scholarly journals Ghrelin Interacts with Human Plasma Lipoproteins

Endocrinology ◽  
2007 ◽  
Vol 148 (5) ◽  
pp. 2355-2362 ◽  
Author(s):  
Carine De Vriese ◽  
Mirjam Hacquebard ◽  
Françoise Gregoire ◽  
Yvon Carpentier ◽  
Christine Delporte
Keyword(s):  
Platelet Activating Factor ◽  
Peptide Hormone ◽  
Hydrolytic Activity ◽  
High Density ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Rat Serum ◽  
Gh Secretion ◽  
Acyl Ghrelin

Ghrelin, a peptide hormone produced predominantly by the stomach, stimulates food intake and GH secretion. The Ser3 residue of ghrelin is mainly modified by a n-octanoic acid. In the human bloodstream, ghrelin circulates in two forms: octanoylated and desacylated. We previously demonstrated that ghrelin is desoctanoylated in human serum by butyrylcholinesterase (EC 3.1.1.8) and other esterase(s), whereas in rat serum, only carboxylesterase (EC 3.1.1.1) is involved. The aims of this study were to determine the role of lipoprotein-associated enzymes in ghrelin desoctanoylation and the role of lipoproteins in the transport of circulating ghrelin. Our results show that ghrelin desoctanoylation mostly occurred in contact with low-density lipoproteins (LDLs) and lipoprotein-poor plasma subfractions. Butyrylcholinesterase and platelet-activating factor acetylhydrolase (EC 3.1.1.47) were responsible for the ghrelin hydrolytic activity of the lipoprotein-poor plasma and LDL subfractions, respectively. Moreover, we observed that ghrelin is associated with triglyceride-rich lipoproteins (TRLs), high-density lipoproteins (HDLs), very high-density lipoproteins (VHDLs), and to some extent LDLs. In conclusion, we report that the presence of the acyl group is necessary for ghrelin interaction with TRLs and LDLs but not HDLs and VHDLs. Ghrelin interacts via its N- and C-terminal parts with HDLs and VHDLs. This suggests that, whereas TRLs mostly transport acylated ghrelin, HDLs and VHDLs transport both ghrelin and des-acyl ghrelin.

scholarly journals The Role of High Density Lipoproteins in Thrombosis

2002 ◽  
Vol 2 ◽  
pp. 89-95 ◽  
Author(s):  
Marina Cuchel ◽  
Daniel J. Rader
Keyword(s):  
Potential Role ◽  
Strong Association ◽  
Coagulation Factors ◽  
Scientific Data ◽  
High Density ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Anionic Phospholipids ◽  
Lipids And Lipoproteins

Lipids and lipoproteins, as well as factors involved in hemostasis and thrombosis, play a central role in the pathogenesis of cardio- and cerebrovascular disease. In recent years it has become clear that a strong association exists between coagulation factors and plasma lipoproteins. Anionic phospholipids are necessary for the optimal activity of both pro- and anticoagulant enzymatic complexes. Cell membranes have traditionally been considered to provide the essential lipid-containing surfaces. However, in light of recent studies, plasma lipoproteins are also believed to provide appropriate surfaces to support coagulation. While triglyceride-rich lipoproteins and oxidized low-density lipoproteins are associated with a procoagulant profile, high-density lipoproteins (HDL) may have an anticoagulant effect. This paper reviews scientific data on the potential role of HDL as modulator of thrombotic processes.

scholarly journals The analysis of interaction between lipoproteins and steroid hormones

2011 ◽  
Vol 57 (3) ◽  
pp. 308-313 ◽  
Author(s):  
L.M. Polyakov ◽  
D.V. Sumenkova ◽  
R.A. Knyazev ◽  
L.E. Panin
Keyword(s):  
Fluorescence Quenching ◽  
Steroid Hormones ◽  
Gel Filtration ◽  
High Density ◽  
Protein Component ◽  
Plasma Lipoproteins ◽  
High Density Lipoproteins ◽  
Apolipoprotein A ◽  
Main Protein

Using the methods of ultracentrifugation, gel-filtration and fluorescence quenching, we demonstrated, that plasma lipoproteins bind steroid hormones and can therefore play a role of their active transport form in an organism. High density lipoproteins have revealed the highest affinity to steroids for. It has been found, that protein component of lipoproteins takes part in the formation of lipoprotein-steroid complex. The apolipoprotein A-I, the main protein component of high density lipoproteins, is responsible for binding of steroid hormones. The calculated constants formation of the complexes of lipoproteins with steroid hormones testifies to specificity of linkage. The results obtained allow to considering real opportunity of transfer of steroid hormones into cell by a receptor-mediated endocytosis in structure of lipoproteins complexes.

scholarly journals Importance of Apolipoprotein A-I and A-II Composition in HDL and Its Potential for Studying COVID-19 and SARS-CoV-2

Medicines ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 38
Author(s):  
Kyung-Hyun Cho
Keyword(s):  
Antiviral Activity ◽  
High Density ◽  
High Density Lipoproteins ◽  
Potent Antiviral Activity ◽  
Apolipoprotein A ◽  
Putative Role

The composition and properties of apolipoprotein (apo) A-I and apoA-II in high-density lipoproteins (HDL) might be critical to SARS-CoV-2 infection via SR-BI and antiviral activity against COVID-19. HDL containing native apoA-I showed potent antiviral activity, while HDL containing glycated apoA-I or other apolipoproteins did not. However, there has been no report to elucidate the putative role of apoA-II in the antiviral activity of HDL.

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