Name: isolation and analysis of plasma lipoproteins by ultracentrifugation
Uploaded: 2021-01-28T15:00:00
Description: Watch this Scientific Journal Video about Isolation and Analysis of Plasma Lipoproteins by Ultracentrifugation at JoVE.com

This work was supported in part by a research grants from JSPS KAKENHI Grant Number JP 20K08858, the National Natural Science Foundation of China (No. 81941001 and 81770457), JSPS-CAS under the Japan-China Research Cooperative Program.

All procedures for rabbit studies were performed with approval of University of Yamanashi Institutional Animal Care and Use Committee (Approved number: A28-39).
1. Plasma separation from rabbit blood
<ol>
	<li>Prepare 1.5 mL microtubes containing 15 &#181;L of 0.5 M EDTA (pH 8.0) for blood collection.</li>
	<li>Put a rabbit in a restrainer and puncture an auricular intermediate artery using a 22 gauge needle and collect blood into a tube. Mix the blood with EDTA gently and put them on ice.</...

<ol>
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J., Lee, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipoprotein+Lipase+Inhibitor,+Nordihydroguaiaretic+Acid,+Aggravates+Metabolic+Phenotypes+and+Alters+HDL+Particle+Size+in+the+Western+Diet-Fed+db/db+Mice.">Lipoprotein Lipase Inhibitor, Nordihydroguaiaretic Acid, Aggravates Metabolic Phenotypes and Alters HDL Particle Size in the Western Diet-Fed db/db Mice.</a> International Journal of Molecular Sciences. 20 (12), 3057 (2019).</li><li>De Silva, H. 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Hyperlipidemia is one of the most important risk factors of atherosclerotic disease. Thus, analysis of plasma lipoproteins is not only essential for diagnosis of dyslipidemia patients but also important for investigation of molecular mechanisms of lipoprotein metabolism and atherosclerosis. In this study, we described the protocol of isolation and analysis of plasma lipoproteins which can be applied in the laboratories where ultracentrifugation is available. Information obtained by this method is comprehensive and straig...

Dyslipidemia is the major risk factor of atherosclerotic disease in the world. High levels of low-density lipoproteins (LDLs) and low levels of high-density lipoproteins (HDLs) are closely associated with a high risk of coronary heart disease (CHD)1,2. In the clinical setting, both LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) are routinely measured using an automated analyzer in a clinical laboratory3,4. Despite this, it is essential to analyze lipoprotein profiles in details for the diagnosis of dyslipidemia and the study of lipid metabolism and atherosclerosis in human and experimental animals. Several methods have been reported to analyze plasma lipoproteins such as ultracentrifugation, size exclusion chromatography [fast protein liquid chromatography (FPLC) and high performance liquid chromatography (HPLC)], electrophoresis by agarose and polyacrylamide gels, nuclear magnetic resonance, and selective chemical precipitation using polyanions and divalent cations or other chemicals. In 1950s, Havel&#8217;s group first proposed the concept of lipoproteins defined by densities using ultracentrifugation and classified them into chylomicrons (CM), very-low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), LDL, and HDL5 and later on, the method was further modified by other groups6,7. Until now, ultracentrifugation is the most popular and reliable method while the practical protocol is still not available. In this paper, we attempted to describe an easy-to-use protocol for isolating a small scale of plasma using sequential density floating ultracentrifugation originally described previously8. Isolation of seven plasma lipoprotein fractions [VLDL (d&#60;1.006 g/mL), IDL (d=1.02 g/mL), LDLs (d=1.04 and 1.06 g/mL), HDLs (d=1.08, 1.10, and 1.21 g/mL)] enables researchers to make an extensive analysis of both lipoproteins and their compositional apolipoproteins9,10,11. The intact seven consecutive density lipoproteins can be used for analyzing lipoprotein functions and also serving to&#160;cell-based in vitro strategies. This protocol should be useful for both clinical diagnosis and basic research. Here we used&#160;rabbit plasma as an example to demonstrate this technique while plasma from other species can be applied in the same way.

<table>
	<tbody>
		<tr>
			<td>22-gauge needle</td>
			<td>Terumo</td>
			<td>NN-2232S</td>
			<td>For blood collection</td>
		</tr>
		<tr>
			<td>96-well microplate</td>
			<td>greiner bio-one</td>
			<td>655101</td>
			<td>For lipids measurment</td>
		</tr>
		<tr>
			<td>Anti-apolipoprotein A-I antibody</td>
			<td>LifeSpan BioSciences</td>
			<td>LS-C314186</td>
			<td>For Western blottng, use 1:1,000</td>
		</tr>
		<tr>
			<td>Anti-apolipoprotein B antibody</td>
			<td>ROCKLAND</td>
			<td>600-101-111</td>
			<td>For Western blottng, use 1:1,000</td>
		</tr>
		<tr>
			<td>Anti-apolipoprotein E antibody</td>
			<td>Merck Millipore</td>
			<td>AB947</td>
			<td>For Western blottng, use 1:1,000</td>
		</tr>
		<tr>
			<td>CBB staining kit</td>
			<td>FUJIFILM Wako Pure Chemical</td>
			<td>299-50101</td>
			<td>For apolipoprotein analysis</td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>HITACHI</td>
			<td></td>
			<td>himac CF15RN</td>
		</tr>
		<tr>
			<td>Closure</td>
			<td>Spectrum</td>
			<td>132736</td>
			<td>For lipoprotein dialysis</td>
		</tr>
		<tr>
			<td>Dialysis tubing</td>
			<td>FUJIFILM Wako Pure Chemical</td>
			<td>043-30921</td>
			<td>For lipoprotein dialysis, MWCO 14,000</td>
		</tr>
		<tr>
			<td>Dry heat block</td>
			<td>Major Science</td>
			<td>MD-01N</td>
			<td>For SDS-PAGE sample preparation</td>
		</tr>
		<tr>
			<td>ECL Western blotting detection reagents</td>
			<td>GE Healthcare</td>
			<td>RPN2209</td>
			<td>For Western blotting</td>
		</tr>
		<tr>
			<td>Electrophoresis Chamber</td>
			<td>BIO-RAD</td>
			<td></td>
			<td>Mini-PROTEAN Tetra Cell</td>
		</tr>
		<tr>
			<td>Ethylenediamine-N,N,N&#39;,N&#39;-tetraacetic acid (EDTA) disodium salt dihydrate</td>
			<td>FUJIFILM Wako Pure Chemical</td>
			<td>345-01865</td>
			<td>For anticoagulant (0.5 M), for dialysis (1 mM)</td>
		</tr>
		<tr>
			<td>Filter paper</td>
			<td>ADVANTEC</td>
			<td>590</td>
			<td>For Western blotting</td>
		</tr>
		<tr>
			<td>Fixed angle ultracentrifuge rotor</td>
			<td>BECKMAN COULTER</td>
			<td>357656</td>
			<td>TLA-120.2</td>
		</tr>
		<tr>
			<td>Fixing solution</td>
			<td></td>
			<td></td>
			<td>For SDS-PAGE (50% Methanol/ 10% Acetic acid)</td>
		</tr>
		<tr>
			<td>Immun-Blot PVDF menbrane</td>
			<td>BIO-RAD</td>
			<td>1620177</td>
			<td>For Western blotting</td>
		</tr>
		<tr>
			<td>Lumino image analyzer</td>
			<td>GE Healthcare</td>
			<td></td>
			<td>For Western blotting, ImageQuant LAS 4000</td>
		</tr>
		<tr>
			<td>Magnetic stirrer</td>
			<td>ADVANTEC</td>
			<td>SR-304</td>
			<td>For lipoprotein dialysis</td>
		</tr>
		<tr>
			<td>Microplate reader iMARK</td>
			<td>BIO-RAD</td>
			<td></td>
			<td>For lipids measurment</td>
		</tr>
		<tr>
			<td>Microtube</td>
			<td>INA-OPTIKA</td>
			<td>SC-0150</td>
			<td></td>
		</tr>
		<tr>
			<td>Orbital agitator USBDbo</td>
			<td>Stovall Life Science</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Peroxidase congugated anti goat IgG antibody</td>
			<td>Jackson ImmunoResearch</td>
			<td>705-035-003</td>
			<td>For Western blotting, use 1:2,000</td>
		</tr>
		<tr>
			<td>Peroxidase congugated anti mouse IgG antibody</td>
			<td>Jackson ImmunoResearch</td>
			<td>715-035-150</td>
			<td>For Western blotting, use 1:2,000</td>
		</tr>
		<tr>
			<td>Phospholipids assay kit</td>
			<td>FUJIFILM Wako Pure Chemical</td>
			<td>433-36201</td>
			<td>For lipids measurment</td>
		</tr>
		<tr>
			<td>Polycarbonate ultracentrifuge Tubes</td>
			<td>BECKMAN COULTER</td>
			<td>343778</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium Bromide</td>
			<td>FUJIFILM Wako Pure Chemical</td>
			<td>168-03475</td>
			<td>For density solution</td>
		</tr>
		<tr>
			<td>Power Supply</td>
			<td>BIO-RAD</td>
			<td></td>
			<td>For SDD-PAGE and Western blotting, PowerPac 300, PowerPac HC</td>
		</tr>
		<tr>
			<td>Protein standards Precidion Plus Protein Dual Xtra</td>
			<td>BIO-RAD</td>
			<td>161-0377</td>
			<td>For SDS-PAGE and Western blotting</td>
		</tr>
		<tr>
			<td>Rabbit restrainer</td>
			<td>Natsume Seisakusho</td>
			<td>KN-318</td>
			<td>For blood collection</td>
		</tr>
		<tr>
			<td>Rotor</td>
			<td>HITACHI</td>
			<td></td>
			<td>T15A43</td>
		</tr>
		<tr>
			<td>SDS-PAGE running buffer</td>
			<td></td>
			<td></td>
			<td>25 mM Tris/ 192 mM Glycine/ 0.1% SDS</td>
		</tr>
		<tr>
			<td>SDS-PAGE sample buffer (2x)</td>
			<td></td>
			<td></td>
			<td>0.1M Tris-HCl (pH 6.8)/ 4% SDS/ 20% glycerol/ 0.01% BPB/12% 2-merpaptoethanol</td>
		</tr>
		<tr>
			<td>SDS-polyacrylamide gel</td>
			<td></td>
			<td></td>
			<td>4-20% gradient polyacrylamide gel</td>
		</tr>
		<tr>
			<td>Skim milk powder</td>
			<td>FUJIFILM Wako Pure Chemical</td>
			<td>190-12865</td>
			<td>For Western blotting blocking buffer (5% skim milk/ 0.1% Tween 20/ PBS)</td>
		</tr>
		<tr>
			<td>Total cholesterol assay kit</td>
			<td>FUJIFILM Wako Pure Chemical</td>
			<td>439-17501</td>
			<td>For lipids measurment</td>
		</tr>
		<tr>
			<td>Triglyicerides assay kit</td>
			<td>FUJIFILM Wako Pure Chemical</td>
			<td>432-40201</td>
			<td>For lipids measurment</td>
		</tr>
		<tr>
			<td>Tube slicer for thick-walled tube</td>
			<td>BECKMAN COULTER</td>
			<td>347960</td>
			<td>For lipoprotein isolation</td>
		</tr>
		<tr>
			<td>Tween 20</td>
			<td>SIGMA-ALDRICH</td>
			<td>P1379</td>
			<td>For Western blotting washing buffer (0.1% Tween 20/ PBS)</td>
		</tr>
		<tr>
			<td>Ultracentrifuge</td>
			<td>BECKMAN COULTER</td>
			<td>A95761</td>
			<td>Optima MAX-TL</td>
		</tr>
		<tr>
			<td>Western blotting wet transfer system</td>
			<td>BIO-RAD</td>
			<td></td>
			<td>Mini Trans-Blot Cell</td>
		</tr>
	</tbody>
</table>

isolation and analysis of plasma lipoproteins by ultracentrifugation

Analysis of plasma lipoproteins and apolipoproteins is an essential part for the diagnosis of dyslipidemia and studies of lipid metabolism and atherosclerosis. Although there are several methods for analyzing plasma lipoproteins, ultracentrifugation is still one of the most popular and reliable methods. Because of its intact separation procedure, the lipoprotein fractions isolated by this method can be used for analysis of lipoproteins, apolipoproteins, proteomes, and functional study of lipoproteins with cultured cells in vitro. Here, we provide a detailed protocol to isolate seven lipoprotein fractions including VLDL (d&#60;1.006 g/mL), IDL (d=1.02 g/mL), LDLs (d=1.04 and 1.06 g/mL), HDLs (d=1.08, 1.10, and 1.21 g/mL) from rabbit plasma using sequential floating ultracentrifugation. In addition, we introduce the readers how to analyze apolipoproteins such as apoA-I, apoB, and apoE by SDS-PAGE and Western blotting and show representative results of lipoprotein and apolipoprotein profiles using hyperlipidemic rabbit models. This method can become a standard protocol for both clinicians and basic scientists to analyze lipoprotein functions.

Using this protocol, we isolated rabbit lipoproteins using 1 mL of plasma and obtained seven density fractions. Isolated density fractions are enough for measuring lipids and apolipoproteins as described above for most research purposes. The same procedure can also be used for isolating plasma lipoproteins from human and other species. For small-sized animals such as mice, pooled plasma is required. Figure 3 shows lipoprotein profiles of wild-type (WT) rabbits fed either a normal standard (N...

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Isolation and Analysis of Plasma Lipoproteins by Ultracentrifugation

Several methods have been used for analyzing plasma lipoproteins; however, ultracentrifugation is still one of the most popular and reliable methods. Here, we describe a method regarding how to isolate lipoproteins from plasma using sequential density ultracentrifugation and how to analyze the apolipoproteins for both diagnostic and research purposes.

Analysis of plasma lipoproteins and apolipoproteins is an essential part for the diagnosis of dyslipidemia and studies of lipid metabolism and ...

Analysis of plasma lipoproteins is very important for the diagnosis of hyperlipidemia and the investigation of atherosclerosis. In is this protocol, we'll introduce the basic method using ultracentrifugation to isolate plasma lipoproteins. This method allows the researchers to use one milliliter of plasma to isolate seven lipoprotein fractions.These fractions can be used for the of lipids, apolipoproteins, as well as well-functional studies This method can be applied for both human and animal samples for the diagnosis of dyslipidemia and the related disease. Begin by transferring one milliliter of plasma into each polycarbonate ultracentrifuge tube. Then load the tubes in a fixed angle rotor and centrifuge the plasma at 356, 000 times G for 2.5 hours at four degrees Celsius.Adjust the position of the blade in the tube slicer to a level between the top fraction and the bottom fraction. Cut the tubes using a slicer and collect the top fraction, approximately 200 microliters, into a new micro tube. Collect the remaining bottom fraction into a new polycarbonate ultracentrifuge tube for the next separation.Adjust the total volume to 800 microliters by adding the same density solution. Adjust the bottom fraction to a density of 1.02 grams per milliliter by adding 58.9 microliters of 1.21 grams per milliliter solution, and 141.1 microliters of 1.02 grams per milliliter solution for a total volume of one milliliter. Load these tubes in the fixed angle rotor and centrifuge at 356, 000 times G for 2.5 hours at four degrees Celsius.Continue collecting top fractions, adjusting the density of bottom fractions, and centrifuging for fraction densities of 1.02, 1.04, 1.06, 1.08, 1.1, and 1.21 grams per milliliter. For the final ultracentrifugation, centrifuge at 513, 000 times G for four hours at four degrees Celsius. Lipoprotein profiles of rabbits fed either a normal standard diet or a high cholesterol diet are shown here.Rabbits are herbivores, so their plasma TC, TG, and PL levels are generally lower than those of humans and mice. In normal standard diet-fed rabbits, TC is mainly distributed in HDL3 and LDL. In wild type rabbits on a normal standard diet, 39%of plasma TG are distributed in VLDLs, whereas 57%of plasma PL is contained in HDL3.When rabbits were challenged with a high-cholesterol diet, they rapidly developed hypercholesterolemia. Their lipoprotein profiles were characterized by marked elevation of VLDLs. Seven lipoprotein fractions from wild type rabbits fed either a normal standard or a high-cholesterol diet were run on an SDS polyacrylamide gel and visualized with CBB staining.On a high-cholesterol diet, both ApoB-100 and ApoE contents in VLDLs, IDLs, and LDLs were markedly elevated. Western blotting was used to compare apolipoproteins and lipoprotein profiles of three different hyperlipidemic rabbits:high-cholesterol diet-fed wild type rabbits, ApoE knockout rabbits, and Watanabe Heritable Hyperlipidemic rabbits with LDL receptor deficiency. The ApoB containing particles of high-cholesterol diet-fed wild type rabbits are characterized by increased ApoB-100 and ApoE contents, whereas ApoE knockout rabbits showed an increase of ApoB-48 along with the appearance of ApoA-1.Watanabe Heritable Hyperlipidemic rabbits are genetically deficient in LDL receptor functions, so a marked increase of ApoB-100 in LDLs accompanied by reduced ApoA-1 in HDLs was observed, similar to human familial hypercholesterolemia patients. Sample recovery is the most critical in this procedure. To minimize sample loss, one should it be careful to collect fraction and completely dissolve viscous precipitation in the bottom fraction.After the collection of seven lipoprotein fractions, dialysis is require for the sorting. Once dialysis is complete, the lipoproteins samples for analysis using SDS page, western blotting, and cell-based study. In the clinical setting, ultracentrifugation usually separates lipoproteins into four fractions.The current method can isolate seven lipoproteins fractions, which provides more detail of lipoproteins for investigation of hyperlipidemia.

Research

JoVE Journal

Biochemistry

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