Premium
The catalase gene promoter and 5ʹ‐untranslated region variants lead to altered gene expression and enzyme activity in vitiligo
Author(s) -
Mansuri M.S.,
Jadeja S.D.,
Singh M.,
Laddha N.C.,
Dwivedi M.,
Begum R.
Publication year - 2017
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1111/bjd.15681
Subject(s) - vitiligo , haplotype , biology , genotype , microbiology and biotechnology , exon , genotyping , single nucleotide polymorphism , untranslated region , allele , gene , genetics , messenger rna
Summary Background Oxidative stress is considered to be the initial event in the course of vitiligo. The enzyme catalase ( CAT ) is mainly involved in cellular defence against oxidizing agents through detoxifying H 2 O 2 . Objectives The aims were (i) to assess erythrocyte CAT enzyme activity and lipid peroxidation ( LPO ) levels as well as CAT mRNA expression in skin and blood; (ii) to investigate CAT gene promoter rs7943316, rs1001179, 5ʹ‐untranslated region rs1049982, and exon (rs17886350, rs11032709, rs17880442, rs35677492) polymorphisms; and (iii) to perform genotype/haplotype–phenotype correlation analyses in patients with vitiligo and controls from Gujarat. Methods CAT activity and LPO levels were measured spectrophotometrically. CAT mRNA levels were estimated using real‐time polymerase chain reaction ( PCR ) by the SYBR Green method. Single‐nucleotide polymorphism genotyping was performed using PCR –restriction fragment length polymorphism and amplification‐refractory mutation system– PCR analyses. Results Patients with vitiligo showed significantly decreased CAT mRNA expression in lesional and nonlesional skin and in blood, with reduced CAT activity compared with that of controls. CAT –89A/T and –20T/C polymorphisms were significantly associated with patients, especially with active and generalized vitiligo, whereas no association was observed for –262G/A and exon polymorphisms. The A –262 T –89 C –20 haplotype with variant alleles was found to be associated with 6·4‐fold risk of vitiligo. Genotype/haplotype–phenotype correlation analyses revealed that individuals with susceptible genotypes/haplotype for CAT –89A/T and –20T/C polymorphisms showed significantly decreased CAT mRNA /activity, and only –89A/T polymorphisms showed significantly increased LPO levels compared with wild‐type genotypes/haplotype. Conclusions The present study proposes the crucial role of CAT and its allelic variants in oxidative stress‐mediated pathogenesis of vitiligo.