Transcription factor ICBP90 regulates the MIF promoter and immune susceptibility locus
Jie Yao, … , Patty Lee, Richard Bucala
Jie Yao, … , Patty Lee, Richard Bucala
Published January 11, 2016
Citation Information: J Clin Invest. 2016;126(2):732-744. https://doi.org/10.1172/JCI81937.
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Research Article Immunology

Transcription factor ICBP90 regulates the MIF promoter and immune susceptibility locus

Abstract

The immunoregulatory cytokine macrophage migration inhibitory factor (MIF) is encoded in a functionally polymorphic locus that is linked to the susceptibility of autoimmune and infectious diseases. The MIF promoter contains a 4-nucleotide microsatellite polymorphism (–794 CATT) that repeats 5 to 8 times in the locus, with greater numbers of repeats associated with higher mRNA levels. Because there is no information about the transcriptional regulation of these common alleles, we used oligonucleotide affinity chromatography and liquid chromatography–mass spectrometry to identify nuclear proteins that interact with the –794 CATT5–8 site. An analysis of monocyte nuclear lysates revealed that the transcription factor ICBP90 (also known as UHRF1) is the major protein interacting with the MIF microsatellite. We found that ICBP90 is essential for MIF transcription from monocytes/macrophages, B and T lymphocytes, and synovial fibroblasts, and TLR-induced MIF transcription is regulated in an ICBP90- and –794 CATT5–8 length–dependent manner. Whole-genome transcription analysis of ICBP90 shRNA–treated rheumatoid synoviocytes uncovered a subset of proinflammatory and immune response genes that overlapped with those regulated by MIF shRNA. In addition, the expression levels of ICBP90 and MIF were correlated in joint synovia from patients with rheumatoid arthritis. These findings identify ICBP90 as a key regulator of MIF transcription and provide functional insight into the regulation of the polymorphic MIF locus.

Authors

Jie Yao, Lin Leng, Maor Sauler, Weiling Fu, Junsong Zheng, Yi Zhang, Xin Du, Xiaoqing Yu, Patty Lee, Richard Bucala

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Figure 7

The ICBP90-dependent transcription response shows concordance with MIF-regulated genes in rheumatoid synovium.

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The ICBP90-dependent transcription response shows concordance with MIF-r...
(A) Comparative effect in rheumatoid synovial fibroblasts of ICBP90 shRNA (or control) on ICBP90 and MIF expression (left) versus MIF shRNA (or control) on MIF expression (right). No appreciable effect of MIF shRNA on ICBP90 expression was observed (data not shown). (B) Venn diagrams illustrating the relationship between ICBP90- and MIF-regulated gene transcripts. (C) Expression heatmaps of genes selected for 1.5-fold differential expression with FDR < 0.05. Data are for synovial fibroblast cell lines isolated from 3 individuals with rheumatoid arthritis. (D) Correlation plots for ICBP90 versus MIF mRNA expression in RNA samples obtained from the joint synovia of subjects with rheumatoid arthritis (RA, n = 86) or osteoarthritis (OA, n = 22). The expression scores were calculated from a quartile-trimmed mean of the normalized probe set values. P < 0.0001 for mean MIF expression in RA (12.81 ± 0.29) versus OA (9.37 ± 0.15); P < 0.001 for mean ICBP90 expression in RA (7.98 ± 0.67) versus OA (5.82 ± 0.334) by 2-tailed Student’s t test. (E) High genotypic MIF expressor human rheumatoid synovia express greater amounts of MIF mRNA and MIF protein than low MIF expressor genotypes. MIF mRNA was measured by qPCR analysis and expressed relative to 18S rRNA mRNA, and supernatant MIF content was measured by ELISA in 72-hour cultures of early-passage synoviocytes. Four patient-derived early-passage synovial fibroblast lines were studied for each genotype group (i.e., 4 CATT5-containing genotype lines and 4 CATT6- and CATT7-containing genotypes). Three measurements were obtained for each genotyped cell line. Mean ± SD. *P < 0.05, **P < 0.02 by 2-tailed Student’s t test.