Although Gsk3 inhibition slightly reduced IL-10 expression in IR-livers, its impact on IL-12p40 gene induction was much more pronounced, leading to a significant increase in the IL-10/IL-12 ratio in the SB216763-treated group as compared with controls (Fig. 2G). Thus, active Gsk3β was essential for the pro-inflammatory immune response and the development of liver IRI. Its inhibition preferentially suppressed pro-inflammatory gene program, whereas IL-10 induction was relatively spared. To analyze liver protection mechanisms of Gsk3 inhibition, we differentiated between direct cytoprotection (by way of inhibition of MPTP) and immune regulation. Mice underwent adjunctive treatment with
astractyloside (Atr), an MTPT opener, or anti-IL-10 Ab together with Gsk3 inhibitor (SB216763), followed by liver IR insult. In contrast to its protective effects Talazoparib price in the heart,26, 27 treatment with Atr did
not affect the beneficial effect of Gsk3 inhibition in the liver. However, concomitant neutralization of IL-10 readily recreated liver damage. Hence, sALT levels in the Atr plus SB216763 treatment group were this website significantly lower as compared to those in Atr-treated or vehicle-treated groups (Fig. 3A, Atr/SB: 917 ± 104 versus Atr: 3,994 ± 739, P = 0.001; versus Ctl: 6,239 ± 725, P < 0.001). In marked contrast, sALT levels in SB plus anti-IL-10 Ab treatment group were significantly higher than in the SB216763 monotherapy group, Histidine ammonia-lyase and became comparable with those in controls (Fig. 3B, SB/anti-IL-10: 3,683 ± 720.3 versus SB: 769.0 ± 203.7; P = 0.02; versus Ctl: 5,691 ± 1,205, P = ns).
The histology evaluation showed the hepatocellular damage, corresponding with sALT levels in the respective animal groups (Fig. 3C). Consequently, IL-10 neutralization restored liver proinflammatory immune response against IR in SB-treated mice, as evidenced by increased TNF-α, IL-1β, IL-6, and CXCL10 expression (Fig. 3D). Thus, the liver protective mechanism of Gsk3 inhibition depends on IL-10-mediated immune regulation rather than the direct cytoprotection by way of mitochondria. As Gsk3β phosphorylation occurs spontaneously during liver IR, we then addressed the functional significance of its inactivation. As the PI3 kinase-Akt pathway has been shown in vitro to regulate Gsk3β phosphorylation downstream of TLR4 activation,12 we utilized wortmannin, an irreversible PI3 kinase-specific inhibitor, to test whether or not Gsk3β phosphorylation is PI3 kinase-dependent, and, if so, what is its pathophysiology role in liver IRI. Indeed, livers in wortmannin-treated mice were characterized by significantly lower levels of phosphorylated Gsk3β after IR (Fig. 4A) and suffered more severe injury at 6 hours of reperfusion as compared with vehicle-treated controls. This was most pronounced in the 60-minute liver ischemia setting, with the hepatocellular damage less severe than that recorded after 90 minutes of ischemia (Fig.