Effects of a Single Nucleotide Polymorphism on the Expression of Human Tumor Necrosis Factor‐alpha

Abstract

Tumor necrosis factor (TNF)-alpha plays a prominent role in inflammations and is a proinflammatory cytokine that has been implicated in the pathogenesis of autoimmune and infectious diseases. Recent association studies have found that the TNF-alpha-857T allele was associated with several disorders. Here we demonstrate, with reporter genes under the control of the two allelic TNF-alpha promoters, that the minor allele -857T is a much stronger transcriptional activator than the major allele -857C in RAW264.7 cell line in response to lipopolysaccharide stimulation. However, the result was not consistent in HeLa cell line. Furthermore, for the quantitative analysis of TNF-alpha synthesis between the -857C/C genotype from healthy subjects and the -857C/T genotype from AS patients, the quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay were performed separately. There was no significant difference between the two groups at the level of mRNA and protein. These results show that this polymorphism may have a direct effect on TNF-alpha regulation in a tissue-specific manner, and apart from the polymorphism at -857 in the TNF-alpha promoter, there may be other factors affecting the expression of TNF-alpha.

TNF polymorphisms in psoriasis: Association of psoriatic arthritis with the promoter polymorphism TNF*‐857 independent of the PSORS1 risk allele

“…A more recent investigation of lipopolysaccharide-stimulated RAW 264.7 cells revealed that upon transfection of reporter genes under the control of the 2 TNF-857 alleles, TNF*-857T is a considerably stronger activator of transcription than is TNF*-857C. However, this result was not consistent with that found in a HeLa cell line, suggesting that depending upon additional factors, alleles of this polymorphism act in a cell-and tissue-specific manner (29).…”

Polymorphisms of tumor necrosis factor-α promoter region for susceptibility to HLA-B27-positive ankylosing spondylitis in Korean population

“…Although its functional role in AS has not yet been well established, variation in the TNFa gene may result in differences in the amount of TNF-a mRNA and protein produced, which may play some role in Table 2 Comparison for frequencies of genotypes between HLA-B27 ? AS patients classified by clinical subtypes and controls, n the pathogenesis of AS [11,12]. Several studies have attempted to investigate the relationship between susceptibility to AS and TNF-a polymorphisms in patients with AS [13][14][15][16][17][18][19].…”

“…healthy controls [10]. Variations in TNF-a production in individuals or in a tissue-specific manner could be explained by gene mutations or polymorphisms within the regulatory regions of TNF-a [11,12]. The TNF1/1 genotype at position -308 in HLA-B27 ?…”

Studies on the role of the skin microbiome in healthy skin and under pathogenic conditions

“…To functionally test this hypothesis we generated allele specific reporter constructs, in which the firefly luciferase gene was placed under the regulation of the proximal TNFA promoter region. Two construct were generated; one included the common (C) allele, whereas the other harbored the rare (T) allele at the site corresponding to the -857th nucleotide position (Lv K 2006). Furthermore, the proximal part of the 3' untranslated region (3' UTR) of the TNFA gene was also cloned into both constructs, similarly as it was described by Denys et al (Denys A 2002).…”

“…A piece of the proximal TNFA promoter was cloned into the pGL4.20 luciferase reporter plasmid (Promega, Madison, USA) similarly as it was described by Lv et al (Lv K 2006). For that a 1012 base pair (bp) piece of the TNFA regulatory region was amplified using the following primers:…”