1
|
Nair SS, Das S S, Nair RP, Indira M. Supplementation of all trans retinoic acid ameliorates ethanol-induced endoplasmic reticulum stress. Arch Physiol Biochem 2018; 124:131-138. [PMID: 28857622 DOI: 10.1080/13813455.2017.1369548] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
CONTEXT Molecular pathogenesis of chronic alcoholism is linked to increased endoplasmic reticulum stress. Ethanol is a competitive inhibitor of vitamin A metabolism and vitamin A supplementation aggravates existing liver problems. Hence, we probed into the impact of supplementation of all trans retinoic acid (ATRA), the active metabolite of vitamin A on ethanol-induced endoplasmic reticulcum stress. METHODS Male Sprague-Dawley rats were divided into four groups - I: Control; II: Ethanol; III: ATRA; IV: ATRA + Ethanol. After 90 days the animals were sacrificed to study markers of lipid peroxidation in hepatic microsomal fraction and expression of ER stress proteins and apoptosis in liver. RESULTS AND CONCLUSION Ethanol caused hepatic hyperlipidemia, enhanced microsomal lipid peroxidation, upregulated expression of unfolded protein response associated proteins and that of apoptosis. Ethanol also led to downregulation of retinoid receptors. ATRA supplementation reversed all these alterations indicating the decrease in ethanol-induced endoplasmic reticulum stress.
Collapse
Affiliation(s)
- Saritha S Nair
- a Department of Biochemistry , University of Kerala , Thiruvananthapuram , Kerala , India
| | - Syam Das S
- a Department of Biochemistry , University of Kerala , Thiruvananthapuram , Kerala , India
| | - Reshma P Nair
- b Agroprocessing and Technology Division , CSIR-NIIST , Thiruvananthapuram , Kerala , India
| | - M Indira
- a Department of Biochemistry , University of Kerala , Thiruvananthapuram , Kerala , India
| |
Collapse
|
2
|
Zhang XK, Su Y, Chen L, Chen F, Liu J, Zhou H. Regulation of the nongenomic actions of retinoid X receptor-α by targeting the coregulator-binding sites. Acta Pharmacol Sin 2015; 36:102-12. [PMID: 25434990 DOI: 10.1038/aps.2014.109] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 09/28/2014] [Indexed: 12/31/2022] Open
Abstract
Retinoid X receptor-α (RXRα), a unique member of the nuclear receptor superfamily, represents an intriguing and unusual target for pharmacologic interventions and therapeutic applications in cancer, metabolic disorders and neurodegenerative diseases. Despite the fact that the RXR-based drug Targretin (bexarotene) is currently used for treating human cutaneous T-cell lymphoma and the fact that RXRα ligands (rexinoids) show beneficial effects in the treatment of cancer and diseases, the therapeutic potential of RXRα remains unexplored. In addition to its conventional transcription regulation activity in the nucleus, RXRα can act in the cytoplasm to modulate important biological processes, such as mitochondria-dependent apoptosis, inflammation, and phosphatidylinositol 3-kinase (PI3K)/AKT-mediated cell survival. Recently, new small-molecule-binding sites on the surface of RXRα have been identified, which mediate the regulation of the nongenomic actions of RXRα by a class of small molecules derived from the nonsteroidal anti-inflammatory drug (NSAID) Sulindac. This review discusses the emerging roles of the nongenomic actions of RXRα in the RXRα signaling network, and their possible implications in cancer, metabolic and neurodegenerative disorders, as well as our current understanding of RXRα regulation by targeting alternate binding sites on its surface.
Collapse
|
3
|
Longville BAC, Anderson D, Welch MD, Kees UR, Greene WK. Aberrant expression of aldehyde dehydrogenase 1A (ALDH1A) subfamily genes in acute lymphoblastic leukaemia is a common feature of T-lineage tumours. Br J Haematol 2014; 168:246-57. [DOI: 10.1111/bjh.13120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 07/29/2014] [Indexed: 12/23/2022]
Affiliation(s)
- Brooke A. C. Longville
- Division of Children's Leukaemia and Cancer Research; Telethon Kids Institute; University of Western Australia; Perth WA 6008 Australia
| | - Denise Anderson
- Telethon Kids Institute; Centre for Child Health Research; The University of Western Australia; Perth WA 6008 Australia
| | - Mathew D. Welch
- Division of Children's Leukaemia and Cancer Research; Telethon Kids Institute; University of Western Australia; Perth WA 6008 Australia
| | - Ursula R. Kees
- Division of Children's Leukaemia and Cancer Research; Telethon Kids Institute; University of Western Australia; Perth WA 6008 Australia
| | - Wayne K. Greene
- School of Veterinary and Life Sciences; Murdoch University; Perth WA Australia
| |
Collapse
|
4
|
Abstract
Proper regulation of T cell death is of vital importance for the function of the immune system. Positive and negative selection of developing T cells in the thymus ensures the survival of only those T cells that can recognize peptides presented by self-MHC molecules and at the same time not respond to self-antigens, and thus, T cell death within the thymus is instrumental in shaping the mature T cell repertoire. The death of activated peripheral T cells is crucial for processes such as down-modulation of immune responses after clearance of infectious agents, peripheral tolerance, and maintenance of immune-privileged sites. These processes are largely proceeding due to the enhanced susceptibility of activated T cells to spontaneous, activation-, and Fas-induced apoptosis. The active metabolite of the immune regulator vitamin A, retinoic acid, has been reported to influence various types of apoptotic processes in both thymocytes and activated peripheral T cells. This chapter gives an overview of, and discusses the reported effects of vitamin A on spontaneous and activation-induced cell death of thymocytes and mature T cells, as well as on Fas-induced T cell death.
Collapse
|
5
|
Abstract
Recommendations for vitamin A intake are based on maintaining liver stores of > or = 0.070 micromol/g, which is sufficient to maintain normal vision. We propose that higher levels may be required to maintain normal immune function. To test this hypothesis, we conducted an 8-week residential study among thirty-six healthy Bangladeshi men with low vitamin A stores. Subjects were randomised to receive vitamin A (240 mg in four doses) or placebo during study weeks 2 and 3. Vitamin A stores were estimated by isotopic dilution at week 8. Total T-cells, the naive T-cells:memory T-cells ratio and mitogen-induced lymphocyte proliferation were positively and significantly correlated with vitamin A stores (P < 0.05). Mitogen-stimulated IL-2, IL-4 and TNFalpha increased significantly (P < 0.05) in the vitamin A but not placebo group after supplementation, while IL-10 production was significantly and negatively correlated with vitamin A stores (P < 0.05). Segmented linear regression analysis revealed that naive T-cell counts and T-cell blastogenesis were positively associated with vitamin A stores above but not below 0.070 mumol/g liver. These data show that increasing vitamin A stores above the level that maintains normal vision enhances some measures of T-cell-mediated immunity, suggesting a difference in requirements for maintaining vision and immune function.
Collapse
|
6
|
An RPE cell line as a useful in vitro model for studying retinoic acid receptor beta: expression and affinity. Biosci Rep 2009; 28:327-34. [PMID: 18673301 DOI: 10.1042/bsr20080103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Retinoids mediate their biological effect by interacting with specific nuclear receptors. Of the several known RAR (retinoic acid receptor) subtypes, RAR-beta is of particular interest, since its expression is silenced in many cancers and it is believed to be a tumour suppressor. Specific ligands of RAR-beta can potentially be used in anti-cancer therapy. In the present study, we have investigated the feasibility of using HRPE cells (human retinal pigment epithelial cells) as an experimental model for characterizing RAR-beta-ligand interaction. RT-PCR (reverse transcription-PCR) and Western blot analyses show that HRPE cells specifically express only RAR-beta and none of the other receptor subtypes. In addition, we show that the expression of RAR-beta increases with increasing passage number of the cells. Interestingly, the increase in RAR-beta expression is not associated with telomere shortening, a typical biomarker of cellular senescence. In the present study, we also describe a protocol for characterizing RAR-beta-ligand interactions using nuclear extract from late passage HRPE cells as a source of endogenous RAR-beta. Using [(3)H]CD367 as the ligand, RAR-beta in HRPE cells showed an affinity of 9.6 +/- 0.6 nM and a B(max) of 780 +/- 14 fmol/mg of protein. We have confirmed the feasibility of using this assay to detect the interaction of ligands with RAR-beta by investigating the ability of certain flavonoids to inhibit the binding of [(3)H]CD367 to nuclear extracts from HRPE cells. The inhibition constant of the flavonoids for RAR-beta was between approx. 1-30 microM, showing that the flavonoids interact with RAR-beta with low affinity.
Collapse
|
7
|
Engedal N, Auberger P, Blomhoff HK. Retinoic acid regulates Fas-induced apoptosis in Jurkat T cells: reversal of mitogen-mediated repression of Fas DISC assembly. J Leukoc Biol 2008; 85:469-80. [DOI: 10.1189/jlb.1107790] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
|
8
|
Rasooly R, Schuster GU, Gregg JP, Xiao JH, Chandraratna RAS, Stephensen CB. Retinoid x receptor agonists increase bcl2a1 expression and decrease apoptosis of naive T lymphocytes. THE JOURNAL OF IMMUNOLOGY 2006; 175:7916-29. [PMID: 16339527 DOI: 10.4049/jimmunol.175.12.7916] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Vitamin A affects many aspects of T lymphocyte development and function. The vitamin A metabolites all-trans- and 9-cis-retinoic acid regulate gene expression by binding to the retinoic acid receptor (RAR), while 9-cis-retinoic acid also binds to the retinoid X receptor (RXR). Naive DO11.10 T lymphocytes expressed mRNA and protein for RAR-alpha, RXR-alpha, and RXR-beta. DNA microarray analysis was used to identify RXR-responsive genes in naive DO11.10 T lymphocytes treated with the RXR agonist AGN194204. A total of 128 genes was differentially expressed, including 16 (15%) involved in cell growth or apoptosis. Among these was Bcl2a1, an antiapoptotic Bcl2 family member. Quantitative real-time PCR analysis confirmed this finding and demonstrated that Bcl2a1 mRNA expression was significantly greater in nonapoptotic than in apoptotic T lymphocytes. The RXR agonist 9-cis-retinoic acid also increased Bcl2a1 expression, although all-trans-retinoic acid and ligands for other RXR partner receptors did not. Treatment with AGN194204 and 9-cis-retinoic acid significantly decreased apoptosis measured by annexin V staining but did not affect expression of Bcl2 and Bcl-xL. Bcl2a1 promoter activity was examined using a luciferase promoter construct. Both AGN194204 and 9-cis-retinoic acid significantly increased luciferase activity. In summary, these data demonstrate that RXR agonists increase Bcl2a1 promoter activity and increase expression of Bcl2a1 in naive T lymphocytes but do not affect Bcl2 and Bcl-xL expression in naive T lymphocytes. Thus, this effect on Bcl2a1 expression may account for the decreased apoptosis seen in naive T lymphocytes treated with RXR agonists.
Collapse
Affiliation(s)
- Reuven Rasooly
- U.S. Department of Agriculture (USDA) Western Human Nutrition Research Center and Nutrition Department, University of California, Davis, CA, 95616, USA
| | | | | | | | | | | |
Collapse
|
9
|
Cao X, Liu W, Lin F, Li H, Kolluri SK, Lin B, Han YH, Dawson MI, Zhang XK. Retinoid X receptor regulates Nur77/TR3-dependent apoptosis [corrected] by modulating its nuclear export and mitochondrial targeting. Mol Cell Biol 2004; 24:9705-25. [PMID: 15509776 PMCID: PMC525465 DOI: 10.1128/mcb.24.22.9705-9725.2004] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Retinoid X receptor (RXR) plays a central role in the regulation of intracellular receptor signaling pathways by acting as a ubiquitous heterodimerization partner of many nuclear receptors, including the orphan receptor Nur77 (also known as TR3 [corrected] or NGFI-B), which translocates from the nucleus to mitochondria, where it interacts with Bcl-2 to induce apoptosis. Here, we report that RXRalpha is required for nuclear export and mitochondrial targeting of Nur77 through their unique heterodimerization that is mediated by dimerization interfaces located in their DNA-binding domain. The effects of RXRalpha are attributed to a putative nuclear export sequence (NES) present in its carboxyl-terminal region. RXRalpha ligands suppress NES activity by inducing RXRalpha homodimerization or altering RXRalpha/Nur77 heterodimerization. The RXRalpha NES is also silenced by RXRalpha heterodimerization with retinoic acid receptor or vitamin D receptor. Consistently, we were able to show that the mitochondrial targeting of the RXRalpha/Nur77 heterodimer and its induction of apoptosis are potently inhibited by RXR ligands. Together, our results reveal a novel nongenotropic function of RXRalpha and its involvement in the regulation of the Nur77-dependent apoptotic pathway [corrected]
Collapse
Affiliation(s)
- Xihua Cao
- The Burnham Institute, Cancer Center, 10901 N. Torrey Pines Rd., La Jolla, CA 92037, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Müller M, Grunewald J, Gigliotti D, Eklund A, Stridh H. T-cell activation and the development of an apoptosis-resistant CD45RO+ T-cell population. Scand J Immunol 2003; 57:254-60. [PMID: 12641654 DOI: 10.1046/j.1365-3083.2003.01225.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Growing experimental evidence supports a broadening role for the caspases; not only do they participate in the process of apoptosis but also in the control of the cell cycle and cellular proliferation. The biological role of the caspases in the process of T-cell activation and proliferation is still not defined. In the present study, we propose a potential role, by demonstrating an association of T-cell receptor-mediated caspase activity with the development of an apoptosis-resistant memory CD45RO+ T-cell population. As previously shown by us, a time-dependent induction of caspase activity, in the absence of apoptosis, can be observed in CD3-stimulated human peripheral blood lymphocytes. We here show that a population of CD45RO+ cells, with activated caspase-3 and with resistance to tributyltin-induced apoptosis, develops after 3 days of stimulation. A concomitant expression of the anti-apoptotic protein Bcl-xL accompanied the caspase activity and the development of the apoptosis-resistant phenotype. Finally, upon co-culturing with dexamethasone (DEX), the CD3-induced caspase-3 activity was blocked. During this condition, the expression of the activation marker HLA-DR as well as the cellular proliferative response was strongly suppressed. The development of memory cells with a CD45RO+ phenotype was also blocked. Our data support the hypothesis that caspase-3 activity, observed in CD3-stimulated cells, may be an important component in the proliferation process and, furthermore, might play a role for the development of memory T cells, and DEX inhibits this process.
Collapse
Affiliation(s)
- M Müller
- Department of Medicine, Division of Respiratory Medicine, Karolinska Institutet, Stockholm, Sweden.
| | | | | | | | | |
Collapse
|
11
|
Szabova L, Macejova D, Dvorcakova M, Mostbock S, Blazickova S, Zorad S, Walrand S, Cardinault N, Vasson MP, Rock E, Brtko J. Expression of nuclear retinoic acid receptor in peripheral blood mononuclear cells (PBMC) of healthy subjects. Life Sci 2003; 72:831-6. [PMID: 12479981 DOI: 10.1016/s0024-3205(02)02307-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In vertebrates, both nuclear all-trans and 9-cis retinoic acid receptors (RAR and RXR) belonging to the steroid/thyroid/retinoid nuclear receptor superfamily play a crucial role in the vitamin A action. Qualitative analysis of all known RAR or RXR subtypes in both pooled and non-pooled peripheral blood mononuclear cells (PBMC) from healthy human subjects has been performed by reverse transcription and polymerase chain reaction (RT-PCR). Our data, based on qualitative RT-PCR analysis has shown that human PBMC are capable to express RAR alpha, RAR gamma, RXR alpha, and RXR beta.
Collapse
Affiliation(s)
- L Szabova
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska 3, 833 06 Bratislava, Slovak Republic
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Kavurma MM, Khachigian LM. Signaling and transcriptional control of Fas ligand gene expression. Cell Death Differ 2003; 10:36-44. [PMID: 12655294 DOI: 10.1038/sj.cdd.4401179] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Fas ligand (FasL), a member of the tumor necrosis factor family, initiates apoptosis by binding to its surface receptor Fas. As a consequence, there is sequential activation of caspases and the release of cytochrome c from the mitochondria, with additional caspase activation followed by cellular degradation and death. Recent studies have shed important insight into the molecular mechanisms controlling FasL gene expression at the level of transcription. Nuclear factors such as nuclear factor in activated T cells, nuclear factor-kappa B, specificity protein-1, early growth response factor, interferon regulatory factor, c-Myc and the forkhead transcriptional regulator, alone or cooperatively, activate FasL expression. These factors are often coexpressed with FasL in pathophysiologic settings including human atherosclerotic lesions. Here, we review these important advances in our understanding of the signaling and transcriptional mechanisms controlling FasL gene expression.
Collapse
Affiliation(s)
- M M Kavurma
- Centre for Thrombosis and Vascular Research, Department of Pathology, The University of New South Wales, Sydney, Australia
| | | |
Collapse
|
13
|
Yang Y, Dong B, Mittelstadt PR, Xiao H, Ashwell JD. HIV Tat binds Egr proteins and enhances Egr-dependent transactivation of the Fas ligand promoter. J Biol Chem 2002; 277:19482-7. [PMID: 11909874 DOI: 10.1074/jbc.m201687200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
HIV Tat can enhance activation-induced up-regulation of Fas ligand (FasL), which may contribute to T cell apoptosis in human immune deficiency virus (HIV)-infected individuals. We have assessed functional and physical interactions between Tat and the Egr family of transcription factors (Egr-1, -2, and -3), the latter two of which are major participants in activation-induced FasL up-regulation. Here we report that whereas Tat itself has no effect on the FasL promoter, it binds to Egr-2 and -3 and synergizes with them to superinduce expression of a FasL promoter-driven reporter. A Tat molecule containing a single amino acid substitution that results in the loss of transactivation activity for the HIV long terminal repeat still binds Egr-3 but can no longer enhance Egr-mediated transactivation of the FasL promoter. Furthermore, the mutated Tat acts as a dominant negative inhibitor, blocking the superinduction of FasL caused by wild type Tat. Because Tat is present in virus-infected cells and in the serum of HIV-infected individuals, these results suggest that increased expression of FasL in these circumstances may result from the cooperative activities of activation-induced Egrs and Tat.
Collapse
Affiliation(s)
- Yili Yang
- Laboratory of Immune Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | | | |
Collapse
|
14
|
Lee MO, Kang HJ, Kim YM, Oum JH, Park J. Repression of FasL expression by retinoic acid involves a novel mechanism of inhibition of transactivation function of the nuclear factors of activated T-cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:1162-70. [PMID: 11856352 DOI: 10.1046/j.1432-1033.2002.02748.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Retinoids are potent immune modulators that inhibit Fas ligand (FasL) expression and thereby repress the activation-induced apoptosis of immature thymocytes and T-cell hybridomas. In this study, we demonstrate that all-trans-retinoic acid (all-trans-RA) directly represses the transcriptional activity of the nuclear factors of activated T-cells (NFAT), which is an important transactivator of the FasL promoter. The analysis of reporter constructs containing the FasL promoter and wild-type or mutant NFAT binding-sites indicated that all-trans-RA repression was mediated via an NFAT binding element located in the promoter. A reporter construct comprising the NFAT binding sequence linked to a heterologous SV-40 promoter showed that NFAT transcriptional activity was significantly inhibited by all-trans-RA. Furthermore, all-trans-RA inhibited activation of the distal NFAT binding motif present in the interleukin (IL)-2 promoter, suggesting that the inhibition of NFAT function by all-trans-RA was not specific to the FasL promoter. Gel shift assays corroborated the results of the gene reporter studies by showing that all-trans-RA decreased the NFAT binding to DNA. All-trans-RA blocked translocation of NFATp from the cytosol into the nucleus, which was induced by PMA/ionomycin treatment in HeLa cells transfected with a Flag-tagged NFATp. Taken together, our results indicate that FasL inhibition by all-trans-RA involves a novel mechanism whereby the transcriptional function of NFAT is blocked.
Collapse
Affiliation(s)
- Mi-Ock Lee
- Department of Bioscience and Biotechnology, Institute of Bioscience, Sejong University, Seoul, Korea.
| | | | | | | | | |
Collapse
|
15
|
Yarovinsky TO, Hunninghake GW. Lung fibroblasts inhibit activation-induced death of T cells through PGE(2)-dependent mechanisms. Am J Physiol Lung Cell Mol Physiol 2001; 281:L1248-56. [PMID: 11597917 DOI: 10.1152/ajplung.2001.281.5.l1248] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Activation-induced cell death (AICD) is a regulatory mechanism eliminating excess activated T cells, mainly through a Fas/Fas ligand-dependent mechanism. The goal of this study was to determine whether mouse primary lung fibroblasts are capable of modulating AICD. Using T cell hybridoma DO11.10, we found that fibroblasts in coculture rescue T cells from AICD. Fibroblast-conditioned medium (FCM) also inhibited apoptosis of T cells activated with immobilized anti-CD3 antibody. The effects of lung fibroblasts are mediated, in part, by secreted prostaglandin E(2) (PGE(2)) because treatment of fibroblasts with indomethacin decreased antiapoptotic activity of FCM. Addition of exogenous PGE(2) to FCM from fibroblast cultures treated with indomethacin restored the inhibitory activity of FCM. Expression of Fas receptor and Fas ligand by anti-CD3-activated DO11.10 cells was not affected by PGE(2). However, the same concentrations of PGE(2) significantly downregulated activation of caspase-8 and caspase-3. These results demonstrate that lung fibroblasts inhibit the AICD of T cells by secreting PGE(2), which downregulates caspase activation and apoptosis.
Collapse
Affiliation(s)
- T O Yarovinsky
- Division of Pulmonary, Critical Care, and Occupational Medicine, Department of Internal Medicine, University of Iowa, Iowa City, Iowa 52242, USA.
| | | |
Collapse
|
16
|
Ayroldi E, Migliorati G, Bruscoli S, Marchetti C, Zollo O, Cannarile L, D'Adamio F, Riccardi C. Modulation of T-cell activation by the glucocorticoid-induced leucine zipper factor via inhibition of nuclear factor kappaB. Blood 2001; 98:743-53. [PMID: 11468175 DOI: 10.1182/blood.v98.3.743] [Citation(s) in RCA: 237] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Previously a novel gene was identified that encodes a glucocorticoid-induced leucine zipper (GILZ) whose expression is up-regulated by dexamethasone. This study analyzed the role of GILZ in the control of T-cell activation and its possible interaction with nuclear factor kappaB (NF-kappaB). Results indicate that GILZ inhibits both T-cell receptor (TCR)-induced interleukin-2/interleukin-2 receptor expression and NF-kappaB activity. In particular, GILZ inhibits NF-kappaB nuclear translocation and DNA binding due to a direct protein-to-protein interaction of GILZ with the NF-kappaB subunits. Moreover, GILZ-mediated modulation of TCR-induced responses is part of a circuit because TCR triggering down-regulates GILZ expression. These results identify a new molecular mechanism involved in the dexamethasone-induced regulation of NF-kappaB activity and T-cell activation. (Blood. 2001;98:743-753)
Collapse
Affiliation(s)
- E Ayroldi
- Department of Clinical and Experimental Medicine, Section of Pharmacology, University of Perugia, Via del Giochetto, 06100 Perugia, Italy
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Mu YM, Yanase T, Nishi Y, Takayanagi R, Goto K, Nawata H. Combined treatment with specific ligands for PPARgamma:RXR nuclear receptor system markedly inhibits the expression of cytochrome P450arom in human granulosa cancer cells. Mol Cell Endocrinol 2001; 181:239-48. [PMID: 11476957 DOI: 10.1016/s0303-7207(00)00457-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Our previous study demonstrated that PPARgamma specific ligand troglitazone (TGZ) or RXR specific ligand LG100268 (LG) alone decreased the aromatase activity in cultured human ovarian granulosa cells from pre-ovulatory follicles, and combined treatment caused an even greater reduction in this activity. Since similar manners of effects of TGZ or/and LG on the aromatase activity in human ovarian granulosa cancer cell line were observed, we performed the detailed analysis of the mechanisms of these effects using this cell line. The changes in the aromatase activity were associated with comparable changes in the P450arom mRNA levels based on a RNase protection assay. A nuclear run-on assay indicated the P450arom transcript to decrease by 40 and 66% at 24 and 48 h, respectively, after TGZ plus LG treatment. An RNA stability analysis showed the half-life of P450arom mRNA to decrease from 13 to 9 h after the TGZ plus LG treatment. The inhibitory effect of TGZ plus LG on the aromatase activity and P450arom mRNA may not be mediated by the cAMP-PKA pathway that is usually implicated in the regulation of aromatase activity in granulosa cells: because (1) the aromatase activity stimulated by forskolin was not inhibited by TGZ plus LG; (2) the specific PKA inhibitor H89 could not block the inhibitory effect of TGZ plus LG on the aromatase activity; and (3) the luciferase activity of P450arom promoter II did not decrease by the addition of TGZ and LG in transfected cells either at a basic state or in the states stimulated by forskolin or PGE2, respectively. Taken together, these results indicate that TGZ plus LG inhibited the aromatase activity and also decreased the P450arom mRNA level in granulosa cancer cells, and the loss of P450arom mRNA expression was considered to be due to both the decreased transcription and rapid degradation of its RNA.
Collapse
MESH Headings
- Aromatase/biosynthesis
- Aromatase/genetics
- Aromatase/metabolism
- Cell Division/drug effects
- Chromans/pharmacology
- Dactinomycin/pharmacology
- Dose-Response Relationship, Drug
- Down-Regulation/drug effects
- Enzyme Induction/drug effects
- Estrone/biosynthesis
- Female
- Granulosa Cell Tumor/enzymology
- Granulosa Cell Tumor/genetics
- Granulosa Cell Tumor/pathology
- Humans
- Ligands
- Nicotinic Acids/pharmacology
- Ovary/drug effects
- Ovary/enzymology
- Ovary/metabolism
- Ovary/pathology
- Promoter Regions, Genetic/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Radioimmunoassay
- Receptors, Cytoplasmic and Nuclear/agonists
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, FSH/metabolism
- Receptors, Retinoic Acid/agonists
- Receptors, Retinoic Acid/metabolism
- Retinoid X Receptors
- Tetrahydronaphthalenes/pharmacology
- Thiazoles/pharmacology
- Thiazolidinediones
- Transcription Factors/agonists
- Transcription Factors/metabolism
- Transcription, Genetic/drug effects
- Troglitazone
- Tumor Cells, Cultured
Collapse
Affiliation(s)
- Y M Mu
- Third Department of Internal Medicine, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, 812-8582, Fukuoka, Japan
| | | | | | | | | | | |
Collapse
|
18
|
Dawson MI, Hobbs PD, Jong L, Xiao D, Chao WR, Pan C, Zhang XK. sp2-bridged diaryl retinoids: effects of bridge-region substitution on retinoid X receptor (RXR) selectivity. Bioorg Med Chem Lett 2000; 10:1307-10. [PMID: 10890152 DOI: 10.1016/s0960-894x(00)00243-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
RXR class selectivity and RXR transcriptional activation activity compared to those for the retinoic acid receptor subtypes were enhanced on the 4-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenylethenyl)be nzoic acid scaffold and its 3-methyl analogue by replacing their 1,1-ethenyl bridge by a 1,1-(2-methylpropenyl) or cyclopropylidenylmethylene group.
Collapse
Affiliation(s)
- M I Dawson
- Medicinal Chemistry Department, Molecular Medicine Research Institute, Mountain View, CA 94043, USA.
| | | | | | | | | | | | | |
Collapse
|
19
|
Greene ME, Pitts J, McCarville MA, Wang XS, Newport JA, Edelstein C, Lee F, Ghosh S, Chu S. PPARgamma: observations in the hematopoietic system. Prostaglandins Other Lipid Mediat 2000; 62:45-73. [PMID: 10936415 DOI: 10.1016/s0090-6980(00)00075-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Human Peroxisome Proliferator-Activated Receptor gamma (PPARgamma) was originally cloned from a human bone marrow library. What role does this ligand activated transcription factor play in hematopoiesis and the immune system? We note that: a) PPARgamma has potential to interact/interfere or synergize with retinoid biology, b) fatty acids and a prostaglandin have been identified as ligands, and c) lymphocytes, monocytes and neutrophils use fatty acids as a major source of energy production, d) PPARgamma has been shown to oppose TNFalpha and down regulate cytokine production in monocytes. Therefore, we undertook a review of the literature and an expression survey of PPARgamma in a number of major organs and cells involved in the hematopoietic system, for the purpose of building a database towards understanding the role and function of PPARgamma gene regulation in the developing blood and immune systems. PPARgamma is expressed before mesodermal induction in tissue in and around Speymann's organizer in the xenopus blastocyst, in erythroid precursors of blood islands and in the circulation of the day 10.0 murine embryo, in human 19 week fetal liver, in some but not all murine and human bone marrow erythroid, myeloid, and monocytoid progenitors, bone marrow stromal cells and adipocytes, osteoblasts, endothelial cells, some T, and B lymphocytes, monocytes, macrophages, and other monocytic derivatives. It can be found in the cells of Peyer's patches, lymphoid follicles, spleen, and thymus. It is not clear if it is ever or transiently expressed in megakaryocytes, mast cells, or neutrophils. Based on the above data and a review of the literature, PPARgamma seems to play a role during the elicitation of immune responses. We propose PPARgamma may be involved in changes in energy states required during activation and development of many cell types involved, and has additional immunologically relevant effects in erythroid, myeloid, monocytic, T and B lymphocytic, stromal, and endothelial cell function.
Collapse
Affiliation(s)
- M E Greene
- Department of Cancer Biology/Pathology, Children's Memorial Institute for Education and Research (CMIER), Chicago, IL 60614, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Kang HJ, Song MR, Lee SK, Shin EC, Choi YH, Kim SJ, Lee JW, Lee MO. Retinoic acid and its receptors repress the expression and transactivation functions of Nur77: a possible mechanism for the inhibition of apoptosis by retinoic acid. Exp Cell Res 2000; 256:545-54. [PMID: 10772826 DOI: 10.1006/excr.2000.4832] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Nur77 (NGFI-B) is an orphan nuclear receptor that has been implicated in activation-induced T-cell apoptosis. Retinoids, potent immune modulators, were shown to inhibit the activation-induced apoptosis of immature thymocytes and T-cell hybridomas. To illustrate the mechanism of the inhibition, we examined the effects of retinoic acid (RA) on the expression and transactivation functions of Nur77 in the human peripheral blood mononuclear cells and the human T-cell leukemia, Jurkat. All-trans-RA remarkably repressed the DNA binding and transcriptional induction of Nur77. Among the two potential trans-acting factors that activate Nur77 gene promoter, i.e., AP-1 and related serum response factor (RSRF), all-trans-RA repressed DNA binding and reporter gene activity of AP-1 but not that of RSRF, suggesting that the inhibition may be mediated through AP-1. We also demonstrated a posttranscriptional regulation of Nur77 function by retinoid receptors by showing that transactivation activity of Nur77 was significantly inhibited by cotransfection of RARalpha or RXRalpha. Nur77 bound RARalpha or RXRalpha in both yeast and mammalian two-hybrid tests, suggesting that direct protein-protein interaction between these receptors may mediate the inhibition. Taken all together, we demonstrated that RA repressed Nur77 function through multiple mechanisms that may provide the basis for RA inhibition on the apoptosis of activated T-lymphocytes.
Collapse
Affiliation(s)
- H J Kang
- Department of Microbiology, Yonsei University College of Medicine, Seoul, 120-752, Korea
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Moreno-Manzano V, Ishikawa Y, Lucio-Cazana J, Kitamura M. Suppression of apoptosis by all-trans-retinoic acid. Dual intervention in the c-Jun n-terminal kinase-AP-1 pathway. J Biol Chem 1999; 274:20251-8. [PMID: 10400643 DOI: 10.1074/jbc.274.29.20251] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Retinoic acid induces apoptosis of various cells, whereas little is known about its anti-apoptotic potential. In this report, we describe an anti-apoptotic property of all-trans-retinoic acid (t-RA) in mammalian cells. Mesangial cells exposed to hydrogen peroxide (H2O2) exhibited shrinkage of the cytoplasm, membrane blebbing, condensation of nuclei, and DNA fragmentation. Pretreatment with t-RA attenuated the morphologic and biochemical hallmarks of apoptosis. t-RA also inhibited apoptosis of mesangial cells triggered by pyrrolidine dithiocarbamate, whereas it did not prevent tumor necrosis factor-alpha-induced apoptosis. The anti-apoptotic effect against H2O2 was similarly observed in NRK49F fibroblasts, but not in Madin-Darby canine kidney epithelial cells and ECV304 endothelial cells. Mesangial cells exposed to H2O2 undergo apoptosis via the activator protein 1 (AP-1)-dependent pathway. We found that t-RA abrogated the H2O2-induced expression of c-fos/c-jun and activation of AP-1. Furthermore, t-RA inhibited H2O2-triggered activation of c-Jun N-terminal kinase (JNK), and dominant-negative inhibition of JNK attenuated the H2O2-induced apoptosis. These data disclosed the novel potential of retinoic acid as an inhibitor of apoptosis. The anti-apoptotic action of t-RA was ascribed, at least in part, to dual suppression of the cell death pathway mediated by JNK and AP-1.
Collapse
Affiliation(s)
- V Moreno-Manzano
- Glomerular Bioengineering Unit, Department of Medicine, University College London Medical School, The Rayne Institute, 5 University Street, London WC1E 6JJ, United Kingdom
| | | | | | | |
Collapse
|
22
|
Furuke K, Shiraishi M, Mostowski HS, Bloom ET. Fas Ligand Induction in Human NK Cells Is Regulated by Redox Through a Calcineurin-Nuclear Factors of Activated T Cell-Dependent Pathway. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.4.1988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Fas ligand (FasL) on cytotoxic lymphocytes is important for mediating apoptosis of activated lymphocytes and other target cells. We have reported that NK cell functions, such as proliferation, cell death, and killing activity, are subject to regulation by cellular redox status. Here, we report that expression of FasL protein and mRNA in activated NK cells is also regulated by redox. Ligation of CD16 on IL-2-preactivated NK cells resulted in reduction of intracellular peroxide level as well as induction of FasL expression. This CD16-induced FasL expression was suppressed by oxidative stress, including thiol deprivation or treatment with hydrogen peroxide (H2O2). Addition of thiol-reducing compounds, such as l-cystine, 2-ME, or N-acetyl cysteine, restored FasL expression. These data suggest that CD16 stimulation requires cellular reducing status for FasL induction in NK cells. Because FasL gene activation following CD16 cross-linking is regulated by the NF of activated T cells (NFAT), we examined the effect of oxidative stresses on NFAT activation. Electrophoretic mobility shift assays revealed that both thiol insufficiency and H2O2 treatment suppressed DNA-binding activity of NFAT and that addition of thiol-reducing compounds reversed or even enhanced it. Furthermore, these oxidative stresses inhibited activity of calcineurin, a serine/threonine phosphatase that regulates NFAT activation. These results suggest that suppression of calcineurin and NFAT activation is a mechanism by which oxidative stress inhibits FasL induction in activated NK cells and further support the hypothesis that thiol-reducing compounds might be required for maintenance of optimal NK functions under physiologic oxidative conditions.
Collapse
Affiliation(s)
- Keizo Furuke
- Laboratory of Cellular Immunology, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892
| | - Mitsuhiro Shiraishi
- Laboratory of Cellular Immunology, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892
| | - Howard S. Mostowski
- Laboratory of Cellular Immunology, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892
| | - Eda T. Bloom
- Laboratory of Cellular Immunology, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892
| |
Collapse
|
23
|
Mittelstadt PR, Ashwell JD. Role of Egr-2 in up-regulation of Fas ligand in normal T cells and aberrant double-negative lpr and gld T cells. J Biol Chem 1999; 274:3222-7. [PMID: 9915863 DOI: 10.1074/jbc.274.5.3222] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We previously identified a Fas ligand regulatory element (FLRE) in the Fas ligand (fasL) promoter that binds Egr family proteins and demonstrated that Egr-3 (PILOT) but not Egr-1 (NGFI-A, Krox-24, Tis-8, and Zif-268) induces transcription of fasL. The aberrant CD4(-)CD8(-) T cells from lpr/lpr and gld/gld mice, which have mutations in the genes encoding Fas and FasL, respectively, have an activated phenotype and constitutively express high levels of fasL mRNA, prompting us to ask what role if any the FLRE and Egr family proteins have in this aberrant expression of fasL. Unstimulated MRL-lpr/lpr and C3H-gld/gld CD4(-)CD8(-) T cells constitutively contained high levels of two proteins that bound to the FLRE. Supershift analysis revealed these proteins to be Egr-1 and Egr-2 (Krox-20); Egr-3 was not detected. Activation of normal lymph node cells resulted in increased expression of Egr-1, -2, and -3. As with egr-3, expression of egr-2 was blocked by cyclosporin A. Although overexpressed Egr-1 was ineffective, overexpressed Egr-2 was as potent as Egr-3 in inducing fasL promoter-dependent reporter constructs in T cell hybridomas and HeLa cells, and both up-regulated endogenous fasL mRNA in HeLa cells. FasL-dependent reporter constructs in MRL-lpr/lpr and C3H-gld/gld CD4(-)CD8(-) T cells were constitutively active, and this activity was largely prevented by mutation of the critical Egr family binding element. Thus, Egr-2, in addition to Egr-3, regulates FasL expression in activated normal T cells, and Egr-2 is likely to play a direct role in aberrant fasL up-regulation in lpr/lpr and gld/gld CD4(-)CD8(-) T cells.
Collapse
Affiliation(s)
- P R Mittelstadt
- Laboratory of Immune Cell Biology, NCI, National Institutes of Health, Bethesda, Maryland 20892-1152, USA
| | | |
Collapse
|
24
|
Solomin L, Johansson CB, Zetterström RH, Bissonnette RP, Heyman RA, Olson L, Lendahl U, Frisén J, Perlmann T. Retinoid-X receptor signalling in the developing spinal cord. Nature 1998; 395:398-402. [PMID: 9759732 DOI: 10.1038/26515] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Retinoids regulate gene expression through the action of retinoic acid receptors (RARs) and retinoid-X receptors (RXRs), which both belong to the family of nuclear hormone receptors. Retinoids are of fundamental importance during development, but it has been difficult to assess the distribution of ligand-activated receptors in vivo. This is particularly the case for RXR, which is a critical unliganded auxiliary protein for several nuclear receptors, including RAR, but its ligand-activated role in vivo remains uncertain. Here we describe an assay in transgenic mice, based on the expression of an effector fusion protein linking the ligand-binding domain of either RXR or RAR to the yeast Gal4 DNA-binding domain, and the in situ detection of ligand-activated effector proteins by using an inducible transgenic lacZ reporter gene. We detect receptor activation in the spinal cord in a pattern that indicates that the receptor functions in the maturation of limb-innervating motor neurons. Our results reveal a specific activation pattern of Gal4-RXR which indicates that RXR is a critical bona fide receptor in the developing spinal cord.
Collapse
Affiliation(s)
- L Solomin
- The Ludwig Institute for Cancer Research, Stockholm Branch, Sweden
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Müschen M, Warskulat U, Schmidt B, Schulz WA, Häussinger D. Regulation of CD95 (Apo-1/Fas) ligand and receptor expression in human embryonal carcinoma cells by interferon gamma and all-trans retinoic acid. Biol Chem 1998; 379:1083-91. [PMID: 9792441 DOI: 10.1515/bchm.1998.379.8-9.1083] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Expression of CD95 (Apo-1/Fas) ligand and its two receptor isoforms, in response to all-trans retinoic acid and interferon gamma (IFNgamma), was analyzed atthe mRNA and protein levels in human Tera-2 embryonal carcinoma cells. Exposure of Tera-2 cells to all-trans retinoic acid for up to 16 days led to a decrease of CD95 ligand expression when compared to the control conditions, whereas expression of both CD95 isoforms increased. These changes were functionally significant since Tera-2 cells treated with all-trans retinoic acid for six to 16 days were more susceptible to CD95-mediated apoptosis. On the other hand, Tera-2 cells lost their capacity to induce apoptosis in CD95 receptor bearing Jurkat T lymphocytes after six days of incubation with all-trans retinoic acid. When Tera-2 cells were treated with IFNgamma, expression of CD95 ligand and both CD95 receptor isoforms increased within 24 hours. Tera-2 cells were then more susceptible to CD95 mediated apoptosis but also killed more CD95 receptor bearing Jurkat T lymphocytes via CD95 ligation compared to the control conditions. The results are indicative of differential regulation of CD95-mediated apoptosis by all-trans retinoic acid and IFNgamma in Tera-2 embryonal carcinoma cells, with likely impact on antitumor immunity.
Collapse
Affiliation(s)
- M Müschen
- Klinik für Gastroenterologie, Hepatologie und Infektiologie, Heinrich-Heine-Universität, Düsseldorf, Germany
| | | | | | | | | |
Collapse
|
26
|
Liu R, Takayama S, Zheng Y, Froesch B, Chen GQ, Zhang X, Reed JC, Zhang XK. Interaction of BAG-1 with retinoic acid receptor and its inhibition of retinoic acid-induced apoptosis in cancer cells. J Biol Chem 1998; 273:16985-92. [PMID: 9642262 DOI: 10.1074/jbc.273.27.16985] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
BAG-1 (also known as RAP46) is an anti-apoptotic protein, which has been shown previously to interact with a number of nuclear hormone receptors, including receptors for glucocorticoid, estrogen, and thyroid hormone. We show here that BAG-1 also interacts with retinoic acid receptor (RAR). Gel retardation assays demonstrated that in vitro translated BAG-1 protein could effectively inhibit the binding of RAR but not retinoid X receptor (RXR) to a number of retinoic acid (RA) response elements (RAREs). A glutathione S-transferase-BAG-1 fusion protein also specifically bound RAR but not RXR. Interaction of BAG-1 and RAR could also be demonstrated by yeast two-hybrid assays. In transient transfection assays, co-transfection of BAG-1 expression plasmid inhibited the transactivation activity of RAR/RXR heterodimers but not RXR/RXR homodimers. When stably expressed in breast cancer cell lines, BAG-1 inhibited binding of RAR/RXR heterodimer to a number of RAREs and suppressed RA-induced growth inhibition and apoptosis. In addition, RA-induced suppression of Bcl-2 expression was abrogated by overexpression of BAG-1. These results demonstrate that BAG-1 can regulate retinoid activities through its interaction with RAR and suggest that elevated levels of BAG-1 protein could potentially contribute to retinoid resistance in cancer cells.
Collapse
Affiliation(s)
- R Liu
- The Burnham Institute, Cancer Research Center, La Jolla, California 92037, USA
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Fujimura S, Suzumiya J, Anzai K, Ohkubo K, Hata T, Yamada Y, Kamihira S, Kikuchi M, Ono J. Retinoic acids induce growth inhibition and apoptosis in adult T-cell leukemia (ATL) cell lines. Leuk Res 1998; 22:611-8. [PMID: 9680111 DOI: 10.1016/s0145-2126(98)00049-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Adult T-cell leukemia (ATL) is a peripheral T-cell neoplasm caused by human T-cell leukemia virus type I (HTLV-I). Despite the administration of combined intensive chemotherapy, the reported survival time of patients with acute and lymphoma types of ATL is less than 10 months. We therefore examine the effects of all-trans-retinoic acid (ATRA), 9-cis-RA and 13-cis-RA and tried to elucidate the mechanisms of inducing growth inhibition and apoptosis by these RAs using four ATL cell lines established in our laboratory. All the investigated RAs inhibited cell growth and the cells were arrested at the G1 phase. Apoptosis was induced in three out of four cell lines. Among the growth regulatory proteins examined, the level of p21Waf1/Cip1 protein was found to increase after RA treatment, thus resulting in pRb hypophosphorylation which also induced the arrest of the cells at the G1 phase. In addition, the p53 level decreased at the same time. Fas-FasL system and the downregulation of CD25 (IL-2R/alpha) expression did not seem to be involved. Based on these findings, the ability of RAs to induce a remission of ATL is thus strongly suggested.
Collapse
Affiliation(s)
- S Fujimura
- Department of Laboratory Medicine, Fukuoka University School of Medicine, Nanakuma, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Szondy Z, Reichert U, Bernardon JM, Michel S, Tóth R, Karászi E, Fésüs L. Inhibition of activation-induced apoptosis of thymocytes by all-trans- and 9-cis-retinoic acid is mediated via retinoic acid receptor alpha. Biochem J 1998; 331 ( Pt 3):767-74. [PMID: 9560303 PMCID: PMC1219416 DOI: 10.1042/bj3310767] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
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.
Collapse
Affiliation(s)
- Z Szondy
- Department of Biochemistry, University Medical School of Debrecen, H-4012 Debrecen, Hungary.
| | | | | | | | | | | | | |
Collapse
|
29
|
Lømo J, Smeland EB, Ulven S, Natarajan V, Blomhoff R, Gandhi U, Dawson MI, Blomhoff HK. RAR-, not RXR, ligands inhibit cell activation and prevent apoptosis in B-lymphocytes. J Cell Physiol 1998; 175:68-77. [PMID: 9491782 DOI: 10.1002/(sici)1097-4652(199804)175:1<68::aid-jcp8>3.0.co;2-a] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We have previously shown that retinoids inhibit activation of human peripheral blood B-lymphocytes. In the present paper, we wished to explore the involvement of nuclear retinoid-specific receptors in this process by using ligands specific for the retinoic acid receptors (RARs) and retinoid X receptors (RXRs). We found that the RAR-specific ligand TTAB reduced anti-IgM-induced B-cell activation in a dose-dependent manner. Thus, at 100 nM of TTAB, DNA synthesis was reduced by approximately 60%. In contrast, the RXR-selective ligand SR11217 had no effect on DNA synthesis. Similar findings were obtained when the expression of the activation antigen CD71 (appears late in G1) was examined. The role of retinoids in apoptosis of resting peripheral blood B-lymphocytes was examined using the same receptor-selective ligands. Again, we found that the RAR-selective ligands were more potent effectors than were the RXR-selective ligands. In spite of the inhibitory effects of retinoids on B-cell proliferation, the same retinoids significantly promoted the survival of the cells. Thus, 10 nM TTAB significantly reduced spontaneous apoptosis of in vitro cultured B-cells at day 3 from 45% to 30%, as determined by vital dye staining and DNA end-labeling. Again, the RXR-specific ligand SR11217 had no effect. Interestingly, we found that CD40 ligand was able to potentiate the retinoid-mediated inhibition of apoptosis. By reverse transcriptase polymerase chain reaction (PCR), we found that peripheral blood B-lymphocytes expressed RARalpha, RARgamma, and RXRalpha, but not RARbeta, RXRbeta, or RXRgamma. Hence, the lack of effect of the RXR-specific ligand SR11217 on growth and apoptosis was not due to absence of RXRs. In conclusion, the ability of retinoids to inhibit growth and prevent apoptosis of normal human B-lymphocytes indicates a dual role of retinoids in this cell compartment, and it appears that both effects of retinoids are mediated via RARs and not RXRs.
Collapse
Affiliation(s)
- J Lømo
- Department of Immunology, Institute for Cancer Research, The Norwegian Radium Hospital, Montebello, Oslo
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Gaál A, Bocsi J, Falus A, Szende B, Csaba G. Increased apoptosis of adult rat lymphocytes after single neonatal vitamin A treatment (hormonal imprinting). A flow cytometric analysis. Life Sci 1998; 61:PL339-42. [PMID: 9408059 DOI: 10.1016/s0024-3205(97)00940-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Newborn rats were treated with a single dose of vitamin A (retinol) and apoptosis of peripheral lymphocytes was studied by flow cytometry in adult age. Vitamin A treatment (hormonal imprinting) caused a moderate, however significant elevation in the number of apoptotic lymphocytes after three months. Dexamethasone or Concanavalin-A alone did not influence apoptosis significantly. However, in the neonatally retinol treated rats dexamathasone significantly elevated the quantity of apoptotic lymphocytes related to the control or Concanavalin-A treated control cells. The results call attention to the prolonged effect of hormonal imprinting in a new index and to the possible dangerous effects in human, neonatally treated with vitamin A.
Collapse
Affiliation(s)
- A Gaál
- Department of Genetics, Cell and Immunobiology, Semmelweis University of Medicine, Budapest, Hungary
| | | | | | | | | |
Collapse
|
31
|
D'Adamio F, Zollo O, Moraca R, Ayroldi E, Bruscoli S, Bartoli A, Cannarile L, Migliorati G, Riccardi C. A new dexamethasone-induced gene of the leucine zipper family protects T lymphocytes from TCR/CD3-activated cell death. Immunity 1997; 7:803-12. [PMID: 9430225 DOI: 10.1016/s1074-7613(00)80398-2] [Citation(s) in RCA: 340] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
By comparing mRNA species expressed in dexamethasone (DEX)-treated and untreated murine thymocytes, we have identified a gene, glucocorticoid-induced leucine zipper (GILZ), encoding a new member of the leucine zipper family. GILZ was found expressed in normal lymphocytes from thymus, spleen, and lymph nodes, whereas low or no expression was detected in other nonlymphoid tissues, including brain, kidney, and liver. In thymocytes and peripheral T cells, GILZ gene expression is induced by DEX. Furthermore, GILZ expression selectively protects T cells from apoptosis induced by treatment with anti-CD3 monoclonal antibody but not by treatment with other apoptotic stimuli. This antiapoptotic effect correlates with inhibition of Fas and Fas ligand expression. Thus, GILZ is a candidate transcription factor involved in the regulation of apoptosis of T cells.
Collapse
Affiliation(s)
- F D'Adamio
- Department of Clinical Medicine, Pathology and Pharmacology, University of Perugia, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Kersten S, Reczek PR, Noy N. The tetramerization region of the retinoid X receptor is important for transcriptional activation by the receptor. J Biol Chem 1997; 272:29759-68. [PMID: 9368046 DOI: 10.1074/jbc.272.47.29759] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The retinoid X receptor (RXR), a member of the superfamily of hormone nuclear receptors, is a ligand-inducible transcription factor that is activated by the vitamin A derivative 9-cis-retinoic acid. We previously showed that RXR self-associates into tetramers with a high affinity and that ligand binding induces rapid dissociation of receptor tetramers to smaller species. Here, the RXR region that is responsible for mediating tetramer formation is identified. It is shown that this interface, which we term the "tetramerization domain," critically contains two consecutive phenylalanine residues located at the C-terminal region of the receptor. Mutation of these residues is sufficient to disrupt RXR tetramers without affecting the overall fold of the protein or interfering with ligand binding, dimer formation, or DNA binding by the receptor. Nevertheless, the tetramer-impaired mutant was found to be transcriptionally defective. The newly characterized tetramerization domain and the previously identified main dimerization interface of RXR act autonomously to affect separate intersubunit interactions that, overall, lead to formation of tetramers. Protein-protein interactions mediated by the tetramerization domain, but not those that involve the dimerization interface, are disrupted following ligand binding by RXR. Overall, these data attest to the specificity of the interaction and implicate the tetramerization interface in playing a direct role in regulating transcriptional activation by RXR.
Collapse
Affiliation(s)
- S Kersten
- Cornell University, Division of Nutritional Sciences, Savage Hall, Ithaca, New York 14853-6301, USA
| | | | | |
Collapse
|
33
|
Affiliation(s)
- M B Rogers
- Department of Biology, University of South Florida Tampa 33620-5150, USA
| |
Collapse
|
34
|
Abstract
While it is generally believed that the avidity of the T cell antigen receptor (TCR) for self antigen/major histocompatibility complex (MHC) determines a thymocyte's fate, how the cell discriminates between a stimulus that causes positive selection (survival) and one that causes negative selection (death) is unknown. We have previously demonstrated that glucocorticoids are produced in the thymus, and that they antagonize deletion caused by TCR cross-linking. To examine the role of glucocorticoids during MHC-dependent selection, we examined thymocyte development in organ cultures in which corticosteroid biosynthesis was inhibited. Inhibition of glucocorticoid production in thymi from alpha/beta-TCR transgenic mice resulted in the antigen- and MHC-specific loss of thymocytes that normally recognize self antigen/MHC with sufficient avidity to result in positive selection. Furthermore, inhibition of glucocorticoid production caused an increase in apoptosis only in CD+CD8(+) thymocytes bearing transgenic TCRs that recognized self antigen/MHC. These results indicate that the balance of TCR and glucocorticoid receptor signaling influences the antigen-specific thymocyte development by allowing cells with low-to-moderate avidity for self antigen/MHC to survive.
Collapse
Affiliation(s)
- M S Vacchio
- Laboratory of Immunology, Division of Hematologic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20852, USA
| | | |
Collapse
|
35
|
Allende LM, Corell A, Madroño A, Góngora R, Rodríguez-Gallego C, López-Goyanes A, Rosal M, Arnaiz-Villena A. Retinol (vitamin A) is a cofactor in CD3-induced human T-lymphocyte activation. Immunol Suppl 1997; 90:388-96. [PMID: 9155646 PMCID: PMC1456614 DOI: 10.1111/j.1365-2567.1997.00388.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Immunomodulatory effects of different retinoids have been demonstrated, both in vivo and in vitro, in different cellular lineages including human and murine thymocytes, human lung fibroblasts, Langerhans' cells, tumoral cells and natural killer (NK) cells; however, any attempt to demonstrate the effect of retinoids on human peripheral blood mononuclear cells (PBMC) resulted in negative results. In the present work, it is shown that retinol and retinoic acid induce a marked increase of proliferation on human PBMC from 32 unrelated healthy individuals, which had previously been stimulated with anti-CD3 antibodies 48 hr before. Serum-free medium, specific retinoid concentration (10(-7) M) and a particular timing of retinol addition to the cultures (48 hr after CD3 stimulation) was necessary clearly to detect this retinol-enhancing effect. The increased proliferative response is specifically mediated via the clonotipic T-cell receptor-CD3 complex and correlates with the up-regulation of certain adhesion/activation markers on the T-lymphocyte surface: CD18, CD45RO and CD25; also Th1-type of cytokines (interleukin-2 and interferon-gamma) are found concordantly increased after retinoid costimulation, both measured by a direct protein measurement and by a specific mRNA increase. In addition, it is shown that the in vitro retinol costimulation is only present in immunodeficient patients who have no defect on CD3 molecules and activation pathway. The fact that retinol costimulate lymphocytes only via CD3 (and not via CD2 or CD28) and the lack of response enhancement in immunodeficients with impaired CD3 activation pathway indicates that retinoids may be used as therapeutic agents in immune system deficiencies that do not affect the clonotypic T-cell receptor.
Collapse
Affiliation(s)
- L M Allende
- Department of Immunology, Hospital Universitario 12 de Octubre, Universidad Complutense, Carretera de Andalucía, Madrid, Spain
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Minucci S, Leid M, Toyama R, Saint-Jeannet JP, Peterson VJ, Horn V, Ishmael JE, Bhattacharyya N, Dey A, Dawid IB, Ozato K. Retinoid X receptor (RXR) within the RXR-retinoic acid receptor heterodimer binds its ligand and enhances retinoid-dependent gene expression. Mol Cell Biol 1997; 17:644-55. [PMID: 9001218 PMCID: PMC231790 DOI: 10.1128/mcb.17.2.644] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Retinoic acid receptor (RAR) and retinoid X receptor (RXR) form heterodimers and regulate retinoid-mediated gene expression. We studied binding of RXR- and RAR-selective ligands to the RXR-RAR heterodimer and subsequent transcription. In limited proteolysis analyses, both RXR and RAR in the heterodimer bound their respective ligands and underwent a conformational change in the presence of a retinoic acid-responsive element. In reporter analyses, the RAR ligand (but not the RXR ligand), when added singly, activated transcription, but coaddition of the two ligands led to synergistic activation of transcription. This activation required the AF-2 domain of both RXR and RAR. Genomic footprinting analysis was performed with P19 embryonal carcinoma cells, in which transcription of the RARbeta gene is induced upon retinoid addition. Paralleling the reporter activation data, only the RAR ligand induced in vivo occupancy of the RARbeta2 promoter when added singly. However, at suboptimal concentrations of RAR ligand, coaddition of the RXR ligand increased the stability of promoter occupancy. Thus, liganded RXR and RAR both participate in transcription. Finally, when these ligands were tested for teratogenic effects on zebra fish and Xenopus embryos, we found that coadministration of the RXR and RAR ligands caused more severe abnormalities in these embryos than either ligand alone, providing biological support for the synergistic action of the two ligands.
Collapse
Affiliation(s)
- S Minucci
- Laboratory of Molecular Growth Regulation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Retinoids and Apoptosis. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s1569-2590(08)60056-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
38
|
Abstract
Our understanding of the mechanism of action of retinoids has been greatly expanded by a series of recent findings. First, the three-dimensional structure of the ligand-binding domain of two retinoid receptors has been solved and suggests that ligand binding induces marked allosteric changes. Second, several co-factors interacting with the receptors have been cloned, some of which are capable of regulating the function of receptors. Third, the advent of synthetic retinoids helped define the activities of the receptors. Fourth, the study of the in vivo receptor-DNA interactions has revealed a previously unrecognized role of the ligand in regulating the stability of receptor-DNA complexes. These advances have revealed complex molecular interactions operating at multiple levels, opening new avenues of research for addressing their mechanisms.
Collapse
Affiliation(s)
- S Minucci
- Laboratory of Molecular Growth Regulation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
| | | |
Collapse
|
39
|
|
40
|
Smith ML, Fornace AJ. Mammalian DNA damage-inducible genes associated with growth arrest and apoptosis. Mutat Res 1996; 340:109-24. [PMID: 8692176 DOI: 10.1016/s0165-1110(96)90043-3] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Mammalian cells are exposed to a wide variety of genotoxic stresses from both endogenous and exogenous sources. Cells typically exhibit cell cycle delays, or checkpoints, in response to acute genotoxic stress. Other types of cellular responses to DNA damage include apoptosis and probably increases in DNA repair levels. These response pathways are altered in cancer cells, by genetic alterations such as overexpression or mutation of oncogenes, or loss of tumor suppressor gene functions. As cancer chemotherapy relies primarily on the selective killing of cancer cells by DNA-damaging agents, genetic alterations affecting cellular stress response pathways may affect the outcome of cancer treatment.
Collapse
Affiliation(s)
- M L Smith
- Laboratory of Molecular Pharmacology, National Cancer Institute, Bethesda, MD 20892, USA.
| | | |
Collapse
|