Fig. 2

Secretion of autocrine and paracrine cytokines is induced by the transplanted BMMSCs. These factors have diverse functions. For instance, IL-4 and IL-10 can suppress inflammatory role and exert positive effect. GM-CSF recruits peripheral monocytes into the lesion. These monocytes are further activated by extracellular Aβ proteins, which accelerate Aβ clearance in APP/PS1 mice. TGF-β participates in multiple signaling pathways to mediate amyloid metabolism, immunoregulation, and neuroprotection. The comprehensive effect of functional autocrine and paracrine cytokines determines the therapeutical potential of BMMSC