Updated project metadata. During aging, senescent cells accumulate in bone marrow and secrete the dysfunctional factors, termed senescence associated secretory phenotype (SASP), which is implied to regulate bone metabolism. To identify the key SASP factors in bone marrow that influence skeletal aging, we analyzed the dysregulated factors in the bone marrow supernatant from young and aged rat through mass spectrometry. In another hand, BMSCs treated with rGCA, transfection of siRNA-Plxnb2 or controls were subjected to global quantitative phosphoproteomic analysis.