scholarly journals Post-translational alterations in newly synthesized cartilage proteoglycans induced by the glutamine analogue 6-diazo-5-oxo-l-norleucine. Time course of inhibition and recovery

1991 ◽  
Vol 273 (2) ◽  
pp. 283-288 ◽  
Author(s):  
C C Clark ◽  
C F Richards ◽  
R V Iozzo
Keyword(s):  
Time Course ◽  
Chondroitin Sulphate ◽  
Time Dependent ◽  
Dependent Manner ◽  
Cartilage Proteoglycan ◽  
Chondroitin Sulphate Proteoglycan ◽  
Cartilage Proteoglycans ◽  
Matrix Free ◽  
Subsequent Addition

Incorporation of [35S]sulphate by cultures of matrix-free cells from chick embryo sterna in the presence of the glutamine analogue 6-diazo-5-oxo-L-norleucine (0.58 mM) was inhibited in a time-dependent manner to less than 15% of that in control cultures after 2 h. Characterization of the major cartilage proteoglycan synthesized under these conditions showed that it contained few, if any, normal-sized chondroitin sulphate chains and only about half of the normal complement of substituted serine residues. Subsequent addition of D-glucosamine hydrochloride (final concn. 2 mM) resulted in a time-dependent recovery of [35S]sulphate incorporation to 90% of control cultures after 2 h, but restored the chondroitin sulphate chains to normal size within 15 min. On the basis of these results, it is concluded that a 2 h preincubation is necessary to deplete the chondrocytes of the endogenous supply of UDP-N-acetyl-D-glucosamine required for optimal glycoconjugate synthesis, and that this situation results in the synthesis of a chondroitin sulphate proteoglycan with significantly altered properties, owing to the paucity of glycosaminoglycan chains; however, this condition is completely reversible if the D-glucosamine pool is repleted.

scholarly journals New Insights into the Pleiotropic Drug Resistance Network from Genome-Wide Characterization of the YRR1 Transcription Factor Regulation System

2002 ◽  
Vol 22 (8) ◽  
pp. 2642-2649 ◽  
Author(s):  
Stéphane Le Crom ◽  
Frédéric Devaux ◽  
Philippe Marc ◽  
Xiaoting Zhang ◽  
W. Scott Moye-Rowley ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Transcription Factor ◽  
Binding Site ◽  
Time Course ◽  
Target Genes ◽  
Regulation System ◽  
Dependent Manner ◽  
Pleiotropic Drug Resistance ◽  
Genome Wide

ABSTRACT Yrr1p is a recently described Zn2Cys6 transcription factor involved in the pleiotropic drug resistance (PDR) phenomenon. It is controlled in a Pdr1p-dependent manner and is autoregulated. We describe here a new genome-wide approach to characterization of the set of genes directly regulated by Yrr1p. We found that the time-course production of an artificial chimera protein containing the DNA-binding domain of Yrr1p activated the 15 genes that are also up-regulated by a gain-of-function mutant of Yrr1p. Gel mobility shift assays showed that the promoters of the genes AZR1, FLR1, SNG1, YLL056C, YLR346C, and YPL088W interacted with Yrr1p. The putative consensus Yrr1p binding site deduced from these experiments, (T/A)CCG(C/T)(G/T)(G/T)(A/T)(A/T), is strikingly similar to the PDR element binding site sequence recognized by Pdr1p and Pdr3p. The minor differences between these sequences are consistent with Yrr1p and Pdr1p and Pdr3p having different sets of target genes. According to these data, some target genes are directly regulated by Pdr1p and Pdr3p or by Yrr1p, whereas some genes are indirectly regulated by the activation of Yrr1p. Some genes, such as YOR1, SNQ2, and FLR1, are clearly directly controlled by both classes of transcription factor, suggesting an important role for the corresponding membrane proteins.

scholarly journals Binding of Delta1, Jagged1, and Jagged2 to Notch2 Rapidly Induces Cleavage, Nuclear Translocation, and Hyperphosphorylation of Notch2

2000 ◽  
Vol 20 (18) ◽  
pp. 6913-6922 ◽  
Author(s):  
Kiyoshi Shimizu ◽  
Shigeru Chiba ◽  
Noriko Hosoya ◽  
Keiki Kumano ◽  
Toshiki Saito ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Notch Signaling ◽  
Time Course ◽  
Nuclear Translocation ◽  
Reporter Genes ◽  
Time Dependent ◽  
Dependent Manner ◽  
Notch Receptors ◽  
Notch Protein ◽  
Membrane Spanning

ABSTRACT Delta1, Jagged1, and Jagged2, commonly designated Delta/Serrate/LAG-2 (DSL) proteins, are known to be ligands for Notch1. However, it has been less understood whether they are ligands for Notch receptors other than Notch1. Meanwhile, ligand-induced cleavage and nuclear translocation of the Notch protein are considered to be fundamental for Notch signaling, yet direct observation of the behavior of the Notch molecule after ligand binding, including cleavage and nuclear translocation, has been lacking. In this report, we investigated these issues for Notch2. All of the three DSL proteins bound to endogenous Notch2 on the surface of BaF3 cells, although characteristics of Jagged2 for binding to Notch2 apparently differed from that of Delta1 and Jagged1. After binding, the three DSL proteins induced cleavage of the membrane-spanning subunit of Notch2 (Notch2TM), which occurred within 15 min. In a simultaneous time course, the cleaved fragment of Notch2TMwas translocated into the nucleus. Interestingly, the cleaved Notch2 fragment was hyperphosphorylated also in a time-dependent manner. Finally, binding of DSL proteins to Notch2 also activated the transcription of reporter genes driven by the RBP-Jκ-responsive promoter. Together, these data indicate that all of these DSL proteins function as ligands for Notch2. Moreover, the findings of rapid cleavage, nuclear translocation, and phosphorylation of Notch2 after ligand binding facilitate the understanding of the Notch signaling.

scholarly journals Separation and characterization of two populations of aggregating proteoglycans from cartilage

1985 ◽  
Vol 225 (1) ◽  
pp. 95-106 ◽  
Author(s):  
D Heinegård ◽  
J Wieslander ◽  
J Sheehan ◽  
M Paulsson ◽  
Y Sommarin
Keyword(s):  
Chondroitin Sulphate ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Buoyant Density ◽  
Rich Region ◽  
Keratan Sulphate ◽  
Core Proteins ◽  
Lower Mobility ◽  
Cartilage Proteoglycans

Intermediary gel immunoelectrophoresis was used to show that purified aggregating cartilage proteoglycans from 2-year-old steers contain two distinct populations of molecules and that only one of these is immunologically related to non-aggregating cartilage proteoglycans. The two types of aggregating proteoglycans were purified by density-gradient centrifugation in 3.5M-CsCl/4M-guanidinium chloride and separated by zonal rate centrifugation in sucrose gradients. The higher-buoyant-density faster-sedimenting proteoglycan represented 43% of the proteoglycans in the extract. It had a weight-average Mr of 3.5 × 10(6), did not contain a well-defined keratan sulphate-rich region, had a quantitatively dominant chondroitin sulphate-rich region and contained 5.9% protein and 23% hexosamine. The lower-buoyant-density, more slowly sedimenting, proteoglycan represented 15% of the proteoglycans in the extract. It had a weight-average Mr of 1.3 × 10(6), contained both the keratan sulphate-rich and the chondroitin sulphate-rich regions and contained 7.3% protein and 23% hexosamine. Each of the proteoglycan preparations showed only one band on agarose/polyacrylamide-gel electrophoresis. The larger proteoglycan had a lower mobility than the smaller. The distribution of chondroitin sulphate chains along the chondroitin sulphate-rich region was similar for the two types of proteoglycans. The somewhat larger chondroitin sulphate chains of the larger proteoglycan could not alone account for the larger size of the proteoglycan. Peptide patterns after trypsin digestion of the proteoglycans showed great similarities, although the presence of a few peptides not shared by both populations indicates that the core proteins are partially different.

Effect of external Ca2+ concentration on stretch-augmented natriuretic peptide secretion by rat atria

1991 ◽  
Vol 260 (4) ◽  
pp. C756-C762 ◽  
Author(s):  
E. Page ◽  
J. Upshaw-Earley ◽  
G. E. Goings ◽  
D. A. Hanck
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Natriuretic Peptide ◽  
Time Course ◽  
Rate Coefficient ◽  
Time Dependent ◽  
Dependent Manner ◽  
Dependent Inactivation ◽  
Long Time ◽  
Peptide Secretion

An in vitro noncontracting rat atrial preparation stretched at 37 degrees C by a distending pressure of 5.1 mmHg was used to examine effects of external Ca2+ concentration ([Ca2+]out, 0.05-3.0 mM) on secretion of immunoreactive atrial natriuretic peptide (ANP) in presence of saxitoxin (STX) and in presence or absence of ryanodine. Under these conditions, the time course of the amount (y) of ANP secreted per milligram dry atrium during 44 min could be approximated by a rate coefficient (k) according to the relation y = s[1 - e(-kt)], where s is the maximal amount secreted after a long time (t). Although k, the rate coefficient for stretch-augmented secretion, increased significantly as [Ca2+]out was raised, secretion inactivated progressively in a time- and [Ca2+]out-dependent manner. This time-dependent decrease was not prevented by ryanodine. We conclude that a component of ANP secreted by quiescent atria in vitro is positively modulated by [Ca2+]out and does not require ryanodine-sensitive Ca2+ release from sarcoplasmic reticulum. The [Ca2+]out-sensitive processes underlying time-dependent inactivation of secretion remain undetermined.

Abnormal 45Ca Fluxes in Dispersed Submandibular Acini of Rats Treated with Reserpine

1987 ◽  
Vol 66 (8) ◽  
pp. 1294-1299 ◽  
Author(s):  
R.M. Müller ◽  
J.R. Martinez
Keyword(s):  
Time Course ◽  
Chronic Treatment ◽  
Tracer Uptake ◽  
Time Dependent ◽  
Coupling Mechanism ◽  
Dependent Manner ◽  
Isotopic Tracer ◽  
Stimulus Response ◽  
Ca Uptake ◽  
Submandibular Acini

The uptake and efflux of the isotopic tracer 45Ca were compared in dispersed submandibular acini of both control rats and rats treated with seven daily doses of reserpine (0.5 mglkg, i.p.). Tracer uptake occurred in a time-dependent manner in both types of acini and reached 8.4 ± 0.2 and 8.0 ± 0.2 pmol/mg protein, respectively, in acini from control and treated animals after 60 min of incubation. Uptake of tracer was 2.35 nmol/mg DNA in control cells and 4 nmol/mg DNA in cells from treated rats at 60 min. 45Ca uptake (per mg protein) was enhanced in control acini 48% by 20 μmol/L epinephrine: 38% by 50 μmol/L carbachol; and 23% by 10 μmol/L isoproterenol. A similar order of potency was observed when uptake was expressed per mg DNA. In acini from reserpine-treated rats, 45Ca uptake (per mg protein) was increased 53% by epinephrine, 39% by isoproterenol, and only 8% by carbachol. The same enhanced effect of isoproterenol and lack of effect of carbachol were observed when uptake was calculated per mg DNA. In the absence of secretagogue, efflux of 45Ca from tracer-pre-loaded acini was larger in acini from reserpine-treated rats (53%) than in control acini (36%). Whether expressed in terms of mg protein or mg DNA, this efflux was increased in control acini 35% by epinephrine, from 25 to 28% by isoproterenol, and 17% by carbachol. In acini of reserpine-treated rats, epinephrine increased 45Ca efflux 20%, isoproterenol from 25 to 28%, and carbachol from 14 to 15%. The time course of epinephrine- and isoproterenol-induced efflux was also different from that in control cells. Thus, chronic treatment with reserpine altered uptake and efflux of 45Ca in rat submandibular acini. This suggests alterations in secretagogue-sensitive Ca++ pools or gating mechanisms and is likely to underlie disturbances in the Ca++-mediated events of the stimulus-response coupling mechanism, such as fluid, electrolyte, and protein secretion.

scholarly journals Temporal Splicing Switches in Elements of the TNF-Pathway Identified by Computational Analysis of Transcriptome Data for Human Cell Lines

2019 ◽  
Vol 20 (5) ◽  
pp. 1182 ◽  
Author(s):  
Nikolai Genov ◽  
Alireza Basti ◽  
Mónica Abreu ◽  
Angela Relógio
Keyword(s):  
Alternative Splicing ◽  
Cell Lines ◽  
Time Course ◽  
Stage Iv ◽  
Time Dependent ◽  
Aberrant Splice ◽  
Dependent Manner ◽  
Sequencing Data ◽  
Cellular Processes ◽  
Hodgkin Lymphoma Cell

Alternative splicing plays an important role in numerous cellular processes and aberrant splice decisions are associated with cancer. Although some studies point to a regulation of alternative splicing and its effector mechanisms in a time-dependent manner, the extent and consequences of such a regulation remains poorly understood. In the present work, we investigated the time-dependent production of isoforms in two Hodgkin lymphoma cell lines of different progression stages (HD-MY-Z, stage IIIb and L-1236, stage IV) compared to a B lymphoblastoid cell line (LCL-HO) with a focus on tumour necrosis factor (TNF) pathway-related elements. For this, we used newly generated time-course RNA-sequencing data from the mentioned cell lines and applied a computational pipeline to identify genes with isoform-switching behaviour in time. We analysed the temporal profiles of the identified events and evaluated in detail the potential functional implications of alterations in isoform expression for the selected top-switching genes. Our data indicate that elements within the TNF pathway undergo a time-dependent variation in isoform production with a putative impact on cell migration, proliferation and apoptosis. These include the genes TRAF1, TNFRSF12A and NFKB2. Our results point to a role of temporal alternative splicing in isoform production, which may alter the outcome of the TNF pathway and impact on tumorigenesis.

scholarly journals Autophagy Protects Renal Tubular Cells Against Ischemia / Reperfusion Injury in a Time-Dependent Manner

2015 ◽  
Vol 36 (1) ◽  
pp. 285-298 ◽  
Author(s):  
Xuejing Guan ◽  
Yingying Qian ◽  
Yue Shen ◽  
Lulu Zhang ◽  
Yi Du ◽  
...  
Keyword(s):  
Cell Apoptosis ◽  
Time Course ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Time Dependent ◽  
Dependent Manner ◽  
Tubular Cells ◽  
Renal Tubular Cells ◽  
Renal Tubular

Background/Aims: Autophagy is a dynamic catabolic process that maintains cellular homeostasis. Whether it plays a role in promoting cell survival or cell death in the process of renal ischemia/reperfusion (I/R) remains controversial, partly because renal autophagy is usually examined at a certain time point. Therefore, monitoring of the whole time course of autophagy and apoptosis may help better understand the role of autophagy in renal I/R. Methods: Autophagy and apoptosis were detected after mice were subjected to bilateral renal ischemia followed by 0-h to 7-day reperfusion, exposure of TCMK-1 cells to 24-h hypoxia, and 2 to 24-h reoxygenation. The effect of autophagy on apoptosis was assessed in the presence of autophagy inhibitor 3-methyladenine (3-MA) and autophagy activator rapamycin. Results: Earlier than apoptosis, autophagy increased from 2-h reperfusion, reached the maximum at day 2, and then began declining from day 3 when renal damage had nearly recovered to normal. Exposure to 24-h hypoxia induced autophagy markedly, but it decreased drastically after 4 and 8-h reoxygenation, which was accompanied with increased cell apoptosis. Inhibition of autophagy with 3-MA increased the apoptosis of renal tubular cells during I/R in vivo and hypoxia/reoxygenation (H/R) in vitro. In contrast, activation of autophagy by rapamycin significantly alleviated renal tissue damage and tubular cell apoptosis in the two models. Conclusion: Autophagy was induced in a time-dependent manner and occurred earlier than the onset of cell apoptosis as an early response that played a renoprotective role during renal I/R and cell H/R. Up-regulation of autophagy may prove to be a potential strategy for the treatment of acute kidney injury.

Time Course and Magnitude of Movement-Related Gating of Tactile Detection in Humans. I. Importance of Stimulus Location

1998 ◽  
Vol 79 (2) ◽  
pp. 947-963 ◽  
Author(s):  
Stephan R. Williams ◽  
Jafar Shenasa ◽  
C. Elaine Chapman
Keyword(s):  
Time Course ◽  
Human Subjects ◽  
Stimulus Location ◽  
The Body ◽  
Time Dependent ◽  
Emg Activity ◽  
Dependent Manner ◽  
Perceptual Performance ◽  
Tactile Detection ◽  
The Right

Williams, Stephan R., Jafar Shenasa, and C. Elaine Chapman. Time course and magnitude of movement-related gating of tactile detection in humans. I. Importance of stimulus location. J. Neurophysiol. 79: 947–963, 1998. The time course and spatial extent of movement-related suppression of the detection of weak electrical stimuli (intensity, 90% detected at rest) was determined in 118 experiments carried out in 47 human subjects. Subjects were trained to perform a rapid abduction of the right index finger (D2) in response to a visual cue. Stimulus timing was calculated relative to the onset of movement and the onset of electromyographic (EMG) activity. Electrical stimulation was delivered to 10 different sites on the body, including sites on the limb performing the movement (D2, D5, hand, forearm and arm) as well as several distant sites (contralateral arm, ipsilateral leg). Detection of stimuli applied to the moving digit diminished significantly and in a time-dependent manner, with the first significant decrease occurring 120 ms before movement onset and 70 ms before the onset of EMG activity. Movement-related and time-dependent effects were obtained at all stimulation sites on the homolateral arm as well as the adjacent trunk. A pronounced spatiotemporal gradient was observed: the magnitude of the movement-related decrease in detectability was greatest and earliest at sites closest to the moving finger and progressively weaker and later at more proximal sites. When stimuli were applied to the distant sites, only a small (∼10%), non-time–dependent decrease was observed during movement trials. A simple model of perceptual performance adequately described the results, providing insight into the distribution of movement-related inhibitory controls within the CNS.

scholarly journals Extraction and characterization of proteoglycan from human meniscus

1980 ◽  
Vol 185 (3) ◽  
pp. 705-713 ◽  
Author(s):  
D McNicol ◽  
P J Roughley
Keyword(s):  
Chondroitin Sulphate ◽  
Specific Interaction ◽  
Specific Area ◽  
Human Articular Cartilage ◽  
Tissue Concentrations ◽  
Keratan Sulphate ◽  
Cartilage Proteoglycan ◽  
Age Related ◽  
Core Proteins

This study consists of (1) the extraction of proteoglycan from the human meniscus under dissociative conditions, (2) an investigation of the changes that occur in the abundance and structure of this proteoglycan with age and (3) a comparison of these findings with those for human articular-cartilage proteoglycan. Adult meniscus was found to possess proteoglycan molecules of similar size and glycosaminoglycan content to those present in cartilage, although tissue concentrations were considerably lower. In addition, age-related changes, with respect to the occurrence of keratan sulphate and the sulphation of chondroitin sulphate chains, were common to both tissues. The presence of aggregated proteoglycan was demonstrated, although specific interaction with hyaluronic acid was not conclusively shown biochemically. Differences were, however, noted in the structure of the proteoglycan between the two tissues: dermatan sulphate was found in the meniscus proteoglycan preparation and the core proteins exhibited some dissimilarities. A proteoglycan structure of this type would be compatible with its participation in meniscus elasticity, especially as the material is localized in a specific area.

scholarly journals TIME COURSE STUDY OF COMBINED N-ACETYL-P-AMINOPHENOL AND DICLOPHENAC INDUCED-HEPATOTOXICITY AND OXIDATIVE STRESS IN WISTAR RATS

2021 ◽  
Vol 46 (2) ◽  
Author(s):  
O. A Dosumu ◽  
D. I. Akinloye ◽  
O. B. Onunkwor ◽  
F. C. Thomas ◽  
R. A. Adeyemo
Keyword(s):  
Oxidative Stress ◽  
Liver Damage ◽  
Wistar Rats ◽  
Time Course ◽  
Time Dependent ◽  
Control Group ◽  
Gamma Glutamyl Transferase ◽  
Dependent Manner ◽  
Glutamyl Transferase ◽  
And Oxidative Stress

The abuse of combined acetaminophen or N-acetyl-p-aminophenol (APAP) and diclofenac (DIC) due to their analgesics, anti-inflammatory and antipyretic properties is a predominant cause of hepatotoxicity and oxidative stress. This study investigated the time-course effects of APAP, DIC and their combination on biomarkers of hepatic function and oxidative stress in rats. Forty male Wistar rats were randomly divided into four groups of 10 animals each as follows; control (distilled water), APAP only, DIC only and APAP + DIC for 4 weeks. Indices of liver damage (serum ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALP, alkaline phosphatase; GGT, gamma-glutamyl transferase and bilirubin) were measured. Oxidative stress biomarkers (MDA, malondialdehyde; NO, nitric oxide; CAT, Catalase activity; SOD, superoxide dismutase activity; GSH content, reduced glutathione), GR, glutathione reductase, and GST, glutathione-S-transferase) were also determined using spectrophotometric methods. Statistical analysis was done using one-way ANOVA with p < 0.05 considered significant. Acetaminophen and diclofenac caused marked liver damage as noted by time-dependent significant (p < 0.05) increased activities of serum ALT, AST, ALP, GGT, and bilirubin levels as well as significant (p < 0.05) increase in hepatic MDA and NO levels as compared to the control group. Hepatic GSH content, SOD, CAT, GPx, GST and GR activities were decreased significantly (p < 0.05) in all acetaminophen and diclofenac-treated groups compared to normal control in a time-dependent manner. These findings suggest that prolonged administration of diclofenac, acetaminophen or their combination may induce hepatotoxicity, oxidative stress and alteration of hepatic antioxidant status in a time-dependent manner.

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