Abstract
Orosomucoid 1-like 3 (ORMDL3) gene was strongly linked with the development of asthma in genetic association studies, and its expression could be significantly induced by allergen in airway epithelial cells of mice. However, the expression mechanism of ORMDL3 was still unclear. Here we have identified and characterized the mouse ORMDL3 gene promoter. Deletion constructs of the 5′ flanking region were fused to a luciferase reporter gene. After transient transfection in mouse fibroblast cell line NIH3T3, a CRE (−27/−20) binding CREB was identified in the core promoter region. Deletion or mutation of the CRE consensus sequence resulted in a significant loss of the promoter activity. EMSA and ChIP assays demonstrated the binding of CREB to the core promoter. Knocking down endogenous CREB led to a reduction in ORMDL3 expression. Conversely, overexpression of CREB up-regulated ORMDL3 expression. Moreover, forskolin, a PKA activator, could facilitate the phosphorylation of CREB, which in turn heightens ORMDL3 expression. H-89, a PKA-specific inhibitor, could significantly inhibit ORMDL3 expression. This study delineates the characterization of mouse ORMDL3 gene promoter and shows signaling pathway cAMP/PKA/CREB plays an important role in regulating ORMDL3 expression, which will be helpful for future animal model studies regarding the regulation or function of ORMDL3 gene.
Highlights
The orosomucoid 1-like 3 (ORMDL3) gene, which belongs to a novel evolutionarily conserved gene family (ORMDL1-3), encodes a protein locate in the endoplasmic reticulum (ER) membrane [1]
The relationship between Orosomucoid 1-like 3 (ORMDL3) and asthma is best established: 1) the relationship between asthma risk alleles on 17q21 locus and ORMDL3 mRNA level is strong, and already exist in cord blood [8]; 2) changed transcript level of ORMDL3 is found in EpsteinBarr virus transformed lymphoblastoid cell lines from children with asthma [2]; 3) ORMDL3 expression can be significantly induced by allergen in airway epithelial cells of mice [9]; 4) the induction of ORMDL3 high expression in normal human lung fibroblasts by polyinosine-polycytidylic acid indicates the role ORMDL3 may play in viral respiratory infection [10,11], a pathological state believed to induce and exacerbate asthma [12]; 5) transcript level of ORMDL3 in children with recurrent wheeze is higher than in normal children [13]
To identify the functional proximal promoter of mouse ORMDL3 (mORMDL3) gene and locate the key genomic regions involved in mORMDL3 gene expression, basing on the National Center for Biotechnology Information (NCBI) sequence database, we defined the reported mORMDL3 (NM_025661.4) 59 end position as the transcriptional start site (TSS) reference, designated as position +1
Summary
The orosomucoid 1-like 3 (ORMDL3) gene, which belongs to a novel evolutionarily conserved gene family (ORMDL1-3), encodes a protein locate in the endoplasmic reticulum (ER) membrane [1]. It has been well established by a series of independent genome-wide association studies (GWAS) that ORMDL3 is a risk factor for the development of many immune-related diseases, e.g. asthma, recurrent wheeze, ulcerative colitis, ankylosing spondylitis, type 1 diabetes and rheumatoid arthritis [2,3,4,5,6,7]. Elucidating the molecular mechanism that control transcription of ORMDL3 gene may yield insights into the mechanism how misregulation of ORMDL3 leads to the pathology of asthma
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
