D gal

Male C57BL/6J wild type mice (6~8 weeks old) were obtained from the Animal Core Facility of Nanjing Medical University. Animals were bred in a pathogen-free facility. Mice were randomly divided into five groups: (1) control group (Ctrl): mice were intraperitoneally (i.p.) injected with PBS only; (2) ALF group (ALF): mice simultaneously received 600 mg/kg D-galactosamine (D-Gal) (Sigma-Aldrich, St. Louis, MO, USA) and 100 μg/kg LPS (Sigma-Aldrich) dissolved in PBS by i.p. injection; (3–5) cell transplantation groups: mice received 600 mg/kg D-Gal and 100 μg/kg LPS via i.p. injection, and then 2 × 10⁶ MSC, MSC-COX2(+), or MSC-COX2(−) were injected via tail vein after 6 h, namely the MSC group, MSC-COX2(+) group, or MSC-COX2(−) group, respectively. For TAK1 inhibition, we administrated the specific TAK1 inhibitor 5z-7-ox (5 mg/kg, Sigma) to mice 1 h before LPS/D-Gal administration. To inhibit the EP4 receptor of PGE₂, we administered EP4-specific antagonist (GW627368X, 20 mg/kg, Cayman Chemical, Ann Arbor, MI, USA) 1 h before LPS/D-Gal treatment and every 24 h following MSC infusion. Blood and liver tissues were collected at the indicated time for further analysis.

L929 and HepG2 cell lines were purchased from the Korea Cell Line Bank. AML12 cells were obtained from the American Type Culture Collection (ATCC). L929 and HepG2 cells were cultured in Roswell Park Memorial Institute (RPMI) 1640 medium supplemented with 10% fetal bovine serum (FBS) and penicillin/streptomycin (Welgene, Daegu, Korea). AML12 cells were cultured in Dulbecco's Modified Eagle Medium (DMEM):F12 medium supplemented with 10% FBS, penicillin/streptomycin, insulin, transferrin, selenium, and dexamethasone, according to the manufacturer's instructions. LPS and actinomycin D (ActD) were obtained from Sigma‐Aldrich, and D‐gal was purchased from Cayman. Murine TNF‐α and human TNF‐α were obtained from PeproTech and ProSpec, respectively.