Sources for anti-inflammatory annexin A1 signals during acute anti-Thy-1.1 nephritis

Leukocyte infiltration presents a hallmark feature of immune-mediated acute kidney injury and defective resolution of inflammation may promote progression towards chronic kidney failure. Leukocytes exert distinctive effects during this process and may either aggravate kidney damage or foster renal repair. The glucocorticoid-inducible protein Annexin A1 has been shown to induce resolution of inflammation and to shift macrophage polarization towards the anti-inflammatory and repair-promoting M2 phenotype. The cellular source of the putative Annexin A1 signal and its regulation during the course of renal inflammation remains to be elucidated. Adult Wistar rats were injected with an antibody directed against the Thy-1.1 protein located on mesangial cells to induce mesangioproliferative glomerulonephritis. Animals were examined after 24h (initiation phase), 5d (proliferation phase), and 15d (resolution phase). Regulation of Annexin A1 was studied by qPCR and immunohistochemistry. Annexin A1+ cells were charact...