Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The molecular pathology of steroid 21-hydroxylase deficiency is attributable to unequal crossover-mediated gene deletion or to large- or small-scale replacement of the functional CYP21B gene sequence by a copy of the analogous CYP21A pseudogene sequence. Because the pathological point mutations originate from the pseudogene which shows only a small number of differences from the functional CYP21B gene sequence, the total number of different pathological point mutations is likely to be small. Mutant P450c21 enzymes carrying specific amino acid substitutions seen in patients with 21-hydroxylase deficiency exhibit activities that correlate with the clinical severity of the disease and with biochemical abnormalities such as 17-hydroxyprogesterone levels after ACTH (corticotropin) stimulation.
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PMID:Molecular pathology of steroid 21-hydroxylase deficiency. 195 56

Congenital adrenal hyperplasia due to 21-hydroxylase deficiency is a common autosomal-recessive disorder. To ascertain carrier status, adrenocorticotropin (ACTH) stimulation tests are often used. To determine the sensitivity of ACTH stimulation to detect heterozygotes and to correlate stimulated 17-hydroxyprogesterone responses with molecular genotype, we compared molecular genetic analysis of the 21-hydroxylase (CYP21) gene with 17-hydroxyprogesterone responses at 30 min in 51 individuals. Molecular genotype analysis and ACTH stimulation tests were performed in healthy volunteers (n = 20) and relatives of patients with congenital adrenal hyperplasia (n = 31). Polymerase chain reaction (PCR) amplification, single-strand conformational polymorphism (SSCP) analysis, allele-specific oligonucleotide hybridization (ASOH) analysis, and restriction fragment length polymorphism (RFLP) analysis were utilized to screen for 14 CYP21 mutations which account for >90% of the mutations associated with 21-hydroxylase deficiency. Molecular genotype analysis classified 28 individuals as heterozygotic carriers and 23 individuals as normal for all mutations tested. As a group, the heterozygotes had significantly greater stimulated 17-hydroxyprogesterone responses at 10 and 30 min (P < 0.0005). However, on an individual basis, 14/28 (50%) genotyped heterozygotic carriers had stimulated 17-hydroxyprogesterone concentrations, 17-hydroxyprogesterone/cortisol ratios, and 17-hydroxyprogesterone incremental elevations indistinguishable from the genotyped normal individuals. Thus, a normal 17-hydroxyprogesterone response to ACTH stimulation testing does not exclude carrier status for 21-hydroxylase deficiency. Molecular genotype analysis is a more reliable method to determine 21-hydroxylase heterozygotes.
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PMID:Identification of heterozygotic carriers of 21-hydroxylase deficiency: sensitivity of ACTH stimulation tests. 954 98

Steroid hormone biosynthesis in the adrenal cortex is controlled by the peptide hormone adrenocorticotropin (ACTH), which acts to increase intracellular cAMP and results in the activation of cAMP-dependent protein kinase A (PKA) and subsequent increase in steroidogenic gene transcription. Protein phosphorylation by PKA activates transcription of genes encoding steroidogenic enzymes; however the precise proteins which are phosphorylated remain to be determined. We have recently shown that phosphoprotein phosphatase (PP) activity is essential for cAMP-dependent transcription of the human CYP17 (hCYP17) gene in H295R adrenocortical cells. The aim of our current studies was to determine if inhibition of PP activity attenuates cAMP-dependent mRNA expression of other steroidogenic genes in H295R cells. Using various inhibitors of serine/threonine and tyrosine PPs, we examined the role of phosphatase activity on cAMP-dependent transcription of steroidogenic genes in the adrenal cortex. CYP11A, CYP11B1/2, CYP21, and adrenodoxin also require PP activity for cAMP-stimulated gene expression. Inhibition of both serine/threonine and tyrosine PP activities suppresses the cAMP-dependent mRNA expression of several steroidogenic genes, suggesting that a dual-specificity PP is essential for conveying ACTH/cAMP-stimulated transcription. We propose that PKA phosphorylates and activates a dual-specificity phosphatase, which mediates steroidogenic gene transcription in response to ACTH/cAMP.
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PMID:cAMP-dependent transcription of steroidogenic genes in the human adrenal cortex requires a dual-specificity phosphatase in addition to protein kinase A. 1220 Feb 37

Polycystic ovary syndrome (PCOS) affects about 4 to 6% of women of reproductive age and accounts for at least 75% of hyperandrogenic patients. PCOS is diagnosed by the presence of oligo-ovulation and hyperandrogenism after the exclusion of related disorders, such as 21-hydroxylase-deficient nonclassic adrenal hyperplasia (NCAH). In turn, NCAH is a homozygous recessive disorder, diagnosed by a corticotropin-stimulated 17-hydroxyprogesterone (17-HP) level greater than10 ng/mL (30.3 nmol/L) and confirmed by genotyping of the CYP21 gene. The prevalence of NCAH is approximately 50 times less than that of PCOS, affecting between 1 and 10% of hyperandrogenic women, depending on ethnicity. However, it is generally difficult to distinguish NCAH from PCOS solely on clinical grounds, as both demonstrate varying degrees of hyperandrogenism and ovulatory dysfunction. Most PCOS patients have insulin resistance, in contrast to those with NCAH. Likewise, polycystic ovaries are observed in up to 40% of NCAH patients. Both disorders have a strong familial component. The only method that allows the separation of NCAH from PCOS patients is the measurement of 17-HP levels. In conclusion, PCOS and NCAH have differences in prevalence and pathophysiology. However, because the disorders have significant clinical and hormonal similarities, the measurement of 17-HP, preferably basally as a screening method, should be incorporated into the evaluation of all hyperandrogenic patients.
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PMID:21-hydroxylase-deficient nonclassic adrenal hyperplasia: the great pretender. 1459 52

Dioxins and polychlorinated biphenyls (PCBs) have been shown to accumulate in the adrenal glands when incorporated into the body. However, the impacts of exposure on adrenal steroidogenesis have not been thoroughly investigated. In this study, we demonstrated that dioxin-like PCB126 altered androgen, cortisol, and aldosterone biosynthesis differentially in human adrenocortical H295R cells. PCB126 diminished basal and cAMP-induced androstenedione production as well as CYP17 mRNA expression in a dose-dependent and time-dependent manner. The CYP17 repression was accompanied with decreases in the encoded 17 alpha-hydroxylase and 17,20-lyase activities, particularly the latter. In contrast, high concentrations of PCB126 stimulated basal cortisol and aldosterone biosynthesis, including induction of CYP21B, CYP11B1, and CYP11B2 mRNA expression and elevation of the conversion of cortisol from 17-OH-progesterone and aldosterone from progesterone. cAMP abolished the positive effect of PCB126 on cortisol synthesis, while it synergistically enhanced PCB126 stimulation on CYP11B2 expression and aldosterone production. It seemed likely that the downregulation of CYP21B caused by the combination of PCB126 and cAMP counteracted the CYP11B1 induction stimulated by the co-treatment. In addition, high concentrations of PCB126 might sensitize the regulation of adrenocorticotropin (ACTH) on the adrenocortical cells by increasing ACTH receptor levels. Because adrenal steroids have profound influences on glucose tolerance, insulin sensitivity, lipid metabolism, obesity, vascular function, and cardiac remodeling, this article also discusses the potential association of the detected adrenocortical alterations with increased diabetic and cardiovascular risk found among highly exposed people.
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PMID:PCB126 induces differential changes in androgen, cortisol, and aldosterone biosynthesis in human adrenocortical H295R cells. 1570 66

The most frequent form of congenital adrenal hyperplasia (CAH) is steroid 21-hydroxylase deficiency, accounting for more than 90% of cases. Affected patients cannot synthesize cortisol efficiently. Thus the adrenal cortex is stimulated by corticotropin (ACTH) and overproduces cortisol precursors. Some precursors are diverted to sex hormone biosynthesis, causing signs of androgen excess including ambiguous genitalia in newborn females and rapid postnatal growth in both sexes. In the most severe "salt wasting" form of CAH (~75% of severe or "classic" cases), concomitant aldosterone deficiency may lead to salt wasting with consequent failure to thrive, hypovolemia, and shock. Newborn screening minimizes delays in diagnosis, especially in males, and reduces morbidity and mortality from adrenal crises. CAH is a recessive disorder caused by mutations in the CYP21 (CYP21A2) gene, most of which arise from recombination between CYP21 and a nearby pseudogene, CYP21P (CYP21A1P). Phenotype is generally correlated with genotype. Classic CAH patients require chronic glucocorticoid treatment at the lowest dose that adequately suppresses adrenal androgens and maintains normal growth and weight gain, and most require mineralocorticoid (fludrocortisone). Transition of care of older patients to adult physicians should be planned in advance as a structured, ongoing process.
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PMID:Congenital adrenal hyperplasia due to 21 hydroxylase deficiency: from birth to adulthood. 2304 77

Maternal exposure to 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) causes a number of toxic effects on development such as growth retardation and sexual immaturity in the offspring. However, the toxic mechanism remains unknown. Our previous studies have revealed that single oral administration of TCDD (1 jg/kg) to pregnant rats at gestational day (GD) 15 attenuates the fetal expression of testicular steroidogenic proteins such as steroidogenic acute-regulatory protein (StAR) and cytochrome P450 (CYP) 17 by targeting the fetal production of pituitary gonadotropins. In addition, we provided evidence that TCDD-produced damage on the fetal pituitary-gonad axis leads to imprint defects in sexual behaviors at adulthood. In this study, we investigated whether TCDD also affects fetal steroidogenesis in the adrenal gland. When pregnant Wistar rats were orally treated with TCDD, the fetal expression of CYP21, CYP11B1 and CYP11B2 mRNAs was either induced or tended to be induced in the male adrenal gland during GD17 and GD19, while the expression of mRNAs coding for StAR, CYP11A1 and 313-hydroxysteroid dehydrogenase was insensitive to TCDD treatment. The above alterations did not seem to be caused through a change in the upstream regulator, because TCDD exhibited little ability to attenuate the expression of adrenocorticotropin, a pituitary hormone stimulating adrenal steroidogenesis, in the male and female fetuses. In contrast to the males, TCDD effect on the adrenal gland was not observed in the female fetuses. These results suggest that maternal exposure to TCDD disrupts fetal steroidogenesis in adrenal as well as gonadal glands in a male specific manner, and the mechanism underlying the effect on adrenal gland is independent of the alteration of pituitary regulator.
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PMID:[The gender-specific effect of maternal exposure to dioxin on fetal steroidogenesis in the adrenal gland]. 2385 93