Skin diseases in the Da Qing Diabetes Study: a cross-sectional study.

BACKGROUND: The prevalence of skin diseases and diabetes mellitus (DM) are prominent around the world. The current scope of knowledge regarding the prevalence of skin diseases and comorbidities with type 2 DM (T2DM) is limited, leading to limited recognition of the correlations between skin diseases and T2DM. METHODS: We collected 383 subjects from the Da Qing Diabetes Study during the period from July 9th to September 1st, 2016. The subjects were categorized into three groups: Normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and T2DM. The prevalence and clinical characteristics of skin diseases were recorded and investigated. RESULTS: In this cross-sectional study, 383 individuals with ages ranging from 53 to 89-year-old were recruited. The overall prevalence of skin diseases was 93.5%, and 75.7% of individuals had two or more kinds of skin diseases. Additionally, there were 47 kinds of comorbid skin diseases in patients with T2DM, of which eight kinds of skin diseases had a prevalence >10%. The prevalence of skin diseases in NGT, IGT, and T2DM groups were 93.3%, 91.5%, and 96.6%, respectively; stratified analysis by categories showed a statistically significant difference in "disturbances of pigmentation" and "neurological and psychogenic dermatoses". The duration of T2DM also significantly associated with the prevalence of "disturbances of pigmentation" and "neurological and psychogenic dermatoses". Subsequently, the prevalence of "disturbances of pigmentation" was higher in males than females in NGT (P < 0.01) and T2DM (P < 0.01) groups. In addition, the difference in the prevalence of "disturbances of pigmentation" was also significant in NGT and T2DM groups (P < 0.01). CONCLUSIONS: There was a high prevalence of skin diseases in the Da Qing Diabetes Study. To address the skin diseases in the Da Qing Diabetes Study, increased awareness and intervention measures should be implemented.

Association analyses identify two susceptibility loci 5q31 and 5q22.1 for atopic dermatitis in Chinese Han population.

BACKGROUND: Atopic dermatitis (AD) and other atopic diseases often share some common genetic and pathogenic bases. Recent genome-wide association studies (GWAS) have identified several loci associated with atopic diseases, allergic sensitization and asthma in different populations. The aim of this study was to investigate whether these susceptibility loci were related to AD in Chinese Han population. METHODS: Eight single nucleotide polymorphisms (SNPs) from recent atopic diseases and allergic sensitization GWAS were genotyped in 3,013 AD patients and 5,483 healthy controls in Chinese Han population using Sequenom MassArray system. Data was analyzed with PLINK 1.07 software. RESULTS: We identified that the susceptibility loci at 5q31 (RAD50/IL13, rs2158177, P = 1.08×10-3, OR = 1.15) and 5q22.1 (TSLP, rs1837253, P = 2.66×10-3, OR = 0.91) were significantly associated with AD. Genotype-based association testing revealed that the dominant model provided the best fit for both rs2158177 (P = 3.75×10-3) and rs1837253 (P = 5.30×10-3). Pathway analysis conformed that both loci were associated with the JAK-STAT signaling pathway. CONCLUSIONS: We identified two susceptibility loci 5q31 and 5q22.1 for AD that might bear candidate genes conferring susceptibility to AD.

Scanning indels in the 5q22.1 region and identification of the TMEM232 susceptibility gene that is associated with atopic dermatitis in the Chinese Han population.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease. The 5q22.1 region was found to have an association with AD in our previous genome-wide association study (GWAS). OBJECTIVE: To identify the AD susceptibility gene in 5q22.1 and observe its expression in AD tissues. METHODS: Suggestive indels from the GWAS data were genotyped in 3013 AD patients and 5075 controls from the Chinese Han population with the SequenomMassArray system. Association, Bayesian and bioinformatics analyses were used to identify possible causal indels and genes in the 5q22.1 region. Immunohistochemistry (IHC) was performed to observe protein expression in the tissues. PLINK 1.07 software was used for all statistical analyses. RESULTS: The genotyping and association analysis showed that six deletions and four SNPs were associated with AD (P<0.005). The rs11357450 (Pcombined=7.79E-04, OR=1.39, logBayes Factor=1.29) deletion located in TMEM232 was identified to be the strongest variant. Analysis of the genetic model revealed that the dominant model best described rs11357450 (P=1.96E-03, OR=1.22; 95% CI=1.07-1.37). IHC showed that the expression of TMEM232 decreased gradually from the granular layer to the basal layer in AD, but in normal tissues, this trend was reversed. Additionally, positive cytoplasm staining was found in lymphocytes around the blood vessels in AD. CONCLUSIONS: The study indicates that TMEM232 in the 5q22.1 region is the causal gene for AD in the Chinese Han population.

Increased expression of IL-28RA mRNA in peripheral blood mononuclear cells from patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a systemic autoimmune and inflammatory disease with a strong genetic contribution and characterized by kinds of immune reactions. Our previous genome-wide association studies have identified IL-28RA as a susceptibility gene for SLE. In this study, we performed a quantitative reverse transcription polymerase chain reaction (RT-PCR) in 62 patients with SLE and 69 controls to investigate the different expression levels of IL-28RA in peripheral blood mononuclear cells (PBMCs) from SLE patients and healthy controls and the association between IL-28RA expression and systemic lupus erythematosus disease activity index (SLEDAI) or the variant of the single-nucleotide polymorphism (SNP) rs4649203. The expression levels of IL-28RA messenger RNA (mRNA) in SLE patients were significantly increased compared with those of healthy controls. In addition, there were also significant differences in the expression levels of IL-28RA between active (SLEDAI ≥ 6) or inactive (SLEDAI < 6) SLE groups and healthy controls. However, no correlation was observed between IL-28RA mRNA expression level and SLEDAI. There was no association between the variant of the SNP rs4649203 and IL-28RA mRNA expression levels neither. These results indicated that expression of IL-28RA mRNA may be correlated with the pathogenesis of SLE.

Association analyses confirm five susceptibility loci for systemic lupus erythematosus in the Han Chinese population.

INTRODUCTION: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease. Currently, numerous genetic loci of SLE have been confirmed. Here we try to further explore additional genes contributing to SLE susceptibility in this study. METHODS: Forty nine single nucleotide polymorphisms (SNPs) with moderate-risk for SLE in previous study were genotyped in a large-scale replication study with a total of 3,522 cases and 8,252 controls using the Sequenom Massarray system. Association analyses were performed using logistic regression with gender or sample cohorts as a covariate through PLINK 1.07 software. RESULTS: This replication effort confirmed five reported SLE susceptibility loci reaching genome-wide levels of significance (P(meta) <5.00 × 10(-08)): TNFSF4 (rs1418190, odds ratio (OR) = 0.81, P(meta) = 1.08 × 10(-08); rs4916219, OR = 0.80, P(meta )= 7.77 × 10(-09)), IRF8 (rs2934498, OR = 1.25, P(meta) = 4.97 × 10(-09)), miR-146a (rs2431697, OR = 0.69, P(meta) = 1.15 × 10(-22)), CD44 (rs2732547, OR = 0.82, P(meta) = 1.55 × 10(-11)), and TMEM39A (rs12494314, OR = 0.84, P(meta) = 1.01 × 10(-09)). Further logistic regression analysis indicated that the genetic effects within TNFSF4 detected in this study are independent from our previously reported signals. CONCLUSIONS: This study increases the number of established susceptibility loci for SLE in Han Chinese population and highlights the contribution of multiple variants of modest effect. Although further studies will be required to identify the causal alleles within these loci, the findings make a significant step forward in our understanding of the genetic contribution to SLE in Chinese population.

Variants in TNFSF4, TNFAIP3, TNIP1, BLK, SLC15A4 and UBE2L3 interact to confer risk of systemic lupus erythematosus in Chinese population.

Our previous genome-wide association studies on SLE have identified several susceptibility genes involved in NF-κB signaling pathway, including TNFSF4, TNFAIP3, TNIP1, BLK, SLC15A4 and UBE2L3. The aim of this study is to investigate the association model (additive, dominant, recessive) of these genes and search for possible gene-gene interactions between them. In this study, we explored the association model of these six genes and search for possible gene-gene interactions based on identified single-nucleotide polymorphisms (SNPs) among them by using logistic regression analysis in the combined sample of 4,199 cases and 8,255 controls. The most significant association evidence was observed under recessive model for all of these SNPs. Besides, significant interactions between these SNPs were observed in this study: the TNFSF4 and TNIP1 SNPs (P adjusted = 1.68E-10), the TNFSF4 and SLC15A4 SNPs (P adjusted = 3.55E-08), the TNFSF4 and UBE2L3 SNPs (P adjusted = 8.74E-13), the TNIP1 and BLK SNPs (P adjusted = 9.45E-10), the TNIP1 and UBE2L3 SNPs (P adjusted = 8.25E-11), the TNFAIP3 and UBE2L3 SNPs (P adjusted = 3.06E-14) and the BLK and SLC15A4 SNPs (P adjusted = 4.51E-12). These results may contribute to our understanding of SLE genetic interactions and account for the additional risk of certain patients to develop SLE.

Identification of a missense variant in LNPEP that confers psoriasis risk.

Psoriasis is a chronic inflammatory disease with a complex genetic architecture. To further advance gene discovery, we extended our genome-wide association study data set of 1,139 cases and 2,234 controls and replicated two independent cohorts of 7,200 cases and 10,491 controls. We identified the missense variant rs2303138 (p.Ala763Thr) within the LNPEP gene associated with psoriasis (Pcombined=1.83 × 10(-13), odds ratio=1.16) and validated four previously reported genes: IL28RA, NFKBIA, TRAF3IP2, and CARD14 (9.74 × 10(-11)P9.37 × 10(-5)), which confirmed the involvement of the nuclear factor-κB signaling pathway in psoriasis pathogenesis. LNPEP, also named insulin-responsive aminopeptidase, was identified as an angiotensin IV receptor. Protein function prediction suggested that this missense variant of LNPEP was most likely deleterious. Expression analysis showed that LNPEP was significantly downregulated in psoriatic lesions compared with the control skin (P=1.44 × 10(-6)) and uninvolved patient skin (P=2.95 × 10(-4)). Pathway analysis indicated that LNPEP was involved in the renin-angiotensin system, which also has a key role in cardiovascular disease and diabetes. These results provided genetic evidence that psoriasis might share common mechanisms with hypertension and diabetes, which was consistent with clinical observations. Our study identified a genetic susceptibility factor and provided genetic evidence of insight into psoriasis pathogenesis with the involvement of the renin-angiotensin system pathway.

TNIP1/ANXA6 and CSMD1 variants interacting with cigarette smoking, alcohol intake affect risk of psoriasis.

BACKGROUND: Psoriasis is a common multi-factorial skin disease, in which gene-gene and gene-environment interactions may affect the onset, manifestation and clinical course. OBJECTIVE: To investigate the underlying gene-environment interaction among several established susceptibility genes, cigarette smoking and alcohol intake. METHODS: Using a two-stage case-control design, we searched for pairwise interactions between cigarette smoking and alcohol intake respectively with 9 single nucleotide polymorphisms (SNPs) at ERAP1, PTTG1, CSMD1, GJB2, SERPINB8, ZNF816A and TNIP1/ANXA6 that have been associated with risk for psoriasis in 7,223 subjects. Multiple logistic regression analysis was used for data analysis. RESULTS: Significant interactions were found for alcohol intake with rs3762999 (p=0.0257) and rs999556 (p=0.0071) at TNIP/ANXA6; and for cigarette smoking with rs7007032 (p=0.0023) and rs10088247 (p=0.0023) at CSMD1. CONCLUSION: This study provides empirical evidence for the gene-environment interactions between TNIP1/ANXA6 and alcohol use, CSMD1 and cigarette smoking, highlighting the importance of gene-environment interactions in the pathogenesis of psoriasis.

IKZF1: a critical role in the pathogenesis of systemic lupus erythematosus?

Ikaros family zinc finger 1, encoded by IKZF1, are lymphoid-restricted zinc finger transcription factors that share common N-terminal Kruppel-like zinc finger DNA-binding domain. IKZF1 play multiple important roles on regulators of lymphocyte differentiation and hematological tumor suppressor. Our genome-wide association (GWA) studies in systemic lupus erythematosus (SLE) independently identified genetic variants in IKZF1 associated with SLE, which are supported by other studies. Previous studies found that lower expression of IKZF1 may play critical roles in activating some signal pathways involved in SLE, such as signal transducers and activators of transcription (STAT)4 and interferon pathways. In addition, IKZF1 has been implicated in roles involved in some hematologic traits or abnormalities, such as erythrocyte measures, myelofibrosis, and acute lymphoblastic leukemia (ALL), which may be common clinical manifestations or co-occurrence hematological diseases of patients with SLE. All these findings suggest that IKZF1 may play a critical role in the pathogenesis of SLE. In this article, we discuss the existing understanding of the role of IKZF1 on the physiological and pathological functions associated with SLE, providing insights that may assist in the development of new therapeutic strategies based on IKZF1 for patients with SLE.

Genome-wide copy number variation study in anorectal malformations.

Anorectal malformations (ARMs, congenital obstruction of the anal opening) are among the most common birth defects requiring surgical treatment (2-5/10 000 live-births) and carry significant chronic morbidity. ARMs present either as isolated or as part of the phenotypic spectrum of some chromosomal abnormalities or monogenic syndromes. The etiology is unknown. To assess the genetic contribution to ARMs, we investigated single-nucleotide polymorphisms and copy number variations (CNVs) at genome-wide scale. A total of 363 Han Chinese sporadic ARM patients and 4006 Han Chinese controls were included. Overall, we detected a 1.3-fold significant excess of rare CNVs in patients. Stratification of patients by presence/absence of other congenital anomalies showed that while syndromic ARM patients carried significantly longer rare duplications than controls (P = 0.049), non-syndromic patients were enriched with both rare deletions and duplications when compared with controls (P = 0.00031). Twelve chromosomal aberrations and 114 rare CNVs were observed in patients but not in 868 controls nor 11 943 healthy individuals from the Database of Genomic Variants. Importantly, these aberrations were observed in isolated ARM patients. Gene-based analysis revealed 79 genes interfered by CNVs in patients only. In particular, we identified a de novo DKK4 duplication. DKK4 is a member of the WNT signaling pathway which is involved in the development of the anorectal region. In mice, Wnt disruption results in ARMs. Our data suggest a role for rare CNVs not only in syndromic but also in isolated ARM patients and provide a list of plausible candidate genes for the disorder.

Exome sequencing identifies MVK mutations in disseminated superficial actinic porokeratosis.

Disseminated superficial actinic porokeratosis (DSAP) is an autosomal dominantly inherited epidermal keratinization disorder whose etiology remains unclear. We performed exome sequencing in one unaffected and two affected individuals from a DSAP family. The mevalonate kinase gene (MVK) emerged as the only candidate gene located in previously defined linkage regions after filtering against existing SNP databases, eight HapMap exomes and 1000 Genomes Project data and taking into consideration the functional implications of the mutations. Sanger sequencing in 57 individuals with familial DSAP and 25 individuals with sporadic DSAP identified MVK mutations in 33% and 16% of these individuals (cases), respectively. All 14 MVK mutations identified in our study were absent in 676 individuals without DSAP. Our functional studies in cultured primary keratinocytes suggest that MVK has a role in regulating calcium-induced keratinocyte differentiation and could protect keratinocytes from apoptosis induced by type A ultraviolet radiation. Our results should help advance the understanding of DSAP pathogenesis.

Association analysis of single nucleotide polymorphisms at five loci: comparison between atopic dermatitis and asthma in the Chinese Han population.

Atopic diseases, such as atopic dermatitis (AD) and asthma, are closely related to clinical phenotypes with hypersensitivity, and often share some similar genetic and pathogenic bases. Our recent GWAS identified three susceptibility gene/loci FLG (rs11204971 and rs3126085), 5q22.1 (rs10067777, rs7701890, rs13360927 and rs13361382) and 20q13.33 (rs6010620) to AD. The effect of these AD associated polymorphisms in asthma is so far unknown. To investigate whether AD relevant genetic variants is identical to asthma and reveal the differences in genetic factors between AD and asthma in Chinese Han population, seven AD associated single nucleotide polymorphisms (SNPs) as well as 3 other SNPs (rs7936562 and rs7124842 at 11q13.5 and rs4982958 at 14q11.2) from our previous AD GWAS were genotyped in 463 asthma patients and 985 controls using Sequenom MassArray system. We found rs4982958 at 14q11.2 was significantly associated with asthma (P = 3.04×10(-4), OR = 0.73). We also detected one significant risk haplotype GGGA from the 4 SNPs (rs10067777, rs7701890, rs13360927 and rs13361382) at 5q22.1 in AD cases (P(correction) = 3.60×10(-10), OR = 1.26), and the haplotype was suggestive of risk in asthma cases in this study (P = 0.014, P(correction) = 0.084, OR = 1.38). These SNPs (rs11204971, rs3126085, rs7936562, rs712484 and rs6010620) at AD susceptibility genes/loci FLG, 11q13.5 and 20q13.33 were not associated with asthma in this study. Our results further comfirmed that 14q11.2 was an important candidate locus for asthma and demonstrated that 5q22.1 might be shared by AD and asthma in Chinese Han population.

A genome-wide association study in Han Chinese identifies multiple susceptibility loci for IgA nephropathy.

We performed a two-stage genome-wide association study of IgA nephropathy (IgAN) in Han Chinese, with 1,434 affected individuals (cases) and 4,270 controls in the discovery phase and follow-up of the top 61 SNPs in an additional 2,703 cases and 3,464 controls. We identified associations at 17p13 (rs3803800, P = 9.40 × 10(-11), OR = 1.21; rs4227, P = 4.31 × 10(-10), OR = 1.23) and 8p23 (rs2738048, P = 3.18 × 10(-14), OR = 0.79) that implicated the genes encoding tumor necrosis factor (TNFSF13) and α-defensin (DEFA) as susceptibility genes. In addition, we found multiple associations in the major histocompatibility complex (MHC) region (rs660895, P = 4.13 × 10(-20), OR = 1.34; rs1794275, P = 3.43 × 10(-13), OR = 1.30; rs2523946, P = 1.74 × 10(-11), OR = 1.21) and confirmed a previously reported association at 22q12 (rs12537, P = 1.17 × 10(-11), OR = 0.78). We also found that rs660895 was associated with clinical subtypes of IgAN (P = 0.003), proteinuria (P = 0.025) and IgA levels (P = 0.047). Our findings show that IgAN is associated with variants near genes involved in innate immunity and inflammation.

Genome-wide association study identifies a susceptibility locus for schizophrenia in Han Chinese at 11p11.2.

To identify susceptibility loci for schizophrenia, we performed a two-stage genome-wide association study (GWAS) of schizophrenia in the Han Chinese population (GWAS: 746 individuals with schizophrenia and 1,599 healthy controls; validation: 4,027 individuals with schizophrenia and 5,603 healthy controls). We identified two susceptibility loci for schizophrenia at 6p21-p22.1 (rs1233710 in an intron of ZKSCAN4, P(combined) = 4.76 × 10(-11), odds ratio (OR) = 0.79; rs1635 in an exon of NKAPL, P(combined) = 6.91 × 10(-12), OR = 0.78; rs2142731 in an intron of PGBD1, P(combined) = 5.14 × 10(-10), OR = 0.79) and 11p11.2 (rs11038167 near the 5' UTR of TSPAN18, P(combined) = 1.09 × 10(-11), OR = 1.29; rs11038172, P(combined) = 7.21 × 10(-10), OR = 1.25; rs835784, P(combined) = 2.73 × 10(-11), OR = 1.27). These results add to previous evidence of susceptibility loci for schizophrenia at 6p21-p22.1 in the Han Chinese population. We found that NKAPL and ZKSCAN4 were expressed in postnatal day 0 (P0) mouse brain. These findings may lead to new insights into the pathogenesis of schizophrenia.

Psoriasis regression analysis of MHC loci identifies shared genetic variants with vitiligo.

Psoriasis is a common inflammatory skin disease with genetic components of both immune system and the epidermis. PSOR1 locus (6q21) has been strongly associated with psoriasis; however, it is difficult to identify additional independent association due to strong linkage disequilibrium in the MHC region. We performed stepwise regression analyses of more than 3,000 SNPs in the MHC region genotyped using Human 610-Quad (Illumina) in 1,139 cases with psoriasis and 1,132 controls of Han Chinese population to search for additional independent association. With four regression models obtained, two SNPs rs9468925 in HLA-C/HLA-B and rs2858881 in HLA-DQA2 were repeatedly selected in all models, suggesting that multiple loci outside PSOR1 locus were associated with psoriasis. More importantly we find that rs9468925 in HLA-C/HLA-B is associated with both psoriasis and vitiligo, providing first important evidence that two major skin diseases share a common genetic locus in the MHC, and a basis for elucidating the molecular mechanism of skin disorders.

Interleukin 29 enhances expression of Toll receptor 3 and mediates antiviral signals in human keratinocytes.

OBJECTIVE: Interleukin 29 (IL-29) is a class II cytokine and displays numerous immune functions other than its anti-viral and antiproliferation activities. This study is focused on the effect of IL-29 on human keratinocytes (KCs). METHODS: Primary KCs were stimulated by various concentrations of IL-29 for different time periods, and antiviral proteins and TLR3 gene expression were then analyzed by real-time PCR. The signal pathways activated by IL-29 in KCs were detected by western blot. The antiviral activity of IL-29 was determined by methylthiazolyldiphenyl-tetrazolium bromide, and small interfering RNA knockdown was used to analyze the role of toll receptor 3 (TLR3) in the antiviral activity of IL-29. RESULTS: IL-29 was able to induce expression of antiviral proteins and TLR3 gene expression in KCs. IL-29 pretreatment strongly enhanced herpes simplex virus type 1 (HSV-1)-induced expression of the interferon ß (IFN-ß) gene and protected the KCs from HSV-1 challenge. The IL-29 antiviral activity was partially dependent on TLR3 expression induced by this cytokine, and mechanistic studies demonstrated that the regulation of TLR3 expression by IL-29 might be partially dependent on Janus kinase /signal transducer and activator of transcription (JAK-STATs) activation. CONCLUSION: IL-29-induced TLR3 expression is involved in antiviral activity of IL-29 in KCs, which suggests a feasible method to cure certain viral infections of the skin.

Genome-wide association study identifies two new susceptibility loci for atopic dermatitis in the Chinese Han population.

Atopic dermatitis is a chronic, relapsing form of inflammatory skin disorder that is affected by genetic and environmental factors. We performed a genome-wide association study of atopic dermatitis in a Chinese Han population using 1,012 affected individuals (cases) and 1,362 controls followed by a replication study in an additional 3,624 cases and 12,197 controls of Chinese Han ethnicity, as well as 1,806 cases and 3,256 controls from Germany. We identified previously undescribed susceptibility loci at 5q22.1 (TMEM232 and SLC25A46, rs7701890, P(combined) = 3.15 × 10(-9), odds ratio (OR) = 1.24) and 20q13.33 (TNFRSF6B and ZGPAT, rs6010620, P(combined) = 3.0 × 10(-8), OR = 1.17) and replicated another previously reported locus at 1q21.3 (FLG, rs3126085, P(combined) = 5.90 × 10(-12), OR = 0.82) in the Chinese sample. The 20q13.33 locus also showed evidence for association in the German sample (rs6010620, P = 2.87 × 10(-5), OR = 1.25). Our study identifies new genetic susceptibility factors and suggests previously unidentified biological pathways in atopic dermatitis.