scholarly journals Autoinduction of activin genes in early Xenopus embryos

1994 ◽  
Vol 298 (2) ◽  
pp. 275-280 ◽  
Author(s):  
A Suzuki ◽  
T Nagai ◽  
S I Nishimatsu ◽  
H Sugino ◽  
Y Eto ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mrna Levels ◽  
Xenopus Embryos ◽  
Treatment Conditions ◽  
Dose Dependent Fashion ◽  
Polymerase Chain ◽  
Stage 1 ◽  
Dose Dependent

Activin exhibits a potent mesoderm inducing activity towards the ectodermal tissue (animal cap) of Xenopus laevis blastulae. Thus in order to investigate the role of activin in morphogenesis of early Xenopus embryos, activation of genes for activin beta A and beta B was examined by the reverse transcription polymerase chain reaction. In vivo, activin beta B mRNA appears to be present in embryonic stage 1 whereas beta A mRNA is undetectable prior to gastrulation. beta B and beta A mRNAs were noted to accumulate after stages 9 and 15 respectively. Activin gene expression in Xenopus animal caps was examined after treatment with various concentrations of activin A. Under these treatment conditions, both activin beta A and beta B mRNAs accumulated in a dose-dependent fashion after 24 h. The same effect was noted for treatment with similar concentrations of activin B. Accumulation of mRNAs was inhibited by the addition of cycloheximide to the culture medium, consistent with the proposition that activin gene expression requires certain protein factors. In total, therefore, these data suggest that an autoinduction mechanism is involved in the regulation of activin mRNA levels in normal Xenopus embryos and that this mechanism may play a pivotal role during early embryonic development.

scholarly journals MOZ and BMI1 play opposing roles during Hox gene activation in ES cells and in body segment identity specification in vivo

2015 ◽  
Vol 112 (17) ◽  
pp. 5437-5442 ◽  
Author(s):  
Bilal N. Sheikh ◽  
Natalie L. Downer ◽  
Belinda Phipson ◽  
Hannah K. Vanyai ◽  
Andrew J. Kueh ◽  
...  
Keyword(s):  
Gene Expression ◽  
Es Cells ◽  
Gene Activation ◽  
Embryonic Stem ◽  
Mrna Levels ◽  
Body Segment ◽  
Initial Activation ◽  
Activation Phase

Hox genes underlie the specification of body segment identity in the anterior–posterior axis. They are activated during gastrulation and undergo a dynamic shift from a transcriptionally repressed to an active chromatin state in a sequence that reflects their chromosomal location. Nevertheless, the precise role of chromatin modifying complexes during the initial activation phase remains unclear. In the current study, we examined the role of chromatin regulators during Hox gene activation. Using embryonic stem cell lines lacking the transcriptional activator MOZ and the polycomb-family repressor BMI1, we showed that MOZ and BMI1, respectively, promoted and repressed Hox genes during the shift from the transcriptionally repressed to the active state. Strikingly however, MOZ but not BMI1 was required to regulate Hox mRNA levels after the initial activation phase. To determine the interaction of MOZ and BMI1 in vivo, we interrogated their role in regulating Hox genes and body segment identity using Moz;Bmi1 double deficient mice. We found that the homeotic transformations and shifts in Hox gene expression boundaries observed in single Moz and Bmi1 mutant mice were rescued to a wild type identity in Moz;Bmi1 double knockout animals. Together, our findings establish that MOZ and BMI1 play opposing roles during the onset of Hox gene expression in the ES cell model and during body segment identity specification in vivo. We propose that chromatin-modifying complexes have a previously unappreciated role during the initiation phase of Hox gene expression, which is critical for the correct specification of body segment identity.

Thrombopoietin in thrombocytopenic mice: evidence against regulation at the mRNA level and for a direct regulatory role of platelets

Blood ◽  
1996 ◽  
Vol 87 (2) ◽  
pp. 567-573 ◽  
Author(s):  
R Stoffel ◽  
A Wiestner ◽  
RC Skoda
Keyword(s):  
Mrna Level ◽  
Rnase Protection Assay ◽  
Chain Reaction ◽  
Rnase Protection ◽  
Dose Dependent Fashion ◽  
Liver And Kidney ◽  
Polymerase Chain ◽  
Dose Dependent ◽  
Posttranscriptional Level

Thrombopoietin (TPO), originally described as an activity in the serum of thrombocytopenic animals that leads to increased production of platelets, has recently been isolated and cloned. Its closest relative in the cytokine superfamily, erythropoietin (EPO), is transcriptionally regulated during anemia, and it was expected that TPO would similarly be regulated during thrombocytopenia. We induced thrombocytopenia in mice and confirmed that TPO activity was upregulated, as determined by a bioassay. Liver and kidney were found to be the major sources of TPO mRNA. Surprisingly, TPO mRNA in these tissues was not upregulated in thrombocytopenic mice. Using a sensitive RNase protection assay that can distinguish between TPO isoforms, we found no change in the profile of mRNA for these isoforms. A semiquantitative reverse transcription- polymerase chain reaction assay also did not demonstrate upregulation of TPO mRNA in the spleen. Thus, the increase of TPO activity during thrombocytopenia is not caused by regulation at the level of TPO mRNA. Furthermore, isolated mouse platelets absorbed high amounts of bioactive TPO out of TPO-conditioned medium in a dose-dependent fashion. Our results are consistent with TPO protein being regulated at a posttranscriptional level and/or directly through absorption and metabolism by platelets.

scholarly journals Methylation and Gene Expression of BCAT1 and IKZF1 in Colorectal Cancer Tissues

2018 ◽  
Vol 12 ◽  
pp. 117955491877506 ◽  
Author(s):  
Maher Jedi ◽  
Graeme P Young ◽  
Susanne K Pedersen ◽  
Erin L Symonds
Keyword(s):  
Gene Expression ◽  
Colorectal Cancer ◽  
Messenger Rna ◽  
Stage Iv ◽  
Mrna Levels ◽  
Polymerase Chain ◽  
Cancer Tissues ◽  
The Relationship ◽  
Neoplastic Tissues

The genes BCAT1 and IKZF1 are hypermethylated in colorectal cancer (CRC), but little is known about how this relates to gene expression. This study assessed the relationship between methylation and gene expression of BCAT1 and IKZF1 in CRC and adjacent non-neoplastic tissues. The tissues were obtained at surgery from 36 patients diagnosed with different stages of CRC (stage I n = 8, stage II n = 13, stage III n = 10, stage IV n = 5). Methylated BCAT1 and IKZF1 were detected in 92% and 72% CRC tissues, respectively, with levels independent of stage ( P > .05). In contrast, only 31% and 3% of non-neoplastic tissues were methylated for BCAT1 and IKZF1, respectively ( P < .001). The IKZF1 messenger RNA (mRNA) expression was significantly lower in the cancer tissues compared with that of non-neoplastic tissues, whereas the BCAT1 mRNA levels were similar. The latter may be due to the BCAT1 polymerase chain reaction assay detecting more than 1 mRNA transcript. Further studies are warranted to establish the role of the epigenetic silencing of IKZF1 in colorectal oncogenesis.

scholarly journals Foxa1 and Foxa2 Regulate α-Cell Differentiation, Glucagon Biosynthesis, and Secretion

Endocrinology ◽  
2014 ◽  
Vol 155 (10) ◽  
pp. 3781-3792 ◽  
Author(s):  
Mounia Heddad Masson ◽  
Caroline Poisson ◽  
Audrey Guérardel ◽  
Aline Mamin ◽  
Jacques Philippe ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Differentiation ◽  
Target Genes ◽  
Adult Mouse ◽  
Glucagon Secretion ◽  
Mrna Levels ◽  
Forkhead Box ◽  
Interfering Rna

Abstract The Forkhead box A transcription factors are major regulators of glucose homeostasis. They show both distinct and redundant roles during pancreas development and in adult mouse β-cells. In vivo ablation studies have revealed critical implications of Foxa1 on glucagon biosynthesis and requirement of Foxa2 in α-cell terminal differentiation. In order to examine the respective role of these factors in mature α-cells, we used small interfering RNA (siRNA) directed against Foxa1 and Foxa2 in rat primary pancreatic α-cells and rodent α-cell lines leading to marked decreases in Foxa1 and Foxa2 mRNA levels and proteins. Both Foxa1 and Foxa2 control glucagon gene expression specifically through the G2 element. Although we found that Foxa2 controls the expression of the glucagon, MafB, Pou3f4, Pcsk2, Nkx2.2, Kir6.2, and Sur1 genes, Foxa1 only regulates glucagon gene expression. Interestingly, the Isl1 and Gipr genes were not controlled by either Foxa1 or Foxa2 alone but by their combination. Foxa1 and Foxa2 directly activate and bind the promoter region the Nkx2.2, Kir6.2 and Sur1, Gipr, Isl1, and Pou3f4 genes. We also demonstrated that glucagon secretion is affected by the combined effects of Foxa1 and Foxa2 but not by either one alone. Our results indicate that Foxa1 and Foxa2 control glucagon biosynthesis and secretion as well as α-cell differentiation with both common and unique target genes.

Incorporation of an interferon-β neutralizing antibody assay into routine clinical practice

2011 ◽  
Vol 17 (11) ◽  
pp. 1333-1340 ◽  
Author(s):  
RA Farrell ◽  
M Espasandin ◽  
N Lakdawala ◽  
PI Creeke ◽  
V Worthington ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Luciferase Assay ◽  
Post Injection ◽  
Post Dose ◽  
Therapeutic Decisions ◽  
Dose Dependent Fashion ◽  
Polymerase Chain ◽  
Dose Dependent

Background: Incorporation of routine clinical testing for neutralizing antibodies (NAbs) to interferon (IFN)-β has remained problematic. With increasing treatment choice for patients, routine NAb testing should be incorporated to aid therapeutic decisions. Objective: We sought to improve interpretation of NAb results by combining the luciferase NAb assay (luciferase gene expression assay under control of interferon-stimulated response element) and in-vivo biomarker (myxovirus A protein, MxA) induction in patients with MS. Methods: Blood samples (serum and PAXGene® for RNA) were obtained pre-injection and 12 hours post-injection of IFN-β from 144 subjects. Sera were tested for NAbs using the luciferase assay. MxA expression was quantified by real-time polymerase chain reaction (PCR). Results: 26% of samples were NAb positive (titre > 20 NU). There was no difference in NAb titres in the pre- or post-dose sera ( p = 0.643). MxA expression was inhibited in a dose-dependent fashion in NAb positive samples. Mean MxA level post-IFN-β: NAb negative 2330 (95% CI 1940–2719), NAb 20–99 NU 1533 (95% CI 741–2324), NAb 100–600 NU 832 (186–1478) and NAb > 600 NU 101 (95% CI 0–224). NAb titre and MxA level correlated strongly: MxA pre- (Spearman r = −0.72, p < 0.0001), MxA post- (Spearman r = −0.79, p < 0.0001) and MxA induction (Spearman r = −0.67, p = 0.0004). Conclusion: A single, 12-hour post-injection sample should be used to test for NAbs using the luciferase assay and IFN-β bioactivity (MxA) in the clinical setting.

Role of serotonin type 2 receptors in regulation of aldosterone production

1985 ◽  
Vol 249 (2) ◽  
pp. E234-E238 ◽  
Author(s):  
H. Matsuoka ◽  
M. Ishii ◽  
A. Goto ◽  
T. Sugimoto
Keyword(s):  
Serotonin Antagonists ◽  
Camp Production ◽  
Inhibitory Effects ◽  
Aldosterone Production ◽  
Dose Dependent Fashion ◽  
Dose Dependent

It is well recognized that serotonin stimulates aldosterone production by the adrenal glands. To investigate the possible roles of serotonin type 1 and 2 receptors in the regulation of aldosterone production, we examined the effects of cyproheptadine (a serotonin antagonist that inhibits both type 1 and 2 receptors) and ketanserin (a serotonin type 2 selective antagonist) on aldosterone and cAMP production in collagenase dispersed rat adrenal capsular cells. Serotonin, ranging in concentration from 10(-9) to 10(-3) M, significantly increased aldosterone production in a dose-dependent fashion after 2 h of incubation at 37 degrees C. Cyproheptadine and ketanserin showed comparable inhibitory effects on basal aldosterone production. These serotonin antagonists preferentially inhibited serotonin-induced aldosterone production. Serotonin significantly increased cAMP production at a dose of 10(-6) M. Both cyproheptadine and ketanserin significantly decreased basal cAMP production at doses of 10(-5) M. These serotonin antagonists preferentially inhibited serotonin-stimulated cAMP production. These results suggest that adrenal serotonin type 2 receptors may be coupled with adenylate cyclase activity and that these receptors are involved in the regulation of aldosterone production. Whether serotonin plays an important role in the regulation of aldosterone secretion in vivo remains to be elucidated.

Soluble Thrombomodulin Purified from Human Urine Exhibits a Potent Anticoagulant Effect In Vitro and In Vivo

1995 ◽  
Vol 73 (05) ◽  
pp. 805-811 ◽  
Author(s):  
Yasuo Takahashi ◽  
Yoshitaka Hosaka ◽  
Hiromi Niina ◽  
Katsuaki Nagasawa ◽  
Masaaki Naotsuka ◽  
...  
Keyword(s):  
Human Urine ◽  
Specific Activity ◽  
Anticoagulant Activity ◽  
Rabbit Lung ◽  
Soluble Thrombomodulin ◽  
Molecular Weights ◽  
Dose Dependent Fashion ◽  
Dose Dependent

SummaryWe examined the anticoagulant activity of two major molecules of soluble thrombomodulin purified from human urine. The apparent molecular weights of these urinary thrombomodulins (UTMs) were 72,000 and 79,000, respectively. Both UTMs showed more potent cofactor activity for protein C activation [specific activity >5,000 thrombomodulin units (TMU)/mg] than human placental thrombomodulin (2,180 TMU/mg) and rabbit lung thrombomodulin (1,980 TMU/mg). The UTMs prolonged thrombin-induced fibrinogen clotting time (>1 TMU/ml), APTT (>5 TMU/ml), TT (>5 TMU/ml) and PT (>40 TMU/ml) in a dose-dependent fashion. These effects appeared in the concentration range of soluble thrombomodulins present in human plasma and urine. In the rat DIC model induced by thromboplastin, administration of UTMs by infusion (300-3,000 TMU/kg) restored the hematological abnormalities derived from DIC in a dose-dependent fashion. These results demonstrate that UTMs exhibit potent anticoagulant and antithrombotic activities, and could play a physiologically important role in microcirculation.

scholarly journals A Yes-Associated Protein (YAP) and Insulin-Like Growth Factor 1 Receptor (IGF-1R) Signaling Loop Is Involved in Sorafenib Resistance in Hepatocellular Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3812
Author(s):  
Mai-Huong T. Ngo ◽  
Sue-Wei Peng ◽  
Yung-Che Kuo ◽  
Chun-Yen Lin ◽  
Ming-Heng Wu ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Combination Index ◽  
Specific Inhibitor ◽  
In Vivo Model ◽  
Mrna Levels ◽  
Margin Distribution ◽  
Related Proteins ◽  
Emt Markers

The role of a YAP-IGF-1R signaling loop in HCC resistance to sorafenib remains unknown. Method: Sorafenib-resistant cells were generated by treating naïve cells (HepG2215 and Hep3B) with sorafenib. Different cancer cell lines from databases were analyzed through the ONCOMINE web server. BIOSTORM–LIHC patient tissues (46 nonresponders and 21 responders to sorafenib) were used to compare YAP mRNA levels. The HepG2215_R-derived xenograft in SCID mice was used as an in vivo model. HCC tissues from a patient with sorafenib failure were used to examine differences in YAP and IGF-R signaling. Results: Positive associations exist among the levels of YAP, IGF-1R, and EMT markers in HCC tissues and the levels of these proteins increased with sorafenib failure, with a trend of tumor-margin distribution in vivo. Blocking YAP downregulated IGF-1R signaling-related proteins, while IGF-1/2 treatment enhanced the nuclear translocation of YAP in HCC cells through PI3K-mTOR regulation. The combination of YAP-specific inhibitor verteporfin (VP) and sorafenib effectively decreased cell viability in a synergistic manner, evidenced by the combination index (CI). Conclusion: A YAP-IGF-1R signaling loop may play a role in HCC sorafenib resistance and could provide novel potential targets for combination therapy with sorafenib to overcome drug resistance in HCC.

scholarly journals Quantitative assessment of CYP11B1 and CYP11B2 expression in aldosterone-producing adenomas

2002 ◽  
pp. 795-802 ◽  
Author(s):  
F Fallo ◽  
V Pezzi ◽  
L Barzon ◽  
P Mulatero ◽  
F Veglio ◽  
...  
Keyword(s):  
Real Time ◽  
Secretory Activity ◽  
Zona Glomerulosa ◽  
Zona Fasciculata ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Pathophysiological Role ◽  
Aldosterone Production

BACKGROUND: The presence and pathophysiological role of CYP11B1 (11beta-hydroxylase) gene in the zona glomerulosa of human adrenal cortex is still controversial. METHODS: In order to specifically quantify CYP11B1, CYP11B2 (aldosterone synthase) and CYP17(17alpha-hydroxylase) mRNA levels, we developed a real-time RT-PCR assay and examined the expression in a series of adrenal tIssues, including six normal adrenals from patients adrenalectomized for renal cancer and twelve aldosterone-producing adenomas (APA) from patients with primary aldosteronism. RESULTS: CYP11B1 mRNA levels were clearly detected in normal adrenals, which comprised both zona glomerulosa and fasciculata/reticularis cells, but were also measured at a lower range (P<0.05) in APA. The levels of CYP11B2 mRNA were lower (P<0.005) in normal adrenals than in APA. CYP17 mRNAlevels were similar in normal adrenals and in APA. In patients with APA, CYP11B2 and CYP11B1 mRNA levels were not correlated either with basal aldosterone or with the change from basal aldosterone in response to posture or to dexamethasone. No correlation between CYP11B1 mRNA or CYP11B2 mRNA and the percentage of zona fasciculata-like cells was observed in APA. CONCLUSIONS: Real-time RT-PCR can be reliably used to quantify CYP11B1 and CYP11B2 mRNA levels in adrenal tIssues. Expression of CYP11B1 in hyperfunctioning zona glomerulosa suggests an additional formation of corticosterone via 11beta-hydroxylase, providing further substrate for aldosterone biosynthesis. CYP11B1 and CYP11B2 mRNA levels in APA are not related to the in vivo secretory activity of glomerulosa cells, where post-transcriptional factors might ultimately regulate aldosterone production.

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