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Biomedical subjects

Françoise Paris

Publications and source records attributed to Françoise Paris.

18 recordsLinked to original sources
PubMed2006

Association between androgen receptor gene polymorphism and bone density in older women using hormone replacement therapy.

OBJECTIVE: The objective of this study was to investigate the relationship between bone mineral density (BMD) and both CAG repeat polymorphism of the androgen receptor (AR) gene and skewed X chromosome inactivation (SI) in postmenopausal women. METHODS: BMD was measured by DEXA. Both the number and the X-weighted biallelic mean of the CAG repeats of AR were analysed by PCR, before and after DNA digestion with methylation-sensitive HpaII in 192 healthy Caucasian postmenopausal women. RESULTS: The number of CAG repeats ranged from 10 to 34, with a median value of 22. CAG)(n< or =22) and CAG)(n> or =23) alleles were designated as short and long alleles, respectively. In women using hormone replacement therapy (HRT) (n=81), lumbar spine BMD was significantly lower, and femoral neck and total body BMD marginally lower in those with long-long alleles when compared with those with other genotypes. SI (> or =80%) was observed in 24% of the women and was not associated with BMD. In women using HRT, femoral neck BMD was significantly lower, and lumbar spine and total body BMD marginally lower in those whose X-weighted CAG repeat biallelic was greater than 22.59 (median value) when compared to other genotypes. These results were not found in women not using HRT. CONCLUSION: In conclusion, our results suggest that BMD may be associated with AR gene polymorphism in postmenopausal women using HRT but not with SI. Further studies are needed to investigate the mechanisms of the interaction between HRT, BMD and AR found in the present study.

Absorptiometry, Photon↗
PubMed2006

Clinical expression of polycystic ovary syndrome in adolescent girls.

Polycystic ovary syndrome (PCOS) is one of the major causes of adolescent hyperandrogenism and menstrual disorders. Because there is no universal definition for adolescent PCOS, we recommend four out of five criteria: clinical and biologic evidence of hyperandrogenism, hyperinsulinism, oligo-/amenorrhea, and polycystic ovaries on ultrasonography.

Adolescent↗
PubMed2005

Increased serum estrogenic bioactivity in three male newborns with ambiguous genitalia: a potential consequence of prenatal exposure to environmental endocrine disruptors.

In the past 15 years, anomalies of male sexual differentiation have greatly increased in both wildlife and humans in different parts of the world. Environmental endocrine disruptors have been implicated in the dramatic rise in neonatal ambiguous genitalia with variable rates of severity, such as micropenis, cryptorchidism, and isolated or associated hypospadias. Because most environmental pollutants, such as organochlorine pesticides, polychlorinated biphenyls, dioxins and furans, alkylphenol polyetholyethoxylates, and phytoestrogens and phtalates, have estrogenic and antiandrogenic activity, they are able to interfere with normal fetal male sexual differentiation. In a neonatal screening program of ambiguous genitalia, we had the opportunity to evaluate three newborns with male pseudohermaphroditism (MPH) whose mothers were exposed to endocrine disruptors during pregnancy. All had normal testosterone production after human chorionic gonadotrophin stimulation testing, suggesting androgen resistance or so-called idiopathic MPH. Sequences of the 5alpha reductase and androgen receptor genes were normal. Since environmental pollutants are known for their estrogenic activity and can be released progressively from the adipose tissue where they accumulate, we detected their presence by measuring the estrogenic bioactivity of the newborns' serum with a recently developed ultrasensitive bioassay. We found higher estrogenic bioactivity in these newborns than in controls. In conclusion, the maternal exposure to environmental pollutants during pregnancy and high estrogenic bioactivity in the newborns' serum highly suggest that ambiguous genitalia are related to fetal exposure to endocrine disruptors.

Agriculture↗
PubMed2005

Association between androgen receptor gene CAG repeat polymorphism and plasma testosterone levels in postmenopausal women.

OBJECTIVES: The biologic action of androgens in target cells depends on plasma androgen levels and receptor transcriptional activity. We investigated the relationship between androgen receptor (AR) CAG repeat polymorphism, serum androgen levels, and anthropometric, metabolic, and hormonal variables in 39 postmenopausal women, taking into consideration the patterns of X-chromosome inactivation. METHODS: Genomic DNA was extracted from peripheral leukocytes. Polymerase chain reactions (PCRs) were performed to amplify the polymorphic (CAG)n repeat of the human AR gene, which were analyzed with GeneScan software (Applied Biosystems, Foster City, CA). The X-chromosome inactivation analysis was based on the AR gene methylation patterns. RESULTS: The mean age of participants was 54.7 years; mean age at menopause was 48 years. The number of CAG repeats ranged from 15 to 30, with a median length of 23. Analysis of X-chromosome inactivation patterns showed 19 cases with a degree of skewing (DS) > or =70% and seven with a DS > or =90%. The X-weighted CAG repeat biallelic mean was significantly lower in individuals with total testosterone (TT) greater than 0.56 ng/mL (group mean) than in the group with TT < or =0.56 (P=.018). No difference was observed between the groups regarding dehydroepiandrosterone sulfate (DHEA-S). Plasma TT was significantly higher in the group with the smaller X-weighted CAG repeat biallelic mean (P=.01). Free androgen index (FAI) was also significantly higher in this group (P=.033). Testosterone levels and FAI were inversely correlated to X-weighted CAG repeat biallelic mean. CONCLUSION: Our data indicate an association between testosterone plasma levels and AR CAG repeats in postmenopausal women, and suggest that plasma levels of androgens in postmenopausal women may be related to variants of the AR gene.

Alleles↗
PubMed2004

Activating Gsalpha mutations: analysis of 113 patients with signs of McCune-Albright syndrome--a European Collaborative Study.

McCune-Albright syndrome (MAS) is a sporadic disorder characterized by the classic triad of polyostotic fibrous dysplasia, café-au-lait skin pigmentation, and peripheral precocious puberty. It is due to postzygotic activating mutations of arginine 201 in the guanine-nucleotide-binding protein (G protein) alpha-subunit (Gsalpha), leading to a mosaic distribution of cells bearing constitutively active adenylate cyclase. MAS is heterogeneous: beyond the classic triad, a number of atypical or partial presentations have been reported. We present here the results of a systematic search for Gsalpha mutations in patients presenting with at least one of the signs of MAS, using a PCR-based sensitive method. We studied 113 patients (98 girls and 15 boys), 24% presenting the classic triad, 33% with two signs, and 40% with only one classic sign. Overall, the mutation was identified in 43% of the patients. When an affected tissue was available, the mutation was found in more than 90% of the patients, whatever the number of signs. Skin was a noteworthy exception because only three of the 11 skin samples were positive. The mutation was detected in 46% of blood samples in patients presenting the classic triad, whereas this figure fell to 21% and 8% in patients with two and one sign, respectively. Our results highlight the frequency of partial forms of MAS and the usefulness of sensitive techniques to confirm the diagnosis at the molecular level. It should be emphasized that we found the mutation in 33% of the 39 cases of isolated peripheral precocious puberty. This study has further widened the definition of MAS. Affections as clinically different as monostotic fibrous dysplasia, isolated peripheral precocious puberty, neonatal liver cholestasis, and the classic MAS all appear to be components of a wide spectrum of diseases based on the same molecular defect.

Bone and Bones↗
PubMed2004

An N-terminal WT1 mutation (P181S) in an XY patient with ambiguous genitalia, normal testosterone production, absence of kidney disease and associated heart defect: enlarging the phenotypic spectrum of WT1 defects.

OBJECTIVE: This study reports the clinical and molecular data of an XY patient with a very unusual phenotype due to a Wilms' tumor-suppressor (WT1) gene mutation. The genotype-phenotype relationship of different WT1 mutations is then discussed. PATIENT: The patient presented at birth with micropenis, severe hypospadias and cryptorchidism. Normal androgen production and an absence of clinical response to a testosterone treatment trial suggested partial androgen resistance. Eventually, female sex of rearing was chosen. At the beginning of puberty, normal male androgen production occurred, and subsequent gonadectomy did not show gonadal dysgenesis. It is notable that the patient, now 20 years of age, has not developed kidney disease. In addition to the genital malformation, the patient displayed an associated congenital heart defect, consisting of a coarctation of the aorta and a patent ductus arteriosis (PDA). RESULTS: No mutations were detected in the androgen receptor or 5alpha-reductase genes. Direct sequencing of the WT1 gene identified a heterozygous proline to serine substitution at position 181 (P181S). The same heterozygous mutation was found in the mother. Interestingly, the mother shows no signs of kidney disease at her present age of 49. CONCLUSION: This is the first germline missense mutation in the N-terminal part of WT1 identified in a patient with the very particular phenotype of ambiguous genitalia with absence of gonadal dysgenesis and kidney disease. The possible molecular mechanisms leading to the patient's phenotype are considered. The high frequency of PDA in newborns and the absence of heart abnormalities in XX females carrying the P181S mutation, however, suggest that the heart defect was most likely a coincidental association. This case enlarges the clinical spectrum of WT1 defects and may provide new insights into the complex functions of WT1 in genital and kidney development.

Aortic Coarctation↗
PubMed2002

Evaluation of androgenic bioactivity in human serum by recombinant cell line: preliminary results.

Besides the measurement of circulating conjugated metabolites of dihydrotestosterone (DHT), which reflects androgenic activity, only one assay to measure androgenic bioactivity in human serum has been proposed thus far. This recombinant bioassay is based on the androgen-dependent interaction between the LBD and NT domains of AR fused to the Gal 4 DNA-binding domain, but its construction is highly complex. We have developed a mammalian cell (CHO 515) bioassay that measures total androgen bioactivity in human serum. The AR-deficient Chinese hamster ovary (CHO) cells were stably transfected with pSG5-puro-hAR and pMMTV-neo-Luc. After selection with puromycin and neomycin, five highly inducible clones were isolated and one was selected. The expression of human androgen receptor (hAR) was confirmed by Western blot and steroid-binding assays on the whole cells. The transcriptional activity of the clone was measured after 24 h of incubation with increasing concentrations of various androgenic and non-androgenic steroid compounds in a 96-well plate. The EC50s for each tested androgenic steroid compound were 4 x 10(-11) M, 1.5 x 10(-11) M, 1 x 10(-9) M, 2 x 10(-10) M, 3 x 10(-10) M for testosterone, DHT, dehydroepiandrosterone (DHEA), delta5-androstenediol, and delta4-androstenedione, respectively. In the physiological concentrations of the non-androgenic steroids, estradiol, cortisol, aldosterone, and progesterone, no interference was noted with the AR transactivation level. Evaluation of androgenic bioactivity in human serum was performed by incubation of CHO 515 cells with 100 microl of patient serum, diluted at 1/100 = 1% in DMEM-F12 without phenol red. The sensitivity of the assay was < 0.3 ng/ml. The mean androgenic bioactivity expressed in testosterone equivalents was 0.6 +/- 0.2 ng/ml in normal prepubertal boys, and 12.4 +/- 2 and 1.7 +/- 0.1 ng/ml in normal pubertal boys and girls, respectively. In conclusion, this new recombinant cell bioassay is today the only assay that takes into account testosterone, DHT, DHEA, delta5-androstenediol, and delta4-androstenedione. It should be of particular use in male children with cryptorchidism, delayed puberty or hypogonadotrophic hypogonadism, i.e., in pediatric patients with low androgen levels.

Androgens↗
PubMed2002

Evidence that chlormadinone acetate exhibits antiandrogenic activity in androgen-dependent cell line.

Chlormadinone acetate (CMA), like other 17-hydroxyprogesterone derivatives, is thought to be a potential antiandrogen on the basis of its effect on spontaneous benign prostatic hyperplasia (BPH) in dogs. This work was undertaken to find out whether CMA presents antiandrogen activity in human androgen-dependent cell line. For this purpose, we used PALM cells, the PC-3 cell line stably transfected with human androgen receptor and a luciferase gene under transcriptional control of MMTV. Potential antiandrogenic activity was compared with that of cyproterone acetate (CPA), a standard steroidal antiandrogen. Both compounds were tested in competitive binding assays at 37 degrees C in the presence of 1 nM of [3H] R1881, a synthetic and non-metabolizable androgen. Their impact on AR transcriptional activity was evaluated by the measure of luciferase activity in the presence of R1881 with increasing concentrations of CMA or CPA (10(-8)-10(-6) M). In whole cell binding assays, competitive studies revealed that the Ki for CMA was 3.3 +/- 1.5 x 10(-8) M (versus 7.2 +/- 1.3 x 10(-8) M for CPA). Inhibition of AR transcriptional activity was 40 +/- 5% for CMA (3 x 10(-7) M) versus 59 +/- 6% for CPA at the same concentration. Moreover, CMA caused a slower import of green fluorescent protein (GFP)-AR to the nuclei of COS-7 cells than R1881. These data show that CMA exerted a competitive binding for AR and significantly decreased the AR transcriptional activity. In conclusion, this synthetic progestin presents simultaneous antiandrogenic activity that could be helpful as a new therapeutic option in women with luteal defect along with clinical signs of hyperandrogenism.

Active Transport, Cell Nucleus↗
PubMed2002

Phenylphenols, biphenols, bisphenol-A and 4-tert-octylphenol exhibit alpha and beta estrogen activities and antiandrogen activity in reporter cell lines.

We previously demonstrated the interactions of different chemical compounds with estrogen receptors ERalpha and ERbeta and the androgen receptor (AR) using different reporter cell lines. In this study, we characterize the ERalpha, ERbeta and AR activity of different biphenyls using the same tools. We provide evidence that several phenyl derivatives present both estrogenic and antiandrogenic activity. The extent of hydroxylation and the position of the hydroxyl function were important in determining their estrogenicity and antiandrogenicity. Of the tested compounds, bisphenol-A and 4,4' biphenol had very high estrogenic activity, although it was lower than that of the strong estrogenic alkylphenol, 4-tert-octylphenol. Bisphenol-A and 4,4' biphenol were able to activate ERs at concentrations lower than 1 microM, whereas the other compounds only activated at concentrations above 1 microM. Interestingly, 4,4' biphenol was a better agonist for ERbeta than for ERalpha. No androgenic activity was detected for any of these compounds. Bisphenol-A, 3-OH phenylphenol, 4-OH phenylphenol and 4,4' biphenol exhibited antiandrogenic activity close to that of 4-tert-octylphenol (IC(50) approximately 5 microM). In whole cell binding assays, these compounds displaced [3H] R1881 with Ki = 10 microM. Although these Ki values seem high in comparison with that of hydroxyflutamide (0.4 microM), one must keep in mind that environmental chemicals can accumulate in adipose tissues for several years. In conclusion, these environmental chemicals may have a negative impact on androgen action during fetal and post-natal life.

Androgen Receptor Antagonists↗
PubMed2002

Equilibrium binding assays reveal the elevated stoichiometry and salt dependence of the interaction between full-length human sex-determining region on the Y chromosome (SRY) and DNA.

In an effort to better define the molecular mechanism of the functional specificity of human sex-determining region on the Y chromosome (SRY), we have carried out equilibrium binding assays to study the interaction of the full-length bacterial-expressed protein with a DNA response element derived from the CD3epsilon gene enhancer. These assays are based on the observation of the fluorescence anisotropy of a fluorescein moiety covalently bound to the target oligonucleotide. The low anisotropy value due to the fast tumbling of the free oligonucleotide in solution increases substantially upon binding the protein to the labeled target DNA. Our results indicate that the full-length human wild-type SRY (SRY(WT)) forms a complex of high stoichiometry with its target DNA. Moreover, we have demonstrated a strong salt dependence of both the affinity and specificity of the interaction. We have also addressed the DNA bending properties of full-length human SRY(WT) in solution by fluorescence resonance energy transfer and revealed that maximal bending is achieved with a protein to DNA ratio significantly higher than the classical 1:1. Oligomerization thus appears, at least in vitro, to be tightly coupled to SRY-DNA interactions. Alteration of protein-protein interactions observed for the mutant protein SRY(Y129N), identified in a patient presenting with 46,XY sex reversal, suggests that oligomerization may play an important role in vivo as well.

DNA↗
PubMed2002

Ambiguous genitalia in the newborn.

Ambiguous genitalia in the newborn need immediate and rational management. This complex situation requires a strategy of clinical, hormonal, genetic, molecular, and radiographic investigation to determine the etiology of the intersex state and orient the therapeutic approach. Physical examination is key to diagnosis. Careful palpation to locate gonads at the genital folds or in the inguinal region provides the first element for diagnostic orientation. If gonads are absent, a diagnosis of female pseudohermaphroditism seems advisable; if gonads are palpated, a diagnosis of male pseudohermaphroditism is more appropriate. Karyotyping is systematic while polymerase chain reaction (PCR) analysis of the SRY gene provides information about the presence of a Y chromosome within 1 day. Hormonal investigation should be based on clinical and genetic orientation. Substantially elevated plasma 17-OH progesterone will confirm the diagnosis of congenital adrenal hyperplasia due to deficiency in 21-hydroxylase. Testicular stimulation with human chorionic gonadotropin (hCG) will determine the functional value of testicular tissue. Exploration of the genitourinary axis is principally carried out by ultrasound and genitography. By the end of these investigations, the medical team should be able to give a precise diagnosis. Female pseudohermaphroditism may be due to excess fetal androgens (congenital adrenal hyperplasia), increased androgen production of maternal origin, or placental androgen excess. In male pseudohermaphroditism, if testosterone rises normally after hCG stimulation, androgen resistance is indicated. If it does not rise after this test, either testicular dysgenesis or disturbance in testosterone biosynthesis may be responsible. The assignment of sex for rearing must be guided by the etiology of the genital malformation, the anatomic condition, and family considerations. In cases of female pseudohermaphroditism, the newborn should always be declared to be of female sex at birth. In cases of male pseudohermaphroditism, great care should be taken in the declaration of male sex: the potential for reconstructive surgery and the pubertal "programmed" response of the external genitalia to endogenous and exogenous testosterone are determinant. Management of ambiguous genitalia in the newborn requires an entire multidisciplinary team in every step of the diagnostic procedure, the choice of sex assignment, and the treatment strategy.

Disorders of Sex Development↗
PubMed2002

Disorders of androgen action.

Disorders of androgen action are the main cause of male pseudohermaphroditism and include 5alphaR deficiency and androgen receptor defects. 5alphaR deficiency is characterized by female genitalia with some degree of masculinization, clitoromegaly, and severely bifid scrotum corresponding to the so-called pseudovaginal perineoscrotal hypospadias. At the onset of puberty, increased muscle mass, development of pubic hair, and phallic growth are associated with the acquisition of male gender identity. Normal or increased levels of testosterone and an elevated testosterone-to-dihydrotestosterone ratio after human chorionic gonadotropin stimulation testing suggest 5alphareductase deficiency, and the diagnosis can be ascertained by identifying the mutation in the 5alphaR-2 gene. Whatever the patient's age at diagnosis, psychological evaluation with 5alphaRD is vital. Androgen receptor defects encompass two clinical expressions: the complete and partial androgen insensitivity syndromes. Complete androgen insensitivity syndrome should be suspected at birth in the presence of inguinal hernia in a girl without genital ambiguity. At puberty, the sign of alert is primary amenorrhea with normal female phenotype and harmonious mammary development but no pubic hair growth. Partial androgen insensitivity syndrome covers a wide spectrum of undervirilized phenotypes ranging from clitoromegaly at birth to infertile men. In all cases, complementary investigations should include plasma testosterone and luteinizing hormone as well as androgen-binding capacity in cultured genital skin fibroblasts. Diagnosis is confirmed by identification of the androgen receptor gene mutation. Although patients with complete androgen insensitivity syndrome are raised as females, patients with partial androgen insensitivity syndrome should be managed according to age at diagnosis, response to treatment with exogenous androgens, and the presence of an androgen gene mutation. Gonadectomy in complete androgen insensitivity syndrome should be performed before puberty, and androgen substitution may improve the development of external genitalia in some patients with partial androgen insensitivity syndrome. Psychological follow-up is necessary.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2002

A new recombinant cell bioassay for ultrasensitive determination of serum estrogenic bioactivity in children.

The evaluation of estrogenic status is necessary for many physiological and pathological conditions in pediatric as well as adult endocrinology. Because current immunoassays exclusively measure E2--and with a sensitivity that is insufficient for prepubertal children--we developed a new recombinant cell bioassay for ultrasensitive determination of serum estrogenic bioactivity. This assay is based on human uterine cervix carcinoma cells, HeLa cells, that do not naturally express E2 receptor. These cells were transfected with plasmids encoding the human ERalpha or beta, along with an estrogen-responsive promoter fused to the luciferase gene, and called HELNalpha and HELNbeta for HeLa estrogen-responsive element luciferase neomycin alpha and beta. HELNalpha and HELNbeta are able to respond to estrogens and various compounds having estrogenic activity but, because of the importance of ERalpha in the reproductive function, we chose to work with the HELNalpha cell line. The luciferase activity we obtained was compared with an E2 standard curve specific for each serum sample and established with stripped serum. The estrogenic bioactivity was expressed in picograms of E2 equivalents, and the detection limit was < 1 pg x ml(-1) E2 equivalents. The intra and interassay error was lower than 10% and 20%, respectively. We measured estrogenic bioactivity in 18 normal prepubertal boys (age = 9.7 +/- 2.4 yr), 18 normal prepubertal girls (age = 9.2 +/- 1.7 yr) and 18 normal pubertal girls (age = 13.6 +/- 1.8 yr). The estrogenic bioactivity in the prepubertal girls was significantly higher than in the boys, i.e. 3.53 +/- 2.23 pg x ml(-1) vs. 1.44 +/- 0.87 pg x ml(-1) (P < 0.01). A significant difference was found between the pre- and pubertal girls, i.e. 3.53 +/- 2.23 pg x ml(-1) vs. 26.77 +/- 18.32 pg x ml(-1) (P < 0.01). This ultrasensitive bioassay measures total estrogenic bioactivity of serum with very high sensitivity. It has numerous potential applications in pediatric and adult endocrinology. In addition, this assay may help to evaluate excess estrogenic activity related to aromatase overexpression or contamination by environmental chemicals.

Biological Assay↗
PubMed2002

McCune-Albright syndrome: molecular genetics.

McCune-Albright syndrome (MAS) is a rare disorder characterized by the association of precocious puberty (mostly in girls), polyostotic fibrous dysplasia and café-au-lait pigmented skin lesions. In addition to this classical triad, several endocrine disorders, all due to autonomous hormonal hyperproduction, can also be associated, such as pituitary adenomas secreting growth hormone, hyperthyroid goiters, or adrenal hyperplasia. The distribution pattern of skin lesions and the sporadic character of MAS have led to the hypothesis that this syndrome is due to a dominant somatic mutation early in the course of development. Furthermore, the diverse endocrine hyperactivity syndromes observed in MAS have in common the involvement of cells that respond to extracellular signaling by activating the adenyl cyclase system. The identification of somatic mutations of the Gsalpha gene have shown that MAS is due to a post-zygotic activating mutation of the Gsalpha subunit leading to a mosaic distribution of cells bearing constitutively active adenyl cyclase activity. In all patients reported to date, the mutation is a substitution of the arginine residue at position 201 most often into histidine or cysteine. We present here some of the results we have obtained in studying 80 patients presenting one or several signs of MCA for identification of the Arg201 mutation. We used a PCR-based method that allows selective enrichment of mutated DNA. This study, and data in the literature during the last decade, has widened the definition of MAS. Affections as clinically different as somatotropic or thyrotropic adenomas, isolated polyostotic fibrous dysplasia, isolated peripheral precocious puberty and the classic McCune-Albright syndrome all appear to be elements of a wide spectrum of disease based on the same molecular defect. The developmental moment at which the mutation occurs determines both the number of tissues affected and the severity of expression. The application of tools from molecular genetics to the study of this syndrome confirms their essential contribution to a deeper understanding of endocrine pathologies.

Child↗