaP prostate cancer cells, and that the nature of the interaction between ATRA and docetaxel was highly synergistic. Docetaxel-induced apoptotic cell death was associated with phosphorylation and hence inactivation of Bcl-2. ATRA enhanced docetaxel-induced apoptosis and combined treatment with ATRA and docetaxel resulted in down-regulation of Bcl-2. Docetaxel caused phosphorylation and hence inactivation of cdc2 kinase result ing in G2/M arrest. ATRA inhibited docetaxel-induced phosphorylation of cdc2 resulting in activation of cdc2 kinase and partial reversal of the G2/M arrest. ATRA also inhibited docetaxel-induced activation of MAPK indicating that the effects of docetaxel and ATRA on cdc2 phosphorylation are dependent on MAPK. We conclude that ATRA synergistically enhances docetaxel toxicity by down-regulating Bcl-2 expression and partially reverses the docetaxel-induced G2/M arrest by inhibiting docetaxel-induced cdc2 phosphorylation in a pathway that is dependent on MAPK. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11384110

  17. Retinoic acid facilitates inactivated transmissible gastroenteritis virus induction of CD8+ T-cell migration to the porcine gut

    PubMed Central

    Chen, Xiaojuan; Tu, Chongzhi; Qin, Tao; Zhu, Liqi; Yin, Yinyan; Yang, Qian

    2016-01-01

    The digestive tract is the entry site for transmissible gastroenteritis virus (TGEV). TGEV transmission can be prevented if local immunity is established with increased lymphocytes. The current parenteral mode of vaccination stimulates systemic immunity well, but it does not induce sufficient mucosal immunity. Retinoic acid (RA) plays an important role in the induction of cells that imprint gut-homing molecules. We examined whether RA assist parenteral vaccination of pigs could improve mucosal immunity. We demonstrated that elevated numbers of gut-homing CD8+ T cells (which express α4β7 and CCR9 molecules) were presented in porcine inguinal lymph nodes and were recruited to the small intestine by RA. Intestinal mucosal immunity (IgA titre) and systemic immunity (serum IgG titre) were enhanced by RA. Therefore, we hypothesized that RA could induce DCs to form an immature mucosal phenotype and could recruit them to the small intestinal submucosa. Porcine T-cells expressed β7 integrin and CCR9 receptors and migrated to CCL25 by a mechanism that was dependent of activation by RA-pretreated DCs, rather than direct activation by RA. Together, our results provide powerful evidence that RA can assist whole inactivated TGEV (WI-TGEV) via subcutaneous (s.c.) immunization to generate intestinal immunity, and offer new vaccination strategies against TGEV. PMID:27080036

  18. RDH10 is the primary enzyme responsible for the first step of embryonic Vitamin A metabolism and retinoic acid synthesis.

    PubMed

    Farjo, Krysten M; Moiseyev, Gennadiy; Nikolaeva, Olga; Sandell, Lisa L; Trainor, Paul A; Ma, Jian-xing

    2011-09-15

    Retinoic acid (atRA) signaling is essential for regulating embryonic development, and atRA levels must be tightly controlled in order to prevent congenital abnormalities and fetal death which can result from both excessive and insufficient atRA signaling. Cellular enzymes synthesize atRA from Vitamin A, which is obtained from dietary sources. Embryos express multiple enzymes that are biochemically capable of catalyzing the initial step of Vitamin A oxidation, but the precise contribution of these enzymes to embryonic atRA synthesis remains unknown. Using Rdh10(trex)-mutant embryos, dietary supplementation of retinaldehyde, and retinol dehydrogenase (RDH) activity assays, we demonstrate that RDH10 is the primary RDH responsible for the first step of embryonic Vitamin A oxidation. Moreover, we show that this initial step of atRA synthesis occurs predominantly in a membrane-bound cellular compartment, which prevents inhibition by the cytosolic cellular retinol-binding protein (RBP1). These studies reveal that widely expressed cytosolic enzymes with RDH activity play a very limited role in embryonic atRA synthesis under normal dietary conditions. This provides a breakthrough in understanding the precise cellular mechanisms that regulate Vitamin A metabolism and the synthesis of the essential embryonic regulatory molecule atRA.

  19. Cancer procoagulant and tissue factor are differently modulated by all-trans-retinoic acid in acute promyelocytic leukemia cells.

    PubMed

    Falanga, A; Consonni, R; Marchetti, M; Locatelli, G; Garattini, E; Passerini, C G; Gordon, S G; Barbui, T

    1998-07-01

    All-trans-retinoic acid (ATRA) downregulates the expression of two cellular procoagulants, tissue factor (TF) and cancer procoagulant (CP), in human promyelocytic leukemia cells. To evaluate whether or not changes of the procoagulant activities (PCAs) may share mechanisms with the ATRA-induced cyto-differentiation process, we have characterized the effect of ATRA on the TF and CP expression by NB4 cells, an ATRA maturation-inducible cell line, and two NB4-derived cell lines resistant to ATRA-induced maturation, the NB4. 306 and NB4.007/6 cells. Next, we evaluated the effect on the PCAs of the NB4 parental cells of three synthetic retinoid analogues, ie: AM580 (selective for the retinoic acid receptor [RAR] alpha), capable to induce the granulocytic differentiation of NB4 cells; and CD2019 (selective for RARbeta) and CD437 (selective for RARgamma), both lacking this capability. Cells were treated with either ATRA or the analogues (10(-6) to 10(-8) mol/L) for 96 hours. The effect on cell differentiation was evaluated by morphologic changes, cell proliferation, nitro blue tetrazolium reduction assay, and flow cytometry analysis of the CD33 and CD11b surface-antigen expression. PCA was first measured in 20 mmol/L Veronal Buffer cell extracts by the one-stage clotting assay of normal and FVII-deficient plasmas. Further TF and CP have been characterized and quantified in cell-sample preparations by chromogenic and immunological assays. In the first series of experiments, ATRA downregulates both TF and CP in NB4 parental cells, as expected. However, in the differentiation-resistant cell lines, it induced a significant loss of TF but had little or no effect on CP. In a second series of experiments, in the NB4 parental cells, the RARalpha agonist (AM580) induced cell maturation and reduced 91% CP expression, whereas CD437 and CD2019 had no cyto-differentiating effects and did not affect CP levels. On the other hand, in the same cells the TF expression was reduced by ATRA

  20. Functional evidence for ligand-dependent dissociation of thyroid hormone and retinoic acid receptors from an inhibitory cellular factor.

    PubMed Central

    Casanova, J; Helmer, E; Selmi-Ruby, S; Qi, J S; Au-Fliegner, M; Desai-Yajnik, V; Koudinova, N; Yarm, F; Raaka, B M; Samuels, H H

    1994-01-01

    The ligand-binding domains of thyroid hormone (L-triiodothyronine [T3]) receptors (T3Rs), all-trans retinoic acid (RA) receptors (RARs), and 9-cis RA receptors (RARs and RXRs) contain a series of heptad motifs thought to be important for dimeric interactions. Using a chimera containing amino acids 120 to 392 of chicken T3R alpha (cT3R alpha) positioned between the DNA-binding domain of the yeast GAL4 protein and the potent 90-amino-acid transactivating domain of the herpes simplex virus VP16 protein (GAL4-T3R-VP16), we provide functional evidence that binding of ligand releases T3Rs and RARs from an inhibitory cellular factor. GAL4-T3R-VP16 does not bind T3 and does not activate transcription from a GAL4 reporter when expressed alone but is able to activate transcription when coexpressed with unliganded T3R or RAR. This activation is reversed by T3 or RA, suggesting that these receptors compete with GAL4-T3R-VP16 for a cellular inhibitor and that ligand reverses this effect by dissociating T3R or RAR from the inhibitor. A chimera containing the entire ligand-binding domain of cT3R alpha (amino acids 120 to 408) linked to VP16 [GAL4-T3R(408)-VP16] is activated by unliganded receptor as well as by T3. In contrast, GAL4-T3R containing the amino acid 120 to 408 ligand-binding region without the VP16 domain is activated only by T3. The highly conserved ninth heptad, which is involved in heterodimerization, appears to participate in the receptor-inhibitor interaction, suggesting that the inhibitor is a related member of the receptor gene family. In striking contrast to T3R and RAR, RXR activates GAL4-T3R-VP16 only with its ligand, 9-cis RA, but unliganded RXR does not appear to be the inhibitor suggested by these studies. Further evidence that an orphan receptor may be the inhibitor comes from our finding that COUP-TF inhibits activation of GAL4-T3R-VP16 by unliganded T3R and the activation of GAL4-T3R by T3. These and other results suggest that an inhibitory factor

  1. All-Trans-Retinoic Acid Improves Cholestasis in α-Naphthylisothiocyanate–Treated Rats and Mdr2−/− Mice

    PubMed Central

    Mennone, Albert; Soroka, Carol J.

    2014-01-01

    Chronic cholestasis results in liver injury and eventually liver failure. Although ursodeoxycholic acid (UDCA) showed limited benefits in primary biliary cirrhosis, there is an urgent need to develop alternative therapy for chronic cholestatic disorders. Previous studies from our laboratory demonstrated that all-trans-retinoic acid (atRA) is a potent suppressor of CYP7A1, the rate-limiting enzyme in bile acid synthesis. atRA also repressed the expression of tumor growth factor-β and collagen 1A1 in activated primary human stellate cells and LX2 cells. When administered together with UDCA to bile duct–ligated rats, this combined therapy significantly reduced the bile acid pool size and improved liver conditions. To further examine whether atRA alone or in combination with UDCA has greater beneficial effects than UDCA treatment alone, we assessed this treatment in two additional chronic cholestatic rodent models: α-naphthylisothiocyanate (ANIT)–treated rats and the Mdr2−/− (Abcb4−/−) knockout mouse. atRA alone significantly reduced bile duct proliferation, inflammation, and hydroxyproline levels in ANIT-treated rats, whereas the combination of atRA and UDCA significantly reduced plasma bile salt level compared with UDCA treatment. atRA alone or in combination with UDCA significantly reduced plasma levels of alkaline phosphatase and bile salts in 12-week-old Mdr2−/− mice. Reduced bile duct proliferation and inflammation were also observed in the livers of these mice. Together, atRA alone or in combination with UDCA significantly reduced the severity of liver injury in these two animal models, further supporting the combination treatment of atRA and UDCA as a potential new therapy for patients with chronic cholestatic liver disease who have not responded fully to UDCA. PMID:24492652

  2. NPM and BRG1 Mediate Transcriptional Resistance to Retinoic Acid in Acute Promyelocytic Leukemia.

    PubMed

    Nichol, Jessica N; Galbraith, Matthew D; Kleinman, Claudia L; Espinosa, Joaquín M; Miller, Wilson H

    2016-03-29

    Perturbation in the transcriptional control of genes driving differentiation is an established paradigm whereby oncogenic fusion proteins promote leukemia. From a retinoic acid (RA)-sensitive acute promyelocytic leukemia (APL) cell line, we derived an RA-resistant clone characterized by a block in transcription initiation, despite maintaining wild-type PML/RARA expression. We uncovered an aberrant interaction among PML/RARA, nucleophosmin (NPM), and topoisomerase II beta (TOP2B). Surprisingly, RA stimulation in these cells results in enhanced chromatin association of the nucleosome remodeler BRG1. Inhibition of NPM or TOP2B abrogated BRG1 recruitment. Furthermore, NPM inhibition and targeting BRG1 restored differentiation when combined with RA. Here, we demonstrate a role for NPM and BRG1 in obstructing RA differentiation and implicate chromatin remodeling in mediating therapeutic resistance in malignancies. NPM mutations are the most common genetic change in patients with acute leukemia (AML); therefore, our model may be applicable to other more common leukemias driven by NPM.

  3. Interleukin-1 family members are enhanced in psoriasis and suppressed by vitamin D and retinoic acid.

    PubMed

    Balato, Anna; Schiattarella, Maria; Lembo, Serena; Mattii, Martina; Prevete, Nella; Balato, Nicola; Ayala, Fabio

    2013-04-01

    Interleukin (IL)-1 family comprise 11 members that play an important role in immune regulation and inflammatory process. Retinoids exert complex effects on the immune system, having anti-inflammatory effects in chronic dermatological diseases. Vitamin D (vitD) and analogs have been shown to suppress TNF-α-induced IL-1α in human keratinocytes (KCs). In the present study, we investigated IL-1 family members in psoriasis and the effects of vitD and retinoic acid (RA) on these members. We analyzed IL-1 family members gene expression in psoriatic skin and in ex vivo skin organ culture exposed to TNF-α, IL-17 or broadband UVB; afterwards, treatment with vitD or RA was performed and IL-1 family members mRNA was evaluated. Similarly, KCs were stimulated with IL-17 and subsequently treated with vitD. IL-1 family members were enhanced in psoriatic skin and in ex vivo skin organ cultures after pro-inflammatory stimuli (TNF-α, IL-17 and UVB). RA and vitD were able to suppress this enhancement.

  4. Retinoic acid signaling spatially restricts osteoblasts and controls ray-interray organization during zebrafish fin regeneration.

    PubMed

    Blum, Nicola; Begemann, Gerrit

    2015-09-01

    The zebrafish caudal fin consists of repeated units of bony rays separated by soft interray tissue, an organization that must be faithfully re-established during fin regeneration. How and why regenerating rays respect ray-interray boundaries, thus extending only the existing bone, has remained unresolved. Here, we demonstrate that a retinoic acid (RA)-degrading niche is established by Cyp26a1 in the proximal basal epidermal layer that orchestrates ray-interray organization by spatially restricting osteoblasts. Disruption of this niche causes preosteoblasts to ignore ray-interray boundaries and to invade neighboring interrays where they form ectopic bone. Concomitantly, non-osteoblastic blastema cells and regenerating blood vessels spread into the interrays, resulting in overall disruption of ray-interray organization and irreversible inhibition of fin regeneration. The cyp26a1-expressing niche plays another important role during subsequent regenerative outgrowth, where it facilitates the Shha-promoted proliferation of osteoblasts. Finally, we show that the previously observed distal shift of ray bifurcations in regenerating fins upon RA treatment or amputation close to the bifurcation can be explained by inappropriate preosteoblast alignment and does not necessarily require putative changes in proximodistal information. Our findings uncover a mechanism regulating preosteoblast alignment and maintenance of ray-interray boundaries during fin regeneration. PMID:26253402

  5. Retinoic acid negatively regulates dact3b expression in the hindbrain of zebrafish embryos

    PubMed Central

    Mandal, Amrita; Waxman, Joshua

    2014-01-01

    Wnt signaling plays important roles in normal development as well as pathophysiological conditions. The Dapper antagonist of β-catenin (Dact) proteins are modulators of both canonical and non-canonical Wnt signaling via direct interactions with Dishevelled (Dvl) and Van Gogh like-2 (Vangl2). Here, we report the dynamic expression patterns of two zebrafish dact3 paralogs during early embryonic development. Our whole mount in situ hybridization (WISH) analysis indicates that specific dact3a expression starts by the tailbud stage in adaxial cells. Later, it is expressed in the anterior lateral plate mesoderm, somites, migrating cranial neural crest, and hindbrain neurons. By comparison, dact3b expression initiates on the dorsal side at the dome stage and soon after is expressed in the dorsal forerunner cells (DFCs) during gastrulation. At later stages, dact3b expression becomes restricted to the branchial neurons of the hindbrain and to the 2nd pharyngeal arch. To investigate how zebrafish dact3 gene expression is regulated, we manipulated retinoic acid (RA) signaling during development and found it negatively regulates dact3b in the hindbrain. Our study is the first to document the expression of the paralogous zebrafish dact3 genes during early development and demonstrate dact3b can be regulated by RA signaling. Therefore, our study opens up new avenues to study Dact3 function in the development of multiple tissues and suggests a previously unappreciated cross regulation of Wnt signaling by RA signaling in the developing vertebrate hindbrain. PMID:25266145

  6. The meninges is a source of retinoic acid for the late-developing hindbrain.

    PubMed

    Zhang, Jinghua; Smith, Deborah; Yamamoto, Miyuki; Ma, Lanhua; McCaffery, Peter

    2003-08-20

    One general function for retinoic acid (RA) is pattern organization in the CNS. This regulatory factor has an essential role in spinal cord motor neuron and early posterior hindbrain development. In the anterior CNS, however, there is only a limited number of foci of RA synthesis, and less attention has been placed on regions such as the anterior hindbrain where RA synthesizing enzymes are absent. This study shows that a rich source of RA lies around the hindbrain from the RA synthetic enzyme retinaldehyde dehydrogenase-2 (RALDH2) present in the surrounding meninges and mesenchyme by embryonic day 13. RALDH2 is not distributed uniformly throughout the meninges but is restricted to territories over the developing hindbrain, suggesting that RA signaling may be localized to those regions. Further regulation of RA signaling is provided by the presence of a RA sink in the form of the CYP26B1 RA catabolic enzyme expressed in deeper regions of the brain. As a guide to the neural anatomy of hindbrain RA signaling, we used a mouse transgenic for a lacZ reporter gene driven by a RA response element (RAREhsplacZ) to identify regions of RA signaling. This reporter mouse provides evidence that RA signaling in the hindbrain after embryonic day 13 occurs in the regions of the cerebellum and precerebellar system adjacent to sources of RA, including the inferior olive and the pontine nuclei.

  7. Retinoic acid reverses the PTU related decrease in neurogranin level in mice brain.

    PubMed

    Enderlin, V; Vallortigara, J; Alfos, S; Féart, C; Pallet, V; Higueret, P

    2004-09-01

    Recent data have shown that fine regulation of retinoid mediated gene expression is fundamentally important for optimal brain functioning in aged mice. Nevertheless, alteration of the thyroid hormone signalling pathway may be a limiting factor, which impedes retinoic acid (RA) from exerting its modulating effect. Mild hypothyroidism is often described in the elderly. Thus, in the present study, it was of interest to determine if RA exerts its neurological modulating effect in mild hypothyroidism. To obtain further insight into this question, mice were submitted to a low propylthiouracyl (PTU) drink (0.05%) in order to slightly reduce the serum level of triiodothyronine (T3). A quantitative evaluation of RA nuclear receptors (RAR, RXR), T3 nuclear receptor (TR) and of neurogranin (RC3, a RA target gene which codes for a protein considered as a good marker of synaptic plasticity) in PTU treated mice injected with vehicle or RA or T3 was carried out. The PTU-related decrease in expression of RAR, RXR and RC3 was restored following RA or T3 administration, as observed in aged mice. The amount of TR mRNA, which was not affected in PTU treated mice, was increased only after T3 treatment as observed in overt hypothyroidism. These results suggest that neurobiological alterations observed in aged mice are probably related to RA and T3 signalling pathway modifications associated, in part, with mild changes in thyroid function.

  8. Roles of retinoic acid signaling in normal and abnormal development of the palate and tongue.

    PubMed

    Okano, Junko; Udagawa, Jun; Shiota, Kohei

    2014-05-01

    Palatogenesis involves various developmental events such as growth, elevation, elongation and fusion of opposing palatal shelves. Extrinsic factors such as mouth opening and subsequent tongue withdrawal are also needed for the horizontal elevation of palate shelves. Failure of any of these steps can lead to cleft palate, one of the most common birth defects in humans. It has been shown that retinoic acid (RA) plays important roles during palate development, but excess RA causes cleft palate in fetuses of both rodents and humans. Thus, the coordinated regulation of retinoid metabolism is essential for normal palatogenesis. The endogenous RA level is determined by the balance of RA-synthesizing (retinaldehyde dehydrogenases: RALDHs) and RA-degrading enzymes (CYP26s). Cyp26b1 is a key player in normal palatogenesis. In this review, we discuss recent progress in the study of the pathogenesis of RA-induced cleft palate, with special reference to the regulation of endogenous RA levels by RA-degrading enzymes.

  9. 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

  10. Synergistic effects of retinoic acid and tamoxifen on human breast cancer cells: Proteomic characterization

    SciTech Connect

    Wang Ying; He Qingyu; Chen Hongming; Chiu Jenfu . E-mail: jfchiu@hkucc.hku.hk

    2007-01-15

    The anti-estrogen tamoxifen and vitamin A-related compound, all-trans retinoic acid (RA), in combination act synergistically to inhibit the growth of MCF-7 human breast cancer cells. In the present study, we applied two-dimensional gel electrophoresis based proteomic approach to globally analyze this synergistic effect of RA and tamoxifen. Proteomic study revealed that multiple clusters of proteins were involved in RA and tamoxifen-induced apoptosis in MCF-7 breast cancer cells, including post-transcriptional and splicing factors, proteins related to cellular proliferation or differentiation, and proteins related to energy production and internal degradation systems. The negative growth factor-transforming growth factor {beta} (TGF{beta}) was secreted by RA and/or tamoxifen treatment and was studies as a potential mediator of the synergistic effects of RA and tamoxifen in apoptosis. By comparing protein alterations in treatments of RA and tamoxifen alone or in combination to those of TGF{beta} treatment, or co-treatment with TGF{beta} inhibitor SB 431542, proteomic results showed that a number of proteins were involved in TGF{beta} signaling pathway. These results provide valuable insights into the mechanisms of RA and tamoxifen-induced TGF{beta} signaling pathway in breast cancer cells.

  11. Interaction of ethanol with retinol and retinoic acid in RAR beta and GAP-43 expression.

    PubMed

    Grummer, M A; Zachman, R D

    2000-01-01

    Fetal ethanol exposure has many detrimental effects on neural development, which possibly occurs through ethanol-induced disruption of the function of vitamin A. In LAN-5 neuroblastoma cells, retinol (10(-6) M) and retinoic acid (RA; 10(-5)-10(-6) M) increased RAR beta mRNA expression. Ethanol downregulated RAR beta levels, even in the presence of retinol. RAR beta mRNA expression was decreased by ethanol in the presence of 10(-6) M RA, but not 10(-5) M RA. With cycloheximide (CX), RA still stimulated RAR beta mRNA, but the effect of ethanol was abolished. The mRNA expression of GAP-43, an important factor in neural development, increased with 10(-6) M retinol and 10(-5)-10(-9) M RA. Ethanol decreased GAP-43 mRNA expression in the presence or absence of retinol. Ethanol was without effect on GAP-43 mRNA at 10(-5) M RA, but did lower the levels at 10(-6) and 10(-7) M RA. CX prevented the effects of both RA and ethanol on GAP-43 mRNA. These studies provide support for the hypothesis that retinoid function is altered by ethanol. PMID:11120388

  12. Sox9b is a mediator of retinoic acid signaling restricting endocrine progenitor differentiation.

    PubMed

    Huang, Wei; Beer, Rebecca L; Delaspre, Fabien; Wang, Guangliang; Edelman, Hannah E; Park, Hyewon; Azuma, Mizuki; Parsons, Michael J

    2016-10-01

    Centroacinar cells (CACs) are ductal Notch-responsive progenitors that in the larval zebrafish pancreas differentiate to form new islets and ultimately contribute to the majority of the adult endocrine mass. Uncovering the mechanisms regulating CAC differentiation will facilitate understanding how insulin-producing β cells are formed. Previously we reported retinoic acid (RA) signaling and Notch signaling both regulate larval CAC differentiation, suggesting a shared downstream intermediate. Sox9b is a transcription factor important for islet formation whose expression is upregulated by Notch signaling in larval CACs. Here we report that sox9b expression in larval CACs is also regulated by RA signaling. Therefore, we hypothesized that Sox9b is an intermediate between both RA- and Notch-signaling pathways. In order to study the role of Sox9b in larval CACs, we generated two cre/lox based transgenic tools, which allowed us to express full-length or truncated Sox9b in larval CACs. In this way we were able to perform spatiotemporal-controlled Sox9b gain- and loss-of-function studies and observe the subsequent effect on progenitor differentiation. Our results are consistent with Sox9b regulating CAC differentiation by being a downstream intermediate of both RA- and Notch-signaling pathways. We also demonstrate that adult zebrafish with only one functional allele of sox9b undergo accelerated β-cell regeneration, an observation consistent with sox9b regulating CAC differentiation in adults. PMID:27565026

  13. Dexamethasone, all trans retinoic acid and interferon alpha 2a in patients with refractory multiple myeloma.

    PubMed

    Avilés, A; Rosas, A; Huerta-Guzmán, J; Talavera, A; Cleto, S

    1999-02-01

    Few effective regimen are available for patients with refractory multiple myeloma (RMM). Generally, responses are scarce and disease free survival is very short. We developed a new therapeutic option in these patients using dexamethasone (40 mg/m2, i.v., daily, days 1 to 4), all-trans retinoic acid (45 mg/m2, po, daily, days 5 to 14) and interferon alpha 2a (9.0 MU, daily, subcutaneously, days 5 to 14). The treatment was administered every 21 days for 6 cycles. In a pilot study, 12 patients, heavily treated with chemotherapy and radiotherapy and in some cases with interferon, were allocated to receive the afore mentioned treatment. Response was observed in 10 patients (83%). With a median follow-up of 36.1 months (range 27 to 41), seven patients remain alive and disease-free without any treatment. Two patients were failures and have died due to tumor progression. Toxicity was mild and all patients received treatment according to the planned doses of drugs. The use of biological modifiers in combination with dexamethasone offer a safe and effective therapeutic option in patients with refractory multiple myeloma. More studies are warranted to define the role of this type of treatment.

  14. The Influence of 13-cis Retinoic Acid on Human Meibomian Gland Epithelial Cells

    PubMed Central

    Ding, Juan; Kam, Wendy R.; Dieckow, Julia; Sullivan, David A.

    2013-01-01

    Purpose. Meibomian gland dysfunction (MGD) is a primary cause of dry eye disease. One of the risk factors for MGD is exposure to 13-cis retinoic acid (13-cis RA), a metabolite of vitamin A. However, the mechanism is not well understood. We hypothesize that 13-cis RA inhibits cell proliferation, promotes cell death, alters gene and protein expressions, and attenuates cell survival pathways in human meibomian gland epithelial cells. Methods. To test our hypotheses, immortalized human meibomian gland epithelial cells were cultured with or without 13-cis RA for varying doses and time. Cell proliferation, cell death, gene expression, and proteins involved in proliferation/survival and inflammation were evaluated. Results. We found that 13-cis RA inhibited cell proliferation, induced cell death, and significantly altered the expression of 6726 genes, including those involved in cell proliferation, cell death, differentiation, keratinization, and inflammation, in human meibomian gland epithelial cells. Further, 13-cis RA also reduced the phosphorylation of Akt and increased the generation of interleukin-1β and matrix metallopeptidase 9. Conclusions. Exposure to 13-cis RA inhibits cell proliferation, increases cell death, alters gene expression, changes signaling pathways, and promotes inflammatory mediator and protease expression in meibomian gland epithelial cells. These effects may be responsible, at least in part, for the 13-cis RA–related induction of MGD. PMID:23722388

  15. Ligand regulation of retinoic acid receptor-related orphan receptors: implications for development of novel therapeutics

    PubMed Central

    Solt, Laura A.; Griffin, Patrick R.; Burris, Thomas P.

    2016-01-01

    Purpose of review In the late 1980s, the cloning of several nuclear receptors led to the intense search and isolation of new members of this superfamily. Despite their identification, many of these receptors were dubbed ‘orphan’ receptors, as their physiological ligands remained unknown. Recent reports have presented evidence for one family of orphan receptors, the retinoic acid receptor-related orphan receptors (RORs), in several pathologies, including osteoporosis, several autoimmune diseases, asthma, cancer, diabetes and obesity. The present review summarizes the studies identifying ligands for the RORs and evaluates their role as targets for potential therapeutics. Recent findings Significant progress was made in the initial identification of ligands for the RORs when X-ray crystallographic studies identified several molecules within the ligand-binding pockets of RORα and RORβ. Recently, we identified endogenous and synthetic ligands for RORα and RORγ, thereby solidifying their function as ligand-dependent transcription factors. Summary Recent studies have established roles for the RORs in physiological development and the advent of disease. Identification of ligands for the RORs, both endogenous and synthetic, has established these receptors as attractive new therapeutic targets for the treatment of ROR-related diseases. PMID:20463469

  16. Nuclear receptors for retinoic acid and thyroid hormone regulate transcription of keratin genes.

    PubMed Central

    Tomic, M; Jiang, C K; Epstein, H S; Freedberg, I M; Samuels, H H; Blumenberg, M

    1990-01-01

    In the epidermis, retinoids regulate the expression of keratins, the intermediate filament proteins of epithelial cells. We have cloned the 5' regulatory regions of four human epidermal keratin genes, K#5, K#6, K#10, and K#14, and engineered constructs in which these regions drive the expression of the CAT reporter gene. By co-transfecting the constructs into epithelial cells along with the vectors expressing nuclear receptors for retinoic acid (RA) and thyroid hormone, we have demonstrated that the receptors can suppress the promoters of keratin genes. The suppression is ligand dependent; it is evident both in established cell lines and in primary cultures of epithelial cells. The three RA receptors have similar effects on keratin gene transcription. Our data indicate that the nuclear receptors for RA and thyroid hormone regulate keratin synthesis by binding to negative recognition elements in the upstream DNA sequences of the keratin genes. RA thus has a twofold effect on epidermal keratin expression: qualitatively, it regulates the regulators that effect the switch from basal cell-specific keratins to differentiation-specific ones; and quantitatively, it determines the level of keratin synthesis within the cell by direct interaction of its receptors with the keratin gene promoters. Images PMID:1712634

  17. Cellular localization of retinoic acid receptor-gamma expression in normal and neoplastic skin.

    PubMed Central

    Finzi, E.; Blake, M. J.; Celano, P.; Skouge, J.; Diwan, R.

    1992-01-01

    Retinoids profoundly affect the normal growth and differentiation of epithelial tissues. Retinoic acid receptor-gamma (RAR-gamma) is a member of a family of retinoid receptors, and has been shown to be expressed almost exclusively in skin. However, little is known about the cellular localization of this receptor in human skin. The authors studied the expression of RAR-gamma in normal skin and human skin tumors by Northern blot analysis and in situ hybridization. RAR-gamma mRNA was detected in normal skin as well as in cultures of neonatal keratinocytes. Using an oligonucleotide specific for the RAR-gamma cDNA isoform 1 (RAR-gamma 1), RAR-gamma 1 mRNA was localized to all layers of the epidermis, the outer root sheath of hair follicles, follicular hair bulbs, eccrine and sebaceous glands. Basal cell carcinoma constitutively expressed gamma-1 mRNA and one of seven squamous cell carcinomas showed loss of gamma-1 mRNA expression, relative to adjacent epithelium. By contrast, normal melanocytic nevi and tumor-associated lymphocytes expressed little or no RAR-gamma mRNA. These results suggest that RAR-gamma 1 may play an important role in the maintenance and differentiation of normal epidermis and skin appendages. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:1318641

  18. Zebrafish fetal alcohol syndrome model: effects of ethanol are rescued by retinoic acid supplement.

    PubMed

    Marrs, James A; Clendenon, Sherry G; Ratcliffe, Don R; Fielding, Stephen M; Liu, Qin; Bosron, William F

    2010-01-01

    This study was designed to develop a zebrafish experimental model to examine defects in retinoic acid (RA) signaling caused by embryonic ethanol exposure. RA deficiency may be a causative factor leading to a spectrum of birth defects classified as fetal alcohol spectrum disorder (FASD). Experimental support for this hypothesis using Xenopus showed that effects of treatment with ethanol could be partially rescued by adding retinoids during ethanol treatment. Previous studies show that treating zebrafish embryos during gastrulation and somitogenesis stages with a pathophysiological concentration of ethanol (100mM) produces effects that are characteristic features of FASD. We found that treating zebrafish embryos with RA at a low concentration (10(-9)M) and 100mM ethanol during gastrulation and somitogenesis stages significantly rescued a spectrum of defects produced by treating embryos with 100mM ethanol alone. The rescued phenotype that we observed was quantitatively more similar to embryos treated with 10(-9)M RA alone (RA toxicity) than to untreated or 100mM ethanol-treated embryos. RA rescued defects caused by 100mM ethanol treatment during gastrulation and somitogenesis stages that include early gastrulation cell movements (anterior-posterior axis), craniofacial cartilage formation, and ear development. Morphological evidence also suggests that other characteristic features of FASD (e.g., neural axis patterning) are rescued by RA supplement.

  19. Retinoic acid treatment of fibroblasts causes a rapid decrease in ( sup 3 H)inositol uptake

    SciTech Connect

    Sinha, R.; Creek, K.E.; Silverman-Jones, C.; de Luca, L.M. )

    1989-04-01

    NIH 3T3 fibroblasts treated with all-trans-retinoic acid (RA) showed a dramatic decrease in the uptake of ({sup 3}H)inositol compared to solvent-treated controls. The onset of RA-induced inhibition of ({sup 3}H)inositol uptake was rapid with a 10-15% decrease occurring after 2-3 h of RA exposure and 60-70% reduction after 16 h of RA treatment. A progressive dose-dependent decrease in inositol uptake was found as the concentration of RA increased from 10{sup {minus}8} to 10{sup {minus}5} M and the effect was fully reversible within 48 h after RA removal. RA inhibition of inositol uptake was also observed in 3T3-Swiss and Balb/3T3 cells but not in two virally transformed 3T3 cell lines. Phlorizin, amiloride, and monensin inhibited inositol uptake by 66, 74, and 58%, respectively, and this inhibition was additive when the cells were treated with RA as well as these inhibitors. A decreased incorporation of ({sup 3}H)inositol into polyphosphoinositides was also observed in RA-treated cells but not to the same extent as for ({sup 3}H)inositol uptake. In conclusion, RA treatment of 3T3 fibroblasts decreases the uptake of ({sup 3}H)inositol by up to 70% within 8 to 10 h at near physiological concentrations in a reversible and specific manner.

  20. Maternal diabetes increases the risk of caudal regression caused by retinoic acid.

    PubMed

    Chan, Billy W H; Chan, Kwok-Siu; Koide, Tsuyoshi; Yeung, Sau-Man; Leung, Maran B W; Copp, Andrew J; Loeken, Mary R; Shiroishi, Toshihiko; Shum, Alisa S W

    2002-09-01

    Maternal diabetes increases the risk of congenital malformations in the offspring of affected pregnancies. This increase arises from the teratogenic effect of the maternal diabetic milieu on the developing embryo, although the mechanism of this action is poorly understood. In the present study, we examined whether the vitamin A metabolite retinoic acid (RA), a common drug with well-known teratogenic properties, may interact with maternal diabetes to alter the incidence of congenital malformations in mice. Our results show that when treated with RA, embryos of diabetic mice are significantly more prone than embryos of nondiabetic mice to develop caudal regression, a defect that is highly associated with diabetic pregnancy in humans. By studying the vestigial tail (Wnt-3a(vt)) mutant, we provide evidence that Wnt-3a, a gene that controls the development of the caudal region, is directly involved in the pathogenic pathway of RA-induced caudal regression. We further show that the molecular basis of the increased susceptibility of embryos of diabetic mice to RA involves enhanced downregulation of Wnt-3a expression. This positive interaction between RA and maternal diabetes may have implications for humans in suggesting increased susceptibility to environmental teratogens during diabetic pregnancy.

  1. Dexamethasone, all trans retinoic acid and interferon alpha 2a in patients with refractory multiple myeloma.

    PubMed

    Avilés, A; Rosas, A; Huerta-Guzmán, J; Talavera, A; Cleto, S

    1999-02-01

    Few effective regimen are available for patients with refractory multiple myeloma (RMM). Generally, responses are scarce and disease free survival is very short. We developed a new therapeutic option in these patients using dexamethasone (40 mg/m2, i.v., daily, days 1 to 4), all-trans retinoic acid (45 mg/m2, po, daily, days 5 to 14) and interferon alpha 2a (9.0 MU, daily, subcutaneously, days 5 to 14). The treatment was administered every 21 days for 6 cycles. In a pilot study, 12 patients, heavily treated with chemotherapy and radiotherapy and in some cases with interferon, were allocated to receive the afore mentioned treatment. Response was observed in 10 patients (83%). With a median follow-up of 36.1 months (range 27 to 41), seven patients remain alive and disease-free without any treatment. Two patients were failures and have died due to tumor progression. Toxicity was mild and all patients received treatment according to the planned doses of drugs. The use of biological modifiers in combination with dexamethasone offer a safe and effective therapeutic option in patients with refractory multiple myeloma. More studies are warranted to define the role of this type of treatment. PMID:10850283

  2. Retinoic acid influences the development of the inferior olivary nucleus in the rodent.

    PubMed

    Yamamoto, Miyuki; Fujinuma, Masahiro; Hirano, Shinji; Hayakawa, Yoshika; Clagett-Dame, Margaret; Zhang, Jinghua; McCaffery, Peter

    2005-04-15

    All-trans retinoic acid (atRA) is an endogenous morphogen that regulates gene transcription. Maternal exposure to atRA results in severe developmental abnormalities by disrupting normal patterns of atRA distribution. Previously, we have shown that the pontine nucleus, which originates from the rhombic lip, is severely atrophied in the mouse on exposure to atRA at gestational days 9 and 10. In this study, we show that this same period of atRA exposure has the contrary effect on the inferior olive and this rhombic lip derivative is expanded in volume and probably contains an increased number of cells. The posterior region of the inferior olive maintains a relatively normal shape but is significantly expanded in size. In contrast, the organization of the anterior inferior olive is severely disrupted. Because endogenous atRA levels are known to be higher in the region of the posterior inferior olive at the time of birth of inferior olivary neurons, these results suggest that endogenous atRA may promote the generation, or select the fate, of posterior neurons of the inferior olive. In support of this concept, a reduction in atRA resulting from vitamin A deficiency results in loss of cells of the posterior inferior olive.

  3. All-trans retinoic acid induces oxidative phosphorylation and mitochondria biogenesis in adipocytes.

    PubMed

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

    2015-06-01

    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.

  4. Retinoic acid differentially regulates the migration of innate lymphoid cell subsets to the gut

    PubMed Central

    Kim, Myung H.; Taparowsky, Elizabeth J.; Kim, Chang H.

    2015-01-01

    Summary Distinct groups of innate lymphoid cells (ILCs) such as ILC1, ILC2 and ILC3 populate the intestine, but how these ILCs develop tissue tropism for this organ is unclear. We report that prior to migration to the intestine ILCs first undergo a `switch' in their expression of homing receptors from lymphoid to gut homing receptors. This process is regulated by mucosal dendritic cells and the gut-specific tissue factor retinoic acid (RA). This change in homing receptors is required for long-term population and effector function of ILCs in the intestine. Only ILC1 and ILC3, but not ILC2, undergo the RA-dependent homing receptor switch in gut-associated lymphoid tissues. In contrast, ILC2 acquire gut homing receptors in a largely RA-independent manner during their development in the bone marrow and can migrate directly to the intestine. Thus, distinct programs regulate the migration of ILC subsets to the intestine for regulation of innate immunity. PMID:26141583

  5. Retinoic acid induces multiple hallmarks of the prospermatogonia-to-spermatogonia transition in the neonatal mouse.

    PubMed

    Busada, Jonathan T; Kaye, Evelyn P; Renegar, Randall H; Geyer, Christopher B

    2014-03-01

    In mammals, most neonatal male germ cells (prospermatogonia) are quiescent and located in the center of the testis cords. In response to an unknown signal, prospermatogonia transition into spermatogonia, reenter the cell cycle, divide, and move to the periphery of the testis cords. In mice, these events occur by 3-4 days postpartum (dpp), which temporally coincides with the onset of retinoic acid (RA) signaling in the neonatal testis. RA has a pivotal role in initiating germ cell entry into meiosis in both sexes, yet little is known about the mechanisms and about cellular changes downstream of RA signaling. We examined the role of RA in mediating the prospermatogonia-to-spermatogonia transition in vivo and found 24 h of precocious RA exposure-induced germ cell changes mimicking those that occur during the endogenous transition at 3-4 dpp. These changes included: 1) spermatogonia proliferation; 2) maturation of cellular organelles; and 3), expression of markers characteristic of differentiating spermatogonia. We found that germ cell exposure to RA did not lead to cellular loss from apoptosis but rather resulted in a delay of ∼2 days in their entry into meiosis. Taken together, our results indicate that exogenous RA induces multiple hallmarks of the transition of prospermatogonia to spermatogonia prior to their entry into meiosis.

  6. Expression and retinoic acid regulation of the zebrafish nr2f orphan nuclear receptor genes

    PubMed Central

    Love, Crystal E.; Prince, Victoria E.

    2012-01-01

    Background The vertebrate nuclear receptor subfamily 2, group f (nr2f) genes encode orphan receptors that have the capacity to act as negative regulators of retinoic acid (RA) signaling. Results We describe embryonic and larval expression of four of the six zebrafish nr2f genes, nr2f1a, nr2f1b, nr2f2 and nr2f5. These genes show highly regulated patterns of expression within the CNS, including in the developing hindbrain, as well as in the mesoderm and endoderm. We also investigated the role of RA and Fgf signaling in regulating early nr2f gene expression. RA is not required for nr2f expression in the hindbrain; however, exogenous RA can repress this expression. Conversely, we find that RA positively regulates nr2f1a expression in trunk endoderm and mesoderm. Fgf signaling is not required for nr2f expression onset in the hindbrain; however, it may play a role in maintaining rhombomere-specific expression. Conclusions We report detailed expression analysis of four nr2f genes in all three germ layers. The onset of nr2f expression in the hindbrain does not require RA or Fgf signals. Our finding that RA positively regulates nr2f1a expression in the trunk supports the possibility that Nr2fs function in a negative feedback loop to modulate RA signaling in this region. PMID:22836912

  7. Cancer procoagulant in the human promyelocytic cell line NB4 and its modulation by all-trans-retinoic acid.

    PubMed

    Falanga, A; Consonni, R; Marchetti, M; Mielicki, W P; Rambaldi, A; Lanotte, M; Gordon, S G; Barbui, T

    1994-01-01

    Acute promyelocytic leukemia (APL) cells express different types of procoagulant activity (PCA), including tissue factor (TF), and cancer procoagulant (CP). The aim of this study was to investigate whether the NB4 cell line, the first ever isolated human APL line, with the typical t(15;17) chromosomal balance translocation, possess CP as well as the cells freshly isolated from APL patients. Secondly, since the NB4 line is maturation inducible by all-trans-retinoic acid (ATRA), we wanted to verify whether CP, if present, was affected by ATRA treatment. The NB4 cells were able to shorten the recalcification assay of normal human plasma (total PCA). To distinguish CP in the assay for clotting activity, two criteria were used, the independence from factor VII to trigger blood coagulation and the sensitivity to cysteine proteinase inhibitors. Forty-seven per cent of total PCA of cell extracts was found to be FVII-independent PCA. A similar proportion of FVII-independent activity (42%) was detected in the cell serum-free supernatants. The activity was significantly decreased by cysteine proteinase inhibitors, including HgCl2, lodoacetic acid and Z-Ala-AlaCHN2. Additionally CP was directly identified and quantified by an immunocapture enzyme assay. The mean +/- SD concentration of CP detected by this assay in the NB4 cells, before any treatment, was 1.89 +/- 0.5 microgram/mg protein. Treatment of NB4 cells with 10(-6) M ATRA for 5 days significantly decreased the expression of CP, which became virtually undetectable by the clotting assay, and was 64% less than the untreated control by the immunocapture enzyme assay. This study provides the first evidence that the human promyelocytic cell line NB4 possess CP. The expression of this procoagulant is modulated by ATRA.

  8. Role of nitric oxide in the anti-tumoral effect of retinoic acid and 1,25-dihydroxyvitamin D3 on human promonocytic leukemic cells.

    PubMed

    Dugas, N; Mossalayi, M D; Calenda, A; Léotard, A; Bécherel, P; Mentz, F; Ouaaz, F; Arock, M; Debré, P; Dornand, J; Dugas, B

    1996-11-01

    All trans retinoic acid and vitamin D3 derivatives are well known for their antileukemic activity, while the precise mechanism of this effect remains to be clarified. Using human leukemic U937 and THP-1 promonocytic cell lines, we analyzed the effect of all-trans retinoic acid (RA) and/or 1,25-dihydroxyvitamin D3 (VD) on the generation of nitric oxide (NO), a potent antitumoral mediator. U937 cell differentiation with VD or with both RA and VD (RA/VD) correlated with gene transcription and functional expression of inducible nitric oxide synthase (iNOS). Nitrites and L-citrulline were also detected in U937 cell supernatants as soon as 24 hours following cell incubation with VD or RA/VD, but not in cells treated with RA alone. Inhibition of iNOS activity by NG-monomethyl-L-arginine (LNMMA) significantly decreased in vitro U937 cell differentiation with VD and RA/VD as shown by the expression of cell differentiation markers (CD14 and CD68) and by the capacity of these cells to undergo a luminol-dependent chemiluminescence in response to opsonized zymosan. Similar results were obtained using the THP-1 cell line strengthening the role of NO in the VD- and RA/VD-induced growth arrest and terminal differentiation of promonocytic leukemia cells.

  9. Identification of Tazarotenic Acid as the First Xenobiotic Substrate of Human Retinoic Acid Hydroxylase CYP26A1 and CYP26B1.

    PubMed

    Foti, Robert S; Isoherranen, Nina; Zelter, Alex; Dickmann, Leslie J; Buttrick, Brian R; Diaz, Philippe; Douguet, Dominique

    2016-05-01

    Cytochrome P450 (CYP) 26A1 and 26B1 are heme-containing enzymes responsible for metabolizing all-trans retinoic acid (at-RA). No crystal structures have been solved, and therefore homology models that provide structural information are extremely valuable for the development of inhibitors of cytochrome P450 family 26 (CYP26). The objectives of this study were to use homology models of CYP26A1 and CYP26B1 to characterize substrate binding characteristics, to compare structural aspects of their active sites, and to support the role of CYP26 in the metabolism of xenobiotics. Each model was verified by dockingat-RA in the active site and comparing the results to known metabolic profiles ofat-RA. The models were then used to predict the metabolic sites of tazarotenic acid with results verified by in vitro metabolite identification experiments. The CYP26A1 and CYP26B1 homology models predicted that the benzothiopyranyl moiety of tazarotenic acid would be oriented toward the heme of each enzyme and suggested that tazarotenic acid would be a substrate of CYP26A1 and CYP26B1. Metabolite identification experiments indicated that CYP26A1 and CYP26B1 oxidatively metabolized tazarotenic acid on the predicted moiety, with in vitro rates of metabolite formation by CYP26A1 and CYP26B1 being the highest across a panel of enzymes. Molecular analysis of the active sites estimated the active-site volumes of CYP26A1 and CYP26B1 to be 918 Å(3)and 977 Å(3), respectively. Overall, the homology models presented herein describe the enzyme characteristics leading to the metabolism of tazarotenic acid by CYP26A1 and CYP26B1 and support a potential role for the CYP26 enzymes in the metabolism of xenobiotics. PMID:26937021

  10. Lactoferrin Combined with Retinoic Acid Stimulates B1 Cells to Express IgA Isotype and Gut-homing Molecules.

    PubMed

    Kang, Seong-Ho; Jin, Bo-Ra; Kim, Hyeon-Jin; Seo, Goo-Young; Jang, Young-Saeng; Kim, Sun-Jin; An, Sun-Jin; Park, Seok-Rae; Kim, Woan-Sub; Kim, Pyeung-Hyeun

    2015-02-01

    It is well established that TGF-β1 and retinoic acid (RA) cause IgA isotype switching in mice. We recently found that lactoferrin (LF) also has an activity of IgA isotype switching in spleen B cells. The present study explored the effect of LF on the Ig production by mouse peritoneal B cells. LF, like TGF-β1, substantially increased IgA production in peritoneal B1 cells but little in peritoneal B2 cells. In contrast, LF increased IgG2b production in peritoneal B2 cells much more strongly than in peritoneal B1 cells. LF in combination with RA further enhanced the IgA production and, interestingly, this enhancement was restricted to IgA isotype and B1 cells. Similarly, the combination of the two molecules also led to expression of gut homing molecules α4β7 and CCR9 on peritoneal B1 cells, but not on peritoneal B2 cells. Thus, these results indicate that LF and RA can contribute to gut IgA response through stimulating IgA isotype switching and expression of gut-homing molecules in peritoneal B1 cells.

  11. Phenotypic chemical screening using a zebrafish neural crest EMT reporter identifies retinoic acid as an inhibitor of epithelial morphogenesis.

    PubMed

    Jimenez, Laura; Wang, Jindong; Morrison, Monique A; Whatcott, Clifford; Soh, Katherine K; Warner, Steven; Bearss, David; Jette, Cicely A; Stewart, Rodney A

    2016-04-01

    The epithelial-to-mesenchymal transition (EMT) is a highly conserved morphogenetic program essential for embryogenesis, regeneration and cancer metastasis. In cancer cells, EMT also triggers cellular reprogramming and chemoresistance, which underlie disease relapse and decreased survival. Hence, identifying compounds that block EMT is essential to prevent or eradicate disseminated tumor cells. Here, we establish a whole-animal-based EMT reporter in zebrafish for rapid drug screening, calledTg(snai1b:GFP), which labels epithelial cells undergoing EMT to producesox10-positive neural crest (NC) cells. Time-lapse and lineage analysis ofTg(snai1b:GFP)embryos reveal that cranial NC cells delaminate from two regions: an early population delaminates adjacent to the neural plate, whereas a later population delaminates from within the dorsal neural tube. TreatingTg(snai1b:GFP)embryos with candidate small-molecule EMT-inhibiting compounds identified TP-0903, a multi-kinase inhibitor that blocked cranial NC cell delamination in both the lateral and medial populations. RNA sequencing (RNA-Seq) analysis and chemical rescue experiments show that TP-0903 acts through stimulating retinoic acid (RA) biosynthesis and RA-dependent transcription. These studies identify TP-0903 as a new therapeutic for activating RAin vivoand raise the possibility that RA-dependent inhibition of EMT contributes to its prior success in eliminating disseminated cancer cells. PMID:26794130

  12. Phenotypic chemical screening using a zebrafish neural crest EMT reporter identifies retinoic acid as an inhibitor of epithelial morphogenesis.

    PubMed

    Jimenez, Laura; Wang, Jindong; Morrison, Monique A; Whatcott, Clifford; Soh, Katherine K; Warner, Steven; Bearss, David; Jette, Cicely A; Stewart, Rodney A

    2016-04-01

    The epithelial-to-mesenchymal transition (EMT) is a highly conserved morphogenetic program essential for embryogenesis, regeneration and cancer metastasis. In cancer cells, EMT also triggers cellular reprogramming and chemoresistance, which underlie disease relapse and decreased survival. Hence, identifying compounds that block EMT is essential to prevent or eradicate disseminated tumor cells. Here, we establish a whole-animal-based EMT reporter in zebrafish for rapid drug screening, calledTg(snai1b:GFP), which labels epithelial cells undergoing EMT to producesox10-positive neural crest (NC) cells. Time-lapse and lineage analysis ofTg(snai1b:GFP)embryos reveal that cranial NC cells delaminate from two regions: an early population delaminates adjacent to the neural plate, whereas a later population delaminates from within the dorsal neural tube. TreatingTg(snai1b:GFP)embryos with candidate small-molecule EMT-inhibiting compounds identified TP-0903, a multi-kinase inhibitor that blocked cranial NC cell delamination in both the lateral and medial populations. RNA sequencing (RNA-Seq) analysis and chemical rescue experiments show that TP-0903 acts through stimulating retinoic acid (RA) biosynthesis and RA-dependent transcription. These studies identify TP-0903 as a new therapeutic for activating RAin vivoand raise the possibility that RA-dependent inhibition of EMT contributes to its prior success in eliminating disseminated cancer cells.

  13. 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

  14. Normalizing Microbiota-Induced Retinoic Acid Deficiency Stimulates Protective CD8(+) T Cell-Mediated Immunity in Colorectal Cancer.

    PubMed

    Bhattacharya, Nupur; Yuan, Robert; Prestwood, Tyler R; Penny, Hweixian Leong; DiMaio, Michael A; Reticker-Flynn, Nathan E; Krois, Charles R; Kenkel, Justin A; Pham, Tho D; Carmi, Yaron; Tolentino, Lorna; Choi, Okmi; Hulett, Reyna; Wang, Jinshan; Winer, Daniel A; Napoli, Joseph L; Engleman, Edgar G

    2016-09-20

    Although all-trans-retinoic acid (atRA) is a key regulator of intestinal immunity, its role in colorectal cancer (CRC) is unknown. We found that mice with colitis-associated CRC had a marked deficiency in colonic atRA due to alterations in atRA metabolism mediated by microbiota-induced intestinal inflammation. Human ulcerative colitis (UC), UC-associated CRC, and sporadic CRC specimens have similar alterations in atRA metabolic enzymes, consistent with reduced colonic atRA. Inhibition of atRA signaling promoted tumorigenesis, whereas atRA supplementation reduced tumor burden. The benefit of atRA treatment was mediated by cytotoxic CD8(+) T cells, which were activated due to MHCI upregulation on tumor cells. Consistent with these findings, increased colonic expression of the atRA-catabolizing enzyme, CYP26A1, correlated with reduced frequencies of tumoral cytotoxic CD8(+) T cells and with worse disease prognosis in human CRC. These results reveal a mechanism by which microbiota drive colon carcinogenesis and highlight atRA metabolism as a therapeutic target for CRC.

  15. Retinoic acid regulates Schwann cell migration via NEDD9 induction by transcriptional and post-translational mechanisms.

    PubMed

    Latasa, Maria-Jesus; Jiménez-Lara, Ana María; Cosgaya, Jose Miguel

    2016-07-01

    Schwann cell migration is essential during the regenerative response to nerve injury, however, the factors that regulate this phenomenon are not yet clear. Here we describe that retinoic acid (RA), whose production and signaling activity are greatly enhanced during nerve regeneration, increases Schwann cell migration. This is accompanied by the up-regulation of NEDD9, a member of the CAS family of scaffold proteins previously implicated in migratory and invasive behavior in gliomas, melanomas and the neural crest cells from which Schwann cells derive. This RA-induced NEDD9 accumulation is due to augmented mRNA levels, as well as an increase of NEDD9 protein stability. Although all NEDD9 phospho-isoforms present in Schwann cells are induced by the retinoid, the hormone also changes its phosphorylation status, thus altering the ratio between the different isoforms. Silencing NEDD9 in Schwann cells had no effect on basal migratory ability, but completely abrogated RA-induced enhanced migration. Collectively, our results indicate that RA could be a major regulator of Schwann cell migration after nerve injury, thus offering a new insight into peripheral nerve repair. PMID:27085739

  16. Stra6, a retinoic acid-responsive gene, participates in p53-induced apoptosis after DNA damage

    PubMed Central

    Carrera, S; Cuadrado-Castano, S; Samuel, J; Jones, G D D; Villar, E; Lee, S W; Macip, S

    2013-01-01

    Stra6 is the retinoic acid (RA)-inducible gene encoding the cellular receptor for holo-retinol binding protein. This transmembrane protein mediates the internalization of retinol, which then upregulates RA-responsive genes in target cells. Here, we show that Stra6 can be upregulated by DNA damage in a p53-dependent manner, and it has an important role in cell death responses. Stra6 expression induced significant amounts of apoptosis in normal and cancer cells, and it was also able to influence p53-mediated cell fate decisions by turning an initial arrest response into cell death. Moreover, inhibition of Stra6 severely compromised p53-induced apoptosis. We also found that Stra6 induced mitochondria depolarization and accumulation of reactive oxygen species, and that it was present not only at the cellular membrane but also in the cytosol. Finally, we show that these novel functions of Stra6 did not require downstream activation of RA signalling. Our results present a previously unknown link between the RA and p53 pathways and provide a rationale to use retinoids to upregulate Stra6, and thus enhance the tumour suppressor functions of p53. This may have implications for the role of vitamin A metabolites in cancer prevention and treatment. PMID:23449393

  17. First Chemical Feature Based Pharmacophore Modeling of Potent Retinoidal Retinoic Acid Metabolism Blocking Agents (RAMBAs): Identification of Novel RAMBA Scaffolds

    PubMed Central

    Purushottamachar, Puranik; Patel, Jyoti B.; Gediya, Lalji K; Clement, Omoshile O.; Njar, Vincent C. O.

    2011-01-01

    The first three-dimensional (3D) pharmacophore model was developed for potent retinoidal retinoic acid metabolism blocking agents (RAMBAs) with IC50 values ranging from 0.0009 to 5.84 nM. The seven common chemical features in these RAMBAs as deduced by the Catalyst/HipHop program include five hydrophobic groups (hydrophobes), one hydrogen bond acceptor (HBA) and one ring aromatic group. Using the pharmacophore model as a 3D search query against NCI and Maybridge conformational Catalyst formatted databases; we retrieved several compounds with different structures (scaffolds) as hits. Twenty one retrieved hits were tested for RAMBA activity at 100 nM concentration. The most potent of these compounds, NCI10308597 and HTS01914 showed inhibitory potencies less (54.7% and 53.2%, respectively, at 100 nM) than those of our best previously reported RAMBAs VN/12-1 and VN/14-1 (90% and 86%, respectively, at 100 nM). Docking studies using a CYP26A1 homology model revealed that our most potent RAMBAs showed similar binding to the one observed for a series of RAMBAs reported previously by others. Our data shows the potential of our pharmacophore model in identifying structurally diverse and potent RAMBAs. Further refinement of the model and searches of other robust databases is currently in progress with a view to identifying and optimizing new leads. PMID:22130607

  18. Normalizing Microbiota-Induced Retinoic Acid Deficiency Stimulates Protective CD8(+) T Cell-Mediated Immunity in Colorectal Cancer.

    PubMed

    Bhattacharya, Nupur; Yuan, Robert; Prestwood, Tyler R; Penny, Hweixian Leong; DiMaio, Michael A; Reticker-Flynn, Nathan E; Krois, Charles R; Kenkel, Justin A; Pham, Tho D; Carmi, Yaron; Tolentino, Lorna; Choi, Okmi; Hulett, Reyna; Wang, Jinshan; Winer, Daniel A; Napoli, Joseph L; Engleman, Edgar G

    2016-09-20

    Although all-trans-retinoic acid (atRA) is a key regulator of intestinal immunity, its role in colorectal cancer (CRC) is unknown. We found that mice with colitis-associated CRC had a marked deficiency in colonic atRA due to alterations in atRA metabolism mediated by microbiota-induced intestinal inflammation. Human ulcerative colitis (UC), UC-associated CRC, and sporadic CRC specimens have similar alterations in atRA metabolic enzymes, consistent with reduced colonic atRA. Inhibition of atRA signaling promoted tumorigenesis, whereas atRA supplementation reduced tumor burden. The benefit of atRA treatment was mediated by cytotoxic CD8(+) T cells, which were activated due to MHCI upregulation on tumor cells. Consistent with these findings, increased colonic expression of the atRA-catabolizing enzyme, CYP26A1, correlated with reduced frequencies of tumoral cytotoxic CD8(+) T cells and with worse disease prognosis in human CRC. These results reveal a mechanism by which microbiota drive colon carcinogenesis and highlight atRA metabolism as a therapeutic target for CRC. PMID:27590114

  19. Phenotypic chemical screening using a zebrafish neural crest EMT reporter identifies retinoic acid as an inhibitor of epithelial morphogenesis

    PubMed Central

    Jimenez, Laura; Wang, Jindong; Morrison, Monique A.; Whatcott, Clifford; Soh, Katherine K.; Warner, Steven; Bearss, David; Jette, Cicely A.; Stewart, Rodney A.

    2016-01-01

    ABSTRACT The epithelial-to-mesenchymal transition (EMT) is a highly conserved morphogenetic program essential for embryogenesis, regeneration and cancer metastasis. In cancer cells, EMT also triggers cellular reprogramming and chemoresistance, which underlie disease relapse and decreased survival. Hence, identifying compounds that block EMT is essential to prevent or eradicate disseminated tumor cells. Here, we establish a whole-animal-based EMT reporter in zebrafish for rapid drug screening, called Tg(snai1b:GFP), which labels epithelial cells undergoing EMT to produce sox10-positive neural crest (NC) cells. Time-lapse and lineage analysis of Tg(snai1b:GFP) embryos reveal that cranial NC cells delaminate from two regions: an early population delaminates adjacent to the neural plate, whereas a later population delaminates from within the dorsal neural tube. Treating Tg(snai1b:GFP) embryos with candidate small-molecule EMT-inhibiting compounds identified TP-0903, a multi-kinase inhibitor that blocked cranial NC cell delamination in both the lateral and medial populations. RNA sequencing (RNA-Seq) analysis and chemical rescue experiments show that TP-0903 acts through stimulating retinoic acid (RA) biosynthesis and RA-dependent transcription. These studies identify TP-0903 as a new therapeutic for activating RA in vivo and raise the possibility that RA-dependent inhibition of EMT contributes to its prior success in eliminating disseminated cancer cells. PMID:26794130

  20. Development and characterization of polymer-oil nanostructured carrier (PONC) for controlled delivery of all-trans retinoic acid (ATRA)

    NASA Astrophysics Data System (ADS)

    Narvekar, Mayuri M.

    The commonly used PLGA-based delivery systems are often limited by their inadequate drug loading and release properties. This study reports the integration of oil into PLGA to form the prototype of a hybrid drug carrier PONC. Our primary goal is to confer the key strength of lipid-based drug carriers, i.e. efficient encapsulation of lipophilic compounds, to a PLGA system without taking away its various useful qualities. The PONC were formulated by emulsification solvent evaporation technique, which were then characterized for particle size, encapsulation efficiency, drug release and anticancer efficacy. The ATRA loaded PONC showed excellent encapsulation efficiency and release kinetics. Even after surface functionalization with PEG , controlled drug release kinetics was maintained, with 88.5% of the encapsulated ATRA released from the PEG-PONC in a uniform manner over 120 hours. It also showed favorable physicochemical properties and serum stability. PEG-PONC has demonstrated substantially superior activity over the free ATRA in ovarian cancer cells that are non-responsive to the standard chemotherapy. The newly developed PEG-PONC significantly reduced the IC50 values (p<0.05) in the chemoresistant cells in both MTT and colony formation assays. Hence, this new ATRA-nanoformulation may offer promising means for the delivery of lipophilic compounds like all-trans retinoic acid to treat highly resistant ovarian cancer.

  1. Polymeric nanoparticles based on chitooligosaccharide as drug carriers for co-delivery of all-trans-retinoic acid and paclitaxel.

    PubMed

    Zhang, Jing; Han, Jian; Zhang, Xiuli; Jiang, Jing; Xu, Maolei; Zhang, Daolai; Han, Jingtian

    2015-09-20

    An amphiphilic all-trans-retinoic acid (ATRA)-chitooligosaccharide (RCOS) conjugate was synthesized to form self-assembled polymeric nanoparticles to facilitate the co-delivery of ATRA and paclitaxel (PTX). The blank RCOS nanoparticles possessed low hemolytic activity and cytotoxicity, and could efficiently load PTX with a drug loading of 22.2% and a high encapsulation efficiency of 71.3%. PTX-loaded RCOS nanoparticles displayed a higher cytotoxicity to HepG2 cells compared to PTX plus ATRA solution when corrected by the accumulated drug release. Cellular uptake profiles of RCOS nanoparticles were evaluated via confocal laser scanning microscope and flow cytometry with FITC as a fluorescent mark. The RCOS nanoparticles could be rapidly and continuously taken up by HepG2 cells via endocytosis and transported into the nucleus, and the uptake rates increased with particle concentration. These results revealed the promising potential of RCOS nanoparticles as drug carriers for co-delivery of ATRA and PTX or other hydrophobic therapeutic agents.

  2. Effects of all-trans retinoic acid and interferon alpha in peripheral neuroectodermal tumor cell cultures and xenografts.

    PubMed

    Rosolen, A; Favaretto, G; Masarotto, G; Cavazzana, A; Zanesco, L; Frascella, E

    1998-11-01

    Peripheral neuroectodermal tumors (PNET) have an unsatisfactory outcome when treated with standard approaches. Among novel treatments, the use of biological response modifiers has rarely been reported in this group of malignancies. We have previously demonstrated that both all-trans retinoic acid (ATRA) and interferon á (IFNá) can inhibit proliferation of human PNET cells and that ATRA can up-regulate IFNá receptor expression in vitro. In this study we evaluated the anti-tumor effects of ATRA and IFNá in PNET cells in vitro and in a human PNET xenograft model, using CHP100 cells. A synergistic inhibitory effect of ATRA and IFNá was observed on CHP100 cells in vitro. On the contrary, a significant inhibition of tumor growth was observed in mice treated with ATRA alone, whereas neither IFNá nor the combination of ATRA and IFNá, reached a statistically significant anti-tumor effect. Histologic examination of tumors revealed the presence of necrosis upon treatment with IFNá, whereas almost no necrosis, but a more differentiated morphology, confirmed by electron microscopy analysis, was associated with the ATRA containing treatments. Taken together these data show an in vitro and in vivo anti-tumor activity of ATRA in human PNET cells, although no synergism of ATRA and IFNá was observed in our xenograft model.

  3. Gambogic acid causes fin developmental defect in zebrafish embryo partially via retinoic acid signaling.

    PubMed

    Jiang, Ling-Ling; Li, Kang; Lin, Qing-Hua; Ren, Jian; He, Zhi-Heng; Li, Huan; Shen, Ning; Wei, Ping; Feng, Feng; He, Ming-Fang

    2016-08-01

    Gambogic acid (GA), the major active ingredient of gamboge, has been approved by the Chinese Food and Drug Administration for clinical trials in cancer patients due to its strong anticancer activity. However, our previous research showed that GA was teratogenic against zebrafish fin development. To explore the teratogenicity and the underlying mechanisms, zebrafish (Danio rerio) embryos were used. The morphological observations revealed that GA caused fin defects in zebrafish embryos in a concentration-dependent manner. The critical exposure time of GA to reveal teratogenicity was before 8 hpf (hours post fertilization). LC/MS/MS analysis revealed that a maximum bioconcentration of GA was occurred at 4 hpf. Q-PCR data showed that GA treatment resulted in significant inactivation of RA signaling which could be partially rescued by the exogenous supply of RA. These results indicate the potential teratogenicity of GA and provide evidence for a caution in its future clinic use.

  4. Retinoic acid induced myelomeningocele in fetal rats: characterization by histopathological analysis and magnetic resonance imaging.

    PubMed

    Danzer, E; Schwarz, U; Wehrli, S; Radu, A; Adzick, N S; Flake, A W

    2005-08-01

    The prevention of human neural tube defects by folic acid administration and the potential for fetal surgical intervention for myelomeningocele (MMC) have renewed interest in the molecular pathways and pathophysiology of spina bifida. Animal models for assessment of the early developmental biology and pathophysiology of this lesion are needed. The goal of this study was to develop and characterize a non-surgical rat model of MMC. Time-dated Sprague-Dawley rats were gavage fed different doses of retinoic acid (RA) dissolved in olive oil at E10 (maternal n = 55, fetal n = 505). Control animals received olive oil alone (maternal n = 20, fetal n = 265) or were untreated (maternal n = 5, fetal n = 63). Fetuses were analyzed by detailed histopathology and MRI. Overall, isolated MMC occurred in 60.7% (307/505) of RA-exposed fetuses and no controls. Histopathology confirmed the entire spectrum of severity observed in human MMC, ranging from exposure of the cord with intact neural elements to complete cord destruction. MRI of the brain of MMC fetuses confirmed structural changes similar to humans with Arnold-Chiari malformation, including downward displacement of the cerebellum to just above the foramen magnum and compression of the developing medulla into a small posterior fossa. In conclusion, the RA-induced rat model of MMC is developmentally and anatomically analogous to human MMC. This relatively efficient and cost-effective model of MMC should facilitate investigation of the developmental biology and pathophysiology of MMC, and may be useful for the evaluation of further strategies for prenatal treatment. PMID:15893307

  5. Retinoic acid and 1,25-dihydroxyvitamin D3 stimulate osteoclast formation by different mechanisms

    SciTech Connect

    Scheven, B.A.; Hamilton, N.J. )

    1990-01-01

    The effects of retinoic acid (RA) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on osteoclast formation were examined in intact fetal long bones of different ages/developmental stages maintained in organ culture using a chemically defined medium with or without the presence of serum. Besides stimulating bone resorption, RA and 1,25-(OH)2D3 increased the number of osteoclasts in 19-day-old fetal rat tibiae. Likewise, these bone-resorbing agents induced and stimulated osteoclast formation in 19- and 18-day-old metatarsal bones which were osteoclast-free at the beginning of the culture. The response to 1,25-(OH)2D3 was greatly enhanced by 10% fetal bovine serum (FBS) irrespective of the developmental stage of the long bone. The response to RA was not. Light microscopic autoradiography after labeling of the cultures with tritiated thymidine showed that both RA and 1,25-(OH)2D3 induced osteoclast differentiation from proliferating and postmitotic precursors. However, neither agent was able to stimulate proliferation of osteoclast progenitor cells in the older bones (19 days). Studies on the formation of osteoclast-like (tartrate-resistant acid phosphatase positive) cells in bone marrow cultures indicated that FBS was a potent inducer of osteoclast-like cell formation. In the presence of FBS, 1,25-(OH)2D3 significantly stimulated this response, but RA did not. The results demonstrate that although both RA and 1,25-(OH)2D3 stimulate osteoclast formation from proliferating and postmitotic precursors in long bones in vitro, they do so by different mechanisms.

  6. Metabolism in vivo of all-trans-[11-3H]retinoic acid after an oral dose in rats. Characterization of retinoyl beta-glucuronide in the blood and other tissues.

    PubMed Central

    Barua, A B; Gunning, D B; Olson, J A

    1991-01-01

    Soon after [11-3H]retinoic acid (RA) (1.1 x 10(8) d.p.m.) was administered orally to rats either as a large dose (115 micrograms = 0.38 mumol/rat) or mixed with unlabelled RA as a huge dose (22 mg = 73.33 mumol/rat), retinoyl beta-glucuronide (RAG) was identified and characterized as a significant metabolite in the serum and small intestine. Of the administered dose, 70% remained unchanged as retinoic acid in the stomach up to 1 h. Significant amounts of 5,6-epoxyretinoic acid, 4-hydroxyretinoic acid, esters of retinoic acid and several polar retinoids, including 4-oxoretinoic acid, were also detected in the stomach. No significant difference was observed in the nature of the retinoids found after a large or a huge dose; however, the ratio of RAG/RA was higher after a huge dose than after a large dose. Thus RAG, which is biologically active in vivo and in vitro, is formed quickly in significant amounts in tissues after a dose of RA. PMID:1859380

  7. 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

  8. Inhibitory effect of retinoic acid on the respiratory burst of adult and cord blood neutrophils and macrophages: potential implication to bronchopulmonary dysplasia.

    PubMed Central

    Wolfson, M; Shinwell, E S; Zvillich, M; Rager-Zisman, B

    1988-01-01

    Infants suffering from bronchopulmonary dysplasia (BPD) are known to have low levels of vitamin A, a factor which may be implicated in the pathogenesis of the condition. The ability of retinoic acid (RA) (one of the active forms of vitamin A) to influence the production of superoxide anion (02-) and hydrogen peroxide (H2O2) by stimulated human adult or cord blood neutrophils and macrophages has been studied. RA was found to inhibit the O2- and H2O2 production in a dose-dependent manner. The time required for maximal inhibition was 30 min for neutrophils and 24 h for macrophages. Although cord blood neutrophils produced larger quantities of O2- and H2O2 both with and without RA, the degree of inhibition was similar in both adult and neonatal cells (40-60%). The results suggest that retinoic acid may prevent neutrophil and macrophage mediated lung damage by inhibiting the production of toxic oxygen compounds, especially in BPD conditions. PMID:2844454

  9. Overexpression of CRABPI in suprabasal keratinocytes enhances the proliferation of epidermal basal keratinocytes in mouse skin topically treated with all-trans retinoic acid

    SciTech Connect

    Tang, X.-H.; Vivero, Marina; Gudas, Lorraine J.

    2008-01-01

    We investigated whether ectopic expression of CRABPI, a cellular retinoic acid binding protein, influenced the actions of all-trans retinoic acid (ATRA) in transgenic (TG) mice. We targeted CRABPI to the basal vs. suprabasal layers of mouse epidermis by using the keratin 14 (K14) and keratin 10 (K10) promoters, respectively. Greater CRABPI protein levels were detected in the epidermis of adult transgenic(+) mice than in transgenic(-) mice for both transgenes. In adult mouse skin CRABPI overexpression in the basal or suprabasal keratinocytes did not cause morphological abnormalities, but did result in decreased CRABPII mRNA levels. Ectopically overexpressed CRABPI in suprabasal keratinocytes, but not in basal keratinocytes, enhanced the thickening of the epidermis induced by topical ATRA treatments (10 {mu}M, 400 {mu}l for 4 days) by 1.59 {+-} 0.2-fold (p < 0.05). ATRA treatment (10 {mu}M) resulted in a 59.9 {+-} 9.8% increase (p < 0.05) in the BrdU labeling index in K10/FLAG-CRABPI TG(+) mice vs. TG(-) mice. Retinoid topical treatments reduced p27 and CYP26A1 mRNA levels in TG(+) and TG(-) mouse skin in K14 and K10/FLAG-CRABPI transgenic mice. As epidermal basal keratinocyte proliferation is stimulated by paracrine growth factors secreted by ATRA activated suprabasal keratinocytes, our results indicate that CRABPI overexpression in suprabasal keratinocytes enhances the physiological functions of ATRA.

  10. Retinoic acid-metabolizing enzyme cytochrome P450 26a1 (cyp26a1) is essential for implantation: functional study of its role in early pregnancy.

    PubMed

    Han, Bing-Chen; Xia, Hong-Fei; Sun, Jing; Yang, Ying; Peng, Jing-Pian

    2010-05-01

    Vitamin A (VA) is required for normal fetal development and successful pregnancy. Excessive VA intake during pregnancy may lead to adverse maternal and fetal effects. Cytochrome P450 26A1 (cyp26a1), a retinoic acid (RA)-metabolizing enzyme, is involved in VA metabolism. It has been shown that cyp26a1 is expressed in female reproductive tract, especially in uterus. In order to investigate the role of cyp26a1 during pregnancy, we constructed a recombinant plasmid DNA vaccine encoding cyp26a1 protein and immunized mice with the plasmid. Compared to control groups, the pregnancy rate of the cyp26a1 plasmid-immunized mice were significantly decreased (P < 0.01). Further results showed that both cyp26a1 mRNA and protein were specifically induced in the uterus during implantation period and localized in the uterine luminal epithelium. Importantly, the number of implantation sites was also significantly reduced (P < 0.05) after the uterine injection of cyp26a1-specific antisense oligos or anti-cyp26a1 antibody on day 3 of pregnancy. Accordingly, the expression of RA-related cellular retinoic acid binding protein 1 and tissue transglutaminase was markedly increased (P < 0.05) in the uterine luminal epithelium after intrauterine injection treatments. These data demonstrate that uterine cyp26a1 activity is important for the maintenance of pregnancy, especially during the process of blastocyst implantation.

  11. NRG1 and KITL signal downstream of retinoic acid in the germline to support soma-free syncytial growth of differentiating spermatogonia

    PubMed Central

    Chapman, KM; Medrano, GA; Chaudhary, J; Hamra, FK

    2015-01-01

    Defined culture systems supporting spermatogonial differentiation will provide experimental platforms to study spermatogenesis. However, germline-intrinsic signaling mechanisms sufficient to support spermatogonial differentiation without somatic cells remain largely undefined. Here we analyzed EGF superfamily receptor and ligand diversity in rat testis cells and delineated germline-intrinsic signaling via an ERBB3 co-transducer, ERBB2, as essential for retinoic acid-induced syncytial growth by differentiating spermatogonia. Similar to the ERBB2/3 agonist NRG1, we found that KIT Ligand (KITL) robustly supported spermatogonial differentiation without serum or somatic cells. ERBB2 inhibitors failed to disrupt KITL-dependent spermatogonial development, and KITL prevented ERBB3-deficient spermatogonial degeneration upon differentiation. Thus we report that NRG1 and KITL activate alternative pathways downstream of retinoic acid signaling in the germline that are essential for stem cells to undergo premeiotic steps of spermatogenesis in culture. Robust serum/soma-free spermatogonial differentiation opens new doors to study mammalian germ cell biology in culture and to discover factors that can drive meiotic progression in vitro. PMID:26500786

  12. Identification of daidzein as a ligand of retinoic acid receptor that suppresses expression of matrix metalloproteinase-9 in HaCaT cells.

    PubMed

    Oh, Hyeon-Jeong; Kang, Young-Gyu; Na, Tae-Young; Kim, Hyeon-Ji; Park, Jun Seong; Cho, Won-Jea; Lee, Mi-Ock

    2013-08-25

    Retinoids have been used as therapeutics for diverse skin diseases, but their side effects limit clinical usage. Here, we report that extracts of two soybeans, Glycine max and Rhynchosia nulubilis, and their ethyl acetate fractions increased the transcriptional activity of retinoic acid receptors (RARs), and that daidzin and genistin were the major constituents of the active fractions. Daidzin and its aglycone, daidzein, induced transcriptional activity of RAR and RARγ. FRET analysis demonstrated that daidzein, but not daidzin, bound both RAR and RARγ with EC50 values of 28μM and 40μM, respectively. Daidzein increased expression of mRNA of RARγ through direct binding of RAR and recruitment of p300 to the RARγ2 promoter. Further, mRNA and gelatinolytic activity of matrix metalloproteinase-9 were decreased by daidzein in HaCaT cells. Together, these results indicate that daidzein functions as a ligand of RAR that could be a candidate therapeutic for skin diseases.

  13. Valproic acid and all trans retinoic acid differentially induce megakaryopoiesis and platelet-like particle formation from