Figure 6: Succinate-enhanced osteoclastogenesis via NF-κB activation is counteracted by metformin.

(a) Representative TRAP staining images (scale bar, 250 μm) and (b) analysis of OC cell culture on day 6 derived from WT and MKR mouse bone marrow cells. PBS or metformin (200 mg kg⁻¹) were administrated daily to the mice for 14 days before bone marrow cells were harvested for OC cultures; succinate: 1 mM succinate was added in OC cell cultures; data show mean±s.e.m. of triplicated wells; *P<0.05, **P<0.01 according to a two-tailed t-test post ANOVA, n=4. (c) Western blotting of OCs culture derived 12-week-old MKR mice. Suc: 1 mM, Met: 500 μM. Levels of p50 and p65 of nuclear proteins from bone marrow OC cells. (d) Indirect IF of P65, P50 and DAPI (4′,6-diamidino-2-phenylindole) in OCs derived from WT and SUCNR1 KO mouse bone marrow cells stimulated with 30 ng ml⁻¹ MCSF and 30 ng ml⁻¹ RANKL on day 5.