Sox9-dependent transcriptional regulation of the proprotein convertase furin

2007 ◽  
Vol 293 (1) ◽  
pp. C172-C183 ◽  
Author(s):  
Philippe Guimont ◽  
Francine Grondin ◽  
Claire M. Dubois
Keyword(s):  
High Mobility ◽  
Inhibitory Effect ◽  
Nodule Formation ◽  
Mrna Levels ◽  
Paracrine Factor ◽  
Proprotein Convertase ◽  
Hmg Box ◽  
Repressive Effect

The proprotein convertase furin participates in the maturation/bioactivation of a variety of proproteins involved in chondrogenesis events. These include parathyroid hormone-related peptide (PTHrP), an autocrine/paracrine factor that is crucial to both normal cartilage development and cartilage-related pathological processes. Despite the known importance of furin activity in the bioactivation of the polypeptides, the mechanisms that control furin regulation in chondrogenesis remain unknown. To gain insight into the molecular regulation of furin, we used the mouse prechondrogenic ATDC5 cell line, an established in vitro model of cartilage differentiation. Peak expression of both furin mRNA and furin PTHrP maturation was observed during chondrocyte nodule formation stage, an event that correlated with increased mRNA levels of Sox9, a potent high-mobility-group (HMG) box-containing transcription factor required for cartilage formation. Inhibition of furin activity led to a diminution in maturation of PTHrP, suggesting a relationship between Sox9-induced regulation of furin and chondrogenesis events. Transient transfection of Sox9 in nonchondrogenic cells resulted in a marked increase in furin mRNA and in the transactivation of the furin P1A promoter. Direct Sox9 action on the P1A promoter was narrowed down to a critical paired site with Sox9 binding capability in vitro and in vivo. Sox9 transactivation effect was inhibited by L-Sox5 and Sox-6, two Sox9 homologs also expressed in ATDC5 cells. Sox6 inhibitory effect was reduced when using Sox6-HMG-box mutants, indicating a repressive effect through direct HMG-box/DNA binding. Our work suggests a mechanism by which furin is regulated during chondrogenesis. It also adds to the complexity of Sox molecule interaction during gene regulation.

scholarly journals A Potential Role of Progestin-Induced Laminin-5/α6-Integrin Signaling in the Formation of Side Branches in the Mammary Gland

Endocrinology ◽  
2012 ◽  
Vol 153 (10) ◽  
pp. 4990-5001 ◽  
Author(s):  
Gabriele Meyer ◽  
Jeffrey Leipprandt ◽  
Jianwei Xie ◽  
Mark D. Aupperlee ◽  
Sandra Z. Haslam
Keyword(s):  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Nuclear Factor Κb ◽  
Inhibitory Effect ◽  
Collagen Gels ◽  
Paracrine Factor ◽  
Laminin 5 ◽  
Adult Mice

Abstract Mammary organoids from adult mice produce tubules, analogous to mammary ducts in vivo, in response to hepatocyte growth factor (HGF) when cultured in collagen gels. The combination of HGF plus progestin (R5020) causes reduced tubule number and length. We hypothesized that the inhibitory effect on tubulogenesis was due to progestin-mediated alteration of HGF/c-Met signaling. Using molecular inhibitors and short hairpin RNA, it was determined that HGF activation of Ras-related C3 botulinum toxin substrate (Rac1) was required for the formation of cytoplasmic extensions, the first step of tubulogenesis, and that Rac1 activity was Src kinase (Src) and focal adhesion kinase (FAK) dependent. The highly novel finding was that R5020 reduced tubulogenesis by up-regulating and increasing extracellular laminin and α6-integrin ligation to reduce activation of the Src, focal adhesion kinase, and Rac1 pathway. Receptor activator of nuclear factor-κB ligand, another progesterone-induced paracrine factor, did not replicate this effect of R5020. The inhibitory effect of R5020 on tubulogenesis was likely mediated through progesterone receptor (PR) isoform A (PRA), because PRA is the predominant PR isoform expressed in the organoids, and the progestin-induced effect was prevented by the PR antagonist RU486. These results provide a plausible mechanism that explains progestin/PRA-mediated blunting of HGF-induced tubulogenesis in vitro and is proposed to be relevant to progesterone/PRA-induced side-branching in vivo during pregnancy.

scholarly journals Functional analyses of the Neurospora crassa MT a-1 mating type polypeptide.

Genetics ◽  
1994 ◽  
Vol 137 (3) ◽  
pp. 715-722 ◽  
Author(s):  
M L Philley ◽  
C Staben
Keyword(s):  
Dna Binding ◽  
Neurospora Crassa ◽  
Mating Type ◽  
Dna Sequences ◽  
High Mobility ◽  
Binding Motif ◽  
Vegetative Incompatibility ◽  
Hmg Box

Abstract The Neurospora crassa mt a-1 gene, encoding the MT a-1 polypeptide, determines a mating type properties: sexual compatibility and vegetative incompatibility with A mating type. We characterized in vivo and in vitro functions of the MT a-1 polypeptide and specific mutant derivatives. MT a-1 polypeptide produced in Escherichia coli bound to specific DNA sequences whose core was 5'-CTTTG-3'. DNA binding was a function of the MT a-1 HMG box domain (a DNA binding motif found in high mobility group proteins and a diverse set of regulatory proteins). Mutation within the HMG box eliminated DNA binding in vitro and eliminated mating in vivo, but did not interfere with vegetative incompatibility function in vivo. Conversely, deletion of amino acids 216-220 of MT a-1 eliminated vegetative incompatibility, but did not affect mating or DNA binding. Deletion of the carboxyl terminal half of MT a-1 eliminated both mating and vegetative incompatibility in vivo, but not DNA binding in vitro. These results suggest that mating depends upon the ability of MT a-1 polypeptide to bind to, and presumably to regulate the activity of, specific DNA sequences. However, the separation of vegetative incompatibility from both mating and DNA binding indicates that vegetative incompatibility functions by a biochemically distinct mechanism.

scholarly journals Obestatin Plays an Opposite Role in the Regulation of Pituitary Somatotrope and Corticotrope Function in Female Primates and Male/Female Mice

Endocrinology ◽  
2014 ◽  
Vol 155 (4) ◽  
pp. 1407-1417 ◽  
Author(s):  
Raúl M. Luque ◽  
José Córdoba-Chacón ◽  
Alejandro Ibáñez-Costa ◽  
Iacopo Gesmundo ◽  
Cristina Grande ◽  
...  
Keyword(s):  
Hormone Secretion ◽  
Somatostatin Receptors ◽  
Inhibitory Effect ◽  
Pituitary Function ◽  
Pituitary Hormone ◽  
Mrna Levels ◽  
Ghrh Receptor ◽  
Acth Release

Obestatin is a 23-amino-acid amidated peptide that is encoded by the ghrelin gene. Previous studies have shown obestatin can modulate the hypothalamic neuronal circuitry that regulates pituitary function, perhaps by modulating the actions of ghrelin. However, the direct actions of obestatin on pituitary function remain controversial. Here, primary pituitary cell cultures from a nonhuman primate (baboon) and mice were used to test the effects of obestatin on pituitary hormone expression and secretion. In pituitary cultures from both species, obestatin had no effect on prolactin, LH, FSH, or TSH expression/release. Conversely, obestatin stimulated proopiomelanocortin expression and ACTH release and inhibited GH expression/release in vitro, actions that were also observed in vivo in mice treated with obestatin. In vitro, obestatin inhibited the stimulatory actions of ghrelin on GH but not ACTH release. The inhibitory effect of obestatin on somatotrope function was associated with an overall reduction in pituitary transcription factor-1 and GHRH receptor mRNA levels in vitro and in vivo as well as a reduction in hypothalamic GHRH and ghrelin expression in vivo. The stimulatory effect of obestatin on ACTH was associated with an increase in pituitary CRF receptors. Obestatin also reduced the expression of pituitary somatostatin receptors (sst1/sst2), which could serve to modify its impact on hormone secretion. The in vitro actions of obestatin on both GH and ACTH release required the adenylyl cyclase and MAPK routes. Taken together, our results provide evidence that obestatin can act directly at the pituitary to control somatotrope and corticotrope function, and these effects are conserved across species.

scholarly journals Effect of Lipopolysaccharide and TNFα on Neuronal Ascorbic Acid Uptake

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Veedamali S. Subramanian ◽  
Trevor Teafatiller ◽  
Anshu Agrawal ◽  
Masashi Kitazawa ◽  
Jonathan S. Marchant
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Inhibitory Effect ◽  
Acid Uptake ◽  
Mrna Levels ◽  
The Central Nervous System ◽  
Factor Α ◽  
And Function

Vitamin C (ascorbic acid: AA) uptake in neurons occurs via the sodium-dependent vitamin C transporter-2 (SVCT2), which is highly expressed in the central nervous system (CNS). During chronic neuroinflammation or infection, CNS levels of lipopolysaccharide (LPS) and LPS-induced tumor necrosis factor-α (TNFα) are increased. Elevated levels of LPS and TNFα have been associated with neurodegenerative diseases together with reduced levels of AA. However, little is known about the impacts of LPS and TNFα on neuronal AA uptake. The objective of this study was to examine the effect of LPS and TNFα on SVCT2 expression and function using in vitro and in vivo approaches. Treatment of SH-SY5Y cells with either LPS or TNFα inhibited AA uptake. This reduced uptake was associated with a significant decrease in SVCT2 protein and mRNA levels. In vivo exposure to LPS or TNFα also decreased SVCT2 protein and mRNA levels in mouse brains. Both LPS and TNFα decreased SLC23A2 promoter activity. Further, the inhibitory effect of LPS on a minimal SLC23A2 promoter was attenuated when either the binding site for the transcription factor Sp1 was mutated or cells were treated with the NF-κB inhibitor, celastrol. We conclude that inflammatory signals suppress AA uptake by impairing SLC23A2 transcription through opposing regulation of Sp1 and NF-κB factors.

scholarly journals TbKAP6, a Mitochondrial HMG Box-Containing Protein in Trypanosoma brucei, Is the First Trypanosomatid Kinetoplast-Associated Protein Essential for Kinetoplast DNA Replication and Maintenance

2014 ◽  
Vol 13 (7) ◽  
pp. 919-932 ◽  
Author(s):  
Jianyang Wang ◽  
Valeria Pappas-Brown ◽  
Paul T. Englund ◽  
Robert E. Jensen
Keyword(s):  
Trypanosoma Brucei ◽  
Mammalian Cells ◽  
High Mobility ◽  
Kinetoplast Dna ◽  
Content Type ◽  
Hmg Box ◽  
Mitochondrial Nucleoids ◽  
Topo Ii

ABSTRACT Kinetoplast DNA (kDNA), the mitochondrial genome of trypanosomatids, is a giant planar network of catenated minicircles and maxicircles. In vivo kDNA is organized as a highly condensed nucleoprotein disk. So far, in Trypanosoma brucei , proteins involved in the maintenance of the kDNA condensed structure remain poorly characterized. In Crithidia fasciculata , some small basic histone H1-like k inetoplast- a ssociated p roteins (CfKAP) have been shown to condense isolated kDNA networks in vitro . High-mobility group (HMG) box-containing proteins, such as mitochondrial transcription factor A (TFAM) in mammalian cells and Abf2 in the budding yeast, have been shown essential for the packaging of mitochondrial DNA (mtDNA) into mitochondrial nucleoids, remodeling of mitochondrial nucleoids, gene expression, and maintenance of mtDNA. Here, we report that TbKAP6, a mitochondrial HMG box-containing protein, is essential for parasite cell viability and involved in kDNA replication and maintenance. The RNA interference (RNAi) depletion of TbKAP6 stopped cell growth. Replication of both minicircles and maxicircles was inhibited. RNAi or overexpression of TbKAP6 resulted in the disorganization, shrinkage, and loss of kDNA. Minicircle release, the first step in kDNA replication, was inhibited immediately after induction of RNAi, but it quickly increased 3-fold upon overexpression of TbKAP6. Since the release of covalently closed minicircles is mediated by a type II topoisomerase (topo II), we examined the potential interactions between TbKAP6 and topo II. Recombinant TbKAP6 (rTbKAP6) promotes the topo II-mediated decatenation of kDNA. rTbKAP6 can condense isolated kDNA networks in vitro . These results indicate that TbKAP6 is involved in the replication and maintenance of kDNA.

scholarly journals Angiotensin II Signaling Promotes Follicle Growth and Dominance in Cattle

Endocrinology ◽  
2011 ◽  
Vol 152 (12) ◽  
pp. 4957-4965 ◽  
Author(s):  
Rogério Ferreira ◽  
Bernardo Gasperin ◽  
Monique Rovani ◽  
Joabel Santos ◽  
Marcos Barreta ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Granulosa Cell ◽  
Inhibitory Effect ◽  
Mrna Levels ◽  
Follicular Growth ◽  
Dominant Follicle ◽  
Follicle Growth ◽  
Angiotensin Ii Signaling

It is generally understood that angiotensin II (AngII) promotes follicle atresia in rats, although recent data suggested that this may not be true in cattle. In this study, we aimed to determine in vivo whether AngII alters follicle development in cattle, using intrafollicular injection of AngII or antagonist into the growing dominant follicle or the second largest subordinate follicle. Injection of saralasin, an AngII antagonist, into the growing dominant follicle inhibited follicular growth, and this inhibitory effect was overcome by systemic FSH supplementation. Injection of AngII into the dominant follicle did not affect follicular growth, whereas injection of AngII into the second largest follicle prevented the expected atresia of this subordinate follicle, and the treated follicle grew at the same rate as the dominant follicle for the next 24 h. Inhibition of AngII action in the dominant follicle decreased estradiol concentrations in follicular fluid and the abundance of mRNA encoding aromatase, 3β-hydroxysteroid dehydrogenase, LH receptor, and cyclinD2 in granulosa cells, with minimal effects on theca cells. The effect of AngII on aromatase mRNA levels was confirmed using an in vitro granulosa cell culture system. In conclusion, these data suggest that AngII signaling promotes follicle growth in cattle and does so by regulating genes involved in estradiol secretion and granulosa cell proliferation and differentiation.

Neopterin-induced Suppression of Erythropoietin Production In Vitro

Pteridines ◽  
1995 ◽  
Vol 6 (1) ◽  
pp. 12-16 ◽  
Author(s):  
W. Schobersberger ◽  
W. Jelkmann ◽  
J. Fandrey ◽  
S. Frede ◽  
H. Wachter ◽  
...  
Keyword(s):  
Inhibitory Effect ◽  
Inhibitory Influence ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Anemia Of Chronic Disease ◽  
Erythropoietin Production ◽  
High Concentrations ◽  
Dose Dependent

Summary The production of neopterin increases in several diseases with activation of the ceIlular immune response. As previously shown serum concentrations of neopterin are inversely correlated with blood hemoglobin concentrations in the anemia of hematological and malignant disorders. Besides the role of chronic immune activation on the disturbed iron metabolism, an inhibitory influence of pteridines on cellular erythropoietin production could not be excluded. To test the possibility that pteridines are able to suppress the hypoxia-induced production of erythropoietin, the effects of neopterin and 7,8-dihydroneopterin on the human ceIl line HepG2 (hepatoceIlular carcinoma) were investigated. 24 h incubation with neopterin induced a dose-dependent reduction of erythropoietin production. The erythropoietin concentration significantly decreased by - 57.6% with 300 11M and by - 34.9% with 100 11M neopterin, respectively. 7,8 dihydroneopterin did not influence erythropoietin production. The inhibitory effect of neopterin on erythropoietin production was a consequence of reduced erythropoietin-mRNA levels. The results of this study show a neopterin-induced suppression of hypoxia-induced erythropoietin formation in HepG2 cultures in a dose dependent manner. We speculate that under in vivo conditions high concentrations of neopterin can aggravate the anemia of chronic disease.

scholarly journals Properties of the yeast nuclear histone deacetylase

1994 ◽  
Vol 303 (3) ◽  
pp. 723-729 ◽  
Author(s):  
M M Sanchez del Pino ◽  
G Lopez-Rodas ◽  
R Sendra ◽  
V Tordera
Keyword(s):  
Molecular Mass ◽  
Histone Deacetylase ◽  
Trichostatin A ◽  
High Mobility ◽  
Inhibitory Effect ◽  
High Molecular Mass ◽  
Core Histones ◽  
Nuclear Histone

A nuclear histone deacetylase from yeast was partially purified and some of its characteristics were studied. Histone deacetylase activity was stimulated in vitro by high-mobility-group nonhistone chromatin proteins 1 and 2 and ubiquitin and inhibited by spermine and spermidine, whereas n-butyrate had no significant inhibitory effect. Like the mammalian enzyme, partially purified histone deacetylase from yeast was strongly inhibited by trichostatin A. However, in crude extract preparations the yeast enzyme was not inhibited and treatment with trichostatin in vivo did not show any effect, either on the histone acetylation level or on cell viability. At low ionic strength, the enzyme can be isolated as a complex of high molecular mass that is much less inhibited by trichostatin A than is partially purified histone deacetylase activity. Furthermore, radiolabelled oligonucleosomes were more efficiently deacetylated by the complex than by the low-molecular-mass form of the enzyme. The histone deacetylase activity was separated from a polyamine deacetylase activity and its specificity studied. Using h.p.l.c.-purified core histone species as substrate, histone deacetylase from yeast is able to deacetylate all core histones with a slight preference for H3. Our results support the idea that the yeast histone deacetylase may act as a high-molecular-mass complex in vivo.

Cobalt exerts opposite effects on erythropoietin gene expression in rat hepatocytes in vivo and in vitro

1995 ◽  
Vol 269 (5) ◽  
pp. R995-R1001
Author(s):  
T. Gopfert ◽  
K. U. Eckardt ◽  
B. Gess ◽  
A. Kurtz
Keyword(s):  
Gene Expression ◽  
Oxygen Sensor ◽  
Rat Hepatocytes ◽  
Inhibitory Effect ◽  
Ribonuclease Protection Assay ◽  
Mrna Levels ◽  
Adult Rats ◽  
Ribonuclease Protection

This study investigates the effects of hypoxia and of cobalt on erythropoietin (EPO) gene expression in hepatocytes in vivo and in vitro in neonatal, juvenile, and adult rats. With the use of the ribonuclease protection assay to quantify RNA, both hypoxia (0.1% CO or 9% O2) and cobalt (60 mg/kg) elicit production of increased amounts of EPO mRNA in neonatal and juvenile rat liver in vivo. In vitro hepatocyte EPO gene expression could be reproducibly stimulated by hypoxia (3% O2) but not by cobaltous chloride (50-150 microM) within 2-20 h. Conversely, cobalt substantially attenuated the rise of EPO mRNA levels in response to hypoxia. This inhibitory effect of cobalt was mimicked by zinc but not by other metals. CO attenuated the rise of EPO mRNA levels in vitro in response to hypoxia; this inhibitory effect coincided with an inhibition of total RNA synthesis as determined by [3H]uridine incorporation. The lack of specific inhibitory effects of CO and of specific stimulatory effects of cobalt on hepatocyte EPO gene expression in vitro suggests that a specific heme oxygen sensor may be less important than in hepatoma cells.

scholarly journals Inhibitory effect of oestradiol on activation of rat hepatic stellate cells in vivo and in vitro

Gut ◽  
1999 ◽  
Vol 44 (1) ◽  
pp. 127-136 ◽  
Author(s):  
I Shimizu ◽  
Y Mizobuchi ◽  
M Yasuda ◽  
M Shiba ◽  
Y-R Ma ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Hepatic Stellate Cells ◽  
Stellate Cell ◽  
Stellate Cells ◽  
Inhibitory Effect ◽  
Type I ◽  
Mrna Levels ◽  
Pig Serum

BackgroundHepatic stellate cells play a key role in the pathogenesis of hepatic fibrosis.AimsTo examine the inhibitory effect of oestradiol on stellate cell activation.MethodsIn vivo, hepatic fibrosis was induced in rats by dimethylnitrosamine or pig serum. In vitro, rat stellate cells were activated by contact with plastic dishes resulting in their transformation into myofibroblast-like cells.ResultsIn the dimethylnitrosamine and pig serum models, treatment with oestradiol at gestation related doses resulted in a dose dependent suppression of hepatic fibrosis with restored content of hepatic retinyl palmitate, reduced collagen content, lower areas of stellate cells which express α smooth muscle actin (α-SMA) and desmin, and lower procollagen type I and III mRNA levels in the liver. In cultured stellate cells, oestradiol inhibited type I collagen production, α-SMA expression, and cell proliferation. These findings suggest that oestradiol is a potent inhibitor of stellate cell transformation.ConclusionThe antifibrogenic role of oestradiol in the liver may contribute to the sex associated differences in the progression from hepatic fibrosis to cirrhosis.

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