3.75 THz Repetitive Radiation Regulates Collagen Metabolism in Human Fetal Scleral Fibroblasts

The sclera constitutes a critical structural element of the eyeball, as its biomechanical properties and structural integrity are primarily governed by collagen metabolism. Using a controlled in vitro experimental system, the present study explored the quantitative relationship between exposure duration to terahertz radiation of distinct frequencies (3.10 THz and 3.75 THz) and the transcriptional expression of collagen metabolism-associated genes in human fetal scleral fibroblasts (HFSFs). During the 120 min terahertz irradiation exposure, neither of the two frequencies produced significant regulatory effects on collagen metabolism-associated genes in normal and hypoxia-induced HFSFs. However, 3.75 THz radiation had markedly raised the expression level of the COL1A1 gene in HFSFs 12 h after the terahertz radiation stopped. Proteomic analysis was conducted on scleral fibroblasts exposed to repeated radiation at 3.75 THz. Proteomic analysis identified a total of 213 differentially expressed proteins (DEPs), comprising 172 downregulated proteins and 41 upregulated proteins. These DEPs were predominantly enriched in ribosome-associated proteins and mitochondrial function-related proteins, suggesting a potential regulatory role in intracellular protein synthesis and ATP production. Furthermore, the study demonstrated that expression levels of fourteen proteins associated with the collagen-rich extracellular matrix exhibited a marked enrichment trend, indicating that repeated exposure to 3.75 THz radiation induces remodeling changes in the scleral extracellular matrix (ECM). This study demonstrates the impacts of terahertz radiation on collagen metabolism of HFSFs and provides preliminary molecular evidence, yet direct functional effects remain unconfirmed. These findings provide theoretical and experimental bases for studying the regulation of scleral collagen metabolism by terahertz radiation.