To delete p38α specifically in the hepatocytes, we generated mice carrying p38α floxed alleles13 and selleckchem the Afp-Cre transgene, expressing Cre under the control of the alpha-fetoprotein promoter, which is active during embryonic hepatic development. The liver-specific p38α knockout (KO) mice were kept in a C57BL/6 genetic background. Adult male mice weighing 20 ± 3 g were held in individual cages. Animals were distributed into four groups: two groups that underwent BDL (BDL wildtype [WT] and BDL p38α KO), and two sham-operated group

animals (sham WT and sham p38α KO). The total number of mice used was 36: eight BDL mice after 12 days cholestasis, 12 BDL mice after 28 days cholestasis, and 16 control mice. Animals were euthanized under anesthesia

at 12 and 28 days postsurgery. All mice received humane care according to the criteria outlined in the Guide for the Care and Use of Laboratory Animals (NIH publication 86-23 revised 1985). The study was approved by the Ethics Committee of Animal Experimentation and Welfare of the University of Valencia (Valencia, Spain). BDL was performed as described.10 Liver injury and function were assessed as Cytoskeletal Signaling inhibitor indicated in the Supporting Material and Supporting Figs. S1 and S2. For biochemical assays, western blotting, and real-time reverse-transcription polymerase

chain reaction (RT-PCR), see the Supporting Material. For histological analysis and immunofluorescence, see the Supporting Material. For binucleation rate and number of nuclei per field, 50-60 slides from all different animals were blindly scored. In BDL animals, foci with high inflammatory infiltrate were avoided. All results are given as mean ± standard deviation (SD). Y-27632 2HCl Significant differences were assessed by one-way analysis of variance (ANOVA) followed by a Tukey’s post-hoc test. Survival curves were constructed by the Kaplan-Meyer method and analyzed for differences using the score test of Cox proportional hazards model for grouped data. A survival curve was performed in order to assess if there were differences between the WT group and p38α KO mice. The mean life-span was significantly less in mice with a deficiency of p38α after BDL than in WT mice. The Kaplan-Meier curve (Fig. 1) showed that WT mice had a favorable response to BDL in comparison with KO mice (P < 0.01). BDL p38α KO mice had a 50% decrease in mean life-span (30.16 ± 4.06 days versus 59.2 ± 7.2 days) and a significant difference in maximum lifespan (76 days versus 106 days) versus WT BDL mice.