Abstract P420: Nano-Triciribine Reduces SARS2-CoV-2 Infection By Sequestering ACE2 And The Novel Host Factor LDLR

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Jose Manuel Condor Capcha ◽  
Camila Iansen Irion ◽  
Guerline Lambert ◽  
Ahmed Chahdi ◽  
Peter Buchwald ◽  
...  
Keyword(s):  
Viral Entry ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Airway Epithelial Cells ◽  
Host Factor ◽  
Phase Iii ◽  
Cell Surface Expression ◽  
Intranasal Delivery ◽  
Akt Inhibitor ◽  
Novel Host

Background: People with previous CVD hospitalized for COVID-19 have elevated death rate. We reported that patients with diabetes and HF higher protein levels of the low density lipoprotein receptor (LDLR). We hypothesized that LDLR is a novel host factor for the SARS-CoV-2-Spike (S2S) protein that may be regulated by the Akt inhibitor Triciribine (TCN), a drug being tested in Phase III studies for breast cancer. We also hypothesized that nano-formulation of Triciribine (NanoTriciribine; NTCN) would enhance its efficacy and allow for intranasal delivery. Methods: Interactions between the recombinant proteins Spike-RBD (receptor binding domain), ACE2, LDLR and its ectodomains (EGFA-EFFB, C2-C5 and C2) were analyzed by binding assays and co-IP in HepG2, HK2, and 293T cells. Viral entry assays were performed with 2 S2S pseudoviruses using 293T cells + hACE2 and TMPRSS2 or Furin protease. The effect of NTCN or the LXR agonist GW-3965 on viral uptake (pseudotyped VSVΔG-GFP*S2S or chimera VSV-S2S-eGFP virus) was assessed. Akt, pAkt, ACE2, and LDLR levels were determined in 293T+hACE2 by flow cytometry. Assays were done in triplicates and 1-way-ANOVA with Tukey’s correction was used for statistics. Results: RBD protein binds modestly to the human LDLR (EC 50 :10μM) and its C2-C5 ectodomain (EC 50 :13.8μM). Co-IP revealed a novel and strong LDLR-ACE2 interaction in several human cell lines. LDLR overexpression in human cells increased the uptake of VSVΔG-GFP*S2S (FC=2.32;p<0.001) and chimera virus (FC=.33; p<.0001). NTCN and TCN each reduced pAkt/Akt ratio. 1μM TCN or NTCN reduced LDLR (7.2%;p<.01 & 15.6%;p<0.0001) and ACE2 (32%;p<0.05 & 44.7%;p<.01) cell surface expression, respectively. 1μM NTCN or GW-3965 reduced S2S viral entry by 64.2% (p<.0001) and 40.7% (p<.01), respectively, confirming a role for LDLR in S2S infection. In hACE2tg mice, chimera VSV-S2S caused significant lung infection as measured by qPCR, GFP expression in proximal and distal lung airway epithelial cells, and electron microscopy. Intranasal delivery of NTCN was well tolerated. Conclusions: LDLR enhanced S2S viral entry supporting the elevated COVID-19 susceptibility seen in patients with heart disease. NTCN is a promising candidate for prophylactic treatment against COVID-19.

Clinical implications and outcomes of the ORION Phase III trials

2020 ◽  
Author(s):  
Julia Brandts ◽  
Kausik K Ray
Keyword(s):  
Familial Hypercholesterolemia ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Phase Iii ◽  
Atherosclerotic Cardiovascular Disease ◽  
Low Density Lipoprotein Cholesterol ◽  
Clinical Safety ◽  
Phase Iii Trials ◽  
Phase Ii And Iii ◽  
Ongoing Phase

Inclisiran is a siRNA inhibiting hepatic PCSK9 synthesis. As a first-in-class therapy, inclisiran has been assessed within the ORION trial program for its low-density lipoprotein cholesterol (LDL-C) lowering efficacy and clinical safety. Phase II and III trials have shown that inclisiran lowers LDL-C by about 50% with an infrequent dosing schedule in patients with established atherosclerotic cardiovascular disease and those at high risk, including patients with heterozygous familial hypercholesterolemia. Ongoing Phase III trials will provide evidence on longer-term safety and effectiveness, and inclisiran’s efficacy in patients with homozygous familial hypercholesterolemia. Furthermore, the ORION-4 trial will assess inclisiran’s impact on cardiovascular outcomes.

scholarly journals Triciribine Engages ZFP36L1 and HuR to Stabilize LDLR mRNA

Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4505
Author(s):  
Hilde Sundvold
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Low Density Lipoprotein ◽  
Ring Finger ◽  
Density Lipoprotein ◽  
Dependent Manner ◽  
Akt Inhibitor ◽  
Human Hepatoma Cells ◽  
Density Lipoprotein Receptor ◽  
The Stability

An increased understanding of low-density lipoprotein receptor (LDLR) and its regulation may facilitate drug development for the treatment of hypercholesterolemia. Triciribine (TCN), which is a highly selective AKT inhibitor, increases the stability of LDLR mRNA downstream of extracellular signal-regulated kinase (ERK) in human hepatoma cells (HepG2). Here, a candidate approach was used in order to determine whether the RNA-binding proteins (RBPs) ZFP36 ring finger protein like 1 (ZFP36L1) and Hu antigen R (HuR) play a role in TCN-mediated stabilization of LDLR mRNA. The depletion of HuR led to a reduction of LDLR mRNA stability, an event that was more pronounced in TCN-treated cells. TCN was found to induce the translocation of nuclear HuR to cytoplasm in an ERK-dependent manner. ZFP36L1 depletion increased the stability of LDLR mRNA consistent with its destabilizing role. However, in contrast to HuR, TCN had no effect on LDLR mRNA turnover in ZFP36L1-depleted cells. TCN induced the phosphorylation of ZFP36L1 in an ERK/RSK-dependent manner and promoted its dissociation from the CCR4-NOT complex. In sum, these data suggest that TCN utilizes ERK signaling to increase the activity of HuR and inhibit ZFP36L1 to stabilize LDLR mRNA in HepG2 cells.

scholarly journals The Low-Density Lipoprotein Class A Module of the Relaxin Receptor (Leucine-Rich Repeat Containing G-Protein Coupled Receptor 7): Its Role in Signaling and Trafficking to the Cell Membrane

Endocrinology ◽  
2007 ◽  
Vol 148 (3) ◽  
pp. 1181-1194 ◽  
Author(s):  
András Kern ◽  
Alexander I. Agoulnik ◽  
Gillian D. Bryant-Greenwood
Keyword(s):  
Cell Surface ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Lipoprotein Class ◽  
Class A ◽  
Relaxin Family ◽  
G Protein Coupled ◽  
Relaxin Receptor

The relaxin receptor (LGR7, relaxin family peptide receptor 1) is a member of the leucine-rich repeat containing G protein-coupled receptors subgroup C. This and the LGR8 (relaxin family peptide receptor 2) receptor are unique in having a low-density lipoprotein class A (LDL-A) module at their N termini. This study was designed to show the role of the LDL-A in LGR7 expression and function. Point mutants for the conserved cysteines (Cys47 and Cys53) and for calcium binding asparagine (Asp58), a mutant with deleted LDL-A domain and chimeric LGR7 receptor with LGR8 LDL-A all showed no cAMP response to human relaxins H1 or H2. We have shown that their cell surface delivery was uncompromised. The mutation of the putative N-linked glycosylation site (Asn36) decreased cAMP production and reduced cell surface expression to 37% of the wild-type LGR7. All point mutant, chimeric, and wild-type receptor proteins were expressed as the two forms. The immature or precursor form of the receptor was 80 kDa, whereas the mature receptor, delivered to the cell surface was 95 kDa. The glycosylation mutant was also expressed as two forms with appropriately smaller molecular masses. Deletion of the LDL-A module resulted in expression of the mature receptor only. These data suggest that the LDL-A module of LGR7 influences receptor maturation, cell surface expression, and relaxin-activated signal transduction.

scholarly journals Characterization of Hepatitis C Virus (HCV) and HCV E2 Interactions with CD81 and the Low-Density Lipoprotein Receptor

2000 ◽  
Vol 74 (21) ◽  
pp. 10055-10062 ◽  
Author(s):  
Sabina Wünschmann ◽  
Jheem D. Medh ◽  
Donna Klinzmann ◽  
Warren N. Schmidt ◽  
Jack T. Stapleton
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Confocal Microscopy ◽  
Viral Entry ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Protein Synthesis Inhibitor ◽  
Low Density ◽  
E2 Protein ◽  
Intermediate Density

ABSTRACT Hepatitis C virus (HCV) or HCV–low-density lipoprotein (LDL) complexes interact with the LDL receptor (LDLr) and the HCV envelope glycoprotein E2 interacts with CD81 in vitro. However, E2 interactions with LDLr and HCV interactions with CD81 have not been clearly described. Using sucrose gradient-purified low-density particles (1.03 to 1.07 g/cm3), intermediate-density particles (1.12 to 1.18 g/cm3), recombinant E2 protein, or control proteins, we assessed binding to MOLT-4 cells, foreskin fibroblasts, or LDLr-deficient foreskin fibroblasts at 4°C by flow cytometry and confocal microscopy. Viral entry was determined by measuring the coentry of α-sarcin, a protein synthesis inhibitor. We found that low-density HCV particles, but not intermediate-density HCV or controls bound to MOLT-4 cells and fibroblasts expressing the LDLr. Binding correlated with the extent of cellular LDLr expression and was inhibited by LDL but not by soluble CD81. In contrast, E2 binding was independent of LDLr expression and was inhibited by human soluble CD81 but not mouse soluble CD81 or LDL. Based on confocal microscopy, we found that low-density HCV particles and LDL colocalized on the cell surface. The addition of low-density HCV but not intermediate-density HCV particles to MOLT-4 cells allowed coentry of α-sarcin, indicating viral entry. The amount of viral entry also correlated with LDLr expression and was independent of the CD81 expression. Using a solid-phase immunoassay, recombinant E2 protein did not interact with LDL. Our data indicate that E2 binds CD81; however, virus particles utilize LDLr for binding and entry. The specific mechanism by which HCV particles interact with LDL or the LDLr remains unclear.

The Role of Statin Therapy in Primary Hyperlipidemia and Mixed Dyslipidemia

2011 ◽  
Vol 07 (01) ◽  
pp. 23 ◽  
Author(s):  
Sergio Fazio ◽  
Keyword(s):  
Risk Factors ◽  
Low Density Lipoprotein ◽  
Age Groups ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Phase Iii ◽  
Cvd Risk ◽  
Mixed Dyslipidemia ◽  
The Us ◽  
Coa Reductase

In the US, ischemic cardiovascular disease (CVD) and stroke combined are the major cause of death for all age groups older than 55 years. Preventive approaches are based on the management of all risk factors and co-morbidities. The management guidelines for the lipid risk factors focus on lowering low-density lipoprotein cholesterol (LDL-C) levels. Statins, which inhibit cholesterol synthesis via blockade of the enzyme 3-hydroxy-3-methylglutaryl co-enzyme A (HMG-CoA) reductase, are the drug of choice for LDL-C control. Currently, there are three generic and four branded statins. Pitavastatin, the latest statin to be approved by the US Food and Drug Administration (FDA) (2009), has the lipid indications of the other statins but is not indicated for CVD risk reduction. It is available in 1 mg, 2 mg, and 4 mg doses, with the recommended starting dose of 2 mg being equivalent to 20 mg of simvastatin and 10 mg of atorvastatin, and superior to 20 mg of pravastatin. Pitavastatin 2 mg reduces LDL-C levels by 39 %, apolipoprotein B by 31 %, total cholesterol by 28 % and triglycerides by 16 %, and raises high-density lipoprotein cholesterol (HDL-C) by 6 %. In phase III clinical trials, pitavastatin 4 mg decreases LDL-C by up to 45 %. Pitavastatin has a unique metabolism, with little processing by cytochrome P450 (CYP) and none by CYP3A4, and thus it may display less CYP-mediated drug interaction than other statins. However, the FDA has determined that pitavastatin should not be taken with cyclosporine. Pitavastatin should be limited to 1 mg daily with erythromycin and 2 mg daily with rifampin. Preliminary vascular investigations have suggested benefits in line with those obtained by other statins.

scholarly journals Long-Term Efficacy and Safety of Pemafibrate, a Novel Selective Peroxisome Proliferator-Activated Receptor-α Modulator (SPPARMα), in Dyslipidemic Patients with Renal Impairment

2019 ◽  
Vol 20 (3) ◽  
pp. 706 ◽  
Author(s):  
Koutaro Yokote ◽  
Shizuya Yamashita ◽  
Hidenori Arai ◽  
Eiichi Araki ◽  
Hideki Suganami ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Phase Iii ◽  
Peroxisome Proliferator ◽  
Low Density ◽  
Open Label ◽  
Peroxisome Proliferator Activated Receptor ◽  
Blood Concentrations ◽  
Cholesterol Levels

Pemafibrate (K-877) is a novel selective peroxisome proliferator-activated receptor-α modulator (SPPARMα) with a favorable benefit-risk balance. Previous clinical trials of pemafibrate used stringent exclusion criteria related to renal functions. Therefore, we investigated its safety and efficacy in a broader range of patients, including those with chronic kidney disease (CKD). In this multicenter, single-arm, open-label, phase III trial, 0.2–0.4 mg/day pemafibrate was administered for 52 weeks to 189 patients with hypertriglyceridemia and an estimated glomerular filtration rate (eGFR) ≥ 45 mL/min/1.73 m2 on statin or regardless of eGFR when statin was not administered. Post-hoc analyses were performed on subgroups stratified by baseline eGFR. Triglyceride levels decreased by 45.9% at week 52 (last-observation-carried-forward). These reductions were not correlated with baseline eGFR. The eGFR < 30 mL/min/1.73 m2 subgroup showed the greatest reduction in chylomicron, very low-density lipoprotein, small low-density lipoprotein cholesterol levels, and an increase in high-density lipoprotein cholesterol levels. The incidences of adverse events and adverse drug reactions were 82.0% and 31.7%, respectively, and these were not associated with baseline eGFR. In CKD patients, pemafibrate blood concentrations were not elevated. Pemafibrate showed a good safety profile and efficacy in correcting lipid abnormalities in a broad range of patients, including those with CKD.

scholarly journals Differential gene expression by RNA-Seq in Sigma-2 Receptor/TMEM97 knockout cells reveals its role in complement activation and SARS-CoV-2 viral uptake

2021 ◽  
Author(s):  
Aladdin Riad ◽  
Yann Aubert ◽  
Chenbo Zeng ◽  
Thomas J. A. Graham ◽  
E. James Petersson ◽  
...  
Keyword(s):  
Viral Entry ◽  
Intrinsically Disordered Proteins ◽  
Transmembrane Protein ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Disordered Proteins ◽  
Angiotensin Converting Enzyme 2 ◽  
Intrinsically Disordered ◽  
Density Lipoprotein Receptor ◽  
Complement Component 4

Our lab has recently shown that the Sigma-2 Receptor/Transmembrane Protein 97 (sigma- 2R/TMEM97) interacts with the low-density lipoprotein receptor (LDLR) and facilitates the enhanced uptake of various ligands including lipoproteins and intrinsically disordered proteins. TMEM97 has been recently been shown to interact with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral proteins, highlighting its potential involvement with viral entry into the cell. We hypothesized that sigma-2R/TMEM97 may play a role in facilitating viral uptake, and with the regulation of inflammatory and thrombotic pathways that are involved with viral infection. In this study, we identified the top differentially expressed genes upon the knockout of sigma-2R/TMEM97, and analyzed the genes involved with the inflammatory and thrombotic cascades, effects that are observed in patients infected with SARS-CoV-2. We found that the ablation of sigma-2R/TMEM97 resulted in an increase in Complement Component 4 Binding Protein (C4BP) proteins, at both the translational and transcriptional levels. We also showed that sigma-2R/TMEM97 interacts with the cellular receptor for SARS-CoV-2, the human angiotensin-converting enzyme 2 (ACE2) receptor, forming a protein complex, and that disruption of this complex results in the inhibition of viral uptake. The results of this study suggest that sigma-2R/TMEM97 may be a novel therapeutic target to inhibit SARS- CoV-2 viral uptake, as well as to decrease inflammatory and thrombotic effects through the modulation of the complement cascade.

scholarly journals Targeting pro-protein convertase subtilisin kexin-9 as a novel therapy of hypercholesterolemia

2017 ◽  
Vol 26 (2) ◽  
pp. 152-7
Author(s):  
Bambang Dwiputra ◽  
Anwar Santoso ◽  
Kian K. Poh
Keyword(s):  
Ldl Cholesterol ◽  
Competitive Inhibition ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
High Plasma ◽  
Phase Iii ◽  
Loss Of Function ◽  
Novel Therapy ◽  
Phase Iii Clinical Trials

Reducing low density lipoprotein (LDL) cholesterol level is an established primary and secondary prevention strategy for coronary heart disease. However, not all patients are able to achieve their LDL targets as recommended by the guidelines. Over the last 10 years, high plasma LDL level is known to be associated with a higher level of pro-protein convertase subtilisin kexin-9 (PCSK-9). Loss-of-function mutations in the PCSK-9 gene is associated with lower plasma LDL level and cardiovascular risk. Since its discovery in 2003, PCSK-9 has triggered many researchers to design a PCSK-9 inhibitor to reduce LDL cholesterol through competitive inhibition of this molecule. Some phase III clinical trials have showed promising results of PCSK-9 inhibitor efficacy in lowering LDL level and improving clinical outcome. This article aims to discuss the role of PCSK-9 in LDL metabolism and the efficacy of PCSK-9 inhibitor in reducing plasma LDL level.

Serum and Low-Density Lipoprotein Enhance Interleukin-8 Secretion by Airway Epithelial Cells

2003 ◽  
Vol 29 (4) ◽  
pp. 483-489 ◽  
Author(s):  
James E. Gern ◽  
Rebecca Brockman-Schneider ◽  
Saswati Bhattacharya ◽  
James S. Malter ◽  
William W. Busse
Keyword(s):  
Epithelial Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Airway Epithelial Cells ◽  
Interleukin 8 ◽  
Low Density ◽  
Airway Epithelial

scholarly journals The Adaptor Protein ARH Escorts Megalin to and through Endosomes

2003 ◽  
Vol 14 (12) ◽  
pp. 4984-4996 ◽  
Author(s):  
Masaaki Nagai ◽  
Timo Meerloo ◽  
Tetsuro Takeda ◽  
Marilyn Gist Farquhar
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Adaptor Protein ◽  
Adaptor Proteins ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Coated Pits ◽  
Recycling Endosomes ◽  
Early Endosomes ◽  
Autosomal Recessive Hypercholesterolemia

Megalin is an endocytic receptor that binds multiple ligands and is essential for many physiological processes such as brain development and uptake of proteins by the kidney tubule, yolk sac, and thyroid. The cytoplasmic tail of megalin contains two FXNPXY motifs. Autosomal recessive hypercholesterolemia (ARH) is an adaptor protein that binds to the FXNPXY motif of the low-density lipoprotein receptor as well as clathrin and AP-2. We found that ARH also binds to the first FXNPXY motif of megalin in two-hybrid, pull-down and coimmunoprecipitation assays. ARH colocalizes with megalin in clathrin coated pits and in recycling endosomes in the Golgi region. When cells are treated with nocodazole, the recycling endosomes containing megalin and ARH disperse. On internalization of megalin, ARH and megalin are first seen in clathrin coated pits followed by sequential localization in early endosomes and tubular recycling endosomes in the pericentriolar region followed by their reappearance at the cell surface. Expression of ARH in Madin-Darby canine kidney cells expressing megalin mini-receptors enhances megalin-mediated uptake of125I-lactoferrin, a megalin ligand. These results show that ARH facilitates endocytosis of megalin, escorts megalin along its endocytic route and raise the possibility that transport through the endosomal system is selective and requires interaction with specific adaptor proteins.

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