Participation of NADPH 4 oxidase in thyroid regulation

Different factors are involved in thyroid function and proliferation such as thyrotropin (TSH), insulin, growth factors, iodide, etc. TSH and IGF1/insulin increase proliferation rate and stimulate genes involved in thyroid differentiation. In the present study, we analyse the physiological regulation of NOX4 expression by TSH, insulin and iodine, and the role of NOX4 on thyroid genes expression. Differentiated rat thyroid cells (FRTL-5) were incubated in the presence or absence of TSH/insulin and TTF2, PAX8, TPO, NIS, NOX4, TGFβ1, FOXO1/3 mRNA levels were examined by Real Time PCR. We showed that TSH and insulin repress NOX4 expression and appears to be inversely correlated with some thyroid genes. SiRNA targeted knockdown of NOX4 increased mRNA levels of TGFβ1, TPO, PAX8, TTF2, FOXO1 and FOXO3. A PI3K inhibitor (LY294002), increases the expression of NIS, TTF2 and FOXO1/3, however PI3K/AKT pathway does not regulate NOX4 expression. We observed that iodine increased NOX4 expression and knockdown of NOX4 reduced ROS and reversed the inhibitory effect of iodine on NIS, TPO, PAX8 and TTF2 expression. Our findings provide strong evidence that NOX4 could be a novel signaling modulator of TSH/insulin pathway and would have a critical role in the autoregulatory mechanism induced by iodine.

Regulation of NADPH oxidase NOX4 by delta iodolactone (IL-δ) in thyroid cancer cells

INTRODUCTION

Iodine is not used only by the thyroid to synthesize thyroid hormones but also directly influences a number of thyroid parameters such as thyroid proliferation and function. Several iodinated lipids, biosynthesized by the thyroid, were postulated as intermediaries in the action of iodide. Among these, iodolactone (IL-δ) and 2-iodohexadecanal (2-IHDA) have shown to inhibit several thyroid parameters. The antiproliferative effect of IL-δ is not restricted to the thyroid gland. IL-δ exhibits anti-tumor properties in breast cancer, neuroblastoma, glioblastoma, melanoma and lung carcinoma cells suggesting that IL-δ could be used as a chemotherapeutic agent. Moreover in a colon cancer cell line (HT-29), IL-δ induced cell death, and this effect was mediated by reactive oxygen species (ROS) generation. The aim of the present study was to analyze the sources of reactive oxygen species induced by IL-δ and to explore the contribution of ROS induced by IL-δ on cell proliferation and apoptosis.

METHODOLOGY AND RESULTS

Cancer thyroid follicular (WRO) and papilar (TPC-1) cells lines were treated with IL-δ. Proliferation and apoptosis was analyzed. IL-δ caused a significant loss of cell viability on WRO and TPC-1 cells in a concentration dependent manner and induced apoptosis after 3 h of treatment. Furthermore, IL-δ (10 μM) increased ROS production (39% WRO and 20% TPC-1). The concomitant treatment of WRO and TPC-1 cells with Trolox or NAC plus IL-δ abrogated the augment of ROS induced by IL-δ exposure. Additionally Trolox and NAC reversed the effect of IL-δ on cell proliferation and apoptosis. Only in WRO cells IL-δ upregulates NADPH oxidase NOX4 expression, and siRNA targeted knock-down of NOX4 attenuates ROS production, apoptosis (p < 0.05) and the inhibitory effect of IL-δ on cell proliferation and PCNA expression (p < 0.05).

CONCLUSIONS

The antiproliferative and pro-apoptotic effect of IL-δ is mediated by different mechanisms and pathway involving different sources of ROS generation depending on the cellular context.

Emulsion polymerization of vinyl acetate: safe optimization of a hazardous complex process

Fast and exothermic discontinuous emulsion polymerization processes are particularly difficult to optimize from both safety and productivity point of view because of the occurrence of side undesired reactions (e.g. chain transfer to monomer, backbiting, propagation of tertiary radicals, termination by disproportion, etc.) and the hazards of boiling phenomena and stable foam formation under atmospheric pressure. Moreover, the relevant number of loading, heating and cooling steps, required before starting the monomer addition (that is, the desired reaction), makes a strict product quality reproducibility very difficult to obtain. Under these operating conditions, it is necessary to employ a suitable combined theoretical and experimental procedure able to detect the optimum process dosing time at both the laboratory and the industrial scale. In this work, it is shown how to use the topological criterion theory together with proper adiabatic calorimeter and RC1 experimental data to safely optimize the synthesis of polyvinyl acetate through the radical emulsion polymerization of vinyl acetate by the means of an indirectly cooled isoperibolic semibatch reactor.

Seminiferous tubule function in delayed-onset X-linked adrenal hypoplasia congenita associated with incomplete hypogonadotrophic hypogonadism

OBJECTIVE

X-linked adrenal hypoplasia congenita (AHC, OMIM 300200) due to mutations in the DAX-1 gene is frequently associated to hypogonadotrophic hypogonadism (HHG, OMIM 238320). Clinical variants with delayed-onset have been recognized. The objective of this study is to assess Sertoli cell function throughout pubertal development in patients with childhood-onset AHC due to stop mutations in the DAX-1 gene.

DESIGN

Observational follow-up study of gonadotrophin pulsatility pattern, and serum levels of antimüllerian hormone and inhibin B through pubertal development in these patients.

PATIENTS

Three patients belonging to two families with AHC were included in this study.

MEASUREMENTS

The gonadotrophic pattern, serum inhibin B and antimüllerian hormone were determined in relation to clinical Tanner stage of pubertal development.

RESULTS

One patient showed a marked elevation in serum FSH concomitantly with low inhibin B and antimüllerian hormone levels, indicating a primary testicular dysfunction. The other two patients showed a gonadotrophic pattern of HHG, and their serum levels of inhibin B and antimüllerian hormone also reflected a moderate primary testicular dysfunction. The three patients were azoospermic.

CONCLUSIONS

These cases give further insight into the clinical spectrum of phenotypes of the hypothalamic-pituitary-gonadal axis in patients with variants in hypogonadism associated with childhood-onset X-linked AHC due to DAX-1 mutations.

Partial defects in transcriptional activity of two novel DAX-1 mutations in childhood-onset adrenal hypoplasia congenita

OBJECTIVE

Mutations in DAX-1, an X-linked gene encoding an orphan nuclear receptor, have been associated with adrenal hypoplasia congenita and hypogonadotropic hypogonadism. Here we describe two novel DAX-1 mutations, Y214X and I361T, associated with childhood-onset primary adrenal failure. We aimed at analysing their effects on protein localization, transcriptional activity and propose a structural-function relationship.

DESIGN

We have directly sequenced the DAX-1 gene from PCR-amplified DNA. The effect of the mutations on protein localization was assessed by immunocytochemistry in transfected cells. The impact of mutations on transcriptional activity was determined by transfection using a StAR promoter-luciferase reporter system.

RESULTS

The mutation Y214X produces a protein lacking the C-terminal half of DAX-1. The other one, I361T, affects a highly conserved amino acid within the putative ligand-binding domain. The mutant Y214X displayed a wild-type subcellular localization while I361T was partially retained in the cytoplasm. Both mutants retained subtantial transcriptional repressive activity, compared to mutants producing early onset adrenal failure. Interestingly, I361T displayed similar in vitro transcriptional repressive activity to the mutant I439S previously described in a case of late-onset AHC. This shows that molecular alterations of DAX-1 leading to similar in vitro activities may result in very different ages of onset of adrenal failure, which suggests that additional genetic and epigenetic factors are important in determining the clinical course of AHC.

CONCLUSIONS

Our results help the understanding of structure-function relationships in the DAX-1 molecule, suggesting that the N-terminal domain is relatively autonomous and add credence to presumed molecular interactions within ligand binding domain of the protein.

Familial occurrence of the IMAGe association: additional clinical variants and a proposed mode of inheritance

The IMAGe (intrauterine growth retardation, metaphyseal dysplasia, adrenal hypoplasia congenita, genital anomalies) association (online inheritance in man 300290) is a recently reported disorder comprising intrauterine growth retardation (IUGR), metaphyseal dysplasia, adrenal hypoplasia, and genital anomalies. Four children (three males, one female) from a large pedigree (five generations) were studied. Additional members (n = 10), who died during the neonatal period, were born with IUGR and/or hyperpigmentation and are presumed to have been affected, too. All patients in this series were diagnosed during the newborn period. Minimal clinical features and laboratory findings differ with previously reported patients, suggesting variants in their clinical expression. Adrenal insufficiency was variable within patients. All had severe IUGR and marked postnatal growth failure. Sequence analysis of DNA using an automated cycle from two patients revealed no mutation in the dosage-sensitive sex reversal-adrenal hypoplasia congenita critical region on the X chromosome, gene 1. Analysis of the pedigree showed that the disease is inherited via the maternal line, even in the dead children with suspicion of the disease. Hence, the pattern of inheritance in this family of this unusual disorder might be explained in terms of the genomic imprinting hypothesis with expression through maternal transmission involving an autosomal gene. This transmission may have considerable implications for genetic counseling. Furthermore, pediatric endocrinologists must be aware of the possible occurrence of this life-threatening condition in the offspring of nonaffected women when related to a family member with the association of IUGR, metaphyseal dysplasia, adrenal hypoplasia congenita, genital anomalies.

Premature ovarian failure and forkhead transcription factor FOXL2: blepharophimosis-ptosis-epicanthus inversus syndrome and ovarian dysfunction

Recently the molecular basis of the blepharophimosis-ptosis-epicanthus inversus-syndrome (BPES), an autosomal dominant developmental disorder of the eyelids and ovary, was elucidated. This syndromic form of premature ovarian failure (POF) is caused by mutations in the gene encoding the forkhead transcription factor FOXL2. In this manuscript we review the clinical features of BPES, its molecular basis, the structural and functional characteristics of the FOXL2 gene and protein, and known animal models.

X-linked chronic granulomatous disease: first report of mutations in patients of Argentina

BACKGROUND

Chronic granulomatous disease (CGD) is a primary immunodeficiency due to absent or decreased NADPH oxidase activity in phagocytic cells. The X-linked form of the disease (X-CGD) arises from mutations in the CYBB gene, which encodes the 91-kD glycoprotein gp91(phox), the largest component of the oxidase.

METHODS

The authors recently started the molecular characterization of X-CGD in 18 patients reported to the Argentinean Registry of Primary Immunodeficiency Diseases. The authors reviewed data from clinical records to examine the relationship of clinical presentation and the type of mutations responsible for the genotype.

RESULTS

The frequency and type of infections present in these patients were similar to prior reports. However, pulmonary tuberculosis was observed in the group as well as unusual complications such as eosinophilic cystitis, hepatic abscess with cholangitis, and chronic orchitis. Eleven different mutations in the CYBB gene were identified, and seven of them were novel. The types of mutations were intronic, single-nucleotide substitution resulting in nonsense or missense codons and one or two nucleotide deletions resulting in frameshifts. Molecular studies of 18 mothers revealed X-CGD carrier status in all but 2.

CONCLUSIONS

No correlation existed between the type of mutation and the clinical phenotype of the disease: the molecular defects identified resulted in no expression of the flavocytochrome b558 in patients' neutrophils, leading to the X91(o)-CGD phenotype. The lack of gp91(phox) protein could explain the early onset and the severity of the clinical manifestations of CGD in this group of patients from Argentina.

A normative study of a shorter version of Raven's progressive matrices 1938

A shorter four-set (A, B, C, D) version of Raven's progressive matrices 1938 (PM38) has gained increasing use in neuropsychological assessment. No normative data spanning across a wide age range are, however, available. This study collected norms for the shorter version of PM38, established an inferential cut-off value and derived equivalent scores in a sample of 248 individuals from 20 to 89 years of age, evenly distributed across sex, age and education levels. Results showed significant effects of age and education but no effect of sex on performance. These normative data will complement existing norms for other tests, will increase the wealth of neuropsychological tools for which normative data are available for the Italian population, and may be useful in the early detection of individuals at risk of developing dementia.

Molecular aspects of female and male gonadal development in mammals

In mammals, the choice between male or female development is genetically determined. Sex determination takes place when the embryonic gonad becomes either a testis or an ovary. This process is directed by genes that have been discovered by genetic analysis of sex-reversed patients and confirmed by knock-out experiments in mice. The testis-determining pathway is better known than the ovary pathway. SRY, a gene located on the Y chromosome, triggers a complex genetic cascade leading to testicular differentiation. In this cascade, two genes play a crucial role in male differentiation, SOX9 and FGF9, which contribute to testicular cord formation. However, only a minority of 46,XY sex-reversed patients can be explained by mutations in known genes such as SRY, SOX9, WT1 and SF1, suggesting that other genes influencing sex determination are yet to be discovered. In females, some rare genes that induce ovarian failure or female-to-male sex-reversal, have been found through gene-targeted inactivation in mice or positional cloning of mutations in humans and goats. In both sexes, genetic analysis of sex-reversed individuals (XX males, XX and XY hermaphrodites and XY with complete or partial dysgenesis) remains an approach of choice to isolate new genes involved in sex determination.

46,XX male: clinical, hormonal/genetic findings

The clinical genetics and hormonal status of the 46,XX male is well determined. This is a rare condition that affects one out 20,000 male births. This study evaluates 5 infertile patients with no abnormalities in sex definition in whom we noted variants in their phenotype, like small penis, hypospadias, cryptorchidism, flat scrotum, and in some of them small testis. Only one patient had gynecomastia; all patients were azoospermics. Otherwise, serum FSH levels were elevated in only 3 patients and LH in 2. Serum levels of testosterone were low in 3 cases. Karyotype was 46,XX without evidence of mosaicism. PCR of genomic DNA studied revealed only the presence of SRY gene. DNA material in the Y chromosome was similar in all patients, but this did not correlate with the phenotype findings and hormonal levels in all of them. Testing new chromosomal markers should be of great value in the definition of clinical difference.

47,XYY karyotype and normal SRY in a patient with a female phenotype

A rare case of a female patient with a 47,XYY karyotype is described. She had normal female external genitalia, bilateral testes, rudimentary Fallopian tubes and no uterus. Molecular analysis revealed a normal SRY encoding sequence. The possible events in the etiology of this sex reversal entity are discussed.

PCR analysis of Y-chromosome sequences in a 45,X male patient and a review of the literature

The 45,X karyotype is usually associated with Turner syndrome, while male phenotype is exceptional. The authors report a 45,X male patient with normal external genitalia and sex behavior, but who was azoospermic. He had a normally developed musculature and pilose distribution, testicular volume of 15 mL and no gynecomastia but clinical stigmata of Turner syndrome (short stature, short neck and 4th metacarpal bones) and azoospermia. Hormonal plasma levels of testosterone, estradiol, prolactin, and gonadotrophins were within the normal range as was the response of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) (30 and 60 min) after 100 microg iv of LH-RH administration. Testicular biopsy could not be performed. Karyotype was 45,X without evidence of mosaicism. Polymerase chain reaction of genomnic DNA studied with 12 different sequences of Y chromosome revealed only the presence of SRY gene (testis determining factor). It is possible that SRY/autosomal translocation had occurred in this patient. The study of 45,X male should be of great value in elucidating the complex mechanisms involved in normal male sex differentiation.

Randomised, double-blind, placebo-controlled study of pivagabine in neurasthenia

One hundred and eighteen patients with neurasthenia, as defined by ICD 10 (International Classification of Diseases), participated in a randomised, double-blind, placebo-controlled trial of pivagabine (4-[(2,2-dimethyl-1-oxopropyl)amino]butanoic acid, CAS 69542-93-4, Tonerg). Pivagabine 1800 mg/d was administered orally for four weeks. At the end of the trial, active medication was significantly superior to placebo on the Clinical Global Impression (CGI) improvement of illness scale. In addition, pivagabine treatment reduced the physical and mental fatigability of patients, and increased their sense of well-being.

Brief clinical report: interstitial deletion of the long arm of chromosome 4, del(4)(q28-->q31.3)

Interstitial deletions of the long arm of chromosome 4 are rare. Different breakpoints are involved. Only one of the patients had a very similar deletion to that of the present case. Both had low birth weight at term; weight, length and head circumference less than the third centile; epicanthic folds; apparently low-set abnormal ears; broad nasal bridge; micrognathia; hypoplastic nails; delayed psychomotor development; and mild mental retardation.