Related Experiment Videos
C2-Ceramide increases cytoplasmic calcium concentrations in human parathyroid cells
1Department of Surgery, Bristol Royal Infirmary, Bristol, BS2 8HW, United Kingdom.
Biochemical and Biophysical Research Communications
|February 19, 2000
Summary
Synthetic ceramides, like C2-ceramide, directly increase intracellular calcium in human parathyroid cells by releasing calcium from internal stores. This suggests ceramides may influence parathyroid cell function and calcium-sensing receptor responses.
Area of Science:
- Endocrinology
- Cell Biology
- Calcium Signaling
Background:
- Extracellular calcium ([Ca(2+)](ext)) regulates parathyroid cells via the calcium-sensing receptor (CaR).
- High extracellular calcium activates the sphingomyelin pathway, producing ceramides in bovine parathyroid cells.
Purpose of the Study:
- To investigate the direct effects of synthetic ceramides on intracellular calcium ([Ca(2+)](i)) in human parathyroid cells.
- To determine if ceramides modulate responses to calcium and CaR agonists.
Main Methods:
- Human parathyroid adenoma cells were cultured.
- Intracellular calcium was measured using Fura-2/AM fluorescence microscopy.
- Ceramide localization was assessed using a fluorescent ceramide analogue (BODIPY-C5) and laser scanning microscopy.
Main Results:
- C2-ceramide rapidly increased [Ca(2+)](i) in 70% of cells, indicating release from intracellular stores.
- C2-ceramide reduced subsequent responses to the CaR agonist neomycin.
- C6-ceramide did not affect basal [Ca(2+)](i) or responses to extracellular calcium or neomycin.
- BODIPY-C5 localized to the Golgi apparatus, suggesting ceramide targeting.
Conclusions:
- Synthetic ceramides directly impact intracellular calcium levels in human parathyroid cells.
- Ceramides may modulate parathyroid cell function and secretion in response to extracellular calcium levels.