Salivary gland cell aggregates are derived from self-organization of acinar lineage cells.
Jomy J Varghese, M Eva Hansen, Azmeer Sharipol, Matthew H Ingalls, Martha A Ormanoski, Shawn D Newlands, Catherine E Ovitt, Danielle S W Benoit
Author Information
Jomy J Varghese: Department of Biomedical Engineering, University of Rochester, United States.
M Eva Hansen: Department of Biomedical Engineering, University of Rochester, United States.
Azmeer Sharipol: Department of Biomedical Engineering, University of Rochester, United States.
Matthew H Ingalls: Department of Biomedical Genetics, University of Rochester, United States.
Martha A Ormanoski: Department of Biomedical Engineering, Cornell University, United States.
Shawn D Newlands: Department of Otolaryngology, University of Rochester, United States; Wilmot Cancer Institute, University of Rochester, United States; Department of Neuroscience, University of Rochester, United States.
Catherine E Ovitt: Department of Biomedical Genetics, University of Rochester, United States; Center for Oral Biology, University of Rochester, United States. Electronic address: catherine_ovitt@urmc.rochester.edu.
Danielle S W Benoit: Department of Biomedical Engineering, University of Rochester, United States; Department of Biomedical Genetics, University of Rochester, United States; Center for Oral Biology, University of Rochester, United States; Center for Musculoskeletal Research, University of Rochester, United States; Department of Orthopaedics, University of Rochester, United States; Department of Chemical Engineering, University of Rochester, United States. Electronic address: benoit@bme.rochester.edu.
OBJECTIVE: The objective of this study was to characterize the mechanism by which salivary gland cells (SGC) aggregate in vitro. DESIGN: Timelapse microscopy was utilized to analyze the process of salivary gland aggregate formation using both primary murine and human salivary gland cells. The role of cell density, proliferation, extracellular calcium, and secretory acinar cells in aggregate formation was investigated. Finally, the ability of cells isolated from irradiated glands to form aggregates was also evaluated. RESULTS: Salivary gland cell self-organization rather than proliferation was the predominant mechanism of aggregate formation in both primary mouse and human salivary gland cultures. Aggregation was found to require extracellular calcium while acinar lineage cells account for ∼80% of the total aggregate cell population. Finally, aggregation was not impaired by irradiation. CONCLUSIONS: The data reveal that aggregation occurs as a result of heterogeneous salivary gland cell self-organization rather than from stem cell proliferation and differentiation, contradicting previous dogma. These results suggest a re-evaluation of aggregate formation as a criterion defining salivary gland stem cells.
