bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sequence analysis of the turkey LH β subunit and its regulation by gonadotrophin-releasing hormone and prolactin in cultured pituitary cells
Authors: You S , Foster L K , Silsby J L , El Halawani M E , Foster D N 
Published: December 2008

ABSTRACT
cDNAs encoding the precursor molecule of the turkey LH β subunit (tLHβ) were cloned from a turkey pituitary cDNA library. The nucleotide sequence of the longest of two different tLHβ cDNA clones contained 592 bp, and included 23 bp of the 5′ untranslated region (UTR) and 92 bp of the 3′ UTR in addition to a 477 bp open reading frame that encoded a 39 amino acid leader polypeptide and a 120 amino acid mature apoprotein. Turkey and chicken LHβ sequences shared approximately 92 and 93% nucleotide and amino acid sequence similarities respectively. Northern blot analysis of total cellular anterior pituitary RNA showed that an approximate 800 base transcript hybridized to a 32P-labelled tLHβ cDNA probe.
The gonadotrophin-releasing hormone (GnRH)-and prolactin (PRL)-regulated expression of LH and PRL in dispersed pituitary cells was determined by Northern blot analysis of tLHβ and PRL steady-state mRNA levels and by RIA analysis of secreted LH and PRL. GnRH-treated cells showed increased levels of both tLHβ mRNA and secreted LH, whereas mRNA and secreted levels of PRL did not change significantly. Cells treated with PRL showed lower levels of tLHβ and PRL mRNA as well as decreased release of LH and PRL. When cells were treated with both PRL and GnRH, increases in tLHβ mRNA and secreted levels of LH observed with GnRH alone were negated, whereas the decreases in mRNA and secreted levels of PRL observed with PRL alone were abrogated.
These findings suggest that PRL can down-regulate tLHβ gene expression and spontaneous release of LH as well as autoregulate PRL gene expression and spontaneous release of PRL, while GnRH appears capable of modulating the effects of PRL-regulated LH and PRL gene expression and spontaneous release.
Thyroid hormone receptor β mRNA expression in Sertoli cells isolated from prepubertal testis
Authors: Palmero S , De Marco P , Fugassa E 
Published: December 2008

ABSTRACT
A polymerase chain reaction (PCR)-based assay was used to evaluate the expression of thyroid hormone receptor β mRNA in Sertoli cells isolated from both prepubertal rat and piglet testes. The expression of an mRNA coding for the functional thyroid hormone receptor β isoform, as established by the PCR assay, agrees with the presence of specific tri-iodothyronine (T3)-binding sites in the Sertoli cell nuclei of both species, as previously evaluated by displacement analysis. The results ratify the existence of a functional T3 receptor in the prepubertal testis and confirm the Sertoli cell as a specific target for thyroid hormone action on the developing testis. On the other hand, in both peripubertal rat (Palmero et al. 1988; Jannini et al. 1990) and piglet (Palmero et al. 1992) testes, high-affinity, low-capacity T3 binding sites have been specifically localised at the Sertoli cell level and TRal mRNA expression has been detected very recently in immature Sertoli cells (Jannini et al. 1994).
The aim of the present work was to test if, in prepubertal Sertoli cells isolated from both immature rat and piglet testes, the expression of an erbAβ mRNA specifically coding for the TR protein could be detected employing an highly sensitive polymerase chain reaction (PCR)-based assay.
Actions of 3,5,3′-tri-iodothyronine on the synthesis and secretion of major plasma proteins by a human hepatoblastoma cell line (Hep G2)
Authors: Kobayashi M , Horiuchi R 
Published: December 2008

ABSTRACT
We have elucidated the action of tri-iodothyronine (T3) on the synthesis and secretion of seven major plasma proteins in a human hepatoblastoma cell line, Hep G2, and established an in vitro experimental model of human liver cells for the study of the mechanism of the action of thyroid hormone.
Hep G2 cells cultured in serum-free medium were treated with various concentrations of T3. During the first 24 h of T3 treatment, accumulation of α-fetoprotein in the medium was decreased in a dose-dependent manner (10−11-10−8 m), and the inhibitory effect was enhanced during the second 24 h of T3 treatment. On the other hand, α1-antitrypsin accumulation in the medium during the second 24 h of hormone treatment was decreased by T3 (10−9–10−8 m), although no change in accumulation was observed during the first 24 h of T3 treatment.
The newly synthesized [35S]Met-labelled α1-acid glycoprotein was increased by T3 and reached 3·4-fold within 37 h of 10−8 m T3 treatment. The stimulatory effect increased time-dependently (4·6fold after 61 h). In contrast, the synthesis of α-fetoprotein was reduced to half of that of the control after T3 treatment for 37 h.
Although the content of newly synthesized [35S]α1-antitrypsin was not affected by 10−8m T3 treatment during 3 days of hormone treatment, the accumulation of α1-antitrypsin in the medium decreased to 87%; in contrast, total cellular newly synthesized α1-antitrypsin increased to 105–130% of that of the control. From these results, it is suggested that α1-antitrypsin secretion might be suppressed by T3 treatment. However, T3 did not affect the accumulation of albumin, transferrin, fibronectin and α2-macroglobulin in the medium throughout the experiments.
It was shown that T3 has diverse control mechanisms on the synthesis and secretion of plasma proteins in Hep G2 cells: stimulation (α1-acid glycoprotein) or inhibition (α-fetoprotein) of plasma protein synthesis, and inhibition of protein secretion (α1-antitrypsin).
Retinoic acid induces activin receptor IIB mRNA in F9 embryonal carcinoma cells
Authors: Wan Y-J Y , Wang L , Wu T-C J 
Published: December 2008

ABSTRACT
Mouse embryonal carcinoma F9 cells are pluripotent stem cells and differentiate into primitive endodermal cells upon treatment with retinoic acid (RA). We have recently shown that in F9 cells RA regulates gene expression of activin receptor type II (ActR-II), whose ligand is a potent differentiation agent. The present study examined the regulation of the newly cloned activin receptor type IIB (ActR-IIB) gene by RA. F9 cells expressed equal amounts of three ActR-IIB transcripts of 8·0, 7·5 and 4·0 kb. Both 9-cis-RA (c-RA) and all-trans-RA (t-RA) induced ActR-IIB gene expression in a dose-dependent manner. At 10−9m c-RA exerted no effect, while 10−5m c-RA increased the 8·0 kb ActR-IIB transcript about sevenfold. In contrast, t-RA induced the 8·0kb ActR-IIB transcript fivefold at 10−9m and up to eightfold at 10−5m. The inductive effect on the 8·0 kb transcript was greater than that on the 7·5 kb transcript, and was least effective on the 4·0 kb transcript, suggesting that these three mRNA isoforms may originate from different promoters. Both cycloheximide and actinomycin D inhibited the inductive effect of t-RA on ActR-IIB gene expression, in contrast to ActR-II whose gene expression was not suppressed by cycloheximide but abolished by actinomycin D. Thus, endodermal differentiation of F9 cells is associated with activation of ActR-IIB gene and the mechanisms involved in the regulation of ActR-II and IIB gene expression are different.
Structure of two cDNAs encoding cholecystokinin precursors from the brain of Xenopus laevis
Authors: Wechselberger C , Kreil G 
Published: December 2008

ABSTRACT
The skin secretions of many frogs, including Xenopus laevis, contain caerulein, a peptide related to mammalian cholecystokinin. We have screened a cDNA library prepared from the brain of this frog using a cloned cDNA encoding one of the caerulein precursors as a probe. Two clones were isolated which contained inserts encoding cholecystokinin precursors. It was found that the predicted precursor polypeptides resembled their mammalian counterparts rather than the caerulein precursors from the same species. The corresponding mRNAs of different size encoding the Xenopus cholecystokinin precursors are expressed in brain and in the gastrointestinal tract, but not in skin. The smaller mRNA was also detected in lung. These data demonstrate that a polypeptide homologous to mammalian cholecystokinin precursors was present early in the evolution of vertebrates. The possible evolution of the genes encoding the more complex caerulein precursors is discussed.
VITAMIN D DERIVATIVES IN COMBINATION WITH 9-cis RETINOIC ACID PROMOTE ACTIVE CELL DEATH IN BREAST CANCER CELLS
Authors: James S Y , Mackay A G , Colston K W 
Published: December 2008

ABSTRACT
The effects of the novel vitamin D analogue, EB1089 alone, or in combination with the retinoid, 9-cis retinoic acid (9-cis RA) on indices of apoptosis in MCF-7 breast cancer cells have been examined. EB1089 was capable of reducing bcl-2 protein, a suppressor of apoptosis, and increasing p53 protein levels in MCF-7 cell cultures following 96h treatment. In the presence of 9-cis RA, EB1089 acted to further enhance the down-regulation and up-regulation of bcl-2 and p53 respectively.
Furthermore, EB1089 induces DNA fragmentation in MCF-7 cells, a key feature of apoptosis, alone and in combination with 9-cis RA in situ. The observation that EB1089 and 9-cis RA act in a cooperative manner to enhance induction of apoptosis in these cells may have therapeutic implications.
Transcriptional regulation of Na/K-ATPase by corticosteroids, glycyrrhetinic acid and second messenger pathways in rat kidney epithelial cells
Authors: Whorwood C B , Stewart P M 
Published: December 2008

ABSTRACT
Corticosteroid regulation of Na/K-ATPase is of key importance in the modulation of Na+ transport across renal tubular epithelia. In amphibian renal cells, aldosterone induction of Na/K-ATPase α1 and β1 subunit gene transcription is mediated by an indirect mechanism dependent on the synthesis of a labile protein. In mammalian target cells, while both mineralo- and glucocorticoids increase the levels of Na/K-ATPase α1 and β1 subunit mRNA and enzyme activity, they are diminished by glycyrrhetinic acid (GE), the active ingredient of licorice.
To investigate the mechanisms underlying the regulation of mammalian renal Na/K-ATPase, levels of α1 and β1 mRNA were measured in rat kidney epithelial (NRK-52E) cells treated with a range of concentrations of aldosterone, corticosterone and GE in the presence of a specific inhibitor of mRNA synthesis, dichlororibofuranosylbenzimidazole (DRB), an inhibitor of total RNA synthesis, actinomycin D (ActD), and the protein synthesis inhibitor cycloheximide (CHX). In addition, GE was co-incubated with the sodium channel antagonist benzamiloride (BZ). The increase in both α1 and β1 mRNA levels following aldosterone and corticosterone was completely abolished by treatment with ActD and DRB, while CHX did not affect this response. Similarly, the GE-induced decrease in α1 and β1 mRNA was also completely abolished by ActD and DRB, but not by CHX or by BZ. The half-lives of α1 and β1 mRNA in these cells (means±s.e.m., n=4), estimated from the rate of mRNA decay in the presence of DRB, were 6·8±0·3 and 4·8±0·2 h respectively. This was unaffected by GE.
The inhibitory action of GE on α1 and β1 mRNA levels was accompanied by a dose-dependent decrease in levels of intracellular cAMP (means ± s.e.m., n=4) from 395±28 fmol cAMP/μg total cell protein to between 275 ± 19 fmol/μg total cell protein (0·1 μm GE) and 78±11 fmol/μg total cell protein (10 μm GE). This was abolished following down-regulation of protein kinase C by prolonged treatment with the phorbol ester tetradecanoylphorbol-13-acetate (TPA), and by pertussis toxin (PT), but not by cholera toxin (CT). Indeed, subunit mRNA levels were increased by 8-bromo-cAMP (2·2-fold) and stimulators of adenylate cyclase activity, i.e. forskolin (2·1-fold), PT (2·1-fold) and CT (1·9-fold), but not by TPA. In keeping with their effects on GE inhibition of cAMP synthesis, TPA and PT (but not CT) abolished the GE-induced decrease in subunit mRNA.
In conclusion, corticosteroid induction and GE inhibition of Na/K-ATPase subunit gene expression in rat kidney epithelial cells occur at the transcriptional level and do not require de novo synthesis of an intermediary protein. Furthermore, GE attenuation of subunit gene transcription may be mediated by both cAMP-dependent protein kinase A and diacylglycerol—protein kinase C pathways via interaction with a PT-sensitive Gi protein.
Vas deferens epithelial cells in subculture: a model to study androgen regulation of gene expression
Authors: Dassouli A , Darne Ch , Fabre S , Manin M , Veyssière G , Jean Cl 
Published: December 2008

ABSTRACT
The understanding of androgen-regulated gene expression requires a cell culture system that mimics the functions of cells in vivo. In the present paper we have examined a vas deferens epithelial cell subculture system. Cultured vas deferens epithelial cells have been shown to exhibit polarized properties characteristic of functioning epithelia and to display a high level of androgen receptors. Incubation of cells with androgen caused a decrease in cellular androgen receptor mRNA that was time-dependent. Total suppression was observed after 24 h of exposure to androgen. By contrast, incubation of vas deferens epithelial cells with androgen resulted in a threefold increase in the cellular content of androgen receptor protein, as assayed by ligand binding. In response to androgens, vas deferens epithelial cells expressed mouse vas deferens protein mRNA (MVDP mRNA). Maximum expression of the MVDP gene, at both mRNA and protein levels, was observed after 24 h of androgen induction.
DEAE-dextran transfection conditions were defined using the MMTV-CAT vector. Dihydrotestosterone stimulated the transcription activation of MMTV-CAT gene in vas deferens epithelial cells in a dose- and time-dependent manner. No induction was seen when fragments of the MVDP promoter region were cloned directly in front of the CAT gene and transiently transfected into vas deferens epithelial cells. It was found that cotransfection of cells with MVDP-CAT constructs and with an androgen receptor expression vector resulted in a small but consistent androgen-dependent increase in reporter gene activity. Transiently transfected vas deferens epithelial cells are a suitable model with which to study the effect of androgen on gene regulatory elements.
The follicle-stimulating hormone receptor and luteinizing hormone receptor genes are closely linked in sheep and deer
Authors: Montgomery G W , Tate M L , Henry H M , Penty J M , Rohan R M 
Published: December 2008

ABSTRACT
Restriction fragment length polymorphisms were identified in sheep and deer using ovine cDNA probes for the FSH receptor (FSHR) and the LH receptor (LHCGR). FSHR and LHCGR were closely linked in sheep with no recombinants and neither receptor was linked to the Booroola fecundity gene (FecB). Both receptors were also closely linked in deer at a map distance of 3·3 cM. Linkage between the receptor genes assigns FSHR to sheep chromosome 3. Sequence analysis showed that the mammalian LHCGRs and FSHRs are more similar to each other than to mammalian TSH receptor (TSHR). Taken together, these data suggest that TSHR and the LHCGR/FSHR arose from a common ancestral gene by a process of chromosomal duplication. Subsequent duplication of the region containing the LH/FSH receptor and functional divergence could have given rise to the two gonadotrophin receptors present in mammals today.
A thyroid hormone receptor β gene polymorphism associated with Graves’ disease
Authors: Tassi V , Scarnecchia L , Di Cerbo A , Pirro M T , Di Paola R , Liuzzi A , Torlontano M , Zingrillo M , D’Aloiso L , De Filippis V 
Published: December 2008

ABSTRACT
Autoimmune thyroid diseases (AITDs) are clustered in families, but the nature of this clustering is still poorly understood. One possible approach to the identification of genetic factors interacting with the AITDs is the study of the association between polymorphic markers and AITDs themselves. In the present study we have shown an association between an allele of a HindIII restriction fragment length polymorphism (EAβH) intragenic to c-erbAβ, which codes for the thyroid hormone β receptor, and Graves’ disease. This polymorphism can be detected by PCR followed by digestion with the restriction enzyme HindIII. The allelic frequencies were analysed in a panel of DNAs extracted from a population of individuals affected by thyroid disease and originating from southern Italy. A control group (n=120) from the same area was also analysed. The distribution of EAβH alleles was significantly different (P<0·001) in Graves’ disease (n=94) but not in autoimmune thyroiditis (n=60), as compared with controls. Also the distribution of the EAβH genotypes was significantly different in Graves’ patients (P=0·003), as compared with controls, the homozygous state EAβH+/EAβH+ being more frequent in Graves’ patients than in all the other groups. We did not find any association between EAβH genotypes and clinical parameters in Graves’ patients, including eye signs, thyroid volume and level of TSH-binding inhibiting immunoglobulins. Our data support the idea that Graves’ disease is a genetically distinct group within the AITDs.
Cloning and analysis of the cDNA for the common α-subunit of the donkey pituitary glycoprotein hormones
Authors: Chopineau M , Stewart F 
Published: December 2008

ABSTRACT
Reverse transcription-PCR was used to clone the coding region of the donkey (Equus asinus) glycoprotein hormone α-subunit transcript from pituitary gland RNA. The donkey α-subunit sequence demonstrated considerable identity with the horse (97% at the nucleotide level), confirming the very close evolutionary linkage between these two species. The predicted amino acid sequence revealed that the donkey α-subunit has the same unusual C-terminus as the horse α-subunit, when compared with all other mammalian α-subunits, including a Tyr-His transposition between positions 87 and 93 and Ile instead of Ser as the C-terminal residue. Since recent evidence indicates important involvement of this region of the α-subunit in receptor binding, these findings provide a possible partial explanation for the unique biological properties of the equine gonadotrophins.
Cloning of rabbit prolactin cDNA and prolactin gene expression in the rabbit mammary gland
Authors: Gabou L , Boisnard M , Gourdou I , Jammes H , Dulor J-P , Djiane J 
Published: December 2008

ABSTRACT
cDNA clones coding for rabbit prolactin were isolated from a pituitary library using a rat prolactin RNA probe. One cDNA contained 873 bases including the entire coding sequence of rabbit prolactin, its signal peptide and the 5′ and 3′ untranslated regions of 44 and 145 nucleotides respectively. The deduced amino acid sequence of the cloned prolactin cDNA presented a 93–78% identity with mink, porcine and human prolactins. The prolactin gene transcription was investigated by RT-PCR analysis in several organs of midlactating New Zealand White rabbits. The ectopic transcription of the prolactin gene was examined in more detail in the mammary gland. A strong PCR signal was detected in the mammary gland of virgin does and was also observed during pregnancy and at the beginning of lactation. This PCR signal was very weak in mid-lactating and absent in post-weaning mammary gland.
Angiotensin II stimulation of the basolateral located Na+/H+ antiporter in eel (Anguilla anguilla) enterocytes
Authors: Vilella S , Zonno V , Marsigliante S , Ingrosso L , Muscella A , Ho M M , Vinson G P , Storelli C 
Published: December 2008

ABSTRACT
The pH-sensitive fluorescent dye, 2′,7′-bis-carboxy-ethyl-5,6-carboxyfluorescein acetoxymethyl ester, was used to examine the effects of fish or human angiotensin II (Ang II) on the activity of the basolateral located Na+/H+ antiporter in eel intestinal cell suspensions. Exposure of eel enterocytes to either hormone led to an increased activity of the antiporter. This time- and dose-dependent stimulatory effect was inhibited by the specific antiporter inhibitor dimethylamiloride (DMA).
Preincubation with a monoclonal antibody (6313/G2), directed against the N-terminal extracellular domain of the mammalian AT1 Ang II receptor, prevented the stimulatory effect of the hormone and inhibited the binding of [3,5-3H]Tyr4-Ile5-Ang II to intestinal cell suspensions, suggesting specific binding of the antibody to the eel Ang II receptor. The results indicate that both fish and human Ang II stimulate the DMA-sensitive Na+/H+ antiporter present in eel intestinal cells by means of a mammalian AT1-like receptor.
In vitro pituitary GH secretion after GHRH, forskolin, dibutyryl cyclic-adenosine 3′,5′-monophosphate and phorbol 12-myristate 13-acetate stimulation in long-term orchidectomized rats
Authors: Tena-Sempere M , Pinilla L , Aguilar E 
Published: December 2008

ABSTRACT
In the present work in vitro GH pituitary responsiveness to GHRH in short-term (STO) and long-term orchidectomized (LTO) male rats was compared. In agreement with previous data obtained in vivo, pituitaries from STO rats showed reduced GH release after GHRH stimulation while LTO male pituitaries presented responses similar to those from control animals after maximal GHRH (10-6 m) stimulation. This suggests that compensatory mechanisms have taken place, probably at the pituitary level, in order to restore GH pituitary responsiveness to high doses of GHRH. However, LTO male rats showed a reduced sensitivity to GHRH relative to intact males, as indicated by a higher EC50 vs controls (40·82 ± 12·03 nm vs 0·35 ± 0·09 nm in intact males). We aimed to investigate further the events involved in the compensatory mechanisms that take place in LTO rats. For this purpose, we compared in vitro GH secretion by pituitaries from intact and LTO male rats after stimulation with specific activators of the signal transduction pathways related to GH release. Forskolin and dibutyryl cyclic-adenosine 3′,5′-monophosphate were more effective in eliciting GH secretion (expressed in terms of percent increment over basal GH release) in LTO males, whereas phorbol 12-myristate 13-acetate was completely ineffective in stimulating GH release in this group. Thus, our results clearly showed that long-term orchidectomy enhances the effectiveness of the cAMP pathway in inducing GH release while it completely blunts that of the protein kinase C pathway. In conclusion, orchidectomy decreased the effectiveness of GHRH in eliciting GH release in vitro. However, long-term orchidectomy activated compensatory mechanisms that restored complete GH pituitary responsiveness to maximal GHRH stimulation. These mechanisms seem not to operate in STO rats. An increased effectiveness of the cAMP pathway in eliciting GH release in LTO rats is probably involved in the aforementioned compensatory mechanisms.
Negative regulatory domains in a trophoblast interferon promoter
Authors: Guesdon F M J , Stewart H J , Flint A P F 
Published: December 2008

ABSTRACT
A bovine trophoblast interferon (IFN-τ) gene promoter sequence (− 450 to +26 bp relative to the transcription start site) led to expression of reporter gene (CAT) constructs transfected into L929 (murine fibroblast) or JAR (human choriocarcinoma) cells. Expression depended on the presence of an exogenous (SV40) enhancer. Poly(I)(C) activated endogenous IFN production in L929 and JAR cells but had no consistent effect on CAT expression. Similar results were obtained in L929 cells with inactivated Newcastle disease virus. There was no 'priming' effect of exogenous Type I IFN. Deletion mutants revealed sites exerting negative control on expression between −338 and −247 bp, and between −150 and −71 bp; these regions contained sequences resembling previously identified negative regulatory domains. In the absence of viral inducibility it is proposed that negative regulation contributes towards the stringent control of expression characteristic of IFN-τ genes.