Defects of steroidogenesis

17 alpha-hydroxylase deficiency: A case report of young Chinese woman with a rare gene mutation

We report a young adult woman with 17 alpha‐hydroxylase deficiency (17α‐OHD) in Shandong province of China. The patient carried compound heterozygous mutations in the CYP17A1 gene: c.985–987 delinsAA (p.Tyr329LysfsX90) and c.1486C > T (p.Arg496Cys). The patient's hypertension and hypokalemia were resolved after taking medications of glucocorticoid, aldactone, and calcium antagonists.

A Novel Heterozygous Mutation of the CYP17A1 Gene in a Child with a Micropenis and Isolated 17,20-Lyase Deficiency

Disorders of sexual development (DSDs) are characterized by a heterogeneous group of congenital conditions associated with atypical development of the sex chromosomes, gonadal or anatomical sex. We report the case of a child with an isolated micropenis, a typical feature of the 46,XY DSD showing low basal testosterone levels and post-stimulation with the hCG test. Molecular analysis using a next-generation sequencing (NGS) panel of 50 genes involved in DSDs was performed, revealing a heterozygous mutation, c.1040G > ANM_000102.4, in the CYP17A1 gene. Sanger sequencing was used to confirm the gene variant detected by NGS; it was also performed to his parents, revealing the presence of the same mutation in the mother, who presented no features of the disease. Then, the serum steroid profile was determined by liquid chromatography coupled to tandem mass spectrometry analysis. Interestingly, this analysis highlighted low levels of testosterone, progesterone, and dehydroepiandrostenedione, as also confirmed by a stimulus test with ACTH. These results suggest that, in some cases, heterozygous mutations in recessive genes involved in adrenal steroidogenesis can also affect the patient’s phenotype.

A rare cause of delayed puberty and primary amenorrhea: 17α-hydroxylase enzyme deficiency

AIM

17α-hydroxylase enzyme deficiency is a rare form of congenital adrenal hyperplasia (CAH) and is caused by mutations in the CYP17A1 gene. The main clinical findings are delayed puberty and primary amenorrhea in girls, and disorders of sex development in boys. It can also cause hypertension and hypokalemia in both genders. In this study, we aimed to present the clinical, laboratory and genetic results of 13 patients from eight different families who were diagnosed with complete 17α-hydroxylase enzyme deficiency.

METHODS

The age, symptoms, anthropometric measurements, blood pressure, Tanner stages, and hormonal and chromosome analysis results at the time of admission were recorded from the medical records of the patients. Whole gene next-generation sequencing of CYP17A1 gene was performed to detect mutations. Multiplex ligation dependent probe amplification (MLPA) method were used to detect deletions in the seven patients who had no point mutation were detected in the CYP17A1 gene.

RESULTS

The average age of the patients at the time of admission was 14.8 (range: 12.9-16.6) years. Also at this time, all patients were in adolescence and were raised as females. The karyotypes of eight patients were 46,XY, and of five patients were 46,XX. Ten patients presented with delayed puberty and primary amenorrhea, one patient with delayed puberty and hypertension, and two patients with hypertension and/or hypokalemia. Hypertension and hypokalemia were detected in nine and seven patients, respectively.

CONCLUSIONS

P450c17 enzyme deficiency should be considered in patients presenting with delayed puberty or primary amenorrhea in the adolescence period and diagnosed with hypergonadotropic hypogonadism, if hypertension and hypokalemia accompany. Early diagnosis prevents the occurrence of important health problems such as hypertension, psychological problems, and gender identity disorders, which affect the majority of these patients.

Monogenic Forms of Hypertension

Essential hypertension is a highly prevalent disease in the general population. Secondary hypertension is characterized by a specific and potentially reversible cause of increased blood pressure levels. Some secondary endocrine forms of hypertension are common (caused by uncontrolled cortisol, aldosterone, or catecholamines production). This article describes rare monogenic forms of hypertension, characterized by electrolyte disorders and suppressed renin-aldosterone axis. They represent simple models for the physiology of renal control of sodium levels and plasma volume, thus reaching a high scientific interest. Furthermore, they could explain some features closer to the essential phenotype of hypertension, suggesting a mechanistically driven personalized treatment.

Steroidogenic effect of Erxian decoction for relieving menopause via the p-Akt/PKB pathway in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Erxian decoction (EXD), an empirical Chinese medicine formula, is effectively used in the clinical treatment of menopause-related symptoms in China. Previous data from our group show that EXD has steroidogenic effect on natural menopausal Sprague-Dawley-rats (SD-rats) as an animal model of menopause. However, the mechanistic studies on steroidogenic effects of EXD are still inadequate. Hence, the mechanisms of steroidogenic effects of EXD were studied in vitro and in vivo in this study.

MATERIALS AND METHODS

Menopause causes a decline of endocrine function and a series of symptoms. In this study, 16-20-month-old female SD rats with a low serum estradiol level were employed. Their endocrine functions after treatment with EXD (4.1g/kg) were assessed by determination of their serum estradiol level. Proteins involved in the steroidogenic pathway including StAR, 17βHSD, 3βHSD, aromatase, and activation of phosphorylated Protein Kinase B (p-Akt/PKB), as well as estradiol receptor proteins (ERα & ERβ) after EXD treatment were analyzed. Kinase inhibition assay was conducted to confirm the mechanism of steroidogenic effects of EXD in vitro. MCF-7 and BT-483 cells were used to investigate whether EXD stimulated breast cancer cell proliferation.

RESULTS

Results revealed a significantly ameliorated serum estradiol level, and a significantly increased expression of ovarian aromatase and PKB in the EXD-treated rats. EXD attenuated 17β-estradiol stimulated proliferation of breast cancer cells.

CONCLUSIONS

The results obtained from immunoblotting and measurements of serum estradiol level of the present investigation revealed that EXD may relieve the menopausal syndrome through an upregulation of ovarian aromatase and p-PKB expression without stimulating the growth of breast cancer cells.

17α‑hydroxylase/17,20‑lyase deficiency in congenital adrenal hyperplasia: A case report

Congenital adrenal hyperplasia (CAH) is a rare autosomal recessive disorder caused by mutations in the cytochrome P450 family 17 subfamily A member 1 (CYP17A1) gene located on chromosome 10q24.3, which leads to a deficiency in 17α-hydroxylase/17,20-lyase. The disorder is characterized by low blood levels of estrogens, androgens and cortisol, which leads to a compensatory increase in adrenocorticotropic hormone levels that stimulate the production of mineralocorticoid precursors. This subsequently leads to hypertension, hypokalemia, primary amenorrhea and sexual infantilism. Over 90 distinct genetic lesions have been identified in patients with this disorder. The prevalence of common mutation of CYP17A1 gene differs among ethnic groups. Treatment of this disorder involves replacement of glucocorticoids and sex steroids. Estrogen alone is prescribed for patients who are biologically male with 17α-hydroxylase deficiencies that identify as female. However, genetically female patients may receive estrogen and progesterone supplementation. In the present study, a 17-year-old female with 17α-hydroxylase/17,20-lyase deficiency that presented with primary amenorrhea and sexual infantilism and no hypertension, was examined. The karyotype of the patient was 46, XX, and genetic analysis revealed the presence of a compound heterozygous mutation in exons 6 and 8, leading to the complete absence of 17α-hydroxylase/17,20-lyase activity. The patient was treated with prednisolone and ethinyl estradiol. In addition, a summary of the recent literature regarding CAH is presented.

Acetaminophen Increases Aldosterone Secretion While Suppressing Cortisol and Androgens: A Possible Link to Increased Risk of Hypertension

BACKGROUND

Acetaminophen (paracetamol) is a widely used analgesic and antipyretic drug. Potential side effects are of public health concern, and liver toxicity from acute overdose is well known. More recently, a regular use of acetaminophen has been associated with an increased risk of hypertension.

METHODS

We investigated effects of acetaminophen on steroidogenesis as a possible mechanism for the hypertensive action by using the human adrenocortical cell line, H295R. Cells were treated with 0.1, 0.5, and 1mM of acetaminophen for 24 hours, and secretion of steroids and gene expression of key steps in the steroidogenesis were investigated.

RESULTS

Progesterone and aldosterone secretion were increased dose dependently, while secretion of 17α-OH-progesterone and cortisol as well as dehydroepiandrosterone and androstenedione was decreased. CYP17α-hydroxylase activity, assessed by the ratio 17α-OH-progesterone/progesterone, and CYP17-lyase activity, assessed by the ratio androstenedione/17α-OH-progesterone, were both dose-dependently decreased by acetaminophen. No effects were revealed on cell viability. Treatment of cells with 0.5mM of acetaminophen did not cause any effects on the expression of 10 genes in the steroidogenic pathways.

CONCLUSIONS

The pattern of steroid secretion caused by acetaminophen can be explained by inhibition of CYP17A1 enzyme activity. A decreased secretion of glucocorticoids and androgens, as demonstrated by acetaminophen, would, in an in vivo situation, induce adrenocorticotropic hormone release via negative feedback in the hypothalamic-pituitary-adrenal axis and result in an upregulation of aldosterone secretion. Our results suggest a novel possible mechanism for acetaminophen-induced hypertension, which needs to be further elucidated in clinical investigations.

Current views on the diagnosis and management of hypokalaemia in children

Hypokalaemia is a common electrolyte disorder in children, caused by decreased potassium intake, increased gastrointestinal and urinary losses or transcellular shift. Patients with severe hypokalaemia may suffer from symptoms such as life-threatening cardiac arrhythmias. The aim of our study was to review the aetiology of hypokalaemia, suggest a diagnostic algorithm and discuss the management of patients with various aetiologies of hypokalaemia.

CONCLUSION

Understanding the pathophysiology of hypokalaemic states, along with a detailed medical history, physical examination and specific laboratory tests are required for proper diagnosis and appropriate treatment.

A case of 17 alpha-hydroxylase deficiency

17α-hydroxylase and 17,20-lyase are enzymes encoded by the CYP17A1 gene and are required for the synthesis of sex steroids and cortisol. In 17α-hydroxylase deficiency, there are low blood levels of estrogens, androgens, and cortisol, and resultant compensatory increases in adrenocorticotrophic hormone that stimulate the production of 11-deoxycorticosterone and corticosterone. In turn, the excessive levels of mineralocorticoids lead to volume expansion and hypertension. Females with 17α-hydroxylase deficiency are characterized by primary amenorrhea and delayed puberty, with accompanying hypertension. Affected males usually have female external genitalia, a blind vagina, and intra-abdominal testes. The treatment of this disorder is centered on glucocorticoid and sex steroid replacement. In patients with 17α-hydroxylase deficiency who are being raised as females, estrogen should be supplemented, while genetically female patients with a uterus should also receive progesterone supplementation. Here, we report a case of a 21-year-old female with 17α-hydroxylase deficiency who had received inadequate treatment for a prolonged period of time. We also include a brief review of the recent literature on this disorder.

DSDs: genetics, underlying pathologies and psychosexual differentiation

Mammalian sex determination is the unique process whereby a single organ, the bipotential gonad, undergoes a developmental switch that promotes its differentiation into either a testis or an ovary. Disruptions of this complex genetic process during human development can manifest as disorders of sex development (DSDs). Sex development can be divided into two distinct processes: sex determination, in which the bipotential gonads form either testes or ovaries, and sex differentiation, in which the fully formed testes or ovaries secrete local and hormonal factors to drive differentiation of internal and external genitals, as well as extragonadal tissues such as the brain. DSDs can arise from a number of genetic lesions, which manifest as a spectrum of gonadal (gonadal dysgenesis to ovotestis) and genital (mild hypospadias or clitoromegaly to ambiguous genitalia) phenotypes. The physical attributes and medical implications associated with DSDs confront families of affected newborns with decisions, such as gender of rearing or genital surgery, and additional concerns, such as uncertainty over the child's psychosexual development and personal wishes later in life. In this Review, we discuss the underlying genetics of human sex determination and focus on emerging data, genetic classification of DSDs and other considerations that surround gender development and identity in individuals with DSDs.

Clinical Chemistry and Other Laboratory Tests on Mouse Plasma or Serum

Besides hematological analyses, many other parameters, including clinical chemistry and endocrinological values, can be determined from mouse blood samples. For most of these tests, plasma or serum samples are used. Data obtained by these investigations provide indications of genotype effects on metabolism and organ functions. Here we describe in detail the considerations that have to be taken into account to get adequate samples for plasma or serum analyses and the recommended sample processing for different investigations. Furthermore, we describe established methods used in the German Mouse Clinic (GMC) to determine clinical chemical parameters; for more in-depth analysis of specific classes of biomarkers, we provide instructions for ELISAs (sandwich and competitive) as well as LC-MS/MS, focusing on markers associated with bone or steroid metabolism in the mouse as working examples. Curr. Protoc. Mouse Biol. 3:69-100 © 2013 by John Wiley & Sons, Inc.

Effect of Hibiscus sabdariffa and its Anthocyanins on Some Reproductive Aspects in Rats

An aqueous extract of Hibiscus sabdariffa L. is a common beverage in many parts of the world. Reports on its effect on reproduction are conflicting, with anecdotal evidence that the plant is an aphrodisiac, while others report that it is estrogenic, and adversely affects spermatogenesis in rats. We have studied the effect of different concentrations of aqueous extracts of H. sabdariffa calyces (10%, 15% and 20%) used as drinking water for 10 consecutive weeks, and its anthocyanins (50, 100, 200 mg/kg for 5 days, orally) on the weight and histology of the testis, and on some biochemical constituents in testicular homogenates, in addition to the plasma concentrations of testosterone, luteinizing hormone and estradiol. The possible presence of an estrogenic effect of the extract and anthocyanins on the uteri of immature female rats was also tested. Neither the H. sabdariffa extract nor the anthocyanins significantly altered either testicular weight and histology, or uterus weight. Plasma concentrations of the three hormones studied, the testicular concentrations of protein, reduced glutathione and total cholesterol, and superoxide dismutase activity were all insignificantly affected by either the extract or the anthocyanins, except for a slight, but statistically significant, decrease in testicular protein concentration caused by the 15% aqueous extract when compared with controls. These results suggest that H. sabdariffa exerts no adverse effect on the male reproductive system. Consumption of H. sabdariffa aqueous extract inhibited the growth of the rats compared with the controls.