Characterization of tissue-specific stem cells from murine salivary gland

Objectives: Patients with Sjögren's syndrome or head and neck cancer patients with radiation therapy suffer from xerostomia due to salivary gland tissue damage. Current xerostomia therapies only provide temporary symptomatic treatment and no satisfactory treatment option has been established. However, stem cell-based regenerative therapy is a promising treatment for these patients. Here, to examine whether CD133+cells have stem cell-like property, CD133+cells were isolated from mouse salivary glands and also characterized.
Methods: We isolated tissue-specific stem cells from adult murine submandibular glands. Submandibular gland cells were stained with CD133-APC Lin-FITC and sorted using fluorescence-activated cell sorting. Futhermore, we characterized CD133+ cell and examined whether these cells have stem cell property.
Results: The analysis confirmed the presence of Lin-CD133+ cells. The percentages of Lin-CD133+ cells were 3.0%. In vitro, Lin-CD133+ cells show significantly higher colony formation and sphere formation abilities compared to Lin-CD133- cells, suggesting that CD133+ cells have progenitor or stem cell potency. Furthermore, Lin-CD133+ cells derived from transgenic mice expressing GFP were transplanted into the partially excised submandibular gland of wild type mice, and the reconstitution potential was examined. The Lin-CD133+GFP+cells transplanted in salivary gland differentiated into ductal and acinar cells. In addition, the differential gene expression patterns of the Lin-CD133+ and Lin-CD133+ cells were analyzed using RNA sequence. The analysis revealed that c-kit and Sox9 were highly expressed in Lin-CD133+ cells.
Conclusions: We identified and characterized CD133-positive cells in salivary glands , and these cells demonstrated progenitor/stem cell-like ability. In addition, we provided that these progenitor/stem cell-like property might be regulated by Sox9.