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Pregnenolone

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https://www.readbyqxmd.com/read/28302174/feedback-inhibition-of-creb-signaling-by-p38-mapk-contributes-to-the-negative-regulation-of-steroidogenesis
#1
Jiaxin Li, Qian Zhou, Zhuang Ma, Meina Wang, Wen-Jun Shen, Salman Azhar, Zhigang Guo, Zhigang Hu
BACKGROUND: Steroidogenesis is a complex, multi-steps biological process in which, cholesterol precursor is converted to steroids in a tissue specific and tropic hormone dependent manner. Given that steroidogenesis is achieved by coordinated functioning of multiple tissue specific enzymes, many steroids intermediates/metabolites are generated during this process. Both the steroid products as well as major lipoprotein cholesterol donor, high-density lipoprotein 3 (hHDL3) have the potential to negatively regulate steroidogenesis via increased oxidative stress/reactive oxygen species (ROS) generation...
March 16, 2017: Reproductive Biology and Endocrinology: RB&E
https://www.readbyqxmd.com/read/28300583/synthesis-of-new-c-25-and-c-26-steroidal-acids-as-potential-ligands-of-the-nuclear-receptors-daf-12-lxr-and-gr
#2
María V Dansey, María C Del Fueyo, Adriana S Veleiro, Pablo H Di Chenna
A new methodology to obtain C-25 and C-26 steroidal acids starting from pregnenolone is described. Construction of the side chain was achieved by applying the Mukaiyama aldol reaction with a non-hydrolytic work-up to isolate the trapped silyl enol ether with higher yields. Using this methodology we synthesized three new steroidal acids as potential ligands of DAF-12, Liver X and Glucocorticoid nuclear receptors and studied their activity in reporter gene assays. Our results show that replacement of the 21-CH3 by a 20-keto group in the side chains of the cholestane scaffold of DAF-12 or Liver X receptors ligands causes the loss of the activity...
March 11, 2017: Steroids
https://www.readbyqxmd.com/read/28295471/long-term-feeding-of-hydroalcoholic-extract-powder-of-lepidium-meyenii-maca-enhances-the-steroidogenic-ability-of-leydig-cells-to-alleviate-its-decline-with-ageing-in-male-rats
#3
K Yoshida, Y Ohta, N Kawate, M Takahashi, T Inaba, S Hatoya, H Morii, K Takahashi, M Ito, H Tamada
This study examined whether feeding hydroalcoholic extract of Lepidium meyenii (maca) to 8-week-old (sexually maturing) or 18-week-old (mature) male rats for more than a half year affects serum testosterone concentration and testosterone production by Leydig cells cultured with hCG, 22R-hydroxycholesterol or pregnenolone. Testosterone concentration was determined in the serum samples obtained before and 6, 12, 18 and 24 weeks after the feeding, and it was significantly increased only at the 6 weeks in the group fed with the maca extract to maturing rats when it was compared with controls...
March 10, 2017: Andrologia
https://www.readbyqxmd.com/read/28274746/transcription-factors-sf1-and-cjun-cooperate-to-activate-the-fdx1-promoter-in-ma-10-leydig-cells
#4
Pauline Roumaud, Arlette Rwigemera, Luc J Martin
The Ferredoxin 1 (FDX1) protein supports steroid biosynthesis in steroidogenic cells through electron transfer to the rate-limiting steroidogenic enzyme, CYP11A1. The latter catalyzes the conversion of cholesterol to pregnenolone through side chain cleavage inside the mitochondria. Thus far, only several transcription factors have been implicated in the regulation of mouse Fdx1 promoter activity in Leydig cells. These include the nuclear receptor SF1 and SP1. Since two conserved regulatory elements for AP1 transcription factors have been located at -764 and -617bp of the Fdx1 promoter, we hypothesized that cJUN may cooperate with other partners to regulate Fdx1 in Leydig cells...
March 6, 2017: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28254952/effects-of-microrna-34a-on-the-pharmacokinetics-of-cytochrome-p450-probe-drugs-in-mice
#5
Joseph L Jilek, Ye Tian, Ai-Ming Yu
MicroRNAs (miR) including miR-34a have been shown to regulate nuclear receptor, drug-metabolizing enzyme and transporter gene expression in various cell model systems. However, to what degree miRNAs would affect pharmacokinetics (PK) at the systemic level remains unknown. Additionally, miR-34a replacement therapy represents a new cancer treatment strategy, whereas it is undefined if miR-34a therapeutics would causes any drug-drug interactions (DDI). To address the questions, we developed a practical single-mouse PK approach and investigated the effects of a bioengineered miR-34a agent on the PK of multiple Cytochrome P450 (CYP) probe drugs (midazolam, dextromethorphan, phenacetin, diclofenac, and chlorzoxazone) administered as a cocktail to mouse models...
March 2, 2017: Drug Metabolism and Disposition: the Biological Fate of Chemicals
https://www.readbyqxmd.com/read/28237809/pregnenolone-16%C3%AE-carbonitrile-ameliorates-concanavalin-a-induced-liver-injury-in-mice-independent-of-the-nuclear-receptor-pxr-activation
#6
Susumu Kodama, Takuto Shimura, Hideaki Kuribayashi, Taiki Abe, Kouichi Yoshinari
The pregnane X receptor (PXR) is well-known as a key regulator of drug/xenobiotic clearance. Upon activation by ligand, PXR transcriptionally upregulates the expression of drug-metabolizing enzymes and drug transporters. Recent studies have revealed that PXR also plays a role in regulating immune/inflammatory responses. Specific PXR activators, including synthetic ligands and phytochemicals, have been shown to ameliorate chemically induced colitis in mice. In this study, we investigated an anti-inflammatory effect of pregnenolone 16α-carbonitrile (PCN), a prototypical activator for rodent PXR, in concanavalin A (Con A)-induced liver injury, a model of immune-mediated liver injury, using wild-type and Pxr(-/-) mice...
February 22, 2017: Toxicology Letters
https://www.readbyqxmd.com/read/28220044/pregnenolone-blocks-cannabinoid-induced-acute-psychotic-like-states-in-mice
#7
A Busquets-Garcia, E Soria-Gómez, B Redon, Y Mackenbach, M Vallée, F Chaouloff, M Varilh, G Ferreira, P-V Piazza, G Marsicano
Cannabis-induced acute psychotic-like states (CIAPS) represent a growing health issue, but their underlying neurobiological mechanisms are poorly understood. The use of antipsychotics and benzodiazepines against CIAPS is limited by side effects and/or by their ability to tackle only certain aspects of psychosis. Thus, safer wide-spectrum treatments are currently needed. Although the blockade of cannabinoid type-1 receptor (CB1) had been suggested as a therapeutical means against CIAPS, the use of orthosteric CB1 receptor full antagonists is strongly limited by undesired side effects and low efficacy...
February 21, 2017: Molecular Psychiatry
https://www.readbyqxmd.com/read/28213302/disrupting-effects-of-azocyclotin-to-the-hypothalamo-pituitary-gonadal-axis-and-reproduction-of-xenopus-laevis
#8
Shuying Li, Meng Li, Wenjun Gui, Qiangwei Wang, Guonian Zhu
Over the past few decades, the hazards associated with the extensive use of organictin compounds have become an issue of extreme concern, while at present the effects of these substances on amphibians remain poorly understood. In the present study, we chose azocyclotin, one of common use acaricides in China. We focused on sexual development and steroidogenesis disrupting effects of azocyclotin in the Xenopus laevis. Tadpoles were exposed to azocyclotin (0.05 and 0.5μg/L) for long-term (4 months) study. Results showed that exposure to azocyclotin caused developmental toxicity, including decreased survival, body weight, body length, gonadosomatic index, hepatosomatic index and female phenotype...
April 2017: Aquatic Toxicology
https://www.readbyqxmd.com/read/28205173/measurement-of-mitochondrial-cholesterol-import-using-a-mitochondria-targeted-cyp11a1-fusion-construct
#9
Barry E Kennedy, Mark Charman, Barbara Karten
All animal membranes require cholesterol as an essential regulator of biophysical properties and function, but the levels of cholesterol vary widely among different subcellular compartments. Mitochondria, and in particular the inner mitochondrial membrane, have the lowest levels of cholesterol in the cell. Nevertheless, mitochondria need cholesterol for membrane maintenance and biogenesis, as well as oxysterol, steroid, and hepatic bile acid production. Alterations in mitochondrial cholesterol have been associated with a range of pathological conditions, including cancer, hepatosteatosis, cardiac ischemia, Alzheimer's, and Niemann-Pick Type C Disease...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28202325/synthesis-and-biological-evaluation-of-heterocyclic-analogues-of-pregnenolone-as-novel-anti-osteoporotic-agents
#10
Saransh Wales Maurya, Kapil Dev, Krishna Bhan Singh, Reena Rai, Ibadur Rahman Siddiqui, Divya Singh, Rakesh Maurya
The structural modifications of pregnenolone have been described via the introduction of heterocyclic moieties at C-17 position by limiting the acyl group. Novel heterocyclic analogues of pregnenolone have been synthesized by using Friedlander and Claisen-Schmidt reactions, and the synthesized compounds were evaluated for their osteogenic activity. Among the synthesized derivatives, four compounds showed significantly increased ALP activity. Among all four active compounds, the novel compound 3a has shown significant bone matrix mineralization and mRNA expressions of osteogenic marker genes, BMP2, RUNX-2 and OCN at 1pM concentration...
February 4, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/28129443/anxiolytic-effects-of-hippocampal-neurosteroids-in-normal-and-neuropathic-rats-with-spared-nerve-injury
#11
Meng Zhang, Jia Liu, Meng-Meng Zhou, Honghai Wu, Yanning Hou, Yun-Feng Li, Yuxin Yin, Lemin Zheng, Jie Cai, Fei-Fei Liao, Feng-Yu Liu, Ming Yi, You Wan
Neurosteroids are synthesized in the nervous system from cholesterol or steroidal precursors imported from peripheral sources. These compounds are important allosteric modulators of GABAA receptors, which play a vital role in modulating hippocampal functions. Chronic pain is accompanied by increased neurosteroid production in the spinal cord and thalamus. We hypothesize that hippocampal neurosteroids participate in pain or pain-associated emotions, which we tested with high-performance liquid chromatography/tandem mass spectrometry and pharmacological behavioral tests...
January 27, 2017: Journal of Neurochemistry
https://www.readbyqxmd.com/read/28115639/combined-effects-of-gestational-phthalate-exposure-and-zinc-deficiency-on-steroid-metabolism-and-growth
#12
J Nuttall, H R Kucera, S Supasai, N W Gaikwad, P I Oteiza
Disruption of steroid hormone signaling has been implicated independently in the developmental abnormalities resulting from maternal phthalate plasticizer exposure and developmental zinc deficiency. This study investigated if secondary zinc deficiency may result from dietary exposure to a low level of DEHP through gestation and if this could be associated with altered steroid metabolism. The interaction between marginal zinc nutrition and DEHP exposure to affect pregnancy outcome, zinc status, and steroid metabolism was also assessed...
January 23, 2017: Toxicological Sciences: An Official Journal of the Society of Toxicology
https://www.readbyqxmd.com/read/28114089/-non-conventional-pharmacological-agents-for-the-treatment-of-bipolar-disorder-%C3%AE-systematic-review-of-the-evidence
#13
K N Fountoulakis, D Balaris, V Nikolaou, J Νimatoudis
Bipolar disorder (BD) has a complex and variable clinical picture which is characterized by many different phacets and phases and as a result its therapeutical options are also complex and often unsatisfactory. Typically the so-called "mood stabilizers" are used in the treatment of BD and in this class lithium and specific antiepileptics are included. The present study aimed to systematically review the literature concerning the presence of randomized double blind clinical trials of 'non conventional' pharmaceutical treatment options...
October 2016: Psychiatrikē, Psychiatriki
https://www.readbyqxmd.com/read/28112420/extracellular-signal-regulated-protein-kinase-c-jun-n-terminal-protein-kinase-and-calcineurin-regulate-transient-receptor-potential-m3-trpm3-induced-activation-of-ap-1
#14
Andrea Lesch, Oliver G Rössler, Gerald Thiel
Stimulation of transient receptor potential M3 (TRPM3) cation channels with pregnenolone sulfate induces an influx of Ca(2+) ions into the cells and a rise in the intracellular Ca(2+) concentration, leading to the activation of the activator protein-1 (AP-1) transcription factor. Here, we show that expression of a constitutively active mutant of the Ca(2+) /calmodulin-dependent protein phosphatase calcineurin attenuated pregnenolone sulfate-induced AP-1 activation in TRPM3-expressing cells. Likewise, expression of the regulatory B subunit of calcineurin reduced AP-1 activity in the cells following stimulation of TRPM3 channels...
January 23, 2017: Journal of Cellular Biochemistry
https://www.readbyqxmd.com/read/28110963/hyperforin-activates-gene-transcription-involving-transient-receptor-potential-c6-channels
#15
Gerald Thiel, Oliver G Rössler
Hypericum perforatum is one of the most prominent medical plants. Hyperforin, a main ingredient of H. perforatum, has been shown to activate transient receptor potential canonical C6 (TRPC6) channels. Alternatively, it has been proposed that hyperforin functions as a protonophore in a TRPC6-independent manner. Here, we show that hyperforin stimulation activates the transcription factor AP-1 in HEK293 cells expressing TRPC6 (T6.11 cells), but did not substantially change the AP-1 activity in HEK293 cells lacking TRPC6...
January 19, 2017: Biochemical Pharmacology
https://www.readbyqxmd.com/read/28106668/primidone-inhibits-trpm3-and-attenuates-thermal-nociception-in-vivo
#16
Ute Krügel, Isabelle Straub, Holger Beckmann, Michael Schaefer
The melastatin-related transient receptor potential channel TRPM3 is a nonselective cation channel expressed in nociceptive neurons and activated by heat. Since TRPM3-deficient mice show inflammatory thermal hyperalgesia, pharmacological inhibition of TRPM3 may exert antinociceptive properties. Fluorometric Ca influx assays and a compound library containing approved or clinically tested drugs were used to identify TRPM3 inhibitors. Biophysical properties of channel inhibition were assessed using electrophysiological methods...
January 12, 2017: Pain
https://www.readbyqxmd.com/read/28104494/thoughts-on-interactions-between-pgrmc1-and-diverse-attested-and-potential-hydrophobic-ligands
#17
REVIEW
Michael A Cahill, Amy E Medlock
Progesterone Receptor Membrane Component 1 (PGRMC1) is located in many different subcellular locations with many different attested and probably location-specific functions. PGRMC1 was recently identified in the mitochondrial outer membrane where it interacts with ferrochelatase, the last enzyme in the heme synthetic pathway. It has been proposed that PGRMC1 may act as a chaperone to shuttle newly synthesized heme from the mitochondrion to cytochrome P450 (cyP450) enzymes. Here we consider potential roles that PGRMC1 may play in transferring heme, and other small hydrophobic ligands such as cholesterol and steroids, between the hydrophobic compartment of the membrane lipid bilayer interior to aqueous proteins, and perhaps to the membranes of other organelles...
January 16, 2017: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28102853/skin-to-skin-contact-after-birth-and-the-natural-course-of-neurosteroid-levels-in-healthy-term-newborns
#18
K R McCallie, N W Gaikwad, M E Castillo Cuadrado, M Aleman, J E Madigan, D K Stevenson, V K Bhutani
OBJECTIVE: To determine the postnatal course of neurosteroid levels in relation to gender, mode of delivery and the extent of skin-to-skin (STS) contact during the first days of life in healthy term newborns. STUDY DESIGN: Prospective observational study of 39 neonates in which parents recorded total duration of STS in the first 2 days and nine neurosteroids (dehydroepiandrosterone-sulfate, progesterone, pregnenolone, pregnenolone-sulfate, allopregnanolone, isopregnanolone, epipregnanolone, pregnanolone and pregnanolone-sulfate) were assayed from blood samples at birth and at 1-2 days of age...
January 19, 2017: Journal of Perinatology: Official Journal of the California Perinatal Association
https://www.readbyqxmd.com/read/28091906/effect-of-mifepristone-on-corticosteroid-production-in-vitro-by-adrenal-glands-of-rats-with-streptozotocin-diabetes
#19
N V Kuznetsova, N A Palchikova, V G Selyatitskaya, O I Kuzminova
Changes in pregnenolone and corticosterone production by the adrenal glands of normoglycemic rats receiving the course of intraperitoneal mifepristone or NaCl administration were co-directed, but differed in magnitude. In rats with hyperglycemia, corticosteroid production increased after NaCl administration over 5 days and returned to the initial values after 15-day administration. On the contrary, pregnenolone and corticosterone production was suppressed after 5-day course of mifepristone, but significantly increased after mifepristone administration for 15 days...
January 2017: Bulletin of Experimental Biology and Medicine
https://www.readbyqxmd.com/read/27974436/genetic-and-targeted-eqtl-mapping-reveals-strong-candidate-genes-modulating-the-stress-response-during-chicken-domestication
#20
Amir Fallahsharoudi, Neil de Kock, Martin Johnsson, Lejla Bektic, S J Kumari A Ubhayasekera, Jonas Bergquist, Dominic Wright, Per Jensen
The stress response has been largely modified in all domesticated animals, offering a strong tool for genetic mapping. In chickens, ancestral Red Junglefowl react stronger both in terms of physiology and behavior to a brief restraint stress than domesticated White Leghorn, demonstrating modified functions of the hypothalamic-pituitary-adrenal (HPA) axis. We mapped quantitative trait loci (QTL) underlying variations in stress-induced hormone levels using 232 birds from the 12th generation of an advanced intercross between White Leghorn and Red Junglefowl, genotyped for 739 genetic markers...
February 9, 2017: G3: Genes—Genomes—Genetics
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