Kaempferol Alleviates Dry Eye Disease Via Modulation of the IDH3B/CCAR2/IKBKB Axis.

Purpose: Dry eye disease (DED), a multifactorial ocular surface disorder characterized by tear film instability and hyperosmolarity, significantly compromises patients' quality of life. This study evaluates the therapeutic efficacy of kaempferol (KAE), a bioactive flavonoid with demonstrated antioxidant and anti-inflammatory properties and explore the underlying molecular mechanisms.

Methods: Tear samples were collected from dry eye patients and normal controls for proteomic analysis. Molecular docking was conducted to detect the binding energy of KAE with target proteins. Then, benzalkonium chloride-induced DED mice models were used to evaluate the therapeutic efficacy of KAE in restoring tear film homeostasis and reducing ocular surface damage through hematoxylin & eosin and periodic acid-Schiff staining. Additionally, TUNEL staining was used to assess cornea apoptosis. Cell Counting Kit-8 was used to calculate cell viability of human corneal epithelial-transformed (HCE-T) cells. Comprehensive analyses, including enzyme-linked immunosorbent assays, immunofluorescence, Western blotting, real-time PCR were used to assess cytokine levels, protein and mRNA expression, respectively.

Results: By integrating critical biological function analyses with key clinical phenotypes, we identified seven core genes, where IDH3B, CCAR2, and IKBKB exhibited the highest binding affinities with KAE. Moreover, KAE effectively improved tear secretion, tear film stability, and conjunctival goblet cell density while attenuating ocular inflammation and apoptosis in DED mice. Concurrently, treatment with KAE resulted in the upregulation of IDH3B and CCAR2, along with a corresponding downregulation of IKBKB in corneal tissues of DED mice and HCE-T cells.

Conclusions: This study provides new insights into the therapeutic potential of KAE as a promising candidate for DED treatment, particularly regulating cell cycle and apoptosis via the IDH3B/CCAR2/IKBKB axis.