Fig 1: ALK1-BMP9/10 axis regulates KC development(A) Mouse BM monocytes were cultured in the presence of CSF1 and indicated concentrations of human ac-LDL, prior to analyzed for expression of indicated genes by qPCR. Data are pooled from 2 experiments. One-way ANOVA with Bonferroni post-test compared with 0 ng/mL.(B) NicheNet circos plot highlighting conserved ligand-receptor pairs and induced target genes between KCs and indicated niche cells in human and mouse.(C) Feature plots showing expression of ALK1 (Acvrl1) in human myeloid cells (left) and GDF2/BMP10 in CD45- cells (right).(D) Livers were harvested from Fcgr1-CrexAcvrl1fl/fl mice or Acvrl1fl/fl or Acvrl1+/+ controls and KCs examined (left) and quantified (right) using VSIG4 expression.(E) Expression of indicated KC markers by mac populations in Fcgr1-CrexAcvrl1fl/fl or Acvrlfl/fl control mice. Data are pooled from 3 independent experiments with n = 9 per group. Student’s t test.(F) Expression of indicated markers in livers of Fcgr1-CrexAcvrl1fl/fl or Acvrl1fl/fl or Acvrl1+/+ control mice by confocal microscopy. Scale bars, 50 µm. Images are representative of 2 mice per group.(G) Schematic of chimera experiment setup.(H) % chimerism normalized to levels in blood Ly6Chi monocytes in Clec4f-Dtr mice 7 or 13 days after DT administration following partial irradiation and receiving either Acvrlfl/fl or Fcgr1-CrexAcvrlfl/fl BM 4 weeks earlier. Data are pooled from 2 independent experiments with n = 10–12 mice per group.(I) Schematic of Fc trap experiment setup.(J) Representative FACS plots showing VSIG4 and CLEC2 expression by total macs. Numbers represent % of total mac population in the indicated gate (left) and % of VSIG4+ and VSIG4- macs among total CD45+ cells in the different treatment conditions. One-way ANOVA with Bonferroni post-test. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. See also Figure S8.