Wnt/β-catenin signaling mediates the senescence of bone marrow-mesenchymal stem cells from systemic lupus erythematosus patients through the p53/p21 pathway

Recent studies have shown that allogeneic bone marrow (BM)-mesenchymal stem cell transplantation (MSCT) appears to be effective in systemic lupus erythematosus (SLE) patients and lupus-prone mice, contrary to studies in syngeneic BM-MSCT. These studies indicated that the abnormalities of BM-MSCs may be involved in the pathogenesis of SLE. Our studies and other previous studies have revealed that BM-MSCs from SLE patients exhibited early signs of senescence, such as flattened morphology, slow proliferation, increased senescence-associated beta-galactosidase (SA-beta-gal) activity, and so on. However, the mechanisms by which these cells senescences were still unclear. Previous studies have demonstrated that Wnt/beta-catenin signaling plays an important role in stem cell senescence. In the current study, we investigated whether Wnt/beta-catenin signaling mediates the senescence of BM-MSCs from SLE patients. We have found that Wnt/beta-catenin signaling and the p53/p21 pathway were significantly hyperactivated in senescent SLE BM-MSCs. Treatment with 100 ng/mL Dickkopf-1 (DKK1), a Wnt/beta-catenin signaling inhibitor or beta-catenin siRNA for 48 h could reverse the senescent features of SLE BM-MSCs. Additionally, the expression levels of p53 and p21 were reduced in treated-SLE BM-MSCs compared with the untreated group. In summary, our study indicated that Wnt/beta-catenin signaling may play a critical role in the senescence of SLE BM-MSCs through the p53/p21 pathway.