Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose:
Neurotransmitter stimulation of fluid secretion in salivary glands is regulated by increases in intracellular calcium concentration. The increase in cytosolic calcium triggers ion channel activities, leading to the secretion of fluid. The latter can be detected as a decrease in cell volume. Patients with primary Sjögren’s syndrome (pSS) display dry mouth conditions due to low salivary flow. We hypothesized that alterations in calcium signaling in acinar cells could account for the salivary gland dysfunction seen in pSS.
Methods:
The standard salivary gland cell preparation used for studying acinar function is obtained by enzymatic digestion of the gland. This procedure results in considerable loss of tissue and alterations in cellular integrity. Moreover, healthy cells could be selected in the digestion process. We have therefore developed a non-enzymatically dispersed tissue preparation in combination with confocal microscopy, to assess the functional status of minor salivary glands from Sjögren’s syndrome patients. We measured agonist-stimulated cytosolic calcium changes as well as cell volume changes by loading the salivary gland cluster-preparations with the calcium indicator, Fluo-2 AM, or cell-volume indicator, calcein. In addition we have examined the morphological characteristics of the glands.
Results:
Cell clusters showed well preserved acinar and ductal morphology and displayed dose-dependent response to stimulation by carbachol, both in terms of cytosolic calcium, where intracellular calcium increase and cell volume decreases. Cells from patients with poor flow displayed attenuation of agonist-stimulated cytosolic calcium and volume changes. Additionally, decreases in cell volume predicted salivary flow rates.
Conclusion:
We have developed a reproducible system to utilize non-enzymatically dispersed tissue preparations and examine with confocal microscopy the functional status of minor salivary glands. This system allows the exploration of mechanism(s) underlying the decrease in salivary gland function in each individual patient pertaining to the decrease in calcium mobilization. More specifically, this method will allow for the determination of whether the defect is at the level of intracellular calcium release or calcium entry and will also allow for the screening of therapeutic compounds in a personalized way. First, by identifying the secretory deficiencies of each individual pSS patient, and second testing which compounds might be more effective in treating salivary gland hypofunction.
Disclosure:
L. Y. Teos,
None;
B. Swaim,
None;
A. P. Cotrim,
None;
M. Grisius,
None;
L. Bebris,
None;
I. Ambudkar,
None;
G. G. Illei,
AstraZeneca,
1,
MedImmune,
3;
I. Alevizos,
None.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/hypofunction-in-intact-cell-lobules-reflect-salivary-flow-rates-in-sjogrens-patients/