Biomedical Spectroscopy and Imaging - Volume 5, issue s1

Authors: Haris, Parvez I.

Article Type: Editorial

DOI: 10.3233/BSI-160161

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. s1, pp. S1-S3, 2016

Authors: Sorensen, Aaron A. | Weedon, David

Article Type: Review Article

Abstract: We have compiled a list of the 100 most cited articles in cholesterol research to assess research trends over the last 10 and 100 years to mark the 200th anniversary of the naming of cholesterol as part of the special issue of Biomedical Spectroscopy and Imaging .

Keywords: Cholesterol

DOI: 10.3233/BSI-160160

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. s1, pp. S5-S43, 2016

Authors: Wu, Rui-Guang | Sun, Hai-Yuan | Zhao, Bao-Sheng | Deng, Geng | Yu, Zhi-Wu

Article Type: Research Article

Abstract: Structural properties of paeonol-encapsulated liposomes containing cholesterol or stigmasterol at 37°C have been investigated by synchrotron small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS) techniques. We compared the structural properties of pure dipalmitoylphosphatidylcholine (DPPC) liposomes, sterol–DPPC liposomes, and those of paeonol–sterol–DPPC liposomes at different molar ratios. Three conclusions can be drawn: First, phase separation occurs in both sterol–DPPC and paeonol–sterol–DPPC liposomes. Second, the incorporation of paeonol molecules into sterol–DPPC liposomes weakens the membrane order. Third, cholesterol has a stronger tendency to interact with DPPC as compared to its counterpart in plant, stigmasterol.

Keywords: Paeonol, cholesterol, stigmasterol, liposomes, synchrotron X-ray diffraction, phase separation

DOI: 10.3233/BSI-160162

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. s1, pp. S45-S54, 2016

Authors: Kumar, G. Aditya | Chattopadhyay, Amitabha

Article Type: Review Article

Abstract: Cholesterol, an essential component of higher eukaryotic membranes, was discovered more than two centuries ago. The development and progress of cholesterol research in the last 200 years has been truly fascinating, with elements of surprise, serendipity and intrigue. In this review, we trace this journey the way we see it, and follow it up with the role of membrane cholesterol in crucial areas of contemporary research (transbilayer domains, regulation of GPCR function and role in the entry of intracellular pathogens into host cells), with considerable footprint from our work. We believe that cholesterol will continue to surprise and fascinate future …researchers, thereby justifying its evergreen nature. Show more

Keywords: Membrane cholesterol, transbilayer dimer, G protein-coupled receptor, pathogen entry

DOI: 10.3233/BSI-160159

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. s1, pp. S55-S66, 2016

Authors: Barrantes, Francisco J.

Article Type: Research Article

Abstract: Once the sterol biosynthetic machinery had progressed over the course of several million years to yield cholesterol, this neutral lipid became an omnipresent and essential component of biomembranes in Eukaryotes. The hopanoids in Prokaryotes and eukaryotic sterols share the ability to provide stability and domain compartmentalization in membranes. Even more important is the intimate association of cholesterol with a wide range of cell-surface membrane proteins, probably responsible for its modulatory effects on neurotransmitter and hormone receptors and ion channels. These effects appear to be exerted via the membrane-embedded segments of essentially all members of the pentameric ligand-gated ion channel and …G-protein-coupled receptor superfamilies, which possess consensus linear arrays of amino acid residues recognizing cholesterol with relatively high affinity and specificity, an early evolutionary acquisition already present in ancient bacteria, conserved, and further improved in Eukaryotes. This review focuses on the long-term relationship between cholesterol and these functionally important membrane protein superfamilies, and the ability of cholesterol to induce lateral segregation and ordered domain formation at the nanoscale in cell membranes. Show more

Keywords: Cholesterol, cholesterol-recognition motifs, neurotransmitter receptor, ion channels, phylogenomics, sterol evolution, cholesterol–protein interactions, membrane proteins, neurotransmitter receptors, pentameric ligand-gated ion channels, evolution

DOI: 10.3233/BSI-160158

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. s1, pp. S67-S86, 2016

Authors: Raniolo, Sofia | Vindigni, Giulia | Biocca, Silvia

Article Type: Review Article

Abstract: Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), the primary receptor for ox-LDL in endothelial cells, is a multi-ligand scavenger receptor that plays a crucial role in the pathogenesis of atherosclerosis and cardiovascular disorders and recently identified as a tumor marker. LOX-1 is naturally present in caveolae/lipid rafts in plasma membranes and disruption of these membrane domains by cholesterol-lowering drugs leads to a spatial disorganization of LOX-1 and a marked loss of specific LOX-1 function in terms of ox-LDL binding and internalization. Moreover, cholesterol depletion triggers the release of LOX-1 in exosomes and enhances shedding of LOX-1 ectodomain. We here provide …an overview of the involvement of membrane and circulating cholesterol in LOX-1 function and shedding and its impact on cardiovascular pathologies and cancer. In particular, we consider the available biological and molecular evidence indicating LOX-1 as a potential therapeutic target for atherosclerosis, inflammation processes, myocardial infarction and cholesterol-lowering drugs as specific inhibitors of LOX-1 function. Show more

Keywords: Cholesterol, LOX-1 receptor, ox-LDL, lipid rafts, MβCD, statins

DOI: 10.3233/BSI-160156

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. s1, pp. S87-S99, 2016

Authors: de Oliveira Andrade, Luciana

Article Type: Research Article

Abstract: Cholesterol is an important component of cell plasma membrane. Due to its chemical composition (long rigid hydrophobic chain and a small polar hydroxyl group), it fits most of its structure into the lipid bilayer, where its steroid rings are in close proximity and attracted to the hydrocarbon chains of neighboring lipids. This gives a condensing effect on the packing of lipids in cell membranes creating cholesterol-enriched regions called membrane rafts, which also congregate a lot of specific proteins. Membrane rafts have been shown to work as platforms involved with signaling in diverse cellular processes, such as immune regulation, cell cycle …control, membrane trafficking and fusion events. A series of studies in the last two decades have linked many of these functions with the effects of membrane cholesterol content and rafts integrity on actin cytoskeleton organization, as well as its consequences in cellular biomechanics. This was possible by using microscopy techniques before and after manipulation of cholesterol content from cell plasma membrane, using agents that are able to sequester these molecules, such as cyclodextrins. In this review we’ll give a personal perspective on these studies and how microscopy techniques were important to unravel the effects of cholesterol on actin and cellular mechanics. We will also discuss how actin and cholesterol contributes to control cell secretion and vesicular trafficking. Show more

Keywords: Cholesterol, cell biomechanics, membrane trafficking, confocal microscopy, atomic force microscopy, laser tweezers, defocusing microscopy

DOI: 10.3233/BSI-160157

Citation: Biomedical Spectroscopy and Imaging, vol. 5, no. s1, pp. S101-S117, 2016