Preferential binding to elk-1 by sle-associated il10 risk allele upregulates il10 expression

Immunoregulatory cytokine interleukin-10 (IL-10) is elevated in sera from patients with systemic lupus erythematosus (SLE) correlating with disease activity. The established association of IL10 with SLE and other autoimmune diseases led us to fine map causal variant(s) and to explore underlying mechanisms. We assessed 19 tag SNPs, covering the IL10 gene cluster including IL19, IL20 and IL24, for association with SLE in 15,533 case and control subjects from four ancestries. The previously reported IL10 variant, rs3024505 located at 1 kb downstream of IL10, exhibited the strongest association signal and was confirmed for association with SLE in European American (EA) (P = 2.7×10−8, OR = 1.30), but not in non-EA ancestries. SNP imputation conducted in EA dataset identified three additional SLE-associated SNPs tagged by rs3024505 (rs3122605, rs3024493 and rs3024495 located at 9.2 kb upstream, intron 3 and 4 of IL10, respectively), and SLE-risk alleles of these SNPs were dose-dependently associated with elevated levels of IL10 mRNA in PBMCs and circulating IL-10 protein in SLE patients and controls. Using nuclear extracts of peripheral blood cells from SLE patients for electrophoretic mobility shift assays, we identified specific binding of transcription factor Elk-1 to oligodeoxynucleotides containing the risk (G) allele of rs3122605, suggesting rs3122605 as the most likely causal variant regulating IL10 expression. Elk-1 is known to be activated by phosphorylation and nuclear localization to induce transcription. Of interest, phosphorylated Elk-1 (p-Elk-1) detected only in nuclear extracts of SLE PBMCs appeared to increase with disease activity. Co-expression levels of p-Elk-1 and IL-10 were elevated in SLE T, B cells and monocytes, associated with increased disease activity in SLE B cells, and were best downregulated by ERK inhibitor. Taken together, our data suggest that preferential binding of activated Elk-1 to the IL10 rs3122605-G allele upregulates IL10 expression and confers increased risk for SLE in European Americans

Preferential Binding to Elk-1 by SLE-Associated IL10 Risk Allele Upregulates IL10 Expression

Immunoregulatory cytokine interleukin-10 (IL-10) is elevated in sera from patients with systemic lupus erythematosus (SLE) correlating with disease activity. The established association of IL10 with SLE and other autoimmune diseases led us to fine map causal variant(s) and to explore underlying mechanisms. We assessed 19 tag SNPs, covering the IL10 gene cluster including IL19, IL20 and IL24, for association with SLE in 15,533 case and control subjects from four ancestries. The previously reported IL10 variant, rs3024505 located at 1 kb downstream of IL10, exhibited the strongest association signal and was confirmed for association with SLE in European American (EA) (P = 2.7×10-8, OR = 1.30), but not in non-EA ancestries. SNP imputation conducted in EA dataset identified three additional SLE-associated SNPs tagged by rs3024505 (rs3122605, rs3024493 and rs3024495 located at 9.2 kb upstream, intron 3 and 4 of IL10, respectively), and SLE-risk alleles of these SNPs were dose-dependently associated with elevated levels of IL10 mRNA in PBMCs and circulating IL-10 protein in SLE patients and controls. Using nuclear extracts of peripheral blood cells from SLE patients for electrophoretic mobility shift assays, we identified specific binding of transcription factor Elk-1 to oligodeoxynucleotides containing the risk (G) allele of rs3122605, suggesting rs3122605 as the most likely causal variant regulating IL10 expression. Elk-1 is known to be activated by phosphorylation and nuclear localization to induce transcription. Of interest, phosphorylated Elk-1 (p-Elk-1) detected only in nuclear extracts of SLE PBMCs appeared to increase with disease activity. Co-expression levels of p-Elk-1 and IL-10 were elevated in SLE T, B cells and monocytes, associated with increased disease activity in SLE B cells, and were best downregulated by ERK inhibitor. Taken together, our data suggest that preferential binding of activated Elk-1 to the IL10 rs3122605-G allele upregulates IL10 expression and confers increased risk for SLE in European Americans.Peer Reviewe

Preferential Binding to Elk-1 by SLE-Associated <i>IL10</i> Risk Allele Upregulates <i>IL10</i> Expression

<div><p>Immunoregulatory cytokine interleukin-10 (IL-10) is elevated in sera from patients with systemic lupus erythematosus (SLE) correlating with disease activity. The established association of <i>IL10</i> with SLE and other autoimmune diseases led us to fine map causal variant(s) and to explore underlying mechanisms. We assessed 19 tag SNPs, covering the <i>IL10</i> gene cluster including <i>IL19</i>, <i>IL20</i> and <i>IL24</i>, for association with SLE in 15,533 case and control subjects from four ancestries. The previously reported <i>IL10</i> variant, rs3024505 located at 1 kb downstream of <i>IL10</i>, exhibited the strongest association signal and was confirmed for association with SLE in European American (EA) (<i>P</i> = 2.7×10⁻⁸, OR = 1.30), but not in non-EA ancestries. SNP imputation conducted in EA dataset identified three additional SLE-associated SNPs tagged by rs3024505 (rs3122605, rs3024493 and rs3024495 located at 9.2 kb upstream, intron 3 and 4 of <i>IL10</i>, respectively), and SLE-risk alleles of these SNPs were dose-dependently associated with elevated levels of <i>IL10</i> mRNA in PBMCs and circulating IL-10 protein in SLE patients and controls. Using nuclear extracts of peripheral blood cells from SLE patients for electrophoretic mobility shift assays, we identified specific binding of transcription factor Elk-1 to oligodeoxynucleotides containing the risk (G) allele of rs3122605, suggesting rs3122605 as the most likely causal variant regulating <i>IL10</i> expression. Elk-1 is known to be activated by phosphorylation and nuclear localization to induce transcription. Of interest, phosphorylated Elk-1 (p-Elk-1) detected only in nuclear extracts of SLE PBMCs appeared to increase with disease activity. Co-expression levels of p-Elk-1 and IL-10 were elevated in SLE T, B cells and monocytes, associated with increased disease activity in SLE B cells, and were best downregulated by ERK inhibitor. Taken together, our data suggest that preferential binding of activated Elk-1 to the <i>IL10</i> rs3122605-G allele upregulates <i>IL10</i> expression and confers increased risk for SLE in European Americans.</p></div

Preferential Binding to Elk-1 by SLE-Associated IL10 Risk Allele Upregulates IL10 Expression

Immunoregulatory cytokine interleukin-10 (IL-10) is elevated in sera from patients with systemic lupus erythematosus (SLE) correlating with disease activity. The established association of IL10 with SLE and other autoimmune diseases led us to fine map causal variant(s) and to explore underlying mechanisms. We assessed 19 tag SNPs, covering the IL10 gene cluster including IL19, IL20 and IL24, for association with SLE in 15,533 case and control subjects from four ancestries. The previously reported IL10 variant, rs3024505 located at 1 kb downstream of IL10, exhibited the strongest association signal and was confirmed for association with SLE in European American (EA) (P = 2.7x10(-8), OR = 1.30), but not in non-EA ancestries. SNP imputation conducted in EA dataset identified three additional SLE-associated SNPs tagged by rs3024505 (rs3122605, rs3024493 and rs3024495 located at 9.2 kb upstream, intron 3 and 4 of IL10, respectively), and SLE-risk alleles of these SNPs were dose-dependently associated with elevated levels of IL10 mRNA in PBMCs and circulating IL-10 protein in SLE patients and controls. Using nuclear extracts of peripheral blood cells from SLE patients for electrophoretic mobility shift assays, we identified specific binding of transcription factor Elk-1 to oligodeoxynucleotides containing the risk (G) allele of rs3122605, suggesting rs3122605 as the most likely causal variant regulating IL10 expression. Elk-1 is known to be activated by phosphorylation and nuclear localization to induce transcription. Of interest, phosphorylated Elk-1 (p-Elk-1) detected only in nuclear extracts of SLE PBMCs appeared to increase with disease activity. Co-expression levels of p-Elk-1 and IL-10 were elevated in SLE T, B cells and monocytes, associated with increased disease activity in SLE B cells, and were best downregulated by ERK inhibitor. Taken together, our data suggest that preferential binding of activated Elk-1 to the IL10 rs3122605-G allele upregulates IL10 expression and confers increased risk for SLE in European Americans.Support for this work was provided by the US National Institutes of Health grants: R01AR043814 (BPT), P30AR48311 (EEB), R01CA141700 and RC1AR058621 (MEAR), P01AI083194 (JBH KMS RPK LAC TJV MEAR COJ BPT PMG), P01AR049084 (RPK JBH EEB JCE RRG LMV MAP), R01AR33062 (RPK), K24AR002138, P602AR30692 and UL1RR025741 (RRG), R01AR43727 (MAP), P01AR052915 and U01AI090909 (JDR), R01AR057172 (COJ), R01AI063274 and RC2AR058959 (PMG), R01AR043274 (KMS), P30AR053483, P30GM103510, U19AI082714 and U01AI101934 (JAJ), P60AR049459 and UL1RR029882 (GSG DLK), K08AI083790, L30AI071651 and UL1RR024999 (TBN), P60AR053308 and UL1TR000004 (LAC), R01AR051545-01A2 (AMS), R21AI070304 (SAB), and 1R01AR054459 (CYY). Additional support was provided by the Lupus Research Institute grant (BPT); the Alliance for Lupus Research grants (BPT YD KMS TBN LAC COJ); the U.S. Department of Defense PR094002 and the US Department of Veterans Affairs Merit Award (JBH); the Arthritis National Research Foundation Eng Tan Scholar Award (TBN JZ); Charles Barkley Research Award (EEB); the Korea Healthcare Technology R&amp;D Project, Ministry for Health and Welfare, Republic of Korea (A120404; SCB); funding from the Swedish Research Council of Medicine (MEAR); the Arthritis Research UK (TJV); the Arthritis Foundation (AMS PMG); Clinical and Translational Science Grant Number UL1RR025014-02 (AMS), UL1TR000165 (JCE) and UL1RR025005 (MAP) from the National Center for Advancing Translational Sciences (NCATS) and National Center for Research Resources (NCRR) component of the National Institutes of Health (NIH); Kirkland Scholar Award (LAC); the Federico Wilhelm Agricola Foundation Research grant (BAPE); Wake Forest University Health Sciences Center for Public Health Genomics (CDL); the Korean Research and Development Program of MKE/KEIT (10035615; YWS); and UCLA Clinical and Translational Science Institute (CTSI) grants: UL1RR033176 and UL1TR000124. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript