Single-cell transcriptomic analysis reveals the association of Ccl6+Ccr2+Arg1+ macrophages with renal interstitial fibrosis in AKI
Fig 5
Ccl6+Ccr2+Arg1+ cell infiltration correlates with the progression of renal interstitial fibrosis following AKI.
(a) Schematic representation of the experimental workflow using the uIRI model to induce AKI. Kidney samples were harvested 7 days post-injury (n = 6). (b) Transcriptional analysis of Ccl6, Ccr2, Retnla, and Arg1 expression levels in kidney tissue, showing significant upregulation in the AKI group compared to sham controls (n = 6). (c) Histological analysis at day 7 post-AKI. H&E staining reveals tubular necrosis, epithelial detachment, and brush border loss. PSR and Masson staining demonstrate significant interstitial fibrosis. Quantification of tubular injury scores and fibrosis areas highlights incomplete renal repair and fibrotic remodeling (n = 6). Scale bar: 50 μm. (d, e) Colocalization analysis of Ccl6, Ccr2, and Arg1 in the OSOM region of the kidney at day 7 post-AKI. Immunofluorescence-based quantification showed significantly increased Pearson’s correlation coefficients among the three markers, indicating enhanced co-expression within the same cells (n = 6). Scale bar: 50 μm (f) Quantification of Ccl6+Ccr2+ and Ccl6+Ccr2+Arg1+ cells revealed a significant increase in kidneys 7 days after AKI compared to sham controls (n = 6). (g, h) The infiltration of Ccl6+Ccr2+Arg1+ cells positively correlate with the severity of renal interstitial fibrosis. (i) Western blot analysis of Ccr2 protein levels in kidney tissue shows significant difference between AKI and sham controls. Results are presented as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001, ns: no significance.