Hui-Peng Tseng

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) prevents lipopolysaccharide (LPS)-induced, sepsis-related severe acute lung injury in mice

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is an energy metabolism-related enzyme in the glycolytic pathway. Recently, it has been reported that GAPDH has other physiological functions, such as apoptosis, DNA repair and autophagy. Some in vitro studies have indicated immunological aspects of GAPDH function, although there is no definite study discussing the advantage of GAPDH as a therapeutic target. Here, we show that GAPDH has an anti-inflammatory function by using a lipopolysaccharide (LPS)-induced, sepsis-related severe acute lung injury (ALI) mouse model, which is referred to as acute respiratory distress syndrome (ARDS) in humans. GAPDH pre-injected mice were protected from septic death, and their serum levels of proinflammatory cytokines were significantly suppressed. In lung tissue, LPS-induced acute injury and neutrophil accumulation were strongly inhibited by GAPDH pre-injection. Pulmonary, proinflammatory cytokine gene expression and serum chemokine expression in GAPDH pre-injected mice were also reduced. These data suggest the therapeutic potential of GAPDH for sepsis-related ALI/ARDS.

Identification of the indoleamine 2,3-dioxygenase nucleotide sequence in a rat liver transplant model

A tryptophan catabolizer, indoleamine 2,3-dioxygenase (IDO) is highly expressed in the placenta and plays an essential role in maternal tolerance. Recent data have shown that the administration of an IDO inhibitor blocked not only maternal tolerance but also liver allograft tolerance. However, little is known about the induction of IDO in liver allografts, although a gene specific for tryptophan 2,3-dioxygenase (TDO) is believed to be expressed in the liver. In the present study, we investigated whether IDO is induced in liver allografts. Synthetic oligonucleotide primers based on the mouse IDO cDNA sequence were used to amplify RNA derived from livers of donor, syngeneic or allogeneic OLT rats. RNA encoding IDO was induced in the rat allogeneic liver after orthotopic liver transplantation (OLT), but not in syngeneic OLT. The rat nucleotide sequence of the RT-PCR products obtained from OLT livers revealed identities of 89% homology to the mouse IDO and of 68% to the human IDO. This study demonstrated the presence of RNA encoding IDO in allogeneic OLT livers, which may be involved in the immune response after liver transplantation.

Homogenous phenomenon of graft liver CYP2C19 genotypes after living donor liver transplantation

Eur J Clin Invest 2012; 42 (4): 352–356

Donor graft does not affect the P450 2C19 genotype expressed in peripheral blood in recipients of living donor liver transplantation

Chiu K‐W, Tai W‐C, Nakano T, Tseng H‐P, Cheng Y‐F, Jawan B, Goto S, Chen C‐L. Donor graft does not affect the P450 2C19 genotype expressed in peripheral blood in recipients of living donor liver transplantation. 
Clin Transplant 2010: 24: 830–834.

Clusterin may be involved in rat liver allograft tolerance.

Little is known about the possible role of complement inhibitors on tolerance induced by liver allografts. Clusterin, which is a plasma glycoprotein, inhibits cytolytic membrane attack complex (MAC) of complement by binding to soluble C5b-7 complex. The role of clusterin in relation to the naturally achieved tolerance in a rat orthotopic liver transplantation (OLT) has not been investigated before. Here we determined the kinetics of clusterin expression at different post-transplantation time points in a tolerogenic model (DA-PVG) where rejection was naturally overcome without any immunosuppressive drugs in comparison with the syngenic OLT model (DA-DA). Peripheral blood and liver tissues were taken from OLT at various post-operative time points. A strong expression of soluble clusterin was observed on post-transplantation day 7, which occurred at the peak of the rejection in this tolerogenic OLT model. The expression of clusterin remained strong even after tolerance was achieved. The intensity of clusterin expression was much stronger when compared with the syngenic OLT (DA-DA) model after OLT. A strong expression of clusterin mRNA was also observed in the tolerogenic model on post-OLT day (POD) 7 and the expression persisted when compared with the syngenic model on post-OLT day 60. Our data have shown that the strongest levels of clusterin during the reaction phase in tolerogenic OLT may be involved in tolerance induction.

Biological interactions of CYP2C19 genotypes with CYP3A4*18, CYP3A5*3, and MDR1-3435 in living donor liver transplantation recipients

BackgroundPolymorphisms in CYP2C19 are related to the metabolic oxidation of drugs to varying degrees. The CYP3A4*18, CYP3A5*3, and MDR1-3435 variant alleles are very important, particularly in tacrolimus metabolism in organ transplant rejection.AimThe aim of this study is o explore possible interactions among different CYP2C19 genotypes, namely, between homozygous extensive metabolizers (HomEM), heterozygous extensive metabolizers (HetEM), and poor metabolizers (PM), and the CYP3A4*18, CYP3A5*3, and MDR1-3435 variants in living donors and patients who received a living donor liver transplant (LDLT).MethodsThis prospective study enrolled 133 living donors and 133 corresponding recipients. On the basis of the HomEM, HetEM, and PM CYP2C19 genotypes, the distributions of CYP3A4*18 (exon 10; T878C), CYP3A5*3 (intron 3; A6986G), and MDR1-3435 (exon 26; C3435T) genotypes were analyzed for single nucleotide polymorphisms among donors and recipients.ResultsAmong 102 HomEM genotypes, including 56 donors and 46 recipients, 91.2% of individuals harbored the T/T genotype of CYP3A4*18; 53.9% possessed G/G, and 34.3% had A/G genotypes of CYP3A5*3; and 38.2% had C/C and 50.0% had C/T genotypes at MDR1-3435. Among 130 HetEM genotypes, including 58 donors and 72 recipients, 97.7% of individuals possessed T/T genotype at CYP3A4*18; 50.0% harbored G/G and 41.5% had A/G genotypes at CYP3A5*3; and 40.0% had C/C and 49.2% had C/T genotypes at MDR1-3435. In 34 PMs, including 19 donors and 15 recipients, 88.2% had T/T genotypes at CYP3A4*18; 41.2% had G/G and 58.8% had A/G genotypes at CYP3A5*3; and 47.1% possessed C/C and 47.1% had C/T genotypes at MDR1-3435. On the basis of the CYP2C19 genotypes, no statistically significant distribution of genotypes were observed between donors and recipients for all genotypes of CYP3A4*18, CYP3A5*3, and MDR1-3435 (P >0.05).ConclusionsIn conclusion, the CYP2C19 genotypes do not affect the expression of CYP3A4*18, CYP3A5*3, or MDR1-3435 variants, which are independently distributed among donors and recipients during LDLT.

Prolongation of heart allograft survival of rats treated by a Th2 inhibitor

In terms of Th1/Th2 balance in response to signals given during donor antigen presentation, induction of tolerance is more often correlated with Th2-type than with Th1-type reactions. However, in our study, heart allograft survival was prolonged by treatment of rats with a Th2 inhibitor. Suplatast tosilate (IPD; Taiho; Tokyo, Japan) is a novel immunoregulator that suppresses IgE production and eosinophil infiltration through selective inhibition of interleukin (IL)-4 and IL-5 synthesis by Th2-like cells but not IFN-gamma production in Th1 cells. Five LEW rats of DA heart grafts were treated with IPD (100 microg/day, p.o.) for 10 days. Heart allograft survival of all IPD-treated cases was prolonged more than 14 days while the beating of heart grafts in control groups was stopped within 9 days. In an in vitro study, the cell proliferation both in Con A blast and in mixed lymphocyte reaction assay was suppressed by IPD in dose-dependent manner. We could at least in part conclude that Th2 inhibition might temporarily suppress heart allograft rejection.

Telomerase activity in rat liver allografts.

BACKGROUND Telomerase activity in grafts may be involved in the alteration of cellular senescence after transplantation or its relevant immunological events. METHODS At the age of 20 weeks, donor livers harvested from DA (RT1a) were orthotopically transplanted into PVG (RT1c) or LEW (RT1(1)) rats. Rats having undergone orthotopic liver transplantation (OLT; DA-PVG) naturally overcome rejection, whereas all OLT (DA-LEW) rats die from acute rejection within 14 days. Telomerase activity in liver allografts was measured at various intervals post OLT. RESULTS At day 7 when the most severe rejection episode was observed in OLT (DA-LEW) and OLT (DA-PVG), the telomerase activity was significantly higher than in syngeneic OLT (DA-DA) rats, in which no rejection occurred. Telomerase activity in tolerogenic OLT (DA-PVG) livers remained elevated for at least 2 months. CONCLUSION These results suggest that telomerase activity in allogeneic OLT livers may reflect regenerating hepatocytes or activation of lymphocytes and/or hematopoietic stem cells associated with rejection or tolerance.

Induction of Antinuclear Antibodies by De Novo Autoimmune Hepatitis Regulates Alloimmune Responses in Rat Liver Transplantation

Concanavalin A (Con A) is a lectin originating from the jack-bean and well known for its ability to stimulate T cells and induce autoimmune hepatitis. We previously demonstrated the induction of immunosuppressive antinuclear autoantibody in the course of Con A-induced transient autoimmune hepatitis. This study aimed to clarify the effects of Con A-induced hepatitis on liver allograft rejection and acceptance. In this study, we observed the unique phenomenon that the induction of transient de novo autoimmune hepatitis by Con A injection paradoxically overcomes the rejection without any immunosuppressive drug and exhibits significantly prolonged survival after orthotopic liver transplantation (OLT). Significantly increased titers of anti-nuclear Abs against histone H1 and high-mobility group box 1 (HMGB1) and reduced donor specific alloantibody response were observed in Con A-injected recipients. Induction of Foxp3 and IL-10 in OLT livers of Con A-injected recipients suggested the involvement of regulatory T cells in this unique phenomenon. Our present data suggest the significance of autoimmune responses against nuclear histone H1 and HMGB1 for competing allogeneic immune responses, resulting in the acceptance of liver allografts in experimental liver transplantation.

Western blotting analysis for quantitative detection of CYP2C19 expression in liver tissues in the setting of living donor liver transplantation.

BACKGROUND The cytochrome P450 (CYP) drug-metabolizing enzymes play an important role in cellular metabolism. Therapeutic failure or drug toxicity in the period after liver transplantation (LT) is influenced by the drug metabolizing capacity of the graft. The expression levels of CYP2C19 enzyme are often used as an indicator of the functioning of the CYP system. The aim of the present study was to assess the CYP2C19 protein expression in the setting of living donor liver transplantation (LDLT) by using western blotting analysis. METHODOLOGY We performed CYP2C19 genotyping of liver biopsy samples obtained from 24 donors and 8 recipients each in the pre- and post-LT periods, after which we analyzed the CYP enzyme activity by using western blotting analysis. RESULTS The CYP2C19/β-actin ratio, which was an indicator of CYP expression, was 61.75% (23-100%) in donors, 59.13% (15-100%) in pre-LT recipients and 46.71% (12-67%) in post-LT recipients (p>0.05). The CYP2C19 expression levels associated with different genotypes were as follows: homozygous extensive metabolizers (HomEMs; n=24), 56.63±24.74%; heterozygous extensive metabolizers (HetEMs; n=15), 63.0±25.14% and poor metabolizers (PMs; n=1), 82.0% (p>0.05). CONCLUSIONS Western blotting analysis showed low CYP2C19 protein expression not only in samples from the pre- and post-LT recipients but also from the donors.