Signal transducer and activator of transcription 6 directly regulates human ORMDL3 expression

Abstract

Orosomucoid-like 3 (ORMDL3) has been associated with asthma and a series of autoimmune disorders, and is involved in endoplasmic reticulummediated inflammatory responses. However, its clinical significance and the molecular mechanism underlying its expression are still largely unclear. To elucidate the mechanisms of human ORMDL3 transcriptional regulation, we cloned a 1.5 kb genomic DNA fragment containing the putative promoter region and evaluated its transcriptional activity in a luciferase reporter system by deletion analysis. We identified a 68 bp region that functions as a minimal promoter. Bioinformatics analysis predicted that the À64 to À56 bp region contained a signal transducer and activator of transcription 6 (STAT6) binding site. Electrophoretic mobility shift assay and chromatin immunoprecipitation demonstrated that STAT6 bound to its binding site within the ORMDL3 promoter. STAT6 over-expression or knockdown trans-activated or trans-inhibited, respectively, the ORMDL3 promoter containing the STAT6-binding motif. Treatment with interleukins 4 or 13 increased ORMDL3 promoter activity as well as endogenous ORMDL3 expression. Immunoprecipitation and ChIP/Re-ChIP assays revealed that STAT6 and p300 exist in the same protein complex that binds to the ORMDL3 promoter. Our study confirmed that STAT6 plays important roles in regulating the expression of human ORMDL3 by directly binding to the promoter region, which may shed light on a possible role in various human diseases.Structured digital abstract p300 physically interacts with STAT6 by anti bait coimmunoprecipitation (View Interaction: 1, 2)

The role of ORMDL proteins, guardians of cellular sphingolipids, in asthma

“…Firstly, in vitro study of the ORMDL3 promoter revealed that Est-1, p300, and CREB are regulators of ORMDL3 expression and that the levels of these regulators correlated with expression of ORMDL3 in recurrent wheeze patients (43). Later, STAT6 was shown to be a direct regulator of ORMDL3 expression (44), confirming previous findings that both ORMDL3 and STAT6 are associated with asthma (45). Furthermore, the role of chromatin in ORMDL3 expression was evaluated.…”

“…A recent study with IL-13 knockout mice described the dependence of ORMDL3 overexpression on IL-13 (67). It has also been shown that IL-4 and IL-13 induction of ORMDL3 expression is STAT6 dependent (44). Very similar regulation of ORMDL3 expression was observed in studies of fatty acid-binding protein 4 (FABP4), which is known to regulate allergic airway inflammation and provides a link between the fatty acid metabolism and asthma phenotype (99).…”

“…To this end, it has been shown that pharmacological inhibition of c-secretase cleavage of Notch resulted in decreased Th2 cytokine response and suppressed lung inflammation (87,92,93). Stronger activity of c-secretase may result in the increased production of Th2 cytokines, which were shown to stimulate ORMDL3 expression in mice (44,67,91). Based on these observations, we propose a mechanism according to which enhanced expression of ORMDL3 in allergen-exposed patients with asthma results in an increased maturation and/or activity and stability of csecretase complex.…”

“…Based on these observations, we propose a mechanism according to which enhanced expression of ORMDL3 in allergen-exposed patients with asthma results in an increased maturation and/or activity and stability of csecretase complex. This may then lead to stronger production of Th2 cytokines that further support ORMDL3 expression and promote inflammation in the lung (44,67,91). Further investigation of the ORMDL-c-secretase cross-talk is needed to determine whether the ORMDL-c-secretase pathway could be a suitable target for the treatment of asthma disease.…”

Telomerase activates transcription of cyclin D1 gene through an interaction with NOL1

“…To further validate the co-occupancy of NOL1 and hTERT in the cyclin D1 promoter, we performed a ChIP-re-ChIP assay (Qiu et al, 2013). HeLa S3 cells expressing Flag-hTERT and NOL1-V5 were subjected to ChIP with anti-Flag antibody, followed by re-ChIP using anti-V5 antibody.…”