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Pregnenolone

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https://www.readbyqxmd.com/read/29455953/the-comprehensive-characterization-of-adrenocortical-steroidogenesis-using-two-dimensional-ultra-performance-liquid-chromatography-electrospray-ionization-tandem-mass-spectrometry
#1
Gellért Karvaly, Krisztián Kovács, Katalin Mészáros, Ibolya Kocsis, Attila Patócs, Barna Vásárhelyi
The perturbation of the homeostasis of adrenocortical steroids plays a fundamental role in several pathological conditions. Currently, only a few of the substances involved in steroidogenesis are routinely analysed in clinical laboratories for the diagnosis of these conditions. Recently, interest has grown over the development of clinical assays of endogenous steroids using liquid chromatography-tandem mass spectrometry (LC-MS/MS). However, no approaches have assessed the adrenocortical steroidogenesis comprehensively...
February 3, 2018: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/29451725/selective-sp3-c-h-aerobic-oxidation-enabled-by-deca-tungstate-photocatalysis-in-flow
#2
Gabriele Laudadio, Sebastian Govaerts, Ying Wang, Davide Ravelli, Hannes Koolman, Maurizio Fagnoni, Stevan Djuric, Timothy Noel
A mild and selective sp3 C-H aerobic oxidation enabled by deca-tungstate photocatalysis has been developed. The reaction can be significantly improved in a microflow reactor enabling the safe use of oxygen and the enhanced irradiation of the reaction mixture. Our method allows for the oxidation of both activated and unactivated C-H bonds (30 examples). The ability to selectively oxidize natural scaffolds, such as (-)-ambroxide, pregnenolone acetate, (+)-sclareolide and artemisinin exemplifies the utility of this new method...
February 16, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29447845/probing-gaba-a-receptors-with-inhibitory-neurosteroids
#3
REVIEW
Sandra Seljeset, Damian P Bright, Philip Thomas, Trevor G Smart
γ-aminobutyric acid type A receptors (GABA A Rs) are important components of the central nervous system and they are functionally tasked with controlling neuronal excitability. These receptors are subject to post-translational modification and also to modulation by endogenous regulators, such as the neurosteroids. These modulators can either potentiate or inhibit GABA A R function. Whilst the former class of neurosteroids are considered to bind to and act from the transmembrane domain of the receptor, the domains that are important for the inhibitory neurosteroids remain less clear...
February 12, 2018: Neuropharmacology
https://www.readbyqxmd.com/read/29433072/pregnenolone-progesterone-allopregnanolone-pathway-as-a-potential-therapeutic-target-in-first-episode-antipsychotic-na%C3%A3-ve-patients-with-schizophrenia
#4
HuaLin Cai, Xiang Zhou, George G Dougherty, Ravinder D Reddy, Gretchen L Haas, Debra M Montrose, Matcheri Keshavan, Jeffrey K Yao
Neurosteroids are both endogenous and exogenous steroids that rapidly alter neuronal excitability through interactions with ligand-gated ion channels and other cell surface receptors. They are originated from cholesterol and have important implications for schizophrenia (SZ) pathophysiology and treatment strategies. Specifically, pregnenolone (PREG), progesterone (PROG) and allopregnanolone (ALLO) exhibit similar psychotropic properties. Using enzyme immunoassay, we compared the neurosteroids in PREG downstream pathways in plasma between healthy controls (HC, n = 43) and first-episode antipsychotic-naïve patients with SZ (FEAN-SZ, n = 53) before antipsychotic drug (APD) treatment...
February 7, 2018: Psychoneuroendocrinology
https://www.readbyqxmd.com/read/29429410/the-human-fetal-adrenal-produces-cortisol-but-no-detectable-aldosterone-throughout-the-second-trimester
#5
Zoe C Johnston, Michelle Bellingham, Panagiotis Filis, Ugo Soffientini, Denise Hough, Siladitya Bhattacharya, Marc Simard, Geoffrey L Hammond, Peter King, Peter J O'Shaughnessy, Paul A Fowler
BACKGROUND: Human fetal adrenal glands are highly active and, with the placenta, regulate circulating progesterone, estrogen and corticosteroids in the fetus. At birth the adrenals are essential for neonate salt retention through secretion of aldosterone, while adequate glucocorticoids are required to prevent adrenal insufficiency. The objective of this study was to carry out the first comprehensive analysis of adrenal steroid levels and steroidogenic enzyme expression in normal second trimester human fetuses...
February 12, 2018: BMC Medicine
https://www.readbyqxmd.com/read/29425150/aethiopinolones-a-e-new-pregnenolone-type-steroids-from-the-east-african-basidiomycete-fomitiporia-aethiopica
#6
Clara Chepkirui, Winnie C Sum, Tian Cheng, Josphat C Matasyoh, Cony Decock, Marc Stadler
A mycelial culture of the Kenyan basidiomycete Fomitiporia aethiopica was fermented on rice and the cultures were extracted with methanol. Subsequent HPLC profiling and preparative chromatography of its crude extract led to the isolation of five previously undescribed pregnenolone type triterpenes 1-5, for which we propose the trivial name aethiopinolones A-E. The chemical structures of the aethiopinolones were determined by extensive 1D- and 2D-NMR, and HRMS data analysis. The compounds exhibited moderate cytotoxic effects against various human cancer cell lines, but they were found devoid of significant nematicidal and antimicrobial activities...
February 9, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29424600/comparison-of-the-hepatic-and-thyroid-gland-effects-of-sodium-phenobarbital-and-pregnenolone-16%C3%AE-carbonitrile-in-wild-type-and-constitutive-androstane-receptor-car-pregnane-x-receptor-pxr-knockout-rats
#7
Corinne Haines, Lynsey R Chatham, Audrey Vardy, Clifford R Elcombe, John R Foster, Brian G Lake
1. The hepatic and thyroid gland effects of the constitutive androstane receptor (CAR) activator sodium phenobarbital (NaPB) and the pregnane X receptor (PXR) activator pregnenolone-16α-carbonitrile (PCN) were examined in male Sprague-Dawley wild type (WT) and knockout (KO) rats lacking both hepatic CAR and PXR receptors (CAR KO/PXR KO rats). 2. The treatment of WT rats for 7 days with 500 ppm NaPB in the diet and 100 mg/kg/day PCN by gavage resulted in increased relative liver weight, hepatocyte hypertrophy, increased hepatocyte replicative DNA synthesis (RDS) and induction of cytochrome P450 CYP2B and CYP3A subfamily enzymes...
February 9, 2018: Xenobiotica; the Fate of Foreign Compounds in Biological Systems
https://www.readbyqxmd.com/read/29421409/prenatal-exposure-to-glycol-ethers-and-sex-steroid-hormones-at-birth
#8
Charline Warembourg, Anne-Claire Binter, Frank Giton, Jean Fiet, Laurence Labat, Christine Monfort, Cécile Chevrier, Luc Multigner, Sylvaine Cordier, Ronan Garlantézec
BACKGROUND: Glycol ethers (GEs) are oxygenated solvents widely found in occupational and consumer water-based products. Some of them are well-known reproductive and developmental toxicants. OBJECTIVES: To study the variations in circulating sex steroid hormones, measured in cord blood, according to biomarkers of prenatal GE exposure. METHODS: The study population comes from the PELAGIE mother-child cohort, which enrolled pregnant women from Brittany (France, 2002-2006)...
January 31, 2018: Environment International
https://www.readbyqxmd.com/read/29420188/human-3beta-hydroxysteroid-dehydrogenase-deficiency-associated-with-normal-spermatic-numeration-despite-a-severe-enzyme-deficit
#9
Bruno Donadille, Muriel Houang, Irene Netchine, Jean-Pierre Siffroi, Sophie Christin-Maitre
Human 3 beta-hydroxysteroid dehydrogenase deficiency (3b-HSD) is a very rare form of congenital adrenal hyperplasia resulting from HSD3B2 gene mutations. Its estimated prevalence is less than 1/1,000,000 male neonates. It leads to steroidogenesis impairment in both adrenals and gonads. Few data are available on adult testicular function in such patients. Therefore, we evaluated gonadal axis and testicular function in a 46,XY adult patient, carrying a HSD3B2 mutation. The patient presented at birth with neonatal salt wasting syndrome, a micropenis, perineal hypospadias and intrascrotal testes...
February 2, 2018: Endocrine Connections
https://www.readbyqxmd.com/read/29402482/taxifolin-suppresses-rat-and-human-testicular-androgen-biosynthetic-enzymes
#10
Fei Ge, Erpo Tian, Li Wang, Xiaoheng Li, Qiqi Zhu, Yiyan Wang, Ying Zhong, Ren-Shan Ge
Taxifolin is a flavonoid. It has been used as a chemopreventive agent and supplement. It may have some beneficial effects to treat prostate cancer by suppressing androgen production in Leydig cells. The objective of the present study was to study the effects of taxifolin on androgen production of rat Leydig cells isolated from immature testis and some rat and human testosterone biosynthetic enzyme activities. Rat Leydig cells were incubated with 100μM taxifolin without (basal) or with 10ng/ml luteinizing hormone (LH), 10mM 8-bromoadenosine 3',5'-cyclic monophosphate (8BR), and steroid enzyme substrates (20μM): 22R-hydroxychloesterol, pregnenolone, progesterone, and androstenedione...
February 2, 2018: Fitoterapia
https://www.readbyqxmd.com/read/29402198/the-essential-role-of-gata6-in-the-activation-of-estrogen-synthesis-in-endometriosis
#11
Lia A Bernardi, Matthew T Dyson, Hideki Tokunaga, Christia Sison, Muge Oral, Jared C Robins, Serdar E Bulun
Endometriotic stromal cells synthesize estradiol via the steroidogenic pathway. Nuclear receptor subfamily 5, group A, member 1 (NR5A1) is critical, but alone not sufficient, in activating this cascade that involves at least 5 genes. To evaluate whether another transcription factor is required for the activation of this pathway, we examined whether GATA Binding Protein 6 (GATA6) can transform a normal endometrial stromal cell (NoEM) into an endometriotic-like cell by conferring an estrogen-producing phenotype...
January 1, 2018: Reproductive Sciences
https://www.readbyqxmd.com/read/29368357/puerarin-inhibits-trpm3-mir-204-to-promote-mc3t3-e1-cells-proliferation-differentiation-and-mineralization
#12
Xiangwei Zeng, Qian Feng, Fengming Zhao, Chao Sun, Tao Zhou, Jing Yang, Xiuqin Zhan
Puerarin is an isoflavonoid phytoestrogen extracted from the root of Radix Pueraria, has attracted increasing attention because of its beneficial effects on anti-osteoporosis, but the molecular mechanisms underlying its actions on osteoblasts are not fully understood. The current study aimed to investigate the effect of puerarin on MC3T3-E1 osteoblastic cells proliferation, differentiation and mineralization, in vitro and its underlying mechanisms. The results indicated that puerarin significantly promoted the osteoblasts proliferation, enhanced alkaline phosphatase activity and increased the formation of mineralized nodules...
January 24, 2018: Phytotherapy Research: PTR
https://www.readbyqxmd.com/read/29360536/synthesis-and-cytotoxic-effect-of-pregnenolone-derivatives-with-one-or-two-%C3%AE-%C3%AE-unsaturated-carbonyls-and-an-ester-moiety-at-c-21-or-c-3
#13
Alejandra Chávez-Riveros, Abigail Cruz Noriega, María Teresa Ramírez Apan, Luis D Miranda, Eugene Bratoeff
Four series of pregnenolone derivatives having one or two α,β-unsaturated carbonyls and an ester moiety at C-3 or C-21 were synthetized to compare their cytotoxicity effect. The final compounds were evaluated on three human cancer cell lines: PC-3 (prostate cancer), MCF-7 (breast cancer), SKLU-1 (lung cancer) and a noncancerous cell line HGF (human gingival fibroblast). Two steroids with a 4-fluorinated benzoic acid ester at C-21 were the most active against lung cancer cell line with IC50 of 13.1±1.2 and 12...
January 19, 2018: Steroids
https://www.readbyqxmd.com/read/29360535/microbial-biotransformation-of-bioactive-and-clinically-useful-steroids-and-some-salient-features-of-steroids-and-biotransformation
#14
REVIEW
Nighat Sultana
Steroids are perhaps one of the most widely used group of drugs in present day. Beside the established utilization as immunosuppressive, anti-inflammatory, anti-rheumatic, progestational, diuretic, sedative, anabolic and contraceptive agents, recent applications of steroid compounds include the treatment of some forms of cancer, osteoporosis, HIV infections and treatment of declared AIDS. Steroids isolated are often available in minute amounts. So biotransformation of natural products provides a powerful means in solving supply problems in clinical trials and marketing of the drug for obtaining natural products in bulk amounts...
January 19, 2018: Steroids
https://www.readbyqxmd.com/read/29339451/inhibition-of-5%C3%AE-reductase-alters-pregnane-metabolism-in-the-late-pregnant-mare
#15
Michelle Wynn, Barry A Ball, Erin Lea Legacki, Alan Conley, Shavahn Loux, John May, Alejandro Esteller-Vico, Scott D Stanley, Kirsten Scoggin, Edward L Squires, Mats Ht Troedsson
In the latter half of gestation in the mare, progesterone concentrations decline to near undetectable levels while other 5α-reduced pregnanes are elevated. Of these, 5α-dihydroprogesterone and allopregnanolone have been reported to have important roles in either pregnancy maintenance or fetal quiescence. During this time, the placenta is necessary for pregnane metabolism, with the enzyme 5α-reductase being required for the conversion of progesterone to 5α-dihydroprogesterone. The objectives of this study were to assess the effects of a 5α-reductase inhibitor, dutasteride, on pregnane metabolism (pregnenolone, progesterone, 5α-dihydroprogesterone, 20α-hydroxy-5α-pregnan-3-one, 5α-pregnane-3β,20α-diol, and allopregnanolone), to determine circulating dutasteride concentrations, and to assess effects of dutasteride treatment on gestational parameters...
January 16, 2018: Reproduction: the Official Journal of the Society for the Study of Fertility
https://www.readbyqxmd.com/read/29309761/activation-of-nuclear-receptor-pxr-impairs-glucose-tolerance-and-dysregulates-glut2-expression-and-subcellular-localization-in-liver
#16
Fatemeh Hassani-Nezhad-Gashti, Jaana Rysä, Outi Kummu, Juha Näpänkangas, Marcin Buler, Mikko Karpale, Janne Hukkanen, Jukka Hakkola
Pregnane X receptor (PXR) is a nuclear receptor that senses chemical environment and is activated by numerous clinically used drugs and environmental contaminants. Previous studies have indicated that several drugs known to activate PXR appear to induce glucose intolerance. We now aimed to reveal the role of PXR in drug-induced glucose intolerance and characterize the mechanisms involved. We used PXR knockout mice model to investigate the significance of this nuclear receptor in the regulation of glucose tolerance...
January 5, 2018: Biochemical Pharmacology
https://www.readbyqxmd.com/read/29287832/progesterone-modulates-microtubule-dynamics-and-epiboly-progression-during-zebrafish-gastrulation
#17
Stephanie Eckerle, Mario Ringler, Virginie Lecaudey, Roland Nitschke, Wolfgang Driever
Control of microtubule dynamics is crucial for cell migration. We analyzed regulation of microtubule network dynamics in the zebrafish yolk cell during epiboly, the earliest coordinated gastrulation movement. We labeled microtubules with EMTB-3GFP and EB3-mCherry to visualize and measure microtubule dynamics by TIRF microscopy live imaging. Yolk cell microtubules dynamics is temporally modulated during epiboly progression. We used maternal zygotic Pou5f3 mutant (MZspg) embryos, which develop strong distortions of microtubule network organization and epiboly retardation, to investigate genetic control of microtubule dynamics...
December 26, 2017: Developmental Biology
https://www.readbyqxmd.com/read/29283561/human-p450-cyp17a1-control-of-substrate-preference-by-asparagine-202
#18
Michael C Gregory, Piotr J Mak, Yogan Khatri, James R Kincaid, Stephen G Sligar
CYP17A1 is a key steroidogenic enzyme known to conduct several distinct chemical transformations on multiple substrates. In its hydroxylase activity this enzyme adds a hydroxyl group at the 17α-position of both pregnenolone and progesterone at approximately equal rates. However, the subsequent 17,20 carbon-carbon scission reaction displays variable substrate speci-ficity in the numerous CYP17A1 isozymes operating in verte-brates, manifesting as different Kd and kcat values when presented with 17α-hydroxypregnenlone (OHPREG) versus 17α-hydroxyprogesterone (OHPROG)...
December 28, 2017: Biochemistry
https://www.readbyqxmd.com/read/29228121/low-dose-bisphenol-a-activates-the-erk-signaling-pathway-and-attenuates-steroidogenic-gene-expression-in-human-placental-cells
#19
Po-Wei Chu, Zhi-Jie Yang, Huei-Shing Huang, Ai-An Chang, Yu-Chen Cheng, Gwo-Jang Wu, Hsin-Chieh Lan
Bisphenol A (BPA) is an industrial material used for many plastic products and is considered an endocrine disruptor. BPA can be released into the environment and can spread through the food chain. It is well known that BPA exposure leads to lesions, especially in the reproductive system. According to previous studies, BPA reduces newborn numbers in pregnant mice and affects placentation. The placenta is a special endocrine organ during pregnancy. It secretes important hormones, such as progesterone and estrogen, to maintain gestation...
December 4, 2017: Biology of Reproduction
https://www.readbyqxmd.com/read/29212707/inherent-steroid-17%C3%AE-20-lyase-activity-in-defunct-cytochrome-p450-17a-enzymes
#20
Eric Gonzalez, Kevin M Johnson, Pradeep S Pallan, Thanh T N Phan, Wei Zhang, L I Lei, Zdzislaw Wawrzak, Francis K Yoshimoto, Martin Egli, F Peter Guengerich
Cytochrome P450 (P450) 17A1 catalyzes the oxidations of progesterone and pregnenolone and is the major source of androgens. The enzyme catalyzes both 17α-hydroxylation and a subsequent 17α, 20-lyase reaction, and several mechanisms have been proposed for the latter step. Zebrafish P450 17A2 catalyzes only the 17α-hydroxylations. We previously reported high similarity of the crystal structures of zebrafish P450 17A1 and 17A2 and human P450 17A1 (Pallan et al. (2015) J. Biol. Chem. 290, 3248- 3268). Five residues near the heme, which differed, were changed...
December 6, 2017: Journal of Biological Chemistry
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