Anti-Müllerian hormone and letrozole levels in boys with constitutional delay of growth and puberty treated with letrozole or testosterone.

STUDY QUESTION: Does treatment of constitutional delay of growth and puberty (CDGP) in boys with aromatase inhibitor letrozole (Lz) or conventional low-dose testosterone (T) have differing effects on developing seminiferous epithelium? SUMMARY ANSWER: Anti-Müllerian hormone (AMH) declined similarly in both treatment groups, and the two Sertoli cell-derived markers (AMH and inhibin B (iB)) exhibited differing responses to changes in gonadotrophin milieu. WHAT IS KNOWN ALREADY: Boys with CDGP may benefit from puberty-inducing medication. Peroral Lz activates gonadotrophin secretion, whereas intramuscular low-dose T may transiently suppress gonadotrophins and iB. STUDY DESIGN, SIZE, DURATION: Sera of 28 boys with CDGP who participated in a randomised, controlled, open-label trial at four paediatric centres in Finland between August 2013 and January 2017 were analysed. The patients were randomly assigned to receive either Lz (2.5 mg/day) (n = 15) or T (1 mg/kg/month) (n = 13) for 6 months. PARTICIPANTS/MATERIALS, SETTING, METHODS: The 28 patients were at least 14 years of age, showed first signs of puberty, wanted medical attention for CDGP and were evaluated at 0, 3, 6 and 12 months of visits. AMH levels were measured with an electrochemiluminescence immunoassay and Lz levels with liquid chromatography coupled with tandem mass spectrometry. MAIN RESULTS AND THE ROLE OF CHANCE: AMH levels decreased in both treatment groups during the 12-month follow-up (P < 0.0001). Between 0 and 3 months, the changes in gonadotrophin levels (increase in the Lz group, decrease in the T group) correlated strongly with the changes in levels of iB (FSH vs iB, r = 0.55, P = 0.002; LH vs iB, r = 0.72, P < 0.0001), but not with the changes in AMH (P = NS). At 12 months, AMH levels did not differ between the groups (P = NS). Serum Lz levels (range, 124-1262 nmol/L) were largely explained by the Lz dose per weight (at 3 months r = 0.62, P = 0.01; at 6 months r = 0.52, P = 0.05). Lz levels did not associate with changes in indices of hypothalamic-pituitary-gonadal axis activity or Sertoli cell markers (in all, P = NS). LIMITATIONS, REASONS FOR CAUTION: The original trial was not blinded for practical reasons and included a limited number of participants. WIDER IMPLICATIONS OF THE FINDINGS: In early puberty, treatment-induced gonadotrophin stimulus was unable to counteract the androgen-mediated decrease in AMH, while changes in iB levels were associated with changes in gonadotrophin levels. AMH decreased similarly in both groups during the treatment, reassuring safety of developing seminiferous epithelium in both treatment approaches. Since a fixed dose of Lz induced variable serum Lz levels with a desired puberty-promoting effect in all boys, more research is needed to aim at a minimal efficient dose per weight. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the Academy of Finland, the Foundation for Pediatric Research, the Emil Aaltonen Foundation, Sigrid Juselius Foundation and Helsinki University Hospital Research Funds. The authors have nothing to disclose. TRIAL REGISTRATION NUMBER: NCT01797718.

The effect of glycaemic control on the quantitative characteristics of retinopathy lesions in patients with type 2 diabetes mellitus: 10-year follow-up study.

BACKGROUND: Diabetic retinopathy (DR) represents a common complication of type 2 diabetes mellitus. Appearance of DR lesions such as microaneurysms, haemorrhages, hard and soft exudates, IRMA and neovascularisation reflect the severity of DR. The aim of our study was to investigate the association of selected glycaemic parameters with particular DR abnormalities and their characteristics in patients with type 2 diabetes. METHODS: Eighty-three middle-aged patients with newly diagnosed type 2 diabetes mellitus participated in this 10-year prospective study. The glycaemic parameters such as glycated haemoglobin A1c (HbA1c), fasting blood/plasma glucose as well as 1- and 2-hour post-load glucose values were recorded at baseline, 5-year and 10-year follow-up. The fundus photographs were taken at baseline and then at 5-year and 10-year follow-ups and used for quantitative evaluation. RESULTS: Statistically significant positive correlations were found between all investigated 5-year glucose values and the extent of DR lesions at 10-year follow-up (p < 0.003). The 1- and 2-hour post-load glucose values correlated with the DR lesions with the highest significance (p

Bone morphogenetic protein-6 is a marker of serous acinar cell differentiation in normal and neoplastic human salivary gland.

Bone morphogenetic protein (BMP-6, also known as vegetal-pale-gene-related and decaplentaplegic-vegetal-related) is a member of the transforming growth factor-beta superfamily of multifunctional signaling molecules. BMP-6 appears to play various biological roles in developing tissues, including regulation of epithelial differentiation. To study the possible involvement of BMP-6 in normal and neoplastic human salivary glands, we compared its mRNA and protein expression in 4 fetal and 15 adult salivary glands and in 22 benign and 32 malignant salivary gland tumors. In situ hybridization and Northern blot analysis indicated that BMP-6 transcripts are expressed at low levels in acinar cells of adult submandibular glands but not in ductal or stromal cells. BMP-6 was immunolocated specifically in serous acini of parotid and submandibular glands. None was found in primitive fetal acini or any other types of cell in adult salivary glands, including mucous acini and epithelial cells of intercalated, striated, and excretory ducts. All 16 cases of acinic cell carcinoma consistently exhibited cytoplasmic BMP-6 staining in the acinar tumor cells. Other cell types in these tumors, including intercalated duct-like cells, clear, vacuolated cells, and nonspecific glandular cells, exhibited no cytoplasmic BMP-6 staining. Other benign and malignant salivary gland tumors lacked BMP-6 immunoreactivity, except in areas of squamous differentiation. The results indicate that in salivary glands, BMP-6 expression is uniquely associated with acinar cell differentiation and suggest that BMP-6 may play a role in salivary gland function. More importantly, our experience of differential diagnostic problems related to salivary gland tumors suggests that the demonstration of consistent and specific BMP-6 immunoreactivity in acinic cell carcinoma is likely to be of clinical value.

RASSF1A promoter region CpG island hypermethylation in phaeochromocytomas and neuroblastoma tumours.

Deletions of chromosome 3p are frequent in many types of neoplasia including neural crest tumours such as neuroblastoma (NB) and phaeochromocytoma. Recently we isolated several candidate tumour suppressor genes (TSGs) from a 120 kb critical interval at 3p21.3 defined by overlapping homozygous deletions in lung and breast tumour lines. Although mutation analysis of candidate TSGs in lung and breast cancers revealed only rare mutations, expression of one of the genes (RASSF1A) was absent in the majority of lung tumour cell lines analysed. Subsequently methylation of a CpG island in the promoter region of RASSF1A was demonstrated in a majority of small cell lung carcinomas and to a lesser extent in non-small cell lung carcinomas. To investigate the role of 3p TSGs in neural crest tumours, we (a) analysed phaeochromocytomas for 3p allele loss (n=41) and RASSF1A methylation (n=23) and (b) investigated 67 neuroblastomas for RASSF1A inactivation. 46% of phaeochromocytomas showed 3p allele loss (38.5% at 3p21.3). RASSF1A promoter region hypermethylation was found in 22% (5/23) of sporadic phaeochromocytomas and in 55% (37/67) of neuroblastomas analysed but RASSF1A mutations were not identified. In two neuroblastoma cell lines, methylation of RASSF1A correlated with loss of RASSF1A expression and RASSF1A expression was restored after treatment with the demethylating agent 5-azacytidine. As frequent methylation of the CASP8 gene has also been reported in neuroblastoma, we investigated whether RASSF1A and CASP8 methylation were independent or related events. CASP8 methylation was detected in 56% of neuroblastomas with RASSF1A methylation and 17% without RASSF1A methylation (P=0.0031). These results indicate that (a) RASSF1A inactivation by hypermethylation is a frequent event in neural crest tumorigenesis, particularly neuroblastoma, and that RASSF1A is a candidate 3p21.3 neuroblastoma TSG and (b) a subset of neuroblastomas may be characterized by a CpG island methylator phenotype.

Interferon-gamma inhibits steroidogenesis and accumulation of mRNA of the steroidogenic enzymes P450scc and P450c17 in cultured porcine Leydig cells.

The inhibitory effects of recombinant porcine interferon-gamma (IFN gamma) on human CG (hCG)-stimulated testosterone production, and on mRNA concentrations of cholesterol side-chain cleavage (P450scc) and 17 alpha-hydroxylase/C17-20lyase (P450c 17) were investigated using porcine primary Leydig cell culture as a model. After preincubation of Leydig cells for 24 h with 1000 pM IFN gamma, hCG-stimulated (10 ng/ml, 2 h) testosterone production was inhibited by 50%, whereas no significant changes were seen in hCG-stimulated cAMP production. Incubation with 10 microM 5-cholestene-3 beta,22(R)-diol or 10 microM 5-cholestene-3 beta,20 alpha-diol together with hCG (10 ng/ml, 2 h) reversed most of the inhibitory effect of IFN gamma, suggesting that IFN gamma inhibits P450scc activity, possibly by inhibiting the substrate (cholesterol) availability for P450scc. Incubation with IFN gamma also decreased basal concentrations of P450scc (45%) and P450c 17 (35%) mRNA, although these changes probably did not contribute to the decreased testosterone production. Long-term treatment with hCG (100 ng/ml, 24 h) increased P450scc mRNA (3- to 4-fold) and P450c 17 mRNA (4- to 5-fold) concentrations. Simultaneous treatment with IFN gamma attenuated these hCG-induced increases in P450scc mRNA (50%) and P450c 17 mRNA (40-100%) concentrations, as well as in testosterone production (77%). This inhibition of testosterone production could only be partly reversed by the hydroxylated cholesterol derivatives. This suggests that in addition to possible suppression of cholesterol availability, decreased P450scc and/or P450c 17 activities (through decreased mRNA concentrations) were also involved in the IFN gamma suppressed steroidogenic capacity of porcine Leydig cells during long-term hCG stimulation.

Human müllerian inhibitory factor messenger ribonucleic acid is hormonally regulated in the fetal testis and in adult granulosa cells.

The regression of the Müllerian ducts (the embryologic precursor of uterus, vagina, and Fallopian tubes) in the male fetus is caused by Müllerian inhibitory factor (MIF), a glycoprotein produced by fetal Sertoli cells. Although this Müllerian duct involution is complete before midgestation, the amount of MIF mRNA did not vary among 25 human fetal testis samples from 13 to 25.8 weeks of gestation. In cultured 20-week human testis cells, cAMP increased MIF mRNA 8.3-fold, but the human gonadotropins FSH and CG had no effect. In cultured adult human granulosa cells, CG and cAMP increased MIF mRNA accumulation to 430% and 890%, respectively, but FSH had no effect. The expression and hormonal regulation of MIF mRNA in midgestation testes and in adult granulosa cells indicate that MIF has physiological roles in the human gonad other than Müllerian duct regression.

EGF receptor and its ligands, EGF and TGF-alpha, in developing and neoplastic human odontogenic tissues.

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) regulate cell proliferation and functional maturation through the EGF receptor (EGF-R). Their roles in human tooth development and odontogenic tumorigenesis have not been explored. We studied the expression of EGF, TGF-alpha and EGF-R in human fetal teeth (cap stage to early hard tissue formation) and various odontogenic tumors. EGF-R mRNA and immunoreactive cells were mostly located in odontogenic epithelium. EGF-R expression was subject to temporospatial variation at different stages of tooth development. EGF and TGF-alpha mRNAs were detected in fetal teeth only by the reverse transcription polymerase chain reaction (RT-PCR). However, EGF and TGF-alpha immunoreactive cells were demonstrated in epithelial elements of tooth germ, suggesting that the peptides partially originate from non-odontogenic sources. In odontogenic tumors, EGF-R mRNA and immunoreactivity were confined to neoplastic epithelium. Transcripts for TGF-alpha but not for EGF were detected in tumors of odontogenic epithelial, epithelial-ectomesenchymal and ectomesenchymal origins. It is concluded that regulation of EGF-R expression is developmentally regulated in human odontogenesis. Furthermore, the odontogenic epithelium is the main target tissue for both EGF and TGF-alpha during tooth development. TGF-alpha and its receptor may also be involved in odontogenic tumorigenesis.

Impaired development of bone mineral density during chemotherapy: a prospective analysis of 46 children newly diagnosed with cancer.

Osteopenia and osteoporosis are becoming increasingly recognized in children with cancer, though reasons for these changes are poorly understood. The purpose of the present study was to evaluate longitudinal changes in bone mineral density (BMD) and bone turnover in newly diagnosed children with a malignancy. Lumbar spine (L2-L4) and femoral neck bone mineral density (BMDareal, g/cm2) was measured by dual-energy X-ray absorptiometry in 46 children (age 2.9-16.0, median 8.0 years; 15 leukemias, 12 lymphomas, 19 solid tumors) at diagnosis, and after 6 months from the baseline. The apparent volumetric bone mineral density (BMDvol) was calculated to minimize the effect of bone size on BMD. Serum levels of osteocalcin (OC), type I collagen carboxy-terminal propeptide (PICP), and type I collagen carboxy-terminal telopeptide (ICTP) were analyzed at diagnosis, and during a 6-month follow-up. A significant decrease in lumbar BMDvol (-2.1%, p < 0.05), and in femoral BMDareal (-9.9%, p = 0.0001) and BMDvol (-8.5%, p = 0.0001) was observed after 6 months when compared with baseline measurements. The markers of bone formation (PICP, OC) were significantly decreased, and the marker of bone resorption (ICTP) was significantly increased at diagnosis as compared with normal values. By the end the follow-up, the levels of PICP and OC were normalized, whereas the level of ICTP continued to increase indicating that there was a negative balance in bone turnover. A deficient accumulation of bone mass might predispose children with a malignancy to impaired development of peak bone mass. A controlled study determining the benefits of an early intervention on bone turnover should be considered in these patients.

Regulation of aromatase cytochrome P-450 and 17 beta-hydroxysteroid dehydrogenase messenger ribonucleic acid levels in choriocarcinoma cells.

In human placenta the enzyme complex aromatase catalyzes the conversion of androgens to estrogens and 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) mediates the reversible interconversion of, e.g. estrone to estradiol. We studied the effects of cholera toxin (CT), an activator of adenylate cyclase, and 12-O-tetradecanoyl phorbol 13-acetate (TPA), a phorbol ester protein kinase C activator, on the levels of messenger (m) RNAs encoding aromatase cytochome P-450 (P-450AROM) and 17 beta-HSD in cultured JEG-3 choriocarcinoma cells. With the use of oligonucleotide probes designed according to known complementary DNA sequences, hybridizable mRNA transcripts of 3.0, 2.4, and 1.6 kilobases for P-450AROM were found in Northern blot analysis of JEG-3 cell RNA. A single 1.4-kilobase transcript was detected for 17 beta-HSD. Time-dependent increases in P-450AROM mRNA levels in JEG-3 cells were observed for both CT and TPA with maximal effects at 24-48 h. CT and TPA increased P-450AROM mRNA levels in a concentration-dependent manner. The maximal effects, about 4.8-fold and 3.3-fold stimulations above basal levels, were obtained with 10 ng/ml of CT and 100 ng/ml of TPA, respectively. The effects of CT and TPA were additive. CT induced 17 beta-HSD mRNA levels in a time- and concentration-dependent manner and its maximal effect of 10.1-fold above basal levels was obtained within a similar time and concentration-dependence as for P-450AROM mRNA. TPA itself had no clear effect but it approximately doubled the effect of CT on 17 beta-HSD mRNA expression. Inhibition of protein synthesis by cycloheximide decreased basal, CT and TPA stimulated P-450AROM mRNA levels but increased the expression of 17 beta-HSD mRNA. This result is consistent with the hypothesis that induction of P-450AROM gene expression is mediated by a labile protein regulator resembling to most other steroidogenic P-450 enzymes, whereas 17 beta-HSD as a non-P450 enzyme appears to be controlled in a different manner. The present results suggest that: 1) induction of P-450AROM mRNA may at least partly be responsible for our previously reported increases in the rate of conversion of androgens to estrogens by CT and TPA in JEG-3 cells; 2) 17 beta-HSD mRNA expression is mainly controlled through a cAMP-dependent mechanism in contrast to the multifactorial control of P-450AROM mRNA; and 3) protein synthesis inhibition by cycloheximide has opposite effects on the mRNA levels of these two key enzymes in placental estrogen metabolism.

Interaction of phorbol ester and adrenocorticotropin in the regulation of steroidogenic P450 genes in human fetal and adult adrenal cell cultures.

The role of protein kinase-C-dependent mechanisms in steroidogenic enzyme gene expression was studied in primary cultures of human fetal and adult adrenals. Cells were first cultured for 7-10 days and then stimulated with ACTH or 12-O-tetradecanoyl phorbol-13-acetate (TPA), a protein kinase-C activator, for 1-2 days. Cytoplasmic RNA was extracted and analyzed by Northern and dot blotting with 32P-labeled cDNA probes for P450scc (cholesterol side-chain cleavage enzyme/20,22-desmolase), P450c17 (17 alpha-hydroxylase/17,20-lyase), and P450c21 (21-hydroxylase); for P450c11 (11 beta-hydroxylase/18-hydroxylase/18-methyl oxidase), a 30-mer oligonucleotide was used as a probe. ACTH (200 ng/ml) increased the accumulation of all of the studied steroidogenic enzyme mRNAs in both fetal and adult cultures by several-fold. TPA inhibited this accumulation in a dose-dependent manner (0.01-100 ng/ml), whereas the inactive phorbol ester 4 alpha-phorbol-12,13-didecanoate was without effect. On the other hand, in the absence of ACTH, TPA slightly increased all steroidogenic P450 mRNAs in adult cultures. In fetal cultures TPA slightly increased P450scc, P450c11, and P450c21 mRNA levels, whereas it decreased P450c17 mRNA. (Bu)2cAMP and cholera toxin increased steroidogenic enzyme mRNAs such as ACTH. TPA down-regulated (Bu)2cAMP- and cholera toxin-induced P450mRNAs in the same way as ACTH-induced mRNAs. The secretion of ACTH-stimulated cortisol, dehydroepiandrosterone sulfate, and aldosterone was decreased by TPA in both fetal and adult cultures. The basal steroid production was slightly increased by TPA in both culture types. The changes in steroid production correlated well with the alterations in the steroidogenic enzyme gene expression. Our results show that the inhibitory effect of TPA on ACTH-stimulated adrenal steroidogenesis is mediated at the mRNA level of steroidogenic enzymes. Thus, it seems likely that both protein kinase-C- and cAMP-dependent mechanisms are involved in the long term maintenance of steroidogenic enzymes and hormone production in adrenocortical cells.

Tumor necrosis factor as a potent inhibitor of adrenocorticotropin-induced cortisol production and steroidogenic P450 enzyme gene expression in cultured human fetal adrenal cells.

We have previously demonstrated that tumor necrosis factor alpha (TNF-alpha), a multifunctional cytokine mainly produced by activated monocytes, inhibits the ACTH-induced production of cortisol in cultures of human fetal adrenals. To clarify the molecular basis of this suppression, we investigated the effect of recombinant TNF-alpha (rTNF-alpha) on the messenger RNAs (mRNAs) for adrenal cytochrome P450 oxidases, P450scc (cholesterol side-chain cleavage enzyme/20.22-desmolase), P450c11 (11 beta-hydroxylase/18-hydroxylase/18-methyl oxidase), P450c17 (17 alpha-hydroxylase/17,20-lyase), and P450c21 (21-hydroxylase). Northern and dot blot experiments showed that 36 h incubation of primary cultures of human fetal adrenals with ACTH (200 ng/ml) increased the levels of all P450 enzymes severalfold. Preincubation of the cultures with rTNF-alpha at concentrations ranging from 0.1-100 ng/ml produced a dose-dependent inhibition of the ACTH-induced accumulation of all P450 mRNAs. The decrease in the expression of genes for steroidogenic enzymes was accompanied by a similar decrease in the production of cortisol but not in that of dehydroepiandrosterone sulphate nor androstenedione. Neither the basal expression of P450 enzymes nor the basal secretion of the steroids was significantly altered by 10 ng/ml of rTNF-alpha. rTNF-alpha did not affect the level of actin mRNA, the cell viability, nor the cell number. All the effects brought about by rTNF-alpha could be neutralized by addition of monoclonal anti-TNF-alpha antibody. These results show that TNF-alpha suppresses the synthesis of cortisol and shifts the steroid secretory pattern towards androgen production at least partly by suppressing the accumulation of mRNAs for adrenal cytochrome P450 oxidases.

Corticosterone regulates cell proliferation and cytochrome P450 cholesterol side-chain cleavage enzyme messenger ribonucleic acid expression in primary cultures of fetal rat adrenals.

Glucocorticoids are known to inhibit growth in many different cell types. Although corticosterone is secreted by the adrenal cortex, its direct effect on the growth of different zones is poorly determined. We studied the effects of corticosterone on cell proliferation and cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc; the rate-limiting step in adrenal steroidogenesis) messenger RNA (mRNA) accumulation in primary cultures of fetal rat adrenals. Adrenocortical cells, grown in the absence of ACTH for 3 weeks, possess typical features of zona glomerulosa cells. These cells differentiate into fasciculata-type cells and undergo biphasic proliferation when stimulated with ACTH. The primary antimitogenic phase of 24 h is followed by rapidly increased bromodeoxyuridine incorporation after 72 h of ACTH treatment. If the treatment is continued, the proliferation decreases again, but remains higher than the proliferation of the untreated cells. Undifferentiated zona glomerulosa-type cells secrete very low amounts of corticosterone. The 10% basal proliferation was not affected if exogenous corticosterone was added. However, if corticosterone was combined with ACTH for 3 days, it blocked the stimulatory growth effect of ACTH dose dependently. Etomidate, an inhibitor of steroidogenic enzymes, completely blocked corticosterone secretion. In our cultures it inhibited 50% of the proliferation of the zona glomerulosa-type cells. However, its effect was totally opposite in long term ACTH-treated cultures; in these fasciculata-type cells, etomidate stimulated the proliferation rate 3-fold. P450scc gene expression was low in undifferentiated zona glomerulosa-like cells. ACTH stimulation increased P450scc mRNA expression 10-fold. Exogenous corticosterone inhibited ACTH-induced P450scc mRNA accumulation by 50%, whereas etomidate doubled it. Our data suggest that a low corticosterone concentration supports the proliferation of undifferentiated zona glomerulosa-type cells, whereas a high corticosterone concentration inhibits the proliferation of differentiated zona fasciculata-type cells. In addition, a high corticosterone concentration may inhibit steroidogenesis by reducing P450scc expression. Thus, corticosterone may be an important modulator of adrenocortical cell proliferation and steroidogenesis in different zones of the adrenal cortex.

Differential response of luteinizing hormone receptor and steroidogenic enzyme gene expression to human chorionic gonadotropin stimulation in the neonatal and adult rat testis.

To study further the functional differences of the fetal-neonatal and adult growth phases of Leydig cells, neonatal (5-day-old) and adult (60-day-old) male rats were challenged with a 600 IU/kg injection of human CG (hCG). Certain Leydig cell responses were monitored 1, 2, and 3 days after the hCG injection. The down-regulation of LH receptors and blockage of the 17-hydroxylase/C17-20 lyase step in adult testis, and the absence of these responses in neonatal testis were confirmed. Novel data were obtained on concomitant responses of LH receptor and steroidogenic enzyme messenger RNAs (mRNAs). The LH receptor mRNA was increased 4-5-fold by 2 days after hCG injection in the neonatal testis (P less than 0.05), but in the adult was decreased during all 3 days by 50% (P less than 0.05). The mRNA level of the cytochrome P450 for cholesterol side chain cleavage responded similarly at both ages, with a 180-260% increase during 2 and 3 days (P less than 0.05-0.01). In contrast, the 17-hydroxylase/17,20-lyase cytochrome P450 mRNAs displayed opposite responses, increasing 4.5-fold in 2 days (P less than 0.01) in the neonates, but decreasing by 80% in 1 day in the adults (P less than 0.01). No response of the aromatase cytochrome P450 mRNA to hCG stimulation was found at either age studied. These results demonstrate that the functional differences of the neonatal and adult Leydig cells to high gonadotropic stimulation occur at the level of expression of specific genes, including those of the LH receptor and the 17-hydroxylase/17,20-lyase cytochrome P450. Although aromatization of testicular androgens has been suggested to mediate the blockade of the 17-hydroxylase/C17-20 lyase step in adult testes, altered steady state levels of aromatase mRNA are not involved in this response. LH receptor mRNA decreases in adult rat testis in response to treatment with high levels of hCG. Thus, this phenomenon of down-regulation of membrane receptors includes a decreased LH receptor mRNA as well as cellular internalization of the existing receptors.

Insulin-like growth factor (IGF) binding protein from human decidua inhibits the binding and biological action of IGF-I in cultured choriocarcinoma cells.

The placenta expresses genes for insulin-like growth factors (IGFs) and possesses IGF-receptors, suggesting that placental growth is regulated by IGFs in an autocrine manner. We have previously shown that human decidua, but not placenta, synthesizes and secretes a 34 K IGF-binding protein (34 K IGF-BP) called placental protein 12. We now used human choriocarcinoma JEG-3 cell monolayer cultures and recombinant (Thr59)IGF-I as a model to study whether the decidual 34 K IGF-BP is able to modulate the receptor binding and biological activity of IGFs in trophoblasts. JEG-3 cells, which possess type I IGF receptors, were unable to produce IGF-BPs. Purified 34 K IGF-BP specifically bound [125I]iodo-(Thr59)IGF-I. Multiplication-stimulating activity had 2.5% the potency of (Thr59)IGF-I, and insulin had no effect on the binding of [125I] iodo-(Thr59)IGF-I. 34 K IGF-BP inhibited the binding of [125I] iodo-(Thr59)IGF-I to JEG-3 monolayers in a concentration-dependent manner by forming with the tracer a soluble complex that could not bind to the cell surface as demonstrated by competitive binding and cross-linking experiments. After incubating the cell monolayers with [125I]iodo-(Thr59)IGF-I in the presence of purified binding protein, followed by cross-linking, no affinity labeled bands were seen on autoradiography. In contrast, an intensely labeled band at 40 K was detected when the incubation medium was analyzed, suggesting that (Thr59)IGF-I and 34 K IGF-BP formed a complex in a 1:1 molar ratio. Also, 34 K IGF-BP inhibited both basal and IGF-I-stimulated uptake of alpha-[3H]aminoisobutyric acid in JEG-3 cells. RNA analysis revealed that IGF-II is expressed in JEG-3 cells. We conclude that decidual 34 K IGF-BP inhibits the cellular binding and biological action of IGFs in JEG-3 cells. Our data show that JEG-3 cells represent a cell type that can produce IGF, but not IGF-BPs. These cells may thus provide a useful model system for a better understanding of autocrine growth regulation mediated by the IGFs.

Parallel regulation of parentally imprinted H19 and insulin-like growth factor-II genes in cultured human fetal adrenal cells.

Adjacent, parentally imprinted, insulin-like growth factor-II (IGF-II) and H19 genes are highly expressed during embryogenesis and are important for fetal growth. Human fetal adrenals express abundantly both IGF-II and H19 genes. To clarify the significance and regulation of the H19 gene, we studied its expression in fetal adrenals. In situ hybridization experiments showed H19 RNA expression throughout the fetal adrenal cortex, with slightly higher expression in the outer definitive (adult) than in the inner fetal zone. In primary cultures of fetal adrenal cells, ACTH and other activators of the protein kinase-A signal transduction pathway increased both H19 and IGF-II RNA accumulation 1.7- to 10-fold. Staurosporine, a protein kinase-C inhibitor, increased H19 and IGF-II RNA to the same extent as did ACTH. The protein kinase-C activator 12-O-tetradecanoyl phorbol-13-acetate and cytokines, tumor necrosis factor-alpha and interferon-gamma, inhibited H19 and IGF-II RNA accumulation. Transforming growth factor-beta 1 caused a decrease in levels of H19 and IGF-II RNA, whereas the IGFs caused a slight increase. Our data show parallel multifactorial regulation of H19 and IGF-II RNAs in human fetal adrenal cells. This suggests common regulatory mechanisms for these adjacent genes.

Developmental expression of genes for the stereoidogenic enzymes P450scc (20,22-desmolase), P450c17 (17 alpha-hydroxylase/17,20-lyase), and P450c21 (21-hydroxylase) in the human fetus.

Fetal adrenal steroidogenesis is required for the production of placental estrogen, and fetal testicular steroidogenesis is required for the development of male external genitalia. We studied the ontogeny and tissue specificity of expression of the genes for three steroidogenic enzymes: P450scc (the cholesterol side-chain cleavage enzyme), P450c17 (17 alpha-hydroxylase/17,20-lyase), and P450c21 (21-hydroxylase) in the human fetus. RNA from fetal tissues was probed with homologous human P450scc, P450c17, and P450c21 cDNAs cloned in our laboratory. At 20-21 weeks gestation, P450scc mRNA was most abundant in the adrenal, followed by testis, placenta, and ovary. P450c17 mRNA was also most abundant in the adrenal, followed by testis and ovary, but was undetectable in the placenta. P450c21 mRNA was detected only in the adrenal. None of these mRNAs was detected in kidney, liver, spleen, intestine, or muscle. Twenty-two fetal testis samples (13-25.8 weeks gestation) were studied. P450scc and P450c17 mRNAs were most abundant at 14-16 weeks and diminished to 35 and 19% of their peak values, respectively, by 20-25.8 weeks. Ovarian P450scc and P450c17 mRNAs were present, respectively, in only 6.2% and 1.8% of the maximum amount in the testis and did not vary detectably from 14.9 to 21.5 weeks gestation. The testicular and ovarian steroidogenic enzyme mRNA data correlate well with previously reported changes in gonadal steroidogenesis with gestational age. The presence of P450scc mRNA, but not P450c17 mRNA, in the placenta indicates that the placenta is able to initiate the synthesis of some steroid hormones, but is not able to synthesize estrogen de novo. Since P450c21 was found only in the adrenal, the extraadrenal 21-hydroxylation of progesterone to deoxycorticosterone, a common event in the fetus, is probably mediated by an enzyme(s) other than P450c21.

Developmental and cyclic adenosine 3',5'monophosphate-dependent regulation of inhibin subunit messenger ribonucleic acids in human fetal testes.

Inhibin subunit messenger ribonucleic acids (mRNAs) are expressed during the gonadal development of rodent, ovine, and bovine fetuses. We investigated the expression of inhibin subunit mRNAs in human fetal gonads between 13 and 25 weeks of gestational age. In testes, the alpha-subunit mRNA was highly expressed at the beginning of the second trimester and its expression level slightly decreased thereafter. Also the beta B-subunit mRNA was detected throughout this time period but no significant developmental change could be observed. Northern analysis showed a 1.6-kilobase (kb) transcript for alpha-chain, as well as two bands of about 5.0 and 4.5 kb for the beta B-subunit. A human Leydig cell tumor also expressed the 1.6-kb alpha-subunit. By filter hybridization studies, the beta A-chain mRNA could not be observed in testes and none of the three inhibin subunits were detectable in the ovaries at this developmental stage. However, reverse-transcription polymerase chain reaction analysis revealed the expression of all three inhibin subunit mRNAs in testes. As studied by in situ hybridization, inhibin alpha-subunit hybridization signal was most intense in seminiferous tubules and weaker hybridization was observed in interstitial cells of the fetal testis. In primary cultures of fetal testicular cells, dibutyryl cAMP (0.2 mmol/L) stimulated alpha- and beta B-mRNAs. It augmented alpha- and beta B-mRNA accumulation up to 6- and 2.5-fold, respectively. Thus, we conclude that: 1) during the second trimester of gestation, human fetal testes express all three inhibin subunit mRNAs, although the beta A-chain expression appears to be low; 2) during this developmental stage inhibin subunit mRNAs are not detectable in ovaries; 3) in human fetal testes, the alpha-chain mRNA is localized to both intratubular and interstitial cells; 4) in cultured human testicular cells, inhibin alpha- and beta B-subunit mRNAs are regulated by a cAMP-dependent pathway.

Hormonally regulated inhibin gene expression in human fetal and adult adrenals.

Inhibin subunit expression has recently been shown to occur in rat and sheep adrenals. We now show the presence of inhibin subunit mRNAs in human fetal and adult adrenal tissue specimens and cultured adrenocortical cells. Northern blot analysis revealed that inhibin alpha-subunit gene is as strongly expressed in fetal adrenals as in fetal testes, whereas adult adrenals expressed alpha-subunit mRNA to a lesser extent. beta A-Subunit mRNA was detectable in placenta, and beta B mRNA was found in testes. With reverse transcription-polymerase chain reaction analysis all inhibin subunit mRNAs (alpha, beta A, and beta B) could be found in fetal adrenal samples. In cultured fetal and adult adrenal cells ACTH and dibutyryl cAMP increased inhibin alpha-subunit mRNA 3- to 4-fold. beta A mRNA was spontaneously induced in cultured adrenal cells. 12-O-Tetradecanoyl phorbol-13-acetate, a protein kinase-C regulator, increased beta A mRNA levels 9.6- and 3.3-fold in fetal and adult adrenal cultures, respectively. 12-O-Tetradecanoyl phorbol-13-acetate treatment abolished ACTH-induced alpha-subunit mRNA accumulation in both fetal and adult cultures. Our results show that inhibin genes are expressed in human fetal adrenals and testes during the second trimester of gestation. Adult adrenals also express inhibin genes, although to a lesser extent than fetal adrenals. Both cAMP- and protein kinase-C-dependent pathways regulate inhibin subunit gene expression in adrenocortical cells. These findings suggest that inhibins/activins are produced locally in human adrenals, where they could function as paracrine or autocrine regulators of adrenal growth and steroidogenesis.

Adrenal suppression, evaluated by a low dose adrenocorticotropin test, and growth in asthmatic children treated with inhaled steroids.

The aim of the present study was to evaluate the prevalence of adrenal suppression and growth retardation in children using moderate doses of budesonide or fluticasone propionate. Seventy-five asthmatic children were randomly divided into three treatment groups: 30 to the fluticasone propionate (FP), 30 to the budesonide (BUD), and 15 to the cromone (CROM) group. FP doses were 500 microg/day during the first 2 months and 200 microg/day thereafter. The respective BUD doses were 800 and 400 microg/day. A low dose ACTH (0.5 microg/1.73 m2) test was performed before treatment and 2, 4, and 6 months later. The test was considered abnormal if the stimulated serum cortisol concentration was more than 2 SD lower than the pretreatment mean (<330 nmol/L). The low dose ACTH test was abnormal after both the high and low steroid doses in 23% of the children. At the 4 month measurement there were more abnormal tests in the BUD (n = 9) than in the FP (n = 5) group (P < 0.05). At that time also the stimulated concentration of serum cortisol was lower in the BUD than in the CROM group (P < 0.01), whereas the difference between the FP and CROM groups was not significant. During the study year the mean decrease in height SD score was 0.23 in the children treated with BUD, 0.03 in the children treated with FP, and 0.09 in the children treated with CROM; the difference between the BUD and FP groups was significant (P < 0.05). In conclusion, the low dose ACTH test revealed mild adrenal suppression in a quarter of the children using moderate doses of inhaled steroids. A FP dose of 200 microg/day caused less adrenal and growth suppression than did a BUD dose of 400 microg/day.

Serum dehydroepiandrosterone sulfate concentration as an indicator of adrenocortical suppression in asthmatic children treated with inhaled steroids.

ACTH regulates adrenal androgen production, which may thus be reduced during glucocorticosteroid therapy. Dehydroepiandrosterone sulfate is the most abundant androgen secreted by the adrenals. We wished to evaluate whether serum levels of dehydroepiandrosterone sulfate can be used as an indicator of adrenal suppression during inhaled steroid treatment in children. Sixty school-aged children with newly diagnosed asthma were randomly divided into budesonide (n = 30) and fluticasone propionate (n = 30) groups. Fifteen cromone-treated children served as a control group. The budesonide dose was 800 microg/d during the first 2 months and 400 microg/d thereafter. The respective fluticasone propionate doses were 500 and 200 microg/d. Serum dehydroepiandrosterone sulfate concentrations were measured before and after 2 and 4 months of treatment. In the budesonide group, serum dehydroepiandrosterone sulfate decreased from the baseline by a mean of 21% (95% confidence interval, 13-29%; P < 0.001) after 2 months of high dose treatment and by 16% (95% confidence interval, 8-25%; P < 0.001) after 4 months of treatment. In the fluticasone propionate group, the respective figures were 10% (95% confidence interval, 4-16%; P < 0.01) and 6% (95% confidence interval, 16% decrease-3% increase; P = NS). A low dose ACTH test indicated adrenocortical suppression at 4 months in 14 (23%) steroid-treated children. In these children, dehydroepiandrosterone sulfate decreased by a mean of 21% (95% confidence interval, 14-28%), whereas in those 46 steroid-treated children with normal ACTH test results, dehydroepiandrosterone sulfate decreased by 8% (95% confidence interval, 0-16%; P < 0.05 between these groups). In the control group, dehydroepiandrosterone sulfate levels tended to increase (by a mean of 26%), reflecting the normal physiological change at this age. In conclusion, inhaled steroid treatment suppresses dehydroepiandrosterone sulfate production in a dose-dependent manner. Monitoring of serum dehydroepiandrosterone sulfate concentrations can be used as a practical method to follow adrenocortical function and to detect its suppression during inhaled steroid treatment in children.