A crucial role for thiol antioxidants in estrogen-deficiency bone loss
J. Clin. Invest. Jenny M. Lean, et al. 112:915 doi:10.1172/JCI18859 [Go to this article.]

Figure 4
17-β estradiol modulates osteoclastic thiol antioxidant system, and osteoclasts are influenced by modulation of thiol antioxidant system. (a and b) 17-β estradiol stimulated glutathione reductase (GR) and thioredoxin reductase (TrxR) in osteoclasts. This stimulation was reversed by ICI 182,780 (ICI) (three cultures per variable). Statistically, significant stimulation of GR and TrxR by 17-β estradiol (E₂) and inhibition of stimulation by ICI 182,780 was observed in each of two further experiments. (c) BSO stimulated TRAP-positive multinucleate cell formation (TRAP-pos MNC), while this was suppressed by NAC. Like BSO, the ROS hydrogen peroxide also stimulated TRAP-positive multinucleate cell formation (10 cultures per variable). (d) EMSA was used to show effect of BSO and NAC on NF-κB activity in in vitro–formed osteoclasts. Activity (arrowheads) was increased by BSO and suppressed by NAC. We confirmed that the bound material contained NF-κB p50 by supershifting both bands with p50 Ab (arrow). The binding was further confirmed to be specific by competing binding of NF-κB with 100-fold excess of unlabeled self probe (S), but not by a mutant species (H). M, M-CSF; RL, RANKL. (e and f) 17-β estradiol and NAC suppress expression of RNA for TNF-α in in vitro-derived osteoclasts. *P < 0.05 versus other groups.