scholarly journals Effects of polychlorinated biphenyl (Aroclor 1254) on steroidogenesis and antioxidant system in cultured adult rat Leydig cells

2007 ◽  
Vol 192 (2) ◽  
pp. 325-338 ◽  
Author(s):  
Palaniappan Murugesan ◽  
Muthusamy Balaganesh ◽  
Karundevi Balasubramanian ◽  
Jagadeesan Arunakaran
Keyword(s):  
Antioxidant System ◽  
Leydig Cells ◽  
Hydroxysteroid Dehydrogenase ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Rt Pcr ◽  
Steroidogenic Enzymes ◽  
Aroclor 1254 ◽  
Nonenzymatic Antioxidants ◽  
Dose Dependent

Polychlorinated biphenyls (PCBs) are ubiquitous and persistent environmental contaminants that disturb normal endocrine functions, including gonadal functions in humans and mammals. In the present study, we examined the direct effects of PCB on rat Leydig cells in vitro. Adult Leydig cells were purified by Percoll gradient centrifugation method and the purity of Leydig cells was also determined by 3β-hydroxysteroid dehydrogenase (3β-HSD) staining method. Purified Leydig cells were exposed to different concentrations (10− 10–10− 7 M) of PCB (Aroclor 1254) for 24 h under basal and LH-stimulated conditions. After the experimental period, cultured media were collected and used for the assay of testosterone and estradiol. The treated cells were used for the quantification of cell-surface LH receptors and activities of steroidogenic enzymes, such as cytochrome P450 side-chain cleavage enzyme (P450scc), 3β-HSD, and 17β-hydroxysteroid dehydrogenase (17β-HSD). Leydig cellular enzymatic antioxidants, such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, γ-glutamyl transpeptidase, glutathione-S-transferase, and nonenzymatic antioxidants, such as vitamins C and E, were assayed. Lipid peroxidation (LPO) and reactive oxygen species (ROS) were also estimated in Leydig cells. In addition, total RNA was isolated from control and Aroclor 1254-exposed Leydig cells to monitor the steady-state mRNA levels by reverse transcription(RT)-PCR for steroidogenic acute-regulatory (StAR) protein, cytochrome P450scc, 3β-HSD, and 17β-HSD. Our results indicated that Aroclor 1254 (10− 9, 10− 8, and 10− 7 M) treatments significantly inhibit basal and LH-stimulated testosterone and estradiol production. In addition, the activities of steroidogenic enzymes, enzymatic and nonenzymatic antioxidants were significantly diminished in a dose-dependent manner. However, LPO and ROS were elevated in a dose-dependent manner under basal and LH-stimulated conditions. RT-PCR analysis of StAR mRNA level showed a decrease only in 10− 7 M dose of Aroclor 1254 treatment, while cytochrome P450scc, 3β-HSD, and 17β-HSD mRNAs were drastically decreased in both 10− 8 and 10− 7 M Aroclor 1254 treatment. These findings suggest that PCBs can act directly on Leydig cells to diminish testosterone production by inhibiting gene expression of steroidogenic enzymes and antioxidant system.

scholarly journals A Novel Mechanism in Regulating the Alpha-Subunit of the Epithelial Sodium Channel (α ENaC) by the Alternatively Spliced Form α ENaC-b

2009 ◽  
Vol 2 ◽  
pp. BCI.S880 ◽  
Author(s):  
Marlene F. Shehata
Keyword(s):  
Sodium Channel ◽  
Epithelial Sodium Channel ◽  
Dominant Negative Effect ◽  
Kidney Cortex ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Rt Pcr ◽  
Alternatively Spliced ◽  
Dose Dependent

Introduction In Dahl rats’ kidney cortex, the alternatively spliced form of the epithelial sodium channel α subunit (α ENaC-b) is the most abundant mRNA transcript (32+/-3 fold > α ENaC-wt) as was investigated by quantitative RT-PCR analysis. α ENaC-b mRNA levels were significantly higher in Dahl R versus S rats, and were further augmented by high salt diet. Objectives In the present study, we described the molecular cloning and searched for a possible role of α ENaC-b by testing its potential expression in COS7 cells as well as its impact on α ENaC-wt expression levels when co-expressed in COS7 cells in a dose-dependent manner. Methods Using RT-PCR strategy, the full-length wildtype α ENaC transcript and the alternatively spliced form α ENaC-b were amplified, sequenced, cloned, subcloned into PCMV-sport6 expression vector, expressed and co-expressed into COS7 cells in a dose-dependent manner. A combination of denaturing and native western blotting techniques was employed to examine the expression of α ENaC-b in vitro, and to determine if an interaction between α ENaC-b and α ENaC-wt occurs in vitro, and finally to demonstrate if degradation of α ENaC-wt protein does occur. Results α ENaC-b is translated in COS7 cells. Co-expression of α ENaC-b together with α ENaC-wt reduced α ENaC-wt levels in a dose-dependent manner. α ENaC-wt and α ENaC-b appear to form a complex that enhances the degradation of α ENaC-wt. Conclusions Western blots suggest a novel mechanism in α ENaC regulation whereby α ENaC-b exerts a dominant negative effect on α ENaC-wt expression. This is potentially by sequestering α ENaC-wt, enhancing its proteolytic degradation, and possibly explaining the mechanism of salt-resistance in Dahl R rats.

scholarly journals Comparison of cell types in the rat Leydig cell lineage after ethane dimethanesulfonate treatment

Reproduction ◽  
2013 ◽  
Vol 145 (4) ◽  
pp. 371-380 ◽  
Author(s):  
Jingjing Guo ◽  
Hongyu Zhou ◽  
Zhijian Su ◽  
Bingbing Chen ◽  
Guimin Wang ◽  
...  
Keyword(s):  
Leydig Cell ◽  
Leydig Cells ◽  
Pubertal Development ◽  
Cell Lineage ◽  
Hydroxysteroid Dehydrogenase ◽  
Mrna Levels ◽  
Steroidogenic Enzymes ◽  
Isolated Cells ◽  
Adult Leydig Cells

The objective of this study was to purify cells in the Leydig cell lineage following regeneration after ethane dimethanesulfonate (EDS) treatment and compare their steroidogenic capacity. Regenerated progenitor (RPLCs), immature (RILCs), and adult Leydig cells (RALCs) were isolated from testes 21, 28 and 56 days after EDS treatment respectively. Production rates for androgens including androsterone and 5α-androstane-17β, 3α-diol (DIOL), testosterone and androstenedione were measured in RPLCs, RILCs and RALCs in media after 3-h in vitro culture with 100 ng/ml LH. Steady-state mRNA levels of steroidogenic enzymes and their activities were measured in freshly isolated cells. Compared to adult Leydig cells (ALCs) isolated from normal 90-day-old rat testes, which primarily produce testosterone (69.73%), RPLCs and RILCs primarily produced androsterone (70.21%) and DIOL (69.79%) respectively. Leydig cells isolated from testes 56 days post-EDS showed equivalent capacity of steroidogenesis to ALCs and primarily produced testosterone (72.90%). RPLCs had cholesterol side-chain cleavage enzyme, 3β-hydroxysteroid dehydrogenase 1 and 17α-hydroxylase but had almost no detectable 17β-hydroxysteroid dehydrogenase 3 and 11β-hydroxysteroid dehydrogenase 1 activities, while RILCs had increased 17β-hydroxysteroid dehydrogenase 3 and 11β-hydroxysteroid dehydrogenase 1 activities. Because RPLCs and RILCs had higher 5α-reductase 1 and 3α-hydroxysteroid dehydrogenase activities they produced mainly 5α-reduced androgens. Real-time PCR confirmed the similar trends for the expressions of these steroidogenic enzymes. In conclusion, the purified RPLCs, RILCs and RALCs are similar to those of their counterparts during rat pubertal development.

Oxygenation of 18-hydroxycorticosterone as the final reaction for aldosterone biosynthesis

1984 ◽  
Vol 107 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Itaru Kojima ◽  
Etsuro Ogata ◽  
Hiroshi Inano ◽  
Bun-ichi Tamaoki
Keyword(s):  
Carbon Monoxide ◽  
Hydroxysteroid Dehydrogenase ◽  
Dependent Manner ◽  
In Vitro Production ◽  
Mitochondrial Preparation ◽  
Final Reaction ◽  
Vitro Production ◽  
Dose Dependent ◽  
Cytochrome P 450

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.

Parathyroid Ca2+-conducting currents are modulated by muscarinic receptor agonists and antagonists

1997 ◽  
Vol 273 (5) ◽  
pp. E880-E890 ◽  
Author(s):  
Wenhan Chang ◽  
Tsui-Hua Chen ◽  
Stacy A. Pratt ◽  
Benedict Yen ◽  
Michael Fu ◽  
...  
Keyword(s):  
Muscarinic Receptors ◽  
Inositol Phosphate ◽  
Receptor Protein ◽  
Dependent Manner ◽  
Rt Pcr ◽  
Pipette Solution ◽  
Pcr Products ◽  
Inositol Phosphate Accumulation ◽  
Receptor Cdna ◽  
Dose Dependent

Parathyroid cells express Ca2+-conducting cation currents, which are activated by raising the extracellular Ca2+ concentration ([Ca2+]o) and blocked by dihydropyridines. We found that acetylcholine (ACh) inhibited these currents in a reversible, dose-dependent manner (50% inhibitory concentration ≈10−8 M). The inhibitory effects could be mimicked by the agonist (+)-muscarine. The effects of ACh were blunted by the antagonist atropine and reversed by removing ATP from the pipette solution. (+)-Muscarine enhanced the adenosine 3′,5′-cyclic monophosphate (cAMP) production by 30% but had no effect on inositol phosphate accumulation in parathyroid cells. Oligonucleotide primers, based on sequences of known muscarinic receptors (M1-M5), were used in reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify receptor cDNA from parathyroid poly (A)+ RNA. RT-PCR products displayed >90% nucleotide sequence identity to human M2- and M4-receptor cDNAs. Expression of M2-receptor protein was further confirmed by immunoblotting and immunocytochemistry. Thus parathyroid cells express muscarinic receptors of M2 and possibly M4 subtypes. These receptors may couple to dihydropyridine-sensitive, cation-selective currents through the activation of adenylate cyclase and ATP-dependent pathways in these cells.

scholarly journals Steroidogenic enzymes mRNA expression profile and steroids production in bovine theca cells cultured in vitro and stimulated with angiotensin II

2015 ◽  
Vol 45 (4) ◽  
pp. 704-710 ◽  
Author(s):  
Melânia Lazzari Rigo ◽  
Andressa Minussi Pereira Dau ◽  
Werner Giehl Glanzner ◽  
Manoel Martins ◽  
Renato Zanella ◽  
...  
Keyword(s):  
High Performance ◽  
Culture Media ◽  
Mrna Levels ◽  
Ang Ii ◽  
Rt Pcr ◽  
Steroidogenic Enzymes ◽  
Theca Cells ◽  
Mrna Profile ◽  
Dose Response Effect

The main objective of this study was to detect the steroidogenic effects of Ang II in bovine theca cells in vitro. Bovine theca cells were obtained from follicles (larger than 10mm of diameter) collected from a local abattoir and submitted to different treatments in a sequence of experiments. In experiment 1, CYP17A1 mRNA profile was evaluated in LH- (10ng ml-1) and Ang II-treated (0.1µM) theca cells. In experiment 2, a dose-response effect of Ang II (0.001; 0.1 e 10µM) plus insulin (100ng ml-1) and LH (100ng ml-1) was evaluated on steroidogenesis of bovine theca cells. Experiment 3 explored the effects of saralasin (an antagonist of Ang II receptors) on steroid production and steroidogenic enzymes regulation in theca cells. After 24 hours, culture media from experiments 2 and 3 was collected to evaluate testosterone and androstenedione levels by High-Performance Liquid Chromatography. In parallel, mRNA levels of key steroidogenic enzymes (HSD3B2, CYP11A1, CYP17A1) and STAR were assessed by RT-PCR. There was no difference in testosterone and androstenedione production between treated and controls groups, as well as in mRNA levels of the evaluated genes. In conclusion, the results suggest that Ang II does not regulate steroidogenesis in bovine theca cells

Royal Jelly Reduces Melanin Synthesis Through Down-Regulation of Tyrosinase Expression

2011 ◽  
Vol 39 (06) ◽  
pp. 1253-1260 ◽  
Author(s):  
Sang Mi Han ◽  
Joo Hong Yeo ◽  
Yoon Hee Cho ◽  
Sok Cheon Pak
Keyword(s):  
Royal Jelly ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Melanin Synthesis ◽  
Mrna Transcription ◽  
Down Regulation ◽  
Melanin Biosynthesis ◽  
Skin Whitening ◽  
Key Enzyme ◽  
Dose Dependent

For cosmetic reasons, the demand for effective and safe skin-whitening agents is high. Since the key enzyme in the melanin synthetic pathway is tyrosinase, many depigmenting agents in the treatment of hyperpigmentation act as tyrosinase inhibitors. In this study, we have investigated the hypo-pigmentary mechanism of royal jelly in a mouse melanocyte cell line, B16F1. Treatment of B16F1 cells with royal jelly markedly inhibited melanin biosynthesis in a dose-dependent manner. Decreased melanin content occurred through the decrease of tyrosinase activity. The mRNA levels of tyrosinase were also reduced by royal jelly. These results suggest that royal jelly reduces melanin synthesis by down-regulation of tyrosinase mRNA transcription and serves as a new candidate in the design of new skin-whitening or therapeutic agents.

Inhibitory Effect of Tributyltin on Expression of Steroidogenic Enzymes in Mouse Testis

2008 ◽  
Vol 27 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Suel-Kee Kim ◽  
Jong-Hoon Kim ◽  
Jung Ho Han ◽  
Yong-Dal Yoon
Keyword(s):  
Germ Cells ◽  
Leydig Cells ◽  
Serum Testosterone ◽  
Hydroxysteroid Dehydrogenase ◽  
Reproductive Organs ◽  
Inhibitory Effect ◽  
Testicular Development ◽  
Steroidogenic Enzymes ◽  
Hormone Production ◽  
Induced Apoptosis

Tributyltin (TBT) is known to disrupt the development of reproductive organs, thereby reducing fertility. The aim of this study was to evaluate the acute toxicity of TBT on the testicular development and steroid hormone production. Immature (3-week-old) male mice were given a single administration of 25, 50, or 100 mg/kg of TBT by oral gavage. Lumen formation in seminiferous tubule was remarkably delayed, and the number of apoptotic germ cells found inside the tubules was increased in the TBT-exposed animals, whereas no apoptotic signal was observed in interstitial Leydig cells. Reduced serum testosterone concentration and down-regulated expressions of the mRNAs for cholesterol side-chain cleavage enzyme (P450scc), 17α-hydroxylase/C17–20 lyase (P45017α), 3β-hydroxysteroid-dehydrogenase (3β-HSD), and 17β-hydroxysteroid-dehydrogenase (17β-HSD) were also observed after TBT exposure. Altogether, these findings demonstrate that exposure to TBT is associated with induced apoptosis of testicular germ cells and inhibition of steroidogenesis by reduction in the expression of steroidogenic enzymes in interstitial Leydig cells. These adverse effects of TBT would cause serious defects in testicular development and function.

Molecular cloning, expression analysis and developmental changes in ovarian follicles of goose 3β-hydroxysteroid dehydrogenase 1

2014 ◽  
Vol 54 (8) ◽  
pp. 992 ◽  
Author(s):  
Yingying Zhang ◽  
Hehe Liu ◽  
Mingjun Yang ◽  
Shengqiang Hu ◽  
Liang Li ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Follicular Development ◽  
Hydroxysteroid Dehydrogenase ◽  
Ovarian Follicles ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Human And Mouse ◽  
Main Factor

The enzyme 3β-hydroxysteroid dehydrogenase/isomerase1 (3βHSD1) can catalyse the conversion of pregnenolone to progesterone in the △4-3-ketosteroid metabolic pathway. The aim of the present study was to clone 3βHSD1 and to determine whether this enzyme in the follicular wall has an effect on yolk progesterone in geese (Anser cygnoides). A putative coding sequence of 3βHSD1, which was 1134 nucleotides in length, was successfully obtained by using reverse transcription polymerase chain reaction (RT–PCR). A comparison of the deduced amino acid sequence with chicken, quail, zebra finch, cattle, horse, pig, human and mouse 3βHSD1 showed 89.7%, 88.4%, 87.3%, 55.6%, 54.0%, 53.5%, 55.3% and 52.9% similarity, respectively. The detection of 3βHSD1 mRNA levels in several tissues by quantitative real-time PCR showed that the highest level of 3βHSD1 was in the adrenal gland, followed by the ovary, which indicated that the gene we obtained was the adrenal gland/gonad-specific one. We measured the level of 3βHSD1 mRNA in the follicular wall and determined the concentration of progesterone in the yolk of these ovarian follicles; the concentration of progesterone in the yolk had a pattern of expression similar to that of 3βHSD1 in the follicular wall during follicular development. This result suggests that the expression of 3βHSD1 in the follicular wall may be a main factor that contributes to the accumulation of yolk progesterone.

Abstract 239: MicroRNAs hsa-miR-584 and hsa-miR-31 Regulate Expression of Human Angiotensnogen Gene

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Brahmaraju Mopidevi ◽  
Shreekrishna Maharjan ◽  
Sudhir Jain ◽  
Varunkumar G. Pandey ◽  
Ashok Kumar
Keyword(s):  
Luciferase Activity ◽  
Negative Control ◽  
Hek293 Cells ◽  
Multiple Cloning Site ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Hep3b Cells ◽  
Agt Gene ◽  
Dose Dependent ◽  
Mirna Expression Vector

Background: Hypertension is a risk factor for stroke, myocardial infarction, and congestive heart failure. A single nucleotide polymorphism (SNP) (rs7079) in 3’UTR of human angiotensinogen (hAGT) gene is associated with elevated blood pressure. We have used TargetScan V6.0, miRanda miRNA prediction algorithms and found that two microRNAs hsa-miR-584 and hsa-miR-31 may bind differentially to rs7079 and alter the expression of hAGT gene. METHODS: The effect of hsa-miR-584 and hsa-miR-31 miRNAs on endogenous AGT expression levels in Hep3B cells were studied by transfection of individual miRNA mimics followed by quantitative real time PCR (Q-RT-PCR) of the hAGT gene. In addition, the 600 bp 3’UTR of hAGT gene containing either rs7079C or rs7079A was PCR amplified and cloned in to the multiple cloning site of pMIR-REPORT™ miRNA Expression Vector containing luciferase gene. These reporter constructs were then co-transfected with either miRNA mimics or inhibitors to study the effect of miRNAs on luciferase activity in Hep3B cells since these cells express hAGT gene. These experiments were also performed in HEK293 cells which do not express the hAGT gene. Results: Q-RT-PCR showed that hsa-miR-584 and hsa-miR-31 mimics at 50nM concentration reduced endogenous hAGT mRNA levels by 38% and 30% respectively compared to the mock (without any microRNA) or negative control (which does not have any binding site for eukaryotic 3’UTRs) in Hep3B cells. Furthermore hsa-miR-584 and hsa-miR-31 showed 40% and 25% reduced luciferase activity of the construct containing rs7079 C allele. On the other hand these miRNAs did not affect the luciferase activity in the presence of rs7079 A. When dose dependent anti miRNA inhibitors were transfected along with miRNA mimics, these mimics abolished the microRNA induced down-regulation of luciferase activity. Conclusion: hsa-miR-584 and hsa-miR-31 miRNAs bind strongly to the hAGT 3’UTR containing rs7079 C allele as compared to rs7079 A allele and may down regulate the expression of AGT gene containing rs7079 C allele. This may be one of the possible mechanism involved in association of rs7079 A allele with human hypertension.

Abstract 492: Arachidonic Acid Induces Activation of Platelet PF4 and Par-1 mRNA, Which Is Attenuated by Aspirin

2012 ◽  
Vol 32 (suppl_1) ◽  
Author(s):  
Liang Hu ◽  
Michael A Nardi ◽  
Michael Merolla ◽  
Yajaira Suarez ◽  
Jeffrey Berger
Keyword(s):  
Arachidonic Acid ◽  
Platelet Activation ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Thiazole Orange ◽  
Platelet Activity ◽  
Protein Levels ◽  
Reticulated Platelets ◽  
Mrna And Protein Expression ◽  
Dose Dependent

Arachidonic acid (AA) is converted to thromboxane A2 via the cyclooxygenase pathway; however its exact mechanism of platelet activation is uncertain. Inhibition of this pathway via aspirin highlights the importance of this pathway in decreasing thrombotic events. In the present study, we investigate the effect of AA on platelet activity indicators (leukocyte- and monocyte-platelet aggregation [LPA, MPA] and reticulated platelets [RP]), as well as the expression (mRNA and protein) of platelet markers PF4 and Par-1, previously well established platelet transcripts with quantitative determinations. To this end, whole blood was incubated with AA (150mM) for 30 min at room temperature in the absence or presence of aspirin (1mM) prior to addition of antibodies for platelet activity indicators, and isolating platelets for mRNA and protein expression. LPA and MPA were significantly increased after AA stimulation in a dose dependent manner, and were inhibited by aspirin treatment. AA significantly increased PF4 and Par-1 protein level as determined by flow cytometry and western blot assays. Pretreatment with aspirin also attenuated this increase in protein levels. Surprisingly, AA stimulation significantly increased thiazole orange staining (a measure of nucleic acids), another marker of increased platelet activity. Importantly, these results suggest that AA-mediated platelet activation produced an overall increase in platelet total RNA content. To confirm these findings, we analyzed the mRNA expression of PF4 and Par-1 by quantitative real time PCR from platelets treated with AA. Interestingly, AA significantly up-regulated the platelet mRNA transcripts of PF4 and Par-1 by 40% to 60%, and pretreatment with aspirin completely attenuated this effect supporting the specificity of the AA effect on platelet RNA. Altogether, these data suggest that platelet mRNA is affected by AA stimulation, which is attenuated by pretreatment with aspirin. However, the mechanisms responsible for the increased mRNA levels and expression of PF4 and Par-1 (processing of pre-RNA to mRNA) require further investigation. Importantly, our findings provide novel insight regarding platelet activation and a better understanding of mediators in the processes of thrombosis and hemostasis.

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