Related Experiment Video
Updated: Jun 5, 2026
13:04
Atomic Absorbance Spectroscopy to Measure Intracellular Zinc Pools in Mammalian Cells
Published on: May 16, 2019
LPS-induced decrease in intracellular labile zinc, [Zn]i, contributes to apoptosis in cultured sheep pulmonary artery
Kalidasan Thambiayya1, Karla J Wasserloos, Zhentai Huang
1Department of Bioengineering, University of Pittsburgh and Universityof Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA.
Summary
Lipopolysaccharide (LPS) triggers a delayed decrease in intracellular zinc ([Zn](i)) in pulmonary artery endothelial cells, contributing to apoptosis. Restoring zinc levels mitigates this cell death, revealing a novel signaling role for zinc in endothelial cell response to LPS.
Area of Science:
- Cellular Biology
- Signaling Pathways
- Zinc Homeostasis
Background:
- Intracellular labile zinc ([Zn](i)) is implicated in signal transduction, but its role in lipopolysaccharide (LPS)-induced apoptosis in pulmonary endothelium is unclear.
- Previous studies showed conflicting results regarding LPS effects on [Zn](i) and its association with cell death.
- Sheep pulmonary artery endothelial cells (SPAEC) are a relevant model for studying pulmonary responses to LPS.
Purpose of the Study:
- To investigate the dynamic changes in [Zn](i) in SPAEC following LPS stimulation.
- To determine the role of decreased [Zn](i) in LPS-induced apoptosis in SPAEC.
- To elucidate the signaling mechanism of zinc in pulmonary endothelial cell apoptosis.
Main Methods:
- Utilized chemical methods (FluoZin-3 fluorescence) and genetic reporters to measure [Zn](i) changes.
- Assessed apoptosis using caspase-3/7 activation, annexin-V binding, and cytochrome c release assays.
- Employed zinc chelator (TPEN) and exogenous zinc to modulate [Zn](i) levels and apoptosis.
Main Results:
- LPS induced a delayed, time-dependent decrease in [Zn](i) in SPAEC (2-4 hours).
- The zinc chelator TPEN mimicked LPS-induced apoptosis, while exogenous zinc inhibited it.
- Decreased [Zn](i) was directly linked to caspase activation, DNA fragmentation, and mitochondrial dysfunction.
Conclusions:
- This study provides the first evidence for a signaling role of decreased [Zn](i) in LPS-induced apoptosis in pulmonary endothelial cells.
- Endogenous labile zinc levels modulate the sensitivity of pulmonary endothelium to LPS-induced pro-apoptotic stimuli.
- Targeting zinc homeostasis may offer therapeutic strategies for inflammatory lung diseases.
