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 ◽  
...  

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.

2005 ◽  
Vol 289 (6) ◽  
pp. G1067-G1074 ◽  
Author(s):  
Michele K. Wu ◽  
David E. Cohen

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.


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

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.


2004 ◽  
Vol 377 (3) ◽  
pp. 545-552 ◽  
Author(s):  
Shubha MURTHY ◽  
Ella BORN ◽  
Satya N. MATHUR ◽  
F. Jeffrey FIELD

The effect of fatty acids on LXR (liver X receptors)-mediated enhancement of ABCA1 (ATP-binding cassette transporter A1) expression and cholesterol efflux was investigated in human intestinal cells CaCo-2. LXR activation by T0901317 increased basolateral cholesterol efflux to lipoprotein particles isolated at a density of 1.21 g/ml or higher. Oleic and arachidonic acids attenuated the amount of cholesterol isolated from these particles. Stearic, linoleic and docosahexaenoic acids also decreased cholesterol efflux from basolateral membranes, with the polyunsaturated fatty acids being the most potent. Although oleic, arachidonic and docosahexaenoic acids modestly decreased ABCA1 mRNA levels in response to LXR activation, stearic and linoleic acids did not. Except for oleic acid, all fatty acids substantially attenuated an increase in ABCA1 mass secondary to LXR activation. Inhibiting acyl-CoA:cholesterol acyltransferase activity prevented the decrease in cholesterol efflux caused by oleic acid. Thus, in response to LXR activation, all fatty acids decreased the efflux of cholesterol from the basolateral membrane of CaCo-2 cells. Although modest suppression of ABCA1 gene expression by oleic, arachidonic and docosahexaenoic acids cannot be completely excluded as a mechanism, the predominant effect of fatty acids on ABCA1 expression and cholesterol efflux is at a post-transcriptional level.


2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Manya Warrier ◽  
Stepahie Marshall ◽  
Allison McDaniel ◽  
Martha Wilson ◽  
Amanda Brown ◽  
...  

Recent studies have revealed a novel route for cholesterol disposal through intestine known as transintestinal cholesterol efflux (TICE) that significantly contributes to fecal neutral sterol loss. This pathway is an integral part of reverse cholesterol transport (RCT), yet major mechanisms regulating TICE are not well understood. Using an unbiased transcriptional profiling approach in mouse models of augmented TICE, we found that hepatic expression of the enzyme Flavin monoxygenase 3 (FMO3) was dramatically repressed. At the same time we identified this enzyme through transcriptional profiling, it was reported that plasma levels of its product trimethylamineoxide (TMAO) are highly predictive of atheroslcerosis in humans, and TMAO is proatherogenic in mice. To further understand FMO3’s role as a regulator of cholesterol metabolism we used antisense oligonucleotides (ASO) to knockdown FMO3 expression in mouse liver in C57BL/6 mice fed either low (0.02%) or high (0.2%) levels of dietary cholesterol. As expected, FMO3 knockdown (>90% knockdown in the liver) increased the TMA/TMAO ratio in plasma more than 3-fold. Interestingly, knockdown of FMO biliary cholesterol levels were reduced by 60%, whereas fecal cholesterol loss was quite normal in FMO3 ASO treated mice fed a high cholesterol diet, which phenocopies a previously described mouse model where TICE predominates (NPC1L1-liver transgenic mice). ASO-mediated knockdown of FMO3 also unexpectedly reduced hepatic cholesteryl ester (CE) storage by 70% in mice fed 0.2% cholesterol. In parallel, knockdown of FMO3 reduces plasma VLDL cholesterol levels and the secretion rate of VLDL cholesteryl ester, but not triacylglycerol in cholesterol fed mice. FMO3 knockdown also reduced the hepatic expression of several liver X receptor (LXR) target genes, while increasing expression of genes involved in cholesterol synthesis. Collectively, these studies have identified FMO3 as a novel regulator of hepatic cholesterol metabolism and TICE. Given that plasma levels of FMO3’s product (TMAO) are strongly associated with atherosclerosis development in humans, and production of TMAO promotes atherosclerosis in mice, these studies have important implications for future cardiovascular drug discovery.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Erdi Sozen ◽  
Burak Yazgan ◽  
Ali Sahin ◽  
Umit Ince ◽  
Nesrin Kartal Ozer

Involvement of high cholesterol and oxidative stress in cardiovascular diseases is well studied, as it can be hypothesized that various products originated from lipid peroxidation, such as oxysterols, or affected protein expression might lead to cardiomyocyte damage followed by the pathological modifications. Although oxidation of excessive cholesterol to oxysterols in elevated stress conditions is identified by a number of studies, the role of a high cholesterol diet in regulating fatty acid and oxysterol accumulation, together with scavenger receptor mRNA levels, in the heart remains little investigated. Our study provides a detailed analysis of the changes in fatty acid, oxysterol, and scavenger receptor profiles and its relation with histological alterations in the heart tissue. We evaluated alterations of fatty acid composition, by the GC-MS method, while 4β-, 25-, and 27-hydroxycholesterol and 7-ketocholesterol levels by means of LC-MS/MS in high cholesterol diet-fed rabbits. Additionally, a number of proteins related to lipid metabolism and scavenger receptor mRNA expressions were evaluated by Western blotting and RT-PCR. According to our in vivo results, a high cholesterol diet enhances a number of unsaturated fatty acids, oxysterols, and LXRα, in addition to CD36, CD68, CD204, and SR-F1 expressions while α-tocopherol supplementation decreases LXRα and SR expressions together with an increase in 27-hydroxycholesterol and ABCA1 levels. Our results indicated that the high cholesterol diet modulates proteins related to lipid metabolism, which might result in the malfunction of the heart and α-tocopherol shows its beneficial effects. We believe that this work will lead the generation of different theories in the development of heart diseases.


2012 ◽  
Vol 26 (S1) ◽  
Author(s):  
SALIM S. AL-REJAIE ◽  
Hatem M. Abuohashish ◽  
Abdulaziz S. Alroujayee ◽  
Abdulaziz M. Aleisa ◽  
Osama Alkhamees

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