Abstract
The association between kidney stone disease and renal fibrosis has been widely explored in recent years but its underlying mechanisms remain far from complete understanding. Using label-free quantitative proteomics (nanoLC-ESI-LTQ-Orbitrap MS/MS), this study identified 23 significantly altered secreted proteins from calcium oxalate monohydrate (COM)-exposed macrophages (COM-MP) compared with control macrophages (Ctrl-MP) secretome. Functional annotation and protein-protein interactions network analysis revealed that these altered secreted proteins were involved mainly in inflammatory response and fibroblast activation. BHK-21 renal fibroblasts treated with COM-MP secretome had more spindle-shaped morphology with greater spindle index. Immunofluorescence study and gelatin zymography revealed increased levels of fibroblast activation markers (α-smooth muscle actin and F-actin) and fibrotic factors (fibronectin and matrix metalloproteinase-9 and -2) in the COM-MP secretome-treated fibroblasts. Our findings indicate that proteins secreted from macrophages exposed to COM crystals induce renal fibroblast activation and may play important roles in renal fibrogenesis in kidney stone disease.