JAK-STAT signaling mediates the senescence of bone marrow-mesenchymal stem cells from systemic lupus erythematosus patients

Previous studies have revealed that bone marrow-mesenchymal stem cells (BM-MSCs) fromsystemic lupus erythematosus (SLE) patients exhibited early signs of senescence, which may participate in the development of SLE. However, the molecular mechanisms about this phenomenon have not been fully elucidated. In the current study, we aimed to investigate whether Janus kinase (JAK)-signaling transducers and activators of transcription (STAT) signaling mediated the senescence of BM-MSCs from SLE patients. Twelve female SLE patients and healthy subjects were enrolled in the study. All BM-MSCs were isolated by density gradient centrifugation. Western blot analysis was used to test the expression of JAK-STAT signaling molecules. We observed the activity of beta-gal of cells, the changes of cytoskeletal structure by F-actin staining, and the distribution of cell cycle by flow cytometry. BM-MSCs from SLE patients showed prominent features of senescence, and abnormal activation of JAK-STAT signaling transduction, high level of phosphorylated JAK2, and STAT3. After stimulation of IFN-gamma in normal MSCs, JAK-STAT signaling was activated. The cell volume and the number of senescence-associated beta-galactosidase (SA-beta-gal) positive in SLE BM-MSCs were increased. The organization of cytoskeleton was nearly disordered. The rate of cell proliferation was decreased. AG490, the inhibitor of JAK2, and knockdown of STAT3 in BM-MSCs, could significantly reverse the senescence. In summary, our study indicated that JAK-STAT signaling pathway may play a critical role in the senescence of SLE BM-MSCs.