Publications by authors named "Geoffroy Marceau"

44 Publications

Hormonal Status and Cognitivo-Emotional Profile in Real-Life Patients With Neuropathic Pain: A Case Control Study.

Pain Pract 2019 09 27;19(7):703-714. Epub 2019 Jun 27.

Laboratoire Neuro-Dol Inserm 1107, University Clermont Auvergne, Clermont-Ferrand, France.

Background: The specific impact of neuropathic pain and recommended neuropathic pain treatments on the hormonal and immune status of patients has been so far poorly explored. This study aimed at studying, in real life, the hypothalamic-pituitary-adrenal axis and the cytokine profile of patients with neuropathic pain. It also explored their links with cognition, emotion, quality of life, and drug treatment.

Methods: This prospective study (clinicaltrials.gov NCT01543425) included 60 patients with neuropathic pain and 60 age- and gender-matched healthy volunteers after obtaining signatures of informed consent. A number of parameters were measured: adrenocorticotropic hormone, cortisol, cortisol awakening response, dehydroepiandrosterone sulphate, sex hormone binding globulin, testosterone, 17-β-estradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, cytokines, brain-derived neurotrophic factor, and vitamin D. Psychological parameters were assessed by questionnaires.

Results: Patients with neuropathic pain had lower levels of adrenocorticotropic hormone (P = 0.009) and dehydroepiandrosterone sulphate (P < 0.001) than controls, and the cortisol awakening response was impaired. Patients were more depressed and anxious (P < 0.001) and had a diminished quality of life (P < 0.001), which was influenced by cytokines (P = 0.0067) and testosterone (P = 0.028). Antidepressants and antiepileptics appeared to interfere with testosterone and cognitivo-emotional domains.

Conclusion: An impairment of the hormonal status and of the immune system was observed in patients. It identified testosterone as a potential pivotal mediator between antidepressants/antiepileptics and quality of life. Further studies must address the exact impact of different types of drugs on central effects, of gender differences, and of the immune system of neuropathic pain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/papr.12800DOI Listing
September 2019

Ethanolic extract of Algerian propolis decreases androgen receptor transcriptional activity in cultured LNCaP cells.

J Steroid Biochem Mol Biol 2019 05 1;189:108-115. Epub 2019 Mar 1.

Université Clermont Auvergne, GReD, CNRS UMR 6293, INSERM U1103, 28, place Henri Dunant, BP38, F63001, Clermont-Ferrand, France; Centre de Recherche en Nutrition Humaine d'Auvergne, 58 Boulevard Montalembert, F-63009, Clermont-Ferrand, France. Electronic address:

Antiandrogens have a peculiar place in the treatment of metastatic prostate cancer by blocking the androgen receptor (AR). Unfortunately, aggressive tumors could rapidly develop into a castration resistant state. It is therefore essential to look for new molecules that are more effective, affecting not only the androgen signaling and with minimum undesirable effects. Natural products are an interesting source of new therapeutics, especially for cancer therapy as 70% of them have botanical origin. Based on an ethnobotany screening, we evaluated the effects of ethanolic extract of propolis (EEP) from Algeria on LNCaP cells. Results pointed out that EEP reduces the survival of LNCaP cells with an IC of 0.04 mg/ml, induces the apoptosis and blocks the cell cycle at G0/G1 phase. Interestingly, EEP decreased the accumulation of AR suggesting some anti-androgen activity. Indeed, secreted amount of the androgen target protein PSA was decreased when LNCaP cells were incubated with EEP, starting after 4 h of treatment. This anti-androgen activity was also shown on the androgen target genes Fkbp5 and Sgk1. Finally, the capacity of EEP to block AR functioning was demonstrated in transient transfections with human AR and the reporter gene ARE-tk-Luc. Propolis antagonizes the induction of the luciferase activity induced by the natural androgen DHT (10M) or the synthetic AR agonist R1881 (10M). Altogether, these results highlight the potential pharmacological effects of EEP in future treatments of prostate cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jsbmb.2019.02.016DOI Listing
May 2019

Impact of Vitamin D Supplementation on Influenza Vaccine Response and Immune Functions in Deficient Elderly Persons: A Randomized Placebo-Controlled Trial.

Front Immunol 2019 8;10:65. Epub 2019 Feb 8.

University of Clermont Auvergne, INRA, UMR 1019 Human Nutrition Unit, Clermont-Ferrand, France.

Immunosenescence contributes to reduced vaccine response in elderly persons, and is worsened by deficiencies in nutrients such as Vitamin (Vit-D). The immune system is a well-known target of Vit-D, which can both potentiate the innate immune response and inhibit the adaptive system, and so modulate vaccination response. This randomized placebo-controlled double-blind trial investigated whether Vit-D supplementation in deficient elderly persons could improve influenza seroprotection and immune response. Deficient volunteers (Vit-D serum <30 ng/mL) were assigned (V1) to receive either 100,000 IU/15 days of cholecalciferol (D, = 19), or a placebo (P, = 19), over a 3 month period. Influenza vaccination was performed at the end of this period (V2), and the vaccine response was evaluated 28 days later (V3). At each visit, serum cathelicidin, immune response to vaccination, plasma cytokines, lymphocyte phenotyping, and phagocyte ROS production were assessed. Levels of serum 25-(OH)D increased after supplementation (D group, V1 vs. V2: 20.7 ± 5.7 vs. 44.3 ± 8.6 ng/mL, < 0.001). No difference was observed for serum cathelicidin levels, antibody titers, and ROS production in D vs. P groups at V3. Lower plasma levels of TNFα ( = 0.040) and IL-6 ( = 0.046), and higher ones for TFGβ ( = 0.0028) were observed at V3. The Th1/Th2 ratio was lower in the D group at V2 (D: 0.12 ± 0.05 vs. P: 0.18 ± 0.05, = 0.039). Vit-D supplementation promotes a higher TGFβ plasma level in response to influenza vaccination without improving antibody production. This supplementation seems to direct the lymphocyte polarization toward a tolerogenic immune response. A deeper characterization of metabolic and molecular pathways of these observations will aid in the understanding of Vit-D's effects on cell-mediated immunity in aging. This clinical trial was registered at clinicaltrials.gov as NCT01893385.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2019.00065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6375825PMC
December 2019

Retinoic acid and tracheal occlusion for diaphragmatic hernia treatment in rabbit fetuses.

Prenat Diagn 2018 06;38(7):482-492

"Translational approach to epithelial injury and repair" team, Université Clermont Auvergne, CNRS, Inserm, GReD, 63000, Clermont-Ferrand, France.

Introduction: Lung hypoplasia and pulmonary arterial hypertension in congenital diaphragmatic hernia lead to a high perinatal mortality. Although sustained fetoscopic tracheal occlusion (TO) improves lung development, a major side effect is abnormal pneumocyte differentiation. This study evaluated the potential ability of intratracheal retinoic acid (RA) administration to reduce adverse effects of sustained TO in a rabbit model of diaphragmatic hernia.

Methods: A left diaphragmatic defect was created on day 23 in time-dated pregnant rabbits. On day 28, the same rabbits underwent sham surgery or TO, with an injection of empty or RA-loaded liposomes. On day 30, the fetuses were harvested, and the lungs were processed for histology, immunohistochemistry, and gene expression quantification.

Results: A tracheal RA injection at the time of TO had no effect on the lung-to-body-weight ratio, radial alveolar count or lung connective tissue composition. Retinoic acid plus TO had synergic effects on vascular measurements, proportional medial thickness, and endothelin-1 receptor type-A gene expression. The most noticeable effect was recovery of normal pneumocyte differentiation.

Conclusion: Retinoic acid plus TO prevented abnormal pneumocyte differentiation and seemed to have a beneficial effect on pulmonary vascularization.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/pd.5256DOI Listing
June 2018

Myocilin expression is regulated by retinoic acid in the trabecular meshwork-derived cellular environment.

Exp Eye Res 2017 02 30;155:91-98. Epub 2017 Jan 30.

EA7281 - Retinoids, Reproduction Developmental Diseases, School of Medicine, Clermont Université, Université d'Auvergne, F-63000 Clermont-Ferrand, France. Electronic address:

Glaucoma is the leading cause of irreversible blindness and is usually classified as angle closure and open angle glaucoma (OAG). Primary open angle glaucoma represents the most frequent clinical presentation leading to ganglion cell death and optic nerve degeneration as a main consequence of an intraocular pressure' (IOP) increase. The mechanisms of this IOP increase in such pathology remain unclear but one protein called Myocilin could be a part of the puzzle in the trabecular meshwork (TM). Previously described to be transcriptionally regulated by glucocorticoids, the comprehension of the trabecular regulation of Myocilin' expression has only weakly progressed since 15 years. Due to the essential molecular and cellular implications of retinoids' pathway in eye development and physiology, we investigate the potential role of the retinoic acid in such regulation and expression. This study demonstrates that the global retinoids signaling machinery is present in immortalized TM cells and that Myocilin (MYOC) expression is upregulated by retinoic acid alone or combined with a glucocorticoid co-treatment. This regulation by retinoic acid acts through the MYOC promoter which contains a critical cluster of four retinoic acid responsive elements (RAREs), with the RARE-DR2 presenting the strongest effect and binding the RARα/RXRα heterodimer. All together, these results open up new perspectives for the molecular understanding glaucoma pathophysiology and provide further actionable clues on Myocilin gene regulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exer.2017.01.006DOI Listing
February 2017

Effects of tracheal occlusion with retinoic acid administration on normal lung development.

Prenat Diagn 2017 May 16;37(5):427-434. Epub 2017 Apr 16.

EA7281 - Retinoids, Reproduction Developmental Diseases, Auvergne University, Clermont-Ferrand, France.

Introduction: Tracheal occlusion (TO) is an investigational therapy for severe congenital diaphragmatic hernia that decreases pulmonary hypoplasia, but sustained TO also induces deficient surfactant synthesis. Intramuscular maternal administration of retinoic acid (RA) in a surgical rabbit model of congenital diaphragmatic hernia showed a beneficial effect on lung maturation. We evaluated the potential of RA delivery into the trachea and studied the combined effects of TO and RA on normal lung development.

Methods: Experiments were performed on normal rabbit fetuses. Liposomes and capric triglyceride (Miglyol ), alone and with RA, were administered in the trachea just before TO (d26). Lung morphology and surfactant production were studied at term (d30).

Results: Tracheal occlusion increased lung weight and enhanced alveolar development but increased apoptotic activity and decreased surfactant expression. Tracheal injection of RA improved surfactant production to levels of normal controls.

Conclusion: We established the potential of liposome and Miglyol as RA vehicle for delivering this bioactive molecule in the fetal airways. Tracheal RA injection seems to oppose the effects of TO in fetuses with normal lungs. © 2017 John Wiley & Sons, Ltd.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/pd.5012DOI Listing
May 2017

Different dose rate-dependent responses of human melanoma cells and fibroblasts to low dose fast neutrons.

Int J Radiat Biol 2016 09 3;92(9):527-35. Epub 2016 Jun 3.

a Centre Jean Perrin , Laboratoire de Radio-Oncologie Expérimentale , Clermont-Ferrand , France ;

Purpose: To analyze the dose rate influence in hyper-radiosensitivity (HRS) of human melanoma cells to very low doses of fast neutrons and to compare to the behaviour of normal human skin fibroblasts.

Materials And Methods: We explored different neutron dose rates as well as possible implication of DNA double-strand breaks (DSB), apoptosis, and energy-provider adenosine-triphosphate (ATP) levels during HRS.

Results: HRS in melanoma cells appears only at a very low dose rate (VLDR), while a high dose rate (HDR) induces an initial cell-radioresistance (ICRR). HRS does not seem to be due either to DSB or to apoptosis. Both phenomena (HRS and ICRR) appear to be related to ATP availability for triggering cell repair. Fibroblast survival after neutron irradiation is also dose rate-dependent but without HRS.

Conclusions: Melanoma cells or fibroblasts exert their own survival behaviour at very low doses of neutrons, suggesting that in some cases there is a differential between cancer and normal cells radiation responses. Only the survival of fibroblasts at HDR fits the linear no-threshold model. This new insight into human cell responses to very low doses of neutrons, concerns natural radiations, surroundings of accelerators, proton-therapy devices, flights at high altitude. Furthermore, ATP inhibitors could increase HRS during high-linear energy transfer (high-LET) irradiation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/09553002.2016.1186300DOI Listing
September 2016

Liver X Receptors (LXRs) Alpha and Beta Play Distinct Roles in the Mouse Epididymis.

Biol Reprod 2016 Mar 20;94(3):55. Epub 2016 Jan 20.

Equipe "Mécanismes post-testiculaires de l'infertilité," Clermont Université, Université Blaise Pascal, UMR GReD (Génétique Reproduction & Développement) CNRS 6293, INSERM U1103, Aubière, France.

After its production in the testis, a spermatozoon has to undergo posttesticular maturation steps to become fully motile and fertile. The first step is epididymal maturation, during which immature spermatozoa are transformed into biochemically mature cells ready to proceed to the next step, capacitation, a physiological process occurring in the female genital tract. The biochemical transformations include modification of sperm lipid composition during epididymal transit, with significant changes in fatty acids, phospholipids, and sterols between the caput and the cauda epididymal spermatozoa. Although quantitative aspects of these changes are well documented for several mammalian species, molecular mechanisms governing these steps are poorly understood. Transgenic male mice invalidated for the two liver X receptors (LXRalpha and LXRbeta, nuclear oxysterol receptors regulating cholesterol and lipid metabolism) become sterile when aging, showing an epididymal phenotype. We used single-knockout-model mice to characterize the role of each LXR isoform during sperm maturation in the epididymis. We show here that although a certain redundancy exists in the functions of the two LXR isoforms, some physiological processes are more under the influence of only one of them. In both cases, aging males showed slight subfertility, associated with dyslipidemia, emphasizing the importance of lipid metabolism in relation with male fertility.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1095/biolreprod.115.133538DOI Listing
March 2016

Multilevel Approach of a 1-Year Program of Dietary and Exercise Interventions on Bone Mineral Content and Density in Metabolic Syndrome--the RESOLVE Randomized Controlled Trial.

PLoS One 2015 16;10(9):e0136491. Epub 2015 Sep 16.

Clermont Auvergne University, Blaise Pascal University, Laboratory of Metabolic Adaptations to Exercise in Physiological and Pathological conditions (AME2P, EA3533), Clermont-Ferrand, France; Australian Catholic University, Faculty of Health, School of Exercise Science, Melbourne, Victoria, Australia; Research Centre in Human Nutrition (CRNH) Auvergne, Clermont-Ferrand, France; University Hospital of Clermont-Ferrand (CHU), Preventive and Occupational Medicine, Clermont-Ferrand, France.

Background: Weight loss is a public health concern in obesity-related diseases such as metabolic syndrome (MetS). However, restrictive diets might induce bone loss. The nature of exercise and whether exercise with weight loss programs can protect against potential bone mass deficits remains unclear. Moreover, compliance is essential in intervention programs. Thus, we aimed to investigate the effects that modality and exercise compliance have on bone mineral content (BMC) and density (BMD).

Methods: We investigated 90 individuals with MetS who were recruited for the 1-year RESOLVE trial. Community-dwelling seniors with MetS were randomly assigned into three different modalities of exercise (intensive resistance, intensive endurance, moderate mixed) combined with a restrictive diet. They were compared to 44 healthy controls who did not undergo the intervention.

Results: This intensive lifestyle intervention (15-20 hours of training/week + restrictive diet) resulted in weight loss, body composition changes and health improvements. Baseline BMC and BMD for total body, lumbar spine and femoral neck did not differ between MetS groups and between MetS and controls. Despite changes over time, BMC or BMD did not differ between the three modalities of exercise and when compared with the controls. However, independent of exercise modality, compliant participants increased their BMC and BMD compared with their less compliant peers. Decreases in total body lean mass and negative energy balance significantly and independently contributed to decreases in lumbar spine BMC.

Conclusion: After the one year intervention, differences relating to exercise modalities were not evident. However, compliance with an intensive exercise program resulted in a significantly higher bone mass during energy restriction than non-compliance. Exercise is therefore beneficial to bone in the context of a weight loss program.

Trial Registration: ClinicalTrials.gov NCT00917917.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0136491PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4574281PMC
May 2016

Aquaporins and Fetal Membranes From Diabetic Parturient Women: Expression Abnormalities and Regulation by Insulin.

J Clin Endocrinol Metab 2015 Oct 24;100(10):E1270-9. Epub 2015 Jul 24.

Retinoids, Reproduction Developmental Diseases (D.B., M.R., G.M., C.P., D.G., L.B., V.S.), School of Medicine, Clermont Université, Université d'Auvergne, F-63000 Clermont-Ferrand, France; Biochemistry and Molecular Biology Department (D.B., G.M., R.L. V.S.), CHU Clermont-Ferrand, F-63000 Clermont-Ferrand, France; Biostatistics Unit Department (B.P.), CHU Clermont-Ferrand, F-63000 Clermont-Ferrand, France; School of Medicine Henri-Warembourg (P.D., I.F.), Université Lille 2, PRES Lille Nord de France, F-59000 Lille, France; and Integrative Genomics and Modelization of Metabolic Diseases (A.V.), EGID, School of Medicine Henri-Warembourg, Université Lille 2, PRES Lille Nord de France, F-59000 Lille, France.

Context: During pregnancy, aquaporins (AQPs) expressed in fetal membranes are essential for controlling the homeostasis of the amniotic volume, but their regulation by insulin was never explored in diabetic women.

Objective: The aim of our study was to investigate the involvement of AQPs 1, 3, 8, and 9 expressed in fetal membranes in diabetic parturient women and the control of their expression by insulin.

Design And Participants: From 129 fetal membranes in four populations (controls, type 1, type 2 [T2D], and gestational diabetes [GD]), we established an expression AQP profile. In a second step, the amnion was used to study the control of the expression and functions of AQPs 3 and 9 by insulin.

Main Outcomes And Measures: The expression of transcripts and proteins of AQPs was studied by quantitative RT-PCR and ELISA. We analyzed the regulation by insulin of the expression of AQPs 3 and 9 in the amnion. A tritiated glycerol test enabled us to measure the impact of insulin on the functional characteristics. Using an inhibitor of phosphatidylinositol 3-kinase, we analyzed the insulin intracellular signaling pathway.

Results: The expression of AQP3 protein was significantly weaker in groups T2D and GD. In nondiabetic fetal membranes, we showed for the amnion (but not for the chorion) a significant repression by insulin of the transcriptional expression of AQPs 3 and 9, which was blocked by a phosphatidylinositol 3-kinase inhibitor.

Conclusion: In fetal membranes, the repression of AQP3 protein expression and functions observed in vivo is allowed by the hyperinsulinism described in pregnant women with T2D or GD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/jc.2015-2057DOI Listing
October 2015

Soluble Receptor for Advanced Glycation End-Products Predicts Impaired Alveolar Fluid Clearance in Acute Respiratory Distress Syndrome.

Am J Respir Crit Care Med 2015 Jul;192(2):191-9

1 Intensive Care Unit, Department of Anesthesiology, Critical Care and Perioperative Medicine, Estaing University Hospital.

Rationale: Levels of the soluble form of the receptor for advanced glycation end-products (sRAGE) are elevated during acute respiratory distress syndrome (ARDS) and correlate with severity and prognosis. Alveolar fluid clearance (AFC) is necessary for the resolution of lung edema but is impaired in most patients with ARDS. No reliable marker of this process has been investigated to date.

Objectives: To verify whether sRAGE could predict AFC during ARDS.

Methods: Anesthetized CD-1 mice underwent orotracheal instillation of hydrochloric acid. At specified time points, lung injury was assessed by analysis of blood gases, alveolar permeability, lung histology, AFC, and plasma/bronchoalveolar fluid measurements of proinflammatory cytokines and sRAGE. Plasma sRAGE and AFC rates were also prospectively assessed in 30 patients with ARDS.

Measurements And Main Results: The rate of AFC was inversely correlated with sRAGE levels in the plasma and the bronchoalveolar fluid of acid-injured mice (Spearman's ρ = -0.73 and -0.69, respectively; P < 10(-3)), and plasma sRAGE correlated with AFC in patients with ARDS (Spearman's ρ = -0.59; P < 10(-3)). Similarly, sRAGE levels were significantly associated with lung injury severity, and decreased over time in mice, whereas AFC was restored and lung injury resolved.

Conclusions: Our results indicate that sRAGE levels could be a reliable predictor of impaired AFC during ARDS, and should stimulate further studies on the pathophysiologic implications of RAGE axis in the mechanisms leading to edema resolution. Clinical trial registered with www.clinicaltrials.gov (NCT 00811629).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1164/rccm.201501-0020OCDOI Listing
July 2015

Evaluation of atorvastatin efficacy and toxicity on spermatozoa, accessory glands and gonadal hormones of healthy men: a pilot prospective clinical trial.

Reprod Biol Endocrinol 2014 Jul 12;12:65. Epub 2014 Jul 12.

CHU Clermont Ferrand, Laboratoire de BDR: AMP-CECOS, F-63003 Clermont-Ferrand, France.

Background: Recommendations for cardiovascular disease prevention advocate lowering both cholesterol and low-density lipoprotein cholesterol systemic levels, notably by statin intake. However, statins are the subject of questions concerning their impact on male fertility. This study aimed to evaluate, by a prospective pilot assay, the efficacy and the toxicity of a decrease of cholesterol blood levels, induced by atorvastatin on semen quality and sexual hormone levels of healthy, normocholesterolaemic and normozoospermic men.

Methods: Atorvastatin (10 mg daily) was administrated orally during 5 months to 17 men with normal plasma lipid and standard semen parameters. Spermatozoa parameters, accessory gland markers, semen lipid levels and blood levels of gonadal hormones were assayed before statin intake, during the treatment, and 3 months after its withdrawal.

Results: Atorvastatin treatment significantly decreased circulating low-density lipoprotein cholesterol (LDL-C) and total cholesterol concentrations by 42% and 24% (p<0.0001) respectively, and reached the efficacy objective of the protocol. During atorvastatin therapy and/or 3 months after its withdrawal numerous semen parameters were significantly modified, such as total number of spermatozoa (-31%, p<0.05), vitality (-9.5%, p<0.05), total motility (+7.5%, p<0.05), morphology (head, neck and midpiece abnormalities, p<0.05), and the kinetics of acrosome reaction (p<0.05). Seminal concentrations of acid phosphatases (p<0.01), α-glucosidase (p<0.05) and L-carnitine (p<0.05) were also decreased during the therapy, indicating an alteration of prostatic and epididymal functions. Moreover, we measured at least one altered semen parameter in 35% of the subjects during atorvastatin treatment, and in 65% of the subjects after withdrawal, which led us to consider that atorvastatin is unsafe in the context of our study.

Conclusions: Our results show for the first time that atorvastatin significantly affects the sperm parameters and the seminal fluid composition of healthy men.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1477-7827-12-65DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4114109PMC
July 2014

BRCA1 induces major energetic metabolism reprogramming in breast cancer cells.

PLoS One 2014 10;9(7):e102438. Epub 2014 Jul 10.

Jean Perrin Comprehensive Cancer Center and ERTICA EA4677 Research Team, University of Auvergne, Clermont-Ferrand, France; INRA, UMR 1019, UNH, Clermont-Ferrand, France.

The hypermetabolic nature of cancer cells and their increased reliance on "aerobic glycolysis", as originally described by Otto Warburg and colleagues, are considered metabolic hallmarks of cancer cells. BRCA1 is a major tumor suppressor in breast cancer and it was implicated in numerous pathways resulting in anticarcinogenic functions. The objective of our study was to address specific contributions of BRCA1 to the metabolic features of cancer cells, including the so-called "Warburg effect". To get a comprehensive approach of the role of BRCA1 in tumor cell metabolism, we performed a global transcriptional and metabolite profiling in a BRCA1-mutated breast cancer cell line transfected or not by wild-type BRCA1. This study revealed that BRCA1 induced numerous modifications of metabolism, including strong inhibition of glycolysis while TCA cycle and oxidative phosphorylation tended to be activated. Regulation of AKT by BRCA1 in both our cell model and BRCA1-mutated breast tumors was suggested to participate in the effect of BRCA1 on glycolysis. We could also show that BRCA1 induced a decrease of ketone bodies and free fatty acids, maybe consumed to supply Acetyl-CoA for TCA cycle. Finally increased activity of antioxidation pathways was observed in BRCA1-transfected cells, that could be a consequence of ROS production by activated oxidative phosphorylation. Our study suggests a new function for BRCA1 in cell metabolic regulation, globally resulting in reversion of the Warburg effect. This could represent a new mechanism by which BRCA1 may exert tumor suppressor function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0102438PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4092140PMC
November 2015

Energy expenditure, spontaneous physical activity and with weight gain in kidney transplant recipients.

Clin Nutr 2015 Jun 15;34(3):457-64. Epub 2014 May 15.

INRA, UMR 1019, UNH, CRNH Auvergne, F-63000 Clermont-Ferrand, France.

Background & Aims: Alterations in energy metabolism could trigger weight gain after renal transplantation.

Methods: Nineteen transplanted non-diabetic men, 53 ± 1.6 years old, receiving calcineurin inhibitors but no corticosteroids were studied. They were compared with nine healthy men matched for height, age and lean body mass. Daily energy expenditure and its components (sleeping, basal and absorptive metabolic rates) were analyzed for 24 h in calorimetric chambers and for 4 days in free living conditions using calibrated accelerometry. Other variables known to influence energy expenditure were assessed: body composition, physical activity, 4-day food intake, drug consumption, serum C-reactive protein, interleukin-6, thyroid and parathyroid hormones, and epinephrine. Transplant recipients who gained more than 5% body weight after transplantation (n = 11, +11.0 ± 1.5 kg) were compared with those who did not (n = 8) and with the controls.

Results: Weight gain compared with non-weight gain patients and controls exhibited higher fat mass without change in lean body mass. Daily, sleeping and resting energy expenditure adjusted for lean body mass was significantly higher in non-weight gain (167.1 ± 4.2 kJ/kg/lean body mass/24 h, P < 0.05) compared with weight gain patients (147.4 ± 3.6) and controls (146.1 ± 4.6). Weight gain compared with controls and non-weight gain subjects had lower free living physical activity and a higher consumption of antihypertensive drugs and β-blockers.

Conclusions: After kidney transplantation, weight gain patients were characterized by lower adjusted energy expenditure, reduced spontaneous physical activity but a more sedentary life style and a trend toward a higher energy intake explaining the reason they gained weight. The nWG KTR had increased resting and sleeping EE which protected them from weight gain. Such hypermetabolism was also observed in 24-h EE measurements. By comparison with the nWG patients, the WG transplant recipients were characterized by higher β-blocker consumption. These data could be helpful in the prevention of weight gain in kidney transplant recipients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clnu.2014.05.003DOI Listing
June 2015

Levels of liver X receptors in testicular biopsies of patients with azoospermia.

Fertil Steril 2014 Aug 17;102(2):361-371.e5. Epub 2014 May 17.

Génétique Reproduction et Développement, Clermont Université, Clermont-Ferrand, France; CNRS, UMR 6293, GReD, Aubière, France; INSERM, UMR 1103, GReD, Aubière, France; AMP-CECOS, CHU Clermont-Ferrand, CHU Estaing, Clermont-Ferrand, France. Electronic address:

Objective: To determine whether the transcription factors liver X receptors (LXRs) and their downstream genes, which are involved in the regulation of several testicular functions in mouse models, are differentially expressed in testes of men with nonobstructive azoospermia (NOA) or obstructive azoospermia (OA).

Design: Prospective study.

Setting: University hospital.

Patient(s): Patients with various types of NOA (n=22) and with OA (n=5).

Intervention(s): Human testicular biopsies.

Main Outcome Measure(s): Transcript levels were measured in testicular biopsies with the use of quantitative polymerase chain reaction. Correlations of LXR mRNA levels with the number of germ cells, the expression of proliferation and apoptosis markers, and the amount of intratesticular lipids and testosterone were evaluated. The localization of LXRα was analyzed by immunofluorescence.

Result(s): LXR mRNA levels were decreased by 49%-98% in NOA specimens and positively correlated with germ cell number. Accumulations of IDOL and SREBP1c (LXR targets involved in lipid homeostasis) were 1.8-2.1 times lower in NOA samples and mRNA levels of the SREBP1c target gene ELOVL6 were increased 1.9-2.4-fold. Interestingly, the amount of triglycerides and free fatty acids were higher in NOA testes (3.4-12.2-fold). LXRα was present in Leydig cells. Accumulations of LXR downstream genes encoding the steroidogenic proteins StAR and 3βHSD2 were higher in NOA testes (5.9-12.8-fold).

Conclusion(s): Knowledge of changes in the transcript levels of LXRs and some of their downstream genes during altered spermatogenesis may help us to better understand the physiopathology of testicular failure in azoospermic patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fertnstert.2014.04.033DOI Listing
August 2014

Bile acids alter male fertility through G-protein-coupled bile acid receptor 1 signaling pathways in mice.

Hepatology 2014 Sep;60(3):1054-65

INSERM U 1103, Génétique Reproduction et Développement (GReD), Aubière, France; Clermont Université, Université Blaise, Pascal, GReD, BP 80026, Aubière, France; CNRS, UMR 6293, GReD, Aubière, France; Centre de Recherche en Nutrition Humaine d'Auvergne, Clermont-Ferrand, France.

Unlabelled: Bile acids (BAs) are signaling molecules that are involved in many physiological functions, such as glucose and energy metabolism. These effects are mediated through activation of the nuclear and membrane receptors, farnesoid X receptor (FXR-α) and TGR5 (G-protein-coupled bile acid receptor 1; GPBAR1). Although both receptors are expressed within the testes, the potential effect of BAs on testis physiology and male fertility has not been explored thus far. Here, we demonstrate that mice fed a diet supplemented with cholic acid have reduced fertility subsequent to testicular defects. Initially, germ cell sloughing and rupture of the blood-testis barrier occur and are correlated with decreased protein accumulation of connexin-43 (Cx43) and N-cadherin, whereas at later stages, apoptosis of spermatids is observed. These abnormalities are associated with increased intratesticular BA levels in general and deoxycholic acid, a TGR5 agonist, in particular. We demonstrate here that Tgr5 is expressed within the germ cell lineage, where it represses Cx43 expression through regulation of the transcriptional repressor, T-box transcription factor 2 gene. Consistent with this finding, mice deficient for Tgr5 are protected against the deleterious testicular effects of BA exposure.

Conclusions: These data identify the testis as a new target of BAs and emphasize TGR5 as a critical element in testicular pathophysiology. This work may open new perspectives on the potential effect of BAs on testis physiology during liver dysfunction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/hep.27204DOI Listing
September 2014

Diagnostic accuracy of copeptin sensitivity and specificity in patients with suspected non-ST-elevation myocardial infarction with troponin I below the 99th centile at presentation.

BMJ Open 2014 Mar 24;4(3):e004449. Epub 2014 Mar 24.

Emergency Department, Henri Mondor Hospital, Aurillac, France.

Objective: To determine whether copeptin-us can rule out diagnosis of non-ST-segment elevation myocardial infarction (NSTEMI) without prolonged monitoring and serial blood sampling in patients with high-sensitive cardiac troponin I (hs-cTnI) below the 99th centile at presentation to the emergency department (ED) [corrected].

Design: Prospective, non-randomised, individual blinded diagnostic accuracy study.

Setting: Two EDs of a rural region of France.

Participants: Patients with chest pain suspected of NSTEMI with onset within the last 12 h were considered for enrollment.

Interventions: Serial clinical, electrographical and biochemical investigations were performed at admission and after 2, 4, 6 and 12 h. Hs-cTnI was measured using an assay with Dimension VISTA, Siemens [corrected]. Copeptin was measured by the BRAHMS copeptin-us assay on the KRYPTOR Compact Plus system. The follow-up period was 90 days.

Primary And Secondary Outcome Measures: Copeptin, troponin, myoglobin and creatine kinase values. Clinical and paraclinical events. The final diagnosis was adjudicated blinded to copeptin result.

Results: During 12 months, 102 patients were analysed. Final diagnosis was NSTEMI for 7.8% (n=8), unstable angina for 3.9% (n=4), cardiac but non-coronary artery disease for 8.8% (n=9), non-cardiac chest pain for 52% (n=53) and unknown for 27.5% (n=28). There was no statistical difference for copeptin values between patients with NSTEMI and others (respectively 5.5 pmol/L IQR (3.1-7.9) and 6.5 pmol/L IQR (3.9-12.1), p=0.49). Only one patient with NSTEMI had a copeptin value above the cut-off of 95th centile at admission.

Conclusions: In this study, copeptin does not add a diagnostic value at admission to ED for patients with suspected acute coronary syndrome without ST-segment elevation and with hs-cTnI below the 99th centile [corrected].

Trial Registration Number: Clinicaltrials.gov identifier: NCT01334645.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/bmjopen-2013-004449DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3975746PMC
March 2014

Emerging roles for LXRs and LRH-1 in female reproduction.

Mol Cell Endocrinol 2013 Apr 28;368(1-2):47-58. Epub 2012 Jun 28.

Laboratoire de Biochimie, Centre Hospitalier Universitaire de Nîmes, Hôpital Carémeau, Place du Pr. Robert Debré, F-30029 Nimes, France.

Nutritional status is known to control female reproductive physiology. Many reproductive pathologies such as anorexia nervosa, dystocia and preeclampsia, have been linked to body mass index and to metabolic syndrome. Lipid metabolism has also been associated with ovarian, uterine and placental functions. Among the regulators of lipid homeostasis, the Liver X Receptors (LXRs) and the Liver Receptor Homolog-1 (LRH-1), two members of the nuclear receptor superfamily, play a central role. LXRs are sensitive to intracellular cholesterol concentration and decrease plasma cholesterol, allowing to considering them as "cholesterol sensors". LRH-1 shares many target-genes with LXRs and has been considered for a long time as a real orphan nuclear receptor, but recent findings showed that phospholipids are ligands for this nuclear receptor. Acting in concert, LXRs and LRH-1 could thus be sensitive to slight modifications in cellular lipid balance, tightly maintaining their cellular concentrations. These last years, the use of transgenic mice clarified the roles of these nuclear receptors in many physiological functions. This review will be focused on the roles of LXRs and LRH-1 on female reproduction. Their contribution to ovarian endocrine and exocrine functions, as well as uterine and placental physiology will be discussed. The future challenge will thus be to target these nuclear receptors to prevent lipid-associated reproductive diseases in women.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mce.2012.06.009DOI Listing
April 2013

Dietary cholesterol-induced post-testicular infertility.

PLoS One 2011 2;6(11):e26966. Epub 2011 Nov 2.

Equipe Epididyme et Maturation des Gamètes, Clermont Université, Université Blaise Pascal, UMR GReD, Génétique Reproduction & Développement, CNRS 6247, INSERM U931, Aubière, France.

This work shows that an overload of dietary cholesterol causes complete infertility in dyslipidemic male mice (the Liver X Receptor-deficient mouse model). Infertility resulted from post-testicular defects affecting the fertilizing potential of spermatozoa. Spermatozoa of cholesterol-fed lxr-/- animals were found to be dramatically less viable and motile, and highly susceptible to undergo a premature acrosome reaction. We also provide evidence, that this lipid-induced infertility is associated with the accelerated appearance of a highly regionalized epididymal phenotype in segments 1 and 2 of the caput epididymidis that was otherwise only observed in aged LXR-deficient males. The epididymal epithelial phenotype is characterized by peritubular accumulation of cholesteryl ester lipid droplets in smooth muscle cells lining the epididymal duct, leading to their transdifferentiation into foam cells that eventually migrate through the duct wall, a situation that resembles the inflammatory atherosclerotic process. These findings establish the high level of susceptibility of epididymal sperm maturation to dietary cholesterol overload and could partly explain reproductive failures encountered by young dyslipidemic men as well as ageing males wishing to reproduce.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0026966PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3206870PMC
March 2012

Ontogeny of aquaporins in human fetal membranes.

Biol Reprod 2012 Feb 29;86(2):48. Epub 2012 Feb 29.

Laboratoire de Biochimie Médicale, Génétique Reproduction et Développement, Clermont-Université Institut National de la Santé et de la Recherche Médicale Unité, Faculté de Médecine, Université d'Auvergne, Clermont-Ferrand, France.

It has been proposed that four members of the aquaporin family (AQPs 1, 3, 8, and 9) are involved in the control of amniotic fluid (AF) homeostasis, as illustrated by their differential expression patterns in normal and pathological human term fetal membranes. However, there are no data available to date on their ontogeny throughout pregnancy. Our objective was to determine spatiotemporal expression profiles of the mRNA and proteins of all 13 members of this transmembrane channel family. For this purpose, we used healthy fetal membranes from the first, second, and third trimesters of pregnancy. Total mRNA and proteins were extracted from total membranes and from separated amnion and chorion. Quantitative PCR, Western blot, and immunohistochemistry experiments were carried out to determine the presence of AQPs and to quantify their spatiotemporal expression patterns throughout pregnancy. The WISH cell line was tested to propose a cellular model for the role of AQPs in the amnion compartment. AQP11 expression was established in amniotic membranes at term. Aquaporins 1, 3, 8, 9, and 11 mRNA and proteins were present in amnion and chorion throughout human gestation. Each AQP has a time-specific expression pattern, with AQP1 presenting the highest variation in terms of mRNA and protein levels. The WISH cell line also expressed the same five AQPs. Taken together, these results indicate that AQPs are expressed and potentially involved in the regulation of AF homeostasis throughout pregnancy. This also clearly supports the hypothesis that abnormal expression could occur at any time during pregnancy, ultimately leading to obstetrical pathologies such as polyhydramnios or oligohydramnios.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1095/biolreprod.111.095448DOI Listing
February 2012

Identification of GCN2 as new redox regulator for oxidative stress prevention in vivo.

Biochem Biophys Res Commun 2011 Nov 12;415(1):120-4. Epub 2011 Oct 12.

Unité de Nutrition Humaine, UMR 1019, INRA de Theix, 63122 Saint Genès Champanelle, France.

Constitution of oxidative defense systems and, correspondingly, oxidative stress prevention are highly dependent on amino acid supply. In vitro, experiments have demonstrated that amino acid availability participates to the homeostasis of reactive oxygen species. However the molecular mechanisms involved in the maintenance of redox homeostasis responsive to circulating amino acid levels remain unclear. As GCN2 is a protein kinase considered to be an important sensor for amino acids availability and a potential regulator of redox homeostasis, we hypothesized that this kinase can modulate redox homeostasis in vivo, in response to an amino acid-imbalanced diet. We investigated the response of GCN2+/+ and GCN2-/- mice to a long-term (24 weeks) leucine-imbalanced diet (EDΔLeu). In order to evaluate the oxidation level in each group of mice, we determined the degree of protein oxidation in the liver. Interestingly, GCN2-/- mice exhibited an increase in protein carbonylation, a marker of oxidative stress, in response to the EDΔLeu diet. These data correlate with a decrease in hepatic GPX1 expression, a major antioxidant enzyme, and a decrease in total GPX activity in the liver. Our results suggest that GCN2 and its downstream signaling pathway have an important role in the protection against oxidative injuries induced by an amino acid-imbalanced diet, and that it can play a critical role in the prevention of oxidative damage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbrc.2011.10.027DOI Listing
November 2011

Cushing's syndrome and fetal features resurgence in adrenal cortex-specific Prkar1a knockout mice.

PLoS Genet 2010 Jun 10;6(6):e1000980. Epub 2010 Jun 10.

CNRS UMR6247, Génétique Reproduction et Développement, Clermont Université, Aubière, France.

Carney complex (CNC) is an inherited neoplasia syndrome with endocrine overactivity. Its most frequent endocrine manifestation is primary pigmented nodular adrenocortical disease (PPNAD), a bilateral adrenocortical hyperplasia causing pituitary-independent Cushing's syndrome. Inactivating mutations in PRKAR1A, a gene encoding the type 1 alpha-regulatory subunit (R1alpha) of the cAMP-dependent protein kinase (PKA) have been found in 80% of CNC patients with Cushing's syndrome. To demonstrate the implication of R1alpha loss in the initiation and development of PPNAD, we generated mice lacking Prkar1a specifically in the adrenal cortex (AdKO). AdKO mice develop pituitary-independent Cushing's syndrome with increased PKA activity. This leads to autonomous steroidogenic genes expression and deregulated adreno-cortical cells differentiation, increased proliferation and resistance to apoptosis. Unexpectedly, R1alpha loss results in improper maintenance and centrifugal expansion of cortisol-producing fetal adrenocortical cells with concomitant regression of adult cortex. Our data provide the first in vivo evidence that loss of R1alpha is sufficient to induce autonomous adrenal hyper-activity and bilateral hyperplasia, both observed in human PPNAD. Furthermore, this model demonstrates that deregulated PKA activity favors the emergence of a new cell population potentially arising from the fetal adrenal, giving new insight into the mechanisms leading to PPNAD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pgen.1000980DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2883593PMC
June 2010

Increased expression of the oncogenic KLF6-SV1 transcript in human glioblastoma.

Clin Chem Lab Med 2010 Aug;48(8):1167-70

University Clermont 1, EA 3846, School of Medicine, Clermont-Ferrand, France.

Background: Gliomas constitute the vast majority of primary central nervous system tumors in adults. Glioblastoma multiforme (GBM) is the most aggressive form of these primary brain tumors. There is a need to define diagnostic and prognostic markers that may help to distinguish GBM from non-GBM tumors. The Krüppel-like factor 6 (KLF6) gene has recently emerged as a promising candidate. The goal of our study was to determine if there is a link between KLF6 splice variants expression and different grades of gliomas.

Methods: Fifty-three primary gliomas tumor samples were analyzed using quantitative real-time PCR for the total KLF6, wild-type and alternatively spliced (SV1) KLF6 mRNA.

Results: Compared to the non-GBM group, the GBM group had a 2.2-fold increase in the mean level of total KLF6 mRNA expression. GBM showed a 2.1-fold increase in the KLF6 splicing ratio. In addition, KLF6-SV1 mRNA expression levels were also 2.2-fold higher in the GBM group, suggesting that the increase in the KLF6 splicing ratio was due to increased expression of the KLF6-SV1 oncogenic splice variant.

Conclusions: Our study demonstrates that quantification of total and spliced forms of KLF6 may provide a new and useful supplementary molecular tool for grading glioma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1515/CCLM.2010.219DOI Listing
August 2010

Retinoid pathway and congenital diaphragmatic hernia: hypothesis from the analysis of chromosomal abnormalities.

Fetal Diagn Ther 2010 26;28(3):129-39. Epub 2010 May 26.

University Clermont, UFR Médecine, Histologie Embryologie Cytogénétique, CHU Clermont-Ferrand, France.

Background/objectives: Although there is strong evidence implicating genetic factors in congenital diaphragmatic hernia (CDH) pathogenesis, few causal genes have been identified. Many studies suggest that early disruption of the retinoid signaling pathway during gestation may contribute to CDH etiology. Chromosome abnormalities are detected in 10-20% of CDH cases. Chromosomal regions that are involved in balanced translocations or are recurrently deleted or duplicated in patients with CDH are of particular interest to researchers because they are more likely to harbor genes that cause or predispose one to the development of CDH. The aim of this review was to select chromosome loci which have been shown to be associated with CDH and to investigate if these loci contain candidate genes involved in the retinoic signaling pathway.

Data Sources: We have re-examined the known CDH-critical chromosomal loci and searched in available databases, such as the UCSC Genome Browser and OMIM, to see whether candidate genes related to the retinoid pathway were present within these loci.

Results: Twelve retinoid-related genes have been proposed as potential candidates. Among them, COUP-TFII, FOG2 and GATA4 have already been well studied, especially in animal models. We propose other candidates such as STRA6, LRAT, CRBP1, CRBP2 and CRABP1 are directly implicated in retinoic acid metabolism.

Conclusion: The identification of CDH-related genes and pathways affecting a normal diaphragm will contribute to the understanding of the pathophysiology of this severe embryopathy and might help to facilitate prenatal management and devise more individual treatment strategies. Further studies are necessary to screen large cohorts of patients with CDH for microimbalances or de novo mutations in these candidate genes. Moreover, functional analyses are needed to establish their exact role in CDH etiology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000313331DOI Listing
February 2011

Retinol potentiates the inhibitory effect of ascorbic acid on uric acid assay.

Clin Chem Lab Med 2010 May;48(5):693-5

Department of Biochemistry, Clermont-Ferrand Teaching Hospital, Clermont-Ferrand, France.

Background: The interference of ascorbic acid in the determination of plasma uric acid concentrations, by decreasing the formation of chromophore in Trinder's reaction, is well known. By contrast, the effects of other antioxidant vitamins, such as retinol and alpha-tocopherol have not been investigated. Knowledge of the analytical interaction of these antioxidants in the uric acid assay would be useful.

Methods: The effect of a mix of vitamins (Cernevit) on uric acid analysis in a patient hospitalized in a neurological intensive care unit was observed. The effects of the different antioxidant components of the mixture (retinol, alpha-tocopherol and ascorbic acid) on the concentration of uric acid from a pool of plasma were also tested.

Results: Among the different combinations of vitamins tested, only retinol potentiated the antioxidant effect of ascorbic acid. The most marked effect was observed with 80 IU/mL of retinol and 5.7 mmol/L of ascorbic acid.

Conclusions: We demonstrate for the first time the synergistic interference of ascorbic acid and retinol on the measurement of uric acid in plasma. We established that ascorbic acid interference is potentiated by regeneration of reduced ascorbic acid by retinol. Such interference must be kept in mind to avoid misinterpreting low plasma uric acid concentrations in patients in whom this analyte is critical.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1515/CCLM.2010.132DOI Listing
May 2010

Fetal skin fibroblasts: a cell model for studying the retinoid pathway in congenital diaphragmatic hernia.

Birth Defects Res A Clin Mol Teratol 2010 Mar;88(3):195-200

Clermont Université, UFR Médecine, Histologie Embryologie Cytogénétique, Clermont-Ferrand, France.

Background: Although there is strong evidence that genetic factors play a pathogenic role in congenital diaphragmatic hernia (CDH), few causal genes have been identified in humans. A number of studies, essentially in animal models, have suggested that disruption of the retinoid signaling pathway plays a major role in the pathogenesis of CDH. Our hypothesis is that human fetal skin fibroblasts express some metabolic and molecular actors of the retinoid pathway and that they offer convenient cellular material for investigating the molecular retinoid pathway defects associated with CDH.

Methods: We first established the expression of receptors, enzymes and binding proteins involved in the retinoic acid (RA) pathway in non-CDH fetal skin fibroblasts using RT-PCR and immunocytochemistry approaches. We then studied the expression of these genes in skin fibroblasts from seven fetuses with isolated and nonisolated CDH.

Results: Fetal skin fibroblasts expressed enzymes involved in RA metabolism as well as nuclear receptors for signal transduction. Basal levels of retinoic acid receptor, retinaldehyde dehydrogenase 2, and CYP26 (cytochrome P450 RAI) expression were altered in two of seven fetuses. Interestingly, these genes were previously described as abnormally expressed in CDH physiopathology.

Conclusion: Our results suggest that human fetal skin fibroblasts could be useful for studying retinoid signaling pathway disruption in the context of CDH. Our proposal is strengthened by the fact that we identified CDH fetuses for which molecular and metabolic actors of the retinoid pathway were not detected.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/bdra.20647DOI Listing
March 2010

Retinoids regulate human amniotic tissue-type plasminogen activator gene by a two-step mechanism.

J Cell Mol Med 2010 Jun 16;14(6B):1793-805. Epub 2009 Jun 16.

Génétique Reproduction et Développement (GReD), UMR CNRS 6247, Clermont Université, INSERM U931, Faculté de Médecine, Clermont-Ferrand, France.

The collagenolytic effects of the tissue-type plasminogen activator (t-PA) leading to extracellular matrix degradation are clearly involved in the physiopathology of human foetal membranes rupture. Nevertheless, the regulation of t-PA gene expression in extraembryonic developmental contexts remains unknown. The aim of our study is to propose the retinoic acids (RAs) as molecular regulators of t-PA expression in foetal membranes. RA induced t-PA mRNA and proteins in a time-dependent manner in amniotic membrane explants and Wistar Institute Susan Hayflick (WISH) cells. Furthermore, the use of cycloheximide revealed a two-step regulation of t-PA gene. Gene reporter assays confirmed that the RA-induced t-PA gene expression occurred through interactions of retinoid receptors (RARs and RXRs) with a DR5 response element located at -7 kb from the transcription site. Site-directed mutagenesis of this region of the t-PA promoter showed that SP1 factor was also retinoid-mediated induction, and immunoprecipitation assays revealed that SP1 and RAR/RXR interacted physically. Chromatin immunoprecipitation demonstrated that interactions between RARs, RXRs and t-PA promoter were time dependent: RAR-alpha/RXR-alpha bound DR5 motif before and up to 12 hrs of RA exposure, and RAR-beta/RXR-alpha bound DR5 response element after 12 hrs of RA treatment. Finally, experiments using shRNA and RAR-beta-specific antagonist revealed that reducing RAR-beta induction decreased t-PA induction. Altogether, our results established that the RA-mediated regulation of t-PA in human foetal membranes occurred through two steps, with a major role played by RAR-beta.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1582-4934.2009.00802.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3829039PMC
June 2010

Absence of nuclear receptors for oxysterols liver X receptor induces ovarian hyperstimulation syndrome in mice.

Endocrinology 2009 Jul 26;150(7):3369-75. Epub 2009 Mar 26.

Unité Mixte de Recherche, Centre National de la Recherche Scientifique 6247, Clermont Université, Centre de Recherche en Nutrition Humaine d'Auvergne, 63177 Aubière Cedex, France.

Ovarian hyperstimulation syndrome is a frequent complication occurring during in vitro fertilization cycles. It is characterized by a massive ovarian enlargement associated with an accumulation of extra vascular fluid. Here we show that liver X receptor (LXR)-alpha and LXR-beta deficient mice present many clinical and biological signs of ovarian hyperstimulation syndrome: ovarian enlargement, hemorrhagic corpora lutea, increased ovarian vascular permeability, and elevated estradiol. Ovulation stimulation resulted in excessive ovarian response to exogenous gonadotropins because follicle number and estradiol production were higher in transgenic mice. LXR deficiency also leads to perturbations in general inflammatory status, associated with ovarian il-6 deregulation. Upon treatment with the synthetic LXR agonist T09101317, serum estradiol and expression of star and cyp11a1 genes were markedly increased in wild-type mice, showing that LXRs are key regulators of ovarian steroidogenesis. These results suggest that LXRs control the ovulation by regulating endocrine and vascular processes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/en.2008-1519DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2703512PMC
July 2009