High Fructose Intake Promotes Adipose-Lung Crosstalk via Inflammatory Mediators, Exacerbating Allergic Asthma Responses in OVA- Sensitized C57BL/6 Mice

다국어 초록 (Multilingual Abstract)

Dietary fructose is increasingly recognized as a potent immuno-metabolic stressor. However , its mechanistic contribution to the pathogenesis of airway allergy remains inadequately characterized. This study elucidates how chronic fructose consumption amplifies allergen-driven inflammation in an ovalbumin (OVA)-sensitized C57BL/6 murine model. A high-fructose diet substantially elevated lipid peroxidation in pulmonary and adipose tissues, reflecting a pronounced reactive oxygen species (ROS) generation and systemic oxidative burden. This metabolic dysregulation coincided with marked epithelial architectural remodeling, mucus hypersecretion, and extensive infiltration with mononuclear and polymorphonuclear cells. Fructose-exposed mice demonstrated GLUT5 and GLUT2 transcriptional upregulation, indicating augmented fructose transmembrane transport and intracellular metabolic flux. Immunohistochemical analyses revealed substantial F4/80⁺ and CD11c⁺ macrophage enrichment with pronounced M1-dominant CD80⁺ expression and diminished CD206⁺ M2 macrophage population. These M1 macrophages exhibited heightened phagocytic activity, supported by transcriptomic enrichment of phagosome maturation, lysosomal fusion, and myeloperoxidase (MPO)-dependent oxidative pathways. MPO was markedly elevated, and DIF revealed widespread extracellular chromatin scaffolds. MPO co-localization with citrullinated histone H3 (CitH3) confirmed both neutrophil extracellular traps (NETs) and macrophage extracellular traps (METs), with MET formation disproportionately prominent in fructose groups. Chemokine profiling demonstrated robust CCL2, CCL5, CXCL1, CXCL2, CXCL5, and CXCL9 upregulation across both tissues, substantiating the bidirectional adipose-lung inflammatory crosstalk. Transcriptomic analyses confirmed enrichment of ROS biosynthesis, neutrophil degranulation, phagosomal maturation, and chemokine-driven leukocyte trafficking pathways. Thus, dietary fructose exacerbates allergic airway inflammation by intensifying oxidative stress and promoting M1-dominant macrophage activation with amplified phagocytic activity, prominent NETosis and METosis, and fortified adipose-lung chemokine communication. Therefore, fructose serves as a critical dietary determinant with significant implications for asthma pathogenesis and therapeutic intervention.

목차 (Table of Contents)

• TABLE OF CONTENT I
• LIST OF FIGURES IV
• LIST OF TABLES VI
• LIST OF ABBRIVIATIONS VII
• ABSTRACT 1
• INTRODUCTION 2
• OBJECTIVES OF THE STUDY 9
• HYPOTHESIS 10
• MATERIALS AND METHODS 11
• Animal Model 11
• Measurement of the malondialdehyde (MDA) levels 12
• Histopathological analysis 13
• Measurement of Mean linear intercept (MLI) 13
• Transcriptomic Analysis 13
• Immunohistochemical analysis 14
• Double immunofluorescence staining 15
• Enzyme Linked Immunosorbent Assay (ELISA) 15
• RNA extraction, cDNA synthesis, and real-time PCR analysis 15
• Statistical Analysis 18
• RESULTS 19
• Dietary fructose potentiates induces the ROS production and infiltration of inflammatory cells, macrophage in crown like structure (CLS) and structural alterations in lung and adipose tissue. 19
• Synergistic effects of fructose and allergen challenge on goblet cell hyperplasia, epithelial remodeling, and mast cell degranulation 22
• Differential Gene Expression Reveals Strong ROS-Linked Myeloid Activation and Chemokine-Driven Inflammatory Networks Under Fructose and Allergen Co-Exposure. 25
• Transcriptomic Profiling Reveals ROS-Linked Innate Activation and Phagocytic Signaling in OVA+HFr Mice. 28
• Coordinated Upregulation of Adipokines and Chemokines Under High-Fructose Conditions Establishes a Pro-Inflammatory Lung-ADT Network 37
• Dietary Fructose Potentiates MPO Expression In Lung Alveolar And Adipose Tissues During OVA-Induced Inflammation. 40
• MPO And F4/80 Double Immunofluorescence Analysis Of Macrophage Infiltration In Lung And Adipose Tissue Compartment. 42
• Fructose Enhances MPO-Driven Oxidative Activation And CD11c⁺ Macrophage Interaction Across Lung And Adipose Tissue. 44
• Enhanced MPO-CitH3 Co-localization Reveals Fructose Induced METosis And Cross-organ Inflammatory Amplification. 47
• High Fructose Diet Modulate The Resident And Recruiting Macrophage Profile Across The Lung And Adipose Tissue of OVA Induced Asthmatic Mice 50
• Fructose Potentiates Pro-inflammatory Macrophage Polarization (CD80+F4/80+) In Lung And Adipose Tissue. 53
• Fructose Driven Modulation of CD206+F4/80+ Macrophages Underscores Lung-ADT Inflammatory Crosstalk. 56
• Fructose Enhances Allergen Driven CD11c+/CD80+ Macrophage Recruitment And Polarization In Lung And ADT. 59
• Fructose Induced Alteration of CD11c/CD206⁺ Macrophages Emphasizes Lung-ADT Immune Crosstalk. 62
• High Fructose Intake Intensifies Allergen-Induced Macrophage Activation, T-Helper Differentiation, and Cytokine Responses in Lung and Adipose Tissue. 65
• DISCUSSION 69
• CONCLUSION 76
• REFERENCE 78