scholarly journals The intracellular transport of low density lipoprotein-derived cholesterol is defective in Niemann-Pick type C fibroblasts.

1989 ◽  
Vol 108 (5) ◽  
pp. 1625-1636 ◽  
Author(s):  
L Liscum ◽  
R M Ruggiero ◽  
J R Faust
Keyword(s):  
Plasma Membrane ◽  
Intracellular Transport ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cholesterol Transport ◽  
Low Density ◽  
Unesterified Cholesterol ◽  
Type C ◽  
Niemann Pick

Niemann-Pick disease type C (NPC) is characterized by substantial intracellular accumulation of unesterified cholesterol. The accumulation of unesterified cholesterol in NPC fibroblasts cultured with low density lipoprotein (LDL) appears to result from the inability of LDL to stimulate cholesterol esterification in addition to impaired LDL-mediated downregulation of LDL receptor activity and cellular cholesterol synthesis. Although a defect in cholesterol transport in NPC cells has been inferred from previous studies, no experiments have been reported that measure the intracellular movement of LDL-cholesterol specifically. We have used four approaches to assess intracellular cholesterol transport in normal and NPC cells and have determined the following: (a) mevinolin-inhibited NPC cells are defective in using LDL-cholesterol for growth. However, exogenously added mevalonate restores cell growth equally in normal and NPC cells; (b) the transport of LDL-derived [3H]cholesterol to the plasma membrane is slower in NPC cells, while the rate of appearance of [3H]acetate-derived, endogenously synthesized [3H]cholesterol at the plasma membrane is the same for normal and NPC cells; (c) in NPC cells, LDL-derived [3H]cholesterol accumulates in lysosomes to higher levels than normal, resulting in defective movement to other cell membranes; and (d) incubation of cells with LDL causes an increase in cholesterol content of NPC lysosomes that is threefold greater than that observed in normal lysosomes. Our results indicate that a cholesterol transport defect exists in NPC that is specific for LDL-derived cholesterol.

scholarly journals Type C Niemann-Pick disease. Abnormal metabolism of low density lipoprotein in homozygous and heterozygous fibroblasts.

1986 ◽  
Vol 261 (35) ◽  
pp. 16769-16774 ◽  
Author(s):  
H S Kruth ◽  
M E Comly ◽  
J D Butler ◽  
M T Vanier ◽  
J K Fink ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Niemann Pick Disease ◽  
Abnormal Metabolism ◽  
Type C ◽  
Niemann Pick ◽  
Pick Disease

scholarly journals Last step in the path of LDL cholesterol from lysosome to plasma membrane to ER is governed by phosphatidylserine

2020 ◽  
Vol 117 (31) ◽  
pp. 18521-18529 ◽  
Author(s):  
Michael N. Trinh ◽  
Michael S. Brown ◽  
Joseph L. Goldstein ◽  
Jaeil Han ◽  
Gonçalo Vale ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Feedback Loop ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cholesterol Transport ◽  
Animal Cells ◽  
Cholesterol Accumulation ◽  
Gene Encoding ◽  
Ldl Receptors

Animal cells acquire cholesterol from receptor-mediated uptake of low-density lipoprotein (LDL), which releases cholesterol in lysosomes. The cholesterol moves to the endoplasmic reticulum (ER), where it inhibits production of LDL receptors, completing a feedback loop. Here we performed a CRISPR-Cas9 screen in human SV589 cells for genes required for LDL-derived cholesterol to reach the ER. We identified the gene encoding PTDSS1, an enzyme that synthesizes phosphatidylserine (PS), a phospholipid constituent of the inner layer of the plasma membrane (PM). In PTDSS1-deficient cells where PS is low, LDL cholesterol leaves lysosomes but fails to reach the ER, instead accumulating in the PM. The addition of PS restores cholesterol transport to the ER. We conclude that LDL cholesterol normally moves from lysosomes to the PM. When the PM cholesterol exceeds a threshold, excess cholesterol moves to the ER in a process requiring PS. In the ER, excess cholesterol acts to reduce cholesterol uptake, preventing toxic cholesterol accumulation. These studies reveal that one lipid—PS—controls the movement of another lipid—cholesterol—between cell membranes. We relate these findings to recent evidence indicating that PM-to-ER cholesterol transport is mediated by GRAMD1/Aster proteins that bind PS and cholesterol.

Platelet Aggregation and Plasma Lipoproteins in Alcoholics During Alcohol Withdrawal

1986 ◽  
Vol 55 (02) ◽  
pp. 173-177 ◽  
Author(s):  
K Desai ◽  
J S Owen ◽  
D T Wilson ◽  
R A Hutton
Keyword(s):  
Platelet Aggregation ◽  
Alcohol Withdrawal ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Plasma Lipoprotein ◽  
Cholesterol Concentration ◽  
Arachidonic Acid Content ◽  
Low Density

SummaryPlatelet aggregation, platelet lipid composition and plasma lipoprotein concentrations were measured each week in a group of seventeen alcoholics, without overt liver disease, for one month, following acute, total alcohol withdrawal. The platelets were initially hypoaggregable but, within 1-2 weeks of cessation of drinking, they became hyperaggregable and then gradually returned towards normal values. Hyperaggregability could not be explained by increases in either the cholesterol or the arachidonic acid content of the platelets. Plasma very-low-density lipoprotein cholesterol levels remained high throughout the study, but the initially raised levels of high-density lipoprotein (HDL) cholesterol fell by 26%. Low-density lipoprotein (LDL) cholesterol concentration rose by 10% after two weeks of withdrawal but then returned to about the starting level. The resulting changes in the plasma LDL-cholesterol: HDL-cholesterol ratio, which had increased by more than 50% after two weeks of abstinence, essentially paralleled the time course of enhanced platelet reactivity in all but four of the alcoholics. These findings suggest that alterations in plasma lipoprotein concentrations during acute alcohol withdrawal may be a contributory factor to the haemostatic disorders present in such patients.

scholarly journals Effects of Weight Gain after 20 Years of Age and Incidence of Hyper-Low-Density Lipoprotein Cholesterolemia: The Iki Epidemiological Study of Atherosclerosis and Chronic Kidney Disease (ISSA-CKD)

2021 ◽  
Vol 10 (14) ◽  
pp. 3098
Author(s):  
Shota Okutsu ◽  
Yoshifumi Kato ◽  
Shunsuke Funakoshi ◽  
Toshiki Maeda ◽  
Chikara Yoshimura ◽  
...  
Keyword(s):  
Weight Gain ◽  
General Population ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Population Based ◽  
Lipid Lowering ◽  
Low Density ◽  
Obesity Hypertension ◽  
Old Men

The aim of this study was to investigate the effects of long-term weight gain from the age of 20 on incidence of hyper-low-density-lipoprotein (LDL) cholesterolemia in the general population of Japanese people. Methods: We conducted a population-based retrospective cohort study using annual health checkup data for residents of Iki City, Nagasaki Prefecture, Japan. A total of 3179 adult (≥30 years old) men and women without hyper-LDL cholesterolemia at baseline, who underwent two or more health checkups were included in the analysis. Information on weight gain (≥10 kg) after 20 years of age was obtained using questionnaire. The outcome of this study was development of hyper-LDL cholesterolemia defined as LDL-cholesterol level ≥3.62 mmol/L and/or initiation of lipid-lowering medications. Results: During a mean follow-up period of 4.53 years, 665 of the 3179 participants developed hyper-LDL cholesterolemia (46.5/1000 person-years). The incidence of hyper-LDL cholesterolemia was higher in participants with a weight gain of ≥10 kg (55.3/1000 person-years) than among those with a weight gain of <10 kg (41.8/1000 person-years). This association remained statistically significant even after adjustment for age, sex, smoking, daily drinking, exercise, obesity, hypertension, and diabetes (multivariable hazard ratio 1.31, 95% confidence interval 1.08–1.58, p = 0.006). Conclusion: A weight gain of ≥10 after 20 years of age affected the development of hyper-LDL cholesterol regardless of age, sex, and obesity in a general population of Japanese.

Effect of the periparturient period on serum lipid and cholesterol lipoprotein concentrations in goats (Capra hircus)

2011 ◽  
Vol 59 (4) ◽  
pp. 445-454 ◽  
Author(s):  
Ewa Skotnicka ◽  
Zbigniew Muszczyński ◽  
Maria Suska
Keyword(s):  
Serum Lipid ◽  
Ldl Cholesterol ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Capra Hircus ◽  
Low Density ◽  
Total Lipids ◽  
Blood Samples ◽  
Periparturient Period

Blood samples were taken from 12 goats during the periparturient period (4 and 1 weeks before and 2, 10 and 30 days after delivery), and from 10 nonpregnant goats. The following variables were determined: total lipids (TL), triacylglycerol (TG), total cholesterol (TCH) and high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol fractions. One week before delivery TL (2.32 ± 0.12 g/l, P ≤ 0.05), TG (0.32 ± 0.16 mmol/l, P ≤ 0.001) and TCH concentrations (1.65 ± 0.42 mmol/l, P ≤ 0.05) were significantly increased as compared to non-pregnant goats (2.08 ± 0.28 g/l, 0.15 ± 0.05 mmol/l, 1.38 ± 0.19 mmol/l, respectively). After delivery, the concentrations of TL, TG, TCH and HDL decreased significantly. The lowest TG concentration was observed 2 days after delivery (0.18 ± 0.02 mmol/l), while TL (1.73 ± 0.21 g/l), TCH (0.95 ± 0.21 mmol/l) and HDL (0.74 ± 0.16 mmol/l) reached the lowest level 10 days after delivery. Two days after delivery a significant increase of LDL concentration was observed (0.38 ± 0.04 mmol/l); however, ten days after delivery a threefold decrease was shown in the LDL concentration (0.12 ± 0.04 mmol/l). A month after delivery all the variables studied reached levels similar to those measured in non-pregnant goats.

Sign in / Sign up

Export Citation Format

Share Document