scholarly journals Phosphatidylcholine transfer protein regulates size and hepatic uptake of high-density lipoproteins

2005 ◽  
Vol 289 (6) ◽  
pp. G1067-G1074 ◽  
Author(s):  
Michele K. Wu ◽  
David E. Cohen
Keyword(s):  
Plasma Cholesterol ◽  
High Cholesterol Diet ◽  
Atp Binding ◽  
Cholesterol Diet ◽  
Wild Type ◽  
High Cholesterol ◽  
High Fat ◽  
Transfer Protein ◽  
Phosphatidylcholine Transfer Protein ◽  
Atp Binding Cassette

Phosphatidylcholine transfer protein (PC-TP) is a steroidogenic acute regulatory-related transfer domain protein that is enriched in liver cytosol and binds phosphatidylcholines with high specificity. In tissue culture systems, PC-TP promotes ATP-binding cassette protein A1-mediated efflux of cholesterol and phosphatidylcholine molecules as nascent pre-β-high-density lipoprotein (HDL) particles. Here, we explored a role for PC-TP in HDL metabolism in vivo utilizing 8-wk-old male Pctp−/− and wild-type littermate C57BL/6J mice that were fed for 7 days with either chow or a high-fat/high-cholesterol diet. In chow-fed mice, neither plasma cholesterol concentrations nor the concentrations and compositions of plasma phospholipids were influenced by PC-TP expression. However, in Pctp−/− mice, there was an accumulation of small α-migrating HDL particles. This occurred without changes in hepatic expression of ATP-binding cassette protein A1 or in proteins that regulate the intravascular metabolism and clearance of HDL particles. In Pctp−/− mice fed the high-fat/high-cholesterol diet, HDL particle sizes were normalized, whereas plasma cholesterol and phospholipid concentrations were increased compared with wild-type mice. In the absence of upregulation of hepatic ATP-binding cassette protein A1, reduced HDL uptake from plasma into livers of Pctp−/− mice contributed to higher plasma lipid concentrations. These data indicate that PC-TP is not essential for the enrichment of HDL with phosphatidylcholines but that it does modulate particle size and rates of hepatic clearance.

scholarly journals The Effects of High Hydrostatic Pressure Extract of Mulberry Fruit on Hepatic Cholesterol Metabolism in Rats (P06-013-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Jaerin Lee ◽  
Soojin Lee ◽  
Mak-Soon Lee ◽  
Yoonjin Lee ◽  
Jiyeon Kim ◽  
...  
Keyword(s):  
Cholesterol Efflux ◽  
Cholesterol Metabolism ◽  
High Cholesterol Diet ◽  
Atp Binding ◽  
Mrna Levels ◽  
Cholesterol Diet ◽  
Hepatic Cholesterol ◽  
High Cholesterol ◽  
Mulberry Fruit ◽  
Atp Binding Cassette

Abstract Objectives The objective of this study is to investigate the effects of high hydrostatic pressure (HHP) extract of mulberry fruit on the regulation of hepatic cholesterol metabolism in high-cholesterol diet fed rats. Methods Male Sprague-Dawley rats(6-week-old) were randomly divided into 5 groups, and fed with a normal diet (NOR), High cholesterol diet (HC), HC supplemented with 0.4% mulberry (ML) or 0.8% mulberry (MH) and HC treated with statin (ST) for 4 weeks. Results The HHP extract of mulberry fruit did not affect body weight gain and food intake and reduced the serum and liver lipids in the mulberry supplemented groups (ML, MH). In this study, we found that the HHP extract of mulberry fruit changed the level of genes involved in hepatic cholesterol metabolism. In the MH group, the mRNA levels of apolipoprotein A-1 (apoA-1), ATP-binding cassette transporter A1 (ABCA1) and lecithin-cholesterol acyltransferase (LCAT), which are involved in hepatic HDL biogenesis, were significantly increased by 1.80-, 1.77- and 2.65-fold, respectively, compared with the HC group. The MH group also significantly upregulated mRNA levels of cholesterol efflux related gene such as the liver X receptor α (LXRα), ATP-binding cassette protein G5 (ABCG5) and ATP-binding cassette protein G8 (ABCG8) compared to the HC group in the liver tissue. ABCG5 and ABCG8 expression levels of the MH group were also higher than those of the ST group. The mRNA level of cholesterol 7a-hydroxylase (CYP7A1), which is bile acid synthetic rate-limiting enzyme was higher in the MH group than that of the HC group. Furthermore, the immunohistochemical staining intensity became evident for CYP7A1 in liver of the MH group. Conclusions These results suggest at least partial involvement of HDL cholesterol synthesis, cholesterol efflux and bile acid synthesis in HHP extract of mulberry fruit mediated beneficial effects on hepatic cholesterol metabolism. Funding Sources None.

scholarly journals The Aromatase Knockout Mouse Presents with a Sexually Dimorphic Disruption to Cholesterol Homeostasis

Endocrinology ◽  
2003 ◽  
Vol 144 (9) ◽  
pp. 3895-3903 ◽  
Author(s):  
Kylie N. Hewitt ◽  
Wah Chin Boon ◽  
Yoko Murata ◽  
Margaret E. E. Jones ◽  
Evan R. Simpson
Keyword(s):  
Elevated Serum ◽  
Dietary Cholesterol ◽  
Cholesterol Homeostasis ◽  
High Cholesterol Diet ◽  
Atp Binding ◽  
Sexually Dimorphic ◽  
Hepatic Cholesterol ◽  
Wild Type ◽  
High Cholesterol ◽  
Atp Binding Cassette

Abstract The aromatase knockout (ArKO) mouse cannot synthesize endogenous estrogens due to disruption of the Cyp19 gene. We have shown previously, that ArKO mice present with age-progressive obesity and hepatic steatosis, and by 1 yr of age both male and female ArKO mice develop hypercholesterolemia. In this present study 10- to 12-wk-old ArKO mice were challenged for 90 d with high cholesterol diets. Our results show a sexually dimorphic response to estrogen deficiency in terms of cholesterol homeostasis in the liver. ArKO females presented with elevated serum cholesterol; conversely, ArKO males had elevated hepatic cholesterol levels. In response to dietary cholesterol, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase transcript levels were significantly reduced in females, whereas males showed more modest changes. Neither low density lipoprotein nor sterol regulatory element-binding protein expression levels were significantly altered by diet or genotype. The expression of Cyp7a, which encodes cholesterol 7α-hydroxylase, was significantly reduced in ArKO females compared with wild-type females and was increased by cholesterol feeding. Cyp7a expression was significantly elevated in the wild-type males on the high cholesterol diet, although no difference was seen between genotypes on the control diet. The ATP-binding cassette G5 and ATP-binding cassette G8 transporters do not appear to be regulated by estrogen. The expression of acyl-coenzyme A:cholesterol acyltransferase 2 showed a sexually dimorphic response, where estrogen appeared to have a stimulatory effect in females, but not males. This study reveals a sexually dimorphic difference in mouse hepatic cholesterol homeostasis and roles for estrogen in the regulation of cholesterol uptake, biosynthesis, and catabolism in the female, but not in the male.

scholarly journals High Cholesterol Diet Exacerbates Blood-Brain Barrier Disruption in LDLr–/– Mice: Impact on Cognitive Function

2020 ◽  
Vol 78 (1) ◽  
pp. 97-115
Author(s):  
Jade de Oliveira ◽  
Daiane F. Engel ◽  
Gabriela C. de Paula ◽  
Danúbia B. dos Santos ◽  
Jadna B. Lopes ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Familial Hypercholesterolemia ◽  
Blood Brain Barrier ◽  
Plasma Cholesterol ◽  
High Cholesterol Diet ◽  
Cholesterol Diet ◽  
Wild Type ◽  
High Cholesterol ◽  
Cholesterol Levels ◽  
Hypercholesterolemic Diet

Background: Evidence has revealed an association between familial hypercholesterolemia and cognitive impairment. In this regard, a connection between cognitive deficits and hippocampal blood-brain barrier (BBB) breakdown was found in low-density lipoprotein receptor knockout mice (LDLr–/–), a mouse model of familial hypercholesterolemia. Objective: Herein we investigated the impact of a hypercholesterolemic diet on cognition and BBB function in C57BL/6 wild-type and LDLr–/–mice. Methods: Animals were fed with normal or high cholesterol diets for 30 days. Thus, wild-type and LDLr–/–mice were submitted to memory paradigms. Additionally, BBB integrity was evaluated in the mice’s prefrontal cortices and hippocampi. Results: A tenfold elevation in plasma cholesterol levels of LDLr–/–mice was observed after a hypercholesterolemic diet, while in wild-type mice, the hypercholesterolemic diet exposure increased plasma cholesterol levels only moderately and did not induce cognitive impairment. LDLr–/–mice presented memory impairment regardless of the diet. We observed BBB disruption as an increased permeability to sodium fluorescein in the prefrontal cortices and hippocampi and a decrease on hippocampal claudin-5 and occludin mRNA levels in both wild-type and LDLr–/–mice treated with a hypercholesterolemic diet. The LDLr–/–mice fed with a regular diet already presented BBB dysfunction. The BBB-increased leakage in the hippocampi of LDLr–/–mice was related to high microvessel content and intense astrogliosis, which did not occur in the control mice. Conclusion: Therefore, LDLr–/–mice seem to be more susceptible to cognitive impairments and BBB damage induced by exposure to a high cholesterol diet. Finally, BBB disruption appears to be a relevant event in hypercholesterolemia-induced brain alterations.

Sub-chronic microcystin-LR renal toxicity in rats fed a high fat/high cholesterol diet

Chemosphere ◽  
2020 ◽  
pp. 128773
Author(s):  
Tarana Arman ◽  
Katherine D. Lynch ◽  
Michael Goedken ◽  
John D. Clarke
Keyword(s):  
Renal Toxicity ◽  
High Cholesterol Diet ◽  
Cholesterol Diet ◽  
High Cholesterol ◽  
High Fat

scholarly journals Interleukin-18 predicts atherosclerosis progression in SIV-infected and uninfected rhesus monkeys (Macaca mulatta) on a high-fat/high-cholesterol diet

2009 ◽  
Vol 89 (6) ◽  
pp. 657-667 ◽  
Author(s):  
Jennifer H Yearley ◽  
Dongling Xia ◽  
Christine B Pearson ◽  
Angela Carville ◽  
Richard P Shannon ◽  
...  
Keyword(s):  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
High Cholesterol Diet ◽  
Cholesterol Diet ◽  
Interleukin 18 ◽  
High Cholesterol ◽  
High Fat ◽  
Atherosclerosis Progression

Abstract 130: Hypercholesterolemia Suppresses Carotid Artery Endothelial NOS3 Expression via Epigenetic Mechanisms

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Alex Sotolongo ◽  
Yi-Zhou Jiang ◽  
John Karanian ◽  
William Pritchard ◽  
Peter Davies
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Endothelial Cells ◽  
Dna Methyltransferase ◽  
Control Group ◽  
High Cholesterol Diet ◽  
Cholesterol Diet ◽  
High Cholesterol ◽  
High Fat

Objective: One of the first clinically detectable changes in the vasculature during atherogenesis is the accumulation of cholesterol within the vessel wall. Hypercholesterolemia is characterized by dysfunctional endothelial-dependent vessel relaxation and impaired NOS3 function. Since DNA methylation at gene promoter regions strongly suppresses gene expression, we postulated that high-fat/high-cholesterol diet suppresses endothelial NOS3 through promoter DNA methylation. Methods: Domestic male pigs were fed control diet (CD) or isocaloric high fat and high cholesterol diet (HC; 12% fat and 1.5% cholesterol) for 2, 4, 8 or 12 weeks prior to tissue collection. Furthermore, to determine the effects of risk factor withdrawal, an additional group of swine received HC for 12 weeks and then CD for 8 weeks; a control group received HC continuously for 20 weeks. Endothelial cells were harvested from common carotid aorta. In parallel in vitro studies, cultured human aortic endothelial cells (HAEC) were treated with human LDL, GW3956 (LXR agonist) and RG108 (DNA methyltransferase [DNMT] inhibitor). In cells from both sources, DNA methylation at the NOS3 promoter was measured using methylation specific pyro sequencing, and endothelial gene expression was measured using RT PCR. Results: HC diet increased plasma cholesterol level from 75 mg/dl on CD to a plateau of about 540 mg/dl within 2 weeks. Endothelial NOS3 expression was significantly reduced (71±9 % of CD) after 4 weeks of HC, a level sustained at subsequent time points. Withdrawal of HC for 8 weeks did not recover NOS3 expression. After 12-week HC, the NOS3 promoter was hypermethylated. Withdrawal of HC did not reverse NOS3 promoter methylation. In vitro treatment of HAEC with human LDL (200 mg/dl total cholesterol) or GW3956 (5μM) suppressed NOS3 mRNA to 50% and 30% respectively, suggesting that LXR/RXR is involved in suppression of NOS3. Nitric oxide production was consistently suppressed by GW3959. Both could be reversed through inhibition of DNMTs by RG108. Conclusions: DNA methylation and LXR/RXR pathway can mediate the HC-suppression of endothelial NOS3. The study identifies novel pharmaceutical targets in treating endothelial dysfunction. Crosstalk between these pathways is under investigation.

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