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Updated: May 13, 2025
Induction of Ocular Surface Inflammation and Collection of Involved Tissues
Published on: August 4, 2022
KGF-2 Alleviates Dry Eye Disease by Regulating the HMGB1/TLR4 Pathway
Yuzhou Wang1,2, Zhiqiang Xu1,2, Linzhi Wei1,2,3
1National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China.
Purpose:
This study aimed to investigate the protective effects of keratinocyte growth factor-2 (KGF-2) in dry eye disease (DED) and elucidate its mechanism of action through the regulation of the HMGB1/TLR4 pathway.
Methods:
Two in vitro models were established by stimulating hyperosmolar human corneal epithelial cells (HCECs) and RAW 264.7 cells with lipopolysaccharide. A DED mice model was established using scopolamine and an intelligently controlled environmental system. After KGF-2 treatment, the symptoms of the DED mice were assessed. The changes in inflammatory factors were measured using Western blotting and quantitative reverse-transcription polymerase chain reaction (RT-qPCR). RNA sequencing (RNA-seq) was used to identify the key factors involved in KGF-2 treatment, followed by validation through in vivo and in vitro knockdown of the relevant factors.
Results:
KGF-2 treatment significantly relieved DED in the mice model through increased tear secretion, and improved fluorescein staining scores. In addition, the levels of inflammatory factors were effectively lowered in both in vitro and in vivo models. Bulk RNA-seq analysis suggested that KGF-2 exerts its effects by regulating the HMGB1/TLR4 pathway. Furthermore, KGF-2 treatment inhibited the upregulation and nuclear translocation of HMGB1 in the DED model, thereby suppressing the levels of inflammatory factors associated with the HMGB1/TLR4 pathway. Knockdown of HMGB1 in HCECs and glycyrrhizin treatment in DED mice exhibited therapeutic effects similar to those of KGF-2.
Conclusions:
KGF-2 demonstrated protective effects in both in vivo and in vitro DED models by modulating the HMGB1/TLR4 pathway. These findings suggest its potential as a therapeutic agent for DED, warranting further clinical investigation in this regard.
Insights
Keratinocyte growth factor-2 (KGF-2) effectively treats dry eye disease (DED) by reducing inflammation via the HMGB1/TLR4 pathway. This study highlights KGF-2 as a promising therapeutic for DED patients.
Area of Science:
- Ophthalmology
- Immunology
- Molecular Biology
Background:
- Dry eye disease (DED) is a prevalent condition characterized by ocular surface inflammation.
- The HMGB1/TLR4 signaling pathway plays a crucial role in mediating inflammation in DED.
Purpose of the Study:
- To investigate the protective effects of keratinocyte growth factor-2 (KGF-2) in DED.
- To elucidate the mechanism of KGF-2 action, focusing on the HMGB1/TLR4 pathway.
Main Methods:
- Established in vitro models using hyperosmolar human corneal epithelial cells (HCECs) and RAW 264.7 cells.
- Developed a DED mice model and assessed KGF-2 treatment effects on symptoms, tear secretion, and inflammatory markers.
- Utilized Western blotting, RT-qPCR, and RNA sequencing (RNA-seq) for molecular analysis, including gene knockdown validation.
Main Results:
- KGF-2 treatment significantly alleviated DED symptoms in mice, increasing tear secretion and improving corneal staining.
- Reduced levels of inflammatory factors were observed in both in vitro and in vivo DED models.
- RNA-seq identified the HMGB1/TLR4 pathway as key; KGF-2 inhibited HMGB1 upregulation and nuclear translocation, suppressing downstream inflammation. HMGB1 knockdown mimicked KGF-2's therapeutic effects.
Conclusions:
- KGF-2 demonstrates significant protective effects in DED models by modulating the HMGB1/TLR4 pathway.
- These findings support KGF-2's potential as a novel therapeutic agent for DED.
- Further clinical investigation is warranted to confirm KGF-2's efficacy in human patients.
