Ranno Rätsep

Association analysis of IL19, IL20 and IL24 genes in palmoplantar pustulosis.

Background  Interleukin (IL) 19, IL‐20 and IL‐24 belong to the IL‐10 cytokine family and have been identified to play a role in the regulation of epidermal functions and in inflammation. The genes encoding IL‐19, IL‐20 and IL‐24 are located within a gene cluster on chromosome 1q31–32 and carry frequent genetic variations.

Gene expression study of IL10 family genes in vitiligo skin biopsies, peripheral blood mononuclear cells and sera

Background  Vitiligo is a pigmentation disorder, the cause of which is complex and not yet fully understood. There is a significant change of epidermal cytokines in involved skin of patients with vitiligo compared with uninvolved skin and skin of healthy controls, thus suggesting a possible involvement of cytokines in the pathogenesis of vitiligo.

Expressional changes in the intracellular melanogenesis pathways and their possible role the pathogenesis of vitiligo

BACKGROUND Main pathway in human melanocytes through which signal from the melanocortin system reaches the melanogenesis enzymes is cAMP/PKA pathway and it is modulated by Wnt and MAPK pathways. In our previous study we established significant increase of melanocortin receptor expression in unaffected skin of vitiligo patients compared to healthy subjects. OBJECTIVE The aim of this study was to assess the gene expression profile of the intracellular signalling pathways linking melanocortin system with enzymes involved in melanogenesis. METHODS Using QRT-PCR method, mRNA expression levels of eight genes related to signal transduction from the melanocortin system to melanogenesis enzymes was measured in lesional and non-lesional skin of vitiligo patients and in the skin of healthy control subjects. Following genes were analyzed in the study: MITF, CREB1, p38, USF1, PIK3CB (PI3K), RPS6KB1, LEF1 and BCL2. RESULTS The mRNA levels of MITF, LEF1, p38, PIK3CB and RPS6KB1 were decreased in lesional skin of vitiligo patients compared to skin of healthy control subjects. We also found increased expression of USF1 and BCL2 in non-lesional skin of vitiligo patients compared to skin of healthy control subjects. mRNA levels of MITF and BCL2 were decreased in lesional skin of vitiligo patients compared to non-lesional skin of vitiligo patients. CONCLUSIONS Present study indicates increased expression of the genes of the intracellular melanogenesis pathway in the non-lesional skin of vitiligo patients. This finding suggests activation of melanogenesis pathway in the non-lesional skin of vitiligo.

Polymorphisms in the ATG16L1 gene are associated with psoriasis vulgaris.

Psoriasis is an immune-mediated inflammatory disorder of the skin with a complex pathogenesis and a strong genetic component (1). Several regions in the genome, including the psoriasis susceptibility locus 1 (PSORl), have been identified as conferring susceptibility to psoriasis (2—4). However, the complete genetic background of psoriasis remains to be established. Autophagy is a fundamental biological process that is involved in cell growth and plays a role in innate and adaptive immunity. In particular, autophagy-selective responses contribute to inflammatory bowel disease (IBD) (5, 6), neurodegeneration (7), and cancer (8). The ATG16L1 protein, which is encoded by the ATG16L1 gene (2q37), is a key component of a large protein complex essential for autophagy (9), and polymorphisms within this gene have been reported to be associated with Crohns disease (5). Taking into consideration that genes in the autophagy pathway play an important role in inflammation and immunity, and as a part of our ongoing research on the impact of genetic variants to the risk of psoriasis vulgaris, the aim of the present study was to assess whether polymorphisms in ATG16L1 gene might also contribute to the risk of psoriasis.

Promoter polymorphism -119C/G in MYG1 (C12orf10) gene is related to vitiligo susceptibility and Arg4Gln affects mitochondrial entrance of Myg1

BackgroundMYG1 (Melanocyte proliferating gene 1, also C12orf10 in human) is a ubiquitous nucleo-mitochondrial protein, involved in early developmental processes and in adult stress/illness conditions. We recently showed that MYG1 mRNA expression is elevated in the skin of vitiligo patients. Our aim was to examine nine known polymorphisms in the MYG1 gene, to investigate their functionality, and to study their association with vitiligo susceptibility.MethodsNine single nucleotide polymorphisms (SNPs) in the MYG1 locus were investigated by SNPlex assay and/or sequencing in vitiligo patients (n = 124) and controls (n = 325). MYG1 expression in skin biopsies was detected by quantitative-real time PCR (Q-RT-PCR) and polymorphisms were further analysed using luciferase and YFP reporters in the cell culture.ResultsControl subjects with -119G promoter allele (rs1465073) exhibited significantly higher MYG1 mRNA levels than controls with -119C allele (P = 0.01). Higher activity of -119G promoter was confirmed by luciferase assay. Single marker association analysis showed that the -119G allele was more frequent in vitiligo patients (47.1%) compared to controls (39.3%, P < 0.05, OR 1.37, 95%CI 1.02-1.85). Analysis based on the stage of progression of the vitiligo revealed that the increased frequency of -119G allele occurred prevalently in the group of patients with active vitiligo (n = 86) compared to the control group (48.2% versus 39.3%, P < 0.05; OR 1.44, 95%CI 1.02-2.03). Additionally, we showed that glutamine in the fourth position (in Arg4Gln polymorphism) completely eliminated mitochondrial entrance of YFP-tagged Myg1 protein in cell culture. The analysis of available EST, cDNA and genomic DNA sequences revealed that Myg1 4Gln allele is remarkably present in human populations but is never detected in homozygous state according to the HapMap database.ConclusionsOur study demonstrated that both MYG1 promoter polymorphism -119C/G and Arg4Gln polymorphism in the mitochondrial signal of Myg1 have a functional impact on the regulation of the MYG1 gene and promoter polymorphism (-119C/G) is related with suspectibility for actively progressing vitiligo.

Association analysis of genes of the IL19 cluster and their receptors in vitiligo patients.

The aim of the present study was to explore whether the genes encoding interleukin (IL) 19, IL-20, IL-24 and 2 chains of the IL-20 receptor type I (IL-20-RI), IL-20RA and IL-20RB, located on chromosomes 1q32, 6q22–23 and 3q22, respectively, are associated with vitiligo. The study involved 76 patients with vitiligo and 236 unrelated healthy volunteers. Genomic DNA was extracted from the whole blood and the frequencies of 20 single nucleotide polymorphisms were analysed by tetraprimer amplification refractory mutation system polymerase chain reaction. The minor allele of IL19 rs2243188 was significantly increased in vitiligo patients compared to controls (53.3 vs. 28.6%, adjusted p < 0.0001). The haplotype analysis revealed associations of 2 IL19/IL20 extended haplotypes (AACGTAA and ACCGTAA) and 2 IL20RB haplotypes (AGTA and AGGA) with vitiligo, remaining significant after correction for multiple testing. The A-to-C exchange at position IL19 rs2243188 leads to the loss of a nuclear receptor subfamily 2 factor binding site that is thought to influence mouse hippocampal development and neuronal differentiation. The third position of the IL20RB haplotypes is taken by rs747842 that induces the loss of the interferon regulatory factor 4 binding site that has an important role in the regulation of innate and adaptive immunity and in the signalling of pigmentation as well. In conclusion, the present study describes first-time associations between polymorphisms of genes of the IL19 cluster and their receptors and vitiligo, indicative of the part of IL19 and its receptor gene IL20RB in disease pathogenesis.

Further association analysis of chr 6q22-24 suggests a role of IL-20RA polymorphisms in psoriasis

In our previous studies we obtained evidence that the interleukin-19 (IL19) gene cluster and interleukin-20 receptor alpha (IL20RA) gene may represent susceptibility regions for psoriasis [1], [2], [3]. The aim of the present study was to scan an additional set of single nucleotide polymorphisms (SNPs) in the chromosomal region 6q22-24, which contains IL20RA, the genes for interleukin-22 receptor alpha 2 (IL22RA2) and interferon-gamma receptor 1 (IFNGR1) for association with psoriasis...

Analysis of genetic variants of class II cytokine and their receptor genes in psoriasis patients of two ethnic groups from the Volga-Ural region of Russia

BACKGROUND The molecular basis of pathogenesis of psoriasis remains unclear, but one unifying hypothesis of disease aetiology is the cytokine network model. The class II cytokines (CF2) and their receptors (CRF2) are all involved in the inflammatory processes and single nucleotide polymorphisms (SNPs) in respective genes have been associated with psoriasis in a previous study of the Estonian population. OBJECTIVE We performed a replication study of 47 SNPs in CF2 and CRF2 genes in independent cohorts of psoriasis patients of two ethnic groups (Russians and Bashkirs) from the Volga-Ural region of Russia. METHODS DNA was obtained from 395 psoriasis patients of two ethnic groups from the Volga-Ural region of Russia and 476 ethnically matched controls. 47 SNPs in the loci of the genes encoding Class II cytokines and their receptors were selected by SNPbrowser version 3.5. Genotyping was performed using the SNPlex™ (Applied Biosystems) platform. RESULTS The genetic variant rs30461 previously associated in original case-control study in Estonians, was also associated in Russians (corrected P-value (Pc=0.008, OR=0.44), but did not reach statistical significance in the Bashkir population. Additionally, the haplotype analysis provided that CC haplotype formed by the SNPs rs30461 and rs955155 had a protective effect in Russians (Pc=0.0024, OR=0.44), supporting the involvement of this locus in the protection against psoriasis. Combined meta-analysis of three populations, including 943 psoriasis patients and 812 healthy controls, showed that the IL29 rs30461 C-allele was not associated with decreased risk of psoriasis (P=0.165, OR=0.68). Moreover, stratification of studies by ethnicity revealed a significant association in the European cohort (P=9.506E-006, OR=0.53). CONCLUSION Therefore, there is no overall evidence of association between psoriasis and SNP rs30461 of the IL29 gene, but there is some evidence to suggest that an association exists in Europeans. However, this current concept should be considered as preliminary and the results need to be confirmed in future independent studies.

ATG16L1 gene polymorphisms are associated with palmoplantar pustulosis

Genes in autophagy pathway play an important role in innate and adaptive immunity. The aim of the study was to assess the impact of ATG16L1 gene on susceptibility of palmoplantar pustulosis. Four single nucleotide polymorphisms (SNPs) within the ATG16L1 region (rs2241880, rs2241879, rs7587633, and rs13005285) were genotyped in 241 control subjects and 38 palmoplantar pustulosis (PPP) patients of Estonian descent. The data analysis revealed a significantly higher frequency distribution of the rs2241880 G (odds ratio [OR] = 1.88, p = 0.0073) and rs2241879 A (OR = 1.87, p = 0.0079) allele in the PPP group when compared with the control group. The frequency distribution of the GACG haplotype was significantly higher (OR = 1.82, p = 0.016) in the PPP group when compared with the control group. The current study provides evidence of an association of the ATG16L1 gene in susceptibility to palmoplantar pustulosis, and supports the notion that the ATG16L1 gene as a member of the autophagy pathway most likely plays an important role in immune response.

Balanced reciprocal translocation t(5;13)(q33;q12) and 9q31.1 microduplication in a man suffering from infertility and pollinosis

We describe the first case of two chromosomal abnormalities, balanced reciprocal translocation t(5;13)(q33;q12.1) and a microduplication in the region 9q31.1, in a man suffering from infertility and pollinosis. In the region 13q12.1 is located the TUBA3C (tubulin, alpha 3c) gene, which plays an important dynamic role in the motility of flagella. This case might support the opinion that haploinsufficiency of the TUBA3C gene could be the cause of sperm immotility and abnormal sperm morphology, resulting in infertility in the patient. Single-nucleotide polymorphism (SNP) array analysis revealed a novel 9q31.1 microduplication inherited from both parents, which contributes to the genomic instability.