Acetylome Analyses Provide New Insights Into the Effects of Childhood Allergic Rhinitis on Olfactory Bulb‐Dependent Olfactory Impairment

Allergic rhinitis (AR) is a growing public health, medical and economic problem worldwide; the incidence of AR in the pediatric population is approximately 20% [1]. In addition to typical nasal symptoms, AR can lead to olfactory dysfunction, anxiety, depression, cognitive impairment, etc. [2, 3]. Olfactory bulb (OB)-dependent olfactory impairment refers to a deficit in smell perception that originates primarily from functional or structural abnormalities within the OB. However, relatively few researchers have investigated OB-dependent olfactory impairment in pediatric AR, and the underlying mechanism has not yet been fully clarified. A total of 162 children in the AR (n = 82) and Healthy (n = 80) groups were included (Figure 1A and Table S1). Our analysis assessed odor identification using the Universal Sniff (U-Sniff) test [4], which employs graphics and descriptors in a four-alternative forced-choice paradigm with a 12-point scale, and revealed significantly impaired olfactory function in children with AR (mean difference = −0.97, 95% CI: −1.44 to −0.49, p < 0.0001, power = 0.98), alongside an increased incidence of olfactory dysfunction (χ2 = 14.73, p < 0.0001) (Figure 1B,C). In addition, AR children have more obvious anxiety (mean difference = 3.52, 95% CI: 0.97–1.29, p = 0.007) and depression (mean difference = 1.79, 95% CI: 0.45–3.13, p = 0.009). Specifically, they demonstrated significantly elevated scores across various dimensions of anxiety, including generalized anxiety, separation anxiety, and social phobia (Figure 1D). After adjusting covariates, the difference in U-Sniff scores maintained statistical significance (F = 13.06, p < 0.0001). To further simulate pediatric patients, we utilized 3-week-old mice corresponding to the sensitization timeline (Figure 1E–G). OVA-sensitized AR mice exhibited profound olfactory deficits (Figure 1H–L). To assess the impact of AR on the OB at the molecular level, mass spectrometry analysis identified 5667 quantified proteins, including 25 upregulated and 84 downregulated proteins in AR (Figure 1M–O and Figure S1A). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis highlighted metabolic and inflammatory perturbations associated with AR pathology (Figure 1P and Figure S1B). Next, we revealed a significant increase in acetylation levels (Figure S1C). We identified 1707 acetylation sites distributed across 6809 acetylated proteins, accounting for 25.07% (Figure 2F). Our results detected 42 downregulated Kac sites on 41 proteins and 436 upregulated Kac sites on 319 proteins (Figure 2G). Motif analysis identified acetylated lysine motifs, revealed structural preferences, and detected cluster-specific residue biases (Figure S2). A total of seventy acetylated lysine sites on core histones were identified and quantified. Among these, H3K9ac and H3K14ac exhibited significantly enhanced acetylation in AR (Figure 2H,I). GO enrichment revealed functions primarily in neuronal energy metabolism/signaling (Figure S1D). KEGG enriched pathways included olfactory transduction and the synaptic vesicle cycle. Additionally, the cAMP, cGMP-PKG, and calcium signaling pathways were prominently represented. Metabolic pathways were also strongly implicated, with enrichment observed in the TCA cycle, glycolysis/gluconeogenesis, and propanoate metabolism. The locations of the involved acetylated protein sites are illustrated in Figure 2J. Based on Protein–Protein Interaction (PPI) network analysis, both olfactory signaling cluster and metabolic cluster demonstrated tight connectivity with one another (Figure 2K). Quantitative assessment revealed a marked downregulation of ACSS2 and SIRT1. Conversely, the expression levels of P300 and HDAC2 were increased in the AR (Figure 2A–E and Figure S4). Furthermore, key enzyme P300 [5] inhibition rescued olfactory function and increased mitral cell count, nissl body density, and DCX/NeuN positive neuron (Figure S3). This study has limitations, the modest sample size of the pediatric cohort and the constrained direct applicability of murine model findings to human due to inherent interspecies differences. In conclusion, our findings revealed that AR contributes to olfactory dysfunction in children. Mechanistically, AR-induced olfactory impairment is linked to alterations in acetylated proteins, providing novel insights into how nasal inflammatory processes related to AR disrupt the function of the OB in children. Ruikun Wang, Ziying Xu, and Yimin Zhang contributed equally to this work. Ruikun Wang and Ziying Xu conceived the study and designed the experiments. Yimin Zhang, Mengyao Li, and Jieqiong Liang performed the majority of the experiments and data collection. Qian Wang and Xiaojun Zhan conducted data analysis and interpretation. YinXia Lu and Jing Yuan provided critical reagents, technical support, and experimental guidance. Shan Wang and Qinglong Gu supervised the project, secured funding, and oversaw the research direction. Ruikun Wang, Ziying Xu, and Yimin Zhang drafted the manuscript. Jing Yuan, Shan Wang, and Qinglong Gu critically reviewed and revised the manuscript. All authors read and approved the final version of the manuscript. This work was supported by grants from the Key Program of Capital's Funds for Health Improvement and Research (2022-1-2101), the Beijing Municipal Natural Science Foundation (7232010), New Quality Fund of Capital Institute of Pediatrics (XZYY-2025-05), the National Natural Science Foundation of China for Key Programs of China Grants (82130065), Beijing High-Level Public Health Technical Talent Project (2023–02–08), Beijing Hospitals Authority's Ascent Plan (DFL20241301), and Basic research project of Capital Institute of Pediatrics (JCYJ-2025-11). The key Program of Capital's Funds for Health Improvement and Reasearch (2022-1-2101); the Beijing Munucipal Natural Science Foundation (7232010); New Quality Fund of Capital Institute of Pediatrics (XZYY-2025-05); the National Natural Science Foundation of China for Kry Programs of China Grants (82130065); Beijing High-Level Public Health Technical Talent Project (2023-02-08); Beijing Hospitals Authority's Ascent Plan (DFL20241301); Basic research project of Capital Insitute of Pediatrics (JCYJ-2025-11). The authors declare no conflicts of interest. The data that support the findings of this study are available on request from the corresponding author. Data are available via ProteomeXchange with identifier PXD066708. Data S1: all70254-sup-0001-Supinfo.zip. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. 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