Using Time-Resolved Fluorescence Anisotropy of di-4-ANEPPDHQ and F2N12S to Analyze Lipid Packing Dynamics in Model Systems

Steele, Harmen B.; Sydor, Matthew J.; Anderson, Donald S.; Holian, Andrij; Ross, J. B. Alexander

doi:10.1007/s10895-019-02363-7

Cited by 8 publications

(8 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this work, di-4-ANEPPDHQ was selected as the fluorescence probe because it partitions into both the ordered and disordered phases of lipid membranes and exhibits phase-dependent fluorescence decay. This probe has been previously characterized by our laboratory and others in various model membrane systems or live cells and has been reported to be sensitive to changes in lipid membrane order resulting in shifts in emissions spectra and changes to fluorescence lifetime and anisotropy [34][35][36][37][38][39][40][41].…”

Section: Resultsmentioning

confidence: 99%

“…Fluorescence techniques have been employed previously to study the dynamic characteristics of lipid membranes such as lipid order, also described as fluidity, as seen in the review cited here [30]. In particular, solvatochromic fluorescence probes have been shown to report on the lipid order in membranes [31][32][33][34][35][36][37]. To better understand mechanisms of how ENM or silica disrupt membranes and cause permeability, timeresolved fluorescence lifetime imaging microscopy (FLIM) of RBC membranes was performed.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fluorescence lifetime imaging microscopy and time-resolved anisotropy of nanomaterial-induced changes to red blood cell membranes

Sydor¹,

Anderson²,

Steele³

et al. 2021

Methods Appl. Fluoresc.

Self Cite

View full text Add to dashboard Cite

With the use of engineered nano-materials (ENM) becoming more prevalent, it is essential to determine potential human health impacts. Specifically, the effects on biological lipid membranes will be important for determining molecular events that may contribute to both toxicity and suitable biomedical applications. To better understand the mechanisms of ENM-induced hemolysis and membrane permeability, fluorescence lifetime imaging microscopy (FLIM) was performed on human red blood cells (RBC) exposed to titanium dioxide ENM, zinc oxide ENM, or micron-sized crystalline silica. In the FLIM images, changes in the intensity-weighted fluorescence lifetime of the lipophilic fluorescence probe Di-4-ANEPPDHQ were used to identify localized changes to membrane. Time-resolved fluorescence anisotropy and FLIM of RBC treated with methyl-ß-cyclodextrin was performed to aid in interpreting how changes to membrane order influence changes in the fluorescence lifetime of the probe. Treatment of RBC with methyl-ß-cyclodextrin caused an increase in the wobble-in-a-cone angle and shorter fluorescence lifetimes of di-4-ANEPPDHQ. Treatment of RBC with titanium dioxide caused a significant increase in fluorescence lifetime compared to non-treated samples, indicating increased membrane order. Crystalline silica also increased the fluorescence lifetime compared to control levels. In contrast, zinc oxide decreased the fluorescence lifetime, representing decreased membrane order. However, treatment with soluble zinc sulfate resulted in no significant change in fluorescence lifetime, indicating that the decrease in order of the RBC membranes caused by zinc oxide ENM was not due to zinc ions formed during potential dissolution of the nanoparticles. These results give insight into mechanisms for how these three materials might disrupt RBC membranes and membranes of other cells. The results also provide evidence for a direct correlation between the size, interaction-available surface area of the nano-material and cell membrane disruption.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fluorescence lifetime imaging microscopy and time-resolved anisotropy of nanomaterial-induced changes to red blood cell membranes

Sydor¹,

Anderson²,

Steele³

et al. 2021

Methods Appl. Fluoresc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…DOPG liposomes in PBS were used to treat cells, while DOPC liposomes in TBS were incubated with silica particles at 37°C with tumbling for 2 h. Lipid order in 100-nm DOPC liposomes was assessed by time-resolved fluorescence anisotropy measurements of the lipophilic probe, Di-4-ANEPPDHQ. The fluorescence probe, Di-4-ANEPPDHQ has been previously demonstrated to be sensitive to changes in the lipid environment surrounding the probe ( Owen et al, 2011 ; Steele et al, 2019 ; Sydor et al, 2020 ; Sydor et al, 2021 ; Pavan et al, 2022 ). Di-4-ANEPPDHQ was dissolved in spectral grade dimethyl sulfoxide (DMSO) and used at a working concentration of 400 nM with the final DMSO concentration being <1%.…”

Section: Methodsmentioning

confidence: 99%

“…Di-4-ANEPPDHQ was dissolved in spectral grade dimethyl sulfoxide (DMSO) and used at a working concentration of 400 nM with the final DMSO concentration being <1%. Di-4-ANEPPDHQ was added 15 min before data collection and was allowed to incubate with the liposome sample at room temperature, as previously described ( Steele et al, 2019 ). An in-house built fluorimeter with parts from Quantum Northwest (Liberty Lake, WA) was used to acquire time-resolved anisotropy measurements as previously reported ( Minazzo et al, 2009 ).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Cholesterol content regulates silica-induced lysosomal membrane permeability

2023

Self Cite

View full text Add to dashboard Cite

Inhalation of crystalline silica has been well documented to cause pulmonary inflammation and lung disease such as silicosis. Respirable silica particles deposit in the lungs and are phagocytosed by alveolar macrophages. Subsequently, phagocytosed silica remains undegraded within lysosomes causing lysosomal damage known as phagolysosomal membrane permeability (LMP). LMP can trigger the assembly of the NLRP3 inflammasome resulting in release of inflammatory cytokines that contribute to disease. In order to better understand the mechanisms of LMP this study used murine bone marrow derived macrophages (BMdM) as a cellular model to investigate the mechanism of silica-induced LMP. Reduction of lysosomal cholesterol in bone marrow derived macrophages with 18:1 phosphatidylglycerol (DOPG) liposome treatment increased silica-induced LMP and IL-1β release. Conversely, increasing lysosomal and cellular cholesterol with U18666A reduced IL-1β release. Co-treatment of bone marrow derived macrophages with 18:1 phosphatidylglycerol and U18666A resulted in a significant reduction of the effects of U18666A on lysosomal cholesterol. Phosphatidylcholine 100-nm liposome model systems were used to examine the effects of silica particles on lipid membrane order. Time-resolved fluorescence anisotropy of the membrane probe, Di-4-ANEPPDHQ, was used to determine changes to membrane order. Silica increased lipid order that was attenuated by inclusion of cholesterol in the phosphatidylcholine liposomes. These results demonstrate that increased cholesterol can attenuate silica-induced membrane changes in liposomes and cell models, while decreasing cholesterol exacerbates silica-induced membrane changes. Selective manipulation of lysosomal cholesterol may be a way of attenuating lysosomal disruption and preventing silica-induced chronic inflammatory disease progression.

show abstract

Effects of titanium dioxide and zinc oxide nano-materials on lipid order in model membranes

Sydor

Anderson

Steele

et al. 2020

Biochimica et Biophysica Acta (BBA) - Biomembranes

View full text Add to dashboard Cite

Using Time-Resolved Fluorescence Anisotropy of di-4-ANEPPDHQ and F2N12S to Analyze Lipid Packing Dynamics in Model Systems

Cited by 8 publications

References 25 publications

Fluorescence lifetime imaging microscopy and time-resolved anisotropy of nanomaterial-induced changes to red blood cell membranes

Fluorescence lifetime imaging microscopy and time-resolved anisotropy of nanomaterial-induced changes to red blood cell membranes

Cholesterol content regulates silica-induced lysosomal membrane permeability

Effects of titanium dioxide and zinc oxide nano-materials on lipid order in model membranes

Contact Info

Product

Resources

About