Hypoxia-preconditioned bone marrow mesenchymal stem cells alleviate acute liver failure in association with the...

Although bone marrow-derived mesenchymal stem cell (BMSC) offers considerable therapeutic potential, the regenerative capacity of these cells is markedly compromised by the adverse microenvironment of the injured liver. Hypoxic preconditioning (HP) enhances the adaptability of BMSC. This study explored HP-BMSC therapy for acute liver failure (ALF), specifically examining the potential regulatory effects involving the VEGF-related factors and B-cell immunity.

BMSCs were cultured under normoxic (21% O₂) or HP (1% O₂) conditions for 24 h, followed by protein and mRNA quantification of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), hepatocyte growth factor receptor (c-Met), C-X-C chemokine receptor type 4 (CXCR4), and stromal cell-derived factor-1 (SDF-1) by Western blot and RT-qPCR, respectively. ALF was induced in male C57BL/6J mice through D-galactosamine/LPS administration. Mice were randomized into four experimental groups (n = 6/group): controls, ALF, ALF + normoxic BMSC, and ALF + HP-BMSC. Cell transplantation was carried out through the tail vein immediately 5 min after the injection of the modeling drug. Four hours post-intervention, serum and tissue samples were collected for comprehensive analyses including liver biochemistry, inflammatory mediators, histology, and potential mechanisms.

HP significantly enhanced HIF-1α, VEGF, PCNA, c-Met, CXCR4, and SDF-1 expression in BMSC (all P < 0.001). In ALF mice, HP-BMSC treatment produced superior therapeutic outcomes than normoxic BMSC. Liver function improved, as shown by reduced total bilirubin and aminotransferase levels (P < 0.05). The treatment also reduced inflammation, lowering interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) while raising interleukin-10 (IL-10) levels (all P < 0.01). Early regenerative signals were enhanced, with immunofluorescence (IF) showing strong PCNA expression, Western blot indicating elevated hepatic VEGF, c-MET, and HGF proteins, and RT-qPCR confirming increased PDGF and VEGF mRNA levels. Immunohistochemistry (IHC) showed reduced hepatic B lymphocyte infiltration, and IF further revealed expanded CD24⁺CD38⁺ B cell populations.

HP BMSC transplantation correlates with early molecular events in acute liver failure mice, including upregulation of VEGF, HGF, and c-Met expression and changes in CD24⁺CD38⁺ B lymphocyte subsets, providing correlative evidence for involvement of the VEGF/c-Met pathway.