Abstract 583: RNAi Therapeutics For The Lowering Of Cholesterol

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Kevin Fitzgerald ◽  
Maria Frank-Kamenetsky ◽  
Tracy S Zimmermann ◽  
Jay Horton ◽  
Akin Akinc ◽  
...  
Keyword(s):  
Animal Models ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Small Interfering Rnas ◽  
Systemic Delivery ◽  
Apob Mrna ◽  
New Class ◽  
Safety Studies ◽  
Rnai Therapeutics

Delivery of small interfering RNAs (siRNAs) in vivo , using clinically relevant modes of administration, is critical for the advancement of RNA interference (RNAi) therapeutics. In this work, we demonstrate systemic delivery of siRNAs and potent in vivo down-modulation of two important disease targets, apolipoprotein B (apoB) and proprotein convertase subtilisin kexin 9 (PCSK9). A single injection of liposomal siRNA resulted in >90% silencing of apoB mRNA expression in the liver 48 h after administration. The effect was demonstrated to occur through cleavage of the apoB mRNA at precisely the site predicted for the RNAi mechanism. Reductions in apoB protein, cholesterol, and low-density lipoprotein (LDLc) levels were observed in 48 hours that lasted for at least 23 days, thus demonstrating an immediate, potent and durable biological effect. In addition to apoB we have also demonstrated the ability to down-modulate other important liver targets such as PCSK9. PCSK9 has been closely implicated in LDLc regulation. We have demonstrated PCSK9 down-modulation in several animal models including, mouse, humanized mouse, rat, and non-human primate. Down-modulation of PCSK9 levels resulted in significant lowering of cholesterol (20 – 60%) in all animal models tested. These findings strongly support the potential of RNAi therapeutics as a new class of drug for metabolic and cardiovascular diseases. Our next steps include selecting the most potent lead molecule and moving it into GLP safety studies.

scholarly journals Omentin-1 Modulates Macrophage Function via Integrin Receptors αvβ3 and αvβ5 and Reverses Plaque Vulnerability in Animal Models of Atherosclerosis

2021 ◽  
Vol 8 ◽  
Author(s):  
Xuze Lin ◽  
Yan Sun ◽  
Shiwei Yang ◽  
Mengyue Yu ◽  
Liu Pan ◽  
...  
Keyword(s):  
Animal Models ◽  
Inflammatory Cytokines ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Integrin Subunit ◽  
Integrin Receptors ◽  
Macrophage Function ◽  
Underlying Mechanisms ◽  
Pro Inflammatory Cytokines

Backgrounds: Omentin-1 is a novel cytokine that is primarily released by the epicardial adipose tissue. Molecular structure analysis revealed that it contained a fibrinogen-like domain. Clinical studies have demonstrated that the expression of omentin-1 is tightly associated with the development of cardiovascular diseases, but the receptor by which omentin-1 modulates macrophage function has not been identified yet.Objective: This study sought to investigate the effect of omentin-1 on already-established atherosclerosis (AS) lesions in both ApoE−/− and Ldlr−/− mice and further, study its underlying mechanisms.Methods and Results: We investigated the effect of omentin-1 on the plaque phenotype by implanting a minipump in ApoE−/− and Ldlr−/− mice. In vivo studies showed that the infusion of omentin-1 increased the collagen content and mitigated the formation of the necrotic core in both animal models. Immunohistochemistry and immunofluorescence analysis revealed that omentin-1 suppressed inflammatory cytokines expression, macrophage infiltration, and apoptosis within the plaque. An immunoprecipitation experiment and confocal microscopy analysis confirmed the binding of omentin-1 to the integrin receptors αvβ3 and αvβ5. The cell studies demonstrated that omentin-1 suppressed the apoptosis and inflammatory cytokines expression induced by the oxidized low-density lipoprotein in the macrophage. In addition, omentin-1 promoted the phosphorylation of the integrin-relevant signaling pathway as well as the Akt and AMPK in the macrophage. The addition of the inhibitor of the integrin receptor or interfering with the expression of the integrin subunit αv (ITGAV) both significantly abrogated the bioeffects induced by omentin-1. A flow cytometry analysis indicated that the antibodies against αvβ3 and αvβ5 had a competitive effect on the omentin-1 binding to the cell membrane.Conclusions: The administration of adipokine omentin-1 can inhibit the necrotic cores formation and pro-inflammatory cytokines expression within the AS lesion. The mechanisms may include the suppression of apoptosis and pro-inflammatory cytokines expression in the macrophage by binding to the integrin receptors αvβ3 and αvβ5.

scholarly journals Hepatic very-low-density lipoprotein and apolipoprotein B production are increased following in vivo induction of betaine–homocysteine S-methyltransferase

2006 ◽  
Vol 395 (2) ◽  
pp. 363-371 ◽  
Author(s):  
Janet D. Sparks ◽  
Heidi L. Collins ◽  
Doru V. Chirieac ◽  
Joanne Cianci ◽  
Jenny Jokinen ◽  
...  
Keyword(s):  
Apolipoprotein B ◽  
Serum Insulin ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Very Low Density Lipoprotein ◽  
Low Density ◽  
Mrna Levels ◽  
Apob Mrna ◽  
Hepatic Triacylglycerol

We have previously reported a positive correlation between the expression of BHMT (betaine–homocysteine S-methyltransferase) and ApoB (apolipoprotein B) in rat hepatoma McA (McArdle RH-7777) cells [Sowden, Collins, Smith, Garrow, Sparks and Sparks (1999) Biochem. J. 341, 639–645]. To examine whether a similar relationship occurs in vivo, hepatic BHMT expression was induced by feeding rats a Met (L-methionine)-restricted betaine-containing diet, and parameters of ApoB metabolism were evaluated. There were no generalized metabolic abnormalities associated with Met restriction for 7 days, as evidenced by control levels of serum glucose, ketones, alanine aminotransferase and L-homocysteine levels. Betaine plus the Met restriction resulted in lower serum insulin and non-esterified fatty acid levels. Betaine plus Met restriction induced hepatic BHMT 4-fold and ApoB mRNA 3-fold compared with Met restriction alone. No changes in percentage of edited ApoB mRNA were observed on the test diets. An increase in liver ApoB mRNA correlated with an 82% and 46% increase in ApoB and triacylglycerol production respectively using in vivo Triton WR 1339. Increased secretion of VLDL (very-low-density lipoprotein) with Met restriction plus betaine was associated with a 45% reduction in liver triacylglycerol compared with control. Nuclear run-off assays established that transcription of both bhmt and apob genes was also increased in Met-restricted plus betaine diets. No change in ApoB mRNA stability was detected in BHMT-transfected McA cells. Hepatic ApoB and BHMT mRNA levels were also increased by 1.8- and 3-fold respectively by betaine supplementation of Met-replete diets. Since dietary betaine increased ApoB mRNA, VLDL ApoB and triacylglycerol production and decreased hepatic triacylglycerol, results suggest that induction of apob transcription may provide a potential mechanism for mobilizing hepatic triacylglycerol by increasing ApoB available for VLDL assembly and secretion.

Oxidation of Plasma Low-Density Lipoprotein Accelerates Its Accumulation and Degradation in the Arterial Wall In Vivo

Circulation ◽  
1996 ◽  
Vol 94 (7) ◽  
pp. 1698-1704 ◽  
Author(s):  
Klaus Juul ◽  
Lars B. Nielsen ◽  
Klaus Munkholm ◽  
Steen Stender ◽  
Børge G. Nordestgaard
Keyword(s):  
Arterial Wall ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density

scholarly journals Interaction of 4-hydroxynonenal-modified low-density lipoproteins with the fibroblast apolipoprotein B/E receptor

1986 ◽  
Vol 234 (1) ◽  
pp. 245-248 ◽  
Author(s):  
W Jessup ◽  
G Jurgens ◽  
J Lang ◽  
H Esterbauer ◽  
R T Dean
Keyword(s):  
Apolipoprotein B ◽  
Negative Charge ◽  
Low Density Lipoprotein ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipid Peroxidation Product ◽  
Modified Low Density Lipoproteins ◽  
Peroxidation Product

The incorporation of the lipid peroxidation product 4-hydroxynonenal into low-density lipoprotein (LDL) increases the negative charge of the particle, and decreases its affinity for the fibroblast LDL receptor. It is suggested that this modification may occur in vivo, and might promote atherogenesis.

scholarly journals Biochemical and cytotoxic characteristics of an in vivo circulating oxidized low density lipoprotein (LDL-).

1994 ◽  
Vol 35 (4) ◽  
pp. 669-677
Author(s):  
H.N. Hodis ◽  
D.M. Kramsch ◽  
P. Avogaro ◽  
G. Bittolo-Bon ◽  
G. Cazzolato ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Oxidized Low Density Lipoprotein

scholarly journals Engineered ionizable lipid nanoparticles for targeted delivery of RNA therapeutics into different types of cells in the liver

2021 ◽  
Vol 7 (9) ◽  
pp. eabf4398
Author(s):  
M. Kim ◽  
M. Jeong ◽  
S. Hur ◽  
Y. Cho ◽  
J. Park ◽  
...  
Keyword(s):  
Cellular Uptake ◽  
Targeted Delivery ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipid Nanoparticles ◽  
Liver Sinusoidal Endothelial Cells ◽  
Main Challenge ◽  
Cell Type Specific ◽  
Selective Delivery

Ionizable lipid nanoparticles (LNPs) have been widely used for in vivo delivery of RNA therapeutics into the liver. However, a main challenge remains to develop LNP formulations for selective delivery of RNA into certain types of liver cells, such as hepatocytes and liver sinusoidal endothelial cells (LSECs). Here, we report the engineered LNPs for the targeted delivery of RNA into hepatocytes and LSECs. The effects of particle size and polyethylene glycol–lipid content in the LNPs were evaluated for the hepatocyte-specific delivery of mRNA by ApoE-mediated cellular uptake through low-density lipoprotein receptors. Targeted delivery of RNA to LSECs was further investigated using active ligands. Incorporation of mannose allowed the selective delivery of RNA to LSECs, while minimizing the unwanted cellular uptake by hepatocytes. These results demonstrate that engineered LNPs have great potential for the cell type–specific delivery of RNA into the liver and other tissues.

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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