Main Representative Publications
Overexpression of Interleukin-4 in the Thyroid of Transgenic Mice Upregulates the Expression of Duox1 and the Anion Transporter Pendrin.
Thyroid. 2016 Oct;26(10):1499-1512
Authors: Eskalli Z, Achouri Y, Hahn S, Many MC, Craps J, Refetoff S, Liao XH, Dumont JE, Van Sande J, Corvilain B, Miot F, De Deken X
BACKGROUND: The dual oxidases (Duox) are involved in hydrogen peroxide generation, which is essential for thyroid hormone synthesis, and therefore they are markers of thyroid function. During inflammation, cytokines upregulate DUOX gene expression in the airway and the intestine, suggesting a role for these proteins in innate immunity. It was previously demonstrated that interleukin-4 (IL-4) upregulates DUOX gene expression in thyrocytes. Although the role of IL-4 in autoimmune thyroid diseases has been studied extensively, the effects of IL-4 on thyroid physiology remain largely unknown. Therefore, a new animal model was generated to study the impact of IL-4 on thyroid function.
METHODS: Transgenic (Thyr-IL-4) mice with thyroid-targeted expression of murine IL-4 were generated. Transgene expression was verified at the mRNA and protein level in thyroid tissues and primary cultures. The phenotype of the Thyr-IL-4 animals was characterized by measuring serum thyroxine (T4) and thyrotropin levels and performing thyroid morphometric analysis, immunohistochemistry, whole transcriptome sequencing, quantitative reverse transcription polymerase chain reaction, and ex vivo thyroid function assays.
RESULTS: Thyrocytes from two Thyr-IL-4 mouse lines (#30 and #52) expressed IL-4, which was secreted into the extracellular space. Although 10-month-old transgenic animals had T4 and thyrotropin serum levels in the normal range, they had altered thyroid follicular structure with enlarged follicles composed of elongated thyrocytes containing numerous endocytic vesicles. These follicles were positive for T4 staining the colloid, indicating their capacity to produce thyroid hormones. RNA profiling of Thyr-IL-4 thyroid samples revealed modulation of multiple genes involved in inflammation, while no major leukocyte infiltration could be detected. Upregulated expression of Duox1, Duoxa1, and the pendrin anion exchanger gene (Slc26a4) was detected. In contrast, the iodide symporter gene Slc5a5 was markedly downregulated resulting in impaired iodide uptake and reduced thyroid hormone levels in transgenic thyroid tissue. Hydrogen peroxide production was increased in Thyr-IL-4 thyroid tissue compared with wild-type animals, but no significant oxidative stress could be detected.
CONCLUSIONS: This is the first study to show that ectopic expression of IL-4 in thyroid tissue upregulates Duox1/Duoxa1 and Slc26a4 expression in the thyroid. The present data demonstrate that IL-4 could affect thyroid morphology and function, mainly by downregulating Slc5a5 expression, while maintaining a normal euthyroid phenotype.
PMID: 27599561 [PubMed - in process]
NADPH oxidase DUOX1 promotes long-term persistence of oxidative stress after an exposure to irradiation.
Proc Natl Acad Sci U S A. 2015 Apr 21;112(16):5051-6
Authors: Ameziane-El-Hassani R, Talbot M, de Souza Dos Santos MC, Al Ghuzlan A, Hartl D, Bidart JM, De Deken X, Miot F, Diallo I, de Vathaire F, Schlumberger M, Dupuy C
Ionizing radiation (IR) causes not only acute tissue damage, but also late effects in several cell generations after the initial exposure. The thyroid gland is one of the most sensitive organs to the carcinogenic effects of IR, and we have recently highlighted that an oxidative stress is responsible for the chromosomal rearrangements found in radio-induced papillary thyroid carcinoma. Using both a human thyroid cell line and primary thyrocytes, we investigated the mechanism by which IR induces the generation of reactive oxygen species (ROS) several days after irradiation. We focused on NADPH oxidases, which are specialized ROS-generating enzymes known as NOX/DUOX. Our results show that IR induces delayed NADPH oxidase DUOX1-dependent H2O2 production in a dose-dependent manner, which is sustained for several days. We report that p38 MAPK, activated after IR, increased DUOX1 via IL-13 expression, leading to persistent DNA damage and growth arrest. Pretreatment of cells with catalase, a scavenger of H2O2, or DUOX1 down-regulation by siRNA abrogated IR-induced DNA damage. Analysis of human thyroid tissues showed that DUOX1 is elevated not only in human radio-induced thyroid tumors, but also in sporadic thyroid tumors. Taken together, our data reveal a key role of DUOX1-dependent H2O2 production in long-term persistent radio-induced DNA damage. Our data also show that DUOX1-dependent H2O2 production, which induces DNA double-strand breaks, can cause genomic instability and promote the generation of neoplastic cells through its mutagenic effect.
PMID: 25848056 [PubMed - indexed for MEDLINE]
Roles of DUOX-mediated hydrogen peroxide in metabolism, host defense, and signaling.
Antioxid Redox Signal. 2014 Jun 10;20(17):2776-93
Authors: De Deken X, Corvilain B, Dumont JE, Miot F
SIGNIFICANCE: Among the NADPH oxidases, the dual oxidases, DUOX1 and DUOX2, constitute a distinct subfamily initially called thyroid oxidases, based on their high level of expression in thyroid tissue. Genetic alterations causing inherited hypothyroidism clearly demonstrate their physiological implication in thyroid hormonogenesis. However, a growing list of biological functions triggered by DUOX-dependent reactive oxygen species (ROS) in highly differentiated mucosae have recently emerged.
RECENT ADVANCES: A role of DUOX enzymes as ROS providers for lactoperoxidase-mediated killing of invading pathogens has been well established and a role in bacteria chemorepulsion has been proposed. Control of DUOX expression and activity by inflammatory molecules and immune receptor activation consolidates their contributions to innate immune defense of mucosal surfaces. Recent studies conducted in ancestral organisms have identified effectors of DUOX redox signaling involved in wound healing including epithelium regeneration and leukocyte recruitment. Moreover, local generation of hydrogen peroxide (H2O2) by DUOX has also been suggested to constitute a positive feedback loop to promote receptor signaling activation.
CRITICAL ISSUES: A correct balance between H2O2 generation and detoxification mechanisms must be properly maintained to avoid oxidative damages. Overexpression of DUOX genes has been associated with an increasing number of chronic inflammatory diseases. Furthermore, H2O2-mediated DNA damage supports a mutagenic function promoting tumor development.
FUTURE DIRECTIONS: Despite the high sequence similarity shared between DUOX1 and DUOX2, the two isoforms present distinct regulations, tissue expression and catalytic functions. The phenotypic characterization of novel DUOX/DUOXA invalidated animal models will be very useful for defining their medical importance in pathological conditions.
PMID: 24161126 [PubMed - indexed for MEDLINE]
IFNβ/TNFα synergism induces a non-canonical STAT2/IRF9-dependent pathway triggering a novel DUOX2 NADPH oxidase-mediated airway antiviral response.
Cell Res. 2013 May;23(5):673-90
Authors: Fink K, Martin L, Mukawera E, Chartier S, De Deken X, Brochiero E, Miot F, Grandvaux N
Airway epithelial cells are key initial innate immune responders in the fight against respiratory viruses, primarily via the secretion of antiviral and proinflammatory cytokines that act in an autocrine/paracrine fashion to trigger the establishment of an antiviral state. It is currently thought that the early antiviral state in airway epithelial cells primarily relies on IFNβ secretion and the subsequent activation of the interferon-stimulated gene factor 3 (ISGF3) transcription factor complex, composed of STAT1, STAT2 and IRF9, which regulates the expression of a panoply of interferon-stimulated genes encoding proteins with antiviral activities. However, the specific pathways engaged by the synergistic action of different cytokines during viral infections, and the resulting physiological outcomes are still ill-defined. Here, we unveil a novel delayed antiviral response in the airways, which is initiated by the synergistic autocrine/paracrine action of IFNβ and TNFα, and signals through a non-canonical STAT2- and IRF9-dependent, but STAT1-independent cascade. This pathway ultimately leads to the late induction of the DUOX2 NADPH oxidase expression. Importantly, our study uncovers that the development of the antiviral state relies on DUOX2-dependent H2O2 production. Key antiviral pathways are often targeted by evasion strategies evolved by various pathogenic viruses. In this regard, the importance of the novel DUOX2-dependent antiviral pathway is further underlined by the observation that the human respiratory syncytial virus is able to subvert DUOX2 induction.
PMID: 23545780 [PubMed - indexed for MEDLINE]
Stroma cell-derived factor-1α signaling enhances calcium transients and beating frequency in rat neonatal cardiomyocytes.
PLoS One. 2013;8(2):e56007
Authors: Hadad I, Veithen A, Springael JY, Sotiropoulou PA, Mendes Da Costa A, Miot F, Naeije R, De Deken X, Entee KM
Stroma cell-derived factor-1α (SDF-1α) is a cardioprotective chemokine, acting through its G-protein coupled receptor CXCR4. In experimental acute myocardial infarction, administration of SDF-1α induces an early improvement of systolic function which is difficult to explain solely by an anti-apoptotic and angiogenic effect. We wondered whether SDF-1α signaling might have direct effects on calcium transients and beating frequency.Primary rat neonatal cardiomyocytes were culture-expanded and characterized by immunofluorescence staining. Calcium sparks were studied by fluorescence microscopy after calcium loading with the Fluo-4 acetoxymethyl ester sensor. The cardiomyocyte enriched cellular suspension expressed troponin I and CXCR4 but was vimentin negative. Addition of SDF-1α in the medium increased cytoplasmic calcium release. The calcium response was completely abolished by using a neutralizing anti-CXCR4 antibody and partially suppressed and delayed by preincubation with an inositol triphosphate receptor (IP3R) blocker, but not with a ryanodine receptor (RyR) antagonist. Calcium fluxes induced by caffeine, a RyR agonist, were decreased by an IP3R blocker. Treatment with forskolin or SDF-1α increased cardiomyocyte beating frequency and their effects were additive. In vivo, treatment with SDF-1α increased left ventricular dP/dtmax.These results suggest that in rat neonatal cardiomyocytes, the SDF-1α/CXCR4 signaling increases calcium transients in an IP3-gated fashion leading to a positive chronotropic and inotropic effect.
PMID: 23460790 [PubMed - indexed for MEDLINE]
Commentary: Thyrotropin Stimulates Differentiation Not Proliferation of Normal Human Thyrocytes in Culture.
Front Endocrinol (Lausanne). 2017;8:214
Authors: Kyrilli A, Paternot S, Miot F, Corvilain B, Vassart G, Roger PP, Dumont JE
PMID: 28890710 [PubMed]
Total thyroidectomy: a clue to understanding the metabolic changes induced by subclinical hyperthyroidism?
Clin Endocrinol (Oxf). 2017 Feb;86(2):270-277
Authors: Bel Lassen P, Kyrilli A, Lytrivi M, Ruiz Patino M, Corvilain B
OBJECTIVE: The effects of endogenous subclinical hyperthyroidism (eSCH) on heart and bone have been well documented. There are only limited data available regarding the impact of eSCH on weight regulation and lipid metabolism. Our aim was to evaluate the changes in body weight and metabolic parameters after total thyroidectomy in patients with pre-operative eSCH compared with pre-operative patients with euthyroid (EUT).
DESIGN: A retrospective study of 505 patients who underwent total thyroidectomy for benign multinodular goitre in an academic hospital in Brussels (Belgium) was performed.
PATIENT'S MEASUREMENTS: Two hundred and 25 patients were included (eSCH group: n = 74; EUT group: n = 151). The mean follow-up time was 26·1 ± 0·8 months and was similar in both groups.
RESULTS: Absolute BMI gain was significantly greater in the eSCH group than in the EUT group (1·11 ± 0·17 vs 0·33 ± 0·13 kg/m(2) ; P = 0·003). A significant increase in LDL cholesterol was observed in the eSCH group (16·1 ± 3·8 mg/dl; P < 0·001) but not in the EUT group (0·0 ± 3·0 mg/dl; P = 0·88). In a multivariate model, pre-operative TSH levels were the main factor significantly associated with increases in BMI or LDL cholesterol. Post-operative median TSH levels and L-thyroxine substitution were similar in both groups.
CONCLUSION: After total thyroidectomy, increases in weight and serum cholesterol were observed in the eSCH group. Given that post-operative TSH levels were similar in the two groups, these observations are probably due to the correction of eSCH, suggesting a direct effect of eSCH on body weight regulation and lipid metabolism.
PMID: 27651121 [PubMed - indexed for MEDLINE]