Journal: Materials Today Bio

Article Title: Toll-like receptor 9-overexpressing red blood cell biomimetic microbubbles adsorb cell-free DNA to relieve steatotic liver ischemia-reperfusion injury

doi: 10.1016/j.mtbio.2026.103558

Figure Lengend Snippet: RBC-MBs promotes the polarization of macrophages towards the M2 phenotype by inhibiting the TLR9-MyD88 and cGAS-STING pathways (A-F) RBC-MB treatment significantly attenuated CpG DNA-induced upregulation of pro-inflammatory cytokines (A-B), key proteins in the TLR9-MyD88 (C-D) and cGAS-STING (E-F) pathways. RAW264.7 cells were treated with 1 μg mL -1 CpG DNA for 24 h, followed by incubation with 0.5 mL RBC-MBs (concentration: 1 × 10 8 particles mL -1 ) for 24 h, and then subjected to western blot analysis (A, C, E). IL-1α, TNF-α, IL-6, TLR9, MyD88, STING, and cGAS levels were normalized to the β-actin level in each sample. p-NF-κB, p-TBK1, and p-IRF3 levels were normalized to their respective total protein levels (NF-κB, TBK1, and IRF3) in each sample. These normalized values were then used for statistical analysis (B, D, F), n = 6. (G) RBC-MB treatment significantly attenuated CpG DNA-induced upregulation of CD86 in macrophages. RAW264.7 cells were treated with 1 μg mL -1 CpG DNA for 24 h, followed by incubation with 0.5 mL RBC-MBs (concentration: 1 × 10 8 particles mL -1 ) for 24 h, then immunostained with an anti-CD86 antibody (green) and DAPI (blue, nuclei), and imaged by fluorescence microscopy. Representative images (left panel) and quantitative fluorescence graph (right panel) are shown. Scale bar: 50 μm, n = 6. (H-J) RBC-MB treatment significantly inhibited hepatic IRI-induced polarization of macrophages toward the M1 phenotype (H) and activation of the TLR9-MyD88 and cGAS-STING pathways (I-J). MASLD rats underwent 45 min of hepatic ischemia followed by reperfusion. At 0, 6, 12, 18, and 24 h post-reperfusion, the rats were treated with either Con-MBs or RBC-MBs. Primary macrophages were isolated from rat livers, then co-stained with CD68 and CD163 followed by flow cytometric analysis (H), n = 3/4, or subjected to western blotting (I-J). CD206, iNOS, TLR9, MyD88, STING, and cGAS levels were normalized to the β-actin level in each sample, and these normalized values were used for statistical analysis (J), n = 3. For (B, D, F, G right panel , H right panel , J), error bars represent mean ± standard deviation. P values were calculated using the unpaired Student's t-test (B, D, F, G right panel ) or one-way analysis of variance (ANOVA) (H right panel , J). *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001; ns, not significant.(For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Article Snippet: Primary antibodies used included: rabbit polyclonal antibodies against TLR9 (A14642, Abclonal), NF-κB (A2547, Abclonal), MyD88 (A0980, Abclonal), cGAS (A8335, Abclonal), IL-1α (A2170, Abclonal), TNF-α (A0277, Abclonal), IL-6 (A0286, Abclonal), CD206 (A8301, Abclonal), CD86 (A16805, Abclonal), CD47 (A1838, Abclonal), and ATP1A (A0643, Abclonal); rabbit monoclonal antibodies against STING (13647, CST, Beverly, MA, USA), p-NF-κB (3033, CST), p-TBK1 (5483, CST), TBK1 (ab40676, Abcam), p-IκB (2859, CST), IκB (4812, CST), p-IRF3 (4947, CST), and β-actin (AC026, Abclonal).

Techniques: Incubation, Concentration Assay, Western Blot, Fluorescence, Microscopy, Activation Assay, Isolation, Staining, Standard Deviation