Influence of glutathione S-transferase M1 and T1 polymorphisms with acute rejection in Iranian liver transplant recipients

Influence of GSTM1, GSTT1, and GSTP1 genetic polymorphisms on disorders in transplant patients: a systematic review

The glutathione-S-transferase (GST) enzymes are phase II isoenzymes responsible for protection against free radicals and xenobiotics. Since these proteins are described as polymorphic, polymorphisms in genes that encode them may alter enzymatic function and contribute to oxidative stress. In this context, such polymorphisms were already associated with several diseases and multiple therapeutic outcomes. A systematic review was performed to evaluate studies regarding the association between polymorphisms in three genes encoding enzymes of the GST family - GSTM1, GSTT1, and GSTP1 - and disorders in transplant patients. A total of 125 articles on which inclusion and exclusion criteria were applied were identified at PubMed database. Thirty-two studies met the target criteria and were included in the review. The mechanisms by which GST genotypes influence the development of disorders in transplant patients differ by disorder: they may participate in it by decreasing metabolism of drugs administered to patients undergoing transplantation, then exposing them to greater toxicity; by decreasing the repair ability against oxidative stress; or by encoding proteins that may be recognized as foreign, setting of an alloimmune reaction. Although some results are better established - such as GSTM1 null genotype's role in the development of toxicity events in transplant patients - others require further evidences, as GST influence on the development of pulmonary decline and posttransplant diabetes mellitus (PTDM). The importance of investigating these associations lies in a personalized medicine, in which the high-risk genotype patient has its treatment individualized and its care for prophylaxis and surveillance increased, potentially reducing this population's morbimortality.

Signaling molecules orchestrating liver regenerative medicine

The liver is in charge of more than 500 functions in the human body, which any damage and failure to the liver can significantly compromise human life. Numerous studies are being carried out in regenerative medicine, as a potential driving force, toward alleviating the need for liver donors and fabrication of a 3D-engineered transplantable hepatic tissue. Liver tissue engineering brings three main factors of cells, extracellular matrix (ECM), and signaling molecules together, while each of these three factors tries to mimic the physiological state of the tissue to direct tissue regeneration. Signaling molecules play a crucial role in directing tissue fabrication in liver tissue engineering. When mimicking the natural in vivo process of regeneration, it is tightly associated with three main phases of differentiation, proliferation (progression), and tissue maturation through vascularization while directing each of these phases is highly regulated by the specific signaling molecules. The understanding of how these signaling molecules guide the dynamic behavior of regeneration would be a tool for further tailoring of bioengineered systems to help the liver regeneration with many cellular, molecular, and tissue-level functions. Hence, the signaling molecules come to aid all these phases for further improvements toward the clinical use of liver tissue engineering as the goal.

Association of Glutathione S-Transferase theta 1 and mu 1 Genes Polymorphisms with the Susceptibility of Myocardial Infarction in Bangladesh

Background

Myocardial infarction is one of the leading causes of morbidity and mortality worldwide. Oxidative stress plays a vital role in the pathogenesis of atherosclerosis leading to myocardial infarction and Glutathione S-transferases (GSTs) act as detoxifying enzymes to reduce oxidative stress. The aim of the present study was to investigate the associations of the GST (T1 & M1) gene polymorphism with the susceptibility of myocardial infarction in the Bangladeshi population.

Methods

A case-control study on 100 cardiac patients with MI and 150 control subjects was conducted. The genotyping of GST (T1 & M1) gene was done using conventional Polymerase Chain Reaction.

Results

The percentage of GSTM1 genotypes was significantly (p< 0.01) lower in patients compared to control subjects while the GSTT1 genotypes were not significantly different between the study subjects. The individual with GSTM1 null allele was at 2.5-fold increased risk {odds ratio (OR)= 2.5; 95 % confidence interval (95 % CI)= 1.4 to 4.3; p< 0.01} of experiencing MI while individual with either GSTM1 or GSTT1 genotypes was at lower risk. In the case of GST M1 and GST T1 combined genotype, patients having both null genotypes for GST M1 and GST T1 gene showed significantly (p< 0.01) higher risk of experiencing MI when compared to control subjects (OR= 3.5; 95% CI= 1.7-7.2; p< 0.001).

Conclusion

Thus our recent study suggested that GSTM1 alone and GSTM1 and T1 in combination augments the risk of MI in Bangladeshi population.

Liver Tissue Engineering as an Emerging Alternative for Liver Disease Treatment

Chronic liver diseases affect thousands of lives throughout the world every year. The shortage of liver donors for transplantation has been the main driving force to employ alternative methods such as liver tissue engineering (LTE) in fabricating a three-dimensional transplantable liver tissue or enhancing cell delivery techniques alleviating the need for liver donors. LTE consists of three components, cells, ECM (extracellular matrix), and signaling molecules, which we discuss the first and second. The three most common cell sources used in LTE are human and animal primary hepatocytes, and stem cells for different applications. Two major categories of ECM are used to mimic the microenvironment of these cells, named scaffolds and microbeads. Scaffolds have been made by numerous methods with a wide range of synthetic and natural biomaterials. Cell encapsulation has also been utilized by many polymeric biomaterials. To investigate their functions, many properties have been discussed in the literature, such as biochemical, geometrical, and mechanical properties, in both of these categories. Overall, LTE shows excellent potential in assisting hepatic disorders. However, some challenges exist that prevent the practical use of it clinically, making LTE an ongoing research subject in the scientific society.

Distribution of Glutathione S-Transferase Omega Gene Polymorphism with Different Stages of HBV Infection Including Hepatocellular Carcinoma in the Egyptian Population

BACKGROUND

Infection with hepatitis B virus (HBV) is a major global public health problem, with a wide spectrum of clinical manifestations. Human cytosolic glutathione-S-transferases (GSTs) include several classes such as alpha (A), mu (M), pi (P), sigma (S), zeta (Z), omega (O) and theta (T). The present study aimed to investigate the role of GST omega genes (GSTO1 and GSTO2) in different groups of patients infected with HBV.

MATERIALS AND METHODS

HBV groups were classified according to clinical history, serological tests and histological analysis into normal carriers (N), acute (A), chronic (CH), cirrhosis (CI) and hepatocellular carcinoma (HCC) cases. The study focused on determination of the genotypes of GST omega genes (GSTO1 and GSTO2) and GST activity and liver function tests.

RESULTS

The results showed that GSTO1 (A/A) was decreased in N, A, CH, CI and HCC groups compared to the C-group, while, GSTO1 (C/A) and GSTO1(C/C) genotypes were increased significantly in N, A, CH, CI and HCC groups. GSTO2 (A/A) was decreased in all studied groups as compared to the C-group but GSTO2(A/G) and GSTO2(G/G) genotypes were increased significantly. In addition, GST activities, albumin and TP levels were decreased in all studied groups compared to the C-group, while the activities of transaminases were increased to differing degrees.

CONCLUSIONS

The results indicate that GSTO genetic polymorphisms may be considered as biomarkers for determining and predicting the progression of HBV infection.

Association of GSTT1 and GSTM1 gene polymorphisms with coronary artery disease in North Indian Punjabi population: a case-control study

BACKGROUND

Glutathione S-transferases are metabolic enzymes which are responsible for detoxification of endogenous (products of oxidative stress) as well as exogenous (drugs, pesticides, herbicides, environmental pollutants and carcinogens) products. Dysfunctional detoxification enzymes are responsible for the production of oxidative stress; a major contributor to the development of coronary artery disease (CAD).

OBJECTIVES

The present case-control study aimed to investigate the association of GSTT1 and GSTM1 gene polymorphisms with CAD.

METHODS

In the present study, 200 patients diagnosed with CAD and 200 age, sex and population subgroup matched healthy controls were enrolled. The GSTT1 and GSTM1 gene polymorphisms were examined using multiplex PCR.

RESULTS

The frequency of GSTT1 null genotype was significantly (p=0.038) lower in patients with CAD (6.00%) than in controls (12.50%). The GSTT1 null genotype showed protection against CAD (OR=0.45, 95% CI 0.22 to 0.92, p=0.028). The frequency of GSTM1 null genotype was significantly (p=0.004) higher in patients (31%) compared with controls (18%). The GSTM1 null genotype conferred twofold increased risk of developing CAD (OR=2.05, 95% CI 1.28 to 3.27, p=0.003).

CONCLUSIONS

The results concluded that the GSTT1 null genotype showed protection against CAD while the GSTM1 null genotype might be involved in the pathogenesis and development of CAD.

Association of GSTO2 (N142D), GSTT1, and GSTM1 Polymorphisms With Graft-Versus-Host Disease in Allogeneic Hematopoietic Stem Cell Transplant Recipients

OBJECTIVES

Graft-versus-host disease is a major problem after bone marrow transplant. GSTM1, GSTT1, and GSTO2 are important genes that interfere with xenobiotic and drug metabolism. Polymorphisms of these genes may influence the metabolism of immunosuppressive drugs given for inhibition of graft-versus-host disease and may influence their susceptibility to diseases, which bone marrow transplant could alleviate.

MATERIALS AND METHODS

We examined the polymorphisms of 2 groups: The first group was composed of 88 patients who had undergone a bone marrow transplant and 100 otherwise healthy persons; the second group was composed of 54 patients without graft-versus-host disease and 34 patients with graft-versus-host disease. We used polymerase chain reaction-restriction fragment length polymorphism method for genotyping GSTO2 and also for multiplexing polymerase chain reactions for GSTT1 and GSTM1 genotypes.

RESULTS

No significant association existed between the genotypes GSTO2 (DD: P = .458, OR 0.422), GSTM1 (P = .349, OR 1.52), or GSTT1 (P = .887, OR 1.086), and the incidence of GVHD. Moreover, we saw no association between these polymorphisms and the problems that lead to bone marrow transplant (GSTO2: DD, P = .181, OR 0.465; GSTM1: P = .699, OR 0.892; GSTT1: P = .656, OR 0.845). We showed that men have more bone marrow transplants than do women (P = .019, OR 2.034).

CONCLUSIONS

Our results show that these poly-morphisms may have no effect on the metabolism of drugs used to treat graft-versus-host disease and also, may play no significant role in creating the problems that lead to bone marrow transplant.

Glutathione S-transferase M1 gene polymorphism is associated with susceptibility to impaired long-term allograft outcomes in renal transplant recipients

BACKGROUND

Despite improved post-transplantation care, progress in long-term kidney allograft survival of diabetic renal transplant recipients (pre-DM RTR) is worse than that of non-diabetic recipients (non-DM). We hypothesized that there are other potential risk factors, that predispose RTR to adverse renal allograft outcomes.

METHODS

A total of 323 transplant recipients who underwent renal transplantation between March 2000 and January 2008 were recruited. The composite end-point consisted of serum creatinine (SCr) doubling, graft failure, and death. Baseline clinical data were recorded, and polymerase chain reaction-restriction fragment length polymorphism measurements of interleukin (IL)-4, IL-10, IL-23, glutathione S-transferase (GST)A1, GSTM1, and GSTP1 polymorphisms were determined. The risk factors for developing the primary outcome were analyzed among these clinical and genetic factors.

RESULTS

Within a mean follow-up of 71.1 ± 24 months, there were 43 (13.3 %) patients with the primary outcome. Stepwise multivariate Cox regression analysis was used to determine the risk factors for the primary outcome of RTR. Renal transplant recipients who possessed the GSTM1 null genotype had a 2.2-fold risk (95 % CI: 1.10-4.40; P = 0.026) of developing the primary outcome. Additionally, RTR that had DM before transplantation (aHR: 3.31; 95 % CI: 1.77-6.20; P = 0.0002) or changes in SCr 6 to 12 months after transplantation (aHR: 2.83; 95 % CI: 1.29-6.19; P = 0.0095) had an increased risk of developing the primary outcome.

CONCLUSIONS

In addition to the adverse role played by DM, the GSTM1 null genotype also has an unfavorable influence on the long-term allograft outcome of RTR.

Influence of GSTO2 (N142D) genetic polymorphism on acute renal rejection

Acute renal allograft rejection remains an important problem following kidney transplantation. Several immunological and non-immunological factors intervene in renal graft rejection. Glutathione S-transferase super family is one of the important enzymes for biotransformation of both exogenous and endogenous xenobiotic compounds such as immunosuppressive drugs. The new class of this family is omega that includes two subunits GSTO1 and GSTO2. In this study 282 samples were collected from renal recipients of Namazi hospital in Shiraz-Iran during 2007-2010 years. Also 300 healthy samples as control group were collected from Shiraz population, included in our study. The primary outcome of this study was defined as biopsy-proven acute rejection during 1 year of renal transplantation. We applied polymerase chain reaction-restriction fragment length polymorphism method for determination of GSTO2 N142D polymorphism. Our result showed no significant association between GSTO2 polymorphism and acute rejection. Also this genetic variant has no significant effect with the risk of end stage renal disease. Cadaveric donor type for acute rejection significantly differed between acute rejection and non acute rejection patients (P=0.004). The combination effect of donor type and GSTO2 polymorphism indicates DD genotype with cadaver donor type increase risk of acute rejection (OR=3.82, 95% CI 1.80-12.37, P=0.02).

Impact of glutathione S-transferase T1 gene polymorphisms on acute cellular rejection in living donor liver transplantation

It has previously been demonstrated that glutathione S-transferase T1 (GSTT1) genetic mismatch between recipient and donor is a risk factor for developing immune-mediated hepatitis following liver transplantation and for antibody-mediated rejection in renal transplantation. Little is known whether the GSTT1 gene polymorphism affects the incidence of acute cellular rejection (ACR) following living donor liver transplantation (LDLT). Patients underwent LDLT at Nagoya University or Kyoto University, Japan, between 2004 and 2009. Genotyping of GSTT1 genes (null or present genotype) was conducted in recipients and donors. A total of 155 LDLT cases were examined. Forty-seven recipients (30.3%) developed early ACR. There was no association of recipient GSTT1 genotype with ACR incidence. However, ACR incidence was significantly higher in recipients transplanted from GSTT1 present genotype donors than in those transplanted from GSTT1 null genotype donors [odds ratio (OR)=2.64, 95% confidence interval (CI)=1.12-5.83, p=0.016]. Moreover, GSTT1 recipient/donor genotype mismatch (present/null or null/present) was significantly associated with ACR development (OR=2.28, 95% CI=1.12-4.61, p=0.022). The genotyping of GSTT1 in recipients and donors might be useful to stratify the liver transplant recipients according to risk of ACR.

Association of GSTM1 null allele with prostate cancer risk: evidence from 36 case-control studies

BACKGROUND

Glutathione S-transferase M1 (GSTM1) is thought to be involved in detoxifying several carcinogens and may play a vital role in tumorigenesis. Numerous studies have evaluated the association between GSTM1 null/present polymorphism and risk of prostate cancer (PCa). However, the results remain inconsistent. To derive a more precise estimation, we performed a meta-analysis.

METHODOLOGY/PRINCIPAL FINDINGS

A comprehensive search was conducted to identify all eligible case-control studies. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. The overall association was significant (OR = 1.28, 95% CI: 1.11-1.48, P = 0.001). Moreover, subgroup analyses showed GSTM1 null genotype significantly associated with PCa risk among Asians (OR = 1.35, 95% CI: 1.03-1.78, P = 0.03) but not among Caucasians (OR = 1.12, 95% CI: 0.96-1.31, P = 0.16). In addition, we did not find that smoking modified the genotype effect on the risk of PCa.

CONCLUSIONS/SIGNIFICANCE

The present meta-analysis suggested that GSTM1 null allele was a low-penetrant risk factor for PCa among Asians.

Genetic variations in human glutathione transferase enzymes: significance for pharmacology and toxicology

Glutathione transferase enzymes (GSTs) catalyze reactions in which electrophiles are conjugated to the tripeptide thiol glutathione. While many GST-catalyzed transformations result in the detoxication of xenobiotics, a few substrates, such as dihaloalkanes, undergo bioactivation to reactive intermediates. Many molecular epidemiological studies have tested associations between polymorphisms (especially, deletions) of human GST genes and disease susceptibility or response to therapy. This review presents a discussion of the biochemistry of GSTs, the sources-both genetic and environmental-of interindividual variation in GST activities, and their implications for pharmaco- and toxicogenetics; particular attention is paid to the Theta class GSTs.