20(S)-Hydroxycholesterol

20(S)-Hydroxycholesterol (20α-Hydroxycholesterol) is an allosteric activator that selectively targets the Smoothened (Smo) of the Hedgehog pathway with an EC₅₀ of ~30 μM (Hedgehog). 20(S)-Hydroxycholesterol binds to the extracellular cysteine-rich domain (CRD) of Smo in a stereoselective manner, activating downstream Gli transcription factors (without inducing transcription of receptor genes in the Wnt pathway). 20(S)-Hydroxycholesterol enhances osteogenic differentiation of bone marrow stromal cells and synergistically activates the Raf/MEK/ERK pathway with Simvastatin (HY-17502) to promote bone regeneration. 20(S)-Hydroxycholesterol can be used to study the mechanisms of developmental biology, oncology, bone, and angiogenesis^[1][2][3]. IC50 & Target:EC50: 3 μM (hedgehog signaling pathway)^[1] In Vitro:20(S)-Hydroxycholesterol (20(S)-OHC) exists naturally as only one isomer, nat-20(S)-OHC. nat-20(S)-OHC (0.25 μM, 0.5 μM; overnight) effectively induces Hh reporter gene transcription in NIH 3T3 cells with EC₅₀ of 0.3 nM and 0.24 μM in the presence and absence of SAG (100 nM), respectively^[1].
nat-20(S)-OHC (8 μM; overnight) activates Hh signaling by directly inhibiting Ptc1, directly activating Smo, or regulating intermediate steps^[1].
20(S)-Hydroxycholesterol (5 μM; 3 d, 7 d) induces significantly higher proliferation activity in BMSCs and neutralized the inhibitory effect of Simvastatin (HY-17502) on cell viability^[2].
20(S)-Hydroxycholesterol (5 μM; 3 d, 7 d) combined with Simvastatin (0.25 μM), significantly increases ALP activity and calcium deposition in BMSCs^[2].
20(S)-Hydroxycholesterol (5 μM; 7 d, 14 d) combined with Simvastatin (0.25 μM), significantly increases ALP, OCN, and BMP-2 gene expressions, and significantly increases phosphorylated c-Raf, MEK, and ERK1/2 protein levels^[2].
In Vivo:20(S)-Hydroxycholesterol (1.0 μg/rabbit; topical application; single dose; 4 weeks) combined with Simvastatin (HY-17502), significantly promotes bone regeneration and induces abundant new bone and neovascularization in the defect area in the skull defect model of New Zealand white rabbits^[2].