Fig. 4: The phagocytic receptor TREM2 in CD206hi testicular macrophages mediates the removal of Leydig cell-ejected mitochondria.
From: An extracellular vesicle-mediated mitochondrial transfer network critical for testosterone synthesis
a, Representative images of CD206hi and MHCIIhi tMacs sorted from Cyp17a1Cre; R26tdTomato; Cx3cr1GFP mice using FACS (n = 8 mice per group). Scale bars, 5 μm. b, Fluorescence intensity of tdTomato in CD206hi and MHCIIhi tMacs (n = 8 mice per group). c, Representative images of testes of Cyp17a1Cre; R26mitoD2 mice stained with CD206 and MHCII (n = 5 mice per group). Scale bars, 8 μm (main images) and 2 μm (magnified views of the boxed regions). d, Levels of mitoD2+ signal in CD206hi and MHCIIhi tMacs (n = 5 mice per group). e, Uniform manifold approximation and projection (UMAP) plots of tMacs. 1, 2 indicate tMac subsets. f, Heat map of differentially expressed genes and enriched GO terms in the scRNA-seq data of CD206hi and MHCIIhi tMacs. g, Trem2 expression levels, from the scRNA-seq data, in CD206hi and MHCIIhi tMacs. h, Representative images of TREM2 on CD206hi and MHCIIhi tMacs. The sections of the mouse testes were counterstained with DAPI (n = 5 mice per group). Scale bar, 10 μm. i, Levels of TREM2 expression on CD206hi and MHCIIhi tMacs (n = 5 mice per group). j, Flow cytometry analysis of LC-EVs labelled with Annexin V (n = 3 biological replicates). k, Experimental design overview. Following isolation from Cyp17a1Cre; R26mitoD2 mice, mitoD2+ LCs were transplanted into TAM-treated Cx3cr1CreER (control) and Cx3cr1CreER; Trem2fl/fl (cKO) mice. l, Representative images of the testes of control and cKO mice nine days after mitoD2+ LC transplantation. Sections of the testes were stained with IBA1 and counterstained with the nuclear dye TWO-PRO-3 (white; n = 4 mice per group). Scale bars, 5 μm. m, Percentage of tMacs containing mitoD2+ signal (n = 4 mice per group). n, Testosterone levels of control and cKO mice 14 days after TAM injections (n = 4 mice per group). o, Sperm counts of the two groups (n = 5 mice per group). p, Number of litters obtained from the two groups (n = 5 mice per group). q, Number of pups per litter (n = 5 mice per group). r, Grip strength of mice in the two groups (n = 5 mice per group). s, Muscle endurance of the two groups (n = 5 mice per group). j,n,r,s, Data are the mean ± s.e.m. m,o–q, Box plots: the box bounds depict the first to the third quartile, with the middle line indicating the median and the whiskers extending to the minimum and maximum values. b,d,f,g,i,m–s, Statistical significance was determined using a two-tailed Student’s t-test (d,n–s), two-tailed Mann–Whitney U-test (b,i,m), two-tailed Wilcoxon rank-sum test with Bonferroni correction for differentially expressed genes (f,g) or two-tailed permutation test with Benjamini–Hochberg correction for gene set enrichment analysis (f). Con, control. Schematic in k,r,s created in BioRender. Xia, K. (2026) https://biorender.com/zw5vz3a. Source numerical data are provided.
