Proteomic analyses reveal cystatin c is a promising biomarker for evaluation of systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune disease with multiple organ involvement, especially the kidneys. However, the underlying mechanism remains unclear, and accurate biomarkers are still lacking. This study aimed to identify biomarkers to assess organ damage and disease activity in patients with SLE using quantitative proteomics. METHODS: Proteomic analysis was performed using mass spectrometry in 15 patients with SLE and 15 age-matched healthy controls. Proteomic profiles were compared in four main subtypes: SLE with proteinuria (SLE-PN), SLE without proteinuria (SLE-non-PN), SLE with anti-dsDNA positivity (SLE-DP), and SLE with anti-dsDNA negativity (SLE-non-DP). Gene ontology biological process analysis revealed differentially expressed protein networks. Cystatin C (CysC) levels were measured in 200 patients with SLE using an immunoturbidimetric assay. Clinical and laboratory data were collected to assess their correlation with serum CysC levels. RESULTS: Proteomic analysis showed that upregulated proteins in both the SLE-PN and SLE-DP groups were mainly mapped to neutrophil activation networks. Moreover, CysC from neutrophil activation networks was upregulated in both the SLE-PN and SLE-DP groups. The associations of serum CysC level with proteinuria, anti-dsDNA positivity, lower complement C3 levels, and SLE disease activity index score in patients with SLE were further validated in a large independent cohort. CONCLUSIONS: Neutrophil activation is more prominent in SLE with proteinuria and anti-dsDNA positivity, and CysC is a promising marker for monitoring organ damage and disease activity in SLE.

AURKA facilitates the psoriasis-related inflammation by impeding autophagy-mediated AIM2 inflammasome suppression.

Psoriasis is an immune-mediated genetic disease involving innate and the adaptive immune system. Aurora kinase A (AURKA) belongs to a seine/threonine kinases family and is elevated in lesional psoriatic tissues. This research aimed to investigate the effects of AURKA on psoriasis progression and whether it worked by regulating autophagy or inflammasome activation. The results showed that the expression of AURKA was higher in psoriasis tissue than that in the psoriasis skin. IFN-γ (100 ng/mL) plus poly (dA:dT) (2 mg/mL) induced the increased AURKA, secretion of IL-1ß, IL-18 and the active form of caspase-1 (p20). AURKA knockdown inhibited the inflammatory responses of keratinocytes and the activation of AIM2 inflammasome, and enhanced autophagy. 3MA (autophagy inhibitor) attenuated the effects of AURKA on AIM2 inflammasome. In addition, AURKA promoted the activation of the AKT/mTOR pathway. Akt inhibitor (PI-103) attenuated AIM2 inflammasome activation induced by Aurka overexpression. In conclusion, this research demonstrated that AURKA promoted the psoriasis-related inflammation by blocking autophagy-mediated AIM2 inflammasome suppression. AURKA has the potential to be explored as a new promising target for the treatment for psoriasis.

Antineutrophil Cytoplasmic Antibody-Associated Vasculitis Update: Genetic Pathogenesis.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is characterized by the inflammation of small and medium vessels and presence of proteinase 3-ANCA or myeloperoxidase-ANCA in the circulation. AAV comprises three clinical subtypes: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic GPA (EGPA). Although the pathogenesis of AAV is still unclear, genetic and environmental factors and the immune system are thought to be involved. Genetic factors have been confirmed to play an important role in AAV. Genome-wide association studies have identified numerous genetic variants in MHC and non-MHC regions associated with AAV. The strongest evidence of MHC association in AAV is human leukocyte antigen (HLA)-DP. A significant association between AAV and genetic variations in non-MHC regions, such as CTLA-4, FCGR2A, PTPN22, SERPINA1, and TLR9 has also been found. Moreover, different clinical subtypes of AAV have distinct genetic backgrounds. GPA is associated with HLA-DP1, MPA with HLA-DQ, and EGPA with HLA-DRB4. These findings could help elucidate the etiology of AAV and develop new biomarkers for diagnosis and targeted therapy. Herein, we briefly summarize the updates on the genetic pathogenesis and biomarkers of AAV.

Real-world data on the use of secukinumab as treatment for moderate-to-severe psoriasis in Chinese patients.

BACKGROUND: The efficacy and safety of secukinumab, an interleukin-17 inhibitor, as systemic treatment for patients with moderate-to-severe psoriasis have been demonstrated, but real-world data pertaining to this is limited in China. OBJECTIVE: To evaluate the efficacy and safety of secukinumab in clinical practice in Chinese psoriasis patients with or without psoriatic arthritis (PsA) and identify potential baseline factors that affect the response of patients to secukinumab treatment. MATERIALS & METHODS: Data from 81 patients treated with secukinumab for at least 16 weeks were analysed in a retrospective observational study. RESULTS: After 16 weeks of treatment with secukinumab, 91.1%, 73%, and 38.3% of patients achieved a PASI 75 (75% improvement based on the Psoriasis Area and Severity Index), PASI 90, and PASI 100, respectively. A significant improvement in the quality of life of patients was also observed. Notably, baseline factors, such as young age, lower BMI, no scalp involvement and absence of concomitant PsA, were associated with better clinical response to secukinumab. Approximately 42% of patients (34/81) experienced adverse events, of which the most common was pruritus. CONCLUSION: The results demonstrated that secukinumab appears to be an effective treatment alternative for the majority of Chinese plaque psoriasis patients. Baseline factors, including age, BMI, scalp involvement and concomitant presence of PsA, were associated with response to secukinumab.

Identification of ST3AGL4, MFHAS1, CSNK2A2 and CD226 as loci associated with systemic lupus erythematosus (SLE) and evaluation of SLE genetics in drug repositioning.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with a strong genetic component in its pathogenesis. Through genome-wide association studies (GWAS), we recently identified 10 novel loci associated with SLE and uncovered a number of suggestive loci requiring further validation. This study aimed to validate those loci in independent cohorts and evaluate the role of SLE genetics in drug repositioning. METHODS: We conducted GWAS and replication studies involving 12 280 SLE cases and 18 828 controls, and performed fine-mapping analyses to identify likely causal variants within the newly identified loci. We further scanned drug target databases to evaluate the role of SLE genetics in drug repositioning. RESULTS: We identified three novel loci that surpassed genome-wide significance, including ST3AGL4 (rs13238909, pmeta=4.40E-08), MFHAS1 (rs2428, pmeta=1.17E-08) and CSNK2A2 (rs2731783, pmeta=1.08E-09). We also confirmed the association of CD226 locus with SLE (rs763361, pmeta=2.45E-08). Fine-mapping and functional analyses indicated that the putative causal variants in CSNK2A2 locus reside in an enhancer and are associated with expression of CSNK2A2 in B-lymphocytes, suggesting a potential mechanism of association. In addition, we demonstrated that SLE risk genes were more likely to be interacting proteins with targets of approved SLE drugs (OR=2.41, p=1.50E-03) which supports the role of genetic studies to repurpose drugs approved for other diseases for the treatment of SLE. CONCLUSION: This study identified three novel loci associated with SLE and demonstrated the role of SLE GWAS findings in drug repositioning.

Bach2 regulates aberrant activation of B cell in systemic lupus erythematosus and can be negatively regulated by BCR-ABL/PI3K.

OBJECTIVE: This study was aimed to explore the effect of Bach2 on B cells in systemic lupus erythematosus (SLE), as well as the underlying mechanisms. METHODS: Expression of Bach2, phosphorylated-Bach2 (p-Bach2), Akt, p-Akt and BCR-ABL (p210) in B cells isolated from SLE patients and the healthy persons were assessed by Western blot. Immunofluorescence staining was performed to assess the localization of Bach2 in B cells. Enzyme-linked immunosorbent assay (ELISA) was employed to detect IgG produced by B cells. Cell counting kit-8 (CCK-8) and Annexin-V FITC/PI double staining assay were adopted to evaluate cell proliferation and apoptosis in B cells, respectively. RESULTS: Compared to the healthy controls, Bach2, p-Akt and p210 were significantly decreased, while nuclear translocation of Bach2, IgG, CD40 and CD86 obviously up-regulated in B cells from SLE patients. Bach2 significantly inhibited the proliferation, promoted apoptosis of B cells from SLE patients, whereas BCR-ABL dramatically reversed cell changes induced by Bach2. Besides, BCR-ABL also inhibited nuclear translocation of Bach2 in B cells from SLE patients. Further, LY294002 treatment had no effect on decreased expression of Bach2 induced by BCR-ABL, but significantly eliminated BCR-ABL-induced phosphorylation of Bach2 and restored reduced nuclear translocation of Bach2 induced by BCR-ABL in B cells from SLE. CONCLUSIONS: Bach2 may play a suppressive role in B cells from SLE, and BCR-ABL may inhibit the nuclear translocation of Bach2 via serine phosphorylation through the PI3K pathway.

Association of the chromosome 11p13.5 variant and atopic dermatitis with a family history of atopy in the Chinese Han population.

BACKGROUND: Recent genome-wide association studies (GWAS) and a meta-analysis of GWAS for atopic dermatitis (AD) have identified some AD genetic loci in European and Japanese populations. OBJECTIVE: To investigate whether some novel susceptibility loci are associated with AD in the Chinese Han population. METHODS: We first selected eight novel susceptibility loci to replicate in 2,205 AD patients and 2,116 healthy controls using the Sequenom platform. Data were analyzed with PLINK 1.07 software. RESULTS: We found that rs12634229 (3q13.2), rs7927894 (11p13.5) and rs878860 (11p15.4) showed a slight association with AD (P = 0.012, P = 0.033, P = 0.020, respectively); rs6780220 (3p21.33) was preferentially related to AD with keratosis pilaris, but did not reach the threshold of significance after correction. The frequency of rs7927894 allele T was significantly different between AD patients with a positive and negative family history of atopy. CONCLUSION: The loci rs7927894 (11p13.5) are related to AD with a positive family history of atopy in Chinese Han population, providing novel insight into the genetic pathogenesis of AD.

Four genetic variants interact to confer susceptibility to atopic dermatitis in Chinese Han population.

Atopic dermatitis is a chronic inflammatory skin disease and is affected by environmental and genetic factors. Gene-gene/environment interactions are strongly believed to contribute to the genetic risk of common diseases. A number of gene-environment interactions of atopic dermatitis were performed. However, there are few comprehensive investigations on the gene-gene (or genetic variants) interactions for atopic dermatitis. We explored the association model of 6 single nucleotide polymorphisms (SNPs) which were most significant (P < 10E-05) in our previous genome wide association study (GWAS) for atopic dermatitis, and search for the possible genetic variant interactions based on the previous GWAS data using Generalized Multifactor Dimensionality Reduction and Plink 1.07 in the combined sample of 4,636 cases and 13,559 controls. The most significant associated evidence was observed under dominant model for SNPs rs3126085, rs12085366, and rs7701890, recessive model for SNP rs17173197, and additive model for SNPs rs2393903 and rs6010620. Three significant pair-way interactions were observed, including PRKAG2 and FLG SNPs (rs17173197 × rs3126085, P combined = 1.11E-15), PRKAG2 and TMEM232-SLC25A46 SNPs (rs17173197 × rs7701890, P combined = 2.22E-15), PRKAG2 and TNFRSF6B-ZGPAT SNPs (rs17173197 × rs6010620, P combined = 6.66E-16). Besides, a three-way significant interaction among PRKAG2, TMEM232-SLC25A46 and TNFRSF6B-ZGPAT SNPs (rs17173197 × rs7701890 × rs6010620, P combined = 5.99E-15) was observed in this study. These four genetic variant interactions confer susceptibility to atopic dermatitis, and highlight the genetic variant interactions in the etiology of atopic dermatitis in Chinese Han population.

Association of the late cornified envelope-3 genes with psoriasis and psoriatic arthritis: a systematic review.

Psoriasis (Ps) and psoriatic arthritis (PsA) are genetically complex diseases with strong genetic evidence. Recently, susceptibility genes for Ps and PsA have been identified within the late cornified envelop (LCE) gene cluster, especially the cluster 3 (LCE3) genes. It is noteworthy that the deletion of LCE3B and LCE3C (LCE3C_LCE3B-del) is significantly associated with these two diseases. Gene-gene interactions between LCE3 genes and other genes are associated with Ps and PsA. LCE3 genes also have pleiotropic effect on some autoimmune diseases, such as rheumatoid arthritis, atopic dermatitis and systemic lupus erythematosus. Further studies need to focus on the potential function of LCE3 genes in the pathogenesis of Ps and PsA in the future.

Exome sequencing identifies SLC17A9 pathogenic gene in two Chinese pedigrees with disseminated superficial actinic porokeratosis.

BACKGROUND: Disseminated superficial actinic porokeratosis (DSAP) is a rare autosomal dominant genodermatosis characterised by annular lesions that has an atrophic centre and a prominent peripheral ridge distributed on sun exposed area. It exhibits high heterogeneity, and five linkage loci have been reported. The mevalonate kinase (MVK) gene located on 12q24 has been confirmed as one of the disease-causing genes. But, the pathogenesis of a large part of DSAP remains unclear so far. METHODS: The recruited with DSAP carried no MVK coding mutations. Exome sequencing was performed in two affected and one unaffected individual in Family 1. Cosegregation of the candidate variants was tested in other family members. Sanger sequencing in 33 individuals with familial DSAP and 19 sporadic DSAP individuals was performed for validating the causative gene. RESULTS: An average of 1.35×10(5) variants were generated from exome data and 133 novel NS/SS/indels were identified as being shared by two affected individuals but absent in the unaffected individual. After functional prediction, 25 possible deleterious variants were identified. In Family 1, a missense variant c.932G>A (p.Arg311Gln) in exon 10 of SLC17A9 was observed in cosegregation with the phenotype; this amino acid substitution was located in a highly conserved major facilitator superfamily (MFS) domain in multiple mammalian. One additional missense variant c.25C>T (p.Arg9Cys) in exon 2 of SLC17A9 was found in Family 2. CONCLUSIONS: The result identified SLC17A9 as another pathogenic gene for DSAP, which suggests a correlation between the aberrant vesicular nucleotide transporter and the pathogenesis of DSAP.

Sequencing-based approach identified three new susceptibility loci for psoriasis.

In a previous large-scale exome sequencing analysis for psoriasis, we discovered seven common and low-frequency missense variants within six genes with genome-wide significance. Here we describe an in-depth analysis of noncoding variants based on sequencing data (10,727 cases and 10,582 controls) with replication in an independent cohort of Han Chinese individuals consisting of 4,480 cases and 6,521 controls to identify additional psoriasis susceptibility loci. We confirmed four known psoriasis susceptibility loci (IL12B, IFIH1, ERAP1 and RNF114; 2.30 × 10(-20)≤P≤2.41 × 10(-7)) and identified three new susceptibility loci: 4q24 (NFKB1) at rs1020760 (P=2.19 × 10(-8)), 12p13.3 (CD27-LAG3) at rs758739 (P=4.08 × 10(-8)) and 17q12 (IKZF3) at rs10852936 (P=1.96 × 10(-8)). Two suggestive loci, 3p21.31 and 17q25, are also identified with P<1.00 × 10(-6). The results of this study increase the number of confirmed psoriasis risk loci and provide novel insight into the pathogenesis of psoriasis.

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.

Genetic variants at 20p11 confer risk to androgenetic alopecia in the Chinese Han population.

BACKGROUND: Androgenetic alopecia (AGA) is a well-characterized type of progressive hair loss commonly seen in men, with different prevalences in different ethnic populations. It is generally considered to be a polygenic heritable trait. Several susceptibility genes/loci, such as AR/EDA2R, HDAC9 and 20p11, have been identified as being involved in its development in European populations. In this study, we aim to validate whether these loci are also associated with AGA in the Chinese Han population. METHODS: We genotyped 16 previously reported single nucleotide polymorphisms (SNPs) with 445 AGA cases and 546 healthy controls using the Sequenom iPlex platform. The trend test was used to evaluate the association between these loci and AGA in the Chinese Han population. Conservatively accounting for multiple testing by the Bonferroni correction, the threshold for statistical significance was P ≤ 3.13 × 10(-3). RESULTS: We identified that 5 SNPs at 20p11 were significantly associated with AGA in the Chinese Han population (1.84 × 10(-11) ≤ P ≤ 2.10 × 10(-6)). CONCLUSIONS: This study validated, for the first time, that 20p11 also confers risk for AGA in the Chinese Han population and implicated the potential common genetic factors for AGA shared by both Chinese and European populations.

Association study confirmed susceptibility loci with keloid in the Chinese Han population.

Keloid is benign fibroproliferative dermal tumors with unknown etiology. Recently, a genome-wide association study (GWAS) in Japanese population has identified 3 susceptibility loci (rs873549 at 1q41, rs940187 and rs1511412 at 3q22.3, rs8032158 at 15p21.3) for keloid. In order to examine whether these susceptibility loci are associated with keloid in the Chinese Han population, twelve previously reported SNPs were selected for replication in 714 cases and 2,944 controls by using Sequenom MassArray system. We found three SNPs in two regions showed significant association with keloid in the Chinese Han population: 1q41 (rs873549, P = 3.03×10(-33), OR = 2.05, 95% CI: 1.82-2.31 and rs1442440, P = 9.85×10(-18), OR = 0.56, 95% CI: 0.49-0.64, respectively) and 15q21.3 (rs2271289 located in NEDD4, P = 1.02×10(-11), OR = 0.66, 95% CI: 0.58-0.74). We also detected one risk haplotype AG (P = 1.36×10(-31), OR = 2.02) and two protective haplotypes of GA and AA (GA, P = 1.94×10(-19), OR = 0.53, AA, P = 0.00043, OR = 0.78, respectively) from the two SNPs (rs873549 and rs1442440). Our study confirmed two previously reported loci 1q41 and 15q21.3 for keloid in the Chinese Han population, which suggested the common genetic factor predisposing to the development of keloid shared by the Chinese Han and Japanese populations.