Role of Gangliosides and Plasma Membrane-Associated Sialidase in the Process of Cell Membrane Organization

2011 ◽  
pp. 297-316 ◽  
Author(s):  
Sandro Sonnino ◽  
Vanna Chigorno ◽  
Massimo Aureli ◽  
Anie Priscilla Masilamani ◽  
Manuela Valsecchi ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Membrane Organization

scholarly journals Adipoclast: a multinucleated fat-eating macrophage

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Antoni Olona ◽  
Subhankar Mukhopadhyay ◽  
Charlotte Hateley ◽  
Fernando O. Martinez ◽  
Siamon Gordon ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Plasma Membrane ◽  
Cell Membrane ◽  
Cell Fusion ◽  
Metabolic Activity ◽  
Current Knowledge ◽  
Giant Cells ◽  
Multinucleated Giant Cells ◽  
Review Current

AbstractCell membrane fusion and multinucleation in macrophages are associated with physiologic homeostasis as well as disease. Osteoclasts are multinucleated macrophages that resorb bone through increased metabolic activity resulting from cell fusion. Fusion of macrophages also generates multinucleated giant cells (MGCs) in white adipose tissue (WAT) of obese individuals. For years, our knowledge of MGCs in WAT has been limited to their description as part of crown-like structures (CLS) surrounding damaged adipocytes. However, recent evidence indicates that these cells can phagocytose oversized lipid remnants, suggesting that, as in osteoclasts, cell fusion and multinucleation are required for specialized catabolic functions. We thus reason that WAT MGCs can be viewed as functionally analogous to osteoclasts and refer to them in this article as adipoclasts. We first review current knowledge on adipoclasts and their described functions. In view of recent advances in single cell genomics, we describe WAT macrophages from a ‘fusion perspective’ and speculate on the ontogeny of adipoclasts. Specifically, we highlight the role of CD9 and TREM2, two plasma membrane markers of lipid-associated macrophages in WAT, which have been previously described as regulators of fusion and multinucleation in osteoclasts and MGCs. Finally, we consider whether strategies aiming to target WAT macrophages can be more selectively directed against adipoclasts.

Role of hepatocyte plasma membrane in insulin degradation

1985 ◽  
Vol 248 (2) ◽  
pp. E194-E202
Author(s):  
W. G. Blackard ◽  
C. Ludeman ◽  
J. Stillman
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Trichloroacetic Acid ◽  
Rat Hepatocytes ◽  
Inhibitory Effect ◽  
Insulin Degradation ◽  
Compensatory Increase ◽  
Cultured Rat Hepatocytes ◽  
Surface Active

An important role of the cell membrane in insulin degradation by cultured rat hepatocytes is supported by studies using the surface-active antibiotic bacitracin. Bacitracin inhibited degradation of cell-associated insulin (both randomly and A14 labeled) by 80–90% at 15 degrees C and by 60% at 37 degrees C. At 37 degrees C, inhibition of degradation was observed only with bacitracin present during dissociation and was accompanied by a compensatory increase in release of trichloroacetic acid (TCA)-precipitable insulin. This profile suggests inhibition of insulin degradation on the membrane after either primary binding or diacytosis (endocytosis-reverse endocytosis). In contrast, at 15 degrees C, bacitracin's inhibitory effect was greater with the antibiotic present during association and was not accompanied by a compensatory increase in TCA-precipitable insulin. This profile was compatible with inhibition of partial cleavage of insulin on the membrane. Internalization and degradation through chloroquine-sensitive pathways may be required to complete degradation at this temperature because chloroquine exhibited an inhibitory effect on insulin degradation equally potent to that of bacitracin at 15 degrees C (no effect at 37 degrees C).

scholarly journals Emerging role of chemoprotective agents in the dynamic shaping of plasma membrane organization

2017 ◽  
Vol 1859 (9) ◽  
pp. 1668-1678 ◽  
Author(s):  
Natividad R. Fuentes ◽  
Michael L. Salinas ◽  
Eunjoo Kim ◽  
Robert S. Chapkin
Keyword(s):  
Plasma Membrane ◽  
Membrane Organization

scholarly journals Caveolin-1 directly interacts with UT-A1 urea transporter: the role of caveolae/lipid rafts in UT-A1 regulation at the cell membrane

2009 ◽  
Vol 296 (6) ◽  
pp. F1514-F1520 ◽  
Author(s):  
Xiuyan Feng ◽  
Haidong Huang ◽  
Yuan Yang ◽  
Otto Fröhlich ◽  
Janet D. Klein ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Lipid Rafts ◽  
Hek293 Cells ◽  
Cell Fractionation ◽  
Urea Transporter ◽  
Cell Plasma Membrane ◽  
Caveolin 1 ◽  
Cell Plasma

The cell plasma membrane contains specialized microdomains called lipid rafts which contain high amounts of sphingolipids and cholesterol. Lipid rafts are involved in a number of membrane protein functions. The urea transporter UT-A1, located in the kidney inner medullary collecting duct (IMCD), is important for urine concentrating ability. In this study, we investigated the possible role of lipid rafts in UT-A1 membrane regulation. Using sucrose gradient cell fractionation, we demonstrated that UT-A1 is concentrated in the caveolae-rich fraction both in stably expressing UT-A1 HEK293 cells and in freshly isolated kidney IMCD suspensions. In these gradients, UT-A1 at the cell plasma membrane is codistributed with caveolin-1, a major component of caveolae. The colocalization of UT-A1 in lipid rafts/caveolae was further confirmed in isolated caveolae from UT-A1-HEK293 cells. The direct association of UT-A1 and caveolin-1 was identified by immunoprecipitation and GST pull-down assay. Examination of internalized UT-A1 in pEGFP-UT-A1 transfected HEK293 cells fluorescent overlap with labeled cholera toxin subunit B, a marker of the caveolae-mediated endocytosis pathway. Disruption of lipid rafts by methyl-β-cyclodextrin or knocking down caveolin-1 by small-interference RNA resulted in UT-A1 cell membrane accumulation. Functionally, overexpression of caveolin-1 in oocytes decreased UT-A1 urea transport activity and UT-A1 cell surface expression. Our results indicate that lipid rafts/caveolae participate in UT-A1 membrane regulation and this effect is mediated via a direct interaction of caveolin-1 with UT-A1.

scholarly journals Nutrient transporter translocation to the plasma membrane via a Golgi-independent unconventional route

2019 ◽  
Author(s):  
Vangelis Bouris ◽  
Olga Martzoukou ◽  
Sotiris Amillis ◽  
George Diallinas
Keyword(s):  
Plasma Membrane ◽  
Cell Membrane ◽  
Aspergillus Nidulans ◽  
Heavy Chain ◽  
Vesicular Trafficking ◽  
Rab Gtpases ◽  
Actin Network ◽  
Trafficking Pathway ◽  
Nutrient Transporter

AbstractNutrient transporters are believed to traffic from their site of synthesis, the ER, to the plasma membrane, through the Golgi, using the conventional vesicular trafficking pathway. However, here we report that the UapA purine transporter in Aspergillus nidulans, follows a Golgi-independent, unconventional new route, which does not involve key Rab GTPases, AP adaptors, microtubules or endosomes, but is dependent on functional COPII, clathrin heavy chain (ClaH) and actin. The role of ClaH in transporter secretion is shown to be unrelated to that performing, together with Rab11/AP-1, at the Golgi, and is seemingly due to an effect in actin network functioning. Our findings are discussed within the frame of a model that rationalizes why the trafficking mechanism uncovered herein might hold true for transporters in higher organisms.One Sentence SummaryFungal transporters use a non-polar, COPII- and actin-dependent, route for subcellular traffic to the cell membrane.

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

Role of Exosomes in the Exchange of Spermatozoa after Leaving the Seminiferous Tubule: A Review

2020 ◽  
Vol 21 (5) ◽  
pp. 330-338
Author(s):  
Luming Wu ◽  
Yuan Ding ◽  
Shiqiang Han ◽  
Yiqing Wang
Keyword(s):  
Drug Delivery ◽  
Plasma Membrane ◽  
Seminiferous Tubule ◽  
Metabolic Diseases ◽  
Inflammatory Diseases ◽  
Multivesicular Bodies ◽  
Extensive Search ◽  
Neurological Research ◽  
The One

Background: Exosomes are extracellular vesicles (EVs) released from cells upon fusion of an intermediate endocytic compartment with the plasma membrane. They refer to the intraluminal vesicles released from the fusion of multivesicular bodies with the plasma membrane. The contents and number of exosomes are related to diseases such as metabolic diseases, cancer and inflammatory diseases. Exosomes have been used in neurological research as a drug delivery tool and also as biomarkers for diseases. Recently, exosomes were observed in the seminal plasma of the one who is asthenozoospermia, which can affect sperm motility and capacitation. Objective: The main objective of this review is to deeply discuss the role of exosomes in spermatozoa after leaving the seminiferous tubule. Methods: We conducted an extensive search of the literature available on relationships between exosomes and exosomes in spermatozoa on the bibliographic database. Conclusion: : This review thoroughly discussed the role that exosomes play in the exchange of spermatozoa after leaving the seminiferous tubule and its potential as a drug delivery tool and biomarkers for diseases as well.

Sign in / Sign up

Export Citation Format

Share Document