FIG. 1.

(A–C) A schematic illustration of osteogenic, adipocytic, and neuronal differentiation pathways in mesenchymal stem cells. Akt, protein kinase B; BDNF, brain-derived neurotrophic factor; BMP, bone matrix protein; Ca²⁺, calcium ions; CEBP, enhancer binding protein; CREB, cAMP response element-binding protein; EGF, epithelial growth factor; ERK, extracellular signal-regulated kinases; FGF, fibroblast growth factor; GDNF, glial cell line-derived neurotrophic factor; GR, glucocorticoid receptor; HES, hairy and enhancer of split-1; IGF, insulin-like growth factor; Jnk, c-Jun N-terminal kinases; MAPK, mitogen-activated protein kinase; PI3K, phosphoinositide 3-kinase; PPAR, peroxisome proliferator-activated receptor; Runx2, runt-related transcription factor 2; TGFβ, transforming growth factor beta; TNF-α, tumour necrosis factor-alpha; Wnt, wingless/integrated. Color images are available online.