Fig. 5: Functional alteration and epigenetic reprogramming of KCs in liver metastasis.
a Schematic design of KC-tdT-DTR mice (H11DreERT2;Clec4f tdT-Cre;R26LSL-RSR-tdT-DTR) for tracing and ablating of KCs in normal tissues and metastatic tissues. b Acute depletion of normal liver KCs (left) and KC-derived LMAMs (right) by activation of DreERT2 using tamoxifen (TAM) and then by intraperitoneally (i.p.) administration of diphtheria toxin (DT) (scale bar, 50 μm). c Schematic diagram of pre-depletion of KCs and establishment of experimental liver metastasis models (PVi, portal vein injection). FC quantification showing DT-mediated genetic ablation of tdT+ KCs (n = 4 for PBS control group; n = 4 for DT-treated group). d Bar plots comparing liver metastasis burden of DT-treated mice (n = 5 for MC38; n = 5 for E0771) or PBS-treated control mice (n = 6 for MC38; n = 5 for E0771). The ex vivo bioluminescence value was normalised to the in vivo bioluminescence value obtained immediately after portal vein injection (day 0). e Schematic diagram of enrichment of macrophages for in vitro co-culture with Staurosporine-treated apoptotic E0771 cells labelled with CypHer5E. f FC quantification of distinct macrophage populations phagocyting apoptotic cancer cells (n = 5). g Normalised distribution of ATAC-seq or CUT&Tag-seq densities from 3 kb upstream to transcription start sites (TSS) to 3 kb downstream to transcription end sites (TES) of 118 KC-identity genes or 46 SAM genes. h,i Genome browser tracks of ATAC-seq or CUT&Tag-seq for transcriptional activator H3K27ac and transcriptional repressor H3K27me3 in the vicinities of selected SAM genes (h) and KC-identity genes (i). The enhancer regions are highlighted in yellow. j Mechanistic model showing the epigenetic reprogramming that underlies phenotypic and functional alterations of KCs in LvMet. Mean ± s.e.m. shown. P values were calculated by comparing individual animals using two-tailed unpaired (d) and paired (f) Mann–Whitney U-test.
