scholarly journals Pretreatment of Asian elephant (Elephas maximus) spermatozoa with cholesterol-loaded cyclodextrins and glycerol addition at 4°C improves cryosurvival

2012 ◽  
Vol 24 (8) ◽  
pp. 1134 ◽  
Author(s):  
Wendy K. Kiso ◽  
Atsushi Asano ◽  
Alexander J. Travis ◽  
Dennis L. Schmitt ◽  
Janine L. Brown ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Culture Medium ◽  
Egg Yolk ◽  
Cholesterol Content ◽  
Asian Elephant ◽  
Elephas Maximus ◽  
Membrane Cholesterol ◽  
Captive Management ◽  
Sperm Survival ◽  
Cryopreservation Method

Asian elephant spermatozoa are sensitive to chilling and do not respond well to cryopreservation. The objectives of the present study were to: (1) determine whether cholesterol content can be modified by preincubation of Asian elephant spermatozoa with cholesterol-loaded cyclodextrin (CLC); and (2) assess the effects of CLC concentration(s), temperature at time of glycerol addition (22°C vs 4°C) and dilution medium on post-thaw sperm survival. Spermatozoa incubated with ≥1.5 mg CLC exhibited increased (P < 0.05) cholesterol concentrations. Pretreatment of spermatozoa with 1.5 mg CLC resulted in improvements (P < 0.05) in all post-thaw parameters. Glycerol addition at 4°C also improved all post-thaw parameters compared with 22°C. Dilution of thawed spermatozoa in an egg yolk-based medium improved (P < 0.05) motility compared with Ham’s F-10 culture medium. In summary, our findings indicate that modifying cholesterol content within the plasma membrane improves the cryosurvival of Asian elephant spermatozoa. The development of an improved cryopreservation method that includes modification of membrane cholesterol and the addition of glycerol at 4°C, as reported in the present study, is an important step towards utilisation of cryopreserved spermatozoa in captive management of this species.

scholarly journals Elevated Plasma Membrane Cholesterol Content Alters Macrophage Signaling and Function

2006 ◽  
Vol 26 (2) ◽  
pp. 372-378 ◽  
Author(s):  
Chunbo Qin ◽  
Tomokazu Nagao ◽  
Inna Grosheva ◽  
Frederick R. Maxfield ◽  
Lynda M. Pierini
Keyword(s):  
Plasma Membrane ◽  
Cholesterol Content ◽  
Membrane Cholesterol ◽  
Elevated Plasma ◽  
And Function ◽  
Plasma Membrane Cholesterol

scholarly journals Effects of plasma membrane cholesterol content on ultrasound and microbubble mediated sonoporation

2021 ◽  
Author(s):  
Tetyana Yatsenko
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Membrane Permeability ◽  
Cholesterol Content ◽  
Cell Membrane Permeability ◽  
Membrane Cholesterol ◽  
Intracellular Space ◽  
Plasma Membrane Cholesterol

Ultrasonically-stimulated microbubbles can increase cell membrane permeability and allow otherwise impermeable molecules to enter the intracellular space of cells; a phenomenon known as

Abstract 365: Inhibiting Hmg Coa Reductase Reduces Palmitate-Induced Inflammation in Adipocytes

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Asha K Pathak ◽  
Chang Yeop Han ◽  
Mohamed Omer ◽  
Shari Wang ◽  
Alan Chait
Keyword(s):  
Gene Expression ◽  
Plasma Membrane ◽  
Er Stress ◽  
Lipid Raft ◽  
Cholesterol Content ◽  
Membrane Cholesterol ◽  
Hmg Coa Reductase ◽  
Pre Treatment ◽  
Coa Reductase ◽  
Plasma Membrane Cholesterol

Adipose tissue inflammation associates with insulin resistance and increased cardiovascular disease risk. We previously observed that 3T3-L1 adipocytes exposed to palmitate become inflamed and demonstrate increased plasma membrane cholesterol and lipid raft content. It is known that palmitate induces translocation of NAPH oxidase and toll-like receptor 4 into lipid rafts, increasing adipocyte inflammation. However, it is unclear (1) how palmitate alters plasma membrane cholesterol content; and (2) whether increased cholesterol content in the plasma membrane is related to adipocyte inflammation induced by palmitate exposure. We hypothesize that mechanisms involved in increasing plasma membrane cholesterol content after palmitate treatment could be related to cholesterol synthesis and/or ER stress, and that increased cholesterol in lipid rafts is essential for induction of inflammation in adipocytes. To test these hypotheses, differentiated murine 3T3-L1 adipocytes were exposed to palmitate for 24 hours, with and without pre-treatment with HMG-CoA reductase inhibitors (statins) or HDL. RT-PCR was used to evaluate gene expression of inflammation ( Saa3 , Ccl2 ), ER stress ( Bip , Chop ), and HMG-CoA reductase ( Hmgcr ). Cholera toxin subunit β staining and flow cytometry were used to evaluate plasma membrane lipid raft content. In differentiated adipocytes, palmitate-induced inflammation neither increased expression of ER stress genes nor HMG-CoA reductase gene expression. However, treatment with 3 different statins (simvastatin, lovastatin, atorvastatin) significantly reduced palmitate-induced adipocyte inflammation as indicated by decreased gene expression of Saa3 and Ccl2 ( P <0.05). A similar effect was seen with pre-treatment with HDL. Lipid raft content induced by palmitate was decreased by HMG-CoA reductase inhibitors (difference in mean fluorescence intensity P <0.05) and also by pre-treatment with HDL. These findings indicate that ER stress was not involved in increased plasma membrane cholesterol after palmitate-induced inflammation in adipocytes. However, regulating cholesterol content in lipid rafts plays an important role in adipocyte inflammation induced by palmitate.

Structure of the Plasma Membrane of Uterine Epithelial Cells in Blastocyst Attachment: a Review

1992 ◽  
Vol 4 (6) ◽  
pp. 633 ◽  
Author(s):  
CR Murphy
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Tight Junction ◽  
Freeze Fracture ◽  
Membrane Skeleton ◽  
Cholesterol Content ◽  
Molecular Organization ◽  
Membrane Cholesterol ◽  
Uterine Receptivity ◽  
Uterine Epithelial Cells

Changes in the molecular organization of the plasma membrane of uterine epithelial cells during early pregnancy and, in particular, at the attachment period are reviewed. The review focuses on attachment in rodents but other species are also considered. Alterations in protein content and type, as determined with electrophoretic and freeze-fracture techniques, and an increase in tight junction complexity occur in several species. Ultrastructural histochemistry shows that glycocalyx carbohydrates of different species both increase and decrease depending on the type of carbohydrate. Changes in membrane cholesterol content also occur and recent studies showing major reorganization of the actin-containing membrane skeleton are reviewed to show the dynamism of this plasma membrane during the period of uterine receptivity for attachment of the blastocyst.

scholarly journals Differential Rhodopsin Regeneration in Photoreceptor Membranes is Correlated with Variations in Membrane Properties

1998 ◽  
Vol 18 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Kathleen Boesze-Battaglia ◽  
Cindy Allen
Keyword(s):  
Plasma Membrane ◽  
Time Course ◽  
Transmembrane Protein ◽  
Cholesterol Content ◽  
Receptor Activation ◽  
Membrane Properties ◽  
Membrane Cholesterol ◽  
Rod Cells ◽  
Disk Membrane

Rhodopsin, the major transmembrane protein in both the plasma membrane and the disk membranes of photoreceptor rod outer segments (ROS) forms the apo-protein opsin upon the absorption of light. In vivo the regeneration of rhodopsin is necessary for subsequent receptor activation and for adaptation, in vitro this regeneration can be followed after the addition of 11-cis retinal. In this study we investigated the ability of bleached rhodopsin to regenerate in the compositionally different membrane environments found in photoreceptor rod cells. When 11-cis retinal was added to bleached ROS plasma membrane preparations, rhodopsin did not regenerate within the same time course or to the same extent as bleached rhodopsin in disk membranes. Over 80% of the rhodopsin in newly formed disks regenerated within 90 minutes while only 40% regenerated in older disks. Since disk membrane cholesterol content increases as disks are displaced from the base to the apical tip of the outer segment, we looked at the affect of membrane cholesterol content on the regeneration process. Enrichment or depletion of disk membrane cholesterol did not alter the % rhodopsin that regenerated. Bulk membrane properties measured with a sterol analog, cholestatrienol and a fatty acid analog, cis parinaric acid, showed a more ordered, less “fluid”, lipid environment within plasma membrane relative to the disks. Collectively these results show that the same membrane receptor, rhodopsin, functions differently as monitored by regeneration in the different lipid environments within photoreceptor rod cells. These differences may be due to the bulk properties of the various membranes.

Membrane cholesterol and the regulation of signal transduction

2004 ◽  
Vol 32 (1) ◽  
pp. 65-69 ◽  
Author(s):  
C.J. Fielding ◽  
P.E. Fielding
Keyword(s):  
Signal Transduction ◽  
Plasma Membrane ◽  
Lipid Rafts ◽  
Mammalian Cells ◽  
Protein Composition ◽  
Cholesterol Content ◽  
Membrane Cholesterol ◽  
Transmembrane Signalling

The plasma membrane of mammalian cells consists of microdomains differing in lipid and protein composition. Two distinct classes of cholesterol/sphingolipid microdomain (caveolae and lipid rafts) are assembly points for transmembrane signalling complexes. Recent evidence suggests that transient changes in cholesterol content may be important in regulating signal transduction.

scholarly journals Alteration of Membrane Cholesterol Content Plays a Key Role in Regulation of Cystic Fibrosis Transmembrane Conductance Regulator Channel Activity

2021 ◽  
Vol 12 ◽  
Author(s):  
Guiying Cui ◽  
Kirsten A. Cottrill ◽  
Kerry M. Strickland ◽  
Sarah A. Mashburn ◽  
Michael Koval ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Plasma Membrane ◽  
Cholesterol Content ◽  
Membrane Cholesterol ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Channel Function ◽  
Rat Thyroid ◽  
Cystic Fibrosis Transmembrane ◽  
Plasma Membrane Cholesterol

Altered cholesterol homeostasis in cystic fibrosis patients has been reported, although controversy remains. As a major membrane lipid component, cholesterol modulates the function of multiple ion channels by complicated mechanisms. However, whether cholesterol directly modulates cystic fibrosis transmembrane conductance regulator (CFTR) channel function remains unknown. To answer this question, we determined the effects of changing plasma membrane cholesterol levels on CFTR channel function utilizing polarized fischer rat thyroid (FRT) cells and primary human bronchial epithelial (HBE) cells. Treatment with methyl-β-cyclodextrin (MβCD) significantly reduced total cholesterol content in FRT cells, which significantly decreased forskolin (FSK)-mediated activation of both wildtype (WT-) and P67L-CFTR. This effect was also seen in HBE cells expressing WT-CFTR. Cholesterol modification by cholesterol oxidase and cholesterol esterase also distinctly affected activation of CFTR by FSK. In addition, alteration of cholesterol increased the potency of VX-770, a clinically used potentiator of CFTR, when both WT- and P67L-CFTR channels were activated at low FSK concentrations; this likely reflects the apparent shift in the sensitivity of WT-CFTR to FSK after alteration of membrane cholesterol. These results demonstrate that changes in the plasma membrane cholesterol level significantly modulate CFTR channel function and consequently may affect sensitivity to clinical therapeutics in CF patients.

scholarly journals High-Fat and Resveratrol Supplemented Diets Modulate Adenosine Receptors in the Cerebral Cortex of C57BL/6J and SAMP8 Mice

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3040
Author(s):  
Alejandro Sánchez-Melgar ◽  
Pedro José Izquierdo-Ramírez ◽  
Verónica Palomera-Ávalos ◽  
Mercè Pallàs ◽  
José Luis Albasanz ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Plasma Membrane ◽  
Mouse Strain ◽  
Adenosine Receptors ◽  
Cholesterol Content ◽  
Membrane Cholesterol ◽  
High Fat ◽  
Underlying Mechanisms ◽  
Samp8 Mice ◽  
Plasma Membrane Cholesterol

Neurodegenerative disorders are devastating diseases in which aging is a major risk factor. High-fat diet (HFD) seems to contribute to cognition deterioration, but the underlying mechanisms are poorly understood. Moreover, resveratrol (RSV) has been reported to counteract the loss of cognition associated with age. Our study aimed to investigate whether the adeno-synergic system and plasma membrane cholesterol are modulated by HFD and RSV in the cerebral cortex of C57BL/6J and SAMP8 mice. Results show that HFD induced increased A1R and A2AR densities in C57BL/6J, whereas this remained unchanged in SAMP8. Higher activity of 5′-Nucleotidase was found as a common effect induced by HFD in both mice strains. Furthermore, the effect of HFD and RSV on A2BR density was different depending on the mouse strain. RSV did not clearly counteract the HFD-induced effects on the adeno-synergic system. Besides, no changes in free-cholesterol levels were detected in the plasma membrane of cerebral cortex in both strains. Taken together, our data suggest a different modulation of adenosine receptors depending on the mouse strain, not related to changes in plasma membrane cholesterol content.

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