Development of gene expression signatures for ASC activated by LL-37

To further development of our gene expression approach to ASC-mediated regeneration, we have employed whole genome microarray expression profiling as a discovery platform to identify genes with the potential to distinguish radiation dose across an exposure range relevant for medical decision-making in a radiological emergency. Human peripheral blood from healthy donors was irradiated ex vivo, and a 74-gene consensus signature was identified that distinguished between four radiation doses (0.5, 2, 5 and 8 Gy) and control samples. The same set of genes separated samples by exposure level at both six and 24 hours after treatment, with overlap evident only at the highest two doses (5 and 8 Gy). Expression of five genes (CDKN1A, FDXR, SESN1, BBC3 and PHPT1) from this signature was quantified in the same RNA samples by real-time PCR, confirming low variability between donors as well as the predicted radiation response pattern. LL-37 induced gene expression in human ASCs was measured at 1 hours after exposure to doses of 0, 20 microgram/ml LL-37.