scholarly journals Effect of insulin on low-density-lipoprotein metabolism in human lymphocytes in vitro

1986 ◽  
Vol 233 (2) ◽  
pp. 565-570 ◽  
Author(s):  
S Suresh ◽  
V Warty ◽  
M Virji ◽  
A Sanghvi
Keyword(s):  
Cholesterol Synthesis ◽  
Human Peripheral Blood ◽  
Reductase Activity ◽  
Human Lymphocytes ◽  
Density Lipoprotein ◽  
Inhibitory Effect ◽  
Peripheral Blood Lymphocytes ◽  
Cell Surface Receptor ◽  
Low Density

The metabolism of low-density lipoproteins (LDL) in vitro in the presence of insulin was studied in freshly isolated human peripheral-blood lymphocytes. Insulin appeared to decrease the binding affinity of 125I-LDL to its cell-surface receptor, without any change in apparent Vmax or in the number of LDL receptors. As a consequence, the absolute amounts of 125I-LDL internalized and degraded were lower in the presence of insulin than in its abscence, although the fraction of internalized 125I-LDL degraded in either instance was quite similar. 3-Hydroxy-3-methylglutaryl-CoA reductase activity, and hence cholesterol synthesis, were stimulated by insulin. This effect of insulin was independent of the inhibitory effect of LDL on cholesterol synthesis. At the same time, acid cholesterol esterase and acyl-CoA: cholesterol O-acetyltransferase activities were lower in cells incubated with insulin than in controls. The net effect of these metabolic alterations seems to be that cells accumulate greater quantities of free and esterified cholesterol when treated with insulin.

scholarly journals Sagunja-Tang Improves Lipid Related Disease in a Postmenopausal Rat Model and HepG2 Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Hiroe Go ◽  
Jin Ah Ryuk ◽  
Hye Won Lee ◽  
In Sil Park ◽  
Ki-Jung Kil ◽  
...  
Keyword(s):  
Lipid Accumulation ◽  
Hepg2 Cells ◽  
Cholesterol Synthesis ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Protein Levels ◽  
Related Disease

The present study was conducted to investigate the effect of Sagunja-tang on the lipid related disease in a rat model of menopausal hyperlipidemia and lipid accumulation in methyl-β-cyclodextrin-induced HepG2 cells. Inin vivostudy using menopausal hyperlipidemia rats, Sagunja-tang reduced retroperitoneal and perirenal fat, serum lipids, atherogenic index, cardiac risk factor, media thickness, and nonalcoholic steatohepatitis score, when compared to menopausal hyperlipidemia control rats. In HepG2 cells, Sagunja-tang significantly decreased the lipid accumulation, total cholesterol levels, and low-density/very-low-density lipoprotein levels. Moreover, Sagunja-tang reversed the methyl-β-cyclodextrin-induced decrease in the protein levels of critical molecule involved in cholesterol synthesis, sterol regulatory element binding protein-2, and low-density lipoprotein receptor and inhibited protein levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase as well as activity. Phosphorylation level of AMP-activated protein kinase was stimulated by Sagunja-tang. These results suggest that Sagunja-tang has effect on inhibiting hepatic lipid accumulation through regulation of cholesterol synthesis and AMPK activityin vitro. These observations support the idea that Sagunja-tang is bioavailable bothin vivoandin vitroand could be developed as a preventive and therapeutic agent of hyperlipidemia in postmenopausal females.

scholarly journals Chronic exogenous hyperinsulinaemia does not modify the acute inhibitory effect of insulin on the secretion of very-low-density lipoprotein triacylglycerol and apolipoprotein B in primary cultures of rat hepatocytes

1996 ◽  
Vol 314 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Catherine S. BOURGEOIS ◽  
David WIGGINS ◽  
Geoffrey F. GIBBONS
Keyword(s):  
Apolipoprotein B ◽  
Low Density Lipoprotein ◽  
Primary Cultures ◽  
Density Lipoprotein ◽  
Inhibitory Effect ◽  
Cell Protein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Plasma Insulin Concentration

Male Wistar rats were fitted with subcutaneous osmotic minipumps that delivered insulin at a constant rate of 0.20 i.u./h for 7 days. This treatment raised the plasma insulin concentration from 31±4 to 201±64 μ-i.u./ml. Hepatocytes prepared from the hyperinsulinaemic animals secreted very-low-density lipoprotein (VLDL) triacylglycerol (TAG) at a higher rate (172±21 μg per 24 h per mg cell protein) than did those from sham-operated controls (109±12 μg per 24 h per mg) (P < 0.05). However, chronic exogenous hyperinsulinaemia had no stimulatory effect on the secretion of VLDL apolipoprotein B (apoB) in derived hepatocytes compared with those from the sham-operated controls (2.32±0.38 compared with 3.09±0.40 μg per 24 h per mg). Hepatocytes from the hyperinsulinaemic rats thus secreted larger VLDL particles as evidenced by the increased TAG:apoB ratio (78.4±13.1 compared with 38.4±7.6; P < 0.05). In hepatocytes from the hyperinsulinaemic rats a larger proportion of the newly synthesized TAG was secreted as VLDL. Hepatocytes from the hyperinsulinaemic and the sham-operated control animals were equally sensitive to the inhibitory effect of insulin added in vitro on the secretion of VLDL TAG. Insulin added in vitro to the culture medium of hepatocytes from hyperinsulinaemic animals significantly decreased the TAG:apoB ratio of the secreted VLDL. This change did not occur in hepatocytes from sham-operated rats. These results suggest that, in vivo, chronic hyperinsulinaemia is not in itself sufficient to desensitize the liver to the acute inhibitory effect of insulin on the secretion of VLDL.

Soluble CD14 Protects Human Lymphocytes from Apoptosis

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2566-2566
Author(s):  
Elizabeth Naparstek ◽  
Benjamin Sredni ◽  
Eti Zigman ◽  
Gali Senyor ◽  
Boris Tartakovsky
Keyword(s):  
Human Peripheral Blood ◽  
Protective Efficacy ◽  
Human Lymphocytes ◽  
Membrane Integrity ◽  
Peripheral Blood Lymphocytes ◽  
Apoptotic Cells ◽  
Soluble Cd14 ◽  
Apoptotic Pathway ◽  
Cell Membrane Integrity

Abstract CD14, a 56 Kd glycoprotein, typically present on myeloid cells, has been traditionally associated with innate immunity and pattern recognition. Recently its membrane bound form has been shown to be involved in apoptosis, as a tethering receptor for apoptotic cells on the surface of phagocytes-in this case with the purpose of removing apoptotic cells, and also as a surface molecule involved in protection from apoptosis of monocytes, neutrophils and recently on enterocytes, challenged with LPS. Our aim was to evaluate the possible involvement of the soluble CD14 in the apoptotic pathway of human lymphocytes. Methods: Freshly obtained human peripheral blood lymphocytes were cultured in vitro with gliotoxin, an apoptotic inducer. Human recombinant CD14 was added to the culture at physiological concentrations (10μg/ml-0.5 μg/ml) and apoptosis was assessed by cell membrane integrity using 7AAD, mitochondrial membrane potential by DiOC6(3) and cytoplasm shrinkage by cell size scatter analysis. Results: Using DiOC6(3) we were able to show that human lymphocytes cultured in the presence of gliotoxin contained 63.8%±21 apoptotic cells, as opposed to 12.2%±11.5 in control cultures. Addition of recombinant human CD14 at a concentration of 10 mg/ml neutralized the apoptotic effect of gliotoxin back to 20.2%±10 (p&lt;0.003). This inhibitory effect was blocked by CD14-specific monoclonal antibodies, but not by control antibodies. We then identified and synthesized the fragment within the CD14 molecule that was responsible for this apoptosis protective effect, and demonstrated its comparable protective efficacy in vitro as shown in figure 1. The figure clearly reveals that this specific peptide, as opposed to the scrambled peptide, protected the lymphocytes form apoptosis, similarly to the full CD14 protein. Same results were obtained using 7AAD and cytoplasm shrinkage. Conclusion: Our data thus suggest that circulating CD14 may play an important role in the prevention of apoptosis of lymphocytes and perhaps of other cells. Figure Figure

scholarly journals Inhibitory Effect onIn VitroLDL Oxidation and HMG Co-A Reductase Activity of the Liquid-Liquid Partitioned Fractions ofHericium erinaceus(Bull.) Persoon (Lion’s Mane Mushroom)

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Mohammad Azizur Rahman ◽  
Noorlidah Abdullah ◽  
Norhaniza Aminudin
Keyword(s):  
Therapeutic Potential ◽  
Reductase Activity ◽  
Antioxidant Properties ◽  
Density Lipoprotein ◽  
Thiobarbituric Acid ◽  
Inhibitory Effect ◽  
Hexane Fraction ◽  
Ldl Oxidation ◽  
Hericium Erinaceus

Oxidation of low-density lipoprotein (LDL) has been strongly suggested as the key factor in the pathogenesis of atherosclerosis. Mushrooms have been implicated in having preventive effects against chronic diseases due especially to their antioxidant properties. In this study,in vitroinhibitory effect ofHericium erinaceuson LDL oxidation and the activity of the cholesterol biosynthetic key enzyme, 3-hydroxy-3-methyl glutaryl coenzyme A (HMG Co-A) reductase, was evaluated using five liquid-liquid solvent fractions consisting of methanol : dichloromethane (M : DCM), hexane (HEX), dichloromethane (DCM), ethyl acetate (EA), and aqueous residue (AQ). The hexane fraction showed the highest inhibition of oxidation of human LDL as reflected by the increased lag time (100 mins) for the formation of conjugated diene (CD) at 1 µg/mL and decreased production (68.28%, IC500.73 mg/mL) of thiobarbituric acid reactive substances (TBARS) at 1 mg/mL. It also mostly inhibited (59.91%) the activity of the HMG Co-A reductase at 10 mg/mL. The GC-MS profiling of the hexane fraction identified the presence of myconutrients:inter alia, ergosterol and linoleic acid. Thus, hexane fraction ofHericium erinaceuswas found to be the most potentin vitroinhibitor of both LDL oxidation and HMG Co-A reductase activity having therapeutic potential for the prevention of oxidative stress-mediated vascular diseases.

scholarly journals Phytohemagglutinin-stimulated normal human peripheral blood lymphocytes in folate-depleted medium: an in vitro model for megaloblastic hemopoiesis

Blood ◽  
1980 ◽  
Vol 55 (5) ◽  
pp. 863-865 ◽  
Author(s):  
RJ Hayman ◽  
MB Van Der Weyden
Keyword(s):  
Peripheral Blood ◽  
Thymidine Incorporation ◽  
Human Peripheral Blood ◽  
Inhibitory Effect ◽  
Peripheral Blood Lymphocytes ◽  
Blood Lymphocytes ◽  
Human Peripheral Blood Lymphocytes ◽  
Normal Human ◽  
Normal Human Peripheral Blood

Abstract Normal human peripheral blood lymphocytes cultured with phytohemagglutinin in folate-free RPMI 1640 medium supplemented with normal human serum exhibit megaloblastic maturation. These changes are accompanied by a decrease in intracellular folate content, and when compared to folate-replete cells, reveal increased 3H-thymidine incorporation into DNA together with a decreased inhibitory effect of deoxyuridine on 3H-thymidine incorporation. This in vitro system of cellular folate deficiency is a convenient model for analysis of biochemical events accompanying megaloblastic maturation.

scholarly journals Cytotoxic, clastogenic and genotoxic effects of cis-tetraammine(oxalato)ruthenium(III) dithionate on human peripheral blood lymphocytes

2020 ◽  
Vol 42 ◽  
pp. e50517
Author(s):  
Manuela da Rocha Matos Rezende ◽  
Vivianne de Souza Velozo-Sá ◽  
Cesar Augusto Sam Tiago Vilanova-Costa ◽  
Elisangela Silveira-Lacerda
Keyword(s):  
Comet Assay ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Low Frequency ◽  
Peripheral Blood Lymphocytes ◽  
Negative Control ◽  
Blood Lymphocytes ◽  
Human Peripheral Blood Lymphocytes

There is a concern about stablishing the clinical risk of drugs used for cancer treatment. In this study, the cytotoxic, clastogenic and genotoxic properties of cis-tetraammine(oxalato)ruthenium(III) dithionite - cis-[Ru(C2O4)(NH3)4]2(S2O6), were evaluated in vitro in human lymphocytes. The mitotic index (MI), chromosomal aberrations (CA) and DNA damage by comet assay were also analyzed. The MTT test revealed that the ruthenium compound showed a slight cytotoxic effect at the highest concentration tested. The IC50 value for the compound after 24 hours of exposure was 185.4 µM. The MI values of human peripheral blood lymphocytes treated with 0.015, 0.15, 1.5 and 150 µM of cis-[Ru(C2O4)(NH3)4]2(S2O6) were 6.1, 3.9, 3.2 and 0.2%, respectively. The lowest concentration, 0.015 µM, did not show any cytotoxic activity. The CA values for the 0.015, 0.15 and 1.5 µM concentrations presented low frequency (1.5, 1.6 and 2.3%, respectively), and did not express clastogenic activity when compared to the negative control, although it was observed clastogenic activity in the highest concentration tested (150 µM). The results obtained by the comet assay suggest that this compound does not present genotoxic activity at lower concentrations. The results show that cis-[Ru(C2O4)(NH3)4]2(S2O6) has no cytotoxic, clastogenic or genotoxic in vitro effects at concentrations less than or equal to 0.015 µM. This information proves as promising in the treatment of cancer and is crucial for future trials.

A Cytogenetic Approach to the Study of Genotoxic Effects of Fungicides: An in Vitro Study in Lymphocyte Cultures with Thiophanate-methyl

1996 ◽  
Vol 24 (4) ◽  
pp. 597-601
Author(s):  
Patrizia Hrelia ◽  
Carmela Fimognari ◽  
Fernanda Vigagni ◽  
Francesca Maffei ◽  
Giorgio Cantelli-Forti
Keyword(s):  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
In Situ Hybridisation ◽  
In Vitro Study ◽  
Peripheral Blood Lymphocytes ◽  
Fluorescence In Situ Hybridisation ◽  
Thiophanate Methyl ◽  
Mechanisms Of Toxicity ◽  
Genetic Level

This study was designed to evaluate the mechanisms of genetic damage by fungicides in cultured human peripheral blood lymphocytes by means of a molecular cytogenetic approach. For example, thiophanate-methyl (30μg/ml-300μg/ml) was shown to significantly induce chromosome aberrations and micronuclei in human lymphocytes cultured in vitro. Fluorescence in situ hybridisation with centromeric DNA probes demonstrated that most micronuclei induced by thiophanate-methyl did not show any centromeric signals, indicating a relatively stronger clastogenic activity. Results obtained with thiophanate-methyl showed that a comprehensive examination of the mechanisms of toxicity at the genetic level provides valuable information, which is of importance in the safety assessment of the fungicide.

scholarly journals Phytohemagglutinin-stimulated normal human peripheral blood lymphocytes in folate-depleted medium: an in vitro model for megaloblastic hemopoiesis

Blood ◽  
1980 ◽  
Vol 55 (5) ◽  
pp. 863-865
Author(s):  
RJ Hayman ◽  
MB Van Der Weyden
Keyword(s):  
Peripheral Blood ◽  
Thymidine Incorporation ◽  
Human Peripheral Blood ◽  
Inhibitory Effect ◽  
Peripheral Blood Lymphocytes ◽  
Blood Lymphocytes ◽  
Human Peripheral Blood Lymphocytes ◽  
Normal Human ◽  
Normal Human Peripheral Blood

Normal human peripheral blood lymphocytes cultured with phytohemagglutinin in folate-free RPMI 1640 medium supplemented with normal human serum exhibit megaloblastic maturation. These changes are accompanied by a decrease in intracellular folate content, and when compared to folate-replete cells, reveal increased 3H-thymidine incorporation into DNA together with a decreased inhibitory effect of deoxyuridine on 3H-thymidine incorporation. This in vitro system of cellular folate deficiency is a convenient model for analysis of biochemical events accompanying megaloblastic maturation.

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