Tet2 ^ΔMye promoted intrahepatic expansion of pMDMs in liver fibrosis model. (A) Chimeric mice with liver fibrosis were constructed by transplantation of PBS (scramble), CD45.2⁺Tet2^+/+CD11b⁺ myeloid cells (WT-MT), or CD45.2⁺Tet2^−/−CD11b⁺ myeloid cells (KO-MT) into CD45.1 recipient mice, followed by repeated CCl₄ treatment (n = 4 for each group). CD45.2⁺Tet2^+/+ CD11b⁺ and CD45.2⁺Tet2^−/− CD11b⁺ cells were isolated from CD45.2 Tet2^+/+ and Tet2^−/− littermates. (B) Picrosirius red staining (scale bar, 125 μm) and statistical analysis of liver fibrosis in scramble, WT-MT, and KO-MT mice (n = 4 for each group). (C) Ishak score evaluation based on Sirius red staining and H&E staining in livers of scramble, WT-MT, and KO-MT mice (n = 4 for each group). (D) Expression levels of collagen I and α-SMA were measured by IHC (scale bar, 100 μm). (E and F) Frequency of CD45.2⁺ cell populations in peripheral blood (E) and liver (F) of scramble, WT-MT, and KO-MT mice (n = 4 for each group). (G and H) IF (G) (scale bar, 50 μm) and statistical analysis (H) of CD45.2⁺ MDMs in livers of scramble, WT-MT, and KO-MT mice (n = 4 for each group). Yellow: anti-CD45.2, blue: DAPI, red: anti-F4/80, and green: anti-Ly6c (n = 4). (I) Statistical analysis of the frequency of CD45.2⁺ MDMs in livers of scramble, WT-MT, and KO-MT mice evaluated by flow cytometry (n = 4 for each group). (J) Expansion of Tet2^−/− pMDMs and Tet2^−/− pMDMs was quantified by CFSE staining in vitro. Representative histograms show differences in CFSE signals between the two groups (n = 3 for each group). (K) Frequency of CD86⁺ MDMs (M1) and CD206⁺ MDMs (M2) evaluated by flow cytometry in the liver of WT-MT and KO-MT mice (n = 4 for each group). Data are representative of at least two independent experiments with similar results (B–K). All data are shown as mean ± SD and were analyzed by one-way ANOVA with Tukey’s multiple comparison test (B, C, E, F, H, and I) or two-way ANOVA with Sidak’s multiple comparison test (K). ***P < 0.001; **P < 0.01; *P < 0.05; P > 0.05 not significant (ns).