14 research outputs found
A somatic mutation in the thyrotropin receptor gene in a patient with an autonomous nodule within a multinodular goiter
ABSTRACT Thyrotropin (TSH) is the prime regulator of thyroid cell growth and function and acts through the thyrotropin receptor (TSHR) located on the surface membrane of thyrocytes. Somatic heterozygous mutations that cause TSHR activation in the absence of TSH have been found in toxic adenomas and in hot nodules of multinodular goiters. Clinically and histologically heterogeneous nodules can share common gain-of-function mutations. Mutation prevalence varies greatly and is inversely related to iodine intake of the population. We report a Greek patient presenting with subclinical hyperthyroidism due to a fast-growing autonomous hyperplastic nodule in a long-standing multinodular goiter. Direct DNA sequencing showed that the hot nodule harbored a somatic heterozygous activating TSHR mutation: substitution of glutamine for leucine in the third transmembrane helix. This mutation (L512Q) was recently described in two solitary toxic adenomas. This report expands the spectrum of mutations shared by dissimilar hot nodules, supporting a common mechanism for nonautoimmune thyroid autonomy. The identification of the L512Q substitution demonstrates that gainof-function TSHR mutations are encountered in Greece, although iodine deficiency has been significantly corrected over the last three decades
Placental mRNA Expression of Neurokinin B Is Increased in PCOS Pregnancies with Female Offspring
Current research suggests that polycystic ovary syndrome (PCOS) might originate in utero and implicates the placenta in its pathogenesis. Kisspeptin (KISS1) and neurokinin B (NKB) are produced by the placenta in high amounts, and they have been implicated in several pregnancy complications associated with placental dysfunction. However, their placental expression has not been studied in PCOS. We isolated mRNA after delivery from the placentae of 31 PCOS and 37 control women with term, uncomplicated, singleton pregnancies. The expression of KISS1, NKB, and neurokinin receptors 1, 2, and 3 was analyzed with real-time polymerase chain reaction, using β-actin as the reference gene. Maternal serum and umbilical cord levels of total testosterone, sex hormone-binding globulin (SHBG), free androgen index (FAI), androstenedione, dehydroepiandrosterone sulfate (DHEAS), Anti-Mullerian hormone (AMH), and estradiol were also assessed. NKB placental mRNA expression was higher in PCOS women versus controls in pregnancies with female offspring. NKB expression depended on fetal gender, being higher in pregnancies with male fetuses, regardless of PCOS. NKB was positively correlated with umbilical cord FAI and AMH, and KISS1 was positively correlated with cord testosterone and FAI; there was also a strong positive correlation between NKB and KISS1 expression. Women with PCOS had higher serum AMH and FAI and lower SHBG than controls. Our findings indicate that NKB might be involved in the PCOS-related placental dysfunction and warrant further investigation. Studies assessing the placental expression of NKB should take fetal gender into consideration
Impact of estrogen receptor α gene and oxytocin receptor gene polymorphisms on female sexuality
Over the past decades, research attention has increasingly been paid to the neurobiological component of sexual behavior. The aim of the present study was to investigate the correlation of estrogen receptor α (ERA) gene polymorphism (rs2234693-PvuII) (T→C substitution) and oxytocin receptor gene polymorphism
(rs53576) (G→A substitution) with sexuality parameters of young, healthy women. One hundred thirty-three Greek heterosexual women, students in higher education institutions, 20–25 years of age, sexually active, with normal menstrual cycles
(28–35 days), were recruited in the study. Exclusion criteria were chronic and/or major psychiatric diseases, use of oral contraceptive pills (OCs), polycystic ovary syndrome (PCOS), thyroid diseases as well as drugs that are implicated in hypothalamus–pituitary–gonadal axis. T allele (wildtype) of rs2234693 (PvuII) polymorphism of ERA gene was correlated with increased levels of arousal and lubrication, whereas A allele (polymorphic) of rs53576 (OXTR) polymorphism was correlated with increased arousal levels. The simultaneous presence of both T allele of rs2234693 (PvuII) and A allele of rs53576 (OXTR) polymorphisms (T + A group) was correlated with increased arousal, orgasm levels as well as female sexual function index full score. To our knowledge, this is the first study to investigate the interaction between ERA and OXTR with regard to sexual function in women. Female sexuality is a complex behavioral trait that encompasses both biological and psychological components. It seems that variability in female sexual response stems from genetic variability that characterizes endocrine, neurotransmitter and central nervous system influences
Decreased active, total and altered active to total ghrelin ratio in normal weight women with the more severe form of polycystic ovary syndrome
Objective: To assess total, active and active to total serum ghrelin
ratio in normal weight women with polycystic ovary syndrome (PCOS) and
in healthy ovulatory control women.Study design: The study included 50
normal weight women with PCOS with a mean age of 23.70 +/- 4.99 years
and 10 control women with a mean age of 30 +/- 5.80 years. The diagnosis
of PCOS was based on the presence of biochemical hyperandrogenemia,
chronic anovulation and polycystic ovarian morphology according to the
Rotterdam ESHRE/ASRM-sponsored PCOS Consensus Workshop Group. Serum
total and active ghrelin were measured by RIA, using commercially
available kits.
Results: A significantly lower serum active/total ghrelin ratio was
noted in the more severe form of PCOS with hyperandrogenemia, chronic
anovulation and polycystic ovarian morphology. Both total and active
serum ghrelin levels were negatively correlated to hirsutism score, to
plasma glucose levels and to QUICKI and HOMA-IR indices of Insulin
Resistance. A statistically significant difference was detected between
the more severe and the milder forms of PCOS, concerning serum levels of
total ghrelin (p = 0.017), active ghrelin (p = 0.007) and the
active/total ghrelin ratio (p = 0.026).
Conclusions: The results of the present study demonstrate an altered
active to total ghrelin ratio, as well as a tendency towards lower both
total and active fasting serum ghrelin levels in normal weight PCOS,
more pronounced in the more severe forms of the syndrome. (C) 2009
Elsevier Ireland Ltd. All rights reserved
Despite a High Prevalence of Menstrual Disorders, Bone Health Is Improved at a Weight-Bearing Bone Site in World-Class Female Rhythmic Gymnasts
International audienc
Comparative functional analysis of two fibroblast growth factor receptor 1 (FGFR1) mutations affecting the same residue (R254W and R254Q) in isolated hypogonadotropic hypogonadism (IHH)
FGFR1 mutations have been identified in both Kallmann syndrome and
normosmic HH (nIHH). To date, few mutations in the FGFR1 gene have been
structurally or functionally characterized in vitro to identify
molecular mechanisms that contribute to the disease pathogenesis. We
attempted to define the in vitro functionality of two FGFR1 mutants
(R254W and R254Q), resulting from two different amino add substitutions
of the same residue, and to correlate the in vitro findings to the
patient phenotypes. Two unrelated GnRH deficient probands were found to
harbor mutations in FGFR1 (R254W and R254Q). Mutant signaling activity
and expression levels were evaluated in vitro and compared to a wild
type (WT) receptor. Signaling activity was determined by a FGF2/FGFR1
dependent transcription reporter assay. Receptor total expression levels
were assessed by Western blot and cell surface expression was measured
by a radiolabeled antibody binding assay. The R254W maximal receptor
signaling capacity was reduced by 45% (p<0.01) while R254Q activity was
not different from WT. However, both mutants displayed diminished total
protein expression levels (40 and 30% reduction relative to WT,
respectively), while protein maturation was unaffected. Accordingly,
cell surface expression levels of the mutant receptors were also
significantly reduced (35% p<0.01 and 15% p<0.05, respectively). The
p.R254W and p.R254Q are both loss-of-function mutations as demonstrated
by their reduced overall and cell surface expression levels suggesting a
deleterious effect on receptor folding and stability. It appears that a
tryptophan substitution at R254 is more disruptive to receptor structure
than the more conserved glutamine substitution. No clear correlation
between the severity of in vitro loss-of-function and phenotypic
presentation could be assigned. (C) 2012 Elsevier B.V. All rights
reserved