Supplementary Figure 2: Complex II is hyper-functional in PPBL B cells
From: SDHA gain-of-function engages inflammatory mitochondrial retrograde signaling via KEAP1–Nrf2
(a) Representative transmission electron microscopy images of a primary B cell from a HC and a PPBL patient (left). White scale bar, 2000 nm. Black scale bar, 1000 nm. Summary graphs of cell area; mitochondrial area; mitochondria count per cell, and mitochondrial aspect ratio (length/width) from HCs (n = 3) and PPBL patients (n = 3) (right). 45 B cells were analyzed per individual in 3 independent experiments. (b) Representative immunoblot analysis of primary B cells from a HC and a PPBL patient. Blots were probed for Complex I (CI) subunit NDUFB8, Complex II (CII) subunit SDHB, Complex III (CIII) subunit UQCRC2, Complex IV (CIV) subunit COX II, Complex V (CV) ATP synthase subunit alpha, as well as actin (upper). Bar graph depicts quantification of the abundance of each complex subunit relative to actin (lower). Experiment was performed once. (c) BN–PAGE immunoblot analysis of enriched mitochondria from B-LCLs of HCs (n = 3) and PPBL patients (n= 3), probed for CI (NDUFA9), CII (SDHA), CIII (UQCRC1), CIV (subunit I) and Tom20 (left). Summary bar graph (right). Representative of 4 independent experiments. (d) Representative mitotracker deep red (MTDR) and mitotracker red (MTR) staining of primary B cells from HCs (n = 3) and PPBL patients (n = 3). Bar graph summarizes the geometric mean fluorescence intensity (gMFI) of MTDR and MTR of both populations. Pooled data are represented as mean ± SEM. Statistical significance was assessed by two-sided Mann-Whitney test (a), two-sided unpaired t-test (c,d). * p < 0.05, ** p < 0.01, ns, not significant.
