Increased expression of ORMDL3 in allergic asthma: a case control and in vitro study

Area of Science:

• Genetics and immunology
• Pediatric respiratory diseases

Background:

• Childhood asthma is a prevalent chronic condition.
• The ORMDL3 gene is a consistently replicated genetic finding in childhood asthma across multiple Genome-Wide Association Studies (GWAS).

Purpose of the Study:

• To investigate the role of ORMDL3 gene variants and expression in childhood asthma within the Polish population.
• To analyze specific ORMDL3 single nucleotide polymorphisms (SNPs) and promoter methylation levels in relation to childhood asthma.

Main Methods:

• Genotyping of two ORMDL3 SNPs (rs3744246 and rs8076131) using TaqMan probes in 416 subjects (223 asthmatic children, 193 controls).
• Assessment of ORMDL3 promoter methylation using Methylation Sensitive High-Resolution Melting (MS-HRM).
• Analysis of ORMDL3 expression in peripheral blood mononuclear cells (PBMCs) from asthmatic children and in cytokine-stimulated human bronchial epithelial cells.

Main Results:

• ORMDL3 expression was significantly increased in PBMCs from children with allergic asthma compared to controls.
• In vitro studies showed increased ORMDL3 expression in human bronchial epithelial cells upon stimulation with Th2 cytokines (IL-13, IL-4).
• No significant differences were found in the genotype distribution of the analyzed ORMDL3 SNPs or in promoter methylation levels between asthmatic children and controls.

Conclusions:

• Elevated ORMDL3 expression is associated with pediatric allergic asthma.
• ORMDL3 expression is upregulated in airways following Th2 cytokine stimulation, suggesting a role in allergic airway inflammation.
• Further functional studies are necessary to elucidate the precise mechanisms by which ORMDL3 contributes to childhood asthma.