Journal: bioRxiv
Article Title: Efferocytosis Remodels Osteoclast Metabolism and Enhances Antibacterial Defense
doi: 10.64898/2026.10.13.759003
Figure Lengend Snippet: a , Heatmap showing expression of osteoclast-associated genes, TAM receptor family genes, and macrophage-associated genes during murine osteoclast differentiation (GSE147174). BMM, bone marrow-derived macrophages (M-CSF, 2 days); pOC, pre-osteoclasts (BMM + RANKL for 1 day); mOC, mature osteoclasts (BMM + RANKL for 3 days). n = 3 bulk RNA-seq samples per differentiation stage; each heatmap column represents one sample. b , Representative gel electrophoresis images of PCR products for Tyro3 , Axl , Mertk , and Actb in BMMs, pOCs, and mOCs. c , Quantitative PCR analysis of Tyro3 , Axl , and Mertk transcript levels in BMMs, pOCs and mOCs. d,e , Immunoblot analysis of AXL, MERTK, and β-actin expression in BMM, pOC, and mOC ( d ), with densitometric quantification ( e ). f,g , Immunofluorescence images of mouse femoral sections showing MERTK ( f ) and AXL ( g ) expression in bone-resident osteoclasts. MERTK and AXL are shown in red in f and g , respectively; CTSK is shown in green, and nuclei are shown in blue (DAPI). Quantification shows the number of receptor-positive multinucleated osteoclasts per bone perimeter and the percentage of osteoclasts positive for MERTK or AXL. Scale bars, 20 µm. h , Flow cytometric quantification of apoptotic neutrophil (aN) efferocytosis by BMMs and osteoclasts. i , Representative immunofluorescence images of BMMs and osteoclasts incubated with apoptotic neutrophils (aN). Phagocytes are shown in green, apoptotic neutrophils in red, and nuclei stained with DAPI (blue). White arrows indicate apoptotic cells with pyknotic nuclei, and yellow arrows indicate aN. Scale bars, 50 µm. j , Quantification of apoptotic neutrophil uptake by BMMs and osteoclasts following siRNA-mediated depletion of Axl or Mertk . The phagocytosis index was calculated as experimental engulfment (%) divided by control engulfment (%). Data are presented as mean ± s.d. Statistical significance was assessed using two-tailed unpaired t -tests ( h ) and one-way ANOVA followed by Tukey’s multiple comparisons test ( c,e,j ). n = 3 independent biological samples per group ( c,e,h,j ) and n = 5 mice ( f,g ). Each point represents one biological sample or one mouse, respectively; linked points in f,g denote measurements from the same mouse.
Article Snippet: C57BL/6J mice were obtained from the Southwest Hospital Animal Center (Chongqing, China), whereas Ly6G-tdTomato mice and Ctsk -Cre; Mertk flox/flox mice were obtained from Cyagen Biotechnology Co., Ltd. (Suzhou, China).
Techniques: Expressing, Derivative Assay, RNA Sequencing, Gel Electrophoresis, Real-time Polymerase Chain Reaction, Analysis, Western Blot, Immunofluorescence, Incubation, Staining, Control, Two Tailed Test