In vitro labeling of peroxisomal cholesterol with radioactive precursors

1987 ◽  
Vol 7 (11) ◽  
pp. 853-858 ◽  
Author(s):  
Eeva-Liisa Appelkvist
Keyword(s):  
Endoplasmic Reticulum ◽  
Rat Liver ◽  
Cholesterol Synthesis ◽  
Synthetic Process ◽  
Luminal Content ◽  
Detergent Treatment ◽  
Subsequent Incorporation

Peroxisomes isolated from rat liver were incubated with [3H]squalene and [3H]mevalonate and the subsequent incorporation of radioactivity into cholesterol studied. The isolated lipids became labeled after incubation with both precursors. In contrast to findings with microsomes, trypsin and detergent treatment of peroxisomes did not influence the rate of cholesterol synthesis. In addition, the luminal content of peroxisomes could alone mediate this synthetic process. Upon treatment of rats with various inducers of peroxisomes and of the endoplasmic reticulum, as well as upon feeding with cholesterol and cholestyramine, large differences in the pattern of in vitro incorporation of [3H]mevalonate into the cholesterol of peroxisomes and microsomes were observed. Injection of this precursor also resulted in high initial labeling of peroxisomal cholesterol in vivo. These experiments indicate that cholesterol synthesis may also occur in peroxisomes.

Effects of (+)-Catechin in vitro and in vivo on Disturbances Produced in Rat Liver Endoplasmic Reticulum by Carbon Tetrachloride

1977 ◽  
Vol 5 (4) ◽  
pp. 1029-1032 ◽  
Author(s):  
OLIVIERO DANNI ◽  
BARBARA C. SAWYER ◽  
TREVOR F. SLATER
Keyword(s):  
Endoplasmic Reticulum ◽  
Carbon Tetrachloride ◽  
Rat Liver

scholarly journals Phospholipid synthesis in rat liver endoplasmic reticulum after the administration of phenobarbitone and 20-methylcholanthrene

1974 ◽  
Vol 142 (1) ◽  
pp. 19-26 ◽  
Author(s):  
Susan C. Davison ◽  
Eric D. Wills
Keyword(s):  
Endoplasmic Reticulum ◽  
Rat Liver ◽  
Turnover Rate ◽  
Total Phospholipid ◽  
Transient Increase ◽  
Phospholipid Synthesis ◽  
Phosphatidylethanolamine Methyltransferase ◽  
Phosphatidylcholine Synthesis

1. Phenobarbitone injection did not affect the concentration of phospholipids in the liver endoplasmic reticulum, but it increased the rate of incorporation of [32P]orthophosphate into the phospholipids. 20-Methylcholanthrene caused a transient increase in total phospholipid but a decrease in the turnover rate of the phospholipids. 2. Incorporation of [32P]orthophosphate into phosphatidylcholine, compared with that into phosphatidylethanolamine, was increased by phenobarbitone injection but decreased by 20-methylcholanthrene injection. 3. The activity of S-adenosylmethionine–phosphatidylethanolamine methyltransferase increased 12h after phenobarbitone injection, when incorporation of [32P]orthophosphate into phosphatidylcholine was a maximum, but at other times, and after 20-methylcholanthrene injection, the activity of the enzyme did not correlate with the rate of phosphatidylcholine synthesis. 4. [14C]Glycerol was incorporated more rapidly into phosphatidylcholine than into phosphatidylethanolamine, whereas [32P]orthophosphate and [14C]ethanolamine were incorporated more rapidly into phosphatidylethanolamine than into phosphatidylcholine. 5. Incorporation of [32P]orthophosphate into phosphatidylethanolamine of liver slices incubated in vitro was much more rapid than into phosphatidylcholine, and incorporation into phosphatidylcholine was markedly stimulated by addition of methionine to the medium. Changes in the incorporation of [32P]orthophosphate into phospholipids observed in vivo after injection of phenobarbitone or methylcholanthrene could not be reproduced in slices incubated in vitro. 6. It is concluded that phenobarbitone injection causes an increased rate of turnover of total phospholipids in the endoplasmic reticulum and an increased conversion of phosphatidylethanolamine into phosphatidylcholine, whereas 20-methylcholanthrene injection depresses both the turnover rate of total phospholipids and the formation of phosphatidylcholine.

scholarly journals Role of membrane-bound and free polyribosomes in the synthesis of cytochrome c in rat liver

1974 ◽  
Vol 140 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Néstor F. González-Cadavid ◽  
Carmen Sáez De Córdova
Keyword(s):  
Endoplasmic Reticulum ◽  
Cytochrome C ◽  
Rat Liver ◽  
Cell Structure ◽  
Polyacrylamide Gel Electrophoresis ◽  
Mitochondrial Protein ◽  
Sodium Dodecyl ◽  
Membrane Bound

The functional distinction of membrane-bound and free polyribosomes for the synthesis of exportable and non-exportable proteins respectively is not so strict as was initially thought, and it was therefore decided to investigate their relative contribution to the elaboration of an internal protein integrated into a cell structure. Cytochrome c was chosen as an example of a soluble mitochondrial protein, and the incorporation of [14C]leucine and δ-amino[14C]laevulinate into the molecule was studied by using different ribosomal preparations from regenerating rat liver. A new procedure was devised for the purification of cytochrome c, based on ion-exchange chromatography combined with sodium dodecyl sulphate–polyacrylamide-gel electrophoresis. In spite of cytochrome c being a non-exportable protein, the membrane-bound polyribosomes were at least as active as the free ribosomes in the synthesis in vitro of the apoprotein and the haem moiety. The detergent-treated ribosomes could also effect the synthesis of cytochrome c, although at a lower rate. Since in liver more than two-thirds of the ribosomes are bound to the endoplasmic-reticulum membranes, it is considered that in vivo they are responsible for the synthesis of most of the cytochrome c content of the cell. This suggests that in secretory tissues the endoplasmic reticulum plays a predominant role in mitochondrial biogenesis, although free ribosomes may participate in the partial turnover of some parts of the organelle. The hypothesis on the functional specialization of the different kinds of ribosomes was therefore modified to account for their parallel intervention in the synthesis of proteins associated with membranous structures.

In vitro and in vivo suppression of growth of rat liver epithelial tumor cells by antisense oligonucleotide against protein kinase C-alpha

2000 ◽  
Vol 33 (4) ◽  
pp. 601-608 ◽  
Author(s):  
Shwu-Bin Lin ◽  
Li-Ching Wu ◽  
Siao-Ling Huang ◽  
Hui-Lun Hsu ◽  
Sung-Hwa Hsieh ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tumor Cells ◽  
Rat Liver ◽  
Antisense Oligonucleotide ◽  
Epithelial Tumor ◽  
Kinase C ◽  
Epithelial Tumor Cells

Effect of X-irradiation on gene expression of rat liver chemokines: in vivo and in vitro studies

2008 ◽  
Vol 46 (01) ◽  
Author(s):  
F Moriconi ◽  
H Christiansen ◽  
H Christiansen ◽  
N Sheikh ◽  
J Dudas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rat Liver ◽  
In Vitro Studies ◽  
X Irradiation

Targeting Matrix Metalloproteinases in Atherosclerosis and Cardiovascular Dysfunction

2019 ◽  
Vol 70 (2) ◽  
pp. 718-720
Author(s):  
Lucia Corina Dima-Cozma ◽  
Sebastian Cozma ◽  
Delia Hinganu ◽  
Cristina Mihaela Ghiciuc ◽  
Florin Mitu
Keyword(s):  
Smooth Muscle ◽  
Matrix Metalloproteinases ◽  
Cholesterol Synthesis ◽  
Balloon Dilation ◽  
Aortic Aneurysms ◽  
Arterial Lesions ◽  
Smooth Muscle Cell Migration ◽  
And Migration

Matrix metalloproteinases (MMPs) are the primary mediators of extracellular remodeling and their properties are useful in diagnostic evaluation and treatment. They are zinc-dependent proteases. MMPs have been involved in the mechanisms of atherosclerosis in various arterial areas, ischemic heart disease and myocardial infarction, atrial fibrillation and aortic aneurysms. Recently, MMP9 has been implicated in dyslipidemia and cholesterol synthesis by the liver. Increased MMP expression and activity has been associated with neointimal arterial lesions and migration of smooth muscle cells after arterial balloon dilation, while MMP inhibition decreases smooth muscle cell migration in vivo and in vitro.

scholarly journals Dehydrodiisoeugenol inhibits colorectal cancer growth by endoplasmic reticulum stress-induced autophagic pathways

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Changhong Li ◽  
Kui Zhang ◽  
Guangzhao Pan ◽  
Haoyan Ji ◽  
Chongyang Li ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Endoplasmic Reticulum ◽  
Cell Growth ◽  
Er Stress ◽  
Cancer Cells ◽  
Tumor Xenograft ◽  
Anticancer Activities ◽  
Colorectal Cancer Cells

Abstract Background Dehydrodiisoeugenol (DEH), a novel lignan component extracted from nutmeg, which is the seed of Myristica fragrans Houtt, displays noticeable anti-inflammatory and anti-allergic effects in digestive system diseases. However, the mechanism of its anticancer activity in gastrointestinal cancer remains to be investigated. Methods In this study, the anticancer effect of DEH on human colorectal cancer and its underlying mechanism were evaluated. Assays including MTT, EdU, Plate clone formation, Soft agar, Flow cytometry, Electron microscopy, Immunofluorescence and Western blotting were used in vitro. The CDX and PDX tumor xenograft models were used in vivo. Results Our findings indicated that treatment with DEH arrested the cell cycle of colorectal cancer cells at the G1/S phase, leading to significant inhibition in cell growth. Moreover, DEH induced strong cellular autophagy, which could be inhibited through autophagic inhibitors, with a rction in the DEH-induced inhibition of cell growth in colorectal cancer cells. Further analysis indicated that DEH also induced endoplasmic reticulum (ER) stress and subsequently stimulated autophagy through the activation of PERK/eIF2α and IRE1α/XBP-1 s/CHOP pathways. Knockdown of PERK or IRE1α significantly decreased DEH-induced autophagy and retrieved cell viability in cells treated with DEH. Furthermore, DEH also exhibited significant anticancer activities in the CDX- and PDX-models. Conclusions Collectively, our studies strongly suggest that DEH might be a potential anticancer agent against colorectal cancer by activating ER stress-induced inhibition of autophagy.

Dietary (-)-epicatechin mitigates high fat-induced apoptosis, oxidative and endoplasmic reticulum stress in pancreatic β-cells both in vivo and in vitro

2021 ◽  
Vol 165 ◽  
pp. 44
Author(s):  
Eleonora Cremonini ◽  
Maëlys Rouget ◽  
Solenne Arredi ◽  
Charlotte Devulder-Mercier ◽  
Robin Cellier ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
High Fat ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Induced Apoptosis
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