TNIP1 reduction of HSPA6 gene expression occurs in promoter regions lacking binding sites for known TNIP1-repressed transcription factors

Abstract

TNFα-induced protein 3-interacting protein 1 (TNIP1) represses signaling pathways initiated by specific nuclear and transmembrane receptors. This effect results in reduced activity of distinct transcription factors such as retinoic acid receptors (RAR), peroxisome-proliferator-activated receptors (PPAR), and NFκB. TNIP1-null and TNIP1-knockin defective for ubiquitin-binding mice show increased liver apoptosis, and enlarged spleen and lymph nodes, respectively. To complement current knowledge of TNIP1’s broad physiologic functions as interpreted from in vivo studies and specific expression consequences from transcription factor repression, we determined effects of excess TNIP1 on global gene regulation. Following experimentally increased expression of TNIP1 in cultured keratinocytes, our gene expression microarray analysis not only confirmed TNIP1’s association in previously known pathways and functions but also found a novel TNIP1-regulated pathway – the cell stress response. Under standard culture conditions, expression of several heat shock proteins, including HSPA1A, HSPA6, DNAJA1 and DNAJB1, was reduced. In heat-stressed conditions, differential regulation of HSPA1A and HSPA6 was observed, where only HSPA6 expression was reduced after heat-shock. Using HSPA6 as a model to elucidate the mechanism of the TNIP1-mediated HSP repression, we determined TNIP1 likely represses HSPs through factors other than RAR, PPAR or NFκB despite presence of these factors’ binding sites in the HSPA6 promoter. These results indicate that regulation of HSPs may be through a yet unknown TNIP1-associated pathway. Additionally, these results suggest TNIP1’s reduction of HSP expression levels could negatively impact HSP chaperone capacity or their participation in the cell stress response.

A20 and ABIN1 Suppression of a Keratinocyte Inflammatory Program with a Shared Single-Cell Expression Signature in Diverse Human Rashes

“…Given the increasing awareness of the role keratinocytes play in potentiating inflammatory cutaneous disease, we focused on the function of these two genes in keratinocyte inflammatory response. The combination of A20 and ABIN1 comparative analyses, RNA-seq, and cytokine stimulation treatments enabled us to substantially expand upon previous reports that focused on the effects of ABIN1 overexpression in unstimulated HaCaT keratinocytes (Ramirez et al, 2015) or on a small defined inflammatory gene set with A20 overexpression in Poly (I:C)estimulated NHEK cells (Sohn et al, 2016). Global transcriptional analysis of unstimulated ABIN1 overexpressing HaCaT cells had previously identified enrichment in repressed genes for the "immunological disease" biological process, without further exploration of specific inflammatory genes (Ramirez et al, 2015).…”

“…The combination of A20 and ABIN1 comparative analyses, RNA-seq, and cytokine stimulation treatments enabled us to substantially expand upon previous reports that focused on the effects of ABIN1 overexpression in unstimulated HaCaT keratinocytes (Ramirez et al, 2015) or on a small defined inflammatory gene set with A20 overexpression in Poly (I:C)estimulated NHEK cells (Sohn et al, 2016). Global transcriptional analysis of unstimulated ABIN1 overexpressing HaCaT cells had previously identified enrichment in repressed genes for the "immunological disease" biological process, without further exploration of specific inflammatory genes (Ramirez et al, 2015). We found that under baseline unstimulated conditions, A20 and ABIN1 both repress a small set of inflammatory genes (e.g., C1R, IL32, MMP9, and SAA1) (Figure 1).…”

TNIP1 in Autoimmune Diseases: Regulation of Toll-like Receptor Signaling

“…However, such mRNA increases are not universally predictive of disease state protein levels as Chen et al showed decreased TNIP1 protein in psoriatic plaques [ 38 ] consistent with loss of its repressive effect and promotion of inflammatory skin disease. In complementary studies, we showed overexpression [ 39 ] of TNIP1 protein in HaCaT keratinocytes that led to decreased expression of multiple inflammation-associated genes including interleukin (IL)-6 while TNIP1 reduction [ 40 ] promoted expression of numerous cytokine and chemokine genes. Together, these studies demonstrate TNIP1 as an important inflammatory signal response and regulator gene in diverse cell types.…”

Cofunctional Subpathways Were Regulated by Transcription Factor with Common Motif, Common Family, or Common Tissue

“…Some studies have indicated that motif sequence is associated with TF function. TFs with similar motifs often recognize target genes with similar expression patterns [ 10 ], and TFs with different motifs may directly influence different TF function [ 11 ], and TFs influence pathways initiated by specific DNA-binding motifs [ 34 ]. To explore whether the common-motif TFs tended to regulate cofunctional subpathways, we extracted 1061 human DNA motifs from the Transfac database.…”