Identification of LCK mutation in a family with atypical epidermodysplasia verruciformis with T-cell defects and virus-induced squamous cell carcinoma.

BACKGROUND: Inherited epidermodysplasia verruciformis (EV) is a rare skin disorder characterized by susceptibility to specific types of human papilloma virus (HPV) and is strongly associated with skin carcinomas. Inactivating mutations in EVER1/EVER2 account for most cases of EV. However, more phenotypes related to but distinct from EV have been reported with an immunodeficiency state but without EVER1/EVER2 mutation, and the genetic basis for these atypical EV cases is poorly understood. OBJECTIVES: To identify the causative gene responsible for three siblings affected by atypical EV but without EVER1/EVER2 mutation. METHODS: Whole-exome sequencing followed by Sanger sequencing was performed to identify the gene responsible for the patients with atypical EV enrolled in our study. RESULTS: A homozygous splicing mutation was detected in LCK (c.188-2A>G). This mutation resulted in an exon 3 deletion T lymphocyte-specific protein tyrosine kinase isoform, which further led to frameshift mutation and subsequent mRNA decay. CONCLUSIONS: We demonstrate a novel mutation in LCK in a family affected by atypical EV with T-cell defects, HPV infection and virus-induced malignancy, providing new clues in the understanding of host defences against HPV and better genetic counselling of patients with the EV phenotype.

A functional single-nucleotide polymorphism in the ERCC1 gene alters the efficacy of narrowband ultraviolet B therapy in patients with active vitiligo in a Chinese population.

BACKGROUND: T lymphocytes have been shown to cause the destruction of melanocytes in vitiligo pathogenesis. Narrowband ultraviolet B (NB-UVB), as an effective therapeutic strategy in vitiligo, can lead to the formation of DNA photoproducts such as cyclobutane pyrimidine dimers (CPDs) in perilesional lymphocytes and thus induce skin immunosuppression. The repair of DNA photoproducts is performed mainly through the nucleotide excision repair (NER) pathway. We hypothesized that single-nucleotide polymorphisms (SNPs) in NER genes might influence the repair capacity of CPDs and thus contribute to variations in phototherapy efficiency. OBJECTIVES: To detect genetic polymorphisms in NER genes and their relationship with the efficacy of NB-UVB therapy in patients with active vitiligo. METHODS: We investigated the association of NER SNPs (XPA A23G, XPC Ci11A, XPC C2919A and ERCC1 C118T) with phototherapy efficacy in 86 patients with vitiligo who received NB-UVB treatment. Furthermore, we examined the impact of ERCC1 C118T on the apoptosis of T lymphocytes and CPD accumulation after NB-UVB irradiation. RESULTS: We found that patients with vitiligo with the ERCC1 codon 118 CC genotype showed better efficacy after NB-UVB irradiation than those with the ERCC1 118 TT and CT genotypes, whereas no such association was documented among the genotypes of XPA A23G, XPC Ci11A or XPC C2919A. Additionally, the apoptosis rates and CPD levels of lymphocytes after NB-UVB irradiation in patients with the ERCC1 118 CC genotype were significantly higher than those in patients with the ERCC1 118 TT and CT genotypes. CONCLUSIONS: The ERCC1 118 CC genotype confers better efficacy of NB-UVB therapy in patients with active vitiligo.

miR-196a-2 rs11614913 polymorphism is associated with vitiligo by affecting heterodimeric molecular complexes of Tyr and Tyrp1.

Tyrosinase and tyrosinase-related protein 1 (Tyr-Tyrp1) complex plays a critical role in the synthesis of melanin intermediates, which involves the production of reactive oxygen species (ROS) and contributes to the development of vitiligo. Based on our previous observation that rs11614913 single nucleotide polymorphism (SNP) in miR-196a-2 could affect the risk of vitiligo by influencing Tyrp1, we hypothesized that the same SNP could also regulate the level of Tyr in vitiligo. The aim of this study was to evaluate the potential association between rs11614913 SNP in miR-196a-2 and serum Tyr level in vitiligo and the regulatory role of miR-196a-2 in the expression of Tyr in melanocytes. The serum Tyr level was detected in 116 patients with vitiligo and 116 controls by ELISA plate assay. The expression level of Tyrp1 and Tyr in PIG1(normal melanocyte cell lines) cells was analyzed by western blotting. The ROS level and apoptosis rate in PIG1 cells transfected with si-Tyr or control siRNA were tested by flow cytometry. The results show that the individuals with TT+TC genotypes in miR-196a-2 and higher Tyr level in serum had an increased risk of vitiligo compared with those who had the CC genotype and lower Tyr level (P < 0.001). Furthermore, the rs11614913 C allele in miR-196a-2 enhanced its inhibitory regulation on the expression of Tyr, the down-regulation of which in melanocytes successfully reduced the intracellular ROS levels and the apoptosis rate. In conclusion, our findings suggest that miR-196a-2 polymorphisms can regulate the Tyr levels, which influences the susceptibility of vitiligo.

Genetic polymorphisms in the methylenetetrahydrofolate reductase gene (MTHFR) and risk of vitiligo in Han Chinese populations: a genotype-phenotype correlation study.

BACKGROUND: Recent evidence has revealed an elevation of total homocysteine (tHcy) in patients with vitiligo. Methylenetetrahydrofolate reductase (MTHFR) is one of the main enzymes regulating homocysteine (Hcy) metabolism. Thus, polymorphisms of MTHFR could potentially contribute to the development of vitiligo by affecting MTHFR activity and tHcy levels. OBJECTIVES: To evaluate the potential association between MTHFR polymorphisms and vitiligo susceptibility. METHODS: In total, 1000 patients with vitiligo and 1000 age- and sex-matched controls were enrolled in this hospital-based case-control study. Two single-nucleotide polymorphisms of the MTHFR gene (rs1801133 C>T and rs1801131 A>C) were selected and genotyped using polymerase chain reaction (PCR)-restriction fragment length polymorphism and allele-specific PCR, respectively. The MTHFR activity concentration and tHcy level in serum were measured by enzyme-linked immunosorbent assay. RESULTS: We found that allele T of rs1801133 in the MTHFR gene was associated with a significantly reduced risk of vitiligo (adjusted odds ratio 0·58, 95% confidence interval 0·43-0·76, P < 0·001). In addition, the patients with vitiligo had a lower activity concentration of MTHFR and higher level of tHcy than the controls. Correlation between these markers and the risk of vitiligo was also observed. Furthermore, the individuals with a no-risk genotype (CT + TT) of rs1801133 and higher activity concentration of MTHFR or lower level of tHcy had a significantly decreased risk of vitiligo. CONCLUSIONS: Our data suggest that MTHFR gene polymorphisms may play a vital role in genetic susceptibility to vitiligo.

The association between trauma and melanoma in the Chinese population: a retrospective study.

BACKGROUND: The association between trauma and melanoma has been a controversial issue. OBJECTIVES: To analyse the profiles of melanoma, and to determine whether trauma is associated with development of acral melanoma in the Chinese population. PATIENTS AND METHODS: Retrospective analysis of 685 cases of cutaneous melanoma in the dermatology departments of Xijing Hospital in northwestern China and Xinan Hospital in southwestern China from 1982 to 2011. RESULTS: Of the 685 patients included in the study, 437 (63.8%) suffered from melanoma on the extremities. A total of 104 patients (15.2%) exhibited an association between trauma and melanoma. The primary anatomic sites of the tumours were the upper extremities (17, 16.3%), lower extremities (74, 71.2%) and other sites (13, 12.5%). Among these cases, the extremities were with remarkably higher risks of post-trauma melanoma than the other sites [adjusted odds ratio (OR) 3.968; 95% confidence interval (CI) 2.267-5.592]. Notably, patients in the south part of China were with a stronger risk of post-trauma melanoma on the lower extremities than those in the north (adjusted OR 1.764; 95% CI 1.192-2.666) part. In addition, a significant higher risk of post-trauma melanoma on the extremities was observed in the male gender (adjusted OR 1.848; 95% CI 1.186-2.887). CONCLUSIONS: Our findings provide epidemiological evidence for a potential association between traumatic events and melanoma of the extremities, especially the lower limbs, where a history of trauma is more likely.

Association between FOXP3 polymorphisms and vitiligo in a Han Chinese population.

BACKGROUND: Vitiligo is an autoimmune chronic depigmentation disorder caused by melanocyte loss. Previous studies found that CD4(+)CD25(+) regulatory T-cell (Treg) dysfunction was involved in the pathogenesis of vitiligo and that gene polymorphisms in forkhead box P3 (FOXP3) - a master regulator of Treg development and function - were associated with susceptibility to some autoimmune disorders. Therefore, we hypothesized that functional polymorphisms of the FOXP3 gene might be associated with vitiligo via dysregulation of Treg cells. OBJECTIVES: To evaluate whether FOXP3 polymorphisms are associated with vitiligo risk. MATERIAL AND METHODS: In this hospital-based case-control study of 682 patients with vitiligo and 682 vitiligo-free age- and sex-matched controls, we genotyped three single nucleotide polymorphisms (SNPs) of the FOXP3 gene - rs2232365, rs3761548 and rs5902434 - by performing polymerase chain reaction with sequence-specific primers (PCR-SSP). RESULTS: Significantly increased vitiligo risk was associated with the rs2232365 GG [odds ratio (OR) 1·68, 95% confidence interval (CI) 1·17-2·39, P = 0·004] and rs3761548 AA (OR 1·82, 95% CI 1·10-3·01, P = 0·033) genotypes compared with the rs2232365 AA and rs3761548 CC genotypes. On combined analysis of these three variant alleles, we found that individuals carrying 2-6 variant alleles had significantly increased vitiligo risk (OR 1·34, 95% CI 1·08-1·66). This risk was more pronounced in the following subgroups: age > 20 years, male sex, active vitiligo, nonsegmental vitiligo and other accompanying autoimmune diseases. CONCLUSIONS: FOXP3 gene polymorphisms contributed to vitiligo risk in a Han Chinese population.

The association of vitamin D receptor gene polymorphisms and serum 25-hydroxyvitamin D levels with generalized vitiligo.

BACKGROUND: Vitiligo is an acquired depigmentation autoimmune disorder that has been described as being associated with lower levels of 25-hydroxyvitamin D [25(OH)D]. Genetic variations within the vitamin D receptor (VDR) gene could lead to significant receptor dysfunction, and could further affect the formation of the biologically active 25(OH)D. Therefore, we hypothesized that VDR polymorphisms might be involved in vitiligo by affecting the formation of 25(OH)D. OBJECTIVES: To evaluate the potential association between VDR polymorphisms and vitiligo susceptibility and the serum levels of 25(OH)D. METHODS: We performed a hospital-based study of 749 patients with vitiligo and 763 matched controls. We investigated four VDR polymorphisms (FokI, BsmI, ApaI and TaqI) to determine whether they are associated with vitiligo susceptibility in the Chinese population. In addition, the levels of 25(OH)D were measured to evaluate possible associations between the VDR polymorphic variants and clinical and laboratory findings of vitiligo. RESULTS: A significantly decreased risk of developing vitiligo was found to be associated with the BsmI-B, ApaI-A and TaqI-t alleles. According to the genotype distribution, 25(OH)D concentrations were significantly higher in patients carrying the FokI ff or ApaI AA genotypes compared with those carrying the FF or aa genotypes. Logistic regression analysis also showed a dose-response relationship between decreased risk of vitiligo and increased 25(OH)D levels in ApaI-A variant genotype carriers. CONCLUSIONS: Our findings suggest that these VDR polymorphisms are associated with 25(OH)D levels and that there exists a genetic predisposition for vitiligo in the Chinese population.

The association of functional polymorphisms in the aryl hydrocarbon receptor (AHR) gene with the risk of vitiligo in Han Chinese populations.

BACKGROUND: Vitiligo is an acquired depigmentation disorder resulting from selective destruction of melanocytes. The aryl hydrocarbon receptor (AHR) is vital to the regulation of melanogenesis and melanocyte proliferation and differentiation through modulating the expressions of melanogenesis-related genes. AHR mutations may negatively affect AHR proteins and its target genes. Therefore, we hypothesized that AHR polymorphisms might be involved in vitiligo by impacting the transcriptional activities of related genes as mentioned above. OBJECTIVES: To evaluate the potential association between AHR polymorphisms and vitiligo susceptibility. METHODS: We performed a hospital-based, case-control study of 1000 patients with vitiligo and 1000 vitiligo-free but age- and gender-matched controls. Two single nucleotide polymorphisms of the AHR gene (rs10249788 and rs2066853) were selected and genotyped using a polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: A statistically significantly decreased risk of vitiligo was found to be associated with the TT and CT genotypes of rs10249788 [odds ratio (OR) 0·59, 95% confidence interval (CI) 0·38-0·93; P = 0·028 and OR 0·82, 95% CI 0·68-0·98; P = 0·032, respectively] as well as among subgroups: male, active, nonsegmental vitiligo, and onset age ≤ 20 years. Moreover, subjects with the combined (CT + TT)/GG genotype or T/G haplotype (rs10249788/rs2066853) showed a decreased risk for vitiligo (OR 0·57, 95% CI 0·37-0·87, P = 0·009 and OR 0·78, 95% CI 0·64-0·96, P = 0·033, respectively). CONCLUSIONS: These results suggest that the T allele of rs10249788 located in the promoter of the AHR gene is associated with a protective effect on vitiligo in Han Chinese populations.

Decreased methionine sulphoxide reductase A expression renders melanocytes more sensitive to oxidative stress: a possible cause for melanocyte loss in vitiligo.

BACKGROUND: Methionine is one of the major targets of reactive oxygen species (ROS). It is readily oxidized to methionine-S-sulphoxide and methionine-R-sulphoxide, which can be reduced by methionine sulphoxide reductase (MSR) A and B, respectively. MSR represents a unique repair mechanism in the skin antioxidant network. It functions both as a protein repairer and as a ROS scavenger. However, the expression and activity of MSR are significantly reduced in vitiligo. OBJECTIVES: To investigate whether the decreased expression of MSRA is one of the reasons why melanocytes are especially vulnerable to oxidative stress in vitiligo. Methods We downregulated MSRA expression in immortalized human epidermal melanocyte cell line PIG1 by using the short interfering RNA (siRNA)-targeted gene silencing method. We checked the changes in MSRA transcript and protein level by using reverse transcriptase-polymerase chain reaction and Western blot, respectively. Then we monitored the viability of MSRA-silenced melanocytes under oxidative stress. All statistical analysis was performed by unpaired two-tailed Student's t-test. RESULTS: The siRNA specific for MSRA successfully suppressed MSRA expression in melanocytes. The lower MSRA expression in melanocytes led to an increased sensitivity to oxidative stress, resulting in more cell death. Furthermore, a remarkable loss of viable cells was found in MSRA-silenced melanocytes even in the absence of exogenously added oxidative stress. CONCLUSIONS: MSRA is crucial for melanocytes to fight against oxidative stress in vitiligo. In addition, it is also important for normal cell survival. Any means to enhance MSRA appears to have therapeutic potential for the treatment of vitiligo.

A functional promoter polymorphism in monocyte chemoattractant protein-1 is associated with psoriasis.

Psoriasis is one of the most common inflammatory diseases of skin. MCP-1 is an important CC-type chemokine responsible for monocytes and T lymphocytes recruitment in inflammatory conditions. A single nucleotide polymorphism of the MCP-1 gene in the gene regulatory region was found to be related to the expression of MCP-1, and the associations of this polymorphism with many inflammatory diseases were conformed. However, the significance of this polymorphism in psoriasis remains unclear. Therefore, we examined this polymorphism in 507 patients with plaque-type psoriasis and 530 healthy controls using the polymerase chain reaction-restriction fragment length polymorphism method. We also tested the serum MCP-1 in 320 patients and 160 controls and compared the serum MCP-1 level in patients of different genotypes. Our results showed that the frequency distribution of the AA, AG and GG genotypes between the patients and the controls was statistically different (P = 0.031); significantly increased risk for psoriasis was associated with the AG, GG and AG + GG genotype. The frequency distribution of the AA, AG and GG genotypes was also different between female psoriasis patients and controls (P = 0.025), between type I psoriasis patients and controls (P = 0.025), between psoriasis patients without positive familial history and controls (P = 0.048), and between patients with psoriasis area and severity index of > or = 10 and controls (P = 0.041). MCP-1 serum level was significantly higher in patients than controls (P < 0.0001). There were significant differences of serum MCP-1 level between patients of the GG genotype and the AA genotype (P = 0.028), between patients of the AG genotype and the AA genotype (P = 0.049), and between patients of the AG + GG genotype and the AA genotype (P = 0.027). These results showed the -2518 MCP-1 polymorphism is related to the susceptibility of plaque type psoriasis. Individuals containing the GG or AG genotype were at higher risk of psoriasis than subjects with the AA genotype.

Dyschromatosis universalis hereditaria: two cases in a Chinese family.

Two cases of dyschromatosis universalis hereditaria (DUH) from a Chinese family are presented. Case 1 was a 62-year-old woman who had a generalized and progressive hyper- and hypopigmentation of the skin from the age of 8 years. Her brother had also developed a similar skin pigmentary defect from about the same age. Histopathological and ultrastructural examination of lesional skin showed increased melanin content in epidermal keratinocytes but no changes in the appearance or number of melanocytes. Although hereditary defects may influence melanogenesis resulting in a pigmentary anomaly, the pathogenesis of DUH remains unclear.

The effect of antisense tyrosinase-related protein 1 on melanocytes and malignant melanoma cells.

BACKGROUND: Tyrosinase-related proteins (TRPs) include tyrosinase, TRP-1 and TRP-2. The functions of tyrosinase and TRP-2 have been determined, but the biological role of TRP-1 is still controversial and is not well known in humans. OBJECTIVES: To study further the biological role of the human TRP-1 gene in melanocytes and melanoma cells. METHODS: TRP-1 cDNA was subcloned into eukaryotic expression vector pcDNA3.1 in the reverse direction, and antisense recombinant vector was transfected into melanocytes and a melanoma cell line using Lipofectamine 2000. Positive cells were selected by geneticin. TRP-1 mRNA level was measured by reverse transcription-polymerase chain reaction (RT-PCR), and TRP-1 protein level by Western blot. Cell cycles were determined by flow cytometry, and the activity of tyrosinase was evaluated by L-DOPA reaction. Light microscopy, electron microscopy and flow cytometry were used to observe cell morphology and apoptosis. For in vivo assays, the antitumour activity of antisense TRP-1 against the malignant melanoma (MM) cell line, Libr, was evaluated in an animal-tumour model of subcutaneous tumours. RESULTS: Positive transfected cells steadily expressed TRP-1 antisense RNA. RT-PCR and Western blot showed a low level of TRP-1 mRNA and TRP-1 protein, respectively. Cell cycles were blocked in the G1 stage, and the activity of tyrosinase decreased significantly (P < 0.01). Light and electron microscopy showed abnormal cell morphology, and apoptosis was detected. The neoplasia activity of antisense TRP-1-transfected MM cells was significantly lower than that of MM cells (P < 0.01). CONCLUSIONS: TRP-1 plays an important role in the proliferation, morphology and tyrosinase activity of melanocytes and melanoma cells.

Fatal bacteria granuloma after trauma: a new entity.

In the past 20 years, more than 20 cases of a type of granulomatous disease have been noticed by dermatologists in different areas of China. The patients had these features in common: (i) the lesions followed a slight trauma to the face; (ii) they were spreading dark-red plaques without pus or ulceration; (iii) new lesions appeared near to or far from the original lesion; (iv) histopathology showed histiocytic granuloma; (v) the patients had severe headache and clouding of consciousness during the later stages of the disease; (vi) all patients died within 1.5-4 years; (vii) treatment with prednisone led to some healing of the lesions but accelerated death; and (viii) all patients were from rural areas. We examined the tissues from two similar patients by electron microscopy and identified two kinds of bacteria as a possible cause of the disease. One was an anaerobic actinomycete, the other was Staphylococcus capitis. The anaerobic actinomycete was sensitive to lincomycin (a forerunner of clindamycin). After a 5-month therapy with lincomycin, one patient survived. We infer that the cause of death is the unknown anaerobic actinomycete. Because the disease is very severe, we suggest the name 'fatal bacteria granuloma after trauma' to draw attention.

Purification of natural antikeratin autoantibodies from normal human serum and their effect on human keratinocytes cultured in vitro.

BACKGROUND: Antikeratin (AK) autoantibodies, circulating antibodies against epidermal keratins, have been detected in all normal human sera. However, direct evidence on the biological significance of AK autoantibodies is still lacking. OBJECTIVES: To purify AK autoantibodies from human serum and to make a preliminary study of their biological effects on human keratinocytes. METHODS: We first extracted keratin polypeptides from human stratum corneum and analysed their purity using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Next, a keratin affinity column was prepared with the extracted keratins, and AK autoantibodies were purified from pooled normal human serum. Antibodies obtained were identified with SDS-PAGE, enzyme-linked immunosorbent assay, immunoperoxidase staining, immunoelectron microscopy and Western blotting. The biological effect of AK autoantibodies on cultured human keratinocytes was studied using a DNA synthesis assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric determination and cell cycle analysis. RESULTS: On average, 1.83 +/- 0.24 mg of antibodies could be purified from 10 mL of pooled human serum. High-titre IgG (about 1 : 70) and low-titre IgM (about 1 : 30) AK autoantibodies were obtained. The DNA synthesis assay and MTT colorimetric determination demonstrated that AK autoantibodies have a significant dose-dependent inhibitory effect on cultured keratinocytes. Correlation coefficients in the two experiments were - 0.583 and - 0.797, respectively. Cell cycle analysis indicated that a small dose of AK autoantibodies leads to inhibition of proliferation of cultured keratinocytes, whereas a large dose of AK autoantibodies causes a visible hypodiploid peak, suggesting apoptosis of keratinocytes. CONCLUSIONS: The present research lays a solid foundation for further investigation into the biological significance of natural AK autoantibodies.