Dysregulation of long non-coding RNAs in Takayasu arteritis: A proof-of-concept study.

Takayasu arteritis (TAK) is a rare systemic vasculitis primarily affecting the aorta and its major branches. Early diagnosis is critical to prevent severe vascular complications, yet current biomarkers are insufficient. This proof-of-concept study explores the potential of long non-coding RNAs (lncRNAs) in TAK, an area largely unexplored. In this cross-sectional study, 53 TAK patients, 53 healthy controls, and 10 rheumatoid arthritis (RA) patients were enrolled. Clinical evaluations, disease activity assessments, and lncRNA expression levels were analyzed. TAK patients exhibited significant dysregulation in several lncRNAs, including THRIL (19.4, 11.1-48.8 vs. 62.5, 48.6-91.4 arbitrary units [a.u.]; p < 0.0001), HIF1A-AS1 (4.5, 1.8-16.6 vs. 26.5, 19.8-33.7 a.u.; p < 0.0001), MALAT-1 (26.9, 13.8-52.5 vs. 92.1, 58.5-92.1 a.u.; p < 0.0001), and HOTAIR (8.0, 2.5-24.5 vs. 36.0, 30.0-43.8 a.u.; p < 0.0001), compared to healthy controls. Notably, HOTAIR (area under the ROC curve [AUC] = 0.825), HIF1A-AS1 (AUC = 0.820), and THRIL (AUC = 0.781) demonstrated high diagnostic potential with superior specificity (approximately 95%). While lncRNAs showed diagnostic promise, no significant correlations with TAK activity were observed. Comparative analysis with RA patients revealed distinct lncRNA expression patterns. This study unveils significant dysregulation of lncRNAs THRIL, HIF1A-AS1, and HOTAIR in TAK patients, underscoring their potential as biomarkers and opening avenues for further research into the mechanistic roles of these lncRNAs in TAK pathogenesis.

Angiogenesis related genes in Takayasu Arteritis (TAK): robust association with Tag SNPs of IL-18 and FGF-2 in a South Asian Cohort.

We performed genetic association study for genes encoding angiogenic and angiostatic proteins in patients with Takayasu arteritis (TAK). A total of 96 SNPs involving 60 genes were studied. Genotyping was performed in Fluidigm 96.96 Dynamic Array chip. All statistical analysis for SNP evaluation was performed using PLINK software. Initial analyses revealed five SNPs from three genes [IL-18 (encodes Interleukin-18), FGF2 (encodes Fibroblast Growth Factor-2), and ANGPT1 (encodes Angiopoietin-1)] as significantly different between controls and cases (uncorrected p < 0.05). After permutation-based analysis, two tag SNPs on the promoter region of IL-18 (rs187238 and rs1946518) and one 3'UTR tag SNP (rs1476217) of FGF2 were significantly associated with susceptibility to TAK, with p and OR (95% CI) of 0.0006 and 1.64 (1.25-2.17), 0.03 and 1.28 (1.02-1.64) & 0.016 and 1.33 (1.05-1.67), respectively; while, the two tag SNPs of ANGPT1 gene (rs6469101 and rs16875900) showed a trend (p = 0.055 & p = 0.051, respectively after permutation based correction). There is robust linkage disequilibrium between the two tag SNPs of IL-18 gene as validated by 1000 genome data of South Asian population; the eQTL effects of these tag SNPs of IL-18 and FGF2 genes on adjacent genes further suggest that these tag SNPs act as genetic risks for development of TAK in South Asians, with possible functional implications towards future biomarker development. Genotype phenotype study by genetic model-based analysis also revealed associations between genotype subsets and clinical features like fever, visual loss, left subclavian and coronary artery involvement in our TAK patients.

High-throughput sequencing reveals the change of TCR α chain CDR3 with Takayasu arteritis.

OBJECTIVE: Takayasu arteritis (TAK) is an inflammatory disease of blood vessels, and its pathogenesis is not clear at present. In this study, we explored the immunological characteristics of T cell receptor (TCR) α-chain complementarity-determining region 3 (CDR3) in patients with TAK. METHODS: Five untreated patients with TAK were collected from June 2019 to December 2019. Four healthy blood samples were matched as the control group. The blood mononuclear cells were separated, and RNA was extracted for reverse transcription to obtain complementary DNA. Then high-throughput sequencing was performed. The quality of samples was evaluated by principal component analysis. We compared the diversity and expression of TCR α-chain between TAK group and control group. R software was used for statistical analysis and drawing, and Mann-Whitney U test was used to analyze the differences between the two groups. RESULTS: The results showed that there was a significant difference in the diversity of TCR α-chain CDR3 between the two groups. Three V region genes expression significantly higher in the TAK patients than in the control group. A total of 196 VJ rearrangement genes are significantly different between the two groups, of which 149 rearrangement genes in the TAK group are lower than those in the control group, and 47 rearrangement genes in the TAK group are higher than those in the control group. CONCLUSION: Patients with TAK have a unique TCR α-chain CDR3 library. These characteristic genes may be a marker for early diagnosis and provide a new theoretical basis for treating TAK.

Systemic review and meta-analysis of the association between interleukin-10 and Takayasu arteritis.

OBJECTIVE: The aim of this meta-analysis is to investigate the relationship between interleukin (IL)-10 levels and its polymorphism and Takayasu arteritis (TAK). METHODS: Five databases including PubMed, Web of Science, Ovid, Sinomed and China National Knowledge Infrastructure (CNKI) were gone through from inception to March 31, 2022. Studies were screened according to the inclusion and exclusion criteria. Newcastle-Ottawa Scale (NOS) was applied to assess study quality. Strengths of association were evaluated by odds ratio (OR) and 95% CI. The T v. t (allele contrast), TT v. tt (homozygous contrast), Tt vs tt (heterozygous contrast), TT + Tt vs tt (dominant contrast) and TT vs Tt + tt (recessive contrast) models were adopted. RESULTS: Seven studies were included. No significant relationship between IL-10 and TAK was detected in the included patients (P > 0.05). The levels of IL-10 were lower in the active group than those in the stable group, which was -0.47 (95% CI: -0.93, 0.00) (P = 0.05). No significant relationships between IL-10 and TAK were found under all contrasts for polymorphisms rs1800871, rs1800872 and rs1800896 (P > 0.05). CONCLUSIONS: There was no significant difference in IL-10 levels between TAK patients and control subjects. The levels of IL-10 were lower in TAK patients in the active stage. There was no significant association between IL-10 gene polymorphisms and TAK. Further well-designed studies with larger sample sizes in patients with different stages are needed.

Association of Killer Cell Immunoglobulin-like Receptor (KIR) Genes and their HLA Ligands with Susceptibility to Takayasu Arteritis in the Iranian Population.

Takayasu arteritis (TA) is a chronic inflammatory disorder characterized by vascular damage and fibrosis in the intima that commonly occurs in the aorta. In many damaged sites in TA patients, natural killer (NK) cells have been shown to be hyperactivated and produce inflammatory cytokines and toxic components. Killer cell immunoglobulin-like receptors (KIRs) are found on NK cells and interact with human leukocyte antigen (HLA) class I ligands to activate or suppress NK cells. The present study assessed the possible role of KIR and their HLA ligand genes in susceptibility to TA in Iranian patients. This case-control study included 50 TA patients and 50 healthy subjects. DNA was extracted from whole peripheral blood samples, and polymerase chain reaction with sequence-specific primers (PCR-SSP) was performed to recognize the presence or absence of polymorphism in 17 KIR genes and 5 HLA class I ligands in each participant. Among the KIR and HLA genes, a significant decrease was detected in the frequency of 2DS4 (full allele) in TA patients (38%) compared with healthy controls (82%) (OR=0.13, 95% CI=0.05-0.34). However, none of the KIR and HLA genotypes or the interactions between these genes were associated with susceptibility to TA. The KIR2DS4 gene might be involved in the regulation of activation as well as the production of cytotoxic mediators of NK cells in patients with TA.

Coexistence of 3q29 microdeletion syndrome and Takayasu arteritis: A case report.

Takayasu arteritis (TAK) is a rare type of large and medial vessel systemic vasculitis. A variety of factors are thought to play a role in the occurrence and development of TAK such as human leukocyte antigen-B52, autoimmunity, inflammation and environmental factors. 3q29 microdeletion syndrome is also a very rare inherited disease, which includes intellectual disability, growth retardation and neuropsychiatric disorders. Here, we present a case with concomitant TAK and 3q29 microdeletion syndrome. A 22-year-old woman presented to the emergency department with sudden bilateral vision loss and severe headache. During physical examination, the patient was noted to have a difference in blood pressure between extremities. Computed tomography angiography revealed vascular wall inflammation in the abdominal aorta. Based on clinical and radiographical findings, a diagnosis of TAK was made. Concurrently, the patient was found to have short stature and intellectual disability. A possible genetic etiology was sought out. Chromosome analysis showed a 1.5 Mb heterozygous deletion on chromosome 3 and a diagnosis of 3q29 microdeletion was made. Additional imaging also revealed a split cord in medulla spinalis along with hemivertebrae and fusion anomalies, neither of which were reported in TAK or 3q29 microdeletion cases in the literature.

High expression of pro-inflammatory cytokine genes IL-1ß and IL-1R2 upon TLR4 activation in Takayasu arteritis.

Toll-like receptors (TLR) 4 and its endogenous ligands are highly expressed in aorta. In the present study, we have explored the effect of TLR-4 activation by pro-inflammatory and angiogenic factors in PBMCs of patients with Takayasu Arteritis (TA). In the screening cohort, PBMCs of TA (n = 6) and healthy controls (n = 6) were stimulated with LPS and cultured. mRNA expression of 84 genes were quantitated by RT2 Profiler™ PCR Array kit in PBMCs. Validation set of additional PBMCs from TA (n = 7) and healthy controls [HC) (n = 7) were then stimulated with LPS to study expression of selected genes with delta Ct > 0.1 in the screening cohort. Significant gene expressions were correlated with Indian Takayasu arteritis activity scores (ITAS 2010). Increased expression of CCL2 was observed only in unstimulated PBMCs of patients with TA [median relative difference (RD) of 2.37] as compared to HC (RD 1.37, p < 0.03) in validation cohort, while stimulation with TLR4 ligand led to increased mRNA expression of IL-1ß (RD 7.9, p < 0.028) and IL-1R2 (RD 0.08 p < 0.013) genes as compared to that of HC [RD of 5.32 for IL-1ß and 0.01 for IL-1R2, respectively] in validation cohort. TLR4 activation also led to significantly higher expression of HPSE, TIMP1 and low expression of VEGFB, S1PR1, SERPINF1, ANGPLT4, ANGPT2, TIE1 and NOS3 genes in the screening cohort. But expression of VEGFB was not significant in validation cohort. The significant gene expressions, however, did not correlate with ITAS [ITAS2010 and ITAS-A (CRP)]. TLR4 activation leads to increased expression of IL-1ß and IL-1R2 genes in PBMCs of patients with TA.

Using the co-expression network of T cell-activation-related genes to assess the disease activity in Takayasu's arteritis patients.

BACKGROUND: There have been lacking reliable serum biomarkers in assessing the disease activity of Takayasu's arteritis (TAK). This study aimed to assess the disease activity of TAK by assayed gene expression levels in peripheral mononuclear cells (PBMCs). METHODS: The expression level of genes that essential in T cell activation in PBMCs in active TAK patients, inactive TAK patients, and healthy controls were detected by real-time fluorescence quantitative polymerase chain reaction, including TCR, CD28, CD40, CD40L, PD-1, PD-L1, PD-L2, CTLA4, TIGIT, TIM3, LAG3, CCL5, T-bet, RORC, and FOXP3. Gene co-expression network was established, and the signature of the topology structure in active TAK patients compared to the inactive TAK patients were extracted and described by formulas. Respectively, the disease activity was assessed by the routine serum biomarkers, including ESR, CRP, IL-6, and TNF-α, the gene expression level of TCR, CD28, T-bet, and RORC, as well as the signature of the topology structure, and the diagnostic efficacies were compared. RESULTS: Compared with the inactive TAK patient group, the active TAK patient group had a greater clustering coefficient in the network consisting of genes that essential in T cell activation. When assessing the disease activity used this signature of topology structure, the sensitivity was 90.9%, the specificity was 100%, and the AUC was 0.98, which was greater than the AUCs of these biomarkers. CONCLUSIONS: The signature of the topology structure could distinguish the active TAK patients from inactive TAK patients. This maybe is a novel evaluation algorithm of disease activity.

Comprehensive Analysis of the HLA Class I and the HLA Class II Alleles in Patients with Takayasu Arteritis: Relationship with Clinical Patterns and Prognosis

BACKGROUND: Takayasu arteritis (TA) is a systemic vasculitis, affecting mainly the aorta and its branches. OBJECTIVE: To analyze the HLA class I and class II alleles in patients with TA and explore their relationship with clinical and demographic characteristics, and potential significance in prognosis. METHODS: Twenty-five, unrelated TA patients were genotyped for HLA-A, HLA-B, HLA-C, HLA-DRB1, and the HLA-DQB1 loci. The frequencies of the HLA-A, HLA-B, and the HLA-DRB1 were compared with a control group of 1992, while the HLA-C and the HLA-DQB1 were compared with a group of 159 healthy, unrelated individuals. RESULTS: Among TA patients, 5/25 (20%) were identified as the HLA-B*52 carriers. There was a significant difference in the HLA-B*52 allele frequency in the TA patients (10%) compared with the healthy controls (1.2%). Moreover, presence of the HLA-B*52 was associated with significantly earlier disease onset, more severe clinical presentations, and a poorer response to treatment. The HLA-C*03 was detected in 32% of patients and was present exclusively in those with a clinically mild form of the TA, indicating a putative protective effect. CONCLUSION: These findings indicate that the HLA-B*52 allele contributes to a higher susceptibility to the TA whereas the HLA-C*03, can be a protective factor in the TA.

A susceptibility locus in the IL12B but not LILRA3 region is associated with vascular damage in Takayasu arteritis.

HLA-B*52 is an established genetic factor in Takayasu arteritis (TAK). Recently, single nucleotide polymorphisms (SNPs) in IL12B (rs6871626) and LILRA3 (rs103294) were newly identified as non-HLA susceptibility loci in TAK. Here, we examined how these SNPs contribute to clinical characteristics and vascular damage in TAK. We retrospectively reviewed the medical records of 99 TAK patients enrolled in our previous genome-wide association study, and whose genotypes for IL12B rs6871626, LILRA3 rs103294, and HLA-B*52 were available. Incidence of aortic regurgitation (AR) was significantly associated with the A allele (risk allele) of IL12B rs6871626 (CC 42%, AC 61%, AA 81%; p = 0.0052; odds ratio [OR] 2.45), as well as with the incidence of hypertension (p = 0.049; OR 1.82) and the proportion of patients who underwent aortic valve replacement (p = 0.023; OR 3.64). Regarding vascular damage, there was positive correlation between the Takayasu Arteritis Damage Score and the A allele of IL12B rs6871626 (CC 3.42 ± 2.71, AC 4.06 ± 3.25, AA 6.00 ± 2.81; p = 0.0035; ß = 1.35) and between the Vasculitis Damage Index and the A allele (CC 3.47 ± 1.98, AC 4.33 ± 2.40, AA 5.37 ± 2.22; p = 0.0054; ß = 0.96). Contrarily, no correlation was found between LILRA3 rs103294 and vascular damage. In the present study, IL12B rs6871626 was associated with vascular damage in TAK, whereas LILRA3 rs103294 was not. Genotyping of IL12B rs6871626 may help to identify patients at risk of disease progression.

Polymorphisms in TNFAIP3, but not in STAT4, BANK1, BLK, and TNFSF4, are associated with susceptibility to Takayasu arteritis.

BACKGROUND: Takayasu arteritis (TAK) is considered a rare disease characterized by nonspecific inflammation of the large arteries, especially the aorta and its major branches. Because TAK is an autoimmune disease (AD), it could share susceptibility loci with other pathologies such as systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA), among others. Widely explored polymorphisms in non-HLA genes, including TNFAIP3, STAT4, TNFSF4, BANK1, and BLK have been consistently associated with both SLE and RA, but they have not been evaluated in TAK. OBJECTIVE: The aim of our study was to investigate whether TNFAIP3, STAT4, BANK1, BLK, and TNFSF4 polymorphisms are associated with susceptibility to TAK. METHODS: The TNFAIP3 rs2230926T/G and rs5029924C/T, STAT4 rs7574865G/T, BANK1 10516487G/A, BLK rs2736340T/C, rs13277113A/G, and TNFS4 rs2205960G/T polymorphisms were genotyped in 101 cases and 276 controls by using a TaqMan SNP genotyping assay. An association analysis was performed. RESULTS: The TNFAIP3 rs2230926T/G and rs5029924C/T polymorphisms were in complete linkage disequilibrium and turned out to be risk factors for TAK (OR = 4.88, p = 0.0001). The STAT4, BANK1, BLK, and TNFSF4 polymorphisms were not associated with the disease. CONCLUSIONS: This is the first study documenting an association of TNFAIP3 rs2230926T/G and rs5029924C/T with TAK. Our results provide new information on the genetic bases of TAK.

Specific Follicular Helper T Cell Signature in Takayasu Arteritis.

OBJECTIVE: Our aim was to compare transcriptome and phenotype profiles of CD4+ T cells and CD19+ B cells in patients with Takayasu arteritis (TAK), patients with giant cell arteritis (GCA), and healthy donors. METHODS: Gene expression analyses, flow cytometry immunophenotyping, T cell receptor (TCR) gene sequencing, and functional assessments of cells from peripheral blood and arterial lesions from TAK patients, GCA patients, and healthy donors were performed. RESULTS: Among the most significantly dysregulated genes in CD4+ T cells of TAK patients compared to GCA patients (n = 720 genes) and in CD4+ T cells of TAK patients compared to healthy donors (n = 1,447 genes), we identified a follicular helper T (Tfh) cell signature, which included CXCR5, CCR6, and CCL20 genes, that was transcriptionally up-regulated in TAK patients. Phenotypically, there was an increase in CD4+CXCR5+CCR6+CXCR3- Tfh17 cells in TAK patients that was associated with a significant enrichment of CD19+ B cell activation. Functionally, Tfh cells helped B cells to proliferate, differentiate into memory cells, and secrete IgG antibodies. Maturation of B cells was inhibited by JAK inhibitors. Locally, in areas of arterial inflammation, we found a higher proportion of tertiary lymphoid structures comprised CD4+, CXCR5+, programmed death 1+, and CD20+ cells in TAK patients compared to GCA patients. CD4+CXCR5+ T cells in the aortas of TAK patients had an oligoclonal α/ß TCR repertoire. CONCLUSION: We established the presence of a specific Tfh cell signature in both circulating and aorta-infiltrating CD4+ T cells from TAK patients. The cooperation of Tfh cells and B cells might be critical in the occurrence of vascular inflammation in patients with TAK.

Identification of susceptibility loci for Takayasu arteritis through a large multi-ancestral genome-wide association study.

Takayasu arteritis is a rare inflammatory disease of large arteries. We performed a genetic study in Takayasu arteritis comprising 6,670 individuals (1,226 affected individuals) from five different populations. We discovered HLA risk factors and four non-HLA susceptibility loci in VPS8, SVEP1, CFL2, and chr13q21 and reinforced IL12B, PTK2B, and chr21q22 as robust susceptibility loci shared across ancestries. Functional analysis proposed plausible underlying disease mechanisms and pinpointed ETS2 as a potential causal gene for chr21q22 association. We also identified >60 candidate loci with suggestive association (p < 5 × 10-5) and devised a genetic risk score for Takayasu arteritis. Takayasu arteritis was compared to hundreds of other traits, revealing the closest genetic relatedness to inflammatory bowel disease. Epigenetic patterns within risk loci suggest roles for monocytes and B cells in Takayasu arteritis. This work enhances understanding of the genetic basis and pathophysiology of Takayasu arteritis and provides clues for potential new therapeutic targets.

Association of interleukin-18 gene polymorphisms with Takayasu arteritis in a Chinese Han population.

BACKGROUND: Interleukin-18 (IL18) gene polymorphisms are related to many inflammatory and autoimmune diseases. However, a correlation analysis between IL18 -607C/A and -137G/C gene polymorphisms and Takayasu arteritis (TA) is lacking. METHODS: This study enrolled 200 patients with TA as the case group and 334 region-, age-, and sex-matched healthy subjects as the control group. We genotyped alleles and genotypes at positions -607 and -137 of the IL18 gene and analyzed the distribution frequencies. Mann-Whitney U test, t test, Chi-squared test and Hardy-Weinberg equilibrium were performed. RESULTS: After adjusting for risk factors, the adjusted odds ratios and 95% confidence intervals at position -607C/A were 0.533, 0.391 to 0.880 (P = 0.010); 0.266, 0.586 to 1.002 (P = 0.051); and 0.122, 0.552 to 1.420 (P = 0.613) under the dominant, additive, and recessive models, respectively. For the -137G/C polymorphism, the adjusted odds ratios and 95% confidence intervals were 1.571, 1.068 to 2.311 (P = 0.022); 1.467, 1.086 to 1.980 (P = 0.012); and 1.815, 0.901 to 3.656 (P = 0.095) under the dominant, additive, and recessive models, respectively. Moreover, regardless of the model used, we found no statistical difference in distribution frequency between the active and quiescent states of TA for the -607C/A (P = 0.355, 0.631, and 0.705, respectively) and -137G/C polymorphisms (P = 0.205, 0.385, and 0.208, respectively). CONCLUSIONS: The IL18 -607C/A gene polymorphism may decrease the risk of TA, and thus is a protective factor, whereas -137G/C may increase the risk of TA, and thus is a risk factor. However, neither polymorphism was related to activity (active vs. quiescent) of TA.

X-linked inhibitor of apoptosis protein deficiency complicated with Crohn's disease-like enterocolitis and Takayasu arteritis: A case report.

X-linked inhibitor of apoptosis protein (XIAP) deficiency results in monogenic inflammatory bowel disease. To date, no vasculitis associated with XIAP deficiency has been reported. A 10-year-old boy was diagnosed with Crohn's disease and he responded poorly to conventional treatment for Crohn's disease. He was dependent on corticosteroids and parenteral nutrition. To manage severe colitis, he underwent ileostomy followed by ileocolectomy for an ileo-sigmoid fistula. At the age of 15 years, he developed IgA vasculitis and at the age of 17 years, he developed refractory Takayasu arteritis (TAK), which was resistant to corticosteroid and immunosuppressive therapy. Whole-exome sequencing revealed a novel mutation of the splice acceptor site in XIAP (c.1057-1G > A) at the age of 19 years. Allogeneic hematopoietic stem cell transplantation was successful with subsequent withdrawal of intensive immunosuppressive therapy and clinical remission of both enterocolitis and TAK. This case suggests that patients with XIAP deficiency could develop intractable inflammatory disease involving the intestinal tract and blood vessels.

Targeting JAK/STAT pathway in Takayasu's arteritis.

OBJECTIVE: Takayasu's arteritis (TAK) is a large vessel vasculitis with important infiltration of proinflammatory T cells in the aorta and its main branches, but its aetiology is still unknown. Our work aims to explore the involvement of Janus Kinase/Signal Transducers and Activators of Transcription (JAK/STAT) signalling pathway in proinflammatory T cells differentiation and disease activity of TAK. METHODS: We analysed transcriptome and interferons gene signatures of fluorescence-activated cell sorting (FACS-sorted) CD4+ and CD8+ T cells from healthy donors (HD) and in 25 TAK (median age of 37.6 years including 21 active TAK with National Institutes of Health (NIH) score >1). Then we tested, in vitro and in vivo, the effects of JAK inhibitors (JAKinibs) in TAK. RESULTS: Transcriptome analysis showed 248 and 432 significantly dysregulated genes for CD4+ and CD8+ samples between HD and TAK, respectively. Among dysregulated genes, we highlighted a great enrichment for pathways linked to type I and type II interferons, JAK/STAT and cytokines/chemokines-related signalling in TAK. We confirmed by Real Time Reverse Transcription Polymerase Chain Reaction (RT-qPCR) the upregulation of type I interferons gene signature in TAK as compared with HD. JAKinibs induced both in vitro and in vivo a significant reduction of CD25 expression by CD4+ and CD8+ T cells, a significant decrease of type 1 helper T cells (Th1) and Th17 cells and an increase of Tregs cells in TAK. JAKinibs also decreased C reactive protein level, NIH score and corticosteroid dose in TAK patients. CONCLUSIONS: JAK/STAT signalling pathway is critical in the pathogenesis of TAK and JAKinibs may be a promising therapy.

Lack of Association between Cytokine Genetic Polymorphisms in Takayasu's Arteritis in Mexican Patients.

Aim: To investigate the relation between polymorphisms in the interleukin 10 (IL)-10, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-ß and interferon (IFN)-γ genes and Takayasu's arteritis in the Mexican population. Methods: A case-control study was performed to investigate the associations of IL-10, TNF-α, TGF-ß and IFN-γ polymorphisms in a sample of 52 Takayasu's arteritis patients, diagnosed according to the criteria of the American College of Rheumatology and EULAR PRINTO criteria when the patients were under 18 years of age; 60 clinically healthy unrelated Mexican individuals by the 5' exonuclease TaqMan polymerase chain reaction. Polymorphic haplotypes were constructed after linkage disequilibrium analysis. Results: Significant differences were not found in the distribution for genotype and allele frequencies of the polymorphisms studied between healthy controls and Takayasu´s arteritis patients. Likewise, significant associations were not detected in the haplotype analysis with the different genes studied. Conclusions: These findings suggest that the polymorphisms in IL-10, TNF-α, TGF-ß and IFN-γ might not contribute to the susceptibility of Takayasu´s arteritis in the Mexican population.

Takayasu arteritis risk locus in IL6 represses the anti-inflammatory gene GPNMB through chromatin looping and recruiting MEF2-HDAC complex.

OBJECTIVE: Previous work has revealed a genetic association between Takayasu arteritis and a non-coding genetic variant in an enhancer region within IL6 (rs2069837 A/G). The risk allele in this variant (allele A) has a protective effect against chronic viral infection and cancer. The goal of this study was to characterise the functional consequences of this disease-associated risk locus. METHODS: A combination of experimental and bioinformatics tools were used to mechanistically understand the effects of the disease-associated genetic locus in IL6. These included electrophoretic mobility shift assay, DNA affinity precipitation assays followed by mass spectrometry and western blotting, luciferase reporter assays and chromosome conformation capture (3C) to identify chromatin looping in the IL6 locus. Both cell lines and peripheral blood primary monocyte-derived macrophages were used. RESULTS: We identified the monocyte/macrophage anti-inflammatory gene GPNMB,~520 kb from IL6, as a target gene regulated by rs2069837. We revealed preferential recruitment of myocyte enhancer factor 2-histone deacetylase (MEF2-HDAC) repressive complex to the Takayasu arteritis risk allele. Further, we demonstrated suppression of GPNMB expression in monocyte-derived macrophages from healthy individuals with AA compared with AG genotype, which was reversed by histone deacetylase inhibition. Our data show that the risk allele in rs2069837 represses the expression of GPNMB by recruiting MEF2-HDAC complex, enabled through a long-range intrachromatin looping. Suppression of this anti-inflammatory gene might mediate increased susceptibility in Takayasu arteritis and enhance protective immune responses in chronic infection and cancer. CONCLUSIONS: Takayasu arteritis risk locus in IL6 might increase disease susceptibility by suppression of the anti-inflammatory gene GPNMB through chromatin looping and recruitment of MEF2-HDAC epigenetic repressive complex. Our data highlight long-range chromatin interactions in functional genomic and epigenomic studies in autoimmunity.

Takayasu Arteritis: Recent Developments.

PURPOSE OF REVIEW: Takayasu arteritis (TA) is a granulomatous inflammatory disorder that affects large vessels, especially aorta and its proximal branches. Its diagnosis can be extremely challenging due to the non-specificity of the systemic inflammatory manifestations during the early phase of the disease and usually follows an insidious clinical course until the emergence of vascular ischemic complications. RECENT FINDINGS: Its pathogenesis has been better delineated in recent years, especially the role of HLA-B*52 allele in certain ethnic groups, as well as the use of biological therapy, and surgical revascularization. Recent findings are discussed in depth. Clinical and epidemiological aspects of TA, recent developments in pathogenesis, and therapy are presented.