The ERBB2 Exonic Variant Pro1170Ala Modulates Mitogen-Activated Protein Kinase Signaling Cascades and Associates with Allergic Asthma

• Main Authors: Sio, Yang Yie, Gan, Wei Liang, Ng, Wing Shan, Matta, Sri Anusha, Say, Yee How*, Teh, Keng Foo *, Wong, Yi Ru *, Smyrna Moti, Rawanan Shah *, Kavita, Reginald *, Chew, Fook Tim
• Format: Article
• Published: Karger Publishers 2023
• Subjects: QP Physiology; QR Microbiology; RC Internal medicine
• Online Access: http://eprints.sunway.edu.my/2669/; https://doi.org/10.1159/000530960
• Institution: Sunway University

Introduction: Previous studies have indicated the ERBB2 genetic variants in the 17q12 locus might be associated with asthma; however, the functional effects of these variants on asthma risk remain inconclusive. This study aimed to characterize the functional roles of asthma-associated ERBB2 single nucleotide polymorphisms (SNPs) in asthma pathogenesis by performing genetic association and functional analysis studies. Methods: This study belongs to a part of an ongoing Singapore/Malaysia cross-sectional genetics and epidemiological study (SMCSGES). Genotype-phenotype associations were assessed by performing a genotyping assay on n = 4,348 ethnic Chinese individuals from the SMCSGES cohort. The phosphorylation levels of receptors and signaling proteins in the MAPK signaling cascades, including ErbB2, EGFR, and ERK1/2, were compared across the genotypes of asthma-associated SNPs through in vitro and ex vivo approaches. Results: The ERBB2 tag-SNP rs1058808 was significantly associated with allergic asthma, with the allele "G" identified as protective against the disease (adjusted logistic p = 6.56 × 10-9, OR = 0.625, 95% CI: 0.544-0.718). The allele "G" of rs1058808 resulted in a Pro1170Ala mutation that results in lower phosphorylation levels of ErbB2 in HaCat cells (p < 0.001), whereas the overall ERBB2 mRNA expression and the phosphorylation levels of EGFR remained unaffected. In the SMCSGES cohort, individuals carrying the genotype "GG" of rs1058808 had lower phosphorylated ERK1/2 proteins in the MAPK signaling cascade. A lower phosphorylation level of ERK1/2 was also associated with reduced asthma risk. Conclusions: The present findings highlighted the involvement of a functional exonic variant of ERBB2 in asthma development via modulating the MAPK signaling cascade.