scholarly journals NUCLEOLAR-DERIVED RIBONUCLEIC ACID IN CHROMOSOMES, NUCLEAR SAP, AND CYTOPLASM OF CHIRONOMUS TENTANS SALIVARY GLAND CELLS

1971 ◽  
Vol 51 (2) ◽  
pp. 355-368 ◽  
Author(s):  
U. Ringborg ◽  
L. Rydlander
Keyword(s):  
Molecular Weight ◽  
Salivary Gland ◽  
High Molecular Weight ◽  
Ribosomal Rna ◽  
Chironomus Tentans ◽  
Gland Cells ◽  
Composite Gels ◽  
Salivary Gland Cells

The distribution of monodisperse high molecular weight RNA (38, 30, 28, 23, and 18S RNA) was studied in the salivary gland cells of Chironomus tentans. RNA labeled in vitro and in vivo with tritiated cytidine and uridine was isolated from microdissected nucleoli, chromosomes, nuclear sap, and cytoplasm and analyzed by electrophoresis on agarose-acrylamide composite gels. As shown earlier, the nucleoli contain labeled 38, 30, and 23S RNA. In the chromosomes, labeled 18S RNA was found in addition to the 30 and 23S RNA previously reported. The nuclear sap contains labeled 30 and 18S RNA, and the cytoplasm labeled 28 and 18S RNA. On the basis of the present and earlier analyses, it was concluded that the chromosomal monodisperse high molecular weight RNA fractions (a) show a genuine chromosomal localization and are not due to unspecific contamination, (b) are not artefacts caused by in vitro conditions, but are present also in vivo, and (c) are very likely related to nucleolar and cytoplasmic (pre)ribosomal RNA. The 30 and 23S RNA components are likely to be precursors to 28 and 18S ribosomal RNA. The order of appearance of the monodisperse high molecular weight RNA fractions in the nucleus is in turn and order: (a) nucleolus, (b) chromosomes, and (c) nuclear sap. Since both 23 and 18S RNA are present in the chromosomes, the conversion to 18S RNA may take place there. On the other hand, 30S RNA is only found in the nucleus while 28S RNA can only be detected in the cytoplasm, suggesting that this conversion takes place in connection with the exit of the molecule from the nucleus.

scholarly journals Mobility restriction in vivo of the heavy ribosomal subunit in a secretory cell.

1976 ◽  
Vol 70 (3) ◽  
pp. 573-580 ◽  
Author(s):  
U Lönn ◽  
J E Edström
Keyword(s):  
Endoplasmic Reticulum ◽  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Ribosomal Subunit ◽  
Chironomus Tentans ◽  
Salivary Gland Cells ◽  
Unique Parameter ◽  
Labeled Rna

Analysis in insect (Chironomus tentans) salivary gland cells of labeled RNA as a function of time after precursor injection and its distance to the nuclear membrane, cytoplasmic zone analysis, could previously be used to demonstrate the presence of short-lasting gradients in newly labeled ribosomal RNA. Since the gradients were sensitive to puromycin, they are likely to be a result of diffusion restriction due to an engagement of the subunits into polysomes. In the present paper the possibility was explored of recording gradients that were caused by labeled subunits in puromycin-resistant associations, which, in all probability, involve the endoplasmic reticulum. It was found that labeled 28 S and 5 S RNA but not 18 S RNA were present in radioactivity gradients lasting for at least 2 days but less than 6 days. The gradients also remained during inhibition of RNA synthesis by actinomycin, and they were completely resistant to puromycin whether given in vivo or in vitro. The semipermanent gradients formed fhere offer a unique parameter for the in vivo study of conditions for formation and maintenance of heavy subunits in puromycin-resistant bonds. An explanation for these and previous results is that the light subunit, although restricted in movement by engagement to polysomes, is nevertheless free to exchange and spread between rounds of translation, whereas at least part of the heavy subunit population is bound to the endoplasmic reticulum and less free to spread. These results offer a good in vivo correlate to previous results on in vitro exchangeability of subunits.

In vitro and in vivo imaging of intracellular Ca2+ responses in salivary gland cells

2015 ◽  
Vol 57 (2) ◽  
pp. 69-75 ◽  
Author(s):  
Akihiro Nezu ◽  
Takao Morita ◽  
Akihiko Tanimura
Keyword(s):  
Salivary Gland ◽  
In Vivo Imaging ◽  
Gland Cells ◽  
Salivary Gland Cells

scholarly journals EFFECTS OF α-AMANITIN ON IN VITRO LABELING OF RNA FROM DEFINED NUCLEAR COMPONENTS IN SALIVARY GLAND CELLS FROM CHIRONOMUS TENTANS

1972 ◽  
Vol 53 (2) ◽  
pp. 523-531 ◽  
Author(s):  
E. Egyházi ◽  
B. D'Monte ◽  
J.-E. Edström
Keyword(s):  
Salivary Gland ◽  
Normal Band ◽  
Chironomus Tentans ◽  
Gland Cells ◽  
Large Size ◽  
Rna Labeling ◽  
Salivary Gland Cells ◽  
Rna Formation ◽  
18 S Ribosomal Rna

The effect of α-amanitin on nucleoside labeling of RNA in nucleoli, chromosomes, nuclear sap, and cytoplasm from Chironomus tentans salivary gland cells was investigated by radioautography and gel electrophoresis. Preribosomal RNA formation and processing in the nucleolus was not measurably influenced by the drug, and both 28 S and 18 S ribosomal RNA were transferred to the cytoplasm. In the chromosomes the heterogeneous RNA labeling was completely inhibited for the large size range (above 45–50 S) and partially for the low range. The labeling of 4–5 S chromosomal RNA was only moderately reduced. Most of the chromosomes showed radioautographically a disappearance of the normal band pattern, but some retained a pattern of weakly labeled bands. The electrophoretic results for the nuclear sap paralleled those for the chromosomes. The effect of α-amanitin on RNA labeling in these cells is similar but not identical to that of the substituted benzimidazole 5,6-dichloro-1(ß-D-ribofuranosyl) benzimidazole (DRB).

scholarly journals Non-Lethal Concentration of MeHg Causes Marked Responses in the DNA Repair, Integrity, and Replication Pathways in the Exposed Human Salivary Gland Cell Line

2021 ◽  
Vol 12 ◽  
Author(s):  
Lygia Sega Nogueira ◽  
Carolina P. Vasconcelos ◽  
Jessica Rodrigues Plaça ◽  
Geovanni Pereira Mitre ◽  
Leonardo Oliveira Bittencourt ◽  
...  
Keyword(s):  
Dna Repair ◽  
Salivary Gland ◽  
Cell Line ◽  
Gland Cell ◽  
Salivary Gland Cell ◽  
Human Salivary Gland ◽  
Gland Cells ◽  
Salivary Gland Cells

In Brazilian northern Amazon, communities are potentially exposed and vulnerable to methylmercury (MeHg) toxicity through the vast ingestion of fish. In vivo and in vitro studies demonstrated that the salivary glands as a susceptible organ to this potent environmental pollutant, reporting alterations on physiological, biochemical, and proteomic parameters. However, the alterations caused by MeHg on the gene expression of the exposed human salivary gland cells are still unknown. Therefore, the goal was to perform the transcriptome profile of the human salivary gland cell line after exposure to MeHg, using the microarray technique and posterior bioinformatics analysis. The cell exposure was performed using 2.5 µM MeHg. A previously published study demonstrated that this concentration belongs to a range of concentrations that caused biochemical and metabolic alterations in this linage. As a result, the MeHg exposure did not cause lethality in the human salivary gland cells line but was able to alter the expression of 155 genes. Downregulated genes (15) are entirety relating to the cell metabolism impairment, and according to KEGG analysis, they belong to the glycosphingolipid (GSL) biosynthesis pathway. On the other hand, most of the 140 upregulated genes were related to cell-cycle progression, DNA repair, and replication pathway, or cellular defenses through the GSH basal metabolism. These genomic changes revealed the effort to the cell to maintain physiological and genomic stability to avoid cell death, being in accordance with the nonlethality in the toxicity test. Last, the results support in-depth studies on nonlethal MeHg concentrations for biomarkers identification that interpret transcriptomics data in toxicological tests serving as an early alert of physiological changes in vitro biological models.

Microinjection of anti-topoisomerase I immunoglobulin G into nuclei of Chironomus tentans salivary gland cells leads to blockage of transcription elongation

1987 ◽  
Vol 7 (12) ◽  
pp. 4308-4316
Author(s):  
E Egyházi ◽  
E Durban
Keyword(s):  
Salivary Gland ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Immunoglobulin G ◽  
Topoisomerase I ◽  
Chironomus Tentans ◽  
Balbiani Ring ◽  
Gland Cells ◽  
Salivary Gland Cells ◽  
Transcriptional Process

Purified anti-topoisomerase I immunoglobulin G (IgG) was microinjected into nuclei of Chironomus tentans salivary gland cells, and the effect on DNA transcription was investigated. Synthesis of nucleolar preribosomal 38S RNA by RNA polymerase I and of chromosomal Balbiani ring RNA by RNA polymerase II was inhibited by about 80%. The inhibitory action of anti-topoisomerase I IgG could be reversed by the addition of exogenous topoisomerase I. Anti-topoisomerase I IgG had less effect on RNA polymerase II-promoted activity of other less efficiently transcribing heterogeneous nuclear RNA genes. The pattern of inhibition of growing nascent Balbiani ring chains indicated that the transcriptional process was interrupted at the level of chain elongation. The highly decondensed state of active Balbiani ring chromatin, however, remained unaffected after injection of topoisomerase I antibodies. These data are consistent with the interpretation that topoisomerase I is an essential component in the transcriptional process but not in the maintenance of the decondensed state of active chromatin.

In Vitro and in Vivo Antigen-Induced Release of High-Molecular Weight Neutrophil Chemotactic Activity from Human Nasal Tissue

1988 ◽  
Vol 2 (1) ◽  
pp. 7-11 ◽  
Author(s):  
T. Nagakura ◽  
T. Onda ◽  
Y. likura ◽  
T. Endo ◽  
H. Nagakura ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Nasal Polyps ◽  
Gel Filtration ◽  
Chemotactic Activity ◽  
Nasal Tissue ◽  
Nasal Secretions ◽  
Neutrophil Chemotactic Activity

High molecular weight neutrophil chemotactic activity has been identified in resected human nasal polyps, inferior turbinates, and nasal secretions following antigen challenge. The estimated molecular weight, by gel filtration chromatography, was approximately 600,000. However, a heterogeneity of molecular weight in some patients was recognized. Our results suggest a possible role for high molecular weight-neutrophil chemotactic activity in the pathogenesis of hypersensitivity in the human nasal cavity.

scholarly journals An Assessment of the Bioactivity of Coffee Silverskin Melanoidins

Foods ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 68 ◽  
Author(s):  
Silvia Tores de la Cruz ◽  
Amaia Iriondo-DeHond ◽  
Teresa Herrera ◽  
Yolanda Lopez-Tofiño ◽  
Carlos Galvez-Robleño ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Dietary Fiber ◽  
High Molecular Weight ◽  
Research Work ◽  
Weight Fraction ◽  
High Molecular Weight Fraction ◽  
Total Dietary Fiber ◽  
Coffee Silverskin

Melanoidins present in coffee silverskin, the only by-product of the roasting process, are formed via the Maillard reaction. The exact structure, biological properties, and mechanism of action of coffee silverskin melanoidins, remain unknown. This research work aimed to contribute to this novel knowledge. To achieve this goal, melanoidins were obtained from an aqueous extract of Arabica coffee silverskin (WO2013004873A1) and was isolated through ultrafiltration (>10 kDa). The isolation protocol was optimized and the chemical composition of the high molecular weight fraction (>10 kDa) was evaluated, by analyzing the content of protein, caffeine, chlorogenic acid, and the total dietary fiber. In addition, the structural analysis was performed by infrared spectroscopy. Antioxidant properties were studied in vitro and the fiber effect was studied in vivo, in healthy male Wistar rats. Melanoidins were administered to animals in the drinking water at a dose of 1 g/kg. At the fourth week of treatment, gastrointestinal motility was evaluated through non-invasive radiographic means. In conclusion, the isolation process was effective in obtaining a high molecular weight fraction, composed mainly of dietary fiber, including melanoidins, with in vitro antioxidant capacity and in vivo dietary fiber effects.

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