Murine embryonic mesenchymal stem cells attenuated xerostomia in Sjögren-like mice via improving salivary gland epithelial cell structure and secretory function.

BACKGROUND Xerostomia is the main manifestation from patients with Sjogren syndrome (SS). However, traditional immunosuppressive agents are nearly invalid due to complicated etiopathogenesis in salivary glands, including aberrant immune dysregulation, epithelial structure destruction, and diminished secretory function. OBJECTIVE To investigate the therapeutic effect of murine embryonic mesenchymal stem cells (ME-MSCs) on salivary glandular epithelium structure and secretory function in Sjogren-like mice. METHODS Salivary flow rate (SFR), blood glucose, and body weight was weekly monitored among treatment group, disease group, and health control group. ME-MSCs were used to treat NOD mice via tail vein injection. HE staining and transmission electron microscope was used to evaluate the structure of salivary gland epithelial cells (SGEC). TUNEL fluorescence staining and PCNA immumohistochemical staining was used to evaluate the SGEC apoptosis and proliferation. The SGEC secretory function was tested by PAS staining and amylase immumohistochemical staining. RESULTS ME-MSC treatment could elevate SFR, restore the acini and micromorphologies, promote the SGEC proliferation, and suppress the SGEC apoptosis in NOD mice, but not restore to that in health control group. The SGEC structure was more intact in treatment group. Mucopolysaccharide and amylase of salivary acinar cells in treatment group was better than that in disease group, although transmission electron microscopy showed secretory granules were lower than those in healthy control. CONCLUSION ME-MSCs demonstrated its potential as a candidate treatment for xerostomia due to some effects on salivary flow rate in NOD mice by restoring the SGEC impairment and secretory function.