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Monitoring ER/SR Calcium Release with the Targeted Ca2+ Sensor CatchER+
Published on: May 19, 2017
Extracellular Ca(2+) sensing in salivary ductal cells
Bidhan C Bandyopadhyay1, William D Swaim, Ankana Sarkar
1Calcium Signaling Laboratory, Research Service, Veterans Affairs Medical Center, Washington, DC 20422, USA. bidhan.bandyopadhyay@va.gov
The calcium-sensing receptor (CSR) regulates calcium reabsorption in salivary ducts via TRPC3 channels. This mechanism helps maintain salivary calcium levels, potentially preventing stones and infections.
Area of Science:
- Physiology
- Molecular Biology
- Cell Biology
Background:
- Salivary glands secrete calcium, but ductal reabsorption mechanisms remain unclear.
- Salivary calcium concentration decreases as it flows through ducts.
Purpose of the Study:
- Investigate the role of the calcium-sensing receptor (CSR) in regulating calcium reabsorption in salivary ducts.
- Identify the molecular mechanisms involved in salivary calcium homeostasis.
Main Methods:
- Immunohistochemistry to localize CSR and TRPC3 in salivary ducts.
- Experiments using isolated salivary ducts and a salivary ductal cell line (SMIE).
- Stimulation of CSR with extracellular calcium, L-phenylalanine, and neomycin.
Main Results:
- CSR is localized in the apical region of salivary ductal cells, co-localized with TRPC3.
- CSR activation by various stimuli triggers calcium influx via TRPC3.
- CSR stimulation enhances CSR-TRPC3 association and TRPC3 surface expression.
Conclusions:
- CSR acts as a luminal calcium sensor in salivary ducts, regulating calcium reabsorption through TRPC3.
- This CSR-TRPC3 pathway is crucial for maintaining salivary calcium levels.
- CSR may play a protective role against salivary gland stones (sialolithiasis) and infections (sialoadenitis).
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