Skin proteomic profiling of irradiation-induced fibrosis and its modulation by low molecular weight fucoidan via tight junction pathway

Fucoidans, sulfated and fucosylated polysaccharides extracted from brown seaweed, were found to inhibit radiotherapy-induced cell damage and fibrosis through the TGF-beta 1 pathway. However, the comprehensive molecular response during irradiation-induced fibrosis and fucoidan-assisted recovery still remain unclear. Rat hind limbs were irradiated and smeared with low molecular weight fucoidan (LMF). Protein profiles were examined by a mass spectrometry-based proteomics analysis. Out of a total of 4625 proteins, 233 were found to be significantly up-regulated after irradiation and down-regulated after LMF treatment. Pathway and proteinprotein interaction network analyses further indicated that four proteins including Actb, Ezr, Msn and Cdc42 were clustered into the tight junction and regulation of actin cytoskeleton pathways. These four proteins may serve as biomarkers for the detection of skin fibrosis induced by irradiation or TGF-beta 1, and for the recovery following LMF treatment.