Association analysis of BANK1 gene with psoriasis in Southern Han Chinese

Connection of BANK1, Tolerance, Regulatory B cells, and Apoptosis: Perspectives of a Reductionist Investigation

BANK1 transcript is upregulated in whole blood after kidney transplantation in tolerant patients. In comparison to patients with rejection, tolerant patients display higher level of regulatory B cells (Bregs) expressing granzyme B (GZMB⁺) that have the capability to prevent effector T cells proliferation. However, BANK1 was found to be decreased in these GZMB⁺ Bregs. In this article, we investigated seven different transcriptomic studies and mined the literature in order to make link between BANK1, tolerance and Bregs. As for GZMB⁺ Bregs, we found that BANK1 was decreased in other subtypes of Bregs, including IL10⁺ and CD24^hiCD38^hi transitional regulatory B cells, along with BANK1 was down-regulated in activated/differentiated B cells, as in CD40-activated B cells, in leukemia and plasma cells. Following a reductionist approach, biological concepts were extracted from BANK1 literature and allowed us to infer association between BANK1 and immune signaling pathways, as STAT1, FcγRIIB, TNFAIP3, TRAF6, and TLR7. Based on B cell signaling literature and expression data, we proposed a role of BANK1 in B cells of tolerant patients that involved BCR, IP3R, and PLCG2, and a link with the apoptosis pathways. We confronted these data with our experiments on apoptosis in total B cells and Bregs, and this suggests different involvement for BANK1 in these two cells. Finally, we put in perspective our own data with other published data to hypothesize two different roles for BANK1 in B cells and in Bregs.

Association between the BANK1 rs3733197 polymorphism and polymyositis/dermatomyositis in a Chinese Han population

The aim of our study was to investigate the association between single nucleotide polymorphisms (SNPs) in the BANK1 gene and polymyositis/dermatomyositis (PM/DM) in a Chinese Han population. In total, 363 PM patients, 654 DM patients, and 1280 healthy controls were recruited and genotyped using the Sequenom MassArray system. A significant allele association was observed in rs3733197 among the PM/DM patients (OR 0.81, 95%CI 0.70-0.94, Pc = 1.83 × 10^-2). Notably, rs3733197 was associated with DM and PM/DM patients with ILD involvement (Pc = 0.026; Pc = 6.0 × 10^-3, respectively). However, no statistically significant difference was observed in the allele or genotype frequencies of three SNPs (rs4522865, rs17266594, and rs10516487) among the DM, PM, and PM/DM patients and healthy controls (all Pc > 0.05). This study was the first to demonstrate that a BANK1 gene SNP (rs3733197) could confer genetic predisposition in PM/DM patients and PM/DM patients with ILD in a Chinese Han population.

Polymorphisms Associated with Age at Onset in Patients with Moderate-to-Severe Plaque Psoriasis

Psoriasis is a chronic skin disease in which genetics play a major role. Although many genome-wide association studies have been performed in psoriasis, knowledge of the age at onset remains limited. Therefore, we analyzed 173 single-nucleotide polymorphisms in genes associated with psoriasis and other autoimmune diseases in patients with moderate-to-severe plaque psoriasis type I (early-onset, <40 years) or type II (late-onset, ≥40 years) and healthy controls. Moreover, we performed a comparison between patients with type I psoriasis and patients with type II psoriasis. Our comparison of a stratified population with type I psoriasis (n = 155) and healthy controls (N = 197) is the first to reveal a relationship between the CLMN, FBXL19, CCL4L, C17orf51, TYK2, IL13, SLC22A4, CDKAL1, and HLA-B/MICA genes. When we compared type I psoriasis with type II psoriasis (N = 36), we found a significant association between age at onset and the genes PSORS6, TNF-α, FCGR2A, TNFR1, CD226, HLA-C, TNFAIP3, and CCHCR1. Moreover, we replicated the association between rs12191877 (HLA-C) and type I psoriasis and between type I and type II psoriasis. Our findings highlight the role of genetics in age of onset of psoriasis.

Multiple Changes of Gene Expression and Function Reveal Genomic and Phenotypic Complexity in SLE-like Disease

The complexity of clinical manifestations commonly observed in autoimmune disorders poses a major challenge to genetic studies of such diseases. Systemic lupus erythematosus (SLE) affects humans as well as other mammals, and is characterized by the presence of antinuclear antibodies (ANA) in patients’ sera and multiple disparate clinical features. Here we present evidence that particular sub-phenotypes of canine SLE-related disease, based on homogenous (ANA^H) and speckled ANA (ANA^S) staining pattern, and also steroid-responsive meningitis-arteritis (SRMA) are associated with different but overlapping sets of genes. In addition to association to certain MHC alleles and haplotypes, we identified 11 genes (WFDC3, HOMER2, VRK1, PTPN3, WHAMM, BANK1, AP3B2, DAPP1, LAMTOR3, DDIT4L and PPP3CA) located on five chromosomes that contain multiple risk haplotypes correlated with gene expression and disease sub-phenotypes in an intricate manner. Intriguingly, the association of BANK1 with both human and canine SLE appears to lead to similar changes in gene expression levels in both species. Our results suggest that molecular definition may help unravel the mechanisms of different clinical features common between and specific to various autoimmune disease phenotypes in dogs and humans.

Autoimmune disorders display complex phenotypes with clinically diverse manifestations, which together with complex genetic inheritance and environmental factors triggering the disease may complicate the diagnosis and investigation of the disease mechanism. The use of dog breeds may facilitate the analysis of genetic factors based on genetic homogeneity within a breed. We performed genetic analysis of two diseases common in dogs, immune-mediated rheumatic disease (IMRD) and steroid-responsive meningitis-arteritis (SRMA) that are similar to human SLE and a group of vasulitides such as Kawasaki disease, Henoch-Schönlein purpura and Behçet’s disease, correspondingly. We identified eleven genes along with specific alleles and genotypes for the major histocompatibility complex II involved in susceptibility, and studied their expression. The genes shared between the two diseases may be involved in the common immune signaling pathways and hence account for the common clinical signs, whereas the phenotype-specific genes may be implicated in particular pathways active in certain tissues and organs, and thereby may be responsible for characteristic manifestations seen only in one of the diseases. Further, the similarity between human and dog SLE at the genetic and functional levels demonstrated by the association of the BANK1 gene in both species indicates the common cross-species mechanisms of autoimmunity and may help identification of novel disease genes and pathways.

A nonsynonymous SNP in BANK1 is associated with serum LDL cholesterol levels in three Korean populations

Serum levels of lipids, such as cholesterol and triglycerides, are heritable risk factors for cardiovascular disease and targets for therapeutic intervention. Because previous genome-wide association studies (GWASs) did not target functional genetic variants, we employed an alternate approach using nonsynonymous single-nucleotide polymorphisms (SNPs) to identify functional genetic variants associated with the regulation of serum lipid levels. We selected 3667 healthy individuals from a rural community-based cohort (CAVAS; Cardio Vascular disease Association Study) of the Korean Genome and Epidemiology Study project. We analyzed demographic and lifestyle information, lipid measurements and genotypes using the Illumina-1M SNP chip. For genotyping, we isolated 11 558 nonsynonymous SNPs and conducted a linear regression analysis with four lipid traits (total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterols and triglycerides). Significantly associated SNPs were validated in two independent Korean populations, Korean Association Resource (KARE) (n=4116) and Health Examinee (HEXA) (n=2178). Of the 11 558 SNPs, one SNP (rs3733197) from the CAVAS was significantly associated with serum LDL cholesterols (beta±s.e.=4.67±0.94, P-value=1.0 × 10(-6 and) Bonferroni corrected P-value=0.012). The replication results of HEXA and KARE were beta±s.e.=2.88±1.12, P-value=0.016 and beta±s.e.=1.26±0.97, P-value=0.196, respectively. An overall meta-analysis of the three data sets revealed beta=2.98±0.57, P-value=6.19 × 10(-7). The rs3733197 is located in the coding region of BANK1 (B-cell scaffold protein with ankyrin repeats 1), and the minor allele (A) resulted in the replacement of the Alanine at position 383 with Threonine.