Non-Invasive Assessment of Skin Surface Proteins of Psoriasis Vulgaris Patients in Response to Biological Therapy

Measurements of skin surface biomarkers have enormous value for the detailed assessment of skin conditions, both for clinical application and in skin care. The main goals of the current study were to assess whether expression patterns of skin surface hBD-1, hBD-2, IL-1α, CXCL-1, and CXCL-8, examples of proteins known to be involved in psoriasis pathology, are associated with disease severity and whether expression patterns of these proteins on the skin surface can be used to measure pharmacodynamic effects of biological therapy. In this observational study using transdermal analysis patch (TAP), levels of skin surface IL-1α, hBD-1, hBD-2, CXCL-1/2, and CXCL-8 of psoriasis vulgaris (PV) patients over biological therapy were assessed. The Psoriasis Area Severity Index (PASI) and local score for erythema, induration, and desquamation were determined from the exact same skin area as FibroTx TAP measurements. Thirty-seven adult PV patients were included, of which twenty-three were subjected to anti-TNF-α, seven to anti-IL-17A, and seven to anti-IL12/IL-23 therapy. Significantly higher levels of hBD-1, hBD-2, CXCL-1/2, and CXCL-8 were detected on lesional skin compared to the non-lesional skin of the PV patients. In contrast, lower levels of IL-1α were found in lesional skin compared to non-lesional skin. In addition, we observed that the biomarker expression levels correlate with disease severity. Further, we confirmed that changes in the expression levels of skin surface biomarkers during biological therapy correlate with treatment response. Biomarker expression patterns in response to treatment differed somewhat between treatment subtypes. We observed that, in the case of anti-TNF-α therapy, an increase after a steady decrease in the expression levels of CXCL-1/2 and CXCL-8 occurred before the change in clinical scores. Moreover, response kinetics of skin surface proteins differs between the applied therapies-hBD2 expression responds quickly to anti-IL-17A therapy, CXCL-1/2 to anti-IL-12/23, and levels of CXCL-8 are rapidly down-regulated by IL-17A and IL-12/23 therapy. Our findings confirm that the skin surface hBD-2, IL-1α, CXCL-1/2, and CXCL-8 are markers for the psoriasis severity. Further, data obtained during this study give the basis for the conclusion that skin surface proteins CXCL-1/2 and CXCL-8 may have value as therapeutic biomarkers, thus confirming that measuring the 'molecular root' of inflammation appears to have value in scoring disease severity on its own.

Assessment of soluble skin surface protein levels for monitoring psoriasis vulgaris in adult psoriasis patients using non-invasive transdermal analysis patch: A pilot study

To improve the care of patients with chronic inflammatory skin conditions, such as psoriasis, there is a need for diagnostic methods that can facilitate personalized medicine. This exploratory pilot study aimed to determine whether non-invasive measurements of inflammation-related proteins from psoriatic skin can be sampled using the FibroTx Transdermal Analysis Patch (TAP) to assess disease severity and monitor pharmacodynamic changes. Ten healthy volunteers and 44 psoriasis vulgaris patients were enrolled in the exploratory pilot study. Skin surface protein measurements for healthy and lesional skin were performed using TAP. Patients' scores of psoriasis activity and severity (PASI) were documented, and differences in the thickness of skin layers were determined using sonography. The study assessed the skin surface protein levels of psoriasis patients undergoing whole-body treatment with narrow-band UVB to evaluate whether the levels of the skin surface proteins IL-1α, IL-1RA CXCL-1/2, and hBD-1 were associated with the disease activity and severity measurements. Using TAP technology, it was observed that there were clear differences in levels of IL-1α, IL-1RA, CXCL-1/2, and hBD-1 between psoriasis lesional and non-lesional skin. In addition, a positive correlation between CXCL-1/2 and desquamation, and between CXCL-1/2 and SLEB thickness was observed. During UVB treatment, the TAP measurements revealed a clear reduction of IL-1RA, CXCL 1/2, and hBD-1 on lesional skin. Further, skin surface measurements of IL-1RA and CXCL-1/2 displayed a different profile than those achieved by visual scoring of local inflammation, thus indicating that measuring the 'molecular root' of inflammation appears to have value as an objective, non-invasive biomarker measurement for scoring disease severity.

Polymorphisms in IL36G gene are associated with plaque psoriasis

Background

Plaque psoriasis is a non-contagious skin disease in which characteristic red and flaky lesions result from a dysregulation involving both innate and adaptive immune mechanisms. Several cytokines have been implicated in these processes and lately interleukin (IL)-36 family members have become more recognised among them. Thus far, genetic studies have only investigated IL36RN gene of this family in relation to pustular psoriasis. Since IL36G has previously demonstrated markedly increased levels in plaque psoriasis patients and is linked to IL-23/IL-17 axis critical in psoriasis pathology, it was chosen to be the focus of current report.

Methods

Eleven SNPs from IL36G region were genotyped in 728 plaque psoriasis patients and 320 healthy control individuals. Allele and haplotype frequencies between patients and controls were assessed by respective association tests. For more specific analyses, the patients were assigned into subgroups according to sex, age of disease onset, occurrence of psoriasis among relatives, seasonal aggravation, arthritis symptoms, body surface area (BSA) scores, and Psoriasis Area and Severity Index (PASI) scores.

Results

The most significant results were obtained with SNPs rs28947206, rs28947207 and rs28947211 that were associated in entire plaque psoriasis analysis (multiple testing adjusted p value (p_adj) = 0.0054, p_adj = 0.0017 and p_adj = 0.0001) and also several subgroups. The first two of those SNPs were included in the same haplotype block with rs28947205 and rs12328178, and two of the respective haplotypes, CAGC and TGTT, provided similarly significant associations (p_adj = 0.0462 and p_adj = 0.0047).

Conclusions

The associated SNPs of this study or those in linkage disequilibrium with them could potentially affect the functionality of IL-36γ cytokine, which in turn may impact plaque psoriasis pathology. For instance, these variants could influence IL-36γ expression or 3D structure, thereby altering its ability to induce chemokine production in keratinocytes and various immune cells. The precise mechanisms of these actions are currently unknown and out of the scope of this study. To conclude, the present genetic association results confirm the proposed role of IL-36γ in plaque psoriasis development, with corresponding causal effects to be determined in forthcoming research.

Lymphoid Stress Surveillance Response Contributes to Vitiligo Pathogenesis

Vitiligo is a chronic multifactorial depigmentation disorder characterized by the destruction and functional loss of melanocytes. Although a direct cytotoxic T cell attack is thought to be responsible for melanocyte damage, the events leading to the loss of self-tolerance toward melanocytic antigens are not understood. This research aimed to identify novel cellular and molecular factors that participate in vitiligo pathogenesis through the application of gene expression and immunofluorescence analysis of skin biopsy samples along with immunophenotyping of circulating cells. Our study provides insights into the mechanisms involved in melanocyte destruction. The upregulation of stress-ligand MICA/MICB, recognized by activating receptors on innate and innate-like T cells, imply involvement of lymphoid stress surveillance responses in vitiligo lesions. A simultaneous increase in the expression of transcription factor EOMES that is characteristic for innate-like virtual memory T cells, suggest a similar scenario. Local lymphoid stress surveillance has been previously associated with the amplification of systemic humoral responses that were mirrored in our study by increased T follicular helper cells and switched memory B cell proportions in patients with active vitiligo. In addition, microtubule-associated protein light chain 3 staining was compatible with the activation of autophagy in keratinocytes and in the remaining melanocytes of vitiligo lesional skin.

miR-146b Probably Assists miRNA-146a in the Suppression of Keratinocyte Proliferation and Inflammatory Responses in Psoriasis

miR-146a inhibits inflammatory responses in human keratinocytes and in different mouse models of skin inflammation. Little is known about the role of miR-146b in the skin. In this study, we confirmed the increased expression of miR-146a and miR-146b (miR-146a/b) in the lesional skin of patients with psoriasis. The expression of miR-146a was approximately twofold higher than that of miR-146b in healthy human skin, and it was more strongly induced by stimulation of proinflammatory cytokines in keratinocytes and fibroblasts. miR-146a/b target genes regulating inflammatory responses or proliferation were altered in the skin of patients with psoriasis, among which FERMT1 was verified as a direct target of miR-146a. In silico analysis of genome-wide data from >4,000 psoriasis cases and >8,000 controls confirmed a moderate association between psoriasis and genetic variants in the miR-146a encoding gene. Transfection of miR-146a/b suppressed and inhibition enhanced keratinocyte proliferation and the expression of psoriasis-related target genes. Enhanced expression of miR-146a/b-influenced genes was detected in cultured keratinocytes from miR-146a-/- and skin fibroblasts from miR-146a-/- and miR-146b-/- mice stimulated with psoriasis-associated cytokines as compared with wild-type mice. Our results indicate that besides miR-146a, miR-146b is expressed and might be capable of modulation of inflammatory responses and keratinocyte proliferation in psoriatic skin.

Genome-wide association studies of autoimmune vitiligo identify 23 new risk loci and highlight key pathways and regulatory variants

Vitiligo is an autoimmune disease in which depigmented skin results from destruction of melanocytes¹, with epidemiologic association with other autoimmune diseases². In previous linkage and genome-wide association studies (GWAS1, GWAS2), we identified 27 vitiligo susceptibility loci in patients of European (EUR) ancestry. We carried out a third GWAS (GWAS3) in EUR subjects, with augmented GWAS1 and GWAS2 controls, genome-wide imputation, and meta-analysis of all three GWAS, followed by an independent replication. The combined analyses, with 4,680 cases and 39,586 controls, identified 23 new loci and 7 suggestive loci, most encoding immune and apoptotic regulators, some also associated with other autoimmune diseases, as well as several melanocyte regulators. Bioinformatic analyses indicate a predominance of causal regulatory variation, some corresponding to eQTL at these loci. Together, the identified genes provide a framework for vitiligo genetic architecture and pathobiology, highlight relationships to other autoimmune diseases and melanoma, and offer potential targets for treatment.

MicroRNA-155 is Dysregulated in the Skin of Patients with Vitiligo and Inhibits Melanogenesis-associated Genes in Melanocytes and Keratinocytes

Little is known about the functions of microRNAs (miRNAs) in skin pigmentation disorders. The aim of this study was to investigate the expression and potential role of miRNAs in vitiligo. Of 12 studied miRNAs with proven functions in cell proliferation, differentiation, immune responses and melanogenesis, miR-99b, miR-125b, miR-155 and miR-199a-3p were found to be increased and miR-145 was found to be decreased in the skin of patients with vitiligo. Combined pathway and target analysis revealed melanogenesis-associated targets for miR-99b, miR-125b, miR-155 and miR-199a-3p. In situ hybridization analysis demonstrated increased expression of miR-155 in the epidermis of patients with vitiligo. Correspondingly, miR-155 was induced by vitiligo-associated cytokines in human primary melanocytes and keratinocytes. When overexpressed, miR-155 inhibited the expression of melanogenesis-associated genes and altered interferon-regulated genes in melanocytes and keratinocytes. In conclusion, this study demonstrates that the expression of miRNAs is dysregulated in the skin of patients with vitiligo and suggests that miR-155 contributes to the pathogenesis of vitiligo.

Association analysis of class II cytokine and receptor genes in vitiligo patients

The loss of melanocytes in vitiligo is mainly attributed to defective autoimmune mechanisms and lately autoinflammatory mediators have become more emphasized. Among these, a number of class II cytokines and their receptors have displayed altered expression patterns in vitiligo. Thus, we selected 30 SNPs from the regions of respective genes to be genotyped in Estonian case-control sample (109 and 328 individuals, respectively). For more precise analyses, patients were divided into subgroups based on vitiligo progression activity, age of onset, sex, occurrence of vitiligo among relatives, extent of depigmented areas, appearance of Köbner's phenomenon, existence of halo nevi, occurrence of spontaneous repigmentation, and amount of thyroid peroxidase antibodies. No associations appeared in whole vitiligo group. In subgroups, several allelic and haplotype associations were found. The strongest involved SNPs rs12301088 (near IL26 gene), that was associated with familial vitiligo and existence of halo nevi, and rs2257167 (IFNAR1 gene), that was associated with female vitiligo. Additionally, haplotypes consisting of rs12301088 and rs12321603 alleles (IL26-IL22 genes), that were associated with familial vitiligo and existence of halo nevi. In conclusion, several genetic associations with vitiligo subphenotypes were revealed and functional explanations to these remain to be determined in respective studies.

Polymorphisms in Toll-like receptor genes are associated with vitiligo

Background: The members of Toll-like receptor (TLR) family are responsible for recognizing various molecular patterns associated with pathogens. Their expression is not confined to immune cells and have been detected in skin cells such as keratinocytes and melanocytes. As part of a generated response to pathogens, TLRs are involved in inducing inflammatory mediators to combat these threats. It is therefore not surprising that TLRs have been implicated in inflammatory skin diseases, including atopic dermatitis and psoriasis. Likewise, as key players in autoimmunity, they have been associated with a number of autoimmune diseases. Based on this, the role of TLRs in vitiligo could be suspected, but is yet to be clearly established.

Methods: In order to conduct a genetic association analysis, 30 SNPs were selected from TLR1-TLR8 and TLR10 regions to be genotyped in Estonian case-control cohort consisting of 139 vitiligo patients and 307 healthy control individuals. The patients were further analyzed in subgroups based on sex, age of onset, occurrence of vitiligo among relatives, extent of depigmented areas, vitiligo progression activity, appearance of Köbner's phenomenon, existence of halo naevi, and incidence of spontaneous repigmentation.

Results: The most notable finding came with SNP rs179020 situated in TLR7 gene, that was associated in entire vitiligo (Padj = 0.0065) and also several subgroup analyses. Other single marker and haplotype analyses pointed to TLR3, TLR4, and TLR10 genes.

Conclusions: This study investigated the genetic regions of nine TLR genes in relation to vitiligo susceptibility. The main results were the associations of TLR7 SNPs with vitiligo, while several other associations were obtained from the remaining TLR gene regions. This suggests that in addition to other inflammatory skin diseases, TLRs affect the development of vitiligo, thus making them interesting targets for future research.

Whole Transcriptome Analysis (RNA Sequencing) of Peripheral Blood Mononuclear Cells of Vitiligo Patients

Vitiligo is an idiopathic disorder characterized by depigmented patches on the skin due to a loss of melanocytes. The cause of melanocyte destruction is not fully understood. The aim of this study was to detect the potential pathways involved in the vitiligo pathogenesis to further understand the causes and entity of vitiligo. For that the transcriptome of peripheral blood mononuclear cells of 4 vitiligo patients and 4 control subjects was analyzed using the SOLiD System platform and whole transcriptome RNA sequencing application. Altogether 2,470 genes were expressed differently and GRID2IP showed the highest deviation in patients compared to controls. Using functional analysis, altogether 993 associations between the gene groups and diseases were found. The analysis revealed associations between vitiligo and diseases such as lichen planus, limb-girdle muscular dystrophy type 2B, and facioscapulohumeral muscular dystrophy. Additionally, the gene groups with an altered expression pattern are participating in processes such as cell death, survival and signaling, inflammation, and oxidative stress. In conclusion, vitiligo is rather a systemic than a local skin disease; the findings from an enormous amount of RNA sequencing data support the previous findings about vitiligo and should be further analyzed.

Quality of life and emotional state in vitiligo in an Estonian sample: comparison with psoriasis and healthy controls

The impact of vitiligo on quality of life is controversial. The aim of this study was to observe the impairment of quality of life and emotional state in adults with vitiligo compared with subjects with psoriasis and unaffected controls. The study group comprised 54 subjects with vitiligo, 57 with psoriasis and 57 unaffected controls. All subjects were examined and interviewed using the Dermatology Life Quality Index (DLQI) and Emotional State questionnaires. The total mean DLQI score in vitiligo was 4.7, compared with 0.6 in healthy controls (p<0.001) and 13.1 in psoriasis (p<0.001). In vitiligo, females experienced a greater impact on feelings and men experienced a greater impact on relationships. Lower quality of life in vitiligo was associated with active stage of the disease, extension of pigment loss, depigmentation on the hands, and earlier onset of disease. The results demonstrate that vitiligo has less impact on quality of life than psoriasis.

Expression profile of genes associated with the dopamine pathway in vitiligo skin biopsies and blood sera

BACKGROUND

Dopamine has been proven to be toxic for melanocytes. In vitiligo patients the level of dopamine is increased and the functioning of several enzymes participating in the dopamine pathway is changed.

METHODS

With the use of quantitative real-time polymerase chain reaction and ELISA the expression of genes connected to the dopamine pathway (PAH, PCD, TH, DDC, DBH, PNMT, GPX1, MAOA, MAOB, COMT, DRD1-DRD5, VMAT1 and VMAT2) was observed in vitiligo patients' and control subjects' skin and blood.

RESULTS

The mRNA expression of GPX1, DDC, MAOA, DRD1 and DRD5 differs in vitiligo skin and the protein level of DDC, MAOA, MAOB, DRD1 and DRD5 is changed in vitiligo patients' skin and/or blood sera.

CONCLUSIONS

The dopamine pathway probably influences melanogenesis directly or through the melanocortin pathway. We provide new data about changes of expression profile of the dopamine-synthesizing enzyme DDC, the dopamine-degrading enzymes MAOA and MAOB and the D1-like family dopamine receptors in vitiligo skin and blood sera.

Mechanisms of IFN-γ-induced apoptosis of human skin keratinocytes in patients with atopic dermatitis

BACKGROUND

Enhanced apoptosis of keratinocytes is the main cause of eczema and spongiosis in patients with the common inflammatory skin disease atopic dermatitis (AD).

OBJECTIVE

The aim of the study was to investigate molecular mechanisms of AD-related apoptosis of keratinocytes.

METHODS

Primary keratinocytes isolated from patients with AD and healthy donors were used to study apoptosis by using annexin V/7-aminoactinomycin D staining. Illumina mRNA Expression BeadChips, quantitative RT-PCR, and immunofluorescence were used to study gene expression. In silico analysis of candidate genes was performed on genome-wide single nucleotide polymorphism data.

RESULTS

We demonstrate that keratinocytes of patients with AD exhibit increased IFN-γ-induced apoptosis compared with keratinocytes from healthy subjects. Further mRNA expression analyses revealed differential expression of apoptosis-related genes in AD keratinocytes and skin and the upregulation of immune system-related genes in skin biopsy specimens of chronic AD lesions. Three apoptosis-related genes (NOD2, DUSP1, and ADM) and 8 genes overexpressed in AD skin lesions (CCDC109B, CCL5, CCL8, IFI35, LYN, RAB31, IFITM1, and IFITM2) were induced by IFN-γ in primary keratinocytes. The protein expression of IFITM1, CCL5, and CCL8 was verified in AD skin. In line with the functional studies and AD-related mRNA expression changes, in silico analysis of genome-wide single nucleotide polymorphism data revealed evidence of an association between AD and genetic markers close to or within the IFITM cluster or RAB31, DUSP1, and ADM genes.

CONCLUSION

Our results demonstrate increased IFN-γ responses in skin of patients with AD and suggest involvement of multiple new apoptosis- and inflammation-related factors in the development of AD.

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.

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

Background

MYG1 (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.

Methods

Nine 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.

Results

Control 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.

Conclusions

Our 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.

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.

OBJECTIVES

To evaluate potential roles of IL10 family cytokines (IL10, IL19, IL20, IL22 and IL24) in vitiligo. Along with the selected cytokines, we investigated subunits of the receptors (IL10RA, IL10RB, IL20RA and IL22RA1) which are involved in the signalling pathway of the cytokines.

METHODS

Quantitative real-time polymerase chain reaction was used to detect mRNA expression levels in samples extracted from skin biopsies and peripheral blood mononuclear cells and an enzyme-linked immunosorbent assay was used to measure protein concentrations in serum from patients with vitiligo and healthy controls.

RESULTS

IL22 is significantly associated with vitiligo, especially with the active stage of vitiligo, as shown by results of mRNA expression and supported by results of protein level in sera. IL22 may provoke inflammation which leads to destruction of melanocytes.

CONCLUSIONS

The actual role of IL22 during pathogenesis of vitiligo remains to be better characterized. Signal transductions of other investigated cytokines seem to be regulated on the expression level of their receptor complex subunits.

Gene expression analysis of melanocortin system in vitiligo

BACKGROUND

The melanocortin system in the skin coordinates pigmentation and immune response and could be implicated in the pathogenesis of vitiligo.

OBJECTIVES

We aimed to analyze changes in expression of genes involved in skin pigmentation (melanocortin system and enzymes involved in melanin synthesis).

METHODS

With quantitative RT-PCR we measured the mRNA expression levels of eight genes from the melanocortin system and two enzymes involved in melanogenesis. RNA was extracted from both lesional and non-lesional skin of vitiligo patients and in non-sun-exposed skin of healthy subjects.

RESULTS

POMC (proopiomelanocortin) expression was lower in lesional skin compared to non-lesional skin. Expression of melanocortin receptors was increased in unaffected skin of vitiligo patients compared to healthy subjects and decreased in lesional skin compared to uninvolved skin of vitiligo patients, the differences were statistically significant in the cases of MC1R (melanocortin receptor 1) and MC4R (melanocortin receptor 4). TRP1 and DCT genes were down-regulated in lesional skin compared to non-lesional vitiligo skin or skin of healthy controls and up-regulated in uninvolved vitiligo skin compared to healthy control samples. In non-lesional skin, POMC expression was not elevated, possibly indicating that systemic influences are involved in up-regulation of MC receptor genes. Decreased expression of the analyzed genes in the lesional skin is not surprising, but statistically significant increased expression of studied genes in non-lesional skin from vitiligo patients is not described previously.

CONCLUSION

In our mind, up-regulation of melanocortin system in non-lesional skin could be systemic compensation to restore normal pigmentation in lesions.

Possible relations between the polymorphisms of the cytokines IL-19, IL-20 and IL-24 and plaque-type psoriasis

The aim of present study was to elucidate the role of the interleukin (IL)-24 gene in predicting risk for plaque-type psoriasis and to describe the linkage disequilibrium (LD) pattern emerging from the genes of IL-19, IL-20 and IL-24. Genes encoding IL-19, IL-20 and IL-24 locate in the region q32 of chromosome 1. The association between the single-nucleotide polymorphisms (SNPs) or haplotypes of the IL-24 gene and the susceptibility of psoriasis was not found. However, a significant protective effect of the combined haplotype CAAAC of IL-20 and IL-24 genes against plaque-type psoriasis was established (OR 0.154). Protective effect against psoriasis was also observed with haplotype TGGGT (OR 0.591) and haplotype CGAGT (OR 0.457). Performing a comprehensive analysis using the data regarding SNPs of IL-24 gene together with the previously published data regarding IL-19 and IL-20 SNPs, we identified two haplotype blocks within the region q32 of chromosome 1. The main result of the present study is that while the IL-19/IL-20 extended haplotype CACCGGAA is a significant susceptibility factor for psoriasis (previous study), IL-20/IL-24 haplotypes CAAAC, TGGGT and CGAGT have a significant protective effect. Nevertheless, family-based studies are required to confirm the impact of IL-19, IL-20 and IL-24 genes in the genetic predisposition for psoriasis.

Combined haplotype analysis of the interleukin-19 and -20 genes: relationship to plaque-type psoriasis

There is increasing evidence to suggest that the newly discovered cytokines interleukin (IL)-19 and -20 have a role in the function of epidermis and in psoriasis. The genes encoding these cytokines locate into the genomic IL-10 region on human chromosome 1. The aim of the present study was to analyze whether single-nucleotide polymorphisms (SNPs) in these genes have an impact on the susceptibility for psoriasis. From pairwise linkage disequilibrium (LD) matrix of the IL-19 and -20 gene polymorphisms, what reflects the nonrandom association of alleles at these markers, it was apparent that IL-19 and -20 genes form one block of LD. We found that the HT3 CACCGGAA haplotype of the IL-19 and -20 genes was associated with an increased risk of psoriasis, reflecting its role in determining susceptibility to plaque-type psoriasis. Although association analysis of the IL-19 gene indicated that minor alleles of the IL-19 gene SNPs (rs2243188, rs2243169 and rs2243158) revealed protective effect to psoriasis and haplotype analysis of the IL-19 gene proved significant protective effect of the TGATA haplotype in case of late-onset disease, combined haplotype analysis of the IL-19 and -20 genes demonstrated that protective effect of the IL-19 gene is secondary to the susceptibility effect of the IL-20 gene.

Terbinafine: efficacy and tolerability in young children with tinea capitis due to Microsporum canis

AIMS

We carried out an open, prospective, uncontrolled study to evaluate the efficacy and tolerability of terbinafine in the treatment of young children with tinea capitis due to Microsporum canis.

METHODS

A total of 83 healthy, immunocompetent children (age range 2-13 years) were enrolled in eight centres in Estonia, Latvia and Lithuania. Patients received oral terbinafine in dosages based on weight, 62.5 mg for those weighing 10-20 kg, 125 mg for 20-40 kg, plus application of topical 1% terbinafine cream twice daily to affected areas. Treatment lasted for 4 weeks, followed by an 8-week observation (treatment-free) period. All the subjects were assessed for efficacy and tolerability at 12 weeks.

RESULTS

Eighty-one subjects were available for assessment at 12 weeks: 32 had completely recovered, with no evidence of relapse during the observation period, and 21 showed mycological cure, but presented residual physical signs of infection. Thus the effective cure rate was 65.4% in an infection known to be more difficult to cure than other causes of tinea capitis. Terbinafine was well tolerated by these children.

CONCLUSIONS

This study showed effective cure of two-thirds of 81 cases of tinea capitis caused by M. canis with a 4-week course of treatment. As one-third of the cases did not respond to treatment, we suggest using combined oral and topical treatment with terbinafine in children with tinea capitis caused by M. canis.

QSPR analysis of flash points

A quantitative structure property relationship study of the flash point of a diverse set of 271 compounds provided a general three-parameter QSPR model (R(2) = 0.9020, R(2)(cv) = 0.8985, s = 16.1). Use of the experimental boiling point as a descriptor gives a three-descriptor equation with R(2) = 0.9529. Use of the boiling point predicted by a four-parameter reported relationship gives a three-parameter flash point equation with a R(2) value of 0.9247.

Interpretation of quantitative structure-property and -activity relationships

The potential utility of data reduction methods (e.g. principal component analysis) for the analysis of matrices assembled from the related properties of large sets of compounds is discussed by reference to results obtained from solvent polarity scales, ongoing work on solubilities and sweetness properties, and proposed general treatments of toxicities and gas chromatographic retention indices.

QSRR correlation of free-radical polymerization chain-transfer constants for styrene

Quantitative structure-reactivity relationships (QSRR) are deduced for kinetic chain-transfer constants for 90 agents on styrene polymerization at 60 degrees C. Three- and five-parameter correlations were obtained with R2 of 0.725 and 0.818, respectively. The descriptors involved in the correlations are consistent with the proposed mechanism of the chain-transfer reactions.

A QSPR model for the prediction of the gas-phase free energies of activation of rotation around the N-C(O) bond

A novel approach to predict the gas-phase rotational activation energies of amides is presented. The quantitative structure property relationship (QSPR) treatment, using the statistical package, comprehensive descriptors for structural and statistical analysis (CODESSA), resulted in a three-parameter equation with R2 = 0.982 for the deltaG(double dagger)gas, of a set of 24 N,N-dialkylamides.

Relevance of theoretical molecular descriptors in quantitative structure-activity relationship analysis of alpha1-adrenergic receptor antagonists

A quantitative structure-activity relationship (QSAR) study of a wide series of structurally diverse alpha1-adrenergic receptor antagonists was performed using the CODESSA (Comprehensive Descriptors for Structural and Statistical Analysis) technique. Theoretical descriptors derived on a single structure and ad hoc defined size and shape descriptors were considered in the attempt of describing information relevant to receptor interaction. The relative effectiveness of these two classes of parameters in developing QSAR models for native (alpha1A and alpha1B) and cloned (alpha1a, alpha1b, and alpha1d) adrenergic receptor binding affinity, functional activity of vascular and lower urinary tract tissues, and in vitro and in vivo selectivity was evaluated.

Theoretical descriptors in quantitative structure-affinity and selectivity relationship study of potent N4-substituted arylpiperazine 5-HT1A receptor antagonists

The ability of ad hoc defined size and shape descriptors and theoretical descriptors derived on a single structure to give powerful interpretative and predictive QSAR models has been compared and evaluated with respect to the quality of the pharmacological data available for a series of structurally diverse 5-HT1A receptor antagonists, displaying selectivity towards the alpha 1-adrenergic receptor.

Prediction of Critical Micelle Concentration Using a Quantitative Structure-Property Relationship Approach

Relationships between the molecular structure and the critical micelle concentration (cmc) of anionic surfactants were investigated using a quantitative structure-property relationship approach. Measured cmc values for 119 anionic structures, representing sodium alkyl sulfates and sodium sulfonates with a wide variety of hydrophobic and hydrophilic structures, were considered. The best multiple linear regression model involved three terms (descriptors) and had a correlation coefficient of R2 = 0.940. Very good correlations (R2 = 0.988) were obtained using three descriptors for a subset of 68 structures, with structural variation only in the hydrophobic domain. From the descriptors used in these regressions, one can conclude that the cmc is primarily dependent on the size (volume or surface area) of the hydrophobic domain and to a lesser extent on the structural complexity of the surfactant molecule.

Electron impact ionization mass spectrometry and intramolecular cyclization in 2-substituted pyrimidin-4(3H)-ones

Electron impact ionization mass spectrometry indicates that the behavior of W-unsubstituted pyrirnidin-4-ones with CH2-R type substitution at C-2 differs from homologs that are N-substituted and/or 2-aryl- or 2-methyl-substituted. A dominant intramolecular cycliza-tion was found to occur between 3ZV (in agreement with the predominance of the 3NH tautomers) and the ortho positions of the aryl moiety in compounds with a CH2-aryl substitution at C-2. Theoretical calculations with an AMI SCFR method on 2-, 6-, and 2, 6-disubstituted pyrimidin-4-ones support the mass spectrometric observations.