polymorphisms of glutathione s-transferase m1 and t1: genetic risk factor for vitiligo
DESCRIPTION
Introduction: vitiligo is the result of the interaction of genetic, biochemical, environmental and immunological factors. Oxidative stress has a significant pathogenic role in vitiligo, and is normally contrasted by various non-enzymatic and enzymatic antioxidant systems, including glutathione S-transferases (GSTs). The “null” allele (which causes the lack of production of the corresponding protein) of GST isoforms M1 and T1 may be found, with inter-ethnically variable frequency, in a relevant part of the general population, and is associated to various oxidative-stress related diseases. Aims & Scope: to define the prevalence of GSTM1 and GSTT1 null polymorphisms in vitiligo patients and healthy controls from Sicily and Calabria, and the correlation of such genotypes with the disease. Material and Methods: polymerase chain reaction was performed on buccal swabs of 58 non-segmental vitiligo patients (28 males, 30 females) and 150 healthy controls (71 males, 79 females) to define their GSTM1 and GSTT1 genotype (null/active). Results: the GSTM1/GSTT1 double-null genotype is significantly more frequent in vitiligo patients than in controls (p=0.041), while this is not true for either single-null genotype. Neither the GSTM1 genotype nor the GSTT1 genotype are correlated to the disease. Comments: the two other papers on GSTM1/GSTT1 genotype and vitiligo agree with our data for which concerns the association of the double-null genotype with a significantly increased risk for the disease, while they differ about disease correlation with either GST null genotype (GSTM1 in one paper, GSTT1 in another, none of the above in our casuistic). Discrepancies are probably due to a different “genetic setup” of the populations studied, which determines a different relative importance of GSTM1 and GSTT1 in the global balance of the antioxidant system. Thus, possession of the null allele for one GST isoform can variably increase the risk for vitiligo, depending on the relative importance of that isoform, while the reduction of the antioxidant potential due to the simultaneous lack of both GST isoforms (double null genotype) is significant in any configuration of the antioxidant system and always constitutes a risk factor for the disease. Oxidative stress and antioxidant response could be linked to the dysregulated response observed in vitiligo. As suggested in a recent paper, cultured keratinocytes derived from vitiligo patients have higher levels of reactive oxygen species (ROS) and a characteristic dysregulation of the cytokine, chemokine and growth factor pattern. Future perspectives include : - GST genotyping of other populations, ethnically different from those currently described in literature, because of the high variability of the frequency of GST - Disclaimer- This PPT is loaded as student material "as is", from the VRF Vitiligo Master Class Barcelona November 2011; VRF does not endorse or otherwise approve it.TRANSCRIPT
POLYMORPHISMS OF GLUTATHIONE
S-TRANSFERASE M1 AND T1: GENETIC RISK FACTOR FOR
VITILIGO
POLYMORPHISMS OF GLUTATHIONE
S-TRANSFERASE M1 AND T1: GENETIC RISK FACTOR FOR
VITILIGOFabrizio Guarneri1, Alessio Asmundo2, Daniela Sapienza2, Serafinella Patrizia
Cannavò1
Fabrizio Guarneri1, Alessio Asmundo2, Daniela Sapienza2, Serafinella Patrizia
Cannavò11Section of Dermatology and 2Section of Legal
Medicine, Department of Territorial Social Medicine,
University of Messina, AOU “G. Martino”, Messina, Italy
1Section of Dermatology and 2Section of Legal Medicine,
Department of Territorial Social Medicine, University of Messina, AOU “G. Martino”, Messina,
Italy
The International School of Vitiligo
and Pigmentary Disorders
Barcelona, 2-5 November 2011
The International School of Vitiligo
and Pigmentary Disorders
Barcelona, 2-5 November 2011
GLUTATHIONE S-TRANSFERASE
GLUTATHIONE S-TRANSFERASE
Enzymes for detoxification of electrophyle compounds by conjugation with
glucuronates
Frequent genetic polymorphism
Main groups of polymorphisms: GSTA, GSTM,
GSTP, GSTT
The “null” genotype of GSTM1 and GSTT1 can be
found in a significant part of the general population
Enzymes for detoxification of electrophyle compounds by conjugation with
glucuronates
Frequent genetic polymorphism
Main groups of polymorphisms: GSTA, GSTM,
GSTP, GSTT
The “null” genotype of GSTM1 and GSTT1 can be
found in a significant part of the general population
GLUTATHIONE S-TRANSFERASE
GLUTATHIONE S-TRANSFERASE
NULL GENOTYPES IN GENERAL POPULATION
NULL GENOTYPES IN GENERAL POPULATION
GSTM1 GSTT1
Asmundo et al. 54.67% 24.67%
Griffiths et al. 36% 8%
Ada et al. 51.9% 17.3%
Uhm et al. 51.4% 52.6%
GSTM1 GSTT1
Asmundo et al. 54.67% 24.67%
Griffiths et al. 36% 8%
Ada et al. 51.9% 17.3%
Uhm et al. 51.4% 52.6%
The GSTM1 and GSTT1 “null” genotypes are linked
to skin cancers, psoriasis, allergic dermatoses
The GSTM1 and GSTT1 “null” genotypes are linked
to skin cancers, psoriasis, allergic dermatoses
GLUTATHIONE S-TRANSFERASE
GLUTATHIONE S-TRANSFERASE Enzymes for detoxification of electrophyle
compounds by conjugation with glucuronates
Frequent genetic polymorphism
Main groups of polymorphisms: GSTA, GSTM,
GSTP, GSTT
The “null” genotype of GSTM1 and GSTT1 can be
found in a significant part of the general population
Enzymes for detoxification of electrophyle compounds by conjugation with
glucuronates
Frequent genetic polymorphism
Main groups of polymorphisms: GSTA, GSTM,
GSTP, GSTT
The “null” genotype of GSTM1 and GSTT1 can be
found in a significant part of the general population
Uhm YK, Yoon SH, Kang IJ, Chung JH, Yim SV, Lee MH. Association of glutathione S-transferase gene polymorphisms (GSTM1 and GSTT1) of vitiligo in Korean population. Life Sci. 2007; 81 (3): 223-7.
Liu L, Li C, Gao J, Li K, Gao L, Gao T. Genetic polymorphisms of glutathione S-transferase and risk of vitiligo in the Chinese population. J Invest Dermatol. 2009; 129 (11): 2646-52.
Uhm YK, Yoon SH, Kang IJ, Chung JH, Yim SV, Lee MH. Association of glutathione S-transferase gene polymorphisms (GSTM1 and GSTT1) of vitiligo in Korean population. Life Sci. 2007; 81 (3): 223-7.
Liu L, Li C, Gao J, Li K, Gao L, Gao T. Genetic polymorphisms of glutathione S-transferase and risk of vitiligo in the Chinese population. J Invest Dermatol. 2009; 129 (11): 2646-52.
GLUTATHIONE S-TRANSFERASES AND
VITILIGO
GLUTATHIONE S-TRANSFERASES AND
VITILIGO
AIM OF THE STUDYAIM OF THE STUDY
To define the possible role of the GSTM1 and/or GSTT1 “null” genotype as a risk
factor for the development of vitiligo in a population of patients from a Mediterranean
area (Sicily and Calabria)
To define the possible role of the GSTM1 and/or GSTT1 “null” genotype as a risk
factor for the development of vitiligo in a population of patients from a Mediterranean
area (Sicily and Calabria)
MATERIALS AND METHODSMATERIALS AND METHODS
Study population: 58 consecutive vitiligo patients
(28 M, 30 F; mean age 25.22 ± 11.37 years),
all Caucasian, born and living in Sicily or Calabria
Control population: 150 healthy subjects, with a
similar age and sex distribution
Cell sample obtained by buccal swab
GSTM1 and GSTT1 genotyping
Study population: 58 consecutive vitiligo patients
(28 M, 30 F; mean age 25.22 ± 11.37 years),
all Caucasian, born and living in Sicily or Calabria
Control population: 150 healthy subjects, with a
similar age and sex distribution
Cell sample obtained by buccal swab
GSTM1 and GSTT1 genotyping
GSTM1 AND GSTT1 GENOTYPING
GSTM1 AND GSTT1 GENOTYPING
Extraction by “Chelex® 100” method PCR amplification Electrophoresis of PCR products on ultrathin
polyacrylamide gel Silver staining Bands of interest:
- 480 bp (GSTT1) - 215 bp (GSTM1)
Internal control: beta-globin gene
Extraction by “Chelex® 100” method PCR amplification Electrophoresis of PCR products on ultrathin
polyacrylamide gel Silver staining Bands of interest:
- 480 bp (GSTT1) - 215 bp (GSTM1)
Internal control: beta-globin gene
MATERIALS AND METHODSMATERIALS AND METHODS
Study population: 58 consecutive vitiligo patients
(28 M, 30 F; mean age 25.22 ± 11.37 years),
all Caucasian, born and living in Sicily or Calabria
Control population: 150 healthy subjects, with a
similar age and sex distribution
Cell sample obtained by buccal swab
GSTM1 and GSTT1 genotyping
Statistical analysis: Chi square test (significant if
p<0.05)
Study population: 58 consecutive vitiligo patients
(28 M, 30 F; mean age 25.22 ± 11.37 years),
all Caucasian, born and living in Sicily or Calabria
Control population: 150 healthy subjects, with a
similar age and sex distribution
Cell sample obtained by buccal swab
GSTM1 and GSTT1 genotyping
Statistical analysis: Chi square test (significant if
p<0.05)
RESULTSRESULTS
Genotype
GSTM1 Null ActivePatients 35 23Controls 82 68 p = 0.459
GSTT1 Null Active Patients 22 36Controls 19 113 p = 0.057
Genotype
GSTM1 Null ActivePatients 35 23Controls 82 68 p = 0.459
GSTT1 Null Active Patients 22 36Controls 19 113 p = 0.057
RESULTSRESULTS
GSTM1 GSTT1 Patients Controls
active active 15 49
active null 8 19 p = 0.535
null active 21 64 p = 0.858
null null 14 18 p = 0.041
GSTM1 GSTT1 Patients Controls
active active 15 49
active null 8 19 p = 0.535
null active 21 64 p = 0.858
null null 14 18 p = 0.041
ASSOCIATION BETWEEN THE “NULL” GST GENOTYPE AND
VITILIGO
ASSOCIATION BETWEEN THE “NULL” GST GENOTYPE AND
VITILIGO Uhm YK et al., Life Sci. 2007
Vitiligo associated with GSTM1 null and GSTM1/GSTT1 “double null”
Liu L et al., J Invest Dermatol. 2009Vitiligo associated with GSTT1 null and GSTM1/GSTT1 “double null”
Present studyVitiligo associated with GSTM1/GSTT1 “double null”
Uhm YK et al., Life Sci. 2007Vitiligo associated with GSTM1 null and GSTM1/GSTT1 “double null”
Liu L et al., J Invest Dermatol. 2009Vitiligo associated with GSTT1 null and GSTM1/GSTT1 “double null”
Present studyVitiligo associated with GSTM1/GSTT1 “double null”
AutoimmuneAutoimmune
ToxicToxic NeurogenicNeurogenic
VITILIGO: PATHOGENIC HYPOTHESES
VITILIGO: PATHOGENIC HYPOTHESES
Kostyuk VA et al., Antioxid Redox Signal 2010
We found significantly suppressed mRNA and protein expression of GST M1 isoform, and higher-than-normal levels of both 4-hydroxy-2-nonenal (HNE)-protein adducts and H2O2 in the cultures of keratinocytes derived from unaffected and affected skin of vitiligo patients
The broad spectrum of major cytokines, chemokines, and growth factors was dysregulated in both blood plasma and cultured keratinocytes of vitiligo patients
Exogenous HNE added to normal keratinocytes induceda vitiligo-like cytokine pattern, and H2O2 overproduction accompanied by adaptive upregulation of catalase and GSTM1 genes
Kostyuk VA et al., Antioxid Redox Signal 2010
We found significantly suppressed mRNA and protein expression of GST M1 isoform, and higher-than-normal levels of both 4-hydroxy-2-nonenal (HNE)-protein adducts and H2O2 in the cultures of keratinocytes derived from unaffected and affected skin of vitiligo patients
The broad spectrum of major cytokines, chemokines, and growth factors was dysregulated in both blood plasma and cultured keratinocytes of vitiligo patients
Exogenous HNE added to normal keratinocytes induceda vitiligo-like cytokine pattern, and H2O2 overproduction accompanied by adaptive upregulation of catalase and GSTM1 genes
DIFFERENT GSTM1/T1 GENOTYPESIN VITILIGO PATIENTS:
POSSIBLE EXPLANATIONS
DIFFERENT GSTM1/T1 GENOTYPESIN VITILIGO PATIENTS:
POSSIBLE EXPLANATIONS
Different “gene pool”
Variable importance of GST M1 and T1 in the “setup” of antioxidant mechanisms in different populations
Environmental conditions
Life style
Different “gene pool”
Variable importance of GST M1 and T1 in the “setup” of antioxidant mechanisms in different populations
Environmental conditions
Life style
FUTURE PERSPECTIVESFUTURE PERSPECTIVES
GST genotyping of various populations
Further studies on association between GST polymorphisms and vitiligo
Exact definition of the role of GSTs in the pathogenic mechanisms of vitiligo
GST genotyping of various populations
Further studies on association between GST polymorphisms and vitiligo
Exact definition of the role of GSTs in the pathogenic mechanisms of vitiligo
OUR NEW PROJECTOUR NEW PROJECT
Simultaneous definition of the genotype of all possibly
pathogenically relevant antioxidant enzymes
Correlation between each genotype and vitiligo
Calculation of the “antioxidant potential” of a subject and the individual contribution of each enzyme to it
Definition of individual disease risk and possible preventive measures
Study of connections among autoimmune, oxidative and neural mechanisms
Simultaneous definition of the genotype of all possibly
pathogenically relevant antioxidant enzymes
Correlation between each genotype and vitiligo
Calculation of the “antioxidant potential” of a subject and the individual contribution of each enzyme to it
Definition of individual disease risk and possible preventive measures
Study of connections among autoimmune, oxidative and neural mechanisms