Effect of inhibiting TIM-4 function in Kupffer cells on liver graft rejection in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of inhibiting TIM-4 function in Kupffer cells (KCs) on liver graft rejection in mice and explore the underlying mechanism.</p><p><b>METHODS</b>Mouse models of orthotopic liver transplantation were treated with a control mAb group and TIM-4 mAb. The activated KCs were assayed with immunohistochemistry after operation. The expression of TIM-4 in KCs were assayed with Western blotting and RT-PCR and the levels of AST, ALT, TBIL, TNF-α, IFN-γ and CCL2 were assayed detected. The expression of TIM-4 in KCs was observed with laser confocal microscopy. HE staining was used to observe the microstructure of the liver tissues, and the number of CD25Foxp3T cells was determined using with flow cytometry; the proteins levels of p-P65and p-P38 were assayed with Western blotting. The donor mice were treated with clodronate liposomes to destroy the KCs in the liver before transplantation, and the liver grafts were examined for graft rejection.</p><p><b>RESULTS</b>The number of activated KCs in the liver graft increased progressively over time. Compared with the sham-operated group, the liver graft showed significantly increased TIM-4 protein and mRNA levels at 1, 3, and 7 days after transplantation (P<0.05) and increased levels of AST, ALT, TBIL, TNF-α, IFN-γ and CCL2 at 7 days (P<0.05). The graft in TIM-4 mAb group showed mild pathological changes with a mean RAI score of 2.67∓0.75, which was significantly lower than that in control mAb group (P<0.05). The mean survival time of the recipient mice was 53.8∓6.4 days in TIM-4 mAb group, significantly longer than that in the control mAB group (14.5∓2.9 days, P<0.05). Donor treatment with clodronate liposomes resulted in comparable RAI scores in TIM-4 mAb and control mAb groups (8.01∓0.64 vs 7.93∓0.56, P>0.05). The protein levels of p-P65 and p-P38 in TIM-4 mAb group were significantly lower than those in control mAb group (P<0.05), and CD25Foxp3T cells in the liver graft increased significantly in TIM-4 mAb group.</p><p><b>CONCLUSION</b>Inhibition of TIM-4 function in KCs reduces the production of inflammatory factors after liver transplantation possibly by inhibiting the NF-κB and MAPK signaling pathways and promoting the proliferation of Foxp3Treg cells to induce allograft tolerance.</p>

Tacrolimus alleviates acute liver graft rejection by inhibiting glucocorticoid-induced tumor necrosis factor-related protein ligand in rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the mechanism underlying the inhibitory effect of tacrolimus (FK506) against acute liver graft rejection.</p><p><b>METHODS</b>Rat models of orthotopic liver transplantation were divided into 3 groups, namely the tolerance group with Brown Norway (BN) rats as the donors and Lewis rats as the recipients, rejection group with Lewis rats as donors and BN rats as recipients, and FK506 group with the same donor-recipient pair as in the rejection group and FK506 treatment. The recipients were sacrificed 7 days after the transplantation, and the hepatic histology, cytokine levels, and glucocorticoid-induced tumor necrosis factor-related protein ligand (GITRL) expression in the liver and Kupffer cells were observed and detected.</p><p><b>RESULTS</b>Compared with the tolerance group, the rejection group showed increased GITRL expressions in the liver and Kupffer cells (P<0.05), which was significantly lowered by FK506 treatment (P<0.05). Acute liver graft rejection caused significantly elevated interferon-γ (IFN-γ) levels and decreased interleukin-10 (IL-10) levels in the plasma and Kupffer cells (P<0.05), and these changes were obviously attenuated by FK506 treatment (P<0.05).</p><p><b>CONCLUSION</b>The effect of FK506 in suppressing acute liver graft rejection is probably associated with down-regulated GITRL expression in the liver and Kupffer cells.</p>