Supplementary Material for: A Functional Polymorphism in the Promoter Region of TLR3 Is Associated with Susceptibility to End-Stage Renal Disease

<b><i>Background/Aims:</i></b> End-stage renal disease (ESRD) is simultaneously associated with immune activation, systemic inflammation and immune deficiency. Toll-like receptor 3 (TLR3), a receptor for viral double-stranded RNA, is involved in immune cell activation in renal diseases and may contribute to chronic inflammatory disease progression. To date, effects of <i>TLR3</i> polymorphisms on ESRD remain unknown. Therefore, we determined the predictive value of <i>TLR3</i> polymorphisms and further functionally studied ESRD. <b><i>Methods:</i></b> We performed a case-control association study and genotyped 616 ESRD patients and 813 healthy controls. Patients were genotyped for -7C/A, 1377C/T and 1234C/T polymorphisms of <i>TLR3 </i>using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The Haplotype association analysis was performed using the Haploview package. A luciferase reporter assay and real-time PCR were used to test the function of the -7C/A promoter polymorphism in TLR3 expression in human embryonic kidney 293 (HEK293) cells. <b><i>Results:</i></b> Genotype distributions of -7C/A and 1377C/T in TLR3 were significantly different in ESRD patients and healthy controls. The ATC haplotype of TLR3 was associated with a decreased risk of ESRD. We also found significant differences in TLR3 expression by dexamethasone treatment between various genotypes of -7C/A (p = 0.02). TLR3 transcriptional activity of the variant -7 C allele was higher than that of the -7 A allele after dexamethasone treatment. <b><i>Conclusion:</i></b> Results indicate that, in our population, the presence of the C allele of -7C/A in TLR3 increases the susceptibility to ESRD. In vitro studies demonstrated that -7C/A may be involved in ESRD development through transcriptional modulation of TLR3.