ABSTRACT
BACKGROUND: Seed cells with good proliferation and enough amounts are need in reconstructing artificial salivary gland in vitro. However, adult stem cells are difficult to be isolated from normal submandibular gland.OBJECTIVE: To in vitro isolate submandibular gland stem/progenitor cells for cloning culture using animal models of damaged gland tissue.DESIGN, TIME AND SETTING: Cytological in vitro experiment was performed at the Gu.izhou Provincial Key Laboratory of Cell Tissue Engineering, Zunyi Medical College from March 2006 to January 2007.MATERIALS: A total of 10 male Sprague Dawley rats aged 8 weeks were supplied by the Animal Center, Third Military Medical University of Chinese PLA.METHODS: The model of tissue damaged submandibular gland in 10 rats was made by deligation. One week later, the gland tissue was obtained to harvest submandibular gland stem/progenitor cells by enzyme digestion in vitro. Following 10-14 days of primary culture, small round cells were collected, purified and subcultured for monoclonal culture.MAIN OUTCOME MEASURES: Immunocytochemical staining and immunofluorescence staining results were measured in submandibular gland stem/progenitor cells. Growth curve was drawn to analyze the proliferation of submandibular gland stem/progenitor cells in vitro.RESULTS: Cells expressing laminin showed stem cell characteristics. Positive expression of CD29 suggested high-adherent and high-proliferative stem cell properties. Positive expression of keratin-19 indicated epithelium-derived submandibular gland stem/progenitor cells. Growth curve was near to "S" shape, and in vitro culture and proliferation was active.CONCLUSION: Submandibular gland stem/progenitor cells had the characteristics of tissue stem cells. They might be as a kind of seed cells for tissue engineered artificial salivary gland in further research.