scholarly journals Impact of Soy β-Conglycinin Peptides on PCSK9 Protein Expression in HepG2 Cells

Nutrients ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 193
Author(s):  
Chiara Macchi ◽  
Maria Francesca Greco ◽  
Nicola Ferri ◽  
Paolo Magni ◽  
Anna Arnoldi ◽  
...  

Background: Dyslipidaemias, particularly elevated plasma low-density lipoprotein cholesterol (LDL-C) levels, are major risk factors for cardiovascular disease (CVD). Besides pharmacological approaches, a nutritional strategy for CVD prevention has gained increasing attention. Among functional foods, the hypocholesterolemic properties of soy are driven by a stimulation of LDL-receptor (LDL-R) activity. Aim: To characterize the effect of two soy peptides, namely, β-conglycinin-derived YVVNPDNDEN and YVVNPDNNEN on the expression of proprotein convertase subtilisin/kexin type 9 (PCSK9), one of the key-regulators of the LDL-R. Methods: PCSK9 promoter activity (luciferase assay), PCSK9 protein expression (WB) and secretion (ELISA), PCSK9 interaction with LDL-R (binding assay) and human HepG2 cells were the objects of this investigation. Results: Treatment with YVVNPDNNEN peptide has led to a rise in PCSK9 gene expression (90.8%) and transcriptional activity (86.4%), and to a decrement in PCSK9 intracellular and secreted protein (−42.9%) levels. YVVNPDNNEN peptide reduced the protein expression of transcriptional factor HNF1α. Most changes driven by YVVNPDNDEN peptide were not statistically significant. Neither peptide inhibited the PCSK9–LDLR interaction. Conclusions: Although sharing a common effect on LDL-R levels through the inhibition of 3-hydroxy-3-methylglutaryl CoA reductase activity, only the YVVNPDNNEN peptide has an additional mechanism via the downregulation of PCSK9 protein levels.

Nutrients ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1665 ◽  
Author(s):  
Carmen Lammi ◽  
Carlotta Bollati ◽  
Davide Lecca ◽  
Maria Pia Abbracchio ◽  
Anna Arnoldi

GQEQSHQDEGVIVR (T9) is a peptide originated by the tryptic digestion of lupin β-conglutin that is absorbed in human intestinal Caco-2 cells. A previous study has shown that T9 impairs the protein–protein interaction between mutant D374Y Proprotein Convertase Subtilisin/Kexin 9 (PCSK9D374Y) and the low-density lipoprotein receptor (LDLR), thus exerting a hypocholesterolemic effect. Moreover, a bioinformatic study predicting that T9 may potentially act as an inhibitor of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCoAR), has suggested a complementary cholesterol-lowering activity. The present study demonstrates that T9 inhibits in vitro the HMGCoAR functionality with an IC50 value of 99.5 ± 0.56 µM. Through the inhibition of either HMGCoAR or PCSK9D374Y activities, T9 enhances the LDLR protein levels leading to an improved ability of HepG2 cells transfected with the mutant PCSK9D374Y-FLAG plasmid to uptake extracellular LDL with a final cholesterol-lowering effect. In addition, T9 modulates the PCSK9D374Y signaling pathway in transfected HepG2 cells leading to a decrease of PCSK9D374Y and HNF-1α protein levels. All these results indicate that the hypocholesterolemic effects of T9 are due to a dual mechanism of action involving either the modulation of the PCSK9D374Y or LDLR pathways. This may represent an added value from a therapeutic point of view.


1989 ◽  
Vol 260 (3) ◽  
pp. 731-736 ◽  
Author(s):  
D T Molowa ◽  
G M Cimis

Cellular processes responsible for maintaining cholesterol homoeostasis are highly regulated. To determine whether two of these processes, cholesterol biosynthesis and receptor-mediated uptake of low-density lipoprotein (LDL), are co-ordinately regulated in human liver, we employed a human hepatoma cell line (HepG2) and measured the accumulation of mRNA for LDL receptor, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase and HMG-CoA synthase under a variety of conditions. Genomic Southern-blot analysis demonstrated that the integrity of these genes is maintained in the transformed cell. Treatment of HepG2 cells with mevalonate, 25-hydroxycholesterol, LDL, lovastatin or miconazole resulted in a similar effect on the accumulation of all three mRNAs at the concentrations tested. The onset of the response to drug, whether repression or induction of mRNA accumulation, occurred after approximately the same period of exposure for each mRNA. We conclude that the expression of the LDL receptor, HMG-CoA reductase and HMG-CoA synthase is co-ordinately regulated in HepG2 cells.


2019 ◽  
Vol 15 (3) ◽  
pp. 213-223 ◽  
Author(s):  
Rabia Nabi ◽  
Sahir Sultan Alvi ◽  
Mohd. Saeed ◽  
Saheem Ahmad ◽  
Mohammad Salman Khan

Introduction: Diabetes Mellitus (DM) acts as an absolute mediator of cardiovascular risk, prompting the prolonged occurrence, size and intricacy of atherosclerotic plaques via enhanced Advanced Glycation Endproducts (AGEs) formation. Moreover, hyperglycemia is associated with enhanced glyco-oxidized and oxidized Low-Density Lipoprotein (LDL) possessing greater atherogenicity and decreased the ability to regulate HMG-CoA reductase (HMG-R). Although aminoguanidine (AG) prevents the AGE-induced protein cross-linking due to its anti-glycation potential, it exerts several unusual pharmaco-toxicological effects thus restraining its desirable therapeutic effects. HMG-R inhibitors/statins exhibit a variety of beneficial impacts in addition to the cholesterol-lowering effects. Objective: Inhibition of AGEs interaction with receptor for AGEs (RAGE) and glyco-oxidized-LDL by HMG-R inhibitors could decrease LDL uptake by LDL-receptor (LDL-R), regulate cholesterol synthesis via HMG-R, decrease oxidative and inflammatory stress to improve the diabetes-associated complications. Conclusion: Current article appraises the pathological AGE-RAGE concerns in diabetes and its associated complications, mainly focusing on the phenomenon of both circulatory AGEs and those accumulating in tissues in diabetic nephropathy, diabetic neuropathy, and diabetic retinopathy, discussing the potential protective role of HMG-R inhibitors against diabetic complications.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Hiroe Go ◽  
Jin Ah Ryuk ◽  
Hye Won Lee ◽  
In Sil Park ◽  
Ki-Jung Kil ◽  
...  

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.


1990 ◽  
Vol 272 (1) ◽  
pp. 181-186 ◽  
Author(s):  
T A Berkhout ◽  
L M Havekes ◽  
N J Pearce ◽  
P H E Groot

(-)-Hydroxycitrate, a potent inhibitor of ATP citrate-lyase, was tested in Hep G2 cells for effects on cholesterol homoeostasis. After 2.5 h and 18 h incubations with (-)-hydroxycitrate at concentrations of 0.5 mM or higher, incorporation of [1,5-14C]citrate into fatty acids and cholesterol was strongly inhibited. This most likely reflects an effective inhibition of ATP citrate-lyase. Cholesterol biosynthesis was decreased to 27% of the control value as measured by incorporations from 3H2O, indicating a decreased flux of carbon units through the cholesterol-synthetic pathway. After 18 h preincubation with 2 mM-(-)-hydroxycitrate, the cellular low-density-lipoprotein (LDL) receptor activity was increased by 50%, as determined by the receptor-mediated association and degradation. Measurements of receptor-mediated binding versus LDL concentration suggests that this increase was due to an increase in the numbers of LDL receptors. Simultaneously, enzyme levels of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase as determined by activity measurements increased 30-fold. Our results suggest that the increases in HMG-CoA reductase and the LDL receptor are initiated by the decreased flux of carbon units in the cholesterol-synthetic pathway, owing to inhibition of ATP citratelyase. A similar induction of HMG-CoA reductase and LDL receptor was also found after preincubations of cells with 0.3 microM-mevinolin, suggesting that the underlying mechanism for this induction is identical for both drugs.


Author(s):  
Mumtaz Khan Mohammad ◽  
Monika Padmanabhan

Objective: Diet-inducedhyperlipidemia and obesity are the major risk factors for type II diabetes mellitus, hypertension, musculoskeletal and cardiovascular disorders (CVD). The objective of the present study is to furnish scientific proof for the lipid-lowering effect of β-glucan, a lead compound present in barley with a defined mechanism of action. Methods: Obesity was induced in male albino Wistar rats by feeding ahigh-fat diet (HFD) for 14 w and were randomly divided into four groups of equal number (n=6). Group 1 and 2 served as control fed with normal diet (5% fat). Group 3 and 4 were fed HFD (23%fat) for 14 w. In addition, group 2 and 4 rats were administered orally with 200 mg/kg body weight of barley β glucan (BRBG) from the third week. After 14 w, the rats were sacrificed, and serum/plasma levels of total cholesterol (TC), phospholipids, triglycerides (TG), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and adiponectin were determined. Results: Biochemical changes were observed in weight gain, body mass index (BMI),adiposity index (ADI), total fat pad mass (TFP), blood lipids, LDL, lipid peroxides (LPO) and antioxidant enzyme activity of HFD fed rats when compared with BRBG co-administered rats. In addition, serum adiponectin levels and 3-hydroxy-3methyl-glutaryl-coenzyme Areductase(HMG CoA reductase)activity were elevated in rats administered BRBG along with HFD. Histological examination in HFD induced rats revealed a profound change in cell size with increased hypertrophy in visceral adipose tissue. Conclusions: The results indicate that barley consumption could reverse most of these biochemical and histological changes in HFD fed rats owing to its hypolipidemic and antioxidant effect.


1998 ◽  
Vol 329 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Lahoucine IZEM ◽  
Eric RASSART ◽  
Lassana KAMATE ◽  
Louise FALSTRAULT ◽  
David RHAINDS ◽  
...  

Low-density lipoproteins (LDL) are taken up by both LDL receptor (LDLr)-dependent and -independent pathways. In order to determine the importance of these pathways in the activity of the various enzymes that are important in maintaining the cellular cholesterol level in hepatic cells, we created HepG2 cells expressing lower levels of LDLr. Thus HepG2 cells were transfected with a constitutive expression vector (pRc/CMV) containing a fragment of LDLr cDNA inserted in an antisense manner. Stable transformants were obtained that showed significant reductions of 42, 72 and 85% of LDLr protein levels compared with the control, as demonstrated by immunoblotting and confirmed by the LDL binding assay. The best inactivation was achieved with the construct containing the first 0.7 kb of LDLr cDNA. Incubating the different HepG2 cell subtypes with LDL showed similar association of apolipoprotein B (apo B) or cholesteryl esters from LDL with the cells, indicating that the LDLr deficiency did not significantly affect LDL uptake by the cell. However, apoB degradation was reduced significantly by 71-82% in the most LDLr-deficient HepG2 cells. We also found that 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCoA red) activity is significantly increased by 32-35% in HepG2 cells expressing very low levels of LDLr that also demonstrate a significant decrease of 20% in acyl-CoA:cholesterol acyltransferase (ACAT) activity. However, these effects are moderate compared with those observed when cells were incubated in lipoprotein-depleted medium, where a > 900% increase in HMGCoA red activity and a loss of 60% of ACAT activity was observed. Thus, in HepG2 cells, different levels of LDLr affect LDL-apoB degradation, but have very little effect on LDL association, HMGCoA red and ACAT activities, revealing that LDLr is more important in the clearance of LDL-apoB than in HepG2 cell cholesterol homoeostasis, a role that should be attributable to both LDLr-dependent and -independent pathways.


2019 ◽  
Vol 5 (4) ◽  
pp. 237-245 ◽  
Author(s):  
Amir Abbas Momtazi-Borojeni ◽  
Sarvenaz Sabouri-Rad ◽  
Antonio M Gotto ◽  
Matteo Pirro ◽  
Maciej Banach ◽  
...  

AbstractProprotein convertase subtilisin/kexin Type 9 (PCSK9) is now identified as an important and major player in hypercholesterolaemia and atherosclerosis pathophysiology. PCSK9, through promoting lysosomal degradation of hepatic low-density lipoprotein (LDL) receptor, can decrease the clearance of plasma LDLs, leading to hypercholesterolaemia and consequent atherosclerotic plaque formation. Hypercholesterolaemia has been found to promote systemic and vascular inflammation, which can cause atherosclerotic lesion formation and progression and subsequent incidence of cardiovascular disease. Recent studies have shown the involvement of PCSK9 in the inflammatory pathway of atherosclerosis. Although trials with PCSK9 inhibitors have not shown any alteration in plasma C-reactive protein levels, there is accumulating evidence showing lessened inflammatory response in the arterial wall that could attenuate atherosclerotic plaque development beyond the established LDL-lowering effect of PCSK9 inhibition. In this review, we represent mounting evidence indicating that PCSK9 can locally increase vascular inflammation and contribute to atherosclerotic plaque progression in patients with hypercholesterolaemia.


2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Woong-Suk Yang ◽  
Jin-Chul Kim ◽  
Jae Yong Lee ◽  
Cheorl-Ho Kim ◽  
Cher-Won Hwang

The purpose of this study was to investigate antihyperlipidemic and antioxidative potentials of onion (Allium cepaL.) extract fermented with a novelLactobacillus caseiHD-010. In general, fermented onion extract is used for its antioxidative activity (ORAC), inhibitory effect on adipocytes differentiation, quercetin contents, and antihyperlipidemic activities. However, the effect of fermented onion extract on hyperlipidemia after oral administration using ApoE-deficient mice has not been reported yet. To understand the effect of fermented onion extract on hyperlipidemia, we used benzafibrate (10 mg/kg, bw/day) as a positive control in the present study. Serum was collected every week to analyze levels of low density lipoprotein (LDL), high density lipoprotein (HDL), triglyceride (TG), and cholesterol, 3-hydroxy-3-methylgutaryi-CoA (HMG-CoA) reductase activity, and cholesterol ester transport protein (CETP) activity. In the fermented onion-treated group, HDL level was significantly increased while levels of TG and LDL were significantly decreased compared to those in the control group. In addition, the inhibition activity of HMG-CoA reductase was increased 20% in the fermented onion-treated group at 100 mg/kg. CETP activity has been observed to be significantly inhibited in the fermented onion-treated groups compared to that in the control group. These results suggest that fermented onion has a preventive/therapeutic effect on hyperlipidemic disease. It might have potential to be developed as a functional food.


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