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Purpose: Recent studies indicate that dysbiosis of gut microbiota and low-grade inflammation are important pathogenic determinants of type two diabetes mellitus (T2DM). The aim of this study is to investigate the effects of Lactobacillus GG on glycemic control, lipid profile, inflammatory parameters, and some gene expression levels in individuals with T2DM. Methods: In a randomized, placebo-controlled trial, 34 women, aged 30–60 years with T2DM consumed daily probiotics or placebo for 8 weeks. The probiotic group consumed 10 × 109 Cfu/day Lactobacillus rhamnosus GG ATCC 53,103 (LGG), approved by the TR Ministry of Food, Agriculture, and Livestock. Anthropometric measurements, food diary, fasting blood, and fecal samples were taken at baseline and post-treatment. Results: Fasting blood glucose was significantly decreased in probiotic (p = 0.049) and placebo (p = 0.028), but there was no difference between the groups. In the probiotic group, no significant difference was observed in HbA1c, fructosamine, lipid profile, and inflammatory variables compared to baseline. In this group, with LGG supplementation, mucin 2 and 3A (MUC2 and MUC3A) gene expressions increased more than ninefolds (p = 0.046 and p = 0.008, respectively) at post-treatment. Meanwhile, there was no significant change in any of the gene expressions in the placebo group. There was no significant difference in energy, protein, dietary fiber, and cholesterol intakes between placebo and probiotic groups during the study. However, daily fat intake (p = 0.003), body weight (p = 0.014), and body fat (p = 0.015) in the probiotic group were significantly decreased. Conclusion: In this study, the effects of a single probiotic strain were investigated for 8 weeks. At the end of the study, although there was no finding that clearly reflected on the glycemic parameters of T2DM, its beneficial effects on the expression of mucin genes, which are responsible for weight loss and protection of intestinal barrier functions, cannot be denied. Further studies are needed to reveal the importance of these findings. Clinical trial registration: ID: NCT05066152, October 4, 2021 retrospectively registered in ClinicalTrials.gov PRS web site. [ABSTRACT FROM AUTHOR]

Integrins are heterodimeric (αβ) cell surface receptors that are potential therapeutic targets for a number of diseases. Despite the existence of structural data for all parts of integrins, the structure of the complete integrin receptor is still not available. We have used available structural data to construct a model of the complete integrin receptor in complex with talin F2-F3 domain. It has been shown that the interactions of integrins with their lipid environment are crucial for their function but details of the integrin/lipid interactions remain elusive. In this study an integrin/talin complex was inserted in biologically relevant bilayers that resemble the cell plasma membrane containing zwitterionic and charged phospholipids, cholesterol and sphingolipids to study the dynamics of the integrin receptor and its effect on bilayer structure and dynamics. The results of this study demonstrate the dynamic nature of the integrin receptor and suggest that the presence of the integrin receptor alters the lipid organization between the two leaflets of the bilayer. In particular, our results suggest elevated density of cholesterol and of phosphatidylserine lipids around the integrin/talin complex and a slowing down of lipids in an annulus of ~30 Å around the protein due to interactions between the lipids and the integrin/talin F2-F3 complex. This may in part regulate the interactions of integrins with other related proteins or integrin clustering thus facilitating signal transduction across cell membranes. [ABSTRACT FROM AUTHOR]

AbstractCholesterol efflux from lipid-loaded cells is a key athero-protective event that counteracts cholesterol uptake. The imbalance between cholesterol efflux and uptake determines the prevention or development of atherosclerosis. Many proteins and factors participate in the cholesterol efflux event. However, there are currently no systematic models of reverse cholesterol transport (RCT) that include most RCT-related factors and events. On the basis of recent research findings from other and our laboratories, we propose a novel model of one center and four systems with coupling transportation and networking regulation. This model represents a common way of cholesterol efflux; however, the systems in the model consist of different proteins/factors in different cells. In this review, we evaluate the novel model in vascular smooth muscle cells (VSMCs) and macrophages, which are the most important original cells of foam cells. This novel model consists of 1) a caveolae transport center, 2) an intracellular trafficking system of the caveolin-1 complex, 3) a transmembrane transport system of the ABC-A1 complex, 4) a transmembrane transport system of the SR-B1 complex, and 5) an extracelluar trafficking system of HDL/Apo-A1. In brief, the caveolin-1 system transports cholesterol from intracellular compartments to caveolae. Subsequently, both ABC-A1 and SR-B1 complex systems transfer cholesterol from caveolae to extracellular HDL/Apo-A1. The four systems are linked by a regulatory network. This model provides a simple and concise way to understand the dynamic process of atherosclerosis. [ABSTRACT FROM AUTHOR]

The relative location of proteins and lipids in particles of medicinal leech salivary gland secretion (SGS) is revealed for the first time. Their sizes and morphology are described. Using scanning electron microscopy and transmission electron microscopy, it was determined that SGS consists of particles of different sizes and form. This picture is supported by confocal laser scanning microscopy of SGS preparations treated with fluorescein isothiocyanate. After incubation with nonionic detergents (Brij 35 and Tween 20), transmission electron microscopy revealed the dissociation of fragments composing protein-lipid particles (PLP), and in this case an increase in free protein concentration determined by a modification of the Lowry method was observed. Perylene probing of lipids in SGS preparations showed that they are concentrated mainly inside PLP and are almost absent on the surface. Cholesterol was detected during SGS probing using the cholesteryl-Bodipy (hydrophobic fluorescent analog of cholesterol) on surface sections during confocal analysis of electron microphotographs of SGS. This analysis detected PLP structures in SGS resembling caveoles full of cholesterol. SGS, preliminary frozen at −70°C, transformed into a multitude of similar small particles visualized by transmission electron microscopy, whose fixed distribution resembled water crystal structure. [ABSTRACT FROM AUTHOR]

Cholesterol, certain lipids, membrane-bound and soluble proteins, as well as viruses that are synthesized in the endoplasmic reticulum (ER), reach the plasma membrane (PM) via non-classical pathway(s) that remain poorly understood. Typical for this transport is (i) its insensitivity to brefeldin A (BFA), which dissociates selected coat complexes from membranes, resulting in the disassembly of the Golgi apparatus; (ii) its rapid kinetics as compared to the classical secretory pathway; and (iii) its role in the trafficking of lipid raft components. Based on results showing that the intermediate compartment (IC) at the ER-Golgi boundary constitutes a stable tubular network that maintains its dynamics in the presence of BFA, we propose that two bidirectional Golgi-bypass pathways to the PM exist, a direct route from early IC elements, and another, reminescent of the yeast secretory pathway, from late IC elements via the endosomal system. These pathways have implications for the organization of the secretory processes in different cell types. (Part of a Multi-author Review) [ABSTRACT FROM AUTHOR]

Enveloped viruses infect host cells by fusion of viral and target membranes. This fusion event is triggered by specific glycoproteins in the viral envelope. Fusion glycoproteins belong to either class I, class II or the newly described third class, depending upon their arrangement at the surface of the virion, their tri-dimensional structure and the location within the protein of a short stretch of hydrophobic amino acids called the fusion peptide, which is able to induce the initial lipid destabilization at the onset of fusion. Viral fusion occurs either with the plasma membrane for pH-independent viruses, or with the endosomal membranes for pH-dependent viruses. Although, viral fusion proteins are parted in three classes and the subcellular localization of fusion might vary, these proteins have to act, in common, on lipid assemblies. Lipids contribute to fusion through their physical, mechanical and/or chemical properties. Lipids can thus play a role as chemically defined entities, or through their preferential partitioning into membrane microdomains called “rafts”, or by modulating the curvature of the membranes involved in the fusion process. The purpose of this review is to make a state of the art on recent findings on the contribution of cholesterol, sphingolipids and glycolipids in cell entry and membrane fusion of a number of viral families, whose members bear either class I or class II fusion proteins, or fusion proteins of the recently discovered third class. [ABSTRACT FROM AUTHOR]

The two-month effects of dietary fish protein and casein on VLDL, HDL2 and HDL3 compositions and hepatic lipase (HTGL) and tissue lipoprotein lipase (LPL) activities were examined in spontaneously hypertensive rats (SHR) at 4 wk of age. After 2 mo of experiment, the fish protein diet induced lower blood pressure (-14 %) as compared to casein. Liver triacylglycerol and total cholesterol concentrations were 1.37- and 1.71-fold lower in the fish protein group than in the casein group, respectively. Total cholesterol concentration in plasma was also diminished by fish protein (-21 %) and was reflected in HDL2 fraction (-44 %). SHR fed the fish protein diet as compared with those fed casein, showed a significantly low HDL3 particle number, as measured by diminished HDL3 mass and apo A-I. The consumption of fish protein did not affect VLDL particle number, but significantly decreased VLDL-triacylglycerol (-32 %) and adipose tissue total lipid concentrations as compared to casein. This was accompanied by diminished HTGL and adipose tissue LPL activities (-10%, -91%, respectively). These data demonstrate that fish protein plays an antihypertensive role and reduces plasma and tissue lipid concentrations. Thus, a fish protein intake might be beneficial for patients with hypertension. [ABSTRACT FROM AUTHOR]

NAP-22, a major protein of neuronal rafts is known to preferentially bind to membranes containing cholesterol. In this work we establish the requirements for membrane binding of NAP-22. We find that other sterols can replace cholesterol to promote binding. In addition, bilayers containing phosphatidylethanolamine bind NAP-22 in the absence of cholesterol. Thus, there is not a specific interaction of NAP-22 with cholesterol that determines its binding to membranes. Addition of a mol fraction of phosphatidylserine of 0.05 to membranes of phosphatidylcholine and cholesterol enhances the membrane binding of NAP-22. The dependence of binding on the mol fraction of phosphatidylserine indicates that NAP-22 binds to membranes with its amino-terminal segment closer to the membrane than the remainder of the protein. We have also determined which segments of NAP-22 are required for membrane binding. A non-myristoylated form binds only weakly to membranes. Truncating the protein from 226 amino acids to the myristoylated aminoterminal 60 amino acids does not prevent binding to membranes in a cholesterol-dependent manner, but this binding is of weaker affinity. However, myristoylation is not sufficient to promote binding to cholesterol-rich domains. An N-terminal 19-amino-acid, myristoylated peptide binds to membranes but without requiring specific lipids. Thus, the remainder of the protein contributes to the lipid specificity of the membrane binding of NAP-22. [ABSTRACT FROM AUTHOR]

Here, to study lipid-protein interactions that contribute to the biogenesis of regulated secretory vesicles, we have developed new approaches by which to label proteins in vivo, using photoactivatable cholesterol and glycerophospholipids. We identify synaptophysin as a major specifically cholesterol-binding protein in PC12 cells and brain synaptic vesicles. Limited cholesterol depletion, which has little effect on total endocytic activity, blocks the biogenesis of synaptic-like microvesicles (SLMVs) from the plasma membrane. We propose that specific interactions between cholesterol and SLMV membrane proteins, such as synaptophysin, contribute to both the segregation of SLMV membrane constituents from plasma-membrane constituents, and the induction of synaptic-vesicle curvature. [ABSTRACT FROM AUTHOR]

Serum biochemical parameters are important aspects in the management of endangered species such as Acipenser persicus and Acipenser stellatus. Serum samples of 14 juvenile A. persicus and A. stellatus were analyzed and their serum parameter values were determined as mean ± SD in both groups. We compared the levels of phospholipid (26.73–42.79 mmol/L), triglyceride (2.38–2.37 mmol/L), total cholesterol (3.04–3.55 mmol/L), total lipid (32.09–50.11 mmol/L), total protein (32.22–27.78 g/L), albumin (7.25–6.85 g/L), globulin (24.86–20.62 g/L), Alb:Glb ratio (0.39–0.18), glucose (7.45 mmol/L), and free fatty acid (110.25–32.58 mg/L) in the two species. We have shown that there was no difference between groups in terms of any parameters ( p > 0.05). [ABSTRACT FROM AUTHOR]

Focuses on the importance of the association of proteins with lipid rafts, which are regions of the plasma membrane enriched in cholesterol and glycosphingolipids. Effect of the asymmetrical migration of T lymphocytes on lipid rafts; Information on lipid-raft-associated gangliosides that are distributed in the leading edge and rear edge of polarized T cells; List of leading edge- and unropodspecific markers.

Offers information on research on the localization of cholesterol-binding proteins caveolins to intracellular lipid droplets. Reference to studies by A. Pol, et al, by A. G. Ostermeyer, et al, and by T. Fujimoto, et al; Mechanism of action of caveolin-3; Intracellular route of overexpressed caveolin.