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Pregnenolone

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https://www.readbyqxmd.com/read/28520937/atypical-endocannabinoid-signaling-initiates-a-new-form-of-memory-related-plasticity-at-a-cortical-input-to-hippocampus
#1
Weisheng Wang, Yousheng Jia, Danielle T Pham, Linda C Palmer, Kwang-Mook Jung, Conor D Cox, Gavin Rumbaugh, Daniele Piomelli, Christine M Gall, Gary Lynch
Endocannabinoids (ECBs) depress transmitter release at sites throughout the brain. Here, we describe another form of ECB signaling that triggers a novel form of long-term potentiation (LTP) localized to the lateral perforant path (LPP) which conveys semantic information from cortex to hippocampus. Two cannabinoid CB1 receptor (CB1R) signaling cascades were identified in hippocampus. The first is pregnenolone sensitive, targets vesicular protein Munc18-1 and depresses transmitter release; this cascade is engaged by CB1Rs in Schaffer-Commissural afferents to CA1 but not in the LPP, and it does not contribute to LTP...
May 17, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/28507119/regulation-of-the-sperm-calcium-channel-catsper-by-endogenous-steroids-and-plant-triterpenoids
#2
Nadja Mannowetz, Melissa R Miller, Polina V Lishko
The calcium channel of sperm (CatSper) is essential for sperm hyperactivated motility and fertility. The steroid hormone progesterone activates CatSper of human sperm via binding to the serine hydrolase ABHD2. However, steroid specificity of ABHD2 has not been evaluated. Here, we explored whether steroid hormones to which human spermatozoa are exposed in the male and female genital tract influence CatSper activation via modulation of ABHD2. The results show that testosterone, estrogen, and hydrocortisone did not alter basal CatSper currents, whereas the neurosteroid pregnenolone sulfate exerted similar effects as progesterone, likely binding to the same site...
May 15, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28502863/synthesis-of-16%C3%AE-amino-pregnenolone-derivatives-via-ionic-liquid-catalyzed-aza-michael-addition-and-their-evaluation-as-c17-20-lyase-inhibitors
#3
Eszter Szánti-Pintér, Lilla Maksó, Ágnes Gömöry, Johan Wouters, Bianka Edina Herman, Mihály Szécsi, Gábor Mikle, László Kollár, Rita Skoda-Földes
Aza-Michael addition of 16-dehydropregnenolone was studied in the presence of a basic ionic liquid, [DBU][OAc] as catalyst and solvent. The reaction was carried out using different primary and secondary amines as N-nucleophiles. The products were obtained in moderate to good yields and were characterized by (1)H and (13)C NMR, MS and IR. The ionic liquid was found to be an efficient and recyclable catalyst that was reused five times. The products were investigated for the inhibition of in vitro C17,20-lyase activity and displayed moderate inhibitory effect...
May 11, 2017: Steroids
https://www.readbyqxmd.com/read/28479316/reference-intervals-for-plasma-concentrations-of-adrenal-steroids-measured-by-lc-ms-ms-impact-of-gender-age-oral-contraceptives-body-mass-index-and-blood-pressure-status
#4
Graeme Eisenhofer, Mirko Peitzsch, Denise Kaden, Katharina Langton, Christina Pamporaki, Jimmy Masjkur, George Tsatsaronis, Anastasios Mangelis, Tracy A Williams, Martin Reincke, Jacques W M Lenders, Stefan R Bornstein
BACKGROUND: Mass spectrometric-based measurements of the steroid metabolome have been introduced to diagnose disorders featuring abnormal steroidogenesis. Defined reference intervals are important for interpreting such data. METHODS: Liquid chromatography-tandem mass spectrometry was used to establish reference intervals for 16 steroids (pregnenolone, progesterone, 11-deoxycorticosterone, corticosterone, aldosterone, 18-oxocortisol, 18-hydroxycortisol, 17-hydroxyprogesterone, 21-deoxycortisol, 11-deoxycortisol, cortisol, cortisone, dehydroepiandrosterone, dehydroepiandrosterone-sulfate, androstenedione, testosterone) measured in plasma from 525 volunteers with (n=227) and without (n=298) hypertension, including 68 women on oral contraceptives...
May 4, 2017: Clinica Chimica Acta; International Journal of Clinical Chemistry
https://www.readbyqxmd.com/read/28472487/11-oxygenated-androgens-are-biomarkers-of-adrenal-volume-and-testicular-adrenal-rest-tumors-in-21-hydroxylase-deficiency
#5
Adina F Turcu, Ashwini Mallappa, Meredith Elman, Nilo A Avila, Jamie Marko, Hamsini Rao, Alexander Tsodikov, Richard J Auchus, Deborah P Merke
Context: Patients with 21-hydroxylase deficiency (21OHD) suffer from long-term complications, which might result from poor disease control and/or glucocorticoid overtreatment. Lack of optimal biomarkers has made it challenging to tailor therapy and to predict long-term outcomes. Objective: To identify biomarkers of disease control and long-term complications in 21OHD. Setting and participants: Cross-sectional study of 114 patients (70 males), ages 2 to 67 (median, 15) years, seen in a tertiary referral center...
May 1, 2017: Journal of Clinical Endocrinology and Metabolism
https://www.readbyqxmd.com/read/28471529/reduced-steroidogenesis-in-patients-with-pcdh19-female-limited-epilepsy
#6
Marina Trivisano, Chiara Lucchi, Cecilia Rustichelli, Alessandra Terracciano, Raffaella Cusmai, Grazia Maria Ubertini, Germana Giannone, Enrico Silvio Bertini, Federico Vigevano, Jozef Gecz, Giuseppe Biagini, Nicola Specchio
Patients affected by protocadherin 19 (PCDH19)-female limited epilepsy (PCDH19-FE) present a remarkable reduction in allopregnanolone blood levels. However, no information is available on other neuroactive steroids and the steroidogenic response to hormonal stimulation. For this reason, we evaluated allopregnanolone, pregnanolone, and pregnenolone sulfate by liquid chromatographic procedures coupled with electrospray tandem mass spectrometry in 12 unrelated patients and 15 age-matched controls. We also tested cortisol, estradiol, progesterone, and 17OH-progesterone using standard immunoassays...
May 4, 2017: Epilepsia
https://www.readbyqxmd.com/read/28467654/sterol-regulatory-element-binding-protein-1c-knockout-mice-show-altered-neuroactive-steroid-levels-in-sciatic-nerve
#7
Nico Mitro, Gaia Cermenati, Matteo Audano, Silvia Giatti, Marzia Pesaresi, Silvia Pedretti, Roberto Spezzano, Donatella Caruso, Roberto Cosimo Melcangi
Neuroactive steroid levels are altered in several experimental models of peripheral neuropathy, and on this basis, they have been proposed as protective agents. For the first time, the levels of these molecules were here assessed in sterol regulatory-binding protein-1c (SREBP-1c) knock-out (KO) male mice (i.e., an experimental model of peripheral neuropathy) and compared with observations in wild type animals. The levels of neuroactive steroids have been evaluated by liquid chromatography tandem mass spectrometry in plasma and sciatic nerve at two and ten months of age and these analyses were implemented analyzing the gene expression of crucial steroidogenic enzymes in sciatic nerve...
May 3, 2017: Journal of Neurochemistry
https://www.readbyqxmd.com/read/28466626/stimulatory-effect-of-food-restriction-on-the-steroidogenesis-of-aldosterone-in-ovariectomized-rats
#8
Mei-Mei Kau, Ching-Han Yu, Shiow-Chwen Tsai, Jiing-Rong Wang, Paulus S. Wang
Food or calorie restriction (FR or CR) induces several physiological changes including weight loss, metabolic adaptations, mineral and hormonal changes. However, the effects of FR on aldosterone steroidogenesis in zona glomerulosa (ZG) cells have not been elucidated. Therefore, the present study was designed to investigate the effects of FR on aldosterone secretion and the involved mechanisms in ovariectomized (Ovx) rats. Ovx rats were divided into ad libitum fed (control) and FR groups. The FR rats exhibited decreased body weight, water intake, urine flow, sodium excretion and increased plasma aldosterone in comparison with control rats...
April 30, 2017: Chinese Journal of Physiology
https://www.readbyqxmd.com/read/28458886/de-novo-disruption-of-promoter-and-exon-1-of-star-gene-reveals-essential-role-for-gonadal-development
#9
Anil Piya, Jasmeet Kaur, Alan M Rice, Himangshu S Bose
SUMMARY: Cholesterol transport into the mitochondria is required for synthesis of the first steroid, pregnenolone. Cholesterol is transported by the steroidogenic acute regulatory protein (STAR), which acts at the outer mitochondrial membrane prior to its import. Mutations in the STAR protein result in lipoid congenital adrenal hyperplasia (CAH). Although the STAR protein consists of seven exons, biochemical analysis in nonsteroidogenic COS-1 cells showed that the first two were not essential for pregnenolone synthesis...
2017: Endocrinology, Diabetes & Metabolism Case Reports
https://www.readbyqxmd.com/read/28458115/microtubule-associated-protein-2-in-bipolar-depression-impact-of-pregnenolone
#10
Shivani Daftary, Jung-Min Yon, Ehn-Kyoung Choi, Yun-Bae Kim, Collette Bice, Alexandra Kulikova, John Park, E Sherwood Brown
BACKGROUND: Pregnenolone, and related neurosteroids, may have antidepressant properties. Preclinical research proposes that microtubule associated protein 2 (MAP2) binding may be a mechanism for antidepressant properties of pregnenolone. Thus, MAP2 might be a novel target for antidepressant therapy. This clinical study is the first to examine serum MAP2 levels in people with bipolar depression and controls, and whether pregnenolone treatment is associated with a change in MAP2 levels...
April 19, 2017: Journal of Affective Disorders
https://www.readbyqxmd.com/read/28456011/neurosteroid-biosynthesis-downregulation-and-changes-in-gabaa-receptor-subunit-composition-a-biomarker-axis-in-stress-induced-cognitive-and-emotional-impairment
#11
REVIEW
Andrea Locci, Graziano Pinna
By rapidly modulating neuronal excitability, neurosteroids regulate physiological processes, such as responses to stress and development. Excessive stress affects their biosynthesis and causes an imbalance in cognition and emotions. The progesterone derivative, allopregnanolone (Allo) enhances extrasynaptic and postsynaptic inhibition by directly binding at GABAA receptors, and thus, positively and allosterically modulates the function of GABA. Allo levels are decreased in stress-induced psychiatric disorders, including depression and post-traumatic stress disorder (PTSD), and elevating Allo levels may be a valid therapeutic approach to counteract behavioural dysfunction...
April 29, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28455626/influences-of-flavones-on-cell-viability-and-camp-dependent-steroidogenic-gene-regulation-in-ma-10-leydig-cells
#12
Michelle Cormier, Firas Ghouili, Pauline Roumaud, William Bauer, Mohamed Touaibia, Luc J Martin
Testicular Leydig cells are major contributors of androgen synthesis and secretion, which play an important role in testis development, normal masculinization, maintenance of spermatogenesis, and general male fertility. The rate-limiting step in testosterone biosynthesis involves the transfer of cholesterol to the mitochondrial inner membrane by the steroidogenic acute regulatory (Star) protein, a critical factor in steroid hormone biosynthesis. Once inside the mitochondria, cholesterol is metabolized by the steroidogenic enzyme Cyp11a1 to pregnenolone, which is further converted to testosterone by the action of other steroidogenic enzymes...
April 28, 2017: Cell Biology and Toxicology
https://www.readbyqxmd.com/read/28428138/pregnane-x-receptor-regulates-the-ahr-cyp1a1-pathway-and-protects-liver-cells-from-benzo-%C3%AE-pyrene-induced-dna-damage
#13
Hongmei Cui, Xinsheng Gu, Jingshu Chen, Ying Xie, Sui Ke, Jing Wu, Andrei Golovko, Benjamin Morpurgo, Chunhong Yan, Timothy D Phillips, Wen Xie, Jianyuan Luo, Zhijun Zhou, Yanan Tian
Pregnane X receptor (PXR) plays an important role in protecting cells from mutagenic DNA damages induced by endogenous and exogenous toxicants. This protective function is often attributed to the PXR-regulated metabolic detoxification. Here we report a novel potential mechanism that PXR reduces benzo-[α]-pyrene(BaP)-induced DNA damage through inhibiting the transcriptional activity of aryl hydrocarbon receptor (AhR) which plays a pivotal role in the bioactivation of BaP. We have utilized three well-characterized cell lines, i...
April 18, 2017: Toxicology Letters
https://www.readbyqxmd.com/read/28411812/quantifying-endogenous-androgens-estrogens-pregnenolone-and-progesterone-metabolites-in-human-urine-by-gas-chromatography-tandem-mass-spectrometry
#14
Juan Robles, Josep Marcos, Nuria Renau, Lorena Garrostas, Jordi Segura, Rosa Ventura, Bernardí Barceló, Antonia Barceló, Oscar J Pozo
A method for the quantitation of 22 urinary steroids (androgens, estrogens and the main pregnenolone and progesterone metabolites) by means of gas chromatography tandem mass spectrometry using a triple quadrupole analyzer has been developed. Two different enzymatic hydrolysis protocols were investigated; one capable of releasing steroids present as both sulfates and glucuronides (total fraction), and another with β-glucuronidase activity only. After selecting adequate internal standards and choosing the optimal instrumental parameters, i...
July 1, 2017: Talanta
https://www.readbyqxmd.com/read/28410883/aminoglutethimide-induced-lysosomal-changes-in-adrenal-gland-in-mice
#15
Mayu Mutsuga, Yoshiji Asaoka, Naoko Imura, Tomoya Miyoshi, Yuko Togashi
Aminoglutethimide is a steroidogenesis inhibitor and inhibits a cholesterol side-chain cleavage enzyme (CYP11A1) that converts cholesterol to pregnenolone in mitochondria. We investigated histopathological changes induced by 5-day administration of AG in mice. Cytoplasmic vacuoles of various sizes and single cell necrosis were found in zona fasciculata cells in AG-treated mice. Some vacuoles were positive for adipophilin, whereas others were positive for lysosome-associated membrane protein-2 on immunohistochemical staining, indicating they were enlarged lipid droplets and lysosomes, respectively...
April 11, 2017: Experimental and Toxicologic Pathology: Official Journal of the Gesellschaft Für Toxikologische Pathologie
https://www.readbyqxmd.com/read/28408350/neuroactive-steroid-levels-and-psychiatric-and-andrological-features-in-post-finasteride-patients
#16
Roberto Cosimo Melcangi, Daniele Santi, Roberto Spezzano, Maria Grimoldi, Tommaso Tabacchi, Maria Letizia Fusco, Silvia Diviccaro, Silvia Giatti, Giuseppe Carrà, Donatella Caruso, Manuela Simoni, Guido Cavaletti
Recent reports show that, in patients treated with finasteride for male pattern hair loss, persistent side effects including sexual side effects, depression, anxiety and cognitive complaints may occur. We here explored the psychiatric and andrological features of patients affected by post-finasteride syndrome (PFS) and verified whether the cerebrospinal fluid (CSF) and plasma levels of neuroactive steroids (i.e., important regulators of nervous function) are modified. We found that eight out of sixteen PFS male patients considered suffered from a DSM-IV major depressive disorder (MDD)...
April 10, 2017: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28396219/novel-synthesis-of-steroidal-oximes-and-lactams-and-their-biological-evaluation-as-antiproliferative-agents
#17
Roxana Martínez-Pascual, Socorro Meza-Reyes, José Luis Vega-Baez, Penélope Merino-Montiel, José M Padrón, Ángel Mendoza, Sara Montiel-Smith
A novel three-step methodology to obtain 6a-aza-B-homo steroidal lactams has been developed starting from the easily available cholesterol and pregnenolone. In addition, a new procedure for the synthesis of a 6a-aza-B-homo steroidal lactam analog of vespertilin, starting from diosgenin has been established. In both synthetic pathways, the key intermediate is a hydroxyimino derivative obtained in a one- or two-step sequence from the starting materials. These methods avoid the use of hazardous oxidant agents in the process...
April 7, 2017: Steroids
https://www.readbyqxmd.com/read/28389510/association-of-tissue-abiraterone-levels-and-slco-genotype-with-intraprostatic-steroids-and-pathologic-response-in-men-with-high-risk-localized-prostate-cancer
#18
Elahe A Mostaghel, Eunpi Cho, Ailin Zhang, Mohammad Alyamani, Arja Kaipainen, Sean Green, Brett Marck, Nima Sharifi, Jonathan L Wright, Roman Gulati, Lawrence D True, Massimo Loda, Alvin M Matsumoto, Daniel Tamae, Trevor N Penning, Steven P Balk, Philip W Kantoff, Peter S Nelson, Mary-Ellen Taplin, Bruce Montgomery
Germline variation in solute carrier organic anion (SLCO) genes influences cellular steroid uptake and is associated with prostate cancer (PCa) outcomes. We hypothesized that, due to its steroidal structure, the CYP17A inhibitor abiraterone may undergo SLCO-mediated transport and that SLCO gene variation may influence intracellular abiraterone levels and outcomes.<br /><br />Experimental Design: Steroid and abiraterone levels were measured by mass spectrometry in serum and tissue from 58 men with localized PCa in a clinical trial of LHRH agonist plus abiraterone acetate plus prednisone for 24 weeks prior to prostatectomy...
April 7, 2017: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
https://www.readbyqxmd.com/read/28387522/mechanism-of-cytochrome-p450-17a1-catalyzed-hydroxylase-and-lyase-reactions
#19
Silvia Bonomo, Flemming Steen Jørgensen, Lars Olsen
Cytochrome P450 17A1 (CYP17A1) catalyzes C17 hydroxylation of pregnenolone and progesterone and the subsequent C17-C20 bond cleavage (lyase reaction) to form androgen precursors. Compound I (Cpd I) and peroxo anion (POA) are the heme-reactive species underlying the two reactions. We have characterized the reaction path for both the hydroxylase and lyase reactions using density functional theory (DFT) calculations and the enzyme-substrate interactions by molecular dynamics (MD) simulations. Activation barriers for positions subject to hydroxylase reaction have values close to each other and span from 54 to 60 kJ·mol(-1) with a small preference for 17α hydroxylation, in agreement with experimental observations...
April 19, 2017: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/28347660/effect-of-genetic-polymorphism-on-the-inhibition-of-dopamine-formation-from-p-tyramine-catalyzed-by-brain-cytochrome-p450-2d6
#20
Toshiro Niwa, Marina Shizuku, Kaori Yamano
The inhibitory effects of steroid hormones, including glucocorticoids such as cortisol, and related compounds on dopamine formation from p-tyramine, catalyzed by cytochrome P450 (CYP) 2D6.2 (Arg296Cys, Ser486Thr) and CYP2D6.10 (Pro34Ser, Ser486Thr) were compared with the effects of those catalyzed by CYP2D6.1 (wild type), to investigate the effect of a CYP2D6 polymorphism on neuroactive amine metabolism in the brain. Inhibition constants (Ki) or 50% inhibitory concentrations of six steroid hormones (cortisol, cortisone, corticosterone, dehydroepiandrosterone, progesterone, and pregnenolone) and quinidine and quinine-typical potent inhibitors of the human CYP2D6 and rat CYP2D subfamily, respectively-toward dopamine formation catalyzed by CYP2D6...
April 15, 2017: Archives of Biochemistry and Biophysics
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