Fig. 3: RXRα and RARγ respond to corpse-derived signals to upregulate the phagocytic programme.
From: Stem cells tightly regulate dead cell clearance to maintain tissue fitness
a, Left, schematic of cell position with respect to nearest corpse. Fractions of RXRα+ (middle) or RARγ+ (right) in position relative to corpses across catagen. n = 300 cells across 3 mice per stage. b, Left, induction of corpses in quiescent hair follicles. Right, quantification of total FACS-isolated HFSCs that are apoptotic (annexin V+), TAM-family+ and RXRα+ per mouse in control (Sox9-creER−, n = 2) or corpse-positive (Sox9-creER+, n = 4) mice. c, Left, in vitro strategy to expose naive HFSCs to corpses directly. Middle, time-course quantification of total HFSCs that are RXRα+ versus containing a corpse. n = 4 experiments per time point. Right, quantification of RXRα+ and RARγ+ HFSCs at 30 min after corpse addition. n = 6 (RXRα+) and n = 7 (RARγ+) experiments. d, Left, in vitro strategy to expose corpses to naive Rxra wild-type or Rxra-cKO HFSCs, with or without the pan RAR-family antagonist AGN193109 (AGN). FACS-based quantification of total HFSCs that are both TAM-family+ and lysosomehi (middle) or contain engulfed corpses (right) at 4 h after corpse addition. Data represents one (of two) independent experiments. Each dot represents data from one experimental replicate: medium condition (n = 3 wild type, n = 3 Rxra-cKO), for corpses: +Veh (n = 6 wild type, n = 6 Rxra-cKO) and +AGN (n = 3 wild type, n = 3 Rxra-cKO). Pairwise independent two-sided Student’s t-tests, P values indicated. In box plots, the centre line is the median, box edges delineate first and third quartiles and whiskers extend to 1.5× the inter-quartile range. Further details on statistics and reproducibility in Methods. See also Extended Data Fig. 6 for additional supporting experiments.
