Abstract
PURPOSE: The purpose of this study was to explore the expression of apoptotic factors in stage III pressure ulcers and explain their effects on wound healing.
SUBJECTS AND SETTING: The sample comprised 8 patients with stage III pressure ulcers, along with 4 volunteers with normal skin who were undergoing elective surgical procedures.
METHODS: Eight patient tissue specimens from wound of stage III pressure ulcers were obtained from hospitalized patients. Tissue specimens from 4 volunteer patients were obtained during surgery. All 12 tissue specimens were analyzed for presence of apoptosis-related factors including bax/bcl-2 (B-cell lymphoma 2), Fas/fasL (Fas ligand), and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) as well as immunohistochemical analysis with Fas/FasL.
RESULTS: Bax positive cells were strongly expressed from surrounding zone to center zone in the specimens obtained from stage III pressure ulcers, and Bcl-2 expression staining decreased contrarily (P < .01). Comparison, apoptotic factors bax positive cell and fas/fasL mRNA expression occurred rarely in tissue specimens from the control group. Fas/fasL mRNA-positive granules were detected in epidermal cells and fibroblasts, demonstrating a progressive increase from the margin of the pressure ulcers progressing toward the center of the wound bed. We also found an increased intensity of TUNEL staining in ulcer center as well as wound margin, compared with control skin tissue.
CONCLUSION: These results suggest that molecular regulators of apoptosis are involved in pressure ulcer wound healing. Results also suggest that differences in the expression and distribution of the apoptotic related factors in stage III pressure ulcers play an important role in the delayed wound healing characteristic of these complex wounds.