STAR splicing mutations cause the severe phenotype of lipoid congenital adrenal hyperplasia: insights from a novel splice mutation and review of reported cases

OBJECTIVE The steroidogenic acute regulatory protein (StAR) transports cholesterol to the mitochondria for steroidogenesis. Loss of StAR function causes lipoid congenital adrenal hyperplasia (LCAH) which is characterized by impaired synthesis of adrenal and gonadal steroids causing adrenal insufficiency, 46,XY disorder of sex development (DSD) and failure of pubertal development. Partial loss of StAR activity may cause adrenal insufficiency only. PATIENT A newborn girl was admitted for mild dehydration, hyponatremia, hyperkalemia and hypoglycaemia and had normal external female genitalia without hyperpigmentation. Plasma cortisol, 17OH-progesterone, DHEA-S, androstendione and aldosterone were low, while ACTH and plasma renin activity were elevated, consistent with the diagnosis of primary adrenal insufficiency. Imaging showed normal adrenals, and cytogenetics revealed a 46,XX karyotype. She was treated with fluids, hydrocortisone and fludrocortisone. DESIGN, METHODS AND RESULTS Genetic studies revealed a novel homozygous STAR mutation in the 3' acceptor splice site of intron 4, c.466-1G>A (IVS4-1G>A). To test whether this mutation would affect splicing, we performed a minigene experiment with a plasmid construct containing wild-type or mutant StAR gDNA of exons-introns 4-6 in COS-1 cells. The splicing was assessed on total RNA using RT-PCR for STAR cDNAs. The mutant STAR minigene skipped exon 5 completely and changed the reading frame. Thus, it is predicted to produce an aberrant and shorter protein (p.V156GfsX19). Computational analysis revealed that this mutant protein lacks wild-type exons 5-7 which are essential for StAR-cholesterol interaction. CONCLUSIONS STAR c.466-1A skips exon 5 and causes a dramatic change in the C-terminal sequence of the protein, which is essential for StAR-cholesterol interaction. This splicing mutation is a loss-of-function mutation explaining the severe phenotype of our patient. Thus far, all reported splicing mutations of STAR cause a severe impairment of protein function and phenotype.

P450 oxidoreductase deficiency: a new disorder of steroidogenesis affecting all microsomal P450 enzymes

Combined partial deficiency of 17alpha-hydroxylase and 21-hydroxylase activities was first described in 1985; however the genes for P450c17 and P450c21 in these patients lack mutations. In 1986 we postulated that this disorder might be due to mutations in P450 oxidoreductase (POR), the flavoprotein that donates electron to these and all other microsomal P450 enzymes, but this hypothesis was not tested until the POR gene sequence became available through the genome database. We found five POR missense mutations in our first four patients. In vitro assays of the activities of these mutations showed that the standard assay of POR activity, reduction of cytochrome c, correlated poorly with the patients' phenotypes, but that assays of POR-supported 17alpha-hydroxylase and 17,20 lyase activities correlated well. POR deficiency is a new disorder of adrenal and gonadal steroidogenesis that affects all microsomal cytochrome P450 enzymes, hence may have important implications for genetic differences in drug metabolism.

Early follicular testosterone level predicts preference for masculinity in male faces — But not for women taking hormonal contraception

It has been shown that women’s preference for masculinity in male faces changes across the menstrual cycle. Preference for masculinity is stronger when conception probability is high than when it is low. These findings have been linked to cyclic fluctuations of hormone levels. The purpose of the present study is to further investigate the link between gonadal steroids (i.e. testosterone, estradiol, and progesterone) and masculinity preference in women, while holding the cycle phase constant. Sixty-two female participants were tested in their early follicular cycle phase, when conception probability is low. Participants were shown face pairs and where asked to choose the more attractive face. Face pairs consisted of a masculinized and feminized version of the same face. For naturally cycling women we found a positive relationship between saliva testosterone levels and masculinity preference, but there was no link between any hormones and masculinity preference for women taking hormonal contraception. We conclude that in naturally cycling women early follicular testosterone levels are associated with masculinity preference. However, these hormonal links were not found for women with artificially modified hormonal levels, that is, for women taking hormonal contraception.

A novel mutation L260P of the steroidogenic acute regulatory protein gene in three unrelated patients of Swiss ancestry with congenital lipoid adrenal hyperplasia.

CONTEXT Lipoid congenital adrenal hyperplasia (CAH) is the most severe form of CAH leading to impaired production of all adrenal and gonadal steroids. Mutations in the gene encoding steroidogenic acute regulatory protein (StAR) cause lipoid CAH. OBJECTIVE We investigated three unrelated patients of Swiss ancestry who all carried novel mutations in the StAR gene. All three subjects were phenotypic females with absent Müllerian derivatives, 46,XY karyotype, and presented with adrenal failure. METHODS AND RESULTS StAR gene analysis showed that one patient was homozygous and the other two were heterozygous for the novel missense mutation L260P. Of the heterozygote patients, one carried the novel missense mutation L157P and one had a novel frameshift mutation (629-630delCT) on the second allele. The functional ability of all three StAR mutations to promote pregnenolone production was severely attenuated in COS-1 cells transfected with the cholesterol side-chain cleavage system and mutant vs. wild-type StAR expression vectors. CONCLUSIONS These cases highlight the importance of StAR-dependent steroidogenesis during fetal development and early infancy; expand the geographic distribution of this condition; and finally establish a new, prevalent StAR mutation (L260P) for the Swiss population.

Aromatase deficiency caused by a novel P450arom gene mutation: impact of absent estrogen production on serum gonadotropin concentration in a boy.

We identified a new point mutation in the CYP19 gene responsible for aromatase (P450arom) deficiency in a 46,XY male infant with unremarkable clinical findings at birth. This boy is homozygote for a 1-bp (C) deletion in exon 5 of the aromatase gene causing a frame-shift mutation. The frame-shift results in a prematurely terminated protein that is inactive due to the absence of the functional regions of the enzyme. Aromatase deficiency was suspected prenatally because of the severe virilization of the mother during the early pregnancy, and the diagnosis was confirmed shortly after birth. Four weeks after birth, the baby boy showed extremely low levels of serum estrogens, but had a normal level of serum free testosterone; in comparison with the high serum concentration of androstenedione at birth, a striking decrease occurred by 4 weeks postnatally. We previously reported elevated basal and stimulated FSH levels in a female infant with aromatase deficiency in the first year of life. In contrast, in the male infant, basal FSH and peak FSH levels after standard GnRH stimulation tests were normal. This finding suggests that the contribution of estrogen to the hypothalamic-pituitary gonadotropin-gonadal feedback mechanism is different in boys and girls during infancy and early childhood. In normal girls, serum estradiol concentrations strongly correlate with circulating inhibin levels, and thus, low inhibin levels may contribute to the striking elevation of FSH in young girls with aromatase deficiency. In contrast, estradiol levels are physiologically about a 7-fold lower in boys than in girls, and serum inhibin levels remain elevated even though levels of FSH, LH, and testosterone are decreased.

Influence of physical activity and acute exercise on cognitive performance and saliva testosterone in preadolescent school children

We investigated whether the chronic physical activity participation had an impact on the acute effects of a short bout of 12 min of intensive physical activity on cognitive performance and testosterone concentration in primary school students (n = 42, mean age = 9.69, SD = .44; experimental group (EG), n = 27; control group (CG), n = 15). Furthermore, we looked for associations between testosterone concentration and cognitive performance. After the intervention, participants of the EG showed better cognitive performances as compared to the CG. We further observed a significant group (EG, CG) test (pre, post) activity level (high, low) interaction. Post hoc pairwise comparisons revealed that after acute physical activity the testosterone concentration was diminished only in habitually low active children. The results indicate that intensive physical activity only attenuates the reactivity of the hypothalamic-pituitary-gonadal axis in habitually low active preadolescents, but had a beneficial effect on cognitive performance for all participants independent of their physical activity level and testosterone.

Immune modulation alters brain opioid activities: Evidence for a role of muramyl dipeptide in the process of neuroimmunemodulation

During the last twenty years a scientific basis for the anecdotal reports of an interaction between the brain and the immune system has established neuroimmunemodulation as a new field of study in the biomedical sciences. A means for the brain to exert a regulatory influence upon various lymphoid reactions has been well established by many investigators world wide. This dissertation was geared to test the central hypothesis that the immune system, in turn, produces signals which affect CNS functions. Specifically, it is shown through several different experiments, behavioral and electrophysiologic, that the immune modifiers interferon-alpha, gamma irradiation, cyclosporine-A and muramyl-dipeptide modify brain opioid related activities. Each agent attenuates naloxone-precipitated morphine withdrawal following either systemic or intracranial injection. Each agent also has effects upon either the acute antinociceptive or hypothermic activities of morphine. Finally, each agent modifies baseline evoked electrical activity of several brain areas of awake freely-behaving rats. Later studies demonstrate that muramyl-dipeptide modifies the unit firing rate of single neurons in the brain following either systemic or localized administration within the brain. These results suggest that the immune system produces signals which affect brain activity; and thus, support the contention of a bi-directional interaction between the brain and the immune system. ^

c-{\it mos\/} RNA expression in somatic cells and its physiological significance in cell cycle progression

The c-mos proto-oncogene, which is expressed at relatively high levels in male and female germ cells, plays a key role in oocyte meiotic maturation. The c-mos gene product in oocytes (p39$\sp{\rm c-mos}$) is necessary and sufficient to initiate meiosis. p39$\sp{\rm c-mos}$ is also an essential component of the cytostatic factor, which is responsible for arresting vertebrate oocytes at the second meiotic metaphase by stabilizing the maturation promoting factor (MPF). MPF is a universal regulator of both meiosis and mitosis. Much less is understood about c-mos expression and function in somatic cells. In addition to gonadal tissues, c-Mos has been detected in some somatic tissues and non-germ cell lines including NIH 3T3 cells as a protein termed p43$\sp{\rm c-mos}$. Since c-mos RNA transcripts were not previously detected in this cell line by Northern blot or S1 protection analyses, a search was made for c-mos RNA in NIH 3T3 cells. c-mos transcripts were detected using the highly sensitive RNA-PCR method and RNase protection assays. Furthermore, cell cycle analyses indicated that expression of c-mos RNA is tightly controlled in a cell cycle dependent manner with highest levels of transcripts (approximately 5 copies/cell) during the G2 phase.^ In order to determine the physiological significance of c-mos RNA expression in somatic cells, antisense mos was placed under the control of an inducible promoter and introduced into either NIH 3T3 cells or C2 cells. It was found that a basal level of expression of antisense mos resulted in interference with mitotic progression and growth arrest. Several nuclear abnormalities were observed, especially the appearance of binucleated and multinucleated cells as well as the extrusion of microvesicles containing cellular material. These results indicate that antisense mos expression results in a block in cytokinesis. In summary, these results establish that c-mos expression is not restricted to germ cells, but instead indicate that c-mos RNA expression occurs during the G2 stage of the cell cycle. Furthermore, these studies demonstrate that the c-mos proto-oncogene plays an important role in cell cycle progression. As in meiosis, c-mos may have a similar but not identical function in regulating cell cycle events in somatic cells, particularly in controlling mitotic progression via activation/stabilization of MPF. ^

IMMUNOGLOBULINS IN PERIODONTAL DISEASE

Periodontal disease is the major cause of tooth loss in man. The initial histological picture of the inflamed gingiva is characteristic of local inflammatory reaction involving polymorphonuclear leukocytes, vasculitis and localized tissue loss. Subsequent clinical stages of periodontal disease (mild gingivitis) show histological evidence of the involvement of the immune response with initial accumulation of macrophages, and lymphocytes devoid of surface staining immunoglobulins (presumably T cells). As the disease progresses, a predominance of surface and cytoplasmic staining lymphocytes and plasma cells are seen (severe gingivitis and periodontitis). Whether the occurrence of the immunoglobulin positive lymphocytes and the concurrent loss of collagen and resorption of alveolar bone seen in periodontitis is indicative of a direct cause and effect relationship has been a controversy.^ The majority of investigations in the periodontal field have involved the use of peripheral blood lymphocytes or serum. Blastogenic responses of peripheral blood lymphocytes and serum antibody titers from periodontal patients to a variety of oral bacteria have not shown any correlation between response and the severity of disease. The need to study the local immune response in inflamed gingiva is apparent. Since there are no baseline studies on the functional capabilities of the lymphoid cells present in gingiva from periodontitis patients, an in depth study involving the role of the immunoglobulin positive lymphocytes was investigated.^ Inflamed gingiva from four clinically defined periodontal disease states (mild gingivitis, severe gingivitis, periodontitis and severe periodontitis) were placed in gingival organ cultures. Class specific immunoglobulins were quantitated in gingival organ culture supernatants using an indirect sandwich technique. A significant difference in mean levels of IgA and IgG was seen between mild gingivitis and periodontitis (P < .00l, P = .001), as well as in IgG levels between periodontitis and severe periodontitis (P = .001). The predominance of IgG in gingival organ culture supernatants and the statistically significant findings that the overall mean levels of IgG between mild gingivitis and periodontitis (P = .014) and between severe periodontitis and periodontitis (P = .001) suggested a possible indicator of periodontal disease. The presence of IgG in gingival organ culture supernatants was shown to be a product of actively secreting plasma cells. The incorporation of radiolabelled amino acids into IgG was noted over a seven-day period with a peak response at day 4-5. The inhibition of IgG synthesis by cyclohexamide confirmed the contention that IgG was a product of de novo synthesis and not serum derived.^ The specificity of immunoglobulins derived from gingival organ cultures were studied using a whole bacterial agglutination test. Oral bacteria frequently cultured from periodontal patients were assessed for their ability to be agglutinated by gingival organ culture supernatants. A positive correlation of antibody titer and severity of disease was seen with five strains of Actinomyces viscosus, two of Actinomyces naeslundii and one Actinomyces israelii. The agglutination of bacteria was shown to be due to the specific interaction of immunoglobulin and cell-wall antigen. ^

The Trade Versus Culture Discourse: Tracing its Evolution in Global Law

The intensified flows of goods, services, peoples and ideas across borders intrinsic to globalization have had numerous and multi-faceted effects. Those affecting culture have been perhaps the most controversial, as it is more often than not difficult to identify the spill-overs across economic and non-economic areas and across borders, as it is equally hard to qualify the effects of these spill-overs as positive or negative. The debate also tends to be politically and even emotionally charged, which has so far not proven advantageous to establishing a genuine dialogue, nor to finding solutions. This contention and the divergent interests of major players in the international community have been reflected in the institutions and rules of global law. It is the objective of this chapter to explore this institutional architecture, in particular its main (and opposing) constituent fora of the World Trade Organization (WTO) and the United Nations Educational Social and Cultural Organization (UNESCO). The chapter traces the evolution of these institutions and their interaction over time, as well as the underlying objectives, demands and strategies of the key proponents in the trade versus culture discourse, which ultimately shaped the existent law and policy. The chapter concludes with an appraisal of the present state of affairs situating the discussion into the contemporary global governance landscape.

Phenotype of capillaries in skeletal muscle of nNOS-knockout mice

Because neuronal nitric oxide synthase (nNOS) has a well-known impact on arteriolar blood flow in skeletal muscle, we compared the ultrastructure and the hemodynamics of/in the ensuing capillaries in the extensor digitorum longus (EDL) muscle of male nNOS-knockout (KO) mice and wild-type (WT) littermates. The capillary-to-fiber (C/F) ratio (-9.1%) was lower (P ≤ 0.05) in the nNOS-KO mice than in the WT mice, whereas the mean cross-sectional fiber area (-7.8%) and the capillary density (-3.1%) varied only nonsignificantly (P > 0.05). Morphometrical estimation of the area occupied by the capillaries as well as the volume and surface densities of the subcellular compartments differed nonsignificantly (P > 0.05) between the two strains. Intravital microscopy revealed neither the capillary diameter (+3% in nNOS-KO mice vs. WT mice) nor the mean velocity of red blood cells in EDL muscle (+25% in nNOS-KO mice vs. WT mice) to significantly vary (P > 0.05) between the two strains. The calculated shear stress in the capillaries was likewise nonsignificantly different (3.8 ± 2.2 dyn/cm² in nNOS-KO mice and 2.1 ± 2.2 dyn/cm² in WT mice; P > 0.05). The mRNA levels of vascular endothelial growth factor (VEGF)-A were lower in the EDL muscle of nNOS-KO mice than in the WT littermates (-37%; P ≤ 0.05), whereas mRNA levels of VEGF receptor-2 (VEGFR-2) (-11%), hypoxia inducible factor-1α (+9%), fibroblast growth factor-2 (-14%), and thrombospondin-1 (-10%) differed nonsignificantly (P > 0.05). Our findings support the contention that VEGF-A mRNA expression and C/F-ratio but not the ultrastructure or the hemodynamics of/in capillaries in skeletal muscle at basal conditions depend on the expression of nNOS.

Buckling Rate and Overhang Development at a Calving Face

Using the finite-element we have modeled the stress field near the calving face of an idealized tidewater glacier under a variety of assumptions about submarine calving-face height, subaerial calving-face height, and ice rheology These simulations all suggest that a speed maximum should be present at the calving face near the waterline. In experiments without crevassing, the decrease in horizontal velocity above this maximum culminates in a zone of longitudinal compression at the surface somewhat Up-glacier from the face. This zone of compression appears to be a consequence of the non-linear rheology of ice. It disappears when a linear rheology is assumed. Explorations of the near-surface stress field indicate that when pervasive crevassing of the surface ice is accounted for in the simulations (by rheological softening), the zone of compressive strain rates does not develop. Variations in the pattern of horizontal velocity with glacier thickness support the contention that calving rates should increase with water depth at the calving face. In addition, the height of the subaerial calving face may have an importance that is not visible ill Current field data owing to the lack of variation in height of such faces in nature. Glaciers with lower calving faces may not have sufficient tensile stress to calve actively, while tensile stresses in simulated higher faces are sufficiently high that such faces will be unlikely to build in nature.

Environmental Effects and Aquatic Organisms: Investigations of Molecular Mechanisms of Carcinogenesis

Cancers of the reproductive system are among the leading causes of mortality in women in the United States. While both genetic and environmental factors have been implicated in their etiology, the extent of the contribution of environmental factors to human diseases remains controversial. To better address the role of environmental exposures in cancer etiology, there has been an increasing focus on the development of nontraditional, environmentally relevant models. Our research involves the development of one such model, Gonadal tumors have been described in the softshell clam (Mya arenaria) in Maine and the hardshell clam (Mercenaria spp.) from Florida. Prevalence of these tumors is as high as 40% in some populations in eastern Maine and 60% in Some areas along the Indian River in Florida. The average tumor prevalence in Maine and Florida is approximately 20 and 11%, respectively. An association has been suggested between the use of herbicides and the incidence of gonadal tumors in the softshell clam in Maine. The role of environmental exposures in the development of the tumors in Mercenaria in Florida is unknown, however, there is evidence that genetic factors may contribute to its etiology. Epidemiologic studies of human populations in these same areas show a higher than average mortality rate due to cancers of the reproductive system in women, including both ovarian and breast career. The relationship, if any, among these observations is unknown, Our studies on the molecular basis of this disease in clams may provide additional information on environmental exposures and their possible link to cancer in clams and other organisms, including humans.

Emdogain-regulated gene expression in palatal fibroblasts requires TGF-βRI kinase signaling.

Genome-wide microarrays have suggested that Emdogain regulates TGF-β target genes in gingival and palatal fibroblasts. However, definitive support for this contention and the extent to which TGF-β signaling contributes to the effects of Emdogain has remained elusive. We therefore studied the role of the TGF-β receptor I (TGF-βRI) kinase to mediate the effect of Emdogain on palatal fibroblasts. Palatal fibroblasts were exposed to Emdogain with and without the inhibitor for TGF-βRI kinase, SB431542. Emdogain caused 39 coding genes to be differentially expressed in palatal fibroblasts by microarray analysis (p<0.05; >10-fold). Importantly, in the presence of the TGF-βRI kinase inhibitor SB431542, Emdogain failed to cause any significant changes in gene expression. Consistent with this mechanism, three independent TGF-βRI kinase inhibitors and a TGF-β neutralizing antibody abrogated the increased expression of IL-11, a selected Emdogain target gene. The MAPK inhibitors SB203580 and U0126 lowered the impact of Emdogain on IL-11 expression. The data support that TGF-βRI kinase activity is necessary to mediate the effects of Emdogain on gene expression in vitro.

Steroidogenesis of the testis - new genes and pathways

Defects of androgen biosynthesis cause 46,XY disorder of sexual development (DSD). All steroids are produced from cholesterol and the early steps of steroidogenesis are common to mineralocorticoid, glucocorticoid and sex steroid production. Genetic mutations in enzymes and proteins supporting the early biosynthesis pathways cause adrenal insufficiency (AI), DSD and gonadal insufficiency. The classic androgen biosynthesis defects with AI are lipoid CAH, CYP11A1 and HSD3B2 deficiencies. Deficiency of CYP17A1 rarely causes AI, and HSD17B3 or SRD5A2 deficiencies only cause 46,XY DSD and gonadal insufficiency. All androgen biosynthesis depends on 17,20 lyase activity of CYP17A1 which is supported by P450 oxidoreductase (POR) and cytochrome b5 (CYB5). Therefore 46,XY DSD with apparent 17,20 lyase deficiency may be due to mutations in CYP17A1, POR or CYB5. Illustrated by patients harboring mutations in SRD5A2, normal development of the male external genitalia depends largely on dihydrotestosterone (DHT) which is converted from circulating testicular testosterone (T) through SRD5A2 in the genital skin. In the classic androgen biosynthetic pathway, T is produced from DHEA and androstenedione/-diol in the testis. However, recently found mutations in AKR1C2/4 genes in undervirilized 46,XY individuals have established a role for a novel, alternative, backdoor pathway for fetal testicular DHT synthesis. In this pathway, which has been first elucidated for the tammar wallaby pouch young, 17-hydroxyprogesterone is converted directly to DHT by 5α-3α reductive steps without going through the androgens of the classic pathway. Enzymes AKR1C2/4 catalyse the critical 3αHSD reductive reaction which feeds 17OH-DHP into the backdoor pathway. In conclusion, androgen production in the fetal testis seems to utilize two pathways but their exact interplay remains to be elucidated.