scholarly journals Detection of apoptosis through the lipid order of the outer plasma membrane leaflet

2012 ◽  
Vol 1818 (12) ◽  
pp. 3048-3054 ◽  
Author(s):  
Zeinab Darwich ◽  
Andrey S. Klymchenko ◽  
Oleksandr A. Kucherak ◽  
Ludovic Richert ◽  
Yves Mély
Keyword(s):  
Plasma Membrane ◽  
Lipid Order ◽  
Outer Plasma Membrane

scholarly journals Caspase-3 activation decreases lipid order in the outer plasma membrane leaflet during apoptosis: A fluorescent probe study

2017 ◽  
Vol 1859 (10) ◽  
pp. 2123-2132 ◽  
Author(s):  
Kyrylo A. Pyrshev ◽  
Semen O. Yesylevskyy ◽  
Yves Mély ◽  
Alexander P. Demchenko ◽  
Andrey S. Klymchenko
Keyword(s):  
Plasma Membrane ◽  
Fluorescent Probe ◽  
Caspase 3 ◽  
Lipid Order ◽  
Outer Plasma Membrane

An Ultrastructural Study of Pericytes

1968 ◽  
Vol 26 ◽  
pp. 66-67
Author(s):  
T. M. Murad ◽  
E. von Haam
Keyword(s):  
Plasma Membrane ◽  
Endothelial Cell ◽  
Basement Membrane ◽  
Blood Vessel ◽  
Vascular Endothelial Cells ◽  
Myoepithelial Cells ◽  
Capillary Blood ◽  
The Body ◽  
Capillary Blood Vessel ◽  
Outer Plasma Membrane

Pericytes are vascular satellites present around capillary blood vessels and small venules. They have been observed in almost every tissue of the body and are thought to be related to vascular smooth muscle cells. Morphologically pericytes have great similarity to vascular endothelial cells and also slightly resemble myoepithelial cells.The present study describes the ultrastructural morphology of pericytes in normal breast tissue and in benign tumor of the breast. The study showed that pericytes are ovoid or elongated cells separated from the endothelial cell of the capillary blood vessel by the basement membrane of endothelial cell. The nuclei of pericytes are often very distinctive. Although some are round, oval, or elongated, others show marked irregularity and infolding of the nuclear membrane. The cytoplasm shows mono-or bipolar extension in which the cytoplasmic organelles are located (Fig. 1). These cytoplasmic extensions embrace the capillary blood vessel incompletely. The plasma membrane exhibits multiple areas of focal condensation called hemidesmosomes (Fig. 2, arrow). A variable number of pinocytotic vesicles are frequently seen lining the outer plasma membrane. Normally pericytes are surrounded by a basement membrane which is found more consistently on the outer plasma membrane separating the pericytes from the stromal connective tissue.

scholarly journals Visualization of β-adrenergic receptor dynamics and differential localization in cardiomyocytes

2021 ◽  
Vol 118 (23) ◽  
pp. e2101119118
Author(s):  
Marc Bathe-Peters ◽  
Philipp Gmach ◽  
Horst-Holger Boltz ◽  
Jürgen Einsiedel ◽  
Michael Gotthardt ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Cell Surface ◽  
Adrenergic Receptor ◽  
Cardiac Contractility ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Receptor Subtypes ◽  
Specific Cell ◽  
Adult Cardiomyocytes ◽  
Outer Plasma Membrane

A key question in receptor signaling is how specificity is realized, particularly when different receptors trigger the same biochemical pathway(s). A notable case is the two β‐adrenergic receptor (β‐AR) subtypes, β1 and β2, in cardiomyocytes. They are both coupled to stimulatory Gs proteins, mediate an increase in cyclic adenosine monophosphate (cAMP), and stimulate cardiac contractility; however, other effects, such as changes in gene transcription leading to cardiac hypertrophy, are prominent only for β1‐AR but not for β2-AR. Here, we employ highly sensitive fluorescence spectroscopy approaches, in combination with a fluorescent β‐AR antagonist, to determine the presence and dynamics of the endogenous receptors on the outer plasma membrane as well as on the T-tubular network of intact adult cardiomyocytes. These techniques allow us to visualize that the β2‐AR is confined to and diffuses within the T-tubular network, as opposed to the β1‐AR, which is found to diffuse both on the outer plasma membrane as well as on the T-tubules. Upon overexpression of the β2‐AR, this compartmentalization is lost, and the receptors are also seen on the cell surface. Such receptor segregation depends on the development of the T-tubular network in adult cardiomyocytes since both the cardiomyoblast cell line H9c2 and the cardiomyocyte-differentiated human-induced pluripotent stem cells express the β2‐AR on the outer plasma membrane. These data support the notion that specific cell surface targeting of receptor subtypes can be the basis for distinct signaling and functional effects.

scholarly journals Sponging of glutamate at the outer plasma membrane surface reveals roles for glutamate in development

2021 ◽  
Author(s):  
Vanessa Castro‐Rodríguez ◽  
Thomas J. Kleist ◽  
Nicoline M. Gappel ◽  
Fatiha Atanjaoui ◽  
Sakiko Okumoto ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Surface ◽  
Outer Plasma Membrane ◽  
Plasma Membrane Surface

326 COMPARING CHANGES IN MEMBRANE LIPID ORDER IN EPIDIDYMAL AND EJACULATED BOAR SPERMATOZOA

2007 ◽  
Vol 19 (1) ◽  
pp. 277
Author(s):  
C. Matas ◽  
F. Garcia-Vazquez, ◽  
M. Sansegundo ◽  
S. Ruiz ◽  
J. Gadea
Keyword(s):  
Plasma Membrane ◽  
Seminal Plasma ◽  
Lipid Membrane ◽  
Calcium Influx ◽  
Membrane Lipid ◽  
Treatment Groups ◽  
Lipid Disorder ◽  
Lipid Order ◽  
Merocyanine 540 ◽  
Boar Spermatozoa

The diffusion of lipids in the plasma membrane of ejaculated spermatozoa is influenced by seminal plasma proteins and the composition of the suspending medium (Wolfe et al. 2001 Mol. Reprod. Dev. 59, 306–313). Merocyanine 540 (M540) is a hydrophobic dye that has been shown to stain cell membranes more intensely if their lipid components are in a higher state of disorder, as is the case of capacitated spermatozoa. It is believed that the membrane fluidity changes detected by M540 precede the calcium influx, making M540 a method for evaluating the early events of capacitation. The aim of this study was to determine if there are differences in the dynamics of lipid disorder in the plasma membrane of ejaculated and epididymal boar spermatozoa under different conditions of capacitation. The sperm capacitation treatments were: washed in Delbucco's PBS supplemented with 0.1 % BSA (PBS-BSA), washed on a Percoll gradient (PG), and unwashed (UW: Control). During measurement, the samples were kept at 38�C and 5 % CO2 to maintain constant incubation conditions. Membrane lipid order and sperm viability were determined by flow cytometry with M540 (2.7 �M) and Yo-Pro-1 (25 nM), respectively. Samples were analyzed on a Coulter Epics XL flow cytometer (Beckman Coulter Co., Inc., Fullerton, CA, USA). A total of 10 000 gated events were collected per sample, with sample running rates of approximately 600 events/s. Data were analyzed by analysis of variance (ANOVA). For the epidydimal vs. ejaculated results, the percentage of low lipid disorder spermatozoa was higher in the epididymal (19.23%) than in the ejaculated (5.84%) groups, and the proportion of high disorder (42.85%) and dead cells (48.59%) was higher in the ejaculated group. In relation to sperm treatment (UW, PBS-BSA, and PG), the percentage of high disorder was similar in all of the treatment groups (UW: 44.62 %; PBS-BSA: 43.08%; PG: 43.41%). Finally, the percentage of low disorder was lower in the PBS-BSA and PERCOLL (10.68% and 12.83%, respectively) groups, and the highest was obtained for the UW group (14.09%). In conclusion, the staining with M540 revealed that the lipid disorder was affected by the source of the sperm and the sperm treatment. A significant increase in membrane lipid low disorder and decrease in high disorder and dead cells were detected when epididymal sperm were compared with ejaculated sperm, so the seminal plasma and the sperm treatment to eliminate disorder have an important effect in the lipid membrane order. Supported by MEC (AGL2006-03495/GAN) and Fundaci�n S�neca (03018/PI/05).

scholarly journals Lipid order and charge protect killer T cells from accidental death

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jesse A. Rudd-Schmidt ◽  
Adrian W. Hodel ◽  
Tahereh Noori ◽  
Jamie A. Lopez ◽  
Hyun-Jung Cho ◽  
...  
Keyword(s):  
T Cells ◽  
Plasma Membrane ◽  
Target Cell ◽  
Serine Proteases ◽  
Immunological Synapse ◽  
Synaptic Cleft ◽  
Target Cells ◽  
Lipid Order ◽  
Target Cell Membrane ◽  
Killer T Cells

AbstractKiller T cells (cytotoxic T lymphocytes, CTLs) maintain immune homoeostasis by eliminating virus-infected and cancerous cells. CTLs achieve this by forming an immunological synapse with their targets and secreting a pore-forming protein (perforin) and pro-apoptotic serine proteases (granzymes) into the synaptic cleft. Although the CTL and the target cell are both exposed to perforin within the synapse, only the target cell membrane is disrupted, while the CTL is invariably spared. How CTLs escape unscathed remains a mystery. Here, we report that CTLs achieve this via two protective properties of their plasma membrane within the synapse: high lipid order repels perforin and, in addition, exposed phosphatidylserine sequesters and inactivates perforin. The resulting resistance of CTLs to perforin explains their ability to kill target cells in rapid succession and to survive these encounters. Furthermore, these mechanisms imply an unsuspected role for plasma membrane organization in protecting cells from immune attack.

ADH modulates plasma membrane lipid order of living MDCK cells via a cAMP-dependent process

1990 ◽  
Vol 259 (1) ◽  
pp. F95-F103
Author(s):  
M. C. Giocondi ◽  
G. Friedlander ◽  
C. Le Grimellec
Keyword(s):  
Plasma Membrane ◽  
Mdck Cells ◽  
Membrane Lipid ◽  
Target Cells ◽  
Similar Response ◽  
Solute Permeability ◽  
Lipid Order ◽  
Plasma Membrane Lipid ◽  
Darby Canine Kidney

Using 1-[4-(trimethylamino)phenyl]-6-phenyl-hexa-1,3,5-triene, a fluorescent probe that specifically labels the external leaflet of the plasma membrane of living cells, we examined the effects of antidiuretic hormone (ADH) and various agents known to raise intracellular adenosine 3',5'-cyclic monophosphate (cAMP) on the physical state of the plasma membrane of Madin-Darby canine kidney (MDCK) cells. In polarized cells grown as a monolayer, [desamino-Cys1, DArg8]-vasopressin (V2-agonist) elicited a biphasic decrease in the lipid order as estimated from the decrease in fluorescence anisotropy (from r = 0.317 to r = 0.304, 37 degrees C) of the apical domain of the plasma membrane, equivalent at the peak response (t = 5 min) to that produced by an upward shift in temperature of 5-6 degrees C. A similar response was obtained by adding dibutyryl cAMP to the monolayers. Experiments on cell suspensions further indicated that the biphasic decrease in lipid order could also be evoked by forskolin, prostaglandin E2, and bradykinin but not by bradykinin plus indomethacin and was inhibitable by the protein kinases inhibitor compound H7. These data demonstrate that the lipid order of the plasma membrane of MDCK cells can be modulated in situ by cAMP-dependent processes probably involving protein kinase A activity, i.e., that membrane “fluidity” might act in the regulation of the cellular function of living epithelial cells. They provide a rationale for the changes in lipophilic solute permeability that accompany the increase in water permeability of target cells on ADH administration.

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