Research Paper Volume 11, Issue 21 pp 9626—9642

Cellular senescence induced by S100A9 in mesenchymal stromal cells through NLRP3 inflammasome activation

Figure 1. S100A9 induces cellular senescence in bone marrow stromal cells. (A) S100A9 expression in BM-MNCs isolated from MDS patient specimens (n = 19 LR-MDS, and n = 13 HR-MDS) compared with the expression in normal control BM-MNCs (n =20) as determined with qPCR (left). S100A9 levels in bone marrow supernatant from MDS patient specimens (n = 16 LR-MDS, and n = 8 HR-MDS) compared with the levels in normal BM-MNCs (n =10) as measured with ELISA (right). (B) HS-27a cells and MSCs were co-cultured with normal control BM-MNCs and MDS BM-MNCs. Senescent cells (green) were tested after 72 h. The number of senescent cells from at least 500 cells in 10 randomly chosen fields was used to calculate their percentage (40 × magnification). (C) Cells were treated with rhS100A9 (200 ng/ml for HS-27a, 500 ng/ml for MSC) for 72h. Subsequently, senescent cells were counted and presented in graphs (40 × magnification). Finally, p53, p21, and p16 levels were measured using qPCR and western blot. Data are expressed as mean ± SD from three experiments. *P<0.05, **P<0.01, and ***P<0.001.