scholarly journals Inhibition of low-density lipoprotein receptor degradation with a cyclic peptide that disrupts the homodimerization of IDOL E3 ubiquitin ligase

2018 ◽  
Vol 9 (27) ◽  
pp. 5957-5966 ◽  
Author(s):  
Eilidh K. Leitch ◽  
Nagarajan Elumalai ◽  
Maria Fridén-Saxin ◽  
Göran Dahl ◽  
Paul Wan ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Cyclic Peptide ◽  
Low Density Lipoprotein ◽  
E3 Ubiquitin Ligase ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Low Density Lipoprotein Receptor ◽  
Density Lipoprotein Receptor

A cyclic peptide IDOL homodimerization inhibitor identified from a genetically encoded SICLOPPS library is active in vitro and in cells.

scholarly journals Low-Density Lipoprotein Receptor-Mediated Lipidome-Transcriptome Reprogramming Impulses to Cisplatin Insensitivity

2018 ◽  
Author(s):  
Wei-Chun Chang ◽  
Hsiao-Ching Wang ◽  
Wei-Chung Cheng ◽  
Juan-Cheng Yang ◽  
Wei-Min Chung ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Low Density Lipoprotein Receptor ◽  
Bioinformatics Analyses ◽  
Density Lipoprotein Receptor ◽  
Cisplatin Sensitivity

Platinum-based therapy remains the cornerstone for cancer patient management; however, its efficacy varies. This study demonstrated the differential expressions of low-density lipoprotein receptor (LDLR) in subtypes of epithelial ovarian carcinoma (EOC) determines cisplatin sensitivity. It's sensitive in serous EOCs (low LDLR), where insensitive in endometrioid and clear cell EOCs (high LDLR). Meanwhile, knocked-down or overexpressed LDLR in EOC could reversed the chemosensitivity pattern both in vitro and in vivo. Mechanistic dissection with transcriptome vs. lipidome trans-omics analyses elucidated the LDLR-->LPC (Lyso-PhosphotidylCholine)-->FAM83B (phospholipase-related)-->FGFRs (cisplatin sensitivity and phospholipase-related) regulatory axis in cisplatin insensitivity. Implementing LPC-liposome encapsulated cisplatin could facilitate DNA-adduct formation via lipid droplets (LDs) delivery. Furthermore, Bioinformatics analyses found that the LDL/R-->LD homeostasis alteration is critical for therapeutic prognosis. Lastly, using LPC-liposome-cisplatin improved cisplatin sensitivities in gastric cancer, renal cell carcinoma, hepatocellular carcinoma, cholangiocarcinoma, and pancreatic adenocarcinoma cells. In conclusion, this report discovered a LDL/R-reprogrammed transcriptome-lipidome network, by which impulses platinum insensitivity and disease outcome. The drug specific lipidome for liposome manufacture might be an efficienct pharmaceutics strategy for chemoagents.

scholarly journals The low-density-lipoprotein receptor-related protein (LRP) is processed by furin in vivo and in vitro

1996 ◽  
Vol 313 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Thomas E. WILLNOW ◽  
Joan M. MOEHRING ◽  
Noel M. INOCENCIO ◽  
Thomas J. MOEHRING ◽  
Joachim HERZ
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Proteolytic Processing ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Related Protein ◽  
Low Density Lipoprotein Receptor ◽  
Density Lipoprotein Receptor ◽  
Lipoprotein Receptor Related Protein

The low-density-lipoprotein receptor-related protein (LRP) is a multifunctional receptor involved in the clearance of a large number of diverse ligands, including proteases, protease-inhibitor complexes and lipoproteins. The mature receptor is composed of a 515 kDa and a 85 kDa subunit generated by proteolytic cleavage from a 600 kDa precursor polypeptide in a trans-Golgi compartment. Proteolytic processing occurs C-terminal to the tetrabasic amino acid sequence RHRR, a consensus recognition site for precursor processing endoproteases or convertases. In this study we have identified furin, a subtilisin-type protease, to be necessary for efficient processing of LRP in cells. Furin-deficient RPE.40 cells exhibited an impaired processing of endogenous LRP and of a recombinant soluble form of the receptor containing the processing site. The processing defect in RPE.40 cells could be complemented by expression of furin from a transfected cDNA in cultured cells and by purified furin in vitro. The impaired maturation of LRP in RPE.40 cells did not affect its intracellular transport, and correlated with a slight but consistent reduction in the endocytosis of LRP-specific ligands. These data suggest that proteolytic processing of LRP by furin is not necessary for intracellular trafficking but might be required for normal receptor activity.

scholarly journals Elevating Endogenous Sphingosine-1-Phosphate (S1P) Levels Improves Endothelial Function and Ameliorates Atherosclerosis in Low Density Lipoprotein Receptor-Deficient (LDL-R−/−) Mice

2018 ◽  
Vol 118 (08) ◽  
pp. 1470-1480 ◽  
Author(s):  
Renata Feuerborn ◽  
Manuela Besser ◽  
Francesco Potì ◽  
Ralph Burkhardt ◽  
Gabriele Weißen-Plenz ◽  
...  
Keyword(s):  
Endothelial Function ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Low Density ◽  
Lipoprotein Receptor ◽  
Low Density Lipoprotein Receptor ◽  
Atherosclerotic Lesions ◽  
Density Lipoprotein Receptor ◽  
Sphingosine 1 Phosphate

Background Sphingosine-1-phosphate (S1P) is a bioactive lysosphingolipid and a constituent of high-density lipoprotein (HDL) exerting several atheroprotective effects in vitro. However, the few studies addressing anti-atherogenic effects of S1P in vivo have led to disparate results. We here examined atherosclerosis development in low-density lipoprotein receptor (LDL-R)-deficient (LDL-R−/−) mice with elevated endogenous S1P levels. Methods and Results Sub-lethally irradiated LDL-R−/− mice were transplanted with bone marrow deficient in sphingosine kinase 2 (SphK2), which led to the elevation of S1P concentrations in erythrocytes, plasma and HDL by approximately 1.5- to 2.0-fold in SphK2−/−/LDL-R−/− mice. Afterwards, mice were fed a Western diet for 14 weeks. Elevation of endogenous S1P significantly reduced atherosclerotic lesion formation by approximately half without affecting the plasma lipid profile. Furthermore, the macrophage content of atherosclerotic lesions and lipopolysaccharide-induced monocyte recruitment to the peritoneal cavity were reduced in SphK2−/−/LDL-R−/− mice. Studies using intra-vital microscopy revealed that endogenous S1P lowered leukocyte adhesion to capillary wall and decreased endothelial permeability to fluorescently labelled LDL. Moreover, SphK2−/−/LDL-R−/− mice displayed decreased levels of vascular cell adhesion molecule 1 in atherosclerotic lesions and in plasma. Studies in vitro demonstrated reduced monocyte adhesion and transport across an endothelial layer exposed to increasing S1P concentrations, murine plasma enriched in S1P or plasma obtained from SphK2-deficient animals. In addition, decreased permeability to fluorescence-labelled dextran beads or LDL was observed in S1P-treated endothelial cells. Conclusion We conclude that raising endogenous S1P levels exerts anti-atherogenic effects in LDL-R−/− mice that are mediated by favourable modulation of endothelial function.

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