Paracrine stimulation effect of human salispheres on mouse salivary gland

Human salispheres, a culture of stem/progenitor cells, represent a potential therapy for radiation induced hyposalivation. Radiation-induced hyposalivation dramatically reduces quality of life of patients. We have demonstrated the potential of human salispheres to engraft and differentiate when transplanted into a mouse model of hyposalivation, in the manuscript associated with these data. We also demonstrate the functional recovery of irradiated salivary glands (SGs) following human salisphere transplantation, by the measurement of saliva production. When analyzing human salisphere- transplanted SGs for the presence of human cells, we noted that the highest proportion of human cells were present 1 week after transplantation. This microarray study was designed to determine if paracrine signaling from transplanted human salisphere cells to recipient mouse SGs accounts for a part of the functional recovery of the recipient SG we observe. We compare the transcriptome from irradiated control SG of immunecompromised NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice with that of NSG SGs transplanted with 100,000 human salisphere cells. All mice were sacrificed 1 week following transplantation (or non-transplantation in case of controls) and Illumina array chips used to detect differences in gene expression. 6 samples were analysed in total. Total RNA from 3 irradiated control SGs (5Gy irradiation) and 3 salivary glands transplanted with 100,000 human salispheres.