Fig. 4

The NRF2-CD36 signaling axis controls myelin internalization by phagocytes. a Experimental setup of phagocytosis (top) and Oil Red O (ORO, bottom) experiments. b Internalization of DiI-labeled myelin by control and myelin pre-treated bone marrow-derived macrophages (BMDMs, n = 6 wells) and microglia (n = 4 wells). The CD36 inhibitor sulfo-N-succinimidyl oleate (SSO, 100 μM) was used to block CD36 activity. The internalization of DiI-labeled myelin was defined via flow cytometry and data are depicted as mean fluorescence intensity (MFI). c, d Representative images and quantification of ORO staining of control and myelin pre-treated BMDMs (n = 20 cells) and microglia (n = 50 cells) exposed to SSO (100 μM) or vehicle and myelin. ORO load is defined as the percentage of cellular area that is ORO⁺. Scale bar, 20 μm. e Internalization of DiI-labeled myelin by wild-type (wt) and Nrf2^−/− control and myelin pre-treated BMDMs (n = 4 wells). f, g Representative images and quantification of ORO staining of control and myelin pre-treated wt and Nrf2^−/− BMDMs exposed to myelin (n = 20 cells). Scale bar, 20 μm. h Internalization of DiI-labeled myelin by myelin pre-treated wt and Nrf2^−/− BMDMs, which were exposed to SSO (100 μM) or vehicle (n = 4 wells). AU, arbitrary units. Data are represented as mean ± s.e.m. *p < 0.05 and **p < 0.01