Abstract
Chronic nonhealing venous leg ulcers (VLUs) pose a burden to the healthcare due to high management costs and recurrence. Notably, 15-30% of VLUs do not respond to standard of care and remain in nonhealing state. This study evaluated the expression of biomarkers from the wound edge of VLUs to help predict healing outcomes. Potential biomarkers selected for testing have previously been identified to play a role in healing inhibition in VLUs. Using tissue samples collected from the wound edge of 12 patients we used immunoperoxidase staining to evaluate the following potential tissue biomarkers: c-Myc, phosphorylated (activated form) glucocorticoid receptor (p-GR), and caveolin-1 (Cav-1). In addition, mRNA levels were evaluated using qPCR to assess inflammatory markers (IL-1a, IL-1b, TNFa and IL-6), and antimicrobial chemokines (CXCL 1, CXCL 2, CXCL 3 and CXCL 12). Quantitative analyses of p-GR and c-Myc immunohistochemistry have shown a trend of upregulation in non-healing VLUs compared to healing VLUs, while no significant changes were found in Cav-1 levels between the two groups. The results of qPCR have shown an up-regulation of the pro-inflammatory markers IL-1a, IL-1b and IL-6 in VLUs when compared to heathy control skin. TNF? showed a trend of upregulation in non-healing VLUs when compared to healing VLUs and control skin. The chemokines CXCL 1, CXCL 3, and CXCL 12 showed an upregulation in both non-healing and healing VLUs when compared to control skin. No statistical differences in expression level of biomarkers tested with qPCR were found between healing and non-healing VLUs due to the small sample size. Potentially, CXCL 2 and CXCL 12 may be excluded for future studies as the expression levels between healing and non-healing VLUs showed no difference. The utilization of Cav-1, pro-inflammatory cytokines and chemokines as predictive biomarkers should be further evaluated. This study identified p-GR and c-Myc as candidate tissue biomarkers for future validation and utilization as predictive biomarkers for non-healing VLUs.