Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi. 2026 Mar;42(3):210-220.
ABSTRACT
Objective This study aimed to investigate the protective effect of a metformin (Met)-adipose-derived mesenchymal stem cell exosome (ADSC-Exo) complex (Met-Exo) against hepatic ischemia-reperfusion injury (IRI) and to determine whether this protection is mediated through the silent information regulator 1(SIRT1)-tissue inhibitor of metalloproteinase 3(TIMP3) axis. Methods Met-Exo was constructed and characterized by nanoparticle tracking analysis, Western blotting, and transmission electron microscopy (TEM). An in vitro model of hepatic IRI was established in mouse hepatocyte AML12 cells subjected to oxygen-glucose deprivation/re-oxygenation (OGD/R). Cell viability, apoptosis, and hepatocyte function markers (AST and ALT) were measured to compare the protective effects of Met-Exo, ADSC-Exo, and Met alone. A TranswellTM co-culture system was used to evaluate how macrophage polarization influences OGD/R-induced AML12 injury. AML12 cells were assigned to the following groups: Ctrl, OGD/R, Met, ADSC-Exo, Met-Exo, and macrophage-polarization groups (M0, M1, M1+Met-Exo, M1+pcDNA3.1, M1+pcDNA3.1-SIRT1, M1+pcDNA3.1-TIMP3). SIRT1 and TIMP3 protein levels in AML12 cells were determined by Western blot. Macrophage-polarization markers-inducible nitric-oxide synthase (iNOS) and arginase 1 (Arg1) were also quantified. In parallel, AML12 cells' viability, apoptosis, and hepatocellular function indices (AST& ALT) were assessed. A murine hepatic IRI model was constructed, and Met-Exo was administered to assess therapeutic efficacy in vivo. Results Met-Exo was successfully prepared. In vitro, Met-Exo attenuated OGD/R-induced hepatocyte injury, increased viability, reduced apoptosis, and lowered AST and ALT release. Met-Exo pre-treatment suppressed expression of the M1 marker iNOS and enhanced expression the M2 marker Arg1, thereby alleviating OGD/R damage in AML12 cells. OGD/R markedly decreased SIRT1 and TIMP3 expression in AML12 cells, whereas Met-Exo pre-treatment significantly up-regulated SIRT1 and consequently TIMP3 expression. In macrophage polarization experiments, M1 macrophages exacerbated AML12 injury, shown as decreased protein expression of SIRT1 and TIMP3, increased iNOS levels, reduced Arg1 levels, along with diminished AML12 cell viability, increased apoptosis, and elevated AST/ALT. Over-expression of either SIRT1 or TIMP3 reversed these detrimental effects, skewing macrophages toward the M2 phenotype and mitigating AML12 injury. In vivo, Met-Exo markedly ameliorated hepatic IRI in mice. Conclusion Met-Exo protects against hepatic IRI by activating the SIRT1-TIMP3 axis, thereby driving macrophage polarization toward the anti-inflammatory M2 phenotype, attenuating inflammation and apoptosis in hepatocytes subjected to OGD/R.
PMID:41930442