- Characterizing the Steroidal Milieu in Amniotic Fluid of Mid-Gestation: A GC-MS Study. [Journal Article]
- JSJ Steroid Biochem Mol Biol 2019 Jun 13; :105412
- Intact steroid hormone biosynthesis is essential for growth and development of the human fetus and embryo. In the present study, gas chromatography-mass spectrometry was employed to characterize the …
Intact steroid hormone biosynthesis is essential for growth and development of the human fetus and embryo. In the present study, gas chromatography-mass spectrometry was employed to characterize the steroidal milieu in amniotic fluid (n = 65; male: female = 35: 30) of mid-gestation (median: 18.8th week, range: 16.0th - 24.6th week) by a comprehensive targeted steroid hormone metabolomics approach. The levels of 52 steroids including pregnenolone and 17-OH-pregnenolone metabolites, dehydroepiandrosterone (DHEA) and its metabolites, progesterone and 17-OH-progesterone metabolites, sex hormones as well as corticosterone and cortisol metabolites were measured. The dominating steroids were the group of pregnenolone and 17-OH-pregnenolone metabolites (mean ± SD: 138.0 ± 59.3 ng/mL), followed by the group of progesterone and 17-OH-progesterone metabolites (107.3 ± 44.3 ng/mL), and thereafter DHEA and its metabolites (97.1 ± 56.5 ng/mL). With respect to sex steroids, only testosterone showed a significantly higher value in male fetuses (p < 0.0001). Of all estrogen metabolites, estriol showed by far the highest concentrations (33.2 ± 26.1 ng/mL). Interestingly, cortisol metabolites were clearly present (59.6 ± 13.6 ng/mL) though fetal de novo synthesis of cortisol is assumed to start from gestational 28th week onwards. Our comprehensive characterization of the steroidal milieu in amniotic fluid of mid-gestation shows presence of all relevant classes of steroid hormones and provides reference data. We conclude that the steroidal milieu in amniotic fluid mirrors the steroidome of the feto-placental unit.
- Flurbiprofen inhibits androgen productions in rat immature Leydig cells. [Journal Article]
- CRChem Res Toxicol 2019 Jun 11
- Flurbiprofen is one of the nonsteroidal anti-inflammatory drugs. Whether flurbiprofen affects androgen biosynthesis in Leydig cells is still unknown. Immature Leydig cells (ILCs) isolated from 35-day…
Flurbiprofen is one of the nonsteroidal anti-inflammatory drugs. Whether flurbiprofen affects androgen biosynthesis in Leydig cells is still unknown. Immature Leydig cells (ILCs) isolated from 35-day-old male Sprague Dawley rats were cultured with 0-100 µM flurbiprofen for 24 h and medium androgen levels and Leydig cell mRNA levels were measured. Immature Leydig cells were also incubated with 100 µM flurbiprofen for 3 h in combination with luteinizing hormone (LH), 8bromo-cAMP, 22R-OH-cholesterol, pregnenolone, progesterone, androstenedione, testosterone, and dihydrotestosterone, respectively, and medium androgen levels were measured. The ROS generation and apoptosis rate were also investigated. The direct effects of flurbiprofen on androgen biosynthetic and metabolizing enzyme activities were measured. Flurbiprofen significantly inhibited basal, LH and 8bromo-cAMP stimulated androgen production at 10 and 100 µM. Further study demonstrated that flurbiprofen competitively inhibited rat and human testis 3β-hydroxysteroid dehydrogenase (HSD3B) activity, with the half maximal inhibitory concentration (IC50) values of 0.95 µM for rat enzyme and 6.31 µM for human enzyme. In addition, flurbiprofen down-regulated the expression of Srd5a1 and Akr1c14 at 1, 10, and 100 µM. Flurbiprofen also down-regulated Lhcgr expression at 100 μM. Flurbiprofen at 10 and 100 μM increased ROS production and apoptosis rate of rat Leydig cells. In conclusion, flurbiprofen directly inhibits HSD3B activity and the expression levels of Srd5a1 and Akr1c14 in rat Leydig cells, thus leading to the reduction of androgen secretion.
- Effects of dexmedetomidine on the steroidogenesis of rat immature Leydig cells. [Journal Article]
- SSteroids 2019 Jun 05
- Dexmedetomidine (DEX), an imidazole compound, is an anesthetic drug used perioperatively. In the current study, we investigated the effects of DEX on androgen production in rat immature Leydig cells …
Dexmedetomidine (DEX), an imidazole compound, is an anesthetic drug used perioperatively. In the current study, we investigated the effects of DEX on androgen production in rat immature Leydig cells in vitro. Leydig cells isolated from pubertal Sprague Dawley rats were treated with various concentrations of DEX (0.015-1.5 µM) for 3 h and medium 5α-androstanediol and testosterone levels and the expression of Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, Hsd17b3, Srd5a1 and Akr1c14 in Leydig cells were determined. At 0.015-1.5 μM, DEX concentration-dependently inhibited androgen secretion and downregulated Cyp17a1 and Srd5a1 mRNA levels. DEX equally blocked the LH- and cAMP-stimulated secretion of androgens. Using the steroid substrates, 22R-hydroxycholesterol (for cytochrome P450 cholesterol side chain cleavage), pregnenolone (for 3β-hydroxysteroid dehydrogenase 1), progesterone (for cytochrome P450 17α-hydroxylase/C17,C20-lyase), androstenedione (for 17β-hydroxysteroid dehydrogenase 3), testosterone (for steroid 5α-reductase 1), and dihydrotestosterone (for 3α-hydroxysteroid dehydrogenase), it was demonstrated that DEX inhibited 22R-hydroxycholesterol, pregnenolone, progesterone, and testosterone-mediated 5α-androstanediol formation at 1.5 μM. Further study demonstrated that DEX also directly inhibited rat testis cholesterol side chain cleavage, 3β-hydroxysteroid dehydrogenation, and 17α-hydroxylation at 1.5 μM. DEX induced ROS production and increased apoptosis rate in immature Leydig cells after 24-h treatment at ≥0.15 μM. In conclusion, DEX directly inhibits the activities of some steroidogenic enzymes and downregulates the expression of Cyp17a1 and Srd5a1, and increases ROS production, thus leading to lower production of androgens in immature Leydig cells.
- A Child with Ambiguous Genitalia: An Atypical Presentation. [Case Reports]
- JCJ Coll Physicians Surg Pak 2019; 29(6):S54-S55
- Lipoid congenital adrenal hyperplasia (LCAH) (OMIM No. 201710) is the most severe type of congenital adrenal hyperplasia (CAH). Its clinical presentation includes lethal disturbance of adrenal and go…
Lipoid congenital adrenal hyperplasia (LCAH) (OMIM No. 201710) is the most severe type of congenital adrenal hyperplasia (CAH). Its clinical presentation includes lethal disturbance of adrenal and gonadal steroid synthesis due to impairment in the conversion of cholesterol to pregnenolone. Infants with this disorder experience salt loss, and glucocorticoid and mineralocorticoid deficiencies. Replacement therapy has enabled long-term survival. Classic LCAH is relatively common in Japan and Korea but extremely rare in Caucasian populations. An XY male 5-year-old child presented at Endocrine Clinic of Armed Forces Institute of Pathology with ambiguous genitalia and hyperpigmentation. He had family history of CAH. His laboratory investigations revealed normal serum cortisol and 17 Hydroxy (17 OH) progesterone levels with high plasma ACTH and renin levels. He had low aldosterone with inadequate response with hCG stimulation test. This is the first case of non-classic LCAH reported in the Pakistani population. Steroidogenic acute regulatory protein (StAR) gene mutations result in LCAH and the condition should be considered in the differential diagnosis of an XY child with primary adrenal insufficiency.
- Multiple adrenocortical steroid response to administration of exogenous adrenocorticotropic hormone to hospitalized foals. [Journal Article]
- JVJ Vet Intern Med 2019 May 20
- CONCLUSIONS: The 17α-OH-progesterone response to administration of ACTH was a good predictor of disease severity and death in hospitalized foals.
- Conformational selection dominates binding of steroids to human cytochrome P450 17A1. [Journal Article]
- JBJ Biol Chem 2019 May 09
- Cytochrome P450 (P450, CYP) enzymes are the major catalysts involved in the oxidation of steroids, as well as many other compounds. Their versatility has been explained in part by flexibility of the …
Cytochrome P450 (P450, CYP) enzymes are the major catalysts involved in the oxidation of steroids, as well as many other compounds. Their versatility has been explained in part by flexibility of the proteins and complexity of binding mechanisms. However, whether these proteins bind their substrates via induced fit or conformational selection is not understood. P450 17A1 has a major role in steroidogenesis, catalyzing the two-step oxidations of progesterone and pregnenolone to androstenedione and dehydroepiandrosterone, respectively, via 17α-hydroxy (OH) intermediates. We examined the interaction of P450 17A1 with its steroid substrates by analyzing progress curves (UV-visible spectroscopy), revealing that the rates of binding of any of these substrates decreased with increasing substrate concentration, a hallmark of conformational selection. Further, when the concentration of 17α-OH pregnenolone was held constant and the P450 concentration increased, the binding rate increased, and such opposite patterns are also diagnostic of conformational selection. Kinetic simulation modeling was also more consistent with conformational selection than with an induced-fit mechanism. Cytochrome b 5 partially enhances P450 17A1 lyase activity by altering the P450 17A1 conformation but did not measurably alter the binding of 17α-OH pregnenolone or 17α-OH progesterone, as judged by the apparent K d and binding kinetics. The P450 17A1 inhibitor abiraterone also bound to P450 17A1 in a multi-step manner, and modeling indicated that the selective inhibition of the two P450 17A1 steps by the drug orteronel can be rationalized only by a multiple-conformation model. In conclusion, P450 17A1 binds its steroid substrates via conformational selection.
- Deficient pregnenolone synthesis associated with congenital adrenal hyperplasia and organelle dysfunction. [Journal Article]
- EDEndocrinol Diabetes Metab Case Rep 2019 May 03; 2019
- Steroid hormones are essential for the survival of all mammals. In adrenal glands and gonads, cytochrome P450 side chain cleavage enzyme (SCC or CYP11A1), catalyzes conversion of cholesterol to pregn…
Steroid hormones are essential for the survival of all mammals. In adrenal glands and gonads, cytochrome P450 side chain cleavage enzyme (SCC or CYP11A1), catalyzes conversion of cholesterol to pregnenolone. We studied a patient with ambiguous genitalia by the absence of Müllerian ducts and the presence of an incompletely formed vagina, who had extremely high adrenocorticotropic hormone (ACTH) and reduced pregnenolone levels with enlarged adrenal glands. The testes revealed seminiferous tubules, stroma, rete testis with interstitial fibrosis and reduced number of germ cells. Electron microscopy showed that the patient's testicular mitochondrial size was small with little SCC expression within the mitochondria. The mitochondria were not close to the mitochondria-associated ER membrane (MAM), and cells were filled with the microfilaments. Our result revealed that absence of pregnenolone is associated with organelle stress, leading to altered protein organization that likely created steric hindrance in testicular cells. Learning points: Testes revealed seminiferous tubules, stroma, rete testis with interstitial fibrosis and reduced number of germ cells; Testicular mitochondrial size was small with little SCC expression within the mitochondria; Absence of pregnenolone is associated with organelle stress.
- Transcriptomic profiling identifies novel mechanisms of transcriptional regulation of the cytochrome P450 (Cyp)3a11 gene. [Journal Article]
- SRSci Rep 2019 Apr 30; 9(1):6663
- Cytochrome P450 (CYP)3A is the most abundant CYP enzyme in the human liver, and a functional impairment of this enzyme leads to unanticipated adverse reactions and therapeutic failures; these reactio…
Cytochrome P450 (CYP)3A is the most abundant CYP enzyme in the human liver, and a functional impairment of this enzyme leads to unanticipated adverse reactions and therapeutic failures; these reactions result in the early termination of drug development or the withdrawal of drugs from the market. The transcriptional regulation mechanism of the Cyp3a gene is not fully understood and requires a thorough investigation. We mapped the transcriptome of the Cyp3a gene in a mouse model. The Cyp3a gene was induced using the mPXR activator pregnenolone-16alpha-carbonitrile (PCN) and was subsequently downregulated using lipopolysaccharide (LPS). Our objective was to identify the transcription factors (TFs), epigenetic modulators and molecular pathways that are enriched or repressed by PCN and LPS based on a gene set enrichment analysis. Our analysis shows that 113 genes were significantly upregulated (by at least 1.5-fold) with PCN treatment, and that 834 genes were significantly downregulated (by at least 1.5-fold) with LPS treatment. Additionally, the targets of the 536 transcription factors were enriched by a combined treatment of PCN and LPS, and among these, 285 were found to have binding sites on Cyp3a11. Moreover, the repressed targets of the epigenetic markers HDAC1, HDAC3 and EZH2 were further suppressed by LPS treatment and were enhanced by PCN treatment. By identifying and contrasting the transcriptional regulators that are altered by PCN and LPS, our study provides novel insights into the transcriptional regulation of CYP3A in the liver.
- Neurosteroid Actions in Memory and Neurologic/Neuropsychiatric Disorders. [Review]
- FEFront Endocrinol (Lausanne) 2019; 10:169
- Memory dysfunction is a symptomatic feature of many neurologic and neuropsychiatric disorders; however, the basic underlying mechanisms of memory and altered states of circuitry function associated w…
Memory dysfunction is a symptomatic feature of many neurologic and neuropsychiatric disorders; however, the basic underlying mechanisms of memory and altered states of circuitry function associated with disorders of memory remain a vast unexplored territory. The initial discovery of endogenous neurosteroids triggered a quest to elucidate their role as neuromodulators in normal and diseased brain function. In this review, based on the perspective of our own research, the advances leading to the discovery of positive and negative neurosteroid allosteric modulators of GABA type-A (GABAA), NMDA, and non-NMDA type glutamate receptors are brought together in a historical and conceptual framework. We extend the analysis toward a state-of-the art view of how neurosteroid modulation of neural circuitry function may affect memory and memory deficits. By aggregating the results from multiple laboratories using both animal models for disease and human clinical research on neuropsychiatric and age-related neurodegenerative disorders, elements of a circuitry level view begins to emerge. Lastly, the effects of both endogenously active and exogenously administered neurosteroids on neural networks across the life span of women and men point to a possible underlying pharmacological connectome by which these neuromodulators might act to modulate memory across diverse altered states of mind.
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- A bypass mechanism of abiraterone-resistant prostate cancer: Accumulating CYP17A1 substrates activate androgen receptor signaling. [Journal Article]
- PProstate 2019; 79(9):937-948
- CONCLUSIONS: Activation of the AR by clinically relevant levels of Preg and Prog accumulating in abiraterone-treated patients may act as a driver for CRPC. These data provide a scientific rationale for combining CYP17A1 inhibitors with antiandrogens, particularly in patients with overexpressed or mutated-AR.