5-10.0 μg/mouse;

R&D, St. Louis, MO) or with an equal volume of the vehicle [a phosphate-buffered saline (PBS) solution]. To follow animal survival, we monitored the mice every 12 hours for 1 week. Primary hepatocytes, obtained from mouse livers by collagenase digestion and cultured on collagen-coated plates,23 were routinely grown at 37°C with 5% CO2 in Dulbecco’s modified Eagle’s medium/F12 medium with 10% fetal bovine serum under a normoxic atmosphere or were exposed to hypoxia (1% O2 and 5% CO2) as previously described24, 25 Z-VAD-FMK cost (see the supporting information). In some experiments, conditioned media from GAS6-expressing HEK293 cells (100 ng GAS6/mL) or from control HEK293 pcDNA3-transfected cells were added to cultured click here mouse hepatocytes.26 Cell survival was measured with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and trypan blue exclusion. Cell and nuclear extracts were prepared as previously described,27 and protein levels were analyzed with specific antibodies (see the supporting information). The results are expressed as means and standard deviations; the number of individual experiments is detailed in the figure legends. Statistical significance

was established by one-way analysis of variance followed by Dunnett and Tukey-Kramer post hoc tests. Animal survival was evaluated with the Kaplan-Meier method and compared

with the log-rank test. We evaluated whether I/R modulated hepatic GAS6 homeostasis in WT C57BL/6 mice subjected to partial ischemia for 90 minutes; we assessed the GAS6 mRNA content and GAS6 levels in serum after different reperfusion times. The GAS6 mRNA levels, determined from liver biopsy samples, fell early after reperfusion and remained below control levels up to 16 hours after reperfusion (Fig. 1A). In contrast, 上海皓元医药股份有限公司 enzyme-linked immunosorbent assay analyses of serum indicated a time-dependent increase in the levels of GAS6 detected as soon as 3 hours after reperfusion, and they remained above control levels for 24 hours after reperfusion (Fig. 1B). Although this model of partial I/R typically results in maximal liver damage between 4 and 8 hours after reperfusion, increased serum alanine aminotransferase (ALT) levels were already detected as soon as 1 hour after reperfusion (659 ± 284 U/mL), and this coincided with the decrease in hepatic GAS6 mRNA levels and the initiation of the progressive increase observed in GAS6 serum levels. Thus, GAS6 homeostasis is regulated during hepatic I/R. The model of partial hepatic I/R follows a typical time-dependent pattern characterized by initial tissue damage that is resolved within 24 to 48 hours because of liver regeneration.