9-cis retinoic acid modulates the type I allergic immune response

1. Download high-res image (245KB)
2. Download full-size image

     

Quantitative axial profiles of retinoic acid in the embryonic mouse spinal cord: 9-cis retinoic acid only detected after all-trans-retinoic acid levels are super-elevated experimentally.

Studies using bioassays in normal mice and gene activation in transgenic reporter mice have demonstrated peaks of retinoic acid receptor (RAR) signaling in the brachial and lumbar regions of the spinal cord. Recently, Solomin et al. (Solomin et al. [1998] Nature 395:398-402) detected a retinoid X receptor (RXR) signal in the same region of the developing spinal cord at a slightly later stage than the RAR signal. This finding raises the question of which retinoid ligands underlie RAR and RXR signaling in this part of the embryo. Quantitative measurements of regional differences in retinoid profiles have not been reported previously due to limitation in the sensitivity and specificity of available retinoid detection methods. Here, by using a recently developed ultrasensitive HPLC technique (Sakhi et al. [1998] J. Chromatogr. A 828:451-460), we address this question in an attempt to identify definitively the endogenous retinoids present in different regions of the spinal cord at the stages when regional differences in RAR and RXR signaling have been reported. We find a bimodal distribution of all-trans retinoic acid (at-RA), the ligand for RARs, and relate this to the expression of several retinoid-synthesizing enzymes. However, we do not detect 9-cis-retinoic acid (9-cis-RA), the putative RXR ligand, in any region of the spinal cord unless retinoid levels are massively increased experimentally by gavage feeding pregnant mice with teratogenic doses of at-RA. This study provides for the first time quantitative profiles of endogenous retinoids along the axis of the developing spinal cord, thereby establishing a foundation for more definitive studies of retinoid function in the future. It sets definite limits on how much 9-cis-RA potentially is present and demonstrates that at-RA predominates over 9-cis-RA by at least 30- to 180-fold in different spinal cord regions.     

13-cis retinoic acid inhibits development and progression of chronic allograft nephropathy

Chronic allograft nephropathy is characterized by chronic inflammation and fibrosis. Because retinoids exhibit anti-proliferative, anti-inflammatory, and anti-fibrotic functions, the effects of low and high doses of 13-cis-retinoic acid (13cRA) were studied in a chronic Fisher344-->Lewis transplantation model. In 13cRA animals, independent of dose (2 or 20 mg/kg body weight/day) and start (0 or 14 days after transplantation) of 13cRA administration, serum creatinine was significantly lower and chronic rejection damage was dramatically reduced, including subendothelial fibrosis of preglomerular vessels and chronic tubulointerstitial damage. The number of infiltrating mononuclear cells and their proliferative activity were significantly diminished. The mRNA expression of chemokines (MCP-1/CCL2, MIP-1alpha/CCL3, IP-10/CXCL10, RANTES/CCL5) and proteins associated with fibrosis (plasminogen activator inhibitor-1, transforming growth factor-beta1, and collagens I and III) were strikingly lower in treated allografts. In vitro, activated peritoneal macrophages of 13cRA-treated rats showed a pronounced decrease in protein secretion of inflammatory cytokines (eg, tumor necrosis factor-alpha, interleukin-6). The suppression of the proinflammatory chemokine RANTES/CCL5 x 13cRA in fibroblasts could be mapped to a promoter module comprising IRF-1 and nuclear factor-kappaB binding elements, but direct binding of retinoid receptors to promoter elements could be excluded. In summary, 13cRA acted as a potent immunosuppressive and anti-fibrotic agent able to prevent and inhibit progression of chronic allograft nephropathy.     

13-cis retinoic acid enhances in vivo B-lymphocyte differentiation in patients with common variable immunodeficiency.

Retinoic acid (RA) has been demonstrated to drive both phenotypic and functional in vitro differentiation of B cell hybridomas from patients with common variable immunodeficiency (CVI) who manifest an "intrinsic" defect in terminal B cell differentiation (J Exp Med 1988;168: 55-71). Therefore, we conducted an open trial to determine the effects of oral 13-cis RA (0.5 mg/kg/day; 12 weeks receiving and 12 weeks without drug) on in vivo B cell differentiation in subjects with CVI. At various times before, during, and after drug administration, patients' B cells were tested for changes in cell-surface phenotype and in vitro immunoglobulin production in response to recombinant cytokines. Before 13-cis RA, all patients had decreased Leu-8 coexpression on CD20+ cells. Seven of eight subjects demonstrated "normalization" of this phenotype after 8 to 16 weeks of 13-cis RA administration. Patients whose B cells demonstrated more than normal CD20 display also had a fall toward normal in this parameter. These effects persisted for 6 to 12 weeks after drug was stopped. It appears that 13-cis RA drives B cells of patients with CVI to express a more differentiated cell-surface phenotype and may promote functional differentiation in some patients.     

Herceptin联合9-顺式视黄酸对ErbB2阳性乳腺癌细胞的抑制作用及其相关分子机制的研究

目的 探讨Herceptin联合9-顺式视黄酸对ErbB2阳性乳腺癌细胞的协同增殖抑制效应及其分子机制.方法 利用MTT法检测经Herceptin、9-顺式视黄酸单独和联合作用后HER2/neu阳性的MDA-MB-453乳腺癌细胞的增殖活性的变化,在此基础上,利用免疫印记和半定量PCR法对HER2/neu、RXR以及COX-2的表达进行检测,同时利用ELISA法检测细胞培养上清内PGE-2的水平变化.结果 一定剂量的Herceptin和9-顺式视黄酸能够有效协同抑制MDA-MB-453细胞的增殖活性.经二者联合作用后,磷酸化、非磷酸化的ErbB2以及COX-2的表达较对照组均显著下降,而RXRα的表达则无明显变化.同时,二者联合作用还能有效降低细胞PGE-2的分泌水平.结论 Herceptin和9-顺式视黄酸可在体外分别通过抑制HER2/neu 和COX-2的表达和活性来达到协同抑制HER2/neu阳性乳腺癌的作用.     

Myeloid surface antigen abnormalities in myelodysplasia: relation to prognosis and modification by 13-cis retinoic acid.

The relation between prognosis and lineage specific surface antigen expression on peripheral blood granulocytes and monocytes was studied using monoclonal antibodies and flow cytometry in 37 patients with myelodysplastic syndromes (MDS). Abnormalities in antigen expression were summarised as a score, and cases were divided into low (few abnormalities) and high (many abnormalities) groups. Survival was significantly worse in the "high" group (logrank chi 2 = 5.793, p = 0.016), this group having a median survival of 31 weeks, compared with more than 67 weeks in the "low" group. No correlations were found between the score and any of the following: peripheral blood platelet and granulocyte count; FAB subtype; bone marrow blast cells and sideroblast count, or erythroid and myeloid progenitor growth. Antigen expression was also studied in six further cases of MDS before and after six weeks of treatment with 13-cis retinoic acid (CRA), 20 mg given orally, and a comparison was made with six untreated patients studied before and after a similar time interval. In the treated group 58% of initially abnormal measurements reverted to normal, compared with 24% in the untreated group. Five of the six treated patients showed a decrease in the score, whereas only two of the six improved in the untreated group. The data indicate that myeloid antigen expression is a useful indicator of prognosis in MDS, and that antigen expression may be affected by treatment.     

In vitro inhibition of head and neck cancer-cell growth by human recombinant interferon-alpha and 13-cis retinoic acid.

Three nasopharyngeal carcinoma (NPC) cell lines (CNE-1, CNE-2 and NPC/HK-1), two squamous cell carcinoma (SCC) cell lines (T2/CUHK and PWH-S1) and six head and neck cancer specimens (NPC [n = 4], SCC tongue [n = 1] and a thyroid cancer [n = 1]) were incubated with interferon (IFN)-alpha (5 x 10(4) iu/mL) and/or 13-cis retinoic acid (13RA; 10(-5) mol/L) for two days at 37 degrees C. In vitro chemosensitivity was measured using MTT assay. Mild growth inhibition of the five cell lines by IFN-alpha ranged from 7.1% to 51.8% (mean: 18.5%), whereas with 13RA it was zero to 19.7% (mean: 7%). Greater inhibition (14.8-51.0%, mean: 31.8%) was achieved when the two drugs were used in combination. Growth inhibition of the six surgical specimens ranged from 6.9% to 21% (mean: 13.6%) with IFN-alpha; zero to 10.3% (mean: 6.0%) with 13RA; and 6.6-26.5% (mean: 17.7%) when the two agents were combined. Four of the 11 samples showed synergistic antitumour effect when IFN-alpha and 13RA were combined, and six showed subadditive effect. The results show that IFN-alpha and 13RA have a mild in vitro antitumour effect on head and neck cancer cells, and the drug synergistic effect demonstrated in this study suggests that the two agents should be used in combination in clinical application.     

Growth of tumor colonies mediated by phorbol ester and 13-cis retinoic acid in mixed cultures

The aim of the study was to investigate the influence of the substances modifying cell phenotype (phorbol ester and 13-cis retinoic acid) on the growth of mouse neuroblastoma N2a cells in the mixed culture system. The results were compared with monoculture system and with tumor multicellular spheroids system where neoplastic cells are cultivated in the close contact from all sides. The suppression of the pleyotypic effect of phorbol ester was observed when N2a cells were cocultured with 3T3 fibroblasts. On the contrary, the close contact of neoplastic cells to each other (spheroids) do not change the stimulatory effect of phorbol ester on tumor cells proliferation. 13-cis retinoic acid suppressed neoplastic cells growth in all cell culture systems we used.     

Expression of retinoic acid receptor genes in developing rat livers and hepatoma cells.

The expression of retinoic acid receptor alpha, beta, and gamma mRNA was examined in developing rat livers and rat hepatoma-derived cell lines H-4-II-E, McA-RH 7777, and 8994 that represent different hepatocyte phenotypes. Northern blot hybridization demonstrated that all three receptor mRNAs were expressed in the fetal livers of different gestational ages, and the levels of expression increased significantly 3 to 4 weeks after birth. In the hepatoma cell lines, the expression pattern of retinoic acid receptor alpha and gamma mRNA did not correlate with the phenotype. In contrast, retinoic acid receptor beta mRNA was only detected in the adult phenotypic H-4-II-E cells but not in McA-RH 7777 and 8994 cells, which represent embryonic and fetal hepatocyte phenotypes, respectively. The levels of retinoic acid receptor beta mRNA in hepatoma cell lines were lower than adult rat liver. These data suggest that the increased expression of retinoic acid receptor beta gene is associated with differentiation or maturation of rat hepatocytes. The effect of retinoic acid on retinoic acid receptor gene expression was also studied in hepatoma cells. Retinoic acid did not regulate retinoic acid receptor gene expression in McA-RH 7777 and 8994 cells, and the retinoic acid receptor beta gene remained inactivated in these cells. However, Southern blot hybridization indicated that the gross structure of retinoic acid receptor beta gene was not altered during malignant transformation. In H-4-II-E cells, retinoic acid increased the expression of retinoic acid receptor beta and gamma gene. Because of the similarity between H-4-II-E cells and normal adult hepatocytes, this type of autoregulation may be a mechanism by which retinoic acid regulates its own effect in vivo.     

Cellular immune functions of adults treated with a daily, long-term, low dose of 13-cis retinoic acid

The effects of long-term consumption of 13-cis retinoic acid (13-cRA) on cellular immune functions were measured in young, adult volunteers. The retinoid was administered for 9 months at about 0.13 mg/kg/day. The mean 8AM concentrations of 13-cRA ranged between 30 and 60 ng/ml of serum throughout the study. Corticosteroid levels in plasma decreased significantly throughout treatment, declining from 15.2 ug/dL to 9.1 mg/dL (p less than 0.05). T-cell mitogenesis stimulated by PHA or A Con A was not significantly affected, although this parameter was slightly depressed during the first 2 months of treatment. The percentage of B-lymphocytes tended to decrease during treatment and returned to normal after cessation of 13-cRA (p less than 0.05), while the percentage of T-cells as measured by E-rosette and by fluorescent antibody tagging of surface antigens did not change. The percentage of non T-cells tended to increase slightly during treatment.     

Characterization of three synuclein genes in Xenopus laevis

The synuclein family consists of three small intracellular proteins mainly expressed in neural tissues, and has been associated with human neurodegenerative diseases. We have examined the spatial and temporal expression patterns of three synuclein genes during embryogenesis of Xenopus laevis. The Xenopus synucleins were firstly expressed in the developing nervous system at the tail bud stages. At tadpole stages, Xenopus snca was expressed in the brain, branchial arch and somite, and sncbb signals were detected in entire brain and spinal cord. However, sncg was only expressed in the peripheral nervous system including trigeminal nerve and dorsal root ganglion. RT‐PCR indicated that expression of synucleins was up‐regulated at the end of neurulation, and then maintained at later examined stages. Our study provides the spatiotemporal expression patterns of the synuclein family genes in Xenopus embryos, and forms a basis for further functional analysis of synucleins. Developmental Dynamics 240:2028–2033, 2011. © 2011 Wiley‐Liss, Inc.     

Treatment of 1-methyl-1-nitrosourea-induced mammary tumours with immunostimulatory CpG motifs and 13-cis retinoic acid in female rats: histopathological study.

Histopathological evaluation of the mammary gland tumours of Sprague-Dawley rats induced with 1-methyl-1-nitrosourea (MNU), and treated with either CpG oligodeoxynucleotides (CpG-ODN) and/or 13-cis retinoic acid has been performed in this work. Since, the treatment of animals with CpG-ODN induced a significant decrease of tumour burden and volume in comparison with MNU treated control group (Macejova et al. 2001), it was of high impact to compare histological appearance of tumours in different experimental groups (MNU, CpG-ODN, 13-cis retinoic acid, CpG-ODN plus 13-cis retinoic acid). We have found reduced number of carcinomas with necroses in the CpG motifs treated group when compared to animals treated with MNU only. From the histological point of view the treatment with the CpG-ODN may have some protective effect. Carcinoma patterns proportion in the group treated with CpG-ODN was found to be different in comparison with other experimental groups. Treatment of rats with CpG-ODN had no apparent effect on invasiveness of developed carcinomas.     

Expression and retinoic acid regulation of the zebrafish nr2f orphan nuclear receptor genes

Background : The vertebrate nuclear receptor subfamily 2, group f (nr2f) genes encode orphan receptors that have the capacity to act as negative regulators of retinoic acid (RA) signaling. Results : We describe embryonic and larval expression of four of the six zebrafish nr2f genes, nr2f1a, nr2f1b, nr2f2, and nr2f5. These genes show highly regulated patterns of expression within the central nervous system, including in the developing hindbrain, as well as in the mesoderm and endoderm. We also investigated the role of RA and fibroblast growth factor (Fgf) signaling in regulating early nr2f gene expression. RA is not required for nr2f expression in the hindbrain; however, exogenous RA can repress this expression. Conversely, we find that RA positively regulates nr2f1a expression in trunk endoderm and mesoderm. Fgf signaling is not required for nr2f expression onset in the hindbrain; however, it may play a role in maintaining rhombomere‐specific expression. Conclusions : We report detailed expression analysis of four nr2f genes in all three germ layers. The onset of nr2f expression in the hindbrain does not require RA or Fgf signals. Our finding that RA positively regulates nr2f1a expression in the trunk supports the possibility that Nr2fs function in a negative feedback loop to modulate RA signaling in this region. Developmental Dynamics 241:1603–1615, 2012. © 2012 Wiley Periodicals, Inc.     

Role of retinoic acid in lens regeneration.

Prompted by the actions of retinoids and their receptors in gene regulation, in the developing eye and especially in the lens, we have undertaken a detailed study to examine the effects of retinoids on urodele lens regeneration. First, we examined the effects of exogenous retinoids. It was found that exogenous retinoids had no significant effect on lens regeneration. However, when synthesis of retinoic acid was inhibited by disulfiram, or when the function of the retinoid receptors was impaired by using a RAR antagonist, the process of lens regeneration was dramatically affected. In the majority of the cases, lens regeneration was inhibited and lens morphogenesis was disrupted. In a few cases, we were also able to observe ectopic lens regeneration from places other than the normal site, which is from the dorsal iris. The most spectacular case was the regeneration of a lens from the cornea, an event possible only in premetamorphic frogs. These data show that inhibition of retinoid receptors is paramount for the normal course and distribution of lens regeneration. We have also examined expression of RAR-delta during lens regeneration. This receptor was expressed highly in the regenerating lens only. Therefore, it seems that this receptor is specific for the regeneration process and consequently such expression correlates well with the effects of RAR inhibition observed in our studies.