Effets des androgènes et des anti-androgènes sur l'apoptose des cellules germinales et prostatiques du rat

II est admis que le développement, la croissance et les fonctions testiculaires et prostatiques sont sous contrôle androgénique. Le rôle des androgènes dans l'apoptose et surtout les mécanismes moléculaires impliqués dans l'apoptose hormono-dépendante au niveau de ces deux organes sont encore mal élucidés. Nous avons étudié l'effet de la privation androgénique sur des molécules clés de l'apoptose (les caspases 3 et 6) au niveau du testicule et de la prostate. Cette privation hormonale a été réalisée par deux moyens : un traitement anti-androgénique (le flutamide) et la castration. En utilisant, comme modèle, des rats adultes exposés in utero à un anti-androgène (le flutamide aux doses de 0.4, 2 et 10 mg/kg/jour), nous avons montré que l'hypospermatogénèse et la régression prostatique ventrale observées chez les rats adultes pourraient être liées à un processus apoptotique chronique associé à une augmentation à long terme de l'expression et de l'activation des caspases effectrices 3 et 6. En effet, le nombre de cellules apoptotiques (TUNEL-positives), les taux d'ARNm (évalués par RT-PCR) et le taux protéique des pro-caspases 3 et 6 ainsi que de celui des caspases 3 et 6 activées augmentent en fonction de la dose de flutamide dans le testicule et la prostate ventrale (hormonosensible) mais pas dans les lobes prostatiques hormono-résistants. Dans le testicule, les pro-caspases 3 et 6 ont été détectées par immunohistochimie spécifiquement dans les cellules de Leydig et dans les cellules germinales de tous les tubules alors que la caspase 3 activée n'a été détectée que dans les cellules germinales post-méiotiques des tubules aux stades hormono-dépendants (stades VII et VIII). Nous avons également montré que ces effets observés sont irréversibles et chroniques si l'exposition au flutamide se passe in utero alors qu'ils sont transitoires si les rats sont exposés au flutamide à l'âge adulte. Les effets de l'anti-androgène sur l'apoptose de la prostate ventrale et sur l'expression des caspases 3 et 6 dans ce lobe hormonosensible et l'absence de ces effets au niveau des lobes dorso-latéraux et antérieurs (hormonorésistants) ont été confirmés sur un modèle de rats adultes castrés avec ou sans supplémentation en testostérone. Ce travail montre que dans les cellules (germinales) du testicule et (épithéiales) de la prostate ventrale, les anti-androgènes induisent une apoptose associée à une augmentation des caspases 3 et 6 au niveau transcriptionnel (et /ou de stabilisation des ARNm), traductionnel (et/ou de "turn over" des protéines) et d'activation des caspases. Ce travail supporte aussi le concept de la programmation fœtale de l'apoptose dans les tissus adultes comme le testicule et la prostate sous l'influence des hormones (androgènes).LYON1-BU.Sciences (692662101) / SudocSudocFranceF

Ultrasensitive Electrochemical Sensors for PSA Detection: Related Surface Functionalization Strategies

International audienc

Self assembled monolayers versus iron oxide nanoparticles modified surfaces: Two functionalization strategies for femtomolar detection of prostate specific antigen: Comparative study between two electrochemical biosensors for femtomolar detection of prostate specific antigen

International audienceTwo electrochemical immunosensors were investigated for prostate specific antigen detection. The first one was functionalized with 3-glycidypxypropyltrimethoxysilane self-assembled monolayer, while the second one was based on iron oxide nanoparticles functionalized with 3-aminopropyltriethoxysilane. Electrochemical impedance spectroscopy and square wave voltammetry have been investigated to follow-up the prostate specific antigen detection in a phosphate buffer solution and in a human serum. The limit of detection of both immunosensors was found of order of 10 fg/ml

Selected <it>AGXT </it>gene mutations analysis provides a genetic diagnosis in 28% of Tunisian patients with primary hyperoxaluria

Abstract Background Primary hyperoxaluria type I (PH1) is a rare genetic disorder characterized by allelic and clinical heterogeneity. Four mutations (G170R, 33_34insC, I244T and F152I) account for more than 50% of PH1 alleles and form the basis for diagnostic genetic screening for PH1. We aimed to analyze the prevalence of these specific mutations causing PH1, and to provide an accurate tool for diagnosis of presymptomatic patients as well as for prenatal diagnosis in the affected families. Methods Polymerase chain reaction/Restriction Fragment Length Polymorphism, were used to detect the four mutations in the AGXT gene in DNA samples from 57 patients belonging to 40 families. Results Two mutations causing PH1 were detected in 24 patients (42.1%), with a predominance of the I244T mutation (68% of patients) and 33_34insC (in the remaining 32%). In 92% of cases, mutated alleles were in homozygous state. The presented clinical features were similar for the two mutations. The age of onset was heterogeneous with a higher frequency of the pediatric age. In 58.3% of cases, the presentation corresponded to advanced renal disease which occurred early ( Conclusion Limited mutation analysis can provide a useful first line investigation for PH1. I244T and 33_34insC presented 28.2% of identified mutations causing disease in our cohort. This identification could provide an accurate tool for prenatal diagnosis in the affected families, for genetic counselling and for detection of presymptomatic individuals.</p

Metabolic Syndrome according to Three Definitions in Hammam-Sousse Sahloul Heart Study: A City Based Tunisian Study

Objectives. Metabolic syndrome (MetS) is a major risk factor of CVD. The aim of the present study is to determine the prevalence of the MetS, its components, and its different profiles according to NCEP-ATP III 2001, IDF 2005, and JIS 2009 definitions in Hammam-Sousse Sahloul Heart Study (HSHS). Study Design. The study involved 1121 participants (364 men and 757 women; sex-ratio  =  0.48; mean age  =  47.49 ± 16.24 years) living in Hammam Sousse city, located in the east of Tunisia. Methods. Anthropometric parameters, blood pressure, lipids levels, glycemia, insulinemia, and body mass index were measured. Statistical analyses were performed by SPSS16.0. Results. The percentage of participants who had MetS defined according to NCEP ATP III, IDF 2005, and JIS 2009 definitions was respectively, 29.5%, 38.4%, and 39.6%. With regard to gender, the prevalence of MetS is higher in men than in women according to IDF 2005 definition (38.5% men versus 38.3% women, P=0.961) and according to JIS 2009 definition (41.8% men versus 38.6% women, P=0.307), whereas, according to NCEP ATP III definition, the prevalence of MetS is higher in women than in men (30% versus 28.6%, P=0.627). The prevalence of MetS increased with increasing age according to the three definitions (P<0.001) and peaked in the oldest age group (≥70 years) according to IDF 2005 and JIS 2009. Furthermore, a significant difference in the prevalence of MetS components according to gender was observed. Indeed, the abdominal obesity is the most frequent MetS compound in women group, but hypertension and low HDL-C are the most frequent in men. In addition, according to the three definitions, the most frequent MetS profile in our study is “higher waist circumference, hypertension, and low HDL-C.” Conclusion. The high prevalence of MetS is a serious public health problem in Hammam-Sousse Sahloul community. Higher waist circumference, hypertension, and low HDL-C were the most frequent profile in our study

Unusual clinical outcome of primary Hyperoxaluria type 1 in Tunisian patients carrying 33_34InsC mutation

Abstract Background Primary hyperoxaluria type 1 (PH1), is a rare and heterogeneous disease and one of major causes of renal insufficiency in Tunisia, caused by mutations in the AGXT gene. 33-34InsC mutation, was mainly described in children with a severe clinical feature leading to early death, but it was uncommonly reported in adult patients. Methods Common mutations in AGXT were tested using PCR/RFLP technique in 111 patients (68 adult, 43 children) with suspected PH1. Results We described 16 cases (eight adult and eight children) with a 33-34InsC mutation with a median age of 24 years [6 months - 73 years]. All children were in end stage renal disease (ESRD) at the median age of 3 years due to lithiasis and/or nephrocalcinosis. Unfortunately, 75% of them died with a median age of 2.5 years. For the majority of adults only spontaneous elimination of urolithiasis were noted, 37.5% preserved until now a normal renal function and 62.5% of them reached ESRD at the median age of 55.8 ± 12.31 years old. Conclusion In this study 33-34InsC mutation gives a controversial clinical effect in children and adults. The implication of other genetic and/or environmental factors can play a crucial role in determining the ultimate phenotype

Computational approach and electrochemical measurements for protein detection with MIP-based sensor

International audienc

<i>DPYD</i> and <i>TYMS</i> polymorphisms as predictors of 5 fluorouracil toxicity in colorectal cancer patients

Colorectal cancer (CRC) is the third most common cancer and the fourth leading cause of cancer death. 5-Fluorouracil (5-FU) is an essential component of systemic chemotherapy for CRC. Our objective was to determine the genotypic frequency of polymorphisms affecting dihydropyrimidine dehydrogenase (DPYD) and thymidylate synthetase (TYMS) genes and to correlate the genetic profile with the toxicity due to 5-FU, also considering nongenetic factors. This is a prospective study that involved 66 patients. We extracted DNA by salting out methods. We carried out the genotyping of the different polymorphisms by simple PCR for the TYMS 5'UTR and by PCR-RFLP for DPYD: 1905 + 1 G > A, 85 T > C, 496 A > G, 1679 T > G, c.483 + 18G > A and the TYMS: 5'UTR VNTR, 5'UTR G > C and 3'UTR. The study of the association of DPYD and TYMS polymorphisms with the various signs of toxicity under 5-FU revealed that the polymorphisms 496 A > G were significantly associated with hepatotoxicity: OR = 3.85 (p = 0.04). In addition, 85 T > C was significantly associated with mucositis and neurotoxicity: OR = 4.35 (p = 0.03), OR = 3.79 (p = 0.02). For TYMS, the only significant association we observed for 5'UTR with vomiting: OR = 3.34 (p = 0.04). The incidence of adverse reactions related to 5-FU appears to be influenced in patients with CRC by the identified DPYD and TYMS gene polymorphisms in the Tunisian population.</p