Abstract

This study investigated the biomechanical properties of human trabecular meshwork (TM) tissue under conditions mimicking physiological and pathological states, examining the interplay between mechanical stress, glucocorticoid treatment, and extracellular matrix remodeling in glaucoma pathophysiology. Fresh human TM tissue samples (n = 112) from 28 donor eyes were subjected to various experimental conditions: physiological pressure (15 mmHg), elevated pressure (30 mmHg), dexamethasone treatment (100 nM), and combined pressure-dexamethasone exposure. Tissue biomechanical properties were assessed using atomic force microscopy, optical coherence elastography, and rheological measurements. Molecular analyses included gene expression profiling, protein quantification, and inflammatory marker assessment. Regional variations, age-related differences, and temporal responses were evaluated. Combined pressure-dexamethasone treatment demonstrated synergistic effects, increasing Young’s modulus by 133.8% (from 4.82 ± 0.56 to 11.27 ± 1.24 kPa, p < 0.001) and storage modulus by 106.6% (from 285.3 ± 32.4 to 589.4 ± 52.7 Pa, p < 0.001). These mechanical changes strongly correlated with ECM remodeling, evidenced by increased COL1A1 expression (r = 0.842, p < 0.001) and decreased MMP2 activity (r = −0.756, p < 0.001). Age-stratified analysis revealed enhanced treatment sensitivity in older subjects (≥ 65 years), with a 138.5% versus 122.6% increase in tissue stiffness compared to younger subjects. Time-course studies demonstrated that molecular changes preceded mechanical alterations, with significant gene expression changes observed within 24 hours. This comprehensive analysis reveals significant interactions between mechanical stress and glucocorticoid exposure in TM tissue, with age-dependent effects on tissue biomechanics and ECM remodeling. The temporal sequence of molecular and mechanical changes suggests potential therapeutic windows for intervention in glaucoma progression. These findings provide new insights into the mechanobiology of TM tissue and identify potential therapeutic targets for glaucoma treatment.