scholarly journals Comparison of different forms of dietary selenium supplementation on gene expression of cytoplasmic thioredoxin reductase, selenoprotein P, and selenoprotein W in broilers             

2014 ◽  
Vol 59 (No. 12) ◽  
pp. 571-578 ◽  
Author(s):  
X.A. Zhan ◽  
H.F. Wang ◽  
D. Yuan ◽  
Y.X. Wang ◽  
F. Zhu

Effects of different forms of dietary selenium (Se) supplementation on gene expression of cytoplasmic thioredoxin reductase (TrxR1), selenoprotein P (SelP), and selenoprotein W (SelW) in broilers were investigated. A total of six hundred Ross 308 broilers (1-day-old) with similar body weight were randomly divided into three groups, each of which included 5 replicates of 40 birds. These three treatments received the same basal diet with only background Se level of 0.04 mg Se/kg, supplemented with 0.15 mg Se/kg as sodium selenite (SS) or l-selenomethionine (l-Se-Met) or d-selenomethionine (d-Se-Met) for 42 days. The SS supplemented diet increased TrxR1 activity in liver (P < 0.01) and kidney (P < 0.01) as well as SelP concentration in serum (P < 0.05) and liver (P < 0.01) more than the d-Se-Met supplemented diet. The addition of SS also highly increased liver (P < 0.01) and kidney (P < 0.01) TrxR1 activities of broilers in comparison with broilers fed l-Se-Met diet. In addition, liver TrxR1 activity in l-Se-Met group was higher than that in d-Se-Met group (P < 0.05). Liver and kidney mRNA levels of TrxR1 and SelP as well as breast muscle SelW mRNA level were significantly increased by l- and d-Se-Met supplementation in comparison with SS supplementation (P < 0.01), while the d-Se-Met group showed more effective (P < 0.01) than the l-Se-Met group in increasing the mRNA levels of TrxR1 and SelP in liver and kidney. Therefore, dietary l-Se-Met and d-Se-Met supplementation could improve mRNA levels of different selenoproteins studied and reduce amounts of TrxR1 and SelP in broilers compared with SS. Besides, l-Se-Met is more effective than d-Se-Met in raising TrxR1 activity and decreasing mRNA abundance of TrxR1 and SelP in broilers.  

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 107-108
Author(s):  
Andrew D Magnuson ◽  
Xingen Lei

Abstract Enrichment of docosahexaenoic-acid (DHA) into eggs of laying-hens may be limited by the availability phospholipids as a deposition sink. The present study was to determine if dietary supplementations of phospholipid-component molecules or synthesis-enhancers: choline, serine, and ethanolamine could elevate phospholipid and DHA enrichment in the eggs and tissues of hens. A total of 50-White-Leghorn-Shavers (42-wk old) were individually caged and divided into 5 groups (n = 10/group). The 5 groups of hens were fed the following diets for 3 wk: Diet-1 = a corn soybean-meal basal-diet, Diet-2 = Diet-1 + 4%-microalgae (Aurantiochytrium, Heliae, Gibert, AZ, 1.81 g-DHA/kg) + choline-chloride (26.3 g/kg diet, 60% purity, DSM-Co., Basel, Switzerland), Diet-3 = Diet-2 + 1.41% of L-serine (100% purity, Ajinomoto-Co., Inc., Kawasaki, Japan), Diet-4 = Diet-2 + 100 mg of ethanolamine/kg (99% purity, Sigma-Aldirch-Co., St Loius, MO), and Diet-5 = Diet-3 + 100 mg of ethanolamine/kg. At the end of study, eggs, liver, ovary, and adipose samples were collected from 6 hens/group for biochemical analysis. Data were analyzed by one-way ANOVA. Compared with Diet-1, Diet-2 enhanced (P < 0.05) DHA concentrations in egg yolk and liver by 213 mg/egg and 2.98 mg/g tissue, respectively, but decreased (P < 0.05) total phospholipid-concentrations of yolk and liver by 50%, and hepatic-mRNA levels of elongases-2/5 and desaturases-4/6 by 25–50%. Compared with Diet-2, Diet-5 enhanced (P < 0.05) DHA (by 20%) and phospholipid (by 40%) concentrations in the egg yolk, and upregulated (P < 0.05) lipid-metabolism genes involved in the citicoline (CDP, up-to-3-fold) and CDP-ethanolamine (up-to-2.5-fold) pathways in the liver and ovary-tissue. In comparison, Diets-3 and 4 resulted in only 3–11% higher (P < 0.05) DHA-concentrations in the liver over Diet-2. In conclusion, feeding hens a high DHA and choline diet enriched DHA in the egg yolk and down-regulated lipogenesis-gene-expression in the tissues. Supplementing the diet with extra-serine and ethanolamine further-enhanced the DHA enrichment in the egg yolk and restored the high DHA-mediated changes in the gene-expression. (Supported in part by DOE-MAGIC-grant DE-EE0007091, USDA-grant 2019-69012-29905, and Cornell-University-Hatch-grants NYC-127419/127302).


2011 ◽  
Vol 143 (3) ◽  
pp. 1516-1523 ◽  
Author(s):  
Bo Sun ◽  
Rihua Wang ◽  
Jinlong Li ◽  
Zhihui Jiang ◽  
Shiwen Xu

1997 ◽  
Vol 82 (7) ◽  
pp. 2210-2214
Author(s):  
Catarina Bjelfman ◽  
Torbjörn G. Söderström ◽  
Einar Brekkan ◽  
Bo Johan Norlén ◽  
Lars Egevad ◽  
...  

Androgens are implicated in the development of prostate cancer (CAP) and benign prostate hyperplasia. The conversion of testosterone to the more potent metabolite dihydrotestosterone by prostate-specific steroid 5α-reductase type 2 (5α-red2) is a key mechanism in the action of androgens in the prostate and is important in the promotion and progression of prostate diseases. Manipulation of the turnover of androgens is thus fundamental in the pharmacological treatment strategy. We have developed a sensitive solution hybridization method for quantification of the gene expression of 5α-red2 in core needle biopsies of the prostate. The 5α-red2-specific messenger RNA (mRNA) levels were measured in 50 human prostate transrectal ultrasound-guided core biopsies obtained from 31 outpatients (median age 72, range 57–88 yr) undergoing biopsy for diagnostic purposes. Significant differences were observed in the gene expression of 5α-red2 between cancerous and noncancerous tissue. In the 14 biopsies judged cancerous, the median 5α-red mRNA levels were 3.5 amol/ng total RNA compared with 12.0 amol/ng total RNA in the biopsies showing no cancer (P = 0.0018). The median 5α-red2 mRNA level in noncancerous tissue was thus 3.4 times higher than in the cancerous specimens.


2002 ◽  
Vol 69 (1) ◽  
pp. 13-26 ◽  
Author(s):  
AURORE RINCHEV-ALARNOLD ◽  
LUCETTE BELAIR ◽  
JEAN DJIANE

Secretory IgA found in external secretions are constituted by polymeric IgA (pIgA) bound to the extra-cellular part of the polymeric immunoglobulin receptor (pIgR). The receptor mediates transcytosis of pIgA across epithelial cells. The aim of the present study was to analyse the evolution of pIgR expression in the sheep mammary gland during the development of the mammary gland and to analyse its hormonal regulation. Gene expression of the pIgR was analysed in sheep mammary gland during pregnancy and lactation. By Northern Blot analysis, we observed that low levels of pIgR mRNA are expressed until day 70 of pregnancy. Accumulation of pIgR mRNA started during the third part of pregnancy and intensified 3 d after parturition to reach highest levels during established lactation (day 70). In situ hybridization analysis was used to confirm the increase in pIgR gene expression per mammary epithelial cell. In order to examine the hormonal regulation of the pIgR expression, virgin ewes were hormonally treated. Treatment with oestradiol and progesterone increased pIgR mRNA levels slightly. Subsequent addition of glucocorticoids induced a significant accumulation of pIgR mRNA in the mammary gland of the treated animals. Immunohistochemical analysis was performed to verify that the increase of pIgR mRNA level was associated with enhancement of the pIgR protein in mammary cells. No increase of pIgR mRNA levels were observed if PRL secretion was blocked by bromocryptine injections throughout the hormonal procedure. In conclusion, the present experiments suggest that the enhancement of pIgR levels during lactation result from combined effects of both prolactin and glucocorticoids.


1997 ◽  
Vol 326 (1) ◽  
pp. 167-172 ◽  
Author(s):  
Jiaxin CAI ◽  
Zong-Zhi HUANG ◽  
Shelly C. LU

γ-Glutamylcysteine synthetase (GCS) is the rate-limiting enzyme in the biosynthesis of glutathione and is composed of a heavy and a light subunit. Although the heavy subunit is enzymically active alone, the light subunit plays an important regulatory role by making the holoenzyme function more efficiently. In the current study we examined whether conditions which are known to influence gene expression of the heavy subunit also influence that of the light subunit, and the mechanisms involved. Treatment of cultured rat hepatocytes with hormones such as insulin and hydrocortisone, or plating hepatocytes under low cell density increased the steady-state mRNA level of the heavy subunit only. Treatment with diethyl maleate (DEM), buthionine sulphoximine (BSO) and t-butylhydroquinone (TBH) increased the steady state mRNA level and gene transcription rates of both subunits. These treatments share in common their ability to induce oxidative stress and activate nuclear factor κB (NF-κB). Treatment with protease inhibitors 7-amino-1-chloro-3-tosylamido-2-heptanone (TLCK) or L-1-tosylamido-2-phenylethyl chloromethyl ketone (TPCK) had no influence on the basal NF-κB and GCS subunit mRNA levels, but blocked the activation of NF-κB by DEM, BSO and TBH, and the increase in GCS heavy subunit mRNA level by BSO and TBH. On the other hand, the DEM-, BSO- and TBH-induced increase in GCS light-subunit mRNA level was unaffected by TLCK and TPCK. Thus only the heavy subunit is hormonally regulated and growth sensitive, whereas both subunits are regulated by oxidative stress. Signalling through NF-κB is involved only in the oxidative-stress-mediated changes in the heavy subunit gene expression.


PPAR Research ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Lijun Zhang ◽  
Chunyan Li ◽  
Fang Wang ◽  
Shenghua Zhou ◽  
Mingjun Shangguan ◽  
...  

PPARαagonist clofibrate reduces cholesterol and fatty acid concentrations in rodent liver by an inhibition of SREBP-dependent gene expression. In present study we investigated the regulation mechanisms of the triglyceride- and cholesterol-lowering effect of the PPARαagonist clofibrate in broiler chickens. We observed that PPARαagonist clofibrate decreases the mRNA and protein levels of LXRαand the mRNA and both precursor and nuclear protein levels of SREBP1 and SREBP2 as well as the mRNA levels of the SREBP1 (FASNandGPAM) and SREBP2 (HMGCRandLDLR) target genes in the liver of treated broiler chickens compared to control group, whereas the mRNA level ofINSIG2, which inhibits SREBP activation, was increased in the liver of treated broiler chickens compared to control group. Taken together, the effects of PPARαagonist clofibrate on lipid metabolism in liver of broiler chickens involve inhibiting transcription and activation of SREBPs and SREBP-dependent lipogenic and cholesterologenic gene expression, thereby resulting in a reduction of the triglyceride and cholesterol levels in liver of broiler chickens.


2011 ◽  
Vol 210 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Petra Popovics ◽  
Zoltan Rekasi ◽  
Alan J Stewart ◽  
Magdolna Kovacs

Pituitary inhibin B, activin B, and follistatin are local regulators of FSH. Activin B is a homodimeric molecule (βB–βB), while inhibin B contains an α and a βB subunit. The regulation of gene expression of α, βB, and follistatin by local and endocrine hormones was examined in pituitaries from female rats and in perifused pituitary cells by RT-PCR. Ovariectomy (OVX) induced an elevation in the mRNA level of α and βB subunits and follistatin. Short-term (4 h) treatment of pituitary cells with GnRH decreased both the inhibin α and the inhibin/activin βB subunit mRNA levels, while long-term treatment (20 h) with 100 nM GnRH stimulated the expression of both subunits. In contrast, the mRNA level of follistatin was elevated after the short-term GnRH treatment. Long-term exposure of pituitary cells to estradiol and inhibin B suppressed the mRNA expression of βB and had no effect on the expression of α subunit and follistatin. Our results demonstrate that the increased expressions of inhibin/activin subunits and follistatin in the post-OVX period can be induced by the lack of gonadal negative feedback, resulting in a high GnRH environment in the pituitary. This study reports for the first time that GnRH administered in high doses and for a long period stimulates the gene expression of inhibin/activin subunits and thereby may contribute to the stimulatory effect of OVX on the expression of these genes.


1992 ◽  
Vol 70 (10-11) ◽  
pp. 1238-1248 ◽  
Author(s):  
Normand Marceau ◽  
Andrée Grenier ◽  
Micheline Noel ◽  
Donald Mailhot ◽  
Anne Loranger

Intermediate filaments of rat hepatocytes are composed of cytokeratins 8 and 18 (CK8 and CK18, respectively). Recent work from our laboratory has indicated a close relationship between the synthesis of these cytokeratins, their organization into intermediate filaments, and the promotion of growth and differentiation of cultured rat hepatocytes by insulin, epidermal growth factor, and dexamethasone. In the present study, we examined the mRNA expression, level of protein synthesis, and fibrillar distribution of cytokeratins 8 and 18 and actin in hepatocytes, isolated from normal and dexamethasone-injected rats and cultured as monolayers or spheroids in the presence of insulin, or from normal rat hepatocytes, cultured as monolayers in the presence of dexamethasone, insulin, and dimethyl sulfoxide. The CK8 mRNA level was lower in hepatocytes isolated from noninjected rats and cultured as either monolayers or spheroids, than in those from dexamethasone-injected rats. However, the CK18 mRNA level varied in a manner that was different from that of CK8 mRNA, showing that the modes of expression of the two genes were independent. The various changes in hepatocyte culture conditions led to variations in albumin mRNA levels that largely followed those observed in CK8 mRNA levels. In the case of actin, the amount of mRNAs varied from relatively high levels in hepatocyte monolayers to extremely low levels in hepatocyte spheroids, even though in both cases the cells were isolated from dexamethasone-injected rats. These changes in mRNA levels did not necessarily correlate with changes in the synthesis of cytokeratins 8 and 18, and actin. Changes in culture conditions induced a major reorganization in the distribution of cytokeratin intermediate filaments and actin filament between the region near the surface membrane and the cytoplasm. The most divergent patterns in cytokeratin intermediate filaments and actin filament distributions were observed between hepatocytes cultured as spheroidal aggregates and as monolayers in the presence of dimethyl sulfoxide. The former condition resulted in patterns of cytokeratin and actin gene expression and fibrillar organization that best matched those in situ. In the latter condition, inappropriate patterns were obtained, in spite of the fact that dimethyl sulfoxide treated hepatocytes are known to exhibit survival and functional activities equivalent to that of hepatocyte spheroids. These results demonstrate for the first time that the survival and functional activity (i.e., albumin production) of rat hepatocytes in vitro is not necessarily correlated with a particular pattern of cytokeratin and actin gene expression and fibrillar arrangement.Key words: gene expression, cytokeratins, intermediate filaments, cytoskeleton, hepatocytes.


2000 ◽  
Vol 20 (3) ◽  
pp. 805-815 ◽  
Author(s):  
Yidong Bai ◽  
Rebecca M. Shakeley ◽  
Giuseppe Attardi

ABSTRACT A mouse cell variant carrying in heteroplasmic form a nonsense mutation in the mitochondrial DNA-encoded ND5 subunit of the respiratory NADH dehydrogenase has been isolated and characterized. The derivation from this mutant of a large number of cell lines containing between 4 and 100% of the normal number of wild-type ND5 genes has allowed an analysis of the genetic and functional thresholds operating in mouse mitochondria. In wild-type cells, ∼40% of the ND5 mRNA level was in excess of that required for ND5 subunit synthesis. However, in heteroplasmic cells, the functional mRNA level decreased in proportion to the number of wild-type ND5 genes over a 25-fold range, pointing to the lack of any compensatory increase in rate of transcription and/or stability of mRNA. Most strikingly, the highest ND5 synthesis rate was just sufficient to support the maximum NADH dehydrogenase-dependent respiration rate, with no upregulation of translation occurring with decreasing wild-type mRNA levels. These results indicate that, despite the large excess of genetic potential of the mammalian mitochondrial genome, respiration is tightly regulated by ND5 gene expression.


2007 ◽  
Vol 31 (2) ◽  
pp. 306-314 ◽  
Author(s):  
Yih-Shou Hsieh ◽  
Shun-Fa Yang ◽  
Shu-Chen Chu ◽  
Dong-Yih Kuo

Neuropeptide Y (NPY) is an appetite-controlling neuromodulator that contributes to the appetite-suppressing effect of phenylpropanolamine (PPA). Aims of this study were to investigate whether protein kinase A (PKA) signaling is involved in regulating NPY gene expression and PPA-induced anorexia. Rats were given daily with PPA for 5 days. Changes in daily food intake and hypothalamic NPY, PKA, cAMP response element binding protein (CREB), and pro-opiomelanocortin (POMC) gene expression were measured and compared. To further determine if PKA was involved, intracerebroventricular infusions of antisense oligodeoxynucleotide were performed at 60 min before daily PPA treatment in freely moving rats. Results showed that daily PKA, CREB, and POMC expression were increased following PPA treatment, which showed a closely reverse relationship with alterations of decreased feeding behaviors and NPY mRNA levels. Results also showed that PKA knock-down could block PPA-induced anorexia as well as restore NPY mRNA level, indicating the involvement of PKA signaling in the regulation of NPY gene expression. It is suggested that hypothalamic PKA signaling may participate in the central regulation of PPA-mediated appetite suppression via the modulation of hypothalamic NPY gene expression. The present findings reveal that manipulations at the molecular level of PKA or cAMP may allow the development of therapeutic agents to improve the undesirable properties of PPA or other amphetamine-like anorectic drugs.


Sign in / Sign up

Export Citation Format

Share Document