scholarly journals NPC1L1 Facilitates Sphingomyelin Absorption and Regulates Diet-Induced Production of VLDL/LDL-associated S1P

Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2641
Author(s):  
Yoshihide Yamanashi ◽  
Tappei Takada ◽  
Hideaki Yamamoto ◽  
Hiroshi Suzuki
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Cholesterol Absorption ◽  
In Vivo Studies ◽  
Lipid Mediator ◽  
Low Density ◽  
Dependent Manner ◽  
Niemann Pick

Niemann-Pick C1-Like 1 (NPC1L1) is a cholesterol importer and target of ezetimibe, a cholesterol absorption inhibitor used clinically for dyslipidemia. Recent studies demonstrated that NPC1L1 regulates the intestinal absorption of several fat-soluble nutrients, in addition to cholesterol. The study was conducted to reveal new physiological roles of NPC1L1 by identifying novel dietary substrate(s). Very low-density lipoprotein and low-density lipoprotein (VLDL/LDL) are increased in Western diet (WD)-fed mice in an NPC1L1-dependent manner, so we comprehensively analyzed the NPC1L1-dependent VLDL/LDL components. Apolipoprotein M (apoM), a binding protein of sphingosine-1-phosphate (S1P: a lipid mediator), and S1P were NPC1L1-dependently increased in VLDL/LDL by WD feeding. S1P is metabolized from sphingomyelin (SM) and SM is abundant in WD, so we focused on intestinal SM absorption. In vivo studies with Npc1l1 knockout mice and in vitro studies with NPC1L1-overexpressing cells revealed that SM is a physiological substrate of NPC1L1. These results suggest a scenario in which dietary SM is absorbed by NPC1L1 in the intestine, followed by SM conversion to S1P and, after several steps, S1P is exported into the blood as the apoM-bound form in VLDL/LDL. Our findings provide insight into the functions of NPC1L1 for a better understanding of sphingolipids and S1P homeostasis.

Some metabolic characteristics of low-density lipoprotein subfractions, LDL-1 and LDL-2: in vitro and in vivo studies

1988 ◽  
Vol 960 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Dorine W. Swinkels ◽  
Pierre N.M. Demacker ◽  
Heidi L.M. Hak-Lemmers ◽  
Marc J.T.M. Mol ◽  
Sing H. Yap ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
In Vivo Studies ◽  
Low Density ◽  
Lipoprotein Subfractions ◽  
Metabolic Characteristics

scholarly journals Synthetic nanoemulsion resembling a protein-free model of 7-ketocholesterol containing low density lipoprotein: In vitro and in vivo studies

2010 ◽  
Vol 43 (4) ◽  
pp. 439-444 ◽  
Author(s):  
Giovani M Favero ◽  
Raul C Maranhão ◽  
Durvanei A Maria ◽  
Débora Levy ◽  
Sérgio P Bydlowski
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
In Vivo Studies ◽  
Low Density ◽  
Free Model

Scavenging of Reactive Oxygen Species and Inhibition of the Oxidation of Low Density Lipoprotein by the Aqueous Extraction ofAnoectochilus formosanus

2003 ◽  
Vol 31 (01) ◽  
pp. 25-36 ◽  
Author(s):  
Chun-Ching Shih ◽  
Yueh-Wern Wu ◽  
Wen-Chuan Lin
Keyword(s):  
Reactive Oxygen Species ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Reactive Oxygen ◽  
In Vivo Studies ◽  
Ldl Oxidation ◽  
Low Density ◽  
Dependent Manner ◽  
Oxygen Species

The ability of Anoectochilus formosanus extract (AFE) to react with relevant biological oxidants was evaluated in this study. In addition, its effect on oxidation of low density lipoprotein (LDL) was investigated in vitro and in vivo. AFE could scavenge reactive oxygen species, such as superoxide anion and hydroxyl radical. The study of human LDL oxidation showed that AFE delayed oxidation in a concentration-dependent manner. In vivo studies also showed that oral administration of AFE delayed the oxidation of LDL from hyperlipidemic hamsters. The ability of AFE to scavenge free radicals suggests that it may be a promising anti-atherogenic agent.

In vitro, in vivo studies of a new amphiphilic adsorbent for the removal of low-density lipoprotein

Biomaterials ◽  
2003 ◽  
Vol 24 (13) ◽  
pp. 2189-2194 ◽  
Author(s):  
Yan Cheng ◽  
Shenqi Wang ◽  
Yaoting Yu ◽  
Yi Yuan
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
In Vivo Studies ◽  
Low Density

scholarly journals Non-oxidative modification of native low-density lipoprotein by oxidized low-density lipoprotein

1996 ◽  
Vol 316 (2) ◽  
pp. 377-380 ◽  
Author(s):  
Min YANG ◽  
David S. LEAKE ◽  
Catherine A. RICE-EVANS
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Oxidative Modification ◽  
Low Density ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Process Studies

The oxidative modification of low-density lipoprotein (LDL) has been implicated in the pathogenesis of atherosclerosis, although little is known as yet about the precise mechanism of oxidation in vivo. The studies presented here demonstrate that, in the absence of cells or transition metals, oxidized LDL can modify native LDL through co-incubation in vitro such as to increase its net negative charge, in a concentration-dependent manner. The interaction is not inhibited by peroxyl radical scavengers or metal chelators, precluding the possibility that the modification of native LDL by oxidized LDL is through an oxidative process. Studies with radioiodinated oxidized LDL showed no transfer of radioactivity to the native LDL, demonstrating that fragmentation of protein and the transfer of some of the fragments does not account for the modified charge on the native LDL particle. The adjacency of native to oxidized LDL in the arterial wall may be a potential mechanism by which the altered recognition properties of the apolipoprotein B-100 may arise rapidly without oxidation or extensive modification of the native LDL lipid itself.

Transfer of newly made triglyceride from hepatocytes to preexisting extracellular very low density lipoproteins

1987 ◽  
Vol 65 (3) ◽  
pp. 337-343
Author(s):  
Gen Yoshino ◽  
George Steiner
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Liver Cells ◽  
Low Density Lipoproteins ◽  
In Vivo Studies ◽  
Low Density ◽  
Very Low Density Lipoproteins ◽  
Apoprotein B

Previous in vivo studies suggested a new model to describe the metabolism of very low density lipoproteins (VLDL). It was hypothesized that some of the lipoprotein triglyceride was transferred directly from hepatocytes and intestinal mucosal cells into preexisting extracellular VLDL particles. These studies employ an in vitro system to test this hypothesis. Isolated rat liver cells containing newly made radioactive triglyceride were prepared. These cells were incubated in medium to which exogenous VLDL had or had not been added. The presence of extracellular VLDL (rat or human) stimulated the transfer of labeled triglyceride out of the liver cells. This triglyceride was recovered in the medium's VLDL (as determined by its density and its precipitability by MnCl2–heparin or by anti-apoprotein B). Although these studies focussed on VLDL, preliminary data showed that similar triglyceride transfer occurred in the presence of the other apoprotein B containing lipoprotein, low density lipoprotein (LDL). However, in the presence of equivalent amounts of LDL, this triglyceride transfer was less than that seen in the presence of exogenous VLDL. Furthermore, the increased triglyceride released in the presence of LDL occurred entirely in the d < 1.006 fraction of the medium. That released in the presence of VLDL was recovered in the d > 1.006 fraction. Hence, we conclude that the transfer of the newly made triglyceride was from the cell to the extracellular lipoprotein that had been added to the medium. The transfer of triglyceride to VLDL did not depend on the synthesis and release of new VLDL particles because it was not accompanied by a change in the production of [14C]leucine VLDL protein, it was not blocked by chloroquine, and the LDL induced triglyceride release occurred into the d > 1.006 fraction. This transfer did not depend on the previously described triglyceride-transfer factor. The present in vitro studies support the model suggested by our earlier in vivo studies. The VLDL particle does not appear to be metabolized as a complete intact unit. Rather, some of its major lipid component, triglyceride, can move directly into and out of already existing extracellular lipoproteins.

scholarly journals Reductions of copper ion-mediated low-density lipoprotein (LDL) oxidations of trypsin inhibitors, the sweet potato root major proteins, and LDL binding capacities

2020 ◽  
Vol 61 (1) ◽  
Author(s):  
Yeh-Lin Lu ◽  
Chia-Jung Lee ◽  
Shyr-Yi Lin ◽  
Wen-Chi Hou
Keyword(s):  
Sweet Potato ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Trypsin Inhibitors ◽  
Water Soluble ◽  
Affinity Column ◽  
Low Density ◽  
Native Page

Abstract Background The root major proteins of sweet potato trypsin inhibitors (SPTIs) or named sporamin, estimated for 60 to 80% water-soluble proteins, exhibited many biological activities. The human low-density lipoprotein (LDL) showed to form in vivo complex with endogenous oxidized alpha-1-antitrypsin. Little is known concerning the interactions between SPTIs and LDL in vitro. Results The thiobarbituric-acid-reactive-substance (TBARS) assays were used to monitor 0.1 mM Cu2+-mediated low-density lipoprotein (LDL) oxidations during 24-h reactions with or without SPTIs additions. The protein stains in native PAGE gels were used to identify the bindings between native or reduced forms of SPTIs or soybean TIs and LDL, or oxidized LDL (oxLDL). It was found that the SPTIs additions showed to reduce LDL oxidations in the first 6-h and then gradually decreased the capacities of anti-LDL oxidations. The protein stains in native PAGE gels showed more intense LDL bands in the presence of SPTIs, and 0.5-h and 1-h reached the highest one. The SPTIs also bound to the oxLDL, and low pH condition (pH 2.0) might break the interactions revealed by HPLC. The LDL or oxLDL adsorbed onto self-prepared SPTIs-affinity column and some components were eluted by 0.2 M KCl (pH 2.0). The native or reduced SPTIs or soybean TIs showed different binding capacities toward LDL and oxLDL in vitro. Conclusion The SPTIs might be useful in developing functional foods as antioxidant and nutrient supplements, and the physiological roles of SPTIs-LDL and SPTIs-oxLDL complex in vivo will investigate further using animal models.

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