Macrophage-to-myofibroblast transition exacerbates renal fibrosis after ischemia-reperfusion injury via the TGF-β1/Smad3 signaling pathway
10.12464/j.issn.1674-7445.2025308
- VernacularTitle:巨噬细胞向肌成纤维细胞转分化通过TGF-β1/Smad3信号通路加重缺血-再灌注损伤后肾纤维化
- Author:
Yanyan YANG
1
;
Jingrong HUANG
1
;
Pengli LUO
1
;
Tao TAO
2
Author Information
1. Department of Nephrology, the Affiliated Hospital of Qinghai University, Qinghai Provincial Clinical Research Center for Chronic Kidney Disease, Xining 810000, China.
2. Department of Urology，the Affiliated Hospital of Qinghai University.
- Publication Type:OriginalArticle
- Keywords:
Macrophage;
Ischemia-reperfusion injury;
Acute kidney injury;
Macrophage-to-myofibroblast transition;
Renal fibrosis;
Collagen;
Transforming growth factor β1;
Smad3
- From:
Organ Transplantation
2026;17(2):266-274
- CountryChina
- Language:Chinese
-
Abstract:
Objective To clarify the role and underlying mechanism of macrophage-to-myofibroblast transition (MMT) in renal fibrosis that develops after acute kidney injury (AKI) induced by ischemia-reperfusion injury (IRI). Methods Mouse AKI model was generated by renal ischemia-reperfusion. Animals were randomized into control (Con), sham operated (Sham), and IRI groups sacrificed at 1 d (IRI 1 d), 3 d (IRI 3 d) and 14 d (IRI 14 d) after reperfusion (n = 5). Renal injury was assessed by renal coefficient, serum creatinine (Scr) and kidney injury molecule-1 (KIM-1). Periodic acid-Schiff (PAS) staining was used to evaluate tubular damage and inflammatory infiltration. Masson staining and immunohistochemistry were employed to quantify collagen deposition, α-smooth muscle actin (α-SMA) and type I collagen (COL I). Flow cytometry was used to determine macrophage infiltration and phenotype. MMT was identified by flow cytometry plus immunofluorescence. Transforming growth factor (TGF)-β1/Smad3 pathway proteins were examined by Western blotting. Results Compared with Sham group, renal coefficient, Scr and KIM-1 rose in IRI 1 d group, renal coefficient and KIM-1 remained elevated in IRI 3 d group. Compared with the IRI 1 d group, the renal coefficient and KIM-1 decreased in the IRI 14 d group. Compared with the IRI 3 d group, the renal coefficient, Scr and KIM-1 decreased in the IRI 14 d group (all P < 0.05). PAS revealed the most severe tubular injury at IRI 3 d. Masson staining showed progressively increasing collagen deposition, while immunohistochemistry demonstrated α-SMA and COL I rising from day 1 and persisting to day 14 (all P < 0.05). Macrophage infiltration increased from day 1 and lasted to day 14 (P < 0.05). M1 macrophages peaked at day 1 then declined, whereas M2 macrophages increased at day 3 and remained high through day 14 (P < 0.05). MMT began to rise at day 3 and continued to day 14 and M2 macrophages were the predominant source of MMT cells (all P < 0.05). Compared with Sham group, TGF-β1 protein was up-regulated and p-Smad3/Smad3 ratio was elevated in all IRI groups (all P < 0.05). Conclusions M2 macrophages promote post-IRI-AKI renal fibrosis via MMT, a process closely linked to activation of the TGF-β1/Smad3 signaling pathway.
