Xenopus laevis oocytes, eggs and tadpoles contain immunoactive insulin

1994 ◽  
Vol 141 (1) ◽  
pp. 123-129 ◽  
Author(s):  
F de Pablo ◽  
R Dashner ◽  
A R Shuldiner ◽  
J Roth
Keyword(s):  
Xenopus Laevis ◽  
High Performance ◽  
Immunoblot Analysis ◽  
Reversed Phase ◽  
Xenopus Laevis Oocytes ◽  
Maternal Origin ◽  
Insulin Mrna ◽  
Low Levels

Abstract Insulin is a multifunctional polypeptide hormone that regulates metabolic processes and promotes mitogenesis and differentiation in vitro in the cells and tissues of several species. Its role in vivo during embryogenesis is still poorly understood. We have previously found insulin mRNA in mature Xenopus laevis oocytes and in embryos during neurulation (before organogenesis of the pancreas takes place). We have now measured insulin immunoactivity in mature oocytes, unfertilized eggs and day-2 tadpoles. Using reversed phase high performance liquid chromatography, we found low levels of insulin in extracts of oocytes (stage VI). Both Xenopus insulin I and II were detected in unfertilized eggs. The day-2 tadpoles (stages 31–33) also contained immunoactive insulin, and in swimming tadpoles (stage 46) a few clusters of cells containing insulin immunoactivity could be identified by indirect immunofluorescence. Immunoblot analysis was relatively insensitive, detecting insulin only in the adult Xenopus pancreas. In summary, insulin (from maternal origin and embryonic expression) appears to be present early enough in Xenopus laevis to influence developmental processes such as neurulation. Journal of Endocrinology (1994) 141, 123–129

Purification of a p47 phosphoprotein from Xenopus laevis oocytes and identification as an in vivo and in vitro p34cdc2 substrate

FEBS Letters ◽  
1989 ◽  
Vol 251 (1-2) ◽  
pp. 219-224 ◽  
Author(s):  
Odile Mulner-Lorillon ◽  
Robert Poulhe ◽  
Patrick Cormier ◽  
Jean-Claude Labbe ◽  
Marcel Doree ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Xenopus Laevis Oocytes

scholarly journals Synthesis of Human Bone Morphogenetic Protein-2 (hBMP-2) in E. coli Periplasmic Space: Its Characterization and Preclinical Testing

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3525
Author(s):  
João E. Oliveira ◽  
Miriam F. Suzuki ◽  
Renata Damiani ◽  
Eliana R. Lima ◽  
Kleicy C. Amaral ◽  
...  
Keyword(s):  
High Performance ◽  
Osmotic Shock ◽  
Cytoplasmic Inclusion ◽  
Reversed Phase ◽  
C2c12 Cells ◽  
Size Exclusion ◽  
Bone Morphogenetic Protein 2 ◽  
E Coli

Human BMP-2, a homodimeric protein that belongs to the TGF- β family, is a recognized osteoinductor due to its capacity of inducing bone regeneration and ectopic bone formation. The administration of its recombinant form is an alternative to autologous bone grafting. A variety of E. coli-derived hBMP-2 has been synthesized through refolding of cytoplasmic inclusion bodies. The present work reports the synthesis, purification, and characterization of periplasmic hBMP-2, obtained directly in its correctly folded and authentic form, i.e., without the initial methionine typical of the cytoplasmic product that can induce undesired immunoreactivity. A bacterial expression vector was constructed including the DsbA signal peptide and the cDNA of hBMP-2. The periplasmic fluid was extracted by osmotic shock and analyzed via SDS-PAGE, Western blotting, and reversed-phase high-performance liquid chromatography (RP-HPLC). The purification was carried out by heparin affinity chromatography, followed by high-performance size-exclusion chromatography (HPSEC). HPSEC was used for qualitative and quantitative analysis of the final product, which showed >95% purity. The classical in vitro bioassay based on the induction of alkaline phosphatase activity in myoblastic murine C2C12 cells and the in vivo bioassay consisting of treating calvarial critical-size defects in rats confirmed its bioactivity, which matched the analogous literature data for hBMP-2.

Accurate in vitro transcription of Xenopus laevis mitochondrial DNA from two bidirectional promoters

1986 ◽  
Vol 6 (7) ◽  
pp. 2543-2550
Author(s):  
D F Bogenhagen ◽  
B K Yoza
Keyword(s):  
Mitochondrial Dna ◽  
Xenopus Laevis ◽  
Rna Polymerase ◽  
Consensus Sequence ◽  
In Vitro Transcription ◽  
Xenopus Laevis Oocytes ◽  
Mitochondrial Rna ◽  
Bidirectional Promoters

The mitochondrial RNA polymerase from Xenopus laevis oocytes was partially purified by heparin-Sepharose chromatography and phosphocellulose chromatography. This RNA polymerase preparation specifically initiated the transcription of X. laevis mitochondrial DNA (mtDNA) from two bidirectional promoters contained within a 123-base-pair segment of the mtDNA between the heavy-strand replication origin and the rRNA cistrons. Transcription in vitro initiated from precisely the same start sites previously mapped as initiation sites for transcription in vivo. At each of the four sites, initiation occurred within a conserved nucleotide sequence, ACPuTTATA. This consensus sequence is not related to promoters for transcription of human mtDNA.

scholarly journals 3'-end-dependent formation of U6 small nuclear ribonucleoprotein particles in Xenopus laevis oocyte nuclei.

1992 ◽  
Vol 12 (7) ◽  
pp. 3032-3040 ◽  
Author(s):  
M P Terns ◽  
E Lund ◽  
J E Dahlberg
Keyword(s):  
Xenopus Laevis ◽  
Nuclear Antigen ◽  
Xenopus Laevis Oocytes ◽  
Xenopus Laevis Oocyte ◽  
U6 Snrna ◽  
Small Nuclear Ribonucleoprotein ◽  
La Protein ◽  
Shift Analysis

We have identified and characterized a U6 small nuclear (sn) ribonucleoprotein particle (RNP) present in the nuclei of Xenopus laevis oocytes. The structure of this U6 snRNP was investigated by native gel shift analysis and a combination of RNA-protein UV cross-linking, RNase T1 fingerprinting, and immunoprecipitation assays. These analyses demonstrate that certain forms of U6 snRNA associate with the 50-kDa nuclear antigen La both in vivo and in vitro. The La protein binds the stretch of uridylates at the 3' hydroxyl end of newly synthesized U6 snRNA. La does not bind to mature U6 snRNAs that have 2',3'-cyclic phosphate (greater than p) groups at their 3' ends (E. Lund and J. E. Dahlberg, Science 255:327-330, 1992) or to U6 snRNAs in anti-Sm-precipitable U4/U6 snRNPs. We propose that 3'-end modification, including posttranscriptional UMP addition, modulates the binding of La protein to U6 snRNA which, in turn, may affect the function of this RNA.

scholarly journals Physical exercise increases urinary excretion of lipoxin A4 and related compounds

2003 ◽  
Vol 94 (6) ◽  
pp. 2237-2240 ◽  
Author(s):  
Sebastiano Gangemi ◽  
Graziella Luciotti ◽  
Etrusca D'Urbano ◽  
Agostino Mallamace ◽  
Domenico Santoro ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
High Performance ◽  
Reversed Phase ◽  
Strenuous Exercise ◽  
Lipoxin A4 ◽  
Safeguard Mechanism ◽  
First Time ◽  
Related Compounds

Lipoxins (LX) are lipoxygenase-derived eicosanoids with potent anti-inflammatory activities and vascular bed-dependent vasodilatory actions. LX can be formed in vitro and in vivo in a number of conditions, and we have reported that immunoreactive LXA4 (iLXA4) is physiologically excreted with human urine. Using a recently developed LX extraction method coupled to an ELISA, we examined whether iLXA4 excretion was modified by strenuous exercise, which is known to trigger potential LX-forming events. Maximal exertion significantly increased iLXA4 urinary excretion in nine healthy volunteers (0.061 ± 0.023 vs. 0.113 ± 0.057 ng/mg creatinine; P = 0.028). iLXA4 levels returned to baseline after 6 h and increased, although at a smaller extent, after 24 h. A significant correlation ( r = 0.988) was denoted between iLXA4 ELISA measurements and reversed-phase high-performance liquid chromatography quantitation of a previously described urinary tetraene, confirming its LXA4-related nature. These findings show for the first time that an increase in excretion of LXA4-related compounds can be observed in response to strenuous exercise. This may be the reflection of an enhanced LX biosynthesis, which may represent a safeguard mechanism that keeps the inflammatory reaction triggered by physical stress under control.

scholarly journals Accurate in vitro transcription of Xenopus laevis mitochondrial DNA from two bidirectional promoters.

1986 ◽  
Vol 6 (7) ◽  
pp. 2543-2550 ◽  
Author(s):  
D F Bogenhagen ◽  
B K Yoza
Keyword(s):  
Mitochondrial Dna ◽  
Xenopus Laevis ◽  
Rna Polymerase ◽  
Consensus Sequence ◽  
In Vitro Transcription ◽  
Xenopus Laevis Oocytes ◽  
Mitochondrial Rna ◽  
Bidirectional Promoters

The mitochondrial RNA polymerase from Xenopus laevis oocytes was partially purified by heparin-Sepharose chromatography and phosphocellulose chromatography. This RNA polymerase preparation specifically initiated the transcription of X. laevis mitochondrial DNA (mtDNA) from two bidirectional promoters contained within a 123-base-pair segment of the mtDNA between the heavy-strand replication origin and the rRNA cistrons. Transcription in vitro initiated from precisely the same start sites previously mapped as initiation sites for transcription in vivo. At each of the four sites, initiation occurred within a conserved nucleotide sequence, ACPuTTATA. This consensus sequence is not related to promoters for transcription of human mtDNA.

scholarly journals In Vitro and In Vivo Evaluation of Two Hydroxychloroquine Tablet Formulations: HPLC Assay Development

2020 ◽  
Vol 59 (1) ◽  
pp. 71-78
Author(s):  
Jaber Emami ◽  
Moloud Kazemi ◽  
Anahita Salehi
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Reversed Phase ◽  
Hplc Method ◽  
In Vivo Studies ◽  
Crossover Fashion ◽  
Content Uniformity ◽  
In Vivo Evaluation

Abstract The relative in vitro and in vivo evaluation of two hydroxychloroquine (HCQ) products was conducted. In vitro studies involved assay, content uniformity and dissolution test, and a two-way crossover fashion were used for in vivo studies. Blood samples were collected at appropriate intervals and HCQ levels were measured using a validated reversed-phase high-performance liquid chromatography (HPLC) method. The drug and the internal standard, chloroquine (CQ), were extracted from blood with diethyl ether, separated and dried under nitrogen gas. Residues were reconstituted in the mobile phase and analyzed at 340 nm on a μ-bondapack C18 (250 × 4.6 mm) HPLC column with acetonitrile:methanol:KH2PO4 (10:10:80) mixture containing 0.01% triethylamine. The standard curve was linear within 50–1,500 ng/mL HCQ (R2 = 0.9996), relative errors were 1.6 to 5%, and the CV% ranged from 7 to 15.4. The resolution factor and RSD were 1.62 and 0.35% and in vitro data of both products met the USP requirements. The 90% confidence intervals for the ratios of the AUC0–96, Cmax and Tmax and their corresponding logarithmically transformed values of generic product over those of Plaquenil® were within the acceptable limit of 0.80–1.20 and 0.80–1.25, respectively. Therefore, the generic HCQ was bioequivalent to the innovator formulation.

scholarly journals 3'-end-dependent formation of U6 small nuclear ribonucleoprotein particles in Xenopus laevis oocyte nuclei

1992 ◽  
Vol 12 (7) ◽  
pp. 3032-3040
Author(s):  
M P Terns ◽  
E Lund ◽  
J E Dahlberg
Keyword(s):  
Xenopus Laevis ◽  
Nuclear Antigen ◽  
Xenopus Laevis Oocytes ◽  
Xenopus Laevis Oocyte ◽  
U6 Snrna ◽  
Small Nuclear Ribonucleoprotein ◽  
La Protein ◽  
Shift Analysis

We have identified and characterized a U6 small nuclear (sn) ribonucleoprotein particle (RNP) present in the nuclei of Xenopus laevis oocytes. The structure of this U6 snRNP was investigated by native gel shift analysis and a combination of RNA-protein UV cross-linking, RNase T1 fingerprinting, and immunoprecipitation assays. These analyses demonstrate that certain forms of U6 snRNA associate with the 50-kDa nuclear antigen La both in vivo and in vitro. The La protein binds the stretch of uridylates at the 3' hydroxyl end of newly synthesized U6 snRNA. La does not bind to mature U6 snRNAs that have 2',3'-cyclic phosphate (greater than p) groups at their 3' ends (E. Lund and J. E. Dahlberg, Science 255:327-330, 1992) or to U6 snRNAs in anti-Sm-precipitable U4/U6 snRNPs. We propose that 3'-end modification, including posttranscriptional UMP addition, modulates the binding of La protein to U6 snRNA which, in turn, may affect the function of this RNA.

Polyphenols from Euphorbia pekinensis Inhibit AGEs Formation In Vitro and Vessel Dilation in Larval Zebrafish In Vivo

Planta Medica ◽  
2017 ◽  
Vol 84 (03) ◽  
pp. 176-181 ◽  
Author(s):  
Ik-Soo Lee ◽  
Seung-Hyun Jung ◽  
Jin Kim
Keyword(s):  
Ellagic Acid ◽  
High Performance ◽  
Spectroscopic Studies ◽  
Reversed Phase ◽  
Control Group ◽  
Retinal Vessels ◽  
Etoh Extract ◽  
Larval Zebrafish

AbstractTo identify active compounds in the roots of Euphorbia pekinensis for treatment of diabetic complications, an active column fraction from a 70% EtOH extract of E. pekinensis root was purified by preparative reversed-phase high-performance liquid chromatography, leading to the isolation of a new ellagic acid derivative, 3,3′-di-O-methylellagic acid 4-O-(6ʺ-O-galloyl)-β-D-galactopyranoside (1), along with three known compounds, geraniin (2), 3,3′-di-O-methylellagic acid 4-O-β-D-xylopyranoside (3), and ellagic acid 3,3′-dimethyl ether (4). The structure of the new compound was established by extensive spectroscopic studies and chemical evidence. The inhibitory effects of isolated compounds 1–4 on advanced glycation end-products (AGEs) formation were examined. All compounds exhibited considerable inhibition of AGEs formation and IC50 values of 0.41 – 12.33 µM, compared with those of the positive controls aminoguanidine (IC50 = 1122.34 µM) and quercetin (IC50 = 27.80 µM). In addition, the effects of 2 and 4 on the dilation of hyaloid-retinal vessels induced by high glucose (HG) in larval zebrafish were investigated; both compounds significantly reduced the HG-induced dilation of hyaloid-retinal vessels relative to the HG-treated control group.

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