1
|
Abdelhamid L, Luo XM. Retinoic Acid, Leaky Gut, and Autoimmune Diseases. Nutrients 2018; 10:E1016. [PMID: 30081517 PMCID: PMC6115935 DOI: 10.3390/nu10081016] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/25/2018] [Accepted: 07/25/2018] [Indexed: 12/19/2022] Open
Abstract
A leaky gut has been observed in a number of autoimmune diseases including type 1 diabetes, multiple sclerosis, inflammatory bowel disease, and systemic lupus erythematosus. Previous studies from our laboratory have shown that lupus mice also bear a leaky gut and that the intestinal barrier function can be enhanced by gut colonization of probiotics such as Lactobacillus spp. Retinoic acid (RA) can increase the relative abundance of Lactobacillus spp. in the gut. Interestingly, RA has also been shown to strengthen the barrier function of epithelial cells in vitro and in the absence of probiotic bacteria. These reports bring up an interesting question of whether RA exerts protective effects on the intestinal barrier directly or through regulating the microbiota colonization. In this review, we will discuss the roles of RA in immunomodulation, recent literature on the involvement of a leaky gut in different autoimmune diseases, and how RA shapes the outcomes of these diseases.
Collapse
Affiliation(s)
- Leila Abdelhamid
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Xin M Luo
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA.
| |
Collapse
|
2
|
Jauregui EJ, Mitchell D, Topping T, Hogarth CA, Griswold MD. Retinoic acid receptor signaling is necessary in steroidogenic cells for normal spermatogenesis and epididymal function. Development 2018; 145:dev160465. [PMID: 29899137 PMCID: PMC6053667 DOI: 10.1242/dev.160465] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 05/31/2018] [Indexed: 12/24/2022]
Abstract
Spermatogenesis in mammals is a very complex, highly organized process, regulated in part by testosterone and retinoic acid (RA). Much is known about how RA and testosterone signaling pathways independently regulate this process, but there is almost no information regarding whether these two signaling pathways directly interact and whether RA is crucial for steroidogenic cell function. This study uses a transgenic mouse line that expresses a dominant-negative form of RA receptor α (RAR-DN) and the steroidogenic cell-specific Cre mouse line, Cyp17iCre, to generate male mice with steroidogenic cells unable to perform RA signaling. Testes of mutant mice displayed increased apoptosis of pachytene spermatocytes, an increased number of macrophages in the interstitium and a loss of advanced germ cells. Additionally, blocking RA signaling in Leydig cells resulted in increased permeability of the blood-testis barrier, decreased levels of the steroidogenic enzyme cytochrome P450 17a1 and decreased testosterone levels. Surprisingly, the epididymides of the mutant mice also displayed an abnormal phenotype. This study demonstrates that RA signaling is required in steroidogenic cells for their normal function and, thus, for male fertility.
Collapse
Affiliation(s)
- Estela J Jauregui
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
| | - Debra Mitchell
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
| | - Traci Topping
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
| | - Cathryn A Hogarth
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
| | - Michael D Griswold
- School of Molecular Biosciences and the Center for Reproductive Biology, Washington State University, Pullman, WA 99164, Washington, USA
| |
Collapse
|
3
|
Brown G, Marchwicka A, Cunningham A, Toellner KM, Marcinkowska E. Antagonizing Retinoic Acid Receptors Increases Myeloid Cell Production by Cultured Human Hematopoietic Stem Cells. Arch Immunol Ther Exp (Warsz) 2017; 65:69-81. [PMID: 27412076 PMCID: PMC5274652 DOI: 10.1007/s00005-016-0411-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/20/2016] [Indexed: 02/07/2023]
Abstract
Activities of the retinoic acid receptor (RAR)α and RARγ are important to hematopoiesis. Here, we have investigated the effects of receptor selective agonists and antagonists on the primitive human hematopoietic cell lines KG1 and NB-4 and purified normal human hematopoietic stem cells (HSCs). Agonizing RARα (by AGN195183) was effective in driving neutrophil differentiation of NB-4 cells and this agonist synergized with a low amount (10 nM) of 1α,25-dihydroxyvitamin D3 to drive monocyte differentiation of NB-4 and KG1 cells. Treatment of cultures of human HSCs (supplemented with stem cell factor ± interleukin 3) with an antagonist of all RARs (AGN194310) or of RARα (AGN196996) prolonged the lifespan of cultures, up to 55 days, and increased the production of neutrophils and monocytes. Slowing down of cell differentiation was not observed, and instead, hematopoietic stem and progenitor cells had expanded in number. Antagonism of RARγ (by AGN205728) did not affect cultures of HSCs. Studies of CV-1 and LNCaP cells transfected with RAR expression vectors and a reporter vector revealed that RARγ and RARβ are activated by sub-nM all-trans retinoic acid (EC50-0.3 nM): ~50-fold more is required for activation of RARα (EC50-16 nM). These findings further support the notion that the balance of expression and activity of RARα and RARγ are important to hematopoietic stem and progenitor cell expansion and differentiation.
Collapse
Affiliation(s)
- Geoffrey Brown
- Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
| | - Aleksandra Marchwicka
- Laboratory of Protein Biochemistry, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| | - Alan Cunningham
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Kai-Michael Toellner
- Institute of Immunology and Immunotherapy, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Ewa Marcinkowska
- Laboratory of Protein Biochemistry, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland
| |
Collapse
|
4
|
Mendoza-Parra MA, Malysheva V, Mohamed Saleem MA, Lieb M, Godel A, Gronemeyer H. Reconstructed cell fate-regulatory programs in stem cells reveal hierarchies and key factors of neurogenesis. Genome Res 2016; 26:1505-1519. [PMID: 27650846 PMCID: PMC5088593 DOI: 10.1101/gr.208926.116] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Accepted: 09/16/2016] [Indexed: 01/24/2023]
Abstract
Cell lineages, which shape the body architecture and specify cell functions, derive from the integration of a plethora of cell intrinsic and extrinsic signals. These signals trigger a multiplicity of decisions at several levels to modulate the activity of dynamic gene regulatory networks (GRNs), which ensure both general and cell-specific functions within a given lineage, thereby establishing cell fates. Significant knowledge about these events and the involved key drivers comes from homogeneous cell differentiation models. Even a single chemical trigger, such as the morphogen all-trans retinoic acid (RA), can induce the complex network of gene-regulatory decisions that matures a stem/precursor cell to a particular step within a given lineage. Here we have dissected the GRNs involved in the RA-induced neuronal or endodermal cell fate specification by integrating dynamic RXRA binding, chromatin accessibility, epigenetic promoter epigenetic status, and the transcriptional activity inferred from RNA polymerase II mapping and transcription profiling. Our data reveal how RA induces a network of transcription factors (TFs), which direct the temporal organization of cognate GRNs, thereby driving neuronal/endodermal cell fate specification. Modeling signal transduction propagation using the reconstructed GRNs indicated critical TFs for neuronal cell fate specification, which were confirmed by CRISPR/Cas9-mediated genome editing. Overall, this study demonstrates that a systems view of cell fate specification combined with computational signal transduction models provides the necessary insight in cellular plasticity for cell fate engineering. The present integrated approach can be used to monitor the in vitro capacity of (engineered) cells/tissues to establish cell lineages for regenerative medicine.
Collapse
Affiliation(s)
- Marco-Antonio Mendoza-Parra
- Equipe Labellisée Ligue Contre le Cancer, Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, UMR7104, Institut National de la Santé et de la Recherche Médicale, U964, Université de Strasbourg, Illkirch, France
| | - Valeriya Malysheva
- Equipe Labellisée Ligue Contre le Cancer, Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, UMR7104, Institut National de la Santé et de la Recherche Médicale, U964, Université de Strasbourg, Illkirch, France
| | - Mohamed Ashick Mohamed Saleem
- Equipe Labellisée Ligue Contre le Cancer, Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, UMR7104, Institut National de la Santé et de la Recherche Médicale, U964, Université de Strasbourg, Illkirch, France
| | - Michele Lieb
- Equipe Labellisée Ligue Contre le Cancer, Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, UMR7104, Institut National de la Santé et de la Recherche Médicale, U964, Université de Strasbourg, Illkirch, France
| | - Aurelie Godel
- Equipe Labellisée Ligue Contre le Cancer, Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, UMR7104, Institut National de la Santé et de la Recherche Médicale, U964, Université de Strasbourg, Illkirch, France
| | - Hinrich Gronemeyer
- Equipe Labellisée Ligue Contre le Cancer, Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, UMR7104, Institut National de la Santé et de la Recherche Médicale, U964, Université de Strasbourg, Illkirch, France
| |
Collapse
|
5
|
Abstract
Nuclear receptors (NR) act as an integrated conduit for environmental and hormonal signals to govern genomic responses, which relate to cell fate decisions. We review how their integrated actions with each other, shared co-factors and other transcription factors are disrupted in cancer. Steroid hormone nuclear receptors are oncogenic drivers in breast and prostate cancer and blockade of signaling is a major therapeutic goal. By contrast to blockade of receptors, in other cancers enhanced receptor function is attractive, as illustrated initially with targeting of retinoic acid receptors in leukemia. In the post-genomic era large consortia, such as The Cancer Genome Atlas, have developed a remarkable volume of genomic data with which to examine multiple aspects of nuclear receptor status in a pan-cancer manner. Therefore to extend the review of NR function we have also undertaken bioinformatics analyses of NR expression in over 3000 tumors, spread across six different tumor types (bladder, breast, colon, head and neck, liver and prostate). Specifically, to ask how the NR expression was distorted (altered expression, mutation and CNV) we have applied bootstrapping approaches to simulate data for comparison, and also compared these NR findings to 12 other transcription factor families. Nuclear receptors were uniquely and uniformly downregulated across all six tumor types, more than predicted by chance. These approaches also revealed that each tumor type had a specific NR expression profile but these were most similar between breast and prostate cancer. Some NRs were down-regulated in at least five tumor types (e.g. NR3C2/MR and NR5A2/LRH-1)) whereas others were uniquely down-regulated in one tumor (e.g. NR1B3/RARG). The downregulation was not driven by copy number variation or mutation and epigenetic mechanisms maybe responsible for the altered nuclear receptor expression.
Collapse
Affiliation(s)
- Mark D Long
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Elm & Carlton Streets, Buffalo, NY 14263, USA
| | - Moray J Campbell
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Elm & Carlton Streets, Buffalo, NY 14263, USA
| |
Collapse
|
6
|
Gassié L, Lombard A, Moraldi T, Bibonne A, Leclerc C, Moreau M, Marlier A, Gilbert T. Hspa9 is required for pronephros specification and formation inXenopus laevis. Dev Dyn 2015; 244:1538-49. [DOI: 10.1002/dvdy.24344] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 07/29/2015] [Accepted: 08/17/2015] [Indexed: 01/13/2023] Open
Affiliation(s)
- Lionel Gassié
- Université Toulouse 3 Centre de Biologie du Développement; Toulouse France
| | | | - Tiphanie Moraldi
- Université Lyon 1 Institut Universitaire Technologique; Villeurbanne France
| | - Anne Bibonne
- Université Toulouse 3 Centre de Biologie du Développement; Toulouse France
- CNRS UMR 5547; Toulouse France
| | - Catherine Leclerc
- Université Toulouse 3 Centre de Biologie du Développement; Toulouse France
- CNRS UMR 5547; Toulouse France
| | - Marc Moreau
- Université Toulouse 3 Centre de Biologie du Développement; Toulouse France
- CNRS UMR 5547; Toulouse France
| | - Arnaud Marlier
- Yale' School of Medicine Department of Internal Medicine; New Haven Connecticut USA
| | - Thierry Gilbert
- Université Toulouse 3 Centre de Biologie du Développement; Toulouse France
- CNRS UMR 5547; Toulouse France
- Institut National de la Santé et de la Recherche Médicale; Toulouse France
| |
Collapse
|
7
|
Anakoinosis: Communicative Reprogramming of Tumor Systems - for Rescuing from Chemorefractory Neoplasia. CANCER MICROENVIRONMENT 2015; 8:75-92. [PMID: 26259724 PMCID: PMC4542828 DOI: 10.1007/s12307-015-0170-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 06/30/2015] [Indexed: 12/24/2022]
Abstract
Disruptive technologies, such as communicative reprogramming (anakoinosis) with cellular therapies in situ for treating refractory metastatic cancer allow patient care to accelerate along a totally new trajectory and highlight what may well become the next sea change in the care of patients with many types of advanced neoplasia. Cellular therapy in situ consisted of repurposed drugs, pioglitazone plus all-trans retinoic acid or dexamethasone or interferon-alpha (dual transcriptional modulation) combined with metronomic low-dose chemotherapy or low-dose 5-azacytidine, plus/minus classic targeted therapy. The novel therapeutic tools for specifically designing communication processes within tumor diseases focus on redirecting (1) rationalizations of cancer hallmarks (constitution of single cancer hallmarks), (2) modular events, (3) the 'metabolism' of evolutionary processes (the sum of therapeutically and intrinsically inducible evolutionary processes) and (4) the holistic communicative context, which determines validity and denotation of tumor promoting communication lines. Published data on cellular therapies in situ (6 histologic tumor types, 144 patients, age 0.9-83 years) in castration-resistant prostate cancer, pretreated renal clear cell carcinoma, chemorefractory acute myelocytic leukemia, multiple myeloma > second-line, chemorefractory Hodgkin lymphoma or multivisceral Langerhans cell histiocytosis, outline the possibility for treating refractory metastatic cancer with the hope that this type of reprogrammed communication will be scalable with minimal toxicity. Accessibility to anakoinosis is a tumor inherent feature, and cellular therapy in situ addresses extrinsic and intrinsic drug resistance, by redirecting convergent organized communication tools, while been supported by quite different pattern of (molecular-)genetic aberrations.
Collapse
|
8
|
Harbers M. Shift-Western Blotting: Separate Analysis of Protein and DNA from Protein-DNA Complexes. Methods Mol Biol 2015; 1312:355-73. [PMID: 26044017 DOI: 10.1007/978-1-4939-2694-7_36] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The electrophoretic mobility shift assay (EMSA) is the most frequently used experiment for studying protein-DNA interactions and to identify DNA-binding proteins. Protein-DNA complexes formed during EMSA experiments can be further analyzed by shift-western blotting, where the protein and DNA components contained in a polyacrylamide gel are transferred to stacked membranes: First a nitrocellulose membrane retains the proteins while double-stranded DNA passes through the nitrocellulose membrane and binds only to a charged membrane placed below. Immobilized proteins can then be stained with specific antibodies while the DNA can be detected by a radioactive label or a nonradioactive detection system. Shift-western blotting can overcome many limitations of supershift experiments and allows for the analysis of complex protein-DNA complexes containing multiple protein factors. Moreover, proteins and/or DNA may be recovered from membranes after the blotting step for further analysis by other means.
Collapse
Affiliation(s)
- Matthias Harbers
- Division of Genomic Technologies, RIKEN Center for Life Science Technologies, RIKEN Yokohama Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan,
| |
Collapse
|
9
|
Iskakova M, Karbyshev M, Piskunov A, Rochette-Egly C. Nuclear and extranuclear effects of vitamin A. Can J Physiol Pharmacol 2015; 93:1065-75. [PMID: 26459513 DOI: 10.1139/cjpp-2014-0522] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Vitamin A or retinol is a multifunctional vitamin that is essential at all stages of life from embryogenesis to adulthood. Up to now, it has been accepted that the effects of vitamin A are exerted by active metabolites, the major ones being 11-cis retinal for vision, and all trans-retinoic acid (RA) for cell growth and differentiation. Basically RA binds nuclear receptors, RARs, which regulate the expression of a battery of target genes in a ligand dependent manner. During the last decade, new scenarios have been discovered, providing a rationale for the understanding of other long-noted but not explained functions of retinol. These novel scenarios involve: (i) other nuclear receptors such as PPAR β/δ, which regulate the expression of other target genes with other functions; (ii) extranuclear and nontranscriptional effects, such as the activation of kinases, which phosphorylate RARs and other transcription factors, thus expanding the list of the RA-activated genes; (iii) finally, vitamin A is active per se and can work as a cytokine that regulates gene transcription by activating STRA6. New effects of vitamin A and RA are continuously being discovered in new fields, revealing new targets and new mechanisms thus improving the understanding the pleiotropicity of their effects.
Collapse
Affiliation(s)
- Madina Iskakova
- a Division of Cell Biology and Cell Line Development, The International Biotechnology Center « Generium », Vladimirskaya Street 14, Volginsky, 601125, Russian Federation
| | - Mikhail Karbyshev
- a Division of Cell Biology and Cell Line Development, The International Biotechnology Center « Generium », Vladimirskaya Street 14, Volginsky, 601125, Russian Federation
| | - Aleksandr Piskunov
- a Division of Cell Biology and Cell Line Development, The International Biotechnology Center « Generium », Vladimirskaya Street 14, Volginsky, 601125, Russian Federation
| | - Cécile Rochette-Egly
- b Department of Functional Genomics and Cancer, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), INSERM, U964; CNRS, UMR7104; Université de Strasbourg, 1 rue Laurent Fries, BP 10142, 67404 Illkirch Cedex, France
| |
Collapse
|
10
|
di Masi A, Leboffe L, De Marinis E, Pagano F, Cicconi L, Rochette-Egly C, Lo-Coco F, Ascenzi P, Nervi C. Retinoic acid receptors: from molecular mechanisms to cancer therapy. Mol Aspects Med 2015; 41:1-115. [PMID: 25543955 DOI: 10.1016/j.mam.2014.12.003] [Citation(s) in RCA: 240] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/15/2014] [Indexed: 02/07/2023]
Abstract
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.
Collapse
Affiliation(s)
- Alessandra di Masi
- Department of Science, Roma Tre University, Viale Guglielmo Marconi 446, Roma I-00146, Italy
| | - Loris Leboffe
- Department of Science, Roma Tre University, Viale Guglielmo Marconi 446, Roma I-00146, Italy
| | - Elisabetta De Marinis
- Department of Medical and Surgical Sciences and Biotechnologies, University of Roma "La Sapienza", Corso della Repubblica 79, Latina I-04100
| | - Francesca Pagano
- Department of Medical and Surgical Sciences and Biotechnologies, University of Roma "La Sapienza", Corso della Repubblica 79, Latina I-04100
| | - Laura Cicconi
- Department of Biomedicine and Prevention, University of Roma "Tor Vergata", Via Montpellier 1, Roma I-00133, Italy; Laboratory of Neuro-Oncohematology, Santa Lucia Foundation, Via Ardeatina, 306, Roma I-00142, Italy
| | - Cécile Rochette-Egly
- Department of Functional Genomics and Cancer, IGBMC, CNRS UMR 7104 - Inserm U 964, University of Strasbourg, 1 rue Laurent Fries, BP10142, Illkirch Cedex F-67404, France.
| | - Francesco Lo-Coco
- Department of Biomedicine and Prevention, University of Roma "Tor Vergata", Via Montpellier 1, Roma I-00133, Italy; Laboratory of Neuro-Oncohematology, Santa Lucia Foundation, Via Ardeatina, 306, Roma I-00142, Italy.
| | - Paolo Ascenzi
- Interdepartmental Laboratory for Electron Microscopy, Roma Tre University, Via della Vasca Navale 79, Roma I-00146, Italy.
| | - Clara Nervi
- Department of Medical and Surgical Sciences and Biotechnologies, University of Roma "La Sapienza", Corso della Repubblica 79, Latina I-04100.
| |
Collapse
|
11
|
Synergistic interactions between the molecular and neuronal circadian networks drive robust behavioral circadian rhythms in Drosophila melanogaster. PLoS Genet 2014; 10:e1004252. [PMID: 24698952 PMCID: PMC3974645 DOI: 10.1371/journal.pgen.1004252] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 02/05/2014] [Indexed: 01/04/2023] Open
Abstract
Most organisms use 24-hr circadian clocks to keep temporal order and anticipate daily environmental changes. In Drosophila melanogaster CLOCK (CLK) and CYCLE (CYC) initiates the circadian system by promoting rhythmic transcription of hundreds of genes. However, it is still not clear whether high amplitude transcriptional oscillations are essential for circadian timekeeping. In order to address this issue, we generated flies in which the amplitude of CLK-driven transcription can be reduced partially (approx. 60%) or strongly (90%) without affecting the average levels of CLK-target genes. The impaired transcriptional oscillations lead to low amplitude protein oscillations that were not sufficient to drive outputs of peripheral oscillators. However, circadian rhythms in locomotor activity were resistant to partial reduction in transcriptional and protein oscillations. We found that the resilience of the brain oscillator is depending on the neuronal communication among circadian neurons in the brain. Indeed, the capacity of the brain oscillator to overcome low amplitude transcriptional oscillations depends on the action of the neuropeptide PDF and on the pdf-expressing cells having equal or higher amplitude of molecular rhythms than the rest of the circadian neuronal groups in the fly brain. Therefore, our work reveals the importance of high amplitude transcriptional oscillations for cell-autonomous circadian timekeeping. Moreover, we demonstrate that the circadian neuronal network is an essential buffering system that protects against changes in circadian transcription in the brain. Circadian clocks allow organisms to predict daily environmental changes. These clocks time the sleep/wake cycles and many other physiological and cellular pathways to 24hs rhythms. The current model states that circadian clocks keep time by the use of biochemical feedback loops. These feedback loops are responsible for the generation of high amplitude oscillations in gene expression. Abolishment of circadian transcriptional oscillations has been shown to abolish circadian function. Previous studies addressing this issue utilize manipulations in which the abolishment of the transcriptional oscillations is very dramatic and involves strong up or down-regulation of circadian genes. In this study we generated fruit flies in which we diminished the amplitude of circadian oscillations in a controlled way. We found that a decrease of more than 50% in the amplitude of circadian oscillations leads to impaired function of circadian physiological outputs in the periphery but does not significantly affect circadian behavior. This suggests that the clock in the brain has a specific compensatory mechanism. Moreover, we found that flies with reduced oscillation and impaired circadian neuronal communication display aberrant circadian rhythms. These finding support the idea of network buffering mechanisms that allows the brain to produce circadian rhythms even with low amplitude molecular oscillations.
Collapse
|
12
|
Yim CY, Mao P, Spinella MJ. Headway and hurdles in the clinical development of dietary phytochemicals for cancer therapy and prevention: lessons learned from vitamin A derivatives. AAPS JOURNAL 2014; 16:281-8. [PMID: 24431081 DOI: 10.1208/s12248-014-9562-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 01/02/2014] [Indexed: 01/11/2023]
Abstract
Accumulating epidemiologic and preclinical evidence support the pharmacologic use of a variety of dietary chemicals for the prevention and treatment of cancer. However, it will be challenging to translate these findings into routine clinical practice since phytochemicals have pleiotropic biological activities that have to be balanced for optimal efficacy without unacceptable and potentially unanticipated toxicities. Correctly matching patient populations and settings with optimal, natural product-based phytochemical therapies will require a greater understanding of the specific mechanisms underlying the efficacy, toxicity, and resistance of each agent in a variety of normal, premalignant, and malignant settings. This, in turn, necessitates continued commitment from the basic research community to guide carefully designed and informed clinical trials. The most developed class of anticancer phytochemicals consists of the derivatives of vitamin A called retinoids. Unlike other natural product chemicals currently under study, the retinoids have been extensively tested in humans. Over 30 years of clinical investigation has resulted in several disappointments, but there were some spectacular successes where certain retinoid-based protocols are now FDA-approved standard of care therapies to treat specific malignancies. Furthermore, retinoids are one of the most evaluated pharmacologic agents in the ultra-challenging setting of interventional cancer prevention. This review will summarize the development of retinoids in cancer therapy and prevention with an emphasis on currently proposed mechanisms mediating their efficacy, toxicity, and resistance.
Collapse
Affiliation(s)
- Christina Y Yim
- Department of Pharmacology and Toxicology, Geisel School of Medicine at Dartmouth, 7650 Remsen, Hanover, New Hampshire, 03755, USA
| | | | | |
Collapse
|
13
|
Abstract
Retinoids and rexinoids, as all other ligands of the nuclear receptor (NR) family, act as ligand-regulated trans-acting transcription factors that bind to cis-acting DNA regulatory elements in the promoter regions of target genes (for reviews see [12, 22, 23, 26, 36]). Ligand binding modulates the communication functions of the receptor with the intracellular environment, which essentially entails receptor-protein and receptor-DNA or receptor-chromatin interactions. In this communication network, the receptor simultaneously serves as both intracellular sensor and regulator of cell/organ functions. Receptors are "intelligent" mediators of the information encoded in the chemical structure of a nuclear receptor ligand, as they interpret this information in the context of cellular identity and cell-physiological status and convert it into a dynamic chain of receptor-protein and receptor-DNA interactions. To process input and output information, they are composed of a modular structure with several domains that have evolved to exert particular molecular recognition functions. As detailed in other chapters in this volume, the main functional domains are the DNA-binding (DBD) and ligand-binding (LBD) [5-7, 38, 56, 71]. The LBD serves as a dual input-output information processor. Inputs, such as ligand binding or receptor phosphorylations, induce allosteric changes in receptor surfaces that serve as docking sites for outputs, such as subunits of transcription and epigenetic machineries or enzyme complexes. The complexity of input and output signals and their interdependencies is far from being understood.
Collapse
Affiliation(s)
- Marco-Antonio Mendoza-Parra
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS, INSERM, Université de Strasbourg, BP 10142, 67404, Illkirch Cedex, France
| | | |
Collapse
|