Acridine orange induces translocation of phosphatidylserine to red blood cell surface

Abstract

We studied acute changes of secretory vesicle pH in pancreatic beta-cells with a fluorescent pH indicator, lysosensor green DND-189. Fluorescence was decreased by 0.66 +/- 0.10% at 149 +/- 16 s with 22.2 mM glucose stimulation, indicating that vesicular pH was alkalinized by approximately 0.016 unit. Glucose-responsive pH increase was observed when cytosolic Ca2+ influx was blocked but disappeared when an inhibitor of glycolysis or mitochondrial ATP synthase was present. Glutamate dimethyl ester (GME), a plasma membrane-permeable analog of glutamate, potentiated glucose-stimulated insulin secretion at 5 mM without changing cellular ATP content or cytosolic Ca2+ concentration ([Ca2+]). Application of GME at basal glucose concentration decreased DND-189 fluorescence by 0.83 +/- 0.19% at 38 +/- 2 s. These results indicated that the acutely alkalinizing effect of glucose on beta-cell secretory vesicle pH was dependent on glucose metabolism but independent of modulations of cytosolic [Ca2+]. Moreover, glutamate derived from glucose may be one of the mediators of this alkalinizing effect of glucose, which may have potential relevance to the alteration of secretory function by glutamate.

Gold nanoparticle conjugated Rad6 inhibitor induces cell death in triple negative breast cancer cells by inducing mitochondrial dysfunction and PARP-1 hyperactivation: Synthesis and characterization

“…Control or SMI#9-GNP treated SUM1315 or HCC1937 cells were stained with LysoSensor Green DND-189 to label the lysosomes and the presence of aggregated GNP cargo examined. LysoSensor Green DND-189 is an acidotropic dye that accumulates in intracellular acidic organelles as a result of protonation and has a fluorescence intensity that is proportional to acidity (34, 35). SMI#9-GNP is efficiently internalized into SUM1315 cells as evidenced by the presence of GNP aggregates in lysosomes marked by the LysoSensor Green DND-189 dye (Fig.…”

“…LysoSensor Green DND-189 is an acidotropic dye that accumulates in intracellular acidic organelles as a result of protonation and has a fluorescence intensity that is proportional to acidity (34, 35). Ma et al (43) recently reported a GNP size-dependent alkalinization of lysosomes, which is consistent with the presence of large SMI#9-GNP aggregates and weak fluorescence of LysoSensor Green DND-189 dye in HCC1937 and MDA-MB-468 cells.…”

Dynamic Magnetic Fields Remote-Control ApoptosisviaNanoparticle Rotation

“…To confirm these findings, we next used the acidotropic probe (p K a = 5.2) LysoSensor Green DND 189. 26 The rationale for this experiment was that disruption of lysosomes would reduce the volume of the very acidic compartments in the cell and lead to a decrease in LysoSensor Green fluorescence (Figure 4C and 4D). Prior to DMF treatment, we found no difference in fluorescence intensity between SPION- and LAMP1-SPION-loaded cells.…”

Biocompatibility markers for the study of interactions between osteoblasts and composite biomaterials

“…During apoptosis, this asymmetry is disrupted and phosphatidylserine becomes exposed on the outside surface of the plasma membrane [13][14][15]. Since the anticoagulant protein annexin V binds with high affinity to phosphatidylserine, the allophycocyanin (APC) fluorochrome-conjugated annexin V has been used as a marker of the phosphatidylserine exposition on the outside surface of the plasma membrane as early signal of apoptosis [16]. Fig.…”