Role of pharmacogenetics and tacrolimus dosing in liver transplantation

IL-10 alleviates aTCMR by inhibiting NFATc1 signaling pathway of T cells after kidney transplantation

The cause of acute T cell-mediated rejection (aTCMR) is believed to be immune hyperfunction of T cells after kidney transplantation. Nowadays, calcineurin inhibitors are widely used to inhibit the proliferation of T cells when aTCMR occurs. However, the therapeutic dose window of these drugs is relatively narrow and long time use of these drugs may lead to serious side effects. Besides, whether IL-10, a new immune tolerance mediator, playing a therapeutic role on aTCMR remains unclear. The level of IL-10 decreased in patients with aTCMR, suggesting that IL-10 may be involved in the progression of aTCMR. IL-10 could inhibit the proliferation and metabolism of T cells in vitro and in vivo, accompanied by reducing the levels of IL-2, IFN-γ, and TNF-α. Moreover, we confirmed that IL-10 exerts immunosuppressive effects by inhibiting the NFATc1 signaling pathway of T cells. This viewpoint may provide a new therapeutic idea for clinical application.

Effect of CYP3A5 genotypes on pharmacokinetic of tacrolimus in colombian liver transplant patients

Background

Previous studies have reported a reduced tacrolimus dose-adjusted exposure in individuals expressing the CYP3A5*1 allele (rs 776746). However, information regarding Colombian liver transplantation patients is scarce. This study aimed to investigate the influence of CYP3A5 polymorphism on tacrolimus (TAC) pharmacokinetics in Colombian liver transplant patients.

Methods

This was a prospective, single-center, open-label, pharmacogenetic study in stable adult liver transplant recipients followed up between 2020 and 2022. To evaluate the longitudinal relationship between the Co/doses, dose, and Co and CYP3A5 polymorphisms, a generalized estimating equations model was used using a log-gamma distribution.

Results

We evaluated 16 patients who received TAC during the first 2 years after transplantation. CYP3A5*1 expression was observed 28% of patients. Patients with CYP3A5 expressors displayed lower C0 and C0/dose ratio and higher doses than those no expressors. We observed a lower C0/dose ratio in expresser recipients over 2 years of follow-up.

Conclusion

The expression of CYP3A5 in stable liver transplant patient appeared to have the greatest influence on tacrolimus pharmacokinetics over the first 2 years posttransplant.

Immunosuppressive enzyme-responsive nanoparticles for enhanced accumulation in liver allograft to overcome acute rejection

Acute rejection is a life-threatening complication after liver transplantation. Immunosuppressants such as tacrolimus are used to inhibit acute rejection of liver grafts in clinic. However, inefficient intragraft accumulation may reduce the therapeutic outcomes of tacrolimus. Here, an enzyme-responsive nanoparticle is developed to selectively enhance the accumulation of tacrolimus in liver allograft through enzyme-induced aggregation to refine immunotherapeutic efficacy of tacrolimus. The nanoparticles are composed of amphiphilic tacrolimus prodrugs synthesized by covalently conjugating tacrolimus and matrix metalloproteinase 9 (MMP9)-cleavable peptide-containing methoxy poly (ethylene glycol) to poly (l-glutamic acid). Upon exposure to MMP9, which is overexpressed in rejected liver allografts, the nanoparticles undergo a morphological transition from spherical micellar nanoparticles to microscale aggregate-like scaffolds. Intravenous administration of MMP9-responsive nanoparticles into a rat model of acute liver graft rejection results in enhanced nanoparticle accumulation in allograft as compared to nonresponsive nanoparticles. Consequently, the MMP9-responsive nanoparticles significantly inhibit intragraft inflammatory cell infiltration and proliferation, maintain intragraft immunosuppressive environment, alleviate graft damage, improve liver allograft function, abate weight loss and prolong recipient survival. This work proves that morphology-switchable enzyme-responsive nanoparticles represent an innovative strategy for selectively enhancing intragraft accumulation of immunosuppressive agents to improve treatment of liver allograft rejection.

Protective effect of FKBP12 on dextran sulfate sodium-induced ulcerative colitis in mice as a tacrolimus receptor

Ulcerative colitis (UC) is a multifactorial intestinal disease with a high incidence. In recent years, there has been an urgent need for pleiotropic drugs with a clear biosafety profile. Tacrolimus (TAC) is an immunosuppressant with stronger in vivo effects and better gastrointestinal absorption and is considered a potential treatment for UC. FKBP12 is a mediator of TAC immunosuppression; however, it is unclear whether it can participate in the development of UC in combination with TAC. The purpose of this study is to preliminarily validate the function of FKBP12 by establishing dextran sulfate sodium (DSS)-induced UC model and TAC treatment. The results revealed that TAC was effective in alleviating DSS-induced UC symptoms such as body weight and disease activity index (DAI). TAC significantly protects colonic tissue and attenuates DSS-induced histomorphological changes. In addition, FKBP12 is down-regulated in the intestinal tissue of DSS-induced UC mice and in serum samples of UC patients. In conclusion, our study revealed that FKBP12 may act as a TAC receptor to have anti-inflammatory and protective effects on DSS-induced UC in mice, which will provide a new option for the treatment of UC.